00b2939890
Bug: skia: Change-Id: I395395b1cd81a1d45ca779b2273015c8ed9fb882 Reviewed-on: https://skia-review.googlesource.com/c/168361 Commit-Queue: Brian Osman <brianosman@google.com> Reviewed-by: Mike Klein <mtklein@google.com>
94 lines
2.9 KiB
C
94 lines
2.9 KiB
C
|
|
/*
|
|
* Copyright 2010 Google Inc.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license that can be
|
|
* found in the LICENSE file.
|
|
*/
|
|
|
|
|
|
|
|
#ifndef GrColor_DEFINED
|
|
#define GrColor_DEFINED
|
|
|
|
#include "SkColor.h"
|
|
#include "SkColorPriv.h"
|
|
|
|
/**
|
|
* GrColor is 4 bytes for R, G, B, A, in a specific order defined below. Whether the color is
|
|
* premultiplied or not depends on the context in which it is being used.
|
|
*/
|
|
typedef uint32_t GrColor;
|
|
|
|
// shift amount to assign a component to a GrColor int
|
|
// These shift values are chosen for compatibility with GL attrib arrays
|
|
// ES doesn't allow BGRA vertex attrib order so if they were not in this order
|
|
// we'd have to swizzle in shaders.
|
|
#ifdef SK_CPU_BENDIAN
|
|
#define GrColor_SHIFT_R 24
|
|
#define GrColor_SHIFT_G 16
|
|
#define GrColor_SHIFT_B 8
|
|
#define GrColor_SHIFT_A 0
|
|
#else
|
|
#define GrColor_SHIFT_R 0
|
|
#define GrColor_SHIFT_G 8
|
|
#define GrColor_SHIFT_B 16
|
|
#define GrColor_SHIFT_A 24
|
|
#endif
|
|
|
|
/**
|
|
* Pack 4 components (RGBA) into a GrColor int
|
|
*/
|
|
static inline GrColor GrColorPackRGBA(unsigned r, unsigned g, unsigned b, unsigned a) {
|
|
SkASSERT((uint8_t)r == r);
|
|
SkASSERT((uint8_t)g == g);
|
|
SkASSERT((uint8_t)b == b);
|
|
SkASSERT((uint8_t)a == a);
|
|
return (r << GrColor_SHIFT_R) |
|
|
(g << GrColor_SHIFT_G) |
|
|
(b << GrColor_SHIFT_B) |
|
|
(a << GrColor_SHIFT_A);
|
|
}
|
|
|
|
/**
|
|
* Packs a color with an alpha channel replicated across all four channels.
|
|
*/
|
|
static inline GrColor GrColorPackA4(unsigned a) {
|
|
SkASSERT((uint8_t)a == a);
|
|
return (a << GrColor_SHIFT_R) |
|
|
(a << GrColor_SHIFT_G) |
|
|
(a << GrColor_SHIFT_B) |
|
|
(a << GrColor_SHIFT_A);
|
|
}
|
|
|
|
// extract a component (byte) from a GrColor int
|
|
|
|
#define GrColorUnpackR(color) (((color) >> GrColor_SHIFT_R) & 0xFF)
|
|
#define GrColorUnpackG(color) (((color) >> GrColor_SHIFT_G) & 0xFF)
|
|
#define GrColorUnpackB(color) (((color) >> GrColor_SHIFT_B) & 0xFF)
|
|
#define GrColorUnpackA(color) (((color) >> GrColor_SHIFT_A) & 0xFF)
|
|
|
|
/**
|
|
* Since premultiplied means that alpha >= color, we construct a color with
|
|
* each component==255 and alpha == 0 to be "illegal"
|
|
*/
|
|
#define GrColor_ILLEGAL (~(0xFF << GrColor_SHIFT_A))
|
|
|
|
#define GrColor_WHITE 0xFFFFFFFF
|
|
|
|
static inline GrColor GrColorMul(GrColor c0, GrColor c1) {
|
|
U8CPU r = SkMulDiv255Round(GrColorUnpackR(c0), GrColorUnpackR(c1));
|
|
U8CPU g = SkMulDiv255Round(GrColorUnpackG(c0), GrColorUnpackG(c1));
|
|
U8CPU b = SkMulDiv255Round(GrColorUnpackB(c0), GrColorUnpackB(c1));
|
|
U8CPU a = SkMulDiv255Round(GrColorUnpackA(c0), GrColorUnpackA(c1));
|
|
return GrColorPackRGBA(r, g, b, a);
|
|
}
|
|
|
|
/** Normalizes and coverts an uint8_t to a float. [0, 255] -> [0.0, 1.0] */
|
|
static inline float GrNormalizeByteToFloat(uint8_t value) {
|
|
static const float ONE_OVER_255 = 1.f / 255.f;
|
|
return value * ONE_OVER_255;
|
|
}
|
|
|
|
#endif
|