On Sat, Apr 9, 2011 at 7:32 PM, Mathieu Bouchard <ma...@artengine.ca> wrote:
> On Sat, 9 Apr 2011, Peter Brinkmann wrote: > > By the way, there's a way to draw a circle using nothing but addition: >> http://en.wikipedia.org/wiki/Midpoint_circle_algorithm >> Implementing this in Pd is completely impractical, but it's fun to think >> about. >> > > It's not strictly the same thing, because by using sin and cos, you are > ensuring equal distance between points at infinite resolution, and you are > ensuring equal angles everywhere too. > > With the midpoint circle algorithm, instead, you are ensuring that all > points are one pixel apart, when using a limited resolution. The pixels are > considered one pixel apart when sharing an edge or corner. This is related > to http://en.wikipedia.org/wiki/Maximum_norm > > So, it depends on whether you're trying to draw something > continuous-looking on a pixel display. Sure, but in this case the goal was to draw a section of a circle in an array, and the midpoint algorithm would be a good choice if implementing it in Pd weren't so complex. Anyway, it doesn't really matter, I just like Bresenham-style algorithms. Cheers, Peter
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