/**
 * Created by Administrator on 2017/7/12.
 */

var lastTime = 0;
var vendors = ['webkit', 'moz'];
for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
    window.requestAnimationFrame = window[vendors[x] + 'RequestAnimationFrame'];
    window.cancelAnimationFrame = window[vendors[x] + 'CancelAnimationFrame'] ||    // name has changed in Webkit
      window[vendors[x] + 'CancelRequestAnimationFrame'];
}

if (!window.requestAnimationFrame) {
    window.requestAnimationFrame = function(callback) {
        var currTime = new Date().getTime();
        var timeToCall = Math.max(0, 16.7 - (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);
    };
}
