JS1k: The JavaScript code golfing competition

T=10;D="onmousedown";M="onmousemove";Z=16;w=c.width=h=c.height=200;m=Math;d=m.abs;r=m.random;l=4;c.setAttribute("style","position:absolute;top:0;left:0;width:100%;height:100%;");q=window;function s(b,f,j,g){b-=j;f-=g;return b*b+f*f}c[M]=function(b){e[0][0]=b.pageX/q.innerWidth*w;e[0][1]=b.pageY/q.innerHeight*h};q.setInterval(function(b,f,j,g,t,k){a.fillStyle="#"+(Z+120*(m.sin((new Date).getTime()/1e3)+1)<<Z).toString(Z);a.fillRect(0,0,w,h);for(b=0;b<w;b++)for(f=0;f<h;f++){for(i=j=k=0;i<l;i++){g=b;var n=f,o=e[i][0],p=e[i][1];g=m.min(2,T/(d(o-g)+d(p-n))+m.max(100/s(g,n,o-13,p-T),100/s(g,n,o+13,p-T)));g>k&&(t=i,k=g);j+=g}a.fillStyle="#"+e[t][4].toString(Z);0.9<j&&a.fillRect(b,f,1,1)}for(i=1;i<l;i++){b=e[i];b[0]+=b[2];b[1]+=b[3];if(0>b[0]||b[0]>w)b[2]*=-1;if(0>b[1]||b[1]>h)b[3]*=-1}},40);q[D]=function(b){b.stopPropagation();var f=0;if(1<b.which)for(f=0;f<l;f++)e[f][2]=T*r(),e[f][3]=T*r();else{e=[];for(f=0;f<l;f++)e[f]=[r()*w,r()*h,T*r(),T*r(),Z+240*r()<<Z]}return!1};q.onload=function(b){q[D](b);c[M](b)};

VD0xMDtEPSJvbm1vdXNlZG93biI7TT0ib25tb3VzZW1vdmUiO1o9MTY7dz1jLndpZHRoPWg9Yy5oZWlnaHQ9MjAwO209TWF0aDtkPW0uYWJzO3I9bS5yYW5kb207bD00O2Muc2V0QXR0cmlidXRlKCJzdHlsZSIsInBvc2l0aW9uOmFic29sdXRlO3RvcDowO2xlZnQ6MDt3aWR0aDoxMDAlO2hlaWdodDoxMDAlOyIpO3E9d2luZG93O2Z1bmN0aW9uIHMoYixmLGosZyl7Yi09ajtmLT1nO3JldHVybiBiKmIrZipmfWNbTV09ZnVuY3Rpb24oYil7ZVswXVswXT1iLnBhZ2VYL3EuaW5uZXJXaWR0aCp3O2VbMF1bMV09Yi5wYWdlWS9xLmlubmVySGVpZ2h0Kmh9O3Euc2V0SW50ZXJ2YWwoZnVuY3Rpb24oYixmLGosZyx0LGspe2EuZmlsbFN0eWxlPSIjIisoWisxMjAqKG0uc2luKChuZXcgRGF0ZSkuZ2V0VGltZSgpLzFlMykrMSk8PFopLnRvU3RyaW5nKFopO2EuZmlsbFJlY3QoMCwwLHcsaCk7Zm9yKGI9MDtiPHc7YisrKWZvcihmPTA7ZjxoO2YrKyl7Zm9yKGk9aj1rPTA7aTxsO2krKyl7Zz1iO3ZhciBuPWYsbz1lW2ldWzBdLHA9ZVtpXVsxXTtnPW0ubWluKDIsVC8oZChvLWcpK2QocC1uKSkrbS5tYXgoMTAwL3MoZyxuLG8tMTMscC1UKSwxMDAvcyhnLG4sbysxMyxwLVQpKSk7Zz5rJiYodD1pLGs9Zyk7ais9Z31hLmZpbGxTdHlsZT0iIyIrZVt0XVs0XS50b1N0cmluZyhaKTswLjk8aiYmYS5maWxsUmVjdChiLGYsMSwxKX1mb3IoaT0xO2k8bDtpKyspe2I9ZVtpXTtiWzBdKz1iWzJdO2JbMV0rPWJbM107aWYoMD5iWzBdfHxiWzBdPncpYlsyXSo9LTE7aWYoMD5iWzFdfHxiWzFdPmgpYlszXSo9LTF9fSw0MCk7cVtEXT1mdW5jdGlvbihiKXtiLnN0b3BQcm9wYWdhdGlvbigpO3ZhciBmPTA7aWYoMTxiLndoaWNoKWZvcihmPTA7ZjxsO2YrKyllW2ZdWzJdPVQqcigpLGVbZl1bM109VCpyKCk7ZWxzZXtlPVtdO2ZvcihmPTA7ZjxsO2YrKyllW2ZdPVtyKCkqdyxyKCkqaCxUKnIoKSxUKnIoKSxaKzI0MCpyKCk8PFpdfXJldHVybiExfTtxLm9ubG9hZD1mdW5jdGlvbihiKXtxW0RdKGIpO2NbTV0oYil9Ow==

w = c.width = 200;
h = c.height = 200;
m = Math;
d = m.abs;
r = m.random;
l = 4;
c.setAttribute("style","position:absolute;top:0;left:0;width:100%;height:100%;");
q = window;
e = [];

function sqDist(x1, y1, x2, y2) {
	var x = x1 - x2, y = y1 - y2;
	return x*x + y*y;
}

function getValue(hx, hy, x, y) {
	return m.min(2, 10 / (d(hx - x)+d(hy - y)) + m.max(100/sqDist(x,y,hx-13,hy-10), 100/sqDist(x,y,hx+13,hy-10)));
}

function draw() {
	var x,y,value,g,v,closest,max;
	a.fillStyle = "#"+((16+120*(m.sin((new Date().getTime())/900)+1))<<16).toString(16);
	a.fillRect(0,0,w,h);
	for(x=0;x<w;x++) {
		for(y=0;y<h;y++) {
			value = max = 0;
			for(i=0;i<l;i++) {
				v = getValue(e[i][0],e[i][1],x,y);
				if(v > max) {
					closest = i;
					max = v;
				}
				value += v;
			}
			a.fillStyle = "#"+e[closest][4].toString(16);
			if(value > 0.9) a.fillRect(x,y,1,1);
		}
	}
	for(i=1;i<l;i++) {
		g = e[i];
		g[0] += g[2];
		g[1] += g[3];
		if(g[0] < 0 || g[0] > w) g[2] *= -1;
		if(g[1] < 0 || g[1] > h) g[3] *= -1;
	}
}
c.onmousemove = function(v){
	e[0][0] = v.pageX / q.innerWidth * w;
	e[0][1] = v.pageY / q.innerHeight * h;
};
q.setInterval(draw, 40);
q.onmousedown = function(v) {
	v.stopPropagation();
	var b = v.which?v.which:v.button,i=0;
	if(b > 1) {
		for(i=0;i<l;i++) { 
			e[i][2] = r()*10; e[i][3] = r()*10; 
		}		
	} else {
		e = []; 
		for(i=0;i<l;i++) 
			e[i] = [r()*w,r()*h,r()*10,r()*10,(16+240*r())<<16];
	}
	return false;
}
q.onload = function(v) {q.onmousedown(v); c.onmousemove(v);}