I'm writing a paper about a plotter (I use a Prusa i3 with a custom "extruder" aka pen). And I'm supposed to write about the algorithms I/the plotter use(s). I tried reverse engineering, but since I'm not very experienced with this technique I wasn't successful. So I'm looking for the algorithm that marlinMarlin uses for it'sits G2/G3 commands.
Copy edited (e.g. ref. <http://reprap.org/wiki/Marlin>). Added some context. (its = possessive, it's = "it is" or "it has". See for example <http://www.wikihow.com/Use-Its-and-It%27s>.)