Function AIGenerateAltBNodePath

Descent3/aipath.cpp:668–774

}

static bool AIGenerateAltBNodePath(object *obj, vector *start_pos, int *start_room, vector *end_pos, int *end_room,
                                   ai_path_info *aip, int *slot, int *cur_node, int handle) {
  int x;
  vector *pos;
  bool f_path_exists = true;

  bn_list *bnlist = BNode_GetBNListPtr(*start_room);
  int last_node = BNode_FindDirLocalVisibleBNode(*start_room, start_pos, &obj->orient.fvec, obj->size);
  if (last_node == -1) {
    f_path_exists = false;
    goto done;
  }
  ASSERT(last_node >= 0);

  for (x = 0; x < AIAltPathNumNodes - 1 && f_path_exists; x++) {
    int cur_room = BOA_INDEX(AIAltPath[x]);
    int next_room = BOA_INDEX(AIAltPath[x + 1]);

    bnlist = BNode_GetBNListPtr(cur_room);
    ASSERT(bnlist);

    if (next_room != cur_room && next_room != BOA_NO_PATH) {
      int portal = BOA_DetermineStartRoomPortal(cur_room, NULL, next_room, NULL);
      if (portal == -1) {
        f_path_exists = false;
      } else {
        int bnode = -1;

        if (cur_room >= 0 && cur_room <= Highest_room_index) {
          bnode = Rooms[cur_room].portals[portal].bnode_index;
          ASSERT(bnode >= 0 && bnode < BNode_GetBNListPtr(cur_room)->num_nodes);
        } else {
          int croom = BOA_connect[cur_room - Highest_room_index - 1][portal].roomnum;
          int cportal = BOA_connect[cur_room - Highest_room_index - 1][portal].portal;

          int r = Rooms[croom].portals[cportal].croom;
          int p = Rooms[croom].portals[cportal].cportal;

          ASSERT(Rooms[r].used && (Rooms[r].flags & RF_EXTERNAL));
          bnode = Rooms[r].portals[p].bnode_index;
          //					ASSERT(bnode >= 0 && bnode < BNode_GetBNListPtr(r)->num_nodes);
        }

        // Add the last room...
        bool f_ok = BNode_FindPath(cur_room, last_node, bnode, obj->size);
        ASSERT(f_ok);
        ASSERT(BNode_PathNumNodes);

        int i;
        for (i = 0; i < BNode_PathNumNodes; i++) {
          pos = &bnlist->nodes[BNode_Path[i]].pos;
          AIPathAddDPathNode(aip, slot, cur_node, pos, cur_room, handle);
        }

        int portal = BOA_DetermineStartRoomPortal(next_room, NULL, cur_room, NULL);
        if (next_room <= Highest_room_index) {
          bnode = Rooms[next_room].portals[portal].bnode_index;
          ASSERT(bnode >= 0);