MeeGo 1.2 Harmattan Developer Documentation Develop for the Nokia N9

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();