﻿// basisu_transcoder.cpp
// Copyright (C) 2019-2026 Binomial LLC. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "basisu_transcoder.h"
#include "basisu_containers_impl.h"

#include "basisu_astc_hdr_core.h"

#define BASISU_ASTC_HELPERS_IMPLEMENTATION
#include "basisu_astc_helpers.h"
#include "basisu_xbc7_decoder.h"

#include <limits.h>

#if defined(_MSC_VER)
	#include <intrin.h> // For __popcnt intrinsic
#endif

#ifndef BASISD_IS_BIG_ENDIAN
// TODO: This doesn't work on OSX. How can this be so difficult?
//#if defined(__BIG_ENDIAN__) || defined(_BIG_ENDIAN) || defined(BIG_ENDIAN)
//	#define BASISD_IS_BIG_ENDIAN (1)
//#else
	#define BASISD_IS_BIG_ENDIAN (0)
//#endif
#endif

#ifndef BASISD_USE_UNALIGNED_WORD_READS
	#ifdef __EMSCRIPTEN__
		// Can't use unaligned loads/stores with WebAssembly.
		#define BASISD_USE_UNALIGNED_WORD_READS (0)
	#elif defined(_M_AMD64) || defined(_M_IX86) || defined(__i386__) || defined(__x86_64__)
		#define BASISD_USE_UNALIGNED_WORD_READS (1)
	#else
		#define BASISD_USE_UNALIGNED_WORD_READS (0)
	#endif
#endif

// Using unaligned loads and stores causes errors when using UBSan. Jam it off.
#if defined(__has_feature)
#if __has_feature(undefined_behavior_sanitizer)
#undef BASISD_USE_UNALIGNED_WORD_READS
#define BASISD_USE_UNALIGNED_WORD_READS 0
#endif
#endif

// Also see BASIS_FILE_VERSION, which is the version we output. Currently, they cannot diverge - the version must be this.
#define BASISD_SUPPORTED_BASIS_VERSION (0x13)

#ifndef BASISD_SUPPORT_KTX2
	#error Must have defined BASISD_SUPPORT_KTX2
#endif

#ifndef BASISD_SUPPORT_KTX2_ZSTD
	#error Must have defined BASISD_SUPPORT_KTX2_ZSTD
#endif

// Set to 1 for fuzz testing. This will disable all CRC16 checks on headers and compressed data.
#ifndef BASISU_NO_HEADER_OR_DATA_CRC16_CHECKS
	#define BASISU_NO_HEADER_OR_DATA_CRC16_CHECKS 0
#endif

#ifndef BASISD_SUPPORT_DXT1
	#define BASISD_SUPPORT_DXT1 1
#endif

#ifndef BASISD_SUPPORT_DXT5A
	#define BASISD_SUPPORT_DXT5A 1
#endif

// Disable all BC7 transcoders if necessary (useful when cross compiling to Javascript)
#if defined(BASISD_SUPPORT_BC7) && !BASISD_SUPPORT_BC7
	#ifndef BASISD_SUPPORT_BC7_MODE5
		#define BASISD_SUPPORT_BC7_MODE5 0
	#endif
#endif // !BASISD_SUPPORT_BC7

// BC7 mode 5 supports both opaque and opaque+alpha textures, and uses less memory BC1.
#ifndef BASISD_SUPPORT_BC7_MODE5
	#define BASISD_SUPPORT_BC7_MODE5 1
#endif

#ifndef BASISD_SUPPORT_PVRTC1
	#define BASISD_SUPPORT_PVRTC1 1
#endif

#ifndef BASISD_SUPPORT_ETC2_EAC_A8
	#define BASISD_SUPPORT_ETC2_EAC_A8 1
#endif

// Set BASISD_SUPPORT_UASTC to 0 to completely disable support for transcoding UASTC files.
#ifndef BASISD_SUPPORT_UASTC
	#define BASISD_SUPPORT_UASTC 1
#endif

#ifndef BASISD_SUPPORT_ASTC
	#define BASISD_SUPPORT_ASTC 1
#endif

#ifndef BASISD_SUPPORT_XUASTC
#define BASISD_SUPPORT_XUASTC 1
#endif

// Note that if BASISD_SUPPORT_ATC is enabled, BASISD_SUPPORT_DXT5A should also be enabled for alpha support.
#ifndef BASISD_SUPPORT_ATC
	#define BASISD_SUPPORT_ATC 1
#endif

// Support for ETC2 EAC R11 and ETC2 EAC RG11
#ifndef BASISD_SUPPORT_ETC2_EAC_RG11
	#define BASISD_SUPPORT_ETC2_EAC_RG11 1
#endif

// If BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY is 1, opaque blocks will be transcoded to ASTC at slightly higher quality (higher than BC1), but the transcoder tables will be 2x as large.
// This impacts grayscale and grayscale+alpha textures the most.
#ifndef BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
	#ifdef __EMSCRIPTEN__
		// Let's assume size matters more than quality when compiling with emscripten.
		#define BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY 0
	#else
		// Compiling native, so an extra 64K lookup table is probably acceptable.
		#define BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY 1
	#endif
#endif

#ifndef BASISD_SUPPORT_FXT1
	#define BASISD_SUPPORT_FXT1 1
#endif

#ifndef BASISD_SUPPORT_PVRTC2
	#define BASISD_SUPPORT_PVRTC2 1
#endif

#if BASISD_SUPPORT_PVRTC2
	#if !BASISD_SUPPORT_ATC
		#error BASISD_SUPPORT_ATC must be 1 if BASISD_SUPPORT_PVRTC2 is 1
	#endif
#endif

#if BASISD_SUPPORT_ATC
	#if !BASISD_SUPPORT_DXT5A
		#error BASISD_SUPPORT_DXT5A must be 1 if BASISD_SUPPORT_ATC is 1
	#endif
#endif

#ifndef BASISD_SUPPORT_UASTC_HDR
	#define BASISD_SUPPORT_UASTC_HDR 1
#endif

#define BASISD_WRITE_NEW_BC7_MODE5_TABLES			0
#define BASISD_WRITE_NEW_DXT1_TABLES				0
#define BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES			0
#define BASISD_WRITE_NEW_ASTC_TABLES				0
#define BASISD_WRITE_NEW_ATC_TABLES					0
#define BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES		0

#ifndef BASISD_ENABLE_DEBUG_FLAGS
	// DO NOT CHECK IN
	#define BASISD_ENABLE_DEBUG_FLAGS	0
#endif

// Zstd is used both for KTX2 supercompressed UASTC files and for Zstd-compressed data in other codecs (independent of KTX2 support), so include the header whenever Zstd usage is enabled -- not just when KTX2 is enabled.
// If BASISD_SUPPORT_KTX2_ZSTD is 0, data compressed with Zstd cannot be loaded.
#if BASISD_SUPPORT_KTX2_ZSTD
	// We only use these Zstd API's: ZSTD_decompress(), ZSTD_isError() and ZSTD_getFrameContentSize()
	#include "../zstd/zstd.h"
#endif

#if BASISD_SUPPORT_UASTC_HDR
using namespace basist::astc_6x6_hdr;
#endif

#if BASISD_IS_BIG_ENDIAN
const uint32_t BASISD_COLOR_RGBA_A_MASK = 0x000000FF;
const uint32_t BASISD_COLOR_RGBA_RGB_MASK = ~BASISD_COLOR_RGBA_A_MASK;
#else
const uint32_t BASISD_COLOR_RGBA_A_MASK = 0xFF000000;
const uint32_t BASISD_COLOR_RGBA_RGB_MASK = ~BASISD_COLOR_RGBA_A_MASK;
#endif

namespace basisu
{
	bool g_debug_printf;

	void enable_debug_printf(bool enabled)
	{
		g_debug_printf = enabled;
	}

	void debug_printf(const char* pFmt, ...)
	{
#if BASISU_FORCE_DEVEL_MESSAGES	
		g_debug_printf = true;
#endif
		if (g_debug_printf)
		{
			va_list args;
			va_start(args, pFmt);
			vprintf(pFmt, args);
			va_end(args);
		}
	}

	void debug_puts(const char* p)
	{
#if BASISU_FORCE_DEVEL_MESSAGES	
		g_debug_printf = true;
#endif
		if (g_debug_printf)
		{
			//puts(p);
			printf("%s", p);
		}
	}
} // namespace basisu

namespace basist
{
#if BASISD_ENABLE_DEBUG_FLAGS
	static uint32_t g_debug_flags = 0;
#endif

	uint32_t get_debug_flags()
	{
#if BASISD_ENABLE_DEBUG_FLAGS
		return g_debug_flags;
#else
		return 0;
#endif
	}

	void set_debug_flags(uint32_t f)
	{
		BASISU_NOTE_UNUSED(f);
#if BASISD_ENABLE_DEBUG_FLAGS
		g_debug_flags = f;
#endif
	}
	
	// Used by arith encoder/decoder
	namespace arith_fastbits_f32
	{
		bool  g_initialized;
		float g_lut_edge[TABLE_SIZE + 1]; // samples at m = 1 + i/TABLE_SIZE (for linear)

	} // namespace arith_fastbits_f32

	inline uint16_t byteswap_uint16(uint16_t v)
	{
		return static_cast<uint16_t>((v >> 8) | (v << 8));
	}

	static inline int32_t clampi(int32_t value, int32_t low, int32_t high) { if (value < low) value = low; else if (value > high) value = high;	return value; }
	static inline float clampf(float value, float low, float high) { if (value < low) value = low; else if (value > high) value = high;	return value; }
	static inline float saturate(float value) { return clampf(value, 0, 1.0f); }

	static inline uint8_t mul_8(uint32_t v, uint32_t q) { v = v * q + 128; return (uint8_t)((v + (v >> 8)) >> 8); }
	static inline int mul_8bit(int a, int b) { int t = a * b + 128; return (t + (t >> 8)) >> 8; }
	static inline int lerp_8bit(int a, int b, int s) { assert(a >= 0 && a <= 255); assert(b >= 0 && b <= 255); assert(s >= 0 && s <= 255); return a + mul_8bit(b - a, s); }

	struct vec2F
	{
		float c[2];

		inline vec2F() {}

		inline vec2F(float s) { c[0] = s; c[1] = s; }
		inline vec2F(float x, float y) { c[0] = x; c[1] = y; }

		inline void set(float x, float y) { c[0] = x; c[1] = y; }

		inline float dot(const vec2F& o) const { return (c[0] * o.c[0]) + (c[1] * o.c[1]); }

		inline float operator[] (uint32_t index) const { assert(index < 2); return c[index]; }
		inline float& operator[] (uint32_t index) { assert(index < 2); return c[index]; }

		inline vec2F& clamp(float l, float h)
		{
			c[0] = basisu::clamp(c[0], l, h);
			c[1] = basisu::clamp(c[1], l, h);
			return *this;
		}

		static vec2F lerp(const vec2F& a, const vec2F& b, float s)
		{
			vec2F res;
			for (uint32_t i = 0; i < 2; i++)
				res[i] = basisu::lerp(a[i], b[i], s);
			return res;
		}
	};

	struct vec3F
	{
		float c[3];

		inline vec3F() {}

		inline vec3F(float s) { c[0] = s; c[1] = s; c[2] = s; }
		inline vec3F(float x, float y, float z) { c[0] = x; c[1] = y; c[2] = z; }

		inline void set(float x, float y, float z) { c[0] = x; c[1] = y; c[2] = z; }

		inline float dot(const vec3F& o) const { return (c[0] * o.c[0]) + (c[1] * o.c[1]) + (c[2] * o.c[2]); }

		inline float operator[] (uint32_t index) const { assert(index < 3); return c[index]; }
		inline float &operator[] (uint32_t index) { assert(index < 3); return c[index]; }

		inline vec3F& clamp(float l, float h)
		{
			c[0] = basisu::clamp(c[0], l, h);
			c[1] = basisu::clamp(c[1], l, h);
			c[2] = basisu::clamp(c[2], l, h);
			return *this;
		}

		static vec3F lerp(const vec3F& a, const vec3F& b, float s)
		{
			vec3F res;
			for (uint32_t i = 0; i < 3; i++)
				res[i] = basisu::lerp(a[i], b[i], s);
			return res;
		}

		inline float norm() const { return dot(*this); }
	};

	uint16_t crc16(const void* r, size_t size, uint16_t crc)
	{
		crc = ~crc;

		const uint8_t* p = static_cast<const uint8_t*>(r);
		for (; size; --size)
		{
			const uint16_t q = *p++ ^ (crc >> 8);
			uint16_t k = (q >> 4) ^ q;
			crc = (((crc << 8) ^ k) ^ (k << 5)) ^ (k << 12);
		}

		return static_cast<uint16_t>(~crc);
	}

	uint32_t hash_hsieh(const uint8_t* pBuf, size_t len)
	{
		if (!pBuf || !len)
			return 0;

		uint32_t h = static_cast<uint32_t>(len);

		const uint32_t bytes_left = len & 3;
		len >>= 2;

		while (len--)
		{
			const uint16_t* pWords = reinterpret_cast<const uint16_t*>(pBuf);

			h += pWords[0];

			const uint32_t t = (pWords[1] << 11) ^ h;
			h = (h << 16) ^ t;

			pBuf += sizeof(uint32_t);

			h += h >> 11;
		}

		switch (bytes_left)
		{
		case 1:
			h += *reinterpret_cast<const signed char*>(pBuf);
			h ^= h << 10;
			h += h >> 1;
			break;
		case 2:
			h += *reinterpret_cast<const uint16_t*>(pBuf);
			h ^= h << 11;
			h += h >> 17;
			break;
		case 3:
			h += *reinterpret_cast<const uint16_t*>(pBuf);
			h ^= h << 16;
			h ^= (static_cast<signed char>(pBuf[sizeof(uint16_t)])) << 18;
			h += h >> 11;
			break;
		default:
			break;
		}

		h ^= h << 3;
		h += h >> 5;
		h ^= h << 4;
		h += h >> 17;
		h ^= h << 25;
		h += h >> 6;

		return h;
	}

	struct vec4F
	{
		float c[4];

		inline void set(float x, float y, float z, float w) { c[0] = x; c[1] = y; c[2] = z; c[3] = w; }

		float operator[] (uint32_t index) const { assert(index < 4); return c[index]; }
		float& operator[] (uint32_t index) { assert(index < 4); return c[index]; }
	};
		
	enum etc_constants
	{
		cETC1BytesPerBlock = 8U,

		cETC1SelectorBits = 2U,
		cETC1SelectorValues = 1U << cETC1SelectorBits,
		cETC1SelectorMask = cETC1SelectorValues - 1U,

		cETC1BlockShift = 2U,
		cETC1BlockSize = 1U << cETC1BlockShift,

		cETC1LSBSelectorIndicesBitOffset = 0,
		cETC1MSBSelectorIndicesBitOffset = 16,

		cETC1FlipBitOffset = 32,
		cETC1DiffBitOffset = 33,

		cETC1IntenModifierNumBits = 3,
		cETC1IntenModifierValues = 1 << cETC1IntenModifierNumBits,
		cETC1RightIntenModifierTableBitOffset = 34,
		cETC1LeftIntenModifierTableBitOffset = 37,

		// Base+Delta encoding (5 bit bases, 3 bit delta)
		cETC1BaseColorCompNumBits = 5,
		cETC1BaseColorCompMax = 1 << cETC1BaseColorCompNumBits,

		cETC1DeltaColorCompNumBits = 3,
		cETC1DeltaColorComp = 1 << cETC1DeltaColorCompNumBits,
		cETC1DeltaColorCompMax = 1 << cETC1DeltaColorCompNumBits,

		cETC1BaseColor5RBitOffset = 59,
		cETC1BaseColor5GBitOffset = 51,
		cETC1BaseColor5BBitOffset = 43,

		cETC1DeltaColor3RBitOffset = 56,
		cETC1DeltaColor3GBitOffset = 48,
		cETC1DeltaColor3BBitOffset = 40,

		// Absolute (non-delta) encoding (two 4-bit per component bases)
		cETC1AbsColorCompNumBits = 4,
		cETC1AbsColorCompMax = 1 << cETC1AbsColorCompNumBits,

		cETC1AbsColor4R1BitOffset = 60,
		cETC1AbsColor4G1BitOffset = 52,
		cETC1AbsColor4B1BitOffset = 44,

		cETC1AbsColor4R2BitOffset = 56,
		cETC1AbsColor4G2BitOffset = 48,
		cETC1AbsColor4B2BitOffset = 40,

		cETC1ColorDeltaMin = -4,
		cETC1ColorDeltaMax = 3,

		// Delta3:
		// 0   1   2   3   4   5   6   7
		// 000 001 010 011 100 101 110 111
		// 0   1   2   3   -4  -3  -2  -1
	};

#define DECLARE_ETC1_INTEN_TABLE(name, N) \
	static const int name[cETC1IntenModifierValues][cETC1SelectorValues] = \
	{ \
		{ N * -8,  N * -2,   N * 2,   N * 8 },{ N * -17,  N * -5,  N * 5,  N * 17 },{ N * -29,  N * -9,   N * 9,  N * 29 },{ N * -42, N * -13, N * 13,  N * 42 }, \
		{ N * -60, N * -18, N * 18,  N * 60 },{ N * -80, N * -24, N * 24,  N * 80 },{ N * -106, N * -33, N * 33, N * 106 },{ N * -183, N * -47, N * 47, N * 183 } \
	};

	DECLARE_ETC1_INTEN_TABLE(g_etc1_inten_tables, 1);
	DECLARE_ETC1_INTEN_TABLE(g_etc1_inten_tables16, 16);
	DECLARE_ETC1_INTEN_TABLE(g_etc1_inten_tables48, 3 * 16);

	//const uint8_t g_etc1_to_selector_index[cETC1SelectorValues] = { 2, 3, 1, 0 };
	const uint8_t g_selector_index_to_etc1[cETC1SelectorValues] = { 3, 2, 0, 1 };
	
	static const uint8_t g_etc_5_to_8[32] = { 0, 8, 16, 24, 33, 41, 49, 57, 66, 74, 82, 90, 99, 107, 115, 123, 132, 140, 148, 156, 165, 173, 181, 189, 198, 206, 214, 222, 231, 239, 247, 255 };

	struct decoder_etc_block
	{
		// big endian uint64:
		// bit ofs:  56  48  40  32  24  16   8   0
		// byte ofs: b0, b1, b2, b3, b4, b5, b6, b7 
		union
		{
			uint64_t m_uint64;

			uint32_t m_uint32[2];

			uint8_t m_bytes[8];

			struct
			{
				signed m_dred2 : 3;
				uint32_t m_red1 : 5;

				signed m_dgreen2 : 3;
				uint32_t m_green1 : 5;

				signed m_dblue2 : 3;
				uint32_t m_blue1 : 5;

				uint32_t m_flip : 1;
				uint32_t m_diff : 1;
				uint32_t m_cw2 : 3;
				uint32_t m_cw1 : 3;

				uint32_t m_selectors;
			} m_differential;
		};

		inline void clear()
		{
			assert(sizeof(*this) == 8);
			basisu::clear_obj(*this);
		}

		inline void set_byte_bits(uint32_t ofs, uint32_t num, uint32_t bits)
		{
			assert((ofs + num) <= 64U);
			assert(num && (num < 32U));
			assert((ofs >> 3) == ((ofs + num - 1) >> 3));
			assert(bits < (1U << num));
			const uint32_t byte_ofs = 7 - (ofs >> 3);
			const uint32_t byte_bit_ofs = ofs & 7;
			const uint32_t mask = (1 << num) - 1;
			m_bytes[byte_ofs] &= ~(mask << byte_bit_ofs);
			m_bytes[byte_ofs] |= (bits << byte_bit_ofs);
		}

		inline void set_flip_bit(bool flip)
		{
			m_bytes[3] &= ~1;
			m_bytes[3] |= static_cast<uint8_t>(flip);
		}

		inline void set_diff_bit(bool diff)
		{
			m_bytes[3] &= ~2;
			m_bytes[3] |= (static_cast<uint32_t>(diff) << 1);
		}

		// Sets intensity modifier table (0-7) used by subblock subblock_id (0 or 1)
		inline void set_inten_table(uint32_t subblock_id, uint32_t t)
		{
			assert(subblock_id < 2);
			assert(t < 8);
			const uint32_t ofs = subblock_id ? 2 : 5;
			m_bytes[3] &= ~(7 << ofs);
			m_bytes[3] |= (t << ofs);
		}

		// Selector "val" ranges from 0-3 and is a direct index into g_etc1_inten_tables.
		inline void set_selector(uint32_t x, uint32_t y, uint32_t val)
		{
			assert((x | y | val) < 4);
			const uint32_t bit_index = x * 4 + y;

			uint8_t* p = &m_bytes[7 - (bit_index >> 3)];

			const uint32_t byte_bit_ofs = bit_index & 7;
			const uint32_t mask = 1 << byte_bit_ofs;

			static const uint8_t s_selector_index_to_etc1[4] = { 3, 2, 0, 1 };
			const uint32_t etc1_val = s_selector_index_to_etc1[val];

			const uint32_t lsb = etc1_val & 1;
			const uint32_t msb = etc1_val >> 1;

			p[0] &= ~mask;
			p[0] |= (lsb << byte_bit_ofs);

			p[-2] &= ~mask;
			p[-2] |= (msb << byte_bit_ofs);
		}

		// Returned encoded selector value ranges from 0-3 (this is NOT a direct index into g_etc1_inten_tables, see get_selector())
		inline uint32_t get_raw_selector(uint32_t x, uint32_t y) const
		{
			assert((x | y) < 4);

			const uint32_t bit_index = x * 4 + y;
			const uint32_t byte_bit_ofs = bit_index & 7;
			const uint8_t* p = &m_bytes[7 - (bit_index >> 3)];
			const uint32_t lsb = (p[0] >> byte_bit_ofs) & 1;
			const uint32_t msb = (p[-2] >> byte_bit_ofs) & 1;
			const uint32_t val = lsb | (msb << 1);

			return val;
		}

		// Returned selector value ranges from 0-3 and is a direct index into g_etc1_inten_tables.
		inline uint32_t get_selector(uint32_t x, uint32_t y) const
		{
			static const uint8_t s_etc1_to_selector_index[cETC1SelectorValues] = { 2, 3, 1, 0 };
			return s_etc1_to_selector_index[get_raw_selector(x, y)];
		}

		inline void set_raw_selector_bits(uint32_t bits)
		{
			m_bytes[4] = static_cast<uint8_t>(bits);
			m_bytes[5] = static_cast<uint8_t>(bits >> 8);
			m_bytes[6] = static_cast<uint8_t>(bits >> 16);
			m_bytes[7] = static_cast<uint8_t>(bits >> 24);
		}

		inline bool are_all_selectors_the_same() const
		{
			uint32_t v = *reinterpret_cast<const uint32_t*>(&m_bytes[4]);

			if ((v == 0xFFFFFFFF) || (v == 0xFFFF) || (!v) || (v == 0xFFFF0000))
				return true;

			return false;
		}

		inline void set_raw_selector_bits(uint8_t byte0, uint8_t byte1, uint8_t byte2, uint8_t byte3)
		{
			m_bytes[4] = byte0;
			m_bytes[5] = byte1;
			m_bytes[6] = byte2;
			m_bytes[7] = byte3;
		}

		inline uint32_t get_raw_selector_bits() const
		{
			return m_bytes[4] | (m_bytes[5] << 8) | (m_bytes[6] << 16) | (m_bytes[7] << 24);
		}

		inline void set_base4_color(uint32_t idx, uint16_t c)
		{
			if (idx)
			{
				set_byte_bits(cETC1AbsColor4R2BitOffset, 4, (c >> 8) & 15);
				set_byte_bits(cETC1AbsColor4G2BitOffset, 4, (c >> 4) & 15);
				set_byte_bits(cETC1AbsColor4B2BitOffset, 4, c & 15);
			}
			else
			{
				set_byte_bits(cETC1AbsColor4R1BitOffset, 4, (c >> 8) & 15);
				set_byte_bits(cETC1AbsColor4G1BitOffset, 4, (c >> 4) & 15);
				set_byte_bits(cETC1AbsColor4B1BitOffset, 4, c & 15);
			}
		}

		inline void set_base5_color(uint16_t c)
		{
			set_byte_bits(cETC1BaseColor5RBitOffset, 5, (c >> 10) & 31);
			set_byte_bits(cETC1BaseColor5GBitOffset, 5, (c >> 5) & 31);
			set_byte_bits(cETC1BaseColor5BBitOffset, 5, c & 31);
		}

		void set_delta3_color(uint16_t c)
		{
			set_byte_bits(cETC1DeltaColor3RBitOffset, 3, (c >> 6) & 7);
			set_byte_bits(cETC1DeltaColor3GBitOffset, 3, (c >> 3) & 7);
			set_byte_bits(cETC1DeltaColor3BBitOffset, 3, c & 7);
		}

		void set_block_color4(const color32& c0_unscaled, const color32& c1_unscaled)
		{
			set_diff_bit(false);

			set_base4_color(0, pack_color4(c0_unscaled, false));
			set_base4_color(1, pack_color4(c1_unscaled, false));
		}

		void set_block_color5(const color32& c0_unscaled, const color32& c1_unscaled)
		{
			set_diff_bit(true);

			set_base5_color(pack_color5(c0_unscaled, false));

			int dr = c1_unscaled.r - c0_unscaled.r;
			int dg = c1_unscaled.g - c0_unscaled.g;
			int db = c1_unscaled.b - c0_unscaled.b;

			set_delta3_color(pack_delta3(dr, dg, db));
		}

		bool set_block_color5_check(const color32& c0_unscaled, const color32& c1_unscaled)
		{
			set_diff_bit(true);

			set_base5_color(pack_color5(c0_unscaled, false));

			int dr = c1_unscaled.r - c0_unscaled.r;
			int dg = c1_unscaled.g - c0_unscaled.g;
			int db = c1_unscaled.b - c0_unscaled.b;

			if (((dr < cETC1ColorDeltaMin) || (dr > cETC1ColorDeltaMax)) ||
				((dg < cETC1ColorDeltaMin) || (dg > cETC1ColorDeltaMax)) ||
				((db < cETC1ColorDeltaMin) || (db > cETC1ColorDeltaMax)))
				return false;

			set_delta3_color(pack_delta3(dr, dg, db));

			return true;
		}

		inline uint32_t get_byte_bits(uint32_t ofs, uint32_t num) const
		{
			assert((ofs + num) <= 64U);
			assert(num && (num <= 8U));
			assert((ofs >> 3) == ((ofs + num - 1) >> 3));
			const uint32_t byte_ofs = 7 - (ofs >> 3);
			const uint32_t byte_bit_ofs = ofs & 7;
			return (m_bytes[byte_ofs] >> byte_bit_ofs) & ((1 << num) - 1);
		}

		inline uint16_t get_base5_color() const
		{
			const uint32_t r = get_byte_bits(cETC1BaseColor5RBitOffset, 5);
			const uint32_t g = get_byte_bits(cETC1BaseColor5GBitOffset, 5);
			const uint32_t b = get_byte_bits(cETC1BaseColor5BBitOffset, 5);
			return static_cast<uint16_t>(b | (g << 5U) | (r << 10U));
		}

		inline uint16_t get_base4_color(uint32_t idx) const
		{
			uint32_t r, g, b;
			if (idx)
			{
				r = get_byte_bits(cETC1AbsColor4R2BitOffset, 4);
				g = get_byte_bits(cETC1AbsColor4G2BitOffset, 4);
				b = get_byte_bits(cETC1AbsColor4B2BitOffset, 4);
			}
			else
			{
				r = get_byte_bits(cETC1AbsColor4R1BitOffset, 4);
				g = get_byte_bits(cETC1AbsColor4G1BitOffset, 4);
				b = get_byte_bits(cETC1AbsColor4B1BitOffset, 4);
			}
			return static_cast<uint16_t>(b | (g << 4U) | (r << 8U));
		}

		inline color32 get_base5_color_unscaled() const
		{
			return color32(m_differential.m_red1, m_differential.m_green1, m_differential.m_blue1, 255);
		}

		inline bool get_flip_bit() const
		{
			return (m_bytes[3] & 1) != 0;
		}

		inline bool get_diff_bit() const
		{
			return (m_bytes[3] & 2) != 0;
		}
				
		inline uint32_t get_inten_table(uint32_t subblock_id) const
		{
			assert(subblock_id < 2);
			const uint32_t ofs = subblock_id ? 2 : 5;
			return (m_bytes[3] >> ofs) & 7;
		}

		inline uint16_t get_delta3_color() const
		{
			const uint32_t r = get_byte_bits(cETC1DeltaColor3RBitOffset, 3);
			const uint32_t g = get_byte_bits(cETC1DeltaColor3GBitOffset, 3);
			const uint32_t b = get_byte_bits(cETC1DeltaColor3BBitOffset, 3);
			return static_cast<uint16_t>(b | (g << 3U) | (r << 6U));
		}
		
		void get_block_colors(color32* pBlock_colors, uint32_t subblock_index) const
		{
			color32 b;

			if (get_diff_bit())
			{
				if (subblock_index)
					unpack_color5(b, get_base5_color(), get_delta3_color(), true, 255);
				else
					unpack_color5(b, get_base5_color(), true);
			}
			else
			{
				b = unpack_color4(get_base4_color(subblock_index), true, 255);
			}

			const int* pInten_table = g_etc1_inten_tables[get_inten_table(subblock_index)];

			pBlock_colors[0].set_noclamp_rgba(clamp255(b.r + pInten_table[0]), clamp255(b.g + pInten_table[0]), clamp255(b.b + pInten_table[0]), 255);
			pBlock_colors[1].set_noclamp_rgba(clamp255(b.r + pInten_table[1]), clamp255(b.g + pInten_table[1]), clamp255(b.b + pInten_table[1]), 255);
			pBlock_colors[2].set_noclamp_rgba(clamp255(b.r + pInten_table[2]), clamp255(b.g + pInten_table[2]), clamp255(b.b + pInten_table[2]), 255);
			pBlock_colors[3].set_noclamp_rgba(clamp255(b.r + pInten_table[3]), clamp255(b.g + pInten_table[3]), clamp255(b.b + pInten_table[3]), 255);
		}

		static uint16_t pack_color4(const color32& color, bool scaled, uint32_t bias = 127U)
		{
			return pack_color4(color.r, color.g, color.b, scaled, bias);
		}

		static uint16_t pack_color4(uint32_t r, uint32_t g, uint32_t b, bool scaled, uint32_t bias = 127U)
		{
			if (scaled)
			{
				r = (r * 15U + bias) / 255U;
				g = (g * 15U + bias) / 255U;
				b = (b * 15U + bias) / 255U;
			}

			r = basisu::minimum(r, 15U);
			g = basisu::minimum(g, 15U);
			b = basisu::minimum(b, 15U);

			return static_cast<uint16_t>(b | (g << 4U) | (r << 8U));
		}

		static uint16_t pack_color5(const color32& color, bool scaled, uint32_t bias = 127U)
		{
			return pack_color5(color.r, color.g, color.b, scaled, bias);
		}

		static uint16_t pack_color5(uint32_t r, uint32_t g, uint32_t b, bool scaled, uint32_t bias = 127U)
		{
			if (scaled)
			{
				r = (r * 31U + bias) / 255U;
				g = (g * 31U + bias) / 255U;
				b = (b * 31U + bias) / 255U;
			}

			r = basisu::minimum(r, 31U);
			g = basisu::minimum(g, 31U);
			b = basisu::minimum(b, 31U);

			return static_cast<uint16_t>(b | (g << 5U) | (r << 10U));
		}

		uint16_t pack_delta3(const color32& color)
		{
			return pack_delta3(color.r, color.g, color.b);
		}

		uint16_t pack_delta3(int r, int g, int b)
		{
			assert((r >= cETC1ColorDeltaMin) && (r <= cETC1ColorDeltaMax));
			assert((g >= cETC1ColorDeltaMin) && (g <= cETC1ColorDeltaMax));
			assert((b >= cETC1ColorDeltaMin) && (b <= cETC1ColorDeltaMax));
			if (r < 0) r += 8;
			if (g < 0) g += 8;
			if (b < 0) b += 8;
			return static_cast<uint16_t>(b | (g << 3) | (r << 6));
		}

		static void unpack_delta3(int& r, int& g, int& b, uint16_t packed_delta3)
		{
			r = (packed_delta3 >> 6) & 7;
			g = (packed_delta3 >> 3) & 7;
			b = packed_delta3 & 7;
			if (r >= 4) r -= 8;
			if (g >= 4) g -= 8;
			if (b >= 4) b -= 8;
		}

		static color32 unpack_color5(uint16_t packed_color5, bool scaled, uint32_t alpha)
		{
			uint32_t b = packed_color5 & 31U;
			uint32_t g = (packed_color5 >> 5U) & 31U;
			uint32_t r = (packed_color5 >> 10U) & 31U;

			if (scaled)
			{
				b = (b << 3U) | (b >> 2U);
				g = (g << 3U) | (g >> 2U);
				r = (r << 3U) | (r >> 2U);
			}

			assert(alpha <= 255);

			return color32(cNoClamp, r, g, b, alpha);
		}

		static void unpack_color5(uint32_t& r, uint32_t& g, uint32_t& b, uint16_t packed_color5, bool scaled)
		{
			color32 c(unpack_color5(packed_color5, scaled, 0));
			r = c.r;
			g = c.g;
			b = c.b;
		}
				
		static void unpack_color5(color32& result, uint16_t packed_color5, bool scaled)
		{
			result = unpack_color5(packed_color5, scaled, 255);
		}

		static bool unpack_color5(color32& result, uint16_t packed_color5, uint16_t packed_delta3, bool scaled, uint32_t alpha)
		{
			int dr, dg, db;
			unpack_delta3(dr, dg, db, packed_delta3);

			int r = ((packed_color5 >> 10U) & 31U) + dr;
			int g = ((packed_color5 >> 5U) & 31U) + dg;
			int b = (packed_color5 & 31U) + db;

			bool success = true;
			if (static_cast<uint32_t>(r | g | b) > 31U)
			{
				success = false;
				r = basisu::clamp<int>(r, 0, 31);
				g = basisu::clamp<int>(g, 0, 31);
				b = basisu::clamp<int>(b, 0, 31);
			}

			if (scaled)
			{
				b = (b << 3U) | (b >> 2U);
				g = (g << 3U) | (g >> 2U);
				r = (r << 3U) | (r >> 2U);
			}

			result.set_noclamp_rgba(r, g, b, basisu::minimum(alpha, 255U));
			return success;
		}

		static color32 unpack_color4(uint16_t packed_color4, bool scaled, uint32_t alpha)
		{
			uint32_t b = packed_color4 & 15U;
			uint32_t g = (packed_color4 >> 4U) & 15U;
			uint32_t r = (packed_color4 >> 8U) & 15U;

			if (scaled)
			{
				b = (b << 4U) | b;
				g = (g << 4U) | g;
				r = (r << 4U) | r;
			}

			return color32(cNoClamp, r, g, b, basisu::minimum(alpha, 255U));
		}

		static void unpack_color4(uint32_t& r, uint32_t& g, uint32_t& b, uint16_t packed_color4, bool scaled)
		{
			color32 c(unpack_color4(packed_color4, scaled, 0));
			r = c.r;
			g = c.g;
			b = c.b;
		}

		static void get_diff_subblock_colors(color32* pDst, uint16_t packed_color5, uint32_t table_idx)
		{
			assert(table_idx < cETC1IntenModifierValues);
			const int* pInten_modifer_table = &g_etc1_inten_tables[table_idx][0];

			uint32_t r, g, b;
			unpack_color5(r, g, b, packed_color5, true);

			const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b);

			const int y0 = pInten_modifer_table[0];
			pDst[0].set(clamp255(ir + y0), clamp255(ig + y0), clamp255(ib + y0), 255);

			const int y1 = pInten_modifer_table[1];
			pDst[1].set(clamp255(ir + y1), clamp255(ig + y1), clamp255(ib + y1), 255);

			const int y2 = pInten_modifer_table[2];
			pDst[2].set(clamp255(ir + y2), clamp255(ig + y2), clamp255(ib + y2), 255);

			const int y3 = pInten_modifer_table[3];
			pDst[3].set(clamp255(ir + y3), clamp255(ig + y3), clamp255(ib + y3), 255);
		}

		static int clamp255(int x)
		{
			if (x & 0xFFFFFF00)
			{
				if (x < 0)
					x = 0;
				else if (x > 255)
					x = 255;
			}

			return x;
		}

		static void get_block_colors5(color32* pBlock_colors, const color32& base_color5, uint32_t inten_table)
		{
			color32 b(base_color5);

			b.r = (b.r << 3) | (b.r >> 2);
			b.g = (b.g << 3) | (b.g >> 2);
			b.b = (b.b << 3) | (b.b >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0].set(clamp255(b.r + pInten_table[0]), clamp255(b.g + pInten_table[0]), clamp255(b.b + pInten_table[0]), 255);
			pBlock_colors[1].set(clamp255(b.r + pInten_table[1]), clamp255(b.g + pInten_table[1]), clamp255(b.b + pInten_table[1]), 255);
			pBlock_colors[2].set(clamp255(b.r + pInten_table[2]), clamp255(b.g + pInten_table[2]), clamp255(b.b + pInten_table[2]), 255);
			pBlock_colors[3].set(clamp255(b.r + pInten_table[3]), clamp255(b.g + pInten_table[3]), clamp255(b.b + pInten_table[3]), 255);
		}

		static void get_block_color5(const color32& base_color5, uint32_t inten_table, uint32_t index, uint32_t& r, uint32_t &g, uint32_t &b)
		{
			assert(index < 4);

			uint32_t br = (base_color5.r << 3) | (base_color5.r >> 2);
			uint32_t bg = (base_color5.g << 3) | (base_color5.g >> 2);
			uint32_t bb = (base_color5.b << 3) | (base_color5.b >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			r = clamp255(br + pInten_table[index]);
			g = clamp255(bg + pInten_table[index]);
			b = clamp255(bb + pInten_table[index]);
		}

		static void get_block_color5_r(const color32& base_color5, uint32_t inten_table, uint32_t index, uint32_t &r)
		{
			assert(index < 4);
						
			uint32_t br = (base_color5.r << 3) | (base_color5.r >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			r = clamp255(br + pInten_table[index]);
		}

		static void get_block_colors5_g(int* pBlock_colors, const color32& base_color5, uint32_t inten_table)
		{
			const int g = (base_color5.g << 3) | (base_color5.g >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0] = clamp255(g + pInten_table[0]);
			pBlock_colors[1] = clamp255(g + pInten_table[1]);
			pBlock_colors[2] = clamp255(g + pInten_table[2]);
			pBlock_colors[3] = clamp255(g + pInten_table[3]);
		}

		static void get_block_colors5_bounds(color32* pBlock_colors, const color32& base_color5, uint32_t inten_table, uint32_t l = 0, uint32_t h = 3)
		{
			color32 b(base_color5);

			b.r = (b.r << 3) | (b.r >> 2);
			b.g = (b.g << 3) | (b.g >> 2);
			b.b = (b.b << 3) | (b.b >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0].set(clamp255(b.r + pInten_table[l]), clamp255(b.g + pInten_table[l]), clamp255(b.b + pInten_table[l]), 255);
			pBlock_colors[1].set(clamp255(b.r + pInten_table[h]), clamp255(b.g + pInten_table[h]), clamp255(b.b + pInten_table[h]), 255);
		}

		static void get_block_colors5_bounds_g(uint32_t* pBlock_colors, const color32& base_color5, uint32_t inten_table, uint32_t l = 0, uint32_t h = 3)
		{
			color32 b(base_color5);

			b.g = (b.g << 3) | (b.g >> 2);

			const int* pInten_table = g_etc1_inten_tables[inten_table];

			pBlock_colors[0] = clamp255(b.g + pInten_table[l]);
			pBlock_colors[1] = clamp255(b.g + pInten_table[h]);
		}
	};

	enum dxt_constants
	{
		cDXT1SelectorBits = 2U, cDXT1SelectorValues = 1U << cDXT1SelectorBits, cDXT1SelectorMask = cDXT1SelectorValues - 1U,
		cDXT5SelectorBits = 3U, cDXT5SelectorValues = 1U << cDXT5SelectorBits, cDXT5SelectorMask = cDXT5SelectorValues - 1U,
	};

	static const uint8_t g_etc1_x_selector_unpack[4][256] =
	{
		{
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
			0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
		},
		{
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
			0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1,
			2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3,
		},

		{
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
			2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3,
		},

		{
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
			2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
		}
	};

	struct dxt1_block
	{
		enum { cTotalEndpointBytes = 2, cTotalSelectorBytes = 4 };

		uint8_t m_low_color[cTotalEndpointBytes];
		uint8_t m_high_color[cTotalEndpointBytes];
		uint8_t m_selectors[cTotalSelectorBytes];

		inline void clear() { basisu::clear_obj(*this); }

		inline uint32_t get_high_color() const { return m_high_color[0] | (m_high_color[1] << 8U); }
		inline uint32_t get_low_color() const { return m_low_color[0] | (m_low_color[1] << 8U); }
		inline void set_low_color(uint16_t c) { m_low_color[0] = static_cast<uint8_t>(c & 0xFF); m_low_color[1] = static_cast<uint8_t>((c >> 8) & 0xFF); }
		inline void set_high_color(uint16_t c) { m_high_color[0] = static_cast<uint8_t>(c & 0xFF); m_high_color[1] = static_cast<uint8_t>((c >> 8) & 0xFF); }
		inline uint32_t get_selector(uint32_t x, uint32_t y) const { assert((x < 4U) && (y < 4U)); return (m_selectors[y] >> (x * cDXT1SelectorBits)) & cDXT1SelectorMask; }
		inline void set_selector(uint32_t x, uint32_t y, uint32_t val) { assert((x < 4U) && (y < 4U) && (val < 4U)); m_selectors[y] &= (~(cDXT1SelectorMask << (x * cDXT1SelectorBits))); m_selectors[y] |= (val << (x * cDXT1SelectorBits)); }

		static uint16_t pack_color(const color32& color, bool scaled, uint32_t bias = 127U)
		{
			uint32_t r = color.r, g = color.g, b = color.b;
			if (scaled)
			{
				r = (r * 31U + bias) / 255U;
				g = (g * 63U + bias) / 255U;
				b = (b * 31U + bias) / 255U;
			}
			return static_cast<uint16_t>(basisu::minimum(b, 31U) | (basisu::minimum(g, 63U) << 5U) | (basisu::minimum(r, 31U) << 11U));
		}

		static uint16_t pack_unscaled_color(uint32_t r, uint32_t g, uint32_t b) { return static_cast<uint16_t>(b | (g << 5U) | (r << 11U)); }
	};

	struct dxt_selector_range
	{
		uint32_t m_low;
		uint32_t m_high;
	};

	struct etc1_to_dxt1_56_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};

#if BASISD_SUPPORT_DXT1
	static dxt_selector_range g_etc1_to_dxt1_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },

		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1_TO_DXT1_SELECTOR_RANGES = sizeof(g_etc1_to_dxt1_selector_ranges) / sizeof(g_etc1_to_dxt1_selector_ranges[0]);

	static uint32_t g_etc1_to_dxt1_selector_range_index[4][4];

	const uint32_t NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1_to_dxt1_selector_mappings[NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 },
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};
	
	static uint8_t g_etc1_to_dxt1_selector_mappings_raw_dxt1_256[NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS][256];
	static uint8_t g_etc1_to_dxt1_selector_mappings_raw_dxt1_inv_256[NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS][256];

	static const etc1_to_dxt1_56_solution g_etc1_to_dxt_6[32 * 8 * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS * NUM_ETC1_TO_DXT1_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_dxt1_6.inc"
	};

	static const etc1_to_dxt1_56_solution g_etc1_to_dxt_5[32 * 8 * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS * NUM_ETC1_TO_DXT1_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_dxt1_5.inc"
	};
#endif // BASISD_SUPPORT_DXT1

#if BASISD_SUPPORT_DXT1 || BASISD_SUPPORT_UASTC
	// First saw the idea for optimal BC1 single-color block encoding using lookup tables in ryg_dxt.
	struct bc1_match_entry
	{
		uint8_t m_hi;
		uint8_t m_lo;
	};
	static bc1_match_entry g_bc1_match5_equals_1[256], g_bc1_match6_equals_1[256]; // selector 1, allow equals hi/lo
	static bc1_match_entry g_bc1_match5_equals_0[256], g_bc1_match6_equals_0[256]; // selector 0, allow equals hi/lo

	static void prepare_bc1_single_color_table(bc1_match_entry* pTable, const uint8_t* pExpand, int size0, int size1, int sel)
	{
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = 256;
			for (int lo = 0; lo < size0; lo++)
			{
				for (int hi = 0; hi < size1; hi++)
				{
					const int lo_e = pExpand[lo], hi_e = pExpand[hi];
					int e;

					if (sel == 1)
					{
						// Selector 1
						e = basisu::iabs(((hi_e * 2 + lo_e) / 3) - i);
						e += (basisu::iabs(hi_e - lo_e) * 3) / 100;
					}
					else
					{
						assert(sel == 0);

						// Selector 0
						e = basisu::iabs(hi_e - i);
					}

					if (e < lowest_e)
					{
						pTable[i].m_hi = static_cast<uint8_t>(hi);
						pTable[i].m_lo = static_cast<uint8_t>(lo);

						lowest_e = e;
					}

				} // hi
			} // lo
		}
	}
#endif

#if BASISD_WRITE_NEW_DXT1_TABLES
	static void create_etc1_to_dxt1_5_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_dxt1_5.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_DXT1_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_dxt1_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_dxt1_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 31; hi++)
						{
							for (uint32_t lo = 0; lo <= 31; lo++)
							{
								//if (lo == hi) continue;

								uint32_t colors[4];

								colors[0] = (lo << 3) | (lo >> 2);
								colors[3] = (hi << 3) | (hi >> 2);

								colors[1] = (colors[0] * 2 + colors[3]) / 3;
								colors[2] = (colors[3] * 2 + colors[0]) / 3;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_dxt1_selector_mappings[m][s]];

									total_err += err * err;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						assert(best_err <= 0xFFFF);

						//table[g + inten * 32].m_solutions[sr][m].m_lo = static_cast<uint8_t>(best_lo);
						//table[g + inten * 32].m_solutions[sr][m].m_hi = static_cast<uint8_t>(best_hi);
						//table[g + inten * 32].m_solutions[sr][m].m_err = static_cast<uint16_t>(best_err);

						//assert(best_lo != best_hi);
						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}

	static void create_etc1_to_dxt1_6_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_dxt1_6.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_DXT1_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_dxt1_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_dxt1_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 63; hi++)
						{
							for (uint32_t lo = 0; lo <= 63; lo++)
							{
								//if (lo == hi) continue;

								uint32_t colors[4];

								colors[0] = (lo << 2) | (lo >> 4);
								colors[3] = (hi << 2) | (hi >> 4);

								colors[1] = (colors[0] * 2 + colors[3]) / 3;
								colors[2] = (colors[3] * 2 + colors[0]) / 3;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_dxt1_selector_mappings[m][s]];

									total_err += err * err;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						assert(best_err <= 0xFFFF);

						//table[g + inten * 32].m_solutions[sr][m].m_lo = static_cast<uint8_t>(best_lo);
						//table[g + inten * 32].m_solutions[sr][m].m_hi = static_cast<uint8_t>(best_hi);
						//table[g + inten * 32].m_solutions[sr][m].m_err = static_cast<uint16_t>(best_err);

						//assert(best_lo != best_hi);
						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");

					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif

#if BASISD_SUPPORT_UASTC || BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11
	static const int8_t g_eac_modifier_table[16][8] =
	{
		{ -3, -6, -9, -15, 2, 5, 8, 14 },
		{ -3, -7, -10, -13, 2, 6, 9, 12 },
		{ -2, -5, -8, -13, 1, 4, 7, 12 },
		{ -2, -4, -6, -13, 1, 3, 5, 12 },
		{ -3, -6, -8, -12, 2, 5, 7, 11 },
		{ -3, -7, -9, -11, 2, 6, 8, 10 },
		{ -4, -7, -8, -11, 3, 6, 7, 10 },
		{ -3, -5, -8, -11, 2, 4, 7, 10 },

		{ -2, -6, -8, -10, 1, 5, 7, 9 },
		{ -2, -5, -8, -10, 1, 4, 7, 9 },
		{ -2, -4, -8, -10, 1, 3, 7, 9 },
		{ -2, -5, -7, -10, 1, 4, 6, 9 },
		{ -3, -4, -7, -10, 2, 3, 6, 9 },
		{ -1, -2, -3, -10, 0, 1, 2, 9 }, // entry 13
		{ -4, -6, -8, -9, 3, 5, 7, 8 },
		{ -3, -5, -7, -9, 2, 4, 6, 8 }
	};

	// Used by ETC2 EAC A8 and ETC2 EAC R11/RG11.
	struct eac_block
	{
		uint16_t m_base : 8;

		uint16_t m_table : 4;
		uint16_t m_multiplier : 4;

		uint8_t m_selectors[6];

		uint32_t get_selector(uint32_t x, uint32_t y) const
		{
			assert((x < 4) && (y < 4));

			const uint32_t ofs = 45 - (y + x * 4) * 3;

			const uint64_t pixels = get_selector_bits();

			return (pixels >> ofs) & 7;
		}

		void set_selector(uint32_t x, uint32_t y, uint32_t s)
		{
			assert((x < 4) && (y < 4) && (s < 8));

			const uint32_t ofs = 45 - (y + x * 4) * 3;

			uint64_t pixels = get_selector_bits();

			pixels &= ~(7ULL << ofs);
			pixels |= (static_cast<uint64_t>(s) << ofs);

			set_selector_bits(pixels);
		}

		uint64_t get_selector_bits() const
		{
			uint64_t pixels = ((uint64_t)m_selectors[0] << 40) | ((uint64_t)m_selectors[1] << 32) |
				((uint64_t)m_selectors[2] << 24) |
				((uint64_t)m_selectors[3] << 16) | ((uint64_t)m_selectors[4] << 8) | m_selectors[5];
			return pixels;
		}

		void set_selector_bits(uint64_t pixels)
		{
			m_selectors[0] = (uint8_t)(pixels >> 40);
			m_selectors[1] = (uint8_t)(pixels >> 32);
			m_selectors[2] = (uint8_t)(pixels >> 24);
			m_selectors[3] = (uint8_t)(pixels >> 16);
			m_selectors[4] = (uint8_t)(pixels >> 8);
			m_selectors[5] = (uint8_t)(pixels);
		}
	};

#endif // #if BASISD_SUPPORT_UASTC BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11

#if BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11
	static const dxt_selector_range s_etc2_eac_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },
	};

	const uint32_t NUM_ETC2_EAC_SELECTOR_RANGES = sizeof(s_etc2_eac_selector_ranges) / sizeof(s_etc2_eac_selector_ranges[0]);

	struct etc1_g_to_eac_conversion
	{
		uint8_t m_base;
		uint8_t m_table_mul; // mul*16+table
		uint16_t m_trans; // translates ETC1 selectors to ETC2_EAC_A8
	};
#endif // BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_ETC2_EAC_RG11

#if BASISD_SUPPORT_ETC2_EAC_A8

#if BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
	struct pack_eac_a8_results
	{
		uint32_t m_base;
		uint32_t m_table;
		uint32_t m_multiplier;
		basisu::vector<uint8_t> m_selectors;
		basisu::vector<uint8_t> m_selectors_temp;
	};

	static uint64_t pack_eac_a8_exhaustive(pack_eac_a8_results& results, const uint8_t* pPixels, uint32_t num_pixels)
	{
		results.m_selectors.resize(num_pixels);
		results.m_selectors_temp.resize(num_pixels);

		uint64_t best_err = UINT64_MAX;

		for (uint32_t base_color = 0; base_color < 256; base_color++)
		{
			for (uint32_t multiplier = 1; multiplier < 16; multiplier++)
			{
				for (uint32_t table = 0; table < 16; table++)
				{
					uint64_t total_err = 0;

					for (uint32_t i = 0; i < num_pixels; i++)
					{
						const int a = pPixels[i];

						uint32_t best_s_err = UINT32_MAX;
						uint32_t best_s = 0;
						for (uint32_t s = 0; s < 8; s++)
						{
							int v = (int)multiplier * g_eac_modifier_table[table][s] + (int)base_color;
							if (v < 0)
								v = 0;
							else if (v > 255)
								v = 255;

							uint32_t err = abs(a - v);
							if (err < best_s_err)
							{
								best_s_err = err;
								best_s = s;
							}
						}

						results.m_selectors_temp[i] = static_cast<uint8_t>(best_s);

						total_err += best_s_err * best_s_err;
						if (total_err >= best_err)
							break;
					}

					if (total_err < best_err)
					{
						best_err = total_err;
						results.m_base = base_color;
						results.m_multiplier = multiplier;
						results.m_table = table;
						results.m_selectors.swap(results.m_selectors_temp);
					}

				} // table

			} // multiplier

		} // base_color

		return best_err;
	}
#endif // BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
		
	static
#if !BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES		
		const
#endif
		etc1_g_to_eac_conversion s_etc1_g_to_etc2_a8[32 * 8][NUM_ETC2_EAC_SELECTOR_RANGES] =
	{
		{ { 0,1,3328 },{ 0,1,3328 },{ 0,1,256 },{ 0,1,256 } },
		{ { 0,226,3936 },{ 0,226,3936 },{ 0,81,488 },{ 0,81,488 } },
		{ { 6,178,4012 },{ 6,178,4008 },{ 0,146,501 },{ 0,130,496 } },
		{ { 14,178,4012 },{ 14,178,4008 },{ 8,146,501 },{ 6,82,496 } },
		{ { 23,178,4012 },{ 23,178,4008 },{ 17,146,501 },{ 3,228,496 } },
		{ { 31,178,4012 },{ 31,178,4008 },{ 25,146,501 },{ 11,228,496 } },
		{ { 39,178,4012 },{ 39,178,4008 },{ 33,146,501 },{ 19,228,496 } },
		{ { 47,178,4012 },{ 47,178,4008 },{ 41,146,501 },{ 27,228,496 } },
		{ { 56,178,4012 },{ 56,178,4008 },{ 50,146,501 },{ 36,228,496 } },
		{ { 64,178,4012 },{ 64,178,4008 },{ 58,146,501 },{ 44,228,496 } },
		{ { 72,178,4012 },{ 72,178,4008 },{ 66,146,501 },{ 52,228,496 } },
		{ { 80,178,4012 },{ 80,178,4008 },{ 74,146,501 },{ 60,228,496 } },
		{ { 89,178,4012 },{ 89,178,4008 },{ 83,146,501 },{ 69,228,496 } },
		{ { 97,178,4012 },{ 97,178,4008 },{ 91,146,501 },{ 77,228,496 } },
		{ { 105,178,4012 },{ 105,178,4008 },{ 99,146,501 },{ 85,228,496 } },
		{ { 113,178,4012 },{ 113,178,4008 },{ 107,146,501 },{ 93,228,496 } },
		{ { 122,178,4012 },{ 122,178,4008 },{ 116,146,501 },{ 102,228,496 } },
		{ { 130,178,4012 },{ 130,178,4008 },{ 124,146,501 },{ 110,228,496 } },
		{ { 138,178,4012 },{ 138,178,4008 },{ 132,146,501 },{ 118,228,496 } },
		{ { 146,178,4012 },{ 146,178,4008 },{ 140,146,501 },{ 126,228,496 } },
		{ { 155,178,4012 },{ 155,178,4008 },{ 149,146,501 },{ 135,228,496 } },
		{ { 163,178,4012 },{ 163,178,4008 },{ 157,146,501 },{ 143,228,496 } },
		{ { 171,178,4012 },{ 171,178,4008 },{ 165,146,501 },{ 151,228,496 } },
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		{ { 169,12,3395 },{ 198,21,3928 },{ 85,44,490 },{ 168,21,456 } },
		{ { 113,95,4001 },{ 201,69,3992 },{ 125,8,483 },{ 176,21,456 } },
		{ { 122,95,4001 },{ 200,21,3984 },{ 134,8,483 },{ 185,21,456 } },
		{ { 142,8,4067 },{ 208,21,3984 },{ 142,8,483 },{ 193,21,456 } },
		{ { 151,8,4067 },{ 47,15,4080 },{ 151,8,483 },{ 47,15,496 } },
		{ { 159,8,4067 },{ 55,15,4080 },{ 159,8,483 },{ 55,15,496 } },
		{ { 168,8,4067 },{ 64,15,4080 },{ 168,8,483 },{ 64,15,496 } },
		{ { 160,40,4075 },{ 72,15,4080 },{ 160,40,491 },{ 72,15,496 } },
		{ { 168,40,4075 },{ 80,15,4080 },{ 168,40,491 },{ 80,15,496 } },
		{ { 144,8,4082 },{ 88,15,4080 },{ 144,8,498 },{ 88,15,496 } }
	};
#endif // BASISD_SUPPORT_ETC2_EAC_A8

#if BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
	static void create_etc2_eac_a8_conversion_table()
	{
		FILE* pFile = fopen("basisu_decoder_tables_etc2_eac_a8.inc", "w");

		for (uint32_t inten = 0; inten < 8; inten++)
		{
			for (uint32_t base = 0; base < 32; base++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(base, base, base, 255), false), inten);

				fprintf(pFile, "{");

				for (uint32_t sel_range = 0; sel_range < NUM_ETC2_EAC_SELECTOR_RANGES; sel_range++)
				{
					const uint32_t low_selector = s_etc2_eac_selector_ranges[sel_range].m_low;
					const uint32_t high_selector = s_etc2_eac_selector_ranges[sel_range].m_high;

					// We have a ETC1 base color and intensity, and a used selector range from low_selector-high_selector.
					// Now find the best ETC2 EAC A8 base/table/multiplier that fits these colors.

					uint8_t pixels[4];
					uint32_t num_pixels = 0;
					for (uint32_t s = low_selector; s <= high_selector; s++)
						pixels[num_pixels++] = block_colors[s].g;

					pack_eac_a8_results pack_results;
					pack_eac_a8_exhaustive(pack_results, pixels, num_pixels);

					etc1_g_to_eac_conversion& c = s_etc1_g_to_etc2_a8[base + inten * 32][sel_range];

					c.m_base = pack_results.m_base;
					c.m_table_mul = pack_results.m_table * 16 + pack_results.m_multiplier;
					c.m_trans = 0;

					for (uint32_t s = 0; s < 4; s++)
					{
						if ((s < low_selector) || (s > high_selector))
							continue;

						uint32_t etc2_selector = pack_results.m_selectors[s - low_selector];

						c.m_trans |= (etc2_selector << (s * 3));
					}

					fprintf(pFile, "{%u,%u,%u}", c.m_base, c.m_table_mul, c.m_trans);
					if (sel_range < (NUM_ETC2_EAC_SELECTOR_RANGES - 1))
						fprintf(pFile, ",");
				}

				fprintf(pFile, "},\n");
			}
		}

		fclose(pFile);
	}
#endif

#if BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES
	struct pack_eac_r11_results
	{
		uint32_t m_base;
		uint32_t m_table;
		uint32_t m_multiplier;
		basisu::vector<uint8_t> m_selectors;
		basisu::vector<uint8_t> m_selectors_temp;
	};

	static uint64_t pack_eac_r11_exhaustive(pack_eac_r11_results& results, const uint8_t* pPixels, uint32_t num_pixels)
	{
		results.m_selectors.resize(num_pixels);
		results.m_selectors_temp.resize(num_pixels);

		uint64_t best_err = UINT64_MAX;

		for (uint32_t base_color = 0; base_color < 256; base_color++)
		{
			for (uint32_t multiplier = 0; multiplier < 16; multiplier++)
			{
				for (uint32_t table = 0; table < 16; table++)
				{
					uint64_t total_err = 0;

					for (uint32_t i = 0; i < num_pixels; i++)
					{
						// Convert 8-bit input to 11-bits
						const int a = (pPixels[i] * 2047 + 128) / 255;

						uint32_t best_s_err = UINT32_MAX;
						uint32_t best_s = 0;
						for (uint32_t s = 0; s < 8; s++)
						{
							int v = (int)(multiplier ? (multiplier * 8) : 1) * g_eac_modifier_table[table][s] + (int)base_color * 8 + 4;
							if (v < 0)
								v = 0;
							else if (v > 2047)
								v = 2047;

							uint32_t err = abs(a - v);
							if (err < best_s_err)
							{
								best_s_err = err;
								best_s = s;
							}
						}

						results.m_selectors_temp[i] = static_cast<uint8_t>(best_s);

						total_err += best_s_err * best_s_err;
						if (total_err >= best_err)
							break;
					}

					if (total_err < best_err)
					{
						best_err = total_err;
						results.m_base = base_color;
						results.m_multiplier = multiplier;
						results.m_table = table;
						results.m_selectors.swap(results.m_selectors_temp);
					}

				} // table

			} // multiplier

		} // base_color

		return best_err;
	}

	static void create_etc2_eac_r11_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_decoder_tables_etc2_eac_r11.inc", "w");

		for (uint32_t inten = 0; inten < 8; inten++)
		{
			for (uint32_t base = 0; base < 32; base++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(base, base, base, 255), false), inten);

				fprintf(pFile, "{");

				for (uint32_t sel_range = 0; sel_range < NUM_ETC2_EAC_SELECTOR_RANGES; sel_range++)
				{
					const uint32_t low_selector = s_etc2_eac_selector_ranges[sel_range].m_low;
					const uint32_t high_selector = s_etc2_eac_selector_ranges[sel_range].m_high;

					// We have a ETC1 base color and intensity, and a used selector range from low_selector-high_selector.
					// Now find the best ETC2 EAC R11 base/table/multiplier that fits these colors.

					uint8_t pixels[4];
					uint32_t num_pixels = 0;
					for (uint32_t s = low_selector; s <= high_selector; s++)
						pixels[num_pixels++] = block_colors[s].g;

					pack_eac_r11_results pack_results;
					pack_eac_r11_exhaustive(pack_results, pixels, num_pixels);

					etc1_g_to_eac_conversion c;

					c.m_base = (uint8_t)pack_results.m_base;
					c.m_table_mul = (uint8_t)(pack_results.m_table * 16 + pack_results.m_multiplier);
					c.m_trans = 0;

					for (uint32_t s = 0; s < 4; s++)
					{
						if ((s < low_selector) || (s > high_selector))
							continue;

						uint32_t etc2_selector = pack_results.m_selectors[s - low_selector];

						c.m_trans |= (etc2_selector << (s * 3));
					}

					fprintf(pFile, "{%u,%u,%u}", c.m_base, c.m_table_mul, c.m_trans);
					if (sel_range < (NUM_ETC2_EAC_SELECTOR_RANGES - 1))
						fprintf(pFile, ",");
				}

				fprintf(pFile, "},\n");
			}
		}

		fclose(pFile);
	}
#endif // BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES

#if BASISD_WRITE_NEW_ASTC_TABLES
	static void create_etc1_to_astc_conversion_table_0_47();
	static void create_etc1_to_astc_conversion_table_0_255();
#endif

#if BASISD_SUPPORT_ASTC
	static void transcoder_init_astc();
#endif

#if BASISD_WRITE_NEW_BC7_MODE5_TABLES
	static void create_etc1_to_bc7_m5_color_conversion_table();
	static void create_etc1_to_bc7_m5_alpha_conversion_table();
#endif

#if BASISD_SUPPORT_BC7_MODE5
	static void transcoder_init_bc7_mode5();
#endif

#if BASISD_WRITE_NEW_ATC_TABLES
	static void create_etc1s_to_atc_conversion_tables();
#endif

#if BASISD_SUPPORT_ATC
	static void transcoder_init_atc();
#endif

#if BASISD_SUPPORT_PVRTC2
	static void transcoder_init_pvrtc2();
#endif

#if BASISD_SUPPORT_UASTC
	void uastc_init();
#endif

#if BASISD_SUPPORT_UASTC_HDR	
	namespace astc_6x6_hdr
	{
		static void init_quantize_tables();
		static void fast_encode_bc6h_init();
	}
#endif

#if BASISD_SUPPORT_BC7_MODE5
	namespace bc7_mode_5_encoder
	{
		void encode_bc7_mode5_init();
	}
#endif

	namespace astc_ldr_t
	{
		void init_transcoding_tables();
	}

	static bool g_transcoder_initialized;
		
	// Library global initialization. Requires ~9 milliseconds when compiled and executed natively on a Core i7 2.2 GHz.
	// If this is too slow, these computed tables can easilky be moved to be compiled in.
	void basisu_transcoder_init()
	{
		if (g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::basisu_transcoder_init: Called more than once\n");      
			return;
		}
         
		BASISU_DEVEL_ERROR("basisu_transcoder::basisu_transcoder_init: Initializing (this is not an error)\n");      

#if BASISD_SUPPORT_UASTC
		uastc_init();
#endif

#if BASISD_SUPPORT_UASTC_HDR
		// TODO: Examine this, optimize for startup time/mem utilization.
		// XUASTC LDR decompressors need the rank tables
		astc_helpers::init_tables();

		astc_hdr_core_init();
#endif

#if BASISD_SUPPORT_ASTC
		transcoder_init_astc();
#endif
				
#if BASISD_WRITE_NEW_ASTC_TABLES
		create_etc1_to_astc_conversion_table_0_47();
		create_etc1_to_astc_conversion_table_0_255();
		exit(0);
#endif

#if BASISD_WRITE_NEW_BC7_MODE5_TABLES
		create_etc1_to_bc7_m5_color_conversion_table();
		create_etc1_to_bc7_m5_alpha_conversion_table();
		exit(0);
#endif

#if BASISD_WRITE_NEW_DXT1_TABLES
		create_etc1_to_dxt1_5_conversion_table();
		create_etc1_to_dxt1_6_conversion_table();
		exit(0);
#endif

#if BASISD_WRITE_NEW_ETC2_EAC_A8_TABLES
		create_etc2_eac_a8_conversion_table();
		exit(0);
#endif

#if BASISD_WRITE_NEW_ATC_TABLES
		create_etc1s_to_atc_conversion_tables();
		exit(0);
#endif

#if BASISD_WRITE_NEW_ETC2_EAC_R11_TABLES
		create_etc2_eac_r11_conversion_table();
		exit(0);
#endif

#if BASISD_SUPPORT_DXT1 || BASISD_SUPPORT_UASTC
		uint8_t bc1_expand5[32];
		for (int i = 0; i < 32; i++)
			bc1_expand5[i] = static_cast<uint8_t>((i << 3) | (i >> 2));
		prepare_bc1_single_color_table(g_bc1_match5_equals_1, bc1_expand5, 32, 32, 1);
		prepare_bc1_single_color_table(g_bc1_match5_equals_0, bc1_expand5, 1, 32, 0);

		uint8_t bc1_expand6[64];
		for (int i = 0; i < 64; i++)
			bc1_expand6[i] = static_cast<uint8_t>((i << 2) | (i >> 4));
		prepare_bc1_single_color_table(g_bc1_match6_equals_1, bc1_expand6, 64, 64, 1);
		prepare_bc1_single_color_table(g_bc1_match6_equals_0, bc1_expand6, 1, 64, 0);

#if 0
		for (uint32_t i = 0; i < 256; i++)
		{
			printf("%u %u %u\n", i, (i * 63 + 127) / 255, g_bc1_match6_equals_0[i].m_hi);
		}
		exit(0);
#endif

#endif

#if BASISD_SUPPORT_DXT1
		for (uint32_t i = 0; i < NUM_ETC1_TO_DXT1_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_dxt1_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_dxt1_selector_ranges[i].m_high;
			g_etc1_to_dxt1_selector_range_index[l][h] = i;
		}

		for (uint32_t sm = 0; sm < NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS; sm++)
		{
			uint8_t etc1_to_dxt1_selector_mappings_raw_dxt1[4];
			uint8_t etc1_to_dxt1_selector_mappings_raw_dxt1_inv[4];

			for (uint32_t j = 0; j < 4; j++)
			{
				static const uint8_t s_linear_dxt1_to_dxt1[4] = { 0, 2, 3, 1 };
				static const uint8_t s_dxt1_inverted_xlat[4] = { 1, 0, 3, 2 };

				etc1_to_dxt1_selector_mappings_raw_dxt1[j] = (uint8_t)s_linear_dxt1_to_dxt1[g_etc1_to_dxt1_selector_mappings[sm][j]];
				etc1_to_dxt1_selector_mappings_raw_dxt1_inv[j] = (uint8_t)s_dxt1_inverted_xlat[etc1_to_dxt1_selector_mappings_raw_dxt1[j]];
			}

			for (uint32_t i = 0; i < 256; i++)
			{
				uint32_t k = 0, k_inv = 0;
				for (uint32_t s = 0; s < 4; s++)
				{
					k |= (etc1_to_dxt1_selector_mappings_raw_dxt1[(i >> (s * 2)) & 3] << (s * 2));
					k_inv |= (etc1_to_dxt1_selector_mappings_raw_dxt1_inv[(i >> (s * 2)) & 3] << (s * 2));
				}
				g_etc1_to_dxt1_selector_mappings_raw_dxt1_256[sm][i] = (uint8_t)k;
				g_etc1_to_dxt1_selector_mappings_raw_dxt1_inv_256[sm][i] = (uint8_t)k_inv;
			}
		}
#endif

#if BASISD_SUPPORT_BC7_MODE5
		transcoder_init_bc7_mode5();
#endif

#if BASISD_SUPPORT_ATC
		transcoder_init_atc();
#endif

#if BASISD_SUPPORT_PVRTC2
		transcoder_init_pvrtc2();
#endif

#if BASISD_SUPPORT_UASTC_HDR
		bc6h_enc_init();
		astc_6x6_hdr::init_quantize_tables();
		fast_encode_bc6h_init();
#endif
		
#if BASISD_SUPPORT_BC7_MODE5
		bc7_mode_5_encoder::encode_bc7_mode5_init();
#endif

#if BASISD_SUPPORT_XUASTC
		// TODO: XUASTC support macro
		astc_ldr_t::init();
		
		astc_ldr_t::init_transcoding_tables();

		// Used by arith encoder/decoder
		arith_fastbits_f32::init();
								
		// Used by astc ldr transcoding
		bc7f::init();
		bc7u::init_weight_quant();
		etc1f::init();
#endif

		g_transcoder_initialized = true;
	}

#if BASISD_SUPPORT_DXT1
	static void convert_etc1s_to_dxt1(dxt1_block* pDst_block, const endpoint *pEndpoints, const selector* pSelector, bool use_threecolor_blocks)
	{
#if !BASISD_WRITE_NEW_DXT1_TABLES
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			uint32_t mask = 0xAA;
			uint32_t max16 = (g_bc1_match5_equals_1[r].m_hi << 11) | (g_bc1_match6_equals_1[g].m_hi << 5) | g_bc1_match5_equals_1[b].m_hi;
			uint32_t min16 = (g_bc1_match5_equals_1[r].m_lo << 11) | (g_bc1_match6_equals_1[g].m_lo << 5) | g_bc1_match5_equals_1[b].m_lo;

			if ((!use_threecolor_blocks) && (min16 == max16))
			{
				// This is an annoying edge case that impacts BC3.
				// This is to guarantee that BC3 blocks never use punchthrough alpha (3 color) mode, which isn't supported on some (all?) GPU's.
				mask = 0;

				// Make l > h
				if (min16 > 0)
					min16--;
				else
				{
					// l = h = 0
					assert(min16 == max16 && max16 == 0);

					max16 = 1;
					min16 = 0;
					mask = 0x55;
				}

				assert(max16 > min16);
			}

			if (max16 < min16)
			{
				std::swap(max16, min16);
				mask ^= 0x55;
			}

			pDst_block->set_low_color(static_cast<uint16_t>(max16));
			pDst_block->set_high_color(static_cast<uint16_t>(min16));
			pDst_block->m_selectors[0] = static_cast<uint8_t>(mask);
			pDst_block->m_selectors[1] = static_cast<uint8_t>(mask);
			pDst_block->m_selectors[2] = static_cast<uint8_t>(mask);
			pDst_block->m_selectors[3] = static_cast<uint8_t>(mask);

			return;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			uint32_t max16 = (g_bc1_match5_equals_0[r0].m_hi << 11) | (g_bc1_match6_equals_0[g0].m_hi << 5) | g_bc1_match5_equals_0[b0].m_hi;
			uint32_t min16 = (g_bc1_match5_equals_0[r1].m_hi << 11) | (g_bc1_match6_equals_0[g1].m_hi << 5) | g_bc1_match5_equals_0[b1].m_hi;

			uint32_t l = 0, h = 1;

			if (min16 == max16)
			{
				// Make l > h
				if (min16 > 0)
				{
					min16--;

					l = 0;
					h = 0;
				}
				else
				{
					// l = h = 0
					assert(min16 == max16 && max16 == 0);

					max16 = 1;
					min16 = 0;

					l = 1;
					h = 1;
				}

				assert(max16 > min16);
			}

			if (max16 < min16)
			{
				std::swap(max16, min16);
				l = 1;
				h = 0;
			}

			pDst_block->set_low_color((uint16_t)max16);
			pDst_block->set_high_color((uint16_t)min16);

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					pDst_block->set_selector(x, y, (s == 3) ? h : l);
				}
			}

			return;
		}

		const uint32_t selector_range_table = g_etc1_to_dxt1_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1_to_dxt1_56_solution* pTable_r = &g_etc1_to_dxt_5[(inten_table * 32 + base_color.r) * (NUM_ETC1_TO_DXT1_SELECTOR_RANGES * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS];
		const etc1_to_dxt1_56_solution* pTable_g = &g_etc1_to_dxt_6[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_DXT1_SELECTOR_RANGES * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS];
		const etc1_to_dxt1_56_solution* pTable_b = &g_etc1_to_dxt_5[(inten_table * 32 + base_color.b) * (NUM_ETC1_TO_DXT1_SELECTOR_RANGES * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1_TO_DXT1_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		uint32_t l = dxt1_block::pack_unscaled_color(pTable_r[best_mapping].m_lo, pTable_g[best_mapping].m_lo, pTable_b[best_mapping].m_lo);
		uint32_t h = dxt1_block::pack_unscaled_color(pTable_r[best_mapping].m_hi, pTable_g[best_mapping].m_hi, pTable_b[best_mapping].m_hi);

		const uint8_t* pSelectors_xlat_256 = &g_etc1_to_dxt1_selector_mappings_raw_dxt1_256[best_mapping][0];

		if (l < h)
		{
			std::swap(l, h);
			pSelectors_xlat_256 = &g_etc1_to_dxt1_selector_mappings_raw_dxt1_inv_256[best_mapping][0];
		}
				
		pDst_block->set_low_color(static_cast<uint16_t>(l));
		pDst_block->set_high_color(static_cast<uint16_t>(h));

		if (l == h)
		{
			uint8_t mask = 0;

			if (!use_threecolor_blocks)
			{
				// This is an annoying edge case that impacts BC3.

				// Make l > h
				if (h > 0)
					h--;
				else
				{
					// l = h = 0
					assert(l == h && h == 0);

					h = 0;
					l = 1;
					mask = 0x55;
				}

				assert(l > h);
				pDst_block->set_low_color(static_cast<uint16_t>(l));
				pDst_block->set_high_color(static_cast<uint16_t>(h));
			}

			pDst_block->m_selectors[0] = mask;
			pDst_block->m_selectors[1] = mask;
			pDst_block->m_selectors[2] = mask;
			pDst_block->m_selectors[3] = mask;

			return;
		}

		pDst_block->m_selectors[0] = pSelectors_xlat_256[pSelector->m_selectors[0]];
		pDst_block->m_selectors[1] = pSelectors_xlat_256[pSelector->m_selectors[1]];
		pDst_block->m_selectors[2] = pSelectors_xlat_256[pSelector->m_selectors[2]];
		pDst_block->m_selectors[3] = pSelectors_xlat_256[pSelector->m_selectors[3]];
#endif
	}

#if BASISD_ENABLE_DEBUG_FLAGS
	static void convert_etc1s_to_dxt1_vis(dxt1_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector, bool use_threecolor_blocks)
	{
		convert_etc1s_to_dxt1(pDst_block, pEndpoints, pSelector, use_threecolor_blocks);

		if (g_debug_flags & cDebugFlagVisBC1Sels)
		{
			uint32_t l = dxt1_block::pack_unscaled_color(31, 63, 31);
			uint32_t h = dxt1_block::pack_unscaled_color(0, 0, 0);
			pDst_block->set_low_color(static_cast<uint16_t>(l));
			pDst_block->set_high_color(static_cast<uint16_t>(h));
		}
		else if (g_debug_flags & cDebugFlagVisBC1Endpoints)
		{
			for (uint32_t y = 0; y < 4; y++)
				for (uint32_t x = 0; x < 4; x++)
					pDst_block->set_selector(x, y, (y < 2) ? 0 : 1);
		}
	}
#endif
#endif

#if BASISD_SUPPORT_FXT1
	struct fxt1_block
	{
		union
		{
			struct
			{
				uint64_t m_t00 : 2;
				uint64_t m_t01 : 2;
				uint64_t m_t02 : 2;
				uint64_t m_t03 : 2;
				uint64_t m_t04 : 2;
				uint64_t m_t05 : 2;
				uint64_t m_t06 : 2;
				uint64_t m_t07 : 2;
				uint64_t m_t08 : 2;
				uint64_t m_t09 : 2;
				uint64_t m_t10 : 2;
				uint64_t m_t11 : 2;
				uint64_t m_t12 : 2;
				uint64_t m_t13 : 2;
				uint64_t m_t14 : 2;
				uint64_t m_t15 : 2;
				uint64_t m_t16 : 2;
				uint64_t m_t17 : 2;
				uint64_t m_t18 : 2;
				uint64_t m_t19 : 2;
				uint64_t m_t20 : 2;
				uint64_t m_t21 : 2;
				uint64_t m_t22 : 2;
				uint64_t m_t23 : 2;
				uint64_t m_t24 : 2;
				uint64_t m_t25 : 2;
				uint64_t m_t26 : 2;
				uint64_t m_t27 : 2;
				uint64_t m_t28 : 2;
				uint64_t m_t29 : 2;
				uint64_t m_t30 : 2;
				uint64_t m_t31 : 2;
			} m_lo;
			uint64_t m_lo_bits;
			uint8_t m_sels[8];
		};
		union
		{
			struct
			{
#ifdef BASISU_USE_ORIGINAL_3DFX_FXT1_ENCODING
				uint64_t m_b1 : 5;
				uint64_t m_g1 : 5;
				uint64_t m_r1 : 5;
				uint64_t m_b0 : 5;
				uint64_t m_g0 : 5;
				uint64_t m_r0 : 5;
				uint64_t m_b3 : 5;
				uint64_t m_g3 : 5;
				uint64_t m_r3 : 5;
				uint64_t m_b2 : 5;
				uint64_t m_g2 : 5;
				uint64_t m_r2 : 5;
#else
				uint64_t m_b0 : 5;
				uint64_t m_g0 : 5;
				uint64_t m_r0 : 5;
				uint64_t m_b1 : 5;
				uint64_t m_g1 : 5;
				uint64_t m_r1 : 5;
				uint64_t m_b2 : 5;
				uint64_t m_g2 : 5;
				uint64_t m_r2 : 5;
				uint64_t m_b3 : 5;
				uint64_t m_g3 : 5;
				uint64_t m_r3 : 5;
#endif
				uint64_t m_alpha : 1;
				uint64_t m_glsb : 2;
				uint64_t m_mode : 1;
			} m_hi;
			uint64_t m_hi_bits;
		};
	};

	static uint8_t conv_dxt1_to_fxt1_sels(uint32_t sels)
	{
		static uint8_t s_conv_table[16] = { 0, 3, 1, 2, 12, 15, 13, 14, 4, 7, 5, 6, 8, 11, 9, 10 };
		return s_conv_table[sels & 15] | (s_conv_table[sels >> 4] << 4);
	}

	static void convert_etc1s_to_fxt1(void *pDst, const endpoint *pEndpoints, const selector *pSelectors, uint32_t fxt1_subblock)
	{
		fxt1_block* pBlock = static_cast<fxt1_block*>(pDst);

		// CC_MIXED is basically DXT1 with different encoding tricks.
		// So transcode ETC1S to DXT1, then transcode that to FXT1 which is easy and nearly lossless. 
		// (It's not completely lossless because FXT1 rounds in its color lerps while DXT1 doesn't, but it should be good enough.)
		dxt1_block blk;
		convert_etc1s_to_dxt1(&blk, pEndpoints, pSelectors, false);

		const uint32_t l = blk.get_low_color();
		const uint32_t h = blk.get_high_color();

		color32 color0((l >> 11) & 31, (l >> 5) & 63, l & 31, 255);
		color32 color1((h >> 11) & 31, (h >> 5) & 63, h & 31, 255);

		uint32_t g0 = color0.g & 1;
		uint32_t g1 = color1.g & 1;
		
		color0.g >>= 1;
		color1.g >>= 1;

		blk.m_selectors[0] = conv_dxt1_to_fxt1_sels(blk.m_selectors[0]);
		blk.m_selectors[1] = conv_dxt1_to_fxt1_sels(blk.m_selectors[1]);
		blk.m_selectors[2] = conv_dxt1_to_fxt1_sels(blk.m_selectors[2]);
		blk.m_selectors[3] = conv_dxt1_to_fxt1_sels(blk.m_selectors[3]);
		
		if ((blk.get_selector(0, 0) >> 1) != (g0 ^ g1))
		{
			std::swap(color0, color1);
			std::swap(g0, g1);

			blk.m_selectors[0] ^= 0xFF;
			blk.m_selectors[1] ^= 0xFF;
			blk.m_selectors[2] ^= 0xFF;
			blk.m_selectors[3] ^= 0xFF;
		}

		if (fxt1_subblock == 0)
		{
			pBlock->m_hi.m_mode = 1; 
			pBlock->m_hi.m_alpha = 0;
			pBlock->m_hi.m_glsb = g1 | (g1 << 1);
			pBlock->m_hi.m_r0 = color0.r;
			pBlock->m_hi.m_g0 = color0.g;
			pBlock->m_hi.m_b0 = color0.b;
			pBlock->m_hi.m_r1 = color1.r;
			pBlock->m_hi.m_g1 = color1.g;
			pBlock->m_hi.m_b1 = color1.b;
			pBlock->m_hi.m_r2 = color0.r;
			pBlock->m_hi.m_g2 = color0.g;
			pBlock->m_hi.m_b2 = color0.b;
			pBlock->m_hi.m_r3 = color1.r;
			pBlock->m_hi.m_g3 = color1.g;
			pBlock->m_hi.m_b3 = color1.b;
			pBlock->m_sels[0] = blk.m_selectors[0];
			pBlock->m_sels[1] = blk.m_selectors[1];
			pBlock->m_sels[2] = blk.m_selectors[2];
			pBlock->m_sels[3] = blk.m_selectors[3];

			static const uint8_t s_border_dup[4] = { 0, 85, 170, 255 };
			pBlock->m_sels[4] = s_border_dup[blk.m_selectors[0] >> 6];
			pBlock->m_sels[5] = s_border_dup[blk.m_selectors[1] >> 6];
			pBlock->m_sels[6] = s_border_dup[blk.m_selectors[2] >> 6];
			pBlock->m_sels[7] = s_border_dup[blk.m_selectors[3] >> 6];
		}
		else
		{
			pBlock->m_hi.m_glsb = (pBlock->m_hi.m_glsb & 1) | (g1 << 1);
			pBlock->m_hi.m_r2 = color0.r;
			pBlock->m_hi.m_g2 = color0.g;
			pBlock->m_hi.m_b2 = color0.b;
			pBlock->m_hi.m_r3 = color1.r;
			pBlock->m_hi.m_g3 = color1.g;
			pBlock->m_hi.m_b3 = color1.b;
			pBlock->m_sels[4] = blk.m_selectors[0];
			pBlock->m_sels[5] = blk.m_selectors[1];
			pBlock->m_sels[6] = blk.m_selectors[2];
			pBlock->m_sels[7] = blk.m_selectors[3];
		}
	}
#endif // BASISD_SUPPORT_FXT1
#if BASISD_SUPPORT_DXT5A
	static dxt_selector_range s_dxt5a_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },
	};

	const uint32_t NUM_DXT5A_SELECTOR_RANGES = sizeof(s_dxt5a_selector_ranges) / sizeof(s_dxt5a_selector_ranges[0]);

	struct etc1_g_to_dxt5a_conversion
	{
		uint8_t m_lo, m_hi;
		uint16_t m_trans;
	};

	static etc1_g_to_dxt5a_conversion g_etc1_g_to_dxt5a[32 * 8][NUM_DXT5A_SELECTOR_RANGES] =
	{
		{ { 8, 0, 393 },{ 8, 0, 392 },{ 2, 0, 9 },{ 2, 0, 8 }, }, { { 6, 16, 710 },{ 16, 6, 328 },{ 0, 10, 96 },{ 10, 6, 8 }, },
		{ { 28, 5, 1327 },{ 24, 14, 328 },{ 8, 18, 96 },{ 18, 14, 8 }, }, { { 36, 13, 1327 },{ 32, 22, 328 },{ 16, 26, 96 },{ 26, 22, 8 }, },
		{ { 45, 22, 1327 },{ 41, 31, 328 },{ 25, 35, 96 },{ 35, 31, 8 }, }, { { 53, 30, 1327 },{ 49, 39, 328 },{ 33, 43, 96 },{ 43, 39, 8 }, },
		{ { 61, 38, 1327 },{ 57, 47, 328 },{ 41, 51, 96 },{ 51, 47, 8 }, }, { { 69, 46, 1327 },{ 65, 55, 328 },{ 49, 59, 96 },{ 59, 55, 8 }, },
		{ { 78, 55, 1327 },{ 74, 64, 328 },{ 58, 68, 96 },{ 68, 64, 8 }, }, { { 86, 63, 1327 },{ 82, 72, 328 },{ 66, 76, 96 },{ 76, 72, 8 }, },
		{ { 94, 71, 1327 },{ 90, 80, 328 },{ 74, 84, 96 },{ 84, 80, 8 }, }, { { 102, 79, 1327 },{ 98, 88, 328 },{ 82, 92, 96 },{ 92, 88, 8 }, },
		{ { 111, 88, 1327 },{ 107, 97, 328 },{ 91, 101, 96 },{ 101, 97, 8 }, }, { { 119, 96, 1327 },{ 115, 105, 328 },{ 99, 109, 96 },{ 109, 105, 8 }, },
		{ { 127, 104, 1327 },{ 123, 113, 328 },{ 107, 117, 96 },{ 117, 113, 8 }, }, { { 135, 112, 1327 },{ 131, 121, 328 },{ 115, 125, 96 },{ 125, 121, 8 }, },
		{ { 144, 121, 1327 },{ 140, 130, 328 },{ 124, 134, 96 },{ 134, 130, 8 }, }, { { 152, 129, 1327 },{ 148, 138, 328 },{ 132, 142, 96 },{ 142, 138, 8 }, },
		{ { 160, 137, 1327 },{ 156, 146, 328 },{ 140, 150, 96 },{ 150, 146, 8 }, }, { { 168, 145, 1327 },{ 164, 154, 328 },{ 148, 158, 96 },{ 158, 154, 8 }, },
		{ { 177, 154, 1327 },{ 173, 163, 328 },{ 157, 167, 96 },{ 167, 163, 8 }, }, { { 185, 162, 1327 },{ 181, 171, 328 },{ 165, 175, 96 },{ 175, 171, 8 }, },
		{ { 193, 170, 1327 },{ 189, 179, 328 },{ 173, 183, 96 },{ 183, 179, 8 }, }, { { 201, 178, 1327 },{ 197, 187, 328 },{ 181, 191, 96 },{ 191, 187, 8 }, },
		{ { 210, 187, 1327 },{ 206, 196, 328 },{ 190, 200, 96 },{ 200, 196, 8 }, }, { { 218, 195, 1327 },{ 214, 204, 328 },{ 198, 208, 96 },{ 208, 204, 8 }, },
		{ { 226, 203, 1327 },{ 222, 212, 328 },{ 206, 216, 96 },{ 216, 212, 8 }, }, { { 234, 211, 1327 },{ 230, 220, 328 },{ 214, 224, 96 },{ 224, 220, 8 }, },
		{ { 243, 220, 1327 },{ 239, 229, 328 },{ 223, 233, 96 },{ 233, 229, 8 }, }, { { 251, 228, 1327 },{ 247, 237, 328 },{ 231, 241, 96 },{ 241, 237, 8 }, },
		{ { 239, 249, 3680 },{ 245, 249, 3648 },{ 239, 249, 96 },{ 249, 245, 8 }, }, { { 247, 253, 4040 },{ 255, 253, 8 },{ 247, 253, 456 },{ 255, 253, 8 }, },
		{ { 5, 17, 566 },{ 5, 17, 560 },{ 5, 0, 9 },{ 5, 0, 8 }, }, { { 25, 0, 313 },{ 25, 3, 328 },{ 13, 0, 49 },{ 13, 3, 8 }, },
		{ { 39, 0, 1329 },{ 33, 11, 328 },{ 11, 21, 70 },{ 21, 11, 8 }, }, { { 47, 7, 1329 },{ 41, 19, 328 },{ 29, 7, 33 },{ 29, 19, 8 }, },
		{ { 50, 11, 239 },{ 50, 28, 328 },{ 38, 16, 33 },{ 38, 28, 8 }, }, { { 92, 13, 2423 },{ 58, 36, 328 },{ 46, 24, 33 },{ 46, 36, 8 }, },
		{ { 100, 21, 2423 },{ 66, 44, 328 },{ 54, 32, 33 },{ 54, 44, 8 }, }, { { 86, 7, 1253 },{ 74, 52, 328 },{ 62, 40, 33 },{ 62, 52, 8 }, },
		{ { 95, 16, 1253 },{ 83, 61, 328 },{ 71, 49, 33 },{ 71, 61, 8 }, }, { { 103, 24, 1253 },{ 91, 69, 328 },{ 79, 57, 33 },{ 79, 69, 8 }, },
		{ { 111, 32, 1253 },{ 99, 77, 328 },{ 87, 65, 33 },{ 87, 77, 8 }, }, { { 119, 40, 1253 },{ 107, 85, 328 },{ 95, 73, 33 },{ 95, 85, 8 }, },
		{ { 128, 49, 1253 },{ 116, 94, 328 },{ 104, 82, 33 },{ 104, 94, 8 }, }, { { 136, 57, 1253 },{ 124, 102, 328 },{ 112, 90, 33 },{ 112, 102, 8 }, },
		{ { 144, 65, 1253 },{ 132, 110, 328 },{ 120, 98, 33 },{ 120, 110, 8 }, }, { { 152, 73, 1253 },{ 140, 118, 328 },{ 128, 106, 33 },{ 128, 118, 8 }, },
		{ { 161, 82, 1253 },{ 149, 127, 328 },{ 137, 115, 33 },{ 137, 127, 8 }, }, { { 169, 90, 1253 },{ 157, 135, 328 },{ 145, 123, 33 },{ 145, 135, 8 }, },
		{ { 177, 98, 1253 },{ 165, 143, 328 },{ 153, 131, 33 },{ 153, 143, 8 }, }, { { 185, 106, 1253 },{ 173, 151, 328 },{ 161, 139, 33 },{ 161, 151, 8 }, },
		{ { 194, 115, 1253 },{ 182, 160, 328 },{ 170, 148, 33 },{ 170, 160, 8 }, }, { { 202, 123, 1253 },{ 190, 168, 328 },{ 178, 156, 33 },{ 178, 168, 8 }, },
		{ { 210, 131, 1253 },{ 198, 176, 328 },{ 186, 164, 33 },{ 186, 176, 8 }, }, { { 218, 139, 1253 },{ 206, 184, 328 },{ 194, 172, 33 },{ 194, 184, 8 }, },
		{ { 227, 148, 1253 },{ 215, 193, 328 },{ 203, 181, 33 },{ 203, 193, 8 }, }, { { 235, 156, 1253 },{ 223, 201, 328 },{ 211, 189, 33 },{ 211, 201, 8 }, },
		{ { 243, 164, 1253 },{ 231, 209, 328 },{ 219, 197, 33 },{ 219, 209, 8 }, }, { { 183, 239, 867 },{ 239, 217, 328 },{ 227, 205, 33 },{ 227, 217, 8 }, },
		{ { 254, 214, 1329 },{ 248, 226, 328 },{ 236, 214, 33 },{ 236, 226, 8 }, }, { { 222, 244, 3680 },{ 234, 244, 3648 },{ 244, 222, 33 },{ 244, 234, 8 }, },
		{ { 230, 252, 3680 },{ 242, 252, 3648 },{ 252, 230, 33 },{ 252, 242, 8 }, }, { { 238, 250, 4040 },{ 255, 250, 8 },{ 238, 250, 456 },{ 255, 250, 8 }, },
		{ { 9, 29, 566 },{ 9, 29, 560 },{ 9, 0, 9 },{ 9, 0, 8 }, }, { { 17, 37, 566 },{ 17, 37, 560 },{ 17, 0, 9 },{ 17, 0, 8 }, },
		{ { 45, 0, 313 },{ 45, 0, 312 },{ 25, 0, 49 },{ 25, 7, 8 }, }, { { 14, 63, 2758 },{ 5, 53, 784 },{ 15, 33, 70 },{ 33, 15, 8 }, },
		{ { 71, 6, 1329 },{ 72, 4, 1328 },{ 42, 4, 33 },{ 42, 24, 8 }, }, { { 70, 3, 239 },{ 70, 2, 232 },{ 50, 12, 33 },{ 50, 32, 8 }, },
		{ { 0, 98, 2842 },{ 78, 10, 232 },{ 58, 20, 33 },{ 58, 40, 8 }, }, { { 97, 27, 1329 },{ 86, 18, 232 },{ 66, 28, 33 },{ 66, 48, 8 }, },
		{ { 0, 94, 867 },{ 95, 27, 232 },{ 75, 37, 33 },{ 75, 57, 8 }, }, { { 8, 102, 867 },{ 103, 35, 232 },{ 83, 45, 33 },{ 83, 65, 8 }, },
		{ { 12, 112, 867 },{ 111, 43, 232 },{ 91, 53, 33 },{ 91, 73, 8 }, }, { { 139, 2, 1253 },{ 119, 51, 232 },{ 99, 61, 33 },{ 99, 81, 8 }, },
		{ { 148, 13, 1253 },{ 128, 60, 232 },{ 108, 70, 33 },{ 108, 90, 8 }, }, { { 156, 21, 1253 },{ 136, 68, 232 },{ 116, 78, 33 },{ 116, 98, 8 }, },
		{ { 164, 29, 1253 },{ 144, 76, 232 },{ 124, 86, 33 },{ 124, 106, 8 }, }, { { 172, 37, 1253 },{ 152, 84, 232 },{ 132, 94, 33 },{ 132, 114, 8 }, },
		{ { 181, 46, 1253 },{ 161, 93, 232 },{ 141, 103, 33 },{ 141, 123, 8 }, }, { { 189, 54, 1253 },{ 169, 101, 232 },{ 149, 111, 33 },{ 149, 131, 8 }, },
		{ { 197, 62, 1253 },{ 177, 109, 232 },{ 157, 119, 33 },{ 157, 139, 8 }, }, { { 205, 70, 1253 },{ 185, 117, 232 },{ 165, 127, 33 },{ 165, 147, 8 }, },
		{ { 214, 79, 1253 },{ 194, 126, 232 },{ 174, 136, 33 },{ 174, 156, 8 }, }, { { 222, 87, 1253 },{ 202, 134, 232 },{ 182, 144, 33 },{ 182, 164, 8 }, },
		{ { 230, 95, 1253 },{ 210, 142, 232 },{ 190, 152, 33 },{ 190, 172, 8 }, }, { { 238, 103, 1253 },{ 218, 150, 232 },{ 198, 160, 33 },{ 198, 180, 8 }, },
		{ { 247, 112, 1253 },{ 227, 159, 232 },{ 207, 169, 33 },{ 207, 189, 8 }, }, { { 255, 120, 1253 },{ 235, 167, 232 },{ 215, 177, 33 },{ 215, 197, 8 }, },
		{ { 146, 243, 867 },{ 243, 175, 232 },{ 223, 185, 33 },{ 223, 205, 8 }, }, { { 184, 231, 3682 },{ 203, 251, 784 },{ 231, 193, 33 },{ 231, 213, 8 }, },
		{ { 193, 240, 3682 },{ 222, 240, 3648 },{ 240, 202, 33 },{ 240, 222, 8 }, }, { { 255, 210, 169 },{ 230, 248, 3648 },{ 248, 210, 33 },{ 248, 230, 8 }, },
		{ { 218, 238, 4040 },{ 255, 238, 8 },{ 218, 238, 456 },{ 255, 238, 8 }, }, { { 226, 246, 4040 },{ 255, 246, 8 },{ 226, 246, 456 },{ 255, 246, 8 }, },
		{ { 13, 42, 566 },{ 13, 42, 560 },{ 13, 0, 9 },{ 13, 0, 8 }, }, { { 50, 0, 329 },{ 50, 0, 328 },{ 21, 0, 9 },{ 21, 0, 8 }, },
		{ { 29, 58, 566 },{ 67, 2, 1352 },{ 3, 29, 70 },{ 29, 3, 8 }, }, { { 10, 79, 2758 },{ 76, 11, 1352 },{ 11, 37, 70 },{ 37, 11, 8 }, },
		{ { 7, 75, 790 },{ 7, 75, 784 },{ 20, 46, 70 },{ 46, 20, 8 }, }, { { 15, 83, 790 },{ 97, 1, 1328 },{ 28, 54, 70 },{ 54, 28, 8 }, },
		{ { 101, 7, 1329 },{ 105, 9, 1328 },{ 62, 0, 39 },{ 62, 36, 8 }, }, { { 99, 1, 239 },{ 99, 3, 232 },{ 1, 71, 98 },{ 70, 44, 8 }, },
		{ { 107, 11, 239 },{ 108, 12, 232 },{ 10, 80, 98 },{ 79, 53, 8 }, }, { { 115, 19, 239 },{ 116, 20, 232 },{ 18, 88, 98 },{ 87, 61, 8 }, },
		{ { 123, 27, 239 },{ 124, 28, 232 },{ 26, 96, 98 },{ 95, 69, 8 }, }, { { 131, 35, 239 },{ 132, 36, 232 },{ 34, 104, 98 },{ 103, 77, 8 }, },
		{ { 140, 44, 239 },{ 141, 45, 232 },{ 43, 113, 98 },{ 112, 86, 8 }, }, { { 148, 52, 239 },{ 149, 53, 232 },{ 51, 121, 98 },{ 120, 94, 8 }, },
		{ { 156, 60, 239 },{ 157, 61, 232 },{ 59, 129, 98 },{ 128, 102, 8 }, }, { { 164, 68, 239 },{ 165, 69, 232 },{ 67, 137, 98 },{ 136, 110, 8 }, },
		{ { 173, 77, 239 },{ 174, 78, 232 },{ 76, 146, 98 },{ 145, 119, 8 }, }, { { 181, 85, 239 },{ 182, 86, 232 },{ 84, 154, 98 },{ 153, 127, 8 }, },
		{ { 189, 93, 239 },{ 190, 94, 232 },{ 92, 162, 98 },{ 161, 135, 8 }, }, { { 197, 101, 239 },{ 198, 102, 232 },{ 100, 170, 98 },{ 169, 143, 8 }, },
		{ { 206, 110, 239 },{ 207, 111, 232 },{ 109, 179, 98 },{ 178, 152, 8 }, }, { { 214, 118, 239 },{ 215, 119, 232 },{ 117, 187, 98 },{ 186, 160, 8 }, },
		{ { 222, 126, 239 },{ 223, 127, 232 },{ 125, 195, 98 },{ 194, 168, 8 }, }, { { 230, 134, 239 },{ 231, 135, 232 },{ 133, 203, 98 },{ 202, 176, 8 }, },
		{ { 239, 143, 239 },{ 240, 144, 232 },{ 142, 212, 98 },{ 211, 185, 8 }, }, { { 247, 151, 239 },{ 180, 248, 784 },{ 150, 220, 98 },{ 219, 193, 8 }, },
		{ { 159, 228, 3682 },{ 201, 227, 3648 },{ 158, 228, 98 },{ 227, 201, 8 }, }, { { 181, 249, 3928 },{ 209, 235, 3648 },{ 166, 236, 98 },{ 235, 209, 8 }, },
		{ { 255, 189, 169 },{ 218, 244, 3648 },{ 175, 245, 98 },{ 244, 218, 8 }, }, { { 197, 226, 4040 },{ 226, 252, 3648 },{ 183, 253, 98 },{ 252, 226, 8 }, },
		{ { 205, 234, 4040 },{ 255, 234, 8 },{ 205, 234, 456 },{ 255, 234, 8 }, }, { { 213, 242, 4040 },{ 255, 242, 8 },{ 213, 242, 456 },{ 255, 242, 8 }, },
		{ { 18, 60, 566 },{ 18, 60, 560 },{ 18, 0, 9 },{ 18, 0, 8 }, }, { { 26, 68, 566 },{ 26, 68, 560 },{ 26, 0, 9 },{ 26, 0, 8 }, },
		{ { 34, 76, 566 },{ 34, 76, 560 },{ 34, 0, 9 },{ 34, 0, 8 }, }, { { 5, 104, 2758 },{ 98, 5, 1352 },{ 42, 0, 57 },{ 42, 6, 8 }, },
		{ { 92, 0, 313 },{ 93, 1, 312 },{ 15, 51, 70 },{ 51, 15, 8 }, }, { { 3, 101, 790 },{ 3, 101, 784 },{ 0, 59, 88 },{ 59, 23, 8 }, },
		{ { 14, 107, 790 },{ 11, 109, 784 },{ 31, 67, 70 },{ 67, 31, 8 }, }, { { 19, 117, 790 },{ 19, 117, 784 },{ 39, 75, 70 },{ 75, 39, 8 }, },
		{ { 28, 126, 790 },{ 28, 126, 784 },{ 83, 5, 33 },{ 84, 48, 8 }, }, { { 132, 0, 239 },{ 36, 134, 784 },{ 91, 13, 33 },{ 92, 56, 8 }, },
		{ { 142, 4, 239 },{ 44, 142, 784 },{ 99, 21, 33 },{ 100, 64, 8 }, }, { { 150, 12, 239 },{ 52, 150, 784 },{ 107, 29, 33 },{ 108, 72, 8 }, },
		{ { 159, 21, 239 },{ 61, 159, 784 },{ 116, 38, 33 },{ 117, 81, 8 }, }, { { 167, 29, 239 },{ 69, 167, 784 },{ 124, 46, 33 },{ 125, 89, 8 }, },
		{ { 175, 37, 239 },{ 77, 175, 784 },{ 132, 54, 33 },{ 133, 97, 8 }, }, { { 183, 45, 239 },{ 85, 183, 784 },{ 140, 62, 33 },{ 141, 105, 8 }, },
		{ { 192, 54, 239 },{ 94, 192, 784 },{ 149, 71, 33 },{ 150, 114, 8 }, }, { { 200, 62, 239 },{ 102, 200, 784 },{ 157, 79, 33 },{ 158, 122, 8 }, },
		{ { 208, 70, 239 },{ 110, 208, 784 },{ 165, 87, 33 },{ 166, 130, 8 }, }, { { 216, 78, 239 },{ 118, 216, 784 },{ 173, 95, 33 },{ 174, 138, 8 }, },
		{ { 225, 87, 239 },{ 127, 225, 784 },{ 182, 104, 33 },{ 183, 147, 8 }, }, { { 233, 95, 239 },{ 135, 233, 784 },{ 190, 112, 33 },{ 191, 155, 8 }, },
		{ { 241, 103, 239 },{ 143, 241, 784 },{ 198, 120, 33 },{ 199, 163, 8 }, }, { { 111, 208, 3682 },{ 151, 249, 784 },{ 206, 128, 33 },{ 207, 171, 8 }, },
		{ { 120, 217, 3682 },{ 180, 216, 3648 },{ 215, 137, 33 },{ 216, 180, 8 }, }, { { 128, 225, 3682 },{ 188, 224, 3648 },{ 223, 145, 33 },{ 224, 188, 8 }, },
		{ { 155, 253, 3928 },{ 196, 232, 3648 },{ 231, 153, 33 },{ 232, 196, 8 }, }, { { 144, 241, 3682 },{ 204, 240, 3648 },{ 239, 161, 33 },{ 240, 204, 8 }, },
		{ { 153, 250, 3682 },{ 213, 249, 3648 },{ 248, 170, 33 },{ 249, 213, 8 }, }, { { 179, 221, 4040 },{ 255, 221, 8 },{ 179, 221, 456 },{ 255, 221, 8 }, },
		{ { 187, 229, 4040 },{ 255, 229, 8 },{ 187, 229, 456 },{ 255, 229, 8 }, }, { { 195, 237, 4040 },{ 255, 237, 8 },{ 195, 237, 456 },{ 255, 237, 8 }, },
		{ { 24, 80, 566 },{ 24, 80, 560 },{ 24, 0, 9 },{ 24, 0, 8 }, }, { { 32, 88, 566 },{ 32, 88, 560 },{ 32, 0, 9 },{ 32, 0, 8 }, },
		{ { 40, 96, 566 },{ 40, 96, 560 },{ 40, 0, 9 },{ 40, 0, 8 }, }, { { 48, 104, 566 },{ 48, 104, 560 },{ 48, 0, 9 },{ 48, 0, 8 }, },
		{ { 9, 138, 2758 },{ 130, 7, 1352 },{ 9, 57, 70 },{ 57, 9, 8 }, }, { { 119, 0, 313 },{ 120, 0, 312 },{ 17, 65, 70 },{ 65, 17, 8 }, },
		{ { 0, 128, 784 },{ 128, 6, 312 },{ 25, 73, 70 },{ 73, 25, 8 }, }, { { 6, 137, 790 },{ 5, 136, 784 },{ 33, 81, 70 },{ 81, 33, 8 }, },
		{ { 42, 171, 2758 },{ 14, 145, 784 },{ 42, 90, 70 },{ 90, 42, 8 }, }, { { 50, 179, 2758 },{ 22, 153, 784 },{ 50, 98, 70 },{ 98, 50, 8 }, },
		{ { 58, 187, 2758 },{ 30, 161, 784 },{ 58, 106, 70 },{ 106, 58, 8 }, }, { { 191, 18, 1329 },{ 38, 169, 784 },{ 112, 9, 33 },{ 114, 66, 8 }, },
		{ { 176, 0, 239 },{ 47, 178, 784 },{ 121, 18, 33 },{ 123, 75, 8 }, }, { { 187, 1, 239 },{ 55, 186, 784 },{ 129, 26, 33 },{ 131, 83, 8 }, },
		{ { 195, 10, 239 },{ 63, 194, 784 },{ 137, 34, 33 },{ 139, 91, 8 }, }, { { 203, 18, 239 },{ 71, 202, 784 },{ 145, 42, 33 },{ 147, 99, 8 }, },
		{ { 212, 27, 239 },{ 80, 211, 784 },{ 154, 51, 33 },{ 156, 108, 8 }, }, { { 220, 35, 239 },{ 88, 219, 784 },{ 162, 59, 33 },{ 164, 116, 8 }, },
		{ { 228, 43, 239 },{ 96, 227, 784 },{ 170, 67, 33 },{ 172, 124, 8 }, }, { { 236, 51, 239 },{ 104, 235, 784 },{ 178, 75, 33 },{ 180, 132, 8 }, },
		{ { 245, 60, 239 },{ 113, 244, 784 },{ 187, 84, 33 },{ 189, 141, 8 }, }, { { 91, 194, 3680 },{ 149, 197, 3648 },{ 195, 92, 33 },{ 197, 149, 8 }, },
		{ { 99, 202, 3680 },{ 157, 205, 3648 },{ 203, 100, 33 },{ 205, 157, 8 }, }, { { 107, 210, 3680 },{ 165, 213, 3648 },{ 211, 108, 33 },{ 213, 165, 8 }, },
		{ { 119, 249, 3928 },{ 174, 222, 3648 },{ 220, 117, 33 },{ 222, 174, 8 }, }, { { 127, 255, 856 },{ 182, 230, 3648 },{ 228, 125, 33 },{ 230, 182, 8 }, },
		{ { 255, 135, 169 },{ 190, 238, 3648 },{ 236, 133, 33 },{ 238, 190, 8 }, }, { { 140, 243, 3680 },{ 198, 246, 3648 },{ 244, 141, 33 },{ 246, 198, 8 }, },
		{ { 151, 207, 4040 },{ 255, 207, 8 },{ 151, 207, 456 },{ 255, 207, 8 }, }, { { 159, 215, 4040 },{ 255, 215, 8 },{ 159, 215, 456 },{ 255, 215, 8 }, },
		{ { 167, 223, 4040 },{ 255, 223, 8 },{ 167, 223, 456 },{ 255, 223, 8 }, }, { { 175, 231, 4040 },{ 255, 231, 8 },{ 175, 231, 456 },{ 255, 231, 8 }, },
		{ { 33, 106, 566 },{ 33, 106, 560 },{ 33, 0, 9 },{ 33, 0, 8 }, }, { { 41, 114, 566 },{ 41, 114, 560 },{ 41, 0, 9 },{ 41, 0, 8 }, },
		{ { 49, 122, 566 },{ 49, 122, 560 },{ 49, 0, 9 },{ 49, 0, 8 }, }, { { 57, 130, 566 },{ 57, 130, 560 },{ 57, 0, 9 },{ 57, 0, 8 }, },
		{ { 66, 139, 566 },{ 66, 139, 560 },{ 66, 0, 9 },{ 66, 0, 8 }, }, { { 74, 147, 566 },{ 170, 7, 1352 },{ 8, 74, 70 },{ 74, 8, 8 }, },
		{ { 152, 0, 313 },{ 178, 15, 1352 },{ 0, 82, 80 },{ 82, 16, 8 }, }, { { 162, 0, 313 },{ 186, 23, 1352 },{ 24, 90, 70 },{ 90, 24, 8 }, },
		{ { 0, 171, 784 },{ 195, 32, 1352 },{ 33, 99, 70 },{ 99, 33, 8 }, }, { { 6, 179, 790 },{ 203, 40, 1352 },{ 41, 107, 70 },{ 107, 41, 8 }, },
		{ { 15, 187, 790 },{ 211, 48, 1352 },{ 115, 0, 41 },{ 115, 49, 8 }, }, { { 61, 199, 710 },{ 219, 56, 1352 },{ 57, 123, 70 },{ 123, 57, 8 }, },
		{ { 70, 208, 710 },{ 228, 65, 1352 },{ 66, 132, 70 },{ 132, 66, 8 }, }, { { 78, 216, 710 },{ 236, 73, 1352 },{ 74, 140, 70 },{ 140, 74, 8 }, },
		{ { 86, 224, 710 },{ 244, 81, 1352 },{ 145, 7, 33 },{ 148, 82, 8 }, }, { { 222, 8, 233 },{ 252, 89, 1352 },{ 153, 15, 33 },{ 156, 90, 8 }, },
		{ { 235, 0, 239 },{ 241, 101, 328 },{ 166, 6, 39 },{ 165, 99, 8 }, }, { { 32, 170, 3680 },{ 249, 109, 328 },{ 0, 175, 98 },{ 173, 107, 8 }, },
		{ { 40, 178, 3680 },{ 115, 181, 3648 },{ 8, 183, 98 },{ 181, 115, 8 }, }, { { 48, 186, 3680 },{ 123, 189, 3648 },{ 16, 191, 98 },{ 189, 123, 8 }, },
		{ { 57, 195, 3680 },{ 132, 198, 3648 },{ 25, 200, 98 },{ 198, 132, 8 }, }, { { 67, 243, 3928 },{ 140, 206, 3648 },{ 33, 208, 98 },{ 206, 140, 8 }, },
		{ { 76, 251, 3928 },{ 148, 214, 3648 },{ 41, 216, 98 },{ 214, 148, 8 }, }, { { 86, 255, 856 },{ 156, 222, 3648 },{ 49, 224, 98 },{ 222, 156, 8 }, },
		{ { 255, 93, 169 },{ 165, 231, 3648 },{ 58, 233, 98 },{ 231, 165, 8 }, }, { { 98, 236, 3680 },{ 173, 239, 3648 },{ 66, 241, 98 },{ 239, 173, 8 }, },
		{ { 108, 181, 4040 },{ 181, 247, 3648 },{ 74, 249, 98 },{ 247, 181, 8 }, }, { { 116, 189, 4040 },{ 255, 189, 8 },{ 116, 189, 456 },{ 255, 189, 8 }, },
		{ { 125, 198, 4040 },{ 255, 198, 8 },{ 125, 198, 456 },{ 255, 198, 8 }, }, { { 133, 206, 4040 },{ 255, 206, 8 },{ 133, 206, 456 },{ 255, 206, 8 }, },
		{ { 141, 214, 4040 },{ 255, 214, 8 },{ 141, 214, 456 },{ 255, 214, 8 }, }, { { 149, 222, 4040 },{ 255, 222, 8 },{ 149, 222, 456 },{ 255, 222, 8 }, },
		{ { 47, 183, 566 },{ 47, 183, 560 },{ 47, 0, 9 },{ 47, 0, 8 }, }, { { 55, 191, 566 },{ 55, 191, 560 },{ 55, 0, 9 },{ 55, 0, 8 }, },
		{ { 63, 199, 566 },{ 63, 199, 560 },{ 63, 0, 9 },{ 63, 0, 8 }, }, { { 71, 207, 566 },{ 71, 207, 560 },{ 71, 0, 9 },{ 71, 0, 8 }, },
		{ { 80, 216, 566 },{ 80, 216, 560 },{ 80, 0, 9 },{ 80, 0, 8 }, }, { { 88, 224, 566 },{ 88, 224, 560 },{ 88, 0, 9 },{ 88, 0, 8 }, },
		{ { 3, 233, 710 },{ 3, 233, 704 },{ 2, 96, 70 },{ 96, 2, 8 }, }, { { 11, 241, 710 },{ 11, 241, 704 },{ 10, 104, 70 },{ 104, 10, 8 }, },
		{ { 20, 250, 710 },{ 20, 250, 704 },{ 19, 113, 70 },{ 113, 19, 8 }, }, { { 27, 121, 3654 },{ 27, 121, 3648 },{ 27, 121, 70 },{ 121, 27, 8 }, },
		{ { 35, 129, 3654 },{ 35, 129, 3648 },{ 35, 129, 70 },{ 129, 35, 8 }, }, { { 43, 137, 3654 },{ 43, 137, 3648 },{ 43, 137, 70 },{ 137, 43, 8 }, },
		{ { 52, 146, 3654 },{ 52, 146, 3648 },{ 52, 146, 70 },{ 146, 52, 8 }, }, { { 60, 154, 3654 },{ 60, 154, 3648 },{ 60, 154, 70 },{ 154, 60, 8 }, },
		{ { 68, 162, 3654 },{ 68, 162, 3648 },{ 68, 162, 70 },{ 162, 68, 8 }, }, { { 76, 170, 3654 },{ 76, 170, 3648 },{ 76, 170, 70 },{ 170, 76, 8 }, },
		{ { 85, 179, 3654 },{ 85, 179, 3648 },{ 85, 179, 70 },{ 179, 85, 8 }, }, { { 93, 187, 3654 },{ 93, 187, 3648 },{ 93, 187, 70 },{ 187, 93, 8 }, },
		{ { 101, 195, 3654 },{ 101, 195, 3648 },{ 101, 195, 70 },{ 195, 101, 8 }, }, { { 109, 203, 3654 },{ 109, 203, 3648 },{ 109, 203, 70 },{ 203, 109, 8 }, },
		{ { 118, 212, 3654 },{ 118, 212, 3648 },{ 118, 212, 70 },{ 212, 118, 8 }, }, { { 126, 220, 3654 },{ 126, 220, 3648 },{ 126, 220, 70 },{ 220, 126, 8 }, },
		{ { 134, 228, 3654 },{ 134, 228, 3648 },{ 134, 228, 70 },{ 228, 134, 8 }, }, { { 5, 236, 3680 },{ 142, 236, 3648 },{ 5, 236, 96 },{ 236, 142, 8 }, },
		{ { 14, 245, 3680 },{ 151, 245, 3648 },{ 14, 245, 96 },{ 245, 151, 8 }, }, { { 23, 159, 4040 },{ 159, 253, 3648 },{ 23, 159, 456 },{ 253, 159, 8 }, },
		{ { 31, 167, 4040 },{ 255, 167, 8 },{ 31, 167, 456 },{ 255, 167, 8 }, }, { { 39, 175, 4040 },{ 255, 175, 8 },{ 39, 175, 456 },{ 255, 175, 8 }, },
		{ { 48, 184, 4040 },{ 255, 184, 8 },{ 48, 184, 456 },{ 255, 184, 8 }, }, { { 56, 192, 4040 },{ 255, 192, 8 },{ 56, 192, 456 },{ 255, 192, 8 }, },
		{ { 64, 200, 4040 },{ 255, 200, 8 },{ 64, 200, 456 },{ 255, 200, 8 }, },{ { 72, 208, 4040 },{ 255, 208, 8 },{ 72, 208, 456 },{ 255, 208, 8 }, },

	};

	struct dxt5a_block
	{
		uint8_t m_endpoints[2];

		enum { cTotalSelectorBytes = 6 };
		uint8_t m_selectors[cTotalSelectorBytes];

		inline void clear()
		{
			basisu::clear_obj(*this);
		}

		inline uint32_t get_low_alpha() const
		{
			return m_endpoints[0];
		}

		inline uint32_t get_high_alpha() const
		{
			return m_endpoints[1];
		}

		inline void set_low_alpha(uint32_t i)
		{
			assert(i <= UINT8_MAX);
			m_endpoints[0] = static_cast<uint8_t>(i);
		}

		inline void set_high_alpha(uint32_t i)
		{
			assert(i <= UINT8_MAX);
			m_endpoints[1] = static_cast<uint8_t>(i);
		}

		inline bool is_alpha6_block() const { return get_low_alpha() <= get_high_alpha(); }

		uint32_t get_endpoints_as_word() const { return m_endpoints[0] | (m_endpoints[1] << 8); }
		uint32_t get_selectors_as_word(uint32_t index) { assert(index < 3); return m_selectors[index * 2] | (m_selectors[index * 2 + 1] << 8); }

		inline uint32_t get_selector(uint32_t x, uint32_t y) const
		{
			assert((x < 4U) && (y < 4U));

			uint32_t selector_index = (y * 4) + x;
			uint32_t bit_index = selector_index * cDXT5SelectorBits;

			uint32_t byte_index = bit_index >> 3;
			uint32_t bit_ofs = bit_index & 7;

			uint32_t v = m_selectors[byte_index];
			if (byte_index < (cTotalSelectorBytes - 1))
				v |= (m_selectors[byte_index + 1] << 8);

			return (v >> bit_ofs) & 7;
		}

		inline void set_selector(uint32_t x, uint32_t y, uint32_t val)
		{
			assert((x < 4U) && (y < 4U) && (val < 8U));

			uint32_t selector_index = (y * 4) + x;
			uint32_t bit_index = selector_index * cDXT5SelectorBits;

			uint32_t byte_index = bit_index >> 3;
			uint32_t bit_ofs = bit_index & 7;

			uint32_t v = m_selectors[byte_index];
			if (byte_index < (cTotalSelectorBytes - 1))
				v |= (m_selectors[byte_index + 1] << 8);

			v &= (~(7 << bit_ofs));
			v |= (val << bit_ofs);

			m_selectors[byte_index] = static_cast<uint8_t>(v);
			if (byte_index < (cTotalSelectorBytes - 1))
				m_selectors[byte_index + 1] = static_cast<uint8_t>(v >> 8);
		}

		enum { cMaxSelectorValues = 8 };

		static uint32_t get_block_values6(color32* pDst, uint32_t l, uint32_t h)
		{
			pDst[0].a = static_cast<uint8_t>(l);
			pDst[1].a = static_cast<uint8_t>(h);
			pDst[2].a = static_cast<uint8_t>((l * 4 + h) / 5);
			pDst[3].a = static_cast<uint8_t>((l * 3 + h * 2) / 5);
			pDst[4].a = static_cast<uint8_t>((l * 2 + h * 3) / 5);
			pDst[5].a = static_cast<uint8_t>((l + h * 4) / 5);
			pDst[6].a = 0;
			pDst[7].a = 255;
			return 6;
		}

		static uint32_t get_block_values8(color32* pDst, uint32_t l, uint32_t h)
		{
			pDst[0].a = static_cast<uint8_t>(l);
			pDst[1].a = static_cast<uint8_t>(h);
			pDst[2].a = static_cast<uint8_t>((l * 6 + h) / 7);
			pDst[3].a = static_cast<uint8_t>((l * 5 + h * 2) / 7);
			pDst[4].a = static_cast<uint8_t>((l * 4 + h * 3) / 7);
			pDst[5].a = static_cast<uint8_t>((l * 3 + h * 4) / 7);
			pDst[6].a = static_cast<uint8_t>((l * 2 + h * 5) / 7);
			pDst[7].a = static_cast<uint8_t>((l + h * 6) / 7);
			return 8;
		}

		static uint32_t get_block_values(color32* pDst, uint32_t l, uint32_t h)
		{
			if (l > h)
				return get_block_values8(pDst, l, h);
			else
				return get_block_values6(pDst, l, h);
		}
	};

	static void convert_etc1s_to_dxt5a(dxt5a_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector)
	{
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(base_color, inten_table, low_selector, r);
						
			pDst_block->set_low_alpha(r);
			pDst_block->set_high_alpha(r);
			pDst_block->m_selectors[0] = 0;
			pDst_block->m_selectors[1] = 0;
			pDst_block->m_selectors[2] = 0;
			pDst_block->m_selectors[3] = 0;
			pDst_block->m_selectors[4] = 0;
			pDst_block->m_selectors[5] = 0;
			return;
		}
		else if (pSelector->m_num_unique_selectors == 2)
		{
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[low_selector].r;
			const uint32_t r1 = block_colors[high_selector].r;

			pDst_block->set_low_alpha(r0);
			pDst_block->set_high_alpha(r1);

			// TODO: Optimize this
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					pDst_block->set_selector(x, y, (s == high_selector) ? 1 : 0);
				}
			}

			return;
		}

		uint32_t selector_range_table = 0;
		for (selector_range_table = 0; selector_range_table < NUM_DXT5A_SELECTOR_RANGES; selector_range_table++)
			if ((low_selector == s_dxt5a_selector_ranges[selector_range_table].m_low) && (high_selector == s_dxt5a_selector_ranges[selector_range_table].m_high))
				break;
		if (selector_range_table >= NUM_DXT5A_SELECTOR_RANGES)
			selector_range_table = 0;

		const etc1_g_to_dxt5a_conversion* pTable_entry = &g_etc1_g_to_dxt5a[base_color.r + inten_table * 32][selector_range_table];

		pDst_block->set_low_alpha(pTable_entry->m_lo);
		pDst_block->set_high_alpha(pTable_entry->m_hi);

		// TODO: Optimize this (like ETC1->BC1)
		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s = pSelector->get_selector(x, y);

				uint32_t ds = (pTable_entry->m_trans >> (s * 3)) & 7;

				pDst_block->set_selector(x, y, ds);
			}
		}
	}
#endif //BASISD_SUPPORT_DXT5A

	// PVRTC

#if BASISD_SUPPORT_PVRTC1 || BASISD_SUPPORT_UASTC
	static const  uint16_t g_pvrtc_swizzle_table[256] =
	{
		0x0000, 0x0001, 0x0004, 0x0005, 0x0010, 0x0011, 0x0014, 0x0015, 0x0040, 0x0041, 0x0044, 0x0045, 0x0050, 0x0051, 0x0054, 0x0055, 0x0100, 0x0101, 0x0104, 0x0105, 0x0110, 0x0111, 0x0114, 0x0115, 0x0140, 0x0141, 0x0144, 0x0145, 0x0150, 0x0151, 0x0154, 0x0155,
		0x0400, 0x0401, 0x0404, 0x0405, 0x0410, 0x0411, 0x0414, 0x0415, 0x0440, 0x0441, 0x0444, 0x0445, 0x0450, 0x0451, 0x0454, 0x0455, 0x0500, 0x0501, 0x0504, 0x0505, 0x0510, 0x0511, 0x0514, 0x0515, 0x0540, 0x0541, 0x0544, 0x0545, 0x0550, 0x0551, 0x0554, 0x0555,
		0x1000, 0x1001, 0x1004, 0x1005, 0x1010, 0x1011, 0x1014, 0x1015, 0x1040, 0x1041, 0x1044, 0x1045, 0x1050, 0x1051, 0x1054, 0x1055, 0x1100, 0x1101, 0x1104, 0x1105, 0x1110, 0x1111, 0x1114, 0x1115, 0x1140, 0x1141, 0x1144, 0x1145, 0x1150, 0x1151, 0x1154, 0x1155,
		0x1400, 0x1401, 0x1404, 0x1405, 0x1410, 0x1411, 0x1414, 0x1415, 0x1440, 0x1441, 0x1444, 0x1445, 0x1450, 0x1451, 0x1454, 0x1455, 0x1500, 0x1501, 0x1504, 0x1505, 0x1510, 0x1511, 0x1514, 0x1515, 0x1540, 0x1541, 0x1544, 0x1545, 0x1550, 0x1551, 0x1554, 0x1555,
		0x4000, 0x4001, 0x4004, 0x4005, 0x4010, 0x4011, 0x4014, 0x4015, 0x4040, 0x4041, 0x4044, 0x4045, 0x4050, 0x4051, 0x4054, 0x4055, 0x4100, 0x4101, 0x4104, 0x4105, 0x4110, 0x4111, 0x4114, 0x4115, 0x4140, 0x4141, 0x4144, 0x4145, 0x4150, 0x4151, 0x4154, 0x4155,
		0x4400, 0x4401, 0x4404, 0x4405, 0x4410, 0x4411, 0x4414, 0x4415, 0x4440, 0x4441, 0x4444, 0x4445, 0x4450, 0x4451, 0x4454, 0x4455, 0x4500, 0x4501, 0x4504, 0x4505, 0x4510, 0x4511, 0x4514, 0x4515, 0x4540, 0x4541, 0x4544, 0x4545, 0x4550, 0x4551, 0x4554, 0x4555,
		0x5000, 0x5001, 0x5004, 0x5005, 0x5010, 0x5011, 0x5014, 0x5015, 0x5040, 0x5041, 0x5044, 0x5045, 0x5050, 0x5051, 0x5054, 0x5055, 0x5100, 0x5101, 0x5104, 0x5105, 0x5110, 0x5111, 0x5114, 0x5115, 0x5140, 0x5141, 0x5144, 0x5145, 0x5150, 0x5151, 0x5154, 0x5155,
		0x5400, 0x5401, 0x5404, 0x5405, 0x5410, 0x5411, 0x5414, 0x5415, 0x5440, 0x5441, 0x5444, 0x5445, 0x5450, 0x5451, 0x5454, 0x5455, 0x5500, 0x5501, 0x5504, 0x5505, 0x5510, 0x5511, 0x5514, 0x5515, 0x5540, 0x5541, 0x5544, 0x5545, 0x5550, 0x5551, 0x5554, 0x5555
	};

	// Note we can't use simple calculations to convert PVRTC1 encoded endpoint components to/from 8-bits, due to hardware approximations.
	static const uint8_t g_pvrtc_5[32] = { 0,8,16,24,33,41,49,57,66,74,82,90,99,107,115,123,132,140,148,156,165,173,181,189,198,206,214,222,231,239,247,255 };
	static const uint8_t g_pvrtc_4[16] = { 0,16,33,49,66,82,99,115,140,156,173,189,206,222,239,255 };
	static const uint8_t g_pvrtc_3[8] = { 0,33,74,107,148,181,222,255 };
	static const uint8_t g_pvrtc_alpha[9] = { 0,34,68,102,136,170,204,238,255 };
		
	static const uint8_t g_pvrtc_5_floor[256] =
	{
		0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,
		3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,
		7,7,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,11,11,11,11,11,11,
		11,11,11,12,12,12,12,12,12,12,12,13,13,13,13,13,13,13,13,14,14,14,14,14,14,14,14,15,15,15,15,15,
		15,15,15,15,16,16,16,16,16,16,16,16,17,17,17,17,17,17,17,17,18,18,18,18,18,18,18,18,19,19,19,19,
		19,19,19,19,19,20,20,20,20,20,20,20,20,21,21,21,21,21,21,21,21,22,22,22,22,22,22,22,22,23,23,23,
		23,23,23,23,23,23,24,24,24,24,24,24,24,24,25,25,25,25,25,25,25,25,26,26,26,26,26,26,26,26,27,27,
		27,27,27,27,27,27,27,28,28,28,28,28,28,28,28,29,29,29,29,29,29,29,29,30,30,30,30,30,30,30,30,31
	};

	static const uint8_t g_pvrtc_5_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,
		4,4,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,8,8,8,8,8,8,
		8,8,8,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11,11,12,12,12,12,12,
		12,12,12,12,13,13,13,13,13,13,13,13,14,14,14,14,14,14,14,14,15,15,15,15,15,15,15,15,16,16,16,16,
		16,16,16,16,16,17,17,17,17,17,17,17,17,18,18,18,18,18,18,18,18,19,19,19,19,19,19,19,19,20,20,20,
		20,20,20,20,20,20,21,21,21,21,21,21,21,21,22,22,22,22,22,22,22,22,23,23,23,23,23,23,23,23,24,24,
		24,24,24,24,24,24,24,25,25,25,25,25,25,25,25,26,26,26,26,26,26,26,26,27,27,27,27,27,27,27,27,28,
		28,28,28,28,28,28,28,28,29,29,29,29,29,29,29,29,30,30,30,30,30,30,30,30,31,31,31,31,31,31,31,31
	};
		
	static const uint8_t g_pvrtc_4_floor[256] =
	{
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,
		9,9,9,9,9,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,
		11,11,11,11,11,11,11,11,11,11,11,11,11,11,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,13,13,
		13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,15
	};

	static const uint8_t g_pvrtc_4_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,10,10,10,
		10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,12,12,
		12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,14,
		14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15
	};
		
	static const uint8_t g_pvrtc_3_floor[256] =
	{
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7
	};

	static const uint8_t g_pvrtc_3_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
	};
		
	static const uint8_t g_pvrtc_alpha_floor[256] =
	{
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
		0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8
	};

	static const uint8_t g_pvrtc_alpha_ceil[256] =
	{
		0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
		2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
		3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
		4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
	};

	struct pvrtc4_block
	{
		uint32_t m_modulation;
		uint32_t m_endpoints;

		pvrtc4_block() : m_modulation(0), m_endpoints(0) { }

		inline bool operator== (const pvrtc4_block& rhs) const
		{
			return (m_modulation == rhs.m_modulation) && (m_endpoints == rhs.m_endpoints);
		}

		inline void clear()
		{
			m_modulation = 0;
			m_endpoints = 0;
		}

		inline bool get_block_uses_transparent_modulation() const
		{
			return (m_endpoints & 1) != 0;
		}

		inline void set_block_uses_transparent_modulation(bool m)
		{
			m_endpoints = (m_endpoints & ~1U) | static_cast<uint32_t>(m);
		}

		inline bool is_endpoint_opaque(uint32_t endpoint_index) const
		{
			static const uint32_t s_bitmasks[2] = { 0x8000U, 0x80000000U };
			return (m_endpoints & s_bitmasks[basisu::open_range_check(endpoint_index, 2U)]) != 0;
		}

		inline void set_endpoint_opaque(uint32_t endpoint_index, bool opaque)
		{
			assert(endpoint_index < 2);
			static const uint32_t s_bitmasks[2] = { 0x8000U, 0x80000000U };
			if (opaque)
				m_endpoints |= s_bitmasks[endpoint_index];
			else
				m_endpoints &= ~s_bitmasks[endpoint_index];
		}

		inline color32 get_endpoint_5554(uint32_t endpoint_index) const
		{
			assert(endpoint_index < 2);
			static const uint32_t s_endpoint_mask[2] = { 0xFFFE, 0xFFFF };
			uint32_t packed = (m_endpoints >> (basisu::open_range_check(endpoint_index, 2U) ? 16 : 0)) & s_endpoint_mask[endpoint_index];

			uint32_t r, g, b, a;
			if (packed & 0x8000)
			{
				// opaque 554 or 555
				r = (packed >> 10) & 31;
				g = (packed >> 5) & 31;
				b = packed & 31;

				if (!endpoint_index)
					b |= (b >> 4);

				a = 0xF;
			}
			else
			{
				// translucent 4433 or 4443
				r = (packed >> 7) & 0x1E;
				g = (packed >> 3) & 0x1E;
				b = (packed & 0xF) << 1;

				r |= (r >> 4);
				g |= (g >> 4);

				if (!endpoint_index)
					b |= (b >> 3);
				else
					b |= (b >> 4);

				a = (packed >> 11) & 0xE;
			}

			assert((r < 32) && (g < 32) && (b < 32) && (a < 16));
					
			return color32(r, g, b, a);
		}
				
		inline color32 get_endpoint_8888(uint32_t endpoint_index) const
		{
			assert(endpoint_index < 2);
			static const uint32_t s_endpoint_mask[2] = { 0xFFFE, 0xFFFF };
			uint32_t packed = (m_endpoints >> (basisu::open_range_check(endpoint_index, 2U) ? 16 : 0)) & s_endpoint_mask[endpoint_index];

			uint32_t r, g, b, a;
			if (packed & 0x8000)
			{
				// opaque 554 or 555
				// 1RRRRRGGGGGBBBBM
				// 1RRRRRGGGGGBBBBB
				r = (packed >> 10) & 31;
				g = (packed >> 5) & 31;
				b = packed & 31;

				r = g_pvrtc_5[r];
				g = g_pvrtc_5[g];

				if (!endpoint_index)
					b = g_pvrtc_4[b >> 1];
				else
					b = g_pvrtc_5[b];

				a = 255;
			}
			else
			{
				// translucent 4433 or 4443
				// 0AAA RRRR GGGG BBBM
				// 0AAA RRRR GGGG BBBB
				r = (packed >> 8) & 0xF;
				g = (packed >> 4) & 0xF;
				b = packed & 0xF;
				a = (packed >> 12) & 7;

				r = g_pvrtc_4[r];
				g = g_pvrtc_4[g];

				if (!endpoint_index)
					b = g_pvrtc_3[b >> 1];
				else
					b = g_pvrtc_4[b];

				a = g_pvrtc_alpha[a];
			}
			
			return color32(r, g, b, a);
		}

		inline uint32_t get_endpoint_l8(uint32_t endpoint_index) const
		{
			color32 c(get_endpoint_8888(endpoint_index));
			return c.r + c.g + c.b + c.a;
		}
				
		inline uint32_t get_opaque_endpoint_l0() const
		{
			uint32_t packed = m_endpoints & 0xFFFE;

			uint32_t r, g, b;
			assert(packed & 0x8000);

			// opaque 554 or 555
			r = (packed >> 10) & 31;
			g = (packed >> 5) & 31;
			b = packed & 31;
			b |= (b >> 4);

			return r + g + b;
		}

		inline uint32_t get_opaque_endpoint_l1() const
		{
			uint32_t packed = m_endpoints >> 16;

			uint32_t r, g, b;
			assert(packed & 0x8000);

			// opaque 554 or 555
			r = (packed >> 10) & 31;
			g = (packed >> 5) & 31;
			b = packed & 31;

			return r + g + b;
		}

		static uint32_t get_component_precision_in_bits(uint32_t c, uint32_t endpoint_index, bool opaque_endpoint)
		{
			static const uint32_t s_comp_prec[4][4] =
			{
				// R0 G0 B0 A0      R1 G1 B1 A1
				{ 4, 4, 3, 3 },{ 4, 4, 4, 3 }, // transparent endpoint

				{ 5, 5, 4, 0 },{ 5, 5, 5, 0 }  // opaque endpoint
			};
			return s_comp_prec[basisu::open_range_check(endpoint_index, 2U) + (opaque_endpoint * 2)][basisu::open_range_check(c, 4U)];
		}

		static color32 get_color_precision_in_bits(uint32_t endpoint_index, bool opaque_endpoint)
		{
			static const color32 s_color_prec[4] =
			{
				color32(4, 4, 3, 3), color32(4, 4, 4, 3), // transparent endpoint
				color32(5, 5, 4, 0), color32(5, 5, 5, 0)  // opaque endpoint
			};
			return s_color_prec[basisu::open_range_check(endpoint_index, 2U) + (opaque_endpoint * 2)];
		}

		inline void set_opaque_endpoint_floor(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);
			const uint32_t m = m_endpoints & 1;

			uint32_t r = g_pvrtc_5_floor[c[0]], g = g_pvrtc_5_floor[c[1]], b = c[2];

			if (!endpoint_index)
				b = g_pvrtc_4_floor[b] << 1;
			else
				b = g_pvrtc_5_floor[b];

			// rgba=555 here
			assert((r < 32) && (g < 32) && (b < 32));

			// 1RRRRRGGGGGBBBBM
			// 1RRRRRGGGGGBBBBB

			// opaque 554 or 555
			uint32_t packed = 0x8000 | (r << 10) | (g << 5) | b;
			if (!endpoint_index)
				packed = (packed & ~1) | m;

			assert(packed <= 0xFFFF);

			if (endpoint_index)
				m_endpoints = (m_endpoints & 0xFFFFU) | (packed << 16);
			else
				m_endpoints = (m_endpoints & 0xFFFF0000U) | packed;
		}

		inline void set_opaque_endpoint_ceil(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);
			const uint32_t m = m_endpoints & 1;

			uint32_t r = g_pvrtc_5_ceil[c[0]], g = g_pvrtc_5_ceil[c[1]], b = c[2];

			if (!endpoint_index)
				b = g_pvrtc_4_ceil[b] << 1;
			else
				b = g_pvrtc_5_ceil[b];

			// rgba=555 here
			assert((r < 32) && (g < 32) && (b < 32));

			// 1RRRRRGGGGGBBBBM
			// 1RRRRRGGGGGBBBBB

			// opaque 554 or 555
			uint32_t packed = 0x8000 | (r << 10) | (g << 5) | b;
			if (!endpoint_index)
				packed |= m;

			assert(packed <= 0xFFFF);

			if (endpoint_index)
				m_endpoints = (m_endpoints & 0xFFFFU) | (packed << 16);
			else
				m_endpoints = (m_endpoints & 0xFFFF0000U) | packed;
		}
				
		// opaque endpoints:	554 or 555
		// transparent endpoints: 3443 or 3444
		inline void set_endpoint_raw(uint32_t endpoint_index, const color32& c, bool opaque_endpoint)
		{
			assert(endpoint_index < 2);
			const uint32_t m = m_endpoints & 1;
			uint32_t r = c[0], g = c[1], b = c[2], a = c[3];

			uint32_t packed;

			if (opaque_endpoint)
			{
				if (!endpoint_index)
				{
					// 554
					// 1RRRRRGGGGGBBBBM
					assert((r < 32) && (g < 32) && (b < 16));
					packed = 0x8000 | (r << 10) | (g << 5) | (b << 1) | m;
				}
				else
				{
					// 555
					// 1RRRRRGGGGGBBBBB
					assert((r < 32) && (g < 32) && (b < 32));
					packed = 0x8000 | (r << 10) | (g << 5) | b;
				}
			}
			else
			{
				if (!endpoint_index)
				{
					// 3443
					// 0AAA RRRR GGGG BBBM
					assert((r < 16) && (g < 16) && (b < 8) && (a < 8));
					packed = (a << 12) | (r << 8) | (g << 4) | (b << 1) | m;
				}
				else
				{
					// 3444
					// 0AAA RRRR GGGG BBBB
					assert((r < 16) && (g < 16) && (b < 16) && (a < 8));
					packed = (a << 12) | (r << 8) | (g << 4) | b;
				}
			}

			assert(packed <= 0xFFFF);

			if (endpoint_index)
				m_endpoints = (m_endpoints & 0xFFFFU) | (packed << 16);
			else
				m_endpoints = (m_endpoints & 0xFFFF0000U) | packed;
		}
				
		inline void set_endpoint_floor(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);

			int a = g_pvrtc_alpha_floor[c.a];
			if (a == 8)
			{
				// 554 or 555
				uint32_t r = g_pvrtc_5_floor[c[0]], g = g_pvrtc_5_floor[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_4_floor[b];
				else
					b = g_pvrtc_5_floor[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), true);
			}
			else
			{
				// 4433 or 4443
				uint32_t r = g_pvrtc_4_floor[c[0]], g = g_pvrtc_4_floor[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_3_floor[b];
				else
					b = g_pvrtc_4_floor[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), false);
			}
		}

		inline void set_endpoint_ceil(uint32_t endpoint_index, const color32& c)
		{
			assert(endpoint_index < 2);

			int a = g_pvrtc_alpha_ceil[c.a];
			if (a == 8)
			{
				// 554 or 555
				uint32_t r = g_pvrtc_5_ceil[c[0]], g = g_pvrtc_5_ceil[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_4_ceil[b];
				else
					b = g_pvrtc_5_ceil[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), true);
			}
			else
			{
				// 4433 or 4443
				uint32_t r = g_pvrtc_4_ceil[c[0]], g = g_pvrtc_4_ceil[c[1]], b = c[2];

				if (!endpoint_index)
					b = g_pvrtc_3_ceil[b];
				else
					b = g_pvrtc_4_ceil[b];

				set_endpoint_raw(endpoint_index, color32(r, g, b, a), false);
			}
		}

		inline uint32_t get_modulation(uint32_t x, uint32_t y) const
		{
			assert((x < 4) && (y < 4));
			return (m_modulation >> ((y * 4 + x) * 2)) & 3;
		}

		// Scaled by 8
		inline const uint32_t* get_scaled_modulation_values(bool block_uses_transparent_modulation) const
		{
			static const uint32_t s_block_scales[2][4] = { { 0, 3, 5, 8 },{ 0, 4, 4, 8 } };
			return s_block_scales[block_uses_transparent_modulation];
		}

		// Scaled by 8
		inline uint32_t get_scaled_modulation(uint32_t x, uint32_t y) const
		{
			return get_scaled_modulation_values(get_block_uses_transparent_modulation())[get_modulation(x, y)];
		}

		inline void set_modulation(uint32_t x, uint32_t y, uint32_t s)
		{
			assert((x < 4) && (y < 4) && (s < 4));
			uint32_t n = (y * 4 + x) * 2;
			m_modulation = (m_modulation & (~(3 << n))) | (s << n);
			assert(get_modulation(x, y) == s);
		}

		// Assumes modulation was initialized to 0
		inline void set_modulation_fast(uint32_t x, uint32_t y, uint32_t s)
		{
			assert((x < 4) && (y < 4) && (s < 4));
			uint32_t n = (y * 4 + x) * 2;
			m_modulation |= (s << n);
			assert(get_modulation(x, y) == s);
		}
	};

#if 0
	static const uint8_t g_pvrtc_bilinear_weights[16][4] =
	{
		{ 4, 4, 4, 4 }, { 2, 6, 2, 6 }, { 8, 0, 8, 0 }, { 6, 2, 6, 2 },
		{ 2, 2, 6, 6 }, { 1, 3, 3, 9 }, { 4, 0, 12, 0 }, { 3, 1, 9, 3 },
		{ 8, 8, 0, 0 }, { 4, 12, 0, 0 }, { 16, 0, 0, 0 }, { 12, 4, 0, 0 },
		{ 6, 6, 2, 2 }, { 3, 9, 1, 3 }, { 12, 0, 4, 0 }, { 9, 3, 3, 1 },
	};
#endif

	static inline uint32_t get_opaque_endpoint_l0(uint32_t endpoints)
	{
		uint32_t packed = endpoints;

		uint32_t r, g, b;
		assert(packed & 0x8000);

		r = (packed >> 10) & 31;
		g = (packed >> 5) & 31;
		b = packed & 30;
		b |= (b >> 4);

		return r + g + b;
	}

	static inline uint32_t get_opaque_endpoint_l1(uint32_t endpoints)
	{
		uint32_t packed = endpoints >> 16;

		uint32_t r, g, b;
		assert(packed & 0x8000);

		r = (packed >> 10) & 31;
		g = (packed >> 5) & 31;
		b = packed & 31;

		return r + g + b;
	}

	static color32 get_endpoint_8888(uint32_t endpoints, uint32_t endpoint_index)
	{
		assert(endpoint_index < 2);
		static const uint32_t s_endpoint_mask[2] = { 0xFFFE, 0xFFFF };
		uint32_t packed = (endpoints >> (basisu::open_range_check(endpoint_index, 2U) ? 16 : 0)) & s_endpoint_mask[endpoint_index];

		uint32_t r, g, b, a;
		if (packed & 0x8000)
		{
			// opaque 554 or 555
			// 1RRRRRGGGGGBBBBM
			// 1RRRRRGGGGGBBBBB
			r = (packed >> 10) & 31;
			g = (packed >> 5) & 31;
			b = packed & 31;

			r = g_pvrtc_5[r];
			g = g_pvrtc_5[g];

			if (!endpoint_index)
				b = g_pvrtc_4[b >> 1];
			else
				b = g_pvrtc_5[b];

			a = 255;
		}
		else
		{
			// translucent 4433 or 4443
			// 0AAA RRRR GGGG BBBM
			// 0AAA RRRR GGGG BBBB
			r = (packed >> 8) & 0xF;
			g = (packed >> 4) & 0xF;
			b = packed & 0xF;
			a = (packed >> 12) & 7;

			r = g_pvrtc_4[r];
			g = g_pvrtc_4[g];

			if (!endpoint_index)
				b = g_pvrtc_3[b >> 1];
			else
				b = g_pvrtc_4[b];

			a = g_pvrtc_alpha[a];
		}

		return color32(r, g, b, a);
	}

	static uint32_t get_endpoint_l8(uint32_t endpoints, uint32_t endpoint_index)
	{
		color32 c(get_endpoint_8888(endpoints, endpoint_index));
		return c.r + c.g + c.b + c.a;
	}
#endif

#if BASISD_SUPPORT_PVRTC1
	// TODO: Support decoding a non-pow2 ETC1S texture into the next larger pow2 PVRTC texture.
	static void fixup_pvrtc1_4_modulation_rgb(const decoder_etc_block* pETC_Blocks, const uint32_t* pPVRTC_endpoints, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1; 

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1; 

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31;
					e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31;
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const decoder_etc_block& src_block = pETC_Blocks[block_index];

				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				uint32_t base_r = g_etc_5_to_8[src_block.m_differential.m_red1];
				uint32_t base_g = g_etc_5_to_8[src_block.m_differential.m_green1];
				uint32_t base_b = g_etc_5_to_8[src_block.m_differential.m_blue1];

				const int* pInten_table48 = g_etc1_inten_tables48[src_block.m_differential.m_cw1];
				int by = (base_r + base_g + base_b) * 16;
				int block_colors_y_x16[4];
				block_colors_y_x16[0] = by + pInten_table48[2];
				block_colors_y_x16[1] = by + pInten_table48[3];
				block_colors_y_x16[2] = by + pInten_table48[1];
				block_colors_y_x16[3] = by + pInten_table48[0];

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31; \
						e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31; \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

				uint32_t lookup_x[4];

#define DO_LOOKUP(lx) { \
					const uint32_t byte_ofs = 7 - (((lx) * 4) >> 3); \
					const uint32_t lsb_bits = src_block.m_bytes[byte_ofs] >> (((lx) & 1) * 4); \
					const uint32_t msb_bits = src_block.m_bytes[byte_ofs - 2] >> (((lx) & 1) * 4); \
					lookup_x[lx] = (lsb_bits & 0xF) | ((msb_bits & 0xF) << 4); }

				DO_LOOKUP(0);
				DO_LOOKUP(1);
				DO_LOOKUP(2);
				DO_LOOKUP(3);
#undef DO_LOOKUP

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = block_colors_y_x16[g_etc1_x_selector_unpack[ly][lookup_x[lx]]]; \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}

	static void fixup_pvrtc1_4_modulation_rgba(
		const decoder_etc_block* pETC_Blocks, 
		const uint32_t* pPVRTC_endpoints, 
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, void *pAlpha_blocks,
		const endpoint* pEndpoints, const selector* pSelectors)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1; 

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1; 

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = get_endpoint_l8(e, 0);
					e1[ex][ey] = get_endpoint_l8(e, 1);
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const decoder_etc_block& src_block = pETC_Blocks[block_index];
				
				const uint16_t* pSrc_alpha_block = reinterpret_cast<const uint16_t*>(static_cast<const uint32_t*>(pAlpha_blocks) + x + (y * num_blocks_x));
				const endpoint* pAlpha_endpoints = &pEndpoints[pSrc_alpha_block[0]];
				const selector* pAlpha_selectors = &pSelectors[pSrc_alpha_block[1]];
				
				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);
				
				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				uint32_t base_r = g_etc_5_to_8[src_block.m_differential.m_red1];
				uint32_t base_g = g_etc_5_to_8[src_block.m_differential.m_green1];
				uint32_t base_b = g_etc_5_to_8[src_block.m_differential.m_blue1];

				const int* pInten_table48 = g_etc1_inten_tables48[src_block.m_differential.m_cw1];
				int by = (base_r + base_g + base_b) * 16;
				int block_colors_y_x16[4];
				block_colors_y_x16[0] = basisu::clamp<int>(by + pInten_table48[0], 0, 48 * 255);
				block_colors_y_x16[1] = basisu::clamp<int>(by + pInten_table48[1], 0, 48 * 255);
				block_colors_y_x16[2] = basisu::clamp<int>(by + pInten_table48[2], 0, 48 * 255);
				block_colors_y_x16[3] = basisu::clamp<int>(by + pInten_table48[3], 0, 48 * 255);

				uint32_t alpha_base_g = g_etc_5_to_8[pAlpha_endpoints->m_color5.g] * 16;
				const int* pInten_table16 = g_etc1_inten_tables16[pAlpha_endpoints->m_inten5];
				int alpha_block_colors_x16[4];
				alpha_block_colors_x16[0] = basisu::clamp<int>(alpha_base_g + pInten_table16[0], 0, 16 * 255);
				alpha_block_colors_x16[1] = basisu::clamp<int>(alpha_base_g + pInten_table16[1], 0, 16 * 255);
				alpha_block_colors_x16[2] = basisu::clamp<int>(alpha_base_g + pInten_table16[2], 0, 16 * 255);
				alpha_block_colors_x16[3] = basisu::clamp<int>(alpha_base_g + pInten_table16[3], 0, 16 * 255);

				// clamp((base_r + base_g + base_b) * 16 + color_inten[s] * 48) + clamp(alpha_base_g * 16 + alpha_inten[as] * 16)

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = get_endpoint_l8(e, 0); \
						e1[ex][ey] = get_endpoint_l8(e, 1); \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = block_colors_y_x16[(src_block.m_bytes[4 + ly] >> (lx * 2)) & 3] + alpha_block_colors_x16[(pAlpha_selectors->m_selectors[ly] >> (lx * 2)) & 3]; \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}
#endif // BASISD_SUPPORT_PVRTC1

#if BASISD_SUPPORT_BC7_MODE5
	static dxt_selector_range g_etc1_to_bc7_m5_selector_ranges[] =
	{
		{ 0, 3 },
		{ 1, 3 },
		{ 0, 2 },
		{ 1, 2 },
		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES = sizeof(g_etc1_to_bc7_m5_selector_ranges) / sizeof(g_etc1_to_bc7_m5_selector_ranges[0]);

	static uint32_t g_etc1_to_bc7_m5_selector_range_index[4][4];
	
	const uint32_t NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1_to_bc7_m5_selector_mappings[NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 },
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};

	struct etc1_to_bc7_m5_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};
		
	static const etc1_to_bc7_m5_solution g_etc1_to_bc7_m5_color[32 * 8 * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS * NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_bc7_m5_color.inc"
	};
	
	static dxt_selector_range g_etc1_to_bc7_m5a_selector_ranges[] =
	{
		{ 0, 3 },
		{ 1, 3 },
		{ 0, 2 },
		{ 1, 2 },
		{ 2, 3 },
		{ 0, 1 }
	};

	const uint32_t NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES = sizeof(g_etc1_to_bc7_m5a_selector_ranges) / sizeof(g_etc1_to_bc7_m5a_selector_ranges[0]);

	static uint32_t g_etc1_to_bc7_m5a_selector_range_index[4][4];

	struct etc1_g_to_bc7_m5a_conversion
	{
		uint8_t m_lo, m_hi;
		uint8_t m_trans;
	};

	static etc1_g_to_bc7_m5a_conversion g_etc1_g_to_bc7_m5a[8 * 32 * NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES] =
	{
		#include "basisu_transcoder_tables_bc7_m5_alpha.inc"
	};
	
	static inline uint32_t set_block_bits(uint8_t* pBytes, uint32_t val, uint32_t num_bits, uint32_t cur_ofs)
	{
		assert(num_bits < 32);
		assert(val < (1ULL << num_bits));

		uint32_t mask = static_cast<uint32_t>((1ULL << num_bits) - 1);

		while (num_bits)
		{
			const uint32_t n = basisu::minimum<uint32_t>(8 - (cur_ofs & 7), num_bits);

			pBytes[cur_ofs >> 3] &= ~static_cast<uint8_t>(mask << (cur_ofs & 7));
			pBytes[cur_ofs >> 3] |= static_cast<uint8_t>(val << (cur_ofs & 7));

			val >>= n;
			mask >>= n;

			num_bits -= n;
			cur_ofs += n;
		}

		return cur_ofs;
	}

#if BASISD_WRITE_NEW_BC7_MODE5_TABLES
	static void create_etc1_to_bc7_m5_color_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_bc7_m5_color.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_bc7_m5_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_bc7_m5_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 127; hi++)
						{
							for (uint32_t lo = 0; lo <= 127; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1) | (lo >> 6);
								colors[3] = (hi << 1) | (hi >> 6);

								colors[1] = (colors[0] * (64 - 21) + colors[3] * 21 + 32) / 64;
								colors[2] = (colors[0] * (64 - 43) + colors[3] * 43 + 32) / 64;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_bc7_m5_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}

	static void create_etc1_to_bc7_m5_alpha_conversion_table()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_bc7_m5_alpha.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_bc7_m5a_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_bc7_m5a_selector_ranges[sr].m_high;

					uint32_t best_lo = 0;
					uint32_t best_hi = 0;
					uint64_t best_err = UINT64_MAX;
					uint32_t best_output_selectors = 0;

					for (uint32_t hi = 0; hi <= 255; hi++)
					{
						for (uint32_t lo = 0; lo <= 255; lo++)
						{
							uint32_t colors[4];

							colors[0] = lo;
							colors[3] = hi;

							colors[1] = (colors[0] * (64 - 21) + colors[3] * 21 + 32) / 64;
							colors[2] = (colors[0] * (64 - 43) + colors[3] * 43 + 32) / 64;

							uint64_t total_err = 0;
							uint32_t output_selectors = 0;

							for (uint32_t s = low_selector; s <= high_selector; s++)
							{
								int best_mapping_err = INT_MAX;
								int best_k = 0;
								for (int k = 0; k < 4; k++)
								{
									int mapping_err = block_colors[s].g - colors[k];
									mapping_err *= mapping_err;

									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										mapping_err *= 5;

									if (mapping_err < best_mapping_err)
									{
										best_mapping_err = mapping_err;
										best_k = k;
									}
								} // k
								
								total_err += best_mapping_err;
								output_selectors |= (best_k << (s * 2));
							} // s

							if (total_err < best_err)
							{
								best_err = total_err;
								best_lo = lo;
								best_hi = hi;
								best_output_selectors = output_selectors;
							}

						} // lo
					} // hi
										
					fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, best_output_selectors);
					n++;
					if ((n & 31) == 31)
						fprintf(pFile, "\n");

				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif // BASISD_WRITE_NEW_BC7_MODE5_TABLES

	struct bc7_m5_match_entry
	{
		uint8_t m_hi;
		uint8_t m_lo;
	};

	static bc7_m5_match_entry g_bc7_m5_equals_1[256] =
	{
		{0,0},{1,0},{3,0},{4,0},{6,0},{7,0},{9,0},{10,0},{12,0},{13,0},{15,0},{16,0},{18,0},{20,0},{21,0},{23,0},
		{24,0},{26,0},{27,0},{29,0},{30,0},{32,0},{33,0},{35,0},{36,0},{38,0},{39,0},{41,0},{42,0},{44,0},{45,0},{47,0},
		{48,0},{50,0},{52,0},{53,0},{55,0},{56,0},{58,0},{59,0},{61,0},{62,0},{64,0},{65,0},{66,0},{68,0},{69,0},{71,0},
		{72,0},{74,0},{75,0},{77,0},{78,0},{80,0},{82,0},{83,0},{85,0},{86,0},{88,0},{89,0},{91,0},{92,0},{94,0},{95,0},
		{97,0},{98,0},{100,0},{101,0},{103,0},{104,0},{106,0},{107,0},{109,0},{110,0},{112,0},{114,0},{115,0},{117,0},{118,0},{120,0},
		{121,0},{123,0},{124,0},{126,0},{127,0},{127,1},{126,2},{126,3},{127,3},{127,4},{126,5},{126,6},{127,6},{127,7},{126,8},{126,9},
		{127,9},{127,10},{126,11},{126,12},{127,12},{127,13},{126,14},{125,15},{127,15},{126,16},{126,17},{127,17},{127,18},{126,19},{126,20},{127,20},
		{127,21},{126,22},{126,23},{127,23},{127,24},{126,25},{126,26},{127,26},{127,27},{126,28},{126,29},{127,29},{127,30},{126,31},{126,32},{127,32},
		{127,33},{126,34},{126,35},{127,35},{127,36},{126,37},{126,38},{127,38},{127,39},{126,40},{126,41},{127,41},{127,42},{126,43},{126,44},{127,44},
		{127,45},{126,46},{125,47},{127,47},{126,48},{126,49},{127,49},{127,50},{126,51},{126,52},{127,52},{127,53},{126,54},{126,55},{127,55},{127,56},
		{126,57},{126,58},{127,58},{127,59},{126,60},{126,61},{127,61},{127,62},{126,63},{125,64},{126,64},{126,65},{127,65},{127,66},{126,67},{126,68},
		{127,68},{127,69},{126,70},{126,71},{127,71},{127,72},{126,73},{126,74},{127,74},{127,75},{126,76},{125,77},{127,77},{126,78},{126,79},{127,79},
		{127,80},{126,81},{126,82},{127,82},{127,83},{126,84},{126,85},{127,85},{127,86},{126,87},{126,88},{127,88},{127,89},{126,90},{126,91},{127,91},
		{127,92},{126,93},{126,94},{127,94},{127,95},{126,96},{126,97},{127,97},{127,98},{126,99},{126,100},{127,100},{127,101},{126,102},{126,103},{127,103},
		{127,104},{126,105},{126,106},{127,106},{127,107},{126,108},{125,109},{127,109},{126,110},{126,111},{127,111},{127,112},{126,113},{126,114},{127,114},{127,115},
		{126,116},{126,117},{127,117},{127,118},{126,119},{126,120},{127,120},{127,121},{126,122},{126,123},{127,123},{127,124},{126,125},{126,126},{127,126},{127,127}
	};
	
	static void transcoder_init_bc7_mode5()
	{
#if 0
		// This is a little too much work to do at init time, so precompute it.
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = 256;
			for (int lo = 0; lo < 128; lo++)
			{
				for (int hi = 0; hi < 128; hi++)
				{
					const int lo_e = (lo << 1) | (lo >> 6);
					const int hi_e = (hi << 1) | (hi >> 6);

					// Selector 1
					int v = (lo_e * (64 - 21) + hi_e * 21 + 32) >> 6;
					int e = abs(v - i);

					if (e < lowest_e)
					{
						g_bc7_m5_equals_1[i].m_hi = static_cast<uint8_t>(hi);
						g_bc7_m5_equals_1[i].m_lo = static_cast<uint8_t>(lo);

						lowest_e = e;
					}

				} // hi
								
			} // lo
			
			printf("{%u,%u},", g_bc7_m5_equals_1[i].m_hi, g_bc7_m5_equals_1[i].m_lo);
			if ((i & 15) == 15) printf("\n");
		}
#endif

		for (uint32_t i = 0; i < NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_bc7_m5_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_bc7_m5_selector_ranges[i].m_high;
			g_etc1_to_bc7_m5_selector_range_index[l][h] = i;
		}

		for (uint32_t i = 0; i < NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_bc7_m5a_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_bc7_m5a_selector_ranges[i].m_high;
			g_etc1_to_bc7_m5a_selector_range_index[l][h] = i;
		}
	}

	static void convert_etc1s_to_bc7_m5_color(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		bc7_mode_5* pDst_block = static_cast<bc7_mode_5*>(pDst);
				
		// First ensure the block is cleared to all 0's
		static_cast<uint64_t*>(pDst)[0] = 0;
		static_cast<uint64_t*>(pDst)[1] = 0;

		// Set alpha to 255
		pDst_block->m_lo.m_mode = 1 << 5;
		pDst_block->m_lo.m_a0 = 255;
		pDst_block->m_lo.m_a1_0 = 63;
		pDst_block->m_hi.m_a1_1 = 3;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const uint32_t base_color_r = pEndpoints->m_color5.r;
		const uint32_t base_color_g = pEndpoints->m_color5.g;
		const uint32_t base_color_b = pEndpoints->m_color5.b;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (pSelector->m_num_unique_selectors == 1)
		{
			// Solid color block - use precomputed tables and set selectors to 1.
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(pEndpoints->m_color5, inten_table, low_selector, r, g, b);

			pDst_block->m_lo.m_r0 = g_bc7_m5_equals_1[r].m_lo;
			pDst_block->m_lo.m_g0 = g_bc7_m5_equals_1[g].m_lo;
			pDst_block->m_lo.m_b0 = g_bc7_m5_equals_1[b].m_lo;

			pDst_block->m_lo.m_r1 = g_bc7_m5_equals_1[r].m_hi;
			pDst_block->m_lo.m_g1 = g_bc7_m5_equals_1[g].m_hi;
			pDst_block->m_lo.m_b1 = g_bc7_m5_equals_1[b].m_hi;

			set_block_bits((uint8_t*)pDst, 0x2aaaaaab, 31, 66);
			return;
		}
		else if (pSelector->m_num_unique_selectors == 2)
		{
			// Only one or two unique selectors, so just switch to block truncation coding (BTC) to avoid quality issues on extreme blocks.
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, color32(base_color_r, base_color_g, base_color_b, 255), inten_table);

			const uint32_t r0 = block_colors[low_selector].r;
			const uint32_t g0 = block_colors[low_selector].g;
			const uint32_t b0 = block_colors[low_selector].b;

			const uint32_t r1 = block_colors[high_selector].r;
			const uint32_t g1 = block_colors[high_selector].g;
			const uint32_t b1 = block_colors[high_selector].b;

			pDst_block->m_lo.m_r0 = r0 >> 1;
			pDst_block->m_lo.m_g0 = g0 >> 1;
			pDst_block->m_lo.m_b0 = b0 >> 1;

			pDst_block->m_lo.m_r1 = r1 >> 1;
			pDst_block->m_lo.m_g1 = g1 >> 1;
			pDst_block->m_lo.m_b1 = b1 >> 1;

			uint32_t output_low_selector = 0, output_bit_offset = 0, output_bits = 0;

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t os = (s == low_selector) ? output_low_selector : (3 ^ output_low_selector);

					uint32_t num_bits = 2;

					if ((x | y) == 0)
					{
						if (os & 2)
						{
							pDst_block->m_lo.m_r0 = r1 >> 1;
							pDst_block->m_lo.m_g0 = g1 >> 1;
							pDst_block->m_lo.m_b0 = b1 >> 1;

							pDst_block->m_lo.m_r1 = r0 >> 1;
							pDst_block->m_lo.m_g1 = g0 >> 1;
							pDst_block->m_lo.m_b1 = b0 >> 1;

							output_low_selector = 3;
							os = 0;
						}

						num_bits = 1;
					}

					output_bits |= (os << output_bit_offset);
					output_bit_offset += num_bits;
				}
			}

			set_block_bits((uint8_t*)pDst, output_bits, 31, 66);
			return;
		}

		const uint32_t selector_range_table = g_etc1_to_bc7_m5_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1_to_bc7_m5_solution* pTable_r = &g_etc1_to_bc7_m5_color[(inten_table * 32 + base_color_r) * (NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS];
		const etc1_to_bc7_m5_solution* pTable_g = &g_etc1_to_bc7_m5_color[(inten_table * 32 + base_color_g) * (NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS];
		const etc1_to_bc7_m5_solution* pTable_b = &g_etc1_to_bc7_m5_color[(inten_table * 32 + base_color_b) * (NUM_ETC1_TO_BC7_M5_SELECTOR_RANGES * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1_TO_BC7_M5_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		const uint8_t* pSelectors_xlat = &g_etc1_to_bc7_m5_selector_mappings[best_mapping][0];

		uint32_t s_inv = 0;
		if (pSelectors_xlat[pSelector->get_selector(0, 0)] & 2)
		{
			pDst_block->m_lo.m_r0 = pTable_r[best_mapping].m_hi;
			pDst_block->m_lo.m_g0 = pTable_g[best_mapping].m_hi;
			pDst_block->m_lo.m_b0 = pTable_b[best_mapping].m_hi;

			pDst_block->m_lo.m_r1 = pTable_r[best_mapping].m_lo;
			pDst_block->m_lo.m_g1 = pTable_g[best_mapping].m_lo;
			pDst_block->m_lo.m_b1 = pTable_b[best_mapping].m_lo;
			
			s_inv = 3;
		}
		else
		{
			pDst_block->m_lo.m_r0 = pTable_r[best_mapping].m_lo;
			pDst_block->m_lo.m_g0 = pTable_g[best_mapping].m_lo;
			pDst_block->m_lo.m_b0 = pTable_b[best_mapping].m_lo;

			pDst_block->m_lo.m_r1 = pTable_r[best_mapping].m_hi;
			pDst_block->m_lo.m_g1 = pTable_g[best_mapping].m_hi;
			pDst_block->m_lo.m_b1 = pTable_b[best_mapping].m_hi;
		}

		uint32_t output_bits = 0, output_bit_ofs = 0;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				const uint32_t s = pSelector->get_selector(x, y);
				
				const uint32_t os = pSelectors_xlat[s] ^ s_inv;

				output_bits |= (os << output_bit_ofs);

				output_bit_ofs += (((x | y) == 0) ? 1 : 2);
			}
		}

		set_block_bits((uint8_t*)pDst, output_bits, 31, 66);
	}

	static void convert_etc1s_to_bc7_m5_alpha(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		bc7_mode_5* pDst_block = static_cast<bc7_mode_5*>(pDst);

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const uint32_t base_color_r = pEndpoints->m_color5.r;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (pSelector->m_num_unique_selectors == 1)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(pEndpoints->m_color5, inten_table, low_selector, r);

			pDst_block->m_lo.m_a0 = r;
			pDst_block->m_lo.m_a1_0 = r & 63;
			pDst_block->m_hi.m_a1_1 = r >> 6;
					  
			return;
		}
		else if (pSelector->m_num_unique_selectors == 2)
		{
			// Only one or two unique selectors, so just switch to block truncation coding (BTC) to avoid quality issues on extreme blocks.
			int block_colors[4];

			decoder_etc_block::get_block_colors5_g(block_colors, pEndpoints->m_color5, inten_table);

			pDst_block->m_lo.m_a0 = block_colors[low_selector];
			pDst_block->m_lo.m_a1_0 = block_colors[high_selector] & 63;
			pDst_block->m_hi.m_a1_1 = block_colors[high_selector] >> 6;

			uint32_t output_low_selector = 0, output_bit_offset = 0, output_bits = 0;

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					const uint32_t s = pSelector->get_selector(x, y);
					uint32_t os = (s == low_selector) ? output_low_selector : (3 ^ output_low_selector);

					uint32_t num_bits = 2;

					if ((x | y) == 0)
					{
						if (os & 2)
						{
							pDst_block->m_lo.m_a0 = block_colors[high_selector];
							pDst_block->m_lo.m_a1_0 = block_colors[low_selector] & 63;
							pDst_block->m_hi.m_a1_1 = block_colors[low_selector] >> 6;

							output_low_selector = 3;
							os = 0;
						}

						num_bits = 1;
					}

					output_bits |= (os << output_bit_offset);
					output_bit_offset += num_bits;
				}
			}

			set_block_bits((uint8_t*)pDst, output_bits, 31, 97);
			return;
		}

		const uint32_t selector_range_table = g_etc1_to_bc7_m5a_selector_range_index[low_selector][high_selector];
						
		const etc1_g_to_bc7_m5a_conversion* pTable = &g_etc1_g_to_bc7_m5a[inten_table * (32 * NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES) + base_color_r * NUM_ETC1_TO_BC7_M5A_SELECTOR_RANGES + selector_range_table];

		pDst_block->m_lo.m_a0 = pTable->m_lo;
		pDst_block->m_lo.m_a1_0 = pTable->m_hi & 63;
		pDst_block->m_hi.m_a1_1 = pTable->m_hi >> 6;

		uint32_t output_bit_offset = 0, output_bits = 0, selector_trans = pTable->m_trans;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				const uint32_t s = pSelector->get_selector(x, y);
				uint32_t os = (selector_trans >> (s * 2)) & 3;

				uint32_t num_bits = 2;

				if ((x | y) == 0)
				{
					if (os & 2)
					{
						pDst_block->m_lo.m_a0 = pTable->m_hi;
						pDst_block->m_lo.m_a1_0 = pTable->m_lo & 63;
						pDst_block->m_hi.m_a1_1 = pTable->m_lo >> 6;

						selector_trans ^= 0xFF;
						os ^= 3;
					}

					num_bits = 1;
				}

				output_bits |= (os << output_bit_offset);
				output_bit_offset += num_bits;
			}
		}

		set_block_bits((uint8_t*)pDst, output_bits, 31, 97);
	}

#if 0
	static inline vec3F rgb_to_ycocg(const vec3F& rgb)
	{
		return vec3F(rgb.dot(vec3F(0.25f, 0.5f, 0.25f)), rgb.dot(vec3F(0.5f, 0.0f, -0.5f)), rgb.dot(vec3F(-0.25f, 0.5f, -0.25f)));
	}
#endif

	static inline vec2F rgb_to_cocg(const vec3F& rgb)
	{
		return vec2F(rgb.dot(vec3F(0.5f, 0.0f, -0.5f)), rgb.dot(vec3F(-0.25f, 0.5f, -0.25f)));
	}

	static inline vec3F ycocg_to_rgb(const vec3F& ycocg)
	{
		return vec3F(ycocg.dot(vec3F(1.0f, 1.0f, -1.0f)), ycocg.dot(vec3F(1.0f, 0.0f, 1.0f)), ycocg.dot(vec3F(1.0f, -1.0f, -1.0f)));
	}

#if 0
	static inline vec3F color32_to_vec3F(const color32& c)
	{
		return vec3F(c.r, c.g, c.b);
	}
#endif

#if 0
	static inline vec3F color5_to_ycocg(const endpoint& e)
	{
		const int r = (e.m_color5[0] << 3) | (e.m_color5[0] >> 2);
		const int g = (e.m_color5[1] << 3) | (e.m_color5[1] >> 2);
		const int b = (e.m_color5[2] << 3) | (e.m_color5[2] >> 2);
		return rgb_to_ycocg(vec3F((float)r, (float)g, (float)b));
	}
#endif

	static inline vec2F color5_to_cocg(const endpoint& e)
	{
		const int r = (e.m_color5[0] << 3) | (e.m_color5[0] >> 2);
		const int g = (e.m_color5[1] << 3) | (e.m_color5[1] >> 2);
		const int b = (e.m_color5[2] << 3) | (e.m_color5[2] >> 2);
		return rgb_to_cocg(vec3F((float)r, (float)g, (float)b));
	}

	static inline uint32_t bc7_7_to_8(uint32_t v)
	{
		assert(v < 128);
		return (v << 1) | (v >> 6);
	}

	static inline uint32_t bc7_interp2(uint32_t l, uint32_t h, uint32_t w)
	{
		assert(w < 4);
		return (l * (64 - basist::g_bc7_weights2[w]) + h * basist::g_bc7_weights2[w] + 32) >> 6;
	}

	static inline vec2F get_endpoint_cocg_clamped(int bx, int by, const basisu::vector2D<uint16_t>& decoded_endpoints, const endpoint* pEndpoints)
	{
		const uint32_t endpoint_index = decoded_endpoints.at_clamped(bx, by);
		return color5_to_cocg(pEndpoints[endpoint_index]);
	}

	static void chroma_filter_bc7_mode5(const basisu::vector2D<uint16_t>& decoded_endpoints, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t output_row_pitch_in_blocks_or_pixels, const endpoint *pEndpoints)
	{
		const bool hq_bc7_mode_5_encoder_mode = false;

		const int CHROMA_THRESH = 10;
		
		uint32_t total_filtered_blocks = 0;
		BASISU_NOTE_UNUSED(total_filtered_blocks);

		for (int by = 0; by < (int)num_blocks_y; by++)
		{
			for (int bx = 0; bx < (int)num_blocks_x; bx++)
			{
				vec2F center_cocg(color5_to_cocg(pEndpoints[decoded_endpoints(bx, by)]));
		
				//bool filter_flag = false;
				for (int dy = -1; dy <= 1; dy++)
				{
					const int oy = by + dy;
					if ((oy < 0) || (oy >= (int)num_blocks_y))
						continue;

					for (int dx = -1; dx <= 1; dx++)
					{
						if ((dx | dy) == 0)
							continue;

						const int ox = bx + dx;
						if ((ox < 0) || (ox >= (int)num_blocks_x))
							continue;

						vec2F nearby_cocg(color5_to_cocg(pEndpoints[decoded_endpoints(ox, oy)]));

						float delta_co = fabsf(nearby_cocg[0] - center_cocg[0]);
						float delta_cg = fabsf(nearby_cocg[1] - center_cocg[1]);

						if ((delta_co > CHROMA_THRESH) || (delta_cg > CHROMA_THRESH))
						{
							//filter_flag = true;
							goto do_filter;
						}

					} // dx
				} // dy

				continue;

			do_filter:;

				total_filtered_blocks++;

				bc7_mode_5* pDst_block = (bc7_mode_5*)(static_cast<uint8_t*>(pDst_blocks) + (bx + by * output_row_pitch_in_blocks_or_pixels) * sizeof(bc7_mode_5));
				
				//memset(pDst_block, 0x80, 16);

				int lr = bc7_7_to_8(pDst_block->m_lo.m_r0);
				int lg = bc7_7_to_8(pDst_block->m_lo.m_g0);
				int lb = bc7_7_to_8(pDst_block->m_lo.m_b0);

				int hr = bc7_7_to_8(pDst_block->m_lo.m_r1);
				int hg = bc7_7_to_8(pDst_block->m_lo.m_g1);
				int hb = bc7_7_to_8(pDst_block->m_lo.m_b1);

				float y_vals[4];
				for (uint32_t i = 0; i < 4; i++)
				{
					int cr = bc7_interp2(lr, hr, i);
					int cg = bc7_interp2(lg, hg, i);
					int cb = bc7_interp2(lb, hb, i);
					y_vals[i] = (float)cr * .25f + (float)cg * .5f + (float)cb * .25f;
				} // i

				uint64_t sel_bits = pDst_block->m_hi_bits >> 2;

				float block_y_vals[16]; // [y][x]
				float y_sum = 0.0f, y_sum_sq = 0.0f;
				
				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t sel = sel_bits & (i ? 3 : 1);
					sel_bits >>= (i ? 2 : 1);
					float y = y_vals[sel];
					block_y_vals[i] = y;
					y_sum += y;
					y_sum_sq += y * y;
					
				} // i

				const float S = 1.0f / 16.0f;
				float y_var = (y_sum_sq * S) - basisu::squaref(y_sum * S);

				// Don't bother if the block is too smooth.
				const float Y_VAR_SKIP_THRESH = 3.0f;
				if (y_var < Y_VAR_SKIP_THRESH)
					continue;

				color32 block_to_pack[16];

				for (int bpy = 0; bpy < 4; bpy++)
				{
					const int uby = by + ((bpy - 2) >> 2);

					for (int bpx = 0; bpx < 4; bpx++)
					{
						const float fx = ((float)((bpx + 2) & 3) + .5f) * (1.0f / 4.0f);
						const float fy = ((float)((bpy + 2) & 3) + .5f) * (1.0f / 4.0f);

						const int ubx = bx + ((bpx - 2) >> 2);
												
						vec2F a(get_endpoint_cocg_clamped(ubx, uby, decoded_endpoints, pEndpoints));
						vec2F b(get_endpoint_cocg_clamped(ubx + 1, uby, decoded_endpoints, pEndpoints));
						vec2F c(get_endpoint_cocg_clamped(ubx, uby + 1, decoded_endpoints, pEndpoints));
						vec2F d(get_endpoint_cocg_clamped(ubx + 1, uby + 1, decoded_endpoints, pEndpoints));

						assert((fx >= 0) && (fx <= 1.0f) && (fy >= 0) && (fy <= 1.0f));
												
						// TODO: Could merge this into 4 muls on each corner by weights
						vec2F ab = vec2F::lerp(a, b, fx);
						vec2F cd = vec2F::lerp(c, d, fx);
						vec2F f = vec2F::lerp(ab, cd, fy);

						vec3F final_ycocg(block_y_vals[bpx + bpy * 4], f[0], f[1]);

						vec3F final_conv(ycocg_to_rgb(final_ycocg));
						final_conv.clamp(0.0f, 255.0f);

						block_to_pack[bpx + bpy * 4].set_noclamp_rgba((int)(.5f + final_conv[0]), (int)(.5f + final_conv[1]), (int)(.5f + final_conv[2]), 255);

					} // x
				} // y

				bc7_mode_5_encoder::encode_bc7_mode_5_block(pDst_block, block_to_pack, hq_bc7_mode_5_encoder_mode);
				
			} // bx
		} // by

		//basisu::fmt_printf("Chroma thresh: {}, Total blocks to filter: {} out of {} {}\n", CHROMA_THRESH, total_filtered_blocks, num_blocks_x * num_blocks_y, (float)total_filtered_blocks * 100.0f / (num_blocks_x * num_blocks_y));
	}
#endif // BASISD_SUPPORT_BC7_MODE5

#if BASISD_SUPPORT_ETC2_EAC_A8 || BASISD_SUPPORT_UASTC
	static const uint8_t g_etc2_eac_a8_sel4[6] = { 0x92, 0x49, 0x24, 0x92, 0x49, 0x24 };
#endif

#if BASISD_SUPPORT_ETC2_EAC_A8
	static void convert_etc1s_to_etc2_eac_a8(eac_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector)
	{
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(base_color, inten_table, low_selector, r);

			// Constant alpha block
			// Select table 13, use selector 4 (0), set multiplier to 1 and base color g
			pDst_block->m_base = r;
			pDst_block->m_table = 13;
			pDst_block->m_multiplier = 1;

			// selectors are all 4's
			memcpy(pDst_block->m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

			return;
		}

		uint32_t selector_range_table = 0;
		for (selector_range_table = 0; selector_range_table < NUM_ETC2_EAC_SELECTOR_RANGES; selector_range_table++)
			if ((low_selector == s_etc2_eac_selector_ranges[selector_range_table].m_low) && (high_selector == s_etc2_eac_selector_ranges[selector_range_table].m_high))
				break;
		if (selector_range_table >= NUM_ETC2_EAC_SELECTOR_RANGES)
			selector_range_table = 0;

		const etc1_g_to_eac_conversion* pTable_entry = &s_etc1_g_to_etc2_a8[base_color.r + inten_table * 32][selector_range_table];

		pDst_block->m_base = pTable_entry->m_base;
		pDst_block->m_table = pTable_entry->m_table_mul >> 4;
		pDst_block->m_multiplier = pTable_entry->m_table_mul & 15;

		uint64_t selector_bits = 0;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s = pSelector->get_selector(x, y);

				uint32_t ds = (pTable_entry->m_trans >> (s * 3)) & 7;

				const uint32_t dst_ofs = 45 - (y + x * 4) * 3;
				selector_bits |= (static_cast<uint64_t>(ds) << dst_ofs);
			}
		}

		pDst_block->set_selector_bits(selector_bits);
	}
#endif // BASISD_SUPPORT_ETC2_EAC_A8

#if BASISD_SUPPORT_ETC2_EAC_RG11
	static const etc1_g_to_eac_conversion s_etc1_g_to_etc2_r11[32 * 8][NUM_ETC2_EAC_SELECTOR_RANGES] =
	{
		{{0,1,3328},{0,1,3328},{0,16,457},{0,16,456}},
		{{0,226,3936},{0,226,3936},{0,17,424},{8,0,472}},
		{{6,178,4012},{6,178,4008},{0,146,501},{16,0,472}},
		{{14,178,4012},{14,178,4008},{8,146,501},{24,0,472}},
		{{23,178,4012},{23,178,4008},{17,146,501},{33,0,472}},
		{{31,178,4012},{31,178,4008},{25,146,501},{41,0,472}},
		{{39,178,4012},{39,178,4008},{33,146,501},{49,0,472}},
		{{47,178,4012},{47,178,4008},{41,146,501},{27,228,496}},
		{{56,178,4012},{56,178,4008},{50,146,501},{36,228,496}},
		{{64,178,4012},{64,178,4008},{58,146,501},{44,228,496}},
		{{72,178,4012},{72,178,4008},{66,146,501},{52,228,496}},
		{{80,178,4012},{80,178,4008},{74,146,501},{60,228,496}},
		{{89,178,4012},{89,178,4008},{83,146,501},{69,228,496}},
		{{97,178,4012},{97,178,4008},{91,146,501},{77,228,496}},
		{{105,178,4012},{105,178,4008},{99,146,501},{85,228,496}},
		{{113,178,4012},{113,178,4008},{107,146,501},{93,228,496}},
		{{122,178,4012},{122,178,4008},{116,146,501},{102,228,496}},
		{{130,178,4012},{130,178,4008},{124,146,501},{110,228,496}},
		{{138,178,4012},{138,178,4008},{132,146,501},{118,228,496}},
		{{146,178,4012},{146,178,4008},{140,146,501},{126,228,496}},
		{{155,178,4012},{155,178,4008},{149,146,501},{135,228,496}},
		{{163,178,4012},{163,178,4008},{157,146,501},{143,228,496}},
		{{171,178,4012},{171,178,4008},{165,146,501},{151,228,496}},
		{{179,178,4012},{179,178,4008},{173,146,501},{159,228,496}},
		{{188,178,4012},{188,178,4008},{182,146,501},{168,228,496}},
		{{196,178,4012},{196,178,4008},{190,146,501},{176,228,496}},
		{{204,178,4012},{204,178,4008},{198,146,501},{184,228,496}},
		{{212,178,4012},{212,178,4008},{206,146,501},{192,228,496}},
		{{221,178,4012},{221,178,4008},{215,146,501},{201,228,496}},
		{{229,178,4012},{229,178,4008},{223,146,501},{209,228,496}},
		{{235,66,4012},{221,100,4008},{231,146,501},{217,228,496}},
		{{211,102,4085},{254,32,4040},{211,102,501},{254,32,456}},
		{{0,2,3328},{0,2,3328},{0,1,320},{0,1,320}},
		{{7,162,3905},{7,162,3904},{0,17,480},{0,17,480}},
		{{15,162,3906},{15,162,3904},{1,117,352},{1,117,352}},
		{{23,162,3906},{23,162,3904},{5,34,500},{4,53,424}},
		{{32,162,3906},{32,162,3904},{14,34,500},{3,69,424}},
		{{40,162,3906},{40,162,3904},{22,34,500},{1,133,496}},
		{{48,162,3906},{48,162,3904},{30,34,500},{4,85,496}},
		{{56,162,3906},{56,162,3904},{38,34,500},{12,85,496}},
		{{65,162,3906},{65,162,3904},{47,34,500},{1,106,424}},
		{{73,162,3906},{73,162,3904},{55,34,500},{9,106,424}},
		{{81,162,3906},{81,162,3904},{63,34,500},{7,234,496}},
		{{89,162,3906},{89,162,3904},{71,34,500},{15,234,496}},
		{{98,162,3906},{98,162,3904},{80,34,500},{24,234,496}},
		{{106,162,3906},{106,162,3904},{88,34,500},{32,234,496}},
		{{114,162,3906},{114,162,3904},{96,34,500},{40,234,496}},
		{{122,162,3906},{122,162,3904},{104,34,500},{48,234,496}},
		{{131,162,3906},{131,162,3904},{113,34,500},{57,234,496}},
		{{139,162,3906},{139,162,3904},{121,34,500},{65,234,496}},
		{{147,162,3906},{147,162,3904},{129,34,500},{73,234,496}},
		{{155,162,3906},{155,162,3904},{137,34,500},{81,234,496}},
		{{164,162,3906},{164,162,3904},{146,34,500},{90,234,496}},
		{{172,162,3906},{172,162,3904},{154,34,500},{98,234,496}},
		{{180,162,3906},{180,162,3904},{162,34,500},{106,234,496}},
		{{188,162,3906},{188,162,3904},{170,34,500},{114,234,496}},
		{{197,162,3906},{197,162,3904},{179,34,500},{123,234,496}},
		{{205,162,3906},{205,162,3904},{187,34,500},{131,234,496}},
		{{213,162,3906},{213,162,3904},{195,34,500},{139,234,496}},
		{{221,162,3906},{221,162,3904},{203,34,500},{147,234,496}},
		{{230,162,3906},{230,162,3904},{212,34,500},{156,234,496}},
		{{238,162,3906},{174,106,4008},{220,34,500},{164,234,496}},
		{{240,178,4001},{182,106,4008},{228,34,500},{172,234,496}},
		{{166,108,4085},{115,31,4080},{166,108,501},{115,31,496}},
		{{1,68,3328},{1,68,3328},{0,1,384},{0,1,384}},
		{{1,51,3968},{1,51,3968},{0,2,384},{0,2,384}},
		{{21,18,3851},{21,18,3848},{1,50,488},{1,50,488}},
		{{26,195,3851},{29,18,3848},{0,67,488},{0,67,488}},
		{{35,195,3851},{38,18,3848},{12,115,488},{0,3,496}},
		{{43,195,3851},{46,18,3848},{20,115,488},{2,6,424}},
		{{51,195,3851},{54,18,3848},{36,66,482},{4,22,424}},
		{{59,195,3851},{62,18,3848},{44,66,482},{3,73,424}},
		{{68,195,3851},{71,18,3848},{53,66,482},{3,22,496}},
		{{76,195,3851},{79,18,3848},{61,66,482},{2,137,496}},
		{{84,195,3851},{87,18,3848},{69,66,482},{1,89,496}},
		{{92,195,3851},{95,18,3848},{77,66,482},{9,89,496}},
		{{101,195,3851},{104,18,3848},{86,66,482},{18,89,496}},
		{{109,195,3851},{112,18,3848},{94,66,482},{26,89,496}},
		{{117,195,3851},{120,18,3848},{102,66,482},{34,89,496}},
		{{125,195,3851},{128,18,3848},{110,66,482},{42,89,496}},
		{{134,195,3851},{137,18,3848},{119,66,482},{51,89,496}},
		{{141,195,3907},{145,18,3848},{127,66,482},{59,89,496}},
		{{149,195,3907},{153,18,3848},{135,66,482},{67,89,496}},
		{{157,195,3907},{161,18,3848},{143,66,482},{75,89,496}},
		{{166,195,3907},{170,18,3848},{152,66,482},{84,89,496}},
		{{174,195,3907},{178,18,3848},{160,66,482},{92,89,496}},
		{{182,195,3907},{186,18,3848},{168,66,482},{100,89,496}},
		{{190,195,3907},{194,18,3848},{176,66,482},{108,89,496}},
		{{199,195,3907},{203,18,3848},{185,66,482},{117,89,496}},
		{{207,195,3907},{211,18,3848},{193,66,482},{125,89,496}},
		{{215,195,3907},{219,18,3848},{201,66,482},{133,89,496}},
		{{223,195,3907},{227,18,3848},{209,66,482},{141,89,496}},
		{{232,195,3907},{168,89,4008},{218,66,482},{150,89,496}},
		{{236,18,3907},{176,89,4008},{226,66,482},{158,89,496}},
		{{158,90,4085},{103,31,4080},{158,90,501},{103,31,496}},
		{{166,90,4085},{111,31,4080},{166,90,501},{111,31,496}},
		{{0,70,3328},{0,70,3328},{0,17,448},{0,17,448}},
		{{0,117,3904},{0,117,3904},{0,35,384},{0,35,384}},
		{{13,165,3905},{13,165,3904},{2,211,480},{2,211,480}},
		{{21,165,3906},{21,165,3904},{1,51,488},{1,51,488}},
		{{30,165,3906},{30,165,3904},{7,61,352},{7,61,352}},
		{{38,165,3906},{38,165,3904},{2,125,352},{2,125,352}},
		{{46,165,3906},{46,165,3904},{1,37,500},{10,125,352}},
		{{54,165,3906},{54,165,3904},{9,37,500},{5,61,424}},
		{{63,165,3906},{63,165,3904},{18,37,500},{1,189,424}},
		{{71,165,3906},{71,165,3904},{26,37,500},{9,189,424}},
		{{79,165,3906},{79,165,3904},{34,37,500},{4,77,424}},
		{{87,165,3906},{87,165,3904},{42,37,500},{12,77,424}},
		{{96,165,3906},{96,165,3904},{51,37,500},{8,93,424}},
		{{104,165,3906},{104,165,3904},{59,37,500},{3,141,496}},
		{{112,165,3906},{112,165,3904},{68,37,500},{11,141,496}},
		{{120,165,3906},{120,165,3904},{76,37,500},{6,93,496}},
		{{129,165,3906},{129,165,3904},{85,37,500},{15,93,496}},
		{{70,254,4012},{137,165,3904},{93,37,500},{23,93,496}},
		{{145,165,3906},{145,165,3904},{101,37,500},{31,93,496}},
		{{86,254,4012},{153,165,3904},{109,37,500},{39,93,496}},
		{{163,165,3906},{162,165,3904},{118,37,500},{48,93,496}},
		{{171,165,3906},{170,165,3904},{126,37,500},{56,93,496}},
		{{179,165,3906},{178,165,3904},{134,37,500},{64,93,496}},
		{{187,165,3906},{187,165,3904},{142,37,500},{72,93,496}},
		{{196,165,3906},{196,165,3904},{151,37,500},{81,93,496}},
		{{204,165,3906},{204,165,3904},{159,37,500},{89,93,496}},
		{{212,165,3906},{136,77,4008},{167,37,500},{97,93,496}},
		{{220,165,3906},{131,93,4008},{175,37,500},{105,93,496}},
		{{214,181,4001},{140,93,4008},{184,37,500},{114,93,496}},
		{{222,181,4001},{148,93,4008},{192,37,500},{122,93,496}},
		{{115,95,4085},{99,31,4080},{115,95,501},{99,31,496}},
		{{123,95,4085},{107,31,4080},{123,95,501},{107,31,496}},
		{{0,102,3840},{0,102,3840},{0,18,384},{0,18,384}},
		{{5,167,3904},{5,167,3904},{0,13,256},{0,13,256}},
		{{4,54,3968},{4,54,3968},{1,67,448},{1,67,448}},
		{{30,198,3850},{30,198,3848},{0,3,480},{0,3,480}},
		{{39,198,3850},{39,198,3848},{3,52,488},{3,52,488}},
		{{47,198,3851},{47,198,3848},{3,4,488},{3,4,488}},
		{{55,198,3851},{55,198,3848},{1,70,488},{1,70,488}},
		{{53,167,3906},{63,198,3848},{3,22,488},{3,22,488}},
		{{62,167,3906},{72,198,3848},{24,118,488},{0,6,496}},
		{{70,167,3906},{80,198,3848},{32,118,488},{2,89,488}},
		{{78,167,3906},{88,198,3848},{40,118,488},{1,73,496}},
		{{86,167,3906},{96,198,3848},{48,118,488},{0,28,424}},
		{{95,167,3906},{105,198,3848},{57,118,488},{9,28,424}},
		{{103,167,3906},{113,198,3848},{65,118,488},{5,108,496}},
		{{111,167,3906},{121,198,3848},{73,118,488},{13,108,496}},
		{{119,167,3906},{129,198,3848},{81,118,488},{21,108,496}},
		{{128,167,3906},{138,198,3848},{90,118,488},{6,28,496}},
		{{136,167,3906},{146,198,3848},{98,118,488},{14,28,496}},
		{{145,167,3906},{154,198,3848},{106,118,488},{22,28,496}},
		{{153,167,3906},{162,198,3848},{114,118,488},{30,28,496}},
		{{162,167,3906},{171,198,3848},{123,118,488},{39,28,496}},
		{{170,167,3906},{179,198,3848},{131,118,488},{47,28,496}},
		{{178,167,3906},{187,198,3848},{139,118,488},{55,28,496}},
		{{186,167,3906},{195,198,3848},{147,118,488},{63,28,496}},
		{{194,167,3906},{120,12,4008},{156,118,488},{72,28,496}},
		{{206,198,3907},{116,28,4008},{164,118,488},{80,28,496}},
		{{214,198,3907},{124,28,4008},{172,118,488},{88,28,496}},
		{{222,198,3395},{132,28,4008},{180,118,488},{96,28,496}},
		{{207,134,4001},{141,28,4008},{189,118,488},{105,28,496}},
		{{95,30,4085},{86,31,4080},{95,30,501},{86,31,496}},
		{{103,30,4085},{94,31,4080},{103,30,501},{94,31,496}},
		{{111,30,4085},{102,31,4080},{111,30,501},{102,31,496}},
		{{0,104,3840},{0,104,3840},{0,18,448},{0,18,448}},
		{{4,39,3904},{4,39,3904},{0,4,384},{0,4,384}},
		{{0,56,3968},{0,56,3968},{0,84,448},{0,84,448}},
		{{6,110,3328},{6,110,3328},{0,20,448},{0,20,448}},
		{{41,200,3850},{41,200,3848},{1,4,480},{1,4,480}},
		{{49,200,3850},{49,200,3848},{1,8,416},{1,8,416}},
		{{57,200,3851},{57,200,3848},{1,38,488},{1,38,488}},
		{{65,200,3851},{65,200,3848},{1,120,488},{1,120,488}},
		{{74,200,3851},{74,200,3848},{2,72,488},{2,72,488}},
		{{68,6,3907},{82,200,3848},{2,24,488},{2,24,488}},
		{{77,6,3907},{90,200,3848},{26,120,488},{10,24,488}},
		{{97,63,3330},{98,200,3848},{34,120,488},{2,8,496}},
		{{106,63,3330},{107,200,3848},{43,120,488},{3,92,488}},
		{{114,63,3330},{115,200,3848},{51,120,488},{11,92,488}},
		{{122,63,3330},{123,200,3848},{59,120,488},{7,76,496}},
		{{130,63,3330},{131,200,3848},{67,120,488},{15,76,496}},
		{{139,63,3330},{140,200,3848},{76,120,488},{24,76,496}},
		{{147,63,3330},{148,200,3848},{84,120,488},{32,76,496}},
		{{155,63,3330},{156,200,3848},{92,120,488},{40,76,496}},
		{{164,63,3330},{164,200,3848},{100,120,488},{48,76,496}},
		{{173,63,3330},{173,200,3848},{109,120,488},{57,76,496}},
		{{184,6,3851},{181,200,3848},{117,120,488},{65,76,496}},
		{{192,6,3851},{133,28,3936},{125,120,488},{73,76,496}},
		{{189,200,3907},{141,28,3936},{133,120,488},{81,76,496}},
		{{198,200,3907},{138,108,4000},{142,120,488},{90,76,496}},
		{{206,200,3907},{146,108,4000},{150,120,488},{98,76,496}},
		{{214,200,3395},{154,108,4000},{158,120,488},{106,76,496}},
		{{190,136,4001},{162,108,4000},{166,120,488},{114,76,496}},
		{{123,30,4076},{87,15,4080},{123,30,492},{87,15,496}},
		{{117,110,4084},{80,31,4080},{117,110,500},{80,31,496}},
		{{125,110,4084},{88,31,4080},{125,110,500},{88,31,496}},
		{{133,110,4084},{96,31,4080},{133,110,500},{96,31,496}},
		{{9,56,3904},{9,56,3904},{0,67,448},{0,67,448}},
		{{1,8,3904},{1,8,3904},{1,84,448},{1,84,448}},
		{{1,124,3904},{1,124,3904},{0,39,384},{0,39,384}},
		{{9,124,3904},{9,124,3904},{1,4,448},{1,4,448}},
		{{6,76,3904},{6,76,3904},{0,70,448},{0,70,448}},
		{{62,6,3859},{62,6,3856},{2,38,480},{2,38,480}},
		{{70,6,3859},{70,6,3856},{5,43,416},{5,43,416}},
		{{78,6,3859},{78,6,3856},{2,11,416},{2,11,416}},
		{{87,6,3859},{87,6,3856},{0,171,488},{0,171,488}},
		{{67,8,3906},{95,6,3856},{8,171,488},{8,171,488}},
		{{75,8,3907},{103,6,3856},{5,123,488},{5,123,488}},
		{{83,8,3907},{111,6,3856},{2,75,488},{2,75,488}},
		{{92,8,3907},{120,6,3856},{0,27,488},{0,27,488}},
		{{100,8,3907},{128,6,3856},{8,27,488},{8,27,488}},
		{{120,106,3843},{136,6,3856},{99,6,387},{16,27,488}},
		{{128,106,3843},{144,6,3856},{107,6,387},{2,11,496}},
		{{137,106,3843},{153,6,3856},{117,6,387},{11,11,496}},
		{{145,106,3843},{161,6,3856},{125,6,387},{19,11,496}},
		{{163,8,3851},{137,43,3904},{133,6,387},{27,11,496}},
		{{171,8,3851},{145,43,3904},{141,6,387},{35,11,496}},
		{{180,8,3851},{110,11,4000},{150,6,387},{44,11,496}},
		{{188,8,3851},{118,11,4000},{158,6,387},{52,11,496}},
		{{172,72,3907},{126,11,4000},{166,6,387},{60,11,496}},
		{{174,6,3971},{134,11,4000},{174,6,387},{68,11,496}},
		{{183,6,3971},{143,11,4000},{183,6,387},{77,11,496}},
		{{191,6,3971},{151,11,4000},{191,6,387},{85,11,496}},
		{{199,6,3971},{159,11,4000},{199,6,387},{93,11,496}},
		{{92,12,4084},{69,15,4080},{92,12,500},{69,15,496}},
		{{101,12,4084},{78,15,4080},{101,12,500},{78,15,496}},
		{{110,12,4084},{86,15,4080},{110,12,500},{86,15,496}},
		{{118,12,4084},{79,31,4080},{118,12,500},{79,31,496}},
		{{126,12,4084},{87,31,4080},{126,12,500},{87,31,496}},
		{{71,8,3602},{71,8,3600},{2,21,384},{2,21,384}},
		{{79,8,3611},{79,8,3608},{0,69,448},{0,69,448}},
		{{87,8,3611},{87,8,3608},{0,23,384},{0,23,384}},
		{{95,8,3611},{95,8,3608},{1,5,448},{1,5,448}},
		{{104,8,3611},{104,8,3608},{0,88,448},{0,88,448}},
		{{112,8,3611},{112,8,3608},{0,72,448},{0,72,448}},
		{{120,8,3611},{121,8,3608},{36,21,458},{36,21,456}},
		{{133,47,3091},{129,8,3608},{44,21,458},{44,21,456}},
		{{142,47,3091},{138,8,3608},{53,21,459},{53,21,456}},
		{{98,12,3850},{98,12,3848},{61,21,459},{61,21,456}},
		{{106,12,3850},{106,12,3848},{10,92,480},{69,21,456}},
		{{114,12,3851},{114,12,3848},{18,92,480},{77,21,456}},
		{{123,12,3851},{123,12,3848},{3,44,488},{86,21,456}},
		{{95,12,3906},{95,12,3904},{11,44,488},{94,21,456}},
		{{103,12,3906},{103,12,3904},{19,44,488},{102,21,456}},
		{{111,12,3907},{111,12,3904},{27,44,489},{110,21,456}},
		{{120,12,3907},{120,12,3904},{36,44,489},{119,21,456}},
		{{128,12,3907},{128,12,3904},{44,44,489},{127,21,456}},
		{{136,12,3907},{136,12,3904},{52,44,489},{135,21,456}},
		{{144,12,3907},{144,12,3904},{60,44,490},{144,21,456}},
		{{153,12,3907},{153,12,3904},{69,44,490},{153,21,456}},
		{{161,12,3395},{149,188,3968},{77,44,490},{161,21,456}},
		{{169,12,3395},{199,21,3928},{85,44,490},{169,21,456}},
		{{113,95,4001},{202,69,3992},{125,8,483},{177,21,456}},
		{{122,95,4001},{201,21,3984},{134,8,483},{186,21,456}},
		{{143,8,4067},{209,21,3984},{142,8,483},{194,21,456}},
		{{151,8,4067},{47,15,4080},{151,8,483},{47,15,496}},
		{{159,8,4067},{55,15,4080},{159,8,483},{55,15,496}},
		{{168,8,4067},{64,15,4080},{168,8,483},{64,15,496}},
		{{160,40,4075},{72,15,4080},{160,40,491},{72,15,496}},
		{{168,40,4075},{80,15,4080},{168,40,491},{80,15,496}},
		{{144,8,4082},{88,15,4080},{144,8,498},{88,15,496}},
	};

	static void convert_etc1s_to_etc2_eac_r11(eac_block* pDst_block, const endpoint* pEndpoints, const selector* pSelector)
	{
		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r;
			decoder_etc_block::get_block_color5_r(base_color, inten_table, low_selector, r);

			// Constant alpha block
			// Select table 13, use selector 4 (0), set multiplier to 1 and base color r
			pDst_block->m_base = r;
			pDst_block->m_table = 13;
			pDst_block->m_multiplier = 1;

			// selectors are all 4's
			static const uint8_t s_etc2_eac_r11_sel4[6] = { 0x92, 0x49, 0x24, 0x92, 0x49, 0x24 };
			memcpy(pDst_block->m_selectors, s_etc2_eac_r11_sel4, sizeof(s_etc2_eac_r11_sel4));

			return;
		}

		uint32_t selector_range_table = 0;
		for (selector_range_table = 0; selector_range_table < NUM_ETC2_EAC_SELECTOR_RANGES; selector_range_table++)
			if ((low_selector == s_etc2_eac_selector_ranges[selector_range_table].m_low) && (high_selector == s_etc2_eac_selector_ranges[selector_range_table].m_high))
				break;
		if (selector_range_table >= NUM_ETC2_EAC_SELECTOR_RANGES)
			selector_range_table = 0;

		const etc1_g_to_eac_conversion* pTable_entry = &s_etc1_g_to_etc2_r11[base_color.r + inten_table * 32][selector_range_table];

		pDst_block->m_base = pTable_entry->m_base;
		pDst_block->m_table = pTable_entry->m_table_mul >> 4;
		pDst_block->m_multiplier = pTable_entry->m_table_mul & 15;

		uint64_t selector_bits = 0;

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s = pSelector->get_selector(x, y);

				uint32_t ds = (pTable_entry->m_trans >> (s * 3)) & 7;

				const uint32_t dst_ofs = 45 - (y + x * 4) * 3;
				selector_bits |= (static_cast<uint64_t>(ds) << dst_ofs);
			}
		}

		pDst_block->set_selector_bits(selector_bits);
	}
#endif // BASISD_SUPPORT_ETC2_EAC_RG11

	// ASTC
	struct etc1_to_astc_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};

#if BASISD_SUPPORT_ASTC
	static dxt_selector_range g_etc1_to_astc_selector_ranges[] =
	{
		{ 0, 3 },

		{ 1, 3 },
		{ 0, 2 },

		{ 1, 2 },

		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1_TO_ASTC_SELECTOR_RANGES = sizeof(g_etc1_to_astc_selector_ranges) / sizeof(g_etc1_to_astc_selector_ranges[0]);

	static uint32_t g_etc1_to_astc_selector_range_index[4][4];

	const uint32_t NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1_to_astc_selector_mappings[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 },
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};

	static const etc1_to_astc_solution g_etc1_to_astc[32 * 8 * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS * NUM_ETC1_TO_ASTC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_astc.inc"
	};

	// The best selector mapping to use given a base base+inten table and used selector range for converting grayscale data.
	static uint8_t g_etc1_to_astc_best_grayscale_mapping[32][8][NUM_ETC1_TO_ASTC_SELECTOR_RANGES];
	
#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
	static const etc1_to_astc_solution g_etc1_to_astc_0_255[32 * 8 * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS * NUM_ETC1_TO_ASTC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_astc_0_255.inc"
	};
	static uint8_t g_etc1_to_astc_best_grayscale_mapping_0_255[32][8][NUM_ETC1_TO_ASTC_SELECTOR_RANGES];
#endif

	static uint32_t g_ise_to_unquant[48];

#if BASISD_WRITE_NEW_ASTC_TABLES
	static void create_etc1_to_astc_conversion_table_0_47()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_astc.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_astc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_astc_selector_ranges[sr].m_high;

					uint32_t mapping_best_low[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint32_t mapping_best_high[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t mapping_best_err[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t highest_best_err = 0;

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 47; hi++)
						{
							for (uint32_t lo = 0; lo <= 47; lo++)
							{
								uint32_t colors[4];

								for (uint32_t s = 0; s < 4; s++)
								{
									uint32_t s_scaled = s | (s << 2) | (s << 4);
									if (s_scaled > 32)
										s_scaled++;

									uint32_t c0 = g_ise_to_unquant[lo] | (g_ise_to_unquant[lo] << 8);
									uint32_t c1 = g_ise_to_unquant[hi] | (g_ise_to_unquant[hi] << 8);
									colors[s] = ((c0 * (64 - s_scaled) + c1 * s_scaled + 32) / 64) >> 8;
								}

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_astc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 8;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						mapping_best_low[m] = best_lo;
						mapping_best_high[m] = best_hi;
						mapping_best_err[m] = best_err;
						highest_best_err = basisu::maximum(highest_best_err, best_err);
												
					} // m

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint64_t err = mapping_best_err[m];

						err = basisu::minimum<uint64_t>(err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", mapping_best_low[m], mapping_best_high[m], (uint32_t)err);

						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m

				} // sr
			} // g
		} // inten

		fclose(pFile);
	}

	static void create_etc1_to_astc_conversion_table_0_255()
	{
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_astc_0_255.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1_to_astc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1_to_astc_selector_ranges[sr].m_high;

					uint32_t mapping_best_low[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint32_t mapping_best_high[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t mapping_best_err[NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
					uint64_t highest_best_err = 0;

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 255; hi++)
						{
							for (uint32_t lo = 0; lo <= 255; lo++)
							{
								uint32_t colors[4];

								for (uint32_t s = 0; s < 4; s++)
								{
									uint32_t s_scaled = s | (s << 2) | (s << 4);
									if (s_scaled > 32)
										s_scaled++;

									uint32_t c0 = lo | (lo << 8);
									uint32_t c1 = hi | (hi << 8);
									colors[s] = ((c0 * (64 - s_scaled) + c1 * s_scaled + 32) / 64) >> 8;
								}

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1_to_astc_selector_mappings[m][s]];

									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									int err_scale = 1;
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 8;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						mapping_best_low[m] = best_lo;
						mapping_best_high[m] = best_hi;
						mapping_best_err[m] = best_err;
						highest_best_err = basisu::maximum(highest_best_err, best_err);
					} // m

					for (uint32_t m = 0; m < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; m++)
					{
						uint64_t err = mapping_best_err[m];

						err = basisu::minimum<uint64_t>(err, 0xFFFF);
						
						fprintf(pFile, "{%u,%u,%u},", mapping_best_low[m], mapping_best_high[m], (uint32_t)err);
						
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m

				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif

#endif

#if BASISD_SUPPORT_UASTC || BASISD_SUPPORT_ASTC
	// Table encodes 5 trits to 8 output bits. 3^5 entries.
	// Inverse of the trit bit manipulation process in https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-integer-sequence-encoding
	static const uint8_t g_astc_trit_encode[243] = { 0, 1, 2, 4, 5, 6, 8, 9, 10, 16, 17, 18, 20, 21, 22, 24, 25, 26, 3, 7, 11, 19, 23, 27, 12, 13, 14, 32, 33, 34, 36, 37, 38, 40, 41, 42, 48, 49, 50, 52, 53, 54, 56, 57, 58, 35, 39,
		43, 51, 55, 59, 44, 45, 46, 64, 65, 66, 68, 69, 70, 72, 73, 74, 80, 81, 82, 84, 85, 86, 88, 89, 90, 67, 71, 75, 83, 87, 91, 76, 77, 78, 128, 129, 130, 132, 133, 134, 136, 137, 138, 144, 145, 146, 148, 149, 150, 152, 153, 154,
		131, 135, 139, 147, 151, 155, 140, 141, 142, 160, 161, 162, 164, 165, 166, 168, 169, 170, 176, 177, 178, 180, 181, 182, 184, 185, 186, 163, 167, 171, 179, 183, 187, 172, 173, 174, 192, 193, 194, 196, 197, 198, 200, 201, 202,
		208, 209, 210, 212, 213, 214, 216, 217, 218, 195, 199, 203, 211, 215, 219, 204, 205, 206, 96, 97, 98, 100, 101, 102, 104, 105, 106, 112, 113, 114, 116, 117, 118, 120, 121, 122, 99, 103, 107, 115, 119, 123, 108, 109, 110, 224,
		225, 226, 228, 229, 230, 232, 233, 234, 240, 241, 242, 244, 245, 246, 248, 249, 250, 227, 231, 235, 243, 247, 251, 236, 237, 238, 28, 29, 30, 60, 61, 62, 92, 93, 94, 156, 157, 158, 188, 189, 190, 220, 221, 222, 31, 63, 95, 159,
		191, 223, 124, 125, 126 };

	// Extracts bits [low,high]
	static inline uint32_t astc_extract_bits(uint32_t bits, int low, int high)
	{
		return (bits >> low) & ((1 << (high - low + 1)) - 1);
	}

	// Writes bits to output in an endian safe way
	static inline void astc_set_bits(uint32_t* pOutput, int& bit_pos, uint32_t value, uint32_t total_bits)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		while (total_bits)
		{
			const uint32_t bits_to_write = basisu::minimum<int>(total_bits, 8 - (bit_pos & 7));

			pBytes[bit_pos >> 3] |= static_cast<uint8_t>(value << (bit_pos & 7));

			bit_pos += bits_to_write;
			total_bits -= bits_to_write;
			value >>= bits_to_write;
		}
	}

	// Encodes 5 values to output, usable for any range that uses trits and bits
	static void astc_encode_trits(uint32_t* pOutput, const uint8_t* pValues, int& bit_pos, int n)
	{
		// First extract the trits and the bits from the 5 input values
		int trits = 0, bits[5];
		const uint32_t bit_mask = (1 << n) - 1;
		for (int i = 0; i < 5; i++)
		{
			static const int s_muls[5] = { 1, 3, 9, 27, 81 };

			const int t = pValues[i] >> n;

			trits += t * s_muls[i];
			bits[i] = pValues[i] & bit_mask;
		}

		// Encode the trits, by inverting the bit manipulations done by the decoder, converting 5 trits into 8-bits.
		// See https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-integer-sequence-encoding

		assert(trits < 243);
		const int T = g_astc_trit_encode[trits];

		// Now interleave the 8 encoded trit bits with the bits to form the encoded output. See table 94.
		astc_set_bits(pOutput, bit_pos, bits[0] | (astc_extract_bits(T, 0, 1) << n) | (bits[1] << (2 + n)), n * 2 + 2);

		astc_set_bits(pOutput, bit_pos, astc_extract_bits(T, 2, 3) | (bits[2] << 2) | (astc_extract_bits(T, 4, 4) << (2 + n)) | (bits[3] << (3 + n)) | (astc_extract_bits(T, 5, 6) << (3 + n * 2)) |
			(bits[4] << (5 + n * 2)) | (astc_extract_bits(T, 7, 7) << (5 + n * 3)), n * 3 + 6);
	}
#endif // #if BASISD_SUPPORT_UASTC || BASISD_SUPPORT_ASTC

#if BASISD_SUPPORT_ASTC
	struct astc_block_params
	{
		// 2 groups of 5, but only a max of 8 are used (RRGGBBAA00)
		uint8_t m_endpoints[10]; 
		uint8_t m_weights[32];
	};
	
	// Packs a single format ASTC block using Color Endpoint Mode 12 (LDR RGBA direct), endpoint BISE range 13, 2-bit weights (range 2). 
	// We're always going to output blocks containing alpha, even if the input doesn't have alpha, for simplicity.
	// Each block always has 4x4 weights, uses range 13 BISE encoding on the endpoints (0-47), and each weight ranges from 0-3. This encoding should be roughly equal in quality vs. BC1 for color.
	// 8 total endpoints, stored as RGBA LH LH LH LH order, each ranging from 0-47. 
	// Note the input [0,47] endpoint values are not linear - they are encoded as outlined in the ASTC spec:
	// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-endpoint-unquantization
	// 32 total weights, stored as 16 CA CA, each ranging from 0-3.
	static void astc_pack_block_cem_12_weight_range2(uint32_t *pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x42; pBytes[1] = 0x84; pBytes[2] = 0x01; pBytes[3] = 0x00;
		pBytes[4] = 0x00; pBytes[5] = 0x00; pBytes[6] = 0x00; pBytes[7] = 0xc0;

		pOutput[2] = 0;
		pOutput[3] = 0;

		// Pack 8 endpoints (each ranging between [0,47]) using BISE starting at bit 17
		int bit_pos = 17;
		astc_encode_trits(pOutput, pBlock->m_endpoints, bit_pos, 4);
		astc_encode_trits(pOutput, pBlock->m_endpoints + 5, bit_pos, 4);

		// Pack 32 2-bit weights, which are stored from the top down into the block in opposite bit order.
				
		for (uint32_t i = 0; i < 32; i++)
		{
			static const uint8_t s_reverse_bits[4] = { 0, 2, 1, 3 };
			const uint32_t ofs = 126 - (i * 2);
			pBytes[ofs >> 3] |= (s_reverse_bits[pBlock->m_weights[i]] << (ofs & 7));
		}
	}

	// CEM mode 12 (LDR RGBA Direct), 8-bit endpoints, 1-bit weights 
	// This ASTC mode is basically block truncation coding (BTC) using 1-bit weights and 8-bit/component endpoints - very convenient.
	static void astc_pack_block_cem_12_weight_range0(uint32_t* pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x41; pBytes[1] = 0x84; pBytes[2] = 0x01; pBytes[3] = 0x00;
		pOutput[1] = 0;
		pBytes[8] = 0x00; pBytes[9] = 0x00; pBytes[10] = 0x00; pBytes[11] = 0xc0;
		pOutput[3] = 0;

		// Pack 8 endpoints (each ranging between [0,255]) as 8-bits starting at bit 17
		int bit_pos = 17;
		for (uint32_t i = 0; i < 8; i++)
			astc_set_bits(pOutput, bit_pos, pBlock->m_endpoints[i], 8);

		// Pack 32 1-bit weights, which are stored from the top down into the block in opposite bit order.
		for (uint32_t i = 0; i < 32; i++)
		{
			const uint32_t ofs = 127 - i;
			pBytes[ofs >> 3] |= (pBlock->m_weights[i] << (ofs & 7));
		}
	}

#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
	// Optional 8-bit endpoint packing functions.

	// CEM mode 4 (LDR Luminance+Alpha Direct), 8-bit endpoints, 2 bit weights
	static void astc_pack_block_cem_4_weight_range2(uint32_t* pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x42; pBytes[1] = 0x84; pBytes[2] = 0x00; pBytes[3] = 0x00;
		pBytes[4] = 0x00; pBytes[5] = 0x00; pBytes[6] = 0x00; pBytes[7] = 0xc0;
		
		pOutput[2] = 0;
		pOutput[3] = 0;

		// Pack 4 endpoints (each ranging between [0,255]) as 8-bits starting at bit 17
		int bit_pos = 17;
		for (uint32_t i = 0; i < 4; i++)
			astc_set_bits(pOutput, bit_pos, pBlock->m_endpoints[i], 8);

		// Pack 32 2-bit weights, which are stored from the top down into the block in opposite bit order.
		for (uint32_t i = 0; i < 32; i++)
		{
			static const uint8_t s_reverse_bits[4] = { 0, 2, 1, 3 };
			const uint32_t ofs = 126 - (i * 2);
			pBytes[ofs >> 3] |= (s_reverse_bits[pBlock->m_weights[i]] << (ofs & 7));
		}
	}

	// CEM mode 8 (LDR RGB Direct), 8-bit endpoints, 2 bit weights
	static void astc_pack_block_cem_8_weight_range2(uint32_t* pOutput, const astc_block_params* pBlock)
	{
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pOutput);

		// Write constant block mode, color component selector, number of partitions, color endpoint mode
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#_block_mode
		pBytes[0] = 0x42; pBytes[1] = 0x00; pBytes[2] = 0x01; pBytes[3] = 0x00;
		
		pOutput[1] = 0;
		pOutput[2] = 0;
		pOutput[3] = 0;

		// Pack 6 endpoints (each ranging between [0,255]) as 8-bits starting at bit 17
		int bit_pos = 17;
		for (uint32_t i = 0; i < 6; i++)
			astc_set_bits(pOutput, bit_pos, pBlock->m_endpoints[i], 8);

		// Pack 16 2-bit weights, which are stored from the top down into the block in opposite bit order.
		for (uint32_t i = 0; i < 16; i++)
		{
			static const uint8_t s_reverse_bits[4] = { 0, 2, 1, 3 };
			const uint32_t ofs = 126 - (i * 2);
			pBytes[ofs >> 3] |= (s_reverse_bits[pBlock->m_weights[i]] << (ofs & 7));
		}
	}
#endif

	// Optimal quantized [0,47] entry to use given [0,255] input
	static uint8_t g_astc_single_color_encoding_0[256];

	// Optimal quantized [0,47] low/high values given [0,255] input assuming a selector of 1
	static struct
	{
		uint8_t m_lo, m_hi;
	} g_astc_single_color_encoding_1[256];
		
	static void transcoder_init_astc()
	{
		for (uint32_t base_color = 0; base_color < 32; base_color++)
		{
			for (uint32_t inten_table = 0; inten_table < 8; inten_table++)
			{
				for (uint32_t range_index = 0; range_index < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; range_index++)
				{
					const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc[(inten_table * 32 + base_color) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + range_index * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

					uint32_t best_mapping = 0;
					uint32_t best_err = UINT32_MAX;
					for (uint32_t mapping_index = 0; mapping_index < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; mapping_index++)
					{
						if (pTable_g[mapping_index].m_err < best_err)
						{
							best_err = pTable_g[mapping_index].m_err;
							best_mapping = mapping_index;
						}
					}

					g_etc1_to_astc_best_grayscale_mapping[base_color][inten_table][range_index] = static_cast<uint8_t>(best_mapping);
				}
			}
		}

#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
		for (uint32_t base_color = 0; base_color < 32; base_color++)
		{
			for (uint32_t inten_table = 0; inten_table < 8; inten_table++)
			{
				for (uint32_t range_index = 0; range_index < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; range_index++)
				{
					const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + range_index * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

					uint32_t best_mapping = 0;
					uint32_t best_err = UINT32_MAX;
					for (uint32_t mapping_index = 0; mapping_index < NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS; mapping_index++)
					{
						if (pTable_g[mapping_index].m_err < best_err)
						{
							best_err = pTable_g[mapping_index].m_err;
							best_mapping = mapping_index;
						}
					}

					g_etc1_to_astc_best_grayscale_mapping_0_255[base_color][inten_table][range_index] = static_cast<uint8_t>(best_mapping);
				}
			}
		}
#endif

		for (uint32_t i = 0; i < NUM_ETC1_TO_ASTC_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1_to_astc_selector_ranges[i].m_low;
			uint32_t h = g_etc1_to_astc_selector_ranges[i].m_high;
			g_etc1_to_astc_selector_range_index[l][h] = i;
		}

		// Endpoint dequantization, see:
		// https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-endpoint-unquantization
		for (uint32_t trit = 0; trit < 3; trit++)
		{
			for (uint32_t bit = 0; bit < 16; bit++)
			{
				const uint32_t A = (bit & 1) ? 511 : 0;
				const uint32_t B = (bit >> 1) | ((bit >> 1) << 6);
				const uint32_t C = 22;
				const uint32_t D = trit;

				uint32_t unq = D * C + B;
				unq = unq ^ A;
				unq = (A & 0x80) | (unq >> 2);

				g_ise_to_unquant[bit | (trit << 4)] = unq;
			}
		}
				
		// Compute table used for optimal single color encoding.
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = INT_MAX;

			for (int lo = 0; lo < 48; lo++)
			{
				for (int hi = 0; hi < 48; hi++)
				{
					const int lo_v = g_ise_to_unquant[lo];
					const int hi_v = g_ise_to_unquant[hi];

					int l = lo_v | (lo_v << 8);
					int h = hi_v | (hi_v << 8);
										
					int v = ((l * (64 - 21) + (h * 21) + 32) / 64) >> 8;
					
					int e = abs(v - i);

					if (e < lowest_e)
					{
						g_astc_single_color_encoding_1[i].m_hi = static_cast<uint8_t>(hi);
						g_astc_single_color_encoding_1[i].m_lo = static_cast<uint8_t>(lo);

						lowest_e = e;
					}

				} // hi
			} // lo
		}

		for (int i = 0; i < 256; i++)
		{
			int lowest_e = INT_MAX;

			for (int lo = 0; lo < 48; lo++)
			{
				const int lo_v = g_ise_to_unquant[lo];
				
				int e = abs(lo_v - i);

				if (e < lowest_e)
				{
					g_astc_single_color_encoding_0[i] = static_cast<uint8_t>(lo);

					lowest_e = e;
				}
			} // lo
		}
	}

	// Converts opaque or color+alpha ETC1S block to ASTC 4x4.
	// This function tries to use the best ASTC mode given the block's actual contents.
	static void convert_etc1s_to_astc_4x4(void* pDst_block, const endpoint* pEndpoints, const selector* pSelector, 
		bool transcode_alpha, const endpoint *pEndpoint_codebook, const selector *pSelector_codebook)
	{
		astc_block_params blk;

		blk.m_endpoints[8] = 0;
		blk.m_endpoints[9] = 0;

		int constant_alpha_val = 255;
		int num_unique_alpha_selectors = 1;

		if (transcode_alpha)
		{
			const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

			num_unique_alpha_selectors = alpha_selectors.m_num_unique_selectors;

			if (num_unique_alpha_selectors == 1)
			{
				const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];

				const color32& alpha_base_color = alpha_endpoint.m_color5;
				const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

				int alpha_block_colors[4];
				decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

				constant_alpha_val = alpha_block_colors[alpha_selectors.m_lo_selector];
			}
		}

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		// Handle solid color or BTC blocks, which can always be encoded from ETC1S to ASTC losslessly.
		if ((pSelector->m_num_unique_selectors == 1) && (num_unique_alpha_selectors == 1))
		{
			// Both color and alpha are constant, write a solid color block and exit.
			// See https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-void-extent-blocks
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);
						
			uint32_t* pOutput = static_cast<uint32_t*>(pDst_block);
			uint8_t* pBytes = reinterpret_cast<uint8_t*>(pDst_block);

			pBytes[0] = 0xfc; pBytes[1] = 0xfd; pBytes[2] = 0xff; pBytes[3] = 0xff;

			pOutput[1] = 0xffffffff;
			pOutput[2] = 0;
			pOutput[3] = 0;

			int bit_pos = 64;
			astc_set_bits(pOutput, bit_pos, r | (r << 8), 16);
			astc_set_bits(pOutput, bit_pos, g | (g << 8), 16);
			astc_set_bits(pOutput, bit_pos, b | (b << 8), 16);
			astc_set_bits(pOutput, bit_pos, constant_alpha_val | (constant_alpha_val << 8), 16);

			return;
		}
		else if ((pSelector->m_num_unique_selectors <= 2) && (num_unique_alpha_selectors <= 2))
		{
			// Both color and alpha use <= 2 unique selectors each. 
			// Use block truncation coding, which is lossless with ASTC (8-bit endpoints, 1-bit weights).
			color32 block_colors[4];
			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			blk.m_endpoints[0] = block_colors[low_selector].r;
			blk.m_endpoints[2] = block_colors[low_selector].g;
			blk.m_endpoints[4] = block_colors[low_selector].b;

			blk.m_endpoints[1] = block_colors[high_selector].r;
			blk.m_endpoints[3] = block_colors[high_selector].g;
			blk.m_endpoints[5] = block_colors[high_selector].b;

			int s0 = blk.m_endpoints[0] + blk.m_endpoints[2] + blk.m_endpoints[4];
			int s1 = blk.m_endpoints[1] + blk.m_endpoints[3] + blk.m_endpoints[5];
			bool invert = false;
			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			if (transcode_alpha)
			{
				const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];
				const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

				const color32& alpha_base_color = alpha_endpoint.m_color5;
				const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

				const uint32_t alpha_low_selector = alpha_selectors.m_lo_selector;
				const uint32_t alpha_high_selector = alpha_selectors.m_hi_selector;

				int alpha_block_colors[4];
				decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

				blk.m_endpoints[6] = static_cast<uint8_t>(alpha_block_colors[alpha_low_selector]);
				blk.m_endpoints[7] = static_cast<uint8_t>(alpha_block_colors[alpha_high_selector]);

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = alpha_selectors.get_selector(x, y);
						s = (s == alpha_high_selector) ? 1 : 0;
												
						blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(s);
					} // x
				} // y
			}
			else
			{
				blk.m_endpoints[6] = 255;
				blk.m_endpoints[7] = 255;

				for (uint32_t i = 0; i < 16; i++)
					blk.m_weights[i * 2 + 1] = 0;
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);

					s = (s == high_selector) ? 1 : 0;

					if (invert)
						s = 1 - s;

					blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(s);
				} // x
			} // y

			astc_pack_block_cem_12_weight_range0(reinterpret_cast<uint32_t*>(pDst_block), &blk);

			return;
		}
				
		// Either alpha and/or color use > 2 unique selectors each, so we must do something more complex.
				
#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY
		// The optional higher quality modes use 8-bits endpoints vs. [0,47] endpoints.
		
		// If the block's base color is grayscale, all pixels are grayscale, so encode the block as Luminance+Alpha.
		if ((base_color.r == base_color.g) && (base_color.r == base_color.b))
		{
			if (transcode_alpha)
			{
				const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];
				const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

				const color32& alpha_base_color = alpha_endpoint.m_color5;
				const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

				const uint32_t alpha_low_selector = alpha_selectors.m_lo_selector;
				const uint32_t alpha_high_selector = alpha_selectors.m_hi_selector;

				if (num_unique_alpha_selectors <= 2)
				{
					// Simple alpha block with only 1 or 2 unique values, so use BTC. This is lossless.
					int alpha_block_colors[4];
					decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

					blk.m_endpoints[2] = static_cast<uint8_t>(alpha_block_colors[alpha_low_selector]);
					blk.m_endpoints[3] = static_cast<uint8_t>(alpha_block_colors[alpha_high_selector]);

					for (uint32_t i = 0; i < 16; i++)
					{
						uint32_t s = alpha_selectors.get_selector(i & 3, i >> 2);
						blk.m_weights[i * 2 + 1] = (s == alpha_high_selector) ? 3 : 0;
					}
				}
				else
				{
					// Convert ETC1S alpha
					const uint32_t alpha_selector_range_table = g_etc1_to_astc_selector_range_index[alpha_low_selector][alpha_high_selector];
										
					//[32][8][RANGES][MAPPING]
					const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(alpha_inten_table * 32 + alpha_base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + alpha_selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

					const uint32_t best_mapping = g_etc1_to_astc_best_grayscale_mapping_0_255[alpha_base_color.g][alpha_inten_table][alpha_selector_range_table];

					blk.m_endpoints[2] = pTable_g[best_mapping].m_lo;
					blk.m_endpoints[3] = pTable_g[best_mapping].m_hi;
										
					const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

					for (uint32_t y = 0; y < 4; y++)
					{
						for (uint32_t x = 0; x < 4; x++)
						{
							uint32_t s = alpha_selectors.get_selector(x, y);
							uint32_t as = pSelectors_xlat[s];

							blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(as);
						} // x
					} // y
				}
			}
			else
			{
				// No alpha slice - set output alpha to all 255's
				blk.m_endpoints[2] = 255;
				blk.m_endpoints[3] = 255;

				for (uint32_t i = 0; i < 16; i++)
					blk.m_weights[i * 2 + 1] = 0;
			}

			if (pSelector->m_num_unique_selectors <= 2)
			{
				// Simple color block with only 1 or 2 unique values, so use BTC. This is lossless.
				int block_colors[4];
				decoder_etc_block::get_block_colors5_g(block_colors, base_color, inten_table);

				blk.m_endpoints[0] = static_cast<uint8_t>(block_colors[low_selector]);
				blk.m_endpoints[1] = static_cast<uint8_t>(block_colors[high_selector]);

				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t s = pSelector->get_selector(i & 3, i >> 2);
					blk.m_weights[i * 2] = (s == high_selector) ? 3 : 0;
				}
			}
			else
			{
				// Convert ETC1S alpha
				const uint32_t selector_range_table = g_etc1_to_astc_selector_range_index[low_selector][high_selector];
								
				//[32][8][RANGES][MAPPING]
				const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
								
				const uint32_t best_mapping = g_etc1_to_astc_best_grayscale_mapping_0_255[base_color.g][inten_table][selector_range_table];

				blk.m_endpoints[0] = pTable_g[best_mapping].m_lo;
				blk.m_endpoints[1] = pTable_g[best_mapping].m_hi;

				const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = pSelector->get_selector(x, y);
						uint32_t as = pSelectors_xlat[s];

						blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(as);
					} // x
				} // y
			}

			astc_pack_block_cem_4_weight_range2(reinterpret_cast<uint32_t*>(pDst_block), &blk);
			return;
		}

		// The block isn't grayscale and it uses > 2 unique selectors for opaque and/or alpha.
		// Check for fully opaque blocks, if so use 8-bit endpoints for slightly higher opaque quality (higher than BC1, but lower than BC7 mode 6 opaque).
		if ((num_unique_alpha_selectors == 1) && (constant_alpha_val == 255))
		{
			// Convert ETC1S color
			const uint32_t selector_range_table = g_etc1_to_astc_selector_range_index[low_selector][high_selector];

			//[32][8][RANGES][MAPPING]
			const etc1_to_astc_solution* pTable_r = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.r) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_b = &g_etc1_to_astc_0_255[(inten_table * 32 + base_color.b) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

			uint32_t best_err = UINT_MAX;
			uint32_t best_mapping = 0;

			assert(NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
			DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
			DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

			blk.m_endpoints[0] = pTable_r[best_mapping].m_lo;
			blk.m_endpoints[1] = pTable_r[best_mapping].m_hi;

			blk.m_endpoints[2] = pTable_g[best_mapping].m_lo;
			blk.m_endpoints[3] = pTable_g[best_mapping].m_hi;

			blk.m_endpoints[4] = pTable_b[best_mapping].m_lo;
			blk.m_endpoints[5] = pTable_b[best_mapping].m_hi;

			int s0 = blk.m_endpoints[0] + blk.m_endpoints[2] + blk.m_endpoints[4];
			int s1 = blk.m_endpoints[1] + blk.m_endpoints[3] + blk.m_endpoints[5];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t as = pSelectors_xlat[s];
					if (invert)
						as = 3 - as;

					blk.m_weights[x + y * 4] = static_cast<uint8_t>(as);
				} // x
			} // y

			// Now pack to ASTC
			astc_pack_block_cem_8_weight_range2(reinterpret_cast<uint32_t*>(pDst_block), &blk);
			return;
		}
#endif //#if BASISD_SUPPORT_ASTC_HIGHER_OPAQUE_QUALITY

		// Nothing else worked, so fall back to CEM Mode 12 (LDR RGBA Direct), [0,47] endpoints, weight range 2 (2-bit weights), dual planes.
		// This mode can handle everything, but at slightly less quality than BC1.
		if (transcode_alpha)
		{
			const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pDst_block)[0]];
			const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pDst_block)[1]];

			const color32& alpha_base_color = alpha_endpoint.m_color5;
			const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

			const uint32_t alpha_low_selector = alpha_selectors.m_lo_selector;
			const uint32_t alpha_high_selector = alpha_selectors.m_hi_selector;

			if (alpha_low_selector == alpha_high_selector)
			{
				// Solid alpha block - use precomputed tables.
				int alpha_block_colors[4];
				decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

				const uint32_t g = alpha_block_colors[alpha_low_selector];

				blk.m_endpoints[6] = g_astc_single_color_encoding_1[g].m_lo;
				blk.m_endpoints[7] = g_astc_single_color_encoding_1[g].m_hi;

				for (uint32_t i = 0; i < 16; i++)
					blk.m_weights[i * 2 + 1] = 1;
			}
			else if ((alpha_inten_table >= 7) && (alpha_selectors.m_num_unique_selectors == 2) && (alpha_low_selector == 0) && (alpha_high_selector == 3))
			{
				// Handle outlier case where only the two outer colors are used with inten table 7.
				color32 alpha_block_colors[4];

				decoder_etc_block::get_block_colors5(alpha_block_colors, alpha_base_color, alpha_inten_table);

				const uint32_t g0 = alpha_block_colors[0].g;
				const uint32_t g1 = alpha_block_colors[3].g;

				blk.m_endpoints[6] = g_astc_single_color_encoding_0[g0];
				blk.m_endpoints[7] = g_astc_single_color_encoding_0[g1];

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = alpha_selectors.get_selector(x, y);
						uint32_t as = (s == alpha_high_selector) ? 3 : 0;

						blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(as);
					} // x
				} // y
			}
			else
			{
				// Convert ETC1S alpha
				const uint32_t alpha_selector_range_table = g_etc1_to_astc_selector_range_index[alpha_low_selector][alpha_high_selector];
								
				//[32][8][RANGES][MAPPING]
				const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc[(alpha_inten_table * 32 + alpha_base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + alpha_selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

				const uint32_t best_mapping = g_etc1_to_astc_best_grayscale_mapping[alpha_base_color.g][alpha_inten_table][alpha_selector_range_table];

				blk.m_endpoints[6] = pTable_g[best_mapping].m_lo;
				blk.m_endpoints[7] = pTable_g[best_mapping].m_hi;

				const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

				for (uint32_t y = 0; y < 4; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t s = alpha_selectors.get_selector(x, y);
						uint32_t as = pSelectors_xlat[s];

						blk.m_weights[(x + y * 4) * 2 + 1] = static_cast<uint8_t>(as);
					} // x
				} // y
			}
		}
		else
		{
			// No alpha slice - set output alpha to all 255's
			// 1 is 255 when dequantized
			blk.m_endpoints[6] = 1;
			blk.m_endpoints[7] = 1;

			for (uint32_t i = 0; i < 16; i++)
				blk.m_weights[i * 2 + 1] = 0;
		}

		if (low_selector == high_selector)
		{
			// Solid color block - use precomputed tables of optimal endpoints assuming selector weights are all 1.
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r = block_colors[low_selector].r;
			const uint32_t g = block_colors[low_selector].g;
			const uint32_t b = block_colors[low_selector].b;
						
			blk.m_endpoints[0] = g_astc_single_color_encoding_1[r].m_lo;
			blk.m_endpoints[1] = g_astc_single_color_encoding_1[r].m_hi;

			blk.m_endpoints[2] = g_astc_single_color_encoding_1[g].m_lo;
			blk.m_endpoints[3] = g_astc_single_color_encoding_1[g].m_hi;

			blk.m_endpoints[4] = g_astc_single_color_encoding_1[b].m_lo;
			blk.m_endpoints[5] = g_astc_single_color_encoding_1[b].m_hi;

			int s0 = g_ise_to_unquant[blk.m_endpoints[0]] + g_ise_to_unquant[blk.m_endpoints[2]] + g_ise_to_unquant[blk.m_endpoints[4]];
			int s1 = g_ise_to_unquant[blk.m_endpoints[1]] + g_ise_to_unquant[blk.m_endpoints[3]] + g_ise_to_unquant[blk.m_endpoints[5]];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			for (uint32_t i = 0; i < 16; i++)
				blk.m_weights[i * 2] = invert ? 2 : 1;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			// Handle outlier case where only the two outer colors are used with inten table 7.
			color32 block_colors[4];

			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			blk.m_endpoints[0] = g_astc_single_color_encoding_0[r0];
			blk.m_endpoints[1] = g_astc_single_color_encoding_0[r1];

			blk.m_endpoints[2] = g_astc_single_color_encoding_0[g0];
			blk.m_endpoints[3] = g_astc_single_color_encoding_0[g1];

			blk.m_endpoints[4] = g_astc_single_color_encoding_0[b0];
			blk.m_endpoints[5] = g_astc_single_color_encoding_0[b1];

			int s0 = g_ise_to_unquant[blk.m_endpoints[0]] + g_ise_to_unquant[blk.m_endpoints[2]] + g_ise_to_unquant[blk.m_endpoints[4]];
			int s1 = g_ise_to_unquant[blk.m_endpoints[1]] + g_ise_to_unquant[blk.m_endpoints[3]] + g_ise_to_unquant[blk.m_endpoints[5]];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t as = (s == low_selector) ? 0 : 3;

					if (invert)
						as = 3 - as;

					blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(as);
				} // x
			} // y
		}
		else
		{
			// Convert ETC1S color
			const uint32_t selector_range_table = g_etc1_to_astc_selector_range_index[low_selector][high_selector];

			//[32][8][RANGES][MAPPING]
			const etc1_to_astc_solution* pTable_r = &g_etc1_to_astc[(inten_table * 32 + base_color.r) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_g = &g_etc1_to_astc[(inten_table * 32 + base_color.g) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];
			const etc1_to_astc_solution* pTable_b = &g_etc1_to_astc[(inten_table * 32 + base_color.b) * (NUM_ETC1_TO_ASTC_SELECTOR_RANGES * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS];

			uint32_t best_err = UINT_MAX;
			uint32_t best_mapping = 0;

			assert(NUM_ETC1_TO_ASTC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
			DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
			DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

			blk.m_endpoints[0] = pTable_r[best_mapping].m_lo;
			blk.m_endpoints[1] = pTable_r[best_mapping].m_hi;

			blk.m_endpoints[2] = pTable_g[best_mapping].m_lo;
			blk.m_endpoints[3] = pTable_g[best_mapping].m_hi;

			blk.m_endpoints[4] = pTable_b[best_mapping].m_lo;
			blk.m_endpoints[5] = pTable_b[best_mapping].m_hi;
						
			int s0 = g_ise_to_unquant[blk.m_endpoints[0]] + g_ise_to_unquant[blk.m_endpoints[2]] + g_ise_to_unquant[blk.m_endpoints[4]];
			int s1 = g_ise_to_unquant[blk.m_endpoints[1]] + g_ise_to_unquant[blk.m_endpoints[3]] + g_ise_to_unquant[blk.m_endpoints[5]];
			bool invert = false;

			if (s1 < s0)
			{
				std::swap(blk.m_endpoints[0], blk.m_endpoints[1]);
				std::swap(blk.m_endpoints[2], blk.m_endpoints[3]);
				std::swap(blk.m_endpoints[4], blk.m_endpoints[5]);
				invert = true;
			}

			const uint8_t* pSelectors_xlat = &g_etc1_to_astc_selector_mappings[best_mapping][0];

			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = pSelector->get_selector(x, y);
					uint32_t as = pSelectors_xlat[s];
					if (invert)
						as = 3 - as;

					blk.m_weights[(x + y * 4) * 2] = static_cast<uint8_t>(as);
				} // x
			} // y
		}

		// Now pack to ASTC
		astc_pack_block_cem_12_weight_range2(reinterpret_cast<uint32_t *>(pDst_block), &blk);
	}
#endif

#if BASISD_SUPPORT_ATC
	// ATC and PVRTC2 both use these tables.
	struct etc1s_to_atc_solution
	{
		uint8_t m_lo;
		uint8_t m_hi;
		uint16_t m_err;
	};

	static dxt_selector_range g_etc1s_to_atc_selector_ranges[] =
	{
		{ 0, 3 },
		{ 1, 3 },
		{ 0, 2 },
		{ 1, 2 },
		{ 2, 3 },
		{ 0, 1 },
	};

	const uint32_t NUM_ETC1S_TO_ATC_SELECTOR_RANGES = sizeof(g_etc1s_to_atc_selector_ranges) / sizeof(g_etc1s_to_atc_selector_ranges[0]);

	static uint32_t g_etc1s_to_atc_selector_range_index[4][4];

	const uint32_t NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS = 10;
	static const uint8_t g_etc1s_to_atc_selector_mappings[NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS][4] =
	{
		{ 0, 0, 1, 1 },
		{ 0, 0, 1, 2 },
		{ 0, 0, 1, 3 },
		{ 0, 0, 2, 3 },
		{ 0, 1, 1, 1 },
		{ 0, 1, 2, 2 },
		{ 0, 1, 2, 3 }, //6 - identity
		{ 0, 2, 3, 3 },
		{ 1, 2, 2, 2 },
		{ 1, 2, 3, 3 },
	};
	const uint32_t ATC_IDENTITY_SELECTOR_MAPPING_INDEX = 6;

#if BASISD_SUPPORT_PVRTC2
	static const etc1s_to_atc_solution g_etc1s_to_pvrtc2_45[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_pvrtc2_45.inc"
	};

#if 0
	static const etc1s_to_atc_solution g_etc1s_to_pvrtc2_alpha_33[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_pvrtc2_alpha_33.inc"
	};
#endif

#endif

	static const etc1s_to_atc_solution g_etc1s_to_atc_55[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_atc_55.inc"
	};

	static const etc1s_to_atc_solution g_etc1s_to_atc_56[32 * 8 * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS * NUM_ETC1S_TO_ATC_SELECTOR_RANGES] = {
#include "basisu_transcoder_tables_atc_56.inc"
	};

	struct atc_match_entry
	{
		uint8_t m_lo;
		uint8_t m_hi;
	};
	static atc_match_entry g_pvrtc2_match45_equals_1[256], g_atc_match55_equals_1[256], g_atc_match56_equals_1[256]; // selector 1
	static atc_match_entry g_pvrtc2_match4[256], g_atc_match5[256], g_atc_match6[256];

	static void prepare_atc_single_color_table(atc_match_entry* pTable, int size0, int size1, int sel)
	{
		for (int i = 0; i < 256; i++)
		{
			int lowest_e = 256;
			for (int lo = 0; lo < size0; lo++)
			{
				int lo_e = lo;
				if (size0 == 16)
				{
					lo_e = (lo_e << 1) | (lo_e >> 3);
					lo_e = (lo_e << 3) | (lo_e >> 2);
				}
				else if (size0 == 32)
					lo_e = (lo_e << 3) | (lo_e >> 2);
				else
					lo_e = (lo_e << 2) | (lo_e >> 4);

				for (int hi = 0; hi < size1; hi++)
				{
					int hi_e = hi;
					if (size1 == 16)
					{
						// This is only for PVRTC2 - expand to 5 then 8
						hi_e = (hi_e << 1) | (hi_e >> 3);
						hi_e = (hi_e << 3) | (hi_e >> 2);
					}
					else if (size1 == 32)
						hi_e = (hi_e << 3) | (hi_e >> 2);
					else
						hi_e = (hi_e << 2) | (hi_e >> 4);

					int e;

					if (sel == 1)
					{
						// Selector 1
						e = abs(((lo_e * 5 + hi_e * 3) / 8) - i);
					}
					else
					{
						assert(sel == 3);

						// Selector 3
						e = abs(hi_e - i);
					}

					if (e < lowest_e)
					{
						pTable[i].m_lo = static_cast<uint8_t>(lo);
						pTable[i].m_hi = static_cast<uint8_t>(hi);

						lowest_e = e;
					}

				} // hi
			} // lo
		} // i
	}

	static void transcoder_init_atc()
	{
		prepare_atc_single_color_table(g_pvrtc2_match45_equals_1, 16, 32, 1);
		prepare_atc_single_color_table(g_atc_match55_equals_1, 32, 32, 1); 
		prepare_atc_single_color_table(g_atc_match56_equals_1, 32, 64, 1); 

		prepare_atc_single_color_table(g_pvrtc2_match4, 1, 16, 3);
		prepare_atc_single_color_table(g_atc_match5, 1, 32, 3);
		prepare_atc_single_color_table(g_atc_match6, 1, 64, 3);

		for (uint32_t i = 0; i < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; i++)
		{
			uint32_t l = g_etc1s_to_atc_selector_ranges[i].m_low;
			uint32_t h = g_etc1s_to_atc_selector_ranges[i].m_high;
			g_etc1s_to_atc_selector_range_index[l][h] = i;
		}
	}

	struct atc_block
	{
		uint8_t m_lo[2];
		uint8_t m_hi[2];
		uint8_t m_sels[4];

		void set_low_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 32) && (b < 32));
			uint32_t x = (r << 10) | (g << 5) | b;
			m_lo[0] = x & 0xFF;
			m_lo[1] = (x >> 8) & 0xFF;
		}

		void set_high_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 64) && (b < 32));
			uint32_t x = (r << 11) | (g << 5) | b;
			m_hi[0] = x & 0xFF;
			m_hi[1] = (x >> 8) & 0xFF;
		}
	};

	static void convert_etc1s_to_atc(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		atc_block* pBlock = static_cast<atc_block*>(pDst);

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			pBlock->set_low_color(g_atc_match55_equals_1[r].m_lo, g_atc_match56_equals_1[g].m_lo, g_atc_match55_equals_1[b].m_lo);
			pBlock->set_high_color(g_atc_match55_equals_1[r].m_hi, g_atc_match56_equals_1[g].m_hi, g_atc_match55_equals_1[b].m_hi);
						
			pBlock->m_sels[0] = 0x55;
			pBlock->m_sels[1] = 0x55;
			pBlock->m_sels[2] = 0x55;
			pBlock->m_sels[3] = 0x55;

			return;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			color32 block_colors[4];
			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			pBlock->set_low_color(g_atc_match5[r0].m_hi, g_atc_match5[g0].m_hi, g_atc_match5[b0].m_hi);
			pBlock->set_high_color(g_atc_match5[r1].m_hi, g_atc_match6[g1].m_hi, g_atc_match5[b1].m_hi);

			pBlock->m_sels[0] = pSelector->m_selectors[0];
			pBlock->m_sels[1] = pSelector->m_selectors[1];
			pBlock->m_sels[2] = pSelector->m_selectors[2];
			pBlock->m_sels[3] = pSelector->m_selectors[3];

			return;
		}

		const uint32_t selector_range_table = g_etc1s_to_atc_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1s_to_atc_solution* pTable_r = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.r) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_g = &g_etc1s_to_atc_56[(inten_table * 32 + base_color.g) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_b = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.b) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		pBlock->set_low_color(pTable_r[best_mapping].m_lo, pTable_g[best_mapping].m_lo, pTable_b[best_mapping].m_lo);
		pBlock->set_high_color(pTable_r[best_mapping].m_hi, pTable_g[best_mapping].m_hi, pTable_b[best_mapping].m_hi);

		if (ATC_IDENTITY_SELECTOR_MAPPING_INDEX == best_mapping)
		{
			pBlock->m_sels[0] = pSelector->m_selectors[0];
			pBlock->m_sels[1] = pSelector->m_selectors[1];
			pBlock->m_sels[2] = pSelector->m_selectors[2];
			pBlock->m_sels[3] = pSelector->m_selectors[3];
		}
		else
		{
			const uint8_t* pSelectors_xlat = &g_etc1s_to_atc_selector_mappings[best_mapping][0];

			const uint32_t sel_bits0 = pSelector->m_selectors[0];
			const uint32_t sel_bits1 = pSelector->m_selectors[1];
			const uint32_t sel_bits2 = pSelector->m_selectors[2];
			const uint32_t sel_bits3 = pSelector->m_selectors[3];

			uint32_t atc_sels0 = 0, atc_sels1 = 0, atc_sels2 = 0, atc_sels3 = 0;

#define DO_X(x) { \
			const uint32_t x_shift = (x) * 2; \
			atc_sels0 |= (pSelectors_xlat[(sel_bits0 >> x_shift) & 3] << x_shift); \
			atc_sels1 |= (pSelectors_xlat[(sel_bits1 >> x_shift) & 3] << x_shift); \
			atc_sels2 |= (pSelectors_xlat[(sel_bits2 >> x_shift) & 3] << x_shift); \
			atc_sels3 |= (pSelectors_xlat[(sel_bits3 >> x_shift) & 3] << x_shift); }

			DO_X(0);
			DO_X(1);
			DO_X(2);
			DO_X(3);
#undef DO_X

			pBlock->m_sels[0] = (uint8_t)atc_sels0;
			pBlock->m_sels[1] = (uint8_t)atc_sels1;
			pBlock->m_sels[2] = (uint8_t)atc_sels2;
			pBlock->m_sels[3] = (uint8_t)atc_sels3;
		}
	}

#if BASISD_WRITE_NEW_ATC_TABLES
	static void create_etc1s_to_atc_conversion_tables()
	{
		// ATC 55
		FILE* pFile = nullptr;
		fopen_s(&pFile, "basisu_transcoder_tables_atc_55.inc", "w");

		uint32_t n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 31; hi++)
						{
							for (uint32_t lo = 0; lo <= 31; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 3) | (lo >> 2);
								colors[3] = (hi << 3) | (hi >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
		pFile = nullptr;

		// ATC 56
		fopen_s(&pFile, "basisu_transcoder_tables_atc_56.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 63; hi++)
						{
							for (uint32_t lo = 0; lo <= 31; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 3) | (lo >> 2);
								colors[3] = (hi << 2) | (hi >> 4);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
		
		// PVRTC2 45
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_45.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 31; hi++)
						{
							for (uint32_t lo = 0; lo <= 15; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1) | (lo >> 3);
								colors[0] = (colors[0] << 3) | (colors[0] >> 2);

								colors[3] = (hi << 3) | (hi >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);

#if 0
		// PVRTC2 34
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_34.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 15; hi++)
						{
							for (uint32_t lo = 0; lo <= 7; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 2) | (lo >> 1);
								colors[0] = (colors[0] << 3) | (colors[0] >> 2);

								colors[3] = (hi << 1) | (hi >> 3);
								colors[3] = (colors[3] << 3) | (colors[3] >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
#endif
#if 0
		// PVRTC2 44
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_44.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 15; hi++)
						{
							for (uint32_t lo = 0; lo <= 15; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1) | (lo >> 3);
								colors[0] = (colors[0] << 3) | (colors[0] >> 2);

								colors[3] = (hi << 1) | (hi >> 3);
								colors[3] = (colors[3] << 3) | (colors[3] >> 2);

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
#endif

		// PVRTC2 alpha 33
		fopen_s(&pFile, "basisu_transcoder_tables_pvrtc2_alpha_33.inc", "w");

		n = 0;

		for (int inten = 0; inten < 8; inten++)
		{
			for (uint32_t g = 0; g < 32; g++)
			{
				color32 block_colors[4];
				decoder_etc_block::get_diff_subblock_colors(block_colors, decoder_etc_block::pack_color5(color32(g, g, g, 255), false), inten);

				for (uint32_t sr = 0; sr < NUM_ETC1S_TO_ATC_SELECTOR_RANGES; sr++)
				{
					const uint32_t low_selector = g_etc1s_to_atc_selector_ranges[sr].m_low;
					const uint32_t high_selector = g_etc1s_to_atc_selector_ranges[sr].m_high;

					for (uint32_t m = 0; m < NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS; m++)
					{
						uint32_t best_lo = 0;
						uint32_t best_hi = 0;
						uint64_t best_err = UINT64_MAX;

						for (uint32_t hi = 0; hi <= 7; hi++)
						{
							for (uint32_t lo = 0; lo <= 7; lo++)
							{
								uint32_t colors[4];

								colors[0] = (lo << 1);
								colors[0] = (colors[0] << 4) | colors[0];

								colors[3] = (hi << 1) | 1;
								colors[3] = (colors[3] << 4) | colors[3];

								colors[1] = (colors[0] * 5 + colors[3] * 3) / 8;
								colors[2] = (colors[3] * 5 + colors[0] * 3) / 8;

								uint64_t total_err = 0;

								for (uint32_t s = low_selector; s <= high_selector; s++)
								{
									int err = block_colors[s].g - colors[g_etc1s_to_atc_selector_mappings[m][s]];

									int err_scale = 1;
									// Special case when the intensity table is 7, low_selector is 0, and high_selector is 3. In this extreme case, it's likely the encoder is trying to strongly favor 
									// the low/high selectors which are clamping to either 0 or 255.
									if (((inten == 7) && (low_selector == 0) && (high_selector == 3)) && ((s == 0) || (s == 3)))
										err_scale = 5;

									total_err += (err * err) * err_scale;
								}

								if (total_err < best_err)
								{
									best_err = total_err;
									best_lo = lo;
									best_hi = hi;
								}
							}
						}

						//assert(best_err <= 0xFFFF);
						best_err = basisu::minimum<uint32_t>(best_err, 0xFFFF);

						fprintf(pFile, "{%u,%u,%u},", best_lo, best_hi, (uint32_t)best_err);
						n++;
						if ((n & 31) == 31)
							fprintf(pFile, "\n");
					} // m
				} // sr
			} // g
		} // inten

		fclose(pFile);
	}
#endif // BASISD_WRITE_NEW_ATC_TABLES

#endif // BASISD_SUPPORT_ATC

#if BASISD_SUPPORT_PVRTC2
	struct pvrtc2_block
	{
		uint8_t m_modulation[4];

		union
		{
			union
			{
				// Opaque mode: RGB colora=554 and colorb=555
				struct
				{
					uint32_t m_mod_flag : 1;
					uint32_t m_blue_a : 4;
					uint32_t m_green_a : 5;
					uint32_t m_red_a : 5;
					uint32_t m_hard_flag : 1;
					uint32_t m_blue_b : 5;
					uint32_t m_green_b : 5;
					uint32_t m_red_b : 5;
					uint32_t m_opaque_flag : 1;

				} m_opaque_color_data;

				// Transparent mode: RGBA colora=4433 and colorb=4443
				struct
				{
					uint32_t m_mod_flag : 1;
					uint32_t m_blue_a : 3;
					uint32_t m_green_a : 4;
					uint32_t m_red_a : 4;
					uint32_t m_alpha_a : 3;
					uint32_t m_hard_flag : 1;
					uint32_t m_blue_b : 4;
					uint32_t m_green_b : 4;
					uint32_t m_red_b : 4;
					uint32_t m_alpha_b : 3;
					uint32_t m_opaque_flag : 1;

				} m_trans_color_data;
			};

			uint32_t m_color_data_bits;
		};

		// 554
		void set_low_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 32) && (b < 16));
			m_opaque_color_data.m_red_a = r;
			m_opaque_color_data.m_green_a = g;
			m_opaque_color_data.m_blue_a = b;
		}

		// 555
		void set_high_color(uint32_t r, uint32_t g, uint32_t b)
		{
			assert((r < 32) && (g < 32) && (b < 32));
			m_opaque_color_data.m_red_b = r;
			m_opaque_color_data.m_green_b = g;
			m_opaque_color_data.m_blue_b = b;
		}

		// 4433
		void set_trans_low_color(uint32_t r, uint32_t g, uint32_t b, uint32_t a)
		{
			assert((r < 16) && (g < 16) && (b < 8) && (a < 8));
			m_trans_color_data.m_red_a = r;
			m_trans_color_data.m_green_a = g;
			m_trans_color_data.m_blue_a = b;
			m_trans_color_data.m_alpha_a = a;
		}

		// 4443
		void set_trans_high_color(uint32_t r, uint32_t g, uint32_t b, uint32_t a)
		{
			assert((r < 16) && (g < 16) && (b < 16) && (a < 8));
			m_trans_color_data.m_red_b = r;
			m_trans_color_data.m_green_b = g;
			m_trans_color_data.m_blue_b = b;
			m_trans_color_data.m_alpha_b = a;
		}
	};

	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_trans_match34[256];

	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_trans_match44[256];
		
	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_alpha_match33[256];
	
	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_alpha_match33_0[256];

	static struct
	{
		uint8_t m_l, m_h;
	} g_pvrtc2_alpha_match33_3[256];
		
	// PVRTC2 can be forced to look like a slightly weaker variant of ATC/BC1, so that's what we do here for simplicity.
	static void convert_etc1s_to_pvrtc2_rgb(void* pDst, const endpoint* pEndpoints, const selector* pSelector)
	{
		pvrtc2_block* pBlock = static_cast<pvrtc2_block*>(pDst);

		pBlock->m_opaque_color_data.m_hard_flag = 1;
		pBlock->m_opaque_color_data.m_mod_flag = 0;
		pBlock->m_opaque_color_data.m_opaque_flag = 1;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		if (low_selector == high_selector)
		{
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			pBlock->set_low_color(g_atc_match55_equals_1[r].m_lo, g_atc_match55_equals_1[g].m_lo, g_pvrtc2_match45_equals_1[b].m_lo);
			pBlock->set_high_color(g_atc_match55_equals_1[r].m_hi, g_atc_match55_equals_1[g].m_hi, g_pvrtc2_match45_equals_1[b].m_hi);

			pBlock->m_modulation[0] = 0x55;
			pBlock->m_modulation[1] = 0x55;
			pBlock->m_modulation[2] = 0x55;
			pBlock->m_modulation[3] = 0x55;

			return;
		}
		else if ((inten_table >= 7) && (pSelector->m_num_unique_selectors == 2) && (pSelector->m_lo_selector == 0) && (pSelector->m_hi_selector == 3))
		{
			color32 block_colors[4];
			decoder_etc_block::get_block_colors5(block_colors, base_color, inten_table);

			const uint32_t r0 = block_colors[0].r;
			const uint32_t g0 = block_colors[0].g;
			const uint32_t b0 = block_colors[0].b;

			const uint32_t r1 = block_colors[3].r;
			const uint32_t g1 = block_colors[3].g;
			const uint32_t b1 = block_colors[3].b;

			pBlock->set_low_color(g_atc_match5[r0].m_hi, g_atc_match5[g0].m_hi, g_pvrtc2_match4[b0].m_hi);
			pBlock->set_high_color(g_atc_match5[r1].m_hi, g_atc_match5[g1].m_hi, g_atc_match5[b1].m_hi);

			pBlock->m_modulation[0] = pSelector->m_selectors[0];
			pBlock->m_modulation[1] = pSelector->m_selectors[1];
			pBlock->m_modulation[2] = pSelector->m_selectors[2];
			pBlock->m_modulation[3] = pSelector->m_selectors[3];

			return;
		}

		const uint32_t selector_range_table = g_etc1s_to_atc_selector_range_index[low_selector][high_selector];

		//[32][8][RANGES][MAPPING]
		const etc1s_to_atc_solution* pTable_r = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.r) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_g = &g_etc1s_to_atc_55[(inten_table * 32 + base_color.g) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];
		const etc1s_to_atc_solution* pTable_b = &g_etc1s_to_pvrtc2_45[(inten_table * 32 + base_color.b) * (NUM_ETC1S_TO_ATC_SELECTOR_RANGES * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS) + selector_range_table * NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS];

		uint32_t best_err = UINT_MAX;
		uint32_t best_mapping = 0;

		assert(NUM_ETC1S_TO_ATC_SELECTOR_MAPPINGS == 10);
#define DO_ITER(m) { uint32_t total_err = pTable_r[m].m_err + pTable_g[m].m_err + pTable_b[m].m_err; if (total_err < best_err) { best_err = total_err; best_mapping = m; } }
		DO_ITER(0); DO_ITER(1); DO_ITER(2); DO_ITER(3); DO_ITER(4);
		DO_ITER(5); DO_ITER(6); DO_ITER(7); DO_ITER(8); DO_ITER(9);
#undef DO_ITER

		pBlock->set_low_color(pTable_r[best_mapping].m_lo, pTable_g[best_mapping].m_lo, pTable_b[best_mapping].m_lo);
		pBlock->set_high_color(pTable_r[best_mapping].m_hi, pTable_g[best_mapping].m_hi, pTable_b[best_mapping].m_hi);

		if (ATC_IDENTITY_SELECTOR_MAPPING_INDEX == best_mapping)
		{
			pBlock->m_modulation[0] = pSelector->m_selectors[0];
			pBlock->m_modulation[1] = pSelector->m_selectors[1];
			pBlock->m_modulation[2] = pSelector->m_selectors[2];
			pBlock->m_modulation[3] = pSelector->m_selectors[3];
		}
		else
		{
			// TODO: We could make this faster using several precomputed 256 entry tables, like ETC1S->BC1 does.
			const uint8_t* pSelectors_xlat = &g_etc1s_to_atc_selector_mappings[best_mapping][0];

			const uint32_t sel_bits0 = pSelector->m_selectors[0];
			const uint32_t sel_bits1 = pSelector->m_selectors[1];
			const uint32_t sel_bits2 = pSelector->m_selectors[2];
			const uint32_t sel_bits3 = pSelector->m_selectors[3];

			uint32_t sels0 = 0, sels1 = 0, sels2 = 0, sels3 = 0;

#define DO_X(x) { \
			const uint32_t x_shift = (x) * 2; \
			sels0 |= (pSelectors_xlat[(sel_bits0 >> x_shift) & 3] << x_shift); \
			sels1 |= (pSelectors_xlat[(sel_bits1 >> x_shift) & 3] << x_shift); \
			sels2 |= (pSelectors_xlat[(sel_bits2 >> x_shift) & 3] << x_shift); \
			sels3 |= (pSelectors_xlat[(sel_bits3 >> x_shift) & 3] << x_shift); }

			DO_X(0);
			DO_X(1);
			DO_X(2);
			DO_X(3);
#undef DO_X

			pBlock->m_modulation[0] = (uint8_t)sels0;
			pBlock->m_modulation[1] = (uint8_t)sels1;
			pBlock->m_modulation[2] = (uint8_t)sels2;
			pBlock->m_modulation[3] = (uint8_t)sels3;
		}
	}
				
	static inline vec4F* vec4F_set_scalar(vec4F* pV, float x) { pV->c[0] = x; pV->c[1] = x; pV->c[2] = x;	pV->c[3] = x;	return pV; }
	static inline vec4F* vec4F_set(vec4F* pV, float x, float y, float z, float w) { pV->c[0] = x;	pV->c[1] = y;	pV->c[2] = z;	pV->c[3] = w;	return pV; }
	static inline vec4F* vec4F_saturate_in_place(vec4F* pV) { pV->c[0] = saturate(pV->c[0]); pV->c[1] = saturate(pV->c[1]); pV->c[2] = saturate(pV->c[2]); pV->c[3] = saturate(pV->c[3]); return pV; }
	static inline vec4F vec4F_saturate(const vec4F* pV) { vec4F res; res.c[0] = saturate(pV->c[0]); res.c[1] = saturate(pV->c[1]); res.c[2] = saturate(pV->c[2]); res.c[3] = saturate(pV->c[3]); return res; }
	static inline vec4F vec4F_from_color(const color32* pC) { vec4F res; vec4F_set(&res, pC->c[0], pC->c[1], pC->c[2], pC->c[3]); return res; }
	static inline vec4F vec4F_add(const vec4F* pLHS, const vec4F* pRHS) { vec4F res; vec4F_set(&res, pLHS->c[0] + pRHS->c[0], pLHS->c[1] + pRHS->c[1], pLHS->c[2] + pRHS->c[2], pLHS->c[3] + pRHS->c[3]); return res; }
	static inline vec4F vec4F_sub(const vec4F* pLHS, const vec4F* pRHS) { vec4F res; vec4F_set(&res, pLHS->c[0] - pRHS->c[0], pLHS->c[1] - pRHS->c[1], pLHS->c[2] - pRHS->c[2], pLHS->c[3] - pRHS->c[3]); return res; }
	static inline float vec4F_dot(const vec4F* pLHS, const vec4F* pRHS) { return pLHS->c[0] * pRHS->c[0] + pLHS->c[1] * pRHS->c[1] + pLHS->c[2] * pRHS->c[2] + pLHS->c[3] * pRHS->c[3]; }
	static inline vec4F vec4F_mul(const vec4F* pLHS, float s) { vec4F res; vec4F_set(&res, pLHS->c[0] * s, pLHS->c[1] * s, pLHS->c[2] * s, pLHS->c[3] * s); return res; }
	static inline vec4F* vec4F_normalize_in_place(vec4F* pV) { float s = pV->c[0] * pV->c[0] + pV->c[1] * pV->c[1] + pV->c[2] * pV->c[2] + pV->c[3] * pV->c[3]; if (s != 0.0f) { s = 1.0f / sqrtf(s); pV->c[0] *= s; pV->c[1] *= s; pV->c[2] *= s; pV->c[3] *= s; } return pV; }

	static color32 convert_rgba_5554_to_8888(const color32& col)
	{
		return color32((col[0] << 3) | (col[0] >> 2), (col[1] << 3) | (col[1] >> 2), (col[2] << 3) | (col[2] >> 2), (col[3] << 4) | col[3]);
	}

	static inline int sq(int x) { return x * x; }
						
	// PVRTC2 is a slightly borked format for alpha: In Non-Interpolated mode, the way AlphaB8 is expanded from 4 to 8 bits means it can never be 0. 
	// This is actually very bad, because on 100% transparent blocks which have non-trivial color pixels, part of the color channel will leak into alpha! 
	// And there's nothing straightforward we can do because using the other modes is too expensive/complex. I can see why Apple didn't adopt it.
	static void convert_etc1s_to_pvrtc2_rgba(void* pDst, const endpoint* pEndpoints, const selector* pSelector, const endpoint* pEndpoint_codebook, const selector* pSelector_codebook)
	{
		pvrtc2_block* pBlock = static_cast<pvrtc2_block*>(pDst);

		const endpoint& alpha_endpoint = pEndpoint_codebook[((uint16_t*)pBlock)[0]];
		const selector& alpha_selectors = pSelector_codebook[((uint16_t*)pBlock)[1]];

		pBlock->m_opaque_color_data.m_hard_flag = 1;
		pBlock->m_opaque_color_data.m_mod_flag = 0;
		pBlock->m_opaque_color_data.m_opaque_flag = 0;

		const int num_unique_alpha_selectors = alpha_selectors.m_num_unique_selectors;

		const color32& alpha_base_color = alpha_endpoint.m_color5;
		const uint32_t alpha_inten_table = alpha_endpoint.m_inten5;

		int constant_alpha_val = -1;

		int alpha_block_colors[4];
		decoder_etc_block::get_block_colors5_g(alpha_block_colors, alpha_base_color, alpha_inten_table);

		if (num_unique_alpha_selectors == 1)
		{
			constant_alpha_val = alpha_block_colors[alpha_selectors.m_lo_selector];
		}
		else
		{
			constant_alpha_val = alpha_block_colors[alpha_selectors.m_lo_selector];

			for (uint32_t i = alpha_selectors.m_lo_selector + 1; i <= alpha_selectors.m_hi_selector; i++)
			{
				if (constant_alpha_val != alpha_block_colors[i])
				{
					constant_alpha_val = -1;
					break;
				}
			}
		}

		if (constant_alpha_val >= 250)
		{
			// It's opaque enough, so don't bother trying to encode it as an alpha block.
			convert_etc1s_to_pvrtc2_rgb(pDst, pEndpoints, pSelector);
			return;
		}

		const color32& base_color = pEndpoints->m_color5;
		const uint32_t inten_table = pEndpoints->m_inten5;

		const uint32_t low_selector = pSelector->m_lo_selector;
		const uint32_t high_selector = pSelector->m_hi_selector;

		const int num_unique_color_selectors = pSelector->m_num_unique_selectors;
				
		// We need to reencode the block at the pixel level, unfortunately, from two ETC1S planes.
		// Do 4D incremental PCA, project all pixels to this hyperline, then quantize to packed endpoints and compute the modulation values.
		const int br = (base_color.r << 3) | (base_color.r >> 2);
		const int bg = (base_color.g << 3) | (base_color.g >> 2);
		const int bb = (base_color.b << 3) | (base_color.b >> 2);
		
		color32 block_cols[4];
		for (uint32_t i = 0; i < 4; i++)
		{
			const int ci = g_etc1_inten_tables[inten_table][i];
			block_cols[i].set_clamped(br + ci, bg + ci, bb + ci, alpha_block_colors[i]);
		}

		bool solid_color_block = true;
		if (num_unique_color_selectors > 1)
		{
			for (uint32_t i = low_selector + 1; i <= high_selector; i++)
			{
				if ((block_cols[low_selector].r != block_cols[i].r) || (block_cols[low_selector].g != block_cols[i].g) || (block_cols[low_selector].b != block_cols[i].b))
				{
					solid_color_block = false;
					break;
				}
			}
		}

		if ((solid_color_block) && (constant_alpha_val >= 0))
		{
			// Constant color/alpha block.
			// This is more complex than it may seem because of the way color and alpha are packed in PVRTC2. We need to evaluate mod0, mod1 and mod3 encodings to find the best one.
			uint32_t r, g, b;
			decoder_etc_block::get_block_color5(base_color, inten_table, low_selector, r, g, b);

			// Mod 0
			uint32_t lr0 = (r * 15 + 128) / 255, lg0 = (g * 15 + 128) / 255, lb0 = (b * 7 + 128) / 255; 
			uint32_t la0 = g_pvrtc2_alpha_match33_0[constant_alpha_val].m_l;

			uint32_t cr0 = (lr0 << 1) | (lr0 >> 3);
			uint32_t cg0 = (lg0 << 1) | (lg0 >> 3);
			uint32_t cb0 = (lb0 << 2) | (lb0 >> 1);
			uint32_t ca0 = (la0 << 1);
			
			cr0 = (cr0 << 3) | (cr0 >> 2);
			cg0 = (cg0 << 3) | (cg0 >> 2);
			cb0 = (cb0 << 3) | (cb0 >> 2);
			ca0 = (ca0 << 4) | ca0;

			uint32_t err0 = sq(cr0 - r) + sq(cg0 - g) + sq(cb0 - b) + sq(ca0 - constant_alpha_val) * 2;

			// If the alpha is < 3 or so we're kinda screwed. It's better to have some RGB error than it is to turn a 100% transparent area slightly opaque.
			if ((err0 == 0) || (constant_alpha_val < 3))
			{
				pBlock->set_trans_low_color(lr0, lg0, lb0, la0);
				pBlock->set_trans_high_color(0, 0, 0, 0);

				pBlock->m_modulation[0] = 0;
				pBlock->m_modulation[1] = 0;
				pBlock->m_modulation[2] = 0;
				pBlock->m_modulation[3] = 0;
				return;
			}

			// Mod 3
			uint32_t lr3 = (r * 15 + 128) / 255, lg3 = (g * 15 + 128) / 255, lb3 = (b * 15 + 128) / 255;
			uint32_t la3 = g_pvrtc2_alpha_match33_3[constant_alpha_val].m_l;

			uint32_t cr3 = (lr3 << 1) | (lr3 >> 3);
			uint32_t cg3 = (lg3 << 1) | (lg3 >> 3);
			uint32_t cb3 = (lb3 << 1) | (lb3 >> 3);
			uint32_t ca3 = (la3 << 1) | 1;
			
			cr3 = (cr3 << 3) | (cr3 >> 2);
			cg3 = (cg3 << 3) | (cg3 >> 2);
			cb3 = (cb3 << 3) | (cb3 >> 2);
			ca3 = (ca3 << 4) | ca3;

			uint32_t err3 = sq(cr3 - r) + sq(cg3 - g) + sq(cb3 - b) + sq(ca3 - constant_alpha_val) * 2;
			
			// Mod 1
			uint32_t lr1 = g_pvrtc2_trans_match44[r].m_l, lg1 = g_pvrtc2_trans_match44[g].m_l, lb1 = g_pvrtc2_trans_match34[b].m_l;
			uint32_t hr1 = g_pvrtc2_trans_match44[r].m_h, hg1 = g_pvrtc2_trans_match44[g].m_h, hb1 = g_pvrtc2_trans_match34[b].m_h;
			uint32_t la1 = g_pvrtc2_alpha_match33[constant_alpha_val].m_l, ha1 = g_pvrtc2_alpha_match33[constant_alpha_val].m_h;

			uint32_t clr1 = (lr1 << 1) | (lr1 >> 3);
			uint32_t clg1 = (lg1 << 1) | (lg1 >> 3);
			uint32_t clb1 = (lb1 << 2) | (lb1 >> 1);
			uint32_t cla1 = (la1 << 1);

			clr1 = (clr1 << 3) | (clr1 >> 2);
			clg1 = (clg1 << 3) | (clg1 >> 2);
			clb1 = (clb1 << 3) | (clb1 >> 2);
			cla1 = (cla1 << 4) | cla1;

			uint32_t chr1 = (hr1 << 1) | (hr1 >> 3);
			uint32_t chg1 = (hg1 << 1) | (hg1 >> 3);
			uint32_t chb1 = (hb1 << 1) | (hb1 >> 3);
			uint32_t cha1 = (ha1 << 1) | 1;

			chr1 = (chr1 << 3) | (chr1 >> 2);
			chg1 = (chg1 << 3) | (chg1 >> 2);
			chb1 = (chb1 << 3) | (chb1 >> 2);
			cha1 = (cha1 << 4) | cha1;

			uint32_t r1 = (clr1 * 5 + chr1 * 3) / 8;
			uint32_t g1 = (clg1 * 5 + chg1 * 3) / 8;
			uint32_t b1 = (clb1 * 5 + chb1 * 3) / 8;
			uint32_t a1 = (cla1 * 5 + cha1 * 3) / 8;

			uint32_t err1 = sq(r1 - r) + sq(g1 - g) + sq(b1 - b) + sq(a1 - constant_alpha_val) * 2;

			if ((err1 < err0) && (err1 < err3))
			{
				pBlock->set_trans_low_color(lr1, lg1, lb1, la1);
				pBlock->set_trans_high_color(hr1, hg1, hb1, ha1);

				pBlock->m_modulation[0] = 0x55;
				pBlock->m_modulation[1] = 0x55;
				pBlock->m_modulation[2] = 0x55;
				pBlock->m_modulation[3] = 0x55;
			}
			else if (err0 < err3)
			{
				pBlock->set_trans_low_color(lr0, lg0, lb0, la0);
				pBlock->set_trans_high_color(0, 0, 0, 0);

				pBlock->m_modulation[0] = 0;
				pBlock->m_modulation[1] = 0;
				pBlock->m_modulation[2] = 0;
				pBlock->m_modulation[3] = 0;
			}
			else
			{
				pBlock->set_trans_low_color(0, 0, 0, 0);
				pBlock->set_trans_high_color(lr3, lg3, lb3, la3);

				pBlock->m_modulation[0] = 0xFF;
				pBlock->m_modulation[1] = 0xFF;
				pBlock->m_modulation[2] = 0xFF;
				pBlock->m_modulation[3] = 0xFF;
			}

			return;
		}

		// It's a complex block with non-solid color and/or alpha pixels.
		vec4F minColor, maxColor;

		if (solid_color_block)
		{
			// It's a solid color block.
			uint32_t low_a = block_cols[alpha_selectors.m_lo_selector].a;
			uint32_t high_a = block_cols[alpha_selectors.m_hi_selector].a;
			
			const float S = 1.0f / 255.0f;
			vec4F_set(&minColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, low_a * S);
			vec4F_set(&maxColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, high_a * S);
		}
		else if (constant_alpha_val >= 0)
		{
			// It's a solid alpha block.
			const float S = 1.0f / 255.0f;
			vec4F_set(&minColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, constant_alpha_val * S);
			vec4F_set(&maxColor, block_cols[high_selector].r * S, block_cols[high_selector].g * S, block_cols[high_selector].b * S, constant_alpha_val * S);
	   }
		// See if any of the block colors got clamped - if so the principle axis got distorted (it's no longer just the ETC1S luma axis). 
		// To keep quality up we need to use full 4D PCA in this case.
		else if ((block_cols[low_selector].c[0] == 0) || (block_cols[high_selector].c[0] == 255) ||
				(block_cols[low_selector].c[1] == 0) || (block_cols[high_selector].c[1] == 255) ||
				(block_cols[low_selector].c[2] == 0) || (block_cols[high_selector].c[2] == 255) ||
				(block_cols[alpha_selectors.m_lo_selector].c[3] == 0) || (block_cols[alpha_selectors.m_hi_selector].c[3] == 255))
		{
			// Find principle component of RGBA colors treated as 4D vectors.
			color32 pixels[16];

			uint32_t sum_r = 0, sum_g = 0, sum_b = 0, sum_a = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				color32 rgb(block_cols[pSelector->get_selector(i & 3, i >> 2)]);
				uint32_t a = block_cols[alpha_selectors.get_selector(i & 3, i >> 2)].a;

				pixels[i].set(rgb.r, rgb.g, rgb.b, a);

				sum_r += rgb.r;
				sum_g += rgb.g;
				sum_b += rgb.b;
				sum_a += a;
			}

			vec4F meanColor;
			vec4F_set(&meanColor, (float)sum_r, (float)sum_g, (float)sum_b, (float)sum_a);
			vec4F meanColorScaled = vec4F_mul(&meanColor, 1.0f / 16.0f);

			meanColor = vec4F_mul(&meanColor, 1.0f / (float)(16.0f * 255.0f));
			vec4F_saturate_in_place(&meanColor);

			vec4F axis;
			vec4F_set_scalar(&axis, 0.0f);
			// Why this incremental method? Because it's stable and predictable. Covar+power method can require a lot of iterations to converge in 4D.
			for (uint32_t i = 0; i < 16; i++)
			{
				vec4F color = vec4F_from_color(&pixels[i]);
				color = vec4F_sub(&color, &meanColorScaled);
				vec4F a = vec4F_mul(&color, color.c[0]);
				vec4F b = vec4F_mul(&color, color.c[1]);
				vec4F c = vec4F_mul(&color, color.c[2]);
				vec4F d = vec4F_mul(&color, color.c[3]);
				vec4F n = i ? axis : color;
				vec4F_normalize_in_place(&n);
				axis.c[0] += vec4F_dot(&a, &n);
				axis.c[1] += vec4F_dot(&b, &n);
				axis.c[2] += vec4F_dot(&c, &n);
				axis.c[3] += vec4F_dot(&d, &n);
			}

			vec4F_normalize_in_place(&axis);
						
			if (vec4F_dot(&axis, &axis) < .5f)
				vec4F_set_scalar(&axis, .5f);

			float l = 1e+9f, h = -1e+9f;

			for (uint32_t i = 0; i < 16; i++)
			{
				vec4F color = vec4F_from_color(&pixels[i]);

				vec4F q = vec4F_sub(&color, &meanColorScaled);
				float d = vec4F_dot(&q, &axis);

				l = basisu::minimum(l, d);
				h = basisu::maximum(h, d);
			}

			l *= (1.0f / 255.0f);
			h *= (1.0f / 255.0f);

			vec4F b0 = vec4F_mul(&axis, l);
			vec4F b1 = vec4F_mul(&axis, h);
			vec4F c0 = vec4F_add(&meanColor, &b0);
			vec4F c1 = vec4F_add(&meanColor, &b1);
			minColor = vec4F_saturate(&c0);
			maxColor = vec4F_saturate(&c1);
			if (minColor.c[3] > maxColor.c[3])
			{
				// VS 2019 release Code Generator issue
				//std::swap(minColor, maxColor);

				float a = minColor.c[0], b = minColor.c[1], c = minColor.c[2], d = minColor.c[3];
				minColor.c[0] = maxColor.c[0]; minColor.c[1] = maxColor.c[1]; minColor.c[2] = maxColor.c[2]; minColor.c[3] = maxColor.c[3];
				minColor.c[0] = maxColor.c[0]; minColor.c[1] = maxColor.c[1]; minColor.c[2] = maxColor.c[2]; minColor.c[3] = maxColor.c[3];
				maxColor.c[0] = a; maxColor.c[1] = b; maxColor.c[2] = c; maxColor.c[3] = d;
			}
		}
		else
		{
			// We know the RGB axis is luma, because it's an ETC1S block and none of the block colors got clamped. So we only need to use 2D PCA.
			// We project each LA vector onto two 2D lines with axes (1,1) and (1,-1) and find the largest projection to determine if axis A is flipped relative to L.
			uint32_t block_cols_l[4], block_cols_a[4];
			for (uint32_t i = 0; i < 4; i++)
			{
				block_cols_l[i] = block_cols[i].r + block_cols[i].g + block_cols[i].b;
				block_cols_a[i] = block_cols[i].a * 3;
			}

			int p0_min = INT_MAX, p0_max = INT_MIN;
			int p1_min = INT_MAX, p1_max = INT_MIN;
			for (uint32_t y = 0; y < 4; y++)
			{
				const uint32_t cs = pSelector->m_selectors[y];
				const uint32_t as = alpha_selectors.m_selectors[y];

				{
					const int l = block_cols_l[cs & 3];
					const int a = block_cols_a[as & 3];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
				{
					const int l = block_cols_l[(cs >> 2) & 3];
					const int a = block_cols_a[(as >> 2) & 3];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
				{
					const int l = block_cols_l[(cs >> 4) & 3];
					const int a = block_cols_a[(as >> 4) & 3];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
				{
					const int l = block_cols_l[cs >> 6];
					const int a = block_cols_a[as >> 6];
					const int p0 = l + a; p0_min = basisu::minimum(p0_min, p0); p0_max = basisu::maximum(p0_max, p0);
					const int p1 = l - a; p1_min = basisu::minimum(p1_min, p1); p1_max = basisu::maximum(p1_max, p1);
				}
			}

			int dist0 = p0_max - p0_min;
			int dist1 = p1_max - p1_min;

			const float S = 1.0f / 255.0f;

			vec4F_set(&minColor, block_cols[low_selector].r * S, block_cols[low_selector].g * S, block_cols[low_selector].b * S, block_cols[alpha_selectors.m_lo_selector].a * S);
			vec4F_set(&maxColor, block_cols[high_selector].r * S, block_cols[high_selector].g * S, block_cols[high_selector].b * S, block_cols[alpha_selectors.m_hi_selector].a * S);

			// See if the A component of the principle axis is flipped relative to L. If so, we need to flip either RGB or A bounds.
			if (dist1 > dist0)
			{
				std::swap(minColor.c[0], maxColor.c[0]);
				std::swap(minColor.c[1], maxColor.c[1]);
				std::swap(minColor.c[2], maxColor.c[2]);
			}
		}

		// 4433 4443
		color32 trialMinColor, trialMaxColor;
				
		trialMinColor.set_clamped((int)(minColor.c[0] * 15.0f + .5f), (int)(minColor.c[1] * 15.0f + .5f), (int)(minColor.c[2] * 7.0f + .5f), (int)(minColor.c[3] * 7.0f + .5f));
		trialMaxColor.set_clamped((int)(maxColor.c[0] * 15.0f + .5f), (int)(maxColor.c[1] * 15.0f + .5f), (int)(maxColor.c[2] * 15.0f + .5f), (int)(maxColor.c[3] * 7.0f + .5f));
				
		pBlock->set_trans_low_color(trialMinColor.r, trialMinColor.g, trialMinColor.b, trialMinColor.a);
		pBlock->set_trans_high_color(trialMaxColor.r, trialMaxColor.g, trialMaxColor.b, trialMaxColor.a);

		color32 color_a((trialMinColor.r << 1) | (trialMinColor.r >> 3), (trialMinColor.g << 1) | (trialMinColor.g >> 3), (trialMinColor.b << 2) | (trialMinColor.b >> 1), trialMinColor.a << 1);
		color32 color_b((trialMaxColor.r << 1) | (trialMaxColor.r >> 3), (trialMaxColor.g << 1) | (trialMaxColor.g >> 3), (trialMaxColor.b << 1) | (trialMaxColor.b >> 3), (trialMaxColor.a << 1) | 1);

		color32 color0(convert_rgba_5554_to_8888(color_a));
		color32 color3(convert_rgba_5554_to_8888(color_b));

		const int lr = color0.r;
		const int lg = color0.g;
		const int lb = color0.b;
		const int la = color0.a;

		const int axis_r = color3.r - lr;
		const int axis_g = color3.g - lg;
		const int axis_b = color3.b - lb;
		const int axis_a = color3.a - la;
		const int len_a = (axis_r * axis_r) + (axis_g * axis_g) + (axis_b * axis_b) + (axis_a * axis_a);

		const int thresh01 = (len_a * 3) / 16;
		const int thresh12 = len_a >> 1;
		const int thresh23 = (len_a * 13) / 16;

		if ((axis_r | axis_g | axis_b) == 0)
		{
			int ca_sel[4];

			for (uint32_t i = 0; i < 4; i++)
			{
				int ca = (block_cols[i].a - la) * axis_a;
				ca_sel[i] = (ca >= thresh23) + (ca >= thresh12) + (ca >= thresh01);
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				const uint32_t a_sels = alpha_selectors.m_selectors[y];

				uint32_t sel = ca_sel[a_sels & 3] | (ca_sel[(a_sels >> 2) & 3] << 2) | (ca_sel[(a_sels >> 4) & 3] << 4) | (ca_sel[a_sels >> 6] << 6);

				pBlock->m_modulation[y] = (uint8_t)sel;
			}
		}
		else
		{
			int cy[4], ca[4];

			for (uint32_t i = 0; i < 4; i++)
			{
				cy[i] = (block_cols[i].r - lr) * axis_r + (block_cols[i].g - lg) * axis_g + (block_cols[i].b - lb) * axis_b;
				ca[i] = (block_cols[i].a - la) * axis_a;
			}

			for (uint32_t y = 0; y < 4; y++)
			{
				const uint32_t c_sels = pSelector->m_selectors[y];
				const uint32_t a_sels = alpha_selectors.m_selectors[y];

				const int d0 = cy[c_sels & 3] + ca[a_sels & 3];
				const int d1 = cy[(c_sels >> 2) & 3] + ca[(a_sels >> 2) & 3];
				const int d2 = cy[(c_sels >> 4) & 3] + ca[(a_sels >> 4) & 3];
				const int d3 = cy[c_sels >> 6] + ca[a_sels >> 6];

				uint32_t sel = ((d0 >= thresh23) + (d0 >= thresh12) + (d0 >= thresh01)) |
					(((d1 >= thresh23) + (d1 >= thresh12) + (d1 >= thresh01)) << 2) |
					(((d2 >= thresh23) + (d2 >= thresh12) + (d2 >= thresh01)) << 4) |
					(((d3 >= thresh23) + (d3 >= thresh12) + (d3 >= thresh01)) << 6);

				pBlock->m_modulation[y] = (uint8_t)sel;
			}
		}
	}
		
	static void transcoder_init_pvrtc2()
	{
		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 8; l++)
			{
				uint32_t le = (l << 1);
				le = (le << 4) | le;

				for (uint32_t h = 0; h < 8; h++)
				{
					uint32_t he = (h << 1) | 1;
					he = (he << 4) | he;

					uint32_t m = (le * 5 + he * 3) / 8;

					int err = (int)labs((int)v - (int)m);
					if (err < lowest_err)
					{
						lowest_err = err;
						best_l = l;
						best_h = h;
					}
				}
			}

			g_pvrtc2_alpha_match33[v].m_l = (uint8_t)best_l;
			g_pvrtc2_alpha_match33[v].m_h = (uint8_t)best_h;
		}

		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 8; l++)
			{
				uint32_t le = (l << 1);
				le = (le << 4) | le;

				int err = (int)labs((int)v - (int)le);
				if (err < lowest_err)
				{
					lowest_err = err;
					best_l = l;
					best_h = l;
				}
			}

			g_pvrtc2_alpha_match33_0[v].m_l = (uint8_t)best_l;
			g_pvrtc2_alpha_match33_0[v].m_h = (uint8_t)best_h;
		}

		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t h = 0; h < 8; h++)
			{
				uint32_t he = (h << 1) | 1;
				he = (he << 4) | he;

				int err = (int)labs((int)v - (int)he);
				if (err < lowest_err)
				{
					lowest_err = err;
					best_l = h;
					best_h = h;
				}
			}

			g_pvrtc2_alpha_match33_3[v].m_l = (uint8_t)best_l;
			g_pvrtc2_alpha_match33_3[v].m_h = (uint8_t)best_h;
		}

		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 8; l++)
			{
				uint32_t le = (l << 2) | (l >> 1);
				le = (le << 3) | (le >> 2);

				for (uint32_t h = 0; h < 16; h++)
				{
					uint32_t he = (h << 1) | (h >> 3);
					he = (he << 3) | (he >> 2);

					uint32_t m = (le * 5 + he * 3) / 8;

					int err = (int)labs((int)v - (int)m);
					if (err < lowest_err)
					{
						lowest_err = err;
						best_l = l;
						best_h = h;
					}
				}
			}

			g_pvrtc2_trans_match34[v].m_l = (uint8_t)best_l;
			g_pvrtc2_trans_match34[v].m_h = (uint8_t)best_h;
		}
				
		for (uint32_t v = 0; v < 256; v++)
		{
			int best_l = 0, best_h = 0, lowest_err = INT_MAX;

			for (uint32_t l = 0; l < 16; l++)
			{
				uint32_t le = (l << 1) | (l >> 3);
				le = (le << 3) | (le >> 2);

				for (uint32_t h = 0; h < 16; h++)
				{
					uint32_t he = (h << 1) | (h >> 3);
					he = (he << 3) | (he >> 2);

					uint32_t m = (le * 5 + he * 3) / 8;

					int err = (int)labs((int)v - (int)m);
					if (err < lowest_err)
					{
						lowest_err = err;
						best_l = l;
						best_h = h;
					}
				}
			}

			g_pvrtc2_trans_match44[v].m_l = (uint8_t)best_l;
			g_pvrtc2_trans_match44[v].m_h = (uint8_t)best_h;
		}
	}
#endif // BASISD_SUPPORT_PVRTC2

	//------------------------------------------------------------------------------------------------
	
	// BC7 mode 5 RGB encoder

#if BASISD_SUPPORT_BC7_MODE5
	namespace bc7_mode_5_encoder
	{		
		static float g_mode5_rgba_midpoints[128];

		void encode_bc7_mode5_init()
		{
			// Mode 5 endpoint midpoints
			for (uint32_t i = 0; i < 128; i++)
			{
				uint32_t vl = (i << 1);
				vl |= (vl >> 7);
				float lo = vl / 255.0f;

				uint32_t vh = basisu::minimumi(127, i + 1) << 1;
				vh |= (vh >> 7);
				float hi = vh / 255.0f;

				if (i == 127)
					g_mode5_rgba_midpoints[i] = 1e+15f;
				else
					g_mode5_rgba_midpoints[i] = (lo + hi) / 2.0f;
			}
		}

		static inline uint32_t from_7(uint32_t v)
		{
			assert(v < 128);
			return (v << 1) | (v >> 6);
		}

		static inline int to_7(float c)
		{
			assert((c >= 0) && (c <= 1.0f));

			int vl = (int)(c * 127.0f);
			vl += (c > g_mode5_rgba_midpoints[vl]);
			return clampi(vl, 0, 127);
		}

		static inline int to_7(int c8)
		{
			assert((c8 >= 0) && (c8 <= 255));

			float c = (float)c8 * (1.0f / 255.0f);

			int vl = (int)(c * 127.0f);
			vl += (c > g_mode5_rgba_midpoints[vl]);
			return clampi(vl, 0, 127);
		}

		// This is usable with ASTC as well, which uses the same 2-bit interpolation weights.
		static inline uint32_t bc7_interp2(uint32_t l, uint32_t h, uint32_t w)
		{
			assert(w < 4);
			return (l * (64 - basist::g_bc7_weights2[w]) + h * basist::g_bc7_weights2[w] + 32) >> 6;
		}

		static void eval_weights(
			const color32 *pPixels, uint8_t* pWeights,
			int lr, int lg, int lb,
			int hr, int hg, int hb)
		{
			lr = from_7(lr); lg = from_7(lg); lb = from_7(lb);
			hr = from_7(hr); hg = from_7(hg); hb = from_7(hb);

			int cr[4], cg[4], cb[4];
			for (uint32_t i = 0; i < 4; i++)
			{
				cr[i] = (uint8_t)bc7_interp2(lr, hr, i);
				cg[i] = (uint8_t)bc7_interp2(lg, hg, i);
				cb[i] = (uint8_t)bc7_interp2(lb, hb, i);
			}

#if 0
			for (uint32_t i = 0; i < 16; i++)
			{
				const int pr = pPixels[i].r, pg = pPixels[i].g, pb = pPixels[i].b;

				uint32_t best_err = UINT32_MAX;
				uint32_t best_idx = 0;
				for (uint32_t j = 0; j < 4; j++)
				{
					uint32_t e = square(pr - cr[j]) + square(pg - cg[j]) + square(pb - cb[j]);
					if (e < best_err)
					{
						best_err = e;
						best_idx = j;
					}

					pWeights[i] = (uint8_t)best_idx;
				}
			} // i
#else
			int ar = cr[3] - cr[0], ag = cg[3] - cg[0], ab = cb[3] - cb[0];

			int dots[4];
			for (uint32_t i = 0; i < 4; i++)
				dots[i] = (int)cr[i] * ar + (int)cg[i] * ag + (int)cb[i] * ab;

			// seems very rare in LDR, so rare that it doesn't matter
			//assert(dots[0] <= dots[1]);
			//assert(dots[1] <= dots[2]);
			//assert(dots[2] <= dots[3]);

			int t0 = dots[0] + dots[1], t1 = dots[1] + dots[2], t2 = dots[2] + dots[3];

			ar *= 2; ag *= 2; ab *= 2;

			for (uint32_t i = 0; i < 16; i += 4)
			{
				const int d0 = pPixels[i + 0].r * ar + pPixels[i + 0].g * ag + pPixels[i + 0].b * ab;
				const int d1 = pPixels[i + 1].r * ar + pPixels[i + 1].g * ag + pPixels[i + 1].b * ab;
				const int d2 = pPixels[i + 2].r * ar + pPixels[i + 2].g * ag + pPixels[i + 2].b * ab;
				const int d3 = pPixels[i + 3].r * ar + pPixels[i + 3].g * ag + pPixels[i + 3].b * ab;

				pWeights[i + 0] = (d0 > t0) + (d0 >= t1) + (d0 >= t2);
				pWeights[i + 1] = (d1 > t0) + (d1 >= t1) + (d1 >= t2);
				pWeights[i + 2] = (d2 > t0) + (d2 >= t1) + (d2 >= t2);
				pWeights[i + 3] = (d3 > t0) + (d3 >= t1) + (d3 >= t2);
			}
#endif
		}

		static void pack_bc7_mode5_rgb_block(
			bc7_mode_5* pDst_block,
			int lr, int lg, int lb, int hr, int hg, int hb,
			const uint8_t* pWeights)
		{
			assert((lr >= 0) && (lr <= 127));
			assert((lg >= 0) && (lg <= 127));
			assert((lb >= 0) && (lb <= 127));
			assert((hr >= 0) && (hr <= 127));
			assert((hg >= 0) && (hg <= 127));
			assert((hb >= 0) && (hb <= 127));

			pDst_block->m_lo_bits = 0;

			uint8_t weight_inv = 0;
			if (pWeights[0] & 2)
			{
				std::swap(lr, hr);
				std::swap(lg, hg);
				std::swap(lb, hb);
				weight_inv = 3;
			}
			assert((pWeights[0] ^ weight_inv) <= 1);

			pDst_block->m_lo.m_mode = 32;
			pDst_block->m_lo.m_r0 = lr;
			pDst_block->m_lo.m_r1 = hr;
			pDst_block->m_lo.m_g0 = lg;
			pDst_block->m_lo.m_g1 = hg;
			pDst_block->m_lo.m_b0 = lb;
			pDst_block->m_lo.m_b1 = hb;

			pDst_block->m_lo.m_a0 = 255;
			pDst_block->m_lo.m_a1_0 = 63;

			uint64_t sel_bits = 3;
			uint32_t cur_ofs = 2;
			for (uint32_t i = 0; i < 16; i++)
			{
				assert(pWeights[i] <= 3);
				sel_bits |= ((uint64_t)(weight_inv ^ pWeights[i])) << cur_ofs;
				cur_ofs += (i ? 2 : 1);
			}

			pDst_block->m_hi_bits = sel_bits;
		}

		// This table is: 9 * (w * w), 9 * ((1.0f - w) * w), 9 * ((1.0f - w) * (1.0f - w))
		// where w is [0,1/3,2/3,1]. 9 is the perfect multiplier.
		static const uint32_t g_weight_vals4[4] = { 0x000009, 0x010204, 0x040201, 0x090000 };

		static inline bool compute_least_squares_endpoints4_rgb(
			const color32 *pColors, const uint8_t* pSelectors,
			int& lr, int& lg, int& lb, int& hr, int& hg, int& hb,
			int total_r, int total_g, int total_b)
		{
			uint32_t uq00_r = 0, uq00_g = 0, uq00_b = 0;
			uint32_t weight_accum = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				const uint8_t r = pColors[i].r, g = pColors[i].g, b = pColors[i].b;
				const uint8_t sel = pSelectors[i];

				weight_accum += g_weight_vals4[sel];
				uq00_r += sel * r;
				uq00_g += sel * g;
				uq00_b += sel * b;
			}

			int q10_r = total_r * 3 - uq00_r;
			int q10_g = total_g * 3 - uq00_g;
			int q10_b = total_b * 3 - uq00_b;

			float z00 = (float)((weight_accum >> 16) & 0xFF);
			float z10 = (float)((weight_accum >> 8) & 0xFF);
			float z11 = (float)(weight_accum & 0xFF);
			float z01 = z10;

			float det = z00 * z11 - z01 * z10;
			if (fabs(det) < 1e-8f)
				return false;

			det = (3.0f / 255.0f) / det;

			float iz00, iz01, iz10, iz11;
			iz00 = z11 * det;
			iz01 = -z01 * det;
			iz10 = -z10 * det;
			iz11 = z00 * det;

			float fhr = basisu::clamp(iz00 * (float)uq00_r + iz01 * q10_r, 0.0f, 1.0f);
			float flr = basisu::clamp(iz10 * (float)uq00_r + iz11 * q10_r, 0.0f, 1.0f);

			float fhg = basisu::clamp(iz00 * (float)uq00_g + iz01 * q10_g, 0.0f, 1.0f);
			float flg = basisu::clamp(iz10 * (float)uq00_g + iz11 * q10_g, 0.0f, 1.0f);

			float fhb = basisu::clamp(iz00 * (float)uq00_b + iz01 * q10_b, 0.0f, 1.0f);
			float flb = basisu::clamp(iz10 * (float)uq00_b + iz11 * q10_b, 0.0f, 1.0f);

			lr = to_7(flr); lg = to_7(flg); lb = to_7(flb);
			hr = to_7(fhr); hg = to_7(fhg); hb = to_7(fhb);

			return true;
		}

		void encode_bc7_mode_5_block(void* pDst_block, color32* pPixels, bool hq_mode)
		{
			assert(g_mode5_rgba_midpoints[1]);

			int total_r = 0, total_g = 0, total_b = 0;

			int min_r = 255, min_g = 255, min_b = 255;
			int max_r = 0, max_g = 0, max_b = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;

				total_r += r; total_g += g; total_b += b;

				min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
				max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
			}

			if ((min_r == max_r) && (min_g == max_g) && (min_b == max_b))
			{
				const int lr = g_bc7_m5_equals_1[min_r].m_lo, lg = g_bc7_m5_equals_1[min_g].m_lo, lb = g_bc7_m5_equals_1[min_b].m_lo;
				const int hr = g_bc7_m5_equals_1[min_r].m_hi, hg = g_bc7_m5_equals_1[min_g].m_hi, hb = g_bc7_m5_equals_1[min_b].m_hi;
				uint8_t solid_weights[16];
				memset(solid_weights, 1, 16);
				pack_bc7_mode5_rgb_block((bc7_mode_5*)pDst_block, lr, lg, lb, hr, hg, hb, solid_weights);
				return;
			}

			int mean_r = (total_r + 8) >> 4, mean_g = (total_g + 8) >> 4, mean_b = (total_b + 8) >> 4;

			// covar rows are:
			// 0, 1, 2
			// 1, 3, 4
			// 2, 4, 5
			int icov[6] = { 0, 0, 0, 0, 0, 0 };

			for (uint32_t i = 0; i < 16; i++)
			{
				int r = (int)pPixels[i].r - mean_r;
				int g = (int)pPixels[i].g - mean_g;
				int b = (int)pPixels[i].b - mean_b;
				icov[0] += r * r; icov[1] += r * g; icov[2] += r * b;
				icov[3] += g * g; icov[4] += g * b;
				icov[5] += b * b;
			}

			int block_max_var = basisu::maximum(icov[0], icov[3], icov[5]); // not divided by 16, i.e. scaled by 16
			
			// TODO: Tune this
			const int32_t SIMPLE_BLOCK_THRESH = 10 * 16;
						
			if ((!hq_mode) && (block_max_var < SIMPLE_BLOCK_THRESH))
			{
				const int L = 16, H = 239;

				int lr = to_7(lerp_8bit(min_r, max_r, L));
				int lg = to_7(lerp_8bit(min_g, max_g, L));
				int lb = to_7(lerp_8bit(min_b, max_b, L));

				int hr = to_7(lerp_8bit(min_r, max_r, H));
				int hg = to_7(lerp_8bit(min_g, max_g, H));
				int hb = to_7(lerp_8bit(min_b, max_b, H));

				uint8_t cur_weights[16];
				eval_weights(pPixels, cur_weights, lr, lg, lb, hr, hg, hb);

				pack_bc7_mode5_rgb_block((bc7_mode_5*)pDst_block, lr, lg, lb, hr, hg, hb, cur_weights);
				return;
			}

			float cov[6];
			for (uint32_t i = 0; i < 6; i++)
				cov[i] = (float)icov[i];

			const float sc = 1.0f / (float)block_max_var;
			const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

			const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
			const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
			const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

			int saxis_r = 306, saxis_g = 601, saxis_b = 117;

			float k = basisu::maximum(fabsf(alt_xr), fabsf(alt_xg), fabsf(alt_xb));
			if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
			{
				float m = 2048.0f / k;
				saxis_r = (int)(alt_xr * m);
				saxis_g = (int)(alt_xg * m);
				saxis_b = (int)(alt_xb * m);
			}
						
			saxis_r = (int)((uint32_t)saxis_r << 4U);
			saxis_g = (int)((uint32_t)saxis_g << 4U);
			saxis_b = (int)((uint32_t)saxis_b << 4U);

			int low_dot = INT_MAX, high_dot = INT_MIN;

			for (uint32_t i = 0; i < 16; i += 4)
			{
				int dot0 = ((pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) & ~0xF) + i;
				int dot1 = ((pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b) & ~0xF) + i + 1;
				int dot2 = ((pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b) & ~0xF) + i + 2;
				int dot3 = ((pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b) & ~0xF) + i + 3;

				int min_d01 = basisu::minimum(dot0, dot1);
				int max_d01 = basisu::maximum(dot0, dot1);

				int min_d23 = basisu::minimum(dot2, dot3);
				int max_d23 = basisu::maximum(dot2, dot3);

				int min_d = basisu::minimum(min_d01, min_d23);
				int max_d = basisu::maximum(max_d01, max_d23);

				low_dot = basisu::minimum(low_dot, min_d);
				high_dot = basisu::maximum(high_dot, max_d);
			}
			int low_c = low_dot & 15;
			int high_c = high_dot & 15;

			int lr = to_7(pPixels[low_c].r), lg = to_7(pPixels[low_c].g), lb = to_7(pPixels[low_c].b);
			int hr = to_7(pPixels[high_c].r), hg = to_7(pPixels[high_c].g), hb = to_7(pPixels[high_c].b);

			uint8_t cur_weights[16];
			eval_weights(pPixels, cur_weights, lr, lg, lb, hr, hg, hb);

			if (compute_least_squares_endpoints4_rgb(
				pPixels, cur_weights,
				lr, lg, lb, hr, hg, hb,
				total_r, total_g, total_b))
			{
				eval_weights(pPixels, cur_weights, lr, lg, lb, hr, hg, hb);
			}

#if 0
			lr = 0; lg = 0; lb = 0;
			hr = 0; hg = 0; hb = 0;
#endif

			pack_bc7_mode5_rgb_block((bc7_mode_5*)pDst_block, lr, lg, lb, hr, hg, hb, cur_weights);
		}

	} // namespace bc7_mode_5_encoder

#endif // BASISD_SUPPORT_BC7_MODE5

	//------------------------------------------------------------------------------------------------

	basisu_lowlevel_etc1s_transcoder::basisu_lowlevel_etc1s_transcoder() :
		m_pGlobal_codebook(nullptr),
		m_selector_history_buf_size(0)
	{
	}

	bool basisu_lowlevel_etc1s_transcoder::decode_palettes(
		uint32_t num_endpoints, const uint8_t* pEndpoints_data, uint32_t endpoints_data_size,
		uint32_t num_selectors, const uint8_t* pSelectors_data, uint32_t selectors_data_size)
	{
		if (m_pGlobal_codebook)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 11\n");
			return false;
		}
		bitwise_decoder sym_codec;

		huffman_decoding_table color5_delta_model0, color5_delta_model1, color5_delta_model2, inten_delta_model;

		if (!sym_codec.init(pEndpoints_data, endpoints_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 0\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(color5_delta_model0))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 1\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(color5_delta_model1))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 1a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(color5_delta_model2))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 2a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(inten_delta_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 2b\n");
			return false;
		}

		if (!color5_delta_model0.is_valid() || !color5_delta_model1.is_valid() || !color5_delta_model2.is_valid() || !inten_delta_model.is_valid())
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 2b\n");
			return false;
		}

		const bool endpoints_are_grayscale = sym_codec.get_bits(1) != 0;

		m_local_endpoints.resize(num_endpoints);

		color32 prev_color5(16, 16, 16, 0);
		uint32_t prev_inten = 0;

		for (uint32_t i = 0; i < num_endpoints; i++)
		{
			uint32_t inten_delta = sym_codec.decode_huffman(inten_delta_model);
			m_local_endpoints[i].m_inten5 = static_cast<uint8_t>((inten_delta + prev_inten) & 7);
			prev_inten = m_local_endpoints[i].m_inten5;

			for (uint32_t c = 0; c < (endpoints_are_grayscale ? 1U : 3U); c++)
			{
				int delta;
				if (prev_color5[c] <= basist::COLOR5_PAL0_PREV_HI)
					delta = sym_codec.decode_huffman(color5_delta_model0);
				else if (prev_color5[c] <= basist::COLOR5_PAL1_PREV_HI)
					delta = sym_codec.decode_huffman(color5_delta_model1);
				else
					delta = sym_codec.decode_huffman(color5_delta_model2);

				int v = (prev_color5[c] + delta) & 31;

				m_local_endpoints[i].m_color5[c] = static_cast<uint8_t>(v);

				prev_color5[c] = static_cast<uint8_t>(v);
			}

			if (endpoints_are_grayscale)
			{
				m_local_endpoints[i].m_color5[1] = m_local_endpoints[i].m_color5[0];
				m_local_endpoints[i].m_color5[2] = m_local_endpoints[i].m_color5[0];
			}
		}

		sym_codec.stop();

		m_local_selectors.resize(num_selectors);
		
		if (!sym_codec.init(pSelectors_data, selectors_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 5\n");
			return false;
		}

		basist::huffman_decoding_table delta_selector_pal_model;

		const bool used_global_selector_cb = (sym_codec.get_bits(1) == 1);

		if (used_global_selector_cb)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: global selector codebooks are unsupported\n");
			return false;
		}
		else
		{
			const bool used_hybrid_selector_cb = (sym_codec.get_bits(1) == 1);

			if (used_hybrid_selector_cb)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: hybrid global selector codebooks are unsupported\n");
				return false;
			}
				
			const bool used_raw_encoding = (sym_codec.get_bits(1) == 1);

			if (used_raw_encoding)
			{
				for (uint32_t i = 0; i < num_selectors; i++)
				{
					for (uint32_t j = 0; j < 4; j++)
					{
						uint32_t cur_byte = sym_codec.get_bits(8);

						for (uint32_t k = 0; k < 4; k++)
							m_local_selectors[i].set_selector(k, j, (cur_byte >> (k * 2)) & 3);
					}

					m_local_selectors[i].init_flags();
				}
			}
			else
			{
				if (!sym_codec.read_huffman_table(delta_selector_pal_model))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 10\n");
					return false;
				}

				if ((num_selectors > 1) && (!delta_selector_pal_model.is_valid()))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_palettes: fail 10a\n");
					return false;
				}

				uint8_t prev_bytes[4] = { 0, 0, 0, 0 };

				for (uint32_t i = 0; i < num_selectors; i++)
				{
					if (!i)
					{
						for (uint32_t j = 0; j < 4; j++)
						{
							uint32_t cur_byte = sym_codec.get_bits(8);
							prev_bytes[j] = static_cast<uint8_t>(cur_byte);

							for (uint32_t k = 0; k < 4; k++)
								m_local_selectors[i].set_selector(k, j, (cur_byte >> (k * 2)) & 3);
						}
						m_local_selectors[i].init_flags();
						continue;
					}

					for (uint32_t j = 0; j < 4; j++)
					{
						int delta_byte = sym_codec.decode_huffman(delta_selector_pal_model);

						uint32_t cur_byte = delta_byte ^ prev_bytes[j];
						prev_bytes[j] = static_cast<uint8_t>(cur_byte);

						for (uint32_t k = 0; k < 4; k++)
							m_local_selectors[i].set_selector(k, j, (cur_byte >> (k * 2)) & 3);
					}
					m_local_selectors[i].init_flags();
				}
			}
		}

		sym_codec.stop();

		return true;
	}

	bool basisu_lowlevel_etc1s_transcoder::decode_tables(const uint8_t* pTable_data, uint32_t table_data_size)
	{
		basist::bitwise_decoder sym_codec;
		if (!sym_codec.init(pTable_data, table_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 0\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_endpoint_pred_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 1\n");
			return false;
		}

		if (m_endpoint_pred_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 1a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_delta_endpoint_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 2\n");
			return false;
		}

		if (m_delta_endpoint_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 2a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_selector_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 3\n");
			return false;
		}

		if (m_selector_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 3a\n");
			return false;
		}

		if (!sym_codec.read_huffman_table(m_selector_history_buf_rle_model))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 4\n");
			return false;
		}

		if (m_selector_history_buf_rle_model.get_code_sizes().size() == 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 4a\n");
			return false;
		}

		m_selector_history_buf_size = sym_codec.get_bits(13);
		// Check for bogus values.
		if (!m_selector_history_buf_size)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::decode_tables: fail 5\n");
			return false;
		}

		sym_codec.stop();

		return true;
	}

	bool basisu_lowlevel_etc1s_transcoder::transcode_slice(void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, const bool is_video, const bool is_alpha_slice, const uint32_t level_index, const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, bool transcode_alpha, void *pAlpha_blocks, uint32_t output_rows_in_pixels, uint32_t decode_flags)
	{
		// 'pDst_blocks' unused when disabling *all* hardware transcode options
		// (and 'bc1_allow_threecolor_blocks' when disabling DXT)
		BASISU_NOTE_UNUSED(pDst_blocks);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(transcode_alpha);
		BASISU_NOTE_UNUSED(pAlpha_blocks);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

		if (!pState)
			pState = &m_def_state;

		const uint32_t total_blocks = num_blocks_x * num_blocks_y;

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
			{
				if (fmt == block_format::cFXT1_RGB)
					output_row_pitch_in_blocks_or_pixels = (orig_width + 7) / 8;
				else
					output_row_pitch_in_blocks_or_pixels = num_blocks_x;
			}
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}
		
		basisu::vector<uint32_t>* pPrev_frame_indices = nullptr;
		if (is_video)
		{
			// TODO: Add check to make sure the caller hasn't tried skipping past p-frames
			//const bool alpha_flag = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;
			//const uint32_t level_index = slice_desc.m_level_index;

			if (level_index >= basisu_transcoder_state::cMaxPrevFrameLevels)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: unsupported level_index\n");
				return false;
			}

			pPrev_frame_indices = &pState->m_prev_frame_indices[is_alpha_slice][level_index];
			if (pPrev_frame_indices->size() < total_blocks)
				pPrev_frame_indices->resize(total_blocks);
		}

		basist::bitwise_decoder sym_codec;

		if (!sym_codec.init(pImage_data, image_data_size))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: sym_codec.init failed\n");
			return false;
		}

		approx_move_to_front selector_history_buf(m_selector_history_buf_size);
				
		uint32_t cur_selector_rle_count = 0;

		decoder_etc_block block;
		memset(&block, 0, sizeof(block));
				
		//block.set_flip_bit(true);
		// Setting the flip bit to false to be compatible with the Khronos KDFS.
		block.set_flip_bit(false);

		block.set_diff_bit(true);

		// Important: This MUST be freed before this function returns.
		void* pPVRTC_work_mem = nullptr;
		uint32_t* pPVRTC_endpoints = nullptr;
		if ((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA))
		{
			//pPVRTC_work_mem = malloc(num_blocks_x * num_blocks_y * (sizeof(decoder_etc_block) + sizeof(uint32_t)));
			const uint64_t alloc_size = (uint64_t)num_blocks_x * (uint64_t)num_blocks_y * (sizeof(decoder_etc_block) + sizeof(uint32_t));
			if (alloc_size > (256u * 1024u * 1024u)) // sanity check, 16384x16384=192MB
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: malloc would be too large\n");
				return false;
			}

			pPVRTC_work_mem = malloc(alloc_size);

			if (!pPVRTC_work_mem)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: malloc failed\n");
				return false;
			}
			pPVRTC_endpoints = (uint32_t*)&((decoder_etc_block*)pPVRTC_work_mem)[num_blocks_x * num_blocks_y];
		}

		if (pState->m_block_endpoint_preds[0].size() < num_blocks_x)
		{
			pState->m_block_endpoint_preds[0].resize(num_blocks_x);
			pState->m_block_endpoint_preds[1].resize(num_blocks_x);
		}

		uint32_t cur_pred_bits = 0;
		int prev_endpoint_pred_sym = 0;
		int endpoint_pred_repeat_count = 0;
		uint32_t prev_endpoint_index = 0;
		const endpoint_vec& endpoints = m_pGlobal_codebook ? m_pGlobal_codebook->m_local_endpoints : m_local_endpoints;
		const selector_vec& selectors = m_pGlobal_codebook ? m_pGlobal_codebook->m_local_selectors : m_local_selectors;
		if (!endpoints.size() || !selectors.size())
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: global codebooks must be unpacked first\n");
			
			if (pPVRTC_work_mem)
				free(pPVRTC_work_mem);

			return false;
		}

		const uint32_t SELECTOR_HISTORY_BUF_FIRST_SYMBOL_INDEX = (uint32_t)selectors.size();
		const uint32_t SELECTOR_HISTORY_BUF_RLE_SYMBOL_INDEX = m_selector_history_buf_size + SELECTOR_HISTORY_BUF_FIRST_SYMBOL_INDEX;

#if BASISD_SUPPORT_BC7_MODE5
		const bool bc7_chroma_filtering = ((decode_flags & cDecodeFlagsNoETC1SChromaFiltering) == 0) && 
			((fmt == block_format::cBC7_M5_COLOR) || (fmt == block_format::cBC7));

		basisu::vector2D<uint16_t> decoded_endpoints;
		if (bc7_chroma_filtering)
		{
			if (!decoded_endpoints.try_resize(num_blocks_x, num_blocks_y))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: allocation failed\n");

				if (pPVRTC_work_mem)
					free(pPVRTC_work_mem);

				return false;
			}
		}
#endif

		for (uint32_t block_y = 0; block_y < num_blocks_y; block_y++)
		{
			const uint32_t cur_block_endpoint_pred_array = block_y & 1;

			for (uint32_t block_x = 0; block_x < num_blocks_x; block_x++)
			{
				// Decode endpoint index predictor symbols
				if ((block_x & 1) == 0)
				{
					if ((block_y & 1) == 0)
					{
						if (endpoint_pred_repeat_count)
						{
							endpoint_pred_repeat_count--;
							cur_pred_bits = prev_endpoint_pred_sym;
						}
						else
						{
							cur_pred_bits = sym_codec.decode_huffman(m_endpoint_pred_model);
							if (cur_pred_bits == ENDPOINT_PRED_REPEAT_LAST_SYMBOL)
							{
								endpoint_pred_repeat_count = sym_codec.decode_vlc(ENDPOINT_PRED_COUNT_VLC_BITS) + ENDPOINT_PRED_MIN_REPEAT_COUNT - 1;

								cur_pred_bits = prev_endpoint_pred_sym;
							}
							else
							{
								prev_endpoint_pred_sym = cur_pred_bits;
							}
						}

						pState->m_block_endpoint_preds[cur_block_endpoint_pred_array ^ 1][block_x].m_pred_bits = (uint8_t)(cur_pred_bits >> 4);
					}
					else
					{
						cur_pred_bits = pState->m_block_endpoint_preds[cur_block_endpoint_pred_array][block_x].m_pred_bits;
					}
				}

				// Decode endpoint index
				uint32_t endpoint_index, selector_index = 0;

				const uint32_t pred = cur_pred_bits & 3;
				cur_pred_bits >>= 2;

				if (pred == 0)
				{
					// Left
					if (!block_x)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (0)\n");
						if (pPVRTC_work_mem)
							free(pPVRTC_work_mem);
						return false;
					}

					endpoint_index = prev_endpoint_index;
				}
				else if (pred == 1)
				{
					// Upper
					if (!block_y)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (1)\n");
						if (pPVRTC_work_mem)
							free(pPVRTC_work_mem);
						return false;
					}

					endpoint_index = pState->m_block_endpoint_preds[cur_block_endpoint_pred_array ^ 1][block_x].m_endpoint_index;
				}
				else if (pred == 2)
				{
					if (is_video)
					{
						assert(pred == CR_ENDPOINT_PRED_INDEX);
						endpoint_index = (*pPrev_frame_indices)[block_x + block_y * num_blocks_x];
						selector_index = endpoint_index >> 16;
						endpoint_index &= 0xFFFFU;
					}
					else
					{
						// Upper left
						if ((!block_x) || (!block_y))
						{
							BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (2)\n");
							if (pPVRTC_work_mem)
								free(pPVRTC_work_mem);
							return false;
						}

						endpoint_index = pState->m_block_endpoint_preds[cur_block_endpoint_pred_array ^ 1][block_x - 1].m_endpoint_index;
					}
				}
				else
				{
					// Decode and apply delta
					const uint32_t delta_sym = sym_codec.decode_huffman(m_delta_endpoint_model);

					endpoint_index = delta_sym + prev_endpoint_index;
					if (endpoint_index >= endpoints.size())
						endpoint_index -= (int)endpoints.size();
				}

				pState->m_block_endpoint_preds[cur_block_endpoint_pred_array][block_x].m_endpoint_index = (uint16_t)endpoint_index;

				prev_endpoint_index = endpoint_index;

				// Decode selector index
				if ((!is_video) || (pred != CR_ENDPOINT_PRED_INDEX))
				{
					int selector_sym;
					if (cur_selector_rle_count > 0)
					{
						cur_selector_rle_count--;

						selector_sym = (int)selectors.size();
					}
					else
					{
						selector_sym = sym_codec.decode_huffman(m_selector_model);

						if (selector_sym == static_cast<int>(SELECTOR_HISTORY_BUF_RLE_SYMBOL_INDEX))
						{
							int run_sym = sym_codec.decode_huffman(m_selector_history_buf_rle_model);

							if (run_sym == (SELECTOR_HISTORY_BUF_RLE_COUNT_TOTAL - 1))
								cur_selector_rle_count = sym_codec.decode_vlc(7) + SELECTOR_HISTORY_BUF_RLE_COUNT_THRESH;
							else
								cur_selector_rle_count = run_sym + SELECTOR_HISTORY_BUF_RLE_COUNT_THRESH;

							if (cur_selector_rle_count > total_blocks)
							{
								// The file is corrupted or we've got a bug.
								BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (3)\n");
								if (pPVRTC_work_mem)
									free(pPVRTC_work_mem);
								return false;
							}

							selector_sym = (int)selectors.size();

							cur_selector_rle_count--;
						}
					}

					if (selector_sym >= (int)selectors.size())
					{
						assert(m_selector_history_buf_size > 0);

						int history_buf_index = selector_sym - (int)selectors.size();

						if (history_buf_index >= (int)selector_history_buf.size())
						{
							// The file is corrupted or we've got a bug.
							BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (4)\n");
							if (pPVRTC_work_mem)
								free(pPVRTC_work_mem);
							return false;
						}

						selector_index = selector_history_buf[history_buf_index];

						if (history_buf_index != 0)
							selector_history_buf.use(history_buf_index);
					}
					else
					{
						selector_index = selector_sym;

						if (m_selector_history_buf_size)
							selector_history_buf.add(selector_index);
					}
				}

				if ((endpoint_index >= endpoints.size()) || (selector_index >= selectors.size()))
				{
					// The file is corrupted or we've got a bug.
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: invalid datastream (5)\n");
					if (pPVRTC_work_mem)
						free(pPVRTC_work_mem);
					return false;
				}

				if (is_video)
					(*pPrev_frame_indices)[block_x + block_y * num_blocks_x] = endpoint_index | (selector_index << 16);

#if BASISD_ENABLE_DEBUG_FLAGS
				if ((g_debug_flags & cDebugFlagVisCRs) && ((fmt == block_format::cETC1) || (fmt == block_format::cBC1)))
				{
					if ((is_video) && (pred == 2))
					{
						decoder_etc_block* pDst_block = reinterpret_cast<decoder_etc_block*>(static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes);
						memset(pDst_block, 0xFF, 8);
						continue;
					}
				}
#endif

				const endpoint* pEndpoints = &endpoints[endpoint_index];
				const selector* pSelector = &selectors[selector_index];

				switch (fmt)
				{
				case block_format::cETC1:
				{
					decoder_etc_block* pDst_block = reinterpret_cast<decoder_etc_block*>(static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes);
					
					block.set_base5_color(decoder_etc_block::pack_color5(pEndpoints->m_color5, false));
					block.set_inten_table(0, pEndpoints->m_inten5);
					block.set_inten_table(1, pEndpoints->m_inten5);

					pDst_block->m_uint32[0] = block.m_uint32[0];
					pDst_block->set_raw_selector_bits(pSelector->m_bytes[0], pSelector->m_bytes[1], pSelector->m_bytes[2], pSelector->m_bytes[3]);

					break;
				}
				case block_format::cBC1:
				{
#if BASISD_SUPPORT_DXT1
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
#if BASISD_ENABLE_DEBUG_FLAGS
					if (g_debug_flags & (cDebugFlagVisBC1Sels | cDebugFlagVisBC1Endpoints))
						convert_etc1s_to_dxt1_vis(static_cast<dxt1_block*>(pDst_block), pEndpoints, pSelector, bc1_allow_threecolor_blocks);
					else
#endif
						convert_etc1s_to_dxt1(static_cast<dxt1_block*>(pDst_block), pEndpoints, pSelector, bc1_allow_threecolor_blocks);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cBC4:
				{
#if BASISD_SUPPORT_DXT5A
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_dxt5a(static_cast<dxt5a_block*>(pDst_block), pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cPVRTC1_4_RGB:
				{
#if BASISD_SUPPORT_PVRTC1
					block.set_base5_color(decoder_etc_block::pack_color5(pEndpoints->m_color5, false));
					block.set_inten_table(0, pEndpoints->m_inten5);
					block.set_inten_table(1, pEndpoints->m_inten5);
					block.set_raw_selector_bits(pSelector->m_bytes[0], pSelector->m_bytes[1], pSelector->m_bytes[2], pSelector->m_bytes[3]);

					((decoder_etc_block*)pPVRTC_work_mem)[block_x + block_y * num_blocks_x] = block;

					const color32& base_color = pEndpoints->m_color5;
					const uint32_t inten_table = pEndpoints->m_inten5;

					const uint32_t low_selector = pSelector->m_lo_selector;
					const uint32_t high_selector = pSelector->m_hi_selector;

					// Get block's RGB bounding box 
					color32 block_colors[2];
					decoder_etc_block::get_block_colors5_bounds(block_colors, base_color, inten_table, low_selector, high_selector);

					assert(block_colors[0][0] <= block_colors[1][0]);
					assert(block_colors[0][1] <= block_colors[1][1]);
					assert(block_colors[0][2] <= block_colors[1][2]);

					// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
					pvrtc4_block temp;
					temp.set_opaque_endpoint_floor(0, block_colors[0]);
					temp.set_opaque_endpoint_ceil(1, block_colors[1]);

					pPVRTC_endpoints[block_x + block_y * num_blocks_x] = temp.m_endpoints;
#else
					assert(0);
#endif	

					break;
				}
				case block_format::cPVRTC1_4_RGBA:
				{
#if BASISD_SUPPORT_PVRTC1
					assert(pAlpha_blocks);
					
					block.set_base5_color(decoder_etc_block::pack_color5(pEndpoints->m_color5, false));
					block.set_inten_table(0, pEndpoints->m_inten5);
					block.set_inten_table(1, pEndpoints->m_inten5);
					block.set_raw_selector_bits(pSelector->m_selectors[0], pSelector->m_selectors[1], pSelector->m_selectors[2], pSelector->m_selectors[3]);

					((decoder_etc_block*)pPVRTC_work_mem)[block_x + block_y * num_blocks_x] = block;

					// Get block's RGBA bounding box 
					const color32& base_color = pEndpoints->m_color5;
					const uint32_t inten_table = pEndpoints->m_inten5;
					const uint32_t low_selector = pSelector->m_lo_selector;
					const uint32_t high_selector = pSelector->m_hi_selector;
					color32 block_colors[2];
					decoder_etc_block::get_block_colors5_bounds(block_colors, base_color, inten_table, low_selector, high_selector);

					assert(block_colors[0][0] <= block_colors[1][0]);
					assert(block_colors[0][1] <= block_colors[1][1]);
					assert(block_colors[0][2] <= block_colors[1][2]);

					const uint16_t* pAlpha_block = reinterpret_cast<uint16_t*>(static_cast<uint8_t*>(pAlpha_blocks) + (block_x + block_y * num_blocks_x) * sizeof(uint32_t));

					const endpoint* pAlpha_endpoints = &endpoints[pAlpha_block[0]];
					const selector* pAlpha_selector = &selectors[pAlpha_block[1]];

					const color32& alpha_base_color = pAlpha_endpoints->m_color5;
					const uint32_t alpha_inten_table = pAlpha_endpoints->m_inten5;
					const uint32_t alpha_low_selector = pAlpha_selector->m_lo_selector;
					const uint32_t alpha_high_selector = pAlpha_selector->m_hi_selector;
					uint32_t alpha_block_colors[2];
					decoder_etc_block::get_block_colors5_bounds_g(alpha_block_colors, alpha_base_color, alpha_inten_table, alpha_low_selector, alpha_high_selector);
					assert(alpha_block_colors[0] <= alpha_block_colors[1]);
					block_colors[0].a = (uint8_t)alpha_block_colors[0];
					block_colors[1].a = (uint8_t)alpha_block_colors[1];

					// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
					pvrtc4_block temp;
					temp.set_endpoint_floor(0, block_colors[0]);
					temp.set_endpoint_ceil(1, block_colors[1]);

					pPVRTC_endpoints[block_x + block_y * num_blocks_x] = temp.m_endpoints;
#else
					assert(0);
#endif	

					break;
				}
				case block_format::cBC7:				// for more consistency with UASTC
				case block_format::cBC7_M5_COLOR:
				{
#if BASISD_SUPPORT_BC7_MODE5
					if (bc7_chroma_filtering)
					{
						assert(endpoint_index <= UINT16_MAX);
						decoded_endpoints(block_x, block_y) = (uint16_t)endpoint_index;
					}

					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_bc7_m5_color(pDst_block, pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cBC7_M5_ALPHA:
				{
#if BASISD_SUPPORT_BC7_MODE5
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_bc7_m5_alpha(pDst_block, pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cETC2_EAC_A8:
				{
#if BASISD_SUPPORT_ETC2_EAC_A8
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_etc2_eac_a8(static_cast<eac_block*>(pDst_block), pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cASTC_LDR_4x4:
				{
#if BASISD_SUPPORT_ASTC
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_astc_4x4(pDst_block, pEndpoints, pSelector, transcode_alpha, &endpoints[0], &selectors[0]);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cATC_RGB:
				{
#if BASISD_SUPPORT_ATC
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_atc(pDst_block, pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cFXT1_RGB:
				{
#if BASISD_SUPPORT_FXT1
					const uint32_t fxt1_block_x = block_x >> 1;
					const uint32_t fxt1_block_y = block_y;
					const uint32_t fxt1_subblock = block_x & 1;

					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (fxt1_block_x + fxt1_block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;

					convert_etc1s_to_fxt1(pDst_block, pEndpoints, pSelector, fxt1_subblock);
#else
					assert(0);
#endif
					break;
				}
				case block_format::cPVRTC2_4_RGB:
				{
#if BASISD_SUPPORT_PVRTC2
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_pvrtc2_rgb(pDst_block, pEndpoints, pSelector);
#endif
					break;
				}
				case block_format::cPVRTC2_4_RGBA:
				{
#if BASISD_SUPPORT_PVRTC2
					assert(transcode_alpha);

					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
										
					convert_etc1s_to_pvrtc2_rgba(pDst_block, pEndpoints, pSelector, &endpoints[0], &selectors[0]);
#endif
					break;
				}
				case block_format::cIndices:
				{
					uint16_t* pDst_block = reinterpret_cast<uint16_t *>(static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes);
					pDst_block[0] = static_cast<uint16_t>(endpoint_index);
					pDst_block[1] = static_cast<uint16_t>(selector_index);
					break;
				}
				case block_format::cA32:
				{
					assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);
										
					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);
					
					int colors[4];
					decoder_etc_block::get_block_colors5_g(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					if (max_x == 4)
					{
						for (uint32_t y = 0; y < max_y; y++)
						{
							const uint32_t s = pSelector->m_selectors[y];

							pDst_pixels[3] = static_cast<uint8_t>(colors[s & 3]);
							pDst_pixels[3+4] = static_cast<uint8_t>(colors[(s >> 2) & 3]);
							pDst_pixels[3+8] = static_cast<uint8_t>(colors[(s >> 4) & 3]);
							pDst_pixels[3+12] = static_cast<uint8_t>(colors[(s >> 6) & 3]);
							
							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
						}
					}
					else
					{
						for (uint32_t y = 0; y < max_y; y++)
						{
							const uint32_t s = pSelector->m_selectors[y];

							for (uint32_t x = 0; x < max_x; x++)
								pDst_pixels[3 + 4 * x] = static_cast<uint8_t>(colors[(s >> (x * 2)) & 3]);

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
						}
					}

					break;
				}
				case block_format::cRGB32:
				{
					assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);
					
					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							const color32& c = colors[(s >> (x * 2)) & 3];

							pDst_pixels[0 + 4 * x] = c.r;
							pDst_pixels[1 + 4 * x] = c.g;
							pDst_pixels[2 + 4 * x] = c.b;
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
					}

					break;
				}
				case block_format::cRGBA32:
				{
					assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							const color32& c = colors[(s >> (x * 2)) & 3];

							pDst_pixels[0 + 4 * x] = c.r;
							pDst_pixels[1 + 4 * x] = c.g;
							pDst_pixels[2 + 4 * x] = c.b;
							pDst_pixels[3 + 4 * x] = 255;
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
					}

					break;
				}
				case block_format::cRGB565:
				case block_format::cBGR565:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					if (fmt == block_format::cRGB565)
					{
						for (uint32_t i = 0; i < 4; i++)
						{
							packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].r, 31) << 11) | (mul_8(colors[i].g, 63) << 5) | mul_8(colors[i].b, 31));
							if (BASISD_IS_BIG_ENDIAN)
								packed_colors[i] = byteswap_uint16(packed_colors[i]);
						}
					}
					else
					{
						for (uint32_t i = 0; i < 4; i++)
						{
							packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].b, 31) << 11) | (mul_8(colors[i].g, 63) << 5) | mul_8(colors[i].r, 31));
							if (BASISD_IS_BIG_ENDIAN)
								packed_colors[i] = byteswap_uint16(packed_colors[i]);
						}
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
							reinterpret_cast<uint16_t *>(pDst_pixels)[x] = packed_colors[(s >> (x * 2)) & 3];

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cRGBA4444_COLOR:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					for (uint32_t i = 0; i < 4; i++)
					{
						packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].r, 15) << 12) | (mul_8(colors[i].g, 15) << 8) | (mul_8(colors[i].b, 15) << 4));
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							uint16_t cur = reinterpret_cast<uint16_t*>(pDst_pixels)[x];
							if (BASISD_IS_BIG_ENDIAN)
								cur = byteswap_uint16(cur);

							cur = (cur & 0xF) | packed_colors[(s >> (x * 2)) & 3];
							
							if (BASISD_IS_BIG_ENDIAN)
								cur = byteswap_uint16(cur);

							reinterpret_cast<uint16_t*>(pDst_pixels)[x] = cur;
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cRGBA4444_COLOR_OPAQUE:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					for (uint32_t i = 0; i < 4; i++)
					{
						packed_colors[i] = static_cast<uint16_t>((mul_8(colors[i].r, 15) << 12) | (mul_8(colors[i].g, 15) << 8) | (mul_8(colors[i].b, 15) << 4) | 0xF);
						if (BASISD_IS_BIG_ENDIAN)
							packed_colors[i] = byteswap_uint16(packed_colors[i]);
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
							reinterpret_cast<uint16_t*>(pDst_pixels)[x] = packed_colors[(s >> (x * 2)) & 3];

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cRGBA4444_ALPHA:
				{
					assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
					uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

					const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
					const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

					color32 colors[4];
					decoder_etc_block::get_block_colors5(colors, pEndpoints->m_color5, pEndpoints->m_inten5);

					uint16_t packed_colors[4];
					for (uint32_t i = 0; i < 4; i++)
					{
						packed_colors[i] = mul_8(colors[i].g, 15);
						if (BASISD_IS_BIG_ENDIAN)
							packed_colors[i] = byteswap_uint16(packed_colors[i]);
					}

					for (uint32_t y = 0; y < max_y; y++)
					{
						const uint32_t s = pSelector->m_selectors[y];

						for (uint32_t x = 0; x < max_x; x++)
						{
							reinterpret_cast<uint16_t*>(pDst_pixels)[x] = packed_colors[(s >> (x * 2)) & 3];
						}

						pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
					}

					break;
				}
				case block_format::cETC2_EAC_R11:
				{
#if BASISD_SUPPORT_ETC2_EAC_RG11
					void* pDst_block = static_cast<uint8_t*>(pDst_blocks) + (block_x + block_y * output_row_pitch_in_blocks_or_pixels) * output_block_or_pixel_stride_in_bytes;
					convert_etc1s_to_etc2_eac_r11(static_cast<eac_block*>(pDst_block), pEndpoints, pSelector);
#else
					assert(0);
#endif
					break;
				}
				default:
				{
					assert(0);
					break;
				}
				}

			} // block_x

		} // block_y

		if (endpoint_pred_repeat_count != 0)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_slice: endpoint_pred_repeat_count != 0. The file is corrupted or this is a bug\n");
			
			if (pPVRTC_work_mem)
				free(pPVRTC_work_mem);

			return false;
		}

		//assert(endpoint_pred_repeat_count == 0);

#if BASISD_SUPPORT_PVRTC1
		// PVRTC post process - create per-pixel modulation values.
		if (fmt == block_format::cPVRTC1_4_RGB)
			fixup_pvrtc1_4_modulation_rgb((decoder_etc_block*)pPVRTC_work_mem, pPVRTC_endpoints, pDst_blocks, num_blocks_x, num_blocks_y);
		else if (fmt == block_format::cPVRTC1_4_RGBA)
			fixup_pvrtc1_4_modulation_rgba((decoder_etc_block*)pPVRTC_work_mem, pPVRTC_endpoints, pDst_blocks, num_blocks_x, num_blocks_y, pAlpha_blocks, &endpoints[0], &selectors[0]);
#endif // BASISD_SUPPORT_PVRTC1

#if BASISD_SUPPORT_BC7_MODE5
		if (bc7_chroma_filtering)
		{
			chroma_filter_bc7_mode5(decoded_endpoints, pDst_blocks, num_blocks_x, num_blocks_y, output_row_pitch_in_blocks_or_pixels, &endpoints[0]);
		}
#endif

		if (pPVRTC_work_mem)
			free(pPVRTC_work_mem);

		return true;
	}

	// Block index in PVRTC1's swizzled (twiddled) block order. width/height are in blocks and must be powers of 2.
	static uint32_t pvrtc1_4_swizzle_index(uint32_t width, uint32_t height, uint32_t x, uint32_t y)
	{
		uint32_t min_d = width, max_v = y;
		if (height < width)
		{
			min_d = height;
			max_v = x;
		}

		// Interleave the XY LSB's (Y in the low bit), then OR in the rest of the bits from the larger dimension.
		uint32_t shift_ofs = 0, swizzled = 0;
		for (uint32_t s_bit = 1, d_bit = 1; s_bit < min_d; s_bit <<= 1, d_bit <<= 2, ++shift_ofs)
		{
			if (y & s_bit) swizzled |= d_bit;
			if (x & s_bit) swizzled |= (2 * d_bit);
		}

		return swizzled | ((max_v >> shift_ofs) << (2 * shift_ofs));
	}

	// A PVRTC1 4bpp texture is at least 2x2 blocks (8x8 texels): GL sizes it as (max(width, 8) * max(height, 8) * 4 + 7) / 8, and
	// decoders (e.g. PowerVR's PVRTDecompress) decode a smaller level as that larger grid, blending every texel with its wrapped
	// neighbour blocks. The PVRTC1 transcoders only write the level's own ceil(width/4) x ceil(height/4) blocks, computed as if the
	// image wraps at that smaller grid's size. So when a level is smaller than 2x2 blocks and the output buffer can hold the larger
	// grid, this rewrites the output as the max(num_blocks_x, 2) x max(num_blocks_y, 2) grid, with each block (x, y) a copy of block
	// (x % num_blocks_x, y % num_blocks_y), in the larger grid's swizzled order. Decoding that gives exactly the image the transcoder
	// computed. Call only after a successful PVRTC1 transcode.
	static void pvrtc1_4_tile_small_level(void* pBlocks, uint32_t buf_size_in_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y)
	{
		if ((num_blocks_x >= 2) && (num_blocks_y >= 2))
			return;

		// PVRTC1 levels are power of 2 sized, so one dimension is 1 block and the other a power of 2.
		if (!basisu::is_pow2(num_blocks_x) || !basisu::is_pow2(num_blocks_y))
			return;

		const uint32_t padded_x = basisu::maximum<uint32_t>(num_blocks_x, 2);
		const uint32_t padded_y = basisu::maximum<uint32_t>(num_blocks_y, 2);

		if (buf_size_in_blocks < padded_x * padded_y)
			return;

		uint8_t* pDst = static_cast<uint8_t*>(pBlocks);
		const uint32_t bytes_per_block = 8;

		// With one dimension 1 block, the source grid's swizzled order is linear (block i is at index i). Every copy of source block i
		// lands at an index >= i in the larger grid, so working backwards reads each source block before anything overwrites it.
		for (int i = (int)(num_blocks_x * num_blocks_y) - 1; i >= 0; i--)
		{
			uint8_t blk[bytes_per_block];
			memcpy(blk, pDst + (size_t)i * bytes_per_block, bytes_per_block);

			const uint32_t src_x = (num_blocks_y == 1) ? (uint32_t)i : 0;
			const uint32_t src_y = (num_blocks_y == 1) ? 0 : (uint32_t)i;

			for (uint32_t y = src_y; y < padded_y; y += num_blocks_y)
				for (uint32_t x = src_x; x < padded_x; x += num_blocks_x)
					memcpy(pDst + (size_t)pvrtc1_4_swizzle_index(padded_x, padded_y, x, y) * bytes_per_block, blk, bytes_per_block);
		}
	}

	bool basis_validate_output_buffer_size(
		transcoder_texture_format target_format,
		uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		uint32_t orig_width, uint32_t orig_height,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		uint32_t output_rows_in_pixels)
	{
		if (basis_transcoder_format_is_uncompressed(target_format))
		{
			// Assume the output buffer is orig_width by orig_height
			if (!output_row_pitch_in_blocks_or_pixels)
				output_row_pitch_in_blocks_or_pixels = orig_width;

			if (!output_rows_in_pixels) 
				output_rows_in_pixels = orig_height;

			// Now make sure the output buffer is large enough, or we'll overwrite memory.
			if (output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels))
			{
				BASISU_DEVEL_ERROR("basis_validate_output_buffer_size: output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels)\n");
				return false;
			}
		}
		else
		{
			// Take into account the destination format's block width/height.
			const uint32_t dst_block_width = basis_get_block_width(target_format);
			const uint32_t dst_block_height = basis_get_block_height(target_format);
			//const uint32_t bytes_per_block = basis_get_bytes_per_block_or_pixel(target_format);
			
			// Compute how many blocks should be in the output.
			const uint32_t num_dst_blocks_x = (orig_width + dst_block_width - 1) / dst_block_width;
			const uint32_t num_dst_blocks_y = (orig_height + dst_block_height - 1) / dst_block_height;
			const uint32_t total_dst_blocks = num_dst_blocks_x * num_dst_blocks_y;

			assert(total_dst_blocks);

			// Note this only computes the # of blocks in the image, but for PVRTC1 OpenGL requires more for very small textures, and
			// basis_compute_transcoded_image_size_in_bytes() returns that larger size. Given a buffer that large, the PVRTC1 transcoders fill it
			// (see pvrtc1_4_tile_small_level()).
			if (output_blocks_buf_size_in_blocks_or_pixels < total_dst_blocks)
			{
				BASISU_DEVEL_ERROR("basis_validate_output_buffer_size: output_blocks_buf_size_in_blocks_or_pixels is too small\n");
				return false;
			}
		}

		return true;
	}
		
	uint32_t basis_compute_transcoded_image_size_in_bytes(transcoder_texture_format target_format, uint32_t orig_width, uint32_t orig_height)
	{
		assert(orig_width && orig_height);

		const uint32_t dst_block_width = basis_get_block_width(target_format);
		const uint32_t dst_block_height = basis_get_block_height(target_format);

		if (basis_transcoder_format_is_uncompressed(target_format))
		{
			// Uncompressed formats are just plain raster images.
			const uint32_t bytes_per_pixel = basis_get_uncompressed_bytes_per_pixel(target_format);
			const uint32_t bytes_per_line = orig_width * bytes_per_pixel;
			const uint32_t bytes_per_slice = bytes_per_line * orig_height;
			return bytes_per_slice;
		}
		
		// Compressed formats are 2D arrays of blocks.
		const uint32_t bytes_per_block = basis_get_bytes_per_block_or_pixel(target_format);

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
		{
			// For PVRTC1, Basis requires total_blocks * bytes_per_block. But GL requires extra padding for very small textures, which the transcoders
			// fill when given a buffer this large (see pvrtc1_4_tile_small_level()):
			// https://www.khronos.org/registry/OpenGL/extensions/IMG/IMG_texture_compression_pvrtc.txt
			const uint32_t width = (orig_width + 3) & ~3;
			const uint32_t height = (orig_height + 3) & ~3;
			const uint32_t size_in_bytes = (std::max(8U, width) * std::max(8U, height) * 4 + 7) / 8;
			return size_in_bytes;
		}

		// Take into account the destination format's block width/height.
		const uint32_t num_dst_blocks_x = (orig_width + dst_block_width - 1) / dst_block_width;
		const uint32_t num_dst_blocks_y = (orig_height + dst_block_height - 1) / dst_block_height;
		const uint32_t total_dst_blocks = num_dst_blocks_x * num_dst_blocks_y;

		assert(total_dst_blocks);

		return total_dst_blocks * bytes_per_block;
	}

	bool basisu_lowlevel_etc1s_transcoder::transcode_image(
			transcoder_texture_format target_format,
			void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
			const uint8_t* pCompressed_data, uint32_t compressed_data_length,
			uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
			uint64_t rgb_offset, uint32_t rgb_length, uint64_t alpha_offset, uint32_t alpha_length,
			uint32_t decode_flags,
			bool basis_file_has_alpha_slices,
			bool is_video,
			uint32_t output_row_pitch_in_blocks_or_pixels,
			basisu_transcoder_state* pState,
			uint32_t output_rows_in_pixels)
	{
		if (((uint64_t)rgb_offset + rgb_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: source data buffer too small (color)\n");
			return false;
		}

		if (alpha_length)
		{
			if (((uint64_t)alpha_offset + alpha_length) > (uint64_t)compressed_data_length)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: source data buffer too small (alpha)\n");
				return false;
			}
		}
		else
		{
			assert(!basis_file_has_alpha_slices);
		}

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
		{
			if ((!basisu::is_pow2(num_blocks_x * 4)) || (!basisu::is_pow2(num_blocks_y * 4)))
			{
				// PVRTC1 only supports power of 2 dimensions
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 only supports power of 2 dimensions\n");
				return false;
			}
		}

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA) && (!basis_file_has_alpha_slices))
		{
			// Switch to PVRTC1 RGB if the input doesn't have alpha.
			target_format = transcoder_texture_format::cTFPVRTC1_4_RGB;
		}
				
		const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;
		
		if (!basis_validate_output_buffer_size(target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		const uint8_t* pData = pCompressed_data + rgb_offset;
		uint32_t data_len = rgb_length;
		bool is_alpha_slice = false;

		// If the caller wants us to transcode the mip level's alpha data, then use the next slice.
		if ((basis_file_has_alpha_slices) && (transcode_alpha_data_to_opaque_formats))
		{
			pData = pCompressed_data + alpha_offset;
			data_len = alpha_length;
			is_alpha_slice = true;
		}

		switch (target_format)
		{
		case transcoder_texture_format::cTFETC1_RGB:
		{
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC1, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cETC1, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
							
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC1 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC1_RGB:
		{
#if !BASISD_SUPPORT_DXT1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: BC1/DXT1 unsupported\n");
			return false;
#else
			// status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC1, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cBC1, bytes_per_block_or_pixel, true, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC1 failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFBC4_R:
		{
#if !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: BC4/DXT5A unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC4 failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGB:
		{
#if !BASISD_SUPPORT_PVRTC1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 4 unsupported\n");
			return false;
#else
			// output_row_pitch_in_blocks_or_pixels is actually ignored because we're transcoding to PVRTC1. (Print a dev warning if it's != 0?)
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC1_4_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cPVRTC1_4_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to PVRTC1 4 RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		{
#if !BASISD_SUPPORT_PVRTC1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 4 unsupported\n");
			return false;
#else
			assert(basis_file_has_alpha_slices);
			assert(alpha_length);

			// Temp buffer to hold alpha block endpoint/selector indices
			basisu::vector<uint32_t> temp_block_indices(total_slice_blocks);

			// First transcode alpha data to temp buffer
			//status = transcode_slice(pData, data_size, slice_index + 1, &temp_block_indices[0], total_slice_blocks, block_format::cIndices, sizeof(uint32_t), decode_flags, pSlice_descs[slice_index].m_num_blocks_x, pState);
			status = transcode_slice(&temp_block_indices[0], num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cIndices, sizeof(uint32_t), false, is_video, true, level_index, orig_width, orig_height, num_blocks_x, pState, false, nullptr, 0, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to PVRTC1 4 RGBA failed (0)\n");
			}
			else
			{
				// output_row_pitch_in_blocks_or_pixels is actually ignored because we're transcoding to PVRTC1. (Print a dev warning if it's != 0?)
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC1_4_RGBA, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState, &temp_block_indices[0]);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cPVRTC1_4_RGBA, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, &temp_block_indices[0], 0, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to PVRTC1 4 RGBA failed (1)\n");
				}
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		{
#if !BASISD_SUPPORT_BC7_MODE5
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: BC7 unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);
			// We used to support transcoding just alpha to BC7 - but is that useful at all?

			// First transcode the color slice. The cBC7_M5_COLOR transcoder will output opaque mode 5 blocks.
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC7_M5_COLOR, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cBC7_M5_COLOR, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);

			if ((status) && (basis_file_has_alpha_slices))
			{
				// Now transcode the alpha slice. The cBC7_M5_ALPHA transcoder will now change the opaque mode 5 blocks to blocks with alpha.
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC7_M5_ALPHA, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC7_M5_ALPHA, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC7 failed (0)\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFETC2_RGBA:
		{
#if !BASISD_SUPPORT_ETC2_EAC_A8
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ETC2 EAC A8 unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data 
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_A8, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cETC2_EAC_A8, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				//write_opaque_alpha_blocks(pSlice_descs[slice_index].m_num_blocks_x, pSlice_descs[slice_index].m_num_blocks_y, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_A8, 16, output_row_pitch_in_blocks_or_pixels);
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, pOutput_blocks, block_format::cETC2_EAC_A8, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				// Now decode the color data
				//status = transcode_slice(pData, data_size, slice_index, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC1, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cETC1, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2 A failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFBC3_RGBA:
		{
#if !BASISD_SUPPORT_DXT1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT1 unsupported\n");
			return false;
#elif !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT5A unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);
						
			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
			{
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, pOutput_blocks, block_format::cBC4, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				// Now decode the color data. Forbid 3 color blocks, which aren't allowed in BC3.
				//status = transcode_slice(pData, data_size, slice_index, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC1, 16, decode_flags | cDecodeFlagsBC1ForbidThreeColorBlocks, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cBC1, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC3 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC3 A failed\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFBC5_RG:
		{
#if !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT5A unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			//bool transcode_slice(void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
				//	uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, const bool is_video, const bool is_alpha_slice, const uint32_t level_index, const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels = 0,
				//	basisu_transcoder_state* pState = nullptr, bool astc_transcode_alpha = false, void* pAlpha_blocks = nullptr, uint32_t output_rows_in_pixels = 0);

			// Decode the R data (actually the green channel of the color data slice in the basis file)
			//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (status)
			{
				if (basis_file_has_alpha_slices)
				{
					// Decode the G data (actually the green channel of the alpha data slice in the basis file)
					//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
					status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC5 1 failed\n");
					}
				}
				else
				{
					basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, (uint8_t*)pOutput_blocks + 8, block_format::cBC4, 16, output_row_pitch_in_blocks_or_pixels);
					status = true;
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to BC5 channel 0 failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
		{
#if !BASISD_SUPPORT_ASTC
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ASTC unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data to the output (we're using the output texture as a temp buffer here).
				//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cIndices, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cIndices, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (status)
				{
					// Now decode the color data and transcode to ASTC. The transcoder function will read the alpha selector data from the output texture as it converts and
					// transcode both the alpha and color data at the same time to ASTC.
					//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cASTC_LDR_4x4, 16, decode_flags | cDecodeFlagsOutputHasAlphaIndices, output_row_pitch_in_blocks_or_pixels, pState);
					status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cASTC_LDR_4x4, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, true, nullptr, output_rows_in_pixels, decode_flags);
				}
			}
			else
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cASTC_LDR_4x4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cASTC_LDR_4x4, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ASTC failed (0)\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFATC_RGB:
		{
#if !BASISD_SUPPORT_ATC
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ATC unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cATC_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cATC_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ATC_RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFATC_RGBA:
		{
#if !BASISD_SUPPORT_ATC
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: ATC unsupported\n");
			return false;
#elif !BASISD_SUPPORT_DXT5A
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: DXT5A unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
			{
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cBC4, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cBC4, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, pOutput_blocks, block_format::cBC4, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				//status = transcode_slice(pData, data_size, slice_index, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cATC_RGB, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cATC_RGB, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ATC RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ATC A failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGB:
		{
#if !BASISD_SUPPORT_PVRTC2
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC2 unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to cPVRTC2_4_RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		{
#if !BASISD_SUPPORT_PVRTC2
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC2 unsupported\n");
			return false;
#else
			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data to the output (we're using the output texture as a temp buffer here).
				//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cIndices, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cIndices, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to failed\n");
				}
				else
				{
					// Now decode the color data and transcode to PVRTC2 RGBA. 
					//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC2_4_RGBA, bytes_per_block_or_pixel, decode_flags | cDecodeFlagsOutputHasAlphaIndices, output_row_pitch_in_blocks_or_pixels, pState);
					status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cPVRTC2_4_RGBA, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, true, nullptr, output_rows_in_pixels, decode_flags);
				}
			}
			else
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cPVRTC2_4_RGB, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to cPVRTC2_4_RGBA failed\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFRGBA32:
		{
			// Raw 32bpp pixels, decoded in the usual raster order (NOT block order) into an image in memory.

			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cA32, sizeof(uint32_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cA32, sizeof(uint32_t), false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			else
				status = true;

			if (status)
			{
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, basis_file_has_alpha_slices ? block_format::cRGB32 : block_format::cRGBA32, sizeof(uint32_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, basis_file_has_alpha_slices ? block_format::cRGB32 : block_format::cRGBA32, sizeof(uint32_t), false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA32 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA32 A failed\n");
			}

			break;
		}
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		{
			// Raw 16bpp pixels, decoded in the usual raster order (NOT block order) into an image in memory.

			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, (fmt == transcoder_texture_format::cTFRGB565) ? block_format::cRGB565 : block_format::cBGR565, sizeof(uint16_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, (target_format == transcoder_texture_format::cTFRGB565) ? block_format::cRGB565 : block_format::cBGR565, sizeof(uint16_t), false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGB565 RGB failed\n");
			}

			break;
		}
		case transcoder_texture_format::cTFRGBA4444:
		{
			// Raw 16bpp pixels, decoded in the usual raster order (NOT block order) into an image in memory.

			// First decode the alpha data 
			if (basis_file_has_alpha_slices)
				//status = transcode_slice(pData, data_size, slice_index + 1, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cRGBA4444_ALPHA, sizeof(uint16_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cRGBA4444_ALPHA, sizeof(uint16_t), false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			else
				status = true;

			if (status)
			{
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, basis_file_has_alpha_slices ? block_format::cRGBA4444_COLOR : block_format::cRGBA4444_COLOR_OPAQUE, sizeof(uint16_t), decode_flags, output_row_pitch_in_blocks_or_pixels, pState, nullptr, output_rows_in_pixels);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, basis_file_has_alpha_slices ? block_format::cRGBA4444_COLOR : block_format::cRGBA4444_COLOR_OPAQUE, sizeof(uint16_t), false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA4444 RGB failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to RGBA4444 A failed\n");
			}

			break;
		}
		case transcoder_texture_format::cTFFXT1_RGB:
		{
#if !BASISD_SUPPORT_FXT1
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: FXT1 unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cFXT1_RGB, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cFXT1_RGB, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to FXT1_RGB failed\n");
			}
			break;
#endif
		}
		case transcoder_texture_format::cTFETC2_EAC_R11:
		{
#if !BASISD_SUPPORT_ETC2_EAC_RG11
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: EAC_RG11 unsupported\n");
			return false;
#else
			//status = transcode_slice(pData, data_size, slice_index_to_decode, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pData, data_len, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, false, is_video, is_alpha_slice, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2_EAC_R11 failed\n");
			}

			break;
#endif
		}
		case transcoder_texture_format::cTFETC2_EAC_RG11:
		{
#if !BASISD_SUPPORT_ETC2_EAC_RG11
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: EAC_RG11 unsupported\n");
			return false;
#else
			assert(bytes_per_block_or_pixel == 16);

			if (basis_file_has_alpha_slices)
			{
				// First decode the alpha data to G
				//status = transcode_slice(pData, data_size, slice_index + 1, (uint8_t*)pOutput_blocks + 8, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_R11, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice((uint8_t *)pOutput_blocks + 8, num_blocks_x, num_blocks_y, pCompressed_data + alpha_offset, alpha_length, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, false, is_video, true, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
			}
			else
			{
				basisu_transcoder::write_opaque_alpha_blocks(num_blocks_x, num_blocks_y, (uint8_t*)pOutput_blocks + 8, block_format::cETC2_EAC_R11, 16, output_row_pitch_in_blocks_or_pixels);
				status = true;
			}

			if (status)
			{
				// Now decode the color data to R
				//status = transcode_slice(pData, data_size, slice_index, pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, block_format::cETC2_EAC_R11, 16, decode_flags, output_row_pitch_in_blocks_or_pixels, pState);
				status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + rgb_offset, rgb_length, block_format::cETC2_EAC_R11, bytes_per_block_or_pixel, false, is_video, false, level_index, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, false, nullptr, output_rows_in_pixels, decode_flags);
				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2_EAC_R11 R failed\n");
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: transcode_slice() to ETC2_EAC_R11 G failed\n");
			}

			break;
#endif
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: Invalid fmt\n");
			break;
		}
		}

		// PVRTC1 levels smaller than 8x8 texels: fill the 2x2 block minimum (see pvrtc1_4_tile_small_level()).
		if (status && ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA)))
			pvrtc1_4_tile_small_level(pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, (orig_width + 3) >> 2, (orig_height + 3) >> 2);

		return status;
	}

	//------------------------------------------------------------------------------------------------
	// UASTC LDR 4x4 transcoder
	//------------------------------------------------------------------------------------------------
	basisu_lowlevel_uastc_ldr_4x4_transcoder::basisu_lowlevel_uastc_ldr_4x4_transcoder()
	{
	}

	bool basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
        uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha, 
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC
		const uint32_t total_blocks = num_blocks_x * num_blocks_y;

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
			{
				if (fmt == block_format::cFXT1_RGB)
					output_row_pitch_in_blocks_or_pixels = (orig_width + 7) / 8;
				else
					output_row_pitch_in_blocks_or_pixels = num_blocks_x;
			}
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		uint32_t total_expected_block_bytes = sizeof(uastc_block) * total_blocks;
		if (image_data_size < total_expected_block_bytes)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: image_data_size < total_expected_block_bytes The file is corrupted or this is a bug.\n");
			return false;
		}

		const uastc_block* pSource_block = reinterpret_cast<const uastc_block *>(pImage_data);

		const bool high_quality = (decode_flags & cDecodeFlagsHighQuality) != 0;
		const bool from_alpha = has_alpha && (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;

		bool status = false;
		if ((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA))
		{
			if (fmt == block_format::cPVRTC1_4_RGBA)
				transcode_uastc_to_pvrtc1_4_rgba((const uastc_block*)pImage_data, pDst_blocks, num_blocks_x, num_blocks_y, high_quality);
			else
				transcode_uastc_to_pvrtc1_4_rgb((const uastc_block *)pImage_data, pDst_blocks, num_blocks_x, num_blocks_y, high_quality, from_alpha);
		}
		else
		{
			for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
			{
				void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;
								
				for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t *)pDst_block + output_block_or_pixel_stride_in_bytes)
				{
					switch (fmt)
					{
					case block_format::cUASTC_4x4:
					{
						memcpy(pDst_block, pSource_block, sizeof(uastc_block));
						status = true;
						break;
					}
					case block_format::cETC1:
					{
						if (from_alpha)
							status = transcode_uastc_to_etc1(*pSource_block, pDst_block, 3);
						else
							status = transcode_uastc_to_etc1(*pSource_block, pDst_block);
						break;
					}
					case block_format::cETC2_RGBA:
					{
						status = transcode_uastc_to_etc2_rgba(*pSource_block, pDst_block);
						break;
					}
					case block_format::cBC1:
					{
						status = transcode_uastc_to_bc1(*pSource_block, pDst_block, high_quality);
						break;
					}
					case block_format::cBC3:
					{
						status = transcode_uastc_to_bc3(*pSource_block, pDst_block, high_quality);
						break;
					}
					case block_format::cBC4:
					{
						if (channel0 < 0) 
							channel0 = 0;
						status = transcode_uastc_to_bc4(*pSource_block, pDst_block, high_quality, channel0);
						break;
					}
					case block_format::cBC5:
					{
						if (channel0 < 0)
							channel0 = 0;
						if (channel1 < 0)
							channel1 = 3;
						status = transcode_uastc_to_bc5(*pSource_block, pDst_block, high_quality, channel0, channel1);
						break;
					}
					case block_format::cBC7:
					case block_format::cBC7_M5_COLOR: // for consistently with ETC1S
					{
						status = transcode_uastc_to_bc7(*pSource_block, pDst_block);
						break;
					}
					case block_format::cASTC_LDR_4x4:
					{
						status = transcode_uastc_to_astc(*pSource_block, pDst_block);
						break;
					}
					case block_format::cETC2_EAC_R11:
					{
						if (channel0 < 0)
							channel0 = 0;
						status = transcode_uastc_to_etc2_eac_r11(*pSource_block, pDst_block, high_quality, channel0);
						break;
					}
					case block_format::cETC2_EAC_RG11:
					{
						if (channel0 < 0)
							channel0 = 0;
						if (channel1 < 0)
							channel1 = 3;
						status = transcode_uastc_to_etc2_eac_rg11(*pSource_block, pDst_block, high_quality, channel0, channel1);
						break;
					}
					case block_format::cRGBA32:
					{
						color32 block_pixels[4][4];
						status = unpack_uastc(*pSource_block, (color32 *)block_pixels, false);

						assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
						uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);

						const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
						const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

						for (uint32_t y = 0; y < max_y; y++)
						{
							for (uint32_t x = 0; x < max_x; x++)
							{
								const color32& c = block_pixels[y][x];

								pDst_pixels[0 + 4 * x] = c.r;
								pDst_pixels[1 + 4 * x] = c.g;
								pDst_pixels[2 + 4 * x] = c.b;
								pDst_pixels[3 + 4 * x] = c.a;
							}

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
						}

						break;
					}
					case block_format::cRGB565:
					case block_format::cBGR565:
					{
						color32 block_pixels[4][4];
						status = unpack_uastc(*pSource_block, (color32*)block_pixels, false);

						assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
						uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

						const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
						const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

						for (uint32_t y = 0; y < max_y; y++)
						{
							for (uint32_t x = 0; x < max_x; x++)
							{
								const color32& c = block_pixels[y][x];

								const uint16_t packed = (fmt == block_format::cRGB565) ? static_cast<uint16_t>((mul_8(c.r, 31) << 11) | (mul_8(c.g, 63) << 5) | mul_8(c.b, 31)) :
									static_cast<uint16_t>((mul_8(c.b, 31) << 11) | (mul_8(c.g, 63) << 5) | mul_8(c.r, 31));

								pDst_pixels[x * 2 + 0] = (uint8_t)(packed & 0xFF);
								pDst_pixels[x * 2 + 1] = (uint8_t)((packed >> 8) & 0xFF);
							}

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
						}

						break;
					}
					case block_format::cRGBA4444:
					{
						color32 block_pixels[4][4];
						status = unpack_uastc(*pSource_block, (color32*)block_pixels, false);

						assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
						uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

						const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
						const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

						for (uint32_t y = 0; y < max_y; y++)
						{
							for (uint32_t x = 0; x < max_x; x++)
							{
								const color32& c = block_pixels[y][x];

								const uint16_t packed = static_cast<uint16_t>((mul_8(c.r, 15) << 12) | (mul_8(c.g, 15) << 8) | (mul_8(c.b, 15) << 4) | mul_8(c.a, 15));

								pDst_pixels[x * 2 + 0] = (uint8_t)(packed & 0xFF);
								pDst_pixels[x * 2 + 1] = (uint8_t)((packed >> 8) & 0xFF);
							}

							pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
						}
						break;
					}
					default:
						assert(0);
						break;

					}

					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: Transcoder failed to unpack a UASTC block - this is a bug, or the data was corrupted\n");
						return false;
					}

				} // block_x

			} // block_y
		}

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_slice: UASTC is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}
		
	bool basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}	

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
		{
			if ((!basisu::is_pow2(num_blocks_x * 4)) || (!basisu::is_pow2(num_blocks_y * 4)))
			{
				// PVRTC1 only supports power of 2 dimensions
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: PVRTC1 only supports power of 2 dimensions\n");
				return false;
			}
		}

		if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA) && (!has_alpha))
		{
			// Switch to PVRTC1 RGB if the input doesn't have alpha.
			target_format = transcoder_texture_format::cTFPVRTC1_4_RGB;
		}

		const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}
				
		bool status = false;

		// UASTC4x4
		switch (target_format)
		{
		case transcoder_texture_format::cTFETC1_RGB:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC1,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
				
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to ETC1 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFETC2_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_RGBA,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to ETC2 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC1_RGB:
		{
			// TODO: ETC1S allows BC1 from alpha channel. That doesn't seem actually useful, though.
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC1,
				bytes_per_block_or_pixel, true, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC1 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC3_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC3,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC3 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC4_R:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC4,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC4 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC5_RG:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				0, 3, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC5 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC7,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to BC7 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGB:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGB,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to PVRTC1 RGB 4bpp failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGBA,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to PVRTC1 RGBA 4bpp failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_LDR_4x4,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to ASTC 4x4 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFATC_RGB:
		case transcoder_texture_format::cTFATC_RGBA:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC LDR 4x4->ATC currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFFXT1_RGB:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC LDR 4x4->FXT1 currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGB:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC LDR 4x4->PVRTC2 currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: UASTC LDR 4x4->PVRTC2 currently unsupported\n");
			return false;
		}
		case transcoder_texture_format::cTFETC2_EAC_R11:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_R11,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to EAC R11 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFETC2_EAC_RG11:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_RG11,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
				0, 3, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_basisu_lowlevel_uastc_ldr_4x4_transcodertranscoder::transcode_image: transcode_slice() to EAC RG11 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA32:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA32,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGBA32 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB565:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB565,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBGR565:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBGR565,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA4444:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA4444,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: transcode_slice() to RGBA4444 failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_ldr_4x4_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		// PVRTC1 levels smaller than 8x8 texels: fill the 2x2 block minimum (see pvrtc1_4_tile_small_level()).
		if (status && ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA)))
			pvrtc1_4_tile_small_level(pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, (orig_width + 3) >> 2, (orig_height + 3) >> 2);

		return status;
	}
	
	//------------------------------------------------------------------------------------------------
	// UASTC HDR 4x4 transcoding
	//------------------------------------------------------------------------------------------------

	basisu_lowlevel_uastc_hdr_4x4_transcoder::basisu_lowlevel_uastc_hdr_4x4_transcoder()
	{
	}

	bool basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha, 
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(has_alpha);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(orig_width);
		BASISU_NOTE_UNUSED(orig_height);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC_HDR
		const uint32_t total_blocks = num_blocks_x * num_blocks_y;

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
				output_row_pitch_in_blocks_or_pixels = num_blocks_x;
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		uint32_t total_expected_block_bytes = sizeof(astc_blk) * total_blocks;
		if (image_data_size < total_expected_block_bytes)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: image_data_size < total_expected_block_bytes The file is corrupted or this is a bug.\n");
			return false;
		}

		const astc_blk* pSource_block = reinterpret_cast<const astc_blk*>(pImage_data);

		bool status = false;

		// TODO: Optimize pure memcpy() case.
			
		for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
		{
			void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

			for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t*)pDst_block + output_block_or_pixel_stride_in_bytes)
			{
				switch (fmt)
				{
				case block_format::cUASTC_HDR_4x4:
				case block_format::cASTC_HDR_4x4:
				{
					// Nothing to do, UASTC HDR 4x4 is just ASTC.
					memcpy(pDst_block, pSource_block, sizeof(uastc_block));
					status = true;
					break;
				}
				case block_format::cBC6H:
				{
					status = astc_hdr_transcode_to_bc6h(*pSource_block, *(bc6h_block *)pDst_block);
					break;
				}
				case block_format::cRGB_9E5:
				{
					astc_helpers::log_astc_block log_blk;
					status = astc_helpers::unpack_block(pSource_block, log_blk, 4, 4);
					if (status)
					{
						uint32_t* pDst_pixels = reinterpret_cast<uint32_t*>(
							static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t)
							);

						uint32_t blk_texels[4][4];

						status = astc_helpers::decode_block(log_blk, blk_texels, 4, 4, astc_helpers::cDecodeModeRGB9E5);
						
						if (status)
						{
							const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
							const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

							for (uint32_t y = 0; y < max_y; y++)
							{
								memcpy(pDst_pixels, &blk_texels[y][0], sizeof(uint32_t) * max_x);

								pDst_pixels += output_row_pitch_in_blocks_or_pixels;
							} // y
						}
					}
					
					break;
				}
				case block_format::cRGBA_HALF:
				{
					astc_helpers::log_astc_block log_blk;
					status = astc_helpers::unpack_block(pSource_block, log_blk, 4, 4);
					if (status)
					{
						half_float* pDst_pixels = reinterpret_cast<half_float*>(
							static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 4
							);
												
						half_float blk_texels[4][4][4];
						status = astc_helpers::decode_block(log_blk, blk_texels, 4, 4, astc_helpers::cDecodeModeHDR16);

						if (status)
						{
							const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
							const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

							for (uint32_t y = 0; y < max_y; y++)
							{
								for (uint32_t x = 0; x < max_x; x++)
								{
									pDst_pixels[0 + 4 * x] = blk_texels[y][x][0];
									pDst_pixels[1 + 4 * x] = blk_texels[y][x][1];
									pDst_pixels[2 + 4 * x] = blk_texels[y][x][2];
									pDst_pixels[3 + 4 * x] = blk_texels[y][x][3];
								} // x

								pDst_pixels += output_row_pitch_in_blocks_or_pixels * 4;
							} // y
						}
					}

					break;
				}
				case block_format::cRGB_HALF:
				{
					astc_helpers:: log_astc_block log_blk;
					status = astc_helpers::unpack_block(pSource_block, log_blk, 4, 4);
					if (status)
					{
						half_float* pDst_pixels =
							reinterpret_cast<half_float*>(static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 3);

						half_float blk_texels[4][4][4];
						status = astc_helpers::decode_block(log_blk, blk_texels, 4, 4, astc_helpers::cDecodeModeHDR16);
						if (status)
						{
							const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
							const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

							for (uint32_t y = 0; y < max_y; y++)
							{
								for (uint32_t x = 0; x < max_x; x++)
								{
									pDst_pixels[0 + 3 * x] = blk_texels[y][x][0];
									pDst_pixels[1 + 3 * x] = blk_texels[y][x][1];
									pDst_pixels[2 + 3 * x] = blk_texels[y][x][2];
								} // x

								pDst_pixels += output_row_pitch_in_blocks_or_pixels * 3;
							} // y
						}
					}

					break;
				}
				default:
					assert(0);
					break;

				}

				if (!status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: Transcoder failed to unpack a UASTC HDR block - this is a bug, or the data was corrupted\n");					
					return false;
				}

			} // block_x

		} // block_y

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_slice: UASTC_HDR is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}

	bool basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);
		BASISU_NOTE_UNUSED(decode_flags);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}

		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		switch (target_format)
		{
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_HDR_4x4,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to ASTC_HDR failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC6H:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC6H,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to BC6H failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to RGB_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_9E5:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_9E5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_4x4_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	// ASTC 6x6 HDR

	basisu_lowlevel_astc_hdr_6x6_transcoder::basisu_lowlevel_astc_hdr_6x6_transcoder()
	{
	}

	// num_blocks_x/num_blocks_y are source 6x6 blocks
	bool basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha,
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(has_alpha);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(orig_width);
		BASISU_NOTE_UNUSED(orig_height);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC_HDR
		const uint32_t total_src_blocks = num_blocks_x * num_blocks_y;

		const uint32_t output_block_width = get_block_width(fmt);
		//const uint32_t output_block_height = get_block_height(fmt);

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
				output_row_pitch_in_blocks_or_pixels = (orig_width + output_block_width - 1) / output_block_width;
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		uint32_t total_expected_block_bytes = sizeof(astc_blk) * total_src_blocks;
		if (image_data_size < total_expected_block_bytes)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: image_data_size < total_expected_block_bytes The file is corrupted or this is a bug.\n");
			return false;
		}

		const astc_blk* pSource_block = reinterpret_cast<const astc_blk*>(pImage_data);

		bool status = false;

		half_float unpacked_blocks[12][12][3]; // [y][x][c]

		assert(((orig_width + 5) / 6) == num_blocks_x);
		assert(((orig_height + 5) / 6) == num_blocks_y);
				
		if (fmt == block_format::cBC6H)
		{
			const uint32_t num_dst_blocks_x = (orig_width + 3) / 4;
			const uint32_t num_dst_blocks_y = (orig_height + 3) / 4;

			if (!output_row_pitch_in_blocks_or_pixels)
			{
				output_row_pitch_in_blocks_or_pixels = num_dst_blocks_x;
			}
			else if (output_row_pitch_in_blocks_or_pixels < num_dst_blocks_x)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: output_row_pitch_in_blocks_or_pixels is too low\n");
				return false;
			}

			if (output_block_or_pixel_stride_in_bytes != sizeof(bc6h_block))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: invalid output_block_or_pixel_stride_in_bytes\n");
				return false;
			}

			fast_bc6h_params bc6h_enc_params;
			const bool hq_flag = (decode_flags & cDecodeFlagsHighQuality) != 0;
			bc6h_enc_params.m_max_2subset_pats_to_try = hq_flag ? 1 : 0;
						
			for (uint32_t src_block_y = 0; src_block_y < num_blocks_y; src_block_y += 2)
			{
				const uint32_t num_inner_blocks_y = basisu::minimum<uint32_t>(2, num_blocks_y - src_block_y);

				for (uint32_t src_block_x = 0; src_block_x < num_blocks_x; src_block_x += 2)
				{
					const uint32_t num_inner_blocks_x = basisu::minimum<uint32_t>(2, num_blocks_x - src_block_x);

					for (uint32_t iy = 0; iy < num_inner_blocks_y; iy++)
					{
						for (uint32_t ix = 0; ix < num_inner_blocks_x; ix++)
						{
							const astc_blk* pS = pSource_block + (src_block_y + iy) * num_blocks_x + (src_block_x + ix);

							half_float blk_texels[6][6][4];
							
							astc_helpers::log_astc_block log_blk;
							status = astc_helpers::unpack_block(pS, log_blk, 6, 6);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}
							
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}

							for (uint32_t y = 0; y < 6; y++)
							{
								for (uint32_t x = 0; x < 6; x++)
								{
									unpacked_blocks[iy * 6 + y][ix * 6 + x][0] = blk_texels[y][x][0];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][1] = blk_texels[y][x][1];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][2] = blk_texels[y][x][2];
																		
								} // x
							} // y

						} // ix

					} // iy
	
					const uint32_t dst_x = src_block_x * 6;
					assert((dst_x & 3) == 0);
					const uint32_t dst_block_x = dst_x >> 2;

					const uint32_t dst_y = src_block_y * 6;
					assert((dst_y & 3) == 0);
					const uint32_t dst_block_y = dst_y >> 2;

					const uint32_t num_inner_dst_blocks_x = basisu::minimum<uint32_t>(3, num_dst_blocks_x - dst_block_x);
					const uint32_t num_inner_dst_blocks_y = basisu::minimum<uint32_t>(3, num_dst_blocks_y - dst_block_y);

					for (uint32_t dy = 0; dy < num_inner_dst_blocks_y; dy++)
					{
						for (uint32_t dx = 0; dx < num_inner_dst_blocks_x; dx++)
						{
							bc6h_block* pDst_block = (bc6h_block*)pDst_blocks + (dst_block_x + dx) + (dst_block_y + dy) * output_row_pitch_in_blocks_or_pixels;

							half_float src_pixels[4][4][3]; // [y][x][c]

							for (uint32_t y = 0; y < 4; y++)
							{
								const uint32_t src_pixel_y = basisu::minimum<uint32_t>(dy * 4 + y, num_inner_blocks_y * 6 - 1);

								for (uint32_t x = 0; x < 4; x++)
								{
									const uint32_t src_pixel_x = basisu::minimum<uint32_t>(dx * 4 + x, num_inner_blocks_x * 6 - 1);

									assert((src_pixel_y < 12) && (src_pixel_x < 12));

									src_pixels[y][x][0] = unpacked_blocks[src_pixel_y][src_pixel_x][0];
									src_pixels[y][x][1] = unpacked_blocks[src_pixel_y][src_pixel_x][1];
									src_pixels[y][x][2] = unpacked_blocks[src_pixel_y][src_pixel_x][2];
									
								} // x
							} // y
							
							astc_6x6_hdr::fast_encode_bc6h(&src_pixels[0][0][0], pDst_block, bc6h_enc_params);

						} // dx
					} // dy

				} // block_x

			} // block_y
						
			status = true;
		}
		else
		{
			for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
			{
				void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

				for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t*)pDst_block + output_block_or_pixel_stride_in_bytes)
				{
					switch (fmt)
					{
					case block_format::cASTC_HDR_6x6:
					{
						// Nothing to do, ASTC HDR 6x6 is just ASTC.
						// TODO: Optimize this copy
						memcpy(pDst_block, pSource_block, sizeof(astc_helpers::astc_block));
						status = true;
						break;
					}
					case block_format::cRGB_9E5:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							uint32_t* pDst_pixels = reinterpret_cast<uint32_t*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t)
								);

							uint32_t blk_texels[6][6];

							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeRGB9E5);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									memcpy(pDst_pixels, &blk_texels[y][0], sizeof(uint32_t) * max_x);

									pDst_pixels += output_row_pitch_in_blocks_or_pixels;
								} // y
							}
						}

						break;
					}
					case block_format::cRGBA_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels = reinterpret_cast<half_float*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 4
								);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 4 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 4 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 4 * x] = blk_texels[y][x][2];
										pDst_pixels[3 + 4 * x] = blk_texels[y][x][3];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 4;
								} // y
							}
						}

						break;
					}
					case block_format::cRGB_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels =
								reinterpret_cast<half_float*>(static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 3);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 3 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 3 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 3 * x] = blk_texels[y][x][2];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 3;
								} // y
							}
						}

						break;
					}
					default:
						assert(0);
						break;

					}

					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");					
						return false;
					}

				} // block_x

			} // block_y
		}

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_slice: ASTC HDR is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}

	bool basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);
		BASISU_NOTE_UNUSED(decode_flags);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}

		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		switch (target_format)
		{
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_HDR_6x6,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to ASTC_HDR failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC6H:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC6H,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to BC6H failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to RGB_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_9E5:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_9E5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_astc_hdr_6x6_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	// UASTC 6x6 HDR intermediate

	basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder()
	{
	}

	// num_blocks_x/num_blocks_y are source 6x6 blocks
	bool basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice(
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha,
		const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
	{
		BASISU_NOTE_UNUSED(pState);
		BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
		BASISU_NOTE_UNUSED(has_alpha);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(orig_width);
		BASISU_NOTE_UNUSED(orig_height);

		assert(g_transcoder_initialized);
		if (!g_transcoder_initialized)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder not globally initialized.\n");
			return false;
		}

#if BASISD_SUPPORT_UASTC_HDR

		// TODO: Optimize this

		basisu::vector2D<astc_helpers::astc_block> decoded_blocks;
		uint32_t dec_width = 0, dec_height = 0;
		bool dec_status = astc_6x6_hdr::decode_6x6_hdr(pImage_data, image_data_size, decoded_blocks, dec_width, dec_height);
		if (!dec_status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: decode_6x6_hdr() failed.\n");
			return false;
		}

		if ((dec_width != orig_width) || (dec_height != orig_height) ||
			(decoded_blocks.get_width() != num_blocks_x) || (decoded_blocks.get_height() != num_blocks_y))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: unexpected decoded width/height\n");
			return false;
		}

		//const uint32_t total_src_blocks = num_blocks_x * num_blocks_y;

		const uint32_t output_block_width = get_block_width(fmt);
		//const uint32_t output_block_height = get_block_height(fmt);

		if (!output_row_pitch_in_blocks_or_pixels)
		{
			if (basis_block_format_is_uncompressed(fmt))
				output_row_pitch_in_blocks_or_pixels = orig_width;
			else
				output_row_pitch_in_blocks_or_pixels = (orig_width + output_block_width - 1) / output_block_width;
		}

		if (basis_block_format_is_uncompressed(fmt))
		{
			if (!output_rows_in_pixels)
				output_rows_in_pixels = orig_height;
		}

		const astc_blk* pSource_block = (const astc_blk *)decoded_blocks.get_ptr();

		bool status = false;

		half_float unpacked_blocks[12][12][3]; // [y][x][c]

		assert(((orig_width + 5) / 6) == num_blocks_x);
		assert(((orig_height + 5) / 6) == num_blocks_y);

		if (fmt == block_format::cBC6H)
		{
			const uint32_t num_dst_blocks_x = (orig_width + 3) / 4;
			const uint32_t num_dst_blocks_y = (orig_height + 3) / 4;

			if (!output_row_pitch_in_blocks_or_pixels)
			{
				output_row_pitch_in_blocks_or_pixels = num_dst_blocks_x;
			}
			else if (output_row_pitch_in_blocks_or_pixels < num_dst_blocks_x)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: output_row_pitch_in_blocks_or_pixels is too low\n");
				return false;
			}

			if (output_block_or_pixel_stride_in_bytes != sizeof(bc6h_block))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: invalid output_block_or_pixel_stride_in_bytes\n");
				return false;
			}

			fast_bc6h_params bc6h_enc_params;
			const bool hq_flag = (decode_flags & cDecodeFlagsHighQuality) != 0;
			bc6h_enc_params.m_max_2subset_pats_to_try = hq_flag ? 1 : 0;
									
			for (uint32_t src_block_y = 0; src_block_y < num_blocks_y; src_block_y += 2)
			{
				const uint32_t num_inner_blocks_y = basisu::minimum<uint32_t>(2, num_blocks_y - src_block_y);

				for (uint32_t src_block_x = 0; src_block_x < num_blocks_x; src_block_x += 2)
				{
					const uint32_t num_inner_blocks_x = basisu::minimum<uint32_t>(2, num_blocks_x - src_block_x);

					for (uint32_t iy = 0; iy < num_inner_blocks_y; iy++)
					{
						for (uint32_t ix = 0; ix < num_inner_blocks_x; ix++)
						{
							const astc_blk* pS = pSource_block + (src_block_y + iy) * num_blocks_x + (src_block_x + ix);

							half_float blk_texels[6][6][4];

							astc_helpers::log_astc_block log_blk;
							status = astc_helpers::unpack_block(pS, log_blk, 6, 6);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}

							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (!status)
							{
								BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
								return false;
							}

							for (uint32_t y = 0; y < 6; y++)
							{
								for (uint32_t x = 0; x < 6; x++)
								{
									unpacked_blocks[iy * 6 + y][ix * 6 + x][0] = blk_texels[y][x][0];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][1] = blk_texels[y][x][1];
									unpacked_blocks[iy * 6 + y][ix * 6 + x][2] = blk_texels[y][x][2];
								} // x
							} // y

						} // ix

					} // iy

					const uint32_t dst_x = src_block_x * 6;
					assert((dst_x & 3) == 0);
					const uint32_t dst_block_x = dst_x >> 2;

					const uint32_t dst_y = src_block_y * 6;
					assert((dst_y & 3) == 0);
					const uint32_t dst_block_y = dst_y >> 2;

					const uint32_t num_inner_dst_blocks_x = basisu::minimum<uint32_t>(3, num_dst_blocks_x - dst_block_x);
					const uint32_t num_inner_dst_blocks_y = basisu::minimum<uint32_t>(3, num_dst_blocks_y - dst_block_y);

					for (uint32_t dy = 0; dy < num_inner_dst_blocks_y; dy++)
					{
						for (uint32_t dx = 0; dx < num_inner_dst_blocks_x; dx++)
						{
							bc6h_block* pDst_block = (bc6h_block*)pDst_blocks + (dst_block_x + dx) + (dst_block_y + dy) * output_row_pitch_in_blocks_or_pixels;

							half_float src_pixels[4][4][3]; // [y][x][c]

							for (uint32_t y = 0; y < 4; y++)
							{
								const uint32_t src_pixel_y = basisu::minimum<uint32_t>(dy * 4 + y, num_inner_blocks_y * 6 - 1);

								for (uint32_t x = 0; x < 4; x++)
								{
									const uint32_t src_pixel_x = basisu::minimum<uint32_t>(dx * 4 + x, num_inner_blocks_x * 6 - 1);

									assert((src_pixel_y < 12) && (src_pixel_x < 12));

									src_pixels[y][x][0] = unpacked_blocks[src_pixel_y][src_pixel_x][0];
									src_pixels[y][x][1] = unpacked_blocks[src_pixel_y][src_pixel_x][1];
									src_pixels[y][x][2] = unpacked_blocks[src_pixel_y][src_pixel_x][2];

								} // x
							} // y
														
							astc_6x6_hdr::fast_encode_bc6h(&src_pixels[0][0][0], pDst_block, bc6h_enc_params);

						} // dx
					} // dy

				} // block_x

			} // block_y

			status = true;
		}
		else
		{
			for (uint32_t block_y = 0; block_y < num_blocks_y; ++block_y)
			{
				void* pDst_block = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

				for (uint32_t block_x = 0; block_x < num_blocks_x; ++block_x, ++pSource_block, pDst_block = (uint8_t*)pDst_block + output_block_or_pixel_stride_in_bytes)
				{
					switch (fmt)
					{
					case block_format::cASTC_HDR_6x6:
					{
						// Nothing to do, ASTC HDR 6x6 is just ASTC.
						// TODO: Optimize this copy
						memcpy(pDst_block, pSource_block, sizeof(astc_helpers::astc_block));
						status = true;
						break;
					}
					case block_format::cRGB_9E5:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							uint32_t* pDst_pixels = reinterpret_cast<uint32_t*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t)
								);

							uint32_t blk_texels[6][6];

							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeRGB9E5);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									memcpy(pDst_pixels, &blk_texels[y][0], sizeof(uint32_t) * max_x);

									pDst_pixels += output_row_pitch_in_blocks_or_pixels;
								} // y
							}
						}

						break;
					}
					case block_format::cRGBA_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels = reinterpret_cast<half_float*>(
								static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 4
								);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);

							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 4 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 4 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 4 * x] = blk_texels[y][x][2];
										pDst_pixels[3 + 4 * x] = blk_texels[y][x][3];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 4;
								} // y
							}
						}

						break;
					}
					case block_format::cRGB_HALF:
					{
						astc_helpers::log_astc_block log_blk;
						status = astc_helpers::unpack_block(pSource_block, log_blk, 6, 6);
						if (status)
						{
							half_float* pDst_pixels =
								reinterpret_cast<half_float*>(static_cast<uint8_t*>(pDst_blocks) + (block_x * 6 + block_y * 6 * output_row_pitch_in_blocks_or_pixels) * sizeof(half_float) * 3);

							half_float blk_texels[6][6][4];
							status = astc_helpers::decode_block(log_blk, blk_texels, 6, 6, astc_helpers::cDecodeModeHDR16);
							if (status)
							{
								const uint32_t max_x = basisu::minimum<int>(6, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 6);
								const uint32_t max_y = basisu::minimum<int>(6, (int)output_rows_in_pixels - (int)block_y * 6);

								for (uint32_t y = 0; y < max_y; y++)
								{
									for (uint32_t x = 0; x < max_x; x++)
									{
										pDst_pixels[0 + 3 * x] = blk_texels[y][x][0];
										pDst_pixels[1 + 3 * x] = blk_texels[y][x][1];
										pDst_pixels[2 + 3 * x] = blk_texels[y][x][2];
									} // x

									pDst_pixels += output_row_pitch_in_blocks_or_pixels * 3;
								} // y
							}
						}

						break;
					}
					default:
						assert(0);
						break;

					}

					if (!status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: Transcoder failed to unpack a ASTC HDR block - this is a bug, or the data was corrupted\n");
						return false;
					}

				} // block_x

			} // block_y
		}

		return true;
#else
		BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_slice: ASTC HDR is unsupported\n");

		BASISU_NOTE_UNUSED(decode_flags);
		BASISU_NOTE_UNUSED(channel0);
		BASISU_NOTE_UNUSED(channel1);
		BASISU_NOTE_UNUSED(output_rows_in_pixels);
		BASISU_NOTE_UNUSED(output_row_pitch_in_blocks_or_pixels);
		BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);
		BASISU_NOTE_UNUSED(fmt);
		BASISU_NOTE_UNUSED(image_data_size);
		BASISU_NOTE_UNUSED(pImage_data);
		BASISU_NOTE_UNUSED(num_blocks_x);
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pDst_blocks);

		return false;
#endif
	}

	bool basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image(
		transcoder_texture_format target_format,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		const uint8_t* pCompressed_data, uint32_t compressed_data_length,
		uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
		uint64_t slice_offset, uint32_t slice_length,
		uint32_t decode_flags,
		bool has_alpha,
		bool is_video,
		uint32_t output_row_pitch_in_blocks_or_pixels,
		basisu_transcoder_state* pState,
		uint32_t output_rows_in_pixels,
		int channel0, int channel1)
	{
		BASISU_NOTE_UNUSED(is_video);
		BASISU_NOTE_UNUSED(level_index);
		BASISU_NOTE_UNUSED(decode_flags);

		if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: source data buffer too small\n");
			return false;
		}

		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);
		//const uint32_t total_slice_blocks = num_blocks_x * num_blocks_y;

		if (!basis_validate_output_buffer_size(target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: output buffer size too small\n");
			return false;
		}

		bool status = false;

		switch (target_format)
		{
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cASTC_HDR_6x6,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to ASTC_HDR failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFBC6H:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC6H,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to BC6H failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to RGB_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGBA_HALF:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA_HALF,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		case transcoder_texture_format::cTFRGB_9E5:
		{
			status = transcode_slice(pOutput_blocks, num_blocks_x, num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB_9E5,
				bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1 , decode_flags);
			if (!status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: transcode_slice() to RGBA_HALF failed\n");
			}
			break;
		}
		default:
		{
			assert(0);
			BASISU_DEVEL_ERROR("basisu_lowlevel_uastc_hdr_6x6_intermediate_transcoder::transcode_image: Invalid format\n");
			break;
		}
		}

		return status;
	}

	//------------------------------------------------------------------------------------------------
	
	basisu_transcoder::basisu_transcoder() :
		m_ready_to_transcode(false)
	{
	}

	bool basisu_transcoder::validate_file_checksums(const void* pData, uint32_t data_size, bool full_validation) const
	{
		if (!validate_header(pData, data_size))
			return false;

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

#if !BASISU_NO_HEADER_OR_DATA_CRC16_CHECKS
		if (crc16(&pHeader->m_data_size, sizeof(basis_file_header) - BASISU_OFFSETOF(basis_file_header, m_data_size), 0) != pHeader->m_header_crc16)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header CRC check failed\n");
			return false;
		}

		if (full_validation)
		{
			if (crc16(reinterpret_cast<const uint8_t*>(pData) + sizeof(basis_file_header), pHeader->m_data_size, 0) != pHeader->m_data_crc16)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: data CRC check failed\n");
				return false;
			}
		}
#endif		

		return true;
	}

	bool basisu_transcoder::validate_header_quick(const void* pData, uint32_t data_size) const
	{
		if (data_size <= sizeof(basis_file_header))
			return false;

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		if ((pHeader->m_sig != basis_file_header::cBASISSigValue) || (pHeader->m_ver != BASISD_SUPPORTED_BASIS_VERSION) || (pHeader->m_header_size != sizeof(basis_file_header)))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header has an invalid signature, or file version is unsupported\n");
			return false;
		}

		uint32_t expected_file_size = sizeof(basis_file_header) + pHeader->m_data_size;
		if (data_size < expected_file_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: source buffer is too small\n");
			return false;
		}

		if ((!pHeader->m_total_slices) || (!pHeader->m_total_images))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: header is invalid\n");
			return false;
		}

		if ((pHeader->m_slice_desc_file_ofs >= data_size) ||
			((data_size - pHeader->m_slice_desc_file_ofs) < (sizeof(basis_slice_desc) * pHeader->m_total_slices))
			)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: passed in buffer is too small or data is corrupted\n");
			return false;
		}

		return true;
	}

	bool basisu_transcoder::validate_header(const void* pData, uint32_t data_size) const
	{
		if (data_size <= sizeof(basis_file_header))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: input source buffer is too small\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		if ((pHeader->m_sig != basis_file_header::cBASISSigValue) || (pHeader->m_ver != BASISD_SUPPORTED_BASIS_VERSION) || (pHeader->m_header_size != sizeof(basis_file_header)))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header has an invalid signature, or file version is unsupported\n");
			return false;
		}

		uint32_t expected_file_size = sizeof(basis_file_header) + pHeader->m_data_size;
		if (data_size < expected_file_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: input source buffer is too small, or header is corrupted\n");
			return false;
		}

		if ((!pHeader->m_total_images) || (!pHeader->m_total_slices))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: invalid basis file (total images or slices are 0)\n");
			return false;
		}

		if (pHeader->m_total_images > pHeader->m_total_slices)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: invalid basis file (too many images)\n");
			return false;
		}

		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices)
			{
				if (pHeader->m_total_slices & 1)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: invalid alpha .basis file\n");
					return false;
				}
			}
		
			// This flag dates back to pre-Basis Universal, when .basis supported full ETC1 too.
			if ((pHeader->m_flags & cBASISHeaderFlagETC1S) == 0)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: Invalid .basis file (ETC1S check)\n");
				return false;
			}
		}
		else
		{
			if ((pHeader->m_flags & cBASISHeaderFlagETC1S) != 0)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: Invalid .basis file (ETC1S check)\n");
				return false;
			}
		}
		
		if ((pHeader->m_slice_desc_file_ofs >= data_size) ||
			((data_size - pHeader->m_slice_desc_file_ofs) < (sizeof(basis_slice_desc) * pHeader->m_total_slices))
			)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: passed in buffer is too small or data is corrupted\n");
			return false;
		}

		return true;
	}

	basis_texture_type basisu_transcoder::get_texture_type(const void* pData, uint32_t data_size) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_texture_type: header validation failed\n");
			return cBASISTexType2DArray;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		basis_texture_type btt = static_cast<basis_texture_type>(static_cast<uint8_t>(pHeader->m_tex_type));

		if (btt >= cBASISTexTypeTotal)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::validate_header_quick: header's texture type field is invalid\n");
			return cBASISTexType2DArray;
		}

		return btt;
	}

	bool basisu_transcoder::get_userdata(const void* pData, uint32_t data_size, uint32_t& userdata0, uint32_t& userdata1) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_userdata: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		userdata0 = pHeader->m_userdata0;
		userdata1 = pHeader->m_userdata1;
		return true;
	}

	uint32_t basisu_transcoder::get_total_images(const void* pData, uint32_t data_size) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_images: header validation failed\n");
			return 0;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		return pHeader->m_total_images;
	}

	basis_tex_format basisu_transcoder::get_basis_tex_format(const void* pData, uint32_t data_size) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_basis_tex_format: header validation failed\n");
			return basis_tex_format::cETC1S;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		return (basis_tex_format)(uint32_t)pHeader->m_tex_format;
	}

	static bool check_slice_desc(const basis_slice_desc& slice_desc, uint32_t block_width, uint32_t block_height)
	{
		// calculated by us from the source format
		assert((block_width >= 4) && (block_width <= 12));
		assert((block_height >= 4) && (block_height <= 12));

		// ensure the unpadded image dimensions are valid
		if ((!slice_desc.m_orig_width) || (!slice_desc.m_orig_height))
			return false;
				
		if ((slice_desc.m_orig_width > BASISU_MAX_SUPPORTED_TEXTURE_DIMENSION) || (slice_desc.m_orig_height > BASISU_MAX_SUPPORTED_TEXTURE_DIMENSION))
			return false;

		// now calculate the number of expected blocks on each dimension given the source format's block size
		const uint32_t num_blocks_x_expected = (slice_desc.m_orig_width + block_width - 1) / block_width;
		const uint32_t num_blocks_y_expected = (slice_desc.m_orig_height + block_height - 1) / block_height;

		// ensure the slice has the exact number of expected blocks on each dimension
		if ((slice_desc.m_num_blocks_x != num_blocks_x_expected) || (slice_desc.m_num_blocks_y != num_blocks_y_expected))
			return false;

		// at this point the original texture dimensions are valid, and the stored block dimensions
		// exactly match the padded dimensions implied by those original dimensions

		return true;
	}

	static bool check_slice_desc(const basis_file_header* pHeader, const basis_slice_desc& slice_desc)
	{
		if (pHeader->m_tex_format >= (uint32_t)basis_tex_format::cTotalFormats)
			return false;

		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));

		return check_slice_desc(slice_desc, block_width, block_height);
	}

	bool basisu_transcoder::get_image_info(const void* pData, uint32_t data_size, basisu_image_info& image_info, uint32_t image_index) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: header validation failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, 0);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid slice index\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid image_index\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		uint32_t total_levels = 1;
		for (uint32_t i = slice_index + 1; i < pHeader->m_total_slices; i++)
			if (pSlice_descs[i].m_image_index == image_index)
				total_levels = basisu::maximum<uint32_t>(total_levels, pSlice_descs[i].m_level_index + 1);
			else
				break;

		if (total_levels > 16)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid image_index\n");
			return false;
		}

		const basis_slice_desc& slice_desc = pSlice_descs[slice_index];
				
		image_info.m_image_index = image_index;
		image_info.m_total_levels = total_levels;
		
		image_info.m_alpha_flag = false;

		if (pHeader->m_tex_format >= (uint32_t)basis_tex_format::cTotalFormats)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid m_tex_format\n");
			return false;
		}

		// For ETC1S, if anything has alpha all images have alpha. For UASTC, we only report alpha when the image actually has alpha.
		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
			image_info.m_alpha_flag = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0; 
		else
			image_info.m_alpha_flag = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;

		image_info.m_iframe_flag = (slice_desc.m_flags & cSliceDescFlagsFrameIsIFrame) != 0;
				
		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));

		if (!check_slice_desc(slice_desc, block_width, block_height))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid slice_desc\n");
			return false;
		}
				
		image_info.m_width = slice_desc.m_num_blocks_x * block_width;
		image_info.m_height = slice_desc.m_num_blocks_y * block_height;
		image_info.m_orig_width = slice_desc.m_orig_width;
		image_info.m_orig_height = slice_desc.m_orig_height;
		image_info.m_num_blocks_x = slice_desc.m_num_blocks_x;
		image_info.m_num_blocks_y = slice_desc.m_num_blocks_y;
		image_info.m_block_width = block_width;
		image_info.m_block_height = block_height;
		image_info.m_total_blocks = image_info.m_num_blocks_x * image_info.m_num_blocks_y;
		image_info.m_first_slice_index = slice_index;

		return true;
	}

	uint32_t basisu_transcoder::get_total_image_levels(const void* pData, uint32_t data_size, uint32_t image_index) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: header validation failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, 0);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: failed finding slice\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: invalid image_index\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		uint32_t total_levels = 1;
		for (uint32_t i = slice_index + 1; i < pHeader->m_total_slices; i++)
			if (pSlice_descs[i].m_image_index == image_index)
				total_levels = basisu::maximum<uint32_t>(total_levels, pSlice_descs[i].m_level_index + 1);
			else
				break;

		const uint32_t cMaxSupportedLevels = 16;
		if (total_levels > cMaxSupportedLevels)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_total_image_levels: invalid image levels!\n");
			return false;
		}

		return total_levels;
	}

	bool basisu_transcoder::get_image_level_desc(const void* pData, uint32_t data_size, uint32_t image_index, uint32_t level_index, uint32_t& orig_width, uint32_t& orig_height, uint32_t& total_blocks) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_desc: header validation failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, level_index);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_desc: failed finding slice\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_desc: invalid image_index\n");
			return false;
		}

		if (pHeader->m_tex_format >= (uint32_t)basis_tex_format::cTotalFormats)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid m_tex_format\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		const basis_slice_desc& slice_desc = pSlice_descs[slice_index];

		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));

		if (!check_slice_desc(slice_desc, block_width, block_height))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_desc: invalid slice_desc\n");
			return false;
		}

		orig_width = slice_desc.m_orig_width;
		orig_height = slice_desc.m_orig_height;
		total_blocks = slice_desc.m_num_blocks_x * slice_desc.m_num_blocks_y;

		return true;
	}

	bool basisu_transcoder::get_image_level_info(const void* pData, uint32_t data_size, basisu_image_level_info& image_info, uint32_t image_index, uint32_t level_index) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_info: validate_file_checksums failed\n");
			return false;
		}

		int slice_index = find_first_slice_index(pData, data_size, image_index, level_index);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_info: failed finding slice\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);

		if (image_index >= pHeader->m_total_images)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_info: invalid image_index\n");
			return false;
		}

		if (pHeader->m_tex_format >= (uint32_t)basis_tex_format::cTotalFormats)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_info: invalid m_tex_format\n");
			return false;
		}

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		const basis_slice_desc& slice_desc = pSlice_descs[slice_index];

		image_info.m_image_index = image_index;
		image_info.m_level_index = level_index;
		
		// For ETC1S, if anything has alpha all images have alpha. For UASTC, we only report alpha when the image actually has alpha.
		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
			image_info.m_alpha_flag = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0;
		else
			image_info.m_alpha_flag = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;
		
		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));

		if (!check_slice_desc(slice_desc, block_width, block_height))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_image_level_info: invalid slice_desc\n");
			return false;
		}

		image_info.m_iframe_flag = (slice_desc.m_flags & cSliceDescFlagsFrameIsIFrame) != 0;
		image_info.m_width = slice_desc.m_num_blocks_x * block_width;
		image_info.m_height = slice_desc.m_num_blocks_y * block_height;
		image_info.m_orig_width = slice_desc.m_orig_width;
		image_info.m_orig_height = slice_desc.m_orig_height;
		image_info.m_block_width = block_width;
		image_info.m_block_height = block_height;
		image_info.m_num_blocks_x = slice_desc.m_num_blocks_x;
		image_info.m_num_blocks_y = slice_desc.m_num_blocks_y;
		image_info.m_total_blocks = image_info.m_num_blocks_x * image_info.m_num_blocks_y;
		image_info.m_first_slice_index = slice_index;

		image_info.m_rgb_file_ofs = slice_desc.m_file_ofs;
		image_info.m_rgb_file_len = slice_desc.m_file_size;
		image_info.m_alpha_file_ofs = 0;
		image_info.m_alpha_file_len = 0;

		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices)
			{
				assert((slice_index + 1) < (int)pHeader->m_total_slices);
				image_info.m_alpha_file_ofs = pSlice_descs[slice_index + 1].m_file_ofs;
				image_info.m_alpha_file_len = pSlice_descs[slice_index + 1].m_file_size;
			}
		}

		return true;
	}

	bool basisu_transcoder::get_file_info(const void* pData, uint32_t data_size, basisu_file_info& file_info) const
	{
		if (!validate_file_checksums(pData, data_size, false))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: validate_file_checksums failed\n");
			return false;
		}

		const basis_file_header* pHeader = static_cast<const basis_file_header*>(pData);
		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(static_cast<const uint8_t*>(pData) + pHeader->m_slice_desc_file_ofs);

		file_info.m_version = pHeader->m_ver;

		file_info.m_total_header_size = sizeof(basis_file_header) + pHeader->m_total_slices * sizeof(basis_slice_desc);

		file_info.m_total_selectors = pHeader->m_total_selectors;
		file_info.m_selector_codebook_ofs = pHeader->m_selector_cb_file_ofs;
		file_info.m_selector_codebook_size = pHeader->m_selector_cb_file_size;

		file_info.m_total_endpoints = pHeader->m_total_endpoints;
		file_info.m_endpoint_codebook_ofs = pHeader->m_endpoint_cb_file_ofs;
		file_info.m_endpoint_codebook_size = pHeader->m_endpoint_cb_file_size;

		file_info.m_tables_ofs = pHeader->m_tables_file_ofs;
		file_info.m_tables_size = pHeader->m_tables_file_size;

		file_info.m_tex_format = static_cast<basis_tex_format>(static_cast<int>(pHeader->m_tex_format));
		if (file_info.m_tex_format >= basis_tex_format::cTotalFormats)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: invalid m_tex_format\n");
			return false;
		}

		file_info.m_etc1s = (pHeader->m_tex_format == (int)basis_tex_format::cETC1S);
		
		file_info.m_y_flipped = (pHeader->m_flags & cBASISHeaderFlagYFlipped) != 0;
		file_info.m_srgb = (pHeader->m_flags & cBASISHeaderFlagSRGB) != 0;
		file_info.m_has_alpha_slices = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0;

		const uint32_t total_slices = pHeader->m_total_slices;

		file_info.m_slice_info.resize(total_slices);

		file_info.m_slices_size = 0;

		file_info.m_tex_type = static_cast<basis_texture_type>(static_cast<uint8_t>(pHeader->m_tex_type));

		if (file_info.m_tex_type >= cBASISTexTypeTotal)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: invalid texture type, file is corrupted\n");
			return false;
		}

		file_info.m_us_per_frame = pHeader->m_us_per_frame;
		file_info.m_userdata0 = pHeader->m_userdata0;
		file_info.m_userdata1 = pHeader->m_userdata1;

		file_info.m_image_mipmap_levels.resize(0);
		file_info.m_image_mipmap_levels.resize(pHeader->m_total_images);

		file_info.m_total_images = pHeader->m_total_images;

		const uint32_t block_width = basis_tex_format_get_block_width((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		const uint32_t block_height = basis_tex_format_get_block_height((basis_tex_format)((uint32_t)pHeader->m_tex_format));
		file_info.m_block_width = block_width;
		file_info.m_block_height = block_height;

		for (uint32_t i = 0; i < total_slices; i++)
		{
			file_info.m_slices_size += pSlice_descs[i].m_file_size;

			basisu_slice_info& slice_info = file_info.m_slice_info[i];

			if (!check_slice_desc(pSlice_descs[i], block_width, block_height))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: invalid slice desc\n");
				return false;
			}

			slice_info.m_orig_width = pSlice_descs[i].m_orig_width;
			slice_info.m_orig_height = pSlice_descs[i].m_orig_height;
			slice_info.m_width = pSlice_descs[i].m_num_blocks_x * block_width;
			slice_info.m_height = pSlice_descs[i].m_num_blocks_y * block_height;
			slice_info.m_num_blocks_x = pSlice_descs[i].m_num_blocks_x;
			slice_info.m_num_blocks_y = pSlice_descs[i].m_num_blocks_y;
			slice_info.m_block_width = block_width;
			slice_info.m_block_height = block_height;
			slice_info.m_total_blocks = slice_info.m_num_blocks_x * slice_info.m_num_blocks_y;
			slice_info.m_compressed_size = pSlice_descs[i].m_file_size;
			slice_info.m_slice_index = i;
			slice_info.m_image_index = pSlice_descs[i].m_image_index;
			slice_info.m_level_index = pSlice_descs[i].m_level_index;
			slice_info.m_unpacked_slice_crc16 = pSlice_descs[i].m_slice_data_crc16;
			slice_info.m_alpha_flag = (pSlice_descs[i].m_flags & cSliceDescFlagsHasAlpha) != 0;
			slice_info.m_iframe_flag = (pSlice_descs[i].m_flags & cSliceDescFlagsFrameIsIFrame) != 0;

			if (pSlice_descs[i].m_image_index >= pHeader->m_total_images)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: slice desc's image index is invalid\n");
				return false;
			}

			file_info.m_image_mipmap_levels[pSlice_descs[i].m_image_index] = basisu::maximum<uint32_t>(file_info.m_image_mipmap_levels[pSlice_descs[i].m_image_index], pSlice_descs[i].m_level_index + 1);

			if (file_info.m_image_mipmap_levels[pSlice_descs[i].m_image_index] > 16)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_file_info: slice mipmap level is invalid\n");
				return false;
			}
		}

		return true;
	}

	bool basisu_transcoder::get_key_values(const void* pData, uint32_t data_size, key_value_vec& key_values, bool crc_checking) const
	{
		key_values.resize(0);

		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);
		if (!pHeader->m_extended_file_size)
			return true;

		if (pHeader->m_extended_file_size < sizeof(basis_key_value_data_header))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: bad extended file size\n");
			return false;
		}

		if ((pHeader->m_extended_file_ofs.get_uint64() + pHeader->m_extended_file_size.get_uint64()) > data_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: bad extended file offset or size\n");
			return false;
		}

		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		const basis_key_value_data_header* pKVHeader = reinterpret_cast<const basis_key_value_data_header*>(pDataU8 + pHeader->m_extended_file_ofs);
		if (pKVHeader->m_sig != cBASISKVDataSig)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV sig check failed\n");
			return false;
		}

		const uint32_t num_entries = pKVHeader->m_num;
		if (!num_entries)
			return true;

		uint32_t remaining_bytes = pHeader->m_extended_file_size - sizeof(basis_key_value_data_header);
		if (remaining_bytes < (1ULL + sizeof(uint32_t) + 1ULL) * (uint64_t)num_entries)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV section too small\n");
			return false;
		}
		
		if (crc_checking)
		{
			if (crc16((const uint8_t *)pKVHeader + sizeof(basis_key_value_data_header), remaining_bytes, 0) != pKVHeader->m_crc16)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV sig check failed\n");
				return false;
			}
		}

		uint32_t cur_data_ofs = pHeader->m_extended_file_ofs + sizeof(basis_key_value_data_header);

		if (!key_values.try_reserve(num_entries))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: out of memory\n");
			return false;
		}

		for (uint32_t entry_index = 0; entry_index < num_entries; entry_index++)
		{
			uint64_t key_size = 0, val_size = 0;

			for (uint32_t j = 0; j < 5; j++)
			{
				if (remaining_bytes < 1)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV section corrupted (1)\n");
					return false;
				}

				if (cur_data_ofs >= data_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV section corrupted (2)\n");
					return false;
				}

				const uint32_t b = (uint32_t)pDataU8[cur_data_ofs++];
				remaining_bytes--;

				if (!j)
				{
					// Can't exceed UINT8_MAX
					key_size = b;
					if (!key_size)
					{
						BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV section corrupted (3)\n");
						return false;
					}
				}
				else
				{
					// Can't exceed UINT32_MAX
					val_size |= (b << ((j - 1) * 8));
				}

			} // j

			// can't ever fire
			if ((!key_size) || (key_size > 0xFF))
			{
				assert(0);
				return false;
			}

			// can't ever fire
			if (val_size > UINT32_MAX)
			{
				assert(0);
				return false;
			}

			if ((remaining_bytes < (key_size + val_size)))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV section corrupted (4)\n");
				return false;
			}

			if (((size_t)key_size) != key_size)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: key size too large)\n");
				return false;
			}

			basisu::uint8_vec key_data;
			if (!key_data.try_resize((size_t)key_size))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: out of memory\n");
				return false;
			}

			memcpy(key_data.get_ptr(), pDataU8 + cur_data_ofs, (size_t)key_size);

			// key is always null terminated by us here
			if (!key_data.try_push_back(0))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: out of memory\n");
				return false;
			}

			remaining_bytes -= (uint32_t)key_size;
			cur_data_ofs += (uint32_t)key_size;

			basisu::uint8_vec val_data;

			if (val_size)
			{
				if (remaining_bytes < val_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: KV section corrupted (5)\n");
					return false;
				}

				if (((size_t)(val_size + 1)) != (val_size + 1))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: val size too large\n");
					return false;
				}
								
				if (!val_data.try_resize((size_t)(val_size + 1)))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::get_key_values: out of memory\n");
					return false;
				}

				memcpy(val_data.get_ptr(), pDataU8 + cur_data_ofs, (size_t)val_size);
				
				// Value is also always null terminated by us here, independent of its data (binary or string)
				val_data.back() = 0;

				cur_data_ofs += (uint32_t)val_size;
				remaining_bytes -= (uint32_t)val_size;
			}

			key_value* pDst = key_values.enlarge(1);
			pDst->m_key.swap(key_data);
			pDst->m_value.swap(val_data);

		} // entry_index 

		if (remaining_bytes)
		{
			// should we do anything? warning?
			printf("basisu_transcoder::get_key_values: warning: Extra unread bytes after KV data section\n");
		}

		return true;
	}
		
	bool basisu_transcoder::start_transcoding(const void* pData, uint32_t data_size)
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);
		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (m_lowlevel_etc1s_decoder.m_local_endpoints.size())
			{
				m_lowlevel_etc1s_decoder.clear();
			}

			if (pHeader->m_flags & cBASISHeaderFlagUsesGlobalCodebook)
			{
				if (!m_lowlevel_etc1s_decoder.get_global_codebooks())
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: File uses global codebooks, but set_global_codebooks() has not been called\n");
					return false;
				}
				if (!m_lowlevel_etc1s_decoder.get_global_codebooks()->get_endpoints().size())
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: Global codebooks must be unpacked first by calling start_transcoding()\n");
					return false;
				}
				if ((m_lowlevel_etc1s_decoder.get_global_codebooks()->get_endpoints().size() != pHeader->m_total_endpoints) ||
					 (m_lowlevel_etc1s_decoder.get_global_codebooks()->get_selectors().size() != pHeader->m_total_selectors))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: Global codebook size mismatch (wrong codebooks for file).\n");
					return false;
				}
				if (!pHeader->m_tables_file_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted (2)\n");
					return false;
				}
				if (pHeader->m_tables_file_ofs > data_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (4)\n");
					return false;
				}
				if (pHeader->m_tables_file_size > (data_size - pHeader->m_tables_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (5)\n");
					return false;
				}
			}
			else
			{
				if (!pHeader->m_endpoint_cb_file_size || !pHeader->m_selector_cb_file_size || !pHeader->m_tables_file_size)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted (0)\n");
						return false;
				}

				if ((pHeader->m_endpoint_cb_file_ofs > data_size) || (pHeader->m_selector_cb_file_ofs > data_size) || (pHeader->m_tables_file_ofs > data_size))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (1)\n");
					return false;
				}

				if (pHeader->m_endpoint_cb_file_size > (data_size - pHeader->m_endpoint_cb_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (2)\n");
					return false;
				}

				if (pHeader->m_selector_cb_file_size > (data_size - pHeader->m_selector_cb_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (3)\n");
					return false;
				}

				if (pHeader->m_tables_file_size > (data_size - pHeader->m_tables_file_ofs))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: file is corrupted or passed in buffer too small (3)\n");
					return false;
				}

				if (!m_lowlevel_etc1s_decoder.decode_palettes(
					pHeader->m_total_endpoints, pDataU8 + pHeader->m_endpoint_cb_file_ofs, pHeader->m_endpoint_cb_file_size,
					pHeader->m_total_selectors, pDataU8 + pHeader->m_selector_cb_file_ofs, pHeader->m_selector_cb_file_size))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: decode_palettes failed\n");
					return false;
				}
			}

			if (!m_lowlevel_etc1s_decoder.decode_tables(pDataU8 + pHeader->m_tables_file_ofs, pHeader->m_tables_file_size))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::start_transcoding: decode_tables failed\n");
				return false;
			}
		}
		else
		{
			// Nothing special to do for the other formats.
			if (m_lowlevel_etc1s_decoder.m_local_endpoints.size())
			{
				m_lowlevel_etc1s_decoder.clear();
			}
		}
		
		m_ready_to_transcode = true;

		return true;
	}

	bool basisu_transcoder::stop_transcoding()
	{
		m_lowlevel_etc1s_decoder.clear();

		m_ready_to_transcode = false;
		
		return true;
	}

	bool basisu_transcoder::transcode_slice(const void* pData, uint32_t data_size, uint32_t slice_index, void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels, block_format fmt,
		uint32_t output_block_or_pixel_stride_in_bytes, uint32_t decode_flags, uint32_t output_row_pitch_in_blocks_or_pixels, basisu_transcoder_state* pState, void *pAlpha_blocks, uint32_t output_rows_in_pixels, int channel0, int channel1) const
	{
		if (!m_ready_to_transcode)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: must call start_transcoding first\n");
			return false;
		}

		if (decode_flags & cDecodeFlagsPVRTCDecodeToNextPow2)
		{
			// TODO: Not yet supported
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: cDecodeFlagsPVRTCDecodeToNextPow2 currently unsupported\n");
			return false;
		}

		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		if (slice_index >= pHeader->m_total_slices)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: slice_index >= pHeader->m_total_slices\n");
			return false;
		}

		const basis_slice_desc& slice_desc = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs)[slice_index];

		if (!check_slice_desc(pHeader, slice_desc))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: invalid basis_slice_desc\n");
			return false;
		}

		const uint32_t dst_block_width = get_block_width(fmt), dst_block_height = get_block_height(fmt);
										
		if (basis_block_format_is_uncompressed(fmt))
		{
			// Assume the output buffer is orig_width by orig_height
			if (!output_row_pitch_in_blocks_or_pixels)
				output_row_pitch_in_blocks_or_pixels = slice_desc.m_orig_width;

			if (!output_rows_in_pixels)
				output_rows_in_pixels = slice_desc.m_orig_height;

			// Now make sure the output buffer is large enough, or we'll overwrite memory.
			if (output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels))
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: output_blocks_buf_size_in_blocks_or_pixels < (output_rows_in_pixels * output_row_pitch_in_blocks_or_pixels)\n");
				return false;
			}
		}
		else if (fmt == block_format::cFXT1_RGB)
		{
			const uint32_t num_blocks_fxt1_x = (slice_desc.m_orig_width + 7) / 8;
			const uint32_t num_blocks_fxt1_y = (slice_desc.m_orig_height + 3) / 4;
			const uint32_t total_blocks_fxt1 = num_blocks_fxt1_x * num_blocks_fxt1_y;

			if (output_blocks_buf_size_in_blocks_or_pixels < total_blocks_fxt1)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: output_blocks_buf_size_in_blocks_or_pixels < total_blocks_fxt1\n");
				return false;
			}
		}
		else
		{
			const uint32_t dst_num_blocks_x = (slice_desc.m_orig_width + dst_block_width - 1) / dst_block_width;
			const uint32_t dst_num_blocks_y = (slice_desc.m_orig_height + dst_block_height - 1) / dst_block_height;
			const uint32_t dst_total_blocks = dst_num_blocks_x * dst_num_blocks_y;

			if (output_blocks_buf_size_in_blocks_or_pixels < dst_total_blocks)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: output_blocks_buf_size_in_blocks_or_pixels < total_blocks\n");
				return false;
			}
		}
				
		const bool is_xuastc_ldr = basis_tex_format_is_xuastc_ldr((basis_tex_format)(uint32_t)pHeader->m_tex_format);
		const bool is_astc_ldr = basis_tex_format_is_astc_ldr((basis_tex_format)(uint32_t)pHeader->m_tex_format);

		if ((pHeader->m_tex_format == (uint32_t)basis_tex_format::cETC1S) || (pHeader->m_tex_format == (uint32_t)basis_tex_format::cUASTC_LDR_4x4) || is_xuastc_ldr || is_astc_ldr)
		{
			if ((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA))
			{
				// The slice's own block counts are in source blocks, which for XUASTC/ASTC LDR may not be 4x4, so use the 4x4 block counts.
				// (XUASTC/ASTC LDR also requires power of 2 texture dimensions, which its transcode_slice() checks.)
				if ((!basisu::is_pow2(((slice_desc.m_orig_width + 3) >> 2) * 4)) || (!basisu::is_pow2(((slice_desc.m_orig_height + 3) >> 2) * 4)))
				{
					// PVRTC1 only supports power of 2 dimensions
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: PVRTC1 only supports power of 2 dimensions\n");
					return false;
				}
			}
		}

		if (slice_desc.m_file_ofs > data_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: invalid slice_desc.m_file_ofs, or passed in buffer too small\n");
			return false;
		}

		const uint32_t data_size_left = data_size - slice_desc.m_file_ofs;
		if (data_size_left < slice_desc.m_file_size)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: invalid slice_desc.m_file_size, or passed in buffer too small\n");
			return false;
		}
		
		bool status = false;

		if (pHeader->m_tex_format == (int)basis_tex_format::cASTC_HDR_6x6)
		{
			// standard ASTC HDR 6x6
			return m_lowlevel_astc_6x6_hdr_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE)
		{
			// UASTC HDR 6x6i
			return m_lowlevel_astc_6x6_hdr_intermediate_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_HDR_4x4)
		{
			// UASTC HDR 4x4 (which is also standard but constrained ASTC HDR 4x4)
			return m_lowlevel_uastc_4x4_hdr_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_LDR_4x4)
		{
			// UASTC LDR 4x4
			status = m_lowlevel_uastc_ldr_4x4_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if ((is_xuastc_ldr) || (is_astc_ldr))
		{
			// supercompressed XUASTC LDR 4x4-12x12 or standard ASTC LDR 4x4-12x12
			const bool use_astc_srgb_decode_profile = (pHeader->m_flags & cBASISHeaderFlagSRGB) != 0;

			status = m_lowlevel_xuastc_ldr_decoder.transcode_slice((basis_tex_format)(uint32_t)pHeader->m_tex_format, use_astc_srgb_decode_profile, pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cXUBC7)
		{
			// XUBC7 (supercompressed BC7)
			status = m_lowlevel_xubc7_decoder.transcode_slice((basis_tex_format)(uint32_t)pHeader->m_tex_format, pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				output_rows_in_pixels, channel0, channel1, decode_flags);
		}
		else
		{
			// must be ETC1S
			assert(pHeader->m_tex_format == (int)basis_tex_format::cETC1S);
			if (pHeader->m_tex_format != (int)basis_tex_format::cETC1S)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_slice: expected ETC1S format here\n");
				return false;
			}
						
			status = m_lowlevel_etc1s_decoder.transcode_slice(pOutput_blocks, slice_desc.m_num_blocks_x, slice_desc.m_num_blocks_y,
				pDataU8 + slice_desc.m_file_ofs, slice_desc.m_file_size,
				fmt, output_block_or_pixel_stride_in_bytes, (decode_flags & cDecodeFlagsBC1ForbidThreeColorBlocks) == 0, *pHeader, slice_desc, output_row_pitch_in_blocks_or_pixels, pState,
				(decode_flags & cDecodeFlagsOutputHasAlphaIndices) != 0, pAlpha_blocks, output_rows_in_pixels);
		}

		// PVRTC1 levels smaller than 8x8 texels: fill the 2x2 block minimum (see pvrtc1_4_tile_small_level()).
		if (status && ((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA)))
			pvrtc1_4_tile_small_level(pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, (slice_desc.m_orig_width + 3) >> 2, (slice_desc.m_orig_height + 3) >> 2);

		return status;
	}

	int basisu_transcoder::find_first_slice_index(const void* pData, uint32_t data_size, uint32_t image_index, uint32_t level_index) const
	{
		BASISU_NOTE_UNUSED(data_size);

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);
		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		// For very large basis files this search could be painful
		// TODO: Binary search this
		for (uint32_t slice_iter = 0; slice_iter < pHeader->m_total_slices; slice_iter++)
		{
			const basis_slice_desc& slice_desc = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs)[slice_iter];
			if ((slice_desc.m_image_index == image_index) && (slice_desc.m_level_index == level_index))
				return slice_iter;
		}

		BASISU_DEVEL_ERROR("basisu_transcoder::find_first_slice_index: didn't find slice\n");

		return -1;
	}

	int basisu_transcoder::find_slice(const void* pData, uint32_t data_size, uint32_t image_index, uint32_t level_index, bool alpha_data) const
	{
		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::find_slice: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);
		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);
		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs);

		// For very large basis files this search could be painful
		// TODO: Binary search this
		for (uint32_t slice_iter = 0; slice_iter < pHeader->m_total_slices; slice_iter++)
		{
			const basis_slice_desc& slice_desc = pSlice_descs[slice_iter];
			if ((slice_desc.m_image_index == image_index) && (slice_desc.m_level_index == level_index))
			{
				if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
				{
					const bool slice_alpha = (slice_desc.m_flags & cSliceDescFlagsHasAlpha) != 0;
					if (slice_alpha == alpha_data)
						return slice_iter;
				}
				else
				{
					return slice_iter;
				}
			}
		}

		BASISU_DEVEL_ERROR("basisu_transcoder::find_slice: didn't find slice\n");

		return -1;
	}

	void basisu_transcoder::write_opaque_alpha_blocks(
		uint32_t num_blocks_x, uint32_t num_blocks_y,
		void* pOutput_blocks, block_format fmt,
		uint32_t block_stride_in_bytes, uint32_t output_row_pitch_in_blocks_or_pixels)
	{
		// 'num_blocks_y', 'pOutput_blocks' & 'block_stride_in_bytes' unused
		// when disabling BASISD_SUPPORT_ETC2_EAC_A8 *and* BASISD_SUPPORT_DXT5A
		BASISU_NOTE_UNUSED(num_blocks_y);
		BASISU_NOTE_UNUSED(pOutput_blocks);
		BASISU_NOTE_UNUSED(block_stride_in_bytes);

		if (!output_row_pitch_in_blocks_or_pixels)
			output_row_pitch_in_blocks_or_pixels = num_blocks_x;
				
		if ((fmt == block_format::cETC2_EAC_A8) || (fmt == block_format::cETC2_EAC_R11))
		{
#if BASISD_SUPPORT_ETC2_EAC_A8
			eac_block blk;
			blk.m_base = 255;
			blk.m_multiplier = 1;
			blk.m_table = 13;

			// Selectors are all 4's
			memcpy(&blk.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

			for (uint32_t y = 0; y < num_blocks_y; y++)
			{
				uint32_t dst_ofs = y * output_row_pitch_in_blocks_or_pixels * block_stride_in_bytes;
				for (uint32_t x = 0; x < num_blocks_x; x++)
				{
					memcpy((uint8_t*)pOutput_blocks + dst_ofs, &blk, sizeof(blk));
					dst_ofs += block_stride_in_bytes;
				}
			}
#endif
		}
		else if (fmt == block_format::cBC4)
		{
#if BASISD_SUPPORT_DXT5A
			dxt5a_block blk;
			blk.m_endpoints[0] = 255;
			blk.m_endpoints[1] = 255;
			memset(blk.m_selectors, 0, sizeof(blk.m_selectors));

			for (uint32_t y = 0; y < num_blocks_y; y++)
			{
				uint32_t dst_ofs = y * output_row_pitch_in_blocks_or_pixels * block_stride_in_bytes;
				for (uint32_t x = 0; x < num_blocks_x; x++)
				{
					memcpy((uint8_t*)pOutput_blocks + dst_ofs, &blk, sizeof(blk));
					dst_ofs += block_stride_in_bytes;
				}
			}
#endif
		}
	}

	bool basisu_transcoder::transcode_image_level(
		const void* pData, uint32_t data_size,
		uint32_t image_index, uint32_t level_index,
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		transcoder_texture_format fmt,
		uint32_t decode_flags, uint32_t output_row_pitch_in_blocks_or_pixels, basisu_transcoder_state *pState, uint32_t output_rows_in_pixels) const
	{
		const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(fmt);

		if (!m_ready_to_transcode)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: must call start_transcoding() first\n");
			return false;
		}

		//const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;

		if (decode_flags & cDecodeFlagsPVRTCDecodeToNextPow2)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: cDecodeFlagsPVRTCDecodeToNextPow2 currently unsupported\n");
			// TODO: Not yet supported
			return false;
		}

		if (!validate_header_quick(pData, data_size))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: header validation failed\n");
			return false;
		}

		const basis_file_header* pHeader = reinterpret_cast<const basis_file_header*>(pData);

		const uint8_t* pDataU8 = static_cast<const uint8_t*>(pData);

		const basis_slice_desc* pSlice_descs = reinterpret_cast<const basis_slice_desc*>(pDataU8 + pHeader->m_slice_desc_file_ofs);

		const bool basis_file_has_alpha_slices = (pHeader->m_flags & cBASISHeaderFlagHasAlphaSlices) != 0;

		int slice_index = find_first_slice_index(pData, data_size, image_index, level_index);
		if (slice_index < 0)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: failed finding slice index\n");
			// Unable to find the requested image/level 
			return false;
		}

		if (!check_slice_desc(pHeader, pSlice_descs[slice_index]))
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: invalid basis_slice_desc\n");
			return false;
		}

		if ((fmt == transcoder_texture_format::cTFPVRTC1_4_RGBA) && (!basis_file_has_alpha_slices))
		{
			// Switch to PVRTC1 RGB if the input doesn't have alpha.
			fmt = transcoder_texture_format::cTFPVRTC1_4_RGB;
		}
				
		if (pHeader->m_tex_format == (int)basis_tex_format::cETC1S)
		{
			if (pSlice_descs[slice_index].m_flags & cSliceDescFlagsHasAlpha)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file has out of order alpha slice\n");

				// The first slice shouldn't have alpha data in a properly formed basis file
				return false;
			}

			if (basis_file_has_alpha_slices)
			{
				// The alpha data should immediately follow the color data, and have the same resolution.
				if ((slice_index + 1U) >= pHeader->m_total_slices)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file has missing alpha slice\n");
					// basis file is missing the alpha slice
					return false;
				}

				// Basic sanity checks
				if ((pSlice_descs[slice_index + 1].m_flags & cSliceDescFlagsHasAlpha) == 0)
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file has missing alpha slice (flag check)\n");
					// This slice should have alpha data
					return false;
				}

				if ((pSlice_descs[slice_index].m_num_blocks_x != pSlice_descs[slice_index + 1].m_num_blocks_x) || (pSlice_descs[slice_index].m_num_blocks_y != pSlice_descs[slice_index + 1].m_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: alpha basis file slice dimensions bad\n");
					// Alpha slice should have been the same res as the color slice
					return false;
				}
			}
		}
								
		bool status = false;

		const bool is_xuastc_ldr = basis_tex_format_is_xuastc_ldr((basis_tex_format)(uint32_t)pHeader->m_tex_format);
		const bool is_astc_ldr = basis_tex_format_is_astc_ldr((basis_tex_format)(uint32_t)pHeader->m_tex_format);

		if ((pHeader->m_tex_format == (int)basis_tex_format::cETC1S) || (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_LDR_4x4) || is_xuastc_ldr || is_astc_ldr)
		{
			// Only do this on 4x4 LDR formats that supports transcoding to PVRTC1.
			const uint32_t total_slice_blocks = pSlice_descs[slice_index].m_num_blocks_x * pSlice_descs[slice_index].m_num_blocks_y;

			if (((fmt == transcoder_texture_format::cTFPVRTC1_4_RGB) || (fmt == transcoder_texture_format::cTFPVRTC1_4_RGBA)) && (output_blocks_buf_size_in_blocks_or_pixels > total_slice_blocks))
			{
				// The PVRTC1 transcoders write the level's own ((width+3)/4) * ((height+3)/4) blocks, so clear the rest of the buffer.
				// For GL usage, PVRTC1 4bpp image size is (max(width, 8)* max(height, 8) * 4 + 7) / 8. For levels smaller than 8x8 texels,
				// the low-level transcode_image() then fills that 2x2 block minimum after a successful transcode (see pvrtc1_4_tile_small_level()).
				memset(static_cast<uint8_t*>(pOutput_blocks) + total_slice_blocks * bytes_per_block_or_pixel, 0, (output_blocks_buf_size_in_blocks_or_pixels - total_slice_blocks) * bytes_per_block_or_pixel);
			}
		}
		
		if (pHeader->m_tex_format == (int)basis_tex_format::cASTC_HDR_6x6)
		{
			// ASTC HDR 6x6
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			status = m_lowlevel_astc_6x6_hdr_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE)
		{
			// UASTC HDR 6x6
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			status = m_lowlevel_astc_6x6_hdr_intermediate_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_HDR_4x4)
		{
			// UASTC HDR 4x4
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			status = m_lowlevel_uastc_4x4_hdr_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC_LDR_4x4)
		{
			// UASTC LDR 4x4
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			status = m_lowlevel_uastc_ldr_4x4_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (is_xuastc_ldr || is_astc_ldr)
		{
			// XUASTC LDR 4x4-12x12 or ASTC LDR 4x4-12x12
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			const bool use_astc_srgb_decode_profile = (pHeader->m_flags & cBASISHeaderFlagSRGB) != 0;
						
			status = m_lowlevel_xuastc_ldr_decoder.transcode_image((basis_tex_format)(uint32_t)pHeader->m_tex_format, use_astc_srgb_decode_profile, fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else if (pHeader->m_tex_format == (int)basis_tex_format::cXUBC7)
		{
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];

			status = m_lowlevel_xubc7_decoder.transcode_image((basis_tex_format)(uint32_t)pHeader->m_tex_format, fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);
		}
		else 
		{
			// ETC1S
			
			// sanity check
			if (pHeader->m_tex_format != (uint32_t)basis_tex_format::cETC1S)
			{
				BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: unsupported texture format\n");
				return false;
			}

			// ETC1S
			const basis_slice_desc* pSlice_desc = &pSlice_descs[slice_index];
			const basis_slice_desc* pAlpha_slice_desc = basis_file_has_alpha_slices ? &pSlice_descs[slice_index + 1] : nullptr;

			assert((pSlice_desc->m_flags & cSliceDescFlagsHasAlpha) == 0);

			if (pAlpha_slice_desc)
			{
				// Basic sanity checks
				assert((pAlpha_slice_desc->m_flags & cSliceDescFlagsHasAlpha) != 0);
				assert(pSlice_desc->m_num_blocks_x == pAlpha_slice_desc->m_num_blocks_x);
				assert(pSlice_desc->m_num_blocks_y == pAlpha_slice_desc->m_num_blocks_y);
				assert(pSlice_desc->m_level_index == pAlpha_slice_desc->m_level_index);
			}

			// Use the container independent image transcode method.
			status = m_lowlevel_etc1s_decoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t *)pData, data_size, pSlice_desc->m_num_blocks_x, pSlice_desc->m_num_blocks_y, pSlice_desc->m_orig_width, pSlice_desc->m_orig_height, pSlice_desc->m_level_index,
				pSlice_desc->m_file_ofs, pSlice_desc->m_file_size,
				(pAlpha_slice_desc != nullptr) ? (uint32_t)pAlpha_slice_desc->m_file_ofs : 0U, (pAlpha_slice_desc != nullptr) ? (uint32_t)pAlpha_slice_desc->m_file_size : 0U,
				decode_flags, basis_file_has_alpha_slices, pHeader->m_tex_type == cBASISTexTypeVideoFrames, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels);

		} // if (pHeader->m_tex_format == (int)basis_tex_format::cUASTC4x4)
      
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: Returning false\n");
		}
		else
		{
			//BASISU_DEVEL_ERROR("basisu_transcoder::transcode_image_level: Returning true\n");      
		}

		return status;
	}

	uint32_t basis_get_bytes_per_block_or_pixel(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC1_RGB:
		case transcoder_texture_format::cTFBC1_RGB:
		case transcoder_texture_format::cTFBC4_R:
		case transcoder_texture_format::cTFPVRTC1_4_RGB:
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		case transcoder_texture_format::cTFATC_RGB:
		case transcoder_texture_format::cTFPVRTC2_4_RGB:
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		case transcoder_texture_format::cTFETC2_EAC_R11:
			return 8;
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		case transcoder_texture_format::cTFBC6H:
		case transcoder_texture_format::cTFETC2_RGBA:
		case transcoder_texture_format::cTFBC3_RGBA:
		case transcoder_texture_format::cTFBC5_RG:

		case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA:

		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		case transcoder_texture_format::cTFATC_RGBA:
		case transcoder_texture_format::cTFFXT1_RGB:
		case transcoder_texture_format::cTFETC2_EAC_RG11:
			return 16;
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGB_9E5:
			return sizeof(uint32_t);
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		case transcoder_texture_format::cTFRGBA4444:
			return sizeof(uint16_t);
		case transcoder_texture_format::cTFRGB_HALF:
			return sizeof(half_float) * 3;
		case transcoder_texture_format::cTFRGBA_HALF:
			return sizeof(half_float) * 4;
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
			break;
		}
		return 0;
	}

	const char* basis_get_format_name(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC1_RGB: return "ETC1_RGB";
		case transcoder_texture_format::cTFBC1_RGB: return "BC1_RGB";
		case transcoder_texture_format::cTFBC4_R: return "BC4_R";
		case transcoder_texture_format::cTFPVRTC1_4_RGB: return "PVRTC1_4_RGB";
		case transcoder_texture_format::cTFPVRTC1_4_RGBA: return "PVRTC1_4_RGBA";
		case transcoder_texture_format::cTFBC7_RGBA: return "BC7_RGBA";
		case transcoder_texture_format::cTFBC7_ALT: return "BC7_RGBA";
		case transcoder_texture_format::cTFETC2_RGBA: return "ETC2_RGBA";
		case transcoder_texture_format::cTFBC3_RGBA: return "BC3_RGBA";
		case transcoder_texture_format::cTFBC5_RG: return "BC5_RG";
		
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA: return "ASTC_HDR_4X4_RGBA";
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA: return "ASTC_HDR_6X6_RGBA";
		case transcoder_texture_format::cTFATC_RGB: return "ATC_RGB";
		case transcoder_texture_format::cTFATC_RGBA: return "ATC_RGBA";
		case transcoder_texture_format::cTFRGBA32: return "RGBA32";
		case transcoder_texture_format::cTFRGB565: return "RGB565";
		case transcoder_texture_format::cTFBGR565: return "BGR565";
		case transcoder_texture_format::cTFRGBA4444: return "RGBA4444";
		case transcoder_texture_format::cTFRGBA_HALF: return "RGBA_HALF";
		case transcoder_texture_format::cTFRGB_9E5: return "RGB_9E5";
		case transcoder_texture_format::cTFRGB_HALF: return "RGB_HALF";
		case transcoder_texture_format::cTFFXT1_RGB: return "FXT1_RGB";
		case transcoder_texture_format::cTFPVRTC2_4_RGB: return "PVRTC2_4_RGB";
		case transcoder_texture_format::cTFPVRTC2_4_RGBA: return "PVRTC2_4_RGBA";
		case transcoder_texture_format::cTFETC2_EAC_R11: return "ETC2_EAC_R11";
		case transcoder_texture_format::cTFETC2_EAC_RG11: return "ETC2_EAC_RG11";
		case transcoder_texture_format::cTFBC6H: return "BC6H";

		case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA: return "ASTC_LDR_4X4_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA: return "ASTC_LDR_5X4_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA: return "ASTC_LDR_5X5_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA: return "ASTC_LDR_6X5_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA: return "ASTC_LDR_6X6_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA: return "ASTC_LDR_8X5_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA: return "ASTC_LDR_8X6_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA: return "ASTC_LDR_10X5_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA: return "ASTC_LDR_10X6_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA: return "ASTC_LDR_8X8_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA: return "ASTC_LDR_10X8_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA: return "ASTC_LDR_10X10_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA: return "ASTC_LDR_12X10_RGBA";
		case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA: return "ASTC_LDR_12X12_RGBA";

		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
			break;
		}
		return "";
	}

	const char* basis_get_tex_format_name(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cETC1S: return "ETC1S"; break;
		case basis_tex_format::cUASTC_LDR_4x4: return "UASTC LDR 4x4"; break;
		case basis_tex_format::cUASTC_HDR_4x4: return "UASTC_HDR_4x4"; break;
		case basis_tex_format::cASTC_HDR_6x6: return "ASTC_HDR_6x6"; break;
		case basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE: return "UASTC_HDR_6x6"; break;
		case basis_tex_format::cXUASTC_LDR_4x4: return "XUASTC LDR 4x4"; break;
		case basis_tex_format::cXUASTC_LDR_5x4: return "XUASTC LDR 5x4"; break;
		case basis_tex_format::cXUASTC_LDR_5x5: return "XUASTC LDR 5x5"; break;
		case basis_tex_format::cXUASTC_LDR_6x5: return "XUASTC LDR 6x5"; break;
		case basis_tex_format::cXUASTC_LDR_6x6: return "XUASTC LDR 6x6"; break;
		case basis_tex_format::cXUASTC_LDR_8x5: return "XUASTC LDR 8x5"; break;
		case basis_tex_format::cXUASTC_LDR_8x6: return "XUASTC LDR 8x6"; break;
		case basis_tex_format::cXUASTC_LDR_10x5: return "XUASTC LDR 10x5"; break;
		case basis_tex_format::cXUASTC_LDR_10x6: return "XUASTC LDR 10x6"; break;
		case basis_tex_format::cXUASTC_LDR_8x8: return "XUASTC LDR 8x8"; break;
		case basis_tex_format::cXUASTC_LDR_10x8: return "XUASTC LDR 10x8"; break;
		case basis_tex_format::cXUASTC_LDR_10x10: return "XUASTC LDR 10x10"; break;
		case basis_tex_format::cXUASTC_LDR_12x10: return "XUASTC LDR 12x10"; break;
		case basis_tex_format::cXUASTC_LDR_12x12: return "XUASTC LDR 12x12"; break;
		case basis_tex_format::cASTC_LDR_4x4: return "ASTC LDR 4x4"; break;
		case basis_tex_format::cASTC_LDR_5x4: return "ASTC LDR 5x4"; break;
		case basis_tex_format::cASTC_LDR_5x5: return "ASTC LDR 5x5"; break;
		case basis_tex_format::cASTC_LDR_6x5: return "ASTC LDR 6x5"; break;
		case basis_tex_format::cASTC_LDR_6x6: return "ASTC LDR 6x6"; break;
		case basis_tex_format::cASTC_LDR_8x5: return "ASTC LDR 8x5"; break;
		case basis_tex_format::cASTC_LDR_8x6: return "ASTC LDR 8x6"; break;
		case basis_tex_format::cASTC_LDR_10x5: return "ASTC LDR 10x5"; break;
		case basis_tex_format::cASTC_LDR_10x6: return "ASTC LDR 10x6"; break;
		case basis_tex_format::cASTC_LDR_8x8: return "ASTC LDR 8x8"; break;
		case basis_tex_format::cASTC_LDR_10x8: return "ASTC LDR 10x8"; break;
		case basis_tex_format::cASTC_LDR_10x10: return "ASTC LDR 10x10"; break;
		case basis_tex_format::cASTC_LDR_12x10: return "ASTC LDR 12x10"; break;
		case basis_tex_format::cASTC_LDR_12x12: return "ASTC LDR 12x12"; break;
		case basis_tex_format::cXUBC7: return "XUBC7"; break;
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_tex_format_name: Invalid parameter\n");
			break;
		}
		return "";
	}

	const char* basis_get_block_format_name(block_format fmt)
	{
		switch (fmt)
		{
		case block_format::cETC1: return "ETC1";
		case block_format::cBC1: return "BC1";
		case block_format::cPVRTC1_4_RGB: return "PVRTC1_4_RGB";
		case block_format::cPVRTC1_4_RGBA: return "PVRTC1_4_RGBA";
		case block_format::cBC7: return "BC7";
		case block_format::cETC2_RGBA: return "ETC2_RGBA";
		case block_format::cBC3: return "BC3";
		
		case block_format::cASTC_LDR_4x4: return "ASTC_LDR_4x4";
		case block_format::cASTC_LDR_5x4: return "ASTC_LDR_5x4";
		case block_format::cASTC_LDR_5x5: return "ASTC_LDR_5x5";
		case block_format::cASTC_LDR_6x5: return "ASTC_LDR_6x5";
		case block_format::cASTC_LDR_6x6: return "ASTC_LDR_6x6";
		case block_format::cASTC_LDR_8x5: return "ASTC_LDR_8x5";
		case block_format::cASTC_LDR_8x6: return "ASTC_LDR_8x6";
		case block_format::cASTC_LDR_10x5: return "ASTC_LDR_10x5";
		case block_format::cASTC_LDR_10x6: return "ASTC_LDR_10x6";
		case block_format::cASTC_LDR_8x8: return "ASTC_LDR_8x8";
		case block_format::cASTC_LDR_10x8: return "ASTC_LDR_10x8";
		case block_format::cASTC_LDR_10x10: return "ASTC_LDR_10x10";
		case block_format::cASTC_LDR_12x10: return "ASTC_LDR_12x10";
		case block_format::cASTC_LDR_12x12: return "ASTC_LDR_12x12";

		case block_format::cATC_RGB: return "ATC_RGB";
		case block_format::cRGBA32: return "RGBA32";
		case block_format::cRGB565: return "RGB565";
		case block_format::cBGR565: return "BGR565";
		case block_format::cRGBA4444: return "RGBA4444";
		case block_format::cRGBA_HALF: return "RGBA_HALF";
		case block_format::cRGB_HALF: return "RGB_HALF";
		case block_format::cRGB_9E5: return "RGB_9E5";
		case block_format::cUASTC_4x4: return "UASTC_4x4";
		case block_format::cUASTC_HDR_4x4: return "UASTC_HDR_4x4";
		case block_format::cBC6H: return "BC6H";
		case block_format::cASTC_HDR_4x4: return "ASTC_HDR_4x4";
		case block_format::cASTC_HDR_6x6: return "ASTC_HDR_6x6";
		case block_format::cFXT1_RGB: return "FXT1_RGB";
		case block_format::cPVRTC2_4_RGB: return "PVRTC2_4_RGB";
		case block_format::cPVRTC2_4_RGBA: return "PVRTC2_4_RGBA";
		case block_format::cETC2_EAC_R11: return "ETC2_EAC_R11";
		case block_format::cETC2_EAC_RG11: return "ETC2_EAC_RG11";
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
		break;
		}
		return "";
	}

	const char* basis_get_texture_type_name(basis_texture_type tex_type)
	{
		switch (tex_type)
		{
		case cBASISTexType2D: return "2D";
		case cBASISTexType2DArray: return "2D array";
		case cBASISTexTypeCubemapArray: return "cubemap array";
		case cBASISTexTypeVideoFrames: return "video";
		case cBASISTexTypeVolume: return "3D";
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_texture_type_name: Invalid tex_type\n");
			break;
		}
		return "";
	}

	bool basis_transcoder_format_has_alpha(transcoder_texture_format fmt)
	{
		// TODO: Technically ASTC HDR does support alpha, but our ASTC HDR encoders don't yet support it. Unsure what to do here.
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC2_RGBA:
		case transcoder_texture_format::cTFBC3_RGBA:
		
		case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA:

		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA: // technically this ASTC HDR format supports alpha, but we currently don't exploit that in our encoders
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA: // technically this ASTC HDR format supports alpha, but we currently don't exploit that in our encoders
		case transcoder_texture_format::cTFBC7_RGBA:
		case transcoder_texture_format::cTFBC7_ALT:
		case transcoder_texture_format::cTFPVRTC1_4_RGBA:
		case transcoder_texture_format::cTFPVRTC2_4_RGBA:
		case transcoder_texture_format::cTFATC_RGBA:
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGBA4444:
		case transcoder_texture_format::cTFRGBA_HALF:
			return true;
		default:
			break;
		}
		return false;
	}

	bool basis_transcoder_format_is_hdr(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
		case transcoder_texture_format::cTFBC6H:
		case transcoder_texture_format::cTFRGBA_HALF:
		case transcoder_texture_format::cTFRGB_HALF:
		case transcoder_texture_format::cTFRGB_9E5:
			return true;
		default:
			break;
		}
		return false;
	}

	bool basis_is_transcoder_texture_format_astc(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA:
		case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
			return true;
		default:
			break;
		}
		return false;
	}

	basisu::texture_format basis_get_basisu_texture_format(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFETC1_RGB: return basisu::texture_format::cETC1;
		case transcoder_texture_format::cTFBC1_RGB: return basisu::texture_format::cBC1;
		case transcoder_texture_format::cTFBC4_R: return basisu::texture_format::cBC4;
		case transcoder_texture_format::cTFPVRTC1_4_RGB: return basisu::texture_format::cPVRTC1_4_RGB;
		case transcoder_texture_format::cTFPVRTC1_4_RGBA: return basisu::texture_format::cPVRTC1_4_RGBA;
		case transcoder_texture_format::cTFBC7_RGBA: return basisu::texture_format::cBC7;
		case transcoder_texture_format::cTFBC7_ALT: return basisu::texture_format::cBC7;
		case transcoder_texture_format::cTFETC2_RGBA: return basisu::texture_format::cETC2_RGBA;
		case transcoder_texture_format::cTFBC3_RGBA: return basisu::texture_format::cBC3;
		case transcoder_texture_format::cTFBC5_RG: return basisu::texture_format::cBC5;

		case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA: return basisu::texture_format::cASTC_LDR_4x4;
		case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA: return basisu::texture_format::cASTC_LDR_5x4;
		case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA: return basisu::texture_format::cASTC_LDR_5x5;
		case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA: return basisu::texture_format::cASTC_LDR_6x5;
		case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA: return basisu::texture_format::cASTC_LDR_6x6;
		case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA: return basisu::texture_format::cASTC_LDR_8x5;
		case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA: return basisu::texture_format::cASTC_LDR_8x6;
		case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA: return basisu::texture_format::cASTC_LDR_10x5;
		case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA: return basisu::texture_format::cASTC_LDR_10x6;
		case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA: return basisu::texture_format::cASTC_LDR_8x8;
		case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA: return basisu::texture_format::cASTC_LDR_10x8;
		case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA: return basisu::texture_format::cASTC_LDR_10x10;
		case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA: return basisu::texture_format::cASTC_LDR_12x10; 
		case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA: return basisu::texture_format::cASTC_LDR_12x12;

		case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA: return basisu::texture_format::cASTC_HDR_4x4;
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA: return basisu::texture_format::cASTC_HDR_6x6;
		case transcoder_texture_format::cTFBC6H: return basisu::texture_format::cBC6HUnsigned;
		case transcoder_texture_format::cTFATC_RGB: return basisu::texture_format::cATC_RGB;
		case transcoder_texture_format::cTFATC_RGBA: return basisu::texture_format::cATC_RGBA_INTERPOLATED_ALPHA;
		case transcoder_texture_format::cTFRGBA32: return basisu::texture_format::cRGBA32;
		case transcoder_texture_format::cTFRGB565: return basisu::texture_format::cRGB565;
		case transcoder_texture_format::cTFBGR565: return basisu::texture_format::cBGR565;
		case transcoder_texture_format::cTFRGBA4444: return basisu::texture_format::cRGBA4444;
		case transcoder_texture_format::cTFRGBA_HALF: return basisu::texture_format::cRGBA_HALF;
		case transcoder_texture_format::cTFRGB_9E5: return basisu::texture_format::cRGB_9E5;
		case transcoder_texture_format::cTFRGB_HALF: return basisu::texture_format::cRGB_HALF;
		case transcoder_texture_format::cTFFXT1_RGB: return basisu::texture_format::cFXT1_RGB;
		case transcoder_texture_format::cTFPVRTC2_4_RGB: return basisu::texture_format::cPVRTC2_4_RGBA;
		case transcoder_texture_format::cTFPVRTC2_4_RGBA: return basisu::texture_format::cPVRTC2_4_RGBA;
		case transcoder_texture_format::cTFETC2_EAC_R11: return basisu::texture_format::cETC2_R11_EAC;
		case transcoder_texture_format::cTFETC2_EAC_RG11: return basisu::texture_format::cETC2_RG11_EAC;
		default:
			assert(0);
			BASISU_DEVEL_ERROR("basis_get_basisu_texture_format: Invalid fmt\n");
			break;
		}
		return basisu::texture_format::cInvalidTextureFormat;
	}

	bool basis_transcoder_format_is_uncompressed(transcoder_texture_format tex_type)
	{
		switch (tex_type)
		{
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		case transcoder_texture_format::cTFRGBA4444:
		case transcoder_texture_format::cTFRGB_HALF:
		case transcoder_texture_format::cTFRGBA_HALF:
		case transcoder_texture_format::cTFRGB_9E5:
			return true;
		default:
			break;
		}
		return false;
	}

	bool basis_block_format_is_uncompressed(block_format blk_fmt)
	{
		switch (blk_fmt)
		{
		case block_format::cRGB32:
		case block_format::cRGBA32:
		case block_format::cA32:
		case block_format::cRGB565:
		case block_format::cBGR565:
		case block_format::cRGBA4444:
		case block_format::cRGBA4444_COLOR:
		case block_format::cRGBA4444_ALPHA:
		case block_format::cRGBA4444_COLOR_OPAQUE:
		case block_format::cRGBA_HALF:
		case block_format::cRGB_HALF:
		case block_format::cRGB_9E5:
			return true;
		default:
			break;
		}
		return false;
	}
	
	uint32_t basis_get_uncompressed_bytes_per_pixel(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFRGBA32:
		case transcoder_texture_format::cTFRGB_9E5:
			return sizeof(uint32_t); 
		case transcoder_texture_format::cTFRGB565:
		case transcoder_texture_format::cTFBGR565:
		case transcoder_texture_format::cTFRGBA4444:
			return sizeof(uint16_t);
		case transcoder_texture_format::cTFRGB_HALF:
			return sizeof(half_float) * 3;
		case transcoder_texture_format::cTFRGBA_HALF:
			return sizeof(half_float) * 4;
		default:
			break;
		}
		return 0;
	}
	
	uint32_t basis_get_block_width(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
			case transcoder_texture_format::cTFFXT1_RGB:
				return 8;
			case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
				return 6;

			case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA: return 5;
			case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA: return 5;
			case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA: return 6;
			case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA: return 6;
			case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA: return 8;
			case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA: return 8;
			case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA: return 10;
			case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA: return 10;
			case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA: return 8;
			case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA: return 10;
			case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA: return 10;
			case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA: return 12;
			case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA: return 12;

			default:
				break;
		}
		return 4;
	}

	uint32_t basis_get_block_height(transcoder_texture_format fmt)
	{
		switch (fmt)
		{
		case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
			return 6;
					
		case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA: return 5;
		case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA: return 5;
		case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA: return 6;
		case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA: return 5;
		case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA: return 6;
		case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA: return 5;
		case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA: return 6;
		case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA: return 8;
		case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA: return 8;
		case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA: return 10;
		case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA: return 10;
		case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA: return 12;


		default:
			break;
		}
		return 4;
	}

	uint32_t basis_tex_format_get_block_width(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cASTC_HDR_6x6:
		case basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE:
			return 6;
		case basis_tex_format::cXUASTC_LDR_4x4: return 4;
		case basis_tex_format::cXUASTC_LDR_5x4: return 5;
		case basis_tex_format::cXUASTC_LDR_5x5: return 5;
		case basis_tex_format::cXUASTC_LDR_6x5: return 6;
		case basis_tex_format::cXUASTC_LDR_6x6: return 6;
		case basis_tex_format::cXUASTC_LDR_8x5: return 8;
		case basis_tex_format::cXUASTC_LDR_8x6: return 8; 
		case basis_tex_format::cXUASTC_LDR_10x5: return 10;
		case basis_tex_format::cXUASTC_LDR_10x6: return 10;
		case basis_tex_format::cXUASTC_LDR_8x8: return 8;
		case basis_tex_format::cXUASTC_LDR_10x8: return 10;
		case basis_tex_format::cXUASTC_LDR_10x10: return 10;
		case basis_tex_format::cXUASTC_LDR_12x10: return 12; 
		case basis_tex_format::cXUASTC_LDR_12x12: return 12;
		case basis_tex_format::cASTC_LDR_4x4: return 4;
		case basis_tex_format::cASTC_LDR_5x4: return 5;
		case basis_tex_format::cASTC_LDR_5x5: return 5;
		case basis_tex_format::cASTC_LDR_6x5: return 6;
		case basis_tex_format::cASTC_LDR_6x6: return 6;
		case basis_tex_format::cASTC_LDR_8x5: return 8;
		case basis_tex_format::cASTC_LDR_8x6: return 8;
		case basis_tex_format::cASTC_LDR_10x5: return 10;
		case basis_tex_format::cASTC_LDR_10x6: return 10;
		case basis_tex_format::cASTC_LDR_8x8: return 8;
		case basis_tex_format::cASTC_LDR_10x8: return 10;
		case basis_tex_format::cASTC_LDR_10x10: return 10;
		case basis_tex_format::cASTC_LDR_12x10: return 12;
		case basis_tex_format::cASTC_LDR_12x12: return 12;
		default:
			break;
		}
		return 4;
	}

	uint32_t basis_tex_format_get_block_height(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cASTC_HDR_6x6:
		case basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE:
			return 6;
		case basis_tex_format::cXUASTC_LDR_4x4: return 4;
		case basis_tex_format::cXUASTC_LDR_5x4: return 4;
		case basis_tex_format::cXUASTC_LDR_5x5: return 5;
		case basis_tex_format::cXUASTC_LDR_6x5: return 5;
		case basis_tex_format::cXUASTC_LDR_6x6: return 6;
		case basis_tex_format::cXUASTC_LDR_8x5: return 5;
		case basis_tex_format::cXUASTC_LDR_8x6: return 6;
		case basis_tex_format::cXUASTC_LDR_10x5: return 5;
		case basis_tex_format::cXUASTC_LDR_10x6: return 6;
		case basis_tex_format::cXUASTC_LDR_8x8: return 8;
		case basis_tex_format::cXUASTC_LDR_10x8: return 8;
		case basis_tex_format::cXUASTC_LDR_10x10: return 10;
		case basis_tex_format::cXUASTC_LDR_12x10: return 10;
		case basis_tex_format::cXUASTC_LDR_12x12: return 12;
		case basis_tex_format::cASTC_LDR_4x4: return 4;
		case basis_tex_format::cASTC_LDR_5x4: return 4;
		case basis_tex_format::cASTC_LDR_5x5: return 5;
		case basis_tex_format::cASTC_LDR_6x5: return 5;
		case basis_tex_format::cASTC_LDR_6x6: return 6;
		case basis_tex_format::cASTC_LDR_8x5: return 5;
		case basis_tex_format::cASTC_LDR_8x6: return 6;
		case basis_tex_format::cASTC_LDR_10x5: return 5;
		case basis_tex_format::cASTC_LDR_10x6: return 6;
		case basis_tex_format::cASTC_LDR_8x8: return 8;
		case basis_tex_format::cASTC_LDR_10x8: return 8;
		case basis_tex_format::cASTC_LDR_10x10: return 10;
		case basis_tex_format::cASTC_LDR_12x10: return 10;
		case basis_tex_format::cASTC_LDR_12x12: return 12;
		default:
			break;
		}
		return 4;
	}

	bool basis_tex_format_is_hdr(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cUASTC_HDR_4x4:
		case basis_tex_format::cASTC_HDR_6x6:
		case basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE:
			return true;
		default:
			break;
		}
		return false;
	}

	// Given a basis_tex_format (mode or codec), return the corresponding ASTC texture_format with the proper block size from 4x4-12x12.
	basisu::texture_format basis_get_texture_format_from_xuastc_or_astc_ldr_basis_tex_format(basis_tex_format fmt)
	{
		switch (fmt)
		{
		case basis_tex_format::cXUASTC_LDR_4x4:
		case basis_tex_format::cASTC_LDR_4x4:
			return basisu::texture_format::cASTC_LDR_4x4;
		case basis_tex_format::cXUASTC_LDR_5x4:
		case basis_tex_format::cASTC_LDR_5x4:
			return basisu::texture_format::cASTC_LDR_5x4;
		case basis_tex_format::cXUASTC_LDR_5x5:
		case basis_tex_format::cASTC_LDR_5x5:
			return basisu::texture_format::cASTC_LDR_5x5;
		case basis_tex_format::cXUASTC_LDR_6x5:
		case basis_tex_format::cASTC_LDR_6x5:
			return basisu::texture_format::cASTC_LDR_6x5;
		case basis_tex_format::cXUASTC_LDR_6x6:
		case basis_tex_format::cASTC_LDR_6x6:
			return basisu::texture_format::cASTC_LDR_6x6;
		case basis_tex_format::cXUASTC_LDR_8x5:
		case basis_tex_format::cASTC_LDR_8x5:
			return basisu::texture_format::cASTC_LDR_8x5;
		case basis_tex_format::cXUASTC_LDR_8x6:
		case basis_tex_format::cASTC_LDR_8x6:
			return basisu::texture_format::cASTC_LDR_8x6;
		case basis_tex_format::cXUASTC_LDR_10x5:
		case basis_tex_format::cASTC_LDR_10x5:
			return basisu::texture_format::cASTC_LDR_10x5;
		case basis_tex_format::cXUASTC_LDR_10x6:
		case basis_tex_format::cASTC_LDR_10x6:
			return basisu::texture_format::cASTC_LDR_10x6;
		case basis_tex_format::cXUASTC_LDR_8x8:
		case basis_tex_format::cASTC_LDR_8x8:
			return basisu::texture_format::cASTC_LDR_8x8;
		case basis_tex_format::cXUASTC_LDR_10x8:
		case basis_tex_format::cASTC_LDR_10x8:
			return basisu::texture_format::cASTC_LDR_10x8;
		case basis_tex_format::cXUASTC_LDR_10x10:
		case basis_tex_format::cASTC_LDR_10x10:
			return basisu::texture_format::cASTC_LDR_10x10;
		case basis_tex_format::cXUASTC_LDR_12x10:
		case basis_tex_format::cASTC_LDR_12x10:
			return basisu::texture_format::cASTC_LDR_12x10;
		case basis_tex_format::cXUASTC_LDR_12x12:
		case basis_tex_format::cASTC_LDR_12x12:
			return basisu::texture_format::cASTC_LDR_12x12;
		default:
			assert(0);
			return basisu::texture_format::cInvalidTextureFormat;
		}
	}

	// Given any basis_tex_format (mode or codec), return the corresponding transcoder_texture_format with the proper ASTC block size from 4x4-12x12.
	transcoder_texture_format basis_get_transcoder_texture_format_from_xuastc_or_astc_ldr_basis_tex_format(basis_tex_format fmt)
	{
		switch (fmt)
		{
		// XUASTC 4x4-12x12 and ASTC 4x4-12x12
		case basis_tex_format::cXUASTC_LDR_4x4:
		case basis_tex_format::cASTC_LDR_4x4:
			return transcoder_texture_format::cTFASTC_LDR_4x4_RGBA;
		case basis_tex_format::cXUASTC_LDR_5x4:
		case basis_tex_format::cASTC_LDR_5x4:
			return transcoder_texture_format::cTFASTC_LDR_5x4_RGBA;
		case basis_tex_format::cXUASTC_LDR_5x5:
		case basis_tex_format::cASTC_LDR_5x5:
			return transcoder_texture_format::cTFASTC_LDR_5x5_RGBA;
		case basis_tex_format::cXUASTC_LDR_6x5:
		case basis_tex_format::cASTC_LDR_6x5:
			return transcoder_texture_format::cTFASTC_LDR_6x5_RGBA;
		case basis_tex_format::cXUASTC_LDR_6x6:
		case basis_tex_format::cASTC_LDR_6x6:
			return transcoder_texture_format::cTFASTC_LDR_6x6_RGBA;
		case basis_tex_format::cXUASTC_LDR_8x5:
		case basis_tex_format::cASTC_LDR_8x5:
			return transcoder_texture_format::cTFASTC_LDR_8x5_RGBA;
		case basis_tex_format::cXUASTC_LDR_8x6:
		case basis_tex_format::cASTC_LDR_8x6:
			return transcoder_texture_format::cTFASTC_LDR_8x6_RGBA;
		case basis_tex_format::cXUASTC_LDR_10x5:
		case basis_tex_format::cASTC_LDR_10x5:
			return transcoder_texture_format::cTFASTC_LDR_10x5_RGBA;
		case basis_tex_format::cXUASTC_LDR_10x6:
		case basis_tex_format::cASTC_LDR_10x6:
			return transcoder_texture_format::cTFASTC_LDR_10x6_RGBA;
		case basis_tex_format::cXUASTC_LDR_8x8:
		case basis_tex_format::cASTC_LDR_8x8:
			return transcoder_texture_format::cTFASTC_LDR_8x8_RGBA;
		case basis_tex_format::cXUASTC_LDR_10x8:
		case basis_tex_format::cASTC_LDR_10x8:
			return transcoder_texture_format::cTFASTC_LDR_10x8_RGBA;
		case basis_tex_format::cXUASTC_LDR_10x10:
		case basis_tex_format::cASTC_LDR_10x10:
			return transcoder_texture_format::cTFASTC_LDR_10x10_RGBA;
		case basis_tex_format::cXUASTC_LDR_12x10:
		case basis_tex_format::cASTC_LDR_12x10:
			return transcoder_texture_format::cTFASTC_LDR_12x10_RGBA;
		case basis_tex_format::cXUASTC_LDR_12x12:
		case basis_tex_format::cASTC_LDR_12x12:
			return transcoder_texture_format::cTFASTC_LDR_12x12_RGBA;

		// XUBC7 transcodes near-losslessly to ASTC LDR 4x4
		case basis_tex_format::cXUBC7:
			return transcoder_texture_format::cTFASTC_4x4_RGBA;
		
		// ETC1S/UASTC LDR 4x4
		case basis_tex_format::cETC1S:
		case basis_tex_format::cUASTC_LDR_4x4:
			return transcoder_texture_format::cTFASTC_LDR_4x4_RGBA;

		// HDR formats
		case basis_tex_format::cUASTC_HDR_4x4:
			return transcoder_texture_format::cTFASTC_HDR_4x4_RGBA;

		case basis_tex_format::cASTC_HDR_6x6:
		case basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE:
			return transcoder_texture_format::cTFASTC_HDR_6x6_RGBA;

		default:
			assert(0);
			return transcoder_texture_format::cTFASTC_LDR_4x4_RGBA;
		}
	}

	transcoder_texture_format basis_get_transcoder_texture_format_from_basis_tex_format(basis_tex_format fmt)
	{
		return basis_get_transcoder_texture_format_from_xuastc_or_astc_ldr_basis_tex_format(fmt);
	}
	
	// For a given basis_tex_format (mode or codec), is the specified transcoder_texture_format supported?
	bool basis_is_format_supported(transcoder_texture_format tex_type, basis_tex_format fmt)
	{
		if ((fmt == basis_tex_format::cASTC_HDR_6x6) || (fmt == basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE))
		{
			// RDO UASTC HDR 6x6, or our custom intermediate format
#if BASISD_SUPPORT_UASTC_HDR
			switch (tex_type)
			{
			case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
			case transcoder_texture_format::cTFBC6H:
			case transcoder_texture_format::cTFRGBA_HALF:
			case transcoder_texture_format::cTFRGB_HALF:
			case transcoder_texture_format::cTFRGB_9E5:
				return true;
			default:
				break;
			}
#endif
		}
		else if (fmt == basis_tex_format::cUASTC_HDR_4x4)
		{
			// UASTC HDR 4x4
#if BASISD_SUPPORT_UASTC_HDR
			switch (tex_type)
			{
			case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
			case transcoder_texture_format::cTFBC6H:
			case transcoder_texture_format::cTFRGBA_HALF:
			case transcoder_texture_format::cTFRGB_HALF:
			case transcoder_texture_format::cTFRGB_9E5:
				return true;
			default:
				break;
			}
#endif
		}
		else if (fmt == basis_tex_format::cUASTC_LDR_4x4)
		{
			// UASTC LDR 4x4
#if BASISD_SUPPORT_UASTC
			// IMPORTANT : This is defined as the formats which DON'T support UASTC LDR 4x4 transcoding.
			switch (tex_type)
			{
			// These niche formats aren't currently supported for UASTC LDR 4x4 - everything else is.
			case transcoder_texture_format::cTFPVRTC2_4_RGB:
			case transcoder_texture_format::cTFPVRTC2_4_RGBA:
			case transcoder_texture_format::cTFATC_RGB:
			case transcoder_texture_format::cTFATC_RGBA:
			case transcoder_texture_format::cTFFXT1_RGB:
			// UASTC LDR 4x4 doesn't support transcoding to HDR formats
			case transcoder_texture_format::cTFASTC_HDR_4x4_RGBA:
			case transcoder_texture_format::cTFASTC_HDR_6x6_RGBA:
			case transcoder_texture_format::cTFBC6H:
			case transcoder_texture_format::cTFRGBA_HALF:
			case transcoder_texture_format::cTFRGB_HALF:
			case transcoder_texture_format::cTFRGB_9E5:
			case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA:
			case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA:
				return false;
			default:
				return true;
			}
#endif
		}
		else if ( (basis_tex_format_is_xuastc_ldr(fmt)) || (basis_tex_format_is_astc_ldr(fmt)) )
		{
			// XUASTC LDR 4x4-12x12 or ASTC LDR 4x4-12x12

#if BASISD_SUPPORT_XUASTC
			switch (tex_type)
			{
			case transcoder_texture_format::cTFBC1_RGB:
			case transcoder_texture_format::cTFBC3_RGBA:
			case transcoder_texture_format::cTFBC4_R:
			case transcoder_texture_format::cTFBC5_RG:
			case transcoder_texture_format::cTFBC7_RGBA:
			case transcoder_texture_format::cTFETC1_RGB:
			case transcoder_texture_format::cTFETC2_RGBA:
			case transcoder_texture_format::cTFETC2_EAC_R11:
			case transcoder_texture_format::cTFETC2_EAC_RG11:
			case transcoder_texture_format::cTFPVRTC1_4_RGB:
			case transcoder_texture_format::cTFPVRTC1_4_RGBA:
			// Uncompressed formats
			case transcoder_texture_format::cTFRGBA32:
			case transcoder_texture_format::cTFRGB565:
			case transcoder_texture_format::cTFBGR565:
			case transcoder_texture_format::cTFRGBA4444:
				return true;
			default:
				break;
			}

			// Ensure they're using the block size for ASTC LDR that matches the XUASTC format's block size.
			switch (fmt)
			{
			case basis_tex_format::cXUASTC_LDR_4x4:
			case basis_tex_format::cASTC_LDR_4x4:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_4x4_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_5x4:
			case basis_tex_format::cASTC_LDR_5x4:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_5x4_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_5x5:
			case basis_tex_format::cASTC_LDR_5x5:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_5x5_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_6x5:
			case basis_tex_format::cASTC_LDR_6x5:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_6x5_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_6x6:
			case basis_tex_format::cASTC_LDR_6x6:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_6x6_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_8x5:
			case basis_tex_format::cASTC_LDR_8x5:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_8x5_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_8x6:
			case basis_tex_format::cASTC_LDR_8x6:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_8x6_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_10x5:
			case basis_tex_format::cASTC_LDR_10x5:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_10x5_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_10x6:
			case basis_tex_format::cASTC_LDR_10x6:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_10x6_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_8x8:
			case basis_tex_format::cASTC_LDR_8x8:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_8x8_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_10x8:
			case basis_tex_format::cASTC_LDR_10x8:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_10x8_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_10x10:
			case basis_tex_format::cASTC_LDR_10x10:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_10x10_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_12x10:
			case basis_tex_format::cASTC_LDR_12x10:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_12x10_RGBA)
					return true;
				break;
			}
			case basis_tex_format::cXUASTC_LDR_12x12:
			case basis_tex_format::cASTC_LDR_12x12:
			{
				if (tex_type == transcoder_texture_format::cTFASTC_LDR_12x12_RGBA)
					return true;
				break;
			}
			default:
				break;
			}
#endif
		}
		else if (fmt == basis_tex_format::cXUBC7)
		{
			// XUBC7
#if BASISD_SUPPORT_XUASTC
			switch (tex_type)
			{
			case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
			case transcoder_texture_format::cTFBC1_RGB:
			case transcoder_texture_format::cTFBC3_RGBA:
			case transcoder_texture_format::cTFBC4_R:
			case transcoder_texture_format::cTFBC5_RG:
			case transcoder_texture_format::cTFBC7_RGBA:
			case transcoder_texture_format::cTFETC1_RGB:
			case transcoder_texture_format::cTFETC2_RGBA:
			case transcoder_texture_format::cTFETC2_EAC_R11:
			case transcoder_texture_format::cTFETC2_EAC_RG11:
			case transcoder_texture_format::cTFPVRTC1_4_RGB:
			case transcoder_texture_format::cTFPVRTC1_4_RGBA:
			// Uncompressed formats
			case transcoder_texture_format::cTFRGBA32:
			case transcoder_texture_format::cTFRGB565:
			case transcoder_texture_format::cTFBGR565:
			case transcoder_texture_format::cTFRGBA4444:
				return true;
			default:
				break;
			}
#endif
		}
		else
		{
			// ETC1S
			switch (tex_type)
			{
			// ETC1 and uncompressed are always supported.
			case transcoder_texture_format::cTFETC1_RGB:
			case transcoder_texture_format::cTFRGBA32:
			case transcoder_texture_format::cTFRGB565:
			case transcoder_texture_format::cTFBGR565:
			case transcoder_texture_format::cTFRGBA4444:
				return true;
#if BASISD_SUPPORT_DXT1
			case transcoder_texture_format::cTFBC1_RGB:
				return true;
#endif
#if BASISD_SUPPORT_DXT5A
			case transcoder_texture_format::cTFBC4_R:
			case transcoder_texture_format::cTFBC5_RG:
				return true;
#endif
#if BASISD_SUPPORT_DXT1 && BASISD_SUPPORT_DXT5A
			case transcoder_texture_format::cTFBC3_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_PVRTC1
			case transcoder_texture_format::cTFPVRTC1_4_RGB:
			case transcoder_texture_format::cTFPVRTC1_4_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_BC7_MODE5
			case transcoder_texture_format::cTFBC7_RGBA:
			case transcoder_texture_format::cTFBC7_ALT:
				return true;
#endif
#if BASISD_SUPPORT_ETC2_EAC_A8
			case transcoder_texture_format::cTFETC2_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_ASTC		
			case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_ATC
			case transcoder_texture_format::cTFATC_RGB:
			case transcoder_texture_format::cTFATC_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_FXT1
			case transcoder_texture_format::cTFFXT1_RGB:
				return true;
#endif
#if BASISD_SUPPORT_PVRTC2
			case transcoder_texture_format::cTFPVRTC2_4_RGB:
			case transcoder_texture_format::cTFPVRTC2_4_RGBA:
				return true;
#endif
#if BASISD_SUPPORT_ETC2_EAC_RG11
			case transcoder_texture_format::cTFETC2_EAC_R11:
			case transcoder_texture_format::cTFETC2_EAC_RG11:
				return true;
#endif
			default:
				break;
			}
		}

		return false;
	}

	// ------------------------------------------------------------------------------------------------------ 
	// UASTC LDR 4x4
	// ------------------------------------------------------------------------------------------------------ 

#if BASISD_SUPPORT_UASTC
	const astc_bc7_common_partition2_desc g_astc_bc7_common_partitions2[TOTAL_ASTC_BC7_COMMON_PARTITIONS2] =
	{
		{ 0, 28, false  }, { 1, 20, false }, { 2, 16, true }, { 3, 29, false },
		{ 4, 91, true }, { 5, 9, false }, { 6, 107, true }, { 7, 72, true },
		{ 8, 149, false }, { 9, 204, true }, { 10, 50, false }, { 11, 114, true },
		{ 12, 496, true }, { 13, 17, true }, { 14, 78, false }, { 15, 39, true },
		{ 17, 252, true }, { 18, 828, true }, { 19, 43, false }, { 20, 156, false },
		{ 21, 116, false }, { 22, 210, true }, { 23, 476, true }, { 24, 273, false },
		{ 25, 684, true }, { 26, 359, false }, { 29, 246, true }, { 32, 195, true },
		{ 33, 694, true }, { 52, 524, true }
	};

	const bc73_astc2_common_partition_desc g_bc7_3_astc2_common_partitions[TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS] =
	{
		{ 10, 36, 4 }, { 11, 48, 4 },	{ 0, 61, 3 }, { 2, 137, 4 },
		{ 8, 161, 5 }, { 13, 183, 4 }, { 1, 226, 2 }, { 33, 281, 2 },
		{ 40, 302, 3 }, { 20, 307, 4 }, { 21, 479, 0 }, { 58, 495, 3 },
		{ 3, 593, 0 }, { 32, 594, 2 }, { 59, 605, 1 }, { 34, 799, 3 },
		{ 20, 812, 1 }, { 14, 988, 4 }, { 31, 993, 3 }
	};

	const astc_bc7_common_partition3_desc g_astc_bc7_common_partitions3[TOTAL_ASTC_BC7_COMMON_PARTITIONS3] =
	{
		{ 4, 260, 0 }, { 8, 74, 5 }, { 9, 32, 5 }, { 10, 156, 2 },
		{ 11, 183, 2 }, { 12, 15, 0 }, { 13, 745, 4 }, { 20, 0, 1 },
		{ 35, 335, 1 }, { 36, 902, 5 }, { 57, 254, 0 }
	};

	const uint8_t g_astc_to_bc7_partition_index_perm_tables[6][3] = { { 0, 1, 2 }, { 1, 2, 0 }, { 2, 0, 1 },	{ 2, 1, 0 }, { 0, 2, 1 }, { 1, 0, 2 } };

	const uint8_t g_bc7_to_astc_partition_index_perm_tables[6][3] = { { 0, 1, 2 }, { 2, 0, 1 }, { 1, 2, 0 },	{ 2, 1, 0 }, { 0, 2, 1 }, { 1, 0, 2 } };

	uint32_t bc7_convert_partition_index_3_to_2(uint32_t p, uint32_t k)
	{
		assert(k < 6);
		switch (k >> 1)
		{
		case 0:
			if (p <= 1)
				p = 0;
			else
				p = 1;
			break;
		case 1:
			if (p == 0)
				p = 0;
			else
				p = 1;
			break;
		case 2:
			if ((p == 0) || (p == 2))
				p = 0;
			else
				p = 1;
			break;
		}
		if (k & 1)
			p = 1 - p;
		return p;
	}

	static const uint8_t g_zero_pattern[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

	const uint8_t g_astc_bc7_patterns2[TOTAL_ASTC_BC7_COMMON_PARTITIONS2][16] =
	{
		{ 0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1 }, { 0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1 }, { 1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0 }, { 0,0,0,1,0,0,1,1,0,0,1,1,0,1,1,1 },
		{ 1,1,1,1,1,1,1,0,1,1,1,0,1,1,0,0 }, { 0,0,1,1,0,1,1,1,0,1,1,1,1,1,1,1 }, { 1,1,1,0,1,1,0,0,1,0,0,0,0,0,0,0 }, { 1,1,1,1,1,1,1,0,1,1,0,0,1,0,0,0 },
		{ 0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,1 }, { 1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0 }, { 0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,1,1,1,0,1,0,0,0 },
		{ 1,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0 }, { 1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0 }, { 0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0 },
		{ 1,0,0,0,1,1,1,0,1,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,0,1,1,1,0,0,0,1 }, { 0,1,1,1,0,0,1,1,0,0,0,1,0,0,0,0 }, { 0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0 },
		{ 0,0,0,0,1,0,0,0,1,1,0,0,1,1,1,0 }, { 1,1,1,1,1,1,1,1,0,1,1,1,0,0,1,1 }, { 1,0,0,0,1,1,0,0,1,1,0,0,1,1,1,0 }, { 0,0,1,1,0,0,0,1,0,0,0,1,0,0,0,0 },
		{ 1,1,1,1,0,1,1,1,0,1,1,1,0,0,1,1 }, { 0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0 }, { 1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1 }, { 1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0 },
		{ 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0 }, { 1,0,0,1,0,0,1,1,0,1,1,0,1,1,0,0 }
	};

	const uint8_t g_astc_bc7_patterns3[TOTAL_ASTC_BC7_COMMON_PARTITIONS3][16] =
	{
		{ 0,0,0,0,0,0,0,0,1,1,2,2,1,1,2,2 }, { 1,1,1,1,1,1,1,1,0,0,0,0,2,2,2,2 }, { 1,1,1,1,0,0,0,0,0,0,0,0,2,2,2,2 },	{ 1,1,1,1,2,2,2,2,0,0,0,0,0,0,0,0 },
		{ 1,1,2,0,1,1,2,0,1,1,2,0,1,1,2,0 }, { 0,1,1,2,0,1,1,2,0,1,1,2,0,1,1,2 }, { 0,2,1,1,0,2,1,1,0,2,1,1,0,2,1,1 },	{ 2,0,0,0,2,0,0,0,2,1,1,1,2,1,1,1 },
		{ 2,0,1,2,2,0,1,2,2,0,1,2,2,0,1,2 }, { 1,1,1,1,0,0,0,0,2,2,2,2,1,1,1,1 }, { 0,0,2,2,0,0,1,1,0,0,1,1,0,0,2,2 }
	};

	const uint8_t g_bc7_3_astc2_patterns2[TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS][16] =
	{
		{ 0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0 }, { 0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0 }, { 1,1,0,0,1,1,0,0,1,0,0,0,0,0,0,0 },	{ 0,0,0,0,0,0,0,1,0,0,1,1,0,0,1,1 },
		{ 1,1,1,1,1,1,1,1,0,0,0,0,1,1,1,1 }, { 0,1,0,0,0,1,0,0,0,1,0,0,0,1,0,0 }, { 0,0,0,1,0,0,1,1,1,1,1,1,1,1,1,1 },	{ 0,1,1,1,0,0,1,1,0,0,1,1,0,0,1,1 },
		{ 1,1,0,0,0,0,0,0,0,0,1,1,1,1,0,0 }, { 0,1,1,1,0,1,1,1,0,0,0,0,0,0,0,0 }, { 0,0,0,0,0,0,0,0,1,1,1,0,1,1,1,0 },	{ 1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0 },
		{ 0,1,1,1,0,0,1,1,0,0,0,0,0,0,0,0 }, { 0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1 }, { 1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,0 },	{ 1,1,0,0,1,1,0,0,1,1,0,0,1,0,0,0 },
		{ 1,1,1,1,1,1,1,1,1,0,0,0,1,0,0,0 }, { 0,0,1,1,0,1,1,0,1,1,0,0,1,0,0,0 }, { 1,1,1,1,0,1,1,1,0,0,0,0,0,0,0,0 }
	};

	const uint8_t g_astc_bc7_pattern2_anchors[TOTAL_ASTC_BC7_COMMON_PARTITIONS2][3] =
	{
		{ 0, 2 }, { 0, 3 }, { 1, 0 }, { 0, 3 }, { 7, 0 }, { 0, 2 }, { 3, 0 }, { 7, 0 },
		{ 0, 11 }, { 2, 0 }, { 0, 7 }, { 11, 0 }, { 3, 0 }, { 8, 0 }, { 0, 4 }, { 12, 0 },
		{ 1, 0 }, { 8, 0 }, { 0, 1 }, { 0, 2 }, { 0, 4 }, { 8, 0 }, { 1, 0 }, { 0, 2 },
		{ 4, 0 }, { 0, 1 }, { 4, 0 }, { 1, 0 }, { 4, 0 }, { 1, 0 }
	};

	const uint8_t g_astc_bc7_pattern3_anchors[TOTAL_ASTC_BC7_COMMON_PARTITIONS3][3] =
	{
		{ 0, 8, 10 },	{ 8, 0, 12 }, { 4, 0, 12 }, { 8, 0, 4 }, { 3, 0, 2 }, { 0, 1, 3 }, { 0, 2, 1 }, { 1, 9, 0 }, { 1, 2, 0 }, { 4, 0, 8 }, { 0, 6, 2 }
	};

	const uint8_t g_bc7_3_astc2_patterns2_anchors[TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS][3] =
	{
		{ 0, 4 }, { 0, 2 }, { 2, 0 }, { 0, 7 }, { 8, 0 }, { 0, 1 }, { 0, 3 }, { 0, 1 }, { 2, 0 }, { 0, 1 }, { 0, 8 }, { 2, 0 }, { 0, 1 }, { 0, 7 }, { 12, 0 }, { 2, 0 }, { 9, 0 }, { 0, 2 }, { 4, 0 }
	};

	const uint32_t g_uastc_mode_huff_codes[TOTAL_UASTC_MODES + 1][2] =
	{
		{ 0x1, 4 },
		{ 0x35, 6 },
		{ 0x1D, 5 },
		{ 0x3, 5 },

		{ 0x13, 5 },
		{ 0xB, 5 },
		{ 0x1B, 5 },
		{ 0x7, 5 },

		{ 0x17, 5 },
		{ 0xF, 5 },
		{ 0x2, 3 },
		{ 0x0, 2 },

		{ 0x6, 3 },
		{ 0x1F, 5 },
		{ 0xD, 5 },
		{ 0x5, 7 },

		{ 0x15, 6 },
		{ 0x25, 6 },
		{ 0x9, 4 },
		{ 0x45, 7 } // future expansion
	};

	// If g_uastc_mode_huff_codes[] changes this table must be updated!
	static const uint8_t g_uastc_huff_modes[128] =
	{
		11,0,10,3,11,15,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,16,12,8,11,18,10,6,11,2,12,13,11,0,10,3,11,17,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,1,12,8,11,18,10,6,11,2,12,13,11,0,10,3,11,
		19,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,16,12,8,11,18,10,6,11,2,12,13,11,0,10,3,11,17,12,7,11,18,10,5,11,14,12,9,11,0,10,4,11,1,12,8,11,18,10,6,11,2,12,13
	};

	const uint8_t g_uastc_mode_weight_bits[TOTAL_UASTC_MODES] = { 4, 2, 3, 2, 2, 3, 2, 2,			0,  2, 4, 2, 3, 1, 2,			4, 2, 2,     5 };
	const uint8_t g_uastc_mode_weight_ranges[TOTAL_UASTC_MODES] = { 8, 2, 5, 2, 2, 5, 2, 2,			0,  2, 8, 2, 5, 0, 2,			8, 2, 2,     11 };
	const uint8_t g_uastc_mode_endpoint_ranges[TOTAL_UASTC_MODES] = { 19, 20, 8, 7, 12, 20, 18, 12,	0,  8, 13, 13, 19, 20, 20,		20, 20, 20,  11 };
	const uint8_t g_uastc_mode_subsets[TOTAL_UASTC_MODES] = { 1, 1, 2, 3, 2, 1, 1, 2,			0,  2, 1, 1, 1, 1, 1,			1, 2, 1,     1 };
	const uint8_t g_uastc_mode_planes[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 2, 1,			0,  1, 1, 2, 1, 2, 1,			1, 1, 2,     1 };
	const uint8_t g_uastc_mode_comps[TOTAL_UASTC_MODES] = { 3, 3, 3, 3, 3, 3, 3, 3,			4,  4, 4, 4, 4, 4, 4,			2, 2, 2,     3 };
	const uint8_t g_uastc_mode_has_etc1_bias[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 1, 1,			0,  1, 0, 0, 0, 1, 1,			1, 1, 1,     1 };
	const uint8_t g_uastc_mode_has_bc1_hint0[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 1, 1,			0,  1, 1, 1, 1, 1, 1,			1, 1, 1,     1 };
	const uint8_t g_uastc_mode_has_bc1_hint1[TOTAL_UASTC_MODES] = { 1, 1, 1, 1, 1, 1, 1, 1,			0,  1, 0, 0, 0, 1, 1,			1, 1, 1,     1 };
	const uint8_t g_uastc_mode_cem[TOTAL_UASTC_MODES] = { 8, 8, 8, 8, 8, 8, 8, 8,         0,  12, 12, 12, 12, 12, 12,   4, 4, 4,     8 };
	const uint8_t g_uastc_mode_has_alpha[TOTAL_UASTC_MODES] = { 0, 0, 0, 0, 0, 0, 0, 0,			1,  1, 1, 1, 1, 1, 1,			1, 1, 1,     0 };
	const uint8_t g_uastc_mode_is_la[TOTAL_UASTC_MODES] = { 0, 0, 0, 0, 0, 0, 0, 0,			0,  0, 0, 0, 0, 0, 0,			1, 1, 1,     0 };
	const uint8_t g_uastc_mode_total_hint_bits[TOTAL_UASTC_MODES] = { 15, 15, 15, 15, 15, 15, 15, 15, 0, 23, 17, 17, 17, 23, 23, 23, 23, 23, 15 };

	// bits, trits, quints
	const int g_astc_bise_range_table[TOTAL_ASTC_RANGES][3] =
	{
		{ 1, 0, 0 }, // 0-1 0
		{ 0, 1, 0 }, // 0-2 1
		{ 2, 0, 0 }, // 0-3 2
		{ 0, 0, 1 }, // 0-4 3

		{ 1, 1, 0 }, // 0-5 4
		{ 3, 0, 0 }, // 0-7 5
		{ 1, 0, 1 }, // 0-9 6
		{ 2, 1, 0 }, // 0-11 7

		{ 4, 0, 0 }, // 0-15 8
		{ 2, 0, 1 }, // 0-19 9
		{ 3, 1, 0 }, // 0-23 10
		{ 5, 0, 0 }, // 0-31 11

		{ 3, 0, 1 }, // 0-39 12
		{ 4, 1, 0 }, // 0-47 13
		{ 6, 0, 0 }, // 0-63 14
		{ 4, 0, 1 }, // 0-79 15

		{ 5, 1, 0 }, // 0-95 16
		{ 7, 0, 0 }, // 0-127 17
		{ 5, 0, 1 }, // 0-159 18
		{ 6, 1, 0 }, // 0-191 19

		{ 8, 0, 0 }, // 0-255 20
	};

	int astc_get_levels(int range)
	{
		assert(range < (int)BC7ENC_TOTAL_ASTC_RANGES);
		return (1 + 2 * g_astc_bise_range_table[range][1] + 4 * g_astc_bise_range_table[range][2]) << g_astc_bise_range_table[range][0];
	}

	// g_astc_unquant[] is the inverse of g_astc_sorted_order_unquant[]
	astc_quant_bin g_astc_unquant[BC7ENC_TOTAL_ASTC_RANGES][256]; // [ASTC encoded endpoint index]

	// Taken right from the ASTC spec.
	static struct
	{
		const char* m_pB_str;
		uint32_t m_c;
	} g_astc_endpoint_unquant_params[BC7ENC_TOTAL_ASTC_RANGES] =
	{
		{ "", 0 },
		{ "", 0 },
		{ "", 0 },
		{ "", 0 },
		{ "000000000", 204, },  // 0-5
		{ "", 0 },
		{ "000000000", 113, },  // 0-9
		{ "b000b0bb0", 93 },    // 0-11
		{ "", 0 },
		{ "b0000bb00", 54 },    // 0-19
		{ "cb000cbcb", 44 },   // 0-23
		{ "", 0 },
		{ "cb0000cbc", 26 },   // 0-39
		{ "dcb000dcb", 22 },   // 0-47
		{ "", 0 },
		{ "dcb0000dc", 13 },   // 0-79
		{ "edcb000ed", 11 },   // 0-95
		{ "", 0 },
		{ "edcb0000e", 6 },    // 0-159
		{ "fedcb000f", 5 },     // 0-191
		{ "", 0 },
	};

	bool astc_is_valid_endpoint_range(uint32_t range)
	{
		if ((g_astc_bise_range_table[range][1] == 0) && (g_astc_bise_range_table[range][2] == 0))
			return true;

		return g_astc_endpoint_unquant_params[range].m_c != 0;
	}

	uint32_t unquant_astc_endpoint(uint32_t packed_bits, uint32_t packed_trits, uint32_t packed_quints, uint32_t range)
	{
		assert(range < BC7ENC_TOTAL_ASTC_RANGES);

		const uint32_t bits = g_astc_bise_range_table[range][0];
		const uint32_t trits = g_astc_bise_range_table[range][1];
		const uint32_t quints = g_astc_bise_range_table[range][2];

		uint32_t val = 0;
		if ((!trits) && (!quints))
		{
			assert(!packed_trits && !packed_quints);

			int bits_left = 8;
			while (bits_left > 0)
			{
				uint32_t v = packed_bits;

				int n = basisu::minimumi(bits_left, bits);
				if (n < (int)bits)
					v >>= (bits - n);

				assert(v < (1U << n));

				val |= (v << (bits_left - n));
				bits_left -= n;
			}
		}
		else
		{
			const uint32_t A = (packed_bits & 1) ? 511 : 0;
			const uint32_t C = g_astc_endpoint_unquant_params[range].m_c;
			const uint32_t D = trits ? packed_trits : packed_quints;

			assert(C);

			uint32_t B = 0;
			for (uint32_t i = 0; i < 9; i++)
			{
				B <<= 1;

				char c = g_astc_endpoint_unquant_params[range].m_pB_str[i];
				if (c != '0')
				{
					c -= 'a';
					B |= ((packed_bits >> c) & 1);
				}
			}

			val = D * C + B;
			val = val ^ A;
			val = (A & 0x80) | (val >> 2);
		}

		return val;
	}

	uint32_t unquant_astc_endpoint_val(uint32_t packed_val, uint32_t range)
	{
		assert(range < BC7ENC_TOTAL_ASTC_RANGES);
		assert(packed_val < (uint32_t)astc_get_levels(range));

		const uint32_t bits = g_astc_bise_range_table[range][0];
		const uint32_t trits = g_astc_bise_range_table[range][1];
		const uint32_t quints = g_astc_bise_range_table[range][2];

		if ((!trits) && (!quints))
			return unquant_astc_endpoint(packed_val, 0, 0, range);
		else if (trits)
			return unquant_astc_endpoint(packed_val & ((1 << bits) - 1), packed_val >> bits, 0, range);
		else
			return unquant_astc_endpoint(packed_val & ((1 << bits) - 1), 0, packed_val >> bits, range);
	}

	// BC7 - Various BC7 tables/helpers
	const uint32_t g_bc7_weights1[2] = { 0, 64 };
	const uint32_t g_bc7_weights2[4] = { 0, 21, 43, 64 };
	const uint32_t g_bc7_weights3[8] = { 0, 9, 18, 27, 37, 46, 55, 64 };
	const uint32_t g_bc7_weights4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
	const uint32_t g_astc_weights4[16] = { 0, 4, 8, 12, 17, 21, 25, 29, 35, 39, 43, 47, 52, 56, 60, 64 };
	const uint32_t g_astc_weights5[32] = { 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64 };
	const uint32_t g_astc_weights_3levels[3] = { 0, 32, 64 };

	const uint8_t g_bc7_partition1[16] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };

	const uint8_t g_bc7_partition2[64 * 16] =
	{
		0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,		0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1,		0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,		0,0,0,1,0,0,1,1,0,0,1,1,0,1,1,1,		0,0,0,0,0,0,0,1,0,0,0,1,0,0,1,1,		0,0,1,1,0,1,1,1,0,1,1,1,1,1,1,1,		0,0,0,1,0,0,1,1,0,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,1,0,0,1,1,0,1,1,1,
		0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,1,		0,0,1,1,0,1,1,1,1,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,		0,0,0,1,0,1,1,1,1,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,		0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,		0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,
		0,0,0,0,1,0,0,0,1,1,1,0,1,1,1,1,		0,1,1,1,0,0,0,1,0,0,0,0,0,0,0,0,		0,0,0,0,0,0,0,0,1,0,0,0,1,1,1,0,		0,1,1,1,0,0,1,1,0,0,0,1,0,0,0,0,		0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0,		0,0,0,0,1,0,0,0,1,1,0,0,1,1,1,0,		0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0,		0,1,1,1,0,0,1,1,0,0,1,1,0,0,0,1,
		0,0,1,1,0,0,0,1,0,0,0,1,0,0,0,0,		0,0,0,0,1,0,0,0,1,0,0,0,1,1,0,0,		0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0,		0,0,1,1,0,1,1,0,0,1,1,0,1,1,0,0,		0,0,0,1,0,1,1,1,1,1,1,0,1,0,0,0,		0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,		0,1,1,1,0,0,0,1,1,0,0,0,1,1,1,0,		0,0,1,1,1,0,0,1,1,0,0,1,1,1,0,0,
		0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,		0,0,0,0,1,1,1,1,0,0,0,0,1,1,1,1,		0,1,0,1,1,0,1,0,0,1,0,1,1,0,1,0,		0,0,1,1,0,0,1,1,1,1,0,0,1,1,0,0,		0,0,1,1,1,1,0,0,0,0,1,1,1,1,0,0,		0,1,0,1,0,1,0,1,1,0,1,0,1,0,1,0,		0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,		0,1,0,1,1,0,1,0,1,0,1,0,0,1,0,1,
		0,1,1,1,0,0,1,1,1,1,0,0,1,1,1,0,		0,0,0,1,0,0,1,1,1,1,0,0,1,0,0,0,		0,0,1,1,0,0,1,0,0,1,0,0,1,1,0,0,		0,0,1,1,1,0,1,1,1,1,0,1,1,1,0,0,		0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,		0,0,1,1,1,1,0,0,1,1,0,0,0,0,1,1,		0,1,1,0,0,1,1,0,1,0,0,1,1,0,0,1,		0,0,0,0,0,1,1,0,0,1,1,0,0,0,0,0,
		0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,0,		0,0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,		0,0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,		0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,0,		0,1,1,0,1,1,0,0,1,0,0,1,0,0,1,1,		0,0,1,1,0,1,1,0,1,1,0,0,1,0,0,1,		0,1,1,0,0,0,1,1,1,0,0,1,1,1,0,0,		0,0,1,1,1,0,0,1,1,1,0,0,0,1,1,0,
		0,1,1,0,1,1,0,0,1,1,0,0,1,0,0,1,		0,1,1,0,0,0,1,1,0,0,1,1,1,0,0,1,		0,1,1,1,1,1,1,0,1,0,0,0,0,0,0,1,		0,0,0,1,1,0,0,0,1,1,1,0,0,1,1,1,		0,0,0,0,1,1,1,1,0,0,1,1,0,0,1,1,		0,0,1,1,0,0,1,1,1,1,1,1,0,0,0,0,		0,0,1,0,0,0,1,0,1,1,1,0,1,1,1,0,		0,1,0,0,0,1,0,0,0,1,1,1,0,1,1,1
	};

	const uint8_t g_bc7_partition3[64 * 16] =
	{
		0,0,1,1,0,0,1,1,0,2,2,1,2,2,2,2,		0,0,0,1,0,0,1,1,2,2,1,1,2,2,2,1,		0,0,0,0,2,0,0,1,2,2,1,1,2,2,1,1,		0,2,2,2,0,0,2,2,0,0,1,1,0,1,1,1,		0,0,0,0,0,0,0,0,1,1,2,2,1,1,2,2,		0,0,1,1,0,0,1,1,0,0,2,2,0,0,2,2,		0,0,2,2,0,0,2,2,1,1,1,1,1,1,1,1,		0,0,1,1,0,0,1,1,2,2,1,1,2,2,1,1,
		0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,		0,0,0,0,1,1,1,1,1,1,1,1,2,2,2,2,		0,0,0,0,1,1,1,1,2,2,2,2,2,2,2,2,		0,0,1,2,0,0,1,2,0,0,1,2,0,0,1,2,		0,1,1,2,0,1,1,2,0,1,1,2,0,1,1,2,		0,1,2,2,0,1,2,2,0,1,2,2,0,1,2,2,		0,0,1,1,0,1,1,2,1,1,2,2,1,2,2,2,		0,0,1,1,2,0,0,1,2,2,0,0,2,2,2,0,
		0,0,0,1,0,0,1,1,0,1,1,2,1,1,2,2,		0,1,1,1,0,0,1,1,2,0,0,1,2,2,0,0,		0,0,0,0,1,1,2,2,1,1,2,2,1,1,2,2,		0,0,2,2,0,0,2,2,0,0,2,2,1,1,1,1,		0,1,1,1,0,1,1,1,0,2,2,2,0,2,2,2,		0,0,0,1,0,0,0,1,2,2,2,1,2,2,2,1,		0,0,0,0,0,0,1,1,0,1,2,2,0,1,2,2,		0,0,0,0,1,1,0,0,2,2,1,0,2,2,1,0,
		0,1,2,2,0,1,2,2,0,0,1,1,0,0,0,0,		0,0,1,2,0,0,1,2,1,1,2,2,2,2,2,2,		0,1,1,0,1,2,2,1,1,2,2,1,0,1,1,0,		0,0,0,0,0,1,1,0,1,2,2,1,1,2,2,1,		0,0,2,2,1,1,0,2,1,1,0,2,0,0,2,2,		0,1,1,0,0,1,1,0,2,0,0,2,2,2,2,2,		0,0,1,1,0,1,2,2,0,1,2,2,0,0,1,1,		0,0,0,0,2,0,0,0,2,2,1,1,2,2,2,1,
		0,0,0,0,0,0,0,2,1,1,2,2,1,2,2,2,		0,2,2,2,0,0,2,2,0,0,1,2,0,0,1,1,		0,0,1,1,0,0,1,2,0,0,2,2,0,2,2,2,		0,1,2,0,0,1,2,0,0,1,2,0,0,1,2,0,		0,0,0,0,1,1,1,1,2,2,2,2,0,0,0,0,		0,1,2,0,1,2,0,1,2,0,1,2,0,1,2,0,		0,1,2,0,2,0,1,2,1,2,0,1,0,1,2,0,		0,0,1,1,2,2,0,0,1,1,2,2,0,0,1,1,
		0,0,1,1,1,1,2,2,2,2,0,0,0,0,1,1,		0,1,0,1,0,1,0,1,2,2,2,2,2,2,2,2,		0,0,0,0,0,0,0,0,2,1,2,1,2,1,2,1,		0,0,2,2,1,1,2,2,0,0,2,2,1,1,2,2,		0,0,2,2,0,0,1,1,0,0,2,2,0,0,1,1,		0,2,2,0,1,2,2,1,0,2,2,0,1,2,2,1,		0,1,0,1,2,2,2,2,2,2,2,2,0,1,0,1,		0,0,0,0,2,1,2,1,2,1,2,1,2,1,2,1,
		0,1,0,1,0,1,0,1,0,1,0,1,2,2,2,2,		0,2,2,2,0,1,1,1,0,2,2,2,0,1,1,1,		0,0,0,2,1,1,1,2,0,0,0,2,1,1,1,2,		0,0,0,0,2,1,1,2,2,1,1,2,2,1,1,2,		0,2,2,2,0,1,1,1,0,1,1,1,0,2,2,2,		0,0,0,2,1,1,1,2,1,1,1,2,0,0,0,2,		0,1,1,0,0,1,1,0,0,1,1,0,2,2,2,2,		0,0,0,0,0,0,0,0,2,1,1,2,2,1,1,2,
		0,1,1,0,0,1,1,0,2,2,2,2,2,2,2,2,		0,0,2,2,0,0,1,1,0,0,1,1,0,0,2,2,		0,0,2,2,1,1,2,2,1,1,2,2,0,0,2,2,		0,0,0,0,0,0,0,0,0,0,0,0,2,1,1,2,		0,0,0,2,0,0,0,1,0,0,0,2,0,0,0,1,		0,2,2,2,1,2,2,2,0,2,2,2,1,2,2,2,		0,1,0,1,2,2,2,2,2,2,2,2,2,2,2,2,		0,1,1,1,2,0,1,1,2,2,0,1,2,2,2,0,
	};

	const uint8_t g_bc7_table_anchor_index_second_subset[64] = { 15,15,15,15,15,15,15,15,		15,15,15,15,15,15,15,15,		15, 2, 8, 2, 2, 8, 8,15,		2, 8, 2, 2, 8, 8, 2, 2,		15,15, 6, 8, 2, 8,15,15,		2, 8, 2, 2, 2,15,15, 6,		6, 2, 6, 8,15,15, 2, 2,		15,15,15,15,15, 2, 2,15 };

	const uint8_t g_bc7_table_anchor_index_third_subset_1[64] =
	{
		3, 3,15,15, 8, 3,15,15,		8, 8, 6, 6, 6, 5, 3, 3,		3, 3, 8,15, 3, 3, 6,10,		5, 8, 8, 6, 8, 5,15,15,		8,15, 3, 5, 6,10, 8,15,		15, 3,15, 5,15,15,15,15,		3,15, 5, 5, 5, 8, 5,10,		5,10, 8,13,15,12, 3, 3
	};

	const uint8_t g_bc7_table_anchor_index_third_subset_2[64] =
	{
		15, 8, 8, 3,15,15, 3, 8,		15,15,15,15,15,15,15, 8,		15, 8,15, 3,15, 8,15, 8,		3,15, 6,10,15,15,10, 8,		15, 3,15,10,10, 8, 9,10,		6,15, 8,15, 3, 6, 6, 8,		15, 3,15,15,15,15,15,15,		15,15,15,15, 3,15,15, 8
	};

	const uint8_t g_bc7_num_subsets[8] = { 3, 2, 3, 2, 1, 1, 1, 2 };
	const uint8_t g_bc7_partition_bits[8] = { 4, 6, 6, 6, 0, 0, 0, 6 };
	const uint8_t g_bc7_color_index_bitcount[8] = { 3, 3, 2, 2, 2, 2, 4, 2 };

	const uint8_t g_bc7_mode_has_p_bits[8] = { 1, 1, 0, 1, 0, 0, 1, 1 };
	const uint8_t g_bc7_mode_has_shared_p_bits[8] = { 0, 1, 0, 0, 0, 0, 0, 0 };
	const uint8_t g_bc7_color_precision_table[8] = { 4, 6, 5, 7, 5, 7, 7, 5 };
	const int8_t g_bc7_alpha_precision_table[8] = { 0, 0, 0, 0, 6, 8, 7, 5 };

	const uint8_t g_bc7_alpha_index_bitcount[8] = { 0, 0, 0, 0, 3, 2, 4, 2 }; // note mode 6 has 4 and mode 7 has 2, not really correct as they have a single plane

	endpoint_err g_bc7_mode_6_optimal_endpoints[256][2]; // [c][pbit]
	endpoint_err g_bc7_mode_5_optimal_endpoints[256]; // [c]

	static inline void bc7_set_block_bits(uint8_t* pBytes, uint32_t val, uint32_t num_bits, uint32_t* pCur_ofs)
	{
		assert((num_bits <= 32) && (val < (1ULL << num_bits)));
		while (num_bits)
		{
			const uint32_t n = basisu::minimumu(8 - (*pCur_ofs & 7), num_bits);
			pBytes[*pCur_ofs >> 3] |= (uint8_t)(val << (*pCur_ofs & 7));
			val >>= n;
			num_bits -= n;
			*pCur_ofs += n;
		}
		assert(*pCur_ofs <= 128);
	}

	// TODO: Optimize this.
	void encode_bc7_block(void* pBlock, const bc7_optimization_results* pResults)
	{
		const uint32_t best_mode = pResults->m_mode;

		const uint32_t total_subsets = g_bc7_num_subsets[best_mode];
		const uint32_t total_partitions = 1 << g_bc7_partition_bits[best_mode];
		//const uint32_t num_rotations = 1 << g_bc7_rotation_bits[best_mode];
		//const uint32_t num_index_selectors = (best_mode == 4) ? 2 : 1;

		const uint8_t* pPartition;
		if (total_subsets == 1)
			pPartition = &g_bc7_partition1[0];
		else if (total_subsets == 2)
			pPartition = &g_bc7_partition2[pResults->m_partition * 16];
		else
			pPartition = &g_bc7_partition3[pResults->m_partition * 16];

		uint8_t color_selectors[16];
		memcpy(color_selectors, pResults->m_selectors, 16);

		uint8_t alpha_selectors[16];
		memcpy(alpha_selectors, pResults->m_alpha_selectors, 16);

		color_quad_u8 low[3], high[3];
		memcpy(low, pResults->m_low, sizeof(low));
		memcpy(high, pResults->m_high, sizeof(high));

		uint32_t pbits[3][2];
		memcpy(pbits, pResults->m_pbits, sizeof(pbits));

		int anchor[3] = { -1, -1, -1 };

		for (uint32_t k = 0; k < total_subsets; k++)
		{
			uint32_t anchor_index = 0;
			if (k)
			{
				if ((total_subsets == 3) && (k == 1))
					anchor_index = g_bc7_table_anchor_index_third_subset_1[pResults->m_partition];
				else if ((total_subsets == 3) && (k == 2))
					anchor_index = g_bc7_table_anchor_index_third_subset_2[pResults->m_partition];
				else
					anchor_index = g_bc7_table_anchor_index_second_subset[pResults->m_partition];
			}

			anchor[k] = anchor_index;

			const uint32_t color_index_bits = get_bc7_color_index_size(best_mode, pResults->m_index_selector);
			const uint32_t num_color_indices = 1 << color_index_bits;

			if (color_selectors[anchor_index] & (num_color_indices >> 1))
			{
				for (uint32_t i = 0; i < 16; i++)
					if (pPartition[i] == k)
						color_selectors[i] = (uint8_t)((num_color_indices - 1) - color_selectors[i]);

				if (get_bc7_mode_has_seperate_alpha_selectors(best_mode))
				{
					for (uint32_t q = 0; q < 3; q++)
					{
						uint8_t t = low[k].m_c[q];
						low[k].m_c[q] = high[k].m_c[q];
						high[k].m_c[q] = t;
					}
				}
				else
				{
					color_quad_u8 tmp = low[k];
					low[k] = high[k];
					high[k] = tmp;
				}

				if (!g_bc7_mode_has_shared_p_bits[best_mode])
				{
					uint32_t t = pbits[k][0];
					pbits[k][0] = pbits[k][1];
					pbits[k][1] = t;
				}
			}

			if (get_bc7_mode_has_seperate_alpha_selectors(best_mode))
			{
				const uint32_t alpha_index_bits = get_bc7_alpha_index_size(best_mode, pResults->m_index_selector);
				const uint32_t num_alpha_indices = 1 << alpha_index_bits;

				if (alpha_selectors[anchor_index] & (num_alpha_indices >> 1))
				{
					for (uint32_t i = 0; i < 16; i++)
						if (pPartition[i] == k)
							alpha_selectors[i] = (uint8_t)((num_alpha_indices - 1) - alpha_selectors[i]);

					uint8_t t = low[k].m_c[3];
					low[k].m_c[3] = high[k].m_c[3];
					high[k].m_c[3] = t;
				}
			}
		}

		uint8_t* pBlock_bytes = (uint8_t*)(pBlock);
		memset(pBlock_bytes, 0, BC7ENC_BLOCK_SIZE);

		uint32_t cur_bit_ofs = 0;
		bc7_set_block_bits(pBlock_bytes, 1 << best_mode, best_mode + 1, &cur_bit_ofs);

		if ((best_mode == 4) || (best_mode == 5))
			bc7_set_block_bits(pBlock_bytes, pResults->m_rotation, 2, &cur_bit_ofs);

		if (best_mode == 4)
			bc7_set_block_bits(pBlock_bytes, pResults->m_index_selector, 1, &cur_bit_ofs);

		if (total_partitions > 1)
			bc7_set_block_bits(pBlock_bytes, pResults->m_partition, (total_partitions == 64) ? 6 : 4, &cur_bit_ofs);

		const uint32_t total_comps = (best_mode >= 4) ? 4 : 3;
		for (uint32_t comp = 0; comp < total_comps; comp++)
		{
			for (uint32_t subset = 0; subset < total_subsets; subset++)
			{
				bc7_set_block_bits(pBlock_bytes, low[subset].m_c[comp], (comp == 3) ? g_bc7_alpha_precision_table[best_mode] : g_bc7_color_precision_table[best_mode], &cur_bit_ofs);
				bc7_set_block_bits(pBlock_bytes, high[subset].m_c[comp], (comp == 3) ? g_bc7_alpha_precision_table[best_mode] : g_bc7_color_precision_table[best_mode], &cur_bit_ofs);
			}
		}

		if (g_bc7_mode_has_p_bits[best_mode])
		{
			for (uint32_t subset = 0; subset < total_subsets; subset++)
			{
				bc7_set_block_bits(pBlock_bytes, pbits[subset][0], 1, &cur_bit_ofs);
				if (!g_bc7_mode_has_shared_p_bits[best_mode])
					bc7_set_block_bits(pBlock_bytes, pbits[subset][1], 1, &cur_bit_ofs);
			}
		}

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				int idx = x + y * 4;

				uint32_t n = pResults->m_index_selector ? get_bc7_alpha_index_size(best_mode, pResults->m_index_selector) : get_bc7_color_index_size(best_mode, pResults->m_index_selector);

				if ((idx == anchor[0]) || (idx == anchor[1]) || (idx == anchor[2]))
					n--;

				bc7_set_block_bits(pBlock_bytes, pResults->m_index_selector ? alpha_selectors[idx] : color_selectors[idx], n, &cur_bit_ofs);
			}
		}

		if (get_bc7_mode_has_seperate_alpha_selectors(best_mode))
		{
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					int idx = x + y * 4;

					uint32_t n = pResults->m_index_selector ? get_bc7_color_index_size(best_mode, pResults->m_index_selector) : get_bc7_alpha_index_size(best_mode, pResults->m_index_selector);

					if ((idx == anchor[0]) || (idx == anchor[1]) || (idx == anchor[2]))
						n--;

					bc7_set_block_bits(pBlock_bytes, pResults->m_index_selector ? color_selectors[idx] : alpha_selectors[idx], n, &cur_bit_ofs);
				}
			}
		}

		assert(cur_bit_ofs == 128);
	}

	// ASTC
	static inline void astc_set_bits_1_to_9(uint32_t* pDst, int& bit_offset, uint32_t code, uint32_t codesize)
	{
		uint8_t* pBuf = reinterpret_cast<uint8_t*>(pDst);

		assert(codesize <= 9);
		if (codesize)
		{
			uint32_t byte_bit_offset = bit_offset & 7;
			uint32_t val = code << byte_bit_offset;

			uint32_t index = bit_offset >> 3;
			pBuf[index] |= (uint8_t)val;

			if (codesize > (8 - byte_bit_offset))
				pBuf[index + 1] |= (uint8_t)(val >> 8);

			bit_offset += codesize;
		}
	}

	void pack_astc_solid_block(void* pDst_block, const color32& color)
	{
		uint32_t r = color[0], g = color[1], b = color[2];
		uint32_t a = color[3];

		uint32_t* pOutput = static_cast<uint32_t*>(pDst_block);
		uint8_t* pBytes = reinterpret_cast<uint8_t*>(pDst_block);

		pBytes[0] = 0xfc; pBytes[1] = 0xfd; pBytes[2] = 0xff; pBytes[3] = 0xff;

		pOutput[1] = 0xffffffff;
		pOutput[2] = 0;
		pOutput[3] = 0;

		int bit_pos = 64;
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, r | (r << 8), 16);
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, g | (g << 8), 16);
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, b | (b << 8), 16);
		astc_set_bits(reinterpret_cast<uint32_t*>(pDst_block), bit_pos, a | (a << 8), 16);
	}

	// See 23.21 https://www.khronos.org/registry/DataFormat/specs/1.3/dataformat.1.3.inline.html#_partition_pattern_generation
#ifdef _DEBUG
	static inline uint32_t astc_hash52(uint32_t v)
	{
		uint32_t p = v;
		p ^= p >> 15;	p -= p << 17;	p += p << 7;	p += p << 4;
		p ^= p >> 5;	p += p << 16;	p ^= p >> 7;	p ^= p >> 3;
		p ^= p << 6;	p ^= p >> 17;
		return p;
	}

	int astc_compute_texel_partition(int seed, int x, int y, int z, int partitioncount, bool small_block)
	{
		if (small_block)
		{
			x <<= 1; y <<= 1; z <<= 1;
		}
		seed += (partitioncount - 1) * 1024;
		uint32_t rnum = astc_hash52(seed);
		uint8_t seed1 = rnum & 0xF;
		uint8_t seed2 = (rnum >> 4) & 0xF;
		uint8_t seed3 = (rnum >> 8) & 0xF;
		uint8_t seed4 = (rnum >> 12) & 0xF;
		uint8_t seed5 = (rnum >> 16) & 0xF;
		uint8_t seed6 = (rnum >> 20) & 0xF;
		uint8_t seed7 = (rnum >> 24) & 0xF;
		uint8_t seed8 = (rnum >> 28) & 0xF;
		uint8_t seed9 = (rnum >> 18) & 0xF;
		uint8_t seed10 = (rnum >> 22) & 0xF;
		uint8_t seed11 = (rnum >> 26) & 0xF;
		uint8_t seed12 = ((rnum >> 30) | (rnum << 2)) & 0xF;

		seed1 *= seed1;    seed2 *= seed2;
		seed3 *= seed3;    seed4 *= seed4;
		seed5 *= seed5;    seed6 *= seed6;
		seed7 *= seed7;    seed8 *= seed8;
		seed9 *= seed9;    seed10 *= seed10;
		seed11 *= seed11;   seed12 *= seed12;

		int sh1, sh2, sh3;
		if (seed & 1)
		{
			sh1 = (seed & 2 ? 4 : 5); sh2 = (partitioncount == 3 ? 6 : 5);
		}
		else
		{
			sh1 = (partitioncount == 3 ? 6 : 5); sh2 = (seed & 2 ? 4 : 5);
		}
		sh3 = (seed & 0x10) ? sh1 : sh2;

		seed1 >>= sh1; seed2 >>= sh2; seed3 >>= sh1; seed4 >>= sh2;
		seed5 >>= sh1; seed6 >>= sh2; seed7 >>= sh1; seed8 >>= sh2;
		seed9 >>= sh3; seed10 >>= sh3; seed11 >>= sh3; seed12 >>= sh3;

		int a = seed1 * x + seed2 * y + seed11 * z + (rnum >> 14);
		int b = seed3 * x + seed4 * y + seed12 * z + (rnum >> 10);
		int c = seed5 * x + seed6 * y + seed9 * z + (rnum >> 6);
		int d = seed7 * x + seed8 * y + seed10 * z + (rnum >> 2);

		a &= 0x3F; b &= 0x3F; c &= 0x3F; d &= 0x3F;

		if (partitioncount < 4) d = 0;
		if (partitioncount < 3) c = 0;

		if (a >= b && a >= c && a >= d)
			return 0;
		else if (b >= c && b >= d)
			return 1;
		else if (c >= d)
			return 2;
		else
			return 3;
	}
#endif

	static const uint8_t g_astc_quint_encode[125] =
	{
		0, 1, 2, 3, 4, 8, 9, 10, 11, 12, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28, 5, 13, 21, 29, 6, 32, 33, 34, 35, 36, 40, 41, 42, 43, 44, 48, 49, 50, 51, 52, 56, 57,
		58, 59, 60, 37, 45, 53, 61, 14, 64, 65, 66, 67, 68, 72, 73, 74, 75, 76, 80, 81, 82, 83, 84, 88, 89, 90, 91, 92, 69, 77, 85, 93, 22, 96, 97, 98, 99, 100, 104,
		105, 106, 107, 108, 112, 113, 114, 115, 116, 120, 121, 122, 123, 124, 101, 109, 117, 125, 30, 102, 103, 70, 71, 38, 110, 111, 78, 79, 46, 118, 119, 86, 87, 54,
		126, 127, 94, 95, 62, 39, 47, 55, 63, 31
	};

	// Encodes 3 values to output, usable for any range that uses quints and bits
	static inline void astc_encode_quints(uint32_t* pOutput, const uint8_t* pValues, int& bit_pos, int n)
	{
		// First extract the quints and the bits from the 3 input values
		int quints = 0, bits[3];
		const uint32_t bit_mask = (1 << n) - 1;
		for (int i = 0; i < 3; i++)
		{
			static const int s_muls[3] = { 1, 5, 25 };

			const int t = pValues[i] >> n;

			quints += t * s_muls[i];
			bits[i] = pValues[i] & bit_mask;
		}

		// Encode the quints, by inverting the bit manipulations done by the decoder, converting 3 quints into 7-bits.
		// See https://www.khronos.org/registry/DataFormat/specs/1.2/dataformat.1.2.html#astc-integer-sequence-encoding

		assert(quints < 125);
		const int T = g_astc_quint_encode[quints];

		// Now interleave the 7 encoded quint bits with the bits to form the encoded output. See table 95-96.
		astc_set_bits(pOutput, bit_pos, bits[0] | (astc_extract_bits(T, 0, 2) << n) | (bits[1] << (3 + n)) | (astc_extract_bits(T, 3, 4) << (3 + n * 2)) |
			(bits[2] << (5 + n * 2)) | (astc_extract_bits(T, 5, 6) << (5 + n * 3)), 7 + n * 3);
	}

	// Packs values using ASTC's BISE to output buffer.
	static void astc_pack_bise(uint32_t* pDst, const uint8_t* pSrc_vals, int bit_pos, int num_vals, int range)
	{
		uint32_t temp[5] = { 0, 0, 0, 0, 0 };

		const int num_bits = g_astc_bise_range_table[range][0];

		int group_size = 0;
		if (g_astc_bise_range_table[range][1])
			group_size = 5;
		else if (g_astc_bise_range_table[range][2])
			group_size = 3;

		if (group_size)
		{
			// Range has trits or quints - pack each group of 5 or 3 values 
			const int total_groups = (group_size == 5) ? ((num_vals + 4) / 5) : ((num_vals + 2) / 3);

			for (int group_index = 0; group_index < total_groups; group_index++)
			{
				uint8_t vals[5] = { 0, 0, 0, 0, 0 };

				const int limit = basisu::minimum(group_size, num_vals - group_index * group_size);
				for (int i = 0; i < limit; i++)
					vals[i] = pSrc_vals[group_index * group_size + i];

				if (group_size == 5)
					astc_encode_trits(temp, vals, bit_pos, num_bits);
				else
					astc_encode_quints(temp, vals, bit_pos, num_bits);
			}
		}
		else
		{
			for (int i = 0; i < num_vals; i++)
				astc_set_bits_1_to_9(temp, bit_pos, pSrc_vals[i], num_bits);
		}

		pDst[0] |= temp[0]; pDst[1] |= temp[1];
		pDst[2] |= temp[2]; pDst[3] |= temp[3];
	}

	const uint32_t ASTC_BLOCK_MODE_BITS = 11;
	const uint32_t ASTC_PART_BITS = 2;
	const uint32_t ASTC_CEM_BITS = 4;
	const uint32_t ASTC_PARTITION_INDEX_BITS = 10;
	const uint32_t ASTC_CCS_BITS = 2;

	const uint32_t g_uastc_mode_astc_block_mode[TOTAL_UASTC_MODES] = { 0x242, 0x42, 0x53, 0x42, 0x42, 0x53, 0x442, 0x42, 0, 0x42, 0x242, 0x442, 0x53, 0x441, 0x42, 0x242, 0x42, 0x442, 0x253 };

	bool pack_astc_block(uint32_t* pDst, const astc_block_desc* pBlock, uint32_t uastc_mode)
	{
		assert(uastc_mode < TOTAL_UASTC_MODES);
		uint8_t* pDst_bytes = reinterpret_cast<uint8_t*>(pDst);

		const int total_weights = pBlock->m_dual_plane ? 32 : 16;

		// Set mode bits - see Table 146-147
		uint32_t mode = g_uastc_mode_astc_block_mode[uastc_mode];
		pDst_bytes[0] = (uint8_t)mode;
		pDst_bytes[1] = (uint8_t)(mode >> 8);

		memset(pDst_bytes + 2, 0, 16 - 2);

		int bit_pos = ASTC_BLOCK_MODE_BITS;

		// We only support 1-5 bit weight indices
		assert(!g_astc_bise_range_table[pBlock->m_weight_range][1] && !g_astc_bise_range_table[pBlock->m_weight_range][2]);
		const int bits_per_weight = g_astc_bise_range_table[pBlock->m_weight_range][0];

		// See table 143 - PART
		astc_set_bits_1_to_9(pDst, bit_pos, pBlock->m_subsets - 1, ASTC_PART_BITS);

		if (pBlock->m_subsets == 1)
			astc_set_bits_1_to_9(pDst, bit_pos, pBlock->m_cem, ASTC_CEM_BITS);
		else
		{
			// See table 145
			astc_set_bits(pDst, bit_pos, pBlock->m_partition_seed, ASTC_PARTITION_INDEX_BITS);

			// Table 150 - we assume all CEM's are equal, so write 2 0's along with the CEM
			astc_set_bits_1_to_9(pDst, bit_pos, (pBlock->m_cem << 2) & 63, ASTC_CEM_BITS + 2);
		}

		if (pBlock->m_dual_plane)
		{
			const int total_weight_bits = total_weights * bits_per_weight;

			// See Illegal Encodings 23.24
			// https://www.khronos.org/registry/DataFormat/specs/1.3/dataformat.1.3.inline.html#_illegal_encodings
			assert((total_weight_bits >= 24) && (total_weight_bits <= 96));

			int ccs_bit_pos = 128 - total_weight_bits - ASTC_CCS_BITS;
			astc_set_bits_1_to_9(pDst, ccs_bit_pos, pBlock->m_ccs, ASTC_CCS_BITS);
		}

		const int num_cem_pairs = (1 + (pBlock->m_cem >> 2)) * pBlock->m_subsets;
		assert(num_cem_pairs <= 9);

		astc_pack_bise(pDst, pBlock->m_endpoints, bit_pos, num_cem_pairs * 2, g_uastc_mode_endpoint_ranges[uastc_mode]);

		// Write the weight bits in reverse bit order.
		switch (bits_per_weight)
		{
		case 1:
		{
			const uint32_t N = 1;
			for (int i = 0; i < total_weights; i++)
			{
				const uint32_t ofs = 128 - N - i;
				assert((ofs >> 3) < 16);
				pDst_bytes[ofs >> 3] |= (pBlock->m_weights[i] << (ofs & 7));
			}
			break;
		}
		case 2:
		{
			const uint32_t N = 2;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits2[4] = { 0, 2, 1, 3 };
				const uint32_t ofs = 128 - N - (i * N);
				assert((ofs >> 3) < 16);
				pDst_bytes[ofs >> 3] |= (s_reverse_bits2[pBlock->m_weights[i]] << (ofs & 7));
			}
			break;
		}
		case 3:
		{
			const uint32_t N = 3;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits3[8] = { 0, 4, 2, 6, 1, 5, 3, 7 };

				const uint32_t ofs = 128 - N - (i * N);
				const uint32_t rev = s_reverse_bits3[pBlock->m_weights[i]] << (ofs & 7);

				uint32_t index = ofs >> 3;
				assert(index < 16);
				pDst_bytes[index++] |= rev & 0xFF;
				if (index < 16)
					pDst_bytes[index++] |= (rev >> 8);
			}
			break;
		}
		case 4:
		{
			const uint32_t N = 4;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits4[16] = { 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 };
				const int ofs = 128 - N - (i * N);
				assert(ofs >= 0 && (ofs >> 3) < 16);
				pDst_bytes[ofs >> 3] |= (s_reverse_bits4[pBlock->m_weights[i]] << (ofs & 7));
			}
			break;
		}
		case 5:
		{
			const uint32_t N = 5;
			for (int i = 0; i < total_weights; i++)
			{
				static const uint8_t s_reverse_bits5[32] = { 0, 16, 8, 24, 4, 20, 12, 28, 2, 18, 10, 26, 6, 22, 14, 30, 1, 17, 9, 25, 5, 21, 13, 29, 3, 19, 11, 27, 7, 23, 15, 31 };

				const uint32_t ofs = 128 - N - (i * N);
				const uint32_t rev = s_reverse_bits5[pBlock->m_weights[i]] << (ofs & 7);

				uint32_t index = ofs >> 3;
				assert(index < 16);
				pDst_bytes[index++] |= rev & 0xFF;
				if (index < 16)
					pDst_bytes[index++] |= (rev >> 8);
			}

			break;
		}
		default:
			assert(0);
			break;
		}

		return true;
	}

	const uint8_t* get_anchor_indices(uint32_t subsets, uint32_t mode, uint32_t common_pattern, const uint8_t*& pPartition_pattern)
	{
		const uint8_t* pSubset_anchor_indices = g_zero_pattern;
		pPartition_pattern = g_zero_pattern;

		if (subsets >= 2)
		{
			if (subsets == 3)
			{
				pPartition_pattern = &g_astc_bc7_patterns3[common_pattern][0];
				pSubset_anchor_indices = &g_astc_bc7_pattern3_anchors[common_pattern][0];
			}
			else if (mode == 7)
			{
				pPartition_pattern = &g_bc7_3_astc2_patterns2[common_pattern][0];
				pSubset_anchor_indices = &g_bc7_3_astc2_patterns2_anchors[common_pattern][0];
			}
			else
			{
				pPartition_pattern = &g_astc_bc7_patterns2[common_pattern][0];
				pSubset_anchor_indices = &g_astc_bc7_pattern2_anchors[common_pattern][0];
			}
		}

		return pSubset_anchor_indices;
	}

	static inline uint32_t read_bit(const uint8_t* pBuf, uint32_t& bit_offset)
	{
		uint32_t byte_bits = pBuf[bit_offset >> 3] >> (bit_offset & 7);
		bit_offset += 1;
		return byte_bits & 1;
	}

	static inline uint32_t read_bits1_to_9(const uint8_t* pBuf, uint32_t& bit_offset, uint32_t codesize)
	{
		assert(codesize <= 9);
		if (!codesize)
			return 0;

		if ((BASISD_IS_BIG_ENDIAN) || (!BASISD_USE_UNALIGNED_WORD_READS) || (bit_offset >= 112))
		{
			const uint8_t* pBytes = &pBuf[bit_offset >> 3U];

			uint32_t byte_bit_offset = bit_offset & 7U;

			uint32_t bits = pBytes[0] >> byte_bit_offset;
			uint32_t bits_read = basisu::minimum<int>(codesize, 8 - byte_bit_offset);

			uint32_t bits_remaining = codesize - bits_read;
			if (bits_remaining)
				bits |= ((uint32_t)pBytes[1]) << bits_read;

			bit_offset += codesize;

			return bits & ((1U << codesize) - 1U);
		}

		uint32_t byte_bit_offset = bit_offset & 7U;
		const uint16_t w = *(const uint16_t *)(&pBuf[bit_offset >> 3U]);
		bit_offset += codesize;
		return (w >> byte_bit_offset) & ((1U << codesize) - 1U);
	}

	inline uint64_t read_bits64(const uint8_t* pBuf, uint32_t& bit_offset, uint32_t codesize)
	{
		assert(codesize <= 64U);
		uint64_t bits = 0;
		uint32_t total_bits = 0;

		while (total_bits < codesize)
		{
			uint32_t byte_bit_offset = bit_offset & 7U;
			uint32_t bits_to_read = basisu::minimum<int>(codesize - total_bits, 8U - byte_bit_offset);

			uint32_t byte_bits = pBuf[bit_offset >> 3U] >> byte_bit_offset;
			byte_bits &= ((1U << bits_to_read) - 1U);

			bits |= ((uint64_t)(byte_bits) << total_bits);

			total_bits += bits_to_read;
			bit_offset += bits_to_read;
		}

		return bits;
	}

	static inline uint32_t read_bits1_to_9_fst(const uint8_t* pBuf, uint32_t& bit_offset, uint32_t codesize)
	{
		assert(codesize <= 9);
		if (!codesize)
			return 0;
		assert(bit_offset < 112);

		if ((BASISD_IS_BIG_ENDIAN) || (!BASISD_USE_UNALIGNED_WORD_READS))
		{
			const uint8_t* pBytes = &pBuf[bit_offset >> 3U];

			uint32_t byte_bit_offset = bit_offset & 7U;

			uint32_t bits = pBytes[0] >> byte_bit_offset;
			uint32_t bits_read = basisu::minimum<int>(codesize, 8 - byte_bit_offset);

			uint32_t bits_remaining = codesize - bits_read;
			if (bits_remaining)
				bits |= ((uint32_t)pBytes[1]) << bits_read;

			bit_offset += codesize;

			return bits & ((1U << codesize) - 1U);
		}
		else
		{
			uint32_t byte_bit_offset = bit_offset & 7U;
			const uint16_t w = *(const uint16_t*)(&pBuf[bit_offset >> 3U]);
			bit_offset += codesize;
			return (w >> byte_bit_offset) & ((1U << codesize) - 1U);
		}
	}

	bool unpack_uastc(const uastc_block& blk, unpacked_uastc_block& unpacked, bool blue_contract_check, bool read_hints)
	{
		//memset(&unpacked, 0, sizeof(unpacked));
				
#if 0
		uint8_t table[128];
		memset(table, 0xFF, sizeof(table));

		{
			for (uint32_t mode = 0; mode <= TOTAL_UASTC_MODES; mode++)
			{
				const uint32_t code = g_uastc_mode_huff_codes[mode][0];
				const uint32_t codesize = g_uastc_mode_huff_codes[mode][1];

				table[code] = mode;

				uint32_t bits_left = 7 - codesize;
				for (uint32_t i = 0; i < (1 << bits_left); i++)
					table[code | (i << codesize)] = mode;
			}

			for (uint32_t i = 0; i < 128; i++)
				printf("%u,", table[i]);
			exit(0);
		}
#endif

		const int mode = g_uastc_huff_modes[blk.m_bytes[0] & 127];
		if (mode >= (int)TOTAL_UASTC_MODES)
			return false;

		unpacked.m_mode = mode;
		unpacked.m_common_pattern = 0;

		uint32_t bit_ofs = g_uastc_mode_huff_codes[mode][1];

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			unpacked.m_solid_color.r = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
			unpacked.m_solid_color.g = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
			unpacked.m_solid_color.b = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
			unpacked.m_solid_color.a = (uint8_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);

			if (read_hints)
			{
				unpacked.m_etc1_flip = false;
				unpacked.m_etc1_diff = read_bit(blk.m_bytes, bit_ofs) != 0;
				unpacked.m_etc1_inten0 = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 3);
				unpacked.m_etc1_inten1 = 0;
				unpacked.m_etc1_selector = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 2);
				unpacked.m_etc1_r = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
				unpacked.m_etc1_g = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
				unpacked.m_etc1_b = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
				unpacked.m_etc1_bias = 0;
				unpacked.m_etc2_hints = 0;
			}

			return true;
		}
				
		if (read_hints)
		{
			if (g_uastc_mode_has_bc1_hint0[mode])
				unpacked.m_bc1_hint0 = read_bit(blk.m_bytes, bit_ofs) != 0;
			else
				unpacked.m_bc1_hint0 = false;

			if (g_uastc_mode_has_bc1_hint1[mode])
				unpacked.m_bc1_hint1 = read_bit(blk.m_bytes, bit_ofs) != 0;
			else
				unpacked.m_bc1_hint1 = false;

			unpacked.m_etc1_flip = read_bit(blk.m_bytes, bit_ofs) != 0;
			unpacked.m_etc1_diff = read_bit(blk.m_bytes, bit_ofs) != 0;
			unpacked.m_etc1_inten0 = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 3);
			unpacked.m_etc1_inten1 = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 3);

			if (g_uastc_mode_has_etc1_bias[mode])
				unpacked.m_etc1_bias = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
			else
				unpacked.m_etc1_bias = 0;

			if (g_uastc_mode_has_alpha[mode])
			{
				unpacked.m_etc2_hints = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 8);
				//assert(unpacked.m_etc2_hints > 0);
			}
			else
				unpacked.m_etc2_hints = 0;
		}
		else
			bit_ofs += g_uastc_mode_total_hint_bits[mode];
				
		uint32_t subsets = 1;
		switch (mode)
		{
		case 2:
		case 4:
		case 7:
		case 9:
		case 16:
			unpacked.m_common_pattern = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 5);
			subsets = 2;
			break;
		case 3:
			unpacked.m_common_pattern = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 4);
			subsets = 3;
			break;
		default:
			break;
		}

		uint32_t part_seed = 0;
		switch (mode)
		{
		case 2:
		case 4:
		case 9:
		case 16:
			if (unpacked.m_common_pattern >= TOTAL_ASTC_BC7_COMMON_PARTITIONS2)
				return false;

			part_seed = g_astc_bc7_common_partitions2[unpacked.m_common_pattern].m_astc;
			break;
		case 3:
			if (unpacked.m_common_pattern >= TOTAL_ASTC_BC7_COMMON_PARTITIONS3)
				return false;

			part_seed = g_astc_bc7_common_partitions3[unpacked.m_common_pattern].m_astc;
			break;
		case 7:
			if (unpacked.m_common_pattern >= TOTAL_BC7_3_ASTC2_COMMON_PARTITIONS)
				return false;

			part_seed = g_bc7_3_astc2_common_partitions[unpacked.m_common_pattern].m_astc2;
			break;
		default:
			break;
		}

		uint32_t total_planes = 1;
		switch (mode)
		{
		case 6:
		case 11:
		case 13:
			unpacked.m_astc.m_ccs = (int)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, 2);
			total_planes = 2;
			break;
		case 17:
			unpacked.m_astc.m_ccs = 3;
			total_planes = 2;
			break;
		default:
			break;
		}

		unpacked.m_astc.m_dual_plane = (total_planes == 2);

		unpacked.m_astc.m_subsets = subsets;
		unpacked.m_astc.m_partition_seed = part_seed;

		const uint32_t total_comps = g_uastc_mode_comps[mode];

		const uint32_t weight_bits = g_uastc_mode_weight_bits[mode];

		unpacked.m_astc.m_weight_range = g_uastc_mode_weight_ranges[mode];

		const uint32_t total_values = total_comps * 2 * subsets;
		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];

		const uint32_t cem = g_uastc_mode_cem[mode];
		unpacked.m_astc.m_cem = cem;

		const uint32_t ep_bits = g_astc_bise_range_table[endpoint_range][0];
		const uint32_t ep_trits = g_astc_bise_range_table[endpoint_range][1];
		const uint32_t ep_quints = g_astc_bise_range_table[endpoint_range][2];

		uint32_t total_tqs = 0;
		uint32_t bundle_size = 0, mul = 0;
		if (ep_trits)
		{
			total_tqs = (total_values + 4) / 5;
			bundle_size = 5;
			mul = 3;
		}
		else if (ep_quints)
		{
			total_tqs = (total_values + 2) / 3;
			bundle_size = 3;
			mul = 5;
		}

		uint32_t tq_values[8];
		for (uint32_t i = 0; i < total_tqs; i++)
		{
			uint32_t num_bits = ep_trits ? 8 : 7;
			if (i == (total_tqs - 1))
			{
				uint32_t num_remaining = total_values - (total_tqs - 1) * bundle_size;
				if (ep_trits)
				{
					switch (num_remaining)
					{
					case 1: num_bits = 2; break;
					case 2: num_bits = 4; break;
					case 3: num_bits = 5; break;
					case 4: num_bits = 7; break;
					default: break;
					}
				}
				else if (ep_quints)
				{
					switch (num_remaining)
					{
					case 1: num_bits = 3; break;
					case 2: num_bits = 5; break;
					default: break;
					}
				}
			}

			tq_values[i] = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, num_bits);
		} // i

		uint32_t accum = 0;
		uint32_t accum_remaining = 0;
		uint32_t next_tq_index = 0;

		for (uint32_t i = 0; i < total_values; i++)
		{
			uint32_t value = (uint32_t)read_bits1_to_9_fst(blk.m_bytes, bit_ofs, ep_bits);

			if (total_tqs)
			{
				if (!accum_remaining)
				{
					assert(next_tq_index < total_tqs);
					accum = tq_values[next_tq_index++];
					accum_remaining = bundle_size;
				}

				// TODO: Optimize with tables
				uint32_t v = accum % mul;
				accum /= mul;
				accum_remaining--;

				value |= (v << ep_bits);
			}

			unpacked.m_astc.m_endpoints[i] = (uint8_t)value;
		}

		const uint8_t* pPartition_pattern;
		const uint8_t* pSubset_anchor_indices = get_anchor_indices(subsets, mode, unpacked.m_common_pattern, pPartition_pattern);

#ifdef _DEBUG
		for (uint32_t i = 0; i < 16; i++)
			assert(pPartition_pattern[i] == astc_compute_texel_partition(part_seed, i & 3, i >> 2, 0, subsets, true));

		for (uint32_t subset_index = 0; subset_index < subsets; subset_index++)
		{
			uint32_t anchor_index = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				if (pPartition_pattern[i] == subset_index)
				{
					anchor_index = i;
					break;
				}
			}

			assert(pSubset_anchor_indices[subset_index] == anchor_index);
		}
#endif

#if 0
		const uint32_t total_planes_shift = total_planes - 1;
		for (uint32_t i = 0; i < 16 * total_planes; i++)
		{
			uint32_t num_bits = weight_bits;
			for (uint32_t s = 0; s < subsets; s++)
			{
				if (pSubset_anchor_indices[s] == (i >> total_planes_shift))
				{
					num_bits--;
					break;
				}
			}

			unpacked.m_astc.m_weights[i] = (uint8_t)read_bits1_to_9(blk.m_bytes, bit_ofs, num_bits);
		}
#endif

		if (mode == 18)
		{
			// Mode 18 is the only mode with more than 64 weight bits.
			for (uint32_t i = 0; i < 16; i++)
				unpacked.m_astc.m_weights[i] = (uint8_t)read_bits1_to_9(blk.m_bytes, bit_ofs, i ? weight_bits : (weight_bits - 1));
		}
		else
		{
			// All other modes have <= 64 weight bits.
			uint64_t bits;
			
			// Read the weight bits
			if ((BASISD_IS_BIG_ENDIAN) || (!BASISD_USE_UNALIGNED_WORD_READS))
				bits = read_bits64(blk.m_bytes, bit_ofs, basisu::minimum<int>(64, 128 - (int)bit_ofs));
			else
			{
				bits = blk.m_dwords[2];
				bits |= (((uint64_t)blk.m_dwords[3]) << 32U);
				
				if (bit_ofs >= 64U)
					bits >>= (bit_ofs - 64U);
				else
				{
					assert(bit_ofs >= 56U);
					
					uint32_t bits_needed = 64U - bit_ofs;
					bits <<= bits_needed;
					bits |= (blk.m_bytes[7] >> (8U - bits_needed));
				}
			}
						
			bit_ofs = 0;

			const uint32_t mask = (1U << weight_bits) - 1U;
			const uint32_t anchor_mask = (1U << (weight_bits - 1U)) - 1U;
			
			if (total_planes == 2)
			{
				// Dual plane modes always have a single subset, and the first 2 weights are anchors.

				unpacked.m_astc.m_weights[0] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
				bit_ofs += (weight_bits - 1);
				
				unpacked.m_astc.m_weights[1] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
				bit_ofs += (weight_bits - 1);

				for (uint32_t i = 2; i < 32; i++)
				{
					unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & mask);
					bit_ofs += weight_bits;
				}
			}
			else
			{
				if (subsets == 1)
				{
					// Specialize the single subset case.
					if (weight_bits == 4)
					{
						assert(bit_ofs == 0);
						
						// Specialize the most common case: 4-bit weights.
						unpacked.m_astc.m_weights[0] = (uint8_t)((uint32_t)(bits) & 7);
						unpacked.m_astc.m_weights[1] = (uint8_t)((uint32_t)(bits >> 3) & 15);
						unpacked.m_astc.m_weights[2] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 1)) & 15);
						unpacked.m_astc.m_weights[3] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 2)) & 15);

						unpacked.m_astc.m_weights[4] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 3)) & 15);
						unpacked.m_astc.m_weights[5] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 4)) & 15);
						unpacked.m_astc.m_weights[6] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 5)) & 15);
						unpacked.m_astc.m_weights[7] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 6)) & 15);

						unpacked.m_astc.m_weights[8] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 7)) & 15);
						unpacked.m_astc.m_weights[9] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 8)) & 15);
						unpacked.m_astc.m_weights[10] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 9)) & 15);
						unpacked.m_astc.m_weights[11] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 10)) & 15);

						unpacked.m_astc.m_weights[12] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 11)) & 15);
						unpacked.m_astc.m_weights[13] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 12)) & 15);
						unpacked.m_astc.m_weights[14] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 13)) & 15);
						unpacked.m_astc.m_weights[15] = (uint8_t)((uint32_t)(bits >> (3 + 4 * 14)) & 15);
					}
					else
					{
						// First weight is always an anchor.
						unpacked.m_astc.m_weights[0] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
						bit_ofs += (weight_bits - 1);

						for (uint32_t i = 1; i < 16; i++)
						{
							unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & mask);
							bit_ofs += weight_bits;
						}
					}
				}
				else
				{
					const uint32_t a0 = pSubset_anchor_indices[0], a1 = pSubset_anchor_indices[1], a2 = pSubset_anchor_indices[2];

					for (uint32_t i = 0; i < 16; i++)
					{
						if ((i == a0) || (i == a1) || (i == a2))
						{
							unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & anchor_mask);
							bit_ofs += (weight_bits - 1);
						}
						else
						{
							unpacked.m_astc.m_weights[i] = (uint8_t)((uint32_t)(bits >> bit_ofs) & mask);
							bit_ofs += weight_bits;
						}
					}
				}
			}
		}

		if ((blue_contract_check) && (total_comps >= 3))
		{
			// We only need to disable ASTC Blue Contraction when we'll be packing to ASTC. The other transcoders don't care.
			bool invert_subset[3] = { false, false, false };
			bool any_flag = false;

			for (uint32_t subset_index = 0; subset_index < subsets; subset_index++)
			{
				const int s0 = g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 0]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 2]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 4]].m_unquant;

				const int s1 = g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 1]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 3]].m_unquant +
					g_astc_unquant[endpoint_range][unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + 5]].m_unquant;

				if (s1 < s0)
				{
					for (uint32_t c = 0; c < total_comps; c++)
						std::swap(unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + c * 2 + 0], unpacked.m_astc.m_endpoints[subset_index * total_comps * 2 + c * 2 + 1]);

					invert_subset[subset_index] = true;
					any_flag = true;
				}
			}

			if (any_flag)
			{
				const uint32_t weight_mask = (1 << weight_bits) - 1;

				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t subset = pPartition_pattern[i];

					if (invert_subset[subset])
					{
						unpacked.m_astc.m_weights[i * total_planes] = (uint8_t)(weight_mask - unpacked.m_astc.m_weights[i * total_planes]);

						if (total_planes == 2)
							unpacked.m_astc.m_weights[i * total_planes + 1] = (uint8_t)(weight_mask - unpacked.m_astc.m_weights[i * total_planes + 1]);
					}
				}
			}
		}

		return true;
	}

	static const uint32_t* g_astc_weight_tables[6] = { nullptr, g_bc7_weights1, g_bc7_weights2, g_bc7_weights3, g_astc_weights4, g_astc_weights5 };

	bool unpack_uastc(uint32_t mode, uint32_t common_pattern, const color32& solid_color, const astc_block_desc& astc, color32* pPixels, bool srgb)
	{
		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			for (uint32_t i = 0; i < 16; i++)
				pPixels[i] = solid_color;
			return true;
		}

		color32 endpoints[3][2];

		const uint32_t total_subsets = g_uastc_mode_subsets[mode];
		const uint32_t total_comps = basisu::minimum<uint32_t>(4U, g_uastc_mode_comps[mode]);
		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];
		const uint32_t total_planes = g_uastc_mode_planes[mode];
		const uint32_t weight_bits = g_uastc_mode_weight_bits[mode];
		const uint32_t weight_levels = 1 << weight_bits;

		for (uint32_t subset_index = 0; subset_index < total_subsets; subset_index++)
		{
			if (total_comps == 2)
			{
				const uint32_t ll = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 0 * 2 + 0]].m_unquant;
				const uint32_t lh = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 0 * 2 + 1]].m_unquant;

				const uint32_t al = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 1 * 2 + 0]].m_unquant;
				const uint32_t ah = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + 1 * 2 + 1]].m_unquant;

				endpoints[subset_index][0].set_noclamp_rgba(ll, ll, ll, al);
				endpoints[subset_index][1].set_noclamp_rgba(lh, lh, lh, ah);
			}
			else
			{
				for (uint32_t comp_index = 0; comp_index < total_comps; comp_index++)
				{
					endpoints[subset_index][0][comp_index] = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + comp_index * 2 + 0]].m_unquant;
					endpoints[subset_index][1][comp_index] = g_astc_unquant[endpoint_range][astc.m_endpoints[subset_index * total_comps * 2 + comp_index * 2 + 1]].m_unquant;
				}
				for (uint32_t comp_index = total_comps; comp_index < 4; comp_index++)
				{
					endpoints[subset_index][0][comp_index] = 255;
					endpoints[subset_index][1][comp_index] = 255;
				}
			}
		}

		color32 block_colors[3][32];

		const uint32_t* pWeights = g_astc_weight_tables[weight_bits];

		for (uint32_t subset_index = 0; subset_index < total_subsets; subset_index++)
		{
			for (uint32_t l = 0; l < weight_levels; l++)
			{
				if (total_comps == 2)
				{
					const uint8_t lc = (uint8_t)astc_interpolate(endpoints[subset_index][0][0], endpoints[subset_index][1][0], pWeights[l], srgb);
					const uint8_t ac = (uint8_t)astc_interpolate(endpoints[subset_index][0][3], endpoints[subset_index][1][3], pWeights[l], srgb);

					block_colors[subset_index][l].set(lc, lc, lc, ac);
				}
				else
				{
					uint32_t comp_index;
					for (comp_index = 0; comp_index < total_comps; comp_index++)
						block_colors[subset_index][l][comp_index] = (uint8_t)astc_interpolate(endpoints[subset_index][0][comp_index], endpoints[subset_index][1][comp_index], pWeights[l], srgb);

					for (; comp_index < 4; comp_index++)
						block_colors[subset_index][l][comp_index] = 255;
				}
			}
		}

		const uint8_t* pPartition_pattern = g_zero_pattern;

		if (total_subsets >= 2)
		{
			if (total_subsets == 3)
				pPartition_pattern = &g_astc_bc7_patterns3[common_pattern][0];
			else if (mode == 7)
				pPartition_pattern = &g_bc7_3_astc2_patterns2[common_pattern][0];
			else
				pPartition_pattern = &g_astc_bc7_patterns2[common_pattern][0];

#ifdef _DEBUG
			for (uint32_t i = 0; i < 16; i++)
			{
				assert(pPartition_pattern[i] == (uint8_t)astc_compute_texel_partition(astc.m_partition_seed, i & 3, i >> 2, 0, total_subsets, true));
			}
#endif
		}

		if (total_planes == 1)
		{
			if (total_subsets == 1)
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					assert(astc.m_weights[i] < weight_levels);
					pPixels[i] = block_colors[0][astc.m_weights[i]];
				}
			}
			else
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					assert(astc.m_weights[i] < weight_levels);
					pPixels[i] = block_colors[pPartition_pattern[i]][astc.m_weights[i]];
				}
			}
		}
		else
		{
			assert(total_subsets == 1);

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = 0; // pPartition_pattern[i];

				const uint32_t weight_index0 = astc.m_weights[i * 2];
				const uint32_t weight_index1 = astc.m_weights[i * 2 + 1];

				assert(weight_index0 < weight_levels && weight_index1 < weight_levels);

				color32& c = pPixels[i];
				for (uint32_t comp = 0; comp < 4; comp++)
				{
					if ((int)comp == astc.m_ccs)
						c[comp] = block_colors[subset_index][weight_index1][comp];
					else
						c[comp] = block_colors[subset_index][weight_index0][comp];
				}
			}
		}

		return true;
	}

	bool unpack_uastc(const unpacked_uastc_block& unpacked_blk, color32* pPixels, bool srgb)
	{
		return unpack_uastc(unpacked_blk.m_mode, unpacked_blk.m_common_pattern, unpacked_blk.m_solid_color, unpacked_blk.m_astc, pPixels, srgb);
	}

	bool unpack_uastc(const uastc_block& blk, color32* pPixels, bool srgb)
	{
		unpacked_uastc_block unpacked_blk;

		if (!unpack_uastc(blk, unpacked_blk, false, false))
			return false;

		return unpack_uastc(unpacked_blk, pPixels, srgb);
	}

	// Determines the best shared pbit to use to encode xl/xh
	static void determine_shared_pbits(
		uint32_t total_comps, uint32_t comp_bits, float xl[4], float xh[4],
		color_quad_u8& bestMinColor, color_quad_u8& bestMaxColor, uint32_t best_pbits[2])
	{
		const uint32_t total_bits = comp_bits + 1;
		assert(total_bits >= 4 && total_bits <= 8);

		const int iscalep = (1 << total_bits) - 1;
		const float scalep = (float)iscalep;

		float best_err = 1e+9f;

		for (int p = 0; p < 2; p++)
		{
			color_quad_u8 xMinColor, xMaxColor;
			for (uint32_t c = 0; c < 4; c++)
			{
				xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
				xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
			}

			color_quad_u8 scaledLow, scaledHigh;

			for (uint32_t i = 0; i < 4; i++)
			{
				scaledLow.m_c[i] = (xMinColor.m_c[i] << (8 - total_bits));
				scaledLow.m_c[i] |= (scaledLow.m_c[i] >> total_bits);
				assert(scaledLow.m_c[i] <= 255);

				scaledHigh.m_c[i] = (xMaxColor.m_c[i] << (8 - total_bits));
				scaledHigh.m_c[i] |= (scaledHigh.m_c[i] >> total_bits);
				assert(scaledHigh.m_c[i] <= 255);
			}

			float err = 0;
			for (uint32_t i = 0; i < total_comps; i++)
				err += basisu::squaref((scaledLow.m_c[i] / 255.0f) - xl[i]) + basisu::squaref((scaledHigh.m_c[i] / 255.0f) - xh[i]);

			if (err < best_err)
			{
				best_err = err;
				best_pbits[0] = p;
				best_pbits[1] = p;
				for (uint32_t j = 0; j < 4; j++)
				{
					bestMinColor.m_c[j] = xMinColor.m_c[j] >> 1;
					bestMaxColor.m_c[j] = xMaxColor.m_c[j] >> 1;
				}
			}
		}
	}

	// Determines the best unique pbits to use to encode xl/xh
	static void determine_unique_pbits(
		uint32_t total_comps, uint32_t comp_bits, float xl[4], float xh[4],
		color_quad_u8& bestMinColor, color_quad_u8& bestMaxColor, uint32_t best_pbits[2])
	{
		const uint32_t total_bits = comp_bits + 1;
		const int iscalep = (1 << total_bits) - 1;
		const float scalep = (float)iscalep;

		float best_err0 = 1e+9f;
		float best_err1 = 1e+9f;

		for (int p = 0; p < 2; p++)
		{
			color_quad_u8 xMinColor, xMaxColor;

			for (uint32_t c = 0; c < 4; c++)
			{
				xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
				xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p));
			}

			color_quad_u8 scaledLow, scaledHigh;
			for (uint32_t i = 0; i < 4; i++)
			{
				scaledLow.m_c[i] = (xMinColor.m_c[i] << (8 - total_bits));
				scaledLow.m_c[i] |= (scaledLow.m_c[i] >> total_bits);
				assert(scaledLow.m_c[i] <= 255);

				scaledHigh.m_c[i] = (xMaxColor.m_c[i] << (8 - total_bits));
				scaledHigh.m_c[i] |= (scaledHigh.m_c[i] >> total_bits);
				assert(scaledHigh.m_c[i] <= 255);
			}

			float err0 = 0, err1 = 0;
			for (uint32_t i = 0; i < total_comps; i++)
			{
				err0 += basisu::squaref(scaledLow.m_c[i] - xl[i] * 255.0f);
				err1 += basisu::squaref(scaledHigh.m_c[i] - xh[i] * 255.0f);
			}

			if (err0 < best_err0)
			{
				best_err0 = err0;
				best_pbits[0] = p;

				bestMinColor.m_c[0] = xMinColor.m_c[0] >> 1;
				bestMinColor.m_c[1] = xMinColor.m_c[1] >> 1;
				bestMinColor.m_c[2] = xMinColor.m_c[2] >> 1;
				bestMinColor.m_c[3] = xMinColor.m_c[3] >> 1;
			}

			if (err1 < best_err1)
			{
				best_err1 = err1;
				best_pbits[1] = p;

				bestMaxColor.m_c[0] = xMaxColor.m_c[0] >> 1;
				bestMaxColor.m_c[1] = xMaxColor.m_c[1] >> 1;
				bestMaxColor.m_c[2] = xMaxColor.m_c[2] >> 1;
				bestMaxColor.m_c[3] = xMaxColor.m_c[3] >> 1;
			}
		}
	}

	bool transcode_uastc_to_astc(const uastc_block& src_blk, void* pDst)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, true, false))
			return false;

		bool success = false;
		if (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			pack_astc_solid_block(pDst, unpacked_src_blk.m_solid_color);
			success = true;
		}
		else
		{
			success = pack_astc_block(static_cast<uint32_t*>(pDst), &unpacked_src_blk.m_astc, unpacked_src_blk.m_mode);
		}

		return success;
	}

	bool transcode_uastc_to_bc7(const unpacked_uastc_block& unpacked_src_blk, bc7_optimization_results& dst_blk)
	{
		memset(&dst_blk, 0, sizeof(dst_blk));

		const uint32_t mode = unpacked_src_blk.m_mode;

		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];
		const uint32_t total_comps = g_uastc_mode_comps[mode];

		switch (mode)
		{
		case 0:
		case 5:
		case 10:
		case 12:
		case 14:
		case 15:
		case 18:
		{
			// MODE 0: DualPlane: 0, WeightRange: 8 (16), Subsets: 1, EndpointRange: 19 (192) - BC7 MODE6 RGB
			// MODE 5: DualPlane: 0, WeightRange : 5 (8), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE6 RGB
			// MODE 10 DualPlane: 0, WeightRange: 8 (16), Subsets: 1, EndpointRange: 13 (48) - BC7 MODE6
			// MODE 12: DualPlane: 0, WeightRange : 5 (8), Subsets : 1, EndpointRange : 19 (192) - BC7 MODE6
			// MODE 14: DualPlane: 0, WeightRange : 2 (4), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE6
			// MODE 18: DualPlane: 0, WeightRange : 11 (32), Subsets : 1, CEM : 8, EndpointRange : 11 (32) - BC7 MODE6
			// MODE 15: DualPlane: 0, WeightRange : 8 (16), Subsets : 1, CEM : 4 (LA Direct), EndpointRange : 20 (256) - BC7 MODE6
			dst_blk.m_mode = 6;

			float xl[4], xh[4];
			if (total_comps == 2)
			{
				xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0]].m_unquant / 255.0f;
				xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1]].m_unquant / 255.0f;

				xl[1] = xl[0];
				xh[1] = xh[0];

				xl[2] = xl[0];
				xh[2] = xh[0];

				xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2]].m_unquant / 255.0f;
				xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3]].m_unquant / 255.0f;
			}
			else
			{
				xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0]].m_unquant / 255.0f;
				xl[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2]].m_unquant / 255.0f;
				xl[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[4]].m_unquant / 255.0f;

				xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1]].m_unquant / 255.0f;
				xh[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3]].m_unquant / 255.0f;
				xh[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[5]].m_unquant / 255.0f;

				if (total_comps == 4)
				{
					xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[6]].m_unquant / 255.0f;
					xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[7]].m_unquant / 255.0f;
				}
				else
				{
					xl[3] = 1.0f;
					xh[3] = 1.0f;
				}
			}

			uint32_t best_pbits[2];
			basisu::clear_obj(best_pbits);

			color_quad_u8 bestMinColor, bestMaxColor;
			determine_unique_pbits((total_comps == 2) ? 4 : total_comps, 7, xl, xh, bestMinColor, bestMaxColor, best_pbits);

			dst_blk.m_low[0] = bestMinColor;
			dst_blk.m_high[0] = bestMaxColor;

			if (total_comps == 3)
			{
				dst_blk.m_low[0].m_c[3] = 127;
				dst_blk.m_high[0].m_c[3] = 127;
			}

			dst_blk.m_pbits[0][0] = best_pbits[0];
			dst_blk.m_pbits[0][1] = best_pbits[1];

			if (mode == 18)
			{
				const uint8_t s_bc7_5_to_4[32] = { 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 6, 7, 8, 9, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15 };
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = s_bc7_5_to_4[unpacked_src_blk.m_astc.m_weights[i]];
			}
			else if (mode == 14)
			{
				const uint8_t s_bc7_2_to_4[4] = { 0, 5, 10, 15 };
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = s_bc7_2_to_4[unpacked_src_blk.m_astc.m_weights[i]];
			}
			else if ((mode == 5) || (mode == 12))
			{
				const uint8_t s_bc7_3_to_4[8] = { 0, 2, 4, 6, 9, 11, 13, 15 };
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = s_bc7_3_to_4[unpacked_src_blk.m_astc.m_weights[i]];
			}
			else
			{
				for (uint32_t i = 0; i < 16; i++)
					dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];
			}

			break;
		}
		case 1:
		{
			// DualPlane: 0, WeightRange : 2 (4), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE3
			// Mode 1 uses endpoint range 20 - no need to use ASTC dequant tables.
			dst_blk.m_mode = 3;

			float xl[4], xh[4];
			xl[0] = unpacked_src_blk.m_astc.m_endpoints[0] / 255.0f;
			xl[1] = unpacked_src_blk.m_astc.m_endpoints[2] / 255.0f;
			xl[2] = unpacked_src_blk.m_astc.m_endpoints[4] / 255.0f;
			xl[3] = 1.0f;

			xh[0] = unpacked_src_blk.m_astc.m_endpoints[1] / 255.0f;
			xh[1] = unpacked_src_blk.m_astc.m_endpoints[3] / 255.0f;
			xh[2] = unpacked_src_blk.m_astc.m_endpoints[5] / 255.0f;
			xh[3] = 1.0f;

			uint32_t best_pbits[2];
			color_quad_u8 bestMinColor, bestMaxColor;
			memset(&bestMinColor, 0, sizeof(bestMinColor));
			memset(&bestMaxColor, 0, sizeof(bestMaxColor));
			determine_unique_pbits(3, 7, xl, xh, bestMinColor, bestMaxColor, best_pbits);

			for (uint32_t i = 0; i < 3; i++)
			{
				dst_blk.m_low[0].m_c[i] = bestMinColor.m_c[i];
				dst_blk.m_high[0].m_c[i] = bestMaxColor.m_c[i];
				dst_blk.m_low[1].m_c[i] = bestMinColor.m_c[i];
				dst_blk.m_high[1].m_c[i] = bestMaxColor.m_c[i];
			}
			dst_blk.m_pbits[0][0] = best_pbits[0];
			dst_blk.m_pbits[0][1] = best_pbits[1];
			dst_blk.m_pbits[1][0] = best_pbits[0];
			dst_blk.m_pbits[1][1] = best_pbits[1];

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 2:
		{
			// 2. DualPlane: 0, WeightRange : 5 (8), Subsets : 2, EndpointRange : 8 (16) - BC7 MODE1 
			dst_blk.m_mode = 1;
			dst_blk.m_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_bc7;

			const bool invert_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_invert;

			float xl[4], xh[4];
			xl[3] = 1.0f;
			xh[3] = 1.0f;

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				for (uint32_t i = 0; i < 3; i++)
				{
					uint32_t v = unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6];
					v = (v << 4) | v;
					xl[i] = v / 255.0f;

					v = unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6 + 1];
					v = (v << 4) | v;
					xh[i] = v / 255.0f;
				}

				uint32_t best_pbits[2] = { 0, 0 };
				color_quad_u8 bestMinColor, bestMaxColor;
				memset(&bestMinColor, 0, sizeof(bestMinColor));
				memset(&bestMaxColor, 0, sizeof(bestMaxColor));
				determine_shared_pbits(3, 6, xl, xh, bestMinColor, bestMaxColor, best_pbits);

				const uint32_t bc7_subset_index = invert_partition ? (1 - subset) : subset;

				for (uint32_t i = 0; i < 3; i++)
				{
					dst_blk.m_low[bc7_subset_index].m_c[i] = bestMinColor.m_c[i];
					dst_blk.m_high[bc7_subset_index].m_c[i] = bestMaxColor.m_c[i];
				}

				dst_blk.m_pbits[bc7_subset_index][0] = best_pbits[0];
			} // subset

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 3:
		{
			// DualPlane: 0, WeightRange : 2 (4), Subsets : 3, EndpointRange : 7 (12) - BC7 MODE2
			dst_blk.m_mode = 2;
			dst_blk.m_partition = g_astc_bc7_common_partitions3[unpacked_src_blk.m_common_pattern].m_bc7;

			const uint32_t perm = g_astc_bc7_common_partitions3[unpacked_src_blk.m_common_pattern].m_astc_to_bc7_perm;

			for (uint32_t subset = 0; subset < 3; subset++)
			{
				for (uint32_t comp = 0; comp < 3; comp++)
				{
					uint32_t lo = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[comp * 2 + 0 + subset * 6]].m_unquant;
					uint32_t hi = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[comp * 2 + 1 + subset * 6]].m_unquant;

					// TODO: I think this can be improved by using tables like Basis Universal does with ETC1S conversion.
					lo = (lo * 31 + 127) / 255;
					hi = (hi * 31 + 127) / 255;

					const uint32_t bc7_subset_index = g_astc_to_bc7_partition_index_perm_tables[perm][subset];

					dst_blk.m_low[bc7_subset_index].m_c[comp] = (uint8_t)lo;
					dst_blk.m_high[bc7_subset_index].m_c[comp] = (uint8_t)hi;
				}
			}

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 4:
		{
			// 4. DualPlane: 0, WeightRange: 2 (4), Subsets: 2, EndpointRange: 12 (40) - BC7 MODE3
			dst_blk.m_mode = 3;
			dst_blk.m_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_bc7;

			const bool invert_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_invert;

			float xl[4], xh[4];
			xl[3] = 1.0f;
			xh[3] = 1.0f;

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				for (uint32_t i = 0; i < 3; i++)
				{
					xl[i] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6]].m_unquant / 255.0f;
					xh[i] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[i * 2 + subset * 6 + 1]].m_unquant / 255.0f;
				}

				uint32_t best_pbits[2] = { 0, 0 };
				color_quad_u8 bestMinColor, bestMaxColor;
				memset(&bestMinColor, 0, sizeof(bestMinColor));
				memset(&bestMaxColor, 0, sizeof(bestMaxColor));
				determine_unique_pbits(3, 7, xl, xh, bestMinColor, bestMaxColor, best_pbits);

				const uint32_t bc7_subset_index = invert_partition ? (1 - subset) : subset;

				for (uint32_t i = 0; i < 3; i++)
				{
					dst_blk.m_low[bc7_subset_index].m_c[i] = bestMinColor.m_c[i];
					dst_blk.m_high[bc7_subset_index].m_c[i] = bestMaxColor.m_c[i];
				}
				dst_blk.m_low[bc7_subset_index].m_c[3] = 127;
				dst_blk.m_high[bc7_subset_index].m_c[3] = 127;

				dst_blk.m_pbits[bc7_subset_index][0] = best_pbits[0];
				dst_blk.m_pbits[bc7_subset_index][1] = best_pbits[1];

			} // subset

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case 6:
		case 11:
		case 13:
		case 17:
		{
			// MODE 6: DualPlane: 1, WeightRange : 2 (4), Subsets : 1, EndpointRange : 18 (160) - BC7 MODE5 RGB
			// MODE 11: DualPlane: 1, WeightRange: 2 (4), Subsets: 1, EndpointRange: 13 (48) - BC7 MODE5
			// MODE 13: DualPlane: 1, WeightRange: 0 (2), Subsets : 1, EndpointRange : 20 (256) - BC7 MODE5
			// MODE 17: DualPlane: 1, WeightRange: 2 (4), Subsets: 1, CEM: 4 (LA Direct), EndpointRange: 20 (256) - BC7 MODE5
			dst_blk.m_mode = 5;
			dst_blk.m_rotation = (unpacked_src_blk.m_astc.m_ccs + 1) & 3;

			if (total_comps == 2)
			{
				assert(unpacked_src_blk.m_astc.m_ccs == 3);

				dst_blk.m_low->m_c[0] = (uint8_t)((g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0]].m_unquant * 127 + 127) / 255);
				dst_blk.m_high->m_c[0] = (uint8_t)((g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1]].m_unquant * 127 + 127) / 255);

				dst_blk.m_low->m_c[1] = dst_blk.m_low->m_c[0];
				dst_blk.m_high->m_c[1] = dst_blk.m_high->m_c[0];

				dst_blk.m_low->m_c[2] = dst_blk.m_low->m_c[0];
				dst_blk.m_high->m_c[2] = dst_blk.m_high->m_c[0];

				dst_blk.m_low->m_c[3] = (uint8_t)(g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2]].m_unquant);
				dst_blk.m_high->m_c[3] = (uint8_t)(g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3]].m_unquant);
			}
			else
			{
				for (uint32_t astc_comp = 0; astc_comp < 4; astc_comp++)
				{
					uint32_t bc7_comp = astc_comp;
					// ASTC and BC7 handle dual plane component rotations differently:
					// ASTC: 2nd plane separately interpolates the CCS channel.
					// BC7: 2nd plane channel is swapped with alpha, 2nd plane controls alpha interpolation, then we swap alpha with the desired channel.
					if (astc_comp == (uint32_t)unpacked_src_blk.m_astc.m_ccs)
						bc7_comp = 3;
					else if (astc_comp == 3)
						bc7_comp = unpacked_src_blk.m_astc.m_ccs;

					uint32_t l = 255, h = 255;
					if (astc_comp < total_comps)
					{
						l = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[astc_comp * 2 + 0]].m_unquant;
						h = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[astc_comp * 2 + 1]].m_unquant;
					}

					if (bc7_comp < 3)
					{
						l = (l * 127 + 127) / 255;
						h = (h * 127 + 127) / 255;
					}

					dst_blk.m_low->m_c[bc7_comp] = (uint8_t)l;
					dst_blk.m_high->m_c[bc7_comp] = (uint8_t)h;
				}
			}

			if (mode == 13)
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2] ? 3 : 0;
					dst_blk.m_alpha_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2 + 1] ? 3 : 0;
				}
			}
			else
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2];
					dst_blk.m_alpha_selectors[i] = unpacked_src_blk.m_astc.m_weights[i * 2 + 1];
				}
			}

			break;
		}
		case 7:
		{
			// DualPlane: 0, WeightRange : 2 (4), Subsets : 2, EndpointRange : 12 (40) - BC7 MODE2
			dst_blk.m_mode = 2;
			dst_blk.m_partition = g_bc7_3_astc2_common_partitions[unpacked_src_blk.m_common_pattern].m_bc73;

			const uint32_t common_pattern_k = g_bc7_3_astc2_common_partitions[unpacked_src_blk.m_common_pattern].k;

			for (uint32_t bc7_part = 0; bc7_part < 3; bc7_part++)
			{
				const uint32_t astc_part = bc7_convert_partition_index_3_to_2(bc7_part, common_pattern_k);

				for (uint32_t c = 0; c < 3; c++)
				{
					dst_blk.m_low[bc7_part].m_c[c] = (g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[c * 2 + 0 + astc_part * 6]].m_unquant * 31 + 127) / 255;
					dst_blk.m_high[bc7_part].m_c[c] = (g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[c * 2 + 1 + astc_part * 6]].m_unquant * 31 + 127) / 255;
				}
			}

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		case UASTC_MODE_INDEX_SOLID_COLOR:
		{
			// Void-Extent: Solid Color RGBA (BC7 MODE5 or MODE6)
			// TODO: Why prefer mode 6 here? Mode 5 is lossless.
			const color32& solid_color = unpacked_src_blk.m_solid_color;

			uint32_t best_err0 = g_bc7_mode_6_optimal_endpoints[solid_color.r][0].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.g][0].m_error +
				g_bc7_mode_6_optimal_endpoints[solid_color.b][0].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.a][0].m_error;

			uint32_t best_err1 = g_bc7_mode_6_optimal_endpoints[solid_color.r][1].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.g][1].m_error +
				g_bc7_mode_6_optimal_endpoints[solid_color.b][1].m_error + g_bc7_mode_6_optimal_endpoints[solid_color.a][1].m_error;

			if (best_err0 > 0 && best_err1 > 0)
			{
				dst_blk.m_mode = 5;

				for (uint32_t c = 0; c < 3; c++)
				{
					dst_blk.m_low[0].m_c[c] = g_bc7_mode_5_optimal_endpoints[solid_color.c[c]].m_lo;
					dst_blk.m_high[0].m_c[c] = g_bc7_mode_5_optimal_endpoints[solid_color.c[c]].m_hi;
				}

				memset(dst_blk.m_selectors, BC7ENC_MODE_5_OPTIMAL_INDEX, 16);

				dst_blk.m_low[0].m_c[3] = solid_color.c[3];
				dst_blk.m_high[0].m_c[3] = solid_color.c[3];

				//memset(dst_blk.m_alpha_selectors, 0, 16);
			}
			else
			{
				dst_blk.m_mode = 6;

				uint32_t best_p = 0;
				if (best_err1 < best_err0)
					best_p = 1;

				for (uint32_t c = 0; c < 4; c++)
				{
					dst_blk.m_low[0].m_c[c] = g_bc7_mode_6_optimal_endpoints[solid_color.c[c]][best_p].m_lo;
					dst_blk.m_high[0].m_c[c] = g_bc7_mode_6_optimal_endpoints[solid_color.c[c]][best_p].m_hi;
				}

				dst_blk.m_pbits[0][0] = best_p;
				dst_blk.m_pbits[0][1] = best_p;
				memset(dst_blk.m_selectors, BC7ENC_MODE_6_OPTIMAL_INDEX, 16);
			}

			break;
		}
		case 9:
		case 16:
		{
			// 9. DualPlane: 0, WeightRange : 2 (4), Subsets : 2, EndpointRange : 8 (16) - BC7 MODE7
			// 16. DualPlane: 0, WeightRange: 2 (4), Subsets: 2, CEM: 4 (LA Direct), EndpointRange: 20 (256) - BC7 MODE7

			dst_blk.m_mode = 7;
			dst_blk.m_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_bc7;

			const bool invert_partition = g_astc_bc7_common_partitions2[unpacked_src_blk.m_common_pattern].m_invert;

			for (uint32_t astc_subset = 0; astc_subset < 2; astc_subset++)
			{
				float xl[4], xh[4];

				if (total_comps == 2)
				{
					xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0 + astc_subset * 4]].m_unquant / 255.0f;
					xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1 + astc_subset * 4]].m_unquant / 255.0f;

					xl[1] = xl[0];
					xh[1] = xh[0];

					xl[2] = xl[0];
					xh[2] = xh[0];

					xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2 + astc_subset * 4]].m_unquant / 255.0f;
					xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3 + astc_subset * 4]].m_unquant / 255.0f;
				}
				else
				{
					xl[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[0 + astc_subset * 8]].m_unquant / 255.0f;
					xl[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[2 + astc_subset * 8]].m_unquant / 255.0f;
					xl[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[4 + astc_subset * 8]].m_unquant / 255.0f;
					xl[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[6 + astc_subset * 8]].m_unquant / 255.0f;

					xh[0] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[1 + astc_subset * 8]].m_unquant / 255.0f;
					xh[1] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[3 + astc_subset * 8]].m_unquant / 255.0f;
					xh[2] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[5 + astc_subset * 8]].m_unquant / 255.0f;
					xh[3] = g_astc_unquant[endpoint_range][unpacked_src_blk.m_astc.m_endpoints[7 + astc_subset * 8]].m_unquant / 255.0f;
				}

				uint32_t best_pbits[2] = { 0, 0 };
				color_quad_u8 bestMinColor, bestMaxColor;
				memset(&bestMinColor, 0, sizeof(bestMinColor));
				memset(&bestMaxColor, 0, sizeof(bestMaxColor));
				determine_unique_pbits(4, 5, xl, xh, bestMinColor, bestMaxColor, best_pbits);

				const uint32_t bc7_subset_index = invert_partition ? (1 - astc_subset) : astc_subset;

				dst_blk.m_low[bc7_subset_index] = bestMinColor;
				dst_blk.m_high[bc7_subset_index] = bestMaxColor;

				dst_blk.m_pbits[bc7_subset_index][0] = best_pbits[0];
				dst_blk.m_pbits[bc7_subset_index][1] = best_pbits[1];
			} // astc_subset

			for (uint32_t i = 0; i < 16; i++)
				dst_blk.m_selectors[i] = unpacked_src_blk.m_astc.m_weights[i];

			break;
		}
		default:
			return false;
		}

		return true;
	}

	bool transcode_uastc_to_bc7(const uastc_block& src_blk, bc7_optimization_results& dst_blk)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false, false))
			return false;

		return transcode_uastc_to_bc7(unpacked_src_blk, dst_blk);
	}

	bool transcode_uastc_to_bc7(const uastc_block& src_blk, void* pDst)
	{
		bc7_optimization_results temp;
		if (!transcode_uastc_to_bc7(src_blk, temp))
			return false;

		encode_bc7_block(pDst, &temp);
		return true;
	}

	color32 apply_etc1_bias(const color32 &block_color, uint32_t bias, uint32_t limit, uint32_t subblock)
	{
		color32 result;

		for (uint32_t c = 0; c < 3; c++)
		{
			static const int s_divs[3] = { 1, 3, 9 };

			int delta = 0;

			switch (bias)
			{
			case 2: delta = subblock ? 0 : ((c == 0) ? -1 : 0); break;
			case 5: delta = subblock ? 0 : ((c == 1) ? -1 : 0); break;
			case 6: delta = subblock ? 0 : ((c == 2) ? -1 : 0); break;

			case 7: delta = subblock ? 0 : ((c == 0) ? 1 : 0); break;
			case 11: delta = subblock ? 0 : ((c == 1) ? 1 : 0); break;
			case 15: delta = subblock ? 0 : ((c == 2) ? 1 : 0); break;

			case 18: delta = subblock ? ((c == 0) ? -1 : 0) : 0; break;
			case 19: delta = subblock ? ((c == 1) ? -1 : 0) : 0; break;
			case 20: delta = subblock ? ((c == 2) ? -1 : 0) : 0; break;

			case 21: delta = subblock ? ((c == 0) ? 1 : 0) : 0; break;
			case 24: delta = subblock ? ((c == 1) ? 1 : 0) : 0; break;
			case 8: delta = subblock ? ((c == 2) ? 1 : 0) : 0; break;

			case 10: delta = -2; break;

			case 27: delta = subblock ? 0 : -1; break;
			case 28: delta = subblock ? -1 : 1; break;
			case 29: delta = subblock ? 1 : 0; break;
			case 30: delta = subblock ? -1 : 0; break;
			case 31: delta = subblock ? 0 : 1; break;

			default:
				delta = ((bias / s_divs[c]) % 3) - 1;
				break;
			}

			int v = block_color[c];
			if (v == 0)
			{
				if (delta == -2)
					v += 3;
				else
					v += delta + 1;
			}
			else if (v == (int)limit)
			{
				v += (delta - 1);
			}
			else
			{
				v += delta;
				if ((v < 0) || (v > (int)limit))
					v = (v - delta) - delta;
			}

			assert(v >= 0);
			assert(v <= (int)limit);

			result[c] = (uint8_t)v;
		}

		return result;
	}

	static void etc1_determine_selectors(decoder_etc_block& dst_blk, const color32* pSource_pixels, uint32_t first_subblock, uint32_t last_subblock)
	{
		static const uint8_t s_tran[4] = { 1, 0, 2, 3 };

		uint16_t l_bitmask = 0;
		uint16_t h_bitmask = 0;

		for (uint32_t subblock = first_subblock; subblock < last_subblock; subblock++)
		{
			color32 block_colors[4];
			dst_blk.get_block_colors(block_colors, subblock);

			uint32_t block_y[4];
			for (uint32_t i = 0; i < 4; i++)
				block_y[i] = block_colors[i][0] * 54 + block_colors[i][1] * 183 + block_colors[i][2] * 19;

			const uint32_t block_y01 = block_y[0] + block_y[1];
			const uint32_t block_y12 = block_y[1] + block_y[2];
			const uint32_t block_y23 = block_y[2] + block_y[3];

			// X0 X0 X0 X0 X1 X1 X1 X1 X2 X2 X2 X2 X3 X3 X3 X3
			// Y0 Y1 Y2 Y3 Y0 Y1 Y2 Y3 Y0 Y1 Y2 Y3 Y0 Y1 Y2 Y3

			if (dst_blk.get_flip_bit())
			{
				uint32_t ofs = subblock * 2;

				for (uint32_t y = 0; y < 2; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						const color32& c = pSource_pixels[x + (subblock * 2 + y) * 4];
						const uint32_t l = c[0] * 108 + c[1] * 366 + c[2] * 38;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						ofs += 4;
					}

					ofs = (int)ofs + 1 - 4 * 4;
				}
			}
			else
			{
				uint32_t ofs = (subblock * 2) * 4;
				for (uint32_t x = 0; x < 2; x++)
				{
					for (uint32_t y = 0; y < 4; y++)
					{
						const color32& c = pSource_pixels[subblock * 2 + x + y * 4];
						const uint32_t l = c[0] * 108 + c[1] * 366 + c[2] * 38;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						++ofs;
					}
				}
			}
		}

		dst_blk.m_bytes[7] = (uint8_t)(l_bitmask);
		dst_blk.m_bytes[6] = (uint8_t)(l_bitmask >> 8);
		dst_blk.m_bytes[5] = (uint8_t)(h_bitmask);
		dst_blk.m_bytes[4] = (uint8_t)(h_bitmask >> 8);
	}

	static const uint8_t s_etc1_solid_selectors[4][4] = { { 255, 255, 255, 255 }, { 255, 255, 0, 0 }, { 0, 0, 0, 0 }, {0, 0, 255, 255 } };

	struct etc_coord2
	{
		uint8_t m_x, m_y;
	};

	// [flip][subblock][pixel_index]
	const etc_coord2 g_etc1_pixel_coords[2][2][8] =
	{
		{
		  {
			 { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 },
			 { 1, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 }
		  },
		  {
			 { 2, 0 }, { 2, 1 }, { 2, 2 }, { 2, 3 },
			 { 3, 0 }, { 3, 1 }, { 3, 2 }, { 3, 3 }
		  }
		},
		{
		  {
			 { 0, 0 }, { 1, 0 }, { 2, 0 }, { 3, 0 },
			 { 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }
		  },
		  {
			 { 0, 2 }, { 1, 2 }, { 2, 2 }, { 3, 2 },
			 { 0, 3 }, { 1, 3 }, { 2, 3 }, { 3, 3 }
		  },
		}
	};

	void transcode_uastc_to_etc1(unpacked_uastc_block& unpacked_src_blk, color32 block_pixels[4][4], void* pDst)
	{
		decoder_etc_block& dst_blk = *static_cast<decoder_etc_block*>(pDst);

		if (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			dst_blk.m_bytes[3] = (uint8_t)((unpacked_src_blk.m_etc1_diff << 1) | (unpacked_src_blk.m_etc1_inten0 << 5) | (unpacked_src_blk.m_etc1_inten0 << 2));

			if (unpacked_src_blk.m_etc1_diff)
			{
				dst_blk.m_bytes[0] = (uint8_t)(unpacked_src_blk.m_etc1_r << 3);
				dst_blk.m_bytes[1] = (uint8_t)(unpacked_src_blk.m_etc1_g << 3);
				dst_blk.m_bytes[2] = (uint8_t)(unpacked_src_blk.m_etc1_b << 3);
			}
			else
			{
				dst_blk.m_bytes[0] = (uint8_t)(unpacked_src_blk.m_etc1_r | (unpacked_src_blk.m_etc1_r << 4));
				dst_blk.m_bytes[1] = (uint8_t)(unpacked_src_blk.m_etc1_g | (unpacked_src_blk.m_etc1_g << 4));
				dst_blk.m_bytes[2] = (uint8_t)(unpacked_src_blk.m_etc1_b | (unpacked_src_blk.m_etc1_b << 4));
			}

			memcpy(dst_blk.m_bytes + 4, &s_etc1_solid_selectors[unpacked_src_blk.m_etc1_selector][0], 4);

			return;
		}

		const bool flip = unpacked_src_blk.m_etc1_flip != 0;
		const bool diff = unpacked_src_blk.m_etc1_diff != 0;

		dst_blk.m_bytes[3] = (uint8_t)((int)flip | (diff << 1) | (unpacked_src_blk.m_etc1_inten0 << 5) | (unpacked_src_blk.m_etc1_inten1 << 2));

		const uint32_t limit = diff ? 31 : 15;

		color32 block_colors[2];

		for (uint32_t subset = 0; subset < 2; subset++)
		{
			uint32_t avg_color[3];
			memset(avg_color, 0, sizeof(avg_color));

			for (uint32_t j = 0; j < 8; j++)
			{
				const etc_coord2& c = g_etc1_pixel_coords[flip][subset][j];

				avg_color[0] += block_pixels[c.m_y][c.m_x].r;
				avg_color[1] += block_pixels[c.m_y][c.m_x].g;
				avg_color[2] += block_pixels[c.m_y][c.m_x].b;
			} // j

			block_colors[subset][0] = (uint8_t)((avg_color[0] * limit + 1020) / (8 * 255));
			block_colors[subset][1] = (uint8_t)((avg_color[1] * limit + 1020) / (8 * 255));
			block_colors[subset][2] = (uint8_t)((avg_color[2] * limit + 1020) / (8 * 255));
			block_colors[subset][3] = 0;

			if (g_uastc_mode_has_etc1_bias[unpacked_src_blk.m_mode])
			{
				block_colors[subset] = apply_etc1_bias(block_colors[subset], unpacked_src_blk.m_etc1_bias, limit, subset);
			}

		} // subset

		if (diff)
		{
			int dr = block_colors[1].r - block_colors[0].r;
			int dg = block_colors[1].g - block_colors[0].g;
			int db = block_colors[1].b - block_colors[0].b;

			dr = basisu::clamp<int>(dr, cETC1ColorDeltaMin, cETC1ColorDeltaMax);
			dg = basisu::clamp<int>(dg, cETC1ColorDeltaMin, cETC1ColorDeltaMax);
			db = basisu::clamp<int>(db, cETC1ColorDeltaMin, cETC1ColorDeltaMax);

			if (dr < 0) dr += 8;
			if (dg < 0) dg += 8;
			if (db < 0) db += 8;

			dst_blk.m_bytes[0] = (uint8_t)((block_colors[0].r << 3) | dr);
			dst_blk.m_bytes[1] = (uint8_t)((block_colors[0].g << 3) | dg);
			dst_blk.m_bytes[2] = (uint8_t)((block_colors[0].b << 3) | db);
		}
		else
		{
			dst_blk.m_bytes[0] = (uint8_t)(block_colors[1].r | (block_colors[0].r << 4));
			dst_blk.m_bytes[1] = (uint8_t)(block_colors[1].g | (block_colors[0].g << 4));
			dst_blk.m_bytes[2] = (uint8_t)(block_colors[1].b | (block_colors[0].b << 4));
		}

		etc1_determine_selectors(dst_blk, &block_pixels[0][0], 0, 2);
	}

	bool transcode_uastc_to_etc1(const uastc_block& src_blk, void* pDst)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		color32 block_pixels[4][4];
		if (unpacked_src_blk.m_mode != UASTC_MODE_INDEX_SOLID_COLOR)
		{
			const bool unpack_srgb = false;
			if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
				return false;
		}

		transcode_uastc_to_etc1(unpacked_src_blk, block_pixels, pDst);

		return true;
	}

	static inline int gray_distance2(const uint8_t c, int y)
	{
		int gray_dist = (int)c - y;
		return gray_dist * gray_dist;
	}

	static bool pack_etc1_y_estimate_flipped(const uint8_t* pSrc_pixels,
		int& upper_avg, int& lower_avg, int& left_avg, int& right_avg)
	{
		int sums[2][2];

#define GET_XY(x, y) pSrc_pixels[(x) + ((y) * 4)]

		sums[0][0] = GET_XY(0, 0) + GET_XY(0, 1) + GET_XY(1, 0) + GET_XY(1, 1);
		sums[1][0] = GET_XY(2, 0) + GET_XY(2, 1) + GET_XY(3, 0) + GET_XY(3, 1);
		sums[0][1] = GET_XY(0, 2) + GET_XY(0, 3) + GET_XY(1, 2) + GET_XY(1, 3);
		sums[1][1] = GET_XY(2, 2) + GET_XY(2, 3) + GET_XY(3, 2) + GET_XY(3, 3);

		upper_avg = (sums[0][0] + sums[1][0] + 4) / 8;
		lower_avg = (sums[0][1] + sums[1][1] + 4) / 8;
		left_avg = (sums[0][0] + sums[0][1] + 4) / 8;
		right_avg = (sums[1][0] + sums[1][1] + 4) / 8;

#undef GET_XY
#define GET_XY(x, y, a) gray_distance2(pSrc_pixels[(x) + ((y) * 4)], a)

		int upper_gray_dist = 0, lower_gray_dist = 0, left_gray_dist = 0, right_gray_dist = 0;
		for (uint32_t i = 0; i < 4; i++)
		{
			for (uint32_t j = 0; j < 2; j++)
			{
				upper_gray_dist += GET_XY(i, j, upper_avg);
				lower_gray_dist += GET_XY(i, 2 + j, lower_avg);
				left_gray_dist += GET_XY(j, i, left_avg);
				right_gray_dist += GET_XY(2 + j, i, right_avg);
			}
		}

#undef GET_XY

		int upper_lower_sum = upper_gray_dist + lower_gray_dist;
		int left_right_sum = left_gray_dist + right_gray_dist;

		return upper_lower_sum < left_right_sum;
	}

	// Base  Sel Table
	// XXXXX XX  XXX
	static const uint16_t g_etc1_y_solid_block_configs[256] =
	{
		0,781,64,161,260,192,33,131,96,320,65,162,261,193,34,291,97,224,66,163,262,194,35,549,98,4,67,653,164,195,523,36,99,5,578,68,165,353,196,37,135,100,324,69,166,354,197,38,295,101,228,70,167,
		355,198,39,553,102,8,71,608,168,199,527,40,103,9,582,72,169,357,200,41,139,104,328,73,170,358,201,42,299,105,232,74,171,359,202,43,557,106,12,75,612,172,203,531,44,107,13,586,76,173,361,
		204,45,143,108,332,77,174,362,205,46,303,109,236,78,175,363,206,47,561,110,16,79,616,176,207,535,48,111,17,590,80,177,365,208,49,147,112,336,81,178,366,209,50,307,113,240,82,179,367,210,
		51,565,114,20,83,620,180,211,539,52,115,21,594,84,181,369,212,53,151,116,340,85,182,370,213,54,311,117,244,86,183,371,214,55,569,118,24,87,624,184,215,543,56,119,25,598,88,185,373,216,57,
		155,120,344,89,186,374,217,58,315,121,248,90,187,375,218,59,573,122,28,91,628,188,219,754,60,123,29,602,92,189,377,220,61,159,124,348,93,190,378,221,62,319,125,252,94,191,379,222,63,882,126
	};

	// individual
	// table base sel0 sel1 sel2 sel3
	static const uint16_t g_etc1_y_solid_block_4i_configs[256] =
	{
		0xA000,0xA800,0x540B,0xAA01,0xAA01,0xFE00,0xFF00,0xFF00,0x8,0x5515,0x5509,0x5509,0xAA03,0x5508,0x5508,0x9508,0xA508,0xA908,0xAA08,0x5513,0xAA09,0xAA09,0xAA05,0xFF08,0xFF08,0x10,0x551D,0x5511,0x5511,
		0xAA0B,0x5510,0x5510,0x9510,0xA510,0xA910,0xAA10,0x551B,0xAA11,0xAA11,0xAA0D,0xFF10,0xFF10,0x18,0x5525,0x5519,0x5519,0xAA13,0x5518,0x5518,0x9518,0xA518,0xA918,0xAA18,0x5523,0xAA19,0xAA19,0xAA15,
		0xFF18,0xFF18,0x20,0x552D,0x5521,0x5521,0xAA1B,0x5520,0x5520,0x9520,0xA520,0xA920,0xAA20,0x552B,0xAA21,0xAA21,0xAA1D,0xFF20,0xFF20,0x28,0x5535,0x5529,0x5529,0xAA23,0x5528,0x5528,0x9528,0xA528,0xA928,
		0xAA28,0x5533,0xAA29,0xAA29,0xAA25,0xFF28,0xFF28,0x30,0x553D,0x5531,0x5531,0xAA2B,0x5530,0x5530,0x9530,0xA530,0xA930,0xAA30,0x553B,0xAA31,0xAA31,0xAA2D,0xFF30,0xFF30,0x38,0x5545,0x5539,0x5539,0xAA33,
		0x5538,0x5538,0x9538,0xA538,0xA938,0xAA38,0x5543,0xAA39,0xAA39,0xAA35,0xFF38,0xFF38,0x40,0x554D,0x5541,0x5541,0xAA3B,0x5540,0x5540,0x9540,0xA540,0xA940,0xAA40,0x554B,0xAA41,0xAA41,0xAA3D,0xFF40,0xFF40,
		0x48,0x5555,0x5549,0x5549,0xAA43,0x5548,0x5548,0x9548,0xA548,0xA948,0xAA48,0x5553,0xAA49,0xAA49,0xAA45,0xFF48,0xFF48,0x50,0x555D,0x5551,0x5551,0xAA4B,0x5550,0x5550,0x9550,0xA550,0xA950,0xAA50,0x555B,
		0xAA51,0xAA51,0xAA4D,0xFF50,0xFF50,0x58,0x5565,0x5559,0x5559,0xAA53,0x5558,0x5558,0x9558,0xA558,0xA958,0xAA58,0x5563,0xAA59,0xAA59,0xAA55,0xFF58,0xFF58,0x60,0x556D,0x5561,0x5561,0xAA5B,0x5560,0x5560,
		0x9560,0xA560,0xA960,0xAA60,0x556B,0xAA61,0xAA61,0xAA5D,0xFF60,0xFF60,0x68,0x5575,0x5569,0x5569,0xAA63,0x5568,0x5568,0x9568,0xA568,0xA968,0xAA68,0x5573,0xAA69,0xAA69,0xAA65,0xFF68,0xFF68,0x70,0x557D,
		0x5571,0x5571,0xAA6B,0x5570,0x5570,0x9570,0xA570,0xA970,0xAA70,0x557B,0xAA71,0xAA71,0xAA6D,0xFF70,0xFF70,0x78,0x78,0x5579,0x5579,0xAA73,0x5578,0x9578,0x2578,0xE6E,0x278
	};

	static const uint16_t g_etc1_y_solid_block_2i_configs[256] =
	{
		0x416,0x800,0xA00,0x50B,0xA01,0xA01,0xF00,0xF00,0xF00,0x8,0x515,0x509,0x509,0xA03,0x508,0x508,0xF01,0xF01,0xA08,0xA08,0x513,0xA09,0xA09,0xA05,0xF08,0xF08,0x10,0x51D,0x511,0x511,0xA0B,0x510,0x510,0xF09,
		0xF09,0xA10,0xA10,0x51B,0xA11,0xA11,0xA0D,0xF10,0xF10,0x18,0x525,0x519,0x519,0xA13,0x518,0x518,0xF11,0xF11,0xA18,0xA18,0x523,0xA19,0xA19,0xA15,0xF18,0xF18,0x20,0x52D,0x521,0x521,0xA1B,0x520,0x520,0xF19,
		0xF19,0xA20,0xA20,0x52B,0xA21,0xA21,0xA1D,0xF20,0xF20,0x28,0x535,0x529,0x529,0xA23,0x528,0x528,0xF21,0xF21,0xA28,0xA28,0x533,0xA29,0xA29,0xA25,0xF28,0xF28,0x30,0x53D,0x531,0x531,0xA2B,0x530,0x530,0xF29,
		0xF29,0xA30,0xA30,0x53B,0xA31,0xA31,0xA2D,0xF30,0xF30,0x38,0x545,0x539,0x539,0xA33,0x538,0x538,0xF31,0xF31,0xA38,0xA38,0x543,0xA39,0xA39,0xA35,0xF38,0xF38,0x40,0x54D,0x541,0x541,0xA3B,0x540,0x540,0xF39,
		0xF39,0xA40,0xA40,0x54B,0xA41,0xA41,0xA3D,0xF40,0xF40,0x48,0x555,0x549,0x549,0xA43,0x548,0x548,0xF41,0xF41,0xA48,0xA48,0x553,0xA49,0xA49,0xA45,0xF48,0xF48,0x50,0x55D,0x551,0x551,0xA4B,0x550,0x550,0xF49,
		0xF49,0xA50,0xA50,0x55B,0xA51,0xA51,0xA4D,0xF50,0xF50,0x58,0x565,0x559,0x559,0xA53,0x558,0x558,0xF51,0xF51,0xA58,0xA58,0x563,0xA59,0xA59,0xA55,0xF58,0xF58,0x60,0x56D,0x561,0x561,0xA5B,0x560,0x560,0xF59,
		0xF59,0xA60,0xA60,0x56B,0xA61,0xA61,0xA5D,0xF60,0xF60,0x68,0x575,0x569,0x569,0xA63,0x568,0x568,0xF61,0xF61,0xA68,0xA68,0x573,0xA69,0xA69,0xA65,0xF68,0xF68,0x70,0x57D,0x571,0x571,0xA6B,0x570,0x570,0xF69,
		0xF69,0xA70,0xA70,0x57B,0xA71,0xA71,0xA6D,0xF70,0xF70,0x78,0x78,0x579,0x579,0xA73,0x578,0x578,0xE6E,0x278
	};

	static const uint16_t g_etc1_y_solid_block_1i_configs[256] =
	{
		0x0,0x116,0x200,0x200,0x10B,0x201,0x201,0x300,0x300,0x8,0x115,0x109,0x109,0x203,0x108,0x108,0x114,0x301,0x204,0x208,0x208,0x113,0x209,0x209,0x205,0x308,0x10,0x11D,0x111,0x111,0x20B,0x110,0x110,0x11C,0x309,
		0x20C,0x210,0x210,0x11B,0x211,0x211,0x20D,0x310,0x18,0x125,0x119,0x119,0x213,0x118,0x118,0x124,0x311,0x214,0x218,0x218,0x123,0x219,0x219,0x215,0x318,0x20,0x12D,0x121,0x121,0x21B,0x120,0x120,0x12C,0x319,0x21C,
		0x220,0x220,0x12B,0x221,0x221,0x21D,0x320,0x28,0x135,0x129,0x129,0x223,0x128,0x128,0x134,0x321,0x224,0x228,0x228,0x133,0x229,0x229,0x225,0x328,0x30,0x13D,0x131,0x131,0x22B,0x130,0x130,0x13C,0x329,0x22C,0x230,
		0x230,0x13B,0x231,0x231,0x22D,0x330,0x38,0x145,0x139,0x139,0x233,0x138,0x138,0x144,0x331,0x234,0x238,0x238,0x143,0x239,0x239,0x235,0x338,0x40,0x14D,0x141,0x141,0x23B,0x140,0x140,0x14C,0x339,0x23C,0x240,0x240,
		0x14B,0x241,0x241,0x23D,0x340,0x48,0x155,0x149,0x149,0x243,0x148,0x148,0x154,0x341,0x244,0x248,0x248,0x153,0x249,0x249,0x245,0x348,0x50,0x15D,0x151,0x151,0x24B,0x150,0x150,0x15C,0x349,0x24C,0x250,0x250,0x15B,
		0x251,0x251,0x24D,0x350,0x58,0x165,0x159,0x159,0x253,0x158,0x158,0x164,0x351,0x254,0x258,0x258,0x163,0x259,0x259,0x255,0x358,0x60,0x16D,0x161,0x161,0x25B,0x160,0x160,0x16C,0x359,0x25C,0x260,0x260,0x16B,0x261,
		0x261,0x25D,0x360,0x68,0x175,0x169,0x169,0x263,0x168,0x168,0x174,0x361,0x264,0x268,0x268,0x173,0x269,0x269,0x265,0x368,0x70,0x17D,0x171,0x171,0x26B,0x170,0x170,0x17C,0x369,0x26C,0x270,0x270,0x17B,0x271,0x271,
		0x26D,0x370,0x78,0x78,0x179,0x179,0x273,0x178,0x178,0x26E,0x278
	};

	// We don't have any useful hints to accelerate single channel ETC1, so we need to real-time encode from scratch.
	bool transcode_uastc_to_etc1(const uastc_block& src_blk, void* pDst, uint32_t channel)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

#if 0
		for (uint32_t individ = 0; individ < 2; individ++)
		{
			uint32_t overall_error = 0;

			for (uint32_t c = 0; c < 256; c++)
			{
				uint32_t best_err = UINT32_MAX;
				uint32_t best_individ = 0;
				uint32_t best_base = 0;
				uint32_t best_sels[4] = { 0,0,0,0 };
				uint32_t best_table = 0;

				const uint32_t limit = individ ? 16 : 32;

				for (uint32_t table = 0; table < 8; table++)
				{
					for (uint32_t base = 0; base < limit; base++)
					{
						uint32_t total_e = 0;
						uint32_t sels[4] = { 0,0,0,0 };

						const uint32_t N = 4;
						for (uint32_t i = 0; i < basisu::minimum<uint32_t>(N, (256 - c)); i++)
						{
							uint32_t best_sel_e = UINT32_MAX;
							uint32_t best_sel = 0;

							for (uint32_t sel = 0; sel < 4; sel++)
							{
								int val = individ ? ((base << 4) | base) : ((base << 3) | (base >> 2));
								val = clamp255(val + g_etc1_inten_tables[table][sel]);

								int e = iabs(val - clamp255(c + i));
								if (e < best_sel_e)
								{
									best_sel_e = e;
									best_sel = sel;
								}

							} // sel

							sels[i] = best_sel;
							total_e += best_sel_e * best_sel_e;

						} // i

						if (total_e < best_err)
						{
							best_err = total_e;
							best_individ = individ;
							best_base = base;
							memcpy(best_sels, sels, sizeof(best_sels));
							best_table = table;
						}

					} // base
				} // table

				//printf("%u: %u,%u,%u,%u,%u,%u,%u,%u\n", c, best_err, best_individ, best_table, best_base, best_sels[0], best_sels[1], best_sels[2], best_sels[3]);

				uint32_t encoded = best_table | (best_base << 3) |
					(best_sels[0] << 8) |
					(best_sels[1] << 10) |
					(best_sels[2] << 12) |
					(best_sels[3] << 14);

				printf("0x%X,", encoded);

				overall_error += best_err;
			} // c

			printf("\n");
			printf("Overall error: %u\n", overall_error);

		} // individ

		exit(0);
#endif

#if 0
		for (uint32_t individ = 0; individ < 2; individ++)
		{
			uint32_t overall_error = 0;

			for (uint32_t c = 0; c < 256; c++)
			{
				uint32_t best_err = UINT32_MAX;
				uint32_t best_individ = 0;
				uint32_t best_base = 0;
				uint32_t best_sels[4] = { 0,0,0,0 };
				uint32_t best_table = 0;

				const uint32_t limit = individ ? 16 : 32;

				for (uint32_t table = 0; table < 8; table++)
				{
					for (uint32_t base = 0; base < limit; base++)
					{
						uint32_t total_e = 0;
						uint32_t sels[4] = { 0,0,0,0 };

						const uint32_t N = 1;
						for (uint32_t i = 0; i < basisu::minimum<uint32_t>(N, (256 - c)); i++)
						{
							uint32_t best_sel_e = UINT32_MAX;
							uint32_t best_sel = 0;

							for (uint32_t sel = 0; sel < 4; sel++)
							{
								int val = individ ? ((base << 4) | base) : ((base << 3) | (base >> 2));
								val = clamp255(val + g_etc1_inten_tables[table][sel]);

								int e = iabs(val - clamp255(c + i));
								if (e < best_sel_e)
								{
									best_sel_e = e;
									best_sel = sel;
								}

							} // sel

							sels[i] = best_sel;
							total_e += best_sel_e * best_sel_e;

						} // i

						if (total_e < best_err)
						{
							best_err = total_e;
							best_individ = individ;
							best_base = base;
							memcpy(best_sels, sels, sizeof(best_sels));
							best_table = table;
						}

					} // base
				} // table

				//printf("%u: %u,%u,%u,%u,%u,%u,%u,%u\n", c, best_err, best_individ, best_table, best_base, best_sels[0], best_sels[1], best_sels[2], best_sels[3]);

				uint32_t encoded = best_table | (best_base << 3) |
					(best_sels[0] << 8) |
					(best_sels[1] << 10) |
					(best_sels[2] << 12) |
					(best_sels[3] << 14);

				printf("0x%X,", encoded);

				overall_error += best_err;
			} // c

			printf("\n");
			printf("Overall error: %u\n", overall_error);

		} // individ

		exit(0);
#endif

		decoder_etc_block& dst_blk = *static_cast<decoder_etc_block*>(pDst);

		if (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			const uint32_t y = unpacked_src_blk.m_solid_color[channel];
			const uint32_t encoded_config = g_etc1_y_solid_block_configs[y];

			const uint32_t base = encoded_config & 31;
			const uint32_t sel = (encoded_config >> 5) & 3;
			const uint32_t table = encoded_config >> 7;

			dst_blk.m_bytes[3] = (uint8_t)(2 | (table << 5) | (table << 2));

			dst_blk.m_bytes[0] = (uint8_t)(base << 3);
			dst_blk.m_bytes[1] = (uint8_t)(base << 3);
			dst_blk.m_bytes[2] = (uint8_t)(base << 3);

			memcpy(dst_blk.m_bytes + 4, &s_etc1_solid_selectors[sel][0], 4);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		uint8_t block_y[4][4];
		for (uint32_t i = 0; i < 16; i++)
			((uint8_t*)block_y)[i] = ((color32*)block_pixels)[i][channel];

		int upper_avg, lower_avg, left_avg, right_avg;
		bool flip = pack_etc1_y_estimate_flipped(&block_y[0][0], upper_avg, lower_avg, left_avg, right_avg);

		// non-flipped: | |
		// vs. 
		// flipped:     --
		//              --

		uint32_t low[2] = { 255, 255 }, high[2] = { 0, 0 };

		if (flip)
		{
			for (uint32_t y = 0; y < 2; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					const uint32_t v = block_y[y][x];
					low[0] = basisu::minimum(low[0], v);
					high[0] = basisu::maximum(high[0], v);
				}
			}
			for (uint32_t y = 2; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					const uint32_t v = block_y[y][x];
					low[1] = basisu::minimum(low[1], v);
					high[1] = basisu::maximum(high[1], v);
				}
			}
		}
		else
		{
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 2; x++)
				{
					const uint32_t v = block_y[y][x];
					low[0] = basisu::minimum(low[0], v);
					high[0] = basisu::maximum(high[0], v);
				}
			}
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 2; x < 4; x++)
				{
					const uint32_t v = block_y[y][x];
					low[1] = basisu::minimum(low[1], v);
					high[1] = basisu::maximum(high[1], v);
				}
			}
		}

		const uint32_t range[2] = { high[0] - low[0], high[1] - low[1] };

		dst_blk.m_bytes[3] = (uint8_t)((int)flip);

		if ((range[0] <= 3) && (range[1] <= 3))
		{
			// This is primarily for better gradients.
			dst_blk.m_bytes[0] = 0;
			dst_blk.m_bytes[1] = 0;
			dst_blk.m_bytes[2] = 0;

			uint16_t l_bitmask = 0, h_bitmask = 0;

			for (uint32_t subblock = 0; subblock < 2; subblock++)
			{
				const uint32_t encoded = (range[subblock] == 0) ? g_etc1_y_solid_block_1i_configs[low[subblock]] : ((range[subblock] < 2) ? g_etc1_y_solid_block_2i_configs[low[subblock]] : g_etc1_y_solid_block_4i_configs[low[subblock]]);

				const uint32_t table = encoded & 7;
				const uint32_t base = (encoded >> 3) & 31;
				assert(base <= 15);
				const uint32_t sels[4] = { (encoded >> 8) & 3, (encoded >> 10) & 3, (encoded >> 12) & 3, (encoded >> 14) & 3 };

				dst_blk.m_bytes[3] |= (uint8_t)(table << (subblock ? 2 : 5));

				const uint32_t sv = base << (subblock ? 0 : 4);
				dst_blk.m_bytes[0] |= (uint8_t)(sv);
				dst_blk.m_bytes[1] |= (uint8_t)(sv);
				dst_blk.m_bytes[2] |= (uint8_t)(sv);

				if (flip)
				{
					uint32_t ofs = subblock * 2;
					for (uint32_t y = 0; y < 2; y++)
					{
						for (uint32_t x = 0; x < 4; x++)
						{
							uint32_t t = block_y[y + subblock * 2][x];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							ofs += 4;
						}

						ofs = (int)ofs + 1 - 4 * 4;
					}
				}
				else
				{
					uint32_t ofs = (subblock * 2) * 4;
					for (uint32_t x = 0; x < 2; x++)
					{
						for (uint32_t y = 0; y < 4; y++)
						{
							uint32_t t = block_y[y][x + subblock * 2];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							++ofs;
						}
					}
				}
			} // subblock

			dst_blk.m_bytes[7] = (uint8_t)(l_bitmask);
			dst_blk.m_bytes[6] = (uint8_t)(l_bitmask >> 8);
			dst_blk.m_bytes[5] = (uint8_t)(h_bitmask);
			dst_blk.m_bytes[4] = (uint8_t)(h_bitmask >> 8);

			return true;
		}

		uint32_t y0 = ((flip ? upper_avg : left_avg) * 31 + 127) / 255;
		uint32_t y1 = ((flip ? lower_avg : right_avg) * 31 + 127) / 255;

		bool diff = true;

		int dy = y1 - y0;

		if ((dy < cETC1ColorDeltaMin) || (dy > cETC1ColorDeltaMax))
		{
			diff = false;

			y0 = ((flip ? upper_avg : left_avg) * 15 + 127) / 255;
			y1 = ((flip ? lower_avg : right_avg) * 15 + 127) / 255;

			dst_blk.m_bytes[0] = (uint8_t)(y1 | (y0 << 4));
			dst_blk.m_bytes[1] = (uint8_t)(y1 | (y0 << 4));
			dst_blk.m_bytes[2] = (uint8_t)(y1 | (y0 << 4));
		}
		else
		{
			dy = basisu::clamp<int>(dy, cETC1ColorDeltaMin, cETC1ColorDeltaMax);

			y1 = y0 + dy;

			if (dy < 0) dy += 8;

			dst_blk.m_bytes[0] = (uint8_t)((y0 << 3) | dy);
			dst_blk.m_bytes[1] = (uint8_t)((y0 << 3) | dy);
			dst_blk.m_bytes[2] = (uint8_t)((y0 << 3) | dy);

			dst_blk.m_bytes[3] |= 2;
		}

		const uint32_t base_y[2] = { diff ? ((y0 << 3) | (y0 >> 2)) : ((y0 << 4) | y0), diff ? ((y1 << 3) | (y1 >> 2)) : ((y1 << 4) | y1) };

		uint32_t enc_range[2];
		for (uint32_t subset = 0; subset < 2; subset++)
		{
			const int pos = basisu::iabs((int)high[subset] - (int)base_y[subset]);
			const int neg = basisu::iabs((int)base_y[subset] - (int)low[subset]);

			enc_range[subset] = basisu::maximum(pos, neg);
		}

		uint16_t l_bitmask = 0, h_bitmask = 0;
		for (uint32_t subblock = 0; subblock < 2; subblock++)
		{
			if ((!diff) && (range[subblock] <= 3))
			{
				const uint32_t encoded = (range[subblock] == 0) ? g_etc1_y_solid_block_1i_configs[low[subblock]] : ((range[subblock] < 2) ? g_etc1_y_solid_block_2i_configs[low[subblock]] : g_etc1_y_solid_block_4i_configs[low[subblock]]);

				const uint32_t table = encoded & 7;
				const uint32_t base = (encoded >> 3) & 31;
				assert(base <= 15);
				const uint32_t sels[4] = { (encoded >> 8) & 3, (encoded >> 10) & 3, (encoded >> 12) & 3, (encoded >> 14) & 3 };

				dst_blk.m_bytes[3] |= (uint8_t)(table << (subblock ? 2 : 5));

				const uint32_t mask = ~(0xF << (subblock ? 0 : 4));

				dst_blk.m_bytes[0] &= mask;
				dst_blk.m_bytes[1] &= mask;
				dst_blk.m_bytes[2] &= mask;

				const uint32_t sv = base << (subblock ? 0 : 4);
				dst_blk.m_bytes[0] |= (uint8_t)(sv);
				dst_blk.m_bytes[1] |= (uint8_t)(sv);
				dst_blk.m_bytes[2] |= (uint8_t)(sv);

				if (flip)
				{
					uint32_t ofs = subblock * 2;
					for (uint32_t y = 0; y < 2; y++)
					{
						for (uint32_t x = 0; x < 4; x++)
						{
							uint32_t t = block_y[y + subblock * 2][x];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							ofs += 4;
						}

						ofs = (int)ofs + 1 - 4 * 4;
					}
				}
				else
				{
					uint32_t ofs = (subblock * 2) * 4;
					for (uint32_t x = 0; x < 2; x++)
					{
						for (uint32_t y = 0; y < 4; y++)
						{
							uint32_t t = block_y[y][x + subblock * 2];
							assert(t >= low[subblock] && t <= high[subblock]);
							t -= low[subblock];
							assert(t <= 3);

							t = g_selector_index_to_etc1[sels[t]];

							assert(ofs < 16);
							l_bitmask |= ((t & 1) << ofs);
							h_bitmask |= ((t >> 1) << ofs);
							++ofs;
						}
					}
				}

				continue;
			} // if

			uint32_t best_err = UINT32_MAX;
			uint8_t best_sels[8];
			uint32_t best_inten = 0;

			const int base = base_y[subblock];

			const int low_limit = -base;
			const int high_limit = 255 - base;

			assert(low_limit <= 0 && high_limit >= 0);

			uint32_t inten_table_mask = 0xFF;
			const uint32_t er = enc_range[subblock];
			// Each one of these tables is expensive to evaluate, so let's only examine the ones we know may be useful.
			if (er <= 51)
			{
				inten_table_mask = 0xF;

				if (er > 22)
					inten_table_mask &= ~(1 << 0);

				if ((er < 4) || (er > 39))
					inten_table_mask &= ~(1 << 1);

				if (er < 9)
					inten_table_mask &= ~(1 << 2);

				if (er < 12)
					inten_table_mask &= ~(1 << 3);
			}
			else
			{
				inten_table_mask &= ~((1 << 0) | (1 << 1));

				if (er > 60)
					inten_table_mask &= ~(1 << 2);

				if (er > 89)
					inten_table_mask &= ~(1 << 3);

				if (er > 120)
					inten_table_mask &= ~(1 << 4);

				if (er > 136)
					inten_table_mask &= ~(1 << 5);

				if (er > 174)
					inten_table_mask &= ~(1 << 6);
			}

			for (uint32_t inten = 0; inten < 8; inten++)
			{
				if ((inten_table_mask & (1 << inten)) == 0)
					continue;

				const int t0 = basisu::maximum(low_limit, g_etc1_inten_tables[inten][0]);
				const int t1 = basisu::maximum(low_limit, g_etc1_inten_tables[inten][1]);
				const int t2 = basisu::minimum(high_limit, g_etc1_inten_tables[inten][2]);
				const int t3 = basisu::minimum(high_limit, g_etc1_inten_tables[inten][3]);
				assert((t0 <= t1) && (t1 <= t2) && (t2 <= t3));

				const int tv[4] = { t2, t3, t1, t0 };

				const int thresh01 = t0 + t1;
				const int thresh12 = t1 + t2;
				const int thresh23 = t2 + t3;

				assert(thresh01 <= thresh12 && thresh12 <= thresh23);

				static const uint8_t s_table[4] = { 1, 0, 2, 3 };

				uint32_t total_err = 0;
				uint8_t sels[8];

				if (flip)
				{
					if (((int)high[subblock] - base) * 2 < thresh01)
					{
						memset(sels, 3, 8);

						for (uint32_t y = 0; y < 2; y++)
						{
							for (uint32_t x = 0; x < 4; x++)
							{
								const int delta = (int)block_y[y + subblock * 2][x] - base;

								const uint32_t c = 3;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else if (((int)low[subblock] - base) * 2 >= thresh23)
					{
						memset(sels, 1, 8);

						for (uint32_t y = 0; y < 2; y++)
						{
							for (uint32_t x = 0; x < 4; x++)
							{
								const int delta = (int)block_y[y + subblock * 2][x] - base;

								const uint32_t c = 1;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else
					{
						for (uint32_t y = 0; y < 2; y++)
						{
							for (uint32_t x = 0; x < 4; x++)
							{
								const int delta = (int)block_y[y + subblock * 2][x] - base;
								const int delta2 = delta * 2;

								uint32_t c = s_table[(delta2 < thresh01) + (delta2 < thresh12) + (delta2 < thresh23)];
								sels[y * 4 + x] = (uint8_t)c;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
				}
				else
				{
					if (((int)high[subblock] - base) * 2 < thresh01)
					{
						memset(sels, 3, 8);

						for (uint32_t y = 0; y < 4; y++)
						{
							for (uint32_t x = 0; x < 2; x++)
							{
								const int delta = (int)block_y[y][x + subblock * 2] - base;

								const uint32_t c = 3;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else if (((int)low[subblock] - base) * 2 >= thresh23)
					{
						memset(sels, 1, 8);

						for (uint32_t y = 0; y < 4; y++)
						{
							for (uint32_t x = 0; x < 2; x++)
							{
								const int delta = (int)block_y[y][x + subblock * 2] - base;

								const uint32_t c = 1;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
					else
					{
						for (uint32_t y = 0; y < 4; y++)
						{
							for (uint32_t x = 0; x < 2; x++)
							{
								const int delta = (int)block_y[y][x + subblock * 2] - base;
								const int delta2 = delta * 2;

								uint32_t c = s_table[(delta2 < thresh01) + (delta2 < thresh12) + (delta2 < thresh23)];
								sels[y * 2 + x] = (uint8_t)c;

								uint32_t e = basisu::iabs(tv[c] - delta);
								total_err += e * e;
							}
							if (total_err >= best_err)
								break;
						}
					}
				}

				if (total_err < best_err)
				{
					best_err = total_err;
					best_inten = inten;
					memcpy(best_sels, sels, 8);
				}

			} // inten

			//g_inten_hist[best_inten][enc_range[subblock]]++;

			dst_blk.m_bytes[3] |= (uint8_t)(best_inten << (subblock ? 2 : 5));

			if (flip)
			{
				uint32_t ofs = subblock * 2;
				for (uint32_t y = 0; y < 2; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						uint32_t t = best_sels[y * 4 + x];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						ofs += 4;
					}

					ofs = (int)ofs + 1 - 4 * 4;
				}
			}
			else
			{
				uint32_t ofs = (subblock * 2) * 4;
				for (uint32_t x = 0; x < 2; x++)
				{
					for (uint32_t y = 0; y < 4; y++)
					{
						uint32_t t = best_sels[y * 2 + x];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						++ofs;
					}
				}
			}

		} // subblock

		dst_blk.m_bytes[7] = (uint8_t)(l_bitmask);
		dst_blk.m_bytes[6] = (uint8_t)(l_bitmask >> 8);
		dst_blk.m_bytes[5] = (uint8_t)(h_bitmask);
		dst_blk.m_bytes[4] = (uint8_t)(h_bitmask >> 8);

		return true;
	}

	const uint32_t ETC2_EAC_MIN_VALUE_SELECTOR = 3, ETC2_EAC_MAX_VALUE_SELECTOR = 7;

	void transcode_uastc_to_etc2_eac_a8(unpacked_uastc_block& unpacked_src_blk, color32 block_pixels[4][4], void* pDst)
	{
		eac_block& dst = *static_cast<eac_block*>(pDst);
		const color32* pSrc_pixels = &block_pixels[0][0];

		if ((!g_uastc_mode_has_alpha[unpacked_src_blk.m_mode]) || (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR))
		{
			const uint32_t a = (unpacked_src_blk.m_mode == UASTC_MODE_INDEX_SOLID_COLOR) ? unpacked_src_blk.m_solid_color[3] : 255;

			dst.m_base = a;
			dst.m_table = 13;
			dst.m_multiplier = 1;

			memcpy(dst.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

			return;
		}

		uint32_t min_a = 255, max_a = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			min_a = basisu::minimum<uint32_t>(min_a, pSrc_pixels[i].a);
			max_a = basisu::maximum<uint32_t>(max_a, pSrc_pixels[i].a);
		}

		if (min_a == max_a)
		{
			dst.m_base = min_a;
			dst.m_table = 13;
			dst.m_multiplier = 1;

			memcpy(dst.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));
			return;
		}

		const uint32_t table = unpacked_src_blk.m_etc2_hints & 0xF;
		const int multiplier = unpacked_src_blk.m_etc2_hints >> 4;

		assert(multiplier >= 1);

		dst.m_multiplier = multiplier;
		dst.m_table = table;

		const float range = (float)(g_eac_modifier_table[dst.m_table][ETC2_EAC_MAX_VALUE_SELECTOR] - g_eac_modifier_table[dst.m_table][ETC2_EAC_MIN_VALUE_SELECTOR]);
		const int center = (int)roundf(basisu::lerp((float)min_a, (float)max_a, (float)(0 - g_eac_modifier_table[dst.m_table][ETC2_EAC_MIN_VALUE_SELECTOR]) / range));

		dst.m_base = center;

		const int8_t* pTable = &g_eac_modifier_table[dst.m_table][0];

		uint32_t vals[8];
		for (uint32_t j = 0; j < 8; j++)
			vals[j] = clamp255(center + (pTable[j] * multiplier));

		uint64_t sels = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t a = block_pixels[i & 3][i >> 2].a;

			const uint32_t err0 = (basisu::iabs(vals[0] - a) << 3) | 0;
			const uint32_t err1 = (basisu::iabs(vals[1] - a) << 3) | 1;
			const uint32_t err2 = (basisu::iabs(vals[2] - a) << 3) | 2;
			const uint32_t err3 = (basisu::iabs(vals[3] - a) << 3) | 3;
			const uint32_t err4 = (basisu::iabs(vals[4] - a) << 3) | 4;
			const uint32_t err5 = (basisu::iabs(vals[5] - a) << 3) | 5;
			const uint32_t err6 = (basisu::iabs(vals[6] - a) << 3) | 6;
			const uint32_t err7 = (basisu::iabs(vals[7] - a) << 3) | 7;

			const uint32_t min_err = basisu::minimum(basisu::minimum(basisu::minimum(basisu::minimum(basisu::minimum(basisu::minimum(err0, err1, err2), err3), err4), err5), err6), err7);

			const uint64_t best_index = min_err & 7;
			sels |= (best_index << (45 - i * 3));
		}

		dst.set_selector_bits(sels);
	}

	bool transcode_uastc_to_etc2_rgba(const uastc_block& src_blk, void* pDst)
	{
		eac_block& dst_etc2_eac_a8_blk = *static_cast<eac_block*>(pDst);
		decoder_etc_block& dst_etc1_blk = static_cast<decoder_etc_block*>(pDst)[1];

		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		color32 block_pixels[4][4];
		if (unpacked_src_blk.m_mode != UASTC_MODE_INDEX_SOLID_COLOR)
		{
			const bool unpack_srgb = false;
			if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
				return false;
		}

		transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, &dst_etc2_eac_a8_blk);

		transcode_uastc_to_etc1(unpacked_src_blk, block_pixels, &dst_etc1_blk);

		return true;
	}

	static const uint8_t s_uastc5_to_bc1[32] = { 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 1, 1 };
	static const uint8_t s_uastc4_to_bc1[16] = { 0, 0, 0, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 1, 1, 1 };
	static const uint8_t s_uastc3_to_bc1[8] = { 0, 0, 2, 2, 3, 3, 1, 1 };
	static const uint8_t s_uastc2_to_bc1[4] = { 0, 2, 3, 1 };
	static const uint8_t s_uastc1_to_bc1[2] = { 0, 1 };
	const uint8_t* s_uastc_to_bc1_weights[6] = { nullptr, s_uastc1_to_bc1, s_uastc2_to_bc1, s_uastc3_to_bc1, s_uastc4_to_bc1, s_uastc5_to_bc1 };
				
	void encode_bc4(void* pDst, const uint8_t* pPixels, uint32_t stride)
	{
		uint32_t min0_v, max0_v, min1_v, max1_v,min2_v, max2_v, min3_v, max3_v;

		{
			min0_v = max0_v = pPixels[0 * stride];
			min1_v = max1_v = pPixels[1 * stride];
			min2_v = max2_v = pPixels[2 * stride];
			min3_v = max3_v = pPixels[3 * stride];
		}

		{
			uint32_t v0 = pPixels[4 * stride]; min0_v = basisu::minimum(min0_v, v0); max0_v = basisu::maximum(max0_v, v0);
			uint32_t v1 = pPixels[5 * stride]; min1_v = basisu::minimum(min1_v, v1); max1_v = basisu::maximum(max1_v, v1);
			uint32_t v2 = pPixels[6 * stride]; min2_v = basisu::minimum(min2_v, v2); max2_v = basisu::maximum(max2_v, v2);
			uint32_t v3 = pPixels[7 * stride]; min3_v = basisu::minimum(min3_v, v3); max3_v = basisu::maximum(max3_v, v3);
		}

		{
			uint32_t v0 = pPixels[8 * stride]; min0_v = basisu::minimum(min0_v, v0); max0_v = basisu::maximum(max0_v, v0);
			uint32_t v1 = pPixels[9 * stride]; min1_v = basisu::minimum(min1_v, v1); max1_v = basisu::maximum(max1_v, v1);
			uint32_t v2 = pPixels[10 * stride]; min2_v = basisu::minimum(min2_v, v2); max2_v = basisu::maximum(max2_v, v2);
			uint32_t v3 = pPixels[11 * stride]; min3_v = basisu::minimum(min3_v, v3); max3_v = basisu::maximum(max3_v, v3);
		}

		{
			uint32_t v0 = pPixels[12 * stride]; min0_v = basisu::minimum(min0_v, v0); max0_v = basisu::maximum(max0_v, v0);
			uint32_t v1 = pPixels[13 * stride]; min1_v = basisu::minimum(min1_v, v1); max1_v = basisu::maximum(max1_v, v1);
			uint32_t v2 = pPixels[14 * stride]; min2_v = basisu::minimum(min2_v, v2); max2_v = basisu::maximum(max2_v, v2);
			uint32_t v3 = pPixels[15 * stride]; min3_v = basisu::minimum(min3_v, v3); max3_v = basisu::maximum(max3_v, v3);
		}

		const uint32_t min_v = basisu::minimum(min0_v, min1_v, min2_v, min3_v);
		const uint32_t max_v = basisu::maximum(max0_v, max1_v, max2_v, max3_v);

		uint8_t* pDst_bytes = static_cast<uint8_t*>(pDst);
		pDst_bytes[0] = (uint8_t)max_v;
		pDst_bytes[1] = (uint8_t)min_v;

		if (max_v == min_v)
		{
			memset(pDst_bytes + 2, 0, 6);
			return;
		}

		const uint32_t delta = max_v - min_v;

		// min_v is now 0. Compute thresholds between values by scaling max_v. It's x14 because we're adding two x7 scale factors.
		const int t0 = delta * 13;
		const int t1 = delta * 11;
		const int t2 = delta * 9;
		const int t3 = delta * 7;
		const int t4 = delta * 5;
		const int t5 = delta * 3;
		const int t6 = delta * 1;

		// BC4 floors in its divisions, which we compensate for with the 4 bias.
		// This function is optimal for all possible inputs (i.e. it outputs the same results as checking all 8 values and choosing the closest one).
		const int bias = 4 - min_v * 14;

		static const uint32_t s_tran0[8] = { 1U      , 7U      , 6U      , 5U      , 4U      , 3U      , 2U      , 0U };
		static const uint32_t s_tran1[8] = { 1U << 3U, 7U << 3U, 6U << 3U, 5U << 3U, 4U << 3U, 3U << 3U, 2U << 3U, 0U << 3U };
		static const uint32_t s_tran2[8] = { 1U << 6U, 7U << 6U, 6U << 6U, 5U << 6U, 4U << 6U, 3U << 6U, 2U << 6U, 0U << 6U };
		static const uint32_t s_tran3[8] = { 1U << 9U, 7U << 9U, 6U << 9U, 5U << 9U, 4U << 9U, 3U << 9U, 2U << 9U, 0U << 9U };

		uint64_t a0, a1, a2, a3;
		{
			const int v0 = pPixels[0 * stride] * 14 + bias;
			const int v1 = pPixels[1 * stride] * 14 + bias;
			const int v2 = pPixels[2 * stride] * 14 + bias;
			const int v3 = pPixels[3 * stride] * 14 + bias;
			a0 = s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)];
			a1 = s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)];
			a2 = s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)];
			a3 = s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)];
		}

		{
			const int v0 = pPixels[4 * stride] * 14 + bias;
			const int v1 = pPixels[5 * stride] * 14 + bias;
			const int v2 = pPixels[6 * stride] * 14 + bias;
			const int v3 = pPixels[7 * stride] * 14 + bias;
			a0 |= (s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)] << 12U);
			a1 |= (s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)] << 12U);
			a2 |= (s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)] << 12U);
			a3 |= (s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)] << 12U);
		}
		
		{
			const int v0 = pPixels[8 * stride] * 14 + bias;
			const int v1 = pPixels[9 * stride] * 14 + bias;
			const int v2 = pPixels[10 * stride] * 14 + bias;
			const int v3 = pPixels[11 * stride] * 14 + bias;
			a0 |= (((uint64_t)s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)]) << 24U);
			a1 |= (((uint64_t)s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)]) << 24U);
			a2 |= (((uint64_t)s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)]) << 24U);
			a3 |= (((uint64_t)s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)]) << 24U);
		}

		{
			const int v0 = pPixels[12 * stride] * 14 + bias;
			const int v1 = pPixels[13 * stride] * 14 + bias;
			const int v2 = pPixels[14 * stride] * 14 + bias;
			const int v3 = pPixels[15 * stride] * 14 + bias;
			a0 |= (((uint64_t)s_tran0[(v0 >= t0) + (v0 >= t1) + (v0 >= t2) + (v0 >= t3) + (v0 >= t4) + (v0 >= t5) + (v0 >= t6)]) << 36U);
			a1 |= (((uint64_t)s_tran1[(v1 >= t0) + (v1 >= t1) + (v1 >= t2) + (v1 >= t3) + (v1 >= t4) + (v1 >= t5) + (v1 >= t6)]) << 36U);
			a2 |= (((uint64_t)s_tran2[(v2 >= t0) + (v2 >= t1) + (v2 >= t2) + (v2 >= t3) + (v2 >= t4) + (v2 >= t5) + (v2 >= t6)]) << 36U);
			a3 |= (((uint64_t)s_tran3[(v3 >= t0) + (v3 >= t1) + (v3 >= t2) + (v3 >= t3) + (v3 >= t4) + (v3 >= t5) + (v3 >= t6)]) << 36U);
		}

		const uint64_t f = a0 | a1 | a2 | a3;
		
		pDst_bytes[2] = (uint8_t)f;
		pDst_bytes[3] = (uint8_t)(f >> 8U);
		pDst_bytes[4] = (uint8_t)(f >> 16U);
		pDst_bytes[5] = (uint8_t)(f >> 24U);
		pDst_bytes[6] = (uint8_t)(f >> 32U);
		pDst_bytes[7] = (uint8_t)(f >> 40U);
	}

	static void bc1_find_sels(const color32 *pSrc_pixels, uint32_t lr, uint32_t lg, uint32_t lb, uint32_t hr, uint32_t hg, uint32_t hb, uint8_t sels[16])
	{
		uint32_t block_r[4], block_g[4], block_b[4];

		block_r[0] = (lr << 3) | (lr >> 2); block_g[0] = (lg << 2) | (lg >> 4);	block_b[0] = (lb << 3) | (lb >> 2);
		block_r[3] = (hr << 3) | (hr >> 2);	block_g[3] = (hg << 2) | (hg >> 4);	block_b[3] = (hb << 3) | (hb >> 2);
		block_r[1] = (block_r[0] * 2 + block_r[3]) / 3;	block_g[1] = (block_g[0] * 2 + block_g[3]) / 3;	block_b[1] = (block_b[0] * 2 + block_b[3]) / 3;
		block_r[2] = (block_r[3] * 2 + block_r[0]) / 3;	block_g[2] = (block_g[3] * 2 + block_g[0]) / 3;	block_b[2] = (block_b[3] * 2 + block_b[0]) / 3;

		int ar = block_r[3] - block_r[0], ag = block_g[3] - block_g[0], ab = block_b[3] - block_b[0];

		int dots[4];
		for (uint32_t i = 0; i < 4; i++)
			dots[i] = (int)block_r[i] * ar + (int)block_g[i] * ag + (int)block_b[i] * ab;
				
		int t0 = dots[0] + dots[1], t1 = dots[1] + dots[2], t2 = dots[2] + dots[3];

		ar *= 2; ag *= 2; ab *= 2;

		for (uint32_t i = 0; i < 16; i++)
		{
			const int d = pSrc_pixels[i].r * ar + pSrc_pixels[i].g * ag + pSrc_pixels[i].b * ab;
			static const uint8_t s_sels[4] = { 3, 2, 1, 0 };
		
			// Rounding matters here!
			// d <= t0: <=, not <, to the later LS step "sees" a wider range of selectors. It matters for quality.
			sels[i] = s_sels[(d <= t0) + (d < t1) + (d < t2)];
		}
	}

	static inline void bc1_find_sels_2(const color32* pSrc_pixels, uint32_t lr, uint32_t lg, uint32_t lb, uint32_t hr, uint32_t hg, uint32_t hb, uint8_t sels[16])
	{
		uint32_t block_r[4], block_g[4], block_b[4];

		block_r[0] = (lr << 3) | (lr >> 2); block_g[0] = (lg << 2) | (lg >> 4);	block_b[0] = (lb << 3) | (lb >> 2);
		block_r[3] = (hr << 3) | (hr >> 2);	block_g[3] = (hg << 2) | (hg >> 4);	block_b[3] = (hb << 3) | (hb >> 2);
		block_r[1] = (block_r[0] * 2 + block_r[3]) / 3;	block_g[1] = (block_g[0] * 2 + block_g[3]) / 3;	block_b[1] = (block_b[0] * 2 + block_b[3]) / 3;
		block_r[2] = (block_r[3] * 2 + block_r[0]) / 3;	block_g[2] = (block_g[3] * 2 + block_g[0]) / 3;	block_b[2] = (block_b[3] * 2 + block_b[0]) / 3;

		int ar = block_r[3] - block_r[0], ag = block_g[3] - block_g[0], ab = block_b[3] - block_b[0];

		int dots[4];
		for (uint32_t i = 0; i < 4; i++)
			dots[i] = (int)block_r[i] * ar + (int)block_g[i] * ag + (int)block_b[i] * ab;

		int t0 = dots[0] + dots[1], t1 = dots[1] + dots[2], t2 = dots[2] + dots[3];

		ar *= 2; ag *= 2; ab *= 2;

		static const uint8_t s_sels[4] = { 3, 2, 1, 0 };

		for (uint32_t i = 0; i < 16; i += 4)
		{
			const int d0 = pSrc_pixels[i+0].r * ar + pSrc_pixels[i+0].g * ag + pSrc_pixels[i+0].b * ab;
			const int d1 = pSrc_pixels[i+1].r * ar + pSrc_pixels[i+1].g * ag + pSrc_pixels[i+1].b * ab;
			const int d2 = pSrc_pixels[i+2].r * ar + pSrc_pixels[i+2].g * ag + pSrc_pixels[i+2].b * ab;
			const int d3 = pSrc_pixels[i+3].r * ar + pSrc_pixels[i+3].g * ag + pSrc_pixels[i+3].b * ab;

			sels[i+0] = s_sels[(d0 <= t0) + (d0 < t1) + (d0 < t2)];
			sels[i+1] = s_sels[(d1 <= t0) + (d1 < t1) + (d1 < t2)];
			sels[i+2] = s_sels[(d2 <= t0) + (d2 < t1) + (d2 < t2)];
			sels[i+3] = s_sels[(d3 <= t0) + (d3 < t1) + (d3 < t2)];
		}
	}
				
	static bool compute_least_squares_endpoints_rgb(const color32* pColors, const uint8_t* pSelectors, vec3F* pXl, vec3F* pXh)
	{
		// Derived from bc7enc16's LS function.
		// Least squares using normal equations: http://www.cs.cornell.edu/~bindel/class/cs3220-s12/notes/lec10.pdf 
		// I did this in matrix form first, expanded out all the ops, then optimized it a bit.
		uint32_t uq00_r = 0, uq10_r = 0, ut_r = 0, uq00_g = 0, uq10_g = 0, ut_g = 0, uq00_b = 0, uq10_b = 0, ut_b = 0;

		// This table is: 9 * (w * w), 9 * ((1.0f - w) * w), 9 * ((1.0f - w) * (1.0f - w))
		// where w is [0,1/3,2/3,1]. 9 is the perfect multiplier.
		static const uint32_t s_weight_vals[4] = { 0x000009, 0x010204, 0x040201, 0x090000 };

		uint32_t weight_accum = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t r = pColors[i].c[0], g = pColors[i].c[1], b = pColors[i].c[2];
			const uint32_t sel = pSelectors[i];
			ut_r += r;
			ut_g += g;
			ut_b += b;
			weight_accum += s_weight_vals[sel];
			uq00_r += sel * r;
			uq00_g += sel * g;
			uq00_b += sel * b;
		}

		float q00_r = (float)uq00_r, q10_r = (float)uq10_r, t_r = (float)ut_r;
		float q00_g = (float)uq00_g, q10_g = (float)uq10_g, t_g = (float)ut_g;
		float q00_b = (float)uq00_b, q10_b = (float)uq10_b, t_b = (float)ut_b;

		q10_r = t_r * 3.0f - q00_r;
		q10_g = t_g * 3.0f - q00_g;
		q10_b = t_b * 3.0f - q00_b;

		float z00 = (float)((weight_accum >> 16) & 0xFF);
		float z10 = (float)((weight_accum >> 8) & 0xFF);
		float z11 = (float)(weight_accum & 0xFF);
		float z01 = z10;

		float det = z00 * z11 - z01 * z10;
		if (fabs(det) < 1e-8f)
			return false;

		det = 3.0f / det;

		float iz00, iz01, iz10, iz11;
		iz00 = z11 * det;
		iz01 = -z01 * det;
		iz10 = -z10 * det;
		iz11 = z00 * det;

		pXl->c[0] = iz00 * q00_r + iz01 * q10_r; pXh->c[0] = iz10 * q00_r + iz11 * q10_r;
		pXl->c[1] = iz00 * q00_g + iz01 * q10_g; pXh->c[1] = iz10 * q00_g + iz11 * q10_g;
		pXl->c[2] = iz00 * q00_b + iz01 * q10_b; pXh->c[2] = iz10 * q00_b + iz11 * q10_b;

		// Check and fix channel singularities - might not be needed, but is in UASTC's encoder.
		for (uint32_t c = 0; c < 3; c++)
		{
			if ((pXl->c[c] < 0.0f) || (pXh->c[c] > 255.0f))
			{
				uint32_t lo_v = UINT32_MAX, hi_v = 0;
				for (uint32_t i = 0; i < 16; i++)
				{
					lo_v = basisu::minimumu(lo_v, pColors[i].c[c]);
					hi_v = basisu::maximumu(hi_v, pColors[i].c[c]);
				}

				if (lo_v == hi_v)
				{
					pXl->c[c] = (float)lo_v;
					pXh->c[c] = (float)hi_v;
				}
			}
		}

		return true;
	}

	void encode_bc1_solid_block(void* pDst, uint32_t fr, uint32_t fg, uint32_t fb) 
	{
		dxt1_block* pDst_block = static_cast<dxt1_block*>(pDst);

		uint32_t mask = 0xAA;
		uint32_t max16 = (g_bc1_match5_equals_1[fr].m_hi << 11) | (g_bc1_match6_equals_1[fg].m_hi << 5) | g_bc1_match5_equals_1[fb].m_hi;
		uint32_t min16 = (g_bc1_match5_equals_1[fr].m_lo << 11) | (g_bc1_match6_equals_1[fg].m_lo << 5) | g_bc1_match5_equals_1[fb].m_lo;

		if (min16 == max16)
		{
			// Always forbid 3 color blocks
			// This is to guarantee that BC3 blocks never use punchthrough alpha (3 color) mode, which isn't supported on some (all?) GPU's.
			mask = 0;

			// Make l > h
			if (min16 > 0)
				min16--;
			else
			{
				// l = h = 0
				assert(min16 == max16 && max16 == 0);

				max16 = 1;
				min16 = 0;
				mask = 0x55;
			}

			assert(max16 > min16);
		}

		if (max16 < min16)
		{
			std::swap(max16, min16);
			mask ^= 0x55;
		}

		pDst_block->set_low_color(static_cast<uint16_t>(max16));
		pDst_block->set_high_color(static_cast<uint16_t>(min16));
		pDst_block->m_selectors[0] = static_cast<uint8_t>(mask);
		pDst_block->m_selectors[1] = static_cast<uint8_t>(mask);
		pDst_block->m_selectors[2] = static_cast<uint8_t>(mask);
		pDst_block->m_selectors[3] = static_cast<uint8_t>(mask);
	}

	static inline uint8_t to_5(uint32_t v) { v = v * 31 + 128; return (uint8_t)((v + (v >> 8)) >> 8); }
	static inline uint8_t to_6(uint32_t v) { v = v * 63 + 128; return (uint8_t)((v + (v >> 8)) >> 8); }

	// Good references: squish library, stb_dxt.
	void encode_bc1(void* pDst, const uint8_t* pPixels, uint32_t flags)
	{
		const color32* pSrc_pixels = (const color32*)pPixels;
		dxt1_block* pDst_block = static_cast<dxt1_block*>(pDst);
		
		int avg_r = -1, avg_g = 0, avg_b = 0;
		int lr = 0, lg = 0, lb = 0, hr = 0, hg = 0, hb = 0;
		uint8_t sels[16];
		
		const bool use_sels = (flags & cEncodeBC1UseSelectors) != 0;
		if (use_sels)
		{
			// Caller is jamming in their own selectors for us to try.
			const uint32_t s = pDst_block->m_selectors[0] | (pDst_block->m_selectors[1] << 8) | (pDst_block->m_selectors[2] << 16) | (pDst_block->m_selectors[3] << 24);
			
			static const uint8_t s_sel_tran[4] = { 0, 3, 1, 2 };
			
			for (uint32_t i = 0; i < 16; i++)
				sels[i] = s_sel_tran[(s >> (i * 2)) & 3];
		}
		else
		{
			const uint32_t fr = pSrc_pixels[0].r, fg = pSrc_pixels[0].g, fb = pSrc_pixels[0].b;

			uint32_t j;
			for (j = 1; j < 16; j++)
				if ((pSrc_pixels[j].r != fr) || (pSrc_pixels[j].g != fg) || (pSrc_pixels[j].b != fb))
					break;
						
			if (j == 16)
			{
				encode_bc1_solid_block(pDst, fr, fg, fb);
				return;
			}
			
			// Select 2 colors along the principle axis. (There must be a faster/simpler way.)
			int total_r = fr, total_g = fg, total_b = fb;
			int max_r = fr, max_g = fg, max_b = fb;
			int min_r = fr, min_g = fg, min_b = fb;
			for (uint32_t i = 1; i < 16; i++)
			{
				const int r = pSrc_pixels[i].r, g = pSrc_pixels[i].g, b = pSrc_pixels[i].b;
				max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
				min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
				total_r += r; total_g += g; total_b += b;
			}

			avg_r = (total_r + 8) >> 4;
			avg_g = (total_g + 8) >> 4;
			avg_b = (total_b + 8) >> 4;

			int icov[6] = { 0, 0, 0, 0, 0, 0 };
			for (uint32_t i = 0; i < 16; i++)
			{
				int r = (int)pSrc_pixels[i].r - avg_r;
				int g = (int)pSrc_pixels[i].g - avg_g;
				int b = (int)pSrc_pixels[i].b - avg_b;
				icov[0] += r * r;
				icov[1] += r * g;
				icov[2] += r * b;
				icov[3] += g * g;
				icov[4] += g * b;
				icov[5] += b * b;
			}

			float cov[6];
			for (uint32_t i = 0; i < 6; i++)
				cov[i] = static_cast<float>(icov[i])* (1.0f / 255.0f);
			
#if 0
			// Seems silly to use full PCA to choose 2 colors. The diff in avg. PSNR between using PCA vs. not is small (~.025 difference).
			// TODO: Try 2 or 3 different normalized diagonal vectors, choose the one that results in the largest dot delta
			int saxis_r = max_r - min_r;
			int saxis_g = max_g - min_g;
			int saxis_b = max_b - min_b;
#else
			float xr = (float)(max_r - min_r);
			float xg = (float)(max_g - min_g);
			float xb = (float)(max_b - min_b);
			//float xr = (float)(max_r - avg_r); // max-avg is nearly the same, and doesn't require computing min's
			//float xg = (float)(max_g - avg_g);
			//float xb = (float)(max_b - avg_b);
			for (uint32_t power_iter = 0; power_iter < 4; power_iter++)
			{
				float r = xr * cov[0] + xg * cov[1] + xb * cov[2];
				float g = xr * cov[1] + xg * cov[3] + xb * cov[4];
				float b = xr * cov[2] + xg * cov[4] + xb * cov[5];
				xr = r; xg = g; xb = b;
			}

			float k = basisu::maximum(fabsf(xr), fabsf(xg), fabsf(xb));
			int saxis_r = 306, saxis_g = 601, saxis_b = 117;
			if (k >= 2)
			{
				float m = 1024.0f / k;
				saxis_r = (int)(xr * m);
				saxis_g = (int)(xg * m);
				saxis_b = (int)(xb * m);
			}
#endif
			
			int low_dot = INT_MAX, high_dot = INT_MIN, low_c = 0, high_c = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				int dot = pSrc_pixels[i].r * saxis_r + pSrc_pixels[i].g * saxis_g + pSrc_pixels[i].b * saxis_b;
				if (dot < low_dot)
				{
					low_dot = dot;
					low_c = i;
				}
				if (dot > high_dot)
				{
					high_dot = dot;
					high_c = i;
				}
			}

			lr = to_5(pSrc_pixels[low_c].r);
			lg = to_6(pSrc_pixels[low_c].g);
			lb = to_5(pSrc_pixels[low_c].b);

			hr = to_5(pSrc_pixels[high_c].r);
			hg = to_6(pSrc_pixels[high_c].g);
			hb = to_5(pSrc_pixels[high_c].b);
						
			bc1_find_sels(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		} // if (use_sels)

		const uint32_t total_ls_passes = (flags & cEncodeBC1HigherQuality) ? 3 : (flags & cEncodeBC1HighQuality ? 2 : 1);
		for (uint32_t ls_pass = 0; ls_pass < total_ls_passes; ls_pass++)
		{
			// This is where the real magic happens. We have an array of candidate selectors, so let's use least squares to compute the optimal low/high endpoint colors.
			vec3F xl, xh;
			if (!compute_least_squares_endpoints_rgb(pSrc_pixels, sels, &xl, &xh))
			{
				if (avg_r < 0)
				{
					int total_r = 0, total_g = 0, total_b = 0;
					for (uint32_t i = 0; i < 16; i++)
					{
						total_r += pSrc_pixels[i].r;
						total_g += pSrc_pixels[i].g;
						total_b += pSrc_pixels[i].b;
					}

					avg_r = (total_r + 8) >> 4;
					avg_g = (total_g + 8) >> 4;
					avg_b = (total_b + 8) >> 4;
				}

				// All selectors equal - treat it as a solid block which should always be equal or better.
				lr = g_bc1_match5_equals_1[avg_r].m_hi;
				lg = g_bc1_match6_equals_1[avg_g].m_hi;
				lb = g_bc1_match5_equals_1[avg_b].m_hi;

				hr = g_bc1_match5_equals_1[avg_r].m_lo;
				hg = g_bc1_match6_equals_1[avg_g].m_lo;
				hb = g_bc1_match5_equals_1[avg_b].m_lo;

				// In high/higher quality mode, let it try again in case the optimal tables have caused the sels to diverge.
			}
			else
			{
				lr = basisu::clamp((int)((xl.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				lg = basisu::clamp((int)((xl.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				lb = basisu::clamp((int)((xl.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);

				hr = basisu::clamp((int)((xh.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				hg = basisu::clamp((int)((xh.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				hb = basisu::clamp((int)((xh.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);
			}
									
			bc1_find_sels(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		}

		uint32_t lc16 = dxt1_block::pack_unscaled_color(lr, lg, lb);
		uint32_t hc16 = dxt1_block::pack_unscaled_color(hr, hg, hb);
				
		// Always forbid 3 color blocks
		if (lc16 == hc16)
		{
			uint8_t mask = 0;

			// Make l > h
			if (hc16 > 0)
				hc16--;
			else
			{
				// lc16 = hc16 = 0
				assert(lc16 == hc16 && hc16 == 0);

				hc16 = 0;
				lc16 = 1;
				mask = 0x55; // select hc16
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color(static_cast<uint16_t>(lc16));
			pDst_block->set_high_color(static_cast<uint16_t>(hc16));

			pDst_block->m_selectors[0] = mask;
			pDst_block->m_selectors[1] = mask;
			pDst_block->m_selectors[2] = mask;
			pDst_block->m_selectors[3] = mask;
		}
		else
		{
			uint8_t invert_mask = 0;
			if (lc16 < hc16)
			{
				std::swap(lc16, hc16);
				invert_mask = 0x55;
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color((uint16_t)lc16);
			pDst_block->set_high_color((uint16_t)hc16);

			uint32_t packed_sels = 0;
			static const uint8_t s_sel_trans[4] = { 0, 2, 3, 1 };
			for (uint32_t i = 0; i < 16; i++)
				packed_sels |= ((uint32_t)s_sel_trans[sels[i]] << (i * 2));

			pDst_block->m_selectors[0] = (uint8_t)packed_sels ^ invert_mask;
			pDst_block->m_selectors[1] = (uint8_t)(packed_sels >> 8) ^ invert_mask;
			pDst_block->m_selectors[2] = (uint8_t)(packed_sels >> 16) ^ invert_mask;
			pDst_block->m_selectors[3] = (uint8_t)(packed_sels >> 24) ^ invert_mask;
		}
	}
		
	void encode_bc1_alt(void* pDst, const uint8_t* pPixels, uint32_t flags)
	{
		const color32* pSrc_pixels = (const color32*)pPixels;
		dxt1_block* pDst_block = static_cast<dxt1_block*>(pDst);

		int avg_r = -1, avg_g = 0, avg_b = 0;
		int lr = 0, lg = 0, lb = 0, hr = 0, hg = 0, hb = 0;
		uint8_t sels[16];

		const bool use_sels = (flags & cEncodeBC1UseSelectors) != 0;
		if (use_sels)
		{
			// Caller is jamming in their own selectors for us to try.
			const uint32_t s = pDst_block->m_selectors[0] | (pDst_block->m_selectors[1] << 8) | (pDst_block->m_selectors[2] << 16) | (pDst_block->m_selectors[3] << 24);

			static const uint8_t s_sel_tran[4] = { 0, 3, 1, 2 };

			for (uint32_t i = 0; i < 16; i++)
				sels[i] = s_sel_tran[(s >> (i * 2)) & 3];
		}
		else
		{
			const uint32_t fr = pSrc_pixels[0].r, fg = pSrc_pixels[0].g, fb = pSrc_pixels[0].b;

			uint32_t j;
			for (j = 1; j < 16; j++)
				if ((pSrc_pixels[j].r != fr) || (pSrc_pixels[j].g != fg) || (pSrc_pixels[j].b != fb))
					break;

			if (j == 16)
			{
				encode_bc1_solid_block(pDst, fr, fg, fb);
				return;
			}

			// Select 2 colors along the principle axis. (There must be a faster/simpler way.)
			int total_r = fr, total_g = fg, total_b = fb;
			int max_r = fr, max_g = fg, max_b = fb;
			int min_r = fr, min_g = fg, min_b = fb;
			uint32_t grayscale_flag = (fr == fg) && (fr == fb);
			for (uint32_t i = 1; i < 16; i++)
			{
				const int r = pSrc_pixels[i].r, g = pSrc_pixels[i].g, b = pSrc_pixels[i].b;
				grayscale_flag &= ((r == g) && (r == b));
				max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
				min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
				total_r += r; total_g += g; total_b += b;
			}
						
			if (grayscale_flag) 
			{
				// Grayscale blocks are a common enough case to specialize.
				if ((max_r - min_r) < 2)
				{
					lr = lb = hr = hb = to_5(fr);
					lg = hg = to_6(fr);
				}
				else
				{
					lr = lb = to_5(min_r);
					lg = to_6(min_r);

					hr = hb = to_5(max_r);
					hg = to_6(max_r);
				}
			}
			else
			{
				avg_r = (total_r + 8) >> 4;
				avg_g = (total_g + 8) >> 4;
				avg_b = (total_b + 8) >> 4;

				// Find the shortest vector from a AABB corner to the block's average color.
				// This is to help avoid outliers.

				uint32_t dist[3][2];
				dist[0][0] = basisu::square(min_r - avg_r) << 3; dist[0][1] = basisu::square(max_r - avg_r) << 3;
				dist[1][0] = basisu::square(min_g - avg_g) << 3; dist[1][1] = basisu::square(max_g - avg_g) << 3;
				dist[2][0] = basisu::square(min_b - avg_b) << 3; dist[2][1] = basisu::square(max_b - avg_b) << 3;

				uint32_t min_d0 = (dist[0][0] + dist[1][0] + dist[2][0]);
				uint32_t d4 = (dist[0][0] + dist[1][0] + dist[2][1]) | 4;
				min_d0 = basisu::minimum(min_d0, d4);

				uint32_t min_d1 = (dist[0][1] + dist[1][0] + dist[2][0]) | 1;
				uint32_t d5 = (dist[0][1] + dist[1][0] + dist[2][1]) | 5;
				min_d1 = basisu::minimum(min_d1, d5);

				uint32_t d2 = (dist[0][0] + dist[1][1] + dist[2][0]) | 2;
				min_d0 = basisu::minimum(min_d0, d2);

				uint32_t d3 = (dist[0][1] + dist[1][1] + dist[2][0]) | 3;
				min_d1 = basisu::minimum(min_d1, d3);

				uint32_t d6 = (dist[0][0] + dist[1][1] + dist[2][1]) | 6;
				min_d0 = basisu::minimum(min_d0, d6);

				uint32_t d7 = (dist[0][1] + dist[1][1] + dist[2][1]) | 7;
				min_d1 = basisu::minimum(min_d1, d7);

				uint32_t min_d = basisu::minimum(min_d0, min_d1);
				uint32_t best_i = min_d & 7;

				int delta_r = (best_i & 1) ? (max_r - avg_r) : (avg_r - min_r);
				int delta_g = (best_i & 2) ? (max_g - avg_g) : (avg_g - min_g);
				int delta_b = (best_i & 4) ? (max_b - avg_b) : (avg_b - min_b);

				// Note: if delta_r/g/b==0, we actually want to choose a single color, so the block average color optimization kicks in.
				uint32_t low_c = 0, high_c = 0;
				if ((delta_r | delta_g | delta_b) != 0)
				{
					// Now we have a smaller AABB going from the block's average color to a cornerpoint of the larger AABB.
					// Project all pixels colors along the 4 vectors going from a smaller AABB cornerpoint to the opposite cornerpoint, find largest projection.
					// One of these vectors will be a decent approximation of the block's PCA.
					const int saxis0_r = delta_r, saxis0_g = delta_g, saxis0_b = delta_b;

					int low_dot0 = INT_MAX, high_dot0 = INT_MIN;
					int low_dot1 = INT_MAX, high_dot1 = INT_MIN;
					int low_dot2 = INT_MAX, high_dot2 = INT_MIN;
					int low_dot3 = INT_MAX, high_dot3 = INT_MIN;

					//int low_c0, low_c1, low_c2, low_c3;
					//int high_c0, high_c1, high_c2, high_c3;

					for (uint32_t i = 0; i < 16; i++)
					{
						const int dotx = pSrc_pixels[i].r * saxis0_r;
						const int doty = pSrc_pixels[i].g * saxis0_g;
						const int dotz = pSrc_pixels[i].b * saxis0_b;

						const int dot0 = ((dotz + dotx + doty) << 4) + i;
						const int dot1 = ((dotz - dotx - doty) << 4) + i;
						const int dot2 = ((dotz - dotx + doty) << 4) + i;
						const int dot3 = ((dotz + dotx - doty) << 4) + i;

						if (dot0 < low_dot0)
						{
							low_dot0 = dot0;
							//low_c0 = i;
						}
						if ((dot0 ^ 15) > high_dot0)
						{
							high_dot0 = dot0 ^ 15;
							//high_c0 = i;
						}

						if (dot1 < low_dot1)
						{
							low_dot1 = dot1;
							//low_c1 = i;
						}
						if ((dot1 ^ 15) > high_dot1)
						{
							high_dot1 = dot1 ^ 15;
							//high_c1 = i;
						}

						if (dot2 < low_dot2)
						{
							low_dot2 = dot2;
							//low_c2 = i;
						}
						if ((dot2 ^ 15) > high_dot2)
						{
							high_dot2 = dot2 ^ 15;
							//high_c2 = i;
						}

						if (dot3 < low_dot3)
						{
							low_dot3 = dot3;
							//low_c3 = i;
						}
						if ((dot3 ^ 15) > high_dot3)
						{
							high_dot3 = dot3 ^ 15;
							//high_c3 = i;
						}
					}

					low_c = low_dot0 & 15;
					high_c = ~high_dot0 & 15;
					uint32_t r = (high_dot0 & ~15) - (low_dot0 & ~15);

					uint32_t tr = (high_dot1 & ~15) - (low_dot1 & ~15);
					if (tr > r) {
						low_c = low_dot1 & 15;
						high_c = ~high_dot1 & 15;
						r = tr;
					}

					tr = (high_dot2 & ~15) - (low_dot2 & ~15);
					if (tr > r) {
						low_c = low_dot2 & 15;
						high_c = ~high_dot2 & 15;
						r = tr;
					}

					tr = (high_dot3 & ~15) - (low_dot3 & ~15);
					if (tr > r) {
						low_c = low_dot3 & 15;
						high_c = ~high_dot3 & 15;
					}
				}

				lr = to_5(pSrc_pixels[low_c].r);
				lg = to_6(pSrc_pixels[low_c].g);
				lb = to_5(pSrc_pixels[low_c].b);

				hr = to_5(pSrc_pixels[high_c].r);
				hg = to_6(pSrc_pixels[high_c].g);
				hb = to_5(pSrc_pixels[high_c].b);
			}

			bc1_find_sels_2(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		} // if (use_sels)

		const uint32_t total_ls_passes = (flags & cEncodeBC1HigherQuality) ? 3 : (flags & cEncodeBC1HighQuality ? 2 : 1);
		for (uint32_t ls_pass = 0; ls_pass < total_ls_passes; ls_pass++)
		{
			int prev_lr = lr, prev_lg = lg, prev_lb = lb, prev_hr = hr, prev_hg = hg, prev_hb = hb;

			// This is where the real magic happens. We have an array of candidate selectors, so let's use least squares to compute the optimal low/high endpoint colors.
			vec3F xl, xh;
			if (!compute_least_squares_endpoints_rgb(pSrc_pixels, sels, &xl, &xh))
			{
				if (avg_r < 0)
				{
					int total_r = 0, total_g = 0, total_b = 0;
					for (uint32_t i = 0; i < 16; i++)
					{
						total_r += pSrc_pixels[i].r;
						total_g += pSrc_pixels[i].g;
						total_b += pSrc_pixels[i].b;
					}

					avg_r = (total_r + 8) >> 4;
					avg_g = (total_g + 8) >> 4;
					avg_b = (total_b + 8) >> 4;
				}

				// All selectors equal - treat it as a solid block which should always be equal or better.
				lr = g_bc1_match5_equals_1[avg_r].m_hi;
				lg = g_bc1_match6_equals_1[avg_g].m_hi;
				lb = g_bc1_match5_equals_1[avg_b].m_hi;

				hr = g_bc1_match5_equals_1[avg_r].m_lo;
				hg = g_bc1_match6_equals_1[avg_g].m_lo;
				hb = g_bc1_match5_equals_1[avg_b].m_lo;

				// In high/higher quality mode, let it try again in case the optimal tables have caused the sels to diverge.
			}
			else
			{
				lr = basisu::clamp((int)((xl.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				lg = basisu::clamp((int)((xl.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				lb = basisu::clamp((int)((xl.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);

				hr = basisu::clamp((int)((xh.c[0]) * (31.0f / 255.0f) + .5f), 0, 31);
				hg = basisu::clamp((int)((xh.c[1]) * (63.0f / 255.0f) + .5f), 0, 63);
				hb = basisu::clamp((int)((xh.c[2]) * (31.0f / 255.0f) + .5f), 0, 31);
			}

			if ((prev_lr == lr) && (prev_lg == lg) && (prev_lb == lb) && (prev_hr == hr) && (prev_hg == hg) && (prev_hb == hb))
				break;

			bc1_find_sels_2(pSrc_pixels, lr, lg, lb, hr, hg, hb, sels);
		}

		uint32_t lc16 = dxt1_block::pack_unscaled_color(lr, lg, lb);
		uint32_t hc16 = dxt1_block::pack_unscaled_color(hr, hg, hb);

		// Always forbid 3 color blocks
		if (lc16 == hc16)
		{
			uint8_t mask = 0;

			// Make l > h
			if (hc16 > 0)
				hc16--;
			else
			{
				// lc16 = hc16 = 0
				assert(lc16 == hc16 && hc16 == 0);

				hc16 = 0;
				lc16 = 1;
				mask = 0x55; // select hc16
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color(static_cast<uint16_t>(lc16));
			pDst_block->set_high_color(static_cast<uint16_t>(hc16));

			pDst_block->m_selectors[0] = mask;
			pDst_block->m_selectors[1] = mask;
			pDst_block->m_selectors[2] = mask;
			pDst_block->m_selectors[3] = mask;
		}
		else
		{
			uint8_t invert_mask = 0;
			if (lc16 < hc16)
			{
				std::swap(lc16, hc16);
				invert_mask = 0x55;
			}

			assert(lc16 > hc16);
			pDst_block->set_low_color((uint16_t)lc16);
			pDst_block->set_high_color((uint16_t)hc16);

			uint32_t packed_sels = 0;
			static const uint8_t s_sel_trans[4] = { 0, 2, 3, 1 };
			for (uint32_t i = 0; i < 16; i++)
				packed_sels |= ((uint32_t)s_sel_trans[sels[i]] << (i * 2));

			pDst_block->m_selectors[0] = (uint8_t)packed_sels ^ invert_mask;
			pDst_block->m_selectors[1] = (uint8_t)(packed_sels >> 8) ^ invert_mask;
			pDst_block->m_selectors[2] = (uint8_t)(packed_sels >> 16) ^ invert_mask;
			pDst_block->m_selectors[3] = (uint8_t)(packed_sels >> 24) ^ invert_mask;
		}
	}

	// Scale the UASTC first subset endpoints and first plane's weight indices directly to BC1's - fastest.
	void transcode_uastc_to_bc1_hint0(const unpacked_uastc_block& unpacked_src_blk, void* pDst)
	{
		const uint32_t mode = unpacked_src_blk.m_mode;
		const astc_block_desc& astc_blk = unpacked_src_blk.m_astc;

		dxt1_block& b = *static_cast<dxt1_block*>(pDst);

		const uint32_t endpoint_range = g_uastc_mode_endpoint_ranges[mode];

		const uint32_t total_comps = g_uastc_mode_comps[mode];

		if (total_comps == 2)
		{
			const uint32_t l = g_astc_unquant[endpoint_range][astc_blk.m_endpoints[0]].m_unquant;
			const uint32_t h = g_astc_unquant[endpoint_range][astc_blk.m_endpoints[1]].m_unquant;

			b.set_low_color(dxt1_block::pack_color(color32(l, l, l, 255), true, 127));
			b.set_high_color(dxt1_block::pack_color(color32(h, h, h, 255), true, 127));
		}
		else
		{
			b.set_low_color(dxt1_block::pack_color(
				color32(g_astc_unquant[endpoint_range][astc_blk.m_endpoints[0]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[2]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[4]].m_unquant,
					255), true, 127)
			);

			b.set_high_color(dxt1_block::pack_color(
				color32(g_astc_unquant[endpoint_range][astc_blk.m_endpoints[1]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[3]].m_unquant,
					g_astc_unquant[endpoint_range][astc_blk.m_endpoints[5]].m_unquant,
					255), true, 127)
			);
		}

		if (b.get_low_color() == b.get_high_color())
		{
			// Always forbid 3 color blocks
			uint16_t lc16 = (uint16_t)b.get_low_color();
			uint16_t hc16 = (uint16_t)b.get_high_color();
			
			uint8_t mask = 0;

			// Make l > h
			if (hc16 > 0)
				hc16--;
			else
			{
				// lc16 = hc16 = 0
				assert(lc16 == hc16 && hc16 == 0);

				hc16 = 0;
				lc16 = 1;
				mask = 0x55; // select hc16
			}

			assert(lc16 > hc16);
			b.set_low_color(static_cast<uint16_t>(lc16));
			b.set_high_color(static_cast<uint16_t>(hc16));

			b.m_selectors[0] = mask;
			b.m_selectors[1] = mask;
			b.m_selectors[2] = mask;
			b.m_selectors[3] = mask;
		}
		else
		{
			bool invert = false;
			if (b.get_low_color() < b.get_high_color())
			{
				std::swap(b.m_low_color[0], b.m_high_color[0]);
				std::swap(b.m_low_color[1], b.m_high_color[1]);
				invert = true;
			}

			const uint8_t* pTran = s_uastc_to_bc1_weights[g_uastc_mode_weight_bits[mode]];

			const uint32_t plane_shift = g_uastc_mode_planes[mode] - 1;

			uint32_t sels = 0;
			for (int i = 15; i >= 0; --i)
			{
				uint32_t s = pTran[astc_blk.m_weights[i << plane_shift]];

				if (invert)
					s ^= 1;

				sels = (sels << 2) | s;
			}
			b.m_selectors[0] = sels & 0xFF;
			b.m_selectors[1] = (sels >> 8) & 0xFF;
			b.m_selectors[2] = (sels >> 16) & 0xFF;
			b.m_selectors[3] = (sels >> 24) & 0xFF;
		}
	}

	// Scale the UASTC first plane's weight indices to BC1, use 1 or 2 least squares passes to compute endpoints - no PCA needed.
	void transcode_uastc_to_bc1_hint1(const unpacked_uastc_block& unpacked_src_blk, const color32 block_pixels[4][4], void* pDst, bool high_quality)
	{
		const uint32_t mode = unpacked_src_blk.m_mode;

		const astc_block_desc& astc_blk = unpacked_src_blk.m_astc;

		dxt1_block& b = *static_cast<dxt1_block*>(pDst);

		b.set_low_color(1);
		b.set_high_color(0);

		const uint8_t* pTran = s_uastc_to_bc1_weights[g_uastc_mode_weight_bits[mode]];

		const uint32_t plane_shift = g_uastc_mode_planes[mode] - 1;

		uint32_t sels = 0;
		for (int i = 15; i >= 0; --i)
		{
			sels <<= 2;
			sels |= pTran[astc_blk.m_weights[i << plane_shift]];
		}

		b.m_selectors[0] = sels & 0xFF;
		b.m_selectors[1] = (sels >> 8) & 0xFF;
		b.m_selectors[2] = (sels >> 16) & 0xFF;
		b.m_selectors[3] = (sels >> 24) & 0xFF;

		encode_bc1(&b, (const uint8_t*)&block_pixels[0][0].c[0], (high_quality ? cEncodeBC1HighQuality : 0) | cEncodeBC1UseSelectors);
	}

	bool transcode_uastc_to_bc1(const uastc_block& src_blk, void* pDst, bool high_quality)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			encode_bc1_solid_block(pDst, unpacked_src_blk.m_solid_color.r, unpacked_src_blk.m_solid_color.g, unpacked_src_blk.m_solid_color.b);
			return true;
		}

		if ((!high_quality) && (unpacked_src_blk.m_bc1_hint0))
			transcode_uastc_to_bc1_hint0(unpacked_src_blk, pDst);
		else
		{
			color32 block_pixels[4][4];
			const bool unpack_srgb = false;
			if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
				return false;

			if (unpacked_src_blk.m_bc1_hint1)
				transcode_uastc_to_bc1_hint1(unpacked_src_blk, block_pixels, pDst, high_quality);
			else
				encode_bc1(pDst, &block_pixels[0][0].r, high_quality ? cEncodeBC1HighQuality : 0);
		}

		return true;
	}

	static void write_bc4_solid_block(uint8_t* pDst, uint32_t a)
	{
		pDst[0] = (uint8_t)a;
		pDst[1] = (uint8_t)a;
		memset(pDst + 2, 0, 6);
	}

	bool transcode_uastc_to_bc3(const uastc_block& src_blk, void* pDst, bool high_quality)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		void* pBC4_block = pDst;
		dxt1_block* pBC1_block = &static_cast<dxt1_block*>(pDst)[1];

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block), unpacked_src_blk.m_solid_color.a);
			encode_bc1_solid_block(pBC1_block, unpacked_src_blk.m_solid_color.r, unpacked_src_blk.m_solid_color.g, unpacked_src_blk.m_solid_color.b);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		basist::encode_bc4(pBC4_block, &block_pixels[0][0].a, sizeof(color32));

		if ((!high_quality) && (unpacked_src_blk.m_bc1_hint0))
			transcode_uastc_to_bc1_hint0(unpacked_src_blk, pBC1_block);
		else
		{
			if (unpacked_src_blk.m_bc1_hint1)
				transcode_uastc_to_bc1_hint1(unpacked_src_blk, block_pixels, pBC1_block, high_quality);
			else
				encode_bc1(pBC1_block, &block_pixels[0][0].r, high_quality ? cEncodeBC1HighQuality : 0);
		}

		return true;
	}

	bool transcode_uastc_to_bc4(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0)
	{
		BASISU_NOTE_UNUSED(high_quality);

		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		void* pBC4_block = pDst;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block), unpacked_src_blk.m_solid_color.c[chan0]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		basist::encode_bc4(pBC4_block, &block_pixels[0][0].c[chan0], sizeof(color32));

		return true;
	}

	bool transcode_uastc_to_bc5(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0, uint32_t chan1)
	{
		BASISU_NOTE_UNUSED(high_quality);

		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		void* pBC4_block0 = pDst;
		void* pBC4_block1 = (uint8_t*)pDst + 8;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block0), unpacked_src_blk.m_solid_color.c[chan0]);
			write_bc4_solid_block(static_cast<uint8_t*>(pBC4_block1), unpacked_src_blk.m_solid_color.c[chan1]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		basist::encode_bc4(pBC4_block0, &block_pixels[0][0].c[chan0], sizeof(color32));
		basist::encode_bc4(pBC4_block1, &block_pixels[0][0].c[chan1], sizeof(color32));

		return true;
	}

	static const uint8_t s_etc2_eac_bit_ofs[16] = { 45, 33, 21, 9, 42, 30, 18, 6, 39, 27, 15, 3,	36, 24, 12,	0 };

	static void pack_eac_solid_block(eac_block& blk, uint32_t a)
	{
		blk.m_base = static_cast<uint8_t>(a);
		blk.m_table = 13;
		blk.m_multiplier = 0;
				
		memcpy(blk.m_selectors, g_etc2_eac_a8_sel4, sizeof(g_etc2_eac_a8_sel4));

		return;
	}

	// Only checks 4 tables.
	static void pack_eac(eac_block& blk, const uint8_t* pPixels, uint32_t stride)
	{
		uint32_t min_alpha = 255, max_alpha = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t a = pPixels[i * stride];
			if (a < min_alpha) min_alpha = a;
			if (a > max_alpha) max_alpha = a;
		}

		if (min_alpha == max_alpha)
		{
			pack_eac_solid_block(blk, min_alpha);
			return;
		}

		const uint32_t alpha_range = max_alpha - min_alpha;

		const uint32_t SINGLE_TABLE_THRESH = 5;
		if (alpha_range <= SINGLE_TABLE_THRESH)
		{
			// If alpha_range <= 5 table 13 is lossless
			int base = clamp255((int)max_alpha - 2);

			blk.m_base = base;
			blk.m_multiplier = 1;
			blk.m_table = 13;

			base -= 3;

			uint64_t packed_sels = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				const int a = pPixels[i * stride];

				static const uint8_t s_sels[6] = { 2, 1, 0, 4, 5, 6 };

				int sel = a - base;
				assert(sel >= 0 && sel <= 5);

				packed_sels |= (static_cast<uint64_t>(s_sels[sel]) << s_etc2_eac_bit_ofs[i]);
			}

			blk.set_selector_bits(packed_sels);

			return;
		}

		const uint32_t T0 = 2, T1 = 8, T2 = 11, T3 = 13;
		static const uint8_t s_tables[4] = { T0, T1, T2, T3 };

		int base[4], mul[4];
		uint32_t mul_or = 0;
		for (uint32_t i = 0; i < 4; i++)
		{
			const uint32_t table = s_tables[i];

			const float range = (float)(g_eac_modifier_table[table][ETC2_EAC_MAX_VALUE_SELECTOR] - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]);

			base[i] = clamp255((int)roundf(basisu::lerp((float)min_alpha, (float)max_alpha, (float)(0 - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]) / range)));
			mul[i] = clampi((int)roundf(alpha_range / range), 1, 15);
			mul_or |= mul[i];
		}

		uint32_t total_err[4] = { 0, 0, 0, 0 };
		uint8_t sels[4][16];

		for (uint32_t i = 0; i < 16; i++)
		{
			const int a = pPixels[i * stride];

			uint32_t l0 = UINT32_MAX, l1 = UINT32_MAX, l2 = UINT32_MAX, l3 = UINT32_MAX;

			if ((a < 7) || (a > (255 - 7)))
			{
				for (uint32_t s = 0; s < 8; s++)
				{
					const int v0 = clamp255(mul[0] * g_eac_modifier_table[T0][s] + base[0]);
					const int v1 = clamp255(mul[1] * g_eac_modifier_table[T1][s] + base[1]);
					const int v2 = clamp255(mul[2] * g_eac_modifier_table[T2][s] + base[2]);
					const int v3 = clamp255(mul[3] * g_eac_modifier_table[T3][s] + base[3]);

					l0 = basisu::minimum(l0, (basisu::iabs(v0 - a) << 3) | s);
					l1 = basisu::minimum(l1, (basisu::iabs(v1 - a) << 3) | s);
					l2 = basisu::minimum(l2, (basisu::iabs(v2 - a) << 3) | s);
					l3 = basisu::minimum(l3, (basisu::iabs(v3 - a) << 3) | s);
				}
			}
			else if (mul_or == 1)
			{
				const int a0 = base[0] - a, a1 = base[1] - a, a2 = base[2] - a, a3 = base[3] - a;

				for (uint32_t s = 0; s < 8; s++)
				{
					const int v0 = g_eac_modifier_table[T0][s] + a0;
					const int v1 = g_eac_modifier_table[T1][s] + a1;
					const int v2 = g_eac_modifier_table[T2][s] + a2;
					const int v3 = g_eac_modifier_table[T3][s] + a3;

					l0 = basisu::minimum(l0, (basisu::iabs(v0) << 3) | s);
					l1 = basisu::minimum(l1, (basisu::iabs(v1) << 3) | s);
					l2 = basisu::minimum(l2, (basisu::iabs(v2) << 3) | s);
					l3 = basisu::minimum(l3, (basisu::iabs(v3) << 3) | s);
				}
			}
			else
			{
				const int a0 = base[0] - a, a1 = base[1] - a, a2 = base[2] - a, a3 = base[3] - a;

				for (uint32_t s = 0; s < 8; s++)
				{
					const int v0 = mul[0] * g_eac_modifier_table[T0][s] + a0;
					const int v1 = mul[1] * g_eac_modifier_table[T1][s] + a1;
					const int v2 = mul[2] * g_eac_modifier_table[T2][s] + a2;
					const int v3 = mul[3] * g_eac_modifier_table[T3][s] + a3;

					l0 = basisu::minimum(l0, (basisu::iabs(v0) << 3) | s);
					l1 = basisu::minimum(l1, (basisu::iabs(v1) << 3) | s);
					l2 = basisu::minimum(l2, (basisu::iabs(v2) << 3) | s);
					l3 = basisu::minimum(l3, (basisu::iabs(v3) << 3) | s);
				}
			}

			sels[0][i] = l0 & 7;
			sels[1][i] = l1 & 7;
			sels[2][i] = l2 & 7;
			sels[3][i] = l3 & 7;

			total_err[0] += basisu::square<uint32_t>(l0 >> 3);
			total_err[1] += basisu::square<uint32_t>(l1 >> 3);
			total_err[2] += basisu::square<uint32_t>(l2 >> 3);
			total_err[3] += basisu::square<uint32_t>(l3 >> 3);
		}

		uint32_t min_err = total_err[0], min_index = 0;
		for (uint32_t i = 1; i < 4; i++)
		{
			if (total_err[i] < min_err)
			{
				min_err = total_err[i];
				min_index = i;
			}
		}

		blk.m_base = base[min_index];
		blk.m_multiplier = mul[min_index];
		blk.m_table = s_tables[min_index];

		uint64_t packed_sels = 0;
		const uint8_t* pSels = &sels[min_index][0];
		for (uint32_t i = 0; i < 16; i++)
			packed_sels |= (static_cast<uint64_t>(pSels[i]) << s_etc2_eac_bit_ofs[i]);

		blk.set_selector_bits(packed_sels);
	}

	// Checks all 16 tables. Around ~2 dB better vs. pack_eac(), ~1.2 dB less than near-optimal.
	static void pack_eac_high_quality(eac_block& blk, const uint8_t* pPixels, uint32_t stride)
	{
		uint32_t min_alpha = 255, max_alpha = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t a = pPixels[i * stride];
			if (a < min_alpha) min_alpha = a;
			if (a > max_alpha) max_alpha = a;
		}

		if (min_alpha == max_alpha)
		{
			pack_eac_solid_block(blk, min_alpha);
			return;
		}

		const uint32_t alpha_range = max_alpha - min_alpha;

		const uint32_t SINGLE_TABLE_THRESH = 5;
		if (alpha_range <= SINGLE_TABLE_THRESH)
		{
			// If alpha_range <= 5 table 13 is lossless
			int base = clamp255((int)max_alpha - 2);

			blk.m_base = base;
			blk.m_multiplier = 1;
			blk.m_table = 13;

			base -= 3;

			uint64_t packed_sels = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				const int a = pPixels[i * stride];

				static const uint8_t s_sels[6] = { 2, 1, 0, 4, 5, 6 };

				int sel = a - base;
				assert(sel >= 0 && sel <= 5);

				packed_sels |= (static_cast<uint64_t>(s_sels[sel]) << s_etc2_eac_bit_ofs[i]);
			}

			blk.set_selector_bits(packed_sels);

			return;
		}

		int base[16], mul[16];
		for (uint32_t table = 0; table < 16; table++)
		{
			const float range = (float)(g_eac_modifier_table[table][ETC2_EAC_MAX_VALUE_SELECTOR] - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]);

			base[table] = clamp255((int)roundf(basisu::lerp((float)min_alpha, (float)max_alpha, (float)(0 - g_eac_modifier_table[table][ETC2_EAC_MIN_VALUE_SELECTOR]) / range)));
			mul[table] = clampi((int)roundf(alpha_range / range), 1, 15);
		}

		uint32_t total_err[16];
		memset(total_err, 0, sizeof(total_err));

		uint8_t sels[16][16];

		for (uint32_t table = 0; table < 16; table++)
		{
			const int8_t* pTable = &g_eac_modifier_table[table][0];
			const int m = mul[table], b = base[table];

			uint32_t prev_l = 0, prev_a = UINT32_MAX;

			for (uint32_t i = 0; i < 16; i++)
			{
				const int a = pPixels[i * stride];

				if ((uint32_t)a == prev_a)
				{
					sels[table][i] = prev_l & 7;
					total_err[table] += basisu::square<uint32_t>(prev_l >> 3);
				}
				else
				{
					uint32_t l = basisu::iabs(clamp255(m * pTable[0] + b) - a) << 3;
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[1] + b) - a) << 3) | 1);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[2] + b) - a) << 3) | 2);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[3] + b) - a) << 3) | 3);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[4] + b) - a) << 3) | 4);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[5] + b) - a) << 3) | 5);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[6] + b) - a) << 3) | 6);
					l = basisu::minimum(l, (basisu::iabs(clamp255(m * pTable[7] + b) - a) << 3) | 7);

					sels[table][i] = l & 7;
					total_err[table] += basisu::square<uint32_t>(l >> 3);

					prev_l = l;
					prev_a = a;
				}
			}
		}

		uint32_t min_err = total_err[0], min_index = 0;
		for (uint32_t i = 1; i < 16; i++)
		{
			if (total_err[i] < min_err)
			{
				min_err = total_err[i];
				min_index = i;
			}
		}

		blk.m_base = base[min_index];
		blk.m_multiplier = mul[min_index];
		blk.m_table = min_index;

		uint64_t packed_sels = 0;
		const uint8_t* pSels = &sels[min_index][0];
		for (uint32_t i = 0; i < 16; i++)
			packed_sels |= (static_cast<uint64_t>(pSels[i]) << s_etc2_eac_bit_ofs[i]);

		blk.set_selector_bits(packed_sels);
	}

	bool transcode_uastc_to_etc2_eac_r11(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			pack_eac_solid_block(*static_cast<eac_block*>(pDst), unpacked_src_blk.m_solid_color.c[chan0]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		if (chan0 == 3)
			transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, pDst);
		else
			(high_quality ? pack_eac_high_quality : pack_eac)(*static_cast<eac_block*>(pDst), &block_pixels[0][0].c[chan0], sizeof(color32));

		return true;
	}

	bool transcode_uastc_to_etc2_eac_rg11(const uastc_block& src_blk, void* pDst, bool high_quality, uint32_t chan0, uint32_t chan1)
	{
		unpacked_uastc_block unpacked_src_blk;
		if (!unpack_uastc(src_blk, unpacked_src_blk, false))
			return false;

		const uint32_t mode = unpacked_src_blk.m_mode;

		if (mode == UASTC_MODE_INDEX_SOLID_COLOR)
		{
			pack_eac_solid_block(static_cast<eac_block*>(pDst)[0], unpacked_src_blk.m_solid_color.c[chan0]);
			pack_eac_solid_block(static_cast<eac_block*>(pDst)[1], unpacked_src_blk.m_solid_color.c[chan1]);
			return true;
		}

		color32 block_pixels[4][4];
		const bool unpack_srgb = false;
		if (!unpack_uastc(unpacked_src_blk, &block_pixels[0][0], unpack_srgb))
			return false;

		if (chan0 == 3)
			transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, &static_cast<eac_block*>(pDst)[0]);
		else
			(high_quality ? pack_eac_high_quality : pack_eac)(static_cast<eac_block*>(pDst)[0], &block_pixels[0][0].c[chan0], sizeof(color32));

		if (chan1 == 3)
			transcode_uastc_to_etc2_eac_a8(unpacked_src_blk, block_pixels, &static_cast<eac_block*>(pDst)[1]);
		else
			(high_quality ? pack_eac_high_quality : pack_eac)(static_cast<eac_block*>(pDst)[1], &block_pixels[0][0].c[chan1], sizeof(color32));
		return true;
	}

	// PVRTC1
	static void fixup_pvrtc1_4_modulation_rgb(
		const uastc_block* pSrc_blocks,
		const uint32_t* pPVRTC_endpoints,
		void* pDst_blocks,
		uint32_t num_blocks_x, uint32_t num_blocks_y, bool from_alpha)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1;

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1;

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31;
					e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31;
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const uastc_block& src_block = pSrc_blocks[block_index];

				color32 block_pixels[4][4];
				unpack_uastc(src_block, &block_pixels[0][0], false);
				if (from_alpha)
				{
					// Just set RGB to alpha to avoid adding complexity below.
					for (uint32_t i = 0; i < 16; i++)
					{
						const uint8_t a = ((color32*)block_pixels)[i].a;
						((color32*)block_pixels)[i].set(a, a, a, 255);
					}
				}

				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31; \
						e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31; \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = (block_pixels[ly][lx].r + block_pixels[ly][lx].g + block_pixels[ly][lx].b) * 16; \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}

	static void fixup_pvrtc1_4_modulation_rgba(
		const uastc_block* pSrc_blocks,
		const uint32_t* pPVRTC_endpoints,
		void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y)
	{
		const uint32_t x_mask = num_blocks_x - 1;
		const uint32_t y_mask = num_blocks_y - 1;
		const uint32_t x_bits = basisu::total_bits(x_mask);
		const uint32_t y_bits = basisu::total_bits(y_mask);
		const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
		//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
		const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

		uint32_t block_index = 0;

		// really 3x3
		int e0[4][4], e1[4][4];

		for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
		{
			const uint32_t* pE_rows[3];

			for (int ey = 0; ey < 3; ey++)
			{
				int by = y + ey - 1;

				const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

				pE_rows[ey] = pE;

				for (int ex = 0; ex < 3; ex++)
				{
					int bx = 0 + ex - 1;

					const uint32_t e = pE[bx & x_mask];

					e0[ex][ey] = get_endpoint_l8(e, 0);
					e1[ex][ey] = get_endpoint_l8(e, 1);
				}
			}

			const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

			for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
			{
				const uastc_block& src_block = pSrc_blocks[block_index];

				color32 block_pixels[4][4];
				unpack_uastc(src_block, &block_pixels[0][0], false);

				const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

				uint32_t swizzled = x_swizzle | y_swizzle;
				if (num_blocks_x != num_blocks_y)
				{
					swizzled &= swizzle_mask;

					if (num_blocks_x > num_blocks_y)
						swizzled |= ((x >> min_bits) << (min_bits * 2));
					else
						swizzled |= ((y >> min_bits) << (min_bits * 2));
				}

				pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
				pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

				{
					const uint32_t ex = 2;
					int bx = x + ex - 1;
					bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = get_endpoint_l8(e, 0); \
						e1[ex][ey] = get_endpoint_l8(e, 1); \
					}

					DO_ROW(0);
					DO_ROW(1);
					DO_ROW(2);
#undef DO_ROW
				}

				uint32_t mod = 0;

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = 16 * (block_pixels[ly][lx].r + block_pixels[ly][lx].g + block_pixels[ly][lx].b + block_pixels[ly][lx].a); \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

				{
					const uint32_t ex = 0, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 0, 4, 4, 4, 4);
					DO_PIX(1, 0, 2, 6, 2, 6);
					DO_PIX(0, 1, 2, 2, 6, 6);
					DO_PIX(1, 1, 1, 3, 3, 9);
				}

				{
					const uint32_t ex = 1, ey = 0;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 0, 8, 0, 8, 0);
					DO_PIX(3, 0, 6, 2, 6, 2);
					DO_PIX(2, 1, 4, 0, 12, 0);
					DO_PIX(3, 1, 3, 1, 9, 3);
				}

				{
					const uint32_t ex = 0, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(0, 2, 8, 8, 0, 0);
					DO_PIX(1, 2, 4, 12, 0, 0);
					DO_PIX(0, 3, 6, 6, 2, 2);
					DO_PIX(1, 3, 3, 9, 1, 3);
				}

				{
					const uint32_t ex = 1, ey = 1;
					const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
					const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
					DO_PIX(2, 2, 16, 0, 0, 0);
					DO_PIX(3, 2, 12, 4, 0, 0);
					DO_PIX(2, 3, 12, 0, 4, 0);
					DO_PIX(3, 3, 9, 3, 3, 1);
				}
#undef DO_PIX

				pDst_block->m_modulation = mod;

				e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
				e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
				e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

				e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
				e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
				e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

			} // x
		} // y
	}

	bool transcode_uastc_to_pvrtc1_4_rgb(const uastc_block* pSrc_blocks, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, bool high_quality, bool from_alpha)
	{
		BASISU_NOTE_UNUSED(high_quality);

		if ((!num_blocks_x) || (!num_blocks_y))
			return false;

		const uint32_t width = num_blocks_x * 4;
		const uint32_t height = num_blocks_y * 4;
		if (!basisu::is_pow2(width) || !basisu::is_pow2(height))
			return false;

		basisu::vector<uint32_t> temp_endpoints(num_blocks_x * num_blocks_y);

		for (uint32_t y = 0; y < num_blocks_y; y++)
		{
			for (uint32_t x = 0; x < num_blocks_x; x++)
			{
				color32 block_pixels[16];
				if (!unpack_uastc(pSrc_blocks[x + y * num_blocks_x], block_pixels, false))
					return false;

				// Get block's RGB bounding box 
				color32 low_color(255, 255, 255, 255), high_color(0, 0, 0, 0);

				if (from_alpha)
				{
					uint32_t low_a = 255, high_a = 0;
					for (uint32_t i = 0; i < 16; i++)
					{
						low_a = basisu::minimum<uint32_t>(low_a, block_pixels[i].a);
						high_a = basisu::maximum<uint32_t>(high_a, block_pixels[i].a);
					}
					low_color.set(low_a, low_a, low_a, 255);
					high_color.set(high_a, high_a, high_a, 255);
				}
				else
				{
					for (uint32_t i = 0; i < 16; i++)
					{
						low_color = color32::comp_min(low_color, block_pixels[i]);
						high_color = color32::comp_max(high_color, block_pixels[i]);
					}
				}

				// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
				pvrtc4_block temp;
				temp.set_opaque_endpoint_floor(0, low_color);
				temp.set_opaque_endpoint_ceil(1, high_color);

				temp_endpoints[x + y * num_blocks_x] = temp.m_endpoints;
			}
		}

		fixup_pvrtc1_4_modulation_rgb(pSrc_blocks, &temp_endpoints[0], pDst_blocks, num_blocks_x, num_blocks_y, from_alpha);

		return true;
	}

	bool transcode_uastc_to_pvrtc1_4_rgba(const uastc_block* pSrc_blocks, void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y, bool high_quality)
	{
		BASISU_NOTE_UNUSED(high_quality);

		if ((!num_blocks_x) || (!num_blocks_y))
			return false;

		const uint32_t width = num_blocks_x * 4;
		const uint32_t height = num_blocks_y * 4;
		if (!basisu::is_pow2(width) || !basisu::is_pow2(height))
			return false;

		basisu::vector<uint32_t> temp_endpoints(num_blocks_x * num_blocks_y);

		for (uint32_t y = 0; y < num_blocks_y; y++)
		{
			for (uint32_t x = 0; x < num_blocks_x; x++)
			{
				color32 block_pixels[16];
				if (!unpack_uastc(pSrc_blocks[x + y * num_blocks_x], block_pixels, false))
					return false;

				// Get block's RGBA bounding box 
				color32 low_color(255, 255, 255, 255), high_color(0, 0, 0, 0);

				for (uint32_t i = 0; i < 16; i++)
				{
					low_color = color32::comp_min(low_color, block_pixels[i]);
					high_color = color32::comp_max(high_color, block_pixels[i]);
				}

				// Set PVRTC1 endpoints to floor/ceil of bounding box's coordinates.
				pvrtc4_block temp;
				temp.set_endpoint_floor(0, low_color);
				temp.set_endpoint_ceil(1, high_color);

				temp_endpoints[x + y * num_blocks_x] = temp.m_endpoints;
			}
		}

		fixup_pvrtc1_4_modulation_rgba(pSrc_blocks, &temp_endpoints[0], pDst_blocks, num_blocks_x, num_blocks_y);

		return true;
	}

	void uastc_init()
	{
		for (uint32_t range = 0; range < BC7ENC_TOTAL_ASTC_RANGES; range++)
		{
			if (!astc_is_valid_endpoint_range(range))
				continue;

			const uint32_t levels = astc_get_levels(range);

			uint32_t vals[256];
			for (uint32_t i = 0; i < levels; i++)
				vals[i] = (unquant_astc_endpoint_val(i, range) << 8) | i;

			std::sort(vals, vals + levels);

			for (uint32_t i = 0; i < levels; i++)
			{
				const uint32_t order = vals[i] & 0xFF;
				const uint32_t unq = vals[i] >> 8;

				g_astc_unquant[range][order].m_unquant = (uint8_t)unq;
				g_astc_unquant[range][order].m_index = (uint8_t)i;

			} // i
		}

		// TODO: Precompute?
		// BC7 777.1
		for (int c = 0; c < 256; c++)
		{
			for (uint32_t lp = 0; lp < 2; lp++)
			{
				endpoint_err best;
				best.m_error = (uint16_t)UINT16_MAX;

				for (uint32_t l = 0; l < 128; l++)
				{
					const uint32_t low = (l << 1) | lp;

					for (uint32_t h = 0; h < 128; h++)
					{
						const uint32_t high = (h << 1) | lp;

						const int k = (low * (64 - g_bc7_weights4[BC7ENC_MODE_6_OPTIMAL_INDEX]) + high * g_bc7_weights4[BC7ENC_MODE_6_OPTIMAL_INDEX] + 32) >> 6;

						const int err = (k - c) * (k - c);
						if (err < best.m_error)
						{
							best.m_error = (uint16_t)err;
							best.m_lo = (uint8_t)l;
							best.m_hi = (uint8_t)h;
						}
					} // h
				} // l

				g_bc7_mode_6_optimal_endpoints[c][lp] = best;
			} // lp

		} // c

		// BC7 777
		for (int c = 0; c < 256; c++)
		{
			endpoint_err best;
			best.m_error = (uint16_t)UINT16_MAX;

			for (uint32_t l = 0; l < 128; l++)
			{
				const uint32_t low = (l << 1) | (l >> 6);

				for (uint32_t h = 0; h < 128; h++)
				{
					const uint32_t high = (h << 1) | (h >> 6);

					const int k = (low * (64 - g_bc7_weights2[BC7ENC_MODE_5_OPTIMAL_INDEX]) + high * g_bc7_weights2[BC7ENC_MODE_5_OPTIMAL_INDEX] + 32) >> 6;

					const int err = (k - c) * (k - c);
					if (err < best.m_error)
					{
						best.m_error = (uint16_t)err;
						best.m_lo = (uint8_t)l;
						best.m_hi = (uint8_t)h;
					}
				} // h
			} // l

			g_bc7_mode_5_optimal_endpoints[c] = best;

		} // c
	}

#endif // #if BASISD_SUPPORT_UASTC

// ------------------------------------------------------------------------------------------------------ 
// KTX2
// ------------------------------------------------------------------------------------------------------ 

#if BASISD_SUPPORT_KTX2
	const uint8_t g_ktx2_file_identifier[12] = { 0xAB, 0x4B, 0x54, 0x58, 0x20, 0x32, 0x30, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A };

	ktx2_transcoder::ktx2_transcoder() :
		m_etc1s_transcoder()
	{
		clear();
	}

	void ktx2_transcoder::clear()
	{
		m_pData = nullptr;
		m_data_size = 0;

		memset((void *)&m_header, 0, sizeof(m_header));
		m_levels.clear();
		m_dfd.clear();
		m_key_values.clear();
		memset((void *)&m_etc1s_header, 0, sizeof(m_etc1s_header));
		m_etc1s_image_descs.clear();
		m_slice_offset_len_descs.clear();
				
		m_format = basist::basis_tex_format::cETC1S;

		m_dfd_color_model = 0;
		m_dfd_color_prims = KTX2_DF_PRIMARIES_UNSPECIFIED;
		m_dfd_transfer_func = 0;
		m_dfd_flags = 0;
		m_dfd_samples = 0;
		m_dfd_chan0 = KTX2_DF_CHANNEL_UASTC_RGB;
		m_dfd_chan1 = KTX2_DF_CHANNEL_UASTC_RGB;

		m_etc1s_transcoder.clear();
				
		m_def_transcoder_state.clear();
		
		m_has_alpha = false;
		m_is_video = false;
		m_ldr_hdr_upconversion_nit_multiplier = 0.0f;

		m_deblocking_filter_index = 0;
	}

	static bool is_vk_format_astc_ldr(uint32_t fmt)
	{
		return (fmt >= KTX2_FORMAT_ASTC_4x4_UNORM_BLOCK) && (fmt <= KTX2_FORMAT_ASTC_12x12_SRGB_BLOCK);
	}

	bool ktx2_transcoder::init(const void* pData, uint32_t data_size)
	{
		clear();

		if (!pData)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: pData is nullptr\n");
			assert(0);
			return false;
		}

		if (data_size <= sizeof(ktx2_header))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: File is impossibly too small to be a valid KTX2 file\n");
			return false;
		}

		if (memcmp(pData, g_ktx2_file_identifier, sizeof(g_ktx2_file_identifier)) != 0)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: KTX2 file identifier is not present\n");
			return false;
		}

		m_pData = static_cast<const uint8_t *>(pData);
		m_data_size = data_size;

		memcpy((void *)&m_header, pData, sizeof(m_header));

		// Check for supported VK formats. We may also need to parse the DFD.
		if ((m_header.m_vk_format != KTX2_VK_FORMAT_UNDEFINED) && 
			(m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_4x4_SFLOAT_BLOCK) && 
			(m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_6x6_SFLOAT_BLOCK) &&
			!is_vk_format_astc_ldr(m_header.m_vk_format))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: KTX2 file must be in ETC1S or UASTC LDR/HDR format\n");
			return false;
		}

		// 3.3: "When format is VK_FORMAT_UNDEFINED, typeSize must equal 1."
		if (m_header.m_type_size != 1)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid type_size\n");
			return false;
		}

		// We only currently support 2D textures (plain, cubemapped, or texture array), which is by far the most common use case.
		// The BasisU library does not support 1D or 3D textures at all.
		if ((m_header.m_pixel_width < 1) || (m_header.m_pixel_height < 1) || (m_header.m_pixel_depth > 0))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Only 2D or cubemap textures are supported\n");
			return false;
		}

		// Sanity check the dimensions
		if ((m_header.m_pixel_width > BASISU_MAX_SUPPORTED_TEXTURE_DIMENSION) || (m_header.m_pixel_height > BASISU_MAX_SUPPORTED_TEXTURE_DIMENSION))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Texture is too large\n");
			return false;
		}

		// Face count must be 1 or 6
		if ((m_header.m_face_count != 1) && (m_header.m_face_count != 6))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid face count, file is corrupted or invalid\n");
			return false;
		}

		if (m_header.m_face_count > 1)
		{
			// 3.4: Make sure cubemaps are square.
			if (m_header.m_pixel_width != m_header.m_pixel_height)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Cubemap is not square\n");
				return false;
			}
		}
		
		// 3.7 levelCount: "levelCount=0 is allowed, except for block-compressed formats"
		if (m_header.m_level_count < 1)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level count\n");
			return false;
		}

		// Sanity check the level count.
		if (m_header.m_level_count > KTX2_MAX_SUPPORTED_LEVEL_COUNT)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Too many levels or file is corrupted or invalid\n");
			return false;
		}

		// Sanity check the layer count. m_layer_count is a full attacker-controlled 32-bit value; bound it so that layer_count * face_count * level_count (used to size the per-image descriptor arrays) stays small. (layer_count==0 means a non-array texture, i.e. one layer.)
		if (m_header.m_layer_count > KTX2_MAX_SUPPORTED_LAYER_COUNT)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Too many layers or file is corrupted or invalid\n");
			return false;
		}

		if ((m_header.m_supercompression_scheme == KTX2_SS_UASTC_HDR_6x6I) ||
			(m_header.m_supercompression_scheme == KTX2_SS_XUASTC_LDR) ||
			(m_header.m_supercompression_scheme == KTX2_SS_XUBC7))
		{
			// standard UASTC HDR 6x6i file (as adopted by khronos, not our initial v1.6/v2.0 release), or XUASTC LDR - DFD colormodels unchanged however
		}
		else if (m_header.m_supercompression_scheme > KTX2_SS_ZSTANDARD)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid/unsupported supercompression or file is corrupted or invalid\n");
			return false;
		}

		// Sanity check SGD offset/length
		if ((m_header.m_supercompression_scheme == KTX2_SS_BASISLZ) ||
			(m_header.m_supercompression_scheme == KTX2_SS_UASTC_HDR_6x6I) ||
			(m_header.m_supercompression_scheme == KTX2_SS_XUASTC_LDR) ||
			(m_header.m_supercompression_scheme == KTX2_SS_XUBC7))
		{
			const uint64_t sgd_byte_offset = m_header.m_sgd_byte_offset.get_uint64();
			const uint64_t sgd_byte_length = m_header.m_sgd_byte_length.get_uint64();

			if (sgd_byte_offset < sizeof(ktx2_header))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Supercompression global data offset is too low\n");
				return false;
			}

			// Overflow-safe range check: m_sgd_byte_offset/m_sgd_byte_length are attacker-controlled full 64-bit values, so "offset + length > m_data_size" can wrap past 2^64 and pass. Compare against the remaining bytes instead (sgd_byte_offset <= m_data_size is checked first, so the subtraction can't underflow).
			if ((sgd_byte_offset > m_data_size) || (sgd_byte_length > (uint64_t)m_data_size - sgd_byte_offset))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Supercompression global data offset and/or length is too high\n");
				return false;
			}
		}

		if (!m_levels.try_resize(m_header.m_level_count))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Out of memory\n");
			return false;
		}

		const uint32_t level_index_size_in_bytes = basisu::maximum(1U, (uint32_t)m_header.m_level_count) * sizeof(ktx2_level_index);

		if ((sizeof(ktx2_header) + level_index_size_in_bytes) > m_data_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: File is too small (can't read level index array)\n");
			return false;
		}

		memcpy((void *)&m_levels[0], m_pData + sizeof(ktx2_header), level_index_size_in_bytes);
		
		// Sanity check the level offsets and byte sizes
		for (uint32_t i = 0; i < m_levels.size(); i++)
		{
			const uint64_t level_byte_offset = m_levels[i].m_byte_offset.get_uint64();
			const uint64_t level_byte_length = m_levels[i].m_byte_length.get_uint64();

			if (level_byte_offset < sizeof(ktx2_header))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level offset (too low)\n");
				return false;
			}

			if (!level_byte_length)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level byte length\n");
				return false;
			}

			// Overflow-safe range check: m_byte_offset/m_byte_length are attacker-controlled full 64-bit values, so "offset + length > m_data_size" can wrap past 2^64 and pass, leaving an arbitrarily large offset that later flows into pointer arithmetic (transcode_image_level/decompress_level_data). Compare against the remaining bytes instead (level_byte_offset <= m_data_size is checked first, so the subtraction can't underflow).
			if ((level_byte_offset > m_data_size) || (level_byte_length > (uint64_t)m_data_size - level_byte_offset))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level offset and/or length\n");
				return false;
			}
			
			const uint64_t MAX_SANE_LEVEL_UNCOMP_SIZE = 2048ULL * 1024ULL * 1024ULL;
			
			if (m_levels[i].m_uncompressed_byte_length.get_uint64() >= MAX_SANE_LEVEL_UNCOMP_SIZE)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level uncompressed byte length (too large)\n");
				return false;
			}

			if ((m_header.m_supercompression_scheme == KTX2_SS_BASISLZ) ||
				(m_header.m_supercompression_scheme == KTX2_SS_UASTC_HDR_6x6I) ||
				(m_header.m_supercompression_scheme == KTX2_SS_XUASTC_LDR) ||
				(m_header.m_supercompression_scheme == KTX2_SS_XUBC7))
			{
				// Our supercompressed codec formats: Uncompressed length should be 0
				if (m_levels[i].m_uncompressed_byte_length.get_uint64())
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid uncompressed length (0)\n");
					return false;
				}
			}
			else if (m_header.m_supercompression_scheme == KTX2_SS_ZSTANDARD)
			{
				// Uses Zstandard supercompression, ensure uncompressed length is valid.
				if (!m_levels[i].m_uncompressed_byte_length.get_uint64())
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid uncompressed length (1)\n");
					return false;
				}
			}
		}

		const uint32_t DFD_MINIMUM_SIZE = 44, DFD_MAXIMUM_SIZE = 60;
		if ((m_header.m_dfd_byte_length != DFD_MINIMUM_SIZE) && (m_header.m_dfd_byte_length != DFD_MAXIMUM_SIZE))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Unsupported DFD size\n");
			return false;
		}

		if (((m_header.m_dfd_byte_offset.get_uint64() + m_header.m_dfd_byte_length.get_uint64()) > m_data_size) || (m_header.m_dfd_byte_offset < sizeof(ktx2_header)))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid DFD offset and/or length\n");
			return false;
		}
				
		const uint8_t* pDFD = m_pData + m_header.m_dfd_byte_offset;

		if (!m_dfd.try_resize(m_header.m_dfd_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Out of memory\n");
			return false;
		}

		memcpy(m_dfd.data(), pDFD, m_header.m_dfd_byte_length);
				
		uint32_t dfd_total_size = basisu::read_le_dword(pDFD);
		
		// 3.10.3: Sanity check
		if (dfd_total_size != m_header.m_dfd_byte_length)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: DFD size validation failed (1)\n");
			return false;
		}
				
		// 3.10.3: More sanity checking
		if (m_header.m_kvd_byte_length)
		{
			if (dfd_total_size != m_header.m_kvd_byte_offset - m_header.m_dfd_byte_offset)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: DFD size validation failed (2)\n");
				return false;
			}
		}

		const uint32_t dfd_bits = basisu::read_le_dword(pDFD + 3 * sizeof(uint32_t));
		const uint32_t sample_channel0 = basisu::read_le_dword(pDFD + 7 * sizeof(uint32_t));
		const uint32_t texel_block_dimensions = basisu::read_le_dword(pDFD + 4 * sizeof(uint32_t));
		 
		m_dfd_color_model = dfd_bits & 255;
		m_dfd_color_prims = (ktx2_df_color_primaries)((dfd_bits >> 8) & 255);
		m_dfd_transfer_func = (dfd_bits >> 16) & 255;
		m_dfd_flags = (dfd_bits >> 24) & 255;

		const uint32_t block_width = (texel_block_dimensions & 0xFF) + 1;
		const uint32_t block_height = ((texel_block_dimensions >> 8) & 0xFF) + 1;

		// See 3.10.1.Restrictions
		if ((m_dfd_transfer_func != KTX2_KHR_DF_TRANSFER_LINEAR) && (m_dfd_transfer_func != KTX2_KHR_DF_TRANSFER_SRGB))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid DFD transfer function\n");
			return false;
		}

		if (is_vk_format_astc_ldr(m_header.m_vk_format))
		{
			// ASTC LDR 4x4-12x12
			// We usually read the DFD and decide the format from there. This decides off the VK format.
			if (m_dfd_color_model != KTX2_KDF_DF_MODEL_ASTC)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid DFD color model (expected ASTC)\n");
				return false;
			}
						
			uint32_t vk_fmt = m_header.m_vk_format;
			const bool is_srgb_fmt = (vk_fmt & 1) == 0;

			if (is_srgb_fmt)
				vk_fmt--;

			switch (vk_fmt)
			{
			case KTX2_FORMAT_ASTC_4x4_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_4x4; break;
			case KTX2_FORMAT_ASTC_5x4_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_5x4; break;
			case KTX2_FORMAT_ASTC_5x5_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_5x5; break;
			case KTX2_FORMAT_ASTC_6x5_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_6x5; break;
			case KTX2_FORMAT_ASTC_6x6_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_6x6; break;
			case KTX2_FORMAT_ASTC_8x5_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_8x5; break;
			case KTX2_FORMAT_ASTC_8x6_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_8x6; break;
			case KTX2_FORMAT_ASTC_8x8_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_8x8; break;
			case KTX2_FORMAT_ASTC_10x5_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_10x5; break;
			case KTX2_FORMAT_ASTC_10x6_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_10x6; break;
			case KTX2_FORMAT_ASTC_10x8_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_10x8; break;
			case KTX2_FORMAT_ASTC_10x10_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_10x10; break;
			case KTX2_FORMAT_ASTC_12x10_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_12x10; break;
			case KTX2_FORMAT_ASTC_12x12_UNORM_BLOCK: m_format = basis_tex_format::cASTC_LDR_12x12; break;
			default:
				assert(0);
				return false;
			}

			// Sanity check the vkformat's astc block size vs. the DFD's.
			uint32_t actual_block_width = 0, actual_block_height = 0;
			get_basis_tex_format_block_size(m_format, actual_block_width, actual_block_height);
			if ((actual_block_width != block_width) || (actual_block_height != block_height))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: vkFormat's ASTC block size is not in sync with the DFD's block dimensions\n");
				return false;
			}

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			// We're assuming "DATA" means RGBA so it has alpha.
			m_has_alpha = (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RGBA) || (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RRRG);
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_ETC1S)
		{
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cETC1S;
			
			// 3.10.2: "Whether the image has 1 or 2 slices can be determined from the DFD's sample count."
			// If m_has_alpha is true it may be 2-channel RRRG or 4-channel RGBA, but we let the caller deal with that.
			m_has_alpha = (m_header.m_dfd_byte_length == 60);
			
			m_dfd_samples = m_has_alpha ? 2 : 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			if (m_has_alpha)
			{
				const uint32_t sample_channel1 = basisu::read_le_dword(pDFD + 11 * sizeof(uint32_t));
				m_dfd_chan1 = (ktx2_df_channel_id)((sample_channel1 >> 24) & 15);
			}
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_UASTC_LDR_4X4)
		{
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cUASTC_LDR_4x4;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);
			
			// We're assuming "DATA" means RGBA so it has alpha.
			m_has_alpha = (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RGBA) || (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RRRG);
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_UASTC_HDR_4X4)
		{
			// UASTC HDR 4x4 is standard ASTC HDR 4x4 texture data. Check the header's vkFormat.
			if (m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_4x4_SFLOAT_BLOCK)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cUASTC_HDR_4x4;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			// We're assuming "DATA" means RGBA so it has alpha.
			// [11/26/2024] - changed to always false for now
			m_has_alpha = false;// (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RGBA) || (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RRRG);
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_ASTC)
		{
			// The DFD indicates plain ASTC texture data. We only support ASTC HDR 6x6 - check the header's vkFormat.
			if (m_header.m_vk_format != basist::KTX2_FORMAT_ASTC_6x6_SFLOAT_BLOCK)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: DVD color model is ASTC, but the header's vkFormat isn't KTX2_FORMAT_ASTC_6x6_SFLOAT_BLOCK\n");
				return false;
			}

			m_format = basist::basis_tex_format::cASTC_HDR_6x6;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			m_has_alpha = false;
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_UASTC_HDR_6X6_INTERMEDIATE)
		{
			// Note: The supercompression scheme may be BASISLZ if it's an old format (v1.6/v2.0) file
			
			// Custom variable block size ASTC HDR 6x6 texture data.
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			m_has_alpha = false;
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_XUASTC_LDR_INTERMEDIATE)
		{
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			// Extract ASTC block dimensions from texel_block_dimensions, validate, select basis_tex_format.
			m_format = basist::basis_tex_format::cETC1S; // bogus value to start

#define BUT_BLOCK_SIZE(x, y, t) if ((block_width == (x)) && (block_height == (y))) { m_format = (t); }
			BUT_BLOCK_SIZE(4, 4, basis_tex_format::cXUASTC_LDR_4x4);
			BUT_BLOCK_SIZE(5, 4, basis_tex_format::cXUASTC_LDR_5x4);
			BUT_BLOCK_SIZE(5, 5, basis_tex_format::cXUASTC_LDR_5x5);
			BUT_BLOCK_SIZE(6, 5, basis_tex_format::cXUASTC_LDR_6x5);
			BUT_BLOCK_SIZE(6, 6, basis_tex_format::cXUASTC_LDR_6x6);
			BUT_BLOCK_SIZE(8, 5, basis_tex_format::cXUASTC_LDR_8x5);
			BUT_BLOCK_SIZE(8, 6, basis_tex_format::cXUASTC_LDR_8x6);
			BUT_BLOCK_SIZE(10, 5, basis_tex_format::cXUASTC_LDR_10x5);
			BUT_BLOCK_SIZE(10, 6, basis_tex_format::cXUASTC_LDR_10x6);
			BUT_BLOCK_SIZE(8, 8, basis_tex_format::cXUASTC_LDR_8x8);
			BUT_BLOCK_SIZE(10, 8, basis_tex_format::cXUASTC_LDR_10x8);
			BUT_BLOCK_SIZE(10, 10, basis_tex_format::cXUASTC_LDR_10x10);
			BUT_BLOCK_SIZE(12, 10, basis_tex_format::cXUASTC_LDR_12x10);
			BUT_BLOCK_SIZE(12, 12, basis_tex_format::cXUASTC_LDR_12x12);
#undef BUT_BLOCK_SIZE

			if (m_format == basist::basis_tex_format::cETC1S)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Unsupported XUASTC LDR block dimensions (not valid ASTC)\n");
				return false;
			}
									
			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			m_has_alpha = (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RGBA) || (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RRRG);
		}
		else if (m_dfd_color_model == KTX2_KDF_DF_MODEL_XUBC7)
		{
			// XUBC7
			if (m_header.m_vk_format != basist::KTX2_VK_FORMAT_UNDEFINED)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid header vkFormat\n");
				return false;
			}

			m_format = basist::basis_tex_format::cXUBC7;

			m_dfd_samples = 1;
			m_dfd_chan0 = (ktx2_df_channel_id)((sample_channel0 >> 24) & 15);

			// We're assuming "DATA" means RGBA so it has alpha. Note the format itself has an has_alpha flag on every mipmap level, and block width/height, which it uses internally (this is only for outside callers).
			m_has_alpha = (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RGBA) || (m_dfd_chan0 == KTX2_DF_CHANNEL_UASTC_RRRG);
		}
		else
		{
			// Unsupported DFD color model.
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: Unsupported DFD color model\n");
			return false;
		}
				
		if (!read_key_values())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::init: read_key_values() failed\n");
			return false;
		}

		// Check for a KTXanimData key
		for (uint32_t i = 0; i < m_key_values.size(); i++)
		{
			if (strcmp(reinterpret_cast<const char*>(m_key_values[i].m_key.data()), "KTXanimData") == 0)
			{
				m_is_video = true;
				break;
			}
		}

		m_ldr_hdr_upconversion_nit_multiplier = 0.0f;

		for (uint32_t i = 0; i < m_key_values.size(); i++)
		{
			if (strcmp(reinterpret_cast<const char*>(m_key_values[i].m_key.data()), "LDRUpconversionMultiplier") == 0)
			{
				m_ldr_hdr_upconversion_nit_multiplier = (float)atof(reinterpret_cast<const char*>(m_key_values[i].m_value.data()));

				if (std::isnan(m_ldr_hdr_upconversion_nit_multiplier) || std::isinf(m_ldr_hdr_upconversion_nit_multiplier) || (m_ldr_hdr_upconversion_nit_multiplier < 0.0f))
					m_ldr_hdr_upconversion_nit_multiplier = 0;

				break;
			}
		}

		m_deblocking_filter_index = 0;

		if (basis_tex_format_is_astc_ldr(m_format) || basis_tex_format_is_xuastc_ldr(m_format))
		{
			// Check for the deblocking filter ID key. 
			const basisu::uint8_vec* pVal = find_key(BASISU_DEBLOCK_FILTER_ID_NAME);

			if (pVal)
			{
				if (((*pVal)[0] == '1') && ((*pVal)[1] == '\0'))
				{
					m_deblocking_filter_index = 1;
				}
			}
		}

		return true;
	}

	uint32_t ktx2_transcoder::get_etc1s_image_descs_image_flags(uint32_t level_index, uint32_t layer_index, uint32_t face_index) const
	{
		const uint32_t etc1s_image_index =
			(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
			layer_index * m_header.m_face_count +
			face_index;

		if (etc1s_image_index >= get_etc1s_image_descs().size())
		{
			assert(0);
			return 0;
		}

		return get_etc1s_image_descs()[etc1s_image_index].m_image_flags;
	}

	const basisu::uint8_vec* ktx2_transcoder::find_key(const std::string& key_name) const
	{
		for (uint32_t i = 0; i < m_key_values.size(); i++)
			if (strcmp((const char *)m_key_values[i].m_key.data(), key_name.c_str()) == 0)
				return &m_key_values[i].m_value;

		return nullptr;
	}
	
	bool ktx2_transcoder::start_transcoding()
	{
		if (!m_pData)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: Must call init() first\n");
			return false;
		}

		// In standard KTX2 file, KTX2_SS_BASISLZ would ONLY be ETC1S, but in v1.6 and v2.0 it could also mean UASTC HDR 6x6i or XUASTC LDR. 
		// We support our older files, too.
		if (m_header.m_supercompression_scheme == KTX2_SS_BASISLZ) 
		{
			if (m_format == basis_tex_format::cETC1S)
			{
				// Check if we've already decompressed the ETC1S global data. If so don't unpack it again.
				if (!m_etc1s_transcoder.get_endpoints().empty())
					return true;
				 
				if (!decompress_etc1s_global_data())
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: decompress_etc1s_global_data() failed\n");
					return false;
				}

				if (!m_is_video)
				{
					// See if there are any P-frames. If so it must be a video, even if there wasn't a KTXanimData key.
					// Video cannot be a cubemap, and it must be a texture array.
					if ((m_header.m_face_count == 1) && (m_header.m_layer_count > 1))
					{
						for (uint32_t i = 0; i < m_etc1s_image_descs.size(); i++)
						{
							if (m_etc1s_image_descs[i].m_image_flags & KTX2_IMAGE_IS_P_FRAME)
							{
								m_is_video = true;
								break;
							}
						}
					}
				}
			}
			// check for old-style (non-standard) KTX2 files written by v1.6/v2.0
			else if ( (m_format == basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE) || basis_tex_format_is_xuastc_ldr(m_format) )
			{
				// UASTC HDR 6x6 and XUASTC LDR 4x4-12x12 require an array of slice offset/len structs to determine where the compressed data starts for each independent compressed texture slice.
				if (m_slice_offset_len_descs.size())
					return true;

				if (!read_slice_offset_len_global_data(false))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: read_slice_offset_len_global_data() failed\n");
					return false;
				}
			}
			else
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: Invalid supercompression scheme and/or format\n");
				return false;
			}
		}
		else if ((m_header.m_supercompression_scheme == KTX2_SS_UASTC_HDR_6x6I) || (m_header.m_supercompression_scheme == KTX2_SS_XUASTC_LDR) || (m_header.m_supercompression_scheme == KTX2_SS_XUBC7))
		{
			// UASTC HDR 6x6, XUASTC LDR 4x4-12x12, and XUBC7 require an array of slice offset/len structs to determine where the compressed data starts for each independent compressed texture slice.
			if (m_slice_offset_len_descs.size())
				return true;

			if (!read_slice_offset_len_global_data(true))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: read_slice_offset_len_global_data() failed\n");
				return false;
			}
		}
		else if (m_header.m_supercompression_scheme == KTX2_SS_ZSTANDARD)
		{
#if !BASISD_SUPPORT_KTX2_ZSTD
			BASISU_DEVEL_ERROR("ktx2_transcoder::start_transcoding: File uses zstd supercompression, but zstd support was not enabled at compilation time (BASISD_SUPPORT_KTX2_ZSTD == 0)\n");
			return false;
#endif
		}

		return true;
	}

	bool ktx2_transcoder::get_image_level_info(ktx2_image_level_info& level_info, uint32_t level_index, uint32_t layer_index, uint32_t face_index) const
	{
		if (level_index >= m_levels.size())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: level_index >= m_levels.size()\n");
			return false;
		}

		if (m_header.m_face_count > 1)
		{
			if (face_index >= 6)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: face_index >= 6\n");
				return false;
			}
		}
		else if (face_index != 0)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: face_index != 0\n");
			return false;
		}

		if (layer_index >= basisu::maximum<uint32_t>(m_header.m_layer_count, 1))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::get_image_level_info: layer_index >= maximum<uint32_t>(m_header.m_layer_count, 1)\n");
			return false;
		}
				
		const uint32_t level_width = basisu::maximum<uint32_t>(m_header.m_pixel_width >> level_index, 1);
		const uint32_t level_height = basisu::maximum<uint32_t>(m_header.m_pixel_height >> level_index, 1);

		const uint32_t block_width = get_block_width();
		const uint32_t block_height = get_block_height();

		const uint32_t num_blocks_x = (level_width + block_width - 1) / block_width;
		const uint32_t num_blocks_y = (level_height + block_height - 1) / block_height;

		level_info.m_face_index = face_index;
		level_info.m_layer_index = layer_index;
		level_info.m_level_index = level_index;
		level_info.m_orig_width = level_width;
		level_info.m_orig_height = level_height;
		level_info.m_width = num_blocks_x * block_width;
		level_info.m_height = num_blocks_y * block_height;
		level_info.m_block_width = block_width;
		level_info.m_block_height = block_height;
		level_info.m_num_blocks_x = num_blocks_x;
		level_info.m_num_blocks_y = num_blocks_y;
		level_info.m_total_blocks = num_blocks_x * num_blocks_y;
		level_info.m_alpha_flag = m_has_alpha;
		level_info.m_iframe_flag = false;
		
		if (m_etc1s_image_descs.size())
		{
			const uint32_t etc1s_image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;

			level_info.m_iframe_flag = (m_etc1s_image_descs[etc1s_image_index].m_image_flags & KTX2_IMAGE_IS_P_FRAME) == 0;
		}

		return true;
	}
		
	bool ktx2_transcoder::transcode_image_level(
		uint32_t level_index, uint32_t layer_index, uint32_t face_index, 
		void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
		basist::transcoder_texture_format fmt,
		uint32_t decode_flags, uint32_t output_row_pitch_in_blocks_or_pixels, uint32_t output_rows_in_pixels, int channel0, int channel1,
		ktx2_transcoder_state* pState)
	{
		if (!m_pData)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: Must call init() first\n");
			return false;
		}

		if (!pState)
			pState = &m_def_transcoder_state;
										
		if (level_index >= m_levels.size())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: level_index >= m_levels.size()\n");
			return false;
		}

		if (m_header.m_face_count > 1)
		{
			if (face_index >= 6)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: face_index >= 6\n");
				return false;
			}
		}
		else if (face_index != 0)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: face_index != 0\n");
			return false;
		}

		if (layer_index >= basisu::maximum<uint32_t>(m_header.m_layer_count, 1))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: layer_index >= maximum<uint32_t>(m_header.m_layer_count, 1)\n");
			return false;
		}

		const uint8_t* pComp_level_data = m_pData + m_levels[level_index].m_byte_offset.get_uint64();
		uint64_t comp_level_data_size = m_levels[level_index].m_byte_length.get_uint64();
		
		const uint8_t* pUncomp_level_data = pComp_level_data;
		uint64_t uncomp_level_data_size = comp_level_data_size;

		if (uncomp_level_data_size > UINT32_MAX)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: uncomp_level_data_size > UINT32_MAX\n");
			return false;
		}
				
		if (m_header.m_supercompression_scheme == KTX2_SS_ZSTANDARD)
		{
			// Check if we've already decompressed this level's supercompressed data.
			if ((int)level_index != pState->m_uncomp_data_level_index)
			{
				// Uncompress the entire level's supercompressed data.
				if (!decompress_level_data(level_index, pState->m_level_uncomp_data))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: decompress_level_data() failed\n");
					return false;
				}
				pState->m_uncomp_data_level_index = level_index;
			}

			pUncomp_level_data = pState->m_level_uncomp_data.data();
			uncomp_level_data_size = pState->m_level_uncomp_data.size();
		}
				
		const uint32_t level_width = basisu::maximum<uint32_t>(m_header.m_pixel_width >> level_index, 1);
		const uint32_t level_height = basisu::maximum<uint32_t>(m_header.m_pixel_height >> level_index, 1);
		const uint32_t num_blocks4_x = (level_width + 3) >> 2;
		const uint32_t num_blocks4_y = (level_height + 3) >> 2;
		
		if (m_format == basist::basis_tex_format::cETC1S)
		{
			// ETC1S
			// Ensure start_transcoding() was called.
			if (m_etc1s_transcoder.get_endpoints().empty())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: must call start_transcoding() first\n");
				return false;
			}

			const uint32_t etc1s_image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;
		
			// Sanity check
			if (etc1s_image_index >= m_etc1s_image_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: etc1s_image_index >= m_etc1s_image_descs.size()\n");
				return false;
			}

			const ktx2_etc1s_image_desc& image_desc = m_etc1s_image_descs[etc1s_image_index];

			if (!m_etc1s_transcoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, m_pData, m_data_size,
				num_blocks4_x, num_blocks4_y, level_width, level_height,
				level_index,
				m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_rgb_slice_byte_offset, image_desc.m_rgb_slice_byte_length,
				image_desc.m_alpha_slice_byte_length ? (m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_alpha_slice_byte_offset) : 0, image_desc.m_alpha_slice_byte_length,
				decode_flags, m_has_alpha,
				m_is_video, output_row_pitch_in_blocks_or_pixels, &pState->m_transcoder_state, output_rows_in_pixels))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: ETC1S transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}
		}
		else if (m_format == basist::basis_tex_format::cUASTC_HDR_6x6_INTERMEDIATE)
		{
			// UASTC HDR 6x6i
			if (!m_slice_offset_len_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: must call start_transcoding() first\n");
				return false;
			}

			const uint32_t num_blocks6_x = (level_width + 5) / 6;
			const uint32_t num_blocks6_y = (level_height + 5) / 6;

			const uint32_t image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;

			// Sanity check
			if (image_index >= m_slice_offset_len_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: Invalid image_index\n");
				return false;
			}

			const ktx2_slice_offset_len_desc_orig& image_desc = m_slice_offset_len_descs[image_index];
						
			if (!m_astc_hdr_6x6_intermediate_transcoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				m_pData, m_data_size, num_blocks6_x, num_blocks6_y, level_width, level_height, level_index,
				m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_slice_byte_offset, image_desc.m_slice_byte_length,
				decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: ASTC 6x6 HDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}
		}
		else if (m_format == basist::basis_tex_format::cASTC_HDR_6x6)
		{
			// plain ASTC HDR 6x6
			const uint32_t num_blocks6_x = (level_width + 5) / 6;
			const uint32_t num_blocks6_y = (level_height + 5) / 6;

			// Compute length and offset to uncompressed 2D UASTC texture data, given the face/layer indices.
			assert(uncomp_level_data_size == m_levels[level_index].m_uncompressed_byte_length.get_uint64());

			const uint64_t total_2D_image_size = (uint64_t)num_blocks6_x * num_blocks6_y * sizeof(astc_helpers::astc_block);

			const uint64_t uncomp_ofs = (layer_index * m_header.m_face_count + face_index) * total_2D_image_size;

			if ((total_2D_image_size > UINT32_MAX) || ((size_t)uncomp_ofs != uncomp_ofs))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: size too large\n");
				return false;
			}

			// Sanity checks
			if (uncomp_ofs >= uncomp_level_data_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: uncomp_ofs >= total_2D_image_size\n");
				return false;
			}

			if ((uncomp_level_data_size - uncomp_ofs) < total_2D_image_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: (uncomp_level_data_size - uncomp_ofs) < total_2D_image_size\n");
				return false;
			}

			assert(total_2D_image_size <= UINT32_MAX);

			if (!m_astc_hdr_6x6_transcoder.transcode_image(fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pUncomp_level_data + (size_t)uncomp_ofs, (uint32_t)total_2D_image_size, num_blocks6_x, num_blocks6_y, level_width, level_height, level_index,
				0, (uint32_t)total_2D_image_size,
				decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: ASTC 6x6 HDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}
		}
		else if (basis_tex_format_is_astc_ldr(m_format))
		{
			// ASTC LDR 4x4-12x12
			const uint32_t block_width = get_block_width(), block_height = get_block_height();

			if ((decode_flags & (cDecodeFlagsForceDeblockFiltering | cDecodeFlagsNoDeblockFiltering)) == 0)
			{
				// User left deblocking up to us, so let's see if the file enabled it or not.
				if (m_deblocking_filter_index >= 1)
				{
					decode_flags |= cDecodeFlagsForceDeblockFiltering;
				}
				else 
				{
					decode_flags |= cDecodeFlagsNoDeblockFiltering;
				}
			}

			const uint32_t num_blocks_x = (level_width + block_width - 1) / block_width;
			const uint32_t num_blocks_y = (level_height + block_height - 1) / block_height;

			//assert(uncomp_level_data_size == m_levels[level_index].m_uncompressed_byte_length.get_uint64());
			if (uncomp_level_data_size != m_levels[level_index].m_uncompressed_byte_length.get_uint64())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: m_uncompressed_byte_length is invalid\n");
				return false;
			}

			const uint64_t total_2D_image_size = (uint64_t)num_blocks_x * num_blocks_y * sizeof(astc_helpers::astc_block);
			
			const uint64_t uncomp_ofs = (layer_index * m_header.m_face_count + face_index) * total_2D_image_size;

			if ((total_2D_image_size > UINT32_MAX) || ((size_t)uncomp_ofs != uncomp_ofs))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: size too large\n");
				return false;
			}

			// Sanity checks
			if (uncomp_ofs >= uncomp_level_data_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: uncomp_ofs >= total_2D_image_size\n");
				return false;
			}

			if ((uncomp_level_data_size - uncomp_ofs) < total_2D_image_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: (uncomp_level_data_size - uncomp_ofs) < total_2D_image_size\n");
				return false;
			}

			assert(total_2D_image_size <= UINT32_MAX);

			// if the header's vkformat is odd, it's linear, even is sRGB
			const bool uses_astc_src_decode_profile = ((uint32_t)m_header.m_vk_format & 1) == 0;

			if (!m_xuastc_ldr_transcoder.transcode_image(m_format, uses_astc_src_decode_profile, fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				(const uint8_t*)pUncomp_level_data + (size_t)uncomp_ofs, (uint32_t)total_2D_image_size, num_blocks_x, num_blocks_y, level_width, level_height, level_index,
				0, (uint32_t)total_2D_image_size,
				decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: ASTC 6x6 HDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}

		}
		else if (basis_tex_format_is_xuastc_ldr(m_format))
		{
			// XUASTC LDR 4x4-12x12
			if (!m_slice_offset_len_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: must call start_transcoding() first\n");
				return false;
			}

			const uint32_t block_width = get_block_width(), block_height = get_block_height();

			if ((decode_flags & (cDecodeFlagsForceDeblockFiltering | cDecodeFlagsNoDeblockFiltering)) == 0)
			{
				// User left deblocking up to us, so let's see if the file enabled it or not.
				if (m_deblocking_filter_index >= 1)
				{
					decode_flags |= cDecodeFlagsForceDeblockFiltering;
				}
				else
				{
					decode_flags |= cDecodeFlagsNoDeblockFiltering;
				}
			}

			const uint32_t num_blocks_x = (level_width + block_width - 1) / block_width;
			const uint32_t num_blocks_y = (level_height + block_height - 1) / block_height;

			const uint32_t image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;

			// Sanity check
			if (image_index >= m_slice_offset_len_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: Invalid image_index\n");
				return false;
			}

			const ktx2_slice_offset_len_desc_orig& image_desc = m_slice_offset_len_descs[image_index];

			// XUASTC LDR has its own tiny header at the start of the compressed data with this profile bit, so it'll use that for decoding if needed.
			bool uses_astc_src_decode_profile = true;

			if (!m_xuastc_ldr_transcoder.transcode_image(m_format, uses_astc_src_decode_profile, fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				m_pData, m_data_size, num_blocks_x, num_blocks_y, level_width, level_height, level_index,
				m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_slice_byte_offset, image_desc.m_slice_byte_length,
				decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: XUASTC LDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}

		}
		else if ((m_format == basist::basis_tex_format::cUASTC_LDR_4x4) ||
			     (m_format == basist::basis_tex_format::cUASTC_HDR_4x4))
		{
			// UASTC LDR 4x4 and UASTC HDR 4x4
			
			// Compute length and offset to uncompressed 2D UASTC texture data, given the face/layer indices.
			assert(uncomp_level_data_size == m_levels[level_index].m_uncompressed_byte_length.get_uint64());
			const uint64_t total_2D_image_size = (uint64_t)num_blocks4_x * num_blocks4_y * KTX2_UASTC_BLOCK_SIZE;
						
			const uint64_t uncomp_ofs = (layer_index * m_header.m_face_count + face_index) * total_2D_image_size;

			if ((total_2D_image_size > UINT32_MAX) || ((size_t)uncomp_ofs != uncomp_ofs))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: size too large\n");
				return false;
			}

			// Sanity checks
			if (uncomp_ofs >= uncomp_level_data_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: uncomp_ofs >= total_2D_image_size\n");
				return false;
			}

			if ((uncomp_level_data_size - uncomp_ofs) < total_2D_image_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: (uncomp_level_data_size - uncomp_ofs) < total_2D_image_size\n");
				return false;
			}

			assert(total_2D_image_size <= UINT32_MAX);

			if (m_format == basist::basis_tex_format::cUASTC_HDR_4x4)
			{
				// UASTC HDR 4x4
				if (!m_uastc_hdr_transcoder.transcode_image(fmt,
					pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
					(const uint8_t*)pUncomp_level_data + uncomp_ofs, (uint32_t)total_2D_image_size, num_blocks4_x, num_blocks4_y, level_width, level_height, level_index,
					0, (uint32_t)total_2D_image_size,
					decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: UASTC HDR transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
					return false;
				}
			}
			else
			{
				// UASTC LDR 4x4
				if (!m_uastc_ldr_transcoder.transcode_image(fmt,
					pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
					(const uint8_t*)pUncomp_level_data + uncomp_ofs, (uint32_t)total_2D_image_size, num_blocks4_x, num_blocks4_y, level_width, level_height, level_index,
					0, (uint32_t)total_2D_image_size,
					decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: UASTC transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
					return false;
				}
			}
		}
		else if (m_format == basist::basis_tex_format::cXUBC7)
		{
			// XUBC7
			if (!m_slice_offset_len_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: must call start_transcoding() first\n");
				return false;
			}

			const uint32_t block_width = 4, block_height = 4;

			const uint32_t num_blocks_x = (level_width + block_width - 1) / block_width;
			const uint32_t num_blocks_y = (level_height + block_height - 1) / block_height;

			const uint32_t image_index =
				(level_index * basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count) +
				layer_index * m_header.m_face_count +
				face_index;

			// Sanity check
			if (image_index >= m_slice_offset_len_descs.size())
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: Invalid image_index\n");
				return false;
			}

			const ktx2_slice_offset_len_desc_orig& image_desc = m_slice_offset_len_descs[image_index];
						
			if (!m_xubc7_transcoder.transcode_image(m_format, fmt,
				pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels,
				m_pData, m_data_size, num_blocks_x, num_blocks_y, level_width, level_height, level_index,
				m_levels[level_index].m_byte_offset.get_uint64() + image_desc.m_slice_byte_offset, image_desc.m_slice_byte_length,
				decode_flags, m_has_alpha, m_is_video, output_row_pitch_in_blocks_or_pixels, nullptr, output_rows_in_pixels, channel0, channel1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: XUBC7 transcode_image() failed, this is either a bug or the file is corrupted/invalid\n");
				return false;
			}
		}
		else
		{
			// Shouldn't get here.
			BASISU_DEVEL_ERROR("ktx2_transcoder::transcode_image_level: Internal error\n");
			assert(0);
			return false;
		}

		return true;
	}
		
	bool ktx2_transcoder::decompress_level_data(uint32_t level_index, basisu::uint8_vec& uncomp_data)
	{
		const uint8_t* pComp_data = m_levels[level_index].m_byte_offset.get_uint64() + m_pData;
		const uint64_t comp_size = m_levels[level_index].m_byte_length.get_uint64();
						
		const uint64_t uncomp_size = m_levels[level_index].m_uncompressed_byte_length.get_uint64();

		if (((size_t)comp_size) != comp_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Compressed data too large\n");
			return false;
		}
		if (((size_t)uncomp_size) != uncomp_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Uncompressed data too large\n");
			return false;
		}

		if (!uncomp_data.try_resize((size_t)uncomp_size))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Out of memory\n");
			return false;
		}
		
		if (m_header.m_supercompression_scheme == KTX2_SS_ZSTANDARD)
		{
#if BASISD_SUPPORT_KTX2_ZSTD
			size_t actualUncompSize = ZSTD_decompress(uncomp_data.data(), (size_t)uncomp_size, pComp_data, (size_t)comp_size);
			if (ZSTD_isError(actualUncompSize))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Zstd decompression failed, file is invalid or corrupted\n");
				return false;
			}
			if (actualUncompSize != uncomp_size)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: Zstd decompression returned too few bytes, file is invalid or corrupted\n");
				return false;
			}
#else
			BASISU_NOTE_UNUSED(pComp_data);

			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_level_data: File uses Zstd supercompression, but Zstd support was not enabled at compile time (BASISD_SUPPORT_KTX2_ZSTD is 0)\n");
			return false;
#endif
		}

		return true;
	}

	bool ktx2_transcoder::read_slice_offset_len_global_data(bool read_std_structs)
	{
		// m_layer_count (<= KTX2_MAX_SUPPORTED_LAYER_COUNT), m_face_count (1 or 6) and m_level_count (<= KTX2_MAX_SUPPORTED_LEVEL_COUNT) were all validated in init(), so this product is small. Computed in 64-bit anyway as defense in depth against a future limit increase overflowing a uint32_t (or a 32-bit size_t).
		const uint64_t image_count = (uint64_t)basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count * m_header.m_level_count;
		assert(image_count);

		const uint8_t* pSrc = m_pData + m_header.m_sgd_byte_offset.get_uint64();

		// The descriptor array must exactly fill the supercompression global data, whose offset/length were already sanity checked in init() to be inside the file and after the KTX2 header.
		// Validate the expected byte size BEFORE allocating, so an attacker can't force a huge speculative allocation (e.g. via a bogus layer count) that would abort the process. Because m_sgd_byte_length is bounded by the file size, this also bounds image_count.
		const uint64_t desc_size = read_std_structs ? sizeof(ktx2_slice_offset_len_desc_std) : sizeof(ktx2_slice_offset_len_desc_orig);

		if (m_header.m_sgd_byte_length.get_uint64() != image_count * desc_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_slice_offset_len_global_data: Invalid global data length\n");
			return false;
		}

		if (!m_slice_offset_len_descs.try_resize(image_count))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_slice_offset_len_global_data: Out of memory\n");
			return false;
		}

		if (read_std_structs)
		{
			const ktx2_slice_offset_len_desc_std* pSrc_std_descs = reinterpret_cast<const ktx2_slice_offset_len_desc_std*>(pSrc);

			for (uint32_t i = 0; i < image_count; i++)
			{
				// TODO: Ignoring type (profile) for now, but we could check it
				m_slice_offset_len_descs[i].m_slice_byte_offset = pSrc_std_descs[i].m_slice_byte_offset;
				m_slice_offset_len_descs[i].m_slice_byte_length = pSrc_std_descs[i].m_slice_byte_length;
			}
		}
		else
		{
			memcpy((void*)m_slice_offset_len_descs.data(), pSrc, sizeof(ktx2_slice_offset_len_desc_orig) * image_count);
		}

		// Sanity check the image descs
		for (uint32_t i = 0; i < image_count; i++)
		{
			// transcode_image() will validate the slice offsets/lengths before transcoding.

			if (!m_slice_offset_len_descs[i].m_slice_byte_length)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_slice_offset_len_global_data: image descs sanity check failed (1)\n");
				return false;
			}
		}

		return true;
	}
		
	bool ktx2_transcoder::decompress_etc1s_global_data()
	{
		// Note: we don't actually support 3D textures in here yet
		//uint32_t layer_pixel_depth = basisu::maximum<uint32_t>(m_header.m_pixel_depth, 1);
		//for (uint32_t i = 1; i < m_header.m_level_count; i++)
		//	layer_pixel_depth += basisu::maximum<uint32_t>(m_header.m_pixel_depth >> i, 1);

		// m_layer_count (<= KTX2_MAX_SUPPORTED_LAYER_COUNT), m_face_count (1 or 6) and m_level_count (<= KTX2_MAX_SUPPORTED_LEVEL_COUNT) were all validated in init(), so this product is small. Computed in 64-bit anyway as defense in depth against a future limit increase overflowing a uint32_t (or a 32-bit size_t in the size check below).
		const uint64_t image_count = (uint64_t)basisu::maximum<uint32_t>(m_header.m_layer_count, 1) * m_header.m_face_count * m_header.m_level_count;
		assert(image_count);

		const uint8_t* pSrc = m_pData + m_header.m_sgd_byte_offset.get_uint64();

		memcpy((void *)&m_etc1s_header, pSrc, sizeof(ktx2_etc1s_global_data_header));
		pSrc += sizeof(ktx2_etc1s_global_data_header);

		if ((!m_etc1s_header.m_endpoints_byte_length) || (!m_etc1s_header.m_selectors_byte_length) || (!m_etc1s_header.m_tables_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: Invalid ETC1S global data\n");
			return false;
		}

		if ((!m_etc1s_header.m_endpoint_count) || (!m_etc1s_header.m_selector_count))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: endpoint and/or selector count is 0, file is invalid or corrupted\n");
			return false;
		}

		// Sanity check the ETC1S header.
		if ((sizeof(ktx2_etc1s_global_data_header) +
			sizeof(ktx2_etc1s_image_desc) * image_count +
			m_etc1s_header.m_endpoints_byte_length +
			m_etc1s_header.m_selectors_byte_length +
			m_etc1s_header.m_tables_byte_length +
			m_etc1s_header.m_extended_byte_length) > m_header.m_sgd_byte_length.get_uint64())
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: SGD byte length is too small, file is invalid or corrupted\n");
			return false;
		}
				
		if (!m_etc1s_image_descs.try_resize(image_count))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: Out of memory\n");
			return false;
		}
		
		memcpy((void *)m_etc1s_image_descs.data(), pSrc, sizeof(ktx2_etc1s_image_desc) * image_count);
		pSrc += sizeof(ktx2_etc1s_image_desc) * image_count;

		// Sanity check the ETC1S image descs
		for (uint32_t i = 0; i < image_count; i++)
		{
			// m_etc1s_transcoder.transcode_image() will validate the slice offsets/lengths before transcoding.

			if (!m_etc1s_image_descs[i].m_rgb_slice_byte_length)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: ETC1S image descs sanity check failed (1)\n");
				return false;
			}

			if (m_has_alpha)
			{
				if (!m_etc1s_image_descs[i].m_alpha_slice_byte_length)
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: ETC1S image descs sanity check failed (2)\n");
					return false;
				}
			}
		}

		const uint8_t* pEndpoint_data = pSrc;
		const uint8_t* pSelector_data = pSrc + m_etc1s_header.m_endpoints_byte_length;
		const uint8_t* pTables_data = pSrc + m_etc1s_header.m_endpoints_byte_length + m_etc1s_header.m_selectors_byte_length;

		if (!m_etc1s_transcoder.decode_tables(pTables_data, m_etc1s_header.m_tables_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: decode_tables() failed, file is invalid or corrupted\n");
			return false;
		}
				
		if (!m_etc1s_transcoder.decode_palettes(
			m_etc1s_header.m_endpoint_count,	pEndpoint_data, m_etc1s_header.m_endpoints_byte_length,
			m_etc1s_header.m_selector_count,	pSelector_data, m_etc1s_header.m_selectors_byte_length))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::decompress_etc1s_global_data: decode_palettes() failed, file is likely corrupted\n");
			return false;
		}
				
		return true;
	}

	bool ktx2_transcoder::read_key_values()
	{
		if (!m_header.m_kvd_byte_length)
		{
			if (m_header.m_kvd_byte_offset)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Invalid KVD byte offset (it should be zero when the length is zero)\n");
				return false;
			}

			return true;
		}

		if (m_header.m_kvd_byte_offset < sizeof(ktx2_header))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Invalid KVD byte offset\n");
			return false;
		}

		if ((m_header.m_kvd_byte_offset.get_uint64() + m_header.m_kvd_byte_length.get_uint64()) > m_data_size)
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Invalid KVD byte offset and/or length\n");
			return false;
		}

		const uint8_t* pSrc = m_pData + m_header.m_kvd_byte_offset;
		uint32_t src_left = m_header.m_kvd_byte_length;

		if (!m_key_values.try_reserve(8))
		{
			BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
			return false;
		}

		while (src_left > sizeof(uint32_t))
		{
			uint32_t l = basisu::read_le_dword(pSrc);
			
			pSrc += sizeof(uint32_t);
			src_left -= sizeof(uint32_t);

			if (l < 2)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (0)\n");
				return false;
			}

			if (src_left < l)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (1)\n");
				return false;
			}

			if (!m_key_values.try_resize(m_key_values.size() + 1))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}
			
			basisu::uint8_vec& key_data = m_key_values.back().m_key;
			basisu::uint8_vec& value_data = m_key_values.back().m_value;

			do
			{
				if (!l)
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (2)\n");
					return false;
				}

				if (!key_data.try_push_back(*pSrc++))
				{
					BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
					return false;
				}

				src_left--;
				l--;

			} while (key_data.back());

			// Ensure key and value are definitely 0 terminated
			if (!key_data.try_push_back('\0'))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}
						
			if (!value_data.try_resize(l))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}

			if (l)
			{
				memcpy(value_data.data(), pSrc, l);
				pSrc += l;
				src_left -= l;
			}

			// Ensure key and value are definitely 0 terminated
			if (!value_data.try_push_back('\0'))
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Out of memory\n");
				return false;
			}

			uint32_t ofs = (uint32_t)(pSrc - m_pData) & 3;
			uint32_t alignment_bytes = (4 - ofs) & 3;

			if (src_left < alignment_bytes)
			{
				BASISU_DEVEL_ERROR("ktx2_transcoder::read_key_values: Failed reading key value fields (3)\n");
				return false;
			}

			pSrc += alignment_bytes;
			src_left -= alignment_bytes;
		}

		return true;
	}
		
#endif // BASISD_SUPPORT_KTX2

	bool basisu_transcoder_supports_ktx2()
	{
#if BASISD_SUPPORT_KTX2
		return true;
#else
		return false;
#endif
	}

	bool basisu_transcoder_supports_ktx2_zstd()
	{
#if BASISD_SUPPORT_KTX2_ZSTD
		return true;
#else
		return false;
#endif
	}

	//-------------------------------

#if BASISD_SUPPORT_UASTC_HDR
	// This float->half conversion matches how "F32TO16" works on Intel GPU's.
	basist::half_float float_to_half(float val)
	{
		union { float f; int32_t i; uint32_t u; } fi = { val };
		const int flt_m = fi.i & 0x7FFFFF, flt_e = (fi.i >> 23) & 0xFF, flt_s = (fi.i >> 31) & 0x1;
		int s = flt_s, e = 0, m = 0;

		// inf/NaN
		if (flt_e == 0xff)
		{
			e = 31;
			if (flt_m != 0) // NaN
				m = 1;
		}
		// not zero or denormal
		else if (flt_e != 0)
		{
			int new_exp = flt_e - 127;
			if (new_exp > 15)
				e = 31;
			else if (new_exp < -14)
				m = (int)lrintf((1 << 24) * fabsf(fi.f));
			else
			{
				e = new_exp + 15;
				m = (int)lrintf(flt_m * (1.0f / ((float)(1 << 13))));
			}
		}

		assert((0 <= m) && (m <= 1024));
		if (m == 1024)
		{
			e++;
			m = 0;
		}

		assert((s >= 0) && (s <= 1));
		assert((e >= 0) && (e <= 31));
		assert((m >= 0) && (m <= 1023));

		basist::half_float result = (basist::half_float)((s << 15) | (e << 10) | m);
		return result;
	}
		
	//------------------------------------------------------------------------------------------------
	// HDR support
	// 
	// Originally from bc6h_enc.cpp
	// BC6H decoder fuzzed vs. DirectXTex's for unsigned/signed

	const uint8_t g_bc6h_mode_sig_bits[NUM_BC6H_MODES][4] = // base bits, r, g, b
	{
		// 2 subsets
		{ 10, 5, 5, 5, },	// 0, mode 1 in MS/D3D docs
		{ 7, 6, 6, 6, },	// 1
		{ 11, 5, 4, 4, },	// 2
		{ 11, 4, 5, 4, },	// 3
		{ 11, 4, 4, 5, },	// 4
		{ 9, 5, 5, 5, },	// 5
		{ 8, 6, 5, 5, },	// 6
		{ 8, 5, 6, 5, },	// 7
		{ 8, 5, 5, 6, },	// 8
		{ 6, 6, 6, 6, },	// 9, endpoints not delta encoded, mode 10 in MS/D3D docs
		// 1 subset
		{ 10, 10, 10, 10, }, // 10, endpoints not delta encoded, mode 11 in MS/D3D docs
		{ 11, 9, 9, 9, },	// 11
		{ 12, 8, 8, 8, },	// 12
		{ 16, 4, 4, 4, }	// 13, also useful for solid blocks
	};

	const int8_t g_bc6h_mode_lookup[32] = { 0, 1, 2, 10, 0, 1, 3, 11, 0, 1, 4, 12, 0, 1, 5, 13, 0, 1, 6, -1, 0, 1, 7, -1, 0, 1, 8, -1, 0, 1, 9, -1 };

	const bc6h_bit_layout g_bc6h_bit_layouts[NUM_BC6H_MODES][MAX_BC6H_LAYOUT_INDEX] =
	{
		// comp_index, subset*2+lh_index, last_bit, first_bit
		//------------------------        mode 0: 2 subsets, Weight bits: 46 bits, Endpoint bits: 75 bits (10.555, 10.555, 10.555), delta            
		{ { 1, 2, 4, -1 }, { 2, 2, 4, -1 }, { 2, 3, 4, -1 }, { 0, 0, 9, 0 }, { 1, 0, 9, 0 }, { 2, 0, 9, 0 }, { 0, 1, 4, 0 },
		{ 1, 3, 4, -1 }, { 1, 2, 3, 0 }, { 1, 1, 4, 0 }, { 2, 3, 0, -1 }, { 1, 3, 3, 0 }, { 2, 1, 4, 0 }, { 2, 3, 1, -1 },
		{ 2, 2, 3, 0 }, { 0, 2, 4, 0 }, { 2, 3, 2, -1 }, { 0, 3, 4, 0 }, { 2, 3, 3, -1 }, { 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 1: 2 subsets, Weight bits: 46 bits, Endpoint bits: 75 bits (7.666, 7.666, 7.666), delta
		{ { 1, 2, 5, -1 },{ 1, 3, 4, -1 },{ 1, 3, 5, -1 },{ 0, 0, 6, 0 },{ 2, 3, 0, -1 },{ 2, 3, 1, -1 },{ 2, 2, 4, -1 },
		{ 1, 0, 6, 0 },{ 2, 2, 5, -1 },{ 2, 3, 2, -1 },{ 1, 2, 4, -1 },{ 2, 0, 6, 0 },{ 2, 3, 3, -1 },{ 2, 3, 5, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 5, 0 },{ 1, 2, 3, 0 },{ 1, 1, 5, 0 },{ 1, 3, 3, 0 },{ 2, 1, 5, 0 },{ 2, 2, 3, 0 },{ 0, 2, 5, 0 },
		{ 0, 3, 5, 0 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 2: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (11.555, 11.444, 11.444), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 4, 0 },{ 0, 0, 10, -1 },{ 1, 2, 3, 0 },{ 1, 1, 3, 0 },{ 1, 0, 10, -1 },
		{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 3, 0 },{ 2, 0, 10, -1 },{ 2, 3, 1, -1 },{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },{ 2, 3, 2, -1 },
		{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 3: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (11.444, 11.555, 11.444), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 3, 0 },{ 0, 0, 10, -1 },{ 1, 3, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },
		{ 1, 0, 10, -1 },{ 1, 3, 3, 0 },{ 2, 1, 3, 0 },{ 2, 0, 10, -1 },{ 2, 3, 1, -1 },{ 2, 2, 3, 0 },{ 0, 2, 3, 0 },{ 2, 3, 0, -1 },
		{ 2, 3, 2, -1 },{ 0, 3, 3, 0 },{ 1, 2, 4, -1 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 4: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (11.444, 11.444, 11.555), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 3, 0 },{ 0, 0, 10, -1 },{ 2, 2, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 3, 0 },
		{ 1, 0, 10, -1 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 0, 10, -1 },{ 2, 2, 3, 0 },{ 0, 2, 3, 0 },{ 2, 3, 1, -1 },
		{ 2, 3, 2, -1 },{ 0, 3, 3, 0 },{ 2, 3, 4, -1 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 5: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (9.555, 9.555, 9.555), delta
		{ { 0, 0, 8, 0 },{ 2, 2, 4, -1 },{ 1, 0, 8, 0 },{ 1, 2, 4, -1 },{ 2, 0, 8, 0 },{ 2, 3, 4, -1 },{ 0, 1, 4, 0 },{ 1, 3, 4, -1 },
		{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 3, 1, -1 },{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },
		{ 2, 3, 2, -1 },{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 6: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (8.666, 8.555, 8.555), delta
		{ { 0, 0, 7, 0 },{ 1, 3, 4, -1 },{ 2, 2, 4, -1 },{ 1, 0, 7, 0 },{ 2, 3, 2, -1 },{ 1, 2, 4, -1 },{ 2, 0, 7, 0 },{ 2, 3, 3, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 5, 0 },{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 3, 1, -1 },
		{ 2, 2, 3, 0 },{ 0, 2, 5, 0 },{ 0, 3, 5, 0 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 7: 2 subsets, Weight bits: 46 bits, Endpoints bits: 72 bits (8.555, 8.666, 8.555), delta
		{ { 0, 0, 7, 0 },{ 2, 3, 0, -1 },{ 2, 2, 4, -1 },{ 1, 0, 7, 0 },{ 1, 2, 5, -1 },{ 1, 2, 4, -1 },{ 2, 0, 7, 0 },{ 1, 3, 5, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 4, 0 },{ 1, 3, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 5, 0 },{ 1, 3, 3, 0 },{ 2, 1, 4, 0 },{ 2, 3, 1, -1 },
		{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },{ 2, 3, 2, -1 },{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 8: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (8.555, 8.555, 8.666), delta
		{ { 0, 0, 7, 0 },{ 2, 3, 1, -1 },{ 2, 2, 4, -1 },{ 1, 0, 7, 0 },{ 2, 2, 5, -1 },{ 1, 2, 4, -1 },{ 2, 0, 7, 0 },{ 2, 3, 5, -1 },
		{ 2, 3, 4, -1 },{ 0, 1, 4, 0 },{ 1, 3, 4, -1 },{ 1, 2, 3, 0 },{ 1, 1, 4, 0 },{ 2, 3, 0, -1 },{ 1, 3, 3, 0 },{ 2, 1, 5, 0 },
		{ 2, 2, 3, 0 },{ 0, 2, 4, 0 },{ 2, 3, 2, -1 },{ 0, 3, 4, 0 },{ 2, 3, 3, -1 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 9: 2 subsets, Weight bits: 46 bits, Endpoint bits: 72 bits (6.6.6.6, 6.6.6.6, 6.6.6.6), NO delta
		{ { 0, 0, 5, 0 },{ 1, 3, 4, -1 },{ 2, 3, 0, -1 },{ 2, 3, 1, -1 },{ 2, 2, 4, -1 },{ 1, 0, 5, 0 },{ 1, 2, 5, -1 },{ 2, 2, 5, -1 },
		{ 2, 3, 2, -1 },{ 1, 2, 4, -1 },{ 2, 0, 5, 0 },{ 1, 3, 5, -1 },{ 2, 3, 3, -1 },{ 2, 3, 5, -1 },{ 2, 3, 4, -1 },{ 0, 1, 5, 0 },
		{ 1, 2, 3, 0 },{ 1, 1, 5, 0 },{ 1, 3, 3, 0 },{ 2, 1, 5, 0 },{ 2, 2, 3, 0 },{ 0, 2, 5, 0 },{ 0, 3, 5, 0 },{ 3, -1, 4, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 10: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (10.10, 10.10, 10.10), NO delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 9, 0 },{ 1, 1, 9, 0 },{ 2, 1, 9, 0 }, {-1, 0, 0, 0} },
		//------------------------        mode 11: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (11.9, 11.9, 11.9), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 8, 0 },{ 0, 0, 10, -1 },{ 1, 1, 8, 0 },{ 1, 0, 10, -1 },{ 2, 1, 8, 0 },{ 2, 0, 10, -1 }, {-1, 0, 0, 0} },
		//------------------------        mode 12: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (12.8, 12.8, 12.8), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 7, 0 },{ 0, 0, 10, 11 },{ 1, 1, 7, 0 },{ 1, 0, 10, 11 },{ 2, 1, 7, 0 },{ 2, 0, 10, 11 }, {-1, 0, 0, 0} },
		//------------------------        mode 13: 1 subset, Weight bits: 63 bits, Endpoint bits: 60 bits (16.4, 16.4, 16.4), delta
		{ { 0, 0, 9, 0 },{ 1, 0, 9, 0 },{ 2, 0, 9, 0 },{ 0, 1, 3, 0 },{ 0, 0, 10, 15 },{ 1, 1, 3, 0 },{ 1, 0, 10, 15 },{ 2, 1, 3, 0 },{ 2, 0, 10, 15 }, {-1, 0, 0, 0} }
	};

	// The same as the first 32 2-subset patterns in BC7. 
	// Bit 7 is a flag indicating that the weight uses 1 less bit than usual.
	const uint8_t g_bc6h_2subset_patterns[TOTAL_BC6H_PARTITION_PATTERNS][4][4] = // [pat][y][x]
	{
		{ {0x80, 0, 1, 1}, { 0, 0, 1, 1 }, { 0, 0, 1, 1 }, { 0, 0, 1, 0x81 }}, { {0x80, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 0, 0x81} },
		{ {0x80, 1, 1, 1}, {0, 1, 1, 1}, {0, 1, 1, 1}, {0, 1, 1, 0x81} }, { {0x80, 0, 0, 1}, {0, 0, 1, 1}, {0, 0, 1, 1}, {0, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 1, 0x81} }, { {0x80, 0, 1, 1}, {0, 1, 1, 1}, {0, 1, 1, 1}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 1}, {0, 0, 1, 1}, {0, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 1, 1}, {0, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 1, 0x81} }, { {0x80, 0, 1, 1}, {0, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 1}, {0, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 1}, {0, 1, 1, 0x81} },
		{ {0x80, 0, 0, 1}, {0, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 0}, {1, 1, 1, 1}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 0x81} }, { {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {1, 1, 1, 0x81} },
		{ {0x80, 0, 0, 0}, {1, 0, 0, 0}, {1, 1, 1, 0}, {1, 1, 1, 0x81} }, { {0x80, 1, 0x81, 1}, {0, 0, 0, 1}, {0, 0, 0, 0}, {0, 0, 0, 0} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0x81, 0, 0, 0}, {1, 1, 1, 0} }, { {0x80, 1, 0x81, 1}, {0, 0, 1, 1}, {0, 0, 0, 1}, {0, 0, 0, 0} },
		{ {0x80, 0, 0x81, 1}, {0, 0, 0, 1}, {0, 0, 0, 0}, {0, 0, 0, 0} }, { {0x80, 0, 0, 0}, {1, 0, 0, 0}, {0x81, 1, 0, 0}, {1, 1, 1, 0} },
		{ {0x80, 0, 0, 0}, {0, 0, 0, 0}, {0x81, 0, 0, 0}, {1, 1, 0, 0} }, { {0x80, 1, 1, 1}, {0, 0, 1, 1}, {  0, 0, 1, 1}, {0, 0, 0, 0x81} },
		{ {0x80, 0, 0x81, 1}, {0, 0, 0, 1}, {0, 0, 0, 1}, {0, 0, 0, 0} }, { {0x80, 0, 0, 0}, {1, 0, 0, 0}, {0x81, 0, 0, 0}, {1, 1, 0, 0} },
		{ {0x80, 1, 0x81, 0}, {0, 1, 1, 0}, {0, 1, 1, 0}, {0, 1, 1, 0} }, { {0x80, 0, 0x81, 1}, {0, 1, 1, 0}, {0, 1, 1, 0}, {1, 1, 0, 0} },
		{ {0x80, 0, 0, 1}, {0, 1, 1, 1}, {0x81, 1, 1, 0}, {1, 0, 0, 0} }, { {0x80, 0, 0, 0}, {1, 1, 1, 1}, {0x81, 1, 1, 1}, {0, 0, 0, 0} },
		{ {0x80, 1, 0x81, 1}, {0, 0, 0, 1}, {1, 0, 0, 0}, {1, 1, 1, 0} }, { {0x80, 0, 0x81, 1}, {1, 0, 0, 1}, {1, 0, 0, 1}, {1, 1, 0, 0} }
	};

	const uint8_t g_bc6h_weight3[8] = { 0, 9, 18, 27, 37, 46, 55, 64 };
	const uint8_t g_bc6h_weight4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
	
	static inline void write_bits(uint64_t val, uint32_t num_bits, uint32_t& bit_pos, uint64_t& l, uint64_t& h)
	{
		assert((num_bits) && (num_bits < 64) && (bit_pos < 128));
		assert(val < (1ULL << num_bits));

		if (bit_pos < 64)
		{
			l |= (val << bit_pos);

			if ((bit_pos + num_bits) > 64)
				h |= (val >> (64 - bit_pos));
		}
		else
		{
			h |= (val << (bit_pos - 64));
		}

		bit_pos += num_bits;
		assert(bit_pos <= 128);
	}

	static inline void write_rev_bits(uint64_t val, uint32_t num_bits, uint32_t& bit_pos, uint64_t& l, uint64_t& h)
	{
		assert((num_bits) && (num_bits < 64) && (bit_pos < 128));
		assert(val < (1ULL << num_bits));

		for (uint32_t i = 0; i < num_bits; i++)
			write_bits((val >> (num_bits - 1u - i)) & 1, 1, bit_pos, l, h);
	}

	void pack_bc6h_block(bc6h_block& dst_blk, bc6h_logical_block& log_blk)
	{
		const uint8_t s_mode_bits[NUM_BC6H_MODES] = { 0b00, 0b01, 0b00010, 0b00110, 0b01010, 0b01110, 0b10010, 0b10110, 0b11010, 0b11110, 0b00011, 0b00111, 0b01011, 0b01111 };

		const uint32_t mode = log_blk.m_mode;
		assert(mode < NUM_BC6H_MODES);

		uint64_t l = s_mode_bits[mode], h = 0;
		uint32_t bit_pos = (mode >= 2) ? 5 : 2;

		const uint32_t num_subsets = (mode >= BC6H_FIRST_1SUBSET_MODE_INDEX) ? 1 : 2;

		assert(((num_subsets == 2) && (log_blk.m_partition_pattern < TOTAL_BC6H_PARTITION_PATTERNS)) ||
			((num_subsets == 1) && (!log_blk.m_partition_pattern)));

		// Sanity checks
		for (uint32_t c = 0; c < 3; c++)
		{
			assert(log_blk.m_endpoints[c][0] < (1u << g_bc6h_mode_sig_bits[mode][0]));	   // 1st subset l, base bits
			assert(log_blk.m_endpoints[c][1] < (1u << g_bc6h_mode_sig_bits[mode][c + 1])); // 1st subset h, these are deltas except for modes 9,10
			assert(log_blk.m_endpoints[c][2] < (1u << g_bc6h_mode_sig_bits[mode][c + 1])); // 2nd subset l
			assert(log_blk.m_endpoints[c][3] < (1u << g_bc6h_mode_sig_bits[mode][c + 1])); // 2nd subset h
		}

		const bc6h_bit_layout* pLayout = &g_bc6h_bit_layouts[mode][0];

		while (pLayout->m_comp != -1)
		{
			uint32_t v = (pLayout->m_comp == 3) ? log_blk.m_partition_pattern : log_blk.m_endpoints[pLayout->m_comp][pLayout->m_index];

			if (pLayout->m_first_bit == -1)
			{
				write_bits((v >> pLayout->m_last_bit) & 1, 1, bit_pos, l, h);
			}
			else
			{
				const uint32_t total_bits = basisu::iabs(pLayout->m_last_bit - pLayout->m_first_bit) + 1;

				v >>= basisu::minimum(pLayout->m_first_bit, pLayout->m_last_bit);
				v &= ((1 << total_bits) - 1);

				if (pLayout->m_first_bit > pLayout->m_last_bit)
					write_rev_bits(v, total_bits, bit_pos, l, h);
				else
					write_bits(v, total_bits, bit_pos, l, h);
			}

			pLayout++;
		}

		const uint32_t num_mode_sel_bits = (num_subsets == 1) ? 4 : 3;
		const uint8_t* pPat = &g_bc6h_2subset_patterns[log_blk.m_partition_pattern][0][0];

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t sel = log_blk.m_weights[i];

			uint32_t num_bits = num_mode_sel_bits;
			if (num_subsets == 2)
			{
				const uint32_t subset_index = pPat[i];
				num_bits -= (subset_index >> 7);
			}
			else if (!i)
			{
				num_bits--;
			}

			assert(sel < (1u << num_bits));

			write_bits(sel, num_bits, bit_pos, l, h);
		}

		assert(bit_pos == 128);

		basisu::write_le_dword(&dst_blk.m_bytes[0], (uint32_t)l);
		basisu::write_le_dword(&dst_blk.m_bytes[4], (uint32_t)(l >> 32u));
		basisu::write_le_dword(&dst_blk.m_bytes[8], (uint32_t)h);
		basisu::write_le_dword(&dst_blk.m_bytes[12], (uint32_t)(h >> 32u));
	}

#if 0
	static inline uint32_t bc6h_blog_dequantize_to_blog16(uint32_t comp, uint32_t bits_per_comp)
	{
		int unq;

		if (bits_per_comp >= 15)
			unq = comp;
		else if (comp == 0)
			unq = 0;
		else if (comp == ((1u << bits_per_comp) - 1u))
			unq = 0xFFFFu;
		else
			unq = ((comp << 16u) + 0x8000u) >> bits_per_comp;

		return unq;
	}
#endif
		
	// 6,7,8,9,10,11,12
	const uint32_t BC6H_BLOG_TAB_MIN = 6;
	const uint32_t BC6H_BLOG_TAB_MAX = 12;
	//const uint32_t BC6H_BLOG_TAB_NUM = BC6H_BLOG_TAB_MAX - BC6H_BLOG_TAB_MIN + 1;
	
	// Handles 16, or 6-12 bits. Others assert.
	static inline uint32_t half_to_blog_tab(half_float h, uint32_t num_bits)
	{
		BASISU_NOTE_UNUSED(BC6H_BLOG_TAB_MIN);
		BASISU_NOTE_UNUSED(BC6H_BLOG_TAB_MAX);

		assert(h <= MAX_BC6H_HALF_FLOAT_AS_UINT);
		assert((num_bits == 16) || ((num_bits >= BC6H_BLOG_TAB_MIN) && (num_bits <= BC6H_BLOG_TAB_MAX)));

		return bc6h_half_to_blog(h, num_bits);
#if 0
		BASISU_NOTE_UNUSED(BC6H_BLOG_TAB_MIN);
		BASISU_NOTE_UNUSED(BC6H_BLOG_TAB_MAX);

		if (num_bits == 16)
		{
			return bc6h_half_to_blog(h, 16);
		}
		else
		{
			assert((num_bits >= BC6H_BLOG_TAB_MIN) && (num_bits <= BC6H_BLOG_TAB_MAX));
			
			// Note: This used to be done using a table lookup, but it required ~224KB of tables. This isn't quite as accurate, but the error is very slight (+-1 half values as ints).
			return bc6h_half_to_blog(h, num_bits);
		}
#endif
	}

	bool g_bc6h_enc_initialized;

	void bc6h_enc_init()
	{
		if (g_bc6h_enc_initialized)
			return;

		g_bc6h_enc_initialized = true;
	}

	// mode 10, 4-bit weights
	void bc6h_enc_block_mode10(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 15);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		// Convert half endpoints to blog10 (mode 10 doesn't use delta encoding)
		for (uint32_t c = 0; c < 3; c++)
		{
			log_blk.m_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], 10);
			log_blk.m_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], 10);
		}

		memcpy(log_blk.m_weights, pWeights, 16);

		if (log_blk.m_weights[0] & 8)
		{
			for (uint32_t i = 0; i < 16; i++)
				log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

			for (uint32_t c = 0; c < 3; c++)
			{
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);
			}
		}

		log_blk.m_mode = BC6H_FIRST_1SUBSET_MODE_INDEX;
		pack_bc6h_block(*pPacked_block, log_blk);
	}

	// Tries modes 11-13 (delta endpoint) encoding, falling back to mode 10 only when necessary, 4-bit weights
	void bc6h_enc_block_1subset_4bit_weights(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 15);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		for (uint32_t mode = BC6H_LAST_MODE_INDEX; mode > BC6H_FIRST_1SUBSET_MODE_INDEX; mode--)
		{
			const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0], num_delta_bits = g_bc6h_mode_sig_bits[mode][1];
			const int base_bitmask = (1 << num_base_bits) - 1;
			const int delta_bitmask = (1 << num_delta_bits) - 1;
			BASISU_NOTE_UNUSED(base_bitmask);

			assert(num_delta_bits < num_base_bits);
			assert((num_delta_bits == g_bc6h_mode_sig_bits[mode][2]) && (num_delta_bits == g_bc6h_mode_sig_bits[mode][3]));

			uint32_t blog_endpoints[3][2];

			// Convert half endpoints to blog 16, 12, or 11
			for (uint32_t c = 0; c < 3; c++)
			{
				blog_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], num_base_bits);
				assert((int)blog_endpoints[c][0] <= base_bitmask);

				blog_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], num_base_bits);
				assert((int)blog_endpoints[c][1] <= base_bitmask);
			}

			// Copy weights
			memcpy(log_blk.m_weights, pWeights, 16);

			// Ensure first weight MSB is 0
			if (log_blk.m_weights[0] & 8)
			{
				// Invert weights
				for (uint32_t i = 0; i < 16; i++)
					log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

				// Swap blog quantized endpoints
				for (uint32_t c = 0; c < 3; c++)
				{
					std::swap(blog_endpoints[c][0], blog_endpoints[c][1]);
				}
			}

			const int max_delta = (1 << (num_delta_bits - 1)) - 1;
			const int min_delta = -(max_delta + 1);
			assert((max_delta - min_delta) == delta_bitmask);

			bool failed_flag = false;
			for (uint32_t c = 0; c < 3; c++)
			{
				log_blk.m_endpoints[c][0] = blog_endpoints[c][0];

				int delta = (int)blog_endpoints[c][1] - (int)blog_endpoints[c][0];
				if ((delta < min_delta) || (delta > max_delta))
				{
					failed_flag = true;
					break;
				}

				log_blk.m_endpoints[c][1] = delta & delta_bitmask;
			}

			if (failed_flag)
				continue;

			log_blk.m_mode = mode;
			pack_bc6h_block(*pPacked_block, log_blk);
						
			return;
		}

		// Worst case fall back to mode 10, which can handle any endpoints
		bc6h_enc_block_mode10(pPacked_block, pEndpoints, pWeights);
	}

	// Mode 9 (direct endpoint encoding), 3-bit weights, but only 1 subset
	void bc6h_enc_block_1subset_mode9_3bit_weights(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		// Convert half endpoints to blog6 (mode 9 doesn't use delta encoding)
		for (uint32_t c = 0; c < 3; c++)
		{
			log_blk.m_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], 6);
			log_blk.m_endpoints[c][2] = log_blk.m_endpoints[c][0];

			log_blk.m_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], 6);
			log_blk.m_endpoints[c][3] = log_blk.m_endpoints[c][1];
		}

		memcpy(log_blk.m_weights, pWeights, 16);

		const uint32_t pat_index = 0;
		const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

		if (log_blk.m_weights[0] & 4)
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 0)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		if (log_blk.m_weights[15] & 4)
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][2], log_blk.m_endpoints[c][3]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 1)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		log_blk.m_mode = 9;
		log_blk.m_partition_pattern = pat_index;
		pack_bc6h_block(*pPacked_block, log_blk);
	}

	// Tries modes 0-8, falls back to mode 9
	void bc6h_enc_block_1subset_3bit_weights(bc6h_block* pPacked_block, const half_float pEndpoints[3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		for (uint32_t mode_iter = 0; mode_iter <= 8; mode_iter++)
		{
			static const int s_mode_order[9] = { 2, 3, 4, 0,  5, 6, 7, 8,  1 }; // ordered from largest base bits to least
			const uint32_t mode = s_mode_order[mode_iter];

			const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0];
			const int base_bitmask = (1 << num_base_bits) - 1;
			BASISU_NOTE_UNUSED(base_bitmask);

			const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[mode][1], g_bc6h_mode_sig_bits[mode][2], g_bc6h_mode_sig_bits[mode][3] };
			const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

			uint32_t blog_endpoints[3][4];

			// Convert half endpoints to blog 7-11
			for (uint32_t c = 0; c < 3; c++)
			{
				blog_endpoints[c][0] = half_to_blog_tab(pEndpoints[c][0], num_base_bits);
				blog_endpoints[c][2] = blog_endpoints[c][0];
				assert((int)blog_endpoints[c][0] <= base_bitmask);

				blog_endpoints[c][1] = half_to_blog_tab(pEndpoints[c][1], num_base_bits);
				blog_endpoints[c][3] = blog_endpoints[c][1];
				assert((int)blog_endpoints[c][1] <= base_bitmask);
			}

			const uint32_t pat_index = 0;
			const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

			memcpy(log_blk.m_weights, pWeights, 16);

			if (log_blk.m_weights[0] & 4)
			{
				// Swap part 0's endpoints/weights
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][0], blog_endpoints[c][1]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 0)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			if (log_blk.m_weights[15] & 4)
			{
				// Swap part 1's endpoints/weights
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][2], blog_endpoints[c][3]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 1)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			bool failed_flag = false;

			for (uint32_t c = 0; c < 3; c++)
			{
				const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;

				const int min_delta = -(max_delta + 1);
				assert((max_delta - min_delta) == delta_bitmasks[c]);

				log_blk.m_endpoints[c][0] = blog_endpoints[c][0];

				int delta0 = (int)blog_endpoints[c][1] - (int)blog_endpoints[c][0];
				int delta1 = (int)blog_endpoints[c][2] - (int)blog_endpoints[c][0];
				int delta2 = (int)blog_endpoints[c][3] - (int)blog_endpoints[c][0];

				if ((delta0 < min_delta) || (delta0 > max_delta) ||
					(delta1 < min_delta) || (delta1 > max_delta) ||
					(delta2 < min_delta) || (delta2 > max_delta))
				{
					failed_flag = true;
					break;
				}

				log_blk.m_endpoints[c][1] = delta0 & delta_bitmasks[c];
				log_blk.m_endpoints[c][2] = delta1 & delta_bitmasks[c];
				log_blk.m_endpoints[c][3] = delta2 & delta_bitmasks[c];
			}

			if (failed_flag)
				continue;

			log_blk.m_mode = mode;
			log_blk.m_partition_pattern = pat_index;
			pack_bc6h_block(*pPacked_block, log_blk);

			return;

		} // mode_iter

		bc6h_enc_block_1subset_mode9_3bit_weights(pPacked_block, pEndpoints, pWeights);
	}

	// pEndpoints[subset][comp][lh_index]
	void bc6h_enc_block_2subset_mode9_3bit_weights(bc6h_block* pPacked_block, uint32_t common_part_index, const half_float pEndpoints[2][3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);
		assert(common_part_index < basist::TOTAL_ASTC_BC7_COMMON_PARTITIONS2);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		// Convert half endpoints to blog6 (mode 9 doesn't use delta encoding)
		for (uint32_t s = 0; s < 2; s++)
		{
			for (uint32_t c = 0; c < 3; c++)
			{
				log_blk.m_endpoints[c][0 + s * 2] = half_to_blog_tab(pEndpoints[s][c][0], 6);
				log_blk.m_endpoints[c][1 + s * 2] = half_to_blog_tab(pEndpoints[s][c][1], 6);
			}
		}

		memcpy(log_blk.m_weights, pWeights, 16);

		//const uint32_t astc_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_astc;
		const uint32_t bc7_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_bc7;

		const bool invert_flag = basist::g_astc_bc7_common_partitions2[common_part_index].m_invert;
		if (invert_flag)
		{
			for (uint32_t c = 0; c < 3; c++)
			{
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][2]);
				std::swap(log_blk.m_endpoints[c][1], log_blk.m_endpoints[c][3]);
			}
		}

		const uint32_t pat_index = bc7_pattern;
		assert(pat_index < 32);
		const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

		bool swap_flags[2] = { false, false };
		for (uint32_t i = 0; i < 16; i++)
		{
			if ((pPat[i] & 0x80) == 0)
				continue;

			if (log_blk.m_weights[i] & 4)
			{
				const uint32_t p = pPat[i] & 1;
				swap_flags[p] = true;
			}
		}

		if (swap_flags[0])
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 0)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		if (swap_flags[1])
		{
			for (uint32_t c = 0; c < 3; c++)
				std::swap(log_blk.m_endpoints[c][2], log_blk.m_endpoints[c][3]);

			for (uint32_t i = 0; i < 16; i++)
				if ((pPat[i] & 0x7F) == 1)
					log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
		}

		log_blk.m_mode = 9;
		log_blk.m_partition_pattern = pat_index;
		pack_bc6h_block(*pPacked_block, log_blk);
	}

	void bc6h_enc_block_2subset_3bit_weights(bc6h_block* pPacked_block, uint32_t common_part_index, const half_float pEndpoints[2][3][2], const uint8_t* pWeights)
	{
		assert(g_bc6h_enc_initialized);

		for (uint32_t i = 0; i < 16; i++)
		{
			assert(pWeights[i] <= 7);
		}

		bc6h_logical_block log_blk;
		log_blk.clear();

		for (uint32_t mode_iter = 0; mode_iter <= 8; mode_iter++)
		{
			static const int s_mode_order[9] = { 2, 3, 4, 0,  5, 6, 7, 8,  1 }; // ordered from largest base bits to least
			const uint32_t mode = s_mode_order[mode_iter];

			const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0];
			const int base_bitmask = (1 << num_base_bits) - 1;
			BASISU_NOTE_UNUSED(base_bitmask);

			const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[mode][1], g_bc6h_mode_sig_bits[mode][2], g_bc6h_mode_sig_bits[mode][3] };
			const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

			uint32_t blog_endpoints[3][4];

			// Convert half endpoints to blog 7-11
			for (uint32_t s = 0; s < 2; s++)
			{
				for (uint32_t c = 0; c < 3; c++)
				{
					blog_endpoints[c][0 + s * 2] = half_to_blog_tab(pEndpoints[s][c][0], num_base_bits);
					blog_endpoints[c][1 + s * 2] = half_to_blog_tab(pEndpoints[s][c][1], num_base_bits);
				}
			}

			memcpy(log_blk.m_weights, pWeights, 16);

			//const uint32_t astc_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_astc;
			const uint32_t bc7_pattern = basist::g_astc_bc7_common_partitions2[common_part_index].m_bc7;

			const bool invert_flag = basist::g_astc_bc7_common_partitions2[common_part_index].m_invert;
			if (invert_flag)
			{
				for (uint32_t c = 0; c < 3; c++)
				{
					std::swap(blog_endpoints[c][0], blog_endpoints[c][2]);
					std::swap(blog_endpoints[c][1], blog_endpoints[c][3]);
				}
			}

			const uint32_t pat_index = bc7_pattern;
			assert(pat_index < 32);
			const uint8_t* pPat = &g_bc6h_2subset_patterns[pat_index][0][0];

			bool swap_flags[2] = { false, false };
			for (uint32_t i = 0; i < 16; i++)
			{
				if ((pPat[i] & 0x80) == 0)
					continue;

				if (log_blk.m_weights[i] & 4)
				{
					const uint32_t p = pPat[i] & 1;
					swap_flags[p] = true;
				}
			}

			if (swap_flags[0])
			{
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][0], blog_endpoints[c][1]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 0)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			if (swap_flags[1])
			{
				for (uint32_t c = 0; c < 3; c++)
					std::swap(blog_endpoints[c][2], blog_endpoints[c][3]);

				for (uint32_t i = 0; i < 16; i++)
					if ((pPat[i] & 0x7F) == 1)
						log_blk.m_weights[i] = 7 - log_blk.m_weights[i];
			}

			// Try packing the endpoints
			bool failed_flag = false;

			for (uint32_t c = 0; c < 3; c++)
			{
				const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;

				const int min_delta = -(max_delta + 1);
				assert((max_delta - min_delta) == delta_bitmasks[c]);

				log_blk.m_endpoints[c][0] = blog_endpoints[c][0];

				int delta0 = (int)blog_endpoints[c][1] - (int)blog_endpoints[c][0];
				int delta1 = (int)blog_endpoints[c][2] - (int)blog_endpoints[c][0];
				int delta2 = (int)blog_endpoints[c][3] - (int)blog_endpoints[c][0];

				if ((delta0 < min_delta) || (delta0 > max_delta) ||
					(delta1 < min_delta) || (delta1 > max_delta) ||
					(delta2 < min_delta) || (delta2 > max_delta))
				{
					failed_flag = true;
					break;
				}

				log_blk.m_endpoints[c][1] = delta0 & delta_bitmasks[c];
				log_blk.m_endpoints[c][2] = delta1 & delta_bitmasks[c];
				log_blk.m_endpoints[c][3] = delta2 & delta_bitmasks[c];
			}

			if (failed_flag)
				continue;

			log_blk.m_mode = mode;
			log_blk.m_partition_pattern = pat_index;
			pack_bc6h_block(*pPacked_block, log_blk);

			//half_float blk[16 * 3];
			//unpack_bc6h(pPacked_block, blk, false);

			return;
		}

		bc6h_enc_block_2subset_mode9_3bit_weights(pPacked_block, common_part_index, pEndpoints, pWeights);
	}

	bool bc6h_enc_block_solid_color(bc6h_block* pPacked_block, const half_float pColor[3])
	{
		assert(g_bc6h_enc_initialized);

		if ((pColor[0] | pColor[1] | pColor[2]) & 0x8000)
			return false;

		// ASTC block unpacker won't allow Inf/NaN's to come through.
		//if (is_half_inf_or_nan(pColor[0]) || is_half_inf_or_nan(pColor[1]) || is_half_inf_or_nan(pColor[2]))
		//	return false;

		uint8_t weights[16];
		memset(weights, 0, sizeof(weights));

		half_float endpoints[3][2];
		endpoints[0][0] = pColor[0];
		endpoints[0][1] = pColor[0];
				
		endpoints[1][0] = pColor[1];
		endpoints[1][1] = pColor[1];

		endpoints[2][0] = pColor[2];
		endpoints[2][1] = pColor[2];
				
		bc6h_enc_block_1subset_4bit_weights(pPacked_block, endpoints, weights);

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------
	// basisu_astc_hdr_core.cpp

	static bool g_astc_hdr_core_initialized;
	static int8_t g_astc_partition_id_to_common_bc7_pat_index[1024];

	//--------------------------------------------------------------------------------------------------------------------------

	void astc_hdr_core_init()
	{
		if (g_astc_hdr_core_initialized)
			return;

		memset(g_astc_partition_id_to_common_bc7_pat_index, 0xFF, sizeof(g_astc_partition_id_to_common_bc7_pat_index));

		for (uint32_t part_index = 0; part_index < basist::TOTAL_ASTC_BC6H_COMMON_PARTITIONS2; ++part_index)
		{
			const uint32_t astc_pattern = basist::g_astc_bc7_common_partitions2[part_index].m_astc;
			//const uint32_t bc7_pattern = basist::g_astc_bc7_common_partitions2[part_index].m_bc7;

			assert(astc_pattern < 1024);
			g_astc_partition_id_to_common_bc7_pat_index[astc_pattern] = (int8_t)part_index;
		}

		g_astc_hdr_core_initialized = true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	static inline int astc_hdr_sign_extend(int src, int num_src_bits)
	{
		assert(basisu::is_in_range(num_src_bits, 2, 31));

		const bool negative = (src & (1 << (num_src_bits - 1))) != 0;
		if (negative)
			return src | ~((1 << num_src_bits) - 1);
		else
			return src & ((1 << num_src_bits) - 1);
	}

	static inline void astc_hdr_pack_bit(
		int& dst, int dst_bit,
		int src_val, int src_bit = 0)
	{
		assert(dst_bit >= 0 && dst_bit <= 31);
		int bit = basisu::get_bit(src_val, src_bit);
		dst |= (bit << dst_bit);
	}

	//--------------------------------------------------------------------------------------------------------------------------

	void decode_mode7_to_qlog12_ise20(
		const uint8_t* pEndpoints,
		int e[2][3],
		int* pScale)
	{
		assert(g_astc_hdr_core_initialized);

		for (uint32_t i = 0; i < NUM_MODE7_ENDPOINTS; i++)
		{
			assert(pEndpoints[i] <= 255);
		}

		const int v0 = pEndpoints[0], v1 = pEndpoints[1], v2 = pEndpoints[2], v3 = pEndpoints[3];

		// Extract mode bits and unpack to major component and mode.
		const int modeval = ((v0 & 0xC0) >> 6) | ((v1 & 0x80) >> 5) | ((v2 & 0x80) >> 4);

		int majcomp, mode;
		if ((modeval & 0xC) != 0xC)
		{
			majcomp = modeval >> 2;
			mode = modeval & 3;
		}
		else if (modeval != 0xF)
		{
			majcomp = modeval & 3;
			mode = 4;
		}
		else
		{
			majcomp = 0;
			mode = 5;
		}

		// Extract low-order bits of r, g, b, and s.
		int red = v0 & 0x3f;
		int green = v1 & 0x1f;
		int blue = v2 & 0x1f;
		int scale = v3 & 0x1f;

		// Extract high-order bits, which may be assigned depending on mode
		int x0 = (v1 >> 6) & 1;
		int x1 = (v1 >> 5) & 1;
		int x2 = (v2 >> 6) & 1;
		int x3 = (v2 >> 5) & 1;
		int x4 = (v3 >> 7) & 1;
		int x5 = (v3 >> 6) & 1;
		int x6 = (v3 >> 5) & 1;

		// Now move the high-order xs into the right place.
		const int ohm = 1 << mode;
		if (ohm & 0x30) green |= x0 << 6;
		if (ohm & 0x3A) green |= x1 << 5;
		if (ohm & 0x30) blue |= x2 << 6;
		if (ohm & 0x3A) blue |= x3 << 5;
		if (ohm & 0x3D) scale |= x6 << 5;
		if (ohm & 0x2D) scale |= x5 << 6;
		if (ohm & 0x04) scale |= x4 << 7;
		if (ohm & 0x3B) red |= x4 << 6;
		if (ohm & 0x04) red |= x3 << 6;
		if (ohm & 0x10) red |= x5 << 7;
		if (ohm & 0x0F) red |= x2 << 7;
		if (ohm & 0x05) red |= x1 << 8;
		if (ohm & 0x0A) red |= x0 << 8;
		if (ohm & 0x05) red |= x0 << 9;
		if (ohm & 0x02) red |= x6 << 9;
		if (ohm & 0x01) red |= x3 << 10;
		if (ohm & 0x02) red |= x5 << 10;

		// Shift the bits to the top of the 12-bit result.
		static const int s_shamts[6] = { 1,1,2,3,4,5 };

		const int shamt = s_shamts[mode];
		red <<= shamt;
		green <<= shamt;
		blue <<= shamt;
		scale <<= shamt;

		// Minor components are stored as differences
		if (mode != 5)
		{
			green = red - green;
			blue = red - blue;
		}

		// Swizzle major component into place
		if (majcomp == 1)
			std::swap(red, green);

		if (majcomp == 2)
			std::swap(red, blue);

		// Clamp output values, set alpha to 1.0
		e[1][0] = basisu::clamp(red, 0, 0xFFF);
		e[1][1] = basisu::clamp(green, 0, 0xFFF);
		e[1][2] = basisu::clamp(blue, 0, 0xFFF);

		e[0][0] = basisu::clamp(red - scale, 0, 0xFFF);
		e[0][1] = basisu::clamp(green - scale, 0, 0xFFF);
		e[0][2] = basisu::clamp(blue - scale, 0, 0xFFF);

		if (pScale)
			*pScale = scale;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool decode_mode7_to_qlog12(
		const uint8_t* pEndpoints,
		int e[2][3],
		int* pScale,
		uint32_t ise_endpoint_range)
	{
		assert(g_astc_hdr_core_initialized);

		if (ise_endpoint_range == astc_helpers::BISE_256_LEVELS)
		{
			decode_mode7_to_qlog12_ise20(pEndpoints, e, pScale);
		}
		else
		{
			uint8_t dequantized_endpoints[NUM_MODE7_ENDPOINTS];

			for (uint32_t i = 0; i < NUM_MODE7_ENDPOINTS; i++)
				dequantized_endpoints[i] = astc_helpers::g_dequant_tables.get_endpoint_tab(ise_endpoint_range).m_ISE_to_val[pEndpoints[i]];

			decode_mode7_to_qlog12_ise20(dequantized_endpoints, e, pScale);
		}

		for (uint32_t i = 0; i < 2; i++)
		{
			if (e[i][0] > (int)MAX_QLOG12)
				return false;

			if (e[i][1] > (int)MAX_QLOG12)
				return false;

			if (e[i][2] > (int)MAX_QLOG12)
				return false;
		}

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	void decode_mode11_to_qlog12_ise20(
		const uint8_t* pEndpoints,
		int e[2][3])
	{
#ifdef _DEBUG
		for (uint32_t i = 0; i < NUM_MODE11_ENDPOINTS; i++)
		{
			assert(pEndpoints[i] <= 255);
		}
#endif

		const uint32_t maj_comp = basisu::get_bit(pEndpoints[4], 7) | (basisu::get_bit(pEndpoints[5], 7) << 1);

		if (maj_comp == 3)
		{
			// Direct, qlog8 and qlog7
			e[0][0] = pEndpoints[0] << 4;
			e[1][0] = pEndpoints[1] << 4;

			e[0][1] = pEndpoints[2] << 4;
			e[1][1] = pEndpoints[3] << 4;

			e[0][2] = (pEndpoints[4] & 127) << 5;
			e[1][2] = (pEndpoints[5] & 127) << 5;
		}
		else
		{
			int v0 = pEndpoints[0];
			int v1 = pEndpoints[1];
			int v2 = pEndpoints[2];
			int v3 = pEndpoints[3];
			int v4 = pEndpoints[4];
			int v5 = pEndpoints[5];

			int mode = 0;
			astc_hdr_pack_bit(mode, 0, v1, 7);
			astc_hdr_pack_bit(mode, 1, v2, 7);
			astc_hdr_pack_bit(mode, 2, v3, 7);

			int va = v0;
			astc_hdr_pack_bit(va, 8, v1, 6);

			int vb0 = v2 & 63;
			int vb1 = v3 & 63;
			int vc = v1 & 63;

			int vd0 = v4 & 0x7F; // this takes more bits than is sometimes needed
			int vd1 = v5 & 0x7F; // this takes more bits than is sometimes needed
			static const int8_t dbitstab[8] = { 7,6,7,6,5,6,5,6 };
			vd0 = astc_hdr_sign_extend(vd0, dbitstab[mode]);
			vd1 = astc_hdr_sign_extend(vd1, dbitstab[mode]);

			int x0 = basisu::get_bit(v2, 6);
			int x1 = basisu::get_bit(v3, 6);
			int x2 = basisu::get_bit(v4, 6);
			int x3 = basisu::get_bit(v5, 6);
			int x4 = basisu::get_bit(v4, 5);
			int x5 = basisu::get_bit(v5, 5);

			const uint32_t ohm = 1U << mode;
			if (ohm & 0xA4) va |= (x0 << 9);
			if (ohm & 0x08) va |= (x2 << 9);
			if (ohm & 0x50) va |= (x4 << 9);
			if (ohm & 0x50) va |= (x5 << 10);
			if (ohm & 0xA0) va |= (x1 << 10);
			if (ohm & 0xC0) va |= (x2 << 11);
			if (ohm & 0x04) vc |= (x1 << 6);
			if (ohm & 0xE8) vc |= (x3 << 6);
			if (ohm & 0x20) vc |= (x2 << 7);
			if (ohm & 0x5B) vb0 |= (x0 << 6);
			if (ohm & 0x5B) vb1 |= (x1 << 6);
			if (ohm & 0x12) vb0 |= (x2 << 7);
			if (ohm & 0x12) vb1 |= (x3 << 7);

			const int shamt = (mode >> 1) ^ 3;
			
			va  = (uint32_t)va  << shamt;
			vb0 = (uint32_t)vb0 << shamt;
			vb1 = (uint32_t)vb1 << shamt;
			vc  = (uint32_t)vc  << shamt;
			vd0 = (uint32_t)vd0 << shamt;
			vd1 = (uint32_t)vd1 << shamt;

			// qlog12
			e[1][0] = basisu::clamp<int>(va, 0, 0xFFF);
			e[1][1] = basisu::clamp<int>(va - vb0, 0, 0xFFF);
			e[1][2] = basisu::clamp<int>(va - vb1, 0, 0xFFF);

			e[0][0] = basisu::clamp<int>(va - vc, 0, 0xFFF);
			e[0][1] = basisu::clamp<int>(va - vb0 - vc - vd0, 0, 0xFFF);
			e[0][2] = basisu::clamp<int>(va - vb1 - vc - vd1, 0, 0xFFF);

			if (maj_comp)
			{
				std::swap(e[0][0], e[0][maj_comp]);
				std::swap(e[1][0], e[1][maj_comp]);
			}
		}
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool decode_mode11_to_qlog12(
		const uint8_t* pEndpoints,
		int e[2][3],
		uint32_t ise_endpoint_range)
	{
		assert(g_astc_hdr_core_initialized);
		assert((ise_endpoint_range >= astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE) && (ise_endpoint_range <= astc_helpers::LAST_VALID_ENDPOINT_ISE_RANGE));

		if (ise_endpoint_range == astc_helpers::BISE_256_LEVELS)
		{
			decode_mode11_to_qlog12_ise20(pEndpoints, e);
		}
		else
		{
			uint8_t dequantized_endpoints[NUM_MODE11_ENDPOINTS];

			for (uint32_t i = 0; i < NUM_MODE11_ENDPOINTS; i++)
				dequantized_endpoints[i] = astc_helpers::g_dequant_tables.get_endpoint_tab(ise_endpoint_range).m_ISE_to_val[pEndpoints[i]];

			decode_mode11_to_qlog12_ise20(dequantized_endpoints, e);
		}

		for (uint32_t i = 0; i < 2; i++)
		{
			if (e[i][0] > (int)MAX_QLOG12)
				return false;

			if (e[i][1] > (int)MAX_QLOG12)
				return false;

			if (e[i][2] > (int)MAX_QLOG12)
				return false;
		}

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool transcode_bc6h_1subset(half_float h_e[3][2], const astc_helpers::log_astc_block& best_blk, bc6h_block& transcoded_bc6h_blk)
	{
		assert(g_astc_hdr_core_initialized);
		assert((best_blk.m_weight_ise_range >= 1) && (best_blk.m_weight_ise_range <= 8));
		
		if (best_blk.m_weight_ise_range == 5)
		{
			// Use 3-bit BC6H weights which are a perfect match for 3-bit ASTC weights, but encode 1-subset as 2 equal subsets
			bc6h_enc_block_1subset_3bit_weights(&transcoded_bc6h_blk, h_e, best_blk.m_weights);
		}
		else
		{
			uint8_t bc6h_weights[16];

			if (best_blk.m_weight_ise_range == 1)
			{
				// weight ISE 1: 3 levels
				static const uint8_t s_astc1_to_bc6h_3[3] = { 0, 8, 15 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc1_to_bc6h_3[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 2)
			{
				// weight ISE 2: 4 levels
				static const uint8_t s_astc2_to_bc6h_4[4] = { 0, 5, 10, 15 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc2_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 3)
			{
				// weight ISE 3: 5 levels
				static const uint8_t s_astc3_to_bc6h_4[5] = { 0, 4, 7, 11, 15 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc3_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 4)
			{
				// weight ISE 4: 6 levels
				static const uint8_t s_astc4_to_bc6h_4[6] = { 0, 15, 3, 12, 6, 9 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc4_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 6)
			{
				// weight ISE 6: 10 levels
				static const uint8_t s_astc6_to_bc6h_4[10] = { 0, 15, 2, 13, 3, 12, 5, 10, 6, 9 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc6_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 7)
			{
				// weight ISE 7: 12 levels
				static const uint8_t s_astc7_to_bc6h_4[12] = { 0, 15, 4, 11, 1, 14, 5, 10, 2, 13, 6, 9 };

				for (uint32_t i = 0; i < 16; i++)
					bc6h_weights[i] = s_astc7_to_bc6h_4[best_blk.m_weights[i]];
			}
			else if (best_blk.m_weight_ise_range == 8)
			{
				// 16 levels
				memcpy(bc6h_weights, best_blk.m_weights, 16);
			}
			else
			{
				assert(0);
				return false;
			}

			bc6h_enc_block_1subset_4bit_weights(&transcoded_bc6h_blk, h_e, bc6h_weights);
		}

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------

	bool transcode_bc6h_2subsets(uint32_t common_part_index, const astc_helpers::log_astc_block& best_blk, bc6h_block& transcoded_bc6h_blk)
	{
		assert(g_astc_hdr_core_initialized);
		assert(best_blk.m_num_partitions == 2);
		assert(common_part_index < basist::TOTAL_ASTC_BC6H_COMMON_PARTITIONS2);
		
		half_float bc6h_endpoints[2][3][2]; // [subset][comp][lh_index]

		// UASTC HDR checks
		// Both CEM's must be equal in 2-subset UASTC HDR.
		if (best_blk.m_color_endpoint_modes[0] != best_blk.m_color_endpoint_modes[1])
			return false;
		if ((best_blk.m_color_endpoint_modes[0] != 7) && (best_blk.m_color_endpoint_modes[0] != 11))
			return false;
				
		if (best_blk.m_color_endpoint_modes[0] == 7)
		{
			if (!(((best_blk.m_weight_ise_range == 1) && (best_blk.m_endpoint_ise_range == 20)) ||
		 		  ((best_blk.m_weight_ise_range == 2) && (best_blk.m_endpoint_ise_range == 20)) ||
				  ((best_blk.m_weight_ise_range == 3) && (best_blk.m_endpoint_ise_range == 19)) ||
				  ((best_blk.m_weight_ise_range == 4) && (best_blk.m_endpoint_ise_range == 17)) ||
				  ((best_blk.m_weight_ise_range == 5) && (best_blk.m_endpoint_ise_range == 15))))
			{
				return false;
			}
		}
		else
		{
			if (!(((best_blk.m_weight_ise_range == 1) && (best_blk.m_endpoint_ise_range == 14)) ||
				  ((best_blk.m_weight_ise_range == 2) && (best_blk.m_endpoint_ise_range == 12))))
			{
				return false;
			}
		}

		for (uint32_t s = 0; s < 2; s++)
		{
			int e[2][3];
			if (best_blk.m_color_endpoint_modes[0] == 7)
			{
				bool success = decode_mode7_to_qlog12(best_blk.m_endpoints + s * NUM_MODE7_ENDPOINTS, e, nullptr, best_blk.m_endpoint_ise_range);
				if (!success)
					return false;
			}
			else
			{
				bool success = decode_mode11_to_qlog12(best_blk.m_endpoints + s * NUM_MODE11_ENDPOINTS, e, best_blk.m_endpoint_ise_range);
				if (!success)
					return false;
			}

			for (uint32_t c = 0; c < 3; c++)
			{
				bc6h_endpoints[s][c][0] = qlog_to_half(e[0][c], 12);
				if (is_half_inf_or_nan(bc6h_endpoints[s][c][0]))
					return false;

				bc6h_endpoints[s][c][1] = qlog_to_half(e[1][c], 12);
				if (is_half_inf_or_nan(bc6h_endpoints[s][c][1]))
					return false;
			}
		}

		uint8_t bc6h_weights[16];
		if (best_blk.m_weight_ise_range == 1)
		{
			static const uint8_t s_astc1_to_bc6h_3[3] = { 0, 4, 7 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc1_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 2)
		{
			static const uint8_t s_astc2_to_bc6h_3[4] = { 0, 2, 5, 7 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc2_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 3)
		{
			static const uint8_t s_astc3_to_bc6h_3[5] = { 0, 2, 4, 5, 7 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc3_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 4)
		{
			static const uint8_t s_astc4_to_bc6h_3[6] = { 0, 7, 1, 6, 3, 4 };

			for (uint32_t i = 0; i < 16; i++)
				bc6h_weights[i] = s_astc4_to_bc6h_3[best_blk.m_weights[i]];
		}
		else if (best_blk.m_weight_ise_range == 5)
		{
			memcpy(bc6h_weights, best_blk.m_weights, 16);
		}
		else
		{
			assert(0);
			return false;
		}

		bc6h_enc_block_2subset_3bit_weights(&transcoded_bc6h_blk, common_part_index, bc6h_endpoints, bc6h_weights);

		return true;
	}

	//--------------------------------------------------------------------------------------------------------------------------
	// Transcodes an UASTC HDR block to BC6H. Must have been encoded to UASTC HDR, or this fails.
	bool astc_hdr_transcode_to_bc6h(const astc_blk& src_blk, bc6h_block& dst_blk)
	{
		assert(g_astc_hdr_core_initialized);
		if (!g_astc_hdr_core_initialized)
		{
			assert(0);
			return false;
		}

		astc_helpers::log_astc_block log_blk;

		if (!astc_helpers::unpack_block(&src_blk, log_blk, 4, 4))
		{
			// Failed unpacking ASTC data
			return false;
		}

		return astc_hdr_transcode_to_bc6h(log_blk, dst_blk);
	}

	//--------------------------------------------------------------------------------------------------------------------------
	// Transcodes an UASTC HDR block to BC6H. Must have been encoded to UASTC HDR, or this fails.
	bool astc_hdr_transcode_to_bc6h(const astc_helpers::log_astc_block& log_blk, bc6h_block& dst_blk)
	{
		assert(g_astc_hdr_core_initialized);
		if (!g_astc_hdr_core_initialized)
		{
			assert(0);
			return false;
		}
				
		if (log_blk.m_solid_color_flag_ldr)
		{
			// Don't support LDR solid colors.
			return false;
		}

		if (log_blk.m_solid_color_flag_hdr)
		{
			// Solid color HDR block
			return bc6h_enc_block_solid_color(&dst_blk, log_blk.m_solid_color);
		}

		// Only support 4x4 grid sizes
		if ((log_blk.m_grid_width != 4) || (log_blk.m_grid_height != 4))
			return false;
				
		// Don't support dual plane encoding
		if (log_blk.m_dual_plane)
			return false;

		if (log_blk.m_num_partitions == 1)
		{
			// Handle 1 partition (or subset)
			
			// UASTC HDR checks
			if ((log_blk.m_weight_ise_range < 1) || (log_blk.m_weight_ise_range > 8))
				return false;
									
			int e[2][3];
			bool success;

			if (log_blk.m_color_endpoint_modes[0] == 7)
			{
				if (log_blk.m_endpoint_ise_range != 20)
					return false;

				success = decode_mode7_to_qlog12(log_blk.m_endpoints, e, nullptr, log_blk.m_endpoint_ise_range);
			}
			else if (log_blk.m_color_endpoint_modes[0] == 11)
			{
				// UASTC HDR checks
				if (log_blk.m_weight_ise_range <= 7)
				{
					if (log_blk.m_endpoint_ise_range != 20)
						return false;
				}
				else if (log_blk.m_endpoint_ise_range != 19)
				{
					return false;
				}

				success = decode_mode11_to_qlog12(log_blk.m_endpoints, e, log_blk.m_endpoint_ise_range);
			}
			else
			{
				return false;
			}

			if (!success)
				return false;

			// Transform endpoints to half float
			half_float h_e[3][2] =
			{
				{ qlog_to_half(e[0][0], 12), qlog_to_half(e[1][0], 12) },
				{ qlog_to_half(e[0][1], 12), qlog_to_half(e[1][1], 12) },
				{ qlog_to_half(e[0][2], 12), qlog_to_half(e[1][2], 12) }
			};

			// Sanity check for NaN/Inf
			for (uint32_t i = 0; i < 2; i++)
				if (is_half_inf_or_nan(h_e[0][i]) || is_half_inf_or_nan(h_e[1][i]) || is_half_inf_or_nan(h_e[2][i]))
					return false;
			
			// Transcode to bc6h
			if (!transcode_bc6h_1subset(h_e, log_blk, dst_blk))
				return false;
		}
		else if (log_blk.m_num_partitions == 2)
		{
			// Handle 2 partition (or subset)
			int common_bc7_pat_index = g_astc_partition_id_to_common_bc7_pat_index[log_blk.m_partition_id];
			if (common_bc7_pat_index < 0)
				return false;

			assert(common_bc7_pat_index < (int)basist::TOTAL_ASTC_BC6H_COMMON_PARTITIONS2);
						
			if (!transcode_bc6h_2subsets(common_bc7_pat_index, log_blk, dst_blk))
				return false;
		}
		else
		{
			// Only supports 1 or 2 partitions (or subsets)
			return false;
		}

		return true;
	}
			
	// ASTC 6x6 support
	namespace astc_6x6_hdr
	{
		const block_mode_desc g_block_mode_descs[TOTAL_BLOCK_MODE_DECS] =
		{
			// ------ mode 11
			{ false, 11, 1, 6, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 6, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 6, 5, astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS,  astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 5, 6, astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS,  astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 6, 4, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 4, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 6, 3, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 3, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 5, 5, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_8_LEVELS,  astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 1, 4, 4, astc_helpers::BISE_192_LEVELS, astc_helpers::BISE_16_LEVELS,  astc_helpers::BISE_192_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 11, 1, 3, 3, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_16_LEVELS, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// ------ mode 7
			{ false, 7, 1, 6, 6, astc_helpers::BISE_96_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_96_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 7, 1, 6, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 1, 6, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_4_LEVELS,  astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 7, 1, 5, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_6_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 1, 6, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_6_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			{ false, 7, 1, 3, 6, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_20_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_20_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 1, 6, 3, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_20_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_20_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// ------ mode 11, 2 subset
			{ false, 11, 2, 6, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_2_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x3/3x6
			{ false, 11, 2, 6, 3, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 2, 3, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// 3x6/6x3
			{ false, 11, 2, 3, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 11, 2, 6, 3, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// 3x6/6x3
			{ false, 11, 2, 4, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 11, 2, 6, 4, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,  astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS, 0, 0 },

			// ------ mode 7, 2 subset

			// 6x5/5x6
			{ false, 7, 2, 5, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 2, 6, 5, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x4/4x6 mode 7
			{ false, 7, 2, 4, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 2, 6, 4, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x6
			{ false, 7, 2, 6, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x6
			{ false, 7, 2, 6, 6, astc_helpers::BISE_192_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_192_LEVELS,  astc_helpers::BISE_2_LEVELS, 0, 0 },

			// 5x5
			{ false, 7, 2, 5, 5, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, 0, 0 },

			// 6x3/3x6 mode 7
			{ false, 7, 2, 3, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_8_LEVELS, 0, 0 },
			{ false, 7, 2, 6, 3, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_8_LEVELS, 0, 0 },

			// 6x3/3x6 mode 7
			{ false, 7, 2, 3, 6, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_6_LEVELS, 0, 0 },
			{ false, 7, 2, 6, 3, astc_helpers::BISE_80_LEVELS, astc_helpers::BISE_6_LEVELS,   astc_helpers::BISE_80_LEVELS,  astc_helpers::BISE_6_LEVELS, 0, 0 },

			// ------ dual plane

			// 3x6
			{ true, 11, 1, 3, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 3, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 3, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },

			// 6x3
			{ true, 11, 1, 6, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 6, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 6, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },

			// 3x3
			{ true, 11, 1, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_16_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_16_LEVELS, BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },

			// 4x4
			{ true, 11, 1, 4, 4, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 4, 4, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 4, 4, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_5_LEVELS, BASIST_HDR_6X6_LEVEL2, 2 },

			// 5x5
			{ true, 11, 1, 5, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 5, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 5, 5, astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 2 },

			// ------ 2x2 modes for RDO
			// note 2x2 modes will be upsampled to 4x4 during transcoding (the min # of weight bits is 7 in ASTC)
			{ true, 11, 1, 2, 2, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },
			{ true, 11, 1, 2, 2, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 1 },
			{ true, 11, 1, 2, 2, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_256_LEVELS,  astc_helpers::BISE_8_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 2 },
			{ false, 11, 1, 2, 2, astc_helpers::BISE_128_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_256_LEVELS, astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL0 | BASIST_HDR_6X6_LEVEL1 | BASIST_HDR_6X6_LEVEL2, 0 },

			// ------ 3 subsets

			// 6x6
			{ false, 7, 3, 6, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 5x5
			{ false, 7, 3, 5, 5, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 4x4
			{ false, 7, 3, 4, 4, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_3_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 4, 4, astc_helpers::BISE_40_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_40_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 4, 4, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_5_LEVELS, 0, 0 },

			// 3x3
			{ false, 7, 3, 3, 3, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_8_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_8_LEVELS, 0, 0 },

			// 6x4 
			{ false, 7, 3, 6, 4, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 4, 6, astc_helpers::BISE_64_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_64_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x4
			{ false, 7, 3, 6, 4, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 7, 3, 4, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },

			// 6x5
			{ false, 7, 3, 6, 5, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 5, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_2_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_2_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x3
			{ false, 7, 3, 6, 3, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 7, 3, 3, 6, astc_helpers::BISE_48_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_48_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },

			// 6x3
			{ false, 7, 3, 6, 3, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },
			{ false, 7, 3, 3, 6, astc_helpers::BISE_32_LEVELS, astc_helpers::BISE_4_LEVELS,   astc_helpers::BISE_32_LEVELS,  astc_helpers::BISE_4_LEVELS, BASIST_HDR_6X6_LEVEL2, 0 },

			// 6x3
			{ false, 7, 3, 6, 3, astc_helpers::BISE_24_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_24_LEVELS,  astc_helpers::BISE_5_LEVELS, 0, 0 },
			{ false, 7, 3, 3, 6, astc_helpers::BISE_24_LEVELS, astc_helpers::BISE_5_LEVELS,   astc_helpers::BISE_24_LEVELS,  astc_helpers::BISE_5_LEVELS, 0, 0 },

			// 5x4
			{ false, 7, 3, 5, 4, astc_helpers::BISE_40_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_40_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
			{ false, 7, 3, 4, 5, astc_helpers::BISE_40_LEVELS, astc_helpers::BISE_3_LEVELS,   astc_helpers::BISE_40_LEVELS,  astc_helpers::BISE_3_LEVELS, 0, 0 },
		};
						
		const reuse_xy_delta g_reuse_xy_deltas[NUM_REUSE_XY_DELTAS] =
		{
			{ -1, 0 }, { -2, 0 }, { -3, 0 }, { -4, 0 },
			{ 3, -1 }, { 2, -1 }, { 1, -1 }, { 0, -1 }, { -1, -1 }, { -2, -1 }, { -3, -1 }, { -4, -1 },
			{ 3, -2 }, { 2, -2 }, { 1, -2 }, { 0, -2 }, { -1, -2 }, { -2, -2 }, { -3, -2 }, { -4, -2 },
			{ 3, -3 }, { 2, -3 }, { 1, -3 }, { 0, -3 }, { -1, -3 }, { -2, -3 }, { -3, -3 }, { -4, -3 },
			{ 3, -4 }, { 2, -4 }, { 1, -4 }, { 0, -4 }
		};

		//--------------------------------------------------------------------------------------------------------------------------

		void requantize_astc_weights(uint32_t n, const uint8_t* pSrc_ise_vals, uint32_t from_ise_range, uint8_t* pDst_ise_vals, uint32_t to_ise_range)
		{
			if (from_ise_range == to_ise_range)
			{
				if (pDst_ise_vals != pSrc_ise_vals)
					memcpy(pDst_ise_vals, pSrc_ise_vals, n);
				return;
			}

			const auto& dequant_tab = astc_helpers::g_dequant_tables.get_weight_tab(from_ise_range).m_ISE_to_val;
			const auto& quant_tab = astc_helpers::g_dequant_tables.get_weight_tab(to_ise_range).m_val_to_ise;

			for (uint32_t i = 0; i < n; i++)
				pDst_ise_vals[i] = quant_tab[dequant_tab[pSrc_ise_vals[i]]];
		}

		//--------------------------------------------------------------------------------------------------------------------------

		inline int get_bit(
			int src_val, int src_bit)
		{
			assert(src_bit >= 0 && src_bit <= 31);
			int bit = (src_val >> src_bit) & 1;
			return bit;
		}

		inline void pack_bit(
			int& dst, int dst_bit,
			int src_val, int src_bit = 0)
		{
			assert(dst_bit >= 0 && dst_bit <= 31);
			int bit = get_bit(src_val, src_bit);
			dst |= (bit << dst_bit);
		}
				
		// Valid for weight ISE ranges 6-192 or 8-192 levels. Preserves upper 2 or 3 bits post-quantization.
		uint8_t g_quantize_tables_preserve2[21 - 1][256]; // astc_helpers::TOTAL_ISE_RANGES=21, valid for >= BISE_6_LEVELS
		uint8_t g_quantize_tables_preserve3[21 - 1][256]; // valid for >= BISE_8_LEVELS

		const uint32_t g_part2_unique_index_to_seed[NUM_UNIQUE_PARTITIONS2] =
		{
			86, 959, 936, 476, 1007, 672, 447, 423, 488, 422, 273, 65, 267, 786, 585, 195, 108, 731, 878, 812, 264, 125, 868, 581, 258, 390, 549, 872, 661, 352, 645, 543, 988, 
			906, 903, 616, 482, 529, 3, 286, 272, 303, 151, 504, 498, 260, 79, 66, 608, 769, 305, 610, 1014, 967, 835, 789, 7, 951, 691, 15, 763, 976, 438, 314, 601, 673, 177, 
			252, 615, 436, 220, 899, 623, 433, 674, 278, 797, 107, 847, 114, 470, 760, 821, 490, 329, 945, 387, 471, 225, 172, 83, 418, 966, 439, 316, 247, 43, 343, 625, 798, 
			1, 61, 73, 307, 136, 474, 42, 664, 1013, 249, 389, 227, 374, 121, 48, 538, 226, 309, 554, 802, 834, 335, 495, 10, 955, 461, 293, 508, 153, 101, 63, 139, 31, 687, 
			132, 174, 324, 545, 289, 39, 178, 594, 963, 854, 222, 323, 998, 964, 598, 475, 720, 1019, 983, 91, 703, 614, 394, 612, 281, 207, 930, 758, 586, 128, 517, 426, 306, 
			168, 713, 36, 458, 876, 368, 780, 5, 9, 214, 109, 553, 726, 175, 103, 753, 684, 44, 665, 53, 500, 367, 611, 119, 732, 639, 326, 203, 156, 686, 910, 255, 62, 392, 591, 
			112, 88, 213, 19, 1022, 478, 90, 486, 799, 702, 730, 414, 99, 1008, 142, 886, 373, 216, 69, 393, 299, 648, 415, 822, 912, 110, 567, 550, 693, 2, 138, 59, 271, 562, 295, 
			714, 719, 199, 893, 831, 1006, 662, 235, 262, 78, 51, 902, 298, 190, 169, 583, 347, 890, 958, 909, 49, 987, 696, 633, 480, 50, 764, 826, 1023, 1016, 437, 891, 774, 257, 
			724, 791, 526, 593, 690, 638, 858, 895, 794, 995, 130, 87, 877, 819, 318, 649, 376, 211, 284, 937, 370, 688, 229, 994, 115, 842, 60, 521, 95, 694, 804, 146, 754, 487, 55, 
			17, 770, 450, 223, 4, 137, 911, 236, 683, 523, 47, 181, 24, 270, 602, 736, 11, 355, 148, 351, 762, 1009, 16, 210, 619, 805, 874, 807, 887, 403, 999, 810, 27, 402, 551, 135, 
			778, 33, 409, 993, 71, 363, 159, 183, 77, 596, 670, 380, 968, 811, 404, 348, 539, 158, 578, 196, 621, 68, 530, 193, 100, 167, 919, 353, 366, 327, 643, 948, 518, 756, 801, 558, 
			28, 705, 116, 94, 898, 453, 622, 647, 231, 445, 652, 230, 191, 277, 292, 254, 198, 766, 386, 232, 29, 70, 942, 740, 291, 607, 411, 496, 839, 8, 675, 319, 742, 21, 547, 627, 716, 
			663, 23, 914, 631, 595, 499, 685, 950, 510, 54, 587, 432, 45, 646, 25, 122, 947, 171, 862, 441, 808, 722, 14, 74, 658, 129, 266, 1001, 534, 395, 527, 250, 206, 237, 67, 897, 634, 
			572, 569, 533, 37, 341, 89, 463, 419, 75, 134, 283, 943, 519, 362, 144, 681, 407, 954, 131, 455, 934, 46, 513, 339, 194, 361, 606, 852, 546, 655, 1015, 147, 506, 240, 56, 836, 76, 
			98, 600, 430, 388, 980, 695, 817, 279, 58, 215, 149, 170, 531, 870, 18, 727, 154, 26, 938, 929, 302, 697, 452, 218, 700, 524, 828, 751, 869, 217, 440, 354
		};

		const uint32_t g_part3_unique_index_to_seed[NUM_UNIQUE_PARTITIONS3] =
		{
			0, 8, 11, 14, 15, 17, 18, 19, 26, 31, 34, 35, 36, 38, 44, 47, 48, 49, 51, 56,
			59, 61, 70, 74, 76, 82, 88, 90, 96, 100, 103, 104, 108, 110, 111, 117, 122, 123,
			126, 127, 132, 133, 135, 139, 147, 150, 151, 152, 156, 157, 163, 166, 168, 171,
			175, 176, 179, 181, 182, 183, 186, 189, 192, 199, 203, 205, 207, 210, 214, 216,
			222, 247, 249, 250, 252, 254, 260, 261, 262, 263, 266, 272, 273, 275, 276, 288,
			291, 292, 293, 294, 297, 302, 309, 310, 313, 314, 318, 327, 328, 331, 335, 337,
			346, 356, 357, 358, 363, 365, 368, 378, 381, 384, 386, 390, 391, 392, 396, 397,
			398, 399, 401, 410, 411, 419, 427, 430, 431, 437, 439, 440, 451, 455, 457, 458,
			459, 460, 462, 468, 470, 471, 472, 474, 475, 477, 479, 482, 483, 488, 493, 495,
			496, 502, 503, 504, 507, 510, 511, 512, 515, 516, 518, 519, 522, 523, 525, 526,
			527, 538, 543, 544, 546, 547, 549, 550, 552, 553, 554, 562, 570, 578, 579, 581,
			582, 588, 589, 590, 593, 595, 600, 606, 611, 613, 618, 623, 625, 632, 637, 638,
			645, 646, 650, 651, 658, 659, 662, 666, 667, 669, 670, 678, 679, 685, 686, 687,
			688, 691, 694, 696, 698, 699, 700, 701, 703, 704, 707, 713, 714, 715, 717, 719,
			722, 724, 727, 730, 731, 734, 738, 739, 743, 747, 748, 750, 751, 753, 758, 760,
			764, 766, 769, 775, 776, 783, 784, 785, 787, 791, 793, 798, 799, 802, 804, 805,
			806, 807, 808, 809, 810, 813, 822, 823, 825, 831, 835, 837, 838, 839, 840, 842,
			845, 846, 848, 853, 854, 858, 859, 860, 866, 874, 882, 884, 887, 888, 892, 894,
			898, 902, 907, 914, 915, 918, 919, 922, 923, 925, 927, 931, 932, 937, 938, 940,
			943, 944, 945, 953, 955, 958, 959, 963, 966, 971, 974, 979, 990, 991, 998, 999,
			1007, 1010, 1011, 1012, 1015, 1020, 1023
		};

		static void init_quantize_tables()
		{
			// 9/15/2025 changed lower range for LDR
			// for (uint32_t ise_range = astc_helpers::BISE_192_LEVELS; ise_range >= astc_helpers::BISE_12_LEVELS; ise_range--)
			for (uint32_t ise_range = astc_helpers::BISE_192_LEVELS; ise_range >= astc_helpers::BISE_6_LEVELS; ise_range--)
			{
				const uint32_t num_levels = astc_helpers::get_ise_levels(ise_range);
				const auto& ise_to_val_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_ISE_to_val;

				for (uint32_t desired_val = 0; desired_val < 256; desired_val++)
				{
					{
						uint32_t best_err = UINT32_MAX;
						int best_ise_val = -1;

						for (uint32_t ise_val = 0; ise_val < num_levels; ise_val++)
						{
							const uint32_t quant_val = ise_to_val_tab[ise_val];

							if ((quant_val & 0b11000000) != (desired_val & 0b11000000))
								continue;

							uint32_t err = basisu::squarei((int)quant_val - (int)desired_val);
							if (err < best_err)
							{
								best_err = err;
								best_ise_val = ise_val;
							}

						} // ise_val

						assert(best_ise_val != -1);

						g_quantize_tables_preserve2[ise_range][desired_val] = (uint8_t)best_ise_val;
					}

					if (ise_range >= astc_helpers::BISE_8_LEVELS)
					{
						uint32_t best_err = UINT32_MAX;
						int best_ise_val = -1;

						for (uint32_t ise_val = 0; ise_val < num_levels; ise_val++)
						{
							const uint32_t quant_val = ise_to_val_tab[ise_val];

							if ((quant_val & 0b11100000) != (desired_val & 0b11100000))
								continue;

							uint32_t err = basisu::squarei((int)quant_val - (int)desired_val);
							if (err < best_err)
							{
								best_err = err;
								best_ise_val = ise_val;
							}

						} // ise_val

						assert(best_ise_val != -1);

						g_quantize_tables_preserve3[ise_range][desired_val] = (uint8_t)best_ise_val;
					}

				} // desired_val

#if 0
				for (uint32_t i = 0; i < 256; i++)
				{
					if (g_quantize_tables_preserve2[ise_range][i] != astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i])
					{
						fmt_printf("P2, Range: {}, {} vs. {}\n", ise_range, g_quantize_tables_preserve2[ise_range][i], astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i]);
					}

					if (g_quantize_tables_preserve3[ise_range][i] != astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i])
					{
						fmt_printf("P3, Range: {}, {} vs. {}\n", ise_range, g_quantize_tables_preserve3[ise_range][i], astc_helpers::g_dequant_tables.get_endpoint_tab(ise_range).m_val_to_ise[i]);
					}
				}
#endif

			} // ise_range
		}

		void requantize_ise_endpoints(uint32_t cem, uint32_t src_ise_endpoint_range, const uint8_t* pSrc_endpoints, uint32_t dst_ise_endpoint_range, uint8_t* pDst_endpoints)
		{
			assert(pSrc_endpoints != pDst_endpoints);
			assert((src_ise_endpoint_range >= astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE) && (src_ise_endpoint_range <= astc_helpers::LAST_VALID_ENDPOINT_ISE_RANGE));
			assert((dst_ise_endpoint_range >= astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE) && (dst_ise_endpoint_range <= astc_helpers::LAST_VALID_ENDPOINT_ISE_RANGE));

			// must be >=12 ISE levels for g_quantize_tables_preserve2 etc.
			assert(dst_ise_endpoint_range >= astc_helpers::BISE_12_LEVELS);

			const uint32_t n = (cem == 11) ? basist::NUM_MODE11_ENDPOINTS : basist::NUM_MODE7_ENDPOINTS;

			if (src_ise_endpoint_range == dst_ise_endpoint_range)
			{
				memcpy(pDst_endpoints, pSrc_endpoints, n);
				return;
			}

			uint8_t temp_endpoints[basist::NUM_MODE11_ENDPOINTS];
			if (src_ise_endpoint_range != astc_helpers::BISE_256_LEVELS)
			{
				assert(n <= basist::NUM_MODE11_ENDPOINTS);

				const auto& endpoint_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(src_ise_endpoint_range).m_ISE_to_val;

				for (uint32_t i = 0; i < n; i++)
					temp_endpoints[i] = endpoint_dequant_tab[pSrc_endpoints[i]];

				pSrc_endpoints = temp_endpoints;
			}

			if (dst_ise_endpoint_range == astc_helpers::BISE_256_LEVELS)
			{
				memcpy(pDst_endpoints, pSrc_endpoints, n);
				return;
			}

			const auto& quant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_val_to_ise;

			const auto& dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_ISE_to_val;
			BASISU_NOTE_UNUSED(dequant_tab);

#if 1
			// A smarter value quantization that preserves the key upper bits. (If these bits get corrupted, the entire meaning of the encoding can get lost.)
			if (cem == 11)
			{
				assert(n == 6);

				int maj_comp = 0;
				pack_bit(maj_comp, 0, pSrc_endpoints[4], 7);
				pack_bit(maj_comp, 1, pSrc_endpoints[5], 7);

				if (maj_comp == 3)
				{
					// Direct
					pDst_endpoints[0] = quant_tab[pSrc_endpoints[0]];
					pDst_endpoints[1] = quant_tab[pSrc_endpoints[1]];
					pDst_endpoints[2] = quant_tab[pSrc_endpoints[2]];
					pDst_endpoints[3] = quant_tab[pSrc_endpoints[3]];
					// No need for preserve1 tables, we can use the regular quantization tables because they preserve the MSB.
					pDst_endpoints[4] = quant_tab[pSrc_endpoints[4]];
					pDst_endpoints[5] = quant_tab[pSrc_endpoints[5]];

					assert((dequant_tab[pDst_endpoints[4]] & 128) == (pSrc_endpoints[4] & 128));
					assert((dequant_tab[pDst_endpoints[5]] & 128) == (pSrc_endpoints[5] & 128));
				}
				else
				{
					pDst_endpoints[0] = quant_tab[pSrc_endpoints[0]];
					pDst_endpoints[1] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[1]];
					pDst_endpoints[2] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[2]];
					pDst_endpoints[3] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[3]];
					pDst_endpoints[4] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[4]];
					pDst_endpoints[5] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[5]];

					assert((dequant_tab[pDst_endpoints[1]] & 0b11000000) == (pSrc_endpoints[1] & 0b11000000));
					assert((dequant_tab[pDst_endpoints[2]] & 0b11000000) == (pSrc_endpoints[2] & 0b11000000));
					assert((dequant_tab[pDst_endpoints[3]] & 0b11000000) == (pSrc_endpoints[3] & 0b11000000));
					assert((dequant_tab[pDst_endpoints[4]] & 0b11100000) == (pSrc_endpoints[4] & 0b11100000));
					assert((dequant_tab[pDst_endpoints[5]] & 0b11100000) == (pSrc_endpoints[5] & 0b11100000));
				}
			}
			else if (cem == 7)
			{
				assert(n == 4);

				pDst_endpoints[0] = g_quantize_tables_preserve2[dst_ise_endpoint_range][pSrc_endpoints[0]];
				pDst_endpoints[1] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[1]];
				pDst_endpoints[2] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[2]];
				pDst_endpoints[3] = g_quantize_tables_preserve3[dst_ise_endpoint_range][pSrc_endpoints[3]];

				assert((dequant_tab[pDst_endpoints[0]] & 0b11000000) == (pSrc_endpoints[0] & 0b11000000));
				assert((dequant_tab[pDst_endpoints[1]] & 0b11100000) == (pSrc_endpoints[1] & 0b11100000));
				assert((dequant_tab[pDst_endpoints[2]] & 0b11100000) == (pSrc_endpoints[2] & 0b11100000));
				assert((dequant_tab[pDst_endpoints[3]] & 0b11100000) == (pSrc_endpoints[3] & 0b11100000));
			}
			else
			{
				assert(0);
			}
#else
			for (uint32_t i = 0; i < n; i++)
			{
				uint32_t v = pSrc_endpoints[i];
				assert(v <= 255);

				pDst_endpoints[i] = quant_tab[v];
			}
#endif
		}

		void copy_weight_grid(bool dual_plane, uint32_t grid_x, uint32_t grid_y, const uint8_t* transcode_weights, astc_helpers::log_astc_block& decomp_blk, bool orig_behavior)
		{
			assert(decomp_blk.m_weight_ise_range >= astc_helpers::BISE_2_LEVELS);
			assert(decomp_blk.m_weight_ise_range <= astc_helpers::BISE_32_LEVELS);

			// Special case for 2x2 which isn't typically valid ASTC (too few weight bits without dual plane). Upsample to 4x4.
			if ((!dual_plane) && (grid_x == 2) && (grid_y == 2))
			{
				decomp_blk.m_grid_width = 4;
				decomp_blk.m_grid_height = 4;

				//const uint32_t total_weight_levels = astc_helpers::bise_levels(decomp_blk.m_weight_ise_range);
				const auto& dequant_weight = astc_helpers::g_dequant_tables.get_weight_tab(decomp_blk.m_weight_ise_range).m_ISE_to_val;
				const auto& quant_weight = astc_helpers::g_dequant_tables.get_weight_tab(decomp_blk.m_weight_ise_range).m_val_to_ise;

				astc_helpers::weighted_sample weights[16];

				compute_upsample_weights(4, 4, 2, 2, weights);

				for (uint32_t dy = 0; dy < 4; dy++)
				{
					for (uint32_t dx = 0; dx < 4; dx++)
					{
						const astc_helpers::weighted_sample& sample = weights[dx + dy * 4];
						const int sx = sample.m_src_x, sy = sample.m_src_y;

						uint32_t total_weight = 8;

						for (uint32_t yo = 0; yo < 2; yo++)
						{
							for (uint32_t xo = 0; xo < 2; xo++)
							{
								if (!sample.m_weights[yo][xo])
									continue;

								// 10/17/2025 - bugfix. Orig release would always sample the 1st or 2nd weight here. Minor issue - encoder would have detected it, hurting R-D performance a tiny bit but not encoding/decoding correctness.
								// However, this fix does cause decoding divergence from original encodes. The divergence seems minor and can only happen at higher lambdas.
								if (orig_behavior)
								{
									// Original, incorrect, but ultimately harmless behavior.
									total_weight += dequant_weight[transcode_weights[basisu::is_in_bounds((dx + xo) + (dy + yo) * grid_x, 0, grid_x * grid_y)]] * sample.m_weights[yo][xo];
								}
								else
								{
									// Correct behavior.
									assert(basisu::is_in_bounds((sx + xo) + (sy + yo) * grid_x, 0, grid_x * grid_y));
									total_weight += dequant_weight[transcode_weights[(sx + xo) + (sy + yo) * grid_x]] * sample.m_weights[yo][xo];
								}
							} // x
						} // y

						total_weight >>= 4;

						assert(total_weight <= 64);

						decomp_blk.m_weights[dx + dy * 4] = quant_weight[total_weight];
					}
				}
			}
			else
			{
				const uint32_t num_planes = dual_plane ? 2 : 1;

				decomp_blk.m_grid_width = (uint8_t)grid_x;
				decomp_blk.m_grid_height = (uint8_t)grid_y;
				memcpy(decomp_blk.m_weights, transcode_weights, grid_x * grid_y * num_planes);
			}
		}

		// cur_y is the current destination row
		// prev_y is the row we want to access
		static inline int calc_row_index(int cur_y, int prev_y, int cur_row_index)
		{
			assert((cur_y >= 0) && (prev_y >= 0));
			assert((cur_row_index >= 0) && (cur_row_index < REUSE_MAX_BUFFER_ROWS));

			int delta_y = prev_y - cur_y;
			assert((delta_y > -REUSE_MAX_BUFFER_ROWS) && (delta_y <= 0));

			cur_row_index += delta_y;
			if (cur_row_index < 0)
				cur_row_index += REUSE_MAX_BUFFER_ROWS;

			assert((cur_row_index >= 0) && (cur_row_index < REUSE_MAX_BUFFER_ROWS));

			return cur_row_index;
		}

		bool decode_values(basist::bitwise_decoder& decoder, uint32_t total_values, uint32_t ise_range, uint8_t* pValues)
		{
			assert(ise_range <= astc_helpers::BISE_256_LEVELS);

			const uint32_t ep_bits = astc_helpers::g_ise_range_table[ise_range][0];
			const uint32_t ep_trits = astc_helpers::g_ise_range_table[ise_range][1];
			const uint32_t ep_quints = astc_helpers::g_ise_range_table[ise_range][2];

			uint32_t total_tqs = 0;
			uint32_t bundle_size = 0, mul = 0;
			if (ep_trits)
			{
				total_tqs = (total_values + 4) / 5;
				bundle_size = 5;
				mul = 3;
			}
			else if (ep_quints)
			{
				total_tqs = (total_values + 2) / 3;
				bundle_size = 3;
				mul = 5;
			}

			const uint32_t MAX_TQ_VALUES = 32;
			assert(total_tqs <= MAX_TQ_VALUES);
			uint32_t tq_values[MAX_TQ_VALUES];

			for (uint32_t i = 0; i < total_tqs; i++)
			{
				uint32_t num_bits = ep_trits ? 8 : 7;

				if (i == (total_tqs - 1))
				{
					uint32_t num_remaining = total_values - (total_tqs - 1) * bundle_size;
					if (ep_trits)
					{
						switch (num_remaining)
						{
						case 1: num_bits = 2; break;
						case 2: num_bits = 4; break;
						case 3: num_bits = 5; break;
						case 4: num_bits = 7; break;
						default: break;
						}
					}
					else if (ep_quints)
					{
						switch (num_remaining)
						{
						case 1: num_bits = 3; break;
						case 2: num_bits = 5; break;
						default: break;
						}
					}
				}

				tq_values[i] = (uint32_t)decoder.get_bits(num_bits);
			} // i

			uint32_t accum = 0;
			uint32_t accum_remaining = 0;
			uint32_t next_tq_index = 0;

			for (uint32_t i = 0; i < total_values; i++)
			{
				uint32_t value = (uint32_t)decoder.get_bits(ep_bits);

				if (total_tqs)
				{
					if (!accum_remaining)
					{
						assert(next_tq_index < total_tqs);
						accum = tq_values[next_tq_index++];
						accum_remaining = bundle_size;
					}

					uint32_t v = accum % mul;
					accum /= mul;
					accum_remaining--;

					value |= (v << ep_bits);
				}

				pValues[i] = (uint8_t)value;
			}

			return true;
		}

		static inline uint32_t get_num_endpoint_vals(uint32_t cem)
		{
			assert((cem == 7) || (cem == 11));
			return (cem == 11) ? basist::NUM_MODE11_ENDPOINTS : basist::NUM_MODE7_ENDPOINTS;
		}
				
		const uint32_t g_bc6h_weights4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };

#if 0
		static BASISU_FORCE_INLINE int pos_lrintf(float x)
		{
			assert(x >= 0.0f);
			return (int)(x + .5f);
		}

		static BASISU_FORCE_INLINE basist::half_float fast_float_to_half_non_neg_no_nan_inf(float val)
		{
			union { float f; int32_t i; uint32_t u; } fi = { val };
			const int flt_m = fi.i & 0x7FFFFF, flt_e = (fi.i >> 23) & 0xFF;
			int e = 0, m = 0;

			assert(((fi.i >> 31) == 0) && (flt_e != 0xFF));

			// not zero or denormal
			if (flt_e != 0)
			{
				int new_exp = flt_e - 127;
				if (new_exp > 15)
					e = 31;
				else if (new_exp < -14)
					m = pos_lrintf((1 << 24) * fabsf(fi.f));
				else
				{
					e = new_exp + 15;
					m = pos_lrintf(flt_m * (1.0f / ((float)(1 << 13))));
				}
			}

			assert((0 <= m) && (m <= 1024));
			if (m == 1024)
			{
				e++;
				m = 0;
			}

			assert((e >= 0) && (e <= 31));
			assert((m >= 0) && (m <= 1023));

			basist::half_float result = (basist::half_float)((e << 10) | m);
			return result;
		}
#endif

		union fu32
		{
			uint32_t u;
			float f;
		};

		static BASISU_FORCE_INLINE basist::half_float fast_float_to_half_no_clamp_neg_nan_or_inf(float f)
		{
			assert(!isnan(f) && !isinf(f));
			assert((f >= 0.0f) && (f <= basist::MAX_HALF_FLOAT));

			// Sutract 112 from the exponent, to change the bias from 127 to 15.
			static const fu32 g_f_to_h{ 0x7800000 };

			fu32 fu;

			fu.f = f * g_f_to_h.f;

			uint32_t h = (basist::half_float)((fu.u >> (23 - 10)) & 0x7FFF);

			// round to even
			uint32_t mant = fu.u & 8191; // examine lowest 13 bits
			h += (mant > 4096);

			if (h > basist::MAX_HALF_FLOAT_AS_INT_BITS)
				h = basist::MAX_HALF_FLOAT_AS_INT_BITS;

			return (basist::half_float)h;
		}

		static BASISU_FORCE_INLINE float ftoh(float f)
		{
			//float res = (float)fast_float_to_half_non_neg_no_nan_inf(fabsf(f)) * ((f < 0.0f) ? -1.0f : 1.0f);
			float res = (float)fast_float_to_half_no_clamp_neg_nan_or_inf(fabsf(f)) * ((f < 0.0f) ? -1.0f : 1.0f);
			return res;
		}
		
		// Supports positive and denormals only. No NaN or Inf.
		static BASISU_FORCE_INLINE float fast_half_to_float_pos_not_inf_or_nan(basist::half_float h)
		{
			assert(!basist::half_is_signed(h) && !basist::is_half_inf_or_nan(h));

			// add 112 to the exponent (112+half float's exp bias of 15=float32's bias of 127)
			static const fu32 K = { 0x77800000 };

			fu32 o;
			o.u = h << 13;
			o.f *= K.f;

			return o.f;
		}

		static BASISU_FORCE_INLINE float inv_sqrt(float v)
		{
			union
			{
				float flt;
				uint32_t ui;
			} un;

			un.flt = v;
			un.ui = 0x5F1FFFF9UL - (un.ui >> 1);

			return 0.703952253f * un.flt * (2.38924456f - v * (un.flt * un.flt));
		}

		static const int FAST_BC6H_STD_DEV_THRESH = 256;
		static const int FAST_BC6H_COMPLEX_STD_DEV_THRESH = 512;
		static const int FAST_BC6H_VERY_COMPLEX_STD_DEV_THRESH = 2048;
						
		static double assign_weights_4(
			const vec3F* pFloat_pixels, const float* pPixel_scales,
			uint8_t* pWeights,
			int min_r, int min_g, int min_b,
			int max_r, int max_g, int max_b, int64_t block_max_var, bool try_2subsets_flag, 
			const fast_bc6h_params& params)
		{
			float cr[16], cg[16], cb[16];

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t w = g_bc6h_weights4[i];

				cr[i] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_r * (64 - w) + max_r * w + 32) >> 6));
				cg[i] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_g * (64 - w) + max_g * w + 32) >> 6));
				cb[i] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_b * (64 - w) + max_b * w + 32) >> 6));
			}

			double total_err = 0.0f;

			if (params.m_brute_force_weight4_assignment)
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

					float best_err = basisu::squaref(cr[0] - qr) + basisu::squaref(cg[0] - qg) + basisu::squaref(cb[0] - qb);
					uint32_t best_idx = 0;

					for (uint32_t j = 1; j < 16; j++)
					{
						float rd = cr[j] - qr, gd = cg[j] - qg, bd = cb[j] - qb;
						float e = rd * rd + gd * gd + bd * bd;

						if (e < best_err)
						{
							best_err = e;
							best_idx = j;
						}
					}

					pWeights[i] = (uint8_t)best_idx;

					total_err += best_err * pPixel_scales[i];
				}
			}
			else
			{
				const float dir_r = cr[15] - cr[0], dir_g = cg[15] - cg[0], dir_b = cb[15] - cb[0];

				float dots[16];
				for (uint32_t i = 0; i < 16; i++)
					dots[i] = cr[i] * dir_r + cg[i] * dir_g + cb[i] * dir_b;

				float mid_dots[15];
				bool monotonically_increasing = true;
				for (uint32_t i = 0; i < 15; i++)
				{
					mid_dots[i] = (dots[i] + dots[i + 1]) * .5f;

					if (dots[i] > dots[i + 1])
						monotonically_increasing = false;
				}

				const bool check_more_colors = block_max_var > (FAST_BC6H_VERY_COMPLEX_STD_DEV_THRESH * FAST_BC6H_VERY_COMPLEX_STD_DEV_THRESH * 16); // watch prec

				if (!monotonically_increasing)
				{
					// Seems very rare, not worth optimizing the other cases
					for (uint32_t i = 0; i < 16; i++)
					{
						const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

						float d = qr * dir_r + qg * dir_g + qb * dir_b;

						float best_e = fabsf(d - dots[0]);
						int best_idx = 0;

						for (int j = 1; j < 16; j++)
						{
							float e = fabsf(d - dots[j]);
							if (e < best_e)
							{
								best_e = e;
								best_idx = j;
							}
						}

						assert((best_idx >= 0) && (best_idx <= 15));

						pWeights[i] = (uint8_t)best_idx;

						float err = basisu::squaref(qr - cr[best_idx]) + basisu::squaref(qg - cg[best_idx]) + basisu::squaref(qb - cb[best_idx]);
						total_err += err * pPixel_scales[i];
					}
				}
				else if ((!try_2subsets_flag) || (!check_more_colors))
				{
					for (uint32_t i = 0; i < 16; i++)
					{
						const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

						uint32_t best_idx = 0;

						float d = qr * dir_r + qg * dir_g + qb * dir_b;

						int low = 0;

						int mid = low + 7;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 3;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 1;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low;
						if (d >= mid_dots[mid]) low = mid + 1;

						best_idx = low;
						assert((best_idx <= 15));

						pWeights[i] = (uint8_t)best_idx;

						// Giesen's MRSSE (Mean Relative Sum of Squared Errors). 
						// Our ASTC HDR encoder uses slightly slower approx. MSLE, and it's too late/risky to eval the difference vs. MRSSE on the larger ASTC HDR blocks.
						float err = basisu::squaref(qr - cr[best_idx]) + basisu::squaref(qg - cg[best_idx]) + basisu::squaref(qb - cb[best_idx]);
						total_err += err * pPixel_scales[i];
					}
				}
				else
				{
					for (uint32_t i = 0; i < 16; i++)
					{
						const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

						uint32_t best_idx = 0;

						float d = qr * dir_r + qg * dir_g + qb * dir_b;

						int low = 0;

						int mid = low + 7;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 3;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low + 1;
						if (d >= mid_dots[mid]) low = mid + 1;
						mid = low;
						if (d >= mid_dots[mid]) low = mid + 1;

						best_idx = low;
						assert((best_idx <= 15));

						float err = basisu::squaref(qr - cr[best_idx]) + basisu::squaref(qg - cg[best_idx]) + basisu::squaref(qb - cb[best_idx]);

						{
							int alt_idx = best_idx + 1;
							if (alt_idx > 15)
								alt_idx = 13;

							float alt_err = basisu::squaref(qr - cr[alt_idx]) + basisu::squaref(qg - cg[alt_idx]) + basisu::squaref(qb - cb[alt_idx]);
							if (alt_err < err)
							{
								err = alt_err;
								best_idx = alt_idx;
							}
						}

						{
							int alt_idx2 = best_idx - 1;
							if (alt_idx2 < 0)
								alt_idx2 = 2;
							float alt_err2 = basisu::squaref(qr - cr[alt_idx2]) + basisu::squaref(qg - cg[alt_idx2]) + basisu::squaref(qb - cb[alt_idx2]);
							if (alt_err2 < err)
							{
								err = alt_err2;
								best_idx = alt_idx2;
							}
						}

						pWeights[i] = (uint8_t)best_idx;

						total_err += err * pPixel_scales[i];
					}
				}
			}

			return total_err;
		}

		static void assign_weights_simple_4(
			const basist::half_float* pPixels,
			uint8_t* pWeights,
			int min_r, int min_g, int min_b,
			int max_r, int max_g, int max_b, int64_t block_max_var, 
			const fast_bc6h_params& params)
		{
			BASISU_NOTE_UNUSED(block_max_var);

			float fmin_r = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)min_r);
			float fmin_g = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)min_g);
			float fmin_b = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)min_b);

			float fmax_r = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)max_r);
			float fmax_g = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)max_g);
			float fmax_b = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)max_b);

			float fdir_r = fmax_r - fmin_r;
			float fdir_g = fmax_g - fmin_g;
			float fdir_b = fmax_b - fmin_b;

			float l = inv_sqrt(fdir_r * fdir_r + fdir_g * fdir_g + fdir_b * fdir_b);
			if (l != 0.0f)
			{
				fdir_r *= l;
				fdir_g *= l;
				fdir_b *= l;
			}

			float lf = fmin_r * fdir_r + fmin_g * fdir_g + fmin_b * fdir_b;
			float hf = fmax_r * fdir_r + fmax_g * fdir_g + fmax_b * fdir_b;

			if ((lf >= basist::MAX_HALF_FLOAT) || (hf >= basist::MAX_HALF_FLOAT))
			{
				// v2.1: Can't use the faster half float based tricks below, need some sort of backup
				vec3F float_pixels[16];
				float pixel_scales[16];

				for (uint32_t i = 0; i < 16; i++)
				{
					float_pixels[i].c[0] = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 0]);
					float_pixels[i].c[1] = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 1]);
					float_pixels[i].c[2] = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 2]);
					
					pixel_scales[i] = 1.0f / (basisu::squaref(float_pixels[i].c[0]) + basisu::squaref(float_pixels[i].c[1]) + basisu::squaref(float_pixels[i].c[2]) + (float)MIN_HALF_FLOAT);
				}

				assign_weights_4(
					float_pixels, pixel_scales,
					pWeights,
					min_r, min_g, min_b,
					max_r, max_g, max_b, block_max_var, false,
					params);
				
				return;
			}

			float lr = ftoh(lf);
			float hr = ftoh(hf);

			float frr = (hr == lr) ? 0.0f : (14.93333f / (float)(hr - lr));

			lr = (-lr * frr) + 0.53333f;
			for (uint32_t i = 0; i < 16; i++)
			{
				const float r = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 0]);
				const float g = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 1]);
				const float b = fast_half_to_float_pos_not_inf_or_nan(pPixels[i * 3 + 2]);
				const float w = ftoh(basisu::minimumf(r * fdir_r + g * fdir_g + b * fdir_b, basist::MAX_HALF_FLOAT));

				pWeights[i] = (uint8_t)basisu::clamp((int)(w * frr + lr), 0, 15);
			}
		}

		static void assign_weights3(uint8_t trial_weights[16],
			uint32_t best_pat_bits,
			uint32_t subset_min_r[2], uint32_t subset_min_g[2], uint32_t subset_min_b[2],
			uint32_t subset_max_r[2], uint32_t subset_max_g[2], uint32_t subset_max_b[2],
			const vec3F* pFloat_pixels)
		{
			float subset_cr[2][8], subset_cg[2][8], subset_cb[2][8];

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				const uint32_t min_r = subset_min_r[subset], min_g = subset_min_g[subset], min_b = subset_min_b[subset];
				const uint32_t max_r = subset_max_r[subset], max_g = subset_max_g[subset], max_b = subset_max_b[subset];

				for (uint32_t j = 0; j < 8; j++)
				{
					const uint32_t w = g_bc7_weights3[j];

					subset_cr[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_r * (64 - w) + max_r * w + 32) >> 6));
					subset_cg[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_g * (64 - w) + max_g * w + 32) >> 6));
					subset_cb[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_b * (64 - w) + max_b * w + 32) >> 6));
				} // j

			} // subset

			// TODO: Plane optimization?

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset = (best_pat_bits >> i) & 1;
				const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

				float best_error = basisu::squaref(subset_cr[subset][0] - qr) + basisu::squaref(subset_cg[subset][0] - qg) + basisu::squaref(subset_cb[subset][0] - qb);
				uint32_t best_idx = 0;
								
				for (uint32_t j = 1; j < 8; j++)
				{
					float e = basisu::squaref(subset_cr[subset][j] - qr) + basisu::squaref(subset_cg[subset][j] - qg) + basisu::squaref(subset_cb[subset][j] - qb);
					if (e < best_error)
					{
						best_error = e;
						best_idx = j;
					}
				}

				trial_weights[i] = (uint8_t)best_idx;

			} // i
		}

		static double assign_weights_error_3(uint8_t trial_weights[16],
			uint32_t best_pat_bits,
			uint32_t subset_min_r[2], uint32_t subset_min_g[2], uint32_t subset_min_b[2],
			uint32_t subset_max_r[2], uint32_t subset_max_g[2], uint32_t subset_max_b[2],
			const vec3F* pFloat_pixels, const float* pPixel_scales)
		{
			float subset_cr[2][8], subset_cg[2][8], subset_cb[2][8];

			for (uint32_t subset = 0; subset < 2; subset++)
			{
				const uint32_t min_r = subset_min_r[subset], min_g = subset_min_g[subset], min_b = subset_min_b[subset];
				const uint32_t max_r = subset_max_r[subset], max_g = subset_max_g[subset], max_b = subset_max_b[subset];

				for (uint32_t j = 0; j < 8; j++)
				{
					const uint32_t w = g_bc7_weights3[j];

					subset_cr[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_r * (64 - w) + max_r * w + 32) >> 6));
					subset_cg[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_g * (64 - w) + max_g * w + 32) >> 6));
					subset_cb[subset][j] = fast_half_to_float_pos_not_inf_or_nan((basist::half_float)((min_b * (64 - w) + max_b * w + 32) >> 6));
				} // j

			} // subset

			double trial_error = 0.0f;

			// TODO: Plane optimization?

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset = (best_pat_bits >> i) & 1;
				const float qr = pFloat_pixels[i].c[0], qg = pFloat_pixels[i].c[1], qb = pFloat_pixels[i].c[2];

				float best_error = basisu::squaref(subset_cr[subset][0] - qr) + basisu::squaref(subset_cg[subset][0] - qg) + basisu::squaref(subset_cb[subset][0] - qb);
				uint32_t best_idx = 0;

				for (uint32_t j = 1; j < 8; j++)
				{
					float e = basisu::squaref(subset_cr[subset][j] - qr) + basisu::squaref(subset_cg[subset][j] - qg) + basisu::squaref(subset_cb[subset][j] - qb);
					if (e < best_error)
					{
						best_error = e;
						best_idx = j;
					}
				}

				trial_weights[i] = (uint8_t)best_idx;

				trial_error += best_error * pPixel_scales[i];

			} // i

			return trial_error;
		}

		static basist::vec4F g_bc6h_ls_weights_3[8];
		static basist::vec4F g_bc6h_ls_weights_4[16];
				
		const uint32_t BC6H_NUM_PATS = 32;
		static uint32_t g_bc6h_pats2[BC6H_NUM_PATS];

		static void fast_encode_bc6h_init()
		{
			for (uint32_t i = 0; i < 8; i++)
			{
				const float w = (float)g_bc7_weights3[i] * (1.0f / 64.0f);
				g_bc6h_ls_weights_3[i].set(w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w);
			}

			for (uint32_t i = 0; i < 16; i++)
			{
				const float w = (float)g_bc6h_weights4[i] * (1.0f / 64.0f);
				g_bc6h_ls_weights_4[i].set(w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w);
			}

			for (uint32_t pat_index = 0; pat_index < BC6H_NUM_PATS; pat_index++)
			{
				uint32_t pat_bits = 0;

				for (uint32_t j = 0; j < 16; j++)
					pat_bits |= (g_bc7_partition2[pat_index * 16 + j] << j);

				g_bc6h_pats2[pat_index] = pat_bits;
			}
		}

		static int bc6h_dequantize(int val, int bits)
		{
			assert(val < (1 << bits));

			int result;
			if (bits >= 15)
				result = val;
			else if (!val)
				result = 0;
			else if (val == ((1 << bits) - 1))
				result = 0xFFFF;
			else
				result = ((val << 16) + 0x8000) >> bits;
			return result;
		}

		static inline basist::half_float bc6h_convert_to_half(int val)
		{
			assert(val < 65536);

			// scale by 31/64
			return (basist::half_float)((val * 31) >> 6);
		}

		static void bc6h_quant_dequant_endpoints(uint32_t& min_r, uint32_t& min_g, uint32_t& min_b, uint32_t& max_r, uint32_t& max_g, uint32_t& max_b, int bits) // bits=10
		{
			min_r = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)min_r, bits), bits));
			min_g = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)min_g, bits), bits));
			min_b = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)min_b, bits), bits));

			max_r = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)max_r, bits), bits));
			max_g = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)max_g, bits), bits));
			max_b = bc6h_convert_to_half(bc6h_dequantize(basist::bc6h_half_to_blog((basist::half_float)max_b, bits), bits));
		}

		static void bc6h_quant_endpoints(
			uint32_t min_hr, uint32_t min_hg, uint32_t min_hb, uint32_t max_hr, uint32_t max_hg, uint32_t max_hb,
			uint32_t& min_r, uint32_t& min_g, uint32_t& min_b, uint32_t& max_r, uint32_t& max_g, uint32_t& max_b, 
			int bits)
		{
			min_r = basist::bc6h_half_to_blog((basist::half_float)min_hr, bits);
			min_g = basist::bc6h_half_to_blog((basist::half_float)min_hg, bits);
			min_b = basist::bc6h_half_to_blog((basist::half_float)min_hb, bits);

			max_r = basist::bc6h_half_to_blog((basist::half_float)max_hr, bits);
			max_g = basist::bc6h_half_to_blog((basist::half_float)max_hg, bits);
			max_b = basist::bc6h_half_to_blog((basist::half_float)max_hb, bits);
		}

		static void bc6h_dequant_endpoints(
			uint32_t min_br, uint32_t min_bg, uint32_t min_bb, uint32_t max_br, uint32_t max_bg, uint32_t max_bb,
			uint32_t& min_hr, uint32_t& min_hg, uint32_t& min_hb, uint32_t& max_hr, uint32_t& max_hg, uint32_t& max_hb,
			int bits)
		{
			min_hr = bc6h_convert_to_half(bc6h_dequantize(min_br, bits));
			min_hg = bc6h_convert_to_half(bc6h_dequantize(min_bg, bits));
			min_hb = bc6h_convert_to_half(bc6h_dequantize(min_bb, bits));

			max_hr = bc6h_convert_to_half(bc6h_dequantize(max_br, bits));
			max_hg = bc6h_convert_to_half(bc6h_dequantize(max_bg, bits));
			max_hb = bc6h_convert_to_half(bc6h_dequantize(max_bb, bits));
		}

		static BASISU_FORCE_INLINE int popcount32(uint32_t x) 
		{
#if defined(__EMSCRIPTEN__) || defined(__clang__) || defined(__GNUC__)
			return __builtin_popcount(x);
#elif defined(_MSC_VER)
			return __popcnt(x);
#else
			int count = 0;
			while (x) 
			{
				x &= (x - 1);
				++count;
			}
			return count;
#endif
		}

		static BASISU_FORCE_INLINE int fast_roundf_int(float x)
		{
			return (x >= 0.0f) ? (int)(x + 0.5f) : (int)(x - 0.5f);
		}
												
		static void fast_encode_bc6h_2subsets_pattern(
			uint32_t best_pat_index, uint32_t best_pat_bits,
			const basist::half_float* pPixels, const vec3F* pFloat_pixels, const float* pPixel_scales,
			double& cur_error, basist::bc6h_logical_block& log_blk,
			int64_t block_max_var,
			int mean_r, int mean_g, int mean_b, 
			const fast_bc6h_params& params)
		{
			BASISU_NOTE_UNUSED(block_max_var);
						
			uint32_t subset_means[2][3] = { { 0 } };
			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = (best_pat_bits >> i) & 1;
				const uint32_t r = pPixels[i * 3 + 0], g = pPixels[i * 3 + 1], b = pPixels[i * 3 + 2];
				
				subset_means[subset_index][0] += r;
				subset_means[subset_index][1] += g;
				subset_means[subset_index][2] += b;
			}

			for (uint32_t s = 0; s < 2; s++)
				for (uint32_t c = 0; c < 3; c++)
					subset_means[s][c] = (subset_means[s][c] + 8) / 16;

			int64_t subset_icov[2][6] = { { 0 } };

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = (best_pat_bits >> i) & 1;
				const int r = (int)pPixels[i * 3 + 0] - mean_r, g = (int)pPixels[i * 3 + 1] - mean_g, b = (int)pPixels[i * 3 + 2] - mean_b;

				subset_icov[subset_index][0] += r * r;
				subset_icov[subset_index][1] += r * g;
				subset_icov[subset_index][2] += r * b;
				subset_icov[subset_index][3] += g * g;
				subset_icov[subset_index][4] += g * b;
				subset_icov[subset_index][5] += b * b;
			}

			vec3F subset_axis[2];

			for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
			{
				float cov[6];
				for (uint32_t i = 0; i < 6; i++)
					cov[i] = (float)subset_icov[subset_index][i];

				const float sc = 1.0f / (basisu::maximum(cov[0], cov[3], cov[5]) + basisu::REALLY_SMALL_FLOAT_VAL);
				const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

				const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
				const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
				const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

				float l = basisu::squaref(alt_xr) + basisu::squaref(alt_xg) + basisu::squaref(alt_xb);

				float axis_r = 0.57735027f, axis_g = 0.57735027f, axis_b = 0.57735027f;
				if (fabs(l) >= basisu::SMALL_FLOAT_VAL)
				{
					const float inv_l = inv_sqrt(l);
					axis_r = alt_xr * inv_l;
					axis_g = alt_xg * inv_l;
					axis_b = alt_xb * inv_l;
				}

				subset_axis[subset_index].set(axis_r, axis_g, axis_b);
			} // s
						
			float subset_min_dot[2] = { basisu::BIG_FLOAT_VAL, basisu::BIG_FLOAT_VAL };
			float subset_max_dot[2] = { -basisu::BIG_FLOAT_VAL, -basisu::BIG_FLOAT_VAL };
			int subset_min_idx[2] = { 0 }, subset_max_idx[2] = { 0 };

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint32_t subset_index = (best_pat_bits >> i) & 1;
				const float r = (float)pPixels[i * 3 + 0], g = (float)pPixels[i * 3 + 1], b = (float)pPixels[i * 3 + 2];
				const float dot = r * subset_axis[subset_index].c[0] + g * subset_axis[subset_index].c[1] + b * subset_axis[subset_index].c[2];

				if (dot < subset_min_dot[subset_index])
				{
					subset_min_dot[subset_index] = dot;
					subset_min_idx[subset_index] = i;
				}

				if (dot > subset_max_dot[subset_index])
				{
					subset_max_dot[subset_index] = dot;
					subset_max_idx[subset_index] = i;
				}
			} // i

			uint32_t subset_min_r[2], subset_min_g[2], subset_min_b[2];
			uint32_t subset_max_r[2], subset_max_g[2], subset_max_b[2];

			for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
			{
				const uint32_t min_index = subset_min_idx[subset_index] * 3, max_index = subset_max_idx[subset_index] * 3;

				subset_min_r[subset_index] = pPixels[min_index + 0];
				subset_min_g[subset_index] = pPixels[min_index + 1];
				subset_min_b[subset_index] = pPixels[min_index + 2];

				subset_max_r[subset_index] = pPixels[max_index + 0];
				subset_max_g[subset_index] = pPixels[max_index + 1];
				subset_max_b[subset_index] = pPixels[max_index + 2];

			} // subset_index

			// least squares with unquantized endpoints
			const bool use_ls = true;
			if (use_ls)
			{
				uint8_t trial_weights[16];
				assign_weights3(trial_weights, best_pat_bits, subset_min_r, subset_min_g, subset_min_b, subset_max_r, subset_max_g, subset_max_b, pFloat_pixels);

				float z00[2] = { 0.0f }, z01[2] = { 0.0f }, z10[2] = { 0.0f }, z11[2] = { 0.0f };
				float q00_r[2] = { 0.0f }, q10_r[2] = { 0.0f }, t_r[2] = { 0.0f };
				float q00_g[2] = { 0.0f }, q10_g[2] = { 0.0f }, t_g[2] = { 0.0f };
				float q00_b[2] = { 0.0f }, q10_b[2] = { 0.0f }, t_b[2] = { 0.0f };

				for (uint32_t i = 0; i < 16; i++)
				{
					const uint32_t subset = (best_pat_bits >> i) & 1;

					float r = (float)pPixels[i * 3 + 0];
					float g = (float)pPixels[i * 3 + 1];
					float b = (float)pPixels[i * 3 + 2];

					const uint32_t sel = trial_weights[i];

					z00[subset] += g_bc6h_ls_weights_3[sel][0];
					z10[subset] += g_bc6h_ls_weights_3[sel][1];
					z11[subset] += g_bc6h_ls_weights_3[sel][2];

					float w = g_bc6h_ls_weights_3[sel][3];

					q00_r[subset] += w * r;
					t_r[subset] += r;

					q00_g[subset] += w * g;
					t_g[subset] += g;

					q00_b[subset] += w * b;
					t_b[subset] += b;
				}

				for (uint32_t subset = 0; subset < 2; subset++)
				{
					q10_r[subset] = t_r[subset] - q00_r[subset];
					q10_g[subset] = t_g[subset] - q00_g[subset];
					q10_b[subset] = t_b[subset] - q00_b[subset];

					z01[subset] = z10[subset];

					float det = z00[subset] * z11[subset] - z01[subset] * z10[subset];
					if (fabs(det) >= basisu::SMALL_FLOAT_VAL)
					{
						det = 1.0f / det;

						float iz00 = z11[subset] * det;
						float iz01 = -z01[subset] * det;
						float iz10 = -z10[subset] * det;
						float iz11 = z00[subset] * det;

						subset_max_r[subset] = basisu::clamp<int>(fast_roundf_int(iz00 * q00_r[subset] + iz01 * q10_r[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
						subset_min_r[subset] = basisu::clamp<int>(fast_roundf_int(iz10 * q00_r[subset] + iz11 * q10_r[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

						subset_max_g[subset] = basisu::clamp<int>(fast_roundf_int(iz00 * q00_g[subset] + iz01 * q10_g[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
						subset_min_g[subset] = basisu::clamp<int>(fast_roundf_int(iz10 * q00_g[subset] + iz11 * q10_g[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

						subset_max_b[subset] = basisu::clamp<int>(fast_roundf_int(iz00 * q00_b[subset] + iz01 * q10_b[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
						subset_min_b[subset] = basisu::clamp<int>(fast_roundf_int(iz10 * q00_b[subset] + iz11 * q10_b[subset]), 0, (int)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
					}
				} // subset
			}

			const int BC6H_2SUBSET_ABS_ENDPOINT_MODE = 9;

			int bc6h_mode_index = BC6H_2SUBSET_ABS_ENDPOINT_MODE, num_endpoint_bits = 6;
			uint32_t abs_blog_endpoints[3][4];

			if (params.m_num_diff_endpoint_modes_to_try)
			{
				// ordered from largest base bits to least
				static const int s_bc6h_mode_order2[2] = { 5, 1 }; 
				static const int s_bc6h_mode_order4[4] = { 0, 5, 7, 1 };
				static const int s_bc6h_mode_order9[9] = { 2, 3, 4, 0,  5, 6, 7, 8,  1 };

				uint32_t num_endpoint_modes = 2;
				const int* pBC6H_mode_order = s_bc6h_mode_order2;

				if (params.m_num_diff_endpoint_modes_to_try >= 9)
				{
					num_endpoint_modes = 9;
					pBC6H_mode_order = s_bc6h_mode_order9;
				}
				else if (params.m_num_diff_endpoint_modes_to_try >= 4)
				{
					num_endpoint_modes = 4;
					pBC6H_mode_order = s_bc6h_mode_order4;
				}

				// Find the BC6H mode that will conservatively encode our trial endpoints. The mode chosen will handle any endpoint swaps.
				for (uint32_t bc6h_mode_iter = 0; bc6h_mode_iter < num_endpoint_modes; bc6h_mode_iter++)
				{
					const uint32_t mode = pBC6H_mode_order[bc6h_mode_iter];

					const uint32_t num_base_bits = g_bc6h_mode_sig_bits[mode][0];
					const int base_bitmask = (1 << num_base_bits) - 1;
					BASISU_NOTE_UNUSED(base_bitmask);

					const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[mode][1], g_bc6h_mode_sig_bits[mode][2], g_bc6h_mode_sig_bits[mode][3] };
					//const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

					for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
					{
						bc6h_quant_endpoints(
							subset_min_r[subset_index], subset_min_g[subset_index], subset_min_b[subset_index], subset_max_r[subset_index], subset_max_g[subset_index], subset_max_b[subset_index],
							abs_blog_endpoints[0][subset_index * 2 + 0], abs_blog_endpoints[1][subset_index * 2 + 0], abs_blog_endpoints[2][subset_index * 2 + 0],
							abs_blog_endpoints[0][subset_index * 2 + 1], abs_blog_endpoints[1][subset_index * 2 + 1], abs_blog_endpoints[2][subset_index * 2 + 1],
							num_base_bits);
					}

					uint32_t c;
					for (c = 0; c < 3; c++)
					{
						// a very conservative check because we don't have the weight indices yet, so we don't know how to swap end point values
						// purposely enforcing a symmetric limit here so we can invert any endpoints later if needed
						const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;
						const int min_delta = -max_delta;

						int delta0 = (int)abs_blog_endpoints[c][1] - (int)abs_blog_endpoints[c][0];
						if ((delta0 < min_delta) || (delta0 > max_delta))
							break;

						int delta1 = (int)abs_blog_endpoints[c][2] - (int)abs_blog_endpoints[c][0];
						if ((delta1 < min_delta) || (delta1 > max_delta))
							break;

						int delta2 = (int)abs_blog_endpoints[c][3] - (int)abs_blog_endpoints[c][0];
						if ((delta2 < min_delta) || (delta2 > max_delta))
							break;

						// in case the endpoints are swapped
						int delta3 = (int)abs_blog_endpoints[c][2] - (int)abs_blog_endpoints[c][1];
						if ((delta3 < min_delta) || (delta3 > max_delta))
							break;

						int delta4 = (int)abs_blog_endpoints[c][3] - (int)abs_blog_endpoints[c][1];
						if ((delta4 < min_delta) || (delta4 > max_delta))
							break;
					}

					if (c == 3)
					{
						bc6h_mode_index = mode;
						num_endpoint_bits = num_base_bits;
						break;
					}
				}
			}

			if (bc6h_mode_index == BC6H_2SUBSET_ABS_ENDPOINT_MODE)
			{
				for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
				{
					bc6h_quant_endpoints(
						subset_min_r[subset_index], subset_min_g[subset_index], subset_min_b[subset_index], subset_max_r[subset_index], subset_max_g[subset_index], subset_max_b[subset_index],
						abs_blog_endpoints[0][subset_index * 2 + 0], abs_blog_endpoints[1][subset_index * 2 + 0], abs_blog_endpoints[2][subset_index * 2 + 0],
						abs_blog_endpoints[0][subset_index * 2 + 1], abs_blog_endpoints[1][subset_index * 2 + 1], abs_blog_endpoints[2][subset_index * 2 + 1],
						num_endpoint_bits);
				}
			}

			for (uint32_t subset_index = 0; subset_index < 2; subset_index++)
			{
				bc6h_dequant_endpoints(
					abs_blog_endpoints[0][subset_index * 2 + 0], abs_blog_endpoints[1][subset_index * 2 + 0], abs_blog_endpoints[2][subset_index * 2 + 0],
					abs_blog_endpoints[0][subset_index * 2 + 1], abs_blog_endpoints[1][subset_index * 2 + 1], abs_blog_endpoints[2][subset_index * 2 + 1],
					subset_min_r[subset_index], subset_min_g[subset_index], subset_min_b[subset_index],
					subset_max_r[subset_index], subset_max_g[subset_index], subset_max_b[subset_index], num_endpoint_bits);
			}

			uint8_t trial_weights[16];
			double trial_error = assign_weights_error_3(trial_weights, best_pat_bits, subset_min_r, subset_min_g, subset_min_b, subset_max_r, subset_max_g, subset_max_b, pFloat_pixels, pPixel_scales);

			if (trial_error < cur_error)
			{
				basist::bc6h_logical_block trial_log_blk;

				trial_log_blk.m_mode = bc6h_mode_index;
				trial_log_blk.m_partition_pattern = best_pat_index;
				
				memcpy(trial_log_blk.m_endpoints, abs_blog_endpoints, sizeof(trial_log_blk.m_endpoints));
				memcpy(trial_log_blk.m_weights, trial_weights, 16);
							
				if (trial_log_blk.m_weights[0] & 4)
				{
					for (uint32_t c = 0; c < 3; c++)
						std::swap(trial_log_blk.m_endpoints[c][0], trial_log_blk.m_endpoints[c][1]);

					for (uint32_t i = 0; i < 16; i++)
					{
						const uint32_t subset_index = (best_pat_bits >> i) & 1;
						if (subset_index == 0)
							trial_log_blk.m_weights[i] = 7 - trial_log_blk.m_weights[i];
					}
				}

				const uint32_t subset2_anchor_index = g_bc7_table_anchor_index_second_subset[best_pat_index];
				if (trial_log_blk.m_weights[subset2_anchor_index] & 4)
				{
					for (uint32_t c = 0; c < 3; c++)
						std::swap(trial_log_blk.m_endpoints[c][2], trial_log_blk.m_endpoints[c][3]);

					for (uint32_t i = 0; i < 16; i++)
					{
						const uint32_t subset_index = (best_pat_bits >> i) & 1;
						if (subset_index == 1)
							trial_log_blk.m_weights[i] = 7 - trial_log_blk.m_weights[i];
					}
				}
								
				if (bc6h_mode_index != BC6H_2SUBSET_ABS_ENDPOINT_MODE)
				{
					const uint32_t num_delta_bits[3] = { g_bc6h_mode_sig_bits[bc6h_mode_index][1], g_bc6h_mode_sig_bits[bc6h_mode_index][2], g_bc6h_mode_sig_bits[bc6h_mode_index][3] };
					const int delta_bitmasks[3] = { (1 << num_delta_bits[0]) - 1, (1 << num_delta_bits[1]) - 1, (1 << num_delta_bits[2]) - 1 };

					for (uint32_t c = 0; c < 3; c++)
					{
						const int delta0 = (int)trial_log_blk.m_endpoints[c][1] - (int)trial_log_blk.m_endpoints[c][0];
						const int delta1 = (int)trial_log_blk.m_endpoints[c][2] - (int)trial_log_blk.m_endpoints[c][0];
						const int delta2 = (int)trial_log_blk.m_endpoints[c][3] - (int)trial_log_blk.m_endpoints[c][0];

#ifdef _DEBUG
						// sanity check the final endpoints
						const int max_delta = (1 << (num_delta_bits[c] - 1)) - 1;
						const int min_delta = -(max_delta + 1);
						assert((max_delta - min_delta) == delta_bitmasks[c]);

						if ((delta0 < min_delta) || (delta0 > max_delta) || (delta1 < min_delta) || (delta1 > max_delta) || (delta2 < min_delta) || (delta2 > max_delta))
						{
							assert(0);
							break;
						}
#endif

						trial_log_blk.m_endpoints[c][1] = delta0 & delta_bitmasks[c];
						trial_log_blk.m_endpoints[c][2] = delta1 & delta_bitmasks[c];
						trial_log_blk.m_endpoints[c][3] = delta2 & delta_bitmasks[c];

					} // c
				}

				cur_error = trial_error;
				log_blk = trial_log_blk;
			}
		}

		static void fast_encode_bc6h_2subsets(
			const basist::half_float* pPixels, const vec3F* pFloat_pixels, const float* pPixel_scales,
			double& cur_error, basist::bc6h_logical_block& log_blk,
			int64_t block_max_var,
			int mean_r, int mean_g, int mean_b, float block_axis_r, float block_axis_g, float block_axis_b, 
			const fast_bc6h_params& params)
		{
			assert((params.m_max_2subset_pats_to_try > 0) && (params.m_max_2subset_pats_to_try <= BC6H_NUM_PATS));

			if (params.m_max_2subset_pats_to_try == BC6H_NUM_PATS)
			{
				for (uint32_t i = 0; i < BC6H_NUM_PATS; i++)
				{
					const uint32_t best_pat_index = i;
					const uint32_t best_pat_bits = g_bc6h_pats2[best_pat_index];

					fast_encode_bc6h_2subsets_pattern(
						best_pat_index, best_pat_bits,
						pPixels, pFloat_pixels, pPixel_scales,
						cur_error, log_blk,
						block_max_var,
						mean_r, mean_g, mean_b, params);
				}
				return;
			}
			
			uint32_t desired_pat_bits = 0;
			for (uint32_t i = 0; i < 16; i++)
			{
				float f = (float)(pPixels[i * 3 + 0] - mean_r) * block_axis_r +
					(float)(pPixels[i * 3 + 1] - mean_g) * block_axis_g +
					(float)(pPixels[i * 3 + 2] - mean_b) * block_axis_b;

				desired_pat_bits |= (((f >= 0.0f) ? 1 : 0) << i);
			} // i

			if (params.m_max_2subset_pats_to_try == 1)
			{
				uint32_t best_diff = UINT32_MAX;
				for (uint32_t p = 0; p < BC6H_NUM_PATS; p++)
				{
					const uint32_t bc6h_pat_bits = g_bc6h_pats2[p];

					int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
					int diff_inv = 16 - diff;

					uint32_t min_diff = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
					if (min_diff < best_diff)
						best_diff = min_diff;
				} // p

				const uint32_t best_pat_index = best_diff & 0xFF;
				const uint32_t best_pat_bits = g_bc6h_pats2[best_pat_index];

				fast_encode_bc6h_2subsets_pattern(
					best_pat_index, best_pat_bits,
					pPixels, pFloat_pixels, pPixel_scales,
					cur_error, log_blk,
					block_max_var,
					mean_r, mean_g, mean_b, params);
			}
			else
			{
				assert(params.m_max_2subset_pats_to_try <= BC6H_NUM_PATS);
				uint32_t pat_diffs[BC6H_NUM_PATS];

				for (uint32_t p = 0; p < BC6H_NUM_PATS; p++)
				{
					const uint32_t bc6h_pat_bits = g_bc6h_pats2[p];

					int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
					int diff_inv = 16 - diff;

					pat_diffs[p] = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
				} // p

				std::sort(pat_diffs, pat_diffs + BC6H_NUM_PATS);

				for (uint32_t pat_iter = 0; pat_iter < params.m_max_2subset_pats_to_try; pat_iter++)
				{
					const uint32_t best_pat_index = pat_diffs[pat_iter] & 0xFF;
					const uint32_t best_pat_bits = g_bc6h_pats2[best_pat_index];

					fast_encode_bc6h_2subsets_pattern(
						best_pat_index, best_pat_bits,
						pPixels, pFloat_pixels, pPixel_scales,
						cur_error, log_blk,
						block_max_var,
						mean_r, mean_g, mean_b, params);
				}
			}
		}

		void fast_encode_bc6h(const basist::half_float* pPixels, basist::bc6h_block* pBlock, const fast_bc6h_params &params)
		{
			basist::bc6h_logical_block log_blk;
			log_blk.clear();

			log_blk.m_mode = basist::BC6H_FIRST_1SUBSET_MODE_INDEX;

			uint32_t omin_r = UINT32_MAX, omin_g = UINT32_MAX, omin_b = UINT32_MAX;
			uint32_t omax_r = 0, omax_g = 0, omax_b = 0;
			uint32_t total_r = 0, total_g = 0, total_b = 0;
						
			for (uint32_t i = 0; i < 16; i++)
			{
				uint32_t r = pPixels[i * 3 + 0];
				uint32_t g = pPixels[i * 3 + 1];
				uint32_t b = pPixels[i * 3 + 2];
								
				total_r += r;
				total_g += g;
				total_b += b;

				omin_r = basisu::minimum(omin_r, r);
				omin_g = basisu::minimum(omin_g, g);
				omin_b = basisu::minimum(omin_b, b);

				omax_r = basisu::maximum(omax_r, r);
				omax_g = basisu::maximum(omax_g, g);
				omax_b = basisu::maximum(omax_b, b);
			}

			if ((omin_r == omax_r) && (omin_g == omax_g) && (omin_b == omax_b))
			{
				// Solid block
				log_blk.m_endpoints[0][0] = basist::bc6h_half_to_blog16((basist::half_float)omin_r);
				log_blk.m_endpoints[0][1] = 0;

				log_blk.m_endpoints[1][0] = basist::bc6h_half_to_blog16((basist::half_float)omin_g);
				log_blk.m_endpoints[1][1] = 0;

				log_blk.m_endpoints[2][0] = basist::bc6h_half_to_blog16((basist::half_float)omin_b);
				log_blk.m_endpoints[2][1] = 0;
				
				log_blk.m_mode = 13;
				pack_bc6h_block(*pBlock, log_blk);

				return;
			}
			
			uint32_t min_r, min_g, min_b, max_r, max_g, max_b;

			int mean_r = (total_r + 8) / 16;
			int mean_g = (total_g + 8) / 16;
			int mean_b = (total_b + 8) / 16;

			int64_t icov[6] = { 0, 0, 0, 0, 0, 0 };

			for (uint32_t i = 0; i < 16; i++)
			{
				int r = (int)pPixels[i * 3 + 0] - mean_r;
				int g = (int)pPixels[i * 3 + 1] - mean_g;
				int b = (int)pPixels[i * 3 + 2] - mean_b;

				icov[0] += r * r;
				icov[1] += r * g;
				icov[2] += r * b;
				icov[3] += g * g;
				icov[4] += g * b;
				icov[5] += b * b;
			}
						
			int64_t block_max_var = basisu::maximum(icov[0], icov[3], icov[5]); // not divided by 16, i.e. scaled by 16
			
			if (block_max_var < (FAST_BC6H_STD_DEV_THRESH * FAST_BC6H_STD_DEV_THRESH * 16))
			{
				// Simple block
				min_r = (omax_r - omin_r) / 32 + omin_r;
				min_g = (omax_g - omin_g) / 32 + omin_g;
				min_b = (omax_b - omin_b) / 32 + omin_b;

				max_r = ((omax_r - omin_r) * 31) / 32 + omin_r;
				max_g = ((omax_g - omin_g) * 31) / 32 + omin_g;
				max_b = ((omax_b - omin_b) * 31) / 32 + omin_b;

				assert((max_r < MAX_HALF_FLOAT_AS_INT_BITS) && (max_g < MAX_HALF_FLOAT_AS_INT_BITS) && (max_b < MAX_HALF_FLOAT_AS_INT_BITS));

				bc6h_quant_dequant_endpoints(min_r, min_g, min_b, max_r, max_g, max_b, 10);

				assign_weights_simple_4(pPixels, log_blk.m_weights, min_r, min_g, min_b, max_r, max_g, max_b, block_max_var, params);
				
				log_blk.m_endpoints[0][0] = basist::bc6h_half_to_blog((basist::half_float)min_r, 10);
				log_blk.m_endpoints[0][1] = basist::bc6h_half_to_blog((basist::half_float)max_r, 10);

				log_blk.m_endpoints[1][0] = basist::bc6h_half_to_blog((basist::half_float)min_g, 10);
				log_blk.m_endpoints[1][1] = basist::bc6h_half_to_blog((basist::half_float)max_g, 10);

				log_blk.m_endpoints[2][0] = basist::bc6h_half_to_blog((basist::half_float)min_b, 10);
				log_blk.m_endpoints[2][1] = basist::bc6h_half_to_blog((basist::half_float)max_b, 10);

				if (log_blk.m_weights[0] & 8)
				{
					for (uint32_t i = 0; i < 16; i++)
						log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

					for (uint32_t c = 0; c < 3; c++)
					{
						std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);
					}
				}

				pack_bc6h_block(*pBlock, log_blk);

				return;
			}

			// block_max_var cannot be 0 here, also trace cannot be 0

			// Complex block (edges/strong gradients)
			bool try_2subsets = false;
			double cur_err = 0.0f;
			vec3F float_pixels[16];
			float pixel_scales[16];

			// covar rows are:
			// 0, 1, 2
			// 1, 3, 4
			// 2, 4, 5
			float cov[6];
			for (uint32_t i = 0; i < 6; i++)
				cov[i] = (float)icov[i];

			const float sc = 1.0f / (float)block_max_var;
			const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

			const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
			const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
			const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

			float l = basisu::squaref(alt_xr) + basisu::squaref(alt_xg) + basisu::squaref(alt_xb);

			float axis_r = 0.57735027f, axis_g = 0.57735027f, axis_b = 0.57735027f;
			if (fabs(l) >= basisu::SMALL_FLOAT_VAL)
			{
				const float inv_l = inv_sqrt(l);
				axis_r = alt_xr * inv_l;
				axis_g = alt_xg * inv_l;
				axis_b = alt_xb * inv_l;
			}

			const float tr = axis_r * cov[0] + axis_g * cov[1] + axis_b * cov[2];
			const float tg = axis_r * cov[1] + axis_g * cov[3] + axis_b * cov[4];
			const float tb = axis_r * cov[2] + axis_g * cov[4] + axis_b * cov[5];
			const float principle_axis_var = tr * axis_r + tg * axis_g + tb * axis_b;

			const float inv_principle_axis_var = 1.0f / (principle_axis_var + basisu::REALLY_SMALL_FLOAT_VAL);
			axis_r = tr * inv_principle_axis_var;
			axis_g = tg * inv_principle_axis_var;
			axis_b = tb * inv_principle_axis_var;

			float total_var = cov[0] + cov[3] + cov[5];

			// If the principle axis variance vs. the block's total variance accounts for less than this threshold, it's a "very complex" block that may benefit from 2 subsets.
			const float COMPLEX_BLOCK_PRINCIPLE_AXIS_FRACT_THRESH = .995f;
			try_2subsets = principle_axis_var < (total_var * COMPLEX_BLOCK_PRINCIPLE_AXIS_FRACT_THRESH);

			uint32_t min_idx = 0, max_idx = 0;
			float min_dot = basisu::BIG_FLOAT_VAL, max_dot = -basisu::BIG_FLOAT_VAL;
								
			for (uint32_t i = 0; i < 16; i++)
			{
				float r = (float)pPixels[i * 3 + 0];
				float g = (float)pPixels[i * 3 + 1];
				float b = (float)pPixels[i * 3 + 2];

				float_pixels[i].c[0] = fast_half_to_float_pos_not_inf_or_nan((half_float)r);
				float_pixels[i].c[1] = fast_half_to_float_pos_not_inf_or_nan((half_float)g);
				float_pixels[i].c[2] = fast_half_to_float_pos_not_inf_or_nan((half_float)b);

				pixel_scales[i] = 1.0f / (basisu::squaref(float_pixels[i].c[0]) + basisu::squaref(float_pixels[i].c[1]) + basisu::squaref(float_pixels[i].c[2]) + (float)MIN_HALF_FLOAT);

				float dot = r * axis_r + g * axis_g + b * axis_b;

				if (dot < min_dot)
				{
					min_dot = dot;
					min_idx = i;
				}

				if (dot > max_dot)
				{
					max_dot = dot;
					max_idx = i;
				}
			}

			min_r = pPixels[min_idx * 3 + 0];
			min_g = pPixels[min_idx * 3 + 1];
			min_b = pPixels[min_idx * 3 + 2];

			max_r = pPixels[max_idx * 3 + 0];
			max_g = pPixels[max_idx * 3 + 1];
			max_b = pPixels[max_idx * 3 + 2];

			//assert((max_r < MAX_HALF_FLOAT_AS_INT_BITS) && (max_g < MAX_HALF_FLOAT_AS_INT_BITS) && (max_b < MAX_HALF_FLOAT_AS_INT_BITS));
			assert((max_r <= MAX_HALF_FLOAT_AS_INT_BITS) && (max_g <= MAX_HALF_FLOAT_AS_INT_BITS) && (max_b <= MAX_HALF_FLOAT_AS_INT_BITS));

			bc6h_quant_dequant_endpoints(min_r, min_g, min_b, max_r, max_g, max_b, 10);

			cur_err = assign_weights_4(float_pixels, pixel_scales, log_blk.m_weights, min_r, min_g, min_b, max_r, max_g, max_b, block_max_var, try_2subsets, params);
						
			const uint32_t MAX_LS_PASSES = params.m_hq_ls ? 2 : 1;
			for (uint32_t pass = 0; pass < MAX_LS_PASSES; pass++)
			{
				float z00 = 0.0f, z01 = 0.0f, z10 = 0.0f, z11 = 0.0f;
				float q00_r = 0.0f, q10_r = 0.0f, t_r = 0.0f;
				float q00_g = 0.0f, q10_g = 0.0f, t_g = 0.0f;
				float q00_b = 0.0f, q10_b = 0.0f, t_b = 0.0f;

				for (uint32_t i = 0; i < 16; i++)
				{
					float r = (float)pPixels[i * 3 + 0];
					float g = (float)pPixels[i * 3 + 1];
					float b = (float)pPixels[i * 3 + 2];

					const uint32_t sel = log_blk.m_weights[i];

					z00 += g_bc6h_ls_weights_4[sel][0];
					z10 += g_bc6h_ls_weights_4[sel][1];
					z11 += g_bc6h_ls_weights_4[sel][2];

					float w = g_bc6h_ls_weights_4[sel][3];

					q00_r += w * r;
					t_r += r;

					q00_g += w * g;
					t_g += g;

					q00_b += w * b;
					t_b += b;
				}

				q10_r = t_r - q00_r;
				q10_g = t_g - q00_g;
				q10_b = t_b - q00_b;

				z01 = z10;

				float det = z00 * z11 - z01 * z10;
				if (fabs(det) < basisu::SMALL_FLOAT_VAL)
					break;

				det = 1.0f / det;

				float iz00 = z11 * det;
				float iz01 = -z01 * det;
				float iz10 = -z10 * det;
				float iz11 = z00 * det;

				uint32_t trial_max_r = (int)basisu::clamp<float>(std::round(iz00 * q00_r + iz01 * q10_r), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
				uint32_t trial_min_r = (int)basisu::clamp<float>(std::round(iz10 * q00_r + iz11 * q10_r), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

				uint32_t trial_max_g = (int)basisu::clamp<float>(std::round(iz00 * q00_g + iz01 * q10_g), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
				uint32_t trial_min_g = (int)basisu::clamp<float>(std::round(iz10 * q00_g + iz11 * q10_g), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

				uint32_t trial_max_b = (int)basisu::clamp<float>(std::round(iz00 * q00_b + iz01 * q10_b), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);
				uint32_t trial_min_b = (int)basisu::clamp<float>(std::round(iz10 * q00_b + iz11 * q10_b), 0, (float)basist::MAX_BC6H_HALF_FLOAT_AS_UINT);

				bc6h_quant_dequant_endpoints(trial_min_r, trial_min_g, trial_min_b, trial_max_r, trial_max_g, trial_max_b, 10);

				uint8_t trial_weights[16];
				double trial_err = assign_weights_4(float_pixels, pixel_scales, trial_weights, trial_min_r, trial_min_g, trial_min_b, trial_max_r, trial_max_g, trial_max_b, block_max_var, try_2subsets, params);

				if (trial_err < cur_err)
				{
					cur_err = trial_err;

					min_r = trial_min_r;
					max_r = trial_max_r;

					min_g = trial_min_g;
					max_g = trial_max_g;

					min_b = trial_min_b;
					max_b = trial_max_b;
												
					memcpy(log_blk.m_weights, trial_weights, 16);
				}
				else
				{
					break;
				}

			} // pass

#if 0
			//if (full_flag)
			if ((try_2subsets) && (block_max_var > (FAST_BC6H_COMPLEX_STD_DEV_THRESH * FAST_BC6H_COMPLEX_STD_DEV_THRESH * 16)))
			{
				min_r = 0;
				max_r = 0;
				min_g = 0;
				max_g = 0;
				min_b = 0;
				max_b = 0;
			}
#endif

			log_blk.m_endpoints[0][0] = basist::bc6h_half_to_blog((basist::half_float)min_r, 10);
			log_blk.m_endpoints[0][1] = basist::bc6h_half_to_blog((basist::half_float)max_r, 10);

			log_blk.m_endpoints[1][0] = basist::bc6h_half_to_blog((basist::half_float)min_g, 10);
			log_blk.m_endpoints[1][1] = basist::bc6h_half_to_blog((basist::half_float)max_g, 10);

			log_blk.m_endpoints[2][0] = basist::bc6h_half_to_blog((basist::half_float)min_b, 10);
			log_blk.m_endpoints[2][1] = basist::bc6h_half_to_blog((basist::half_float)max_b, 10);

			if (log_blk.m_weights[0] & 8)
			{
				for (uint32_t i = 0; i < 16; i++)
					log_blk.m_weights[i] = 15 - log_blk.m_weights[i];

				for (uint32_t c = 0; c < 3; c++)
				{
					std::swap(log_blk.m_endpoints[c][0], log_blk.m_endpoints[c][1]);
				}
			}
			
			if ((params.m_max_2subset_pats_to_try > 0) && ((try_2subsets) && (block_max_var > (FAST_BC6H_COMPLEX_STD_DEV_THRESH * FAST_BC6H_COMPLEX_STD_DEV_THRESH * 16))))
			{
				fast_encode_bc6h_2subsets(pPixels, float_pixels, pixel_scales, cur_err, log_blk, block_max_var, mean_r, mean_g, mean_b, axis_r, axis_g, axis_b, params);
			}

			pack_bc6h_block(*pBlock, log_blk);
		}

		bool decode_6x6_hdr(const uint8_t *pComp_data, uint32_t comp_data_size, basisu::vector2D<astc_helpers::astc_block>& decoded_blocks, uint32_t& width, uint32_t& height)
		{
			const uint32_t BLOCK_W = 6, BLOCK_H = 6;

			//interval_timer tm;
			//tm.start();

			width = 0;
			height = 0;

			if (comp_data_size <= (2 * 3 + 1))
				return false;

			basist::bitwise_decoder decoder;
			if (!decoder.init(pComp_data, comp_data_size))
				return false;

			bool orig_behavior = false;

			uint32_t hdr_sig = decoder.get_bits(16);
			if (hdr_sig == UASTC_6x6_HDR_SIG0)
				orig_behavior = true;
			else if (hdr_sig != UASTC_6x6_HDR_SIG1)
				return false;

			width = decoder.get_bits(16);
			height = decoder.get_bits(16);

			if (!width || !height || (width > MAX_ASTC_HDR_6X6_DIM) || (height > MAX_ASTC_HDR_6X6_DIM))
				return false;

			const uint32_t num_blocks_x = (width + BLOCK_W - 1) / BLOCK_W;
			const uint32_t num_blocks_y = (height + BLOCK_H - 1) / BLOCK_H;

			const uint32_t total_blocks = num_blocks_x * num_blocks_y;

			decoded_blocks.resize(num_blocks_x, num_blocks_y);
			//memset(decoded_blocks.get_ptr(), 0, decoded_blocks.size_in_bytes());

			// These are the decoded log blocks, NOT the output log blocks.
			basisu::vector2D<astc_helpers::log_astc_block> decoded_log_blocks(num_blocks_x, REUSE_MAX_BUFFER_ROWS);
			memset(decoded_log_blocks.get_ptr(), 0, decoded_log_blocks.size_in_bytes());

			uint32_t cur_bx = 0, cur_by = 0;
			int cur_row_index = 0;

			uint32_t step_counter = 0;
			BASISU_NOTE_UNUSED(step_counter);

			while (cur_by < num_blocks_y)
			{
				step_counter++;

				//if ((cur_bx == 9) && (cur_by == 13))
				//	printf("!");

#if SYNC_MARKERS
				uint32_t mk = decoder.get_bits(16);
				if (mk != 0xDEAD)
				{
					printf("!");
					assert(0);
					return false;
				}
#endif
				if (decoder.get_bits_remaining() < 1)
					return false;

				encoding_type et = encoding_type::cBlock;

				uint32_t b0 = decoder.get_bits(1);
				if (!b0)
				{
					uint32_t b1 = decoder.get_bits(1);
					if (b1)
						et = encoding_type::cReuse;
					else
					{
						uint32_t b2 = decoder.get_bits(1);
						if (b2)
							et = encoding_type::cSolid;
						else
							et = encoding_type::cRun;
					}
				}

				switch (et)
				{
				case encoding_type::cRun:
				{
					if (!cur_bx && !cur_by)
						return false;

					const uint32_t run_len = decoder.decode_vlc(5) + 1;

					uint32_t num_blocks_remaining = total_blocks - (cur_bx + cur_by * num_blocks_x);
					if (run_len > num_blocks_remaining)
						return false;

					uint32_t prev_bx = cur_bx, prev_by = cur_by;

					if (cur_bx)
						prev_bx--;
					else
					{
						prev_bx = num_blocks_x - 1;
						prev_by--;
					}

					const astc_helpers::log_astc_block& prev_log_blk = decoded_log_blocks(prev_bx, calc_row_index(cur_by, prev_by, cur_row_index));
					const astc_helpers::astc_block& prev_phys_blk = decoded_blocks(prev_bx, prev_by);

					assert((prev_log_blk.m_user_mode == 255) || (prev_log_blk.m_user_mode < TOTAL_BLOCK_MODE_DECS));

					for (uint32_t i = 0; i < run_len; i++)
					{
						decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index)) = prev_log_blk;
						decoded_blocks(cur_bx, cur_by) = prev_phys_blk;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}
					}

					break;
				}
				case encoding_type::cSolid:
				{
					const basist::half_float rh = (basist::half_float)decoder.get_bits(15);
					const basist::half_float gh = (basist::half_float)decoder.get_bits(15);
					const basist::half_float bh = (basist::half_float)decoder.get_bits(15);

					astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));

					log_blk.clear();
					log_blk.m_user_mode = 255;
					log_blk.m_solid_color_flag_hdr = true;
					log_blk.m_solid_color[0] = rh;
					log_blk.m_solid_color[1] = gh;
					log_blk.m_solid_color[2] = bh;
					log_blk.m_solid_color[3] = basist::float_to_half(1.0f);

					bool status = astc_helpers::pack_astc_block(decoded_blocks(cur_bx, cur_by), log_blk);
					if (!status)
						return false;

					cur_bx++;
					if (cur_bx == num_blocks_x)
					{
						cur_bx = 0;
						cur_by++;
						cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
					}

					break;
				}
				case encoding_type::cReuse:
				{
					if (!cur_bx && !cur_by)
						return false;

					const uint32_t reuse_delta_index = decoder.get_bits(REUSE_XY_DELTA_BITS);

					const int reuse_delta_x = g_reuse_xy_deltas[reuse_delta_index].m_x;
					const int reuse_delta_y = g_reuse_xy_deltas[reuse_delta_index].m_y;

					const int prev_bx = cur_bx + reuse_delta_x, prev_by = cur_by + reuse_delta_y;
					if ((prev_bx < 0) || (prev_bx >= (int)num_blocks_x))
						return false;
					if (prev_by < 0)
						return false;

					const astc_helpers::log_astc_block& prev_log_blk = decoded_log_blocks(prev_bx, calc_row_index(cur_by, prev_by, cur_row_index));

					if (prev_log_blk.m_solid_color_flag_hdr)
						return false;
					assert(prev_log_blk.m_user_mode < TOTAL_BLOCK_MODE_DECS);

					astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
					astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

					log_blk = prev_log_blk;

					const uint32_t total_grid_weights = log_blk.m_grid_width * log_blk.m_grid_height * (log_blk.m_dual_plane ? 2 : 1);

					bool status = decode_values(decoder, total_grid_weights, log_blk.m_weight_ise_range, log_blk.m_weights);
					if (!status)
						return false;

#if 0
					const astc_helpers::astc_block& prev_phys_blk = decoded_blocks(prev_bx, prev_by);

					astc_helpers::log_astc_block decomp_blk;
					status = astc_helpers::unpack_block(&prev_phys_blk, decomp_blk, BLOCK_W, BLOCK_H);
					if (!status)
						return false;

					uint8_t transcode_weights[MAX_BLOCK_W * MAX_BLOCK_H * 2];
					requantize_astc_weights(total_grid_weights, log_blk.m_weights, log_blk.m_weight_ise_range, transcode_weights, decomp_blk.m_weight_ise_range);

					copy_weight_grid(log_blk.m_dual_plane, log_blk.m_grid_width, log_blk.m_grid_height, transcode_weights, decomp_blk, orig_behavior);
#else
					assert(log_blk.m_user_mode < TOTAL_BLOCK_MODE_DECS);
					const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)log_blk.m_user_mode];
					const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

					assert(bmd.m_grid_x == log_blk.m_grid_width && bmd.m_grid_y == log_blk.m_grid_height);
					assert(bmd.m_dp == log_blk.m_dual_plane);
					assert(bmd.m_cem == log_blk.m_color_endpoint_modes[0]);
					assert(bmd.m_num_partitions == log_blk.m_num_partitions);
					assert(bmd.m_dp_channel == log_blk.m_color_component_selector);

					// important: bmd.m_weight_ise_range/m_endpoint_ise_range may not match the logical block's due to deltas.

					astc_helpers::log_astc_block decomp_blk;
					decomp_blk.clear();
					decomp_blk.m_dual_plane = bmd.m_dp;
					decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;
					decomp_blk.m_partition_id = log_blk.m_partition_id;

					decomp_blk.m_num_partitions = (uint8_t)bmd.m_num_partitions;

					for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
						decomp_blk.m_color_endpoint_modes[p] = (uint8_t)bmd.m_cem;

					decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
					decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;

					for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
						requantize_ise_endpoints(bmd.m_cem, log_blk.m_endpoint_ise_range, log_blk.m_endpoints + num_endpoint_values * p, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints + num_endpoint_values * p);

					uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
					requantize_astc_weights(total_grid_weights, log_blk.m_weights, log_blk.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

					copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk, orig_behavior);
#endif
					status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
					if (!status)
						return false;

					cur_bx++;
					if (cur_bx == num_blocks_x)
					{
						cur_bx = 0;
						cur_by++;
						cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
					}

					break;
				}
				case encoding_type::cBlock:
				{
					const block_mode bm = (block_mode)decoder.decode_truncated_binary((uint32_t)block_mode::cBMTotalModes);
					const endpoint_mode em = (endpoint_mode)decoder.decode_truncated_binary((uint32_t)endpoint_mode::cTotal);

					switch (em)
					{
					case endpoint_mode::cUseLeft:
					case endpoint_mode::cUseUpper:
					{
						int neighbor_bx = cur_bx, neighbor_by = cur_by;

						if (em == endpoint_mode::cUseLeft)
							neighbor_bx--;
						else
							neighbor_by--;

						if ((neighbor_bx < 0) || (neighbor_by < 0))
							return false;

						const astc_helpers::log_astc_block& neighbor_blk = decoded_log_blocks(neighbor_bx, calc_row_index(cur_by, neighbor_by, cur_row_index));
						if (!neighbor_blk.m_color_endpoint_modes[0])
							return false;

						const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)bm];
						const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

						if (bmd.m_cem != neighbor_blk.m_color_endpoint_modes[0])
							return false;

						astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
						astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

						log_blk.clear();
						assert((uint32_t)bm <= UINT8_MAX);
						log_blk.m_user_mode = (uint8_t)bm;
						log_blk.m_num_partitions = 1;
						log_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						// Important: Notice how we're copying the neighbor's endpoint ISE range. Not using the mode's endpoint ISE range here.
						// This is to avoid introducing more quantization error.
						log_blk.m_endpoint_ise_range = neighbor_blk.m_endpoint_ise_range;
						log_blk.m_weight_ise_range = (uint8_t)bmd.m_weight_ise_range;
						log_blk.m_grid_width = (uint8_t)bmd.m_grid_x;
						log_blk.m_grid_height = (uint8_t)bmd.m_grid_y;
						log_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						log_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						memcpy(log_blk.m_endpoints, neighbor_blk.m_endpoints, num_endpoint_values);

						const uint32_t total_grid_weights = bmd.m_grid_x * bmd.m_grid_y * (bmd.m_dp ? 2 : 1);

						bool status = decode_values(decoder, total_grid_weights, bmd.m_weight_ise_range, log_blk.m_weights);
						if (!status)
							return false;

						astc_helpers::log_astc_block decomp_blk;
						decomp_blk.clear();

						decomp_blk.m_num_partitions = 1;
						decomp_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
						decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;
						decomp_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						requantize_ise_endpoints(bmd.m_cem, log_blk.m_endpoint_ise_range, log_blk.m_endpoints, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints);

						uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
						requantize_astc_weights(total_grid_weights, log_blk.m_weights, bmd.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

						copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk, orig_behavior);

						status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
						if (!status)
							return false;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}

						break;
					}
					case endpoint_mode::cUseLeftDelta:
					case endpoint_mode::cUseUpperDelta:
					{
						int neighbor_bx = cur_bx, neighbor_by = cur_by;

						if (em == endpoint_mode::cUseLeftDelta)
							neighbor_bx--;
						else
							neighbor_by--;

						if ((neighbor_bx < 0) || (neighbor_by < 0))
							return false;

						const astc_helpers::log_astc_block& neighbor_blk = decoded_log_blocks(neighbor_bx, calc_row_index(cur_by, neighbor_by, cur_row_index));
						if (!neighbor_blk.m_color_endpoint_modes[0])
							return false;

						const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)bm];
						const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

						if (bmd.m_cem != neighbor_blk.m_color_endpoint_modes[0])
							return false;

						astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
						astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

						log_blk.clear();
						assert((uint32_t)bm <= UINT8_MAX);
						log_blk.m_user_mode = (uint8_t)bm;
						log_blk.m_num_partitions = 1;
						log_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						log_blk.m_dual_plane = bmd.m_dp;
						log_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						log_blk.m_endpoint_ise_range = (uint8_t)bmd.m_endpoint_ise_range;
						requantize_ise_endpoints(bmd.m_cem, neighbor_blk.m_endpoint_ise_range, neighbor_blk.m_endpoints, bmd.m_endpoint_ise_range, log_blk.m_endpoints);

						const int total_endpoint_delta_vals = 1 << NUM_ENDPOINT_DELTA_BITS;
						const int low_delta_limit = -(total_endpoint_delta_vals / 2); // high_delta_limit = (total_endpoint_delta_vals / 2) - 1;

						const auto& ise_to_rank = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_rank;
						const auto& rank_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_rank_to_ISE;
						const int total_endpoint_levels = astc_helpers::get_ise_levels(log_blk.m_endpoint_ise_range);

						for (uint32_t i = 0; i < num_endpoint_values; i++)
						{
							int cur_val = ise_to_rank[log_blk.m_endpoints[i]];

							int delta = (int)decoder.get_bits(NUM_ENDPOINT_DELTA_BITS) + low_delta_limit;

							cur_val += delta;
							if ((cur_val < 0) || (cur_val >= total_endpoint_levels))
								return false;

							log_blk.m_endpoints[i] = rank_to_ise[cur_val];
						}

						log_blk.m_weight_ise_range = (uint8_t)bmd.m_weight_ise_range;
						log_blk.m_grid_width = (uint8_t)bmd.m_grid_x;
						log_blk.m_grid_height = (uint8_t)bmd.m_grid_y;

						const uint32_t total_grid_weights = bmd.m_grid_x * bmd.m_grid_y * (bmd.m_dp ? 2 : 1);

						bool status = decode_values(decoder, total_grid_weights, bmd.m_weight_ise_range, log_blk.m_weights);
						if (!status)
							return false;

						astc_helpers::log_astc_block decomp_blk;
						decomp_blk.clear();

						decomp_blk.m_num_partitions = 1;
						decomp_blk.m_color_endpoint_modes[0] = (uint8_t)bmd.m_cem;
						decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
						decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;
						decomp_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						requantize_ise_endpoints(bmd.m_cem, log_blk.m_endpoint_ise_range, log_blk.m_endpoints, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints);

						uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
						requantize_astc_weights(total_grid_weights, log_blk.m_weights, bmd.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

						copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk, orig_behavior);

						status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
						if (!status)
							return false;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}

						break;
					}
					case endpoint_mode::cRaw:
					{
						const block_mode_desc& bmd = g_block_mode_descs[(uint32_t)bm];

						const uint32_t num_endpoint_values = get_num_endpoint_vals(bmd.m_cem);

						astc_helpers::log_astc_block& log_blk = decoded_log_blocks(cur_bx, calc_row_index(cur_by, cur_by, cur_row_index));
						astc_helpers::astc_block& phys_blk = decoded_blocks(cur_bx, cur_by);

						log_blk.clear();

						assert((uint32_t)bm <= UINT8_MAX);
						log_blk.m_user_mode = (uint8_t)bm;

						log_blk.m_num_partitions = (uint8_t)bmd.m_num_partitions;

						for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
							log_blk.m_color_endpoint_modes[p] = (uint8_t)bmd.m_cem;

						log_blk.m_endpoint_ise_range = (uint8_t)bmd.m_endpoint_ise_range;
						log_blk.m_weight_ise_range = (uint8_t)bmd.m_weight_ise_range;

						log_blk.m_grid_width = (uint8_t)bmd.m_grid_x;
						log_blk.m_grid_height = (uint8_t)bmd.m_grid_y;
						log_blk.m_dual_plane = (uint8_t)bmd.m_dp;
						log_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;

						if (bmd.m_num_partitions == 2)
						{
							const uint32_t unique_partition_index = decoder.decode_truncated_binary(NUM_UNIQUE_PARTITIONS2);
							log_blk.m_partition_id = (uint16_t)g_part2_unique_index_to_seed[unique_partition_index];
						}
						else if (bmd.m_num_partitions == 3)
						{
							const uint32_t unique_partition_index = decoder.decode_truncated_binary(NUM_UNIQUE_PARTITIONS3);
							log_blk.m_partition_id = (uint16_t)g_part3_unique_index_to_seed[unique_partition_index];
						}

						bool status = decode_values(decoder, num_endpoint_values * bmd.m_num_partitions, bmd.m_endpoint_ise_range, log_blk.m_endpoints);
						if (!status)
							return false;

						const uint32_t total_grid_weights = bmd.m_grid_x * bmd.m_grid_y * (bmd.m_dp ? 2 : 1);

						status = decode_values(decoder, total_grid_weights, bmd.m_weight_ise_range, log_blk.m_weights);
						if (!status)
							return false;

						astc_helpers::log_astc_block decomp_blk;
						decomp_blk.clear();
						decomp_blk.m_dual_plane = bmd.m_dp;
						decomp_blk.m_color_component_selector = (uint8_t)bmd.m_dp_channel;
						decomp_blk.m_partition_id = log_blk.m_partition_id;

						decomp_blk.m_num_partitions = (uint8_t)bmd.m_num_partitions;

						for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
							decomp_blk.m_color_endpoint_modes[p] = (uint8_t)bmd.m_cem;

						decomp_blk.m_endpoint_ise_range = (uint8_t)bmd.m_transcode_endpoint_ise_range;
						decomp_blk.m_weight_ise_range = (uint8_t)bmd.m_transcode_weight_ise_range;

						for (uint32_t p = 0; p < bmd.m_num_partitions; p++)
							requantize_ise_endpoints(bmd.m_cem, bmd.m_endpoint_ise_range, log_blk.m_endpoints + num_endpoint_values * p, bmd.m_transcode_endpoint_ise_range, decomp_blk.m_endpoints + num_endpoint_values * p);

						uint8_t transcode_weights[BLOCK_W * BLOCK_H * 2];
						requantize_astc_weights(total_grid_weights, log_blk.m_weights, bmd.m_weight_ise_range, transcode_weights, bmd.m_transcode_weight_ise_range);

						copy_weight_grid(bmd.m_dp, bmd.m_grid_x, bmd.m_grid_y, transcode_weights, decomp_blk, orig_behavior);

						status = astc_helpers::pack_astc_block(phys_blk, decomp_blk);
						if (!status)
							return false;

						cur_bx++;
						if (cur_bx == num_blocks_x)
						{
							cur_bx = 0;
							cur_by++;
							cur_row_index = (cur_row_index + 1) % REUSE_MAX_BUFFER_ROWS;
						}

						break;
					}
					default:
					{
						assert(0);
						return false;
					}
					}

					break;
				}
				default:
				{
					assert(0);
					return false;
				}
				}
			}

			if (decoder.get_bits(16) != 0xA742)
			{
				//fmt_error_printf("End marker not found!\n");
				return false;
			}

			//fmt_printf("Total decode_file() time: {} secs\n", tm.get_elapsed_secs());

			return true;
		}

	} // namespace astc_6x6_hdr

#endif // BASISD_SUPPORT_UASTC_HDR

#if BASISD_SUPPORT_XUASTC
namespace astc_ldr_t
{
	bool g_initialized;
	astc_block_grid_data_hash_t g_astc_block_grid_data_hash;

	// Used for quickly bumping up or down quantized, 2 complement+shifted base+offset delta values without disturbing the MSB.
	static basisu::vector<uint8_t> g_base_ofs_nudges[astc_helpers::BISE_256_LEVELS + 1][2]; // [endpoint_ise_range][pos=0, neg=1]

	const int s_unique_ldr_index_to_astc_cem[6] =
	{
		astc_helpers::CEM_LDR_LUM_DIRECT,
		astc_helpers::CEM_LDR_LUM_ALPHA_DIRECT,
		astc_helpers::CEM_LDR_RGB_BASE_SCALE,
		astc_helpers::CEM_LDR_RGB_DIRECT,
		astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A,
		astc_helpers::CEM_LDR_RGBA_DIRECT
	};
		
	static void compute_base_ofs_requantize_tabs()
	{
		for (uint32_t e_ise_range = astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE; e_ise_range <= astc_helpers::LAST_VALID_ENDPOINT_ISE_RANGE; e_ise_range++)
		{
			const uint32_t num_levels = astc_helpers::get_ise_levels(e_ise_range);

			for (uint32_t pos_or_neg = 0; pos_or_neg < 2; pos_or_neg++)
			{
				g_base_ofs_nudges[e_ise_range][pos_or_neg].resize(num_levels);

				const int delta = pos_or_neg ? -1 : 1;

				for (uint32_t cur_ise = 0; cur_ise < num_levels; cur_ise++)
				{
					int cur_dequant = astc_helpers::g_dequant_tables.get_endpoint_tab(e_ise_range).m_ISE_to_val[cur_ise];

					int cur_a = cur_dequant, cur_b = 0;
					astc_helpers::bit_transfer_signed_dec(cur_a, cur_b);

					int best_err = INT_MAX;
					uint32_t best_trial_ise = 0;

					for (uint32_t trial_ise = 0; trial_ise < num_levels; trial_ise++)
					{
						int trial_dequant = astc_helpers::g_dequant_tables.get_endpoint_tab(e_ise_range).m_ISE_to_val[trial_ise];

						int trial_a = trial_dequant, trial_b = 0;
						astc_helpers::bit_transfer_signed_dec(trial_a, trial_b);

						// ensure the transferred bit hasn't changed
						if (cur_b != trial_b)
							continue;

						// skip if the decoded delta hasn't changed at all
						if (trial_a == cur_a)
							continue;

						// do they want to nudge neg or pos
						if (delta < 0)
						{
							// neg nudge, but trial delta is higher
							if (trial_a > cur_a)
								continue;
						}
						else
						{
							// pos nudge, but trial delta is lower
							if (trial_a < cur_a)
								continue;
						}

						int e = basisu::iabs(trial_a - cur_a);
						if (e < best_err)
						{
							best_err = e;
							best_trial_ise = trial_ise;
						}
					} // trial_ise

					if (best_err == INT_MAX)
					{
						//fmt_printf("Failed nudge: eise:{}, delta: {}, curise:{}, cura:{}, curb:{}\n", e_ise_range, delta, cur_ise, cur_a, cur_b);

						// Failed to nudge, leave it unchanged
						best_trial_ise = cur_ise;
					}

					g_base_ofs_nudges[e_ise_range][pos_or_neg][cur_ise] = (uint8_t)best_trial_ise;

				} // cur_ise

			} // pos_or_neg

		} // e_ise_range
	}

	void init()
	{
		if (g_initialized)
			return;

		g_initialized = true;

		init_astc_block_grid_data_hash();

		compute_base_ofs_requantize_tabs();
	}
		
	color_rgba blue_contract_enc(color_rgba orig, bool& did_clamp, int encoded_b)
	{
		color_rgba enc;

		int tr = orig.r * 2 - encoded_b;
		int tg = orig.g * 2 - encoded_b;
		if ((tr < 0) || (tr > 255) || (tg < 0) || (tg > 255))
			did_clamp = true;

		enc.r = (uint8_t)basisu::clamp<int>(tr, 0, 255);
		enc.g = (uint8_t)basisu::clamp<int>(tg, 0, 255);
		enc.b = (uint8_t)orig.b;
		enc.a = orig.a;
		return enc;
	}

	color_rgba blue_contract_dec(int enc_r, int enc_g, int enc_b, int enc_a)
	{
		color_rgba dec;
		dec.r = (uint8_t)((enc_r + enc_b) >> 1);
		dec.g = (uint8_t)((enc_g + enc_b) >> 1);
		dec.b = (uint8_t)enc_b;
		dec.a = (uint8_t)enc_a;
		return dec;
	}
		
	static inline int quant_preserve2(uint32_t ise_range, uint32_t v)
	{
		if (ise_range == astc_helpers::BISE_256_LEVELS)
			return v;

		assert(ise_range >= astc_helpers::BISE_6_LEVELS);

		return basist::astc_6x6_hdr::g_quantize_tables_preserve2[ise_range][v];
	}

	//----------------------------------------------------------------------------------
	// Requantize endpoints, but preserves blue contraction and base+ofs bits as much as possible.

	// Blue contraction should be preserved almost always if quantizing down, except with base+ofs (extremely to incredibly rare).
	// endpoints never swapped for base+ofs
	// NOTE: Cannot use any floating point math for determinism across compilers.
	bool requantize_ise_endpoints(uint32_t cem,
		uint32_t src_ise_endpoint_range, const uint8_t* pSrc_endpoints,
		uint32_t dst_ise_endpoint_range, uint8_t* pDst_endpoints)
	{
		if (!astc_helpers::is_cem_ldr(cem))
		{
			assert(0);
			return false;
		}

		const uint32_t num_endpoint_vals = astc_helpers::get_num_cem_values(cem);
		assert(num_endpoint_vals <= astc_helpers::MAX_CEM_ENDPOINT_VALS);

		if (src_ise_endpoint_range == dst_ise_endpoint_range)
		{
			memcpy(pDst_endpoints, pSrc_endpoints, num_endpoint_vals);
			return true;
		}

		uint8_t dequantized_src_vals_temp[astc_helpers::MAX_CEM_ENDPOINT_VALS];
		const uint8_t* pDequantized_src_vals = pSrc_endpoints;

		if (src_ise_endpoint_range != astc_helpers::BISE_256_LEVELS)
		{
			const auto& dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(src_ise_endpoint_range).m_ISE_to_val;

			for (uint32_t i = 0; i < num_endpoint_vals; i++)
				dequantized_src_vals_temp[i] = dequant_tab[pSrc_endpoints[i]];

			pDequantized_src_vals = dequantized_src_vals_temp;
		}

		if (dst_ise_endpoint_range == astc_helpers::BISE_256_LEVELS)
		{
			memcpy(pDst_endpoints, pDequantized_src_vals, num_endpoint_vals);
			return true;
		}

		const auto& dst_quant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_val_to_ise;

		if ((cem == astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET) || (cem == astc_helpers::CEM_LDR_RGBA_BASE_PLUS_OFFSET))
		{
			const auto& dst_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_ISE_to_val;

			for (uint32_t i = 0; i < num_endpoint_vals; i++)
			{
				// preserve v1,v3,v5,v7, which have 2 MSB's that need to be preserved during requant
				if (i & 1)
					pDst_endpoints[i] = (uint8_t)quant_preserve2(dst_ise_endpoint_range, pDequantized_src_vals[i]);
				else
					pDst_endpoints[i] = dst_quant_tab[pDequantized_src_vals[i]];
			}

#ifdef _DEBUG
			{
				const auto& src_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(src_ise_endpoint_range).m_ISE_to_val;

				// ensure MSB's did not change
				for (uint32_t i = 0; i < num_endpoint_vals; i++)
				{
					int src_v = src_dequant_tab[pSrc_endpoints[i]];
					int dst_v = dst_dequant_tab[pDst_endpoints[i]];
					assert((src_v & 128) == (dst_v & 128));

					if (i & 1)
					{
						assert((src_v & 64) == (dst_v & 64));
					}
				}
			}
#endif

			const bool src_used_blue_contract = astc_helpers::used_blue_contraction(cem, pSrc_endpoints, src_ise_endpoint_range);
			// src delta sum was < 0 if it used blue contraction, >= 0 if it did NOT

			int v0 = dst_dequant_tab[pDst_endpoints[0]], v1 = dst_dequant_tab[pDst_endpoints[1]];
			int v2 = dst_dequant_tab[pDst_endpoints[2]], v3 = dst_dequant_tab[pDst_endpoints[3]];
			int v4 = dst_dequant_tab[pDst_endpoints[4]], v5 = dst_dequant_tab[pDst_endpoints[5]];

			astc_helpers::bit_transfer_signed_dec(v1, v0);
			astc_helpers::bit_transfer_signed_dec(v3, v2);
			astc_helpers::bit_transfer_signed_dec(v5, v4);

			int s = v1 + v3 + v5;
			bool quant_used_blue_contraction = (s < 0);

			// Kind of a dumb algorithm, but it only tries 2-3 times in random testing.
			//const uint32_t MAX_TRIES = 10;
			const uint32_t MAX_TRIES = 5;

			uint32_t tries = 0;

			if (src_used_blue_contract != quant_used_blue_contraction)
			{
				int nudge_delta = quant_used_blue_contraction ? 1 : -1;

				uint32_t cur_c_rover = 2; // b first
								
				for (tries = 0; tries < MAX_TRIES; tries++)
				{
					for (uint32_t j = 0; j < 3; j++)
					{
						const uint32_t i = (cur_c_rover + j) % 3;

						// This will either nudge the delta, or fail because it's either at the [-32,31] limit or it can't go further in the desired delta direction due to quantization limits
						uint32_t new_ise_v = g_base_ofs_nudges[dst_ise_endpoint_range][(nudge_delta < 0) ? 1 : 0][pDst_endpoints[1 + i * 2]];

						if (new_ise_v != pDst_endpoints[1 + i * 2])
						{
							// It changed, so a successful nudge, but the base MSB should be preserved
							pDst_endpoints[1 + i * 2] = (uint8_t)new_ise_v;
							break;
						}
					}

					v0 = dst_dequant_tab[pDst_endpoints[0]], v1 = dst_dequant_tab[pDst_endpoints[1]];
					v2 = dst_dequant_tab[pDst_endpoints[2]], v3 = dst_dequant_tab[pDst_endpoints[3]];
					v4 = dst_dequant_tab[pDst_endpoints[4]], v5 = dst_dequant_tab[pDst_endpoints[5]];

					astc_helpers::bit_transfer_signed_dec(v1, v0);
					astc_helpers::bit_transfer_signed_dec(v3, v2);
					astc_helpers::bit_transfer_signed_dec(v5, v4);

					s = v1 + v3 + v5;
					quant_used_blue_contraction = (s < 0);

					if (src_used_blue_contract == quant_used_blue_contraction)
						break;

					++cur_c_rover;

				} // tries
			}

			if (tries < MAX_TRIES)
			{
				assert(astc_helpers::used_blue_contraction(cem, pDst_endpoints, dst_ise_endpoint_range) == astc_helpers::used_blue_contraction(cem, pSrc_endpoints, src_ise_endpoint_range));
			}
			else
			{
				// It failed to adjust, ultimately harmless as we have RGB(A) direct anyway (and at this likely very low quant level, it won't matter).
				// TODO: We could try more adjustments, but this seems extremely unlikely to be worth the trouble after random testing.

#if BASISU_ASTC_LDR_DEBUG_MSGS
				static bool s_msg_printed = false;
				if (!s_msg_printed)
					fmt_debug_printf("requantize_ise_endpoints: blue contraction enforcement failed\n");
#endif
			}

#ifdef _DEBUG
			{
				const auto& src_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(src_ise_endpoint_range).m_ISE_to_val;

				// ensure MSB's did not change
				for (uint32_t i = 0; i < num_endpoint_vals; i++)
				{
					int src_v = src_dequant_tab[pSrc_endpoints[i]];
					int dst_v = dst_dequant_tab[pDst_endpoints[i]];
					assert((src_v & 128) == (dst_v & 128));
				}
			}
#endif
		}
		else if ((cem == astc_helpers::CEM_LDR_RGB_DIRECT) || (cem == astc_helpers::CEM_LDR_RGBA_DIRECT))
		{
			const auto& dst_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_ISE_to_val;

			// See if the original colors were blue contracted
			uint32_t s0 = pDequantized_src_vals[0] + pDequantized_src_vals[2] + pDequantized_src_vals[4];
			uint32_t s1 = pDequantized_src_vals[1] + pDequantized_src_vals[3] + pDequantized_src_vals[5];

			const bool orig_used_blue_contract = s1 < s0;

			for (uint32_t i = 0; i < num_endpoint_vals; i++)
				pDst_endpoints[i] = dst_quant_tab[pDequantized_src_vals[i]];

			uint32_t dequant_s0 = dst_dequant_tab[pDst_endpoints[0]] + dst_dequant_tab[pDst_endpoints[2]] + dst_dequant_tab[pDst_endpoints[4]];
			uint32_t dequant_s1 = dst_dequant_tab[pDst_endpoints[1]] + dst_dequant_tab[pDst_endpoints[3]] + dst_dequant_tab[pDst_endpoints[5]];

			const bool quant_used_blue_contract = dequant_s1 < dequant_s0;

			if (orig_used_blue_contract != quant_used_blue_contract)
			{
				if (dequant_s0 == dequant_s1)
				{
					assert(orig_used_blue_contract);
					assert(!quant_used_blue_contract);

					// swapping won't work because sums are equal, so force dst to use blue contraction by nudgling a component
					// original s1<s0, but now requant_s1>=requant_s0

					if (dequant_s1)
					{
						// decrease s1
						for (uint32_t i = 0; i < 3; i++)
						{
							uint32_t new_ise_v = astc_helpers::apply_delta_to_bise_endpoint_val(dst_ise_endpoint_range, pDst_endpoints[1 + i * 2], -1);
							if (new_ise_v != pDst_endpoints[1 + i * 2])
							{
								pDst_endpoints[1 + i * 2] = (uint8_t)new_ise_v;
								break;
							}
						}
					}
					else
					{
						// both are 0, increase s0
						for (uint32_t i = 0; i < 3; i++)
						{
							uint32_t new_ise_val = astc_helpers::apply_delta_to_bise_endpoint_val(dst_ise_endpoint_range, pDst_endpoints[i * 2], 1);
							if (new_ise_val != pDst_endpoints[i * 2])
							{
								pDst_endpoints[i * 2] = (uint8_t)new_ise_val;
								break;
							}
						}
					}
				}
				else
				{
					std::swap(pDst_endpoints[0], pDst_endpoints[1]);
					std::swap(pDst_endpoints[2], pDst_endpoints[3]);
					std::swap(pDst_endpoints[4], pDst_endpoints[5]);

					if (cem == astc_helpers::CEM_LDR_RGBA_DIRECT)
						std::swap(pDst_endpoints[6], pDst_endpoints[7]);
				}
			}

			assert(astc_helpers::used_blue_contraction(cem, pDst_endpoints, dst_ise_endpoint_range) == astc_helpers::used_blue_contraction(cem, pSrc_endpoints, src_ise_endpoint_range));
		}
		else
		{
			for (uint32_t i = 0; i < num_endpoint_vals; i++)
				pDst_endpoints[i] = dst_quant_tab[pDequantized_src_vals[i]];

#ifdef _DEBUG
			{
				const auto& src_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(src_ise_endpoint_range).m_ISE_to_val;
				const auto& dst_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_ise_endpoint_range).m_ISE_to_val;

				// ensure MSB's did not change
				for (uint32_t i = 0; i < num_endpoint_vals; i++)
				{
					int src_v = src_dequant_tab[pSrc_endpoints[i]];
					int dst_v = dst_dequant_tab[pDst_endpoints[i]];
					assert((src_v & 128) == (dst_v & 128));
				}
			}
#endif
		}

		return true;
	}

	// First packs base+ofs to ise20 (always enforcing blue contraction), then quantizes down (preserving blue contraction whenever possible, which might possibly not be in extreme quantizations).
	// NOTE: Cannot use any floating point math for determinism across compilers.
	bool pack_base_offset(
		uint32_t cem_index, uint32_t dst_ise_endpoint_range, uint8_t* pPacked_endpoints,
		const color_rgba& l, const color_rgba& h,
		bool use_blue_contraction, bool auto_disable_blue_contraction_if_clamped,
		bool& blue_contraction_clamped_flag, bool& base_ofs_clamped_flag, bool& endpoints_swapped)
	{
		blue_contraction_clamped_flag = false;
		base_ofs_clamped_flag = false;
		endpoints_swapped = false;

		if ((cem_index != astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET) && (cem_index != astc_helpers::CEM_LDR_RGBA_BASE_PLUS_OFFSET))
		{
			assert(0);
			return false;
		}

		color_rgba pack_l(l), pack_h(h);

		if (use_blue_contraction)
		{
			color_rgba enc_l(blue_contract_enc(pack_l, blue_contraction_clamped_flag, pack_l.b));
			color_rgba enc_h(blue_contract_enc(pack_h, blue_contraction_clamped_flag, pack_h.b));

			if ((blue_contraction_clamped_flag) && (auto_disable_blue_contraction_if_clamped))
			{
				use_blue_contraction = false;
			}
			else
			{
				pack_h = enc_l;
				pack_l = enc_h;

				endpoints_swapped = true;
			}
		}

		int dr = 0, dg = 0, db = 0, da = 0;
		bool pack_uses_blue_contraction = false;
		int low_clamp = -32;

		// first 2 passes try with swapping by asymmetric clamping, then next 2 try with symmetric clamping, should always succeed
		for (uint32_t pass = 0; pass < 4; pass++)
		{
			// Take previous CEM's values and try to encode to base+offset as best we can, it may clamp
			int orig_dr = pack_h.r - pack_l.r, orig_dg = pack_h.g - pack_l.g, orig_db = pack_h.b - pack_l.b, orig_da = pack_h.a - pack_l.a;

			base_ofs_clamped_flag = false;

			dr = basisu::clamp<int>(orig_dr, low_clamp, 31);
			if (dr != orig_dr) base_ofs_clamped_flag = true;

			dg = basisu::clamp<int>(orig_dg, low_clamp, 31);
			if (dg != orig_dg) base_ofs_clamped_flag = true;

			db = basisu::clamp<int>(orig_db, low_clamp, 31);
			if (db != orig_db) base_ofs_clamped_flag = true;

			da = basisu::clamp<int>(orig_da, low_clamp, 31);
			if (da != orig_da) base_ofs_clamped_flag = true;

			int s = dr + dg + db;

			pack_uses_blue_contraction = s < 0;

			if (pack_uses_blue_contraction == use_blue_contraction)
				break;

			if (s == 0)
			{
				assert(!pack_uses_blue_contraction);
				assert(use_blue_contraction);

				// !pack_uses_blue_contraction here, sum=0, so force sum negative
				if (db > -32)
					db--;
				else if (dr > -32)
					dr--;
				else if (dg > -32)
					dg--;
				else
				{
					// they can't be all -32 (or negative), otherwise sum couldn't be 0
					assert(0);
				}

				assert((dr + dg + db) < 0);

				pack_uses_blue_contraction = true;

				break;
			}

			if (pass == 3)
			{
				// theoretically unreachable
				assert(0);
				break;
			}

			if (pass == 1)
			{
				// Try 2 more swap passes, but enforce a symmetric clamp range - this *should* work.
				low_clamp = -31;
			}

			std::swap(pack_l, pack_h);
			endpoints_swapped = !endpoints_swapped;

		} // pass

		int v0 = pack_l.r, v2 = pack_l.g, v4 = pack_l.b;
		int v1 = dr, v3 = dg, v5 = db;

		// lossless at 8-bits
		astc_helpers::bit_transfer_signed_enc(v1, v0);
		astc_helpers::bit_transfer_signed_enc(v3, v2);
		astc_helpers::bit_transfer_signed_enc(v5, v4);

		int v6 = 0, v7 = 0;
		if (astc_helpers::does_cem_have_alpha(cem_index))
		{
			v6 = pack_l.a;
			v7 = da;

			astc_helpers::bit_transfer_signed_enc(v7, v6);
		}

		uint8_t new_endpoints8[astc_helpers::MAX_CEM_ENDPOINT_VALS];

		new_endpoints8[0] = (uint8_t)v0;
		new_endpoints8[1] = (uint8_t)v1;

		new_endpoints8[2] = (uint8_t)v2;
		new_endpoints8[3] = (uint8_t)v3;

		new_endpoints8[4] = (uint8_t)v4;
		new_endpoints8[5] = (uint8_t)v5;

		if (astc_helpers::does_cem_have_alpha(cem_index))
		{
			new_endpoints8[6] = (uint8_t)v6;
			new_endpoints8[7] = (uint8_t)v7;
		}

		// This should always succeed.
		assert(astc_helpers::used_blue_contraction(cem_index, new_endpoints8, astc_helpers::BISE_256_LEVELS) == use_blue_contraction);

		// requant predicted 256 level endpoints to current endpoint quant level, this will nearly always (if not always) succeed
		bool status = requantize_ise_endpoints(
			cem_index, astc_helpers::BISE_256_LEVELS, new_endpoints8,
			dst_ise_endpoint_range, pPacked_endpoints);

		// can't assert because requant to a very low quant level could have failed to preserve blue contraction (in practice, super rare, perhaps impossible - still determining)
		//assert(astc_helpers::used_blue_contraction(cem_index, pPredicted_endpoints, cur_blk.m_endpoint_ise_range) == pack_uses_blue_contraction);

		return status;
	}

	// converts a previous block's endpoints, using any supported LDR CEM/endpoint quant level, into a new CEM/endpoint quant level
	// used for prediction or *potentially* coding purposes
	// will return num_dst_endpoint_vals residuals in cur_blk's endpoint level quant
	// NOTE: Cannot use any floating point math for determinism across compilers.
	// IMPORTANT: BE VERY CAREFUL MODIFYING THIS FUNCTION. It's part of the XUASTC LDR specification and must be deterministic and correct vs. the spec.
	bool convert_endpoints_across_cems(
		uint32_t prev_cem, uint32_t prev_endpoint_ise_range, const uint8_t* pPrev_endpoints,
		uint32_t dst_cem, uint32_t dst_endpoint_ise_range, uint8_t* pDst_endpoints,
		bool always_repack,
		bool use_blue_contraction, bool auto_disable_blue_contraction_if_clamped,
		bool& blue_contraction_clamped_flag, bool& base_ofs_clamped_flag)
	{
		blue_contraction_clamped_flag = false;
		base_ofs_clamped_flag = false;

		const uint32_t num_dst_endpoint_vals = astc_helpers::get_num_cem_values(dst_cem);

		const auto& dst_quant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_endpoint_ise_range).m_val_to_ise;
		const auto& dst_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(dst_endpoint_ise_range).m_ISE_to_val;

		if ((prev_cem == dst_cem) && (!always_repack))
		{
			// CEM's are precisely equal
			// Requantize prev block's endpoints into the current block's quant levels, and we're done
			return requantize_ise_endpoints(
				prev_cem, prev_endpoint_ise_range, pPrev_endpoints,
				dst_endpoint_ise_range, pDst_endpoints);
		}

		// CEM's cannot be precisely equal now, compute base CEM's (removing alpha from consideration)
		if (!always_repack)
		{
			// this path preserves the original's blue contraction status
			const uint32_t prev_base_cem = astc_helpers::get_base_cem_without_alpha(prev_cem);
			const uint32_t dst_base_cem = astc_helpers::get_base_cem_without_alpha(dst_cem);

			// prev cem has alpha, cur cem doesn't, but otherwise modes identical, so it's being stripped
			if ((prev_base_cem == dst_base_cem) && (!astc_helpers::does_cem_have_alpha(dst_cem)))
			{
				assert(astc_helpers::does_cem_have_alpha(prev_cem));
				assert(astc_helpers::get_num_cem_values(prev_base_cem) == num_dst_endpoint_vals);

				// Requantize prev block's endpoints into the current block's quant levels, but ignore the alpha values (which are always the last 2 entries)
				return requantize_ise_endpoints(
					prev_base_cem, prev_endpoint_ise_range, pPrev_endpoints,
					dst_endpoint_ise_range, pDst_endpoints);
			}

			// if prev cem doesn't have alpha, but the current cem does, but otherwise modes are identical, so add sane alpha (both 255) and hope for best in the prediction
			if ((prev_base_cem == dst_base_cem) && (astc_helpers::does_cem_have_alpha(dst_cem)))
			{
				assert(!astc_helpers::does_cem_have_alpha(prev_base_cem));

				// requant previous endpoints to current endpoint quant level
				bool status = requantize_ise_endpoints(
					prev_base_cem, prev_endpoint_ise_range, pPrev_endpoints,
					dst_endpoint_ise_range, pDst_endpoints);

				if (!status)
					return false;

				// just plug in 255 to both alphas
				const int ise_a_val = dst_quant_tab[255];

				switch (dst_cem)
				{
				case astc_helpers::CEM_LDR_LUM_ALPHA_DIRECT:
				{
					assert(num_dst_endpoint_vals == 4);
					pDst_endpoints[2] = (uint8_t)ise_a_val;
					pDst_endpoints[3] = (uint8_t)ise_a_val;
					break;
				}
				case astc_helpers::CEM_LDR_RGBA_DIRECT:
				{
					assert(num_dst_endpoint_vals == 8);
					pDst_endpoints[6] = (uint8_t)ise_a_val;
					pDst_endpoints[7] = (uint8_t)ise_a_val;
					break;
				}
				case astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A:
				{
					assert(num_dst_endpoint_vals == 6);
					pDst_endpoints[4] = (uint8_t)ise_a_val;
					pDst_endpoints[5] = (uint8_t)ise_a_val;
					break;
				}
				case astc_helpers::CEM_LDR_RGBA_BASE_PLUS_OFFSET:
				{
					assert(num_dst_endpoint_vals == 8);

					// alphas should decode to 255, 255
					pDst_endpoints[6] = (uint8_t)ise_a_val;		// base
					pDst_endpoints[7] = (uint8_t)dst_quant_tab[128];  // offset, top bit should be preserved
					break;
				}
				default:
					assert(0);
					break;
				}
												
				return true;
			}

		} // !always_repack

		// Here the CEM's are not even in the same class.
		// Do something reasonable to convert to the current block's CEM encoding and hope the residual distribution is reasonable.

		// fully decode the endpoints, undoing any quant, blue contraction or bit transfers
		color_rgba prev_l, prev_h;
		decode_endpoints(prev_cem, pPrev_endpoints, prev_endpoint_ise_range, prev_l, prev_h);

		uint8_t new_endpoints8[astc_helpers::MAX_CEM_ENDPOINT_VALS] = { 0 };

		// now pack the endpoints to the desired CEM
		switch (dst_cem)
		{
		case astc_helpers::CEM_LDR_LUM_DIRECT:
		case astc_helpers::CEM_LDR_LUM_ALPHA_DIRECT:
		{
			// Take previous endpoints and convert to luma/alpha low/high.
			new_endpoints8[0] = (prev_l.r + prev_l.g + prev_l.b + 1) / 3;
			new_endpoints8[1] = (prev_h.r + prev_h.g + prev_h.b + 1) / 3;

			if (dst_cem == astc_helpers::CEM_LDR_LUM_ALPHA_DIRECT)
			{
				new_endpoints8[2] = prev_l.a;
				new_endpoints8[3] = prev_h.a;
			}

			// ensure L<H, so predicting against other luma blocks is more successful (but less successful vs. blue contraction blocks)
			if ((prev_cem != astc_helpers::CEM_LDR_LUM_DIRECT) && (prev_cem != astc_helpers::CEM_LDR_LUM_ALPHA_DIRECT))
			{
				if (new_endpoints8[0] > new_endpoints8[1])
				{
					std::swap(new_endpoints8[0], new_endpoints8[1]);
					std::swap(new_endpoints8[2], new_endpoints8[3]);
				}
			}

			// requant predicted 256 level endpoints to current endpoint quant level
			return requantize_ise_endpoints(dst_cem, astc_helpers::BISE_256_LEVELS, new_endpoints8, dst_endpoint_ise_range, pDst_endpoints);
		}

		case astc_helpers::CEM_LDR_RGB_DIRECT:
		case astc_helpers::CEM_LDR_RGBA_DIRECT:
		{
			// Take previous endpoints and convert to rgb(a) direct, explictly preserving previous ordering (to preserve the previous's endpoints usage of blue contraction, if it used it).
			new_endpoints8[0] = prev_l.r;
			new_endpoints8[1] = prev_h.r;

			new_endpoints8[2] = prev_l.g;
			new_endpoints8[3] = prev_h.g;

			new_endpoints8[4] = prev_l.b;
			new_endpoints8[5] = prev_h.b;

			if (dst_cem == astc_helpers::CEM_LDR_RGBA_DIRECT)
			{
				new_endpoints8[6] = prev_l.a;
				new_endpoints8[7] = prev_h.a;
			}

			if (use_blue_contraction)
			{
				color_rgba enc_l(blue_contract_enc(prev_l, blue_contraction_clamped_flag, dst_dequant_tab[dst_quant_tab[prev_l.b]]));
				color_rgba enc_h(blue_contract_enc(prev_h, blue_contraction_clamped_flag, dst_dequant_tab[dst_quant_tab[prev_h.b]]));

				if ((auto_disable_blue_contraction_if_clamped) && (blue_contraction_clamped_flag))
				{
					use_blue_contraction = false;
				}
				else
				{
					new_endpoints8[0] = enc_h.r;
					new_endpoints8[1] = enc_l.r;

					new_endpoints8[2] = enc_h.g;
					new_endpoints8[3] = enc_l.g;

					new_endpoints8[4] = enc_h.b;
					new_endpoints8[5] = enc_l.b;

					if (dst_cem == astc_helpers::CEM_LDR_RGBA_DIRECT)
					{
						new_endpoints8[6] = prev_h.a;
						new_endpoints8[7] = prev_l.a;
					}
				}
			}

			uint32_t s0 = new_endpoints8[0] + new_endpoints8[2] + new_endpoints8[4];
			uint32_t s1 = new_endpoints8[1] + new_endpoints8[3] + new_endpoints8[5];
			bool pack_used_blue_contraction = s1 < s0;

			if (pack_used_blue_contraction != use_blue_contraction)
			{
				if (s0 == s1)
				{
					assert(!pack_used_blue_contraction);

					// swapping won't work because sums are equal, so force dst to use blue contraction by nudgling a component
					// require s1<s0

					if (s1)
					{
						// decrease s1
						for (uint32_t i = 0; i < 3; i++)
						{
							uint32_t new_ise_v = astc_helpers::apply_delta_to_bise_endpoint_val(astc_helpers::BISE_256_LEVELS, new_endpoints8[1 + i * 2], -1);
							if (new_ise_v != new_endpoints8[1 + i * 2])
							{
								new_endpoints8[1 + i * 2] = (uint8_t)new_ise_v;
								break;
							}
						}
					}
					else
					{
						// both are 0, increase s0
						for (uint32_t i = 0; i < 3; i++)
						{
							uint32_t new_ise_val = astc_helpers::apply_delta_to_bise_endpoint_val(astc_helpers::BISE_256_LEVELS, new_endpoints8[i * 2], 1);
							if (new_ise_val != new_endpoints8[i * 2])
							{
								new_endpoints8[i * 2] = (uint8_t)new_ise_val;
								break;
							}
						}
					}
				}
				else
				{
					for (uint32_t i = 0; i < num_dst_endpoint_vals; i += 2)
						std::swap(new_endpoints8[i], new_endpoints8[i + 1]);
				}
			}

			assert(astc_helpers::used_blue_contraction(dst_cem, new_endpoints8, astc_helpers::BISE_256_LEVELS) == use_blue_contraction);

			// requant predicted 256 level endpoints to current endpoint quant level
			bool status = requantize_ise_endpoints(dst_cem, astc_helpers::BISE_256_LEVELS, new_endpoints8, dst_endpoint_ise_range, pDst_endpoints);

			// should always have succeeded with rgb(a) direct
			assert(astc_helpers::used_blue_contraction(dst_cem, pDst_endpoints, dst_endpoint_ise_range) == use_blue_contraction);

			if (!status)
				return false;

			break;
		}
		case astc_helpers::CEM_LDR_RGB_BASE_SCALE:
		case astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A:
		{
			color_rgba lc(prev_l), hc(prev_h);

			// Normalize the l/h colors for proper base+scale packing if the endpoints came from a non-base-scale CEM (unless the colors came from base_scale, in which case, leave them alone).
			if ((prev_cem != astc_helpers::CEM_LDR_RGB_BASE_SCALE) &&
				(prev_cem != astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A))
			{
				if ((lc.r + lc.g + lc.b) > (hc.r + hc.g + hc.b))
				{
					std::swap(lc, hc);
				}
			}

			new_endpoints8[0] = hc.r;
			new_endpoints8[1] = hc.g;
			new_endpoints8[2] = hc.b;

#if 0
			// TODO: remove FP here
			vec3F lf((float)lc.r, (float)lc.g, (float)lc.b);
			vec3F hf((float)hc.r, (float)hc.g, (float)hc.b);

			const float MAX_S = 255.0f / 256.0f;

			float scale = MAX_S;

			float d = lf.dot(hf);
			float nrm = hf.norm();
			if (nrm > 0.0f)
				scale = d / nrm;

			scale = basisu::clamp(scale, 0.0f, MAX_S);

			new_endpoints8[3] = (uint8_t)basisu::clamp<int>((int)std::round(scale * 256.0f), 0, 255); // explictly not 255.0f, but 256.0f, decoder divides scale by 256.0f
#endif

			{
				int id = (lc.r * hc.r) + (lc.g * hc.g) + (lc.b * hc.b);
				int inrm = (hc.r * hc.r) + (hc.g * hc.g) + (hc.b * hc.b);

				const int IMAX_S = (1024 * 255) / 256;
				
				int iscale = IMAX_S;
				if (inrm > 0)
					iscale = (id * 1024) / inrm;

				iscale = basisu::clamp<int>(iscale, 0, IMAX_S);

				iscale = (iscale + 2) >> 2;
				iscale = basisu::clamp<int>(iscale, 0, 255);

				//assert(basisu::iabs(new_endpoints8[3] - iscale) <= 1);
				new_endpoints8[3] = static_cast<uint8_t>(iscale);
			}

			if (dst_cem == astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A)
			{
				new_endpoints8[4] = lc.a;
				new_endpoints8[5] = hc.a;

				if ((prev_cem != astc_helpers::CEM_LDR_RGB_BASE_SCALE) &&
					(prev_cem != astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A))
				{
					// ensure val4 < val5 for proper lerping on single plane (correlated alpha)
					if (new_endpoints8[4] > new_endpoints8[5])
						std::swap(new_endpoints8[4], new_endpoints8[5]);
				}
			}

			// requant predicted 256 level endpoints to current endpoint quant level
			return requantize_ise_endpoints(dst_cem, astc_helpers::BISE_256_LEVELS, new_endpoints8, dst_endpoint_ise_range, pDst_endpoints);
		}
		case astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET:
		case astc_helpers::CEM_LDR_RGBA_BASE_PLUS_OFFSET:
		{
			bool endpoints_swapped = false;

			return pack_base_offset(dst_cem, dst_endpoint_ise_range, pDst_endpoints, prev_l, prev_h, use_blue_contraction, auto_disable_blue_contraction_if_clamped,
				blue_contraction_clamped_flag, base_ofs_clamped_flag, endpoints_swapped);
		}
		default:
		{
			assert(0);
			return false;
		}
		}

		return true;
	}

	// Assumes ise 20 (256 levels)
	void decode_endpoints_ise20(uint32_t cem_index, const uint8_t* pEndpoint_vals, color32& l, color32& h)
	{
		assert(astc_helpers::is_cem_ldr(cem_index));

		int ldr_endpoints[4][2];
		astc_helpers::decode_endpoint(cem_index, ldr_endpoints, pEndpoint_vals);

		for (uint32_t c = 0; c < 4; c++)
		{
			assert((ldr_endpoints[c][0] >= 0) && (ldr_endpoints[c][0] <= 255));
			assert((ldr_endpoints[c][1] >= 0) && (ldr_endpoints[c][1] <= 255));

			l[c] = (uint8_t)ldr_endpoints[c][0];
			h[c] = (uint8_t)ldr_endpoints[c][1];
		}
	}

	void decode_endpoints(uint32_t cem_index, const uint8_t* pEndpoint_vals, uint32_t endpoint_ise_index, color32& l, color32& h, float* pScale)
	{
		const uint32_t total_endpoint_vals = astc_helpers::get_num_cem_values(cem_index);

		const auto& endpoint_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(endpoint_ise_index).m_ISE_to_val;

		uint8_t dequantized_endpoints[astc_helpers::MAX_CEM_ENDPOINT_VALS];
		for (uint32_t i = 0; i < total_endpoint_vals; i++)
			dequantized_endpoints[i] = endpoint_dequant_tab[pEndpoint_vals[i]];

		decode_endpoints_ise20(cem_index, dequantized_endpoints, l, h);

		if ((pScale) && ((cem_index == astc_helpers::CEM_LDR_RGB_BASE_SCALE) || (cem_index == astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A)))
		{
			*pScale = (float)dequantized_endpoints[3] * (1.0f / 256.0f);
		}
	}

	// Assumes ise 20 (256 levels)
	void decode_endpoints_ise20(uint32_t cem_index, const uint8_t* pEndpoint_vals, color_rgba& l, color_rgba& h)
	{
		assert(astc_helpers::is_cem_ldr(cem_index));

		int ldr_endpoints[4][2];
		astc_helpers::decode_endpoint(cem_index, ldr_endpoints, pEndpoint_vals);

		for (uint32_t c = 0; c < 4; c++)
		{
			assert((ldr_endpoints[c][0] >= 0) && (ldr_endpoints[c][0] <= 255));
			assert((ldr_endpoints[c][1] >= 0) && (ldr_endpoints[c][1] <= 255));

			l[c] = (uint8_t)ldr_endpoints[c][0];
			h[c] = (uint8_t)ldr_endpoints[c][1];
		}
	}

	void decode_endpoints(uint32_t cem_index, const uint8_t* pEndpoint_vals, uint32_t endpoint_ise_index, color_rgba& l, color_rgba& h, float* pScale)
	{
		const uint32_t total_endpoint_vals = astc_helpers::get_num_cem_values(cem_index);

		const auto& endpoint_dequant_tab = astc_helpers::g_dequant_tables.get_endpoint_tab(endpoint_ise_index).m_ISE_to_val;

		uint8_t dequantized_endpoints[astc_helpers::MAX_CEM_ENDPOINT_VALS];
		for (uint32_t i = 0; i < total_endpoint_vals; i++)
			dequantized_endpoints[i] = endpoint_dequant_tab[pEndpoint_vals[i]];

		decode_endpoints_ise20(cem_index, dequantized_endpoints, l, h);

		if ((pScale) && ((cem_index == astc_helpers::CEM_LDR_RGB_BASE_SCALE) || (cem_index == astc_helpers::CEM_LDR_RGB_BASE_SCALE_PLUS_TWO_A)))
		{
			*pScale = (float)dequantized_endpoints[3] * (1.0f / 256.0f);
		}
	}

	// TODO: Duplicated in astc_hdr
	void compute_upsample_matrix(basisu::vector2D<float>& upsample_matrix, uint32_t block_width, uint32_t block_height, uint32_t grid_width, uint32_t grid_height)
	{
		assert((block_width >= 2) && (block_width <= astc_helpers::MAX_BLOCK_DIM));
		assert((block_height >= 2) && (block_height <= astc_helpers::MAX_BLOCK_DIM));
		assert((grid_width >= 2) && (grid_width <= block_width));
		assert((grid_height >= 2) && (grid_height <= block_height));

		const uint32_t num_block_samples = block_width * block_height;
		const uint32_t num_grid_samples = grid_width * grid_height;

		astc_helpers::weighted_sample samples[astc_helpers::MAX_BLOCK_DIM * astc_helpers::MAX_BLOCK_DIM];
		basisu::clear_obj(samples);

		astc_helpers::compute_upsample_weights(block_width, block_height, grid_width, grid_height, samples);

		// Compute upsample matrix: output num_block_samples (rows), input num_grid_samples (cols)
		upsample_matrix.resize_rows_cols(num_block_samples, num_grid_samples);

		basisu::vector<float> weights(num_grid_samples);

		// compute which source sample(s) contribute to it.
		for (uint32_t d = 0; d < num_block_samples; d++)
		{
			const astc_helpers::weighted_sample& ws = samples[d];

			weights.set_all(0.0f);

			for (uint32_t y = 0; y < 2; y++)
			{
				for (uint32_t x = 0; x < 2; x++)
				{
					float w = ws.m_weights[y][x] * (1.0f / 16.0f);
					if (!w)
						continue;

					assert((ws.m_src_x + x) < grid_width);
					assert((ws.m_src_y + y) < grid_height);

					assert(weights[(ws.m_src_x + x) + (ws.m_src_y + y) * grid_width] == 0.0f);
					weights[(ws.m_src_x + x) + (ws.m_src_y + y) * grid_width] = w;
				} //  x
			} // y

			for (uint32_t i = 0; i < num_grid_samples; i++)
				upsample_matrix.at_row_col(d, i) = weights[i];

		} // d
	}

	// TODO: Only needed by ASTC LDR encoder
	void compute_adjoint_downsample_matrix(basisu::vector<float>& downsample_matrix, uint32_t block_width, uint32_t block_height, uint32_t grid_width, uint32_t grid_height)
	{
		assert((block_width >= 2) && (block_width <= astc_helpers::MAX_BLOCK_DIM));
		assert((block_height >= 2) && (block_height <= astc_helpers::MAX_BLOCK_DIM));
		assert((grid_width >= 2) && (grid_width <= block_width));
		assert((grid_height >= 2) && (grid_height <= block_height));

		const uint32_t num_block_samples = block_width * block_height;
		const uint32_t num_grid_samples = grid_width * grid_height;

		// Compute upsample matrix: output num_block_samples (rows), input num_grid_samples (cols)
		basisu::vector2D<float> upsample_matrix;
		compute_upsample_matrix(upsample_matrix, block_width, block_height, grid_width, grid_height);

		basisu::vector<float> Dinv(num_grid_samples);
		for (uint32_t j = 0; j < num_grid_samples; j++)
		{
			float sum = 0.0f;

			for (uint32_t i = 0; i < num_block_samples; i++)
				sum += upsample_matrix.at_row_col(i, j);

			if (sum > 0.0f)
				Dinv[j] = 1.0f / sum;
		}

		// Create downsample matrix: num_grid_samples rows, num_block_samples cols
		downsample_matrix.resize(num_grid_samples * num_block_samples);
		downsample_matrix.set_all(0.0f);

		for (uint32_t j = 0; j < num_grid_samples; ++j)
			for (uint32_t i = 0; i < num_block_samples; ++i)
				downsample_matrix[j * num_block_samples + i] = Dinv[j] * upsample_matrix.at_row_col(i, j);
	}
	
	void init_astc_block_grid_data_hash()
	{
		// 572 valid block dim+grid dim configs
		g_astc_block_grid_data_hash.m_grid_data.reserve(600);
				
		for (uint32_t block_size_index = 0; block_size_index < astc_helpers::NUM_ASTC_BLOCK_SIZES; block_size_index++)
		{
			const uint32_t block_w = astc_helpers::g_astc_block_sizes[block_size_index][0];
			const uint32_t block_h = astc_helpers::g_astc_block_sizes[block_size_index][1];
			
			assert(astc_helpers::is_valid_block_size(block_w, block_h));

			const int bw = block_w, bh = block_h;
			const int num_texels = bw * bh;
						
			for (uint32_t grid_h = 2; grid_h <= block_h; grid_h++)
			{
				for (uint32_t grid_w = 2; grid_w <= block_w; grid_w++)
				{
					const int gw = grid_w, gh = grid_h;
					const int num_weights = gw * gh;

					if (num_weights > (int)astc_helpers::MAX_GRID_WEIGHTS)
						continue;

					astc_block_grid_data grid_data;
					
					basisu::vector2D<float>& upsample_matrix = grid_data.m_upsample_matrix;

					compute_upsample_matrix(upsample_matrix, bw, bh, gw, gh);

					float accum = 0.0f;
					for (int t = 0; t < num_texels; ++t)
					{
						float row_sum_sq = 0.0f;
						const float* row = &(upsample_matrix.get_ptr())[t * num_weights];

						for (int i = 0; i < num_weights; ++i)
						{
							float w = row[i];
							row_sum_sq += w * w;
						}

						accum += row_sum_sq;
					}
										
					// estimate of MSE weight quantization reduction due to bilinear weight grid upsampling
					// TODO: Gamma is used during encoding now, not transcoding.
					const float weight_gamma = accum / (float)num_texels;

					grid_data.m_weight_gamma = weight_gamma;
					
					basisu::vector<float>& downsample_matrix = grid_data.m_downsample_matrix;
					compute_adjoint_downsample_matrix(downsample_matrix, bw, bh, gw, gh);

					g_astc_block_grid_data_hash.insert(bw, bh, gw, gh, grid_data);
					
				} // grid_w
			} // grid_h

		} // block_size_index
	}

#include "basisu_idct.h"

#if 0
	typedef void (*idct_1d_func_ptr)(const float* src, int src_stride, float* dst, int dst_stride);

	const idct_1d_func_ptr g_idct_1d_func_ptrs[11] =
	{
		idct_1d_2,
		idct_1d_3,
		idct_1d_4,

		idct_1d_5,
		idct_1d_6,
		idct_1d_7,
		idct_1d_8,

		idct_1d_9,
		idct_1d_10,
		idct_1d_11,
		idct_1d_12,
	};
#endif

	static inline void idct_2d(const float* pSrc, float* pDst, uint32_t num_rows, uint32_t num_cols)
	{
		assert((num_rows >= 2) && (num_rows <= 12));
		assert((num_cols >= 2) && (num_cols <= 12));

		float temp[12 * 12];

		// IDCT cols from src to temp

#if 0
		// This works but uses slow WASM indirect calls
				
		const idct_1d_func_ptr pCol_xform = g_idct_1d_func_ptrs[num_rows - 2];
		for (uint32_t c = 0; c < num_cols; c++)
		{
			(*pCol_xform)(pSrc + c, num_cols, temp + c, num_cols);
		}
#else
		switch (num_rows)
		{
		case 2:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_2(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 3:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_3(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 4:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_4(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 5:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_5(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 6:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_6(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 7:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_7(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 8:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_8(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 9:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_9(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 10:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_10(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 11:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_11(pSrc + c, num_cols, temp + c, num_cols);
			break;
		case 12:
		default:
			for (uint32_t c = 0; c < num_cols; c++)
				idct_1d_12(pSrc + c, num_cols, temp + c, num_cols);
			break;
		}
#endif

		// IDCT rows from temp to dst

#if 0
		// This works but uses slow WASM indirect calls
		const idct_1d_func_ptr pRow_xform = g_idct_1d_func_ptrs[num_cols - 2];

		float* pTemp_row = temp;
		float* pDst_row = pDst;
		for (uint32_t r = 0; r < num_rows; r++)
		{
			(*pRow_xform)(pTemp_row, 1, pDst_row, 1);
			pTemp_row += num_cols;
			pDst_row += num_cols;
		}
#else
		float* pTemp_row = temp;
		float* pDst_row = pDst;
		switch (num_cols)
		{
		case 2:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_2(pTemp_row, 1, pDst_row, 1);
			break;
		case 3:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_3(pTemp_row, 1, pDst_row, 1);
			break;
		case 4:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_4(pTemp_row, 1, pDst_row, 1);
			break;
		case 5:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_5(pTemp_row, 1, pDst_row, 1);
			break;
		case 6:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_6(pTemp_row, 1, pDst_row, 1);
			break;
		case 7:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_7(pTemp_row, 1, pDst_row, 1);
			break;
		case 8:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_8(pTemp_row, 1, pDst_row, 1);
			break;
		case 9:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_9(pTemp_row, 1, pDst_row, 1);
			break;
		case 10:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_10(pTemp_row, 1, pDst_row, 1);
			break;
		case 11:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_11(pTemp_row, 1, pDst_row, 1);
			break;
		case 12:
		default:
			for (uint32_t r = 0; r < num_rows; r++, pTemp_row += num_cols, pDst_row += num_cols)
				idct_1d_12(pTemp_row, 1, pDst_row, 1);
			break;
		}
#endif
	}
				
	bool dct2f::init(uint32_t rows, uint32_t cols)
	{
		if ((rows < 2u) || (rows > cMaxSize) ||
			(cols < 2u) || (cols > cMaxSize))
		{
			assert(0);
			return false;
		}

		m_rows = rows;
		m_cols = cols;

		m_c_col.assign(m_rows * m_rows, 0.0f);
		m_c_row.assign(m_cols * m_cols, 0.0f);
		m_a_col.assign(m_rows, 0.0f);
		m_a_row.assign(m_cols, 0.0f);

		const float pi = 3.14159265358979323846f;

		// alpha scaling
		const float inv_m = 1.0f / static_cast<float>(m_rows);
		m_a_col[0] = sqrtf(inv_m);
		for (uint32_t u = 1; u < m_rows; ++u)
			m_a_col[u] = sqrtf(2.0f * inv_m);

		const float inv_n = 1.0f / static_cast<float>(m_cols);
		m_a_row[0] = sqrtf(inv_n);
		for (uint32_t v = 1; v < m_cols; ++v)
			m_a_row[v] = sqrtf(2.0f * inv_n);

		// cos tables
		for (uint32_t u = 0; u < m_rows; ++u)
		{
			for (uint32_t x = 0; x < m_rows; ++x)
			{
				float angle = (pi * static_cast<float>((2 * x + 1) * u)) / (2.0f * static_cast<float>(m_rows));
				m_c_col[u * m_rows + x] = cosf(angle);
			}
		}

		for (uint32_t v = 0; v < m_cols; ++v)
		{
			for (uint32_t y = 0; y < m_cols; ++y)
			{
				float angle = (pi * static_cast<float>((2 * y + 1) * v)) / (2.0f * static_cast<float>(m_cols));
				m_c_row[v * m_cols + y] = cosf(angle);
			}
		}

		return true;
	}
				
	void dct2f::forward(const float* pSrc, float* pDst, fvec& work) const
	{
		forward(pSrc, m_cols, pDst, m_cols, work);
	}

	void dct2f::inverse(const float* pSrc, float* pDst, fvec& work) const
	{
		inverse(pSrc, m_cols, pDst, m_cols, work);
	}

	void dct2f::inverse_check(const float* pSrc, float* pDst, fvec& work) const
	{
		inverse_check(pSrc, m_cols, pDst, m_cols, work);
	}

	void dct2f::forward(const float* pSrc, uint32_t src_stride,
		float* pDst, uint32_t dst_stride, fvec& work) const
	{
		assert(m_rows && m_cols);
		work.resize(m_rows * m_cols);

		const uint32_t m = m_rows, n = m_cols;

		float* pWork = &work[0];

		// horizontal
		for (uint32_t x = 0; x < m; ++x)
		{
			const float* pRowIn = pSrc + x * src_stride;
			float* pRowT = pWork + x * n;
			for (uint32_t v = 0; v < n; ++v)
			{
				const float* pCv = &m_c_row[v * n];
				float s = 0.0f;
				for (uint32_t y = 0; y < n; ++y)
				{
					s += pRowIn[y] * pCv[y];
				}
				pRowT[v] = s * m_a_row[v];
			}
		}

		// vertical
		for (uint32_t v = 0; v < n; ++v)
		{
			for (uint32_t u = 0; u < m; ++u)
			{
				const float* pCu = &m_c_col[u * m];
				float s = 0.0f;
				for (uint32_t x = 0; x < m; ++x)
				{
					s += pWork[x * n + v] * pCu[x];
				}
				pDst[u * dst_stride + v] = s * m_a_col[u];
			}
		}
	}

	void dct2f::forward(const float* pSrc, uint32_t src_stride,
		float* pDst, uint32_t dst_stride, float *pWork) const
	{
		assert(m_rows && m_cols);
		
		const uint32_t m = m_rows, n = m_cols;
				
		// horizontal
		for (uint32_t x = 0; x < m; ++x)
		{
			const float* pRowIn = pSrc + x * src_stride;
			float* pRowT = pWork + x * n;
			for (uint32_t v = 0; v < n; ++v)
			{
				const float* pCv = &m_c_row[v * n];
				float s = 0.0f;
				for (uint32_t y = 0; y < n; ++y)
				{
					s += pRowIn[y] * pCv[y];
				}
				pRowT[v] = s * m_a_row[v];
			}
		}

		// vertical
		for (uint32_t v = 0; v < n; ++v)
		{
			for (uint32_t u = 0; u < m; ++u)
			{
				const float* pCu = &m_c_col[u * m];
				float s = 0.0f;
				for (uint32_t x = 0; x < m; ++x)
				{
					s += pWork[x * n + v] * pCu[x];
				}
				pDst[u * dst_stride + v] = s * m_a_col[u];
			}
		}
	}

	// src_stride/dst_stride must be m_cols
	void dct2f::inverse(const float* pSrc, uint32_t src_stride,
		float* pDst, uint32_t dst_stride, fvec& work) const
	{
		BASISU_NOTE_UNUSED(src_stride);
		BASISU_NOTE_UNUSED(dst_stride);

#if 0
		assert(m_rows && m_cols);
		work.resize(m_rows * m_cols);

		const uint32_t m = m_rows, n = m_cols;
		float* pWork = &work[0];

		// vertical
		for (uint32_t v = 0; v < n; ++v) // cols
		{
			float sums[cMaxSize] = { 0 };

			for (uint32_t u = 0; u < m; ++u) // rows
			{
				if (((const uint32_t*)pSrc)[u * src_stride + v] == 0)
					continue;

				float yU = pSrc[u * src_stride + v]; // most coeffs will be 0
				//if (yU == 0.0f)
				//	continue;

				yU *= m_a_col[u];

				for (uint32_t x = 0; x < m; ++x)
				{
					const float cU = m_c_col[u * m + x];
					sums[x] += yU * cU;
				} // x

			} // u

			for (uint32_t x = 0; x < m; ++x)
				pWork[x * n + v] = sums[x];

		} // v

		// horizontal
		for (uint32_t x = 0; x < m; ++x)  // rows 
		{
			const float* pRowT = pWork + x * n;
			float* pRowOut = pDst + x * dst_stride;

			for (uint32_t y = 0; y < n; ++y) // cols
			{
				float s = 0.0f;
				for (uint32_t v = 0; v < n; ++v)  // cols
				{
					const float cV = m_c_row[v * n + y];
					s += (pRowT[v] * m_a_row[v]) * cV;
				}
				pRowOut[y] = s;
			}
		}
#else
		BASISU_NOTE_UNUSED(work);
		assert(src_stride == m_cols);
		assert(dst_stride == m_cols);
		idct_2d(pSrc, pDst, m_rows, m_cols);
#endif
	}

	void dct2f::inverse_check(const float* pSrc, uint32_t src_stride,
		float* pDst, uint32_t dst_stride, fvec& work) const
	{
		assert(m_rows && m_cols);
		work.resize(m_rows * m_cols);

		const uint32_t m = m_rows, n = m_cols;
		float* pWork = &work[0];

		// vertical
		for (uint32_t v = 0; v < n; ++v)
		{
			for (uint32_t x = 0; x < m; ++x)
			{
				float s = 0.0f;
				for (uint32_t u = 0; u < m; ++u)
				{
					const float yU = pSrc[u * src_stride + v];
					const float cU = m_c_col[u * m + x];
					s += (yU * m_a_col[u]) * cU;
				}
				pWork[x * n + v] = s;
			}
		}

		// horizontal
		for (uint32_t x = 0; x < m; ++x)  // rows 
		{
			const float* pRowT = pWork + x * n;
			float* pRowOut = pDst + x * dst_stride;

			for (uint32_t y = 0; y < n; ++y) // cols
			{
				float s = 0.0f;
				for (uint32_t v = 0; v < n; ++v)  // cols
				{
					const float cV = m_c_row[v * n + y];
					s += (pRowT[v] * m_a_row[v]) * cV;
				}
				pRowOut[y] = s;
			}
		}
	}
	
	static int* generate_zigzag_order(int width, int height)
	{
		assert((width > 0) && (height > 0));

		const int total = width * height;
		int* pOrder = (int*)malloc(total * sizeof(int));
		if (!pOrder)
			return nullptr;

		int idx = 0;
		for (int s = 0; s < (width + height - 1); ++s)
		{
			// Start x at max(0, s - height + 1), end at min(s, width - 1)
			const int x_start = (s < height) ? 0 : (s - height + 1);
			const int x_end = (s < width) ? s : (width - 1);

			// Diagonal size
			const int diag_size = x_end - x_start + 1;
			int* pDiag = (int*)malloc(diag_size * sizeof(int));
			if (!pDiag)
			{
				free(pOrder);
				return nullptr;
			}

			int j = 0;
			for (int x = x_start; x <= x_end; ++x)
			{
				int y = s - x;
				assert(j < diag_size);
				pDiag[j++] = x + y * width;
			}

			// Reverse if s is odd (alternate direction)
			if ((s & 1) == 1)
			{
				for (int k = diag_size - 1; k >= 0; --k) 
				{
					assert(idx < total);
					pOrder[idx++] = pDiag[k];
				}
			}
			else
			{
				for (int k = 0; k < diag_size; ++k) 
				{
					assert(idx < total);
					pOrder[idx++] = pDiag[k];
				}
			}

			free(pDiag);
		}

		return pOrder;
	}

	static const int g_baseline_jpeg_y[8][8] = 
	{
		// DC element modified so bilinear fetches near (0,0) grab a smaller quant table value, protecting most important LF coefficients
		{  4, 11, 10, 16, 24, 40, 51, 61 },	
		{ 12, 12, 14, 19, 26, 58, 60, 55 },
		{ 14, 13, 16, 24, 40, 57, 69, 56 },
		{ 14, 17, 22, 29, 51, 87, 80, 62 },
		{ 18, 22, 37, 56, 68,109,103, 77 },
		{ 24, 35, 55, 64, 81,104,113, 92 },
		{ 49, 64, 78, 87,103,121,120,101 },
		{ 72, 92, 95, 98,112,100,103, 99 }
	};

	// centers at (0,0)
	static inline float sample_jpeg_quant(const int Q8[8][8], float i, float j)
	{
		i = basisu::minimum(basisu::maximum(i, 0.0f), 7.0f);
		j = basisu::minimum(basisu::maximum(j, 0.0f), 7.0f);
		int i0 = (int)floorf(i), j0 = (int)floorf(j);
		int i1 = basisu::minimum(i0 + 1, 7), j1 = basisu::minimum(j0 + 1, 7);
		float ti = i - i0, tj = j - j0;
		float a = (1 - ti) * Q8[j0][i0] + ti * Q8[j0][i1];
		float b = (1 - ti) * Q8[j1][i0] + ti * Q8[j1][i1];
		return (1 - tj) * a + tj * b;
	}
				
	void grid_weight_dct::init(uint32_t block_width, uint32_t block_height)
	{
		m_block_width = block_width;
		m_block_height = block_height;

		for (uint32_t grid_height = 2; grid_height <= block_height; grid_height++)
		{
			for (uint32_t grid_width = 2; grid_width <= block_width; grid_width++)
			{
				// Check if this is a valid ASTC weight grid dimension
				if ((grid_width * grid_height) > astc_helpers::MAX_GRID_WEIGHTS)
					continue;

				auto ins_res = m_grid_dim_key_vals.insert(grid_dim_key(grid_width, grid_height), grid_dim_value());
				auto& val = ins_res.first->second;

				val.m_dct.init(grid_height, grid_width);

				int* pZigZag = generate_zigzag_order(grid_width, grid_height);

				basisu::int_vec v(grid_width * grid_height);
				memcpy(v.data(), pZigZag, sizeof(int) * grid_width * grid_height);

				free(pZigZag);

				val.m_zigzag.swap(v);

			} // w
		} // h
	}
				
	// This can use FP as it only impacts the final decoded weights (not future blocks)
	bool grid_weight_dct::decode_block_weights(
		float q, uint32_t plane_index, // plane of weights to decode and IDCT from stream
		astc_helpers::log_astc_block& log_blk, // must be initialized except for the plane weights which are decoded
		basist::bitwise_decoder* pDec,
		block_stats* pS,
		fvec& dct_work,
		const dct_syms* pSyms) const
	{
		assert(!log_blk.m_solid_color_flag_ldr);

		const uint32_t grid_width = log_blk.m_grid_width, grid_height = log_blk.m_grid_height;
		const uint32_t total_grid_samples = grid_width * grid_height;
		const uint32_t num_planes = log_blk.m_dual_plane ? 2 : 1;

		//const auto& dequant_tab = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_ISE_to_val;
		const auto& quant_tab = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_val_to_ise;

		auto grid_dim_vals_iter = m_grid_dim_key_vals.find(grid_dim_key(grid_width, grid_height));
		
		if (grid_dim_vals_iter == m_grid_dim_key_vals.end())
		{
			// Invalid grid dimension for this block size
			assert(0);
			return false;
		}

		auto& grid_dim_vals = grid_dim_vals_iter->second;

		const float span_len = get_max_span_len(log_blk, plane_index);

		const float level_scale = compute_level_scale(q, span_len, grid_width, grid_height, log_blk.m_weight_ise_range);
				
		float scaled_weight_coding_scale = SCALED_WEIGHT_BASE_CODING_SCALE;
		if (log_blk.m_weight_ise_range <= astc_helpers::BISE_8_LEVELS)
			scaled_weight_coding_scale = 1.0f / 8.0f;

		float mean_weight = 0;

		if (pDec)
			mean_weight = (float)pDec->decode_truncated_binary((uint32_t)(64.0f * scaled_weight_coding_scale) + 1) / (float)scaled_weight_coding_scale;
		else if (pSyms)
			mean_weight = (float)pSyms->m_dc_sym / (float)scaled_weight_coding_scale;
		else
		{
			assert(0);
			return false;
		}

		if (pS)
		{
			pS->m_mean_weight = mean_weight;
			pS->m_total_coded_acs = 0;
			pS->m_max_ac_coeff = 0;
		}

		float dct_weights[astc_helpers::MAX_BLOCK_PIXELS];

		const auto& zigzag = grid_dim_vals.m_zigzag;

		basisu::clear_obj(dct_weights);

		sample_quant_table_state quant_state;
		quant_state.init(q, m_block_width, m_block_height, level_scale);
				
		if (pDec)
		{
			for (uint32_t zig_idx = 1; zig_idx < total_grid_samples; zig_idx++)
			{
				uint32_t run_len = pDec->decode_rice(m_zero_run);

				if ((run_len + zig_idx) > total_grid_samples)
					return false;

				zig_idx += run_len;

				if (zig_idx >= total_grid_samples)
					break;

				int sign = pDec->get_bits(1);

				int coeff = pDec->decode_rice(m_coeff);

				if (sign)
					coeff = -coeff;

				int dct_idx = zigzag[zig_idx];

				const uint32_t y = (uint32_t)dct_idx / grid_width;
				const uint32_t x = (uint32_t)dct_idx % grid_width;
				
				//const int quant = dct_quant_tab[dct_idx];
				const int quant = sample_quant_table(quant_state, x, y);
				//assert(quant == sample_quant_table(quant_state, x, y));

				dct_weights[dct_idx] = dequant_deadzone(coeff, quant, DEADZONE_ALPHA, x, y);

				if (pS)
				{
					++pS->m_total_coded_acs;
					pS->m_max_ac_coeff = basisu::maximum<uint32_t>(pS->m_max_ac_coeff, basisu::iabs(coeff));
				}
			}
		}
		else
		{
			uint32_t zig_idx = 1;
			uint32_t coeff_ofs = 0;
			while (coeff_ofs < pSyms->m_coeffs.size())
			{
				const uint32_t run_len = pSyms->m_coeffs[coeff_ofs].m_num_zeros;
				const int coeff = pSyms->m_coeffs[coeff_ofs].m_coeff;
				coeff_ofs++;

				if ((run_len + zig_idx) > total_grid_samples)
					return false;

				zig_idx += run_len;

				if (zig_idx >= total_grid_samples)
					break;

				assert(coeff != INT16_MAX);

				int dct_idx = zigzag[zig_idx];

				const uint32_t y = (uint32_t)dct_idx / grid_width;
				const uint32_t x = (uint32_t)dct_idx % grid_width;
								
				const int quant = sample_quant_table(quant_state, x, y);
								
				dct_weights[dct_idx] = dequant_deadzone(coeff, quant, DEADZONE_ALPHA, x, y);

				if (pS)
				{
					++pS->m_total_coded_acs;
					pS->m_max_ac_coeff = basisu::maximum<uint32_t>(pS->m_max_ac_coeff, basisu::iabs(coeff));
				}

				zig_idx++;
			}
		}

		float idct_weights[astc_helpers::MAX_BLOCK_PIXELS];
				
		grid_dim_vals.m_dct.inverse(dct_weights, idct_weights, dct_work);

#if defined(_DEBUG) || defined(DEBUG)
		// Sanity check IDCT vs. less optimized variant
		// Also quant table sanity check vs. sample_quant_table().
		{
			float idct_weights_temp[astc_helpers::MAX_BLOCK_PIXELS];
			grid_dim_vals.m_dct.inverse_check(dct_weights, idct_weights_temp, dct_work);
						
			int dct_quant_tab[astc_helpers::MAX_BLOCK_PIXELS];
			compute_quant_table(q, grid_width, grid_height, level_scale, dct_quant_tab);

			for (uint32_t i = 0; i < grid_width * grid_height; i++)
			{
				assert(basisu::equal_tol(idct_weights[i], idct_weights_temp[i], .00125f));

				assert(!i || (dct_quant_tab[i] == sample_quant_table(quant_state, i % grid_width, i / grid_width)));
			}
		}
#endif

		// Compute final grid weights
		for (uint32_t y = 0; y < grid_height; y++)
			for (uint32_t x = 0; x < grid_width; x++)
				log_blk.m_weights[(x + y * grid_width) * num_planes + plane_index] = quant_tab[basisu::clamp(fast_roundf_int(mean_weight + idct_weights[x + y * grid_width]), 0, 64)];

		return true;
	}

	// results of calling scale_quant_steps() for each # of ASTC weight levels
	static const float g_scale_quant_steps[12] = { 1.51333141f, 1.41198814f, 1.35588217f, 1.31743157f, 1.28835952f, 1.24573100f, 1.21481407f, 1.19067919f, 1.15431654f, 1.12734985f, 1.10601568f, 1.07348967f };

	// Adaptive quantization
	float grid_weight_dct::compute_level_scale(float q, float span_len, uint32_t grid_width, uint32_t grid_height, uint32_t weight_ise_range) const
	{
		BASISU_NOTE_UNUSED(grid_width);
		BASISU_NOTE_UNUSED(grid_height);

		assert((weight_ise_range >= astc_helpers::BISE_2_LEVELS) && (weight_ise_range <= astc_helpers::BISE_32_LEVELS));

		// Standard JPEG quality factor calcs
		// TODO: Precompute this once
		float level_scale;
		q = basisu::clamp(q, 1.0f, 100.0f);
		if (q < 50.0f)
			level_scale = 5000.0f / q;
		else
			level_scale = 200.0f - 2.0f * q;

		level_scale *= (1.0f / 100.0f); // because JPEG's quant table is scaled by 100

		//const float span_floor = 28.0f;
		const float span_floor = 14.0f;
		//const float adaptive_factor = 255.0f / maximum<float>(span_len, span_floor);
		// 64.0 = dynamic range adjustment (JPEG uses 255)
		// divide by span len to adjust adaptive low/high values per-block (JPEG always uses effective span=0-255)
		// actually (64/255) * 255/max(span_len, span_floor)
		float adaptive_factor = 64.0f / basisu::maximum<float>(span_len, span_floor);

		// input signal scalar quantization noise will be distributed between multiple AC coefficients - compensate by adaptively adjusting the quant step size
		float weight_quant_adaptive_factor = g_scale_quant_steps[weight_ise_range];
		adaptive_factor *= weight_quant_adaptive_factor;

		// sanity
		assert(fabs(weight_quant_adaptive_factor - scale_quant_steps(astc_helpers::get_ise_levels(weight_ise_range))) < .000125f);
		
		// (Adaptive quant)
		level_scale *= adaptive_factor;

		// The higher the level_scale, the more quantized DCT coefficients will be and vice versa.

		return level_scale;
	}
	
	int grid_weight_dct::sample_quant_table(sample_quant_table_state& state, uint32_t x, uint32_t y) const
	{
		assert(x || y);
		
		if (state.m_q >= 100.0f)
			return 1;

		float ny = float(y);
		float ry = ny * state.m_sy;

		float nx = float(x);
		float rx = nx * state.m_sx;
				
		assert(x || y);

		// sample from the JPEG baseline luma 8x8 DCT quant matrix
		// this is an approximation (we could do an actual desired radians per spatial sample search vs. each of the 8x8 basis vectors to find the best, most conservative mapping), 
		// but for 4x4 and 6x6 block sizes it's reasonable enough and simple/fast
		// at 4x4, the lowest frequencies are slightly more heavily quantized than we would want (but the quant table entries near DC are so similar it's doubtful it matters much if at all)
		//float base = sample_jpeg_quant(g_baseline_jpeg_y, rx, ry);
		
		float base;
		{
			float i = rx, j = ry;
			assert((i >= 0.0f) && (j >= 0.0f));
			
			i = basisu::minimum(i, 7.0f);
			j = basisu::minimum(j, 7.0f);

			int i0 = (int)(i), j0 = (int)(j);
			int i1 = basisu::minimum(i0 + 1, 7), j1 = basisu::minimum(j0 + 1, 7);

			float ti = i - i0, tj = j - j0;
			float a = (1 - ti) * g_baseline_jpeg_y[j0][i0] + ti * g_baseline_jpeg_y[j0][i1];
			float b = (1 - ti) * g_baseline_jpeg_y[j1][i0] + ti * g_baseline_jpeg_y[j1][i1];

			base = (1 - tj) * a + tj * b;
		}
				
		int quant_scale = (int)(base * state.m_level_scale + 0.5f);
		
		quant_scale = basisu::maximum<int>(1, quant_scale);

		return quant_scale;
	}

	void grid_weight_dct::compute_quant_table(float q,
		uint32_t grid_width, uint32_t grid_height,
		float level_scale, int* dct_quant_tab) const
	{
		assert(q > 0.0f);

		dct_quant_tab[0] = 1;

		if (q >= 100.0f)
		{
			for (uint32_t y = 0; y < grid_height; y++)
				for (uint32_t x = 0; x < grid_width; x++)
					if (x || y)
						dct_quant_tab[x + y * grid_width] = 1;
			return;
		}
				
		const int Bx = m_block_width, By = m_block_height;

		const float sx = (float)8.0f / (float)Bx;
		const float sy = (float)8.0f / (float)By;

		for (uint32_t y = 0; y < grid_height; y++)
		{
			float ny = float(y);
			float ry = ny * sy;

			for (uint32_t x = y ? 0 : 1; x < grid_width; x++)
			{
				int quant_scale = 0;

				assert(x || y);
				
				float nx = float(x);
				float rx = nx * sx;

				// sample from the JPEG baseline luma 8x8 DCT quant matrix
				// this is an approximation (we could do an actual desired radians per spatial sample search vs. each of the 8x8 basis vectors to find the best, most conservative mapping), 
				// but for 4x4 and 6x6 block sizes it's reasonable enough and simple/fast
				// at 4x4, the lowest frequencies are slightly more heavily quantized than we would want (but the quant table entries near DC are so similar it's doubtful it matters much if at all)
				float base = sample_jpeg_quant(g_baseline_jpeg_y, rx, ry);

				//quant_scale = (int)std::floor(base * level_scale + 0.5f);
				quant_scale = (int)(base * level_scale + 0.5f);
				assert(quant_scale == (int)std::floor(base * level_scale + 0.5f));

				quant_scale = basisu::maximum<int>(1, quant_scale);

				dct_quant_tab[x + y * grid_width] = quant_scale;
			} // x
		} // y
	}

	// Needed by AQ
	float grid_weight_dct::get_max_span_len(const astc_helpers::log_astc_block& log_blk, uint32_t plane_index) const
	{
		float span_len = 0.0f;

		if (log_blk.m_dual_plane)
		{
			color32 l, h;
			decode_endpoints(log_blk.m_color_endpoint_modes[0], log_blk.m_endpoints, log_blk.m_endpoint_ise_range, l, h);

			for (uint32_t c = 0; c < 4; c++)
			{
				if (plane_index == 1)
				{
					if (c == log_blk.m_color_component_selector)
					{
						span_len += basisu::squaref((float)h[c] - (float)l[c]);
					}
				}
				else
				{
					if (c != log_blk.m_color_component_selector)
					{
						span_len += basisu::squaref((float)h[c] - (float)l[c]);
					}
				}
			}

			span_len = sqrtf(span_len);
		}
		else
		{
			for (uint32_t i = 0; i < log_blk.m_num_partitions; i++)
			{
				color32 l, h;
				decode_endpoints(log_blk.m_color_endpoint_modes[0], log_blk.m_endpoints + astc_helpers::get_num_cem_values(log_blk.m_color_endpoint_modes[0]) * i, log_blk.m_endpoint_ise_range, l, h);

				float part_span_len = sqrtf(
					basisu::squaref((float)h.r - (float)l.r) + basisu::squaref((float)h.g - (float)l.g) + basisu::squaref((float)h.b - (float)l.b) + basisu::squaref((float)h.a - (float)l.a)
				);

				span_len = basisu::maximum(part_span_len, span_len);
			}
		}

		return span_len;
	}
		
#include "basisu_astc_cfgs.inl"

	void create_encoder_trial_modes_table(uint32_t block_width, uint32_t block_height,
		basisu::vector<trial_mode>& encoder_trial_modes, grouped_trial_modes& grouped_encoder_trial_modes,
		bool print_debug_info, bool print_modes)
	{
		//interval_timer itm;
		//itm.start();

		uint32_t mode_index = 0;
		uint32_t max_grid_width = 0, max_grid_height = 0, max_grid_samples = 0;

		//encoder_trial_modes.reserve(BU_TOTAL_ASTC_CFGS);
		encoder_trial_modes.reserve(3072);
		encoder_trial_modes.resize(0);

		grouped_encoder_trial_modes.clear();

		for (uint32_t cfg_index = 0; cfg_index < BU_TOTAL_ASTC_CFGS; cfg_index++)
		{
			assert((cfg_index * 3 + 2) < std::size(s_astc_cfg_table));
			uint32_t packed_mode = s_astc_cfg_table[cfg_index * 3] | (s_astc_cfg_table[cfg_index * 3 + 1] << 8) | (s_astc_cfg_table[cfg_index * 3 + 2] << 16);

			uint32_t endpoint_ise_range, weight_ise_range, ccs_index, num_subsets, unique_cem_index, grid_wh;

#define BU_UNPACK_FIELD(val, bits) do { val = packed_mode & ((1u << (bits)) - 1u); packed_mode >>= (bits); } while(0)
			BU_UNPACK_FIELD(endpoint_ise_range, CFG_PACK_EISE_BITS);
			BU_UNPACK_FIELD(weight_ise_range, CFG_PACK_WISE_BITS);
			BU_UNPACK_FIELD(ccs_index, CFG_PACK_CCS_BITS);
			BU_UNPACK_FIELD(num_subsets, CFG_PACK_SUBSETS_BITS);
			BU_UNPACK_FIELD(unique_cem_index, CFG_PACK_CEM_BITS);
			BU_UNPACK_FIELD(grid_wh, CFG_PACK_GRID_BITS);
#undef BU_UNPACK_FIELD

			assert(!packed_mode);

			const uint32_t grid_width = (grid_wh / 11) + 2;

			// modes are sorted by grid widths, which is at/near the MSB of the packed values, rest must be >=
			if (grid_width > block_width)
				break;

			const uint32_t grid_height = (grid_wh % 11) + 2;
			if (grid_height > block_height)
				continue;

			const uint32_t cem_index = s_unique_ldr_index_to_astc_cem[unique_cem_index];

#if defined(_DEBUG) || defined(DEBUG)
			{
				// Ensure configuration is actually valid.
				astc_helpers::log_astc_block log_block;
				log_block.clear();
				log_block.m_grid_width = (uint8_t)grid_width;
				log_block.m_grid_height = (uint8_t)grid_height;
				log_block.m_num_partitions = (uint8_t)(num_subsets + 1);
				log_block.m_dual_plane = (ccs_index != 0);
				log_block.m_color_component_selector = (uint8_t)(ccs_index ? (ccs_index - 1) : 0);
				log_block.m_num_partitions = (uint8_t)(num_subsets + 1);
				log_block.m_endpoint_ise_range = (uint8_t)(endpoint_ise_range + astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE);
				log_block.m_weight_ise_range = (uint8_t)(weight_ise_range + astc_helpers::FIRST_VALID_WEIGHT_ISE_RANGE);

				for (uint32_t i = 0; i < log_block.m_num_partitions; i++)
					log_block.m_color_endpoint_modes[i] = (uint8_t)cem_index;

				astc_helpers::astc_block phys_block;
				bool pack_success = astc_helpers::pack_astc_block(phys_block, log_block, nullptr, nullptr, astc_helpers::cValidateSkipFinalEndpointWeightPacking);
				assert(pack_success);
			}
#endif

			const uint32_t tm_index = encoder_trial_modes.size_u32();
						
			trial_mode& tm = *encoder_trial_modes.enlarge(1);

			tm.m_ccs_index = (int)ccs_index - 1;
			tm.m_cem = cem_index;
			tm.m_endpoint_ise_range = endpoint_ise_range + astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE;
			tm.m_weight_ise_range = weight_ise_range;
			tm.m_grid_width = grid_width;
			tm.m_grid_height = grid_height;
			tm.m_num_parts = num_subsets + 1;

			grouped_encoder_trial_modes.add(block_width, block_height, tm, tm_index);

			if (print_modes)
			{
				max_grid_width = basisu::maximum(max_grid_width, grid_width);
				max_grid_height = basisu::maximum(max_grid_height, grid_height);
				max_grid_samples = basisu::maximum(max_grid_samples, grid_width * grid_height);

				basisu::debug_printf("%u: CEM: %u DP: %u, CCS: %i, SUBSETS: %u, GRID: %ux%u, ENDPOINTS: %u, WEIGHTS: %u\n",
					mode_index,
					tm.m_cem, tm.m_ccs_index >= 0, tm.m_ccs_index, tm.m_num_parts,
					tm.m_grid_width, tm.m_grid_height,
					astc_helpers::get_ise_levels(tm.m_endpoint_ise_range),
					astc_helpers::get_ise_levels(tm.m_weight_ise_range));
			}

			mode_index++;
		} // cfg_index

		if (print_debug_info)
		{
			//fmt_debug_printf("create_encoder_trial_modes_table() time: {} secs\n", itm.get_elapsed_secs());
			basisu::debug_printf("create_encoder_trial_modes_table() - ASTC %ux%u modes\n", block_width, block_height);
			basisu::debug_printf("Total used trial mode groups: %u\n", grouped_encoder_trial_modes.count_used_groups());
			basisu::debug_printf("Total ASTC configurations iterated (not including base+ofs variants): %u\n", mode_index);
			if (print_modes)
				basisu::fmt_debug_printf("Max grid dimensions: {}x{}, max grid samples: {}\n", max_grid_width, max_grid_height, max_grid_samples);
		}
	}

	// Cached encoder trial modes for each block size, to avoid having to compute this for every texture/mipmap level.
	basisu::vector<trial_mode> g_encoder_trial_modes[astc_helpers::cTOTAL_BLOCK_SIZES];
	grouped_trial_modes g_grouped_encoder_trial_modes[astc_helpers::cTOTAL_BLOCK_SIZES];

	grid_weight_dct g_grid_weight_dcts[astc_helpers::cTOTAL_BLOCK_SIZES];

	// These tables could be initialized per transcoded texture, but that would result in per-texture overhead.
	void init_transcoding_tables()
	{
		if (g_encoder_trial_modes[0].size())
			return;

		// We don't know what ASTC block sizes they're going to transcode, to prepare for all of them.
		for (uint32_t i = 0; i < astc_helpers::cTOTAL_BLOCK_SIZES; i++)
		{
			const uint32_t block_width = astc_helpers::g_astc_block_sizes[i][0];
			const uint32_t block_height = astc_helpers::g_astc_block_sizes[i][1];

			auto& encoder_trial_modes = g_encoder_trial_modes[i];
			auto& grouped_encoder_trial_modes = g_grouped_encoder_trial_modes[i];

			encoder_trial_modes.reserve(3072);
						
			const bool print_debug_info = false;
			const bool print_modes = false;
			create_encoder_trial_modes_table(block_width, block_height, encoder_trial_modes, grouped_encoder_trial_modes, print_debug_info, print_modes);

			g_grid_weight_dcts[i].init(block_width, block_height);
		} // i
	}

	const uint16_t g_total_unique_patterns[astc_helpers::NUM_ASTC_BLOCK_SIZES][2] = // [block_size][subsets-1]
	{
		{ 437, 329 }, { 559, 405 }, { 659, 486 }, { 720, 534 },
		{ 521, 333 }, { 584, 377 }, { 640, 410 }, { 672, 436 },
		{ 710, 468 }, { 701, 476 }, { 759, 528 }, { 799, 568 },
		{ 818, 597 }, { 838, 626 }
	};

	uint32_t get_total_unique_patterns(uint32_t astc_block_size_index, uint32_t num_parts)
	{
		assert(astc_block_size_index < astc_helpers::NUM_ASTC_BLOCK_SIZES);
		assert((num_parts >= 2) && (num_parts <= 3));
	
		return g_total_unique_patterns[astc_block_size_index][num_parts - 2];
	}

	const uint16_t g_unique_to_seed_4x4_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,20,21,23,24,25,26,27,28,29,30,33,36,37,39,42,43,44,45,47,48,49,50,51,53,54,55,56,58,59,61,62,63,65,66,68,69,70,71,72,73,74,75,76,78,83,87,89,90,91,94,95,98,99,100,101,107,108,109,110,111,113,114,115,116,119,121,122,124,125,128,129,130,131,134,135,137,138,139,142,143,144,146,147,149,150,151,156,158,159,161,165,167,168,169,170,171,172,174,175,177,181,183,184,191,194,195,196,198,199,203,204,206,207,208,210,211,213,214,215,216,218,220,222,226,227,230,231,232,235,236,239,245,246,247,248,249,250,252,253,254,255,257,258,260,262,264,270,271,273,277,278,279,280,281,284,291,293,299,302,304,305,306,307,309,314,319,324,325,326,327,329,330,335,337,339,341,343,344,347,348,351,352,354,355,359,362,368,370,373,374,375,376,380,386,387,388,389,394,395,399,404,409,411,412,418,419,422,423,426,430,432,438,441,443,445,447,453,455,463,471,474,475,476,478,479,484,487,488,489,490,491,495,496,498,500,504,510,511,513,517,518,523,524,526,527,529,530,531,534,539,542,546,547,549,553,558,567,578,581,583,586,587,591,593,594,595,598,600,601,602,605,607,611,612,614,615,619,622,625,627,631,633,634,638,639,643,647,649,655,658,661,662,663,664,666,672,673,674,681,683,684,686,690,693,694,695,696,700,703,705,707,713,716,719,720,724,726,727,730,731,732,736,742,751,754,756,762,764,766,769,770,773,774,778,780,789,791,796,798,799,801,802,804,807,810,811,812,818,819,821,826,828,831,833,834,836,839,840,842,847,849,852,868,872,873,877,881,886,887,888,890,895,897,898,899,902,903,906,911,914,915,919,923,924,930,934,937,938,943,945,947,948,950,951,954,958,959,963,964,966,967,971,976,983,987,988,993,994,995,998,999,1006,1007,1009,1013,1014,1015,1016,1019,1022,1023 } ;
	const uint16_t g_unique_to_seed_5x4_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,20,21,23,24,25,26,27,28,29,30,31,33,36,37,39,42,43,44,45,47,48,49,50,51,53,54,55,56,58,59,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,78,83,87,88,89,90,91,94,95,97,98,99,100,101,107,108,109,110,111,113,114,115,116,119,121,122,124,125,128,129,130,131,132,134,135,137,138,139,142,143,144,145,146,147,149,150,151,153,154,156,157,158,159,161,165,167,168,169,170,171,172,174,175,177,181,183,184,185,188,190,191,194,195,196,198,199,200,203,204,206,207,208,210,211,213,214,215,216,217,218,220,222,225,226,227,229,230,231,232,235,236,239,245,246,247,248,249,250,252,253,254,255,257,258,260,261,262,264,265,267,270,271,273,275,277,278,279,280,281,282,284,287,291,293,295,296,299,300,302,304,305,306,307,309,314,317,319,323,324,325,326,327,329,330,332,335,337,339,341,342,343,344,347,348,349,350,351,352,354,355,359,361,362,365,368,370,373,374,375,376,380,381,386,387,388,389,391,394,395,399,404,405,407,409,410,411,412,418,419,420,422,423,426,430,432,438,439,441,443,445,447,449,453,454,455,462,463,465,471,473,474,475,476,478,479,482,484,486,487,488,489,490,491,495,496,498,500,501,503,504,505,508,510,511,513,516,517,518,519,521,523,524,526,527,529,530,531,533,534,538,539,542,546,547,549,550,551,553,554,558,563,567,569,572,575,578,579,581,583,586,587,591,593,594,595,598,600,601,602,605,606,607,608,611,612,614,615,616,619,622,623,625,627,631,633,634,636,638,639,643,645,647,649,652,655,658,661,662,663,664,665,666,668,672,673,674,675,681,683,684,686,687,690,692,693,694,695,696,697,700,702,703,705,707,709,711,713,716,719,720,724,725,726,727,730,731,732,736,739,742,748,751,754,756,758,762,763,764,766,768,769,770,772,773,774,776,778,780,782,786,789,791,792,796,798,799,801,802,804,807,810,811,812,814,818,819,821,823,826,828,830,831,833,834,835,836,839,840,842,845,847,849,852,858,861,866,868,870,871,872,873,876,877,878,881,886,887,888,890,891,895,897,898,899,901,902,903,906,909,911,914,915,919,923,924,927,929,930,933,934,935,936,937,938,941,942,943,945,947,948,950,951,954,955,958,959,963,964,966,967,970,971,975,976,980,983,986,987,988,993,994,995,997,998,999,1001,1006,1007,1009,1010,1013,1014,1015,1016,1019,1020,1022,1023 };
	const uint16_t g_unique_to_seed_5x5_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,20,21,23,24,25,26,27,28,29,30,31,33,34,36,37,39,42,43,44,45,47,48,49,50,51,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,81,82,83,87,88,89,90,91,92,94,95,97,98,99,100,101,105,107,108,109,110,111,113,114,115,116,119,120,121,122,124,125,128,129,130,131,132,134,135,137,138,139,142,143,144,145,146,147,148,149,150,151,153,154,155,156,157,158,159,161,165,167,168,169,170,171,172,174,175,176,177,181,182,183,184,185,188,190,191,193,194,195,196,198,199,200,203,204,206,207,208,209,210,211,213,214,215,216,217,218,220,222,224,225,226,227,229,230,231,232,235,236,239,240,242,245,246,247,248,249,250,252,253,254,255,256,257,258,260,261,262,264,265,267,270,271,273,275,276,277,278,279,280,281,282,283,284,286,287,289,291,293,294,295,296,298,299,300,302,303,304,305,306,307,309,313,314,317,318,319,323,324,325,326,327,329,330,331,332,335,337,338,339,341,342,343,344,347,348,349,350,351,352,354,355,356,359,361,362,365,368,370,373,374,375,376,377,378,380,381,386,387,388,389,390,391,392,393,394,395,399,403,404,405,407,409,410,411,412,415,418,419,420,421,422,423,424,426,430,432,433,437,438,439,440,441,443,444,445,446,447,449,453,454,455,458,462,463,465,466,469,470,471,473,474,475,476,478,479,481,482,484,486,487,488,489,490,491,492,495,496,498,500,501,502,503,504,505,506,508,509,510,511,513,516,517,518,519,521,523,524,526,527,529,530,531,533,534,538,539,542,546,547,548,549,550,551,553,554,558,559,561,562,563,567,569,572,575,578,579,580,581,583,585,586,587,590,591,593,594,595,596,598,599,600,601,602,605,606,607,608,609,610,611,612,614,615,616,617,619,620,621,622,623,625,627,631,633,634,636,638,639,643,645,646,647,648,649,652,654,655,658,661,662,663,664,665,666,668,672,673,674,675,681,683,684,686,687,688,690,692,693,694,695,696,697,699,700,701,702,703,705,707,709,711,713,714,716,719,720,722,724,725,726,727,730,731,732,736,738,739,742,748,751,753,754,756,758,760,762,763,764,766,768,769,770,772,773,774,776,778,780,782,783,786,789,791,792,796,798,799,801,802,804,806,807,808,810,811,812,813,814,818,819,821,823,826,828,830,831,833,834,835,836,839,840,841,842,845,847,849,851,852,858,861,866,868,869,870,871,872,873,874,876,877,878,879,881,886,887,888,890,891,893,894,895,897,898,899,901,902,903,906,909,910,911,912,914,915,917,919,920,921,923,924,927,929,930,933,934,935,936,937,938,941,942,943,945,947,948,950,951,954,955,958,959,961,962,963,964,966,967,968,970,971,975,976,977,980,983,986,987,988,993,994,995,996,997,998,999,1001,1006,1007,1009,1010,1013,1014,1015,1016,1018,1019,1020,1022,1023 };
	const uint16_t g_unique_to_seed_6x5_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,20,21,23,24,25,26,27,28,29,30,31,33,34,36,37,39,42,43,44,45,47,48,49,50,51,52,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,86,87,88,89,90,91,92,94,95,97,98,99,100,101,105,107,108,109,110,111,112,113,114,115,116,117,119,120,121,122,123,124,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,145,146,147,148,149,150,151,153,154,155,156,157,158,159,161,165,167,168,169,170,171,172,174,175,176,177,178,181,182,183,184,185,188,190,191,193,194,195,196,198,199,200,201,203,204,206,207,208,209,210,211,212,213,214,215,216,217,218,220,222,223,224,225,226,227,229,230,231,232,235,236,239,240,242,243,245,246,247,248,249,250,252,253,254,255,256,257,258,260,261,262,264,265,266,267,270,271,273,275,276,277,278,279,280,281,282,283,284,286,287,289,291,293,294,295,296,298,299,300,302,303,304,305,306,307,309,310,313,314,317,318,319,323,324,325,326,327,329,330,331,332,335,337,338,339,341,342,343,344,347,348,349,350,351,352,354,355,356,357,359,360,361,362,363,365,367,368,370,371,373,374,375,376,377,378,380,381,383,386,387,388,389,390,391,392,393,394,395,399,402,403,404,405,407,409,410,411,412,415,418,419,420,421,422,423,424,426,430,432,433,436,437,438,439,440,441,443,444,445,446,447,449,453,454,455,458,461,462,463,465,466,469,470,471,473,474,475,476,478,479,481,482,484,486,487,488,489,490,491,492,493,495,496,498,499,500,501,502,503,504,505,506,508,509,510,511,513,516,517,518,519,521,523,524,526,527,529,530,531,532,533,534,536,538,539,542,543,545,546,547,548,549,550,551,553,554,558,559,561,562,563,564,567,569,570,572,575,578,579,580,581,583,584,585,586,587,590,591,593,594,595,596,597,598,599,600,601,602,605,606,607,608,609,610,611,612,614,615,616,617,619,620,621,622,623,624,625,627,628,629,631,633,634,636,638,639,643,645,646,647,648,649,651,652,654,655,657,658,661,662,663,664,665,666,668,672,673,674,675,681,683,684,686,687,688,690,692,693,694,695,696,697,699,700,701,702,703,705,706,707,709,711,713,714,716,719,720,722,723,724,725,726,727,730,731,732,736,738,739,742,745,747,748,751,753,754,756,758,760,762,763,764,766,768,769,770,772,773,774,776,778,780,782,783,784,786,788,789,791,792,795,796,798,799,801,802,804,806,807,808,810,811,812,813,814,818,819,820,821,823,826,828,830,831,833,834,835,836,839,840,841,842,845,847,849,851,852,856,858,861,866,868,869,870,871,872,873,874,875,876,877,878,879,881,883,886,887,888,890,891,893,894,895,896,897,898,899,901,902,903,906,908,909,910,911,912,914,915,917,919,920,921,923,924,927,929,930,932,933,934,935,936,937,938,941,942,943,945,947,948,950,951,954,955,956,958,959,960,961,962,963,964,966,967,968,970,971,972,975,976,977,979,980,982,983,986,987,988,993,994,995,996,997,998,999,1001,1004,1006,1007,1009,1010,1013,1014,1015,1016,1017,1018,1019,1020,1022,1023 };
	const uint16_t g_unique_to_seed_6x6_p2[] = { 1,2,3,4,5,7,8,9,10,11,14,15,16,17,18,19,21,23,24,25,26,27,28,29,31,33,36,37,39,42,43,44,45,46,47,48,49,50,51,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,73,74,75,76,77,78,79,83,86,87,88,89,90,91,94,95,98,99,100,101,103,107,108,109,110,112,114,115,116,119,121,122,125,128,129,130,131,132,134,135,136,137,138,139,142,144,146,147,148,149,151,153,154,156,158,159,167,168,169,170,171,172,174,175,177,178,181,183,190,191,193,194,195,196,198,199,203,206,207,210,211,213,214,215,216,217,218,220,222,223,225,226,227,229,230,231,232,235,236,237,240,247,249,250,252,254,255,257,258,260,262,264,266,267,270,271,272,273,277,278,279,281,283,284,286,289,291,292,293,295,298,299,302,303,305,306,307,309,314,316,318,319,323,324,326,327,329,335,339,341,343,347,348,351,352,353,354,355,361,362,363,366,367,368,370,373,374,376,380,386,387,388,389,390,392,393,394,395,402,403,404,407,409,411,414,415,418,419,422,423,426,430,432,433,436,437,438,439,440,441,445,447,450,452,453,455,458,461,463,470,471,474,475,476,478,480,482,486,487,488,490,495,496,498,499,500,504,506,508,510,513,517,518,519,521,523,524,526,527,529,530,531,533,534,538,539,543,545,546,547,549,550,551,553,554,558,562,567,569,572,578,581,583,585,586,587,591,593,594,595,596,598,600,601,602,606,607,608,610,611,612,614,615,616,619,621,622,623,625,627,631,633,634,638,639,643,645,646,647,648,649,652,655,658,661,662,663,664,665,670,672,673,674,675,681,683,684,685,686,687,688,690,691,693,694,695,696,697,700,702,703,705,713,714,716,719,720,722,724,726,727,730,731,732,736,740,742,751,753,754,756,758,760,762,763,764,766,769,770,774,778,780,786,789,791,794,797,798,799,801,802,804,805,807,808,810,811,812,817,819,821,822,826,828,831,834,835,836,839,842,847,852,854,858,862,868,869,870,872,874,876,877,878,886,887,890,891,893,895,897,898,899,902,903,906,909,910,911,912,914,919,929,930,934,936,937,938,942,943,945,947,948,950,951,954,955,958,959,963,964,966,967,968,976,980,983,987,988,993,994,995,998,999,1001,1006,1007,1008,1009,1013,1014,1015,1016,1019,1022,1023 };
	const uint16_t g_unique_to_seed_8x5_p2[] = { 1,2,3,4,5,7,8,9,10,11,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,36,37,39,42,43,45,46,47,48,49,50,51,53,54,55,56,58,59,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,83,86,87,88,89,90,91,94,95,98,99,100,101,103,107,108,109,110,112,114,115,116,119,121,122,123,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,146,147,148,149,150,151,154,156,158,159,165,167,168,169,170,171,172,174,175,177,178,181,183,184,191,193,194,195,196,198,199,203,204,206,207,209,210,211,213,214,215,216,217,218,220,222,225,226,227,229,230,231,232,235,236,237,240,247,248,249,250,252,253,254,255,257,258,260,261,262,264,266,267,270,271,272,273,277,278,279,281,284,286,287,289,291,292,293,295,296,298,299,300,302,303,304,305,306,307,309,314,316,317,318,319,323,324,325,326,327,329,330,335,337,339,341,342,343,344,347,348,351,352,353,354,355,359,361,362,363,366,367,368,370,371,374,375,376,380,381,386,387,388,389,390,391,392,393,394,395,399,402,403,404,405,407,409,410,411,412,415,418,419,422,423,424,426,430,432,433,436,437,438,439,440,441,444,445,446,447,450,451,452,453,454,455,458,461,462,463,465,470,471,473,474,475,476,478,479,482,484,486,487,488,490,491,495,496,498,499,500,501,502,504,505,506,508,510,511,513,517,518,519,521,523,524,526,527,530,531,533,534,535,538,539,543,545,546,547,550,551,554,558,559,562,567,569,572,578,579,581,583,585,586,587,591,593,594,595,598,600,601,602,606,607,608,610,611,612,614,615,618,619,621,622,623,625,627,631,633,636,638,639,643,645,646,647,648,649,650,651,652,655,658,659,661,662,663,664,665,666,668,672,673,674,675,683,684,685,686,687,688,690,691,692,693,694,695,696,697,700,701,702,703,705,707,711,713,716,719,720,722,724,725,726,727,730,731,732,736,739,740,742,748,751,753,754,756,758,760,762,763,764,766,768,770,774,775,778,780,786,789,791,794,796,798,799,801,802,804,805,807,808,810,811,812,813,817,819,821,825,826,831,834,836,839,841,842,845,847,849,851,852,854,856,862,868,869,870,871,872,874,876,877,879,881,886,887,890,891,893,895,897,898,899,902,903,906,909,910,911,914,915,918,919,921,923,924,927,929,930,934,936,937,938,942,943,945,947,948,951,954,955,958,959,962,963,964,966,967,968,970,971,976,977,979,983,987,988,989,993,994,995,997,998,999,1001,1006,1007,1008,1009,1013,1015,1016,1018,1019,1022,1023 };
	const uint16_t g_unique_to_seed_8x6_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,36,37,39,42,43,44,45,46,47,48,49,50,51,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,83,86,87,88,89,90,91,94,95,98,99,100,101,103,107,108,109,110,112,113,114,115,116,119,121,122,123,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,146,147,148,149,150,151,153,154,156,158,159,165,167,168,169,170,171,172,174,175,177,178,181,183,184,190,191,193,194,195,196,198,199,200,203,204,206,207,208,209,210,211,213,214,215,216,217,218,220,222,223,225,226,227,229,230,231,232,235,236,237,240,245,246,247,248,249,250,252,253,254,255,257,258,260,261,262,264,266,267,270,271,272,273,277,278,279,281,283,284,286,287,289,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,314,316,317,318,319,323,324,325,326,327,329,330,335,337,339,341,342,343,344,347,348,349,350,351,352,353,354,355,359,361,362,363,365,366,367,368,370,371,373,374,375,376,380,381,386,387,388,389,390,391,392,393,394,395,399,402,403,404,405,407,409,410,411,412,414,415,418,419,422,423,424,426,430,432,433,436,437,438,439,440,441,443,444,445,446,447,450,451,452,453,454,455,458,461,462,463,465,470,471,473,474,475,476,478,479,480,482,484,486,487,488,489,490,491,495,496,498,499,500,501,502,504,505,506,508,510,511,513,517,518,519,521,523,524,526,527,529,530,531,533,534,535,538,539,543,545,546,547,549,550,551,553,554,558,559,562,567,569,572,575,578,579,581,583,585,586,587,591,593,594,595,596,598,600,601,602,606,607,608,610,611,612,614,615,616,618,619,621,622,623,625,627,631,633,634,636,638,639,643,645,646,647,648,649,650,651,652,655,658,659,661,662,663,664,665,666,668,670,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,700,701,702,703,705,707,711,713,714,716,719,720,722,724,725,726,727,730,731,732,736,739,740,742,748,751,753,754,756,758,760,762,763,764,766,768,769,770,773,774,775,776,778,780,786,789,791,792,794,796,797,798,799,801,802,804,805,807,808,810,811,812,813,817,818,819,821,822,825,826,828,830,831,833,834,835,836,839,841,842,845,847,849,851,852,854,856,858,861,862,868,869,870,871,872,873,874,876,877,878,879,881,886,887,888,890,891,893,895,897,898,899,902,903,906,909,910,911,912,914,915,918,919,921,923,924,927,929,930,933,934,935,936,937,938,940,942,943,945,947,948,950,951,954,955,958,959,962,963,964,966,967,968,970,971,976,977,979,980,983,986,987,988,989,993,994,995,997,998,999,1001,1006,1007,1008,1009,1013,1014,1015,1016,1018,1019,1021,1022,1023 };
	const uint16_t g_unique_to_seed_10x5_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,36,37,39,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,59,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,83,84,85,86,87,88,89,90,91,94,95,97,98,99,100,101,103,107,108,109,110,112,113,114,115,116,119,121,122,123,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,145,146,147,148,149,150,151,153,154,155,156,157,158,159,165,167,168,169,170,171,172,174,175,177,178,181,183,184,185,188,191,193,194,195,196,198,199,200,203,204,206,207,208,209,210,211,213,214,215,216,217,218,219,220,222,223,225,226,227,229,230,231,232,235,236,237,238,239,240,247,248,249,250,252,253,254,255,257,258,260,261,262,263,264,265,266,267,270,271,272,273,275,277,278,279,281,282,283,284,286,287,289,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,314,316,317,318,319,323,324,325,326,327,329,330,332,335,337,339,341,342,343,344,347,348,349,350,351,352,353,354,355,358,359,361,362,363,365,366,367,368,370,371,374,375,376,380,381,386,387,388,389,390,391,392,393,394,395,399,402,403,404,405,407,409,410,411,412,415,418,419,422,423,424,426,429,430,432,433,436,437,438,439,440,441,443,444,445,446,447,449,450,451,452,453,454,455,458,461,462,463,465,470,471,473,474,475,476,478,479,481,482,484,486,487,488,489,490,491,492,495,496,498,499,500,501,502,503,504,505,506,508,510,511,513,517,518,519,521,523,524,526,527,529,530,531,533,534,535,538,539,542,543,545,546,547,548,550,551,554,558,559,562,567,569,570,571,572,575,578,579,580,581,583,585,586,587,591,593,594,595,597,598,600,601,602,606,607,608,609,610,611,612,614,615,616,617,618,619,621,622,623,624,625,627,631,633,634,636,638,639,643,645,646,647,648,649,650,651,652,655,657,658,659,661,662,663,664,665,666,668,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,699,700,701,702,703,705,706,707,711,713,716,719,720,722,723,724,725,726,727,730,731,732,736,739,740,742,748,751,753,754,755,756,757,758,760,762,763,764,766,768,770,773,774,775,776,778,780,786,789,791,794,795,796,798,799,801,802,804,805,807,808,810,811,812,813,814,817,818,819,821,822,823,825,826,828,830,831,834,835,836,839,841,842,845,847,849,851,852,854,856,862,868,869,870,871,872,873,874,876,877,878,879,881,883,886,887,888,890,891,893,895,897,898,899,901,902,903,906,909,910,911,914,915,918,919,920,921,923,924,927,929,930,932,933,934,935,936,937,938,941,942,943,945,947,948,950,951,954,955,956,958,959,961,962,963,964,966,967,968,969,970,971,975,976,977,979,980,983,986,987,988,989,993,994,995,996,997,998,999,1001,1006,1007,1008,1009,1013,1014,1015,1016,1017,1018,1019,1020,1022,1023 };
	const uint16_t g_unique_to_seed_10x6_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,36,37,39,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,83,84,85,86,87,88,89,90,91,94,95,97,98,99,100,101,103,107,108,109,110,112,113,114,115,116,119,121,122,123,124,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,145,146,147,148,149,150,151,153,154,155,156,157,158,159,165,167,168,169,170,171,172,174,175,177,178,181,183,184,185,188,190,191,193,194,195,196,198,199,200,203,204,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,225,226,227,229,230,231,232,235,236,237,238,239,240,245,246,247,248,249,250,252,253,254,255,257,258,260,261,262,263,264,265,266,267,270,271,272,273,274,275,277,278,279,281,282,283,284,286,287,289,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,310,314,316,317,318,319,323,324,325,326,327,329,330,332,335,337,338,339,341,342,343,344,347,348,349,350,351,352,353,354,355,358,359,361,362,363,365,366,367,368,370,371,373,374,375,376,380,381,386,387,388,389,390,391,392,393,394,395,399,402,403,404,405,407,409,410,411,412,414,415,418,419,422,423,424,426,429,430,432,433,436,437,438,439,440,441,443,444,445,446,447,449,450,451,452,453,454,455,458,461,462,463,465,470,471,473,474,475,476,478,479,480,481,482,484,486,487,488,489,490,491,492,495,496,498,499,500,501,502,503,504,505,506,508,509,510,511,513,516,517,518,519,521,523,524,526,527,529,530,531,533,534,535,538,539,542,543,545,546,547,548,549,550,551,553,554,558,559,562,567,569,570,571,572,575,578,579,580,581,583,585,586,587,590,591,593,594,595,596,597,598,600,601,602,606,607,608,609,610,611,612,614,615,616,617,618,619,621,622,623,624,625,627,631,633,634,636,638,639,643,645,646,647,648,649,650,651,652,655,657,658,659,661,662,663,664,665,666,668,670,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,699,700,701,702,703,705,706,707,709,711,713,714,716,719,720,722,723,724,725,726,727,730,731,732,736,739,740,742,748,751,753,754,755,756,757,758,760,762,763,764,766,768,769,770,772,773,774,775,776,778,780,782,783,786,788,789,791,792,794,795,796,797,798,799,801,802,804,805,807,808,810,811,812,813,814,817,818,819,821,822,823,825,826,828,830,831,833,834,835,836,839,841,842,845,847,849,851,852,854,856,858,861,862,868,869,870,871,872,873,874,876,877,878,879,881,883,886,887,888,890,891,893,895,897,898,899,901,902,903,906,908,909,910,911,912,914,915,918,919,920,921,923,924,927,929,930,932,933,934,935,936,937,938,940,941,942,943,945,947,948,949,950,951,954,955,956,958,959,961,962,963,964,966,967,968,969,970,971,975,976,977,979,980,983,986,987,988,989,993,994,995,996,997,998,999,1001,1004,1006,1007,1008,1009,1013,1014,1015,1016,1017,1018,1019,1020,1021,1022,1023 };
	const uint16_t g_unique_to_seed_8x8_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,36,37,39,42,43,44,45,46,47,48,49,50,51,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,83,86,87,88,89,90,91,94,95,97,98,99,100,101,102,103,107,108,109,110,111,112,113,114,115,116,118,119,120,121,122,123,124,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,146,147,148,149,150,151,152,153,154,155,156,158,159,161,165,167,168,169,170,171,172,174,175,177,178,181,182,183,184,188,190,191,193,194,195,196,198,199,200,201,203,204,206,207,208,209,210,211,213,214,215,216,217,218,220,222,223,224,225,226,227,229,230,231,232,235,236,237,239,240,242,245,246,247,248,249,250,252,253,254,255,257,258,260,261,262,264,265,266,267,270,271,272,273,276,277,278,279,280,281,282,283,284,286,287,289,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,314,316,317,318,319,323,324,325,326,327,329,330,331,332,333,335,337,338,339,341,342,343,344,347,348,349,350,351,352,353,354,355,359,361,362,363,365,366,367,368,370,371,373,374,375,376,380,381,386,387,388,389,390,391,392,393,394,395,399,400,402,403,404,405,407,409,410,411,412,414,415,418,419,420,422,423,424,426,430,432,433,436,437,438,439,440,441,443,444,445,446,447,450,451,452,453,454,455,458,461,462,463,465,466,470,471,473,474,475,476,478,479,480,481,482,484,486,487,488,489,490,491,495,496,498,499,500,501,502,503,504,505,506,508,510,511,513,516,517,518,519,521,523,524,526,527,529,530,531,533,534,535,538,539,542,543,545,546,547,548,549,550,551,553,554,558,559,562,563,567,569,572,575,578,579,580,581,583,585,586,587,590,591,593,594,595,596,598,599,600,601,602,605,606,607,608,609,610,611,612,614,615,616,618,619,620,621,622,623,625,627,631,633,634,636,638,639,643,645,646,647,648,649,650,651,652,655,658,659,661,662,663,664,665,666,668,670,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,700,701,702,703,705,707,709,711,713,714,716,719,720,722,724,725,726,727,730,731,732,736,739,740,742,743,748,751,753,754,755,756,757,758,760,762,763,764,766,768,769,770,772,773,774,775,776,778,780,782,783,786,789,791,792,793,794,796,797,798,799,801,802,804,805,806,807,808,810,811,812,813,814,817,818,819,821,822,825,826,828,830,831,833,834,835,836,839,840,841,842,845,847,849,851,852,854,856,858,861,862,866,868,869,870,871,872,873,874,876,877,878,879,881,886,887,888,890,891,893,894,895,897,898,899,901,902,903,906,908,909,910,911,912,914,915,916,917,918,919,921,923,924,927,929,930,933,934,935,936,937,938,940,942,943,945,947,948,949,950,951,954,955,956,958,959,962,963,964,966,967,968,969,970,971,975,976,977,979,980,983,986,987,988,989,993,994,995,997,998,999,1001,1006,1007,1008,1009,1010,1013,1014,1015,1016,1018,1019,1020,1021,1022,1023 };
	const uint16_t g_unique_to_seed_10x8_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,34,36,37,39,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,83,84,85,86,87,88,89,90,91,92,94,95,97,98,99,100,101,102,103,105,107,108,109,110,111,112,113,114,115,116,118,119,120,121,122,123,124,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,161,165,167,168,169,170,171,172,174,175,177,178,179,180,181,182,183,184,185,188,190,191,193,194,195,196,198,199,200,201,203,204,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225,226,227,229,230,231,232,235,236,237,238,239,240,242,245,246,247,248,249,250,252,253,254,255,257,258,260,261,262,263,264,265,266,267,270,271,272,273,274,275,276,277,278,279,280,281,282,283,284,286,287,289,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,310,314,316,317,318,319,321,323,324,325,326,327,329,330,331,332,333,335,337,338,339,341,342,343,344,347,348,349,350,351,352,353,354,355,358,359,361,362,363,365,366,367,368,370,371,373,374,375,376,378,380,381,385,386,387,388,389,390,391,392,393,394,395,399,400,402,403,404,405,407,409,410,411,412,414,415,418,419,420,422,423,424,426,429,430,432,433,436,437,438,439,440,441,443,444,445,446,447,449,450,451,452,453,454,455,458,461,462,463,465,466,469,470,471,473,474,475,476,478,479,480,481,482,484,486,487,488,489,490,491,492,495,496,498,499,500,501,502,503,504,505,506,508,509,510,511,513,516,517,518,519,520,521,523,524,526,527,529,530,531,533,534,535,538,539,542,543,545,546,547,548,549,550,551,553,554,558,559,562,563,567,569,570,571,572,575,578,579,580,581,583,584,585,586,587,590,591,593,594,595,596,597,598,599,600,601,602,605,606,607,608,609,610,611,612,614,615,616,617,618,619,620,621,622,623,624,625,627,628,629,631,633,634,636,638,639,643,645,646,647,648,649,650,651,652,655,657,658,659,661,662,663,664,665,666,668,670,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,699,700,701,702,703,705,706,707,709,711,713,714,716,719,720,722,723,724,725,726,727,730,731,732,736,739,740,742,743,745,747,748,751,753,754,755,756,757,758,760,762,763,764,766,768,769,770,772,773,774,775,776,778,780,781,782,783,786,788,789,791,792,793,794,795,796,797,798,799,801,802,804,805,806,807,808,810,811,812,813,814,817,818,819,821,822,823,825,826,828,830,831,833,834,835,836,839,840,841,842,845,847,849,851,852,854,856,858,861,862,866,868,869,870,871,872,873,874,876,877,878,879,880,881,883,886,887,888,890,891,893,894,895,897,898,899,901,902,903,906,908,909,910,911,912,914,915,916,917,918,919,920,921,923,924,927,929,930,932,933,934,935,936,937,938,940,941,942,943,945,947,948,949,950,951,954,955,956,958,959,960,961,962,963,964,966,967,968,969,970,971,975,976,977,979,980,982,983,986,987,988,989,993,994,995,996,997,998,999,1001,1004,1006,1007,1008,1009,1010,1013,1014,1015,1016,1017,1018,1019,1020,1021,1022,1023 };
	const uint16_t g_unique_to_seed_10x10_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,34,36,37,39,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,81,82,83,84,85,86,87,88,89,90,91,92,94,95,97,98,99,100,101,102,103,105,107,108,109,110,111,112,113,114,115,116,118,119,120,121,122,123,124,125,128,129,130,131,132,134,135,136,137,138,139,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,161,165,167,168,169,170,171,172,174,175,176,177,178,179,180,181,182,183,184,185,188,190,191,193,194,195,196,198,199,200,201,202,203,204,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225,226,227,229,230,231,232,235,236,237,238,239,240,242,245,246,247,248,249,250,252,253,254,255,256,257,258,260,261,262,263,264,265,266,267,270,271,272,273,274,275,276,277,278,279,280,281,282,283,284,286,287,289,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,310,313,314,316,317,318,319,321,323,324,325,326,327,329,330,331,332,333,335,337,338,339,341,342,343,344,347,348,349,350,351,352,353,354,355,356,357,358,359,360,361,362,363,365,366,367,368,370,371,373,374,375,376,377,378,380,381,385,386,387,388,389,390,391,392,393,394,395,399,400,402,403,404,405,407,409,410,411,412,414,415,417,418,419,420,421,422,423,424,425,426,427,428,429,430,432,433,436,437,438,439,440,441,443,444,445,446,447,449,450,451,452,453,454,455,458,459,461,462,463,465,466,469,470,471,473,474,475,476,478,479,480,481,482,484,486,487,488,489,490,491,492,493,494,495,496,498,499,500,501,502,503,504,505,506,508,509,510,511,513,514,516,517,518,519,520,521,522,523,524,526,527,528,529,530,531,532,533,534,535,536,538,539,542,543,545,546,547,548,549,550,551,553,554,558,559,561,562,563,566,567,569,570,571,572,575,578,579,580,581,583,584,585,586,587,590,591,593,594,595,596,597,598,599,600,601,602,605,606,607,608,609,610,611,612,614,615,616,617,618,619,620,621,622,623,624,625,627,628,629,631,633,634,636,638,639,643,645,646,647,648,649,650,651,652,654,655,657,658,659,661,662,663,664,665,666,667,668,670,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,699,700,701,702,703,705,706,707,709,711,713,714,716,719,720,722,723,724,725,726,727,730,731,732,736,738,739,740,742,743,745,747,748,751,753,754,755,756,757,758,760,762,763,764,766,768,769,770,771,772,773,774,775,776,778,780,781,782,783,784,786,788,789,791,792,793,794,795,796,797,798,799,801,802,803,804,805,806,807,808,810,811,812,813,814,817,818,819,820,821,822,823,825,826,828,829,830,831,833,834,835,836,839,840,841,842,845,846,847,848,849,851,852,854,855,856,858,861,862,866,867,868,869,870,871,872,873,874,876,877,878,879,880,881,883,886,887,888,890,891,893,894,895,896,897,898,899,901,902,903,904,906,908,909,910,911,912,914,915,916,917,918,919,920,921,923,924,927,929,930,932,933,934,935,936,937,938,940,941,942,943,945,947,948,949,950,951,954,955,956,958,959,960,961,962,963,964,966,967,968,969,970,971,972,975,976,977,979,980,982,983,986,987,988,989,993,994,995,996,997,998,999,1001,1004,1006,1007,1008,1009,1010,1013,1014,1015,1016,1017,1018,1019,1020,1021,1022,1023 };
	const uint16_t g_unique_to_seed_12x10_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,34,36,37,39,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,94,95,97,98,99,100,101,102,103,104,105,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,128,129,130,131,132,134,135,136,137,138,139,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,161,165,167,168,169,170,171,172,174,175,176,177,178,179,180,181,182,183,184,185,188,190,191,193,194,195,196,198,199,200,201,202,203,204,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225,226,227,229,230,231,232,235,236,237,238,239,240,242,243,244,245,246,247,248,249,250,252,253,254,255,256,257,258,260,261,262,263,264,265,266,267,270,271,272,273,274,275,276,277,278,279,280,281,282,283,284,286,287,289,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,310,313,314,316,317,318,319,321,323,324,325,326,327,329,330,331,332,333,335,337,338,339,341,342,343,344,347,348,349,350,351,352,353,354,355,356,357,358,359,360,361,362,363,365,366,367,368,370,371,373,374,375,376,377,378,380,381,383,385,386,387,388,389,390,391,392,393,394,395,399,400,402,403,404,405,407,409,410,411,412,414,415,417,418,419,420,421,422,423,424,425,426,427,428,429,430,432,433,436,437,438,439,440,441,443,444,445,446,447,449,450,451,452,453,454,455,458,459,461,462,463,465,466,469,470,471,473,474,475,476,478,479,480,481,482,484,486,487,488,489,490,491,492,493,494,495,496,498,499,500,501,502,503,504,505,506,508,509,510,511,513,514,515,516,517,518,519,520,521,522,523,524,526,527,528,529,530,531,532,533,534,535,536,537,538,539,542,543,545,546,547,548,549,550,551,553,554,558,559,561,562,563,564,566,567,569,570,571,572,575,578,579,580,581,583,584,585,586,587,589,590,591,593,594,595,596,597,598,599,600,601,602,605,606,607,608,609,610,611,612,614,615,616,617,618,619,620,621,622,623,624,625,627,628,629,631,633,634,636,638,639,643,645,646,647,648,649,650,651,652,654,655,657,658,659,661,662,663,664,665,666,667,668,670,671,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,699,700,701,702,703,705,706,707,709,711,713,714,716,719,720,722,723,724,725,726,727,730,731,732,736,738,739,740,742,743,745,747,748,751,753,754,755,756,757,758,760,762,763,764,766,768,769,770,771,772,773,774,775,776,778,780,781,782,783,784,785,786,787,788,789,791,792,793,794,795,796,797,798,799,801,802,803,804,805,806,807,808,810,811,812,813,814,817,818,819,820,821,822,823,825,826,828,829,830,831,833,834,835,836,839,840,841,842,845,846,847,848,849,851,852,854,855,856,857,858,861,862,866,867,868,869,870,871,872,873,874,875,876,877,878,879,880,881,883,886,887,888,890,891,893,894,895,896,897,898,899,901,902,903,904,906,908,909,910,911,912,913,914,915,916,917,918,919,920,921,923,924,927,929,930,932,933,934,935,936,937,938,940,941,942,943,944,945,947,948,949,950,951,954,955,956,958,959,960,961,962,963,964,966,967,968,969,970,971,972,975,976,977,979,980,982,983,986,987,988,989,993,994,995,996,997,998,999,1001,1004,1006,1007,1008,1009,1010,1013,1014,1015,1016,1017,1018,1019,1020,1021,1022,1023 };
	const uint16_t g_unique_to_seed_12x12_p2[] = { 1,2,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,23,24,25,26,27,28,29,30,31,32,33,34,36,37,39,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,94,95,97,98,99,100,101,102,103,104,105,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,128,129,130,131,132,134,135,136,137,138,139,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,161,165,167,168,169,170,171,172,174,175,176,177,178,179,180,181,182,183,184,185,186,188,190,191,193,194,195,196,198,199,200,201,202,203,204,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225,226,227,229,230,231,232,235,236,237,238,239,240,242,243,244,245,246,247,248,249,250,252,253,254,255,256,257,258,260,261,262,263,264,265,266,267,269,270,271,272,273,274,275,276,277,278,279,280,281,282,283,284,286,287,289,290,291,292,293,294,295,296,298,299,300,302,303,304,305,306,307,309,310,313,314,316,317,318,319,321,323,324,325,326,327,329,330,331,332,333,335,337,338,339,340,341,342,343,344,347,348,349,350,351,352,353,354,355,356,357,358,359,360,361,362,363,365,366,367,368,370,371,373,374,375,376,377,378,380,381,382,383,384,385,386,387,388,389,390,391,392,393,394,395,396,399,400,402,403,404,405,407,409,410,411,412,414,415,417,418,419,420,421,422,423,424,425,426,427,428,429,430,432,433,436,437,438,439,440,441,443,444,445,446,447,449,450,451,452,453,454,455,456,458,459,461,462,463,465,466,469,470,471,473,474,475,476,478,479,480,481,482,484,486,487,488,489,490,491,492,493,494,495,496,498,499,500,501,502,503,504,505,506,508,509,510,511,513,514,515,516,517,518,519,520,521,522,523,524,526,527,528,529,530,531,532,533,534,535,536,537,538,539,542,543,545,546,547,548,549,550,551,553,554,557,558,559,561,562,563,564,566,567,569,570,571,572,575,576,578,579,580,581,583,584,585,586,587,589,590,591,593,594,595,596,597,598,599,600,601,602,605,606,607,608,609,610,611,612,614,615,616,617,618,619,620,621,622,623,624,625,627,628,629,631,633,634,636,638,639,640,643,644,645,646,647,648,649,650,651,652,654,655,657,658,659,660,661,662,663,664,665,666,667,668,670,671,672,673,674,675,681,683,684,685,686,687,688,690,691,692,693,694,695,696,697,699,700,701,702,703,705,706,707,709,711,713,714,716,717,719,720,721,722,723,724,725,726,727,730,731,732,736,738,739,740,742,743,745,747,748,751,753,754,755,756,757,758,760,762,763,764,766,768,769,770,771,772,773,774,775,776,778,780,781,782,783,784,785,786,787,788,789,791,792,793,794,795,796,797,798,799,800,801,802,803,804,805,806,807,808,810,811,812,813,814,815,817,818,819,820,821,822,823,825,826,828,829,830,831,833,834,835,836,837,839,840,841,842,844,845,846,847,848,849,851,852,854,855,856,857,858,861,862,863,866,867,868,869,870,871,872,873,874,875,876,877,878,879,880,881,883,886,887,888,890,891,893,894,895,896,897,898,899,901,902,903,904,906,908,909,910,911,912,913,914,915,916,917,918,919,920,921,923,924,927,929,930,932,933,934,935,936,937,938,940,941,942,943,944,945,947,948,949,950,951,954,955,956,958,959,960,961,962,963,964,966,967,968,969,970,971,972,975,976,977,979,980,982,983,986,987,988,989,993,994,995,996,997,998,999,1001,1004,1006,1007,1008,1009,1010,1013,1014,1015,1016,1017,1018,1019,1020,1021,1022,1023 };

	const uint16_t g_unique_to_seed_4x4_p3[] = { 0,3,8,11,14,15,17,26,29,30,31,32,33,36,38,43,44,47,49,51,55,56,57,59,67,70,74,76,79,81,82,88,89,90,100,104,108,110,111,117,122,126,127,132,133,134,135,139,147,150,151,152,156,157,163,166,167,168,171,175,176,179,181,182,183,186,189,192,199,203,205,207,210,214,216,230,236,247,249,250,252,254,260,262,263,266,272,273,276,291,292,294,297,302,309,310,313,314,318,319,324,327,328,330,331,335,337,346,355,356,357,358,363,365,368,378,381,384,386,388,390,391,392,397,398,401,410,411,417,419,427,431,437,439,440,446,451,455,457,458,459,460,462,464,467,468,471,472,474,475,477,479,483,487,488,493,495,496,497,502,503,504,511,512,516,518,519,523,525,530,532,538,543,544,546,547,549,550,551,553,554,562,567,568,570,571,578,579,581,582,588,589,590,593,594,600,601,606,611,613,623,624,625,630,637,638,645,646,648,650,651,658,659,662,666,669,670,678,683,686,688,691,694,696,699,700,701,703,704,707,713,715,717,719,722,724,725,727,730,731,735,738,739,745,750,751,758,759,760,766,775,776,779,783,784,785,786,787,788,798,799,802,804,805,807,808,809,812,821,822,823,825,827,831,835,837,838,842,844,845,846,848,853,854,858,859,860,866,884,888,892,894,898,902,906,907,915,918,922,923,925,927,931,932,937,938,940,943,945,953,955,958,959,963,971,974,977,979,989,990,998,1005,1006,1007,1011,1012,1015,1020,1023 };
	const uint16_t g_unique_to_seed_5x4_p3[] = { 0,3,7,8,11,12,14,15,17,18,26,29,30,31,32,33,34,36,38,39,43,44,47,49,51,55,56,57,59,62,63,67,70,74,76,79,81,82,88,89,90,91,100,103,104,108,110,111,117,122,123,126,127,132,133,134,135,136,139,144,147,150,151,152,156,157,158,163,166,167,168,171,173,175,176,179,181,182,183,186,189,192,199,203,205,207,210,214,216,222,230,236,246,247,249,250,252,254,259,260,262,263,266,269,272,273,274,275,276,291,292,293,294,297,302,306,309,310,311,313,314,315,318,319,324,327,328,330,331,335,337,346,355,356,357,358,359,363,365,368,377,378,381,384,386,388,390,391,392,394,397,398,401,407,410,411,417,419,427,430,431,437,439,440,446,451,455,457,458,459,460,462,464,467,468,470,471,472,474,475,477,478,479,483,485,487,488,493,495,496,497,501,502,503,504,506,508,510,511,512,515,516,518,519,521,523,524,525,530,532,538,541,543,544,546,547,549,550,551,552,553,554,562,567,568,570,571,577,578,579,581,582,588,589,590,593,594,595,600,601,603,606,609,611,613,623,624,625,630,632,637,638,639,645,646,648,650,651,654,658,659,662,666,669,670,678,679,683,685,686,688,691,694,696,699,700,701,703,704,707,713,715,717,719,722,724,725,727,730,731,732,735,738,739,742,745,746,749,750,751,758,759,760,766,769,773,775,776,779,783,784,785,786,787,788,791,793,798,799,802,804,805,806,807,808,809,812,813,821,822,823,825,827,831,835,837,838,839,842,844,845,846,848,853,854,858,859,860,866,873,876,877,884,887,888,892,894,898,902,906,907,914,915,918,919,922,923,925,927,931,932,937,938,940,943,944,945,951,953,955,958,959,963,971,972,974,977,979,982,983,989,990,991,998,999,1005,1006,1007,1010,1011,1012,1015,1020,1022,1023 };
	const uint16_t g_unique_to_seed_5x5_p3[] = { 0,3,7,8,10,11,12,14,15,17,18,26,27,29,30,31,32,33,34,36,38,39,43,44,47,48,49,50,51,55,56,57,59,60,61,62,63,67,70,72,74,76,79,81,82,88,89,90,91,94,100,103,104,106,108,110,111,115,117,122,123,126,127,128,130,132,133,134,135,136,139,144,147,150,151,152,156,157,158,162,163,166,167,168,169,171,173,175,176,179,181,182,183,186,189,192,199,203,205,207,209,210,214,216,220,222,227,230,235,236,246,247,249,250,252,254,257,259,260,262,263,266,269,272,273,274,275,276,279,282,291,292,293,294,295,297,302,306,309,310,311,313,314,315,318,319,324,326,327,328,330,331,335,337,342,345,346,353,355,356,357,358,359,363,364,365,368,371,374,377,378,381,384,386,387,388,390,391,392,394,397,398,399,401,407,410,411,417,419,427,430,431,437,438,439,440,443,446,451,455,456,457,458,459,460,462,463,464,466,467,468,470,471,472,474,475,477,478,479,480,482,483,485,487,488,493,495,496,497,501,502,503,504,506,508,510,511,512,515,516,518,519,521,522,523,524,525,530,532,538,539,541,543,544,546,547,549,550,551,552,553,554,555,562,567,568,570,571,577,578,579,581,582,586,588,589,590,593,594,595,600,601,602,603,606,609,610,611,613,618,623,624,625,626,630,632,637,638,639,645,646,648,650,651,654,658,659,662,666,667,668,669,670,671,678,679,683,685,686,687,688,691,694,696,698,699,700,701,703,704,707,708,713,715,717,719,722,724,725,727,730,731,732,734,735,738,739,742,745,746,747,748,749,750,751,753,758,759,760,764,766,767,769,771,773,775,776,779,780,781,783,784,785,786,787,788,791,793,794,798,799,800,802,804,805,806,807,808,809,811,812,813,821,822,823,825,827,831,835,837,838,839,840,842,843,844,845,846,847,848,850,852,853,854,858,859,860,866,869,873,874,876,877,881,884,886,887,888,892,894,897,898,902,905,906,907,914,915,918,919,920,922,923,925,927,931,932,937,938,940,943,944,945,951,953,954,955,958,959,963,971,972,973,974,977,978,979,982,983,989,990,991,992,998,999,1004,1005,1006,1007,1010,1011,1012,1015,1020,1022,1023 };
	const uint16_t g_unique_to_seed_6x5_p3[] = { 0,3,7,8,10,11,12,14,15,17,18,21,23,26,27,29,30,31,32,33,34,35,36,38,39,42,43,44,47,48,49,50,51,55,56,57,59,60,61,62,63,67,70,72,74,76,79,81,82,88,89,90,91,94,100,102,103,104,106,108,110,111,114,115,117,120,122,123,126,127,128,130,132,133,134,135,136,139,140,144,147,150,151,152,153,156,157,158,162,163,166,167,168,169,171,173,175,176,179,181,182,183,186,189,192,198,199,200,203,205,207,209,210,214,216,220,222,227,230,231,235,236,245,246,247,249,250,252,254,257,259,260,262,263,266,269,272,273,274,275,276,279,281,282,288,291,292,293,294,295,297,300,302,306,309,310,311,313,314,315,318,319,324,326,327,328,330,331,335,337,342,345,346,348,353,355,356,357,358,359,363,364,365,368,371,372,374,377,378,379,381,384,386,387,388,390,391,392,394,395,397,398,399,401,407,410,411,412,413,417,419,427,430,431,437,438,439,440,443,446,450,451,455,456,457,458,459,460,461,462,463,464,465,466,467,468,470,471,472,474,475,477,478,479,480,482,483,485,487,488,493,495,496,497,500,501,502,503,504,505,506,508,510,511,512,513,515,516,518,519,521,522,523,524,525,527,530,532,538,539,541,543,544,546,547,549,550,551,552,553,554,555,557,558,562,566,567,568,570,571,577,578,579,580,581,582,584,586,588,589,590,593,594,595,600,601,602,603,606,609,610,611,613,614,618,623,624,625,626,630,632,637,638,639,644,645,646,648,650,651,654,658,659,662,666,667,668,669,670,671,678,679,683,685,686,687,688,689,691,694,696,698,699,700,701,703,704,707,708,711,713,715,717,719,722,724,725,727,730,731,732,734,735,738,739,742,743,745,746,747,748,749,750,751,753,758,759,760,764,766,767,769,771,773,775,776,779,780,781,783,784,785,786,787,788,791,793,794,798,799,800,802,804,805,806,807,808,809,810,811,812,813,821,822,823,824,825,827,831,835,836,837,838,839,840,841,842,843,844,845,846,847,848,850,852,853,854,858,859,860,866,869,873,874,876,877,881,884,886,887,888,892,894,897,898,900,902,905,906,907,914,915,918,919,920,922,923,925,927,931,932,937,938,940,943,944,945,951,953,954,955,957,958,959,963,967,971,972,973,974,977,978,979,982,983,986,989,990,991,992,998,999,1003,1004,1005,1006,1007,1010,1011,1012,1015,1020,1022,1023 };

	const uint16_t g_unique_to_seed_6x6_p3[] = { 0,8,11,14,15,17,18,19,26,31,34,35,36,38,44,47,48,49,51,56,59,61,70,74,76,82,88,90,96,100,103,104,108,110,111,117,122,123,126,127,132,133,135,139,147,150,151,152,156,157,163,166,168,171,175,176,179,181,182,183,186,189,192,199,203,205,207,210,214,216,222,247,249,250,252,254,260,261,262,263,266,272,273,275,276,288,291,292,293,294,297,302,309,310,313,314,318,327,328,331,335,337,346,356,357,358,363,365,368,378,381,384,386,390,391,392,396,397,398,399,401,410,411,419,427,430,431,437,439,440,451,455,457,458,459,460,462,468,470,471,472,474,475,477,479,482,483,488,493,495,496,502,503,504,507,510,511,512,515,516,518,519,522,523,525,526,527,538,543,544,546,547,549,550,552,553,554,562,570,578,579,581,582,588,589,590,593,595,600,606,611,613,618,623,625,632,637,638,645,646,650,651,658,659,662,666,667,669,670,678,679,685,686,687,688,691,694,696,698,699,700,701,703,704,707,713,714,715,717,719,722,724,727,730,731,734,738,739,743,747,748,750,751,753,758,760,764,766,769,775,776,783,784,785,787,791,793,798,799,802,804,805,806,807,808,809,810,813,822,823,825,831,835,837,838,839,840,842,845,846,848,853,854,858,859,860,866,874,882,884,887,888,892,894,898,902,907,914,915,918,919,922,923,925,927,931,932,937,938,940,943,944,945,953,955,958,959,963,966,971,974,979,990,991,998,999,1007,1010,1011,1012,1015,1020,1023 };
	const uint16_t g_unique_to_seed_8x5_p3[] = { 0,3,8,11,14,15,17,18,19,23,26,27,29,31,33,34,35,36,38,43,44,47,48,49,51,55,56,59,61,67,70,76,79,81,82,88,89,90,96,100,103,104,108,110,111,117,122,123,126,127,132,133,134,135,139,147,150,151,152,156,157,163,166,167,168,171,173,175,176,179,181,182,183,186,189,192,199,203,205,207,210,214,216,227,230,247,249,250,254,260,261,262,263,266,272,273,275,276,279,288,291,292,293,294,297,302,307,309,310,313,314,315,318,319,327,328,331,335,337,346,355,356,357,358,359,363,365,377,378,381,384,386,390,391,392,394,396,397,398,399,401,407,410,411,419,424,427,430,431,437,439,440,450,451,455,457,458,459,460,462,464,467,468,470,471,472,474,475,477,478,479,482,483,487,488,493,495,496,502,503,504,507,508,511,512,515,516,518,519,522,523,524,526,527,538,543,544,547,549,550,552,553,554,557,562,568,570,578,579,581,582,588,589,590,593,595,600,602,603,606,609,611,613,614,624,625,632,637,638,639,645,646,650,651,658,659,662,666,667,669,670,678,679,685,686,687,688,689,691,694,696,699,700,701,703,704,707,712,713,715,717,719,722,724,727,730,731,734,738,739,743,745,747,750,751,758,759,760,763,764,766,769,771,775,776,779,781,783,784,785,787,791,793,798,799,802,804,805,806,807,809,810,812,813,822,823,825,831,835,837,838,840,842,844,845,846,848,853,854,858,859,860,866,873,876,882,884,887,888,892,894,895,898,902,906,907,914,915,918,919,922,923,925,927,931,932,937,938,940,943,944,945,947,951,953,955,958,959,963,966,971,974,977,979,983,989,990,991,998,999,1005,1007,1010,1011,1012,1015,1023 };
	const uint16_t g_unique_to_seed_8x6_p3[] = { 0,3,8,11,14,15,17,18,19,23,26,27,29,31,33,34,35,36,38,43,44,47,48,49,51,55,56,59,61,67,70,74,76,79,81,82,88,89,90,96,100,103,104,108,110,111,117,122,123,126,127,131,132,133,134,135,139,147,150,151,152,156,157,163,166,167,168,171,173,175,176,179,181,182,183,186,189,192,199,203,205,207,210,214,216,222,227,230,236,247,249,250,252,254,260,261,262,263,266,272,273,275,276,279,288,291,292,293,294,297,302,307,309,310,313,314,315,318,319,324,327,328,331,335,337,338,346,355,356,357,358,359,363,365,368,377,378,381,384,386,390,391,392,394,396,397,398,399,401,407,410,411,419,424,427,430,431,437,439,440,450,451,455,457,458,459,460,462,464,467,468,470,471,472,474,475,477,478,479,482,483,485,487,488,493,495,496,502,503,504,507,508,510,511,512,515,516,518,519,522,523,524,525,526,527,538,541,543,544,546,547,549,550,552,553,554,557,562,566,567,568,570,578,579,581,582,588,589,590,593,595,600,601,602,603,606,609,611,613,614,618,623,624,625,632,637,638,639,645,646,650,651,658,659,662,666,667,669,670,678,679,685,686,687,688,689,691,694,696,698,699,700,701,703,704,707,708,712,713,714,715,717,719,722,724,725,727,730,731,732,734,738,739,743,745,747,748,750,751,753,758,759,760,763,764,766,769,771,775,776,779,781,783,784,785,786,787,791,793,798,799,802,804,805,806,807,808,809,810,812,813,822,823,825,831,835,837,838,839,840,842,844,845,846,848,850,853,854,858,859,860,866,873,874,876,882,884,887,888,892,894,895,898,900,902,906,907,914,915,918,919,922,923,925,927,931,932,937,938,940,943,944,945,947,951,953,955,958,959,963,966,971,974,977,979,983,989,990,991,998,999,1005,1007,1010,1011,1012,1015,1020,1022,1023 };
	const uint16_t g_unique_to_seed_10x5_p3[] = { 0,3,7,8,11,14,15,17,18,19,23,26,27,29,31,33,34,35,36,38,43,44,47,48,49,51,55,56,59,61,62,67,70,72,76,79,81,82,88,89,90,91,95,96,100,103,104,108,110,111,114,117,122,123,126,127,131,132,133,134,135,139,140,147,150,151,152,156,157,158,163,166,167,168,171,173,175,176,179,181,182,183,186,189,192,199,203,205,207,210,213,214,216,227,230,245,247,249,250,254,259,260,261,262,263,266,269,272,273,274,275,276,279,281,288,291,292,293,294,295,297,302,307,309,310,313,314,315,318,319,327,328,331,335,337,346,355,356,357,358,359,363,365,377,378,381,384,386,390,391,392,394,396,397,398,399,401,407,410,411,412,413,419,424,427,430,431,437,439,440,450,451,455,457,458,459,460,462,464,467,468,470,471,472,474,475,477,478,479,482,483,487,488,493,495,496,500,501,502,503,504,506,507,508,510,511,512,515,516,518,519,521,522,523,524,526,527,530,538,541,543,544,547,549,550,552,553,554,555,557,562,565,568,570,577,578,579,581,582,588,589,590,593,595,600,601,602,603,606,609,611,613,614,618,624,625,632,637,638,639,645,646,650,651,654,658,659,662,666,667,669,670,678,679,685,686,687,688,689,691,694,695,696,698,699,700,701,703,704,707,712,713,715,717,719,722,724,725,727,730,731,732,734,738,739,742,743,745,747,749,750,751,758,759,760,763,764,765,766,769,771,773,775,776,779,781,783,784,785,786,787,791,793,798,799,802,804,805,806,807,809,810,812,813,821,822,823,825,827,831,835,836,837,838,839,840,841,842,844,845,846,848,853,854,858,859,860,866,869,873,876,877,882,884,887,888,891,892,894,895,898,900,902,905,906,907,909,914,915,918,919,922,923,925,927,931,932,937,938,939,940,943,944,945,947,951,953,954,955,957,958,959,961,963,966,967,971,974,975,977,978,979,983,989,990,991,993,998,999,1005,1007,1010,1011,1012,1015,1023 };
	
	const uint16_t g_unique_to_seed_10x6_p3[] = { 0,3,7,8,11,12,14,15,17,18,19,23,26,27,29,31,33,34,35,36,38,43,44,47,48,49,51,55,56,59,61,62,67,70,72,74,76,79,81,82,88,89,90,91,95,96,100,103,104,108,110,111,114,117,122,123,126,127,131,132,133,134,135,139,140,147,150,151,152,156,157,158,163,166,167,168,171,173,175,176,179,181,182,183,186,189,192,199,203,205,207,210,213,214,216,222,227,230,236,245,246,247,249,250,252,254,259,260,261,262,263,266,269,272,273,274,275,276,279,281,288,291,292,293,294,295,297,302,306,307,309,310,311,313,314,315,318,319,324,327,328,330,331,335,337,338,346,355,356,357,358,359,363,364,365,368,377,378,381,384,386,390,391,392,394,396,397,398,399,401,407,410,411,412,413,419,424,427,430,431,437,439,440,450,451,455,457,458,459,460,462,464,467,468,470,471,472,474,475,477,478,479,482,483,485,487,488,493,495,496,500,501,502,503,504,506,507,508,510,511,512,515,516,518,519,521,522,523,524,525,526,527,530,538,539,541,543,544,546,547,549,550,552,553,554,555,557,562,565,566,567,568,570,577,578,579,581,582,588,589,590,593,595,600,601,602,603,606,609,611,613,614,618,623,624,625,632,637,638,639,645,646,648,650,651,654,658,659,662,666,667,669,670,678,679,685,686,687,688,689,691,694,695,696,698,699,700,701,703,704,707,708,712,713,714,715,717,719,722,724,725,727,730,731,732,734,735,738,739,742,743,745,747,748,749,750,751,753,758,759,760,763,764,765,766,769,771,773,775,776,779,781,783,784,785,786,787,791,793,798,799,802,804,805,806,807,808,809,810,812,813,821,822,823,825,827,831,835,836,837,838,839,840,841,842,844,845,846,848,850,853,854,858,859,860,866,869,873,874,876,877,882,884,887,888,891,892,894,895,898,900,902,905,906,907,909,914,915,918,919,922,923,925,927,931,932,937,938,939,940,943,944,945,947,951,953,954,955,957,958,959,961,963,966,967,971,974,975,977,978,979,982,983,989,990,991,993,998,999,1005,1007,1010,1011,1012,1015,1020,1022,1023 };
	const uint16_t g_unique_to_seed_8x8_p3[] = { 0,3,7,8,11,12,14,15,17,18,19,23,26,27,29,30,31,32,33,34,35,36,38,39,43,44,47,48,49,50,51,55,56,57,59,60,61,63,67,70,72,74,76,79,81,82,88,89,90,96,100,103,104,106,108,110,111,117,122,123,126,127,131,132,133,134,135,136,139,144,147,150,151,152,156,157,158,163,166,167,168,171,173,175,176,178,179,181,182,183,186,189,192,199,203,205,207,210,214,216,222,227,230,235,236,246,247,249,250,252,254,260,261,262,263,266,269,272,273,275,276,279,288,291,292,293,294,295,297,302,306,307,309,310,311,313,314,315,318,319,324,327,328,330,331,335,337,338,342,345,346,355,356,357,358,359,363,365,368,371,377,378,381,384,386,388,390,391,392,394,396,397,398,399,401,407,410,411,417,419,424,427,430,431,437,439,440,446,450,451,455,457,458,459,460,462,464,466,467,468,470,471,472,474,475,477,478,479,480,482,483,485,487,488,493,495,496,497,502,503,504,507,508,510,511,512,515,516,518,519,521,522,523,524,525,526,527,530,532,538,539,541,543,544,546,547,549,550,551,552,553,554,557,562,566,567,568,570,571,577,578,579,581,582,586,588,589,590,592,593,594,595,600,601,602,603,606,609,610,611,613,614,618,623,624,625,630,632,637,638,639,645,646,648,650,651,658,659,662,666,667,669,670,671,678,679,683,685,686,687,688,689,691,694,696,698,699,700,701,703,704,707,708,712,713,714,715,717,719,722,724,725,727,730,731,732,734,735,738,739,743,745,746,747,748,750,751,753,758,759,760,763,764,766,767,769,771,773,775,776,779,780,781,783,784,785,786,787,788,791,793,794,798,799,802,804,805,806,807,808,809,810,811,812,813,821,822,823,825,827,831,835,837,838,839,840,842,844,845,846,847,848,850,852,853,854,858,859,860,866,873,874,876,877,882,884,886,887,888,892,894,895,897,898,900,902,906,907,914,915,918,919,920,922,923,925,927,931,932,937,938,940,943,944,945,947,951,953,954,955,958,959,963,966,971,972,974,977,979,982,983,989,990,991,998,999,1005,1006,1007,1010,1011,1012,1015,1020,1022,1023 };
	const uint16_t g_unique_to_seed_10x8_p3[] = { 0,3,7,8,11,12,14,15,17,18,19,23,26,27,29,30,31,32,33,34,35,36,38,39,43,44,47,48,49,50,51,55,56,57,59,60,61,62,63,67,70,72,74,76,79,81,82,88,89,90,91,94,95,96,100,103,104,106,108,110,111,114,115,117,122,123,126,127,131,132,133,134,135,136,139,140,144,147,150,151,152,153,156,157,158,163,166,167,168,171,173,175,176,178,179,181,182,183,186,189,192,198,199,203,205,207,210,213,214,216,220,222,227,230,235,236,245,246,247,249,250,252,254,259,260,261,262,263,266,269,272,273,274,275,276,279,281,288,291,292,293,294,295,297,302,306,307,309,310,311,313,314,315,318,319,324,327,328,330,331,335,337,338,342,345,346,355,356,357,358,359,363,364,365,368,371,374,377,378,379,381,384,386,387,388,390,391,392,394,395,396,397,398,399,401,407,410,411,412,413,417,419,424,427,430,431,437,438,439,440,443,446,450,451,455,457,458,459,460,462,464,466,467,468,470,471,472,474,475,477,478,479,480,482,483,485,487,488,493,495,496,497,500,501,502,503,504,505,506,507,508,510,511,512,515,516,518,519,521,522,523,524,525,526,527,530,532,538,539,541,543,544,546,547,549,550,551,552,553,554,555,557,562,565,566,567,568,570,571,577,578,579,581,582,586,588,589,590,592,593,594,595,600,601,602,603,606,609,610,611,613,614,618,623,624,625,630,632,637,638,639,644,645,646,648,650,651,654,658,659,662,666,667,669,670,671,678,679,683,685,686,687,688,689,691,694,695,696,698,699,700,701,703,704,707,708,712,713,714,715,717,719,722,724,725,727,730,731,732,734,735,738,739,742,743,745,746,747,748,749,750,751,753,758,759,760,763,764,765,766,767,769,771,773,775,776,779,780,781,783,784,785,786,787,788,791,793,794,798,799,800,802,804,805,806,807,808,809,810,811,812,813,821,822,823,825,827,831,835,836,837,838,839,840,841,842,844,845,846,847,848,850,852,853,854,858,859,860,866,869,873,874,876,877,882,884,886,887,888,891,892,894,895,897,898,900,902,905,906,907,909,914,915,918,919,920,922,923,925,927,931,932,937,938,939,940,943,944,945,947,951,953,954,955,957,958,959,961,963,966,967,971,972,973,974,975,977,978,979,982,983,986,989,990,991,993,998,999,1005,1006,1007,1010,1011,1012,1015,1020,1022,1023};
	const uint16_t g_unique_to_seed_10x10_p3[] = { 0,3,7,8,10,11,12,14,15,17,18,19,23,26,27,29,30,31,32,33,34,35,36,38,39,40,43,44,47,48,49,50,51,55,56,57,59,60,61,62,63,67,70,72,74,75,76,79,81,82,88,89,90,91,94,95,96,100,103,104,106,108,110,111,114,115,117,120,122,123,126,127,128,130,131,132,133,134,135,136,139,140,144,147,150,151,152,153,156,157,158,162,163,166,167,168,169,171,173,175,176,178,179,181,182,183,186,189,192,198,199,200,203,205,207,209,210,213,214,216,218,220,222,227,230,235,236,238,242,245,246,247,249,250,252,254,257,259,260,261,262,263,266,269,272,273,274,275,276,279,281,282,288,291,292,293,294,295,297,302,306,307,308,309,310,311,313,314,315,318,319,324,326,327,328,330,331,335,337,338,342,345,346,347,350,353,355,356,357,358,359,363,364,365,368,371,372,374,377,378,379,381,384,386,387,388,390,391,392,394,395,396,397,398,399,401,407,408,410,411,412,413,417,419,424,427,430,431,435,437,438,439,440,443,446,450,451,455,456,457,458,459,460,462,463,464,466,467,468,470,471,472,474,475,477,478,479,480,482,483,485,487,488,493,495,496,497,500,501,502,503,504,505,506,507,508,510,511,512,513,515,516,518,519,521,522,523,524,525,526,527,530,532,538,539,541,543,544,546,547,549,550,551,552,553,554,555,557,562,565,566,567,568,570,571,577,578,579,580,581,582,586,588,589,590,592,593,594,595,600,601,602,603,606,609,610,611,613,614,618,623,624,625,626,630,632,634,637,638,639,644,645,646,648,650,651,654,658,659,662,666,667,668,669,670,671,678,679,683,685,686,687,688,689,691,694,695,696,698,699,700,701,703,704,707,708,712,713,714,715,717,719,722,724,725,727,730,731,732,734,735,738,739,742,743,745,746,747,748,749,750,751,753,758,759,760,763,764,765,766,767,769,771,773,775,776,779,780,781,783,784,785,786,787,788,789,790,791,793,794,798,799,800,802,804,805,806,807,808,809,810,811,812,813,821,822,823,825,827,831,835,836,837,838,839,840,841,842,843,844,845,846,847,848,850,852,853,854,858,859,860,866,869,873,874,876,877,881,882,884,886,887,888,891,892,894,895,897,898,900,902,905,906,907,909,914,915,918,919,920,922,923,925,927,931,932,937,938,939,940,943,944,945,947,951,952,953,954,955,957,958,959,961,963,966,967,971,972,973,974,975,977,978,979,980,982,983,986,989,990,991,992,993,998,999,1003,1004,1005,1006,1007,1010,1011,1012,1014,1015,1020,1022,1023 };
	
	const uint16_t g_unique_to_seed_12x10_p3[] = { 0,3,7,8,10,11,12,14,15,16,17,18,19,21,23,26,27,29,30,31,32,33,34,35,36,38,39,40,42,43,44,45,47,48,49,50,51,55,56,57,59,60,61,62,63,67,70,72,74,75,76,79,81,82,88,89,90,91,94,95,96,100,102,103,104,106,108,110,111,114,115,117,120,122,123,126,127,128,129,130,131,132,133,134,135,136,139,140,144,147,150,151,152,153,156,157,158,161,162,163,166,167,168,169,171,173,175,176,178,179,181,182,183,185,186,189,192,195,198,199,200,203,205,207,209,210,213,214,216,218,220,222,227,230,231,235,236,238,242,245,246,247,249,250,251,252,254,257,259,260,261,262,263,266,269,272,273,274,275,276,279,281,282,283,288,291,292,293,294,295,297,300,302,306,307,308,309,310,311,313,314,315,318,319,324,326,327,328,330,331,335,337,338,342,345,346,347,348,350,353,355,356,357,358,359,363,364,365,368,371,372,374,377,378,379,381,384,386,387,388,390,391,392,394,395,396,397,398,399,401,407,408,410,411,412,413,415,417,419,424,427,430,431,435,437,438,439,440,443,446,450,451,455,456,457,458,459,460,461,462,463,464,465,466,467,468,470,471,472,474,475,477,478,479,480,482,483,485,487,488,493,495,496,497,500,501,502,503,504,505,506,507,508,510,511,512,513,515,516,518,519,521,522,523,524,525,526,527,530,532,538,539,541,543,544,546,547,549,550,551,552,553,554,555,557,558,562,563,565,566,567,568,570,571,577,578,579,580,581,582,584,586,588,589,590,592,593,594,595,600,601,602,603,604,606,609,610,611,613,614,618,623,624,625,626,630,632,634,637,638,639,643,644,645,646,648,650,651,654,658,659,662,666,667,668,669,670,671,673,678,679,683,685,686,687,688,689,691,694,695,696,698,699,700,701,703,704,707,708,711,712,713,714,715,717,719,722,724,725,727,730,731,732,734,735,738,739,742,743,745,746,747,748,749,750,751,753,758,759,760,763,764,765,766,767,769,771,773,775,776,779,780,781,783,784,785,786,787,788,789,790,791,793,794,798,799,800,802,804,805,806,807,808,809,810,811,812,813,821,822,823,824,825,827,828,831,835,836,837,838,839,840,841,842,843,844,845,846,847,848,850,852,853,854,858,859,860,866,869,873,874,876,877,881,882,884,886,887,888,891,892,894,895,897,898,900,902,905,906,907,909,914,915,918,919,920,922,923,925,927,931,932,937,938,939,940,943,944,945,947,951,952,953,954,955,957,958,959,961,963,966,967,971,972,973,974,975,977,978,979,980,982,983,986,989,990,991,992,993,995,998,999,1002,1003,1004,1005,1006,1007,1010,1011,1012,1014,1015,1020,1021,1022,1023 };
	const uint16_t g_unique_to_seed_12x12_p3[] = { 0,3,4,7,8,10,11,12,14,15,16,17,18,19,21,23,26,27,29,30,31,32,33,34,35,36,38,39,40,42,43,44,45,47,48,49,50,51,53,55,56,57,58,59,60,61,62,63,67,70,72,74,75,76,79,81,82,83,88,89,90,91,94,95,96,100,102,103,104,106,108,110,111,114,115,117,120,122,123,126,127,128,129,130,131,132,133,134,135,136,138,139,140,144,147,150,151,152,153,156,157,158,159,160,161,162,163,166,167,168,169,171,173,175,176,177,178,179,181,182,183,185,186,189,192,195,196,198,199,200,203,205,207,208,209,210,213,214,216,218,220,222,227,230,231,235,236,238,242,245,246,247,249,250,251,252,254,257,259,260,261,262,263,266,269,272,273,274,275,276,279,281,282,283,288,291,292,293,294,295,297,300,302,306,307,308,309,310,311,313,314,315,318,319,324,326,327,328,330,331,335,337,338,342,345,346,347,348,350,353,355,356,357,358,359,363,364,365,368,371,372,374,377,378,379,381,384,386,387,388,390,391,392,394,395,396,397,398,399,401,407,408,410,411,412,413,415,417,419,424,426,427,430,431,432,435,437,438,439,440,443,444,446,450,451,455,456,457,458,459,460,461,462,463,464,465,466,467,468,470,471,472,474,475,477,478,479,480,482,483,485,487,488,493,495,496,497,500,501,502,503,504,505,506,507,508,510,511,512,513,515,516,518,519,521,522,523,524,525,526,527,530,532,535,538,539,540,541,543,544,546,547,549,550,551,552,553,554,555,557,558,562,563,565,566,567,568,569,570,571,577,578,579,580,581,582,584,586,588,589,590,592,593,594,595,600,601,602,603,604,606,609,610,611,613,614,618,623,624,625,626,628,630,631,632,634,636,637,638,639,640,643,644,645,646,648,650,651,654,658,659,662,666,667,668,669,670,671,673,678,679,683,685,686,687,688,689,691,694,695,696,698,699,700,701,703,704,707,708,711,712,713,714,715,717,719,722,724,725,727,730,731,732,734,735,738,739,742,743,745,746,747,748,749,750,751,753,758,759,760,763,764,765,766,767,768,769,771,773,774,775,776,778,779,780,781,783,784,785,786,787,788,789,790,791,793,794,798,799,800,802,804,805,806,807,808,809,810,811,812,813,821,822,823,824,825,827,828,831,835,836,837,838,839,840,841,842,843,844,845,846,847,848,850,852,853,854,858,859,860,863,866,869,873,874,876,877,881,882,884,886,887,888,891,892,894,895,897,898,900,902,905,906,907,909,911,912,914,915,918,919,920,922,923,925,927,929,930,931,932,937,938,939,940,943,944,945,947,951,952,953,954,955,957,958,959,961,963,966,967,971,972,973,974,975,977,978,979,980,982,983,986,989,990,991,992,993,995,998,999,1000,1002,1003,1004,1005,1006,1007,1010,1011,1012,1014,1015,1020,1021,1022,1023 };

	const uint16_t* g_unique_index_to_astc_part_seed[2][astc_helpers::NUM_ASTC_BLOCK_SIZES] = // [num_subsets-1][astc_block_size_index]
	{
		{
			g_unique_to_seed_4x4_p2, g_unique_to_seed_5x4_p2, g_unique_to_seed_5x5_p2, g_unique_to_seed_6x5_p2,
			g_unique_to_seed_6x6_p2, g_unique_to_seed_8x5_p2, g_unique_to_seed_8x6_p2, g_unique_to_seed_10x5_p2,
			g_unique_to_seed_10x6_p2, g_unique_to_seed_8x8_p2, g_unique_to_seed_10x8_p2, g_unique_to_seed_10x10_p2,
			g_unique_to_seed_12x10_p2, g_unique_to_seed_12x12_p2
		},
		{
			g_unique_to_seed_4x4_p3, g_unique_to_seed_5x4_p3, g_unique_to_seed_5x5_p3, g_unique_to_seed_6x5_p3,
			g_unique_to_seed_6x6_p3, g_unique_to_seed_8x5_p3, g_unique_to_seed_8x6_p3, g_unique_to_seed_10x5_p3,
			g_unique_to_seed_10x6_p3, g_unique_to_seed_8x8_p3, g_unique_to_seed_10x8_p3, g_unique_to_seed_10x10_p3,
			g_unique_to_seed_12x10_p3, g_unique_to_seed_12x12_p3
		}
	};

	uint16_t unique_pat_index_to_part_seed(uint32_t astc_block_size_index, uint32_t num_parts, uint32_t unique_pat_index)
	{
		assert(astc_block_size_index < astc_helpers::NUM_ASTC_BLOCK_SIZES);
		assert((num_parts >= 2) && (num_parts <= 3));
		assert(unique_pat_index < get_total_unique_patterns(astc_block_size_index, num_parts));
				
		return g_unique_index_to_astc_part_seed[num_parts - 2][astc_block_size_index][unique_pat_index];
	}

	static bool zstd_decompress(const void *pComp_data, size_t comp_size, basisu::uint8_vec &uncomp_data)
	{
		if (!comp_size)
		{
			uncomp_data.resize(0);
			return true;
		}

#if BASISD_SUPPORT_KTX2_ZSTD
		const uint64_t decomp_size = ZSTD_getFrameContentSize(pComp_data, comp_size);

		if ((decomp_size == ZSTD_CONTENTSIZE_UNKNOWN) || (decomp_size == ZSTD_CONTENTSIZE_ERROR))
		{
			BASISU_DEVEL_ERROR("zstd_decompress: ZSTD_getFrameContentSize failed\n");
			return false;
		}

		// sanity check, not UINT32_MAX purposely, even INT_MAX is too high
		if (decomp_size > (uint64_t)INT32_MAX)
		{
			BASISU_DEVEL_ERROR("zstd_decompress: decompressed size too large\n");
			return false;
		}

		if (!uncomp_data.try_resize((size_t)decomp_size))
		{
			BASISU_DEVEL_ERROR("zstd_decompress: Out of memory\n");
			return false;
		}

		if (!decomp_size)
			return true;

		const size_t actual_uncomp_size = ZSTD_decompress(uncomp_data.data(), uncomp_data.size(), pComp_data, comp_size);
		if (ZSTD_isError(actual_uncomp_size))
		{
			BASISU_DEVEL_ERROR("zstd_decompress: Zstd decompression failed, file is invalid or corrupted\n");
			return false;
		}

		assert(actual_uncomp_size == decomp_size);
		uncomp_data.resize(actual_uncomp_size);

		return true;
#else
		BASISU_NOTE_UNUSED(pComp_data);
		BASISU_DEVEL_ERROR("zstd_decompress: file uses ZStd compression, but ZStd support disabled (see BASISD_SUPPORT_KTX2_ZSTD) \n");
		return false;
#endif
	}

	static bool zstd_decompress_and_advance(const uint8_t* &pComp_data, size_t comp_size, basisu::uint8_vec& uncomp_data, simplified_bitwise_decoder& dec)
	{
		if (!zstd_decompress(pComp_data, comp_size, uncomp_data))
			return false;
		pComp_data += comp_size;
		dec.init(uncomp_data.data(), uncomp_data.size());
		return true;
	}

	bool xuastc_ldr_decompress_image_full_zstd(
		const uint8_t* pComp_data_all, size_t comp_data_size_all,
		uint32_t& astc_block_width, uint32_t& astc_block_height,
		uint32_t& actual_width, uint32_t& actual_height, bool& has_alpha, bool& uses_srgb_astc_decode_mode,
		bool debug_output,
		xuastc_decomp_image_init_callback_ptr pInit_callback, void* pInit_callback_data,
		xuastc_decomp_image_block_callback_ptr pBlock_callback, void* pBlock_callback_data)
	{
		if (comp_data_size_all < sizeof(xuastc_ldr_full_zstd_header))
		{
			BASISU_DEVEL_ERROR("Compressed file is too small\n");
			return false;
		}

		const xuastc_ldr_full_zstd_header* pHdr = (const xuastc_ldr_full_zstd_header*)pComp_data_all;

		if ((!pHdr->m_raw_bits_len) || (!pHdr->m_mode_bytes_len))
		{
			BASISU_DEVEL_ERROR("Compressed file is too small\n");
			return false;
		}

		const uint64_t total_comp_size = (uint64_t)((uint32_t)pHdr->m_raw_bits_len) +
			pHdr->m_mode_bytes_len + pHdr->m_solid_dpcm_bytes_len + pHdr->m_endpoint_dpcm_reuse_indices_len + pHdr->m_use_bc_bits_len + 
			pHdr->m_endpoint_dpcm_3bit_len + pHdr->m_endpoint_dpcm_4bit_len + pHdr->m_endpoint_dpcm_5bit_len + pHdr->m_endpoint_dpcm_6bit_len + pHdr->m_endpoint_dpcm_7bit_len + pHdr->m_endpoint_dpcm_8bit_len +
			pHdr->m_mean0_bits_len + pHdr->m_mean1_bytes_len +
			pHdr->m_run_bytes_len + pHdr->m_coeff_bytes_len + pHdr->m_sign_bits_len +
			pHdr->m_weight2_bits_len + pHdr->m_weight3_bits_len + pHdr->m_weight4_bits_len + pHdr->m_weight8_bytes_len;

		if (comp_data_size_all < (sizeof(xuastc_ldr_full_zstd_header) + total_comp_size))
		{
			BASISU_DEVEL_ERROR("Compressed file is too small\n");
			return false;
		}

		bitwise_decoder raw_bits;
		simplified_bitwise_decoder comp_mode_dec, solid_dpcm_dec, endpoint_dpcm_reuse_indices_dec, use_bc_bits_dec;
		simplified_bitwise_decoder endpoint_dpcm_3bit_dec, endpoint_dpcm_4bit_dec, endpoint_dpcm_5bit_dec, endpoint_dpcm_6bit_dec, endpoint_dpcm_7bit_dec, endpoint_dpcm_8bit_dec;

		basisu::uint8_vec uncomp_mode_bytes, uncomp_solid_dpcm_bytes, uncomp_endpoint_dpcm_reuse_indices, uncomp_use_bc_bits;
		basisu::uint8_vec uncomp_endpoint_dpcm_3bit, uncomp_endpoint_dpcm_4bit, uncomp_endpoint_dpcm_5bit, uncomp_endpoint_dpcm_6bit, uncomp_endpoint_dpcm_7bit, uncomp_endpoint_dpcm_8bit;

		basisu::uint8_vec uncomp_mean0_bits, uncomp_mean1_bytes, uncomp_run_bytes, uncomp_coeff_bytes, uncomp_weight2_bytes, uncomp_weight3_bytes, uncomp_weight4_bytes, uncomp_weight8_bytes;
		simplified_bitwise_decoder mean0_bits, mean1_bytes, run_bytes, coeff_bytes, sign_bits, weight2_bits, weight3_bits, weight4_bits, weight8_bytes;

		const uint8_t* pCur_buf = pComp_data_all + sizeof(xuastc_ldr_full_zstd_header);

		// raw bits
		{
			raw_bits.init(pCur_buf, pHdr->m_raw_bits_len);
			pCur_buf += pHdr->m_raw_bits_len;
		}

		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_mode_bytes_len, uncomp_mode_bytes, comp_mode_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_solid_dpcm_bytes_len, uncomp_solid_dpcm_bytes, solid_dpcm_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_endpoint_dpcm_reuse_indices_len, uncomp_endpoint_dpcm_reuse_indices, endpoint_dpcm_reuse_indices_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_use_bc_bits_len, uncomp_use_bc_bits, use_bc_bits_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_endpoint_dpcm_3bit_len, uncomp_endpoint_dpcm_3bit, endpoint_dpcm_3bit_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_endpoint_dpcm_4bit_len, uncomp_endpoint_dpcm_4bit, endpoint_dpcm_4bit_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_endpoint_dpcm_5bit_len, uncomp_endpoint_dpcm_5bit, endpoint_dpcm_5bit_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_endpoint_dpcm_6bit_len, uncomp_endpoint_dpcm_6bit, endpoint_dpcm_6bit_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_endpoint_dpcm_7bit_len, uncomp_endpoint_dpcm_7bit, endpoint_dpcm_7bit_dec)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_endpoint_dpcm_8bit_len, uncomp_endpoint_dpcm_8bit, endpoint_dpcm_8bit_dec)) 
			return false;
		
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_mean0_bits_len, uncomp_mean0_bits, mean0_bits)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_mean1_bytes_len, uncomp_mean1_bytes, mean1_bytes)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_run_bytes_len, uncomp_run_bytes, run_bytes)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_coeff_bytes_len, uncomp_coeff_bytes, coeff_bytes)) 
			return false;

		// sign
		{
			sign_bits.init(pCur_buf, pHdr->m_sign_bits_len);
			pCur_buf += pHdr->m_sign_bits_len;
		}

		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_weight2_bits_len, uncomp_weight2_bytes, weight2_bits)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_weight3_bits_len, uncomp_weight3_bytes, weight3_bits)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_weight4_bits_len, uncomp_weight4_bytes, weight4_bits)) 
			return false;
		if (!zstd_decompress_and_advance(pCur_buf, pHdr->m_weight8_bytes_len, uncomp_weight8_bytes, weight8_bytes)) 
			return false;

		// sanity check
		const uint64_t total_read_size = pCur_buf - pComp_data_all;
		if (total_read_size > comp_data_size_all)
		{
			BASISU_DEVEL_ERROR("Compressed file is too small\n");
			return false;
		}
		
		const uint32_t header_val = raw_bits.get_bits(FULL_ZSTD_HEADER_MARKER_BITS);
		if (header_val != FULL_ZSTD_HEADER_MARKER)
		{
			BASISU_DEVEL_ERROR("Invalid marker\n");
			return false;
		}

		const uint32_t astc_block_size_index = raw_bits.get_bits(4);
		if (astc_block_size_index >= astc_helpers::NUM_ASTC_BLOCK_SIZES)
		{
			BASISU_DEVEL_ERROR("Invalid block dimension index\n");
			return false;
		}

		astc_block_width = astc_helpers::g_astc_block_sizes[astc_block_size_index][0];
		astc_block_height = astc_helpers::g_astc_block_sizes[astc_block_size_index][1];

		uses_srgb_astc_decode_mode = raw_bits.get_bits(1);

		actual_width = raw_bits.get_bits(16);
		actual_height = raw_bits.get_bits(16);
		has_alpha = raw_bits.get_bits(1);

		const bool use_dct = (raw_bits.get_bits(1) != 0);

		int int_q = 0;
		if (use_dct)
			int_q = raw_bits.get_bits(8);

		const float dct_q = (float)int_q / 2.0f;
		if ((use_dct) && ((dct_q <= 0.0f) || (dct_q > 100.0f)))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid DCT global quality factor\n");
			return false;
		}

		if (debug_output)
		{
			basisu::fmt_debug_printf("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: block dim: {}x{}, image dim: {}x{}, sRGB decode profile: {}, has_alpha: {}, dct: {} dct_q: {}\n",
				astc_block_width, astc_block_height,
				actual_width, actual_height,
				uses_srgb_astc_decode_mode, has_alpha,
				use_dct, dct_q);
		}

		const uint32_t num_blocks_x = (actual_width + astc_block_width - 1) / astc_block_width;
		const uint32_t num_blocks_y = (actual_height + astc_block_height - 1) / astc_block_height;

		if (pInit_callback)
		{
			if (!(*pInit_callback)(num_blocks_x, num_blocks_y, astc_block_width, astc_block_height, uses_srgb_astc_decode_mode, dct_q, has_alpha, pInit_callback_data))
				return false;
		}

		fvec dct_work;

		assert((size_t)astc_block_size_index < std::size(g_encoder_trial_modes));
		const auto& encoder_trial_modes = g_encoder_trial_modes[astc_block_size_index];

		const grid_weight_dct& grid_dct = g_grid_weight_dcts[astc_block_size_index];

		basisu::vector2D<astc_helpers::log_astc_block> log_blocks;
		if (!log_blocks.try_resize(num_blocks_x, 8))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: out of memory\n");
			return false;
		}

		memset(log_blocks.get_ptr(), 0, log_blocks.size_in_bytes());
		
		basisu::vector2D<prev_block_state_full_zstd> prev_block_states;
		if (!prev_block_states.try_resize(num_blocks_x, 2))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: out of memory\n");
			return false;
		}

		uint32_t cur_run_len = 0;

		int part2_hash[PART_HASH_SIZE];
		std::fill(part2_hash, part2_hash + PART_HASH_SIZE, -1);

		int part3_hash[PART_HASH_SIZE];
		std::fill(part3_hash, part3_hash + PART_HASH_SIZE, -1);

		int tm_hash[TM_HASH_SIZE];
		std::fill(tm_hash, tm_hash + TM_HASH_SIZE, -1);

		dct_syms syms;
		syms.m_coeffs.reserve(65);

		for (uint32_t by = 0; by < num_blocks_y; by++)
		{
			for (uint32_t bx = 0; bx < num_blocks_x; bx++)
			{
				prev_block_state_full_zstd& new_prev_state = prev_block_states(bx, by & 1);

				const prev_block_state_full_zstd* pLeft_state = bx ? &prev_block_states(bx - 1, by & 1) : nullptr;
				const prev_block_state_full_zstd* pUpper_state = by ? &prev_block_states(bx, (by - 1) & 1) : nullptr;

				astc_helpers::log_astc_block& log_blk = log_blocks(bx, by & 7);

				if (cur_run_len)
				{
					const prev_block_state_full_zstd* pPrev_block_state = pLeft_state ? pLeft_state : pUpper_state;
					const astc_helpers::log_astc_block& prev_log_blk = bx ? log_blocks(bx - 1, by & 7) : log_blocks(bx, (by - 1) & 7);

					memcpy((void*)&log_blk, (const void*)&prev_log_blk, sizeof(log_blk));

					if (pBlock_callback)
					{
						if (!(*pBlock_callback)(bx, by, prev_log_blk, pBlock_callback_data))
							return false;
					}
										
					new_prev_state.m_tm_index = pPrev_block_state->m_tm_index;
					//new_prev_state.m_base_cem_index = pPrev_block_state->m_base_cem_index;

					cur_run_len--;
					continue;
				}
								
				const prev_block_state_full_zstd* pDiag_state = (bx && by) ? &prev_block_states(bx - 1, (by - 1) & 1) : nullptr;
								
				// TODO: End check
				const uint32_t mode_byte = comp_mode_dec.get_bits8();

				if ((mode_byte & 3) == (uint32_t)xuastc_zstd_mode::cMODE_RUN)
				{
					// run
					cur_run_len = 1 + (mode_byte >> 2);

					if (!bx && !by)
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid run command\n");
						return false;
					}

					const uint32_t max_possible_run_len = num_blocks_x - bx;
					if (cur_run_len > max_possible_run_len)
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid run len\n");
						return false;
					}

					const prev_block_state_full_zstd* pPrev_block_state = pLeft_state ? pLeft_state : pUpper_state;
					const astc_helpers::log_astc_block& prev_log_blk = bx ? log_blocks(bx - 1, by & 7) : log_blocks(bx, (by - 1) & 7);

					memcpy((void*)&log_blk, (const void*)&prev_log_blk, sizeof(log_blk));

					if (pBlock_callback)
					{
						if (!(*pBlock_callback)(bx, by, prev_log_blk, pBlock_callback_data))
							return false;
					}
										
					new_prev_state.m_tm_index = pPrev_block_state->m_tm_index;
										
					cur_run_len--;

					continue;
				}
				else if ((mode_byte & 15) == (uint32_t)xuastc_zstd_mode::cMODE_SOLID)
				{
					// solid
					const astc_helpers::log_astc_block* pPrev_log_blk = bx ? &log_blocks(bx - 1, by & 7) : (by ? &log_blocks(bx, (by - 1) & 7) : nullptr);

					uint32_t prev_solid_color[4] = { 0 };

					if (pPrev_log_blk)
					{
						if (pPrev_log_blk->m_solid_color_flag_ldr)
						{
							prev_solid_color[0] = pPrev_log_blk->m_solid_color[0] >> 8;
							prev_solid_color[1] = pPrev_log_blk->m_solid_color[1] >> 8;
							prev_solid_color[2] = pPrev_log_blk->m_solid_color[2] >> 8;
							prev_solid_color[3] = pPrev_log_blk->m_solid_color[3] >> 8;
						}
						else
						{
							// Decode previous block's first CEM, use the halfway point as the predictor.
							color_rgba prev_l, prev_h;
							decode_endpoints(pPrev_log_blk->m_color_endpoint_modes[0], pPrev_log_blk->m_endpoints, pPrev_log_blk->m_endpoint_ise_range, prev_l, prev_h);

							prev_solid_color[0] = (prev_l[0] + prev_h[0] + 1) >> 1;
							prev_solid_color[1] = (prev_l[1] + prev_h[1] + 1) >> 1;
							prev_solid_color[2] = (prev_l[2] + prev_h[2] + 1) >> 1;
							prev_solid_color[3] = (prev_l[3] + prev_h[3] + 1) >> 1;
						}
					}

					uint32_t delta_r = solid_dpcm_dec.get_bits8();
					uint32_t delta_g = solid_dpcm_dec.get_bits8();
					uint32_t delta_b = solid_dpcm_dec.get_bits8();
					uint32_t delta_a = has_alpha ? solid_dpcm_dec.get_bits8() : 0;

					uint32_t r = (prev_solid_color[0] + delta_r) & 0xFF;
					uint32_t g = (prev_solid_color[1] + delta_g) & 0xFF;
					uint32_t b = (prev_solid_color[2] + delta_b) & 0xFF;
					uint32_t a = 255;
					if (has_alpha)
						a = (prev_solid_color[3] + delta_a) & 0xFF;
					
					log_blk.clear();
					log_blk.m_solid_color_flag_ldr = true;
					log_blk.m_solid_color[0] = (uint16_t)(r | (r << 8));
					log_blk.m_solid_color[1] = (uint16_t)(g | (g << 8));
					log_blk.m_solid_color[2] = (uint16_t)(b | (b << 8));
					log_blk.m_solid_color[3] = (uint16_t)(a | (a << 8));

					if (pBlock_callback)
					{
						if (!(*pBlock_callback)(bx, by, log_blk, pBlock_callback_data))
							return false;
					}
										
					new_prev_state.m_tm_index = -1;
										
					continue;
				}

				new_prev_state.clear();
				
				//log_blk.clear();
				memset((void*)&log_blk, 0, offsetof(astc_helpers::log_astc_block, m_weights));
				
				uint32_t tm_index = 0;
				uint32_t actual_cem = 0;

				if ((mode_byte & 1) == 0)
				{
					// raw
					uint32_t config_reuse_index = (mode_byte >> 1) & 3;

					if (config_reuse_index < 3)
					{
						// 0 = left, 1 = upper, 2 = left-upper
						int cfg_dx = 0, cfg_dy = 0;
						const prev_block_state_full_zstd* pCfg_state = nullptr;

						switch (config_reuse_index)
						{
						case 0: cfg_dx = -1; pCfg_state = pLeft_state; break;
						case 1: cfg_dx = 0; cfg_dy = -1; pCfg_state = pUpper_state; break;
						case 2: cfg_dx = -1; cfg_dy = -1; pCfg_state = pDiag_state; break;
						default: assert(0); break;
						}

						if ((((cfg_dx + (int)bx) < 0) ||
							((cfg_dy + (int)by) < 0)) ||
							(!pCfg_state))
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid config reuse\n");
							return false;
						}

						astc_helpers::log_astc_block& cfg_log_blk = log_blocks((int)bx + cfg_dx, ((int)by + cfg_dy) & 7);

						tm_index = pCfg_state->m_tm_index;
						
						if (pCfg_state->m_tm_index < 0)
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid config reuse\n");
							return false;
						}

						log_blk.m_partition_id = cfg_log_blk.m_partition_id;
						actual_cem = cfg_log_blk.m_color_endpoint_modes[0];

						new_prev_state.m_tm_index = tm_index;
						//new_prev_state.m_base_cem_index = pCfg_state->m_base_cem_index; // base cem not including base+ofs, not actual
					}
					else
					{
						if (mode_byte & XUASTC_LDR_MODE_BYTE_TM_HASH_HIT_FLAG)
						{
							uint32_t tm_hash_index = raw_bits.get_bits(TM_HASH_BITS);
							tm_index = tm_hash[tm_hash_index];
						}
						else
						{
							tm_index = raw_bits.decode_truncated_binary(encoder_trial_modes.size_u32());
							
							tm_hash[tm_hash_index(tm_index)] = tm_index;
						}

						if (tm_index >= encoder_trial_modes.size())
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid tm_index\n");
							return false;
						}

						new_prev_state.m_tm_index = tm_index;

						const trial_mode& tm = encoder_trial_modes[tm_index];

						actual_cem = tm.m_cem;

						if ((tm.m_cem == astc_helpers::CEM_LDR_RGB_DIRECT) || (tm.m_cem == astc_helpers::CEM_LDR_RGBA_DIRECT))
						{
							// Decode is_base_ofs bit
							bool is_base_ofs = (mode_byte & XUASTC_LDR_MODE_BYTE_IS_BASE_OFS_FLAG) != 0;

							if (is_base_ofs)
							{
								if (actual_cem == astc_helpers::CEM_LDR_RGB_DIRECT)
									actual_cem = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
								else if (actual_cem == astc_helpers::CEM_LDR_RGBA_DIRECT)
									actual_cem = astc_helpers::CEM_LDR_RGBA_BASE_PLUS_OFFSET;
							}
						}

						if (tm.m_num_parts > 1)
						{
							const uint32_t total_unique_indices = get_total_unique_patterns(astc_block_size_index, tm.m_num_parts);
							int* pPart_hash = (tm.m_num_parts == 2) ? part2_hash : part3_hash;

							const bool hash_hit_flag = (mode_byte & XUASTC_LDR_MODE_BYTE_PART_HASH_HIT) != 0;
							
							uint32_t unique_pat_index;
							if (hash_hit_flag)
							{
								uint32_t h = raw_bits.get_bits(basist::astc_ldr_t::PART_HASH_BITS);
								
								unique_pat_index = pPart_hash[h];
							}
							else
							{
								unique_pat_index = raw_bits.decode_truncated_binary(total_unique_indices);
																
								pPart_hash[basist::astc_ldr_t::part_hash_index(unique_pat_index)] = unique_pat_index;
							}

							if (unique_pat_index >= get_total_unique_patterns(astc_block_size_index, tm.m_num_parts))
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: invalid unique_pat_index, decompression failed (file corrupt)\n");
								return false;
							}

							log_blk.m_partition_id = unique_pat_index_to_part_seed(astc_block_size_index, tm.m_num_parts, unique_pat_index);
						}


					} // if (config_reuse_index < 3)

					if (tm_index >= encoder_trial_modes.size())
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: invalid tm_index, decompression failed (file corrupt)\n");
						return false;
					}

					const trial_mode& tm = encoder_trial_modes[tm_index];

					const bool actual_cem_supports_bc = astc_helpers::cem_supports_bc(actual_cem);

					const uint32_t total_endpoint_vals = astc_helpers::get_num_cem_values(actual_cem);

					for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
						log_blk.m_color_endpoint_modes[part_iter] = (uint8_t)actual_cem;

					log_blk.m_num_partitions = (uint8_t)tm.m_num_parts;
					log_blk.m_dual_plane = (tm.m_ccs_index >= 0);
					if (log_blk.m_dual_plane)
						log_blk.m_color_component_selector = (uint8_t)tm.m_ccs_index;

					log_blk.m_weight_ise_range = (uint8_t)tm.m_weight_ise_range;
					log_blk.m_endpoint_ise_range = (uint8_t)tm.m_endpoint_ise_range;
					log_blk.m_grid_width = (uint8_t)tm.m_grid_width;
					log_blk.m_grid_height = (uint8_t)tm.m_grid_height;

					const bool used_dpcm_endpoints_flag = (mode_byte & XUASTC_LDR_MODE_BYTE_DPCM_ENDPOINTS_FLAG) != 0;

					if (used_dpcm_endpoints_flag)
					{
						const int num_endpoint_levels = astc_helpers::get_ise_levels(log_blk.m_endpoint_ise_range);
						const auto& endpoint_rank_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_rank_to_ISE;
						const auto& endpoint_ise_to_rank = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_rank;

						uint32_t reuse_delta_index = endpoint_dpcm_reuse_indices_dec.get_bits8();
						if (reuse_delta_index >= NUM_REUSE_XY_DELTAS)
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid reuse delta\n");
							return false;
						}

						const int reuse_bx = (int)bx + basist::astc_6x6_hdr::g_reuse_xy_deltas[reuse_delta_index].m_x;
						const int reuse_by = (int)by + basist::astc_6x6_hdr::g_reuse_xy_deltas[reuse_delta_index].m_y;

						if ((reuse_bx < 0) || (reuse_by < 0) || (reuse_bx >= (int)num_blocks_x) || (reuse_by >= (int)num_blocks_y))
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid reuse delta\n");
							return false;
						}

						const astc_helpers::log_astc_block* pEndpoint_pred_log_blk = &log_blocks(reuse_bx, reuse_by & 7);
						if (pEndpoint_pred_log_blk->m_solid_color_flag_ldr)
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid reuse delta\n");
							return false;
						}

						bool endpoints_use_bc[astc_helpers::MAX_PARTITIONS] = { };

						if (actual_cem_supports_bc)
						{
							for (uint32_t part_iter = 0; part_iter < log_blk.m_num_partitions; part_iter++)
								endpoints_use_bc[part_iter] = (use_bc_bits_dec.get_bits1() != 0);
						}

						uint8_t predicted_endpoints[astc_helpers::MAX_PARTITIONS][astc_helpers::MAX_CEM_ENDPOINT_VALS] = { };

						for (uint32_t part_iter = 0; part_iter < log_blk.m_num_partitions; part_iter++)
						{
							const bool always_repack_flag = false;
							bool blue_contraction_clamped_flag = false, base_ofs_clamped_flag = false;

							// Mini-CEM encoder, to cross CEM domains.
							bool conv_status = convert_endpoints_across_cems(
								pEndpoint_pred_log_blk->m_color_endpoint_modes[0], pEndpoint_pred_log_blk->m_endpoint_ise_range, pEndpoint_pred_log_blk->m_endpoints,
								log_blk.m_color_endpoint_modes[0], log_blk.m_endpoint_ise_range, predicted_endpoints[part_iter],
								always_repack_flag,
								endpoints_use_bc[part_iter], false,
								blue_contraction_clamped_flag, base_ofs_clamped_flag);

							if (!conv_status)
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Failed predicting endpoints\n");
								return false;
							}
						}

						if (num_endpoint_levels <= 8)
						{
							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									const uint32_t endpoint_idx = part_iter * total_endpoint_vals + val_iter;
									
									int delta = endpoint_dpcm_3bit_dec.get_bits4();
																		
									int e_val = (delta + endpoint_ise_to_rank[predicted_endpoints[part_iter][val_iter]]) % num_endpoint_levels;
									log_blk.m_endpoints[endpoint_idx] = endpoint_rank_to_ise[e_val];
								}
							}
						}
						else if (num_endpoint_levels <= 16)
						{
							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									const uint32_t endpoint_idx = part_iter * total_endpoint_vals + val_iter;

									int delta = endpoint_dpcm_4bit_dec.get_bits4();
																		
									int e_val = (delta + endpoint_ise_to_rank[predicted_endpoints[part_iter][val_iter]]) % num_endpoint_levels;
									log_blk.m_endpoints[endpoint_idx] = endpoint_rank_to_ise[e_val];
								}
							}
						}
						else if (num_endpoint_levels <= 32)
						{
							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									const uint32_t endpoint_idx = part_iter * total_endpoint_vals + val_iter;

									int delta = endpoint_dpcm_5bit_dec.get_bits8();
																		
									int e_val = (delta + endpoint_ise_to_rank[predicted_endpoints[part_iter][val_iter]]) % num_endpoint_levels;
									log_blk.m_endpoints[endpoint_idx] = endpoint_rank_to_ise[e_val];
								}
							}
						}
						else if (num_endpoint_levels <= 64)
						{
							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									const uint32_t endpoint_idx = part_iter * total_endpoint_vals + val_iter;

									int delta = endpoint_dpcm_6bit_dec.get_bits8();
																		
									int e_val = (delta + endpoint_ise_to_rank[predicted_endpoints[part_iter][val_iter]]) % num_endpoint_levels;
									log_blk.m_endpoints[endpoint_idx] = endpoint_rank_to_ise[e_val];
								}
							}
						}
						else if (num_endpoint_levels <= 128)
						{
							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									const uint32_t endpoint_idx = part_iter * total_endpoint_vals + val_iter;

									int delta = endpoint_dpcm_7bit_dec.get_bits8();
																		
									int e_val = (delta + endpoint_ise_to_rank[predicted_endpoints[part_iter][val_iter]]) % num_endpoint_levels;
									log_blk.m_endpoints[endpoint_idx] = endpoint_rank_to_ise[e_val];
								}
							}
						}
						else
						{
							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									const uint32_t endpoint_idx = part_iter * total_endpoint_vals + val_iter;

									int delta = endpoint_dpcm_8bit_dec.get_bits8();
																		
									int e_val = (delta + endpoint_ise_to_rank[predicted_endpoints[part_iter][val_iter]]) % num_endpoint_levels;
									log_blk.m_endpoints[endpoint_idx] = endpoint_rank_to_ise[e_val];
								}
							}
						}
					}
					else
					{
						if (!decode_values(raw_bits, tm.m_num_parts * total_endpoint_vals, log_blk.m_endpoint_ise_range, log_blk.m_endpoints))
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: decode_values() failed\n");
							return false;
						}
					}
				}
				else if ((mode_byte & 15) >= (uint32_t)xuastc_zstd_mode::cMODE_REUSE_CFG_ENDPOINTS_LEFT)
				{
					// reuse full cfg+endpoints+part id
					const uint32_t reuse_index = ((mode_byte >> 2) & 3) - 1;

					int cfg_dx = 0, cfg_dy = 0;
					const prev_block_state_full_zstd* pCfg_state = nullptr;

					switch (reuse_index)
					{
					case 0: cfg_dx = -1; pCfg_state = pLeft_state;  break;
					case 1: cfg_dx = 0; cfg_dy = -1; pCfg_state = pUpper_state;  break;
					case 2: cfg_dx = -1; cfg_dy = -1; pCfg_state = pDiag_state;  break;
					default: assert(0);  break;
					}

					if ((((cfg_dx + (int)bx) < 0) ||
						((cfg_dy + (int)by) < 0)) ||
						(!pCfg_state))
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid config reuse\n");
						return false;
					}

					const astc_helpers::log_astc_block& cfg_log_blk = log_blocks((int)bx + cfg_dx, ((int)by + cfg_dy) & 7);

					if (pCfg_state->m_tm_index < 0)
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Invalid config reuse\n");
						return false;
					}

					tm_index = pCfg_state->m_tm_index;
					actual_cem = cfg_log_blk.m_color_endpoint_modes[0];
										
					for (uint32_t i = 0; i < cfg_log_blk.m_num_partitions; i++)
						log_blk.m_color_endpoint_modes[i] = (uint8_t)actual_cem;

					log_blk.m_dual_plane = cfg_log_blk.m_dual_plane;
					log_blk.m_color_component_selector = cfg_log_blk.m_color_component_selector;
					log_blk.m_num_partitions = cfg_log_blk.m_num_partitions;
					log_blk.m_partition_id = cfg_log_blk.m_partition_id;
					log_blk.m_endpoint_ise_range = cfg_log_blk.m_endpoint_ise_range;
					log_blk.m_weight_ise_range = cfg_log_blk.m_weight_ise_range;
					log_blk.m_grid_width = cfg_log_blk.m_grid_width;
					log_blk.m_grid_height = cfg_log_blk.m_grid_height;

					const uint32_t total_endpoint_vals = astc_helpers::get_num_cem_values(actual_cem) * log_blk.m_num_partitions;
					memcpy(log_blk.m_endpoints, cfg_log_blk.m_endpoints, total_endpoint_vals);

					new_prev_state.m_tm_index = tm_index;
				}
				else
				{
					// shouldn't actually get here
					BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: decompression failed\n");
					return false;
				}

				// Decode weights

				if (tm_index >= encoder_trial_modes.size())
				{
					BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd: invalid tm_index, decompression failed (file corrupt)\n");
					return false;
				}

				const trial_mode& tm = encoder_trial_modes[tm_index];

				const uint32_t total_planes = (tm.m_ccs_index >= 0) ? 2 : 1;
				const uint32_t total_weights = tm.m_grid_width * tm.m_grid_height;

				bool block_used_dct = false;
				if (use_dct)
					block_used_dct = ((mode_byte & XUASTC_LDR_MODE_BYTE_USE_DCT) != 0);

				if (block_used_dct)
				{
					const uint32_t num_dc_levels = grid_weight_dct::get_num_weight_dc_levels(log_blk.m_weight_ise_range);
					syms.m_num_dc_levels = num_dc_levels;

					for (uint32_t plane_iter = 0; plane_iter < total_planes; plane_iter++)
					{
						syms.m_coeffs.resize(0);

						if (num_dc_levels == DCT_MEAN_LEVELS1)
							syms.m_dc_sym = mean1_bytes.get_bits8();
						else
							syms.m_dc_sym = mean0_bits.get_bits4();

						uint32_t cur_zig_ofs = 1;

						while (cur_zig_ofs < total_weights)
						{
							uint32_t run_len = run_bytes.get_bits8();
							if (run_len == DCT_RUN_LEN_EOB_SYM_INDEX)
								break;

							cur_zig_ofs += run_len;

							if (cur_zig_ofs >= total_weights)
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::DCT decode error\n");
								return false;
							}

							int sign = sign_bits.get_bits1();
							int coeff = coeff_bytes.get_bits8() + 1;

							if (sign)
								coeff = -coeff;

							syms.m_coeffs.push_back(dct_syms::coeff(basisu::safe_cast_uint16(run_len), basisu::safe_cast_int16(coeff)));
							cur_zig_ofs++;
						}

						// weight grid IDCT
						if (!grid_dct.decode_block_weights(dct_q, plane_iter, log_blk, nullptr, nullptr, dct_work, &syms))
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::DCT decode failed\n");
							return false;
						}

					} // plane_iter
				}
				else
				{
					// Weight grid DPCM (no dependency on other blocks, or between planes, for determinism even when IDCT is used)
					const uint32_t num_weight_levels = astc_helpers::get_ise_levels(log_blk.m_weight_ise_range);
					const auto& weight_rank_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;

					for (uint32_t plane_iter = 0; plane_iter < total_planes; plane_iter++)
					{
						int prev_w = num_weight_levels / 2;

						if (num_weight_levels < 4)
						{
							for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
							{
								uint32_t r = weight2_bits.get_bits2();

								uint32_t w = (prev_w + r) % num_weight_levels;

								prev_w = w;

								log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

							} // weight_iter
						}
						else if (num_weight_levels == 4)
						{
							for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
							{
								uint32_t r = weight2_bits.get_bits2();

								uint32_t w = (prev_w + r) & 3;

								prev_w = w;

								log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

							} // weight_iter
						}
						else if (num_weight_levels < 8)
						{
							for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
							{
								uint32_t r = weight3_bits.get_bits4();

								uint32_t w = (prev_w + r) % num_weight_levels;

								prev_w = w;

								log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

							} // weight_iter
						}
						else if (num_weight_levels == 8)
						{
							for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
							{
								uint32_t r = weight3_bits.get_bits4();

								uint32_t w = (prev_w + r) & 7;

								prev_w = w;

								log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

							} // weight_iter
						}
						else if (num_weight_levels < 16)
						{
							for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
							{
								uint32_t r = weight4_bits.get_bits4();

								uint32_t w = (prev_w + r) % num_weight_levels;

								prev_w = w;

								log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

							} // weight_iter
						}
						else if (num_weight_levels == 16)
						{
							for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
							{
								uint32_t r = weight4_bits.get_bits4();

								uint32_t w = (prev_w + r) & 15;

								prev_w = w;

								log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

							} // weight_iter
						}
						else
						{
							for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
							{
								uint32_t r = weight8_bytes.get_bits8();

								uint32_t w = (prev_w + r) % num_weight_levels;

								prev_w = w;

								log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

							} // weight_iter
						}

					} // plane_iter

				} // if (block_used_dct)

				if (pBlock_callback)
				{
					if (!(*pBlock_callback)(bx, by, log_blk, pBlock_callback_data))
						return false;
				}
			
			} // bx 

		} // by

		assert(!cur_run_len);

		const uint32_t final_sync_marker = raw_bits.get_bits(FINAL_SYNC_MARKER_BITS);
		if (final_sync_marker != FINAL_SYNC_MARKER)
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Final sync check failed (1)\n");
			return false;
		}

		if (comp_mode_dec.m_pBuf != comp_mode_dec.m_pBuf_end)
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image_full_zstd::Final sync check failed (2)\n");
			return false;
		}

		return true;
	}
		
	bool xuastc_ldr_decompress_image(
		const uint8_t* pComp_data_all, size_t comp_data_size_all,
		uint32_t& astc_block_width, uint32_t& astc_block_height,
		uint32_t& actual_width, uint32_t& actual_height, bool& has_alpha, bool& uses_srgb_astc_decode_mode,
		bool debug_output,
		xuastc_decomp_image_init_callback_ptr pInit_callback, void* pInit_callback_data,
		xuastc_decomp_image_block_callback_ptr pBlock_callback, void* pBlock_callback_data)
	{
		if (debug_output)
			basisu::debug_printf("\n------------------- astc_ldr_t::decompress_image\n");

		assert(g_initialized);

		astc_block_width = 0;
		astc_block_height = 0;
		actual_width = 0;
		actual_height = 0;
		has_alpha = false;
		uses_srgb_astc_decode_mode = false;

		if (!g_initialized)
		{
			BASISU_DEVEL_ERROR("Not initialized");
			//dec_blocks.clear();
			return false;
		}

		if (comp_data_size_all < 1)
		{
			BASISU_DEVEL_ERROR("Compressed file is too small\n");
			return false;
		}

		const uint8_t first_comp_byte = pComp_data_all[0];

		if (first_comp_byte == (uint8_t)xuastc_ldr_syntax::cFullZStd)
		{
			return xuastc_ldr_decompress_image_full_zstd(
				pComp_data_all, comp_data_size_all,
				astc_block_width, astc_block_height,
				actual_width, actual_height, has_alpha, uses_srgb_astc_decode_mode,
				debug_output,
				pInit_callback, pInit_callback_data,
				pBlock_callback, pBlock_callback_data);
		}

		// Either full arith or hybrid arith+zstd now
				
		const xuastc_ldr_arith_header* pHdr = nullptr;

		const uint8_t* pComp_data = pComp_data_all + 1;
		size_t comp_data_size = comp_data_size_all - 1;
				
		basisu::uint8_vec uncomp_mean0_bits, uncomp_mean1_bytes, uncomp_run_bytes, uncomp_coeff_bytes, uncomp_weight2_bytes, uncomp_weight3_bytes, uncomp_weight4_bytes, uncomp_weight8_bytes;
		simplified_bitwise_decoder mean0_bits, mean1_bytes, run_bytes, coeff_bytes, sign_bits, weight2_bits, weight3_bits, weight4_bits, weight8_bytes;
		bool use_fast_decoding = false;
								
		if (first_comp_byte == (uint8_t)xuastc_ldr_syntax::cHybridArithZStd)
		{
			if (comp_data_size_all < sizeof(xuastc_ldr_arith_header))
			{
				BASISU_DEVEL_ERROR("Compressed file is too small\n");
				return false;
			}

			pHdr = (const xuastc_ldr_arith_header*)pComp_data_all;

			if (pHdr->m_arith_bytes_len < arith::ArithMinExpectedDataBufSize)
			{
				BASISU_DEVEL_ERROR("Invalid header\n");
				return false;
			}

			const uint64_t total_comp_size = (uint64_t)((uint32_t)pHdr->m_arith_bytes_len) + 
				pHdr->m_mean0_bits_len + pHdr->m_mean1_bytes_len +
				pHdr->m_run_bytes_len + pHdr->m_coeff_bytes_len + pHdr->m_sign_bits_len + 
				pHdr->m_weight2_bits_len + pHdr->m_weight3_bits_len + pHdr->m_weight4_bits_len + pHdr->m_weight8_bytes_len;

			if ((sizeof(xuastc_ldr_arith_header) + total_comp_size) > comp_data_size_all)
			{
				BASISU_DEVEL_ERROR("Compressed file is too small\n");
				return false;
			}
			
			pComp_data = pComp_data_all + sizeof(xuastc_ldr_arith_header);
			comp_data_size = pHdr->m_arith_bytes_len;

			const uint8_t* pCur_buf = (const uint8_t*)pComp_data + comp_data_size;

			// mean0
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_mean0_bits_len, uncomp_mean0_bits);
				if (!status)
					return false;
				pCur_buf += pHdr->m_mean0_bits_len;
				mean0_bits.init(uncomp_mean0_bits);
			}

			// mean1
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_mean1_bytes_len, uncomp_mean1_bytes);
				if (!status)
					return false;
				pCur_buf += pHdr->m_mean1_bytes_len;
				mean1_bytes.init(uncomp_mean1_bytes);
			}

			// run
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_run_bytes_len, uncomp_run_bytes);
				if (!status)
					return false;
				pCur_buf += pHdr->m_run_bytes_len;
				run_bytes.init(uncomp_run_bytes);
			}

			// coeff
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_coeff_bytes_len, uncomp_coeff_bytes);
				if (!status)
					return false;
				pCur_buf += pHdr->m_coeff_bytes_len;
				coeff_bytes.init(uncomp_coeff_bytes);
			}

			// sign
			{
				sign_bits.init(pCur_buf, pHdr->m_sign_bits_len);
				pCur_buf += pHdr->m_sign_bits_len;
			}

			// weight2 
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_weight2_bits_len, uncomp_weight2_bytes);
				if (!status)
					return false;
				pCur_buf += pHdr->m_weight2_bits_len;
				weight2_bits.init(uncomp_weight2_bytes);
			}

			// weight3
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_weight3_bits_len, uncomp_weight3_bytes);
				if (!status)
					return false;
				pCur_buf += pHdr->m_weight3_bits_len;
				weight3_bits.init(uncomp_weight3_bytes);
			}

			// weight4
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_weight4_bits_len, uncomp_weight4_bytes);
				if (!status)
					return false;
				pCur_buf += pHdr->m_weight4_bits_len;
				weight4_bits.init(uncomp_weight4_bytes);
			}

			// weight8
			{
				bool status = zstd_decompress(pCur_buf, pHdr->m_weight8_bytes_len, uncomp_weight8_bytes);
				if (!status)
					return false;
				pCur_buf += pHdr->m_weight8_bytes_len;
				weight8_bytes.init(uncomp_weight8_bytes);
			}

			// sanity check
			const uint64_t total_read_size = pCur_buf - pComp_data_all;
			if (total_read_size > comp_data_size_all)
			{
				BASISU_DEVEL_ERROR("Compressed file is too small\n");
				return false;
			}

			use_fast_decoding = true;
		}

		if (comp_data_size < arith::ArithMinExpectedDataBufSize)
		{
			BASISU_DEVEL_ERROR("Compressed file is too small\n");
			return false;
		}
		
		//interval_timer itm;
		//itm.start();

		arith::arith_dec dec;
		if (!dec.init(pComp_data, comp_data_size))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid compressed data\n");
			return false;
		}

		const uint32_t header_val = dec.get_bits(ARITH_HEADER_MARKER_BITS);
		if (header_val != ARITH_HEADER_MARKER)
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Unexpected header marker\n");
			return false;
		}

		const uint32_t astc_block_size_index = dec.get_bits(4);
		if (astc_block_size_index >= astc_helpers::NUM_ASTC_BLOCK_SIZES)
		{
			BASISU_DEVEL_ERROR("Invalid block dimension index\n");
			return false;
		}

		const uint32_t block_width = astc_helpers::g_astc_block_sizes[astc_block_size_index][0];
		const uint32_t block_height = astc_helpers::g_astc_block_sizes[astc_block_size_index][1];

		// sanity checks
		assert((int)astc_block_size_index == astc_helpers::find_astc_block_size_index(block_width, block_height));
		assert(astc_helpers::is_valid_block_size(block_width, block_height));

		astc_block_width = block_width;
		astc_block_height = block_height;

		//const uint32_t total_block_pixels = block_width * block_height;

		uses_srgb_astc_decode_mode = dec.get_bit();

		//const astc_helpers::decode_mode dec_mode = uses_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8;

		const uint32_t width = dec.get_bits(16);
		const uint32_t height = dec.get_bits(16);

		if ((width < 1) || (height < 1))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid image dimension\n");
			return false;
		}

		actual_width = width;
		actual_height = height;

		has_alpha = dec.get_bit();

		const bool use_dct = (dec.get_bits(1) != 0);

		int int_q = 0;
		if (use_dct)
			int_q = dec.get_bits(8);

		const float dct_q = (float)int_q / 2.0f;
		if ((use_dct) && ((dct_q <= 0.0f) || (dct_q > 100.0f)))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid DCT global quality factor\n");
			return false;
		}

		if (debug_output)
		{
			basisu::fmt_debug_printf("astc_ldr_t::decompress_image: block dim: {}x{}, image dim: {}x{}, sRGB decode profile: {}, has_alpha: {}, dct: {} dct_q: {}\n",
				block_width, block_height,
				width, height,
				uses_srgb_astc_decode_mode, has_alpha, 
				use_dct, dct_q);
		}

		const uint32_t num_blocks_x = (width + block_width - 1) / block_width;
		const uint32_t num_blocks_y = (height + block_height - 1) / block_height;

		if (pInit_callback)
		{
			if (!(*pInit_callback)(num_blocks_x, num_blocks_y, block_width, block_height, uses_srgb_astc_decode_mode, dct_q, has_alpha, pInit_callback_data))
				return false;
		}

		assert((size_t)astc_block_size_index < std::size(g_encoder_trial_modes));
		const auto& encoder_trial_modes = g_encoder_trial_modes[astc_block_size_index];
		
		assert((size_t)astc_block_size_index < std::size(g_grouped_encoder_trial_modes));
		const auto& grouped_encoder_trial_modes = g_grouped_encoder_trial_modes[astc_block_size_index];

		arith::arith_data_model mode_model((uint32_t)xuastc_mode::cMODE_TOTAL);

		arith::arith_data_model solid_color_dpcm_model[4];
		for (uint32_t i = 0; i < 4; i++)
			solid_color_dpcm_model[i].init(256, true);

		arith::arith_data_model raw_endpoint_models[astc_helpers::TOTAL_ENDPOINT_ISE_RANGES];
		for (uint32_t i = 0; i < astc_helpers::TOTAL_ENDPOINT_ISE_RANGES; i++)
			raw_endpoint_models[i].init(astc_helpers::get_ise_levels(astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE + i));

		arith::arith_data_model dpcm_endpoint_models[astc_helpers::TOTAL_ENDPOINT_ISE_RANGES];
		for (uint32_t i = 0; i < astc_helpers::TOTAL_ENDPOINT_ISE_RANGES; i++)
			dpcm_endpoint_models[i].init(astc_helpers::get_ise_levels(astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE + i));
				
		arith::arith_bit_model is_base_ofs_model;
		arith::arith_bit_model use_dct_model[4];
		arith::arith_bit_model use_dpcm_endpoints_model;

		arith::arith_data_model cem_index_model[8];
		for (uint32_t i = 0; i < 8; i++)
			cem_index_model[i].init(OTM_NUM_CEMS);

		arith::arith_data_model subset_index_model[OTM_NUM_SUBSETS];
		for (uint32_t i = 0; i < OTM_NUM_SUBSETS; i++)
			subset_index_model[i].init(OTM_NUM_SUBSETS);

		arith::arith_data_model ccs_index_model[OTM_NUM_CCS];
		for (uint32_t i = 0; i < OTM_NUM_CCS; i++)
			ccs_index_model[i].init(OTM_NUM_CCS);

		arith::arith_data_model grid_size_model[OTM_NUM_GRID_SIZES];
		for (uint32_t i = 0; i < OTM_NUM_GRID_SIZES; i++)
			grid_size_model[i].init(OTM_NUM_GRID_SIZES);

		arith::arith_data_model grid_aniso_model[OTM_NUM_GRID_ANISOS];
		for (uint32_t i = 0; i < OTM_NUM_GRID_ANISOS; i++)
			grid_aniso_model[i].init(OTM_NUM_GRID_ANISOS);

		arith::arith_data_model dct_run_len_model; // [0,63] or 64=EOB
		arith::arith_data_model dct_coeff_mag; // [1,255] (blocks with larger mags go DPCM)
		arith::arith_data_model weight_mean_models[2];
		arith::arith_data_model raw_weight_models[astc_helpers::TOTAL_WEIGHT_ISE_RANGES];

		if (!use_fast_decoding)
		{
			// Models used for weight decompression in pure arithmetic mode.
			dct_run_len_model.init(65);
			dct_coeff_mag.init(255);

			weight_mean_models[0].init(DCT_MEAN_LEVELS0);
			weight_mean_models[1].init(DCT_MEAN_LEVELS1);
			
			for (uint32_t i = 0; i < astc_helpers::TOTAL_WEIGHT_ISE_RANGES; i++)
				raw_weight_models[i].init(astc_helpers::get_ise_levels(astc_helpers::FIRST_VALID_WEIGHT_ISE_RANGE + i));
		}
		
		const grid_weight_dct& grid_dct = g_grid_weight_dcts[astc_block_size_index];
				
		basisu::vector2D<astc_helpers::log_astc_block> log_blocks;
		if (!log_blocks.try_resize(num_blocks_x, 8))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image: out of memory\n");
			return false;
		}

		memset(log_blocks.get_ptr(), 0, log_blocks.size_in_bytes());
				
		basisu::vector2D<prev_block_state> prev_block_states;
		if (!prev_block_states.try_resize(num_blocks_x, 2))
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image: out of memory\n");
			return false;
		}

		arith::arith_data_model submode_models[OTM_NUM_CEMS][OTM_NUM_SUBSETS][OTM_NUM_CCS][OTM_NUM_GRID_SIZES][OTM_NUM_GRID_ANISOS];

		arith::arith_bit_model endpoints_use_bc_models[4];

		arith::arith_data_model endpoint_reuse_delta_model(basist::astc_6x6_hdr::NUM_REUSE_XY_DELTAS);
				
		arith::arith_data_model config_reuse_model[4];
		for (uint32_t i = 0; i < 4; i++)
			config_reuse_model[i].init(4);

		arith::arith_gamma_contexts m_run_len_contexts;
		uint32_t cur_run_len = 0;

		int part2_hash[PART_HASH_SIZE];
		std::fill(part2_hash, part2_hash + PART_HASH_SIZE, -1);

		int part3_hash[PART_HASH_SIZE];
		std::fill(part3_hash, part3_hash + PART_HASH_SIZE, -1);

		arith::arith_bit_model use_part_hash_model[4];
		arith::arith_data_model part2_hash_index_model(PART_HASH_SIZE, true);
		arith::arith_data_model part3_hash_index_model(PART_HASH_SIZE, true);

		//if (debug_output)
		//	debug_printf("Decompressor init time finish: {} secs\n", itm.get_elapsed_secs());

		//itm.start();

		dct_syms syms;
		syms.m_coeffs.reserve(65);

		fvec dct_work;
						
		for (uint32_t by = 0; by < num_blocks_y; by++)
		{
			for (uint32_t bx = 0; bx < num_blocks_x; bx++)
			{
				prev_block_state& new_prev_state = prev_block_states(bx, by & 1);
				new_prev_state.clear();

				const prev_block_state* pLeft_state = bx ? &prev_block_states(bx - 1, by & 1) : nullptr;
				const prev_block_state* pUpper_state = by ? &prev_block_states(bx, (by - 1) & 1) : nullptr;
				const prev_block_state* pDiag_state = (bx && by) ? &prev_block_states(bx - 1, (by - 1) & 1) : nullptr;
				const prev_block_state* pPred_state = pLeft_state ? pLeft_state : pUpper_state; // left or upper, or nullptr on first block

				astc_helpers::log_astc_block& log_blk = log_blocks(bx, by & 7);

				if (cur_run_len)
				{
					const prev_block_state* pPrev_block_state = pLeft_state ? pLeft_state : pUpper_state;
					const astc_helpers::log_astc_block& prev_log_blk = bx ? log_blocks(bx - 1, by & 7) : log_blocks(bx, (by - 1) & 7);

					log_blk = prev_log_blk;

					if (pBlock_callback)
					{
						if (!(*pBlock_callback)(bx, by, prev_log_blk, pBlock_callback_data))
							return false;
					}

					new_prev_state.m_was_solid_color = pPrev_block_state->m_was_solid_color;
					new_prev_state.m_used_weight_dct = pPrev_block_state->m_used_weight_dct;
					new_prev_state.m_first_endpoint_uses_bc = pPrev_block_state->m_first_endpoint_uses_bc;
					new_prev_state.m_reused_full_cfg = true;
					new_prev_state.m_tm_index = pPrev_block_state->m_tm_index;
					new_prev_state.m_base_cem_index = pPrev_block_state->m_base_cem_index;
					new_prev_state.m_subset_index = pPrev_block_state->m_subset_index;
					new_prev_state.m_ccs_index = pPrev_block_state->m_ccs_index;
					new_prev_state.m_grid_size = pPrev_block_state->m_grid_size;
					new_prev_state.m_grid_aniso = pPrev_block_state->m_grid_aniso;
					new_prev_state.m_used_part_hash = pPrev_block_state->m_used_part_hash;

					cur_run_len--;
					continue;
				}

				log_blk.clear();

				uint32_t mode_index = dec.decode_sym(mode_model);

				switch (mode_index)
				{
				case (uint32_t)xuastc_mode::cMODE_SOLID:
				{
					const astc_helpers::log_astc_block* pPrev_log_blk = bx ? &log_blocks(bx - 1, by & 7) : (by ? &log_blocks(bx, (by - 1) & 7) : nullptr);

					uint32_t prev_solid_color[4] = { 0 };

					if (pPrev_log_blk)
					{
						if (pPrev_log_blk->m_solid_color_flag_ldr)
						{
							prev_solid_color[0] = pPrev_log_blk->m_solid_color[0] >> 8;
							prev_solid_color[1] = pPrev_log_blk->m_solid_color[1] >> 8;
							prev_solid_color[2] = pPrev_log_blk->m_solid_color[2] >> 8;
							prev_solid_color[3] = pPrev_log_blk->m_solid_color[3] >> 8;
						}
						else
						{
							// Decode previous block's first CEM, use the halfway point as the predictor.
							color_rgba prev_l, prev_h;
							decode_endpoints(pPrev_log_blk->m_color_endpoint_modes[0], pPrev_log_blk->m_endpoints, pPrev_log_blk->m_endpoint_ise_range, prev_l, prev_h);

							prev_solid_color[0] = (prev_l[0] + prev_h[0] + 1) >> 1;
							prev_solid_color[1] = (prev_l[1] + prev_h[1] + 1) >> 1;
							prev_solid_color[2] = (prev_l[2] + prev_h[2] + 1) >> 1;
							prev_solid_color[3] = (prev_l[3] + prev_h[3] + 1) >> 1;
						}
					}

					uint32_t r = (prev_solid_color[0] + dec.decode_sym(solid_color_dpcm_model[0])) & 0xFF;
					uint32_t g = (prev_solid_color[1] + dec.decode_sym(solid_color_dpcm_model[1])) & 0xFF;
					uint32_t b = (prev_solid_color[2] + dec.decode_sym(solid_color_dpcm_model[2])) & 0xFF;

					uint32_t a = 255;
					if (has_alpha)
						a = (prev_solid_color[3] + dec.decode_sym(solid_color_dpcm_model[3])) & 0xFF;

					log_blk.m_solid_color_flag_ldr = true;
					log_blk.m_solid_color[0] = (uint16_t)(r | (r << 8));
					log_blk.m_solid_color[1] = (uint16_t)(g | (g << 8));
					log_blk.m_solid_color[2] = (uint16_t)(b | (b << 8));
					log_blk.m_solid_color[3] = (uint16_t)(a | (a << 8));

					if (pBlock_callback)
					{
						if (!(*pBlock_callback)(bx, by, log_blk, pBlock_callback_data))
							return false;
					}

					// Bias the statistics towards using DCT (most common case).
					if (use_dct)
						new_prev_state.m_used_weight_dct = true;

					new_prev_state.m_first_endpoint_uses_bc = true;
					new_prev_state.m_was_solid_color = true;
					new_prev_state.m_tm_index = -1;
					new_prev_state.m_base_cem_index = astc_helpers::CEM_LDR_RGB_DIRECT;
					new_prev_state.m_subset_index = 0;
					new_prev_state.m_ccs_index = 0;
					new_prev_state.m_grid_size = 0;
					new_prev_state.m_grid_aniso = 0;
					new_prev_state.m_reused_full_cfg = false;
					new_prev_state.m_used_part_hash = true; // bias to true

					break;
				}
				case (uint32_t)xuastc_mode::cMODE_RUN:
				{
					if (!bx && !by)
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid run command\n");
						return false;
					}

					cur_run_len = dec.decode_gamma(m_run_len_contexts);
					if (!cur_run_len)
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid run len\n");
						return false;
					}

					const uint32_t max_possible_run_len = num_blocks_x - bx;
					if (cur_run_len > max_possible_run_len)
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid run len\n");
						return false;
					}

					const prev_block_state* pPrev_block_state = pLeft_state ? pLeft_state : pUpper_state;
					const astc_helpers::log_astc_block& prev_log_blk = bx ? log_blocks(bx - 1, by & 7) : log_blocks(bx, (by - 1) & 7);

					log_blk = prev_log_blk;

					if (pBlock_callback)
					{
						if (!(*pBlock_callback)(bx, by, prev_log_blk, pBlock_callback_data))
							return false;
					}

					new_prev_state.m_was_solid_color = pPrev_block_state->m_was_solid_color;
					new_prev_state.m_used_weight_dct = pPrev_block_state->m_used_weight_dct;
					new_prev_state.m_first_endpoint_uses_bc = pPrev_block_state->m_first_endpoint_uses_bc;
					new_prev_state.m_reused_full_cfg = true;
					new_prev_state.m_tm_index = pPrev_block_state->m_tm_index;
					new_prev_state.m_base_cem_index = pPrev_block_state->m_base_cem_index;
					new_prev_state.m_subset_index = pPrev_block_state->m_subset_index;
					new_prev_state.m_ccs_index = pPrev_block_state->m_ccs_index;
					new_prev_state.m_grid_size = pPrev_block_state->m_grid_size;
					new_prev_state.m_grid_aniso = pPrev_block_state->m_grid_aniso;
					new_prev_state.m_used_part_hash = pPrev_block_state->m_used_part_hash;

					cur_run_len--;

					break;
				}
				case (uint32_t)xuastc_mode::cMODE_RAW:
				case (uint32_t)xuastc_mode::cMODE_REUSE_CFG_ENDPOINTS_LEFT:
				case (uint32_t)xuastc_mode::cMODE_REUSE_CFG_ENDPOINTS_UP:
				case (uint32_t)xuastc_mode::cMODE_REUSE_CFG_ENDPOINTS_DIAG:
				{
					uint32_t tm_index = 0;
					uint32_t actual_cem = 0;

					if (mode_index != (uint32_t)xuastc_mode::cMODE_RAW)
					{
						// Full config+part ID+endpoint reuse from an immediate neighbor
						// 
						// 0 = left, 1 = upper, 2 = left-upper
						int cfg_dx = 0, cfg_dy = 0;
						const prev_block_state* pCfg_state = nullptr;

						switch (mode_index)
						{
						case (uint32_t)xuastc_mode::cMODE_REUSE_CFG_ENDPOINTS_LEFT: cfg_dx = -1; pCfg_state = pLeft_state;  break;
						case (uint32_t)xuastc_mode::cMODE_REUSE_CFG_ENDPOINTS_UP: cfg_dx = 0; cfg_dy = -1; pCfg_state = pUpper_state;  break;
						case (uint32_t)xuastc_mode::cMODE_REUSE_CFG_ENDPOINTS_DIAG: cfg_dx = -1; cfg_dy = -1; pCfg_state = pDiag_state;  break;
						default: assert(0);  break;
						}

						if ((((cfg_dx + (int)bx) < 0) ||
							((cfg_dy + (int)by) < 0)) ||
							(!pCfg_state))
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid config reuse\n");
							return false;
						}

						if (pCfg_state->m_tm_index < 0)
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::xuastc_ldr_decompress_image::Invalid config reuse\n");
							return false;
						}

						const astc_helpers::log_astc_block& cfg_log_blk = log_blocks((int)bx + cfg_dx, ((int)by + cfg_dy) & 7);

						tm_index = pCfg_state->m_tm_index;
						actual_cem = cfg_log_blk.m_color_endpoint_modes[0];

						for (uint32_t i = 0; i < cfg_log_blk.m_num_partitions; i++)
							log_blk.m_color_endpoint_modes[i] = (uint8_t)actual_cem;
						log_blk.m_dual_plane = cfg_log_blk.m_dual_plane;
						log_blk.m_color_component_selector = cfg_log_blk.m_color_component_selector;
						log_blk.m_num_partitions = cfg_log_blk.m_num_partitions;
						log_blk.m_partition_id = cfg_log_blk.m_partition_id;
						log_blk.m_endpoint_ise_range = cfg_log_blk.m_endpoint_ise_range;
						log_blk.m_weight_ise_range = cfg_log_blk.m_weight_ise_range;
						log_blk.m_grid_width = cfg_log_blk.m_grid_width;
						log_blk.m_grid_height = cfg_log_blk.m_grid_height;

						const uint32_t total_endpoint_vals = astc_helpers::get_num_cem_values(actual_cem) * log_blk.m_num_partitions;
						memcpy(log_blk.m_endpoints, cfg_log_blk.m_endpoints, total_endpoint_vals);
												
						new_prev_state.m_tm_index = pCfg_state->m_tm_index;
						new_prev_state.m_base_cem_index = pCfg_state->m_base_cem_index; // base cem not including base+ofs, not actual
						new_prev_state.m_subset_index = pCfg_state->m_subset_index;
						new_prev_state.m_ccs_index = pCfg_state->m_ccs_index;
						new_prev_state.m_grid_size = pCfg_state->m_grid_size;
						new_prev_state.m_grid_aniso = pCfg_state->m_grid_aniso;
						new_prev_state.m_used_part_hash = pCfg_state->m_used_part_hash;
						new_prev_state.m_reused_full_cfg = true;

						const bool actual_cem_supports_bc = astc_helpers::cem_supports_bc(actual_cem);
						if (actual_cem_supports_bc)
						{
							new_prev_state.m_first_endpoint_uses_bc = astc_helpers::used_blue_contraction(actual_cem, log_blk.m_endpoints, log_blk.m_endpoint_ise_range);
							assert(new_prev_state.m_first_endpoint_uses_bc == pCfg_state->m_first_endpoint_uses_bc);
						}
					}
					else
					{
						uint32_t reused_full_cfg_model_index = 0;
						if (pLeft_state)
							reused_full_cfg_model_index = pLeft_state->m_reused_full_cfg;
						else
							reused_full_cfg_model_index = 1;

						if (pUpper_state)
							reused_full_cfg_model_index |= pUpper_state->m_reused_full_cfg ? 2 : 0;
						else
							reused_full_cfg_model_index |= 2;

						const uint32_t config_reuse_index = dec.decode_sym(config_reuse_model[reused_full_cfg_model_index]);

						// TODO: Shared with encoder, make global constant
						
						//if (config_reuse_index < ldr_astc_block_encode_image_output::cMaxConfigReuseNeighbors)
						if (config_reuse_index < cMaxConfigReuseNeighbors)
						{
							// 0 = left, 1 = upper, 2 = left-upper
							int cfg_dx = 0, cfg_dy = 0;
							const prev_block_state* pCfg_state = nullptr;

							switch (config_reuse_index)
							{
							case 0: cfg_dx = -1; pCfg_state = pLeft_state; break;
							case 1: cfg_dx = 0; cfg_dy = -1; pCfg_state = pUpper_state; break;
							case 2: cfg_dx = -1; cfg_dy = -1; pCfg_state = pDiag_state; break;
							default: assert(0); break;
							}

							if ((((cfg_dx + (int)bx) < 0) ||
								((cfg_dy + (int)by) < 0)) ||
								(!pCfg_state))
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid config reuse\n");
								return false;
							}

							if (pCfg_state->m_tm_index < 0)
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid config reuse\n");
								return false;
							}

							astc_helpers::log_astc_block& cfg_log_blk = log_blocks((int)bx + cfg_dx, ((int)by + cfg_dy) & 7);

							tm_index = pCfg_state->m_tm_index;
							log_blk.m_partition_id = cfg_log_blk.m_partition_id;
							actual_cem = cfg_log_blk.m_color_endpoint_modes[0];

							new_prev_state.m_tm_index = pCfg_state->m_tm_index;
							new_prev_state.m_base_cem_index = pCfg_state->m_base_cem_index; // base cem not including base+ofs, not actual
							new_prev_state.m_subset_index = pCfg_state->m_subset_index;
							new_prev_state.m_ccs_index = pCfg_state->m_ccs_index;
							new_prev_state.m_grid_size = pCfg_state->m_grid_size;
							new_prev_state.m_grid_aniso = pCfg_state->m_grid_aniso;
							new_prev_state.m_used_part_hash = pCfg_state->m_used_part_hash;
							new_prev_state.m_reused_full_cfg = true;
						}
						else
						{
							// -------------------- Decode full ASTC config
							{
								uint32_t prev_cem_index = astc_helpers::CEM_LDR_RGB_DIRECT;
								uint32_t prev_subset_index = 0, prev_ccs_index = 0, prev_grid_size = 0, prev_grid_aniso = 0;

								if (pPred_state)
								{
									prev_cem_index = pPred_state->m_base_cem_index;
									prev_subset_index = pPred_state->m_subset_index;
									prev_ccs_index = pPred_state->m_ccs_index;
									prev_grid_size = pPred_state->m_grid_size;
									prev_grid_aniso = pPred_state->m_grid_aniso;
								}

								const uint32_t ldrcem_index = cem_to_ldrcem_index(prev_cem_index);

								uint32_t cem_index = dec.decode_sym(cem_index_model[ldrcem_index]);
								uint32_t subset_index = dec.decode_sym(subset_index_model[prev_subset_index]);
								uint32_t ccs_index = dec.decode_sym(ccs_index_model[prev_ccs_index]);
								uint32_t grid_size_index = dec.decode_sym(grid_size_model[prev_grid_size]);
								uint32_t grid_aniso_index = dec.decode_sym(grid_aniso_model[prev_grid_aniso]);

								const basisu::uint_vec& modes = get_tm_candidates(grouped_encoder_trial_modes, cem_index, subset_index, ccs_index, grid_size_index, grid_aniso_index);
								uint32_t submode_index = 0;

								if (modes.size() > 1)
								{
									arith::arith_data_model& submode_model = submode_models[cem_index][subset_index][ccs_index][grid_size_index][grid_aniso_index];
									if (!submode_model.get_num_data_syms())
										submode_model.init(modes.size_u32(), true);

									submode_index = dec.decode_sym(submode_model);
								}

								if (submode_index >= modes.size())
								{
									BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid mode index\n");
									return false;
								}

								tm_index = modes[submode_index];

								new_prev_state.m_tm_index = tm_index;
								new_prev_state.m_base_cem_index = cem_index;
								new_prev_state.m_subset_index = subset_index;
								new_prev_state.m_ccs_index = ccs_index;
								new_prev_state.m_grid_size = grid_size_index;
								new_prev_state.m_grid_aniso = grid_aniso_index;
								new_prev_state.m_reused_full_cfg = false;
							}

							if (tm_index >= encoder_trial_modes.size())
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image: invalid tm_index, decompression failed (file corrupt)\n");
								return false;
							}

							const trial_mode& tm = encoder_trial_modes[tm_index];

							actual_cem = tm.m_cem;
							if ((tm.m_cem == astc_helpers::CEM_LDR_RGB_DIRECT) || (tm.m_cem == astc_helpers::CEM_LDR_RGBA_DIRECT))
							{
								// Decode is_base_ofs bit
								bool is_base_ofs = dec.decode_bit(is_base_ofs_model);
								if (is_base_ofs)
								{
									if (actual_cem == astc_helpers::CEM_LDR_RGB_DIRECT)
										actual_cem = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
									else if (actual_cem == astc_helpers::CEM_LDR_RGBA_DIRECT)
										actual_cem = astc_helpers::CEM_LDR_RGBA_BASE_PLUS_OFFSET;
								}
							}

							if (tm.m_num_parts > 1)
							{
								const uint32_t total_unique_indices = get_total_unique_patterns(astc_block_size_index, tm.m_num_parts);

								uint32_t use_part_model_index = 0;
								if (pLeft_state)
									use_part_model_index = pLeft_state->m_used_part_hash;
								else
									use_part_model_index = 1;
								if (pUpper_state)
									use_part_model_index |= pUpper_state->m_used_part_hash ? 2 : 0;
								else
									use_part_model_index |= 2;

								int* pPart_hash = (tm.m_num_parts == 2) ? part2_hash : part3_hash;

								bool use_part_hash_flag = dec.decode_bit(use_part_hash_model[use_part_model_index]);

								uint32_t unique_pat_index;
								if (!use_part_hash_flag)
								{
									unique_pat_index = dec.decode_truncated_binary(total_unique_indices);
									pPart_hash[part_hash_index(unique_pat_index)] = unique_pat_index;

									new_prev_state.m_used_part_hash = false;
								}
								else
								{
									uint32_t hash_index = dec.decode_sym((tm.m_num_parts == 2) ? part2_hash_index_model : part3_hash_index_model);
									unique_pat_index = pPart_hash[hash_index];

									if ((int)unique_pat_index < 0)
									{
										BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image: invalid hash_index, decompression failed (file corrupt)\n");
										return false;
									}

									new_prev_state.m_used_part_hash = true;
								}

								if (unique_pat_index >= get_total_unique_patterns(astc_block_size_index, tm.m_num_parts))
								{
									BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image: invalid unique_pat_index, decompression failed (file corrupt)\n");
									return false;
								}

								log_blk.m_partition_id = unique_pat_index_to_part_seed(astc_block_size_index, tm.m_num_parts, unique_pat_index);
							}
							else
							{
								new_prev_state.m_used_part_hash = true; // bias to true
							}

						} // if (config_reuse_index < ldr_astc_block_encode_image_output::cMaxConfigReuseNeighbors)

						if (tm_index >= encoder_trial_modes.size())
						{
							BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image: invalid tm_index, decompression failed (file corrupt)\n");
							return false;
						}

						const trial_mode& tm = encoder_trial_modes[tm_index];

						const bool actual_cem_supports_bc = astc_helpers::cem_supports_bc(actual_cem);

						const uint32_t total_endpoint_vals = astc_helpers::get_num_cem_values(actual_cem);

						for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							log_blk.m_color_endpoint_modes[part_iter] = (uint8_t)actual_cem;

						log_blk.m_num_partitions = (uint8_t)tm.m_num_parts;
						log_blk.m_dual_plane = (tm.m_ccs_index >= 0);
						if (log_blk.m_dual_plane)
							log_blk.m_color_component_selector = (uint8_t)tm.m_ccs_index;

						log_blk.m_weight_ise_range = (uint8_t)tm.m_weight_ise_range;
						log_blk.m_endpoint_ise_range = (uint8_t)tm.m_endpoint_ise_range;
						log_blk.m_grid_width = (uint8_t)tm.m_grid_width;
						log_blk.m_grid_height = (uint8_t)tm.m_grid_height;

						// --------------------------------- Decode endpoints
						const bool used_dpcm_endpoints_flag = dec.decode_bit(use_dpcm_endpoints_model);

						if (!used_dpcm_endpoints_flag)
						{
							auto& raw_model = raw_endpoint_models[log_blk.m_endpoint_ise_range - astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE];

							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									log_blk.m_endpoints[part_iter * total_endpoint_vals + val_iter] = (uint8_t)dec.decode_sym(raw_model);
								} // val_iter

							} // part_iter
						}
						else
						{
							// Endpoint DPCM
							const int num_endpoint_levels = astc_helpers::get_ise_levels(log_blk.m_endpoint_ise_range);
							const auto& endpoint_rank_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_rank_to_ISE;
							const auto& endpoint_ise_to_rank = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_rank;

							const uint32_t reuse_delta_index = dec.decode_sym(endpoint_reuse_delta_model);
							const int reuse_bx = (int)bx + basist::astc_6x6_hdr::g_reuse_xy_deltas[reuse_delta_index].m_x;
							const int reuse_by = (int)by + basist::astc_6x6_hdr::g_reuse_xy_deltas[reuse_delta_index].m_y;

							if ((reuse_bx < 0) || (reuse_by < 0) || (reuse_bx >= (int)num_blocks_x) || (reuse_by >= (int)num_blocks_y))
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid reuse delta\n");
								return false;
							}

							const astc_helpers::log_astc_block* pEndpoint_pred_log_blk = &log_blocks(reuse_bx, reuse_by & 7);
							if (pEndpoint_pred_log_blk->m_solid_color_flag_ldr)
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid reuse delta\n");
								return false;
							}

							uint32_t bc_model_index = 0;
							if (pLeft_state)
								bc_model_index = pLeft_state->m_first_endpoint_uses_bc;
							else
								bc_model_index = 1;

							if (pUpper_state)
								bc_model_index |= pUpper_state->m_first_endpoint_uses_bc ? 2 : 0;
							else
								bc_model_index |= 2;

							if (!pEndpoint_pred_log_blk)
							{
								BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Can't use endpoint DPCM here\n");
								return false;
							}

							bool endpoints_use_bc[astc_helpers::MAX_PARTITIONS] = { false };

							if (actual_cem_supports_bc)
							{
								for (uint32_t part_iter = 0; part_iter < log_blk.m_num_partitions; part_iter++)
								{
									endpoints_use_bc[part_iter] = dec.decode_bit(endpoints_use_bc_models[bc_model_index]);
								}
							}

							uint8_t predicted_endpoints[astc_helpers::MAX_PARTITIONS][astc_helpers::MAX_CEM_ENDPOINT_VALS] = { };

							for (uint32_t part_iter = 0; part_iter < log_blk.m_num_partitions; part_iter++)
							{
								const bool always_repack_flag = false;
								bool blue_contraction_clamped_flag = false, base_ofs_clamped_flag = false;

								// Mini-CEM encoder, to cross CEM domains.
								bool conv_status = convert_endpoints_across_cems(
									pEndpoint_pred_log_blk->m_color_endpoint_modes[0], pEndpoint_pred_log_blk->m_endpoint_ise_range, pEndpoint_pred_log_blk->m_endpoints,
									log_blk.m_color_endpoint_modes[0], log_blk.m_endpoint_ise_range, predicted_endpoints[part_iter],
									always_repack_flag,
									endpoints_use_bc[part_iter], false,
									blue_contraction_clamped_flag, base_ofs_clamped_flag);

								if (!conv_status)
								{
									BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Failed predicting endpoints\n");
									return false;
								}
							}

							auto& dpcm_model = dpcm_endpoint_models[log_blk.m_endpoint_ise_range - astc_helpers::FIRST_VALID_ENDPOINT_ISE_RANGE];

							for (uint32_t part_iter = 0; part_iter < tm.m_num_parts; part_iter++)
							{
								for (uint32_t val_iter = 0; val_iter < total_endpoint_vals; val_iter++)
								{
									const uint32_t endpoint_idx = part_iter * total_endpoint_vals + val_iter;

									int delta = (uint8_t)dec.decode_sym(dpcm_model);
									int e_val = basisu::imod(delta + endpoint_ise_to_rank[predicted_endpoints[part_iter][val_iter]], num_endpoint_levels);

									log_blk.m_endpoints[endpoint_idx] = endpoint_rank_to_ise[e_val];

								} // val_iter

							} // part_iter

						} // if (!used_dpcm_endpoints_flag)

						if (actual_cem_supports_bc)
						{
							new_prev_state.m_first_endpoint_uses_bc = astc_helpers::used_blue_contraction(actual_cem, log_blk.m_endpoints, log_blk.m_endpoint_ise_range);
						}

					} // if (mode_index != cMODE_RAW)

					// ----------------------------------- Decode weights
					if (tm_index >= encoder_trial_modes.size())
					{
						BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image: invalid tm_index, decompression failed (file corrupt)\n");
						return false;
					}

					const trial_mode& tm = encoder_trial_modes[tm_index];

					const uint32_t total_planes = (tm.m_ccs_index >= 0) ? 2 : 1;
					const uint32_t total_weights = tm.m_grid_width * tm.m_grid_height;

					uint32_t use_dct_model_index = 0;
					if (use_dct)
					{
						if (pLeft_state)
							use_dct_model_index = pLeft_state->m_used_weight_dct;
						else
							use_dct_model_index = 1;

						if (pUpper_state)
							use_dct_model_index |= pUpper_state->m_used_weight_dct ? 2 : 0;
						else
							use_dct_model_index |= 2;
					}

					bool block_used_dct = false;
					if (use_dct)
						block_used_dct = dec.decode_bit(use_dct_model[use_dct_model_index]);

					if (use_fast_decoding)
					{
						if (block_used_dct)
						{
							new_prev_state.m_used_weight_dct = true;

							const uint32_t num_dc_levels = grid_weight_dct::get_num_weight_dc_levels(log_blk.m_weight_ise_range);
							syms.m_num_dc_levels = num_dc_levels;

							for (uint32_t plane_iter = 0; plane_iter < total_planes; plane_iter++)
							{
								syms.m_coeffs.resize(0);
																
								if (num_dc_levels == DCT_MEAN_LEVELS1)
									syms.m_dc_sym = mean1_bytes.get_bits8();
								else
									syms.m_dc_sym = mean0_bits.get_bits4();

								uint32_t cur_zig_ofs = 1;

								while (cur_zig_ofs < total_weights)
								{
									uint32_t run_len = run_bytes.get_bits8();
									if (run_len == DCT_RUN_LEN_EOB_SYM_INDEX)
										break;

									cur_zig_ofs += run_len;

									if (cur_zig_ofs >= total_weights)
									{
										BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::DCT decode error\n");
										return false;
									}

									int sign = sign_bits.get_bits1();
									int coeff = coeff_bytes.get_bits8() + 1;

									if (sign)
										coeff = -coeff;

									syms.m_coeffs.push_back(dct_syms::coeff(basisu::safe_cast_uint16(run_len), basisu::safe_cast_int16(coeff)));
									cur_zig_ofs++;
								}

								// weight grid IDCT
								if (!grid_dct.decode_block_weights(dct_q, plane_iter, log_blk, nullptr, nullptr, dct_work, &syms))
								{
									BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::DCT decode failed\n");
									return false;
								}

							} // plane_iter
						}
						else
						{
							// Weight grid DPCM (no dependency on other blocks, or between planes, for determinism even when IDCT is used)
							const uint32_t num_weight_levels = astc_helpers::get_ise_levels(log_blk.m_weight_ise_range);
							const auto& weight_rank_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;

							for (uint32_t plane_iter = 0; plane_iter < total_planes; plane_iter++)
							{
								int prev_w = num_weight_levels / 2;

								if (num_weight_levels <= 4)
								{
									for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
									{
										uint32_t r = weight2_bits.get_bits2();

										uint32_t w = r;
										w = basisu::imod(prev_w + r, num_weight_levels);

										prev_w = w;

										log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

									} // weight_iter
								}
								else if (num_weight_levels <= 8)
								{
									for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
									{
										uint32_t r = weight3_bits.get_bits4();

										uint32_t w = r;
										w = basisu::imod(prev_w + r, num_weight_levels);

										prev_w = w;

										log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

									} // weight_iter
								}
								else if (num_weight_levels <= 16)
								{
									for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
									{
										uint32_t r = weight4_bits.get_bits4();

										uint32_t w = r;
										w = basisu::imod(prev_w + r, num_weight_levels);

										prev_w = w;

										log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

									} // weight_iter
								}
								else
								{
									for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
									{
										uint32_t r = weight8_bytes.get_bits8();

										uint32_t w = r;
										w = basisu::imod(prev_w + r, num_weight_levels);

										prev_w = w;

										log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

									} // weight_iter
								}

							} // plane_iter

						} // if (block_used_dct)
					}
					else
					{
						if (block_used_dct)
						{
							new_prev_state.m_used_weight_dct = true;
														
							const uint32_t num_dc_levels = grid_weight_dct::get_num_weight_dc_levels(log_blk.m_weight_ise_range);
							syms.m_num_dc_levels = num_dc_levels;

							for (uint32_t plane_iter = 0; plane_iter < total_planes; plane_iter++)
							{
								syms.m_coeffs.resize(0);

								syms.m_dc_sym = dec.decode_sym(weight_mean_models[(num_dc_levels == DCT_MEAN_LEVELS1) ? 1 : 0]);

								uint32_t cur_zig_ofs = 1;

								while (cur_zig_ofs < total_weights)
								{
									uint32_t run_len = dec.decode_sym(dct_run_len_model);
									if (run_len == DCT_RUN_LEN_EOB_SYM_INDEX)
										break;

									cur_zig_ofs += run_len;

									if (cur_zig_ofs >= total_weights)
									{
										BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::DCT decode error\n");
										return false;
									}

									int sign = dec.get_bit();
									int coeff = dec.decode_sym(dct_coeff_mag) + 1;

									if (sign)
										coeff = -coeff;

									syms.m_coeffs.push_back(dct_syms::coeff(basisu::safe_cast_uint16(run_len), basisu::safe_cast_int16(coeff)));
									cur_zig_ofs++;
								}

								// weight grid IDCT
								if (!grid_dct.decode_block_weights(dct_q, plane_iter, log_blk, nullptr, nullptr, dct_work, &syms))
								{
									BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::DCT decode failed\n");
									return false;
								}

							} // plane_iter
						}
						else
						{
							// Weight grid DPCM (no dependency on other blocks, or between planes, for determinism even when IDCT is used)
							const uint32_t num_weight_levels = astc_helpers::get_ise_levels(log_blk.m_weight_ise_range);
							const auto& weight_rank_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;

							for (uint32_t plane_iter = 0; plane_iter < total_planes; plane_iter++)
							{
								int prev_w = num_weight_levels / 2;

								for (uint32_t weight_iter = 0; weight_iter < total_weights; weight_iter++)
								{
									uint32_t r = dec.decode_sym(raw_weight_models[log_blk.m_weight_ise_range - astc_helpers::FIRST_VALID_WEIGHT_ISE_RANGE]);

									uint32_t w = r;
									w = basisu::imod(prev_w + r, num_weight_levels);

									prev_w = w;

									log_blk.m_weights[plane_iter + weight_iter * total_planes] = (uint8_t)weight_rank_to_ise[w];

								} // weight_iter

							} // plane_iter
						}

					} // use_fast_decoding

					if (pBlock_callback)
					{
						if (!(*pBlock_callback)(bx, by, log_blk, pBlock_callback_data))
							return false;
					}

					break;
				}
				default:
				{
					BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Invalid mode\n");
					return false;
				}
				}

			} // bx

			assert(!cur_run_len);

		} // by

		//if (debug_output)
		//	debug_printf("Decomp time: {3.3}ms\n", itm.get_elapsed_ms());

		const uint32_t final_sync_marker = dec.get_bits(FINAL_SYNC_MARKER_BITS);
		if (final_sync_marker != FINAL_SYNC_MARKER)
		{
			BASISU_DEVEL_ERROR("astc_ldr_t::decompress_image::Final sync failed\n");
			return false;
		}

		if (debug_output)
			basisu::debug_printf("astc_ldr_t::decompress_image: Decode sync OK\n");

		return true;
	}

} // namespace astc_ldr_t

#endif // #if BASISD_SUPPORT_XUASTC

#if BASISD_SUPPORT_XUASTC

namespace bc7u
{
	//------------------------------------------------------------------------------------------------
	// BC7 mode 0-7 decompression.
	// Instead of one monster routine to unpack all the BC7 modes, we're lumping the 3 subset, 2 subset, 1 subset, and dual plane modes together into simple shared routines.

	static inline uint32_t bc7_dequant(uint32_t val, uint32_t pbit, uint32_t val_bits) { assert(val < (1U << val_bits)); assert(pbit < 2); assert(val_bits >= 4 && val_bits <= 8); const uint32_t total_bits = val_bits + 1; val = (val << 1) | pbit; val <<= (8 - total_bits); val |= (val >> total_bits); assert(val <= 255); return val; }
	static inline uint32_t bc7_dequant(uint32_t val, uint32_t val_bits) { assert(val < (1U << val_bits)); assert(val_bits >= 4 && val_bits <= 8); val <<= (8 - val_bits); val |= (val >> val_bits); assert(val <= 255); return val; }

	static inline uint32_t bc7_interp2(uint32_t l, uint32_t h, uint32_t w) { assert(w < 4); return (l * (64 - basist::g_bc7_weights2[w]) + h * basist::g_bc7_weights2[w] + 32) >> 6; }
	static inline uint32_t bc7_interp3(uint32_t l, uint32_t h, uint32_t w) { assert(w < 8); return (l * (64 - basist::g_bc7_weights3[w]) + h * basist::g_bc7_weights3[w] + 32) >> 6; }
	static inline uint32_t bc7_interp4(uint32_t l, uint32_t h, uint32_t w) { assert(w < 16); return (l * (64 - basist::g_bc7_weights4[w]) + h * basist::g_bc7_weights4[w] + 32) >> 6; }
	static inline uint32_t bc7_interp(uint32_t l, uint32_t h, uint32_t w, uint32_t bits)
	{
		assert(l <= 255 && h <= 255);
		switch (bits)
		{
		case 2: return bc7_interp2(l, h, w);
		case 3: return bc7_interp3(l, h, w);
		case 4: return bc7_interp4(l, h, w);
		default:
			break;
		}
		return 0;
	}

	inline uint32_t read_bits32(const uint8_t* pBuf, uint32_t& bit_offset, uint32_t codesize)
	{
		assert(codesize <= 32);
		uint32_t bits = 0;
		uint32_t total_bits = 0;

		while (total_bits < codesize)
		{
			uint32_t byte_bit_offset = bit_offset & 7;
			uint32_t bits_to_read = basisu::minimum<int>(codesize - total_bits, 8 - byte_bit_offset);

			uint32_t byte_bits = pBuf[bit_offset >> 3] >> byte_bit_offset;
			byte_bits &= ((1 << bits_to_read) - 1);

			bits |= (byte_bits << total_bits);

			total_bits += bits_to_read;
			bit_offset += bits_to_read;
		}

		return bits;
	}

	bool unpack_bc7_mode0_2(uint32_t mode, const void* pBlock_bits, color_rgba* pPixels)
	{
		//const uint32_t SUBSETS = 3;
		const uint32_t ENDPOINTS = 6;
		const uint32_t COMPS = 3;
		const uint32_t WEIGHT_BITS = (mode == 0) ? 3 : 2;
		const uint32_t ENDPOINT_BITS = (mode == 0) ? 4 : 5;
		const uint32_t PBITS = (mode == 0) ? 6 : 0;
		const uint32_t WEIGHT_VALS = 1 << WEIGHT_BITS;

		uint32_t bit_offset = 0;
		const uint8_t* pBuf = static_cast<const uint8_t*>(pBlock_bits);

		if (read_bits32(pBuf, bit_offset, mode + 1) != (1U << mode)) return false;

		const uint32_t part = read_bits32(pBuf, bit_offset, (mode == 0) ? 4 : 6);

		color_rgba endpoints[ENDPOINTS];
		for (uint32_t c = 0; c < COMPS; c++)
			for (uint32_t e = 0; e < ENDPOINTS; e++)
				endpoints[e][c] = (uint8_t)read_bits32(pBuf, bit_offset, ENDPOINT_BITS);

		uint32_t pbits[6];
		for (uint32_t p = 0; p < PBITS; p++)
			pbits[p] = read_bits32(pBuf, bit_offset, 1);

		uint32_t weights[16];
		for (uint32_t i = 0; i < 16; i++)
			weights[i] = read_bits32(pBuf, bit_offset, ((!i) || (i == basist::g_bc7_table_anchor_index_third_subset_1[part]) || (i == basist::g_bc7_table_anchor_index_third_subset_2[part])) ? (WEIGHT_BITS - 1) : WEIGHT_BITS);

		assert(bit_offset == 128);

		for (uint32_t e = 0; e < ENDPOINTS; e++)
			for (uint32_t c = 0; c < 4; c++)
				endpoints[e][c] = (uint8_t)((c == 3) ? 255 : (PBITS ? bc7_dequant(endpoints[e][c], pbits[e], ENDPOINT_BITS) : bc7_dequant(endpoints[e][c], ENDPOINT_BITS)));

		color_rgba block_colors[3][8];
		for (uint32_t s = 0; s < 3; s++)
			for (uint32_t i = 0; i < WEIGHT_VALS; i++)
			{
				for (uint32_t c = 0; c < 3; c++)
					block_colors[s][i][c] = (uint8_t)bc7_interp(endpoints[s * 2 + 0][c], endpoints[s * 2 + 1][c], i, WEIGHT_BITS);
				block_colors[s][i][3] = 255;
			}

		for (uint32_t i = 0; i < 16; i++)
			pPixels[i] = block_colors[basist::g_bc7_partition3[part * 16 + i]][weights[i]];

		return true;
	}

	bool unpack_bc7_mode1_3_7(uint32_t mode, const void* pBlock_bits, color_rgba* pPixels)
	{
		//const uint32_t SUBSETS = 2;
		const uint32_t ENDPOINTS = 4;
		const uint32_t COMPS = (mode == 7) ? 4 : 3;
		const uint32_t WEIGHT_BITS = (mode == 1) ? 3 : 2;
		const uint32_t ENDPOINT_BITS = (mode == 7) ? 5 : ((mode == 1) ? 6 : 7);
		const uint32_t PBITS = (mode == 1) ? 2 : 4;
		const uint32_t SHARED_PBITS = (mode == 1) ? true : false;
		const uint32_t WEIGHT_VALS = 1 << WEIGHT_BITS;

		uint32_t bit_offset = 0;
		const uint8_t* pBuf = static_cast<const uint8_t*>(pBlock_bits);

		if (read_bits32(pBuf, bit_offset, mode + 1) != (1U << mode)) return false;

		const uint32_t part = read_bits32(pBuf, bit_offset, 6);

		color_rgba endpoints[ENDPOINTS];
		for (uint32_t c = 0; c < COMPS; c++)
			for (uint32_t e = 0; e < ENDPOINTS; e++)
				endpoints[e][c] = (uint8_t)read_bits32(pBuf, bit_offset, ENDPOINT_BITS);

		uint32_t pbits[4];
		for (uint32_t p = 0; p < PBITS; p++)
			pbits[p] = read_bits32(pBuf, bit_offset, 1);

		uint32_t weights[16];
		for (uint32_t i = 0; i < 16; i++)
			weights[i] = read_bits32(pBuf, bit_offset, ((!i) || (i == basist::g_bc7_table_anchor_index_second_subset[part])) ? (WEIGHT_BITS - 1) : WEIGHT_BITS);

		assert(bit_offset == 128);

		for (uint32_t e = 0; e < ENDPOINTS; e++)
			for (uint32_t c = 0; c < 4; c++)
				endpoints[e][c] = (uint8_t)((c == ((mode == 7U) ? 4U : 3U)) ? 255 : bc7_dequant(endpoints[e][c], pbits[SHARED_PBITS ? (e >> 1) : e], ENDPOINT_BITS));

		color_rgba block_colors[2][8];
		for (uint32_t s = 0; s < 2; s++)
			for (uint32_t i = 0; i < WEIGHT_VALS; i++)
			{
				for (uint32_t c = 0; c < COMPS; c++)
					block_colors[s][i][c] = (uint8_t)bc7_interp(endpoints[s * 2 + 0][c], endpoints[s * 2 + 1][c], i, WEIGHT_BITS);
				block_colors[s][i][3] = (COMPS == 3) ? 255 : block_colors[s][i][3];
			}

		for (uint32_t i = 0; i < 16; i++)
			pPixels[i] = block_colors[basist::g_bc7_partition2[part * 16 + i]][weights[i]];

		return true;
	}
		
	bool unpack_bc7_mode4_5(uint32_t mode, const void* pBlock_bits, color_rgba* pPixels)
	{
		const uint32_t ENDPOINTS = 2;
		const uint32_t COMPS = 4;
		const uint32_t WEIGHT_BITS = 2;
		const uint32_t A_WEIGHT_BITS = (mode == 4) ? 3 : 2;
		const uint32_t ENDPOINT_BITS = (mode == 4) ? 5 : 7;
		const uint32_t A_ENDPOINT_BITS = (mode == 4) ? 6 : 8;
		//const uint32_t WEIGHT_VALS = 1 << WEIGHT_BITS;
		//const uint32_t A_WEIGHT_VALS = 1 << A_WEIGHT_BITS;

		uint32_t bit_offset = 0;
		const uint8_t* pBuf = static_cast<const uint8_t*>(pBlock_bits);

		if (read_bits32(pBuf, bit_offset, mode + 1) != (1U << mode)) return false;

		const uint32_t comp_rot = read_bits32(pBuf, bit_offset, 2);
		const uint32_t index_mode = (mode == 4) ? read_bits32(pBuf, bit_offset, 1) : 0;

		color_rgba endpoints[ENDPOINTS];
		for (uint32_t c = 0; c < COMPS; c++)
			for (uint32_t e = 0; e < ENDPOINTS; e++)
				endpoints[e][c] = (uint8_t)read_bits32(pBuf, bit_offset, (c == 3) ? A_ENDPOINT_BITS : ENDPOINT_BITS);

		const uint32_t weight_bits[2] = { index_mode ? A_WEIGHT_BITS : WEIGHT_BITS,  index_mode ? WEIGHT_BITS : A_WEIGHT_BITS };

		uint32_t weights[16], a_weights[16];

		for (uint32_t i = 0; i < 16; i++)
			(index_mode ? a_weights : weights)[i] = read_bits32(pBuf, bit_offset, weight_bits[index_mode] - ((!i) ? 1 : 0));

		for (uint32_t i = 0; i < 16; i++)
			(index_mode ? weights : a_weights)[i] = read_bits32(pBuf, bit_offset, weight_bits[1 - index_mode] - ((!i) ? 1 : 0));

		assert(bit_offset == 128);

		for (uint32_t e = 0; e < ENDPOINTS; e++)
			for (uint32_t c = 0; c < 4; c++)
				endpoints[e][c] = (uint8_t)bc7_dequant(endpoints[e][c], (c == 3) ? A_ENDPOINT_BITS : ENDPOINT_BITS);

		color_rgba block_colors[8];
		for (uint32_t i = 0; i < (1U << weight_bits[0]); i++)
			for (uint32_t c = 0; c < 3; c++)
				block_colors[i][c] = (uint8_t)bc7_interp(endpoints[0][c], endpoints[1][c], i, weight_bits[0]);

		for (uint32_t i = 0; i < (1U << weight_bits[1]); i++)
			block_colors[i][3] = (uint8_t)bc7_interp(endpoints[0][3], endpoints[1][3], i, weight_bits[1]);

		for (uint32_t i = 0; i < 16; i++)
		{
			pPixels[i] = block_colors[weights[i]];
			pPixels[i].a = block_colors[a_weights[i]].a;
			if (comp_rot >= 1)
				std::swap(pPixels[i].a, pPixels[i].m_comps[comp_rot - 1]);
		}

		return true;
	}

	struct bc7_mode_6
	{
		struct
		{
			uint64_t m_mode : 7;
			uint64_t m_r0 : 7;
			uint64_t m_r1 : 7;
			uint64_t m_g0 : 7;
			uint64_t m_g1 : 7;
			uint64_t m_b0 : 7;
			uint64_t m_b1 : 7;
			uint64_t m_a0 : 7;
			uint64_t m_a1 : 7;
			uint64_t m_p0 : 1;
		} m_lo;

		union
		{
			struct
			{
				uint64_t m_p1 : 1;
				uint64_t m_s00 : 3;
				uint64_t m_s10 : 4;
				uint64_t m_s20 : 4;
				uint64_t m_s30 : 4;

				uint64_t m_s01 : 4;
				uint64_t m_s11 : 4;
				uint64_t m_s21 : 4;
				uint64_t m_s31 : 4;

				uint64_t m_s02 : 4;
				uint64_t m_s12 : 4;
				uint64_t m_s22 : 4;
				uint64_t m_s32 : 4;

				uint64_t m_s03 : 4;
				uint64_t m_s13 : 4;
				uint64_t m_s23 : 4;
				uint64_t m_s33 : 4;

			} m_hi;

			uint64_t m_hi_bits;
		};
	};

	bool unpack_bc7_mode6(const void* pBlock_bits, color_rgba* pPixels)
	{
		static_assert(sizeof(bc7_mode_6) == 16, "sizeof(bc7_mode_6) == 16");

		const bc7_mode_6& block = *static_cast<const bc7_mode_6*>(pBlock_bits);

		if (block.m_lo.m_mode != (1 << 6))
			return false;

		const uint32_t r0 = (uint32_t)((block.m_lo.m_r0 << 1) | block.m_lo.m_p0);
		const uint32_t g0 = (uint32_t)((block.m_lo.m_g0 << 1) | block.m_lo.m_p0);
		const uint32_t b0 = (uint32_t)((block.m_lo.m_b0 << 1) | block.m_lo.m_p0);
		const uint32_t a0 = (uint32_t)((block.m_lo.m_a0 << 1) | block.m_lo.m_p0);
		const uint32_t r1 = (uint32_t)((block.m_lo.m_r1 << 1) | block.m_hi.m_p1);
		const uint32_t g1 = (uint32_t)((block.m_lo.m_g1 << 1) | block.m_hi.m_p1);
		const uint32_t b1 = (uint32_t)((block.m_lo.m_b1 << 1) | block.m_hi.m_p1);
		const uint32_t a1 = (uint32_t)((block.m_lo.m_a1 << 1) | block.m_hi.m_p1);

		color_rgba vals[16];
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t w = basist::g_bc7_weights4[i];
			const uint32_t iw = 64 - w;
			vals[i].set_noclamp_rgba(
				(r0 * iw + r1 * w + 32) >> 6,
				(g0 * iw + g1 * w + 32) >> 6,
				(b0 * iw + b1 * w + 32) >> 6,
				(a0 * iw + a1 * w + 32) >> 6);
		}

		pPixels[0] = vals[block.m_hi.m_s00];
		pPixels[1] = vals[block.m_hi.m_s10];
		pPixels[2] = vals[block.m_hi.m_s20];
		pPixels[3] = vals[block.m_hi.m_s30];

		pPixels[4] = vals[block.m_hi.m_s01];
		pPixels[5] = vals[block.m_hi.m_s11];
		pPixels[6] = vals[block.m_hi.m_s21];
		pPixels[7] = vals[block.m_hi.m_s31];

		pPixels[8] = vals[block.m_hi.m_s02];
		pPixels[9] = vals[block.m_hi.m_s12];
		pPixels[10] = vals[block.m_hi.m_s22];
		pPixels[11] = vals[block.m_hi.m_s32];

		pPixels[12] = vals[block.m_hi.m_s03];
		pPixels[13] = vals[block.m_hi.m_s13];
		pPixels[14] = vals[block.m_hi.m_s23];
		pPixels[15] = vals[block.m_hi.m_s33];

		return true;
	}

	int determine_bc7_mode(const void* pBlock)
	{
		const uint32_t b = static_cast<const uint8_t*>(pBlock)[0];

		if (!b) 
			return -1;

#if defined(_MSC_VER)
		unsigned long idx;
		_BitScanForward(&idx, b);
		return (int)idx;
#else
		return __builtin_ctz(b);
#endif
	}

	int determine_bc7_mode_4_index_mode(const void* pBlock)
	{
		const uint32_t first_byte = static_cast<const uint8_t*>(pBlock)[0];

		// check for mode 4
		if ((first_byte & 31) != 0b10000)
			return -1;

		return (first_byte >> 7);
	}

	int determine_bc7_mode_4_or_5_rotation(const void* pBlock)
	{
		const uint32_t first_byte = static_cast<const uint8_t*>(pBlock)[0];
		if ((first_byte & 31) == 0b10000)
		{
			// mode 4
			return (first_byte >> 5) & 3;
		}

		if ((first_byte & 63) == 0b100000)
		{
			// mode 5
			return first_byte >> 6;
		}

		return -1;
	}

	bool unpack_bc7(const void* pBlock, color_rgba* pPixels)
	{
		const uint32_t first_byte = static_cast<const uint8_t*>(pBlock)[0];

		for (uint32_t mode = 0; mode <= 7; mode++)
		{
			if (first_byte & (1U << mode))
			{
				switch (mode)
				{
				case 0:
				case 2:
					return unpack_bc7_mode0_2(mode, pBlock, pPixels);
				case 1:
				case 3:
				case 7:
					return unpack_bc7_mode1_3_7(mode, pBlock, pPixels);
				case 4:
				case 5:
					return unpack_bc7_mode4_5(mode, pBlock, pPixels);
				case 6:
					return unpack_bc7_mode6(pBlock, pPixels);
				default:
					break;
				}
			}
		}

		return false;
	}
			
} // namespace bc7u

// BASISU_BC7F_USE_SSE41 - only very minimally tested. Needs more testing and more variants. Only improves transcoding perf by ~10% in native so far.
#define BASISU_BC7F_USE_SSE41 (0)
#define BASISU_BC7F_PERF_STATS (0)

namespace bc7f
{
	const uint32_t MAX_PATTERNS2_TO_CHECK = 64;
	const uint32_t MAX_PATTERNS3_TO_CHECK = 64;

	const float UNIQUE_PBIT_DISCOUNT = .85f;
	const float SHARED_PBIT_DISCOUNT = .95f;

	//static inline uint8_t mul_8(uint32_t v, uint32_t q) { v = v * q + 128; return (uint8_t)((v + (v >> 8)) >> 8); }
	//static inline int mul_8bit(int a, int b) { int t = a * b + 128; return (t + (t >> 8)) >> 8; }
	//static inline int lerp_8bit(int a, int b, int s) { assert(a >= 0 && a <= 255); assert(b >= 0 && b <= 255); assert(s >= 0 && s <= 255); return a + mul_8bit(b - a, s); }

	static int popcount32(uint32_t x)
	{
#if defined(__EMSCRIPTEN__) || defined(__clang__) || defined(__GNUC__)
		return __builtin_popcount(x);
#elif defined(_MSC_VER)
		return __popcnt(x);
#else
		int count = 0;
		while (x)
		{
			x &= (x - 1);
			++count;
		}
		return count;
#endif
	}

#if BASISU_BC7F_PERF_STATS
	// not thread safe (no need/for dev)
	uint32_t g_total_rgb_calls;
	uint32_t g_total_rgba_calls;
	uint32_t g_total_solid_blocks;

	uint32_t g_total_trivial_mode6_blocks;

	uint32_t g_total_dp_valid_chans_rgb;
	uint32_t g_total_dp_valid_chans_a;
	uint32_t g_total_high_ortho_energy;

	uint32_t g_total_mode02_evals;
	uint32_t g_total_mode02_bailouts;

	uint32_t g_total_mode13_evals;
	uint32_t g_total_mode13_bailouts;

	uint32_t g_total_mode45_evals;
	uint32_t g_total_mode45_bailouts;

	uint32_t g_total_mode7_evals;
	uint32_t g_total_mode7_bailouts;
#endif

	inline int fast_roundf_pos_int(float x)
	{
		assert(x >= 0.0f);
		return (int)(x + 0.5f);
	}

	inline int fast_roundf_int(float x)
	{
		return (x >= 0.0f) ? (int)(x + 0.5f) : (int)(x - 0.5f);
	}

	inline int fast_floorf_int(float x)
	{
		int xi = (int)x;  // Truncate towards zero
		return ((x < 0.0f) && (x != (float)xi)) ? (xi - 1) : xi;
	}

	static inline uint32_t from_7(uint32_t v)
	{
		assert(v < 128);
		return (v << 1) | (v >> 6);
	}

	static inline uint32_t from_7(uint32_t v, uint32_t p)
	{
		assert((v < 128) && (p <= 1));
		return (v << 1) | p;
	}

	static inline int to_7(int c8, int pbit)
	{
		assert((c8 >= 0) && (c8 <= 255) && (pbit >= 0) && (pbit <= 1));
		uint32_t e = (uint32_t(c8) + uint32_t(pbit ^ 1)) >> 1;
		return basisu::minimum<uint32_t>(127, e);
	}

	static inline int to_7(int c8)
	{
		assert((c8 >= 0) && (c8 <= 255));
		return (c8 * 127 + 127) / 255;
	}

	static inline int to_7(float c, int pbit)
	{
		assert((c >= 0) && (c <= 255.0f));
		return to_7(fast_roundf_pos_int(c), pbit);
	}

	static inline int to_7_clamp(float c, int pbit)
	{
		return to_7(basisu::clamp<int>(fast_roundf_int(c), 0, 255), pbit);
	}

	static inline int to_5(int c8)
	{
		assert((c8 >= 0) && (c8 <= 255));
		return (c8 * 31 + 127) / 255;
	}

	static inline int to_5_clamp(float c)
	{
		return basisu::clamp<int>(fast_roundf_int(c * (31.0f / 255.0f)), 0, 31);
	}

	static inline int to_6(int c8)
	{
		assert((c8 >= 0) && (c8 <= 255));
		return (c8 * 63 + 127) / 255;
	}

	static inline int to_6(int c8, int pbit)
	{
		assert((c8 >= 0) && (c8 <= 255));
		assert((pbit == 0) || (pbit == 1));

		int q7 = (c8 * 127 + 127) / 255;

		if ((q7 & 1) != pbit)
		{
			const int lhs = c8 * 127;
			const int rhs = 255 * q7;

			if (lhs >= rhs)
			{
				q7 = (q7 < 127) ? (q7 + 1) : (q7 - 1);
			}
			else
			{
				q7 = (q7 > 0) ? (q7 - 1) : (q7 + 1);
			}
		}

		return q7 >> 1;
	}

	static inline int to_6_clamp(float c, int pbit)
	{
		return to_6(basisu::clamp<int>(fast_roundf_int(c), 0, 255), pbit);
	}

	static inline uint32_t from_6(uint32_t v, uint32_t p)
	{
		assert((v < 64) && (p <= 1));
		v = (v << 1) | p;
		v = (v << 1) | (v >> 6);
		return v;
	}

	static inline uint32_t from_4(uint32_t v, uint32_t p)
	{
		assert((v < 16) && (p <= 1));
		v = (v << 1) | p;
		v = (v << 3) | (v >> 2);
		return v;
	}

	static inline uint32_t from_5(uint32_t v)
	{
		assert(v < 32);
		v = (v << 3) | (v >> 2);
		return v;
	}

	static inline uint32_t from_5(uint32_t v, uint32_t p)
	{
		assert((v < 32) && (p <= 1));
		v = (v << 1) | p;
		v = (v << 2) | (v >> 4);
		return v;
	}

	static inline uint32_t from_6(uint32_t v)
	{
		assert(v < 64);
		v = (v << 2) | (v >> 4);
		return v;
	}

	static inline int to_5(int c8, int pbit)
	{
		assert((c8 >= 0) && (c8 <= 255));
		assert((pbit == 0) || (pbit == 1));

		int q6 = (c8 * 63 + 127) / 255;

		if ((q6 & 1) != pbit)
		{
			const int lhs = c8 * 63;
			const int rhs = 255 * q6;

			if (lhs >= rhs)
			{
				q6 = (q6 < 63) ? (q6 + 1) : (q6 - 1);
			}
			else
			{
				q6 = (q6 > 0) ? (q6 - 1) : (q6 + 1);
			}
		}

		return q6 >> 1;
	}

#if 0
	static inline int to_5(float c, int pbit)
	{
		assert((c >= 0.0f) && (c <= 255.0f));
		return to_5((int)fast_roundf_pos_int(c), pbit);
	}
#endif

	static inline int to_5_clamp(float c, uint32_t pbit)
	{
		return to_5(basisu::clamp<int>(fast_roundf_int(c), 0, 255), pbit);
	}

	//static inline uint32_t bc7_interp(uint32_t l, uint32_t h, uint32_t w) { assert(w <= 64); return (l * (64 - w) + h * w + 32) >> 6; }
	//static inline uint32_t bc7_interp2(uint32_t l, uint32_t h, uint32_t w) { assert(w <= 64); int d = h - l; return (int)l + ((d * (int)w + 32) >> 6); }
	//static inline uint32_t bc7_interp3(int l, int d, uint32_t w) { assert(w <= 64); return l + ((d * (int)w + 32) >> 6); }

	static vec4F g_bc7_2bit_ls_tab[4];
	static vec4F g_bc7_3bit_ls_tab[8];
	static vec4F g_bc7_4bit_ls_tab[16];
	static uint16_t g_bc7_part2_bitmasks[64];
	static uint32_t g_part3_bitmasks[64];

	void init()
	{
		for (uint32_t i = 0; i < 4; i++)
		{
			float w = (float)basist::g_bc7_weights2[i] * (1.0f / 64.0f);
			g_bc7_2bit_ls_tab[i].set(w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w);
		}

		for (uint32_t i = 0; i < 8; i++)
		{
			float w = (float)basist::g_bc7_weights3[i] * (1.0f / 64.0f);
			g_bc7_3bit_ls_tab[i].set(w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w);
		}

		for (uint32_t i = 0; i < 16; i++)
		{
			float w = (float)basist::g_bc7_weights4[i] * (1.0f / 64.0f);
			g_bc7_4bit_ls_tab[i].set(w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w);
		}

		for (uint32_t i = 0; i < 64; i++)
		{
			uint16_t y = 0;

			for (uint32_t x = 0; x < 16; x++)
				y |= (g_bc7_partition2[i * 16 + x] << x);

			g_bc7_part2_bitmasks[i] = y;
		}

		for (uint32_t i = 0; i < 64; i++)
		{
			const uint8_t* pPat = &g_bc7_partition3[i * 16];

			for (uint32_t j = 0; j < 16; j++)
			{
				const uint32_t s = pPat[j];

				if (s == 0)
					g_part3_bitmasks[i] |= (1 << j);
				else if (s == 1)
					g_part3_bitmasks[i] |= (0x10000 << j);
			}
		}
	}

	void encode_mode0_rgb_block(uint8_t* pBlock, uint32_t part_id, // 3 subsets, 4-bits part ID
		uint32_t lr[3], uint32_t lg[3], uint32_t lb[3], // 4 bit endpoints
		uint32_t hr[3], uint32_t hg[3], uint32_t hb[3],
		uint32_t p[6],
		const uint8_t* pWeights) // 3-bit weights
	{
		assert(part_id < 16);
		assert((lr[0] | lr[1] | lr[2] | lg[0] | lg[1] | lg[2] | lb[0] | lb[1] | lb[2]) <= 15);
		assert((hr[0] | hr[1] | hr[2] | hg[0] | hg[1] | hg[2] | hb[0] | hb[1] | hb[2]) <= 15);
		assert((p[0] | p[1] | p[2] | p[3] | p[4] | p[5]) <= 1);

		const uint8_t* pPart_map = &g_bc7_partition3[part_id * 16];
		const uint32_t anchor_index0 = g_bc7_table_anchor_index_third_subset_1[part_id];
		const uint32_t anchor_index1 = g_bc7_table_anchor_index_third_subset_2[part_id];

		uint32_t weight_inv[3] = { 0, 0, 0 };

		if (pWeights[0] & 4)
		{
			std::swap(lr[0], hr[0]);
			std::swap(lg[0], hg[0]);
			std::swap(lb[0], hb[0]);
			std::swap(p[0], p[1]);
			weight_inv[0] = 7;
		}

		if (pWeights[anchor_index0] & 4)
		{
			std::swap(lr[1], hr[1]);
			std::swap(lg[1], hg[1]);
			std::swap(lb[1], hb[1]);
			std::swap(p[2], p[3]);
			weight_inv[1] = 7;
		}

		if (pWeights[anchor_index1] & 4)
		{
			std::swap(lr[2], hr[2]);
			std::swap(lg[2], hg[2]);
			std::swap(lb[2], hb[2]);
			std::swap(p[4], p[5]);
			weight_inv[2] = 7;
		}

		uint64_t low = 1ULL | ((part_id) << 1) |
			((lr[0]) << 5) | ((hr[0]) << 9) |
			((lr[1]) << 13) | ((hr[1]) << 17) |
			((lr[2]) << 21) | ((hr[2]) << 25) |
			(uint64_t(lg[0]) << 29) | (uint64_t(hg[0]) << 33) |
			(uint64_t(lg[1]) << 37) | (uint64_t(hg[1]) << 41) |
			(uint64_t(lg[2]) << 45) | (uint64_t(hg[2]) << 49) |
			(uint64_t(lb[0]) << 53) | (uint64_t(hb[0]) << 57) |
			(uint64_t(lb[1]) << 61);

		pBlock[0] = (uint8_t)low;
		pBlock[1] = (uint8_t)(low >> 8);
		pBlock[2] = (uint8_t)(low >> 16);
		pBlock[3] = (uint8_t)(low >> 24);
		pBlock[4] = (uint8_t)(low >> 32);
		pBlock[5] = (uint8_t)(low >> 40);
		pBlock[6] = (uint8_t)(low >> 48);
		pBlock[7] = (uint8_t)(low >> 56);

		uint64_t high = (lb[1] >> 3) | ((hb[1]) << 1) | ((lb[2]) << 5) | ((hb[2]) << 9) |
			((p[0]) << 13) | ((p[1]) << 14) | ((p[2]) << 15) | ((p[3]) << 16) | ((p[4]) << 17) | ((p[5]) << 18);

		uint32_t ofs = 19;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];
			uint64_t w = pWeights[i] ^ weight_inv[subset_index];

#ifdef _DEBUG
			assert(w <= 7);
			if ((i == 0) || (i == anchor_index0) || (i == anchor_index1))
			{
				assert((w & 4) == 0);
			}
#endif

			high |= (w << ofs);
			ofs += (3 - ((i == 0) || (i == anchor_index0) || (i == anchor_index1)));
		}
		assert(64 == ofs);

		pBlock[8] = (uint8_t)high;
		pBlock[9] = (uint8_t)(high >> 8);
		pBlock[10] = (uint8_t)(high >> 16);
		pBlock[11] = (uint8_t)(high >> 24);
		pBlock[12] = (uint8_t)(high >> 32);
		pBlock[13] = (uint8_t)(high >> 40);
		pBlock[14] = (uint8_t)(high >> 48);
		pBlock[15] = (uint8_t)(high >> 56);
	}

	void encode_mode1_rgb_block(uint8_t* pBlock, uint32_t part_id, // 2 subsets, 6-bits part ID
		uint32_t lr[2], uint32_t lg[2], uint32_t lb[2], // 6-bit endpoints, 2 shared pbits
		uint32_t hr[2], uint32_t hg[2], uint32_t hb[2],
		uint32_t p0, uint32_t p1,
		const uint8_t* pWeights) // 3-bit weights
	{
		assert(part_id < 64);
		assert((lr[0] | lr[1] | lg[0] | lg[1] | lb[0] | lb[1]) <= 63);
		assert((hr[0] | hr[1] | hg[0] | hg[1] | hb[0] | hb[1]) <= 63);
		assert((p0 | p1) <= 1);

		const uint8_t* pPart_map = &g_bc7_partition2[part_id * 16];
		const uint32_t anchor_index = g_bc7_table_anchor_index_second_subset[part_id];

		uint32_t weight_inv[2] = { 0, 0 };
		if (pWeights[0] & 4)
		{
			std::swap(lr[0], hr[0]);
			std::swap(lg[0], hg[0]);
			std::swap(lb[0], hb[0]);
			weight_inv[0] = 7;
		}

		if (pWeights[anchor_index] & 4)
		{
			std::swap(lr[1], hr[1]);
			std::swap(lg[1], hg[1]);
			std::swap(lb[1], hb[1]);
			weight_inv[1] = 7;
		}

		pBlock[0] = (uint8_t)(0b10 | (part_id << 2));

		uint64_t x = lr[0] | (hr[0] << (6 * 1));
		x |= (lr[1] << (6 * 2)) | (hr[1] << (6 * 3));

		x |= (lg[0] << (6 * 4)) | (uint64_t(hg[0]) << (6 * 5));
		x |= (uint64_t(lg[1]) << (6 * 6)) | (uint64_t(hg[1]) << (6 * 7));

		x |= (uint64_t(lb[0]) << (6 * 8)) | (uint64_t(hb[0]) << (6 * 9));
		x |= (uint64_t(lb[1]) << (6 * 10));

		// 11*6=66 bits total, write first 64

		pBlock[1] = (uint8_t)x;
		pBlock[2] = (uint8_t)(x >> 8);
		pBlock[3] = (uint8_t)(x >> 16);
		pBlock[4] = (uint8_t)(x >> 24);

		pBlock[5] = (uint8_t)(x >> 32);
		pBlock[6] = (uint8_t)(x >> 40);
		pBlock[7] = (uint8_t)(x >> 48);
		pBlock[8] = (uint8_t)(x >> 56);

		pBlock[9] = (uint8_t)((lb[1] >> 4) | (hb[1] << 2));

		uint64_t y = p0 | (p1 << 1);
		uint32_t ofs = 2;

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];

			uint64_t w = pWeights[i] ^ weight_inv[subset_index];

#ifdef _DEBUG
			assert(w <= 7);
			if ((i == 0) || (i == anchor_index))
			{
				assert((w & 4) == 0);
			}
#endif
			y |= (w << ofs);

			ofs += (3 - ((i == 0) || (i == anchor_index)));
		}
		assert(48 == ofs);

		pBlock[10] = (uint8_t)y;
		pBlock[11] = (uint8_t)(y >> 8);
		pBlock[12] = (uint8_t)(y >> 16);
		pBlock[13] = (uint8_t)(y >> 24);
		pBlock[14] = (uint8_t)(y >> 32);
		pBlock[15] = (uint8_t)(y >> 40);
	}

	void encode_mode2_rgb_block(uint8_t* pBlock, uint32_t part_id, // 3 subsets, 6-bits part ID
		uint32_t lr[3], uint32_t lg[3], uint32_t lb[3], // 5 bit endpoints, no pbits
		uint32_t hr[3], uint32_t hg[3], uint32_t hb[3],
		const uint8_t* pWeights) // 2-bit weights
	{
		assert(part_id < 64);
		assert((lr[0] | lr[1] | lr[2] | lg[0] | lg[1] | lg[2] | lb[0] | lb[1] | lb[2]) <= 31);
		assert((hr[0] | hr[1] | hr[2] | hg[0] | hg[1] | hg[2] | hb[0] | hb[1] | hb[2]) <= 31);

		const uint8_t* pPart_map = &g_bc7_partition3[part_id * 16];

		uint32_t weight_inv[3] = { 0 };
		if (pWeights[0] & 2)
		{
			std::swap(lr[0], hr[0]);
			std::swap(lg[0], hg[0]);
			std::swap(lb[0], hb[0]);
			weight_inv[0] = 3;
		}

		const uint32_t anchor_index0 = g_bc7_table_anchor_index_third_subset_1[part_id];
		if (pWeights[anchor_index0] & 2)
		{
			std::swap(lr[1], hr[1]);
			std::swap(lg[1], hg[1]);
			std::swap(lb[1], hb[1]);
			weight_inv[1] = 3;
		}

		const uint32_t anchor_index1 = g_bc7_table_anchor_index_third_subset_2[part_id];
		if (pWeights[anchor_index1] & 2)
		{
			std::swap(lr[2], hr[2]);
			std::swap(lg[2], hg[2]);
			std::swap(lb[2], hb[2]);
			weight_inv[2] = 3;
		}

		uint64_t v = 0b100 | (part_id << 3);
		v |= (lr[0] << 9) | (hr[0] << (9 + 5 * 1));
		v |= (lr[1] << (9 + 5 * 2)) | (hr[1] << (9 + 5 * 3));
		v |= (uint64_t(lr[2]) << (9 + 5 * 4)) | (uint64_t(hr[2]) << (9 + 5 * 5));

		v |= (uint64_t(lg[0]) << (9 + 5 * 6)) | (uint64_t(hg[0]) << (9 + 5 * 7));
		v |= (uint64_t(lg[1]) << (9 + 5 * 8)) | (uint64_t(hg[1]) << (9 + 5 * 9));
		v |= (uint64_t(lg[2]) << (9 + 5 * 10));

		pBlock[0] = (uint8_t)v;
		pBlock[1] = (uint8_t)(v >> 8);
		pBlock[2] = (uint8_t)(v >> 16);
		pBlock[3] = (uint8_t)(v >> 24);
		pBlock[4] = (uint8_t)(v >> 32);
		pBlock[5] = (uint8_t)(v >> 40);
		pBlock[6] = (uint8_t)(v >> 48);
		pBlock[7] = (uint8_t)(v >> 56);

		uint64_t v1 = hg[2];
		v1 |= (lb[0] << (5 * 1)) | (hb[0] << (5 * 2));
		v1 |= (lb[1] << (5 * 3)) | (hb[1] << (5 * 4));
		v1 |= (lb[2] << (5 * 5)) | (uint64_t(hb[2]) << (5 * 6));

		pBlock[8] = (uint8_t)(v1);
		pBlock[9] = (uint8_t)(v1 >> 8);
		pBlock[10] = (uint8_t)(v1 >> 16);
		pBlock[11] = (uint8_t)(v1 >> 24);

		v1 >>= 32;

		// 3 bits left over
		uint32_t ofs = 3;

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];

			uint64_t w = pWeights[i] ^ weight_inv[subset_index];

#ifdef _DEBUG
			assert(w <= 3);
			if ((i == 0) || (i == anchor_index0) || (i == anchor_index1))
			{
				assert((w & 2) == 0);
			}
#endif
			v1 |= (w << ofs);

			ofs += (2 - ((i == 0) || (i == anchor_index0) || (i == anchor_index1)));
		}
		assert(32 == ofs);

		pBlock[12] = (uint8_t)v1;
		pBlock[13] = (uint8_t)(v1 >> 8);
		pBlock[14] = (uint8_t)(v1 >> 16);
		pBlock[15] = (uint8_t)(v1 >> 24);
	}

	void encode_mode3_rgb_block(uint8_t* pBlock, uint32_t part_id, // 2 subsets, 6-bits part ID
		uint32_t lr[2], uint32_t lg[2], uint32_t lb[2], // 7-bit endpoints, 4 unique pbits
		uint32_t hr[2], uint32_t hg[2], uint32_t hb[2],
		uint32_t p[4],
		const uint8_t* pWeights) // 2-bit weights
	{
		assert(part_id < 64);
		assert((lr[0] | lr[1] | lg[0] | lg[1] | lb[0] | lb[1]) <= 127);
		assert((hr[0] | hr[1] | hg[0] | hg[1] | hb[0] | hb[1]) <= 127);
		assert((p[0] | p[1] | p[2] | p[3]) <= 1);

		const uint8_t* pPart_map = &g_bc7_partition2[part_id * 16];
		const uint32_t anchor_index = g_bc7_table_anchor_index_second_subset[part_id];

		uint32_t weight_inv[2] = { 0, 0 };
		if (pWeights[0] & 2)
		{
			std::swap(lr[0], hr[0]);
			std::swap(lg[0], hg[0]);
			std::swap(lb[0], hb[0]);
			std::swap(p[0], p[1]);
			weight_inv[0] = 3;
		}

		if (pWeights[anchor_index] & 2)
		{
			std::swap(lr[1], hr[1]);
			std::swap(lg[1], hg[1]);
			std::swap(lb[1], hb[1]);
			std::swap(p[2], p[3]);
			weight_inv[1] = 3;
		}

		uint64_t x = 0b1000 | (part_id << 4) |
			(lr[0] << 10) | (hr[0] << 17) |
			(lr[1] << 24) | (uint64_t(hr[1]) << 31) |
			(uint64_t(lg[0]) << 38) | (uint64_t(hg[0]) << 45) |
			(uint64_t(lg[1]) << 52) | (uint64_t(hg[1]) << 59);

		pBlock[0] = (uint8_t)x;
		pBlock[1] = (uint8_t)(x >> 8);
		pBlock[2] = (uint8_t)(x >> 16);
		pBlock[3] = (uint8_t)(x >> 24);
		pBlock[4] = (uint8_t)(x >> 32);
		pBlock[5] = (uint8_t)(x >> 40);
		pBlock[6] = (uint8_t)(x >> 48);
		pBlock[7] = (uint8_t)(x >> 56);

		// 2 bits of hg[1] remaining to pack

		uint64_t y = (hg[1] >> 5) | (lb[0] << 2) | (hb[0] << 9) |
			(lb[1] << (9 + 7 * 1)) | (hb[1] << (9 + 7 * 2)) |
			(uint64_t(p[0]) << (9 + 7 * 3)) | (uint64_t(p[1]) << (9 + 7 * 3 + 1)) |
			(uint64_t(p[2]) << (9 + 7 * 3 + 2)) | (uint64_t(p[3]) << (9 + 7 * 3 + 3));

		// now 34 total bits

		uint32_t ofs = 34;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];
			uint64_t w = pWeights[i] ^ weight_inv[subset_index];

#ifdef _DEBUG
			assert(w <= 3);
			if ((i == 0) || (i == anchor_index))
			{
				assert((w & 2) == 0);
			}
#endif

			y |= (w << ofs);
			ofs += (2 - ((i == 0) || (i == anchor_index)));
		}
		assert(64 == ofs);

		pBlock[8] = (uint8_t)y;
		pBlock[9] = (uint8_t)(y >> 8);
		pBlock[10] = (uint8_t)(y >> 16);
		pBlock[11] = (uint8_t)(y >> 24);
		pBlock[12] = (uint8_t)(y >> 32);
		pBlock[13] = (uint8_t)(y >> 40);
		pBlock[14] = (uint8_t)(y >> 48);
		pBlock[15] = (uint8_t)(y >> 56);
	}

	void encode_mode4_rgba_block(uint8_t* pBlock,
		uint32_t lr, uint32_t lg, uint32_t lb, uint32_t la, // 5-bit RGB endpoints, 6-bit A endpoints, no p-bits
		uint32_t hr, uint32_t hg, uint32_t hb, uint32_t ha,
		const uint8_t* pWeights0, const uint8_t* pWeights1, // weights0=rgb weights1=alpha, index_flag controls which ones are 2 or 3 bits, for 0 it's 2-bit RGB/3-bit alpha
		uint32_t rot_index, uint32_t index_flag) // rot_index=0 no rotation, if index_flag is 1, the 3-bit indices are for RGB
	{
		assert((lr | lg | lb | hr | hg | hb) <= 31);
		assert((la | ha) <= 63);
		assert(rot_index <= 3);
		assert(index_flag <= 1);

		// defaults: 2nd plane=always alpha, RGB=3-bit indices, A=2-bits (favoring RGB)
		//const uint32_t rot_index = 0, index_flag = 1;

		uint32_t weights_inv[2] = { };

		const uint8_t* p2BitWeights = index_flag ? pWeights1 : pWeights0;
		const uint8_t* p3BitWeights = index_flag ? pWeights0 : pWeights1;

		// 3-bits
		if (p3BitWeights[0] & 4)
		{
			weights_inv[0] = 7;
			if (index_flag)
			{
				std::swap(lr, hr);
				std::swap(lg, hg);
				std::swap(lb, hb);
			}
			else
			{
				std::swap(la, ha);
			}
		}

		// 2-bits
		if (p2BitWeights[0] & 2)
		{
			weights_inv[1] = 3;
			if (index_flag)
			{
				std::swap(la, ha);
			}
			else
			{
				std::swap(lr, hr);
				std::swap(lg, hg);
				std::swap(lb, hb);
			}
		}

		pBlock[0] = (uint8_t)(0b10000 | (rot_index << 5) | (index_flag << 7));

		// 6*5+6*2=42 bits
		uint64_t x = lr | (hr << (5 * 1));
		x |= (lg << (5 * 2)) | (hg << (5 * 3));
		x |= (lb << (5 * 4)) | (hb << (5 * 5));
		x |= (uint64_t(la) << (5 * 6)) | (uint64_t(ha) << (5 * 6 + 6));

		pBlock[1] = (uint8_t)x;
		pBlock[2] = (uint8_t)(x >> 8);
		pBlock[3] = (uint8_t)(x >> 16);
		pBlock[4] = (uint8_t)(x >> 24);

		pBlock[5] = (uint8_t)(x >> 32);

		// 2 leftover bits
		x >>= 40;
		uint32_t ofs0 = 2;

		// alpha indices (2-bits)
		for (uint32_t i = 0; i < 16; i++)
		{
			assert(p2BitWeights[i] <= 3);
			uint64_t w = p2BitWeights[i] ^ weights_inv[1];

			assert(i || ((w & 2) == 0));

			x |= (w << ofs0);

			ofs0 += 2 - (i == 0);
		}

		// x = 31+2=33 bits

		pBlock[6] = (uint8_t)x;
		pBlock[7] = (uint8_t)(x >> 8);
		pBlock[8] = (uint8_t)(x >> 16);
		pBlock[9] = (uint8_t)(x >> 24);

		x >>= 32;

		// x = 1 bits
		uint32_t ofs1 = 1;

		// rgb indices (3-bits)
		for (uint32_t i = 0; i < 16; i++)
		{
			assert(p3BitWeights[i] <= 7);
			uint64_t w = p3BitWeights[i] ^ weights_inv[0];

			assert(i || ((w & 4) == 0));

			x |= (w << ofs1);

			ofs1 += 3 - (i == 0);
		}

		assert(ofs1 == 48);

		// x=48 bits
		pBlock[10] = (uint8_t)x;
		pBlock[11] = (uint8_t)(x >> 8);
		pBlock[12] = (uint8_t)(x >> 16);
		pBlock[13] = (uint8_t)(x >> 24);
		pBlock[14] = (uint8_t)(x >> 32);
		pBlock[15] = (uint8_t)(x >> 40);
	}

	// lossless in RGBA
	void pack_mode5_solid(uint8_t* pBlock, const color_rgba& c)
	{
		pBlock[0] = 0b00100000;

		uint32_t lr = basist::g_bc7_mode_5_optimal_endpoints[c[0]].m_lo;
		uint32_t hr = basist::g_bc7_mode_5_optimal_endpoints[c[0]].m_hi;

		uint32_t lg = basist::g_bc7_mode_5_optimal_endpoints[c[1]].m_lo;
		uint32_t hg = basist::g_bc7_mode_5_optimal_endpoints[c[1]].m_hi;

		uint32_t lb = basist::g_bc7_mode_5_optimal_endpoints[c[2]].m_lo;
		uint32_t hb = basist::g_bc7_mode_5_optimal_endpoints[c[2]].m_hi;

		// 8 endpoints are 8-bits, nothing fancy needed
		uint32_t a = c[3];

		// 58 total bits
		uint64_t x = lr | (hr << (7 * 1));
		x |= (lg << (7 * 2)) | (hg << (7 * 3));
		x |= (((uint64_t)lb) << (7 * 4)) | (((uint64_t)hb) << (7 * 5));
		x |= (((uint64_t)a) << (7 * 6)) | (((uint64_t)a) << (7 * 6 + 8));

		// write 56 bits, leaving 2 left over
		pBlock[1] = (uint8_t)(x);
		pBlock[2] = (uint8_t)(x >> 8);
		pBlock[3] = (uint8_t)(x >> 16);
		pBlock[4] = (uint8_t)(x >> 24);
		pBlock[5] = (uint8_t)(x >> 32);
		pBlock[6] = (uint8_t)(x >> 40);
		pBlock[7] = (uint8_t)(x >> 48);

		x >>= 56;
		assert(x <= 3);

#if 0
		x |= (0b0101010101010101010101010101011ull << 2);

		pBlock[8] = (uint8_t)(x);
		pBlock[9] = (uint8_t)(x >> 8);
		pBlock[10] = (uint8_t)(x >> 16);
		pBlock[11] = (uint8_t)(x >> 24);
		pBlock[12] = (uint8_t)(x >> 32);
		pBlock[13] = 0;
		pBlock[14] = 0;
		pBlock[15] = 0;
#elif 0
		// 0xaaaaaaac | x
		pBlock[8] = (uint8_t)(x) | 0xAC;

		static const uint8_t s_tail_bytes[7] = { 0xaa, 0xaa, 0xaa, 0, 0, 0, 0 };
		memcpy(pBlock + 9, s_tail_bytes, 7);
#elif 1
		static const uint8_t s_tail_bytes[8] = { 0xac, 0xaa, 0xaa, 0xaa, 0, 0, 0, 0 };
		memcpy(pBlock + 8, s_tail_bytes, 8);
		pBlock[8] |= (uint8_t)x;
#endif
	}

	void encode_mode5_rgba_block(uint8_t* pBlock,
		uint32_t lr, uint32_t lg, uint32_t lb, uint32_t la, // 7-bit RGB endpoints, 8-bit alpha endpoints
		uint32_t hr, uint32_t hg, uint32_t hb, uint32_t ha,
		const uint8_t* pColorWeights, const uint8_t* pAlphaWeights, // both 2-bit weights
		uint32_t rot_index = 0) // rot_index=0 no rotation
	{
		assert((lr | lg | lb | hr | hg | hb) <= 127);
		assert((la | ha) <= 255);
		assert(rot_index <= 3);

		uint32_t color_inv = 0, alpha_inv = 0;

		if (pColorWeights[0] & 2)
		{
			std::swap(lr, hr);
			std::swap(lg, hg);
			std::swap(lb, hb);
			color_inv = 3;
		}

		if (pAlphaWeights[0] & 2)
		{
			std::swap(la, ha);
			alpha_inv = 3;
		}

		uint64_t low = (1ULL << 5) | (rot_index << 6) |
			(lr << 8) | (hr << 15) |
			(lg << 22) | (uint64_t(hg) << 29) |
			(uint64_t(lb) << 36) | (uint64_t(hb) << 43) |
			(uint64_t(la) << 50) | (uint64_t(ha) << 58);

		pBlock[0] = (uint8_t)low;
		pBlock[1] = (uint8_t)(low >> 8);
		pBlock[2] = (uint8_t)(low >> 16);
		pBlock[3] = (uint8_t)(low >> 24);
		pBlock[4] = (uint8_t)(low >> 32);
		pBlock[5] = (uint8_t)(low >> 40);
		pBlock[6] = (uint8_t)(low >> 48);
		pBlock[7] = (uint8_t)(low >> 56);

		uint64_t high = (ha >> 6) & 3;

		uint32_t ofs = 2;

		for (uint32_t i = 0; i < 16; i++)
		{
			uint64_t w = pColorWeights[i] ^ color_inv;
#ifdef _DEBUG
			assert(w <= 3);
			if (i == 0)
			{
				assert((w & 2) == 0);
			}
#endif    
			high |= (w << ofs);
			ofs += (2 - (i == 0));
		}

		assert(33 == ofs);

		for (uint32_t i = 0; i < 16; i++)
		{
			uint64_t w = pAlphaWeights[i] ^ alpha_inv;
#ifdef _DEBUG
			assert(w <= 3);
			if (i == 0)
			{
				assert((w & 2) == 0);
			}
#endif    
			high |= (w << ofs);
			ofs += (2 - (i == 0));
		}

		assert(64 == ofs);

		pBlock[8] = (uint8_t)high;
		pBlock[9] = (uint8_t)(high >> 8);
		pBlock[10] = (uint8_t)(high >> 16);
		pBlock[11] = (uint8_t)(high >> 24);
		pBlock[12] = (uint8_t)(high >> 32);
		pBlock[13] = (uint8_t)(high >> 40);
		pBlock[14] = (uint8_t)(high >> 48);
		pBlock[15] = (uint8_t)(high >> 56);
	}

	void encode_mode6_rgba_block(uint8_t* pBlock,
		uint32_t lr, uint32_t lg, uint32_t lb, uint32_t la, uint32_t p0, // 7-bit endpoints, 2 shared p-bits
		uint32_t hr, uint32_t hg, uint32_t hb, uint32_t ha, uint32_t p1,
		const uint8_t* pWeights) // 4-bit weights
	{
		assert((lr | lg | lb | la | hr | hg | hb | ha) <= 127);
		assert((p0 | p1) <= 1);

		uint32_t weight_inv = 0;
		if (pWeights[0] & 8)
		{
			std::swap(lr, hr);
			std::swap(lg, hg);
			std::swap(lb, hb);
			std::swap(la, ha);
			std::swap(p0, p1);
			weight_inv = 15;
		}

		// 9*7=63 bits
		uint64_t x = 0b1000000 | (lr << (7 * 1)) | (hr << (7 * 2));
		x |= (lg << (7 * 3)) | (uint64_t(hg) << (7 * 4));
		x |= (uint64_t(lb) << (7 * 5)) | (uint64_t(hb) << (7 * 6));
		x |= (uint64_t(la) << (7 * 7)) | (uint64_t(ha) << (7 * 8));

		pBlock[0] = (uint8_t)x;
		pBlock[1] = (uint8_t)(x >> 8);
		pBlock[2] = (uint8_t)(x >> 16);
		pBlock[3] = (uint8_t)(x >> 24);

		pBlock[4] = (uint8_t)(x >> 32);
		pBlock[5] = (uint8_t)(x >> 40);
		pBlock[6] = (uint8_t)(x >> 48);
		x >>= 56;

		// x=7 bits
		x |= (p0 << 7);
		pBlock[7] = (uint8_t)x;

		uint64_t y = p1;
		uint32_t ofs = 1;
		// TODO: Unroll/optimize
		for (uint32_t i = 0; i < 16; i++)
		{
			uint64_t w = pWeights[i] ^ weight_inv;
			assert(w <= 15);
			assert(i || ((w & 8) == 0));
			y |= (w << ofs);
			ofs += 3 + (i > 0);
		}
		assert(64 == ofs);

		pBlock[8] = (uint8_t)y;
		pBlock[9] = (uint8_t)(y >> 8);
		pBlock[10] = (uint8_t)(y >> 16);
		pBlock[11] = (uint8_t)(y >> 24);
		pBlock[12] = (uint8_t)(y >> 32);
		pBlock[13] = (uint8_t)(y >> 40);
		pBlock[14] = (uint8_t)(y >> 48);
		pBlock[15] = (uint8_t)(y >> 56);
	}

	void encode_mode7_rgba_block(uint8_t* pBlock, uint32_t part_id, // 2 subsets, 6-bits part ID
		uint32_t lr[2], uint32_t lg[2], uint32_t lb[2], uint32_t la[2], // 5-bit endpoints, unique pbits
		uint32_t hr[2], uint32_t hg[2], uint32_t hb[2], uint32_t ha[2],
		uint32_t p[4],
		const uint8_t* pWeights) // 2-bit weights
	{
		assert(part_id < 64);
		assert((lr[0] | lr[1] | lg[0] | lg[1] | lb[0] | lb[1] | la[0] | la[1]) <= 31);
		assert((hr[0] | hr[1] | hg[0] | hg[1] | hb[0] | hb[1] | ha[0] | ha[1]) <= 31);
		assert((p[0] | p[1] | p[2] | p[3]) <= 1);

		const uint8_t* pPart_map = &g_bc7_partition2[part_id * 16];
		const uint32_t anchor_index = g_bc7_table_anchor_index_second_subset[part_id];

		uint32_t weight_inv[2] = { 0, 0 };
		if (pWeights[0] & 2)
		{
			std::swap(lr[0], hr[0]); std::swap(lg[0], hg[0]); std::swap(lb[0], hb[0]); std::swap(la[0], ha[0]);
			std::swap(p[0], p[1]);
			weight_inv[0] = 3;
		}

		if (pWeights[anchor_index] & 2)
		{
			std::swap(lr[1], hr[1]); std::swap(lg[1], hg[1]); std::swap(lb[1], hb[1]); std::swap(la[1], ha[1]);
			std::swap(p[2], p[3]);
			weight_inv[1] = 3;
		}

		uint64_t x = 0x80ULL | (part_id << 8) |
			(lr[0] << 14) | (hr[0] << 19) | (lr[1] << 24) | (uint64_t(hr[1]) << 29) |
			(uint64_t(lg[0]) << 34) | (uint64_t(hg[0]) << 39) | (uint64_t(lg[1]) << 44) | (uint64_t(hg[1]) << 49) |
			(uint64_t(lb[0]) << 54) | (uint64_t(hb[0]) << 59);

		pBlock[0] = (uint8_t)x;
		pBlock[1] = (uint8_t)(x >> 8);
		pBlock[2] = (uint8_t)(x >> 16);
		pBlock[3] = (uint8_t)(x >> 24);

		pBlock[4] = (uint8_t)(x >> 32);
		pBlock[5] = (uint8_t)(x >> 40);
		pBlock[6] = (uint8_t)(x >> 48);
		pBlock[7] = (uint8_t)(x >> 56);

		uint64_t y = (lb[1] << 0) | (hb[1] << 5) |
			(la[0] << 10) | (ha[0] << 15) | (la[1] << 20) | (ha[1] << 25) |
			(uint64_t(p[0]) << 30) | (uint64_t(p[1]) << 31) | (uint64_t(p[2]) << 32) | (uint64_t(p[3]) << 33);

		uint32_t ofs = 34;
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];
			uint64_t w = pWeights[i] ^ weight_inv[subset_index];

#ifdef _DEBUG
			assert(w <= 3);
			if ((i == 0) || (i == anchor_index))
			{
				assert((w & 2) == 0);
			}
#endif

			y |= (w << ofs);
			ofs += (2 - ((i == 0) || (i == anchor_index)));
		}
		assert(64 == ofs);

		pBlock[8] = (uint8_t)y;
		pBlock[9] = (uint8_t)(y >> 8);
		pBlock[10] = (uint8_t)(y >> 16);
		pBlock[11] = (uint8_t)(y >> 24);

		pBlock[12] = (uint8_t)(y >> 32);
		pBlock[13] = (uint8_t)(y >> 40);
		pBlock[14] = (uint8_t)(y >> 48);
		pBlock[15] = (uint8_t)(y >> 56);
	}
		
	static bool compute_least_squares_endpoints_1D(
		uint32_t N, const uint8_t* pWeights, uint32_t num_weights,
		const vec4F* pSelector_weights,
		float& xl, float& xh,
		const color_rgba* pColors, uint32_t comp_index,
		float t_r)
	{
		BASISU_NOTE_UNUSED(num_weights);

		float z00 = 0.0f, z10 = 0.0f, z11 = 0.0f;
		float q00_r = 0.0f;

		for (uint32_t i = 0; i < N; i++)
		{
			const uint32_t sel = pWeights[i];
			assert(sel < num_weights);

			z00 += pSelector_weights[sel][0];
			z10 += pSelector_weights[sel][1];
			z11 += pSelector_weights[sel][2];

			const float w = pSelector_weights[sel][3];

			q00_r += w * (float)pColors[i][comp_index];
		}

		float q10_r = t_r - q00_r;

		float z01 = z10;

		float det = z00 * z11 - z01 * z10;
		if (fabs(det) < 1e-8f)
			return false;

		det = 1.0f / det;

		float iz00, iz01, iz10, iz11;
		iz00 = z11 * det;
		iz01 = -z01 * det;
		iz10 = -z10 * det;
		iz11 = z00 * det;

		xh = basisu::clamp(iz00 * q00_r + iz01 * q10_r, 0.0f, 255.0f);
		xl = basisu::clamp(iz10 * q00_r + iz11 * q10_r, 0.0f, 255.0f);

		return true;
	}

	static bool compute_least_squares_endpoints_3D(
		uint32_t N, const uint8_t* pWeights, uint32_t num_weights,
		const vec4F* pSelector_weights,
		vec4F& xl, vec4F& xh,
		const color_rgba* pColors,
		float t_r, float t_g, float t_b)
	{
		BASISU_NOTE_UNUSED(num_weights);

		float z00 = 0.0f, z10 = 0.0f, z11 = 0.0f;
		float q00_r = 0.0f, q00_g = 0.0f, q00_b = 0.0f;

		for (uint32_t i = 0; i < N; i++)
		{
			const uint32_t sel = pWeights[i];
			assert(sel < num_weights);

			z00 += pSelector_weights[sel][0];
			z10 += pSelector_weights[sel][1];
			z11 += pSelector_weights[sel][2];

			const float w = pSelector_weights[sel][3];

			q00_r += w * (float)pColors[i][0];
			q00_g += w * (float)pColors[i][1];
			q00_b += w * (float)pColors[i][2];
		}

		float q10_r = t_r - q00_r;
		float q10_g = t_g - q00_g;
		float q10_b = t_b - q00_b;

		float z01 = z10;

		float det = z00 * z11 - z01 * z10;
		if (fabs(det) < 1e-8f)
			return false;

		det = 1.0f / det;

		float iz00, iz01, iz10, iz11;
		iz00 = z11 * det;
		iz01 = -z01 * det;
		iz10 = -z10 * det;
		iz11 = z00 * det;

		xh[0] = basisu::clamp(iz00 * q00_r + iz01 * q10_r, 0.0f, 255.0f);
		xl[0] = basisu::clamp(iz10 * q00_r + iz11 * q10_r, 0.0f, 255.0f);

		xh[1] = basisu::clamp(iz00 * q00_g + iz01 * q10_g, 0.0f, 255.0f);
		xl[1] = basisu::clamp(iz10 * q00_g + iz11 * q10_g, 0.0f, 255.0f);

		xh[2] = basisu::clamp(iz00 * q00_b + iz01 * q10_b, 0.0f, 255.0f);
		xl[2] = basisu::clamp(iz10 * q00_b + iz11 * q10_b, 0.0f, 255.0f);

		xh[3] = 0;
		xl[3] = 0;

		return true;
	}

	static bool compute_least_squares_endpoints_4D(
		uint32_t N, const uint8_t* pWeights, uint32_t num_weights,
		const vec4F* pSelector_weights,
		vec4F& xl, vec4F& xh,
		const color_rgba* pColors,
		float t_r, float t_g, float t_b, float t_a)
	{
		BASISU_NOTE_UNUSED(num_weights);

		float z00 = 0.0f, z10 = 0.0f, z11 = 0.0f;
		float q00_r = 0.0f, q00_g = 0.0f, q00_b = 0.0f, q00_a = 0.0f;

		for (uint32_t i = 0; i < N; i++)
		{
			const uint32_t sel = pWeights[i];
			assert(sel < num_weights);

			z00 += pSelector_weights[sel][0];
			z10 += pSelector_weights[sel][1];
			z11 += pSelector_weights[sel][2];

			const float w = pSelector_weights[sel][3];

			q00_r += w * (float)pColors[i][0];
			q00_g += w * (float)pColors[i][1];
			q00_b += w * (float)pColors[i][2];
			q00_a += w * (float)pColors[i][3];
		}

		float q10_r = t_r - q00_r;
		float q10_g = t_g - q00_g;
		float q10_b = t_b - q00_b;
		float q10_a = t_a - q00_a;

		float z01 = z10;

		float det = z00 * z11 - z01 * z10;
		if (fabs(det) < 1e-8f)
			return false;

		det = 1.0f / det;

		float iz00, iz01, iz10, iz11;
		iz00 = z11 * det;
		iz01 = -z01 * det;
		iz10 = -z10 * det;
		iz11 = z00 * det;

		xh[0] = basisu::clamp(iz00 * q00_r + iz01 * q10_r, 0.0f, 255.0f);
		xl[0] = basisu::clamp(iz10 * q00_r + iz11 * q10_r, 0.0f, 255.0f);

		xh[1] = basisu::clamp(iz00 * q00_g + iz01 * q10_g, 0.0f, 255.0f);
		xl[1] = basisu::clamp(iz10 * q00_g + iz11 * q10_g, 0.0f, 255.0f);

		xh[2] = basisu::clamp(iz00 * q00_b + iz01 * q10_b, 0.0f, 255.0f);
		xl[2] = basisu::clamp(iz10 * q00_b + iz11 * q10_b, 0.0f, 255.0f);

		xh[3] = basisu::clamp(iz00 * q00_a + iz01 * q10_a, 0.0f, 255.0f);
		xl[3] = basisu::clamp(iz10 * q00_a + iz11 * q10_a, 0.0f, 255.0f);

		return true;
	}

#if BASISU_BC7F_USE_SSE41
	void bc7_proj_minmax_indices_sse41(const color_rgba* __restrict pPixels, int saxis_r, int saxis_g, int saxis_b, int* out_min_idx, int* out_max_idx)
	{
		__m128i coef32 = _mm_setr_epi32(saxis_r, saxis_g, saxis_b, 0);     // 32-bit lanes
		coef32 = _mm_srai_epi32(coef32, 4);                                // arithmetic >>4 in 32-bit
		__m128i COEF = _mm_packs_epi32(coef32, coef32);

		const __m128i ZERO = _mm_setzero_si128();

		__m128i vmin, vmax;
		{
			const __m128i px = _mm_loadu_si128((const __m128i*) & pPixels[0]);
			const __m128i lo16 = _mm_unpacklo_epi8(px, ZERO);  // [r0 g0 b0 a0 r1 g1 b1 a1]
			const __m128i hi16 = _mm_unpackhi_epi8(px, ZERO);  // [r2 g2 b2 a2 r3 g3 b3 a3]

			const __m128i lo32p = _mm_madd_epi16(lo16, COEF);
			const __m128i hi32p = _mm_madd_epi16(hi16, COEF);

			const __m128i lo_sum = _mm_add_epi32(lo32p, _mm_shuffle_epi32(lo32p, _MM_SHUFFLE(2, 3, 0, 1)));
			const __m128i hi_sum = _mm_add_epi32(hi32p, _mm_shuffle_epi32(hi32p, _MM_SHUFFLE(2, 3, 0, 1)));

			const __m128i pair01 = _mm_shuffle_epi32(lo_sum, _MM_SHUFFLE(2, 0, 2, 0));
			const __m128i pair23 = _mm_shuffle_epi32(hi_sum, _MM_SHUFFLE(2, 0, 2, 0));

			const __m128i p32p = _mm_unpacklo_epi64(pair01, pair23);

			const __m128i p32 = _mm_slli_epi32(p32p, 4);

			const __m128i keyed = _mm_add_epi32(p32, _mm_set_epi32(3, 2, 1, 0));

			vmin = keyed;
			vmax = keyed;
		}

		{
			const __m128i px = _mm_loadu_si128((const __m128i*) & pPixels[4]);
			const __m128i lo16 = _mm_unpacklo_epi8(px, ZERO);  // [r0 g0 b0 a0 r1 g1 b1 a1]
			const __m128i hi16 = _mm_unpackhi_epi8(px, ZERO);  // [r2 g2 b2 a2 r3 g3 b3 a3]

			const __m128i lo32p = _mm_madd_epi16(lo16, COEF);
			const __m128i hi32p = _mm_madd_epi16(hi16, COEF);

			const __m128i lo_sum = _mm_add_epi32(lo32p, _mm_shuffle_epi32(lo32p, _MM_SHUFFLE(2, 3, 0, 1)));
			const __m128i hi_sum = _mm_add_epi32(hi32p, _mm_shuffle_epi32(hi32p, _MM_SHUFFLE(2, 3, 0, 1)));

			const __m128i pair01 = _mm_shuffle_epi32(lo_sum, _MM_SHUFFLE(2, 0, 2, 0));
			const __m128i pair23 = _mm_shuffle_epi32(hi_sum, _MM_SHUFFLE(2, 0, 2, 0));

			const __m128i p32p = _mm_unpacklo_epi64(pair01, pair23);

			const __m128i p32 = _mm_slli_epi32(p32p, 4);

			const __m128i keyed = _mm_add_epi32(p32, _mm_set_epi32(7, 6, 5, 4));

			vmin = _mm_min_epi32(vmin, keyed);
			vmax = _mm_max_epi32(vmax, keyed);
		}

		{
			const __m128i px = _mm_loadu_si128((const __m128i*) & pPixels[8]);
			const __m128i lo16 = _mm_unpacklo_epi8(px, ZERO);  // [r0 g0 b0 a0 r1 g1 b1 a1]
			const __m128i hi16 = _mm_unpackhi_epi8(px, ZERO);  // [r2 g2 b2 a2 r3 g3 b3 a3]

			const __m128i lo32p = _mm_madd_epi16(lo16, COEF);
			const __m128i hi32p = _mm_madd_epi16(hi16, COEF);

			const __m128i lo_sum = _mm_add_epi32(lo32p, _mm_shuffle_epi32(lo32p, _MM_SHUFFLE(2, 3, 0, 1)));
			const __m128i hi_sum = _mm_add_epi32(hi32p, _mm_shuffle_epi32(hi32p, _MM_SHUFFLE(2, 3, 0, 1)));

			const __m128i pair01 = _mm_shuffle_epi32(lo_sum, _MM_SHUFFLE(2, 0, 2, 0));
			const __m128i pair23 = _mm_shuffle_epi32(hi_sum, _MM_SHUFFLE(2, 0, 2, 0));

			const __m128i p32p = _mm_unpacklo_epi64(pair01, pair23);

			const __m128i p32 = _mm_slli_epi32(p32p, 4);

			const __m128i keyed = _mm_add_epi32(p32, _mm_set_epi32(11, 10, 9, 8));

			vmin = _mm_min_epi32(vmin, keyed);
			vmax = _mm_max_epi32(vmax, keyed);
		}

		{
			const __m128i px = _mm_loadu_si128((const __m128i*) & pPixels[12]);
			const __m128i lo16 = _mm_unpacklo_epi8(px, ZERO);  // [r0 g0 b0 a0 r1 g1 b1 a1]
			const __m128i hi16 = _mm_unpackhi_epi8(px, ZERO);  // [r2 g2 b2 a2 r3 g3 b3 a3]

			const __m128i lo32p = _mm_madd_epi16(lo16, COEF);
			const __m128i hi32p = _mm_madd_epi16(hi16, COEF);

			const __m128i lo_sum = _mm_add_epi32(lo32p, _mm_shuffle_epi32(lo32p, _MM_SHUFFLE(2, 3, 0, 1)));
			const __m128i hi_sum = _mm_add_epi32(hi32p, _mm_shuffle_epi32(hi32p, _MM_SHUFFLE(2, 3, 0, 1)));

			const __m128i pair01 = _mm_shuffle_epi32(lo_sum, _MM_SHUFFLE(2, 0, 2, 0));
			const __m128i pair23 = _mm_shuffle_epi32(hi_sum, _MM_SHUFFLE(2, 0, 2, 0));

			const __m128i p32p = _mm_unpacklo_epi64(pair01, pair23);

			const __m128i p32 = _mm_slli_epi32(p32p, 4);

			const __m128i keyed = _mm_add_epi32(p32, _mm_set_epi32(15, 14, 13, 12));

			vmin = _mm_min_epi32(vmin, keyed);
			vmax = _mm_max_epi32(vmax, keyed);
		}

		__m128i t = _mm_shuffle_epi32(vmin, _MM_SHUFFLE(2, 3, 0, 1));
		vmin = _mm_min_epi32(vmin, t);
		t = _mm_shuffle_epi32(vmin, _MM_SHUFFLE(1, 0, 3, 2));
		vmin = _mm_min_epi32(vmin, t);
		const int min_keyed = _mm_cvtsi128_si32(vmin);

		t = _mm_shuffle_epi32(vmax, _MM_SHUFFLE(2, 3, 0, 1));
		vmax = _mm_max_epi32(vmax, t);
		t = _mm_shuffle_epi32(vmax, _MM_SHUFFLE(1, 0, 3, 2));
		vmax = _mm_max_epi32(vmax, t);
		const int max_keyed = _mm_cvtsi128_si32(vmax);

		*out_min_idx = (min_keyed & 0xF);
		*out_max_idx = (max_keyed & 0xF);
	}

	void eval_weights_mode6_rgb_sse41(
		const color_rgba* __restrict pPixels, uint8_t* __restrict pWeights,
		int lr, int lg, int lb,
		int hr, int hg, int hb,
		uint32_t p0, uint32_t p1)
	{
		lr = from_7(lr, p0); lg = from_7(lg, p0); lb = from_7(lb, p0);
		hr = from_7(hr, p1); hg = from_7(hg, p1); hb = from_7(hb, p1);

		const int dr = hr - lr;
		const int dg = hg - lg;
		const int db = hb - lb;

		const float denom = (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db)) + 0.00000125f;
		const float f = 15.0f / denom;

		const __m128i ZEROi = _mm_setzero_si128();
		const __m128i FIFTEEN = _mm_set1_epi32(15);
		const __m128  F = _mm_set1_ps(f);
		const __m128  HALF = _mm_set1_ps(0.5f);

		const __m128i EP16 = _mm_setr_epi16((short)lr, (short)lg, (short)lb, 0,
			(short)lr, (short)lg, (short)lb, 0);
		
		const __m128i COEF = _mm_setr_epi16((short)dr, (short)dg, (short)db, 0,
			(short)dr, (short)dg, (short)db, 0);

		for (int i = 0; i < 16; i += 4)
		{
			const __m128i px = _mm_loadu_si128((const __m128i*) & pPixels[i]);
						
			const __m128i lo16 = _mm_unpacklo_epi8(px, ZEROi);
			const __m128i hi16 = _mm_unpackhi_epi8(px, ZEROi);
						
			const __m128i lo_adj = _mm_sub_epi16(lo16, EP16);
			const __m128i hi_adj = _mm_sub_epi16(hi16, EP16);
						
			const __m128i lo32p = _mm_madd_epi16(lo_adj, COEF);
			const __m128i hi32p = _mm_madd_epi16(hi_adj, COEF);
						
			const __m128i lo_sum = _mm_add_epi32(lo32p, _mm_shuffle_epi32(lo32p, _MM_SHUFFLE(2, 3, 0, 1)));
			const __m128i hi_sum = _mm_add_epi32(hi32p, _mm_shuffle_epi32(hi32p, _MM_SHUFFLE(2, 3, 0, 1)));
			
			const __m128i pair01 = _mm_shuffle_epi32(lo_sum, _MM_SHUFFLE(2, 0, 2, 0));
			const __m128i pair23 = _mm_shuffle_epi32(hi_sum, _MM_SHUFFLE(2, 0, 2, 0));
			const __m128i dot32 = _mm_unpacklo_epi64(pair01, pair23);          
						
			__m128  y = _mm_add_ps(_mm_mul_ps(_mm_cvtepi32_ps(dot32), F), HALF);
			__m128i sel32 = _mm_cvttps_epi32(y);                                 
						
			sel32 = _mm_min_epi32(_mm_max_epi32(sel32, ZEROi), FIFTEEN);
						
			__m128i sel16 = _mm_packs_epi32(sel32, ZEROi);                     
			__m128i sel8 = _mm_packus_epi16(sel16, ZEROi);                     
			*(uint32_t*)&pWeights[i] = (uint32_t)_mm_cvtsi128_si32(sel8);
		}
	}
#endif

	BASISU_FORCE_INLINE uint32_t bc7_sse(
		int pr,
		int lr,
		int dr,
		int w)
	{
		assert((w >= 0) && (w <= 64));
		int re = pr - (lr + ((dr * (int)w + 32) >> 6));
		return (re * re);
	}

	BASISU_FORCE_INLINE uint32_t bc7_sse(
		int pr, int pg, int pb,
		int lr, int lg, int lb,
		int dr, int dg, int db,
		int w)
	{
		assert((w >= 0) && (w <= 64));
		int re = pr - (lr + ((dr * (int)w + 32) >> 6));
		int ge = pg - (lg + ((dg * (int)w + 32) >> 6));
		int be = pb - (lb + ((db * (int)w + 32) >> 6));
		return (re * re) + (ge * ge) + (be * be);
	}

	BASISU_FORCE_INLINE uint32_t bc7_sse(
		int pr, int pg, int pb, int pa,
		int lr, int lg, int lb, int la,
		int dr, int dg, int db, int da,
		int w)
	{
		assert((w >= 0) && (w <= 64));
		int re = pr - (lr + ((dr * (int)w + 32) >> 6));
		int ge = pg - (lg + ((dg * (int)w + 32) >> 6));
		int be = pb - (lb + ((db * (int)w + 32) >> 6));
		int ae = pa - (la + ((da * (int)w + 32) >> 6));
		return (re * re) + (ge * ge) + (be * be) + (ae * ae);
	}

	void eval_weights_mode6_rgb(const color_rgba* pPixels, uint8_t* pWeights, // 4-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb,
		uint32_t p0, uint32_t p1)
	{
		lr = from_7(lr, p0); lg = from_7(lg, p0); lb = from_7(lb, p0);
		hr = from_7(hr, p1); hg = from_7(hg, p1); hb = from_7(hb, p1);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 15.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = -(lr * dr + lg * dg + lb * db);

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)(float(pPixels[i + 0][0] * dr + pPixels[i + 0][1] * dg + pPixels[i + 0][2] * db + sofs) * f + .5f);
			int sel1 = (int)(float(pPixels[i + 1][0] * dr + pPixels[i + 1][1] * dg + pPixels[i + 1][2] * db + sofs) * f + .5f);
			int sel2 = (int)(float(pPixels[i + 2][0] * dr + pPixels[i + 2][1] * dg + pPixels[i + 2][2] * db + sofs) * f + .5f);
			int sel3 = (int)(float(pPixels[i + 3][0] * dr + pPixels[i + 3][1] * dg + pPixels[i + 3][2] * db + sofs) * f + .5f);

			if ((uint32_t)sel0 > 15) sel0 = (~sel0 >> 31) & 15;
			if ((uint32_t)sel1 > 15) sel1 = (~sel1 >> 31) & 15;
			if ((uint32_t)sel2 > 15) sel2 = (~sel2 >> 31) & 15;
			if ((uint32_t)sel3 > 15) sel3 = (~sel3 >> 31) & 15;

			pWeights[i + 0] = (uint8_t)sel0;
			pWeights[i + 1] = (uint8_t)sel1;
			pWeights[i + 2] = (uint8_t)sel2;
			pWeights[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode6_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights, // 4-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb,
		uint32_t p0, uint32_t p1)
	{
		lr = from_7(lr, p0); lg = from_7(lg, p0); lb = from_7(lb, p0);
		hr = from_7(hr, p1); hg = from_7(hg, p1); hb = from_7(hb, p1);

		// assumes packed a's are always 127
		const int la = from_7(127, p0);
		const int ha = from_7(127, p1);
		const int da = ha - la;

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 15.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = -(lr * dr + lg * dg + lb * db);

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)(float(pPixels[i + 0][0] * dr + pPixels[i + 0][1] * dg + pPixels[i + 0][2] * db + sofs) * f + .5f);
			int sel1 = (int)(float(pPixels[i + 1][0] * dr + pPixels[i + 1][1] * dg + pPixels[i + 1][2] * db + sofs) * f + .5f);
			int sel2 = (int)(float(pPixels[i + 2][0] * dr + pPixels[i + 2][1] * dg + pPixels[i + 2][2] * db + sofs) * f + .5f);
			int sel3 = (int)(float(pPixels[i + 3][0] * dr + pPixels[i + 3][1] * dg + pPixels[i + 3][2] * db + sofs) * f + .5f);

			if ((uint32_t)sel0 > 15) sel0 = (~sel0 >> 31) & 15;
			if ((uint32_t)sel1 > 15) sel1 = (~sel1 >> 31) & 15;
			if ((uint32_t)sel2 > 15) sel2 = (~sel2 >> 31) & 15;
			if ((uint32_t)sel3 > 15) sel3 = (~sel3 >> 31) & 15;

			pWeights[i + 0] = (uint8_t)sel0;
			pWeights[i + 1] = (uint8_t)sel1;
			pWeights[i + 2] = (uint8_t)sel2;
			pWeights[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][0], pPixels[i + 0][1], pPixels[i + 0][2], pPixels[i + 0][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel0]);
			sse += bc7_sse(pPixels[i + 1][0], pPixels[i + 1][1], pPixels[i + 1][2], pPixels[i + 1][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel1]);
			sse += bc7_sse(pPixels[i + 2][0], pPixels[i + 2][1], pPixels[i + 2][2], pPixels[i + 2][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel2]);
			sse += bc7_sse(pPixels[i + 3][0], pPixels[i + 3][1], pPixels[i + 3][2], pPixels[i + 3][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel3]);
		}

		return sse;
	}

	void eval_weights_mode6_rgba(const color_rgba* pPixels, uint8_t* pWeights, // 4-bits
		int lr, int lg, int lb, int la, int p0,
		int hr, int hg, int hb, int ha, int p1)
	{
		lr = from_7(lr, p0); lg = from_7(lg, p0); lb = from_7(lb, p0); la = from_7(la, p0);
		hr = from_7(hr, p1); hg = from_7(hg, p1); hb = from_7(hb, p1); ha = from_7(ha, p1);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;
		int da = ha - la;

		const float f = 15.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + basisu::squarei(da) + .00000125f);

		const int sofs = -(lr * dr + lg * dg + lb * db + la * da);

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)(float(pPixels[i + 0][0] * dr + pPixels[i + 0][1] * dg + pPixels[i + 0][2] * db + pPixels[i + 0][3] * da + sofs) * f + .5f);
			int sel1 = (int)(float(pPixels[i + 1][0] * dr + pPixels[i + 1][1] * dg + pPixels[i + 1][2] * db + pPixels[i + 1][3] * da + sofs) * f + .5f);
			int sel2 = (int)(float(pPixels[i + 2][0] * dr + pPixels[i + 2][1] * dg + pPixels[i + 2][2] * db + pPixels[i + 2][3] * da + sofs) * f + .5f);
			int sel3 = (int)(float(pPixels[i + 3][0] * dr + pPixels[i + 3][1] * dg + pPixels[i + 3][2] * db + pPixels[i + 3][3] * da + sofs) * f + .5f);

			if ((uint32_t)sel0 > 15) sel0 = (~sel0 >> 31) & 15;
			if ((uint32_t)sel1 > 15) sel1 = (~sel1 >> 31) & 15;
			if ((uint32_t)sel2 > 15) sel2 = (~sel2 >> 31) & 15;
			if ((uint32_t)sel3 > 15) sel3 = (~sel3 >> 31) & 15;

			pWeights[i + 0] = (uint8_t)sel0;
			pWeights[i + 1] = (uint8_t)sel1;
			pWeights[i + 2] = (uint8_t)sel2;
			pWeights[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode6_rgba_sse(const color_rgba* pPixels, uint8_t* pWeights, // 4-bits
		int lr, int lg, int lb, int la, int p0,
		int hr, int hg, int hb, int ha, int p1)
	{
		lr = from_7(lr, p0); lg = from_7(lg, p0); lb = from_7(lb, p0); la = from_7(la, p0);
		hr = from_7(hr, p1); hg = from_7(hg, p1); hb = from_7(hb, p1); ha = from_7(ha, p1);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;
		int da = ha - la;

		const float f = 15.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + basisu::squarei(da) + .00000125f);

		const int sofs = -(lr * dr + lg * dg + lb * db + la * da);

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)(float(pPixels[i + 0][0] * dr + pPixels[i + 0][1] * dg + pPixels[i + 0][2] * db + pPixels[i + 0][3] * da + sofs) * f + .5f);
			int sel1 = (int)(float(pPixels[i + 1][0] * dr + pPixels[i + 1][1] * dg + pPixels[i + 1][2] * db + pPixels[i + 1][3] * da + sofs) * f + .5f);
			int sel2 = (int)(float(pPixels[i + 2][0] * dr + pPixels[i + 2][1] * dg + pPixels[i + 2][2] * db + pPixels[i + 2][3] * da + sofs) * f + .5f);
			int sel3 = (int)(float(pPixels[i + 3][0] * dr + pPixels[i + 3][1] * dg + pPixels[i + 3][2] * db + pPixels[i + 3][3] * da + sofs) * f + .5f);

			if ((uint32_t)sel0 > 15) sel0 = (~sel0 >> 31) & 15;
			if ((uint32_t)sel1 > 15) sel1 = (~sel1 >> 31) & 15;
			if ((uint32_t)sel2 > 15) sel2 = (~sel2 >> 31) & 15;
			if ((uint32_t)sel3 > 15) sel3 = (~sel3 >> 31) & 15;

			pWeights[i + 0] = (uint8_t)sel0;
			pWeights[i + 1] = (uint8_t)sel1;
			pWeights[i + 2] = (uint8_t)sel2;
			pWeights[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][0], pPixels[i + 0][1], pPixels[i + 0][2], pPixels[i + 0][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel0]);
			sse += bc7_sse(pPixels[i + 1][0], pPixels[i + 1][1], pPixels[i + 1][2], pPixels[i + 1][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel1]);
			sse += bc7_sse(pPixels[i + 2][0], pPixels[i + 2][1], pPixels[i + 2][2], pPixels[i + 2][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel2]);
			sse += bc7_sse(pPixels[i + 3][0], pPixels[i + 3][1], pPixels[i + 3][2], pPixels[i + 3][3], lr, lg, lb, la, dr, dg, db, da, basist::g_bc7_weights4[sel3]);
		}

		return sse;
	}

	void eval_weights_mode1_rgb(const color_rgba* pPixels, uint8_t* pWeights, // 3-bits
		uint32_t blr[2], uint32_t blg[2], uint32_t blb[2], uint32_t bhr[2], uint32_t bhg[2], uint32_t bhb[2],
		uint32_t pbits[2], uint32_t subset_bitmask)
	{
		int lr[2], lg[2], lb[2], hr[2], hg[2], hb[2], dr[2], dg[2], db[2];

		for (uint32_t s = 0; s < 2; s++)
		{
			lr[s] = from_6(blr[s], pbits[s]);
			lg[s] = from_6(blg[s], pbits[s]);
			lb[s] = from_6(blb[s], pbits[s]);

			hr[s] = from_6(bhr[s], pbits[s]);
			hg[s] = from_6(bhg[s], pbits[s]);
			hb[s] = from_6(bhb[s], pbits[s]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[2] =
		{
			7.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			7.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f)
		};

		const int sofs[2] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1] };

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = (subset_bitmask >> i) & 1;

			int sel = (int)((float)(
				((int)pPixels[i][0]) * dr[subset_index] + ((int)pPixels[i][1]) * dg[subset_index] + ((int)pPixels[i][2]) * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 7)
				sel = (~sel >> 31) & 7;

			pWeights[i] = (uint8_t)sel;
		}
	}

	uint32_t eval_weights_mode1_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights, // 3-bits
		uint32_t blr[2], uint32_t blg[2], uint32_t blb[2], uint32_t bhr[2], uint32_t bhg[2], uint32_t bhb[2],
		uint32_t pbits[2], uint32_t subset_bitmask)
	{
		int lr[2], lg[2], lb[2], hr[2], hg[2], hb[2], dr[2], dg[2], db[2];

		for (uint32_t s = 0; s < 2; s++)
		{
			lr[s] = from_6(blr[s], pbits[s]);
			lg[s] = from_6(blg[s], pbits[s]);
			lb[s] = from_6(blb[s], pbits[s]);

			hr[s] = from_6(bhr[s], pbits[s]);
			hg[s] = from_6(bhg[s], pbits[s]);
			hb[s] = from_6(bhb[s], pbits[s]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[2] =
		{
			7.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			7.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f)
		};

		const int sofs[2] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1] };

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = (subset_bitmask >> i) & 1;

			int sel = (int)((float)(
				((int)pPixels[i][0]) * dr[subset_index] + ((int)pPixels[i][1]) * dg[subset_index] + ((int)pPixels[i][2]) * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 7)
				sel = (~sel >> 31) & 7;

			pWeights[i] = (uint8_t)sel;

			sse += bc7_sse(pPixels[i][0], pPixels[i][1], pPixels[i][2], lr[subset_index], lg[subset_index], lb[subset_index], dr[subset_index], dg[subset_index], db[subset_index], basist::g_bc7_weights3[sel]);
		}

		return sse;
	}

	void eval_weights_mode7_rgba(const color_rgba* pPixels, uint8_t* pWeights, // 2-bits
		uint32_t blr[2], uint32_t blg[2], uint32_t blb[2], uint32_t bla[2],
		uint32_t bhr[2], uint32_t bhg[2], uint32_t bhb[2], uint32_t bha[2],
		uint32_t pbits[4], uint32_t subset_bitmask)
	{
		int lr[2], lg[2], lb[2], la[2];
		int hr[2], hg[2], hb[2], ha[2];
		int dr[2], dg[2], db[2], da[2];

		for (uint32_t s = 0; s < 2; s++)
		{
			const uint32_t l_pbit = pbits[s * 2 + 0], h_pbit = pbits[s * 2 + 1];

			lr[s] = from_5(blr[s], l_pbit);
			lg[s] = from_5(blg[s], l_pbit);
			lb[s] = from_5(blb[s], l_pbit);
			la[s] = from_5(bla[s], l_pbit);

			hr[s] = from_5(bhr[s], h_pbit);
			hg[s] = from_5(bhg[s], h_pbit);
			hb[s] = from_5(bhb[s], h_pbit);
			ha[s] = from_5(bha[s], h_pbit);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
			da[s] = ha[s] - la[s];
		}

		const float f[2] =
		{
			3.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + basisu::squarei(da[0]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + basisu::squarei(da[1]) + .00000125f)
		};

		const int sofs[2] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0] + la[0] * da[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1] + la[1] * da[1] };

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = (subset_bitmask >> i) & 1;

			int sel = (int)((float)(
				((int)pPixels[i][0]) * dr[subset_index] + ((int)pPixels[i][1]) * dg[subset_index] + ((int)pPixels[i][2]) * db[subset_index] + ((int)pPixels[i][3]) * da[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 3)
				sel = (~sel >> 31) & 3;

			pWeights[i] = (uint8_t)sel;
		}
	}

	uint32_t eval_weights_mode7_rgba_sse(const color_rgba* pPixels, uint8_t* pWeights, // 2-bits
		uint32_t blr[2], uint32_t blg[2], uint32_t blb[2], uint32_t bla[2],
		uint32_t bhr[2], uint32_t bhg[2], uint32_t bhb[2], uint32_t bha[2],
		uint32_t pbits[4], uint32_t subset_bitmask)
	{
		int lr[2], lg[2], lb[2], la[2];
		int hr[2], hg[2], hb[2], ha[2];
		int dr[2], dg[2], db[2], da[2];

		for (uint32_t s = 0; s < 2; s++)
		{
			const uint32_t l_pbit = pbits[s * 2 + 0], h_pbit = pbits[s * 2 + 1];

			lr[s] = from_5(blr[s], l_pbit);
			lg[s] = from_5(blg[s], l_pbit);
			lb[s] = from_5(blb[s], l_pbit);
			la[s] = from_5(bla[s], l_pbit);

			hr[s] = from_5(bhr[s], h_pbit);
			hg[s] = from_5(bhg[s], h_pbit);
			hb[s] = from_5(bhb[s], h_pbit);
			ha[s] = from_5(bha[s], h_pbit);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
			da[s] = ha[s] - la[s];
		}

		const float f[2] =
		{
			3.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + basisu::squarei(da[0]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + basisu::squarei(da[1]) + .00000125f)
		};

		const int sofs[2] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0] + la[0] * da[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1] + la[1] * da[1] };

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = (subset_bitmask >> i) & 1;

			int sel = (int)((float)(
				((int)pPixels[i][0]) * dr[subset_index] + ((int)pPixels[i][1]) * dg[subset_index] + ((int)pPixels[i][2]) * db[subset_index] + ((int)pPixels[i][3]) * da[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 3)
				sel = (~sel >> 31) & 3;

			pWeights[i] = (uint8_t)sel;

			sse += bc7_sse(pPixels[i][0], pPixels[i][1], pPixels[i][2], pPixels[i][3],
				lr[subset_index], lg[subset_index], lb[subset_index], la[subset_index],
				dr[subset_index], dg[subset_index], db[subset_index], da[subset_index], basist::g_bc7_weights2[sel]);
		}

		return sse;
	}

	void eval_weights_mode3_rgb(const color_rgba* pPixels, uint8_t* pWeights, // 2-bits
		uint32_t blr[2], uint32_t blg[2], uint32_t blb[2], uint32_t bhr[2], uint32_t bhg[2], uint32_t bhb[2],
		uint32_t pbits[4], uint32_t subset_bitmask)
	{
		int lr[2], lg[2], lb[2], hr[2], hg[2], hb[2], dr[2], dg[2], db[2];

		for (uint32_t s = 0; s < 2; s++)
		{
			lr[s] = from_7(blr[s], pbits[s * 2 + 0]);
			lg[s] = from_7(blg[s], pbits[s * 2 + 0]);
			lb[s] = from_7(blb[s], pbits[s * 2 + 0]);

			hr[s] = from_7(bhr[s], pbits[s * 2 + 1]);
			hg[s] = from_7(bhg[s], pbits[s * 2 + 1]);
			hb[s] = from_7(bhb[s], pbits[s * 2 + 1]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[2] =
		{
			3.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f)
		};

		const int sofs[2] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1] };

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = (subset_bitmask >> i) & 1;

			int sel = (int)((float)(
				((int)pPixels[i][0]) * dr[subset_index] + ((int)pPixels[i][1]) * dg[subset_index] + ((int)pPixels[i][2]) * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 3)
				sel = (~sel >> 31) & 3;

			pWeights[i] = (uint8_t)sel;
		}
	}

	uint32_t eval_weights_mode3_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights, // 2-bits
		uint32_t blr[2], uint32_t blg[2], uint32_t blb[2], uint32_t bhr[2], uint32_t bhg[2], uint32_t bhb[2],
		uint32_t pbits[4], uint32_t subset_bitmask)
	{
		int lr[2], lg[2], lb[2], hr[2], hg[2], hb[2], dr[2], dg[2], db[2];

		for (uint32_t s = 0; s < 2; s++)
		{
			lr[s] = from_7(blr[s], pbits[s * 2 + 0]);
			lg[s] = from_7(blg[s], pbits[s * 2 + 0]);
			lb[s] = from_7(blb[s], pbits[s * 2 + 0]);

			hr[s] = from_7(bhr[s], pbits[s * 2 + 1]);
			hg[s] = from_7(bhg[s], pbits[s * 2 + 1]);
			hb[s] = from_7(bhb[s], pbits[s * 2 + 1]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[2] =
		{
			3.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f)
		};

		const int sofs[2] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1] };

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = (subset_bitmask >> i) & 1;

			int sel = (int)((float)(
				((int)pPixels[i][0]) * dr[subset_index] + ((int)pPixels[i][1]) * dg[subset_index] + ((int)pPixels[i][2]) * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 3)
				sel = (~sel >> 31) & 3;

			pWeights[i] = (uint8_t)sel;

			sse += bc7_sse(pPixels[i][0], pPixels[i][1], pPixels[i][2], lr[subset_index], lg[subset_index], lb[subset_index], dr[subset_index], dg[subset_index], db[subset_index], basist::g_bc7_weights2[sel]);
		}

		return sse;
	}

	void eval_weights_mode0_rgb(const color_rgba* pPixels, uint8_t* pWeights, // 3-bits
		uint32_t blr[3], uint32_t blg[3], uint32_t blb[3],
		uint32_t bhr[3], uint32_t bhg[3], uint32_t bhb[3],
		uint32_t pbits[6],
		uint32_t pat_index)
	{
		assert(pat_index <= 15);
		int lr[3], lg[3], lb[3], hr[3], hg[3], hb[3], dr[3], dg[3], db[3];

		for (uint32_t s = 0; s < 3; s++)
		{
			lr[s] = from_4(blr[s], pbits[s * 2 + 0]);
			lg[s] = from_4(blg[s], pbits[s * 2 + 0]);
			lb[s] = from_4(blb[s], pbits[s * 2 + 0]);

			hr[s] = from_4(bhr[s], pbits[s * 2 + 1]);
			hg[s] = from_4(bhg[s], pbits[s * 2 + 1]);
			hb[s] = from_4(bhb[s], pbits[s * 2 + 1]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[3] =
		{
			7.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			7.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f),
			7.0f / (float)(basisu::squarei(dr[2]) + basisu::squarei(dg[2]) + basisu::squarei(db[2]) + .00000125f)
		};

		const int sofs[3] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1],
			lr[2] * dr[2] + lg[2] * dg[2] + lb[2] * db[2] };

		const uint8_t* pPart_map = &g_bc7_partition3[pat_index * 16];

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];

			int sel = (int)((float)(
				(int)pPixels[i][0] * dr[subset_index] + (int)pPixels[i][1] * dg[subset_index] + (int)pPixels[i][2] * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 7)
				sel = (~sel >> 31) & 7;

			pWeights[i] = (uint8_t)sel;
		}
	}

	uint32_t eval_weights_mode0_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights, // 3-bits
		uint32_t blr[3], uint32_t blg[3], uint32_t blb[3],
		uint32_t bhr[3], uint32_t bhg[3], uint32_t bhb[3],
		uint32_t pbits[6],
		uint32_t pat_index)
	{
		assert(pat_index <= 15);
		int lr[3], lg[3], lb[3], hr[3], hg[3], hb[3], dr[3], dg[3], db[3];

		for (uint32_t s = 0; s < 3; s++)
		{
			lr[s] = from_4(blr[s], pbits[s * 2 + 0]);
			lg[s] = from_4(blg[s], pbits[s * 2 + 0]);
			lb[s] = from_4(blb[s], pbits[s * 2 + 0]);

			hr[s] = from_4(bhr[s], pbits[s * 2 + 1]);
			hg[s] = from_4(bhg[s], pbits[s * 2 + 1]);
			hb[s] = from_4(bhb[s], pbits[s * 2 + 1]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[3] =
		{
			7.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			7.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f),
			7.0f / (float)(basisu::squarei(dr[2]) + basisu::squarei(dg[2]) + basisu::squarei(db[2]) + .00000125f)
		};

		const int sofs[3] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1],
			lr[2] * dr[2] + lg[2] * dg[2] + lb[2] * db[2] };

		const uint8_t* pPart_map = &g_bc7_partition3[pat_index * 16];

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];

			int sel = (int)((float)(
				(int)pPixels[i][0] * dr[subset_index] + (int)pPixels[i][1] * dg[subset_index] + (int)pPixels[i][2] * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 7)
				sel = (~sel >> 31) & 7;

			pWeights[i] = (uint8_t)sel;

			sse += bc7_sse(pPixels[i][0], pPixels[i][1], pPixels[i][2],
				lr[subset_index], lg[subset_index], lb[subset_index],
				dr[subset_index], dg[subset_index], db[subset_index], basist::g_bc7_weights3[sel]);
		}

		return sse;
	}

	void eval_weights_mode2_rgb(const color_rgba* pPixels, uint8_t* pWeights, // 2-bits
		uint32_t blr[3], uint32_t blg[3], uint32_t blb[3], uint32_t bhr[3], uint32_t bhg[3], uint32_t bhb[3],
		uint32_t pat_index)
	{
		int lr[3], lg[3], lb[3], hr[3], hg[3], hb[3], dr[3], dg[3], db[3];

		for (uint32_t s = 0; s < 3; s++)
		{
			lr[s] = from_5(blr[s]);
			lg[s] = from_5(blg[s]);
			lb[s] = from_5(blb[s]);

			hr[s] = from_5(bhr[s]);
			hg[s] = from_5(bhg[s]);
			hb[s] = from_5(bhb[s]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[3] =
		{
			3.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[2]) + basisu::squarei(dg[2]) + basisu::squarei(db[2]) + .00000125f)
		};

		const int sofs[3] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1],
			lr[2] * dr[2] + lg[2] * dg[2] + lb[2] * db[2] };

		const uint8_t* pPart_map = &g_bc7_partition3[pat_index * 16];

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];

			int sel = (int)((float)(
				(int)pPixels[i][0] * dr[subset_index] + (int)pPixels[i][1] * dg[subset_index] + (int)pPixels[i][2] * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 3)
				sel = (~sel >> 31) & 3;

			pWeights[i] = (uint8_t)sel;
		}
	}

	uint32_t eval_weights_mode2_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights, // 2-bits
		uint32_t blr[3], uint32_t blg[3], uint32_t blb[3], uint32_t bhr[3], uint32_t bhg[3], uint32_t bhb[3],
		uint32_t pat_index)
	{
		int lr[3], lg[3], lb[3], hr[3], hg[3], hb[3], dr[3], dg[3], db[3];

		for (uint32_t s = 0; s < 3; s++)
		{
			lr[s] = from_5(blr[s]);
			lg[s] = from_5(blg[s]);
			lb[s] = from_5(blb[s]);

			hr[s] = from_5(bhr[s]);
			hg[s] = from_5(bhg[s]);
			hb[s] = from_5(bhb[s]);

			dr[s] = hr[s] - lr[s];
			dg[s] = hg[s] - lg[s];
			db[s] = hb[s] - lb[s];
		}

		const float f[3] =
		{
			3.0f / (float)(basisu::squarei(dr[0]) + basisu::squarei(dg[0]) + basisu::squarei(db[0]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[1]) + basisu::squarei(dg[1]) + basisu::squarei(db[1]) + .00000125f),
			3.0f / (float)(basisu::squarei(dr[2]) + basisu::squarei(dg[2]) + basisu::squarei(db[2]) + .00000125f)
		};

		const int sofs[3] = {
			lr[0] * dr[0] + lg[0] * dg[0] + lb[0] * db[0],
			lr[1] * dr[1] + lg[1] * dg[1] + lb[1] * db[1],
			lr[2] * dr[2] + lg[2] * dg[2] + lb[2] * db[2] };

		const uint8_t* pPart_map = &g_bc7_partition3[pat_index * 16];

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = pPart_map[i];

			int sel = (int)((float)(
				(int)pPixels[i][0] * dr[subset_index] + (int)pPixels[i][1] * dg[subset_index] + (int)pPixels[i][2] * db[subset_index] - sofs[subset_index]) * f[subset_index] + .5f);

			if ((uint32_t)sel > 3)
				sel = (~sel >> 31) & 3;

			pWeights[i] = (uint8_t)sel;

			sse += bc7_sse(pPixels[i][0], pPixels[i][1], pPixels[i][2],
				lr[subset_index], lg[subset_index], lb[subset_index],
				dr[subset_index], dg[subset_index], db[subset_index], basist::g_bc7_weights2[sel]);
		}

		return sse;
	}

	void eval_weights_mode4_3bit_rgb(const color_rgba* pPixels, uint8_t* pWeights0, // 3-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb)
	{
		lr = from_5(lr); lg = from_5(lg); lb = from_5(lb);
		hr = from_5(hr); hg = from_5(hg); hb = from_5(hb);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 7.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = lr * dr + lg * dg + lb * db;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)((int)pPixels[i + 0][0] * dr + (int)pPixels[i + 0][1] * dg + (int)pPixels[i + 0][2] * db - sofs) * f + .5f);
			int sel1 = (int)((float)((int)pPixels[i + 1][0] * dr + (int)pPixels[i + 1][1] * dg + (int)pPixels[i + 1][2] * db - sofs) * f + .5f);
			int sel2 = (int)((float)((int)pPixels[i + 2][0] * dr + (int)pPixels[i + 2][1] * dg + (int)pPixels[i + 2][2] * db - sofs) * f + .5f);
			int sel3 = (int)((float)((int)pPixels[i + 3][0] * dr + (int)pPixels[i + 3][1] * dg + (int)pPixels[i + 3][2] * db - sofs) * f + .5f);

			if ((uint32_t)sel0 > 7) sel0 = (~sel0 >> 31) & 7;
			if ((uint32_t)sel1 > 7) sel1 = (~sel1 >> 31) & 7;
			if ((uint32_t)sel2 > 7) sel2 = (~sel2 >> 31) & 7;
			if ((uint32_t)sel3 > 7) sel3 = (~sel3 >> 31) & 7;

			pWeights0[i + 0] = (uint8_t)sel0;
			pWeights0[i + 1] = (uint8_t)sel1;
			pWeights0[i + 2] = (uint8_t)sel2;
			pWeights0[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode4_3bit_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights0, // 3-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb)
	{
		lr = from_5(lr); lg = from_5(lg); lb = from_5(lb);
		hr = from_5(hr); hg = from_5(hg); hb = from_5(hb);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 7.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = lr * dr + lg * dg + lb * db;

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)((int)pPixels[i + 0][0] * dr + (int)pPixels[i + 0][1] * dg + (int)pPixels[i + 0][2] * db - sofs) * f + .5f);
			int sel1 = (int)((float)((int)pPixels[i + 1][0] * dr + (int)pPixels[i + 1][1] * dg + (int)pPixels[i + 1][2] * db - sofs) * f + .5f);
			int sel2 = (int)((float)((int)pPixels[i + 2][0] * dr + (int)pPixels[i + 2][1] * dg + (int)pPixels[i + 2][2] * db - sofs) * f + .5f);
			int sel3 = (int)((float)((int)pPixels[i + 3][0] * dr + (int)pPixels[i + 3][1] * dg + (int)pPixels[i + 3][2] * db - sofs) * f + .5f);

			if ((uint32_t)sel0 > 7) sel0 = (~sel0 >> 31) & 7;
			if ((uint32_t)sel1 > 7) sel1 = (~sel1 >> 31) & 7;
			if ((uint32_t)sel2 > 7) sel2 = (~sel2 >> 31) & 7;
			if ((uint32_t)sel3 > 7) sel3 = (~sel3 >> 31) & 7;

			pWeights0[i + 0] = (uint8_t)sel0;
			pWeights0[i + 1] = (uint8_t)sel1;
			pWeights0[i + 2] = (uint8_t)sel2;
			pWeights0[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][0], pPixels[i + 0][1], pPixels[i + 0][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights3[sel0]);
			sse += bc7_sse(pPixels[i + 1][0], pPixels[i + 1][1], pPixels[i + 1][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights3[sel1]);
			sse += bc7_sse(pPixels[i + 2][0], pPixels[i + 2][1], pPixels[i + 2][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights3[sel2]);
			sse += bc7_sse(pPixels[i + 3][0], pPixels[i + 3][1], pPixels[i + 3][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights3[sel3]);
		}

		return sse;
	}

	void eval_weights_mode4_2bit_rgb(const color_rgba* pPixels, uint8_t* pWeights0, // 2-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb)
	{
		lr = from_5(lr); lg = from_5(lg); lb = from_5(lb);
		hr = from_5(hr); hg = from_5(hg); hb = from_5(hb);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 3.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = lr * dr + lg * dg + lb * db;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)((int)pPixels[i + 0][0] * dr + (int)pPixels[i + 0][1] * dg + (int)pPixels[i + 0][2] * db - sofs) * f + .5f);
			int sel1 = (int)((float)((int)pPixels[i + 1][0] * dr + (int)pPixels[i + 1][1] * dg + (int)pPixels[i + 1][2] * db - sofs) * f + .5f);
			int sel2 = (int)((float)((int)pPixels[i + 2][0] * dr + (int)pPixels[i + 2][1] * dg + (int)pPixels[i + 2][2] * db - sofs) * f + .5f);
			int sel3 = (int)((float)((int)pPixels[i + 3][0] * dr + (int)pPixels[i + 3][1] * dg + (int)pPixels[i + 3][2] * db - sofs) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights0[i + 0] = (uint8_t)sel0;
			pWeights0[i + 1] = (uint8_t)sel1;
			pWeights0[i + 2] = (uint8_t)sel2;
			pWeights0[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode4_2bit_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights0, // 2-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb)
	{
		lr = from_5(lr); lg = from_5(lg); lb = from_5(lb);
		hr = from_5(hr); hg = from_5(hg); hb = from_5(hb);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 3.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = lr * dr + lg * dg + lb * db;

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)((int)pPixels[i + 0][0] * dr + (int)pPixels[i + 0][1] * dg + (int)pPixels[i + 0][2] * db - sofs) * f + .5f);
			int sel1 = (int)((float)((int)pPixels[i + 1][0] * dr + (int)pPixels[i + 1][1] * dg + (int)pPixels[i + 1][2] * db - sofs) * f + .5f);
			int sel2 = (int)((float)((int)pPixels[i + 2][0] * dr + (int)pPixels[i + 2][1] * dg + (int)pPixels[i + 2][2] * db - sofs) * f + .5f);
			int sel3 = (int)((float)((int)pPixels[i + 3][0] * dr + (int)pPixels[i + 3][1] * dg + (int)pPixels[i + 3][2] * db - sofs) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights0[i + 0] = (uint8_t)sel0;
			pWeights0[i + 1] = (uint8_t)sel1;
			pWeights0[i + 2] = (uint8_t)sel2;
			pWeights0[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][0], pPixels[i + 0][1], pPixels[i + 0][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel0]);
			sse += bc7_sse(pPixels[i + 1][0], pPixels[i + 1][1], pPixels[i + 1][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel1]);
			sse += bc7_sse(pPixels[i + 2][0], pPixels[i + 2][1], pPixels[i + 2][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel2]);
			sse += bc7_sse(pPixels[i + 3][0], pPixels[i + 3][1], pPixels[i + 3][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel3]);
		}

		return sse;
	}

	void eval_weights_mode4_2bit_a(const color_rgba* pPixels, uint8_t* pWeights1, // 2-bits
		int la, int ha)
	{
		la = from_6(la);
		ha = from_6(ha);

		int da = ha - la;

		const float f = 3.0f / (float)(da + .00000125f);

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)(pPixels[i + 0][3] - la) * f + .5f);
			int sel1 = (int)((float)(pPixels[i + 1][3] - la) * f + .5f);
			int sel2 = (int)((float)(pPixels[i + 2][3] - la) * f + .5f);
			int sel3 = (int)((float)(pPixels[i + 3][3] - la) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights1[i + 0] = (uint8_t)sel0;
			pWeights1[i + 1] = (uint8_t)sel1;
			pWeights1[i + 2] = (uint8_t)sel2;
			pWeights1[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode4_2bit_a_sse(const color_rgba* pPixels, uint8_t* pWeights1, // 2-bits
		int la, int ha)
	{
		la = from_6(la);
		ha = from_6(ha);

		int da = ha - la;

		const float f = 3.0f / (float)(da + .00000125f);

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)(pPixels[i + 0][3] - la) * f + .5f);
			int sel1 = (int)((float)(pPixels[i + 1][3] - la) * f + .5f);
			int sel2 = (int)((float)(pPixels[i + 2][3] - la) * f + .5f);
			int sel3 = (int)((float)(pPixels[i + 3][3] - la) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights1[i + 0] = (uint8_t)sel0;
			pWeights1[i + 1] = (uint8_t)sel1;
			pWeights1[i + 2] = (uint8_t)sel2;
			pWeights1[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][3], la, da, basist::g_bc7_weights2[sel0]);
			sse += bc7_sse(pPixels[i + 1][3], la, da, basist::g_bc7_weights2[sel1]);
			sse += bc7_sse(pPixels[i + 2][3], la, da, basist::g_bc7_weights2[sel2]);
			sse += bc7_sse(pPixels[i + 3][3], la, da, basist::g_bc7_weights2[sel3]);
		}

		return sse;
	}

	void eval_weights_mode4_3bit_a(const color_rgba* pPixels, uint8_t* pWeights1, // 3-bits
		int la, int ha)
	{
		la = from_6(la);
		ha = from_6(ha);

		int da = ha - la;

		const float f = 7.0f / (float)(da + .00000125f);

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)(pPixels[i + 0][3] - la) * f + .5f);
			int sel1 = (int)((float)(pPixels[i + 1][3] - la) * f + .5f);
			int sel2 = (int)((float)(pPixels[i + 2][3] - la) * f + .5f);
			int sel3 = (int)((float)(pPixels[i + 3][3] - la) * f + .5f);

			if ((uint32_t)sel0 > 7) sel0 = (~sel0 >> 31) & 7;
			if ((uint32_t)sel1 > 7) sel1 = (~sel1 >> 31) & 7;
			if ((uint32_t)sel2 > 7) sel2 = (~sel2 >> 31) & 7;
			if ((uint32_t)sel3 > 7) sel3 = (~sel3 >> 31) & 7;

			pWeights1[i + 0] = (uint8_t)sel0;
			pWeights1[i + 1] = (uint8_t)sel1;
			pWeights1[i + 2] = (uint8_t)sel2;
			pWeights1[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode4_3bit_a_sse(const color_rgba* pPixels, uint8_t* pWeights1, // 3-bits
		int la, int ha)
	{
		la = from_6(la);
		ha = from_6(ha);

		int da = ha - la;

		const float f = 7.0f / (float)(da + .00000125f);

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)(pPixels[i + 0][3] - la) * f + .5f);
			int sel1 = (int)((float)(pPixels[i + 1][3] - la) * f + .5f);
			int sel2 = (int)((float)(pPixels[i + 2][3] - la) * f + .5f);
			int sel3 = (int)((float)(pPixels[i + 3][3] - la) * f + .5f);

			if ((uint32_t)sel0 > 7) sel0 = (~sel0 >> 31) & 7;
			if ((uint32_t)sel1 > 7) sel1 = (~sel1 >> 31) & 7;
			if ((uint32_t)sel2 > 7) sel2 = (~sel2 >> 31) & 7;
			if ((uint32_t)sel3 > 7) sel3 = (~sel3 >> 31) & 7;

			pWeights1[i + 0] = (uint8_t)sel0;
			pWeights1[i + 1] = (uint8_t)sel1;
			pWeights1[i + 2] = (uint8_t)sel2;
			pWeights1[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][3], la, da, basist::g_bc7_weights3[sel0]);
			sse += bc7_sse(pPixels[i + 1][3], la, da, basist::g_bc7_weights3[sel1]);
			sse += bc7_sse(pPixels[i + 2][3], la, da, basist::g_bc7_weights3[sel2]);
			sse += bc7_sse(pPixels[i + 3][3], la, da, basist::g_bc7_weights3[sel3]);
		}

		return sse;
	}

	void eval_weights_mode5_2bit_rgb(const color_rgba* pPixels, uint8_t* pWeights0, // 2-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb)
	{
		lr = from_7(lr); lg = from_7(lg); lb = from_7(lb);
		hr = from_7(hr); hg = from_7(hg); hb = from_7(hb);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 3.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = lr * dr + lg * dg + lb * db;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)((int)pPixels[i + 0][0] * dr + (int)pPixels[i + 0][1] * dg + (int)pPixels[i + 0][2] * db - sofs) * f + .5f);
			int sel1 = (int)((float)((int)pPixels[i + 1][0] * dr + (int)pPixels[i + 1][1] * dg + (int)pPixels[i + 1][2] * db - sofs) * f + .5f);
			int sel2 = (int)((float)((int)pPixels[i + 2][0] * dr + (int)pPixels[i + 2][1] * dg + (int)pPixels[i + 2][2] * db - sofs) * f + .5f);
			int sel3 = (int)((float)((int)pPixels[i + 3][0] * dr + (int)pPixels[i + 3][1] * dg + (int)pPixels[i + 3][2] * db - sofs) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights0[i + 0] = (uint8_t)sel0;
			pWeights0[i + 1] = (uint8_t)sel1;
			pWeights0[i + 2] = (uint8_t)sel2;
			pWeights0[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode5_2bit_rgb_sse(const color_rgba* pPixels, uint8_t* pWeights0, // 2-bits
		int lr, int lg, int lb,
		int hr, int hg, int hb)
	{
		lr = from_7(lr); lg = from_7(lg); lb = from_7(lb);
		hr = from_7(hr); hg = from_7(hg); hb = from_7(hb);

		int dr = hr - lr;
		int dg = hg - lg;
		int db = hb - lb;

		const float f = 3.0f / (float)(basisu::squarei(dr) + basisu::squarei(dg) + basisu::squarei(db) + .00000125f);

		const int sofs = lr * dr + lg * dg + lb * db;

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)((int)pPixels[i + 0][0] * dr + (int)pPixels[i + 0][1] * dg + (int)pPixels[i + 0][2] * db - sofs) * f + .5f);
			int sel1 = (int)((float)((int)pPixels[i + 1][0] * dr + (int)pPixels[i + 1][1] * dg + (int)pPixels[i + 1][2] * db - sofs) * f + .5f);
			int sel2 = (int)((float)((int)pPixels[i + 2][0] * dr + (int)pPixels[i + 2][1] * dg + (int)pPixels[i + 2][2] * db - sofs) * f + .5f);
			int sel3 = (int)((float)((int)pPixels[i + 3][0] * dr + (int)pPixels[i + 3][1] * dg + (int)pPixels[i + 3][2] * db - sofs) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights0[i + 0] = (uint8_t)sel0;
			pWeights0[i + 1] = (uint8_t)sel1;
			pWeights0[i + 2] = (uint8_t)sel2;
			pWeights0[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][0], pPixels[i + 0][1], pPixels[i + 0][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel0]);
			sse += bc7_sse(pPixels[i + 1][0], pPixels[i + 1][1], pPixels[i + 1][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel1]);
			sse += bc7_sse(pPixels[i + 2][0], pPixels[i + 2][1], pPixels[i + 2][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel2]);
			sse += bc7_sse(pPixels[i + 3][0], pPixels[i + 3][1], pPixels[i + 3][2], lr, lg, lb, dr, dg, db, basist::g_bc7_weights2[sel3]);
		}

		return sse;
	}

	void eval_weights_mode5_2bit_a(const color_rgba* pPixels, uint8_t* pWeights1, // 2-bits
		int la, int ha)
	{
		int da = ha - la;

		const float f = 3.0f / (float)(da + .00000125f);

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)(pPixels[i + 0][3] - la) * f + .5f);
			int sel1 = (int)((float)(pPixels[i + 1][3] - la) * f + .5f);
			int sel2 = (int)((float)(pPixels[i + 2][3] - la) * f + .5f);
			int sel3 = (int)((float)(pPixels[i + 3][3] - la) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights1[i + 0] = (uint8_t)sel0;
			pWeights1[i + 1] = (uint8_t)sel1;
			pWeights1[i + 2] = (uint8_t)sel2;
			pWeights1[i + 3] = (uint8_t)sel3;
		}
	}

	uint32_t eval_weights_mode5_2bit_a_sse(const color_rgba* pPixels, uint8_t* pWeights1, // 2-bits
		int la, int ha)
	{
		int da = ha - la;

		const float f = 3.0f / (float)(da + .00000125f);

		uint32_t sse = 0;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int sel0 = (int)((float)(pPixels[i + 0][3] - la) * f + .5f);
			int sel1 = (int)((float)(pPixels[i + 1][3] - la) * f + .5f);
			int sel2 = (int)((float)(pPixels[i + 2][3] - la) * f + .5f);
			int sel3 = (int)((float)(pPixels[i + 3][3] - la) * f + .5f);

			if ((uint32_t)sel0 > 3) sel0 = (~sel0 >> 31) & 3;
			if ((uint32_t)sel1 > 3) sel1 = (~sel1 >> 31) & 3;
			if ((uint32_t)sel2 > 3) sel2 = (~sel2 >> 31) & 3;
			if ((uint32_t)sel3 > 3) sel3 = (~sel3 >> 31) & 3;

			pWeights1[i + 0] = (uint8_t)sel0;
			pWeights1[i + 1] = (uint8_t)sel1;
			pWeights1[i + 2] = (uint8_t)sel2;
			pWeights1[i + 3] = (uint8_t)sel3;

			sse += bc7_sse(pPixels[i + 0][3], la, da, basist::g_bc7_weights2[sel0]);
			sse += bc7_sse(pPixels[i + 1][3], la, da, basist::g_bc7_weights2[sel1]);
			sse += bc7_sse(pPixels[i + 2][3], la, da, basist::g_bc7_weights2[sel2]);
			sse += bc7_sse(pPixels[i + 3][3], la, da, basist::g_bc7_weights2[sel3]);
		}

		return sse;
	}

	// Determines the best unique pbits to use to encode xl/xh, which are [0,1]
	static void determine_unique_pbits(
		uint32_t total_comps, uint32_t comp_bits, float xl[4], float xh[4],
		color_rgba& bestMinColor, color_rgba& bestMaxColor, uint32_t best_pbits[2])
	{
#ifdef _DEBUG
		for (uint32_t c = 0; c < total_comps; c++)
		{
			assert((xl[c] >= 0.0f) && (xl[c] <= 1.0f));
			assert((xh[c] >= 0.0f) && (xh[c] <= 1.0f));
		}
#endif

		const uint32_t total_bits = comp_bits + 1;
		const int iscalep = (1 << total_bits) - 1;
		const float scalep = (float)iscalep;

		float best_err0 = 1e+9f;
		float best_err1 = 1e+9f;

		for (int p = 0; p < 2; p++)
		{
			color_rgba xMinColor, xMaxColor;

			for (uint32_t c = 0; c < 4; c++)
			{
				xMinColor[c] = (uint8_t)(clampi(((int)((xl[c] * scalep - p) * (1.0f / 2.0f) + .5f)) * 2 + p, p, iscalep - 1 + p));
				xMaxColor[c] = (uint8_t)(clampi(((int)((xh[c] * scalep - p) * (1.0f / 2.0f) + .5f)) * 2 + p, p, iscalep - 1 + p));
			}

			color_rgba scaledLow, scaledHigh;
			for (uint32_t i = 0; i < 4; i++)
			{
				scaledLow[i] = (xMinColor[i] << (8 - total_bits));
				scaledLow[i] |= (scaledLow[i] >> total_bits);
				assert(scaledLow[i] <= 255);

				scaledHigh[i] = (xMaxColor[i] << (8 - total_bits));
				scaledHigh[i] |= (scaledHigh[i] >> total_bits);
				assert(scaledHigh[i] <= 255);
			}

			float err0 = 0, err1 = 0;
			for (uint32_t i = 0; i < total_comps; i++)
			{
				err0 += basisu::squaref(scaledLow[i] - xl[i] * 255.0f);
				err1 += basisu::squaref(scaledHigh[i] - xh[i] * 255.0f);
			}

			if (err0 < best_err0)
			{
				best_err0 = err0;
				best_pbits[0] = p;

				bestMinColor[0] = xMinColor[0] >> 1;
				bestMinColor[1] = xMinColor[1] >> 1;
				bestMinColor[2] = xMinColor[2] >> 1;
				bestMinColor[3] = xMinColor[3] >> 1;
			}

			if (err1 < best_err1)
			{
				best_err1 = err1;
				best_pbits[1] = p;

				bestMaxColor[0] = xMaxColor[0] >> 1;
				bestMaxColor[1] = xMaxColor[1] >> 1;
				bestMaxColor[2] = xMaxColor[2] >> 1;
				bestMaxColor[3] = xMaxColor[3] >> 1;
			}
		}
	}

	// Determines the best shared pbits to use to encode xl/xh, which are [0,1]
	static void determine_shared_pbits(
		uint32_t total_comps, uint32_t comp_bits, float xl[4], float xh[4],
		color_rgba& bestMinColor, color_rgba& bestMaxColor, uint32_t best_pbits[2])
	{
#ifdef _DEBUG
		for (uint32_t c = 0; c < total_comps; c++)
		{
			assert((xl[c] >= 0.0f) && (xl[c] <= 1.0f));
			assert((xh[c] >= 0.0f) && (xh[c] <= 1.0f));
		}
#endif

		const uint32_t total_bits = comp_bits + 1;
		assert((total_bits >= 4) && (total_bits <= 8));

		const int iscalep = (1 << total_bits) - 1;
		const float scalep = (float)iscalep;

		float best_err = 1e+9f;

		for (int p = 0; p < 2; p++)
		{
			color_rgba xMinColor, xMaxColor;
			for (uint32_t c = 0; c < 4; c++)
			{
				xMinColor[c] = (uint8_t)(clampi(((int)((xl[c] * scalep - p) * (1.0f / 2.0f) + .5f)) * 2 + p, p, iscalep - 1 + p));
				xMaxColor[c] = (uint8_t)(clampi(((int)((xh[c] * scalep - p) * (1.0f / 2.0f) + .5f)) * 2 + p, p, iscalep - 1 + p));
			}

			color_rgba scaledLow, scaledHigh;

			for (uint32_t i = 0; i < 4; i++)
			{
				scaledLow[i] = (xMinColor[i] << (8 - total_bits));
				scaledLow[i] |= (scaledLow[i] >> total_bits);
				assert(scaledLow[i] <= 255);

				scaledHigh[i] = (xMaxColor[i] << (8 - total_bits));
				scaledHigh[i] |= (scaledHigh[i] >> total_bits);
				assert(scaledHigh[i] <= 255);
			}

			float err = 0;
			for (uint32_t i = 0; i < total_comps; i++)
				err += basisu::squaref((scaledLow[i] * (1.0f / 255.0f)) - xl[i]) + basisu::squaref((scaledHigh[i] * (1.0f / 255.0f)) - xh[i]);

			if (err < best_err)
			{
				best_err = err;
				best_pbits[0] = p;
				best_pbits[1] = p;
				for (uint32_t j = 0; j < 4; j++)
				{
					bestMinColor[j] = xMinColor[j] >> 1;
					bestMaxColor[j] = xMaxColor[j] >> 1;
				}
			}
		}
	}

	// 4x4 ASTC blocks only, no dp, no subsets, outputs mode 6
	static void pack_from_astc_4x4_single_subset(uint8_t* pDst_block_u8, const astc_helpers::log_astc_block& log_blk)
	{
		assert(!log_blk.m_dual_plane && (log_blk.m_num_partitions == 1));
		assert((log_blk.m_grid_width <= 4) && (log_blk.m_grid_height <= 4));

		color_rgba l, h;
		astc_ldr_t::decode_endpoints(log_blk.m_color_endpoint_modes[0], log_blk.m_endpoints, log_blk.m_endpoint_ise_range, l, h);

		uint8_t dequantized_weights[16];
		uint8_t upsampled_weights[16];

		const uint32_t total_weight_vals = log_blk.m_grid_width * log_blk.m_grid_height;

		const astc_helpers::dequant_table& weight_dequant_tab = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range);
		const uint8_t* pWeight_dequant = weight_dequant_tab.m_ISE_to_val.data();

		for (uint32_t i = 0; i < total_weight_vals; i++)
		{
			assert(log_blk.m_weights[i] < weight_dequant_tab.m_ISE_to_val.size_u32());
			
			dequantized_weights[i] = pWeight_dequant[log_blk.m_weights[i]];
		}

		const uint8_t* pUpsampled_weights = dequantized_weights;
		if ((log_blk.m_grid_width < 4) || (log_blk.m_grid_height < 4))
		{
			astc_helpers::upsample_weight_grid_xuastc_ldr(4, 4, log_blk.m_grid_width, log_blk.m_grid_height, dequantized_weights, upsampled_weights, nullptr, nullptr);
			pUpsampled_weights = upsampled_weights;
		}

		const float q = 1.0f / 255.0f;
		float sxl[4] = { (float)l.r * q, (float)l.g * q, (float)l.b * q, (float)l.a * q };
		float sxh[4] = { (float)h.r * q, (float)h.g * q, (float)h.b * q, (float)h.a * q };

		color_rgba bestMinColor, bestMaxColor;
		uint32_t best_pbits[2];
		determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

		uint8_t bc7_weights[16];
		// TODO: Potentially improve this mapping using a lookup table
		for (uint32_t i = 0; i < 16; i++)
			bc7_weights[i] = (uint8_t)((pUpsampled_weights[i] * 15 + 32) >> 6);

		encode_mode6_rgba_block(pDst_block_u8,
			bestMinColor.r, bestMinColor.g, bestMinColor.b, bestMinColor.a, best_pbits[0],
			bestMaxColor.r, bestMaxColor.g, bestMaxColor.b, bestMaxColor.a, best_pbits[1],
			bc7_weights);
	}

	// Outputs mode 6
	static void pack_from_astc_single_subset(
		uint8_t* pDst_block_u8, 
		const astc_helpers::log_astc_block& log_blk, 
		const uint8_t *pUpsampled_weights, 
		uint32_t weight_ofs_x, uint32_t weight_ofs_y,
		uint32_t block_width, uint32_t block_height)
	{
		BASISU_NOTE_UNUSED(block_width);
		BASISU_NOTE_UNUSED(block_height);

		assert(!log_blk.m_dual_plane && (log_blk.m_num_partitions == 1));
		assert((log_blk.m_grid_width <= block_width) && (log_blk.m_grid_height <= block_height));
		assert((weight_ofs_x + 3) < block_width);
		assert((weight_ofs_y + 3) < block_height);

		color_rgba l, h;
		astc_ldr_t::decode_endpoints(log_blk.m_color_endpoint_modes[0], log_blk.m_endpoints, log_blk.m_endpoint_ise_range, l, h);

		const float q = 1.0f / 255.0f;
		float sxl[4] = { (float)l.r * q, (float)l.g * q, (float)l.b * q, (float)l.a * q };
		float sxh[4] = { (float)h.r * q, (float)h.g * q, (float)h.b * q, (float)h.a * q };

		color_rgba bestMinColor, bestMaxColor;
		uint32_t best_pbits[2];
		determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

		uint8_t bc7_weights[16];
		
		// TODO: Potentially improve this mapping using a lookup table
		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t w = pUpsampled_weights[(weight_ofs_x + x) + (weight_ofs_y + y) * block_width];
				assert(w <= 64);

				bc7_weights[x + y * 4] = (uint8_t)((w * 15 + 32) >> 6);
			} // x
		} // y

		encode_mode6_rgba_block(pDst_block_u8,
			bestMinColor.r, bestMinColor.g, bestMinColor.b, bestMinColor.a, best_pbits[0],
			bestMaxColor.r, bestMaxColor.g, bestMaxColor.b, bestMaxColor.a, best_pbits[1],
			bc7_weights);
	}

	// same or super close endpoints, 8x6 or 6x6 only
	void pack_from_astc_to_single_subset_same_endpoints(
		uint8_t* pDst_block_u8,
		const astc_helpers::log_astc_block& b0, const uint8_t* pUpsampled_weights0,
		const astc_helpers::log_astc_block& b1, const uint8_t* pUpsampled_weights1,
		int dx, int dy,
		uint32_t block_width, uint32_t block_height)
	{
		assert(!b0.m_dual_plane && (b0.m_num_partitions == 1));
		assert((b0.m_grid_width <= block_width) && (b0.m_grid_height <= block_height));
		assert(!b0.m_solid_color_flag_ldr);

		assert(!b1.m_dual_plane && (b1.m_num_partitions == 1));
		assert((b1.m_grid_width <= block_width) && (b1.m_grid_height <= block_height));
		assert(!b1.m_solid_color_flag_ldr);

		const bool is_6x6 = ((block_width == 6) && (block_height == 6));
		
		// Only handles particular BC7 blocks in the 3x3 or 2x3 region.
		if (is_6x6)
		{
			// 6x6
			assert(
				(!dx && (dy == 1)) || ((dx == 2) && (dy == 1)) ||
				((dx == 1) && !dy) || ((dx == 1) && (dy == 2))
			);
		}
		else
		{
			// 8x6
			assert((block_width == 8) && (block_height == 6));
			assert((dx >= 0) && (dx <= 1));
			assert((dy >= 0) && (dy <= 2));
		}

		color_rgba l, h;
		astc_ldr_t::decode_endpoints(b0.m_color_endpoint_modes[0], b0.m_endpoints, b0.m_endpoint_ise_range, l, h);

		color_rgba al, ah;
		astc_ldr_t::decode_endpoints(b1.m_color_endpoint_modes[0], b1.m_endpoints, b1.m_endpoint_ise_range, al, ah);
		
		for (uint32_t c = 0; c < 4; c++)
		{
			l[c] = (l[c] + al[c] + 1) >> 1;
			h[c] = (h[c] + ah[c] + 1) >> 1;
		}

		const float q = 1.0f / 255.0f;
		float sxl[4] = { (float)l.r * q, (float)l.g * q, (float)l.b * q, (float)l.a * q };
		float sxh[4] = { (float)h.r * q, (float)h.g * q, (float)h.b * q, (float)h.a * q };

		color_rgba bestMinColor, bestMaxColor;
		uint32_t best_pbits[2];
		determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

		bool top_or_bottom = false;
		
		if (is_6x6)
			top_or_bottom = (dy == 0) || (dy == 2);
				
		uint8_t bc7_weights[16];

		// TODO: Potentially improve this mapping using a lookup table
		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t w;

				if (is_6x6)
				{
					if (top_or_bottom)
					{
						if (x < 2)
							w = pUpsampled_weights0[basisu::open_range_check<int>((x + 4) + (y + ((dy == 2) ? 2 : 0)) * 6, 0, 36)];
						else
							w = pUpsampled_weights1[basisu::open_range_check<int>((x - 2) + (y + ((dy == 2) ? 2 : 0)) * 6, 0, 36)];
					}
					else
					{
						if (y < 2)
							w = pUpsampled_weights0[basisu::open_range_check<int>((x + ((dx == 2) ? 2 : 0)) + (y + 4) * 6, 0, 36)];
						else
							w = pUpsampled_weights1[basisu::open_range_check<int>((x + ((dx == 2) ? 2 : 0)) + (y - 2) * 6, 0, 36)];
					}
				}
				else
				{
					// 8x6
					if (y < 2)
						w = pUpsampled_weights0[basisu::open_range_check<int>((dx * 4 + x) + (y + 4) * 8, 0, 48)];
					else
						w = pUpsampled_weights1[basisu::open_range_check<int>((dx * 4 + x) + (y - 2) * 8, 0, 48)];
				}

				assert(w <= 64);

				bc7_weights[x + y * 4] = (uint8_t)((w * 15 + 32) >> 6);
			} // x
		} // y

		encode_mode6_rgba_block(pDst_block_u8,
			bestMinColor.r, bestMinColor.g, bestMinColor.b, bestMinColor.a, best_pbits[0],
			bestMaxColor.r, bestMaxColor.g, bestMaxColor.b, bestMaxColor.a, best_pbits[1],
			bc7_weights);
	}

	bool pack_from_astc_6x6_to_two_subsets_different_endpoints(
		uint8_t *pDst_block_u8,
		const astc_helpers::log_astc_block& b0, const uint8_t* pUpsampled_weights0,
		const astc_helpers::log_astc_block& b1, const uint8_t* pUpsampled_weights1,
		int dx, int dy)
	{
		const bool b0_solid = b0.m_solid_color_flag_ldr;
		const bool b1_solid = b1.m_solid_color_flag_ldr;

		assert(b0_solid || (!b0.m_dual_plane && (b0.m_num_partitions == 1)));
		assert((b0.m_grid_width <= 6) && (b0.m_grid_height <= 6));
		
		assert(b1_solid || (!b1.m_dual_plane && (b1.m_num_partitions == 1)));
		assert((b1.m_grid_width <= 6) && (b1.m_grid_height <= 6));
		
		// Only handles particular BC7 blocks in the 3x3 region.
		assert(
			(!dx && (dy == 1)) || ((dx == 2) && (dy == 1)) ||
			((dx == 1) && !dy) || ((dx == 1) && (dy == 2))
		);
				
		color_rgba l[2], h[2];
		if (b0_solid)
		{
			l[0][0] = h[0][0] = (uint8_t)(b0.m_solid_color[0] >> 8);
			l[0][1] = h[0][1] = (uint8_t)(b0.m_solid_color[1] >> 8);
			l[0][2] = h[0][2] = (uint8_t)(b0.m_solid_color[2] >> 8);
			l[0][3] = h[0][3] = (uint8_t)(b0.m_solid_color[3] >> 8);
		}
		else
		{
			astc_ldr_t::decode_endpoints(b0.m_color_endpoint_modes[0], b0.m_endpoints, b0.m_endpoint_ise_range, l[0], h[0]);
		}

		if (b1_solid)
		{
			l[1][0] = h[1][0] = (uint8_t)(b1.m_solid_color[0] >> 8);
			l[1][1] = h[1][1] = (uint8_t)(b1.m_solid_color[1] >> 8);
			l[1][2] = h[1][2] = (uint8_t)(b1.m_solid_color[2] >> 8);
			l[1][3] = h[1][3] = (uint8_t)(b1.m_solid_color[3] >> 8);
		}
		else
		{
			astc_ldr_t::decode_endpoints(b1.m_color_endpoint_modes[0], b1.m_endpoints, b1.m_endpoint_ise_range, l[1], h[1]);
		}

		float sxl[2][4], sxh[2][4];
		for (uint32_t i = 0; i < 2; i++)
		{
			for (uint32_t j = 0; j < 4; j++)
			{
				const float q = 1.0f / 255.0f;

				sxl[i][j] = l[i][j] * q;
				sxh[i][j] = h[i][j] * q;
			} // j
		} // i

		color_rgba bestMinColor[2], bestMaxColor[2];
		
		uint32_t best_p0[2];
		determine_shared_pbits(3, 6, sxl[0], &sxh[0][0], bestMinColor[0], bestMaxColor[0], best_p0);
		
		uint32_t best_p1[2];
		determine_shared_pbits(3, 6, sxl[1], &sxh[1][0], bestMinColor[1], bestMaxColor[1], best_p1);

		const bool top_or_bottom = (dy == 0) || (dy == 2);

		uint8_t bc7_weights[16];

		uint32_t part_id = 0;
		if ((dx == 0) || (dx == 2))
			part_id = 13;

#if 0
		const uint8_t* pPart_map = &g_bc7_partition2[part_id * 16];
		uint32_t min_qw[2] = { 256, 256 }, max_qw[2] = { 0, 0 };
#endif
				
		// TODO: Potentially improve this mapping using a lookup table
		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t w;

				if (top_or_bottom)
				{
					if (x < 2)
						w = b0_solid ? 0 : pUpsampled_weights0[basisu::open_range_check<int>((x + 4) + (y + ((dy == 2) ? 2 : 0)) * 6, 0, 36)];
					else
						w = b1_solid ? 0 : pUpsampled_weights1[basisu::open_range_check<int>((x - 2) + (y + ((dy == 2) ? 2 : 0)) * 6, 0, 36)];
				}
				else
				{
					if (y < 2)
						w = b0_solid ? 0 : pUpsampled_weights0[basisu::open_range_check<int>((x + ((dx == 2) ? 2 : 0)) + (y + 4) * 6, 0, 36)];
					else
						w = b1_solid ? 0 : pUpsampled_weights1[basisu::open_range_check<int>((x + ((dx == 2) ? 2 : 0)) + (y - 2) * 6, 0, 36)];
				}

				assert(w <= 64);

				uint32_t qw = ((w * 7 + 32) >> 6);

#if 0
				const uint8_t s = pPart_map[x + y * 4];
				min_qw[s] = basisu::minimum(min_qw[s], qw);
				max_qw[s] = basisu::maximum(max_qw[s], qw);
#endif

				bc7_weights[x + y * 4] = (uint8_t)qw;
			} // x
		} // y
				
#if 0
		const uint32_t w_range_0 = max_qw[0] - min_qw[0];
		const uint32_t w_range_1 = max_qw[1] - min_qw[1];
		const uint32_t W_RANGE_THRESH = 2;
		if ((w_range_0 <= W_RANGE_THRESH) || (w_range_1 <= W_RANGE_THRESH))
			return false;
#endif
		
		uint32_t lr[2] = { bestMinColor[0][0], bestMinColor[1][0] };
		uint32_t lg[2] = { bestMinColor[0][1], bestMinColor[1][1] };
		uint32_t lb[2] = { bestMinColor[0][2], bestMinColor[1][2] };
		
		uint32_t hr[2] = { bestMaxColor[0][0], bestMaxColor[1][0] };
		uint32_t hg[2] = { bestMaxColor[0][1], bestMaxColor[1][1] };
		uint32_t hb[2] = { bestMaxColor[0][2], bestMaxColor[1][2] };

		encode_mode1_rgb_block(pDst_block_u8, part_id,
			lr, lg, lb,
			hr, hg, hb,
			best_p0[0], best_p1[0],
			bc7_weights);

		return true;
	}

	bool pack_from_astc_8x6_to_two_subsets_different_endpoints(
		uint8_t* pDst_block_u8,
		const astc_helpers::log_astc_block& b0, const uint8_t* pUpsampled_weights0,
		const astc_helpers::log_astc_block& b1, const uint8_t* pUpsampled_weights1,
		int dx, int dy)
	{
		BASISU_NOTE_UNUSED(dy);

		const bool b0_solid = b0.m_solid_color_flag_ldr;
		const bool b1_solid = b1.m_solid_color_flag_ldr;

		assert(b0_solid || (!b0.m_dual_plane && (b0.m_num_partitions == 1)));
		assert((b0.m_grid_width <= 8) && (b0.m_grid_height <= 6));

		assert(b1_solid || (!b1.m_dual_plane && (b1.m_num_partitions == 1)));
		assert((b1.m_grid_width <= 8) && (b1.m_grid_height <= 6));

		// Only handles particular BC7 blocks in the 2x3 region.
		assert((dx >= 0) && (dx <= 1) && 
			(dy >= 0) && (dy <= 2));

		color_rgba l[2], h[2];
		if (b0_solid)
		{
			l[0][0] = h[0][0] = (uint8_t)(b0.m_solid_color[0] >> 8);
			l[0][1] = h[0][1] = (uint8_t)(b0.m_solid_color[1] >> 8);
			l[0][2] = h[0][2] = (uint8_t)(b0.m_solid_color[2] >> 8);
			l[0][3] = h[0][3] = (uint8_t)(b0.m_solid_color[3] >> 8);
		}
		else
		{
			astc_ldr_t::decode_endpoints(b0.m_color_endpoint_modes[0], b0.m_endpoints, b0.m_endpoint_ise_range, l[0], h[0]);
		}

		if (b1_solid)
		{
			l[1][0] = h[1][0] = (uint8_t)(b1.m_solid_color[0] >> 8);
			l[1][1] = h[1][1] = (uint8_t)(b1.m_solid_color[1] >> 8);
			l[1][2] = h[1][2] = (uint8_t)(b1.m_solid_color[2] >> 8);
			l[1][3] = h[1][3] = (uint8_t)(b1.m_solid_color[3] >> 8);
		}
		else
		{
			astc_ldr_t::decode_endpoints(b1.m_color_endpoint_modes[0], b1.m_endpoints, b1.m_endpoint_ise_range, l[1], h[1]);
		}

		float sxl[2][4], sxh[2][4];
		for (uint32_t i = 0; i < 2; i++)
		{
			for (uint32_t j = 0; j < 4; j++)
			{
				const float q = 1.0f / 255.0f;

				sxl[i][j] = l[i][j] * q;
				sxh[i][j] = h[i][j] * q;
			} // j
		} // i

		color_rgba bestMinColor[2], bestMaxColor[2];

		uint32_t best_p0[2];
		determine_shared_pbits(3, 6, sxl[0], &sxh[0][0], bestMinColor[0], bestMaxColor[0], best_p0);

		uint32_t best_p1[2];
		determine_shared_pbits(3, 6, sxl[1], &sxh[1][0], bestMinColor[1], bestMaxColor[1], best_p1);
				
		uint8_t bc7_weights[16];

		uint32_t part_id = 13;

		// TODO: Potentially improve this mapping using a lookup table
		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t w;

				if (y < 2)
					w = b0_solid ? 0 : pUpsampled_weights0[basisu::open_range_check<int>((dx * 4 + x) + (y + 4) * 8, 0, 48)];
				else
					w = b1_solid ? 0 : pUpsampled_weights1[basisu::open_range_check<int>((dx * 4 + x) + (y - 2) * 8, 0, 48)];

				assert(w <= 64);

				uint32_t qw = ((w * 7 + 32) >> 6);

				bc7_weights[x + y * 4] = (uint8_t)qw;
			} // x
		} // y

		uint32_t lr[2] = { bestMinColor[0][0], bestMinColor[1][0] };
		uint32_t lg[2] = { bestMinColor[0][1], bestMinColor[1][1] };
		uint32_t lb[2] = { bestMinColor[0][2], bestMinColor[1][2] };

		uint32_t hr[2] = { bestMaxColor[0][0], bestMaxColor[1][0] };
		uint32_t hg[2] = { bestMaxColor[0][1], bestMaxColor[1][1] };
		uint32_t hb[2] = { bestMaxColor[0][2], bestMaxColor[1][2] };

		encode_mode1_rgb_block(pDst_block_u8, part_id,
			lr, lg, lb,
			hr, hg, hb,
			best_p0[0], best_p1[0],
			bc7_weights);

		return true;
	}

	uint32_t fast_pack_bc7_rgb_partial_analytical(uint8_t* pBlock, const color_rgba* pPixels, uint32_t flags);
		
	bool pack_from_astc_8x6_to_two_subsets_different_endpoints_hq(
		uint8_t* pDst_block_u8,
		const astc_helpers::log_astc_block& b0, const uint8_t* pUpsampled_weights0,
		const astc_helpers::log_astc_block& b1, const uint8_t* pUpsampled_weights1,
		int dx, int dy, bool astc_srgb_decode, bool &fallback_encode_flag)
	{
		BASISU_NOTE_UNUSED(dy);

		const bool b_solid[2] = { b0.m_solid_color_flag_ldr, b1.m_solid_color_flag_ldr };

		assert(b_solid[0] || (!b0.m_dual_plane && (b0.m_num_partitions == 1)));
		assert((b0.m_grid_width <= 8) && (b0.m_grid_height <= 6));

		assert(b_solid[1] || (!b1.m_dual_plane && (b1.m_num_partitions == 1)));
		assert((b1.m_grid_width <= 8) && (b1.m_grid_height <= 6));

		// Only handles particular BC7 blocks in the 2x3 region.
		assert((dx >= 0) && (dx <= 1) &&
			(dy >= 0) && (dy <= 2));

		color_rgba l[2], h[2];
		if (b_solid[0])
		{
			l[0][0] = h[0][0] = (uint8_t)(b0.m_solid_color[0] >> 8);
			l[0][1] = h[0][1] = (uint8_t)(b0.m_solid_color[1] >> 8);
			l[0][2] = h[0][2] = (uint8_t)(b0.m_solid_color[2] >> 8);
			l[0][3] = h[0][3] = (uint8_t)(b0.m_solid_color[3] >> 8);
		}
		else
		{
			astc_ldr_t::decode_endpoints(b0.m_color_endpoint_modes[0], b0.m_endpoints, b0.m_endpoint_ise_range, l[0], h[0]);
		}

		if (b_solid[1])
		{
			l[1][0] = h[1][0] = (uint8_t)(b1.m_solid_color[0] >> 8);
			l[1][1] = h[1][1] = (uint8_t)(b1.m_solid_color[1] >> 8);
			l[1][2] = h[1][2] = (uint8_t)(b1.m_solid_color[2] >> 8);
			l[1][3] = h[1][3] = (uint8_t)(b1.m_solid_color[3] >> 8);
		}
		else
		{
			astc_ldr_t::decode_endpoints(b1.m_color_endpoint_modes[0], b1.m_endpoints, b1.m_endpoint_ise_range, l[1], h[1]);
		}

		uint32_t low_w[2] = { UINT32_MAX, UINT32_MAX };
		uint32_t high_w[2] = { 0, 0 };

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s;
				uint32_t w;

				if (y < 2)
				{
					w = b_solid[0] ? 0 : pUpsampled_weights0[basisu::open_range_check<int>((dx * 4 + x) + (y + 4) * 8, 0, 48)];
					s = 0;
				}
				else
				{
					w = b_solid[1] ? 0 : pUpsampled_weights1[basisu::open_range_check<int>((dx * 4 + x) + (y - 2) * 8, 0, 48)];
					s = 1;
				}

				assert(w <= 64);

				low_w[s] = basisu::minimum<uint32_t>(low_w[s], w);
				high_w[s] = basisu::maximum<uint32_t>(high_w[s], w);
			} // x
		} // y

		color_rgba orig_l[2], orig_h[2];
		memcpy(orig_l, l, sizeof(l));
		memcpy(orig_h, h, sizeof(h));

#if 1
		uint32_t num_low_stddev = 0;
#endif

		for (uint32_t s = 0; s < 2; s++)
		{
			if (b_solid[s])
				continue;

			if ((low_w[s] > 0) || (high_w[s] < 64))
			{
				for (uint32_t c = 0; c < 3; c++)
				{
					l[s][c] = (uint8_t)astc_helpers::channel_interpolate(orig_l[s][c], orig_h[s][c], low_w[s], astc_srgb_decode);
					h[s][c] = (uint8_t)astc_helpers::channel_interpolate(orig_l[s][c], orig_h[s][c], high_w[s], astc_srgb_decode);
				}
			}

#if 1
			uint32_t e_delta = basisu::squarei((int)h[s][0] - (int)l[s][0]) + 
				basisu::squarei((int)h[s][1] - (int)l[s][1]) + 
				basisu::squarei((int)h[s][2] - (int)l[s][2]);

			const uint32_t E_DELTA_THRESH = 60;
			num_low_stddev += (e_delta < E_DELTA_THRESH);
#endif
		}

#if 1
		if (num_low_stddev == 2)
		{
			//bc7f::pack_mode5_solid(pDst_block_u8, color_rgba(200, 0, 0, 255));
			//return true;

			assert(!b_solid[0] && !b_solid[1]);

			color_rgba dec_pixels[16];
						
			int ep_l[2][3], ep_h[2][3];
			for (uint32_t s = 0; s < 2; s++)
			{
				for (uint32_t c = 0; c < 3; c++)
				{
					int le = l[s][c], he = h[s][c];

					if (astc_srgb_decode)
					{
						le = (le << 8) | 0x80;
						he = (he << 8) | 0x80;
					}
					else
					{
						le = (le << 8) | le;
						he = (he << 8) | he;
					}

					ep_l[s][c] = le;
					ep_h[s][c] = he;
				}
			}

			color_rgba* pDst = dec_pixels;
			for (uint32_t y = 0; y < 4; y++)
			{
				for (uint32_t x = 0; x < 4; x++)
				{
					uint32_t s = (y < 2) ? 0 : 1;

					int w;
					if (y < 2)
						w = pUpsampled_weights0[basisu::open_range_check<int>((dx * 4 + x) + (y + 4) * 8, 0, 48)];
					else
						w = pUpsampled_weights1[basisu::open_range_check<int>((dx * 4 + x) + (y - 2) * 8, 0, 48)];

					pDst->r = (uint8_t)(astc_helpers::weight_interpolate(ep_l[s][0], ep_h[s][0], w) >> 8);
					pDst->g = (uint8_t)(astc_helpers::weight_interpolate(ep_l[s][1], ep_h[s][1], w) >> 8);
					pDst->b = (uint8_t)(astc_helpers::weight_interpolate(ep_l[s][2], ep_h[s][2], w) >> 8);
					pDst->a = 255;
					
					++pDst;

				} // x
			} // y

			const uint32_t flags = cPackBC7FlagUseTrivialMode6 | cPackBC7FlagPBitOptMode6;
			//const uint32_t flags = cPackBC7FlagUse2SubsetsRGB | cPackBC7FlagPBitOpt | cPackBC7FlagPBitOptMode6 | cPackBC7FlagUseTrivialMode6;
			bc7f::fast_pack_bc7_rgb_analytical(pDst_block_u8, dec_pixels, flags);
			fallback_encode_flag = true;
			return true;
		}
#endif

		float sxl[2][4], sxh[2][4];
		for (uint32_t i = 0; i < 2; i++)
		{
			for (uint32_t j = 0; j < 4; j++)
			{
				const float q = 1.0f / 255.0f;

				sxl[i][j] = (float)l[i][j] * q;
				sxh[i][j] = (float)h[i][j] * q;
			} // j
		} // i

		color_rgba bestMinColor[2], bestMaxColor[2];

		uint32_t best_p0[2];
		determine_shared_pbits(3, 6, sxl[0], &sxh[0][0], bestMinColor[0], bestMaxColor[0], best_p0);

		uint32_t best_p1[2];
		determine_shared_pbits(3, 6, sxl[1], &sxh[1][0], bestMinColor[1], bestMaxColor[1], best_p1);

		uint8_t bc7_weights[16];

		uint32_t part_id = 13;

		float one_over_w_range_scaled[2];
		for (uint32_t s = 0; s < 2; s++)
		{
			if (low_w[s] == high_w[s])
				one_over_w_range_scaled[s] = 0;
			else
				one_over_w_range_scaled[s] = 7.0f / (high_w[s] - low_w[s]);
		}

		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t s = (y < 2) ? 0 : 1;
				
				int qw = 0;

				if (!b_solid[s])
				{
					int w;

					if (y < 2)
						w = pUpsampled_weights0[basisu::open_range_check<int>((dx * 4 + x) + (y + 4) * 8, 0, 48)];
					else
						w = pUpsampled_weights1[basisu::open_range_check<int>((dx * 4 + x) + (y - 2) * 8, 0, 48)];

					assert(w <= 64);
										
					if (low_w[s] != high_w[s])
					{
						float f = ((float)w - (float)low_w[s]) * one_over_w_range_scaled[s];
						
						qw = (int)(f + .5f);

						if ((uint32_t)qw > 7)
						{
							qw = basisu::clamp<int>(qw, 0, 7);
						}
					}
				}

				bc7_weights[x + y * 4] = (uint8_t)qw;
			} // x
		} // y

		uint32_t lr[2] = { bestMinColor[0][0], bestMinColor[1][0] };
		uint32_t lg[2] = { bestMinColor[0][1], bestMinColor[1][1] };
		uint32_t lb[2] = { bestMinColor[0][2], bestMinColor[1][2] };

		uint32_t hr[2] = { bestMaxColor[0][0], bestMaxColor[1][0] };
		uint32_t hg[2] = { bestMaxColor[0][1], bestMaxColor[1][1] };
		uint32_t hb[2] = { bestMaxColor[0][2], bestMaxColor[1][2] };

		encode_mode1_rgb_block(pDst_block_u8, part_id,
			lr, lg, lb,
			hr, hg, hb,
			best_p0[0], best_p1[0],
			bc7_weights);

		return true;
	}

	void pack_astc_6x6_to_two_subsets_middle_block(
		uint8_t* pDst_block_u8,
		const astc_helpers::log_astc_block* blocks[2][2],
		const uint8_t(&weights)[2][2][36],
		bool do_left_right)
	{
		const astc_helpers::log_astc_block* p[2];
		const astc_helpers::log_astc_block* q[2];

		if (do_left_right)
		{
			// left and right into separate subsets
			p[0] = blocks[0][0];
			q[0] = blocks[0][1];

			p[1] = blocks[1][0];
			q[1] = blocks[1][1];
		}
		else
		{
			// top and bottom into separate subsets
			p[0] = blocks[0][0];
			q[0] = blocks[1][0];

			p[1] = blocks[0][1];
			q[1] = blocks[1][1];
		}

		assert(p[0]->m_solid_color_flag_ldr || (!p[0]->m_dual_plane && (p[0]->m_num_partitions == 1)));
		assert((p[0]->m_grid_width <= 6) && (p[0]->m_grid_height <= 6));

		assert(p[1]->m_solid_color_flag_ldr || (!p[1]->m_dual_plane && (p[1]->m_num_partitions == 1)));
		assert((p[1]->m_grid_width <= 6) && (p[1]->m_grid_height <= 6));

		assert(q[0]->m_solid_color_flag_ldr || (!q[0]->m_dual_plane && (q[0]->m_num_partitions == 1)));
		assert((q[0]->m_grid_width <= 6) && (q[0]->m_grid_height <= 6));

		assert(q[1]->m_solid_color_flag_ldr || (!q[1]->m_dual_plane && (q[1]->m_num_partitions == 1)));
		assert((q[1]->m_grid_width <= 6) && (q[1]->m_grid_height <= 6));

		color_rgba el[2], eh[2];
		color_rgba el2[2], eh2[2];

		for (uint32_t i = 0; i < 2; i++)
		{
			if (p[i]->m_solid_color_flag_ldr)
			{
				el[i][0] = eh[i][0] = (uint8_t)(p[i]->m_solid_color[0] >> 8);
				el[i][1] = eh[i][1] = (uint8_t)(p[i]->m_solid_color[1] >> 8);
				el[i][2] = eh[i][2] = (uint8_t)(p[i]->m_solid_color[2] >> 8);
				el[i][3] = eh[i][3] = (uint8_t)(p[i]->m_solid_color[3] >> 8);
			}
			else
			{
				astc_ldr_t::decode_endpoints(p[i]->m_color_endpoint_modes[0], p[i]->m_endpoints, p[i]->m_endpoint_ise_range, el[i], eh[i]);
			}

			if (q[i]->m_solid_color_flag_ldr)
			{
				el2[i][0] = eh2[i][0] = (uint8_t)(q[i]->m_solid_color[0] >> 8);
				el2[i][1] = eh2[i][1] = (uint8_t)(q[i]->m_solid_color[1] >> 8);
				el2[i][2] = eh2[i][2] = (uint8_t)(q[i]->m_solid_color[2] >> 8);
				el2[i][3] = eh2[i][3] = (uint8_t)(q[i]->m_solid_color[3] >> 8);
			}
			else
			{
				astc_ldr_t::decode_endpoints(q[i]->m_color_endpoint_modes[0], q[i]->m_endpoints, q[i]->m_endpoint_ise_range, el2[i], eh2[i]);
			}

			assert(el[i][3] == 255);
			assert(el2[i][3] == 255);
			
			assert(eh[i][3] == 255);
			assert(eh2[i][3] == 255);
		}

		for (uint32_t i = 0; i < 2; i++)
		{
			for (uint32_t c = 0; c < 3; c++)
			{
				el[i][c] = (el[i][c] + el2[i][c] + 1) >> 1;
				eh[i][c] = (eh[i][c] + eh2[i][c] + 1) >> 1;
			} // c
		} // i
		
		float sxl[2][4], sxh[2][4];
		for (uint32_t i = 0; i < 2; i++)
		{
			for (uint32_t j = 0; j < 4; j++)
			{
				const float S = 1.0f / 255.0f;

				sxl[i][j] = el[i][j] * S;
				sxh[i][j] = eh[i][j] * S;
			} // j
		} // i

		color_rgba bestMinColor[2], bestMaxColor[2];

		uint32_t best_p0[2];
		determine_shared_pbits(3, 6, sxl[0], &sxh[0][0], bestMinColor[0], bestMaxColor[0], best_p0);

		uint32_t best_p1[2];
		determine_shared_pbits(3, 6, sxl[1], &sxh[1][0], bestMinColor[1], bestMaxColor[1], best_p1);

		uint8_t bc7_weights[16];

		// TODO: Potentially improve this mapping using a lookup table
		for (uint32_t y = 0; y < 4; y++)
		{
			for (uint32_t x = 0; x < 4; x++)
			{
				uint32_t w = 0;

				if (y < 2)
				{
					if (x < 2)
					{
						if (!blocks[0][0]->m_solid_color_flag_ldr)
							w = weights[0][0][(x + 4) + (y + 4) * 6];
					}
					else 
					{
						if (!blocks[1][0]->m_solid_color_flag_ldr)
							w = weights[1][0][(x - 2) + (y + 4) * 6];
					}
				}
				else
				{
					if (x < 2)
					{
						if (!blocks[0][1]->m_solid_color_flag_ldr)
							w = weights[0][1][(x + 4) + (y - 2) * 6];
					}
					else
					{
						if (!blocks[1][1]->m_solid_color_flag_ldr)
							w = weights[1][1][(x - 2) + (y - 2) * 6];
					}
				}
				
				assert(w <= 64);

				bc7_weights[x + y * 4] = (uint8_t)((w * 7 + 32) >> 6);
			} // x
		} // y
		
		uint32_t part_id = 13;
		if (do_left_right)
			part_id = 0;

		uint32_t lr[2] = { bestMinColor[0][0], bestMinColor[1][0] };
		uint32_t lg[2] = { bestMinColor[0][1], bestMinColor[1][1] };
		uint32_t lb[2] = { bestMinColor[0][2], bestMinColor[1][2] };

		uint32_t hr[2] = { bestMaxColor[0][0], bestMaxColor[1][0] };
		uint32_t hg[2] = { bestMaxColor[0][1], bestMaxColor[1][1] };
		uint32_t hb[2] = { bestMaxColor[0][2], bestMaxColor[1][2] };

		encode_mode1_rgb_block(pDst_block_u8, part_id,
			lr, lg, lb,
			hr, hg, hb,
			best_p0[0], best_p1[0],
			bc7_weights);
	}

#if 0
	// var must be variance (divided by N, # pixels), not SSE
	static inline int calc_span_est(int min_c, int max_c, int mean_c, float var)
	{
		// variance-implied span: span_var = ~sqrt(12 * var)
		int span_var = (int)fast_roundf_pos_int(std::sqrtf((float)(12.0f * var)));

		// take into account available headroom on the low/high end
		span_var = basisu::minimum<int>(span_var, 2 * basisu::minimum<int>(mean_c, 255 - mean_c));

		return basisu::minimum<int>(max_c - min_c, span_var);
	}
#endif

// doesn't seem to be a net win in quick testing, unlike ASTC
#define BASIST_USE_ALT_WEIGHT_QUANT_EST (0)

	// Multi-channel estimates
	// returns total SSE (pixel SSE * num_pixels), span_weights can be nullptr
	float analytical_quant_est_sse(int e_levels, int w_levels, int num_chans, const int spans[4], const float span_weights[4], float endpoint_weight_scale, int num_pixels)
	{
		assert((e_levels >= 2) && (e_levels <= 256) && (w_levels >= 2) && (num_chans));
		assert(spans);

		const float Dep = 1.0f / (float)(e_levels - 1); // endpoint quant step
#if BASIST_USE_ALT_WEIGHT_QUANT_EST
		const float Dw = 1.0f / (float)(w_levels); // weight quant step
#else
		const float Dw = 1.0f / (float)(w_levels - 1); // weight quant step
#endif

		// TODO: precompute
		const float N = float(w_levels);
		const float ab_sum = (2.0f * N - 1.0f) / (3.0f * (N - 1.0f));

		float pixel_sse = (e_levels == 256) ? 0.0f : ((Dep * Dep) * ((1.0f / 12.0f) * ab_sum * (255.0f * 255.0f)) * (float)num_chans * endpoint_weight_scale);

		const float k = (Dw * Dw) * (1.0f / 12.0f);
		for (int i = 0; i < num_chans; i++)
		{
			pixel_sse += k * (float)(spans[i] * spans[i]) * (span_weights ? span_weights[i] : 1.0f);
		}

		return pixel_sse * float(num_pixels);
	}

	// Single channel estimates
	float analytical_quant_est_sse(int e_levels, int w_levels, int span, float span_weight, float endpoint_weight_scale, int num_pixels)
	{
		assert((e_levels >= 2) && (e_levels <= 256) && (w_levels >= 2));

		const float Dep = 1.0f / (float)(e_levels - 1); // endpoint quant step
#if BASIST_USE_ALT_WEIGHT_QUANT_EST
		const float Dw = 1.0f / (float)(w_levels); // weight quant step
#else
		const float Dw = 1.0f / (float)(w_levels - 1); // weight quant step
#endif

		// TODO: precompute
		const float N = float(w_levels);
		const float ab_sum = (2.0f * N - 1.0f) / (3.0f * (N - 1.0f));

		float pixel_sse = (e_levels == 256) ? 0.0f : ((Dep * Dep) * ((1.0f / 12.0f) * ab_sum * (255.0f * 255.0f)) * endpoint_weight_scale);

		pixel_sse += (Dw * Dw) * (1.0f / 12.0f) * (float)(span * span) * span_weight;

		return pixel_sse * float(num_pixels);
	}

	// if cov[] wasn't divided by the # of pixels, this is SSE
	float estimate_slam_to_line_sse_3D(const float cov[6], float xr, float yr, float zr, float* pOrtho_ratio = nullptr)
	{
		// total var
		const float total_var = cov[0] + cov[3] + cov[5];

		float l = sqrtf(xr * xr + yr * yr + zr * zr);
		if (l < basisu::SMALL_FLOAT_VAL)
		{
			xr = yr = zr = 0.577350269f;
		}
		else
		{
			l = 1.0f / l;
			xr *= l; yr *= l; zr *= l;
		}

		float xr2 = cov[0] * xr + cov[1] * yr + cov[2] * zr;
		float xg2 = cov[1] * xr + cov[3] * yr + cov[4] * zr;
		float xb2 = cov[2] * xr + cov[4] * yr + cov[5] * zr;

		// Rayleigh quotient/est var of principal axis
		const float principal_axis_var = xr2 * xr + xg2 * yr + xb2 * zr;

		// Compute leftover var, this is the var unexplaind by the principal axis
		const float ortho_var = basisu::maximum(0.0f, total_var - principal_axis_var);

		if (pOrtho_ratio)
			*pOrtho_ratio = (total_var > basisu::SMALL_FLOAT_VAL) ? (ortho_var / total_var) : 0.0f;

		return ortho_var;
	}

	float estimate_slam_to_line_sse_4D(const float cov[10], float xr, float yr, float zr, float wr, float* pOrtho_ratio = nullptr)
	{
		// total var
		const float total_var = cov[0] + cov[4] + cov[7] + cov[9];

		float l = sqrtf(xr * xr + yr * yr + zr * zr + wr * wr);
		if (l < basisu::SMALL_FLOAT_VAL)
		{
			xr = yr = zr = wr = .5f;
		}
		else
		{
			l = 1.0f / l;
			xr *= l; yr *= l; zr *= l; wr *= l;
		}

		float xr2 = cov[0] * xr + cov[1] * yr + cov[2] * zr + cov[3] * wr;
		float xg2 = cov[1] * xr + cov[4] * yr + cov[5] * zr + cov[6] * wr;
		float xb2 = cov[2] * xr + cov[5] * yr + cov[7] * zr + cov[8] * wr;
		float xa2 = cov[3] * xr + cov[6] * yr + cov[8] * zr + cov[9] * wr;

		// Rayleigh quotient/est var of principal axis
		const float principal_axis_var = xr2 * xr + xg2 * yr + xb2 * zr + xa2 * wr;

		// Compute leftover var, this is the var unexplaind by the principal axis
		const float ortho_var = basisu::maximum(0.0f, total_var - principal_axis_var);

		if (pOrtho_ratio)
			*pOrtho_ratio = (total_var > basisu::SMALL_FLOAT_VAL) ? (ortho_var / total_var) : 0.0f;

		return ortho_var;
	}

	uint32_t calc_sse(const uint8_t* pBlock, const color_rgba* pPixels)
	{
		color_rgba unpacked_pixels[16];
		bool status = bc7u::unpack_bc7(pBlock, unpacked_pixels);
		if (!status)
		{
			assert(0);
			return UINT32_MAX;
		}

		uint32_t sse = 0;
		for (uint32_t i = 0; i < 16; i++)
			sse += basisu::squarei(pPixels[i][0] - unpacked_pixels[i][0]) + basisu::squarei(pPixels[i][1] - unpacked_pixels[i][1]) + basisu::squarei(pPixels[i][2] - unpacked_pixels[i][2]) + basisu::squarei(pPixels[i][3] - unpacked_pixels[i][3]);

		return sse;
	}

	bool pack_mode1_or_3_rgb(uint8_t* pBlock, const color_rgba* pPixels,
		float block_xr, float block_xg, float block_xb,
		int block_mean_r, int block_mean_g, int block_mean_b,
		float sse_est_to_beat, uint32_t flags,
		float* pFinal_sse_est = nullptr,
		uint32_t* pActual_sse = nullptr)
	{
#if BASISU_BC7F_PERF_STATS
		g_total_mode13_evals++;
#endif

		uint32_t desired_pat_bits = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const float r = (float)(pPixels[i].r - block_mean_r);
			const float g = (float)(pPixels[i].g - block_mean_g);
			const float b = (float)(pPixels[i].b - block_mean_b);

			const uint32_t subset = (r * block_xr + g * block_xg + b * block_xb) > 0.0f;

			desired_pat_bits |= (subset << i);
		}

		uint32_t best_diff = UINT32_MAX;

		if (flags & cPackBC7FlagASTCCompatible)
		{
			// We're actually encoding to ASTC 4x4, so we can only check the 2-subset patterns in common between BC7 and ASTC (the UASTC LDR 4x4 patterns).
			for (uint32_t c = 0; c < TOTAL_ASTC_BC7_COMMON_PARTITIONS2; c++)
			{
				const uint32_t p = g_astc_bc7_common_partitions2[c].m_bc7;

				const uint32_t bc6h_pat_bits = g_bc7_part2_bitmasks[p];

				int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
				int diff_inv = 16 - diff;

				uint32_t min_diff = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
				if (min_diff < best_diff)
					best_diff = min_diff;
			} // p
		}
		else
		{
			for (uint32_t p = 0; p < MAX_PATTERNS2_TO_CHECK; p++)
			{
				const uint32_t bc6h_pat_bits = g_bc7_part2_bitmasks[p];

				int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
				int diff_inv = 16 - diff;

				uint32_t min_diff = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
				if (min_diff < best_diff)
					best_diff = min_diff;
			} // p
		}

		const uint32_t best_pat_index = best_diff & 0xFF;
		const uint32_t best_pat_bits = g_bc7_part2_bitmasks[best_pat_index];

		int total_r[2] = { }, total_g[2] = { }, total_b[2] = { }, total_c[2] = { };
		for (uint32_t i = 0; i < 16; i++)
		{
			const int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;
			const int subset = (best_pat_bits >> i) & 1;

			total_r[subset] += r; total_g[subset] += g; total_b[subset] += b;
			total_c[subset]++;
		}

		int mean_r[2], mean_g[2], mean_b[2];
		for (uint32_t s = 0; s < 2; s++)
		{
			const uint32_t t = total_c[s];
			const uint32_t h = (t >> 1);

			mean_r[s] = (total_r[s] + h) / t;
			mean_g[s] = (total_g[s] + h) / t;
			mean_b[s] = (total_b[s] + h) / t;
		}

		int icov[2][6] = { { }, { } };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int subset = (best_pat_bits >> i) & 1;

			int r = (int)pPixels[i].r - mean_r[subset];
			int g = (int)pPixels[i].g - mean_g[subset];
			int b = (int)pPixels[i].b - mean_b[subset];
			icov[subset][0] += r * r; icov[subset][1] += r * g; icov[subset][2] += r * b;
			icov[subset][3] += g * g; icov[subset][4] += g * b;
			icov[subset][5] += b * b;
		}

		int ar[2], ag[2], ab[2];

		// Slam to line SSE estimate is the same for both mode 1 and 3.
		float slam_to_line_sse_est = 0.0f;

		for (uint32_t s = 0; s < 2; s++)
		{
			int block_max_var = basisu::maximum(icov[s][0], icov[s][3], icov[s][5]);

			float cov[6];
			for (uint32_t i = 0; i < 6; i++)
				cov[i] = (float)icov[s][i];

			const float sc = 1.0f / ((float)block_max_var + .0000125f);
			const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

			const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
			const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
			const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

			slam_to_line_sse_est += estimate_slam_to_line_sse_3D(cov, alt_xr, alt_xg, alt_xb);

			int saxis_r = 306, saxis_g = 601, saxis_b = 117;

			float k = basisu::maximum(fabsf(alt_xr), fabsf(alt_xg), fabsf(alt_xb));
			if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
			{
				float m = 2048.0f / k;
				saxis_r = (int)(alt_xr * m);
				saxis_g = (int)(alt_xg * m);
				saxis_b = (int)(alt_xb * m);
			}

			ar[s] = (int)((uint32_t)saxis_r << 4U);
			ag[s] = (int)((uint32_t)saxis_g << 4U);
			ab[s] = (int)((uint32_t)saxis_b << 4U);
		} // s

		int low_dot[2] = { INT_MAX, INT_MAX };
		int high_dot[2] = { INT_MIN, INT_MIN };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int subset = (best_pat_bits >> i) & 1;
			const int saxis_r = ar[subset], saxis_g = ag[subset], saxis_b = ab[subset];

			int dot = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) + i;

			low_dot[subset] = basisu::minimum(low_dot[subset], dot);
			high_dot[subset] = basisu::maximum(high_dot[subset], dot);
		}

		int low_c[2] = { low_dot[0] & 15, low_dot[1] & 15 };
		int high_c[2] = { high_dot[0] & 15, high_dot[1] & 15 };

		int spans[4];
		spans[3] = 0;

		// Endpoint/weight quant error estimates for modes 1 and 3
		float quant_err_sse_est[2] = { };

		for (uint32_t subset = 0; subset < 2; subset++)
		{
			const uint32_t low_pixel = low_c[subset];
			const uint32_t high_pixel = high_c[subset];

			for (uint32_t c = 0; c < 3; c++)
				spans[c] = pPixels[high_pixel][c] - pPixels[low_pixel][c];

			// mode 1: 6-bit endpoints, unique pbits, 3 bit weights
			quant_err_sse_est[0] += analytical_quant_est_sse(64, 8, 3, spans, nullptr, (flags & cPackBC7FlagPBitOpt) ? UNIQUE_PBIT_DISCOUNT : 1.0f, total_c[subset]);

			// mode 3, 7-bit endpoints, shared pbits, 2-bit weights
			quant_err_sse_est[1] += analytical_quant_est_sse(128, 4, 3, spans, nullptr, (flags & cPackBC7FlagPBitOpt) ? SHARED_PBIT_DISCOUNT : 1.0f, total_c[subset]);

		} // subset

		const float total_mode1_est_sse = slam_to_line_sse_est + quant_err_sse_est[0];
		const float total_mode3_est_sse = slam_to_line_sse_est + quant_err_sse_est[1];

		if (total_mode1_est_sse < total_mode3_est_sse)
		{
			if (pFinal_sse_est)
				*pFinal_sse_est = total_mode1_est_sse;

			// Mode 1: Large span
			if (total_mode1_est_sse >= sse_est_to_beat)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_mode13_bailouts++;
#endif
				return false;
			}

			uint32_t lr[2], lg[2], lb[2];
			uint32_t hr[2], hg[2], hb[2];
			uint32_t pbits[2] = { 0, 0 };

			for (uint32_t s = 0; s < 2; s++)
			{
				const int lc = low_c[s], hc = high_c[s];

				if (flags & cPackBC7FlagPBitOpt)
				{
					const float q = 1.0f / 255.0f;
					float sxl[4] = { (float)pPixels[lc].r * q, (float)pPixels[lc].g * q, (float)pPixels[lc].b * q, 0 };
					float sxh[4] = { (float)pPixels[hc].r * q, (float)pPixels[hc].g * q, (float)pPixels[hc].b * q, 0 };

					color_rgba bestMinColor, bestMaxColor;
					uint32_t best_pbits[2];
					determine_shared_pbits(3, 6, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

					pbits[s] = best_pbits[0];
					lr[s] = bestMinColor.r, lg[s] = bestMinColor.g, lb[s] = bestMinColor.b;
					hr[s] = bestMaxColor.r, hg[s] = bestMaxColor.g, hb[s] = bestMaxColor.b;
				}
				else
				{
					int l = pPixels[lc].r + pPixels[lc].g + pPixels[lc].b;
					int h = pPixels[hc].r + pPixels[hc].g + pPixels[hc].b;

					if (basisu::maximum(l, h) >= 129 * 3)
						pbits[s] = 1;

					lr[s] = to_6(pPixels[lc].r, pbits[s]);
					lg[s] = to_6(pPixels[lc].g, pbits[s]);
					lb[s] = to_6(pPixels[lc].b, pbits[s]);

					hr[s] = to_6(pPixels[hc].r, pbits[s]);
					hg[s] = to_6(pPixels[hc].g, pbits[s]);
					hb[s] = to_6(pPixels[hc].b, pbits[s]);
				}
			} // s

			uint8_t cur_weights[16];
			eval_weights_mode1_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_bits);

			float z00[2] = { 0.0f }, z10[2] = { 0.0f }, z11[2] = { 0.0f };
			float q00_r[2] = { 0.0f };
			float q00_g[2] = { 0.0f };
			float q00_b[2] = { 0.0f };

			for (uint32_t i = 0; i < 16; i++)
			{
				const int subset = (best_pat_bits >> i) & 1;
				const uint32_t sel = cur_weights[i];
				assert(sel <= 7);

				z00[subset] += g_bc7_3bit_ls_tab[sel][0];
				z10[subset] += g_bc7_3bit_ls_tab[sel][1];
				z11[subset] += g_bc7_3bit_ls_tab[sel][2];

				const float w = g_bc7_3bit_ls_tab[sel][3];

				q00_r[subset] += w * (float)pPixels[i][0];
				q00_g[subset] += w * (float)pPixels[i][1];
				q00_b[subset] += w * (float)pPixels[i][2];
			} // i

			for (uint32_t s = 0; s < 2; s++)
			{
				float q10_r = (float)total_r[s] - q00_r[s];
				float q10_g = (float)total_g[s] - q00_g[s];
				float q10_b = (float)total_b[s] - q00_b[s];

				float z01 = z10[s];

				float det = z00[s] * z11[s] - z01 * z10[s];
				if (fabs(det) < 1e-8f)
					continue;

				det = 1.0f / det;

				float iz00, iz01, iz10, iz11;
				iz00 = z11[s] * det;
				iz01 = -z01 * det;
				iz10 = -z10[s] * det;
				iz11 = z00[s] * det;

				const float shr = iz00 * q00_r[s] + iz01 * q10_r;
				const float slr = iz10 * q00_r[s] + iz11 * q10_r;

				const float shg = iz00 * q00_g[s] + iz01 * q10_g;
				const float slg = iz10 * q00_g[s] + iz11 * q10_g;

				const float shb = iz00 * q00_b[s] + iz01 * q10_b;
				const float slb = iz10 * q00_b[s] + iz11 * q10_b;

				if (flags & cPackBC7FlagPBitOpt)
				{
					const float q = 1.0f / 255.0f;
					float sxl[4] = { basisu::clamp(slr * q, 0.0f, 1.0f), basisu::clamp(slg * q, 0.0f, 1.0f), basisu::clamp(slb * q, 0.0f, 1.0f), 0 };
					float sxh[4] = { basisu::clamp(shr * q, 0.0f, 1.0f), basisu::clamp(shg * q, 0.0f, 1.0f), basisu::clamp(shb * q, 0.0f, 1.0f), 0 };

					color_rgba bestMinColor, bestMaxColor;
					uint32_t best_pbits[2];
					determine_shared_pbits(3, 6, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

					pbits[s] = best_pbits[0];
					lr[s] = bestMinColor.r, lg[s] = bestMinColor.g, lb[s] = bestMinColor.b;
					hr[s] = bestMaxColor.r, hg[s] = bestMaxColor.g, hb[s] = bestMaxColor.b;
				}
				else
				{
					const float l = slr + slg + slb, h = shr + shg + shb;

					pbits[s] = (basisu::maximum(l, h) >= 129.0f * 3.0f);

					lr[s] = to_6_clamp(slr, pbits[s]);
					hr[s] = to_6_clamp(shr, pbits[s]);

					lg[s] = to_6_clamp(slg, pbits[s]);
					hg[s] = to_6_clamp(shg, pbits[s]);

					lb[s] = to_6_clamp(slb, pbits[s]);
					hb[s] = to_6_clamp(shb, pbits[s]);
				}

			} // s

			if (pActual_sse)
				*pActual_sse = eval_weights_mode1_rgb_sse(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_bits);
			else
				eval_weights_mode1_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_bits);

			encode_mode1_rgb_block(pBlock, best_pat_index,
				lr, lg, lb, hr, hg, hb, pbits[0], pbits[1], cur_weights);
		}
		else
		{
			// Mode 3: Small span
			if (pFinal_sse_est)
				*pFinal_sse_est = total_mode3_est_sse;

			if (total_mode3_est_sse >= sse_est_to_beat)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_mode13_bailouts++;
#endif
				return false;
			}

			uint32_t lr[2], lg[2], lb[2];
			uint32_t hr[2], hg[2], hb[2];
			uint32_t pbits[4];

			for (uint32_t s = 0; s < 2; s++)
			{
				const int lc = low_c[s];
				const int hc = high_c[s];

				if (flags & cPackBC7FlagPBitOpt)
				{
					const float q = 1.0f / 255.0f;
					float sxl[4] = { (float)pPixels[lc].r * q, (float)pPixels[lc].g * q, (float)pPixels[lc].b * q, 0 };
					float sxh[4] = { (float)pPixels[hc].r * q, (float)pPixels[hc].g * q, (float)pPixels[hc].b * q, 0 };

					color_rgba bestMinColor, bestMaxColor;
					uint32_t best_pbits[2];
					determine_unique_pbits(3, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

					pbits[s * 2 + 0] = best_pbits[0];
					pbits[s * 2 + 1] = best_pbits[1];
					lr[s] = bestMinColor.r, lg[s] = bestMinColor.g, lb[s] = bestMinColor.b;
					hr[s] = bestMaxColor.r, hg[s] = bestMaxColor.g, hb[s] = bestMaxColor.b;
				}
				else
				{
					const int l = pPixels[lc].r + pPixels[lc].g + pPixels[lc].b;
					const int l_pbit = (l >= 129);
					pbits[s * 2 + 0] = l_pbit;

					lr[s] = to_7(pPixels[lc].r, l_pbit);
					lg[s] = to_7(pPixels[lc].g, l_pbit);
					lb[s] = to_7(pPixels[lc].b, l_pbit);

					int h = pPixels[hc].r + pPixels[hc].g + pPixels[hc].b;
					const int h_pbit = (h >= 129);
					pbits[s * 2 + 1] = h_pbit;

					hr[s] = to_7(pPixels[hc].r, h_pbit);
					hg[s] = to_7(pPixels[hc].g, h_pbit);
					hb[s] = to_7(pPixels[hc].b, h_pbit);
				}
			} // s

			uint8_t cur_weights[16];
			eval_weights_mode3_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_bits);

			float z00[2] = { 0.0f }, z10[2] = { 0.0f }, z11[2] = { 0.0f };
			float q00_r[2] = { 0.0f };
			float q00_g[2] = { 0.0f };
			float q00_b[2] = { 0.0f };

			for (uint32_t i = 0; i < 16; i++)
			{
				const int subset = (best_pat_bits >> i) & 1;
				const uint32_t sel = cur_weights[i];
				assert(sel <= 3);

				z00[subset] += g_bc7_2bit_ls_tab[sel][0];
				z10[subset] += g_bc7_2bit_ls_tab[sel][1];
				z11[subset] += g_bc7_2bit_ls_tab[sel][2];

				const float w = g_bc7_2bit_ls_tab[sel][3];

				q00_r[subset] += w * (float)pPixels[i][0];
				q00_g[subset] += w * (float)pPixels[i][1];
				q00_b[subset] += w * (float)pPixels[i][2];
			} // i

			for (uint32_t s = 0; s < 2; s++)
			{
				float q10_r = (float)total_r[s] - q00_r[s];
				float q10_g = (float)total_g[s] - q00_g[s];
				float q10_b = (float)total_b[s] - q00_b[s];

				float z01 = z10[s];

				float det = z00[s] * z11[s] - z01 * z10[s];
				if (fabs(det) < 1e-8f)
					continue;

				det = 1.0f / det;

				float iz00, iz01, iz10, iz11;
				iz00 = z11[s] * det;
				iz01 = -z01 * det;
				iz10 = -z10[s] * det;
				iz11 = z00[s] * det;

				const float shr = iz00 * q00_r[s] + iz01 * q10_r;
				const float slr = iz10 * q00_r[s] + iz11 * q10_r;

				const float shg = iz00 * q00_g[s] + iz01 * q10_g;
				const float slg = iz10 * q00_g[s] + iz11 * q10_g;

				const float shb = iz00 * q00_b[s] + iz01 * q10_b;
				const float slb = iz10 * q00_b[s] + iz11 * q10_b;

				if (flags & cPackBC7FlagPBitOpt)
				{
					const float q = 1.0f / 255.0f;
					float sxl[4] = { basisu::clamp(slr * q, 0.0f, 1.0f), basisu::clamp(slg * q, 0.0f, 1.0f), basisu::clamp(slb * q, 0.0f, 1.0f), 0 };
					float sxh[4] = { basisu::clamp(shr * q, 0.0f, 1.0f), basisu::clamp(shg * q, 0.0f, 1.0f), basisu::clamp(shb * q, 0.0f, 1.0f), 0 };

					color_rgba bestMinColor, bestMaxColor;
					uint32_t best_pbits[2];
					determine_unique_pbits(3, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

					pbits[s * 2 + 0] = best_pbits[0];
					pbits[s * 2 + 1] = best_pbits[1];
					lr[s] = bestMinColor.r, lg[s] = bestMinColor.g, lb[s] = bestMinColor.b;
					hr[s] = bestMaxColor.r, hg[s] = bestMaxColor.g, hb[s] = bestMaxColor.b;
				}
				else
				{
					const float l = slr + slg + slb;
					const int l_pbit = (l >= 129.0f * 3.0f);
					pbits[s * 2 + 0] = l_pbit;

					lr[s] = to_7_clamp(slr, l_pbit);
					lg[s] = to_7_clamp(slg, l_pbit);
					lb[s] = to_7_clamp(slb, l_pbit);

					const float h = shr + shg + shb;
					const int h_pbit = (h >= 129.0f * 3.0f);
					pbits[s * 2 + 1] = h_pbit;

					hr[s] = to_7_clamp(shr, h_pbit);
					hg[s] = to_7_clamp(shg, h_pbit);
					hb[s] = to_7_clamp(shb, h_pbit);
				}

			} // s

			if (pActual_sse)
				*pActual_sse = eval_weights_mode3_rgb_sse(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_bits);
			else
				eval_weights_mode3_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_bits);

			encode_mode3_rgb_block(pBlock, best_pat_index,
				lr, lg, lb, hr, hg, hb, pbits, cur_weights);
		}

#ifdef _DEBUG
		if (pActual_sse)
		{
			const uint32_t expected_sse = calc_sse(pBlock, pPixels);
			assert(expected_sse == *pActual_sse);
		}
#endif

		return true;
	}

	inline int dist3(int lr, int lg, int lb, int hr, int hg, int hb)
	{
		return basisu::squarei(hr - lr) + basisu::squarei(hg - lg) + basisu::squarei(hb - lb);
	}

	bool determine_3subsets(uint8_t* pFinal_3subsets,
		const color_rgba* pPixels,
		float block_xr, float block_xg, float block_xb,
		int block_mean_r, int block_mean_g, int block_mean_b)
	{
		uint32_t subset_indices[16];
		int subset_means[2][3] = { };
		int subset_total[2] = { };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int rd = pPixels[i].r - block_mean_r;
			const int gd = pPixels[i].g - block_mean_g;
			const int bd = pPixels[i].b - block_mean_b;

			const uint32_t subset_index = ((float)rd * block_xr + (float)gd * block_xg + (float)bd * block_xb) > 0.0f;

			subset_indices[i] = subset_index;

			subset_means[subset_index][0] += pPixels[i].r;
			subset_means[subset_index][1] += pPixels[i].g;
			subset_means[subset_index][2] += pPixels[i].b;

			subset_total[subset_index]++;
		}

		for (uint32_t i = 0; i < 2; i++)
		{
			const uint32_t t = subset_total[i];
			if (!t)
				return false;

			subset_means[i][0] = (subset_means[i][0] + (t >> 1)) / t;
			subset_means[i][1] = (subset_means[i][1] + (t >> 1)) / t;
			subset_means[i][2] = (subset_means[i][2] + (t >> 1)) / t;
		}

		int subset_sses[2] = { };
		for (uint32_t i = 0; i < 16; i++)
		{
			const uint32_t subset_index = subset_indices[i];

			subset_sses[subset_index] += dist3(pPixels[i].r, pPixels[i].g, pPixels[i].b, subset_means[subset_index][0], subset_means[subset_index][1], subset_means[subset_index][2]);
		}

		const uint32_t subset_to_split = (subset_sses[1] > subset_sses[0]);
		if (subset_total[subset_to_split] < 2)
			return false;

		int lo_y = INT_MAX, hi_y = 0;
		for (uint32_t i = 0; i < 16; i++)
		{
			if (subset_indices[i] != subset_to_split)
				continue;

			int y = ((pPixels[i].r + pPixels[i].g + pPixels[i].b) << 4) + i;

			lo_y = basisu::minimum(lo_y, y);
			hi_y = basisu::maximum(hi_y, y);
		}

		const int lo_y_index = lo_y & 15, hi_y_index = hi_y & 15;
		if (lo_y_index == hi_y_index)
			return false;

		const int lr = pPixels[lo_y_index].r, lg = pPixels[lo_y_index].g, lb = pPixels[lo_y_index].b;
		const int hr = pPixels[hi_y_index].r, hg = pPixels[hi_y_index].g, hb = pPixels[hi_y_index].b;

		memset(pFinal_3subsets, 2, 16);

		for (uint32_t i = 0; i < 16; i++)
		{
			if (subset_indices[i] == subset_to_split)
			{
				const int dist0 = dist3(lr, lg, lb, pPixels[i].r, pPixels[i].g, pPixels[i].b);
				const int dist1 = dist3(hr, hg, hb, pPixels[i].r, pPixels[i].g, pPixels[i].b);

				pFinal_3subsets[i] = dist1 > dist0;
			}
		}

		return true;
	}
		
	static inline int pop16(uint32_t x)
	{
#if defined(_MSC_VER)
		return __popcnt16((unsigned short)x);
#else
		return __builtin_popcount(x & 0xFFFFu);
#endif
	}

	int pick_3subset_pat_index(const uint8_t* pDesired_subsets, uint32_t& best_pat_index_first16, uint32_t flags)
	{
		best_pat_index_first16 = 0;

		uint16_t M[3];
		memset(M, 0, sizeof(M));

		for (uint32_t i = 0; i < 16; i++)
		{
			uint32_t s = pDesired_subsets[i];
			M[s] |= (1 << i);
		}

		const int n0 = pop16(M[0]), n1 = pop16(M[1]), n2 = 16 - n0 - n1;

		int best_score = -1;
		int best_pat = 0;

		if (flags & cPackBC7FlagASTCCompatible)
		{
			for (int t = 0; t < (int)TOTAL_ASTC_BC7_COMMON_PARTITIONS3; t++)
			{
				const int p = g_astc_bc7_common_partitions3[t].m_bc7;

				uint16_t S0 = (uint16_t)(g_part3_bitmasks[p] & 0xFFFFu);
				uint16_t S1 = (uint16_t)(g_part3_bitmasks[p] >> 16);

				// Row sums for subsets 0 and 1 via 6 popcnts; derive subset 2 by subtraction
				int C00 = pop16(M[0] & S0), C01 = pop16(M[0] & S1), C02 = n0 - C00 - C01;
				int C10 = pop16(M[1] & S0), C11 = pop16(M[1] & S1), C12 = n1 - C10 - C11;
				int C20 = pop16(M[2] & S0), C21 = pop16(M[2] & S1), C22 = n2 - C20 - C21;

				int s0 = C00 + C11 + C22; // (0,1,2)
				int s1 = C00 + C12 + C21; // (0,2,1)
				int s2 = C01 + C10 + C22; // (1,0,2)
				int s3 = C01 + C12 + C20; // (1,2,0)
				int s4 = C02 + C10 + C21; // (2,0,1)
				int s5 = C02 + C11 + C20; // (2,1,0)

				// Argmax over 6
				int s = s0;
				if (s1 > s) { s = s1; }
				if (s2 > s) { s = s2; }
				if (s3 > s) { s = s3; }
				if (s4 > s) { s = s4; }
				if (s5 > s) { s = s5; }

				if (s > best_score)
				{
					best_score = s;
					best_pat = p;

					if (s == 16)
					{
						// perfect match so early out
						if (p <= 15)
							best_pat_index_first16 = best_pat;
						break;
					}
				}

				if (t == 6)
				{
					assert(best_pat < 16);

					// for mode 0
					best_pat_index_first16 = best_pat;
				}
			} // t
		}
		else
		{
			for (int p = 0; p < (int)MAX_PATTERNS3_TO_CHECK; ++p)
			{
				uint16_t S0 = (uint16_t)(g_part3_bitmasks[p] & 0xFFFFu);
				uint16_t S1 = (uint16_t)(g_part3_bitmasks[p] >> 16);

				// Row sums for subsets 0 and 1 via 6 popcnts; derive subset 2 by subtraction
				int C00 = pop16(M[0] & S0), C01 = pop16(M[0] & S1), C02 = n0 - C00 - C01;
				int C10 = pop16(M[1] & S0), C11 = pop16(M[1] & S1), C12 = n1 - C10 - C11;
				int C20 = pop16(M[2] & S0), C21 = pop16(M[2] & S1), C22 = n2 - C20 - C21;

				int s0 = C00 + C11 + C22; // (0,1,2)
				int s1 = C00 + C12 + C21; // (0,2,1)
				int s2 = C01 + C10 + C22; // (1,0,2)
				int s3 = C01 + C12 + C20; // (1,2,0)
				int s4 = C02 + C10 + C21; // (2,0,1)
				int s5 = C02 + C11 + C20; // (2,1,0)

				// Argmax over 6
				int s = s0;
				if (s1 > s) { s = s1; }
				if (s2 > s) { s = s2; }
				if (s3 > s) { s = s3; }
				if (s4 > s) { s = s4; }
				if (s5 > s) { s = s5; }

				if (s > best_score)
				{
					best_score = s;
					best_pat = p;

					if (s == 16)
					{
						// perfect match so early out
						if (p <= 15)
							best_pat_index_first16 = best_pat;
						break;
					}
				}

				if (p == 15)
				{
					// for mode 0
					best_pat_index_first16 = best_pat;
				}
			}
		}

		return best_pat;
	}

#if 0
	static const uint8_t s_perms3[6][3] = { {0,1,2}, {0,2,1}, {1,0,2}, {1,2,0}, {2,0,1}, {2,1,0} };

	int pick_3subset_pat_index_slow(const uint8_t* pDesired_subsets, uint32_t& best_pat_index_first16)
	{
		int best_pat = 0, best_dist = INT_MAX;

		for (uint32_t m = 0; m < 64; m++)
		{
			const uint8_t* pPat = &g_bc7_partition3[m * 16];

			for (uint32_t p = 0; p < 6; p++)
			{
				int trial_dist = 0;

				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t s = s_perms3[p][pDesired_subsets[i]];

					trial_dist += (s != pPat[i]);

				} // i

				if (trial_dist < best_dist)
				{
					best_dist = trial_dist;
					best_pat = m;
				}

			} // p

			if (m == 15)
				best_pat_index_first16 = best_pat;

		}  // m

		return best_pat;
	}
#endif

	// false if packing failed (not enough unique colors)
	bool pack_mode0_or_2_rgb(uint8_t* pBlock, const color_rgba* pPixels,
		float block_xr, float block_xg, float block_xb,
		int block_mean_r, int block_mean_g, int block_mean_b, float sse_est_to_beat, uint32_t flags,
		float* pFinal_sse_est = nullptr,
		uint32_t* pActual_sse = nullptr)
	{
		(void)flags;

#if BASISU_BC7F_PERF_STATS
		g_total_mode02_evals++;
#endif

		uint8_t desired_3subsets[16];
		if (!determine_3subsets(desired_3subsets, pPixels, block_xr, block_xg, block_xb, block_mean_r, block_mean_g, block_mean_b))
		{
#if BASISU_BC7F_PERF_STATS
			g_total_mode02_bailouts++;
#endif
			if (pFinal_sse_est)
				*pFinal_sse_est = 1e+9f;

			return false;
		}

		uint32_t best_pat_indices[2]; // mode 0 and 2
		best_pat_indices[1] = pick_3subset_pat_index(desired_3subsets, best_pat_indices[0], flags);

		assert((best_pat_indices[0] <= 15) && (best_pat_indices[1] <= 63));

		float total_quant_sse_mode[2] = { };
		float total_slam_to_line_sse_mode[2] = { };

		int mode_total_c[2][3] = { };
		int mode_low_c[2][3] = { }, mode_high_c[2][3] = { };
		int mode_total_r[2][3] = { }, mode_total_g[2][3] = { }, mode_total_b[2][3] = { };

		int spans[4] = { };

		for (uint32_t mode_iter = 0; mode_iter < 2; mode_iter++) // mode 0 vs. mode 2
		{
			if ((mode_iter) && (best_pat_indices[0] == best_pat_indices[1]))
			{
				for (uint32_t s = 0; s < 3; s++)
				{
					mode_total_c[1][s] = mode_total_c[0][s];

					mode_low_c[1][s] = mode_low_c[0][s];
					mode_high_c[1][s] = mode_high_c[0][s];

					mode_total_r[1][s] = mode_total_r[0][s];
					mode_total_g[1][s] = mode_total_g[0][s];
					mode_total_b[1][s] = mode_total_b[0][s];

					total_slam_to_line_sse_mode[1] = total_slam_to_line_sse_mode[0];

				} // subset
			}
			else
			{
				const uint32_t best_pat_index = best_pat_indices[mode_iter];
				const uint8_t* pBest_pat = &g_bc7_partition3[best_pat_index * 16];

				int* pTotal_r = &mode_total_r[mode_iter][0];
				int* pTotal_g = &mode_total_g[mode_iter][0];
				int* pTotal_b = &mode_total_b[mode_iter][0];

				int* pTotal_c = mode_total_c[mode_iter];

				for (uint32_t i = 0; i < 16; i++)
				{
					const int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;
					const int subset = pBest_pat[i];

					pTotal_r[subset] += r; pTotal_g[subset] += g; pTotal_b[subset] += b;
					pTotal_c[subset]++;
				}

				int mean_r[3], mean_g[3], mean_b[3];
				for (uint32_t s = 0; s < 3; s++)
				{
					const uint32_t t = pTotal_c[s];
					const uint32_t h = (t >> 1);

					mean_r[s] = (pTotal_r[s] + h) / t;
					mean_g[s] = (pTotal_g[s] + h) / t;
					mean_b[s] = (pTotal_b[s] + h) / t;
				}

				int icov[3][6] = { };

				for (uint32_t i = 0; i < 16; i++)
				{
					const int subset = pBest_pat[i];

					int r = (int)pPixels[i].r - mean_r[subset];
					int g = (int)pPixels[i].g - mean_g[subset];
					int b = (int)pPixels[i].b - mean_b[subset];
					icov[subset][0] += r * r; icov[subset][1] += r * g; icov[subset][2] += r * b;
					icov[subset][3] += g * g; icov[subset][4] += g * b;
					icov[subset][5] += b * b;
				}

				int ar[3], ag[3], ab[3];

				float total_slam_to_line_sse = 0.0f;

				for (uint32_t s = 0; s < 3; s++)
				{
					int block_max_var = basisu::maximum(icov[s][0], icov[s][3], icov[s][5]);

					float cov[6];
					for (uint32_t i = 0; i < 6; i++)
						cov[i] = (float)icov[s][i];

					const float sc = 1.0f / ((float)block_max_var + .0000125f);
					const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

					const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
					const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
					const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

					total_slam_to_line_sse += estimate_slam_to_line_sse_3D(cov, alt_xr, alt_xg, alt_xb);

					int saxis_r = 306, saxis_g = 601, saxis_b = 117;

					float k = basisu::maximum(fabsf(alt_xr), fabsf(alt_xg), fabsf(alt_xb));
					if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
					{
						float m = 2048.0f / k;
						saxis_r = (int)(alt_xr * m);
						saxis_g = (int)(alt_xg * m);
						saxis_b = (int)(alt_xb * m);
					}

					ar[s] = (int)((uint32_t)saxis_r << 4U);
					ag[s] = (int)((uint32_t)saxis_g << 4U);
					ab[s] = (int)((uint32_t)saxis_b << 4U);
				} // s

				total_slam_to_line_sse_mode[mode_iter] = total_slam_to_line_sse;

				int low_dot[3] = { INT_MAX, INT_MAX, INT_MAX };
				int high_dot[3] = { INT_MIN, INT_MIN, INT_MIN };

				for (uint32_t i = 0; i < 16; i++)
				{
					const int subset = pBest_pat[i];
					const int saxis_r = ar[subset], saxis_g = ag[subset], saxis_b = ab[subset];

					int dot = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) + i;

					low_dot[subset] = basisu::minimum(low_dot[subset], dot);
					high_dot[subset] = basisu::maximum(high_dot[subset], dot);
				}

				for (uint32_t subset = 0; subset < 3; subset++)
				{
					mode_low_c[mode_iter][subset] = low_dot[subset] & 15;
					mode_high_c[mode_iter][subset] = high_dot[subset] & 15;
				} // subset

			} // if ((mode_iter) && (best_pat_indices[0] == best_pat_indices[1]))

			for (uint32_t subset = 0; subset < 3; subset++)
			{
				const uint32_t low_pixel = mode_low_c[mode_iter][subset];
				const uint32_t high_pixel = mode_high_c[mode_iter][subset];

				for (uint32_t c = 0; c < 3; c++)
					spans[c] = pPixels[high_pixel][c] - pPixels[low_pixel][c];

				float subset_sse;
				if (mode_iter == 0)
				{
					// mode 0: 4-bit endpoints, unique p-bits, 3-bit weights, slight p-bit endpoint scale factor
					subset_sse = analytical_quant_est_sse(16, 8, 3, spans, nullptr, UNIQUE_PBIT_DISCOUNT, mode_total_c[mode_iter][subset]);
				}
				else
				{
					// mode 2: 5-bit endpoints, no p-bits, 2-bit weights, no endpoint scale factor
					subset_sse = analytical_quant_est_sse(32, 4, 3, spans, nullptr, 1.0f, mode_total_c[mode_iter][subset]);
				}

				total_quant_sse_mode[mode_iter] += subset_sse;
			} // subset

		} // mode_iter

		const float total_sse_est_mode0 = total_quant_sse_mode[0] + total_slam_to_line_sse_mode[0];
		const float total_sse_est_mode2 = total_quant_sse_mode[1] + total_slam_to_line_sse_mode[1];

		if (total_sse_est_mode0 < total_sse_est_mode2)
		{
			if (pFinal_sse_est)
				*pFinal_sse_est = total_sse_est_mode0;

			// Use mode 0 (high span)
			if (total_sse_est_mode0 >= sse_est_to_beat)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_mode02_bailouts++;
#endif
				return false;
			}

			const uint32_t best_pat_index = best_pat_indices[0];
			const uint8_t* pBest_pat = &g_bc7_partition3[best_pat_index * 16];

			const int* pLow_c = &mode_low_c[0][0];
			const int* pHigh_c = &mode_high_c[0][0];

			const int* pTotal_r = &mode_total_r[0][0];
			const int* pTotal_g = &mode_total_g[0][0];
			const int* pTotal_b = &mode_total_b[0][0];

			float xl[3][4], xh[3][4];

			for (uint32_t s = 0; s < 3; s++)
			{
				const int lc = pLow_c[s];
				const int hc = pHigh_c[s];

				xl[s][0] = (float)pPixels[lc].r * (1.0f / 255.0f);
				xl[s][1] = (float)pPixels[lc].g * (1.0f / 255.0f);
				xl[s][2] = (float)pPixels[lc].b * (1.0f / 255.0f);
				xl[s][3] = 0.0f;

				xh[s][0] = (float)pPixels[hc].r * (1.0f / 255.0f);
				xh[s][1] = (float)pPixels[hc].g * (1.0f / 255.0f);
				xh[s][2] = (float)pPixels[hc].b * (1.0f / 255.0f);
				xh[s][3] = 0.0f;
			} // s

			uint32_t lr[3], lg[3], lb[3], hr[3], hg[3], hb[3], pbits[6];

			for (uint32_t s = 0; s < 3; s++)
			{
				color_rgba el, eh;
				determine_unique_pbits(3, 4, xl[s], xh[s], el, eh, &pbits[s << 1]);

				lr[s] = el[0]; lg[s] = el[1]; lb[s] = el[2];
				hr[s] = eh[0]; hg[s] = eh[1]; hb[s] = eh[2];

			} // s

			uint8_t cur_weights[16];
			eval_weights_mode0_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_index);

			float z00[3] = { 0.0f }, z10[3] = { 0.0f }, z11[3] = { 0.0f };
			float q00_r[3] = { 0.0f };
			float q00_g[3] = { 0.0f };
			float q00_b[3] = { 0.0f };

			for (uint32_t i = 0; i < 16; i++)
			{
				const int subset = pBest_pat[i];
				const uint32_t sel = cur_weights[i];
				assert(sel <= 7);

				z00[subset] += g_bc7_3bit_ls_tab[sel][0];
				z10[subset] += g_bc7_3bit_ls_tab[sel][1];
				z11[subset] += g_bc7_3bit_ls_tab[sel][2];

				const float w = g_bc7_3bit_ls_tab[sel][3];

				q00_r[subset] += w * (float)pPixels[i][0];
				q00_g[subset] += w * (float)pPixels[i][1];
				q00_b[subset] += w * (float)pPixels[i][2];
			} // i

			for (uint32_t s = 0; s < 3; s++)
			{
				float q10_r = (float)pTotal_r[s] - q00_r[s];
				float q10_g = (float)pTotal_g[s] - q00_g[s];
				float q10_b = (float)pTotal_b[s] - q00_b[s];

				float z01 = z10[s];

				float det = z00[s] * z11[s] - z01 * z10[s];
				if (fabs(det) < 1e-8f)
					continue;

				det = 1.0f / det;

				float iz00, iz01, iz10, iz11;
				iz00 = z11[s] * det;
				iz01 = -z01 * det;
				iz10 = -z10[s] * det;
				iz11 = z00[s] * det;

				const float q = 1.0f / 255.0f;

				xl[s][0] = basisu::clamp(q * (iz10 * q00_r[s] + iz11 * q10_r), 0.0f, 1.0f);
				xh[s][0] = basisu::clamp(q * (iz00 * q00_r[s] + iz01 * q10_r), 0.0f, 1.0f);

				xl[s][1] = basisu::clamp(q * (iz10 * q00_g[s] + iz11 * q10_g), 0.0f, 1.0f);
				xh[s][1] = basisu::clamp(q * (iz00 * q00_g[s] + iz01 * q10_g), 0.0f, 1.0f);

				xl[s][2] = basisu::clamp(q * (iz10 * q00_b[s] + iz11 * q10_b), 0.0f, 1.0f);
				xh[s][2] = basisu::clamp(q * (iz00 * q00_b[s] + iz01 * q10_b), 0.0f, 1.0f);
			} // s

			for (uint32_t s = 0; s < 3; s++)
			{
				color_rgba el, eh;
				determine_unique_pbits(3, 4, xl[s], xh[s], el, eh, &pbits[s << 1]); // fills in both pbit entries

				lr[s] = el[0]; lg[s] = el[1]; lb[s] = el[2];
				hr[s] = eh[0]; hg[s] = eh[1]; hb[s] = eh[2];

			} // s

			if (pActual_sse)
				*pActual_sse = eval_weights_mode0_rgb_sse(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_index);
			else
				eval_weights_mode0_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, pbits, best_pat_index);

			encode_mode0_rgb_block(pBlock, best_pat_index, lr, lg, lb, hr, hg, hb, pbits, cur_weights);
		}
		else
		{
			if (pFinal_sse_est)
				*pFinal_sse_est = total_sse_est_mode2;

			// Use mode 2 (low span)
			if (total_sse_est_mode2 >= sse_est_to_beat)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_mode02_bailouts++;
#endif
				return false;
			}

			const uint32_t best_pat_index = best_pat_indices[1];
			const uint8_t* pBest_pat = &g_bc7_partition3[best_pat_index * 16];

			const int* pLow_c = &mode_low_c[1][0];
			const int* pHigh_c = &mode_high_c[1][0];

			const int* pTotal_r = &mode_total_r[1][0];
			const int* pTotal_g = &mode_total_g[1][0];
			const int* pTotal_b = &mode_total_b[1][0];

			uint32_t lr[3], lg[3], lb[3];
			uint32_t hr[3], hg[3], hb[3];

			for (uint32_t s = 0; s < 3; s++)
			{
				const int lc = pLow_c[s];
				const int hc = pHigh_c[s];

				lr[s] = to_5(pPixels[lc].r);
				lg[s] = to_5(pPixels[lc].g);
				lb[s] = to_5(pPixels[lc].b);

				hr[s] = to_5(pPixels[hc].r);
				hg[s] = to_5(pPixels[hc].g);
				hb[s] = to_5(pPixels[hc].b);
			}

			uint8_t cur_weights[16];
			eval_weights_mode2_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, best_pat_index);

			float z00[3] = { 0.0f }, z10[3] = { 0.0f }, z11[3] = { 0.0f };
			float q00_r[3] = { 0.0f };
			float q00_g[3] = { 0.0f };
			float q00_b[3] = { 0.0f };

			for (uint32_t i = 0; i < 16; i++)
			{
				const int subset = pBest_pat[i];
				const uint32_t sel = cur_weights[i];
				assert(sel <= 3);

				z00[subset] += g_bc7_2bit_ls_tab[sel][0];
				z10[subset] += g_bc7_2bit_ls_tab[sel][1];
				z11[subset] += g_bc7_2bit_ls_tab[sel][2];

				const float w = g_bc7_2bit_ls_tab[sel][3];

				q00_r[subset] += w * (float)pPixels[i][0];
				q00_g[subset] += w * (float)pPixels[i][1];
				q00_b[subset] += w * (float)pPixels[i][2];
			} // i

			for (uint32_t s = 0; s < 3; s++)
			{
				float q10_r = (float)pTotal_r[s] - q00_r[s];
				float q10_g = (float)pTotal_g[s] - q00_g[s];
				float q10_b = (float)pTotal_b[s] - q00_b[s];

				float z01 = z10[s];

				float det = z00[s] * z11[s] - z01 * z10[s];
				if (fabs(det) < 1e-8f)
					continue;

				det = 1.0f / det;

				float iz00, iz01, iz10, iz11;
				iz00 = z11[s] * det;
				iz01 = -z01 * det;
				iz10 = -z10[s] * det;
				iz11 = z00[s] * det;

				hr[s] = to_5_clamp(iz00 * q00_r[s] + iz01 * q10_r);
				lr[s] = to_5_clamp(iz10 * q00_r[s] + iz11 * q10_r);

				hg[s] = to_5_clamp(iz00 * q00_g[s] + iz01 * q10_g);
				lg[s] = to_5_clamp(iz10 * q00_g[s] + iz11 * q10_g);

				hb[s] = to_5_clamp(iz00 * q00_b[s] + iz01 * q10_b);
				lb[s] = to_5_clamp(iz10 * q00_b[s] + iz11 * q10_b);
			} // s

			if (pActual_sse)
				*pActual_sse = eval_weights_mode2_rgb_sse(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, best_pat_index);
			else
				eval_weights_mode2_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, best_pat_index);

			encode_mode2_rgb_block(pBlock, best_pat_index,
				lr, lg, lb, hr, hg, hb, cur_weights);
		}

#ifdef _DEBUG
		if (pActual_sse)
		{
			const uint32_t expected_sse = calc_sse(pBlock, pPixels);
			assert(expected_sse == *pActual_sse);
		}
#endif

		return true;
	}

	bool pack_mode4_or_5(uint8_t* pBlock, const color_rgba* pOrig_pixels, uint32_t dp_chan_index, float sse_est_to_beat, uint32_t flags,
		float* pFinal_sse_est = nullptr,
		uint32_t* pActual_sse = nullptr)
	{
		(void)flags;

#if BASISU_BC7F_PERF_STATS
		g_total_mode45_evals++;
#endif

		color_rgba pixels[16];
		const color_rgba* pPixels = pOrig_pixels;

		if (dp_chan_index != 3)
		{
			memcpy(pixels, pOrig_pixels, sizeof(color_rgba) * 16);
			pPixels = pixels;

			for (uint32_t i = 0; i < 16; i++)
			{
				const uint8_t c = pixels[i][dp_chan_index];
				pixels[i][dp_chan_index] = pixels[i][3];
				pixels[i][3] = c;
			}
		}

		int total_r = 0, total_g = 0, total_b = 0, total_a = 0;

		int min_r = 255, min_g = 255, min_b = 255, min_a = 255;
		int max_r = 0, max_g = 0, max_b = 0, max_a = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b, a = pPixels[i].a;

			total_r += r; total_g += g; total_b += b; total_a += a;

			min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b); min_a = basisu::minimum(min_a, a);
			max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b); max_a = basisu::maximum(max_a, a);
		}

		int mean_r = (total_r + 8) >> 4, mean_g = (total_g + 8) >> 4, mean_b = (total_b + 8) >> 4;

		// covar rows are:
		// 0, 1, 2
		// 1, 3, 4
		// 2, 4, 5
		int icov[6] = { 0, 0, 0, 0, 0, 0 };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int r = (int)pPixels[i].r - mean_r;
			const int g = (int)pPixels[i].g - mean_g;
			const int b = (int)pPixels[i].b - mean_b;
			icov[0] += r * r; icov[1] += r * g; icov[2] += r * b;
			icov[3] += g * g; icov[4] += g * b;
			icov[5] += b * b;
		}

		float cov3[6];
		for (uint32_t i = 0; i < 6; i++)
			cov3[i] = (float)icov[i];

		const int block_max_var3 = basisu::maximum(icov[0], icov[3], icov[5]); // not divided by 16, i.e. scaled by 16

		const float sc3 = block_max_var3 ? (1.0f / (float)block_max_var3) : 0;
		const float wx3 = sc3 * cov3[0], wy3 = sc3 * cov3[3], wz3 = sc3 * cov3[5];

		const float alt_xr = cov3[0] * wx3 + cov3[1] * wy3 + cov3[2] * wz3;
		const float alt_xg = cov3[1] * wx3 + cov3[3] * wy3 + cov3[4] * wz3;
		const float alt_xb = cov3[2] * wx3 + cov3[4] * wy3 + cov3[5] * wz3;

		// Same for mode 4/5
		const float rgb_slam_to_line_sse_est = estimate_slam_to_line_sse_3D(cov3, alt_xr, alt_xg, alt_xb);

		int saxis_r = 306, saxis_g = 601, saxis_b = 117;

		float k = basisu::maximum(fabsf(alt_xr), fabsf(alt_xg), fabsf(alt_xb));
		if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
		{
			float m = 2048.0f / k;
			saxis_r = (int)(alt_xr * m);
			saxis_g = (int)(alt_xg * m);
			saxis_b = (int)(alt_xb * m);
		}

		saxis_r = (int)((uint32_t)saxis_r << 4U);
		saxis_g = (int)((uint32_t)saxis_g << 4U);
		saxis_b = (int)((uint32_t)saxis_b << 4U);

		int low_dot = INT_MAX, high_dot = INT_MIN;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			int dot0 = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) + i;
			int dot1 = (pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b) + i + 1;
			int dot2 = (pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b) + i + 2;
			int dot3 = (pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b) + i + 3;

			int min_d01 = basisu::minimum(dot0, dot1);
			int max_d01 = basisu::maximum(dot0, dot1);

			int min_d23 = basisu::minimum(dot2, dot3);
			int max_d23 = basisu::maximum(dot2, dot3);

			int min_d = basisu::minimum(min_d01, min_d23);
			int max_d = basisu::maximum(max_d01, max_d23);

			low_dot = basisu::minimum(low_dot, min_d);
			high_dot = basisu::maximum(high_dot, max_d);
		}

		const int low_c = low_dot & 15;
		const int high_c = high_dot & 15;

		const int rgb_spans[4] = { pPixels[high_c][0] - pPixels[low_c][0], pPixels[high_c][1] - pPixels[low_c][1], pPixels[high_c][2] - pPixels[low_c][2], 0 };
		const int a_span = max_a - min_a;

		const float SECOND_PLANE_SPAN_WEIGHT = (dp_chan_index == 3) ? 1.0f : 1.0f;

		const float mode_4_rgb_3bit_quant_sse_est = analytical_quant_est_sse(32, 8, 3, rgb_spans, nullptr, 1.0f, 16); // mode 4 rgb: 5-bit endpoints, using 3-bit weights for RGB
		const float mode_4_a_2bit_quant_sse_est = analytical_quant_est_sse(64, 4, a_span, SECOND_PLANE_SPAN_WEIGHT, 1.0f, 16); // mode 4 a: 6-bit endpoints, using 2-bit weights for RGB

		const float mode_4_rgb_2bit_quant_sse_est = analytical_quant_est_sse(32, 4, 3, rgb_spans, nullptr, 1.0f, 16); // mode 4 rgb: 5-bit endpoints, using 2-bit weights for RGB
		const float mode_4_a_3bit_quant_sse_est = analytical_quant_est_sse(64, 8, a_span, SECOND_PLANE_SPAN_WEIGHT, 1.0f, 16); // mode 4 a: 6-bit endpoints, using 3-bit weights for RGB

		const float total_mode_4_rgb3_a2_sse_est = rgb_slam_to_line_sse_est + mode_4_rgb_3bit_quant_sse_est + mode_4_a_2bit_quant_sse_est;
		const float total_mode_4_rgb2_a3_sse_est = rgb_slam_to_line_sse_est + mode_4_rgb_2bit_quant_sse_est + mode_4_a_3bit_quant_sse_est;

		const float mode_5_rgb_quant_sse_est = analytical_quant_est_sse(128, 4, 3, rgb_spans, nullptr, 1.0f, 16); // mode 5 rgb: 7-bit endpoints, using 2-bit weights for RGB
		const float mode_5_a_quant_sse_est = analytical_quant_est_sse(256, 4, a_span, SECOND_PLANE_SPAN_WEIGHT, 1.0f, 16); // mode 5 a: 8-bit endpoints, using 2-bit weights for RGB
		const float total_mode_5_rgba_sse_est = rgb_slam_to_line_sse_est + mode_5_rgb_quant_sse_est + mode_5_a_quant_sse_est;

		if (total_mode_5_rgba_sse_est < basisu::minimum(total_mode_4_rgb3_a2_sse_est, total_mode_4_rgb2_a3_sse_est))
		{
			if (pFinal_sse_est)
				*pFinal_sse_est = total_mode_5_rgba_sse_est;

			// Mode 5 - low RGB/A span
			if (total_mode_5_rgba_sse_est >= sse_est_to_beat)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_mode45_bailouts++;
#endif
				return false;
			}

			int lr = to_7(pPixels[low_c].r), lg = to_7(pPixels[low_c].g), lb = to_7(pPixels[low_c].b), la = min_a;
			int hr = to_7(pPixels[high_c].r), hg = to_7(pPixels[high_c].g), hb = to_7(pPixels[high_c].b), ha = max_a;

			uint8_t cur_weights0[16]; // rgb 2-bits
			if (pActual_sse)
				*pActual_sse = eval_weights_mode5_2bit_rgb_sse(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
			else
				eval_weights_mode5_2bit_rgb(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);

			vec4F xl, xh;
			bool res = compute_least_squares_endpoints_3D(
				16, cur_weights0, 4,
				g_bc7_2bit_ls_tab,
				xl, xh,
				pPixels,
				(float)total_r, (float)total_g, (float)total_b);

			if (res)
			{
				lr = fast_roundf_int(xl[0] * (127.0f / 255.0f));
				lg = fast_roundf_int(xl[1] * (127.0f / 255.0f));
				lb = fast_roundf_int(xl[2] * (127.0f / 255.0f));

				hr = fast_roundf_int(xh[0] * (127.0f / 255.0f));
				hg = fast_roundf_int(xh[1] * (127.0f / 255.0f));
				hb = fast_roundf_int(xh[2] * (127.0f / 255.0f));

				if (pActual_sse)
					*pActual_sse = eval_weights_mode5_2bit_rgb_sse(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
				else
					eval_weights_mode5_2bit_rgb(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
			}

			uint8_t cur_weights1[16]; // alpha 2-bits
			uint32_t a_sse = 0;
			if (pActual_sse)
				a_sse = eval_weights_mode5_2bit_a_sse(pPixels, cur_weights1, la, ha);
			else
				eval_weights_mode5_2bit_a(pPixels, cur_weights1, la, ha);

			float nal, nah;
			if (compute_least_squares_endpoints_1D(
				16, cur_weights1, 4,
				g_bc7_2bit_ls_tab,
				nal, nah,
				pPixels, 3,
				(float)total_a))
			{
				la = fast_roundf_int(nal);
				ha = fast_roundf_int(nah);

				if (pActual_sse)
					a_sse = eval_weights_mode5_2bit_a_sse(pPixels, cur_weights1, la, ha);
				else
					eval_weights_mode5_2bit_a(pPixels, cur_weights1, la, ha);
			}

			if (pActual_sse)
				*pActual_sse += a_sse;

			encode_mode5_rgba_block(pBlock,
				lr, lg, lb, la,
				hr, hg, hb, ha,
				cur_weights0, cur_weights1, (dp_chan_index + 1) & 3);
		}
		else if (total_mode_4_rgb3_a2_sse_est < total_mode_4_rgb2_a3_sse_est)
		{
			if (pFinal_sse_est)
				*pFinal_sse_est = total_mode_4_rgb3_a2_sse_est;

			// mode 4, rgb 3-bits, alpha 2-bits - high span RGB, low span in A, index bit=1
			if (total_mode_4_rgb3_a2_sse_est >= sse_est_to_beat)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_mode45_bailouts++;
#endif
				return false;
			}

			int lr = to_5(pPixels[low_c].r), lg = to_5(pPixels[low_c].g), lb = to_5(pPixels[low_c].b), la = to_6(min_a);
			int hr = to_5(pPixels[high_c].r), hg = to_5(pPixels[high_c].g), hb = to_5(pPixels[high_c].b), ha = to_6(max_a);

			uint8_t cur_weights0[16]; // rgb 3-bits
			if (pActual_sse)
				*pActual_sse = eval_weights_mode4_3bit_rgb_sse(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
			else
				eval_weights_mode4_3bit_rgb(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);

			vec4F xl, xh;
			bool res = compute_least_squares_endpoints_3D(
				16, cur_weights0, 8,
				g_bc7_3bit_ls_tab,
				xl, xh,
				pPixels,
				(float)total_r, (float)total_g, (float)total_b);

			if (res)
			{
				lr = fast_roundf_int(xl[0] * (31.0f / 255.0f));
				lg = fast_roundf_int(xl[1] * (31.0f / 255.0f));
				lb = fast_roundf_int(xl[2] * (31.0f / 255.0f));

				hr = fast_roundf_int(xh[0] * (31.0f / 255.0f));
				hg = fast_roundf_int(xh[1] * (31.0f / 255.0f));
				hb = fast_roundf_int(xh[2] * (31.0f / 255.0f));

				if (pActual_sse)
					*pActual_sse = eval_weights_mode4_3bit_rgb_sse(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
				else
					eval_weights_mode4_3bit_rgb(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
			}

			uint8_t cur_weights1[16]; // alpha 2-bits

			uint32_t a_sse = 0;
			if (pActual_sse)
				a_sse = eval_weights_mode4_2bit_a_sse(pPixels, cur_weights1, la, ha);
			else
				eval_weights_mode4_2bit_a(pPixels, cur_weights1, la, ha);

			float nal, nah;
			if (compute_least_squares_endpoints_1D(
				16, cur_weights1, 4,
				g_bc7_2bit_ls_tab,
				nal, nah,
				pPixels, 3,
				(float)total_a))
			{
				la = fast_roundf_int(nal * (63.0f / 255.0f));
				ha = fast_roundf_int(nah * (63.0f / 255.0f));

				if (pActual_sse)
					a_sse = eval_weights_mode4_2bit_a_sse(pPixels, cur_weights1, la, ha);
				else
					eval_weights_mode4_2bit_a(pPixels, cur_weights1, la, ha);
			}

			if (pActual_sse)
				*pActual_sse += a_sse;

			encode_mode4_rgba_block(pBlock,
				lr, lg, lb, la,
				hr, hg, hb, ha,
				cur_weights0, cur_weights1, (dp_chan_index + 1) & 3, 1);
		}
		else
		{
			if (pFinal_sse_est)
				*pFinal_sse_est = total_mode_4_rgb2_a3_sse_est;

			// mode 4, rgb 2-bits, alpha 3-bits - low span RGB, high span in A, index bit=0
			if (total_mode_4_rgb2_a3_sse_est >= sse_est_to_beat)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_mode45_bailouts++;
#endif
				return false;
			}

			int lr = to_5(pPixels[low_c].r), lg = to_5(pPixels[low_c].g), lb = to_5(pPixels[low_c].b), la = to_6(min_a);
			int hr = to_5(pPixels[high_c].r), hg = to_5(pPixels[high_c].g), hb = to_5(pPixels[high_c].b), ha = to_6(max_a);

			uint8_t cur_weights0[16]; // rgb 2-bits
			if (pActual_sse)
				*pActual_sse = eval_weights_mode4_2bit_rgb_sse(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
			else
				eval_weights_mode4_2bit_rgb(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);

			vec4F xl, xh;
			bool res = compute_least_squares_endpoints_3D(
				16, cur_weights0, 4,
				g_bc7_2bit_ls_tab,
				xl, xh,
				pPixels,
				(float)total_r, (float)total_g, (float)total_b);

			if (res)
			{
				lr = fast_roundf_int(xl[0] * (31.0f / 255.0f));
				lg = fast_roundf_int(xl[1] * (31.0f / 255.0f));
				lb = fast_roundf_int(xl[2] * (31.0f / 255.0f));

				hr = fast_roundf_int(xh[0] * (31.0f / 255.0f));
				hg = fast_roundf_int(xh[1] * (31.0f / 255.0f));
				hb = fast_roundf_int(xh[2] * (31.0f / 255.0f));

				if (pActual_sse)
					*pActual_sse = eval_weights_mode4_2bit_rgb_sse(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
				else
					eval_weights_mode4_2bit_rgb(pPixels, cur_weights0, lr, lg, lb, hr, hg, hb);
			}

			uint8_t cur_weights1[16]; // alpha 2-bits
			uint32_t a_sse = 0;
			if (pActual_sse)
				a_sse = eval_weights_mode4_3bit_a_sse(pPixels, cur_weights1, la, ha);
			else
				eval_weights_mode4_3bit_a(pPixels, cur_weights1, la, ha);

			float nal, nah;
			if (compute_least_squares_endpoints_1D(
				16, cur_weights1, 8,
				g_bc7_3bit_ls_tab,
				nal, nah,
				pPixels, 3,
				(float)total_a))
			{
				la = fast_roundf_int(nal * (63.0f / 255.0f));
				ha = fast_roundf_int(nah * (63.0f / 255.0f));

				if (pActual_sse)
					a_sse = eval_weights_mode4_3bit_a_sse(pPixels, cur_weights1, la, ha);
				else
					eval_weights_mode4_3bit_a(pPixels, cur_weights1, la, ha);
			}

			if (pActual_sse)
				*pActual_sse += a_sse;

			encode_mode4_rgba_block(pBlock,
				lr, lg, lb, la,
				hr, hg, hb, ha,
				cur_weights0, cur_weights1, (dp_chan_index + 1) & 3, 0);
		}

#ifdef _DEBUG
		if (pActual_sse)
		{
			const uint32_t expected_sse = calc_sse(pBlock, pOrig_pixels);
			assert(expected_sse == *pActual_sse);
		}
#endif

		return true;
	}

	bool pack_mode7_rgba(uint8_t* pBlock, const color_rgba* pPixels,
		float block_xr, float block_xg, float block_xb, float block_xa,
		int block_mean_r, int block_mean_g, int block_mean_b, int block_mean_a,
		float sse_est_to_beat, uint32_t flags,
		float* pFinal_sse_est = nullptr,
		uint32_t* pActual_sse = nullptr)
	{
#if BASISU_BC7F_PERF_STATS
		g_total_mode7_evals++;
#endif

		uint32_t desired_pat_bits = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			const float r = (float)(pPixels[i].r - block_mean_r);
			const float g = (float)(pPixels[i].g - block_mean_g);
			const float b = (float)(pPixels[i].b - block_mean_b);
			const float a = (float)(pPixels[i].a - block_mean_a);

			const uint32_t subset = (r * block_xr + g * block_xg + b * block_xb + a * block_xa) > 0.0f;

			desired_pat_bits |= (subset << i);
		}

		uint32_t best_diff = UINT32_MAX;
		if (flags & cPackBC7FlagASTCCompatible)
		{
			// We're actually encoding to ASTC 4x4, so we can only check the 2-subset patterns in common between BC7 and ASTC (the UASTC LDR 4x4 patterns).
			for (uint32_t c = 0; c < TOTAL_ASTC_BC7_COMMON_PARTITIONS2; c++)
			{
				const uint32_t p = g_astc_bc7_common_partitions2[c].m_bc7;

				const uint32_t bc6h_pat_bits = g_bc7_part2_bitmasks[p];

				int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
				int diff_inv = 16 - diff;

				uint32_t min_diff = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
				if (min_diff < best_diff)
					best_diff = min_diff;
			} // c
		}
		else
		{
			for (uint32_t p = 0; p < MAX_PATTERNS2_TO_CHECK; p++)
			{
				const uint32_t bc6h_pat_bits = g_bc7_part2_bitmasks[p];

				int diff = popcount32(bc6h_pat_bits ^ desired_pat_bits);
				int diff_inv = 16 - diff;

				uint32_t min_diff = (basisu::minimum<int>(diff, diff_inv) << 8) | p;
				if (min_diff < best_diff)
					best_diff = min_diff;
			} // p
		}

		const uint32_t best_pat_index = best_diff & 0xFF;
		const uint32_t best_pat_bits = g_bc7_part2_bitmasks[best_pat_index];

		int total_r[2] = { }, total_g[2] = { }, total_b[2] = { }, total_a[2] = { }, total_c[2] = { };
		for (uint32_t i = 0; i < 16; i++)
		{
			const int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b, a = pPixels[i].a;
			const int subset = (best_pat_bits >> i) & 1;

			total_r[subset] += r; total_g[subset] += g; total_b[subset] += b; total_a[subset] += a;
			total_c[subset]++;
		}

		int mean_r[2], mean_g[2], mean_b[2], mean_a[2];
		for (uint32_t s = 0; s < 2; s++)
		{
			const uint32_t t = total_c[s];
			const uint32_t h = (t >> 1);

			mean_r[s] = (total_r[s] + h) / t;
			mean_g[s] = (total_g[s] + h) / t;
			mean_b[s] = (total_b[s] + h) / t;
			mean_a[s] = (total_a[s] + h) / t;
		}

		int icov4[2][10] = { { }, { } };

		// 0=rr
		// 1=rg
		// 2=rb
		// 3=ra
		// 
		// 4=gg
		// 5=gb
		// 6=ga
		// 
		// 7=bb
		// 8=ba
		// 
		// 9=aa

		// 0 1 2 3
		//   4 5 6
		//     7 8
		//       9

		// 0 1 2 3
		// 1 4 5 6
		// 2 5 7 8
		// 3 6 8 9

		// trace at 0,4,7,9

		for (uint32_t i = 0; i < 16; i++)
		{
			const int s = (best_pat_bits >> i) & 1;

			int r = (int)pPixels[i].r - mean_r[s];
			int g = (int)pPixels[i].g - mean_g[s];
			int b = (int)pPixels[i].b - mean_b[s];
			int a = (int)pPixels[i].a - mean_a[s];

			icov4[s][0] += r * r; icov4[s][1] += r * g; icov4[s][2] += r * b; icov4[s][3] += r * a;
			icov4[s][4] += g * g; icov4[s][5] += g * b; icov4[s][6] += g * a;
			icov4[s][7] += b * b; icov4[s][8] += b * a;
			icov4[s][9] += a * a;
		}

		int ar[2], ag[2], ab[2], aa[2];

		float slam_to_line_sse_est = 0.0f;

		for (uint32_t s = 0; s < 2; s++)
		{
			const int block_max_var4 = basisu::maximum(icov4[s][0], icov4[s][4], icov4[s][7], icov4[s][9]);

			float cov4[10];
			for (uint32_t i = 0; i < 10; i++)
				cov4[i] = (float)icov4[s][i];

			const float sc4 = block_max_var4 ? (1.0f / (float)block_max_var4) : 0;
			const float wx = sc4 * cov4[0], wy = sc4 * cov4[4], wz = sc4 * cov4[7], wa = sc4 * cov4[9];

			// 0 1 2 3
			// 1 4 5 6
			// 2 5 7 8
			// 3 6 8 9

			const float x0 = cov4[0] * wx + cov4[1] * wy + cov4[2] * wz + cov4[3] * wa;
			const float y0 = cov4[1] * wx + cov4[4] * wy + cov4[5] * wz + cov4[6] * wa;
			const float z0 = cov4[2] * wx + cov4[5] * wy + cov4[7] * wz + cov4[8] * wa;
			const float w0 = cov4[3] * wx + cov4[6] * wy + cov4[8] * wz + cov4[9] * wa;

			const float x1 = cov4[0] * x0 + cov4[1] * y0 + cov4[2] * z0 + cov4[3] * w0;
			const float y1 = cov4[1] * x0 + cov4[4] * y0 + cov4[5] * z0 + cov4[6] * w0;
			const float z1 = cov4[2] * x0 + cov4[5] * y0 + cov4[7] * z0 + cov4[8] * w0;
			const float w1 = cov4[3] * x0 + cov4[6] * y0 + cov4[8] * z0 + cov4[9] * w0;

			slam_to_line_sse_est += estimate_slam_to_line_sse_4D(cov4, x1, y1, z1, w1);

			int saxis_r = 256, saxis_g = 256, saxis_b = 256, saxis_a = 256;

			float k = basisu::maximum(fabsf(x1), fabsf(y1), fabsf(z1), fabsf(w1));
			if (fabsf(k) >= basisu::SMALL_FLOAT_VAL)
			{
				float m = 2048.0f / k;
				saxis_r = (int)(x1 * m);
				saxis_g = (int)(y1 * m);
				saxis_b = (int)(z1 * m);
				saxis_a = (int)(w1 * m);
			}

			ar[s] = (int)((uint32_t)saxis_r << 4U);
			ag[s] = (int)((uint32_t)saxis_g << 4U);
			ab[s] = (int)((uint32_t)saxis_b << 4U);
			aa[s] = (int)((uint32_t)saxis_a << 4U);
		} // s

		int low_dot[2] = { INT_MAX, INT_MAX };
		int high_dot[2] = { INT_MIN, INT_MIN };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int subset = (best_pat_bits >> i) & 1;
			const int saxis_r = ar[subset], saxis_g = ag[subset], saxis_b = ab[subset], saxis_a = aa[subset];

			assert(((pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b + pPixels[i].a * saxis_a) & 0xF) == 0); // sanity
			const int dot = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b + pPixels[i].a * saxis_a) + i;

			low_dot[subset] = basisu::minimum(low_dot[subset], dot);
			high_dot[subset] = basisu::maximum(high_dot[subset], dot);
		}

		int low_c[2] = { low_dot[0] & 15, low_dot[1] & 15 };
		int high_c[2] = { high_dot[0] & 15, high_dot[1] & 15 };

		float quant_err_sse_est = 0;

		for (uint32_t subset = 0; subset < 2; subset++)
		{
			const uint32_t low_pixel = low_c[subset];
			const uint32_t high_pixel = high_c[subset];

			int spans[4];
			for (uint32_t c = 0; c < 4; c++)
				spans[c] = pPixels[high_pixel][c] - pPixels[low_pixel][c];

			// mode 7: 5-bit endpoints, unique pbits, 2 bit weights, 4 chans
			quant_err_sse_est += analytical_quant_est_sse(32, 4, 4, spans, nullptr, (flags & cPackBC7FlagPBitOpt) ? UNIQUE_PBIT_DISCOUNT : 1.0f, total_c[subset]);

		} // subset

		const float total_mode7_est_sse = slam_to_line_sse_est + quant_err_sse_est;

		if (pFinal_sse_est)
			*pFinal_sse_est = total_mode7_est_sse;

		if (total_mode7_est_sse >= sse_est_to_beat)
		{
#if BASISU_BC7F_PERF_STATS
			g_total_mode7_bailouts++;
#endif
			return false;
		}

		uint32_t lr[2], lg[2], lb[2], la[2];
		uint32_t hr[2], hg[2], hb[2], ha[2];
		uint32_t pbits[4];

		for (uint32_t s = 0; s < 2; s++)
		{
			const int lc = low_c[s], hc = high_c[s];

			if (flags & cPackBC7FlagPBitOpt)
			{
				const float q = 1.0f / 255.0f;
				float sxl[4] = { (float)pPixels[lc].r * q, (float)pPixels[lc].g * q, (float)pPixels[lc].b * q, (float)pPixels[lc].a * q };
				float sxh[4] = { (float)pPixels[hc].r * q, (float)pPixels[hc].g * q, (float)pPixels[hc].b * q, (float)pPixels[hc].a * q };

				color_rgba bestMinColor, bestMaxColor;
				determine_unique_pbits(4, 5, sxl, sxh, bestMinColor, bestMaxColor, &pbits[s * 2]);

				lr[s] = bestMinColor.r, lg[s] = bestMinColor.g, lb[s] = bestMinColor.b; la[s] = bestMinColor.a;
				hr[s] = bestMaxColor.r, hg[s] = bestMaxColor.g, hb[s] = bestMaxColor.b; ha[s] = bestMaxColor.a;
			}
			else
			{
				const uint32_t l_pbit = (pPixels[lc].a >= 129);
				const uint32_t h_pbit = (pPixels[hc].a >= 129);

				pbits[s * 2 + 0] = l_pbit;
				pbits[s * 2 + 1] = h_pbit;

				lr[s] = to_5(pPixels[lc].r, l_pbit);
				lg[s] = to_5(pPixels[lc].g, l_pbit);
				lb[s] = to_5(pPixels[lc].b, l_pbit);
				la[s] = to_5(pPixels[lc].a, l_pbit);

				hr[s] = to_5(pPixels[hc].r, h_pbit);
				hg[s] = to_5(pPixels[hc].g, h_pbit);
				hb[s] = to_5(pPixels[hc].b, h_pbit);
				ha[s] = to_5(pPixels[hc].a, h_pbit);
			}
		} // s

		uint8_t cur_weights[16];

		eval_weights_mode7_rgba(pPixels, cur_weights,
			lr, lg, lb, la,
			hr, hg, hb, ha,
			pbits, best_pat_bits);

		float z00[2] = { 0.0f }, z10[2] = { 0.0f }, z11[2] = { 0.0f };
		float q00_r[2] = { 0.0f };
		float q00_g[2] = { 0.0f };
		float q00_b[2] = { 0.0f };
		float q00_a[2] = { 0.0f };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int subset = (best_pat_bits >> i) & 1;
			const uint32_t sel = cur_weights[i];
			assert(sel <= 3);

			z00[subset] += g_bc7_2bit_ls_tab[sel][0];
			z10[subset] += g_bc7_2bit_ls_tab[sel][1];
			z11[subset] += g_bc7_2bit_ls_tab[sel][2];

			const float w = g_bc7_2bit_ls_tab[sel][3];

			q00_r[subset] += w * (float)pPixels[i][0];
			q00_g[subset] += w * (float)pPixels[i][1];
			q00_b[subset] += w * (float)pPixels[i][2];
			q00_a[subset] += w * (float)pPixels[i][3];
		} // i

		for (uint32_t s = 0; s < 2; s++)
		{
			float q10_r = (float)total_r[s] - q00_r[s];
			float q10_g = (float)total_g[s] - q00_g[s];
			float q10_b = (float)total_b[s] - q00_b[s];
			float q10_a = (float)total_a[s] - q00_a[s];

			float z01 = z10[s];

			float det = z00[s] * z11[s] - z01 * z10[s];
			if (fabsf(det) < 1e-8f)
				continue;

			det = 1.0f / det;

			float iz00, iz01, iz10, iz11;
			iz00 = z11[s] * det;
			iz01 = -z01 * det;
			iz10 = -z10[s] * det;
			iz11 = z00[s] * det;

			const float slr = iz10 * q00_r[s] + iz11 * q10_r;
			const float shr = iz00 * q00_r[s] + iz01 * q10_r;

			const float slg = iz10 * q00_g[s] + iz11 * q10_g;
			const float shg = iz00 * q00_g[s] + iz01 * q10_g;

			const float slb = iz10 * q00_b[s] + iz11 * q10_b;
			const float shb = iz00 * q00_b[s] + iz01 * q10_b;

			const float sla = iz10 * q00_a[s] + iz11 * q10_a;
			const float sha = iz00 * q00_a[s] + iz01 * q10_a;

			if (flags & cPackBC7FlagPBitOpt)
			{
				const float q = 1.0f / 255.0f;
				float sxl[4] = { basisu::clamp(slr * q, 0.0f, 1.0f), basisu::clamp(slg * q, 0.0f, 1.0f), basisu::clamp(slb * q, 0.0f, 1.0f), basisu::clamp(sla * q, 0.0f, 1.0f) };
				float sxh[4] = { basisu::clamp(shr * q, 0.0f, 1.0f), basisu::clamp(shg * q, 0.0f, 1.0f), basisu::clamp(shb * q, 0.0f, 1.0f), basisu::clamp(sha * q, 0.0f, 1.0f) };

				color_rgba bestMinColor, bestMaxColor;
				determine_unique_pbits(4, 5, sxl, sxh, bestMinColor, bestMaxColor, &pbits[s * 2]);

				lr[s] = bestMinColor.r, lg[s] = bestMinColor.g, lb[s] = bestMinColor.b; la[s] = bestMinColor.a;
				hr[s] = bestMaxColor.r, hg[s] = bestMaxColor.g, hb[s] = bestMaxColor.b; ha[s] = bestMaxColor.a;
			}
			else
			{
				const uint32_t l_pbit = (sla >= 129.0f);
				const uint32_t h_pbit = (sha >= 129.0f);

				pbits[s * 2 + 0] = l_pbit;
				pbits[s * 2 + 1] = h_pbit;

				lr[s] = to_5_clamp(slr, l_pbit);
				lg[s] = to_5_clamp(slg, l_pbit);
				lb[s] = to_5_clamp(slb, l_pbit);
				la[s] = to_5_clamp(sla, l_pbit);

				hr[s] = to_5_clamp(shr, h_pbit);
				hg[s] = to_5_clamp(shg, h_pbit);
				hb[s] = to_5_clamp(shb, h_pbit);
				ha[s] = to_5_clamp(sha, h_pbit);
			}

		} // s

		if (pActual_sse)
		{
			*pActual_sse = eval_weights_mode7_rgba_sse(pPixels, cur_weights,
				lr, lg, lb, la,
				hr, hg, hb, ha,
				pbits, best_pat_bits);
		}
		else
		{
			eval_weights_mode7_rgba(pPixels, cur_weights,
				lr, lg, lb, la,
				hr, hg, hb, ha,
				pbits, best_pat_bits);
		}

		encode_mode7_rgba_block(pBlock, best_pat_index,
			lr, lg, lb, la,
			hr, hg, hb, ha,
			pbits, cur_weights);

#ifdef _DEBUG
		if (pActual_sse)
		{
			const uint32_t expected_sse = calc_sse(pBlock, pPixels);
			assert(expected_sse == *pActual_sse);
		}
#endif

		return true;
	}

	const int TRIVIAL_BLOCK_THRESH_RGB = 20 * 16; // skip PCA/LS threshold (uses trivial mode 6 encoder)
	const int TRIVIAL_BLOCK_THRESH_RGBA = 2 * 16;

	// dual plane
#if 0
	const int DP_BLOCK_VAR_THRESH = 1 * 16; // use dual plane threshold
	const float STRONG_CORR_THRESH = .98f;
#else
	const int DP_BLOCK_VAR_THRESH = 2 * 16; // use dual plane threshold
	const float STRONG_CORR_THRESH = .85f;
#endif

	// 2-3 subsets
#if 0
	const float HIGH_ORTHO_ENERGY_THRESH = 1.0f * 16.0f; // use 2+ subsets threshold
	const int MIN_BLOCK_MAX_VAR_23SUBSETS = 4 * 16;
	const float ORTHO_RATIO_23SUBSET_RATIO_THRESH = .004f;
#else
	const int MIN_BLOCK_MAX_VAR_23SUBSETS = 100 * 16;
	const float HIGH_ORTHO_ENERGY_THRESH = 1.0f * 16.0f; // use 2+ subsets threshold
	const float ORTHO_RATIO_23SUBSET_RATIO_THRESH = .004f;
#endif

#if 0
	const int DP_BLOCK_VAR_THRESH_RGBA = 2 * 16; // use dual plane threshold
	const float ALPHA_DECORR_THRESHOLD = .9f;
	const float STRONG_DECORR_THRESH_RGBA = .85f;
#else
	const int DP_BLOCK_VAR_THRESH_RGBA = 1 * 16; // use dual plane threshold
	//const float ALPHA_DECORR_THRESHOLD = .98f;
	const float ALPHA_DECORR_THRESHOLD = .995f;
	const float STRONG_DECORR_THRESH_RGBA = .85f;
#endif

	// 3 subsets
	const int MIN_BLOCK_MAX_VAR_3SUBSETS = 500 * 16; // use 3 subsets threshold

	//-------------------------------------------------------------------------------------------------------

	// Note: solid block check assumes A's all == 255.
	void fast_pack_bc7_rgb_analytical(uint8_t* pBlock, const color_rgba* pPixels, uint32_t flags)
	{
		assert(g_bc7_4bit_ls_tab[1][0]);

#if BASISU_BC7F_PERF_STATS
		g_total_rgb_calls++;
#endif

		const uint32_t fc = *(const uint32_t*)&pPixels[0];
		if (fc == *(const uint32_t*)&pPixels[15])
		{
			int k;
			for (k = 1; k < 15; k++)
				if (*(const uint32_t*)&pPixels[k] != fc)
					break;

			if (k == 15)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_solid_blocks++;
#endif

				pack_mode5_solid(pBlock, pPixels[0]);
				return;
			}
		}

		int total_r = 0, total_g = 0, total_b = 0;

		int min_r = 255, min_g = 255, min_b = 255;
		int max_r = 0, max_g = 0, max_b = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;

			total_r += r; total_g += g; total_b += b;

			min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
			max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
		}

		int mean_r = (total_r + 8) >> 4, mean_g = (total_g + 8) >> 4, mean_b = (total_b + 8) >> 4;

		// covar rows are:
		// 0, 1, 2
		// 1, 3, 4
		// 2, 4, 5
		int icov[6] = { 0, 0, 0, 0, 0, 0 };

		for (uint32_t i = 0; i < 16; i++)
		{
			int r = (int)pPixels[i].r - mean_r;
			int g = (int)pPixels[i].g - mean_g;
			int b = (int)pPixels[i].b - mean_b;
			icov[0] += r * r; icov[1] += r * g; icov[2] += r * b;
			icov[3] += g * g; icov[4] += g * b;
			icov[5] += b * b;
		}

		int block_max_var = basisu::maximum(icov[0], icov[3], icov[5]); // not divided by 16, i.e. scaled by 16

		// not redundant due to uint32_t test above, which could be fooled by alpha accidentally passed in
		if (!block_max_var)
		{
#if BASISU_BC7F_PERF_STATS
			g_total_solid_blocks++;
#endif
			pack_mode5_solid(pBlock, pPixels[0]);
			return;
		}

		// check for dual plane, if a single component is very strongly decorrelated then switch to modes 4/5
		int desired_dp_chan = -1;

		if ((flags & cPackBC7FlagUseDualPlaneRGB) && (block_max_var >= DP_BLOCK_VAR_THRESH))
		{
			// 0,1
			// 0,2
			// 1,2
			const bool has_r = icov[0] > 16, has_g = icov[3] > 16, has_b = icov[5] > 16;

			const uint32_t total_active_chans = has_r + has_g + has_b;

			if (total_active_chans >= 2)
			{
				const float r_var = (float)icov[0], g_var = (float)icov[3], b_var = (float)icov[5];

				const float rg_corr = (has_r && has_g) ? fabs((float)icov[1] / sqrtf(r_var * g_var)) : 1.0f;
				const float rb_corr = (has_r && has_b) ? fabs((float)icov[2] / sqrtf(r_var * b_var)) : 1.0f;
				const float gb_corr = (has_g && has_b) ? fabs((float)icov[4] / sqrtf(g_var * b_var)) : 1.0f;

				float min_p = basisu::minimum(rg_corr, rb_corr, gb_corr);
				if (min_p < STRONG_CORR_THRESH)
				{
					if (total_active_chans == 2)
					{
						if (!has_r)
							desired_dp_chan = 1;
						else if (!has_g)
							desired_dp_chan = 0;
						else
							desired_dp_chan = 0;
					}
					else
					{
						// see if rg/rb is weakly correlated vs. gb
						if ((rg_corr < gb_corr) && (rb_corr < gb_corr))
							desired_dp_chan = 0;
						// see if gr/gb is weakly correlated vs. rb
						else if ((rg_corr < rb_corr) && (gb_corr < rb_corr))
							desired_dp_chan = 1;
						// assume b is weakest
						else
							desired_dp_chan = 2;
					}
#if BASISU_BC7F_PERF_STATS
					g_total_dp_valid_chans_rgb++;
#endif
				}
			}
		}

		if ((flags & cPackBC7FlagUseTrivialMode6) && ((desired_dp_chan == -1) && (block_max_var < TRIVIAL_BLOCK_THRESH_RGB)))
		{
			//pack_mode5_solid(pBlock, color_rgba(0, 255, 0, 255));
			//return;

			int low_c = INT_MAX, high_c = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				int y = ((16 * 2) * pPixels[i].r + (16 * 4) * pPixels[i].g + 16 * pPixels[i].b) + i;
				low_c = basisu::minimum(low_c, y);
				high_c = basisu::maximum(high_c, y);
			}

			low_c &= 0xF;
			high_c &= 0xF;

			int p0, p1, lr, lg, lb, hr, hg, hb;

			if (flags & cPackBC7FlagPBitOptMode6)
			{
				// An alternative would be to set A's=1.0 here and bias the p-bit optimizer to lower A RMSE.
				const float q = 1.0f / 255.0f;
				float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, 0 };
				float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, 0 };

				color_rgba bestMinColor, bestMaxColor;
				uint32_t best_pbits[2];
				determine_unique_pbits(3, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

				p0 = best_pbits[0], p1 = best_pbits[1];
				lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b;
				hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b;
			}
			else
			{
				p0 = 1;
				p1 = 1;

				lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0);
				hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1);
			}

			uint8_t cur_weights[16];

#if BASISU_BC7F_USE_SSE41
			eval_weights_mode6_rgb_sse41(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);
#else
			eval_weights_mode6_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);
#endif

			encode_mode6_rgba_block(pBlock,
				lr, lg, lb, 127, p0,
				hr, hg, hb, 127, p1,
				cur_weights);

#if BASISU_BC7F_PERF_STATS
			g_total_trivial_mode6_blocks++;
#endif
			return;
		}

		float cov[6];
		for (uint32_t i = 0; i < 6; i++)
			cov[i] = (float)icov[i];

		const float sc = block_max_var ? (1.0f / (float)block_max_var) : 0;
		const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

		const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
		const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
		const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

		// quite rough mode 6 SSE estimate (explictly higher bound): if some other mode can't even beat this, don't use it and we fall back to a decently strong mode 6
		const int spans[4] = { max_r - min_r, max_g - min_g, max_b - min_b, 0 };
				
		// need_sse_estimates MUST be set correctly or subtle mode selection issues will occur.
		const bool need_sse_estimates = ((flags & cPackBC7FlagUse2SubsetsRGB) != 0) || (desired_dp_chan >= 0);

		float mode6_ortho_ratio = 0;
		const float mode6_slam_to_line_sse_est = need_sse_estimates ? estimate_slam_to_line_sse_3D(cov, alt_xr, alt_xg, alt_xb, &mode6_ortho_ratio) : 0;
		const float mode6_sse_est = need_sse_estimates ? (mode6_slam_to_line_sse_est + analytical_quant_est_sse(128, 16, 3, spans, nullptr, 1.0f, 16)) : 0;

		// Prefer 2/3-subsets over dual plane
		// TODO: Use mode 6 sse est?
		if ((flags & cPackBC7FlagUse2SubsetsRGB) && (block_max_var >= MIN_BLOCK_MAX_VAR_23SUBSETS) && (mode6_ortho_ratio > ORTHO_RATIO_23SUBSET_RATIO_THRESH))
		{
			assert(need_sse_estimates);

			const bool high_ortho_energy_flag = (mode6_slam_to_line_sse_est >= HIGH_ORTHO_ENERGY_THRESH);

			if (high_ortho_energy_flag)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_high_ortho_energy++;
#endif
				//pack_mode5_solid(pBlock, color_rgba(255, 255, 0, 255));
				//return;

				if ((flags & cPackBC7FlagUse3SubsetsRGB) && (block_max_var >= MIN_BLOCK_MAX_VAR_3SUBSETS))
				{
					//pack_mode5_solid(pBlock, color_rgba(255, 0, 255, 255));
					//return;

#if 0
					if (pack_mode0_or_2_rgb(pBlock, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, mode6_sse_est, flags))
					{
						return;
					}
#else
					float mode0_or_2_sse_est = 1e+9f;
					if (pack_mode0_or_2_rgb(pBlock, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, mode6_sse_est, flags, &mode0_or_2_sse_est))
					{
						float mode1_or_3_sse_est = 1e+9f;

						uint8_t temp_2subset_block[sizeof(basist::bc7_block)];
						if (pack_mode1_or_3_rgb(temp_2subset_block, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, mode0_or_2_sse_est, flags, &mode1_or_3_sse_est))
						{
							assert(mode1_or_3_sse_est < mode0_or_2_sse_est);
							memcpy(pBlock, temp_2subset_block, sizeof(basist::bc7_block));
						}

						return;
					}
#endif
				}

				if (pack_mode1_or_3_rgb(pBlock, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, mode6_sse_est, flags))
					return;
			}
		}

		// Use dual plane over mode 6
		if (desired_dp_chan >= 0)
		{
			assert(need_sse_estimates);

			if (pack_mode4_or_5(pBlock, pPixels, desired_dp_chan, mode6_sse_est, flags))
				return;

		} // if (desired_dp_chan >= 0)

		int saxis_r = 306, saxis_g = 601, saxis_b = 117;

		float k = basisu::maximum(fabsf(alt_xr), fabsf(alt_xg), fabsf(alt_xb));
		if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
		{
			float m = 2048.0f / k;
			saxis_r = (int)(alt_xr * m);
			saxis_g = (int)(alt_xg * m);
			saxis_b = (int)(alt_xb * m);
		}

		saxis_r = (int)((uint32_t)saxis_r << 4U);
		saxis_g = (int)((uint32_t)saxis_g << 4U);
		saxis_b = (int)((uint32_t)saxis_b << 4U);

		int low_dot = INT_MAX, high_dot = INT_MIN;

#if BASISU_BC7F_USE_SSE41
		int low_c, high_c;
		bc7_proj_minmax_indices_sse41(pPixels, saxis_r, saxis_g, saxis_b, &low_c, &high_c);
#else
		for (uint32_t i = 0; i < 16; i += 4)
		{
			assert(((pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) & 0xF) == 0); // sanity
			assert(((pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b) & 0xF) == 0);
			assert(((pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b) & 0xF) == 0);
			assert(((pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b) & 0xF) == 0);

			const int dot0 = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) + i;
			const int dot1 = (pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b) + i + 1;
			const int dot2 = (pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b) + i + 2;
			const int dot3 = (pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b) + i + 3;

			int min_d01 = basisu::minimum(dot0, dot1);
			int max_d01 = basisu::maximum(dot0, dot1);

			int min_d23 = basisu::minimum(dot2, dot3);
			int max_d23 = basisu::maximum(dot2, dot3);

			int min_d = basisu::minimum(min_d01, min_d23);
			int max_d = basisu::maximum(max_d01, max_d23);

			low_dot = basisu::minimum(low_dot, min_d);
			high_dot = basisu::maximum(high_dot, max_d);
		}

		int low_c = low_dot & 15;
		int high_c = high_dot & 15;
#endif

		int p0, p1, lr, lg, lb, hr, hg, hb;

		if (flags & cPackBC7FlagPBitOptMode6)
		{
			const float q = 1.0f / 255.0f;
			float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, 0 };
			float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, 0 };

			color_rgba bestMinColor, bestMaxColor;
			uint32_t best_pbits[2];
			determine_unique_pbits(3, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

			p0 = best_pbits[0], p1 = best_pbits[1];
			lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b;
			hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b;
		}
		else
		{
			// explictly force pbits to 1, that way alpha is always 255 and we don't slow down the entire encoder by 4-8% for a tiny ~.1 dB PSNR gain (not worth it)
			p0 = 1, p1 = 1;
			lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0);
			hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1);
		}

		uint8_t cur_weights[16];

#if BASISU_BC7F_USE_SSE41
		eval_weights_mode6_rgb_sse41(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);
#else
		eval_weights_mode6_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);
#endif

		vec4F xl, xh;
		bool res = compute_least_squares_endpoints_3D(
			16, cur_weights, 16,
			g_bc7_4bit_ls_tab,
			xl, xh,
			pPixels,
			(float)total_r, (float)total_g, (float)total_b);

		if (res)
		{
			if (flags & cPackBC7FlagPBitOptMode6)
			{
				const float q = 1.0f / 255.0f;
				float sxl[4] = { xl[0] * q, xl[1] * q, xl[2] * q, 0.0f };
				float sxh[4] = { xh[0] * q, xh[1] * q, xh[2] * q, 0.0f };

				color_rgba bestMinColor, bestMaxColor;
				uint32_t best_pbits[2];
				determine_unique_pbits(
					3, 7, sxl, sxh,
					bestMinColor, bestMaxColor, best_pbits);

				p0 = best_pbits[0], p1 = best_pbits[1];
				lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b;
				hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b;
			}
			else
			{
				p0 = 1; p1 = 1;
				lr = to_7(xl[0], p0);
				lg = to_7(xl[1], p0);
				lb = to_7(xl[2], p0);

				hr = to_7(xh[0], p1);
				hg = to_7(xh[1], p1);
				hb = to_7(xh[2], p1);
			}

#if BASISU_BC7F_USE_SSE41
			eval_weights_mode6_rgb_sse41(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);
#else
			eval_weights_mode6_rgb(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);
#endif
		}

		//pack_mode5_solid(pBlock, color_rgba(0, 0, 255, 255));
		//return;

		// pbits set to 1 to ensure alpha is always decoded to fully opaque (255)
		encode_mode6_rgba_block(pBlock,
			lr, lg, lb, 127, p0,
			hr, hg, hb, 127, p1,
			cur_weights);
	}

	//-------------------------------------------------------------------------------------------------------
	const int MIN_BLOCK_MAX_VAR_23SUBSETS_RGBA = 100 * 16;
	const float HIGH_ORTHO_ENERGY_THRESH_RGBA = 1.0f * 16.0f; // use 2+ subsets threshold
	const float ORTHO_RATIO_23SUBSET_RATIO_THRESH_RGBA = .004f;

	uint32_t fast_pack_bc7_rgb_partial_analytical(uint8_t* pBlock, const color_rgba* pPixels, uint32_t flags)
	{
		assert(g_bc7_4bit_ls_tab[1][0]);

#if BASISU_BC7F_PERF_STATS
		g_total_rgb_calls++;
#endif

		const uint32_t fc = *(const uint32_t*)&pPixels[0];
		if (fc == *(const uint32_t*)&pPixels[15])
		{
			int k;
			for (k = 1; k < 15; k++)
				if (*(const uint32_t*)&pPixels[k] != fc)
					break;

			if (k == 15)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_solid_blocks++;
#endif

				pack_mode5_solid(pBlock, pPixels[0]);
				return 0;
			}
		}

		int total_r = 0, total_g = 0, total_b = 0;

		int min_r = 255, min_g = 255, min_b = 255;
		int max_r = 0, max_g = 0, max_b = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;

			total_r += r; total_g += g; total_b += b;

			min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b);
			max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b);
		}

		int mean_r = (total_r + 8) >> 4, mean_g = (total_g + 8) >> 4, mean_b = (total_b + 8) >> 4;

		// covar rows are:
		// 0, 1, 2
		// 1, 3, 4
		// 2, 4, 5
		int icov[6] = { 0, 0, 0, 0, 0, 0 };

		for (uint32_t i = 0; i < 16; i++)
		{
			int r = (int)pPixels[i].r - mean_r;
			int g = (int)pPixels[i].g - mean_g;
			int b = (int)pPixels[i].b - mean_b;
			icov[0] += r * r; icov[1] += r * g; icov[2] += r * b;
			icov[3] += g * g; icov[4] += g * b;
			icov[5] += b * b;
		}

		int block_max_var = basisu::maximum(icov[0], icov[3], icov[5]); // not divided by 16, i.e. scaled by 16

		// not redundant due to uint32_t test above, which could be fooled by alpha accidentally passed in
		if (!block_max_var)
		{
#if BASISU_BC7F_PERF_STATS
			g_total_solid_blocks++;
#endif
			pack_mode5_solid(pBlock, pPixels[0]);
			return 0;
		}

		// check for dual plane, if a single component is very strongly decorrelated then switch to modes 4/5
		int desired_dp_chan = -1;

		const bool non_analytical_flag = (flags & cPackBC7FlagNonAnalyticalRGB) != 0;
		if (non_analytical_flag)
		{
			assert(flags & cPackBC7FlagPartiallyAnalyticalRGB);
		}

		if ((flags & cPackBC7FlagUseDualPlaneRGB) &&
			((!non_analytical_flag && (block_max_var >= DP_BLOCK_VAR_THRESH)) || (non_analytical_flag && (block_max_var >= (DP_BLOCK_VAR_THRESH / 2)))))
		{
			// 0,1
			// 0,2
			// 1,2
			const bool has_r = icov[0] > 16, has_g = icov[3] > 16, has_b = icov[5] > 16;

			const uint32_t total_active_chans = has_r + has_g + has_b;

			if (total_active_chans >= 2)
			{
				const float r_var = (float)icov[0], g_var = (float)icov[3], b_var = (float)icov[5];

				const float rg_corr = (has_r && has_g) ? fabs((float)icov[1] / sqrtf(r_var * g_var)) : 1.0f;
				const float rb_corr = (has_r && has_b) ? fabs((float)icov[2] / sqrtf(r_var * b_var)) : 1.0f;
				const float gb_corr = (has_g && has_b) ? fabs((float)icov[4] / sqrtf(g_var * b_var)) : 1.0f;

				float min_p = basisu::minimum(rg_corr, rb_corr, gb_corr);

				const float corr_thresh = non_analytical_flag ? .999f : STRONG_CORR_THRESH;

				if (min_p < corr_thresh)
				{
					if (total_active_chans == 2)
					{
						if (!has_r)
							desired_dp_chan = 1;
						else if (!has_g)
							desired_dp_chan = 0;
						else
							desired_dp_chan = 0;
					}
					else
					{
						// see if rg/rb is weakly correlated vs. gb
						if ((rg_corr < gb_corr) && (rb_corr < gb_corr))
							desired_dp_chan = 0;
						// see if gr/gb is weakly correlated vs. rb
						else if ((rg_corr < rb_corr) && (gb_corr < rb_corr))
							desired_dp_chan = 1;
						// assume b is weakest
						else
							desired_dp_chan = 2;
					}
#if BASISU_BC7F_PERF_STATS
					g_total_dp_valid_chans_rgb++;
#endif
				}
			}
		}

		if ((flags & cPackBC7FlagUseTrivialMode6) && ((desired_dp_chan == -1) && (block_max_var < TRIVIAL_BLOCK_THRESH_RGB)))
		{
			int low_c = INT_MAX, high_c = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				int y = ((16 * 2) * pPixels[i].r + (16 * 4) * pPixels[i].g + 16 * pPixels[i].b) + i;
				low_c = basisu::minimum(low_c, y);
				high_c = basisu::maximum(high_c, y);
			}

			low_c &= 0xF;
			high_c &= 0xF;

			int p0, p1, lr, lg, lb, hr, hg, hb;

			if (flags & cPackBC7FlagPBitOptMode6)
			{
				// An alternative would be to set A's=1.0 here and bias the p-bit optimizer to lower A RMSE.
				const float q = 1.0f / 255.0f;
				float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, 0 };
				float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, 0 };

				color_rgba bestMinColor, bestMaxColor;
				uint32_t best_pbits[2];
				determine_unique_pbits(3, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

				p0 = best_pbits[0], p1 = best_pbits[1];
				lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b;
				hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b;
			}
			else
			{
				p0 = 1;
				p1 = 1;

				lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0);
				hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1);
			}

			uint8_t cur_weights[16];
			uint32_t mode6_actual_sse = eval_weights_mode6_rgb_sse(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);

			encode_mode6_rgba_block(pBlock,
				lr, lg, lb, 127, p0,
				hr, hg, hb, 127, p1,
				cur_weights);

#if BASISU_BC7F_PERF_STATS
			g_total_trivial_mode6_blocks++;
#endif

#ifdef _DEBUG
			{
				// Final sanity checking.
				uint32_t expected_actual_sse = calc_sse(pBlock, pPixels);
				assert(expected_actual_sse == mode6_actual_sse);
			}
#endif

			return mode6_actual_sse;
		}

		float cov[6];
		for (uint32_t i = 0; i < 6; i++)
			cov[i] = (float)icov[i];

		const float sc = block_max_var ? (1.0f / (float)block_max_var) : 0;
		const float wx = sc * cov[0], wy = sc * cov[3], wz = sc * cov[5];

		const float alt_xr = cov[0] * wx + cov[1] * wy + cov[2] * wz;
		const float alt_xg = cov[1] * wx + cov[3] * wy + cov[4] * wz;
		const float alt_xb = cov[2] * wx + cov[4] * wy + cov[5] * wz;

		int saxis_r = 306, saxis_g = 601, saxis_b = 117;

		float k = basisu::maximum(fabsf(alt_xr), fabsf(alt_xg), fabsf(alt_xb));
		if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
		{
			float m = 2048.0f / k;
			saxis_r = (int)(alt_xr * m);
			saxis_g = (int)(alt_xg * m);
			saxis_b = (int)(alt_xb * m);
		}

		saxis_r = (int)((uint32_t)saxis_r << 4U);
		saxis_g = (int)((uint32_t)saxis_g << 4U);
		saxis_b = (int)((uint32_t)saxis_b << 4U);

		int low_dot = INT_MAX, high_dot = INT_MIN;

#if BASISU_BC7F_USE_SSE41
		int low_c, high_c;
		bc7_proj_minmax_indices_sse41(pPixels, saxis_r, saxis_g, saxis_b, &low_c, &high_c);
#else
		for (uint32_t i = 0; i < 16; i += 4)
		{
			assert(((pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) & 0xF) == 0); // sanity
			assert(((pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b) & 0xF) == 0);
			assert(((pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b) & 0xF) == 0);
			assert(((pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b) & 0xF) == 0);

			const int dot0 = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b) + i;
			const int dot1 = (pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b) + i + 1;
			const int dot2 = (pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b) + i + 2;
			const int dot3 = (pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b) + i + 3;

			int min_d01 = basisu::minimum(dot0, dot1);
			int max_d01 = basisu::maximum(dot0, dot1);

			int min_d23 = basisu::minimum(dot2, dot3);
			int max_d23 = basisu::maximum(dot2, dot3);

			int min_d = basisu::minimum(min_d01, min_d23);
			int max_d = basisu::maximum(max_d01, max_d23);

			low_dot = basisu::minimum(low_dot, min_d);
			high_dot = basisu::maximum(high_dot, max_d);
		}

		int low_c = low_dot & 15;
		int high_c = high_dot & 15;
#endif

		int p0, p1, lr, lg, lb, hr, hg, hb;

		if (flags & cPackBC7FlagPBitOptMode6)
		{
			const float q = 1.0f / 255.0f;
			float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, 0 };
			float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, 0 };

			color_rgba bestMinColor, bestMaxColor;
			uint32_t best_pbits[2];
			determine_unique_pbits(3, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

			p0 = best_pbits[0], p1 = best_pbits[1];
			lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b;
			hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b;
		}
		else
		{
			// explictly force pbits to 1, that way alpha is always 255 and we don't slow down the entire encoder by 4-8% for a tiny ~.1 dB PSNR gain (not worth it)
			p0 = 1, p1 = 1;
			lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0);
			hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1);
		}

		uint8_t cur_weights[16];

		uint32_t mode6_actual_sse = eval_weights_mode6_rgb_sse(pPixels, cur_weights, lr, lg, lb, hr, hg, hb, p0, p1);

		if (mode6_actual_sse)
		{
			vec4F xl, xh;
			bool res = compute_least_squares_endpoints_3D(
				16, cur_weights, 16,
				g_bc7_4bit_ls_tab,
				xl, xh,
				pPixels,
				(float)total_r, (float)total_g, (float)total_b);

			if (res)
			{
				int trial_p0, trial_p1, trial_lr, trial_lg, trial_lb, trial_hr, trial_hg, trial_hb;

				if (flags & cPackBC7FlagPBitOptMode6)
				{
					const float q = 1.0f / 255.0f;
					float sxl[4] = { xl[0] * q, xl[1] * q, xl[2] * q, 0.0f };
					float sxh[4] = { xh[0] * q, xh[1] * q, xh[2] * q, 0.0f };

					color_rgba bestMinColor, bestMaxColor;
					uint32_t best_pbits[2];
					determine_unique_pbits(
						3, 7, sxl, sxh,
						bestMinColor, bestMaxColor, best_pbits);

					trial_p0 = best_pbits[0], trial_p1 = best_pbits[1];
					trial_lr = bestMinColor.r, trial_lg = bestMinColor.g, trial_lb = bestMinColor.b;
					trial_hr = bestMaxColor.r, trial_hg = bestMaxColor.g, trial_hb = bestMaxColor.b;
				}
				else
				{
					trial_p0 = 1; trial_p1 = 1;
					trial_lr = to_7(xl[0], trial_p0);
					trial_lg = to_7(xl[1], trial_p0);
					trial_lb = to_7(xl[2], trial_p0);

					trial_hr = to_7(xh[0], trial_p1);
					trial_hg = to_7(xh[1], trial_p1);
					trial_hb = to_7(xh[2], trial_p1);
				}

				uint8_t trial_weights[16];
				uint32_t mode6_ls_actual_sse = eval_weights_mode6_rgb_sse(pPixels, trial_weights, trial_lr, trial_lg, trial_lb, trial_hr, trial_hg, trial_hb, trial_p0, trial_p1);
				if (mode6_ls_actual_sse < mode6_actual_sse)
				{
					mode6_actual_sse = mode6_ls_actual_sse;
					memcpy(cur_weights, trial_weights, 16);
					p0 = trial_p0; p1 = trial_p1;
					lr = trial_lr; lg = trial_lg; lb = trial_lb;
					hr = trial_hr; hg = trial_hg; hb = trial_hb;
				}
			}
		}

		uint32_t mode02_actual_sse = UINT32_MAX;
		uint8_t mode02_candidate_block[sizeof(basist::bc7_block)];

		uint32_t mode13_actual_sse = UINT32_MAX;
		uint8_t mode13_candidate_block[sizeof(basist::bc7_block)];

		uint32_t mode45_actual_sse = UINT32_MAX;
		uint8_t mode45_candidate_block[sizeof(basist::bc7_block)];

		if (mode6_actual_sse)
		{
			if (non_analytical_flag)
			{
				// No gates: very expensive.
				if (flags & cPackBC7FlagUse2SubsetsRGB)
				{
					if (flags & cPackBC7FlagUse3SubsetsRGB)
					{
						pack_mode0_or_2_rgb(mode02_candidate_block, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, 1e+9f, flags, nullptr, &mode02_actual_sse);
					}

					pack_mode1_or_3_rgb(mode13_candidate_block, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, 1e+9f, flags, nullptr, &mode13_actual_sse);
				}

				if (flags & cPackBC7FlagUseDualPlaneRGB)
					pack_mode4_or_5(mode45_candidate_block, pPixels, (desired_dp_chan >= 0) ? desired_dp_chan : 1, 1e+9f, flags, nullptr, &mode45_actual_sse); // todo: determine best def channel here
			}
			else
			{
				float mode6_ortho_ratio;
				const float mode6_slam_to_line_sse_est = estimate_slam_to_line_sse_3D(cov, alt_xr, alt_xg, alt_xb, &mode6_ortho_ratio);

				if ((flags & cPackBC7FlagUse2SubsetsRGB) && (block_max_var >= MIN_BLOCK_MAX_VAR_23SUBSETS) && (mode6_ortho_ratio > ORTHO_RATIO_23SUBSET_RATIO_THRESH))
				{
					const bool high_ortho_energy_flag = (mode6_slam_to_line_sse_est >= HIGH_ORTHO_ENERGY_THRESH);

					if (high_ortho_energy_flag)
					{
#if BASISU_BC7F_PERF_STATS
						g_total_high_ortho_energy++;
#endif

						if ((flags & cPackBC7FlagUse3SubsetsRGB) && (block_max_var >= MIN_BLOCK_MAX_VAR_3SUBSETS))
						{
							pack_mode0_or_2_rgb(mode02_candidate_block, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, 1e+9f, flags, nullptr, &mode02_actual_sse);
							pack_mode1_or_3_rgb(mode13_candidate_block, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, 1e+9f, flags, nullptr, &mode13_actual_sse);
						}
						else
						{
							pack_mode1_or_3_rgb(mode13_candidate_block, pPixels, alt_xr, alt_xg, alt_xb, mean_r, mean_g, mean_b, 1e+9f, flags, nullptr, &mode13_actual_sse);
						}
					}
				}

				if (desired_dp_chan >= 0)
				{
					assert(flags & cPackBC7FlagUseDualPlaneRGB);

					pack_mode4_or_5(mode45_candidate_block, pPixels, desired_dp_chan, 1e+9f, flags, nullptr, &mode45_actual_sse);

				} // if (desired_dp_chan >= 0)
			}
		}

		const uint32_t best_actual_sse = basisu::minimum(mode6_actual_sse, mode02_actual_sse, mode13_actual_sse, mode45_actual_sse);

		if (mode6_actual_sse == best_actual_sse)
		{
			// pbits set to 1 to ensure alpha is always decoded to fully opaque (255)
			encode_mode6_rgba_block(pBlock,
				lr, lg, lb, 127, p0,
				hr, hg, hb, 127, p1,
				cur_weights);
		}
		else if ((mode45_actual_sse != UINT32_MAX) && (best_actual_sse == mode45_actual_sse))
		{
			memcpy(pBlock, mode45_candidate_block, sizeof(basist::bc7_block));
		}
		else if ((mode02_actual_sse != UINT32_MAX) && (best_actual_sse == mode02_actual_sse))
		{
			memcpy(pBlock, mode02_candidate_block, sizeof(basist::bc7_block));
		}
		else if ((mode13_actual_sse != UINT32_MAX) && (best_actual_sse == mode13_actual_sse))
		{
			memcpy(pBlock, mode13_candidate_block, sizeof(basist::bc7_block));
		}
		else
		{
			assert(0);
		}

#ifdef _DEBUG
		{
			// Final sanity checking.
			uint32_t expected_actual_sse = calc_sse(pBlock, pPixels);
			assert(expected_actual_sse == best_actual_sse);
		}
#endif

		return best_actual_sse;
	}

	//-------------------------------------------------------------------------------------------------------

	void fast_pack_bc7_rgba_analytical(uint8_t* pBlock, const color_rgba* pPixels, uint32_t flags)
	{
		assert(g_bc7_4bit_ls_tab[1][0]);

#if BASISU_BC7F_PERF_STATS
		g_total_rgba_calls++;
#endif

		const uint32_t fc = *(const uint32_t*)&pPixels[0];
		if (fc == *(const uint32_t*)&pPixels[15])
		{
			int k;
			for (k = 1; k < 15; k++)
				if (*(const uint32_t*)&pPixels[k] != fc)
					break;

			if (k == 15)
			{
				pack_mode5_solid(pBlock, pPixels[0]);
				return;
			}
		}

		int total_r = 0, total_g = 0, total_b = 0, total_a = 0;
		int min_r = 255, min_g = 255, min_b = 255, min_a = 255;
		int max_r = 0, max_g = 0, max_b = 0, max_a = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b, a = pPixels[i].a;

			total_r += r; total_g += g; total_b += b; total_a += a;

			min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b); min_a = basisu::minimum(min_a, a);
			max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b); max_a = basisu::maximum(max_a, a);
		}

		assert((min_r != max_r) || (min_g != max_g) || (min_b != max_b) || (min_a != max_a));

		const int mean_r = (total_r + 8) >> 4, mean_g = (total_g + 8) >> 4, mean_b = (total_b + 8) >> 4, mean_a = (total_a + 8) >> 4;

		// covar rows are:
		int icov4[10] = { };

		// 0=rr
		// 1=rg
		// 2=rb
		// 3=ra
		// 
		// 4=gg
		// 5=gb
		// 6=ga
		// 
		// 7=bb
		// 8=ba
		// 
		// 9=aa

		// 0 1 2 3
		//   4 5 6
		//     7 8
		//       9

		// 0 1 2 3
		// 1 4 5 6
		// 2 5 7 8
		// 3 6 8 9

		// trace at 0,4,7,9

		for (uint32_t i = 0; i < 16; i++)
		{
			const int r = (int)pPixels[i].r - mean_r, g = (int)pPixels[i].g - mean_g, b = (int)pPixels[i].b - mean_b, a = (int)pPixels[i].a - mean_a;

			icov4[0] += r * r; icov4[1] += r * g; icov4[2] += r * b; icov4[3] += r * a;
			icov4[4] += g * g; icov4[5] += g * b; icov4[6] += g * a;
			icov4[7] += b * b; icov4[8] += b * a;
			icov4[9] += a * a;
		}

		const int block_max_var4 = basisu::maximum(icov4[0], icov4[4], icov4[7], icov4[9]); // not divided by 16, i.e. scaled by 16
		assert(block_max_var4); // solid blocks already filtered out

		// check for dual plane, if a single component is very strongly decorrelated then switch to modes 4/5
		int desired_dp_chan = -1;

		if ((flags & cPackBC7FlagUseDualPlaneRGBA) && (block_max_var4 >= DP_BLOCK_VAR_THRESH_RGBA))
		{
			// Prefer A, if not strongly decorrelated then check RGB.
			const float r_var = (float)icov4[0], g_var = (float)icov4[4], b_var = (float)icov4[7], a_var = (float)icov4[9];

			const bool has_a = icov4[9] > 0;

			if (has_a)
			{
				const float p_03 = icov4[0] ? fabs((float)icov4[3] / sqrtf(r_var * a_var)) : 1.0f;
				const float p_13 = icov4[4] ? fabs((float)icov4[6] / sqrtf(g_var * a_var)) : 1.0f;
				const float p_23 = icov4[7] ? fabs((float)icov4[8] / sqrtf(b_var * a_var)) : 1.0f;

				const float min_p = basisu::minimum(p_03, p_13, p_23);
				if (min_p < ALPHA_DECORR_THRESHOLD)
				{
					desired_dp_chan = 3;
#if BASISU_BC7F_PERF_STATS
					g_total_dp_valid_chans_a++;
#endif
				}
			}

			if ((desired_dp_chan < 0) && ((flags & cPackBC7FlagDisableRGBDualPlane) == 0))
			{
				const bool has_r = icov4[0] > 16, has_g = icov4[4] > 16, has_b = icov4[7] > 16;
				const uint32_t total_active_chans_rgb = has_r + has_g + has_b;

				if (total_active_chans_rgb >= 2)
				{
					const float rg_corr = (has_r && has_g) ? fabs((float)icov4[1] / sqrtf(r_var * g_var)) : 1.0f;
					const float rb_corr = (has_r && has_b) ? fabs((float)icov4[2] / sqrtf(r_var * b_var)) : 1.0f;
					const float gb_corr = (has_g && has_b) ? fabs((float)icov4[5] / sqrtf(g_var * b_var)) : 1.0f;

					float min_p = basisu::minimum(rg_corr, rb_corr, gb_corr);
					if (min_p < STRONG_DECORR_THRESH_RGBA)
					{
						if (total_active_chans_rgb == 2)
						{
							if (!has_r)
								desired_dp_chan = 1;
							else if (!has_g)
								desired_dp_chan = 0;
							else
								desired_dp_chan = 0;
						}
						else
						{
							// see if rg/rb is weakly correlated vs. gb
							if ((rg_corr < gb_corr) && (rb_corr < gb_corr))
								desired_dp_chan = 0;
							// see if gr/gb is weakly correlated vs. rb
							else if ((rg_corr < rb_corr) && (gb_corr < rb_corr))
								desired_dp_chan = 1;
							// assume b is weakest
							else
								desired_dp_chan = 2;
						}
#if BASISU_BC7F_PERF_STATS
						g_total_dp_valid_chans_rgb++;
#endif
					}
				}
			}
		}

		if ((flags & cPackBC7FlagUseTrivialMode6) && ((desired_dp_chan == -1) && (block_max_var4 < TRIVIAL_BLOCK_THRESH_RGBA)))
		{
			//pack_mode5_solid(pBlock, color_rgba(0, 255, 0, 255));
			//return;

			int low_c = INT_MAX, high_c = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				int y = ((16 * 2) * pPixels[i].r + (16 * 4) * pPixels[i].g + 16 * pPixels[i].b + (16 * 4) * pPixels[i].a);
				assert((y & 0xF) == 0);
				y += i;
				low_c = basisu::minimum(low_c, y);
				high_c = basisu::maximum(high_c, y);
			}

			low_c &= 0xF;
			high_c &= 0xF;

			int p0, p1, lr, lg, lb, la, hr, hg, hb, ha;

			if (flags & cPackBC7FlagPBitOptMode6)
			{
				const float q = 1.0f / 255.0f;
				float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, (float)pPixels[low_c].a * q };
				float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, (float)pPixels[high_c].a * q };

				color_rgba bestMinColor, bestMaxColor;
				uint32_t best_pbits[2];
				determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

				p0 = best_pbits[0], p1 = best_pbits[1];
				lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b, la = bestMinColor.a;
				hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b, ha = bestMaxColor.a;
			}
			else
			{
				p0 = pPixels[low_c].a > 128;
				p1 = pPixels[high_c].a > 128;

				lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0), la = to_7(pPixels[low_c].a, p0);
				hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1), ha = to_7(pPixels[high_c].a, p1);
			}

			uint8_t cur_weights[16];
			eval_weights_mode6_rgba(pPixels, cur_weights,
				lr, lg, lb, la, p0,
				hr, hg, hb, ha, p1);

			encode_mode6_rgba_block(pBlock,
				lr, lg, lb, la, p0,
				hr, hg, hb, ha, p1,
				cur_weights);

#if BASISU_BC7F_PERF_STATS
			g_total_trivial_mode6_blocks++;
#endif
			return;
		}

		float cov4[10];
		for (uint32_t i = 0; i < 10; i++)
			cov4[i] = (float)icov4[i];

		// all channel pairs:
		// 0,1=1
		// 0,2=2
		// 0,3=3
		// 1,2=5
		// 1,3=6
		// 2,3=8
		//const float r_var = cov4[0], g_var = cov4[4], b_var = cov4[7], a_var = cov4[9];

		const float sc4 = block_max_var4 ? (1.0f / (float)block_max_var4) : 0;
		float wx = sc4 * cov4[0], wy = sc4 * cov4[4], wz = sc4 * cov4[7], wa = sc4 * cov4[9];

		// 0 1 2 3
		// 1 4 5 6
		// 2 5 7 8
		// 3 6 8 9

		// TODO
		float x1, y1, z1, w1;
		for (uint32_t i = 0; i < 4; i++)
		{
			x1 = cov4[0] * wx + cov4[1] * wy + cov4[2] * wz + cov4[3] * wa;
			y1 = cov4[1] * wx + cov4[4] * wy + cov4[5] * wz + cov4[6] * wa;
			z1 = cov4[2] * wx + cov4[5] * wy + cov4[7] * wz + cov4[8] * wa;
			w1 = cov4[3] * wx + cov4[6] * wy + cov4[8] * wz + cov4[9] * wa;

			float t = sqrtf(x1 * x1 + y1 * y1 + z1 * z1 + w1 * w1);
			if (t > basisu::SMALL_FLOAT_VAL)
			{
				t = 1.0f / t;
				x1 *= t; y1 *= t; z1 *= t; w1 *= t;
			}
			else
			{
				x1 = y1 = z1 = w1 = .25f;
			}

			wx = x1; wy = y1; wz = z1; wa = w1;
		}

		const int spans[4] = { max_r - min_r, max_g - min_g, max_b - min_b, max_a - min_a };

		float mode6_ortho_ratio;
		const float mode6_slam_to_line_sse_est = estimate_slam_to_line_sse_4D(cov4, x1, y1, z1, w1, &mode6_ortho_ratio);
		const float mode6_sse_est = (mode6_slam_to_line_sse_est + analytical_quant_est_sse(128, 16, 4, spans, nullptr, 1.0f, 16));

		float mode45_sse_est = 1e+9f, mode7_sse_est = 1e+9f;

		uint8_t mode45_block[sizeof(basist::bc7_block)];
		const bool mode45_valid_flag = (desired_dp_chan >= 0) ? pack_mode4_or_5(mode45_block, pPixels, desired_dp_chan, mode6_sse_est, flags, &mode45_sse_est) : false;
		BASISU_NOTE_UNUSED(mode45_valid_flag);

		uint8_t mode7_block[sizeof(basist::bc7_block)];
		bool mode7_valid_flag = false;
		BASISU_NOTE_UNUSED(mode7_valid_flag);

		if ((flags & cPackBC7FlagUse2SubsetsRGBA) && (block_max_var4 >= MIN_BLOCK_MAX_VAR_23SUBSETS_RGBA) && (mode6_ortho_ratio > ORTHO_RATIO_23SUBSET_RATIO_THRESH_RGBA))
		{
			const bool high_ortho_energy_flag = (mode6_slam_to_line_sse_est >= HIGH_ORTHO_ENERGY_THRESH_RGBA);

			if (high_ortho_energy_flag)
			{
#if BASISU_BC7F_PERF_STATS
				g_total_high_ortho_energy++;
#endif
				mode7_valid_flag = pack_mode7_rgba(mode7_block, pPixels, x1, y1, z1, w1, mean_r, mean_g, mean_b, mean_a, mode6_sse_est, flags, &mode7_sse_est);
			}
		}

		if ((mode45_sse_est < mode7_sse_est) && (mode45_sse_est < mode6_sse_est))
		{
			assert(mode45_valid_flag);
			memcpy(pBlock, mode45_block, sizeof(basist::bc7_block));
			return;
		}
		else if ((mode7_sse_est < mode45_sse_est) && (mode7_sse_est < mode6_sse_est))
		{
			assert(mode7_valid_flag);
			memcpy(pBlock, mode7_block, sizeof(basist::bc7_block));
			return;
		}

		// Fall back to mode 6
		int saxis_r = 256, saxis_g = 256, saxis_b = 256, saxis_a = 256;

		float k = basisu::maximum(fabsf(x1), fabsf(y1), fabsf(z1), fabsf(w1));
		if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
		{
			float m = 2048.0f / k;
			saxis_r = (int)(x1 * m);
			saxis_g = (int)(y1 * m);
			saxis_b = (int)(z1 * m);
			saxis_a = (int)(w1 * m);
		}

		saxis_r = (int)((uint32_t)saxis_r << 4U);
		saxis_g = (int)((uint32_t)saxis_g << 4U);
		saxis_b = (int)((uint32_t)saxis_b << 4U);
		saxis_a = (int)((uint32_t)saxis_a << 4U);

		int low_dot = INT_MAX, high_dot = INT_MIN;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			assert(((pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b + pPixels[i].a * saxis_a) & 0xF) == 0); // sanity
			assert(((pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b + pPixels[i + 1].a * saxis_a) & 0xF) == 0);
			assert(((pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b + pPixels[i + 2].a * saxis_a) & 0xF) == 0);
			assert(((pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b + pPixels[i + 3].a * saxis_a) & 0xF) == 0);

			const int dot0 = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b + pPixels[i].a * saxis_a) + i;
			const int dot1 = (pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b + pPixels[i + 1].a * saxis_a) + i + 1;
			const int dot2 = (pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b + pPixels[i + 2].a * saxis_a) + i + 2;
			const int dot3 = (pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b + pPixels[i + 3].a * saxis_a) + i + 3;

			int min_d01 = basisu::minimum(dot0, dot1);
			int max_d01 = basisu::maximum(dot0, dot1);

			int min_d23 = basisu::minimum(dot2, dot3);
			int max_d23 = basisu::maximum(dot2, dot3);

			int min_d = basisu::minimum(min_d01, min_d23);
			int max_d = basisu::maximum(max_d01, max_d23);

			low_dot = basisu::minimum(low_dot, min_d);
			high_dot = basisu::maximum(high_dot, max_d);
		}

		const int low_c = low_dot & 15;
		const int high_c = high_dot & 15;

		int p0, p1, lr, lg, lb, la, hr, hg, hb, ha;

		if (flags & cPackBC7FlagPBitOptMode6)
		{
			const float q = 1.0f / 255.0f;
			float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, (float)pPixels[low_c].a * q };
			float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, (float)pPixels[high_c].a * q };

			color_rgba bestMinColor, bestMaxColor;
			uint32_t best_pbits[2];
			determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

			p0 = best_pbits[0], p1 = best_pbits[1];
			lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b, la = bestMinColor.a;
			hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b, ha = bestMaxColor.a;
		}
		else
		{
			p0 = pPixels[low_c].a > 128;
			p1 = pPixels[high_c].a > 128;

			lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0), la = to_7(pPixels[low_c].a, p0);
			hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1), ha = to_7(pPixels[high_c].a, p1);
		}

		uint8_t cur_weights[16];
		eval_weights_mode6_rgba(pPixels, cur_weights,
			lr, lg, lb, la, p0,
			hr, hg, hb, ha, p1);

		vec4F xl, xh;
		bool res = compute_least_squares_endpoints_4D(
			16, cur_weights, 16,
			g_bc7_4bit_ls_tab,
			xl, xh,
			pPixels,
			(float)total_r, (float)total_g, (float)total_b, (float)total_a);

		if (res)
		{
			if (flags & cPackBC7FlagPBitOptMode6)
			{
				const float q = 1.0f / 255.0f;
				float sxl[4] = { xl[0] * q, xl[1] * q, xl[2] * q, xl[3] * q };
				float sxh[4] = { xh[0] * q, xh[1] * q, xh[2] * q, xh[3] * q };

				color_rgba bestMinColor, bestMaxColor;
				uint32_t best_pbits[2];
				determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

				p0 = best_pbits[0], p1 = best_pbits[1];
				lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b, la = bestMinColor.a;
				hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b, ha = bestMaxColor.a;
			}
			else
			{
				p0 = (xl[3] >= 129.0f);
				lr = to_7(xl[0], p0);
				lg = to_7(xl[1], p0);
				lb = to_7(xl[2], p0);
				la = to_7(xl[3], p0);

				p1 = (xh[3] >= 129.0f);
				hr = to_7(xh[0], p1);
				hg = to_7(xh[1], p1);
				hb = to_7(xh[2], p1);
				ha = to_7(xh[3], p1);
			}

			eval_weights_mode6_rgba(pPixels, cur_weights,
				lr, lg, lb, la, p0,
				hr, hg, hb, ha, p1);
		}

		encode_mode6_rgba_block(pBlock,
			lr, lg, lb, la, p0,
			hr, hg, hb, ha, p1,
			cur_weights);
	}

	uint32_t fast_pack_bc7_rgba_partial_analytical(uint8_t* pBlock, const color_rgba* pPixels, uint32_t flags)
	{
		assert(g_bc7_4bit_ls_tab[1][0]);

#if BASISU_BC7F_PERF_STATS
		g_total_rgba_calls++;
#endif

		const uint32_t fc = *(const uint32_t*)&pPixels[0];
		if (fc == *(const uint32_t*)&pPixels[15])
		{
			int k;
			for (k = 1; k < 15; k++)
				if (*(const uint32_t*)&pPixels[k] != fc)
					break;

			if (k == 15)
			{
				pack_mode5_solid(pBlock, pPixels[0]);
				return 0;
			}
		}

		int total_r = 0, total_g = 0, total_b = 0, total_a = 0;
		int min_r = 255, min_g = 255, min_b = 255, min_a = 255;
		int max_r = 0, max_g = 0, max_b = 0, max_a = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b, a = pPixels[i].a;

			total_r += r; total_g += g; total_b += b; total_a += a;

			min_r = basisu::minimum(min_r, r); min_g = basisu::minimum(min_g, g); min_b = basisu::minimum(min_b, b); min_a = basisu::minimum(min_a, a);
			max_r = basisu::maximum(max_r, r); max_g = basisu::maximum(max_g, g); max_b = basisu::maximum(max_b, b); max_a = basisu::maximum(max_a, a);
		}

		assert((min_r != max_r) || (min_g != max_g) || (min_b != max_b) || (min_a != max_a));

		const int mean_r = (total_r + 8) >> 4, mean_g = (total_g + 8) >> 4, mean_b = (total_b + 8) >> 4, mean_a = (total_a + 8) >> 4;

		// covar rows are:
		int icov4[10] = { };

		// 0=rr
		// 1=rg
		// 2=rb
		// 3=ra
		// 
		// 4=gg
		// 5=gb
		// 6=ga
		// 
		// 7=bb
		// 8=ba
		// 
		// 9=aa

		// 0 1 2 3
		//   4 5 6
		//     7 8
		//       9

		// 0 1 2 3
		// 1 4 5 6
		// 2 5 7 8
		// 3 6 8 9

		// trace at 0,4,7,9

		for (uint32_t i = 0; i < 16; i++)
		{
			const int r = (int)pPixels[i].r - mean_r, g = (int)pPixels[i].g - mean_g, b = (int)pPixels[i].b - mean_b, a = (int)pPixels[i].a - mean_a;

			icov4[0] += r * r; icov4[1] += r * g; icov4[2] += r * b; icov4[3] += r * a;
			icov4[4] += g * g; icov4[5] += g * b; icov4[6] += g * a;
			icov4[7] += b * b; icov4[8] += b * a;
			icov4[9] += a * a;
		}

		const int block_max_var4 = basisu::maximum(icov4[0], icov4[4], icov4[7], icov4[9]); // not divided by 16, i.e. scaled by 16
		assert(block_max_var4); // solid blocks already filtered out

		// check for dual plane, if a single component is very strongly decorrelated then switch to modes 4/5
		int desired_dp_chan = -1;

		const bool non_analytical_flag = (flags & cPackBC7FlagNonAnalyticalRGBA) != 0;
		if (non_analytical_flag)
		{
			assert(flags & cPackBC7FlagPartiallyAnalyticalRGBA);
		}

		if ((flags & cPackBC7FlagUseDualPlaneRGBA) &&
			((!non_analytical_flag && (block_max_var4 >= DP_BLOCK_VAR_THRESH_RGBA)) || (non_analytical_flag && (block_max_var4 > 16)))
			)
		{
			// Prefer A, if not strongly decorrelated then check RGB.
			const float r_var = (float)icov4[0], g_var = (float)icov4[4], b_var = (float)icov4[7], a_var = (float)icov4[9];

			const bool has_a = icov4[9] > 0;

			if (has_a)
			{
				const float p_03 = icov4[0] ? fabs((float)icov4[3] / sqrtf(r_var * a_var)) : 1.0f;
				const float p_13 = icov4[4] ? fabs((float)icov4[6] / sqrtf(g_var * a_var)) : 1.0f;
				const float p_23 = icov4[7] ? fabs((float)icov4[8] / sqrtf(b_var * a_var)) : 1.0f;

				const float min_p = basisu::minimum(p_03, p_13, p_23);
				if (min_p < ALPHA_DECORR_THRESHOLD)
				{
					desired_dp_chan = 3;
#if BASISU_BC7F_PERF_STATS
					g_total_dp_valid_chans_a++;
#endif
				}
			}

			if (desired_dp_chan < 0)
			{
				const bool has_r = icov4[0] > 16, has_g = icov4[4] > 16, has_b = icov4[7] > 16;
				const uint32_t total_active_chans_rgb = has_r + has_g + has_b;

				if (total_active_chans_rgb >= 2)
				{
					const float rg_corr = (has_r && has_g) ? fabs((float)icov4[1] / sqrtf(r_var * g_var)) : 1.0f;
					const float rb_corr = (has_r && has_b) ? fabs((float)icov4[2] / sqrtf(r_var * b_var)) : 1.0f;
					const float gb_corr = (has_g && has_b) ? fabs((float)icov4[5] / sqrtf(g_var * b_var)) : 1.0f;

					float min_p = basisu::minimum(rg_corr, rb_corr, gb_corr);

					const float decorr_thresh = non_analytical_flag ? .999f : STRONG_DECORR_THRESH_RGBA;
					if (min_p < decorr_thresh)
					{
						if (total_active_chans_rgb == 2)
						{
							if (!has_r)
								desired_dp_chan = 1;
							else if (!has_g)
								desired_dp_chan = 0;
							else
								desired_dp_chan = 0;
						}
						else
						{
							// see if rg/rb is weakly correlated vs. gb
							if ((rg_corr < gb_corr) && (rb_corr < gb_corr))
								desired_dp_chan = 0;
							// see if gr/gb is weakly correlated vs. rb
							else if ((rg_corr < rb_corr) && (gb_corr < rb_corr))
								desired_dp_chan = 1;
							// assume b is weakest
							else
								desired_dp_chan = 2;
						}
#if BASISU_BC7F_PERF_STATS
						g_total_dp_valid_chans_rgb++;
#endif
					}
				}
			}
		}

		if ((flags & cPackBC7FlagUseTrivialMode6) && ((desired_dp_chan == -1) && (block_max_var4 < TRIVIAL_BLOCK_THRESH_RGBA)))
		{
			int low_c = INT_MAX, high_c = 0;

			for (uint32_t i = 0; i < 16; i++)
			{
				int y = ((16 * 2) * pPixels[i].r + (16 * 4) * pPixels[i].g + 16 * pPixels[i].b + (16 * 4) * pPixels[i].a);
				assert((y & 0xF) == 0);
				y += i;
				low_c = basisu::minimum(low_c, y);
				high_c = basisu::maximum(high_c, y);
			}

			low_c &= 0xF;
			high_c &= 0xF;

			int p0, p1, lr, lg, lb, la, hr, hg, hb, ha;

			if (flags & cPackBC7FlagPBitOptMode6)
			{
				const float q = 1.0f / 255.0f;
				float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, (float)pPixels[low_c].a * q };
				float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, (float)pPixels[high_c].a * q };

				color_rgba bestMinColor, bestMaxColor;
				uint32_t best_pbits[2];
				determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

				p0 = best_pbits[0], p1 = best_pbits[1];
				lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b, la = bestMinColor.a;
				hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b, ha = bestMaxColor.a;
			}
			else
			{
				p0 = pPixels[low_c].a > 128;
				p1 = pPixels[high_c].a > 128;

				lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0), la = to_7(pPixels[low_c].a, p0);
				hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1), ha = to_7(pPixels[high_c].a, p1);
			}

			uint8_t cur_weights[16];
			uint32_t mode6_actual_sse = eval_weights_mode6_rgba_sse(pPixels, cur_weights,
				lr, lg, lb, la, p0,
				hr, hg, hb, ha, p1);

			encode_mode6_rgba_block(pBlock,
				lr, lg, lb, la, p0,
				hr, hg, hb, ha, p1,
				cur_weights);

#if BASISU_BC7F_PERF_STATS
			g_total_trivial_mode6_blocks++;
#endif

#ifdef _DEBUG
			{
				// Final sanity checking.
				uint32_t expected_actual_sse = calc_sse(pBlock, pPixels);
				assert(expected_actual_sse == mode6_actual_sse);
			}
#endif

			return mode6_actual_sse;
		}

		float cov4[10];
		for (uint32_t i = 0; i < 10; i++)
			cov4[i] = (float)icov4[i];

		// all channel pairs:
		// 0,1=1
		// 0,2=2
		// 0,3=3
		// 1,2=5
		// 1,3=6
		// 2,3=8
		//const float r_var = cov4[0], g_var = cov4[4], b_var = cov4[7], a_var = cov4[9];

		const float sc4 = block_max_var4 ? (1.0f / (float)block_max_var4) : 0;
		float wx = sc4 * cov4[0], wy = sc4 * cov4[4], wz = sc4 * cov4[7], wa = sc4 * cov4[9];

		// 0 1 2 3
		// 1 4 5 6
		// 2 5 7 8
		// 3 6 8 9

		// TODO
		float x1, y1, z1, w1;
		for (uint32_t i = 0; i < 4; i++)
		{
			x1 = cov4[0] * wx + cov4[1] * wy + cov4[2] * wz + cov4[3] * wa;
			y1 = cov4[1] * wx + cov4[4] * wy + cov4[5] * wz + cov4[6] * wa;
			z1 = cov4[2] * wx + cov4[5] * wy + cov4[7] * wz + cov4[8] * wa;
			w1 = cov4[3] * wx + cov4[6] * wy + cov4[8] * wz + cov4[9] * wa;

			float t = sqrtf(x1 * x1 + y1 * y1 + z1 * z1 + w1 * w1);
			if (t > basisu::SMALL_FLOAT_VAL)
			{
				t = 1.0f / t;
				x1 *= t; y1 *= t; z1 *= t; w1 *= t;
			}
			else
			{
				x1 = y1 = z1 = w1 = .25f;
			}

			wx = x1; wy = y1; wz = z1; wa = w1;
		}

		// Fall back to mode 6
		int saxis_r = 256, saxis_g = 256, saxis_b = 256, saxis_a = 256;

		float k = basisu::maximum(fabsf(x1), fabsf(y1), fabsf(z1), fabsf(w1));
		if (fabs(k) >= basisu::SMALL_FLOAT_VAL)
		{
			float m = 2048.0f / k;
			saxis_r = (int)(x1 * m);
			saxis_g = (int)(y1 * m);
			saxis_b = (int)(z1 * m);
			saxis_a = (int)(w1 * m);
		}

		saxis_r = (int)((uint32_t)saxis_r << 4U);
		saxis_g = (int)((uint32_t)saxis_g << 4U);
		saxis_b = (int)((uint32_t)saxis_b << 4U);
		saxis_a = (int)((uint32_t)saxis_a << 4U);

		int low_dot = INT_MAX, high_dot = INT_MIN;

		for (uint32_t i = 0; i < 16; i += 4)
		{
			assert(((pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b + pPixels[i].a * saxis_a) & 0xF) == 0); // sanity
			assert(((pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b + pPixels[i + 1].a * saxis_a) & 0xF) == 0);
			assert(((pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b + pPixels[i + 2].a * saxis_a) & 0xF) == 0);
			assert(((pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b + pPixels[i + 3].a * saxis_a) & 0xF) == 0);

			const int dot0 = (pPixels[i].r * saxis_r + pPixels[i].g * saxis_g + pPixels[i].b * saxis_b + pPixels[i].a * saxis_a) + i;
			const int dot1 = (pPixels[i + 1].r * saxis_r + pPixels[i + 1].g * saxis_g + pPixels[i + 1].b * saxis_b + pPixels[i + 1].a * saxis_a) + i + 1;
			const int dot2 = (pPixels[i + 2].r * saxis_r + pPixels[i + 2].g * saxis_g + pPixels[i + 2].b * saxis_b + pPixels[i + 2].a * saxis_a) + i + 2;
			const int dot3 = (pPixels[i + 3].r * saxis_r + pPixels[i + 3].g * saxis_g + pPixels[i + 3].b * saxis_b + pPixels[i + 3].a * saxis_a) + i + 3;

			int min_d01 = basisu::minimum(dot0, dot1);
			int max_d01 = basisu::maximum(dot0, dot1);

			int min_d23 = basisu::minimum(dot2, dot3);
			int max_d23 = basisu::maximum(dot2, dot3);

			int min_d = basisu::minimum(min_d01, min_d23);
			int max_d = basisu::maximum(max_d01, max_d23);

			low_dot = basisu::minimum(low_dot, min_d);
			high_dot = basisu::maximum(high_dot, max_d);
		}

		const int low_c = low_dot & 15;
		const int high_c = high_dot & 15;

		int p0, p1, lr, lg, lb, la, hr, hg, hb, ha;

		if (flags & cPackBC7FlagPBitOptMode6)
		{
			const float q = 1.0f / 255.0f;
			float sxl[4] = { (float)pPixels[low_c].r * q, (float)pPixels[low_c].g * q, (float)pPixels[low_c].b * q, (float)pPixels[low_c].a * q };
			float sxh[4] = { (float)pPixels[high_c].r * q, (float)pPixels[high_c].g * q, (float)pPixels[high_c].b * q, (float)pPixels[high_c].a * q };

			color_rgba bestMinColor, bestMaxColor;
			uint32_t best_pbits[2];
			determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

			p0 = best_pbits[0], p1 = best_pbits[1];
			lr = bestMinColor.r, lg = bestMinColor.g, lb = bestMinColor.b, la = bestMinColor.a;
			hr = bestMaxColor.r, hg = bestMaxColor.g, hb = bestMaxColor.b, ha = bestMaxColor.a;
		}
		else
		{
			p0 = pPixels[low_c].a > 128;
			p1 = pPixels[high_c].a > 128;

			lr = to_7(pPixels[low_c].r, p0), lg = to_7(pPixels[low_c].g, p0), lb = to_7(pPixels[low_c].b, p0), la = to_7(pPixels[low_c].a, p0);
			hr = to_7(pPixels[high_c].r, p1), hg = to_7(pPixels[high_c].g, p1), hb = to_7(pPixels[high_c].b, p1), ha = to_7(pPixels[high_c].a, p1);
		}

		uint8_t cur_weights[16];
		uint32_t mode6_actual_sse = eval_weights_mode6_rgba_sse(pPixels, cur_weights,
			lr, lg, lb, la, p0,
			hr, hg, hb, ha, p1);

		if (mode6_actual_sse)
		{
			vec4F xl, xh;
			bool res = compute_least_squares_endpoints_4D(
				16, cur_weights, 16,
				g_bc7_4bit_ls_tab,
				xl, xh,
				pPixels,
				(float)total_r, (float)total_g, (float)total_b, (float)total_a);

			if (res)
			{
				int trial_p0, trial_p1, trial_lr, trial_lg, trial_lb, trial_la, trial_hr, trial_hg, trial_hb, trial_ha;

				if (flags & cPackBC7FlagPBitOptMode6)
				{
					const float q = 1.0f / 255.0f;
					float sxl[4] = { xl[0] * q, xl[1] * q, xl[2] * q, xl[3] * q };
					float sxh[4] = { xh[0] * q, xh[1] * q, xh[2] * q, xh[3] * q };

					color_rgba bestMinColor, bestMaxColor;
					uint32_t best_pbits[2];
					determine_unique_pbits(4, 7, sxl, sxh, bestMinColor, bestMaxColor, best_pbits);

					trial_p0 = best_pbits[0], trial_p1 = best_pbits[1];
					trial_lr = bestMinColor.r, trial_lg = bestMinColor.g, trial_lb = bestMinColor.b, trial_la = bestMinColor.a;
					trial_hr = bestMaxColor.r, trial_hg = bestMaxColor.g, trial_hb = bestMaxColor.b, trial_ha = bestMaxColor.a;
				}
				else
				{
					trial_p0 = (xl[3] >= 129.0f);
					trial_lr = to_7(xl[0], trial_p0);
					trial_lg = to_7(xl[1], trial_p0);
					trial_lb = to_7(xl[2], trial_p0);
					trial_la = to_7(xl[3], trial_p0);

					trial_p1 = (xh[3] >= 129.0f);
					trial_hr = to_7(xh[0], trial_p1);
					trial_hg = to_7(xh[1], trial_p1);
					trial_hb = to_7(xh[2], trial_p1);
					trial_ha = to_7(xh[3], trial_p1);
				}

				uint8_t trial_weights[16];
				uint32_t mode6_ls_actual_sse = eval_weights_mode6_rgba_sse(pPixels, trial_weights,
					trial_lr, trial_lg, trial_lb, trial_la, trial_p0,
					trial_hr, trial_hg, trial_hb, trial_ha, trial_p1);

				if (mode6_ls_actual_sse < mode6_actual_sse)
				{
					mode6_actual_sse = mode6_ls_actual_sse;
					memcpy(cur_weights, trial_weights, 16);
					p0 = trial_p0; p1 = trial_p1;
					lr = trial_lr; lg = trial_lg; lb = trial_lb; la = trial_la;
					hr = trial_hr; hg = trial_hg; hb = trial_hb; ha = trial_ha;
				}
			}
		}

		uint32_t mode7_actual_sse = UINT32_MAX;
		uint8_t mode7_candidate_block[sizeof(basist::bc7_block)];

		uint32_t mode45_actual_sse = UINT32_MAX;
		uint8_t mode45_candidate_block[sizeof(basist::bc7_block)];

		if (mode6_actual_sse)
		{
			if (non_analytical_flag)
			{
				// No gates: very expensive.
				if (flags & cPackBC7FlagUse2SubsetsRGBA)
				{
					pack_mode7_rgba(mode7_candidate_block, pPixels, x1, y1, z1, w1, mean_r, mean_g, mean_b, mean_a, 1e+9f, flags, nullptr, &mode7_actual_sse);
				}

				if (flags & cPackBC7FlagUseDualPlaneRGBA)
					pack_mode4_or_5(mode45_candidate_block, pPixels, (desired_dp_chan >= 0) ? desired_dp_chan : 3, 1e+9f, flags, nullptr, &mode45_actual_sse); // todo: determine best def channel here
			}
			else
			{
				float mode6_ortho_ratio;
				const float mode6_slam_to_line_sse_est = estimate_slam_to_line_sse_4D(cov4, x1, y1, z1, w1, &mode6_ortho_ratio);

				if ((flags & cPackBC7FlagUse2SubsetsRGBA) && (block_max_var4 >= MIN_BLOCK_MAX_VAR_23SUBSETS_RGBA) && (mode6_ortho_ratio > ORTHO_RATIO_23SUBSET_RATIO_THRESH_RGBA))
				{
					const bool high_ortho_energy_flag = (mode6_slam_to_line_sse_est >= HIGH_ORTHO_ENERGY_THRESH_RGBA);

					if (high_ortho_energy_flag)
					{
#if BASISU_BC7F_PERF_STATS
						g_total_high_ortho_energy++;
#endif
						pack_mode7_rgba(mode7_candidate_block, pPixels, x1, y1, z1, w1, mean_r, mean_g, mean_b, mean_a, 1e+9f, flags, nullptr, &mode7_actual_sse);
					}
				}

				if (desired_dp_chan >= 0)
					pack_mode4_or_5(mode45_candidate_block, pPixels, desired_dp_chan, 1e+9f, flags, nullptr, &mode45_actual_sse);
			}
		}

		const uint32_t best_actual_sse = basisu::minimum(mode6_actual_sse, mode45_actual_sse, mode7_actual_sse);

		if ((mode45_actual_sse != UINT32_MAX) && (best_actual_sse == mode45_actual_sse))
		{
			memcpy(pBlock, mode45_candidate_block, sizeof(basist::bc7_block));
		}
		else if ((mode7_actual_sse != UINT32_MAX) && (best_actual_sse == mode7_actual_sse))
		{
			memcpy(pBlock, mode7_candidate_block, sizeof(basist::bc7_block));
		}
		else
		{
			assert(mode6_actual_sse == best_actual_sse);

			encode_mode6_rgba_block(pBlock,
				lr, lg, lb, la, p0,
				hr, hg, hb, ha, p1,
				cur_weights);
		}

#ifdef _DEBUG
		{
			// Final sanity checking.
			uint32_t expected_actual_sse = calc_sse(pBlock, pPixels);
			assert(expected_actual_sse == best_actual_sse);
		}
#endif

		return best_actual_sse;
	}

	// Routes to either rgb or rgba automatically
	uint32_t fast_pack_bc7_auto_rgba(uint8_t* pBlock, const color_rgba* pPixels, uint32_t flags)
	{
		for (uint32_t i = 0; i < 16; i += 4)
		{
			if ((pPixels[i].a < 255) || (pPixels[i + 1].a < 255) || (pPixels[i + 2].a < 255) || (pPixels[i + 3].a < 255))
			{
				if (flags & cPackBC7FlagPartiallyAnalyticalRGBA)
					return bc7f::fast_pack_bc7_rgba_partial_analytical(pBlock, pPixels, flags);
				else
				{
					bc7f::fast_pack_bc7_rgba_analytical(pBlock, pPixels, flags);
					return 0;
				}
			}
		}

		if (flags & cPackBC7FlagPartiallyAnalyticalRGB)
			return bc7f::fast_pack_bc7_rgb_partial_analytical(pBlock, pPixels, flags);
		else
		{
			bc7f::fast_pack_bc7_rgb_analytical(pBlock, pPixels, flags);
			return 0;
		}
	}

	// Source block cannot have alpha.
	uint32_t fast_pack_bc7_auto_rgb(uint8_t* pBlock, const color_rgba* pPixels, uint32_t flags)
	{
// Disabling this check here, because during fuzzing the ktx2 file may lie. In this case it's harmless to output an opaque block.
#if 0
#if defined(DEBUG) || defined(_DEBUG)
		for (uint32_t i = 0; i < 16; i += 4)
		{
			if ((pPixels[i].a < 255) || (pPixels[i + 1].a < 255) || (pPixels[i + 2].a < 255) || (pPixels[i + 3].a < 255))
			{
				// Block can't have alpha here, or the solid color detectors may misfire.
				assert(0);
			}
		}
#endif
#endif

		if (flags & cPackBC7FlagPartiallyAnalyticalRGB)
			return bc7f::fast_pack_bc7_rgb_partial_analytical(pBlock, pPixels, flags);
		else
		{
			bc7f::fast_pack_bc7_rgb_analytical(pBlock, pPixels, flags);
			return 0;
		}
	}

	void clear_perf_stats()
	{
#if BASISU_BC7F_PERF_STATS
#define BU_CLEAR_BLOCK_STAT(x) x = 0;
		BU_CLEAR_BLOCK_STAT(g_total_rgb_calls);
		BU_CLEAR_BLOCK_STAT(g_total_rgba_calls);
		BU_CLEAR_BLOCK_STAT(g_total_solid_blocks);
		BU_CLEAR_BLOCK_STAT(g_total_trivial_mode6_blocks);
		BU_CLEAR_BLOCK_STAT(g_total_dp_valid_chans_rgb);
		BU_CLEAR_BLOCK_STAT(g_total_dp_valid_chans_a);
		BU_CLEAR_BLOCK_STAT(g_total_high_ortho_energy);
		BU_CLEAR_BLOCK_STAT(g_total_mode02_evals);
		BU_CLEAR_BLOCK_STAT(g_total_mode02_bailouts);
		BU_CLEAR_BLOCK_STAT(g_total_mode13_evals);
		BU_CLEAR_BLOCK_STAT(g_total_mode13_bailouts);
		BU_CLEAR_BLOCK_STAT(g_total_mode45_evals);
		BU_CLEAR_BLOCK_STAT(g_total_mode45_bailouts);
		BU_CLEAR_BLOCK_STAT(g_total_mode7_evals);
		BU_CLEAR_BLOCK_STAT(g_total_mode7_bailouts);
#undef BU_CLEAR_BLOCK_STAT
#endif
	}

	void print_perf_stats()
	{
#if BASISU_BC7F_PERF_STATS
		const uint32_t total_bc7_blocks = g_total_rgb_calls + g_total_rgba_calls;
		if (!total_bc7_blocks)
			return;

#define BU_PRINT_BLOCK_STAT(x) printf(#x ": %u %3.2f%%\n", (uint32_t)x, static_cast<float>(x) * 100.0f / (float)total_bc7_blocks);
		BU_PRINT_BLOCK_STAT(g_total_rgb_calls);
		BU_PRINT_BLOCK_STAT(g_total_rgba_calls);
		BU_PRINT_BLOCK_STAT(g_total_solid_blocks);
		BU_PRINT_BLOCK_STAT(g_total_trivial_mode6_blocks);
		BU_PRINT_BLOCK_STAT(g_total_dp_valid_chans_rgb);
		BU_PRINT_BLOCK_STAT(g_total_dp_valid_chans_a);
		BU_PRINT_BLOCK_STAT(g_total_high_ortho_energy);
		BU_PRINT_BLOCK_STAT(g_total_mode02_evals);
		BU_PRINT_BLOCK_STAT(g_total_mode02_bailouts);
		BU_PRINT_BLOCK_STAT(g_total_mode13_evals);
		BU_PRINT_BLOCK_STAT(g_total_mode13_bailouts);
		BU_PRINT_BLOCK_STAT(g_total_mode45_evals);
		BU_PRINT_BLOCK_STAT(g_total_mode45_bailouts);
		BU_PRINT_BLOCK_STAT(g_total_mode7_evals);
		BU_PRINT_BLOCK_STAT(g_total_mode7_bailouts);
#undef BU_PRINT_BLOCK_STAT

#endif
	}

	struct bc7_mode_6
	{
		struct
		{
			uint64_t m_mode : 7;
			uint64_t m_r0 : 7;
			uint64_t m_r1 : 7;
			uint64_t m_g0 : 7;
			uint64_t m_g1 : 7;
			uint64_t m_b0 : 7;
			uint64_t m_b1 : 7;
			uint64_t m_a0 : 7;
			uint64_t m_a1 : 7;
			uint64_t m_p0 : 1;
		} m_lo;

		union
		{
			struct
			{
				uint64_t m_p1 : 1;
				uint64_t m_s00 : 3;
				uint64_t m_s10 : 4;
				uint64_t m_s20 : 4;
				uint64_t m_s30 : 4;

				uint64_t m_s01 : 4;
				uint64_t m_s11 : 4;
				uint64_t m_s21 : 4;
				uint64_t m_s31 : 4;

				uint64_t m_s02 : 4;
				uint64_t m_s12 : 4;
				uint64_t m_s22 : 4;
				uint64_t m_s32 : 4;

				uint64_t m_s03 : 4;
				uint64_t m_s13 : 4;
				uint64_t m_s23 : 4;
				uint64_t m_s33 : 4;

			} m_hi;

			uint64_t m_hi_bits;
		};
	};

	enum astc_weight_grid_2d
	{
		ASTC_WEIGHT_GRID_4X4 = 0,
		ASTC_WEIGHT_GRID_4X3 = 1,
		ASTC_WEIGHT_GRID_3X4 = 2
	};

	static inline uint32_t eval_line_sse_3tap_avg(const uint8_t* pLine4)
	{
		// Downsample 4 -> 3 using exact anchors and averaged center.
		const int c0 = pLine4[0];
		const int c1 = (pLine4[1] + pLine4[2] + 1) >> 1;
		const int c2 = pLine4[3];

		// ASTC 4x3/3x4 infill coefficients:
		// p0 = c0
		// p1 = (5*c0 + 11*c1 + 8) >> 4
		// p2 = (11*c1 + 5*c2 + 8) >> 4
		// p3 = c2
		//
		// Only p1/p2 can differ from the source, so only score those.
		const int p1 = (5 * c0 + 11 * c1 + 8) >> 4;
		const int p2 = (11 * c1 + 5 * c2 + 8) >> 4;

		const int d1 = p1 - pLine4[1];
		const int d2 = p2 - pLine4[2];

		return (uint32_t)(d1 * d1 + d2 * d2);
	}

	static inline uint32_t eval_block_sse_as_4x3(const uint8_t* pWeights16)
	{
		uint32_t err = 0;

		// Evaluate 4 columns.
		for (int x = 0; x < 4; ++x)
		{
			uint8_t col[4];
			col[0] = pWeights16[x + 0];
			col[1] = pWeights16[x + 4];
			col[2] = pWeights16[x + 8];
			col[3] = pWeights16[x + 12];

			err += eval_line_sse_3tap_avg(col);
		}

		return err;
	}

	static inline uint32_t eval_block_sse_as_3x4(const uint8_t* pWeights16)
	{
		uint32_t err = 0;

		// Evaluate 4 rows.
		for (int y = 0; y < 4; ++y)
			err += eval_line_sse_3tap_avg(pWeights16 + (y << 2));

		return err;
	}

	// max_weight is included because you wanted the caller to specify 2-bit/3-bit/4-bit weights.
	// This version doesn't need it mathematically, but it keeps the API aligned with your use case.
	static inline astc_weight_grid_2d choose_astc_weight_grid_4x4_block(
		const uint8_t* pWeights16,
		uint32_t max_interior_sse)
	{
		const uint32_t err_4x3 = eval_block_sse_as_4x3(pWeights16);
		const uint32_t err_3x4 = eval_block_sse_as_3x4(pWeights16);

		const bool ok_4x3 = (err_4x3 <= max_interior_sse);
		const bool ok_3x4 = (err_3x4 <= max_interior_sse);

		if (ok_4x3 && ok_3x4)
			return (err_4x3 <= err_3x4) ? ASTC_WEIGHT_GRID_4X3 : ASTC_WEIGHT_GRID_3X4;

		if (ok_4x3)
			return ASTC_WEIGHT_GRID_4X3;

		if (ok_3x4)
			return ASTC_WEIGHT_GRID_3X4;

		return ASTC_WEIGHT_GRID_4X4;
	}

	static inline void bc7_weights_4x4_to_4x3_avg_u(const uint8_t* s, uint8_t* d, uint8_t inv_w)
	{
		// Row 0
		d[0] = s[0] ^ inv_w; d[1] = s[1] ^ inv_w; d[2] = s[2] ^ inv_w; d[3] = s[3] ^ inv_w;

		// Row 1 (avg rows 1+2)
		d[4] = ((s[4] + s[8] + 1) >> 1) ^ inv_w;
		d[5] = ((s[5] + s[9] + 1) >> 1) ^ inv_w;
		d[6] = ((s[6] + s[10] + 1) >> 1) ^ inv_w;
		d[7] = ((s[7] + s[11] + 1) >> 1) ^ inv_w;

		// Row 2
		d[8] = s[12] ^ inv_w; d[9] = s[13] ^ inv_w;
		d[10] = s[14] ^ inv_w; d[11] = s[15] ^ inv_w;
	}

	static inline void bc7_weights_4x4_to_3x4_avg_u(const uint8_t* s, uint8_t* d, uint8_t inv_w)
	{
		// Row 0
		d[0] = s[0] ^ inv_w;
		d[1] = ((s[1] + s[2] + 1) >> 1) ^ inv_w;
		d[2] = s[3] ^ inv_w;

		// Row 1
		d[3] = s[4] ^ inv_w;
		d[4] = ((s[5] + s[6] + 1) >> 1) ^ inv_w;
		d[5] = s[7] ^ inv_w;

		// Row 2
		d[6] = s[8] ^ inv_w;
		d[7] = ((s[9] + s[10] + 1) >> 1) ^ inv_w;
		d[8] = s[11] ^ inv_w;

		// Row 3
		d[9] = s[12] ^ inv_w;
		d[10] = ((s[13] + s[14] + 1) >> 1) ^ inv_w;
		d[11] = s[15] ^ inv_w;
	}

	static const int16_t s_bc7_2subsets_to_common_pattern[53] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, -1, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, 26, -1, -1, 27, 28, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 29 };

	static void set_solid(astc_helpers::log_astc_block& log_blk, uint32_t r, uint32_t g, uint32_t b, uint32_t a)
	{
		log_blk.m_solid_color_flag_ldr = true;
		log_blk.m_solid_color[0] = (uint16_t)(r | ((uint32_t)r << 8));
		log_blk.m_solid_color[1] = (uint16_t)(g | ((uint32_t)g << 8));
		log_blk.m_solid_color[2] = (uint16_t)(b | ((uint32_t)b << 8));
		log_blk.m_solid_color[3] = (uint16_t)(a | ((uint32_t)a << 8));
	}

	// returns true if the weights must be inverted
	static bool cem_encode_bc(uint32_t cem, uint8_t* pDst, const color_rgba* pSrc, uint32_t endpoint_ise_range, const basisu::uint8_vec& endpoint_to_ise, const basisu::uint8_vec& endpoint_from_ise)
	{
		assert((cem == 8) || (cem == 12));
		BASISU_NOTE_UNUSED(endpoint_ise_range);
		assert(endpoint_ise_range < astc_helpers::BISE_256_LEVELS); // no point using BC on 256 levels

		color_rgba l(pSrc[0]);
		int enc_lb = endpoint_from_ise[endpoint_to_ise[pSrc[0].b]];

		color_rgba h(pSrc[1]);
		int enc_hb = endpoint_from_ise[endpoint_to_ise[pSrc[1].b]];

		bool did_clamp = false;
		color_rgba enc_l(astc_ldr_t::blue_contract_enc(l, did_clamp, enc_lb));
		color_rgba enc_h(astc_ldr_t::blue_contract_enc(h, did_clamp, enc_hb));

		bool desired_bc = true;
		if (did_clamp)
		{
			desired_bc = false;

			enc_l = l;
			enc_h = h;
		}

		pDst[0] = endpoint_to_ise[enc_l.r];
		pDst[1] = endpoint_to_ise[enc_h.r];
		pDst[2] = endpoint_to_ise[enc_l.g];
		pDst[3] = endpoint_to_ise[enc_h.g];
		pDst[4] = endpoint_to_ise[enc_l.b];
		pDst[5] = endpoint_to_ise[enc_h.b];

		if (cem == 12)
		{
			pDst[6] = endpoint_to_ise[enc_l.a];
			pDst[7] = endpoint_to_ise[enc_h.a];
		}

		uint32_t rgb_sums[2];
		rgb_sums[0] = endpoint_from_ise[pDst[0]] + endpoint_from_ise[pDst[2]] + endpoint_from_ise[pDst[4]];
		rgb_sums[1] = endpoint_from_ise[pDst[1]] + endpoint_from_ise[pDst[3]] + endpoint_from_ise[pDst[5]];

		bool invert_weights = false;

		const bool actual_bc = rgb_sums[1] < rgb_sums[0];

		if (actual_bc != desired_bc)
		{
			if ((desired_bc) && (rgb_sums[0] == rgb_sums[1]))
			{
				// just disable BC, swapping will make no difference
				pDst[0] = endpoint_to_ise[l.r];
				pDst[1] = endpoint_to_ise[h.r];
				pDst[2] = endpoint_to_ise[l.g];
				pDst[3] = endpoint_to_ise[h.g];
				pDst[4] = endpoint_to_ise[l.b];
				pDst[5] = endpoint_to_ise[h.b];

				// recalc sums
				rgb_sums[0] = endpoint_from_ise[pDst[0]] + endpoint_from_ise[pDst[2]] + endpoint_from_ise[pDst[4]];
				rgb_sums[1] = endpoint_from_ise[pDst[1]] + endpoint_from_ise[pDst[3]] + endpoint_from_ise[pDst[5]];

				// ensure it's always not BC
				if (rgb_sums[1] < rgb_sums[0])
				{
					invert_weights = true;

					std::swap(pDst[0], pDst[1]);
					std::swap(pDst[2], pDst[3]);
					std::swap(pDst[4], pDst[5]);
					if (cem == 12)
						std::swap(pDst[6], pDst[7]);
				}

				desired_bc = false;
			}
			else
			{
				std::swap(pDst[0], pDst[1]);
				std::swap(pDst[2], pDst[3]);
				std::swap(pDst[4], pDst[5]);
				if (cem == 12)
					std::swap(pDst[6], pDst[7]);

				// if desired_bc=true there's a double endpoint swap here now, so no inversion
				if (!desired_bc)
					invert_weights = true;
			}
		}
		else
		{
			if (desired_bc)
				invert_weights = true;
		}

#if defined(DEBUG) || defined(_DEBUG)
		// make sure BC decode works as expected
		bool bc_check = astc_helpers::used_blue_contraction(cem, pDst, endpoint_ise_range);
		if (bc_check != desired_bc)
		{
			assert(0);
		}
#endif

		return invert_weights;
	}

	// returns true if the weights must be inverted
	static bool cem_encode_no_bc(uint32_t cem, uint8_t* pDst, const color_rgba* pSrc, uint32_t endpoint_ise_range, const basisu::uint8_vec& endpoint_to_ise, const basisu::uint8_vec& endpoint_from_ise)
	{
		assert((cem == 8) || (cem == 12));
		BASISU_NOTE_UNUSED(endpoint_ise_range);

		color_rgba l(pSrc[0]), h(pSrc[1]);

		const bool desired_bc = false;

		pDst[0] = endpoint_to_ise[l.r];
		pDst[1] = endpoint_to_ise[h.r];
		pDst[2] = endpoint_to_ise[l.g];
		pDst[3] = endpoint_to_ise[h.g];
		pDst[4] = endpoint_to_ise[l.b];
		pDst[5] = endpoint_to_ise[h.b];

		if (cem == 12)
		{
			pDst[6] = endpoint_to_ise[l.a];
			pDst[7] = endpoint_to_ise[h.a];
		}

		uint32_t rgb_sums[2];
		rgb_sums[0] = endpoint_from_ise[pDst[0]] + endpoint_from_ise[pDst[2]] + endpoint_from_ise[pDst[4]];
		rgb_sums[1] = endpoint_from_ise[pDst[1]] + endpoint_from_ise[pDst[3]] + endpoint_from_ise[pDst[5]];

		bool invert_weights = false;

		const bool actual_bc = rgb_sums[1] < rgb_sums[0];

		if (actual_bc != desired_bc)
		{
			std::swap(pDst[0], pDst[1]);
			std::swap(pDst[2], pDst[3]);
			std::swap(pDst[4], pDst[5]);
			if (cem == 12)
				std::swap(pDst[6], pDst[7]);
						
			invert_weights = true;
		}

#if defined(DEBUG) || defined(_DEBUG)
		// make sure BC decode works as expected
		bool bc_check = astc_helpers::used_blue_contraction(cem, pDst, endpoint_ise_range);
		if (bc_check != desired_bc)
		{
			assert(0);
		}
#endif

		return invert_weights;
	}

	// 4x4 block, 1-3 subsets, equal CEM's
	static void map_astc_block_weights_rgb(
		const color_rgba *pPixels,
		uint8_t *pWeights,
		astc_helpers::log_astc_block &log_blk,
		const basisu::uint8_vec& endpoint_from_ise)
	{
		const uint32_t num_subsets = log_blk.m_num_partitions;
		const uint32_t cem_index = log_blk.m_color_endpoint_modes[0];

		assert((num_subsets >= 1) && (num_subsets <= 3));
		
		int dr[3], dg[3], db[3], sofs[3];
		float f[3];

		const uint32_t num_vals_per_endpoint = astc_helpers::get_num_cem_values(cem_index);
		const uint32_t total_endpoint_vals = num_vals_per_endpoint * num_subsets;
		assert(total_endpoint_vals <= astc_helpers::MAX_ENDPOINT_VALS);

		uint8_t dequant_endpoints[astc_helpers::MAX_ENDPOINT_VALS];
		for (uint32_t i = 0; i < total_endpoint_vals; i++)
			dequant_endpoints[i] = endpoint_from_ise[log_blk.m_endpoints[i]];

		for (uint32_t s = 0; s < num_subsets; s++)
		{
			assert(log_blk.m_color_endpoint_modes[s] == cem_index);

			int de[4][2]; // [comp][endpoint]
			astc_helpers::decode_endpoint(cem_index, de, &dequant_endpoints[s * num_vals_per_endpoint]);

			dr[s] = de[0][1] - de[0][0];
			dg[s] = de[1][1] - de[1][0];
			db[s] = de[2][1] - de[2][0];

			f[s] = 64.0f / (float)(basisu::squarei(dr[s]) + basisu::squarei(dg[s]) + basisu::squarei(db[s]) + .00000125f);

			sofs[s] = -(de[0][0] * dr[s] + de[1][0] * dg[s] + de[2][0] * db[s]);
		}

		const uint8_t* pWeight_tab = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_val_to_ise.get_ptr();

		for (uint32_t i = 0; i < 16; i++)
		{
			uint32_t subset = astc_helpers::get_precomputed_texel_partition(4, 4, log_blk.m_partition_id, i & 3, i >> 2, num_subsets);

			const color_rgba& px = pPixels[i];

			int sel = (int)(float(px.r * dr[subset] + px.g * dg[subset] + px.b * db[subset] + sofs[subset]) * f[subset] + .5f);

			if (sel < 0)
				sel = 0;
			else if (sel > 64)
				sel = 64;

			pWeights[i] = (uint8_t)pWeight_tab[sel];
		}
	}
	
	// 3 subsets - endpoint quantization is brutal here. So we try pretty hard to exploit base+scale, base+ofs and blue contraction, making this the slowest set of modes. 
	// bc7f uses it rarely (only on the highest std dev blocks), so texture masking helps.
	static bool fast_pack_astc_3subsets(uint32_t mode, astc_helpers::log_astc_block& log_blk, const basist::bc7_block& bc7_block, const color_rgba* pPixels)
	{
		//log_blk.clear();
		//set_solid(log_blk, 0, 0, 255, 255);
		//return true;
		
		const uint32_t ENDPOINTS = 6;
		const uint32_t COMPS = 3;
		//const uint32_t WEIGHT_BITS = (mode == 0) ? 3 : 2;
		const uint32_t ENDPOINT_BITS = (mode == 0) ? 4 : 5;
		const uint32_t PBITS = (mode == 0) ? 6 : 0;
		//const uint32_t WEIGHT_VALS = 1 << WEIGHT_BITS;
		//const uint32_t WEIGHT_MASK = WEIGHT_VALS - 1;

		uint32_t bit_offset = mode + 1;
		const uint8_t* pBuf = reinterpret_cast<const uint8_t*>(&bc7_block);

		const uint32_t part = bc7u::read_bits32(pBuf, bit_offset, (mode == 0) ? 4 : 6);

		uint32_t r;
		for (r = 0; r < TOTAL_ASTC_BC7_COMMON_PARTITIONS3; r++)
			if (g_astc_bc7_common_partitions3[r].m_bc7 == part)
				break;

		if (r == TOTAL_ASTC_BC7_COMMON_PARTITIONS3)
		{
			log_blk.m_error_flag = true;
			return false;
		}

		log_blk.m_partition_id = g_astc_bc7_common_partitions3[r].m_astc;
		
		const uint32_t subset_perm_index = g_astc_bc7_common_partitions3[r].m_astc_to_bc7_perm; // g_astc_to_bc7_partition_index_perm_tables

		color_rgba endpoints[ENDPOINTS];
		for (uint32_t c = 0; c < COMPS; c++)
			for (uint32_t e = 0; e < ENDPOINTS; e++)
				endpoints[e][c] = (uint8_t)bc7u::read_bits32(pBuf, bit_offset, ENDPOINT_BITS);

		uint32_t pbits[6];
		for (uint32_t p = 0; p < PBITS; p++)
			pbits[p] = bc7u::read_bits32(pBuf, bit_offset, 1);

#if 0
		uint32_t weights[16];
		for (uint32_t i = 0; i < 16; i++)
			weights[i] = bc7u::read_bits32(pBuf, bit_offset, ((!i) || (i == basist::g_bc7_table_anchor_index_third_subset_1[part]) || (i == basist::g_bc7_table_anchor_index_third_subset_2[part])) ? (WEIGHT_BITS - 1) : WEIGHT_BITS);

		assert(bit_offset == 128);
#endif

		for (uint32_t e = 0; e < ENDPOINTS; e++)
			for (uint32_t c = 0; c < 4; c++)
				endpoints[e][c] = (uint8_t)((c == 3) ? 255 : (PBITS ? bc7u::bc7_dequant(endpoints[e][c], pbits[e], ENDPOINT_BITS) : bc7u::bc7_dequant(endpoints[e][c], ENDPOINT_BITS)));
				
		log_blk.m_num_partitions = 3;
						
		// first try base+scale, 3x4/4x3 or 4x4
		bool used_base_scale = true;

		log_blk.m_color_endpoint_modes[0] = astc_helpers::CEM_LDR_RGB_BASE_SCALE;
		log_blk.m_color_endpoint_modes[1] = astc_helpers::CEM_LDR_RGB_BASE_SCALE;
		log_blk.m_color_endpoint_modes[2] = astc_helpers::CEM_LDR_RGB_BASE_SCALE;

		for (uint32_t pass = 0; pass < 2; pass++)
		{
			if (pass == 0)
			{
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_32_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_8_LEVELS;
			}
			else
			{
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_40_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;
			}

			//const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
			const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;

			used_base_scale = true;

			for (uint32_t astc_subset = 0; astc_subset < 3; astc_subset++)
			{
				const uint32_t bc7_subset = g_astc_to_bc7_partition_index_perm_tables[subset_perm_index][astc_subset];

				uint8_t src_endpoints[6];
				cem_encode_no_bc(astc_helpers::CEM_LDR_RGB_DIRECT, src_endpoints, &endpoints[bc7_subset * 2], astc_helpers::BISE_256_LEVELS, 
					astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_val_to_ise,
					astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_ISE_to_val);

				bool bc_clamped = false, base_ofs_clamped = false;

				if (!astc_ldr_t::convert_endpoints_across_cems(
					astc_helpers::CEM_LDR_RGB_DIRECT, astc_helpers::BISE_256_LEVELS, src_endpoints,
					astc_helpers::CEM_LDR_RGB_BASE_SCALE, log_blk.m_endpoint_ise_range, &log_blk.m_endpoints[astc_subset * 4],
					true, false, true, bc_clamped, base_ofs_clamped))
				{
					used_base_scale = false;
					break;
				}

				const color_rgba* pL = &endpoints[bc7_subset * 2 + 0];
				const color_rgba* pH = &endpoints[bc7_subset * 2 + 1];
				const int sum_l = pL->r + pL->g + pL->b;
				const int sum_h = pH->r + pH->g + pH->b;
				if (sum_l > sum_h)
					pL = pH;

				uint8_t dequant_endpoints[4];
				for (uint32_t i = 0; i < 4; i++)
					dequant_endpoints[i] = endpoint_from_ise[log_blk.m_endpoints[astc_subset * 4 + i]];
								
				int de[4][2]; // [comp][endpoint]
				astc_helpers::decode_endpoint(astc_helpers::CEM_LDR_RGB_BASE_SCALE, de, dequant_endpoints);

				int dist2 = basisu::squarei(pL->r - de[0][0]) + basisu::squarei(pL->g - de[1][0]) + basisu::squarei(pL->b - de[2][0]);
				//if (dist2 > 64 * 3)
				if (dist2 > 256 * 3)
				{
					used_base_scale = false;
					break;
				}
			}

			if (!used_base_scale)
				break;

			uint8_t temp_weights[16];
			map_astc_block_weights_rgb(pPixels, pass ? log_blk.m_weights : temp_weights, log_blk, endpoint_from_ise);

			if (pass == 0)
			{
				// Now see if 3x4 or 4x3 is acceptable
				astc_weight_grid_2d grid_res = choose_astc_weight_grid_4x4_block(temp_weights, 6);

				if (grid_res >= ASTC_WEIGHT_GRID_4X3)
				{
					if (grid_res == ASTC_WEIGHT_GRID_3X4)
					{
						log_blk.m_grid_width = 3;
						bc7_weights_4x4_to_3x4_avg_u(temp_weights, log_blk.m_weights, 0);
						break;
					}
					else
					{
						assert(grid_res == ASTC_WEIGHT_GRID_4X3);
						log_blk.m_grid_height = 3;
						bc7_weights_4x4_to_4x3_avg_u(temp_weights, log_blk.m_weights, 0);
						break;
					}
				}
			}

		} // pass

		if (!used_base_scale)
		{
			uint8_t temp_weights[16];
			bool used_base_ofs = true;

			// try base+ofs 3x4 or 4x3
			{
				log_blk.m_color_endpoint_modes[0] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
				log_blk.m_color_endpoint_modes[1] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
				log_blk.m_color_endpoint_modes[2] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;

				log_blk.m_endpoint_ise_range = astc_helpers::BISE_16_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;

				//const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
				const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;

				for (uint32_t astc_subset = 0; astc_subset < 3; astc_subset++)
				{
					const uint32_t bc7_subset = g_astc_to_bc7_partition_index_perm_tables[subset_perm_index][astc_subset];

					uint8_t src_endpoints[6];
					cem_encode_no_bc(astc_helpers::CEM_LDR_RGB_DIRECT, src_endpoints, &endpoints[bc7_subset * 2], astc_helpers::BISE_256_LEVELS,
						astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_val_to_ise,
						astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_ISE_to_val);

					bool bc_clamped = false, base_ofs_clamped = false;

					if (!astc_ldr_t::convert_endpoints_across_cems(
						astc_helpers::CEM_LDR_RGB_DIRECT, astc_helpers::BISE_256_LEVELS, src_endpoints,
						astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET, log_blk.m_endpoint_ise_range, &log_blk.m_endpoints[astc_subset * 6],
						true, true, true, bc_clamped, base_ofs_clamped))
					{
						base_ofs_clamped = true;
					}

					if (base_ofs_clamped)
					{
						used_base_ofs = false;
						break;
					}
				}

				if (used_base_ofs)
				{
					map_astc_block_weights_rgb(pPixels, temp_weights, log_blk, endpoint_from_ise);
				}
			}

			if (!used_base_ofs)
			{
				// try rgb direct 3x4 or 4x3
				log_blk.m_color_endpoint_modes[0] = astc_helpers::CEM_LDR_RGB_DIRECT;
				log_blk.m_color_endpoint_modes[1] = astc_helpers::CEM_LDR_RGB_DIRECT;
				log_blk.m_color_endpoint_modes[2] = astc_helpers::CEM_LDR_RGB_DIRECT;

				log_blk.m_endpoint_ise_range = astc_helpers::BISE_16_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;

				const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
				const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
				//const auto& weight_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;

				for (uint32_t astc_subset = 0; astc_subset < 3; astc_subset++)
				{
					const uint32_t bc7_subset = g_astc_to_bc7_partition_index_perm_tables[subset_perm_index][astc_subset];

					cem_encode_bc(astc_helpers::CEM_LDR_RGB_DIRECT, &log_blk.m_endpoints[astc_subset * 6], &endpoints[bc7_subset * 2], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise);
				}

				map_astc_block_weights_rgb(pPixels, temp_weights, log_blk, endpoint_from_ise);
			}

			// Now see if 3x4 or 4x3 is acceptable
			astc_weight_grid_2d grid_res = choose_astc_weight_grid_4x4_block(temp_weights, 3);

			if (grid_res >= ASTC_WEIGHT_GRID_4X3)
			{
				if (grid_res == ASTC_WEIGHT_GRID_3X4)
				{
					log_blk.m_grid_width = 3;
					bc7_weights_4x4_to_3x4_avg_u(temp_weights, log_blk.m_weights, 0);
				}
				else
				{
					assert(grid_res == ASTC_WEIGHT_GRID_4X3);
					log_blk.m_grid_height = 3;
					bc7_weights_4x4_to_4x3_avg_u(temp_weights, log_blk.m_weights, 0);
				}
			}
			else
			{
				// use 4x4
				used_base_ofs = true;

				// try base+ofs
				{
					log_blk.m_color_endpoint_modes[0] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
					log_blk.m_color_endpoint_modes[1] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
					log_blk.m_color_endpoint_modes[2] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;

					log_blk.m_endpoint_ise_range = astc_helpers::BISE_12_LEVELS;
					log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;

					//const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
					const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;

					for (uint32_t astc_subset = 0; astc_subset < 3; astc_subset++)
					{
						const uint32_t bc7_subset = g_astc_to_bc7_partition_index_perm_tables[subset_perm_index][astc_subset];

						uint8_t src_endpoints[6];
						cem_encode_no_bc(astc_helpers::CEM_LDR_RGB_DIRECT, src_endpoints, &endpoints[bc7_subset * 2], astc_helpers::BISE_256_LEVELS,
							astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_val_to_ise,
							astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_ISE_to_val);

						bool bc_clamped = false, base_ofs_clamped = false;

						if (!astc_ldr_t::convert_endpoints_across_cems(
							astc_helpers::CEM_LDR_RGB_DIRECT, astc_helpers::BISE_256_LEVELS, src_endpoints,
							astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET, log_blk.m_endpoint_ise_range, &log_blk.m_endpoints[astc_subset * 6],
							true, true, true, bc_clamped, base_ofs_clamped))
						{
							base_ofs_clamped = true;
						}

						if (base_ofs_clamped)
						{
							used_base_ofs = false;
							break;
						}
					}

					if (used_base_ofs)
					{
						map_astc_block_weights_rgb(pPixels, log_blk.m_weights, log_blk, endpoint_from_ise);
					}
				}

				if (!used_base_ofs)
				{
					log_blk.m_color_endpoint_modes[0] = astc_helpers::CEM_LDR_RGB_DIRECT;
					log_blk.m_color_endpoint_modes[1] = astc_helpers::CEM_LDR_RGB_DIRECT;
					log_blk.m_color_endpoint_modes[2] = astc_helpers::CEM_LDR_RGB_DIRECT;

					log_blk.m_endpoint_ise_range = astc_helpers::BISE_12_LEVELS;
					log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;

					const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
					const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
					//const auto& weight_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;

					for (uint32_t astc_subset = 0; astc_subset < 3; astc_subset++)
					{
						const uint32_t bc7_subset = g_astc_to_bc7_partition_index_perm_tables[subset_perm_index][astc_subset];

						cem_encode_bc(astc_helpers::CEM_LDR_RGB_DIRECT, &log_blk.m_endpoints[astc_subset * 6], &endpoints[bc7_subset * 2], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise);
					}

					map_astc_block_weights_rgb(pPixels, log_blk.m_weights, log_blk, endpoint_from_ise);
				}
			}
		}

		return true;
	}
	
	static bool fast_pack_astc_2subsets(uint32_t mode, astc_helpers::log_astc_block& log_blk, const basist::bc7_block& bc7_block, const color_rgba* pPixels)
	{
		//log_blk.clear();
		//set_solid(log_blk, 255, 0, 255, 255);
		//return true;

		// 2 subsets
		//const uint32_t SUBSETS = 2;
		const uint32_t ENDPOINTS = 4;
		const uint32_t COMPS = (mode == 7) ? 4 : 3;
		const uint32_t WEIGHT_BITS = (mode == 1) ? 3 : 2;
		const uint32_t ENDPOINT_BITS = (mode == 7) ? 5 : ((mode == 1) ? 6 : 7);
		const uint32_t PBITS = (mode == 1) ? 2 : 4;
		const uint32_t SHARED_PBITS = (mode == 1) ? true : false;
		//const uint32_t WEIGHT_VALS = 1 << WEIGHT_BITS;
		//const uint32_t WEIGHT_MASK = WEIGHT_VALS - 1;

		uint32_t bit_offset = mode + 1;
		const uint8_t* pBuf = reinterpret_cast<const uint8_t*>(&bc7_block);

		const uint32_t part = bc7u::read_bits32(pBuf, bit_offset, 6);

		if (part >= 53)
		{
			log_blk.m_error_flag = true;
			return false;
		}

		int r = s_bc7_2subsets_to_common_pattern[part];
		if (r < 0)
		{
			log_blk.m_error_flag = true;
			return false;
		}

		log_blk.m_partition_id = g_astc_bc7_common_partitions2[r].m_astc;

		const bool invert_subsets_flag = g_astc_bc7_common_partitions2[r].m_invert;

		assert(g_astc_bc7_common_partitions2[r].m_bc7 == part);

		color_rgba endpoints[ENDPOINTS];
		for (uint32_t c = 0; c < COMPS; c++)
			for (uint32_t e = 0; e < ENDPOINTS; e++)
				endpoints[e][c] = (uint8_t)bc7u::read_bits32(pBuf, bit_offset, ENDPOINT_BITS);

		uint32_t pbits[4];
		for (uint32_t p = 0; p < PBITS; p++)
			pbits[p] = bc7u::read_bits32(pBuf, bit_offset, 1);

#if 0
		uint32_t weights[16];
		for (uint32_t i = 0; i < 16; i++)
			weights[i] = bc7u::read_bits32(pBuf, bit_offset, ((!i) || (i == basist::g_bc7_table_anchor_index_second_subset[part])) ? (WEIGHT_BITS - 1) : WEIGHT_BITS);

		assert(bit_offset == 128);
#endif

		for (uint32_t e = 0; e < ENDPOINTS; e++)
			for (uint32_t c = 0; c < 4; c++)
				endpoints[e][c] = (uint8_t)((c == ((mode == 7U) ? 4U : 3U)) ? 255 : bc7u::bc7_dequant(endpoints[e][c], pbits[SHARED_PBITS ? (e >> 1) : e], ENDPOINT_BITS));
		
		log_blk.m_num_partitions = 2;
		
		log_blk.m_color_endpoint_modes[0] = astc_helpers::CEM_LDR_RGB_DIRECT;
		log_blk.m_color_endpoint_modes[1] = astc_helpers::CEM_LDR_RGB_DIRECT;

		{
			if (WEIGHT_BITS == 2)
			{
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_64_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;
			}
			else
			{
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_32_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_8_LEVELS;
			}

			const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
			const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
				
			cem_encode_bc(astc_helpers::CEM_LDR_RGB_DIRECT, &log_blk.m_endpoints[0], &endpoints[0], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise);
			cem_encode_bc(astc_helpers::CEM_LDR_RGB_DIRECT, &log_blk.m_endpoints[6], &endpoints[2], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise);

			if (invert_subsets_flag)
			{
				for (uint32_t i = 0; i < 6; i++)
				{
					std::swap(log_blk.m_endpoints[i], log_blk.m_endpoints[i + 6]);
				}
			}

			uint8_t temp_weights[16];
			map_astc_block_weights_rgb(pPixels, temp_weights, log_blk, endpoint_from_ise);

			astc_weight_grid_2d grid_res = choose_astc_weight_grid_4x4_block(temp_weights, 4);

			if (grid_res >= ASTC_WEIGHT_GRID_4X3)
			{
				if (grid_res == ASTC_WEIGHT_GRID_3X4)
				{
					log_blk.m_grid_width = 3;
					bc7_weights_4x4_to_3x4_avg_u(temp_weights, log_blk.m_weights, 0);
				}
				else
				{
					assert(grid_res == ASTC_WEIGHT_GRID_4X3);
					log_blk.m_grid_height = 3;
					bc7_weights_4x4_to_4x3_avg_u(temp_weights, log_blk.m_weights, 0);
				}

				return true;
			}
		}

		// rgb direct
		if (WEIGHT_BITS == 2)
		{
			log_blk.m_endpoint_ise_range = astc_helpers::BISE_40_LEVELS;
			log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;
		}
		else
		{
			log_blk.m_endpoint_ise_range = astc_helpers::BISE_32_LEVELS;
			log_blk.m_weight_ise_range = astc_helpers::BISE_5_LEVELS;
		}

		const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
		const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
		//const auto& weight_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;
				
		// try base+ofs
		bool use_base_ofs = true;

		{
			for (uint32_t astc_subset = 0; astc_subset < 2; astc_subset++)
			{
				const uint32_t bc7_subset = astc_subset;

				uint8_t src_endpoints[6];
				cem_encode_no_bc(astc_helpers::CEM_LDR_RGB_DIRECT, src_endpoints, &endpoints[bc7_subset * 2], astc_helpers::BISE_256_LEVELS,
					astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_val_to_ise,
					astc_helpers::g_dequant_tables.get_endpoint_tab(astc_helpers::BISE_256_LEVELS).m_ISE_to_val);

				bool bc_clamped = false, base_ofs_clamped = false;

				if (!astc_ldr_t::convert_endpoints_across_cems(
					astc_helpers::CEM_LDR_RGB_DIRECT, astc_helpers::BISE_256_LEVELS, src_endpoints,
					astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET, log_blk.m_endpoint_ise_range, &log_blk.m_endpoints[astc_subset * 6],
					true, true, true, bc_clamped, base_ofs_clamped))
				{
					base_ofs_clamped = true;
				}

				if (base_ofs_clamped)
				{
					use_base_ofs = false;
					break;
				}
			}

			if (use_base_ofs)
			{
				log_blk.m_color_endpoint_modes[0] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
				log_blk.m_color_endpoint_modes[1] = astc_helpers::CEM_LDR_RGB_BASE_PLUS_OFFSET;
			}
		}

		if (!use_base_ofs)
		{
			assert(log_blk.m_color_endpoint_modes[0] == astc_helpers::CEM_LDR_RGB_DIRECT);
			assert(log_blk.m_color_endpoint_modes[1] == astc_helpers::CEM_LDR_RGB_DIRECT);

			cem_encode_bc(astc_helpers::CEM_LDR_RGB_DIRECT, &log_blk.m_endpoints[0], &endpoints[0], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise);
			cem_encode_bc(astc_helpers::CEM_LDR_RGB_DIRECT, &log_blk.m_endpoints[6], &endpoints[2], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise);
		}

		if (invert_subsets_flag)
		{
			for (uint32_t i = 0; i < 6; i++)
			{
				std::swap(log_blk.m_endpoints[i], log_blk.m_endpoints[i + 6]);
			}
		}

		map_astc_block_weights_rgb(pPixels, log_blk.m_weights, log_blk, endpoint_from_ise);

		return true;
	}
		
	// latent to latent transcode from BC7->ASTC LDR 4x4, when possible (some 2/3 subset cases could fail if the partition pattern is unsupported in ASTC)
	// pPixels may be nullptr, if so it'll unpack the BC7 block if needed to get the texels
	// returns false if something goes wrong unpacking OR if the BC7 block uses a pattern we can't losslessly map over to ASTC LDR 4x4, in which case we can repack entirely from scratch.
	bool fast_pack_astc(const basist::bc7_block& phys_bc7_block, astc_helpers::log_astc_block &log_blk, const color_rgba* pPixels) 
	{
		log_blk.clear();
		log_blk.m_grid_width = 4;
		log_blk.m_grid_height = 4;

		const int mode = bc7u::determine_bc7_mode(&phys_bc7_block);
		
		// TODO: Refactor to use bc7_log_blk - this was written before it existed.
		switch (mode)
		{
		case 7:
		{
			const uint32_t ENDPOINTS = 4;
			const uint32_t COMPS = 4;
			const uint32_t WEIGHT_BITS = 2;
			const uint32_t ENDPOINT_BITS = 5;
			const uint32_t PBITS = 4;
			//const uint32_t SHARED_PBITS = false;
			const uint32_t WEIGHT_VALS = 1 << WEIGHT_BITS;
			const uint32_t WEIGHT_MASK = WEIGHT_VALS - 1;

			uint32_t bit_offset = mode + 1;
			const uint8_t* pBuf = reinterpret_cast<const uint8_t*>(&phys_bc7_block);
						
			const uint32_t part = bc7u::read_bits32(pBuf, bit_offset, 6);

			if (part >= 53)
			{
				log_blk.m_error_flag = true;
				return false;
			}

			int r = s_bc7_2subsets_to_common_pattern[part];
			if (r < 0)
			{
				log_blk.m_error_flag = true;
				return false;
			}

			log_blk.m_partition_id = g_astc_bc7_common_partitions2[r].m_astc;

			const bool invert_subsets_flag = g_astc_bc7_common_partitions2[r].m_invert;

			assert(g_astc_bc7_common_partitions2[r].m_bc7 == part);

			color_rgba endpoints[ENDPOINTS];
			for (uint32_t c = 0; c < COMPS; c++)
				for (uint32_t e = 0; e < ENDPOINTS; e++)
					endpoints[e][c] = (uint8_t)bc7u::read_bits32(pBuf, bit_offset, ENDPOINT_BITS);

			uint32_t pbits[4];
			for (uint32_t p = 0; p < PBITS; p++)
				pbits[p] = bc7u::read_bits32(pBuf, bit_offset, 1);

			uint32_t weights[16];
			for (uint32_t i = 0; i < 16; i++)
				weights[i] = bc7u::read_bits32(pBuf, bit_offset, ((!i) || (i == basist::g_bc7_table_anchor_index_second_subset[part])) ? (WEIGHT_BITS - 1) : WEIGHT_BITS);

			assert(bit_offset == 128);

			for (uint32_t e = 0; e < ENDPOINTS; e++)
				for (uint32_t c = 0; c < 4; c++)
					endpoints[e][c] = (uint8_t)bc7u::bc7_dequant(endpoints[e][c], pbits[e], ENDPOINT_BITS);
			
			log_blk.m_num_partitions = 2;
			
			log_blk.m_color_endpoint_modes[0] = 12;
			log_blk.m_color_endpoint_modes[1] = 12;

			log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;
			
			bool use_4x4_2subsets_flag = false;

			{
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_24_LEVELS;

				const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
				const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;

				log_blk.m_endpoints[0] = endpoint_to_ise[endpoints[0].r];
				log_blk.m_endpoints[1] = endpoint_to_ise[endpoints[1].r];
				log_blk.m_endpoints[2] = endpoint_to_ise[endpoints[0].g];
				log_blk.m_endpoints[3] = endpoint_to_ise[endpoints[1].g];
				log_blk.m_endpoints[4] = endpoint_to_ise[endpoints[0].b];
				log_blk.m_endpoints[5] = endpoint_to_ise[endpoints[1].b];
				log_blk.m_endpoints[6] = endpoint_to_ise[endpoints[0].a];
				log_blk.m_endpoints[7] = endpoint_to_ise[endpoints[1].a];

				log_blk.m_endpoints[8] = endpoint_to_ise[endpoints[2].r];
				log_blk.m_endpoints[9] = endpoint_to_ise[endpoints[3].r];
				log_blk.m_endpoints[10] = endpoint_to_ise[endpoints[2].g];
				log_blk.m_endpoints[11] = endpoint_to_ise[endpoints[3].g];
				log_blk.m_endpoints[12] = endpoint_to_ise[endpoints[2].b];
				log_blk.m_endpoints[13] = endpoint_to_ise[endpoints[3].b];
				log_blk.m_endpoints[14] = endpoint_to_ise[endpoints[2].a];
				log_blk.m_endpoints[15] = endpoint_to_ise[endpoints[3].a];

				const int s0_0 = endpoint_from_ise[log_blk.m_endpoints[0]] + endpoint_from_ise[log_blk.m_endpoints[2]] + endpoint_from_ise[log_blk.m_endpoints[4]];
				const int s0_1 = endpoint_from_ise[log_blk.m_endpoints[1]] + endpoint_from_ise[log_blk.m_endpoints[3]] + endpoint_from_ise[log_blk.m_endpoints[5]];

				const int s1_0 = endpoint_from_ise[log_blk.m_endpoints[8]] + endpoint_from_ise[log_blk.m_endpoints[10]] + endpoint_from_ise[log_blk.m_endpoints[12]];
				const int s1_1 = endpoint_from_ise[log_blk.m_endpoints[9]] + endpoint_from_ise[log_blk.m_endpoints[11]] + endpoint_from_ise[log_blk.m_endpoints[13]];

				uint32_t invw[2] = { 0, 0 };
				if (s0_1 < s0_0)
				{
					std::swap(log_blk.m_endpoints[0], log_blk.m_endpoints[1]);
					std::swap(log_blk.m_endpoints[2], log_blk.m_endpoints[3]);
					std::swap(log_blk.m_endpoints[4], log_blk.m_endpoints[5]);
					std::swap(log_blk.m_endpoints[6], log_blk.m_endpoints[7]);
					invw[0] = WEIGHT_MASK;
				}

				if (s1_1 < s1_0)
				{
					std::swap(log_blk.m_endpoints[8], log_blk.m_endpoints[9]);
					std::swap(log_blk.m_endpoints[10], log_blk.m_endpoints[11]);
					std::swap(log_blk.m_endpoints[12], log_blk.m_endpoints[13]);
					std::swap(log_blk.m_endpoints[14], log_blk.m_endpoints[15]);
					invw[1] = WEIGHT_MASK;
				}

				if (invert_subsets_flag)
				{
					for (uint32_t i = 0; i < 8; i++)
					{
						std::swap(log_blk.m_endpoints[i], log_blk.m_endpoints[i + 8]);
					}
					std::swap(invw[0], invw[1]);
				}

				uint8_t temp_weights[16];
				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t bc7_w = weights[i];

					uint32_t subset = astc_helpers::get_precomputed_texel_partition(4, 4, log_blk.m_partition_id, i & 3, i >> 2, 2);

					bc7_w ^= invw[subset];

					temp_weights[i] = (uint8_t)bc7_w;
				}

				astc_weight_grid_2d grid_res = choose_astc_weight_grid_4x4_block(temp_weights, 4);
								
				if (grid_res >= ASTC_WEIGHT_GRID_4X3)
				{
					if (grid_res == ASTC_WEIGHT_GRID_3X4)
					{
						log_blk.m_grid_width = 3;
						bc7_weights_4x4_to_3x4_avg_u(temp_weights, log_blk.m_weights, 0);
					}
					else
					{
						assert(grid_res == ASTC_WEIGHT_GRID_4X3);
						log_blk.m_grid_height = 3;
						bc7_weights_4x4_to_4x3_avg_u(temp_weights, log_blk.m_weights, 0);
					}
				}
				else
				{
					use_4x4_2subsets_flag = true;
				}
			}

			if (use_4x4_2subsets_flag)
			{
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_16_LEVELS;
				
				const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
				const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
				
				log_blk.m_endpoints[0] = endpoint_to_ise[endpoints[0].r];
				log_blk.m_endpoints[1] = endpoint_to_ise[endpoints[1].r];
				log_blk.m_endpoints[2] = endpoint_to_ise[endpoints[0].g];
				log_blk.m_endpoints[3] = endpoint_to_ise[endpoints[1].g];
				log_blk.m_endpoints[4] = endpoint_to_ise[endpoints[0].b];
				log_blk.m_endpoints[5] = endpoint_to_ise[endpoints[1].b];
				log_blk.m_endpoints[6] = endpoint_to_ise[endpoints[0].a];
				log_blk.m_endpoints[7] = endpoint_to_ise[endpoints[1].a];

				log_blk.m_endpoints[8] = endpoint_to_ise[endpoints[2].r];
				log_blk.m_endpoints[9] = endpoint_to_ise[endpoints[3].r];
				log_blk.m_endpoints[10] = endpoint_to_ise[endpoints[2].g];
				log_blk.m_endpoints[11] = endpoint_to_ise[endpoints[3].g];
				log_blk.m_endpoints[12] = endpoint_to_ise[endpoints[2].b];
				log_blk.m_endpoints[13] = endpoint_to_ise[endpoints[3].b];
				log_blk.m_endpoints[14] = endpoint_to_ise[endpoints[2].a];
				log_blk.m_endpoints[15] = endpoint_to_ise[endpoints[3].a];

				const int s0_0 = endpoint_from_ise[log_blk.m_endpoints[0]] + endpoint_from_ise[log_blk.m_endpoints[2]] + endpoint_from_ise[log_blk.m_endpoints[4]];
				const int s0_1 = endpoint_from_ise[log_blk.m_endpoints[1]] + endpoint_from_ise[log_blk.m_endpoints[3]] + endpoint_from_ise[log_blk.m_endpoints[5]];

				const int s1_0 = endpoint_from_ise[log_blk.m_endpoints[8]] + endpoint_from_ise[log_blk.m_endpoints[10]] + endpoint_from_ise[log_blk.m_endpoints[12]];
				const int s1_1 = endpoint_from_ise[log_blk.m_endpoints[9]] + endpoint_from_ise[log_blk.m_endpoints[11]] + endpoint_from_ise[log_blk.m_endpoints[13]];

				uint32_t invw[2] = { 0, 0 };
				if (s0_1 < s0_0)
				{
					std::swap(log_blk.m_endpoints[0], log_blk.m_endpoints[1]);
					std::swap(log_blk.m_endpoints[2], log_blk.m_endpoints[3]);
					std::swap(log_blk.m_endpoints[4], log_blk.m_endpoints[5]);
					std::swap(log_blk.m_endpoints[6], log_blk.m_endpoints[7]);
					invw[0] = WEIGHT_MASK;
				}

				if (s1_1 < s1_0)
				{
					std::swap(log_blk.m_endpoints[8], log_blk.m_endpoints[9]);
					std::swap(log_blk.m_endpoints[10], log_blk.m_endpoints[11]);
					std::swap(log_blk.m_endpoints[12], log_blk.m_endpoints[13]);
					std::swap(log_blk.m_endpoints[14], log_blk.m_endpoints[15]);
					invw[1] = WEIGHT_MASK;
				}

				if (invert_subsets_flag)
				{
					for (uint32_t i = 0; i < 8; i++)
					{
						std::swap(log_blk.m_endpoints[i], log_blk.m_endpoints[i + 8]);
					}
					std::swap(invw[0], invw[1]);
				}

				for (uint32_t i = 0; i < 16; i++)
				{
					uint32_t bc7_w = weights[i];

					uint32_t subset = astc_helpers::get_precomputed_texel_partition(4, 4, log_blk.m_partition_id, i & 3, i >> 2, 2);

					bc7_w ^= invw[subset];

					log_blk.m_weights[i] = (uint8_t)bc7_w;
				}
			}

			break;
		}
		case 0:
		case 2:
		{
			// 2/3 subset transcoders need the block's texels for higher weight quality, this is a rarer path so it's fine
			// TODO: pass in the physical block and have it unpack only if the pattern is mappable
			color_rgba block_texels[16];
			if (!pPixels)
			{
				if (!bc7u::unpack_bc7(&phys_bc7_block, block_texels))
					return false;

				pPixels = block_texels;
			}

			return fast_pack_astc_3subsets(mode, log_blk, phys_bc7_block, pPixels);
		}
		case 1:
		case 3:
		{
			// 2/3 subset transcoders need the block's texels for higher weight quality, this is a rarer path so it's fine
			// TODO: pass in the physical block and have it unpack only if the pattern is mappable
			color_rgba block_texels[16];
			if (!pPixels)
			{
				if (!bc7u::unpack_bc7(&phys_bc7_block, block_texels))
					return false;

				pPixels = block_texels;
			}

			return fast_pack_astc_2subsets(mode, log_blk, phys_bc7_block, pPixels);
		}
		case 4:
		case 5:
		{
			// TODO: Add BC support
			// 
			// dual plane
			const uint32_t ENDPOINTS = 2;
			const uint32_t COMPS = 4;
			const uint32_t WEIGHT_BITS = 2;
			const uint32_t A_WEIGHT_BITS = (mode == 4) ? 3 : 2;
			const uint32_t ENDPOINT_BITS = (mode == 4) ? 5 : 7;
			const uint32_t A_ENDPOINT_BITS = (mode == 4) ? 6 : 8;
			//const uint32_t WEIGHT_VALS = 1 << WEIGHT_BITS;
			//const uint32_t A_WEIGHT_VALS = 1 << A_WEIGHT_BITS;

			uint32_t bit_offset = mode + 1;
			const uint8_t* pBuf = reinterpret_cast<const uint8_t*>(&phys_bc7_block);

			const uint32_t comp_rot = bc7u::read_bits32(pBuf, bit_offset, 2);
			const uint32_t index_mode = (mode == 4) ? bc7u::read_bits32(pBuf, bit_offset, 1) : 0;

			color_rgba endpoints[ENDPOINTS];
			for (uint32_t c = 0; c < COMPS; c++)
				for (uint32_t e = 0; e < ENDPOINTS; e++)
					endpoints[e][c] = (uint8_t)bc7u::read_bits32(pBuf, bit_offset, (c == 3) ? A_ENDPOINT_BITS : ENDPOINT_BITS);

			//const uint32_t endpoint_bits[2] = { ENDPOINT_BITS, A_ENDPOINT_BITS };
			const uint32_t weight_bits[2] = { index_mode ? A_WEIGHT_BITS : WEIGHT_BITS,  index_mode ? WEIGHT_BITS : A_WEIGHT_BITS };

			uint8_t weights[16], a_weights[16];

			for (uint32_t i = 0; i < 16; i++)
				(index_mode ? a_weights : weights)[i] = (uint8_t)bc7u::read_bits32(pBuf, bit_offset, weight_bits[index_mode] - ((!i) ? 1 : 0));

			for (uint32_t i = 0; i < 16; i++)
				(index_mode ? weights : a_weights)[i] = (uint8_t)bc7u::read_bits32(pBuf, bit_offset, weight_bits[1 - index_mode] - ((!i) ? 1 : 0));

			if ((weights[0] == weights[15]) && (a_weights[0] == a_weights[15]))
			{
				// solid check (we're assuming solid blocks always use mode 4 or 5, which is very common)
				uint32_t k;
				for (k = 1; k < 15; k++)
				{
					if (weights[0] != weights[k])
						break;
					if (a_weights[0] != a_weights[k])
						break;
				}
								
				if (k == 15)
				{
					bc7u::log_bc7_block bc7_log_blk;
					if (!bc7u::unpack_bc7(&phys_bc7_block, bc7_log_blk))
						return false;

					assert(bc7u::is_solid_blk(bc7_log_blk));

					color_rgba solid_color;
					bc7u::unpack_bc7_texel(bc7_log_blk, solid_color, 0, 0);

					set_solid(log_blk, solid_color.r, solid_color.g, solid_color.b, solid_color.a);
					return true;
				}
			}
			else
			{
#if defined(DEBUG) || defined(_DEBUG)
				bc7u::log_bc7_block bc7_log_blk;
				if (!bc7u::unpack_bc7(&phys_bc7_block, bc7_log_blk))
					return false;

				assert(!bc7u::is_solid_blk(bc7_log_blk));
#endif
			}

			assert(bit_offset == 128);

			for (uint32_t e = 0; e < ENDPOINTS; e++)
				for (uint32_t c = 0; c < 4; c++)
					endpoints[e][c] = (uint8_t)bc7u::bc7_dequant(endpoints[e][c], (c == 3) ? A_ENDPOINT_BITS : ENDPOINT_BITS);

			if (comp_rot >= 1)
			{
				std::swap(endpoints[0][3], endpoints[0][comp_rot - 1]);
				std::swap(endpoints[1][3], endpoints[1][comp_rot - 1]);
			}

			log_blk.m_num_partitions = 1;
			log_blk.m_dual_plane = true;
			log_blk.m_color_component_selector = (comp_rot - 1) & 3;

			const uint32_t err_3x4 = eval_block_sse_as_3x4(weights) + eval_block_sse_as_3x4(a_weights);
			const uint32_t err_4x3 = eval_block_sse_as_4x3(weights) + eval_block_sse_as_4x3(a_weights);

			const uint32_t w_thresh = ((weight_bits[0] > 4) ? 6 : 4) + ((weight_bits[1] > 4) ? 6 : 4);

			if ((err_3x4 <= w_thresh) || (err_4x3 <= w_thresh))
			{
				uint8_t weights0[12], weights1[12];

				if (err_3x4 <= err_4x3)
				{
					log_blk.m_grid_width = 3;
					bc7_weights_4x4_to_3x4_avg_u(weights, weights0, 0);
					bc7_weights_4x4_to_3x4_avg_u(a_weights, weights1, 0);
				}
				else
				{
					log_blk.m_grid_height = 3;
					bc7_weights_4x4_to_4x3_avg_u(weights, weights0, 0);
					bc7_weights_4x4_to_4x3_avg_u(a_weights, weights1, 0);
				}

				bool invw = false;
				const basisu::uint8_vec* pWeight_to_ise;

				const bool uses_3bit_weights = (weight_bits[0] == 3) || (weight_bits[1] == 3);

				if ((endpoints[0][3] == 255) && (endpoints[1][3] == 255))
				{
					log_blk.m_color_endpoint_modes[0] = 8;
					if (uses_3bit_weights)
					{
						log_blk.m_endpoint_ise_range = astc_helpers::BISE_64_LEVELS;
						log_blk.m_weight_ise_range = astc_helpers::BISE_8_LEVELS;
					}
					else
					{
						log_blk.m_endpoint_ise_range = astc_helpers::BISE_256_LEVELS;
						log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;
					}

					const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
					const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
					pWeight_to_ise = &astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_val_to_ise;

					log_blk.m_endpoints[0] = endpoint_to_ise[endpoints[0].r];
					log_blk.m_endpoints[1] = endpoint_to_ise[endpoints[1].r];

					log_blk.m_endpoints[2] = endpoint_to_ise[endpoints[0].g];
					log_blk.m_endpoints[3] = endpoint_to_ise[endpoints[1].g];

					log_blk.m_endpoints[4] = endpoint_to_ise[endpoints[0].b];
					log_blk.m_endpoints[5] = endpoint_to_ise[endpoints[1].b];

					int s0 = endpoint_from_ise[log_blk.m_endpoints[0]] + endpoint_from_ise[log_blk.m_endpoints[2]] + endpoint_from_ise[log_blk.m_endpoints[4]];
					int s1 = endpoint_from_ise[log_blk.m_endpoints[1]] + endpoint_from_ise[log_blk.m_endpoints[3]] + endpoint_from_ise[log_blk.m_endpoints[5]];

					if (s1 < s0)
					{
						std::swap(log_blk.m_endpoints[0], log_blk.m_endpoints[1]);
						std::swap(log_blk.m_endpoints[2], log_blk.m_endpoints[3]);
						std::swap(log_blk.m_endpoints[4], log_blk.m_endpoints[5]);
						invw = true;
					}
				}
				else
				{
					log_blk.m_color_endpoint_modes[0] = 12;
					if (uses_3bit_weights)
					{
						// could use 24/8 - or decide via approx SSE calcs
						log_blk.m_endpoint_ise_range = astc_helpers::BISE_48_LEVELS;
						log_blk.m_weight_ise_range = astc_helpers::BISE_6_LEVELS;
					}
					else
					{
						log_blk.m_endpoint_ise_range = astc_helpers::BISE_192_LEVELS;
						log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;
					}

					const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
					const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
					pWeight_to_ise = &astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_val_to_ise;

					log_blk.m_endpoints[0] = endpoint_to_ise[endpoints[0].r];
					log_blk.m_endpoints[1] = endpoint_to_ise[endpoints[1].r];

					log_blk.m_endpoints[2] = endpoint_to_ise[endpoints[0].g];
					log_blk.m_endpoints[3] = endpoint_to_ise[endpoints[1].g];

					log_blk.m_endpoints[4] = endpoint_to_ise[endpoints[0].b];
					log_blk.m_endpoints[5] = endpoint_to_ise[endpoints[1].b];

					log_blk.m_endpoints[6] = endpoint_to_ise[endpoints[0].a];
					log_blk.m_endpoints[7] = endpoint_to_ise[endpoints[1].a];

					int s0 = endpoint_from_ise[log_blk.m_endpoints[0]] + endpoint_from_ise[log_blk.m_endpoints[2]] + endpoint_from_ise[log_blk.m_endpoints[4]];
					int s1 = endpoint_from_ise[log_blk.m_endpoints[1]] + endpoint_from_ise[log_blk.m_endpoints[3]] + endpoint_from_ise[log_blk.m_endpoints[5]];

					if (s1 < s0)
					{
						std::swap(log_blk.m_endpoints[0], log_blk.m_endpoints[1]);
						std::swap(log_blk.m_endpoints[2], log_blk.m_endpoints[3]);
						std::swap(log_blk.m_endpoints[4], log_blk.m_endpoints[5]);
						std::swap(log_blk.m_endpoints[6], log_blk.m_endpoints[7]);
						invw = true;
					}
				}

				const int w0_max = (1 << weight_bits[0]) - 1;
				const int w0_half = w0_max >> 1;

				const int w1_max = (1 << weight_bits[1]) - 1;
				const int w1_half = w1_max >> 1;

				for (uint32_t w = 0; w < 12; w++)
				{
					int w0 = (weights0[w] * 64 + w0_half) / w0_max;
					int w1 = (weights1[w] * 64 + w1_half) / w1_max;

					if (invw)
					{
						w0 = 64 - w0;
						w1 = 64 - w1;
					}

					log_blk.m_weights[w * 2 + 0] = (*pWeight_to_ise)[w0];
					log_blk.m_weights[w * 2 + 1] = (*pWeight_to_ise)[w1];
				}
			}
			else
			{
				bool invw = false;
				const basisu::uint8_vec* pWeight_to_ise;

				if ((endpoints[0][3] == 255) && (endpoints[1][3] == 255))
				{
					log_blk.m_color_endpoint_modes[0] = 8;
					log_blk.m_endpoint_ise_range = astc_helpers::BISE_160_LEVELS;
					log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;

					const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
					const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
					pWeight_to_ise = &astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_val_to_ise;

					log_blk.m_endpoints[0] = endpoint_to_ise[endpoints[0].r];
					log_blk.m_endpoints[1] = endpoint_to_ise[endpoints[1].r];

					log_blk.m_endpoints[2] = endpoint_to_ise[endpoints[0].g];
					log_blk.m_endpoints[3] = endpoint_to_ise[endpoints[1].g];

					log_blk.m_endpoints[4] = endpoint_to_ise[endpoints[0].b];
					log_blk.m_endpoints[5] = endpoint_to_ise[endpoints[1].b];

					int s0 = endpoint_from_ise[log_blk.m_endpoints[0]] + endpoint_from_ise[log_blk.m_endpoints[2]] + endpoint_from_ise[log_blk.m_endpoints[4]];
					int s1 = endpoint_from_ise[log_blk.m_endpoints[1]] + endpoint_from_ise[log_blk.m_endpoints[3]] + endpoint_from_ise[log_blk.m_endpoints[5]];

					if (s1 < s0)
					{
						std::swap(log_blk.m_endpoints[0], log_blk.m_endpoints[1]);
						std::swap(log_blk.m_endpoints[2], log_blk.m_endpoints[3]);
						std::swap(log_blk.m_endpoints[4], log_blk.m_endpoints[5]);
						invw = true;
					}
				}
				else
				{
					log_blk.m_color_endpoint_modes[0] = 12;
					log_blk.m_endpoint_ise_range = astc_helpers::BISE_48_LEVELS;
					log_blk.m_weight_ise_range = astc_helpers::BISE_4_LEVELS;

					const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
					const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
					pWeight_to_ise = &astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_val_to_ise;

					log_blk.m_endpoints[0] = endpoint_to_ise[endpoints[0].r];
					log_blk.m_endpoints[1] = endpoint_to_ise[endpoints[1].r];

					log_blk.m_endpoints[2] = endpoint_to_ise[endpoints[0].g];
					log_blk.m_endpoints[3] = endpoint_to_ise[endpoints[1].g];

					log_blk.m_endpoints[4] = endpoint_to_ise[endpoints[0].b];
					log_blk.m_endpoints[5] = endpoint_to_ise[endpoints[1].b];

					log_blk.m_endpoints[6] = endpoint_to_ise[endpoints[0].a];
					log_blk.m_endpoints[7] = endpoint_to_ise[endpoints[1].a];

					int s0 = endpoint_from_ise[log_blk.m_endpoints[0]] + endpoint_from_ise[log_blk.m_endpoints[2]] + endpoint_from_ise[log_blk.m_endpoints[4]];
					int s1 = endpoint_from_ise[log_blk.m_endpoints[1]] + endpoint_from_ise[log_blk.m_endpoints[3]] + endpoint_from_ise[log_blk.m_endpoints[5]];

					if (s1 < s0)
					{
						std::swap(log_blk.m_endpoints[0], log_blk.m_endpoints[1]);
						std::swap(log_blk.m_endpoints[2], log_blk.m_endpoints[3]);
						std::swap(log_blk.m_endpoints[4], log_blk.m_endpoints[5]);
						std::swap(log_blk.m_endpoints[6], log_blk.m_endpoints[7]);
						invw = true;
					}
				}

				const int w0_max = (1 << weight_bits[0]) - 1;
				const int w0_half = w0_max >> 1;

				const int w1_max = (1 << weight_bits[1]) - 1;
				const int w1_half = w1_max >> 1;

				for (uint32_t w = 0; w < 16; w++)
				{
					int w0 = (weights[w] * 64 + w0_half) / w0_max;
					int w1 = (a_weights[w] * 64 + w1_half) / w1_max;

					if (invw)
					{
						w0 = 64 - w0;
						w1 = 64 - w1;
					}

					log_blk.m_weights[w * 2 + 0] = (*pWeight_to_ise)[w0];
					log_blk.m_weights[w * 2 + 1] = (*pWeight_to_ise)[w1];
				}
			}
			break;
		}
		case 6:
		{
			// mode 6
			assert(mode == 6);

			bc7u::bc7_mode_6& mode6 = *(bc7u::bc7_mode_6*)&phys_bc7_block;

			uint8_t weights[16];
			weights[0] = mode6.m_hi.m_s00; weights[1] = mode6.m_hi.m_s10; weights[2] = mode6.m_hi.m_s20; weights[3] = mode6.m_hi.m_s30;
			weights[4] = mode6.m_hi.m_s01; weights[5] = mode6.m_hi.m_s11; weights[6] = mode6.m_hi.m_s21; weights[7] = mode6.m_hi.m_s31;
			weights[8] = mode6.m_hi.m_s02; weights[9] = mode6.m_hi.m_s12; weights[10] = mode6.m_hi.m_s22; weights[11] = mode6.m_hi.m_s32;
			weights[12] = mode6.m_hi.m_s03; weights[13] = mode6.m_hi.m_s13; weights[14] = mode6.m_hi.m_s23; weights[15] = mode6.m_hi.m_s33;
						
			log_blk.m_num_partitions = 1;
						
			if ((mode6.m_lo.m_a0 < 127) || (mode6.m_lo.m_a1 < 127))
			{
				log_blk.m_color_endpoint_modes[0] = 12;
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_96_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_12_LEVELS;

				const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
				const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
				//const auto& weight_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;

				int p0 = mode6.m_lo.m_p0;
				int r0 = bc7f::from_7(mode6.m_lo.m_r0, p0);
				int g0 = bc7f::from_7(mode6.m_lo.m_g0, p0);
				int b0 = bc7f::from_7(mode6.m_lo.m_b0, p0);
				int a0 = bc7f::from_7(mode6.m_lo.m_a0, p0);

				int p1 = mode6.m_hi.m_p1;
				int r1 = bc7f::from_7(mode6.m_lo.m_r1, p1);
				int g1 = bc7f::from_7(mode6.m_lo.m_g1, p1);
				int b1 = bc7f::from_7(mode6.m_lo.m_b1, p1);
				int a1 = bc7f::from_7(mode6.m_lo.m_a1, p1);

				color_rgba endpoints[2] = { color_rgba(r0, g0, b0, a0), color_rgba(r1, g1, b1, a1) };
				uint8_t invw = cem_encode_bc(12, &log_blk.m_endpoints[0], &endpoints[0], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise) ? 15 : 0;

				static const uint8_t s_pWeight_to_ise[16] = { 0, 4, 8, 8, 2, 6, 10, 10, 11, 11, 7, 3, 9, 9, 5, 1 };
				for (uint32_t w = 0; w < 16; w++)
					log_blk.m_weights[w] = s_pWeight_to_ise[weights[w] ^ invw];
				
				return true;
			}

			astc_weight_grid_2d grid_res = choose_astc_weight_grid_4x4_block(weights, 6);

			if ((grid_res == ASTC_WEIGHT_GRID_3X4) || (grid_res == ASTC_WEIGHT_GRID_4X3))
			{
				if (grid_res == ASTC_WEIGHT_GRID_3X4)
					log_blk.m_grid_width = 3;
				else
					log_blk.m_grid_height = 3;

				log_blk.m_color_endpoint_modes[0] = 8;
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_256_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_16_LEVELS;

				int p0 = mode6.m_lo.m_p0;
				int r0 = bc7f::from_7(mode6.m_lo.m_r0, p0);
				int g0 = bc7f::from_7(mode6.m_lo.m_g0, p0);
				int b0 = bc7f::from_7(mode6.m_lo.m_b0, p0);

				int p1 = mode6.m_hi.m_p1;
				int r1 = bc7f::from_7(mode6.m_lo.m_r1, p1);
				int g1 = bc7f::from_7(mode6.m_lo.m_g1, p1);
				int b1 = bc7f::from_7(mode6.m_lo.m_b1, p1);

				color_rgba endpoints[2] = { color_rgba(r0, g0, b0, 255), color_rgba(r1, g1, b1, 255) };

				const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
				const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;

				uint8_t invw = cem_encode_no_bc(8, &log_blk.m_endpoints[0], &endpoints[0], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise) ? 15 : 0;

				if (grid_res == ASTC_WEIGHT_GRID_3X4)
					bc7_weights_4x4_to_3x4_avg_u(weights, log_blk.m_weights, invw);
				else
				{
					assert(grid_res == ASTC_WEIGHT_GRID_4X3);
					bc7_weights_4x4_to_4x3_avg_u(weights, log_blk.m_weights, invw);
				}
			}
			else
			{
				log_blk.m_color_endpoint_modes[0] = 8;
				log_blk.m_endpoint_ise_range = astc_helpers::BISE_192_LEVELS;
				log_blk.m_weight_ise_range = astc_helpers::BISE_16_LEVELS;

				const auto& endpoint_to_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_val_to_ise;
				const auto& endpoint_from_ise = astc_helpers::g_dequant_tables.get_endpoint_tab(log_blk.m_endpoint_ise_range).m_ISE_to_val;
				//const auto& weight_to_ise = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range).m_rank_to_ISE;

				int p0 = mode6.m_lo.m_p0;
				int r0 = bc7f::from_7(mode6.m_lo.m_r0, p0);
				int g0 = bc7f::from_7(mode6.m_lo.m_g0, p0);
				int b0 = bc7f::from_7(mode6.m_lo.m_b0, p0);

				int p1 = mode6.m_hi.m_p1;
				int r1 = bc7f::from_7(mode6.m_lo.m_r1, p1);
				int g1 = bc7f::from_7(mode6.m_lo.m_g1, p1);
				int b1 = bc7f::from_7(mode6.m_lo.m_b1, p1);

				color_rgba endpoints[2] = { color_rgba(r0, g0, b0, 255), color_rgba(r1, g1, b1, 255) };
				uint8_t invw = cem_encode_bc(8, &log_blk.m_endpoints[0], &endpoints[0], log_blk.m_endpoint_ise_range, endpoint_to_ise, endpoint_from_ise) ? 15 : 0;

				for (uint32_t w = 0; w < 16; w++)
					log_blk.m_weights[w] = (uint8_t)(weights[w] ^ invw);
			}
			break;
		}
		default:
		{
			assert(0);
			log_blk.m_error_flag = true;
			return false;
		}
		}

		return true;
	}
		
	bool fast_pack_astc(astc_helpers::log_astc_block& log_blk, const color_rgba* pPixels, uint32_t bc7f_override_flags)
	{
		log_blk.clear();
		
		const uint32_t fc = *(const uint32_t*)&pPixels[0];
		if (fc == *(const uint32_t*)&pPixels[15])
		{
			int k;
			for (k = 1; k < 15; k++)
				if (*(const uint32_t*)&pPixels[k] != fc)
					break;

			if (k == 15)
			{
				const uint32_t r = pPixels[0].r, g = pPixels[0].g, b = pPixels[0].b, a = pPixels[0].a;

				set_solid(log_blk, r, g, b, a);
				return true;
			}
		}

		log_blk.m_grid_width = 4;
		log_blk.m_grid_height = 4;

		basist::bc7_block bc7_block;
		uint32_t flags = bc7f_override_flags;
		if (!flags)
		{
			flags = cPackBC7FlagPBitOpt | cPackBC7FlagPBitOptMode6 | cPackBC7FlagUseTrivialMode6 | cPackBC7FlagUse2SubsetsRGB | cPackBC7FlagASTCCompatible |
				cPackBC7FlagUseDualPlaneRGB | cPackBC7FlagUseDualPlaneRGBA |
				cPackBC7FlagUse3SubsetsRGB | cPackBC7FlagUse2SubsetsRGBA;
		}
		else
		{
			// ensure it's on otherwise the transcode can/will fail
			flags |= cPackBC7FlagASTCCompatible;
		}

		fast_pack_bc7_auto_rgba((uint8_t*)&bc7_block, pPixels, flags);

		return fast_pack_astc(bc7_block, log_blk, pPixels);
	}

	bool fast_pack_astc(void* pASTC_block, const color_rgba* pPixels, uint32_t bc7f_override_flags)
	{
		astc_helpers::log_astc_block log_blk;

		if (!fast_pack_astc(log_blk, pPixels, bc7f_override_flags))
		{
			assert(0);
			memset(pASTC_block, 0, sizeof(astc_helpers::astc_block));
			return false;
		}

		bool pack_status = astc_helpers::pack_astc_block(*(astc_helpers::astc_block*)pASTC_block, log_blk);
		assert(pack_status);

		if (!pack_status)
		{
			memset(pASTC_block, 0, sizeof(astc_helpers::astc_block));
			return false;
		}

		return true;
	}

	// BC7->logical ASTC block
	bool fast_pack_astc(astc_helpers::log_astc_block& log_astc_blk, const basist::bc7_block& phys_bc7_block, uint32_t bc7f_override_flags)
	{
		// First try latent to latent transcoding, if that fails due to an unmappable 2/3 subset pattern index (hopefully rarely!) fall back to real-time raw encoding using bc7f in ASTC-friendly mode, then transcode.
		bool pack_status = fast_pack_astc(phys_bc7_block, log_astc_blk, nullptr);
		if (!pack_status)
		{
			// Fallback, should be relatively rare
			color_rgba block_texels[16];
			if (!bc7u::unpack_bc7(&phys_bc7_block, block_texels))
			{
				assert(0);
				log_astc_blk.m_error_flag = true;
				return false;
			}
						
			return fast_pack_astc(log_astc_blk, block_texels, bc7f_override_flags | cPackBC7FlagASTCCompatible);
		}

		return true;
	}

	// BC7->physical ASTC block
	bool fast_pack_astc(void *pASTC_block, const basist::bc7_block& phys_bc7_block, uint32_t bc7f_override_flags)
	{
		astc_helpers::log_astc_block log_blk;

		if (!fast_pack_astc(log_blk, phys_bc7_block, bc7f_override_flags))
		{
			assert(0);
			memset(pASTC_block, 0, sizeof(astc_helpers::astc_block));
			return false;
		}

		bool pack_status = astc_helpers::pack_astc_block(*(astc_helpers::astc_block*)pASTC_block, log_blk);
		assert(pack_status);

		if (!pack_status)
		{
			memset(pASTC_block, 0, sizeof(astc_helpers::astc_block));
			return false;
		}

		return true;
	}

} // namespace bc7f

namespace bc7u
{
	int dequant_weight(uint32_t w, uint32_t num_weight_bits)
	{
		switch (num_weight_bits)
		{
		case 2: assert(w < 4); return basist::g_bc7_weights2[w];
		case 3: assert(w < 8); return basist::g_bc7_weights3[w];
		case 4: assert(w < 16); return basist::g_bc7_weights4[w];
		default:
			assert(0);
			break;
		}
		return 0;
	}

	uint8_t g_weight_quant[3][65]; // [2-4][0-64] - maps [0,64] normalized weight to nearest quantized value

	void init_weight_quant()
	{
		for (uint32_t num_weight_bits = 2; num_weight_bits <= 4; num_weight_bits++)
		{
			const uint32_t num_weight_vals = 1 << num_weight_bits;

			for (int de = 0; de <= 64; de++)
			{
				uint32_t best_idx = 0, best_err = UINT32_MAX;

				for (uint32_t idx = 0; idx < num_weight_vals; idx++)
				{
					const int dequant = dequant_weight(idx, num_weight_bits);

					const uint32_t err = basisu::iabs(de - dequant);
					if (err < best_err)
					{
						best_err = err;
						best_idx = idx;
					}
				} // idx

				g_weight_quant[num_weight_bits - 2][de] = (uint8_t)best_idx;

			} // de

		} // num_bits
	}

	// 0-8 bits only
	inline uint8_t fetch_bits(const void* p, uint32_t num_bits, uint32_t& bit_ofs)
	{
		if (!num_bits)
			return 0;

		assert((num_bits >= 1) && (num_bits <= 8));

		if ((bit_ofs + num_bits) > 128)
		{
			assert(0);
			return 0;
		}

		const uint8_t* pBytes = static_cast<const uint8_t*>(p);

		const uint32_t byte_ofs = bit_ofs >> 3;

		const uint8_t b0 = pBytes[byte_ofs];
		const uint8_t b1 = pBytes[basisu::minimum<uint32_t>(15, byte_ofs + 1)];

		const uint32_t b = (b0 | (b1 << 8)) >> (bit_ofs & 7);

		const uint32_t res = b & ((1u << num_bits) - 1u);

		bit_ofs += num_bits;

		return static_cast<uint8_t>(res);
	}

	bool unpack_bc7(const void* pPhys_block, log_bc7_block& log_blk)
	{
		log_blk.clear();

		const int mode = determine_bc7_mode(pPhys_block);
		log_blk.m_mode = (int8_t)mode;
		if (mode < 0)
			return false;

		uint32_t bit_ofs = mode + 1;

		switch (mode)
		{
		case 0:
		case 2:
		{
			log_blk.m_num_partitions = 3;
			log_blk.m_pattern_bits = (mode == 0) ? 4 : 6;
			log_blk.m_num_planes = 1;
			log_blk.m_endpoint_bits[0] = (mode == 0) ? 4 : 5;
			log_blk.m_num_pbits = (mode == 0) ? 6 : 0;
			log_blk.m_weight_bits[0] = (mode == 0) ? 3 : 2;

			log_blk.m_pattern_index = fetch_bits(pPhys_block, log_blk.m_pattern_bits, bit_ofs);

			for (uint32_t c = 0; c < 3; c++)
				for (uint32_t s = 0; s < 3; s++)
					for (uint32_t e = 0; e < 2; e++)
						log_blk.m_endpoints[s][e][c] = fetch_bits(pPhys_block, log_blk.m_endpoint_bits[0], bit_ofs);

			for (uint32_t p = 0; p < log_blk.m_num_pbits; p++)
				log_blk.m_pbits[p] = fetch_bits(pPhys_block, 1, bit_ofs);

			for (uint32_t i = 0; i < 16; i++)
			{
				log_blk.m_weights[0][i] = fetch_bits(pPhys_block,
					((!i) || (i == basist::g_bc7_table_anchor_index_third_subset_1[log_blk.m_pattern_index]) || (i == basist::g_bc7_table_anchor_index_third_subset_2[log_blk.m_pattern_index])) ? (log_blk.m_weight_bits[0] - 1) : log_blk.m_weight_bits[0],
					bit_ofs);
			}

			assert(bit_ofs == 128);

			break;
		}
		case 1:
		case 3:
		case 7:
		{
			log_blk.m_num_partitions = 2;
			log_blk.m_pattern_bits = 6;
			log_blk.m_num_planes = 1;
			log_blk.m_endpoint_bits[0] = (mode == 7) ? 5 : ((mode == 1) ? 6 : 7);
			log_blk.m_endpoint_bits[1] = (mode == 7) ? 5 : 0;
			log_blk.m_num_pbits = (mode == 1) ? 2 : 4;
			log_blk.m_shared_pbits = (mode == 1);
			log_blk.m_weight_bits[0] = (mode == 1) ? 3 : 2;

			log_blk.m_pattern_index = fetch_bits(pPhys_block, log_blk.m_pattern_bits, bit_ofs);

			const uint32_t num_comps = (mode == 7) ? 4 : 3;

			for (uint32_t c = 0; c < num_comps; c++)
				for (uint32_t s = 0; s < 2; s++)
					for (uint32_t e = 0; e < 2; e++)
						log_blk.m_endpoints[s][e][c] = fetch_bits(pPhys_block, log_blk.m_endpoint_bits[0], bit_ofs);

			for (uint32_t p = 0; p < log_blk.m_num_pbits; p++)
				log_blk.m_pbits[p] = fetch_bits(pPhys_block, 1, bit_ofs);

			for (uint32_t i = 0; i < 16; i++)
			{
				log_blk.m_weights[0][i] = fetch_bits(pPhys_block,
					((!i) || (i == basist::g_bc7_table_anchor_index_second_subset[log_blk.m_pattern_index])) ? (log_blk.m_weight_bits[0] - 1) : log_blk.m_weight_bits[0],
					bit_ofs);
			}

			assert(bit_ofs == 128);

			break;
		}
		case 4:
		case 5:
		{
			log_blk.m_num_partitions = 1;
			log_blk.m_num_planes = 2;
			log_blk.m_endpoint_bits[0] = (mode == 4) ? 5 : 7;
			log_blk.m_endpoint_bits[1] = (mode == 4) ? 6 : 8;
			log_blk.m_weight_bits[0] = 2;
			log_blk.m_weight_bits[1] = (mode == 4) ? 3 : 2;

			log_blk.m_dp_rotation_index = fetch_bits(pPhys_block, 2, bit_ofs);

			log_blk.m_mode4_index_selector = (mode == 4) ? fetch_bits(pPhys_block, 1, bit_ofs) : 0;

			for (uint32_t c = 0; c < 4; c++)
				for (uint32_t e = 0; e < 2; e++)
					log_blk.m_endpoints[0][e][c] = fetch_bits(pPhys_block, log_blk.m_endpoint_bits[(c == 3) ? 1 : 0], bit_ofs);

			for (uint32_t plane_index = 0; plane_index < 2; plane_index++)
			{
				for (uint32_t i = 0; i < 16; i++)
				{
					log_blk.m_weights[plane_index][i] = fetch_bits(pPhys_block,
						(!i) ? (log_blk.m_weight_bits[plane_index] - 1) : log_blk.m_weight_bits[plane_index],
						bit_ofs);
				}
			}

			assert(bit_ofs == 128);

			break;
		}
		case 6:
		{
			log_blk.m_num_partitions = 1;
			log_blk.m_num_planes = 1;
			log_blk.m_endpoint_bits[0] = 7;
			log_blk.m_endpoint_bits[1] = 7;
			log_blk.m_num_pbits = 2;
			log_blk.m_weight_bits[0] = 4;

			for (uint32_t c = 0; c < 4; c++)
			{
				log_blk.m_endpoints[0][0][c] = fetch_bits(pPhys_block, 7, bit_ofs);
				log_blk.m_endpoints[0][1][c] = fetch_bits(pPhys_block, 7, bit_ofs);
			}

			for (uint32_t p = 0; p < 2; p++)
				log_blk.m_pbits[p] = fetch_bits(pPhys_block, 1, bit_ofs);

			for (uint32_t w = 0; w < 16; w++)
				log_blk.m_weights[0][w] = fetch_bits(pPhys_block, (w == 0) ? 3 : 4, bit_ofs);

			assert(bit_ofs == 128);

			break;
		}
		default:
		{
			assert(0);
			break;
		}
		}

		return true;
	}

	void unpack_endpoints(const log_bc7_block& log_blk, color_rgba pEndpoints[2], uint32_t subset)
	{
		assert(subset < log_blk.m_num_partitions);

		const uint32_t num_comps = log_blk.get_num_comps();

		pEndpoints[0].a = 255;
		pEndpoints[1].a = 255;

		for (uint32_t e = 0; e < 2; e++)
		{
			for (uint32_t c = 0; c < num_comps; c++)
			{
				if (log_blk.m_num_pbits)
					pEndpoints[e][c] = (uint8_t)bc7_dequant(log_blk.m_endpoints[subset][e][c], log_blk.m_pbits[log_blk.m_shared_pbits ? subset : (subset * 2 + e)], log_blk.m_endpoint_bits[c == 3]);
				else
					pEndpoints[e][c] = (uint8_t)bc7_dequant(log_blk.m_endpoints[subset][e][c], log_blk.m_endpoint_bits[c == 3]);
			} // c
		} // e 
	}

	const endpoint_format g_endpoint_formats[8] =
	{
		{ 4, 0, 2 }, // 0 (unique pbits)
		{ 6, 0, 1 }, // 1 (shared pbits)
		{ 5, 0, 0 }, // 2
		{ 7, 0, 2 }, // 3 (unique pbits)

		{ 5, 6, 0 }, // 4
		{ 7, 8, 0 }, // 5
		{ 7, 7, 2 }, // 6 (unique pbits)
		{ 5, 5, 2 }  // 7 (unique pbits)
	};

	// Important note: Uses float math
	void pack_endpoints(
		uint32_t mode_index,
		const color_rgba pSrc_endpoints[2],
		color_rgba pDst_endpoints[2], uint8_t pDst_pbits[2])
	{
		assert(mode_index < 8);
		const auto& fmt = g_endpoint_formats[mode_index];

		const uint32_t num_rgb_bits = fmt.m_num_rgb_bits, num_a_bits = fmt.m_num_a_bits, num_pbits = fmt.m_num_pbits;
		const uint32_t num_comps = num_a_bits ? 4 : 3;

		const float S = 1.0f / 255.0f;

		float xl[4], xh[4];
		for (uint32_t c = 0; c < 4; c++)
		{
			xl[c] = (float)pSrc_endpoints[0][c] * S;
			xh[c] = (float)pSrc_endpoints[1][c] * S;
		}

		if (num_pbits == 0)
		{
			const float rgb_scale = (float)((1 << num_rgb_bits) - 1);
			const float a_scale = (float)((1 << num_a_bits) - 1);

			for (uint32_t c = 0; c < 4; c++)
			{
				const float scale = (c == 3) ? a_scale : rgb_scale;

				pDst_endpoints[0][c] = (uint8_t)basisu::clamp<int>(fast_roundf_int(xl[c] * scale), 0, 255);
				pDst_endpoints[1][c] = (uint8_t)basisu::clamp<int>(fast_roundf_int(xh[c] * scale), 0, 255);
			}

			pDst_pbits[0] = 0;
			pDst_pbits[1] = 0;
		}
		else if (num_pbits == 1)
		{
			assert(mode_index == 1);

			color_rgba bestMinColor, bestMaxColor;
			uint32_t best_pbits[2] = {};

			bc7f::determine_shared_pbits(num_comps, num_rgb_bits, xl, xh, bestMinColor, bestMaxColor, best_pbits); // always 3 comps

			for (uint32_t c = 0; c < 4; c++)
			{
				pDst_endpoints[0][c] = bestMinColor[c];
				pDst_endpoints[1][c] = bestMaxColor[c];
			}
			pDst_pbits[0] = (uint8_t)best_pbits[0];
			pDst_pbits[1] = (uint8_t)best_pbits[0];
		}
		else
		{
			assert(num_pbits == 2);

			color_rgba bestMinColor, bestMaxColor;
			uint32_t best_pbits[2] = {};

			bc7f::determine_unique_pbits(num_comps, num_rgb_bits, xl, xh, bestMinColor, bestMaxColor, best_pbits);

			for (uint32_t c = 0; c < 4; c++)
			{
				pDst_endpoints[0][c] = bestMinColor[c];
				pDst_endpoints[1][c] = bestMaxColor[c];
			}

			pDst_pbits[0] = (uint8_t)best_pbits[0];
			pDst_pbits[1] = (uint8_t)best_pbits[1];
		}
	}

	// Quantize an 8-bit value to a (comp_bits+1)-bit BC7 endpoint lattice
	// point with parity p (the pbit), round to nearest. 
	static inline int quant_endpoint_pbit(uint32_t v8, int p, int iscalep)
	{
		const int k = ((int)v8 * iscalep + 255 - 255 * p) / 510;
		return basisu::clamp<int>(k * 2 + p, p, iscalep - 1 + p);
	}

	// No-pbit modes (2, 4, 5): round-to-nearest into the field range.
	// Exact rational form of fast_roundf_int(v/255 * maxv).
	static inline uint32_t quant_endpoint(uint32_t v8, uint32_t num_bits)
	{
		const uint32_t maxv = (1u << num_bits) - 1u;
		return (v8 * maxv * 2u + 255u) / 510u;
	}

	// Exact integer determine_unique_pbits.
	static inline void determine_unique_pbits_int(
		uint32_t total_comps, uint32_t comp_bits, const uint8_t xl[4], const uint8_t xh[4],
		color_rgba& bestMinColor, color_rgba& bestMaxColor, uint32_t best_pbits[2])
	{
		const uint32_t total_bits = comp_bits + 1;
		const int iscalep = (1 << total_bits) - 1;

		uint64_t best_err0 = UINT64_MAX, best_err1 = UINT64_MAX;

		for (int p = 0; p < 2; p++)
		{
			int xMin[4], xMax[4], sL[4], sH[4];

			for (uint32_t c = 0; c < 4; c++)
			{
				xMin[c] = quant_endpoint_pbit(xl[c], p, iscalep);
				xMax[c] = quant_endpoint_pbit(xh[c], p, iscalep);
								
				sL[c] = (xMin[c] << (8 - total_bits)); sL[c] |= (sL[c] >> total_bits);
				sH[c] = (xMax[c] << (8 - total_bits)); sH[c] |= (sH[c] >> total_bits);
			}

			uint64_t err0 = 0, err1 = 0;
			for (uint32_t i = 0; i < total_comps; i++)
			{
				const int64_t d0 = sL[i] - (int)xl[i], d1 = sH[i] - (int)xh[i];
				err0 += (uint64_t)(d0 * d0);
				err1 += (uint64_t)(d1 * d1);
			}

			if (err0 < best_err0)
			{
				best_err0 = err0;
				best_pbits[0] = (uint32_t)p;
				for (uint32_t j = 0; j < 4; j++)
					bestMinColor[j] = (uint8_t)(xMin[j] >> 1);
			}

			if (err1 < best_err1)
			{
				best_err1 = err1;
				best_pbits[1] = (uint32_t)p;
				for (uint32_t j = 0; j < 4; j++)
					bestMaxColor[j] = (uint8_t)(xMax[j] >> 1);
			}
		}
	}

	// Exact integer determine_shared_pbits; same notes as above.
	static inline void determine_shared_pbits_int(
		uint32_t total_comps, uint32_t comp_bits, const uint8_t xl[4], const uint8_t xh[4],
		color_rgba& bestMinColor, color_rgba& bestMaxColor, uint32_t best_pbits[2])
	{
		const uint32_t total_bits = comp_bits + 1;
		const int iscalep = (1 << total_bits) - 1;

		uint64_t best_err = UINT64_MAX;

		for (int p = 0; p < 2; p++)
		{
			int xMin[4], xMax[4], sL[4], sH[4];

			for (uint32_t c = 0; c < 4; c++)
			{
				xMin[c] = quant_endpoint_pbit(xl[c], p, iscalep);
				xMax[c] = quant_endpoint_pbit(xh[c], p, iscalep);

				sL[c] = (xMin[c] << (8 - total_bits)); sL[c] |= (sL[c] >> total_bits);
				sH[c] = (xMax[c] << (8 - total_bits)); sH[c] |= (sH[c] >> total_bits);
			}

			uint64_t err = 0;
			for (uint32_t i = 0; i < total_comps; i++)
			{
				const int64_t d0 = sL[i] - (int)xl[i], d1 = sH[i] - (int)xh[i];
				err += (uint64_t)(d0 * d0 + d1 * d1);
			}

			if (err < best_err)
			{
				best_err = err;
				best_pbits[0] = (uint32_t)p;
				best_pbits[1] = (uint32_t)p;
				for (uint32_t j = 0; j < 4; j++)
				{
					bestMinColor[j] = (uint8_t)(xMin[j] >> 1);
					bestMaxColor[j] = (uint8_t)(xMax[j] >> 1);
				}
			}
		}
	}

	// Deterministic pack_endpoints: same shape as pack_endpoints() except all
	// integer (no float math at all). Used to requantize a predictor block's dequantized 8-bit RGBA
	// endpoints into the current block's mode format for endpoint DPCM.
	static inline void pack_endpoints_int(
		uint32_t mode_index,
		const color_rgba pSrc_endpoints[2], // 8-bit (unpacked)
		color_rgba pDst_endpoints[2], uint8_t pDst_pbits[2])
	{
		assert(mode_index < 8);
		const basist::bc7u::endpoint_format& fmt = basist::bc7u::g_endpoint_formats[mode_index];

		const uint32_t num_comps = fmt.m_num_a_bits ? 4 : 3;

		pDst_pbits[0] = 0;
		pDst_pbits[1] = 0;

		if (fmt.m_num_pbits == 0)
		{
			for (uint32_t e = 0; e < 2; e++)
			{
				for (uint32_t c = 0; c < 4; c++)
				{
					const uint32_t nbits = (c == 3) ? fmt.m_num_a_bits : fmt.m_num_rgb_bits;
					pDst_endpoints[e][c] = (uint8_t)(nbits ? quant_endpoint(pSrc_endpoints[e][c], nbits) : 0);
				}
			}
		}
		else
		{
			uint8_t l8[4], h8[4];
			for (uint32_t c = 0; c < 4; c++)
			{
				l8[c] = pSrc_endpoints[0][c];
				h8[c] = pSrc_endpoints[1][c];
			}

			uint32_t pbits[2] = { 0, 0 };

			if (fmt.m_num_pbits == 1)
				determine_shared_pbits_int(num_comps, fmt.m_num_rgb_bits, l8, h8, pDst_endpoints[0], pDst_endpoints[1], pbits);
			else
				determine_unique_pbits_int(num_comps, fmt.m_num_rgb_bits, l8, h8, pDst_endpoints[0], pDst_endpoints[1], pbits);

			pDst_pbits[0] = (uint8_t)pbits[0];
			pDst_pbits[1] = (uint8_t)pbits[1];
		}
	}

	// No float math here
	void endpoint_dpcm(
		bool decode_flag,
		const log_bc7_block& predictor_log_blk, uint32_t predictor_subset_index, // the logical block we are predicting from
		log_bc7_block& log_blk, uint32_t subset_index, // the logical block which has the endpoint we want to code/decode
		uint8_t* pResiduals, uint32_t& num_residuals, uint8_t *pBits, uint32_t &num_pbits) // the DPCM encoded values, in RR, GG, BB, AA order
	{
		assert(predictor_log_blk.is_valid());
		assert(log_blk.is_valid());

		const uint32_t mode_index = log_blk.m_mode;
		assert(mode_index < 8);

		const auto& fmt = g_endpoint_formats[mode_index];

		color_rgba pred_endpoints[2];
		unpack_endpoints(predictor_log_blk, pred_endpoints, predictor_subset_index);

		if (predictor_log_blk.is_dual_plane())
		{
			// convert to plain RGBA (A=the channel in the 2nd plane, we need to undo that)

			const uint32_t pred_ccs_index = predictor_log_blk.get_color_component_selector();
						
			std::swap(pred_endpoints[0][pred_ccs_index], pred_endpoints[0][3]);
			std::swap(pred_endpoints[1][pred_ccs_index], pred_endpoints[1][3]); 
		}

		const int ccs_index = log_blk.get_color_component_selector();

		if (log_blk.is_dual_plane())
		{
			// Convert from plain RGBA - put the channel on the 2nd plane into A
			std::swap(pred_endpoints[0][ccs_index], pred_endpoints[0][3]);
			std::swap(pred_endpoints[1][ccs_index], pred_endpoints[1][3]);
		}

		// Now pack our predicted endpoints into the local block's domain
		color_rgba packed_endpoints[2];
		uint8_t packed_pbits[2];
		pack_endpoints_int(log_blk.m_mode, pred_endpoints, packed_endpoints, packed_pbits);

		const uint32_t num_comps = log_blk.get_num_comps(); // 3 or 4

		num_residuals = num_comps * 2;
		num_pbits = fmt.m_num_pbits; // num pbits per subset
		assert(num_pbits * log_blk.m_num_partitions == log_blk.m_num_pbits);
				
		// subtract G from RB to mostly decorrelate (G unmodified) - but first, determine where G and A actually are taking into account dual plane modes
		int g_channel = 1, a_channel = 3;
		if (log_blk.is_dual_plane())
		{
			assert(num_comps == 4);

			a_channel = ccs_index;

			if (ccs_index == 1)
				g_channel = 3;
		}
		else
		{
			assert(num_comps >= 3);
		}

		if (!decode_flag)
		{
			// Compute deltas
			for (uint32_t c = 0; c < num_comps; c++)
			{
				pResiduals[c * 2 + 0] = (uint8_t)(log_blk.m_endpoints[subset_index][0][c] - packed_endpoints[0][c]);
				pResiduals[c * 2 + 1] = (uint8_t)(log_blk.m_endpoints[subset_index][1][c] - packed_endpoints[1][c]);
			}

			for (uint32_t c = 0; c < num_comps; c++)
			{
				if (((int)c == g_channel) || ((int)c == a_channel))
					continue;

				pResiduals[c * 2 + 0] = (uint8_t)(pResiduals[c * 2 + 0] - pResiduals[g_channel * 2 + 0]);
				pResiduals[c * 2 + 1] = (uint8_t)(pResiduals[c * 2 + 1] - pResiduals[g_channel * 2 + 1]);
			}

			// Compute delta pbits
			for (uint32_t p = 0; p < num_pbits; p++)
			{
				pBits[p] = (log_blk.m_pbits[subset_index * num_pbits + p] - packed_pbits[p]) & 1;
			}
		}
		else
		{
			// Don't modify the originals
			assert((num_comps * 2) <= 8);

			uint8_t temp_residuals[8];
			memcpy(temp_residuals, pResiduals, num_comps * 2);

			for (uint32_t c = 0; c < num_comps; c++)
			{
				if (((int)c == g_channel) || ((int)c == a_channel))
					continue;

				temp_residuals[c * 2 + 0] = (uint8_t)(temp_residuals[c * 2 + 0] + temp_residuals[g_channel * 2 + 0]);
				temp_residuals[c * 2 + 1] = (uint8_t)(temp_residuals[c * 2 + 1] + temp_residuals[g_channel * 2 + 1]);
			}

			for (uint32_t c = 0; c < num_comps; c++)
			{
				const uint32_t num_bits = log_blk.m_endpoint_bits[c == 3];
				const uint32_t mask = (1 << num_bits) - 1;

				log_blk.m_endpoints[subset_index][0][c] = (uint8_t)((temp_residuals[c * 2 + 0] + packed_endpoints[0][c]) & mask);
				log_blk.m_endpoints[subset_index][1][c] = (uint8_t)((temp_residuals[c * 2 + 1] + packed_endpoints[1][c]) & mask);
			}

			for (uint32_t p = 0; p < num_pbits; p++)
			{
				log_blk.m_pbits[subset_index * num_pbits + p] = (pBits[p] + packed_pbits[p]) & 1;
			}
		}
	}

	void init_log_blk(log_bc7_block& log_blk, uint32_t mode)
	{
		log_blk.clear();

		const auto& fmt = g_endpoint_formats[mode];

		log_blk.m_mode = (int8_t)mode;

		log_blk.m_num_partitions = basist::g_bc7_num_subsets[mode];
		log_blk.m_num_planes = ((mode == 4) || (mode == 5)) ? 2 : 1;
		log_blk.m_num_pbits = log_blk.m_num_partitions * fmt.m_num_pbits;
		log_blk.m_pattern_bits = basist::g_bc7_partition_bits[mode];
		log_blk.m_endpoint_bits[0] = fmt.m_num_rgb_bits;
		log_blk.m_endpoint_bits[1] = fmt.m_num_a_bits;
		log_blk.m_weight_bits[0] = g_bc7_color_index_bitcount[mode];
		log_blk.m_weight_bits[1] = (log_blk.m_num_planes == 2) ? g_bc7_alpha_index_bitcount[mode] : 0;
		log_blk.m_shared_pbits = (fmt.m_num_pbits == 1);
	}

	void create_solid_blk(log_bc7_block& log_blk, const color_rgba& c)
	{
		init_log_blk(log_blk, 5);

		const uint32_t lr = basist::g_bc7_mode_5_optimal_endpoints[c[0]].m_lo;
		const uint32_t hr = basist::g_bc7_mode_5_optimal_endpoints[c[0]].m_hi;

		const uint32_t lg = basist::g_bc7_mode_5_optimal_endpoints[c[1]].m_lo;
		const uint32_t hg = basist::g_bc7_mode_5_optimal_endpoints[c[1]].m_hi;

		const uint32_t lb = basist::g_bc7_mode_5_optimal_endpoints[c[2]].m_lo;
		const uint32_t hb = basist::g_bc7_mode_5_optimal_endpoints[c[2]].m_hi;

		log_blk.m_endpoints[0][0][0] = (uint8_t)lr;
		log_blk.m_endpoints[0][1][0] = (uint8_t)hr;

		log_blk.m_endpoints[0][0][1] = (uint8_t)lg;
		log_blk.m_endpoints[0][1][1] = (uint8_t)hg;

		log_blk.m_endpoints[0][0][2] = (uint8_t)lb;
		log_blk.m_endpoints[0][1][2] = (uint8_t)hb;

		log_blk.m_endpoints[0][0][3] = c.a;
		log_blk.m_endpoints[0][1][3] = c.a;

		memset(log_blk.m_weights[0], 1, 16);
	}

	bool is_solid_blk(const log_bc7_block& log_blk)
	{
		assert(log_blk.is_valid());

		// we could check to see if each subset's endpoints are all equal too
		if (log_blk.m_num_partitions > 1)
			return false;

		for (uint32_t p = 0; p < log_blk.m_num_planes; p++)
		{
			for (uint32_t w = 1; w < 16; w++)
				if (log_blk.m_weights[p][0] != log_blk.m_weights[p][w])
					return false;
		}

		return true;
	}

	bool validate_log_blk(const log_bc7_block& log_blk)
	{
		int mode = log_blk.m_mode;
		if ((mode < 0) || (mode > 7))
			return false;

		log_bc7_block temp_log_blk;
		init_log_blk(temp_log_blk, mode);

		if (log_blk.m_num_partitions != temp_log_blk.m_num_partitions)
			return false;
		if (log_blk.m_num_planes != temp_log_blk.m_num_planes)
			return false;
		if (log_blk.m_num_pbits != temp_log_blk.m_num_pbits)
			return false;
		if (log_blk.m_pattern_bits != temp_log_blk.m_pattern_bits)
			return false;
		if (log_blk.m_endpoint_bits[0] != temp_log_blk.m_endpoint_bits[0])
			return false;
		if (log_blk.m_endpoint_bits[1] != temp_log_blk.m_endpoint_bits[1])
			return false;
		if (log_blk.m_weight_bits[0] != temp_log_blk.m_weight_bits[0])
			return false;
		if (log_blk.m_weight_bits[1] != temp_log_blk.m_weight_bits[1])
			return false;
		if (log_blk.m_shared_pbits != temp_log_blk.m_shared_pbits)
			return false;

		if (log_blk.m_pattern_index >= (1u << log_blk.m_pattern_bits))
			return false;
		
		if (log_blk.m_num_planes == 2)
		{
			if (log_blk.m_dp_rotation_index >= 4)
				return false;
		}
		else
		{
			if (log_blk.m_dp_rotation_index > 0)
				return false;
		}

		for (uint32_t s = 0; s < log_blk.m_num_partitions; s++)
		{
			for (uint32_t e = 0; e < 2; e++)
			{
				for (uint32_t c = 0; c < 4; c++)
				{
					if (log_blk.m_endpoints[s][e][c] >= (1u << log_blk.m_endpoint_bits[c == 3]))
						return false;
				}
			}
		}

		for (uint32_t p = 0; p < log_blk.m_num_planes; p++)
		{
			const uint32_t total_weights = 1u << log_blk.m_weight_bits[p];

			for (uint32_t w = 0; w < 16; w++)
			{
				if (log_blk.m_weights[p][w] >= total_weights)
					return false;
			}
		}

		return true;
	}

	void set_endpoints(log_bc7_block& log_blk, uint32_t subset, const color_rgba pEndpoints[2], const uint8_t pbits[2])
	{
		assert(subset < log_blk.m_num_partitions);

		for (uint32_t e = 0; e < 2; e++)
		{
			for (uint32_t c = 0; c < 4; c++)
			{
				const uint32_t num_endpoint_bits = log_blk.m_endpoint_bits[c == 3];

				if (!num_endpoint_bits)
				{
					log_blk.m_endpoints[subset][e][c] = 0;
				}
				else
				{
					assert(pEndpoints[e][c] < (1u << num_endpoint_bits));
					log_blk.m_endpoints[subset][e][c] = pEndpoints[e][c];
				}
			}
		}

		if (log_blk.m_num_pbits)
		{
			const uint32_t num_pbits_per_subset = log_blk.get_num_pbits_per_subset();

			for (uint32_t p = 0; p < num_pbits_per_subset; p++)
			{
				assert(pbits[p] <= 1);
				log_blk.m_pbits[subset * num_pbits_per_subset + p] = pbits[p];
			}
		}
	}

	bool unpack_bc7(const log_bc7_block& log_blk, color_rgba* pPixels)
	{
		if (log_blk.m_mode < 0)
		{
			assert(0);
			memset((void *)pPixels, 0, sizeof(color_rgba) * 16);
			return false;
		}

		const uint32_t num_comps = log_blk.get_num_comps();

		color_rgba endpoints[3][2]; // [subset][color_index];
		
		for (uint32_t subset = 0; subset < log_blk.m_num_partitions; subset++)
			unpack_endpoints(log_blk, endpoints[subset], subset);

		for (uint32_t i = 0; i < 16; i++)
		{
			uint32_t subset = 0;

			if (log_blk.m_num_partitions == 2)
				subset = basist::g_bc7_partition2[log_blk.m_pattern_index * 16 + i];
			else if (log_blk.m_num_partitions == 3)
				subset = basist::g_bc7_partition3[log_blk.m_pattern_index * 16 + i];

			color_rgba res;
			
			for (uint32_t c = 0; c < 3; c++)
			{
				res[c] = (uint8_t)bc7_interp(endpoints[subset][0][c], endpoints[subset][1][c], 
					log_blk.m_weights[log_blk.m_mode4_index_selector][i], log_blk.m_weight_bits[log_blk.m_mode4_index_selector]);
			}

			res.a = 255;

			if (num_comps == 4)
			{
				if (log_blk.m_num_planes == 2)
				{
					res.a = (uint8_t)bc7_interp(endpoints[subset][0][3], endpoints[subset][1][3],
						log_blk.m_weights[1 - log_blk.m_mode4_index_selector][i], log_blk.m_weight_bits[1 - log_blk.m_mode4_index_selector]);
				}
				else
				{
					res.a = (uint8_t)bc7_interp(endpoints[subset][0][3], endpoints[subset][1][3],
						log_blk.m_weights[0][i], log_blk.m_weight_bits[0]);
				}
			}

			if (log_blk.m_dp_rotation_index)
				std::swap(res.m_comps[3], res.m_comps[log_blk.m_dp_rotation_index - 1]);

			pPixels[i] = res;
		}
	
		return true;
	}

	bool unpack_bc7_texel(const log_bc7_block& log_blk, color_rgba& pixel, uint32_t x, uint32_t y)
	{
		if (log_blk.m_mode < 0)
		{
			assert(0);
			pixel.clear();
			return false;
		}

		const uint32_t num_comps = log_blk.get_num_comps();

		const uint32_t i = x + y * 4;
		assert(i < 16);
				
		uint32_t subset = 0;

		if (log_blk.m_num_partitions == 2)
			subset = basist::g_bc7_partition2[log_blk.m_pattern_index * 16 + i];
		else if (log_blk.m_num_partitions == 3)
			subset = basist::g_bc7_partition3[log_blk.m_pattern_index * 16 + i];

		color_rgba endpoints[2];
		unpack_endpoints(log_blk, endpoints, subset);

		color_rgba res;

		for (uint32_t c = 0; c < 3; c++)
		{
			res[c] = (uint8_t)bc7_interp(endpoints[0][c], endpoints[1][c],
				log_blk.m_weights[log_blk.m_mode4_index_selector][i], log_blk.m_weight_bits[log_blk.m_mode4_index_selector]);
		}

		res.a = 255;

		if (num_comps == 4)
		{
			if (log_blk.m_num_planes == 2)
			{
				res.a = (uint8_t)bc7_interp(endpoints[0][3], endpoints[1][3],
					log_blk.m_weights[1 - log_blk.m_mode4_index_selector][i], log_blk.m_weight_bits[1 - log_blk.m_mode4_index_selector]);
			}
			else
			{
				res.a = (uint8_t)bc7_interp(endpoints[0][3], endpoints[1][3],
					log_blk.m_weights[0][i], log_blk.m_weight_bits[0]);
			}
		}

		if (log_blk.m_dp_rotation_index)
			std::swap(res.m_comps[3], res.m_comps[log_blk.m_dp_rotation_index - 1]);

		pixel = res;

		return true;
	}

	uint32_t get_texel_subset(log_bc7_block& log_blk, uint32_t x, uint32_t y)
	{
		const uint32_t i = x + y * 4;
		assert(i < 16);

		uint32_t subset = 0;

		if (log_blk.m_num_partitions == 2)
			subset = basist::g_bc7_partition2[log_blk.m_pattern_index * 16 + i];
		else if (log_blk.m_num_partitions == 3)
			subset = basist::g_bc7_partition3[log_blk.m_pattern_index * 16 + i];

		return subset;
	}

	// swaps endpoints and adjusts weights as needed to ensure endpoint 0 r+g+b+a < endpoint 1 r+g+b+a (we can do this safely as pack_bc7() will do the inverse as needed)
	void canonicalize_endpoints(log_bc7_block& log_blk)
	{
		assert(log_blk.is_valid());

		if (log_blk.m_num_planes > 1)
		{
			assert(log_blk.m_num_partitions == 1);
			assert(log_blk.m_num_pbits == 0);

			color_rgba e[2];
			unpack_endpoints(log_blk, e, 0);
						
			for (uint32_t p = 0; p < log_blk.m_num_planes; p++)
			{
				uint32_t l0 = 0, l1 = 0;

				for (uint32_t c = 0; c < 4; c++)
				{
					if (log_blk.get_endpoint_channel_weight_plane(c) == p)
					{
						l0 += e[0][c];
						l1 += e[1][c];
					}
				}

				if (l0 <= l1)
					continue;

				for (uint32_t c = 0; c < 4; c++)
				{
					if (log_blk.get_endpoint_channel_weight_plane(c) == p)
						std::swap(log_blk.m_endpoints[0][0][c], log_blk.m_endpoints[0][1][c]);
				}

				const uint32_t max_weight_val = log_blk.get_num_weight_vals(p) - 1;
				for (uint32_t w = 0; w < 16; w++)
					log_blk.m_weights[p][w] = (uint8_t)(max_weight_val - log_blk.m_weights[p][w]);
			}
		}
		else
		{
			const uint32_t num_comps = log_blk.get_num_comps();

			for (uint32_t s = 0; s < log_blk.m_num_partitions; s++)
			{
				color_rgba e[2];
				unpack_endpoints(log_blk, e, s);

				uint32_t l0 = 0, l1 = 0;
				for (uint32_t c = 0; c < num_comps; c++)
				{
					l0 += e[0][c];
					l1 += e[1][c];
				}

				if (l0 <= l1)
					continue;
				
				for (uint32_t c = 0; c < num_comps; c++)
					std::swap(log_blk.m_endpoints[s][0][c], log_blk.m_endpoints[s][1][c]);

				const uint32_t num_pbits_per_subset = log_blk.get_num_pbits_per_subset();
				if (num_pbits_per_subset == 2)
					std::swap(log_blk.m_pbits[s * 2 + 0], log_blk.m_pbits[s * 2 + 1]);

				const uint32_t max_weight_val = log_blk.get_num_weight_vals(0) - 1;
			
				if (log_blk.m_num_partitions == 1)
				{
					for (uint32_t w = 0; w < 16; w++)
						log_blk.m_weights[0][w] = (uint8_t)(max_weight_val - log_blk.m_weights[0][w]);
				}
				else
				{
					for (uint32_t w = 0; w < 16; w++)
					{
						const uint32_t texel_s = get_texel_subset(log_blk, w & 3, w >> 2);
						if (texel_s == s)
						{
							log_blk.m_weights[0][w] = (uint8_t)(max_weight_val - log_blk.m_weights[0][w]);
						}
					}
				}
			}
		}
	}

	// This function will invert endpoints/weights as needed to pack them to a physical BC7 block, which is always lossless in decoded pixel space (but NOT in the latent itself).
	bool pack_bc7(const log_bc7_block& log_blk, void* pPhys_block)
	{
		const int mode = log_blk.m_mode;

		if (mode < 0)
		{
			assert(0);
			memset(pPhys_block, 0, 16);
			return false;
		}

		switch (mode)
		{
		case 0:
		{
			uint32_t lr[3], lg[3], lb[3], hr[3], hg[3], hb[3];

			for (uint32_t s = 0; s < 3; s++)
			{
				lr[s] = log_blk.m_endpoints[s][0][0];
				lg[s] = log_blk.m_endpoints[s][0][1];
				lb[s] = log_blk.m_endpoints[s][0][2];
				hr[s] = log_blk.m_endpoints[s][1][0];
				hg[s] = log_blk.m_endpoints[s][1][1];
				hb[s] = log_blk.m_endpoints[s][1][2];
			}

			uint32_t pbits[6];
			for (uint32_t p = 0; p < 6; p++)
				pbits[p] = log_blk.m_pbits[p];

			bc7f::encode_mode0_rgb_block((uint8_t *)pPhys_block, log_blk.m_pattern_index, lr, lg, lb, hr, hg, hb, pbits, log_blk.m_weights[0]);

			break;
		}
		case 2:
		{
			uint32_t lr[3], lg[3], lb[3], hr[3], hg[3], hb[3];

			for (uint32_t s = 0; s < 3; s++)
			{
				lr[s] = log_blk.m_endpoints[s][0][0];
				lg[s] = log_blk.m_endpoints[s][0][1];
				lb[s] = log_blk.m_endpoints[s][0][2];
				hr[s] = log_blk.m_endpoints[s][1][0];
				hg[s] = log_blk.m_endpoints[s][1][1];
				hb[s] = log_blk.m_endpoints[s][1][2];
			}

			bc7f::encode_mode2_rgb_block((uint8_t*)pPhys_block, log_blk.m_pattern_index, lr, lg, lb, hr, hg, hb, log_blk.m_weights[0]);

			break;
		}
		case 1:
		{
			uint32_t lr[2], lg[2], lb[2], hr[2], hg[2], hb[2];

			for (uint32_t s = 0; s < 2; s++)
			{
				lr[s] = log_blk.m_endpoints[s][0][0];
				lg[s] = log_blk.m_endpoints[s][0][1];
				lb[s] = log_blk.m_endpoints[s][0][2];
				hr[s] = log_blk.m_endpoints[s][1][0];
				hg[s] = log_blk.m_endpoints[s][1][1];
				hb[s] = log_blk.m_endpoints[s][1][2];
			}

			bc7f::encode_mode1_rgb_block((uint8_t *)pPhys_block, log_blk.m_pattern_index, 
				lr, lg, lb, hr, hg, hb, log_blk.m_pbits[0], log_blk.m_pbits[1], log_blk.m_weights[0]);

			break;
		}
		case 3:
		{
			uint32_t lr[2], lg[2], lb[2], hr[2], hg[2], hb[2];

			for (uint32_t s = 0; s < 2; s++)
			{
				lr[s] = log_blk.m_endpoints[s][0][0];
				lg[s] = log_blk.m_endpoints[s][0][1];
				lb[s] = log_blk.m_endpoints[s][0][2];
				hr[s] = log_blk.m_endpoints[s][1][0];
				hg[s] = log_blk.m_endpoints[s][1][1];
				hb[s] = log_blk.m_endpoints[s][1][2];
			}

			uint32_t pbits[4];
			for (uint32_t p = 0; p < 4; p++)
				pbits[p] = log_blk.m_pbits[p];

			bc7f::encode_mode3_rgb_block((uint8_t*)pPhys_block, log_blk.m_pattern_index,
				lr, lg, lb, hr, hg, hb, pbits, log_blk.m_weights[0]);

			break;
		}
		case 4:
		{
			bc7f::encode_mode4_rgba_block((uint8_t *)pPhys_block, 
				log_blk.m_endpoints[0][0][0], log_blk.m_endpoints[0][0][1], log_blk.m_endpoints[0][0][2], log_blk.m_endpoints[0][0][3],
				log_blk.m_endpoints[0][1][0], log_blk.m_endpoints[0][1][1], log_blk.m_endpoints[0][1][2], log_blk.m_endpoints[0][1][3],
				log_blk.m_weights[log_blk.m_mode4_index_selector],  // it always wants the RGB weights first, then A
				log_blk.m_weights[1 - log_blk.m_mode4_index_selector],
				log_blk.m_dp_rotation_index, log_blk.m_mode4_index_selector);

			break;
		}
		case 5:
		{
			bc7f::encode_mode5_rgba_block((uint8_t*)pPhys_block,
				log_blk.m_endpoints[0][0][0], log_blk.m_endpoints[0][0][1], log_blk.m_endpoints[0][0][2], log_blk.m_endpoints[0][0][3],
				log_blk.m_endpoints[0][1][0], log_blk.m_endpoints[0][1][1], log_blk.m_endpoints[0][1][2], log_blk.m_endpoints[0][1][3],
				log_blk.m_weights[0], log_blk.m_weights[1], log_blk.m_dp_rotation_index);

			break;
		}
		case 6:
		{
			bc7f::encode_mode6_rgba_block((uint8_t*)pPhys_block,
				log_blk.m_endpoints[0][0][0], log_blk.m_endpoints[0][0][1], log_blk.m_endpoints[0][0][2], log_blk.m_endpoints[0][0][3], log_blk.m_pbits[0],
				log_blk.m_endpoints[0][1][0], log_blk.m_endpoints[0][1][1], log_blk.m_endpoints[0][1][2], log_blk.m_endpoints[0][1][3], log_blk.m_pbits[1],
				log_blk.m_weights[0]);

			break;
		}
		case 7:
		{
			uint32_t lr[2], lg[2], lb[2], la[2], hr[2], hg[2], hb[2], ha[2];

			for (uint32_t s = 0; s < 2; s++)
			{
				lr[s] = log_blk.m_endpoints[s][0][0];
				lg[s] = log_blk.m_endpoints[s][0][1];
				lb[s] = log_blk.m_endpoints[s][0][2];
				la[s] = log_blk.m_endpoints[s][0][3];

				hr[s] = log_blk.m_endpoints[s][1][0];
				hg[s] = log_blk.m_endpoints[s][1][1];
				hb[s] = log_blk.m_endpoints[s][1][2];
				ha[s] = log_blk.m_endpoints[s][1][3];
			}

			uint32_t pbits[4];
			for (uint32_t p = 0; p < 4; p++)
				pbits[p] = log_blk.m_pbits[p];

			bc7f::encode_mode7_rgba_block((uint8_t*)pPhys_block, log_blk.m_pattern_index,
				lr, lg, lb, la, hr, hg, hb, ha, pbits, log_blk.m_weights[0]);

			break;
		}
		default:
		{
			assert(0);
			break;
		}
		}

		return true;
	}

	bool compare_block_configs(const log_bc7_block& a, const log_bc7_block& b, bool compare_partition_index)
	{
		assert(a.is_valid() && b.is_valid());
		
		if ((!a.is_valid()) || (!b.is_valid()))
			return false;
		
		if (a.m_mode != b.m_mode)
			return false;
		
		// The logical blocks may not necessarily be BC7 compliant, so validate the rest of the config.
		if (a.m_num_partitions != b.m_num_partitions)
			return false;
				
		if (a.m_pattern_bits != b.m_pattern_bits)
			return false;

		if (compare_partition_index)
		{
			if (a.m_pattern_index != b.m_pattern_index)
				return false;
		}

		if (a.m_num_planes != b.m_num_planes)
			return false;

		if (a.m_dp_rotation_index != b.m_dp_rotation_index)
			return false;

		if (a.m_mode4_index_selector != b.m_mode4_index_selector)
			return false;

		if ((a.m_endpoint_bits[0] != b.m_endpoint_bits[0]) || (a.m_endpoint_bits[1] != b.m_endpoint_bits[1]))
			return false;

		if ((a.m_weight_bits[0] != b.m_weight_bits[0]) || (a.m_weight_bits[1] != b.m_weight_bits[1]))
			return false;

		if (a.m_num_pbits != b.m_num_pbits)
			return false;

		if (a.m_shared_pbits != b.m_shared_pbits)
			return false;

		return true;
	}

	bool compare_block_endpoints(const log_bc7_block& a, const log_bc7_block& b)
	{
		if (a.m_num_partitions != b.m_num_partitions)
			return false;
		
		if (a.m_endpoint_bits[0] != b.m_endpoint_bits[0])
			return false;

		if (a.m_endpoint_bits[1] != b.m_endpoint_bits[1])
			return false;

		for (uint32_t s = 0; s < a.m_num_partitions; s++)
		{
			for (uint32_t e = 0; e < 2; e++)
			{
				for (uint32_t c = 0; c < 4; c++)
				{
					if (a.m_endpoints[s][e][c] != b.m_endpoints[s][e][c])
						return false;
				} // c
			} // e
		} // s

		return true;
	}

	bool compare_block_pbits(const log_bc7_block& a, const log_bc7_block& b)
	{
		if (a.m_num_pbits != b.m_num_pbits)
			return false;

		if (a.m_shared_pbits != b.m_shared_pbits)
			return false;

		for (uint32_t p = 0; p < a.m_num_pbits; p++)
		{
			if (a.m_pbits[p] != b.m_pbits[p])
				return false;
		} // s

		return true;
	}

	bool compare_block_weights(const log_bc7_block& a, const log_bc7_block& b)
	{
		if (a.m_num_planes != b.m_num_planes)
			return false;
		
		if (a.m_weight_bits[0] != b.m_weight_bits[0])
			return false;
		if (a.m_weight_bits[1] != b.m_weight_bits[1])
			return false;

		for (uint32_t p = 0; p < a.m_num_planes; p++)
		{
			for (uint32_t w = 0; w < 16; w++)
			{
				if (a.m_weights[p][w] != b.m_weights[p][w])
					return false;
			} // w
		} // s

		return true;
	}

	bool compare_block_full(const log_bc7_block& a, const log_bc7_block& b)
	{
		if (!compare_block_configs(a, b))
			return false;

		if (!compare_block_endpoints(a, b))
			return false;

		if (!compare_block_pbits(a, b))
			return false;

		if (!compare_block_weights(a, b))
			return false;

		return true;
	}

} // namespace bc7u

namespace etc1f
{
#include "basisu_etc1_mods.inl"

	// flip 0:
	// 0011
	// 0011
	// 0011
	// 0011

	// flip 1:
	// 0000
	// 0000
	// 1111
	// 1111

	uint8_t g_nearest5[256], g_nearest4[256];

	const uint32_t NUM_SOLID_MODS = 4;

	uint8_t g_solid8_5_base[256][NUM_SOLID_MODS][4]; // [desired8][mod][sel]
	uint8_t g_solid8_5_err[256][NUM_SOLID_MODS][4];
	uint8_t g_solid8_4_base[256][NUM_SOLID_MODS][4];
	uint8_t g_solid8_4_err[256][NUM_SOLID_MODS][4];

	uint8_t g_solid_grayscale_etc1_blocks[256][8];

	inline int expand5(int v5)
	{
		return (v5 << 3) | (v5 >> 2);
	}

	inline int expand4(int v4)
	{
		return (v4 << 4) | v4;
	}

	static inline int dequant4(uint32_t v)
	{
		assert(v < 16);
		return (v << 4) | v;
	}

	static inline int dequant5(uint32_t v)
	{
		assert(v < 32);
		return (v << 3) | (v >> 2);
	}
	
	void init()
	{
		for (int i = 0; i < 256; i++)
		{
			int best_e = INT_MAX, best_idx = 0;

			for (int s = 0; s < 32; s++)
			{
				int recovered = (s << 3) | (s >> 2);
				int e = basisu::iabs(recovered - i);
				if (e < best_e)
				{
					best_e = e;
					best_idx = s;
				}
			}

			g_nearest5[i] = (uint8_t)best_idx;
		}

		for (int i = 0; i < 256; i++)
		{
			int best_e = INT_MAX, best_idx = 0;

			for (int s = 0; s < 16; s++)
			{
				int recovered = (s << 4) | s;
				int e = basisu::iabs(recovered - i);
				if (e < best_e)
				{
					best_e = e;
					best_idx = s;
				}
			}

			g_nearest4[i] = (uint8_t)best_idx;
		}

		for (uint32_t desired8 = 0; desired8 < 256; desired8++)
		{
			for (uint32_t mod = 0; mod < NUM_SOLID_MODS; mod++)
			{
				for (uint32_t sel = 0; sel < 4; sel++)
				{
					int32_t best_err = INT32_MAX;
					uint32_t best_base = 0;

					for (uint32_t b = 0; b < 32; b++)
					{
						int val = basisu::clamp(dequant5(b) + g_etc1_inten_tables[mod][sel], 0, 255);
						int err = basisu::iabs(val - desired8);

						if (err < best_err)
						{
							best_err = err;
							best_base = b;
							if (!best_err)
								break;
						}

					} // b

					g_solid8_5_base[desired8][mod][sel] = (uint8_t)best_base;
					g_solid8_5_err[desired8][mod][sel] = (uint8_t)basisu::minimum<uint32_t>(255, best_err * best_err);

				} // sel

			} // mod

		} // desired8

		for (uint32_t desired8 = 0; desired8 < 256; desired8++)
		{
			for (uint32_t mod = 0; mod < NUM_SOLID_MODS; mod++)
			{
				for (uint32_t sel = 0; sel < 4; sel++)
				{
					int32_t best_err = INT32_MAX;
					uint32_t best_base = 0;

					for (uint32_t b = 0; b < 16; b++)
					{
						int val = basisu::clamp(dequant4(b) + g_etc1_inten_tables[mod][sel], 0, 255);
						int err = basisu::iabs(val - desired8);

						if (err < best_err)
						{
							best_err = err;
							best_base = b;
							if (!best_err)
								break;
						}

					} // b

					g_solid8_4_base[desired8][mod][sel] = (uint8_t)best_base;
					g_solid8_4_err[desired8][mod][sel] = (uint8_t)basisu::minimum<uint32_t>(255, best_err * best_err);

				} // sel

			} // mod

		} // desired8

		pack_etc1_state pack_state;

		for (uint32_t i = 0; i <= 255; i++)
		{
			etc1f::pack_etc1_solid(&g_solid_grayscale_etc1_blocks[i][0], color_rgba(i, i, i, 255), pack_state, true);
		}
	}

	inline int dequant_d3(int8_t v)
	{
		assert(v <= 7);
		return (int8_t(v << 5) >> 5);
	}

	void get_block_colors(uint8_t* pBlock, color_rgba* pColors0, color_rgba* pColors1)
	{
		const uint32_t b0 = pBlock[0], b1 = pBlock[1], b2 = pBlock[2], b3 = pBlock[3];

		int base8_r[2], base8_g[2], base8_b[2];

		if (b3 & 2)
		{
			// diff mode
			base8_r[0] = dequant5(b0 >> 3);
			base8_r[1] = dequant5(basisu::clamp<int>((b0 >> 3) + dequant_d3(b0 & 7), 0, 31));

			base8_g[0] = dequant5(b1 >> 3);
			base8_g[1] = dequant5(basisu::clamp<int>((b1 >> 3) + dequant_d3(b1 & 7), 0, 31));

			base8_b[0] = dequant5(b2 >> 3);
			base8_b[1] = dequant5(basisu::clamp<int>((b2 >> 3) + dequant_d3(b2 & 7), 0, 31));
		}
		else
		{
			// abs mode
			base8_r[0] = dequant4(b0 >> 4);
			base8_r[1] = dequant4(b0 & 15);

			base8_g[0] = dequant4(b1 >> 4);
			base8_g[1] = dequant4(b1 & 15);

			base8_b[0] = dequant4(b2 >> 4);
			base8_b[1] = dequant4(b2 & 15);
		}

		const int* pInten_table0 = &g_etc1_inten_tables[b3 >> 5][0];
		const int* pInten_table1 = &g_etc1_inten_tables[(b3 >> 2) & 7][0];

		for (uint32_t i = 0; i < 4; i++)
		{
			const int d = pInten_table0[i];
			pColors0[i].r = (uint8_t)clamp255(base8_r[0] + d);
			pColors0[i].g = (uint8_t)clamp255(base8_g[0] + d);
			pColors0[i].b = (uint8_t)clamp255(base8_b[0] + d);
			pColors0[i].a = 0;
		}

		for (uint32_t i = 0; i < 4; i++)
		{
			const int d = pInten_table1[i];
			pColors1[i].r = (uint8_t)clamp255(base8_r[1] + d);
			pColors1[i].g = (uint8_t)clamp255(base8_g[1] + d);
			pColors1[i].b = (uint8_t)clamp255(base8_b[1] + d);
			pColors1[i].a = 0;
		}
	}

	void get_block_colors_y(uint8_t* pBlock, uint8_t* pColors0, uint8_t* pColors1)
	{
		//const uint32_t b0 = pBlock[0], b1 = pBlock[1], b2 = pBlock[2], b3 = pBlock[3];
		const uint32_t b0 = pBlock[0], b3 = pBlock[3];

		int base8_y[2];

		if (b3 & 2)
		{
			// diff mode
			base8_y[0] = dequant5(b0 >> 3);
			base8_y[1] = dequant5(basisu::clamp<int>((b0 >> 3) + dequant_d3(b0 & 7), 0, 31));
		}
		else
		{
			// abs mode
			base8_y[0] = dequant4(b0 >> 4);
			base8_y[1] = dequant4(b0 & 15);
		}

		const int* pInten_table0 = g_etc1_inten_tables[b3 >> 5];
		const int* pInten_table1 = g_etc1_inten_tables[(b3 >> 2) & 7];

		for (uint32_t i = 0; i < 4; i++)
		{
			const int d = pInten_table0[i];
			pColors0[i] = (uint8_t)clamp255(base8_y[0] + d);
		}

		for (uint32_t i = 0; i < 4; i++)
		{
			const int d = pInten_table1[i];
			pColors1[i] = (uint8_t)clamp255(base8_y[1] + d);
		}
	}

	static inline int q4_floor(int x) { return (x * 15) / 255; }
	static inline int q5_floor(int x) { return (x * 31) / 255; }

	void corr_round_555(int R, int G, int B, int& qR, int& qG, int& qB)
	{
		int rL = q5_floor(R), gL = q5_floor(G), bL = q5_floor(B);
		int rH = (rL < 31) ? (rL + 1) : 31;
		int gH = (gL < 31) ? (gL + 1) : 31;
		int bH = (bL < 31) ? (bL + 1) : 31;

		int r8[2] = { expand5(rL), expand5(rH) };
		int g8[2] = { expand5(gL), expand5(gH) };
		int b8[2] = { expand5(bL), expand5(bH) };

		int tr = r8[0], tg = g8[0], tb = b8[0];
		int eR = R - tr, eG = G - tg, eB = B - tb;
		int bestJ = basisu::squarei(eR - eG) + basisu::squarei(eG - eB) + basisu::squarei(eB - eR);
		int br = tr, bg = tg, bb = tb;

		for (int m = 1; m < 8; ++m)
		{
			tr = r8[m & 1], tg = g8[(m >> 1) & 1], tb = b8[(m >> 2) & 1];
			eR = R - tr, eG = G - tg, eB = B - tb;

			int J = basisu::squarei(eR - eG) + basisu::squarei(eG - eB) + basisu::squarei(eB - eR);
			if (J < bestJ)
			{
				bestJ = J;
				br = tr;
				bg = tg;
				bb = tb;
			}
		}

		qR = br >> 3; qG = bg >> 3; qB = bb >> 3;
	}

	void corr_round_444(int R, int G, int B, int& qR, int& qG, int& qB)
	{
		int rL = q4_floor(R), gL = q4_floor(G), bL = q4_floor(B);
		int rH = (rL < 15) ? (rL + 1) : 15;
		int gH = (gL < 15) ? (gL + 1) : 15;
		int bH = (bL < 15) ? (bL + 1) : 15;

		int r8[2] = { expand4(rL), expand4(rH) };
		int g8[2] = { expand4(gL), expand4(gH) };
		int b8[2] = { expand4(bL), expand4(bH) };

		int tr = r8[0], tg = g8[0], tb = b8[0];
		int eR = R - tr, eG = G - tg, eB = B - tb;
		int bestJ = basisu::squarei(eR - eG) + basisu::squarei(eG - eB) + basisu::squarei(eB - eR);
		int br = tr, bg = tg, bb = tb;

		for (int m = 1; m < 8; ++m)
		{
			tr = r8[m & 1], tg = g8[(m >> 1) & 1], tb = b8[(m >> 2) & 1];
			eR = R - tr, eG = G - tg, eB = B - tb;

			int J = basisu::squarei(eR - eG) + basisu::squarei(eG - eB) + basisu::squarei(eB - eR);
			if (J < bestJ)
			{
				bestJ = J;
				br = tr;
				bg = tg;
				bb = tb;
			}
		}

		qR = br >> 4; qG = bg >> 4; qB = bb >> 4;
	}

	inline bool quantize_444_color_correlated(int mean8_r, int mean8_g, int mean8_b, int enc_color[3], bool early_out = true)
	{
		// Floor to low 4-bit
		int r4_low = (mean8_r * 15) / 255;
		int g4_low = (mean8_g * 15) / 255;
		int b4_low = (mean8_b * 15) / 255;

		// High = +1, clamped
		int r4_high = basisu::clamp<int>(r4_low + 1, 0, 15);
		int g4_high = basisu::clamp<int>(g4_low + 1, 0, 15);
		int b4_high = basisu::clamp<int>(b4_low + 1, 0, 15);

		const int r8_low = expand4(r4_low);
		const int g8_low = expand4(g4_low);
		const int b8_low = expand4(b4_low);
		const int r8_high = expand4(r4_high);
		const int g8_high = expand4(g4_high);
		const int b8_high = expand4(b4_high);

		// Errors if we pick "low"
		const float dr = float(r8_low) - mean8_r;
		const float dg = float(g8_low) - mean8_g;
		const float db = float(b8_low) - mean8_b;

		const float dRG = fabsf(dr - dg);
		const float dRB = fabsf(dr - db);
		const float dGB = fabsf(dg - db);
		const float maxSpread = basisu::maximum(dRG, dRB, dGB);

		if ((early_out) && (maxSpread <= 1.0f))
			return false;

		// Step sizes low->high
		const float kr = float(r8_high - r8_low);
		const float kg = float(g8_high - g8_low);
		const float kb = float(b8_high - b8_low);

		// Precompute constants for cost(mask) = S0 + Lsum - Ksum^2
		const float D = dr + dg + db;
		const float S0 = 3.0f * (dr * dr + dg * dg + db * db) - D * D;

		const float Lr = 6.0f * dr * kr + 3.0f * kr * kr - 2.0f * D * kr;
		const float Lg = 6.0f * dg * kg + 3.0f * kg * kg - 2.0f * D * kg;
		const float Lb = 6.0f * db * kb + 3.0f * kb * kb - 2.0f * D * kb;

		float bestCost = basisu::BIG_FLOAT_VAL;
		int   bestMask = 0;

		for (int mask = 0; mask < 8; ++mask)
		{
			const float Ksum = ((mask & 1) ? kr : 0.0f) + ((mask & 2) ? kg : 0.0f) + ((mask & 4) ? kb : 0.0f);
			const float Lsum = ((mask & 1) ? Lr : 0.0f) + ((mask & 2) ? Lg : 0.0f) + ((mask & 4) ? Lb : 0.0f);

			const float cost = S0 + Lsum - Ksum * Ksum;

			if (cost < bestCost)
			{
				bestCost = cost;
				bestMask = mask;
			}
		}

		enc_color[0] = (bestMask & 1) ? r4_high : r4_low;
		enc_color[1] = (bestMask & 2) ? g4_high : g4_low;
		enc_color[2] = (bestMask & 4) ? b4_high : b4_low;

		assert((enc_color[0]) >= 0 && (enc_color[0] <= 15));
		assert((enc_color[1]) >= 0 && (enc_color[1] <= 15));
		assert((enc_color[2]) >= 0 && (enc_color[2] <= 15));

		return true;
	}

	void pack_etc1_solid(uint8_t* pBlock, const color_rgba& color, pack_etc1_state& state, bool init_flag)
	{
		uint32_t r8 = color[0], g8 = color[1], b8 = color[2];
		//const uint32_t r8 = 0, g8 = 0, b8 = 0;

		if (!init_flag)
		{
			if ((r8 == g8) && (r8 == b8))
			{
				memcpy(pBlock, &g_solid_grayscale_etc1_blocks[r8][0], sizeof(decoder_etc_block));
				return;
			}

			if ((state.m_prev_solid_r8 == (int)r8) && (state.m_prev_solid_g8 == (int)g8) && (state.m_prev_solid_b8 == (int)b8))
			{
				memcpy(pBlock, &state.m_prev_solid_block, sizeof(decoder_etc_block));
				return;
			}
		}

		uint32_t best_err = UINT32_MAX;
		uint32_t best_mod = 0, best_sel = 0;
		uint32_t best4_flag = false;

		const int RW = 2, GW = 4;

		for (uint32_t mod = 0; mod < NUM_SOLID_MODS; mod++)
		{
			for (uint32_t sel = 0; sel < 4; sel++)
			{
				uint32_t total_err5 = RW * g_solid8_5_err[r8][mod][sel] + GW * g_solid8_5_err[g8][mod][sel] + g_solid8_5_err[b8][mod][sel];
				if (total_err5 < best_err)
				{
					best_err = total_err5;
					best_mod = mod;
					best_sel = sel;
					best4_flag = false;
					if (!best_err)
						goto etc1_solid_done;
				}

				uint32_t total_err4 = RW * g_solid8_4_err[r8][mod][sel] + GW * g_solid8_4_err[g8][mod][sel] + g_solid8_4_err[b8][mod][sel];
				if (total_err4 < best_err)
				{
					best_err = total_err4;
					best_mod = mod;
					best_sel = sel;
					best4_flag = true;
				}

			} // sel
		} // mod

	etc1_solid_done:

		if (best4_flag)
		{
			const uint32_t best_base_r4 = g_solid8_4_base[r8][best_mod][best_sel];
			const uint32_t best_base_g4 = g_solid8_4_base[g8][best_mod][best_sel];
			const uint32_t best_base_b4 = g_solid8_4_base[b8][best_mod][best_sel];

			pBlock[0] = (uint8_t)(best_base_r4 | (best_base_r4 << 4));
			pBlock[1] = (uint8_t)(best_base_g4 | (best_base_g4 << 4));
			pBlock[2] = (uint8_t)(best_base_b4 | (best_base_b4 << 4));
		}
		else
		{
			pBlock[0] = (uint8_t)(g_solid8_5_base[r8][best_mod][best_sel] << 3);
			pBlock[1] = (uint8_t)(g_solid8_5_base[g8][best_mod][best_sel] << 3);
			pBlock[2] = (uint8_t)(g_solid8_5_base[b8][best_mod][best_sel] << 3);
		}

		const uint32_t flip = 0;
		const uint32_t diff = (best4_flag == 0);
		pBlock[3] = (uint8_t)(flip | (diff << 1) | (best_mod << 5) | (best_mod << 2));

		const uint32_t etc1_sels = g_selector_index_to_etc1[best_sel];

		const uint8_t lb = (etc1_sels & 2) ? 0xFF : 0;
		pBlock[4] = lb;
		pBlock[5] = lb;

		const uint8_t hb = (etc1_sels & 1) ? 0xFF : 0;
		pBlock[6] = hb;
		pBlock[7] = hb;

		state.m_prev_solid_r8 = r8;
		state.m_prev_solid_g8 = g8;
		state.m_prev_solid_b8 = b8;
		memcpy(&state.m_prev_solid_block, pBlock, sizeof(decoder_etc_block));
	}

	static const uint8_t s_vi[16] = { 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1 };
	static const uint8_t s_hi[16] = { 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3 };

	static const uint8_t s_subsets[2][16] =
	{
		{ 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1 },
		{ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1 }
	};

	// [flip][subblock][sel][l/h]
	static const uint16_t s_sel_bitmasks[2 * 2 * 4][2] =
	{
		// flip=0, subblock=0, sels=0-3
		{ 0xff, 0xff },
		{ 0x0, 0xff },
		{ 0x0, 0x0 },
		{ 0xff, 0x0 },

		// flip=0, subblock=1, sels=0-3
		{ 0xff00, 0xff00 },
		{ 0x0, 0xff00 },
		{ 0x0, 0x0 },
		{ 0xff00, 0x0 },

		// flip=1, subblock=0, sels=0-3
		{ 0x3333, 0x3333 },
		{ 0x0, 0x3333 },
		{ 0x0, 0x0 },
		{ 0x3333, 0x0 },

		// flip=1, subblock=1, sels=0-3
		{ 0xcccc, 0xcccc },
		{ 0x0, 0xcccc },
		{ 0x0, 0x0 },
		{ 0xcccc, 0x0 }
	};

	void pack_etc1_solid_subblocks(uint8_t* pBlock, const color_rgba* pPixels, const color_rgba subblock_means[2], uint32_t flip)
	{
		(void)pPixels;

		uint32_t best_mod5[2] = {}, best_sel5[2] = {};
		uint32_t best_base5[2][3] = {};
		uint32_t best_err5[2] = { UINT32_MAX, UINT32_MAX };

		uint32_t best_mod4[2] = {}, best_sel4[2] = {};
		uint32_t best_base4[2][3] = {};
		uint32_t best_err4[2] = { UINT32_MAX, UINT32_MAX };

		const int RW = 2, GW = 4;

		for (uint32_t t = 0; t < 2; t++)
		{
			const uint32_t r8 = subblock_means[t][0];
			const uint32_t g8 = subblock_means[t][1];
			const uint32_t b8 = subblock_means[t][2];

			const uint8_t* pR5 = &g_solid8_5_err[r8][0][0];
			const uint8_t* pG5 = &g_solid8_5_err[g8][0][0];
			const uint8_t* pB5 = &g_solid8_5_err[b8][0][0];

			const uint8_t* pR4 = &g_solid8_4_err[r8][0][0];
			const uint8_t* pG4 = &g_solid8_4_err[g8][0][0];
			const uint8_t* pB4 = &g_solid8_4_err[b8][0][0];

			for (uint32_t mod = 0; mod < NUM_SOLID_MODS; mod++)
			{
				const uint32_t mod4 = mod << 2;

				const uint32_t total_err5_0 = ((RW * pR5[0] + GW * pG5[0] + pB5[0]) << 5) + (mod4 + 0);
				const uint32_t total_err5_1 = ((RW * pR5[1] + GW * pG5[1] + pB5[1]) << 5) + (mod4 + 1);
				const uint32_t total_err5_2 = ((RW * pR5[2] + GW * pG5[2] + pB5[2]) << 5) + (mod4 + 2);
				const uint32_t total_err5_3 = ((RW * pR5[3] + GW * pG5[3] + pB5[3]) << 5) + (mod4 + 3);

				best_err5[t] = basisu::minimum(best_err5[t], basisu::minimum(total_err5_0, total_err5_1), basisu::minimum(total_err5_2, total_err5_3));

				const uint32_t total_err4_0 = ((RW * pR4[0] + GW * pG4[0] + pB4[0]) << 5) + (mod4 + 0);
				const uint32_t total_err4_1 = ((RW * pR4[1] + GW * pG4[1] + pB4[1]) << 5) + (mod4 + 1);
				const uint32_t total_err4_2 = ((RW * pR4[2] + GW * pG4[2] + pB4[2]) << 5) + (mod4 + 2);
				const uint32_t total_err4_3 = ((RW * pR4[3] + GW * pG4[3] + pB4[3]) << 5) + (mod4 + 3);

				best_err4[t] = basisu::minimum(best_err4[t], basisu::minimum(total_err4_0, total_err4_1), basisu::minimum(total_err4_2, total_err4_3));

				pR5 += 4; pG5 += 4; pB5 += 4;
				pR4 += 4; pG4 += 4; pB4 += 4;
			} // mod

			best_mod5[t] = (best_err5[t] >> 2) & 7;
			best_sel5[t] = best_err5[t] & 3;
			best_err5[t] >>= 5;

			best_mod4[t] = (best_err4[t] >> 2) & 7;
			best_sel4[t] = best_err4[t] & 3;
			best_err4[t] >>= 5;

			best_base5[t][0] = g_solid8_5_base[r8][best_mod5[t]][best_sel5[t]];
			best_base5[t][1] = g_solid8_5_base[g8][best_mod5[t]][best_sel5[t]];
			best_base5[t][2] = g_solid8_5_base[b8][best_mod5[t]][best_sel5[t]];

			best_base4[t][0] = g_solid8_4_base[r8][best_mod4[t]][best_sel4[t]];
			best_base4[t][1] = g_solid8_4_base[g8][best_mod4[t]][best_sel4[t]];
			best_base4[t][2] = g_solid8_4_base[b8][best_mod4[t]][best_sel4[t]];

		} // t

		uint32_t total_err4 = best_err4[0] + best_err4[1];
		uint32_t total_err5 = best_err5[0] + best_err5[1];

		bool use_abs = false;
		if (total_err4 < total_err5)
		{
			use_abs = true;
		}
		else
		{
			int delta_r = best_base5[1][0] - best_base5[0][0];
			int delta_g = best_base5[1][1] - best_base5[0][1];
			int delta_b = best_base5[1][2] - best_base5[0][2];

			if ((delta_r < -4) || (delta_r > 3) ||
				(delta_g < -4) || (delta_g > 3) ||
				(delta_b < -4) || (delta_b > 3))
			{
				use_abs = true;
			}
		}

		uint32_t* pBest_sels;

		if (use_abs)
		{
			pBlock[0] = (uint8_t)(best_base4[1][0] | (best_base4[0][0] << 4));
			pBlock[1] = (uint8_t)(best_base4[1][1] | (best_base4[0][1] << 4));
			pBlock[2] = (uint8_t)(best_base4[1][2] | (best_base4[0][2] << 4));

			const uint32_t diff = false;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (best_mod4[0] << 5) | (best_mod4[1] << 2));

			pBest_sels = best_sel4;
		}
		else
		{
			const int delta_r = (best_base5[1][0] - best_base5[0][0]) & 7;
			const int delta_g = (best_base5[1][1] - best_base5[0][1]) & 7;
			const int delta_b = (best_base5[1][2] - best_base5[0][2]) & 7;

			pBlock[0] = (uint8_t)(delta_r | (best_base5[0][0] << 3));
			pBlock[1] = (uint8_t)(delta_g | (best_base5[0][1] << 3));
			pBlock[2] = (uint8_t)(delta_b | (best_base5[0][2] << 3));

			const uint32_t diff = 1;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (best_mod5[0] << 5) | (best_mod5[1] << 2));

			pBest_sels = best_sel5;
		}

		uint16_t l_bitmask = 0, h_bitmask = 0;

		for (uint32_t subblock = 0; subblock < 2; subblock++)
		{
			uint32_t best_etc1_sel = pBest_sels[subblock];

			l_bitmask |= s_sel_bitmasks[flip * 8 + subblock * 4 + best_etc1_sel][0];
			h_bitmask |= s_sel_bitmasks[flip * 8 + subblock * 4 + best_etc1_sel][1];
		}

		pBlock[7] = (uint8_t)(l_bitmask);
		pBlock[6] = (uint8_t)(l_bitmask >> 8);
		pBlock[5] = (uint8_t)(h_bitmask);
		pBlock[4] = (uint8_t)(h_bitmask >> 8);
	}

	//------------------------------------------

	void pack_etc1(uint8_t* pBlock, const color_rgba* pPixels, pack_etc1_state& state)
	{
		{
			// Solid block check, ignoring alpha.
			const uint32_t fc = *(const uint32_t*)&pPixels[0] & BASISD_COLOR_RGBA_RGB_MASK;

			if (fc == (*(const uint32_t*)&pPixels[15] & BASISD_COLOR_RGBA_RGB_MASK))
			{
				int k;
				for (k = 1; k < 15; k++)
					if ((*(const uint32_t*)&pPixels[k] & BASISD_COLOR_RGBA_RGB_MASK) != fc)
						break;

				if (k == 15)
				{
					pack_etc1_solid(pBlock, pPixels[0], state, false);
					return;
				}
			}
		}

		// [0]=left, [1]=right, [2]=top, [3]=bottom
		int accum_y[4] = { 0 }, accum_y2[4] = { 0 }, accum_c2[4] = { 0 };
		int total_c2 = 0, max_c2 = 0;

		for (uint32_t i = 0; i < 16; i++)
		{
			int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;
			int rg = r - g, bg = b - g;

			int y = (r + g + b + 1) / 3;
			int y2 = y * y, c2 = rg * rg + bg * bg;

			total_c2 += c2;
			max_c2 = basisu::maximum(max_c2, c2);

			const int vi = s_vi[i], hi = s_hi[i];

			accum_y[vi] += y;
			accum_y2[vi] += y2;
			accum_c2[vi] += c2;

			accum_y[hi] += y;
			accum_y2[hi] += y2;
			accum_c2[hi] += c2;

		} // i

#if 1
		// sqrt(300/16)=~4.33
		const int CHROMA_ENERGY_SUM_THRESH = 300;
		const int CHROMA_ENERGY_MAX_THRESH = 32;
		if ((total_c2 < CHROMA_ENERGY_SUM_THRESH) && (max_c2 < CHROMA_ENERGY_MAX_THRESH))
		{
			//memset(pBlock, 0, 8);
			//return;

			uint8_t y_pixels[16];
			if (total_c2 == 0)
			{
				for (uint32_t i = 0; i < 16; i++)
					y_pixels[i] = pPixels[i].r;
			}
			else
			{
				for (uint32_t i = 0; i < 16; i++)
					y_pixels[i] = (uint8_t)pPixels[i].get_709_luma();
			}
			pack_etc1_grayscale(pBlock, y_pixels, state);
			return;
		}
#endif

		int var_y_scaled[4]; // scaled by x64 (8*8)
		for (uint32_t i = 0; i < 4; i++)
			var_y_scaled[i] = basisu::maximum(0, (accum_y2[i] << 3) - (accum_y[i] * accum_y[i])); // max not needed

		float std_luma[4], std_chroma[4];
		for (uint32_t i = 0; i < 4; i++)
		{
			std_luma[i] = sqrtf((float)var_y_scaled[i] * (1.0f / 64.0f));
			std_chroma[i] = sqrtf((float)accum_c2[i] * (1.0f / 8.0f));
		}

		const float LUMA_SCALE = 2, CHROMA_SCALE = 1;
		float flip0_score = (std_luma[0] + std_luma[1]) * LUMA_SCALE + (std_chroma[0] + std_chroma[1]) * CHROMA_SCALE;
		float flip1_score = (std_luma[2] + std_luma[3]) * LUMA_SCALE + (std_chroma[2] + std_chroma[3]) * CHROMA_SCALE;

		const uint32_t flip = flip1_score < flip0_score;

		int var8_y[2] = {}, mean8_y[2] = {}, mean8_r[2] = {}, mean8_g[2] = {}, mean8_b[2] = {};
		int min_y[2] = { INT_MAX, INT_MAX }, max_y[2] = { INT_MIN, INT_MIN };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int r = pPixels[i].r, g = pPixels[i].g, b = pPixels[i].b;
			const int y = (r + g + b + 1) / 3;

			const uint32_t s = s_subsets[flip][i];

			var8_y[s] += y * y;
			mean8_y[s] += y;

			mean8_r[s] += r;
			mean8_g[s] += g;
			mean8_b[s] += b;

			min_y[s] = basisu::minimum(min_y[s], y);
			max_y[s] = basisu::maximum(max_y[s], y);
		}

		//memset(pBlock, 0, sizeof(etc_block));
		//return;

		if (((max_y[0] - min_y[0]) < 8) && ((max_y[1] - min_y[1]) < 8))
		{
			color_rgba subblock_means[2] = {
				color_rgba((mean8_r[0] + 4) / 8, (mean8_g[0] + 4) / 8, (mean8_b[0] + 4) / 8, 255),
				color_rgba((mean8_r[1] + 4) / 8, (mean8_g[1] + 4) / 8, (mean8_b[1] + 4) / 8, 255),
			};

			if (subblock_means[0] == subblock_means[1])
				pack_etc1_solid(pBlock, subblock_means[0], state, false);
			else
				pack_etc1_solid_subblocks(pBlock, pPixels, subblock_means, flip);

			return;
		}

		//memset(pBlock, 0, sizeof(etc_block));
		//return;

		int half_span8_y[2];
		float stddev_y[2];

		for (uint32_t i = 0; i < 2; i++)
		{
			var8_y[i] = basisu::maximum<int>(0, (var8_y[i] << 3) - mean8_y[i] * mean8_y[i]);
			stddev_y[i] = std::sqrt(static_cast<float>(var8_y[i])) * (1.0f / 8.0f);

			mean8_y[i] = (mean8_y[i] + 4) >> 3;

			mean8_r[i] = (mean8_r[i] + 4) >> 3;
			mean8_g[i] = (mean8_g[i] + 4) >> 3;
			mean8_b[i] = (mean8_b[i] + 4) >> 3;

			half_span8_y[i] = basisu::maximum<int>(max_y[i] - mean8_y[i], mean8_y[i] - min_y[i]);
		}

		int stddev[2] =
		{
			basisu::clamp<int>((int)ceilf(9.0f * (stddev_y[0] / (float)basisu::maximum(1, half_span8_y[0]))) - 1, 0, 7),
			basisu::clamp<int>((int)ceilf(9.0f * (stddev_y[1] / (float)basisu::maximum(1, half_span8_y[1]))) - 1, 0, 7)
		};

		uint32_t mod_tab[2];
		for (uint32_t i = 0; i < 2; i++)
			mod_tab[i] = g_etc1_mod_tabs[basisu::clamp<int>(half_span8_y[i], 1, 255)][stddev[i]];

		int mean5_r[2], mean5_g[2], mean5_b[2];

		for (uint32_t i = 0; i < 2; i++)
		{
#if 1
			corr_round_555(mean8_r[i], mean8_g[i], mean8_b[i], mean5_r[i], mean5_g[i], mean5_b[i]);
#else
			mean5_r[i] = g_nearest5[mean8_r[i]];
			mean5_g[i] = g_nearest5[mean8_g[i]];
			mean5_b[i] = g_nearest5[mean8_b[i]];
#endif
		}

		int delta5_r = mean5_r[1] - mean5_r[0];
		int delta5_g = mean5_g[1] - mean5_g[0];
		int delta5_b = mean5_b[1] - mean5_b[0];

		const uint32_t z = (delta5_r + 4) | (delta5_g + 4) | (delta5_b + 4);
		bool use_abs_colors4 = z > 7;

		if (!use_abs_colors4)
		{
			assert((delta5_r >= -4) && (delta5_r <= 3));
			assert((delta5_g >= -4) && (delta5_g <= 3));
			assert((delta5_b >= -4) && (delta5_b <= 3));
		}

		if (use_abs_colors4)
		{
			int mean4_r[2], mean4_g[2], mean4_b[2];

			for (uint32_t i = 0; i < 2; i++)
			{
#if 1
				corr_round_444(mean8_r[i], mean8_g[i], mean8_b[i], mean4_r[i], mean4_g[i], mean4_b[i]);
#else
				mean4_r[i] = g_nearest4[mean8_r[i]];
				mean4_g[i] = g_nearest4[mean8_g[i]];
				mean4_b[i] = g_nearest4[mean8_b[i]];
#endif
			} // i

			pBlock[0] = (uint8_t)(mean4_r[1] | (mean4_r[0] << 4));
			pBlock[1] = (uint8_t)(mean4_g[1] | (mean4_g[0] << 4));
			pBlock[2] = (uint8_t)(mean4_b[1] | (mean4_b[0] << 4));

			const uint32_t diff = 0;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (mod_tab[0] << 5) | (mod_tab[1] << 2));
		}
		else
		{
			pBlock[0] = (uint8_t)((delta5_r & 7) | (mean5_r[0] << 3));
			pBlock[1] = (uint8_t)((delta5_g & 7) | (mean5_g[0] << 3));
			pBlock[2] = (uint8_t)((delta5_b & 7) | (mean5_b[0] << 3));

			const uint32_t diff = 1;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (mod_tab[0] << 5) | (mod_tab[1] << 2));
		}

		uint16_t l_bitmask = 0;
		uint16_t h_bitmask = 0;

		static const uint8_t s_tran[4] = { 1, 0, 2, 3 };

		color_rgba subblock_colors[2][4];
		get_block_colors(pBlock, &subblock_colors[0][0], &subblock_colors[1][0]);

		for (uint32_t subblock = 0; subblock < 2; subblock++)
		{
			const color_rgba* block_colors = &subblock_colors[subblock][0];

			uint32_t block_y[4];
			for (uint32_t i = 0; i < 4; i++)
				block_y[i] = block_colors[i][0] * 54 + block_colors[i][1] * 183 + block_colors[i][2] * 19;

			const uint32_t block_y01 = block_y[0] + block_y[1];
			const uint32_t block_y12 = block_y[1] + block_y[2];
			const uint32_t block_y23 = block_y[2] + block_y[3];

			if (flip)
			{
				uint32_t ofs = subblock * 2;

				for (uint32_t y = 0; y < 2; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						const color_rgba& c = pPixels[x + (subblock * 2 + y) * 4];
						const uint32_t l = c[0] * 108 + c[1] * 366 + c[2] * 38;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						ofs += 4;
					}

					ofs = (int)ofs + 1 - 4 * 4;
				}
			}
			else
			{
				uint32_t ofs = (subblock * 2) * 4;
				for (uint32_t x = 0; x < 2; x++)
				{
					for (uint32_t y = 0; y < 4; y++)
					{
						const color_rgba& c = pPixels[subblock * 2 + x + y * 4];
						const uint32_t l = c[0] * 108 + c[1] * 366 + c[2] * 38;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						++ofs;
					}
				}
			}

			pBlock[7] = (uint8_t)(l_bitmask);
			pBlock[6] = (uint8_t)(l_bitmask >> 8);
			pBlock[5] = (uint8_t)(h_bitmask);
			pBlock[4] = (uint8_t)(h_bitmask >> 8);

		} // subblock
	}

	void pack_etc1_grayscale_solid_subblocks(uint8_t* pBlock, const uint8_t* pPixels, const uint8_t subblock_means[2], uint32_t flip)
	{
		(void)pPixels;

		uint32_t best_mod5[2] = {}, best_sel5[2] = {};
		uint32_t best_base5[2] = {};
		uint32_t best_err5[2] = { UINT32_MAX, UINT32_MAX };

		uint32_t best_mod4[2] = {}, best_sel4[2] = {};
		uint32_t best_base4[2] = {};
		uint32_t best_err4[2] = { UINT32_MAX, UINT32_MAX };

		for (uint32_t t = 0; t < 2; t++)
		{
			const uint32_t y8 = subblock_means[t];

			const uint8_t* pY5 = &g_solid8_5_err[y8][0][0];
			const uint8_t* pY4 = &g_solid8_4_err[y8][0][0];

			for (uint32_t mod = 0; mod < NUM_SOLID_MODS; mod++)
			{
				const uint32_t mod4 = mod << 2;

				const uint32_t total_err5_0 = (pY5[0] << 5) + (mod4 + 0);
				const uint32_t total_err5_1 = (pY5[1] << 5) + (mod4 + 1);
				const uint32_t total_err5_2 = (pY5[2] << 5) + (mod4 + 2);
				const uint32_t total_err5_3 = (pY5[3] << 5) + (mod4 + 3);

				best_err5[t] = basisu::minimum(best_err5[t], basisu::minimum(total_err5_0, total_err5_1), basisu::minimum(total_err5_2, total_err5_3));

				const uint32_t total_err4_0 = (pY4[0] << 5) + (mod4 + 0);
				const uint32_t total_err4_1 = (pY4[1] << 5) + (mod4 + 1);
				const uint32_t total_err4_2 = (pY4[2] << 5) + (mod4 + 2);
				const uint32_t total_err4_3 = (pY4[3] << 5) + (mod4 + 3);

				best_err4[t] = basisu::minimum(best_err4[t], basisu::minimum(total_err4_0, total_err4_1), basisu::minimum(total_err4_2, total_err4_3));

				pY5 += 4;
				pY4 += 4;
			} // mod

			best_mod5[t] = (best_err5[t] >> 2) & 7;
			best_sel5[t] = best_err5[t] & 3;
			best_err5[t] >>= 5;

			best_mod4[t] = (best_err4[t] >> 2) & 7;
			best_sel4[t] = best_err4[t] & 3;
			best_err4[t] >>= 5;

			best_base5[t] = g_solid8_5_base[y8][best_mod5[t]][best_sel5[t]];

			best_base4[t] = g_solid8_4_base[y8][best_mod4[t]][best_sel4[t]];

		} // t

		uint32_t total_err4 = best_err4[0] + best_err4[1];
		uint32_t total_err5 = best_err5[0] + best_err5[1];

		bool use_abs = false;
		if (total_err4 < total_err5)
		{
			use_abs = true;
		}
		else
		{
			int delta_y = best_base5[1] - best_base5[0];

			if ((delta_y < -4) || (delta_y > 3))
			{
				use_abs = true;
			}
		}

		uint32_t* pBest_sels;

		if (use_abs)
		{
			pBlock[0] = pBlock[1] = pBlock[2] = (uint8_t)(best_base4[1] | (best_base4[0] << 4));

			const uint32_t diff = false;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (best_mod4[0] << 5) | (best_mod4[1] << 2));

			pBest_sels = best_sel4;
		}
		else
		{
			const int delta_y = (best_base5[1] - best_base5[0]) & 7;

			pBlock[0] = pBlock[1] = pBlock[2] = (uint8_t)(delta_y | (best_base5[0] << 3));

			const uint32_t diff = 1;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (best_mod5[0] << 5) | (best_mod5[1] << 2));

			pBest_sels = best_sel5;
		}

		uint16_t l_bitmask = 0, h_bitmask = 0;

		for (uint32_t subblock = 0; subblock < 2; subblock++)
		{
			uint32_t best_etc1_sel = pBest_sels[subblock];

			l_bitmask |= s_sel_bitmasks[flip * 8 + subblock * 4 + best_etc1_sel][0];
			h_bitmask |= s_sel_bitmasks[flip * 8 + subblock * 4 + best_etc1_sel][1];
		}

		pBlock[7] = (uint8_t)(l_bitmask);
		pBlock[6] = (uint8_t)(l_bitmask >> 8);
		pBlock[5] = (uint8_t)(h_bitmask);
		pBlock[4] = (uint8_t)(h_bitmask >> 8);
	}

	void pack_etc1_grayscale(uint8_t* pBlock, const uint8_t* pPixels, pack_etc1_state& state)
	{
		(void)state;

		const uint8_t fc = pPixels[0];

		if (fc == pPixels[15])
		{
			int k;
			for (k = 1; k < 15; k++)
				if (pPixels[k] != fc)
					break;

			if (k == 15)
			{
				memcpy(pBlock, &g_solid_grayscale_etc1_blocks[fc][0], sizeof(decoder_etc_block));
				return;
			}
		}

		int accum_y[4] = { 0 }, accum_y2[4] = { 0 };

		for (uint32_t i = 0; i < 16; i++)
		{
			int y = pPixels[i];
			int y2 = y * y;

			const int vi = s_vi[i], hi = s_hi[i];

			accum_y[vi] += y;
			accum_y2[vi] += y2;

			accum_y[hi] += y;
			accum_y2[hi] += y2;

		} // i

		int var_y_scaled[4]; // scaled by x64 (8*8)
		for (uint32_t i = 0; i < 4; i++)
			var_y_scaled[i] = basisu::maximum(0, (accum_y2[i] << 3) - (accum_y[i] * accum_y[i])); // max not needed

		float std_luma[4];
		for (uint32_t i = 0; i < 4; i++)
			std_luma[i] = sqrtf((float)var_y_scaled[i] * (1.0f / 64.0f));

		float flip0_score = std_luma[0] + std_luma[1];
		float flip1_score = std_luma[2] + std_luma[3];

		const uint32_t flip = flip1_score < flip0_score;

		int var8_y[2] = {}, mean8_y[2] = {};
		int min_y[2] = { INT_MAX, INT_MAX }, max_y[2] = { INT_MIN, INT_MIN };

		for (uint32_t i = 0; i < 16; i++)
		{
			const int y = pPixels[i];

			const uint32_t s = s_subsets[flip][i];

			var8_y[s] += y * y;
			mean8_y[s] += y;

			min_y[s] = basisu::minimum(min_y[s], y);
			max_y[s] = basisu::maximum(max_y[s], y);
		}

		if (((max_y[0] - min_y[0]) < 8) && ((max_y[1] - min_y[1]) < 8))
		{
			uint8_t subblock_means[2] = {
				(uint8_t)((mean8_y[0] + 4) / 8),
				(uint8_t)((mean8_y[1] + 4) / 8),
			};

			if (subblock_means[0] == subblock_means[1])
				memcpy(pBlock, &g_solid_grayscale_etc1_blocks[subblock_means[0]][0], sizeof(decoder_etc_block));
			else
				pack_etc1_grayscale_solid_subblocks(pBlock, pPixels, subblock_means, flip);

			return;
		}

		int half_span8_y[2];
		float stddev_y[2];

		for (uint32_t i = 0; i < 2; i++)
		{
			var8_y[i] = basisu::maximum<int>(0, (var8_y[i] << 3) - mean8_y[i] * mean8_y[i]);
			stddev_y[i] = std::sqrt(static_cast<float>(var8_y[i])) * (1.0f / 8.0f);

			mean8_y[i] = (mean8_y[i] + 4) >> 3;

			half_span8_y[i] = basisu::maximum<int>(max_y[i] - mean8_y[i], mean8_y[i] - min_y[i]);
		}

		int stddev[2] =
		{
			basisu::clamp<int>((int)ceilf(9.0f * (stddev_y[0] / (float)basisu::maximum(1, half_span8_y[0]))) - 1, 0, 7),
			basisu::clamp<int>((int)ceilf(9.0f * (stddev_y[1] / (float)basisu::maximum(1, half_span8_y[1]))) - 1, 0, 7)
		};

		uint32_t mod_tab[2];
		for (uint32_t i = 0; i < 2; i++)
			mod_tab[i] = etc1f::g_etc1_mod_tabs[basisu::clamp<int>(half_span8_y[i], 1, 255)][stddev[i]];

		int mean5_y[2];

		for (uint32_t i = 0; i < 2; i++)
			mean5_y[i] = g_nearest5[mean8_y[i]];

		int delta5_y = mean5_y[1] - mean5_y[0];

		const uint32_t z = delta5_y + 4;
		bool use_abs_colors4 = z > 7;

		if (!use_abs_colors4)
		{
			assert((delta5_y >= -4) && (delta5_y <= 3));
		}

		if (use_abs_colors4)
		{
			int mean4_y[2];

			for (uint32_t i = 0; i < 2; i++)
			{
				mean4_y[i] = g_nearest4[mean8_y[i]];
			} // i

			pBlock[0] = pBlock[1] = pBlock[2] = (uint8_t)(mean4_y[1] | (mean4_y[0] << 4));

			const uint32_t diff = 0;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (mod_tab[0] << 5) | (mod_tab[1] << 2));
		}
		else
		{
			pBlock[0] = pBlock[1] = pBlock[2] = (uint8_t)((delta5_y & 7) | (mean5_y[0] << 3));

			const uint32_t diff = 1;
			pBlock[3] = (uint8_t)(flip | (diff << 1) | (mod_tab[0] << 5) | (mod_tab[1] << 2));
		}

		//decoder_etc_block& blk = *(decoder_etc_block*)pBlock;

		uint16_t l_bitmask = 0;
		uint16_t h_bitmask = 0;

		static const uint8_t s_tran[4] = { 1, 0, 2, 3 };

		uint8_t subblock_colors[2][4];
		get_block_colors_y(pBlock, &subblock_colors[0][0], &subblock_colors[1][0]);

		for (uint32_t subblock = 0; subblock < 2; subblock++)
		{
			const uint8_t* block_y = &subblock_colors[subblock][0];

			//color_rgba block_colors[4];
			//blk.get_block_colors(block_colors, subblock);

			//uint32_t block_y[4];
			//for (uint32_t i = 0; i < 4; i++)
				//block_y[i] = block_colors[i];

			const uint32_t block_y01 = block_y[0] + block_y[1];
			const uint32_t block_y12 = block_y[1] + block_y[2];
			const uint32_t block_y23 = block_y[2] + block_y[3];

			if (flip)
			{
				uint32_t ofs = subblock * 2;

				for (uint32_t y = 0; y < 2; y++)
				{
					for (uint32_t x = 0; x < 4; x++)
					{
						const uint8_t c = pPixels[x + (subblock * 2 + y) * 4];
						const uint32_t l = c * 2;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						ofs += 4;
					}

					ofs = (int)ofs + 1 - 4 * 4;
				}
			}
			else
			{
				uint32_t ofs = (subblock * 2) * 4;
				for (uint32_t x = 0; x < 2; x++)
				{
					for (uint32_t y = 0; y < 4; y++)
					{
						const uint8_t c = pPixels[subblock * 2 + x + y * 4];
						const uint32_t l = c * 2;

						uint32_t t = s_tran[(l < block_y01) + (l < block_y12) + (l < block_y23)];

						assert(ofs < 16);
						l_bitmask |= ((t & 1) << ofs);
						h_bitmask |= ((t >> 1) << ofs);
						++ofs;
					}
				}
			}

			pBlock[7] = (uint8_t)(l_bitmask);
			pBlock[6] = (uint8_t)(l_bitmask >> 8);
			pBlock[5] = (uint8_t)(h_bitmask);
			pBlock[4] = (uint8_t)(h_bitmask >> 8);

		} // subblock
	}

} // namespace etc1f

#endif // BASISD_SUPPORT_XUASTC

//------------------------------------------------------------------------------------------------
// XUASTC LDR transcoding
//------------------------------------------------------------------------------------------------
// XUASTC adaptive deblocking threshold
//const int XUASTC_LDR_DEBLOCK_SKIP_THRESH = 24;

block_format xuastc_get_block_format(transcoder_texture_format tex_fmt)
{
	switch (tex_fmt)
	{
	case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA: return block_format::cASTC_LDR_4x4;
	case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA: return block_format::cASTC_LDR_5x4;
	case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA: return block_format::cASTC_LDR_5x5;
	case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA: return block_format::cASTC_LDR_6x5;
	case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA: return block_format::cASTC_LDR_6x6;
	case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA: return block_format::cASTC_LDR_8x5;
	case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA: return block_format::cASTC_LDR_8x6;
	case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA: return block_format::cASTC_LDR_10x5;
	case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA: return block_format::cASTC_LDR_10x6;
	case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA: return block_format::cASTC_LDR_8x8;
	case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA: return block_format::cASTC_LDR_10x8;
	case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA: return block_format::cASTC_LDR_10x10;
	case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA: return block_format::cASTC_LDR_12x10;
	case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA: return block_format::cASTC_LDR_12x12;
	default:
		break;
	}

	assert(0);
	return block_format::cASTC_LDR_4x4;
}

basisu_lowlevel_xuastc_ldr_transcoder::basisu_lowlevel_xuastc_ldr_transcoder()
{
}

#if BASISD_SUPPORT_XUASTC
bool transcode_4x4_block(
	block_format fmt, 
	uint32_t block_x, uint32_t block_y,
	void *pDst_blocks, uint8_t* pDst_block_u8,
	const color32* block_pixels,
	uint32_t output_block_or_pixel_stride_in_bytes, uint32_t output_row_pitch_in_blocks_or_pixels, uint32_t output_rows_in_pixels,
	int channel0, int channel1, 
	bool high_quality, bool from_alpha,
	uint32_t bc7f_flags,
	etc1f::pack_etc1_state& etc1_pack_state,
	int has_alpha) // has_alpha = -1 unknown, 0=definitely no (a all 255's), 1=potentially yes
{
	BASISU_NOTE_UNUSED(output_block_or_pixel_stride_in_bytes);

	switch (fmt)
	{
	case block_format::cETC1:
	{
		assert(output_block_or_pixel_stride_in_bytes == 8);
		if (from_alpha)
		{
			// Annoying overhead
			uint8_t alpha_pixels[16];
			for (uint32_t i = 0; i < 16; i++)
				alpha_pixels[i] = block_pixels[i].a;

			etc1f::pack_etc1_grayscale(pDst_block_u8, alpha_pixels, etc1_pack_state);
		}
		else
		{
			etc1f::pack_etc1(pDst_block_u8, (color_rgba *)block_pixels, etc1_pack_state);
		}
		break;
	}
	case block_format::cETC2_RGBA:
	{
		assert(output_block_or_pixel_stride_in_bytes == 16);

		(high_quality ? pack_eac_high_quality : pack_eac)(reinterpret_cast<eac_block*>(pDst_block_u8)[0], &block_pixels[0].c[3], sizeof(color32));
		etc1f::pack_etc1(pDst_block_u8 + 8, (color_rgba*)block_pixels, etc1_pack_state);

		break;
	}
	case block_format::cETC2_EAC_R11:
	{
		assert(output_block_or_pixel_stride_in_bytes == 8);

		// Pack R by default
		if (channel0 < 0)
			channel0 = 0;

		(high_quality ? pack_eac_high_quality : pack_eac)(reinterpret_cast<eac_block*>(pDst_block_u8)[0], &block_pixels[0].c[channel0], sizeof(color32));

		break;
	}
	case block_format::cETC2_EAC_RG11:
	{
		assert(output_block_or_pixel_stride_in_bytes == 16);

		// Pack RA by default
		if (channel0 < 0)
			channel0 = 0;
		if (channel1 < 0)
			channel1 = 3;

		(high_quality ? pack_eac_high_quality : pack_eac)(reinterpret_cast<eac_block*>(pDst_block_u8)[0], &block_pixels[0].c[channel0], sizeof(color32));
		(high_quality ? pack_eac_high_quality : pack_eac)(reinterpret_cast<eac_block*>(pDst_block_u8)[1], &block_pixels[0].c[channel1], sizeof(color32));

		break;
	}
	case block_format::cBC1:
	{
		assert(output_block_or_pixel_stride_in_bytes == 8);

		encode_bc1(pDst_block_u8, (const uint8_t *)block_pixels, high_quality ? cEncodeBC1HighQuality : 0);
		break;
	}
	case block_format::cBC3:
	{
		assert(output_block_or_pixel_stride_in_bytes == 16);

		encode_bc4(pDst_block_u8, &block_pixels[0].c[3], sizeof(color32));
		encode_bc1(pDst_block_u8 + 8, (const uint8_t *)block_pixels, high_quality ? cEncodeBC1HighQuality : 0);
		break;
	}
	case block_format::cBC4:
	{
		assert(output_block_or_pixel_stride_in_bytes == 8);

		// Pack R by default
		if (channel0 < 0)
			channel0 = 0;

		encode_bc4(pDst_block_u8, &block_pixels[0].c[channel0], sizeof(color32));
		break;
	}
	case block_format::cBC5:
	{
		assert(output_block_or_pixel_stride_in_bytes == 16);
		
		// Pack RA by default
		if (channel0 < 0)
			channel0 = 0;
		if (channel1 < 0)
			channel1 = 3;

		encode_bc4(pDst_block_u8, &block_pixels[0].c[channel0], sizeof(color32));
		encode_bc4(pDst_block_u8 + 8, &block_pixels[0].c[channel1], sizeof(color32));

		break;
	}
	case block_format::cBC7:
	{
		assert(output_block_or_pixel_stride_in_bytes == 16);
		
		// 0=definitely no alpha, so skip alpha checks
		if (has_alpha == 0) 
			bc7f::fast_pack_bc7_auto_rgb(pDst_block_u8, (const basist::color_rgba*)block_pixels, bc7f_flags);
		else
			bc7f::fast_pack_bc7_auto_rgba(pDst_block_u8, (const basist::color_rgba*)block_pixels, bc7f_flags);

		break;
	}
	case block_format::cRGBA32:
	{
		assert(sizeof(uint32_t) == output_block_or_pixel_stride_in_bytes);
		uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint32_t);

		const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
		const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

		if ((max_x == 4) && (max_y == 4))
		{
			memcpy(pDst_pixels, block_pixels, 4 * sizeof(color32));
			memcpy(pDst_pixels + output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t) * 1, &block_pixels[1 * 4], 4 * sizeof(color32));
			memcpy(pDst_pixels + output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t) * 2, &block_pixels[2 * 4], 4 * sizeof(color32));
			memcpy(pDst_pixels + output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t) * 3, &block_pixels[3 * 4], 4 * sizeof(color32));
		}
		else
		{
			for (uint32_t y = 0; y < max_y; y++)
			{
				memcpy(pDst_pixels, &block_pixels[y * 4], max_x * sizeof(color32));
				pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint32_t);
			}
		}

		break;
	}
	case block_format::cRGB565:
	case block_format::cBGR565:
	{
		// This writes little endian data always.
		assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
		uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

		const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
		const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

		for (uint32_t y = 0; y < max_y; y++)
		{
			for (uint32_t x = 0; x < max_x; x++)
			{
				const color32& c = block_pixels[y * 4 + x];

				const uint16_t packed = (fmt == block_format::cRGB565) ? static_cast<uint16_t>((mul_8(c.r, 31) << 11) | (mul_8(c.g, 63) << 5) | mul_8(c.b, 31)) :
					static_cast<uint16_t>((mul_8(c.b, 31) << 11) | (mul_8(c.g, 63) << 5) | mul_8(c.r, 31));
								
				pDst_pixels[x * 2 + 0] = (uint8_t)(packed & 0xFF);
				pDst_pixels[x * 2 + 1] = (uint8_t)((packed >> 8) & 0xFF);
			}

			pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
		}

		break;
	}
	case block_format::cRGBA4444:
	{
		// This writes little endian data always.
		assert(sizeof(uint16_t) == output_block_or_pixel_stride_in_bytes);
		uint8_t* pDst_pixels = static_cast<uint8_t*>(pDst_blocks) + (block_x * 4 + block_y * 4 * output_row_pitch_in_blocks_or_pixels) * sizeof(uint16_t);

		const uint32_t max_x = basisu::minimum<int>(4, (int)output_row_pitch_in_blocks_or_pixels - (int)block_x * 4);
		const uint32_t max_y = basisu::minimum<int>(4, (int)output_rows_in_pixels - (int)block_y * 4);

		for (uint32_t y = 0; y < max_y; y++)
		{
			for (uint32_t x = 0; x < max_x; x++)
			{
				const color32& c = block_pixels[y * 4 + x];

				const uint16_t packed = static_cast<uint16_t>((mul_8(c.r, 15) << 12) | (mul_8(c.g, 15) << 8) | (mul_8(c.b, 15) << 4) | mul_8(c.a, 15));

				pDst_pixels[x * 2 + 0] = (uint8_t)(packed & 0xFF);
				pDst_pixels[x * 2 + 1] = (uint8_t)((packed >> 8) & 0xFF);
			}

			pDst_pixels += output_row_pitch_in_blocks_or_pixels * sizeof(uint16_t);
		}
		break;
	}
	default:
		// Unsupported or invalid format
		assert(0);
		return false;
	}

	return true;
}

#if 0
static bool xuastc_deblock_filter(
	uint32_t filter_block_width, uint32_t filter_block_height, 
	const basisu::vector2D<color32> &src_img,
	basisu::vector2D<color32> &dst_img,
	bool stronger_filtering, int skip_thresh)
{
	basisu::vector2D<color32> temp_img;
	if (!temp_img.try_resize(src_img.get_width(), src_img.get_height()))
		return false;

	if (stronger_filtering)
		skip_thresh *= 2;

	//basisu::fmt_printf("stronger filtering: {}, skip_thread: {}\n", stronger_filtering, skip_thresh);

	temp_img = src_img;

	for (int y = 0; y < (int)src_img.get_height(); y++)
	{
		for (int x = filter_block_width; x < (int)src_img.get_width(); x += filter_block_width)
		{
			const color32 &ll = src_img.at_clamped(x - 2, y);
			const color32 &l = src_img.at_clamped(x - 1, y);
			const color32 &r =src_img.at_clamped(x, y);
			const color32 &rr = src_img.at_clamped(x + 1, y);

			if (skip_thresh < 256)
			{
				bool skip_flag = false;
				for (uint32_t c = 0; c < 4; c++)
				{
					int delta = basisu::iabs((int)l[c] - (int)r[c]);
					if (delta > skip_thresh)
					{
						skip_flag = true;
						break;
					}
				}

				if (skip_flag)
					continue;
			}

			color32 ml, mr;
			for (uint32_t c = 0; c < 4; c++)
			{
				if (stronger_filtering)
				{
					ml[c] = (3 * l[c] + 2 * r[c] + ll[c] + 3) / 6;
					mr[c] = (3 * r[c] + 2 * l[c] + rr[c] + 3) / 6;
				}
				else
				{
					ml[c] = (5 * l[c] + 2 * r[c] + ll[c] + 4) / 8;
					mr[c] = (5 * r[c] + 2 * l[c] + rr[c] + 4) / 8;
				}
			}

			temp_img.set_clipped(x - 1, y, ml);
			temp_img.set_clipped(x, y, mr);

		} // x

	} // y

	dst_img = temp_img;

	for (int x = 0; x < (int)temp_img.get_width(); x++)
	{
		for (int y = filter_block_height; y < (int)temp_img.get_height(); y += filter_block_height)
		{
			const color32 &uu = temp_img.at_clamped(x, y - 2);
			const color32 &u = temp_img.at_clamped(x, y - 1);
			const color32 &d = temp_img.at_clamped(x, y);
			const color32 &dd = temp_img.at_clamped(x, y + 1);

			if (skip_thresh < 256)
			{
				bool skip_flag = false;
				for (uint32_t c = 0; c < 4; c++)
				{
					int delta = basisu::iabs((int)u[c] - (int)d[c]);
					if (delta > skip_thresh)
					{
						skip_flag = true;
						break;
					}
				}

				if (skip_flag)
					continue;
			}

			color32 mu, md;
			for (uint32_t c = 0; c < 4; c++)
			{
				if (stronger_filtering)
				{
					mu[c] = (3 * u[c] + 2 * d[c] + uu[c] + 3) / 6;
					md[c] = (3 * d[c] + 2 * u[c] + dd[c] + 3) / 6;
				}
				else
				{
					mu[c] = (5 * u[c] + 2 * d[c] + uu[c] + 4) / 8;
					md[c] = (5 * d[c] + 2 * u[c] + dd[c] + 4) / 8;
				}
			}

			dst_img.set_clipped(x, y - 1, mu);
			dst_img.set_clipped(x, y, md);

		} // x

	} // y

	return true;
}
#endif

static inline int fast_roundf_pos_int(float x)
{
	assert(x >= 0.0f);
	return (int)(x + 0.5f);
}

static void deblock_block_region_interior(int fbw, int fbh, const basisu::vector2D<basist::color32>& src_img, int bx, int by, basisu::vector2D<basist::color32>& dst_tile, int dst_x, int dst_y)
{
	assert((bx >= 0) && (bx < (int)src_img.get_width()));
	assert((by >= 0) && (by < (int)src_img.get_height()));
	assert(fbw >= 3);
	assert(fbh >= 3);
	assert(&src_img != &dst_tile);
	assert(src_img.get_width() == dst_tile.get_width());
	assert(src_img.get_height() == dst_tile.get_height());

	const int x_left = bx;
	const int x_right = bx + fbw - 1;
	const int y_top = by;
	const int y_bottom = by + fbh - 1;

	// --- Four corners -------------------------------------------------------
	// Some results computed at float precision to more closely match the GPU shader.

#define BASISU_CORNER(SX, SY, TX, TY) do {                                                    \
		const basist::color32 h_l = src_img.get_clamped((SX) - 1, (SY));                      \
		const basist::color32 h_c = src_img.get_clamped((SX),     (SY));                      \
		const basist::color32 h_r = src_img.get_clamped((SX) + 1, (SY));                      \
		const basist::color32 v_u = src_img.get_clamped((SX), (SY) - 1);                      \
		const basist::color32 v_d = src_img.get_clamped((SX), (SY) + 1);                      \
                                                                                              \
		basist::color32 out;                                                                  \
		out.r = (uint8_t)basisu::minimum<int>(255, fast_roundf_pos_int(                       \
			(float)(h_l.r + 2 * h_c.r + h_r.r + v_u.r + v_d.r) * (1.0f / 6.0f)));             \
		out.g = (uint8_t)basisu::minimum<int>(255, fast_roundf_pos_int(                       \
			(float)(h_l.g + 2 * h_c.g + h_r.g + v_u.g + v_d.g) * (1.0f / 6.0f)));             \
		out.b = (uint8_t)basisu::minimum<int>(255, fast_roundf_pos_int(                       \
			(float)(h_l.b + 2 * h_c.b + h_r.b + v_u.b + v_d.b) * (1.0f / 6.0f)));             \
		out.a = (uint8_t)basisu::minimum<int>(255, fast_roundf_pos_int(                       \
			(float)(h_l.a + 2 * h_c.a + h_r.a + v_u.a + v_d.a) * (1.0f / 6.0f)));             \
		dst_tile.set_clipped((TX), (TY), out);                                                \
	} while (0)

	BASISU_CORNER(x_left, y_top, dst_x, dst_y);
	BASISU_CORNER(x_right, y_top, dst_x + fbw - 1, dst_y);
	BASISU_CORNER(x_left, y_bottom, dst_x, dst_y + fbh - 1);
	BASISU_CORNER(x_right, y_bottom, dst_x + fbw - 1, dst_y + fbh - 1);
#undef BASISU_CORNER

	// --- Top and Bottom edges: rows y_top and y_bottom, columns (x_left, x_right) exclusive.
	for (int sy = y_top; sy <= y_bottom; sy += (fbh - 1))
	{
		const int ty = dst_y + (sy - by);
		for (int tx_offset = 1; tx_offset < fbw - 1; tx_offset++)
		{
			const int sx = bx + tx_offset;
			const basist::color32 u = src_img.get_clamped(sx, sy - 1);
			const basist::color32 c = src_img.get_clamped(sx, sy);
			const basist::color32 d = src_img.get_clamped(sx, sy + 1);

			basist::color32 out;
			out.r = (uint8_t)(((uint32_t)u.r + (uint32_t)c.r + (uint32_t)d.r + 1u) / 3u);
			out.g = (uint8_t)(((uint32_t)u.g + (uint32_t)c.g + (uint32_t)d.g + 1u) / 3u);
			out.b = (uint8_t)(((uint32_t)u.b + (uint32_t)c.b + (uint32_t)d.b + 1u) / 3u);
			out.a = (uint8_t)(((uint32_t)u.a + (uint32_t)c.a + (uint32_t)d.a + 1u) / 3u);

			dst_tile.set_clipped(dst_x + tx_offset, ty, out);
		}
	}

	// --- Left and Right edges: columns x_left and x_right, rows (y_top, y_bottom) exclusive.
	for (int sx = x_left; sx <= x_right; sx += (fbw - 1))
	{
		const int tx = dst_x + (sx - bx);
		for (int ty_offset = 1; ty_offset < fbh - 1; ty_offset++)
		{
			const int sy = by + ty_offset;
			const basist::color32 l = src_img.get_clamped(sx - 1, sy);
			const basist::color32 c = src_img.get_clamped(sx, sy);
			const basist::color32 r = src_img.get_clamped(sx + 1, sy);

			basist::color32 out;
			out.r = (uint8_t)(((uint32_t)l.r + (uint32_t)c.r + (uint32_t)r.r + 1u) / 3u);
			out.g = (uint8_t)(((uint32_t)l.g + (uint32_t)c.g + (uint32_t)r.g + 1u) / 3u);
			out.b = (uint8_t)(((uint32_t)l.b + (uint32_t)c.b + (uint32_t)r.b + 1u) / 3u);
			out.a = (uint8_t)(((uint32_t)l.a + (uint32_t)c.a + (uint32_t)r.a + 1u) / 3u);

			dst_tile.set_clipped(tx, dst_y + ty_offset, out);
		}
	}

	// --- Interior: pass-through copy from source.
	// Fast path: interior fully in-bounds -> memcpy each row.
	const int interior_last_sx = bx + fbw - 2;
	const int interior_last_sy = by + fbh - 2;
	const bool interior_in_bounds =
		(interior_last_sx < (int)src_img.get_width()) &&
		(interior_last_sy < (int)src_img.get_height());

	if (interior_in_bounds)
	{
		const uint32_t bytes_per_row = (fbw - 2) * (uint32_t)sizeof(basist::color32);
		const uint32_t src_pitch = src_img.get_width();
		const uint32_t dst_pitch = dst_tile.get_width();

		for (int ty_offset = 1; ty_offset < (fbh - 1); ty_offset++)
		{
			const basist::color32* pSrc = src_img.get_ptr() + (bx + 1) + (by + ty_offset) * src_pitch;
			basist::color32* pDst = dst_tile.get_ptr() + (dst_x + 1) + (dst_y + ty_offset) * dst_pitch;
			memcpy(pDst, pSrc, bytes_per_row);
		}
	}
	else
	{
		for (int ty_offset = 1; ty_offset < (fbh - 1); ty_offset++)
		{
			const int sy = by + ty_offset;
			for (int tx_offset = 1; tx_offset < (fbw - 1); tx_offset++)
			{
				const int sx = bx + tx_offset;
				dst_tile.set_clipped(dst_x + tx_offset, dst_y + ty_offset, src_img.get_clamped(sx, sy));
			}
		}
	}
}

static bool xuastc_deblock_filter(
	uint32_t fbw, uint32_t fbh,
	const basisu::vector2D<color32>& src_img,
	basisu::vector2D<color32>& target_img)
{
	basisu::vector2D<color32> dst_img;
	dst_img.resize(src_img.get_width(), src_img.get_height());

	const uint32_t num_blocks_x = (src_img.get_width() + fbw - 1) / fbw;
	const uint32_t num_blocks_y = (src_img.get_height() + fbh - 1) / fbh;

	for (uint32_t by = 0; by < num_blocks_y; by++)
	{
		for (uint32_t bx = 0; bx < num_blocks_x; bx++)
		{
			deblock_block_region_interior(fbw, fbh,
				src_img, bx * (uint32_t)fbw, by * (uint32_t)fbh,
				dst_img, bx * (uint32_t)fbw, by * (uint32_t)fbh);
		} // bx
	} // by

	target_img.swap(dst_img);

	return true;
}

static void xuastc_fixup_pvrtc1_4_modulation_rgb(
	const basisu::vector2D<color32>& temp_image,
	const uint32_t* pPVRTC_endpoints,
	void* pDst_blocks,
	uint32_t num_blocks_x, uint32_t num_blocks_y, bool from_alpha)
{
	const uint32_t x_mask = num_blocks_x - 1;
	const uint32_t y_mask = num_blocks_y - 1;
	const uint32_t x_bits = basisu::total_bits(x_mask);
	const uint32_t y_bits = basisu::total_bits(y_mask);
	const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
	//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
	const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

	uint32_t block_index = 0;

	// really 3x3
	int e0[4][4], e1[4][4];

	for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
	{
		const uint32_t* pE_rows[3];

		for (int ey = 0; ey < 3; ey++)
		{
			int by = y + ey - 1;

			const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

			pE_rows[ey] = pE;

			for (int ex = 0; ex < 3; ex++)
			{
				int bx = 0 + ex - 1;

				const uint32_t e = pE[bx & x_mask];

				e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31;
				e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31;
			}
		}

		const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

		for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
		{
			color32 block_pixels[4][4];
			temp_image.extract_block_clamped(&block_pixels[0][0], x * 4, y * 4, 4, 4);

			if (from_alpha)
			{
				// Just set RGB to alpha to avoid adding complexity below.
				for (uint32_t i = 0; i < 16; i++)
				{
					const uint8_t a = ((color32*)block_pixels)[i].a;
					((color32*)block_pixels)[i].set(a, a, a, 255);
				}
			}

			const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

			uint32_t swizzled = x_swizzle | y_swizzle;
			if (num_blocks_x != num_blocks_y)
			{
				swizzled &= swizzle_mask;

				if (num_blocks_x > num_blocks_y)
					swizzled |= ((x >> min_bits) << (min_bits * 2));
				else
					swizzled |= ((y >> min_bits) << (min_bits * 2));
			}

			pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
			pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

			{
				const uint32_t ex = 2;
				int bx = x + ex - 1;
				bx &= x_mask;

#define BUT_DO_ROW(ey) \
				{ \
					const uint32_t e = pE_rows[ey][bx]; \
					e0[ex][ey] = (get_opaque_endpoint_l0(e) * 255) / 31; \
					e1[ex][ey] = (get_opaque_endpoint_l1(e) * 255) / 31; \
				}

				BUT_DO_ROW(0);
				BUT_DO_ROW(1);
				BUT_DO_ROW(2);
#undef BUT_DO_ROW
			}

			uint32_t mod = 0;

#define BUT_DO_PIX(lx, ly, w0, w1, w2, w3) \
			{ \
				int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
				int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
				int cl = (block_pixels[ly][lx].r + block_pixels[ly][lx].g + block_pixels[ly][lx].b) * 16; \
				int dl = cb_l - ca_l; \
				int vl = cl - ca_l; \
				int p = vl * 16; \
				if (ca_l > cb_l) { p = -p; dl = -dl; } \
				uint32_t m = 0; \
				if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
				if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
				if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
				mod |= m; \
			}

			{
				const uint32_t ex = 0, ey = 0;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				BUT_DO_PIX(0, 0, 4, 4, 4, 4);
				BUT_DO_PIX(1, 0, 2, 6, 2, 6);
				BUT_DO_PIX(0, 1, 2, 2, 6, 6);
				BUT_DO_PIX(1, 1, 1, 3, 3, 9);
			}

			{
				const uint32_t ex = 1, ey = 0;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				BUT_DO_PIX(2, 0, 8, 0, 8, 0);
				BUT_DO_PIX(3, 0, 6, 2, 6, 2);
				BUT_DO_PIX(2, 1, 4, 0, 12, 0);
				BUT_DO_PIX(3, 1, 3, 1, 9, 3);
			}

			{
				const uint32_t ex = 0, ey = 1;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				BUT_DO_PIX(0, 2, 8, 8, 0, 0);
				BUT_DO_PIX(1, 2, 4, 12, 0, 0);
				BUT_DO_PIX(0, 3, 6, 6, 2, 2);
				BUT_DO_PIX(1, 3, 3, 9, 1, 3);
			}

			{
				const uint32_t ex = 1, ey = 1;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				BUT_DO_PIX(2, 2, 16, 0, 0, 0);
				BUT_DO_PIX(3, 2, 12, 4, 0, 0);
				BUT_DO_PIX(2, 3, 12, 0, 4, 0);
				BUT_DO_PIX(3, 3, 9, 3, 3, 1);
			}
#undef BUT_DO_PIX

			pDst_block->m_modulation = mod;

			e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
			e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
			e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

			e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
			e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
			e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

		} // x
	} // y
}

static void xuastc_fixup_pvrtc1_4_modulation_rgba(
	const basisu::vector2D<color32>& temp_image,
	const uint32_t* pPVRTC_endpoints,
	void* pDst_blocks, uint32_t num_blocks_x, uint32_t num_blocks_y)
{
	const uint32_t x_mask = num_blocks_x - 1;
	const uint32_t y_mask = num_blocks_y - 1;
	const uint32_t x_bits = basisu::total_bits(x_mask);
	const uint32_t y_bits = basisu::total_bits(y_mask);
	const uint32_t min_bits = basisu::minimum(x_bits, y_bits);
	//const uint32_t max_bits = basisu::maximum(x_bits, y_bits);
	const uint32_t swizzle_mask = (1 << (min_bits * 2)) - 1;

	uint32_t block_index = 0;

	// really 3x3
	int e0[4][4], e1[4][4];

	for (int y = 0; y < static_cast<int>(num_blocks_y); y++)
	{
		const uint32_t* pE_rows[3];

		for (int ey = 0; ey < 3; ey++)
		{
			int by = y + ey - 1;

			const uint32_t* pE = &pPVRTC_endpoints[(by & y_mask) * num_blocks_x];

			pE_rows[ey] = pE;

			for (int ex = 0; ex < 3; ex++)
			{
				int bx = 0 + ex - 1;

				const uint32_t e = pE[bx & x_mask];

				e0[ex][ey] = get_endpoint_l8(e, 0);
				e1[ex][ey] = get_endpoint_l8(e, 1);
			}
		}

		const uint32_t y_swizzle = (g_pvrtc_swizzle_table[y >> 8] << 16) | g_pvrtc_swizzle_table[y & 0xFF];

		for (int x = 0; x < static_cast<int>(num_blocks_x); x++, block_index++)
		{
			color32 block_pixels[4][4];
			temp_image.extract_block_clamped(&block_pixels[0][0], x * 4, y * 4, 4, 4);

			const uint32_t x_swizzle = (g_pvrtc_swizzle_table[x >> 8] << 17) | (g_pvrtc_swizzle_table[x & 0xFF] << 1);

			uint32_t swizzled = x_swizzle | y_swizzle;
			if (num_blocks_x != num_blocks_y)
			{
				swizzled &= swizzle_mask;

				if (num_blocks_x > num_blocks_y)
					swizzled |= ((x >> min_bits) << (min_bits * 2));
				else
					swizzled |= ((y >> min_bits) << (min_bits * 2));
			}

			pvrtc4_block* pDst_block = static_cast<pvrtc4_block*>(pDst_blocks) + swizzled;
			pDst_block->m_endpoints = pPVRTC_endpoints[block_index];

			{
				const uint32_t ex = 2;
				int bx = x + ex - 1;
				bx &= x_mask;

#define DO_ROW(ey) \
					{ \
						const uint32_t e = pE_rows[ey][bx]; \
						e0[ex][ey] = get_endpoint_l8(e, 0); \
						e1[ex][ey] = get_endpoint_l8(e, 1); \
					}

				DO_ROW(0);
				DO_ROW(1);
				DO_ROW(2);
#undef DO_ROW
			}

			uint32_t mod = 0;

#define DO_PIX(lx, ly, w0, w1, w2, w3) \
				{ \
					int ca_l = a0 * w0 + a1 * w1 + a2 * w2 + a3 * w3; \
					int cb_l = b0 * w0 + b1 * w1 + b2 * w2 + b3 * w3; \
					int cl = 16 * (block_pixels[ly][lx].r + block_pixels[ly][lx].g + block_pixels[ly][lx].b + block_pixels[ly][lx].a); \
					int dl = cb_l - ca_l; \
					int vl = cl - ca_l; \
					int p = vl * 16; \
					if (ca_l > cb_l) { p = -p; dl = -dl; } \
					uint32_t m = 0; \
					if (p > 3 * dl) m = (uint32_t)(1 << ((ly) * 8 + (lx) * 2)); \
					if (p > 8 * dl) m = (uint32_t)(2 << ((ly) * 8 + (lx) * 2)); \
					if (p > 13 * dl) m = (uint32_t)(3 << ((ly) * 8 + (lx) * 2)); \
					mod |= m; \
				}

			{
				const uint32_t ex = 0, ey = 0;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				DO_PIX(0, 0, 4, 4, 4, 4);
				DO_PIX(1, 0, 2, 6, 2, 6);
				DO_PIX(0, 1, 2, 2, 6, 6);
				DO_PIX(1, 1, 1, 3, 3, 9);
			}

			{
				const uint32_t ex = 1, ey = 0;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				DO_PIX(2, 0, 8, 0, 8, 0);
				DO_PIX(3, 0, 6, 2, 6, 2);
				DO_PIX(2, 1, 4, 0, 12, 0);
				DO_PIX(3, 1, 3, 1, 9, 3);
			}

			{
				const uint32_t ex = 0, ey = 1;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				DO_PIX(0, 2, 8, 8, 0, 0);
				DO_PIX(1, 2, 4, 12, 0, 0);
				DO_PIX(0, 3, 6, 6, 2, 2);
				DO_PIX(1, 3, 3, 9, 1, 3);
			}

			{
				const uint32_t ex = 1, ey = 1;
				const int a0 = e0[ex][ey], a1 = e0[ex + 1][ey], a2 = e0[ex][ey + 1], a3 = e0[ex + 1][ey + 1];
				const int b0 = e1[ex][ey], b1 = e1[ex + 1][ey], b2 = e1[ex][ey + 1], b3 = e1[ex + 1][ey + 1];
				DO_PIX(2, 2, 16, 0, 0, 0);
				DO_PIX(3, 2, 12, 4, 0, 0);
				DO_PIX(2, 3, 12, 0, 4, 0);
				DO_PIX(3, 3, 9, 3, 3, 1);
			}
#undef DO_PIX

			pDst_block->m_modulation = mod;

			e0[0][0] = e0[1][0]; e0[1][0] = e0[2][0];
			e0[0][1] = e0[1][1]; e0[1][1] = e0[2][1];
			e0[0][2] = e0[1][2]; e0[1][2] = e0[2][2];

			e1[0][0] = e1[1][0]; e1[1][0] = e1[2][0];
			e1[0][1] = e1[1][1]; e1[1][1] = e1[2][1];
			e1[0][2] = e1[1][2]; e1[1][2] = e1[2][2];

		} // x
	} // y
}

void encode_pvrtc1(
	block_format fmt, void* pDst_blocks,
	const basisu::vector2D<color32> &temp_image,
	uint32_t dst_num_blocks_x, uint32_t dst_num_blocks_y, bool from_alpha)
{
	assert((fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA));

	basisu::vector2D<uint32_t> pvrtc1_endpoints(dst_num_blocks_x, dst_num_blocks_y);

	// Determine block endpoints
	for (uint32_t dst_by = 0; dst_by < dst_num_blocks_y; dst_by++)
	{
		for (uint32_t dst_bx = 0; dst_bx < dst_num_blocks_x; dst_bx++)
		{
			color32 block_pixels[4 * 4];

			temp_image.extract_block_clamped(block_pixels, dst_bx * 4, dst_by * 4, 4, 4);

			color32 low_color(255, 255, 255, 255), high_color(0, 0, 0, 0);

			for (uint32_t i = 0; i < 16; i++)
			{
				low_color = color32::comp_min(low_color, block_pixels[i]);
				high_color = color32::comp_max(high_color, block_pixels[i]);
			}

			if ((fmt == block_format::cPVRTC1_4_RGB) && (from_alpha))
			{
				low_color.set(low_color.a, low_color.a, low_color.a, 255);
				high_color.set(high_color.a, high_color.a, high_color.a, 255);
			}

			pvrtc4_block temp;
			if (fmt == block_format::cPVRTC1_4_RGBA)
			{
				temp.set_endpoint_floor(0, low_color);
				temp.set_endpoint_ceil(1, high_color);
			}
			else
			{
				temp.set_opaque_endpoint_floor(0, low_color);
				temp.set_opaque_endpoint_ceil(1, high_color);
			}

			pvrtc1_endpoints(dst_bx, dst_by) = temp.m_endpoints;
		} // dst_bx

	}  // dst_by

	// Create PVRTC1 texture data.
	if (fmt == block_format::cPVRTC1_4_RGBA)
		xuastc_fixup_pvrtc1_4_modulation_rgba(temp_image, pvrtc1_endpoints.get_ptr(), pDst_blocks, dst_num_blocks_x, dst_num_blocks_y);
	else
		xuastc_fixup_pvrtc1_4_modulation_rgb(temp_image, pvrtc1_endpoints.get_ptr(), pDst_blocks, dst_num_blocks_x, dst_num_blocks_y, from_alpha);
}

#endif // BASISD_SUPPORT_XUASTC

static inline bool blocks_same_solid_colors(const astc_helpers::log_astc_block& a, const astc_helpers::log_astc_block& b, uint32_t tol)
{
	if ((!a.m_solid_color_flag_ldr) || (!b.m_solid_color_flag_ldr))
		return false;

	if (tol == 0)
	{
		return (a.m_solid_color[0] == b.m_solid_color[0]) && (a.m_solid_color[1] == b.m_solid_color[1]) &&
			(a.m_solid_color[2] == b.m_solid_color[2]) && (a.m_solid_color[3] == b.m_solid_color[3]);
	}
	
	for (uint32_t i = 0; i < 4; i++)
	{
		int ac = a.m_solid_color[i] >> 8;
		int bc = b.m_solid_color[i] >> 8;
		
		const int dl = basisu::iabs((int)ac - (int)bc);
		if (dl > (int)tol)
			return false;
	}
	
	return true;
}

static inline bool blocks_same_single_subset_endpoints(const astc_helpers::log_astc_block& a, const astc_helpers::log_astc_block& b, uint32_t tol)
{
	if (a.m_solid_color_flag_ldr || b.m_solid_color_flag_ldr)
		return false;

	if (a.m_dual_plane || b.m_dual_plane)
		return false;

	if ((a.m_num_partitions > 1) || (b.m_num_partitions > 1))
		return false;

	if (a.m_color_endpoint_modes[0] != b.m_color_endpoint_modes[0])
		return false;
		
	if (a.m_endpoint_ise_range != b.m_endpoint_ise_range)
		return false;

	if (tol > 0)
	{
		// Compare endpoints with tolerance
		color_rgba al, ah;
		astc_ldr_t::decode_endpoints(a.m_color_endpoint_modes[0], a.m_endpoints, a.m_endpoint_ise_range, al, ah);

		color_rgba bl, bh;
		astc_ldr_t::decode_endpoints(b.m_color_endpoint_modes[0], b.m_endpoints, b.m_endpoint_ise_range, bl, bh);

		for (uint32_t i = 0; i < 4; i++)
		{
			const int dl = basisu::iabs((int)al[i] - (int)bl[i]);
			if (dl > (int)tol)
				return false;
			
			const int dh = basisu::iabs((int)ah[i] - (int)bh[i]);
			if (dh > (int)tol)
				return false;
		}
	}
	else
	{
		uint32_t total_endpoint_vals = astc_helpers::get_num_cem_values(a.m_color_endpoint_modes[0]);
		if (memcmp(a.m_endpoints, b.m_endpoints, total_endpoint_vals) != 0)
			return false;
	}

	return true;
}

static inline bool block_has_alpha(const astc_helpers::log_astc_block& a)
{
	if (a.m_solid_color_flag_ldr)
	{
		return (a.m_solid_color[3] >> 8) != 255;
	}

	assert(a.m_num_partitions == 1);

	return astc_helpers::does_cem_have_alpha(a.m_color_endpoint_modes[0]);
}

static void astc_upsample_grid_weights(const astc_helpers::log_astc_block& log_blk, uint8_t* pDst_weights, uint32_t block_width, uint32_t block_height)
{
	// Skip if solid (which is fine)
	if (log_blk.m_solid_color_flag_ldr)
	{
#if defined(DEBUG) || defined(_DEBUG)
		memset(pDst_weights, 0xFF, block_width * block_height);
#endif
		return;
	}
	
	assert((log_blk.m_grid_width <= block_width) && (log_blk.m_grid_height <= block_height));

	uint8_t dequantized_weights[astc_helpers::MAX_BLOCK_PIXELS];
	
	const uint32_t total_weight_vals = log_blk.m_grid_width * log_blk.m_grid_height;

	const astc_helpers::dequant_table& weight_dequant_tab = astc_helpers::g_dequant_tables.get_weight_tab(log_blk.m_weight_ise_range);
	const uint8_t* pWeight_dequant = weight_dequant_tab.m_ISE_to_val.data();

	for (uint32_t i = 0; i < total_weight_vals; i++)
	{
		assert(log_blk.m_weights[i] < weight_dequant_tab.m_ISE_to_val.size_u32());

		dequantized_weights[i] = pWeight_dequant[log_blk.m_weights[i]];
	}
		
	if ((log_blk.m_grid_width < block_width) || (log_blk.m_grid_height < block_height))
	{
		astc_helpers::upsample_weight_grid_xuastc_ldr(block_width, block_height, log_blk.m_grid_width, log_blk.m_grid_height, dequantized_weights, pDst_weights, nullptr, nullptr);
	}
	else
	{
		memcpy(pDst_weights, dequantized_weights, block_width * block_height);
	}
}

bool basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice(
	basis_tex_format src_format, bool use_astc_srgb_decode_profile,
	void* pDst_blocks,
	uint32_t src_num_blocks_x, uint32_t src_num_blocks_y,
	const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
	uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha,
	const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
	basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
{
	BASISU_NOTE_UNUSED(pState);
	BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);

#if BASISD_SUPPORT_XUASTC

	assert(g_transcoder_initialized);
	if (!g_transcoder_initialized)
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: Transcoder not globally initialized.\n");
		return false;
	}

	if (block_format_is_hdr(fmt))
	{
		assert(0);
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: Invalid fmt argument\n");
		return false;
	}

	//const uint32_t total_blocks = num_blocks_x * num_blocks_y;

	const uint32_t src_block_width = basis_tex_format_get_block_width(src_format), src_block_height = basis_tex_format_get_block_height(src_format);

	const uint32_t dst_fmt_block_width = get_block_width(fmt), dst_fmt_block_height = get_block_height(fmt);
	const bool dst_fmt_is_astc = block_format_is_astc(fmt);
	const bool dst_fmt_is_pvrtc1 = (fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA);

	if (dst_fmt_is_pvrtc1)
	{
		if (!basisu::is_pow2(orig_width) || !basisu::is_pow2(orig_height))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: PVRTC1 requires power of 2 texture dimensions\n");
			return false;
		}
	}

	const bool is_uncompressed_fmt = basis_block_format_is_uncompressed(fmt);
	if (!output_row_pitch_in_blocks_or_pixels)
	{
		if (is_uncompressed_fmt)
			output_row_pitch_in_blocks_or_pixels = orig_width;
		else
			output_row_pitch_in_blocks_or_pixels = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
	}

	if (is_uncompressed_fmt)
	{
		if (!output_rows_in_pixels)
			output_rows_in_pixels = orig_height;
	}

	const bool high_quality = (decode_flags & cDecodeFlagsHighQuality) != 0;
	const bool enable_fast_bc7_transcoding = (decode_flags & cDecodeFlagXUASTCLDRDisableFastBC7Transcoding) == 0;
	const bool from_alpha = has_alpha && (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
	
	// By default: block sizes >= 10x8 (80 texels) get automatically deblocked while transcoding, unless they've disabled using the cDecodeFlagsNoDeblockFiltering flag.
	const bool disable_deblocking = (decode_flags & cDecodeFlagsNoDeblockFiltering) != 0;
	const bool force_deblocking = (decode_flags & cDecodeFlagsForceDeblockFiltering) != 0;
	
	// Why automatically enable >= 80 texels? At 10x8 or larger, the blocks are so large most developers don't use these block sizes anyway (block artifacts are too noticeable), and they are unlikely to be normal maps.
	const bool deblock_filtering = !disable_deblocking && (force_deblocking || ((src_block_width * src_block_height >= BASISU_DEBLOCKING_BLOCK_SIZE_THRESHOLD)));
		
	const uint32_t bc7f_flags = high_quality ? bc7f::cPackBC7FlagDefaultPartiallyAnalytical : bc7f::cPackBC7FlagDefault;
	etc1f::pack_etc1_state etc1_pack_state;

	if (basis_tex_format_is_astc_ldr(src_format))
	{
		// Plain ASTC LDR 4x4-12x12 - note it could be ANY valid/standard ASTC written by any ASTC encoder, so we cannot trust this ASTC data. 
		// It must be fully validated.
		if (dst_fmt_is_astc)
		{
			assert(output_block_or_pixel_stride_in_bytes == sizeof(astc_helpers::astc_block));

			if ((dst_fmt_block_width != src_block_width) || (dst_fmt_block_height != src_block_height))
			{
				// ASTC block dimensions must match, i.e. we can't change the ASTC block size during transcoding.
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: fmt's ASTC block dimensions don't match the content's block dimensions\n");
				return false;
			}

			// No transcoding needed, it's ASTC in->ASTC out.
			memcpy(pDst_blocks, pImage_data, src_num_blocks_x * src_num_blocks_y * sizeof(astc_helpers::astc_block));
		}
		else if (((src_block_width == 4) && (src_block_height == 4)) && (!dst_fmt_is_pvrtc1) && (!deblock_filtering))
		{
			// Block dimensions aren't changing, no pvrtc1, no deblock filtering
			if ((dst_fmt_block_width != 4) || (dst_fmt_block_height != 4))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: fmt's ASTC block dimensions don't match the content's block dimensions\n");
				return false;
			}

			const astc_helpers::astc_block* pSrc_phys_blk = (const astc_helpers::astc_block*)pImage_data;

			astc_helpers::log_astc_block log_blk;

			for (uint32_t block_y = 0; block_y < src_num_blocks_y; block_y++)
			{
				uint8_t* pDst_block_u8 = (uint8_t*)pDst_blocks + block_y * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

				for (uint32_t block_x = 0; block_x < src_num_blocks_x; block_x++)
				{
					color32 block_pixels[4 * 4];

					bool unpack_status = astc_helpers::unpack_block(pSrc_phys_blk, log_blk, 4, 4);
					if (!unpack_status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::unpack_block() failed\n");
						return false;
					}
					
					// TODO: Specially handle solid block case
					bool decode_status = astc_helpers::decode_block(log_blk, block_pixels, 4, 4, use_astc_srgb_decode_profile ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8);
					if (!decode_status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block() failed\n");
						return false;
					}

					transcode_4x4_block(
						fmt,
						block_x, block_y,
						pDst_blocks, pDst_block_u8,
						block_pixels,
						output_block_or_pixel_stride_in_bytes, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels,
						channel0, channel1,
						high_quality, from_alpha,
						bc7f_flags,
						etc1_pack_state);

					pDst_block_u8 += output_block_or_pixel_stride_in_bytes;
					++pSrc_phys_blk;

				} // block_x

			} // block_y
		}
		else if ((!deblock_filtering) && (!dst_fmt_is_pvrtc1))
		{
			assert((dst_fmt_block_width == 4) && (dst_fmt_block_height == 4));

			// Compute how many source block rows we need to buffer so we have a multiple of 4 scanlines. The max # of scanlines is 20.
			uint32_t num_src_block_rows_to_buffer = 1;
			while ((num_src_block_rows_to_buffer * src_block_height) & 3)
				num_src_block_rows_to_buffer++;
			assert((num_src_block_rows_to_buffer >= 1) && (num_src_block_rows_to_buffer <= 4));

			// Compute how many 4x4 dest blocks fit into these many source rows.
			assert(((num_src_block_rows_to_buffer * src_block_height) & 3) == 0);
			//const uint32_t num_dst_block_rows_to_buffer = (num_src_block_rows_to_buffer * src_block_height) >> 2;

			const uint32_t dst_num_blocks_x = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
			const uint32_t dst_num_blocks_y = (orig_height + dst_fmt_block_height - 1) / dst_fmt_block_height;

			basisu::vector2D<color32> buffered_rows(src_num_blocks_x * src_block_width, num_src_block_rows_to_buffer * src_block_height);

			const astc_helpers::astc_block* pSrc_phys_blk = (const astc_helpers::astc_block*)pImage_data;

			astc_helpers::log_astc_block log_blk;

			for (uint32_t by = 0; by < src_num_blocks_y; by++)
			{
				const uint32_t buffered_src_block_row_y = (by % num_src_block_rows_to_buffer);
																
				for (uint32_t bx = 0; bx < src_num_blocks_x; bx++)
				{
					color32 block_pixels[astc_helpers::MAX_BLOCK_PIXELS];

					bool unpack_status = astc_helpers::unpack_block(pSrc_phys_blk, log_blk, src_block_width, src_block_height);
					if (!unpack_status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::unpack_block() failed\n");
						return false;
					}

					bool decode_status = astc_helpers::decode_block(log_blk, block_pixels, src_block_width, src_block_height, use_astc_srgb_decode_profile ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8);
					if (!decode_status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block() failed\n");
						return false;
					}

					color32* pSrc_pixels = block_pixels;
					color32* pDst_pixels = &buffered_rows(bx * src_block_width, buffered_src_block_row_y * src_block_height);

					for (uint32_t y = 0; y < src_block_height; y++)
					{
						memcpy(pDst_pixels, pSrc_pixels, src_block_width * sizeof(color32));

						pSrc_pixels += src_block_width;
						pDst_pixels += buffered_rows.get_width();
					} // y
										
					++pSrc_phys_blk;

				} // block_x

				const bool final_src_block_row = (by == (src_num_blocks_y - 1));
								
				if ((buffered_src_block_row_y != (num_src_block_rows_to_buffer - 1)) && (!final_src_block_row))
					continue;

				// src/destination image Y coordinate of the top of the buffered rows
				const uint32_t buffered_src_pixel_y = ((by / num_src_block_rows_to_buffer) * num_src_block_rows_to_buffer) * src_block_height;
				assert((buffered_src_pixel_y & 3) == 0);

				// The total # of valid src block rows we can read.
				const uint32_t num_buffered_src_block_rows = buffered_src_block_row_y + 1;

				assert((num_buffered_src_block_rows == num_src_block_rows_to_buffer) || (final_src_block_row));

				// The maximum number of valid buffer scanlines we can fetch from, taking into account the original texture's actual (unpadded) height.
				const uint32_t override_buffer_height = basisu::minimum(orig_height - buffered_src_pixel_y, num_buffered_src_block_rows * src_block_height);
				assert(override_buffer_height);

				// total_dst_block_rows_to_emit=really an upper bound for the final row of src ASTC blocks
				const uint32_t total_dst_block_rows_to_emit = (num_buffered_src_block_rows * src_block_height + 3) >> 2;

				for (uint32_t dst_ofs_by = 0; dst_ofs_by < total_dst_block_rows_to_emit; dst_ofs_by++)
				{
					const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dst_ofs_by;
					if (dst_by >= dst_num_blocks_y)
						break;

					for (uint32_t dst_bx = 0; dst_bx < dst_num_blocks_x; dst_bx++)
					{
						color32 block_pixels[4 * 4];

						// Extract the 4x4 block pixels from our buffered rows, taking into account the actual # of valid scanlines inside the buffer.
						buffered_rows.extract_block_clamped(block_pixels, dst_bx * 4, dst_ofs_by * 4, 4, 4, override_buffer_height);

						uint8_t* pDst_block_u8 = (uint8_t*)pDst_blocks + (dst_by * output_row_pitch_in_blocks_or_pixels + dst_bx) * output_block_or_pixel_stride_in_bytes;

						transcode_4x4_block(
							fmt,
							dst_bx, dst_by,
							pDst_blocks, pDst_block_u8,
							block_pixels,
							output_block_or_pixel_stride_in_bytes, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels,
							channel0, channel1,
							high_quality, from_alpha,
							bc7f_flags,
							etc1_pack_state);

					} // dst_bx

				} // dst_ofs_by

			} // block_y

		}
		else
		{
			// unpack entire 32bpp image into memory (needed for deblocking and PVRTC1)
			// TODO: Add more memory efficient non-deblocking code path
			basisu::vector2D<color32> temp_image;

			const uint32_t actual_width = src_block_width * src_num_blocks_x, actual_height = src_block_height * src_num_blocks_y;

			if (!temp_image.try_resize(actual_width, actual_height))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: out of memory\n");
				return false;
			}

			const astc_helpers::astc_block* pSrc_phys_blk = (const astc_helpers::astc_block*)pImage_data;

			astc_helpers::log_astc_block log_blk;
			color32 block_pixels[astc_helpers::MAX_BLOCK_PIXELS];

			for (uint32_t src_by = 0; src_by < src_num_blocks_y; src_by++)
			{
				const uint32_t img_y = src_by * src_block_height;

				for (uint32_t src_bx = 0; src_bx < src_num_blocks_x; src_bx++)
				{
					bool unpack_status = astc_helpers::unpack_block(pSrc_phys_blk, log_blk, src_block_width, src_block_height);
					if (!unpack_status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::unpack_block() failed\n");
						return false;
					}

					bool decode_status = astc_helpers::decode_block(log_blk, block_pixels, src_block_width, src_block_height, use_astc_srgb_decode_profile ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8);
					if (!decode_status)
					{
						BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block() failed\n");
						return false;
					}

					color32* pSrc_pixels = (color32*)block_pixels;
					color32* pDst_pixels = &temp_image(src_bx * src_block_width, img_y);

					for (uint32_t y = 0; y < src_block_height; y++)
					{
						memcpy(pDst_pixels, pSrc_pixels, src_block_width * sizeof(color32));

						pSrc_pixels += src_block_width;
						pDst_pixels += temp_image.get_width();
					} // y

					++pSrc_phys_blk;

				} // src_bx
			} // src_by

			if (deblock_filtering)
			{
				if (!xuastc_deblock_filter(
					src_block_width, src_block_height,
					temp_image, temp_image))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: out of memory\n");
					return false;
				}
			}

			const uint32_t dst_num_blocks_x = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
			const uint32_t dst_num_blocks_y = (orig_height + dst_fmt_block_height - 1) / dst_fmt_block_height;

			if (dst_fmt_is_pvrtc1)
			{
				assert((dst_fmt_block_width == 4) && (dst_fmt_block_height == 4));

				encode_pvrtc1(fmt, pDst_blocks, temp_image, dst_num_blocks_x, dst_num_blocks_y, from_alpha);
			}
			else
			{
				for (uint32_t dst_by = 0; dst_by < dst_num_blocks_y; dst_by++)
				{
					uint8_t* pDst_block_u8 = (uint8_t*)pDst_blocks + dst_by * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

					for (uint32_t dst_bx = 0; dst_bx < dst_num_blocks_x; dst_bx++)
					{
						temp_image.extract_block_clamped(block_pixels, dst_bx * 4, dst_by * 4, 4, 4);

						transcode_4x4_block(
							fmt,
							dst_bx, dst_by,
							pDst_blocks, pDst_block_u8,
							block_pixels,
							output_block_or_pixel_stride_in_bytes, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels,
							channel0, channel1,
							high_quality, from_alpha,
							bc7f_flags,
							etc1_pack_state);

						pDst_block_u8 += output_block_or_pixel_stride_in_bytes;

					} // dst_bx

				} // dst_by

			} // if (dst_fmt_is_pvrtc1)
		}
	}
	else
	{
		// Supercompressed XUASTC LDR 4x4-12x12
		// note use_astc_srgb_decode_profile can be ignored here, we'll use the decoded sRGB profile bit from the compressed stream.
				
		if (dst_fmt_is_astc)
		{
			// src and dst are ASTC - ideal case, just pack physical ASTC blocks to output buffer during transcoding.
			struct decode_state
			{
				uint32_t m_src_num_blocks_x;
				uint32_t m_src_num_blocks_y;
				uint32_t m_dst_format_block_width;
				uint32_t m_dst_format_block_height;

				void* m_pDst_blocks;
				uint32_t m_output_row_pitch_in_blocks_or_pixels;
				uint32_t m_output_block_or_pixel_stride_in_bytes;
			};

			decode_state dec_state;
			dec_state.m_src_num_blocks_x = src_num_blocks_x;
			dec_state.m_src_num_blocks_y = src_num_blocks_y;
			dec_state.m_dst_format_block_width = dst_fmt_block_width;
			dec_state.m_dst_format_block_height = dst_fmt_block_height;
			dec_state.m_pDst_blocks = pDst_blocks;
			dec_state.m_output_row_pitch_in_blocks_or_pixels = output_row_pitch_in_blocks_or_pixels;
			dec_state.m_output_block_or_pixel_stride_in_bytes = output_block_or_pixel_stride_in_bytes;

			auto init_func = [](uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t block_width, uint32_t block_height, bool srgb_decode_profile, float dct_q, bool has_alpha, void* pData)
			{
				BASISU_NOTE_UNUSED(srgb_decode_profile);
				BASISU_NOTE_UNUSED(dct_q);
				BASISU_NOTE_UNUSED(has_alpha);

				if (basisu::g_debug_printf)
					basisu::debug_printf("init_func: %u %u %u %u %u %f %u\n", num_blocks_x, num_blocks_y, block_width, block_height, srgb_decode_profile, dct_q, has_alpha);

				decode_state& state = *(decode_state*)pData;
				if ((block_width != state.m_dst_format_block_width) || (block_height != state.m_dst_format_block_height))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (1)\n");
					return false;
				}
				if ((num_blocks_x != state.m_src_num_blocks_x) || (num_blocks_y != state.m_src_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (2)\n");
					return false;
				}
				return true;
			};

			auto src_block_func = [](uint32_t bx, uint32_t by, const astc_helpers::log_astc_block& log_blk, void* pData)
			{
				decode_state& state = *(decode_state*)pData;
				assert((bx < state.m_src_num_blocks_x) && (by < state.m_src_num_blocks_y));

				astc_helpers::astc_block* pDst_astc_block = (astc_helpers::astc_block*)((uint8_t*)state.m_pDst_blocks + (by * state.m_output_row_pitch_in_blocks_or_pixels + bx) * state.m_output_block_or_pixel_stride_in_bytes);

				bool pack_status = astc_helpers::pack_astc_block(*pDst_astc_block, log_blk);
				if (!pack_status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::pack_astc_block() failed\n");
					return false;
				}

				return true;
			};
						
			xuastc_decoded_image decoded_image;

			const bool decomp_flag = decoded_image.decode(pImage_data, image_data_size, init_func, &dec_state, src_block_func, &dec_state);
			if (!decomp_flag)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_ldr_t::decompress_image() failed\n");
				return false;
			}
		}
		else if ((fmt == block_format::cBC7) && (src_block_width == 8) && (src_block_height == 6) &&
			(enable_fast_bc7_transcoding) && (!high_quality) && (!deblock_filtering))
		{
			// src is ASTC LDR 8x6, destination is BC7, no deblocking: buffer 2 rows of ASTC logical blocks, favor fast pure transcode to BC7 whenever possible.
			// transcodes 2 ASTC 8x6 blocks (a tile of 1x2 or 2*48=96 pixels) to 6 BC7 blocks (a tile of 2x3 of 6*16=96 pixels)
			// no BC7 block crosses more than 2 ASTC blocks making this easy if the source blocks are only solid or 1 subset

			const uint32_t num_src_block_rows_to_buffer = 2;

			assert(((num_src_block_rows_to_buffer* src_block_height) & 3) == 0);

			const uint32_t dst_num_blocks_x = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
			const uint32_t dst_num_blocks_y = (orig_height + dst_fmt_block_height - 1) / dst_fmt_block_height;

			basisu::vector2D<astc_helpers::log_astc_block> buffered_rows(src_num_blocks_x, num_src_block_rows_to_buffer);

			struct decode_state
			{
				uint32_t m_orig_height;

				uint32_t m_src_num_blocks_x;
				uint32_t m_src_num_blocks_y;
				uint32_t m_src_block_width;
				uint32_t m_src_block_height;

				uint32_t m_dst_num_blocks_x;
				uint32_t m_dst_num_blocks_y;

				void* m_pDst_blocks;
				uint32_t m_output_row_pitch_in_blocks_or_pixels;
				uint32_t m_output_block_or_pixel_stride_in_bytes;
				uint32_t m_output_rows_in_pixels;

				uint32_t m_num_src_block_rows_to_buffer;
				//uint32_t m_num_dst_block_rows_to_buffer;

				basisu::vector2D<astc_helpers::log_astc_block>* m_pBuffered_rows;

				bool m_used_srgb_astc_decode_mode;
				bool m_has_alpha;

				uint32_t m_total_src_blocks_unpacked;
				uint32_t m_total_src_blocks_partial_unpacked;
				uint32_t m_total_blocks_transcoded;
				uint32_t m_total_blocks_encoded;

				block_format m_fmt;
				int m_channel0, m_channel1;
				bool m_high_quality;
				bool m_from_alpha;
				uint32_t m_bc7f_flags;
				etc1f::pack_etc1_state* m_pEtc1_pack_state;
			};

			decode_state dec_state;
			dec_state.m_orig_height = orig_height;
			dec_state.m_src_num_blocks_x = src_num_blocks_x;
			dec_state.m_src_num_blocks_y = src_num_blocks_y;
			dec_state.m_src_block_width = src_block_width;
			dec_state.m_src_block_height = src_block_height;
			dec_state.m_dst_num_blocks_x = dst_num_blocks_x;
			dec_state.m_dst_num_blocks_y = dst_num_blocks_y;
			dec_state.m_pDst_blocks = pDst_blocks;
			dec_state.m_output_row_pitch_in_blocks_or_pixels = output_row_pitch_in_blocks_or_pixels;
			dec_state.m_output_block_or_pixel_stride_in_bytes = output_block_or_pixel_stride_in_bytes;
			dec_state.m_output_rows_in_pixels = output_rows_in_pixels;

			dec_state.m_num_src_block_rows_to_buffer = num_src_block_rows_to_buffer;
			//dec_state.m_num_dst_block_rows_to_buffer = num_dst_block_rows_to_buffer;

			dec_state.m_pBuffered_rows = &buffered_rows;
			dec_state.m_used_srgb_astc_decode_mode = false; // will be set by init from the compressed stream's header
			dec_state.m_has_alpha = true; // will be set by init from the compressed stream's header

			dec_state.m_total_src_blocks_unpacked = 0;
			dec_state.m_total_src_blocks_partial_unpacked = 0;
			dec_state.m_total_blocks_transcoded = 0;
			dec_state.m_total_blocks_encoded = 0;

			dec_state.m_fmt = fmt;
			dec_state.m_channel0 = channel0;
			dec_state.m_channel1 = channel1;
			dec_state.m_high_quality = high_quality;
			dec_state.m_from_alpha = from_alpha;
			dec_state.m_bc7f_flags = bc7f_flags;
			dec_state.m_pEtc1_pack_state = &etc1_pack_state;

			auto init_func = [](uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t block_width, uint32_t block_height, bool srgb_decode_profile, float dct_q, bool has_alpha, void* pData)
			{
				BASISU_NOTE_UNUSED(srgb_decode_profile);
				BASISU_NOTE_UNUSED(dct_q);
				
				if (basisu::g_debug_printf)
					basisu::debug_printf("init_func: %u %u %u %u %u %f %u\n", num_blocks_x, num_blocks_y, block_width, block_height, srgb_decode_profile, dct_q, has_alpha);

				decode_state& state = *(decode_state*)pData;
				if ((block_width != state.m_src_block_width) || (block_height != state.m_src_block_height))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (3)\n");
					return false;
				}
				if ((num_blocks_x != state.m_src_num_blocks_x) || (num_blocks_y != state.m_src_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (4)\n");
					return false;
				}

				state.m_used_srgb_astc_decode_mode = srgb_decode_profile;
				state.m_has_alpha = has_alpha;

				return true;
			};

			auto src_block_func = [](uint32_t bx, uint32_t by, const astc_helpers::log_astc_block& log_blk, void* pData)
			{
				decode_state& state = *(decode_state*)pData;
				assert((bx < state.m_src_num_blocks_x) && (by < state.m_src_num_blocks_y));
				assert(state.m_num_src_block_rows_to_buffer == 2); // hardcoded for 6x6
				const astc_helpers::decode_mode astc_dec_mode = state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8;

				const uint32_t buffered_src_block_row_y = (by & 1);

				memcpy(&(*state.m_pBuffered_rows)(bx, buffered_src_block_row_y), &log_blk, sizeof(log_blk));

				// Last block on this src row? If not, exit.
				if (bx != (state.m_src_num_blocks_x - 1))
					return true;

				// We've written the final src block for this ASTC src row. 
				// See if we have enough source rows to create full 4x4 destination blocks.
				const bool final_src_block_row = (by == (state.m_src_num_blocks_y - 1));
								
				if ((buffered_src_block_row_y != (state.m_num_src_block_rows_to_buffer - 1)) && (!final_src_block_row))
					return true;
				
				// We have a full 1-2 rows of ASTC 6x6 blocks to process to BC7.

				// src/destination image Y coordinate of the top of the buffered rows
				const uint32_t buffered_src_pixel_y = ((by / state.m_num_src_block_rows_to_buffer) * state.m_num_src_block_rows_to_buffer) * state.m_src_block_height;
				assert((buffered_src_pixel_y & 3) == 0);

				// The total # of valid src block rows we can read.
				const uint32_t num_buffered_src_block_rows = buffered_src_block_row_y + 1;

				assert((num_buffered_src_block_rows == state.m_num_src_block_rows_to_buffer) || (final_src_block_row));

#if defined(DEBUG) || defined(_DEBUG)
				// The maximum number of valid buffer pixel scanlines we can fetch from, taking into account the original texture's actual (unpadded) height.
				const uint32_t override_buffer_height = basisu::minimum(state.m_orig_height - buffered_src_pixel_y, num_buffered_src_block_rows * state.m_src_block_height);
				assert(override_buffer_height);
#endif

				// total_dst_block_rows_to_emit=really an upper bound for the final row of src ASTC blocks
				const uint32_t total_dst_block_rows_to_emit = (num_buffered_src_block_rows * state.m_src_block_height + 3) >> 2;
								
				color_rgba unpacked_src_blocks[2][8 * 6]; // [astc_by][pixel]
				uint8_t upsampled_src_weights[2][8 * 6]; // [astc_by][pixel]
				color_rgba temp_pixels_16[16];
			
				// Process each source ASTC 8x6 block group, 1x2 ASTC blocks at a time
				for (uint32_t src_bx = 0; src_bx < state.m_src_num_blocks_x; src_bx++)
				{
					bool has_unpacked_src_blocks[2] = { }; // [astc_by]

					// Grab pointers to the 1x2 src ASTC blocks we'll be transcoding
					const astc_helpers::log_astc_block* pSrc_log_blocks[2]; // [astc_by]

					pSrc_log_blocks[0] = &state.m_pBuffered_rows->at(src_bx, 0);
					pSrc_log_blocks[1] = &state.m_pBuffered_rows->at(src_bx, basisu::minimum<uint32_t>(1, num_buffered_src_block_rows - 1));

					// From here we can always assume 2x2 src ASTC 6x6 blocks, with ASTC block pointers duplicated at the borders if needed.

					const astc_helpers::log_astc_block* pU = pSrc_log_blocks[0];
					const astc_helpers::log_astc_block* pL = pSrc_log_blocks[1];

					if (blocks_same_solid_colors(*pU, *pL, 0))
					{
						// Easy and fast case: All 2 ASTC blocks are solid and the same color, so all 6 BC7 blocks are solid too and the same color.
						color_rgba sc;
						sc.r = (uint8_t)(pU->m_solid_color[0] >> 8);
						sc.g = (uint8_t)(pU->m_solid_color[1] >> 8);
						sc.b = (uint8_t)(pU->m_solid_color[2] >> 8);
						sc.a = (uint8_t)(pU->m_solid_color[3] >> 8);

						bc7_block temp_blk;
						bc7f::pack_mode5_solid((uint8_t*)&temp_blk, sc);

						for (uint32_t dy = 0; dy < total_dst_block_rows_to_emit; dy++) // up to 3 dst block rows
						{
							const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dy;
							if (dst_by >= state.m_dst_num_blocks_y)
								break;

							for (uint32_t dx = 0; dx < 2; dx++)
							{
								const uint32_t dst_bx = (src_bx << 1) + dx;
								if (dst_bx >= state.m_dst_num_blocks_x)
									break;

								uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;

								memcpy(pDst_block_u8, &temp_blk, sizeof(bc7_block));
							} // dx
						} // dy

						continue;
					}

					uint32_t num_hard_src_blocks = 0;

					for (uint32_t y = 0; y < 2; y++)
						num_hard_src_blocks += (pSrc_log_blocks[y]->m_dual_plane || (pSrc_log_blocks[y]->m_num_partitions > 1));

					if (num_hard_src_blocks == 2)
					{
						// All src blocks hard, no easy optimizations, so unpack and encode pixels analytically
						for (uint32_t y = 0; y < 2; y++)
						{
							bool status = astc_helpers::decode_block_xuastc_ldr(*pSrc_log_blocks[y], &unpacked_src_blocks[y][0], 8, 6, astc_dec_mode);
							if (!status)
							{
								return false;
							}
							state.m_total_src_blocks_unpacked++;
						}

						for (uint32_t dy = 0; dy < total_dst_block_rows_to_emit; dy++) // up to 3 dst block rows
						{
							const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dy;
							if (dst_by >= state.m_dst_num_blocks_y)
								break;

							for (uint32_t dx = 0; dx < 2; dx++)
							{
								const uint32_t dst_bx = (src_bx << 1) + dx;
								if (dst_bx >= state.m_dst_num_blocks_x)
									break;

								for (uint32_t y = 0; y < 4; y++)
								{
									const uint32_t sy = dy * 4 + y;

									const uint32_t sy_div6 = sy / 6;
									const uint32_t src_row_ofs = (sy % 6) * 8;

									for (uint32_t x = 0; x < 4; x++)
									{
										const uint32_t sx = dx * 4 + x;
										temp_pixels_16[x + y * 4] = unpacked_src_blocks[sy_div6][sx + src_row_ofs];
									} // x
								} // y

								uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;

								if (state.m_has_alpha)
									bc7f::fast_pack_bc7_auto_rgba(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);
								else
									bc7f::fast_pack_bc7_auto_rgb(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);

								state.m_total_blocks_encoded++;
							} // dx
						} // dy

						continue;
					}

					// One or both of the 2 source blocks is solid or 1 subset.

					// For simplicity: First unpack the first plane weight grids (unless solid)
					for (uint32_t y = 0; y < 2; y++)
						astc_upsample_grid_weights(*pSrc_log_blocks[y], &upsampled_src_weights[y][0], 8, 6);

					const uint32_t ENDPOINT_TOL = 0;

					// Process each of the up to 6 destination BC7 blocks.
					for (uint32_t dy = 0; dy < total_dst_block_rows_to_emit; dy++) // up to 3 dst block rows
					{
						const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dy;
						if (dst_by >= state.m_dst_num_blocks_y)
							break;

						for (uint32_t dx = 0; dx < 2; dx++)
						{
							const uint32_t dst_bx = (src_bx << 1) + dx;
							if (dst_bx >= state.m_dst_num_blocks_x)
								break;

							uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;

							// BC7 block only overlaps 1 or 2 ASTC blocks.
							const int top_dy = dy * 4;
							const int bot_dy = top_dy + 3;

							const int top_by = top_dy / 6;
							const int bot_by = bot_dy / 6;

							const astc_helpers::log_astc_block* pB0 = pSrc_log_blocks[top_by];
							const astc_helpers::log_astc_block* pB1 = pSrc_log_blocks[bot_by];

							const bool single_src_block = (top_by == bot_by);

							bool full_encode_flag = false;

							if (pB0->m_dual_plane || pB1->m_dual_plane ||
								(pB0->m_num_partitions > 1) || (pB1->m_num_partitions > 1))
							{
								// Either block is complex, fall back to reencoding
								full_encode_flag = true;
							}
							else if (single_src_block)
							{
								assert(pB0 == pB1);

								// BC7 block is at a corner, and only overlaps a single ASTC block - output solid or single subset BC7
								if (pB0->m_solid_color_flag_ldr)
								{
									color_rgba sc;
									sc.r = (uint8_t)(pB0->m_solid_color[0] >> 8);
									sc.g = (uint8_t)(pB0->m_solid_color[1] >> 8);
									sc.b = (uint8_t)(pB0->m_solid_color[2] >> 8);
									sc.a = (uint8_t)(pB0->m_solid_color[3] >> 8);

									bc7f::pack_mode5_solid(pDst_block_u8, sc);
								}
								else
								{
									// Output mode 6 BC7
									bc7f::pack_from_astc_single_subset(pDst_block_u8, *pB0, &upsampled_src_weights[top_by][0], dx * 4, (dy * 4) % 6, 8, 6);
								}

								state.m_total_blocks_transcoded++;
							}
							// must be overlapping 2 ASTC blocks, can't be both solid as we've already checked
							else if (blocks_same_single_subset_endpoints(*pB0, *pB1, ENDPOINT_TOL))
							{
								// BC7 blocks overlaps 2 single subset ASTC blocks, both have the same or very similar endpoints, output mode 6 BC7
								bc7f::pack_from_astc_to_single_subset_same_endpoints(
									pDst_block_u8,
									*pB0, &upsampled_src_weights[top_by][0],
									*pB1, &upsampled_src_weights[bot_by][0],
									dx, dy, 
									8, 6);

								state.m_total_blocks_transcoded++;
							}
							else if (!block_has_alpha(*pB0) && !block_has_alpha(*pB1))
							{
								bool fallback_encode_flag = false;

								// BC7 block overlaps 2 ASTC blocks with different endpoints (or solid colors) - output 2 subset mode 1 BC7
								if (!bc7f::pack_from_astc_8x6_to_two_subsets_different_endpoints_hq(
									pDst_block_u8,
									*pB0, &upsampled_src_weights[top_by][0],
									*pB1, &upsampled_src_weights[bot_by][0],
									dx, dy, state.m_used_srgb_astc_decode_mode, fallback_encode_flag))
								{
									full_encode_flag = true;
								}
								else
								{
									if (fallback_encode_flag)
										state.m_total_src_blocks_partial_unpacked++;
									else
										state.m_total_blocks_transcoded++;
								}
							}
							else
							{
								full_encode_flag = true;
							}

							if (full_encode_flag)
							{
								// one or both ASTC blocks are just too complex, unpack and reencode
								if (!has_unpacked_src_blocks[top_by])
								{
									bool status = astc_helpers::decode_block_xuastc_ldr(*pB0, &unpacked_src_blocks[top_by][0], 8, 6, astc_dec_mode, &upsampled_src_weights[top_by][0]);
									if (!status)
									{
										return false;
									}
									state.m_total_src_blocks_unpacked++;
									has_unpacked_src_blocks[top_by] = true;
								}

								if (!has_unpacked_src_blocks[bot_by])
								{
									bool status = astc_helpers::decode_block_xuastc_ldr(*pB1, &unpacked_src_blocks[bot_by][0], 8, 6, astc_dec_mode, &upsampled_src_weights[bot_by][0]);
									if (!status)
									{
										return false;
									}
									state.m_total_src_blocks_unpacked++;
									has_unpacked_src_blocks[bot_by] = true;
								}

								for (uint32_t y = 0; y < 4; y++)
								{
									const uint32_t sy = dy * 4 + y;
									
									assert(has_unpacked_src_blocks[sy / 6]);

									const uint32_t sy_div6 = sy / 6;
									const uint32_t src_row_ofs = (sy % 6) * 8;
																		
									for (uint32_t x = 0; x < 4; x++)
									{
										const uint32_t sx = dx * 4 + x;

										temp_pixels_16[x + y * 4] = unpacked_src_blocks[sy_div6][sx + src_row_ofs];
									} // x
								} // y

								if (state.m_has_alpha)
									bc7f::fast_pack_bc7_auto_rgba(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);
								else
									bc7f::fast_pack_bc7_auto_rgb(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);

								state.m_total_blocks_encoded++;
							}

						} // dx
					} // dy

				} // src_bx

				return true;
			};

			xuastc_decoded_image decoded_image;

			const bool decomp_flag = decoded_image.decode(pImage_data, image_data_size, init_func, &dec_state, src_block_func, &dec_state);
			if (!decomp_flag)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_ldr_t::decompress_image() failed\n");
				return false;
			}

			if (basisu::g_debug_printf)
			{
				basisu::fmt_debug_printf("Total src blocks: {}, Total src blocks fully unpacked to pixels: {}\n",
					dec_state.m_src_num_blocks_x * dec_state.m_src_num_blocks_y,
					dec_state.m_total_src_blocks_unpacked);

				basisu::fmt_debug_printf("Total dst blocks: {}, Total blocks transcoded: {}, fully encoded: {}, total partially unpacked/fast mode 6 encoded: {}\n", 
					dec_state.m_dst_num_blocks_x * dec_state.m_dst_num_blocks_y,
					dec_state.m_total_blocks_transcoded, dec_state.m_total_blocks_encoded,
					dec_state.m_total_src_blocks_partial_unpacked);
			}

			// end of 8x6->4x4 transcoder
		}
		else if ((fmt == block_format::cBC7) && (src_block_width == 6) && (src_block_height == 6) &&
			(enable_fast_bc7_transcoding) && (!high_quality) && (!deblock_filtering))
		{
			// src is ASTC LDR 6x6, destination is BC7, no deblocking: buffer 2 rows of ASTC logical blocks, favor fast pure transcode to BC7 whenever possible.
			// This path is maddenningly tricky, but the speed gains in certain use cases are worth it.

			const uint32_t num_src_block_rows_to_buffer = 2;
			
			assert(((num_src_block_rows_to_buffer * src_block_height) & 3) == 0);

			const uint32_t dst_num_blocks_x = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
			const uint32_t dst_num_blocks_y = (orig_height + dst_fmt_block_height - 1) / dst_fmt_block_height;

			basisu::vector2D<astc_helpers::log_astc_block> buffered_rows(src_num_blocks_x, num_src_block_rows_to_buffer);

			struct decode_state
			{
				uint32_t m_orig_height;

				uint32_t m_src_num_blocks_x;
				uint32_t m_src_num_blocks_y;
				uint32_t m_src_block_width;
				uint32_t m_src_block_height;

				uint32_t m_dst_num_blocks_x;
				uint32_t m_dst_num_blocks_y;

				void* m_pDst_blocks;
				uint32_t m_output_row_pitch_in_blocks_or_pixels;
				uint32_t m_output_block_or_pixel_stride_in_bytes;
				uint32_t m_output_rows_in_pixels;

				uint32_t m_num_src_block_rows_to_buffer;
				//uint32_t m_num_dst_block_rows_to_buffer;

				basisu::vector2D<astc_helpers::log_astc_block> *m_pBuffered_rows;

				bool m_used_srgb_astc_decode_mode;
				bool m_has_alpha;

				uint32_t m_total_src_blocks_unpacked;
				uint32_t m_total_src_blocks_partial_unpacked;
				uint32_t m_total_blocks_transcoded;
				uint32_t m_total_blocks_encoded;

				block_format m_fmt;
				int m_channel0, m_channel1;
				bool m_high_quality;
				bool m_from_alpha;
				uint32_t m_bc7f_flags;
				etc1f::pack_etc1_state* m_pEtc1_pack_state;
			};

			decode_state dec_state;
			dec_state.m_orig_height = orig_height;
			dec_state.m_src_num_blocks_x = src_num_blocks_x;
			dec_state.m_src_num_blocks_y = src_num_blocks_y;
			dec_state.m_src_block_width = src_block_width;
			dec_state.m_src_block_height = src_block_height;
			dec_state.m_dst_num_blocks_x = dst_num_blocks_x;
			dec_state.m_dst_num_blocks_y = dst_num_blocks_y;
			dec_state.m_pDst_blocks = pDst_blocks;
			dec_state.m_output_row_pitch_in_blocks_or_pixels = output_row_pitch_in_blocks_or_pixels;
			dec_state.m_output_block_or_pixel_stride_in_bytes = output_block_or_pixel_stride_in_bytes;
			dec_state.m_output_rows_in_pixels = output_rows_in_pixels;

			dec_state.m_num_src_block_rows_to_buffer = num_src_block_rows_to_buffer;
			//dec_state.m_num_dst_block_rows_to_buffer = num_dst_block_rows_to_buffer;

			dec_state.m_pBuffered_rows = &buffered_rows;
			dec_state.m_used_srgb_astc_decode_mode = false; // will be set by init from the compressed stream's header
			dec_state.m_has_alpha = true; // will be set by init from the compressed stream's header

			dec_state.m_total_src_blocks_unpacked = 0;
			dec_state.m_total_src_blocks_partial_unpacked = 0;
			dec_state.m_total_blocks_transcoded = 0;
			dec_state.m_total_blocks_encoded = 0;

			dec_state.m_fmt = fmt;
			dec_state.m_channel0 = channel0;
			dec_state.m_channel1 = channel1;
			dec_state.m_high_quality = high_quality;
			dec_state.m_from_alpha = from_alpha;
			dec_state.m_bc7f_flags = bc7f_flags;
			dec_state.m_pEtc1_pack_state = &etc1_pack_state;

			auto init_func = [](uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t block_width, uint32_t block_height, bool srgb_decode_profile, float dct_q, bool has_alpha, void* pData)
			{
				BASISU_NOTE_UNUSED(srgb_decode_profile);
				BASISU_NOTE_UNUSED(dct_q);
				
				if (basisu::g_debug_printf)
					basisu::debug_printf("init_func: %u %u %u %u %u %f %u\n", num_blocks_x, num_blocks_y, block_width, block_height, srgb_decode_profile, dct_q, has_alpha);

				decode_state& state = *(decode_state*)pData;
				if ((block_width != state.m_src_block_width) || (block_height != state.m_src_block_height))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (3)\n");
					return false;
				}
				if ((num_blocks_x != state.m_src_num_blocks_x) || (num_blocks_y != state.m_src_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (4)\n");
					return false;
				}

				state.m_used_srgb_astc_decode_mode = srgb_decode_profile;
				state.m_has_alpha = has_alpha;

				return true;
			};

			auto src_block_func = [](uint32_t bx, uint32_t by, const astc_helpers::log_astc_block& log_blk, void* pData)
			{
				decode_state& state = *(decode_state*)pData;
				assert((bx < state.m_src_num_blocks_x) && (by < state.m_src_num_blocks_y));
				assert(state.m_num_src_block_rows_to_buffer == 2); // hardcoded for 6x6
				const astc_helpers::decode_mode astc_dec_mode = state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8;

				const uint32_t buffered_src_block_row_y = (by & 1);

				memcpy(&(*state.m_pBuffered_rows)(bx, buffered_src_block_row_y), &log_blk, sizeof(log_blk));

				// Last block on this src row? If not, exit.
				if (bx != (state.m_src_num_blocks_x - 1))
					return true;

				// We've written the final src block for this ASTC src row. 
				// See if we have enough source rows to create full 4x4 destination blocks.
				const bool final_src_block_row = (by == (state.m_src_num_blocks_y - 1));
								
				if ((buffered_src_block_row_y != (state.m_num_src_block_rows_to_buffer - 1)) && (!final_src_block_row))
					return true;
				
				// We have a full 1-2 rows of ASTC 6x6 blocks to process to BC7.

				// src/destination image Y coordinate of the top of the buffered rows
				const uint32_t buffered_src_pixel_y = ((by / state.m_num_src_block_rows_to_buffer) * state.m_num_src_block_rows_to_buffer) * state.m_src_block_height;
				assert((buffered_src_pixel_y & 3) == 0);

				// The total # of valid src block rows we can read.
				const uint32_t num_buffered_src_block_rows = buffered_src_block_row_y + 1;

				assert((num_buffered_src_block_rows == state.m_num_src_block_rows_to_buffer) || (final_src_block_row));

#if defined(DEBUG) || defined(_DEBUG)
				// The maximum number of valid buffer pixel scanlines we can fetch from, taking into account the original texture's actual (unpadded) height.
				const uint32_t override_buffer_height = basisu::minimum(state.m_orig_height - buffered_src_pixel_y, num_buffered_src_block_rows * state.m_src_block_height);
				assert(override_buffer_height);
#endif

				// total_dst_block_rows_to_emit=really an upper bound for the final row of src ASTC blocks
				const uint32_t total_dst_block_rows_to_emit = (num_buffered_src_block_rows * state.m_src_block_height + 3) >> 2;
								
				color_rgba unpacked_src_blocks[2][2][6 * 6]; // [x][y][pixel]
				uint8_t upsampled_src_weights[2][2][6 * 6]; // [x][y][pixel]
				color_rgba temp_pixels_16[16];
				
				// Process each source ASTC 6x6 block group, 2x2 ASTC blocks at a time (12x12 pixels, or 3x3 BC7 blocks)
				for (uint32_t src_bx = 0; src_bx < state.m_src_num_blocks_x; src_bx += 2)
				{
					bool has_unpacked_src_blocks[2][2] = { }; // [x][y]

					// Grab pointers to the 2x2 src ASTC blocks we'll be transcoding
					const astc_helpers::log_astc_block *pSrc_log_blocks[2][2]; // [x][y]

					pSrc_log_blocks[0][0] = &state.m_pBuffered_rows->at(src_bx, 0);
					pSrc_log_blocks[1][0] = &state.m_pBuffered_rows->at(basisu::minimum<uint32_t>(src_bx + 1, state.m_src_num_blocks_x - 1), 0);

					pSrc_log_blocks[0][1] = &state.m_pBuffered_rows->at(src_bx, basisu::minimum<uint32_t>(1, num_buffered_src_block_rows - 1));
					
					pSrc_log_blocks[1][1] = &state.m_pBuffered_rows->at(
						basisu::minimum<uint32_t>(src_bx + 1, state.m_src_num_blocks_x - 1), 
						basisu::minimum<uint32_t>(1, num_buffered_src_block_rows - 1));

					// From here we can always assume 2x2 src ASTC 6x6 blocks, with ASTC block pointers duplicated at the borders if needed.

					const astc_helpers::log_astc_block* pUL = pSrc_log_blocks[0][0];

					// First see if all the astc blocks are the same solid color. Likely a common case on some images.
					bool all_solid = true;
					for (uint32_t y = 0; (y < 2) && all_solid; y++)
					{
						for (uint32_t x = 0; x < 2; x++)
						{
							if (!pSrc_log_blocks[x][y]->m_solid_color_flag_ldr)
							{
								all_solid = false;
								break;
							}

							if ((pSrc_log_blocks[x][y]->m_solid_color[0] != pUL->m_solid_color[0]) || (pSrc_log_blocks[x][y]->m_solid_color[1] != pUL->m_solid_color[1]) ||
								(pSrc_log_blocks[x][y]->m_solid_color[2] != pUL->m_solid_color[2]) || (pSrc_log_blocks[x][y]->m_solid_color[3] != pUL->m_solid_color[3]))
							{
								all_solid = false;
								break;
							}
						}
					}
					
					if (all_solid)
					{
						// Easy and fast case: All 4 ASTC blocks are solid and the same color, so all 9 BC7 blocks are solid too and the same color.
						color_rgba sc;
						sc.r = (uint8_t)(pUL->m_solid_color[0] >> 8);
						sc.g = (uint8_t)(pUL->m_solid_color[1] >> 8);
						sc.b = (uint8_t)(pUL->m_solid_color[2] >> 8);
						sc.a = (uint8_t)(pUL->m_solid_color[3] >> 8);

						bc7_block temp_blk;
						bc7f::pack_mode5_solid((uint8_t *)&temp_blk, sc);

						for (uint32_t dy = 0; dy < total_dst_block_rows_to_emit; dy++) // up to 3 dst block rows
						{
							const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dy;
							if (dst_by >= state.m_dst_num_blocks_y)
								break;

							for (uint32_t dx = 0; dx < 3; dx++)
							{
								const uint32_t dst_bx = ((src_bx * 6) >> 2) + dx;
								if (dst_bx >= state.m_dst_num_blocks_x)
									break;

								uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;

								memcpy(pDst_block_u8, &temp_blk, sizeof(bc7_block));
							}
						}

						continue;
					}

					uint32_t num_hard_src_blocks = 0;
					
					for (uint32_t y = 0; y < 2; y++)
						for (uint32_t x = 0; x < 2; x++)
							num_hard_src_blocks += (pSrc_log_blocks[x][y]->m_dual_plane || (pSrc_log_blocks[x][y]->m_num_partitions > 1));

					if (num_hard_src_blocks == 4)
					{
						// All src blocks hard, no easy optimizations, so unpack and encode pixels analytically
						for (uint32_t y = 0; y < 2; y++)
						{
							for (uint32_t x = 0; x < 2; x++)
							{
								bool status = astc_helpers::decode_block_xuastc_ldr(*pSrc_log_blocks[x][y], &unpacked_src_blocks[x][y][0], 6, 6, astc_dec_mode);
								if (!status)
								{
									return false;
								}
								state.m_total_src_blocks_unpacked++;
							}
						}

						for (uint32_t dy = 0; dy < total_dst_block_rows_to_emit; dy++) // up to 3 dst block rows
						{
							const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dy;
							if (dst_by >= state.m_dst_num_blocks_y)
								break;

							for (uint32_t dx = 0; dx < 3; dx++)
							{
								const uint32_t dst_bx = ((src_bx * 6) >> 2) + dx;
								if (dst_bx >= state.m_dst_num_blocks_x)
									break;
									
								// TODO: Optimize
								for (uint32_t y = 0; y < 4; y++)
								{
									const uint32_t sy = dy * 4 + y;
									for (uint32_t x = 0; x < 4; x++)
									{
										const uint32_t sx = dx * 4 + x;
										temp_pixels_16[x + y * 4] = unpacked_src_blocks[sx / 6][sy / 6][(sx % 6) + (sy % 6) * 6];
									} // x
								} // y
								
								uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;

								if (state.m_has_alpha)
									bc7f::fast_pack_bc7_auto_rgba(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);
								else
									bc7f::fast_pack_bc7_auto_rgb(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);

								state.m_total_blocks_encoded++;
							} // dx
						} // dy

						continue;
					}

					// One or more of the 4 source blocks is solid or 1 subset.

					// For simplicity: First unpack the first plane weight grids (unless solid)
					for (uint32_t y = 0; y < 2; y++)
						for (uint32_t x = 0; x < 2; x++)
							astc_upsample_grid_weights(*pSrc_log_blocks[x][y], &upsampled_src_weights[x][y][0], 6, 6);
					
					//const uint32_t ENDPOINT_TOL = 3;
					const uint32_t ENDPOINT_TOL = 1;

					// Process each of the 9 destination BC7 blocks.
					for (uint32_t dy = 0; dy < total_dst_block_rows_to_emit; dy++) // up to 3 dst block rows
					{
						const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dy;
						if (dst_by >= state.m_dst_num_blocks_y)
							break;

						for (uint32_t dx = 0; dx < 3; dx++)
						{
							// skip the central block, which we'll processed last
							if ((dx == 1) && (dy == 1))
								continue;

							const uint32_t dst_bx = ((src_bx * 6) >> 2) + dx;
							if (dst_bx >= state.m_dst_num_blocks_x)
								break;

							uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;
																																			
							// We're NOT at the center BC7 dst block.
							// BC7 block only overlaps 1 or 2 ASTC blocks.
							const int top_dx = dx * 4, top_dy = dy * 4;
							const int bot_dx = top_dx + 3, bot_dy = top_dy + 3;

							const int top_bx = top_dx / 6, top_by = top_dy / 6;
							const int bot_bx = bot_dx / 6, bot_by = bot_dy / 6;

							const astc_helpers::log_astc_block* pB0 = pSrc_log_blocks[top_bx][top_by];
							const astc_helpers::log_astc_block* pB1 = pSrc_log_blocks[bot_bx][bot_by];

							// Note: because of row/col duplication at the edges of images, pB0 could equal pB1 even though we're not at a BC7 corner block.

							const bool single_src_block = (top_bx == bot_bx) && (top_by == bot_by);

							bool full_encode_flag = false;

							if (pB0->m_dual_plane || pB1->m_dual_plane ||
								(pB0->m_num_partitions > 1) || (pB1->m_num_partitions > 1))
							{
								// Either block is complex, fall back to reencoding
								full_encode_flag = true;
							}
							else if (single_src_block)
							{
								assert(pB0 == pB1);

								// BC7 block is at a corner, and only overlaps a single ASTC block - output solid or single subset BC7
								if (pB0->m_solid_color_flag_ldr)
								{
									color_rgba sc;
									sc.r = (uint8_t)(pB0->m_solid_color[0] >> 8);
									sc.g = (uint8_t)(pB0->m_solid_color[1] >> 8);
									sc.b = (uint8_t)(pB0->m_solid_color[2] >> 8);
									sc.a = (uint8_t)(pB0->m_solid_color[3] >> 8);

									bc7f::pack_mode5_solid(pDst_block_u8, sc);
								}
								else
								{
									// Output mode 6 BC7
									bc7f::pack_from_astc_single_subset(pDst_block_u8, *pB0, &upsampled_src_weights[top_bx][top_by][0], (dx * 4) % 6, (dy * 4) % 6, 6, 6);
								}

								state.m_total_blocks_transcoded++;
							}
							// below here BC7 block always overlaps 2 ASTC 6x6 blocks (1 block case just ruled out)
							else if (blocks_same_solid_colors(*pB0, *pB1, 0))
							{
								// BC7 block overlaps 2 ASTC blocks, both solid colors, both same colors

								color_rgba sc;
								sc.r = (uint8_t)(pB0->m_solid_color[0] >> 8);
								sc.g = (uint8_t)(pB0->m_solid_color[1] >> 8);
								sc.b = (uint8_t)(pB0->m_solid_color[2] >> 8);
								sc.a = (uint8_t)(pB0->m_solid_color[3] >> 8);
								bc7f::pack_mode5_solid(pDst_block_u8, sc);

								state.m_total_blocks_transcoded++;
							}
							else if (blocks_same_single_subset_endpoints(*pB0, *pB1, ENDPOINT_TOL))
							{
								// BC7 blocks overlaps 2 single subset ASTC blocks, both have the same or very similar endpoints, output mode 6 BC7
								bc7f::pack_from_astc_to_single_subset_same_endpoints(
									pDst_block_u8,
									*pB0, &upsampled_src_weights[top_bx][top_by][0],
									*pB1, &upsampled_src_weights[bot_bx][bot_by][0],
									dx, dy, 
									6, 6);

								state.m_total_blocks_transcoded++;
							}
							else if (!block_has_alpha(*pB0) && !block_has_alpha(*pB1))
							{
								// BC7 block overlaps 2 ASTC blocks with different endpoints (or solid colors) - output 2 subset mode 1 BC7
								if (!bc7f::pack_from_astc_6x6_to_two_subsets_different_endpoints(
									pDst_block_u8,
									*pB0, &upsampled_src_weights[top_bx][top_by][0],
									*pB1, &upsampled_src_weights[bot_bx][bot_by][0],
									dx, dy))
								{
									full_encode_flag = true;
								}
								else
								{
									state.m_total_blocks_transcoded++;
								}
							}
							else
							{
								full_encode_flag = true;
							}

							if (full_encode_flag)
							{
								// one or both ASTC blocks are just too complex, unpack and reencode
								if (!has_unpacked_src_blocks[top_bx][top_by])
								{
									bool status = astc_helpers::decode_block_xuastc_ldr(*pB0, &unpacked_src_blocks[top_bx][top_by][0], 6, 6, astc_dec_mode, &upsampled_src_weights[top_bx][top_by][0]);
									if (!status)
									{
										return false;
									}
									state.m_total_src_blocks_unpacked++;
									has_unpacked_src_blocks[top_bx][top_by] = true;
								}

								if (!has_unpacked_src_blocks[bot_bx][bot_by])
								{
									bool status = astc_helpers::decode_block_xuastc_ldr(*pB1, &unpacked_src_blocks[bot_bx][bot_by][0], 6, 6, astc_dec_mode, &upsampled_src_weights[bot_bx][bot_by][0]);
									if (!status)
									{
										return false;
									}
									state.m_total_src_blocks_unpacked++;
									has_unpacked_src_blocks[bot_bx][bot_by] = true;
								}

								// TODO: Optimize
								for (uint32_t y = 0; y < 4; y++)
								{
									const uint32_t sy = dy * 4 + y;
									for (uint32_t x = 0; x < 4; x++)
									{
										const uint32_t sx = dx * 4 + x;

										assert(has_unpacked_src_blocks[sx / 6][sy / 6]);

										temp_pixels_16[x + y * 4] = unpacked_src_blocks[sx / 6][sy / 6][(sx % 6) + (sy % 6) * 6];
									} // x
								} // y

								if (state.m_has_alpha)
									bc7f::fast_pack_bc7_auto_rgba(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);
								else
									bc7f::fast_pack_bc7_auto_rgb(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);

								state.m_total_blocks_encoded++;
							}

						} // dx
					} // dy

					// Now handle the center BC7 block - by this point we may have already decoded 1 or more ASTC 6x6 blocks.
					const uint32_t dx = 1, dy = 1;
					const uint32_t dst_bx = ((src_bx * 6) >> 2) + dx;
					const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dy;

					if ((dst_bx < state.m_dst_num_blocks_x) && (dst_by < state.m_dst_num_blocks_y))
					{
						uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;

						bool skip_full_encode = false;

						// the unfortunate middle BC7 block, overlaps all 4 ASTC blocks
						// The 4 ASTC blocks cannot be all solid, and cannot be all hard.
						if (num_hard_src_blocks == 0)
						{
							// all blocks are simple, see if we can find a simple case to handle quickly
							bool top_same_solid_color = blocks_same_solid_colors(*pSrc_log_blocks[0][0], *pSrc_log_blocks[1][0], 1);
							bool bot_same_solid_color = blocks_same_solid_colors(*pSrc_log_blocks[0][1], *pSrc_log_blocks[1][1], 1);

							bool left_same_solid_color = blocks_same_solid_colors(*pSrc_log_blocks[0][0], *pSrc_log_blocks[0][1], 1);
							bool right_same_solid_color = blocks_same_solid_colors(*pSrc_log_blocks[1][0], *pSrc_log_blocks[1][1], 1);

							bool top_same_endpoints = blocks_same_single_subset_endpoints(*pSrc_log_blocks[0][0], *pSrc_log_blocks[1][0], ENDPOINT_TOL);
							bool bot_same_endpoints = blocks_same_single_subset_endpoints(*pSrc_log_blocks[0][1], *pSrc_log_blocks[1][1], ENDPOINT_TOL);

							bool left_same_endpoints = blocks_same_single_subset_endpoints(*pSrc_log_blocks[0][0], *pSrc_log_blocks[0][1], ENDPOINT_TOL);
							bool right_same_endpoints = blocks_same_single_subset_endpoints(*pSrc_log_blocks[1][0], *pSrc_log_blocks[1][1], ENDPOINT_TOL);

							bool top_no_alpha = !block_has_alpha(*pSrc_log_blocks[0][0]) && !block_has_alpha(*pSrc_log_blocks[1][0]);
							bool bot_no_alpha = !block_has_alpha(*pSrc_log_blocks[0][1]) && !block_has_alpha(*pSrc_log_blocks[1][1]);

							bool left_no_alpha = !block_has_alpha(*pSrc_log_blocks[0][0]) && !block_has_alpha(*pSrc_log_blocks[0][1]);
							bool right_no_alpha = !block_has_alpha(*pSrc_log_blocks[1][0]) && !block_has_alpha(*pSrc_log_blocks[1][1]);

							bool top_transcodable = (top_same_solid_color || top_same_endpoints) && top_no_alpha;
							bool bot_transcodable = (bot_same_solid_color || bot_same_endpoints) && bot_no_alpha;

							bool left_transcodable = (left_same_solid_color || left_same_endpoints) && left_no_alpha;
							bool right_transcodable = (right_same_solid_color || right_same_endpoints) && right_no_alpha;

							if (top_transcodable && bot_transcodable)
							{
								// BC7 mode 1
								bc7f::pack_astc_6x6_to_two_subsets_middle_block(
									pDst_block_u8,
									pSrc_log_blocks, upsampled_src_weights,
									false);
								state.m_total_blocks_transcoded++;
								skip_full_encode = true;
							}
							else if (left_transcodable && right_transcodable)
							{
								// BC7 mode 1
								bc7f::pack_astc_6x6_to_two_subsets_middle_block(
									pDst_block_u8,
									pSrc_log_blocks, upsampled_src_weights,
									true);
								state.m_total_blocks_transcoded++;
								skip_full_encode = true;
							}

							// TODO: Handle non-exact cases
						}

						if (!skip_full_encode)
						{
							// Center BC7 block scenario is complex, requires full decode+analytical BC7 encode.
							if (has_unpacked_src_blocks[0][0] && has_unpacked_src_blocks[1][0] && has_unpacked_src_blocks[0][1] && has_unpacked_src_blocks[1][1])
							{
								// We've already decoded all the ASTC 6x6 blocks fully, so grab central pixels
								for (uint32_t y = 0; y < 4; y++)
								{
									const uint32_t sy = dy * 4 + y;
									for (uint32_t x = 0; x < 4; x++)
									{
										const uint32_t sx = dx * 4 + x;

										temp_pixels_16[x + y * 4] = unpacked_src_blocks[sx / 6][sy / 6][(sx % 6) + (sy % 6) * 6];
									} // x
								} // y

								if (state.m_has_alpha)
									bc7f::fast_pack_bc7_auto_rgba(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);
								else
									bc7f::fast_pack_bc7_auto_rgb(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);

								state.m_total_blocks_encoded++;
							}
							else
							{
								for (uint32_t iby = 0; iby < 2; iby++)
								{
									for (uint32_t ibx = 0; ibx < 2; ibx++)
									{
										// Do a partial decode of the ASTC block, just to get those central pixels (big savings)
										uint32_t start_x, start_y, end_x, end_y;

										switch (ibx + iby * 2)
										{
										case 0: start_x = 4; end_x = 6; start_y = 4; end_y = 6; break;
										case 1: start_x = 0; end_x = 2; start_y = 4; end_y = 6; break;
										case 2: start_x = 4; end_x = 6; start_y = 0; end_y = 2; break;
										default:
										case 3: start_x = 0; end_x = 2; start_y = 0; end_y = 2; break;
										}

										// See if we've already decoded the block
										if (has_unpacked_src_blocks[ibx][iby])
										{
											for (uint32_t py = 0; py < 2; py++)
											{
												const uint32_t sy = start_y + py;

												for (uint32_t px = 0; px < 2; px++)
												{
													const uint32_t sx = start_x + px;

													temp_pixels_16[(px + ibx * 2) + (py + iby * 2) * 4] = unpacked_src_blocks[ibx][iby][(sx % 6) + (sy % 6) * 6];
												} // x
											} // y
										}
										else
										{
											// Partial decode
											color_rgba temp_pixels[6 * 6];

											bool status = astc_helpers::decode_block_xuastc_ldr(*pSrc_log_blocks[ibx][iby], temp_pixels, 6, 6, astc_dec_mode,
												&upsampled_src_weights[ibx][iby][0], start_x, start_y, end_x, end_y);
											if (!status)
											{
												return false;
											}
											state.m_total_src_blocks_partial_unpacked++;

											for (uint32_t py = 0; py < 2; py++)
											{
												const uint32_t ey = py + iby * 2;

												for (uint32_t px = 0; px < 2; px++)
												{
													const uint32_t ex = px + ibx * 2;

													temp_pixels_16[ex + ey * 4] = temp_pixels[(start_x + px) + (start_y + py) * 6];
												} // x
											} // y
										}
									} // x
								} // y

								if (state.m_has_alpha)
									bc7f::fast_pack_bc7_auto_rgba(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);
								else
									bc7f::fast_pack_bc7_auto_rgb(pDst_block_u8, temp_pixels_16, state.m_bc7f_flags);

								state.m_total_blocks_encoded++;
							}

						} // skip_full_encode

					} // if ((dst_bx < state.m_dst_num_blocks_x) && (dst_by < state.m_dst_num_blocks_y))

				} // src_bx

				return true;
			};

			xuastc_decoded_image decoded_image;

			const bool decomp_flag = decoded_image.decode(pImage_data, image_data_size, init_func, &dec_state, src_block_func, &dec_state);
			if (!decomp_flag)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_ldr_t::decompress_image() failed\n");
				return false;
			}

			if (basisu::g_debug_printf)
			{
				basisu::fmt_debug_printf("Total src blocks: {}, Total src blocks unpacked to pixels: {}, total partial unpacks: {}\n",
					dec_state.m_src_num_blocks_x * dec_state.m_src_num_blocks_y,
					dec_state.m_total_src_blocks_unpacked, dec_state.m_total_src_blocks_partial_unpacked);

				basisu::fmt_debug_printf("Total dst blocks: {}, Total blocks transcoded: {}, encoded: {}\n", 
					dec_state.m_dst_num_blocks_x * dec_state.m_dst_num_blocks_y,
					dec_state.m_total_blocks_transcoded, dec_state.m_total_blocks_encoded);
			}
		}
		else if (((src_block_width == 4) && (src_block_height == 4)) && (!dst_fmt_is_pvrtc1) && (!deblock_filtering))
		{
			// src is ASTC LDR 4x4, destination block size must be 4x4, no PVRTC1, no deblocking. Directly pack to target format during transcoding.
			struct decode_state
			{
				uint32_t m_src_num_blocks_x;
				uint32_t m_src_num_blocks_y;

				void* m_pDst_blocks;
				uint32_t m_output_row_pitch_in_blocks_or_pixels;
				uint32_t m_output_block_or_pixel_stride_in_bytes;
				uint32_t m_output_rows_in_pixels;

				block_format m_fmt;
				bool m_used_srgb_astc_decode_mode;
				bool m_has_alpha;

				int m_channel0, m_channel1;
				bool m_high_quality;
				bool m_enable_fast_bc7_transcoding;
				bool m_from_alpha;
				uint32_t m_bc7f_flags;
				etc1f::pack_etc1_state* m_pEtc1_pack_state;
			};

			decode_state dec_state;
			dec_state.m_src_num_blocks_x = src_num_blocks_x;
			dec_state.m_src_num_blocks_y = src_num_blocks_y;
			dec_state.m_pDst_blocks = pDst_blocks;
			dec_state.m_output_row_pitch_in_blocks_or_pixels = output_row_pitch_in_blocks_or_pixels;
			dec_state.m_output_block_or_pixel_stride_in_bytes = output_block_or_pixel_stride_in_bytes;
			dec_state.m_output_rows_in_pixels = output_rows_in_pixels;
			dec_state.m_fmt = fmt;
			dec_state.m_used_srgb_astc_decode_mode = false; // will be set by init from the compressed stream's header
			dec_state.m_has_alpha = true; // will be set by init from the compressed stream's header
			
			dec_state.m_channel0 = channel0;
			dec_state.m_channel1 = channel1;
			dec_state.m_high_quality = high_quality;
			dec_state.m_enable_fast_bc7_transcoding = enable_fast_bc7_transcoding;
			dec_state.m_from_alpha = from_alpha;
			dec_state.m_bc7f_flags = bc7f_flags;
			dec_state.m_pEtc1_pack_state = &etc1_pack_state;

			auto init_func = [](uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t block_width, uint32_t block_height, bool srgb_decode_profile, float dct_q, bool has_alpha, void* pData)
			{
				BASISU_NOTE_UNUSED(srgb_decode_profile);
				BASISU_NOTE_UNUSED(dct_q);
								
				if (basisu::g_debug_printf)
					basisu::debug_printf("init_func: %u %u %u %u %u %f %u\n", num_blocks_x, num_blocks_y, block_width, block_height, srgb_decode_profile, dct_q, has_alpha);

				decode_state& state = *(decode_state*)pData;
				if ((block_width != 4) || (block_height != 4))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (3)\n");
					return false;
				}
				if ((num_blocks_x != state.m_src_num_blocks_x) || (num_blocks_y != state.m_src_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (4)\n");
					return false;
				}
				
				state.m_used_srgb_astc_decode_mode = srgb_decode_profile;
				state.m_has_alpha = has_alpha;

				return true;
			};

			auto src_block_func = [](uint32_t bx, uint32_t by, const astc_helpers::log_astc_block& log_blk, void* pData)
			{
				decode_state& state = *(decode_state*)pData;
				assert((bx < state.m_src_num_blocks_x) && (by < state.m_src_num_blocks_y));

				uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (by * state.m_output_row_pitch_in_blocks_or_pixels + bx) * state.m_output_block_or_pixel_stride_in_bytes;

				// Special fast cases for BC7 transcode target given common ASTC configs
				if (state.m_fmt == block_format::cBC7)
				{
					if (log_blk.m_solid_color_flag_ldr)
					{
						color_rgba sc;
						sc.r = (uint8_t)(log_blk.m_solid_color[0] >> 8);
						sc.g = (uint8_t)(log_blk.m_solid_color[1] >> 8);
						sc.b = (uint8_t)(log_blk.m_solid_color[2] >> 8);
						sc.a = (uint8_t)(log_blk.m_solid_color[3] >> 8);

						bc7f::pack_mode5_solid(pDst_block_u8, sc);
						return true;
					}
					else if (!log_blk.m_dual_plane && (log_blk.m_num_partitions == 1) && !state.m_high_quality && state.m_enable_fast_bc7_transcoding)
					{
						// TODO: This does cost a tiny amount of PSNR (.1-25 dB or so), but is way faster.
						bc7f::pack_from_astc_4x4_single_subset(pDst_block_u8, log_blk);
						return true;
					}
				}

				// Fall back to block pixel unpack then analytical encode.
				color32 block_pixels[4 * 4];
				bool decode_status = astc_helpers::decode_block_xuastc_ldr(log_blk, block_pixels, 4, 4, state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8);
				if (!decode_status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block_xuastc_ldr() failed\n");
					return false;
				}

#if defined(_DEBUG) || defined(DEBUG)
				color32 alt_block_pixels[4 * 4];
				if (!astc_helpers::decode_block(log_blk, alt_block_pixels, 4, 4, state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block() failed\n");
					return false;
				}

				for (uint32_t i = 0; i < 16; i++)
				{
					assert(block_pixels[i][0] == alt_block_pixels[i][0]);
					assert(block_pixels[i][1] == alt_block_pixels[i][1]);
					assert(block_pixels[i][2] == alt_block_pixels[i][2]);
					assert(block_pixels[i][3] == alt_block_pixels[i][3]);
				}
#endif
								
				transcode_4x4_block(
					state.m_fmt,
					bx, by,
					state.m_pDst_blocks, pDst_block_u8,
					block_pixels,
					state.m_output_block_or_pixel_stride_in_bytes, state.m_output_row_pitch_in_blocks_or_pixels, state.m_output_rows_in_pixels,
					state.m_channel0, state.m_channel1,
					state.m_high_quality, state.m_from_alpha,
					state.m_bc7f_flags,
					*state.m_pEtc1_pack_state,
					state.m_has_alpha ? 1 : 0);

				return true;
			};

			xuastc_decoded_image decoded_image;

			const bool decomp_flag = decoded_image.decode(pImage_data, image_data_size, init_func, &dec_state, src_block_func, &dec_state);
			if (!decomp_flag)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_ldr_t::decompress_image() failed\n");
				return false;
			}
		}
		else if ((deblock_filtering) || (dst_fmt_is_pvrtc1))
		{
			// Completely general case. Unpack entire 32bpp image into memory (needed for deblocking and PVRTC1).
			assert((dst_fmt_block_width == 4) && (dst_fmt_block_height == 4));
			basisu::vector2D<color32> temp_image;

			if (!temp_image.try_resize(src_num_blocks_x * src_block_width, src_num_blocks_y * src_block_height))
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: out of memory\n");
				return false;
			}

			struct decode_state
			{
				uint32_t m_src_num_blocks_x;
				uint32_t m_src_num_blocks_y;
				uint32_t m_src_block_width;
				uint32_t m_src_block_height;

				void* m_pDst_blocks;
				uint32_t m_output_row_pitch_in_blocks_or_pixels;
				uint32_t m_output_block_or_pixel_stride_in_bytes;
				uint32_t m_output_rows_in_pixels;

				basisu::vector2D<color32>* m_pTemp_image;
								
				bool m_used_srgb_astc_decode_mode;
				bool m_has_alpha;
			};

			decode_state dec_state;
			dec_state.m_src_num_blocks_x = src_num_blocks_x;
			dec_state.m_src_num_blocks_y = src_num_blocks_y;
			dec_state.m_src_block_width = src_block_width;
			dec_state.m_src_block_height = src_block_height;
			dec_state.m_pDst_blocks = pDst_blocks;
			dec_state.m_output_row_pitch_in_blocks_or_pixels = output_row_pitch_in_blocks_or_pixels;
			dec_state.m_output_block_or_pixel_stride_in_bytes = output_block_or_pixel_stride_in_bytes;
			dec_state.m_output_rows_in_pixels = output_rows_in_pixels;
			dec_state.m_pTemp_image = &temp_image;
			dec_state.m_used_srgb_astc_decode_mode = false; // will be set by init from the compressed stream's header
			dec_state.m_has_alpha = true; // will be set by init from the compressed stream's header

			auto init_func = [](uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t block_width, uint32_t block_height, bool srgb_decode_profile, float dct_q, bool has_alpha, void* pData)
			{
				BASISU_NOTE_UNUSED(srgb_decode_profile);
				BASISU_NOTE_UNUSED(dct_q);
				
				if (basisu::g_debug_printf)
					basisu::debug_printf("init_func: %u %u %u %u %u %f %u\n", num_blocks_x, num_blocks_y, block_width, block_height, srgb_decode_profile, dct_q, has_alpha);

				decode_state& state = *(decode_state*)pData;
				if ((block_width != state.m_src_block_width) || (block_height != state.m_src_block_height))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (3)\n");
					return false;
				}
				if ((num_blocks_x != state.m_src_num_blocks_x) || (num_blocks_y != state.m_src_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (4)\n");
					return false;
				}

				state.m_used_srgb_astc_decode_mode = srgb_decode_profile;
				state.m_has_alpha = has_alpha;

				return true;
			};

			auto src_block_func = [](uint32_t bx, uint32_t by, const astc_helpers::log_astc_block& log_blk, void* pData)
			{
				decode_state& state = *(decode_state*)pData;
				assert((bx < state.m_src_num_blocks_x) && (by < state.m_src_num_blocks_y));

				color32 block_pixels[astc_helpers::MAX_BLOCK_PIXELS];
				bool decode_status = astc_helpers::decode_block_xuastc_ldr(log_blk, block_pixels, state.m_src_block_width, state.m_src_block_height, state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8);
				if (!decode_status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block_xuastc_ldr() failed\n");
					return false;
				}

#if defined(_DEBUG) || defined(DEBUG)
				// sanity check vs. our vanilla/full-featured ASTC decoder
				color32 alt_block_pixels[astc_helpers::MAX_BLOCK_PIXELS];
				if (!astc_helpers::decode_block(log_blk, alt_block_pixels, state.m_src_block_width, state.m_src_block_height, state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block() failed\n");
					return false;
				}

				for (uint32_t i = 0; i < state.m_src_block_width * state.m_src_block_height; i++)
				{
					assert(block_pixels[i][0] == alt_block_pixels[i][0]);
					assert(block_pixels[i][1] == alt_block_pixels[i][1]);
					assert(block_pixels[i][2] == alt_block_pixels[i][2]);
					assert(block_pixels[i][3] == alt_block_pixels[i][3]);
				}
#endif

				color32* pSrc_pixels = block_pixels;
				color32* pDst_pixels = &(*state.m_pTemp_image)(bx * state.m_src_block_width, by * state.m_src_block_height);

				for (uint32_t y = 0; y < state.m_src_block_height; y++)
				{
					memcpy(pDst_pixels, pSrc_pixels, state.m_src_block_width * sizeof(color32));

					pSrc_pixels += state.m_src_block_width;
					pDst_pixels += state.m_pTemp_image->get_width();
				} // y
				
				return true;
			};

			xuastc_decoded_image decoded_image;

			const bool decomp_flag = decoded_image.decode(pImage_data, image_data_size, init_func, &dec_state, src_block_func, &dec_state);
			if (!decomp_flag)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_ldr_t::decompress_image() failed\n");
				return false;
			}

			if (deblock_filtering)
			{
				if (!xuastc_deblock_filter(
					decoded_image.m_actual_block_width, decoded_image.m_actual_block_height,
					temp_image, temp_image))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: out of memory\n");
					return false;
				}
			}

			const uint32_t dst_num_blocks_x = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
			const uint32_t dst_num_blocks_y = (orig_height + dst_fmt_block_height - 1) / dst_fmt_block_height;

			if (dst_fmt_is_pvrtc1)
			{
				assert((dst_fmt_block_width == 4) && (dst_fmt_block_height == 4));

				encode_pvrtc1(fmt, pDst_blocks, temp_image, dst_num_blocks_x, dst_num_blocks_y, from_alpha);
			}
			else
			{
				color32 block_pixels[astc_helpers::MAX_BLOCK_PIXELS];

				for (uint32_t dst_by = 0; dst_by < dst_num_blocks_y; dst_by++)
				{
					uint8_t* pDst_block_u8 = (uint8_t*)pDst_blocks + dst_by * output_row_pitch_in_blocks_or_pixels * output_block_or_pixel_stride_in_bytes;

					for (uint32_t dst_bx = 0; dst_bx < dst_num_blocks_x; dst_bx++)
					{
						temp_image.extract_block_clamped(block_pixels, dst_bx * 4, dst_by * 4, 4, 4);

						transcode_4x4_block(
							fmt,
							dst_bx, dst_by,
							pDst_blocks, pDst_block_u8,
							block_pixels,
							output_block_or_pixel_stride_in_bytes, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels,
							channel0, channel1,
							high_quality, from_alpha,
							bc7f_flags,
							etc1_pack_state, 
							dec_state.m_has_alpha ? 1 : 0);

						pDst_block_u8 += output_block_or_pixel_stride_in_bytes;

					} // dst_bx

				} // dst_by

			} // if (dst_fmt_is_pvrtc1)
		}
		else
		{
			// No PVRTC1/ASTC, no deblocking. Unpack as few source row blocks into memory as possible needed for transcoding to 4x4. Output block size must be 4x4.
			assert((dst_fmt_block_width == 4) && (dst_fmt_block_height == 4));
			
			// Compute how many source block rows we need to buffer so we have a multiple of 4 scanlines. The max # of scanlines is 20.
			uint32_t num_src_block_rows_to_buffer = 1;
			while ((num_src_block_rows_to_buffer * src_block_height) & 3)
				num_src_block_rows_to_buffer++;
			assert((num_src_block_rows_to_buffer >= 1) && (num_src_block_rows_to_buffer <= 4));

			// Compute how many 4x4 dest blocks fit into these many source rows.
			assert(((num_src_block_rows_to_buffer * src_block_height) & 3) == 0);
			//const uint32_t num_dst_block_rows_to_buffer = (num_src_block_rows_to_buffer * src_block_height) >> 2;

			const uint32_t dst_num_blocks_x = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
			const uint32_t dst_num_blocks_y = (orig_height + dst_fmt_block_height - 1) / dst_fmt_block_height;

			basisu::vector2D<color32> buffered_rows(src_num_blocks_x * src_block_width, num_src_block_rows_to_buffer * src_block_height);

			struct decode_state
			{
				uint32_t m_orig_height;

				uint32_t m_src_num_blocks_x;
				uint32_t m_src_num_blocks_y;
				uint32_t m_src_block_width;
				uint32_t m_src_block_height;

				uint32_t m_dst_num_blocks_x;
				uint32_t m_dst_num_blocks_y;

				void* m_pDst_blocks;
				uint32_t m_output_row_pitch_in_blocks_or_pixels;
				uint32_t m_output_block_or_pixel_stride_in_bytes;
				uint32_t m_output_rows_in_pixels;

				uint32_t m_num_src_block_rows_to_buffer;
				//uint32_t m_num_dst_block_rows_to_buffer;

				basisu::vector2D<color32>* m_pBuffered_rows;

				bool m_used_srgb_astc_decode_mode;
				bool m_has_alpha;

				block_format m_fmt;
				int m_channel0, m_channel1;
				bool m_high_quality;
				bool m_from_alpha;
				uint32_t m_bc7f_flags;
				etc1f::pack_etc1_state* m_pEtc1_pack_state;
			};

			decode_state dec_state;
			dec_state.m_orig_height = orig_height;
			dec_state.m_src_num_blocks_x = src_num_blocks_x;
			dec_state.m_src_num_blocks_y = src_num_blocks_y;
			dec_state.m_src_block_width = src_block_width;
			dec_state.m_src_block_height = src_block_height;
			dec_state.m_dst_num_blocks_x = dst_num_blocks_x;
			dec_state.m_dst_num_blocks_y = dst_num_blocks_y;
			dec_state.m_pDst_blocks = pDst_blocks;
			dec_state.m_output_row_pitch_in_blocks_or_pixels = output_row_pitch_in_blocks_or_pixels;
			dec_state.m_output_block_or_pixel_stride_in_bytes = output_block_or_pixel_stride_in_bytes;
			dec_state.m_output_rows_in_pixels = output_rows_in_pixels;

			dec_state.m_num_src_block_rows_to_buffer = num_src_block_rows_to_buffer;
			//dec_state.m_num_dst_block_rows_to_buffer = num_dst_block_rows_to_buffer;

			dec_state.m_pBuffered_rows = &buffered_rows;
			dec_state.m_used_srgb_astc_decode_mode = false; // will be set by init from the compressed stream's header
			dec_state.m_has_alpha = true; // will be set by init from the compressed stream's header

			dec_state.m_fmt = fmt;
			dec_state.m_channel0 = channel0;
			dec_state.m_channel1 = channel1;
			dec_state.m_high_quality = high_quality;
			dec_state.m_from_alpha = from_alpha;
			dec_state.m_bc7f_flags = bc7f_flags;
			dec_state.m_pEtc1_pack_state = &etc1_pack_state;

			auto init_func = [](uint32_t num_blocks_x, uint32_t num_blocks_y, uint32_t block_width, uint32_t block_height, bool srgb_decode_profile, float dct_q, bool has_alpha, void* pData)
			{
				BASISU_NOTE_UNUSED(srgb_decode_profile);
				BASISU_NOTE_UNUSED(dct_q);
				
				if (basisu::g_debug_printf)
					basisu::debug_printf("init_func: %u %u %u %u %u %f %u\n", num_blocks_x, num_blocks_y, block_width, block_height, srgb_decode_profile, dct_q, has_alpha);

				decode_state& state = *(decode_state*)pData;
				if ((block_width != state.m_src_block_width) || (block_height != state.m_src_block_height))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (3)\n");
					return false;
				}
				if ((num_blocks_x != state.m_src_num_blocks_x) || (num_blocks_y != state.m_src_num_blocks_y))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: header validation failed (4)\n");
					return false;
				}

				state.m_used_srgb_astc_decode_mode = srgb_decode_profile;
				state.m_has_alpha = has_alpha;

				return true;
			};

			auto src_block_func = [](uint32_t bx, uint32_t by, const astc_helpers::log_astc_block& log_blk, void* pData)
			{
				decode_state& state = *(decode_state*)pData;
				assert((bx < state.m_src_num_blocks_x) && (by < state.m_src_num_blocks_y));

				// Unpack ASTC block, distribute to temp output buffer.
				color32 block_pixels[astc_helpers::MAX_BLOCK_PIXELS];
				bool decode_status = astc_helpers::decode_block_xuastc_ldr(log_blk, block_pixels, state.m_src_block_width, state.m_src_block_height, state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8);
				if (!decode_status)
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block_xuastc_ldr() failed\n");
					return false;
				}

#if defined(_DEBUG) || defined(DEBUG)
				color32 alt_block_pixels[astc_helpers::MAX_BLOCK_PIXELS];
				if (!astc_helpers::decode_block(log_blk, alt_block_pixels, state.m_src_block_width, state.m_src_block_height, state.m_used_srgb_astc_decode_mode ? astc_helpers::cDecodeModeSRGB8 : astc_helpers::cDecodeModeLDR8))
				{
					BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_helpers::decode_block() failed\n");
					return false;
				}

				for (uint32_t i = 0; i < state.m_src_block_width * state.m_src_block_height; i++)
				{
					assert(block_pixels[i][0] == alt_block_pixels[i][0]);
					assert(block_pixels[i][1] == alt_block_pixels[i][1]);
					assert(block_pixels[i][2] == alt_block_pixels[i][2]);
					assert(block_pixels[i][3] == alt_block_pixels[i][3]);
				}
#endif

				// TODO: For uncompressed outputs, we could write directly to the output buffer, skipping buffering.
				const uint32_t buffered_src_block_row_y = (by % state.m_num_src_block_rows_to_buffer);

				color32* pSrc_pixels = block_pixels;
				color32* pDst_pixels = &(*state.m_pBuffered_rows)(bx * state.m_src_block_width, buffered_src_block_row_y * state.m_src_block_height);

				for (uint32_t y = 0; y < state.m_src_block_height; y++)
				{
					memcpy(pDst_pixels, pSrc_pixels, state.m_src_block_width * sizeof(color32));

					pSrc_pixels += state.m_src_block_width;
					pDst_pixels += state.m_pBuffered_rows->get_width();
				} // y

				// Last block on this src row? If not, exit.
				if (bx != (state.m_src_num_blocks_x - 1))
					return true;

				// We've written the final src block for this ASTC src row. 
				// See if we have enough source rows to create full 4x4 destination blocks.
				const bool final_src_block_row = (by == (state.m_src_num_blocks_y - 1));

				if ( (buffered_src_block_row_y != (state.m_num_src_block_rows_to_buffer - 1)) && (!final_src_block_row) )
					return true;

				// src/destination image Y coordinate of the top of the buffered rows
				const uint32_t buffered_src_pixel_y = ((by / state.m_num_src_block_rows_to_buffer) * state.m_num_src_block_rows_to_buffer) * state.m_src_block_height;
				assert((buffered_src_pixel_y & 3) == 0);

				// The total # of valid src block rows we can read.
				const uint32_t num_buffered_src_block_rows = buffered_src_block_row_y + 1;

				assert((num_buffered_src_block_rows == state.m_num_src_block_rows_to_buffer) || (final_src_block_row));

				// The maximum number of valid buffer scanlines we can fetch from, taking into account the original texture's actual (unpadded) height.
				const uint32_t override_buffer_height = basisu::minimum(state.m_orig_height - buffered_src_pixel_y, num_buffered_src_block_rows * state.m_src_block_height);
				assert(override_buffer_height);
				
				// total_dst_block_rows_to_emit=really an upper bound for the final row of src ASTC blocks
				const uint32_t total_dst_block_rows_to_emit = (num_buffered_src_block_rows * state.m_src_block_height + 3) >> 2;
				
				for (uint32_t dst_ofs_by = 0; dst_ofs_by < total_dst_block_rows_to_emit; dst_ofs_by++)
				{
					const uint32_t dst_by = (buffered_src_pixel_y >> 2) + dst_ofs_by;
					if (dst_by >= state.m_dst_num_blocks_y)
						break;

					for (uint32_t dst_bx = 0; dst_bx < state.m_dst_num_blocks_x; dst_bx++)
					{
						// Extract the 4x4 block pixels from our buffered rows, taking into account the actual # of valid scanlines inside the buffer.
						state.m_pBuffered_rows->extract_block_clamped(block_pixels, dst_bx * 4, dst_ofs_by * 4, 4, 4, override_buffer_height);

						uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + (dst_by * state.m_output_row_pitch_in_blocks_or_pixels + dst_bx) * state.m_output_block_or_pixel_stride_in_bytes;
												
						transcode_4x4_block(
							state.m_fmt,
							dst_bx, dst_by,
							state.m_pDst_blocks, pDst_block_u8,
							block_pixels,
							state.m_output_block_or_pixel_stride_in_bytes, state.m_output_row_pitch_in_blocks_or_pixels, state.m_output_rows_in_pixels,
							state.m_channel0, state.m_channel1,
							state.m_high_quality, state.m_from_alpha,
							state.m_bc7f_flags,
							*state.m_pEtc1_pack_state,
							state.m_has_alpha ? 1 : 0);

					} // dst_bx

				} // dst_ofs_by
								
				return true;
			};

			xuastc_decoded_image decoded_image;

			const bool decomp_flag = decoded_image.decode(pImage_data, image_data_size, init_func, &dec_state, src_block_func, &dec_state);
			if (!decomp_flag)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: astc_ldr_t::decompress_image() failed\n");
				return false;
			}
		}

	} // if (basis_tex_format_is_astc_ldr(src_format))

	return true;
#else
	assert(0);
	BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_slice: XUASTC support disabled\n");
	return false;
#endif // BASISD_SUPPORT_XUASTC
}

// Container independent transcoding
bool basisu_lowlevel_xuastc_ldr_transcoder::transcode_image(
	basis_tex_format src_format, bool use_astc_srgb_decode_profile,
	transcoder_texture_format target_format,
	void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
	const uint8_t* pCompressed_data, uint32_t compressed_data_length,
	uint32_t src_num_blocks_x, uint32_t src_num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
	uint64_t slice_offset, uint32_t slice_length,
	uint32_t decode_flags,
	bool has_alpha,
	bool is_video,
	uint32_t output_row_pitch_in_blocks_or_pixels,
	basisu_transcoder_state* pState,
	uint32_t output_rows_in_pixels,
	int channel0, int channel1)
{
	BASISU_NOTE_UNUSED(is_video);
	BASISU_NOTE_UNUSED(level_index);

#if BASISD_SUPPORT_XUASTC

	if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: source data buffer too small\n");
		return false;
	}

	if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
	{
		if ((!basisu::is_pow2(orig_width)) || (!basisu::is_pow2(orig_height)))
		{
			// PVRTC1 only supports power of 2 dimensions
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 only supports power of 2 dimensions\n");
			return false;
		}
	}

	const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
	const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);

	if (!basis_validate_output_buffer_size(target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: output buffer size too small\n");
		return false;
	}

	bool status = false;

	switch (target_format)
	{
	case transcoder_texture_format::cTFETC1_RGB:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC1,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to ETC1 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFETC2_RGBA:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_RGBA,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to ETC2 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC1_RGB:
	{
		// TODO: ETC1S allows BC1 from alpha channel. That doesn't seem actually useful, though.
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC1,
			bytes_per_block_or_pixel, true, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to BC1 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC3_RGBA:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC3,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to BC3 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC4_R:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC4,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to BC4 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC5_RG:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC5,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			0, 3, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to BC5 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC7_RGBA:
	case transcoder_texture_format::cTFBC7_ALT:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC7,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to BC7 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFPVRTC1_4_RGB:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGB,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to PVRTC1_RGB failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFPVRTC1_4_RGBA:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGBA,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to PVRTC1_RGBA failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_5x4_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_5x5_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_6x5_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_6x6_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_8x5_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_8x6_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_10x5_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_10x6_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_8x8_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_10x8_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_10x10_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_12x10_RGBA:
	case transcoder_texture_format::cTFASTC_LDR_12x12_RGBA:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, xuastc_get_block_format(target_format),
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to ASTC failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFATC_RGB:
	case transcoder_texture_format::cTFATC_RGBA:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: UASTC LDR 4x4->ATC currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFFXT1_RGB:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: UASTC LDR 4x4->FXT1 currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFPVRTC2_4_RGB:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: UASTC LDR 4x4->PVRTC2 currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFPVRTC2_4_RGBA:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: UASTC LDR 4x4->PVRTC2 currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFETC2_EAC_R11:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_R11,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to EAC R11 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFETC2_EAC_RG11:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_RG11,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			0, 3, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to EAC RG11 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFRGBA32:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA32,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to RGBA32 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFRGB565:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB565,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBGR565:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBGR565,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFRGBA4444:
	{
		status = transcode_slice(src_format, use_astc_srgb_decode_profile, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA4444,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: transcode_slice() to RGBA4444 failed\n");
		}
		break;
	}
	default:
	{
		assert(0);
		BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: Invalid format\n");
		break;
	}
	}

	// PVRTC1 levels smaller than 8x8 texels: fill the 2x2 block minimum (see pvrtc1_4_tile_small_level()).
	if (status && ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA)))
		pvrtc1_4_tile_small_level(pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, (orig_width + 3) >> 2, (orig_height + 3) >> 2);

	return status;
#else
	assert(0);
	BASISU_DEVEL_ERROR("basisu_lowlevel_xuastc_ldr_transcoder::transcode_image: XUASTC/XUBC7 support disabled\n");
	return false;
#endif // BASISD_SUPPORT_XUASTC
}

// ---- XUBC7 transcoding
basisu_lowlevel_xubc7_transcoder::basisu_lowlevel_xubc7_transcoder()
{
}

bool basisu_lowlevel_xubc7_transcoder::transcode_slice(
	basis_tex_format src_tex_format, 
	void* pDst_blocks,
	uint32_t src_num_blocks_x, uint32_t src_num_blocks_y,
	const uint8_t* pImage_data, uint32_t image_data_size, block_format fmt,
	uint32_t output_block_or_pixel_stride_in_bytes, bool bc1_allow_threecolor_blocks, bool has_alpha,
	const uint32_t orig_width, const uint32_t orig_height, uint32_t output_row_pitch_in_blocks_or_pixels,
	basisu_transcoder_state* pState, uint32_t output_rows_in_pixels, int channel0, int channel1, uint32_t decode_flags)
{
	BASISU_NOTE_UNUSED(pState);
	BASISU_NOTE_UNUSED(bc1_allow_threecolor_blocks);
	BASISU_NOTE_UNUSED(src_tex_format);
	
	assert(src_tex_format == basis_tex_format::cXUBC7);
	
#if BASISD_SUPPORT_XUASTC

	assert(g_transcoder_initialized);
	if (!g_transcoder_initialized)
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: Transcoder not globally initialized.\n");
		return false;
	}

	if (block_format_is_hdr(fmt))
	{
		assert(0);
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: Invalid fmt argument\n");
		return false;
	}

	//const uint32_t total_blocks = num_blocks_x * num_blocks_y;

	//const uint32_t src_block_width = basis_tex_format_get_block_width(src_format), src_block_height = basis_tex_format_get_block_height(src_format);

	const uint32_t dst_fmt_block_width = get_block_width(fmt), dst_fmt_block_height = get_block_height(fmt);
	BASISU_NOTE_UNUSED(dst_fmt_block_height);
	
	if ((dst_fmt_block_width != 4) || (dst_fmt_block_height != 4))
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: Can only transcode to 4x4 block sizes\n");
	}

	const bool dst_fmt_is_astc = block_format_is_astc(fmt);
	
	if (dst_fmt_is_astc)
	{
		if (fmt != block_format::cASTC_LDR_4x4)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: ASTC LDR must be 4x4 only\n");
			return false;
		}
	}

	const bool dst_fmt_is_pvrtc1 = (fmt == block_format::cPVRTC1_4_RGB) || (fmt == block_format::cPVRTC1_4_RGBA);

	if (dst_fmt_is_pvrtc1)
	{
		if (!basisu::is_pow2(orig_width) || !basisu::is_pow2(orig_height))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: PVRTC1 requires power of 2 texture dimensions\n");
			return false;
		}
	}

	const bool is_uncompressed_fmt = basis_block_format_is_uncompressed(fmt);
	if (!output_row_pitch_in_blocks_or_pixels)
	{
		if (is_uncompressed_fmt)
			output_row_pitch_in_blocks_or_pixels = orig_width;
		else
			output_row_pitch_in_blocks_or_pixels = (orig_width + dst_fmt_block_width - 1) / dst_fmt_block_width;
	}

	if (is_uncompressed_fmt)
	{
		if (!output_rows_in_pixels)
			output_rows_in_pixels = orig_height;
	}

	const bool high_quality = (decode_flags & cDecodeFlagsHighQuality) != 0;
	const uint32_t bc7f_override_flags = high_quality ? bc7f::cPackBC7FlagDefaultPartiallyAnalytical : bc7f::cPackBC7FlagDefault;

	const bool from_alpha = has_alpha && (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
		
	etc1f::pack_etc1_state etc1_pack_state;
	basisu::vector2D<color32> temp_image; // only for PVRTC1

	if (dst_fmt_is_pvrtc1)
	{
		if (!temp_image.try_resize(src_num_blocks_x * 4, src_num_blocks_y * 4))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: out of memory allocating PVRTC1 temp buffer\n");
			return false;
		}
	}

	struct decode_state
	{
		uint32_t m_src_num_blocks_x;
		uint32_t m_src_num_blocks_y;
		bool m_has_alpha;

		void* m_pDst_blocks;
		uint32_t m_output_row_pitch_in_blocks_or_pixels;
		uint32_t m_output_block_or_pixel_stride_in_bytes;
		uint32_t m_output_rows_in_pixels;

		basisu::vector2D<color32>* m_pTemp_image; // PVRTC1

		block_format m_fmt;
		int m_channel0, m_channel1;
		bool m_high_quality;
		bool m_from_alpha;
		etc1f::pack_etc1_state* m_pEtc1_pack_state;
		uint32_t m_bc7f_override_flags;
	};

	decode_state dec_state;
	dec_state.m_src_num_blocks_x = src_num_blocks_x;
	dec_state.m_src_num_blocks_y = src_num_blocks_y;
	dec_state.m_has_alpha = false;
	dec_state.m_pDst_blocks = pDst_blocks;
	dec_state.m_output_row_pitch_in_blocks_or_pixels = output_row_pitch_in_blocks_or_pixels;
	dec_state.m_output_block_or_pixel_stride_in_bytes = output_block_or_pixel_stride_in_bytes;
	dec_state.m_output_rows_in_pixels = output_rows_in_pixels;
	dec_state.m_pTemp_image = &temp_image;

	dec_state.m_fmt = fmt;
	dec_state.m_channel0 = channel0;
	dec_state.m_channel1 = channel1;
	dec_state.m_high_quality = high_quality;
	dec_state.m_from_alpha = from_alpha;
	dec_state.m_pEtc1_pack_state = &etc1_pack_state;
	dec_state.m_bc7f_override_flags = bc7f_override_flags;

	auto init_func = [](uint32_t num_blocks_x, uint32_t num_blocks_y,
		uint32_t width_in_texels, uint32_t height_in_texels,
		uint32_t dct_q, bool has_alpha, void* pData)
	{
		BASISU_NOTE_UNUSED(dct_q);
		BASISU_NOTE_UNUSED(width_in_texels);
		BASISU_NOTE_UNUSED(height_in_texels);

		if (basisu::g_debug_printf)
			basisu::debug_printf("init_func: %u %u %u %u\n", num_blocks_x, num_blocks_y, dct_q, has_alpha);

		decode_state& state = *(decode_state*)pData;
		if ((num_blocks_x != state.m_src_num_blocks_x) || (num_blocks_y != state.m_src_num_blocks_y))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: header validation failed (4)\n");
			return false;
		}

		state.m_has_alpha = has_alpha;

		return true;
	};

	auto src_block_bc7_func = [](uint32_t bx, uint32_t by, const basist::bc7u::log_bc7_block& log_blk, void* pData)
	{
		decode_state& state = *(decode_state*)pData;
		assert((bx < state.m_src_num_blocks_x) && (by < state.m_src_num_blocks_y));

		// BC7 is obviously easy for XUBC7
		if (state.m_fmt == block_format::cBC7)
		{
			basist::bc7_block* pDst_bc7_block = (basist::bc7_block*)((uint8_t*)state.m_pDst_blocks + (by * state.m_output_row_pitch_in_blocks_or_pixels + bx) * state.m_output_block_or_pixel_stride_in_bytes);

			bool pack_status = bc7u::pack_bc7(log_blk, pDst_bc7_block);
			if (!pack_status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: pack_bc7() failed\n");
				return false;
			}

			return true;
		}

		// ASTC LDR 4x4: usually latent to latent, but may fall back to bc7f for some 2/3 partition patterns that don't map losslessly to ASTC LDR 4x4 (low probability)
		if (state.m_fmt == block_format::cASTC_LDR_4x4)
		{
			astc_helpers::astc_block* pDst_astc_block = (astc_helpers::astc_block*)((uint8_t*)state.m_pDst_blocks + (by * state.m_output_row_pitch_in_blocks_or_pixels + bx) * state.m_output_block_or_pixel_stride_in_bytes);

			// TODO: fast_pack_astc() currently wants a physical BC7 block, not logical, which sucks
			basist::bc7_block phys_bc7_block;
			bool pack_status = bc7u::pack_bc7(log_blk, &phys_bc7_block);
			if (!pack_status)
			{
				BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: pack_bc7() failed\n");
				return false;
			}

			return bc7f::fast_pack_astc(pDst_astc_block, phys_bc7_block, state.m_bc7f_override_flags);
		}
		
		// it's not BC7 or ASTC LDR 4x4, so we need the block's texels
		color32 block_texels[16];
		if (!bc7u::unpack_bc7(log_blk, (color_rgba *)block_texels))
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: unpack_bc7() failed\n");
			return false;
		}

		if ((state.m_fmt == block_format::cPVRTC1_4_RGB) || (state.m_fmt == block_format::cPVRTC1_4_RGBA))
		{
			const uint32_t dst_x = bx * 4, dst_y = by * 4;

			assert((dst_x + 4) <= state.m_pTemp_image->get_width());
			assert((dst_y + 4) <= state.m_pTemp_image->get_height());

			for (uint32_t y = 0; y < 4; y++)
				for (uint32_t x = 0; x < 4; x++)
					(*state.m_pTemp_image)(dst_x + x, dst_y + y) = block_texels[x + y * 4];

			return true;
		}

		uint8_t* pDst_block_u8 = (uint8_t*)state.m_pDst_blocks + by * state.m_output_row_pitch_in_blocks_or_pixels * state.m_output_block_or_pixel_stride_in_bytes + bx * state.m_output_block_or_pixel_stride_in_bytes;
	
		return transcode_4x4_block(
			state.m_fmt,
			bx, by,
			state.m_pDst_blocks, pDst_block_u8,
			block_texels,
			state.m_output_block_or_pixel_stride_in_bytes, state.m_output_row_pitch_in_blocks_or_pixels, state.m_output_rows_in_pixels,
			state.m_channel0, state.m_channel1,
			state.m_high_quality, state.m_from_alpha,
			state.m_bc7f_override_flags, //bc7f::cPackBC7FlagDefault,
			*state.m_pEtc1_pack_state,
			state.m_has_alpha);
	};

	bool decomp_status = xbc7::unpack_image(xbc7::byte_span(pImage_data, image_data_size), init_func, &dec_state, src_block_bc7_func, &dec_state);
	if (!decomp_status)
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: xbc7::unpack_image() failed\n");
		return false;
	}

	if (dst_fmt_is_pvrtc1)
	{
		encode_pvrtc1(fmt, pDst_blocks, temp_image, src_num_blocks_x, src_num_blocks_y, from_alpha);
	}

	return true;
#else
	assert(0);
	BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_slice: XUASTC/XUBC7 support disabled\n");
	return false;
#endif
}

// Container independent transcoding
bool basisu_lowlevel_xubc7_transcoder::transcode_image(
	basis_tex_format src_tex_format, 
	transcoder_texture_format target_format,
	void* pOutput_blocks, uint32_t output_blocks_buf_size_in_blocks_or_pixels,
	const uint8_t* pCompressed_data, uint32_t compressed_data_length,
	uint32_t src_num_blocks_x, uint32_t src_num_blocks_y, uint32_t orig_width, uint32_t orig_height, uint32_t level_index,
	uint64_t slice_offset, uint32_t slice_length,
	uint32_t decode_flags,
	bool has_alpha,
	bool is_video,
	uint32_t output_row_pitch_in_blocks_or_pixels,
	basisu_transcoder_state* pState,
	uint32_t output_rows_in_pixels,
	int channel0, int channel1)
{
	BASISU_NOTE_UNUSED(is_video);
	BASISU_NOTE_UNUSED(level_index);

#if BASISD_SUPPORT_XUASTC

	if (((uint64_t)slice_offset + slice_length) > (uint64_t)compressed_data_length)
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: source data buffer too small\n");
		return false;
	}

	if ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA))
	{
		if ((!basisu::is_pow2(orig_width)) || (!basisu::is_pow2(orig_height)))
		{
			// PVRTC1 only supports power of 2 dimensions
			BASISU_DEVEL_ERROR("basisu_lowlevel_etc1s_transcoder::transcode_image: PVRTC1 only supports power of 2 dimensions\n");
			return false;
		}
	}

	const bool transcode_alpha_data_to_opaque_formats = (decode_flags & cDecodeFlagsTranscodeAlphaDataToOpaqueFormats) != 0;
	const uint32_t bytes_per_block_or_pixel = basis_get_bytes_per_block_or_pixel(target_format);

	if (!basis_validate_output_buffer_size(target_format, output_blocks_buf_size_in_blocks_or_pixels, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, output_rows_in_pixels))
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: output buffer size too small\n");
		return false;
	}

	bool status = false;

	switch (target_format)
	{
	case transcoder_texture_format::cTFETC1_RGB:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC1,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to ETC1 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFETC2_RGBA:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_RGBA,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to ETC2 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC1_RGB:
	{
		// TODO: ETC1S allows BC1 from alpha channel. That doesn't seem actually useful, though.
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC1,
			bytes_per_block_or_pixel, true, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to BC1 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC3_RGBA:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC3,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to BC3 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC4_R:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC4,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to BC4 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC5_RG:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC5,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			0, 3, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to BC5 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBC7_RGBA:
	case transcoder_texture_format::cTFBC7_ALT:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBC7,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to BC7 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFPVRTC1_4_RGB:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGB,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to PVRTC1_RGB failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFPVRTC1_4_RGBA:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cPVRTC1_4_RGBA,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, channel0, channel1, decode_flags);

		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to PVRTC1_RGBA failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFASTC_LDR_4x4_RGBA:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, xuastc_get_block_format(target_format),
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to ASTC 4x4 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFATC_RGB:
	case transcoder_texture_format::cTFATC_RGBA:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: UASTC LDR 4x4->ATC currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFFXT1_RGB:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: UASTC LDR 4x4->FXT1 currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFPVRTC2_4_RGB:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: UASTC LDR 4x4->PVRTC2 currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFPVRTC2_4_RGBA:
	{
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: UASTC LDR 4x4->PVRTC2 currently unsupported\n");
		return false;
	}
	case transcoder_texture_format::cTFETC2_EAC_R11:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_R11,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			((has_alpha) && (transcode_alpha_data_to_opaque_formats)) ? 3 : 0, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to EAC R11 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFETC2_EAC_RG11:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cETC2_EAC_RG11,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels,
			0, 3, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to EAC RG11 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFRGBA32:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA32,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to RGBA32 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFRGB565:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGB565,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFBGR565:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cBGR565,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to RGB565 failed\n");
		}
		break;
	}
	case transcoder_texture_format::cTFRGBA4444:
	{
		status = transcode_slice(src_tex_format, pOutput_blocks, src_num_blocks_x, src_num_blocks_y, pCompressed_data + slice_offset, slice_length, block_format::cRGBA4444,
			bytes_per_block_or_pixel, false, has_alpha, orig_width, orig_height, output_row_pitch_in_blocks_or_pixels, pState, output_rows_in_pixels, -1, -1, decode_flags);
		if (!status)
		{
			BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: transcode_slice() to RGBA4444 failed\n");
		}
		break;
	}
	default:
	{
		assert(0);
		BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: Invalid format\n");
		break;
	}
	}

	// PVRTC1 levels smaller than 8x8 texels: fill the 2x2 block minimum (see pvrtc1_4_tile_small_level()).
	if (status && ((target_format == transcoder_texture_format::cTFPVRTC1_4_RGB) || (target_format == transcoder_texture_format::cTFPVRTC1_4_RGBA)))
		pvrtc1_4_tile_small_level(pOutput_blocks, output_blocks_buf_size_in_blocks_or_pixels, (orig_width + 3) >> 2, (orig_height + 3) >> 2);

	return status;
#else
	assert(0);
	BASISU_DEVEL_ERROR("basisu_lowlevel_xubc7_transcoder::transcode_image: XUASTC/XUBC7 support disabled\n");
	return false;
#endif // BASISD_SUPPORT_XUASTC
}

} // namespace basist

// XUBC7/XBC7 decoder source code
#include "basisu_xbc7_decoder.inl"

// Plain BC1/3/4/5 block unpackers (basist::bcu) and the DDS reader/transcoder (basist::dds_transcoder).
#include "basisu_dds_transcoder.inl"