hi,
I have 2 questions about the output setting:
1) is it correct that opengl, openglnb and ddraw are they only 3 output settings that use rendering by the graphics card, while surface and overlay use software rendering?
2) what is the difference between surface and overlay? (in human language please, i'm not a programmer!)
thx!
wrote:1) is it correct that opengl, openglnb and ddraw are they only 3 output settings that use rendering by the graphics card, while surface and overlay use software rendering?
The main rendering is always done in software. However, using eg OpenGL, you can use the graphics card to scale and post-process the image.
wrote:2) what is the difference between surface and overlay? (in human language please, i'm not a programmer!)
This is a bit of a technical thing in DirectDraw.
A surface is a regular framebuffer/texture, if that makes sense.
An overlay is a special kind of 'texture', which can be, well, 'overlaid' onto your desktop screen by the hardware (think of it as a very large hardware sprite).
It is somewhat outdated technology by now, but in the early days of accelerated movie decoding, TV tuners and such, an overlay could be used to place a video screen on top of your desktop, which could also include some scaling/filtering/conversion operations of the decoding process. As you can see, it can make sense to also use this feature for the video output of an emulator in some cases.
However, modern hardware and desktop environments generally don't support overlays anymore. In Windows, if you run software which tries to use overlays, it will automatically disable Aero, because it is not compatible with overlays.