Re: Bresham's Algorithms

> Date: Sat, 19 Jun 1999 09:38:26 -0700
> From: Mike Romine <mromine@...>
> Subject: Bresham's Algorithms
>
> What are Bresham's Algorithms, and where can I find info on them?

Actually it is spelled, Bresenham. It is an algorithm originaly
developed for determining which dots to display on a CRT to make the
best straight line. Its most important feature is that it works with
just integer arithmetic, and only requires divide by 2, which is a
simple shift. That made it possible to implement in hardware for very
early graphic devices.

you can find the details in most grphics textbooks, I know it is in
FUNDAMENTALS OF INTERACTIVE COMPUTER GRAPHICS by Foley and Van Dam

It is of course also usefull in determining the step rates for making
step motors mill nice straight lines. It also doesnt give round-off
errors which you can get with the more obvious ways of generating lines.

It is a very clever routine, and will require a few minutes of study to
understand, but its very easy to program.

ron