[vtk-developers] [LONG]Core-promoted OpenGL extensions management in VTK

[Francois Bertel]

Moreland, Kenneth wrote:
> * There is a lot of manual coding to get this to work. There is no way for the automated tools to identify the promotions.

Yes, this is exactly what I said in section 4 of the original email. And I have done the manual coding in the files I sent in attachment.

>  It also means that users might run into other promoted extensions that have not yet been hand coded in.

No, so far I went through the appendices of the OpenGL spec, and went through all of the extensions promoted as core features, up to OpenGL 2.0.


> It would be nice if there was a mechanism so that if someone identified and coded a promotion, they could use it without having to modify VTK and then be able to submit it for inclusion into the repository.

Can you explain me more about that? What do you have in mind?

> * There is no documentation for the promoted extensions.

You mean in the code I attached to my email, right? Because on the other hand, there is some documentation in the OpenGL spec. Each appendix about some specific OpenGL version lists the set of extensions that were promoted as core OpenGL features.

http://www.opengl.org/documentation/specs/
http://www.opengl.org/registry/doc/glspec21.20061201.pdf


> There needs to be some way to document which extensions are promoted and what these extensions are promoted to.

Again, these core-promoted extensions are listed in the appendices of the OpenGL spec. It sounds enough to me.

> * Consider multiple promotions.

I was only talking about extension promoted as core feature, not intermediate promotion. In the spec, there is only one version of each extension which is promoted as core feature.

> I don't think there should be any issue in updated the glext.h headers in VTK, but keep in mind that when you do you may need to make changes to ParseOGLExt to get it to load correctly.

Ok, I am not in an hurry for touching ParseOGLExt :-)

Thanks a lot for your feedback, I know my email was long and painful to read :-)

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François Bertel, PhD  | Kitware Inc. Suite 204
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