web动画的方式 aa3e requestAnimationFrame

requestAnimationFrame > setTimeout > setInterval

setTimeout

100/60

我们在实现运动时，从性能与兼容性两方面考虑，常常会如下声明：

var lastTime = 0,
nextFrame = window.requestAnimationFrame       ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame    ||
window.msRequestAnimationFrame     ||
function(callback) {
var currTime = + new Date,
delay = Math.max(1000/60, 1000/60 - (currTime - lastTime));
lastTime = currTime + delay;
return setTimeout(callback, delay);
},
cancelFrame = window.cancelAnimationFrame               ||
window.webkitCancelAnimationFrame         ||
window.webkitCancelRequestAnimationFrame  ||
window.mozCancelRequestAnimationFrame     ||
window.msCancelRequestAnimationFrame      ||
clearTimeout;