plasma.js Example File

script/context2d/scripts/plasma.js
var counter = 0;
var PIXEL_SIZE = 4;
var temp_1 = 0;
function init()
{
    setInterval('render()',50);
}
function dist(a, b, c, d)
{
    return Math.sqrt((a - c) * (a - c) + (b - d) * (b - d));
}
function render()
{
    var canvas = document.getElementById('tutorial');
    canvas.resize(128, 128);
    var ctx = canvas.getContext('2d');
    ctx.save();
    var time = counter * 5;
    for( y = 0; y < 128; y+=PIXEL_SIZE) {
        for( x = 0 ; x < 128; x+=PIXEL_SIZE) {
            var temp_val = Math.floor(Math.sin(dist(x + time, y, 128.0, 128.0) / 8.0)
                                      + Math.sin(dist(x, y, 64.0, 64.0) / 8.0)
                                      + Math.sin(dist(x, y + time / 7, 192.0, 64) / 7.0)
                                      + Math.sin(dist(x, y, 192.0, 100.0) / 8.0));
            var temp_col = Math.floor((2 + temp_val) * 50);
            var rand_red = temp_col * 3;
            var rand_green = temp_col  ;
            var rand_blue = 128 - temp_col;
            ctx.fillStyle = "rgb("+rand_red+","+rand_green+","+rand_blue+")";
            ctx.fillRect(x,y,PIXEL_SIZE,PIXEL_SIZE);
        }
    }
    ctx.restore();
    counter++;
}
init();