js实现宇宙星空背景效果的方法

前端技术 2023/09/07 JavaScript

本文实例讲述了js实现宇宙星空背景效果的方法。分享给大家供大家参考。具体实现方法如下：

复制代码 代码如下:

<!DOCTYPE html PUBLIC \"-//W3C//h2D XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/h2D/xhtml1-transitional.h2d\">
<html xmlns=\"http://www.w3.org/1999/xhtml\">
<head>
<TITLE>宇宙星空背景效果，Js特效</TITLE>
<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" />
<style type=\"text/css\">
.star {
position:absolute;
layer-background-color:white;
visibility:visible;
top:-50px;
width:50px;
height:50px;
font-size:1px;
background-color:white;
}
.60pt{font-size:60pt;color:#ff66cc;}
</style>
<SCRIPT LANGUAGE=\"JavaScript\">
<!--
var starnum = 75; // 星星的数目
var isNS = (document.layers);
var _all = (isNS)? \'\' : \'all.\';
var _style = (isNS) ? \'\' : \'.style\';
var xoffset, yoffset, w_x, w_y, tmpx, tmpy, scrlx, scrly;
function getstartpos(obj) {  //定义星星移动的起始位置
obj.deltay = Math.floor(Math.random() * 12);    //用随机函数决定
obj.deltax = Math.floor(Math.random() * 12);
obj.xdir = (Math.floor(Math.random() * 2) == 1) ? \'+\' : \'-\';
obj.ydir = (Math.floor(Math.random() * 2) == 1) ? \'+\' : \'-\';
obj.counter = 1;
if (isNS) {
obj.clip.width = 1;
obj.clip.height = 1;
obj.moveTo(xoffset+pageXOffset, yoffset+pageYOffset);
} else {
obj.width = 1;
obj.height = 1;
obj.pixelTop = yoffset+document.body.scrollTop;
obj.pixelLeft = xoffset+document.body.scrollLeft;
   }
}
function movestar(starN)   //移动星星的位置
{
tmpx = starN.deltax*starN.counter+starN.counter;
tmpy = starN.deltay*starN.counter+starN.counter;
if (isNS) {
starN.clip.width = starN.counter / 3;
starN.clip.height = starN.counter / 3;
scrlx = pageXOffset;
scrly = pageYOffset;
if ((starN.left+tmpx >= w_x+scrlx) || (starN.top+tmpy >= w_y+scrly) || (starN.left-tmpx <= scrlx) || (starN.top-tmpy <= scrly)) {
getstartpos(starN);
} else {
eval(\'starN.moveBy(\'+starN.xdir+tmpx+\', \'+starN.ydir+tmpy+\')\');
   }
} else {
starN.width = starN.counter/3;
starN.height = starN.counter/3;
scrlx = document.body.scrollLeft;
scrly = document.body.scrollTop;
if ((starN.pixelLeft+tmpx >= w_x+scrlx)||(starN.pixelTop+tmpy >= w_y+scrly) || (starN.pixelLeft-tmpx <= scrlx)||(starN.pixelTop-tmpy <= scrly)) {
getstartpos(starN);
} else {
eval(\'starN.pixelTop\'+starN.ydir+\'=tmpy\');
eval(\'starN.pixelLeft\'+starN.xdir+\'=tmpx\');
   }
}
starN.counter++;
}
function animate() //让所有的星星动起来
{
for(i=1; i <= starnum; i++) {
movestar(eval(\'star\'+i));
}
setTimeout(\'animate()\', 100);
}
 
function findwindowparams() {  //定义星星移动的起始位置
w_x = (isNS) ? window.innerWidth : document.body.clientWidth;
w_y = (isNS) ? window.innerHeight : document.body.clientHeight;
xoffset = w_x / 2;
yoffset = w_y / 2;
for (i = 1; i <= starnum; i++) {
getstartpos(eval(\'star\'+i));
   }
}
function resizeNS() {
setTimeout(\'document.location.reload()\', 400);
}
(isNS) ? window.onresize = resizeNS : window.onresize = findwindowparams;
window.onload = new Function(\"findwindowparams(); animate();\");
-->
</script>
</HEAD>
<BODY>
<body  bgcolor=#999999>
<SCRIPT LANGUAGE=\"JavaScript\">
<!--
for (i = 1; i <= starnum; i++) { //给星星定义层
document.writeln(\'<div id=\"star\'+i+\'\" class=\"star\"></div>\');
eval(\'var star\'+i+\'=document.\'+_all+\'star\'+i+_style);
}
-->
</script>
<p><center>
<font class=60pt><br>飞翔在<br>宇宙的星空中<br></font>
</center><p>
</body>
</html>

运行效果如下图所示：

希望本文所述对大家的javascript程序设计有所帮助。

本文地址：https://www.stayed.cn/item/19720

转载请注明出处。

本站部分内容来源于网络,如侵犯到您的权益,请 联系我

我的博客

人生若只如初见，何事秋风悲画扇。

我的标签

随笔档案