train_cmd.cpp

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00001 /* $Id: train_cmd.cpp 23744 2012-01-03 22:36:35Z frosch $ */
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 "error.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 "newgrf_sound.h"
00021 #include "newgrf_text.h"
00022 #include "strings_func.h"
00023 #include "viewport_func.h"
00024 #include "vehicle_func.h"
00025 #include "sound_func.h"
00026 #include "ai/ai.hpp"
00027 #include "game/game.hpp"
00028 #include "newgrf_station.h"
00029 #include "effectvehicle_func.h"
00030 #include "network/network.h"
00031 #include "spritecache.h"
00032 #include "core/random_func.hpp"
00033 #include "company_base.h"
00034 #include "newgrf.h"
00035 #include "order_backup.h"
00036 #include "zoom_func.h"
00037 
00038 #include "table/strings.h"
00039 #include "table/train_cmd.h"
00040 
00041 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00042 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00043 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00044 static TileIndex TrainApproachingCrossingTile(const Train *v);
00045 static void CheckIfTrainNeedsService(Train *v);
00046 static void CheckNextTrainTile(Train *v);
00047 
00048 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00049 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00050 
00051 
00059 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00060 {
00061   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00062 
00063   DiagDirection diagdir = DirToDiagDir(direction);
00064 
00065   /* Determine the diagonal direction in which we will exit this tile */
00066   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00067     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00068   }
00069 
00070   return diagdir;
00071 }
00072 
00073 
00079 byte FreightWagonMult(CargoID cargo)
00080 {
00081   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00082   return _settings_game.vehicle.freight_trains;
00083 }
00084 
00086 void CheckTrainsLengths()
00087 {
00088   const Train *v;
00089   bool first = true;
00090 
00091   FOR_ALL_TRAINS(v) {
00092     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00093       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00094         if (u->track != TRACK_BIT_DEPOT) {
00095           if ((w->track != TRACK_BIT_DEPOT &&
00096               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00097               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00098             SetDParam(0, v->index);
00099             SetDParam(1, v->owner);
00100             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00101 
00102             if (!_networking && first) {
00103               first = false;
00104               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00105             }
00106             /* Break so we warn only once for each train. */
00107             break;
00108           }
00109         }
00110       }
00111     }
00112   }
00113 }
00114 
00119 void Train::RailtypeChanged()
00120 {
00121   for (Train *u = this; u != NULL; u = u->Next()) {
00122     /* The wagon-is-powered-state should not change, so the weight does not change. */
00123     u->UpdateVisualEffect(false);
00124   }
00125   this->PowerChanged();
00126   if (this->IsFrontEngine()) this->UpdateAcceleration();
00127 }
00128 
00135 void Train::ConsistChanged(bool same_length)
00136 {
00137   uint16 max_speed = UINT16_MAX;
00138 
00139   assert(this->IsFrontEngine() || this->IsFreeWagon());
00140 
00141   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00142   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00143   this->gcache.cached_total_length = 0;
00144   this->compatible_railtypes = RAILTYPES_NONE;
00145 
00146   bool train_can_tilt = true;
00147 
00148   for (Train *u = this; u != NULL; u = u->Next()) {
00149     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00150 
00151     /* Check the this->first cache. */
00152     assert(u->First() == this);
00153 
00154     /* update the 'first engine' */
00155     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00156     u->railtype = rvi_u->railtype;
00157 
00158     if (u->IsEngine()) first_engine = u->engine_type;
00159 
00160     /* Set user defined data to its default value */
00161     u->tcache.user_def_data = rvi_u->user_def_data;
00162     this->InvalidateNewGRFCache();
00163     u->InvalidateNewGRFCache();
00164   }
00165 
00166   for (Train *u = this; u != NULL; u = u->Next()) {
00167     /* Update user defined data (must be done before other properties) */
00168     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00169     this->InvalidateNewGRFCache();
00170     u->InvalidateNewGRFCache();
00171   }
00172 
00173   for (Train *u = this; u != NULL; u = u->Next()) {
00174     const Engine *e_u = u->GetEngine();
00175     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00176 
00177     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00178 
00179     /* Cache wagon override sprite group. NULL is returned if there is none */
00180     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00181 
00182     /* Reset colour map */
00183     u->colourmap = PAL_NONE;
00184 
00185     /* Update powered-wagon-status and visual effect */
00186     u->UpdateVisualEffect(true);
00187 
00188     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00189         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00190       /* wagon is powered */
00191       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00192     } else {
00193       ClrBit(u->flags, VRF_POWEREDWAGON);
00194     }
00195 
00196     if (!u->IsArticulatedPart()) {
00197       /* Do not count powered wagons for the compatible railtypes, as wagons always
00198          have railtype normal */
00199       if (rvi_u->power > 0) {
00200         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00201       }
00202 
00203       /* Some electric engines can be allowed to run on normal rail. It happens to all
00204        * existing electric engines when elrails are disabled and then re-enabled */
00205       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00206         u->railtype = RAILTYPE_RAIL;
00207         u->compatible_railtypes |= RAILTYPES_RAIL;
00208       }
00209 
00210       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00211       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00212         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00213         if (speed != 0) max_speed = min(speed, max_speed);
00214       }
00215     }
00216 
00217     u->cargo_cap = e_u->DetermineCapacity(u);
00218     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00219 
00220     /* check the vehicle length (callback) */
00221     uint16 veh_len = CALLBACK_FAILED;
00222     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00223       /* Use callback 36 */
00224       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00225     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00226       /* Use callback 11 */
00227       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00228     }
00229     if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00230       ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00231     }
00232     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00233     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00234 
00235     /* verify length hasn't changed */
00236     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00237 
00238     /* update vehicle length? */
00239     if (!same_length) u->gcache.cached_veh_length = veh_len;
00240 
00241     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00242     this->InvalidateNewGRFCache();
00243     u->InvalidateNewGRFCache();
00244   }
00245 
00246   /* store consist weight/max speed in cache */
00247   this->vcache.cached_max_speed = max_speed;
00248   this->tcache.cached_tilt = train_can_tilt;
00249   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00250 
00251   /* 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) */
00252   this->CargoChanged();
00253 
00254   if (this->IsFrontEngine()) {
00255     this->UpdateAcceleration();
00256     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00257     InvalidateWindowData(WC_VEHICLE_REFIT, this->index);
00258   }
00259 }
00260 
00271 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00272 {
00273   const Station *st = Station::Get(station_id);
00274   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00275   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00276 
00277   /* Default to the middle of the station for stations stops that are not in
00278    * the order list like intermediate stations when non-stop is disabled */
00279   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00280   if (v->gcache.cached_total_length >= *station_length) {
00281     /* The train is longer than the station, make it stop at the far end of the platform */
00282     osl = OSL_PLATFORM_FAR_END;
00283   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00284     osl = v->current_order.GetStopLocation();
00285   }
00286 
00287   /* The stop location of the FRONT! of the train */
00288   int stop;
00289   switch (osl) {
00290     default: NOT_REACHED();
00291 
00292     case OSL_PLATFORM_NEAR_END:
00293       stop = v->gcache.cached_total_length;
00294       break;
00295 
00296     case OSL_PLATFORM_MIDDLE:
00297       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00298       break;
00299 
00300     case OSL_PLATFORM_FAR_END:
00301       stop = *station_length;
00302       break;
00303   }
00304 
00305   /* Subtract half the front vehicle length of the train so we get the real
00306    * stop location of the train. */
00307   return stop - (v->gcache.cached_veh_length + 1) / 2;
00308 }
00309 
00310 
00315 int Train::GetCurveSpeedLimit() const
00316 {
00317   assert(this->First() == this);
00318 
00319   static const int absolute_max_speed = UINT16_MAX;
00320   int max_speed = absolute_max_speed;
00321 
00322   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00323 
00324   int curvecount[2] = {0, 0};
00325 
00326   /* first find the curve speed limit */
00327   int numcurve = 0;
00328   int sum = 0;
00329   int pos = 0;
00330   int lastpos = -1;
00331   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00332     Direction this_dir = u->direction;
00333     Direction next_dir = u->Next()->direction;
00334 
00335     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00336     if (dirdiff == DIRDIFF_SAME) continue;
00337 
00338     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00339     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00340     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00341       if (lastpos != -1) {
00342         numcurve++;
00343         sum += pos - lastpos;
00344         if (pos - lastpos == 1 && max_speed > 88) {
00345           max_speed = 88;
00346         }
00347       }
00348       lastpos = pos;
00349     }
00350 
00351     /* if we have a 90 degree turn, fix the speed limit to 60 */
00352     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00353       max_speed = 61;
00354     }
00355   }
00356 
00357   if (numcurve > 0 && max_speed > 88) {
00358     if (curvecount[0] == 1 && curvecount[1] == 1) {
00359       max_speed = absolute_max_speed;
00360     } else {
00361       sum /= numcurve;
00362       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00363     }
00364   }
00365 
00366   if (max_speed != absolute_max_speed) {
00367     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00368     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00369     max_speed += (max_speed / 2) * rti->curve_speed;
00370 
00371     if (this->tcache.cached_tilt) {
00372       /* Apply max_speed bonus of 20% for a tilting train */
00373       max_speed += max_speed / 5;
00374     }
00375   }
00376 
00377   return max_speed;
00378 }
00379 
00384 int Train::GetCurrentMaxSpeed() const
00385 {
00386   int max_speed = this->tcache.cached_max_curve_speed;
00387   assert(max_speed == this->GetCurveSpeedLimit());
00388 
00389   if (IsRailStationTile(this->tile)) {
00390     StationID sid = GetStationIndex(this->tile);
00391     if (this->current_order.ShouldStopAtStation(this, sid)) {
00392       int station_ahead;
00393       int station_length;
00394       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00395 
00396       /* The distance to go is whatever is still ahead of the train minus the
00397        * distance from the train's stop location to the end of the platform */
00398       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00399 
00400       if (distance_to_go > 0) {
00401         int st_max_speed = 120;
00402 
00403         int delta_v = this->cur_speed / (distance_to_go + 1);
00404         if (max_speed > (this->cur_speed - delta_v)) {
00405           st_max_speed = this->cur_speed - (delta_v / 10);
00406         }
00407 
00408         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00409         max_speed = min(max_speed, st_max_speed);
00410       }
00411     }
00412   }
00413 
00414   for (const Train *u = this; u != NULL; u = u->Next()) {
00415     if (u->track == TRACK_BIT_DEPOT) {
00416       max_speed = min(max_speed, 61);
00417       break;
00418     }
00419   }
00420 
00421   return min(max_speed, this->gcache.cached_max_track_speed);
00422 }
00423 
00425 void Train::UpdateAcceleration()
00426 {
00427   assert(this->IsFrontEngine());
00428 
00429   uint power = this->gcache.cached_power;
00430   uint weight = this->gcache.cached_weight;
00431   assert(weight != 0);
00432   this->acceleration = Clamp(power / weight * 4, 1, 255);
00433 }
00434 
00440 int Train::GetDisplayImageWidth(Point *offset) const
00441 {
00442   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00443   int vehicle_pitch = 0;
00444 
00445   const Engine *e = this->GetEngine();
00446   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00447     reference_width = e->GetGRF()->traininfo_vehicle_width;
00448     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00449   }
00450 
00451   if (offset != NULL) {
00452     offset->x = reference_width / 2;
00453     offset->y = vehicle_pitch;
00454   }
00455   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00456 }
00457 
00458 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00459 {
00460   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00461 }
00462 
00469 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00470 {
00471   uint8 spritenum = this->spritenum;
00472   SpriteID sprite;
00473 
00474   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00475 
00476   if (is_custom_sprite(spritenum)) {
00477     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00478     if (sprite != 0) return sprite;
00479 
00480     spritenum = this->GetEngine()->original_image_index;
00481   }
00482 
00483   sprite = GetDefaultTrainSprite(spritenum, direction);
00484 
00485   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00486 
00487   return sprite;
00488 }
00489 
00490 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00491 {
00492   const Engine *e = Engine::Get(engine);
00493   Direction dir = rear_head ? DIR_E : DIR_W;
00494   uint8 spritenum = e->u.rail.image_index;
00495 
00496   if (is_custom_sprite(spritenum)) {
00497     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00498     if (sprite != 0) {
00499       if (e->GetGRF() != NULL) {
00500         y += e->GetGRF()->traininfo_vehicle_pitch;
00501       }
00502       return sprite;
00503     }
00504 
00505     spritenum = Engine::Get(engine)->original_image_index;
00506   }
00507 
00508   if (rear_head) spritenum++;
00509 
00510   return GetDefaultTrainSprite(spritenum, DIR_W);
00511 }
00512 
00513 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00514 {
00515   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00516     int yf = y;
00517     int yr = y;
00518 
00519     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00520     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00521     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00522     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00523 
00524     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);
00525 
00526     DrawSprite(spritef, pal, preferred_x - 14, yf);
00527     DrawSprite(spriter, pal, preferred_x + 15, yr);
00528   } else {
00529     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00530     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00531     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));
00532     DrawSprite(sprite, pal, preferred_x, y);
00533   }
00534 }
00535 
00544 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00545 {
00546   const RailVehicleInfo *rvi = &e->u.rail;
00547 
00548   /* Check that the wagon can drive on the track in question */
00549   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00550 
00551   if (flags & DC_EXEC) {
00552     Train *v = new Train();
00553     *ret = v;
00554     v->spritenum = rvi->image_index;
00555 
00556     v->engine_type = e->index;
00557     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00558 
00559     DiagDirection dir = GetRailDepotDirection(tile);
00560 
00561     v->direction = DiagDirToDir(dir);
00562     v->tile = tile;
00563 
00564     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00565     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00566 
00567     v->x_pos = x;
00568     v->y_pos = y;
00569     v->z_pos = GetSlopePixelZ(x, y);
00570     v->owner = _current_company;
00571     v->track = TRACK_BIT_DEPOT;
00572     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00573 
00574     v->SetWagon();
00575 
00576     v->SetFreeWagon();
00577     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00578 
00579     v->cargo_type = e->GetDefaultCargoType();
00580     v->cargo_cap = rvi->capacity;
00581 
00582     v->railtype = rvi->railtype;
00583 
00584     v->build_year = _cur_year;
00585     v->cur_image = SPR_IMG_QUERY;
00586     v->random_bits = VehicleRandomBits();
00587 
00588     v->group_id = DEFAULT_GROUP;
00589 
00590     AddArticulatedParts(v);
00591 
00592     _new_vehicle_id = v->index;
00593 
00594     VehicleUpdatePosition(v);
00595     v->First()->ConsistChanged(false);
00596     UpdateTrainGroupID(v->First());
00597 
00598     CheckConsistencyOfArticulatedVehicle(v);
00599 
00600     /* Try to connect the vehicle to one of free chains of wagons. */
00601     Train *w;
00602     FOR_ALL_TRAINS(w) {
00603       if (w->tile == tile &&              
00604           w->IsFreeWagon() &&             
00605           w->engine_type == e->index &&   
00606           w->First() != v &&              
00607           !(w->vehstatus & VS_CRASHED)) { 
00608         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00609         break;
00610       }
00611     }
00612   }
00613 
00614   return CommandCost();
00615 }
00616 
00618 static void NormalizeTrainVehInDepot(const Train *u)
00619 {
00620   const Train *v;
00621   FOR_ALL_TRAINS(v) {
00622     if (v->IsFreeWagon() && v->tile == u->tile &&
00623         v->track == TRACK_BIT_DEPOT) {
00624       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00625           CMD_MOVE_RAIL_VEHICLE).Failed())
00626         break;
00627     }
00628   }
00629 }
00630 
00631 static void AddRearEngineToMultiheadedTrain(Train *v)
00632 {
00633   Train *u = new Train();
00634   v->value >>= 1;
00635   u->value = v->value;
00636   u->direction = v->direction;
00637   u->owner = v->owner;
00638   u->tile = v->tile;
00639   u->x_pos = v->x_pos;
00640   u->y_pos = v->y_pos;
00641   u->z_pos = v->z_pos;
00642   u->track = TRACK_BIT_DEPOT;
00643   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00644   u->spritenum = v->spritenum + 1;
00645   u->cargo_type = v->cargo_type;
00646   u->cargo_subtype = v->cargo_subtype;
00647   u->cargo_cap = v->cargo_cap;
00648   u->railtype = v->railtype;
00649   u->engine_type = v->engine_type;
00650   u->build_year = v->build_year;
00651   u->cur_image = SPR_IMG_QUERY;
00652   u->random_bits = VehicleRandomBits();
00653   v->SetMultiheaded();
00654   u->SetMultiheaded();
00655   v->SetNext(u);
00656   VehicleUpdatePosition(u);
00657 
00658   /* Now we need to link the front and rear engines together */
00659   v->other_multiheaded_part = u;
00660   u->other_multiheaded_part = v;
00661 }
00662 
00672 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00673 {
00674   const RailVehicleInfo *rvi = &e->u.rail;
00675 
00676   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00677 
00678   /* Check if depot and new engine uses the same kind of tracks *
00679    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00680   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00681 
00682   if (flags & DC_EXEC) {
00683     DiagDirection dir = GetRailDepotDirection(tile);
00684     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00685     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00686 
00687     Train *v = new Train();
00688     *ret = v;
00689     v->direction = DiagDirToDir(dir);
00690     v->tile = tile;
00691     v->owner = _current_company;
00692     v->x_pos = x;
00693     v->y_pos = y;
00694     v->z_pos = GetSlopePixelZ(x, y);
00695     v->track = TRACK_BIT_DEPOT;
00696     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00697     v->spritenum = rvi->image_index;
00698     v->cargo_type = e->GetDefaultCargoType();
00699     v->cargo_cap = rvi->capacity;
00700     v->last_station_visited = INVALID_STATION;
00701 
00702     v->engine_type = e->index;
00703     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00704 
00705     v->reliability = e->reliability;
00706     v->reliability_spd_dec = e->reliability_spd_dec;
00707     v->max_age = e->GetLifeLengthInDays();
00708 
00709     v->railtype = rvi->railtype;
00710     _new_vehicle_id = v->index;
00711 
00712     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00713     v->date_of_last_service = _date;
00714     v->build_year = _cur_year;
00715     v->cur_image = SPR_IMG_QUERY;
00716     v->random_bits = VehicleRandomBits();
00717 
00718     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00719 
00720     v->group_id = DEFAULT_GROUP;
00721 
00722     v->SetFrontEngine();
00723     v->SetEngine();
00724 
00725     VehicleUpdatePosition(v);
00726 
00727     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00728       AddRearEngineToMultiheadedTrain(v);
00729     } else {
00730       AddArticulatedParts(v);
00731     }
00732 
00733     v->ConsistChanged(false);
00734     UpdateTrainGroupID(v);
00735 
00736     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00737       NormalizeTrainVehInDepot(v);
00738     }
00739 
00740     CheckConsistencyOfArticulatedVehicle(v);
00741   }
00742 
00743   return CommandCost();
00744 }
00745 
00750 bool Train::IsInDepot() const
00751 {
00752   /* Is the front engine stationary in the depot? */
00753   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00754 
00755   /* Check whether the rest is also already trying to enter the depot. */
00756   for (const Train *v = this; v != NULL; v = v->Next()) {
00757     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00758   }
00759 
00760   return true;
00761 }
00762 
00767 bool Train::IsStoppedInDepot() const
00768 {
00769   /* Are we stopped? Of course wagons don't really care... */
00770   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00771   return this->IsInDepot();
00772 }
00773 
00774 static Train *FindGoodVehiclePos(const Train *src)
00775 {
00776   EngineID eng = src->engine_type;
00777   TileIndex tile = src->tile;
00778 
00779   Train *dst;
00780   FOR_ALL_TRAINS(dst) {
00781     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00782       /* check so all vehicles in the line have the same engine. */
00783       Train *t = dst;
00784       while (t->engine_type == eng) {
00785         t = t->Next();
00786         if (t == NULL) return dst;
00787       }
00788     }
00789   }
00790 
00791   return NULL;
00792 }
00793 
00795 typedef SmallVector<Train *, 16> TrainList;
00796 
00802 static void MakeTrainBackup(TrainList &list, Train *t)
00803 {
00804   for (; t != NULL; t = t->Next()) *list.Append() = t;
00805 }
00806 
00811 static void RestoreTrainBackup(TrainList &list)
00812 {
00813   /* No train, nothing to do. */
00814   if (list.Length() == 0) return;
00815 
00816   Train *prev = NULL;
00817   /* Iterate over the list and rebuild it. */
00818   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00819     Train *t = *iter;
00820     if (prev != NULL) {
00821       prev->SetNext(t);
00822     } else if (t->Previous() != NULL) {
00823       /* Make sure the head of the train is always the first in the chain. */
00824       t->Previous()->SetNext(NULL);
00825     }
00826     prev = t;
00827   }
00828 }
00829 
00835 static void RemoveFromConsist(Train *part, bool chain = false)
00836 {
00837   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00838 
00839   /* Unlink at the front, but make it point to the next
00840    * vehicle after the to be remove part. */
00841   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00842 
00843   /* Unlink at the back */
00844   tail->SetNext(NULL);
00845 }
00846 
00852 static void InsertInConsist(Train *dst, Train *chain)
00853 {
00854   /* We do not want to add something in the middle of an articulated part. */
00855   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00856 
00857   chain->Last()->SetNext(dst->Next());
00858   dst->SetNext(chain);
00859 }
00860 
00866 static void NormaliseDualHeads(Train *t)
00867 {
00868   for (; t != NULL; t = t->GetNextVehicle()) {
00869     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00870 
00871     /* Make sure that there are no free cars before next engine */
00872     Train *u;
00873     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00874 
00875     if (u == t->other_multiheaded_part) continue;
00876 
00877     /* Remove the part from the 'wrong' train */
00878     RemoveFromConsist(t->other_multiheaded_part);
00879     /* And add it to the 'right' train */
00880     InsertInConsist(u, t->other_multiheaded_part);
00881   }
00882 }
00883 
00888 static void NormaliseSubtypes(Train *chain)
00889 {
00890   /* Nothing to do */
00891   if (chain == NULL) return;
00892 
00893   /* We must be the first in the chain. */
00894   assert(chain->Previous() == NULL);
00895 
00896   /* Set the appropriate bits for the first in the chain. */
00897   if (chain->IsWagon()) {
00898     chain->SetFreeWagon();
00899   } else {
00900     assert(chain->IsEngine());
00901     chain->SetFrontEngine();
00902   }
00903 
00904   /* Now clear the bits for the rest of the chain */
00905   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00906     t->ClearFreeWagon();
00907     t->ClearFrontEngine();
00908   }
00909 }
00910 
00920 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00921 {
00922   /* Just add 'new' engines and subtract the original ones.
00923    * If that's less than or equal to 0 we can be sure we did
00924    * not add any engines (read: trains) along the way. */
00925   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00926       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00927       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00928       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00929     return CommandCost();
00930   }
00931 
00932   /* Get a free unit number and check whether it's within the bounds.
00933    * There will always be a maximum of one new train. */
00934   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00935 
00936   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00937 }
00938 
00944 static CommandCost CheckTrainAttachment(Train *t)
00945 {
00946   /* No multi-part train, no need to check. */
00947   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00948 
00949   /* The maximum length for a train. For each part we decrease this by one
00950    * and if the result is negative the train is simply too long. */
00951   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00952 
00953   Train *head = t;
00954   Train *prev = t;
00955 
00956   /* Break the prev -> t link so it always holds within the loop. */
00957   t = t->Next();
00958   prev->SetNext(NULL);
00959 
00960   /* Make sure the cache is cleared. */
00961   head->InvalidateNewGRFCache();
00962 
00963   while (t != NULL) {
00964     allowed_len -= t->gcache.cached_veh_length;
00965 
00966     Train *next = t->Next();
00967 
00968     /* Unlink the to-be-added piece; it is already unlinked from the previous
00969      * part due to the fact that the prev -> t link is broken. */
00970     t->SetNext(NULL);
00971 
00972     /* Don't check callback for articulated or rear dual headed parts */
00973     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00974       /* Back up and clear the first_engine data to avoid using wagon override group */
00975       EngineID first_engine = t->gcache.first_engine;
00976       t->gcache.first_engine = INVALID_ENGINE;
00977 
00978       /* We don't want the cache to interfere. head's cache is cleared before
00979        * the loop and after each callback does not need to be cleared here. */
00980       t->InvalidateNewGRFCache();
00981 
00982       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00983 
00984       /* Restore original first_engine data */
00985       t->gcache.first_engine = first_engine;
00986 
00987       /* We do not want to remember any cached variables from the test run */
00988       t->InvalidateNewGRFCache();
00989       head->InvalidateNewGRFCache();
00990 
00991       if (callback != CALLBACK_FAILED) {
00992         /* A failing callback means everything is okay */
00993         StringID error = STR_NULL;
00994 
00995         if (head->GetGRF()->grf_version < 8) {
00996           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00997           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00998           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00999         } else {
01000           if (callback < 0x400) {
01001             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01002           } else {
01003             switch (callback) {
01004               case 0x400: // allow if railtypes match (always the case for OpenTTD)
01005               case 0x401: // allow
01006                 break;
01007 
01008               default:    // unknown reason -> disallow
01009               case 0x402: // disallow attaching
01010                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01011                 break;
01012             }
01013           }
01014         }
01015 
01016         if (error != STR_NULL) return_cmd_error(error);
01017       }
01018     }
01019 
01020     /* And link it to the new part. */
01021     prev->SetNext(t);
01022     prev = t;
01023     t = next;
01024   }
01025 
01026   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01027   return CommandCost();
01028 }
01029 
01040 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01041 {
01042   /* Check whether we may actually construct the trains. */
01043   CommandCost ret = CheckTrainAttachment(src);
01044   if (ret.Failed()) return ret;
01045   ret = CheckTrainAttachment(dst);
01046   if (ret.Failed()) return ret;
01047 
01048   /* Check whether we need to build a new train. */
01049   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01050 }
01051 
01060 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01061 {
01062   /* First determine the front of the two resulting trains */
01063   if (*src_head == *dst_head) {
01064     /* If we aren't moving part(s) to a new train, we are just moving the
01065      * front back and there is not destination head. */
01066     *dst_head = NULL;
01067   } else if (*dst_head == NULL) {
01068     /* If we are moving to a new train the head of the move train would become
01069      * the head of the new vehicle. */
01070     *dst_head = src;
01071   }
01072 
01073   if (src == *src_head) {
01074     /* If we are moving the front of a train then we are, in effect, creating
01075      * a new head for the train. Point to that. Unless we are moving the whole
01076      * train in which case there is not 'source' train anymore.
01077      * In case we are a multiheaded part we want the complete thing to come
01078      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01079      * that is followed by a rear multihead we do not want to include that. */
01080     *src_head = move_chain ? NULL :
01081         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01082   }
01083 
01084   /* Now it's just simply removing the part that we are going to move from the
01085    * source train and *if* the destination is a not a new train add the chain
01086    * at the destination location. */
01087   RemoveFromConsist(src, move_chain);
01088   if (*dst_head != src) InsertInConsist(dst, src);
01089 
01090   /* Now normalise the dual heads, that is move the dual heads around in such
01091    * a way that the head and rear of a dual head are in the same train */
01092   NormaliseDualHeads(*src_head);
01093   NormaliseDualHeads(*dst_head);
01094 }
01095 
01101 static void NormaliseTrainHead(Train *head)
01102 {
01103   /* Not much to do! */
01104   if (head == NULL) return;
01105 
01106   /* Tell the 'world' the train changed. */
01107   head->ConsistChanged(false);
01108   UpdateTrainGroupID(head);
01109 
01110   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01111   if (!head->IsFrontEngine()) return;
01112 
01113   /* Update the refit button and window */
01114   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01115   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01116 
01117   /* If we don't have a unit number yet, set one. */
01118   if (head->unitnumber != 0) return;
01119   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01120 }
01121 
01134 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01135 {
01136   VehicleID s = GB(p1, 0, 20);
01137   VehicleID d = GB(p2, 0, 20);
01138   bool move_chain = HasBit(p1, 20);
01139 
01140   Train *src = Train::GetIfValid(s);
01141   if (src == NULL) return CMD_ERROR;
01142 
01143   CommandCost ret = CheckOwnership(src->owner);
01144   if (ret.Failed()) return ret;
01145 
01146   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01147   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01148 
01149   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01150   Train *dst;
01151   if (d == INVALID_VEHICLE) {
01152     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01153   } else {
01154     dst = Train::GetIfValid(d);
01155     if (dst == NULL) return CMD_ERROR;
01156 
01157     CommandCost ret = CheckOwnership(dst->owner);
01158     if (ret.Failed()) return ret;
01159 
01160     /* Do not allow appending to crashed vehicles, too */
01161     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01162   }
01163 
01164   /* if an articulated part is being handled, deal with its parent vehicle */
01165   src = src->GetFirstEnginePart();
01166   if (dst != NULL) {
01167     dst = dst->GetFirstEnginePart();
01168   }
01169 
01170   /* don't move the same vehicle.. */
01171   if (src == dst) return CommandCost();
01172 
01173   /* locate the head of the two chains */
01174   Train *src_head = src->First();
01175   Train *dst_head;
01176   if (dst != NULL) {
01177     dst_head = dst->First();
01178     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01179     /* Now deal with articulated part of destination wagon */
01180     dst = dst->GetLastEnginePart();
01181   } else {
01182     dst_head = NULL;
01183   }
01184 
01185   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01186 
01187   /* When moving all wagons, we can't have the same src_head and dst_head */
01188   if (move_chain && src_head == dst_head) return CommandCost();
01189 
01190   /* When moving a multiheaded part to be place after itself, bail out. */
01191   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01192 
01193   /* Check if all vehicles in the source train are stopped inside a depot. */
01194   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01195 
01196   /* Check if all vehicles in the destination train are stopped inside a depot. */
01197   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01198 
01199   /* First make a backup of the order of the trains. That way we can do
01200    * whatever we want with the order and later on easily revert. */
01201   TrainList original_src;
01202   TrainList original_dst;
01203 
01204   MakeTrainBackup(original_src, src_head);
01205   MakeTrainBackup(original_dst, dst_head);
01206 
01207   /* Also make backup of the original heads as ArrangeTrains can change them.
01208    * For the destination head we do not care if it is the same as the source
01209    * head because in that case it's just a copy. */
01210   Train *original_src_head = src_head;
01211   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01212 
01213   /* We want this information from before the rearrangement, but execute this after the validation. */
01214   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01215   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01216 
01217   /* (Re)arrange the trains in the wanted arrangement. */
01218   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01219 
01220   if ((flags & DC_AUTOREPLACE) == 0) {
01221     /* If the autoreplace flag is set we do not need to test for the validity
01222      * because we are going to revert the train to its original state. As we
01223      * assume the original state was correct autoreplace can skip this. */
01224     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01225     if (ret.Failed()) {
01226       /* Restore the train we had. */
01227       RestoreTrainBackup(original_src);
01228       RestoreTrainBackup(original_dst);
01229       return ret;
01230     }
01231   }
01232 
01233   /* do it? */
01234   if (flags & DC_EXEC) {
01235     /* Remove old heads from the statistics */
01236     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01237     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01238 
01239     /* First normalise the sub types of the chains. */
01240     NormaliseSubtypes(src_head);
01241     NormaliseSubtypes(dst_head);
01242 
01243     /* There are 14 different cases:
01244      *  1) front engine gets moved to a new train, it stays a front engine.
01245      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01246      *     b) the 'next' part is an engine that becomes a front engine.
01247      *     c) there is no 'next' part, nothing else happens
01248      *  2) front engine gets moved to another train, it is not a front engine anymore
01249      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01250      *     b) the 'next' part is an engine that becomes a front engine.
01251      *     c) there is no 'next' part, nothing else happens
01252      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01253      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01254      *     b) the 'next' part is an engine that becomes a front engine.
01255      *  4) free wagon gets moved
01256      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01257      *     b) the 'next' part is an engine that becomes a front engine.
01258      *     c) there is no 'next' part, nothing else happens
01259      *  5) non front engine gets moved and becomes a new train, nothing else happens
01260      *  6) non front engine gets moved within a train / to another train, nothing hapens
01261      *  7) wagon gets moved, nothing happens
01262      */
01263     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01264       /* Cases #2 and #3: the front engine gets trashed. */
01265       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01266       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01267       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01268       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01269       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01270       SetWindowDirty(WC_COMPANY, _current_company);
01271 
01272       /* Delete orders, group stuff and the unit number as we're not the
01273        * front of any vehicle anymore. */
01274       DeleteVehicleOrders(src);
01275       RemoveVehicleFromGroup(src);
01276       src->unitnumber = 0;
01277     }
01278 
01279     /* We weren't a front engine but are becoming one. So
01280      * we should be put in the default group. */
01281     if (original_src_head != src && dst_head == src) {
01282       SetTrainGroupID(src, DEFAULT_GROUP);
01283       SetWindowDirty(WC_COMPANY, _current_company);
01284     }
01285 
01286     /* Add new heads to statistics */
01287     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01288     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01289 
01290     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01291     NormaliseTrainHead(src_head);
01292     NormaliseTrainHead(dst_head);
01293 
01294     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01295       CheckCargoCapacity(src_head);
01296       CheckCargoCapacity(dst_head);
01297     }
01298 
01299     /* We are undoubtedly changing something in the depot and train list. */
01300     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01301     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01302   } else {
01303     /* We don't want to execute what we're just tried. */
01304     RestoreTrainBackup(original_src);
01305     RestoreTrainBackup(original_dst);
01306   }
01307 
01308   return CommandCost();
01309 }
01310 
01322 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01323 {
01324   /* Check if we deleted a vehicle window */
01325   Window *w = NULL;
01326 
01327   /* Sell a chain of vehicles or not? */
01328   bool sell_chain = HasBit(data, 0);
01329 
01330   Train *v = Train::From(t)->GetFirstEnginePart();
01331   Train *first = v->First();
01332 
01333   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01334 
01335   /* First make a backup of the order of the train. That way we can do
01336    * whatever we want with the order and later on easily revert. */
01337   TrainList original;
01338   MakeTrainBackup(original, first);
01339 
01340   /* We need to keep track of the new head and the head of what we're going to sell. */
01341   Train *new_head = first;
01342   Train *sell_head = NULL;
01343 
01344   /* Split the train in the wanted way. */
01345   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01346 
01347   /* We don't need to validate the second train; it's going to be sold. */
01348   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01349   if (ret.Failed()) {
01350     /* Restore the train we had. */
01351     RestoreTrainBackup(original);
01352     return ret;
01353   }
01354 
01355   CommandCost cost(EXPENSES_NEW_VEHICLES);
01356   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01357 
01358   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01359     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01360   }
01361 
01362   /* do it? */
01363   if (flags & DC_EXEC) {
01364     /* First normalise the sub types of the chain. */
01365     NormaliseSubtypes(new_head);
01366 
01367     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01368       /* We are selling the front engine. In this case we want to
01369        * 'give' the order, unit number and such to the new head. */
01370       new_head->orders.list = first->orders.list;
01371       new_head->AddToShared(first);
01372       DeleteVehicleOrders(first);
01373 
01374       /* Copy other important data from the front engine */
01375       new_head->CopyVehicleConfigAndStatistics(first);
01376       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01377 
01378       /* If we deleted a window then open a new one for the 'new' train */
01379       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01380     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01381       OrderBackup::Backup(v, user);
01382     }
01383 
01384     /* We need to update the information about the train. */
01385     NormaliseTrainHead(new_head);
01386 
01387     /* We are undoubtedly changing something in the depot and train list. */
01388     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01389     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01390 
01391     /* Actually delete the sold 'goods' */
01392     delete sell_head;
01393   } else {
01394     /* We don't want to execute what we're just tried. */
01395     RestoreTrainBackup(original);
01396   }
01397 
01398   return cost;
01399 }
01400 
01401 void Train::UpdateDeltaXY(Direction direction)
01402 {
01403   /* Set common defaults. */
01404   this->x_offs    = -1;
01405   this->y_offs    = -1;
01406   this->x_extent  =  3;
01407   this->y_extent  =  3;
01408   this->z_extent  =  6;
01409   this->x_bb_offs =  0;
01410   this->y_bb_offs =  0;
01411 
01412   if (!IsDiagonalDirection(direction)) {
01413     static const int _sign_table[] =
01414     {
01415       // x, y
01416       -1, -1, // DIR_N
01417       -1,  1, // DIR_E
01418        1,  1, // DIR_S
01419        1, -1, // DIR_W
01420     };
01421 
01422     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01423 
01424     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01425     this->x_offs -= half_shorten * _sign_table[direction];
01426     this->y_offs -= half_shorten * _sign_table[direction + 1];
01427     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01428     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01429   } else {
01430     switch (direction) {
01431         /* Shorten southern corner of the bounding box according the vehicle length
01432          * and center the bounding box on the vehicle. */
01433       case DIR_NE:
01434         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01435         this->x_extent  = this->gcache.cached_veh_length - 1;
01436         this->x_bb_offs = -1;
01437         break;
01438 
01439       case DIR_NW:
01440         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01441         this->y_extent  = this->gcache.cached_veh_length - 1;
01442         this->y_bb_offs = -1;
01443         break;
01444 
01445         /* Move northern corner of the bounding box down according to vehicle length
01446          * and center the bounding box on the vehicle. */
01447       case DIR_SW:
01448         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01449         this->x_extent  = VEHICLE_LENGTH - 1;
01450         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01451         break;
01452 
01453       case DIR_SE:
01454         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01455         this->y_extent  = VEHICLE_LENGTH - 1;
01456         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01457         break;
01458 
01459       default:
01460         NOT_REACHED();
01461     }
01462   }
01463 }
01464 
01469 static void MarkTrainAsStuck(Train *v)
01470 {
01471   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01472     /* It is the first time the problem occurred, set the "train stuck" flag. */
01473     SetBit(v->flags, VRF_TRAIN_STUCK);
01474 
01475     v->wait_counter = 0;
01476 
01477     /* Stop train */
01478     v->cur_speed = 0;
01479     v->subspeed = 0;
01480     v->SetLastSpeed();
01481 
01482     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01483   }
01484 }
01485 
01493 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01494 {
01495   uint16 flag1 = *swap_flag1;
01496   uint16 flag2 = *swap_flag2;
01497 
01498   /* Clear the flags */
01499   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01500   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01501   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01502   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01503 
01504   /* Reverse the rail-flags (if needed) */
01505   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01506     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01507   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01508     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01509   }
01510   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01511     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01512   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01513     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01514   }
01515 }
01516 
01521 static void UpdateStatusAfterSwap(Train *v)
01522 {
01523   /* Reverse the direction. */
01524   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01525 
01526   /* Call the proper EnterTile function unless we are in a wormhole. */
01527   if (v->track != TRACK_BIT_WORMHOLE) {
01528     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01529   } else {
01530     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01531      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01532      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01533      * when we shouldn't have. Check if this is the case. */
01534     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01535     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01536       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01537       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01538         /* We have just left the wormhole, possibly set the
01539          * "goingdown" bit. UpdateInclination() can be used
01540          * because we are at the border of the tile. */
01541         VehicleUpdatePosition(v);
01542         v->UpdateInclination(true, true);
01543         return;
01544       }
01545     }
01546   }
01547 
01548   VehicleUpdatePosition(v);
01549   v->UpdateViewport(true, true);
01550 }
01551 
01558 void ReverseTrainSwapVeh(Train *v, int l, int r)
01559 {
01560   Train *a, *b;
01561 
01562   /* locate vehicles to swap */
01563   for (a = v; l != 0; l--) a = a->Next();
01564   for (b = v; r != 0; r--) b = b->Next();
01565 
01566   if (a != b) {
01567     /* swap the hidden bits */
01568     {
01569       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01570       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01571       a->vehstatus = tmp;
01572     }
01573 
01574     Swap(a->track, b->track);
01575     Swap(a->direction, b->direction);
01576     Swap(a->x_pos, b->x_pos);
01577     Swap(a->y_pos, b->y_pos);
01578     Swap(a->tile,  b->tile);
01579     Swap(a->z_pos, b->z_pos);
01580 
01581     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01582 
01583     UpdateStatusAfterSwap(a);
01584     UpdateStatusAfterSwap(b);
01585   } else {
01586     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01587      * This is a little bit redundant way, a->gv_flags will
01588      * be (re)set twice, but it reduces code duplication */
01589     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01590     UpdateStatusAfterSwap(a);
01591   }
01592 
01593   /* Update power of the train in case tiles were different rail type. */
01594   v->RailtypeChanged();
01595 }
01596 
01597 
01603 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01604 {
01605   return (v->type == VEH_TRAIN) ? v : NULL;
01606 }
01607 
01608 
01615 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01616 {
01617   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01618 
01619   Train *t = Train::From(v);
01620   if (!t->IsFrontEngine()) return NULL;
01621 
01622   TileIndex tile = *(TileIndex *)data;
01623 
01624   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01625 
01626   return t;
01627 }
01628 
01629 
01636 static bool TrainApproachingCrossing(TileIndex tile)
01637 {
01638   assert(IsLevelCrossingTile(tile));
01639 
01640   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01641   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01642 
01643   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01644 
01645   dir = ReverseDiagDir(dir);
01646   tile_from = tile + TileOffsByDiagDir(dir);
01647 
01648   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01649 }
01650 
01651 
01658 void UpdateLevelCrossing(TileIndex tile, bool sound)
01659 {
01660   assert(IsLevelCrossingTile(tile));
01661 
01662   /* train on crossing || train approaching crossing || reserved */
01663   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01664 
01665   if (new_state != IsCrossingBarred(tile)) {
01666     if (new_state && sound) {
01667       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01668     }
01669     SetCrossingBarred(tile, new_state);
01670     MarkTileDirtyByTile(tile);
01671   }
01672 }
01673 
01674 
01680 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01681 {
01682   if (!IsCrossingBarred(tile)) {
01683     BarCrossing(tile);
01684     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01685     MarkTileDirtyByTile(tile);
01686   }
01687 }
01688 
01689 
01695 static void AdvanceWagonsBeforeSwap(Train *v)
01696 {
01697   Train *base = v;
01698   Train *first = base; // first vehicle to move
01699   Train *last = v->Last(); // last vehicle to move
01700   uint length = CountVehiclesInChain(v);
01701 
01702   while (length > 2) {
01703     last = last->Previous();
01704     first = first->Next();
01705 
01706     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01707 
01708     /* do not update images now
01709      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01710     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01711 
01712     base = first; // == base->Next()
01713     length -= 2;
01714   }
01715 }
01716 
01717 
01723 static void AdvanceWagonsAfterSwap(Train *v)
01724 {
01725   /* first of all, fix the situation when the train was entering a depot */
01726   Train *dep = v; // last vehicle in front of just left depot
01727   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01728     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01729   }
01730 
01731   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01732 
01733   if (leave != NULL) {
01734     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01735     int d = TicksToLeaveDepot(dep);
01736 
01737     if (d <= 0) {
01738       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01739       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01740       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01741     }
01742   } else {
01743     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01744   }
01745 
01746   Train *base = v;
01747   Train *first = base; // first vehicle to move
01748   Train *last = v->Last(); // last vehicle to move
01749   uint length = CountVehiclesInChain(v);
01750 
01751   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01752    * they have already correct spacing, so we have to make sure they are moved how they should */
01753   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01754 
01755   while (length > 2) {
01756     /* we reached vehicle (originally) in front of a depot, stop now
01757      * (we would move wagons that are already moved with new wagon length). */
01758     if (base == dep) break;
01759 
01760     /* the last wagon was that one leaving a depot, so do not move it anymore */
01761     if (last == dep) nomove = true;
01762 
01763     last = last->Previous();
01764     first = first->Next();
01765 
01766     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01767 
01768     /* do not update images now */
01769     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01770 
01771     base = first; // == base->Next()
01772     length -= 2;
01773   }
01774 }
01775 
01780 void ReverseTrainDirection(Train *v)
01781 {
01782   if (IsRailDepotTile(v->tile)) {
01783     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01784   }
01785 
01786   /* Clear path reservation in front if train is not stuck. */
01787   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01788 
01789   /* Check if we were approaching a rail/road-crossing */
01790   TileIndex crossing = TrainApproachingCrossingTile(v);
01791 
01792   /* count number of vehicles */
01793   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01794 
01795   AdvanceWagonsBeforeSwap(v);
01796 
01797   /* swap start<>end, start+1<>end-1, ... */
01798   int l = 0;
01799   do {
01800     ReverseTrainSwapVeh(v, l++, r--);
01801   } while (l <= r);
01802 
01803   AdvanceWagonsAfterSwap(v);
01804 
01805   if (IsRailDepotTile(v->tile)) {
01806     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01807   }
01808 
01809   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01810 
01811   ClrBit(v->flags, VRF_REVERSING);
01812 
01813   /* recalculate cached data */
01814   v->ConsistChanged(true);
01815 
01816   /* update all images */
01817   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01818 
01819   /* update crossing we were approaching */
01820   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01821 
01822   /* maybe we are approaching crossing now, after reversal */
01823   crossing = TrainApproachingCrossingTile(v);
01824   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01825 
01826   /* If we are inside a depot after reversing, don't bother with path reserving. */
01827   if (v->track == TRACK_BIT_DEPOT) {
01828     /* Can't be stuck here as inside a depot is always a safe tile. */
01829     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01830     ClrBit(v->flags, VRF_TRAIN_STUCK);
01831     return;
01832   }
01833 
01834   /* TrainExitDir does not always produce the desired dir for depots and
01835    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01836   DiagDirection dir = TrainExitDir(v->direction, v->track);
01837   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01838 
01839   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01840     /* If we are currently on a tile with conventional signals, we can't treat the
01841      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01842     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01843       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01844       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01845 
01846     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01847     if (TryPathReserve(v, false, first_tile_okay)) {
01848       /* Do a look-ahead now in case our current tile was already a safe tile. */
01849       CheckNextTrainTile(v);
01850     } else if (v->current_order.GetType() != OT_LOADING) {
01851       /* Do not wait for a way out when we're still loading */
01852       MarkTrainAsStuck(v);
01853     }
01854   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01855     /* A train not inside a PBS block can't be stuck. */
01856     ClrBit(v->flags, VRF_TRAIN_STUCK);
01857     v->wait_counter = 0;
01858   }
01859 }
01860 
01870 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01871 {
01872   Train *v = Train::GetIfValid(p1);
01873   if (v == NULL) return CMD_ERROR;
01874 
01875   CommandCost ret = CheckOwnership(v->owner);
01876   if (ret.Failed()) return ret;
01877 
01878   if (p2 != 0) {
01879     /* turn a single unit around */
01880 
01881     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01882       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01883     }
01884     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01885 
01886     Train *front = v->First();
01887     /* make sure the vehicle is stopped in the depot */
01888     if (!front->IsStoppedInDepot()) {
01889       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01890     }
01891 
01892     if (flags & DC_EXEC) {
01893       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01894 
01895       front->ConsistChanged(false);
01896       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01897       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01898       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01899       SetWindowClassesDirty(WC_TRAINS_LIST);
01900     }
01901   } else {
01902     /* turn the whole train around */
01903     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01904 
01905     if (flags & DC_EXEC) {
01906       /* Properly leave the station if we are loading and won't be loading anymore */
01907       if (v->current_order.IsType(OT_LOADING)) {
01908         const Vehicle *last = v;
01909         while (last->Next() != NULL) last = last->Next();
01910 
01911         /* not a station || different station --> leave the station */
01912         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01913           v->LeaveStation();
01914         }
01915       }
01916 
01917       /* We cancel any 'skip signal at dangers' here */
01918       v->force_proceed = TFP_NONE;
01919       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01920 
01921       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01922         ToggleBit(v->flags, VRF_REVERSING);
01923       } else {
01924         v->cur_speed = 0;
01925         v->SetLastSpeed();
01926         HideFillingPercent(&v->fill_percent_te_id);
01927         ReverseTrainDirection(v);
01928       }
01929     }
01930   }
01931   return CommandCost();
01932 }
01933 
01943 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01944 {
01945   Train *t = Train::GetIfValid(p1);
01946   if (t == NULL) return CMD_ERROR;
01947 
01948   CommandCost ret = CheckOwnership(t->owner);
01949   if (ret.Failed()) return ret;
01950 
01951 
01952   if (flags & DC_EXEC) {
01953     /* If we are forced to proceed, cancel that order.
01954      * If we are marked stuck we would want to force the train
01955      * to proceed to the next signal. In the other cases we
01956      * would like to pass the signal at danger and run till the
01957      * next signal we encounter. */
01958     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01959     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01960   }
01961 
01962   return CommandCost();
01963 }
01964 
01972 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01973 {
01974   assert(!(v->vehstatus & VS_CRASHED));
01975 
01976   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01977 
01978   PBSTileInfo origin = FollowTrainReservation(v);
01979   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01980 
01981   switch (_settings_game.pf.pathfinder_for_trains) {
01982     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01983     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01984 
01985     default: NOT_REACHED();
01986   }
01987 }
01988 
01996 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01997 {
01998   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01999   if (tfdd.best_length == UINT_MAX) return false;
02000 
02001   if (location    != NULL) *location    = tfdd.tile;
02002   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
02003   if (reverse     != NULL) *reverse     = tfdd.reverse;
02004 
02005   return true;
02006 }
02007 
02009 void Train::PlayLeaveStationSound() const
02010 {
02011   static const SoundFx sfx[] = {
02012     SND_04_TRAIN,
02013     SND_0A_TRAIN_HORN,
02014     SND_0A_TRAIN_HORN,
02015     SND_47_MAGLEV_2,
02016     SND_41_MAGLEV
02017   };
02018 
02019   if (PlayVehicleSound(this, VSE_START)) return;
02020 
02021   EngineID engtype = this->engine_type;
02022   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02023 }
02024 
02029 static void CheckNextTrainTile(Train *v)
02030 {
02031   /* Don't do any look-ahead if path_backoff_interval is 255. */
02032   if (_settings_game.pf.path_backoff_interval == 255) return;
02033 
02034   /* Exit if we are inside a depot. */
02035   if (v->track == TRACK_BIT_DEPOT) return;
02036 
02037   switch (v->current_order.GetType()) {
02038     /* Exit if we reached our destination depot. */
02039     case OT_GOTO_DEPOT:
02040       if (v->tile == v->dest_tile) return;
02041       break;
02042 
02043     case OT_GOTO_WAYPOINT:
02044       /* If we reached our waypoint, make sure we see that. */
02045       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02046       break;
02047 
02048     case OT_NOTHING:
02049     case OT_LEAVESTATION:
02050     case OT_LOADING:
02051       /* Exit if the current order doesn't have a destination, but the train has orders. */
02052       if (v->GetNumOrders() > 0) return;
02053       break;
02054 
02055     default:
02056       break;
02057   }
02058   /* Exit if we are on a station tile and are going to stop. */
02059   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02060 
02061   Trackdir td = v->GetVehicleTrackdir();
02062 
02063   /* On a tile with a red non-pbs signal, don't look ahead. */
02064   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02065       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02066       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02067 
02068   CFollowTrackRail ft(v);
02069   if (!ft.Follow(v->tile, td)) return;
02070 
02071   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02072     /* Next tile is not reserved. */
02073     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02074       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02075         /* If the next tile is a PBS signal, try to make a reservation. */
02076         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02077         if (_settings_game.pf.forbid_90_deg) {
02078           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02079         }
02080         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02081       }
02082     }
02083   }
02084 }
02085 
02091 static bool CheckTrainStayInDepot(Train *v)
02092 {
02093   /* bail out if not all wagons are in the same depot or not in a depot at all */
02094   for (const Train *u = v; u != NULL; u = u->Next()) {
02095     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02096   }
02097 
02098   /* if the train got no power, then keep it in the depot */
02099   if (v->gcache.cached_power == 0) {
02100     v->vehstatus |= VS_STOPPED;
02101     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02102     return true;
02103   }
02104 
02105   SigSegState seg_state;
02106 
02107   if (v->force_proceed == TFP_NONE) {
02108     /* force proceed was not pressed */
02109     if (++v->wait_counter < 37) {
02110       SetWindowClassesDirty(WC_TRAINS_LIST);
02111       return true;
02112     }
02113 
02114     v->wait_counter = 0;
02115 
02116     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02117     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02118       /* Full and no PBS signal in block or depot reserved, can't exit. */
02119       SetWindowClassesDirty(WC_TRAINS_LIST);
02120       return true;
02121     }
02122   } else {
02123     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02124   }
02125 
02126   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02127   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02128     /* We need to have a reservation for this to work. */
02129     if (HasDepotReservation(v->tile)) return true;
02130     SetDepotReservation(v->tile, true);
02131     VehicleEnterDepot(v);
02132     return true;
02133   }
02134 
02135   /* Only leave when we can reserve a path to our destination. */
02136   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02137     /* No path and no force proceed. */
02138     SetWindowClassesDirty(WC_TRAINS_LIST);
02139     MarkTrainAsStuck(v);
02140     return true;
02141   }
02142 
02143   SetDepotReservation(v->tile, true);
02144   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02145 
02146   VehicleServiceInDepot(v);
02147   SetWindowClassesDirty(WC_TRAINS_LIST);
02148   v->PlayLeaveStationSound();
02149 
02150   v->track = TRACK_BIT_X;
02151   if (v->direction & 2) v->track = TRACK_BIT_Y;
02152 
02153   v->vehstatus &= ~VS_HIDDEN;
02154   v->cur_speed = 0;
02155 
02156   v->UpdateViewport(true, true);
02157   VehicleUpdatePosition(v);
02158   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02159   v->UpdateAcceleration();
02160   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02161 
02162   return false;
02163 }
02164 
02171 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02172 {
02173   DiagDirection dir = TrackdirToExitdir(track_dir);
02174 
02175   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02176     /* Are we just leaving a tunnel/bridge? */
02177     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02178       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02179 
02180       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02181         /* Free the reservation only if no other train is on the tiles. */
02182         SetTunnelBridgeReservation(tile, false);
02183         SetTunnelBridgeReservation(end, false);
02184 
02185         if (_settings_client.gui.show_track_reservation) {
02186           MarkTileDirtyByTile(tile);
02187           MarkTileDirtyByTile(end);
02188         }
02189       }
02190     }
02191   } else if (IsRailStationTile(tile)) {
02192     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02193     /* If the new tile is not a further tile of the same station, we
02194      * clear the reservation for the whole platform. */
02195     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02196       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02197     }
02198   } else {
02199     /* Any other tile */
02200     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02201   }
02202 }
02203 
02210 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02211 {
02212   assert(v->IsFrontEngine());
02213 
02214   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02215   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02216   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02217   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02218 
02219   /* Don't free reservation if it's not ours. */
02220   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02221 
02222   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02223   while (ft.Follow(tile, td)) {
02224     tile = ft.m_new_tile;
02225     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02226     td = RemoveFirstTrackdir(&bits);
02227     assert(bits == TRACKDIR_BIT_NONE);
02228 
02229     if (!IsValidTrackdir(td)) break;
02230 
02231     if (IsTileType(tile, MP_RAILWAY)) {
02232       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02233         /* Conventional signal along trackdir: remove reservation and stop. */
02234         UnreserveRailTrack(tile, TrackdirToTrack(td));
02235         break;
02236       }
02237       if (HasPbsSignalOnTrackdir(tile, td)) {
02238         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02239           /* Red PBS signal? Can't be our reservation, would be green then. */
02240           break;
02241         } else {
02242           /* Turn the signal back to red. */
02243           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02244           MarkTileDirtyByTile(tile);
02245         }
02246       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02247         break;
02248       }
02249     }
02250 
02251     /* Don't free first station/bridge/tunnel if we are on it. */
02252     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);
02253 
02254     free_tile = true;
02255   }
02256 }
02257 
02258 static const byte _initial_tile_subcoord[6][4][3] = {
02259 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02260 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02261 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02262 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02263 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02264 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02265 };
02266 
02279 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02280 {
02281   switch (_settings_game.pf.pathfinder_for_trains) {
02282     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02283     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02284 
02285     default: NOT_REACHED();
02286   }
02287 }
02288 
02294 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02295 {
02296   PBSTileInfo origin = FollowTrainReservation(v);
02297 
02298   CFollowTrackRail ft(v);
02299 
02300   TileIndex tile = origin.tile;
02301   Trackdir  cur_td = origin.trackdir;
02302   while (ft.Follow(tile, cur_td)) {
02303     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02304       /* Possible signal tile. */
02305       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02306     }
02307 
02308     if (_settings_game.pf.forbid_90_deg) {
02309       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02310       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02311     }
02312 
02313     /* Station, depot or waypoint are a possible target. */
02314     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02315     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02316       /* Choice found or possible target encountered.
02317        * On finding a possible target, we need to stop and let the pathfinder handle the
02318        * remaining path. This is because we don't know if this target is in one of our
02319        * orders, so we might cause pathfinding to fail later on if we find a choice.
02320        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02321        * a wrong path not leading to our next destination. */
02322       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02323 
02324       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02325        * actually starts its search at the first unreserved tile. */
02326       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02327 
02328       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02329       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02330       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02331       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02332     }
02333 
02334     tile = ft.m_new_tile;
02335     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02336 
02337     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02338       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02339       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02340       /* Safe position is all good, path valid and okay. */
02341       return PBSTileInfo(tile, cur_td, true);
02342     }
02343 
02344     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02345   }
02346 
02347   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02348     /* End of line, path valid and okay. */
02349     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02350   }
02351 
02352   /* Sorry, can't reserve path, back out. */
02353   tile = origin.tile;
02354   cur_td = origin.trackdir;
02355   TileIndex stopped = ft.m_old_tile;
02356   Trackdir  stopped_td = ft.m_old_td;
02357   while (tile != stopped || cur_td != stopped_td) {
02358     if (!ft.Follow(tile, cur_td)) break;
02359 
02360     if (_settings_game.pf.forbid_90_deg) {
02361       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02362       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02363     }
02364     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02365 
02366     tile = ft.m_new_tile;
02367     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02368 
02369     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02370   }
02371 
02372   /* Path invalid. */
02373   return PBSTileInfo();
02374 }
02375 
02386 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02387 {
02388   switch (_settings_game.pf.pathfinder_for_trains) {
02389     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02390     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02391 
02392     default: NOT_REACHED();
02393   }
02394 }
02395 
02397 class VehicleOrderSaver {
02398 private:
02399   Train          *v;
02400   Order          old_order;
02401   TileIndex      old_dest_tile;
02402   StationID      old_last_station_visited;
02403   VehicleOrderID index;
02404   bool           suppress_implicit_orders;
02405 
02406 public:
02407   VehicleOrderSaver(Train *_v) :
02408     v(_v),
02409     old_order(_v->current_order),
02410     old_dest_tile(_v->dest_tile),
02411     old_last_station_visited(_v->last_station_visited),
02412     index(_v->cur_real_order_index),
02413     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02414   {
02415   }
02416 
02417   ~VehicleOrderSaver()
02418   {
02419     this->v->current_order = this->old_order;
02420     this->v->dest_tile = this->old_dest_tile;
02421     this->v->last_station_visited = this->old_last_station_visited;
02422     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02423   }
02424 
02430   bool SwitchToNextOrder(bool skip_first)
02431   {
02432     if (this->v->GetNumOrders() == 0) return false;
02433 
02434     if (skip_first) ++this->index;
02435 
02436     int conditional_depth = 0;
02437 
02438     do {
02439       /* Wrap around. */
02440       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02441 
02442       Order *order = this->v->GetOrder(this->index);
02443       assert(order != NULL);
02444 
02445       switch (order->GetType()) {
02446         case OT_GOTO_DEPOT:
02447           /* Skip service in depot orders when the train doesn't need service. */
02448           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02449         case OT_GOTO_STATION:
02450         case OT_GOTO_WAYPOINT:
02451           this->v->current_order = *order;
02452           return UpdateOrderDest(this->v, order, 0, true);
02453         case OT_CONDITIONAL: {
02454           if (conditional_depth > this->v->GetNumOrders()) return false;
02455           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02456           if (next != INVALID_VEH_ORDER_ID) {
02457             conditional_depth++;
02458             this->index = next;
02459             /* Don't increment next, so no break here. */
02460             continue;
02461           }
02462           break;
02463         }
02464         default:
02465           break;
02466       }
02467       /* Don't increment inside the while because otherwise conditional
02468        * orders can lead to an infinite loop. */
02469       ++this->index;
02470     } while (this->index != this->v->cur_real_order_index);
02471 
02472     return false;
02473   }
02474 };
02475 
02476 /* choose a track */
02477 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02478 {
02479   Track best_track = INVALID_TRACK;
02480   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02481   bool changed_signal = false;
02482 
02483   assert((tracks & ~TRACK_BIT_MASK) == 0);
02484 
02485   if (got_reservation != NULL) *got_reservation = false;
02486 
02487   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02488   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02489   /* Do we have a suitable reserved track? */
02490   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02491 
02492   /* Quick return in case only one possible track is available */
02493   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02494     Track track = FindFirstTrack(tracks);
02495     /* We need to check for signals only here, as a junction tile can't have signals. */
02496     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02497       do_track_reservation = true;
02498       changed_signal = true;
02499       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02500     } else if (!do_track_reservation) {
02501       return track;
02502     }
02503     best_track = track;
02504   }
02505 
02506   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02507   DiagDirection dest_enterdir = enterdir;
02508   if (do_track_reservation) {
02509     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02510     if (res_dest.tile == INVALID_TILE) {
02511       /* Reservation failed? */
02512       if (mark_stuck) MarkTrainAsStuck(v);
02513       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02514       return FindFirstTrack(tracks);
02515     }
02516     if (res_dest.okay) {
02517       /* Got a valid reservation that ends at a safe target, quick exit. */
02518       if (got_reservation != NULL) *got_reservation = true;
02519       if (changed_signal) MarkTileDirtyByTile(tile);
02520       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02521       return best_track;
02522     }
02523 
02524     /* Check if the train needs service here, so it has a chance to always find a depot.
02525      * Also check if the current order is a service order so we don't reserve a path to
02526      * the destination but instead to the next one if service isn't needed. */
02527     CheckIfTrainNeedsService(v);
02528     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02529   }
02530 
02531   /* Save the current train order. The destructor will restore the old order on function exit. */
02532   VehicleOrderSaver orders(v);
02533 
02534   /* If the current tile is the destination of the current order and
02535    * a reservation was requested, advance to the next order.
02536    * Don't advance on a depot order as depots are always safe end points
02537    * for a path and no look-ahead is necessary. This also avoids a
02538    * problem with depot orders not part of the order list when the
02539    * order list itself is empty. */
02540   if (v->current_order.IsType(OT_LEAVESTATION)) {
02541     orders.SwitchToNextOrder(false);
02542   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02543       v->current_order.IsType(OT_GOTO_STATION) ?
02544       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02545       v->tile == v->dest_tile))) {
02546     orders.SwitchToNextOrder(true);
02547   }
02548 
02549   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02550     /* Pathfinders are able to tell that route was only 'guessed'. */
02551     bool      path_found = true;
02552     TileIndex new_tile = res_dest.tile;
02553 
02554     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02555     if (new_tile == tile) best_track = next_track;
02556     v->HandlePathfindingResult(path_found);
02557   }
02558 
02559   /* No track reservation requested -> finished. */
02560   if (!do_track_reservation) return best_track;
02561 
02562   /* A path was found, but could not be reserved. */
02563   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02564     if (mark_stuck) MarkTrainAsStuck(v);
02565     FreeTrainTrackReservation(v);
02566     return best_track;
02567   }
02568 
02569   /* No possible reservation target found, we are probably lost. */
02570   if (res_dest.tile == INVALID_TILE) {
02571     /* Try to find any safe destination. */
02572     PBSTileInfo origin = FollowTrainReservation(v);
02573     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02574       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02575       best_track = FindFirstTrack(res);
02576       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02577       if (got_reservation != NULL) *got_reservation = true;
02578       if (changed_signal) MarkTileDirtyByTile(tile);
02579     } else {
02580       FreeTrainTrackReservation(v);
02581       if (mark_stuck) MarkTrainAsStuck(v);
02582     }
02583     return best_track;
02584   }
02585 
02586   if (got_reservation != NULL) *got_reservation = true;
02587 
02588   /* Reservation target found and free, check if it is safe. */
02589   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02590     /* Extend reservation until we have found a safe position. */
02591     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02592     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02593     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02594     if (_settings_game.pf.forbid_90_deg) {
02595       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02596     }
02597 
02598     /* Get next order with destination. */
02599     if (orders.SwitchToNextOrder(true)) {
02600       PBSTileInfo cur_dest;
02601       bool path_found;
02602       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02603       if (cur_dest.tile != INVALID_TILE) {
02604         res_dest = cur_dest;
02605         if (res_dest.okay) continue;
02606         /* Path found, but could not be reserved. */
02607         FreeTrainTrackReservation(v);
02608         if (mark_stuck) MarkTrainAsStuck(v);
02609         if (got_reservation != NULL) *got_reservation = false;
02610         changed_signal = false;
02611         break;
02612       }
02613     }
02614     /* No order or no safe position found, try any position. */
02615     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02616       FreeTrainTrackReservation(v);
02617       if (mark_stuck) MarkTrainAsStuck(v);
02618       if (got_reservation != NULL) *got_reservation = false;
02619       changed_signal = false;
02620     }
02621     break;
02622   }
02623 
02624   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02625 
02626   if (changed_signal) MarkTileDirtyByTile(tile);
02627 
02628   return best_track;
02629 }
02630 
02639 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02640 {
02641   assert(v->IsFrontEngine());
02642 
02643   /* We have to handle depots specially as the track follower won't look
02644    * at the depot tile itself but starts from the next tile. If we are still
02645    * inside the depot, a depot reservation can never be ours. */
02646   if (v->track == TRACK_BIT_DEPOT) {
02647     if (HasDepotReservation(v->tile)) {
02648       if (mark_as_stuck) MarkTrainAsStuck(v);
02649       return false;
02650     } else {
02651       /* Depot not reserved, but the next tile might be. */
02652       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02653       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02654     }
02655   }
02656 
02657   Vehicle *other_train = NULL;
02658   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02659   /* The path we are driving on is already blocked by some other train.
02660    * This can only happen in certain situations when mixing path and
02661    * block signals or when changing tracks and/or signals.
02662    * Exit here as doing any further reservations will probably just
02663    * make matters worse. */
02664   if (other_train != NULL && other_train->index != v->index) {
02665     if (mark_as_stuck) MarkTrainAsStuck(v);
02666     return false;
02667   }
02668   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02669   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02670     /* Can't be stuck then. */
02671     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02672     ClrBit(v->flags, VRF_TRAIN_STUCK);
02673     return true;
02674   }
02675 
02676   /* If we are in a depot, tentatively reserve the depot. */
02677   if (v->track == TRACK_BIT_DEPOT) {
02678     SetDepotReservation(v->tile, true);
02679     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02680   }
02681 
02682   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02683   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02684   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02685 
02686   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02687 
02688   bool res_made = false;
02689   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02690 
02691   if (!res_made) {
02692     /* Free the depot reservation as well. */
02693     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02694     return false;
02695   }
02696 
02697   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02698     v->wait_counter = 0;
02699     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02700   }
02701   ClrBit(v->flags, VRF_TRAIN_STUCK);
02702   return true;
02703 }
02704 
02705 
02706 static bool CheckReverseTrain(const Train *v)
02707 {
02708   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02709       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02710       !(v->direction & 1)) {
02711     return false;
02712   }
02713 
02714   assert(v->track != TRACK_BIT_NONE);
02715 
02716   switch (_settings_game.pf.pathfinder_for_trains) {
02717     case VPF_NPF: return NPFTrainCheckReverse(v);
02718     case VPF_YAPF: return YapfTrainCheckReverse(v);
02719 
02720     default: NOT_REACHED();
02721   }
02722 }
02723 
02729 TileIndex Train::GetOrderStationLocation(StationID station)
02730 {
02731   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02732 
02733   const Station *st = Station::Get(station);
02734   if (!(st->facilities & FACIL_TRAIN)) {
02735     /* The destination station has no trainstation tiles. */
02736     this->IncrementRealOrderIndex();
02737     return 0;
02738   }
02739 
02740   return st->xy;
02741 }
02742 
02744 void Train::MarkDirty()
02745 {
02746   Train *v = this;
02747   do {
02748     v->UpdateViewport(false, false);
02749   } while ((v = v->Next()) != NULL);
02750 
02751   /* need to update acceleration and cached values since the goods on the train changed. */
02752   this->CargoChanged();
02753   this->UpdateAcceleration();
02754 }
02755 
02763 int Train::UpdateSpeed()
02764 {
02765   switch (_settings_game.vehicle.train_acceleration_model) {
02766     default: NOT_REACHED();
02767     case AM_ORIGINAL:
02768       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, this->gcache.cached_max_track_speed);
02769 
02770     case AM_REALISTIC:
02771       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02772   }
02773 }
02774 
02780 static void TrainEnterStation(Train *v, StationID station)
02781 {
02782   v->last_station_visited = station;
02783 
02784   /* check if a train ever visited this station before */
02785   Station *st = Station::Get(station);
02786   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02787     st->had_vehicle_of_type |= HVOT_TRAIN;
02788     SetDParam(0, st->index);
02789     AddVehicleNewsItem(
02790       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02791       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
02792       v->index,
02793       st->index
02794     );
02795     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02796     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02797   }
02798 
02799   v->force_proceed = TFP_NONE;
02800   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02801 
02802   v->BeginLoading();
02803 
02804   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02805 }
02806 
02807 /* Check if the vehicle is compatible with the specified tile */
02808 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02809 {
02810   return IsTileOwner(tile, v->owner) &&
02811       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02812 }
02813 
02815 struct RailtypeSlowdownParams {
02816   byte small_turn; 
02817   byte large_turn; 
02818   byte z_up;       
02819   byte z_down;     
02820 };
02821 
02823 static const RailtypeSlowdownParams _railtype_slowdown[] = {
02824   /* normal accel */
02825   {256 / 4, 256 / 2, 256 / 4, 2}, 
02826   {256 / 4, 256 / 2, 256 / 4, 2}, 
02827   {256 / 4, 256 / 2, 256 / 4, 2}, 
02828   {0,       256 / 2, 256 / 4, 2}, 
02829 };
02830 
02836 static inline void AffectSpeedByZChange(Train *v, int old_z)
02837 {
02838   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02839 
02840   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
02841 
02842   if (old_z < v->z_pos) {
02843     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
02844   } else {
02845     uint16 spd = v->cur_speed + rsp->z_down;
02846     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02847   }
02848 }
02849 
02850 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02851 {
02852   if (IsTileType(tile, MP_RAILWAY) &&
02853       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02854     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02855     Trackdir trackdir = FindFirstTrackdir(tracks);
02856     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02857       /* A PBS block with a non-PBS signal facing us? */
02858       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02859     }
02860   }
02861   return false;
02862 }
02863 
02865 void Train::ReserveTrackUnderConsist() const
02866 {
02867   for (const Train *u = this; u != NULL; u = u->Next()) {
02868     switch (u->track) {
02869       case TRACK_BIT_WORMHOLE:
02870         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02871         break;
02872       case TRACK_BIT_DEPOT:
02873         break;
02874       default:
02875         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02876         break;
02877     }
02878   }
02879 }
02880 
02887 uint Train::Crash(bool flooded)
02888 {
02889   uint pass = 0;
02890   if (this->IsFrontEngine()) {
02891     pass += 2; // driver
02892 
02893     /* Remove the reserved path in front of the train if it is not stuck.
02894      * Also clear all reserved tracks the train is currently on. */
02895     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02896     for (const Train *v = this; v != NULL; v = v->Next()) {
02897       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02898       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02899         /* ClearPathReservation will not free the wormhole exit
02900          * if the train has just entered the wormhole. */
02901         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02902       }
02903     }
02904 
02905     /* we may need to update crossing we were approaching,
02906      * but must be updated after the train has been marked crashed */
02907     TileIndex crossing = TrainApproachingCrossingTile(this);
02908     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02909 
02910     /* Remove the loading indicators (if any) */
02911     HideFillingPercent(&this->fill_percent_te_id);
02912   }
02913 
02914   pass += this->GroundVehicleBase::Crash(flooded);
02915 
02916   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02917   return pass;
02918 }
02919 
02926 static uint TrainCrashed(Train *v)
02927 {
02928   uint num = 0;
02929 
02930   /* do not crash train twice */
02931   if (!(v->vehstatus & VS_CRASHED)) {
02932     num = v->Crash();
02933     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02934     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02935   }
02936 
02937   /* Try to re-reserve track under already crashed train too.
02938    * Crash() clears the reservation! */
02939   v->ReserveTrackUnderConsist();
02940 
02941   return num;
02942 }
02943 
02945 struct TrainCollideChecker {
02946   Train *v; 
02947   uint num; 
02948 };
02949 
02956 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02957 {
02958   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02959 
02960   /* not a train or in depot */
02961   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02962 
02963   /* do not crash into trains of another company. */
02964   if (v->owner != tcc->v->owner) return NULL;
02965 
02966   /* get first vehicle now to make most usual checks faster */
02967   Train *coll = Train::From(v)->First();
02968 
02969   /* can't collide with own wagons */
02970   if (coll == tcc->v) return NULL;
02971 
02972   int x_diff = v->x_pos - tcc->v->x_pos;
02973   int y_diff = v->y_pos - tcc->v->y_pos;
02974 
02975   /* Do fast calculation to check whether trains are not in close vicinity
02976    * and quickly reject trains distant enough for any collision.
02977    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02978    * Differences are then ORed and then we check for any higher bits */
02979   uint hash = (y_diff + 7) | (x_diff + 7);
02980   if (hash & ~15) return NULL;
02981 
02982   /* Slower check using multiplication */
02983   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02984   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02985 
02986   /* Happens when there is a train under bridge next to bridge head */
02987   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02988 
02989   /* crash both trains */
02990   tcc->num += TrainCrashed(tcc->v);
02991   tcc->num += TrainCrashed(coll);
02992 
02993   return NULL; // continue searching
02994 }
02995 
03003 static bool CheckTrainCollision(Train *v)
03004 {
03005   /* can't collide in depot */
03006   if (v->track == TRACK_BIT_DEPOT) return false;
03007 
03008   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03009 
03010   TrainCollideChecker tcc;
03011   tcc.v = v;
03012   tcc.num = 0;
03013 
03014   /* find colliding vehicles */
03015   if (v->track == TRACK_BIT_WORMHOLE) {
03016     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03017     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03018   } else {
03019     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03020   }
03021 
03022   /* any dead -> no crash */
03023   if (tcc.num == 0) return false;
03024 
03025   SetDParam(0, tcc.num);
03026   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH,
03027     NS_ACCIDENT,
03028     v->index
03029   );
03030 
03031   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03032   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03033   return true;
03034 }
03035 
03036 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03037 {
03038   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03039 
03040   Train *t = Train::From(v);
03041   DiagDirection exitdir = *(DiagDirection *)data;
03042 
03043   /* not front engine of a train, inside wormhole or depot, crashed */
03044   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03045 
03046   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03047 
03048   return t;
03049 }
03050 
03058 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03059 {
03060   Train *first = v->First();
03061   Train *prev;
03062   bool direction_changed = false; // has direction of any part changed?
03063 
03064   /* For every vehicle after and including the given vehicle */
03065   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03066     DiagDirection enterdir = DIAGDIR_BEGIN;
03067     bool update_signals_crossing = false; // will we update signals or crossing state?
03068 
03069     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03070     if (v->track != TRACK_BIT_WORMHOLE) {
03071       /* Not inside tunnel */
03072       if (gp.old_tile == gp.new_tile) {
03073         /* Staying in the old tile */
03074         if (v->track == TRACK_BIT_DEPOT) {
03075           /* Inside depot */
03076           gp.x = v->x_pos;
03077           gp.y = v->y_pos;
03078         } else {
03079           /* Not inside depot */
03080 
03081           /* Reverse when we are at the end of the track already, do not move to the new position */
03082           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03083 
03084           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03085           if (HasBit(r, VETS_CANNOT_ENTER)) {
03086             goto invalid_rail;
03087           }
03088           if (HasBit(r, VETS_ENTERED_STATION)) {
03089             /* The new position is the end of the platform */
03090             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03091           }
03092         }
03093       } else {
03094         /* A new tile is about to be entered. */
03095 
03096         /* Determine what direction we're entering the new tile from */
03097         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03098         assert(IsValidDiagDirection(enterdir));
03099 
03100         /* Get the status of the tracks in the new tile and mask
03101          * away the bits that aren't reachable. */
03102         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03103         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03104 
03105         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03106         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03107 
03108         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03109         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03110           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03111            * can be switched on halfway a turn */
03112           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03113         }
03114 
03115         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03116 
03117         /* Check if the new tile constrains tracks that are compatible
03118          * with the current train, if not, bail out. */
03119         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03120 
03121         TrackBits chosen_track;
03122         if (prev == NULL) {
03123           /* Currently the locomotive is active. Determine which one of the
03124            * available tracks to choose */
03125           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03126           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03127 
03128           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03129             /* For each signal we find decrease the counter by one.
03130              * We start at two, so the first signal we pass decreases
03131              * this to one, then if we reach the next signal it is
03132              * decreased to zero and we won't pass that new signal. */
03133             Trackdir dir = FindFirstTrackdir(trackdirbits);
03134             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03135                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03136               /* However, we do not want to be stopped by PBS signals
03137                * entered via the back. */
03138               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03139               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03140             }
03141           }
03142 
03143           /* Check if it's a red signal and that force proceed is not clicked. */
03144           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03145             /* In front of a red signal */
03146             Trackdir i = FindFirstTrackdir(trackdirbits);
03147 
03148             /* Don't handle stuck trains here. */
03149             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03150 
03151             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03152               v->cur_speed = 0;
03153               v->subspeed = 0;
03154               v->progress = 255 - 100;
03155               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03156             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03157               v->cur_speed = 0;
03158               v->subspeed = 0;
03159               v->progress = 255 - 10;
03160               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03161                 DiagDirection exitdir = TrackdirToExitdir(i);
03162                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03163 
03164                 exitdir = ReverseDiagDir(exitdir);
03165 
03166                 /* check if a train is waiting on the other side */
03167                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03168               }
03169             }
03170 
03171             /* If we would reverse but are currently in a PBS block and
03172              * reversing of stuck trains is disabled, don't reverse.
03173              * This does not apply if the reason for reversing is a one-way
03174              * signal blocking us, because a train would then be stuck forever. */
03175             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03176                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03177               v->wait_counter = 0;
03178               return false;
03179             }
03180             goto reverse_train_direction;
03181           } else {
03182             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03183           }
03184         } else {
03185           /* The wagon is active, simply follow the prev vehicle. */
03186           if (prev->tile == gp.new_tile) {
03187             /* Choose the same track as prev */
03188             if (prev->track == TRACK_BIT_WORMHOLE) {
03189               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03190                * However, just choose the track into the wormhole. */
03191               assert(IsTunnel(prev->tile));
03192               chosen_track = bits;
03193             } else {
03194               chosen_track = prev->track;
03195             }
03196           } else {
03197             /* Choose the track that leads to the tile where prev is.
03198              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03199              * I.e. when the tile between them has only space for a single vehicle like
03200              *  1) horizontal/vertical track tiles and
03201              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03202              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03203              */
03204             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03205               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03206               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03207               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03208               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03209             };
03210             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03211             assert(IsValidDiagDirection(exitdir));
03212             chosen_track = _connecting_track[enterdir][exitdir];
03213           }
03214           chosen_track &= bits;
03215         }
03216 
03217         /* Make sure chosen track is a valid track */
03218         assert(
03219             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03220             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03221             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03222 
03223         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03224         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03225         gp.x = (gp.x & ~0xF) | b[0];
03226         gp.y = (gp.y & ~0xF) | b[1];
03227         Direction chosen_dir = (Direction)b[2];
03228 
03229         /* Call the landscape function and tell it that the vehicle entered the tile */
03230         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03231         if (HasBit(r, VETS_CANNOT_ENTER)) {
03232           goto invalid_rail;
03233         }
03234 
03235         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03236           Track track = FindFirstTrack(chosen_track);
03237           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03238           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03239             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03240             MarkTileDirtyByTile(gp.new_tile);
03241           }
03242 
03243           /* Clear any track reservation when the last vehicle leaves the tile */
03244           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03245 
03246           v->tile = gp.new_tile;
03247 
03248           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03249             v->First()->RailtypeChanged();
03250           }
03251 
03252           v->track = chosen_track;
03253           assert(v->track);
03254         }
03255 
03256         /* We need to update signal status, but after the vehicle position hash
03257          * has been updated by UpdateInclination() */
03258         update_signals_crossing = true;
03259 
03260         if (chosen_dir != v->direction) {
03261           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03262             const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
03263             DirDiff diff = DirDifference(v->direction, chosen_dir);
03264             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03265           }
03266           direction_changed = true;
03267           v->direction = chosen_dir;
03268         }
03269 
03270         if (v->IsFrontEngine()) {
03271           v->wait_counter = 0;
03272 
03273           /* If we are approaching a crossing that is reserved, play the sound now. */
03274           TileIndex crossing = TrainApproachingCrossingTile(v);
03275           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03276 
03277           /* Always try to extend the reservation when entering a tile. */
03278           CheckNextTrainTile(v);
03279         }
03280 
03281         if (HasBit(r, VETS_ENTERED_STATION)) {
03282           /* The new position is the location where we want to stop */
03283           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03284         }
03285       }
03286     } else {
03287       /* In a tunnel or on a bridge
03288        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03289        * - for bridges, only the middle part - without the bridge heads */
03290       if (!(v->vehstatus & VS_HIDDEN)) {
03291         Train *first = v->First();
03292         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03293       }
03294 
03295       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03296         /* Perform look-ahead on tunnel exit. */
03297         if (v->IsFrontEngine()) {
03298           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03299           CheckNextTrainTile(v);
03300         }
03301         /* Prevent v->UpdateInclination() being called with wrong parameters.
03302          * This could happen if the train was reversed inside the tunnel/bridge. */
03303         if (gp.old_tile == gp.new_tile) {
03304           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03305         }
03306       } else {
03307         v->x_pos = gp.x;
03308         v->y_pos = gp.y;
03309         VehicleUpdatePosition(v);
03310         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03311         continue;
03312       }
03313     }
03314 
03315     /* update image of train, as well as delta XY */
03316     v->UpdateDeltaXY(v->direction);
03317 
03318     v->x_pos = gp.x;
03319     v->y_pos = gp.y;
03320     VehicleUpdatePosition(v);
03321 
03322     /* update the Z position of the vehicle */
03323     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03324 
03325     if (prev == NULL) {
03326       /* This is the first vehicle in the train */
03327       AffectSpeedByZChange(v, old_z);
03328     }
03329 
03330     if (update_signals_crossing) {
03331       if (v->IsFrontEngine()) {
03332         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03333           /* We are entering a block with PBS signals right now, but
03334            * not through a PBS signal. This means we don't have a
03335            * reservation right now. As a conventional signal will only
03336            * ever be green if no other train is in the block, getting
03337            * a path should always be possible. If the player built
03338            * such a strange network that it is not possible, the train
03339            * will be marked as stuck and the player has to deal with
03340            * the problem. */
03341           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03342               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03343               !TryPathReserve(v)) {
03344             MarkTrainAsStuck(v);
03345           }
03346         }
03347       }
03348 
03349       /* Signals can only change when the first
03350        * (above) or the last vehicle moves. */
03351       if (v->Next() == NULL) {
03352         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03353         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03354       }
03355     }
03356 
03357     /* Do not check on every tick to save some computing time. */
03358     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03359   }
03360 
03361   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03362 
03363   return true;
03364 
03365 invalid_rail:
03366   /* We've reached end of line?? */
03367   if (prev != NULL) error("Disconnecting train");
03368 
03369 reverse_train_direction:
03370   if (reverse) {
03371     v->wait_counter = 0;
03372     v->cur_speed = 0;
03373     v->subspeed = 0;
03374     ReverseTrainDirection(v);
03375   }
03376 
03377   return false;
03378 }
03379 
03386 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03387 {
03388   TrackBits *trackbits = (TrackBits *)data;
03389 
03390   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03391     TrackBits train_tbits = Train::From(v)->track;
03392     if (train_tbits == TRACK_BIT_WORMHOLE) {
03393       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03394       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03395     } else if (train_tbits != TRACK_BIT_DEPOT) {
03396       *trackbits |= train_tbits;
03397     }
03398   }
03399 
03400   return NULL;
03401 }
03402 
03410 static void DeleteLastWagon(Train *v)
03411 {
03412   Train *first = v->First();
03413 
03414   /* Go to the last wagon and delete the link pointing there
03415    * *u is then the one-before-last wagon, and *v the last
03416    * one which will physically be removed */
03417   Train *u = v;
03418   for (; v->Next() != NULL; v = v->Next()) u = v;
03419   u->SetNext(NULL);
03420 
03421   if (first != v) {
03422     /* Recalculate cached train properties */
03423     first->ConsistChanged(false);
03424     /* Update the depot window if the first vehicle is in depot -
03425      * if v == first, then it is updated in PreDestructor() */
03426     if (first->track == TRACK_BIT_DEPOT) {
03427       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03428     }
03429   }
03430 
03431   /* 'v' shouldn't be accessed after it has been deleted */
03432   TrackBits trackbits = v->track;
03433   TileIndex tile = v->tile;
03434   Owner owner = v->owner;
03435 
03436   delete v;
03437   v = NULL; // make sure nobody will try to read 'v' anymore
03438 
03439   if (trackbits == TRACK_BIT_WORMHOLE) {
03440     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03441     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03442   }
03443 
03444   Track track = TrackBitsToTrack(trackbits);
03445   if (HasReservedTracks(tile, trackbits)) {
03446     UnreserveRailTrack(tile, track);
03447 
03448     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03449     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03450     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03451 
03452     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03453     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03454     Track t;
03455     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03456   }
03457 
03458   /* check if the wagon was on a road/rail-crossing */
03459   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03460 
03461   /* Update signals */
03462   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03463     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03464   } else {
03465     SetSignalsOnBothDir(tile, track, owner);
03466   }
03467 }
03468 
03473 static void ChangeTrainDirRandomly(Train *v)
03474 {
03475   static const DirDiff delta[] = {
03476     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03477   };
03478 
03479   do {
03480     /* We don't need to twist around vehicles if they're not visible */
03481     if (!(v->vehstatus & VS_HIDDEN)) {
03482       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03483       v->UpdateDeltaXY(v->direction);
03484       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03485       /* Refrain from updating the z position of the vehicle when on
03486        * a bridge, because UpdateInclination() will put the vehicle under
03487        * the bridge in that case */
03488       if (v->track != TRACK_BIT_WORMHOLE) {
03489         VehicleUpdatePosition(v);
03490         v->UpdateInclination(false, false);
03491       }
03492     }
03493   } while ((v = v->Next()) != NULL);
03494 }
03495 
03501 static bool HandleCrashedTrain(Train *v)
03502 {
03503   int state = ++v->crash_anim_pos;
03504 
03505   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03506     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03507   }
03508 
03509   uint32 r;
03510   if (state <= 200 && Chance16R(1, 7, r)) {
03511     int index = (r * 10 >> 16);
03512 
03513     Vehicle *u = v;
03514     do {
03515       if (--index < 0) {
03516         r = Random();
03517 
03518         CreateEffectVehicleRel(u,
03519           GB(r,  8, 3) + 2,
03520           GB(r, 16, 3) + 2,
03521           GB(r,  0, 3) + 5,
03522           EV_EXPLOSION_SMALL);
03523         break;
03524       }
03525     } while ((u = u->Next()) != NULL);
03526   }
03527 
03528   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03529 
03530   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03531     bool ret = v->Next() != NULL;
03532     DeleteLastWagon(v);
03533     return ret;
03534   }
03535 
03536   return true;
03537 }
03538 
03540 static const uint16 _breakdown_speeds[16] = {
03541   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03542 };
03543 
03544 
03553 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03554 {
03555   /* Calc position within the current tile */
03556   uint x = v->x_pos & 0xF;
03557   uint y = v->y_pos & 0xF;
03558 
03559   /* for diagonal directions, 'x' will be 0..15 -
03560    * for other directions, it will be 1, 3, 5, ..., 15 */
03561   switch (v->direction) {
03562     case DIR_N : x = ~x + ~y + 25; break;
03563     case DIR_NW: x = y;            // FALL THROUGH
03564     case DIR_NE: x = ~x + 16;      break;
03565     case DIR_E : x = ~x + y + 9;   break;
03566     case DIR_SE: x = y;            break;
03567     case DIR_S : x = x + y - 7;    break;
03568     case DIR_W : x = ~y + x + 9;   break;
03569     default: break;
03570   }
03571 
03572   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03573    * does not cross the tile boundary when we do reverse, but as the vehicle's
03574    * location is based on their center, use half a vehicle's length as offset.
03575    * Multiply the half-length by two for straight directions to compensate that
03576    * we only get odd x offsets there. */
03577   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03578     /* we are too near the tile end, reverse now */
03579     v->cur_speed = 0;
03580     if (reverse) ReverseTrainDirection(v);
03581     return false;
03582   }
03583 
03584   /* slow down */
03585   v->vehstatus |= VS_TRAIN_SLOWING;
03586   uint16 break_speed = _breakdown_speeds[x & 0xF];
03587   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03588 
03589   return true;
03590 }
03591 
03592 
03598 static bool TrainCanLeaveTile(const Train *v)
03599 {
03600   /* Exit if inside a tunnel/bridge or a depot */
03601   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03602 
03603   TileIndex tile = v->tile;
03604 
03605   /* entering a tunnel/bridge? */
03606   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03607     DiagDirection dir = GetTunnelBridgeDirection(tile);
03608     if (DiagDirToDir(dir) == v->direction) return false;
03609   }
03610 
03611   /* entering a depot? */
03612   if (IsRailDepotTile(tile)) {
03613     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03614     if (DiagDirToDir(dir) == v->direction) return false;
03615   }
03616 
03617   return true;
03618 }
03619 
03620 
03628 static TileIndex TrainApproachingCrossingTile(const Train *v)
03629 {
03630   assert(v->IsFrontEngine());
03631   assert(!(v->vehstatus & VS_CRASHED));
03632 
03633   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03634 
03635   DiagDirection dir = TrainExitDir(v->direction, v->track);
03636   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03637 
03638   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03639   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03640       !CheckCompatibleRail(v, tile)) {
03641     return INVALID_TILE;
03642   }
03643 
03644   return tile;
03645 }
03646 
03647 
03655 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03656 {
03657   /* First, handle broken down train */
03658 
03659   int t = v->breakdown_ctr;
03660   if (t > 1) {
03661     v->vehstatus |= VS_TRAIN_SLOWING;
03662 
03663     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03664     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03665   } else {
03666     v->vehstatus &= ~VS_TRAIN_SLOWING;
03667   }
03668 
03669   if (!TrainCanLeaveTile(v)) return true;
03670 
03671   /* Determine the non-diagonal direction in which we will exit this tile */
03672   DiagDirection dir = TrainExitDir(v->direction, v->track);
03673   /* Calculate next tile */
03674   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03675 
03676   /* Determine the track status on the next tile */
03677   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03678   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03679 
03680   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03681   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03682 
03683   /* We are sure the train is not entering a depot, it is detected above */
03684 
03685   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03686   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03687   if (_settings_game.pf.forbid_90_deg) {
03688     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03689   }
03690 
03691   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03692   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03693     return TrainApproachingLineEnd(v, false, reverse);
03694   }
03695 
03696   /* approaching red signal */
03697   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03698 
03699   /* approaching a rail/road crossing? then make it red */
03700   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03701 
03702   return true;
03703 }
03704 
03705 
03706 static bool TrainLocoHandler(Train *v, bool mode)
03707 {
03708   /* train has crashed? */
03709   if (v->vehstatus & VS_CRASHED) {
03710     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03711   }
03712 
03713   if (v->force_proceed != TFP_NONE) {
03714     ClrBit(v->flags, VRF_TRAIN_STUCK);
03715     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03716   }
03717 
03718   /* train is broken down? */
03719   if (v->HandleBreakdown()) return true;
03720 
03721   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03722     ReverseTrainDirection(v);
03723   }
03724 
03725   /* exit if train is stopped */
03726   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03727 
03728   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03729   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03730     v->wait_counter = 0;
03731     v->cur_speed = 0;
03732     v->subspeed = 0;
03733     ClrBit(v->flags, VRF_LEAVING_STATION);
03734     ReverseTrainDirection(v);
03735     return true;
03736   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03737     /* Try to reserve a path when leaving the station as we
03738      * might not be marked as wanting a reservation, e.g.
03739      * when an overlength train gets turned around in a station. */
03740     DiagDirection dir = TrainExitDir(v->direction, v->track);
03741     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03742 
03743     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03744       TryPathReserve(v, true, true);
03745     }
03746     ClrBit(v->flags, VRF_LEAVING_STATION);
03747   }
03748 
03749   v->HandleLoading(mode);
03750 
03751   if (v->current_order.IsType(OT_LOADING)) return true;
03752 
03753   if (CheckTrainStayInDepot(v)) return true;
03754 
03755   if (!mode) v->ShowVisualEffect();
03756 
03757   /* We had no order but have an order now, do look ahead. */
03758   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03759     CheckNextTrainTile(v);
03760   }
03761 
03762   /* Handle stuck trains. */
03763   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03764     ++v->wait_counter;
03765 
03766     /* Should we try reversing this tick if still stuck? */
03767     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03768 
03769     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03770     if (!TryPathReserve(v)) {
03771       /* Still stuck. */
03772       if (turn_around) ReverseTrainDirection(v);
03773 
03774       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03775         /* Show message to player. */
03776         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03777           SetDParam(0, v->index);
03778           AddVehicleNewsItem(
03779             STR_NEWS_TRAIN_IS_STUCK,
03780             NS_ADVICE,
03781             v->index
03782           );
03783         }
03784         v->wait_counter = 0;
03785       }
03786       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03787       if (v->force_proceed == TFP_NONE) return true;
03788       ClrBit(v->flags, VRF_TRAIN_STUCK);
03789       v->wait_counter = 0;
03790       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03791     }
03792   }
03793 
03794   if (v->current_order.IsType(OT_LEAVESTATION)) {
03795     v->current_order.Free();
03796     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03797     return true;
03798   }
03799 
03800   int j = v->UpdateSpeed();
03801 
03802   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03803   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03804     /* If we manually stopped, we're not force-proceeding anymore. */
03805     v->force_proceed = TFP_NONE;
03806     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03807   }
03808 
03809   int adv_spd = v->GetAdvanceDistance();
03810   if (j < adv_spd) {
03811     /* if the vehicle has speed 0, update the last_speed field. */
03812     if (v->cur_speed == 0) v->SetLastSpeed();
03813   } else {
03814     TrainCheckIfLineEnds(v);
03815     /* Loop until the train has finished moving. */
03816     for (;;) {
03817       j -= adv_spd;
03818       TrainController(v, NULL);
03819       /* Don't continue to move if the train crashed. */
03820       if (CheckTrainCollision(v)) break;
03821       /* Determine distance to next map position */
03822       adv_spd = v->GetAdvanceDistance();
03823 
03824       /* No more moving this tick */
03825       if (j < adv_spd || v->cur_speed == 0) break;
03826 
03827       OrderType order_type = v->current_order.GetType();
03828       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03829       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03830             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03831             IsTileType(v->tile, MP_STATION) &&
03832             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03833         ProcessOrders(v);
03834       }
03835     }
03836     v->SetLastSpeed();
03837   }
03838 
03839   for (Train *u = v; u != NULL; u = u->Next()) {
03840     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03841 
03842     u->UpdateViewport(false, false);
03843   }
03844 
03845   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03846 
03847   return true;
03848 }
03849 
03854 Money Train::GetRunningCost() const
03855 {
03856   Money cost = 0;
03857   const Train *v = this;
03858 
03859   do {
03860     const Engine *e = v->GetEngine();
03861     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03862 
03863     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03864     if (cost_factor == 0) continue;
03865 
03866     /* Halve running cost for multiheaded parts */
03867     if (v->IsMultiheaded()) cost_factor /= 2;
03868 
03869     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03870   } while ((v = v->GetNextVehicle()) != NULL);
03871 
03872   return cost;
03873 }
03874 
03879 bool Train::Tick()
03880 {
03881   this->tick_counter++;
03882 
03883   if (this->IsFrontEngine()) {
03884     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03885 
03886     this->current_order_time++;
03887 
03888     if (!TrainLocoHandler(this, false)) return false;
03889 
03890     return TrainLocoHandler(this, true);
03891   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03892     /* Delete flooded standalone wagon chain */
03893     if (++this->crash_anim_pos >= 4400) {
03894       delete this;
03895       return false;
03896     }
03897   }
03898 
03899   return true;
03900 }
03901 
03906 static void CheckIfTrainNeedsService(Train *v)
03907 {
03908   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03909   if (v->IsInDepot()) {
03910     VehicleServiceInDepot(v);
03911     return;
03912   }
03913 
03914   uint max_penalty;
03915   switch (_settings_game.pf.pathfinder_for_trains) {
03916     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03917     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03918     default: NOT_REACHED();
03919   }
03920 
03921   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03922   /* Only go to the depot if it is not too far out of our way. */
03923   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03924     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03925       /* If we were already heading for a depot but it has
03926        * suddenly moved farther away, we continue our normal
03927        * schedule? */
03928       v->current_order.MakeDummy();
03929       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03930     }
03931     return;
03932   }
03933 
03934   DepotID depot = GetDepotIndex(tfdd.tile);
03935 
03936   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03937       v->current_order.GetDestination() != depot &&
03938       !Chance16(3, 16)) {
03939     return;
03940   }
03941 
03942   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03943   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03944   v->dest_tile = tfdd.tile;
03945   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03946 }
03947 
03949 void Train::OnNewDay()
03950 {
03951   AgeVehicle(this);
03952 
03953   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03954 
03955   if (this->IsFrontEngine()) {
03956     CheckVehicleBreakdown(this);
03957 
03958     CheckIfTrainNeedsService(this);
03959 
03960     CheckOrders(this);
03961 
03962     /* update destination */
03963     if (this->current_order.IsType(OT_GOTO_STATION)) {
03964       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03965       if (tile != INVALID_TILE) this->dest_tile = tile;
03966     }
03967 
03968     if (this->running_ticks != 0) {
03969       /* running costs */
03970       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03971 
03972       this->profit_this_year -= cost.GetCost();
03973       this->running_ticks = 0;
03974 
03975       SubtractMoneyFromCompanyFract(this->owner, cost);
03976 
03977       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03978       SetWindowClassesDirty(WC_TRAINS_LIST);
03979     }
03980   }
03981 }
03982 
03987 Trackdir Train::GetVehicleTrackdir() const
03988 {
03989   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03990 
03991   if (this->track == TRACK_BIT_DEPOT) {
03992     /* We'll assume the train is facing outwards */
03993     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03994   }
03995 
03996   if (this->track == TRACK_BIT_WORMHOLE) {
03997     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03998     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03999   }
04000 
04001   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
04002 }