As an aside, I always think it's such a shame that no one seems to mention Bresenham's updated, and quicker, run-length slice line algorithm.
EDIT: Was it ever patented? Might be why people didn't use it.
EDIT2: I googled it, couldn't find any patents (except for other patents mentioning Bresenham's algorithm). However, the Run-Slice algorithm was published in 85, so it hasn't had as much time to become famous. Also, I found this article describing a newer algorithm from 1999 which looks pretty interesting too:
> Nowadays, most of research papers suggest improvements of the DDA method that was first presented by J. Bresenham. This paper proposes a new algorithm based on a careful analysis of the line segments’ properties some of them previously unused.