Dogcows Code - chaz/rasterize/blob - color.h

   1
   2 /*
   3  * CS5600 University of Utah
   4  * Charles McGarvey
   5  * mcgarvey@eng.utah.edu
   6  */
   7
   8 #ifndef __COLOR_H__
   9 #define __COLOR_H__
  10
  11 #include "common.h"
  12
  13
  14 /*
  15  * A color channel will be the same as a scalar.
  16  */
  17 typedef scal_t colorchan_t;
  18
  19 /*
  20  * A color class.
  21  * Colors are represented by RGBA values between 0.0 and 1.0.
  22  */
  23 struct color
  24 {
  25     colorchan_t r;
  26     colorchan_t g;
  27     colorchan_t b;
  28     colorchan_t a;
  29 };
  30 typedef struct color color_t;
  31
  32 /*
  33  * Initialize a color.
  34  */
  35 __fast__
  36 void color_init(color_t* c, colorchan_t r, colorchan_t g, colorchan_t b, colorchan_t a)
  37 {
  38     c->r = r;
  39     c->g = g;
  40     c->b = b;
  41     c->a = a;
  42 }
  43
  44
  45 /*
  46  * Create a new color, copied by value.
  47  */
  48 __fast__
  49 color_t color_new(colorchan_t r, colorchan_t g, colorchan_t b, colorchan_t a)
  50 {
  51     color_t c;
  52     color_init(&c, r, g, b, a);
  53     return c;
  54 }
  55
  56 #define COLOR_CLEAR   color_new(S(0.0), S(0.0), S(0.0), S(0.0))
  57 #define COLOR_BLACK   color_new(S(0.0), S(0.0), S(0.0), S(1.0))
  58 #define COLOR_RED     color_new(S(1.0), S(0.0), S(0.0), S(1.0))
  59 #define COLOR_GREEN   color_new(S(0.0), S(1.0), S(0.0), S(1.0))
  60 #define COLOR_BLUE    color_new(S(0.0), S(0.0), S(1.0), S(1.0))
  61 #define COLOR_YELLOW  color_new(S(1.0), S(1.0), S(0.0), S(1.0))
  62 #define COLOR_MAGENTA color_new(S(1.0), S(0.0), S(1.0), S(1.0))
  63 #define COLOR_CYAN    color_new(S(0.0), S(1.0), S(1.0), S(1.0))
  64 #define COLOR_WHITE   color_new(S(1.0), S(1.0), S(1.0), S(1.0))
  65
  66
  67 /*
  68  * Define integer types for a 32-bit RGBA color representation.
  69  */
  70 typedef uint32_t    rgba_t;
  71 typedef uint8_t     rgbachan_t;
  72
  73 /*
  74  * Create a new color from a 32-bit RGBA value.
  75  */
  76 __fast__
  77 color_t color_from_rgba(rgba_t n)
  78 {
  79     colorchan_t r = (colorchan_t)UNPACK(n, 3) / S(255.0);
  80     colorchan_t g = (colorchan_t)UNPACK(n, 2) / S(255.0);
  81     colorchan_t b = (colorchan_t)UNPACK(n, 1) / S(255.0);
  82     colorchan_t a = (colorchan_t)UNPACK(n, 0) / S(255.0);
  83     return color_new(r, g, b, a);
  84 }
  85
  86 /*
  87  * Split a color into 8-bit RGBA channels.
  88  */
  89 __fast__
  90 void color_split(color_t c, rgbachan_t* r, rgbachan_t* g, rgbachan_t* b, rgbachan_t* a)
  91 {
  92     if (r) *r = (rgbachan_t)(c.r * S(255.0));
  93     if (g) *g = (rgbachan_t)(c.g * S(255.0));
  94     if (b) *b = (rgbachan_t)(c.b * S(255.0));
  95     if (a) *a = (rgbachan_t)(c.a * S(255.0));
  96 }
  97
  98 /*
  99  * Convert a color to a 32-bit RGBA value.
 100  */
 101 __fast__
 102 rgba_t rgba_from_color(color_t c)
 103 {
 104     rgbachan_t r, g, b, a;
 105     color_split(c, &r, &g, &b, &a);
 106     return ((rgba_t)r << 24) | ((rgba_t)g << 16) | ((rgba_t)b << 8) | (rgba_t)a;
 107 }
 108
 109
 110 #endif // __COLOR_H__
 111