src/tunnel_map.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file tunnel_map.cpp Map accessors for tunnels. */
   9
  10 #include "stdafx.h"
  11 #include "tunnelbridge_map.h"
  12
  13 #include "safeguards.h"
  14
  15
  16 /**
  17  * Gets the other end of the tunnel. Where a vehicle would reappear when it
  18  * enters at the given tile.
  19  * @param tile the tile to search from.
  20  * @return the tile of the other end of the tunnel.
  21  */
  22 TileIndex GetOtherTunnelEnd(TileIndex tile)
  23 {
  24         DiagDirection dir = GetTunnelBridgeDirection(tile);
  25         TileIndexDiff delta = TileOffsByDiagDir(dir);
  26         int z = GetTileZ(tile);
  27
  28         dir = ReverseDiagDir(dir);
  29         do {
  30                 tile += delta;
  31         } while (
  32                 !IsTunnelTile(tile) ||
  33                 GetTunnelBridgeDirection(tile) != dir ||
  34                 GetTileZ(tile) != z
  35         );
  36
  37         return tile;
  38 }
  39
  40
  41 /**
  42  * Is there a tunnel in the way in the given direction?
  43  * @param tile the tile to search from.
  44  * @param z    the 'z' to search on.
  45  * @param dir  the direction to start searching to.
  46  * @return true if and only if there is a tunnel.
  47  */
  48 bool IsTunnelInWayDir(TileIndex tile, int z, DiagDirection dir)
  49 {
  50         TileIndexDiff delta = TileOffsByDiagDir(dir);
  51         int height;
  52
  53         do {
  54                 tile -= delta;
  55                 if (!IsValidTile(tile)) return false;
  56                 height = GetTileZ(tile);
  57         } while (z < height);
  58
  59         return z == height && IsTunnelTile(tile) && GetTunnelBridgeDirection(tile) == dir;
  60 }
  61
  62 /**
  63  * Is there a tunnel in the way in any direction?
  64  * @param tile the tile to search from.
  65  * @param z the 'z' to search on.
  66  * @return true if and only if there is a tunnel.
  67  */
  68 bool IsTunnelInWay(TileIndex tile, int z)
  69 {
  70         return IsTunnelInWayDir(tile, z, (TileX(tile) > (Map::MaxX() / 2)) ? DIAGDIR_NE : DIAGDIR_SW) ||
  71                         IsTunnelInWayDir(tile, z, (TileY(tile) > (Map::MaxY() / 2)) ? DIAGDIR_NW : DIAGDIR_SE);
  72 }