d3d11 alt-tab on fullscreen gives strange result

Question

First of all after 4 hours of debugging I have no problem with my code. But I'm curious why I had issue that I had.

I created fullscreen window with d3d11 rendering. Problem occurred when I tried to alt-tab window and didn't have Present() in my loop (I simply found this issue before implementing rendering function). In that case after minimizing window Red and Blue channels on my screen were swapped (yes, literally).

It took me long time to find because I suspected my swap chain or window itself (sdl). Can you help me find the reason of this bug- for educational purposes?

Answer 1

This usually is due to a graphics driver bug with RGBA swap chains. You can try updating your driver (run Windows Update). But to improve compatibility you can change your swap chain surface format to BGRA (specifically, B8G8R8A8_UNORM). As long as you are just doing normal rendering (and not doing anything fancy like UpdateSubresource directly to the back buffer), you should be able to leave everything else as-is and it will render correctly.