VMTK build against Slicer with VTK 9.5 is not straightforward

[chir-set]

This patch is needed to build VMTK (a95f3e3) within SlicerVMTK, against VTK 9.5 within Slicer.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0d46a7c..4043110 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12...3.29.1)
+cmake_minimum_required(VERSION 3.3)
 
 project(VMTK)
 
@@ -27,7 +27,7 @@ if(VMTK_WITH_LIBRARY_VERSION)
      )
 endif()
 
-find_package( Python3 COMPONENTS Interpreter )
+find_package( PythonInterp )
 if (NOT VMTK_PYTHON_VERSION)
   set(VMTK_PYTHON_VERSION "python${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR}" CACHE STRING "" FORCE)
 endif ()
@@ -309,17 +309,11 @@ if(VMTK_SCRIPTS_ENABLED)
     ${VMTK_BINARY_DIR}/VMTKConfig.cmake
   @ONLY IMMEDIATE
   )
-  install(FILES ${VMTK_BINARY_DIR}/VMTKConfig.cmake
-    TYPE LIB
-  )
 
   configure_file(
     ${VMTK_SOURCE_DIR}/CMake/VMTKUse.cmake.in
     ${VMTK_BINARY_DIR}/VMTKUse.cmake
   @ONLY IMMEDIATE
   )
-  install(FILES ${VMTK_BINARY_DIR}/VMTKUse.cmake
-    TYPE LIB
-  )
 
 endif()

In brief, it reverses the changes in this file from 6c189dd.

Moreover, the following files must be prevented from being downloaded during the build process:

• vtkWrapHierarchy.cmake
• vtkWrapPython.cmake
• vtkMacroKitPythonWrap.cmake.

diff --git a/CMake/CMakeLists.txt b/CMake/CMakeLists.txt
index d58cbdf..b85b4b8 100644
--- a/CMake/CMakeLists.txt
+++ b/CMake/CMakeLists.txt
@@ -17,11 +17,6 @@ foreach(filename IN ITEMS
   set(url "https://raw.githubusercontent.com/Slicer/vtkAddon/${vtkAddon_version}/CMake/${filename}")
   if(NOT EXISTS ${dest_file})
     file(DOWNLOAD ${url} ${dest_file} EXPECTED_HASH SHA256=${expected_hash})
-  else()
-    file(SHA256 ${dest_file} current_hash)
-    if(NOT ${current_hash} STREQUAL ${expected_hash})
-      file(DOWNLOAD ${url} ${dest_file} EXPECTED_HASH SHA256=${expected_hash})
-    endif()
   endif()
 endforeach()

Instead, they must be manually replaced by the same files found in Slicer's build tree. The online versions of these wrappers seem to need an update.

I don't know what is the best solution for a seamless build of SlicerVMTK. PythonInterp is dropped in 6c189dd, but Slicer itself does not seem to use Python3 regarding the find_package() cmake function and VTK 9.5 looks like being friendly to Python3.

FYI, looking forward for a lasting solution.

[lassoan]

Thanks a lot for working on this. This is a great help!

We should get vtkWrapHierarchy.cmake etc. files from vtkAddon. We may need to update the version at

vmtk/CMake/CMakeLists.txt

Line 2 in a95f3e3

set(vtkAddon_version "8b5c4b2336a4d2d2aaafe87db3642b5302ddcaa5")

(and update the file hashes accordingly).

The switch from find_package( PythonInterp ) to find_package( Python3 COMPONENTS Interpreter ) looks correct,. PythonInterp is deprecated since CMake 3.12. So, it would be great if you could try to make it all work without reverting this change.

Could you please prepare a pull request with the proposed changes?

[chir-set]

We may need to update the version at

A PR regarding vtkAddon files should be within my reach, as well as updating the hashes.

PythonInterp is deprecated since CMake 3.12.

That's my understanding, I have no clue how to get the project configured with find_package( Python3 COMPONENTS Interpreter ) however. A few random attempts failed and searching the web didn't help.

[chir-set]

A PR regarding vtkAddon files should be within my reach

Oups, not really. It thought initially about a PR to update the files in vtkAddons, but that where the files in the Slicer build tree come from !

\https://raw.githubusercontent.com/Slicer/vtkAddon/${vtkAddon_version}/CMake/${filename}

seems to be another kind of repository than a project repository. I have no idea how to make any data available by this means.

Why not just change the URL and the hashes?

[chir-set]

Please see this PR concerning the python wrapper files, thanks.

If it is merged, I'll update the commit hash in SlicerVMTK.