JS1k: The JavaScript code golfing competition

s='~e=Math.random,f=document.getElementById("c"),k=f.getContext("2d"),l=f.width=400,m=f.height=400;k.fillStyle="red";#n(a,b){~c=[];for(~d in a)c.push(a[d]*b);_c}#o(a,b){~c=a!,d=a%,g=a[2];a=a[3];~h=b!,i=b%,j=b[2];b=b[3];_[c*h-d*i-g*j-a*b,c*i+d*h+g*b-a*j,c*j-d*b+g*h+a*i,c*b+d*j-g*i+a*h]}'+
'#q(a,b){b=n([o(o(a%,[0,b!,b%,b[2]]),[a%!,-a%%,-a%[2],-a%[3]])%,o(o(a%,[0,b!,b%,b[2]]),[a%!,-a%%,-a%[2],-a%[3]])[2],o(o(a%,[0,b!,b%,b[2]]),[a%!,-a%%,-a%[2],-a%[3]])[3]],a!);a=a[2];~c=[];for(~d in b)c.push(b[d]+a[d]);_c}~r,s=[90,1,1,0],t=0;for(~u in s)t+=s[u]*s[u];r=n(s,1/Math.sqrt(t));~v,w=[[0.5,r,[0.5,0.5,0]],[0.5,r,[-0.5,0.5,0]],[0.5,r,[0,-0.366,0]],[0.5,r,v=[0,0.25,0.616]]];p=[];~x=0,y=r,z=[1,r,v];'+
    '#A(){k.clearRect(0,0,l,m);for(x in p){~a=q(z,p[x]),b=a[2]+2;k.fillRect((a!/b+1)*l/2,(a%/b+1)*m/2,4/b,4/b)}z%=o(z%,y);if(x<2222)p.push(v=q(w[Math.floor(e()*w.length)],v))}setInterval(A,0);';
function r(a,b){s=s.replace(a,b);};r(/#/g,'function ');r(/_/g,'return ');r(/~/g,'var ');r(/!/g,'[0]');r(/%/g,'[1]');eval(s);
​

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