<!DOCTYPE html>
<html>
<body>
<canvas/>
<script>
(function(bodyStyle) {
bodyStyle.mozUserSelect = 'none';
bodyStyle.webkitUserSelect = 'none'; var img = new Image();
var canvas = document.querySelector('canvas');
canvas.style.backgroundColor='transparent';
canvas.style.position = 'absolute'; img.addEventListener('load', function(e) {
var ctx;
var w = img.width,
h = img.height;
var offsetX = canvas.offsetLeft,
offsetY = canvas.offsetTop;
var mousedown = false; function layer(ctx) {
ctx.fillStyle = 'gray';
ctx.fillRect(0, 0, w, h);
} function eventDown(e){
e.preventDefault();
mousedown=true;
} function eventUp(e){
e.preventDefault();
mousedown=false;
} function eventMove(e){
e.preventDefault();
if(mousedown) {
if(e.changedTouches){
e=e.changedTouches[e.changedTouches.length-1];
}
var x = (e.clientX + document.body.scrollLeft || e.pageX) - offsetX || 0,
y = (e.clientY + document.body.scrollTop || e.pageY) - offsetY || 0;
with(ctx) {
beginPath()
arc(x, y, 20, 0, Math.PI * 2);
fill();
}
}
} canvas.width=w;
canvas.height=h;
canvas.style.backgroundImage='url('+img.src+')';
ctx=canvas.getContext('2d');
ctx.fillStyle='transparent';
ctx.fillRect(0, 0, w, h);
layer(ctx); ctx.globalCompositeOperation = 'destination-out'; canvas.addEventListener('touchstart', eventDown);
canvas.addEventListener('touchend', eventUp);
canvas.addEventListener('touchmove', eventMove);
canvas.addEventListener('mousedown', eventDown);
canvas.addEventListener('mouseup', eventUp);
canvas.addEventListener('mousemove', eventMove);
});
img.src = 'prize.jpg';
})(document.body.style);
</script>
</body>
</html>
<style>body{
margin:50px;
background-color:#2C3437;
}
.content{
display:inline-block;
width:350px;
height:239px;
margin-right:-4px;
}
.play{
cursor:pointer;
background-color:#060;
}
div>div{
display:block;
height:20px;
}
div>div>div{
width:16px;
height:16px;
background-color:#FFF;
display:inline-block;
float:right;
margin:2px;
}
</style>
<script>$(document).ready(function(){
animate();
$(".play").click(animate).mouseover(function(){
$(".play").css({"background-color":"#A55"});
}).mouseout(function(){
$(".play").css({"background-color":"#060"});
});
});
function animate(){
$('div>div>div').each(function(id){
$(this).css({
position: 'relative',
top: '-200px',
opacity: 0
});
var wait = Math.floor((Math.random()*3000)+1);
$(this).delay(wait).animate({
top: '0px',
opacity: 1
},1000);
});
}
</script> <!-- Generated by RunJS (Mon Mar 24 17:39:15 CST 2014) 1ms -->
这张图片是prize.jpg