RandPoly is a simple program provided as an example to new programmers on the NeXT machine. It is not intended as an example of graphics speed, and makes little attempt at drawing as fast as possible.
The basic idea is to draw polygons continuously, while allowing any other events to be handled. If Alpha is enabled, each polygon is drawn first into a bitmap, and then composited on the the screen using the SOVER compositing operation. This allows for the transparency you see at alpha values less than one (1.0 is opaque).
