+/* spaceball device functions, defined in freeglut_spaceball.c */
+void fgInitialiseSpaceball( void );
+void fgSpaceballClose( void );
+void fgSpaceballSetWindow( SFG_Window *window );
+
+int fgHasSpaceball( void );
+int fgSpaceballNumButtons( void );
+
+#if TARGET_HOST_POSIX_X11
+int fgIsSpaceballXEvent( const XEvent *ev );
+void fgSpaceballHandleXEvent( const XEvent *ev );
+#endif
+