So I've done a bit of googling and looking at older threads here but I still have no idea how to do it. I've seen some other ways to clip Surfaces with drawn paths like in the context.clip method, but I haven't seen anything like it for two surfaces.
The thing I'd want is some way to draw some surface A to sone surface B in the places determined by some other surface C's alpha layer. I'm pretty new to PyCairo so I'd appreciate the help :)
You are looking for cairo_mask_surface: https://www.cairographics.org/manual/cairo-cairo-t.html#cairo-mask-surface
I do not know how this is accessible in PyCairo, but I would guess ctx.mask_surface(surf_c).