This new quad-filling engine corrects a bug with concave triangles, by instead of using angles, it tests if the concave point is in an imaginary triangle made by 3 of the points. It also corrects the intersection calculating.
So far the quad-filler for opaque quads can probably fill any quadrilateral, and the translucent quad-filler can fill all convex quads (apparently) and all self-intersecting quads. Later I need a way of filling concave quads without overlapping lines. NOTICE: I will stop working on this for a while. For now the work will be done here: https://scratch.mit.edu/projects/71313304/
