"assumed" graphic card memory

[Frank Richter]

On 13.07.2006 18:00, Peter Beutner wrote:
>>>> It might be possible to guesstimate the available memory:
>>>> http://delphi3d.net/articles/viewarticle.php?article=texman.htm
> quoting from the article:
> ---
> The implementation of the glAreTexturesResident() function, which is 
> so critical for this technique, has not been properly standardized.
> [...]
> This makes the technique described in this article pretty much 
> useless - unless you want to put "NVidia 3D cards only" in your app's 
> system requirements.
> ---

I think the article exaggerates. (a) it refers to one driver which
exhibits the problem - Matrox G400 GL, on Win32. Linux drivers may
actually all properly support that function. (b) you could use a cap -
e.g. never report more than 50% of the total system ram as VRAM. Or use
that as a threshold for a heuristic - if more than that amount of
textures are reported as "resident", assume the logic is broken.

Getting the RAM amount directly from the driver is definitely
preferable. However, there's no universal way to do that - so consider
the glAreTexturesResident() approach as a fallback in case no better way
is available.

-f.r.