[GtkGLExt] Off-screen pixmap rendering doesn't work

[cbeau <cbeauc gmail com>]

Hi,

I have filed a bug report about this a while back but I have yet to get any feedback about this issue so here it is again.

When I try to run the off-screen pixmap rendering examples that come with gtkglext (cvs version 
1.35 for pixmap.c and 1.21 for pixmap-mixed.c), I get the following Xerror:
----------------------------------------------
The program 'lt-pixmap' received an X Window System error.
This probably reflects a bug in the program.
The error was 'GLXBadContext'.
  (Details: serial 162 error_code 154 request_code 143 minor_code 5)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
------------------------------------------------

I would like to know if anybody knows what causes this and if there is
any work-around or if anyone is working on a solution.
I have found that these example used to work back when direct rendering didn't work on my computer so I am guessing the two
issues are related. I also found the following interesting message on
the DRI User Guide at:
       http://dri.sourceforge.net/doc/DRIuserguide.html

----------------------------------------------
11.2 GLX

The GLX 1.3 API is exported but none of the new 1.3 functions are
operational.

The new glXGetProcAddressARB function is fully supported.

GLXPixmap rendering is only supported for indirect rendering contexts. This
is a common OpenGL limitation. Attempting to use a direct rendering context
with a GLXPixmap will result in an X protocol error.
-------------------------------------------------

I also noticed that the gdk_gl_context_new() function takes as its third argument "direct" which is a boolean which sets  whether rendering is to be done with a direct connection to
         the graphics system. Is this related to the problem mentioned above?

I'll be thankful for any information anybody can provide on this subject.

Cheers,
cbeau.