pp

CMakeLists.txt

@@ -416,11 +416,12 @@ if(HAVE_FLTK OR HAVE_QT OR ENABLE_GRAPHICS)
     endif(NOT FLTK_PNG)
   endif(HAVE_LIBZ)
   find_package(OpenGL REQUIRED)
-  if(NOT OPENGL_GLU_FOUND)
-    message(SEND_ERROR "Could not find GLU")
-  endif(NOT OPENGL_GLU_FOUND)
+  if(OPENGL_GLU_FOUND)
     add_subdirectory(Graphics)
     set_config_option(HAVE_OPENGL "OpenGL")
+  else(OPENGL_GLU_FOUND)
+    message(SEND_ERROR "Could not find GLU: disabling OpenGL support")
+  endif(OPENGL_GLU_FOUND)
 endif(HAVE_FLTK OR HAVE_QT OR ENABLE_GRAPHICS)
 
 if(ENABLE_ANN)