JS1k: The JavaScript code golfing competition

var D=document,V=D.getElementById('c'),C=V.getContext('2d'),W=120,N=5,X=V.width=V.height=N*W,L=.5,T,T0=0,M=Math,Mf=M.floor,Ma=M.abs,Ms=M.sin,Mc=M.cos,Mq=2*M.PI,E='createImageData',I=C[E](W,W),J=C[E](W,W),A=I.data,B=J.data,i,j,x,y
D.bgColor='#000'
function O(v,sz){return Ma(Mf(v[0]*sz[0]))%2==Ma(Mf(v[1]*sz[1]))%2?1:0}
function P(v,a){var c=Mc(a*Mq),s=Ms(a*Mq);return[c*v[0]-s*v[1],s*v[0]+c*v[1]]}
function Q(v){return 1-(v[0]*v[0]+v[1]*v[1])}
function R(k,a,b){return k*a+(1-k)*b}
function S(v,f){return[v[0]*f,v[1]*f]}
function f(x){return L*(1+Mc(T/x))}
function U(v){var ka=f(1),kb=f(3),kc=f(11),kd=f(13),s=Ms(T/2)
return O(S(P(v,R(kb,s*Q(v),1)),R(ka,v[0],1)),[R(kd,v[1]*50,.05),R(kc,v[0],v[1])*50])}
function $(b,p,q){for(j=0;j<4;j++)b[4*p+j]=255*q;b[4*p+3]=255}
function _(){T=(new Date().getTime()-T0)/1000
T0=T0||T*1000
for(i=0;i<W*W;i++){x=i%W;y=Mf(i/W),q=U([x/W-L,y/W-L])
$(A,i,q);$(B,i,1-q)}
for(i=0;i<N*N;i++)
C.putImageData(i%2?I:J,W*(i%N),W*Mf(i/N))
setTimeout(_,30)}
_()

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