I'm trying to implement a simple and straightforward concave polygon creator that extract the outline of a polygon from a sprite image.
So my base image is a transparent png where the 'solid' pixel describe the shape of the polygon I'm trying to find.
I've coded some stuff to find the first non-transparent pixel and then walk all around the 'solid' pixel shape to extract relevant polygon points.
For now I create a polygon where all outline pixels are points, and then I (try to) simplify these polygon points to a relevant polygon where all lines are expressed by only 2 points.
Actually the code I have is quite 'working' but I'm interested if there is a well known algorithm for this kind of stuff.
I'm only interested by the external shape (no matters whether or not it is a weakly simple polygon)