extern uint16_t rrand(char, uint32_t);
extern void update_log (struct World *, char *);
-uint16_t center_offset (uint16_t, uint16_t, uint16_t);
+extern uint16_t center_offset (uint16_t, uint16_t, uint16_t);
extern void turn_over (struct World *, char);
extern void save_game(struct World *);
extern void toggle_window (struct WinMeta *, struct Win *);