refactor(cmake): check for vtk existance

CMakeLists.txt

@@ -128,11 +128,6 @@ if(VIENNALS_USE_VTK AND VIENNALS_VTK_PYTHON_LIBS)
 elseif(VIENNALS_USE_VTK)
   enable_language(C)
 
-  find_package(VTK QUIET)
-  set(VIENNALS_SYSTEM_VTK
-      ${VTK_FOUND}
-      CACHE INTERNAL "")
-
   CPMFindPackage(
     NAME VTK
     # TODO: Change to 9.3.1 as soon as it's released
@@ -194,16 +189,6 @@ if(VIENNALS_ENABLE_SANITIZER)
   viennacore_enable_sanitizer()
 endif()
 
-# --------------------------------------------------------------------------------------------------------
-# Check need for environment setups
-# --------------------------------------------------------------------------------------------------------
-
-if(NOT VIENNALS_VTK_PYTHON_LIBS AND (NOT VIENNALS_SYSTEM_VTK OR VIENNALS_PACKAGE_PYTHON))
-  set(VIENNALS_VTK_ENV
-      ON
-      CACHE INTERNAL "")
-endif()
-
 # --------------------------------------------------------------------------------------------------------
 # Setup Shared/Static Library
 # --------------------------------------------------------------------------------------------------------

cmake/vtk.cmake

@@ -1,6 +1,11 @@
 macro(setup_vtk_env TARGET OUTPUT)
   message(STATUS "[ViennaLS] Setting up VTK-Environment for ${TARGET}")
 
+  if (NOT TARGET vtksys)
+    message(WARNING "[ViennaLS] Could not find VTK-Target")
+    return()
+  endif()
+
   # We expect all of the VTK binaries to be present in the same directory to which "vtksys" is
   # built. This is currently the case, and has been the case for prior vtk versions - However we
   # should keep an eye on this.

examples/CMakeLists.txt

@@ -1,6 +1,6 @@
 add_custom_target(ViennaLS_Examples ALL)
 
-if(WIN32 AND VIENNALS_VTK_ENV)
+if(WIN32)
   set(CMAKE_RUNTIME_OUTPUT_DIRECTORY $<1:${PROJECT_BINARY_DIR}/examples>)
   setup_vtk_env(ViennaLS_Examples ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
 endif()

python/CMakeLists.txt

@@ -69,9 +69,7 @@ target_compile_definitions(viennals3d PRIVATE -DVIENNALS_PYTHON_DIMENSION=3
 
 set(VIENNALS_LIB_FOLDER ${VIENNALS_LIBRARY_OUTPUT_DIR}/viennals.libs)
 
-if(NOT VIENNALS_VTK_ENV)
-  return()
-endif()
+# Not required for both targets, one will suffice
+setup_vtk_env(viennals2d ${VIENNALS_LIB_FOLDER})
 
-setup_vtk_env(viennals2d ${VIENNALS_LIB_FOLDER}) # Not required for both targets, one will suffice
-install(DIRECTORY ${VIENNALS_LIB_FOLDER} DESTINATION .)
+install(DIRECTORY ${VIENNALS_LIB_FOLDER} DESTINATION . OPTIONAL)

tests/CMakeLists.txt

@@ -1,6 +1,6 @@
 add_custom_target(ViennaLS_Tests ALL)
 
-if(WIN32 AND VIENNALS_VTK_ENV)
+if(WIN32)
   set(CMAKE_RUNTIME_OUTPUT_DIRECTORY $<1:${PROJECT_BINARY_DIR}/tests>)
   setup_vtk_env(ViennaLS_Tests ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
 endif()