Function AIFindAltPath

Descent3/aipath.cpp:64–206

Ok to use Highest_room_index offset stuff

// Ok to use Highest_room_index offset stuff
bool AIFindAltPath(object *obj, int i, int j, float *dist) {
  i = BOA_INDEX(i);
  j = BOA_INDEX(j);

  pq PQPath;
  int counter;
  q_item *start_node = new q_item(i, -1, 0.0f);
  q_item *cur_node;
  bool f_found = false;

  q_item *node_list[MAX_ROOMS + 8];

  //	mprintf(0, "AI: Finding an alternate path from %d to %d\n", i, j);

  if (i == -1 || j == -1) {
    delete start_node;
    return false;
  }

  memset(node_list, 0, sizeof(q_item *) * (MAX_ROOMS + 8));

  PQPath.push(start_node);

  while ((cur_node = PQPath.pop())) {
    node_list[BOA_INDEX(cur_node->roomnum)] = cur_node;
    ASSERT(BOA_INDEX(cur_node->roomnum) >= 0 && BOA_INDEX(cur_node->roomnum) <= Highest_room_index + 8);

    if (cur_node->roomnum == j) {
      AIUpdatePathInfo(node_list, i, j);
      f_found = true;
      goto done;
    }

    int num_portals;
    bool f_room = true;
    int t_index;

    if (cur_node->roomnum <= Highest_room_index) {
      num_portals = Rooms[cur_node->roomnum].num_portals;
    } else {
      t_index = cur_node->roomnum - Highest_room_index - 1;
      num_portals = BOA_num_connect[t_index];
      f_room = false;
    }

    for (counter = 0; counter < num_portals; counter++) {
      int next_room;
      q_item *list_item;
      float new_cost;

      if (!BOA_PassablePortal(cur_node->roomnum, counter, false, false))
        continue;

      if (f_room)
        next_room = Rooms[cur_node->roomnum].portals[counter].croom;
      else
        next_room = BOA_connect[t_index][counter].roomnum;