[SDL] Scaleing, SDL_DOUBLEBUF, SetVidMode, etc.....

Sam Lantinga slouken at devolution.com
Fri Apr 14 02:12:08 PDT 2000


> This explanation was very nice. Thanks Sam. I do have some additional
> questions though.

> 1) What are the requirements to actually get a hw surface when you ask for
> it? I presume you cannot get it under X11? If so what should be used
> instead?

The underlying video driver must have access to the video memory.
You are correct that in X11 you do not have access to the video memory,
without using the DGA video driver.  In this case your blits will all
be done in software, usually using highly optimized C or asm blitters.

> 2) Is there any other restrictions on dubblebuffering than the fact that
> there have to be enough free videomemory? If so, what are the restrictions?

The underlying driver must be able to change the video display panning
during the vertical blank and report when the flip has completed.

See ya!
	-Sam Lantinga, Lead Programmer, Loki Entertainment Software



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