JS1k: The JavaScript code golfing competition

var P=screen,w=P.width,h=P.height,lT=24,uT=0,dS=2,e=Math,n=e.random,gO=0,v="rgba(99,99,99,.5)";cx=-1;cy=-1;raio=2*e.PI;u=[cB()];c.width=w;c.height=h;function cB(){dS*=1.1;var b={r:20,s:dS};b.x=n()*w;b.y=n()*h;return b}function xy(b){cx=b.pageX-b.target.offsetLeft;cy=b.pageY-b.target.offsetTop}function R(b,d){var f=d.y>=b.y&&d.y<=b.h;return d.x>=b.x&&d.x<=b.w&&f}
function exe(){for(var b=u.length-1;0<=b;b--){var d=u[b],f=1,i=1,g=d.r/2;ar={x:d.x-g,w:d.x+g,y:d.y-g,h:d.y+g};if(R(ar,{x:cx,y:cy})){gO=1;break}d.x>cx&&(f=-1);d.y>cy&&(i=-1);-1<cx&&-1<cy&&(d.x+=f*d.s,d.y+=i*d.s)}-1<cx&&-1<cy&&(uT+=lT,5E3<=uT&&(uT=0,u.push(cB())))}function paint(){a.fillStyle="white";a.fillRect(0,0,w,h);for(var b=u.length-1;0<=b;b--){var d=u[b];a.fillStyle=v;a.beginPath();a.arc(d.x,d.y,d.r,0,raio,!0);a.fill()}a.fillStyle="black";a.font="17px arial";a.fillText(u.length,20,20)}
function l(){gO?confirm("Again?")&&location.reload():(exe(),paint(),setTimeout("l()",lT))}l();c.onmousemove=function(b){xy(b)};c.onmouseout=function(){cy=cx=-1};

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

Original source not submitted