glXGetConfig returns wrong info on Sun client

We have an OpenGL-based application running on a Sun workstation, but displaying on a remote GLX server. Depending on the X server, glXGetConfig sometimes returns incorrect information about the available X visuals, and as a result glXChooseVisual fails.

When displaying on a PC running Windows XP and Cygwin/X, for example, glXGetConfig claims that all available X visuals use color indices (that is, GLX_RGBA is false). But in fact, they are all TrueColor visuals, as witnessed by xdpyinfo. And if we ignore this information, the application works fine, except that of course we have to work around the problem by omitting GLX_RGBA from the requested visual attributes.

When displaying on a Mac running OS X and XFree86, glXGetConfig claims that no X visuals support the GLX extension, in spite of the fact that the GLX and SGI-GLX extensions are installed on the server. We have found no workaround for this.

The application runs fine when displaying on a PC running the Exceed X server.

Has anybody out there had similar experiences with Sun’s GLX client? Any suggestions for workarounds?


I can’t say too much about your problem, but we replaced exceed in our company by NX.
We develop with sun sparcs remotely with NX on normal WinXP PCs.
This is much faster and much less costly as with exceed.

I don’t have/had problems with NX/exceed. May be you try it.

Thanks for the info. I don’t see anything on the NX web site about OpenGL support, though…

An opensource wrapper for NX :

cygwin/X was not updated for ages.
The Xming project seem to explicitly support accelerated OpenGL :

Does FreeNX support OpenGL?

Try FreeNX and Xming and tell us which one solves your problems.

My real priority is to make our application work with the hardware/software configurations our users have, and not so much to identify alternate X servers. I suspect that the culprit is Sun’s GLX client, since the same application with the same remote X servers works as expected when it runs on Linux or HP.

That said, I did a quick test with Xming, and it did not work with our application running on Sun. I have not taken the time to figure out why…

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