[vtk-developers] Version tag and vtkversion defines for new module

[Ben Boeckel]

On Thu, Jan 10, 2019 at 05:24:17 +0000, Andras Lasso wrote:
> Yes, we need this. Please give us examples that show how to write our
> CMake and C++ files to work with both the old and new VTK module
> system.

I have some patches for WikiExamples locally, but have been focusing on
the dashboards first.

For supporting both, something like this pattern is what I was doing:

    find_package(VTK)
    if (VTK_VERSION VERSION_LESS "8.90")
      # old system
      include(${VTK_USE_FILE})
      # modules are linked via `vtkCommonCore`
      # VTK_DEFINITIONS has autoinit information
    else ()
      # modules are linked via `VTK::CommonCore`
      # vtk_module_autoinit is needed
    endif ()

WikiExamples also tries to support VTK5, so it has a bit more logic to
go in there as well.

--Ben