JS1k: The JavaScript code golfing competition

A=800;function i(a,b){return j.pow(-1,j.floor(a/b))}function D(s){c.strokeStyle=s}function n(a,b,g){e=o(b);$=u(b),f=o(a);x=u(a);for(h=[],d=0;d<8;++d){q=i(d+1,2),r=i(d,4),v=i(d,2),w=v*f-r*$*x+q*x*e-4;h.push([400+g*(q*$+r*e)/w,400+g*(v*x+r*$*f-q*e*f)/w])}c.beginPath();for(d=0;d<17;++d)c.lineTo.apply(c,h["01537123045674260"[d]]);c.stroke()}function s(a,b,g){for(B=o(b+a)/15,C=0;C<4;++C){k=i(C,1);n(a+i(C,2)*B,b+k*B,g);n(a+k*B,b,g);n(a,b+k*B,g)}}k=document,x=k.body.style;x.textAlign="center";x.background="#57a";k=k.getElementById("c");k.width=k.height=A;c=k.getContext("2d"),l=0,y=0,m=0,z=0,j=Math,t=j.random,o=j.sin,u=j.cos;window.setInterval(function(){c.clearRect(0,0,A,A);a=(t()-0.5)/20;if(t()>0.97)y=a;if(t()>0.97)z=a;l+=y;m+=z;D("#89b");for(a=1;a<30;++a)for(b=1;b<30;++b)c.strokeRect(a*25,b*25,25,25);D("#dde");c.strokeRect(37,37,725,725);s(m,l,200);D("#f70");s(m,l,400);D("#fff");s(m,l,A)},40)

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

var win = window;
win.onload = function() {
   var doc = document;
   var style = document.body.style;
   style.textAlign = "center";
   style.background = "#57a";
   
   
   var canvas = doc.getElementById('c');
   canvas.width = canvas.height = 800;
   var context = canvas.getContext('2d');

   var phi = 0;
   var dphi = 0;
   var theta = 0;
   var dtheta = 0;   
      
   
   var m = Math;
   var random = m.random;
   var sin = m.sin;
   var cos = m.cos;
   
   
   function recurrence(index, width) {
      return m.pow(-1, m.floor(index / width));
   }   

   function drawCube(theta, phi, kC) {
      var sPhi = sin(phi);
      var cPhi = cos(phi);
      var sTheta = sin(theta);
      var cTheta = cos(theta);
       
      var kA = 400;
      var kB = 25 / 6;

      var points = new Array();
      for(var i = 0; i < 8; ++i) {
         var rA = recurrence(i + 1, 2);
         var rB = recurrence(i, 4);
         var rC = recurrence(i, 2);
         
         var w = rC * sTheta - rB * cPhi * cTheta + rA * cTheta * sPhi - kB;
         points.push([kA + kC * (rA * cPhi + rB * sPhi) / w,
            kA + kC * (rC * cTheta + rB * cPhi * sTheta - rA * sPhi * sTheta) / w]);
      }

      context.beginPath();
      var path = "01537123045674260";
      for (var i = 0; i < 17; ++i) {
         var index = path[i];
         context.lineTo.apply(context, points[index]);
      }
      context.stroke(); 
   }
   
   function drawCubes(theta, phi, kC) {
      var rA = sin(phi + theta) * kC / 24000;
      
      for(var i = 0; i < 4; ++i) {
         var rB = recurrence(i, 2);
         var rC = recurrence(i, 1);
         
         //setStrokeStyle("#fdd");
         drawCube(theta + rB * rA, phi + rC * rA, kC);
         
         //setStrokeStyle("#d77");
         drawCube(theta + rC * rA, phi, kC);
         
         //setStrokeStyle("#fff");
         drawCube(theta, phi + rC * rA, kC);         
      }
   }
   
   function drawBackground() {
      context.strokeStyle = "#89b";
      for(var i = 1; i < 31; ++i)
         for(var j = 1; j < 31; ++j)
            context.strokeRect(i * 25, j * 25, 25, 25);

      context.strokeStyle ="#dde";
      context.strokeRect(37, 37, 725, 725);
   }

   win.setInterval(function() {
      context.clearRect(0, 0, 800, 800);
      
      var newDelta = (random() - 0.5) / 20;
      if(random() > 0.97)
         dphi = newDelta;
      if(random() > 0.97)
         dtheta = newDelta;
      
      phi += dphi;
      theta += dtheta;
      
      drawBackground();
      
      drawCubes(theta, phi, 200); 
      context.strokeStyle ="#f70"
      drawCubes(theta, phi, 400);
      context.strokeStyle ="#fff"
      drawCubes(theta, phi, 800);
   }, 40);
};