"It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration."
- Edsger Dijkstra

GPAA explained
Monday, March 14, 2011 | Permalink

I've added an illustration for the GPAA technique with a little more explanation in the demo description.

The wide line is the geometric edge. The arrows show how the neighbor pixel is chosen. The dashed lines shows the value of line equation for that pixel, which is used to compute the coverage value.