yapf_costrail.hpp

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00001 /* $Id: yapf_costrail.hpp 18535 2009-12-19 15:30:24Z 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 #ifndef  YAPF_COSTRAIL_HPP
00013 #define  YAPF_COSTRAIL_HPP
00014 
00015 #include "../../pbs.h"
00016 
00017 template <class Types>
00018 class CYapfCostRailT
00019   : public CYapfCostBase
00020   , public CostRailSettings
00021 {
00022 public:
00023   typedef typename Types::Tpf Tpf;              
00024   typedef typename Types::TrackFollower TrackFollower;
00025   typedef typename Types::NodeList::Titem Node; 
00026   typedef typename Node::Key Key;               
00027   typedef typename Node::CachedData CachedData;
00028 
00029 protected:
00030 
00031   /* Structure used inside PfCalcCost() to keep basic tile information. */
00032   struct TILE {
00033     TileIndex   tile;
00034     Trackdir    td;
00035     TileType    tile_type;
00036     RailType    rail_type;
00037 
00038     TILE()
00039     {
00040       tile = INVALID_TILE;
00041       td = INVALID_TRACKDIR;
00042       tile_type = MP_VOID;
00043       rail_type = INVALID_RAILTYPE;
00044     }
00045 
00046     TILE(TileIndex tile, Trackdir td)
00047     {
00048       this->tile = tile;
00049       this->td = td;
00050       this->tile_type = GetTileType(tile);
00051       this->rail_type = GetTileRailType(tile);
00052     }
00053 
00054     TILE(const TILE &src)
00055     {
00056       tile = src.tile;
00057       td = src.td;
00058       tile_type = src.tile_type;
00059       rail_type = src.rail_type;
00060     }
00061   };
00062 
00063 protected:
00068   int           m_max_cost;
00069   CBlobT<int>   m_sig_look_ahead_costs;
00070   bool          m_disable_cache;
00071 
00072 public:
00073   bool          m_stopped_on_first_two_way_signal;
00074 protected:
00075 
00076   static const int s_max_segment_cost = 10000;
00077 
00078   CYapfCostRailT()
00079     : m_max_cost(0)
00080     , m_disable_cache(false)
00081     , m_stopped_on_first_two_way_signal(false)
00082   {
00083     /* pre-compute look-ahead penalties into array */
00084     int p0 = Yapf().PfGetSettings().rail_look_ahead_signal_p0;
00085     int p1 = Yapf().PfGetSettings().rail_look_ahead_signal_p1;
00086     int p2 = Yapf().PfGetSettings().rail_look_ahead_signal_p2;
00087     int *pen = m_sig_look_ahead_costs.GrowSizeNC(Yapf().PfGetSettings().rail_look_ahead_max_signals);
00088     for (uint i = 0; i < Yapf().PfGetSettings().rail_look_ahead_max_signals; i++) {
00089       pen[i] = p0 + i * (p1 + i * p2);
00090     }
00091   }
00092 
00094   Tpf& Yapf()
00095   {
00096     return *static_cast<Tpf*>(this);
00097   }
00098 
00099 public:
00100   FORCEINLINE int SlopeCost(TileIndex tile, Trackdir td)
00101   {
00102     CPerfStart perf_cost(Yapf().m_perf_slope_cost);
00103     if (!stSlopeCost(tile, td)) return 0;
00104     return Yapf().PfGetSettings().rail_slope_penalty;
00105   }
00106 
00107   FORCEINLINE int CurveCost(Trackdir td1, Trackdir td2)
00108   {
00109     assert(IsValidTrackdir(td1));
00110     assert(IsValidTrackdir(td2));
00111     int cost = 0;
00112     if (TrackFollower::Allow90degTurns()
00113         && ((TrackdirToTrackdirBits(td2) & (TrackdirBits)TrackdirCrossesTrackdirs(td1)) != 0)) {
00114       /* 90-deg curve penalty */
00115       cost += Yapf().PfGetSettings().rail_curve90_penalty;
00116     } else if (td2 != NextTrackdir(td1)) {
00117       /* 45-deg curve penalty */
00118       cost += Yapf().PfGetSettings().rail_curve45_penalty;
00119     }
00120     return cost;
00121   }
00122 
00123   FORCEINLINE int SwitchCost(TileIndex tile1, TileIndex tile2, DiagDirection exitdir)
00124   {
00125     if (IsPlainRailTile(tile1) && IsPlainRailTile(tile2)) {
00126       bool t1 = KillFirstBit(GetTrackBits(tile1) & DiagdirReachesTracks(ReverseDiagDir(exitdir))) != TRACK_BIT_NONE;
00127       bool t2 = KillFirstBit(GetTrackBits(tile2) & DiagdirReachesTracks(exitdir)) != TRACK_BIT_NONE;
00128       if (t1 && t2) return Yapf().PfGetSettings().rail_doubleslip_penalty;
00129     }
00130     return 0;
00131   }
00132 
00134   FORCEINLINE int OneTileCost(TileIndex& tile, Trackdir trackdir)
00135   {
00136     int cost = 0;
00137     /* set base cost */
00138     if (IsDiagonalTrackdir(trackdir)) {
00139       cost += YAPF_TILE_LENGTH;
00140       switch (GetTileType(tile)) {
00141         case MP_ROAD:
00142           /* Increase the cost for level crossings */
00143           if (IsLevelCrossing(tile)) {
00144             cost += Yapf().PfGetSettings().rail_crossing_penalty;
00145           }
00146           break;
00147 
00148         default:
00149           break;
00150       }
00151     } else {
00152       /* non-diagonal trackdir */
00153       cost = YAPF_TILE_CORNER_LENGTH;
00154     }
00155     return cost;
00156   }
00157 
00159   FORCEINLINE bool IsAnyStationTileReserved(TileIndex tile, Trackdir trackdir, int skipped)
00160   {
00161     TileIndexDiff diff = TileOffsByDiagDir(TrackdirToExitdir(ReverseTrackdir(trackdir)));
00162     for (; skipped >= 0; skipped--, tile += diff) {
00163       if (HasStationReservation(tile)) return true;
00164     }
00165     return false;
00166   }
00167 
00169   FORCEINLINE int ReservationCost(Node& n, TileIndex tile, Trackdir trackdir, int skipped)
00170   {
00171     if (n.m_num_signals_passed >= m_sig_look_ahead_costs.Size() / 2) return 0;
00172     if (!IsPbsSignal(n.m_last_signal_type)) return 0;
00173 
00174     if (IsRailStationTile(tile) && IsAnyStationTileReserved(tile, trackdir, skipped)) {
00175       return Yapf().PfGetSettings().rail_pbs_station_penalty * (skipped + 1);
00176     } else if (TrackOverlapsTracks(GetReservedTrackbits(tile), TrackdirToTrack(trackdir))) {
00177       int cost = Yapf().PfGetSettings().rail_pbs_cross_penalty;
00178       if (!IsDiagonalTrackdir(trackdir)) cost = (cost * YAPF_TILE_CORNER_LENGTH) / YAPF_TILE_LENGTH;
00179       return cost * (skipped + 1);
00180     }
00181     return 0;
00182   }
00183 
00184   int SignalCost(Node& n, TileIndex tile, Trackdir trackdir)
00185   {
00186     int cost = 0;
00187     /* if there is one-way signal in the opposite direction, then it is not our way */
00188     CPerfStart perf_cost(Yapf().m_perf_other_cost);
00189     if (IsTileType(tile, MP_RAILWAY)) {
00190       bool has_signal_against = HasSignalOnTrackdir(tile, ReverseTrackdir(trackdir));
00191       bool has_signal_along = HasSignalOnTrackdir(tile, trackdir);
00192       if (has_signal_against && !has_signal_along && IsOnewaySignal(tile, TrackdirToTrack(trackdir))) {
00193         /* one-way signal in opposite direction */
00194         n.m_segment->m_end_segment_reason |= ESRB_DEAD_END;
00195       } else {
00196         if (has_signal_along) {
00197           SignalState sig_state = GetSignalStateByTrackdir(tile, trackdir);
00198           SignalType sig_type = GetSignalType(tile, TrackdirToTrack(trackdir));
00199 
00200           n.m_last_signal_type = sig_type;
00201 
00202           /* cache the look-ahead polynomial constant only if we didn't pass more signals than the look-ahead limit is */
00203           int look_ahead_cost = (n.m_num_signals_passed < m_sig_look_ahead_costs.Size()) ? m_sig_look_ahead_costs.Data()[n.m_num_signals_passed] : 0;
00204           if (sig_state != SIGNAL_STATE_RED) {
00205             /* green signal */
00206             n.flags_u.flags_s.m_last_signal_was_red = false;
00207             /* negative look-ahead red-signal penalties would cause problems later, so use them as positive penalties for green signal */
00208             if (look_ahead_cost < 0) {
00209               /* add its negation to the cost */
00210               cost -= look_ahead_cost;
00211             }
00212           } else {
00213             /* we have a red signal in our direction
00214              * was it first signal which is two-way? */
00215             if (!IsPbsSignal(sig_type) && Yapf().TreatFirstRedTwoWaySignalAsEOL() && n.flags_u.flags_s.m_choice_seen && has_signal_against && n.m_num_signals_passed == 0) {
00216               /* yes, the first signal is two-way red signal => DEAD END */
00217               n.m_segment->m_end_segment_reason |= ESRB_DEAD_END;
00218               Yapf().m_stopped_on_first_two_way_signal = true;
00219               return -1;
00220             }
00221             n.m_last_red_signal_type = sig_type;
00222             n.flags_u.flags_s.m_last_signal_was_red = true;
00223 
00224             /* look-ahead signal penalty */
00225             if (!IsPbsSignal(sig_type) && look_ahead_cost > 0) {
00226               /* add the look ahead penalty only if it is positive */
00227               cost += look_ahead_cost;
00228             }
00229 
00230             /* special signal penalties */
00231             if (n.m_num_signals_passed == 0) {
00232               switch (sig_type) {
00233                 case SIGTYPE_COMBO:
00234                 case SIGTYPE_EXIT:   cost += Yapf().PfGetSettings().rail_firstred_exit_penalty; break; // first signal is red pre-signal-exit
00235                 case SIGTYPE_NORMAL:
00236                 case SIGTYPE_ENTRY:  cost += Yapf().PfGetSettings().rail_firstred_penalty; break;
00237                 default: break;
00238               }
00239             }
00240           }
00241 
00242           n.m_num_signals_passed++;
00243           n.m_segment->m_last_signal_tile = tile;
00244           n.m_segment->m_last_signal_td = trackdir;
00245         }
00246 
00247         if (has_signal_against && IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) {
00248           cost += n.m_num_signals_passed < Yapf().PfGetSettings().rail_look_ahead_max_signals ? Yapf().PfGetSettings().rail_pbs_signal_back_penalty : 0;
00249         }
00250       }
00251     }
00252     return cost;
00253   }
00254 
00255   FORCEINLINE int PlatformLengthPenalty(int platform_length)
00256   {
00257     int cost = 0;
00258     const Train *v = Yapf().GetVehicle();
00259     assert(v != NULL);
00260     assert(v->type == VEH_TRAIN);
00261     assert(v->tcache.cached_total_length != 0);
00262     int missing_platform_length = (v->tcache.cached_total_length + TILE_SIZE - 1) / TILE_SIZE - platform_length;
00263     if (missing_platform_length < 0) {
00264       /* apply penalty for longer platform than needed */
00265       cost += Yapf().PfGetSettings().rail_longer_platform_penalty + Yapf().PfGetSettings().rail_longer_platform_per_tile_penalty * -missing_platform_length;
00266     } else if (missing_platform_length > 0) {
00267       /* apply penalty for shorter platform than needed */
00268       cost += Yapf().PfGetSettings().rail_shorter_platform_penalty + Yapf().PfGetSettings().rail_shorter_platform_per_tile_penalty * missing_platform_length;
00269     }
00270     return cost;
00271   }
00272 
00273 public:
00274   FORCEINLINE void SetMaxCost(int max_cost)
00275   {
00276     m_max_cost = max_cost;
00277   }
00278 
00282   FORCEINLINE bool PfCalcCost(Node &n, const TrackFollower *tf)
00283   {
00284     assert(!n.flags_u.flags_s.m_targed_seen);
00285     assert(tf->m_new_tile == n.m_key.m_tile);
00286     assert((TrackdirToTrackdirBits(n.m_key.m_td) & tf->m_new_td_bits) != TRACKDIR_BIT_NONE);
00287 
00288     CPerfStart perf_cost(Yapf().m_perf_cost);
00289 
00290     /* Does the node have some parent node? */
00291     bool has_parent = (n.m_parent != NULL);
00292 
00293     /* Do we already have a cached segment? */
00294     CachedData &segment = *n.m_segment;
00295     bool is_cached_segment = (segment.m_cost >= 0);
00296 
00297     int parent_cost = has_parent ? n.m_parent->m_cost : 0;
00298 
00299     /* Each node cost contains 2 or 3 main components:
00300      *  1. Transition cost - cost of the move from previous node (tile):
00301      *    - curve cost (or zero for straight move)
00302      *  2. Tile cost:
00303      *    - base tile cost
00304      *      - YAPF_TILE_LENGTH for diagonal tiles
00305      *      - YAPF_TILE_CORNER_LENGTH for non-diagonal tiles
00306      *    - tile penalties
00307      *      - tile slope penalty (upward slopes)
00308      *      - red signal penalty
00309      *      - level crossing penalty
00310      *      - speed-limit penalty (bridges)
00311      *      - station platform penalty
00312      *      - penalty for reversing in the depot
00313      *      - etc.
00314      *  3. Extra cost (applies to the last node only)
00315      *    - last red signal penalty
00316      *    - penalty for too long or too short platform on the destination station
00317      */
00318     int transition_cost = 0;
00319     int extra_cost = 0;
00320 
00321     /* Segment: one or more tiles connected by contiguous tracks of the same type.
00322      * Each segment cost includes 'Tile cost' for all its tiles (including the first
00323      * and last), and the 'Transition cost' between its tiles. The first transition
00324      * cost of segment entry (move from the 'parent' node) is not included!
00325      */
00326     int segment_entry_cost = 0;
00327     int segment_cost = 0;
00328 
00329     const Train *v = Yapf().GetVehicle();
00330 
00331     /* start at n.m_key.m_tile / n.m_key.m_td and walk to the end of segment */
00332     TILE cur(n.m_key.m_tile, n.m_key.m_td);
00333 
00334     /* the previous tile will be needed for transition cost calculations */
00335     TILE prev = !has_parent ? TILE() : TILE(n.m_parent->GetLastTile(), n.m_parent->GetLastTrackdir());
00336 
00337     EndSegmentReasonBits end_segment_reason = ESRB_NONE;
00338 
00339     TrackFollower tf_local(v, Yapf().GetCompatibleRailTypes(), &Yapf().m_perf_ts_cost);
00340 
00341     if (!has_parent) {
00342       /* We will jump to the middle of the cost calculator assuming that segment cache is not used. */
00343       assert(!is_cached_segment);
00344       /* Skip the first transition cost calculation. */
00345       goto no_entry_cost;
00346     }
00347 
00348     for (;;) {
00349       /* Transition cost (cost of the move from previous tile) */
00350       transition_cost = Yapf().CurveCost(prev.td, cur.td);
00351       transition_cost += Yapf().SwitchCost(prev.tile, cur.tile, TrackdirToExitdir(prev.td));
00352 
00353       /* First transition cost counts against segment entry cost, other transitions
00354        * inside segment will come to segment cost (and will be cached) */
00355       if (segment_cost == 0) {
00356         /* We just entered the loop. First transition cost goes to segment entry cost)*/
00357         segment_entry_cost = transition_cost;
00358         transition_cost = 0;
00359 
00360         /* It is the right time now to look if we can reuse the cached segment cost. */
00361         if (is_cached_segment) {
00362           /* Yes, we already know the segment cost. */
00363           segment_cost = segment.m_cost;
00364           /* We know also the reason why the segment ends. */
00365           end_segment_reason = segment.m_end_segment_reason;
00366           /* We will need also some information about the last signal (if it was red). */
00367           if (segment.m_last_signal_tile != INVALID_TILE) {
00368             assert(HasSignalOnTrackdir(segment.m_last_signal_tile, segment.m_last_signal_td));
00369             SignalState sig_state = GetSignalStateByTrackdir(segment.m_last_signal_tile, segment.m_last_signal_td);
00370             bool is_red = (sig_state == SIGNAL_STATE_RED);
00371             n.flags_u.flags_s.m_last_signal_was_red = is_red;
00372             if (is_red) {
00373               n.m_last_red_signal_type = GetSignalType(segment.m_last_signal_tile, TrackdirToTrack(segment.m_last_signal_td));
00374             }
00375           }
00376           /* No further calculation needed. */
00377           cur = TILE(n.GetLastTile(), n.GetLastTrackdir());
00378           break;
00379         }
00380       } else {
00381         /* Other than first transition cost count as the regular segment cost. */
00382         segment_cost += transition_cost;
00383       }
00384 
00385 no_entry_cost: // jump here at the beginning if the node has no parent (it is the first node)
00386 
00387       /* All other tile costs will be calculated here. */
00388       segment_cost += Yapf().OneTileCost(cur.tile, cur.td);
00389 
00390       /* If we skipped some tunnel/bridge/station tiles, add their base cost */
00391       segment_cost += YAPF_TILE_LENGTH * tf->m_tiles_skipped;
00392 
00393       /* Slope cost. */
00394       segment_cost += Yapf().SlopeCost(cur.tile, cur.td);
00395 
00396       /* Signal cost (routine can modify segment data). */
00397       segment_cost += Yapf().SignalCost(n, cur.tile, cur.td);
00398 
00399       /* Reserved tiles. */
00400       segment_cost += Yapf().ReservationCost(n, cur.tile, cur.td, tf->m_tiles_skipped);
00401 
00402       end_segment_reason = segment.m_end_segment_reason;
00403 
00404       /* Tests for 'potential target' reasons to close the segment. */
00405       if (cur.tile == prev.tile) {
00406         /* Penalty for reversing in a depot. */
00407         assert(IsRailDepot(cur.tile));
00408         segment_cost += Yapf().PfGetSettings().rail_depot_reverse_penalty;
00409         /* We will end in this pass (depot is possible target) */
00410         end_segment_reason |= ESRB_DEPOT;
00411 
00412       } else if (cur.tile_type == MP_STATION && IsRailWaypoint(cur.tile)) {
00413         if (v->current_order.IsType(OT_GOTO_WAYPOINT) && GetStationIndex(cur.tile) == 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           CFollowTrackRail ft(v);
00418           TileIndex t = cur.tile;
00419           Trackdir td = cur.td;
00420           while (ft.Follow(t, td)) {
00421             assert(t != ft.m_new_tile);
00422             t = ft.m_new_tile;
00423             if (KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
00424               /* We encountered a junction; it's going to be too complex to
00425                * handle this perfectly, so just bail out. There is no simple
00426                * free path, so try the other possibilities. */
00427               td = INVALID_TRACKDIR;
00428               break;
00429             }
00430             td = RemoveFirstTrackdir(&ft.m_new_td_bits);
00431             /* If this is a safe waiting position we're done searching for it */
00432             if (IsSafeWaitingPosition(v, t, td, true, _settings_game.pf.forbid_90_deg)) break;
00433           }
00434           if (td == INVALID_TRACKDIR ||
00435               !IsSafeWaitingPosition(v, t, td, true, _settings_game.pf.forbid_90_deg) ||
00436               !IsWaitingPositionFree(v, t, td, _settings_game.pf.forbid_90_deg)) {
00437             extra_cost += Yapf().PfGetSettings().rail_lastred_exit_penalty;
00438           }
00439         }
00440         /* Waypoint is also a good reason to finish. */
00441         end_segment_reason |= ESRB_WAYPOINT;
00442 
00443       } else if (tf->m_is_station) {
00444         /* Station penalties. */
00445         uint platform_length = tf->m_tiles_skipped + 1;
00446         /* We don't know yet if the station is our target or not. Act like
00447          * if it is pass-through station (not our destination). */
00448         segment_cost += Yapf().PfGetSettings().rail_station_penalty * platform_length;
00449         /* We will end in this pass (station is possible target) */
00450         end_segment_reason |= ESRB_STATION;
00451 
00452       } else if (TrackFollower::DoTrackMasking() && cur.tile_type == MP_RAILWAY) {
00453         /* Searching for a safe tile? */
00454         if (HasSignalOnTrackdir(cur.tile, cur.td) && !IsPbsSignal(GetSignalType(cur.tile, TrackdirToTrack(cur.td)))) {
00455           end_segment_reason |= ESRB_SAFE_TILE;
00456         }
00457       }
00458 
00459       /* Apply min/max speed penalties only when inside the look-ahead radius. Otherwise
00460        * it would cause desync in MP. */
00461       if (n.m_num_signals_passed < m_sig_look_ahead_costs.Size())
00462       {
00463         int min_speed = 0;
00464         int max_speed = tf->GetSpeedLimit(&min_speed);
00465         if (max_speed < v->max_speed) {
00466           extra_cost += YAPF_TILE_LENGTH * (v->max_speed - max_speed) * (4 + tf->m_tiles_skipped) / v->max_speed;
00467         }
00468         if (min_speed > v->max_speed) {
00469           extra_cost += YAPF_TILE_LENGTH * (min_speed - v->max_speed);
00470         }
00471       }
00472 
00473       /* Finish if we already exceeded the maximum path cost (i.e. when
00474        * searching for the nearest depot). */
00475       if (m_max_cost > 0 && (parent_cost + segment_entry_cost + segment_cost) > m_max_cost) {
00476         end_segment_reason |= ESRB_PATH_TOO_LONG;
00477       }
00478 
00479       /* Move to the next tile/trackdir. */
00480       tf = &tf_local;
00481       tf_local.Init(v, Yapf().GetCompatibleRailTypes(), &Yapf().m_perf_ts_cost);
00482 
00483       if (!tf_local.Follow(cur.tile, cur.td)) {
00484         assert(tf_local.m_err != TrackFollower::EC_NONE);
00485         /* Can't move to the next tile (EOL?). */
00486         if (tf_local.m_err == TrackFollower::EC_RAIL_TYPE) {
00487           end_segment_reason |= ESRB_RAIL_TYPE;
00488         } else {
00489           end_segment_reason |= ESRB_DEAD_END;
00490         }
00491 
00492         if (TrackFollower::DoTrackMasking() && !HasOnewaySignalBlockingTrackdir(cur.tile, cur.td)) {
00493           end_segment_reason |= ESRB_SAFE_TILE;
00494         }
00495         break;
00496       }
00497 
00498       /* Check if the next tile is not a choice. */
00499       if (KillFirstBit(tf_local.m_new_td_bits) != TRACKDIR_BIT_NONE) {
00500         /* More than one segment will follow. Close this one. */
00501         end_segment_reason |= ESRB_CHOICE_FOLLOWS;
00502         break;
00503       }
00504 
00505       /* Gather the next tile/trackdir/tile_type/rail_type. */
00506       TILE next(tf_local.m_new_tile, (Trackdir)FindFirstBit2x64(tf_local.m_new_td_bits));
00507 
00508       if (TrackFollower::DoTrackMasking() && HasPbsSignalOnTrackdir(next.tile, next.td)) {
00509         /* Possible safe tile. */
00510         end_segment_reason |= ESRB_SAFE_TILE;
00511       }
00512 
00513       /* Check the next tile for the rail type. */
00514       if (next.rail_type != cur.rail_type) {
00515         /* Segment must consist from the same rail_type tiles. */
00516         end_segment_reason |= ESRB_RAIL_TYPE;
00517         break;
00518       }
00519 
00520       /* Avoid infinite looping. */
00521       if (next.tile == n.m_key.m_tile && next.td == n.m_key.m_td) {
00522         end_segment_reason |= ESRB_INFINITE_LOOP;
00523         break;
00524       }
00525 
00526       if (segment_cost > s_max_segment_cost) {
00527         /* Potentially in the infinite loop (or only very long segment?). We should
00528          * not force it to finish prematurely unless we are on a regular tile. */
00529         if (IsTileType(tf->m_new_tile, MP_RAILWAY)) {
00530           end_segment_reason |= ESRB_SEGMENT_TOO_LONG;
00531           break;
00532         }
00533       }
00534 
00535       /* Any other reason bit set? */
00536       if (end_segment_reason != ESRB_NONE) {
00537         break;
00538       }
00539 
00540       /* For the next loop set new prev and cur tile info. */
00541       prev = cur;
00542       cur = next;
00543 
00544     } // for (;;)
00545 
00546     bool target_seen = false;
00547     if ((end_segment_reason & ESRB_POSSIBLE_TARGET) != ESRB_NONE) {
00548       /* Depot, station or waypoint. */
00549       if (Yapf().PfDetectDestination(cur.tile, cur.td)) {
00550         /* Destination found. */
00551         target_seen = true;
00552       }
00553     }
00554 
00555     /* Update the segment if needed. */
00556     if (!is_cached_segment) {
00557       /* Write back the segment information so it can be reused the next time. */
00558       segment.m_cost = segment_cost;
00559       segment.m_end_segment_reason = end_segment_reason & ESRB_CACHED_MASK;
00560       /* Save end of segment back to the node. */
00561       n.SetLastTileTrackdir(cur.tile, cur.td);
00562     }
00563 
00564     /* Do we have an excuse why not to continue pathfinding in this direction? */
00565     if (!target_seen && (end_segment_reason & ESRB_ABORT_PF_MASK) != ESRB_NONE) {
00566       /* Reason to not continue. Stop this PF branch. */
00567       return false;
00568     }
00569 
00570     /* Special costs for the case we have reached our target. */
00571     if (target_seen) {
00572       n.flags_u.flags_s.m_targed_seen = true;
00573       /* Last-red and last-red-exit penalties. */
00574       if (n.flags_u.flags_s.m_last_signal_was_red) {
00575         if (n.m_last_red_signal_type == SIGTYPE_EXIT) {
00576           /* last signal was red pre-signal-exit */
00577           extra_cost += Yapf().PfGetSettings().rail_lastred_exit_penalty;
00578         } else {
00579           /* last signal was red, but not exit */
00580           extra_cost += Yapf().PfGetSettings().rail_lastred_penalty;
00581         }
00582       }
00583 
00584       /* Station platform-length penalty. */
00585       if ((end_segment_reason & ESRB_STATION) != ESRB_NONE) {
00586         const BaseStation *st = BaseStation::GetByTile(n.GetLastTile());
00587         assert(st != NULL);
00588         uint platform_length = st->GetPlatformLength(n.GetLastTile(), ReverseDiagDir(TrackdirToExitdir(n.GetLastTrackdir())));
00589         /* Reduce the extra cost caused by passing-station penalty (each station receives it in the segment cost). */
00590         extra_cost -= Yapf().PfGetSettings().rail_station_penalty * platform_length;
00591         /* Add penalty for the inappropriate platform length. */
00592         extra_cost += PlatformLengthPenalty(platform_length);
00593       }
00594     }
00595 
00596     /* total node cost */
00597     n.m_cost = parent_cost + segment_entry_cost + segment_cost + extra_cost;
00598 
00599     return true;
00600   }
00601 
00602   FORCEINLINE bool CanUseGlobalCache(Node& n) const
00603   {
00604     return !m_disable_cache
00605       && (n.m_parent != NULL)
00606       && (n.m_parent->m_num_signals_passed >= m_sig_look_ahead_costs.Size());
00607   }
00608 
00609   FORCEINLINE void ConnectNodeToCachedData(Node& n, CachedData& ci)
00610   {
00611     n.m_segment = &ci;
00612     if (n.m_segment->m_cost < 0) {
00613       n.m_segment->m_last_tile = n.m_key.m_tile;
00614       n.m_segment->m_last_td = n.m_key.m_td;
00615     }
00616   }
00617 
00618   void DisableCache(bool disable)
00619   {
00620     m_disable_cache = disable;
00621   }
00622 };
00623 
00624 #endif /* YAPF_COSTRAIL_HPP */

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