qemu/pixman/demos/checkerboard.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include "pixman.h"
   4 #include "gtk-utils.h"
   5
   6 int
   7 main (int argc, char **argv)
   8 {
   9 #define WIDTH 400
  10 #define HEIGHT 400
  11 #define TILE_SIZE 25
  12
  13     pixman_image_t *checkerboard;
  14     pixman_image_t *destination;
  15 #define D2F(d) (pixman_double_to_fixed(d))
  16     pixman_transform_t trans = { {
  17             { D2F (-1.96830), D2F (-1.82250), D2F (512.12250)},
  18             { D2F (0.00000), D2F (-7.29000), D2F (1458.00000)},
  19             { D2F (0.00000), D2F (-0.00911), D2F (0.59231)},
  20         }};
  21     int i, j;
  22
  23     checkerboard = pixman_image_create_bits (PIXMAN_a8r8g8b8,
  24                                              WIDTH, HEIGHT,
  25                                              NULL, 0);
  26
  27     destination = pixman_image_create_bits (PIXMAN_a8r8g8b8,
  28                                             WIDTH, HEIGHT,
  29                                             NULL, 0);
  30
  31     for (i = 0; i < HEIGHT / TILE_SIZE; ++i)
  32     {
  33         for (j = 0; j < WIDTH / TILE_SIZE; ++j)
  34         {
  35             double u = (double)(j + 1) / (WIDTH / TILE_SIZE);
  36             double v = (double)(i + 1) / (HEIGHT / TILE_SIZE);
  37             pixman_color_t black = { 0, 0, 0, 0xffff };
  38             pixman_color_t white = {
  39                 v * 0xffff,
  40                 u * 0xffff,
  41                 (1 - (double)u) * 0xffff,
  42                 0xffff };
  43             pixman_color_t *c;
  44             pixman_image_t *fill;
  45
  46             if ((j & 1) != (i & 1))
  47                 c = &black;
  48             else
  49                 c = &white;
  50
  51             fill = pixman_image_create_solid_fill (c);
  52
  53             pixman_image_composite (PIXMAN_OP_SRC, fill, NULL, checkerboard,
  54                                     0, 0, 0, 0, j * TILE_SIZE, i * TILE_SIZE,
  55                                     TILE_SIZE, TILE_SIZE);
  56         }
  57     }
  58
  59     pixman_image_set_transform (checkerboard, &trans);
  60     pixman_image_set_filter (checkerboard, PIXMAN_FILTER_BEST, NULL, 0);
  61     pixman_image_set_repeat (checkerboard, PIXMAN_REPEAT_NONE);
  62
  63     pixman_image_composite (PIXMAN_OP_SRC,
  64                             checkerboard, NULL, destination,
  65                             0, 0, 0, 0, 0, 0,
  66                             WIDTH, HEIGHT);
  67
  68     show_image (destination);
  69
  70     return 0;
  71 }