Source for demo by Andreas Köberle. See also description.
function j(d){b.clearRect(0,0,f,f);g[0].value=d.clientX||g[0].value;g[1].value=d.clientY||g[1].value;for(a=4;a--;)h[a]=g[a].value;var e=h[0]/10;d=s-e;var m=d/e,n=0,t=h[1]/10;e=h[2]/2+e;var o=h[3]*2,k,p;for(a=o;a--;){var c=t*n,q=d*Math.sin(c)+e*Math.sin(c*m)+l;c=d*Math.cos(c)-e*Math.cos(c*m)+l;n+=Math.PI*4/o;if(k){b.strokeStyle="hsl("+(r+a%85)+", 80%, 20%)";b.beginPath();b.moveTo(k,p);b.lineTo(q,c);b.closePath();b.stroke()}k=q;p=c}}for(a=4;a--;)document.body.innerHTML+='<input type="range" value="500"" max="1000" style="display:block" onchange="j({})">';
var i=document.getElementById("c"),b=i.getContext("2d"),f=1E3,l=f/2,s=l-100,r=0,a,g=document.getElementsByTagName("input"),h=[];i.width=f;i.height=f;b.globalAlpha=0.3;i.onclick=function(){r=Math.random()*256;j({})};i.onmousemove=j;j({})