window.requestAnimationFrame =
window ._requestAnimationFrame ||
window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame
window.oRequestAnimationFrame
window.msRequestAnimationFrame
(function () {
return function (callback, element) {
var lastTime = element._lastTime;
if (lastTime === undefined) {
lastTime = 0;
}
var currTime = Date.now();
var timeToCall = Math.max(1, 33 - (currTime-lastTime));
window.setTimeout(callback, timeToCall);
element ._ lastTime = currTime + timeToCall;
};
} )();