train_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "error.h"
00014 #include "articulated_vehicles.h"
00015 #include "command_func.h"
00016 #include "pathfinder/npf/npf_func.h"
00017 #include "pathfinder/yapf/yapf.hpp"
00018 #include "news_func.h"
00019 #include "company_func.h"
00020 #include "newgrf_sound.h"
00021 #include "newgrf_text.h"
00022 #include "strings_func.h"
00023 #include "viewport_func.h"
00024 #include "vehicle_func.h"
00025 #include "sound_func.h"
00026 #include "ai/ai.hpp"
00027 #include "game/game.hpp"
00028 #include "newgrf_station.h"
00029 #include "effectvehicle_func.h"
00030 #include "network/network.h"
00031 #include "spritecache.h"
00032 #include "core/random_func.hpp"
00033 #include "company_base.h"
00034 #include "newgrf.h"
00035 #include "order_backup.h"
00036 #include "zoom_func.h"
00037 
00038 #include "table/strings.h"
00039 #include "table/train_cmd.h"
00040 
00041 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00042 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00043 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00044 static TileIndex TrainApproachingCrossingTile(const Train *v);
00045 static void CheckIfTrainNeedsService(Train *v);
00046 static void CheckNextTrainTile(Train *v);
00047 
00048 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00049 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00050 
00051 
00059 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00060 {
00061   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00062 
00063   DiagDirection diagdir = DirToDiagDir(direction);
00064 
00065   /* Determine the diagonal direction in which we will exit this tile */
00066   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00067     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00068   }
00069 
00070   return diagdir;
00071 }
00072 
00073 
00079 byte FreightWagonMult(CargoID cargo)
00080 {
00081   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00082   return _settings_game.vehicle.freight_trains;
00083 }
00084 
00086 void CheckTrainsLengths()
00087 {
00088   const Train *v;
00089   bool first = true;
00090 
00091   FOR_ALL_TRAINS(v) {
00092     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00093       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00094         if (u->track != TRACK_BIT_DEPOT) {
00095           if ((w->track != TRACK_BIT_DEPOT &&
00096               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00097               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00098             SetDParam(0, v->index);
00099             SetDParam(1, v->owner);
00100             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00101 
00102             if (!_networking && first) {
00103               first = false;
00104               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00105             }
00106             /* Break so we warn only once for each train. */
00107             break;
00108           }
00109         }
00110       }
00111     }
00112   }
00113 }
00114 
00121 void Train::ConsistChanged(bool same_length)
00122 {
00123   uint16 max_speed = UINT16_MAX;
00124 
00125   assert(this->IsFrontEngine() || this->IsFreeWagon());
00126 
00127   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00128   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00129   this->gcache.cached_total_length = 0;
00130   this->compatible_railtypes = RAILTYPES_NONE;
00131 
00132   bool train_can_tilt = true;
00133 
00134   for (Train *u = this; u != NULL; u = u->Next()) {
00135     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00136 
00137     /* Check the this->first cache. */
00138     assert(u->First() == this);
00139 
00140     /* update the 'first engine' */
00141     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00142     u->railtype = rvi_u->railtype;
00143 
00144     if (u->IsEngine()) first_engine = u->engine_type;
00145 
00146     /* Set user defined data to its default value */
00147     u->tcache.user_def_data = rvi_u->user_def_data;
00148     this->InvalidateNewGRFCache();
00149     u->InvalidateNewGRFCache();
00150   }
00151 
00152   for (Train *u = this; u != NULL; u = u->Next()) {
00153     /* Update user defined data (must be done before other properties) */
00154     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00155     this->InvalidateNewGRFCache();
00156     u->InvalidateNewGRFCache();
00157   }
00158 
00159   for (Train *u = this; u != NULL; u = u->Next()) {
00160     const Engine *e_u = u->GetEngine();
00161     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00162 
00163     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00164 
00165     /* Cache wagon override sprite group. NULL is returned if there is none */
00166     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00167 
00168     /* Reset colour map */
00169     u->colourmap = PAL_NONE;
00170 
00171     /* Update powered-wagon-status and visual effect */
00172     u->UpdateVisualEffect(true);
00173 
00174     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00175         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00176       /* wagon is powered */
00177       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00178     } else {
00179       ClrBit(u->flags, VRF_POWEREDWAGON);
00180     }
00181 
00182     if (!u->IsArticulatedPart()) {
00183       /* Do not count powered wagons for the compatible railtypes, as wagons always
00184          have railtype normal */
00185       if (rvi_u->power > 0) {
00186         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00187       }
00188 
00189       /* Some electric engines can be allowed to run on normal rail. It happens to all
00190        * existing electric engines when elrails are disabled and then re-enabled */
00191       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00192         u->railtype = RAILTYPE_RAIL;
00193         u->compatible_railtypes |= RAILTYPES_RAIL;
00194       }
00195 
00196       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00197       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00198         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00199         if (speed != 0) max_speed = min(speed, max_speed);
00200       }
00201     }
00202 
00203     uint16 new_cap = e_u->DetermineCapacity(u);
00204     u->refit_cap = min(new_cap, u->refit_cap);
00205     u->cargo_cap = new_cap;
00206     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00207 
00208     /* check the vehicle length (callback) */
00209     uint16 veh_len = CALLBACK_FAILED;
00210     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00211       /* Use callback 36 */
00212       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00213 
00214       if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00215         ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00216       }
00217     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00218       /* Use callback 11 */
00219       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00220     }
00221     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00222     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00223 
00224     /* verify length hasn't changed */
00225     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00226 
00227     /* update vehicle length? */
00228     if (!same_length) u->gcache.cached_veh_length = veh_len;
00229 
00230     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00231     this->InvalidateNewGRFCache();
00232     u->InvalidateNewGRFCache();
00233   }
00234 
00235   /* store consist weight/max speed in cache */
00236   this->vcache.cached_max_speed = max_speed;
00237   this->tcache.cached_tilt = train_can_tilt;
00238   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00239 
00240   /* 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) */
00241   this->CargoChanged();
00242 
00243   if (this->IsFrontEngine()) {
00244     this->UpdateAcceleration();
00245     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00246     InvalidateWindowData(WC_VEHICLE_REFIT, this->index, VIWD_CONSIST_CHANGED);
00247     InvalidateWindowData(WC_VEHICLE_ORDERS, this->index, VIWD_CONSIST_CHANGED);
00248   }
00249 }
00250 
00261 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00262 {
00263   const Station *st = Station::Get(station_id);
00264   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00265   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00266 
00267   /* Default to the middle of the station for stations stops that are not in
00268    * the order list like intermediate stations when non-stop is disabled */
00269   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00270   if (v->gcache.cached_total_length >= *station_length) {
00271     /* The train is longer than the station, make it stop at the far end of the platform */
00272     osl = OSL_PLATFORM_FAR_END;
00273   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00274     osl = v->current_order.GetStopLocation();
00275   }
00276 
00277   /* The stop location of the FRONT! of the train */
00278   int stop;
00279   switch (osl) {
00280     default: NOT_REACHED();
00281 
00282     case OSL_PLATFORM_NEAR_END:
00283       stop = v->gcache.cached_total_length;
00284       break;
00285 
00286     case OSL_PLATFORM_MIDDLE:
00287       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00288       break;
00289 
00290     case OSL_PLATFORM_FAR_END:
00291       stop = *station_length;
00292       break;
00293   }
00294 
00295   /* Subtract half the front vehicle length of the train so we get the real
00296    * stop location of the train. */
00297   return stop - (v->gcache.cached_veh_length + 1) / 2;
00298 }
00299 
00300 
00305 int Train::GetCurveSpeedLimit() const
00306 {
00307   assert(this->First() == this);
00308 
00309   static const int absolute_max_speed = UINT16_MAX;
00310   int max_speed = absolute_max_speed;
00311 
00312   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00313 
00314   int curvecount[2] = {0, 0};
00315 
00316   /* first find the curve speed limit */
00317   int numcurve = 0;
00318   int sum = 0;
00319   int pos = 0;
00320   int lastpos = -1;
00321   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00322     Direction this_dir = u->direction;
00323     Direction next_dir = u->Next()->direction;
00324 
00325     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00326     if (dirdiff == DIRDIFF_SAME) continue;
00327 
00328     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00329     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00330     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00331       if (lastpos != -1) {
00332         numcurve++;
00333         sum += pos - lastpos;
00334         if (pos - lastpos == 1 && max_speed > 88) {
00335           max_speed = 88;
00336         }
00337       }
00338       lastpos = pos;
00339     }
00340 
00341     /* if we have a 90 degree turn, fix the speed limit to 60 */
00342     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00343       max_speed = 61;
00344     }
00345   }
00346 
00347   if (numcurve > 0 && max_speed > 88) {
00348     if (curvecount[0] == 1 && curvecount[1] == 1) {
00349       max_speed = absolute_max_speed;
00350     } else {
00351       sum /= numcurve;
00352       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00353     }
00354   }
00355 
00356   if (max_speed != absolute_max_speed) {
00357     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00358     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00359     max_speed += (max_speed / 2) * rti->curve_speed;
00360 
00361     if (this->tcache.cached_tilt) {
00362       /* Apply max_speed bonus of 20% for a tilting train */
00363       max_speed += max_speed / 5;
00364     }
00365   }
00366 
00367   return max_speed;
00368 }
00369 
00374 int Train::GetCurrentMaxSpeed() const
00375 {
00376   int max_speed = _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL ?
00377       this->gcache.cached_max_track_speed :
00378       this->tcache.cached_max_curve_speed;
00379 
00380   if (_settings_game.vehicle.train_acceleration_model == AM_REALISTIC && IsRailStationTile(this->tile)) {
00381     StationID sid = GetStationIndex(this->tile);
00382     if (this->current_order.ShouldStopAtStation(this, sid)) {
00383       int station_ahead;
00384       int station_length;
00385       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00386 
00387       /* The distance to go is whatever is still ahead of the train minus the
00388        * distance from the train's stop location to the end of the platform */
00389       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00390 
00391       if (distance_to_go > 0) {
00392         int st_max_speed = 120;
00393 
00394         int delta_v = this->cur_speed / (distance_to_go + 1);
00395         if (max_speed > (this->cur_speed - delta_v)) {
00396           st_max_speed = this->cur_speed - (delta_v / 10);
00397         }
00398 
00399         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00400         max_speed = min(max_speed, st_max_speed);
00401       }
00402     }
00403   }
00404 
00405   for (const Train *u = this; u != NULL; u = u->Next()) {
00406     if (_settings_game.vehicle.train_acceleration_model == AM_REALISTIC && u->track == TRACK_BIT_DEPOT) {
00407       max_speed = min(max_speed, 61);
00408       break;
00409     }
00410 
00411     /* Vehicle is on the middle part of a bridge. */
00412     if (u->track == TRACK_BIT_WORMHOLE && !(u->vehstatus & VS_HIDDEN)) {
00413       max_speed = min(max_speed, GetBridgeSpec(GetBridgeType(u->tile))->speed);
00414     }
00415   }
00416 
00417   max_speed = min(max_speed, this->current_order.max_speed);
00418   return min(max_speed, this->gcache.cached_max_track_speed);
00419 }
00420 
00422 void Train::UpdateAcceleration()
00423 {
00424   assert(this->IsFrontEngine());
00425 
00426   uint power = this->gcache.cached_power;
00427   uint weight = this->gcache.cached_weight;
00428   assert(weight != 0);
00429   this->acceleration = Clamp(power / weight * 4, 1, 255);
00430 }
00431 
00437 int Train::GetDisplayImageWidth(Point *offset) const
00438 {
00439   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00440   int vehicle_pitch = 0;
00441 
00442   const Engine *e = this->GetEngine();
00443   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00444     reference_width = e->GetGRF()->traininfo_vehicle_width;
00445     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00446   }
00447 
00448   if (offset != NULL) {
00449     offset->x = reference_width / 2;
00450     offset->y = vehicle_pitch;
00451   }
00452   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00453 }
00454 
00455 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00456 {
00457   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00458 }
00459 
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.StoredCount() >= 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 
00542 void GetTrainSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type)
00543 {
00544   int y = 0;
00545 
00546   SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00547   const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00548 
00549   width  = UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI);
00550   height = UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI);
00551   xoffs  = UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI);
00552   yoffs  = UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI);
00553 
00554   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00555     sprite = GetRailIcon(engine, true, y, image_type);
00556     real_sprite = GetSprite(sprite, ST_NORMAL);
00557 
00558     /* Calculate values relative to an imaginary center between the two sprites. */
00559     width = TRAININFO_DEFAULT_VEHICLE_WIDTH + UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) + UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI) - xoffs;
00560     height = max<uint>(height, UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI));
00561     xoffs  = xoffs - TRAININFO_DEFAULT_VEHICLE_WIDTH / 2;
00562     yoffs  = min(yoffs, UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI));
00563   }
00564 }
00565 
00574 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00575 {
00576   const RailVehicleInfo *rvi = &e->u.rail;
00577 
00578   /* Check that the wagon can drive on the track in question */
00579   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00580 
00581   if (flags & DC_EXEC) {
00582     Train *v = new Train();
00583     *ret = v;
00584     v->spritenum = rvi->image_index;
00585 
00586     v->engine_type = e->index;
00587     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00588 
00589     DiagDirection dir = GetRailDepotDirection(tile);
00590 
00591     v->direction = DiagDirToDir(dir);
00592     v->tile = tile;
00593 
00594     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00595     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00596 
00597     v->x_pos = x;
00598     v->y_pos = y;
00599     v->z_pos = GetSlopePixelZ(x, y);
00600     v->owner = _current_company;
00601     v->track = TRACK_BIT_DEPOT;
00602     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00603 
00604     v->SetWagon();
00605 
00606     v->SetFreeWagon();
00607     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00608 
00609     v->cargo_type = e->GetDefaultCargoType();
00610     v->cargo_cap = rvi->capacity;
00611     v->refit_cap = 0;
00612 
00613     v->railtype = rvi->railtype;
00614 
00615     v->build_year = _cur_year;
00616     v->cur_image = SPR_IMG_QUERY;
00617     v->random_bits = VehicleRandomBits();
00618 
00619     v->group_id = DEFAULT_GROUP;
00620 
00621     AddArticulatedParts(v);
00622 
00623     _new_vehicle_id = v->index;
00624 
00625     VehicleUpdatePosition(v);
00626     v->First()->ConsistChanged(false);
00627     UpdateTrainGroupID(v->First());
00628 
00629     CheckConsistencyOfArticulatedVehicle(v);
00630 
00631     /* Try to connect the vehicle to one of free chains of wagons. */
00632     Train *w;
00633     FOR_ALL_TRAINS(w) {
00634       if (w->tile == tile &&              
00635           w->IsFreeWagon() &&             
00636           w->engine_type == e->index &&   
00637           w->First() != v &&              
00638           !(w->vehstatus & VS_CRASHED)) { 
00639         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00640         break;
00641       }
00642     }
00643   }
00644 
00645   return CommandCost();
00646 }
00647 
00649 static void NormalizeTrainVehInDepot(const Train *u)
00650 {
00651   const Train *v;
00652   FOR_ALL_TRAINS(v) {
00653     if (v->IsFreeWagon() && v->tile == u->tile &&
00654         v->track == TRACK_BIT_DEPOT) {
00655       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00656           CMD_MOVE_RAIL_VEHICLE).Failed())
00657         break;
00658     }
00659   }
00660 }
00661 
00662 static void AddRearEngineToMultiheadedTrain(Train *v)
00663 {
00664   Train *u = new Train();
00665   v->value >>= 1;
00666   u->value = v->value;
00667   u->direction = v->direction;
00668   u->owner = v->owner;
00669   u->tile = v->tile;
00670   u->x_pos = v->x_pos;
00671   u->y_pos = v->y_pos;
00672   u->z_pos = v->z_pos;
00673   u->track = TRACK_BIT_DEPOT;
00674   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00675   u->spritenum = v->spritenum + 1;
00676   u->cargo_type = v->cargo_type;
00677   u->cargo_subtype = v->cargo_subtype;
00678   u->cargo_cap = v->cargo_cap;
00679   u->refit_cap = v->refit_cap;
00680   u->railtype = v->railtype;
00681   u->engine_type = v->engine_type;
00682   u->build_year = v->build_year;
00683   u->cur_image = SPR_IMG_QUERY;
00684   u->random_bits = VehicleRandomBits();
00685   v->SetMultiheaded();
00686   u->SetMultiheaded();
00687   v->SetNext(u);
00688   VehicleUpdatePosition(u);
00689 
00690   /* Now we need to link the front and rear engines together */
00691   v->other_multiheaded_part = u;
00692   u->other_multiheaded_part = v;
00693 }
00694 
00704 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00705 {
00706   const RailVehicleInfo *rvi = &e->u.rail;
00707 
00708   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00709 
00710   /* Check if depot and new engine uses the same kind of tracks *
00711    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00712   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00713 
00714   if (flags & DC_EXEC) {
00715     DiagDirection dir = GetRailDepotDirection(tile);
00716     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00717     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00718 
00719     Train *v = new Train();
00720     *ret = v;
00721     v->direction = DiagDirToDir(dir);
00722     v->tile = tile;
00723     v->owner = _current_company;
00724     v->x_pos = x;
00725     v->y_pos = y;
00726     v->z_pos = GetSlopePixelZ(x, y);
00727     v->track = TRACK_BIT_DEPOT;
00728     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00729     v->spritenum = rvi->image_index;
00730     v->cargo_type = e->GetDefaultCargoType();
00731     v->cargo_cap = rvi->capacity;
00732     v->refit_cap = 0;
00733     v->last_station_visited = INVALID_STATION;
00734     v->last_loading_station = INVALID_STATION;
00735 
00736     v->engine_type = e->index;
00737     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00738 
00739     v->reliability = e->reliability;
00740     v->reliability_spd_dec = e->reliability_spd_dec;
00741     v->max_age = e->GetLifeLengthInDays();
00742 
00743     v->railtype = rvi->railtype;
00744     _new_vehicle_id = v->index;
00745 
00746     v->SetServiceInterval(Company::Get(_current_company)->settings.vehicle.servint_trains);
00747     v->date_of_last_service = _date;
00748     v->build_year = _cur_year;
00749     v->cur_image = SPR_IMG_QUERY;
00750     v->random_bits = VehicleRandomBits();
00751 
00752     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00753     v->SetServiceIntervalIsPercent(Company::Get(_current_company)->settings.vehicle.servint_ispercent);
00754 
00755     v->group_id = DEFAULT_GROUP;
00756 
00757     v->SetFrontEngine();
00758     v->SetEngine();
00759 
00760     VehicleUpdatePosition(v);
00761 
00762     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00763       AddRearEngineToMultiheadedTrain(v);
00764     } else {
00765       AddArticulatedParts(v);
00766     }
00767 
00768     v->ConsistChanged(false);
00769     UpdateTrainGroupID(v);
00770 
00771     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00772       NormalizeTrainVehInDepot(v);
00773     }
00774 
00775     CheckConsistencyOfArticulatedVehicle(v);
00776   }
00777 
00778   return CommandCost();
00779 }
00780 
00781 static Train *FindGoodVehiclePos(const Train *src)
00782 {
00783   EngineID eng = src->engine_type;
00784   TileIndex tile = src->tile;
00785 
00786   Train *dst;
00787   FOR_ALL_TRAINS(dst) {
00788     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00789       /* check so all vehicles in the line have the same engine. */
00790       Train *t = dst;
00791       while (t->engine_type == eng) {
00792         t = t->Next();
00793         if (t == NULL) return dst;
00794       }
00795     }
00796   }
00797 
00798   return NULL;
00799 }
00800 
00802 typedef SmallVector<Train *, 16> TrainList;
00803 
00809 static void MakeTrainBackup(TrainList &list, Train *t)
00810 {
00811   for (; t != NULL; t = t->Next()) *list.Append() = t;
00812 }
00813 
00818 static void RestoreTrainBackup(TrainList &list)
00819 {
00820   /* No train, nothing to do. */
00821   if (list.Length() == 0) return;
00822 
00823   Train *prev = NULL;
00824   /* Iterate over the list and rebuild it. */
00825   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00826     Train *t = *iter;
00827     if (prev != NULL) {
00828       prev->SetNext(t);
00829     } else if (t->Previous() != NULL) {
00830       /* Make sure the head of the train is always the first in the chain. */
00831       t->Previous()->SetNext(NULL);
00832     }
00833     prev = t;
00834   }
00835 }
00836 
00842 static void RemoveFromConsist(Train *part, bool chain = false)
00843 {
00844   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00845 
00846   /* Unlink at the front, but make it point to the next
00847    * vehicle after the to be remove part. */
00848   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00849 
00850   /* Unlink at the back */
00851   tail->SetNext(NULL);
00852 }
00853 
00859 static void InsertInConsist(Train *dst, Train *chain)
00860 {
00861   /* We do not want to add something in the middle of an articulated part. */
00862   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00863 
00864   chain->Last()->SetNext(dst->Next());
00865   dst->SetNext(chain);
00866 }
00867 
00873 static void NormaliseDualHeads(Train *t)
00874 {
00875   for (; t != NULL; t = t->GetNextVehicle()) {
00876     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00877 
00878     /* Make sure that there are no free cars before next engine */
00879     Train *u;
00880     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00881 
00882     if (u == t->other_multiheaded_part) continue;
00883 
00884     /* Remove the part from the 'wrong' train */
00885     RemoveFromConsist(t->other_multiheaded_part);
00886     /* And add it to the 'right' train */
00887     InsertInConsist(u, t->other_multiheaded_part);
00888   }
00889 }
00890 
00895 static void NormaliseSubtypes(Train *chain)
00896 {
00897   /* Nothing to do */
00898   if (chain == NULL) return;
00899 
00900   /* We must be the first in the chain. */
00901   assert(chain->Previous() == NULL);
00902 
00903   /* Set the appropriate bits for the first in the chain. */
00904   if (chain->IsWagon()) {
00905     chain->SetFreeWagon();
00906   } else {
00907     assert(chain->IsEngine());
00908     chain->SetFrontEngine();
00909   }
00910 
00911   /* Now clear the bits for the rest of the chain */
00912   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00913     t->ClearFreeWagon();
00914     t->ClearFrontEngine();
00915   }
00916 }
00917 
00927 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00928 {
00929   /* Just add 'new' engines and subtract the original ones.
00930    * If that's less than or equal to 0 we can be sure we did
00931    * not add any engines (read: trains) along the way. */
00932   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00933       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00934       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00935       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00936     return CommandCost();
00937   }
00938 
00939   /* Get a free unit number and check whether it's within the bounds.
00940    * There will always be a maximum of one new train. */
00941   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00942 
00943   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00944 }
00945 
00951 static CommandCost CheckTrainAttachment(Train *t)
00952 {
00953   /* No multi-part train, no need to check. */
00954   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00955 
00956   /* The maximum length for a train. For each part we decrease this by one
00957    * and if the result is negative the train is simply too long. */
00958   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00959 
00960   Train *head = t;
00961   Train *prev = t;
00962 
00963   /* Break the prev -> t link so it always holds within the loop. */
00964   t = t->Next();
00965   prev->SetNext(NULL);
00966 
00967   /* Make sure the cache is cleared. */
00968   head->InvalidateNewGRFCache();
00969 
00970   while (t != NULL) {
00971     allowed_len -= t->gcache.cached_veh_length;
00972 
00973     Train *next = t->Next();
00974 
00975     /* Unlink the to-be-added piece; it is already unlinked from the previous
00976      * part due to the fact that the prev -> t link is broken. */
00977     t->SetNext(NULL);
00978 
00979     /* Don't check callback for articulated or rear dual headed parts */
00980     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00981       /* Back up and clear the first_engine data to avoid using wagon override group */
00982       EngineID first_engine = t->gcache.first_engine;
00983       t->gcache.first_engine = INVALID_ENGINE;
00984 
00985       /* We don't want the cache to interfere. head's cache is cleared before
00986        * the loop and after each callback does not need to be cleared here. */
00987       t->InvalidateNewGRFCache();
00988 
00989       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00990 
00991       /* Restore original first_engine data */
00992       t->gcache.first_engine = first_engine;
00993 
00994       /* We do not want to remember any cached variables from the test run */
00995       t->InvalidateNewGRFCache();
00996       head->InvalidateNewGRFCache();
00997 
00998       if (callback != CALLBACK_FAILED) {
00999         /* A failing callback means everything is okay */
01000         StringID error = STR_NULL;
01001 
01002         if (head->GetGRF()->grf_version < 8) {
01003           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01004           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01005           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
01006         } else {
01007           if (callback < 0x400) {
01008             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01009           } else {
01010             switch (callback) {
01011               case 0x400: // allow if railtypes match (always the case for OpenTTD)
01012               case 0x401: // allow
01013                 break;
01014 
01015               default:    // unknown reason -> disallow
01016               case 0x402: // disallow attaching
01017                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01018                 break;
01019             }
01020           }
01021         }
01022 
01023         if (error != STR_NULL) return_cmd_error(error);
01024       }
01025     }
01026 
01027     /* And link it to the new part. */
01028     prev->SetNext(t);
01029     prev = t;
01030     t = next;
01031   }
01032 
01033   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01034   return CommandCost();
01035 }
01036 
01047 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01048 {
01049   /* Check whether we may actually construct the trains. */
01050   CommandCost ret = CheckTrainAttachment(src);
01051   if (ret.Failed()) return ret;
01052   ret = CheckTrainAttachment(dst);
01053   if (ret.Failed()) return ret;
01054 
01055   /* Check whether we need to build a new train. */
01056   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01057 }
01058 
01067 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01068 {
01069   /* First determine the front of the two resulting trains */
01070   if (*src_head == *dst_head) {
01071     /* If we aren't moving part(s) to a new train, we are just moving the
01072      * front back and there is not destination head. */
01073     *dst_head = NULL;
01074   } else if (*dst_head == NULL) {
01075     /* If we are moving to a new train the head of the move train would become
01076      * the head of the new vehicle. */
01077     *dst_head = src;
01078   }
01079 
01080   if (src == *src_head) {
01081     /* If we are moving the front of a train then we are, in effect, creating
01082      * a new head for the train. Point to that. Unless we are moving the whole
01083      * train in which case there is not 'source' train anymore.
01084      * In case we are a multiheaded part we want the complete thing to come
01085      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01086      * that is followed by a rear multihead we do not want to include that. */
01087     *src_head = move_chain ? NULL :
01088         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01089   }
01090 
01091   /* Now it's just simply removing the part that we are going to move from the
01092    * source train and *if* the destination is a not a new train add the chain
01093    * at the destination location. */
01094   RemoveFromConsist(src, move_chain);
01095   if (*dst_head != src) InsertInConsist(dst, src);
01096 
01097   /* Now normalise the dual heads, that is move the dual heads around in such
01098    * a way that the head and rear of a dual head are in the same train */
01099   NormaliseDualHeads(*src_head);
01100   NormaliseDualHeads(*dst_head);
01101 }
01102 
01108 static void NormaliseTrainHead(Train *head)
01109 {
01110   /* Not much to do! */
01111   if (head == NULL) return;
01112 
01113   /* Tell the 'world' the train changed. */
01114   head->ConsistChanged(false);
01115   UpdateTrainGroupID(head);
01116 
01117   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01118   if (!head->IsFrontEngine()) return;
01119 
01120   /* Update the refit button and window */
01121   InvalidateWindowData(WC_VEHICLE_REFIT, head->index, VIWD_CONSIST_CHANGED);
01122   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01123 
01124   /* If we don't have a unit number yet, set one. */
01125   if (head->unitnumber != 0) return;
01126   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01127 }
01128 
01141 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01142 {
01143   VehicleID s = GB(p1, 0, 20);
01144   VehicleID d = GB(p2, 0, 20);
01145   bool move_chain = HasBit(p1, 20);
01146 
01147   Train *src = Train::GetIfValid(s);
01148   if (src == NULL) return CMD_ERROR;
01149 
01150   CommandCost ret = CheckOwnership(src->owner);
01151   if (ret.Failed()) return ret;
01152 
01153   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01154   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01155 
01156   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01157   Train *dst;
01158   if (d == INVALID_VEHICLE) {
01159     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01160   } else {
01161     dst = Train::GetIfValid(d);
01162     if (dst == NULL) return CMD_ERROR;
01163 
01164     CommandCost ret = CheckOwnership(dst->owner);
01165     if (ret.Failed()) return ret;
01166 
01167     /* Do not allow appending to crashed vehicles, too */
01168     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01169   }
01170 
01171   /* if an articulated part is being handled, deal with its parent vehicle */
01172   src = src->GetFirstEnginePart();
01173   if (dst != NULL) {
01174     dst = dst->GetFirstEnginePart();
01175   }
01176 
01177   /* don't move the same vehicle.. */
01178   if (src == dst) return CommandCost();
01179 
01180   /* locate the head of the two chains */
01181   Train *src_head = src->First();
01182   Train *dst_head;
01183   if (dst != NULL) {
01184     dst_head = dst->First();
01185     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01186     /* Now deal with articulated part of destination wagon */
01187     dst = dst->GetLastEnginePart();
01188   } else {
01189     dst_head = NULL;
01190   }
01191 
01192   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01193 
01194   /* When moving all wagons, we can't have the same src_head and dst_head */
01195   if (move_chain && src_head == dst_head) return CommandCost();
01196 
01197   /* When moving a multiheaded part to be place after itself, bail out. */
01198   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01199 
01200   /* Check if all vehicles in the source train are stopped inside a depot. */
01201   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01202 
01203   /* Check if all vehicles in the destination train are stopped inside a depot. */
01204   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01205 
01206   /* First make a backup of the order of the trains. That way we can do
01207    * whatever we want with the order and later on easily revert. */
01208   TrainList original_src;
01209   TrainList original_dst;
01210 
01211   MakeTrainBackup(original_src, src_head);
01212   MakeTrainBackup(original_dst, dst_head);
01213 
01214   /* Also make backup of the original heads as ArrangeTrains can change them.
01215    * For the destination head we do not care if it is the same as the source
01216    * head because in that case it's just a copy. */
01217   Train *original_src_head = src_head;
01218   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01219 
01220   /* We want this information from before the rearrangement, but execute this after the validation. */
01221   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01222   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01223 
01224   /* (Re)arrange the trains in the wanted arrangement. */
01225   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01226 
01227   if ((flags & DC_AUTOREPLACE) == 0) {
01228     /* If the autoreplace flag is set we do not need to test for the validity
01229      * because we are going to revert the train to its original state. As we
01230      * assume the original state was correct autoreplace can skip this. */
01231     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01232     if (ret.Failed()) {
01233       /* Restore the train we had. */
01234       RestoreTrainBackup(original_src);
01235       RestoreTrainBackup(original_dst);
01236       return ret;
01237     }
01238   }
01239 
01240   /* do it? */
01241   if (flags & DC_EXEC) {
01242     /* Remove old heads from the statistics */
01243     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01244     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01245 
01246     /* First normalise the sub types of the chains. */
01247     NormaliseSubtypes(src_head);
01248     NormaliseSubtypes(dst_head);
01249 
01250     /* There are 14 different cases:
01251      *  1) front engine gets moved to a new train, it stays a front engine.
01252      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01253      *     b) the 'next' part is an engine that becomes a front engine.
01254      *     c) there is no 'next' part, nothing else happens
01255      *  2) front engine gets moved to another train, it is not a front engine anymore
01256      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01257      *     b) the 'next' part is an engine that becomes a front engine.
01258      *     c) there is no 'next' part, nothing else happens
01259      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01260      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01261      *     b) the 'next' part is an engine that becomes a front engine.
01262      *  4) free wagon gets moved
01263      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01264      *     b) the 'next' part is an engine that becomes a front engine.
01265      *     c) there is no 'next' part, nothing else happens
01266      *  5) non front engine gets moved and becomes a new train, nothing else happens
01267      *  6) non front engine gets moved within a train / to another train, nothing hapens
01268      *  7) wagon gets moved, nothing happens
01269      */
01270     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01271       /* Cases #2 and #3: the front engine gets trashed. */
01272       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01273       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01274       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01275       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01276       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01277       SetWindowDirty(WC_COMPANY, _current_company);
01278 
01279       /* Delete orders, group stuff and the unit number as we're not the
01280        * front of any vehicle anymore. */
01281       DeleteVehicleOrders(src);
01282       RemoveVehicleFromGroup(src);
01283       src->unitnumber = 0;
01284     }
01285 
01286     /* We weren't a front engine but are becoming one. So
01287      * we should be put in the default group. */
01288     if (original_src_head != src && dst_head == src) {
01289       SetTrainGroupID(src, DEFAULT_GROUP);
01290       SetWindowDirty(WC_COMPANY, _current_company);
01291     }
01292 
01293     /* Add new heads to statistics */
01294     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01295     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01296 
01297     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01298     NormaliseTrainHead(src_head);
01299     NormaliseTrainHead(dst_head);
01300 
01301     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01302       CheckCargoCapacity(src_head);
01303       CheckCargoCapacity(dst_head);
01304     }
01305 
01306     /* We are undoubtedly changing something in the depot and train list. */
01307     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01308     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01309   } else {
01310     /* We don't want to execute what we're just tried. */
01311     RestoreTrainBackup(original_src);
01312     RestoreTrainBackup(original_dst);
01313   }
01314 
01315   return CommandCost();
01316 }
01317 
01329 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01330 {
01331   /* Check if we deleted a vehicle window */
01332   Window *w = NULL;
01333 
01334   /* Sell a chain of vehicles or not? */
01335   bool sell_chain = HasBit(data, 0);
01336 
01337   Train *v = Train::From(t)->GetFirstEnginePart();
01338   Train *first = v->First();
01339 
01340   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01341 
01342   /* First make a backup of the order of the train. That way we can do
01343    * whatever we want with the order and later on easily revert. */
01344   TrainList original;
01345   MakeTrainBackup(original, first);
01346 
01347   /* We need to keep track of the new head and the head of what we're going to sell. */
01348   Train *new_head = first;
01349   Train *sell_head = NULL;
01350 
01351   /* Split the train in the wanted way. */
01352   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01353 
01354   /* We don't need to validate the second train; it's going to be sold. */
01355   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01356   if (ret.Failed()) {
01357     /* Restore the train we had. */
01358     RestoreTrainBackup(original);
01359     return ret;
01360   }
01361 
01362   CommandCost cost(EXPENSES_NEW_VEHICLES);
01363   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01364 
01365   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01366     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01367   }
01368 
01369   /* do it? */
01370   if (flags & DC_EXEC) {
01371     /* First normalise the sub types of the chain. */
01372     NormaliseSubtypes(new_head);
01373 
01374     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01375       /* We are selling the front engine. In this case we want to
01376        * 'give' the order, unit number and such to the new head. */
01377       new_head->orders.list = first->orders.list;
01378       new_head->AddToShared(first);
01379       DeleteVehicleOrders(first);
01380 
01381       /* Copy other important data from the front engine */
01382       new_head->CopyVehicleConfigAndStatistics(first);
01383       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01384 
01385       /* If we deleted a window then open a new one for the 'new' train */
01386       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01387     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01388       OrderBackup::Backup(v, user);
01389     }
01390 
01391     /* We need to update the information about the train. */
01392     NormaliseTrainHead(new_head);
01393 
01394     /* We are undoubtedly changing something in the depot and train list. */
01395     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01396     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01397 
01398     /* Actually delete the sold 'goods' */
01399     delete sell_head;
01400   } else {
01401     /* We don't want to execute what we're just tried. */
01402     RestoreTrainBackup(original);
01403   }
01404 
01405   return cost;
01406 }
01407 
01408 void Train::UpdateDeltaXY(Direction direction)
01409 {
01410   /* Set common defaults. */
01411   this->x_offs    = -1;
01412   this->y_offs    = -1;
01413   this->x_extent  =  3;
01414   this->y_extent  =  3;
01415   this->z_extent  =  6;
01416   this->x_bb_offs =  0;
01417   this->y_bb_offs =  0;
01418 
01419   if (!IsDiagonalDirection(direction)) {
01420     static const int _sign_table[] =
01421     {
01422       // x, y
01423       -1, -1, // DIR_N
01424       -1,  1, // DIR_E
01425        1,  1, // DIR_S
01426        1, -1, // DIR_W
01427     };
01428 
01429     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01430 
01431     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01432     this->x_offs -= half_shorten * _sign_table[direction];
01433     this->y_offs -= half_shorten * _sign_table[direction + 1];
01434     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01435     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01436   } else {
01437     switch (direction) {
01438         /* Shorten southern corner of the bounding box according the vehicle length
01439          * and center the bounding box on the vehicle. */
01440       case DIR_NE:
01441         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01442         this->x_extent  = this->gcache.cached_veh_length - 1;
01443         this->x_bb_offs = -1;
01444         break;
01445 
01446       case DIR_NW:
01447         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01448         this->y_extent  = this->gcache.cached_veh_length - 1;
01449         this->y_bb_offs = -1;
01450         break;
01451 
01452         /* Move northern corner of the bounding box down according to vehicle length
01453          * and center the bounding box on the vehicle. */
01454       case DIR_SW:
01455         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01456         this->x_extent  = VEHICLE_LENGTH - 1;
01457         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01458         break;
01459 
01460       case DIR_SE:
01461         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01462         this->y_extent  = VEHICLE_LENGTH - 1;
01463         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01464         break;
01465 
01466       default:
01467         NOT_REACHED();
01468     }
01469   }
01470 }
01471 
01476 static void MarkTrainAsStuck(Train *v)
01477 {
01478   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01479     /* It is the first time the problem occurred, set the "train stuck" flag. */
01480     SetBit(v->flags, VRF_TRAIN_STUCK);
01481 
01482     v->wait_counter = 0;
01483 
01484     /* Stop train */
01485     v->cur_speed = 0;
01486     v->subspeed = 0;
01487     v->SetLastSpeed();
01488 
01489     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01490   }
01491 }
01492 
01500 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01501 {
01502   uint16 flag1 = *swap_flag1;
01503   uint16 flag2 = *swap_flag2;
01504 
01505   /* Clear the flags */
01506   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01507   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01508   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01509   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01510 
01511   /* Reverse the rail-flags (if needed) */
01512   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01513     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01514   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01515     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01516   }
01517   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01518     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01519   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01520     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01521   }
01522 }
01523 
01528 static void UpdateStatusAfterSwap(Train *v)
01529 {
01530   /* Reverse the direction. */
01531   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01532 
01533   /* Call the proper EnterTile function unless we are in a wormhole. */
01534   if (v->track != TRACK_BIT_WORMHOLE) {
01535     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01536   } else {
01537     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01538      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01539      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01540      * when we shouldn't have. Check if this is the case. */
01541     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01542     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01543       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01544       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01545         /* We have just left the wormhole, possibly set the
01546          * "goingdown" bit. UpdateInclination() can be used
01547          * because we are at the border of the tile. */
01548         VehicleUpdatePosition(v);
01549         v->UpdateInclination(true, true);
01550         return;
01551       }
01552     }
01553   }
01554 
01555   VehicleUpdatePosition(v);
01556   v->UpdateViewport(true, true);
01557 }
01558 
01565 void ReverseTrainSwapVeh(Train *v, int l, int r)
01566 {
01567   Train *a, *b;
01568 
01569   /* locate vehicles to swap */
01570   for (a = v; l != 0; l--) a = a->Next();
01571   for (b = v; r != 0; r--) b = b->Next();
01572 
01573   if (a != b) {
01574     /* swap the hidden bits */
01575     {
01576       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01577       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01578       a->vehstatus = tmp;
01579     }
01580 
01581     Swap(a->track, b->track);
01582     Swap(a->direction, b->direction);
01583     Swap(a->x_pos, b->x_pos);
01584     Swap(a->y_pos, b->y_pos);
01585     Swap(a->tile,  b->tile);
01586     Swap(a->z_pos, b->z_pos);
01587 
01588     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01589 
01590     UpdateStatusAfterSwap(a);
01591     UpdateStatusAfterSwap(b);
01592   } else {
01593     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01594      * This is a little bit redundant way, a->gv_flags will
01595      * be (re)set twice, but it reduces code duplication */
01596     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01597     UpdateStatusAfterSwap(a);
01598   }
01599 }
01600 
01601 
01607 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01608 {
01609   return (v->type == VEH_TRAIN) ? v : NULL;
01610 }
01611 
01612 
01619 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01620 {
01621   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01622 
01623   Train *t = Train::From(v);
01624   if (!t->IsFrontEngine()) return NULL;
01625 
01626   TileIndex tile = *(TileIndex *)data;
01627 
01628   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01629 
01630   return t;
01631 }
01632 
01633 
01640 static bool TrainApproachingCrossing(TileIndex tile)
01641 {
01642   assert(IsLevelCrossingTile(tile));
01643 
01644   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01645   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01646 
01647   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01648 
01649   dir = ReverseDiagDir(dir);
01650   tile_from = tile + TileOffsByDiagDir(dir);
01651 
01652   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01653 }
01654 
01655 
01662 void UpdateLevelCrossing(TileIndex tile, bool sound)
01663 {
01664   assert(IsLevelCrossingTile(tile));
01665 
01666   /* train on crossing || train approaching crossing || reserved */
01667   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01668 
01669   if (new_state != IsCrossingBarred(tile)) {
01670     if (new_state && sound) {
01671       if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01672     }
01673     SetCrossingBarred(tile, new_state);
01674     MarkTileDirtyByTile(tile);
01675   }
01676 }
01677 
01678 
01684 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01685 {
01686   if (!IsCrossingBarred(tile)) {
01687     BarCrossing(tile);
01688     if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01689     MarkTileDirtyByTile(tile);
01690   }
01691 }
01692 
01693 
01699 static void AdvanceWagonsBeforeSwap(Train *v)
01700 {
01701   Train *base = v;
01702   Train *first = base; // first vehicle to move
01703   Train *last = v->Last(); // last vehicle to move
01704   uint length = CountVehiclesInChain(v);
01705 
01706   while (length > 2) {
01707     last = last->Previous();
01708     first = first->Next();
01709 
01710     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01711 
01712     /* do not update images now
01713      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01714     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01715 
01716     base = first; // == base->Next()
01717     length -= 2;
01718   }
01719 }
01720 
01721 
01727 static void AdvanceWagonsAfterSwap(Train *v)
01728 {
01729   /* first of all, fix the situation when the train was entering a depot */
01730   Train *dep = v; // last vehicle in front of just left depot
01731   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01732     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01733   }
01734 
01735   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01736 
01737   if (leave != NULL) {
01738     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01739     int d = TicksToLeaveDepot(dep);
01740 
01741     if (d <= 0) {
01742       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01743       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01744       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01745     }
01746   } else {
01747     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01748   }
01749 
01750   Train *base = v;
01751   Train *first = base; // first vehicle to move
01752   Train *last = v->Last(); // last vehicle to move
01753   uint length = CountVehiclesInChain(v);
01754 
01755   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01756    * they have already correct spacing, so we have to make sure they are moved how they should */
01757   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01758 
01759   while (length > 2) {
01760     /* we reached vehicle (originally) in front of a depot, stop now
01761      * (we would move wagons that are already moved with new wagon length). */
01762     if (base == dep) break;
01763 
01764     /* the last wagon was that one leaving a depot, so do not move it anymore */
01765     if (last == dep) nomove = true;
01766 
01767     last = last->Previous();
01768     first = first->Next();
01769 
01770     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01771 
01772     /* do not update images now */
01773     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01774 
01775     base = first; // == base->Next()
01776     length -= 2;
01777   }
01778 }
01779 
01784 void ReverseTrainDirection(Train *v)
01785 {
01786   if (IsRailDepotTile(v->tile)) {
01787     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01788   }
01789 
01790   /* Clear path reservation in front if train is not stuck. */
01791   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01792 
01793   /* Check if we were approaching a rail/road-crossing */
01794   TileIndex crossing = TrainApproachingCrossingTile(v);
01795 
01796   /* count number of vehicles */
01797   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01798 
01799   AdvanceWagonsBeforeSwap(v);
01800 
01801   /* swap start<>end, start+1<>end-1, ... */
01802   int l = 0;
01803   do {
01804     ReverseTrainSwapVeh(v, l++, r--);
01805   } while (l <= r);
01806 
01807   AdvanceWagonsAfterSwap(v);
01808 
01809   if (IsRailDepotTile(v->tile)) {
01810     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01811   }
01812 
01813   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01814 
01815   ClrBit(v->flags, VRF_REVERSING);
01816 
01817   /* recalculate cached data */
01818   v->ConsistChanged(true);
01819 
01820   /* update all images */
01821   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01822 
01823   /* update crossing we were approaching */
01824   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01825 
01826   /* maybe we are approaching crossing now, after reversal */
01827   crossing = TrainApproachingCrossingTile(v);
01828   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01829 
01830   /* If we are inside a depot after reversing, don't bother with path reserving. */
01831   if (v->track == TRACK_BIT_DEPOT) {
01832     /* Can't be stuck here as inside a depot is always a safe tile. */
01833     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01834     ClrBit(v->flags, VRF_TRAIN_STUCK);
01835     return;
01836   }
01837 
01838   /* TrainExitDir does not always produce the desired dir for depots and
01839    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01840   DiagDirection dir = TrainExitDir(v->direction, v->track);
01841   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01842 
01843   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01844     /* If we are currently on a tile with conventional signals, we can't treat the
01845      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01846     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01847       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01848       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01849 
01850     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01851     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01852 
01853     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01854     if (TryPathReserve(v, false, first_tile_okay)) {
01855       /* Do a look-ahead now in case our current tile was already a safe tile. */
01856       CheckNextTrainTile(v);
01857     } else if (v->current_order.GetType() != OT_LOADING) {
01858       /* Do not wait for a way out when we're still loading */
01859       MarkTrainAsStuck(v);
01860     }
01861   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01862     /* A train not inside a PBS block can't be stuck. */
01863     ClrBit(v->flags, VRF_TRAIN_STUCK);
01864     v->wait_counter = 0;
01865   }
01866 }
01867 
01877 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01878 {
01879   Train *v = Train::GetIfValid(p1);
01880   if (v == NULL) return CMD_ERROR;
01881 
01882   CommandCost ret = CheckOwnership(v->owner);
01883   if (ret.Failed()) return ret;
01884 
01885   if (p2 != 0) {
01886     /* turn a single unit around */
01887 
01888     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01889       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01890     }
01891     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01892 
01893     Train *front = v->First();
01894     /* make sure the vehicle is stopped in the depot */
01895     if (!front->IsStoppedInDepot()) {
01896       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01897     }
01898 
01899     if (flags & DC_EXEC) {
01900       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01901 
01902       front->ConsistChanged(false);
01903       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01904       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01905       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01906       SetWindowClassesDirty(WC_TRAINS_LIST);
01907     }
01908   } else {
01909     /* turn the whole train around */
01910     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01911 
01912     if (flags & DC_EXEC) {
01913       /* Properly leave the station if we are loading and won't be loading anymore */
01914       if (v->current_order.IsType(OT_LOADING)) {
01915         const Vehicle *last = v;
01916         while (last->Next() != NULL) last = last->Next();
01917 
01918         /* not a station || different station --> leave the station */
01919         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01920           v->LeaveStation();
01921         }
01922       }
01923 
01924       /* We cancel any 'skip signal at dangers' here */
01925       v->force_proceed = TFP_NONE;
01926       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01927 
01928       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01929         ToggleBit(v->flags, VRF_REVERSING);
01930       } else {
01931         v->cur_speed = 0;
01932         v->SetLastSpeed();
01933         HideFillingPercent(&v->fill_percent_te_id);
01934         ReverseTrainDirection(v);
01935       }
01936     }
01937   }
01938   return CommandCost();
01939 }
01940 
01950 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01951 {
01952   Train *t = Train::GetIfValid(p1);
01953   if (t == NULL) return CMD_ERROR;
01954 
01955   if (!t->IsPrimaryVehicle()) return CMD_ERROR;
01956 
01957   CommandCost ret = CheckOwnership(t->owner);
01958   if (ret.Failed()) return ret;
01959 
01960 
01961   if (flags & DC_EXEC) {
01962     /* If we are forced to proceed, cancel that order.
01963      * If we are marked stuck we would want to force the train
01964      * to proceed to the next signal. In the other cases we
01965      * would like to pass the signal at danger and run till the
01966      * next signal we encounter. */
01967     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsChainInDepot() ? TFP_STUCK : TFP_SIGNAL;
01968     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01969   }
01970 
01971   return CommandCost();
01972 }
01973 
01981 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01982 {
01983   assert(!(v->vehstatus & VS_CRASHED));
01984 
01985   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01986 
01987   PBSTileInfo origin = FollowTrainReservation(v);
01988   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01989 
01990   switch (_settings_game.pf.pathfinder_for_trains) {
01991     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01992     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01993 
01994     default: NOT_REACHED();
01995   }
01996 }
01997 
02005 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
02006 {
02007   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
02008   if (tfdd.best_length == UINT_MAX) return false;
02009 
02010   if (location    != NULL) *location    = tfdd.tile;
02011   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
02012   if (reverse     != NULL) *reverse     = tfdd.reverse;
02013 
02014   return true;
02015 }
02016 
02018 void Train::PlayLeaveStationSound() const
02019 {
02020   static const SoundFx sfx[] = {
02021     SND_04_TRAIN,
02022     SND_0A_TRAIN_HORN,
02023     SND_0A_TRAIN_HORN,
02024     SND_47_MAGLEV_2,
02025     SND_41_MAGLEV
02026   };
02027 
02028   if (PlayVehicleSound(this, VSE_START)) return;
02029 
02030   EngineID engtype = this->engine_type;
02031   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02032 }
02033 
02038 static void CheckNextTrainTile(Train *v)
02039 {
02040   /* Don't do any look-ahead if path_backoff_interval is 255. */
02041   if (_settings_game.pf.path_backoff_interval == 255) return;
02042 
02043   /* Exit if we are inside a depot. */
02044   if (v->track == TRACK_BIT_DEPOT) return;
02045 
02046   switch (v->current_order.GetType()) {
02047     /* Exit if we reached our destination depot. */
02048     case OT_GOTO_DEPOT:
02049       if (v->tile == v->dest_tile) return;
02050       break;
02051 
02052     case OT_GOTO_WAYPOINT:
02053       /* If we reached our waypoint, make sure we see that. */
02054       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02055       break;
02056 
02057     case OT_NOTHING:
02058     case OT_LEAVESTATION:
02059     case OT_LOADING:
02060       /* Exit if the current order doesn't have a destination, but the train has orders. */
02061       if (v->GetNumOrders() > 0) return;
02062       break;
02063 
02064     default:
02065       break;
02066   }
02067   /* Exit if we are on a station tile and are going to stop. */
02068   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02069 
02070   Trackdir td = v->GetVehicleTrackdir();
02071 
02072   /* On a tile with a red non-pbs signal, don't look ahead. */
02073   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02074       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02075       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02076 
02077   CFollowTrackRail ft(v);
02078   if (!ft.Follow(v->tile, td)) return;
02079 
02080   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02081     /* Next tile is not reserved. */
02082     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02083       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02084         /* If the next tile is a PBS signal, try to make a reservation. */
02085         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02086         if (_settings_game.pf.forbid_90_deg) {
02087           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02088         }
02089         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02090       }
02091     }
02092   }
02093 }
02094 
02100 static bool CheckTrainStayInDepot(Train *v)
02101 {
02102   /* bail out if not all wagons are in the same depot or not in a depot at all */
02103   for (const Train *u = v; u != NULL; u = u->Next()) {
02104     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02105   }
02106 
02107   /* if the train got no power, then keep it in the depot */
02108   if (v->gcache.cached_power == 0) {
02109     v->vehstatus |= VS_STOPPED;
02110     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02111     return true;
02112   }
02113 
02114   SigSegState seg_state;
02115 
02116   if (v->force_proceed == TFP_NONE) {
02117     /* force proceed was not pressed */
02118     if (++v->wait_counter < 37) {
02119       SetWindowClassesDirty(WC_TRAINS_LIST);
02120       return true;
02121     }
02122 
02123     v->wait_counter = 0;
02124 
02125     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02126     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02127       /* Full and no PBS signal in block or depot reserved, can't exit. */
02128       SetWindowClassesDirty(WC_TRAINS_LIST);
02129       return true;
02130     }
02131   } else {
02132     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02133   }
02134 
02135   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02136   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02137     /* We need to have a reservation for this to work. */
02138     if (HasDepotReservation(v->tile)) return true;
02139     SetDepotReservation(v->tile, true);
02140     VehicleEnterDepot(v);
02141     return true;
02142   }
02143 
02144   /* Only leave when we can reserve a path to our destination. */
02145   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02146     /* No path and no force proceed. */
02147     SetWindowClassesDirty(WC_TRAINS_LIST);
02148     MarkTrainAsStuck(v);
02149     return true;
02150   }
02151 
02152   SetDepotReservation(v->tile, true);
02153   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02154 
02155   VehicleServiceInDepot(v);
02156   SetWindowClassesDirty(WC_TRAINS_LIST);
02157   v->PlayLeaveStationSound();
02158 
02159   v->track = TRACK_BIT_X;
02160   if (v->direction & 2) v->track = TRACK_BIT_Y;
02161 
02162   v->vehstatus &= ~VS_HIDDEN;
02163   v->cur_speed = 0;
02164 
02165   v->UpdateViewport(true, true);
02166   VehicleUpdatePosition(v);
02167   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02168   v->UpdateAcceleration();
02169   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02170 
02171   return false;
02172 }
02173 
02180 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02181 {
02182   DiagDirection dir = TrackdirToExitdir(track_dir);
02183 
02184   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02185     /* Are we just leaving a tunnel/bridge? */
02186     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02187       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02188 
02189       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02190         /* Free the reservation only if no other train is on the tiles. */
02191         SetTunnelBridgeReservation(tile, false);
02192         SetTunnelBridgeReservation(end, false);
02193 
02194         if (_settings_client.gui.show_track_reservation) {
02195           MarkTileDirtyByTile(tile);
02196           MarkTileDirtyByTile(end);
02197         }
02198       }
02199     }
02200   } else if (IsRailStationTile(tile)) {
02201     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02202     /* If the new tile is not a further tile of the same station, we
02203      * clear the reservation for the whole platform. */
02204     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02205       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02206     }
02207   } else {
02208     /* Any other tile */
02209     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02210   }
02211 }
02212 
02219 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02220 {
02221   assert(v->IsFrontEngine());
02222 
02223   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02224   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02225   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02226   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02227 
02228   /* Can't be holding a reservation if we enter a depot. */
02229   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02230   if (v->track == TRACK_BIT_DEPOT) {
02231     /* Front engine is in a depot. We enter if some part is not in the depot. */
02232     for (const Train *u = v; u != NULL; u = u->Next()) {
02233       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02234     }
02235   }
02236   /* Don't free reservation if it's not ours. */
02237   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02238 
02239   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02240   while (ft.Follow(tile, td)) {
02241     tile = ft.m_new_tile;
02242     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02243     td = RemoveFirstTrackdir(&bits);
02244     assert(bits == TRACKDIR_BIT_NONE);
02245 
02246     if (!IsValidTrackdir(td)) break;
02247 
02248     if (IsTileType(tile, MP_RAILWAY)) {
02249       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02250         /* Conventional signal along trackdir: remove reservation and stop. */
02251         UnreserveRailTrack(tile, TrackdirToTrack(td));
02252         break;
02253       }
02254       if (HasPbsSignalOnTrackdir(tile, td)) {
02255         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02256           /* Red PBS signal? Can't be our reservation, would be green then. */
02257           break;
02258         } else {
02259           /* Turn the signal back to red. */
02260           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02261           MarkTileDirtyByTile(tile);
02262         }
02263       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02264         break;
02265       }
02266     }
02267 
02268     /* Don't free first station/bridge/tunnel if we are on it. */
02269     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);
02270 
02271     free_tile = true;
02272   }
02273 }
02274 
02275 static const byte _initial_tile_subcoord[6][4][3] = {
02276 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02277 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02278 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02279 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02280 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02281 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02282 };
02283 
02296 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02297 {
02298   switch (_settings_game.pf.pathfinder_for_trains) {
02299     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02300     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02301 
02302     default: NOT_REACHED();
02303   }
02304 }
02305 
02311 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02312 {
02313   PBSTileInfo origin = FollowTrainReservation(v);
02314 
02315   CFollowTrackRail ft(v);
02316 
02317   TileIndex tile = origin.tile;
02318   Trackdir  cur_td = origin.trackdir;
02319   while (ft.Follow(tile, cur_td)) {
02320     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02321       /* Possible signal tile. */
02322       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02323     }
02324 
02325     if (_settings_game.pf.forbid_90_deg) {
02326       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02327       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02328     }
02329 
02330     /* Station, depot or waypoint are a possible target. */
02331     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02332     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02333       /* Choice found or possible target encountered.
02334        * On finding a possible target, we need to stop and let the pathfinder handle the
02335        * remaining path. This is because we don't know if this target is in one of our
02336        * orders, so we might cause pathfinding to fail later on if we find a choice.
02337        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02338        * a wrong path not leading to our next destination. */
02339       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02340 
02341       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02342        * actually starts its search at the first unreserved tile. */
02343       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02344 
02345       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02346       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02347       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02348       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02349     }
02350 
02351     tile = ft.m_new_tile;
02352     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02353 
02354     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02355       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02356       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02357       /* Safe position is all good, path valid and okay. */
02358       return PBSTileInfo(tile, cur_td, true);
02359     }
02360 
02361     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02362   }
02363 
02364   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02365     /* End of line, path valid and okay. */
02366     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02367   }
02368 
02369   /* Sorry, can't reserve path, back out. */
02370   tile = origin.tile;
02371   cur_td = origin.trackdir;
02372   TileIndex stopped = ft.m_old_tile;
02373   Trackdir  stopped_td = ft.m_old_td;
02374   while (tile != stopped || cur_td != stopped_td) {
02375     if (!ft.Follow(tile, cur_td)) break;
02376 
02377     if (_settings_game.pf.forbid_90_deg) {
02378       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02379       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02380     }
02381     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02382 
02383     tile = ft.m_new_tile;
02384     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02385 
02386     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02387   }
02388 
02389   /* Path invalid. */
02390   return PBSTileInfo();
02391 }
02392 
02403 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02404 {
02405   switch (_settings_game.pf.pathfinder_for_trains) {
02406     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02407     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02408 
02409     default: NOT_REACHED();
02410   }
02411 }
02412 
02414 class VehicleOrderSaver {
02415 private:
02416   Train          *v;
02417   Order          old_order;
02418   TileIndex      old_dest_tile;
02419   StationID      old_last_station_visited;
02420   VehicleOrderID index;
02421   bool           suppress_implicit_orders;
02422 
02423 public:
02424   VehicleOrderSaver(Train *_v) :
02425     v(_v),
02426     old_order(_v->current_order),
02427     old_dest_tile(_v->dest_tile),
02428     old_last_station_visited(_v->last_station_visited),
02429     index(_v->cur_real_order_index),
02430     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02431   {
02432   }
02433 
02434   ~VehicleOrderSaver()
02435   {
02436     this->v->current_order = this->old_order;
02437     this->v->dest_tile = this->old_dest_tile;
02438     this->v->last_station_visited = this->old_last_station_visited;
02439     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02440   }
02441 
02447   bool SwitchToNextOrder(bool skip_first)
02448   {
02449     if (this->v->GetNumOrders() == 0) return false;
02450 
02451     if (skip_first) ++this->index;
02452 
02453     int depth = 0;
02454 
02455     do {
02456       /* Wrap around. */
02457       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02458 
02459       Order *order = this->v->GetOrder(this->index);
02460       assert(order != NULL);
02461 
02462       switch (order->GetType()) {
02463         case OT_GOTO_DEPOT:
02464           /* Skip service in depot orders when the train doesn't need service. */
02465           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02466         case OT_GOTO_STATION:
02467         case OT_GOTO_WAYPOINT:
02468           this->v->current_order = *order;
02469           return UpdateOrderDest(this->v, order, 0, true);
02470         case OT_CONDITIONAL: {
02471           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02472           if (next != INVALID_VEH_ORDER_ID) {
02473             depth++;
02474             this->index = next;
02475             /* Don't increment next, so no break here. */
02476             continue;
02477           }
02478           break;
02479         }
02480         default:
02481           break;
02482       }
02483       /* Don't increment inside the while because otherwise conditional
02484        * orders can lead to an infinite loop. */
02485       ++this->index;
02486       depth++;
02487     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02488 
02489     return false;
02490   }
02491 };
02492 
02493 /* choose a track */
02494 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02495 {
02496   Track best_track = INVALID_TRACK;
02497   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02498   bool changed_signal = false;
02499 
02500   assert((tracks & ~TRACK_BIT_MASK) == 0);
02501 
02502   if (got_reservation != NULL) *got_reservation = false;
02503 
02504   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02505   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02506   /* Do we have a suitable reserved track? */
02507   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02508 
02509   /* Quick return in case only one possible track is available */
02510   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02511     Track track = FindFirstTrack(tracks);
02512     /* We need to check for signals only here, as a junction tile can't have signals. */
02513     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02514       do_track_reservation = true;
02515       changed_signal = true;
02516       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02517     } else if (!do_track_reservation) {
02518       return track;
02519     }
02520     best_track = track;
02521   }
02522 
02523   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02524   DiagDirection dest_enterdir = enterdir;
02525   if (do_track_reservation) {
02526     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02527     if (res_dest.tile == INVALID_TILE) {
02528       /* Reservation failed? */
02529       if (mark_stuck) MarkTrainAsStuck(v);
02530       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02531       return FindFirstTrack(tracks);
02532     }
02533     if (res_dest.okay) {
02534       /* Got a valid reservation that ends at a safe target, quick exit. */
02535       if (got_reservation != NULL) *got_reservation = true;
02536       if (changed_signal) MarkTileDirtyByTile(tile);
02537       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02538       return best_track;
02539     }
02540 
02541     /* Check if the train needs service here, so it has a chance to always find a depot.
02542      * Also check if the current order is a service order so we don't reserve a path to
02543      * the destination but instead to the next one if service isn't needed. */
02544     CheckIfTrainNeedsService(v);
02545     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02546   }
02547 
02548   /* Save the current train order. The destructor will restore the old order on function exit. */
02549   VehicleOrderSaver orders(v);
02550 
02551   /* If the current tile is the destination of the current order and
02552    * a reservation was requested, advance to the next order.
02553    * Don't advance on a depot order as depots are always safe end points
02554    * for a path and no look-ahead is necessary. This also avoids a
02555    * problem with depot orders not part of the order list when the
02556    * order list itself is empty. */
02557   if (v->current_order.IsType(OT_LEAVESTATION)) {
02558     orders.SwitchToNextOrder(false);
02559   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02560       v->current_order.IsType(OT_GOTO_STATION) ?
02561       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02562       v->tile == v->dest_tile))) {
02563     orders.SwitchToNextOrder(true);
02564   }
02565 
02566   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02567     /* Pathfinders are able to tell that route was only 'guessed'. */
02568     bool      path_found = true;
02569     TileIndex new_tile = res_dest.tile;
02570 
02571     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02572     if (new_tile == tile) best_track = next_track;
02573     v->HandlePathfindingResult(path_found);
02574   }
02575 
02576   /* No track reservation requested -> finished. */
02577   if (!do_track_reservation) return best_track;
02578 
02579   /* A path was found, but could not be reserved. */
02580   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02581     if (mark_stuck) MarkTrainAsStuck(v);
02582     FreeTrainTrackReservation(v);
02583     return best_track;
02584   }
02585 
02586   /* No possible reservation target found, we are probably lost. */
02587   if (res_dest.tile == INVALID_TILE) {
02588     /* Try to find any safe destination. */
02589     PBSTileInfo origin = FollowTrainReservation(v);
02590     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02591       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02592       best_track = FindFirstTrack(res);
02593       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02594       if (got_reservation != NULL) *got_reservation = true;
02595       if (changed_signal) MarkTileDirtyByTile(tile);
02596     } else {
02597       FreeTrainTrackReservation(v);
02598       if (mark_stuck) MarkTrainAsStuck(v);
02599     }
02600     return best_track;
02601   }
02602 
02603   if (got_reservation != NULL) *got_reservation = true;
02604 
02605   /* Reservation target found and free, check if it is safe. */
02606   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02607     /* Extend reservation until we have found a safe position. */
02608     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02609     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02610     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02611     if (_settings_game.pf.forbid_90_deg) {
02612       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02613     }
02614 
02615     /* Get next order with destination. */
02616     if (orders.SwitchToNextOrder(true)) {
02617       PBSTileInfo cur_dest;
02618       bool path_found;
02619       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02620       if (cur_dest.tile != INVALID_TILE) {
02621         res_dest = cur_dest;
02622         if (res_dest.okay) continue;
02623         /* Path found, but could not be reserved. */
02624         FreeTrainTrackReservation(v);
02625         if (mark_stuck) MarkTrainAsStuck(v);
02626         if (got_reservation != NULL) *got_reservation = false;
02627         changed_signal = false;
02628         break;
02629       }
02630     }
02631     /* No order or no safe position found, try any position. */
02632     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02633       FreeTrainTrackReservation(v);
02634       if (mark_stuck) MarkTrainAsStuck(v);
02635       if (got_reservation != NULL) *got_reservation = false;
02636       changed_signal = false;
02637     }
02638     break;
02639   }
02640 
02641   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02642 
02643   if (changed_signal) MarkTileDirtyByTile(tile);
02644 
02645   return best_track;
02646 }
02647 
02656 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02657 {
02658   assert(v->IsFrontEngine());
02659 
02660   /* We have to handle depots specially as the track follower won't look
02661    * at the depot tile itself but starts from the next tile. If we are still
02662    * inside the depot, a depot reservation can never be ours. */
02663   if (v->track == TRACK_BIT_DEPOT) {
02664     if (HasDepotReservation(v->tile)) {
02665       if (mark_as_stuck) MarkTrainAsStuck(v);
02666       return false;
02667     } else {
02668       /* Depot not reserved, but the next tile might be. */
02669       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02670       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02671     }
02672   }
02673 
02674   Vehicle *other_train = NULL;
02675   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02676   /* The path we are driving on is already blocked by some other train.
02677    * This can only happen in certain situations when mixing path and
02678    * block signals or when changing tracks and/or signals.
02679    * Exit here as doing any further reservations will probably just
02680    * make matters worse. */
02681   if (other_train != NULL && other_train->index != v->index) {
02682     if (mark_as_stuck) MarkTrainAsStuck(v);
02683     return false;
02684   }
02685   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02686   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02687     /* Can't be stuck then. */
02688     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02689     ClrBit(v->flags, VRF_TRAIN_STUCK);
02690     return true;
02691   }
02692 
02693   /* If we are in a depot, tentatively reserve the depot. */
02694   if (v->track == TRACK_BIT_DEPOT) {
02695     SetDepotReservation(v->tile, true);
02696     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02697   }
02698 
02699   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02700   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02701   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02702 
02703   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02704 
02705   bool res_made = false;
02706   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02707 
02708   if (!res_made) {
02709     /* Free the depot reservation as well. */
02710     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02711     return false;
02712   }
02713 
02714   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02715     v->wait_counter = 0;
02716     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02717   }
02718   ClrBit(v->flags, VRF_TRAIN_STUCK);
02719   return true;
02720 }
02721 
02722 
02723 static bool CheckReverseTrain(const Train *v)
02724 {
02725   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02726       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02727       !(v->direction & 1)) {
02728     return false;
02729   }
02730 
02731   assert(v->track != TRACK_BIT_NONE);
02732 
02733   switch (_settings_game.pf.pathfinder_for_trains) {
02734     case VPF_NPF: return NPFTrainCheckReverse(v);
02735     case VPF_YAPF: return YapfTrainCheckReverse(v);
02736 
02737     default: NOT_REACHED();
02738   }
02739 }
02740 
02746 TileIndex Train::GetOrderStationLocation(StationID station)
02747 {
02748   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02749 
02750   const Station *st = Station::Get(station);
02751   if (!(st->facilities & FACIL_TRAIN)) {
02752     /* The destination station has no trainstation tiles. */
02753     this->IncrementRealOrderIndex();
02754     return 0;
02755   }
02756 
02757   return st->xy;
02758 }
02759 
02761 void Train::MarkDirty()
02762 {
02763   Train *v = this;
02764   do {
02765     v->UpdateViewport(false, false);
02766   } while ((v = v->Next()) != NULL);
02767 
02768   /* need to update acceleration and cached values since the goods on the train changed. */
02769   this->CargoChanged();
02770   this->UpdateAcceleration();
02771 }
02772 
02780 int Train::UpdateSpeed()
02781 {
02782   switch (_settings_game.vehicle.train_acceleration_model) {
02783     default: NOT_REACHED();
02784     case AM_ORIGINAL:
02785       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, this->GetCurrentMaxSpeed());
02786 
02787     case AM_REALISTIC:
02788       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02789   }
02790 }
02791 
02797 static void TrainEnterStation(Train *v, StationID station)
02798 {
02799   v->last_station_visited = station;
02800 
02801   /* check if a train ever visited this station before */
02802   Station *st = Station::Get(station);
02803   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02804     st->had_vehicle_of_type |= HVOT_TRAIN;
02805     SetDParam(0, st->index);
02806     AddVehicleNewsItem(
02807       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02808       v->owner == _local_company ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
02809       v->index,
02810       st->index
02811     );
02812     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02813     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02814   }
02815 
02816   v->force_proceed = TFP_NONE;
02817   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02818 
02819   v->BeginLoading();
02820 
02821   TriggerStationRandomisation(st, v->tile, SRT_TRAIN_ARRIVES);
02822   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02823 }
02824 
02825 /* Check if the vehicle is compatible with the specified tile */
02826 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02827 {
02828   return IsTileOwner(tile, v->owner) &&
02829       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02830 }
02831 
02833 struct AccelerationSlowdownParams {
02834   byte small_turn; 
02835   byte large_turn; 
02836   byte z_up;       
02837   byte z_down;     
02838 };
02839 
02841 static const AccelerationSlowdownParams _accel_slowdown[] = {
02842   /* normal accel */
02843   {256 / 4, 256 / 2, 256 / 4, 2}, 
02844   {256 / 4, 256 / 2, 256 / 4, 2}, 
02845   {0,       256 / 2, 256 / 4, 2}, 
02846 };
02847 
02853 static inline void AffectSpeedByZChange(Train *v, int old_z)
02854 {
02855   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02856 
02857   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02858 
02859   if (old_z < v->z_pos) {
02860     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02861   } else {
02862     uint16 spd = v->cur_speed + asp->z_down;
02863     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02864   }
02865 }
02866 
02867 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02868 {
02869   if (IsTileType(tile, MP_RAILWAY) &&
02870       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02871     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02872     Trackdir trackdir = FindFirstTrackdir(tracks);
02873     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02874       /* A PBS block with a non-PBS signal facing us? */
02875       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02876     }
02877   }
02878   return false;
02879 }
02880 
02882 void Train::ReserveTrackUnderConsist() const
02883 {
02884   for (const Train *u = this; u != NULL; u = u->Next()) {
02885     switch (u->track) {
02886       case TRACK_BIT_WORMHOLE:
02887         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02888         break;
02889       case TRACK_BIT_DEPOT:
02890         break;
02891       default:
02892         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02893         break;
02894     }
02895   }
02896 }
02897 
02904 uint Train::Crash(bool flooded)
02905 {
02906   uint pass = 0;
02907   if (this->IsFrontEngine()) {
02908     pass += 2; // driver
02909 
02910     /* Remove the reserved path in front of the train if it is not stuck.
02911      * Also clear all reserved tracks the train is currently on. */
02912     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02913     for (const Train *v = this; v != NULL; v = v->Next()) {
02914       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02915       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02916         /* ClearPathReservation will not free the wormhole exit
02917          * if the train has just entered the wormhole. */
02918         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02919       }
02920     }
02921 
02922     /* we may need to update crossing we were approaching,
02923      * but must be updated after the train has been marked crashed */
02924     TileIndex crossing = TrainApproachingCrossingTile(this);
02925     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02926 
02927     /* Remove the loading indicators (if any) */
02928     HideFillingPercent(&this->fill_percent_te_id);
02929   }
02930 
02931   pass += this->GroundVehicleBase::Crash(flooded);
02932 
02933   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02934   return pass;
02935 }
02936 
02943 static uint TrainCrashed(Train *v)
02944 {
02945   uint num = 0;
02946 
02947   /* do not crash train twice */
02948   if (!(v->vehstatus & VS_CRASHED)) {
02949     num = v->Crash();
02950     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02951     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02952   }
02953 
02954   /* Try to re-reserve track under already crashed train too.
02955    * Crash() clears the reservation! */
02956   v->ReserveTrackUnderConsist();
02957 
02958   return num;
02959 }
02960 
02962 struct TrainCollideChecker {
02963   Train *v; 
02964   uint num; 
02965 };
02966 
02973 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02974 {
02975   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02976 
02977   /* not a train or in depot */
02978   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02979 
02980   /* do not crash into trains of another company. */
02981   if (v->owner != tcc->v->owner) return NULL;
02982 
02983   /* get first vehicle now to make most usual checks faster */
02984   Train *coll = Train::From(v)->First();
02985 
02986   /* can't collide with own wagons */
02987   if (coll == tcc->v) return NULL;
02988 
02989   int x_diff = v->x_pos - tcc->v->x_pos;
02990   int y_diff = v->y_pos - tcc->v->y_pos;
02991 
02992   /* Do fast calculation to check whether trains are not in close vicinity
02993    * and quickly reject trains distant enough for any collision.
02994    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02995    * Differences are then ORed and then we check for any higher bits */
02996   uint hash = (y_diff + 7) | (x_diff + 7);
02997   if (hash & ~15) return NULL;
02998 
02999   /* Slower check using multiplication */
03000   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
03001   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
03002 
03003   /* Happens when there is a train under bridge next to bridge head */
03004   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
03005 
03006   /* crash both trains */
03007   tcc->num += TrainCrashed(tcc->v);
03008   tcc->num += TrainCrashed(coll);
03009 
03010   return NULL; // continue searching
03011 }
03012 
03020 static bool CheckTrainCollision(Train *v)
03021 {
03022   /* can't collide in depot */
03023   if (v->track == TRACK_BIT_DEPOT) return false;
03024 
03025   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03026 
03027   TrainCollideChecker tcc;
03028   tcc.v = v;
03029   tcc.num = 0;
03030 
03031   /* find colliding vehicles */
03032   if (v->track == TRACK_BIT_WORMHOLE) {
03033     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03034     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03035   } else {
03036     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03037   }
03038 
03039   /* any dead -> no crash */
03040   if (tcc.num == 0) return false;
03041 
03042   SetDParam(0, tcc.num);
03043   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH, NT_ACCIDENT, v->index);
03044 
03045   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03046   if (_settings_client.sound.disaster) SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03047   return true;
03048 }
03049 
03050 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03051 {
03052   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03053 
03054   Train *t = Train::From(v);
03055   DiagDirection exitdir = *(DiagDirection *)data;
03056 
03057   /* not front engine of a train, inside wormhole or depot, crashed */
03058   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03059 
03060   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03061 
03062   return t;
03063 }
03064 
03072 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03073 {
03074   Train *first = v->First();
03075   Train *prev;
03076   bool direction_changed = false; // has direction of any part changed?
03077 
03078   /* For every vehicle after and including the given vehicle */
03079   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03080     DiagDirection enterdir = DIAGDIR_BEGIN;
03081     bool update_signals_crossing = false; // will we update signals or crossing state?
03082 
03083     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03084     if (v->track != TRACK_BIT_WORMHOLE) {
03085       /* Not inside tunnel */
03086       if (gp.old_tile == gp.new_tile) {
03087         /* Staying in the old tile */
03088         if (v->track == TRACK_BIT_DEPOT) {
03089           /* Inside depot */
03090           gp.x = v->x_pos;
03091           gp.y = v->y_pos;
03092         } else {
03093           /* Not inside depot */
03094 
03095           /* Reverse when we are at the end of the track already, do not move to the new position */
03096           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03097 
03098           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03099           if (HasBit(r, VETS_CANNOT_ENTER)) {
03100             goto invalid_rail;
03101           }
03102           if (HasBit(r, VETS_ENTERED_STATION)) {
03103             /* The new position is the end of the platform */
03104             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03105           }
03106         }
03107       } else {
03108         /* A new tile is about to be entered. */
03109 
03110         /* Determine what direction we're entering the new tile from */
03111         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03112         assert(IsValidDiagDirection(enterdir));
03113 
03114         /* Get the status of the tracks in the new tile and mask
03115          * away the bits that aren't reachable. */
03116         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03117         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03118 
03119         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03120         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03121 
03122         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03123         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03124           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03125            * can be switched on halfway a turn */
03126           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03127         }
03128 
03129         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03130 
03131         /* Check if the new tile constrains tracks that are compatible
03132          * with the current train, if not, bail out. */
03133         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03134 
03135         TrackBits chosen_track;
03136         if (prev == NULL) {
03137           /* Currently the locomotive is active. Determine which one of the
03138            * available tracks to choose */
03139           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03140           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03141 
03142           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03143             /* For each signal we find decrease the counter by one.
03144              * We start at two, so the first signal we pass decreases
03145              * this to one, then if we reach the next signal it is
03146              * decreased to zero and we won't pass that new signal. */
03147             Trackdir dir = FindFirstTrackdir(trackdirbits);
03148             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03149                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03150               /* However, we do not want to be stopped by PBS signals
03151                * entered via the back. */
03152               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03153               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03154             }
03155           }
03156 
03157           /* Check if it's a red signal and that force proceed is not clicked. */
03158           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03159             /* In front of a red signal */
03160             Trackdir i = FindFirstTrackdir(trackdirbits);
03161 
03162             /* Don't handle stuck trains here. */
03163             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03164 
03165             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03166               v->cur_speed = 0;
03167               v->subspeed = 0;
03168               v->progress = 255 - 100;
03169               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03170             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03171               v->cur_speed = 0;
03172               v->subspeed = 0;
03173               v->progress = 255 - 10;
03174               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03175                 DiagDirection exitdir = TrackdirToExitdir(i);
03176                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03177 
03178                 exitdir = ReverseDiagDir(exitdir);
03179 
03180                 /* check if a train is waiting on the other side */
03181                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03182               }
03183             }
03184 
03185             /* If we would reverse but are currently in a PBS block and
03186              * reversing of stuck trains is disabled, don't reverse.
03187              * This does not apply if the reason for reversing is a one-way
03188              * signal blocking us, because a train would then be stuck forever. */
03189             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03190                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03191               v->wait_counter = 0;
03192               return false;
03193             }
03194             goto reverse_train_direction;
03195           } else {
03196             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track), false);
03197           }
03198         } else {
03199           /* The wagon is active, simply follow the prev vehicle. */
03200           if (prev->tile == gp.new_tile) {
03201             /* Choose the same track as prev */
03202             if (prev->track == TRACK_BIT_WORMHOLE) {
03203               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03204                * However, just choose the track into the wormhole. */
03205               assert(IsTunnel(prev->tile));
03206               chosen_track = bits;
03207             } else {
03208               chosen_track = prev->track;
03209             }
03210           } else {
03211             /* Choose the track that leads to the tile where prev is.
03212              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03213              * I.e. when the tile between them has only space for a single vehicle like
03214              *  1) horizontal/vertical track tiles and
03215              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03216              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03217              */
03218             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03219               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03220               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03221               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03222               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03223             };
03224             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03225             assert(IsValidDiagDirection(exitdir));
03226             chosen_track = _connecting_track[enterdir][exitdir];
03227           }
03228           chosen_track &= bits;
03229         }
03230 
03231         /* Make sure chosen track is a valid track */
03232         assert(
03233             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03234             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03235             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03236 
03237         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03238         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03239         gp.x = (gp.x & ~0xF) | b[0];
03240         gp.y = (gp.y & ~0xF) | b[1];
03241         Direction chosen_dir = (Direction)b[2];
03242 
03243         /* Call the landscape function and tell it that the vehicle entered the tile */
03244         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03245         if (HasBit(r, VETS_CANNOT_ENTER)) {
03246           goto invalid_rail;
03247         }
03248 
03249         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03250           Track track = FindFirstTrack(chosen_track);
03251           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03252           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03253             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03254             MarkTileDirtyByTile(gp.new_tile);
03255           }
03256 
03257           /* Clear any track reservation when the last vehicle leaves the tile */
03258           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03259 
03260           v->tile = gp.new_tile;
03261 
03262           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03263             v->First()->ConsistChanged(true);
03264           }
03265 
03266           v->track = chosen_track;
03267           assert(v->track);
03268         }
03269 
03270         /* We need to update signal status, but after the vehicle position hash
03271          * has been updated by UpdateInclination() */
03272         update_signals_crossing = true;
03273 
03274         if (chosen_dir != v->direction) {
03275           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03276             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03277             DirDiff diff = DirDifference(v->direction, chosen_dir);
03278             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03279           }
03280           direction_changed = true;
03281           v->direction = chosen_dir;
03282         }
03283 
03284         if (v->IsFrontEngine()) {
03285           v->wait_counter = 0;
03286 
03287           /* If we are approaching a crossing that is reserved, play the sound now. */
03288           TileIndex crossing = TrainApproachingCrossingTile(v);
03289           if (crossing != INVALID_TILE && HasCrossingReservation(crossing) && _settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03290 
03291           /* Always try to extend the reservation when entering a tile. */
03292           CheckNextTrainTile(v);
03293         }
03294 
03295         if (HasBit(r, VETS_ENTERED_STATION)) {
03296           /* The new position is the location where we want to stop */
03297           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03298         }
03299       }
03300     } else {
03301       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03302         /* Perform look-ahead on tunnel exit. */
03303         if (v->IsFrontEngine()) {
03304           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03305           CheckNextTrainTile(v);
03306         }
03307         /* Prevent v->UpdateInclination() being called with wrong parameters.
03308          * This could happen if the train was reversed inside the tunnel/bridge. */
03309         if (gp.old_tile == gp.new_tile) {
03310           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03311         }
03312       } else {
03313         v->x_pos = gp.x;
03314         v->y_pos = gp.y;
03315         VehicleUpdatePosition(v);
03316         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03317         continue;
03318       }
03319     }
03320 
03321     /* update image of train, as well as delta XY */
03322     v->UpdateDeltaXY(v->direction);
03323 
03324     v->x_pos = gp.x;
03325     v->y_pos = gp.y;
03326     VehicleUpdatePosition(v);
03327 
03328     /* update the Z position of the vehicle */
03329     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03330 
03331     if (prev == NULL) {
03332       /* This is the first vehicle in the train */
03333       AffectSpeedByZChange(v, old_z);
03334     }
03335 
03336     if (update_signals_crossing) {
03337       if (v->IsFrontEngine()) {
03338         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03339           /* We are entering a block with PBS signals right now, but
03340            * not through a PBS signal. This means we don't have a
03341            * reservation right now. As a conventional signal will only
03342            * ever be green if no other train is in the block, getting
03343            * a path should always be possible. If the player built
03344            * such a strange network that it is not possible, the train
03345            * will be marked as stuck and the player has to deal with
03346            * the problem. */
03347           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03348               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03349               !TryPathReserve(v)) {
03350             MarkTrainAsStuck(v);
03351           }
03352         }
03353       }
03354 
03355       /* Signals can only change when the first
03356        * (above) or the last vehicle moves. */
03357       if (v->Next() == NULL) {
03358         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03359         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03360       }
03361     }
03362 
03363     /* Do not check on every tick to save some computing time. */
03364     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03365   }
03366 
03367   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03368 
03369   return true;
03370 
03371 invalid_rail:
03372   /* We've reached end of line?? */
03373   if (prev != NULL) error("Disconnecting train");
03374 
03375 reverse_train_direction:
03376   if (reverse) {
03377     v->wait_counter = 0;
03378     v->cur_speed = 0;
03379     v->subspeed = 0;
03380     ReverseTrainDirection(v);
03381   }
03382 
03383   return false;
03384 }
03385 
03392 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03393 {
03394   TrackBits *trackbits = (TrackBits *)data;
03395 
03396   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03397     TrackBits train_tbits = Train::From(v)->track;
03398     if (train_tbits == TRACK_BIT_WORMHOLE) {
03399       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03400       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03401     } else if (train_tbits != TRACK_BIT_DEPOT) {
03402       *trackbits |= train_tbits;
03403     }
03404   }
03405 
03406   return NULL;
03407 }
03408 
03416 static void DeleteLastWagon(Train *v)
03417 {
03418   Train *first = v->First();
03419 
03420   /* Go to the last wagon and delete the link pointing there
03421    * *u is then the one-before-last wagon, and *v the last
03422    * one which will physically be removed */
03423   Train *u = v;
03424   for (; v->Next() != NULL; v = v->Next()) u = v;
03425   u->SetNext(NULL);
03426 
03427   if (first != v) {
03428     /* Recalculate cached train properties */
03429     first->ConsistChanged(false);
03430     /* Update the depot window if the first vehicle is in depot -
03431      * if v == first, then it is updated in PreDestructor() */
03432     if (first->track == TRACK_BIT_DEPOT) {
03433       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03434     }
03435   }
03436 
03437   /* 'v' shouldn't be accessed after it has been deleted */
03438   TrackBits trackbits = v->track;
03439   TileIndex tile = v->tile;
03440   Owner owner = v->owner;
03441 
03442   delete v;
03443   v = NULL; // make sure nobody will try to read 'v' anymore
03444 
03445   if (trackbits == TRACK_BIT_WORMHOLE) {
03446     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03447     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03448   }
03449 
03450   Track track = TrackBitsToTrack(trackbits);
03451   if (HasReservedTracks(tile, trackbits)) {
03452     UnreserveRailTrack(tile, track);
03453 
03454     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03455     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03456     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03457 
03458     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03459     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03460     Track t;
03461     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03462   }
03463 
03464   /* check if the wagon was on a road/rail-crossing */
03465   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03466 
03467   /* Update signals */
03468   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03469     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03470   } else {
03471     SetSignalsOnBothDir(tile, track, owner);
03472   }
03473 }
03474 
03479 static void ChangeTrainDirRandomly(Train *v)
03480 {
03481   static const DirDiff delta[] = {
03482     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03483   };
03484 
03485   do {
03486     /* We don't need to twist around vehicles if they're not visible */
03487     if (!(v->vehstatus & VS_HIDDEN)) {
03488       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03489       v->UpdateDeltaXY(v->direction);
03490       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03491       /* Refrain from updating the z position of the vehicle when on
03492        * a bridge, because UpdateInclination() will put the vehicle under
03493        * the bridge in that case */
03494       if (v->track != TRACK_BIT_WORMHOLE) {
03495         VehicleUpdatePosition(v);
03496         v->UpdateInclination(false, false);
03497       }
03498     }
03499   } while ((v = v->Next()) != NULL);
03500 }
03501 
03507 static bool HandleCrashedTrain(Train *v)
03508 {
03509   int state = ++v->crash_anim_pos;
03510 
03511   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03512     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03513   }
03514 
03515   uint32 r;
03516   if (state <= 200 && Chance16R(1, 7, r)) {
03517     int index = (r * 10 >> 16);
03518 
03519     Vehicle *u = v;
03520     do {
03521       if (--index < 0) {
03522         r = Random();
03523 
03524         CreateEffectVehicleRel(u,
03525           GB(r,  8, 3) + 2,
03526           GB(r, 16, 3) + 2,
03527           GB(r,  0, 3) + 5,
03528           EV_EXPLOSION_SMALL);
03529         break;
03530       }
03531     } while ((u = u->Next()) != NULL);
03532   }
03533 
03534   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03535 
03536   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03537     bool ret = v->Next() != NULL;
03538     DeleteLastWagon(v);
03539     return ret;
03540   }
03541 
03542   return true;
03543 }
03544 
03546 static const uint16 _breakdown_speeds[16] = {
03547   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03548 };
03549 
03550 
03559 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03560 {
03561   /* Calc position within the current tile */
03562   uint x = v->x_pos & 0xF;
03563   uint y = v->y_pos & 0xF;
03564 
03565   /* for diagonal directions, 'x' will be 0..15 -
03566    * for other directions, it will be 1, 3, 5, ..., 15 */
03567   switch (v->direction) {
03568     case DIR_N : x = ~x + ~y + 25; break;
03569     case DIR_NW: x = y;            // FALL THROUGH
03570     case DIR_NE: x = ~x + 16;      break;
03571     case DIR_E : x = ~x + y + 9;   break;
03572     case DIR_SE: x = y;            break;
03573     case DIR_S : x = x + y - 7;    break;
03574     case DIR_W : x = ~y + x + 9;   break;
03575     default: break;
03576   }
03577 
03578   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03579    * does not cross the tile boundary when we do reverse, but as the vehicle's
03580    * location is based on their center, use half a vehicle's length as offset.
03581    * Multiply the half-length by two for straight directions to compensate that
03582    * we only get odd x offsets there. */
03583   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03584     /* we are too near the tile end, reverse now */
03585     v->cur_speed = 0;
03586     if (reverse) ReverseTrainDirection(v);
03587     return false;
03588   }
03589 
03590   /* slow down */
03591   v->vehstatus |= VS_TRAIN_SLOWING;
03592   uint16 break_speed = _breakdown_speeds[x & 0xF];
03593   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03594 
03595   return true;
03596 }
03597 
03598 
03604 static bool TrainCanLeaveTile(const Train *v)
03605 {
03606   /* Exit if inside a tunnel/bridge or a depot */
03607   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03608 
03609   TileIndex tile = v->tile;
03610 
03611   /* entering a tunnel/bridge? */
03612   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03613     DiagDirection dir = GetTunnelBridgeDirection(tile);
03614     if (DiagDirToDir(dir) == v->direction) return false;
03615   }
03616 
03617   /* entering a depot? */
03618   if (IsRailDepotTile(tile)) {
03619     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03620     if (DiagDirToDir(dir) == v->direction) return false;
03621   }
03622 
03623   return true;
03624 }
03625 
03626 
03634 static TileIndex TrainApproachingCrossingTile(const Train *v)
03635 {
03636   assert(v->IsFrontEngine());
03637   assert(!(v->vehstatus & VS_CRASHED));
03638 
03639   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03640 
03641   DiagDirection dir = TrainExitDir(v->direction, v->track);
03642   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03643 
03644   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03645   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03646       !CheckCompatibleRail(v, tile)) {
03647     return INVALID_TILE;
03648   }
03649 
03650   return tile;
03651 }
03652 
03653 
03661 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03662 {
03663   /* First, handle broken down train */
03664 
03665   int t = v->breakdown_ctr;
03666   if (t > 1) {
03667     v->vehstatus |= VS_TRAIN_SLOWING;
03668 
03669     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03670     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03671   } else {
03672     v->vehstatus &= ~VS_TRAIN_SLOWING;
03673   }
03674 
03675   if (!TrainCanLeaveTile(v)) return true;
03676 
03677   /* Determine the non-diagonal direction in which we will exit this tile */
03678   DiagDirection dir = TrainExitDir(v->direction, v->track);
03679   /* Calculate next tile */
03680   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03681 
03682   /* Determine the track status on the next tile */
03683   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03684   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03685 
03686   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03687   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03688 
03689   /* We are sure the train is not entering a depot, it is detected above */
03690 
03691   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03692   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03693   if (_settings_game.pf.forbid_90_deg) {
03694     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03695   }
03696 
03697   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03698   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03699     return TrainApproachingLineEnd(v, false, reverse);
03700   }
03701 
03702   /* approaching red signal */
03703   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03704 
03705   /* approaching a rail/road crossing? then make it red */
03706   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03707 
03708   return true;
03709 }
03710 
03711 
03712 static bool TrainLocoHandler(Train *v, bool mode)
03713 {
03714   /* train has crashed? */
03715   if (v->vehstatus & VS_CRASHED) {
03716     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03717   }
03718 
03719   if (v->force_proceed != TFP_NONE) {
03720     ClrBit(v->flags, VRF_TRAIN_STUCK);
03721     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03722   }
03723 
03724   /* train is broken down? */
03725   if (v->HandleBreakdown()) return true;
03726 
03727   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03728     ReverseTrainDirection(v);
03729   }
03730 
03731   /* exit if train is stopped */
03732   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03733 
03734   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03735   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03736     v->wait_counter = 0;
03737     v->cur_speed = 0;
03738     v->subspeed = 0;
03739     ClrBit(v->flags, VRF_LEAVING_STATION);
03740     ReverseTrainDirection(v);
03741     return true;
03742   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03743     /* Try to reserve a path when leaving the station as we
03744      * might not be marked as wanting a reservation, e.g.
03745      * when an overlength train gets turned around in a station. */
03746     DiagDirection dir = TrainExitDir(v->direction, v->track);
03747     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03748 
03749     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03750       TryPathReserve(v, true, true);
03751     }
03752     ClrBit(v->flags, VRF_LEAVING_STATION);
03753   }
03754 
03755   v->HandleLoading(mode);
03756 
03757   if (v->current_order.IsType(OT_LOADING)) return true;
03758 
03759   if (CheckTrainStayInDepot(v)) return true;
03760 
03761   if (!mode) v->ShowVisualEffect();
03762 
03763   /* We had no order but have an order now, do look ahead. */
03764   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03765     CheckNextTrainTile(v);
03766   }
03767 
03768   /* Handle stuck trains. */
03769   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03770     ++v->wait_counter;
03771 
03772     /* Should we try reversing this tick if still stuck? */
03773     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03774 
03775     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03776     if (!TryPathReserve(v)) {
03777       /* Still stuck. */
03778       if (turn_around) ReverseTrainDirection(v);
03779 
03780       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03781         /* Show message to player. */
03782         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03783           SetDParam(0, v->index);
03784           AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_STUCK, v->index);
03785         }
03786         v->wait_counter = 0;
03787       }
03788       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03789       if (v->force_proceed == TFP_NONE) return true;
03790       ClrBit(v->flags, VRF_TRAIN_STUCK);
03791       v->wait_counter = 0;
03792       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03793     }
03794   }
03795 
03796   if (v->current_order.IsType(OT_LEAVESTATION)) {
03797     v->current_order.Free();
03798     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03799     return true;
03800   }
03801 
03802   int j = v->UpdateSpeed();
03803 
03804   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03805   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03806     /* If we manually stopped, we're not force-proceeding anymore. */
03807     v->force_proceed = TFP_NONE;
03808     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03809   }
03810 
03811   int adv_spd = v->GetAdvanceDistance();
03812   if (j < adv_spd) {
03813     /* if the vehicle has speed 0, update the last_speed field. */
03814     if (v->cur_speed == 0) v->SetLastSpeed();
03815   } else {
03816     TrainCheckIfLineEnds(v);
03817     /* Loop until the train has finished moving. */
03818     for (;;) {
03819       j -= adv_spd;
03820       TrainController(v, NULL);
03821       /* Don't continue to move if the train crashed. */
03822       if (CheckTrainCollision(v)) break;
03823       /* Determine distance to next map position */
03824       adv_spd = v->GetAdvanceDistance();
03825 
03826       /* No more moving this tick */
03827       if (j < adv_spd || v->cur_speed == 0) break;
03828 
03829       OrderType order_type = v->current_order.GetType();
03830       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03831       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03832             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03833             IsTileType(v->tile, MP_STATION) &&
03834             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03835         ProcessOrders(v);
03836       }
03837     }
03838     v->SetLastSpeed();
03839   }
03840 
03841   for (Train *u = v; u != NULL; u = u->Next()) {
03842     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03843 
03844     u->UpdateViewport(false, false);
03845   }
03846 
03847   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03848 
03849   return true;
03850 }
03851 
03856 Money Train::GetRunningCost() const
03857 {
03858   Money cost = 0;
03859   const Train *v = this;
03860 
03861   do {
03862     const Engine *e = v->GetEngine();
03863     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03864 
03865     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03866     if (cost_factor == 0) continue;
03867 
03868     /* Halve running cost for multiheaded parts */
03869     if (v->IsMultiheaded()) cost_factor /= 2;
03870 
03871     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03872   } while ((v = v->GetNextVehicle()) != NULL);
03873 
03874   return cost;
03875 }
03876 
03881 bool Train::Tick()
03882 {
03883   this->tick_counter++;
03884 
03885   if (this->IsFrontEngine()) {
03886     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03887 
03888     this->current_order_time++;
03889 
03890     if (!TrainLocoHandler(this, false)) return false;
03891 
03892     return TrainLocoHandler(this, true);
03893   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03894     /* Delete flooded standalone wagon chain */
03895     if (++this->crash_anim_pos >= 4400) {
03896       delete this;
03897       return false;
03898     }
03899   }
03900 
03901   return true;
03902 }
03903 
03908 static void CheckIfTrainNeedsService(Train *v)
03909 {
03910   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03911   if (v->IsChainInDepot()) {
03912     VehicleServiceInDepot(v);
03913     return;
03914   }
03915 
03916   uint max_penalty;
03917   switch (_settings_game.pf.pathfinder_for_trains) {
03918     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03919     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03920     default: NOT_REACHED();
03921   }
03922 
03923   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03924   /* Only go to the depot if it is not too far out of our way. */
03925   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03926     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03927       /* If we were already heading for a depot but it has
03928        * suddenly moved farther away, we continue our normal
03929        * schedule? */
03930       v->current_order.MakeDummy();
03931       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03932     }
03933     return;
03934   }
03935 
03936   DepotID depot = GetDepotIndex(tfdd.tile);
03937 
03938   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03939       v->current_order.GetDestination() != depot &&
03940       !Chance16(3, 16)) {
03941     return;
03942   }
03943 
03944   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03945   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03946   v->dest_tile = tfdd.tile;
03947   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03948 }
03949 
03951 void Train::OnNewDay()
03952 {
03953   AgeVehicle(this);
03954 
03955   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03956 
03957   if (this->IsFrontEngine()) {
03958     CheckVehicleBreakdown(this);
03959 
03960     CheckIfTrainNeedsService(this);
03961 
03962     CheckOrders(this);
03963 
03964     /* update destination */
03965     if (this->current_order.IsType(OT_GOTO_STATION)) {
03966       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03967       if (tile != INVALID_TILE) this->dest_tile = tile;
03968     }
03969 
03970     if (this->running_ticks != 0) {
03971       /* running costs */
03972       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03973 
03974       this->profit_this_year -= cost.GetCost();
03975       this->running_ticks = 0;
03976 
03977       SubtractMoneyFromCompanyFract(this->owner, cost);
03978 
03979       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03980       SetWindowClassesDirty(WC_TRAINS_LIST);
03981     }
03982   }
03983 }
03984 
03989 Trackdir Train::GetVehicleTrackdir() const
03990 {
03991   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03992 
03993   if (this->track == TRACK_BIT_DEPOT) {
03994     /* We'll assume the train is facing outwards */
03995     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03996   }
03997 
03998   if (this->track == TRACK_BIT_WORMHOLE) {
03999     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
04000     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
04001   }
04002 
04003   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
04004 }