-FGAPI void FGAPIENTRY glutWireSierpinskiSponge ( int num_levels, GLfloat offset[3], GLfloat scale ) ;
-FGAPI void FGAPIENTRY glutSolidSierpinskiSponge ( int num_levels, GLfloat offset[3], GLfloat scale ) ;
+FGAPI void FGAPIENTRY glutWireSierpinskiSponge ( int num_levels, GLdouble offset[3], GLdouble scale ) ;
+FGAPI void FGAPIENTRY glutSolidSierpinskiSponge ( int num_levels, GLdouble offset[3], GLdouble scale ) ;
+
+/*
+ * Extension functions, see freeglut_ext.c
+ */
+FGAPI void * FGAPIENTRY glutGetProcAddress( const char *procName );
+