Carl Worth [Thu, 5 Mar 2009 08:33:54 +0000 (00:33 -0800)]
Add simplistic button-press handling
Right now this is just toggling a white ring on and off at
each location. The significant bit here is that the calculations
between board-index positions and screen coordinates are now
correct. Thanks to Keith Packard for helping me think through
some of the math here.