jQuery RequestAnimationFrame Plugin

jquery.raf.js

(function(jQuery){
	'use strict';
	if (!Date.now) Date.now = function() { return new Date().getTime(); };

	var animating,
		vendors = ['moz', 'webkit'],
		W = window;

	for (var i = 0; i < vendors.length && !W.requestAnimationFrame; ++i) {
		var vp = vendors[i];
	    W.requestAnimationFrame = W[vp+'RequestAnimationFrame'];
		W.cancelAnimationFrame = (W[vp+'CancelAnimationFrame'] || W[vp+'CancelRequestAnimationFrame']);
	}

	function raf() {
		if (animating) {
			requestAnimationFrame(raf);
			jQuery.fx.tick();
		}
	}

	if (!/iP(ad|hone|od).*OS 6/.test(W.navigator.userAgent) && W.requestAnimationFrame && W.cancelAnimationFrame ) {
		jQuery.fx.timer = function(timer) {
			if (timer() && jQuery.timers.push(timer) && !animating) {
				animating = true;
				raf();
			}
		};
		jQuery.fx.stop = function() {
			animating = false;
		};
	} else {
		var lastTime = 0;
	    W.requestAnimationFrame = function(callback) {
	        var now = Date.now(),
				nextTime = Math.max(lastTime + 16, now);
	        return setTimeout(function() { callback(lastTime = nextTime); }, nextTime - now);
	    };
	    W.cancelAnimationFrame = clearTimeout;
	}
}(jQuery));