glyphy

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

> some software have started implementing SDFs for font scaling My "wip/chergert/glyphy" branch of GTK 4 does rendering using https://github.com/behdad/glyphy which uses fields to create encoded arc lists and are uploaded to the GPU in texture atlases. The shaders then use that data to render the glyph at any scale/offset. Some work is still needed to land this in GTK 4, particularly around path simplification (mostly done) and slight hinting (probably will land in harfbuzz).

> 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

Another one: https://github.com/behdad/glyphy (SDF, but full vector outlines, not texture sampling)