train_cmd.cpp

Go to the documentation of this file.
00001 /* $Id: train_cmd.cpp 23622 2011-12-19 20:59:36Z truebrain $ */
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 "vehicle_gui.h"
00021 #include "newgrf_sound.h"
00022 #include "newgrf_text.h"
00023 #include "group.h"
00024 #include "strings_func.h"
00025 #include "viewport_func.h"
00026 #include "window_func.h"
00027 #include "vehicle_func.h"
00028 #include "sound_func.h"
00029 #include "ai/ai.hpp"
00030 #include "game/game.hpp"
00031 #include "newgrf_station.h"
00032 #include "effectvehicle_func.h"
00033 #include "gamelog.h"
00034 #include "network/network.h"
00035 #include "spritecache.h"
00036 #include "core/random_func.hpp"
00037 #include "company_base.h"
00038 #include "newgrf.h"
00039 #include "order_backup.h"
00040 #include "zoom_func.h"
00041 
00042 #include "table/strings.h"
00043 #include "table/train_cmd.h"
00044 
00045 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00046 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00047 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00048 static TileIndex TrainApproachingCrossingTile(const Train *v);
00049 static void CheckIfTrainNeedsService(Train *v);
00050 static void CheckNextTrainTile(Train *v);
00051 
00052 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00053 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00054 
00055 
00063 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00064 {
00065   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00066 
00067   DiagDirection diagdir = DirToDiagDir(direction);
00068 
00069   /* Determine the diagonal direction in which we will exit this tile */
00070   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00071     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00072   }
00073 
00074   return diagdir;
00075 }
00076 
00077 
00083 byte FreightWagonMult(CargoID cargo)
00084 {
00085   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00086   return _settings_game.vehicle.freight_trains;
00087 }
00088 
00090 void CheckTrainsLengths()
00091 {
00092   const Train *v;
00093   bool first = true;
00094 
00095   FOR_ALL_TRAINS(v) {
00096     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00097       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00098         if (u->track != TRACK_BIT_DEPOT) {
00099           if ((w->track != TRACK_BIT_DEPOT &&
00100               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00101               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00102             SetDParam(0, v->index);
00103             SetDParam(1, v->owner);
00104             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00105 
00106             if (!_networking && first) {
00107               first = false;
00108               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00109             }
00110             /* Break so we warn only once for each train. */
00111             break;
00112           }
00113         }
00114       }
00115     }
00116   }
00117 }
00118 
00123 void Train::RailtypeChanged()
00124 {
00125   for (Train *u = this; u != NULL; u = u->Next()) {
00126     /* The wagon-is-powered-state should not change, so the weight does not change. */
00127     u->UpdateVisualEffect(false);
00128   }
00129   this->PowerChanged();
00130   if (this->IsFrontEngine()) this->UpdateAcceleration();
00131 }
00132 
00139 void Train::ConsistChanged(bool same_length)
00140 {
00141   uint16 max_speed = UINT16_MAX;
00142 
00143   assert(this->IsFrontEngine() || this->IsFreeWagon());
00144 
00145   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00146   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00147   this->gcache.cached_total_length = 0;
00148   this->compatible_railtypes = RAILTYPES_NONE;
00149 
00150   bool train_can_tilt = true;
00151 
00152   for (Train *u = this; u != NULL; u = u->Next()) {
00153     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00154 
00155     /* Check the this->first cache. */
00156     assert(u->First() == this);
00157 
00158     /* update the 'first engine' */
00159     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00160     u->railtype = rvi_u->railtype;
00161 
00162     if (u->IsEngine()) first_engine = u->engine_type;
00163 
00164     /* Set user defined data to its default value */
00165     u->tcache.user_def_data = rvi_u->user_def_data;
00166     this->InvalidateNewGRFCache();
00167     u->InvalidateNewGRFCache();
00168   }
00169 
00170   for (Train *u = this; u != NULL; u = u->Next()) {
00171     /* Update user defined data (must be done before other properties) */
00172     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00173     this->InvalidateNewGRFCache();
00174     u->InvalidateNewGRFCache();
00175   }
00176 
00177   for (Train *u = this; u != NULL; u = u->Next()) {
00178     const Engine *e_u = u->GetEngine();
00179     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00180 
00181     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00182 
00183     /* Cache wagon override sprite group. NULL is returned if there is none */
00184     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00185 
00186     /* Reset colour map */
00187     u->colourmap = PAL_NONE;
00188 
00189     /* Update powered-wagon-status and visual effect */
00190     u->UpdateVisualEffect(true);
00191 
00192     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00193         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00194       /* wagon is powered */
00195       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00196     } else {
00197       ClrBit(u->flags, VRF_POWEREDWAGON);
00198     }
00199 
00200     if (!u->IsArticulatedPart()) {
00201       /* Do not count powered wagons for the compatible railtypes, as wagons always
00202          have railtype normal */
00203       if (rvi_u->power > 0) {
00204         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00205       }
00206 
00207       /* Some electric engines can be allowed to run on normal rail. It happens to all
00208        * existing electric engines when elrails are disabled and then re-enabled */
00209       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00210         u->railtype = RAILTYPE_RAIL;
00211         u->compatible_railtypes |= RAILTYPES_RAIL;
00212       }
00213 
00214       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00215       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00216         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00217         if (speed != 0) max_speed = min(speed, max_speed);
00218       }
00219     }
00220 
00221     u->cargo_cap = e_u->DetermineCapacity(u);
00222     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00223 
00224     /* check the vehicle length (callback) */
00225     uint16 veh_len = CALLBACK_FAILED;
00226     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00227       /* Use callback 36 */
00228       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00229     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00230       /* Use callback 11 */
00231       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00232     }
00233     if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00234       ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00235     }
00236     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00237     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00238 
00239     /* verify length hasn't changed */
00240     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00241 
00242     /* update vehicle length? */
00243     if (!same_length) u->gcache.cached_veh_length = veh_len;
00244 
00245     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00246     this->InvalidateNewGRFCache();
00247     u->InvalidateNewGRFCache();
00248   }
00249 
00250   /* store consist weight/max speed in cache */
00251   this->vcache.cached_max_speed = max_speed;
00252   this->tcache.cached_tilt = train_can_tilt;
00253   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00254 
00255   /* 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) */
00256   this->CargoChanged();
00257 
00258   if (this->IsFrontEngine()) {
00259     this->UpdateAcceleration();
00260     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00261     InvalidateWindowData(WC_VEHICLE_REFIT, this->index);
00262   }
00263 }
00264 
00275 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00276 {
00277   const Station *st = Station::Get(station_id);
00278   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00279   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00280 
00281   /* Default to the middle of the station for stations stops that are not in
00282    * the order list like intermediate stations when non-stop is disabled */
00283   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00284   if (v->gcache.cached_total_length >= *station_length) {
00285     /* The train is longer than the station, make it stop at the far end of the platform */
00286     osl = OSL_PLATFORM_FAR_END;
00287   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00288     osl = v->current_order.GetStopLocation();
00289   }
00290 
00291   /* The stop location of the FRONT! of the train */
00292   int stop;
00293   switch (osl) {
00294     default: NOT_REACHED();
00295 
00296     case OSL_PLATFORM_NEAR_END:
00297       stop = v->gcache.cached_total_length;
00298       break;
00299 
00300     case OSL_PLATFORM_MIDDLE:
00301       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00302       break;
00303 
00304     case OSL_PLATFORM_FAR_END:
00305       stop = *station_length;
00306       break;
00307   }
00308 
00309   /* Subtract half the front vehicle length of the train so we get the real
00310    * stop location of the train. */
00311   return stop - (v->gcache.cached_veh_length + 1) / 2;
00312 }
00313 
00314 
00319 int Train::GetCurveSpeedLimit() const
00320 {
00321   assert(this->First() == this);
00322 
00323   static const int absolute_max_speed = UINT16_MAX;
00324   int max_speed = absolute_max_speed;
00325 
00326   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00327 
00328   int curvecount[2] = {0, 0};
00329 
00330   /* first find the curve speed limit */
00331   int numcurve = 0;
00332   int sum = 0;
00333   int pos = 0;
00334   int lastpos = -1;
00335   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00336     Direction this_dir = u->direction;
00337     Direction next_dir = u->Next()->direction;
00338 
00339     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00340     if (dirdiff == DIRDIFF_SAME) continue;
00341 
00342     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00343     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00344     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00345       if (lastpos != -1) {
00346         numcurve++;
00347         sum += pos - lastpos;
00348         if (pos - lastpos == 1 && max_speed > 88) {
00349           max_speed = 88;
00350         }
00351       }
00352       lastpos = pos;
00353     }
00354 
00355     /* if we have a 90 degree turn, fix the speed limit to 60 */
00356     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00357       max_speed = 61;
00358     }
00359   }
00360 
00361   if (numcurve > 0 && max_speed > 88) {
00362     if (curvecount[0] == 1 && curvecount[1] == 1) {
00363       max_speed = absolute_max_speed;
00364     } else {
00365       sum /= numcurve;
00366       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00367     }
00368   }
00369 
00370   if (max_speed != absolute_max_speed) {
00371     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00372     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00373     max_speed += (max_speed / 2) * rti->curve_speed;
00374 
00375     if (this->tcache.cached_tilt) {
00376       /* Apply max_speed bonus of 20% for a tilting train */
00377       max_speed += max_speed / 5;
00378     }
00379   }
00380 
00381   return max_speed;
00382 }
00383 
00388 int Train::GetCurrentMaxSpeed() const
00389 {
00390   int max_speed = this->tcache.cached_max_curve_speed;
00391   assert(max_speed == this->GetCurveSpeedLimit());
00392 
00393   if (IsRailStationTile(this->tile)) {
00394     StationID sid = GetStationIndex(this->tile);
00395     if (this->current_order.ShouldStopAtStation(this, sid)) {
00396       int station_ahead;
00397       int station_length;
00398       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00399 
00400       /* The distance to go is whatever is still ahead of the train minus the
00401        * distance from the train's stop location to the end of the platform */
00402       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00403 
00404       if (distance_to_go > 0) {
00405         int st_max_speed = 120;
00406 
00407         int delta_v = this->cur_speed / (distance_to_go + 1);
00408         if (max_speed > (this->cur_speed - delta_v)) {
00409           st_max_speed = this->cur_speed - (delta_v / 10);
00410         }
00411 
00412         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00413         max_speed = min(max_speed, st_max_speed);
00414       }
00415     }
00416   }
00417 
00418   for (const Train *u = this; u != NULL; u = u->Next()) {
00419     if (u->track == TRACK_BIT_DEPOT) {
00420       max_speed = min(max_speed, 61);
00421       break;
00422     }
00423   }
00424 
00425   return min(max_speed, this->gcache.cached_max_track_speed);
00426 }
00427 
00428 void Train::UpdateAcceleration()
00429 {
00430   assert(this->IsFrontEngine());
00431 
00432   uint power = this->gcache.cached_power;
00433   uint weight = this->gcache.cached_weight;
00434   assert(weight != 0);
00435   this->acceleration = Clamp(power / weight * 4, 1, 255);
00436 }
00437 
00443 int Train::GetDisplayImageWidth(Point *offset) const
00444 {
00445   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00446   int vehicle_pitch = 0;
00447 
00448   const Engine *e = this->GetEngine();
00449   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00450     reference_width = e->GetGRF()->traininfo_vehicle_width;
00451     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00452   }
00453 
00454   if (offset != NULL) {
00455     offset->x = reference_width / 2;
00456     offset->y = vehicle_pitch;
00457   }
00458   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00459 }
00460 
00461 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00462 {
00463   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00464 }
00465 
00466 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00467 {
00468   uint8 spritenum = this->spritenum;
00469   SpriteID sprite;
00470 
00471   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00472 
00473   if (is_custom_sprite(spritenum)) {
00474     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00475     if (sprite != 0) return sprite;
00476 
00477     spritenum = this->GetEngine()->original_image_index;
00478   }
00479 
00480   sprite = GetDefaultTrainSprite(spritenum, direction);
00481 
00482   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00483 
00484   return sprite;
00485 }
00486 
00487 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00488 {
00489   const Engine *e = Engine::Get(engine);
00490   Direction dir = rear_head ? DIR_E : DIR_W;
00491   uint8 spritenum = e->u.rail.image_index;
00492 
00493   if (is_custom_sprite(spritenum)) {
00494     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00495     if (sprite != 0) {
00496       if (e->GetGRF() != NULL) {
00497         y += e->GetGRF()->traininfo_vehicle_pitch;
00498       }
00499       return sprite;
00500     }
00501 
00502     spritenum = Engine::Get(engine)->original_image_index;
00503   }
00504 
00505   if (rear_head) spritenum++;
00506 
00507   return GetDefaultTrainSprite(spritenum, DIR_W);
00508 }
00509 
00510 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00511 {
00512   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00513     int yf = y;
00514     int yr = y;
00515 
00516     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00517     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00518     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00519     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00520 
00521     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);
00522 
00523     DrawSprite(spritef, pal, preferred_x - 14, yf);
00524     DrawSprite(spriter, pal, preferred_x + 15, yr);
00525   } else {
00526     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00527     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00528     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));
00529     DrawSprite(sprite, pal, preferred_x, y);
00530   }
00531 }
00532 
00541 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00542 {
00543   const RailVehicleInfo *rvi = &e->u.rail;
00544 
00545   /* Check that the wagon can drive on the track in question */
00546   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00547 
00548   if (flags & DC_EXEC) {
00549     Train *v = new Train();
00550     *ret = v;
00551     v->spritenum = rvi->image_index;
00552 
00553     v->engine_type = e->index;
00554     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00555 
00556     DiagDirection dir = GetRailDepotDirection(tile);
00557 
00558     v->direction = DiagDirToDir(dir);
00559     v->tile = tile;
00560 
00561     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00562     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00563 
00564     v->x_pos = x;
00565     v->y_pos = y;
00566     v->z_pos = GetSlopePixelZ(x, y);
00567     v->owner = _current_company;
00568     v->track = TRACK_BIT_DEPOT;
00569     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00570 
00571     v->SetWagon();
00572 
00573     v->SetFreeWagon();
00574     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00575 
00576     v->cargo_type = e->GetDefaultCargoType();
00577     v->cargo_cap = rvi->capacity;
00578 
00579     v->railtype = rvi->railtype;
00580 
00581     v->build_year = _cur_year;
00582     v->cur_image = SPR_IMG_QUERY;
00583     v->random_bits = VehicleRandomBits();
00584 
00585     v->group_id = DEFAULT_GROUP;
00586 
00587     AddArticulatedParts(v);
00588 
00589     _new_vehicle_id = v->index;
00590 
00591     VehicleMove(v, false);
00592     v->First()->ConsistChanged(false);
00593     UpdateTrainGroupID(v->First());
00594 
00595     CheckConsistencyOfArticulatedVehicle(v);
00596 
00597     /* Try to connect the vehicle to one of free chains of wagons. */
00598     Train *w;
00599     FOR_ALL_TRAINS(w) {
00600       if (w->tile == tile &&              
00601           w->IsFreeWagon() &&             
00602           w->engine_type == e->index &&   
00603           w->First() != v &&              
00604           !(w->vehstatus & VS_CRASHED)) { 
00605         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00606         break;
00607       }
00608     }
00609   }
00610 
00611   return CommandCost();
00612 }
00613 
00615 static void NormalizeTrainVehInDepot(const Train *u)
00616 {
00617   const Train *v;
00618   FOR_ALL_TRAINS(v) {
00619     if (v->IsFreeWagon() && v->tile == u->tile &&
00620         v->track == TRACK_BIT_DEPOT) {
00621       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00622           CMD_MOVE_RAIL_VEHICLE).Failed())
00623         break;
00624     }
00625   }
00626 }
00627 
00628 static void AddRearEngineToMultiheadedTrain(Train *v)
00629 {
00630   Train *u = new Train();
00631   v->value >>= 1;
00632   u->value = v->value;
00633   u->direction = v->direction;
00634   u->owner = v->owner;
00635   u->tile = v->tile;
00636   u->x_pos = v->x_pos;
00637   u->y_pos = v->y_pos;
00638   u->z_pos = v->z_pos;
00639   u->track = TRACK_BIT_DEPOT;
00640   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00641   u->spritenum = v->spritenum + 1;
00642   u->cargo_type = v->cargo_type;
00643   u->cargo_subtype = v->cargo_subtype;
00644   u->cargo_cap = v->cargo_cap;
00645   u->railtype = v->railtype;
00646   u->engine_type = v->engine_type;
00647   u->build_year = v->build_year;
00648   u->cur_image = SPR_IMG_QUERY;
00649   u->random_bits = VehicleRandomBits();
00650   v->SetMultiheaded();
00651   u->SetMultiheaded();
00652   v->SetNext(u);
00653   VehicleMove(u, false);
00654 
00655   /* Now we need to link the front and rear engines together */
00656   v->other_multiheaded_part = u;
00657   u->other_multiheaded_part = v;
00658 }
00659 
00669 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00670 {
00671   const RailVehicleInfo *rvi = &e->u.rail;
00672 
00673   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00674 
00675   /* Check if depot and new engine uses the same kind of tracks *
00676    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00677   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00678 
00679   if (flags & DC_EXEC) {
00680     DiagDirection dir = GetRailDepotDirection(tile);
00681     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00682     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00683 
00684     Train *v = new Train();
00685     *ret = v;
00686     v->direction = DiagDirToDir(dir);
00687     v->tile = tile;
00688     v->owner = _current_company;
00689     v->x_pos = x;
00690     v->y_pos = y;
00691     v->z_pos = GetSlopePixelZ(x, y);
00692     v->track = TRACK_BIT_DEPOT;
00693     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00694     v->spritenum = rvi->image_index;
00695     v->cargo_type = e->GetDefaultCargoType();
00696     v->cargo_cap = rvi->capacity;
00697     v->last_station_visited = INVALID_STATION;
00698 
00699     v->engine_type = e->index;
00700     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00701 
00702     v->reliability = e->reliability;
00703     v->reliability_spd_dec = e->reliability_spd_dec;
00704     v->max_age = e->GetLifeLengthInDays();
00705 
00706     v->railtype = rvi->railtype;
00707     _new_vehicle_id = v->index;
00708 
00709     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00710     v->date_of_last_service = _date;
00711     v->build_year = _cur_year;
00712     v->cur_image = SPR_IMG_QUERY;
00713     v->random_bits = VehicleRandomBits();
00714 
00715     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00716 
00717     v->group_id = DEFAULT_GROUP;
00718 
00719     v->SetFrontEngine();
00720     v->SetEngine();
00721 
00722     VehicleMove(v, false);
00723 
00724     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00725       AddRearEngineToMultiheadedTrain(v);
00726     } else {
00727       AddArticulatedParts(v);
00728     }
00729 
00730     v->ConsistChanged(false);
00731     UpdateTrainGroupID(v);
00732 
00733     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00734       NormalizeTrainVehInDepot(v);
00735     }
00736 
00737     CheckConsistencyOfArticulatedVehicle(v);
00738   }
00739 
00740   return CommandCost();
00741 }
00742 
00743 
00744 bool Train::IsInDepot() const
00745 {
00746   /* Is the front engine stationary in the depot? */
00747   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00748 
00749   /* Check whether the rest is also already trying to enter the depot. */
00750   for (const Train *v = this; v != NULL; v = v->Next()) {
00751     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00752   }
00753 
00754   return true;
00755 }
00756 
00757 bool Train::IsStoppedInDepot() const
00758 {
00759   /* Are we stopped? Of course wagons don't really care... */
00760   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00761   return this->IsInDepot();
00762 }
00763 
00764 static Train *FindGoodVehiclePos(const Train *src)
00765 {
00766   EngineID eng = src->engine_type;
00767   TileIndex tile = src->tile;
00768 
00769   Train *dst;
00770   FOR_ALL_TRAINS(dst) {
00771     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00772       /* check so all vehicles in the line have the same engine. */
00773       Train *t = dst;
00774       while (t->engine_type == eng) {
00775         t = t->Next();
00776         if (t == NULL) return dst;
00777       }
00778     }
00779   }
00780 
00781   return NULL;
00782 }
00783 
00785 typedef SmallVector<Train *, 16> TrainList;
00786 
00792 static void MakeTrainBackup(TrainList &list, Train *t)
00793 {
00794   for (; t != NULL; t = t->Next()) *list.Append() = t;
00795 }
00796 
00801 static void RestoreTrainBackup(TrainList &list)
00802 {
00803   /* No train, nothing to do. */
00804   if (list.Length() == 0) return;
00805 
00806   Train *prev = NULL;
00807   /* Iterate over the list and rebuild it. */
00808   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00809     Train *t = *iter;
00810     if (prev != NULL) {
00811       prev->SetNext(t);
00812     } else if (t->Previous() != NULL) {
00813       /* Make sure the head of the train is always the first in the chain. */
00814       t->Previous()->SetNext(NULL);
00815     }
00816     prev = t;
00817   }
00818 }
00819 
00825 static void RemoveFromConsist(Train *part, bool chain = false)
00826 {
00827   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00828 
00829   /* Unlink at the front, but make it point to the next
00830    * vehicle after the to be remove part. */
00831   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00832 
00833   /* Unlink at the back */
00834   tail->SetNext(NULL);
00835 }
00836 
00842 static void InsertInConsist(Train *dst, Train *chain)
00843 {
00844   /* We do not want to add something in the middle of an articulated part. */
00845   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00846 
00847   chain->Last()->SetNext(dst->Next());
00848   dst->SetNext(chain);
00849 }
00850 
00856 static void NormaliseDualHeads(Train *t)
00857 {
00858   for (; t != NULL; t = t->GetNextVehicle()) {
00859     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00860 
00861     /* Make sure that there are no free cars before next engine */
00862     Train *u;
00863     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00864 
00865     if (u == t->other_multiheaded_part) continue;
00866 
00867     /* Remove the part from the 'wrong' train */
00868     RemoveFromConsist(t->other_multiheaded_part);
00869     /* And add it to the 'right' train */
00870     InsertInConsist(u, t->other_multiheaded_part);
00871   }
00872 }
00873 
00878 static void NormaliseSubtypes(Train *chain)
00879 {
00880   /* Nothing to do */
00881   if (chain == NULL) return;
00882 
00883   /* We must be the first in the chain. */
00884   assert(chain->Previous() == NULL);
00885 
00886   /* Set the appropriate bits for the first in the chain. */
00887   if (chain->IsWagon()) {
00888     chain->SetFreeWagon();
00889   } else {
00890     assert(chain->IsEngine());
00891     chain->SetFrontEngine();
00892   }
00893 
00894   /* Now clear the bits for the rest of the chain */
00895   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00896     t->ClearFreeWagon();
00897     t->ClearFrontEngine();
00898   }
00899 }
00900 
00910 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00911 {
00912   /* Just add 'new' engines and subtract the original ones.
00913    * If that's less than or equal to 0 we can be sure we did
00914    * not add any engines (read: trains) along the way. */
00915   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00916       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00917       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00918       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00919     return CommandCost();
00920   }
00921 
00922   /* Get a free unit number and check whether it's within the bounds.
00923    * There will always be a maximum of one new train. */
00924   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00925 
00926   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00927 }
00928 
00934 static CommandCost CheckTrainAttachment(Train *t)
00935 {
00936   /* No multi-part train, no need to check. */
00937   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00938 
00939   /* The maximum length for a train. For each part we decrease this by one
00940    * and if the result is negative the train is simply too long. */
00941   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00942 
00943   Train *head = t;
00944   Train *prev = t;
00945 
00946   /* Break the prev -> t link so it always holds within the loop. */
00947   t = t->Next();
00948   prev->SetNext(NULL);
00949 
00950   /* Make sure the cache is cleared. */
00951   head->InvalidateNewGRFCache();
00952 
00953   while (t != NULL) {
00954     allowed_len -= t->gcache.cached_veh_length;
00955 
00956     Train *next = t->Next();
00957 
00958     /* Unlink the to-be-added piece; it is already unlinked from the previous
00959      * part due to the fact that the prev -> t link is broken. */
00960     t->SetNext(NULL);
00961 
00962     /* Don't check callback for articulated or rear dual headed parts */
00963     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00964       /* Back up and clear the first_engine data to avoid using wagon override group */
00965       EngineID first_engine = t->gcache.first_engine;
00966       t->gcache.first_engine = INVALID_ENGINE;
00967 
00968       /* We don't want the cache to interfere. head's cache is cleared before
00969        * the loop and after each callback does not need to be cleared here. */
00970       t->InvalidateNewGRFCache();
00971 
00972       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00973 
00974       /* Restore original first_engine data */
00975       t->gcache.first_engine = first_engine;
00976 
00977       /* We do not want to remember any cached variables from the test run */
00978       t->InvalidateNewGRFCache();
00979       head->InvalidateNewGRFCache();
00980 
00981       if (callback != CALLBACK_FAILED) {
00982         /* A failing callback means everything is okay */
00983         StringID error = STR_NULL;
00984 
00985         if (t->GetGRF()->grf_version < 8) {
00986           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00987           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00988           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00989         } else {
00990           if (callback < 0x400) {
00991             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00992           } else {
00993             switch (callback) {
00994               case 0x400: // allow if railtypes match (always the case for OpenTTD)
00995               case 0x401: // allow
00996                 break;
00997 
00998               default:    // unknown reason -> disallow
00999               case 0x402: // disallow attaching
01000                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01001                 break;
01002             }
01003           }
01004         }
01005 
01006         if (error != STR_NULL) return_cmd_error(error);
01007       }
01008     }
01009 
01010     /* And link it to the new part. */
01011     prev->SetNext(t);
01012     prev = t;
01013     t = next;
01014   }
01015 
01016   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01017   return CommandCost();
01018 }
01019 
01030 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01031 {
01032   /* Check whether we may actually construct the trains. */
01033   CommandCost ret = CheckTrainAttachment(src);
01034   if (ret.Failed()) return ret;
01035   ret = CheckTrainAttachment(dst);
01036   if (ret.Failed()) return ret;
01037 
01038   /* Check whether we need to build a new train. */
01039   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01040 }
01041 
01050 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01051 {
01052   /* First determine the front of the two resulting trains */
01053   if (*src_head == *dst_head) {
01054     /* If we aren't moving part(s) to a new train, we are just moving the
01055      * front back and there is not destination head. */
01056     *dst_head = NULL;
01057   } else if (*dst_head == NULL) {
01058     /* If we are moving to a new train the head of the move train would become
01059      * the head of the new vehicle. */
01060     *dst_head = src;
01061   }
01062 
01063   if (src == *src_head) {
01064     /* If we are moving the front of a train then we are, in effect, creating
01065      * a new head for the train. Point to that. Unless we are moving the whole
01066      * train in which case there is not 'source' train anymore.
01067      * In case we are a multiheaded part we want the complete thing to come
01068      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01069      * that is followed by a rear multihead we do not want to include that. */
01070     *src_head = move_chain ? NULL :
01071         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01072   }
01073 
01074   /* Now it's just simply removing the part that we are going to move from the
01075    * source train and *if* the destination is a not a new train add the chain
01076    * at the destination location. */
01077   RemoveFromConsist(src, move_chain);
01078   if (*dst_head != src) InsertInConsist(dst, src);
01079 
01080   /* Now normalise the dual heads, that is move the dual heads around in such
01081    * a way that the head and rear of a dual head are in the same train */
01082   NormaliseDualHeads(*src_head);
01083   NormaliseDualHeads(*dst_head);
01084 }
01085 
01091 static void NormaliseTrainHead(Train *head)
01092 {
01093   /* Not much to do! */
01094   if (head == NULL) return;
01095 
01096   /* Tell the 'world' the train changed. */
01097   head->ConsistChanged(false);
01098   UpdateTrainGroupID(head);
01099 
01100   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01101   if (!head->IsFrontEngine()) return;
01102 
01103   /* Update the refit button and window */
01104   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01105   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01106 
01107   /* If we don't have a unit number yet, set one. */
01108   if (head->unitnumber != 0) return;
01109   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01110 }
01111 
01124 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01125 {
01126   VehicleID s = GB(p1, 0, 20);
01127   VehicleID d = GB(p2, 0, 20);
01128   bool move_chain = HasBit(p1, 20);
01129 
01130   Train *src = Train::GetIfValid(s);
01131   if (src == NULL) return CMD_ERROR;
01132 
01133   CommandCost ret = CheckOwnership(src->owner);
01134   if (ret.Failed()) return ret;
01135 
01136   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01137   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01138 
01139   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01140   Train *dst;
01141   if (d == INVALID_VEHICLE) {
01142     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01143   } else {
01144     dst = Train::GetIfValid(d);
01145     if (dst == NULL) return CMD_ERROR;
01146 
01147     CommandCost ret = CheckOwnership(dst->owner);
01148     if (ret.Failed()) return ret;
01149 
01150     /* Do not allow appending to crashed vehicles, too */
01151     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01152   }
01153 
01154   /* if an articulated part is being handled, deal with its parent vehicle */
01155   src = src->GetFirstEnginePart();
01156   if (dst != NULL) {
01157     dst = dst->GetFirstEnginePart();
01158   }
01159 
01160   /* don't move the same vehicle.. */
01161   if (src == dst) return CommandCost();
01162 
01163   /* locate the head of the two chains */
01164   Train *src_head = src->First();
01165   Train *dst_head;
01166   if (dst != NULL) {
01167     dst_head = dst->First();
01168     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01169     /* Now deal with articulated part of destination wagon */
01170     dst = dst->GetLastEnginePart();
01171   } else {
01172     dst_head = NULL;
01173   }
01174 
01175   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01176 
01177   /* When moving all wagons, we can't have the same src_head and dst_head */
01178   if (move_chain && src_head == dst_head) return CommandCost();
01179 
01180   /* When moving a multiheaded part to be place after itself, bail out. */
01181   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01182 
01183   /* Check if all vehicles in the source train are stopped inside a depot. */
01184   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01185 
01186   /* Check if all vehicles in the destination train are stopped inside a depot. */
01187   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01188 
01189   /* First make a backup of the order of the trains. That way we can do
01190    * whatever we want with the order and later on easily revert. */
01191   TrainList original_src;
01192   TrainList original_dst;
01193 
01194   MakeTrainBackup(original_src, src_head);
01195   MakeTrainBackup(original_dst, dst_head);
01196 
01197   /* Also make backup of the original heads as ArrangeTrains can change them.
01198    * For the destination head we do not care if it is the same as the source
01199    * head because in that case it's just a copy. */
01200   Train *original_src_head = src_head;
01201   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01202 
01203   if (flags & DC_EXEC) {
01204     /* Remove old heads from the statistics */
01205     if (original_src_head != NULL && original_src_head->IsFrontEngine()) GroupStatistics::CountVehicle(original_src_head, -1);
01206     if (original_dst_head != NULL && original_dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(original_dst_head, -1);
01207   }
01208 
01209   /* (Re)arrange the trains in the wanted arrangement. */
01210   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01211 
01212   if ((flags & DC_AUTOREPLACE) == 0) {
01213     /* If the autoreplace flag is set we do not need to test for the validity
01214      * because we are going to revert the train to its original state. As we
01215      * assume the original state was correct autoreplace can skip this. */
01216     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01217     if (ret.Failed()) {
01218       /* Restore the train we had. */
01219       RestoreTrainBackup(original_src);
01220       RestoreTrainBackup(original_dst);
01221       return ret;
01222     }
01223   }
01224 
01225   /* do it? */
01226   if (flags & DC_EXEC) {
01227     /* First normalise the sub types of the chains. */
01228     NormaliseSubtypes(src_head);
01229     NormaliseSubtypes(dst_head);
01230 
01231     /* There are 14 different cases:
01232      *  1) front engine gets moved to a new train, it stays a front engine.
01233      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01234      *     b) the 'next' part is an engine that becomes a front engine.
01235      *     c) there is no 'next' part, nothing else happens
01236      *  2) front engine gets moved to another train, it is not a front engine anymore
01237      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01238      *     b) the 'next' part is an engine that becomes a front engine.
01239      *     c) there is no 'next' part, nothing else happens
01240      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01241      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01242      *     b) the 'next' part is an engine that becomes a front engine.
01243      *  4) free wagon gets moved
01244      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01245      *     b) the 'next' part is an engine that becomes a front engine.
01246      *     c) there is no 'next' part, nothing else happens
01247      *  5) non front engine gets moved and becomes a new train, nothing else happens
01248      *  6) non front engine gets moved within a train / to another train, nothing hapens
01249      *  7) wagon gets moved, nothing happens
01250      */
01251     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01252       /* Cases #2 and #3: the front engine gets trashed. */
01253       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01254       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01255       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01256       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01257       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01258       SetWindowDirty(WC_COMPANY, _current_company);
01259 
01260       /* Delete orders, group stuff and the unit number as we're not the
01261        * front of any vehicle anymore. */
01262       DeleteVehicleOrders(src);
01263       RemoveVehicleFromGroup(src);
01264       src->unitnumber = 0;
01265     }
01266 
01267     /* We weren't a front engine but are becoming one. So
01268      * we should be put in the default group. */
01269     if (original_src_head != src && dst_head == src) {
01270       SetTrainGroupID(src, DEFAULT_GROUP);
01271       SetWindowDirty(WC_COMPANY, _current_company);
01272     }
01273 
01274     /* Add new heads to statistics */
01275     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01276     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01277 
01278     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01279     NormaliseTrainHead(src_head);
01280     NormaliseTrainHead(dst_head);
01281 
01282     /* We are undoubtedly changing something in the depot and train list. */
01283     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01284     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01285   } else {
01286     /* We don't want to execute what we're just tried. */
01287     RestoreTrainBackup(original_src);
01288     RestoreTrainBackup(original_dst);
01289   }
01290 
01291   return CommandCost();
01292 }
01293 
01305 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01306 {
01307   /* Check if we deleted a vehicle window */
01308   Window *w = NULL;
01309 
01310   /* Sell a chain of vehicles or not? */
01311   bool sell_chain = HasBit(data, 0);
01312 
01313   Train *v = Train::From(t)->GetFirstEnginePart();
01314   Train *first = v->First();
01315 
01316   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01317 
01318   /* First make a backup of the order of the train. That way we can do
01319    * whatever we want with the order and later on easily revert. */
01320   TrainList original;
01321   MakeTrainBackup(original, first);
01322 
01323   /* We need to keep track of the new head and the head of what we're going to sell. */
01324   Train *new_head = first;
01325   Train *sell_head = NULL;
01326 
01327   /* Split the train in the wanted way. */
01328   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01329 
01330   /* We don't need to validate the second train; it's going to be sold. */
01331   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01332   if (ret.Failed()) {
01333     /* Restore the train we had. */
01334     RestoreTrainBackup(original);
01335     return ret;
01336   }
01337 
01338   CommandCost cost(EXPENSES_NEW_VEHICLES);
01339   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01340 
01341   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01342     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01343   }
01344 
01345   /* do it? */
01346   if (flags & DC_EXEC) {
01347     /* First normalise the sub types of the chain. */
01348     NormaliseSubtypes(new_head);
01349 
01350     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01351       /* We are selling the front engine. In this case we want to
01352        * 'give' the order, unit number and such to the new head. */
01353       new_head->orders.list = first->orders.list;
01354       new_head->AddToShared(first);
01355       DeleteVehicleOrders(first);
01356 
01357       /* Copy other important data from the front engine */
01358       new_head->CopyVehicleConfigAndStatistics(first);
01359       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01360 
01361       /* If we deleted a window then open a new one for the 'new' train */
01362       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01363     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01364       OrderBackup::Backup(v, user);
01365     }
01366 
01367     /* We need to update the information about the train. */
01368     NormaliseTrainHead(new_head);
01369 
01370     /* We are undoubtedly changing something in the depot and train list. */
01371     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01372     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01373 
01374     /* Actually delete the sold 'goods' */
01375     delete sell_head;
01376   } else {
01377     /* We don't want to execute what we're just tried. */
01378     RestoreTrainBackup(original);
01379   }
01380 
01381   return cost;
01382 }
01383 
01384 void Train::UpdateDeltaXY(Direction direction)
01385 {
01386   /* Set common defaults. */
01387   this->x_offs    = -1;
01388   this->y_offs    = -1;
01389   this->x_extent  =  3;
01390   this->y_extent  =  3;
01391   this->z_extent  =  6;
01392   this->x_bb_offs =  0;
01393   this->y_bb_offs =  0;
01394 
01395   if (!IsDiagonalDirection(direction)) {
01396     static const int _sign_table[] =
01397     {
01398       // x, y
01399       -1, -1, // DIR_N
01400       -1,  1, // DIR_E
01401        1,  1, // DIR_S
01402        1, -1, // DIR_W
01403     };
01404 
01405     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01406 
01407     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01408     this->x_offs -= half_shorten * _sign_table[direction];
01409     this->y_offs -= half_shorten * _sign_table[direction + 1];
01410     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01411     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01412   } else {
01413     switch (direction) {
01414         /* Shorten southern corner of the bounding box according the vehicle length
01415          * and center the bounding box on the vehicle. */
01416       case DIR_NE:
01417         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01418         this->x_extent  = this->gcache.cached_veh_length - 1;
01419         this->x_bb_offs = -1;
01420         break;
01421 
01422       case DIR_NW:
01423         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01424         this->y_extent  = this->gcache.cached_veh_length - 1;
01425         this->y_bb_offs = -1;
01426         break;
01427 
01428         /* Move northern corner of the bounding box down according to vehicle length
01429          * and center the bounding box on the vehicle. */
01430       case DIR_SW:
01431         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01432         this->x_extent  = VEHICLE_LENGTH - 1;
01433         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01434         break;
01435 
01436       case DIR_SE:
01437         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01438         this->y_extent  = VEHICLE_LENGTH - 1;
01439         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01440         break;
01441 
01442       default:
01443         NOT_REACHED();
01444     }
01445   }
01446 }
01447 
01449 static void MarkTrainAsStuck(Train *v)
01450 {
01451   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01452     /* It is the first time the problem occurred, set the "train stuck" flag. */
01453     SetBit(v->flags, VRF_TRAIN_STUCK);
01454 
01455     v->wait_counter = 0;
01456 
01457     /* Stop train */
01458     v->cur_speed = 0;
01459     v->subspeed = 0;
01460     v->SetLastSpeed();
01461 
01462     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01463   }
01464 }
01465 
01466 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01467 {
01468   uint16 flag1 = *swap_flag1;
01469   uint16 flag2 = *swap_flag2;
01470 
01471   /* Clear the flags */
01472   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01473   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01474   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01475   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01476 
01477   /* Reverse the rail-flags (if needed) */
01478   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01479     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01480   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01481     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01482   }
01483   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01484     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01485   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01486     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01487   }
01488 }
01489 
01494 static void UpdateStatusAfterSwap(Train *v)
01495 {
01496   /* Reverse the direction. */
01497   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01498 
01499   /* Call the proper EnterTile function unless we are in a wormhole. */
01500   if (v->track != TRACK_BIT_WORMHOLE) {
01501     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01502   } else {
01503     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01504      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01505      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01506      * when we shouldn't have. Check if this is the case. */
01507     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01508     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01509       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01510       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01511         /* We have just left the wormhole, possibly set the
01512          * "goingdown" bit. UpdateInclination() can be used
01513          * because we are at the border of the tile. */
01514         v->UpdateInclination(true, true);
01515         return;
01516       }
01517     }
01518   }
01519 
01520   v->UpdateViewport(true, true);
01521 }
01522 
01523 void ReverseTrainSwapVeh(Train *v, int l, int r)
01524 {
01525   Train *a, *b;
01526 
01527   /* locate vehicles to swap */
01528   for (a = v; l != 0; l--) a = a->Next();
01529   for (b = v; r != 0; r--) b = b->Next();
01530 
01531   if (a != b) {
01532     /* swap the hidden bits */
01533     {
01534       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01535       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01536       a->vehstatus = tmp;
01537     }
01538 
01539     Swap(a->track, b->track);
01540     Swap(a->direction, b->direction);
01541     Swap(a->x_pos, b->x_pos);
01542     Swap(a->y_pos, b->y_pos);
01543     Swap(a->tile,  b->tile);
01544     Swap(a->z_pos, b->z_pos);
01545 
01546     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01547 
01548     UpdateStatusAfterSwap(a);
01549     UpdateStatusAfterSwap(b);
01550   } else {
01551     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01552      * This is a little bit redundant way, a->gv_flags will
01553      * be (re)set twice, but it reduces code duplication */
01554     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01555     UpdateStatusAfterSwap(a);
01556   }
01557 
01558   /* Update power of the train in case tiles were different rail type. */
01559   v->RailtypeChanged();
01560 }
01561 
01562 
01568 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01569 {
01570   return (v->type == VEH_TRAIN) ? v : NULL;
01571 }
01572 
01573 
01580 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01581 {
01582   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01583 
01584   Train *t = Train::From(v);
01585   if (!t->IsFrontEngine()) return NULL;
01586 
01587   TileIndex tile = *(TileIndex *)data;
01588 
01589   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01590 
01591   return t;
01592 }
01593 
01594 
01601 static bool TrainApproachingCrossing(TileIndex tile)
01602 {
01603   assert(IsLevelCrossingTile(tile));
01604 
01605   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01606   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01607 
01608   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01609 
01610   dir = ReverseDiagDir(dir);
01611   tile_from = tile + TileOffsByDiagDir(dir);
01612 
01613   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01614 }
01615 
01616 
01623 void UpdateLevelCrossing(TileIndex tile, bool sound)
01624 {
01625   assert(IsLevelCrossingTile(tile));
01626 
01627   /* train on crossing || train approaching crossing || reserved */
01628   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01629 
01630   if (new_state != IsCrossingBarred(tile)) {
01631     if (new_state && sound) {
01632       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01633     }
01634     SetCrossingBarred(tile, new_state);
01635     MarkTileDirtyByTile(tile);
01636   }
01637 }
01638 
01639 
01645 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01646 {
01647   if (!IsCrossingBarred(tile)) {
01648     BarCrossing(tile);
01649     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01650     MarkTileDirtyByTile(tile);
01651   }
01652 }
01653 
01654 
01660 static void AdvanceWagonsBeforeSwap(Train *v)
01661 {
01662   Train *base = v;
01663   Train *first = base; // first vehicle to move
01664   Train *last = v->Last(); // last vehicle to move
01665   uint length = CountVehiclesInChain(v);
01666 
01667   while (length > 2) {
01668     last = last->Previous();
01669     first = first->Next();
01670 
01671     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01672 
01673     /* do not update images now
01674      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01675     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01676 
01677     base = first; // == base->Next()
01678     length -= 2;
01679   }
01680 }
01681 
01682 
01688 static void AdvanceWagonsAfterSwap(Train *v)
01689 {
01690   /* first of all, fix the situation when the train was entering a depot */
01691   Train *dep = v; // last vehicle in front of just left depot
01692   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01693     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01694   }
01695 
01696   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01697 
01698   if (leave != NULL) {
01699     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01700     int d = TicksToLeaveDepot(dep);
01701 
01702     if (d <= 0) {
01703       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01704       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01705       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01706     }
01707   } else {
01708     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01709   }
01710 
01711   Train *base = v;
01712   Train *first = base; // first vehicle to move
01713   Train *last = v->Last(); // last vehicle to move
01714   uint length = CountVehiclesInChain(v);
01715 
01716   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01717    * they have already correct spacing, so we have to make sure they are moved how they should */
01718   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01719 
01720   while (length > 2) {
01721     /* we reached vehicle (originally) in front of a depot, stop now
01722      * (we would move wagons that are already moved with new wagon length). */
01723     if (base == dep) break;
01724 
01725     /* the last wagon was that one leaving a depot, so do not move it anymore */
01726     if (last == dep) nomove = true;
01727 
01728     last = last->Previous();
01729     first = first->Next();
01730 
01731     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01732 
01733     /* do not update images now */
01734     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01735 
01736     base = first; // == base->Next()
01737     length -= 2;
01738   }
01739 }
01740 
01741 
01742 void ReverseTrainDirection(Train *v)
01743 {
01744   if (IsRailDepotTile(v->tile)) {
01745     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01746   }
01747 
01748   /* Clear path reservation in front if train is not stuck. */
01749   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01750 
01751   /* Check if we were approaching a rail/road-crossing */
01752   TileIndex crossing = TrainApproachingCrossingTile(v);
01753 
01754   /* count number of vehicles */
01755   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01756 
01757   AdvanceWagonsBeforeSwap(v);
01758 
01759   /* swap start<>end, start+1<>end-1, ... */
01760   int l = 0;
01761   do {
01762     ReverseTrainSwapVeh(v, l++, r--);
01763   } while (l <= r);
01764 
01765   AdvanceWagonsAfterSwap(v);
01766 
01767   if (IsRailDepotTile(v->tile)) {
01768     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01769   }
01770 
01771   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01772 
01773   ClrBit(v->flags, VRF_REVERSING);
01774 
01775   /* recalculate cached data */
01776   v->ConsistChanged(true);
01777 
01778   /* update all images */
01779   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01780 
01781   /* update crossing we were approaching */
01782   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01783 
01784   /* maybe we are approaching crossing now, after reversal */
01785   crossing = TrainApproachingCrossingTile(v);
01786   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01787 
01788   /* If we are inside a depot after reversing, don't bother with path reserving. */
01789   if (v->track == TRACK_BIT_DEPOT) {
01790     /* Can't be stuck here as inside a depot is always a safe tile. */
01791     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01792     ClrBit(v->flags, VRF_TRAIN_STUCK);
01793     return;
01794   }
01795 
01796   /* TrainExitDir does not always produce the desired dir for depots and
01797    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01798   DiagDirection dir = TrainExitDir(v->direction, v->track);
01799   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01800 
01801   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01802     /* If we are currently on a tile with conventional signals, we can't treat the
01803      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01804     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01805       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01806       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01807 
01808     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01809     if (TryPathReserve(v, false, first_tile_okay)) {
01810       /* Do a look-ahead now in case our current tile was already a safe tile. */
01811       CheckNextTrainTile(v);
01812     } else if (v->current_order.GetType() != OT_LOADING) {
01813       /* Do not wait for a way out when we're still loading */
01814       MarkTrainAsStuck(v);
01815     }
01816   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01817     /* A train not inside a PBS block can't be stuck. */
01818     ClrBit(v->flags, VRF_TRAIN_STUCK);
01819     v->wait_counter = 0;
01820   }
01821 }
01822 
01832 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01833 {
01834   Train *v = Train::GetIfValid(p1);
01835   if (v == NULL) return CMD_ERROR;
01836 
01837   CommandCost ret = CheckOwnership(v->owner);
01838   if (ret.Failed()) return ret;
01839 
01840   if (p2 != 0) {
01841     /* turn a single unit around */
01842 
01843     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01844       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01845     }
01846     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01847 
01848     Train *front = v->First();
01849     /* make sure the vehicle is stopped in the depot */
01850     if (!front->IsStoppedInDepot()) {
01851       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01852     }
01853 
01854     if (flags & DC_EXEC) {
01855       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01856 
01857       front->ConsistChanged(false);
01858       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01859       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01860       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01861       SetWindowClassesDirty(WC_TRAINS_LIST);
01862     }
01863   } else {
01864     /* turn the whole train around */
01865     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01866 
01867     if (flags & DC_EXEC) {
01868       /* Properly leave the station if we are loading and won't be loading anymore */
01869       if (v->current_order.IsType(OT_LOADING)) {
01870         const Vehicle *last = v;
01871         while (last->Next() != NULL) last = last->Next();
01872 
01873         /* not a station || different station --> leave the station */
01874         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01875           v->LeaveStation();
01876         }
01877       }
01878 
01879       /* We cancel any 'skip signal at dangers' here */
01880       v->force_proceed = TFP_NONE;
01881       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01882 
01883       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01884         ToggleBit(v->flags, VRF_REVERSING);
01885       } else {
01886         v->cur_speed = 0;
01887         v->SetLastSpeed();
01888         HideFillingPercent(&v->fill_percent_te_id);
01889         ReverseTrainDirection(v);
01890       }
01891     }
01892   }
01893   return CommandCost();
01894 }
01895 
01905 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01906 {
01907   Train *t = Train::GetIfValid(p1);
01908   if (t == NULL) return CMD_ERROR;
01909 
01910   CommandCost ret = CheckOwnership(t->owner);
01911   if (ret.Failed()) return ret;
01912 
01913 
01914   if (flags & DC_EXEC) {
01915     /* If we are forced to proceed, cancel that order.
01916      * If we are marked stuck we would want to force the train
01917      * to proceed to the next signal. In the other cases we
01918      * would like to pass the signal at danger and run till the
01919      * next signal we encounter. */
01920     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01921     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01922   }
01923 
01924   return CommandCost();
01925 }
01926 
01931 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01932 {
01933   assert(!(v->vehstatus & VS_CRASHED));
01934 
01935   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01936 
01937   PBSTileInfo origin = FollowTrainReservation(v);
01938   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01939 
01940   switch (_settings_game.pf.pathfinder_for_trains) {
01941     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01942     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01943 
01944     default: NOT_REACHED();
01945   }
01946 }
01947 
01948 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01949 {
01950   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01951   if (tfdd.best_length == UINT_MAX) return false;
01952 
01953   if (location    != NULL) *location    = tfdd.tile;
01954   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01955   if (reverse     != NULL) *reverse     = tfdd.reverse;
01956 
01957   return true;
01958 }
01959 
01960 void Train::PlayLeaveStationSound() const
01961 {
01962   static const SoundFx sfx[] = {
01963     SND_04_TRAIN,
01964     SND_0A_TRAIN_HORN,
01965     SND_0A_TRAIN_HORN,
01966     SND_47_MAGLEV_2,
01967     SND_41_MAGLEV
01968   };
01969 
01970   if (PlayVehicleSound(this, VSE_START)) return;
01971 
01972   EngineID engtype = this->engine_type;
01973   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
01974 }
01975 
01977 static void CheckNextTrainTile(Train *v)
01978 {
01979   /* Don't do any look-ahead if path_backoff_interval is 255. */
01980   if (_settings_game.pf.path_backoff_interval == 255) return;
01981 
01982   /* Exit if we are inside a depot. */
01983   if (v->track == TRACK_BIT_DEPOT) return;
01984 
01985   switch (v->current_order.GetType()) {
01986     /* Exit if we reached our destination depot. */
01987     case OT_GOTO_DEPOT:
01988       if (v->tile == v->dest_tile) return;
01989       break;
01990 
01991     case OT_GOTO_WAYPOINT:
01992       /* If we reached our waypoint, make sure we see that. */
01993       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
01994       break;
01995 
01996     case OT_NOTHING:
01997     case OT_LEAVESTATION:
01998     case OT_LOADING:
01999       /* Exit if the current order doesn't have a destination, but the train has orders. */
02000       if (v->GetNumOrders() > 0) return;
02001       break;
02002 
02003     default:
02004       break;
02005   }
02006   /* Exit if we are on a station tile and are going to stop. */
02007   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02008 
02009   Trackdir td = v->GetVehicleTrackdir();
02010 
02011   /* On a tile with a red non-pbs signal, don't look ahead. */
02012   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02013       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02014       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02015 
02016   CFollowTrackRail ft(v);
02017   if (!ft.Follow(v->tile, td)) return;
02018 
02019   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02020     /* Next tile is not reserved. */
02021     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02022       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02023         /* If the next tile is a PBS signal, try to make a reservation. */
02024         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02025         if (_settings_game.pf.forbid_90_deg) {
02026           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02027         }
02028         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02029       }
02030     }
02031   }
02032 }
02033 
02034 static bool CheckTrainStayInDepot(Train *v)
02035 {
02036   /* bail out if not all wagons are in the same depot or not in a depot at all */
02037   for (const Train *u = v; u != NULL; u = u->Next()) {
02038     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02039   }
02040 
02041   /* if the train got no power, then keep it in the depot */
02042   if (v->gcache.cached_power == 0) {
02043     v->vehstatus |= VS_STOPPED;
02044     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02045     return true;
02046   }
02047 
02048   SigSegState seg_state;
02049 
02050   if (v->force_proceed == TFP_NONE) {
02051     /* force proceed was not pressed */
02052     if (++v->wait_counter < 37) {
02053       SetWindowClassesDirty(WC_TRAINS_LIST);
02054       return true;
02055     }
02056 
02057     v->wait_counter = 0;
02058 
02059     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02060     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02061       /* Full and no PBS signal in block or depot reserved, can't exit. */
02062       SetWindowClassesDirty(WC_TRAINS_LIST);
02063       return true;
02064     }
02065   } else {
02066     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02067   }
02068 
02069   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02070   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02071     /* We need to have a reservation for this to work. */
02072     if (HasDepotReservation(v->tile)) return true;
02073     SetDepotReservation(v->tile, true);
02074     VehicleEnterDepot(v);
02075     return true;
02076   }
02077 
02078   /* Only leave when we can reserve a path to our destination. */
02079   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02080     /* No path and no force proceed. */
02081     SetWindowClassesDirty(WC_TRAINS_LIST);
02082     MarkTrainAsStuck(v);
02083     return true;
02084   }
02085 
02086   SetDepotReservation(v->tile, true);
02087   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02088 
02089   VehicleServiceInDepot(v);
02090   SetWindowClassesDirty(WC_TRAINS_LIST);
02091   v->PlayLeaveStationSound();
02092 
02093   v->track = TRACK_BIT_X;
02094   if (v->direction & 2) v->track = TRACK_BIT_Y;
02095 
02096   v->vehstatus &= ~VS_HIDDEN;
02097   v->cur_speed = 0;
02098 
02099   v->UpdateDeltaXY(v->direction);
02100   v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
02101   VehicleMove(v, false);
02102   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02103   v->UpdateAcceleration();
02104   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02105 
02106   return false;
02107 }
02108 
02110 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02111 {
02112   DiagDirection dir = TrackdirToExitdir(track_dir);
02113 
02114   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02115     /* Are we just leaving a tunnel/bridge? */
02116     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02117       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02118 
02119       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02120         /* Free the reservation only if no other train is on the tiles. */
02121         SetTunnelBridgeReservation(tile, false);
02122         SetTunnelBridgeReservation(end, false);
02123 
02124         if (_settings_client.gui.show_track_reservation) {
02125           MarkTileDirtyByTile(tile);
02126           MarkTileDirtyByTile(end);
02127         }
02128       }
02129     }
02130   } else if (IsRailStationTile(tile)) {
02131     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02132     /* If the new tile is not a further tile of the same station, we
02133      * clear the reservation for the whole platform. */
02134     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02135       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02136     }
02137   } else {
02138     /* Any other tile */
02139     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02140   }
02141 }
02142 
02144 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02145 {
02146   assert(v->IsFrontEngine());
02147 
02148   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02149   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02150   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02151   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02152 
02153   /* Don't free reservation if it's not ours. */
02154   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02155 
02156   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02157   while (ft.Follow(tile, td)) {
02158     tile = ft.m_new_tile;
02159     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02160     td = RemoveFirstTrackdir(&bits);
02161     assert(bits == TRACKDIR_BIT_NONE);
02162 
02163     if (!IsValidTrackdir(td)) break;
02164 
02165     if (IsTileType(tile, MP_RAILWAY)) {
02166       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02167         /* Conventional signal along trackdir: remove reservation and stop. */
02168         UnreserveRailTrack(tile, TrackdirToTrack(td));
02169         break;
02170       }
02171       if (HasPbsSignalOnTrackdir(tile, td)) {
02172         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02173           /* Red PBS signal? Can't be our reservation, would be green then. */
02174           break;
02175         } else {
02176           /* Turn the signal back to red. */
02177           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02178           MarkTileDirtyByTile(tile);
02179         }
02180       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02181         break;
02182       }
02183     }
02184 
02185     /* Don't free first station/bridge/tunnel if we are on it. */
02186     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);
02187 
02188     free_tile = true;
02189   }
02190 }
02191 
02192 static const byte _initial_tile_subcoord[6][4][3] = {
02193 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02194 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02195 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02196 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02197 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02198 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02199 };
02200 
02213 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02214 {
02215   switch (_settings_game.pf.pathfinder_for_trains) {
02216     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02217     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02218 
02219     default: NOT_REACHED();
02220   }
02221 }
02222 
02228 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02229 {
02230   PBSTileInfo origin = FollowTrainReservation(v);
02231 
02232   CFollowTrackRail ft(v);
02233 
02234   TileIndex tile = origin.tile;
02235   Trackdir  cur_td = origin.trackdir;
02236   while (ft.Follow(tile, cur_td)) {
02237     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02238       /* Possible signal tile. */
02239       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02240     }
02241 
02242     if (_settings_game.pf.forbid_90_deg) {
02243       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02244       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02245     }
02246 
02247     /* Station, depot or waypoint are a possible target. */
02248     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02249     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02250       /* Choice found or possible target encountered.
02251        * On finding a possible target, we need to stop and let the pathfinder handle the
02252        * remaining path. This is because we don't know if this target is in one of our
02253        * orders, so we might cause pathfinding to fail later on if we find a choice.
02254        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02255        * a wrong path not leading to our next destination. */
02256       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02257 
02258       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02259        * actually starts its search at the first unreserved tile. */
02260       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02261 
02262       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02263       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02264       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02265       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02266     }
02267 
02268     tile = ft.m_new_tile;
02269     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02270 
02271     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02272       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02273       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02274       /* Safe position is all good, path valid and okay. */
02275       return PBSTileInfo(tile, cur_td, true);
02276     }
02277 
02278     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02279   }
02280 
02281   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02282     /* End of line, path valid and okay. */
02283     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02284   }
02285 
02286   /* Sorry, can't reserve path, back out. */
02287   tile = origin.tile;
02288   cur_td = origin.trackdir;
02289   TileIndex stopped = ft.m_old_tile;
02290   Trackdir  stopped_td = ft.m_old_td;
02291   while (tile != stopped || cur_td != stopped_td) {
02292     if (!ft.Follow(tile, cur_td)) break;
02293 
02294     if (_settings_game.pf.forbid_90_deg) {
02295       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02296       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02297     }
02298     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02299 
02300     tile = ft.m_new_tile;
02301     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02302 
02303     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02304   }
02305 
02306   /* Path invalid. */
02307   return PBSTileInfo();
02308 }
02309 
02320 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02321 {
02322   switch (_settings_game.pf.pathfinder_for_trains) {
02323     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02324     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02325 
02326     default: NOT_REACHED();
02327   }
02328 }
02329 
02331 class VehicleOrderSaver
02332 {
02333 private:
02334   Train          *v;
02335   Order          old_order;
02336   TileIndex      old_dest_tile;
02337   StationID      old_last_station_visited;
02338   VehicleOrderID index;
02339   bool           suppress_implicit_orders;
02340 
02341 public:
02342   VehicleOrderSaver(Train *_v) :
02343     v(_v),
02344     old_order(_v->current_order),
02345     old_dest_tile(_v->dest_tile),
02346     old_last_station_visited(_v->last_station_visited),
02347     index(_v->cur_real_order_index),
02348     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02349   {
02350   }
02351 
02352   ~VehicleOrderSaver()
02353   {
02354     this->v->current_order = this->old_order;
02355     this->v->dest_tile = this->old_dest_tile;
02356     this->v->last_station_visited = this->old_last_station_visited;
02357     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02358   }
02359 
02365   bool SwitchToNextOrder(bool skip_first)
02366   {
02367     if (this->v->GetNumOrders() == 0) return false;
02368 
02369     if (skip_first) ++this->index;
02370 
02371     int conditional_depth = 0;
02372 
02373     do {
02374       /* Wrap around. */
02375       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02376 
02377       Order *order = this->v->GetOrder(this->index);
02378       assert(order != NULL);
02379 
02380       switch (order->GetType()) {
02381         case OT_GOTO_DEPOT:
02382           /* Skip service in depot orders when the train doesn't need service. */
02383           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02384         case OT_GOTO_STATION:
02385         case OT_GOTO_WAYPOINT:
02386           this->v->current_order = *order;
02387           return UpdateOrderDest(this->v, order, 0, true);
02388         case OT_CONDITIONAL: {
02389           if (conditional_depth > this->v->GetNumOrders()) return false;
02390           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02391           if (next != INVALID_VEH_ORDER_ID) {
02392             conditional_depth++;
02393             this->index = next;
02394             /* Don't increment next, so no break here. */
02395             continue;
02396           }
02397           break;
02398         }
02399         default:
02400           break;
02401       }
02402       /* Don't increment inside the while because otherwise conditional
02403        * orders can lead to an infinite loop. */
02404       ++this->index;
02405     } while (this->index != this->v->cur_real_order_index);
02406 
02407     return false;
02408   }
02409 };
02410 
02411 /* choose a track */
02412 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02413 {
02414   Track best_track = INVALID_TRACK;
02415   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02416   bool changed_signal = false;
02417 
02418   assert((tracks & ~TRACK_BIT_MASK) == 0);
02419 
02420   if (got_reservation != NULL) *got_reservation = false;
02421 
02422   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02423   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02424   /* Do we have a suitable reserved track? */
02425   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02426 
02427   /* Quick return in case only one possible track is available */
02428   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02429     Track track = FindFirstTrack(tracks);
02430     /* We need to check for signals only here, as a junction tile can't have signals. */
02431     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02432       do_track_reservation = true;
02433       changed_signal = true;
02434       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02435     } else if (!do_track_reservation) {
02436       return track;
02437     }
02438     best_track = track;
02439   }
02440 
02441   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02442   DiagDirection dest_enterdir = enterdir;
02443   if (do_track_reservation) {
02444     /* Check if the train needs service here, so it has a chance to always find a depot.
02445      * Also check if the current order is a service order so we don't reserve a path to
02446      * the destination but instead to the next one if service isn't needed. */
02447     CheckIfTrainNeedsService(v);
02448     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02449 
02450     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02451     if (res_dest.tile == INVALID_TILE) {
02452       /* Reservation failed? */
02453       if (mark_stuck) MarkTrainAsStuck(v);
02454       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02455       return FindFirstTrack(tracks);
02456     }
02457   }
02458 
02459   /* Save the current train order. The destructor will restore the old order on function exit. */
02460   VehicleOrderSaver orders(v);
02461 
02462   /* If the current tile is the destination of the current order and
02463    * a reservation was requested, advance to the next order.
02464    * Don't advance on a depot order as depots are always safe end points
02465    * for a path and no look-ahead is necessary. This also avoids a
02466    * problem with depot orders not part of the order list when the
02467    * order list itself is empty. */
02468   if (v->current_order.IsType(OT_LEAVESTATION)) {
02469     orders.SwitchToNextOrder(false);
02470   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02471       v->current_order.IsType(OT_GOTO_STATION) ?
02472       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02473       v->tile == v->dest_tile))) {
02474     orders.SwitchToNextOrder(true);
02475   }
02476 
02477   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02478     /* Pathfinders are able to tell that route was only 'guessed'. */
02479     bool      path_found = true;
02480     TileIndex new_tile = res_dest.tile;
02481 
02482     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02483     if (new_tile == tile) best_track = next_track;
02484     v->HandlePathfindingResult(path_found);
02485   }
02486 
02487   /* No track reservation requested -> finished. */
02488   if (!do_track_reservation) return best_track;
02489 
02490   /* A path was found, but could not be reserved. */
02491   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02492     if (mark_stuck) MarkTrainAsStuck(v);
02493     FreeTrainTrackReservation(v);
02494     return best_track;
02495   }
02496 
02497   /* No possible reservation target found, we are probably lost. */
02498   if (res_dest.tile == INVALID_TILE) {
02499     /* Try to find any safe destination. */
02500     PBSTileInfo origin = FollowTrainReservation(v);
02501     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02502       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02503       best_track = FindFirstTrack(res);
02504       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02505       if (got_reservation != NULL) *got_reservation = true;
02506       if (changed_signal) MarkTileDirtyByTile(tile);
02507     } else {
02508       FreeTrainTrackReservation(v);
02509       if (mark_stuck) MarkTrainAsStuck(v);
02510     }
02511     return best_track;
02512   }
02513 
02514   if (got_reservation != NULL) *got_reservation = true;
02515 
02516   /* Reservation target found and free, check if it is safe. */
02517   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02518     /* Extend reservation until we have found a safe position. */
02519     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02520     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02521     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02522     if (_settings_game.pf.forbid_90_deg) {
02523       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02524     }
02525 
02526     /* Get next order with destination. */
02527     if (orders.SwitchToNextOrder(true)) {
02528       PBSTileInfo cur_dest;
02529       bool path_found;
02530       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02531       if (cur_dest.tile != INVALID_TILE) {
02532         res_dest = cur_dest;
02533         if (res_dest.okay) continue;
02534         /* Path found, but could not be reserved. */
02535         FreeTrainTrackReservation(v);
02536         if (mark_stuck) MarkTrainAsStuck(v);
02537         if (got_reservation != NULL) *got_reservation = false;
02538         changed_signal = false;
02539         break;
02540       }
02541     }
02542     /* No order or no safe position found, try any position. */
02543     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02544       FreeTrainTrackReservation(v);
02545       if (mark_stuck) MarkTrainAsStuck(v);
02546       if (got_reservation != NULL) *got_reservation = false;
02547       changed_signal = false;
02548     }
02549     break;
02550   }
02551 
02552   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02553 
02554   if (changed_signal) MarkTileDirtyByTile(tile);
02555 
02556   return best_track;
02557 }
02558 
02567 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02568 {
02569   assert(v->IsFrontEngine());
02570 
02571   /* We have to handle depots specially as the track follower won't look
02572    * at the depot tile itself but starts from the next tile. If we are still
02573    * inside the depot, a depot reservation can never be ours. */
02574   if (v->track == TRACK_BIT_DEPOT) {
02575     if (HasDepotReservation(v->tile)) {
02576       if (mark_as_stuck) MarkTrainAsStuck(v);
02577       return false;
02578     } else {
02579       /* Depot not reserved, but the next tile might be. */
02580       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02581       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02582     }
02583   }
02584 
02585   Vehicle *other_train = NULL;
02586   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02587   /* The path we are driving on is already blocked by some other train.
02588    * This can only happen in certain situations when mixing path and
02589    * block signals or when changing tracks and/or signals.
02590    * Exit here as doing any further reservations will probably just
02591    * make matters worse. */
02592   if (other_train != NULL && other_train->index != v->index) {
02593     if (mark_as_stuck) MarkTrainAsStuck(v);
02594     return false;
02595   }
02596   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02597   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02598     /* Can't be stuck then. */
02599     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02600     ClrBit(v->flags, VRF_TRAIN_STUCK);
02601     return true;
02602   }
02603 
02604   /* If we are in a depot, tentatively reserve the depot. */
02605   if (v->track == TRACK_BIT_DEPOT) {
02606     SetDepotReservation(v->tile, true);
02607     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02608   }
02609 
02610   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02611   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02612   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02613 
02614   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02615 
02616   bool res_made = false;
02617   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02618 
02619   if (!res_made) {
02620     /* Free the depot reservation as well. */
02621     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02622     return false;
02623   }
02624 
02625   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02626     v->wait_counter = 0;
02627     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02628   }
02629   ClrBit(v->flags, VRF_TRAIN_STUCK);
02630   return true;
02631 }
02632 
02633 
02634 static bool CheckReverseTrain(const Train *v)
02635 {
02636   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02637       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02638       !(v->direction & 1)) {
02639     return false;
02640   }
02641 
02642   assert(v->track != TRACK_BIT_NONE);
02643 
02644   switch (_settings_game.pf.pathfinder_for_trains) {
02645     case VPF_NPF: return NPFTrainCheckReverse(v);
02646     case VPF_YAPF: return YapfTrainCheckReverse(v);
02647 
02648     default: NOT_REACHED();
02649   }
02650 }
02651 
02652 TileIndex Train::GetOrderStationLocation(StationID station)
02653 {
02654   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02655 
02656   const Station *st = Station::Get(station);
02657   if (!(st->facilities & FACIL_TRAIN)) {
02658     /* The destination station has no trainstation tiles. */
02659     this->IncrementRealOrderIndex();
02660     return 0;
02661   }
02662 
02663   return st->xy;
02664 }
02665 
02666 void Train::MarkDirty()
02667 {
02668   Train *v = this;
02669   do {
02670     v->UpdateViewport(false, false);
02671   } while ((v = v->Next()) != NULL);
02672 
02673   /* need to update acceleration and cached values since the goods on the train changed. */
02674   this->CargoChanged();
02675   this->UpdateAcceleration();
02676 }
02677 
02685 int Train::UpdateSpeed()
02686 {
02687   switch (_settings_game.vehicle.train_acceleration_model) {
02688     default: NOT_REACHED();
02689     case AM_ORIGINAL:
02690       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, this->gcache.cached_max_track_speed);
02691 
02692     case AM_REALISTIC:
02693       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02694   }
02695 }
02696 
02702 static void TrainEnterStation(Train *v, StationID station)
02703 {
02704   v->last_station_visited = station;
02705 
02706   /* check if a train ever visited this station before */
02707   Station *st = Station::Get(station);
02708   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02709     st->had_vehicle_of_type |= HVOT_TRAIN;
02710     SetDParam(0, st->index);
02711     AddVehicleNewsItem(
02712       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02713       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
02714       v->index,
02715       st->index
02716     );
02717     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02718     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02719   }
02720 
02721   v->force_proceed = TFP_NONE;
02722   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02723 
02724   v->BeginLoading();
02725 
02726   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02727 }
02728 
02729 /* Check if the vehicle is compatible with the specified tile */
02730 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02731 {
02732   return IsTileOwner(tile, v->owner) &&
02733       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02734 }
02735 
02736 struct RailtypeSlowdownParams {
02737   byte small_turn, large_turn;
02738   byte z_up; // fraction to remove when moving up
02739   byte z_down; // fraction to remove when moving down
02740 };
02741 
02742 static const RailtypeSlowdownParams _railtype_slowdown[] = {
02743   /* normal accel */
02744   {256 / 4, 256 / 2, 256 / 4, 2}, 
02745   {256 / 4, 256 / 2, 256 / 4, 2}, 
02746   {256 / 4, 256 / 2, 256 / 4, 2}, 
02747   {0,       256 / 2, 256 / 4, 2}, 
02748 };
02749 
02751 static inline void AffectSpeedByZChange(Train *v, int old_z)
02752 {
02753   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02754 
02755   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
02756 
02757   if (old_z < v->z_pos) {
02758     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
02759   } else {
02760     uint16 spd = v->cur_speed + rsp->z_down;
02761     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02762   }
02763 }
02764 
02765 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02766 {
02767   if (IsTileType(tile, MP_RAILWAY) &&
02768       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02769     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02770     Trackdir trackdir = FindFirstTrackdir(tracks);
02771     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02772       /* A PBS block with a non-PBS signal facing us? */
02773       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02774     }
02775   }
02776   return false;
02777 }
02778 
02782 void Train::ReserveTrackUnderConsist() const
02783 {
02784   for (const Train *u = this; u != NULL; u = u->Next()) {
02785     switch (u->track) {
02786       case TRACK_BIT_WORMHOLE:
02787         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02788         break;
02789       case TRACK_BIT_DEPOT:
02790         break;
02791       default:
02792         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02793         break;
02794     }
02795   }
02796 }
02797 
02798 uint Train::Crash(bool flooded)
02799 {
02800   uint pass = 0;
02801   if (this->IsFrontEngine()) {
02802     pass += 2; // driver
02803 
02804     /* Remove the reserved path in front of the train if it is not stuck.
02805      * Also clear all reserved tracks the train is currently on. */
02806     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02807     for (const Train *v = this; v != NULL; v = v->Next()) {
02808       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02809       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02810         /* ClearPathReservation will not free the wormhole exit
02811          * if the train has just entered the wormhole. */
02812         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02813       }
02814     }
02815 
02816     /* we may need to update crossing we were approaching,
02817      * but must be updated after the train has been marked crashed */
02818     TileIndex crossing = TrainApproachingCrossingTile(this);
02819     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02820 
02821     /* Remove the loading indicators (if any) */
02822     HideFillingPercent(&this->fill_percent_te_id);
02823   }
02824 
02825   pass += this->GroundVehicleBase::Crash(flooded);
02826 
02827   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02828   return pass;
02829 }
02830 
02837 static uint TrainCrashed(Train *v)
02838 {
02839   uint num = 0;
02840 
02841   /* do not crash train twice */
02842   if (!(v->vehstatus & VS_CRASHED)) {
02843     num = v->Crash();
02844     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02845     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02846   }
02847 
02848   /* Try to re-reserve track under already crashed train too.
02849    * Crash() clears the reservation! */
02850   v->ReserveTrackUnderConsist();
02851 
02852   return num;
02853 }
02854 
02855 struct TrainCollideChecker {
02856   Train *v; 
02857   uint num; 
02858 };
02859 
02860 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02861 {
02862   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02863 
02864   /* not a train or in depot */
02865   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02866 
02867   /* do not crash into trains of another company. */
02868   if (v->owner != tcc->v->owner) return NULL;
02869 
02870   /* get first vehicle now to make most usual checks faster */
02871   Train *coll = Train::From(v)->First();
02872 
02873   /* can't collide with own wagons */
02874   if (coll == tcc->v) return NULL;
02875 
02876   int x_diff = v->x_pos - tcc->v->x_pos;
02877   int y_diff = v->y_pos - tcc->v->y_pos;
02878 
02879   /* Do fast calculation to check whether trains are not in close vicinity
02880    * and quickly reject trains distant enough for any collision.
02881    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02882    * Differences are then ORed and then we check for any higher bits */
02883   uint hash = (y_diff + 7) | (x_diff + 7);
02884   if (hash & ~15) return NULL;
02885 
02886   /* Slower check using multiplication */
02887   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02888   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02889 
02890   /* Happens when there is a train under bridge next to bridge head */
02891   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02892 
02893   /* crash both trains */
02894   tcc->num += TrainCrashed(tcc->v);
02895   tcc->num += TrainCrashed(coll);
02896 
02897   return NULL; // continue searching
02898 }
02899 
02906 static bool CheckTrainCollision(Train *v)
02907 {
02908   /* can't collide in depot */
02909   if (v->track == TRACK_BIT_DEPOT) return false;
02910 
02911   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
02912 
02913   TrainCollideChecker tcc;
02914   tcc.v = v;
02915   tcc.num = 0;
02916 
02917   /* find colliding vehicles */
02918   if (v->track == TRACK_BIT_WORMHOLE) {
02919     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
02920     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
02921   } else {
02922     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
02923   }
02924 
02925   /* any dead -> no crash */
02926   if (tcc.num == 0) return false;
02927 
02928   SetDParam(0, tcc.num);
02929   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH,
02930     NS_ACCIDENT,
02931     v->index
02932   );
02933 
02934   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
02935   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
02936   return true;
02937 }
02938 
02939 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
02940 {
02941   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
02942 
02943   Train *t = Train::From(v);
02944   DiagDirection exitdir = *(DiagDirection *)data;
02945 
02946   /* not front engine of a train, inside wormhole or depot, crashed */
02947   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
02948 
02949   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
02950 
02951   return t;
02952 }
02953 
02961 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
02962 {
02963   Train *first = v->First();
02964   Train *prev;
02965   bool direction_changed = false; // has direction of any part changed?
02966 
02967   /* For every vehicle after and including the given vehicle */
02968   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
02969     DiagDirection enterdir = DIAGDIR_BEGIN;
02970     bool update_signals_crossing = false; // will we update signals or crossing state?
02971 
02972     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
02973     if (v->track != TRACK_BIT_WORMHOLE) {
02974       /* Not inside tunnel */
02975       if (gp.old_tile == gp.new_tile) {
02976         /* Staying in the old tile */
02977         if (v->track == TRACK_BIT_DEPOT) {
02978           /* Inside depot */
02979           gp.x = v->x_pos;
02980           gp.y = v->y_pos;
02981         } else {
02982           /* Not inside depot */
02983 
02984           /* Reverse when we are at the end of the track already, do not move to the new position */
02985           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
02986 
02987           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
02988           if (HasBit(r, VETS_CANNOT_ENTER)) {
02989             goto invalid_rail;
02990           }
02991           if (HasBit(r, VETS_ENTERED_STATION)) {
02992             /* The new position is the end of the platform */
02993             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
02994           }
02995         }
02996       } else {
02997         /* A new tile is about to be entered. */
02998 
02999         /* Determine what direction we're entering the new tile from */
03000         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03001         assert(IsValidDiagDirection(enterdir));
03002 
03003         /* Get the status of the tracks in the new tile and mask
03004          * away the bits that aren't reachable. */
03005         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03006         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03007 
03008         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03009         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03010 
03011         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03012         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03013           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03014            * can be switched on halfway a turn */
03015           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03016         }
03017 
03018         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03019 
03020         /* Check if the new tile constrains tracks that are compatible
03021          * with the current train, if not, bail out. */
03022         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03023 
03024         TrackBits chosen_track;
03025         if (prev == NULL) {
03026           /* Currently the locomotive is active. Determine which one of the
03027            * available tracks to choose */
03028           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03029           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03030 
03031           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03032             /* For each signal we find decrease the counter by one.
03033              * We start at two, so the first signal we pass decreases
03034              * this to one, then if we reach the next signal it is
03035              * decreased to zero and we won't pass that new signal. */
03036             Trackdir dir = FindFirstTrackdir(trackdirbits);
03037             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03038                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03039               /* However, we do not want to be stopped by PBS signals
03040                * entered via the back. */
03041               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03042               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03043             }
03044           }
03045 
03046           /* Check if it's a red signal and that force proceed is not clicked. */
03047           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03048             /* In front of a red signal */
03049             Trackdir i = FindFirstTrackdir(trackdirbits);
03050 
03051             /* Don't handle stuck trains here. */
03052             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03053 
03054             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03055               v->cur_speed = 0;
03056               v->subspeed = 0;
03057               v->progress = 255 - 100;
03058               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03059             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03060               v->cur_speed = 0;
03061               v->subspeed = 0;
03062               v->progress = 255 - 10;
03063               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03064                 DiagDirection exitdir = TrackdirToExitdir(i);
03065                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03066 
03067                 exitdir = ReverseDiagDir(exitdir);
03068 
03069                 /* check if a train is waiting on the other side */
03070                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03071               }
03072             }
03073 
03074             /* If we would reverse but are currently in a PBS block and
03075              * reversing of stuck trains is disabled, don't reverse.
03076              * This does not apply if the reason for reversing is a one-way
03077              * signal blocking us, because a train would then be stuck forever. */
03078             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03079                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03080               v->wait_counter = 0;
03081               return false;
03082             }
03083             goto reverse_train_direction;
03084           } else {
03085             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03086           }
03087         } else {
03088           /* The wagon is active, simply follow the prev vehicle. */
03089           if (prev->tile == gp.new_tile) {
03090             /* Choose the same track as prev */
03091             if (prev->track == TRACK_BIT_WORMHOLE) {
03092               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03093                * However, just choose the track into the wormhole. */
03094               assert(IsTunnel(prev->tile));
03095               chosen_track = bits;
03096             } else {
03097               chosen_track = prev->track;
03098             }
03099           } else {
03100             /* Choose the track that leads to the tile where prev is.
03101              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03102              * I.e. when the tile between them has only space for a single vehicle like
03103              *  1) horizontal/vertical track tiles and
03104              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03105              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03106              */
03107             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03108               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03109               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03110               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03111               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03112             };
03113             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03114             assert(IsValidDiagDirection(exitdir));
03115             chosen_track = _connecting_track[enterdir][exitdir];
03116           }
03117           chosen_track &= bits;
03118         }
03119 
03120         /* Make sure chosen track is a valid track */
03121         assert(
03122             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03123             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03124             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03125 
03126         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03127         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03128         gp.x = (gp.x & ~0xF) | b[0];
03129         gp.y = (gp.y & ~0xF) | b[1];
03130         Direction chosen_dir = (Direction)b[2];
03131 
03132         /* Call the landscape function and tell it that the vehicle entered the tile */
03133         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03134         if (HasBit(r, VETS_CANNOT_ENTER)) {
03135           goto invalid_rail;
03136         }
03137 
03138         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03139           Track track = FindFirstTrack(chosen_track);
03140           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03141           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03142             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03143             MarkTileDirtyByTile(gp.new_tile);
03144           }
03145 
03146           /* Clear any track reservation when the last vehicle leaves the tile */
03147           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03148 
03149           v->tile = gp.new_tile;
03150 
03151           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03152             v->First()->RailtypeChanged();
03153           }
03154 
03155           v->track = chosen_track;
03156           assert(v->track);
03157         }
03158 
03159         /* We need to update signal status, but after the vehicle position hash
03160          * has been updated by UpdateInclination() */
03161         update_signals_crossing = true;
03162 
03163         if (chosen_dir != v->direction) {
03164           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03165             const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
03166             DirDiff diff = DirDifference(v->direction, chosen_dir);
03167             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03168           }
03169           direction_changed = true;
03170           v->direction = chosen_dir;
03171         }
03172 
03173         if (v->IsFrontEngine()) {
03174           v->wait_counter = 0;
03175 
03176           /* If we are approaching a crossing that is reserved, play the sound now. */
03177           TileIndex crossing = TrainApproachingCrossingTile(v);
03178           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03179 
03180           /* Always try to extend the reservation when entering a tile. */
03181           CheckNextTrainTile(v);
03182         }
03183 
03184         if (HasBit(r, VETS_ENTERED_STATION)) {
03185           /* The new position is the location where we want to stop */
03186           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03187         }
03188       }
03189     } else {
03190       /* In a tunnel or on a bridge
03191        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03192        * - for bridges, only the middle part - without the bridge heads */
03193       if (!(v->vehstatus & VS_HIDDEN)) {
03194         Train *first = v->First();
03195         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03196       }
03197 
03198       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03199         /* Perform look-ahead on tunnel exit. */
03200         if (v->IsFrontEngine()) {
03201           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03202           CheckNextTrainTile(v);
03203         }
03204         /* Prevent v->UpdateInclination() being called with wrong parameters.
03205          * This could happen if the train was reversed inside the tunnel/bridge. */
03206         if (gp.old_tile == gp.new_tile) {
03207           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03208         }
03209       } else {
03210         v->x_pos = gp.x;
03211         v->y_pos = gp.y;
03212         VehicleMove(v, !(v->vehstatus & VS_HIDDEN));
03213         continue;
03214       }
03215     }
03216 
03217     /* update image of train, as well as delta XY */
03218     v->UpdateDeltaXY(v->direction);
03219 
03220     v->x_pos = gp.x;
03221     v->y_pos = gp.y;
03222 
03223     /* update the Z position of the vehicle */
03224     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03225 
03226     if (prev == NULL) {
03227       /* This is the first vehicle in the train */
03228       AffectSpeedByZChange(v, old_z);
03229     }
03230 
03231     if (update_signals_crossing) {
03232       if (v->IsFrontEngine()) {
03233         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03234           /* We are entering a block with PBS signals right now, but
03235            * not through a PBS signal. This means we don't have a
03236            * reservation right now. As a conventional signal will only
03237            * ever be green if no other train is in the block, getting
03238            * a path should always be possible. If the player built
03239            * such a strange network that it is not possible, the train
03240            * will be marked as stuck and the player has to deal with
03241            * the problem. */
03242           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03243               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03244               !TryPathReserve(v)) {
03245             MarkTrainAsStuck(v);
03246           }
03247         }
03248       }
03249 
03250       /* Signals can only change when the first
03251        * (above) or the last vehicle moves. */
03252       if (v->Next() == NULL) {
03253         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03254         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03255       }
03256     }
03257 
03258     /* Do not check on every tick to save some computing time. */
03259     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03260   }
03261 
03262   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03263 
03264   return true;
03265 
03266 invalid_rail:
03267   /* We've reached end of line?? */
03268   if (prev != NULL) error("Disconnecting train");
03269 
03270 reverse_train_direction:
03271   if (reverse) {
03272     v->wait_counter = 0;
03273     v->cur_speed = 0;
03274     v->subspeed = 0;
03275     ReverseTrainDirection(v);
03276   }
03277 
03278   return false;
03279 }
03280 
03287 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03288 {
03289   TrackBits *trackbits = (TrackBits *)data;
03290 
03291   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03292     TrackBits train_tbits = Train::From(v)->track;
03293     if (train_tbits == TRACK_BIT_WORMHOLE) {
03294       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03295       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03296     } else if (train_tbits != TRACK_BIT_DEPOT) {
03297       *trackbits |= train_tbits;
03298     }
03299   }
03300 
03301   return NULL;
03302 }
03303 
03311 static void DeleteLastWagon(Train *v)
03312 {
03313   Train *first = v->First();
03314 
03315   /* Go to the last wagon and delete the link pointing there
03316    * *u is then the one-before-last wagon, and *v the last
03317    * one which will physically be removed */
03318   Train *u = v;
03319   for (; v->Next() != NULL; v = v->Next()) u = v;
03320   u->SetNext(NULL);
03321 
03322   if (first != v) {
03323     /* Recalculate cached train properties */
03324     first->ConsistChanged(false);
03325     /* Update the depot window if the first vehicle is in depot -
03326      * if v == first, then it is updated in PreDestructor() */
03327     if (first->track == TRACK_BIT_DEPOT) {
03328       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03329     }
03330   }
03331 
03332   /* 'v' shouldn't be accessed after it has been deleted */
03333   TrackBits trackbits = v->track;
03334   TileIndex tile = v->tile;
03335   Owner owner = v->owner;
03336 
03337   delete v;
03338   v = NULL; // make sure nobody will try to read 'v' anymore
03339 
03340   if (trackbits == TRACK_BIT_WORMHOLE) {
03341     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03342     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03343   }
03344 
03345   Track track = TrackBitsToTrack(trackbits);
03346   if (HasReservedTracks(tile, trackbits)) {
03347     UnreserveRailTrack(tile, track);
03348 
03349     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03350     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03351     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03352 
03353     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03354     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03355     Track t;
03356     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03357   }
03358 
03359   /* check if the wagon was on a road/rail-crossing */
03360   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03361 
03362   /* Update signals */
03363   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03364     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03365   } else {
03366     SetSignalsOnBothDir(tile, track, owner);
03367   }
03368 }
03369 
03374 static void ChangeTrainDirRandomly(Train *v)
03375 {
03376   static const DirDiff delta[] = {
03377     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03378   };
03379 
03380   do {
03381     /* We don't need to twist around vehicles if they're not visible */
03382     if (!(v->vehstatus & VS_HIDDEN)) {
03383       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03384       v->UpdateDeltaXY(v->direction);
03385       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03386       /* Refrain from updating the z position of the vehicle when on
03387        * a bridge, because UpdateInclination() will put the vehicle under
03388        * the bridge in that case */
03389       if (v->track != TRACK_BIT_WORMHOLE) v->UpdateInclination(false, false);
03390     }
03391   } while ((v = v->Next()) != NULL);
03392 }
03393 
03399 static bool HandleCrashedTrain(Train *v)
03400 {
03401   int state = ++v->crash_anim_pos;
03402 
03403   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03404     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03405   }
03406 
03407   uint32 r;
03408   if (state <= 200 && Chance16R(1, 7, r)) {
03409     int index = (r * 10 >> 16);
03410 
03411     Vehicle *u = v;
03412     do {
03413       if (--index < 0) {
03414         r = Random();
03415 
03416         CreateEffectVehicleRel(u,
03417           GB(r,  8, 3) + 2,
03418           GB(r, 16, 3) + 2,
03419           GB(r,  0, 3) + 5,
03420           EV_EXPLOSION_SMALL);
03421         break;
03422       }
03423     } while ((u = u->Next()) != NULL);
03424   }
03425 
03426   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03427 
03428   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03429     bool ret = v->Next() != NULL;
03430     DeleteLastWagon(v);
03431     return ret;
03432   }
03433 
03434   return true;
03435 }
03436 
03438 static const uint16 _breakdown_speeds[16] = {
03439   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03440 };
03441 
03442 
03451 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03452 {
03453   /* Calc position within the current tile */
03454   uint x = v->x_pos & 0xF;
03455   uint y = v->y_pos & 0xF;
03456 
03457   /* for diagonal directions, 'x' will be 0..15 -
03458    * for other directions, it will be 1, 3, 5, ..., 15 */
03459   switch (v->direction) {
03460     case DIR_N : x = ~x + ~y + 25; break;
03461     case DIR_NW: x = y;            // FALL THROUGH
03462     case DIR_NE: x = ~x + 16;      break;
03463     case DIR_E : x = ~x + y + 9;   break;
03464     case DIR_SE: x = y;            break;
03465     case DIR_S : x = x + y - 7;    break;
03466     case DIR_W : x = ~y + x + 9;   break;
03467     default: break;
03468   }
03469 
03470   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03471    * does not cross the tile boundary when we do reverse, but as the vehicle's
03472    * location is based on their center, use half a vehicle's length as offset.
03473    * Multiply the half-length by two for straight directions to compensate that
03474    * we only get odd x offsets there. */
03475   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03476     /* we are too near the tile end, reverse now */
03477     v->cur_speed = 0;
03478     if (reverse) ReverseTrainDirection(v);
03479     return false;
03480   }
03481 
03482   /* slow down */
03483   v->vehstatus |= VS_TRAIN_SLOWING;
03484   uint16 break_speed = _breakdown_speeds[x & 0xF];
03485   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03486 
03487   return true;
03488 }
03489 
03490 
03496 static bool TrainCanLeaveTile(const Train *v)
03497 {
03498   /* Exit if inside a tunnel/bridge or a depot */
03499   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03500 
03501   TileIndex tile = v->tile;
03502 
03503   /* entering a tunnel/bridge? */
03504   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03505     DiagDirection dir = GetTunnelBridgeDirection(tile);
03506     if (DiagDirToDir(dir) == v->direction) return false;
03507   }
03508 
03509   /* entering a depot? */
03510   if (IsRailDepotTile(tile)) {
03511     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03512     if (DiagDirToDir(dir) == v->direction) return false;
03513   }
03514 
03515   return true;
03516 }
03517 
03518 
03526 static TileIndex TrainApproachingCrossingTile(const Train *v)
03527 {
03528   assert(v->IsFrontEngine());
03529   assert(!(v->vehstatus & VS_CRASHED));
03530 
03531   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03532 
03533   DiagDirection dir = TrainExitDir(v->direction, v->track);
03534   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03535 
03536   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03537   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03538       !CheckCompatibleRail(v, tile)) {
03539     return INVALID_TILE;
03540   }
03541 
03542   return tile;
03543 }
03544 
03545 
03553 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03554 {
03555   /* First, handle broken down train */
03556 
03557   int t = v->breakdown_ctr;
03558   if (t > 1) {
03559     v->vehstatus |= VS_TRAIN_SLOWING;
03560 
03561     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03562     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03563   } else {
03564     v->vehstatus &= ~VS_TRAIN_SLOWING;
03565   }
03566 
03567   if (!TrainCanLeaveTile(v)) return true;
03568 
03569   /* Determine the non-diagonal direction in which we will exit this tile */
03570   DiagDirection dir = TrainExitDir(v->direction, v->track);
03571   /* Calculate next tile */
03572   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03573 
03574   /* Determine the track status on the next tile */
03575   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03576   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03577 
03578   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03579   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03580 
03581   /* We are sure the train is not entering a depot, it is detected above */
03582 
03583   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03584   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03585   if (_settings_game.pf.forbid_90_deg) {
03586     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03587   }
03588 
03589   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03590   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03591     return TrainApproachingLineEnd(v, false, reverse);
03592   }
03593 
03594   /* approaching red signal */
03595   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03596 
03597   /* approaching a rail/road crossing? then make it red */
03598   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03599 
03600   return true;
03601 }
03602 
03603 
03604 static bool TrainLocoHandler(Train *v, bool mode)
03605 {
03606   /* train has crashed? */
03607   if (v->vehstatus & VS_CRASHED) {
03608     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03609   }
03610 
03611   if (v->force_proceed != TFP_NONE) {
03612     ClrBit(v->flags, VRF_TRAIN_STUCK);
03613     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03614   }
03615 
03616   /* train is broken down? */
03617   if (v->HandleBreakdown()) return true;
03618 
03619   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03620     ReverseTrainDirection(v);
03621   }
03622 
03623   /* exit if train is stopped */
03624   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03625 
03626   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03627   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03628     v->wait_counter = 0;
03629     v->cur_speed = 0;
03630     v->subspeed = 0;
03631     ClrBit(v->flags, VRF_LEAVING_STATION);
03632     ReverseTrainDirection(v);
03633     return true;
03634   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03635     /* Try to reserve a path when leaving the station as we
03636      * might not be marked as wanting a reservation, e.g.
03637      * when an overlength train gets turned around in a station. */
03638     DiagDirection dir = TrainExitDir(v->direction, v->track);
03639     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03640 
03641     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03642       TryPathReserve(v, true, true);
03643     }
03644     ClrBit(v->flags, VRF_LEAVING_STATION);
03645   }
03646 
03647   v->HandleLoading(mode);
03648 
03649   if (v->current_order.IsType(OT_LOADING)) return true;
03650 
03651   if (CheckTrainStayInDepot(v)) return true;
03652 
03653   if (!mode) v->ShowVisualEffect();
03654 
03655   /* We had no order but have an order now, do look ahead. */
03656   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03657     CheckNextTrainTile(v);
03658   }
03659 
03660   /* Handle stuck trains. */
03661   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03662     ++v->wait_counter;
03663 
03664     /* Should we try reversing this tick if still stuck? */
03665     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03666 
03667     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03668     if (!TryPathReserve(v)) {
03669       /* Still stuck. */
03670       if (turn_around) ReverseTrainDirection(v);
03671 
03672       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03673         /* Show message to player. */
03674         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03675           SetDParam(0, v->index);
03676           AddVehicleNewsItem(
03677             STR_NEWS_TRAIN_IS_STUCK,
03678             NS_ADVICE,
03679             v->index
03680           );
03681         }
03682         v->wait_counter = 0;
03683       }
03684       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03685       if (v->force_proceed == TFP_NONE) return true;
03686       ClrBit(v->flags, VRF_TRAIN_STUCK);
03687       v->wait_counter = 0;
03688       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03689     }
03690   }
03691 
03692   if (v->current_order.IsType(OT_LEAVESTATION)) {
03693     v->current_order.Free();
03694     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03695     return true;
03696   }
03697 
03698   int j = v->UpdateSpeed();
03699 
03700   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03701   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03702     /* If we manually stopped, we're not force-proceeding anymore. */
03703     v->force_proceed = TFP_NONE;
03704     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03705   }
03706 
03707   int adv_spd = v->GetAdvanceDistance();
03708   if (j < adv_spd) {
03709     /* if the vehicle has speed 0, update the last_speed field. */
03710     if (v->cur_speed == 0) v->SetLastSpeed();
03711   } else {
03712     TrainCheckIfLineEnds(v);
03713     /* Loop until the train has finished moving. */
03714     for (;;) {
03715       j -= adv_spd;
03716       TrainController(v, NULL);
03717       /* Don't continue to move if the train crashed. */
03718       if (CheckTrainCollision(v)) break;
03719       /* Determine distance to next map position */
03720       adv_spd = v->GetAdvanceDistance();
03721 
03722       /* No more moving this tick */
03723       if (j < adv_spd || v->cur_speed == 0) break;
03724 
03725       OrderType order_type = v->current_order.GetType();
03726       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03727       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03728             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03729             IsTileType(v->tile, MP_STATION) &&
03730             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03731         ProcessOrders(v);
03732       }
03733     }
03734     v->SetLastSpeed();
03735   }
03736 
03737   for (Train *u = v; u != NULL; u = u->Next()) {
03738     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03739 
03740     u->UpdateViewport(false, false);
03741   }
03742 
03743   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03744 
03745   return true;
03746 }
03747 
03748 
03749 
03750 Money Train::GetRunningCost() const
03751 {
03752   Money cost = 0;
03753   const Train *v = this;
03754 
03755   do {
03756     const Engine *e = v->GetEngine();
03757     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03758 
03759     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03760     if (cost_factor == 0) continue;
03761 
03762     /* Halve running cost for multiheaded parts */
03763     if (v->IsMultiheaded()) cost_factor /= 2;
03764 
03765     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03766   } while ((v = v->GetNextVehicle()) != NULL);
03767 
03768   return cost;
03769 }
03770 
03771 
03772 bool Train::Tick()
03773 {
03774   this->tick_counter++;
03775 
03776   if (this->IsFrontEngine()) {
03777     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03778 
03779     this->current_order_time++;
03780 
03781     if (!TrainLocoHandler(this, false)) return false;
03782 
03783     return TrainLocoHandler(this, true);
03784   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03785     /* Delete flooded standalone wagon chain */
03786     if (++this->crash_anim_pos >= 4400) {
03787       delete this;
03788       return false;
03789     }
03790   }
03791 
03792   return true;
03793 }
03794 
03795 static void CheckIfTrainNeedsService(Train *v)
03796 {
03797   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03798   if (v->IsInDepot()) {
03799     VehicleServiceInDepot(v);
03800     return;
03801   }
03802 
03803   uint max_penalty;
03804   switch (_settings_game.pf.pathfinder_for_trains) {
03805     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03806     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03807     default: NOT_REACHED();
03808   }
03809 
03810   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03811   /* Only go to the depot if it is not too far out of our way. */
03812   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03813     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03814       /* If we were already heading for a depot but it has
03815        * suddenly moved farther away, we continue our normal
03816        * schedule? */
03817       v->current_order.MakeDummy();
03818       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03819     }
03820     return;
03821   }
03822 
03823   DepotID depot = GetDepotIndex(tfdd.tile);
03824 
03825   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03826       v->current_order.GetDestination() != depot &&
03827       !Chance16(3, 16)) {
03828     return;
03829   }
03830 
03831   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03832   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03833   v->dest_tile = tfdd.tile;
03834   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03835 }
03836 
03837 void Train::OnNewDay()
03838 {
03839   AgeVehicle(this);
03840 
03841   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03842 
03843   if (this->IsFrontEngine()) {
03844     CheckVehicleBreakdown(this);
03845 
03846     CheckIfTrainNeedsService(this);
03847 
03848     CheckOrders(this);
03849 
03850     /* update destination */
03851     if (this->current_order.IsType(OT_GOTO_STATION)) {
03852       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03853       if (tile != INVALID_TILE) this->dest_tile = tile;
03854     }
03855 
03856     if (this->running_ticks != 0) {
03857       /* running costs */
03858       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03859 
03860       this->profit_this_year -= cost.GetCost();
03861       this->running_ticks = 0;
03862 
03863       SubtractMoneyFromCompanyFract(this->owner, cost);
03864 
03865       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03866       SetWindowClassesDirty(WC_TRAINS_LIST);
03867     }
03868   }
03869 }
03870 
03871 Trackdir Train::GetVehicleTrackdir() const
03872 {
03873   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03874 
03875   if (this->track == TRACK_BIT_DEPOT) {
03876     /* We'll assume the train is facing outwards */
03877     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03878   }
03879 
03880   if (this->track == TRACK_BIT_WORMHOLE) {
03881     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03882     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03883   }
03884 
03885   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03886 }