Game application is written in C++ and uses DirectX 8.

I am getting a maximum monitor resolution to calculate it's aspect ratio. Then I use this value to fix game rendering (scale and set clipping to receive normal 4:3 image with black borders on wide screen monitors).

How can I check if monitor is using aspect ratio auto adjustment now? Because my scaling plus monitor scaling makes resulting image overscaled.

Thanks

EDIT: I saw correct different monitor resolution handling with or without aspect ratio auto adjustment in "Royal Envoy" casual game. But don't know how do they do this.