Use ttf-parser for font parsing

[notgull]

I see that this crate uses its own code for TTF parsing. Is there a reason why ttf-parser isn't used here? It has no dependencies and is written in exclusively safe code.

[dfrg]

The primary value proposition of swash is support for hinting which is not possible to implement on top of ttf-parser without significant architectural changes to that crate.

[Maximkaaa]

I don't know much about how fonts work, but it seems that rustybuzz implement hinting even though they use ttf-parser for font loading. Or is it related to performance considerations?

[dfrg]

Rustybuzz implements shaping. AFAIK swash is the only rust library with full support for hinting.

[Maximkaaa]

Yeah, sorry, I completely misunderstood things. The more I understand about text rendering the more I understand that I don't understand more than I understand...

The source of my confusion was that I saw a reference to ttf-parser HintDevice and thought they use it (though they clearly don't since they don't do rasterizing).

[dfrg]

Yes, text rendering is a very deep rabbit hole :)