qt6ct VS glyphy

kvantum can use arc theme and apply it for qt's app with qt5ct and qt6ct

You always use a theme with Qt or Gtk. On Plasma the default Qt and Gtk theme is Breeze, which has not been ported to Qt6 yet. ATM the only Qt Widgets-compatible themes I have on my system are "Fusion" and "Windows" (as in "Windows 95"), both of which look absolutely horrible. Fusion is the default, and it's what you currently see when you open a

For instance, if I open QBittorrent right now (which has been recently ported to Qt 6), it's clearly using the Fusion theme because of that.

By the way, qt6ct exists <https://github.com/trialuser02/qt6ct>, and it's even in Arch's repositories right now. The main issue is that it's useless, because there are simply no Qt6 themes out there yet and KDE still does not support Qt6 so you have to force qt6ct manually.

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.