Playing with http://substack.neocities.org/video.html

gistfile1.js

//Visit http://substack.neocities.org/video.html and paste this into the text box.

var t = 0;
var t = 0;

return function (r, w) {
  t += 0.2;

  var gRad = Math.sin(t/5) * 50;
  var bRad = Math.sin(t/7) * 90;

//  var rX = Math.round(Math.sin(t) *3);
//  var rY = Math.round(Math.cos(t) * 3);
  var rOffset = 0;//4 * (rX + r.width * rY);

  var gX = Math.round(Math.sin(t + Math.PI) * gRad);
  var gY = Math.round(Math.cos(t + Math.PI) * gRad);
  var gOffset = 4 * (gX + r.width * gY);

  var bX = Math.round(Math.sin(t ) * bRad);
  var bY = Math.round(Math.cos(t) * bRad);
  var bOffset = 4 * (bX + r.width * bY);


  for (var i = 0; i < w.data.length; i += 4) {
    w.data[i] =r.data[i + rOffset];
    w.data[i+1] = r.data[i + 1 + gOffset];
    w.data[i+2] = r.data[i + 2 + bOffset];
    w.data[i+3] = 255;
  }
}