Use FindOpenGL instead of pkg_search_module( GLU ).

This resolves FTBFS on FreeBSD 13.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 866f96c1f4)

kpovmodeler/CMakeLists.txt

@@ -19,7 +19,7 @@ include_directories(
   ${CMAKE_BINARY_DIR}
   ${TDE_INCLUDE_DIR}
   ${TQT_INCLUDE_DIRS}
-  ${GLU_INCLUDE_DIRS}
+  ${OPENGL_INCLUDE_DIRS}
   ${FREETYPE_INCLUDE_DIRS}
 )
 
@@ -112,7 +112,7 @@ tde_add_library( kpovmodeler SHARED AUTOMOC
     pmlibraryiconview.cpp pmlibraryobjectsearch.cpp pmpluginmanager.cpp
     pmpartiface.skel
   VERSION 0.0.0
-  LINK tdeparts-shared ${GLU_LIBRARIES} ${XMU_LIBRARIES} ${FREETYPE_LIBRARIES}
+  LINK tdeparts-shared ${OPENGL_LIBRARIES} ${XMU_LIBRARIES} ${FREETYPE_LIBRARIES}
   DESTINATION ${LIB_INSTALL_DIR}
 )
 

kpovmodeler/ConfigureChecks.cmake

@@ -10,13 +10,14 @@
 #################################################
 
 # glu
-pkg_search_module( GLU glu )
+set( OpenGL_GL_PREFERENCE LEGACY )
-if( NOT GLU_FOUND )
+find_package( OpenGL )
+if( NOT OPENGL_FOUND )
   check_include_file ( GL/glu.h HAVE_GLU )
   if( NOT HAVE_GLU )
-    tde_message_fatal( "glu is required, but was not found on your system" )
+    tde_message_fatal( "OpenGL (glu) is required, but was not found on your system" )
   endif ( )
-  set( GLU_LIBRARIES "-lGL -lGLU" )
+  set( OPENGL_LIBRARIES "-lGL -lGLU" )
 endif( )