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 "../tile_cmd.h"
  14 #include "../waypoint_base.h"
  15
  16 /**
  17  * Calculates the tile of given station that is closest to a given tile
  18  * for this we assume the station is a rectangle,
  19  * as defined by its tile are (st->train_station)
  20  * @param station The station to calculate the distance to
  21  * @param tile The tile from where to calculate the distance
  22  * @param station_type the station type to get the closest tile of
  23  * @return The closest station tile to the given tile.
  24  */
  25 inline TileIndex CalcClosestStationTile(StationID station, TileIndex tile, StationType station_type)
  26 {
  27         const BaseStation *st = BaseStation::Get(station);
  28         TileArea ta;
  29         st->GetTileArea(&ta, station_type);
  30
  31         /* If the rail station is (temporarily) not present, use the station sign to drive near the station */
  32         if (ta.tile == INVALID_TILE) return st->xy;
  33
  34         uint minx = TileX(ta.tile);  // topmost corner of station
  35         uint miny = TileY(ta.tile);
  36         uint maxx = minx + ta.w - 1; // lowermost corner of station
  37         uint maxy = miny + ta.h - 1;
  38
  39         /* we are going the aim for the x coordinate of the closest corner
  40          * but if we are between those coordinates, we will aim for our own x coordinate */
  41         uint x = ClampU(TileX(tile), minx, maxx);
  42
  43         /* same for y coordinate, see above comment */
  44         uint y = ClampU(TileY(tile), miny, maxy);
  45
  46         /* return the tile of our target coordinates */
  47         return TileXY(x, y);
  48 }
  49
  50 /**
  51  * Wrapper around GetTileTrackStatus() and TrackStatusToTrackdirBits(), as for
  52  * single tram bits GetTileTrackStatus() returns 0. The reason for this is
  53  * that there are no half-tile TrackBits in OpenTTD.
  54  * This tile, however, is a valid tile for trams, one on which they can
  55  * reverse safely. To "fix" this, pretend that if we are on a half-tile, we
  56  * are in fact on a straight tram track tile. CFollowTrackT will make sure
  57  * the pathfinders cannot exit on the wrong side and allows reversing on such
  58  * tiles.
  59  */
  60 inline TrackdirBits GetTrackdirBitsForRoad(TileIndex tile, RoadTramType rtt)
  61 {
  62         TrackdirBits bits = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_ROAD, rtt));
  63
  64         if (rtt == RTT_TRAM && bits == TRACKDIR_BIT_NONE) {
  65                 if (IsNormalRoadTile(tile)) {
  66                         RoadBits rb = GetRoadBits(tile, RTT_TRAM);
  67                         switch (rb) {
  68                                 case ROAD_NE:
  69                                 case ROAD_SW:
  70                                         bits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
  71                                         break;
  72
  73                                 case ROAD_NW:
  74                                 case ROAD_SE:
  75                                         bits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
  76                                         break;
  77
  78                                 default: break;
  79                         }
  80                 }
  81         }
  82
  83         return bits;
  84 }
  85
  86 #endif /* PATHFINDER_FUNC_H */