>>> TRY IN PHOSPHORUS: http://phosphorus.github.io/#107253589 <<< I'm trying out something new. Something like a hybrid between grid-based GOL and point-based GOL, while still sticking with conventional checking. It's performs well even for 480x360, but I don't think it's quite as fast as @TheLogFather's version. I'm not adept at making this optimized. I have checked and considered implementing hashlife, but that is far too complicated in Scratch without some sort of first-class data structure. Ah well, have fun seeing all the little doodads interact. Click around to draw cells.
