npf.cpp

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00001 /* $Id: npf.cpp 18809 2010-01-15 16:41:15Z rubidium $ */
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 "../../landscape.h"
00015 #include "../../network/network.h"
00016 #include "../../functions.h"
00017 #include "../../ship.h"
00018 #include "../../roadstop_base.h"
00019 #include "../pathfinder_func.h"
00020 #include "../pathfinder_type.h"
00021 #include "../follow_track.hpp"
00022 #include "aystar.h"
00023 
00024 enum {
00025   NPF_HASH_BITS = 12, 
00026   /* Do no change below values */
00027   NPF_HASH_SIZE = 1 << NPF_HASH_BITS,
00028   NPF_HASH_HALFBITS = NPF_HASH_BITS / 2,
00029   NPF_HASH_HALFMASK = (1 << NPF_HASH_HALFBITS) - 1
00030 };
00031 
00032 /* Meant to be stored in AyStar.targetdata */
00033 struct NPFFindStationOrTileData {
00034   TileIndex dest_coords;    
00035   StationID station_index;  
00036   bool reserve_path;        
00037   StationType station_type; 
00038   bool not_articulated;     
00039   const Vehicle *v;         
00040 };
00041 
00042 /* Indices into AyStar.userdata[] */
00043 enum {
00044   NPF_TYPE = 0,  
00045   NPF_SUB_TYPE,  
00046   NPF_OWNER,     
00047   NPF_RAILTYPES, 
00048 };
00049 
00050 /* Indices into AyStarNode.userdata[] */
00051 enum {
00052   NPF_TRACKDIR_CHOICE = 0, 
00053   NPF_NODE_FLAGS,
00054 };
00055 
00056 /* Flags for AyStarNode.userdata[NPF_NODE_FLAGS]. Use NPFSetFlag() and NPFGetFlag() to use them. */
00057 enum NPFNodeFlag {
00058   NPF_FLAG_SEEN_SIGNAL,       
00059   NPF_FLAG_2ND_SIGNAL,        
00060   NPF_FLAG_3RD_SIGNAL,        
00061   NPF_FLAG_REVERSE,           
00062   NPF_FLAG_LAST_SIGNAL_RED,   
00063   NPF_FLAG_LAST_SIGNAL_BLOCK, 
00064   NPF_FLAG_IGNORE_START_TILE, 
00065   NPF_FLAG_TARGET_RESERVED,   
00066   NPF_FLAG_IGNORE_RESERVED,   
00067 };
00068 
00069 /* Meant to be stored in AyStar.userpath */
00070 struct NPFFoundTargetData {
00071   uint best_bird_dist;    
00072   uint best_path_dist;    
00073   Trackdir best_trackdir; 
00074   AyStarNode node;        
00075   bool res_okay;          
00076 };
00077 
00078 static AyStar _npf_aystar;
00079 
00080 /* The cost of each trackdir. A diagonal piece is the full NPF_TILE_LENGTH,
00081  * the shorter piece is sqrt(2)/2*NPF_TILE_LENGTH =~ 0.7071
00082  */
00083 #define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)
00084 static const uint _trackdir_length[TRACKDIR_END] = {
00085   NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH,
00086   0, 0,
00087   NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH
00088 };
00089 
00093 static inline bool NPFGetFlag(const AyStarNode *node, NPFNodeFlag flag)
00094 {
00095   return HasBit(node->user_data[NPF_NODE_FLAGS], flag);
00096 }
00097 
00101 static inline void NPFSetFlag(AyStarNode *node, NPFNodeFlag flag, bool value)
00102 {
00103   SB(node->user_data[NPF_NODE_FLAGS], flag, 1, value);
00104 }
00105 
00112 static uint NPFDistanceTrack(TileIndex t0, TileIndex t1)
00113 {
00114   const uint dx = Delta(TileX(t0), TileX(t1));
00115   const uint dy = Delta(TileY(t0), TileY(t1));
00116 
00117   const uint straightTracks = 2 * min(dx, dy); // The number of straight (not full length) tracks
00118   /* OPTIMISATION:
00119    * Original: diagTracks = max(dx, dy) - min(dx,dy);
00120    * Proof:
00121    * (dx+dy) - straightTracks  == (min + max) - straightTracks = min + max - 2 * min = max - min */
00122   const uint diagTracks = dx + dy - straightTracks; // The number of diagonal (full tile length) tracks.
00123 
00124   /* Don't factor out NPF_TILE_LENGTH below, this will round values and lose
00125    * precision */
00126   return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;
00127 }
00128 
00129 
00130 #if 0
00131 static uint NTPHash(uint key1, uint key2)
00132 {
00133   /* This function uses the old hash, which is fixed on 10 bits (1024 buckets) */
00134   return PATHFIND_HASH_TILE(key1);
00135 }
00136 #endif
00137 
00145 static uint NPFHash(uint key1, uint key2)
00146 {
00147   /* TODO: think of a better hash? */
00148   uint part1 = TileX(key1) & NPF_HASH_HALFMASK;
00149   uint part2 = TileY(key1) & NPF_HASH_HALFMASK;
00150 
00151   assert(IsValidTrackdir((Trackdir)key2));
00152   assert(IsValidTile(key1));
00153   return ((part1 << NPF_HASH_HALFBITS | part2) + (NPF_HASH_SIZE * key2 / TRACKDIR_END)) % NPF_HASH_SIZE;
00154 }
00155 
00156 static int32 NPFCalcZero(AyStar *as, AyStarNode *current, OpenListNode *parent)
00157 {
00158   return 0;
00159 }
00160 
00161 /* Calcs the heuristic to the target station or tile. For train stations, it
00162  * takes into account the direction of approach.
00163  */
00164 static int32 NPFCalcStationOrTileHeuristic(AyStar *as, AyStarNode *current, OpenListNode *parent)
00165 {
00166   NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
00167   NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
00168   TileIndex from = current->tile;
00169   TileIndex to = fstd->dest_coords;
00170   uint dist;
00171 
00172   /* for train-stations, we are going to aim for the closest station tile */
00173   if (as->user_data[NPF_TYPE] != TRANSPORT_WATER && fstd->station_index != INVALID_STATION)
00174     to = CalcClosestStationTile(fstd->station_index, from, fstd->station_type);
00175 
00176   if (as->user_data[NPF_TYPE] == TRANSPORT_ROAD) {
00177     /* Since roads only have diagonal pieces, we use manhattan distance here */
00178     dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;
00179   } else {
00180     /* Ships and trains can also go diagonal, so the minimum distance is shorter */
00181     dist = NPFDistanceTrack(from, to);
00182   }
00183 
00184   DEBUG(npf, 4, "Calculating H for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), dist);
00185 
00186   if (dist < ftd->best_bird_dist) {
00187     ftd->best_bird_dist = dist;
00188     ftd->best_trackdir = (Trackdir)current->user_data[NPF_TRACKDIR_CHOICE];
00189   }
00190   return dist;
00191 }
00192 
00193 
00194 /* Fills AyStarNode.user_data[NPF_TRACKDIRCHOICE] with the chosen direction to
00195  * get here, either getting it from the current choice or from the parent's
00196  * choice */
00197 static void NPFFillTrackdirChoice(AyStarNode *current, OpenListNode *parent)
00198 {
00199   if (parent->path.parent == NULL) {
00200     Trackdir trackdir = current->direction;
00201     /* This is a first order decision, so we'd better save the
00202      * direction we chose */
00203     current->user_data[NPF_TRACKDIR_CHOICE] = trackdir;
00204     DEBUG(npf, 6, "Saving trackdir: 0x%X", trackdir);
00205   } else {
00206     /* We've already made the decision, so just save our parent's decision */
00207     current->user_data[NPF_TRACKDIR_CHOICE] = parent->path.node.user_data[NPF_TRACKDIR_CHOICE];
00208   }
00209 }
00210 
00211 /* Will return the cost of the tunnel. If it is an entry, it will return the
00212  * cost of that tile. If the tile is an exit, it will return the tunnel length
00213  * including the exit tile. Requires that this is a Tunnel tile */
00214 static uint NPFTunnelCost(AyStarNode *current)
00215 {
00216   DiagDirection exitdir = TrackdirToExitdir(current->direction);
00217   TileIndex tile = current->tile;
00218   if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
00219     /* We just popped out if this tunnel, since were
00220      * facing the tunnel exit */
00221     return NPF_TILE_LENGTH * (GetTunnelBridgeLength(current->tile, GetOtherTunnelEnd(current->tile)) + 1);
00222     /* @todo: Penalty for tunnels? */
00223   } else {
00224     /* We are entering the tunnel, the enter tile is just a
00225      * straight track */
00226     return NPF_TILE_LENGTH;
00227   }
00228 }
00229 
00230 static inline uint NPFBridgeCost(AyStarNode *current)
00231 {
00232   return NPF_TILE_LENGTH * GetTunnelBridgeLength(current->tile, GetOtherBridgeEnd(current->tile));
00233 }
00234 
00235 static uint NPFSlopeCost(AyStarNode *current)
00236 {
00237   TileIndex next = current->tile + TileOffsByDiagDir(TrackdirToExitdir(current->direction));
00238 
00239   /* Get center of tiles */
00240   int x1 = TileX(current->tile) * TILE_SIZE + TILE_SIZE / 2;
00241   int y1 = TileY(current->tile) * TILE_SIZE + TILE_SIZE / 2;
00242   int x2 = TileX(next) * TILE_SIZE + TILE_SIZE / 2;
00243   int y2 = TileY(next) * TILE_SIZE + TILE_SIZE / 2;
00244 
00245   int dx4 = (x2 - x1) / 4;
00246   int dy4 = (y2 - y1) / 4;
00247 
00248   /* Get the height on both sides of the tile edge.
00249    * Avoid testing the height on the tile-center. This will fail for halftile-foundations.
00250    */
00251   int z1 = GetSlopeZ(x1 + dx4, y1 + dy4);
00252   int z2 = GetSlopeZ(x2 - dx4, y2 - dy4);
00253 
00254   if (z2 - z1 > 1) {
00255     /* Slope up */
00256     return _settings_game.pf.npf.npf_rail_slope_penalty;
00257   }
00258   return 0;
00259   /* Should we give a bonus for slope down? Probably not, we
00260    * could just substract that bonus from the penalty, because
00261    * there is only one level of steepness... */
00262 }
00263 
00264 static uint NPFReservedTrackCost(AyStarNode *current)
00265 {
00266   TileIndex tile = current->tile;
00267   TrackBits track = TrackToTrackBits(TrackdirToTrack(current->direction));
00268   TrackBits res = GetReservedTrackbits(tile);
00269 
00270   if (NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL) || NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_BLOCK) || ((res & track) == TRACK_BIT_NONE && !TracksOverlap(res | track))) return 0;
00271 
00272   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
00273     DiagDirection exitdir = TrackdirToExitdir(current->direction);
00274     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
00275       return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty * (GetTunnelBridgeLength(tile, GetOtherTunnelBridgeEnd(tile)) + 1);
00276     }
00277   }
00278   return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty;
00279 }
00280 
00285 static void NPFMarkTile(TileIndex tile)
00286 {
00287 #ifndef NO_DEBUG_MESSAGES
00288   if (_debug_npf_level < 1 || _networking) return;
00289   switch (GetTileType(tile)) {
00290     case MP_RAILWAY:
00291       /* DEBUG: mark visited tiles by mowing the grass under them ;-) */
00292       if (!IsRailDepot(tile)) {
00293         SetRailGroundType(tile, RAIL_GROUND_BARREN);
00294         MarkTileDirtyByTile(tile);
00295       }
00296       break;
00297 
00298     case MP_ROAD:
00299       if (!IsRoadDepot(tile)) {
00300         SetRoadside(tile, ROADSIDE_BARREN);
00301         MarkTileDirtyByTile(tile);
00302       }
00303       break;
00304 
00305     default:
00306       break;
00307   }
00308 #endif
00309 }
00310 
00311 static int32 NPFWaterPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
00312 {
00313   /* TileIndex tile = current->tile; */
00314   int32 cost = 0;
00315   Trackdir trackdir = current->direction;
00316 
00317   cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
00318 
00319   if (IsBuoyTile(current->tile) && IsDiagonalTrackdir(trackdir))
00320     cost += _settings_game.pf.npf.npf_buoy_penalty; // A small penalty for going over buoys
00321 
00322   if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction))
00323     cost += _settings_game.pf.npf.npf_water_curve_penalty;
00324 
00325   /* @todo More penalties? */
00326 
00327   return cost;
00328 }
00329 
00330 /* Determine the cost of this node, for road tracks */
00331 static int32 NPFRoadPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
00332 {
00333   TileIndex tile = current->tile;
00334   int32 cost = 0;
00335 
00336   /* Determine base length */
00337   switch (GetTileType(tile)) {
00338     case MP_TUNNELBRIDGE:
00339       cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
00340       break;
00341 
00342     case MP_ROAD:
00343       cost = NPF_TILE_LENGTH;
00344       /* Increase the cost for level crossings */
00345       if (IsLevelCrossing(tile)) cost += _settings_game.pf.npf.npf_crossing_penalty;
00346       break;
00347 
00348     case MP_STATION: {
00349       cost = NPF_TILE_LENGTH;
00350       const RoadStop *rs = RoadStop::GetByTile(tile, GetRoadStopType(tile));
00351       if (IsDriveThroughStopTile(tile)) {
00352         /* Increase the cost for drive-through road stops */
00353         cost += _settings_game.pf.npf.npf_road_drive_through_penalty;
00354         DiagDirection dir = TrackdirToExitdir(current->direction);
00355         if (!RoadStop::IsDriveThroughRoadStopContinuation(tile, tile - TileOffsByDiagDir(dir))) {
00356           /* When we're the first road stop in a 'queue' of them we increase
00357            * cost based on the fill percentage of the whole queue. */
00358           const RoadStop::Entry *entry = rs->GetEntry(dir);
00359           cost += entry->GetOccupied() * _settings_game.pf.npf.npf_road_dt_occupied_penalty / entry->GetLength();
00360         }
00361       } else {
00362         /* Increase cost for filled road stops */
00363         cost += _settings_game.pf.npf.npf_road_bay_occupied_penalty * (!rs->IsFreeBay(0) + !rs->IsFreeBay(1)) / 2;
00364       }
00365     } break;
00366 
00367     default:
00368       break;
00369   }
00370 
00371   /* Determine extra costs */
00372 
00373   /* Check for slope */
00374   cost += NPFSlopeCost(current);
00375 
00376   /* Check for turns. Road vehicles only really drive diagonal, turns are
00377    * represented by non-diagonal tracks */
00378   if (!IsDiagonalTrackdir(current->direction))
00379     cost += _settings_game.pf.npf.npf_road_curve_penalty;
00380 
00381   NPFMarkTile(tile);
00382   DEBUG(npf, 4, "Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);
00383   return cost;
00384 }
00385 
00386 
00387 /* Determine the cost of this node, for railway tracks */
00388 static int32 NPFRailPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
00389 {
00390   TileIndex tile = current->tile;
00391   Trackdir trackdir = current->direction;
00392   int32 cost = 0;
00393   /* HACK: We create a OpenListNode manually, so we can call EndNodeCheck */
00394   OpenListNode new_node;
00395 
00396   /* Determine base length */
00397   switch (GetTileType(tile)) {
00398     case MP_TUNNELBRIDGE:
00399       cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
00400       break;
00401 
00402     case MP_RAILWAY:
00403       cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
00404       break;
00405 
00406     case MP_ROAD: // Railway crossing
00407       cost = NPF_TILE_LENGTH;
00408       break;
00409 
00410     case MP_STATION:
00411       /* We give a station tile a penalty. Logically we would only want to give
00412        * station tiles that are not our destination this penalty. This would
00413        * discourage trains to drive through busy stations. But, we can just
00414        * give any station tile a penalty, because every possible route will get
00415        * this penalty exactly once, on its end tile (if it's a station) and it
00416        * will therefore not make a difference. */
00417       cost = NPF_TILE_LENGTH + _settings_game.pf.npf.npf_rail_station_penalty;
00418 
00419       if (IsRailWaypoint(tile)) {
00420         NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
00421         if (fstd->v->current_order.IsType(OT_GOTO_WAYPOINT) && GetStationIndex(tile) == fstd->v->current_order.GetDestination()) {
00422           /* This waypoint is our destination; maybe this isn't an unreserved
00423            * one, so check that and if so see that as the last signal being
00424            * red. This way waypoints near stations should work better. */
00425           const Train *train = Train::From(fstd->v);
00426           CFollowTrackRail ft(train);
00427           TileIndex t = tile;
00428           Trackdir td = trackdir;
00429           while (ft.Follow(t, td)) {
00430             assert(t != ft.m_new_tile);
00431             t = ft.m_new_tile;
00432             if (KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
00433               /* We encountered a junction; it's going to be too complex to
00434                * handle this perfectly, so just bail out. There is no simple
00435                * free path, so try the other possibilities. */
00436               td = INVALID_TRACKDIR;
00437               break;
00438             }
00439             td = RemoveFirstTrackdir(&ft.m_new_td_bits);
00440             /* If this is a safe waiting position we're done searching for it */
00441             if (IsSafeWaitingPosition(train, t, td, true, _settings_game.pf.forbid_90_deg)) break;
00442           }
00443           if (td == INVALID_TRACKDIR ||
00444               !IsSafeWaitingPosition(train, t, td, true, _settings_game.pf.forbid_90_deg) ||
00445               !IsWaitingPositionFree(train, t, td, _settings_game.pf.forbid_90_deg)) {
00446             cost += _settings_game.pf.npf.npf_rail_lastred_penalty;
00447           }
00448         }
00449       }
00450       break;
00451 
00452     default:
00453       break;
00454   }
00455 
00456   /* Determine extra costs */
00457 
00458   /* Check for signals */
00459   if (IsTileType(tile, MP_RAILWAY)) {
00460     if (HasSignalOnTrackdir(tile, trackdir)) {
00461       SignalType sigtype = GetSignalType(tile, TrackdirToTrack(trackdir));
00462       /* Ordinary track with signals */
00463       if (GetSignalStateByTrackdir(tile, trackdir) == SIGNAL_STATE_RED) {
00464         /* Signal facing us is red */
00465         if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
00466           /* Penalize the first signal we
00467            * encounter, if it is red */
00468 
00469           /* Is this a presignal exit or combo? */
00470           if (!IsPbsSignal(sigtype)) {
00471             if (sigtype == SIGTYPE_EXIT || sigtype == SIGTYPE_COMBO) {
00472               /* Penalise exit and combo signals differently (heavier) */
00473               cost += _settings_game.pf.npf.npf_rail_firstred_exit_penalty;
00474             } else {
00475               cost += _settings_game.pf.npf.npf_rail_firstred_penalty;
00476             }
00477           }
00478         }
00479         /* Record the state of this signal */
00480         NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, true);
00481       } else {
00482         /* Record the state of this signal */
00483         NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, false);
00484       }
00485       if (NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
00486         if (NPFGetFlag(current, NPF_FLAG_2ND_SIGNAL)) {
00487           NPFSetFlag(current, NPF_FLAG_3RD_SIGNAL, true);
00488         } else {
00489           NPFSetFlag(current, NPF_FLAG_2ND_SIGNAL, true);
00490         }
00491       } else {
00492         NPFSetFlag(current, NPF_FLAG_SEEN_SIGNAL, true);
00493       }
00494       NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_BLOCK, !IsPbsSignal(sigtype));
00495     }
00496 
00497     if (HasPbsSignalOnTrackdir(tile, ReverseTrackdir(trackdir)) && !NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL)) {
00498       cost += _settings_game.pf.npf.npf_rail_pbs_signal_back_penalty;
00499     }
00500   }
00501 
00502   /* Penalise the tile if it is a target tile and the last signal was
00503    * red */
00504   /* HACK: We create a new_node here so we can call EndNodeCheck. Ugly as hell
00505    * of course... */
00506   new_node.path.node = *current;
00507   if (as->EndNodeCheck(as, &new_node) == AYSTAR_FOUND_END_NODE && NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_RED))
00508     cost += _settings_game.pf.npf.npf_rail_lastred_penalty;
00509 
00510   /* Check for slope */
00511   cost += NPFSlopeCost(current);
00512 
00513   /* Check for turns */
00514   if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction))
00515     cost += _settings_game.pf.npf.npf_rail_curve_penalty;
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 occurence 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
00550     IsSafeWaitingPosition(v, current->path.node.tile, current->path.node.direction, true, _settings_game.pf.forbid_90_deg) &&
00551     IsWaitingPositionFree(v, current->path.node.tile, current->path.node.direction, _settings_game.pf.forbid_90_deg) ?
00552       AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
00553 }
00554 
00555 /* Will find a station identified using the NPFFindStationOrTileData */
00556 static int32 NPFFindStationOrTile(AyStar *as, OpenListNode *current)
00557 {
00558   NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
00559   AyStarNode *node = &current->path.node;
00560   TileIndex tile = node->tile;
00561 
00562   if (fstd->station_index == INVALID_STATION && tile == fstd->dest_coords) return AYSTAR_FOUND_END_NODE;
00563 
00564   if (IsTileType(tile, MP_STATION) && GetStationIndex(tile) == fstd->station_index) {
00565     if (fstd->v->type == VEH_TRAIN) return AYSTAR_FOUND_END_NODE;
00566 
00567     assert(fstd->v->type == VEH_ROAD);
00568     /* Only if it is a valid station *and* we can stop there */
00569     if (GetStationType(tile) == fstd->station_type && (fstd->not_articulated || IsDriveThroughStopTile(tile))) return AYSTAR_FOUND_END_NODE;
00570   }
00571   return AYSTAR_DONE;
00572 }
00573 
00581 static const PathNode *FindSafePosition(PathNode *path, const Train *v)
00582 {
00583   /* If there is no signal, reserve the whole path. */
00584   PathNode *sig = path;
00585 
00586   for (; path->parent != NULL; path = path->parent) {
00587     if (IsSafeWaitingPosition(v, path->node.tile, path->node.direction, true, _settings_game.pf.forbid_90_deg)) {
00588       sig = path;
00589     }
00590   }
00591 
00592   return sig;
00593 }
00594 
00598 static void ClearPathReservation(const PathNode *start, const PathNode *end)
00599 {
00600   bool first_run = true;
00601   for (; start != end; start = start->parent) {
00602     if (IsRailStationTile(start->node.tile) && first_run) {
00603       SetRailStationPlatformReservation(start->node.tile, TrackdirToExitdir(start->node.direction), false);
00604     } else {
00605       UnreserveRailTrack(start->node.tile, TrackdirToTrack(start->node.direction));
00606     }
00607     first_run = false;
00608   }
00609 }
00610 
00617 static void NPFSaveTargetData(AyStar *as, OpenListNode *current)
00618 {
00619   NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
00620   ftd->best_trackdir = (Trackdir)current->path.node.user_data[NPF_TRACKDIR_CHOICE];
00621   ftd->best_path_dist = current->g;
00622   ftd->best_bird_dist = 0;
00623   ftd->node = current->path.node;
00624   ftd->res_okay = false;
00625 
00626   if (as->user_target != NULL && ((NPFFindStationOrTileData*)as->user_target)->reserve_path && as->user_data[NPF_TYPE] == TRANSPORT_RAIL) {
00627     /* Path reservation is requested. */
00628     const Train *v = Train::From(((NPFFindStationOrTileData *)as->user_target)->v);
00629 
00630     const PathNode *target = FindSafePosition(&current->path, v);
00631     ftd->node = target->node;
00632 
00633     /* If the target is a station skip to platform end. */
00634     if (IsRailStationTile(target->node.tile)) {
00635       DiagDirection dir = TrackdirToExitdir(target->node.direction);
00636       uint len = Station::GetByTile(target->node.tile)->GetPlatformLength(target->node.tile, dir);
00637       TileIndex end_tile = TILE_ADD(target->node.tile, (len - 1) * TileOffsByDiagDir(dir));
00638 
00639       /* Update only end tile, trackdir of a station stays the same. */
00640       ftd->node.tile = end_tile;
00641       if (!IsWaitingPositionFree(v, end_tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
00642       SetRailStationPlatformReservation(target->node.tile, dir, true);
00643       SetRailStationReservation(target->node.tile, false);
00644     } else {
00645       if (!IsWaitingPositionFree(v, target->node.tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
00646     }
00647 
00648     for (const PathNode *cur = target; cur->parent != NULL; cur = cur->parent) {
00649       if (!TryReserveRailTrack(cur->node.tile, TrackdirToTrack(cur->node.direction))) {
00650         /* Reservation failed, undo. */
00651         ClearPathReservation(target, cur);
00652         return;
00653       }
00654     }
00655 
00656     ftd->res_okay = true;
00657   }
00658 }
00659 
00669 static bool CanEnterTileOwnerCheck(Owner owner, TileIndex tile, DiagDirection enterdir)
00670 {
00671   if (IsTileType(tile, MP_RAILWAY) || // Rail tile (also rail depot)
00672       HasStationTileRail(tile) ||     // Rail station tile/waypoint
00673       IsRoadDepotTile(tile) ||        // Road depot tile
00674       IsStandardRoadStopTile(tile)) { // Road station tile (but not drive-through stops)
00675     return IsTileOwner(tile, owner);  // You need to own these tiles entirely to use them
00676   }
00677 
00678   switch (GetTileType(tile)) {
00679     case MP_ROAD:
00680       /* rail-road crossing : are we looking at the railway part? */
00681       if (IsLevelCrossing(tile) &&
00682           DiagDirToAxis(enterdir) != GetCrossingRoadAxis(tile)) {
00683         return IsTileOwner(tile, owner); // Railway needs owner check, while the street is public
00684       }
00685       break;
00686 
00687     case MP_TUNNELBRIDGE:
00688       if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
00689         return IsTileOwner(tile, owner);
00690       }
00691       break;
00692 
00693     default:
00694       break;
00695   }
00696 
00697   return true; // no need to check
00698 }
00699 
00700 
00704 static DiagDirection GetDepotDirection(TileIndex tile, TransportType type)
00705 {
00706   assert(IsDepotTypeTile(tile, type));
00707 
00708   switch (type) {
00709     case TRANSPORT_RAIL:  return GetRailDepotDirection(tile);
00710     case TRANSPORT_ROAD:  return GetRoadDepotDirection(tile);
00711     case TRANSPORT_WATER: return GetShipDepotDirection(tile);
00712     default: return INVALID_DIAGDIR; // Not reached
00713   }
00714 }
00715 
00717 static DiagDirection GetSingleTramBit(TileIndex tile)
00718 {
00719   if (IsNormalRoadTile(tile)) {
00720     RoadBits rb = GetRoadBits(tile, ROADTYPE_TRAM);
00721     switch (rb) {
00722       case ROAD_NW: return DIAGDIR_NW;
00723       case ROAD_SW: return DIAGDIR_SW;
00724       case ROAD_SE: return DIAGDIR_SE;
00725       case ROAD_NE: return DIAGDIR_NE;
00726       default: break;
00727     }
00728   }
00729   return INVALID_DIAGDIR;
00730 }
00731 
00742 static DiagDirection GetTileSingleEntry(TileIndex tile, TransportType type, uint subtype)
00743 {
00744   if (type != TRANSPORT_WATER && IsDepotTypeTile(tile, type)) return GetDepotDirection(tile, type);
00745 
00746   if (type == TRANSPORT_ROAD) {
00747     if (IsStandardRoadStopTile(tile)) return GetRoadStopDir(tile);
00748     if (HasBit(subtype, ROADTYPE_TRAM)) return GetSingleTramBit(tile);
00749   }
00750 
00751   return INVALID_DIAGDIR;
00752 }
00753 
00763 static inline bool ForceReverse(TileIndex tile, DiagDirection dir, TransportType type, uint subtype)
00764 {
00765   DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
00766   return single_entry != INVALID_DIAGDIR && single_entry != dir;
00767 }
00768 
00780 static bool CanEnterTile(TileIndex tile, DiagDirection dir, TransportType type, uint subtype, RailTypes railtypes, Owner owner)
00781 {
00782   /* Check tunnel entries and bridge ramps */
00783   if (IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(tile) != dir) return false;
00784 
00785   /* Test ownership */
00786   if (!CanEnterTileOwnerCheck(owner, tile, dir)) return false;
00787 
00788   /* check correct rail type (mono, maglev, etc) */
00789   if (type == TRANSPORT_RAIL) {
00790     RailType rail_type = GetTileRailType(tile);
00791     if (!HasBit(railtypes, rail_type)) return false;
00792   }
00793 
00794   /* Depots, standard roadstops and single tram bits can only be entered from one direction */
00795   DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
00796   if (single_entry != INVALID_DIAGDIR && single_entry != ReverseDiagDir(dir)) return false;
00797 
00798   return true;
00799 }
00800 
00812 static TrackdirBits GetDriveableTrackdirBits(TileIndex dst_tile, Trackdir src_trackdir, TransportType type, uint subtype)
00813 {
00814   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(dst_tile, type, subtype));
00815 
00816   if (trackdirbits == 0 && type == TRANSPORT_ROAD && HasBit(subtype, ROADTYPE_TRAM)) {
00817     /* GetTileTrackStatus() returns 0 for single tram bits.
00818      * As we cannot change it there (easily) without breaking something, change it here */
00819     switch (GetSingleTramBit(dst_tile)) {
00820       case DIAGDIR_NE:
00821       case DIAGDIR_SW:
00822         trackdirbits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
00823         break;
00824 
00825       case DIAGDIR_NW:
00826       case DIAGDIR_SE:
00827         trackdirbits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
00828         break;
00829 
00830       default: break;
00831     }
00832   }
00833 
00834   DEBUG(npf, 4, "Next node: (%d, %d) [%d], possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), dst_tile, trackdirbits);
00835 
00836   /* Select only trackdirs we can reach from our current trackdir */
00837   trackdirbits &= TrackdirReachesTrackdirs(src_trackdir);
00838 
00839   /* Filter out trackdirs that would make 90 deg turns for trains */
00840   if (_settings_game.pf.forbid_90_deg && (type == TRANSPORT_RAIL || type == TRANSPORT_WATER)) trackdirbits &= ~TrackdirCrossesTrackdirs(src_trackdir);
00841 
00842   DEBUG(npf, 6, "After filtering: (%d, %d), possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), trackdirbits);
00843 
00844   return trackdirbits;
00845 }
00846 
00847 
00848 /* Will just follow the results of GetTileTrackStatus concerning where we can
00849  * go and where not. Uses AyStar.user_data[NPF_TYPE] as the transport type and
00850  * an argument to GetTileTrackStatus. Will skip tunnels, meaning that the
00851  * entry and exit are neighbours. Will fill
00852  * AyStarNode.user_data[NPF_TRACKDIR_CHOICE] with an appropriate value, and
00853  * copy AyStarNode.user_data[NPF_NODE_FLAGS] from the parent */
00854 static void NPFFollowTrack(AyStar *aystar, OpenListNode *current)
00855 {
00856   /* We leave src_tile on track src_trackdir in direction src_exitdir */
00857   Trackdir src_trackdir = current->path.node.direction;
00858   TileIndex src_tile = current->path.node.tile;
00859   DiagDirection src_exitdir = TrackdirToExitdir(src_trackdir);
00860 
00861   /* Is src_tile valid, and can be used?
00862    * When choosing track on a junction src_tile is the tile neighboured to the junction wrt. exitdir.
00863    * 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. */
00864   bool ignore_src_tile = (current->path.parent == NULL && NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_START_TILE));
00865 
00866   /* Information about the vehicle: TransportType (road/rail/water) and SubType (compatible rail/road types) */
00867   TransportType type = (TransportType)aystar->user_data[NPF_TYPE];
00868   uint subtype = aystar->user_data[NPF_SUB_TYPE];
00869 
00870   /* Initialize to 0, so we can jump out (return) somewhere an have no neighbours */
00871   aystar->num_neighbours = 0;
00872   DEBUG(npf, 4, "Expanding: (%d, %d, %d) [%d]", TileX(src_tile), TileY(src_tile), src_trackdir, src_tile);
00873 
00874   /* We want to determine the tile we arrive, and which choices we have there */
00875   TileIndex dst_tile;
00876   TrackdirBits trackdirbits;
00877 
00878   /* Find dest tile */
00879   if (ignore_src_tile) {
00880     /* Do not perform any checks that involve src_tile */
00881     dst_tile = src_tile + TileOffsByDiagDir(src_exitdir);
00882     trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
00883   } else if (IsTileType(src_tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(src_tile) == src_exitdir) {
00884     /* We drive through the wormhole and arrive on the other side */
00885     dst_tile = GetOtherTunnelBridgeEnd(src_tile);
00886     trackdirbits = TrackdirToTrackdirBits(src_trackdir);
00887   } else if (ForceReverse(src_tile, src_exitdir, type, subtype)) {
00888     /* We can only reverse on this tile */
00889     dst_tile = src_tile;
00890     src_trackdir = ReverseTrackdir(src_trackdir);
00891     trackdirbits = TrackdirToTrackdirBits(src_trackdir);
00892   } else {
00893     /* We leave src_tile in src_exitdir and reach dst_tile */
00894     dst_tile = AddTileIndexDiffCWrap(src_tile, TileIndexDiffCByDiagDir(src_exitdir));
00895 
00896     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;
00897 
00898     if (dst_tile == INVALID_TILE) {
00899       /* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
00900       if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
00901 
00902       dst_tile = src_tile;
00903       src_trackdir = ReverseTrackdir(src_trackdir);
00904     }
00905 
00906     trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
00907 
00908     if (trackdirbits == 0) {
00909       /* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
00910       if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
00911 
00912       dst_tile = src_tile;
00913       src_trackdir = ReverseTrackdir(src_trackdir);
00914 
00915       trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
00916     }
00917   }
00918 
00919   if (NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_RESERVED)) {
00920     /* Mask out any reserved tracks. */
00921     TrackBits reserved = GetReservedTrackbits(dst_tile);
00922     trackdirbits &= ~TrackBitsToTrackdirBits(reserved);
00923 
00924     uint bits = TrackdirBitsToTrackBits(trackdirbits);
00925     int i;
00926     FOR_EACH_SET_BIT(i, bits) {
00927       if (TracksOverlap(reserved | TrackToTrackBits((Track)i))) trackdirbits &= ~TrackToTrackdirBits((Track)i);
00928     }
00929   }
00930 
00931   /* Enumerate possible track */
00932   uint i = 0;
00933   while (trackdirbits != 0) {
00934     Trackdir dst_trackdir = RemoveFirstTrackdir(&trackdirbits);
00935     DEBUG(npf, 5, "Expanded into trackdir: %d, remaining trackdirs: 0x%X", dst_trackdir, trackdirbits);
00936 
00937     /* Tile with signals? */
00938     if (IsTileType(dst_tile, MP_RAILWAY) && GetRailTileType(dst_tile) == RAIL_TILE_SIGNALS) {
00939       if (HasSignalOnTrackdir(dst_tile, ReverseTrackdir(dst_trackdir)) && !HasSignalOnTrackdir(dst_tile, dst_trackdir) && IsOnewaySignal(dst_tile, TrackdirToTrack(dst_trackdir)))
00940         /* If there's a one-way signal not pointing towards us, stop going in this direction. */
00941         break;
00942     }
00943     {
00944       /* We've found ourselves a neighbour :-) */
00945       AyStarNode *neighbour = &aystar->neighbours[i];
00946       neighbour->tile = dst_tile;
00947       neighbour->direction = dst_trackdir;
00948       /* Save user data */
00949       neighbour->user_data[NPF_NODE_FLAGS] = current->path.node.user_data[NPF_NODE_FLAGS];
00950       NPFFillTrackdirChoice(neighbour, current);
00951     }
00952     i++;
00953   }
00954   aystar->num_neighbours = i;
00955 }
00956 
00957 /*
00958  * Plan a route to the specified target (which is checked by target_proc),
00959  * from start1 and if not NULL, from start2 as well. The type of transport we
00960  * are checking is in type. reverse_penalty is applied to all routes that
00961  * originate from the second start node.
00962  * When we are looking for one specific target (optionally multiple tiles), we
00963  * should use a good heuristic to perform aystar search. When we search for
00964  * multiple targets that are spread around, we should perform a breadth first
00965  * search by specifiying CalcZero as our heuristic.
00966  */
00967 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)
00968 {
00969   int r;
00970   NPFFoundTargetData result;
00971 
00972   /* Initialize procs */
00973   _npf_aystar.CalculateH = heuristic_proc;
00974   _npf_aystar.EndNodeCheck = target_proc;
00975   _npf_aystar.FoundEndNode = NPFSaveTargetData;
00976   _npf_aystar.GetNeighbours = NPFFollowTrack;
00977   switch (type) {
00978     default: NOT_REACHED();
00979     case TRANSPORT_RAIL:  _npf_aystar.CalculateG = NPFRailPathCost;  break;
00980     case TRANSPORT_ROAD:  _npf_aystar.CalculateG = NPFRoadPathCost;  break;
00981     case TRANSPORT_WATER: _npf_aystar.CalculateG = NPFWaterPathCost; break;
00982   }
00983 
00984   /* Initialize Start Node(s) */
00985   start1->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
00986   start1->user_data[NPF_NODE_FLAGS] = 0;
00987   NPFSetFlag(start1, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile1);
00988   _npf_aystar.addstart(&_npf_aystar, start1, 0);
00989   if (start2) {
00990     start2->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
00991     start2->user_data[NPF_NODE_FLAGS] = 0;
00992     NPFSetFlag(start2, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile2);
00993     NPFSetFlag(start2, NPF_FLAG_REVERSE, true);
00994     _npf_aystar.addstart(&_npf_aystar, start2, reverse_penalty);
00995   }
00996 
00997   /* Initialize result */
00998   result.best_bird_dist = UINT_MAX;
00999   result.best_path_dist = UINT_MAX;
01000   result.best_trackdir  = INVALID_TRACKDIR;
01001   result.node.tile      = INVALID_TILE;
01002   result.res_okay       = false;
01003   _npf_aystar.user_path = &result;
01004 
01005   /* Initialize target */
01006   _npf_aystar.user_target = target;
01007 
01008   /* Initialize user_data */
01009   _npf_aystar.user_data[NPF_TYPE] = type;
01010   _npf_aystar.user_data[NPF_SUB_TYPE] = sub_type;
01011   _npf_aystar.user_data[NPF_OWNER] = owner;
01012   _npf_aystar.user_data[NPF_RAILTYPES] = railtypes;
01013 
01014   /* GO! */
01015   r = AyStarMain_Main(&_npf_aystar);
01016   assert(r != AYSTAR_STILL_BUSY);
01017 
01018   if (result.best_bird_dist != 0) {
01019     if (target != NULL) {
01020       DEBUG(npf, 1, "Could not find route to tile 0x%X from 0x%X.", target->dest_coords, start1->tile);
01021     } else {
01022       /* Assumption: target == NULL, so we are looking for a depot */
01023       DEBUG(npf, 1, "Could not find route to a depot from tile 0x%X.", start1->tile);
01024     }
01025 
01026   }
01027   return result;
01028 }
01029 
01030 /* Will search as below, but with two start nodes, the second being the
01031  * reverse. Look at the NPF_FLAG_REVERSE flag in the result node to see which
01032  * direction was taken (NPFGetFlag(result.node, NPF_FLAG_REVERSE)) */
01033 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)
01034 {
01035   AyStarNode start1;
01036   AyStarNode start2;
01037 
01038   start1.tile = tile1;
01039   start2.tile = tile2;
01040   /* We set this in case the target is also the start tile, we will just
01041    * return a not found then */
01042   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01043   start1.direction = trackdir1;
01044   start2.direction = trackdir2;
01045   start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01046 
01047   return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, target, NPFFindStationOrTile, NPFCalcStationOrTileHeuristic, type, sub_type, owner, railtypes, 0);
01048 }
01049 
01050 /* Will search from the given tile and direction, for a route to the given
01051  * station for the given transport type. See the declaration of
01052  * NPFFoundTargetData above for the meaning of the result. */
01053 static NPFFoundTargetData NPFRouteToStationOrTile(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes)
01054 {
01055   return NPFRouteToStationOrTileTwoWay(tile, trackdir, ignore_start_tile, INVALID_TILE, INVALID_TRACKDIR, false, target, type, sub_type, owner, railtypes);
01056 }
01057 
01058 /* Search using breadth first. Good for little track choice and inaccurate
01059  * heuristic, such as railway/road with two start nodes, the second being the reverse. Call
01060  * NPFGetFlag(result.node, NPF_FLAG_REVERSE) to see from which node the path
01061  * orginated. All pathfs from the second node will have the given
01062  * reverse_penalty applied (NPF_TILE_LENGTH is the equivalent of one full
01063  * tile).
01064  */
01065 static NPFFoundTargetData NPFRouteToDepotBreadthFirstTwoWay(TileIndex tile1, Trackdir trackdir1, bool ignore_start_tile1, TileIndex tile2, Trackdir trackdir2, bool ignore_start_tile2, TransportType type, uint sub_type, Owner owner, RailTypes railtypes, uint reverse_penalty)
01066 {
01067   AyStarNode start1;
01068   AyStarNode start2;
01069 
01070   start1.tile = tile1;
01071   start2.tile = tile2;
01072   /* We set this in case the target is also the start tile, we will just
01073    * return a not found then */
01074   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01075   start1.direction = trackdir1;
01076   start2.direction = trackdir2;
01077   start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01078 
01079   /* perform a breadth first search. Target is NULL,
01080    * since we are just looking for any depot...*/
01081   return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, NULL, NPFFindDepot, NPFCalcZero, type, sub_type, owner, railtypes, reverse_penalty);
01082 }
01083 
01084 void InitializeNPF()
01085 {
01086   static bool first_init = true;
01087   if (first_init) {
01088     first_init = false;
01089     init_AyStar(&_npf_aystar, NPFHash, NPF_HASH_SIZE);
01090   } else {
01091     AyStarMain_Clear(&_npf_aystar);
01092   }
01093   _npf_aystar.loops_per_tick = 0;
01094   _npf_aystar.max_path_cost = 0;
01095   //_npf_aystar.max_search_nodes = 0;
01096   /* We will limit the number of nodes for now, until we have a better
01097    * solution to really fix performance */
01098   _npf_aystar.max_search_nodes = _settings_game.pf.npf.npf_max_search_nodes;
01099 }
01100 
01101 static void NPFFillWithOrderData(NPFFindStationOrTileData *fstd, const Vehicle *v, bool reserve_path = false)
01102 {
01103   /* Ships don't really reach their stations, but the tile in front. So don't
01104    * save the station id for ships. For roadvehs we don't store it either,
01105    * because multistop depends on vehicles actually reaching the exact
01106    * dest_tile, not just any stop of that station.
01107    * So only for train orders to stations we fill fstd->station_index, for all
01108    * others only dest_coords */
01109   if (v->type != VEH_SHIP && (v->current_order.IsType(OT_GOTO_STATION) || v->current_order.IsType(OT_GOTO_WAYPOINT))) {
01110     assert(v->type == VEH_TRAIN || v->type == VEH_ROAD);
01111     fstd->station_index = v->current_order.GetDestination();
01112     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);
01113     fstd->not_articulated = v->type == VEH_ROAD && !RoadVehicle::From(v)->HasArticulatedPart();
01114     /* Let's take the closest tile of the station as our target for vehicles */
01115     fstd->dest_coords = CalcClosestStationTile(fstd->station_index, v->tile, fstd->station_type);
01116   } else {
01117     fstd->dest_coords = v->dest_tile;
01118     fstd->station_index = INVALID_STATION;
01119   }
01120   fstd->reserve_path = reserve_path;
01121   fstd->v = v;
01122 }
01123 
01124 /*** Road vehicles ***/
01125 
01126 FindDepotData NPFRoadVehicleFindNearestDepot(const RoadVehicle *v, int max_penalty)
01127 {
01128   Trackdir trackdir = v->GetVehicleTrackdir();
01129 
01130   NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, v->tile, ReverseTrackdir(trackdir), false, TRANSPORT_ROAD, v->compatible_roadtypes, v->owner, INVALID_RAILTYPES, 0);
01131 
01132   if (ftd.best_bird_dist != 0) return FindDepotData();
01133 
01134   /* Found target */
01135   /* Our caller expects a number of tiles, so we just approximate that
01136    * number by this. It might not be completely what we want, but it will
01137    * work for now :-) We can possibly change this when the old pathfinder
01138    * is removed. */
01139   return FindDepotData(ftd.node.tile, ftd.best_path_dist);
01140 }
01141 
01142 Trackdir NPFRoadVehicleChooseTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs)
01143 {
01144   NPFFindStationOrTileData fstd;
01145 
01146   NPFFillWithOrderData(&fstd, v);
01147   Trackdir trackdir = DiagDirToDiagTrackdir(enterdir);
01148 
01149   NPFFoundTargetData ftd = NPFRouteToStationOrTile(tile - TileOffsByDiagDir(enterdir), trackdir, true, &fstd, TRANSPORT_ROAD, v->compatible_roadtypes, v->owner, INVALID_RAILTYPES);
01150   if (ftd.best_trackdir == INVALID_TRACKDIR) {
01151     /* We are already at our target. Just do something
01152      * @todo: maybe display error?
01153      * @todo: go straight ahead if possible? */
01154     return (Trackdir)FindFirstBit2x64(trackdirs);
01155   }
01156 
01157   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
01158    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
01159    * we did not find our target, but ftd.best_trackdir contains the direction leading
01160    * to the tile closest to our target. */
01161   return ftd.best_trackdir;
01162 }
01163 
01164 /*** Ships ***/
01165 
01166 Track NPFShipChooseTrack(const Ship *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks)
01167 {
01168   NPFFindStationOrTileData fstd;
01169   Trackdir trackdir = v->GetVehicleTrackdir();
01170   assert(trackdir != INVALID_TRACKDIR); // Check that we are not in a depot
01171 
01172   NPFFillWithOrderData(&fstd, v);
01173 
01174   NPFFoundTargetData ftd = NPFRouteToStationOrTile(tile - TileOffsByDiagDir(enterdir), trackdir, true, &fstd, TRANSPORT_WATER, 0, v->owner, INVALID_RAILTYPES);
01175 
01176   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
01177    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
01178    * we did not find our target, but ftd.best_trackdir contains the direction leading
01179    * to the tile closest to our target. */
01180   if (ftd.best_trackdir == 0xff) return INVALID_TRACK;
01181   return TrackdirToTrack(ftd.best_trackdir);
01182 }
01183 
01184 /*** Trains ***/
01185 
01186 FindDepotData NPFTrainFindNearestDepot(const Train *v, int max_penalty)
01187 {
01188   const Train *last = v->Last();
01189   Trackdir trackdir = v->GetVehicleTrackdir();
01190   Trackdir trackdir_rev = ReverseTrackdir(last->GetVehicleTrackdir());
01191 
01192   assert(trackdir != INVALID_TRACKDIR);
01193   NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, TRANSPORT_RAIL, 0, v->owner, v->compatible_railtypes, NPF_INFINITE_PENALTY);
01194   if (ftd.best_bird_dist != 0) return FindDepotData();
01195 
01196   /* Found target */
01197   /* Our caller expects a number of tiles, so we just approximate that
01198    * number by this. It might not be completely what we want, but it will
01199    * work for now :-) We can possibly change this when the old pathfinder
01200    * is removed. */
01201   return FindDepotData(ftd.node.tile, ftd.best_path_dist, NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE));
01202 }
01203 
01204 bool NPFTrainFindNearestSafeTile(const Train *v, TileIndex tile, Trackdir trackdir, bool override_railtype)
01205 {
01206   assert(v->type == VEH_TRAIN);
01207 
01208   NPFFindStationOrTileData fstd;
01209   fstd.v = v;
01210   fstd.reserve_path = true;
01211 
01212   AyStarNode start1;
01213   start1.tile = tile;
01214   /* We set this in case the target is also the start tile, we will just
01215    * return a not found then */
01216   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01217   start1.direction = trackdir;
01218   NPFSetFlag(&start1, NPF_FLAG_IGNORE_RESERVED, true);
01219 
01220   RailTypes railtypes = v->compatible_railtypes;
01221   if (override_railtype) railtypes |= GetRailTypeInfo(v->railtype)->compatible_railtypes;
01222 
01223   /* perform a breadth first search. Target is NULL,
01224    * since we are just looking for any safe tile...*/
01225   return NPFRouteInternal(&start1, true, NULL, false, &fstd, NPFFindSafeTile, NPFCalcZero, TRANSPORT_RAIL, 0, v->owner, railtypes, 0).res_okay;
01226 }
01227 
01228 bool NPFTrainCheckReverse(const Train *v)
01229 {
01230   NPFFindStationOrTileData fstd;
01231   NPFFoundTargetData ftd;
01232   const Train *last = v->Last();
01233 
01234   NPFFillWithOrderData(&fstd, v);
01235 
01236   Trackdir trackdir = v->GetVehicleTrackdir();
01237   Trackdir trackdir_rev = ReverseTrackdir(last->GetVehicleTrackdir());
01238   assert(trackdir != INVALID_TRACKDIR);
01239   assert(trackdir_rev != INVALID_TRACKDIR);
01240 
01241   ftd = NPFRouteToStationOrTileTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, &fstd, TRANSPORT_RAIL, 0, v->owner, v->compatible_railtypes);
01242   /* If we didn't find anything, just keep on going straight ahead, otherwise take the reverse flag */
01243   return ftd.best_bird_dist != 0 && NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE);
01244 }
01245 
01246 Track NPFTrainChooseTrack(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, struct PBSTileInfo *target)
01247 {
01248   NPFFindStationOrTileData fstd;
01249   NPFFillWithOrderData(&fstd, v, reserve_track);
01250 
01251   PBSTileInfo origin = FollowTrainReservation(v);
01252   assert(IsValidTrackdir(origin.trackdir));
01253 
01254   NPFFoundTargetData ftd = NPFRouteToStationOrTile(origin.tile, origin.trackdir, true, &fstd, TRANSPORT_RAIL, 0, v->owner, v->compatible_railtypes);
01255 
01256   if (target != NULL) {
01257     target->tile = ftd.node.tile;
01258     target->trackdir = (Trackdir)ftd.node.direction;
01259     target->okay = ftd.res_okay;
01260   }
01261 
01262   if (ftd.best_trackdir == INVALID_TRACKDIR) {
01263     /* We are already at our target. Just do something
01264      * @todo maybe display error?
01265      * @todo: go straight ahead if possible? */
01266     if (path_not_found) *path_not_found = false;
01267     return FindFirstTrack(tracks);
01268   }
01269 
01270   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
01271    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
01272    * we did not find our target, but ftd.best_trackdir contains the direction leading
01273    * to the tile closest to our target. */
01274   if (path_not_found != NULL) *path_not_found = (ftd.best_bird_dist != 0);
01275   /* Discard enterdir information, making it a normal track */
01276   return TrackdirToTrack(ftd.best_trackdir);
01277 }

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