星系特效 

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8">
<title>星系</title>
<style>
body{margin:0;overflow:hidden}
div{padding:1px 5px;background:#333;position:absolute;z-index:2;color:#555;font-family:arial}
a{color:#ccf}
a:hover{color:red}
</style>
</head>
<body>
<div id="text"></div>
<canvas id="keleyi_com"></canvas>
<script type="text/javascript">
 window.onload = function () {
     C = Math.cos; 
     S = Math.sin; 
     U = 0; 
     w = window; 
     j = document; 
     d = j.getElementById("kele"+"yi_com"); 
     c = d.getContext("2d"); 
     W = d.width = w.innerWidth; 
     H = d.height = w.innerHeight; 
     c.fillRect(0, 0, W, H); 
     c.globalCompositeOperation = "lighter"; 
     c.lineWidth = 0.2; c.lineCap = "round"; 
     var bool = 0, t = 0; 
     d.onmousemove = function (e) {
          if (window.T) {
          if (D == 9) { D = Math.random() * 15; f(1); }
            clearTimeout(T);
        }
     X = e.pageX; 
     Y = e.pageY; 
     a = 0; 
     b = 0; 
     A = X, B = Y; 
     R = (e.pageX / W * 999 >> 0) / 999; 
     r = (e.pageY / H * 999 >> 0) / 999; 
     U = e.pageX / H * 360 >> 0; D = 9; 
     g = 360 * Math.PI / 180; 
     T = setInterval(f = function (e) {
     c.save(); 
     c.globalCompositeOperation = "source-over"; 
     if (e != 1) { c.fillStyle = "rgba(0,0,0,0.02)"; 
     c.fillRect(0, 0, W, H); 
    }
    c.restore(); i = 25; while (i--) {
    c.beginPath(); 
       if (D > 450 || bool) {
        if (!bool) { bool = 1; }
        if (D < 0.1) { bool = 0; }
            t -= g; D -= 0.1;
       }
       if (!bool) { t += g; D += 0.1; }
       q = (R / r - 1) * t; x = (R - r) * C(t) + D * C(q) + (A + (X - A) * (i / 25)) + (r - R); 
       y = (R - r) * S(t) - D * S(q) + (B + (Y - B) * (i / 25)); 
       if (a) { c.moveTo(a, b); c.lineTo(x, y) }
       c.strokeStyle = "hsla(" + (U % 360) + ",100%,50%,0.75)"; 
       c.stroke(); a = x; b = y;
       }
       U -= 0.5; A = X; B = Y;
     }, 16);
  }
    j.onkeydown = function (e) { a = b = 0; R += 0.05 }
    d.onmousemove({ pageX: 300, pageY: 290 })
  }
</script>
</body>
</html>

 

posted @ 2015-12-04 11:31  像风一样自由~~~  阅读(252)  评论(0)    收藏  举报