css3让div随鼠标移动而抖动起来

最近发现一个网站，感觉用户体验不错，特别是一些背景图片随着鼠标的移动的反向的移动，感觉跟不错，于是就试着写了个小demo模仿一下

https://www.kennedyandoswald.com/#!/failure-intro-a-poem

	

	

	


<script type="text/javascript">
var items = document.getElementsByClassName("layer");
document.addEventListener('mousemove', function (evt){
	var x = evt.clientX;
	var y = evt.clientY;
	//console.log(x);
	var winWidth = window.innerWidth;
	var winHeight = window.innerHeight;
	var halfWidth = winWidth / 2;
	var halfHeight = winHeight / 2;

	var rx = x - halfWidth;
	var ry = halfHeight - y;
	var length = items.length;
	var max = 30;
	for (var i = 0 ; i < length ; i++) {
		 var dx = (items[i].getBoundingClientRect().width/max)*(rx / -halfWidth);
		var dy = (items[i].getBoundingClientRect().height/max)*(ry / halfHeight); 
		items[i].style['transform'] = items[i].style['-webkit-transform'] = 'translate('+dx+'px,'+dy+'px)';
	}
	 
}, false);

</script>

说明一下分别拿到每个p的长度和宽度，通过比例算出相对于窗口的合适的偏移量，max是每个p左右偏移最多不超过的值

效果展示