一、弹性运动
运动原理：加速运动+减速运动+摩擦运动；
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
#div1{ width:100px; height:100px; background:red; position:absolute; left:0; top:50px;}
</style>
<script>
window.onload = function()
{
var oBtn = document.getElementById('btn1');
var oDiv = document.getElementById('div1');
oBtn.onclick = function()
{
startMove(oDiv, 300);
};
};
var iSpeed = 0;
var left = 0;
function startMove(obj, iTarget)
{
clearInterval(obj.timer);
obj.timer = setInterval(function(){
iSpeed += (iTarget - obj.offsetLeft)/5;
iSpeed *= 0.7;
left += iSpeed;
if(Math.abs(iSpeed)<1 && Math.abs(left-iTarget)<1){
clearInterval(obj.timer);
obj.style.left = iTarget + 'px';
}else{
obj.style.left = obj.offsetLeft + iSpeed + 'px';
}
}, 30);
}
</script>
</head>
<body>
<input id="btn1" type="button" value="运动" />
<div id="div1"></div>
<div style="width:1px; height:300px; background:black; position:absolute; top:0; left:300px; "></div>
</body>
</html>