- Only an SDL2 `platform` implementation [is done](https://github.com/NoelFB/blah/blob/master/private/blah/internal/platform_sdl2.cpp). CMake will need to find SDL2 through `SDL2_INCLUDE_DIRS` and `SDL2_LIBRARIES`
- Only an OpenGL `graphics` implementation [is done](https://github.com/NoelFB/blah/blob/master/private/blah/internal/graphics_opengl.cpp), so it currently requires OpenGL.
- The rendering layer may be replaced with [FNA3D](https://github.com/FNA-XNA/FNA3D), [BGFX](https://github.com/bkaradzic/bgfx), [Sokol](https://github.com/floooh/sokol), or something else.