[PD] Graph a circle arc in an array?

[Mathieu Bouchard]

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.

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| Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC