contrast_renderer VS glyphy

This is true, but there is a lot more to the story. For one, WebGPU does not (yet) support mesh shaders, though it may later as an extension. For two, consider a glyph such as "o" that has two contours. Real triangulation generates a mesh that only generates triangles between the outer and inner contours, and mesh shaders aren't good at that. There are techniques (cover and stencil) that draw twice, incrementing and decrementing a winding number stored in the stencil buffer (see contrast renderer[1] for a clean modern implementation), but it does require nontrivial tracking on the CPU side, and can result in lots of draw calls to switch between the cover and stencil stages unless sophisticated batching is done.

Compute shaders avoid all these problems and work on WebGPU 1.0 today.

[1]: https://github.com/Lichtso/contrast_renderer

Thanks!

You can also checkout the "feature/ui" branch in GIT [1] to get the UI framework prototype.

[1]: https://github.com/Lichtso/contrast_renderer/tree/feature/ui

harfbuzz creator made https://github.com/behdad/glyphy/ which i integrated into GTK a while back (but we don't ship currently, because we still do the bitmap stuff).

the bitmap stuff still has major drawbacks though, like maintaining grid alignments and pixel boundaries where as this stuff (mostly) goes away using glyphy.

still work to be done around hinting though (hence not merged).

You can approximate the Bézier curves with circular arcs and store those in the "SDF" instead. https://github.com/behdad/glyphy

> The only issue with it is that font rendering looks horrific, but that might just be my machine.

This is because GTK4 enables pixel/scaling-independent fractional vertical positioning, even with hinting enabled. There's a long (somewhat ongoing) discussion at https://gitlab.gnome.org/GNOME/gtk/-/issues/3787, though I haven't followed the last few months of discussion.

Even though GTK4 aims to achieve scale-independent layout, the 4 horizontal/vertical positions still produce a bit of judder, and fonts do not scale smoothly (even with bilinear interpolation) with hinting enabled, and (unless fixed) there are rendering issues due to failing to clear the texture atlas properly: https://gitlab.gnome.org/GNOME/gtk/-/issues/4322

Interestingly there's a proposal to switch GTK4 fonts to SDF-style rendering. This is somewhat like what Qt Quick 2 implemented already (and KDE turns off and reverts to FreeType rendering, to make QML apps mimic Qt Widgets font rendering more): https://blogs.gnome.org/chergert/2022/03/20/rendering-text-w... However, I looked at https://github.com/behdad/glyphy and it seems to implement vector-based SDFs, instead of earlier texture-based SDF/MSDFs used by Valve games and Qt Quick.