I am trying to make posters for secens from my program. I can grab the screen by using IDirect3DDevice9::
GetBackBuffer. However it is limited to the screen resolutions of my display, 2560x1600. The new 4K displays can go up to 3840x2160, but even that is not good enough for large posters. I would like to have images of 6000x4000 or higher.
Is this possible? Do I need to use a software device to render in a higher resolution than the display? If so, how?