1 /*
2 * Example program for the Allegro library, by Shawn Hargreaves.
3 *
4 * This program shows how to specify colors in the various different
5 * truecolor pixel formats. The example shows the same screen (a few
6 * text lines and three coloured gradients) in all the color depth
7 * modes supported by your video card. The more color depth you have,
8 * the less banding you will see in the gradients.
9 */
10
11
12 #include <allegro.h>
13
14
15
test(int colordepth)16 void test(int colordepth)
17 {
18 PALETTE pal;
19 int x;
20
21 /* set the screen mode */
22 set_color_depth(colordepth);
23
24 if (set_gfx_mode(GFX_AUTODETECT, 640, 480, 0, 0) != 0)
25 return;
26
27 /* in case this is a 256 color mode, we'd better make sure that the
28 * palette is set to something sensible. This function generates a
29 * standard palette with a nice range of different colors...
30 */
31 generate_332_palette(pal);
32 set_palette(pal);
33
34 acquire_screen();
35
36 clear_to_color(screen, makecol(0, 0, 0));
37
38 textprintf_ex(screen, font, 0, 0, makecol(255, 255, 255), -1,
39 "%d bit color...", colordepth);
40
41 /* use the makecol() function to specify RGB values... */
42 textout_ex(screen, font, "Red", 32, 80, makecol(255, 0, 0 ), -1);
43 textout_ex(screen, font, "Green", 32, 100, makecol(0, 255, 0 ), -1);
44 textout_ex(screen, font, "Blue", 32, 120, makecol(0, 0, 255), -1);
45 textout_ex(screen, font, "Yellow", 32, 140, makecol(255, 255, 0 ), -1);
46 textout_ex(screen, font, "Cyan", 32, 160, makecol(0, 255, 255), -1);
47 textout_ex(screen, font, "Magenta", 32, 180, makecol(255, 0, 255), -1);
48 textout_ex(screen, font, "Grey", 32, 200, makecol(128, 128, 128), -1);
49
50 /* or we could draw some nice smooth color gradients... */
51 for (x=0; x<256; x++) {
52 vline(screen, 192+x, 112, 176, makecol(x, 0, 0));
53 vline(screen, 192+x, 208, 272, makecol(0, x, 0));
54 vline(screen, 192+x, 304, 368, makecol(0, 0, x));
55 }
56
57 textout_centre_ex(screen, font, "<press a key>", SCREEN_W/2, SCREEN_H-16,
58 makecol(255, 255, 255), -1);
59
60 release_screen();
61
62 readkey();
63 }
64
65
66
main(void)67 int main(void)
68 {
69 if (allegro_init() != 0)
70 return 1;
71 install_keyboard();
72
73 /* try each of the possible possible color depths... */
74 test(8);
75 test(15);
76 test(16);
77 test(24);
78 test(32);
79
80 return 0;
81 }
82
83 END_OF_MAIN()
84