VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Thu Dec 17 2009 - 13:29:52 CST

Rich,
  See the glXChooseVisual() calls that VMD uses when querying the
GPU hardware features. The applicable code is in OpenGLDisplayDevice.C
in the function vmd_get_visual(), from line 435 to line 539.

What is going on here is that one of the calls to glXChooseVisual() that
requests a stereoscopic window (the GLX_STEREO parameter), is succeeding
in getting a stereoscopic window even though it apparently should not.
So far as I know, no Macs with ATI Radeon 9600 graphics chipsets are able
to do stereo, so this combined with the observed behavior your users are
getting is why I believe it to be an error in their GLX implementation.

It is also possible that the error is deeper seated, and that it is coming
from the lower level Apple graphics APIs, and the X11 server is just an
innocent victim here, but I doubt it. Unless you get a stereo visual
when running VMD natively on the Mac, you should not get one when
running it remotely displaying on that same Mac... You should get the
same list of VMD OpenGL features in the VMD startup messages when
using the Mac locally or when remote displaying to it.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Thu, Dec 17, 2009 at 11:22:16AM -0800, Rich Cook wrote:
> You mentioned that Apple's X11 is claiming to have Stereo support when
> in fact it does not. Can you point me at the part of your code that
> is getting the bogus information? I'd like to report it as a bug to
> the XQuartz team so it gets fixed. Thanks
>
> /* A function that takes a single integer argument and returns
> a pointer to a function that takes two integer arguments and
> returns a floating-point number. */
> float (*func2(int a))(int, int);
> Rich Cook
> rcook_at_llnl.gov
>
>
> 

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
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