1 # Guess the result of mixing two colors.
 2 
 3 fn main screen: (addr screen), keyboard: (addr keyboard), data-disk: (addr disk) {
 4   var second-buffer: screen
 5   var second-screen/edi: (addr screen) <- address second-buffer
 6   initialize-screen second-screen, 0x80, 0x30, 1/include-pixels
 7   var leftx/edx: int <- copy 0x80
 8   var rightx/ebx: int <- copy 0x380
 9   {
10     compare leftx, rightx
11     break-if->=
12     clear-screen second-screen
13     # interesting value: 9/blue with 0xe/yellow
14     color-field second-screen, leftx 0x40/y, 0x40/width 0x40/height, 1/blue
15     color-field second-screen, rightx 0x41/y, 0x40/width 0x40/height, 2/green
16     copy-pixels second-screen, screen
17     # on the first iteration, give everyone a chance to make their guess
18     {
19       compare leftx, 0x80
20       break-if->
21       var x/eax: byte <- read-key keyboard
22       compare x, 0
23       loop-if-=
24     }
25     leftx <- add 2
26     rightx <- subtract 2
27     loop
28   }
29 }
30 
31 fn color-field screen: (addr screen), xmin: int, ymin: int, width: int, height: int, color: int {
32   var xmax/esi: int <- copy xmin
33   xmax <- add width
34   var ymax/edi: int <- copy ymin
35   ymax <- add height
36   var y/eax: int <- copy ymin
37   {
38     compare y, ymax
39     break-if->=
40     var x/ecx: int <- copy xmin
41     {
42       compare x, xmax
43       break-if->=
44       pixel screen, x, y, color
45       x <- add 2
46       loop
47     }
48     y <- increment
49     compare y, ymax
50     break-if->=
51     var x/ecx: int <- copy xmin
52     x <- increment
53     {
54       compare x, xmax
55       break-if->=
56       pixel screen, x, y, color
57       x <- add 2
58       loop
59     }
60     y <- increment
61     loop
62   }
63 }