There's an .exe in the GK directory with the aforementioned filename. The options are overlay, surface, Direct3D, DDraw and OpenGL. Are these for different compatibilities? I just had a crash that seemed to be related to graphics (on the map, something to do with a "map element" IIRC) so it'd be nice to know if there was a way for tuning it better for my ATI card.
The settings don't affect how GK itself renders its graphics, but how DOSBox outputs them, so they will not fix crashes related to the graphics in the game. If the game otherwise displays correctly (and runs smoothly), changing the graphics mode of DOSBox is not going to help you with the bug you encountered. surface
is unaccelerated output using GDI, and does not support scaling. I'm not sure what overlay
uses, but it probably must be hardware-accelerated, and it supports scaling. ddraw
uses the deprecated DirectDraw API while direct3d
uses, of course, Direct3D. For reasons unknown to me, ddraw
automatically applies a bilinear filter when scaling—a pretty strong one making the picture very blurry, so you might want to avoid that one. direct3d
doesn't filter unless you tell it to. The same would go for opengl
stands for "no bilinear filtering"), but for some reason the GOG configuration tool doesn't offer the latter choice. You could set it yourself in dosbox.conf, but I'm not aware of any advantages over just using direct3d
unless you're having compatibility issues with your video drivers.
I am running Windows 7 64-bit and an ATI Radeon HD4870 card, and have never had the need to use anything other than Direct3D output.