[vtk-developers] VTK Modularization

[Bill Lorensen]

Marcus,

I hope the VTK developers can work with the Kitware ITK modularization
team and come to some common ground. I was under the impression that
that was the case. They are getting ready to deploy the ITK
modularization within the next few weeks. The ITK developers have had
a lot discussion on this topic and the Modularization team has been
very good at taking in the inputs of the community.

If the ITK and VTK modularizations are not similar, then we have a real problem.

Bill

On Sat, Feb 19, 2011 at 2:33 PM, Marcus D. Hanwell
<marcus.hanwell at kitware.com> wrote:
> Bill,
>
> On Sat, Feb 19, 2011 at 2:29 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
>> Marcus,
>>
>> We might consider adding VTK_LIBRARIES now to ease the transition later.
>
> Ah, I see what you mean. There are a few possibilities I wanted to
> look at with exported targets to ease the transition too.
>>
>> Also, when you say you are not following the ITK modularization does
>> that mean you will not be following its pattern, or that you are not
>> monitoring it. I hope you mean the latter.
>
> I have followed the ITK and Boost modularization efforts, doing some
> work on the Boost build system. I meant that we are not necessarily
> following the exact same pattern, but that we would certainly be
> reusing code and patterns that work best for the VTK project. Is that
> clearer?
>
> I have been traveling a lot the last two weeks, but I think we will be
> meeting to talk more about this and set out likely timelines sometime
> next week.
>
> Marcus
>>
>> On Sat, Feb 19, 2011 at 2:23 PM, Marcus D. Hanwell
>> <marcus.hanwell at kitware.com> wrote:
>>> On Sat, Feb 19, 2011 at 2:10 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
>>>> Folks,
>>>>
>>>> Just a heads-up on some things to expect when VTK is modularized.
>>>>
>>>> ITKv4 has a modularization effort led by Kitware. As part of this, the
>>>> ITK code layout will change accordingly. The work is described here:
>>>> http://www.vtk.org/Wiki/ITK_Release_4/Modularization
>>>>
>>>> For ITK, we will go from about a dozen code directories to over 80
>>>> directories. This will result in over 40 libraries.
>>>>
>>>> For the most part, applications are agnostic regarding source tree
>>>> layout. The include directories are handled by cmake. However, the
>>>> library specification in CMakeLists.txt can  cause issues.
>>>>
>>>> The good news, for ITK, is that we have always had a cmake variable
>>>> called ITK_LIBRARIES. This  meant to be used by applications in
>>>> target_link_libraries rather than listing specific libraries.
>>>> The bad news, for ITK, is that hardly anyone ever used ITK_LIBRARIES.
>>>> The good news is that current ITK applications can start using
>>>> ITK_LIBRARIES within their ITK3 applications and avoid work when the
>>>> move to the modularized ITK4.
>>>>
>>>> VTK does not have a VTK_LIBRARIES at least as far as I know.
>>>>
>>> We are not following the ITK modularization, but will be sharing code
>>> etc where appropriate. Quite a few projects I use (such as Boost and
>>> Qt) also use the PROJECTNAME_LIBRARIES variable approach, and I think
>>> this would be a great pattern to add to VTK too. It should make
>>> handling more libraries in VTK simpler for application developers too.
>>>
>>> Marcus
>>>
>>
>