src/pathfinder/pathfinder_func.h

   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 pathfinder_func.h General functions related to pathfinders. */
   9
  10 #ifndef PATHFINDER_FUNC_H
  11 #define PATHFINDER_FUNC_H
  12
  13 #include "../waypoint_base.h"
  14
  15 /**
  16  * Calculates the tile of given station that is closest to a given tile
  17  * for this we assume the station is a rectangle,
  18  * as defined by its tile are (st->train_station)
  19  * @param station The station to calculate the distance to
  20  * @param tile The tile from where to calculate the distance
  21  * @param station_type the station type to get the closest tile of
  22  * @return The closest station tile to the given tile.
  23  */
  24 static inline TileIndex CalcClosestStationTile(StationID station, TileIndex tile, StationType station_type)
  25 {
  26         const BaseStation *st = BaseStation::Get(station);
  27         TileArea ta;
  28         st->GetTileArea(&ta, station_type);
  29
  30         /* If the rail station is (temporarily) not present, use the station sign to drive near the station */
  31         if (ta.tile == INVALID_TILE) return st->xy;
  32
  33         uint minx = TileX(ta.tile);  // topmost corner of station
  34         uint miny = TileY(ta.tile);
  35         uint maxx = minx + ta.w - 1; // lowermost corner of station
  36         uint maxy = miny + ta.h - 1;
  37
  38         /* we are going the aim for the x coordinate of the closest corner
  39          * but if we are between those coordinates, we will aim for our own x coordinate */
  40         uint x = ClampU(TileX(tile), minx, maxx);
  41
  42         /* same for y coordinate, see above comment */
  43         uint y = ClampU(TileY(tile), miny, maxy);
  44
  45         /* return the tile of our target coordinates */
  46         return TileXY(x, y);
  47 }
  48
  49 #endif /* PATHFINDER_FUNC_H */