Earlier quoted context omitted.
It only works for DirectX, OpenGL, Metal, Vulkan: https://partner.steamgames.com/doc/features/overlay It also uses heuristics to find the right window that can lead to issues. Not a common problem, but one I unfortunately ran into :(
What other rendering backend options are there even these days?
Re: Nuklear – A single-header ANSI C immediate mode cross-platform GUI library
#101Electron and other HTML runtimes are what I had in mind. I’m not sure what renderer they use, but it’s something else.