A sane person would have fixed the remaining oddities in the square tiling. But instead, I propagated the same horrible user interface to a mandala generator:
http://www.otoh.org/zwicky/Processing/easymandala/applet/index.html

Code re-use means that the keys tend to do similar sorts of stuff; 'a' will make it draw once and stop, 'd' will make it draw continuously and vary, 'g' clears the screen without changing other parameters, 'h' and mouse clicks give you all new combinations.