liuzemin

雪花乱飘特效

<!--//

/*
Snow Effect Script
Created and submitted by Altan d.o.o. (snow@altan.hr, http://www.altan.hr/snow/index.html)
Permission granted to Dynamicdrive.com to feature script in archive
For full source code and installation instructions to this script, visit http://dynamicdrive.com
*/


//Configure below to change URL path to the snow image
var snowsrc="images/snow.gif"
// Configure below to change number of snow to render
var no = 20;

var ns4up = (document.layers) ? 1 : 0; // browser sniffer
var ie4up = (document.all) ? 1 : 0;

var dx, xp, yp;    // coordinate and position variables
var am, stx, sty; // amplitude and step variables
var i, doc_width = 800, doc_height = 600;

if (ns4up) {
    doc_width = self.innerWidth;
    doc_height = self.innerHeight;
}

dx = new Array();
xp = new Array();
yp = new Array();
am = new Array();
stx = new Array();
sty = new Array();

for (i = 0; i < no; ++ i) {
    dx[i] = 0;                        // set coordinate variables
    xp[i] = Math.random()*(doc_width-50); // set position variables
    yp[i] = Math.random()*doc_height;
    am[i] = Math.random()*20;         // set amplitude variables
    stx[i] = 0.02 + Math.random()/10; // set step variables
    sty[i] = 0.7 + Math.random();     // set step variables
    if (ns4up) {                      // set layers
      if (i == 0) {
        document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><a href=\"http://dynamicdrive.com/\"><img src='"+snowsrc+"' border=\"0\"></a></layer>");
      } else {
        document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src='"+snowsrc+"' border=\"0\"></layer>");
      }
    } else if (ie4up) {
      if (i == 0) {
        document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><a href=\"http://dynamicdrive.com\"><img src='"+snowsrc+"' border=\"0\"></a></div>");
      } else {
        document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc+"' border=\"0\"></div>");
      }
    }
}

function snowNS() { // Netscape main animation function
    for (i = 0; i < no; ++ i) { // iterate for every dot
      yp[i] += sty[i];
      if (yp[i] > doc_height-50) {
        xp[i] = Math.random()*(doc_width-am[i]-30);
        yp[i] = 0;
        stx[i] = 0.02 + Math.random()/10;
        sty[i] = 0.7 + Math.random();
        doc_width = self.innerWidth;
        doc_height = self.innerHeight;
      }
      dx[i] += stx[i];
      document.layers["dot"+i].top = yp[i];
      document.layers["dot"+i].left = xp[i] + am[i]*Math.sin(dx[i]);
    }
    setTimeout("snowNS()", 10);
}

function snowIE() { // IE main animation function
    for (i = 0; i < no; ++ i) { // iterate for every dot
      yp[i] += sty[i];
      if (yp[i] > doc_height-50) {
        xp[i] = Math.random()*(doc_width-am[i]-30);
        yp[i] = 0;
        stx[i] = 0.02 + Math.random()/10;
        sty[i] = 0.7 + Math.random();
        doc_width = document.body.clientWidth;
        doc_height = document.body.clientHeight;
      }
      dx[i] += stx[i];
      document.all["dot"+i].style.pixelTop = yp[i];
      document.all["dot"+i].style.pixelLeft = xp[i] + am[i]*Math.sin(dx[i]);
    }
    setTimeout("snowIE()", 10);
}

if (ns4up) {
    snowNS();
} else if (ie4up) {
    snowIE();
}
//-->

 

 

<HTML>
<HEAD>
<TITLE>JS雪花特效</TITLE>
<SCRIPT src="js/snow.js"></SCRIPT>
<style type="text/css">
<!--
body {
background-color: #FF9900;
}
-->
</style>
</HEAD>
<BODY>
</BODY>
</HTML>

    只要在JS文件中正确的指向图片路径,在测试网页中就能看到了.

posted on 2009-03-08 21:08  liuzemin  阅读(273)  评论(0)    收藏  举报