int in_dungeon(Game_object *obj) { return in_dungeon(obj->get_tx(), obj->get_ty()); }
int in_dungeon(int tx, int ty) { int tnum = ty*tiles_per_chunk + tx; return dungeon_bits[tnum/8] & (1 << (tnum%8)); }
	int in_dungeon(Game_object *obj)// Is object within dungeon?		{ return in_dungeon(obj->get_tx(), obj->get_ty()); }