Re: GLX in bad state

On Wed, 11 Feb 2004, Ove Kaaven wrote:

> I had the impression that the ARB has been working on a
> GLX_ARB_render_texture for some time now. But they do seem a little bit
> slow about it... perhaps they're too focused on OpenGL 2.0.
>
> But I hear that the current OpenGL 2.0 draft also has a bunch of issues
> that will be a problem for WineX. Peter might know more about that.

I only know that which is available on the Net.  Peter certainly knows my 
end of it because I told him.

At the end of the WGL_ARB_render_texture spec in the Revision History it says:

  11/12/00    pwomack     Created. Copied from GLX extension. Added WGL
                          calls and removed all GLX-centric stuff.

However, at http://oss.sgi.com/projects/ogl-sample/registry there is no 
such GLX extension.  This is an ARB extension.  It just doesn't include 
GLX in this case.  The name is ARB_render_texture.

The OpenGL specs, to my understanding, represent the lowest common 
denominator in terms of features.  I see no problem in using an ARB 
extension instead of the core OpenGL functions.  It is important to have 
the extensions supported before worrying about the extensions becoming 
mainstream OpenGL.  The mainstream is important because it means that 
WineX does not need to deal with a variety of vendor specific extensions.

> Note that the ATI FireGL drivers have an undocumented ATI_render_texture
> extension, perhaps we could use that when ATI releases new drivers that
> WineX does not have so many issues with. But obviously that wouldn't
> solve the problem for nvidia cards.

I would be very interested to see some performance results on some of the 
games I have studied with these new FireGL drivers.  ATI_render_texture is the 
predecessor to ARB_render_texture (sans 3D textures).  It appears to me 
that a GLX implementation should be very easy.  But shouldn't ATI produce a
spec first?  Why have undocumented extensions in drivers?

Without any access to the history of this, my impression is that we don't 
have this extension because of lack of interest.  If I try to approach 
SGI, NVidia or ATI myself I should expect no response.  I think we should 
turn this into an issue and put some drive into it.

Nadav Frum
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