Some fonts fail to mesh glyphs

[ZeunO8]

Hi, love your library. Using it in my engine Zeungine and even have the created glyphs working with my Physics system, such that I can interact with them in a world.

I've found some fonts fail to render glyphs. Specifically, when creating mesh glyphs for the string "Zeungine", it fails on the "e"

The failing fonts are

Source Code Pro (Regular) - https://fonts.google.com/share?selection.family=Source+Code+Pro:ital,wght@0,200..900;1,200..900

ttf_glyph2mesh3d fails with code 9

Roboto (Regular) - https://fonts.google.com/share?selection.family=Roboto:ital,wght@0,100..900;1,100..900

A font that works fine is one I found in a ttf repository - "Paul" - https://www.fontspace.com/paul-font-f22964

One that works from Google Fonts is https://fonts.google.com/share?selection.family=Cal+Sans

Are there any settings I can tweak to try get glyph creation working?

[ZeunO8]

Some screenshots of working code

[fetisov]

Hello. Thanks for the message. Screenshots of the working code look very attractive!
I examined the Source Code Pro font and confirmed that it contains glyphs that the library cannot tessellate. The final statistics are as follows: 17 files contain 20608 glyphs, of which 9% of glyphs cannot be tessellated. In all cases, this is due to self-intersection of contours. Unfortunately, this is a known limitation of the library. This is described in the author's article https://habr.com/ru/articles/501268.
Perhaps in future versions the library will take this type of contour defects into account.