It's being worked on. Merry Christmas! https://github.com/emilk/egui/issues/3378

Text shaping is anything but easy. Harfbuzz is probably the state of the art open source solution - https://github.com/harfbuzz/harfbuzz

Used in in Android, Chrome, ChromeOS, Firefox, GNOME, GTK+, KDE, Qt, LibreOffice, OpenJDK, XeTeX, PlayStation, Microsoft Edge, Adobe Photoshop, Illustrator, InDesign, Godot Engine, Unreal Engine, ...

For egui, it will be rustybuzz, which is used directly by cosmic-text

https://github.com/harfbuzz/rustybuzz

https://github.com/pop-os/cosmic-text

I thought Photoshop, Illustrator, and InDesign were very good at producing https://notarabic.com/ (at least the author calls out Adobe products in the description)