poly2tri is not stable

[bubnikv]

Guys,

just a note, that the poly2tri library is not stable and it will make the application crash randomly. We at the Slic3r PE team are using the old C glu tesselator code by SGI from a pure despair of not finding a free stable self-contained triangulator (apart from CGAL).

Here is the tesselator dug out from the glu library.
https://github.com/prusa3d/Slic3r/tree/master/src/glu-libtess

[tomasiser]

Hi Vojta!

Thanks for the issue. How often does it happen? Could it be a problem just with certain too complex fonts? We found out that certain fonts are too "weird" to be triangulated properly, but did not notice any problems with classic fonts.

[bubnikv]

It is sensitive to the input geometry, and it crashes with stack overflow or whatever. We use it for triangulating holes left after splitting an object with a plane, and it crashes a lot. For fonts it may be all right, but the very old C code by SGI is much more stable (and much better tested I suppose) For inspiration, this is a simple wrapper around glu tesselator. ExPolygon is just a contour with a vector of holes. https://github.com/prusa3d/Slic3r/blob/master/src/libslic3r/Tesselate.hpp https://github.com/prusa3d/Slic3r/blob/master/src/libslic3r/Tesselate.cpp

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On Mon, Apr 1, 2019 at 9:15 AM Tomáš Iser ***@***.***> wrote: Hi Vojta! Thanks for the issue. How often does it happen? Could it be a problem just with certain too complex fonts? We found out that certain fonts are too "weird" to be triangulated properly, but did not notice any problems with classic fonts. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#148 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFj5I2qzmNTp6UzAcF1z1eDYhUPyvl9Yks5vcbIggaJpZM4cU-s7> .