Re: openGL problems: how is it supposed to work?

[Erik Steffl <steffl@bigfoot.com>]

"Marcelo E. Magallon" wrote:
> 
> >> Erik Steffl <steffl@bigfoot.com> writes:
> 
>  >   xscreensaver: openGL demo hacsk are running in software mode when run
>  > by xscreensaver but run accelerated when run from xterm.
> 
>  IIRC, this is a xscreensaver FAQ (alas! I'm not sure)

  yes it was. didn't occur to me it could be a well known problem (I
thought that GL would be used using default settings),

  just in case anybody else has the same problem here's the relevant
part of FAQ:

--------------------- quote from xscreensaver FAQ start

Try editing your .xscreensaver file and changing the memoryLimit setting
to 0. 

     Version 3.33 introduced the memoryLimit option as a precautionary
limit to prevent runaway memory use if one of the display modes happened
to be buggy; it prevents any program launched by xscreensaver from
allocating more than that much memory. It defaults to 50M, which is a
lot. 

     However, apparently certain OpenGL libraries (notably nVidia) do
something strange that makes them appear to allocate more than 128M of
memory for every OpenGL program! Consequently, those programs die on
startup because they aren't able to allocate memory.

--------------------- quote from xscreensaver FAQ end

  I have voodoo III and X 4.x and doing the above fixed the problem.

>  >   is libglide3 still used for implementation of openGL? when I remove
>  > libglide3 the openGL stops working (in HW accelerated mode).
> 
>  libglide3 is used by the 3dfx DRI driver.
> 
>  >   ldd `which glxinfo` does not show libglide to be used but strace
>  > reveals it opens it - is it based on which module is used (I guess only
>  > tdfx uses glide)?
> 
>  the 3dfx driver dlopen's it itself.

  that's what I thought, I just wanted to have it more official:-)

  thanks a lot!

	erik