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      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 */
     22 typedef 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 */
     28 typedef uint32_t SkColor;
     29 
     30 /** Return a SkColor value from 8 bit component values
     31 */
     32 static 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 
     70 static inline SkColor SkColorSetA(SkColor c, U8CPU a) {
     71     return (c & 0x00FFFFFF) | (a << 24);
     72 }
     73 
     74 // common colors
     75 
     76 #define SK_AlphaTRANSPARENT 0x00        //!< transparent SkAlpha value
     77 #define SK_AlphaOPAQUE      0xFF        //!< opaque SkAlpha value
     78 
     79 #define SK_ColorTRANSPARENT 0x00000000  //!< transparent SkColor value
     80 
     81 #define SK_ColorBLACK       0xFF000000  //!< black SkColor value
     82 #define SK_ColorDKGRAY      0xFF444444  //!< dark gray SkColor value
     83 #define SK_ColorGRAY        0xFF888888  //!< gray SkColor value
     84 #define SK_ColorLTGRAY      0xFFCCCCCC  //!< light gray SkColor value
     85 #define SK_ColorWHITE       0xFFFFFFFF  //!< white SkColor value
     86 
     87 #define SK_ColorRED         0xFFFF0000  //!< red SkColor value
     88 #define SK_ColorGREEN       0xFF00FF00  //!< green SkColor value
     89 #define SK_ColorBLUE        0xFF0000FF  //!< blue SkColor value
     90 #define SK_ColorYELLOW      0xFFFFFF00  //!< yellow SkColor value
     91 #define SK_ColorCYAN        0xFF00FFFF  //!< cyan SkColor value
     92 #define SK_ColorMAGENTA     0xFFFF00FF  //!< magenta SkColor value
     93 
     94 ////////////////////////////////////////////////////////////////////////
     95 
     96 /** Convert RGB components to HSV.
     97         hsv[0] is Hue [0 .. 360)
     98         hsv[1] is Saturation [0...1]
     99         hsv[2] is Value [0...1]
    100     @param red  red component value [0..255]
    101     @param green  green component value [0..255]
    102     @param blue  blue component value [0..255]
    103     @param hsv  3 element array which holds the resulting HSV components.
    104 */
    105 SK_API void SkRGBToHSV(U8CPU red, U8CPU green, U8CPU blue, SkScalar hsv[3]);
    106 
    107 /** Convert the argb color to its HSV components.
    108         hsv[0] is Hue [0 .. 360)
    109         hsv[1] is Saturation [0...1]
    110         hsv[2] is Value [0...1]
    111     @param color the argb color to convert. Note: the alpha component is ignored.
    112     @param hsv  3 element array which holds the resulting HSV components.
    113 */
    114 static inline void SkColorToHSV(SkColor color, SkScalar hsv[3])
    115 {
    116     SkRGBToHSV(SkColorGetR(color), SkColorGetG(color), SkColorGetB(color), hsv);
    117 }
    118 
    119 /** Convert HSV components to an ARGB color. The alpha component is passed through unchanged.
    120         hsv[0] is Hue [0 .. 360)
    121         hsv[1] is Saturation [0...1]
    122         hsv[2] is Value [0...1]
    123     If hsv values are out of range, they are pinned.
    124     @param alpha the alpha component of the returned argb color.
    125     @param hsv  3 element array which holds the input HSV components.
    126     @return the resulting argb color
    127 */
    128 SK_API SkColor SkHSVToColor(U8CPU alpha, const SkScalar hsv[3]);
    129 
    130 /** Convert HSV components to an ARGB color. The alpha component set to 0xFF.
    131         hsv[0] is Hue [0 .. 360)
    132         hsv[1] is Saturation [0...1]
    133         hsv[2] is Value [0...1]
    134     If hsv values are out of range, they are pinned.
    135     @param hsv  3 element array which holds the input HSV components.
    136     @return the resulting argb color
    137 */
    138 static inline SkColor SkHSVToColor(const SkScalar hsv[3])
    139 {
    140     return SkHSVToColor(0xFF, hsv);
    141 }
    142 
    143 ////////////////////////////////////////////////////////////////////////
    144 
    145 /** 32 bit ARGB color value, premultiplied. The byte order for this value is
    146     configuration dependent, matching the format of kARGB32 bitmaps. This is different
    147     from SkColor, which is nonpremultiplied, and is always in the same byte order.
    148 */
    149 typedef uint32_t SkPMColor;
    150 
    151 /** Return a SkPMColor value from unpremultiplied 8 bit component values
    152 */
    153 SK_API SkPMColor SkPreMultiplyARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b);
    154 /** Return a SkPMColor value from a SkColor value. This is done by multiplying the color
    155     components by the color's alpha, and by arranging the bytes in a configuration
    156     dependent order, to match the format of kARGB32 bitmaps.
    157 */
    158 SK_API SkPMColor SkPreMultiplyColor(SkColor c);
    159 
    160 /** Define a function pointer type for combining two premultiplied colors
    161 */
    162 typedef SkPMColor (*SkXfermodeProc)(SkPMColor src, SkPMColor dst);
    163 
    164 /** Define a function pointer type for combining a premultiplied src color
    165     and a 16bit device color.
    166 */
    167 typedef uint16_t (*SkXfermodeProc16)(SkPMColor src, uint16_t dst);
    168 
    169 #endif
    170