Megalomaniak Thank you! It's going to be difficult but I'm sure it'll work in the end.
@cybereality Alright, here's the deal:
Serendipidously, I already have something resembling working software! I found something called CSharpMath, which is a C#-library for rendering LaTeX that - after some fiddling - I could import into Godot Mono. It has has a bunch of different frontends for directly displaying the expressions, but of course none of them has anything to do with Godot. SVG also isn't supported.
So my first working version renders to a PNG, jams that into a ByteArray, turns that into the engine's implementation of an image and then pushes this into a texture. Behold the (maybe?) first LaTeX rendered inside Godot:
Well, it's not the prettiest, but it does work.
I'm conflicted where to go from here. I wonder if I can somehow improve the results of this approach. As it says in the library's Readme though, it is known to have artifacts which I already could see without trying to break it - not to speak of using it (old software development joke). If I was good at C#, I would try to implement the library's specifications for a drawing frontend and execute it inside Godot's CanvasItem's _draw() method, right? If anyone sees a better way, please tell me.
(My attempts with C++ were all all about as successful as Team Rocket in the Pokémon anime. If I see one more compiler error, I'm going to cry.) (Edit: Grammar)
