## Faster than Bresenham’s Algorithm?

July 28, 2009

There’s always a number of graphics primitives you will be using in all kinds of projects. If you’re lucky, you’re working on a “real” platform that comes with a large number of graphics libraries that offer abstractions to the graphics primitives of the OS and, ultimately, to its hardware. However, it’s always good to know what’s involved in a particular graphics primitives and how to recode it yourself should you be in need to do so, either because you do not have a library to help you, or because it would contaminate your project badly to include a library only to draw, say, a line, within an image buffer.

Lines are something we do a lot. Perfectly horizontal or vertical lines have very simple algorithms. Arbitrary lines are a bit more complicated, that is, to get just right. This week, let us take a look at a few algorithms to draw lines. First, we’ll discuss a naïve algorithm using floating point. We’ll also have a look at Bresenham’s algorithm that uses only integer arithmetic. Finally, we’ll show that we can do better than Bresenham if we used fixed point arithmetic.

## Powers of Ten (so to speak)

June 29, 2009

I am not sure if you are old enough to remember the 1977 IBM movie Powers of Ten (trippy version, without narration) [also at the IMDB and wikipedia], but that’s a movie that sure put things in perspective. Thinking in terms of powers of ten helps me sort things out when I am considering a design problem. Thinking of the scale of a problem in terms of physical scale is a good way to assess its true importance for a project. Sometimes the problem is the one to solve, sometimes, it is not. It’s not because a problem is fun, enticing, or challenging, that it has to be solved optimally right away because, in the correct context, considering its true scale, it may not be as important as first thought.

Maybe comparing problems’ scales to powers of ten in the physical realm helps understanding where to put your efforts. So here are the different scales and what I think they should contain: