requestAnimationFrame

向下兼容

window.requestAnimationFrame=window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    window.msRequestAnimationFrame ||
    window.oRequestAnimationFrame ||
    function( callback ){
        //为了使setTimteout的尽可能的接近每秒60帧的效果
        window.setTimeout(callback,1000/60);
    }
 
window.cancelAnimationFrame=window.cancelAnimationFrame ||
    Window.webkitCancelAnimationFrame ||
    window.mozCancelAnimationFrame ||
    window.msCancelAnimationFrame ||
    window.oCancelAnimationFrame ||
    function( id ){
        //为了使setTimteout的尽可能的接近每秒60帧的效果
        window.clearTimeout( id );
    }