train_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "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 #include "zoom_func.h"
00040 
00041 #include "table/strings.h"
00042 #include "table/train_cmd.h"
00043 
00044 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00045 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00046 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00047 static TileIndex TrainApproachingCrossingTile(const Train *v);
00048 static void CheckIfTrainNeedsService(Train *v);
00049 static void CheckNextTrainTile(Train *v);
00050 
00051 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00052 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00053 
00054 
00062 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00063 {
00064   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00065 
00066   DiagDirection diagdir = DirToDiagDir(direction);
00067 
00068   /* Determine the diagonal direction in which we will exit this tile */
00069   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00070     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00071   }
00072 
00073   return diagdir;
00074 }
00075 
00076 
00082 byte FreightWagonMult(CargoID cargo)
00083 {
00084   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00085   return _settings_game.vehicle.freight_trains;
00086 }
00087 
00089 void CheckTrainsLengths()
00090 {
00091   const Train *v;
00092   bool first = true;
00093 
00094   FOR_ALL_TRAINS(v) {
00095     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00096       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00097         if (u->track != TRACK_BIT_DEPOT) {
00098           if ((w->track != TRACK_BIT_DEPOT &&
00099               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00100               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00101             SetDParam(0, v->index);
00102             SetDParam(1, v->owner);
00103             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00104 
00105             if (!_networking && first) {
00106               first = false;
00107               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00108             }
00109             /* Break so we warn only once for each train. */
00110             break;
00111           }
00112         }
00113       }
00114     }
00115   }
00116 }
00117 
00122 void Train::RailtypeChanged()
00123 {
00124   for (Train *u = this; u != NULL; u = u->Next()) {
00125     /* The wagon-is-powered-state should not change, so the weight does not change. */
00126     u->UpdateVisualEffect(false);
00127   }
00128   this->PowerChanged();
00129   if (this->IsFrontEngine()) this->UpdateAcceleration();
00130 }
00131 
00138 void Train::ConsistChanged(bool same_length)
00139 {
00140   uint16 max_speed = UINT16_MAX;
00141 
00142   assert(this->IsFrontEngine() || this->IsFreeWagon());
00143 
00144   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00145   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00146   this->gcache.cached_total_length = 0;
00147   this->compatible_railtypes = RAILTYPES_NONE;
00148 
00149   bool train_can_tilt = true;
00150 
00151   for (Train *u = this; u != NULL; u = u->Next()) {
00152     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00153 
00154     /* Check the this->first cache. */
00155     assert(u->First() == this);
00156 
00157     /* update the 'first engine' */
00158     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00159     u->railtype = rvi_u->railtype;
00160 
00161     if (u->IsEngine()) first_engine = u->engine_type;
00162 
00163     /* Set user defined data to its default value */
00164     u->tcache.user_def_data = rvi_u->user_def_data;
00165     this->InvalidateNewGRFCache();
00166     u->InvalidateNewGRFCache();
00167   }
00168 
00169   for (Train *u = this; u != NULL; u = u->Next()) {
00170     /* Update user defined data (must be done before other properties) */
00171     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00172     this->InvalidateNewGRFCache();
00173     u->InvalidateNewGRFCache();
00174   }
00175 
00176   for (Train *u = this; u != NULL; u = u->Next()) {
00177     const Engine *e_u = u->GetEngine();
00178     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00179 
00180     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00181 
00182     /* Cache wagon override sprite group. NULL is returned if there is none */
00183     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00184 
00185     /* Reset colour map */
00186     u->colourmap = PAL_NONE;
00187 
00188     /* Update powered-wagon-status and visual effect */
00189     u->UpdateVisualEffect(true);
00190 
00191     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00192         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00193       /* wagon is powered */
00194       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00195     } else {
00196       ClrBit(u->flags, VRF_POWEREDWAGON);
00197     }
00198 
00199     if (!u->IsArticulatedPart()) {
00200       /* Do not count powered wagons for the compatible railtypes, as wagons always
00201          have railtype normal */
00202       if (rvi_u->power > 0) {
00203         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00204       }
00205 
00206       /* Some electric engines can be allowed to run on normal rail. It happens to all
00207        * existing electric engines when elrails are disabled and then re-enabled */
00208       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00209         u->railtype = RAILTYPE_RAIL;
00210         u->compatible_railtypes |= RAILTYPES_RAIL;
00211       }
00212 
00213       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00214       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00215         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00216         if (speed != 0) max_speed = min(speed, max_speed);
00217       }
00218     }
00219 
00220     u->cargo_cap = e_u->DetermineCapacity(u);
00221     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00222 
00223     /* check the vehicle length (callback) */
00224     uint16 veh_len = CALLBACK_FAILED;
00225     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00226       /* Use callback 36 */
00227       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00228     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00229       /* Use callback 11 */
00230       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00231     }
00232     if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00233       ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00234     }
00235     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00236     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00237 
00238     /* verify length hasn't changed */
00239     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00240 
00241     /* update vehicle length? */
00242     if (!same_length) u->gcache.cached_veh_length = veh_len;
00243 
00244     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00245     this->InvalidateNewGRFCache();
00246     u->InvalidateNewGRFCache();
00247   }
00248 
00249   /* store consist weight/max speed in cache */
00250   this->vcache.cached_max_speed = max_speed;
00251   this->tcache.cached_tilt = train_can_tilt;
00252   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00253 
00254   /* 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) */
00255   this->CargoChanged();
00256 
00257   if (this->IsFrontEngine()) {
00258     this->UpdateAcceleration();
00259     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00260     InvalidateWindowData(WC_VEHICLE_REFIT, this->index);
00261   }
00262 }
00263 
00274 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00275 {
00276   const Station *st = Station::Get(station_id);
00277   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00278   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00279 
00280   /* Default to the middle of the station for stations stops that are not in
00281    * the order list like intermediate stations when non-stop is disabled */
00282   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00283   if (v->gcache.cached_total_length >= *station_length) {
00284     /* The train is longer than the station, make it stop at the far end of the platform */
00285     osl = OSL_PLATFORM_FAR_END;
00286   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00287     osl = v->current_order.GetStopLocation();
00288   }
00289 
00290   /* The stop location of the FRONT! of the train */
00291   int stop;
00292   switch (osl) {
00293     default: NOT_REACHED();
00294 
00295     case OSL_PLATFORM_NEAR_END:
00296       stop = v->gcache.cached_total_length;
00297       break;
00298 
00299     case OSL_PLATFORM_MIDDLE:
00300       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00301       break;
00302 
00303     case OSL_PLATFORM_FAR_END:
00304       stop = *station_length;
00305       break;
00306   }
00307 
00308   /* Subtract half the front vehicle length of the train so we get the real
00309    * stop location of the train. */
00310   return stop - (v->gcache.cached_veh_length + 1) / 2;
00311 }
00312 
00313 
00318 int Train::GetCurveSpeedLimit() const
00319 {
00320   assert(this->First() == this);
00321 
00322   static const int absolute_max_speed = UINT16_MAX;
00323   int max_speed = absolute_max_speed;
00324 
00325   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00326 
00327   int curvecount[2] = {0, 0};
00328 
00329   /* first find the curve speed limit */
00330   int numcurve = 0;
00331   int sum = 0;
00332   int pos = 0;
00333   int lastpos = -1;
00334   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00335     Direction this_dir = u->direction;
00336     Direction next_dir = u->Next()->direction;
00337 
00338     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00339     if (dirdiff == DIRDIFF_SAME) continue;
00340 
00341     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00342     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00343     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00344       if (lastpos != -1) {
00345         numcurve++;
00346         sum += pos - lastpos;
00347         if (pos - lastpos == 1 && max_speed > 88) {
00348           max_speed = 88;
00349         }
00350       }
00351       lastpos = pos;
00352     }
00353 
00354     /* if we have a 90 degree turn, fix the speed limit to 60 */
00355     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00356       max_speed = 61;
00357     }
00358   }
00359 
00360   if (numcurve > 0 && max_speed > 88) {
00361     if (curvecount[0] == 1 && curvecount[1] == 1) {
00362       max_speed = absolute_max_speed;
00363     } else {
00364       sum /= numcurve;
00365       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00366     }
00367   }
00368 
00369   if (max_speed != absolute_max_speed) {
00370     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00371     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00372     max_speed += (max_speed / 2) * rti->curve_speed;
00373 
00374     if (this->tcache.cached_tilt) {
00375       /* Apply max_speed bonus of 20% for a tilting train */
00376       max_speed += max_speed / 5;
00377     }
00378   }
00379 
00380   return max_speed;
00381 }
00382 
00387 int Train::GetCurrentMaxSpeed() const
00388 {
00389   int max_speed = this->tcache.cached_max_curve_speed;
00390   assert(max_speed == this->GetCurveSpeedLimit());
00391 
00392   if (IsRailStationTile(this->tile)) {
00393     StationID sid = GetStationIndex(this->tile);
00394     if (this->current_order.ShouldStopAtStation(this, sid)) {
00395       int station_ahead;
00396       int station_length;
00397       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00398 
00399       /* The distance to go is whatever is still ahead of the train minus the
00400        * distance from the train's stop location to the end of the platform */
00401       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00402 
00403       if (distance_to_go > 0) {
00404         int st_max_speed = 120;
00405 
00406         int delta_v = this->cur_speed / (distance_to_go + 1);
00407         if (max_speed > (this->cur_speed - delta_v)) {
00408           st_max_speed = this->cur_speed - (delta_v / 10);
00409         }
00410 
00411         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00412         max_speed = min(max_speed, st_max_speed);
00413       }
00414     }
00415   }
00416 
00417   for (const Train *u = this; u != NULL; u = u->Next()) {
00418     if (u->track == TRACK_BIT_DEPOT) {
00419       max_speed = min(max_speed, 61);
00420       break;
00421     }
00422   }
00423 
00424   return min(max_speed, this->gcache.cached_max_track_speed);
00425 }
00426 
00427 void Train::UpdateAcceleration()
00428 {
00429   assert(this->IsFrontEngine());
00430 
00431   uint power = this->gcache.cached_power;
00432   uint weight = this->gcache.cached_weight;
00433   assert(weight != 0);
00434   this->acceleration = Clamp(power / weight * 4, 1, 255);
00435 }
00436 
00442 int Train::GetDisplayImageWidth(Point *offset) const
00443 {
00444   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00445   int vehicle_pitch = 0;
00446 
00447   const Engine *e = this->GetEngine();
00448   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00449     reference_width = e->GetGRF()->traininfo_vehicle_width;
00450     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00451   }
00452 
00453   if (offset != NULL) {
00454     offset->x = reference_width / 2;
00455     offset->y = vehicle_pitch;
00456   }
00457   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00458 }
00459 
00460 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00461 {
00462   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00463 }
00464 
00465 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00466 {
00467   uint8 spritenum = this->spritenum;
00468   SpriteID sprite;
00469 
00470   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00471 
00472   if (is_custom_sprite(spritenum)) {
00473     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00474     if (sprite != 0) return sprite;
00475 
00476     spritenum = this->GetEngine()->original_image_index;
00477   }
00478 
00479   sprite = GetDefaultTrainSprite(spritenum, direction);
00480 
00481   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00482 
00483   return sprite;
00484 }
00485 
00486 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00487 {
00488   const Engine *e = Engine::Get(engine);
00489   Direction dir = rear_head ? DIR_E : DIR_W;
00490   uint8 spritenum = e->u.rail.image_index;
00491 
00492   if (is_custom_sprite(spritenum)) {
00493     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00494     if (sprite != 0) {
00495       if (e->GetGRF() != NULL) {
00496         y += e->GetGRF()->traininfo_vehicle_pitch;
00497       }
00498       return sprite;
00499     }
00500 
00501     spritenum = Engine::Get(engine)->original_image_index;
00502   }
00503 
00504   if (rear_head) spritenum++;
00505 
00506   return GetDefaultTrainSprite(spritenum, DIR_W);
00507 }
00508 
00509 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00510 {
00511   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00512     int yf = y;
00513     int yr = y;
00514 
00515     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00516     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00517     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00518     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00519 
00520     preferred_x = Clamp(preferred_x, left - UnScaleByZoom(real_spritef->x_offs, ZOOM_LVL_GUI) + 14, right - UnScaleByZoom(real_spriter->width, ZOOM_LVL_GUI) - UnScaleByZoom(real_spriter->x_offs, ZOOM_LVL_GUI) - 15);
00521 
00522     DrawSprite(spritef, pal, preferred_x - 14, yf);
00523     DrawSprite(spriter, pal, preferred_x + 15, yr);
00524   } else {
00525     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00526     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00527     preferred_x = Clamp(preferred_x, left - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI), right - UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI));
00528     DrawSprite(sprite, pal, preferred_x, y);
00529   }
00530 }
00531 
00540 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00541 {
00542   const RailVehicleInfo *rvi = &e->u.rail;
00543 
00544   /* Check that the wagon can drive on the track in question */
00545   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00546 
00547   if (flags & DC_EXEC) {
00548     Train *v = new Train();
00549     *ret = v;
00550     v->spritenum = rvi->image_index;
00551 
00552     v->engine_type = e->index;
00553     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00554 
00555     DiagDirection dir = GetRailDepotDirection(tile);
00556 
00557     v->direction = DiagDirToDir(dir);
00558     v->tile = tile;
00559 
00560     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00561     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00562 
00563     v->x_pos = x;
00564     v->y_pos = y;
00565     v->z_pos = GetSlopePixelZ(x, y);
00566     v->owner = _current_company;
00567     v->track = TRACK_BIT_DEPOT;
00568     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00569 
00570     v->SetWagon();
00571 
00572     v->SetFreeWagon();
00573     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00574 
00575     v->cargo_type = e->GetDefaultCargoType();
00576     v->cargo_cap = rvi->capacity;
00577 
00578     v->railtype = rvi->railtype;
00579 
00580     v->build_year = _cur_year;
00581     v->cur_image = SPR_IMG_QUERY;
00582     v->random_bits = VehicleRandomBits();
00583 
00584     v->group_id = DEFAULT_GROUP;
00585 
00586     AddArticulatedParts(v);
00587 
00588     _new_vehicle_id = v->index;
00589 
00590     VehicleMove(v, false);
00591     v->First()->ConsistChanged(false);
00592     UpdateTrainGroupID(v->First());
00593 
00594     CheckConsistencyOfArticulatedVehicle(v);
00595 
00596     /* Try to connect the vehicle to one of free chains of wagons. */
00597     Train *w;
00598     FOR_ALL_TRAINS(w) {
00599       if (w->tile == tile &&              
00600           w->IsFreeWagon() &&             
00601           w->engine_type == e->index &&   
00602           w->First() != v &&              
00603           !(w->vehstatus & VS_CRASHED)) { 
00604         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00605         break;
00606       }
00607     }
00608   }
00609 
00610   return CommandCost();
00611 }
00612 
00614 static void NormalizeTrainVehInDepot(const Train *u)
00615 {
00616   const Train *v;
00617   FOR_ALL_TRAINS(v) {
00618     if (v->IsFreeWagon() && v->tile == u->tile &&
00619         v->track == TRACK_BIT_DEPOT) {
00620       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00621           CMD_MOVE_RAIL_VEHICLE).Failed())
00622         break;
00623     }
00624   }
00625 }
00626 
00627 static void AddRearEngineToMultiheadedTrain(Train *v)
00628 {
00629   Train *u = new Train();
00630   v->value >>= 1;
00631   u->value = v->value;
00632   u->direction = v->direction;
00633   u->owner = v->owner;
00634   u->tile = v->tile;
00635   u->x_pos = v->x_pos;
00636   u->y_pos = v->y_pos;
00637   u->z_pos = v->z_pos;
00638   u->track = TRACK_BIT_DEPOT;
00639   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00640   u->spritenum = v->spritenum + 1;
00641   u->cargo_type = v->cargo_type;
00642   u->cargo_subtype = v->cargo_subtype;
00643   u->cargo_cap = v->cargo_cap;
00644   u->railtype = v->railtype;
00645   u->engine_type = v->engine_type;
00646   u->build_year = v->build_year;
00647   u->cur_image = SPR_IMG_QUERY;
00648   u->random_bits = VehicleRandomBits();
00649   v->SetMultiheaded();
00650   u->SetMultiheaded();
00651   v->SetNext(u);
00652   VehicleMove(u, false);
00653 
00654   /* Now we need to link the front and rear engines together */
00655   v->other_multiheaded_part = u;
00656   u->other_multiheaded_part = v;
00657 }
00658 
00668 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00669 {
00670   const RailVehicleInfo *rvi = &e->u.rail;
00671 
00672   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00673 
00674   /* Check if depot and new engine uses the same kind of tracks *
00675    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00676   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00677 
00678   if (flags & DC_EXEC) {
00679     DiagDirection dir = GetRailDepotDirection(tile);
00680     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00681     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00682 
00683     Train *v = new Train();
00684     *ret = v;
00685     v->direction = DiagDirToDir(dir);
00686     v->tile = tile;
00687     v->owner = _current_company;
00688     v->x_pos = x;
00689     v->y_pos = y;
00690     v->z_pos = GetSlopePixelZ(x, y);
00691     v->track = TRACK_BIT_DEPOT;
00692     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00693     v->spritenum = rvi->image_index;
00694     v->cargo_type = e->GetDefaultCargoType();
00695     v->cargo_cap = rvi->capacity;
00696     v->last_station_visited = INVALID_STATION;
00697     v->last_loading_station = INVALID_STATION;
00698 
00699     v->engine_type = e->index;
00700     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00701 
00702     v->reliability = e->reliability;
00703     v->reliability_spd_dec = e->reliability_spd_dec;
00704     v->max_age = e->GetLifeLengthInDays();
00705 
00706     v->railtype = rvi->railtype;
00707     _new_vehicle_id = v->index;
00708 
00709     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00710     v->date_of_last_service = _date;
00711     v->build_year = _cur_year;
00712     v->cur_image = SPR_IMG_QUERY;
00713     v->random_bits = VehicleRandomBits();
00714 
00715     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00716 
00717     v->group_id = DEFAULT_GROUP;
00718 
00719     v->SetFrontEngine();
00720     v->SetEngine();
00721 
00722     VehicleMove(v, false);
00723 
00724     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00725       AddRearEngineToMultiheadedTrain(v);
00726     } else {
00727       AddArticulatedParts(v);
00728     }
00729 
00730     v->ConsistChanged(false);
00731     UpdateTrainGroupID(v);
00732 
00733     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00734       NormalizeTrainVehInDepot(v);
00735     }
00736 
00737     CheckConsistencyOfArticulatedVehicle(v);
00738   }
00739 
00740   return CommandCost();
00741 }
00742 
00743 
00744 bool Train::IsInDepot() const
00745 {
00746   /* Is the front engine stationary in the depot? */
00747   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00748 
00749   /* Check whether the rest is also already trying to enter the depot. */
00750   for (const Train *v = this; v != NULL; v = v->Next()) {
00751     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00752   }
00753 
00754   return true;
00755 }
00756 
00757 bool Train::IsStoppedInDepot() const
00758 {
00759   /* Are we stopped? Of course wagons don't really care... */
00760   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00761   return this->IsInDepot();
00762 }
00763 
00764 static Train *FindGoodVehiclePos(const Train *src)
00765 {
00766   EngineID eng = src->engine_type;
00767   TileIndex tile = src->tile;
00768 
00769   Train *dst;
00770   FOR_ALL_TRAINS(dst) {
00771     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00772       /* check so all vehicles in the line have the same engine. */
00773       Train *t = dst;
00774       while (t->engine_type == eng) {
00775         t = t->Next();
00776         if (t == NULL) return dst;
00777       }
00778     }
00779   }
00780 
00781   return NULL;
00782 }
00783 
00785 typedef SmallVector<Train *, 16> TrainList;
00786 
00792 static void MakeTrainBackup(TrainList &list, Train *t)
00793 {
00794   for (; t != NULL; t = t->Next()) *list.Append() = t;
00795 }
00796 
00801 static void RestoreTrainBackup(TrainList &list)
00802 {
00803   /* No train, nothing to do. */
00804   if (list.Length() == 0) return;
00805 
00806   Train *prev = NULL;
00807   /* Iterate over the list and rebuild it. */
00808   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00809     Train *t = *iter;
00810     if (prev != NULL) {
00811       prev->SetNext(t);
00812     } else if (t->Previous() != NULL) {
00813       /* Make sure the head of the train is always the first in the chain. */
00814       t->Previous()->SetNext(NULL);
00815     }
00816     prev = t;
00817   }
00818 }
00819 
00825 static void RemoveFromConsist(Train *part, bool chain = false)
00826 {
00827   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00828 
00829   /* Unlink at the front, but make it point to the next
00830    * vehicle after the to be remove part. */
00831   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00832 
00833   /* Unlink at the back */
00834   tail->SetNext(NULL);
00835 }
00836 
00842 static void InsertInConsist(Train *dst, Train *chain)
00843 {
00844   /* We do not want to add something in the middle of an articulated part. */
00845   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00846 
00847   chain->Last()->SetNext(dst->Next());
00848   dst->SetNext(chain);
00849 }
00850 
00856 static void NormaliseDualHeads(Train *t)
00857 {
00858   for (; t != NULL; t = t->GetNextVehicle()) {
00859     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00860 
00861     /* Make sure that there are no free cars before next engine */
00862     Train *u;
00863     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00864 
00865     if (u == t->other_multiheaded_part) continue;
00866 
00867     /* Remove the part from the 'wrong' train */
00868     RemoveFromConsist(t->other_multiheaded_part);
00869     /* And add it to the 'right' train */
00870     InsertInConsist(u, t->other_multiheaded_part);
00871   }
00872 }
00873 
00878 static void NormaliseSubtypes(Train *chain)
00879 {
00880   /* Nothing to do */
00881   if (chain == NULL) return;
00882 
00883   /* We must be the first in the chain. */
00884   assert(chain->Previous() == NULL);
00885 
00886   /* Set the appropriate bits for the first in the chain. */
00887   if (chain->IsWagon()) {
00888     chain->SetFreeWagon();
00889   } else {
00890     assert(chain->IsEngine());
00891     chain->SetFrontEngine();
00892   }
00893 
00894   /* Now clear the bits for the rest of the chain */
00895   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00896     t->ClearFreeWagon();
00897     t->ClearFrontEngine();
00898   }
00899 }
00900 
00910 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00911 {
00912   /* Just add 'new' engines and subtract the original ones.
00913    * If that's less than or equal to 0 we can be sure we did
00914    * not add any engines (read: trains) along the way. */
00915   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00916       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00917       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00918       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00919     return CommandCost();
00920   }
00921 
00922   /* Get a free unit number and check whether it's within the bounds.
00923    * There will always be a maximum of one new train. */
00924   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00925 
00926   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00927 }
00928 
00934 static CommandCost CheckTrainAttachment(Train *t)
00935 {
00936   /* No multi-part train, no need to check. */
00937   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00938 
00939   /* The maximum length for a train. For each part we decrease this by one
00940    * and if the result is negative the train is simply too long. */
00941   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00942 
00943   Train *head = t;
00944   Train *prev = t;
00945 
00946   /* Break the prev -> t link so it always holds within the loop. */
00947   t = t->Next();
00948   prev->SetNext(NULL);
00949 
00950   /* Make sure the cache is cleared. */
00951   head->InvalidateNewGRFCache();
00952 
00953   while (t != NULL) {
00954     allowed_len -= t->gcache.cached_veh_length;
00955 
00956     Train *next = t->Next();
00957 
00958     /* Unlink the to-be-added piece; it is already unlinked from the previous
00959      * part due to the fact that the prev -> t link is broken. */
00960     t->SetNext(NULL);
00961 
00962     /* Don't check callback for articulated or rear dual headed parts */
00963     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00964       /* Back up and clear the first_engine data to avoid using wagon override group */
00965       EngineID first_engine = t->gcache.first_engine;
00966       t->gcache.first_engine = INVALID_ENGINE;
00967 
00968       /* We don't want the cache to interfere. head's cache is cleared before
00969        * the loop and after each callback does not need to be cleared here. */
00970       t->InvalidateNewGRFCache();
00971 
00972       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00973 
00974       /* Restore original first_engine data */
00975       t->gcache.first_engine = first_engine;
00976 
00977       /* We do not want to remember any cached variables from the test run */
00978       t->InvalidateNewGRFCache();
00979       head->InvalidateNewGRFCache();
00980 
00981       if (callback != CALLBACK_FAILED) {
00982         /* A failing callback means everything is okay */
00983         StringID error = STR_NULL;
00984 
00985         if (t->GetGRF()->grf_version < 8) {
00986           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00987           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00988           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00989         } else {
00990           if (callback < 0x400) {
00991             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00992           } else {
00993             switch (callback) {
00994               case 0x400: // allow if railtypes match (always the case for OpenTTD)
00995               case 0x401: // allow
00996                 break;
00997 
00998               default:    // unknown reason -> disallow
00999               case 0x402: // disallow attaching
01000                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01001                 break;
01002             }
01003           }
01004         }
01005 
01006         if (error != STR_NULL) return_cmd_error(error);
01007       }
01008     }
01009 
01010     /* And link it to the new part. */
01011     prev->SetNext(t);
01012     prev = t;
01013     t = next;
01014   }
01015 
01016   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01017   return CommandCost();
01018 }
01019 
01030 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01031 {
01032   /* Check whether we may actually construct the trains. */
01033   CommandCost ret = CheckTrainAttachment(src);
01034   if (ret.Failed()) return ret;
01035   ret = CheckTrainAttachment(dst);
01036   if (ret.Failed()) return ret;
01037 
01038   /* Check whether we need to build a new train. */
01039   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01040 }
01041 
01050 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01051 {
01052   /* First determine the front of the two resulting trains */
01053   if (*src_head == *dst_head) {
01054     /* If we aren't moving part(s) to a new train, we are just moving the
01055      * front back and there is not destination head. */
01056     *dst_head = NULL;
01057   } else if (*dst_head == NULL) {
01058     /* If we are moving to a new train the head of the move train would become
01059      * the head of the new vehicle. */
01060     *dst_head = src;
01061   }
01062 
01063   if (src == *src_head) {
01064     /* If we are moving the front of a train then we are, in effect, creating
01065      * a new head for the train. Point to that. Unless we are moving the whole
01066      * train in which case there is not 'source' train anymore.
01067      * In case we are a multiheaded part we want the complete thing to come
01068      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01069      * that is followed by a rear multihead we do not want to include that. */
01070     *src_head = move_chain ? NULL :
01071         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01072   }
01073 
01074   /* Now it's just simply removing the part that we are going to move from the
01075    * source train and *if* the destination is a not a new train add the chain
01076    * at the destination location. */
01077   RemoveFromConsist(src, move_chain);
01078   if (*dst_head != src) InsertInConsist(dst, src);
01079 
01080   /* Now normalise the dual heads, that is move the dual heads around in such
01081    * a way that the head and rear of a dual head are in the same train */
01082   NormaliseDualHeads(*src_head);
01083   NormaliseDualHeads(*dst_head);
01084 }
01085 
01091 static void NormaliseTrainHead(Train *head)
01092 {
01093   /* Not much to do! */
01094   if (head == NULL) return;
01095 
01096   /* Tell the 'world' the train changed. */
01097   head->ConsistChanged(false);
01098   UpdateTrainGroupID(head);
01099 
01100   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01101   if (!head->IsFrontEngine()) return;
01102 
01103   /* Update the refit button and window */
01104   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01105   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, VVW_WIDGET_REFIT_VEH);
01106 
01107   /* If we don't have a unit number yet, set one. */
01108   if (head->unitnumber != 0) return;
01109   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01110 }
01111 
01124 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01125 {
01126   VehicleID s = GB(p1, 0, 20);
01127   VehicleID d = GB(p2, 0, 20);
01128   bool move_chain = HasBit(p1, 20);
01129 
01130   Train *src = Train::GetIfValid(s);
01131   if (src == NULL) return CMD_ERROR;
01132 
01133   CommandCost ret = CheckOwnership(src->owner);
01134   if (ret.Failed()) return ret;
01135 
01136   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01137   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01138 
01139   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01140   Train *dst;
01141   if (d == INVALID_VEHICLE) {
01142     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01143   } else {
01144     dst = Train::GetIfValid(d);
01145     if (dst == NULL) return CMD_ERROR;
01146 
01147     CommandCost ret = CheckOwnership(dst->owner);
01148     if (ret.Failed()) return ret;
01149 
01150     /* Do not allow appending to crashed vehicles, too */
01151     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01152   }
01153 
01154   /* if an articulated part is being handled, deal with its parent vehicle */
01155   src = src->GetFirstEnginePart();
01156   if (dst != NULL) {
01157     dst = dst->GetFirstEnginePart();
01158   }
01159 
01160   /* don't move the same vehicle.. */
01161   if (src == dst) return CommandCost();
01162 
01163   /* locate the head of the two chains */
01164   Train *src_head = src->First();
01165   Train *dst_head;
01166   if (dst != NULL) {
01167     dst_head = dst->First();
01168     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01169     /* Now deal with articulated part of destination wagon */
01170     dst = dst->GetLastEnginePart();
01171   } else {
01172     dst_head = NULL;
01173   }
01174 
01175   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01176 
01177   /* When moving all wagons, we can't have the same src_head and dst_head */
01178   if (move_chain && src_head == dst_head) return CommandCost();
01179 
01180   /* When moving a multiheaded part to be place after itself, bail out. */
01181   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01182 
01183   /* Check if all vehicles in the source train are stopped inside a depot. */
01184   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01185 
01186   /* Check if all vehicles in the destination train are stopped inside a depot. */
01187   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01188 
01189   /* First make a backup of the order of the trains. That way we can do
01190    * whatever we want with the order and later on easily revert. */
01191   TrainList original_src;
01192   TrainList original_dst;
01193 
01194   MakeTrainBackup(original_src, src_head);
01195   MakeTrainBackup(original_dst, dst_head);
01196 
01197   /* Also make backup of the original heads as ArrangeTrains can change them.
01198    * For the destination head we do not care if it is the same as the source
01199    * head because in that case it's just a copy. */
01200   Train *original_src_head = src_head;
01201   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01202 
01203   if (flags & DC_EXEC) {
01204     /* Remove old heads from the statistics */
01205     if (original_src_head != NULL && original_src_head->IsFrontEngine()) GroupStatistics::CountVehicle(original_src_head, -1);
01206     if (original_dst_head != NULL && original_dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(original_dst_head, -1);
01207   }
01208 
01209   /* (Re)arrange the trains in the wanted arrangement. */
01210   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01211 
01212   if ((flags & DC_AUTOREPLACE) == 0) {
01213     /* If the autoreplace flag is set we do not need to test for the validity
01214      * because we are going to revert the train to its original state. As we
01215      * assume the original state was correct autoreplace can skip this. */
01216     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01217     if (ret.Failed()) {
01218       /* Restore the train we had. */
01219       RestoreTrainBackup(original_src);
01220       RestoreTrainBackup(original_dst);
01221       return ret;
01222     }
01223   }
01224 
01225   /* do it? */
01226   if (flags & DC_EXEC) {
01227     /* First normalise the sub types of the chains. */
01228     NormaliseSubtypes(src_head);
01229     NormaliseSubtypes(dst_head);
01230 
01231     /* There are 14 different cases:
01232      *  1) front engine gets moved to a new train, it stays a front engine.
01233      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01234      *     b) the 'next' part is an engine that becomes a front engine.
01235      *     c) there is no 'next' part, nothing else happens
01236      *  2) front engine gets moved to another train, it is not a front engine anymore
01237      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01238      *     b) the 'next' part is an engine that becomes a front engine.
01239      *     c) there is no 'next' part, nothing else happens
01240      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01241      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01242      *     b) the 'next' part is an engine that becomes a front engine.
01243      *  4) free wagon gets moved
01244      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01245      *     b) the 'next' part is an engine that becomes a front engine.
01246      *     c) there is no 'next' part, nothing else happens
01247      *  5) non front engine gets moved and becomes a new train, nothing else happens
01248      *  6) non front engine gets moved within a train / to another train, nothing hapens
01249      *  7) wagon gets moved, nothing happens
01250      */
01251     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01252       /* Cases #2 and #3: the front engine gets trashed. */
01253       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01254       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01255       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01256       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01257       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01258 
01259       /* Delete orders, group stuff and the unit number as we're not the
01260        * front of any vehicle anymore. */
01261       DeleteVehicleOrders(src);
01262       RemoveVehicleFromGroup(src);
01263       src->unitnumber = 0;
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     /* Add new heads to statistics */
01273     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01274     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01275 
01276     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01277     NormaliseTrainHead(src_head);
01278     NormaliseTrainHead(dst_head);
01279 
01280     /* We are undoubtedly changing something in the depot and train list. */
01281     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01282     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01283   } else {
01284     /* We don't want to execute what we're just tried. */
01285     RestoreTrainBackup(original_src);
01286     RestoreTrainBackup(original_dst);
01287   }
01288 
01289   return CommandCost();
01290 }
01291 
01303 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01304 {
01305   /* Check if we deleted a vehicle window */
01306   Window *w = NULL;
01307 
01308   /* Sell a chain of vehicles or not? */
01309   bool sell_chain = HasBit(data, 0);
01310 
01311   Train *v = Train::From(t)->GetFirstEnginePart();
01312   Train *first = v->First();
01313 
01314   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01315 
01316   /* First make a backup of the order of the train. That way we can do
01317    * whatever we want with the order and later on easily revert. */
01318   TrainList original;
01319   MakeTrainBackup(original, first);
01320 
01321   /* We need to keep track of the new head and the head of what we're going to sell. */
01322   Train *new_head = first;
01323   Train *sell_head = NULL;
01324 
01325   /* Split the train in the wanted way. */
01326   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01327 
01328   /* We don't need to validate the second train; it's going to be sold. */
01329   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01330   if (ret.Failed()) {
01331     /* Restore the train we had. */
01332     RestoreTrainBackup(original);
01333     return ret;
01334   }
01335 
01336   CommandCost cost(EXPENSES_NEW_VEHICLES);
01337   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01338 
01339   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01340     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01341   }
01342 
01343   /* do it? */
01344   if (flags & DC_EXEC) {
01345     /* First normalise the sub types of the chain. */
01346     NormaliseSubtypes(new_head);
01347 
01348     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01349       /* We are selling the front engine. In this case we want to
01350        * 'give' the order, unit number and such to the new head. */
01351       new_head->orders.list = first->orders.list;
01352       new_head->AddToShared(first);
01353       DeleteVehicleOrders(first);
01354 
01355       /* Copy other important data from the front engine */
01356       new_head->CopyVehicleConfigAndStatistics(first);
01357       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01358 
01359       /* If we deleted a window then open a new one for the 'new' train */
01360       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01361     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01362       OrderBackup::Backup(v, user);
01363     }
01364 
01365     /* We need to update the information about the train. */
01366     NormaliseTrainHead(new_head);
01367 
01368     /* We are undoubtedly changing something in the depot and train list. */
01369     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01370     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01371 
01372     /* Actually delete the sold 'goods' */
01373     delete sell_head;
01374   } else {
01375     /* We don't want to execute what we're just tried. */
01376     RestoreTrainBackup(original);
01377   }
01378 
01379   return cost;
01380 }
01381 
01382 void Train::UpdateDeltaXY(Direction direction)
01383 {
01384   /* Set common defaults. */
01385   this->x_offs    = -1;
01386   this->y_offs    = -1;
01387   this->x_extent  =  3;
01388   this->y_extent  =  3;
01389   this->z_extent  =  6;
01390   this->x_bb_offs =  0;
01391   this->y_bb_offs =  0;
01392 
01393   if (!IsDiagonalDirection(direction)) {
01394     static const int _sign_table[] =
01395     {
01396       // x, y
01397       -1, -1, // DIR_N
01398       -1,  1, // DIR_E
01399        1,  1, // DIR_S
01400        1, -1, // DIR_W
01401     };
01402 
01403     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01404 
01405     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01406     this->x_offs -= half_shorten * _sign_table[direction];
01407     this->y_offs -= half_shorten * _sign_table[direction + 1];
01408     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01409     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01410   } else {
01411     switch (direction) {
01412         /* Shorten southern corner of the bounding box according the vehicle length
01413          * and center the bounding box on the vehicle. */
01414       case DIR_NE:
01415         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01416         this->x_extent  = this->gcache.cached_veh_length - 1;
01417         this->x_bb_offs = -1;
01418         break;
01419 
01420       case DIR_NW:
01421         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01422         this->y_extent  = this->gcache.cached_veh_length - 1;
01423         this->y_bb_offs = -1;
01424         break;
01425 
01426         /* Move northern corner of the bounding box down according to vehicle length
01427          * and center the bounding box on the vehicle. */
01428       case DIR_SW:
01429         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01430         this->x_extent  = VEHICLE_LENGTH - 1;
01431         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01432         break;
01433 
01434       case DIR_SE:
01435         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01436         this->y_extent  = VEHICLE_LENGTH - 1;
01437         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01438         break;
01439 
01440       default:
01441         NOT_REACHED();
01442     }
01443   }
01444 }
01445 
01447 static void MarkTrainAsStuck(Train *v)
01448 {
01449   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01450     /* It is the first time the problem occurred, set the "train stuck" flag. */
01451     SetBit(v->flags, VRF_TRAIN_STUCK);
01452 
01453     v->wait_counter = 0;
01454 
01455     /* Stop train */
01456     v->cur_speed = 0;
01457     v->subspeed = 0;
01458     v->SetLastSpeed();
01459 
01460     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01461   }
01462 }
01463 
01464 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01465 {
01466   uint16 flag1 = *swap_flag1;
01467   uint16 flag2 = *swap_flag2;
01468 
01469   /* Clear the flags */
01470   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01471   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01472   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01473   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01474 
01475   /* Reverse the rail-flags (if needed) */
01476   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01477     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01478   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01479     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01480   }
01481   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01482     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01483   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01484     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01485   }
01486 }
01487 
01492 static void UpdateStatusAfterSwap(Train *v)
01493 {
01494   /* Reverse the direction. */
01495   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01496 
01497   /* Call the proper EnterTile function unless we are in a wormhole. */
01498   if (v->track != TRACK_BIT_WORMHOLE) {
01499     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01500   } else {
01501     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01502      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01503      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01504      * when we shouldn't have. Check if this is the case. */
01505     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01506     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01507       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01508       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01509         /* We have just left the wormhole, possibly set the
01510          * "goingdown" bit. UpdateInclination() can be used
01511          * because we are at the border of the tile. */
01512         v->UpdateInclination(true, true);
01513         return;
01514       }
01515     }
01516   }
01517 
01518   v->UpdateViewport(true, true);
01519 }
01520 
01521 void ReverseTrainSwapVeh(Train *v, int l, int r)
01522 {
01523   Train *a, *b;
01524 
01525   /* locate vehicles to swap */
01526   for (a = v; l != 0; l--) a = a->Next();
01527   for (b = v; r != 0; r--) b = b->Next();
01528 
01529   if (a != b) {
01530     /* swap the hidden bits */
01531     {
01532       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01533       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01534       a->vehstatus = tmp;
01535     }
01536 
01537     Swap(a->track, b->track);
01538     Swap(a->direction, b->direction);
01539     Swap(a->x_pos, b->x_pos);
01540     Swap(a->y_pos, b->y_pos);
01541     Swap(a->tile,  b->tile);
01542     Swap(a->z_pos, b->z_pos);
01543 
01544     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01545 
01546     UpdateStatusAfterSwap(a);
01547     UpdateStatusAfterSwap(b);
01548   } else {
01549     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01550      * This is a little bit redundant way, a->gv_flags will
01551      * be (re)set twice, but it reduces code duplication */
01552     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01553     UpdateStatusAfterSwap(a);
01554   }
01555 
01556   /* Update power of the train in case tiles were different rail type. */
01557   v->RailtypeChanged();
01558 }
01559 
01560 
01566 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01567 {
01568   return (v->type == VEH_TRAIN) ? v : NULL;
01569 }
01570 
01571 
01578 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01579 {
01580   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01581 
01582   Train *t = Train::From(v);
01583   if (!t->IsFrontEngine()) return NULL;
01584 
01585   TileIndex tile = *(TileIndex *)data;
01586 
01587   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01588 
01589   return t;
01590 }
01591 
01592 
01599 static bool TrainApproachingCrossing(TileIndex tile)
01600 {
01601   assert(IsLevelCrossingTile(tile));
01602 
01603   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01604   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01605 
01606   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01607 
01608   dir = ReverseDiagDir(dir);
01609   tile_from = tile + TileOffsByDiagDir(dir);
01610 
01611   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01612 }
01613 
01614 
01621 void UpdateLevelCrossing(TileIndex tile, bool sound)
01622 {
01623   assert(IsLevelCrossingTile(tile));
01624 
01625   /* train on crossing || train approaching crossing || reserved */
01626   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01627 
01628   if (new_state != IsCrossingBarred(tile)) {
01629     if (new_state && sound) {
01630       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01631     }
01632     SetCrossingBarred(tile, new_state);
01633     MarkTileDirtyByTile(tile);
01634   }
01635 }
01636 
01637 
01643 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01644 {
01645   if (!IsCrossingBarred(tile)) {
01646     BarCrossing(tile);
01647     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01648     MarkTileDirtyByTile(tile);
01649   }
01650 }
01651 
01652 
01658 static void AdvanceWagonsBeforeSwap(Train *v)
01659 {
01660   Train *base = v;
01661   Train *first = base; // first vehicle to move
01662   Train *last = v->Last(); // last vehicle to move
01663   uint length = CountVehiclesInChain(v);
01664 
01665   while (length > 2) {
01666     last = last->Previous();
01667     first = first->Next();
01668 
01669     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01670 
01671     /* do not update images now
01672      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01673     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01674 
01675     base = first; // == base->Next()
01676     length -= 2;
01677   }
01678 }
01679 
01680 
01686 static void AdvanceWagonsAfterSwap(Train *v)
01687 {
01688   /* first of all, fix the situation when the train was entering a depot */
01689   Train *dep = v; // last vehicle in front of just left depot
01690   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01691     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01692   }
01693 
01694   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01695 
01696   if (leave != NULL) {
01697     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01698     int d = TicksToLeaveDepot(dep);
01699 
01700     if (d <= 0) {
01701       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01702       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01703       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01704     }
01705   } else {
01706     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01707   }
01708 
01709   Train *base = v;
01710   Train *first = base; // first vehicle to move
01711   Train *last = v->Last(); // last vehicle to move
01712   uint length = CountVehiclesInChain(v);
01713 
01714   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01715    * they have already correct spacing, so we have to make sure they are moved how they should */
01716   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01717 
01718   while (length > 2) {
01719     /* we reached vehicle (originally) in front of a depot, stop now
01720      * (we would move wagons that are already moved with new wagon length). */
01721     if (base == dep) break;
01722 
01723     /* the last wagon was that one leaving a depot, so do not move it anymore */
01724     if (last == dep) nomove = true;
01725 
01726     last = last->Previous();
01727     first = first->Next();
01728 
01729     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01730 
01731     /* do not update images now */
01732     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01733 
01734     base = first; // == base->Next()
01735     length -= 2;
01736   }
01737 }
01738 
01739 
01740 void ReverseTrainDirection(Train *v)
01741 {
01742   if (IsRailDepotTile(v->tile)) {
01743     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01744   }
01745 
01746   /* Clear path reservation in front if train is not stuck. */
01747   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01748 
01749   /* Check if we were approaching a rail/road-crossing */
01750   TileIndex crossing = TrainApproachingCrossingTile(v);
01751 
01752   /* count number of vehicles */
01753   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01754 
01755   AdvanceWagonsBeforeSwap(v);
01756 
01757   /* swap start<>end, start+1<>end-1, ... */
01758   int l = 0;
01759   do {
01760     ReverseTrainSwapVeh(v, l++, r--);
01761   } while (l <= r);
01762 
01763   AdvanceWagonsAfterSwap(v);
01764 
01765   if (IsRailDepotTile(v->tile)) {
01766     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01767   }
01768 
01769   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01770 
01771   ClrBit(v->flags, VRF_REVERSING);
01772 
01773   /* recalculate cached data */
01774   v->ConsistChanged(true);
01775 
01776   /* update all images */
01777   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01778 
01779   /* update crossing we were approaching */
01780   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01781 
01782   /* maybe we are approaching crossing now, after reversal */
01783   crossing = TrainApproachingCrossingTile(v);
01784   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01785 
01786   /* If we are inside a depot after reversing, don't bother with path reserving. */
01787   if (v->track == TRACK_BIT_DEPOT) {
01788     /* Can't be stuck here as inside a depot is always a safe tile. */
01789     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01790     ClrBit(v->flags, VRF_TRAIN_STUCK);
01791     return;
01792   }
01793 
01794   /* TrainExitDir does not always produce the desired dir for depots and
01795    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01796   DiagDirection dir = TrainExitDir(v->direction, v->track);
01797   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01798 
01799   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01800     /* If we are currently on a tile with conventional signals, we can't treat the
01801      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01802     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01803       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01804       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01805 
01806     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01807     if (TryPathReserve(v, false, first_tile_okay)) {
01808       /* Do a look-ahead now in case our current tile was already a safe tile. */
01809       CheckNextTrainTile(v);
01810     } else if (v->current_order.GetType() != OT_LOADING) {
01811       /* Do not wait for a way out when we're still loading */
01812       MarkTrainAsStuck(v);
01813     }
01814   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01815     /* A train not inside a PBS block can't be stuck. */
01816     ClrBit(v->flags, VRF_TRAIN_STUCK);
01817     v->wait_counter = 0;
01818   }
01819 }
01820 
01830 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01831 {
01832   Train *v = Train::GetIfValid(p1);
01833   if (v == NULL) return CMD_ERROR;
01834 
01835   CommandCost ret = CheckOwnership(v->owner);
01836   if (ret.Failed()) return ret;
01837 
01838   if (p2 != 0) {
01839     /* turn a single unit around */
01840 
01841     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01842       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01843     }
01844     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01845 
01846     Train *front = v->First();
01847     /* make sure the vehicle is stopped in the depot */
01848     if (!front->IsStoppedInDepot()) {
01849       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01850     }
01851 
01852     if (flags & DC_EXEC) {
01853       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01854 
01855       front->ConsistChanged(false);
01856       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01857       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01858       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01859       SetWindowClassesDirty(WC_TRAINS_LIST);
01860     }
01861   } else {
01862     /* turn the whole train around */
01863     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01864 
01865     if (flags & DC_EXEC) {
01866       /* Properly leave the station if we are loading and won't be loading anymore */
01867       if (v->current_order.IsType(OT_LOADING)) {
01868         const Vehicle *last = v;
01869         while (last->Next() != NULL) last = last->Next();
01870 
01871         /* not a station || different station --> leave the station */
01872         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01873           v->LeaveStation();
01874         }
01875       }
01876 
01877       /* We cancel any 'skip signal at dangers' here */
01878       v->force_proceed = TFP_NONE;
01879       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01880 
01881       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01882         ToggleBit(v->flags, VRF_REVERSING);
01883       } else {
01884         v->cur_speed = 0;
01885         v->SetLastSpeed();
01886         HideFillingPercent(&v->fill_percent_te_id);
01887         ReverseTrainDirection(v);
01888       }
01889     }
01890   }
01891   return CommandCost();
01892 }
01893 
01903 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01904 {
01905   Train *t = Train::GetIfValid(p1);
01906   if (t == NULL) return CMD_ERROR;
01907 
01908   CommandCost ret = CheckOwnership(t->owner);
01909   if (ret.Failed()) return ret;
01910 
01911 
01912   if (flags & DC_EXEC) {
01913     /* If we are forced to proceed, cancel that order.
01914      * If we are marked stuck we would want to force the train
01915      * to proceed to the next signal. In the other cases we
01916      * would like to pass the signal at danger and run till the
01917      * next signal we encounter. */
01918     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01919     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01920   }
01921 
01922   return CommandCost();
01923 }
01924 
01929 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01930 {
01931   assert(!(v->vehstatus & VS_CRASHED));
01932 
01933   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01934 
01935   PBSTileInfo origin = FollowTrainReservation(v);
01936   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01937 
01938   switch (_settings_game.pf.pathfinder_for_trains) {
01939     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01940     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01941 
01942     default: NOT_REACHED();
01943   }
01944 }
01945 
01946 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01947 {
01948   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01949   if (tfdd.best_length == UINT_MAX) return false;
01950 
01951   if (location    != NULL) *location    = tfdd.tile;
01952   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01953   if (reverse     != NULL) *reverse     = tfdd.reverse;
01954 
01955   return true;
01956 }
01957 
01958 void Train::PlayLeaveStationSound() const
01959 {
01960   static const SoundFx sfx[] = {
01961     SND_04_TRAIN,
01962     SND_0A_TRAIN_HORN,
01963     SND_0A_TRAIN_HORN,
01964     SND_47_MAGLEV_2,
01965     SND_41_MAGLEV
01966   };
01967 
01968   if (PlayVehicleSound(this, VSE_START)) return;
01969 
01970   EngineID engtype = this->engine_type;
01971   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
01972 }
01973 
01975 static void CheckNextTrainTile(Train *v)
01976 {
01977   /* Don't do any look-ahead if path_backoff_interval is 255. */
01978   if (_settings_game.pf.path_backoff_interval == 255) return;
01979 
01980   /* Exit if we are inside a depot. */
01981   if (v->track == TRACK_BIT_DEPOT) return;
01982 
01983   switch (v->current_order.GetType()) {
01984     /* Exit if we reached our destination depot. */
01985     case OT_GOTO_DEPOT:
01986       if (v->tile == v->dest_tile) return;
01987       break;
01988 
01989     case OT_GOTO_WAYPOINT:
01990       /* If we reached our waypoint, make sure we see that. */
01991       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
01992       break;
01993 
01994     case OT_NOTHING:
01995     case OT_LEAVESTATION:
01996     case OT_LOADING:
01997       /* Exit if the current order doesn't have a destination, but the train has orders. */
01998       if (v->GetNumOrders() > 0) return;
01999       break;
02000 
02001     default:
02002       break;
02003   }
02004   /* Exit if we are on a station tile and are going to stop. */
02005   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02006 
02007   Trackdir td = v->GetVehicleTrackdir();
02008 
02009   /* On a tile with a red non-pbs signal, don't look ahead. */
02010   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02011       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02012       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02013 
02014   CFollowTrackRail ft(v);
02015   if (!ft.Follow(v->tile, td)) return;
02016 
02017   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02018     /* Next tile is not reserved. */
02019     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02020       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02021         /* If the next tile is a PBS signal, try to make a reservation. */
02022         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02023         if (_settings_game.pf.forbid_90_deg) {
02024           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02025         }
02026         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02027       }
02028     }
02029   }
02030 }
02031 
02032 static bool CheckTrainStayInDepot(Train *v)
02033 {
02034   /* bail out if not all wagons are in the same depot or not in a depot at all */
02035   for (const Train *u = v; u != NULL; u = u->Next()) {
02036     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02037   }
02038 
02039   /* if the train got no power, then keep it in the depot */
02040   if (v->gcache.cached_power == 0) {
02041     v->vehstatus |= VS_STOPPED;
02042     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02043     return true;
02044   }
02045 
02046   SigSegState seg_state;
02047 
02048   if (v->force_proceed == TFP_NONE) {
02049     /* force proceed was not pressed */
02050     if (++v->wait_counter < 37) {
02051       SetWindowClassesDirty(WC_TRAINS_LIST);
02052       return true;
02053     }
02054 
02055     v->wait_counter = 0;
02056 
02057     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02058     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02059       /* Full and no PBS signal in block or depot reserved, can't exit. */
02060       SetWindowClassesDirty(WC_TRAINS_LIST);
02061       return true;
02062     }
02063   } else {
02064     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02065   }
02066 
02067   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02068   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02069     /* We need to have a reservation for this to work. */
02070     if (HasDepotReservation(v->tile)) return true;
02071     SetDepotReservation(v->tile, true);
02072     VehicleEnterDepot(v);
02073     return true;
02074   }
02075 
02076   /* Only leave when we can reserve a path to our destination. */
02077   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02078     /* No path and no force proceed. */
02079     SetWindowClassesDirty(WC_TRAINS_LIST);
02080     MarkTrainAsStuck(v);
02081     return true;
02082   }
02083 
02084   SetDepotReservation(v->tile, true);
02085   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02086 
02087   VehicleServiceInDepot(v);
02088   SetWindowClassesDirty(WC_TRAINS_LIST);
02089   v->PlayLeaveStationSound();
02090 
02091   v->track = TRACK_BIT_X;
02092   if (v->direction & 2) v->track = TRACK_BIT_Y;
02093 
02094   v->vehstatus &= ~VS_HIDDEN;
02095   v->cur_speed = 0;
02096 
02097   v->UpdateDeltaXY(v->direction);
02098   v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
02099   VehicleMove(v, false);
02100   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02101   v->UpdateAcceleration();
02102   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02103 
02104   return false;
02105 }
02106 
02108 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02109 {
02110   DiagDirection dir = TrackdirToExitdir(track_dir);
02111 
02112   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02113     /* Are we just leaving a tunnel/bridge? */
02114     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02115       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02116 
02117       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02118         /* Free the reservation only if no other train is on the tiles. */
02119         SetTunnelBridgeReservation(tile, false);
02120         SetTunnelBridgeReservation(end, false);
02121 
02122         if (_settings_client.gui.show_track_reservation) {
02123           MarkTileDirtyByTile(tile);
02124           MarkTileDirtyByTile(end);
02125         }
02126       }
02127     }
02128   } else if (IsRailStationTile(tile)) {
02129     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02130     /* If the new tile is not a further tile of the same station, we
02131      * clear the reservation for the whole platform. */
02132     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02133       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02134     }
02135   } else {
02136     /* Any other tile */
02137     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02138   }
02139 }
02140 
02142 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02143 {
02144   assert(v->IsFrontEngine());
02145 
02146   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02147   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02148   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02149   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02150 
02151   /* Don't free reservation if it's not ours. */
02152   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02153 
02154   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02155   while (ft.Follow(tile, td)) {
02156     tile = ft.m_new_tile;
02157     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02158     td = RemoveFirstTrackdir(&bits);
02159     assert(bits == TRACKDIR_BIT_NONE);
02160 
02161     if (!IsValidTrackdir(td)) break;
02162 
02163     if (IsTileType(tile, MP_RAILWAY)) {
02164       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02165         /* Conventional signal along trackdir: remove reservation and stop. */
02166         UnreserveRailTrack(tile, TrackdirToTrack(td));
02167         break;
02168       }
02169       if (HasPbsSignalOnTrackdir(tile, td)) {
02170         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02171           /* Red PBS signal? Can't be our reservation, would be green then. */
02172           break;
02173         } else {
02174           /* Turn the signal back to red. */
02175           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02176           MarkTileDirtyByTile(tile);
02177         }
02178       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02179         break;
02180       }
02181     }
02182 
02183     /* Don't free first station/bridge/tunnel if we are on it. */
02184     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);
02185 
02186     free_tile = true;
02187   }
02188 }
02189 
02190 static const byte _initial_tile_subcoord[6][4][3] = {
02191 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02192 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02193 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02194 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02195 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02196 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02197 };
02198 
02211 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02212 {
02213   switch (_settings_game.pf.pathfinder_for_trains) {
02214     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02215     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02216 
02217     default: NOT_REACHED();
02218   }
02219 }
02220 
02226 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02227 {
02228   PBSTileInfo origin = FollowTrainReservation(v);
02229 
02230   CFollowTrackRail ft(v);
02231 
02232   TileIndex tile = origin.tile;
02233   Trackdir  cur_td = origin.trackdir;
02234   while (ft.Follow(tile, cur_td)) {
02235     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02236       /* Possible signal tile. */
02237       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02238     }
02239 
02240     if (_settings_game.pf.forbid_90_deg) {
02241       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02242       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02243     }
02244 
02245     /* Station, depot or waypoint are a possible target. */
02246     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02247     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02248       /* Choice found or possible target encountered.
02249        * On finding a possible target, we need to stop and let the pathfinder handle the
02250        * remaining path. This is because we don't know if this target is in one of our
02251        * orders, so we might cause pathfinding to fail later on if we find a choice.
02252        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02253        * a wrong path not leading to our next destination. */
02254       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02255 
02256       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02257        * actually starts its search at the first unreserved tile. */
02258       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02259 
02260       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02261       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02262       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02263       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02264     }
02265 
02266     tile = ft.m_new_tile;
02267     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02268 
02269     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02270       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02271       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02272       /* Safe position is all good, path valid and okay. */
02273       return PBSTileInfo(tile, cur_td, true);
02274     }
02275 
02276     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02277   }
02278 
02279   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02280     /* End of line, path valid and okay. */
02281     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02282   }
02283 
02284   /* Sorry, can't reserve path, back out. */
02285   tile = origin.tile;
02286   cur_td = origin.trackdir;
02287   TileIndex stopped = ft.m_old_tile;
02288   Trackdir  stopped_td = ft.m_old_td;
02289   while (tile != stopped || cur_td != stopped_td) {
02290     if (!ft.Follow(tile, cur_td)) break;
02291 
02292     if (_settings_game.pf.forbid_90_deg) {
02293       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02294       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02295     }
02296     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02297 
02298     tile = ft.m_new_tile;
02299     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02300 
02301     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02302   }
02303 
02304   /* Path invalid. */
02305   return PBSTileInfo();
02306 }
02307 
02318 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02319 {
02320   switch (_settings_game.pf.pathfinder_for_trains) {
02321     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02322     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02323 
02324     default: NOT_REACHED();
02325   }
02326 }
02327 
02329 class VehicleOrderSaver
02330 {
02331 private:
02332   Train          *v;
02333   Order          old_order;
02334   TileIndex      old_dest_tile;
02335   StationID      old_last_station_visited;
02336   VehicleOrderID index;
02337   bool           suppress_implicit_orders;
02338 
02339 public:
02340   VehicleOrderSaver(Train *_v) :
02341     v(_v),
02342     old_order(_v->current_order),
02343     old_dest_tile(_v->dest_tile),
02344     old_last_station_visited(_v->last_station_visited),
02345     index(_v->cur_real_order_index),
02346     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02347   {
02348   }
02349 
02350   ~VehicleOrderSaver()
02351   {
02352     this->v->current_order = this->old_order;
02353     this->v->dest_tile = this->old_dest_tile;
02354     this->v->last_station_visited = this->old_last_station_visited;
02355     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02356   }
02357 
02363   bool SwitchToNextOrder(bool skip_first)
02364   {
02365     if (this->v->GetNumOrders() == 0) return false;
02366 
02367     if (skip_first) ++this->index;
02368 
02369     int conditional_depth = 0;
02370 
02371     do {
02372       /* Wrap around. */
02373       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02374 
02375       Order *order = this->v->GetOrder(this->index);
02376       assert(order != NULL);
02377 
02378       switch (order->GetType()) {
02379         case OT_GOTO_DEPOT:
02380           /* Skip service in depot orders when the train doesn't need service. */
02381           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02382         case OT_GOTO_STATION:
02383         case OT_GOTO_WAYPOINT:
02384           this->v->current_order = *order;
02385           return UpdateOrderDest(this->v, order, 0, true);
02386         case OT_CONDITIONAL: {
02387           if (conditional_depth > this->v->GetNumOrders()) return false;
02388           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02389           if (next != INVALID_VEH_ORDER_ID) {
02390             conditional_depth++;
02391             this->index = next;
02392             /* Don't increment next, so no break here. */
02393             continue;
02394           }
02395           break;
02396         }
02397         default:
02398           break;
02399       }
02400       /* Don't increment inside the while because otherwise conditional
02401        * orders can lead to an infinite loop. */
02402       ++this->index;
02403     } while (this->index != this->v->cur_real_order_index);
02404 
02405     return false;
02406   }
02407 };
02408 
02409 /* choose a track */
02410 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02411 {
02412   Track best_track = INVALID_TRACK;
02413   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02414   bool changed_signal = false;
02415 
02416   assert((tracks & ~TRACK_BIT_MASK) == 0);
02417 
02418   if (got_reservation != NULL) *got_reservation = false;
02419 
02420   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02421   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02422   /* Do we have a suitable reserved track? */
02423   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02424 
02425   /* Quick return in case only one possible track is available */
02426   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02427     Track track = FindFirstTrack(tracks);
02428     /* We need to check for signals only here, as a junction tile can't have signals. */
02429     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02430       do_track_reservation = true;
02431       changed_signal = true;
02432       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02433     } else if (!do_track_reservation) {
02434       return track;
02435     }
02436     best_track = track;
02437   }
02438 
02439   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02440   DiagDirection dest_enterdir = enterdir;
02441   if (do_track_reservation) {
02442     /* Check if the train needs service here, so it has a chance to always find a depot.
02443      * Also check if the current order is a service order so we don't reserve a path to
02444      * the destination but instead to the next one if service isn't needed. */
02445     CheckIfTrainNeedsService(v);
02446     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02447 
02448     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02449     if (res_dest.tile == INVALID_TILE) {
02450       /* Reservation failed? */
02451       if (mark_stuck) MarkTrainAsStuck(v);
02452       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02453       return FindFirstTrack(tracks);
02454     }
02455   }
02456 
02457   /* Save the current train order. The destructor will restore the old order on function exit. */
02458   VehicleOrderSaver orders(v);
02459 
02460   /* If the current tile is the destination of the current order and
02461    * a reservation was requested, advance to the next order.
02462    * Don't advance on a depot order as depots are always safe end points
02463    * for a path and no look-ahead is necessary. This also avoids a
02464    * problem with depot orders not part of the order list when the
02465    * order list itself is empty. */
02466   if (v->current_order.IsType(OT_LEAVESTATION)) {
02467     orders.SwitchToNextOrder(false);
02468   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02469       v->current_order.IsType(OT_GOTO_STATION) ?
02470       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02471       v->tile == v->dest_tile))) {
02472     orders.SwitchToNextOrder(true);
02473   }
02474 
02475   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02476     /* Pathfinders are able to tell that route was only 'guessed'. */
02477     bool      path_found = true;
02478     TileIndex new_tile = res_dest.tile;
02479 
02480     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02481     if (new_tile == tile) best_track = next_track;
02482     v->HandlePathfindingResult(path_found);
02483   }
02484 
02485   /* No track reservation requested -> finished. */
02486   if (!do_track_reservation) return best_track;
02487 
02488   /* A path was found, but could not be reserved. */
02489   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02490     if (mark_stuck) MarkTrainAsStuck(v);
02491     FreeTrainTrackReservation(v);
02492     return best_track;
02493   }
02494 
02495   /* No possible reservation target found, we are probably lost. */
02496   if (res_dest.tile == INVALID_TILE) {
02497     /* Try to find any safe destination. */
02498     PBSTileInfo origin = FollowTrainReservation(v);
02499     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02500       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02501       best_track = FindFirstTrack(res);
02502       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02503       if (got_reservation != NULL) *got_reservation = true;
02504       if (changed_signal) MarkTileDirtyByTile(tile);
02505     } else {
02506       FreeTrainTrackReservation(v);
02507       if (mark_stuck) MarkTrainAsStuck(v);
02508     }
02509     return best_track;
02510   }
02511 
02512   if (got_reservation != NULL) *got_reservation = true;
02513 
02514   /* Reservation target found and free, check if it is safe. */
02515   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02516     /* Extend reservation until we have found a safe position. */
02517     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02518     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02519     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02520     if (_settings_game.pf.forbid_90_deg) {
02521       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02522     }
02523 
02524     /* Get next order with destination. */
02525     if (orders.SwitchToNextOrder(true)) {
02526       PBSTileInfo cur_dest;
02527       bool path_found;
02528       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02529       if (cur_dest.tile != INVALID_TILE) {
02530         res_dest = cur_dest;
02531         if (res_dest.okay) continue;
02532         /* Path found, but could not be reserved. */
02533         FreeTrainTrackReservation(v);
02534         if (mark_stuck) MarkTrainAsStuck(v);
02535         if (got_reservation != NULL) *got_reservation = false;
02536         changed_signal = false;
02537         break;
02538       }
02539     }
02540     /* No order or no safe position found, try any position. */
02541     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02542       FreeTrainTrackReservation(v);
02543       if (mark_stuck) MarkTrainAsStuck(v);
02544       if (got_reservation != NULL) *got_reservation = false;
02545       changed_signal = false;
02546     }
02547     break;
02548   }
02549 
02550   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02551 
02552   if (changed_signal) MarkTileDirtyByTile(tile);
02553 
02554   return best_track;
02555 }
02556 
02565 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02566 {
02567   assert(v->IsFrontEngine());
02568 
02569   /* We have to handle depots specially as the track follower won't look
02570    * at the depot tile itself but starts from the next tile. If we are still
02571    * inside the depot, a depot reservation can never be ours. */
02572   if (v->track == TRACK_BIT_DEPOT) {
02573     if (HasDepotReservation(v->tile)) {
02574       if (mark_as_stuck) MarkTrainAsStuck(v);
02575       return false;
02576     } else {
02577       /* Depot not reserved, but the next tile might be. */
02578       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02579       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02580     }
02581   }
02582 
02583   Vehicle *other_train = NULL;
02584   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02585   /* The path we are driving on is already blocked by some other train.
02586    * This can only happen in certain situations when mixing path and
02587    * block signals or when changing tracks and/or signals.
02588    * Exit here as doing any further reservations will probably just
02589    * make matters worse. */
02590   if (other_train != NULL && other_train->index != v->index) {
02591     if (mark_as_stuck) MarkTrainAsStuck(v);
02592     return false;
02593   }
02594   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02595   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02596     /* Can't be stuck then. */
02597     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
02598     ClrBit(v->flags, VRF_TRAIN_STUCK);
02599     return true;
02600   }
02601 
02602   /* If we are in a depot, tentatively reserve the depot. */
02603   if (v->track == TRACK_BIT_DEPOT) {
02604     SetDepotReservation(v->tile, true);
02605     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02606   }
02607 
02608   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02609   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02610   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02611 
02612   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02613 
02614   bool res_made = false;
02615   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02616 
02617   if (!res_made) {
02618     /* Free the depot reservation as well. */
02619     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02620     return false;
02621   }
02622 
02623   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02624     v->wait_counter = 0;
02625     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
02626   }
02627   ClrBit(v->flags, VRF_TRAIN_STUCK);
02628   return true;
02629 }
02630 
02631 
02632 static bool CheckReverseTrain(const Train *v)
02633 {
02634   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02635       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02636       !(v->direction & 1)) {
02637     return false;
02638   }
02639 
02640   assert(v->track != TRACK_BIT_NONE);
02641 
02642   switch (_settings_game.pf.pathfinder_for_trains) {
02643     case VPF_NPF: return NPFTrainCheckReverse(v);
02644     case VPF_YAPF: return YapfTrainCheckReverse(v);
02645 
02646     default: NOT_REACHED();
02647   }
02648 }
02649 
02650 TileIndex Train::GetOrderStationLocation(StationID station)
02651 {
02652   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02653 
02654   const Station *st = Station::Get(station);
02655   if (!(st->facilities & FACIL_TRAIN)) {
02656     /* The destination station has no trainstation tiles. */
02657     this->IncrementRealOrderIndex();
02658     return 0;
02659   }
02660 
02661   return st->xy;
02662 }
02663 
02664 void Train::MarkDirty()
02665 {
02666   Train *v = this;
02667   do {
02668     v->UpdateViewport(false, false);
02669   } while ((v = v->Next()) != NULL);
02670 
02671   /* need to update acceleration and cached values since the goods on the train changed. */
02672   this->CargoChanged();
02673   this->UpdateAcceleration();
02674 }
02675 
02683 int Train::UpdateSpeed()
02684 {
02685   switch (_settings_game.vehicle.train_acceleration_model) {
02686     default: NOT_REACHED();
02687     case AM_ORIGINAL:
02688       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, this->gcache.cached_max_track_speed);
02689 
02690     case AM_REALISTIC:
02691       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02692   }
02693 }
02694 
02700 static void TrainEnterStation(Train *v, StationID station)
02701 {
02702   v->last_station_visited = station;
02703 
02704   /* check if a train ever visited this station before */
02705   Station *st = Station::Get(station);
02706   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02707     st->had_vehicle_of_type |= HVOT_TRAIN;
02708     SetDParam(0, st->index);
02709     AddVehicleNewsItem(
02710       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02711       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
02712       v->index,
02713       st->index
02714     );
02715     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02716   }
02717 
02718   v->force_proceed = TFP_NONE;
02719   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02720 
02721   v->BeginLoading();
02722 
02723   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02724 }
02725 
02726 /* Check if the vehicle is compatible with the specified tile */
02727 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02728 {
02729   return IsTileOwner(tile, v->owner) &&
02730       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02731 }
02732 
02733 struct RailtypeSlowdownParams {
02734   byte small_turn, large_turn;
02735   byte z_up; // fraction to remove when moving up
02736   byte z_down; // fraction to remove when moving down
02737 };
02738 
02739 static const RailtypeSlowdownParams _railtype_slowdown[] = {
02740   /* normal accel */
02741   {256 / 4, 256 / 2, 256 / 4, 2}, 
02742   {256 / 4, 256 / 2, 256 / 4, 2}, 
02743   {256 / 4, 256 / 2, 256 / 4, 2}, 
02744   {0,       256 / 2, 256 / 4, 2}, 
02745 };
02746 
02748 static inline void AffectSpeedByZChange(Train *v, int old_z)
02749 {
02750   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02751 
02752   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
02753 
02754   if (old_z < v->z_pos) {
02755     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
02756   } else {
02757     uint16 spd = v->cur_speed + rsp->z_down;
02758     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02759   }
02760 }
02761 
02762 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02763 {
02764   if (IsTileType(tile, MP_RAILWAY) &&
02765       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02766     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02767     Trackdir trackdir = FindFirstTrackdir(tracks);
02768     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02769       /* A PBS block with a non-PBS signal facing us? */
02770       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02771     }
02772   }
02773   return false;
02774 }
02775 
02779 void Train::ReserveTrackUnderConsist() const
02780 {
02781   for (const Train *u = this; u != NULL; u = u->Next()) {
02782     switch (u->track) {
02783       case TRACK_BIT_WORMHOLE:
02784         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02785         break;
02786       case TRACK_BIT_DEPOT:
02787         break;
02788       default:
02789         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02790         break;
02791     }
02792   }
02793 }
02794 
02795 uint Train::Crash(bool flooded)
02796 {
02797   uint pass = 0;
02798   if (this->IsFrontEngine()) {
02799     pass += 2; // driver
02800 
02801     /* Remove the reserved path in front of the train if it is not stuck.
02802      * Also clear all reserved tracks the train is currently on. */
02803     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02804     for (const Train *v = this; v != NULL; v = v->Next()) {
02805       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02806       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02807         /* ClearPathReservation will not free the wormhole exit
02808          * if the train has just entered the wormhole. */
02809         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02810       }
02811     }
02812 
02813     /* we may need to update crossing we were approaching,
02814      * but must be updated after the train has been marked crashed */
02815     TileIndex crossing = TrainApproachingCrossingTile(this);
02816     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02817 
02818     /* Remove the loading indicators (if any) */
02819     HideFillingPercent(&this->fill_percent_te_id);
02820   }
02821 
02822   pass += this->GroundVehicleBase::Crash(flooded);
02823 
02824   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02825   return pass;
02826 }
02827 
02834 static uint TrainCrashed(Train *v)
02835 {
02836   uint num = 0;
02837 
02838   /* do not crash train twice */
02839   if (!(v->vehstatus & VS_CRASHED)) {
02840     num = v->Crash();
02841     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02842   }
02843 
02844   /* Try to re-reserve track under already crashed train too.
02845    * Crash() clears the reservation! */
02846   v->ReserveTrackUnderConsist();
02847 
02848   return num;
02849 }
02850 
02851 struct TrainCollideChecker {
02852   Train *v; 
02853   uint num; 
02854 };
02855 
02856 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02857 {
02858   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02859 
02860   /* not a train or in depot */
02861   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02862 
02863   /* do not crash into trains of another company. */
02864   if (v->owner != tcc->v->owner) return NULL;
02865 
02866   /* get first vehicle now to make most usual checks faster */
02867   Train *coll = Train::From(v)->First();
02868 
02869   /* can't collide with own wagons */
02870   if (coll == tcc->v) return NULL;
02871 
02872   int x_diff = v->x_pos - tcc->v->x_pos;
02873   int y_diff = v->y_pos - tcc->v->y_pos;
02874 
02875   /* Do fast calculation to check whether trains are not in close vicinity
02876    * and quickly reject trains distant enough for any collision.
02877    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02878    * Differences are then ORed and then we check for any higher bits */
02879   uint hash = (y_diff + 7) | (x_diff + 7);
02880   if (hash & ~15) return NULL;
02881 
02882   /* Slower check using multiplication */
02883   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02884   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02885 
02886   /* Happens when there is a train under bridge next to bridge head */
02887   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02888 
02889   /* crash both trains */
02890   tcc->num += TrainCrashed(tcc->v);
02891   tcc->num += TrainCrashed(coll);
02892 
02893   return NULL; // continue searching
02894 }
02895 
02902 static bool CheckTrainCollision(Train *v)
02903 {
02904   /* can't collide in depot */
02905   if (v->track == TRACK_BIT_DEPOT) return false;
02906 
02907   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
02908 
02909   TrainCollideChecker tcc;
02910   tcc.v = v;
02911   tcc.num = 0;
02912 
02913   /* find colliding vehicles */
02914   if (v->track == TRACK_BIT_WORMHOLE) {
02915     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
02916     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
02917   } else {
02918     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
02919   }
02920 
02921   /* any dead -> no crash */
02922   if (tcc.num == 0) return false;
02923 
02924   SetDParam(0, tcc.num);
02925   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH,
02926     NS_ACCIDENT,
02927     v->index
02928   );
02929 
02930   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
02931   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
02932   return true;
02933 }
02934 
02935 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
02936 {
02937   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
02938 
02939   Train *t = Train::From(v);
02940   DiagDirection exitdir = *(DiagDirection *)data;
02941 
02942   /* not front engine of a train, inside wormhole or depot, crashed */
02943   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
02944 
02945   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
02946 
02947   return t;
02948 }
02949 
02957 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
02958 {
02959   Train *first = v->First();
02960   Train *prev;
02961   bool direction_changed = false; // has direction of any part changed?
02962 
02963   /* For every vehicle after and including the given vehicle */
02964   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
02965     DiagDirection enterdir = DIAGDIR_BEGIN;
02966     bool update_signals_crossing = false; // will we update signals or crossing state?
02967 
02968     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
02969     if (v->track != TRACK_BIT_WORMHOLE) {
02970       /* Not inside tunnel */
02971       if (gp.old_tile == gp.new_tile) {
02972         /* Staying in the old tile */
02973         if (v->track == TRACK_BIT_DEPOT) {
02974           /* Inside depot */
02975           gp.x = v->x_pos;
02976           gp.y = v->y_pos;
02977         } else {
02978           /* Not inside depot */
02979 
02980           /* Reverse when we are at the end of the track already, do not move to the new position */
02981           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
02982 
02983           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
02984           if (HasBit(r, VETS_CANNOT_ENTER)) {
02985             goto invalid_rail;
02986           }
02987           if (HasBit(r, VETS_ENTERED_STATION)) {
02988             /* The new position is the end of the platform */
02989             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
02990           }
02991         }
02992       } else {
02993         /* A new tile is about to be entered. */
02994 
02995         /* Determine what direction we're entering the new tile from */
02996         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
02997         assert(IsValidDiagDirection(enterdir));
02998 
02999         /* Get the status of the tracks in the new tile and mask
03000          * away the bits that aren't reachable. */
03001         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03002         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03003 
03004         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03005         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03006 
03007         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03008         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03009           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03010            * can be switched on halfway a turn */
03011           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03012         }
03013 
03014         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03015 
03016         /* Check if the new tile constrains tracks that are compatible
03017          * with the current train, if not, bail out. */
03018         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03019 
03020         TrackBits chosen_track;
03021         if (prev == NULL) {
03022           /* Currently the locomotive is active. Determine which one of the
03023            * available tracks to choose */
03024           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03025           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03026 
03027           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03028             /* For each signal we find decrease the counter by one.
03029              * We start at two, so the first signal we pass decreases
03030              * this to one, then if we reach the next signal it is
03031              * decreased to zero and we won't pass that new signal. */
03032             Trackdir dir = FindFirstTrackdir(trackdirbits);
03033             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03034                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03035               /* However, we do not want to be stopped by PBS signals
03036                * entered via the back. */
03037               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03038               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03039             }
03040           }
03041 
03042           /* Check if it's a red signal and that force proceed is not clicked. */
03043           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03044             /* In front of a red signal */
03045             Trackdir i = FindFirstTrackdir(trackdirbits);
03046 
03047             /* Don't handle stuck trains here. */
03048             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03049 
03050             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03051               v->cur_speed = 0;
03052               v->subspeed = 0;
03053               v->progress = 255 - 100;
03054               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03055             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03056               v->cur_speed = 0;
03057               v->subspeed = 0;
03058               v->progress = 255 - 10;
03059               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03060                 DiagDirection exitdir = TrackdirToExitdir(i);
03061                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03062 
03063                 exitdir = ReverseDiagDir(exitdir);
03064 
03065                 /* check if a train is waiting on the other side */
03066                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03067               }
03068             }
03069 
03070             /* If we would reverse but are currently in a PBS block and
03071              * reversing of stuck trains is disabled, don't reverse.
03072              * This does not apply if the reason for reversing is a one-way
03073              * signal blocking us, because a train would then be stuck forever. */
03074             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03075                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03076               v->wait_counter = 0;
03077               return false;
03078             }
03079             goto reverse_train_direction;
03080           } else {
03081             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03082           }
03083         } else {
03084           /* The wagon is active, simply follow the prev vehicle. */
03085           if (prev->tile == gp.new_tile) {
03086             /* Choose the same track as prev */
03087             if (prev->track == TRACK_BIT_WORMHOLE) {
03088               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03089                * However, just choose the track into the wormhole. */
03090               assert(IsTunnel(prev->tile));
03091               chosen_track = bits;
03092             } else {
03093               chosen_track = prev->track;
03094             }
03095           } else {
03096             /* Choose the track that leads to the tile where prev is.
03097              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03098              * I.e. when the tile between them has only space for a single vehicle like
03099              *  1) horizontal/vertical track tiles and
03100              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03101              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03102              */
03103             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03104               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03105               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03106               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03107               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03108             };
03109             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03110             assert(IsValidDiagDirection(exitdir));
03111             chosen_track = _connecting_track[enterdir][exitdir];
03112           }
03113           chosen_track &= bits;
03114         }
03115 
03116         /* Make sure chosen track is a valid track */
03117         assert(
03118             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03119             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03120             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03121 
03122         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03123         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03124         gp.x = (gp.x & ~0xF) | b[0];
03125         gp.y = (gp.y & ~0xF) | b[1];
03126         Direction chosen_dir = (Direction)b[2];
03127 
03128         /* Call the landscape function and tell it that the vehicle entered the tile */
03129         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03130         if (HasBit(r, VETS_CANNOT_ENTER)) {
03131           goto invalid_rail;
03132         }
03133 
03134         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03135           Track track = FindFirstTrack(chosen_track);
03136           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03137           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03138             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03139             MarkTileDirtyByTile(gp.new_tile);
03140           }
03141 
03142           /* Clear any track reservation when the last vehicle leaves the tile */
03143           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03144 
03145           v->tile = gp.new_tile;
03146 
03147           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03148             v->First()->RailtypeChanged();
03149           }
03150 
03151           v->track = chosen_track;
03152           assert(v->track);
03153         }
03154 
03155         /* We need to update signal status, but after the vehicle position hash
03156          * has been updated by UpdateInclination() */
03157         update_signals_crossing = true;
03158 
03159         if (chosen_dir != v->direction) {
03160           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03161             const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
03162             DirDiff diff = DirDifference(v->direction, chosen_dir);
03163             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03164           }
03165           direction_changed = true;
03166           v->direction = chosen_dir;
03167         }
03168 
03169         if (v->IsFrontEngine()) {
03170           v->wait_counter = 0;
03171 
03172           /* If we are approaching a crossing that is reserved, play the sound now. */
03173           TileIndex crossing = TrainApproachingCrossingTile(v);
03174           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03175 
03176           /* Always try to extend the reservation when entering a tile. */
03177           CheckNextTrainTile(v);
03178         }
03179 
03180         if (HasBit(r, VETS_ENTERED_STATION)) {
03181           /* The new position is the location where we want to stop */
03182           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03183         }
03184       }
03185     } else {
03186       /* In a tunnel or on a bridge
03187        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03188        * - for bridges, only the middle part - without the bridge heads */
03189       if (!(v->vehstatus & VS_HIDDEN)) {
03190         Train *first = v->First();
03191         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03192       }
03193 
03194       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03195         /* Perform look-ahead on tunnel exit. */
03196         if (v->IsFrontEngine()) {
03197           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03198           CheckNextTrainTile(v);
03199         }
03200         /* Prevent v->UpdateInclination() being called with wrong parameters.
03201          * This could happen if the train was reversed inside the tunnel/bridge. */
03202         if (gp.old_tile == gp.new_tile) {
03203           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03204         }
03205       } else {
03206         v->x_pos = gp.x;
03207         v->y_pos = gp.y;
03208         VehicleMove(v, !(v->vehstatus & VS_HIDDEN));
03209         continue;
03210       }
03211     }
03212 
03213     /* update image of train, as well as delta XY */
03214     v->UpdateDeltaXY(v->direction);
03215 
03216     v->x_pos = gp.x;
03217     v->y_pos = gp.y;
03218 
03219     /* update the Z position of the vehicle */
03220     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03221 
03222     if (prev == NULL) {
03223       /* This is the first vehicle in the train */
03224       AffectSpeedByZChange(v, old_z);
03225     }
03226 
03227     if (update_signals_crossing) {
03228       if (v->IsFrontEngine()) {
03229         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03230           /* We are entering a block with PBS signals right now, but
03231            * not through a PBS signal. This means we don't have a
03232            * reservation right now. As a conventional signal will only
03233            * ever be green if no other train is in the block, getting
03234            * a path should always be possible. If the player built
03235            * such a strange network that it is not possible, the train
03236            * will be marked as stuck and the player has to deal with
03237            * the problem. */
03238           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03239               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03240               !TryPathReserve(v)) {
03241             MarkTrainAsStuck(v);
03242           }
03243         }
03244       }
03245 
03246       /* Signals can only change when the first
03247        * (above) or the last vehicle moves. */
03248       if (v->Next() == NULL) {
03249         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03250         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03251       }
03252     }
03253 
03254     /* Do not check on every tick to save some computing time. */
03255     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03256   }
03257 
03258   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03259 
03260   return true;
03261 
03262 invalid_rail:
03263   /* We've reached end of line?? */
03264   if (prev != NULL) error("Disconnecting train");
03265 
03266 reverse_train_direction:
03267   if (reverse) {
03268     v->wait_counter = 0;
03269     v->cur_speed = 0;
03270     v->subspeed = 0;
03271     ReverseTrainDirection(v);
03272   }
03273 
03274   return false;
03275 }
03276 
03283 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03284 {
03285   TrackBits *trackbits = (TrackBits *)data;
03286 
03287   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03288     TrackBits train_tbits = Train::From(v)->track;
03289     if (train_tbits == TRACK_BIT_WORMHOLE) {
03290       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03291       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03292     } else if (train_tbits != TRACK_BIT_DEPOT) {
03293       *trackbits |= train_tbits;
03294     }
03295   }
03296 
03297   return NULL;
03298 }
03299 
03307 static void DeleteLastWagon(Train *v)
03308 {
03309   Train *first = v->First();
03310 
03311   /* Go to the last wagon and delete the link pointing there
03312    * *u is then the one-before-last wagon, and *v the last
03313    * one which will physically be removed */
03314   Train *u = v;
03315   for (; v->Next() != NULL; v = v->Next()) u = v;
03316   u->SetNext(NULL);
03317 
03318   if (first != v) {
03319     /* Recalculate cached train properties */
03320     first->ConsistChanged(false);
03321     /* Update the depot window if the first vehicle is in depot -
03322      * if v == first, then it is updated in PreDestructor() */
03323     if (first->track == TRACK_BIT_DEPOT) {
03324       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03325     }
03326   }
03327 
03328   /* 'v' shouldn't be accessed after it has been deleted */
03329   TrackBits trackbits = v->track;
03330   TileIndex tile = v->tile;
03331   Owner owner = v->owner;
03332 
03333   delete v;
03334   v = NULL; // make sure nobody will try to read 'v' anymore
03335 
03336   if (trackbits == TRACK_BIT_WORMHOLE) {
03337     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03338     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03339   }
03340 
03341   Track track = TrackBitsToTrack(trackbits);
03342   if (HasReservedTracks(tile, trackbits)) {
03343     UnreserveRailTrack(tile, track);
03344 
03345     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03346     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03347     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03348 
03349     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03350     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03351     Track t;
03352     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03353   }
03354 
03355   /* check if the wagon was on a road/rail-crossing */
03356   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03357 
03358   /* Update signals */
03359   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03360     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03361   } else {
03362     SetSignalsOnBothDir(tile, track, owner);
03363   }
03364 }
03365 
03370 static void ChangeTrainDirRandomly(Train *v)
03371 {
03372   static const DirDiff delta[] = {
03373     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03374   };
03375 
03376   do {
03377     /* We don't need to twist around vehicles if they're not visible */
03378     if (!(v->vehstatus & VS_HIDDEN)) {
03379       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03380       v->UpdateDeltaXY(v->direction);
03381       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03382       /* Refrain from updating the z position of the vehicle when on
03383        * a bridge, because UpdateInclination() will put the vehicle under
03384        * the bridge in that case */
03385       if (v->track != TRACK_BIT_WORMHOLE) v->UpdateInclination(false, false);
03386     }
03387   } while ((v = v->Next()) != NULL);
03388 }
03389 
03395 static bool HandleCrashedTrain(Train *v)
03396 {
03397   int state = ++v->crash_anim_pos;
03398 
03399   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03400     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03401   }
03402 
03403   uint32 r;
03404   if (state <= 200 && Chance16R(1, 7, r)) {
03405     int index = (r * 10 >> 16);
03406 
03407     Vehicle *u = v;
03408     do {
03409       if (--index < 0) {
03410         r = Random();
03411 
03412         CreateEffectVehicleRel(u,
03413           GB(r,  8, 3) + 2,
03414           GB(r, 16, 3) + 2,
03415           GB(r,  0, 3) + 5,
03416           EV_EXPLOSION_SMALL);
03417         break;
03418       }
03419     } while ((u = u->Next()) != NULL);
03420   }
03421 
03422   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03423 
03424   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03425     bool ret = v->Next() != NULL;
03426     DeleteLastWagon(v);
03427     return ret;
03428   }
03429 
03430   return true;
03431 }
03432 
03434 static const uint16 _breakdown_speeds[16] = {
03435   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03436 };
03437 
03438 
03447 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03448 {
03449   /* Calc position within the current tile */
03450   uint x = v->x_pos & 0xF;
03451   uint y = v->y_pos & 0xF;
03452 
03453   /* for diagonal directions, 'x' will be 0..15 -
03454    * for other directions, it will be 1, 3, 5, ..., 15 */
03455   switch (v->direction) {
03456     case DIR_N : x = ~x + ~y + 25; break;
03457     case DIR_NW: x = y;            // FALL THROUGH
03458     case DIR_NE: x = ~x + 16;      break;
03459     case DIR_E : x = ~x + y + 9;   break;
03460     case DIR_SE: x = y;            break;
03461     case DIR_S : x = x + y - 7;    break;
03462     case DIR_W : x = ~y + x + 9;   break;
03463     default: break;
03464   }
03465 
03466   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03467    * does not cross the tile boundary when we do reverse, but as the vehicle's
03468    * location is based on their center, use half a vehicle's length as offset.
03469    * Multiply the half-length by two for straight directions to compensate that
03470    * we only get odd x offsets there. */
03471   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03472     /* we are too near the tile end, reverse now */
03473     v->cur_speed = 0;
03474     if (reverse) ReverseTrainDirection(v);
03475     return false;
03476   }
03477 
03478   /* slow down */
03479   v->vehstatus |= VS_TRAIN_SLOWING;
03480   uint16 break_speed = _breakdown_speeds[x & 0xF];
03481   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03482 
03483   return true;
03484 }
03485 
03486 
03492 static bool TrainCanLeaveTile(const Train *v)
03493 {
03494   /* Exit if inside a tunnel/bridge or a depot */
03495   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03496 
03497   TileIndex tile = v->tile;
03498 
03499   /* entering a tunnel/bridge? */
03500   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03501     DiagDirection dir = GetTunnelBridgeDirection(tile);
03502     if (DiagDirToDir(dir) == v->direction) return false;
03503   }
03504 
03505   /* entering a depot? */
03506   if (IsRailDepotTile(tile)) {
03507     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03508     if (DiagDirToDir(dir) == v->direction) return false;
03509   }
03510 
03511   return true;
03512 }
03513 
03514 
03522 static TileIndex TrainApproachingCrossingTile(const Train *v)
03523 {
03524   assert(v->IsFrontEngine());
03525   assert(!(v->vehstatus & VS_CRASHED));
03526 
03527   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03528 
03529   DiagDirection dir = TrainExitDir(v->direction, v->track);
03530   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03531 
03532   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03533   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03534       !CheckCompatibleRail(v, tile)) {
03535     return INVALID_TILE;
03536   }
03537 
03538   return tile;
03539 }
03540 
03541 
03549 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03550 {
03551   /* First, handle broken down train */
03552 
03553   int t = v->breakdown_ctr;
03554   if (t > 1) {
03555     v->vehstatus |= VS_TRAIN_SLOWING;
03556 
03557     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03558     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03559   } else {
03560     v->vehstatus &= ~VS_TRAIN_SLOWING;
03561   }
03562 
03563   if (!TrainCanLeaveTile(v)) return true;
03564 
03565   /* Determine the non-diagonal direction in which we will exit this tile */
03566   DiagDirection dir = TrainExitDir(v->direction, v->track);
03567   /* Calculate next tile */
03568   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03569 
03570   /* Determine the track status on the next tile */
03571   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03572   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03573 
03574   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03575   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03576 
03577   /* We are sure the train is not entering a depot, it is detected above */
03578 
03579   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03580   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03581   if (_settings_game.pf.forbid_90_deg) {
03582     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03583   }
03584 
03585   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03586   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03587     return TrainApproachingLineEnd(v, false, reverse);
03588   }
03589 
03590   /* approaching red signal */
03591   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03592 
03593   /* approaching a rail/road crossing? then make it red */
03594   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03595 
03596   return true;
03597 }
03598 
03599 
03600 static bool TrainLocoHandler(Train *v, bool mode)
03601 {
03602   /* train has crashed? */
03603   if (v->vehstatus & VS_CRASHED) {
03604     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03605   }
03606 
03607   if (v->force_proceed != TFP_NONE) {
03608     ClrBit(v->flags, VRF_TRAIN_STUCK);
03609     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03610   }
03611 
03612   /* train is broken down? */
03613   if (v->HandleBreakdown()) return true;
03614 
03615   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03616     ReverseTrainDirection(v);
03617   }
03618 
03619   /* exit if train is stopped */
03620   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03621 
03622   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03623   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03624     v->wait_counter = 0;
03625     v->cur_speed = 0;
03626     v->subspeed = 0;
03627     ClrBit(v->flags, VRF_LEAVING_STATION);
03628     ReverseTrainDirection(v);
03629     return true;
03630   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03631     /* Try to reserve a path when leaving the station as we
03632      * might not be marked as wanting a reservation, e.g.
03633      * when an overlength train gets turned around in a station. */
03634     DiagDirection dir = TrainExitDir(v->direction, v->track);
03635     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03636 
03637     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03638       TryPathReserve(v, true, true);
03639     }
03640     ClrBit(v->flags, VRF_LEAVING_STATION);
03641   }
03642 
03643   v->HandleLoading(mode);
03644 
03645   if (v->current_order.IsType(OT_LOADING)) return true;
03646 
03647   if (CheckTrainStayInDepot(v)) return true;
03648 
03649   if (!mode) v->ShowVisualEffect();
03650 
03651   /* We had no order but have an order now, do look ahead. */
03652   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03653     CheckNextTrainTile(v);
03654   }
03655 
03656   /* Handle stuck trains. */
03657   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03658     ++v->wait_counter;
03659 
03660     /* Should we try reversing this tick if still stuck? */
03661     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03662 
03663     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03664     if (!TryPathReserve(v)) {
03665       /* Still stuck. */
03666       if (turn_around) ReverseTrainDirection(v);
03667 
03668       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03669         /* Show message to player. */
03670         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03671           SetDParam(0, v->index);
03672           AddVehicleNewsItem(
03673             STR_NEWS_TRAIN_IS_STUCK,
03674             NS_ADVICE,
03675             v->index
03676           );
03677         }
03678         v->wait_counter = 0;
03679       }
03680       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03681       if (v->force_proceed == TFP_NONE) return true;
03682       ClrBit(v->flags, VRF_TRAIN_STUCK);
03683       v->wait_counter = 0;
03684       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03685     }
03686   }
03687 
03688   if (v->current_order.IsType(OT_LEAVESTATION)) {
03689     v->current_order.Free();
03690     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03691     return true;
03692   }
03693 
03694   int j = v->UpdateSpeed();
03695 
03696   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03697   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03698     /* If we manually stopped, we're not force-proceeding anymore. */
03699     v->force_proceed = TFP_NONE;
03700     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03701   }
03702 
03703   int adv_spd = v->GetAdvanceDistance();
03704   if (j < adv_spd) {
03705     /* if the vehicle has speed 0, update the last_speed field. */
03706     if (v->cur_speed == 0) v->SetLastSpeed();
03707   } else {
03708     TrainCheckIfLineEnds(v);
03709     /* Loop until the train has finished moving. */
03710     for (;;) {
03711       j -= adv_spd;
03712       TrainController(v, NULL);
03713       /* Don't continue to move if the train crashed. */
03714       if (CheckTrainCollision(v)) break;
03715       /* Determine distance to next map position */
03716       adv_spd = v->GetAdvanceDistance();
03717 
03718       /* No more moving this tick */
03719       if (j < adv_spd || v->cur_speed == 0) break;
03720 
03721       OrderType order_type = v->current_order.GetType();
03722       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03723       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03724             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03725             IsTileType(v->tile, MP_STATION) &&
03726             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03727         ProcessOrders(v);
03728       }
03729     }
03730     v->SetLastSpeed();
03731   }
03732 
03733   for (Train *u = v; u != NULL; u = u->Next()) {
03734     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03735 
03736     u->UpdateViewport(false, false);
03737   }
03738 
03739   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03740 
03741   return true;
03742 }
03743 
03744 
03745 
03746 Money Train::GetRunningCost() const
03747 {
03748   Money cost = 0;
03749   const Train *v = this;
03750 
03751   do {
03752     const Engine *e = v->GetEngine();
03753     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03754 
03755     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03756     if (cost_factor == 0) continue;
03757 
03758     /* Halve running cost for multiheaded parts */
03759     if (v->IsMultiheaded()) cost_factor /= 2;
03760 
03761     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03762   } while ((v = v->GetNextVehicle()) != NULL);
03763 
03764   return cost;
03765 }
03766 
03767 
03768 bool Train::Tick()
03769 {
03770   this->tick_counter++;
03771 
03772   if (this->IsFrontEngine()) {
03773     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03774 
03775     this->current_order_time++;
03776 
03777     if (!TrainLocoHandler(this, false)) return false;
03778 
03779     return TrainLocoHandler(this, true);
03780   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03781     /* Delete flooded standalone wagon chain */
03782     if (++this->crash_anim_pos >= 4400) {
03783       delete this;
03784       return false;
03785     }
03786   }
03787 
03788   return true;
03789 }
03790 
03791 static void CheckIfTrainNeedsService(Train *v)
03792 {
03793   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03794   if (v->IsInDepot()) {
03795     VehicleServiceInDepot(v);
03796     return;
03797   }
03798 
03799   uint max_penalty;
03800   switch (_settings_game.pf.pathfinder_for_trains) {
03801     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03802     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03803     default: NOT_REACHED();
03804   }
03805 
03806   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03807   /* Only go to the depot if it is not too far out of our way. */
03808   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03809     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03810       /* If we were already heading for a depot but it has
03811        * suddenly moved farther away, we continue our normal
03812        * schedule? */
03813       v->current_order.MakeDummy();
03814       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03815     }
03816     return;
03817   }
03818 
03819   DepotID depot = GetDepotIndex(tfdd.tile);
03820 
03821   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03822       v->current_order.GetDestination() != depot &&
03823       !Chance16(3, 16)) {
03824     return;
03825   }
03826 
03827   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03828   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03829   v->dest_tile = tfdd.tile;
03830   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03831 }
03832 
03833 void Train::OnNewDay()
03834 {
03835   AgeVehicle(this);
03836 
03837   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03838 
03839   if (this->IsFrontEngine()) {
03840     CheckVehicleBreakdown(this);
03841 
03842     CheckIfTrainNeedsService(this);
03843 
03844     CheckOrders(this);
03845 
03846     /* update destination */
03847     if (this->current_order.IsType(OT_GOTO_STATION)) {
03848       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03849       if (tile != INVALID_TILE) this->dest_tile = tile;
03850     }
03851 
03852     if (this->running_ticks != 0) {
03853       /* running costs */
03854       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03855 
03856       this->profit_this_year -= cost.GetCost();
03857       this->running_ticks = 0;
03858 
03859       SubtractMoneyFromCompanyFract(this->owner, cost);
03860 
03861       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03862       SetWindowClassesDirty(WC_TRAINS_LIST);
03863     }
03864   }
03865 }
03866 
03867 Trackdir Train::GetVehicleTrackdir() const
03868 {
03869   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03870 
03871   if (this->track == TRACK_BIT_DEPOT) {
03872     /* We'll assume the train is facing outwards */
03873     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03874   }
03875 
03876   if (this->track == TRACK_BIT_WORMHOLE) {
03877     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03878     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03879   }
03880 
03881   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03882 }