From: Jon TURNEY <jon.turney@dronecode.org.uk>
   Date: Wed, 19 Jan 2011 21:11:12 +0000

   Anyhow, can you try with 'GLWIN_NO_WGL_EXTENSIONS=1 XWin -wgl -multiwindow'

Thanks.  I did this and it worked.  However, for a particular paraview
dataset that I happened to have lying around it is slower than direct
rendering by a factor of about 2.  That may be related to the fact
that this particular scene has wiggly tubes with structure too small
to show on the screen, so there is a high ratio of data to things that
actually get displayed.  For the same scene, unaccelerated indirect
rendering is much slower than accelerated, perhaps by a factor of 10.
So when you can't use direct rendering, acceleration is a big help.

Once I say -wgl, direct rendering no longer works.  That is, if I
don't set LIBGL_ALWAYS_INDIRECT, then I get a long (infinite?)
sequence of errors like this:

X Error: BadMatch (invalid parameter attributes) 8
  Major opcode: 73 (X_GetImage)
  Resource id:  0xa0039a

I attach my XWin.0.log from a test in which I first succeeded with
LIBGL_ALWAYS_INDIRECT and then got the error above without it.

                                        Ken