How to do tessellation?

[jwwalker]

Suppose I need to do some 2D tessellation (i.e., take a planar polygon that may not be convex and may have holes, and break it into triangles). Up to now, I've done that using gluNewTess and friends. If I'm getting rid of OpenGL and leaving all GPU access up to Filament, how would you suggest I do tessellation? Assuming that this capability is not hidden in Filament, can anyone suggest open-source C++ software, hopefully with a fairly liberal license, that can do it on the CPU?

[romainguy]

gluNewTess is software based anyway. You should look for libraries that implement Delaunay triangulation. Maybe OpenSubdiv can do this as well?

[kpeeters]

Earcut does a pretty reasonable job, and is just a single header. See https://github.com/mapbox/earcut.hpp.

[jwwalker]

I tried Earcut, and it works for simple cases, but in complex cases it does not use the even-odd rule for inside vs. outside that I got with glu.

[prideout]

If you need even-odd support, maybe look at https://github.com/memononen/libtess2, written by the author of nanovg.

[jwwalker]

Thanks for the ideas, folks. I think what I'll do is use the glu tessellation code from Mesa, which should maximize compatibility.