started CMake setup for examples

.gitignore

@@ -21,5 +21,8 @@ dist
 htmlcov
 coverage.xml                
 
+# cmake
+CMakeUserPresets.json
+
 # scratch
 scratch
\ No newline at end of file

CMakeLists.txt

 cmake_minimum_required( VERSION 3.24 )
 project ( sfg-walberla )
 
-SET ( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake )
+option( SFG_WALBERLA_BUILD_EXAMPLES "Build sfg-walberla's examples" OFF )
+
+list (APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake )
 find_package( PystencilsSfg REQUIRED )
 
 add_library( sfg_walberla INTERFACE )
@@ -17,3 +19,7 @@ target_link_libraries(
     INTERFACE
     core stencil domain_decomposition blockforest field
 )
+
+if( ${SFG_WALBERLA_BUILD_EXAMPLES} )
+    add_subdirectory( examples )
+endif()
\ No newline at end of file

examples/CMakeLists.txt

+include(FetchContent)
+
+FetchContent_Declare(
+    walberla
+    GIT_REPOSITORY https://i10git.cs.fau.de/walberla/walberla.git
+)
+
+FetchContent_MakeAvailable(walberla)