train_cmd.cpp

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00001 /* $Id: train_cmd.cpp 22152 2011-02-26 20:13:14Z 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 "gui.h"
00014 #include "articulated_vehicles.h"
00015 #include "command_func.h"
00016 #include "pathfinder/npf/npf_func.h"
00017 #include "pathfinder/yapf/yapf.hpp"
00018 #include "news_func.h"
00019 #include "company_func.h"
00020 #include "vehicle_gui.h"
00021 #include "newgrf_sound.h"
00022 #include "newgrf_text.h"
00023 #include "group.h"
00024 #include "strings_func.h"
00025 #include "viewport_func.h"
00026 #include "window_func.h"
00027 #include "vehicle_func.h"
00028 #include "sound_func.h"
00029 #include "ai/ai.hpp"
00030 #include "newgrf_station.h"
00031 #include "effectvehicle_func.h"
00032 #include "gamelog.h"
00033 #include "network/network.h"
00034 #include "spritecache.h"
00035 #include "core/random_func.hpp"
00036 #include "company_base.h"
00037 #include "newgrf.h"
00038 #include "order_backup.h"
00039 
00040 #include "table/strings.h"
00041 #include "table/train_cmd.h"
00042 
00043 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00044 static bool TrainCheckIfLineEnds(Train *v);
00045 static void TrainController(Train *v, Vehicle *nomove);
00046 static TileIndex TrainApproachingCrossingTile(const Train *v);
00047 static void CheckIfTrainNeedsService(Train *v);
00048 static void CheckNextTrainTile(Train *v);
00049 
00050 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00051 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00052 
00053 
00061 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00062 {
00063   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00064 
00065   DiagDirection diagdir = DirToDiagDir(direction);
00066 
00067   /* Determine the diagonal direction in which we will exit this tile */
00068   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00069     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00070   }
00071 
00072   return diagdir;
00073 }
00074 
00075 
00081 byte FreightWagonMult(CargoID cargo)
00082 {
00083   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00084   return _settings_game.vehicle.freight_trains;
00085 }
00086 
00092 static void RailVehicleLengthChanged(const Train *u)
00093 {
00094   /* show a warning once for each engine in whole game and once for each GRF after each game load */
00095   const Engine *engine = Engine::Get(u->engine_type);
00096   uint32 grfid = engine->grf_prop.grffile->grfid;
00097   GRFConfig *grfconfig = GetGRFConfig(grfid);
00098   if (GamelogGRFBugReverse(grfid, engine->grf_prop.local_id) || !HasBit(grfconfig->grf_bugs, GBUG_VEH_LENGTH)) {
00099     ShowNewGrfVehicleError(u->engine_type, STR_NEWGRF_BROKEN, STR_NEWGRF_BROKEN_VEHICLE_LENGTH, GBUG_VEH_LENGTH, true);
00100   }
00101 }
00102 
00104 void CheckTrainsLengths()
00105 {
00106   const Train *v;
00107   bool first = true;
00108 
00109   FOR_ALL_TRAINS(v) {
00110     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00111       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00112         if (u->track != TRACK_BIT_DEPOT) {
00113           if ((w->track != TRACK_BIT_DEPOT &&
00114               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->gcache.cached_veh_length) ||
00115               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00116             SetDParam(0, v->index);
00117             SetDParam(1, v->owner);
00118             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00119 
00120             if (!_networking && first) {
00121               first = false;
00122               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00123             }
00124             /* Break so we warn only once for each train. */
00125             break;
00126           }
00127         }
00128       }
00129     }
00130   }
00131 }
00132 
00137 void Train::RailtypeChanged()
00138 {
00139   for (Train *u = this; u != NULL; u = u->Next()) {
00140     /* The wagon-is-powered-state should not change, so the weight does not change. */
00141     u->UpdateVisualEffect(false);
00142   }
00143   this->PowerChanged();
00144   if (this->IsFrontEngine()) this->UpdateAcceleration();
00145 }
00146 
00153 void Train::ConsistChanged(bool same_length)
00154 {
00155   uint16 max_speed = UINT16_MAX;
00156 
00157   assert(this->IsFrontEngine() || this->IsFreeWagon());
00158 
00159   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00160   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00161   this->gcache.cached_total_length = 0;
00162   this->compatible_railtypes = RAILTYPES_NONE;
00163 
00164   bool train_can_tilt = true;
00165 
00166   for (Train *u = this; u != NULL; u = u->Next()) {
00167     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00168 
00169     /* Check the this->first cache. */
00170     assert(u->First() == this);
00171 
00172     /* update the 'first engine' */
00173     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00174     u->railtype = rvi_u->railtype;
00175 
00176     if (u->IsEngine()) first_engine = u->engine_type;
00177 
00178     /* Set user defined data to its default value */
00179     u->tcache.user_def_data = rvi_u->user_def_data;
00180     this->InvalidateNewGRFCache();
00181     u->InvalidateNewGRFCache();
00182   }
00183 
00184   for (Train *u = this; u != NULL; u = u->Next()) {
00185     /* Update user defined data (must be done before other properties) */
00186     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00187     this->InvalidateNewGRFCache();
00188     u->InvalidateNewGRFCache();
00189   }
00190 
00191   for (Train *u = this; u != NULL; u = u->Next()) {
00192     const Engine *e_u = Engine::Get(u->engine_type);
00193     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00194 
00195     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00196 
00197     /* Cache wagon override sprite group. NULL is returned if there is none */
00198     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00199 
00200     /* Reset colour map */
00201     u->colourmap = PAL_NONE;
00202 
00203     /* Update powered-wagon-status and visual effect */
00204     u->UpdateVisualEffect(true);
00205 
00206     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00207         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00208       /* wagon is powered */
00209       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00210     } else {
00211       ClrBit(u->flags, VRF_POWEREDWAGON);
00212     }
00213 
00214     if (!u->IsArticulatedPart()) {
00215       /* Do not count powered wagons for the compatible railtypes, as wagons always
00216          have railtype normal */
00217       if (rvi_u->power > 0) {
00218         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00219       }
00220 
00221       /* Some electric engines can be allowed to run on normal rail. It happens to all
00222        * existing electric engines when elrails are disabled and then re-enabled */
00223       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00224         u->railtype = RAILTYPE_RAIL;
00225         u->compatible_railtypes |= RAILTYPES_RAIL;
00226       }
00227 
00228       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00229       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00230         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00231         if (speed != 0) max_speed = min(speed, max_speed);
00232       }
00233     }
00234 
00235     u->cargo_cap = GetVehicleCapacity(u);
00236 
00237     /* check the vehicle length (callback) */
00238     uint16 veh_len = CALLBACK_FAILED;
00239     if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00240       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00241     }
00242     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00243     veh_len = 8 - Clamp(veh_len, 0, 7);
00244 
00245     /* verify length hasn't changed */
00246     if (same_length && veh_len != u->gcache.cached_veh_length) RailVehicleLengthChanged(u);
00247 
00248     /* update vehicle length? */
00249     if (!same_length) u->gcache.cached_veh_length = veh_len;
00250 
00251     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00252     this->InvalidateNewGRFCache();
00253     u->InvalidateNewGRFCache();
00254   }
00255 
00256   /* store consist weight/max speed in cache */
00257   this->vcache.cached_max_speed = max_speed;
00258   this->tcache.cached_tilt = train_can_tilt;
00259   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00260 
00261   /* recalculate cached weights and power too (we do this *after* the rest, so it is known which wagons are powered and need extra weight added) */
00262   this->CargoChanged();
00263 
00264   if (this->IsFrontEngine()) {
00265     this->UpdateAcceleration();
00266     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00267     InvalidateWindowData(WC_VEHICLE_REFIT, this->index); // Important, do not invalidate immediately. The refit window tests commands.
00268   }
00269 }
00270 
00281 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00282 {
00283   const Station *st = Station::Get(station_id);
00284   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00285   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00286 
00287   /* Default to the middle of the station for stations stops that are not in
00288    * the order list like intermediate stations when non-stop is disabled */
00289   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00290   if (v->gcache.cached_total_length >= *station_length) {
00291     /* The train is longer than the station, make it stop at the far end of the platform */
00292     osl = OSL_PLATFORM_FAR_END;
00293   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00294     osl = v->current_order.GetStopLocation();
00295   }
00296 
00297   /* The stop location of the FRONT! of the train */
00298   int stop;
00299   switch (osl) {
00300     default: NOT_REACHED();
00301 
00302     case OSL_PLATFORM_NEAR_END:
00303       stop = v->gcache.cached_total_length;
00304       break;
00305 
00306     case OSL_PLATFORM_MIDDLE:
00307       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00308       break;
00309 
00310     case OSL_PLATFORM_FAR_END:
00311       stop = *station_length;
00312       break;
00313   }
00314 
00315   /* Subtract half the front vehicle length of the train so we get the real
00316    * stop location of the train. */
00317   return stop - (v->gcache.cached_veh_length + 1) / 2;
00318 }
00319 
00320 
00325 int Train::GetCurveSpeedLimit() const
00326 {
00327   assert(this->First() == this);
00328 
00329   static const int absolute_max_speed = UINT16_MAX;
00330   int max_speed = absolute_max_speed;
00331 
00332   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00333 
00334   int curvecount[2] = {0, 0};
00335 
00336   /* first find the curve speed limit */
00337   int numcurve = 0;
00338   int sum = 0;
00339   int pos = 0;
00340   int lastpos = -1;
00341   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00342     Direction this_dir = u->direction;
00343     Direction next_dir = u->Next()->direction;
00344 
00345     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00346     if (dirdiff == DIRDIFF_SAME) continue;
00347 
00348     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00349     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00350     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00351       if (lastpos != -1) {
00352         numcurve++;
00353         sum += pos - lastpos;
00354         if (pos - lastpos == 1) {
00355           max_speed = 88;
00356         }
00357       }
00358       lastpos = pos;
00359     }
00360 
00361     /* if we have a 90 degree turn, fix the speed limit to 60 */
00362     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00363       max_speed = 61;
00364     }
00365   }
00366 
00367   if (numcurve > 0 && max_speed > 88) {
00368     if (curvecount[0] == 1 && curvecount[1] == 1) {
00369       max_speed = absolute_max_speed;
00370     } else {
00371       sum /= numcurve;
00372       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00373     }
00374   }
00375 
00376   if (max_speed != absolute_max_speed) {
00377     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00378     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00379     max_speed += (max_speed / 2) * rti->curve_speed;
00380 
00381     if (this->tcache.cached_tilt) {
00382       /* Apply max_speed bonus of 20% for a tilting train */
00383       max_speed += max_speed / 5;
00384     }
00385   }
00386 
00387   return max_speed;
00388 }
00389 
00394 int Train::GetCurrentMaxSpeed() const
00395 {
00396   int max_speed = this->tcache.cached_max_curve_speed;
00397   assert(max_speed == this->GetCurveSpeedLimit());
00398 
00399   if (IsRailStationTile(this->tile)) {
00400     StationID sid = GetStationIndex(this->tile);
00401     if (this->current_order.ShouldStopAtStation(this, sid)) {
00402       int station_ahead;
00403       int station_length;
00404       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00405 
00406       /* The distance to go is whatever is still ahead of the train minus the
00407        * distance from the train's stop location to the end of the platform */
00408       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00409 
00410       if (distance_to_go > 0) {
00411         int st_max_speed = 120;
00412 
00413         int delta_v = this->cur_speed / (distance_to_go + 1);
00414         if (max_speed > (this->cur_speed - delta_v)) {
00415           st_max_speed = this->cur_speed - (delta_v / 10);
00416         }
00417 
00418         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00419         max_speed = min(max_speed, st_max_speed);
00420       }
00421     }
00422   }
00423 
00424   for (const Train *u = this; u != NULL; u = u->Next()) {
00425     if (u->track == TRACK_BIT_DEPOT) {
00426       max_speed = min(max_speed, 61);
00427       break;
00428     }
00429   }
00430 
00431   return min(max_speed, this->gcache.cached_max_track_speed);
00432 }
00433 
00434 void Train::UpdateAcceleration()
00435 {
00436   assert(this->IsFrontEngine());
00437 
00438   uint power = this->gcache.cached_power;
00439   uint weight = this->gcache.cached_weight;
00440   assert(weight != 0);
00441   this->acceleration = Clamp(power / weight * 4, 1, 255);
00442 }
00443 
00449 int Train::GetDisplayImageWidth(Point *offset) const
00450 {
00451   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00452   int vehicle_pitch = 0;
00453 
00454   const Engine *e = Engine::Get(this->engine_type);
00455   if (e->grf_prop.grffile != NULL && is_custom_sprite(e->u.rail.image_index)) {
00456     reference_width = e->grf_prop.grffile->traininfo_vehicle_width;
00457     vehicle_pitch = e->grf_prop.grffile->traininfo_vehicle_pitch;
00458   }
00459 
00460   if (offset != NULL) {
00461     offset->x = reference_width / 2;
00462     offset->y = vehicle_pitch;
00463   }
00464   return this->gcache.cached_veh_length * reference_width / 8;
00465 }
00466 
00467 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00468 {
00469   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00470 }
00471 
00472 SpriteID Train::GetImage(Direction direction) const
00473 {
00474   uint8 spritenum = this->spritenum;
00475   SpriteID sprite;
00476 
00477   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00478 
00479   if (is_custom_sprite(spritenum)) {
00480     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)));
00481     if (sprite != 0) return sprite;
00482 
00483     spritenum = Engine::Get(this->engine_type)->original_image_index;
00484   }
00485 
00486   sprite = GetDefaultTrainSprite(spritenum, direction);
00487 
00488   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00489 
00490   return sprite;
00491 }
00492 
00493 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y)
00494 {
00495   const Engine *e = Engine::Get(engine);
00496   Direction dir = rear_head ? DIR_E : DIR_W;
00497   uint8 spritenum = e->u.rail.image_index;
00498 
00499   if (is_custom_sprite(spritenum)) {
00500     SpriteID sprite = GetCustomVehicleIcon(engine, dir);
00501     if (sprite != 0) {
00502       if (e->grf_prop.grffile != NULL) {
00503         y += e->grf_prop.grffile->traininfo_vehicle_pitch;
00504       }
00505       return sprite;
00506     }
00507 
00508     spritenum = Engine::Get(engine)->original_image_index;
00509   }
00510 
00511   if (rear_head) spritenum++;
00512 
00513   return GetDefaultTrainSprite(spritenum, DIR_W);
00514 }
00515 
00516 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal)
00517 {
00518   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00519     int yf = y;
00520     int yr = y;
00521 
00522     SpriteID spritef = GetRailIcon(engine, false, yf);
00523     SpriteID spriter = GetRailIcon(engine, true, yr);
00524     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00525     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00526 
00527     preferred_x = Clamp(preferred_x, left - real_spritef->x_offs + 14, right - real_spriter->width - real_spriter->x_offs - 15);
00528 
00529     DrawSprite(spritef, pal, preferred_x - 14, yf);
00530     DrawSprite(spriter, pal, preferred_x + 15, yr);
00531   } else {
00532     SpriteID sprite = GetRailIcon(engine, false, y);
00533     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00534     preferred_x = Clamp(preferred_x, left - real_sprite->x_offs, right - real_sprite->width - real_sprite->x_offs);
00535     DrawSprite(sprite, pal, preferred_x, y);
00536   }
00537 }
00538 
00547 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00548 {
00549   const RailVehicleInfo *rvi = &e->u.rail;
00550 
00551   /* Check that the wagon can drive on the track in question */
00552   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00553 
00554   if (flags & DC_EXEC) {
00555     Train *v = new Train();
00556     *ret = v;
00557     v->spritenum = rvi->image_index;
00558 
00559     v->engine_type = e->index;
00560     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00561 
00562     DiagDirection dir = GetRailDepotDirection(tile);
00563 
00564     v->direction = DiagDirToDir(dir);
00565     v->tile = tile;
00566 
00567     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00568     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00569 
00570     v->x_pos = x;
00571     v->y_pos = y;
00572     v->z_pos = GetSlopeZ(x, y);
00573     v->owner = _current_company;
00574     v->track = TRACK_BIT_DEPOT;
00575     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00576 
00577     v->SetWagon();
00578 
00579     v->SetFreeWagon();
00580     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00581 
00582     v->cargo_type = e->GetDefaultCargoType();
00583     v->cargo_cap = rvi->capacity;
00584 
00585     v->railtype = rvi->railtype;
00586 
00587     v->build_year = _cur_year;
00588     v->cur_image = SPR_IMG_QUERY;
00589     v->random_bits = VehicleRandomBits();
00590 
00591     v->group_id = DEFAULT_GROUP;
00592 
00593     AddArticulatedParts(v);
00594 
00595     _new_vehicle_id = v->index;
00596 
00597     VehicleMove(v, false);
00598     v->First()->ConsistChanged(false);
00599     UpdateTrainGroupID(v->First());
00600 
00601     CheckConsistencyOfArticulatedVehicle(v);
00602 
00603     /* Try to connect the vehicle to one of free chains of wagons. */
00604     Train *w;
00605     FOR_ALL_TRAINS(w) {
00606       if (w->tile == tile &&              
00607           w->IsFreeWagon() &&             
00608           w->engine_type == e->index &&   
00609           w->First() != v &&              
00610           !(w->vehstatus & VS_CRASHED)) { 
00611         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00612         break;
00613       }
00614     }
00615   }
00616 
00617   return CommandCost();
00618 }
00619 
00621 static void NormalizeTrainVehInDepot(const Train *u)
00622 {
00623   const Train *v;
00624   FOR_ALL_TRAINS(v) {
00625     if (v->IsFreeWagon() && v->tile == u->tile &&
00626         v->track == TRACK_BIT_DEPOT) {
00627       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00628           CMD_MOVE_RAIL_VEHICLE).Failed())
00629         break;
00630     }
00631   }
00632 }
00633 
00634 static void AddRearEngineToMultiheadedTrain(Train *v)
00635 {
00636   Train *u = new Train();
00637   v->value >>= 1;
00638   u->value = v->value;
00639   u->direction = v->direction;
00640   u->owner = v->owner;
00641   u->tile = v->tile;
00642   u->x_pos = v->x_pos;
00643   u->y_pos = v->y_pos;
00644   u->z_pos = v->z_pos;
00645   u->track = TRACK_BIT_DEPOT;
00646   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00647   u->spritenum = v->spritenum + 1;
00648   u->cargo_type = v->cargo_type;
00649   u->cargo_subtype = v->cargo_subtype;
00650   u->cargo_cap = v->cargo_cap;
00651   u->railtype = v->railtype;
00652   u->engine_type = v->engine_type;
00653   u->build_year = v->build_year;
00654   u->cur_image = SPR_IMG_QUERY;
00655   u->random_bits = VehicleRandomBits();
00656   v->SetMultiheaded();
00657   u->SetMultiheaded();
00658   v->SetNext(u);
00659   VehicleMove(u, false);
00660 
00661   /* Now we need to link the front and rear engines together */
00662   v->other_multiheaded_part = u;
00663   u->other_multiheaded_part = v;
00664 }
00665 
00675 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00676 {
00677   const RailVehicleInfo *rvi = &e->u.rail;
00678 
00679   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00680 
00681   /* Check if depot and new engine uses the same kind of tracks *
00682    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00683   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00684 
00685   if (flags & DC_EXEC) {
00686     DiagDirection dir = GetRailDepotDirection(tile);
00687     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00688     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00689 
00690     Train *v = new Train();
00691     *ret = v;
00692     v->direction = DiagDirToDir(dir);
00693     v->tile = tile;
00694     v->owner = _current_company;
00695     v->x_pos = x;
00696     v->y_pos = y;
00697     v->z_pos = GetSlopeZ(x, y);
00698     v->track = TRACK_BIT_DEPOT;
00699     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00700     v->spritenum = rvi->image_index;
00701     v->cargo_type = e->GetDefaultCargoType();
00702     v->cargo_cap = rvi->capacity;
00703     v->last_station_visited = INVALID_STATION;
00704 
00705     v->engine_type = e->index;
00706     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00707 
00708     v->reliability = e->reliability;
00709     v->reliability_spd_dec = e->reliability_spd_dec;
00710     v->max_age = e->GetLifeLengthInDays();
00711 
00712     v->railtype = rvi->railtype;
00713     _new_vehicle_id = v->index;
00714 
00715     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00716     v->date_of_last_service = _date;
00717     v->build_year = _cur_year;
00718     v->cur_image = SPR_IMG_QUERY;
00719     v->random_bits = VehicleRandomBits();
00720 
00721     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00722 
00723     v->group_id = DEFAULT_GROUP;
00724 
00725     v->SetFrontEngine();
00726     v->SetEngine();
00727 
00728     VehicleMove(v, false);
00729 
00730     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00731       AddRearEngineToMultiheadedTrain(v);
00732     } else {
00733       AddArticulatedParts(v);
00734     }
00735 
00736     v->ConsistChanged(false);
00737     UpdateTrainGroupID(v);
00738 
00739     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00740       NormalizeTrainVehInDepot(v);
00741     }
00742 
00743     CheckConsistencyOfArticulatedVehicle(v);
00744   }
00745 
00746   return CommandCost();
00747 }
00748 
00749 
00750 bool Train::IsInDepot() const
00751 {
00752   /* Is the front engine stationary in the depot? */
00753   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00754 
00755   /* Check whether the rest is also already trying to enter the depot. */
00756   for (const Train *v = this; v != NULL; v = v->Next()) {
00757     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00758   }
00759 
00760   return true;
00761 }
00762 
00763 bool Train::IsStoppedInDepot() const
00764 {
00765   /* Are we stopped? Of course wagons don't really care... */
00766   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00767   return this->IsInDepot();
00768 }
00769 
00770 static Train *FindGoodVehiclePos(const Train *src)
00771 {
00772   EngineID eng = src->engine_type;
00773   TileIndex tile = src->tile;
00774 
00775   Train *dst;
00776   FOR_ALL_TRAINS(dst) {
00777     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00778       /* check so all vehicles in the line have the same engine. */
00779       Train *t = dst;
00780       while (t->engine_type == eng) {
00781         t = t->Next();
00782         if (t == NULL) return dst;
00783       }
00784     }
00785   }
00786 
00787   return NULL;
00788 }
00789 
00791 typedef SmallVector<Train *, 16> TrainList;
00792 
00798 static void MakeTrainBackup(TrainList &list, Train *t)
00799 {
00800   for (; t != NULL; t = t->Next()) *list.Append() = t;
00801 }
00802 
00807 static void RestoreTrainBackup(TrainList &list)
00808 {
00809   /* No train, nothing to do. */
00810   if (list.Length() == 0) return;
00811 
00812   Train *prev = NULL;
00813   /* Iterate over the list and rebuild it. */
00814   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00815     Train *t = *iter;
00816     if (prev != NULL) {
00817       prev->SetNext(t);
00818     } else if (t->Previous() != NULL) {
00819       /* Make sure the head of the train is always the first in the chain. */
00820       t->Previous()->SetNext(NULL);
00821     }
00822     prev = t;
00823   }
00824 }
00825 
00831 static void RemoveFromConsist(Train *part, bool chain = false)
00832 {
00833   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00834 
00835   /* Unlink at the front, but make it point to the next
00836    * vehicle after the to be remove part. */
00837   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00838 
00839   /* Unlink at the back */
00840   tail->SetNext(NULL);
00841 }
00842 
00848 static void InsertInConsist(Train *dst, Train *chain)
00849 {
00850   /* We do not want to add something in the middle of an articulated part. */
00851   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00852 
00853   chain->Last()->SetNext(dst->Next());
00854   dst->SetNext(chain);
00855 }
00856 
00862 static void NormaliseDualHeads(Train *t)
00863 {
00864   for (; t != NULL; t = t->GetNextVehicle()) {
00865     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00866 
00867     /* Make sure that there are no free cars before next engine */
00868     Train *u;
00869     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00870 
00871     if (u == t->other_multiheaded_part) continue;
00872 
00873     /* Remove the part from the 'wrong' train */
00874     RemoveFromConsist(t->other_multiheaded_part);
00875     /* And add it to the 'right' train */
00876     InsertInConsist(u, t->other_multiheaded_part);
00877   }
00878 }
00879 
00884 static void NormaliseSubtypes(Train *chain)
00885 {
00886   /* Nothing to do */
00887   if (chain == NULL) return;
00888 
00889   /* We must be the first in the chain. */
00890   assert(chain->Previous() == NULL);
00891 
00892   /* Set the appropriate bits for the first in the chain. */
00893   if (chain->IsWagon()) {
00894     chain->SetFreeWagon();
00895   } else {
00896     assert(chain->IsEngine());
00897     chain->SetFrontEngine();
00898   }
00899 
00900   /* Now clear the bits for the rest of the chain */
00901   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00902     t->ClearFreeWagon();
00903     t->ClearFrontEngine();
00904   }
00905 }
00906 
00916 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00917 {
00918   /* Just add 'new' engines and subtract the original ones.
00919    * If that's less than or equal to 0 we can be sure we did
00920    * not add any engines (read: trains) along the way. */
00921   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00922       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00923       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00924       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00925     return CommandCost();
00926   }
00927 
00928   /* Get a free unit number and check whether it's within the bounds.
00929    * There will always be a maximum of one new train. */
00930   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00931 
00932   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00933 }
00934 
00940 static CommandCost CheckTrainAttachment(Train *t)
00941 {
00942   /* No multi-part train, no need to check. */
00943   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00944 
00945   /* The maximum length for a train. For each part we decrease this by one
00946    * and if the result is negative the train is simply too long. */
00947   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00948 
00949   Train *head = t;
00950   Train *prev = t;
00951 
00952   /* Break the prev -> t link so it always holds within the loop. */
00953   t = t->Next();
00954   prev->SetNext(NULL);
00955 
00956   /* Make sure the cache is cleared. */
00957   head->InvalidateNewGRFCache();
00958 
00959   while (t != NULL) {
00960     allowed_len -= t->gcache.cached_veh_length;
00961 
00962     Train *next = t->Next();
00963 
00964     /* Unlink the to-be-added piece; it is already unlinked from the previous
00965      * part due to the fact that the prev -> t link is broken. */
00966     t->SetNext(NULL);
00967 
00968     /* Don't check callback for articulated or rear dual headed parts */
00969     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00970       /* Back up and clear the first_engine data to avoid using wagon override group */
00971       EngineID first_engine = t->gcache.first_engine;
00972       t->gcache.first_engine = INVALID_ENGINE;
00973 
00974       /* We don't want the cache to interfere. head's cache is cleared before
00975        * the loop and after each callback does not need to be cleared here. */
00976       t->InvalidateNewGRFCache();
00977 
00978       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00979 
00980       /* Restore original first_engine data */
00981       t->gcache.first_engine = first_engine;
00982 
00983       /* We do not want to remember any cached variables from the test run */
00984       t->InvalidateNewGRFCache();
00985       head->InvalidateNewGRFCache();
00986 
00987       if (callback != CALLBACK_FAILED) {
00988         /* A failing callback means everything is okay */
00989         StringID error = STR_NULL;
00990 
00991         if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00992         if (callback  < 0xFD) error = GetGRFStringID(GetEngineGRFID(head->engine_type), 0xD000 + callback);
00993 
00994         if (error != STR_NULL) return_cmd_error(error);
00995       }
00996     }
00997 
00998     /* And link it to the new part. */
00999     prev->SetNext(t);
01000     prev = t;
01001     t = next;
01002   }
01003 
01004   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01005   return CommandCost();
01006 }
01007 
01018 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01019 {
01020   /* Check whether we may actually construct the trains. */
01021   CommandCost ret = CheckTrainAttachment(src);
01022   if (ret.Failed()) return ret;
01023   ret = CheckTrainAttachment(dst);
01024   if (ret.Failed()) return ret;
01025 
01026   /* Check whether we need to build a new train. */
01027   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01028 }
01029 
01038 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01039 {
01040   /* First determine the front of the two resulting trains */
01041   if (*src_head == *dst_head) {
01042     /* If we aren't moving part(s) to a new train, we are just moving the
01043      * front back and there is not destination head. */
01044     *dst_head = NULL;
01045   } else if (*dst_head == NULL) {
01046     /* If we are moving to a new train the head of the move train would become
01047      * the head of the new vehicle. */
01048     *dst_head = src;
01049   }
01050 
01051   if (src == *src_head) {
01052     /* If we are moving the front of a train then we are, in effect, creating
01053      * a new head for the train. Point to that. Unless we are moving the whole
01054      * train in which case there is not 'source' train anymore.
01055      * In case we are a multiheaded part we want the complete thing to come
01056      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01057      * that is followed by a rear multihead we do not want to include that. */
01058     *src_head = move_chain ? NULL :
01059         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01060   }
01061 
01062   /* Now it's just simply removing the part that we are going to move from the
01063    * source train and *if* the destination is a not a new train add the chain
01064    * at the destination location. */
01065   RemoveFromConsist(src, move_chain);
01066   if (*dst_head != src) InsertInConsist(dst, src);
01067 
01068   /* Now normalise the dual heads, that is move the dual heads around in such
01069    * a way that the head and rear of a dual head are in the same train */
01070   NormaliseDualHeads(*src_head);
01071   NormaliseDualHeads(*dst_head);
01072 }
01073 
01079 static void NormaliseTrainHead(Train *head)
01080 {
01081   /* Not much to do! */
01082   if (head == NULL) return;
01083 
01084   /* Tell the 'world' the train changed. */
01085   head->ConsistChanged(false);
01086   UpdateTrainGroupID(head);
01087 
01088   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01089   if (!head->IsFrontEngine()) return;
01090 
01091   /* Update the refit button and window */
01092   InvalidateWindowData(WC_VEHICLE_REFIT, head->index); // Important, do not invalidate immediately. The refit window tests commands.
01093   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, VVW_WIDGET_REFIT_VEH);
01094 
01095   /* If we don't have a unit number yet, set one. */
01096   if (head->unitnumber != 0) return;
01097   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01098 }
01099 
01112 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01113 {
01114   VehicleID s = GB(p1, 0, 20);
01115   VehicleID d = GB(p2, 0, 20);
01116   bool move_chain = HasBit(p1, 20);
01117 
01118   Train *src = Train::GetIfValid(s);
01119   if (src == NULL) return CMD_ERROR;
01120 
01121   CommandCost ret = CheckOwnership(src->owner);
01122   if (ret.Failed()) return ret;
01123 
01124   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01125   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01126 
01127   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01128   Train *dst;
01129   if (d == INVALID_VEHICLE) {
01130     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01131   } else {
01132     dst = Train::GetIfValid(d);
01133     if (dst == NULL) return CMD_ERROR;
01134 
01135     CommandCost ret = CheckOwnership(dst->owner);
01136     if (ret.Failed()) return ret;
01137 
01138     /* Do not allow appending to crashed vehicles, too */
01139     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01140   }
01141 
01142   /* if an articulated part is being handled, deal with its parent vehicle */
01143   src = src->GetFirstEnginePart();
01144   if (dst != NULL) {
01145     dst = dst->GetFirstEnginePart();
01146   }
01147 
01148   /* don't move the same vehicle.. */
01149   if (src == dst) return CommandCost();
01150 
01151   /* locate the head of the two chains */
01152   Train *src_head = src->First();
01153   Train *dst_head;
01154   if (dst != NULL) {
01155     dst_head = dst->First();
01156     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01157     /* Now deal with articulated part of destination wagon */
01158     dst = dst->GetLastEnginePart();
01159   } else {
01160     dst_head = NULL;
01161   }
01162 
01163   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01164 
01165   /* When moving all wagons, we can't have the same src_head and dst_head */
01166   if (move_chain && src_head == dst_head) return CommandCost();
01167 
01168   /* When moving a multiheaded part to be place after itself, bail out. */
01169   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01170 
01171   /* Check if all vehicles in the source train are stopped inside a depot. */
01172   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01173 
01174   /* Check if all vehicles in the destination train are stopped inside a depot. */
01175   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01176 
01177   /* First make a backup of the order of the trains. That way we can do
01178    * whatever we want with the order and later on easily revert. */
01179   TrainList original_src;
01180   TrainList original_dst;
01181 
01182   MakeTrainBackup(original_src, src_head);
01183   MakeTrainBackup(original_dst, dst_head);
01184 
01185   /* Also make backup of the original heads as ArrangeTrains can change them.
01186    * For the destination head we do not care if it is the same as the source
01187    * head because in that case it's just a copy. */
01188   Train *original_src_head = src_head;
01189   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01190 
01191   /* (Re)arrange the trains in the wanted arrangement. */
01192   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01193 
01194   if ((flags & DC_AUTOREPLACE) == 0) {
01195     /* If the autoreplace flag is set we do not need to test for the validity
01196      * because we are going to revert the train to its original state. As we
01197      * assume the original state was correct autoreplace can skip this. */
01198     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01199     if (ret.Failed()) {
01200       /* Restore the train we had. */
01201       RestoreTrainBackup(original_src);
01202       RestoreTrainBackup(original_dst);
01203       return ret;
01204     }
01205   }
01206 
01207   /* do it? */
01208   if (flags & DC_EXEC) {
01209     /* First normalise the sub types of the chains. */
01210     NormaliseSubtypes(src_head);
01211     NormaliseSubtypes(dst_head);
01212 
01213     /* There are 14 different cases:
01214      *  1) front engine gets moved to a new train, it stays a front engine.
01215      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01216      *     b) the 'next' part is an engine that becomes a front engine.
01217      *     c) there is no 'next' part, nothing else happens
01218      *  2) front engine gets moved to another train, it is not a front engine anymore
01219      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01220      *     b) the 'next' part is an engine that becomes a front engine.
01221      *     c) there is no 'next' part, nothing else happens
01222      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01223      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01224      *     b) the 'next' part is an engine that becomes a front engine.
01225      *  4) free wagon gets moved
01226      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01227      *     b) the 'next' part is an engine that becomes a front engine.
01228      *     c) there is no 'next' part, nothing else happens
01229      *  5) non front engine gets moved and becomes a new train, nothing else happens
01230      *  6) non front engine gets moved within a train / to another train, nothing hapens
01231      *  7) wagon gets moved, nothing happens
01232      */
01233     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01234       /* Cases #2 and #3: the front engine gets trashed. */
01235       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01236       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01237       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01238       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01239       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01240 
01241       /* We are going to be moved to a different train, and
01242        * we were the front engine of the original train. */
01243       if (dst_head != NULL && dst_head != src && (src_head == NULL || !src_head->IsFrontEngine())) {
01244         DecreaseGroupNumVehicle(src->group_id);
01245       }
01246 
01247       /* The front engine is going to be moved later in the
01248        * current train, and it will not be a train anymore. */
01249       if (dst_head == NULL && !src_head->IsFrontEngine()) {
01250         DecreaseGroupNumVehicle(src->group_id);
01251       }
01252 
01253       /* Delete orders, group stuff and the unit number as we're not the
01254        * front of any vehicle anymore. */
01255       DeleteVehicleOrders(src);
01256       RemoveVehicleFromGroup(src);
01257       src->unitnumber = 0;
01258     }
01259 
01260     /* We were a front engine and we are becoming one for a different train.
01261      * Increase the group counter accordingly. */
01262     if (original_src_head == src && dst_head == src) {
01263       IncreaseGroupNumVehicle(src->group_id);
01264     }
01265 
01266     /* We weren't a front engine but are becoming one. So
01267      * we should be put in the default group. */
01268     if (original_src_head != src && dst_head == src) {
01269       SetTrainGroupID(src, DEFAULT_GROUP);
01270     }
01271 
01272     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01273     NormaliseTrainHead(src_head);
01274     NormaliseTrainHead(dst_head);
01275 
01276     /* We are undoubtedly changing something in the depot and train list. */
01277     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01278     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01279   } else {
01280     /* We don't want to execute what we're just tried. */
01281     RestoreTrainBackup(original_src);
01282     RestoreTrainBackup(original_dst);
01283   }
01284 
01285   return CommandCost();
01286 }
01287 
01299 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01300 {
01301   /* Check if we deleted a vehicle window */
01302   Window *w = NULL;
01303 
01304   /* Sell a chain of vehicles or not? */
01305   bool sell_chain = HasBit(data, 0);
01306 
01307   Train *v = Train::From(t)->GetFirstEnginePart();
01308   Train *first = v->First();
01309 
01310   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01311 
01312   /* First make a backup of the order of the train. That way we can do
01313    * whatever we want with the order and later on easily revert. */
01314   TrainList original;
01315   MakeTrainBackup(original, first);
01316 
01317   /* We need to keep track of the new head and the head of what we're going to sell. */
01318   Train *new_head = first;
01319   Train *sell_head = NULL;
01320 
01321   /* Split the train in the wanted way. */
01322   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01323 
01324   /* We don't need to validate the second train; it's going to be sold. */
01325   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01326   if (ret.Failed()) {
01327     /* Restore the train we had. */
01328     RestoreTrainBackup(original);
01329     return ret;
01330   }
01331 
01332   CommandCost cost(EXPENSES_NEW_VEHICLES);
01333   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01334 
01335   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01336     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01337   }
01338 
01339   /* do it? */
01340   if (flags & DC_EXEC) {
01341     /* First normalise the sub types of the chain. */
01342     NormaliseSubtypes(new_head);
01343 
01344     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01345       /* We are selling the front engine. In this case we want to
01346        * 'give' the order, unit number and such to the new head. */
01347       new_head->orders.list = first->orders.list;
01348       new_head->AddToShared(first);
01349       DeleteVehicleOrders(first);
01350 
01351       /* Copy other important data from the front engine */
01352       new_head->CopyVehicleConfigAndStatistics(first);
01353       IncreaseGroupNumVehicle(new_head->group_id);
01354 
01355       /* If we deleted a window then open a new one for the 'new' train */
01356       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01357     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01358       OrderBackup::Backup(v, user);
01359     }
01360 
01361     /* We need to update the information about the train. */
01362     NormaliseTrainHead(new_head);
01363 
01364     /* We are undoubtedly changing something in the depot and train list. */
01365     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01366     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01367 
01368     /* Actually delete the sold 'goods' */
01369     delete sell_head;
01370   } else {
01371     /* We don't want to execute what we're just tried. */
01372     RestoreTrainBackup(original);
01373   }
01374 
01375   return cost;
01376 }
01377 
01378 void Train::UpdateDeltaXY(Direction direction)
01379 {
01380 #define MKIT(a, b, c, d) ((a & 0xFF) << 24) | ((b & 0xFF) << 16) | ((c & 0xFF) << 8) | ((d & 0xFF) << 0)
01381   static const uint32 _delta_xy_table[8] = {
01382     MKIT(3, 3, -1, -1),
01383     MKIT(3, 7, -1, -3),
01384     MKIT(3, 3, -1, -1),
01385     MKIT(7, 3, -3, -1),
01386     MKIT(3, 3, -1, -1),
01387     MKIT(3, 7, -1, -3),
01388     MKIT(3, 3, -1, -1),
01389     MKIT(7, 3, -3, -1),
01390   };
01391 #undef MKIT
01392 
01393   uint32 x = _delta_xy_table[direction];
01394   this->x_offs        = GB(x,  0, 8);
01395   this->y_offs        = GB(x,  8, 8);
01396   this->x_extent      = GB(x, 16, 8);
01397   this->y_extent      = GB(x, 24, 8);
01398   this->z_extent      = 6;
01399 }
01400 
01402 static void MarkTrainAsStuck(Train *v)
01403 {
01404   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01405     /* It is the first time the problem occurred, set the "train stuck" flag. */
01406     SetBit(v->flags, VRF_TRAIN_STUCK);
01407 
01408     v->wait_counter = 0;
01409 
01410     /* Stop train */
01411     v->cur_speed = 0;
01412     v->subspeed = 0;
01413     v->SetLastSpeed();
01414 
01415     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01416   }
01417 }
01418 
01419 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01420 {
01421   uint16 flag1 = *swap_flag1;
01422   uint16 flag2 = *swap_flag2;
01423 
01424   /* Clear the flags */
01425   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01426   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01427   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01428   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01429 
01430   /* Reverse the rail-flags (if needed) */
01431   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01432     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01433   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01434     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01435   }
01436   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01437     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01438   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01439     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01440   }
01441 }
01442 
01447 static void UpdateStatusAfterSwap(Train *v)
01448 {
01449   /* Reverse the direction. */
01450   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01451 
01452   /* Call the proper EnterTile function unless we are in a wormhole. */
01453   if (v->track != TRACK_BIT_WORMHOLE) {
01454     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01455   } else {
01456     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01457      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01458      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01459      * when we shouldn't have. Check if this is the case. */
01460     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01461     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01462       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01463       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01464         /* We have just left the wormhole, possibly set the
01465          * "goingdown" bit. UpdateInclination() can be used
01466          * because we are at the border of the tile. */
01467         v->UpdateInclination(true, true);
01468         return;
01469       }
01470     }
01471   }
01472 
01473   v->UpdateViewport(true, true);
01474 }
01475 
01476 static void ReverseTrainSwapVeh(Train *v, int l, int r)
01477 {
01478   Train *a, *b;
01479 
01480   /* locate vehicles to swap */
01481   for (a = v; l != 0; l--) a = a->Next();
01482   for (b = v; r != 0; r--) b = b->Next();
01483 
01484   if (a != b) {
01485     /* swap the hidden bits */
01486     {
01487       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01488       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01489       a->vehstatus = tmp;
01490     }
01491 
01492     Swap(a->track, b->track);
01493     Swap(a->direction, b->direction);
01494     Swap(a->x_pos, b->x_pos);
01495     Swap(a->y_pos, b->y_pos);
01496     Swap(a->tile,  b->tile);
01497     Swap(a->z_pos, b->z_pos);
01498 
01499     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01500 
01501     UpdateStatusAfterSwap(a);
01502     UpdateStatusAfterSwap(b);
01503   } else {
01504     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01505      * This is a little bit redundant way, a->gv_flags will
01506      * be (re)set twice, but it reduces code duplication */
01507     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01508     UpdateStatusAfterSwap(a);
01509   }
01510 
01511   /* Update power of the train in case tiles were different rail type. */
01512   v->RailtypeChanged();
01513 }
01514 
01515 
01521 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01522 {
01523   return (v->type == VEH_TRAIN) ? v : NULL;
01524 }
01525 
01526 
01533 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01534 {
01535   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01536 
01537   Train *t = Train::From(v);
01538   if (!t->IsFrontEngine()) return NULL;
01539 
01540   TileIndex tile = *(TileIndex *)data;
01541 
01542   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01543 
01544   return t;
01545 }
01546 
01547 
01554 static bool TrainApproachingCrossing(TileIndex tile)
01555 {
01556   assert(IsLevelCrossingTile(tile));
01557 
01558   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01559   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01560 
01561   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01562 
01563   dir = ReverseDiagDir(dir);
01564   tile_from = tile + TileOffsByDiagDir(dir);
01565 
01566   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01567 }
01568 
01569 
01576 void UpdateLevelCrossing(TileIndex tile, bool sound)
01577 {
01578   assert(IsLevelCrossingTile(tile));
01579 
01580   /* train on crossing || train approaching crossing || reserved */
01581   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01582 
01583   if (new_state != IsCrossingBarred(tile)) {
01584     if (new_state && sound) {
01585       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01586     }
01587     SetCrossingBarred(tile, new_state);
01588     MarkTileDirtyByTile(tile);
01589   }
01590 }
01591 
01592 
01598 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01599 {
01600   if (!IsCrossingBarred(tile)) {
01601     BarCrossing(tile);
01602     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01603     MarkTileDirtyByTile(tile);
01604   }
01605 }
01606 
01607 
01613 static void AdvanceWagonsBeforeSwap(Train *v)
01614 {
01615   Train *base = v;
01616   Train *first = base; // first vehicle to move
01617   Train *last = v->Last(); // last vehicle to move
01618   uint length = CountVehiclesInChain(v);
01619 
01620   while (length > 2) {
01621     last = last->Previous();
01622     first = first->Next();
01623 
01624     int differential = base->gcache.cached_veh_length - last->gcache.cached_veh_length;
01625 
01626     /* do not update images now
01627      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01628     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01629 
01630     base = first; // == base->Next()
01631     length -= 2;
01632   }
01633 }
01634 
01635 
01641 static void AdvanceWagonsAfterSwap(Train *v)
01642 {
01643   /* first of all, fix the situation when the train was entering a depot */
01644   Train *dep = v; // last vehicle in front of just left depot
01645   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01646     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01647   }
01648 
01649   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01650 
01651   if (leave != NULL) {
01652     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01653     int d = TicksToLeaveDepot(dep);
01654 
01655     if (d <= 0) {
01656       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01657       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01658       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01659     }
01660   } else {
01661     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01662   }
01663 
01664   Train *base = v;
01665   Train *first = base; // first vehicle to move
01666   Train *last = v->Last(); // last vehicle to move
01667   uint length = CountVehiclesInChain(v);
01668 
01669   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01670    * they have already correct spacing, so we have to make sure they are moved how they should */
01671   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01672 
01673   while (length > 2) {
01674     /* we reached vehicle (originally) in front of a depot, stop now
01675      * (we would move wagons that are already moved with new wagon length). */
01676     if (base == dep) break;
01677 
01678     /* the last wagon was that one leaving a depot, so do not move it anymore */
01679     if (last == dep) nomove = true;
01680 
01681     last = last->Previous();
01682     first = first->Next();
01683 
01684     int differential = last->gcache.cached_veh_length - base->gcache.cached_veh_length;
01685 
01686     /* do not update images now */
01687     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01688 
01689     base = first; // == base->Next()
01690     length -= 2;
01691   }
01692 }
01693 
01694 
01695 static void ReverseTrainDirection(Train *v)
01696 {
01697   if (IsRailDepotTile(v->tile)) {
01698     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01699   }
01700 
01701   /* Clear path reservation in front if train is not stuck. */
01702   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01703 
01704   /* Check if we were approaching a rail/road-crossing */
01705   TileIndex crossing = TrainApproachingCrossingTile(v);
01706 
01707   /* count number of vehicles */
01708   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01709 
01710   AdvanceWagonsBeforeSwap(v);
01711 
01712   /* swap start<>end, start+1<>end-1, ... */
01713   int l = 0;
01714   do {
01715     ReverseTrainSwapVeh(v, l++, r--);
01716   } while (l <= r);
01717 
01718   AdvanceWagonsAfterSwap(v);
01719 
01720   if (IsRailDepotTile(v->tile)) {
01721     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01722   }
01723 
01724   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01725 
01726   ClrBit(v->flags, VRF_REVERSING);
01727 
01728   /* recalculate cached data */
01729   v->ConsistChanged(true);
01730 
01731   /* update all images */
01732   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01733 
01734   /* update crossing we were approaching */
01735   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01736 
01737   /* maybe we are approaching crossing now, after reversal */
01738   crossing = TrainApproachingCrossingTile(v);
01739   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01740 
01741   /* If we are inside a depot after reversing, don't bother with path reserving. */
01742   if (v->track == TRACK_BIT_DEPOT) {
01743     /* Can't be stuck here as inside a depot is always a safe tile. */
01744     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01745     ClrBit(v->flags, VRF_TRAIN_STUCK);
01746     return;
01747   }
01748 
01749   /* TrainExitDir does not always produce the desired dir for depots and
01750    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01751   DiagDirection dir = TrainExitDir(v->direction, v->track);
01752   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01753 
01754   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01755     /* If we are currently on a tile with conventional signals, we can't treat the
01756      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01757     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01758       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01759       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01760 
01761     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01762     if (TryPathReserve(v, false, first_tile_okay)) {
01763       /* Do a look-ahead now in case our current tile was already a safe tile. */
01764       CheckNextTrainTile(v);
01765     } else if (v->current_order.GetType() != OT_LOADING) {
01766       /* Do not wait for a way out when we're still loading */
01767       MarkTrainAsStuck(v);
01768     }
01769   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01770     /* A train not inside a PBS block can't be stuck. */
01771     ClrBit(v->flags, VRF_TRAIN_STUCK);
01772     v->wait_counter = 0;
01773   }
01774 }
01775 
01785 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01786 {
01787   Train *v = Train::GetIfValid(p1);
01788   if (v == NULL) return CMD_ERROR;
01789 
01790   CommandCost ret = CheckOwnership(v->owner);
01791   if (ret.Failed()) return ret;
01792 
01793   if (p2 != 0) {
01794     /* turn a single unit around */
01795 
01796     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01797       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01798     }
01799     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01800 
01801     Train *front = v->First();
01802     /* make sure the vehicle is stopped in the depot */
01803     if (!front->IsStoppedInDepot()) {
01804       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01805     }
01806 
01807     if (flags & DC_EXEC) {
01808       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01809 
01810       front->ConsistChanged(false);
01811       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01812       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01813       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01814       SetWindowClassesDirty(WC_TRAINS_LIST);
01815     }
01816   } else {
01817     /* turn the whole train around */
01818     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01819 
01820     if (flags & DC_EXEC) {
01821       /* Properly leave the station if we are loading and won't be loading anymore */
01822       if (v->current_order.IsType(OT_LOADING)) {
01823         const Vehicle *last = v;
01824         while (last->Next() != NULL) last = last->Next();
01825 
01826         /* not a station || different station --> leave the station */
01827         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01828           v->LeaveStation();
01829         }
01830       }
01831 
01832       /* We cancel any 'skip signal at dangers' here */
01833       v->force_proceed = TFP_NONE;
01834       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01835 
01836       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01837         ToggleBit(v->flags, VRF_REVERSING);
01838       } else {
01839         v->cur_speed = 0;
01840         v->SetLastSpeed();
01841         HideFillingPercent(&v->fill_percent_te_id);
01842         ReverseTrainDirection(v);
01843       }
01844     }
01845   }
01846   return CommandCost();
01847 }
01848 
01858 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01859 {
01860   Train *t = Train::GetIfValid(p1);
01861   if (t == NULL) return CMD_ERROR;
01862 
01863   CommandCost ret = CheckOwnership(t->owner);
01864   if (ret.Failed()) return ret;
01865 
01866 
01867   if (flags & DC_EXEC) {
01868     /* If we are forced to proceed, cancel that order.
01869      * If we are marked stuck we would want to force the train
01870      * to proceed to the next signal. In the other cases we
01871      * would like to pass the signal at danger and run till the
01872      * next signal we encounter. */
01873     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01874     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01875   }
01876 
01877   return CommandCost();
01878 }
01879 
01884 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01885 {
01886   assert(!(v->vehstatus & VS_CRASHED));
01887 
01888   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01889 
01890   PBSTileInfo origin = FollowTrainReservation(v);
01891   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01892 
01893   switch (_settings_game.pf.pathfinder_for_trains) {
01894     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01895     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01896 
01897     default: NOT_REACHED();
01898   }
01899 }
01900 
01901 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01902 {
01903   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01904   if (tfdd.best_length == UINT_MAX) return false;
01905 
01906   if (location    != NULL) *location    = tfdd.tile;
01907   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01908   if (reverse     != NULL) *reverse     = tfdd.reverse;
01909 
01910   return true;
01911 }
01912 
01913 void Train::PlayLeaveStationSound() const
01914 {
01915   static const SoundFx sfx[] = {
01916     SND_04_TRAIN,
01917     SND_0A_TRAIN_HORN,
01918     SND_0A_TRAIN_HORN,
01919     SND_47_MAGLEV_2,
01920     SND_41_MAGLEV
01921   };
01922 
01923   if (PlayVehicleSound(this, VSE_START)) return;
01924 
01925   EngineID engtype = this->engine_type;
01926   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
01927 }
01928 
01930 static void CheckNextTrainTile(Train *v)
01931 {
01932   /* Don't do any look-ahead if path_backoff_interval is 255. */
01933   if (_settings_game.pf.path_backoff_interval == 255) return;
01934 
01935   /* Exit if we are inside a depot. */
01936   if (v->track == TRACK_BIT_DEPOT) return;
01937 
01938   switch (v->current_order.GetType()) {
01939     /* Exit if we reached our destination depot. */
01940     case OT_GOTO_DEPOT:
01941       if (v->tile == v->dest_tile) return;
01942       break;
01943 
01944     case OT_GOTO_WAYPOINT:
01945       /* If we reached our waypoint, make sure we see that. */
01946       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
01947       break;
01948 
01949     case OT_NOTHING:
01950     case OT_LEAVESTATION:
01951     case OT_LOADING:
01952       /* Exit if the current order doesn't have a destination, but the train has orders. */
01953       if (v->GetNumOrders() > 0) return;
01954       break;
01955 
01956     default:
01957       break;
01958   }
01959   /* Exit if we are on a station tile and are going to stop. */
01960   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
01961 
01962   Trackdir td = v->GetVehicleTrackdir();
01963 
01964   /* On a tile with a red non-pbs signal, don't look ahead. */
01965   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
01966       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
01967       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
01968 
01969   CFollowTrackRail ft(v);
01970   if (!ft.Follow(v->tile, td)) return;
01971 
01972   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
01973     /* Next tile is not reserved. */
01974     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
01975       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
01976         /* If the next tile is a PBS signal, try to make a reservation. */
01977         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
01978         if (_settings_game.pf.forbid_90_deg) {
01979           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
01980         }
01981         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
01982       }
01983     }
01984   }
01985 }
01986 
01987 static bool CheckTrainStayInDepot(Train *v)
01988 {
01989   /* bail out if not all wagons are in the same depot or not in a depot at all */
01990   for (const Train *u = v; u != NULL; u = u->Next()) {
01991     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
01992   }
01993 
01994   /* if the train got no power, then keep it in the depot */
01995   if (v->gcache.cached_power == 0) {
01996     v->vehstatus |= VS_STOPPED;
01997     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
01998     return true;
01999   }
02000 
02001   SigSegState seg_state;
02002 
02003   if (v->force_proceed == TFP_NONE) {
02004     /* force proceed was not pressed */
02005     if (++v->wait_counter < 37) {
02006       SetWindowClassesDirty(WC_TRAINS_LIST);
02007       return true;
02008     }
02009 
02010     v->wait_counter = 0;
02011 
02012     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02013     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02014       /* Full and no PBS signal in block or depot reserved, can't exit. */
02015       SetWindowClassesDirty(WC_TRAINS_LIST);
02016       return true;
02017     }
02018   } else {
02019     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02020   }
02021 
02022   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02023   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02024     /* We need to have a reservation for this to work. */
02025     if (HasDepotReservation(v->tile)) return true;
02026     SetDepotReservation(v->tile, true);
02027     VehicleEnterDepot(v);
02028     return true;
02029   }
02030 
02031   /* Only leave when we can reserve a path to our destination. */
02032   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02033     /* No path and no force proceed. */
02034     SetWindowClassesDirty(WC_TRAINS_LIST);
02035     MarkTrainAsStuck(v);
02036     return true;
02037   }
02038 
02039   SetDepotReservation(v->tile, true);
02040   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02041 
02042   VehicleServiceInDepot(v);
02043   SetWindowClassesDirty(WC_TRAINS_LIST);
02044   v->PlayLeaveStationSound();
02045 
02046   v->track = TRACK_BIT_X;
02047   if (v->direction & 2) v->track = TRACK_BIT_Y;
02048 
02049   v->vehstatus &= ~VS_HIDDEN;
02050   v->cur_speed = 0;
02051 
02052   v->UpdateDeltaXY(v->direction);
02053   v->cur_image = v->GetImage(v->direction);
02054   VehicleMove(v, false);
02055   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02056   v->UpdateAcceleration();
02057   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02058 
02059   return false;
02060 }
02061 
02063 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02064 {
02065   DiagDirection dir = TrackdirToExitdir(track_dir);
02066 
02067   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02068     /* Are we just leaving a tunnel/bridge? */
02069     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02070       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02071 
02072       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02073         /* Free the reservation only if no other train is on the tiles. */
02074         SetTunnelBridgeReservation(tile, false);
02075         SetTunnelBridgeReservation(end, false);
02076 
02077         if (_settings_client.gui.show_track_reservation) {
02078           MarkTileDirtyByTile(tile);
02079           MarkTileDirtyByTile(end);
02080         }
02081       }
02082     }
02083   } else if (IsRailStationTile(tile)) {
02084     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02085     /* If the new tile is not a further tile of the same station, we
02086      * clear the reservation for the whole platform. */
02087     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02088       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02089     }
02090   } else {
02091     /* Any other tile */
02092     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02093   }
02094 }
02095 
02097 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02098 {
02099   assert(v->IsFrontEngine());
02100 
02101   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02102   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02103   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02104   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02105 
02106   /* Don't free reservation if it's not ours. */
02107   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02108 
02109   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02110   while (ft.Follow(tile, td)) {
02111     tile = ft.m_new_tile;
02112     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02113     td = RemoveFirstTrackdir(&bits);
02114     assert(bits == TRACKDIR_BIT_NONE);
02115 
02116     if (!IsValidTrackdir(td)) break;
02117 
02118     if (IsTileType(tile, MP_RAILWAY)) {
02119       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02120         /* Conventional signal along trackdir: remove reservation and stop. */
02121         UnreserveRailTrack(tile, TrackdirToTrack(td));
02122         break;
02123       }
02124       if (HasPbsSignalOnTrackdir(tile, td)) {
02125         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02126           /* Red PBS signal? Can't be our reservation, would be green then. */
02127           break;
02128         } else {
02129           /* Turn the signal back to red. */
02130           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02131           MarkTileDirtyByTile(tile);
02132         }
02133       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02134         break;
02135       }
02136     }
02137 
02138     /* Don't free first station/bridge/tunnel if we are on it. */
02139     if (free_tile || (!(ft.m_is_station && GetStationIndex(ft.m_new_tile) == station_id) && !ft.m_is_tunnel && !ft.m_is_bridge)) ClearPathReservation(v, tile, td);
02140 
02141     free_tile = true;
02142   }
02143 }
02144 
02145 static const byte _initial_tile_subcoord[6][4][3] = {
02146 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02147 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02148 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02149 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02150 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02151 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02152 };
02153 
02166 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02167 {
02168   switch (_settings_game.pf.pathfinder_for_trains) {
02169     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02170     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02171 
02172     default: NOT_REACHED();
02173   }
02174 }
02175 
02181 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02182 {
02183   PBSTileInfo origin = FollowTrainReservation(v);
02184 
02185   CFollowTrackRail ft(v);
02186 
02187   TileIndex tile = origin.tile;
02188   Trackdir  cur_td = origin.trackdir;
02189   while (ft.Follow(tile, cur_td)) {
02190     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02191       /* Possible signal tile. */
02192       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02193     }
02194 
02195     if (_settings_game.pf.forbid_90_deg) {
02196       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02197       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02198     }
02199 
02200     /* Station, depot or waypoint are a possible target. */
02201     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02202     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02203       /* Choice found or possible target encountered.
02204        * On finding a possible target, we need to stop and let the pathfinder handle the
02205        * remaining path. This is because we don't know if this target is in one of our
02206        * orders, so we might cause pathfinding to fail later on if we find a choice.
02207        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02208        * a wrong path not leading to our next destination. */
02209       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02210 
02211       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02212        * actually starts its search at the first unreserved tile. */
02213       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02214 
02215       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02216       if (new_tracks) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02217       if (enterdir) *enterdir = ft.m_exitdir;
02218       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02219     }
02220 
02221     tile = ft.m_new_tile;
02222     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02223 
02224     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02225       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02226       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02227       /* Safe position is all good, path valid and okay. */
02228       return PBSTileInfo(tile, cur_td, true);
02229     }
02230 
02231     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02232   }
02233 
02234   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02235     /* End of line, path valid and okay. */
02236     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02237   }
02238 
02239   /* Sorry, can't reserve path, back out. */
02240   tile = origin.tile;
02241   cur_td = origin.trackdir;
02242   TileIndex stopped = ft.m_old_tile;
02243   Trackdir  stopped_td = ft.m_old_td;
02244   while (tile != stopped || cur_td != stopped_td) {
02245     if (!ft.Follow(tile, cur_td)) break;
02246 
02247     if (_settings_game.pf.forbid_90_deg) {
02248       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02249       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02250     }
02251     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02252 
02253     tile = ft.m_new_tile;
02254     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02255 
02256     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02257   }
02258 
02259   /* Path invalid. */
02260   return PBSTileInfo();
02261 }
02262 
02273 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02274 {
02275   switch (_settings_game.pf.pathfinder_for_trains) {
02276     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02277     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02278 
02279     default: NOT_REACHED();
02280   }
02281 }
02282 
02284 class VehicleOrderSaver
02285 {
02286 private:
02287   Vehicle        *v;
02288   Order          old_order;
02289   TileIndex      old_dest_tile;
02290   StationID      old_last_station_visited;
02291   VehicleOrderID index;
02292 
02293 public:
02294   VehicleOrderSaver(Vehicle *_v) :
02295     v(_v),
02296     old_order(_v->current_order),
02297     old_dest_tile(_v->dest_tile),
02298     old_last_station_visited(_v->last_station_visited),
02299     index(_v->cur_real_order_index)
02300   {
02301   }
02302 
02303   ~VehicleOrderSaver()
02304   {
02305     this->v->current_order = this->old_order;
02306     this->v->dest_tile = this->old_dest_tile;
02307     this->v->last_station_visited = this->old_last_station_visited;
02308   }
02309 
02315   bool SwitchToNextOrder(bool skip_first)
02316   {
02317     if (this->v->GetNumOrders() == 0) return false;
02318 
02319     if (skip_first) ++this->index;
02320 
02321     int conditional_depth = 0;
02322 
02323     do {
02324       /* Wrap around. */
02325       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02326 
02327       Order *order = this->v->GetOrder(this->index);
02328       assert(order != NULL);
02329 
02330       switch (order->GetType()) {
02331         case OT_GOTO_DEPOT:
02332           /* Skip service in depot orders when the train doesn't need service. */
02333           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02334         case OT_GOTO_STATION:
02335         case OT_GOTO_WAYPOINT:
02336           this->v->current_order = *order;
02337           UpdateOrderDest(this->v, order);
02338           return true;
02339         case OT_CONDITIONAL: {
02340           if (conditional_depth > this->v->GetNumOrders()) return false;
02341           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02342           if (next != INVALID_VEH_ORDER_ID) {
02343             conditional_depth++;
02344             this->index = next;
02345             /* Don't increment next, so no break here. */
02346             continue;
02347           }
02348           break;
02349         }
02350         default:
02351           break;
02352       }
02353       /* Don't increment inside the while because otherwise conditional
02354        * orders can lead to an infinite loop. */
02355       ++this->index;
02356     } while (this->index != this->v->cur_real_order_index);
02357 
02358     return false;
02359   }
02360 };
02361 
02362 /* choose a track */
02363 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02364 {
02365   Track best_track = INVALID_TRACK;
02366   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02367   bool changed_signal = false;
02368 
02369   assert((tracks & ~TRACK_BIT_MASK) == 0);
02370 
02371   if (got_reservation != NULL) *got_reservation = false;
02372 
02373   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02374   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02375   /* Do we have a suitable reserved track? */
02376   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02377 
02378   /* Quick return in case only one possible track is available */
02379   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02380     Track track = FindFirstTrack(tracks);
02381     /* We need to check for signals only here, as a junction tile can't have signals. */
02382     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02383       do_track_reservation = true;
02384       changed_signal = true;
02385       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02386     } else if (!do_track_reservation) {
02387       return track;
02388     }
02389     best_track = track;
02390   }
02391 
02392   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02393   DiagDirection dest_enterdir = enterdir;
02394   if (do_track_reservation) {
02395     /* Check if the train needs service here, so it has a chance to always find a depot.
02396      * Also check if the current order is a service order so we don't reserve a path to
02397      * the destination but instead to the next one if service isn't needed. */
02398     CheckIfTrainNeedsService(v);
02399     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02400 
02401     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02402     if (res_dest.tile == INVALID_TILE) {
02403       /* Reservation failed? */
02404       if (mark_stuck) MarkTrainAsStuck(v);
02405       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02406       return FindFirstTrack(tracks);
02407     }
02408   }
02409 
02410   /* Save the current train order. The destructor will restore the old order on function exit. */
02411   VehicleOrderSaver orders(v);
02412 
02413   /* If the current tile is the destination of the current order and
02414    * a reservation was requested, advance to the next order.
02415    * Don't advance on a depot order as depots are always safe end points
02416    * for a path and no look-ahead is necessary. This also avoids a
02417    * problem with depot orders not part of the order list when the
02418    * order list itself is empty. */
02419   if (v->current_order.IsType(OT_LEAVESTATION)) {
02420     orders.SwitchToNextOrder(false);
02421   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02422       v->current_order.IsType(OT_GOTO_STATION) ?
02423       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02424       v->tile == v->dest_tile))) {
02425     orders.SwitchToNextOrder(true);
02426   }
02427 
02428   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02429     /* Pathfinders are able to tell that route was only 'guessed'. */
02430     bool      path_found = true;
02431     TileIndex new_tile = res_dest.tile;
02432 
02433     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02434     if (new_tile == tile) best_track = next_track;
02435     v->HandlePathfindingResult(path_found);
02436   }
02437 
02438   /* No track reservation requested -> finished. */
02439   if (!do_track_reservation) return best_track;
02440 
02441   /* A path was found, but could not be reserved. */
02442   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02443     if (mark_stuck) MarkTrainAsStuck(v);
02444     FreeTrainTrackReservation(v);
02445     return best_track;
02446   }
02447 
02448   /* No possible reservation target found, we are probably lost. */
02449   if (res_dest.tile == INVALID_TILE) {
02450     /* Try to find any safe destination. */
02451     PBSTileInfo origin = FollowTrainReservation(v);
02452     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02453       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02454       best_track = FindFirstTrack(res);
02455       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02456       if (got_reservation != NULL) *got_reservation = true;
02457       if (changed_signal) MarkTileDirtyByTile(tile);
02458     } else {
02459       FreeTrainTrackReservation(v);
02460       if (mark_stuck) MarkTrainAsStuck(v);
02461     }
02462     return best_track;
02463   }
02464 
02465   if (got_reservation != NULL) *got_reservation = true;
02466 
02467   /* Reservation target found and free, check if it is safe. */
02468   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02469     /* Extend reservation until we have found a safe position. */
02470     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02471     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02472     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02473     if (_settings_game.pf.forbid_90_deg) {
02474       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02475     }
02476 
02477     /* Get next order with destination. */
02478     if (orders.SwitchToNextOrder(true)) {
02479       PBSTileInfo cur_dest;
02480       bool path_found;
02481       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02482       if (cur_dest.tile != INVALID_TILE) {
02483         res_dest = cur_dest;
02484         if (res_dest.okay) continue;
02485         /* Path found, but could not be reserved. */
02486         FreeTrainTrackReservation(v);
02487         if (mark_stuck) MarkTrainAsStuck(v);
02488         if (got_reservation != NULL) *got_reservation = false;
02489         changed_signal = false;
02490         break;
02491       }
02492     }
02493     /* No order or no safe position found, try any position. */
02494     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02495       FreeTrainTrackReservation(v);
02496       if (mark_stuck) MarkTrainAsStuck(v);
02497       if (got_reservation != NULL) *got_reservation = false;
02498       changed_signal = false;
02499     }
02500     break;
02501   }
02502 
02503   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02504 
02505   if (changed_signal) MarkTileDirtyByTile(tile);
02506 
02507   return best_track;
02508 }
02509 
02518 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02519 {
02520   assert(v->IsFrontEngine());
02521 
02522   /* We have to handle depots specially as the track follower won't look
02523    * at the depot tile itself but starts from the next tile. If we are still
02524    * inside the depot, a depot reservation can never be ours. */
02525   if (v->track == TRACK_BIT_DEPOT) {
02526     if (HasDepotReservation(v->tile)) {
02527       if (mark_as_stuck) MarkTrainAsStuck(v);
02528       return false;
02529     } else {
02530       /* Depot not reserved, but the next tile might be. */
02531       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02532       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02533     }
02534   }
02535 
02536   Vehicle *other_train = NULL;
02537   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02538   /* The path we are driving on is already blocked by some other train.
02539    * This can only happen in certain situations when mixing path and
02540    * block signals or when changing tracks and/or signals.
02541    * Exit here as doing any further reservations will probably just
02542    * make matters worse. */
02543   if (other_train != NULL && other_train->index != v->index) {
02544     if (mark_as_stuck) MarkTrainAsStuck(v);
02545     return false;
02546   }
02547   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02548   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02549     /* Can't be stuck then. */
02550     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
02551     ClrBit(v->flags, VRF_TRAIN_STUCK);
02552     return true;
02553   }
02554 
02555   /* If we are in a depot, tentatively reserve the depot. */
02556   if (v->track == TRACK_BIT_DEPOT) {
02557     SetDepotReservation(v->tile, true);
02558     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02559   }
02560 
02561   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02562   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02563   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02564 
02565   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02566 
02567   bool res_made = false;
02568   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02569 
02570   if (!res_made) {
02571     /* Free the depot reservation as well. */
02572     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02573     return false;
02574   }
02575 
02576   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02577     v->wait_counter = 0;
02578     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
02579   }
02580   ClrBit(v->flags, VRF_TRAIN_STUCK);
02581   return true;
02582 }
02583 
02584 
02585 static bool CheckReverseTrain(const Train *v)
02586 {
02587   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02588       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02589       !(v->direction & 1)) {
02590     return false;
02591   }
02592 
02593   assert(v->track != TRACK_BIT_NONE);
02594 
02595   switch (_settings_game.pf.pathfinder_for_trains) {
02596     case VPF_NPF: return NPFTrainCheckReverse(v);
02597     case VPF_YAPF: return YapfTrainCheckReverse(v);
02598 
02599     default: NOT_REACHED();
02600   }
02601 }
02602 
02603 TileIndex Train::GetOrderStationLocation(StationID station)
02604 {
02605   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02606 
02607   const Station *st = Station::Get(station);
02608   if (!(st->facilities & FACIL_TRAIN)) {
02609     /* The destination station has no trainstation tiles. */
02610     this->IncrementRealOrderIndex();
02611     return 0;
02612   }
02613 
02614   return st->xy;
02615 }
02616 
02617 void Train::MarkDirty()
02618 {
02619   Train *v = this;
02620   do {
02621     v->UpdateViewport(false, false);
02622   } while ((v = v->Next()) != NULL);
02623 
02624   /* need to update acceleration and cached values since the goods on the train changed. */
02625   this->CargoChanged();
02626   this->UpdateAcceleration();
02627 }
02628 
02636 int Train::UpdateSpeed()
02637 {
02638   switch (_settings_game.vehicle.train_acceleration_model) {
02639     default: NOT_REACHED();
02640     case AM_ORIGINAL:
02641       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, this->gcache.cached_max_track_speed);
02642 
02643     case AM_REALISTIC:
02644       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02645   }
02646 }
02647 
02653 static void TrainEnterStation(Train *v, StationID station)
02654 {
02655   v->last_station_visited = station;
02656 
02657   /* check if a train ever visited this station before */
02658   Station *st = Station::Get(station);
02659   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02660     st->had_vehicle_of_type |= HVOT_TRAIN;
02661     SetDParam(0, st->index);
02662     AddVehicleNewsItem(
02663       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02664       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
02665       v->index,
02666       st->index
02667     );
02668     AI::NewEvent(v->owner, new AIEventStationFirstVehicle(st->index, v->index));
02669   }
02670 
02671   v->force_proceed = TFP_NONE;
02672   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02673 
02674   v->BeginLoading();
02675 
02676   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02677 }
02678 
02679 /* Check if the vehicle is compatible with the specified tile */
02680 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02681 {
02682   return IsTileOwner(tile, v->owner) &&
02683       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02684 }
02685 
02686 struct RailtypeSlowdownParams {
02687   byte small_turn, large_turn;
02688   byte z_up; // fraction to remove when moving up
02689   byte z_down; // fraction to remove when moving down
02690 };
02691 
02692 static const RailtypeSlowdownParams _railtype_slowdown[] = {
02693   /* normal accel */
02694   {256 / 4, 256 / 2, 256 / 4, 2}, 
02695   {256 / 4, 256 / 2, 256 / 4, 2}, 
02696   {256 / 4, 256 / 2, 256 / 4, 2}, 
02697   {0,       256 / 2, 256 / 4, 2}, 
02698 };
02699 
02701 static inline void AffectSpeedByZChange(Train *v, byte old_z)
02702 {
02703   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02704 
02705   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
02706 
02707   if (old_z < v->z_pos) {
02708     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
02709   } else {
02710     uint16 spd = v->cur_speed + rsp->z_down;
02711     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02712   }
02713 }
02714 
02715 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02716 {
02717   if (IsTileType(tile, MP_RAILWAY) &&
02718       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02719     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02720     Trackdir trackdir = FindFirstTrackdir(tracks);
02721     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02722       /* A PBS block with a non-PBS signal facing us? */
02723       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02724     }
02725   }
02726   return false;
02727 }
02728 
02732 void Train::ReserveTrackUnderConsist() const
02733 {
02734   for (const Train *u = this; u != NULL; u = u->Next()) {
02735     switch (u->track) {
02736       case TRACK_BIT_WORMHOLE:
02737         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02738         break;
02739       case TRACK_BIT_DEPOT:
02740         break;
02741       default:
02742         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02743         break;
02744     }
02745   }
02746 }
02747 
02748 uint Train::Crash(bool flooded)
02749 {
02750   uint pass = 0;
02751   if (this->IsFrontEngine()) {
02752     pass += 2; // driver
02753 
02754     /* Remove the reserved path in front of the train if it is not stuck.
02755      * Also clear all reserved tracks the train is currently on. */
02756     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02757     for (const Train *v = this; v != NULL; v = v->Next()) {
02758       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02759       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02760         /* ClearPathReservation will not free the wormhole exit
02761          * if the train has just entered the wormhole. */
02762         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02763       }
02764     }
02765 
02766     /* we may need to update crossing we were approaching,
02767      * but must be updated after the train has been marked crashed */
02768     TileIndex crossing = TrainApproachingCrossingTile(this);
02769     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02770 
02771     /* Remove the loading indicators (if any) */
02772     HideFillingPercent(&this->fill_percent_te_id);
02773   }
02774 
02775   pass += this->GroundVehicleBase::Crash(flooded);
02776 
02777   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02778   return pass;
02779 }
02780 
02787 static uint TrainCrashed(Train *v)
02788 {
02789   uint num = 0;
02790 
02791   /* do not crash train twice */
02792   if (!(v->vehstatus & VS_CRASHED)) {
02793     num = v->Crash();
02794     AI::NewEvent(v->owner, new AIEventVehicleCrashed(v->index, v->tile, AIEventVehicleCrashed::CRASH_TRAIN));
02795   }
02796 
02797   /* Try to re-reserve track under already crashed train too.
02798    * Crash() clears the reservation! */
02799   v->ReserveTrackUnderConsist();
02800 
02801   return num;
02802 }
02803 
02804 struct TrainCollideChecker {
02805   Train *v; 
02806   uint num; 
02807 };
02808 
02809 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02810 {
02811   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02812 
02813   /* not a train or in depot */
02814   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02815 
02816   /* do not crash into trains of another company. */
02817   if (v->owner != tcc->v->owner) return NULL;
02818 
02819   /* get first vehicle now to make most usual checks faster */
02820   Train *coll = Train::From(v)->First();
02821 
02822   /* can't collide with own wagons */
02823   if (coll == tcc->v) return NULL;
02824 
02825   int x_diff = v->x_pos - tcc->v->x_pos;
02826   int y_diff = v->y_pos - tcc->v->y_pos;
02827 
02828   /* Do fast calculation to check whether trains are not in close vicinity
02829    * and quickly reject trains distant enough for any collision.
02830    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02831    * Differences are then ORed and then we check for any higher bits */
02832   uint hash = (y_diff + 7) | (x_diff + 7);
02833   if (hash & ~15) return NULL;
02834 
02835   /* Slower check using multiplication */
02836   if (x_diff * x_diff + y_diff * y_diff > 25) return NULL;
02837 
02838   /* Happens when there is a train under bridge next to bridge head */
02839   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02840 
02841   /* crash both trains */
02842   tcc->num += TrainCrashed(tcc->v);
02843   tcc->num += TrainCrashed(coll);
02844 
02845   return NULL; // continue searching
02846 }
02847 
02854 static bool CheckTrainCollision(Train *v)
02855 {
02856   /* can't collide in depot */
02857   if (v->track == TRACK_BIT_DEPOT) return false;
02858 
02859   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
02860 
02861   TrainCollideChecker tcc;
02862   tcc.v = v;
02863   tcc.num = 0;
02864 
02865   /* find colliding vehicles */
02866   if (v->track == TRACK_BIT_WORMHOLE) {
02867     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
02868     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
02869   } else {
02870     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
02871   }
02872 
02873   /* any dead -> no crash */
02874   if (tcc.num == 0) return false;
02875 
02876   SetDParam(0, tcc.num);
02877   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH,
02878     NS_ACCIDENT,
02879     v->index
02880   );
02881 
02882   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
02883   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
02884   return true;
02885 }
02886 
02887 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
02888 {
02889   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
02890 
02891   Train *t = Train::From(v);
02892   DiagDirection exitdir = *(DiagDirection *)data;
02893 
02894   /* not front engine of a train, inside wormhole or depot, crashed */
02895   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
02896 
02897   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
02898 
02899   return t;
02900 }
02901 
02902 static void TrainController(Train *v, Vehicle *nomove)
02903 {
02904   Train *first = v->First();
02905   Train *prev;
02906   bool direction_changed = false; // has direction of any part changed?
02907 
02908   /* For every vehicle after and including the given vehicle */
02909   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
02910     DiagDirection enterdir = DIAGDIR_BEGIN;
02911     bool update_signals_crossing = false; // will we update signals or crossing state?
02912 
02913     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
02914     if (v->track != TRACK_BIT_WORMHOLE) {
02915       /* Not inside tunnel */
02916       if (gp.old_tile == gp.new_tile) {
02917         /* Staying in the old tile */
02918         if (v->track == TRACK_BIT_DEPOT) {
02919           /* Inside depot */
02920           gp.x = v->x_pos;
02921           gp.y = v->y_pos;
02922         } else {
02923           /* Not inside depot */
02924 
02925           /* Reverse when we are at the end of the track already, do not move to the new position */
02926           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v)) return;
02927 
02928           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
02929           if (HasBit(r, VETS_CANNOT_ENTER)) {
02930             goto invalid_rail;
02931           }
02932           if (HasBit(r, VETS_ENTERED_STATION)) {
02933             /* The new position is the end of the platform */
02934             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
02935           }
02936         }
02937       } else {
02938         /* A new tile is about to be entered. */
02939 
02940         /* Determine what direction we're entering the new tile from */
02941         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
02942         assert(IsValidDiagDirection(enterdir));
02943 
02944         /* Get the status of the tracks in the new tile and mask
02945          * away the bits that aren't reachable. */
02946         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
02947         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
02948 
02949         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
02950         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
02951 
02952         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
02953         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
02954           /* We allow wagons to make 90 deg turns, because forbid_90_deg
02955            * can be switched on halfway a turn */
02956           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
02957         }
02958 
02959         if (bits == TRACK_BIT_NONE) goto invalid_rail;
02960 
02961         /* Check if the new tile constrains tracks that are compatible
02962          * with the current train, if not, bail out. */
02963         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
02964 
02965         TrackBits chosen_track;
02966         if (prev == NULL) {
02967           /* Currently the locomotive is active. Determine which one of the
02968            * available tracks to choose */
02969           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
02970           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
02971 
02972           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
02973             /* For each signal we find decrease the counter by one.
02974              * We start at two, so the first signal we pass decreases
02975              * this to one, then if we reach the next signal it is
02976              * decreased to zero and we won't pass that new signal. */
02977             Trackdir dir = FindFirstTrackdir(trackdirbits);
02978             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
02979                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
02980               /* However, we do not want to be stopped by PBS signals
02981                * entered via the back. */
02982               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
02983               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02984             }
02985           }
02986 
02987           /* Check if it's a red signal and that force proceed is not clicked. */
02988           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
02989             /* In front of a red signal */
02990             Trackdir i = FindFirstTrackdir(trackdirbits);
02991 
02992             /* Don't handle stuck trains here. */
02993             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return;
02994 
02995             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
02996               v->cur_speed = 0;
02997               v->subspeed = 0;
02998               v->progress = 255 - 100;
02999               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return;
03000             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03001               v->cur_speed = 0;
03002               v->subspeed = 0;
03003               v->progress = 255 - 10;
03004               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03005                 DiagDirection exitdir = TrackdirToExitdir(i);
03006                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03007 
03008                 exitdir = ReverseDiagDir(exitdir);
03009 
03010                 /* check if a train is waiting on the other side */
03011                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return;
03012               }
03013             }
03014 
03015             /* If we would reverse but are currently in a PBS block and
03016              * reversing of stuck trains is disabled, don't reverse.
03017              * This does not apply if the reason for reversing is a one-way
03018              * signal blocking us, because a train would then be stuck forever. */
03019             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03020                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03021               v->wait_counter = 0;
03022               return;
03023             }
03024             goto reverse_train_direction;
03025           } else {
03026             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03027           }
03028         } else {
03029           /* The wagon is active, simply follow the prev vehicle. */
03030           if (prev->tile == gp.new_tile) {
03031             /* Choose the same track as prev */
03032             if (prev->track == TRACK_BIT_WORMHOLE) {
03033               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03034                * However, just choose the track into the wormhole. */
03035               assert(IsTunnel(prev->tile));
03036               chosen_track = bits;
03037             } else {
03038               chosen_track = prev->track;
03039             }
03040           } else {
03041             /* Choose the track that leads to the tile where prev is.
03042              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03043              * I.e. when the tile between them has only space for a single vehicle like
03044              *  1) horizontal/vertical track tiles and
03045              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03046              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03047              */
03048             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03049               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03050               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03051               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03052               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03053             };
03054             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03055             assert(IsValidDiagDirection(exitdir));
03056             chosen_track = _connecting_track[enterdir][exitdir];
03057           }
03058           chosen_track &= bits;
03059         }
03060 
03061         /* Make sure chosen track is a valid track */
03062         assert(
03063             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03064             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03065             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03066 
03067         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03068         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03069         gp.x = (gp.x & ~0xF) | b[0];
03070         gp.y = (gp.y & ~0xF) | b[1];
03071         Direction chosen_dir = (Direction)b[2];
03072 
03073         /* Call the landscape function and tell it that the vehicle entered the tile */
03074         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03075         if (HasBit(r, VETS_CANNOT_ENTER)) {
03076           goto invalid_rail;
03077         }
03078 
03079         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03080           Track track = FindFirstTrack(chosen_track);
03081           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03082           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03083             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03084             MarkTileDirtyByTile(gp.new_tile);
03085           }
03086 
03087           /* Clear any track reservation when the last vehicle leaves the tile */
03088           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03089 
03090           v->tile = gp.new_tile;
03091 
03092           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03093             v->First()->RailtypeChanged();
03094           }
03095 
03096           v->track = chosen_track;
03097           assert(v->track);
03098         }
03099 
03100         /* We need to update signal status, but after the vehicle position hash
03101          * has been updated by UpdateInclination() */
03102         update_signals_crossing = true;
03103 
03104         if (chosen_dir != v->direction) {
03105           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03106             const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
03107             DirDiff diff = DirDifference(v->direction, chosen_dir);
03108             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03109           }
03110           direction_changed = true;
03111           v->direction = chosen_dir;
03112         }
03113 
03114         if (v->IsFrontEngine()) {
03115           v->wait_counter = 0;
03116 
03117           /* If we are approaching a crossing that is reserved, play the sound now. */
03118           TileIndex crossing = TrainApproachingCrossingTile(v);
03119           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03120 
03121           /* Always try to extend the reservation when entering a tile. */
03122           CheckNextTrainTile(v);
03123         }
03124 
03125         if (HasBit(r, VETS_ENTERED_STATION)) {
03126           /* The new position is the location where we want to stop */
03127           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03128         }
03129       }
03130     } else {
03131       /* In a tunnel or on a bridge
03132        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03133        * - for bridges, only the middle part - without the bridge heads */
03134       if (!(v->vehstatus & VS_HIDDEN)) {
03135         Train *first = v->First();
03136         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03137       }
03138 
03139       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03140         /* Perform look-ahead on tunnel exit. */
03141         if (v->IsFrontEngine()) {
03142           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03143           CheckNextTrainTile(v);
03144         }
03145         /* Prevent v->UpdateInclination() being called with wrong parameters.
03146          * This could happen if the train was reversed inside the tunnel/bridge. */
03147         if (gp.old_tile == gp.new_tile) {
03148           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03149         }
03150       } else {
03151         v->x_pos = gp.x;
03152         v->y_pos = gp.y;
03153         VehicleMove(v, !(v->vehstatus & VS_HIDDEN));
03154         continue;
03155       }
03156     }
03157 
03158     /* update image of train, as well as delta XY */
03159     v->UpdateDeltaXY(v->direction);
03160 
03161     v->x_pos = gp.x;
03162     v->y_pos = gp.y;
03163 
03164     /* update the Z position of the vehicle */
03165     byte old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03166 
03167     if (prev == NULL) {
03168       /* This is the first vehicle in the train */
03169       AffectSpeedByZChange(v, old_z);
03170     }
03171 
03172     if (update_signals_crossing) {
03173       if (v->IsFrontEngine()) {
03174         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03175           /* We are entering a block with PBS signals right now, but
03176            * not through a PBS signal. This means we don't have a
03177            * reservation right now. As a conventional signal will only
03178            * ever be green if no other train is in the block, getting
03179            * a path should always be possible. If the player built
03180            * such a strange network that it is not possible, the train
03181            * will be marked as stuck and the player has to deal with
03182            * the problem. */
03183           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03184               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03185               !TryPathReserve(v)) {
03186             MarkTrainAsStuck(v);
03187           }
03188         }
03189       }
03190 
03191       /* Signals can only change when the first
03192        * (above) or the last vehicle moves. */
03193       if (v->Next() == NULL) {
03194         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03195         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03196       }
03197     }
03198 
03199     /* Do not check on every tick to save some computing time. */
03200     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03201   }
03202 
03203   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03204 
03205   return;
03206 
03207 invalid_rail:
03208   /* We've reached end of line?? */
03209   if (prev != NULL) error("Disconnecting train");
03210 
03211 reverse_train_direction:
03212   v->wait_counter = 0;
03213   v->cur_speed = 0;
03214   v->subspeed = 0;
03215   ReverseTrainDirection(v);
03216 }
03217 
03224 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03225 {
03226   TrackBits *trackbits = (TrackBits *)data;
03227 
03228   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03229     TrackBits train_tbits = Train::From(v)->track;
03230     if (train_tbits == TRACK_BIT_WORMHOLE) {
03231       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03232       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03233     } else if (train_tbits != TRACK_BIT_DEPOT) {
03234       *trackbits |= train_tbits;
03235     }
03236   }
03237 
03238   return NULL;
03239 }
03240 
03248 static void DeleteLastWagon(Train *v)
03249 {
03250   Train *first = v->First();
03251 
03252   /* Go to the last wagon and delete the link pointing there
03253    * *u is then the one-before-last wagon, and *v the last
03254    * one which will physically be removed */
03255   Train *u = v;
03256   for (; v->Next() != NULL; v = v->Next()) u = v;
03257   u->SetNext(NULL);
03258 
03259   if (first != v) {
03260     /* Recalculate cached train properties */
03261     first->ConsistChanged(false);
03262     /* Update the depot window if the first vehicle is in depot -
03263      * if v == first, then it is updated in PreDestructor() */
03264     if (first->track == TRACK_BIT_DEPOT) {
03265       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03266     }
03267   }
03268 
03269   /* 'v' shouldn't be accessed after it has been deleted */
03270   TrackBits trackbits = v->track;
03271   TileIndex tile = v->tile;
03272   Owner owner = v->owner;
03273 
03274   delete v;
03275   v = NULL; // make sure nobody will try to read 'v' anymore
03276 
03277   if (trackbits == TRACK_BIT_WORMHOLE) {
03278     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03279     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03280   }
03281 
03282   Track track = TrackBitsToTrack(trackbits);
03283   if (HasReservedTracks(tile, trackbits)) {
03284     UnreserveRailTrack(tile, track);
03285 
03286     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03287     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03288     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03289 
03290     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03291     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03292     Track t;
03293     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03294   }
03295 
03296   /* check if the wagon was on a road/rail-crossing */
03297   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03298 
03299   /* Update signals */
03300   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03301     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03302   } else {
03303     SetSignalsOnBothDir(tile, track, owner);
03304   }
03305 }
03306 
03311 static void ChangeTrainDirRandomly(Train *v)
03312 {
03313   static const DirDiff delta[] = {
03314     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03315   };
03316 
03317   do {
03318     /* We don't need to twist around vehicles if they're not visible */
03319     if (!(v->vehstatus & VS_HIDDEN)) {
03320       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03321       v->UpdateDeltaXY(v->direction);
03322       v->cur_image = v->GetImage(v->direction);
03323       /* Refrain from updating the z position of the vehicle when on
03324        * a bridge, because UpdateInclination() will put the vehicle under
03325        * the bridge in that case */
03326       if (v->track != TRACK_BIT_WORMHOLE) v->UpdateInclination(false, false);
03327     }
03328   } while ((v = v->Next()) != NULL);
03329 }
03330 
03336 static bool HandleCrashedTrain(Train *v)
03337 {
03338   int state = ++v->crash_anim_pos;
03339 
03340   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03341     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03342   }
03343 
03344   uint32 r;
03345   if (state <= 200 && Chance16R(1, 7, r)) {
03346     int index = (r * 10 >> 16);
03347 
03348     Vehicle *u = v;
03349     do {
03350       if (--index < 0) {
03351         r = Random();
03352 
03353         CreateEffectVehicleRel(u,
03354           GB(r,  8, 3) + 2,
03355           GB(r, 16, 3) + 2,
03356           GB(r,  0, 3) + 5,
03357           EV_EXPLOSION_SMALL);
03358         break;
03359       }
03360     } while ((u = u->Next()) != NULL);
03361   }
03362 
03363   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03364 
03365   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03366     bool ret = v->Next() != NULL;
03367     DeleteLastWagon(v);
03368     return ret;
03369   }
03370 
03371   return true;
03372 }
03373 
03375 static const uint16 _breakdown_speeds[16] = {
03376   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03377 };
03378 
03379 
03387 static bool TrainApproachingLineEnd(Train *v, bool signal)
03388 {
03389   /* Calc position within the current tile */
03390   uint x = v->x_pos & 0xF;
03391   uint y = v->y_pos & 0xF;
03392 
03393   /* for diagonal directions, 'x' will be 0..15 -
03394    * for other directions, it will be 1, 3, 5, ..., 15 */
03395   switch (v->direction) {
03396     case DIR_N : x = ~x + ~y + 25; break;
03397     case DIR_NW: x = y;            // FALL THROUGH
03398     case DIR_NE: x = ~x + 16;      break;
03399     case DIR_E : x = ~x + y + 9;   break;
03400     case DIR_SE: x = y;            break;
03401     case DIR_S : x = x + y - 7;    break;
03402     case DIR_W : x = ~y + x + 9;   break;
03403     default: break;
03404   }
03405 
03406   /* do not reverse when approaching red signal */
03407   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 >= TILE_SIZE) {
03408     /* we are too near the tile end, reverse now */
03409     v->cur_speed = 0;
03410     ReverseTrainDirection(v);
03411     return false;
03412   }
03413 
03414   /* slow down */
03415   v->vehstatus |= VS_TRAIN_SLOWING;
03416   uint16 break_speed = _breakdown_speeds[x & 0xF];
03417   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03418 
03419   return true;
03420 }
03421 
03422 
03428 static bool TrainCanLeaveTile(const Train *v)
03429 {
03430   /* Exit if inside a tunnel/bridge or a depot */
03431   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03432 
03433   TileIndex tile = v->tile;
03434 
03435   /* entering a tunnel/bridge? */
03436   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03437     DiagDirection dir = GetTunnelBridgeDirection(tile);
03438     if (DiagDirToDir(dir) == v->direction) return false;
03439   }
03440 
03441   /* entering a depot? */
03442   if (IsRailDepotTile(tile)) {
03443     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03444     if (DiagDirToDir(dir) == v->direction) return false;
03445   }
03446 
03447   return true;
03448 }
03449 
03450 
03458 static TileIndex TrainApproachingCrossingTile(const Train *v)
03459 {
03460   assert(v->IsFrontEngine());
03461   assert(!(v->vehstatus & VS_CRASHED));
03462 
03463   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03464 
03465   DiagDirection dir = TrainExitDir(v->direction, v->track);
03466   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03467 
03468   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03469   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03470       !CheckCompatibleRail(v, tile)) {
03471     return INVALID_TILE;
03472   }
03473 
03474   return tile;
03475 }
03476 
03477 
03484 static bool TrainCheckIfLineEnds(Train *v)
03485 {
03486   /* First, handle broken down train */
03487 
03488   int t = v->breakdown_ctr;
03489   if (t > 1) {
03490     v->vehstatus |= VS_TRAIN_SLOWING;
03491 
03492     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03493     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03494   } else {
03495     v->vehstatus &= ~VS_TRAIN_SLOWING;
03496   }
03497 
03498   if (!TrainCanLeaveTile(v)) return true;
03499 
03500   /* Determine the non-diagonal direction in which we will exit this tile */
03501   DiagDirection dir = TrainExitDir(v->direction, v->track);
03502   /* Calculate next tile */
03503   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03504 
03505   /* Determine the track status on the next tile */
03506   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03507   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03508 
03509   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03510   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03511 
03512   /* We are sure the train is not entering a depot, it is detected above */
03513 
03514   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03515   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03516   if (_settings_game.pf.forbid_90_deg) {
03517     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03518   }
03519 
03520   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03521   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03522     return TrainApproachingLineEnd(v, false);
03523   }
03524 
03525   /* approaching red signal */
03526   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true);
03527 
03528   /* approaching a rail/road crossing? then make it red */
03529   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03530 
03531   return true;
03532 }
03533 
03534 
03535 static bool TrainLocoHandler(Train *v, bool mode)
03536 {
03537   /* train has crashed? */
03538   if (v->vehstatus & VS_CRASHED) {
03539     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03540   }
03541 
03542   if (v->force_proceed != TFP_NONE) {
03543     ClrBit(v->flags, VRF_TRAIN_STUCK);
03544     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03545   }
03546 
03547   /* train is broken down? */
03548   if (v->HandleBreakdown()) return true;
03549 
03550   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03551     ReverseTrainDirection(v);
03552   }
03553 
03554   /* exit if train is stopped */
03555   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03556 
03557   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03558   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03559     v->wait_counter = 0;
03560     v->cur_speed = 0;
03561     v->subspeed = 0;
03562     ClrBit(v->flags, VRF_LEAVING_STATION);
03563     ReverseTrainDirection(v);
03564     return true;
03565   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03566     /* Try to reserve a path when leaving the station as we
03567      * might not be marked as wanting a reservation, e.g.
03568      * when an overlength train gets turned around in a station. */
03569     DiagDirection dir = TrainExitDir(v->direction, v->track);
03570     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03571 
03572     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03573       TryPathReserve(v, true, true);
03574     }
03575     ClrBit(v->flags, VRF_LEAVING_STATION);
03576   }
03577 
03578   v->HandleLoading(mode);
03579 
03580   if (v->current_order.IsType(OT_LOADING)) return true;
03581 
03582   if (CheckTrainStayInDepot(v)) return true;
03583 
03584   if (!mode) v->ShowVisualEffect();
03585 
03586   /* We had no order but have an order now, do look ahead. */
03587   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03588     CheckNextTrainTile(v);
03589   }
03590 
03591   /* Handle stuck trains. */
03592   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03593     ++v->wait_counter;
03594 
03595     /* Should we try reversing this tick if still stuck? */
03596     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03597 
03598     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03599     if (!TryPathReserve(v)) {
03600       /* Still stuck. */
03601       if (turn_around) ReverseTrainDirection(v);
03602 
03603       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03604         /* Show message to player. */
03605         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03606           SetDParam(0, v->index);
03607           AddVehicleNewsItem(
03608             STR_NEWS_TRAIN_IS_STUCK,
03609             NS_ADVICE,
03610             v->index
03611           );
03612         }
03613         v->wait_counter = 0;
03614       }
03615       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03616       if (v->force_proceed == TFP_NONE) return true;
03617       ClrBit(v->flags, VRF_TRAIN_STUCK);
03618       v->wait_counter = 0;
03619       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03620     }
03621   }
03622 
03623   if (v->current_order.IsType(OT_LEAVESTATION)) {
03624     v->current_order.Free();
03625     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03626     return true;
03627   }
03628 
03629   int j = v->UpdateSpeed();
03630 
03631   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03632   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03633     /* If we manually stopped, we're not force-proceeding anymore. */
03634     v->force_proceed = TFP_NONE;
03635     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03636   }
03637 
03638   int adv_spd = v->GetAdvanceDistance();
03639   if (j < adv_spd) {
03640     /* if the vehicle has speed 0, update the last_speed field. */
03641     if (v->cur_speed == 0) v->SetLastSpeed();
03642   } else {
03643     TrainCheckIfLineEnds(v);
03644     /* Loop until the train has finished moving. */
03645     for (;;) {
03646       j -= adv_spd;
03647       TrainController(v, NULL);
03648       /* Don't continue to move if the train crashed. */
03649       if (CheckTrainCollision(v)) break;
03650       /* Determine distance to next map position */
03651       adv_spd = v->GetAdvanceDistance();
03652 
03653       /* No more moving this tick */
03654       if (j < adv_spd || v->cur_speed == 0) break;
03655 
03656       OrderType order_type = v->current_order.GetType();
03657       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03658       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03659             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03660             IsTileType(v->tile, MP_STATION) &&
03661             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03662         ProcessOrders(v);
03663       }
03664     }
03665     v->SetLastSpeed();
03666   }
03667 
03668   for (Train *u = v; u != NULL; u = u->Next()) {
03669     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03670 
03671     u->UpdateViewport(false, false);
03672   }
03673 
03674   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03675 
03676   return true;
03677 }
03678 
03679 
03680 
03681 Money Train::GetRunningCost() const
03682 {
03683   Money cost = 0;
03684   const Train *v = this;
03685 
03686   do {
03687     const Engine *e = Engine::Get(v->engine_type);
03688     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03689 
03690     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03691     if (cost_factor == 0) continue;
03692 
03693     /* Halve running cost for multiheaded parts */
03694     if (v->IsMultiheaded()) cost_factor /= 2;
03695 
03696     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->grf_prop.grffile);
03697   } while ((v = v->GetNextVehicle()) != NULL);
03698 
03699   return cost;
03700 }
03701 
03702 
03703 bool Train::Tick()
03704 {
03705   this->tick_counter++;
03706 
03707   if (this->IsFrontEngine()) {
03708     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03709 
03710     this->current_order_time++;
03711 
03712     if (!TrainLocoHandler(this, false)) return false;
03713 
03714     return TrainLocoHandler(this, true);
03715   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03716     /* Delete flooded standalone wagon chain */
03717     if (++this->crash_anim_pos >= 4400) {
03718       delete this;
03719       return false;
03720     }
03721   }
03722 
03723   return true;
03724 }
03725 
03726 static void CheckIfTrainNeedsService(Train *v)
03727 {
03728   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03729   if (v->IsInDepot()) {
03730     VehicleServiceInDepot(v);
03731     return;
03732   }
03733 
03734   uint max_penalty;
03735   switch (_settings_game.pf.pathfinder_for_trains) {
03736     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03737     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03738     default: NOT_REACHED();
03739   }
03740 
03741   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03742   /* Only go to the depot if it is not too far out of our way. */
03743   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03744     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03745       /* If we were already heading for a depot but it has
03746        * suddenly moved farther away, we continue our normal
03747        * schedule? */
03748       v->current_order.MakeDummy();
03749       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03750     }
03751     return;
03752   }
03753 
03754   DepotID depot = GetDepotIndex(tfdd.tile);
03755 
03756   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03757       v->current_order.GetDestination() != depot &&
03758       !Chance16(3, 16)) {
03759     return;
03760   }
03761 
03762   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03763   v->dest_tile = tfdd.tile;
03764   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03765 }
03766 
03767 void Train::OnNewDay()
03768 {
03769   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03770 
03771   if (this->IsFrontEngine()) {
03772     CheckVehicleBreakdown(this);
03773     AgeVehicle(this);
03774 
03775     CheckIfTrainNeedsService(this);
03776 
03777     CheckOrders(this);
03778 
03779     /* update destination */
03780     if (this->current_order.IsType(OT_GOTO_STATION)) {
03781       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03782       if (tile != INVALID_TILE) this->dest_tile = tile;
03783     }
03784 
03785     if (this->running_ticks != 0) {
03786       /* running costs */
03787       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03788 
03789       this->profit_this_year -= cost.GetCost();
03790       this->running_ticks = 0;
03791 
03792       SubtractMoneyFromCompanyFract(this->owner, cost);
03793 
03794       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03795       SetWindowClassesDirty(WC_TRAINS_LIST);
03796     }
03797   } else if (this->IsEngine()) {
03798     /* Also age engines that aren't front engines */
03799     AgeVehicle(this);
03800   }
03801 }
03802 
03803 Trackdir Train::GetVehicleTrackdir() const
03804 {
03805   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03806 
03807   if (this->track == TRACK_BIT_DEPOT) {
03808     /* We'll assume the train is facing outwards */
03809     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03810   }
03811 
03812   if (this->track == TRACK_BIT_WORMHOLE) {
03813     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03814     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03815   }
03816 
03817   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03818 }

Generated on Fri Mar 4 21:37:08 2011 for OpenTTD by  doxygen 1.6.1