| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrSwizzle_DEFINED |
| #define GrSwizzle_DEFINED |
| |
| #include "GrTypes.h" |
| |
| /** Represents a rgba swizzle. It can be converted either into a string or a eight bit int. |
| Currently there is no way to specify an arbitrary swizzle, just some static swizzles and an |
| assignment operator. That could be relaxed. */ |
| class GrSwizzle { |
| public: |
| GrSwizzle() { *this = RGBA(); } |
| |
| GrSwizzle& operator=(const GrSwizzle& that) { |
| memcpy(this, &that, sizeof(GrSwizzle)); |
| return *this; |
| } |
| |
| bool operator==(const GrSwizzle& that) const { return this->asUInt() == that.asUInt(); } |
| |
| bool operator!=(const GrSwizzle& that) const { return !(*this == that); } |
| |
| /** Compact representation of the swizzle suitable for a key. */ |
| uint8_t asKey() const { return fKey; } |
| |
| /** 4 char null terminated string consisting only of chars 'r', 'g', 'b', 'a'. */ |
| const char* c_str() const { return fSwiz; } |
| |
| static const GrSwizzle& RGBA() { |
| static GrSwizzle gRGBA("rgba"); |
| return gRGBA; |
| } |
| |
| static const GrSwizzle& AAAA() { |
| static GrSwizzle gAAAA("aaaa"); |
| return gAAAA; |
| } |
| |
| static const GrSwizzle& RRRR() { |
| static GrSwizzle gRRRR("rrrr"); |
| return gRRRR; |
| } |
| |
| static const GrSwizzle& BGRA() { |
| static GrSwizzle gBGRA("bgra"); |
| return gBGRA; |
| } |
| |
| private: |
| char fSwiz[5]; |
| uint8_t fKey; |
| |
| static int CharToIdx(char c) { |
| switch (c) { |
| case 'r': |
| return 0; |
| case 'g': |
| return 1; |
| case 'b': |
| return 2; |
| case 'a': |
| return 3; |
| default: |
| SkFAIL("Invalid swizzle char"); |
| return 0; |
| } |
| } |
| |
| explicit GrSwizzle(const char* str) { |
| SkASSERT(strlen(str) == 4); |
| fSwiz[0] = str[0]; |
| fSwiz[1] = str[1]; |
| fSwiz[2] = str[2]; |
| fSwiz[3] = str[3]; |
| fSwiz[4] = 0; |
| fKey = SkToU8(CharToIdx(fSwiz[0]) | (CharToIdx(fSwiz[1]) << 2) | |
| (CharToIdx(fSwiz[2]) << 4) | (CharToIdx(fSwiz[3]) << 6)); |
| } |
| |
| uint32_t* asUIntPtr() { return SkTCast<uint32_t*>(fSwiz); } |
| uint32_t asUInt() const { return *SkTCast<const uint32_t*>(fSwiz); } |
| |
| GR_STATIC_ASSERT(sizeof(char[4]) == sizeof(uint32_t)); |
| }; |
| |
| #endif |