I see no net gain in implementing or in using subpar nonreal-world-tested libraries just to do so in Rust.
They do not. What they solve is almost a toy problem compared to the size, scope and breadth of these libraries.
Just because some project is implemented in Rust does not make it comparable never mind superior by default.
There is a world out there and it is not homogeneous format and standards-compliant Latin fonts in English LTR text in linear disposition with some generic rectangular subpixel rendering on a regular rectangular grid.
I warmly welcome you to browse closed issues of FreeType [1] and also the closed issues of HarfBuzz [2]. If you feel inspired please do also look into mailing lists and discussion pages related to the development, building, tracking and patching of packages of these projects in any of the numerous places it is used.
The only argument Rust people have is in relation WASM but if you insist in targeting WASM why not fork FreeType, strip it to the strict subset of features your application needs and target it?
Why do it in the first place? Why reinvent the wheel?
As such I will restate my view: I see no gain in using any of these subpar libraries.
[1] https://gitlab.freedesktop.org/freetype/freetype/-/issues/?s...
[2] https://github.com/harfbuzz/harfbuzz/issues?q=is%3Aclosed
Although Typst uses pixglyph for rendering, it does support BiDi, complex script shaping, etc. For shaping, we use rustybuzz, which is pretty much a 1-1 port of harfbuzz to Rust. Although we would have gladly used harfbuzz, linking C and Rust in WASM is unfortunately not really possible. So we went for the practical choice of helping finish this port and using it.
As someone who studied typography and worked in that field professionally I understand the complexity of these subjects.
If you re-read my question it was about rasterisers. I.e. something that takes a bunch of lines, quadrics and cubics and draws a filled shape.
Everything else you read between the lines of my question but it wasn't there.
