requestAnimationFrame polyfill

rAF.js

// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating

// requestAnimationFrame polyfill by Erik Möller. fixes from Paul Irish and Tino Zijdel

// MIT license

(function() {
    function checkAnimationFrame() {
            var lastTime = 0;
            var vendors = ['ms', 'moz', 'webkit', 'o'];
            for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
                window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
                window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] 
                                           || window[vendors[x]+'CancelRequestAnimationFrame'];
            }
         
            if (!window.requestAnimationFrame)
                window.requestAnimationFrame = function(callback, element) {
                    var currTime = new Date().getTime();
                    var timeToCall = Math.max(0, 16 - (currTime - lastTime));
                    var id = window.setTimeout(function() { callback(currTime + timeToCall); }, 
                      timeToCall);
                    lastTime = currTime + timeToCall;
                    return id;
                };
         
            if (!window.cancelAnimationFrame)
                window.cancelAnimationFrame = function(id) {
                    clearTimeout(id);
                };
          }

          var cb = function() {
            var l = document.createElement('link'); l.rel = 'stylesheet';
            l.href = 'css/main.min.css';
            var h = document.getElementsByTagName('head')[0]; h.parentNode.insertBefore(l, h);
            
            document.body.className = "";
          };
          checkAnimationFrame();

          var raf = requestAnimationFrame || mozRequestAnimationFrame ||
              webkitRequestAnimationFrame || msRequestAnimationFrame;
          if (raf) raf(cb);
          else 
            window.addEventListener('load', cb);
}());