JS1k, the yearly JS code golfing competition

JS1k: The JavaScript code golfing competition

2014 - Here be dragons!

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illusory cones

a common optical illusion

Author:
Jon Faviell
Twitter:
@
GitHub:
Facebook:
Google+:
+
Reddit:
/r/
Pouet:
Website: 
djfav.com
Compo:
classic
Demo link:
https://js1k.com/2014-dragons/demo/1959
Shortlink:
https://js1k.com/1959
Blog post:
please update here!
Bytes:
325
Chars:
325
Submission
var w,h,x=t=0,r=200;function f(){c.clearRect(0,0,w,h),c.save(),c.translate(w/2,h/2),c.rotate(t/Math.PI);for(i=1;i<20;i++)x=20*Math.sin(i/2),c.beginPath(),c.fillStyle=0!=i%2?"#000":"#fff",c.arc(x,0,r-10*i,0,2*Math.PI),c.fill();c.restore(),t+=0.5}onload=function(){c.width=w=innerWidth,c.height=h=innerHeight,setInterval(f,50)}
Description
a common optical illusion
Base64 encoded
dmFyIHcsaCx4PXQ9MCxyPTIwMDtmdW5jdGlvbiBmKCl7Yy5jbGVhclJlY3QoMCwwLHcsaCksYy5zYXZlKCksYy50cmFuc2xhdGUody8yLGgvMiksYy5yb3RhdGUodC9NYXRoLlBJKTtmb3IoaT0xO2k8MjA7aSsrKXg9MjAqTWF0aC5zaW4oaS8yKSxjLmJlZ2luUGF0aCgpLGMuZmlsbFN0eWxlPTAhPWklMj8iIzAwMCI6IiNmZmYiLGMuYXJjKHgsMCxyLTEwKmksMCwyKk1hdGguUEkpLGMuZmlsbCgpO2MucmVzdG9yZSgpLHQrPTAuNX1vbmxvYWQ9ZnVuY3Rpb24oKXtjLndpZHRoPXc9aW5uZXJXaWR0aCxjLmhlaWdodD1oPWlubmVySGVpZ2h0LHNldEludGVydmFsKGYsNTApfQ==
Original source
var w, h, x = t = 0, r = 200;
function f() {
  c.clearRect(0, 0, w, h);
  c.save();
  c.translate(w / 2, h / 2);
  c.rotate(t / Math.PI);
  for (i = 1; i < 20; i++) {
    x = Math.sin(i / 2) * 20;
    c.beginPath();
    if (i % 2 != 0) {
    c.fillStyle = "#000";
    c.arc(x, 0, r - (i * 10), 0, 2 * Math.PI);
    c.fill();
    }
    else {
    c.fillStyle = "#fff";
    c.arc(x, 0, r - (i * 10), 0, 2 * Math.PI);
    c.fill();
    }
  }
  c.restore();
  t += 0.5;
}
onload = function () {
  c.width = w = innerWidth;
  c.height = h = innerHeight;
  setInterval(f, 50);
};