<!DOCTYPE html>
<html xmlns="http:///1999/xhtml" lang="en">
<head>
<title>star</title>
<script type="text/javascript">
= function () {
C = ; // cache Math objects
S = ;
U = 0;
w = window;
j = document;
d = ("c");
c = ("2d");
W = = ;
H = = ;
(0, 0, W, H); // resize <canvas> and draw black rect (default)
= "lighter"; // switch to additive color application
= 0.2;
= "round";
var bool = 0,
t = 0; // theta
= function (e) {
if() {
if(D==9) { D=()*15; f(1); }
clearTimeout(T);
}
X = ; // grab mouse pixel coords
Y = ;
a=0; // previous
b=0; // previous
A = X, // original
B = Y; // original
R=(/W * 999>>0)/999;
r=(/H * 999>>0)/999;
U=/H * 360 >>0;
D=9;
g = 360 * / 180;
T = setInterval(f = function (e) { // start looping spectrum
();
= "source-over"; // switch to additive color application
if(e!=1) {
= "rgba(0,0,0,0.02)";
(0, 0, W, H); // resize <canvas> and draw black rect (default)
}
();
i = 25; while(i --) {
();
if(D > 450 || bool) { // decrease diameter
if(!bool) { // has hit maximum
bool = 1;
}
if(D < 0.1) { // has hit minimum
bool = 0;
}
t -= g; // decrease theta
D -= 0.1; // decrease size
}
if(!bool) {
t += g; // increase theta
D += 0.1; // increase size
}
q = (R / r - 1) * t; // create hypotrochoid from current mouse position, and setup variables (see: /wiki/Hypotrochoid)
x = (R - r) * C(t) + D * C(q) + (A + (X - A) * (i / 25)) + (r - R); // center on xy coords
y = (R - r) * S(t) - D * S(q) + (B + (Y - B) * (i / 25));
if (a) { // draw once two points are set
(a, b);
(x, y)
}
= "hsla(" + (U % 360) + ",100%,50%,0.75)"; // draw rainbow hypotrochoid
();
a = x; // set previous
b = y; // set previous
}
U -= 0.5; // increment hue
A = X; // set original
B = Y; // set original
}, 16);
}
= function(e) { a=b=0; R += 0.05 }
({pageX:300, pageY:290})
}
</script>
</head>
<body style="margin:0px;padding:0px;width:100%;height:100%;overflow:hidden;">
<canvas ></canvas>
</body>
</html>
