D3D9 backend for egui. Primarily intended for source games like CS:GO and GMod.
It's not perfect by far, but it'll do. This is a rewrite of a fork I had of sy1ntexx's egui-d3d11. The input manager and the example code are still mostly from that repository. A lot of the general structure was inherited, as I found it quite intuitive.
Turns out, porting from D3D11 down to D3D9 is harder than just doing D3D9.
