动画性能优化－requestanimationframe、GPU等

 1 /* requestAnimationFrame.js
 2  * by zhangxinxu 2013-09-30
 3 */
 4 (function() {
 5     var lastTime = 0;
 6     var vendors = [‘webkit‘, ‘moz‘];
 7     for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
 8         window.requestAnimationFrame = window[vendors[x] + ‘RequestAnimationFrame‘];
 9         window.cancelAnimationFrame = window[vendors[x] + ‘CancelAnimationFrame‘] ||    // name has changed in Webkit
10                                       window[vendors[x] + ‘CancelRequestAnimationFrame‘];
11     }
12 
13     if (!window.requestAnimationFrame) {
14         window.requestAnimationFrame = function(callback) {
15             var currTime = new Date().getTime();
16             var timeToCall = Math.max(0, 16.7 - (currTime - lastTime));
17             var id = window.setTimeout(function() {
18                 callback(currTime + timeToCall);
19             }, timeToCall);
20             lastTime = currTime + timeToCall;
21             return id;
22         };
23     }
24     if (!window.cancelAnimationFrame) {
25         window.cancelAnimationFrame = function(id) {
26             clearTimeout(id);
27         };
28     }
29 }());

newImgObjs[i] = new Image();
newImgObjs[i].src = animationImgs[i];

newImgObjs[i].onload = function() {
    loadeds++;
    if (loadeds == newImgObjs.length) {
        self.barObj.completeWelcomePromise.resolve();
        console.log(‘图片资源已经加载完成‘);
     }
};

newImgObjs[i].onerror = function() {
    loadeds++;
    if (loadeds == newImgObjs.length) {
        self.barObj.completeWelcomePromise.resolve();
        console.log(‘图片资源已经加载完成‘);
    }
};    

$audio[0].src = imgPath;
$audio.on(‘canplaythrough‘, function() {
    loadeds++;
    if (loadeds == (newImgObjs.length + 1)) {
        self.barObj.completePromise.resolve();
        console.log(‘音频资源已经加载完成‘);
    }
});

$audio[0].onerror = function(e) {
    loadeds++;
    if (loadeds == (newImgObjs.length + 1)) {
        self.barObj.completePromise.resolve();
        console.log(‘音频资源已经加载完成‘);
    }
};

// 资源处理：预加载、监控加载完成、渲染
$.when(self.cmsInfoPromise, self.goodsInfoPromise, self.barObj.completeWelcomePromise)
    .done(function() {
        // 进度条动效
        self.barAnimation();
        self.handleResource();
        self.renderStores();
     });