SkColor.h revision e16efc1882ab34a0bb3ae361a2d37f840044cf87 
1
2/*
3 * Copyright 2006 The Android Open Source Project
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#ifndef SkColor_DEFINED
11#define SkColor_DEFINED
12
13#include "SkScalar.h"
14
15/** \file SkColor.h
16
17    Types and macros for colors
18*/
19
20/** 8-bit type for an alpha value. 0xFF is 100% opaque, 0x00 is 100% transparent.
21*/
22typedef uint8_t SkAlpha;
23/** 32 bit ARGB color value, not premultiplied. The color components are always in
24    a known order. This is different from SkPMColor, which has its bytes in a configuration
25    dependent order, to match the format of kARGB32 bitmaps. SkColor is the type used to
26    specify colors in SkPaint and in gradients.
27*/
28typedef uint32_t SkColor;
29
30/** Return a SkColor value from 8 bit component values
31*/
32static inline SkColor SkColorSetARGBInline(U8CPU a, U8CPU r, U8CPU g, U8CPU b)
33{
34    SkASSERT(a <= 255 && r <= 255 && g <= 255 && b <= 255);
35
36    return (a << 24) | (r << 16) | (g << 8) | (b << 0);
37}
38
39#define SkColorSetARGBMacro(a, r, g, b) \
40    static_cast<SkColor>( \
41        (static_cast<U8CPU>(a) << 24) | \
42        (static_cast<U8CPU>(r) << 16) | \
43        (static_cast<U8CPU>(g) << 8) | \
44        (static_cast<U8CPU>(b) << 0))
45
46/** gcc will generate static initializers for code of this form:
47 * static const SkColor kMyColor = SkColorSetARGB(0xFF, 0x01, 0x02, 0x03)
48 * if SkColorSetARGB() is a static inline, but not if it's a macro.
49 */
50#if defined(NDEBUG)
51#define SkColorSetARGB(a, r, g, b) SkColorSetARGBMacro(a, r, g, b)
52#else
53#define SkColorSetARGB(a, r, g, b) SkColorSetARGBInline(a, r, g, b)
54#endif
55
56/** Return a SkColor value from 8 bit component values, with an implied value
57    of 0xFF for alpha (fully opaque)
58*/
59#define SkColorSetRGB(r, g, b)  SkColorSetARGB(0xFF, r, g, b)
60
61/** return the alpha byte from a SkColor value */
62#define SkColorGetA(color)      (((color) >> 24) & 0xFF)
63/** return the red byte from a SkColor value */
64#define SkColorGetR(color)      (((color) >> 16) & 0xFF)
65/** return the green byte from a SkColor value */
66#define SkColorGetG(color)      (((color) >>  8) & 0xFF)
67/** return the blue byte from a SkColor value */
68#define SkColorGetB(color)      (((color) >>  0) & 0xFF)
69
70static inline SkColor SkColorSetA(SkColor c, U8CPU a) {
71    return (c & 0x00FFFFFF) | (a << 24);
72}
73
74// common colors
75
76#define SK_ColorTRANSPARENT 0x00000000  //!< transparent SkColor value
77
78#define SK_ColorBLACK       0xFF000000  //!< black SkColor value
79#define SK_ColorDKGRAY      0xFF444444  //!< dark gray SkColor value
80#define SK_ColorGRAY        0xFF888888  //!< gray SkColor value
81#define SK_ColorLTGRAY      0xFFCCCCCC  //!< light gray SkColor value
82#define SK_ColorWHITE       0xFFFFFFFF  //!< white SkColor value
83
84#define SK_ColorRED         0xFFFF0000  //!< red SkColor value
85#define SK_ColorGREEN       0xFF00FF00  //!< green SkColor value
86#define SK_ColorBLUE        0xFF0000FF  //!< blue SkColor value
87#define SK_ColorYELLOW      0xFFFFFF00  //!< yellow SkColor value
88#define SK_ColorCYAN        0xFF00FFFF  //!< cyan SkColor value
89#define SK_ColorMAGENTA     0xFFFF00FF  //!< magenta SkColor value
90
91////////////////////////////////////////////////////////////////////////
92
93/** Convert RGB components to HSV.
94        hsv[0] is Hue [0 .. 360)
95        hsv[1] is Saturation [0...1]
96        hsv[2] is Value [0...1]
97    @param red  red component value [0..255]
98    @param green  green component value [0..255]
99    @param blue  blue component value [0..255]
100    @param hsv  3 element array which holds the resulting HSV components.
101*/
102SK_API void SkRGBToHSV(U8CPU red, U8CPU green, U8CPU blue, SkScalar hsv[3]);
103
104/** Convert the argb color to its HSV components.
105        hsv[0] is Hue [0 .. 360)
106        hsv[1] is Saturation [0...1]
107        hsv[2] is Value [0...1]
108    @param color the argb color to convert. Note: the alpha component is ignored.
109    @param hsv  3 element array which holds the resulting HSV components.
110*/
111static inline void SkColorToHSV(SkColor color, SkScalar hsv[3])
112{
113    SkRGBToHSV(SkColorGetR(color), SkColorGetG(color), SkColorGetB(color), hsv);
114}
115
116/** Convert HSV components to an ARGB color. The alpha component is passed through unchanged.
117        hsv[0] is Hue [0 .. 360)
118        hsv[1] is Saturation [0...1]
119        hsv[2] is Value [0...1]
120    If hsv values are out of range, they are pinned.
121    @param alpha the alpha component of the returned argb color.
122    @param hsv  3 element array which holds the input HSV components.
123    @return the resulting argb color
124*/
125SK_API SkColor SkHSVToColor(U8CPU alpha, const SkScalar hsv[3]);
126
127/** Convert HSV components to an ARGB color. The alpha component set to 0xFF.
128        hsv[0] is Hue [0 .. 360)
129        hsv[1] is Saturation [0...1]
130        hsv[2] is Value [0...1]
131    If hsv values are out of range, they are pinned.
132    @param hsv  3 element array which holds the input HSV components.
133    @return the resulting argb color
134*/
135static inline SkColor SkHSVToColor(const SkScalar hsv[3])
136{
137    return SkHSVToColor(0xFF, hsv);
138}
139
140////////////////////////////////////////////////////////////////////////
141
142/** 32 bit ARGB color value, premultiplied. The byte order for this value is
143    configuration dependent, matching the format of kARGB32 bitmaps. This is different
144    from SkColor, which is nonpremultiplied, and is always in the same byte order.
145*/
146typedef uint32_t SkPMColor;
147
148/** Return a SkPMColor value from unpremultiplied 8 bit component values
149*/
150SK_API SkPMColor SkPreMultiplyARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b);
151/** Return a SkPMColor value from a SkColor value. This is done by multiplying the color
152    components by the color's alpha, and by arranging the bytes in a configuration
153    dependent order, to match the format of kARGB32 bitmaps.
154*/
155SK_API SkPMColor SkPreMultiplyColor(SkColor c);
156
157/** Define a function pointer type for combining two premultiplied colors
158*/
159typedef SkPMColor (*SkXfermodeProc)(SkPMColor src, SkPMColor dst);
160
161/** Define a function pointer type for combining a premultiplied src color
162    and a 16bit device color.
163*/
164typedef uint16_t (*SkXfermodeProc16)(SkPMColor src, uint16_t dst);
165
166#endif
167