3 * Copyright 2010 Google Inc.
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
11 #ifndef GrColor_DEFINED
12 #define GrColor_DEFINED
17 * GrColor is 4 bytes for R, G, B, A, in a specific order defined below. The components are stored
20 typedef uint32_t GrColor;
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.
27 #define GrColor_SHIFT_R 24
28 #define GrColor_SHIFT_G 16
29 #define GrColor_SHIFT_B 8
30 #define GrColor_SHIFT_A 0
32 #define GrColor_SHIFT_R 0
33 #define GrColor_SHIFT_G 8
34 #define GrColor_SHIFT_B 16
35 #define GrColor_SHIFT_A 24
39 * Pack 4 components (RGBA) into a GrColor int
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);
53 // extract a component (byte) from a GrColor int
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)
61 * Since premultiplied means that alpha >= color, we construct a color with
62 * each component==255 and alpha == 0 to be "illegal"
64 #define GrColor_ILLEGAL (~(0xFF << GrColor_SHIFT_A))
67 * Assert in debug builds that a GrColor is premultiplied.
69 static inline void GrColorIsPMAssert(GrColor c) {
71 unsigned a = GrColorUnpackA(c);
72 unsigned r = GrColorUnpackR(c);
73 unsigned g = GrColorUnpackG(c);
74 unsigned b = GrColorUnpackB(c);
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;
92 * Flags used for bitfields of color components. They are defined so that the bit order reflects the
93 * GrColor shift order.
95 enum GrColorComponentFlags {
96 kR_GrColorComponentFlag = 1 << (GrColor_SHIFT_R / 8),
97 kG_GrColorComponentFlag = 1 << (GrColor_SHIFT_G / 8),
98 kB_GrColorComponentFlag = 1 << (GrColor_SHIFT_B / 8),
99 kA_GrColorComponentFlag = 1 << (GrColor_SHIFT_A / 8),
101 kRGB_GrColorComponentFlags = (kR_GrColorComponentFlag | kG_GrColorComponentFlag |
102 kB_GrColorComponentFlag),
104 kRGBA_GrColorComponentFlags = (kR_GrColorComponentFlag | kG_GrColorComponentFlag |
105 kB_GrColorComponentFlag | kA_GrColorComponentFlag)
108 static inline char GrColorComponentFlagToChar(GrColorComponentFlags component) {
109 SkASSERT(GrIsPow2(component));
111 case kR_GrColorComponentFlag:
113 case kG_GrColorComponentFlag:
115 case kB_GrColorComponentFlag:
117 case kA_GrColorComponentFlag:
120 SkFAIL("Invalid color component flag.");
125 static inline uint32_t GrPixelConfigComponentMask(GrPixelConfig config) {
126 SkASSERT(config >= 0 && config < kGrPixelConfigCnt);
127 static const uint32_t kFlags[] = {
128 0, // kUnknown_GrPixelConfig
129 kA_GrColorComponentFlag, // kAlpha_8_GrPixelConfig
130 kRGBA_GrColorComponentFlags, // kIndex_8_GrPixelConfig
131 kRGB_GrColorComponentFlags, // kRGB_565_GrPixelConfig
132 kRGBA_GrColorComponentFlags, // kRGBA_4444_GrPixelConfig
133 kRGBA_GrColorComponentFlags, // kRGBA_8888_GrPixelConfig
134 kRGBA_GrColorComponentFlags, // kBGRA_8888_GrPixelConfig
136 return kFlags[config];
138 GR_STATIC_ASSERT(0 == kUnknown_GrPixelConfig);
139 GR_STATIC_ASSERT(1 == kAlpha_8_GrPixelConfig);
140 GR_STATIC_ASSERT(2 == kIndex_8_GrPixelConfig);
141 GR_STATIC_ASSERT(3 == kRGB_565_GrPixelConfig);
142 GR_STATIC_ASSERT(4 == kRGBA_4444_GrPixelConfig);
143 GR_STATIC_ASSERT(5 == kRGBA_8888_GrPixelConfig);
144 GR_STATIC_ASSERT(6 == kBGRA_8888_GrPixelConfig);
145 GR_STATIC_ASSERT(SK_ARRAY_COUNT(kFlags) == kGrPixelConfigCnt);