src/bridge_map.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * 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.
   6  * 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.
   7  * 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/>.
   8  */
   9
  10 /** @file bridge_map.cpp Map accessor functions for bridges. */
  11
  12 #include "stdafx.h"
  13 #include "landscape.h"
  14 #include "tunnelbridge_map.h"
  15
  16 #include "safeguards.h"
  17
  18
  19 /**
  20  * Finds the end of a bridge in the specified direction starting at a middle tile
  21  * @param tile the bridge tile to find the bridge ramp for
  22  * @param dir  the direction to search in
  23  */
  24 static TileIndex GetBridgeEnd(TileIndex tile, DiagDirection dir)
  25 {
  26         TileIndexDiff delta = TileOffsByDiagDir(dir);
  27
  28         dir = ReverseDiagDir(dir);
  29         do {
  30                 tile += delta;
  31         } while (!IsBridgeTile(tile) || GetTunnelBridgeDirection(tile) != dir);
  32
  33         return tile;
  34 }
  35
  36
  37 /**
  38  * Finds the northern end of a bridge starting at a middle tile
  39  * @param t the bridge tile to find the bridge ramp for
  40  */
  41 TileIndex GetNorthernBridgeEnd(TileIndex t)
  42 {
  43         return GetBridgeEnd(t, ReverseDiagDir(AxisToDiagDir(GetBridgeAxis(t))));
  44 }
  45
  46
  47 /**
  48  * Finds the southern end of a bridge starting at a middle tile
  49  * @param t the bridge tile to find the bridge ramp for
  50  */
  51 TileIndex GetSouthernBridgeEnd(TileIndex t)
  52 {
  53         return GetBridgeEnd(t, AxisToDiagDir(GetBridgeAxis(t)));
  54 }
  55
  56
  57 /**
  58  * Starting at one bridge end finds the other bridge end
  59  * @param t the bridge ramp tile to find the other bridge ramp for
  60  */
  61 TileIndex GetOtherBridgeEnd(TileIndex tile)
  62 {
  63         assert(IsBridgeTile(tile));
  64         return GetBridgeEnd(tile, GetTunnelBridgeDirection(tile));
  65 }
  66
  67 /**
  68  * Get the height ('z') of a bridge.
  69  * @param tile the bridge ramp tile to get the bridge height from
  70  * @return the height of the bridge.
  71  */
  72 int GetBridgeHeight(TileIndex t)
  73 {
  74         int h;
  75         Slope tileh = GetTileSlope(t, &h);
  76         Foundation f = GetBridgeFoundation(tileh, DiagDirToAxis(GetTunnelBridgeDirection(t)));
  77
  78         /* one height level extra for the ramp */
  79         return h + 1 + ApplyFoundationToSlope(f, &tileh);
  80 }