npf.cpp

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00001 /* $Id: npf.cpp 24600 2012-10-17 18:43:23Z 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 "../../network/network.h"
00014 #include "../../viewport_func.h"
00015 #include "../../ship.h"
00016 #include "../../roadstop_base.h"
00017 #include "../pathfinder_func.h"
00018 #include "../pathfinder_type.h"
00019 #include "../follow_track.hpp"
00020 #include "aystar.h"
00021 
00022 static const uint NPF_HASH_BITS = 12; 
00023 /* Do no change below values */
00024 static const uint NPF_HASH_SIZE = 1 << NPF_HASH_BITS;
00025 static const uint NPF_HASH_HALFBITS = NPF_HASH_BITS / 2;
00026 static const uint NPF_HASH_HALFMASK = (1 << NPF_HASH_HALFBITS) - 1;
00027 
00029 struct NPFFindStationOrTileData {
00030   TileIndex dest_coords;    
00031   StationID station_index;  
00032   bool reserve_path;        
00033   StationType station_type; 
00034   bool not_articulated;     
00035   const Vehicle *v;         
00036 };
00037 
00039 enum AyStarUserDataType {
00040   NPF_TYPE = 0,  
00041   NPF_SUB_TYPE,  
00042   NPF_OWNER,     
00043   NPF_RAILTYPES, 
00044 };
00045 
00047 enum AyStarNodeUserDataType {
00048   NPF_TRACKDIR_CHOICE = 0, 
00049   NPF_NODE_FLAGS,
00050 };
00051 
00053 enum NPFNodeFlag {
00054   NPF_FLAG_SEEN_SIGNAL,       
00055   NPF_FLAG_2ND_SIGNAL,        
00056   NPF_FLAG_3RD_SIGNAL,        
00057   NPF_FLAG_REVERSE,           
00058   NPF_FLAG_LAST_SIGNAL_RED,   
00059   NPF_FLAG_LAST_SIGNAL_BLOCK, 
00060   NPF_FLAG_IGNORE_START_TILE, 
00061   NPF_FLAG_TARGET_RESERVED,   
00062   NPF_FLAG_IGNORE_RESERVED,   
00063 };
00064 
00066 struct NPFFoundTargetData {
00067   uint best_bird_dist;    
00068   uint best_path_dist;    
00069   Trackdir best_trackdir; 
00070   AyStarNode node;        
00071   bool res_okay;          
00072 };
00073 
00074 static AyStar _npf_aystar;
00075 
00076 /* The cost of each trackdir. A diagonal piece is the full NPF_TILE_LENGTH,
00077  * the shorter piece is sqrt(2)/2*NPF_TILE_LENGTH =~ 0.7071
00078  */
00079 #define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)
00080 static const uint _trackdir_length[TRACKDIR_END] = {
00081   NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH,
00082   0, 0,
00083   NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH
00084 };
00085 
00089 static inline bool NPFGetFlag(const AyStarNode *node, NPFNodeFlag flag)
00090 {
00091   return HasBit(node->user_data[NPF_NODE_FLAGS], flag);
00092 }
00093 
00097 static inline void NPFSetFlag(AyStarNode *node, NPFNodeFlag flag, bool value)
00098 {
00099   SB(node->user_data[NPF_NODE_FLAGS], flag, 1, value);
00100 }
00101 
00108 static uint NPFDistanceTrack(TileIndex t0, TileIndex t1)
00109 {
00110   const uint dx = Delta(TileX(t0), TileX(t1));
00111   const uint dy = Delta(TileY(t0), TileY(t1));
00112 
00113   const uint straightTracks = 2 * min(dx, dy); // The number of straight (not full length) tracks
00114   /* OPTIMISATION:
00115    * Original: diagTracks = max(dx, dy) - min(dx,dy);
00116    * Proof:
00117    * (dx+dy) - straightTracks  == (min + max) - straightTracks = min + max - 2 * min = max - min */
00118   const uint diagTracks = dx + dy - straightTracks; // The number of diagonal (full tile length) tracks.
00119 
00120   /* Don't factor out NPF_TILE_LENGTH below, this will round values and lose
00121    * precision */
00122   return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;
00123 }
00124 
00132 static uint NPFHash(uint key1, uint key2)
00133 {
00134   /* TODO: think of a better hash? */
00135   uint part1 = TileX(key1) & NPF_HASH_HALFMASK;
00136   uint part2 = TileY(key1) & NPF_HASH_HALFMASK;
00137 
00138   assert(IsValidTrackdir((Trackdir)key2));
00139   assert(IsValidTile(key1));
00140   return ((part1 << NPF_HASH_HALFBITS | part2) + (NPF_HASH_SIZE * key2 / TRACKDIR_END)) % NPF_HASH_SIZE;
00141 }
00142 
00143 static int32 NPFCalcZero(AyStar *as, AyStarNode *current, OpenListNode *parent)
00144 {
00145   return 0;
00146 }
00147 
00148 /* Calcs the heuristic to the target station or tile. For train stations, it
00149  * takes into account the direction of approach.
00150  */
00151 static int32 NPFCalcStationOrTileHeuristic(AyStar *as, AyStarNode *current, OpenListNode *parent)
00152 {
00153   NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
00154   NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
00155   TileIndex from = current->tile;
00156   TileIndex to = fstd->dest_coords;
00157   uint dist;
00158 
00159   /* for train-stations, we are going to aim for the closest station tile */
00160   if (as->user_data[NPF_TYPE] != TRANSPORT_WATER && fstd->station_index != INVALID_STATION) {
00161     to = CalcClosestStationTile(fstd->station_index, from, fstd->station_type);
00162   }
00163 
00164   if (as->user_data[NPF_TYPE] == TRANSPORT_ROAD) {
00165     /* Since roads only have diagonal pieces, we use manhattan distance here */
00166     dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;
00167   } else {
00168     /* Ships and trains can also go diagonal, so the minimum distance is shorter */
00169     dist = NPFDistanceTrack(from, to);
00170   }
00171 
00172   DEBUG(npf, 4, "Calculating H for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), dist);
00173 
00174   if (dist < ftd->best_bird_dist) {
00175     ftd->best_bird_dist = dist;
00176     ftd->best_trackdir = (Trackdir)current->user_data[NPF_TRACKDIR_CHOICE];
00177   }
00178   return dist;
00179 }
00180 
00181 
00182 /* Fills AyStarNode.user_data[NPF_TRACKDIRCHOICE] with the chosen direction to
00183  * get here, either getting it from the current choice or from the parent's
00184  * choice */
00185 static void NPFFillTrackdirChoice(AyStarNode *current, OpenListNode *parent)
00186 {
00187   if (parent->path.parent == NULL) {
00188     Trackdir trackdir = current->direction;
00189     /* This is a first order decision, so we'd better save the
00190      * direction we chose */
00191     current->user_data[NPF_TRACKDIR_CHOICE] = trackdir;
00192     DEBUG(npf, 6, "Saving trackdir: 0x%X", trackdir);
00193   } else {
00194     /* We've already made the decision, so just save our parent's decision */
00195     current->user_data[NPF_TRACKDIR_CHOICE] = parent->path.node.user_data[NPF_TRACKDIR_CHOICE];
00196   }
00197 }
00198 
00199 /* Will return the cost of the tunnel. If it is an entry, it will return the
00200  * cost of that tile. If the tile is an exit, it will return the tunnel length
00201  * including the exit tile. Requires that this is a Tunnel tile */
00202 static uint NPFTunnelCost(AyStarNode *current)
00203 {
00204   DiagDirection exitdir = TrackdirToExitdir(current->direction);
00205   TileIndex tile = current->tile;
00206   if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
00207     /* We just popped out if this tunnel, since were
00208      * facing the tunnel exit */
00209     return NPF_TILE_LENGTH * (GetTunnelBridgeLength(current->tile, GetOtherTunnelEnd(current->tile)) + 1);
00210     /* @todo: Penalty for tunnels? */
00211   } else {
00212     /* We are entering the tunnel, the enter tile is just a
00213      * straight track */
00214     return NPF_TILE_LENGTH;
00215   }
00216 }
00217 
00218 static inline uint NPFBridgeCost(AyStarNode *current)
00219 {
00220   return NPF_TILE_LENGTH * GetTunnelBridgeLength(current->tile, GetOtherBridgeEnd(current->tile));
00221 }
00222 
00223 static uint NPFSlopeCost(AyStarNode *current)
00224 {
00225   TileIndex next = current->tile + TileOffsByDiagDir(TrackdirToExitdir(current->direction));
00226 
00227   /* Get center of tiles */
00228   int x1 = TileX(current->tile) * TILE_SIZE + TILE_SIZE / 2;
00229   int y1 = TileY(current->tile) * TILE_SIZE + TILE_SIZE / 2;
00230   int x2 = TileX(next) * TILE_SIZE + TILE_SIZE / 2;
00231   int y2 = TileY(next) * TILE_SIZE + TILE_SIZE / 2;
00232 
00233   int dx4 = (x2 - x1) / 4;
00234   int dy4 = (y2 - y1) / 4;
00235 
00236   /* Get the height on both sides of the tile edge.
00237    * Avoid testing the height on the tile-center. This will fail for halftile-foundations.
00238    */
00239   int z1 = GetSlopePixelZ(x1 + dx4, y1 + dy4);
00240   int z2 = GetSlopePixelZ(x2 - dx4, y2 - dy4);
00241 
00242   if (z2 - z1 > 1) {
00243     /* Slope up */
00244     return _settings_game.pf.npf.npf_rail_slope_penalty;
00245   }
00246   return 0;
00247   /* Should we give a bonus for slope down? Probably not, we
00248    * could just substract that bonus from the penalty, because
00249    * there is only one level of steepness... */
00250 }
00251 
00252 static uint NPFReservedTrackCost(AyStarNode *current)
00253 {
00254   TileIndex tile = current->tile;
00255   TrackBits track = TrackToTrackBits(TrackdirToTrack(current->direction));
00256   TrackBits res = GetReservedTrackbits(tile);
00257 
00258   if (NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL) || NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_BLOCK) || ((res & track) == TRACK_BIT_NONE && !TracksOverlap(res | track))) return 0;
00259 
00260   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
00261     DiagDirection exitdir = TrackdirToExitdir(current->direction);
00262     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
00263       return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty * (GetTunnelBridgeLength(tile, GetOtherTunnelBridgeEnd(tile)) + 1);
00264     }
00265   }
00266   return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty;
00267 }
00268 
00273 static void NPFMarkTile(TileIndex tile)
00274 {
00275 #ifndef NO_DEBUG_MESSAGES
00276   if (_debug_npf_level < 1 || _networking) return;
00277   switch (GetTileType(tile)) {
00278     case MP_RAILWAY:
00279       /* DEBUG: mark visited tiles by mowing the grass under them ;-) */
00280       if (!IsRailDepot(tile)) {
00281         SetRailGroundType(tile, RAIL_GROUND_BARREN);
00282         MarkTileDirtyByTile(tile);
00283       }
00284       break;
00285 
00286     case MP_ROAD:
00287       if (!IsRoadDepot(tile)) {
00288         SetRoadside(tile, ROADSIDE_BARREN);
00289         MarkTileDirtyByTile(tile);
00290       }
00291       break;
00292 
00293     default:
00294       break;
00295   }
00296 #endif
00297 }
00298 
00299 static int32 NPFWaterPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
00300 {
00301   /* TileIndex tile = current->tile; */
00302   int32 cost = 0;
00303   Trackdir trackdir = current->direction;
00304 
00305   cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
00306 
00307   if (IsBuoyTile(current->tile) && IsDiagonalTrackdir(trackdir)) {
00308     cost += _settings_game.pf.npf.npf_buoy_penalty; // A small penalty for going over buoys
00309   }
00310 
00311   if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction)) {
00312     cost += _settings_game.pf.npf.npf_water_curve_penalty;
00313   }
00314 
00315   /* @todo More penalties? */
00316 
00317   return cost;
00318 }
00319 
00320 /* Determine the cost of this node, for road tracks */
00321 static int32 NPFRoadPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
00322 {
00323   TileIndex tile = current->tile;
00324   int32 cost = 0;
00325 
00326   /* Determine base length */
00327   switch (GetTileType(tile)) {
00328     case MP_TUNNELBRIDGE:
00329       cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
00330       break;
00331 
00332     case MP_ROAD:
00333       cost = NPF_TILE_LENGTH;
00334       /* Increase the cost for level crossings */
00335       if (IsLevelCrossing(tile)) cost += _settings_game.pf.npf.npf_crossing_penalty;
00336       break;
00337 
00338     case MP_STATION: {
00339       cost = NPF_TILE_LENGTH;
00340       const RoadStop *rs = RoadStop::GetByTile(tile, GetRoadStopType(tile));
00341       if (IsDriveThroughStopTile(tile)) {
00342         /* Increase the cost for drive-through road stops */
00343         cost += _settings_game.pf.npf.npf_road_drive_through_penalty;
00344         DiagDirection dir = TrackdirToExitdir(current->direction);
00345         if (!RoadStop::IsDriveThroughRoadStopContinuation(tile, tile - TileOffsByDiagDir(dir))) {
00346           /* When we're the first road stop in a 'queue' of them we increase
00347            * cost based on the fill percentage of the whole queue. */
00348           const RoadStop::Entry *entry = rs->GetEntry(dir);
00349           cost += entry->GetOccupied() * _settings_game.pf.npf.npf_road_dt_occupied_penalty / entry->GetLength();
00350         }
00351       } else {
00352         /* Increase cost for filled road stops */
00353         cost += _settings_game.pf.npf.npf_road_bay_occupied_penalty * (!rs->IsFreeBay(0) + !rs->IsFreeBay(1)) / 2;
00354       }
00355       break;
00356     }
00357 
00358     default:
00359       break;
00360   }
00361 
00362   /* Determine extra costs */
00363 
00364   /* Check for slope */
00365   cost += NPFSlopeCost(current);
00366 
00367   /* Check for turns. Road vehicles only really drive diagonal, turns are
00368    * represented by non-diagonal tracks */
00369   if (!IsDiagonalTrackdir(current->direction)) {
00370     cost += _settings_game.pf.npf.npf_road_curve_penalty;
00371   }
00372 
00373   NPFMarkTile(tile);
00374   DEBUG(npf, 4, "Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);
00375   return cost;
00376 }
00377 
00378 
00379 /* Determine the cost of this node, for railway tracks */
00380 static int32 NPFRailPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
00381 {
00382   TileIndex tile = current->tile;
00383   Trackdir trackdir = current->direction;
00384   int32 cost = 0;
00385   /* HACK: We create a OpenListNode manually, so we can call EndNodeCheck */
00386   OpenListNode new_node;
00387 
00388   /* Determine base length */
00389   switch (GetTileType(tile)) {
00390     case MP_TUNNELBRIDGE:
00391       cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
00392       break;
00393 
00394     case MP_RAILWAY:
00395       cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
00396       break;
00397 
00398     case MP_ROAD: // Railway crossing
00399       cost = NPF_TILE_LENGTH;
00400       break;
00401 
00402     case MP_STATION:
00403       /* We give a station tile a penalty. Logically we would only want to give
00404        * station tiles that are not our destination this penalty. This would
00405        * discourage trains to drive through busy stations. But, we can just
00406        * give any station tile a penalty, because every possible route will get
00407        * this penalty exactly once, on its end tile (if it's a station) and it
00408        * will therefore not make a difference. */
00409       cost = NPF_TILE_LENGTH + _settings_game.pf.npf.npf_rail_station_penalty;
00410 
00411       if (IsRailWaypoint(tile)) {
00412         NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
00413         if (fstd->v->current_order.IsType(OT_GOTO_WAYPOINT) && GetStationIndex(tile) == fstd->v->current_order.GetDestination()) {
00414           /* This waypoint is our destination; maybe this isn't an unreserved
00415            * one, so check that and if so see that as the last signal being
00416            * red. This way waypoints near stations should work better. */
00417           const Train *train = Train::From(fstd->v);
00418           CFollowTrackRail ft(train);
00419           TileIndex t = tile;
00420           Trackdir td = trackdir;
00421           while (ft.Follow(t, td)) {
00422             assert(t != ft.m_new_tile);
00423             t = ft.m_new_tile;
00424             if (KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
00425               /* We encountered a junction; it's going to be too complex to
00426                * handle this perfectly, so just bail out. There is no simple
00427                * free path, so try the other possibilities. */
00428               td = INVALID_TRACKDIR;
00429               break;
00430             }
00431             td = RemoveFirstTrackdir(&ft.m_new_td_bits);
00432             /* If this is a safe waiting position we're done searching for it */
00433             if (IsSafeWaitingPosition(train, t, td, true, _settings_game.pf.forbid_90_deg)) break;
00434           }
00435           if (td == INVALID_TRACKDIR ||
00436               !IsSafeWaitingPosition(train, t, td, true, _settings_game.pf.forbid_90_deg) ||
00437               !IsWaitingPositionFree(train, t, td, _settings_game.pf.forbid_90_deg)) {
00438             cost += _settings_game.pf.npf.npf_rail_lastred_penalty;
00439           }
00440         }
00441       }
00442       break;
00443 
00444     default:
00445       break;
00446   }
00447 
00448   /* Determine extra costs */
00449 
00450   /* Check for signals */
00451   if (IsTileType(tile, MP_RAILWAY)) {
00452     if (HasSignalOnTrackdir(tile, trackdir)) {
00453       SignalType sigtype = GetSignalType(tile, TrackdirToTrack(trackdir));
00454       /* Ordinary track with signals */
00455       if (GetSignalStateByTrackdir(tile, trackdir) == SIGNAL_STATE_RED) {
00456         /* Signal facing us is red */
00457         if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
00458           /* Penalize the first signal we
00459            * encounter, if it is red */
00460 
00461           /* Is this a presignal exit or combo? */
00462           if (!IsPbsSignal(sigtype)) {
00463             if (sigtype == SIGTYPE_EXIT || sigtype == SIGTYPE_COMBO) {
00464               /* Penalise exit and combo signals differently (heavier) */
00465               cost += _settings_game.pf.npf.npf_rail_firstred_exit_penalty;
00466             } else {
00467               cost += _settings_game.pf.npf.npf_rail_firstred_penalty;
00468             }
00469           }
00470         }
00471         /* Record the state of this signal. Path signals are assumed to
00472          * be green as the signal state of them has no meaning for this. */
00473         NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, !IsPbsSignal(sigtype));
00474       } else {
00475         /* Record the state of this signal */
00476         NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, false);
00477       }
00478       if (NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
00479         if (NPFGetFlag(current, NPF_FLAG_2ND_SIGNAL)) {
00480           NPFSetFlag(current, NPF_FLAG_3RD_SIGNAL, true);
00481         } else {
00482           NPFSetFlag(current, NPF_FLAG_2ND_SIGNAL, true);
00483         }
00484       } else {
00485         NPFSetFlag(current, NPF_FLAG_SEEN_SIGNAL, true);
00486       }
00487       NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_BLOCK, !IsPbsSignal(sigtype));
00488     }
00489 
00490     if (HasPbsSignalOnTrackdir(tile, ReverseTrackdir(trackdir)) && !NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL)) {
00491       cost += _settings_game.pf.npf.npf_rail_pbs_signal_back_penalty;
00492     }
00493   }
00494 
00495   /* Penalise the tile if it is a target tile and the last signal was
00496    * red */
00497   /* HACK: We create a new_node here so we can call EndNodeCheck. Ugly as hell
00498    * of course... */
00499   new_node.path.node = *current;
00500   if (as->EndNodeCheck(as, &new_node) == AYSTAR_FOUND_END_NODE && NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_RED)) {
00501     cost += _settings_game.pf.npf.npf_rail_lastred_penalty;
00502   }
00503 
00504   /* Check for slope */
00505   cost += NPFSlopeCost(current);
00506 
00507   /* Check for turns */
00508   if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction)) {
00509     cost += _settings_game.pf.npf.npf_rail_curve_penalty;
00510   }
00511   /* TODO, with realistic acceleration, also the amount of straight track between
00512    *      curves should be taken into account, as this affects the speed limit. */
00513 
00514   /* Check for reverse in depot */
00515   if (IsRailDepotTile(tile) && as->EndNodeCheck(as, &new_node) != AYSTAR_FOUND_END_NODE) {
00516     /* Penalise any depot tile that is not the last tile in the path. This
00517      * _should_ penalise every occurrence of reversing in a depot (and only
00518      * that) */
00519     cost += _settings_game.pf.npf.npf_rail_depot_reverse_penalty;
00520   }
00521 
00522   /* Check for occupied track */
00523   cost += NPFReservedTrackCost(current);
00524 
00525   NPFMarkTile(tile);
00526   DEBUG(npf, 4, "Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);
00527   return cost;
00528 }
00529 
00530 /* Will find any depot */
00531 static int32 NPFFindDepot(AyStar *as, OpenListNode *current)
00532 {
00533   /* It's not worth caching the result with NPF_FLAG_IS_TARGET here as below,
00534    * since checking the cache not that much faster than the actual check */
00535   return IsDepotTypeTile(current->path.node.tile, (TransportType)as->user_data[NPF_TYPE]) ?
00536     AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
00537 }
00538 
00540 static int32 NPFFindSafeTile(AyStar *as, OpenListNode *current)
00541 {
00542   const Train *v = Train::From(((NPFFindStationOrTileData *)as->user_target)->v);
00543 
00544   return (IsSafeWaitingPosition(v, current->path.node.tile, current->path.node.direction, true, _settings_game.pf.forbid_90_deg) &&
00545       IsWaitingPositionFree(v, current->path.node.tile, current->path.node.direction, _settings_game.pf.forbid_90_deg)) ?
00546         AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
00547 }
00548 
00549 /* Will find a station identified using the NPFFindStationOrTileData */
00550 static int32 NPFFindStationOrTile(AyStar *as, OpenListNode *current)
00551 {
00552   NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
00553   AyStarNode *node = &current->path.node;
00554   TileIndex tile = node->tile;
00555 
00556   if (fstd->station_index == INVALID_STATION && tile == fstd->dest_coords) return AYSTAR_FOUND_END_NODE;
00557 
00558   if (IsTileType(tile, MP_STATION) && GetStationIndex(tile) == fstd->station_index) {
00559     if (fstd->v->type == VEH_TRAIN) return AYSTAR_FOUND_END_NODE;
00560 
00561     assert(fstd->v->type == VEH_ROAD);
00562     /* Only if it is a valid station *and* we can stop there */
00563     if (GetStationType(tile) == fstd->station_type && (fstd->not_articulated || IsDriveThroughStopTile(tile))) return AYSTAR_FOUND_END_NODE;
00564   }
00565   return AYSTAR_DONE;
00566 }
00567 
00575 static const PathNode *FindSafePosition(PathNode *path, const Train *v)
00576 {
00577   /* If there is no signal, reserve the whole path. */
00578   PathNode *sig = path;
00579 
00580   for (; path->parent != NULL; path = path->parent) {
00581     if (IsSafeWaitingPosition(v, path->node.tile, path->node.direction, true, _settings_game.pf.forbid_90_deg)) {
00582       sig = path;
00583     }
00584   }
00585 
00586   return sig;
00587 }
00588 
00592 static void ClearPathReservation(const PathNode *start, const PathNode *end)
00593 {
00594   bool first_run = true;
00595   for (; start != end; start = start->parent) {
00596     if (IsRailStationTile(start->node.tile) && first_run) {
00597       SetRailStationPlatformReservation(start->node.tile, TrackdirToExitdir(start->node.direction), false);
00598     } else {
00599       UnreserveRailTrack(start->node.tile, TrackdirToTrack(start->node.direction));
00600     }
00601     first_run = false;
00602   }
00603 }
00604 
00611 static void NPFSaveTargetData(AyStar *as, OpenListNode *current)
00612 {
00613   NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
00614   ftd->best_trackdir = (Trackdir)current->path.node.user_data[NPF_TRACKDIR_CHOICE];
00615   ftd->best_path_dist = current->g;
00616   ftd->best_bird_dist = 0;
00617   ftd->node = current->path.node;
00618   ftd->res_okay = false;
00619 
00620   if (as->user_target != NULL && ((NPFFindStationOrTileData*)as->user_target)->reserve_path && as->user_data[NPF_TYPE] == TRANSPORT_RAIL) {
00621     /* Path reservation is requested. */
00622     const Train *v = Train::From(((NPFFindStationOrTileData *)as->user_target)->v);
00623 
00624     const PathNode *target = FindSafePosition(&current->path, v);
00625     ftd->node = target->node;
00626 
00627     /* If the target is a station skip to platform end. */
00628     if (IsRailStationTile(target->node.tile)) {
00629       DiagDirection dir = TrackdirToExitdir(target->node.direction);
00630       uint len = Station::GetByTile(target->node.tile)->GetPlatformLength(target->node.tile, dir);
00631       TileIndex end_tile = TILE_ADD(target->node.tile, (len - 1) * TileOffsByDiagDir(dir));
00632 
00633       /* Update only end tile, trackdir of a station stays the same. */
00634       ftd->node.tile = end_tile;
00635       if (!IsWaitingPositionFree(v, end_tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
00636       SetRailStationPlatformReservation(target->node.tile, dir, true);
00637       SetRailStationReservation(target->node.tile, false);
00638     } else {
00639       if (!IsWaitingPositionFree(v, target->node.tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
00640     }
00641 
00642     for (const PathNode *cur = target; cur->parent != NULL; cur = cur->parent) {
00643       if (!TryReserveRailTrack(cur->node.tile, TrackdirToTrack(cur->node.direction))) {
00644         /* Reservation failed, undo. */
00645         ClearPathReservation(target, cur);
00646         return;
00647       }
00648     }
00649 
00650     ftd->res_okay = true;
00651   }
00652 }
00653 
00663 static bool CanEnterTileOwnerCheck(Owner owner, TileIndex tile, DiagDirection enterdir)
00664 {
00665   if (IsTileType(tile, MP_RAILWAY) || // Rail tile (also rail depot)
00666       HasStationTileRail(tile) ||     // Rail station tile/waypoint
00667       IsRoadDepotTile(tile) ||        // Road depot tile
00668       IsStandardRoadStopTile(tile)) { // Road station tile (but not drive-through stops)
00669     return IsTileOwner(tile, owner);  // You need to own these tiles entirely to use them
00670   }
00671 
00672   switch (GetTileType(tile)) {
00673     case MP_ROAD:
00674       /* rail-road crossing : are we looking at the railway part? */
00675       if (IsLevelCrossing(tile) &&
00676           DiagDirToAxis(enterdir) != GetCrossingRoadAxis(tile)) {
00677         return IsTileOwner(tile, owner); // Railway needs owner check, while the street is public
00678       }
00679       break;
00680 
00681     case MP_TUNNELBRIDGE:
00682       if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
00683         return IsTileOwner(tile, owner);
00684       }
00685       break;
00686 
00687     default:
00688       break;
00689   }
00690 
00691   return true; // no need to check
00692 }
00693 
00694 
00698 static DiagDirection GetDepotDirection(TileIndex tile, TransportType type)
00699 {
00700   assert(IsDepotTypeTile(tile, type));
00701 
00702   switch (type) {
00703     case TRANSPORT_RAIL:  return GetRailDepotDirection(tile);
00704     case TRANSPORT_ROAD:  return GetRoadDepotDirection(tile);
00705     case TRANSPORT_WATER: return GetShipDepotDirection(tile);
00706     default: return INVALID_DIAGDIR; // Not reached
00707   }
00708 }
00709 
00711 static DiagDirection GetSingleTramBit(TileIndex tile)
00712 {
00713   if (IsNormalRoadTile(tile)) {
00714     RoadBits rb = GetRoadBits(tile, ROADTYPE_TRAM);
00715     switch (rb) {
00716       case ROAD_NW: return DIAGDIR_NW;
00717       case ROAD_SW: return DIAGDIR_SW;
00718       case ROAD_SE: return DIAGDIR_SE;
00719       case ROAD_NE: return DIAGDIR_NE;
00720       default: break;
00721     }
00722   }
00723   return INVALID_DIAGDIR;
00724 }
00725 
00736 static DiagDirection GetTileSingleEntry(TileIndex tile, TransportType type, uint subtype)
00737 {
00738   if (type != TRANSPORT_WATER && IsDepotTypeTile(tile, type)) return GetDepotDirection(tile, type);
00739 
00740   if (type == TRANSPORT_ROAD) {
00741     if (IsStandardRoadStopTile(tile)) return GetRoadStopDir(tile);
00742     if (HasBit(subtype, ROADTYPE_TRAM)) return GetSingleTramBit(tile);
00743   }
00744 
00745   return INVALID_DIAGDIR;
00746 }
00747 
00757 static inline bool ForceReverse(TileIndex tile, DiagDirection dir, TransportType type, uint subtype)
00758 {
00759   DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
00760   return single_entry != INVALID_DIAGDIR && single_entry != dir;
00761 }
00762 
00774 static bool CanEnterTile(TileIndex tile, DiagDirection dir, TransportType type, uint subtype, RailTypes railtypes, Owner owner)
00775 {
00776   /* Check tunnel entries and bridge ramps */
00777   if (IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(tile) != dir) return false;
00778 
00779   /* Test ownership */
00780   if (!CanEnterTileOwnerCheck(owner, tile, dir)) return false;
00781 
00782   /* check correct rail type (mono, maglev, etc) */
00783   if (type == TRANSPORT_RAIL) {
00784     RailType rail_type = GetTileRailType(tile);
00785     if (!HasBit(railtypes, rail_type)) return false;
00786   }
00787 
00788   /* Depots, standard roadstops and single tram bits can only be entered from one direction */
00789   DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
00790   if (single_entry != INVALID_DIAGDIR && single_entry != ReverseDiagDir(dir)) return false;
00791 
00792   return true;
00793 }
00794 
00806 static TrackdirBits GetDriveableTrackdirBits(TileIndex dst_tile, Trackdir src_trackdir, TransportType type, uint subtype)
00807 {
00808   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(dst_tile, type, subtype));
00809 
00810   if (trackdirbits == 0 && type == TRANSPORT_ROAD && HasBit(subtype, ROADTYPE_TRAM)) {
00811     /* GetTileTrackStatus() returns 0 for single tram bits.
00812      * As we cannot change it there (easily) without breaking something, change it here */
00813     switch (GetSingleTramBit(dst_tile)) {
00814       case DIAGDIR_NE:
00815       case DIAGDIR_SW:
00816         trackdirbits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
00817         break;
00818 
00819       case DIAGDIR_NW:
00820       case DIAGDIR_SE:
00821         trackdirbits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
00822         break;
00823 
00824       default: break;
00825     }
00826   }
00827 
00828   DEBUG(npf, 4, "Next node: (%d, %d) [%d], possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), dst_tile, trackdirbits);
00829 
00830   /* Select only trackdirs we can reach from our current trackdir */
00831   trackdirbits &= TrackdirReachesTrackdirs(src_trackdir);
00832 
00833   /* Filter out trackdirs that would make 90 deg turns for trains */
00834   if (_settings_game.pf.forbid_90_deg && (type == TRANSPORT_RAIL || type == TRANSPORT_WATER)) trackdirbits &= ~TrackdirCrossesTrackdirs(src_trackdir);
00835 
00836   DEBUG(npf, 6, "After filtering: (%d, %d), possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), trackdirbits);
00837 
00838   return trackdirbits;
00839 }
00840 
00841 
00842 /* Will just follow the results of GetTileTrackStatus concerning where we can
00843  * go and where not. Uses AyStar.user_data[NPF_TYPE] as the transport type and
00844  * an argument to GetTileTrackStatus. Will skip tunnels, meaning that the
00845  * entry and exit are neighbours. Will fill
00846  * AyStarNode.user_data[NPF_TRACKDIR_CHOICE] with an appropriate value, and
00847  * copy AyStarNode.user_data[NPF_NODE_FLAGS] from the parent */
00848 static void NPFFollowTrack(AyStar *aystar, OpenListNode *current)
00849 {
00850   /* We leave src_tile on track src_trackdir in direction src_exitdir */
00851   Trackdir src_trackdir = current->path.node.direction;
00852   TileIndex src_tile = current->path.node.tile;
00853   DiagDirection src_exitdir = TrackdirToExitdir(src_trackdir);
00854 
00855   /* Is src_tile valid, and can be used?
00856    * When choosing track on a junction src_tile is the tile neighboured to the junction wrt. exitdir.
00857    * 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. */
00858   bool ignore_src_tile = (current->path.parent == NULL && NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_START_TILE));
00859 
00860   /* Information about the vehicle: TransportType (road/rail/water) and SubType (compatible rail/road types) */
00861   TransportType type = (TransportType)aystar->user_data[NPF_TYPE];
00862   uint subtype = aystar->user_data[NPF_SUB_TYPE];
00863 
00864   /* Initialize to 0, so we can jump out (return) somewhere an have no neighbours */
00865   aystar->num_neighbours = 0;
00866   DEBUG(npf, 4, "Expanding: (%d, %d, %d) [%d]", TileX(src_tile), TileY(src_tile), src_trackdir, src_tile);
00867 
00868   /* We want to determine the tile we arrive, and which choices we have there */
00869   TileIndex dst_tile;
00870   TrackdirBits trackdirbits;
00871 
00872   /* Find dest tile */
00873   if (ignore_src_tile) {
00874     /* Do not perform any checks that involve src_tile */
00875     dst_tile = src_tile + TileOffsByDiagDir(src_exitdir);
00876     trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
00877   } else if (IsTileType(src_tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(src_tile) == src_exitdir) {
00878     /* We drive through the wormhole and arrive on the other side */
00879     dst_tile = GetOtherTunnelBridgeEnd(src_tile);
00880     trackdirbits = TrackdirToTrackdirBits(src_trackdir);
00881   } else if (ForceReverse(src_tile, src_exitdir, type, subtype)) {
00882     /* We can only reverse on this tile */
00883     dst_tile = src_tile;
00884     src_trackdir = ReverseTrackdir(src_trackdir);
00885     trackdirbits = TrackdirToTrackdirBits(src_trackdir);
00886   } else {
00887     /* We leave src_tile in src_exitdir and reach dst_tile */
00888     dst_tile = AddTileIndexDiffCWrap(src_tile, TileIndexDiffCByDiagDir(src_exitdir));
00889 
00890     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;
00891 
00892     if (dst_tile == INVALID_TILE) {
00893       /* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
00894       if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
00895 
00896       dst_tile = src_tile;
00897       src_trackdir = ReverseTrackdir(src_trackdir);
00898     }
00899 
00900     trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
00901 
00902     if (trackdirbits == 0) {
00903       /* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
00904       if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
00905 
00906       dst_tile = src_tile;
00907       src_trackdir = ReverseTrackdir(src_trackdir);
00908 
00909       trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
00910     }
00911   }
00912 
00913   if (NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_RESERVED)) {
00914     /* Mask out any reserved tracks. */
00915     TrackBits reserved = GetReservedTrackbits(dst_tile);
00916     trackdirbits &= ~TrackBitsToTrackdirBits(reserved);
00917 
00918     Track t;
00919     FOR_EACH_SET_TRACK(t, TrackdirBitsToTrackBits(trackdirbits)) {
00920       if (TracksOverlap(reserved | TrackToTrackBits(t))) trackdirbits &= ~TrackToTrackdirBits(t);
00921     }
00922   }
00923 
00924   /* Enumerate possible track */
00925   uint i = 0;
00926   while (trackdirbits != 0) {
00927     Trackdir dst_trackdir = RemoveFirstTrackdir(&trackdirbits);
00928     DEBUG(npf, 5, "Expanded into trackdir: %d, remaining trackdirs: 0x%X", dst_trackdir, trackdirbits);
00929 
00930     /* Tile with signals? */
00931     if (IsTileType(dst_tile, MP_RAILWAY) && GetRailTileType(dst_tile) == RAIL_TILE_SIGNALS) {
00932       if (HasSignalOnTrackdir(dst_tile, ReverseTrackdir(dst_trackdir)) && !HasSignalOnTrackdir(dst_tile, dst_trackdir) && IsOnewaySignal(dst_tile, TrackdirToTrack(dst_trackdir))) {
00933         /* If there's a one-way signal not pointing towards us, stop going in this direction. */
00934         break;
00935       }
00936     }
00937     {
00938       /* We've found ourselves a neighbour :-) */
00939       AyStarNode *neighbour = &aystar->neighbours[i];
00940       neighbour->tile = dst_tile;
00941       neighbour->direction = dst_trackdir;
00942       /* Save user data */
00943       neighbour->user_data[NPF_NODE_FLAGS] = current->path.node.user_data[NPF_NODE_FLAGS];
00944       NPFFillTrackdirChoice(neighbour, current);
00945     }
00946     i++;
00947   }
00948   aystar->num_neighbours = i;
00949 }
00950 
00951 /*
00952  * Plan a route to the specified target (which is checked by target_proc),
00953  * from start1 and if not NULL, from start2 as well. The type of transport we
00954  * are checking is in type. reverse_penalty is applied to all routes that
00955  * originate from the second start node.
00956  * When we are looking for one specific target (optionally multiple tiles), we
00957  * should use a good heuristic to perform aystar search. When we search for
00958  * multiple targets that are spread around, we should perform a breadth first
00959  * search by specifiying CalcZero as our heuristic.
00960  */
00961 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)
00962 {
00963   int r;
00964   NPFFoundTargetData result;
00965 
00966   /* Initialize procs */
00967   _npf_aystar.CalculateH = heuristic_proc;
00968   _npf_aystar.EndNodeCheck = target_proc;
00969   _npf_aystar.FoundEndNode = NPFSaveTargetData;
00970   _npf_aystar.GetNeighbours = NPFFollowTrack;
00971   switch (type) {
00972     default: NOT_REACHED();
00973     case TRANSPORT_RAIL:  _npf_aystar.CalculateG = NPFRailPathCost;  break;
00974     case TRANSPORT_ROAD:  _npf_aystar.CalculateG = NPFRoadPathCost;  break;
00975     case TRANSPORT_WATER: _npf_aystar.CalculateG = NPFWaterPathCost; break;
00976   }
00977 
00978   /* Initialize Start Node(s) */
00979   start1->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
00980   start1->user_data[NPF_NODE_FLAGS] = 0;
00981   NPFSetFlag(start1, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile1);
00982   _npf_aystar.AddStartNode(start1, 0);
00983   if (start2 != NULL) {
00984     start2->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
00985     start2->user_data[NPF_NODE_FLAGS] = 0;
00986     NPFSetFlag(start2, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile2);
00987     NPFSetFlag(start2, NPF_FLAG_REVERSE, true);
00988     _npf_aystar.AddStartNode(start2, reverse_penalty);
00989   }
00990 
00991   /* Initialize result */
00992   result.best_bird_dist = UINT_MAX;
00993   result.best_path_dist = UINT_MAX;
00994   result.best_trackdir  = INVALID_TRACKDIR;
00995   result.node.tile      = INVALID_TILE;
00996   result.res_okay       = false;
00997   _npf_aystar.user_path = &result;
00998 
00999   /* Initialize target */
01000   _npf_aystar.user_target = target;
01001 
01002   /* Initialize user_data */
01003   _npf_aystar.user_data[NPF_TYPE] = type;
01004   _npf_aystar.user_data[NPF_SUB_TYPE] = sub_type;
01005   _npf_aystar.user_data[NPF_OWNER] = owner;
01006   _npf_aystar.user_data[NPF_RAILTYPES] = railtypes;
01007 
01008   /* GO! */
01009   r = _npf_aystar.Main();
01010   assert(r != AYSTAR_STILL_BUSY);
01011 
01012   if (result.best_bird_dist != 0) {
01013     if (target != NULL) {
01014       DEBUG(npf, 1, "Could not find route to tile 0x%X from 0x%X.", target->dest_coords, start1->tile);
01015     } else {
01016       /* Assumption: target == NULL, so we are looking for a depot */
01017       DEBUG(npf, 1, "Could not find route to a depot from tile 0x%X.", start1->tile);
01018     }
01019 
01020   }
01021   return result;
01022 }
01023 
01024 /* Will search as below, but with two start nodes, the second being the
01025  * reverse. Look at the NPF_FLAG_REVERSE flag in the result node to see which
01026  * direction was taken (NPFGetFlag(result.node, NPF_FLAG_REVERSE)) */
01027 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)
01028 {
01029   AyStarNode start1;
01030   AyStarNode start2;
01031 
01032   start1.tile = tile1;
01033   start2.tile = tile2;
01034   /* We set this in case the target is also the start tile, we will just
01035    * return a not found then */
01036   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01037   start1.direction = trackdir1;
01038   start2.direction = trackdir2;
01039   start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01040 
01041   return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, target, NPFFindStationOrTile, NPFCalcStationOrTileHeuristic, type, sub_type, owner, railtypes, 0);
01042 }
01043 
01044 /* Will search from the given tile and direction, for a route to the given
01045  * station for the given transport type. See the declaration of
01046  * NPFFoundTargetData above for the meaning of the result. */
01047 static NPFFoundTargetData NPFRouteToStationOrTile(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes)
01048 {
01049   return NPFRouteToStationOrTileTwoWay(tile, trackdir, ignore_start_tile, INVALID_TILE, INVALID_TRACKDIR, false, target, type, sub_type, owner, railtypes);
01050 }
01051 
01052 /* Search using breadth first. Good for little track choice and inaccurate
01053  * heuristic, such as railway/road with two start nodes, the second being the reverse. Call
01054  * NPFGetFlag(result.node, NPF_FLAG_REVERSE) to see from which node the path
01055  * orginated. All pathfs from the second node will have the given
01056  * reverse_penalty applied (NPF_TILE_LENGTH is the equivalent of one full
01057  * tile).
01058  */
01059 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)
01060 {
01061   AyStarNode start1;
01062   AyStarNode start2;
01063 
01064   start1.tile = tile1;
01065   start2.tile = tile2;
01066   /* We set this in case the target is also the start tile, we will just
01067    * return a not found then */
01068   start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01069   start1.direction = trackdir1;
01070   start2.direction = trackdir2;
01071   start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
01072 
01073   /* perform a breadth first search. Target is NULL,
01074    * since we are just looking for any depot...*/
01075   return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, target, NPFFindDepot, NPFCalcZero, type, sub_type, owner, railtypes, reverse_penalty);
01076 }
01077 
01078 void InitializeNPF()
01079 {
01080   static bool first_init = true;
01081   if (first_init) {
01082     first_init = false;
01083     _npf_aystar.Init(NPFHash, NPF_HASH_SIZE);
01084   } else {
01085     _npf_aystar.Clear();
01086   }
01087   _npf_aystar.loops_per_tick = 0;
01088   _npf_aystar.max_path_cost = 0;
01089   //_npf_aystar.max_search_nodes = 0;
01090   /* We will limit the number of nodes for now, until we have a better
01091    * solution to really fix performance */
01092   _npf_aystar.max_search_nodes = _settings_game.pf.npf.npf_max_search_nodes;
01093 }
01094 
01095 static void NPFFillWithOrderData(NPFFindStationOrTileData *fstd, const Vehicle *v, bool reserve_path = false)
01096 {
01097   /* Ships don't really reach their stations, but the tile in front. So don't
01098    * save the station id for ships. For roadvehs we don't store it either,
01099    * because multistop depends on vehicles actually reaching the exact
01100    * dest_tile, not just any stop of that station.
01101    * So only for train orders to stations we fill fstd->station_index, for all
01102    * others only dest_coords */
01103   if (v->type != VEH_SHIP && (v->current_order.IsType(OT_GOTO_STATION) || v->current_order.IsType(OT_GOTO_WAYPOINT))) {
01104     assert(v->IsGroundVehicle());
01105     fstd->station_index = v->current_order.GetDestination();
01106     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);
01107     fstd->not_articulated = v->type == VEH_ROAD && !RoadVehicle::From(v)->HasArticulatedPart();
01108     /* Let's take the closest tile of the station as our target for vehicles */
01109     fstd->dest_coords = CalcClosestStationTile(fstd->station_index, v->tile, fstd->station_type);
01110   } else {
01111     fstd->dest_coords = v->dest_tile;
01112     fstd->station_index = INVALID_STATION;
01113   }
01114   fstd->reserve_path = reserve_path;
01115   fstd->v = v;
01116 }
01117 
01118 /*** Road vehicles ***/
01119 
01120 FindDepotData NPFRoadVehicleFindNearestDepot(const RoadVehicle *v, int max_penalty)
01121 {
01122   Trackdir trackdir = v->GetVehicleTrackdir();
01123 
01124   NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, v->tile, ReverseTrackdir(trackdir), false, NULL, TRANSPORT_ROAD, v->compatible_roadtypes, v->owner, INVALID_RAILTYPES, 0);
01125 
01126   if (ftd.best_bird_dist != 0) return FindDepotData();
01127 
01128   /* Found target */
01129   /* Our caller expects a number of tiles, so we just approximate that
01130    * number by this. It might not be completely what we want, but it will
01131    * work for now :-) We can possibly change this when the old pathfinder
01132    * is removed. */
01133   return FindDepotData(ftd.node.tile, ftd.best_path_dist);
01134 }
01135 
01136 Trackdir NPFRoadVehicleChooseTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool &path_found)
01137 {
01138   NPFFindStationOrTileData fstd;
01139 
01140   NPFFillWithOrderData(&fstd, v);
01141   Trackdir trackdir = DiagDirToDiagTrackdir(enterdir);
01142 
01143   NPFFoundTargetData ftd = NPFRouteToStationOrTile(tile - TileOffsByDiagDir(enterdir), trackdir, true, &fstd, TRANSPORT_ROAD, v->compatible_roadtypes, v->owner, INVALID_RAILTYPES);
01144   if (ftd.best_trackdir == INVALID_TRACKDIR) {
01145     /* We are already at our target. Just do something
01146      * @todo: maybe display error?
01147      * @todo: go straight ahead if possible? */
01148     path_found = true;
01149     return (Trackdir)FindFirstBit2x64(trackdirs);
01150   }
01151 
01152   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
01153    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
01154    * we did not find our target, but ftd.best_trackdir contains the direction leading
01155    * to the tile closest to our target. */
01156   path_found = (ftd.best_bird_dist == 0);
01157   return ftd.best_trackdir;
01158 }
01159 
01160 /*** Ships ***/
01161 
01162 Track NPFShipChooseTrack(const Ship *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found)
01163 {
01164   NPFFindStationOrTileData fstd;
01165   Trackdir trackdir = v->GetVehicleTrackdir();
01166   assert(trackdir != INVALID_TRACKDIR); // Check that we are not in a depot
01167 
01168   NPFFillWithOrderData(&fstd, v);
01169 
01170   NPFFoundTargetData ftd = NPFRouteToStationOrTile(tile - TileOffsByDiagDir(enterdir), trackdir, true, &fstd, TRANSPORT_WATER, 0, v->owner, INVALID_RAILTYPES);
01171 
01172   /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
01173    * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
01174    * we did not find our target, but ftd.best_trackdir contains the direction leading
01175    * to the tile closest to our target. */
01176   path_found = (ftd.best_bird_dist == 0);
01177   if (ftd.best_trackdir == 0xff) return INVALID_TRACK;
01178   return TrackdirToTrack(ftd.best_trackdir);
01179 }
01180 
01181 /*** Trains ***/
01182 
01183 FindDepotData NPFTrainFindNearestDepot(const Train *v, int max_penalty)
01184 {
01185   const Train *last = v->Last();
01186   Trackdir trackdir = v->GetVehicleTrackdir();
01187   Trackdir trackdir_rev = ReverseTrackdir(last->GetVehicleTrackdir());
01188   NPFFindStationOrTileData fstd;
01189   fstd.v = v;
01190   fstd.reserve_path = false;
01191 
01192   assert(trackdir != INVALID_TRACKDIR);
01193   NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, &fstd, 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_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     path_found = true;
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   path_found = (ftd.best_bird_dist == 0);
01275   /* Discard enterdir information, making it a normal track */
01276   return TrackdirToTrack(ftd.best_trackdir);
01277 }