[Paraview] OpenGL Backend Identification

[Marcus D. Hanwell]

vtkConfigure.h is definitely not the right place for this, and we
worked pretty hard to move things out of it that didn't need to be
there. It will cause almost all classes to recompile, and nothing in
common is even aware of rendering backends. There is a configured
header in the modules that record some settings (such as Cocoa,
Carbon, X11, etc as far as I remember) that would be more appropriate.

I haven't looked at the code in a while, adding something to configure
it in seems reasonable. It is something we originally hoped could be
decided at link time, and it has since become something that can only
really be decided at compile time (which backend to use). With that in
mind, you could simply define something in vtkRenderingCore's
configured header stating which backend it was compiled with.

Marcus

On Wed, Dec 9, 2015 at 12:00 PM, Shawn Waldon <shawn.waldon at kitware.com> wrote:
> There *is* a global VTK configuration header.  vtkConfigure.h has many of
> these definitions and is included in vtkObjectBase.h (so pretty much
> everywhere).  But you may be right that this should go somewhere in the
> rendering code rather than in there.  I am not sure that vtkRenderWindow is
> the best location for it, but I am not as familiar with the code that uses
> the compiler definition.  Does everywhere that #ifdefs VTK_OPENGL2 include
> vtkRenderWindow.h?  Or would we have to pull in that header just for that
> macro?
>
> Shawn
>
> On Wed, Dec 9, 2015 at 11:54 AM, Tim Thirion <tim.thirion at kitware.com>
> wrote:
>>
>> Yes, that was my original question. :) Is the vtkRenderWindow the best
>> place for this? I'm happy to add it.
>>
>> On Wed, Dec 9, 2015 at 11:12 AM, Joachim Pouderoux
>> <joachim.pouderoux at kitware.com> wrote:
>>>
>>> BTW, I took a look but I do not see any way for a third party VTK or PV
>>> application that would not use CMake machinery (and use VTK_OPENGL_BACKEND)
>>> to know if the VTK it uses is based on OpenGL backend 1 or 2.
>>> VTK_OPENGL2 is a compiler definition provided to build VTK or PV but, as
>>> there is no global VTK configuration header, shouldn't we add a function in
>>> vtkRenderWindow to return the version of the backend it is based on?
>>>
>>> Joachim Pouderoux
>>>
>>> PhD, Technical Expert
>>> Kitware SAS
>>>
>>>
>>> 2015-12-08 19:58 GMT+01:00 Ben Boeckel <ben.boeckel at kitware.com>:
>>>>
>>>> On Mon, Dec 07, 2015 at 14:49:51 -0500, Tim Thirion wrote:
>>>> > I'm looking to provide run-time identification of the current OpenGL
>>>> > backend in use. Some questions:
>>>> >
>>>> > 1. VTK #defines VTK_OPENGL2, but ParaView #defines VTKGL2. Is there a
>>>> > particular reason we have both?
>>>>
>>>> VTK used to have both. VTKGL2 should be migrated to VTK_OPENGL2 (as VTK
>>>> did).
>>>>
>>>> > 2. Is there an ideal place to define such a constant? Perhaps on the
>>>> > render
>>>> > window?
>>>>
>>>> The About dialog has a list of information already (versions of Python,
>>>> matplotlib, numpy, Qt, etc.).
>>>>
>>>> --Ben
>>>> _______________________________________________
>>>> Powered by www.kitware.com
>>>>
>>>> Visit other Kitware open-source projects at
>>>> http://www.kitware.com/opensource/opensource.html
>>>>
>>>> Please keep messages on-topic and check the ParaView Wiki at:
>>>> http://paraview.org/Wiki/ParaView
>>>>
>>>> Search the list archives at: http://markmail.org/search/?q=ParaView
>>>>
>>>> Follow this link to subscribe/unsubscribe:
>>>> http://public.kitware.com/mailman/listinfo/paraview
>>>
>>>
>>
>>
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Please keep messages on-topic and check the ParaView Wiki at:
>> http://paraview.org/Wiki/ParaView
>>
>> Search the list archives at: http://markmail.org/search/?q=ParaView
>>
>> Follow this link to subscribe/unsubscribe:
>> http://public.kitware.com/mailman/listinfo/paraview
>>
>
>
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Please keep messages on-topic and check the ParaView Wiki at:
> http://paraview.org/Wiki/ParaView
>
> Search the list archives at: http://markmail.org/search/?q=ParaView
>
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/paraview
>