Add framebuffer support to Inventor viewer

src/Gui/SoFCDB.cpp

@@ -47,6 +47,7 @@
 
 #include "propertyeditor/PropertyItem.h"
 #include "NavigationStyle.h"
+#include "Flag.h"
 
 using namespace Gui;
 using namespace Gui::Inventor;
@@ -130,6 +131,9 @@ void Gui::SoFCDB::init()
     BlenderNavigationStyle          ::init();
     TouchpadNavigationStyle         ::init();
 
+    GLGraphicsItem                  ::init();
+    GLFlagWindow                    ::init();
+
     qRegisterMetaType<Base::Vector3f>("Base::Vector3f");
     qRegisterMetaType<Base::Vector3d>("Base::Vector3d");
     init_done = TRUE;