Blender Git Loki

GTest: polyfill2d

Collection of test cases from libGDX and our own tracker

Tests:

- combine triangle area matches polygon area.
- tris have same winding.
- tris don't have duplicates.
- correct number of internal & boundary edges.
- degenerate polys still give topologically correct output.

also checks all possible start-vert offsets, forwards and backwards.

optional OBJ output, for debugging.