[SDL] Re: sdl GL with stencil buffer

Franck Guillaud fguillaud at mailivs.ivs.fr
Wed Apr 26 10:32:48 PDT 2000


"A. Umbach" wrote:
> 
> Franck Guillaud <fguillaud at mailivs.ivs.fr> schrieb am 26 Apr 2000:
> 
> > > using  the below code without the stencil buffer line It works fine
> > > but with the stencil buffer line it starts and bombs out with :
> > >
> > > "Unable to create OpenGL screen: could not determine glx visual info"
> > >
> > > this is using SDL ver 1.1.2 and XFree86 4 with the opengl Dri for
> > > voodoo banshee working perfectly ....
> 
> > >         SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, 2 );
> > >
> > >    SDL_SetVideoMode(w, h, 16, SDL_OPENGL | SDL_FULLSCREEN)
> 
> > Voodoo cards doesn't have stencil buffer.
> > GLX is unable to satisfy your request.
> 
> Well, glx should fallback to software rendering then, shouldn't it?

    Well, AFAIK, glX doesn't know anything about software or hardware
rendering, it's
just a glu between OpenGL implementation and the X11 windowing system.
But you're almost right :the
Opengl driver should fallback to software rendering if it couldn't
satisfy the GlX request.

  It's seems that here the Voodoo DRI driver prefers to reject the
request than
satisfying it with very very bad perfs.

                               Franck.



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