# npf.cpp

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    00001 /* $Id$ */
    00002
    00003 /*
    00004  * This file is part of OpenTTD.
    00005  * 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.
    00006  * 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.
    00007  * 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/>.
    00008  */
    00009
    00012 #include "../../stdafx.h"
    00013 #include "../../debug.h"
    00014 #include "../../network/network.h"
    00015 #include "../../viewport_func.h"
    00016 #include "../../ship.h"
    00017 #include "../../roadstop_base.h"
    00018 #include "../../depot_map.h"
    00019 #include "../../infrastructure_func.h"
    00020 #include "../pathfinder_func.h"
    00021 #include "../pathfinder_type.h"
    00022 #include "../follow_track.hpp"
    00023 #include "aystar.h"
    00024
    00025 static const uint NPF_HASH_BITS = 12;
    00026 /* Do no change below values */
    00027 static const uint NPF_HASH_SIZE = 1 << NPF_HASH_BITS;
    00028 static const uint NPF_HASH_HALFBITS = NPF_HASH_BITS / 2;
    00029 static const uint NPF_HASH_HALFMASK = (1 << NPF_HASH_HALFBITS) - 1;
    00030
    00032 struct NPFFindStationOrTileData {
    00033   TileIndex dest_coords;
    00034   StationID station_index;
    00035   bool reserve_path;
    00036   StationType station_type;
    00037   bool not_articulated;
    00038   const Vehicle *v;
    00039 };
    00040
    00042 enum AyStarUserDataType {
    00043   NPF_TYPE = 0,
    00044   NPF_SUB_TYPE,
    00045   NPF_OWNER,
    00046   NPF_RAILTYPES,
    00047 };
    00048
    00050 enum AyStarNodeUserDataType {
    00051   NPF_TRACKDIR_CHOICE = 0,
    00052   NPF_NODE_FLAGS,
    00053 };
    00054
    00056 enum NPFNodeFlag {
    00057   NPF_FLAG_SEEN_SIGNAL,
    00058   NPF_FLAG_2ND_SIGNAL,
    00059   NPF_FLAG_3RD_SIGNAL,
    00060   NPF_FLAG_REVERSE,
    00061   NPF_FLAG_LAST_SIGNAL_RED,
    00062   NPF_FLAG_LAST_SIGNAL_BLOCK,
    00063   NPF_FLAG_IGNORE_START_TILE,
    00064   NPF_FLAG_TARGET_RESERVED,
    00065   NPF_FLAG_IGNORE_RESERVED,
    00066 };
    00067
    00069 struct NPFFoundTargetData {
    00070   uint best_bird_dist;
    00071   uint best_path_dist;
    00072   Trackdir best_trackdir;
    00073   AyStarNode node;
    00074   bool res_okay;
    00075 };
    00076
    00077 static AyStar _npf_aystar;
    00078
    00079 /* The cost of each trackdir. A diagonal piece is the full NPF_TILE_LENGTH,
    00080  * the shorter piece is sqrt(2)/2*NPF_TILE_LENGTH =~ 0.7071
    00081  */
    00082 #define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)
    00083 static const uint _trackdir_length[TRACKDIR_END] = {
    00084   NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH,
    00085   0, 0,
    00086   NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH
    00087 };
    00088
    00092 static inline bool NPFGetFlag(const AyStarNode *node, NPFNodeFlag flag)
    00093 {
    00094   return HasBit(node->user_data[NPF_NODE_FLAGS], flag);
    00095 }
    00096
    00100 static inline void NPFSetFlag(AyStarNode *node, NPFNodeFlag flag, bool value)
    00101 {
    00102   SB(node->user_data[NPF_NODE_FLAGS], flag, 1, value);
    00103 }
    00104
    00111 static uint NPFDistanceTrack(TileIndex t0, TileIndex t1)
    00112 {
    00113   const uint dx = Delta(TileX(t0), TileX(t1));
    00114   const uint dy = Delta(TileY(t0), TileY(t1));
    00115
    00116   const uint straightTracks = 2 * min(dx, dy); // The number of straight (not full length) tracks
    00117   /* OPTIMISATION:
    00118    * Original: diagTracks = max(dx, dy) - min(dx,dy);
    00119    * Proof:
    00120    * (dx+dy) - straightTracks  == (min + max) - straightTracks = min + max - 2 * min = max - min */
    00121   const uint diagTracks = dx + dy - straightTracks; // The number of diagonal (full tile length) tracks.
    00122
    00123   /* Don't factor out NPF_TILE_LENGTH below, this will round values and lose
    00124    * precision */
    00125   return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;
    00126 }
    00127
    00135 static uint NPFHash(uint key1, uint key2)
    00136 {
    00137   /* TODO: think of a better hash? */
    00138   uint part1 = TileX(key1) & NPF_HASH_HALFMASK;
    00139   uint part2 = TileY(key1) & NPF_HASH_HALFMASK;
    00140
    00141   assert(IsValidTrackdir((Trackdir)key2));
    00142   assert(IsValidTile(key1));
    00143   return ((part1 << NPF_HASH_HALFBITS | part2) + (NPF_HASH_SIZE * key2 / TRACKDIR_END)) % NPF_HASH_SIZE;
    00144 }
    00145
    00146 static int32 NPFCalcZero(AyStar *as, AyStarNode *current, OpenListNode *parent)
    00147 {
    00148   return 0;
    00149 }
    00150
    00151 /* Calcs the heuristic to the target station or tile. For train stations, it
    00152  * takes into account the direction of approach.
    00153  */
    00154 static int32 NPFCalcStationOrTileHeuristic(AyStar *as, AyStarNode *current, OpenListNode *parent)
    00155 {
    00156   NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
    00157   NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
    00158   TileIndex from = current->tile;
    00159   TileIndex to = fstd->dest_coords;
    00160   uint dist;
    00161
    00162   /* for train-stations, we are going to aim for the closest station tile */
    00163   if (as->user_data[NPF_TYPE] != TRANSPORT_WATER && fstd->station_index != INVALID_STATION) {
    00164     to = CalcClosestStationTile(fstd->station_index, from, fstd->station_type);
    00165   }
    00166
    00167   if (as->user_data[NPF_TYPE] == TRANSPORT_ROAD) {
    00168     /* Since roads only have diagonal pieces, we use manhattan distance here */
    00169     dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;
    00170   } else {
    00171     /* Ships and trains can also go diagonal, so the minimum distance is shorter */
    00172     dist = NPFDistanceTrack(from, to);
    00173   }
    00174
    00175   DEBUG(npf, 4, "Calculating H for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), dist);
    00176
    00177   if (dist < ftd->best_bird_dist) {
    00178     ftd->best_bird_dist = dist;
    00179     ftd->best_trackdir = (Trackdir)current->user_data[NPF_TRACKDIR_CHOICE];
    00180   }
    00181   return dist;
    00182 }
    00183
    00184
    00185 /* Fills AyStarNode.user_data[NPF_TRACKDIRCHOICE] with the chosen direction to
    00186  * get here, either getting it from the current choice or from the parent's
    00187  * choice */
    00188 static void NPFFillTrackdirChoice(AyStarNode *current, OpenListNode *parent)
    00189 {
    00190   if (parent->path.parent == NULL) {
    00191     Trackdir trackdir = current->direction;
    00192     /* This is a first order decision, so we'd better save the
    00193      * direction we chose */
    00194     current->user_data[NPF_TRACKDIR_CHOICE] = trackdir;
    00195     DEBUG(npf, 6, "Saving trackdir: 0x%X", trackdir);
    00196   } else {
    00197     /* We've already made the decision, so just save our parent's decision */
    00198     current->user_data[NPF_TRACKDIR_CHOICE] = parent->path.node.user_data[NPF_TRACKDIR_CHOICE];
    00199   }
    00200 }
    00201
    00202 /* Will return the cost of the tunnel. If it is an entry, it will return the
    00203  * cost of that tile. If the tile is an exit, it will return the tunnel length
    00204  * including the exit tile. Requires that this is a Tunnel tile */
    00205 static uint NPFTunnelCost(AyStarNode *current)
    00206 {
    00207   DiagDirection exitdir = TrackdirToExitdir(current->direction);
    00208   TileIndex tile = current->tile;
    00209   if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
    00210     /* We just popped out if this tunnel, since were
    00211      * facing the tunnel exit */
    00212     return NPF_TILE_LENGTH * (GetTunnelBridgeLength(current->tile, GetOtherTunnelEnd(current->tile)) + 1);
    00213     /* @todo: Penalty for tunnels? */
    00214   } else {
    00215     /* We are entering the tunnel, the enter tile is just a
    00216      * straight track */
    00217     return NPF_TILE_LENGTH;
    00218   }
    00219 }
    00220
    00221 static inline uint NPFBridgeCost(AyStarNode *current)
    00222 {
    00223   return NPF_TILE_LENGTH * GetTunnelBridgeLength(current->tile, GetOtherBridgeEnd(current->tile));
    00224 }
    00225
    00226 static uint NPFSlopeCost(AyStarNode *current)
    00227 {
    00228   TileIndex next = current->tile + TileOffsByDiagDir(TrackdirToExitdir(current->direction));
    00229
    00230   /* Get center of tiles */
    00231   int x1 = TileX(current->tile) * TILE_SIZE + TILE_SIZE / 2;
    00232   int y1 = TileY(current->tile) * TILE_SIZE + TILE_SIZE / 2;
    00233   int x2 = TileX(next) * TILE_SIZE + TILE_SIZE / 2;
    00234   int y2 = TileY(next) * TILE_SIZE + TILE_SIZE / 2;
    00235
    00236   int dx4 = (x2 - x1) / 4;
    00237   int dy4 = (y2 - y1) / 4;
    00238
    00239   /* Get the height on both sides of the tile edge.
    00240    * Avoid testing the height on the tile-center. This will fail for halftile-foundations.
    00241    */
    00242   int z1 = GetSlopeZ(x1 + dx4, y1 + dy4);
    00243   int z2 = GetSlopeZ(x2 - dx4, y2 - dy4);
    00244
    00245   if (z2 - z1 > 1) {
    00246     /* Slope up */
    00247     return _settings_game.pf.npf.npf_rail_slope_penalty;
    00248   }
    00249   return 0;
    00250   /* Should we give a bonus for slope down? Probably not, we
    00251    * could just substract that bonus from the penalty, because
    00252    * there is only one level of steepness... */
    00253 }
    00254
    00255 static uint NPFReservedTrackCost(AyStarNode *current)
    00256 {
    00257   TileIndex tile = current->tile;
    00258   TrackBits track = TrackToTrackBits(TrackdirToTrack(current->direction));
    00259   TrackBits res = GetReservedTrackbits(tile);
    00260
    00261   if (NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL) || NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_BLOCK) || ((res & track) == TRACK_BIT_NONE && !TracksOverlap(res | track))) return 0;
    00262
    00263   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
    00264     DiagDirection exitdir = TrackdirToExitdir(current->direction);
    00265     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
    00266       return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty * (GetTunnelBridgeLength(tile, GetOtherTunnelBridgeEnd(tile)) + 1);
    00267     }
    00268   }
    00269   return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty;
    00270 }
    00271
    00276 static void NPFMarkTile(TileIndex tile)
    00277 {
    00278 #ifndef NO_DEBUG_MESSAGES
    00279   if (_debug_npf_level < 1 || _networking) return;
    00280   switch (GetTileType(tile)) {
    00281     case MP_RAILWAY:
    00282       /* DEBUG: mark visited tiles by mowing the grass under them ;-) */
    00283       if (!IsRailDepot(tile)) {
    00284         SetRailGroundType(tile, RAIL_GROUND_BARREN);
    00285         MarkTileDirtyByTile(tile);
    00286       }
    00287       break;
    00288
    00289     case MP_ROAD:
    00290       if (!IsRoadDepot(tile)) {
    00291         SetRoadside(tile, ROADSIDE_BARREN);
    00292         MarkTileDirtyByTile(tile);
    00293       }
    00294       break;
    00295
    00296     default:
    00297       break;
    00298   }
    00299 #endif
    00300 }
    00301
    00302 static int32 NPFWaterPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
    00303 {
    00304   /* TileIndex tile = current->tile; */
    00305   int32 cost = 0;
    00306   Trackdir trackdir = current->direction;
    00307
    00308   cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
    00309
    00310   if (IsBuoyTile(current->tile) && IsDiagonalTrackdir(trackdir)) {
    00311     cost += _settings_game.pf.npf.npf_buoy_penalty; // A small penalty for going over buoys
    00312   }
    00313
    00314   if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction)) {
    00315     cost += _settings_game.pf.npf.npf_water_curve_penalty;
    00316   }
    00317
    00318   /* @todo More penalties? */
    00319
    00320   return cost;
    00321 }
    00322
    00323 /* Determine the cost of this node, for road tracks */
    00324 static int32 NPFRoadPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
    00325 {
    00326   TileIndex tile = current->tile;
    00327   int32 cost = 0;
    00328
    00329   /* Determine base length */
    00330   switch (GetTileType(tile)) {
    00331     case MP_TUNNELBRIDGE:
    00332       cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
    00333       break;
    00334
    00335     case MP_ROAD:
    00336       cost = NPF_TILE_LENGTH;
    00337       /* Increase the cost for level crossings */
    00338       if (IsLevelCrossing(tile)) cost += _settings_game.pf.npf.npf_crossing_penalty;
    00339       /* Increase cost for trafficlights. */
    00340       if (HasTrafficLights(tile)) cost += _settings_game.pf.npf.npf_road_trafficlight_penalty;
    00341       break;
    00342
    00343     case MP_STATION: {
    00344       cost = NPF_TILE_LENGTH;
    00345       const RoadStop *rs = RoadStop::GetByTile(tile, GetRoadStopType(tile));
    00346       if (IsDriveThroughStopTile(tile)) {
    00347         /* Increase the cost for drive-through road stops */
    00348         cost += _settings_game.pf.npf.npf_road_drive_through_penalty;
    00349         DiagDirection dir = TrackdirToExitdir(current->direction);
    00350         if (!RoadStop::IsDriveThroughRoadStopContinuation(tile, tile - TileOffsByDiagDir(dir))) {
    00351           /* When we're the first road stop in a 'queue' of them we increase
    00352            * cost based on the fill percentage of the whole queue. */
    00353           const RoadStop::Entry *entry = rs->GetEntry(dir);
    00354           cost += entry->GetOccupied() * _settings_game.pf.npf.npf_road_dt_occupied_penalty / entry->GetLength();
    00355         }
    00356       } else {
    00357         /* Increase cost for filled road stops */
    00358         cost += _settings_game.pf.npf.npf_road_bay_occupied_penalty * (!rs->IsFreeBay(0) + !rs->IsFreeBay(1)) / 2;
    00359       }
    00360       break;
    00361     }
    00362
    00363     default:
    00364       break;
    00365   }
    00366
    00367   /* Determine extra costs */
    00368
    00369   /* Check for slope */
    00370   cost += NPFSlopeCost(current);
    00371
    00372   /* Check for turns. Road vehicles only really drive diagonal, turns are
    00373    * represented by non-diagonal tracks */
    00374   if (!IsDiagonalTrackdir(current->direction)) {
    00375     cost += _settings_game.pf.npf.npf_road_curve_penalty;
    00376   }
    00377
    00378   NPFMarkTile(tile);
    00379   DEBUG(npf, 4, "Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);
    00380   return cost;
    00381 }
    00382
    00383
    00384 /* Determine the cost of this node, for railway tracks */
    00385 static int32 NPFRailPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
    00386 {
    00387   TileIndex tile = current->tile;
    00388   Trackdir trackdir = current->direction;
    00389   int32 cost = 0;
    00390   /* HACK: We create a OpenListNode manually, so we can call EndNodeCheck */
    00391   OpenListNode new_node;
    00392
    00393   /* Determine base length */
    00394   switch (GetTileType(tile)) {
    00395     case MP_TUNNELBRIDGE:
    00396       cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
    00397       break;
    00398
    00399     case MP_RAILWAY:
    00400       cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
    00401       break;
    00402
    00403     case MP_ROAD: // Railway crossing
    00404       cost = NPF_TILE_LENGTH;
    00405       break;
    00406
    00407     case MP_STATION:
    00408       /* We give a station tile a penalty. Logically we would only want to give
    00409        * station tiles that are not our destination this penalty. This would
    00410        * discourage trains to drive through busy stations. But, we can just
    00411        * give any station tile a penalty, because every possible route will get
    00412        * this penalty exactly once, on its end tile (if it's a station) and it
    00413        * will therefore not make a difference. */
    00414       cost = NPF_TILE_LENGTH + _settings_game.pf.npf.npf_rail_station_penalty;
    00415
    00416       if (IsRailWaypoint(tile)) {
    00417         NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
    00418         if (fstd->v->current_order.IsType(OT_GOTO_WAYPOINT) && GetStationIndex(tile) == fstd->v->current_order.GetDestination()) {
    00419           /* This waypoint is our destination; maybe this isn't an unreserved
    00420            * one, so check that and if so see that as the last signal being
    00421            * red. This way waypoints near stations should work better. */
    00422           const Train *train = Train::From(fstd->v);
    00423           CFollowTrackRail ft(train);
    00424           TileIndex t = tile;
    00425           Trackdir td = trackdir;
    00426           while (ft.Follow(t, td)) {
    00427             assert(t != ft.m_new_tile);
    00428             t = ft.m_new_tile;
    00429             if (KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
    00430               /* We encountered a junction; it's going to be too complex to
    00431                * handle this perfectly, so just bail out. There is no simple
    00432                * free path, so try the other possibilities. */
    00433               td = INVALID_TRACKDIR;
    00434               break;
    00435             }
    00436             td = RemoveFirstTrackdir(&ft.m_new_td_bits);
    00437             /* If this is a safe waiting position we're done searching for it */
    00438             if (IsSafeWaitingPosition(train, t, td, true, _settings_game.pf.forbid_90_deg)) break;
    00439           }
    00440           if (td == INVALID_TRACKDIR ||
    00441               !IsSafeWaitingPosition(train, t, td, true, _settings_game.pf.forbid_90_deg) ||
    00442               !IsWaitingPositionFree(train, t, td, _settings_game.pf.forbid_90_deg)) {
    00443             cost += _settings_game.pf.npf.npf_rail_lastred_penalty;
    00444           }
    00445         }
    00446       }
    00447       break;
    00448
    00449     default:
    00450       break;
    00451   }
    00452
    00453   /* Determine extra costs */
    00454
    00455   /* Check for signals */
    00456   if (IsTileType(tile, MP_RAILWAY)) {
    00457     if (HasSignalOnTrackdir(tile, trackdir)) {
    00458       SignalType sigtype = GetSignalType(tile, TrackdirToTrack(trackdir));
    00459       /* Ordinary track with signals */
    00460       if (GetSignalStateByTrackdir(tile, trackdir) == SIGNAL_STATE_RED) {
    00461         /* Signal facing us is red */
    00462         if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
    00463           /* Penalize the first signal we
    00464            * encounter, if it is red */
    00465
    00466           /* Is this a presignal exit or combo? */
    00467           if (!IsPbsSignal(sigtype)) {
    00468             if (sigtype == SIGTYPE_EXIT || sigtype == SIGTYPE_COMBO) {
    00469               /* Penalise exit and combo signals differently (heavier) */
    00470               cost += _settings_game.pf.npf.npf_rail_firstred_exit_penalty;
    00471             } else {
    00472               cost += _settings_game.pf.npf.npf_rail_firstred_penalty;
    00473             }
    00474           }
    00475         }
    00476         /* Record the state of this signal. Path signals are assumed to
    00477          * be green as the signal state of them has no meaning for this. */
    00478         NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, !IsPbsSignal(sigtype));
    00479       } else {
    00480         /* Record the state of this signal */
    00481         NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, false);
    00482       }
    00483       if (NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
    00484         if (NPFGetFlag(current, NPF_FLAG_2ND_SIGNAL)) {
    00485           NPFSetFlag(current, NPF_FLAG_3RD_SIGNAL, true);
    00486         } else {
    00487           NPFSetFlag(current, NPF_FLAG_2ND_SIGNAL, true);
    00488         }
    00489       } else {
    00490         NPFSetFlag(current, NPF_FLAG_SEEN_SIGNAL, true);
    00491       }
    00492       NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_BLOCK, !IsPbsSignal(sigtype));
    00493     }
    00494
    00495     if (HasPbsSignalOnTrackdir(tile, ReverseTrackdir(trackdir)) && !NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL)) {
    00496       cost += _settings_game.pf.npf.npf_rail_pbs_signal_back_penalty;
    00497     }
    00498   }
    00499
    00500   /* Penalise the tile if it is a target tile and the last signal was
    00501    * red */
    00502   /* HACK: We create a new_node here so we can call EndNodeCheck. Ugly as hell
    00503    * of course... */
    00504   new_node.path.node = *current;
    00505   if (as->EndNodeCheck(as, &new_node) == AYSTAR_FOUND_END_NODE && NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_RED)) {
    00506     cost += _settings_game.pf.npf.npf_rail_lastred_penalty;
    00507   }
    00508
    00509   /* Check for slope */
    00510   cost += NPFSlopeCost(current);
    00511
    00512   /* Check for turns */
    00513   if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction)) {
    00514     cost += _settings_game.pf.npf.npf_rail_curve_penalty;
    00515   }
    00516   /* TODO, with realistic acceleration, also the amount of straight track between
    00517    *      curves should be taken into account, as this affects the speed limit. */
    00518
    00519   /* Check for reverse in depot */
    00520   if (IsRailDepotTile(tile) && as->EndNodeCheck(as, &new_node) != AYSTAR_FOUND_END_NODE) {
    00521     /* Penalise any depot tile that is not the last tile in the path. This
    00522      * _should_ penalise every occurrence of reversing in a depot (and only
    00523      * that) */
    00524     cost += _settings_game.pf.npf.npf_rail_depot_reverse_penalty;
    00525   }
    00526
    00527   /* Check for occupied track */
    00528   cost += NPFReservedTrackCost(current);
    00529
    00530   NPFMarkTile(tile);
    00531   DEBUG(npf, 4, "Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);
    00532   return cost;
    00533 }
    00534
    00535 /* Will find any depot */
    00536 static int32 NPFFindDepot(AyStar *as, OpenListNode *current)
    00537 {
    00538   /* It's not worth caching the result with NPF_FLAG_IS_TARGET here as below,
    00539    * since checking the cache not that much faster than the actual check */
    00540   return IsDepotTypeTile(current->path.node.tile, (TransportType)as->user_data[NPF_TYPE]) ?
    00541     AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
    00542 }
    00543
    00545 static int32 NPFFindSafeTile(AyStar *as, OpenListNode *current)
    00546 {
    00547   const Train *v = Train::From(((NPFFindStationOrTileData *)as->user_target)->v);
    00548
    00549   return (IsSafeWaitingPosition(v, current->path.node.tile, current->path.node.direction, true, _settings_game.pf.forbid_90_deg) &&
    00550       IsWaitingPositionFree(v, current->path.node.tile, current->path.node.direction, _settings_game.pf.forbid_90_deg)) ?
    00551         AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
    00552 }
    00553
    00554 /* Will find a station identified using the NPFFindStationOrTileData */
    00555 static int32 NPFFindStationOrTile(AyStar *as, OpenListNode *current)
    00556 {
    00557   NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
    00558   AyStarNode *node = &current->path.node;
    00559   TileIndex tile = node->tile;
    00560
    00561   if (fstd->station_index == INVALID_STATION && tile == fstd->dest_coords) return AYSTAR_FOUND_END_NODE;
    00562
    00563   if (IsTileType(tile, MP_STATION) && GetStationIndex(tile) == fstd->station_index) {
    00564     if (fstd->v->type == VEH_TRAIN) return AYSTAR_FOUND_END_NODE;
    00565
    00566     assert(fstd->v->type == VEH_ROAD);
    00567     /* Only if it is a valid station *and* we can stop there */
    00568     if (GetStationType(tile) == fstd->station_type && (fstd->not_articulated || IsDriveThroughStopTile(tile))) return AYSTAR_FOUND_END_NODE;
    00569   }
    00570   return AYSTAR_DONE;
    00571 }
    00572
    00580 static const PathNode *FindSafePosition(PathNode *path, const Train *v)
    00581 {
    00582   /* If there is no signal, reserve the whole path. */
    00583   PathNode *sig = path;
    00584
    00585   for (; path->parent != NULL; path = path->parent) {
    00586     if (IsSafeWaitingPosition(v, path->node.tile, path->node.direction, true, _settings_game.pf.forbid_90_deg)) {
    00587       sig = path;
    00588     }
    00589   }
    00590
    00591   return sig;
    00592 }
    00593
    00597 static void ClearPathReservation(const PathNode *start, const PathNode *end)
    00598 {
    00599   bool first_run = true;
    00600   for (; start != end; start = start->parent) {
    00601     if (IsRailStationTile(start->node.tile) && first_run) {
    00602       SetRailStationPlatformReservation(start->node.tile, TrackdirToExitdir(start->node.direction), false);
    00603     } else {
    00604       UnreserveRailTrack(start->node.tile, TrackdirToTrack(start->node.direction));
    00605     }
    00606     first_run = false;
    00607   }
    00608 }
    00609
    00616 static void NPFSaveTargetData(AyStar *as, OpenListNode *current)
    00617 {
    00618   NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
    00619   ftd->best_trackdir = (Trackdir)current->path.node.user_data[NPF_TRACKDIR_CHOICE];
    00620   ftd->best_path_dist = current->g;
    00621   ftd->best_bird_dist = 0;
    00622   ftd->node = current->path.node;
    00623   ftd->res_okay = false;
    00624
    00625   if (as->user_target != NULL && ((NPFFindStationOrTileData*)as->user_target)->reserve_path && as->user_data[NPF_TYPE] == TRANSPORT_RAIL) {
    00626     /* Path reservation is requested. */
    00627     const Train *v = Train::From(((NPFFindStationOrTileData *)as->user_target)->v);
    00628
    00629     const PathNode *target = FindSafePosition(&current->path, v);
    00630     ftd->node = target->node;
    00631
    00632     /* If the target is a station skip to platform end. */
    00633     if (IsRailStationTile(target->node.tile)) {
    00634       DiagDirection dir = TrackdirToExitdir(target->node.direction);
    00635       uint len = Station::GetByTile(target->node.tile)->GetPlatformLength(target->node.tile, dir);
    00636       TileIndex end_tile = TILE_ADD(target->node.tile, (len - 1) * TileOffsByDiagDir(dir));
    00637
    00638       /* Update only end tile, trackdir of a station stays the same. */
    00639       ftd->node.tile = end_tile;
    00640       if (!IsWaitingPositionFree(v, end_tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
    00641       SetRailStationPlatformReservation(target->node.tile, dir, true);
    00642       SetRailStationReservation(target->node.tile, false);
    00643     } else {
    00644       if (!IsWaitingPositionFree(v, target->node.tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
    00645     }
    00646
    00647     for (const PathNode *cur = target; cur->parent != NULL; cur = cur->parent) {
    00648       if (!TryReserveRailTrack(cur->node.tile, TrackdirToTrack(cur->node.direction))) {
    00649         /* Reservation failed, undo. */
    00650         ClearPathReservation(target, cur);
    00651         return;
    00652       }
    00653     }
    00654
    00655     ftd->res_okay = true;
    00656   }
    00657 }
    00658
    00668 static bool CanEnterTileOwnerCheck(Owner owner, TileIndex tile, DiagDirection enterdir)
    00669 {
    00670   switch (GetTileType(tile)) {
    00671     case MP_RAILWAY:
    00672       return IsInfraTileUsageAllowed(VEH_TRAIN, owner, tile); // Rail tile (also rail depot)
    00673
    00674     case MP_ROAD:
    00675       /* rail-road crossing : are we looking at the railway part? */
    00676       if (IsLevelCrossing(tile) &&
    00677           DiagDirToAxis(enterdir) != GetCrossingRoadAxis(tile)) {
    00678         return IsInfraTileUsageAllowed(VEH_TRAIN, owner, tile); // Railway needs owner check, while the street is public
    00679       } else if (IsRoadDepot(tile)) { // Road depot tile
    00680         return IsInfraTileUsageAllowed(VEH_ROAD, owner, tile);
    00681       }
    00682       break;
    00683
    00684     case MP_STATION:
    00685       if (HasStationRail(tile)) { // Rail station tile/waypoint
    00686         return IsInfraTileUsageAllowed(VEH_TRAIN, owner, tile);
    00687       } else if (IsStandardRoadStopTile(tile)) { // Road station tile (but not drive-through stops)
    00688         return IsInfraTileUsageAllowed(VEH_ROAD, owner, tile);
    00689       }
    00690       break;
    00691
    00692     case MP_TUNNELBRIDGE:
    00693       if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
    00694         return IsInfraTileUsageAllowed(VEH_TRAIN, owner, tile);
    00695       }
    00696       break;
    00697
    00698     default:
    00699       break;
    00700   }
    00701
    00702   return true; // no need to check
    00703 }
    00704
    00706 static DiagDirection GetSingleTramBit(TileIndex tile)
    00707 {
    00708   if (IsNormalRoadTile(tile)) {
    00709     RoadBits rb = GetRoadBits(tile, ROADTYPE_TRAM);
    00710     switch (rb) {
    00711       case ROAD_NW: return DIAGDIR_NW;
    00712       case ROAD_SW: return DIAGDIR_SW;
    00713       case ROAD_SE: return DIAGDIR_SE;
    00714       case ROAD_NE: return DIAGDIR_NE;
    00715       default: break;
    00716     }
    00717   }
    00718   return INVALID_DIAGDIR;
    00719 }
    00720
    00731 static DiagDirection GetTileSingleEntry(TileIndex tile, TransportType type, uint subtype)
    00732 {
    00733   if (type != TRANSPORT_WATER && IsDepotTypeTile(tile, type)) return GetDepotDirection(tile, type);
    00734
    00735   if (type == TRANSPORT_ROAD) {
    00736     if (IsStandardRoadStopTile(tile)) return GetRoadStopDir(tile);
    00737     if (HasBit(subtype, ROADTYPE_TRAM)) return GetSingleTramBit(tile);
    00738   }
    00739
    00740   return INVALID_DIAGDIR;
    00741 }
    00742
    00752 static inline bool ForceReverse(TileIndex tile, DiagDirection dir, TransportType type, uint subtype)
    00753 {
    00754   DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
    00755   return single_entry != INVALID_DIAGDIR && single_entry != dir;
    00756 }
    00757
    00769 static bool CanEnterTile(TileIndex tile, DiagDirection dir, TransportType type, uint subtype, RailTypes railtypes, Owner owner)
    00770 {
    00771   /* Check tunnel entries and bridge ramps */
    00772   if (IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(tile) != dir) return false;
    00773
    00774   /* Test ownership */
    00775   if (!CanEnterTileOwnerCheck(owner, tile, dir)) return false;
    00776
    00777   /* check correct rail type (mono, maglev, etc) */
    00778   if (type == TRANSPORT_RAIL) {
    00779     RailType rail_type = GetTileRailType(tile);
    00780     if (!HasBit(railtypes, rail_type)) return false;
    00781   }
    00782
    00783   /* Depots, standard roadstops and single tram bits can only be entered from one direction */
    00784   DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
    00785   if (single_entry != INVALID_DIAGDIR && single_entry != ReverseDiagDir(dir)) return false;
    00786
    00787   return true;
    00788 }
    00789
    00801 static TrackdirBits GetDriveableTrackdirBits(TileIndex dst_tile, Trackdir src_trackdir, TransportType type, uint subtype)
    00802 {
    00803   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(dst_tile, type, subtype));
    00804
    00805   if (trackdirbits == 0 && type == TRANSPORT_ROAD && HasBit(subtype, ROADTYPE_TRAM)) {
    00806     /* GetTileTrackStatus() returns 0 for single tram bits.
    00807      * As we cannot change it there (easily) without breaking something, change it here */
    00808     switch (GetSingleTramBit(dst_tile)) {
    00809       case DIAGDIR_NE:
    00810       case DIAGDIR_SW:
    00811         trackdirbits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
    00812         break;
    00813
    00814       case DIAGDIR_NW:
    00815       case DIAGDIR_SE:
    00816         trackdirbits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
    00817         break;
    00818
    00819       default: break;
    00820     }
    00821   }
    00822
    00823   DEBUG(npf, 4, "Next node: (%d, %d) [%d], possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), dst_tile, trackdirbits);
    00824
    00825   /* Select only trackdirs we can reach from our current trackdir */
    00826   trackdirbits &= TrackdirReachesTrackdirs(src_trackdir);
    00827
    00828   /* Filter out trackdirs that would make 90 deg turns for trains */
    00829   if (_settings_game.pf.forbid_90_deg && (type == TRANSPORT_RAIL || type == TRANSPORT_WATER)) trackdirbits &= ~TrackdirCrossesTrackdirs(src_trackdir);
    00830
    00831   DEBUG(npf, 6, "After filtering: (%d, %d), possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), trackdirbits);
    00832
    00833   return trackdirbits;
    00834 }
    00835
    00836
    00837 /* Will just follow the results of GetTileTrackStatus concerning where we can
    00838  * go and where not. Uses AyStar.user_data[NPF_TYPE] as the transport type and
    00839  * an argument to GetTileTrackStatus. Will skip tunnels, meaning that the
    00840  * entry and exit are neighbours. Will fill
    00841  * AyStarNode.user_data[NPF_TRACKDIR_CHOICE] with an appropriate value, and
    00842  * copy AyStarNode.user_data[NPF_NODE_FLAGS] from the parent */
    00843 static void NPFFollowTrack(AyStar *aystar, OpenListNode *current)
    00844 {
    00845   /* We leave src_tile on track src_trackdir in direction src_exitdir */
    00846   Trackdir src_trackdir = current->path.node.direction;
    00847   TileIndex src_tile = current->path.node.tile;
    00848   DiagDirection src_exitdir = TrackdirToExitdir(src_trackdir);
    00849
    00850   /* Is src_tile valid, and can be used?
    00851    * When choosing track on a junction src_tile is the tile neighboured to the junction wrt. exitdir.
    00852    * But we must not check the validity of this move, as src_tile is totally unrelated to the move, if a roadvehicle reversed on a junction. */
    00853   bool ignore_src_tile = (current->path.parent == NULL && NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_START_TILE));
    00854
    00855   /* Information about the vehicle: TransportType (road/rail/water) and SubType (compatible rail/road types) */
    00856   TransportType type = (TransportType)aystar->user_data[NPF_TYPE];
    00857   uint subtype = aystar->user_data[NPF_SUB_TYPE];
    00858
    00859   /* Initialize to 0, so we can jump out (return) somewhere an have no neighbours */
    00860   aystar->num_neighbours = 0;
    00861   DEBUG(npf, 4, "Expanding: (%d, %d, %d) [%d]", TileX(src_tile), TileY(src_tile), src_trackdir, src_tile);
    00862
    00863   /* We want to determine the tile we arrive, and which choices we have there */
    00864   TileIndex dst_tile;
    00865   TrackdirBits trackdirbits;
    00866
    00867   /* Find dest tile */
    00868   if (ignore_src_tile) {
    00869     /* Do not perform any checks that involve src_tile */
    00870     dst_tile = src_tile + TileOffsByDiagDir(src_exitdir);
    00871     trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
    00872   } else if (IsTileType(src_tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(src_tile) == src_exitdir) {
    00873     /* We drive through the wormhole and arrive on the other side */
    00874     dst_tile = GetOtherTunnelBridgeEnd(src_tile);
    00875     trackdirbits = TrackdirToTrackdirBits(src_trackdir);
    00876   } else if (ForceReverse(src_tile, src_exitdir, type, subtype)) {
    00877     /* We can only reverse on this tile */
    00878     dst_tile = src_tile;
    00879     src_trackdir = ReverseTrackdir(src_trackdir);
    00880     trackdirbits = TrackdirToTrackdirBits(src_trackdir);
    00881   } else {
    00882     /* We leave src_tile in src_exitdir and reach dst_tile */
    00883     dst_tile = AddTileIndexDiffCWrap(src_tile, TileIndexDiffCByDiagDir(src_exitdir));
    00884
    00885     if (dst_tile != INVALID_TILE && !CanEnterTile(dst_tile, src_exitdir, type, subtype, (RailTypes)aystar->user_data[NPF_RAILTYPES], (Owner)aystar->user_data[NPF_OWNER])) dst_tile = INVALID_TILE;
    00886
    00887     if (dst_tile == INVALID_TILE) {
    00888       /* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
    00889       if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
    00890
    00891       dst_tile = src_tile;
    00892       src_trackdir = ReverseTrackdir(src_trackdir);
    00893     }
    00894
    00895     trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
    00896
    00897     if (trackdirbits == 0) {
    00898       /* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
    00899       if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
    00900
    00901       dst_tile = src_tile;
    00902       src_trackdir = ReverseTrackdir(src_trackdir);
    00903
    00904       trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
    00905     }
    00906   }
    00907
    00908   if (NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_RESERVED)) {
    00909     /* Mask out any reserved tracks. */
    00910     TrackBits reserved = GetReservedTrackbits(dst_tile);
    00911     trackdirbits &= ~TrackBitsToTrackdirBits(reserved);
    00912
    00913     Track t;
    00914     FOR_EACH_SET_TRACK(t, TrackdirBitsToTrackBits(trackdirbits)) {
    00915       if (TracksOverlap(reserved | TrackToTrackBits(t))) trackdirbits &= ~TrackToTrackdirBits(t);
    00916     }
    00917   }
    00918
    00919   /* Enumerate possible track */
    00920   uint i = 0;
    00921   while (trackdirbits != 0) {
    00922     Trackdir dst_trackdir = RemoveFirstTrackdir(&trackdirbits);
    00923     DEBUG(npf, 5, "Expanded into trackdir: %d, remaining trackdirs: 0x%X", dst_trackdir, trackdirbits);
    00924
    00925     /* Tile with signals? */
    00926     if (IsTileType(dst_tile, MP_RAILWAY) && GetRailTileType(dst_tile) == RAIL_TILE_SIGNALS) {
    00927       if (HasSignalOnTrackdir(dst_tile, ReverseTrackdir(dst_trackdir)) && !HasSignalOnTrackdir(dst_tile, dst_trackdir) && IsOnewaySignal(dst_tile, TrackdirToTrack(dst_trackdir))) {
    00928         /* If there's a one-way signal not pointing towards us, stop going in this direction. */
    00929         break;
    00930       }
    00931     }
    00932     {
    00933       /* We've found ourselves a neighbour :-) */
    00934       AyStarNode *neighbour = &aystar->neighbours[i];
    00935       neighbour->tile = dst_tile;
    00936       neighbour->direction = dst_trackdir;
    00937       /* Save user data */
    00938       neighbour->user_data[NPF_NODE_FLAGS] = current->path.node.user_data[NPF_NODE_FLAGS];
    00939       NPFFillTrackdirChoice(neighbour, current);
    00940     }
    00941     i++;
    00942   }
    00943   aystar->num_neighbours = i;
    00944 }
    00945
    00946 /*
    00947  * Plan a route to the specified target (which is checked by target_proc),
    00948  * from start1 and if not NULL, from start2 as well. The type of transport we
    00949  * are checking is in type. reverse_penalty is applied to all routes that
    00950  * originate from the second start node.
    00951  * When we are looking for one specific target (optionally multiple tiles), we
    00952  * should use a good heuristic to perform aystar search. When we search for
    00953  * multiple targets that are spread around, we should perform a breadth first
    00954  * search by specifiying CalcZero as our heuristic.
    00955  */
    00956 static NPFFoundTargetData NPFRouteInternal(AyStarNode *start1, bool ignore_start_tile1, AyStarNode *start2, bool ignore_start_tile2, NPFFindStationOrTileData *target, AyStar_EndNodeCheck target_proc, AyStar_CalculateH heuristic_proc, TransportType type, uint sub_type, Owner owner, RailTypes railtypes, uint reverse_penalty)
    00957 {
    00958   int r;
    00959   NPFFoundTargetData result;
    00960
    00961   /* Initialize procs */
    00962   _npf_aystar.CalculateH = heuristic_proc;
    00963   _npf_aystar.EndNodeCheck = target_proc;
    00964   _npf_aystar.FoundEndNode = NPFSaveTargetData;
    00965   _npf_aystar.GetNeighbours = NPFFollowTrack;
    00966   switch (type) {
    00967     default: NOT_REACHED();
    00968     case TRANSPORT_RAIL:  _npf_aystar.CalculateG = NPFRailPathCost;  break;
    00969     case TRANSPORT_ROAD:  _npf_aystar.CalculateG = NPFRoadPathCost;  break;
    00970     case TRANSPORT_WATER: _npf_aystar.CalculateG = NPFWaterPathCost; break;
    00971   }
    00972
    00973   /* Initialize Start Node(s) */
    00974   start1->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
    00975   start1->user_data[NPF_NODE_FLAGS] = 0;
    00976   NPFSetFlag(start1, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile1);
    00977   _npf_aystar.AddStartNode(start1, 0);
    00978   if (start2 != NULL) {
    00979     start2->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
    00980     start2->user_data[NPF_NODE_FLAGS] = 0;
    00981     NPFSetFlag(start2, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile2);
    00982     NPFSetFlag(start2, NPF_FLAG_REVERSE, true);
    00983     _npf_aystar.AddStartNode(start2, reverse_penalty);
    00984   }
    00985
    00986   /* Initialize result */
    00987   result.best_bird_dist = UINT_MAX;
    00988   result.best_path_dist = UINT_MAX;
    00989   result.best_trackdir  = INVALID_TRACKDIR;
    00990   result.node.tile      = INVALID_TILE;
    00991   result.res_okay       = false;
    00992   _npf_aystar.user_path = &result;
    00993
    00994   /* Initialize target */
    00995   _npf_aystar.user_target = target;
    00996
    00997   /* Initialize user_data */
    00998   _npf_aystar.user_data[NPF_TYPE] = type;
    00999   _npf_aystar.user_data[NPF_SUB_TYPE] = sub_type;
    01000   _npf_aystar.user_data[NPF_OWNER] = owner;
    01001   _npf_aystar.user_data[NPF_RAILTYPES] = railtypes;
    01002
    01003   /* GO! */
    01004   r = _npf_aystar.Main();
    01005   assert(r != AYSTAR_STILL_BUSY);
    01006
    01007   if (result.best_bird_dist != 0) {
    01008     if (target != NULL) {
    01009       DEBUG(npf, 1, "Could not find route to tile 0x%X from 0x%X.", target->dest_coords, start1->tile);
    01010     } else {
    01011       /* Assumption: target == NULL, so we are looking for a depot */
    01012       DEBUG(npf, 1, "Could not find route to a depot from tile 0x%X.", start1->tile);
    01013     }
    01014
    01015   }
    01016   return result;
    01017 }
    01018
    01019 /* Will search as below, but with two start nodes, the second being the
    01020  * reverse. Look at the NPF_FLAG_REVERSE flag in the result node to see which
    01021  * direction was taken (NPFGetFlag(result.node, NPF_FLAG_REVERSE)) */
    01022 static NPFFoundTargetData NPFRouteToStationOrTileTwoWay(TileIndex tile1, Trackdir trackdir1, bool ignore_start_tile1, TileIndex tile2, Trackdir trackdir2, bool ignore_start_tile2, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes)
    01023 {
    01024   AyStarNode start1;
    01025   AyStarNode start2;
    01026
    01027   start1.tile = tile1;
    01028   start2.tile = tile2;
    01029   /* We set this in case the target is also the start tile, we will just
    01030    * return a not found then */
    01031   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
    01032   start1.direction = trackdir1;
    01033   start2.direction = trackdir2;
    01034   start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
    01035
    01036   return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, target, NPFFindStationOrTile, NPFCalcStationOrTileHeuristic, type, sub_type, owner, railtypes, 0);
    01037 }
    01038
    01039 /* Will search from the given tile and direction, for a route to the given
    01040  * station for the given transport type. See the declaration of
    01041  * NPFFoundTargetData above for the meaning of the result. */
    01042 static NPFFoundTargetData NPFRouteToStationOrTile(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes)
    01043 {
    01044   return NPFRouteToStationOrTileTwoWay(tile, trackdir, ignore_start_tile, INVALID_TILE, INVALID_TRACKDIR, false, target, type, sub_type, owner, railtypes);
    01045 }
    01046
    01047 /* Search using breadth first. Good for little track choice and inaccurate
    01048  * heuristic, such as railway/road with two start nodes, the second being the reverse. Call
    01049  * NPFGetFlag(result.node, NPF_FLAG_REVERSE) to see from which node the path
    01050  * orginated. All pathfs from the second node will have the given
    01051  * reverse_penalty applied (NPF_TILE_LENGTH is the equivalent of one full
    01052  * tile).
    01053  */
    01054 static NPFFoundTargetData NPFRouteToDepotBreadthFirstTwoWay(TileIndex tile1, Trackdir trackdir1, bool ignore_start_tile1, TileIndex tile2, Trackdir trackdir2, bool ignore_start_tile2, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes, uint reverse_penalty)
    01055 {
    01056   AyStarNode start1;
    01057   AyStarNode start2;
    01058
    01059   start1.tile = tile1;
    01060   start2.tile = tile2;
    01061   /* We set this in case the target is also the start tile, we will just
    01062    * return a not found then */
    01063   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
    01064   start1.direction = trackdir1;
    01065   start2.direction = trackdir2;
    01066   start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
    01067
    01068   /* perform a breadth first search. Target is NULL,
    01069    * since we are just looking for any depot...*/
    01070   return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, target, NPFFindDepot, NPFCalcZero, type, sub_type, owner, railtypes, reverse_penalty);
    01071 }
    01072
    01073 void InitializeNPF()
    01074 {
    01075   static bool first_init = true;
    01076   if (first_init) {
    01077     first_init = false;
    01078     _npf_aystar.Init(NPFHash, NPF_HASH_SIZE);
    01079   } else {
    01080     _npf_aystar.Clear();
    01081   }
    01082   _npf_aystar.loops_per_tick = 0;
    01083   _npf_aystar.max_path_cost = 0;
    01084   //_npf_aystar.max_search_nodes = 0;
    01085   /* We will limit the number of nodes for now, until we have a better
    01086    * solution to really fix performance */
    01087   _npf_aystar.max_search_nodes = _settings_game.pf.npf.npf_max_search_nodes;
    01088 }
    01089
    01090 static void NPFFillWithOrderData(NPFFindStationOrTileData *fstd, const Vehicle *v, bool reserve_path = false)
    01091 {
    01092   /* Ships don't really reach their stations, but the tile in front. So don't
    01093    * save the station id for ships. For roadvehs we don't store it either,
    01094    * because multistop depends on vehicles actually reaching the exact
    01095    * dest_tile, not just any stop of that station.
    01096    * So only for train orders to stations we fill fstd->station_index, for all
    01097    * others only dest_coords */
    01098   if (v->type != VEH_SHIP && (v->current_order.IsType(OT_GOTO_STATION) || v->current_order.IsType(OT_GOTO_WAYPOINT))) {
    01099     assert(v->IsGroundVehicle());
    01100     fstd->station_index = v->current_order.GetDestination();
    01101     fstd->station_type = (v->type == VEH_TRAIN) ? (v->current_order.IsType(OT_GOTO_STATION) ? STATION_RAIL : STATION_WAYPOINT) : (RoadVehicle::From(v)->IsBus() ? STATION_BUS : STATION_TRUCK);
    01102     fstd->not_articulated = v->type == VEH_ROAD && !RoadVehicle::From(v)->HasArticulatedPart();
    01103     /* Let's take the closest tile of the station as our target for vehicles */
    01104     fstd->dest_coords = CalcClosestStationTile(fstd->station_index, v->tile, fstd->station_type);
    01105   } else {
    01106     fstd->dest_coords = v->dest_tile;
    01107     fstd->station_index = INVALID_STATION;
    01108   }
    01109   fstd->reserve_path = reserve_path;
    01110   fstd->v = v;
    01111 }
    01112
    01113 /*** Road vehicles ***/
    01114
    01115 FindDepotData NPFRoadVehicleFindNearestDepot(const RoadVehicle *v, int max_penalty)
    01116 {
    01117   Trackdir trackdir = v->GetVehicleTrackdir();
    01118
    01119   NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, v->tile, ReverseTrackdir(trackdir), false, NULL, TRANSPORT_ROAD, v->compatible_roadtypes, v->owner, INVALID_RAILTYPES, 0);
    01120
    01121   if (ftd.best_bird_dist != 0) return FindDepotData();
    01122
    01123   /* Found target */
    01124   /* Our caller expects a number of tiles, so we just approximate that
    01125    * number by this. It might not be completely what we want, but it will
    01126    * work for now :-) We can possibly change this when the old pathfinder
    01127    * is removed. */
    01128   return FindDepotData(ftd.node.tile, ftd.best_path_dist);
    01129 }
    01130
    01131 Trackdir NPFRoadVehicleChooseTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool &path_found)
    01132 {
    01133   NPFFindStationOrTileData fstd;
    01134
    01135   NPFFillWithOrderData(&fstd, v);
    01136   Trackdir trackdir = DiagDirToDiagTrackdir(enterdir);
    01137
    01138   NPFFoundTargetData ftd = NPFRouteToStationOrTile(tile - TileOffsByDiagDir(enterdir), trackdir, true, &fstd, TRANSPORT_ROAD, v->compatible_roadtypes, v->owner, INVALID_RAILTYPES);
    01139   if (ftd.best_trackdir == INVALID_TRACKDIR) {
    01140     /* We are already at our target. Just do something
    01141      * @todo: maybe display error?
    01142      * @todo: go straight ahead if possible? */
    01143     path_found = true;
    01144     return (Trackdir)FindFirstBit2x64(trackdirs);
    01145   }
    01146
    01147   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
    01148    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
    01149    * we did not find our target, but ftd.best_trackdir contains the direction leading
    01150    * to the tile closest to our target. */
    01151   path_found = (ftd.best_bird_dist == 0);
    01152   return ftd.best_trackdir;
    01153 }
    01154
    01155 /*** Ships ***/
    01156
    01157 Track NPFShipChooseTrack(const Ship *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found)
    01158 {
    01159   NPFFindStationOrTileData fstd;
    01160   Trackdir trackdir = v->GetVehicleTrackdir();
    01161   assert(trackdir != INVALID_TRACKDIR); // Check that we are not in a depot
    01162
    01163   NPFFillWithOrderData(&fstd, v);
    01164
    01165   NPFFoundTargetData ftd = NPFRouteToStationOrTile(tile - TileOffsByDiagDir(enterdir), trackdir, true, &fstd, TRANSPORT_WATER, 0, v->owner, INVALID_RAILTYPES);
    01166
    01167   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
    01168    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
    01169    * we did not find our target, but ftd.best_trackdir contains the direction leading
    01170    * to the tile closest to our target. */
    01171   path_found = (ftd.best_bird_dist == 0);
    01172   if (ftd.best_trackdir == 0xff) return INVALID_TRACK;
    01173   return TrackdirToTrack(ftd.best_trackdir);
    01174 }
    01175
    01176 /*** Trains ***/
    01177
    01178 FindDepotData NPFTrainFindNearestDepot(const Train *v, int max_penalty)
    01179 {
    01180   const Train *last = v->Last();
    01181   Trackdir trackdir = v->GetVehicleTrackdir();
    01182   Trackdir trackdir_rev = ReverseTrackdir(last->GetVehicleTrackdir());
    01183   NPFFindStationOrTileData fstd;
    01184   fstd.v = v;
    01185   fstd.reserve_path = false;
    01186
    01187   assert(trackdir != INVALID_TRACKDIR);
    01188   NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, &fstd, TRANSPORT_RAIL, 0, v->owner, v->compatible_railtypes, NPF_INFINITE_PENALTY);
    01189   if (ftd.best_bird_dist != 0) return FindDepotData();
    01190
    01191   /* Found target */
    01192   /* Our caller expects a number of tiles, so we just approximate that
    01193    * number by this. It might not be completely what we want, but it will
    01194    * work for now :-) We can possibly change this when the old pathfinder
    01195    * is removed. */
    01196   return FindDepotData(ftd.node.tile, ftd.best_path_dist, NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE));
    01197 }
    01198
    01199 bool NPFTrainFindNearestSafeTile(const Train *v, TileIndex tile, Trackdir trackdir, bool override_railtype)
    01200 {
    01201   assert(v->type == VEH_TRAIN);
    01202
    01203   NPFFindStationOrTileData fstd;
    01204   fstd.v = v;
    01205   fstd.reserve_path = true;
    01206
    01207   AyStarNode start1;
    01208   start1.tile = tile;
    01209   /* We set this in case the target is also the start tile, we will just
    01210    * return a not found then */
    01211   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
    01212   start1.direction = trackdir;
    01213   NPFSetFlag(&start1, NPF_FLAG_IGNORE_RESERVED, true);
    01214
    01215   RailTypes railtypes = v->compatible_railtypes;
    01216   if (override_railtype) railtypes |= GetRailTypeInfo(v->railtype)->compatible_railtypes;
    01217
    01218   /* perform a breadth first search. Target is NULL,
    01219    * since we are just looking for any safe tile...*/
    01220   return NPFRouteInternal(&start1, true, NULL, false, &fstd, NPFFindSafeTile, NPFCalcZero, TRANSPORT_RAIL, 0, v->owner, railtypes, 0).res_okay;
    01221 }
    01222
    01223 bool NPFTrainCheckReverse(const Train *v)
    01224 {
    01225   NPFFindStationOrTileData fstd;
    01226   NPFFoundTargetData ftd;
    01227   const Train *last = v->Last();
    01228
    01229   NPFFillWithOrderData(&fstd, v);
    01230
    01231   Trackdir trackdir = v->GetVehicleTrackdir();
    01232   Trackdir trackdir_rev = ReverseTrackdir(last->GetVehicleTrackdir());
    01233   assert(trackdir != INVALID_TRACKDIR);
    01234   assert(trackdir_rev != INVALID_TRACKDIR);
    01235
    01236   ftd = NPFRouteToStationOrTileTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, &fstd, TRANSPORT_RAIL, 0, v->owner, v->compatible_railtypes);
    01237   /* If we didn't find anything, just keep on going straight ahead, otherwise take the reverse flag */
    01238   return ftd.best_bird_dist != 0 && NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE);
    01239 }
    01240
    01241 Track NPFTrainChooseTrack(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool reserve_track, struct PBSTileInfo *target)
    01242 {
    01243   NPFFindStationOrTileData fstd;
    01244   NPFFillWithOrderData(&fstd, v, reserve_track);
    01245
    01246   PBSTileInfo origin = FollowTrainReservation(v);
    01247   assert(IsValidTrackdir(origin.trackdir));
    01248
    01249   NPFFoundTargetData ftd = NPFRouteToStationOrTile(origin.tile, origin.trackdir, true, &fstd, TRANSPORT_RAIL, 0, v->owner, v->compatible_railtypes);
    01250
    01251   if (target != NULL) {
    01252     target->tile = ftd.node.tile;
    01253     target->trackdir = (Trackdir)ftd.node.direction;
    01254     target->okay = ftd.res_okay;
    01255   }
    01256
    01257   if (ftd.best_trackdir == INVALID_TRACKDIR) {
    01258     /* We are already at our target. Just do something
    01259      * @todo maybe display error?
    01260      * @todo: go straight ahead if possible? */
    01261     path_found = true;
    01262     return FindFirstTrack(tracks);
    01263   }
    01264
    01265   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
    01266    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
    01267    * we did not find our target, but ftd.best_trackdir contains the direction leading
    01268    * to the tile closest to our target. */
    01269   path_found = (ftd.best_bird_dist == 0);
    01270   /* Discard enterdir information, making it a normal track */
    01271   return TrackdirToTrack(ftd.best_trackdir);
    01272 }