Well let's see, there's probably something in the drawing co-

Four full-sized canvases laid atop each other?

(And I guess peeking at the code, they may be able to get rid of one of those Math.sqrts by using the distance-squared everywhere you need it instead of the distance. As a first pass there's probably other sqrts or trig that could be removed, but its hard to eyeball minified code)

I thought it was a very pretty sight, but it probably could be made a lot less harsh.