These three words already answer your question completely:
1. let the user choose a screen mode on the desired monitor (use ASL_ScreenModeRequest). The two graphics cards have different mode IDs even if they are of the same brand.
2. use OpenScreenTags with SA_DisplayID
3. use the screen pointer from OpenScreen with WA_CustomScreen for all your windows.
These three words already answer your question completely:
1. let the user choose a screen mode on the desired monitor (use ASL_ScreenModeRequest). The two graphics cards have different mode IDs even if they are of the same brand.
2. use OpenScreenTags with SA_DisplayID
3. use the screen pointer from OpenScreen with WA_CustomScreen for all your windows.
@thomas
Thank you very much!
So far I am using IGraphics->BestModeID() after the user has via Shell inputted a desired screen width and height.