src/bridge_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 bridge_map.cpp Map accessor functions for bridges. */
   9
  10 #include "stdafx.h"
  11 #include "landscape.h"
  12 #include "tunnelbridge_map.h"
  13
  14 #include "safeguards.h"
  15
  16
  17 /**
  18  * Finds the end of a bridge in the specified direction starting at a middle tile
  19  * @param tile the bridge tile to find the bridge ramp for
  20  * @param dir  the direction to search in
  21  */
  22 static TileIndex GetBridgeEnd(TileIndex tile, DiagDirection dir)
  23 {
  24         TileIndexDiff delta = TileOffsByDiagDir(dir);
  25
  26         dir = ReverseDiagDir(dir);
  27         do {
  28                 tile += delta;
  29         } while (!IsBridgeTile(tile) || GetTunnelBridgeDirection(tile) != dir);
  30
  31         return tile;
  32 }
  33
  34
  35 /**
  36  * Finds the northern end of a bridge starting at a middle tile
  37  * @param t the bridge tile to find the bridge ramp for
  38  */
  39 TileIndex GetNorthernBridgeEnd(TileIndex t)
  40 {
  41         return GetBridgeEnd(t, ReverseDiagDir(AxisToDiagDir(GetBridgeAxis(t))));
  42 }
  43
  44
  45 /**
  46  * Finds the southern end of a bridge starting at a middle tile
  47  * @param t the bridge tile to find the bridge ramp for
  48  */
  49 TileIndex GetSouthernBridgeEnd(TileIndex t)
  50 {
  51         return GetBridgeEnd(t, AxisToDiagDir(GetBridgeAxis(t)));
  52 }
  53
  54
  55 /**
  56  * Starting at one bridge end finds the other bridge end
  57  * @param tile the bridge ramp tile to find the other bridge ramp for
  58  */
  59 TileIndex GetOtherBridgeEnd(TileIndex tile)
  60 {
  61         assert(IsBridgeTile(tile));
  62         return GetBridgeEnd(tile, GetTunnelBridgeDirection(tile));
  63 }
  64
  65 /**
  66  * Get the height ('z') of a bridge.
  67  * @param t the bridge ramp tile to get the bridge height from
  68  * @return the height of the bridge.
  69  */
  70 int GetBridgeHeight(TileIndex t)
  71 {
  72         int h;
  73         Slope tileh = GetTileSlope(t, &h);
  74         Foundation f = GetBridgeFoundation(tileh, DiagDirToAxis(GetTunnelBridgeDirection(t)));
  75
  76         /* one height level extra for the ramp */
  77         return h + 1 + ApplyFoundationToSlope(f, &tileh);
  78 }