/*
 * Copyright 2018 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#pragma warning( disable : 6011 ) // dereferencing NULL pointer (from malloc)
#endif

#include "skcms.h"
#include "src/LinearAlgebra.h"
#include "src/Macros.h"
#include "src/PortableMath.h"
#include "test_only.h"
#include "src/TransferFunction.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#if defined(_MSC_VER)
    #define DEBUGBREAK __debugbreak
#elif defined(__clang__)
    #define DEBUGBREAK __builtin_debugtrap
#else
    #define DEBUGBREAK __builtin_trap
#endif

#define expect(cond)                                                                  \
    do {                                                                              \
        if (!(cond)) {                                                                \
            fprintf(stderr, "expect(" #cond ") failed at %s:%d\n",__FILE__,__LINE__); \
            fflush(stderr);   /* stderr is buffered on Windows. */                    \
            DEBUGBREAK();                                                             \
        }                                                                             \
    } while(false)

static void test_ICCProfile() {
    // Nothing works yet.  :)
    skcms_ICCProfile profile;

    const uint8_t buf[] = { 0x42 };
    expect(!skcms_Parse(buf, sizeof(buf), &profile));
}

static void test_FormatConversions() {
    // If we use a single skcms_ICCProfile, we should be able to use skcms_Transform()
    // to do skcms_PixelFormat conversions.
    skcms_ICCProfile profile;

    // We can interpret src as 85 RGB_888 pixels or 64 RGB_8888 pixels.
    uint8_t src[256],
            dst[85*4];
    for (int i = 0; i < 256; i++) {
        src[i] = (uint8_t)i;
    }

    // This should basically be a really complicated memcpy().
    expect(skcms_Transform(src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           64));
    for (int i = 0; i < 256; i++) {
        expect(dst[i] == i);
    }

    // We can do RGBA -> BGRA swaps two ways:
    expect(skcms_Transform(src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_BGRA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           64));
    for (int i = 0; i < 64; i++) {
        expect(dst[4*i+0] == 4*i+2);
        expect(dst[4*i+1] == 4*i+1);
        expect(dst[4*i+2] == 4*i+0);
        expect(dst[4*i+3] == 4*i+3);
    }
    expect(skcms_Transform(src, skcms_PixelFormat_BGRA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           64));
    for (int i = 0; i < 64; i++) {
        expect(dst[4*i+0] == 4*i+2);
        expect(dst[4*i+1] == 4*i+1);
        expect(dst[4*i+2] == 4*i+0);
        expect(dst[4*i+3] == 4*i+3);
    }

    // Let's convert RGB_888 to RGBA_8888...
    expect(skcms_Transform(src, skcms_PixelFormat_RGB_888  , skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           85));
    for (int i = 0; i < 85; i++) {
        expect(dst[4*i+0] == 3*i+0);
        expect(dst[4*i+1] == 3*i+1);
        expect(dst[4*i+2] == 3*i+2);
        expect(dst[4*i+3] ==   255);
    }
    // ... and now all the variants of R-B swaps.
    expect(skcms_Transform(src, skcms_PixelFormat_BGR_888  , skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_BGRA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           85));
    for (int i = 0; i < 85; i++) {
        expect(dst[4*i+0] == 3*i+0);
        expect(dst[4*i+1] == 3*i+1);
        expect(dst[4*i+2] == 3*i+2);
        expect(dst[4*i+3] ==   255);
    }
    expect(skcms_Transform(src, skcms_PixelFormat_BGR_888  , skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           85));
    for (int i = 0; i < 85; i++) {
        expect(dst[4*i+0] == 3*i+2);
        expect(dst[4*i+1] == 3*i+1);
        expect(dst[4*i+2] == 3*i+0);
        expect(dst[4*i+3] ==   255);
    }
    expect(skcms_Transform(src, skcms_PixelFormat_RGB_888  , skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_BGRA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           85));
    for (int i = 0; i < 85; i++) {
        expect(dst[4*i+0] == 3*i+2);
        expect(dst[4*i+1] == 3*i+1);
        expect(dst[4*i+2] == 3*i+0);
        expect(dst[4*i+3] ==   255);
    }

    // Let's test in-place transforms.
    // RGBA_8888 and RGB_888 aren't the same size, so we shouldn't allow this call.
    expect(!skcms_Transform(src, skcms_PixelFormat_RGB_888  , skcms_AlphaFormat_Unpremul, &profile,
                            src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                            85));

    // These two should work fine.
    expect(skcms_Transform(src, skcms_PixelFormat_BGRA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           64));
    for (int i = 0; i < 64; i++) {
        expect(src[4*i+0] == 4*i+2);
        expect(src[4*i+1] == 4*i+1);
        expect(src[4*i+2] == 4*i+0);
        expect(src[4*i+3] == 4*i+3);
    }
    expect(skcms_Transform(src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           src, skcms_PixelFormat_BGRA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           64));
    for (int i = 0; i < 64; i++) {
        expect(src[4*i+0] == 4*i+0);
        expect(src[4*i+1] == 4*i+1);
        expect(src[4*i+2] == 4*i+2);
        expect(src[4*i+3] == 4*i+3);
    }

    uint32_t _8888[3] = { 0x03020100, 0x07060504, 0x0b0a0908 };
    uint8_t _888[9];
    expect(skcms_Transform(_8888, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           _888 , skcms_PixelFormat_RGB_888  , skcms_AlphaFormat_Unpremul, &profile,
                           3));
    expect(_888[0] == 0 && _888[1] == 1 && _888[2] ==  2);
    expect(_888[3] == 4 && _888[4] == 5 && _888[5] ==  6);
    expect(_888[6] == 8 && _888[7] == 9 && _888[8] == 10);
}

static void test_FormatConversions_565() {
    // If we use a single skcms_ICCProfile, we should be able to use skcms_Transform()
    // to do skcms_PixelFormat conversions.
    skcms_ICCProfile profile;

    // This should hit all the unique values of each lane of 565.
    uint16_t src[64];
    for (int i = 0; i < 64; i++) {
        src[i] = (uint16_t)( (i/2) <<  0 )
               | (uint16_t)( (i/1) <<  5 )
               | (uint16_t)( (i/2) << 11 );
    }
    expect(src[ 0] == 0x0000);
    expect(src[31] == 0x7bef);
    expect(src[63] == 0xffff);

    uint32_t dst[64];
    expect(skcms_Transform(src, skcms_PixelFormat_RGB_565  , skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           64));
    // We'll just spot check these results a bit.
    for (int i = 0; i < 64; i++) {
        expect((dst[i] >> 24) == 255);  // All opaque.
    }
    expect(dst[ 0] == 0xff000000);  // 0 -> 0
    expect(dst[20] == 0xff525152);  // (10/31) ≈ (82/255) and (20/63) ≈ (81/255)
    expect(dst[62] == 0xfffffbff);  // (31/31) == (255/255) and (62/63) ≈ (251/255)
    expect(dst[63] == 0xffffffff);  // 1 -> 1

    // Let's convert back the other way.
    uint16_t back[64];
    expect(skcms_Transform(dst , skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           back, skcms_PixelFormat_RGB_565  , skcms_AlphaFormat_Unpremul, &profile,
                           64));
    for (int i = 0; i < 64; i++) {
        expect(src[i] == back[i]);
    }
}

static void test_FormatConversions_16161616() {
    skcms_ICCProfile profile;

    // We want to hit each 16-bit value, 4 per each of 16384 pixels.
    uint64_t* src = malloc(8 * 16384);
    for (int i = 0; i < 16384; i++) {
        src[i] = (uint64_t)(4*i + 0) <<  0
               | (uint64_t)(4*i + 1) << 16
               | (uint64_t)(4*i + 2) << 32
               | (uint64_t)(4*i + 3) << 48;
    }
    expect(src[    0] == 0x0003000200010000);
    expect(src[ 8127] == 0x7eff7efe7efd7efc);  // This should demonstrate interesting rounding.
    expect(src[16383] == 0xfffffffefffdfffc);

    uint32_t* dst = malloc(4 * 16384);
    expect(skcms_Transform(src, skcms_PixelFormat_RGBA_16161616, skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_RGBA_8888    , skcms_AlphaFormat_Unpremul, &profile,
                           16384));

    // skcms_Transform() will treat src as holding big-endian 16-bit values,
    // so the low lanes are actually the most significant byte, and the high least.

    expect(dst[    0] == 0x03020100);
    expect(dst[ 8127] == 0xfefefdfc);  // 0x7eff rounds down to 0xfe, 0x7efe rounds up to 0xfe.
    expect(dst[16383] == 0xfffefdfc);

    // We've lost precision when transforming to 8-bit, so these won't quite round-trip.
    // Instead we should see the 8-bit dst value byte-doubled, as 65535/255 = 257 = 0x0101.
    uint64_t* back = malloc(8 * 16384);
    expect(skcms_Transform(dst , skcms_PixelFormat_RGBA_8888    , skcms_AlphaFormat_Unpremul, &profile,
                           back, skcms_PixelFormat_RGBA_16161616, skcms_AlphaFormat_Unpremul, &profile,
                           16384));
    for (int i = 0; i < 16384; i++) {
        expect( ((back[i] >>  0) & 0xffff) == ((dst[i] >>  0) & 0xff) * 0x0101);
        expect( ((back[i] >> 16) & 0xffff) == ((dst[i] >>  8) & 0xff) * 0x0101);
        expect( ((back[i] >> 32) & 0xffff) == ((dst[i] >> 16) & 0xff) * 0x0101);
        expect( ((back[i] >> 48) & 0xffff) == ((dst[i] >> 24) & 0xff) * 0x0101);
    }

    free(src);
    free(dst);
    free(back);
}

static void test_FormatConversions_161616() {
    skcms_ICCProfile profile;

    // We'll test the same cases as the _16161616() test, as if they were 4 RGB pixels.
    uint16_t src[] = { 0x0000, 0x0001, 0x0002,
                       0x0003, 0x7efc, 0x7efd,
                       0x7efe, 0x7eff, 0xfffc,
                       0xfffd, 0xfffe, 0xffff };
    uint32_t dst[4];
    expect(skcms_Transform(src, skcms_PixelFormat_RGB_161616, skcms_AlphaFormat_Unpremul, &profile,
                           dst, skcms_PixelFormat_RGBA_8888 , skcms_AlphaFormat_Unpremul, &profile,
                           4));

    expect(dst[0] == 0xff020100);
    expect(dst[1] == 0xfffdfc03);
    expect(dst[2] == 0xfffcfefe);
    expect(dst[3] == 0xfffffefd);

    // We've lost precision when transforming to 8-bit, so these won't quite round-trip.
    // Instead we should see the most signficant (low) byte doubled, as 65535/255 = 257 = 0x0101.
    uint16_t back[12];
    expect(skcms_Transform(dst , skcms_PixelFormat_RGBA_8888 , skcms_AlphaFormat_Unpremul, &profile,
                           back, skcms_PixelFormat_RGB_161616, skcms_AlphaFormat_Unpremul, &profile,
                           4));
    for (int i = 0; i < 12; i++) {
        expect(back[0] == (src[0] & 0xff) * 0x0101);
    }
}

static void test_FormatConversions_101010() {
    skcms_ICCProfile profile;

    uint32_t src = (uint32_t)1023 <<  0    // 1.0.
                 | (uint32_t) 511 << 10    // About 1/2.
                 | (uint32_t)   4 << 20    // Smallest 10-bit channel that's non-zero in 8-bit.
                 | (uint32_t)   1 << 30;   // 1/3, smallest non-zero alpha.
    uint32_t dst;
    expect(skcms_Transform(&src, skcms_PixelFormat_RGBA_1010102, skcms_AlphaFormat_Unpremul, &profile,
                           &dst, skcms_PixelFormat_RGBA_8888   , skcms_AlphaFormat_Unpremul, &profile,
                           1));
    expect(dst == 0x55017fff);

    // Same as above, but we'll ignore the 1/3 alpha and fill in 1.0.
    expect(skcms_Transform(&src, skcms_PixelFormat_RGBA_1010102, skcms_AlphaFormat_Opaque  , &profile,
                           &dst, skcms_PixelFormat_RGBA_8888   , skcms_AlphaFormat_Unpremul, &profile,
                           1));
    expect(dst == 0xff017fff);

    // Converting 101010x <-> 1010102 will force opaque in either direction.
    expect(skcms_Transform(&src, skcms_PixelFormat_RGBA_1010102, skcms_AlphaFormat_Unpremul, &profile,
                           &dst, skcms_PixelFormat_RGBA_1010102, skcms_AlphaFormat_Opaque  , &profile,
                           1));
    expect(dst == ( (uint32_t)1023 <<  0
                  | (uint32_t) 511 << 10
                  | (uint32_t)   4 << 20
                  | (uint32_t)   3 << 30));
    expect(skcms_Transform(&src, skcms_PixelFormat_RGBA_1010102, skcms_AlphaFormat_Opaque  , &profile,
                           &dst, skcms_PixelFormat_RGBA_1010102, skcms_AlphaFormat_Unpremul, &profile,
                           1));
    expect(dst == ( (uint32_t)1023 <<  0
                  | (uint32_t) 511 << 10
                  | (uint32_t)   4 << 20
                  | (uint32_t)   3 << 30));
}

static void test_FormatConversions_half() {
    skcms_ICCProfile profile;

    uint16_t src[] = {
        0x3c00,  // 1.0
        0x3800,  // 0.5
        0x1805,  // Should round up to 0x01
        0x1804,  // Should round down to 0x00
        0x4000,  // 2.0
        0x03ff,  // A denorm, may be flushed to zero.
        0x83ff,  // A negative denorm, may be flushed to zero.
        0xbc00,  // -1.0
    };

    uint32_t dst[2];
    expect(skcms_Transform(&src, skcms_PixelFormat_RGBA_hhhh, skcms_AlphaFormat_Unpremul, &profile,
                           &dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           2));
    expect(dst[0] == 0x000180ff);
    expect(dst[1] == 0x000000ff);  // Notice we've clamped 2.0 to 0xff and -1.0 to 0x00.

    expect(skcms_Transform(&src, skcms_PixelFormat_RGB_hhh  , skcms_AlphaFormat_Unpremul, &profile,
                           &dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           2));
    expect(dst[0] == 0xff0180ff);
    expect(dst[1] == 0xff00ff00);  // Remember, this corresponds to src[3-5].

    float fdst[8];
    expect(skcms_Transform( &src, skcms_PixelFormat_RGBA_hhhh, skcms_AlphaFormat_Unpremul, &profile,
                           &fdst, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &profile,
                           2));
    expect(fdst[0] ==  1.0f);
    expect(fdst[1] ==  0.5f);
    expect(fdst[2] > 1/510.0f);
    expect(fdst[3] < 1/510.0f);
    expect(fdst[4] ==  2.0f);
    expect(fdst[5] == +0.00006097555f || fdst[5] == 0.0f);  // may have been flushed to zero
    expect(fdst[6] == -0.00006097555f || fdst[6] == 0.0f);
    expect(fdst[7] == -1.0f);

    // Now convert back, first to RGBA halfs, then RGB halfs.
    uint16_t back[8];
    expect(skcms_Transform(&fdst, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &profile,
                           &back, skcms_PixelFormat_RGBA_hhhh, skcms_AlphaFormat_Unpremul, &profile,
                           2));
    expect(back[0] == src[0]);
    expect(back[1] == src[1]);
    expect(back[2] == src[2]);
    expect(back[3] == src[3]);
    expect(back[4] == src[4]);
    expect(back[5] == src[5] || back[5] == 0x0000);
    expect(back[6] == src[6] || back[6] == 0x0000);
    expect(back[7] == src[7]);

    expect(skcms_Transform(&fdst, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &profile,
                           &back, skcms_PixelFormat_RGB_hhh  , skcms_AlphaFormat_Unpremul, &profile,
                           2));
    expect(back[0] == src[0]);
    expect(back[1] == src[1]);
    expect(back[2] == src[2]);
    expect(back[3] == src[4]);
    expect(back[4] == src[5] || back[4] == 0x0000);
    expect(back[5] == src[6] || back[5] == 0x0000);
}

static void test_FormatConversions_float() {
    skcms_ICCProfile profile;

    float src[] = { 1.0f, 0.5f, 1/255.0f, 1/512.0f };

    uint32_t dst;
    expect(skcms_Transform(&src, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &profile,
                           &dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           1));
    expect(dst == 0x000180ff);

    // Same as above, but we'll ignore the 1/512 alpha and fill in 1.0.
    expect(skcms_Transform(&src, skcms_PixelFormat_RGB_fff  , skcms_AlphaFormat_Unpremul, &profile,
                           &dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                           1));
    expect(dst == 0xff0180ff);

    // Let's make sure each byte converts to the float we expect.
    uint32_t bytes[64];
    float   fdst[4*64];
    for (int i = 0; i < 64; i++) {
        bytes[i] = 0x03020100 + 0x04040404 * (uint32_t)i;
    }
    expect(skcms_Transform(&bytes, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &profile,
                            &fdst, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &profile,
                           64));
    for (int i = 0; i < 256; i++) {
        expect(fdst[i] == i*(1/255.0f));
    }

    float ffff[16] = { 0,1,2,3, 4,5,6,7, 8,9,10,11, 12,13,14,15 };
    float  fff[12] = { 0,0,0, 0,0,0, 0,0,0, 0,0,0};
    expect(skcms_Transform(ffff, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &profile,
                           fff , skcms_PixelFormat_RGB_fff  , skcms_AlphaFormat_Unpremul, &profile,
                           1));
    expect(fff[0] == 0); expect(fff[1] == 1); expect(fff[2] == 2);

    expect(skcms_Transform(ffff, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &profile,
                           fff , skcms_PixelFormat_RGB_fff  , skcms_AlphaFormat_Unpremul, &profile,
                           4));
    expect(fff[0] ==  0); expect(fff[ 1] ==  1); expect(fff[ 2] ==  2);
    expect(fff[3] ==  4); expect(fff[ 4] ==  5); expect(fff[ 5] ==  6);
    expect(fff[6] ==  8); expect(fff[ 7] ==  9); expect(fff[ 8] == 10);
    expect(fff[9] == 12); expect(fff[10] == 13); expect(fff[11] == 14);
}

static const skcms_TransferFunction srgb_transfer_fn =
    { 2.4f, 1 / 1.055f, 0.055f / 1.055f, 1 / 12.92f, 0.04045f, 0.0f, 0.0f };
static const skcms_TransferFunction kodak_transfer_fn =
    { 2.42f, 0.939f, 0.0595f, 0.0691f, 0.0392f, 0.00305f, 0.00392f };
// static const skcms_TransferFunction gamma_1_8_transfer_fn =
//     { 1.8f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
static const skcms_TransferFunction gamma_2_2_transfer_fn =
    { 2.2f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
static const skcms_TransferFunction gamma_2_4_transfer_fn =
    { 2.4f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
static const skcms_TransferFunction gamma_2_8_transfer_fn =
    { 2.8f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
static const skcms_TransferFunction bt_709_transfer_fn =
    { 1 / 0.45f, 1 / 1.099f, 0.099f / 1.099f, 1 / 4.5f, 0.081f, 0.0f, 0.0f };
static const skcms_TransferFunction smpte_240m_transfer_fn =
    { 1 / 0.45f, 1 / 1.1115f, 0.1115f / 1.1115f, 0.25f, 0.0913f, 0.0f, 0.0f };
// These are two different ways to represent the linear (identity) transfer function
static const skcms_TransferFunction gamma_1_transfer_fn =
    { 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
static const skcms_TransferFunction linear_transfer_fn =
    { 0.0f, 1.0f, 0.0f, 1.0f, 2.0f, 0.0f, 0.0f };
static const skcms_TransferFunction dot_gain_transfer_fn =
    { 1.737f, 1.0f, 0.0f, 0.0626f, 0.02353f, 0.0f, 0.0f };

typedef struct {
    const char*                   filename;
    const skcms_TransferFunction* expect_approx_tf;
} ProfileTestCase;

static const ProfileTestCase profile_test_cases[] = {
    // iccMAX profiles that we can't parse at all
    { "profiles/color.org/sRGB_D65_colorimetric.icc", NULL },
    { "profiles/color.org/sRGB_D65_MAT.icc",          NULL },
    { "profiles/color.org/sRGB_ISO22028.icc",         NULL },

    // V2 or V4 profiles that only include A2B/B2A tags (no TRC or XYZ)
    { "profiles/color.org/sRGB_ICC_v4_Appearance.icc", NULL },
    { "profiles/color.org/sRGB_v4_ICC_preference.icc", NULL },
    { "profiles/color.org/Upper_Left.icc",             NULL },
    { "profiles/color.org/Upper_Right.icc",            NULL },
    { "profiles/misc/Apple_Wide_Color.icc",            NULL },
    { "profiles/misc/Coated_FOGRA39_CMYK.icc",         NULL },
    { "profiles/misc/ColorLogic_ISO_Coated_CMYK.icc",  NULL }, // Has kTRC.
    { "profiles/misc/Japan_Color_2001_Coated.icc",     NULL },
    { "profiles/misc/Lexmark_X110.icc",                NULL },
    { "profiles/misc/MartiMaria_browsertest_A2B.icc",  NULL },
    { "profiles/misc/PrintOpen_ISO_Coated_CMYK.icc",   NULL }, // Has kTRC.
    { "profiles/misc/sRGB_ICC_v4_beta.icc",            NULL },
    { "profiles/misc/SWOP_Coated_20_GCR_CMYK.icc",     NULL },
    { "profiles/misc/US_Web_Coated_SWOP_CMYK.icc",     NULL },
    { "profiles/misc/XRite_GRACol7_340_CMYK.icc",      NULL },

    // V2 monochrome output profiles that include kTRC but no A2B
    { "profiles/misc/Dot_Gain_20_Grayscale.icc", &dot_gain_transfer_fn }, // kTRC table
    { "profiles/misc/Gray_Gamma_22.icc",         NULL }, // kTRC gamma

    // V4 profiles with parametric TRC curves and XYZ
    { "profiles/mobile/Display_P3_parametric.icc", NULL },
    { "profiles/mobile/sRGB_parametric.icc",       NULL },
    { "profiles/mobile/iPhone7p.icc",              NULL },
    { "profiles/misc/sRGB_lcms.icc",               NULL },

    // V4 profiles with LUT TRC curves and XYZ
    { "profiles/mobile/Display_P3_LUT.icc", &srgb_transfer_fn },
    { "profiles/mobile/sRGB_LUT.icc",       &srgb_transfer_fn },

    // V2 profiles with gamma TRC and XYZ
    { "profiles/color.org/Lower_Left.icc",      NULL },
    { "profiles/color.org/Lower_Right.icc",     NULL },
    { "profiles/misc/AdobeRGB.icc",             NULL },
    { "profiles/misc/Color_Spin_Gamma_18.icc",  NULL },
    { "profiles/misc/Generic_RGB_Gamma_18.icc", NULL },

    // V2 profiles with LUT TRC and XYZ
    { "profiles/color.org/sRGB2014.icc",     &srgb_transfer_fn },
    { "profiles/sRGB_Facebook.icc",          &srgb_transfer_fn },
    { "profiles/misc/Apple_Color_LCD.icc",   &srgb_transfer_fn },
    { "profiles/misc/HD_709.icc",            &srgb_transfer_fn },
    { "profiles/misc/sRGB_black_scaled.icc", &srgb_transfer_fn },
    { "profiles/misc/sRGB_HP.icc",           &srgb_transfer_fn },
    { "profiles/misc/sRGB_HP_2.icc",         &srgb_transfer_fn },

    // Calibrated monitor profile with non-monotonic TRC tables. We approximate, but badly.
    { "profiles/misc/DisplayCal_ASUS_NonMonotonic.icc", NULL },

    // Hard test profile. Non-invertible XYZ, three separate tables that fail to approximate
    { "profiles/misc/MartiMaria_browsertest_HARD.icc", NULL },

    // Camera profile with three separate tables that fail to approximate
    { "profiles/misc/Phase_One_P25.icc", NULL },

    // Profile claims to be sRGB, but seems quite different
    { "profiles/misc/Kodak_sRGB.icc", &kodak_transfer_fn },

    // Bad profiles found inn the wild
    { "profiles/misc/ColorGATE_Sihl_PhotoPaper.icc", NULL }, // Broken tag table, and A2B0 fails to parse

    // fuzzer generated profiles that found parsing bugs

    // Bad tag table data - these should not parse
    { "profiles/fuzz/last_tag_too_small.icc",  NULL }, // skia:7592
    { "profiles/fuzz/named_tag_too_small.icc", NULL }, // skia:7592

    // Bad tag data - these should not parse
    { "profiles/fuzz/curv_size_overflow.icc",          NULL }, // skia:7593
    { "profiles/fuzz/truncated_curv_tag.icc",          NULL }, // oss-fuzz:6103
    { "profiles/fuzz/zero_a.icc",                      NULL }, // oss-fuzz:????
    { "profiles/fuzz/a2b_too_many_input_channels.icc", NULL }, // oss-fuzz:6521
};

static void check_roundtrip_transfer_functions(const skcms_TransferFunction* fwd,
                                               const skcms_TransferFunction* rev,
                                               float tol) {
    for (int i = 0; i < 256; ++i) {
        float t = i / 255.0f;
        float x = skcms_TransferFunction_eval(rev, skcms_TransferFunction_eval(fwd, t));
        expect((int)(x * 255.0f + 0.5f) == i);
        expect(fabsf_(x - t) < tol);
    }
}

static bool has_single_approx_trc(const skcms_ICCProfile* profile, skcms_TransferFunction* approx,
                                  float* max_error) {
    if (!profile->has_trc) {
        return false;
    }

    skcms_TransferFunction tf[3];
    for (int i = 0; i < 3; ++i) {
        if (!skcms_ApproximateCurve(&profile->trc[i], &tf[i], max_error)) {
            return false;
        }
    }

    if (0 != memcmp(&tf[0], &tf[1], sizeof(tf[0])) || 0 != memcmp(&tf[0], &tf[2], sizeof(tf[0]))) {
        return false;
    }

    *approx = tf[0];
    return true;
}

static void test_Parse(bool regen) {
    for (int i = 0; i < ARRAY_COUNT(profile_test_cases); ++i) {
        const ProfileTestCase* test = profile_test_cases + i;

        void* buf = NULL;
        size_t len = 0;
        expect(load_file(test->filename, &buf, &len));
        skcms_ICCProfile profile;
        bool parsed = skcms_Parse(buf, len, &profile);

        FILE* dump = tmpfile();
        expect(dump);

        if (parsed) {
            dump_profile(&profile, dump, true);
        } else {
            fprintf(dump, "Unable to parse ICC profile\n");
        }

        void* dump_buf = NULL;
        size_t dump_len = 0;
        expect(load_file_fp(dump, &dump_buf, &dump_len));
        fclose(dump);

        char ref_filename[256];
        if (snprintf(ref_filename, sizeof(ref_filename), "%s.txt", test->filename) < 0) {
            expect(false);
        }

        if (regen) {
            // Just write out new test data if in regen mode
            expect(write_file(ref_filename, dump_buf, dump_len));
        } else {
            // Read in existing test data
            void* ref_buf = NULL;
            size_t ref_len = 0;
            expect(load_file(ref_filename, &ref_buf, &ref_len));

            if (dump_len != ref_len || memcmp(dump_buf, ref_buf, dump_len) != 0) {
                // Write out the new data on a mismatch
                fprintf(stderr, "Parse mismatch for %s:\n", test->filename);
                fwrite(dump_buf, 1, dump_len, stderr);
                fprintf(stderr, "\n");
                expect(false);
            }
            free(ref_buf);
        }

        skcms_TransferFunction approx_tf;
        float max_error;
        bool approx_tf_result = has_single_approx_trc(&profile, &approx_tf, &max_error);
        expect(approx_tf_result == !!test->expect_approx_tf);
        if (approx_tf_result) {
            // For this check, run every byte value through the forward version of one TF, and
            // the inverse of the other, and make sure it round-trips (using both combinations).
            skcms_TransferFunction approx_inverse_tf;
            skcms_TransferFunction expect_inverse_tf;
            expect(skcms_TransferFunction_invert(&approx_tf, &approx_inverse_tf));
            expect(skcms_TransferFunction_invert(test->expect_approx_tf, &expect_inverse_tf));

            // This function verifies that all bytes round-trip perfectly, but also takes a
            // tolerance to further limit the error after round-trip. We can currently get this
            // within ~30% of a byte (0.0011).
            check_roundtrip_transfer_functions(&approx_tf, &expect_inverse_tf, 0.02f);
            check_roundtrip_transfer_functions(test->expect_approx_tf, &approx_inverse_tf, 0.02f);
        }

        free(buf);
        free(dump_buf);
    }
}

typedef struct {
    const skcms_TransferFunction* tf;
    int n;
} TransferFunctionAndSampleCount;

static float table_func_tf_eval(int i, const void* ctx) {
    const TransferFunctionAndSampleCount* tfasc = (const TransferFunctionAndSampleCount*)ctx;
    float xi = i / (tfasc->n - 1.0f);
    return skcms_TransferFunction_eval(tfasc->tf, xi);
}

static void test_TransferFunction_approximate() {
    const skcms_TransferFunction* transfer_fns[] = {
//        &gamma_1_8_transfer_fn,
        &gamma_2_2_transfer_fn,
        &gamma_2_4_transfer_fn,
        &gamma_2_8_transfer_fn,
        &srgb_transfer_fn,
        &kodak_transfer_fn,
        &smpte_240m_transfer_fn,
        &bt_709_transfer_fn,
        &gamma_1_transfer_fn,
        &linear_transfer_fn,
    };
    const int num_transfer_fns = ARRAY_COUNT(transfer_fns);

    int table_sizes[] = { 512, 256, 128, 64, 16, 11, 8, 7, 6, 5 };
    const int num_table_sizes = ARRAY_COUNT(table_sizes);
    TransferFunctionAndSampleCount tfasc;

    for (int ts = 0; ts < num_table_sizes; ++ts) {
        for (int tf = 0; tf < num_transfer_fns; ++tf) {
            skcms_TransferFunction fn_approx;
            float max_error;
            tfasc.tf = transfer_fns[tf];
            tfasc.n = table_sizes[ts];
            expect(skcms_TransferFunction_approximate(table_func_tf_eval, &tfasc, table_sizes[ts],
                                                      &fn_approx, &max_error));
            expect(max_error < 3.f / 256.f);
        }
    }
}

static float table_func_float(int i, const void* ctx) {
    return ((const float*)ctx)[i];
}

static void test_TransferFunction_approximate_clamped() {
    // These data represent a transfer function that is clamped at the high
    // end of its domain. It comes from the color profile attached to
    // https://crbug.com/750459
    float t[256] = {
        0.000000f, 0.000305f, 0.000610f, 0.000916f, 0.001221f, 0.001511f,
        0.001816f, 0.002121f, 0.002426f, 0.002731f, 0.003037f, 0.003601f,
        0.003937f, 0.004303f, 0.004685f, 0.005081f, 0.005509f, 0.005951f,
        0.006409f, 0.006882f, 0.007385f, 0.007904f, 0.008438f, 0.009003f,
        0.009583f, 0.010193f, 0.010819f, 0.011460f, 0.012131f, 0.012818f,
        0.013535f, 0.014267f, 0.015030f, 0.015808f, 0.016617f, 0.017456f,
        0.018296f, 0.019181f, 0.020081f, 0.021012f, 0.021958f, 0.022934f,
        0.023926f, 0.024949f, 0.026001f, 0.027070f, 0.028168f, 0.029297f,
        0.030442f, 0.031617f, 0.032822f, 0.034058f, 0.035309f, 0.036591f,
        0.037903f, 0.039231f, 0.040604f, 0.041993f, 0.043412f, 0.044846f,
        0.046326f, 0.047822f, 0.049348f, 0.050904f, 0.052491f, 0.054108f,
        0.055756f, 0.057420f, 0.059113f, 0.060853f, 0.062608f, 0.064393f,
        0.066209f, 0.068055f, 0.069932f, 0.071839f, 0.073762f, 0.075731f,
        0.077729f, 0.079759f, 0.081804f, 0.083894f, 0.086015f, 0.088167f,
        0.090333f, 0.092546f, 0.094789f, 0.097063f, 0.099367f, 0.101701f,
        0.104067f, 0.106477f, 0.108904f, 0.111360f, 0.113863f, 0.116381f,
        0.118944f, 0.121538f, 0.124163f, 0.126818f, 0.129519f, 0.132235f,
        0.134997f, 0.137789f, 0.140612f, 0.143465f, 0.146365f, 0.149279f,
        0.152239f, 0.155230f, 0.158267f, 0.161318f, 0.164416f, 0.167544f,
        0.170718f, 0.173907f, 0.177142f, 0.180407f, 0.183719f, 0.187045f,
        0.190433f, 0.193835f, 0.197284f, 0.200763f, 0.204273f, 0.207813f,
        0.211398f, 0.215030f, 0.218692f, 0.222385f, 0.226108f, 0.229877f,
        0.233677f, 0.237522f, 0.241382f, 0.245304f, 0.249256f, 0.253239f,
        0.257252f, 0.261311f, 0.265415f, 0.269551f, 0.273716f, 0.277928f,
        0.282170f, 0.286458f, 0.290776f, 0.295140f, 0.299535f, 0.303975f,
        0.308446f, 0.312947f, 0.317494f, 0.322087f, 0.326711f, 0.331380f,
        0.336080f, 0.340826f, 0.345602f, 0.350423f, 0.355291f, 0.360174f,
        0.365118f, 0.370092f, 0.375113f, 0.380163f, 0.385260f, 0.390387f,
        0.395560f, 0.400778f, 0.406027f, 0.411322f, 0.416663f, 0.422034f,
        0.427451f, 0.432898f, 0.438392f, 0.443931f, 0.449500f, 0.455116f,
        0.460777f, 0.466468f, 0.472221f, 0.477989f, 0.483818f, 0.489677f,
        0.495583f, 0.501518f, 0.507500f, 0.513527f, 0.519600f, 0.525719f,
        0.531868f, 0.538064f, 0.544289f, 0.550576f, 0.556893f, 0.563256f,
        0.569650f, 0.576104f, 0.582589f, 0.589120f, 0.595697f, 0.602304f,
        0.608972f, 0.615671f, 0.622415f, 0.629206f, 0.636027f, 0.642908f,
        0.649821f, 0.656779f, 0.663783f, 0.670832f, 0.677913f, 0.685054f,
        0.692226f, 0.699443f, 0.706706f, 0.714015f, 0.721370f, 0.728771f,
        0.736202f, 0.743694f, 0.751217f, 0.758785f, 0.766400f, 0.774060f,
        0.781765f, 0.789517f, 0.797314f, 0.805158f, 0.813031f, 0.820966f,
        0.828946f, 0.836957f, 0.845029f, 0.853132f, 0.861280f, 0.869490f,
        0.877729f, 0.886015f, 0.894362f, 0.902739f, 0.911162f, 0.919631f,
        0.928161f, 0.936721f, 0.945327f, 0.953994f, 0.962692f, 0.971435f,
        0.980240f, 0.989075f, 0.997955f, 1.000000f,
    };

    skcms_TransferFunction fn_approx;
    float max_error;
    expect(skcms_TransferFunction_approximate(table_func_float, t, 256, &fn_approx, &max_error));

    // The approximation isn't very good.
    expect(max_error < 1 / 128.0f);
}

static void expect_eq_Matrix3x3(skcms_Matrix3x3 a, skcms_Matrix3x3 b) {
    for (int r = 0; r < 3; r++)
    for (int c = 0; c < 3; c++) {
        expect(a.vals[r][c] == b.vals[r][c]);
    }
}

static void test_Matrix3x3_invert() {
    skcms_Matrix3x3 inv;

    skcms_Matrix3x3 I = {{
        { 1.0f, 0.0f, 0.0f },
        { 0.0f, 1.0f, 0.0f },
        { 0.0f, 0.0f, 1.0f },
    }};
    inv = (skcms_Matrix3x3){{ {0,0,0}, {0,0,0}, {0,0,0} }};
    expect(skcms_Matrix3x3_invert(&I, &inv));
    expect_eq_Matrix3x3(inv, I);

    skcms_Matrix3x3 T = {{
        { 1.0f, 0.0f, 3.0f },
        { 0.0f, 1.0f, 4.0f },
        { 0.0f, 0.0f, 1.0f },
    }};
    inv = (skcms_Matrix3x3){{ {0,0,0}, {0,0,0}, {0,0,0} }};
    expect(skcms_Matrix3x3_invert(&T, &inv));
    expect_eq_Matrix3x3(inv, (skcms_Matrix3x3){{
        { 1.0f, 0.0f, -3.0f },
        { 0.0f, 1.0f, -4.0f },
        { 0.0f, 0.0f,  1.0f },
    }});

    skcms_Matrix3x3 S = {{
        { 2.0f, 0.0f, 0.0f },
        { 0.0f, 4.0f, 0.0f },
        { 0.0f, 0.0f, 8.0f },
    }};
    inv = (skcms_Matrix3x3){{ {0,0,0}, {0,0,0}, {0,0,0} }};
    expect(skcms_Matrix3x3_invert(&S, &inv));
    expect_eq_Matrix3x3(inv, (skcms_Matrix3x3){{
        { 0.500f, 0.000f,  0.000f },
        { 0.000f, 0.250f,  0.000f },
        { 0.000f, 0.000f,  0.125f },
    }});
}

static void test_SimpleRoundTrip() {
    // We'll test that parametric sRGB roundtrips with itself, bytes -> bytes.
    void*  srgb_ptr;
    size_t srgb_len;
    expect(load_file("profiles/mobile/sRGB_parametric.icc", &srgb_ptr, &srgb_len));

    skcms_ICCProfile srgbA, srgbB;
    expect(skcms_Parse(srgb_ptr, srgb_len, &srgbA));
    expect(skcms_Parse(srgb_ptr, srgb_len, &srgbB));

    uint8_t src[256],
            dst[256];
    for (int i = 0; i < 256; i++) {
        src[i] = (uint8_t)i;
    }

    expect(skcms_Transform(src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &srgbB,
                           dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, &srgbA,
                           64));
    for (int i = 0; i < 256; i++) {
        expect(dst[i] == (uint8_t)i);
    }

    free(srgb_ptr);
}

// Floats should hold enough precision that we can round trip any two non-degenerate profiles.
static void expect_round_trip_through_floats(const skcms_ICCProfile* A,
                                             const skcms_ICCProfile* B) {
    uint8_t bytes[256];
    float  floats[256];
    for (int i = 0; i < 256; i++) {
        bytes[i] = (uint8_t)i;
    }

    expect(skcms_Transform(bytes , skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, B,
                           floats, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, A,
                           64));
    for (int i = 0; i < 256; i++) {
        bytes[i] = 0;
    }
    expect(skcms_Transform(floats, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, A,
                           bytes , skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul, B,
                           64));

    for (int i = 0; i < 256; i++) {
        expect(bytes[i] == (uint8_t)i);
    }
}

static void test_FloatRoundTrips() {
    void*  srgb_ptr;
    size_t srgb_len;
    expect(load_file("profiles/mobile/sRGB_parametric.icc", &srgb_ptr, &srgb_len));


    void*  dp3_ptr;
    size_t dp3_len;
    expect(load_file("profiles/mobile/Display_P3_parametric.icc", &dp3_ptr, &dp3_len));

    void*  ll_ptr;
    size_t ll_len;
    expect(load_file("profiles/color.org/Lower_Left.icc", &ll_ptr, &ll_len));

    void*  lr_ptr;
    size_t lr_len;
    expect(load_file("profiles/color.org/Lower_Right.icc", &lr_ptr, &lr_len));

    skcms_ICCProfile srgb, dp3, ll, lr;
    expect(skcms_Parse(srgb_ptr, srgb_len, &srgb));
    expect(skcms_Parse( dp3_ptr,  dp3_len, &dp3 ));
    expect(skcms_Parse(  ll_ptr,   ll_len, &ll  ));
    expect(skcms_Parse(  lr_ptr,   lr_len, &lr  ));


    const skcms_ICCProfile* profiles[] = { &srgb, &dp3, &ll, &lr };
    for (int i = 0; i < ARRAY_COUNT(profiles); i++)
    for (int j = 0; j < ARRAY_COUNT(profiles); j++) {
        expect_round_trip_through_floats(profiles[i], profiles[j]);
    }

    free(srgb_ptr);
    free( dp3_ptr);
    free(  ll_ptr);
    free(  lr_ptr);
}

static void test_sRGB_AllBytes() {
    // Test that our transfer function implementation is perfect to at least 8-bit precision.

    void* ptr;
    size_t len;
    skcms_ICCProfile sRGB;
    expect( load_file("profiles/mobile/sRGB_parametric.icc", &ptr, &len) );
    expect( skcms_Parse(ptr, len, &sRGB) );

    skcms_ICCProfile linear_sRGB = sRGB;
    linear_sRGB.trc[0].parametric = (skcms_TransferFunction){ 1,1,0,0,0,0,0 };
    linear_sRGB.trc[1].parametric = (skcms_TransferFunction){ 1,1,0,0,0,0,0 };
    linear_sRGB.trc[2].parametric = (skcms_TransferFunction){ 1,1,0,0,0,0,0 };

    // Enough to hit all distinct bytes when interpreted as RGB 888.
    uint8_t src[258],
            dst[258];
    for (int i = 0; i < 258; i++) {
        src[i] = (uint8_t)(i & 0xFF);  // (We don't really care about bytes 256 and 257.)
    }

    expect( skcms_Transform(src, skcms_PixelFormat_RGB_888, skcms_AlphaFormat_Unpremul, &sRGB,
                            dst, skcms_PixelFormat_RGB_888, skcms_AlphaFormat_Unpremul, &linear_sRGB,
                            258/3) );

    for (int i = 0; i < 256; i++) {
        float linear = skcms_TransferFunction_eval(&sRGB.trc[0].parametric, i * (1/255.0f));
        uint8_t expected = (uint8_t)(linear * 255.0f + 0.5f);

        if (dst[i] != expected) {
            fprintf(stderr, "%d -> %u, want %u\n", i, dst[i], expected);
        }

        expect(dst[i] == expected);
    }

    free(ptr);
}

static void test_TRC_Table16() {
    // We'll convert from FB (table-based sRGB) to sRGB (parametric sRGB).
    skcms_ICCProfile FB, sRGB;

    void  *FB_ptr, *sRGB_ptr;
    size_t FB_len,  sRGB_len;
    expect( load_file("profiles/sRGB_Facebook.icc"         , &  FB_ptr, &  FB_len) );
    expect( load_file("profiles/mobile/sRGB_parametric.icc", &sRGB_ptr, &sRGB_len) );
    expect( skcms_Parse(  FB_ptr,   FB_len, &  FB) );
    expect( skcms_Parse(sRGB_ptr, sRGB_len, &sRGB) );

    // Enough to hit all distinct bytes when interpreted as RGB 888.
    uint8_t src[258],
            dst[258];
    for (int i = 0; i < 258; i++) {
        src[i] = (uint8_t)(i & 0xFF);  // (We don't really care about bytes 256 and 257.)
    }

    expect( skcms_Transform(src, skcms_PixelFormat_RGB_888, skcms_AlphaFormat_Unpremul, &FB,
                            dst, skcms_PixelFormat_RGB_888, skcms_AlphaFormat_Unpremul, &sRGB,
                            258/3) );

    for (int i = 0; i < 256; i++) {
        expect( dst[i] == i );
    }

    free(  FB_ptr);
    free(sRGB_ptr);
}

static void test_Premul() {
    void* ptr;
    size_t len;
    skcms_ICCProfile sRGB;
    expect( load_file("profiles/mobile/sRGB_parametric.icc", &ptr, &len) );
    expect( skcms_Parse(ptr, len, &sRGB) );

    expect (sRGB.has_trc && sRGB.trc[0].table_entries == 0);

    const skcms_TransferFunction* tf = &sRGB.trc[0].parametric;
    skcms_TransferFunction inv;
    expect (skcms_TransferFunction_invert(tf, &inv));

    uint8_t src[256],
            dst[256] = {0};
    for (int i = 0; i < 256; i++) {
        src[i] = (uint8_t)i;
    }

    expect(skcms_Transform(
        src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul       , &sRGB,
        dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_PremulAsEncoded, &sRGB,
        64));
    for (int i = 0; i < 256; i+=4) {
        expect( dst[i+0] == (uint8_t)( src[i+0] * (src[i+3]/255.0f) + 0.5f ) );
        expect( dst[i+1] == (uint8_t)( src[i+1] * (src[i+3]/255.0f) + 0.5f ) );
        expect( dst[i+2] == (uint8_t)( src[i+2] * (src[i+3]/255.0f) + 0.5f ) );
        expect( dst[i+3] == src[i+3] );
    }

    expect(skcms_Transform(
        src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_PremulAsEncoded, &sRGB,
        dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul       , &sRGB,
        64));
    for (int i = 0; i < 256; i+=4) {
        expect( dst[i+0] == (uint8_t)( src[i+0] / (src[i+3]/255.0f) + 0.5f ) );
        expect( dst[i+1] == (uint8_t)( src[i+1] / (src[i+3]/255.0f) + 0.5f ) );
        expect( dst[i+2] == (uint8_t)( src[i+2] / (src[i+3]/255.0f) + 0.5f ) );
        expect( dst[i+3] == src[i+3] );
    }

    expect(skcms_Transform(
        src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul    , &sRGB,
        dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_PremulLinear, &sRGB,
        64));
    for (int i = 0; i < 256; i+=4) {
        for (int k = 0; k < 3; k++) {
            float l = skcms_TransferFunction_eval(tf,       src[i+k]/255.0f);
            float e = skcms_TransferFunction_eval(&inv, l * src[i+3]/255.0f);
            expect( dst[i+k] == (uint8_t)(255.0f*e + 0.5f) );
        }
        expect( dst[i+3] == src[i+3] );
    }

    expect(skcms_Transform(
        src, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_PremulLinear, &sRGB,
        dst, skcms_PixelFormat_RGBA_8888, skcms_AlphaFormat_Unpremul    , &sRGB,
        64));
    for (int i = 0; i < 256; i+=4) {
        for (int k = 0; k < 3; k++) {
            float pm = skcms_TransferFunction_eval(tf,         src[i+k]/255.0f );
            float e  = skcms_TransferFunction_eval(&inv, pm / (src[i+3]/255.0f));
            expect( dst[i+k] == (uint8_t)(255.0f*e + 0.5f) );
        }
        expect( dst[i+3] == src[i+3] );
    }

    free(ptr);
}

static void test_ByteToLinearFloat() {
    uint32_t src[1] = { 0xFFFFFFFF };
    float dst[4];

    void*  srgb_ptr;
    size_t srgb_len;
    expect(load_file("profiles/mobile/sRGB_parametric.icc", &srgb_ptr, &srgb_len));

    skcms_ICCProfile srgb, srgb_linear;
    expect(skcms_Parse(srgb_ptr, srgb_len, &srgb));
    srgb_linear = srgb;
    for (int i = 0; i < 3; ++i) {
        srgb_linear.trc[i].parametric.g = 1.0f;
        srgb_linear.trc[i].parametric.a = 1.0f;
        srgb_linear.trc[i].parametric.b = 0.0f;
        srgb_linear.trc[i].parametric.c = 0.0f;
        srgb_linear.trc[i].parametric.d = 0.0f;
        srgb_linear.trc[i].parametric.e = 0.0f;
        srgb_linear.trc[i].parametric.f = 0.0f;
    }

    skcms_Transform(src, skcms_PixelFormat_BGRA_8888, skcms_AlphaFormat_Unpremul, &srgb,
                    dst, skcms_PixelFormat_RGBA_ffff, skcms_AlphaFormat_Unpremul, &srgb_linear, 1);

    expect(dst[0] == 1.0f);
    expect(dst[1] == 1.0f);
    expect(dst[2] == 1.0f);
    expect(dst[3] == 1.0f);

    free(srgb_ptr);
}

// This test is written with the expectation that we use A2B1, not A2B0.
#if 0
static void test_CLUT() {
    // Identity* transform from a v4 A2B profile to good old parametric sRGB.
    //   * Approximate identity, apparently?
    void  *srgb_ptr, *a2b_ptr;
    size_t srgb_len,  a2b_len;
    expect(load_file("profiles/mobile/sRGB_parametric.icc",           &srgb_ptr, &srgb_len));
    expect(load_file("profiles/color.org/sRGB_ICC_v4_Appearance.icc", & a2b_ptr, & a2b_len));

    skcms_ICCProfile srgb, a2b;
    expect( skcms_Parse(srgb_ptr, srgb_len, &srgb) );
    expect( skcms_Parse( a2b_ptr,  a2b_len, & a2b) );

    // We'll test some edge and middle RGB values.
    uint8_t src[] = {
        0x00, 0x00, 0x00,
        0x00, 0x00, 0x7f,
        0x00, 0x00, 0xff,
        0x00, 0x7f, 0x00,
        0x00, 0xff, 0x00,
        0x00, 0x7f, 0x7f,
        0x00, 0xff, 0xff,
        0x7f, 0x00, 0x00,
        0xff, 0x00, 0x00,
        0x7f, 0x00, 0x7f,
        0xff, 0x00, 0xff,
        0x7f, 0x7f, 0x00,
        0xff, 0xff, 0x00,
        0x7f, 0x7f, 0x7f,
        0xff, 0xff, 0xff,
    }, dst[ARRAY_COUNT(src)];

    expect(skcms_Transform(src, skcms_PixelFormat_RGB_888, skcms_AlphaFormat_Unpremul, &a2b,
                           dst, skcms_PixelFormat_RGB_888, skcms_AlphaFormat_Unpremul, &srgb,
                           ARRAY_COUNT(src)/3));

    for (int i = 0; i < ARRAY_COUNT(src); i++) {
        // We'd like these all to be perfect (tol = 0),
        // but that doesn't seem to be what the profile is telling us to do.
        int tol = 1;
        if (src[i] == 0) {
            tol = 9;
        }
        if (abs(dst[i] - src[i]) > tol) {
            printf("%d: %d vs %d\n", i, dst[i], src[i]);
        }
        expect(abs(dst[i] - src[i]) <= tol);
    }

    free(srgb_ptr);
    free(a2b_ptr);
}
#endif

int main(int argc, char** argv) {
    bool regenTestData = false;
    for (int i = 1; i < argc; ++i) {
        if (0 == strcmp(argv[i], "-t")) {
            regenTestData = true;
        }
    }

    test_ICCProfile();
    test_FormatConversions();
    test_FormatConversions_565();
    test_FormatConversions_16161616();
    test_FormatConversions_161616();
    test_FormatConversions_101010();
    test_FormatConversions_half();
    test_FormatConversions_float();
    test_Parse(regenTestData);
    test_TransferFunction_approximate();
    test_TransferFunction_approximate_clamped();
    test_Matrix3x3_invert();
    test_SimpleRoundTrip();
    test_FloatRoundTrips();
    test_sRGB_AllBytes();
    test_ByteToLinearFloat();
    test_TRC_Table16();
    test_Premul();
#if 0
    test_CLUT();
#endif

    return 0;
}