1 2 /* 3 * Copyright 2010 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 11 #ifndef GrColor_DEFINED 12 #define GrColor_DEFINED 13 14 #include "GrTypes.h" 15 16 /** 17 * GrColor is 4 bytes for R, G, B, A, in a specific order defined below. The components are stored 18 * premultiplied. 19 */ 20 typedef uint32_t GrColor; 21 22 // shift amount to assign a component to a GrColor int 23 // These shift values are chosen for compatibility with GL attrib arrays 24 // ES doesn't allow BGRA vertex attrib order so if they were not in this order 25 // we'd have to swizzle in shaders. 26 #ifdef SK_CPU_BENDIAN 27 #define GrColor_SHIFT_R 24 28 #define GrColor_SHIFT_G 16 29 #define GrColor_SHIFT_B 8 30 #define GrColor_SHIFT_A 0 31 #else 32 #define GrColor_SHIFT_R 0 33 #define GrColor_SHIFT_G 8 34 #define GrColor_SHIFT_B 16 35 #define GrColor_SHIFT_A 24 36 #endif 37 38 /** 39 * Pack 4 components (RGBA) into a GrColor int 40 */ 41 static inline GrColor GrColorPackRGBA(unsigned r, unsigned g, 42 unsigned b, unsigned a) { 43 SkASSERT((uint8_t)r == r); 44 SkASSERT((uint8_t)g == g); 45 SkASSERT((uint8_t)b == b); 46 SkASSERT((uint8_t)a == a); 47 return (r << GrColor_SHIFT_R) | 48 (g << GrColor_SHIFT_G) | 49 (b << GrColor_SHIFT_B) | 50 (a << GrColor_SHIFT_A); 51 } 52 53 // extract a component (byte) from a GrColor int 54 55 #define GrColorUnpackR(color) (((color) >> GrColor_SHIFT_R) & 0xFF) 56 #define GrColorUnpackG(color) (((color) >> GrColor_SHIFT_G) & 0xFF) 57 #define GrColorUnpackB(color) (((color) >> GrColor_SHIFT_B) & 0xFF) 58 #define GrColorUnpackA(color) (((color) >> GrColor_SHIFT_A) & 0xFF) 59 60 /** 61 * Since premultiplied means that alpha >= color, we construct a color with 62 * each component==255 and alpha == 0 to be "illegal" 63 */ 64 #define GrColor_ILLEGAL (~(0xFF << GrColor_SHIFT_A)) 65 66 /** 67 * Assert in debug builds that a GrColor is premultiplied. 68 */ 69 static inline void GrColorIsPMAssert(GrColor c) { 70 #ifdef SK_DEBUG 71 unsigned a = GrColorUnpackA(c); 72 unsigned r = GrColorUnpackR(c); 73 unsigned g = GrColorUnpackG(c); 74 unsigned b = GrColorUnpackB(c); 75 76 SkASSERT(r <= a); 77 SkASSERT(g <= a); 78 SkASSERT(b <= a); 79 #endif 80 } 81 82 /** Converts a GrColor to an rgba array of GrGLfloat */ 83 static inline void GrColorToRGBAFloat(GrColor color, float rgba[4]) { 84 static const float ONE_OVER_255 = 1.f / 255.f; 85 rgba[0] = GrColorUnpackR(color) * ONE_OVER_255; 86 rgba[1] = GrColorUnpackG(color) * ONE_OVER_255; 87 rgba[2] = GrColorUnpackB(color) * ONE_OVER_255; 88 rgba[3] = GrColorUnpackA(color) * ONE_OVER_255; 89 } 90 91 /** Determines whether the color is opaque or not. */ 92 static inline bool GrColorIsOpaque(GrColor color) { 93 return (color & (0xFFU << GrColor_SHIFT_A)) == (0xFFU << GrColor_SHIFT_A); 94 } 95 96 /** 97 * Flags used for bitfields of color components. They are defined so that the bit order reflects the 98 * GrColor shift order. 99 */ 100 enum GrColorComponentFlags { 101 kR_GrColorComponentFlag = 1 << (GrColor_SHIFT_R / 8), 102 kG_GrColorComponentFlag = 1 << (GrColor_SHIFT_G / 8), 103 kB_GrColorComponentFlag = 1 << (GrColor_SHIFT_B / 8), 104 kA_GrColorComponentFlag = 1 << (GrColor_SHIFT_A / 8), 105 106 kRGB_GrColorComponentFlags = (kR_GrColorComponentFlag | kG_GrColorComponentFlag | 107 kB_GrColorComponentFlag), 108 109 kRGBA_GrColorComponentFlags = (kR_GrColorComponentFlag | kG_GrColorComponentFlag | 110 kB_GrColorComponentFlag | kA_GrColorComponentFlag) 111 }; 112 113 static inline char GrColorComponentFlagToChar(GrColorComponentFlags component) { 114 SkASSERT(SkIsPow2(component)); 115 switch (component) { 116 case kR_GrColorComponentFlag: 117 return 'r'; 118 case kG_GrColorComponentFlag: 119 return 'g'; 120 case kB_GrColorComponentFlag: 121 return 'b'; 122 case kA_GrColorComponentFlag: 123 return 'a'; 124 default: 125 SkFAIL("Invalid color component flag."); 126 return '\0'; 127 } 128 } 129 130 static inline uint32_t GrPixelConfigComponentMask(GrPixelConfig config) { 131 SkASSERT(config >= 0 && config < kGrPixelConfigCnt); 132 static const uint32_t kFlags[] = { 133 0, // kUnknown_GrPixelConfig 134 kA_GrColorComponentFlag, // kAlpha_8_GrPixelConfig 135 kRGBA_GrColorComponentFlags, // kIndex_8_GrPixelConfig 136 kRGB_GrColorComponentFlags, // kRGB_565_GrPixelConfig 137 kRGBA_GrColorComponentFlags, // kRGBA_4444_GrPixelConfig 138 kRGBA_GrColorComponentFlags, // kRGBA_8888_GrPixelConfig 139 kRGBA_GrColorComponentFlags, // kBGRA_8888_GrPixelConfig 140 kRGB_GrColorComponentFlags, // kETC1_GrPixelConfig 141 kA_GrColorComponentFlag, // kLATC_GrPixelConfig 142 kA_GrColorComponentFlag, // kR11_EAC_GrPixelConfig 143 kRGBA_GrColorComponentFlags, // kASTC_12x12_GrPixelConfig 144 kRGBA_GrColorComponentFlags, // kRGBA_float_GrPixelConfig 145 }; 146 return kFlags[config]; 147 148 GR_STATIC_ASSERT(0 == kUnknown_GrPixelConfig); 149 GR_STATIC_ASSERT(1 == kAlpha_8_GrPixelConfig); 150 GR_STATIC_ASSERT(2 == kIndex_8_GrPixelConfig); 151 GR_STATIC_ASSERT(3 == kRGB_565_GrPixelConfig); 152 GR_STATIC_ASSERT(4 == kRGBA_4444_GrPixelConfig); 153 GR_STATIC_ASSERT(5 == kRGBA_8888_GrPixelConfig); 154 GR_STATIC_ASSERT(6 == kBGRA_8888_GrPixelConfig); 155 GR_STATIC_ASSERT(7 == kETC1_GrPixelConfig); 156 GR_STATIC_ASSERT(8 == kLATC_GrPixelConfig); 157 GR_STATIC_ASSERT(9 == kR11_EAC_GrPixelConfig); 158 GR_STATIC_ASSERT(10 == kASTC_12x12_GrPixelConfig); 159 GR_STATIC_ASSERT(11 == kRGBA_float_GrPixelConfig); 160 GR_STATIC_ASSERT(SK_ARRAY_COUNT(kFlags) == kGrPixelConfigCnt); 161 } 162 163 #endif 164
