Qt 4.8: plasma.js Example File (script/context2d/scripts/plasma.js)

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- Qt 4.8
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# 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();