Function ObjLink

Descent3/object.cpp:1436–1478

link the object into the list for its room

// link the object into the list for its room
void ObjLink(int objnum, int roomnum) {
  object *obj = &Objects[objnum];

  ASSERT(objnum != -1);

  ASSERT(obj->roomnum == -1);
  ASSERT(!(obj->flags & OF_BIG_OBJECT));

  if ((obj->size >= MIN_BIG_OBJ_RAD) && (!ROOMNUM_OUTSIDE(roomnum))) {
    BigObjAdd(objnum);
  }

  obj->roomnum = roomnum;

  if (ROOMNUM_OUTSIDE(roomnum)) {
    int cellnum = CELLNUM(roomnum);

    obj->next = Terrain_seg[cellnum].objects;
    Terrain_seg[cellnum].objects = objnum;

    ASSERT(obj->next != objnum);
  } else {
    ASSERT(roomnum >= 0 && roomnum <= Highest_room_index);
    ASSERT(!(Rooms[roomnum].flags & RF_EXTERNAL));

    obj->next = Rooms[roomnum].objects;
    Rooms[roomnum].objects = objnum;
    ASSERT(obj->next != objnum);
  }

  obj->prev = -1;

  if (obj->next != -1)
    Objects[obj->next].prev = objnum;

  ASSERT(Objects[0].next != 0);
  if (Objects[0].next == 0)
    Objects[0].next = -1;

  ASSERT(Objects[0].prev != 0);
  if (Objects[0].prev == 0)
    Objects[0].prev = -1;
}

void ObjUnlink(int objnum) {
  object *obj = &Objects[objnum];