重力+碰撞运动 

 1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 2 <html xmlns="http://www.w3.org/1999/xhtml">
 3 <head>
 4 <style>
 5 #div1 {width:100px; height:100px; background:red; position:absolute;}
 6 </style>
 7 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 8 <title>无标题文档</title>
 9 <script>
10 var iSpeedX=1000;
11 var iSpeedY=0;
12 
13 function startMove()
14 {
15     setInterval(function (){
16         var oDiv=document.getElementById('div1');
17         
18         iSpeedY+=3;
19         
20         var l=oDiv.offsetLeft+iSpeedX;
21         var t=oDiv.offsetTop+iSpeedY;
22         
23         if(t>=document.documentElement.clientHeight-oDiv.offsetHeight)
24         {
25             iSpeedY*=-0.8;
26             iSpeedX*=0.8;
27             t=document.documentElement.clientHeight-oDiv.offsetHeight;
28         }
29         else if(t<=0)
30         {
31             iSpeedY*=-1;
32             iSpeedX*=0.8;
33             t=0;
34         }
35         
36         if(l>=document.documentElement.clientWidth-oDiv.offsetWidth)
37         {
38             iSpeedX*=-0.8;
39             l=document.documentElement.clientWidth-oDiv.offsetWidth;
40         }
41         else if(l<=0)
42         {
43             iSpeedX*=-0.8;
44             l=0;
45         }
46         
47         if(Math.abs(iSpeedX)<1)
48         {
49             iSpeedX=0;
50         }
51         
52         if(Math.abs(iSpeedY)<1)
53         {
54             iSpeedY=0;
55         }
56         
57         oDiv.style.left=l+'px';
58         oDiv.style.top=t+'px';
59         console.log("--"+iSpeedY)
60         document.title=iSpeedX;
61     }, 30);
62 }
63 </script>
64 </head>
65 
66 <body>
67 <input type="button" value="开始运动" onclick="startMove()" />
68 <div id="div1">
69 </div>
70 </body>
71 </html>

 

 
posted @ 2015-11-09 22:30  Evans.wang  阅读(179)  评论(0)    收藏  举报