[GRASSLIST:4389] Re: Nviz and Debian again

Glynn Clements glynn.clements at virgin.net
Tue Aug 27 10:55:54 EDT 2002

michele.rocc at libero.it wrote:

> > > > You need to do one of the following:
> > > > 
> > > > 1. If your X server supports GLX, but it isn't enabled, then enable
> > > > it; for XFree86 4.x, you need the line:
> > > > 
> > > >     Load "glx"
> > > > 
> > > > in the "Module" section of XF86Config.
> > > > 
> > > > 2. If your X server doesn't support GLX, replace your X server with
> > > > one which does, or
> > > > 
> > > > 3. Replace your GL library (libGL.so.*) with one which implements
> > > > OpenGL on the client side (e.g. Mesa), eliminating the need for the X
> > > > server to support GLX.
> > > 
> > > Actually I am using Mesa but still I have the problem, maybe there is
> > > some particulary extension of Mesa that I have to install?
> > The error message indicates that you are not using Mesa. You may have
> > Mesa installed, but it isn't being used. Mesa is purely client-side;
> > it does not require the GLX extension, it will not make any use of the
> > GLX extension if it does happen to be present, and it will not
> > complain about the fact that the X server lacks the GLX extension.
> > Check for the existence of libGL.so.* in /usr/X11R6/lib; if any such
> > files exist, rename them or move them so that they aren't found.
> In Debian package list I didn't found any openGL... library nor
> libMesaGL... but only xlibmesa...

I have no knowledge of Debian packages. What's important is what's in
the package, not what it's called.

> I found in /usr/X11R6/lib the package libGL.so.* I renamed it

If your /usr/X11R6 is XFree86 4.x, then that file is probably a
"normal" OpenGL library (libGL.so.*) which requires the GLX extension.

> and
> created a link named libGL.so.1 to libOSMesa.so.3.3, because
> there is no library called libMesaGL.so, but this don't works.

libOSMesa is the "off-screen Mesa" library. It is used (in conjunction
with Mesa) for "drawing" into a block of memory. It isn't relevant

> I search for libMesaGL in Debian site within the packages
> page with no results, and a general search in the web point me
> only to RPM packages;
> Searching in Debian packages page again, only with "mesa" word
> I found xlibmesa3 package that is the one I installed and it
> supply the lib libGL.so.1 and I think is the one I found
> in /usr/X11R6/lib dir.

Although the Mesa library might be called libMesaGL, it is more common
for it to be called libGL nowadays.

Note that most OpenGL libraries are called libGL.so.1, because this is
what most OpenGL applications require.

> So I thougt that in this Debian System I'm using (3.0 woody)
> libMesaGL was called libGL.so.1, but at this point it comes
> out the strange message that requires GLX extension and this
> indicates that I'm using openGL...

If you have an OpenGL library which requires the GLX extension,
there's a reasonable chance that your X server supports it (but it may
need to be explicitly enabled; see option 1 from my original reply).

Glynn Clements <glynn.clements at virgin.net>

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