[FIX] CMake Policy CMP0072 issue by choosing GLNVD

[CHANGE] Use only OPENGL_LIBRARIES variable instead of OPENGL_gl_LIBRARY

FiberClusteringToolbox/src/CMakeLists.txt

@@ -136,14 +136,14 @@ COLLECT_COMPILE_FILES( "${MODULE_SOURCE_DIR}" TARGET_CPP_FILES TARGET_H_FILES TA
 IF( CUDA_FOUND AND OW_USE_CUDA )
     FILE( GLOB_RECURSE CUDA_SRC "*.cu" )
     CUDA_ADD_LIBRARY( ${MODULE_NAME} SHARED ${TARGET_CPP_FILES} ${TARGET_H_FILES} ${CUDA_SRC} )
-    TARGET_LINK_LIBRARIES( ${MODULE_NAME} ${CMAKE_STANDARD_LIBRARIES} ${OW_LIB_OPENWALNUT} ${Boost_LIBRARIES} ${OPENGL_gl_LIBRARY} ${OPENSCENEGRAPH_LIBRARIES} ${OPENCL_LIBRARY} ${CUDA_LIBRARIES} )
+    TARGET_LINK_LIBRARIES( ${MODULE_NAME} ${CMAKE_STANDARD_LIBRARIES} ${OW_LIB_OPENWALNUT} ${Boost_LIBRARIES} ${OPENGL_LIBRARIES} ${OPENSCENEGRAPH_LIBRARIES} ${OPENCL_LIBRARY} ${CUDA_LIBRARIES} )
 ELSE()
     FILE( GLOB_RECURSE CUDA_CPP_FILES ${MODULE_SOURCE_DIR}/*Cuda*.cpp )
     FILE( GLOB_RECURSE CUDA_H_FILES   ${MODULE_SOURCE_DIR}/*Cuda*.h )
     LIST( REMOVE_ITEM TARGET_H_FILES ${CUDA_H_FILES} )
     LIST( REMOVE_ITEM TARGET_CPP_FILES ${CUDA_CPP_FILES} )
     ADD_LIBRARY( ${MODULE_NAME} SHARED ${TARGET_CPP_FILES} ${TARGET_H_FILES} )
-    TARGET_LINK_LIBRARIES( ${MODULE_NAME} ${CMAKE_STANDARD_LIBRARIES} ${OW_LIB_OPENWALNUT} ${Boost_LIBRARIES} ${OPENGL_gl_LIBRARY} ${OPENCL_LIBRARY} ${OPENSCENEGRAPH_LIBRARIES} )
+    TARGET_LINK_LIBRARIES( ${MODULE_NAME} ${CMAKE_STANDARD_LIBRARIES} ${OW_LIB_OPENWALNUT} ${Boost_LIBRARIES} ${OPENGL_LIBRARIES} ${OPENCL_LIBRARY} ${OPENSCENEGRAPH_LIBRARIES} )
 ENDIF()
 
 SET_TARGET_PROPERTIES( ${MODULE_NAME} PROPERTIES VERSION ${OW_LIB_VERSION} SOVERSION ${OW_SOVERSION} )

MyOpenWalnutToolbox/tools/cmake/OpenWalnut.cmake

@@ -334,8 +334,12 @@ IF( ANDROID )
   SET( OPENGL_FOUND ON )
   # link against GLES 2
   SET( OPENGL_LIBRARIES "GLESv2" )
-  SET( OPENGL_gl_LIBRARY "GLESv2" )
 ELSE()
+  # The explicit setting of GLVND can be removed, when we set the minimum cmake version to 3.11 or higher.
+  # CMake Policy: CMP0072 https://cmake.org/cmake/help/git-stage/policy/CMP0072.html
+  IF( CMAKE_HOST_SYSTEM MATCHES "Linux" )
+      SET( OpenGL_GL_PREFERENCE "GLVND" )
+  ENDIF()
   FIND_PACKAGE( OpenGL REQUIRED )
   # include the OpenGL header paths
   INCLUDE_DIRECTORIES( SYSTEM ${OPENGL_INCLUDE_DIR} )

MyOpenWalnutToolbox/tools/cmake/OpenWalnutUtils.cmake

@@ -675,7 +675,7 @@ FUNCTION( SETUP_MODULE _MODULE_NAME _MODULE_SOURCE_DIR _MODULE_DEPENDENCIES _MOD
 
     # Setup the target
     ADD_LIBRARY( ${MODULE_NAME} SHARED ${TARGET_CPP_FILES} ${TARGET_H_FILES} )
-    TARGET_LINK_LIBRARIES( ${MODULE_NAME} ${CMAKE_STANDARD_LIBRARIES} ${OW_LIB_OPENWALNUT} ${Boost_LIBRARIES} ${OPENGL_gl_LIBRARY} ${OPENSCENEGRAPH_LIBRARIES} ${_MODULE_DEPENDENCIES} )
+    TARGET_LINK_LIBRARIES( ${MODULE_NAME} ${CMAKE_STANDARD_LIBRARIES} ${OW_LIB_OPENWALNUT} ${Boost_LIBRARIES} ${OPENGL_LIBRARIES} ${OPENSCENEGRAPH_LIBRARIES} ${_MODULE_DEPENDENCIES} )
 
     # Set the version of the library.
     SET_TARGET_PROPERTIES( ${MODULE_NAME} PROPERTIES