source: trunk/examples/script/context2d/scripts/plasma.js@ 266

Last change on this file since 266 was 2, checked in by Dmitry A. Kuminov, 16 years ago

Initially imported qt-all-opensource-src-4.5.1 from Trolltech.

File size: 1.1 KB
Line 
1var counter = 0;
2
3var PIXEL_SIZE = 4;
4
5var temp_1 = 0;
6
7function init()
8{
9 setInterval('render()',50);
10}
11
12function dist(a, b, c, d)
13{
14 return Math.sqrt((a - c) * (a - c) + (b - d) * (b - d));
15}
16
17
18function render()
19{
20 var canvas = document.getElementById('tutorial');
21 canvas.resize(128, 128);
22 var ctx = canvas.getContext('2d');
23 ctx.save();
24
25 var time = counter * 5;
26
27
28 for( y = 0; y < 128; y+=PIXEL_SIZE) {
29 for( x = 0 ; x < 128; x+=PIXEL_SIZE) {
30
31
32 var temp_val = Math.floor(Math.sin(dist(x + time, y, 128.0, 128.0) / 8.0)
33 + Math.sin(dist(x, y, 64.0, 64.0) / 8.0)
34 + Math.sin(dist(x, y + time / 7, 192.0, 64) / 7.0)
35 + Math.sin(dist(x, y, 192.0, 100.0) / 8.0));
36
37
38
39
40 var temp_col = Math.floor((2 + temp_val) * 50);
41
42 var rand_red = temp_col * 3;
43 var rand_green = temp_col ;
44 var rand_blue = 128 - temp_col;
45
46 ctx.fillStyle = "rgb("+rand_red+","+rand_green+","+rand_blue+")";
47
48 ctx.fillRect(x,y,PIXEL_SIZE,PIXEL_SIZE);
49 }
50 }
51
52
53 ctx.restore();
54 counter++;
55
56}
57
58init();
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