Artifact on specific glyph - with geometry preprocessing enabled

[bitsauce]

Hi!

Thanks for this library, I've found it to be really useful!

I have this font here that appears to generate an msdf with an artifact in it, but only for the lower-case letter "g" and only the bold version of the font (BpReplayBold.otf).

msdfgen.exe msdf -font BpReplayBold.otf 103 -o g_bold.png -dimensions 1024 1024 -pxrange 128 -autoframe

(I generated it as 1024x1024 for demonstration purposes, but it gets this dark line on the lower part of the "g" on all scales)

I don't have too much insight into how font geometry preprocessing works in msdfgen, but I did check that the font render correctly when rendered in the Windows font preview (and we have used it in other game engines as well without issues).

Do you have an idea what may cause this issue?

Thanks!

[Chlumsky]

Yes, this is caused by an extremely sharp angle and is technically the "correct" behavior. Normally, the intersecting halfplanes of a corner diverge into different directions, but in scenarios like this, they continue on almost parallel to each other resulting in this type of artifact. I could maybe "fix" these cases by making the virtual edge continuations "bend" or otherwise change their trajectory.