src/pathfinder/pathfinder_func.h

   1 /* $Id: pathfinder_func.h 18809 2010-01-15 16:41:15Z rubidium $ */
   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 pathfinder_func.h General functions related to pathfinders. */
  11
  12 #ifndef PATHFINDER_FUNC_H
  13 #define PATHFINDER_FUNC_H
  14
  15 #include "../waypoint_base.h"
  16
  17 /**
  18  * Calculates the tile of given station that is closest to a given tile
  19  * for this we assume the station is a rectangle,
  20  * as defined by its tile are (st->train_station)
  21  * @param station The station to calculate the distance to
  22  * @param tile The tile from where to calculate the distance
  23  * @param station_type the station type to get the closest tile of
  24  * @return The closest station tile to the given tile.
  25  */
  26 static inline TileIndex CalcClosestStationTile(StationID station, TileIndex tile, StationType station_type)
  27 {
  28         const BaseStation *st = BaseStation::Get(station);
  29         TileArea ta;
  30         st->GetTileArea(&ta, station_type);
  31
  32         /* If the rail station is (temporarily) not present, use the station sign to drive near the station */
  33         if (ta.tile == INVALID_TILE) return st->xy;
  34
  35         uint minx = TileX(ta.tile);  // topmost corner of station
  36         uint miny = TileY(ta.tile);
  37         uint maxx = minx + ta.w - 1; // lowermost corner of station
  38         uint maxy = miny + ta.h - 1;
  39
  40         /* we are going the aim for the x coordinate of the closest corner
  41          * but if we are between those coordinates, we will aim for our own x coordinate */
  42         uint x = ClampU(TileX(tile), minx, maxx);
  43
  44         /* same for y coordinate, see above comment */
  45         uint y = ClampU(TileY(tile), miny, maxy);
  46
  47         /* return the tile of our target coordinates */
  48         return TileXY(x, y);
  49 }
  50
  51 #endif /* PATHFINDER_FUNC_H */