[Paraview] OpenGL Backend Identification

[Ben Boeckel]

On Thu, Dec 10, 2015 at 09:29:27 -0500, Ken Martin wrote:
> Maybe vtkRenderingOpenGLConfigure.h ?
> 
> That header is configured from a .in file for both the old and new backend.
> We could define VTK_OPENGL2 in that header and applications could include
> it as needed.  That header appears to get installed. The only issue I see
> is that if someone built VTK with no rendering then that header file might
> not exist.

The library to link to doesn't either for that matter…

> Does that work? If so I can put the VTK_OPENGL2 definition in there.

It looks like a good location to me.

--Ben