BUG: Address issues related to ITK update to modern interfaces

Recent changes to ITK have been made to use CMake interfaces over raw
libraries and files, along with adding the ITK namespace to targets:
See InsightSoftwareConsortium/ITK#5721

Refactored installation of proxTV so that it is no longer done by the
fetched project but controlled through the ITK module macros as a
target.

Note there is still some "odd" behavior with the Eigen3 dependency
when provided by ITK it is not a target provided by idea, but needs a
find_package done to locate.

This change consistently uses the proxTV namespace for compatibility
between uses of the proxTV.

Author: blowekamp

CMakeLists.txt

@@ -1,13 +1,9 @@
-cmake_minimum_required(VERSION 3.16.2)
+cmake_minimum_required(VERSION 3.22.0)
 project(TotalVariation)
 
-if(ITK_USE_SYSTEM_proxTV)
-  set(TotalVariation_LIBRARIES proxTV::proxTV)
-else()
-  set(TotalVariation_LIBRARIES proxTV)
-endif()
 
-set(${PROJECT_NAME}_THIRD_PARTY 1)
+set(TotalVariation_LIBRARIES proxTV::proxTV)
+
 
 include(itk-module-init.cmake)
 
@@ -16,19 +12,12 @@ if(NOT ITK_SOURCE_DIR)
   list(APPEND CMAKE_MODULE_PATH ${ITK_CMAKE_DIR})
 endif()
 
-include(CMakeParseArguments)
 include(FetchContent)
 
-# Compile definition needed for proxTV headers
-# This will propagate to wrapping.
-# For wrapping to work, requires ITK with patch:
-# https://github.com/InsightSoftwareConsortium/ITK/pull/707
-add_compile_definitions(NOMATLAB)
-
 message(STATUS "TotalVariation_proxTV_USE_EIGEN: ${TotalVariation_proxTV_USE_EIGEN}")
 if(TotalVariation_proxTV_USE_EIGEN)
   if(NOT ITK_USE_SYSTEM_EIGEN)
-    # Set Eigen3_DIR to the internal Eigen3 used in ITK
+    # Set Eigen3_DIR to the internal Eigen3 used in ITK, per documentation in ITK's Eigen3
     set(Eigen3_DIR "${ITKInternalEigen3_DIR}")
     message(STATUS "ITKTotalVariation: Using internal ITK Eigen Config found in: ${Eigen3_DIR}")
   endif()
@@ -53,14 +42,12 @@ else()
   add_compile_definitions(PROXTV_USE_LAPACK)
 endif()
 
-# _proxTV_lib will be `proxTV::proxTV` when find_package, and `proxTV` when add_subdirectory(proxTV_folder)
-set(_proxTV_lib "")
 # if proxTV is built elsewhere
 if(ITK_USE_SYSTEM_proxTV)
   find_package(proxTV REQUIRED CONFIG)
-  set(_proxTV_lib proxTV::proxTV)
   set(proxTV_DIR_INSTALL ${proxTV_DIR})
   set(proxTV_DIR_BUILD ${proxTV_DIR})
+
   # It is only needed to EXPORT_CODE_BUILD when using external proxTV
   set(${PROJECT_NAME}_EXPORT_CODE_BUILD
 "${${PROJECT_NAME}_EXPORT_CODE_BUILD}
@@ -70,6 +57,14 @@ if(NOT ITK_BINARY_DIR)
   find_package(proxTV REQUIRED CONFIG)
 endif()
 ")
+  # When this module is loaded by an app, it is needed to find proxTV and OpenMP
+  set(${PROJECT_NAME}_EXPORT_CODE_INSTALL
+  "${${PROJECT_NAME}_EXPORT_CODE_INSTALL}
+  find_package(OpenMP)
+  set(proxTV_DIR \"${proxTV_DIR_INSTALL}\")
+  find_package(proxTV REQUIRED CONFIG)
+  ")
+
 else() # build proxTV here with the selected Eigen3
   # Build proxTV with C++11
   if(NOT CMAKE_CXX_STANDARD)
@@ -81,64 +76,24 @@ else() # build proxTV here with the selected Eigen3
   if(NOT CMAKE_CXX_EXTENSIONS)
     set(CMAKE_CXX_EXTENSIONS OFF)
   endif()
-
+  message(STATUS "proxTV_Eigen_LIBRARIES: ${proxTV_Eigen_LIBRARIES}")
   set(proxTV_GIT_REPOSITORY "https://github.com/phcerdan/proxTV.git")
-  set(proxTV_GIT_TAG "use_eigen")
+  set(proxTV_GIT_TAG "itk_installation")
   FetchContent_Declare(
     proxtv_fetch
     GIT_REPOSITORY ${proxTV_GIT_REPOSITORY}
-    GIT_TAG ${proxTV_GIT_TAG})
+    GIT_TAG ${proxTV_GIT_TAG}
+     FIND_PACKAGE_ARGS NAMES proxTV REQUIRED CONFIG
+     )
   FetchContent_GetProperties(proxTV_fetch)
   # proxTV options:
-  set(Eigen3_DIR "${Eigen3_DIR}") # This is not needed but explicit helps reader.
   set(proxTV_USE_LAPACK 0)
-  if(NOT DEFINED proxTV_INSTALL_INCLUDE_DIR)
-    if(NOT ITK_SOURCE_DIR)
-      set(ITK_INSTALL_INCLUDE_DIR include/ITK-${ITK_VERSION_MAJOR}.${ITK_VERSION_MINOR})
-    endif()
-    set(proxTV_INSTALL_INCLUDE_DIR ${ITK_INSTALL_INCLUDE_DIR}/proxTV)
-  endif()
-  if(NOT DEFINED proxTV_INSTALL_LIB_DIR)
-    if(NOT ITK_SOURCE_DIR)
-      set(ITK_INSTALL_LIBRARY_DIR lib)
-    endif()
-    set(proxTV_INSTALL_LIB_DIR ${ITK_INSTALL_LIBRARY_DIR})
-  endif()
-  if(NOT DEFINED proxTV_INSTALL_CMAKE_DIR)
-    if(NOT ITK_SOURCE_DIR)
-      set(ITK_INSTALL_PACKAGE_DIR "lib/cmake/ITK-${ITK_VERSION_MAJOR}.${ITK_VERSION_MINOR}")
-    endif()
-    set(proxTV_INSTALL_CMAKE_DIR ${ITK_INSTALL_PACKAGE_DIR}/Modules)
-  endif()
+
   # end proxTV options
 
   FetchContent_MakeAvailable(proxTV_fetch)
-  # proxTV will generate a target proxTV::proxTV when using find_package,
-  # or a library proxTV when using add_subdirectory
-  set(_proxTV_lib proxTV) # proxTV generated in subdirectory
-  set(proxTV_DIR_INSTALL "${CMAKE_INSTALL_PREFIX}/${proxTV_INSTALL_CMAKE_DIR}")
-endif()
-
-# When this module is loaded by an app, load proxTV too.
-set(${PROJECT_NAME}_EXPORT_CODE_INSTALL
-"${${PROJECT_NAME}_EXPORT_CODE_INSTALL}
-find_package(OpenMP)
-set(proxTV_DIR \"${proxTV_DIR_INSTALL}\")
-find_package(proxTV REQUIRED CONFIG)
-")
 
-set(_populate_include_dirs_for_swig TRUE)
-if(${_populate_include_dirs_for_swig})
-  # SWIG (wrapping) requires INCLUDE_DIRS
-  get_target_property(proxTV_INCLUDE_DIRS ${_proxTV_lib} INTERFACE_INCLUDE_DIRECTORIES)
-  string(REGEX REPLACE
-    ".*BUILD_INTERFACE:(.*/proxtv_fetch-build/src/include).*"
-    "\\1"
-    proxTV_INCLUDE_DIRS_STRIP
-    ${proxTV_INCLUDE_DIRS})
-  # message(STATUS "proxTV_INCLUDE_DIRS: ${proxTV_INCLUDE_DIRS}")
-  # message(STATUS "proxTV_INCLUDE_DIRS_STRIP: ${proxTV_INCLUDE_DIRS_STRIP}")
-  set(TotalVariation_INCLUDE_DIRS ${proxTV_INCLUDE_DIRS_STRIP})
+  itk_module_target(proxTV NAMESPACE proxTV::)
 endif()
 
 
@@ -151,5 +106,3 @@ else()
 endif()
 
 
-# Add the proxTV library to Modules/Targets/TotalVariationTargets.cmake
-itk_module_target(${_proxTV_lib} NO_INSTALL)

itk-module-init.cmake

@@ -1,9 +1,6 @@
 option(ITK_USE_SYSTEM_proxTV "Use external proxTV" OFF)
 mark_as_advanced(ITK_USE_SYSTEM_proxTV)
 
-option(ITK_USE_SYSTEM_EIGEN "Use External Eigen3" OFF)
-mark_as_advanced(ITK_USE_SYSTEM_EIGEN)
-
 # In case in the future we switch to use lapack instead of eigen for proxTV.
 option(TotalVariation_proxTV_USE_EIGEN "proxTV in TotalVariation uses EIGEN" ON)
 mark_as_advanced(TotalVariation_proxTV_USE_EIGEN)