glxgears: couldn't get an RGB, Double-buffered visual ?

Kristian Høgsberg krh at
Tue Apr 8 16:28:46 PDT 2008

On Tue, Apr 8, 2008 at 6:25 PM, Jie Luo <clotho67 at> wrote:
> Jens Stroebel wrote:
> >                Hi.
> >
> > While trying to take a look at the current state of affairs in git HEAD, I
> got:
> >
> > Error: couldn't get an RGB, Double-buffered visual
> >
> > from glxgears.
> >
> > All xorg parts (libs, server, xf86-video-intel, mesa, drm) from git
> checkout of today (2008-04-08), linux kernel
> >
> > Is this being looked into already or should I file a (mesa-) bug?
> >
> >                greets,
> >                  jens
> >
>  I have run into this problem as well. After some debug, I find that
> driConfigEqual used by both glXChooseVisual and glXChooseFBConfig have some
> problems. As Ben Gamari pointed out that driConfigEqual don't take care
> about GLX_DONT_CARE.
>  When called by glXChooseFBConfig, driConfigEqual will return GL_FALSE
> caused by comparing yInverted (it is not being send out by xserver, and
> default set to GLX_DONT_CARE).
>  When driConfigEqual is called by glXChooseVisual, it will return GL_FALSE
> caused by comparing bindToTextureRgb, bindToTextureRgba,
> bindToMipmapTexture, yInverted and bindToTextureTargets.
>  The first four are set to the default value GLX_DONT_CARE and
> bindToTextureTargets are set to default value 0 (I don't know why this
> different from other), because they are not being send to client by xserver.
> I think these five attributes should not be compared for XVisual, as they
> are not send to client by __glXDisp_GetVisualConfigs. And yInverted is also
> should not be used as a compare attribute, as it never send to client by
> both __glXDisp_GetVisualConfigs and DoGetFBConfigs.
>  So may be these attribute need sent to client from both
> __glXDisp_GetVisualConfigs and DoGetFBConfigs or we should just ignore them
> in driConfigEqual. Here is a patch to make glxinfo and glxgears work, but I
> have no idea whether it is correct.

That is exactly the right patch.  Committed to mesa, thanks.

More information about the xorg mailing list