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     u->cargo_cap = e_u->DetermineCapacity(u);
00204     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00205 
00206     /* check the vehicle length (callback) */
00207     uint16 veh_len = CALLBACK_FAILED;
00208     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00209       /* Use callback 36 */
00210       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00211     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00212       /* Use callback 11 */
00213       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00214     }
00215     if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00216       ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00217     }
00218     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00219     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00220 
00221     /* verify length hasn't changed */
00222     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00223 
00224     /* update vehicle length? */
00225     if (!same_length) u->gcache.cached_veh_length = veh_len;
00226 
00227     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00228     this->InvalidateNewGRFCache();
00229     u->InvalidateNewGRFCache();
00230   }
00231 
00232   /* store consist weight/max speed in cache */
00233   this->vcache.cached_max_speed = max_speed;
00234   this->tcache.cached_tilt = train_can_tilt;
00235   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00236 
00237   /* 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) */
00238   this->CargoChanged();
00239 
00240   if (this->IsFrontEngine()) {
00241     this->UpdateAcceleration();
00242     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00243     InvalidateWindowData(WC_VEHICLE_REFIT, this->index);
00244   }
00245 }
00246 
00257 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00258 {
00259   const Station *st = Station::Get(station_id);
00260   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00261   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00262 
00263   /* Default to the middle of the station for stations stops that are not in
00264    * the order list like intermediate stations when non-stop is disabled */
00265   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00266   if (v->gcache.cached_total_length >= *station_length) {
00267     /* The train is longer than the station, make it stop at the far end of the platform */
00268     osl = OSL_PLATFORM_FAR_END;
00269   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00270     osl = v->current_order.GetStopLocation();
00271   }
00272 
00273   /* The stop location of the FRONT! of the train */
00274   int stop;
00275   switch (osl) {
00276     default: NOT_REACHED();
00277 
00278     case OSL_PLATFORM_NEAR_END:
00279       stop = v->gcache.cached_total_length;
00280       break;
00281 
00282     case OSL_PLATFORM_MIDDLE:
00283       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00284       break;
00285 
00286     case OSL_PLATFORM_FAR_END:
00287       stop = *station_length;
00288       break;
00289   }
00290 
00291   /* Subtract half the front vehicle length of the train so we get the real
00292    * stop location of the train. */
00293   return stop - (v->gcache.cached_veh_length + 1) / 2;
00294 }
00295 
00296 
00301 int Train::GetCurveSpeedLimit() const
00302 {
00303   assert(this->First() == this);
00304 
00305   static const int absolute_max_speed = UINT16_MAX;
00306   int max_speed = absolute_max_speed;
00307 
00308   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00309 
00310   int curvecount[2] = {0, 0};
00311 
00312   /* first find the curve speed limit */
00313   int numcurve = 0;
00314   int sum = 0;
00315   int pos = 0;
00316   int lastpos = -1;
00317   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00318     Direction this_dir = u->direction;
00319     Direction next_dir = u->Next()->direction;
00320 
00321     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00322     if (dirdiff == DIRDIFF_SAME) continue;
00323 
00324     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00325     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00326     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00327       if (lastpos != -1) {
00328         numcurve++;
00329         sum += pos - lastpos;
00330         if (pos - lastpos == 1 && max_speed > 88) {
00331           max_speed = 88;
00332         }
00333       }
00334       lastpos = pos;
00335     }
00336 
00337     /* if we have a 90 degree turn, fix the speed limit to 60 */
00338     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00339       max_speed = 61;
00340     }
00341   }
00342 
00343   if (numcurve > 0 && max_speed > 88) {
00344     if (curvecount[0] == 1 && curvecount[1] == 1) {
00345       max_speed = absolute_max_speed;
00346     } else {
00347       sum /= numcurve;
00348       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00349     }
00350   }
00351 
00352   if (max_speed != absolute_max_speed) {
00353     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00354     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00355     max_speed += (max_speed / 2) * rti->curve_speed;
00356 
00357     if (this->tcache.cached_tilt) {
00358       /* Apply max_speed bonus of 20% for a tilting train */
00359       max_speed += max_speed / 5;
00360     }
00361   }
00362 
00363   return max_speed;
00364 }
00365 
00370 int Train::GetCurrentMaxSpeed() const
00371 {
00372   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return min(this->gcache.cached_max_track_speed, this->current_order.max_speed);
00373 
00374   int max_speed = this->tcache.cached_max_curve_speed;
00375   assert(max_speed == this->GetCurveSpeedLimit());
00376 
00377   if (IsRailStationTile(this->tile)) {
00378     StationID sid = GetStationIndex(this->tile);
00379     if (this->current_order.ShouldStopAtStation(this, sid)) {
00380       int station_ahead;
00381       int station_length;
00382       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00383 
00384       /* The distance to go is whatever is still ahead of the train minus the
00385        * distance from the train's stop location to the end of the platform */
00386       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00387 
00388       if (distance_to_go > 0) {
00389         int st_max_speed = 120;
00390 
00391         int delta_v = this->cur_speed / (distance_to_go + 1);
00392         if (max_speed > (this->cur_speed - delta_v)) {
00393           st_max_speed = this->cur_speed - (delta_v / 10);
00394         }
00395 
00396         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00397         max_speed = min(max_speed, st_max_speed);
00398       }
00399     }
00400   }
00401 
00402   for (const Train *u = this; u != NULL; u = u->Next()) {
00403     if (u->track == TRACK_BIT_DEPOT) {
00404       max_speed = min(max_speed, 61);
00405       break;
00406     }
00407   }
00408 
00409   max_speed = min(max_speed, this->current_order.max_speed);
00410   return min(max_speed, this->gcache.cached_max_track_speed);
00411 }
00412 
00414 void Train::UpdateAcceleration()
00415 {
00416   assert(this->IsFrontEngine());
00417 
00418   uint power = this->gcache.cached_power;
00419   uint weight = this->gcache.cached_weight;
00420   assert(weight != 0);
00421   this->acceleration = Clamp(power / weight * 4, 1, 255);
00422 }
00423 
00429 int Train::GetDisplayImageWidth(Point *offset) const
00430 {
00431   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00432   int vehicle_pitch = 0;
00433 
00434   const Engine *e = this->GetEngine();
00435   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00436     reference_width = e->GetGRF()->traininfo_vehicle_width;
00437     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00438   }
00439 
00440   if (offset != NULL) {
00441     offset->x = reference_width / 2;
00442     offset->y = vehicle_pitch;
00443   }
00444   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00445 }
00446 
00447 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00448 {
00449   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00450 }
00451 
00458 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00459 {
00460   uint8 spritenum = this->spritenum;
00461   SpriteID sprite;
00462 
00463   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00464 
00465   if (is_custom_sprite(spritenum)) {
00466     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00467     if (sprite != 0) return sprite;
00468 
00469     spritenum = this->GetEngine()->original_image_index;
00470   }
00471 
00472   sprite = GetDefaultTrainSprite(spritenum, direction);
00473 
00474   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00475 
00476   return sprite;
00477 }
00478 
00479 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00480 {
00481   const Engine *e = Engine::Get(engine);
00482   Direction dir = rear_head ? DIR_E : DIR_W;
00483   uint8 spritenum = e->u.rail.image_index;
00484 
00485   if (is_custom_sprite(spritenum)) {
00486     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00487     if (sprite != 0) {
00488       if (e->GetGRF() != NULL) {
00489         y += e->GetGRF()->traininfo_vehicle_pitch;
00490       }
00491       return sprite;
00492     }
00493 
00494     spritenum = Engine::Get(engine)->original_image_index;
00495   }
00496 
00497   if (rear_head) spritenum++;
00498 
00499   return GetDefaultTrainSprite(spritenum, DIR_W);
00500 }
00501 
00502 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00503 {
00504   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00505     int yf = y;
00506     int yr = y;
00507 
00508     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00509     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00510     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00511     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00512 
00513     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);
00514 
00515     DrawSprite(spritef, pal, preferred_x - 14, yf);
00516     DrawSprite(spriter, pal, preferred_x + 15, yr);
00517   } else {
00518     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00519     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00520     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));
00521     DrawSprite(sprite, pal, preferred_x, y);
00522   }
00523 }
00524 
00533 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00534 {
00535   const RailVehicleInfo *rvi = &e->u.rail;
00536 
00537   /* Check that the wagon can drive on the track in question */
00538   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00539 
00540   if (flags & DC_EXEC) {
00541     Train *v = new Train();
00542     *ret = v;
00543     v->spritenum = rvi->image_index;
00544 
00545     v->engine_type = e->index;
00546     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00547 
00548     DiagDirection dir = GetRailDepotDirection(tile);
00549 
00550     v->direction = DiagDirToDir(dir);
00551     v->tile = tile;
00552 
00553     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00554     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00555 
00556     v->x_pos = x;
00557     v->y_pos = y;
00558     v->z_pos = GetSlopePixelZ(x, y);
00559     v->owner = _current_company;
00560     v->track = TRACK_BIT_DEPOT;
00561     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00562 
00563     v->SetWagon();
00564 
00565     v->SetFreeWagon();
00566     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00567 
00568     v->cargo_type = e->GetDefaultCargoType();
00569     v->cargo_cap = rvi->capacity;
00570 
00571     v->railtype = rvi->railtype;
00572 
00573     v->build_year = _cur_year;
00574     v->cur_image = SPR_IMG_QUERY;
00575     v->random_bits = VehicleRandomBits();
00576 
00577     v->group_id = DEFAULT_GROUP;
00578 
00579     AddArticulatedParts(v);
00580 
00581     _new_vehicle_id = v->index;
00582 
00583     VehicleUpdatePosition(v);
00584     v->First()->ConsistChanged(false);
00585     UpdateTrainGroupID(v->First());
00586 
00587     CheckConsistencyOfArticulatedVehicle(v);
00588 
00589     /* Try to connect the vehicle to one of free chains of wagons. */
00590     Train *w;
00591     FOR_ALL_TRAINS(w) {
00592       if (w->tile == tile &&              
00593           w->IsFreeWagon() &&             
00594           w->engine_type == e->index &&   
00595           w->First() != v &&              
00596           !(w->vehstatus & VS_CRASHED)) { 
00597         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00598         break;
00599       }
00600     }
00601   }
00602 
00603   return CommandCost();
00604 }
00605 
00607 static void NormalizeTrainVehInDepot(const Train *u)
00608 {
00609   const Train *v;
00610   FOR_ALL_TRAINS(v) {
00611     if (v->IsFreeWagon() && v->tile == u->tile &&
00612         v->track == TRACK_BIT_DEPOT) {
00613       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00614           CMD_MOVE_RAIL_VEHICLE).Failed())
00615         break;
00616     }
00617   }
00618 }
00619 
00620 static void AddRearEngineToMultiheadedTrain(Train *v)
00621 {
00622   Train *u = new Train();
00623   v->value >>= 1;
00624   u->value = v->value;
00625   u->direction = v->direction;
00626   u->owner = v->owner;
00627   u->tile = v->tile;
00628   u->x_pos = v->x_pos;
00629   u->y_pos = v->y_pos;
00630   u->z_pos = v->z_pos;
00631   u->track = TRACK_BIT_DEPOT;
00632   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00633   u->spritenum = v->spritenum + 1;
00634   u->cargo_type = v->cargo_type;
00635   u->cargo_subtype = v->cargo_subtype;
00636   u->cargo_cap = v->cargo_cap;
00637   u->railtype = v->railtype;
00638   u->engine_type = v->engine_type;
00639   u->build_year = v->build_year;
00640   u->cur_image = SPR_IMG_QUERY;
00641   u->random_bits = VehicleRandomBits();
00642   v->SetMultiheaded();
00643   u->SetMultiheaded();
00644   v->SetNext(u);
00645   VehicleUpdatePosition(u);
00646 
00647   /* Now we need to link the front and rear engines together */
00648   v->other_multiheaded_part = u;
00649   u->other_multiheaded_part = v;
00650 }
00651 
00661 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00662 {
00663   const RailVehicleInfo *rvi = &e->u.rail;
00664 
00665   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00666 
00667   /* Check if depot and new engine uses the same kind of tracks *
00668    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00669   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00670 
00671   if (flags & DC_EXEC) {
00672     DiagDirection dir = GetRailDepotDirection(tile);
00673     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00674     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00675 
00676     Train *v = new Train();
00677     *ret = v;
00678     v->direction = DiagDirToDir(dir);
00679     v->tile = tile;
00680     v->owner = _current_company;
00681     v->x_pos = x;
00682     v->y_pos = y;
00683     v->z_pos = GetSlopePixelZ(x, y);
00684     v->track = TRACK_BIT_DEPOT;
00685     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00686     v->spritenum = rvi->image_index;
00687     v->cargo_type = e->GetDefaultCargoType();
00688     v->cargo_cap = rvi->capacity;
00689     v->last_station_visited = INVALID_STATION;
00690 
00691     v->engine_type = e->index;
00692     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00693 
00694     v->reliability = e->reliability;
00695     v->reliability_spd_dec = e->reliability_spd_dec;
00696     v->max_age = e->GetLifeLengthInDays();
00697 
00698     v->railtype = rvi->railtype;
00699     _new_vehicle_id = v->index;
00700 
00701     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00702     v->date_of_last_service = _date;
00703     v->build_year = _cur_year;
00704     v->cur_image = SPR_IMG_QUERY;
00705     v->random_bits = VehicleRandomBits();
00706 
00707     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00708 
00709     v->group_id = DEFAULT_GROUP;
00710 
00711     v->SetFrontEngine();
00712     v->SetEngine();
00713 
00714     VehicleUpdatePosition(v);
00715 
00716     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00717       AddRearEngineToMultiheadedTrain(v);
00718     } else {
00719       AddArticulatedParts(v);
00720     }
00721 
00722     v->ConsistChanged(false);
00723     UpdateTrainGroupID(v);
00724 
00725     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00726       NormalizeTrainVehInDepot(v);
00727     }
00728 
00729     CheckConsistencyOfArticulatedVehicle(v);
00730   }
00731 
00732   return CommandCost();
00733 }
00734 
00735 static Train *FindGoodVehiclePos(const Train *src)
00736 {
00737   EngineID eng = src->engine_type;
00738   TileIndex tile = src->tile;
00739 
00740   Train *dst;
00741   FOR_ALL_TRAINS(dst) {
00742     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00743       /* check so all vehicles in the line have the same engine. */
00744       Train *t = dst;
00745       while (t->engine_type == eng) {
00746         t = t->Next();
00747         if (t == NULL) return dst;
00748       }
00749     }
00750   }
00751 
00752   return NULL;
00753 }
00754 
00756 typedef SmallVector<Train *, 16> TrainList;
00757 
00763 static void MakeTrainBackup(TrainList &list, Train *t)
00764 {
00765   for (; t != NULL; t = t->Next()) *list.Append() = t;
00766 }
00767 
00772 static void RestoreTrainBackup(TrainList &list)
00773 {
00774   /* No train, nothing to do. */
00775   if (list.Length() == 0) return;
00776 
00777   Train *prev = NULL;
00778   /* Iterate over the list and rebuild it. */
00779   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00780     Train *t = *iter;
00781     if (prev != NULL) {
00782       prev->SetNext(t);
00783     } else if (t->Previous() != NULL) {
00784       /* Make sure the head of the train is always the first in the chain. */
00785       t->Previous()->SetNext(NULL);
00786     }
00787     prev = t;
00788   }
00789 }
00790 
00796 static void RemoveFromConsist(Train *part, bool chain = false)
00797 {
00798   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00799 
00800   /* Unlink at the front, but make it point to the next
00801    * vehicle after the to be remove part. */
00802   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00803 
00804   /* Unlink at the back */
00805   tail->SetNext(NULL);
00806 }
00807 
00813 static void InsertInConsist(Train *dst, Train *chain)
00814 {
00815   /* We do not want to add something in the middle of an articulated part. */
00816   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00817 
00818   chain->Last()->SetNext(dst->Next());
00819   dst->SetNext(chain);
00820 }
00821 
00827 static void NormaliseDualHeads(Train *t)
00828 {
00829   for (; t != NULL; t = t->GetNextVehicle()) {
00830     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00831 
00832     /* Make sure that there are no free cars before next engine */
00833     Train *u;
00834     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00835 
00836     if (u == t->other_multiheaded_part) continue;
00837 
00838     /* Remove the part from the 'wrong' train */
00839     RemoveFromConsist(t->other_multiheaded_part);
00840     /* And add it to the 'right' train */
00841     InsertInConsist(u, t->other_multiheaded_part);
00842   }
00843 }
00844 
00849 static void NormaliseSubtypes(Train *chain)
00850 {
00851   /* Nothing to do */
00852   if (chain == NULL) return;
00853 
00854   /* We must be the first in the chain. */
00855   assert(chain->Previous() == NULL);
00856 
00857   /* Set the appropriate bits for the first in the chain. */
00858   if (chain->IsWagon()) {
00859     chain->SetFreeWagon();
00860   } else {
00861     assert(chain->IsEngine());
00862     chain->SetFrontEngine();
00863   }
00864 
00865   /* Now clear the bits for the rest of the chain */
00866   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00867     t->ClearFreeWagon();
00868     t->ClearFrontEngine();
00869   }
00870 }
00871 
00881 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00882 {
00883   /* Just add 'new' engines and subtract the original ones.
00884    * If that's less than or equal to 0 we can be sure we did
00885    * not add any engines (read: trains) along the way. */
00886   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00887       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00888       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00889       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00890     return CommandCost();
00891   }
00892 
00893   /* Get a free unit number and check whether it's within the bounds.
00894    * There will always be a maximum of one new train. */
00895   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00896 
00897   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00898 }
00899 
00905 static CommandCost CheckTrainAttachment(Train *t)
00906 {
00907   /* No multi-part train, no need to check. */
00908   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00909 
00910   /* The maximum length for a train. For each part we decrease this by one
00911    * and if the result is negative the train is simply too long. */
00912   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00913 
00914   Train *head = t;
00915   Train *prev = t;
00916 
00917   /* Break the prev -> t link so it always holds within the loop. */
00918   t = t->Next();
00919   prev->SetNext(NULL);
00920 
00921   /* Make sure the cache is cleared. */
00922   head->InvalidateNewGRFCache();
00923 
00924   while (t != NULL) {
00925     allowed_len -= t->gcache.cached_veh_length;
00926 
00927     Train *next = t->Next();
00928 
00929     /* Unlink the to-be-added piece; it is already unlinked from the previous
00930      * part due to the fact that the prev -> t link is broken. */
00931     t->SetNext(NULL);
00932 
00933     /* Don't check callback for articulated or rear dual headed parts */
00934     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00935       /* Back up and clear the first_engine data to avoid using wagon override group */
00936       EngineID first_engine = t->gcache.first_engine;
00937       t->gcache.first_engine = INVALID_ENGINE;
00938 
00939       /* We don't want the cache to interfere. head's cache is cleared before
00940        * the loop and after each callback does not need to be cleared here. */
00941       t->InvalidateNewGRFCache();
00942 
00943       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00944 
00945       /* Restore original first_engine data */
00946       t->gcache.first_engine = first_engine;
00947 
00948       /* We do not want to remember any cached variables from the test run */
00949       t->InvalidateNewGRFCache();
00950       head->InvalidateNewGRFCache();
00951 
00952       if (callback != CALLBACK_FAILED) {
00953         /* A failing callback means everything is okay */
00954         StringID error = STR_NULL;
00955 
00956         if (head->GetGRF()->grf_version < 8) {
00957           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00958           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00959           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00960         } else {
00961           if (callback < 0x400) {
00962             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00963           } else {
00964             switch (callback) {
00965               case 0x400: // allow if railtypes match (always the case for OpenTTD)
00966               case 0x401: // allow
00967                 break;
00968 
00969               default:    // unknown reason -> disallow
00970               case 0x402: // disallow attaching
00971                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00972                 break;
00973             }
00974           }
00975         }
00976 
00977         if (error != STR_NULL) return_cmd_error(error);
00978       }
00979     }
00980 
00981     /* And link it to the new part. */
00982     prev->SetNext(t);
00983     prev = t;
00984     t = next;
00985   }
00986 
00987   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
00988   return CommandCost();
00989 }
00990 
01001 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01002 {
01003   /* Check whether we may actually construct the trains. */
01004   CommandCost ret = CheckTrainAttachment(src);
01005   if (ret.Failed()) return ret;
01006   ret = CheckTrainAttachment(dst);
01007   if (ret.Failed()) return ret;
01008 
01009   /* Check whether we need to build a new train. */
01010   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01011 }
01012 
01021 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01022 {
01023   /* First determine the front of the two resulting trains */
01024   if (*src_head == *dst_head) {
01025     /* If we aren't moving part(s) to a new train, we are just moving the
01026      * front back and there is not destination head. */
01027     *dst_head = NULL;
01028   } else if (*dst_head == NULL) {
01029     /* If we are moving to a new train the head of the move train would become
01030      * the head of the new vehicle. */
01031     *dst_head = src;
01032   }
01033 
01034   if (src == *src_head) {
01035     /* If we are moving the front of a train then we are, in effect, creating
01036      * a new head for the train. Point to that. Unless we are moving the whole
01037      * train in which case there is not 'source' train anymore.
01038      * In case we are a multiheaded part we want the complete thing to come
01039      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01040      * that is followed by a rear multihead we do not want to include that. */
01041     *src_head = move_chain ? NULL :
01042         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01043   }
01044 
01045   /* Now it's just simply removing the part that we are going to move from the
01046    * source train and *if* the destination is a not a new train add the chain
01047    * at the destination location. */
01048   RemoveFromConsist(src, move_chain);
01049   if (*dst_head != src) InsertInConsist(dst, src);
01050 
01051   /* Now normalise the dual heads, that is move the dual heads around in such
01052    * a way that the head and rear of a dual head are in the same train */
01053   NormaliseDualHeads(*src_head);
01054   NormaliseDualHeads(*dst_head);
01055 }
01056 
01062 static void NormaliseTrainHead(Train *head)
01063 {
01064   /* Not much to do! */
01065   if (head == NULL) return;
01066 
01067   /* Tell the 'world' the train changed. */
01068   head->ConsistChanged(false);
01069   UpdateTrainGroupID(head);
01070 
01071   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01072   if (!head->IsFrontEngine()) return;
01073 
01074   /* Update the refit button and window */
01075   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01076   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01077 
01078   /* If we don't have a unit number yet, set one. */
01079   if (head->unitnumber != 0) return;
01080   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01081 }
01082 
01095 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01096 {
01097   VehicleID s = GB(p1, 0, 20);
01098   VehicleID d = GB(p2, 0, 20);
01099   bool move_chain = HasBit(p1, 20);
01100 
01101   Train *src = Train::GetIfValid(s);
01102   if (src == NULL) return CMD_ERROR;
01103 
01104   CommandCost ret = CheckOwnership(src->owner);
01105   if (ret.Failed()) return ret;
01106 
01107   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01108   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01109 
01110   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01111   Train *dst;
01112   if (d == INVALID_VEHICLE) {
01113     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01114   } else {
01115     dst = Train::GetIfValid(d);
01116     if (dst == NULL) return CMD_ERROR;
01117 
01118     CommandCost ret = CheckOwnership(dst->owner);
01119     if (ret.Failed()) return ret;
01120 
01121     /* Do not allow appending to crashed vehicles, too */
01122     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01123   }
01124 
01125   /* if an articulated part is being handled, deal with its parent vehicle */
01126   src = src->GetFirstEnginePart();
01127   if (dst != NULL) {
01128     dst = dst->GetFirstEnginePart();
01129   }
01130 
01131   /* don't move the same vehicle.. */
01132   if (src == dst) return CommandCost();
01133 
01134   /* locate the head of the two chains */
01135   Train *src_head = src->First();
01136   Train *dst_head;
01137   if (dst != NULL) {
01138     dst_head = dst->First();
01139     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01140     /* Now deal with articulated part of destination wagon */
01141     dst = dst->GetLastEnginePart();
01142   } else {
01143     dst_head = NULL;
01144   }
01145 
01146   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01147 
01148   /* When moving all wagons, we can't have the same src_head and dst_head */
01149   if (move_chain && src_head == dst_head) return CommandCost();
01150 
01151   /* When moving a multiheaded part to be place after itself, bail out. */
01152   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01153 
01154   /* Check if all vehicles in the source train are stopped inside a depot. */
01155   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01156 
01157   /* Check if all vehicles in the destination train are stopped inside a depot. */
01158   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01159 
01160   /* First make a backup of the order of the trains. That way we can do
01161    * whatever we want with the order and later on easily revert. */
01162   TrainList original_src;
01163   TrainList original_dst;
01164 
01165   MakeTrainBackup(original_src, src_head);
01166   MakeTrainBackup(original_dst, dst_head);
01167 
01168   /* Also make backup of the original heads as ArrangeTrains can change them.
01169    * For the destination head we do not care if it is the same as the source
01170    * head because in that case it's just a copy. */
01171   Train *original_src_head = src_head;
01172   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01173 
01174   /* We want this information from before the rearrangement, but execute this after the validation. */
01175   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01176   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01177 
01178   /* (Re)arrange the trains in the wanted arrangement. */
01179   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01180 
01181   if ((flags & DC_AUTOREPLACE) == 0) {
01182     /* If the autoreplace flag is set we do not need to test for the validity
01183      * because we are going to revert the train to its original state. As we
01184      * assume the original state was correct autoreplace can skip this. */
01185     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01186     if (ret.Failed()) {
01187       /* Restore the train we had. */
01188       RestoreTrainBackup(original_src);
01189       RestoreTrainBackup(original_dst);
01190       return ret;
01191     }
01192   }
01193 
01194   /* do it? */
01195   if (flags & DC_EXEC) {
01196     /* Remove old heads from the statistics */
01197     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01198     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01199 
01200     /* First normalise the sub types of the chains. */
01201     NormaliseSubtypes(src_head);
01202     NormaliseSubtypes(dst_head);
01203 
01204     /* There are 14 different cases:
01205      *  1) front engine gets moved to a new train, it stays a front engine.
01206      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01207      *     b) the 'next' part is an engine that becomes a front engine.
01208      *     c) there is no 'next' part, nothing else happens
01209      *  2) front engine gets moved to another train, it is not a front engine anymore
01210      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01211      *     b) the 'next' part is an engine that becomes a front engine.
01212      *     c) there is no 'next' part, nothing else happens
01213      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01214      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01215      *     b) the 'next' part is an engine that becomes a front engine.
01216      *  4) free wagon gets moved
01217      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01218      *     b) the 'next' part is an engine that becomes a front engine.
01219      *     c) there is no 'next' part, nothing else happens
01220      *  5) non front engine gets moved and becomes a new train, nothing else happens
01221      *  6) non front engine gets moved within a train / to another train, nothing hapens
01222      *  7) wagon gets moved, nothing happens
01223      */
01224     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01225       /* Cases #2 and #3: the front engine gets trashed. */
01226       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01227       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01228       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01229       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01230       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01231       SetWindowDirty(WC_COMPANY, _current_company);
01232 
01233       /* Delete orders, group stuff and the unit number as we're not the
01234        * front of any vehicle anymore. */
01235       DeleteVehicleOrders(src);
01236       RemoveVehicleFromGroup(src);
01237       src->unitnumber = 0;
01238     }
01239 
01240     /* We weren't a front engine but are becoming one. So
01241      * we should be put in the default group. */
01242     if (original_src_head != src && dst_head == src) {
01243       SetTrainGroupID(src, DEFAULT_GROUP);
01244       SetWindowDirty(WC_COMPANY, _current_company);
01245     }
01246 
01247     /* Add new heads to statistics */
01248     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01249     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01250 
01251     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01252     NormaliseTrainHead(src_head);
01253     NormaliseTrainHead(dst_head);
01254 
01255     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01256       CheckCargoCapacity(src_head);
01257       CheckCargoCapacity(dst_head);
01258     }
01259 
01260     /* We are undoubtedly changing something in the depot and train list. */
01261     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01262     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01263   } else {
01264     /* We don't want to execute what we're just tried. */
01265     RestoreTrainBackup(original_src);
01266     RestoreTrainBackup(original_dst);
01267   }
01268 
01269   return CommandCost();
01270 }
01271 
01283 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01284 {
01285   /* Check if we deleted a vehicle window */
01286   Window *w = NULL;
01287 
01288   /* Sell a chain of vehicles or not? */
01289   bool sell_chain = HasBit(data, 0);
01290 
01291   Train *v = Train::From(t)->GetFirstEnginePart();
01292   Train *first = v->First();
01293 
01294   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01295 
01296   /* First make a backup of the order of the train. That way we can do
01297    * whatever we want with the order and later on easily revert. */
01298   TrainList original;
01299   MakeTrainBackup(original, first);
01300 
01301   /* We need to keep track of the new head and the head of what we're going to sell. */
01302   Train *new_head = first;
01303   Train *sell_head = NULL;
01304 
01305   /* Split the train in the wanted way. */
01306   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01307 
01308   /* We don't need to validate the second train; it's going to be sold. */
01309   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01310   if (ret.Failed()) {
01311     /* Restore the train we had. */
01312     RestoreTrainBackup(original);
01313     return ret;
01314   }
01315 
01316   CommandCost cost(EXPENSES_NEW_VEHICLES);
01317   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01318 
01319   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01320     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01321   }
01322 
01323   /* do it? */
01324   if (flags & DC_EXEC) {
01325     /* First normalise the sub types of the chain. */
01326     NormaliseSubtypes(new_head);
01327 
01328     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01329       /* We are selling the front engine. In this case we want to
01330        * 'give' the order, unit number and such to the new head. */
01331       new_head->orders.list = first->orders.list;
01332       new_head->AddToShared(first);
01333       DeleteVehicleOrders(first);
01334 
01335       /* Copy other important data from the front engine */
01336       new_head->CopyVehicleConfigAndStatistics(first);
01337       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01338 
01339       /* If we deleted a window then open a new one for the 'new' train */
01340       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01341     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01342       OrderBackup::Backup(v, user);
01343     }
01344 
01345     /* We need to update the information about the train. */
01346     NormaliseTrainHead(new_head);
01347 
01348     /* We are undoubtedly changing something in the depot and train list. */
01349     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01350     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01351 
01352     /* Actually delete the sold 'goods' */
01353     delete sell_head;
01354   } else {
01355     /* We don't want to execute what we're just tried. */
01356     RestoreTrainBackup(original);
01357   }
01358 
01359   return cost;
01360 }
01361 
01362 void Train::UpdateDeltaXY(Direction direction)
01363 {
01364   /* Set common defaults. */
01365   this->x_offs    = -1;
01366   this->y_offs    = -1;
01367   this->x_extent  =  3;
01368   this->y_extent  =  3;
01369   this->z_extent  =  6;
01370   this->x_bb_offs =  0;
01371   this->y_bb_offs =  0;
01372 
01373   if (!IsDiagonalDirection(direction)) {
01374     static const int _sign_table[] =
01375     {
01376       // x, y
01377       -1, -1, // DIR_N
01378       -1,  1, // DIR_E
01379        1,  1, // DIR_S
01380        1, -1, // DIR_W
01381     };
01382 
01383     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01384 
01385     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01386     this->x_offs -= half_shorten * _sign_table[direction];
01387     this->y_offs -= half_shorten * _sign_table[direction + 1];
01388     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01389     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01390   } else {
01391     switch (direction) {
01392         /* Shorten southern corner of the bounding box according the vehicle length
01393          * and center the bounding box on the vehicle. */
01394       case DIR_NE:
01395         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01396         this->x_extent  = this->gcache.cached_veh_length - 1;
01397         this->x_bb_offs = -1;
01398         break;
01399 
01400       case DIR_NW:
01401         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01402         this->y_extent  = this->gcache.cached_veh_length - 1;
01403         this->y_bb_offs = -1;
01404         break;
01405 
01406         /* Move northern corner of the bounding box down according to vehicle length
01407          * and center the bounding box on the vehicle. */
01408       case DIR_SW:
01409         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01410         this->x_extent  = VEHICLE_LENGTH - 1;
01411         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01412         break;
01413 
01414       case DIR_SE:
01415         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01416         this->y_extent  = VEHICLE_LENGTH - 1;
01417         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01418         break;
01419 
01420       default:
01421         NOT_REACHED();
01422     }
01423   }
01424 }
01425 
01430 static void MarkTrainAsStuck(Train *v)
01431 {
01432   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01433     /* It is the first time the problem occurred, set the "train stuck" flag. */
01434     SetBit(v->flags, VRF_TRAIN_STUCK);
01435 
01436     v->wait_counter = 0;
01437 
01438     /* Stop train */
01439     v->cur_speed = 0;
01440     v->subspeed = 0;
01441     v->SetLastSpeed();
01442 
01443     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01444   }
01445 }
01446 
01454 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01455 {
01456   uint16 flag1 = *swap_flag1;
01457   uint16 flag2 = *swap_flag2;
01458 
01459   /* Clear the flags */
01460   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01461   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01462   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01463   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01464 
01465   /* Reverse the rail-flags (if needed) */
01466   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01467     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01468   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01469     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01470   }
01471   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01472     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01473   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01474     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01475   }
01476 }
01477 
01482 static void UpdateStatusAfterSwap(Train *v)
01483 {
01484   /* Reverse the direction. */
01485   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01486 
01487   /* Call the proper EnterTile function unless we are in a wormhole. */
01488   if (v->track != TRACK_BIT_WORMHOLE) {
01489     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01490   } else {
01491     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01492      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01493      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01494      * when we shouldn't have. Check if this is the case. */
01495     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01496     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01497       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01498       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01499         /* We have just left the wormhole, possibly set the
01500          * "goingdown" bit. UpdateInclination() can be used
01501          * because we are at the border of the tile. */
01502         VehicleUpdatePosition(v);
01503         v->UpdateInclination(true, true);
01504         return;
01505       }
01506     }
01507   }
01508 
01509   VehicleUpdatePosition(v);
01510   v->UpdateViewport(true, true);
01511 }
01512 
01519 void ReverseTrainSwapVeh(Train *v, int l, int r)
01520 {
01521   Train *a, *b;
01522 
01523   /* locate vehicles to swap */
01524   for (a = v; l != 0; l--) a = a->Next();
01525   for (b = v; r != 0; r--) b = b->Next();
01526 
01527   if (a != b) {
01528     /* swap the hidden bits */
01529     {
01530       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01531       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01532       a->vehstatus = tmp;
01533     }
01534 
01535     Swap(a->track, b->track);
01536     Swap(a->direction, b->direction);
01537     Swap(a->x_pos, b->x_pos);
01538     Swap(a->y_pos, b->y_pos);
01539     Swap(a->tile,  b->tile);
01540     Swap(a->z_pos, b->z_pos);
01541 
01542     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01543 
01544     UpdateStatusAfterSwap(a);
01545     UpdateStatusAfterSwap(b);
01546   } else {
01547     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01548      * This is a little bit redundant way, a->gv_flags will
01549      * be (re)set twice, but it reduces code duplication */
01550     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01551     UpdateStatusAfterSwap(a);
01552   }
01553 }
01554 
01555 
01561 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01562 {
01563   return (v->type == VEH_TRAIN) ? v : NULL;
01564 }
01565 
01566 
01573 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01574 {
01575   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01576 
01577   Train *t = Train::From(v);
01578   if (!t->IsFrontEngine()) return NULL;
01579 
01580   TileIndex tile = *(TileIndex *)data;
01581 
01582   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01583 
01584   return t;
01585 }
01586 
01587 
01594 static bool TrainApproachingCrossing(TileIndex tile)
01595 {
01596   assert(IsLevelCrossingTile(tile));
01597 
01598   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01599   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01600 
01601   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01602 
01603   dir = ReverseDiagDir(dir);
01604   tile_from = tile + TileOffsByDiagDir(dir);
01605 
01606   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01607 }
01608 
01609 
01616 void UpdateLevelCrossing(TileIndex tile, bool sound)
01617 {
01618   assert(IsLevelCrossingTile(tile));
01619 
01620   /* train on crossing || train approaching crossing || reserved */
01621   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01622 
01623   if (new_state != IsCrossingBarred(tile)) {
01624     if (new_state && sound) {
01625       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01626     }
01627     SetCrossingBarred(tile, new_state);
01628     MarkTileDirtyByTile(tile);
01629   }
01630 }
01631 
01632 
01638 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01639 {
01640   if (!IsCrossingBarred(tile)) {
01641     BarCrossing(tile);
01642     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01643     MarkTileDirtyByTile(tile);
01644   }
01645 }
01646 
01647 
01653 static void AdvanceWagonsBeforeSwap(Train *v)
01654 {
01655   Train *base = v;
01656   Train *first = base; // first vehicle to move
01657   Train *last = v->Last(); // last vehicle to move
01658   uint length = CountVehiclesInChain(v);
01659 
01660   while (length > 2) {
01661     last = last->Previous();
01662     first = first->Next();
01663 
01664     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01665 
01666     /* do not update images now
01667      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01668     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01669 
01670     base = first; // == base->Next()
01671     length -= 2;
01672   }
01673 }
01674 
01675 
01681 static void AdvanceWagonsAfterSwap(Train *v)
01682 {
01683   /* first of all, fix the situation when the train was entering a depot */
01684   Train *dep = v; // last vehicle in front of just left depot
01685   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01686     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01687   }
01688 
01689   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01690 
01691   if (leave != NULL) {
01692     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01693     int d = TicksToLeaveDepot(dep);
01694 
01695     if (d <= 0) {
01696       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01697       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01698       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01699     }
01700   } else {
01701     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01702   }
01703 
01704   Train *base = v;
01705   Train *first = base; // first vehicle to move
01706   Train *last = v->Last(); // last vehicle to move
01707   uint length = CountVehiclesInChain(v);
01708 
01709   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01710    * they have already correct spacing, so we have to make sure they are moved how they should */
01711   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01712 
01713   while (length > 2) {
01714     /* we reached vehicle (originally) in front of a depot, stop now
01715      * (we would move wagons that are already moved with new wagon length). */
01716     if (base == dep) break;
01717 
01718     /* the last wagon was that one leaving a depot, so do not move it anymore */
01719     if (last == dep) nomove = true;
01720 
01721     last = last->Previous();
01722     first = first->Next();
01723 
01724     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01725 
01726     /* do not update images now */
01727     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01728 
01729     base = first; // == base->Next()
01730     length -= 2;
01731   }
01732 }
01733 
01738 void ReverseTrainDirection(Train *v)
01739 {
01740   if (IsRailDepotTile(v->tile)) {
01741     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01742   }
01743 
01744   /* Clear path reservation in front if train is not stuck. */
01745   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01746 
01747   /* Check if we were approaching a rail/road-crossing */
01748   TileIndex crossing = TrainApproachingCrossingTile(v);
01749 
01750   /* count number of vehicles */
01751   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01752 
01753   AdvanceWagonsBeforeSwap(v);
01754 
01755   /* swap start<>end, start+1<>end-1, ... */
01756   int l = 0;
01757   do {
01758     ReverseTrainSwapVeh(v, l++, r--);
01759   } while (l <= r);
01760 
01761   AdvanceWagonsAfterSwap(v);
01762 
01763   if (IsRailDepotTile(v->tile)) {
01764     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01765   }
01766 
01767   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01768 
01769   ClrBit(v->flags, VRF_REVERSING);
01770 
01771   /* recalculate cached data */
01772   v->ConsistChanged(true);
01773 
01774   /* update all images */
01775   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01776 
01777   /* update crossing we were approaching */
01778   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01779 
01780   /* maybe we are approaching crossing now, after reversal */
01781   crossing = TrainApproachingCrossingTile(v);
01782   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01783 
01784   /* If we are inside a depot after reversing, don't bother with path reserving. */
01785   if (v->track == TRACK_BIT_DEPOT) {
01786     /* Can't be stuck here as inside a depot is always a safe tile. */
01787     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01788     ClrBit(v->flags, VRF_TRAIN_STUCK);
01789     return;
01790   }
01791 
01792   /* TrainExitDir does not always produce the desired dir for depots and
01793    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01794   DiagDirection dir = TrainExitDir(v->direction, v->track);
01795   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01796 
01797   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01798     /* If we are currently on a tile with conventional signals, we can't treat the
01799      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01800     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01801       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01802       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01803 
01804     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01805     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01806 
01807     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01808     if (TryPathReserve(v, false, first_tile_okay)) {
01809       /* Do a look-ahead now in case our current tile was already a safe tile. */
01810       CheckNextTrainTile(v);
01811     } else if (v->current_order.GetType() != OT_LOADING) {
01812       /* Do not wait for a way out when we're still loading */
01813       MarkTrainAsStuck(v);
01814     }
01815   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01816     /* A train not inside a PBS block can't be stuck. */
01817     ClrBit(v->flags, VRF_TRAIN_STUCK);
01818     v->wait_counter = 0;
01819   }
01820 }
01821 
01831 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01832 {
01833   Train *v = Train::GetIfValid(p1);
01834   if (v == NULL) return CMD_ERROR;
01835 
01836   CommandCost ret = CheckOwnership(v->owner);
01837   if (ret.Failed()) return ret;
01838 
01839   if (p2 != 0) {
01840     /* turn a single unit around */
01841 
01842     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01843       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01844     }
01845     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01846 
01847     Train *front = v->First();
01848     /* make sure the vehicle is stopped in the depot */
01849     if (!front->IsStoppedInDepot()) {
01850       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01851     }
01852 
01853     if (flags & DC_EXEC) {
01854       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01855 
01856       front->ConsistChanged(false);
01857       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01858       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01859       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01860       SetWindowClassesDirty(WC_TRAINS_LIST);
01861     }
01862   } else {
01863     /* turn the whole train around */
01864     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01865 
01866     if (flags & DC_EXEC) {
01867       /* Properly leave the station if we are loading and won't be loading anymore */
01868       if (v->current_order.IsType(OT_LOADING)) {
01869         const Vehicle *last = v;
01870         while (last->Next() != NULL) last = last->Next();
01871 
01872         /* not a station || different station --> leave the station */
01873         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01874           v->LeaveStation();
01875         }
01876       }
01877 
01878       /* We cancel any 'skip signal at dangers' here */
01879       v->force_proceed = TFP_NONE;
01880       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01881 
01882       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01883         ToggleBit(v->flags, VRF_REVERSING);
01884       } else {
01885         v->cur_speed = 0;
01886         v->SetLastSpeed();
01887         HideFillingPercent(&v->fill_percent_te_id);
01888         ReverseTrainDirection(v);
01889       }
01890     }
01891   }
01892   return CommandCost();
01893 }
01894 
01904 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01905 {
01906   Train *t = Train::GetIfValid(p1);
01907   if (t == NULL) return CMD_ERROR;
01908 
01909   if (!t->IsPrimaryVehicle()) return CMD_ERROR;
01910 
01911   CommandCost ret = CheckOwnership(t->owner);
01912   if (ret.Failed()) return ret;
01913 
01914 
01915   if (flags & DC_EXEC) {
01916     /* If we are forced to proceed, cancel that order.
01917      * If we are marked stuck we would want to force the train
01918      * to proceed to the next signal. In the other cases we
01919      * would like to pass the signal at danger and run till the
01920      * next signal we encounter. */
01921     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsChainInDepot() ? TFP_STUCK : TFP_SIGNAL;
01922     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01923   }
01924 
01925   return CommandCost();
01926 }
01927 
01935 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01936 {
01937   assert(!(v->vehstatus & VS_CRASHED));
01938 
01939   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01940 
01941   PBSTileInfo origin = FollowTrainReservation(v);
01942   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01943 
01944   switch (_settings_game.pf.pathfinder_for_trains) {
01945     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01946     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01947 
01948     default: NOT_REACHED();
01949   }
01950 }
01951 
01959 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01960 {
01961   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01962   if (tfdd.best_length == UINT_MAX) return false;
01963 
01964   if (location    != NULL) *location    = tfdd.tile;
01965   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01966   if (reverse     != NULL) *reverse     = tfdd.reverse;
01967 
01968   return true;
01969 }
01970 
01972 void Train::PlayLeaveStationSound() const
01973 {
01974   static const SoundFx sfx[] = {
01975     SND_04_TRAIN,
01976     SND_0A_TRAIN_HORN,
01977     SND_0A_TRAIN_HORN,
01978     SND_47_MAGLEV_2,
01979     SND_41_MAGLEV
01980   };
01981 
01982   if (PlayVehicleSound(this, VSE_START)) return;
01983 
01984   EngineID engtype = this->engine_type;
01985   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
01986 }
01987 
01992 static void CheckNextTrainTile(Train *v)
01993 {
01994   /* Don't do any look-ahead if path_backoff_interval is 255. */
01995   if (_settings_game.pf.path_backoff_interval == 255) return;
01996 
01997   /* Exit if we are inside a depot. */
01998   if (v->track == TRACK_BIT_DEPOT) return;
01999 
02000   switch (v->current_order.GetType()) {
02001     /* Exit if we reached our destination depot. */
02002     case OT_GOTO_DEPOT:
02003       if (v->tile == v->dest_tile) return;
02004       break;
02005 
02006     case OT_GOTO_WAYPOINT:
02007       /* If we reached our waypoint, make sure we see that. */
02008       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02009       break;
02010 
02011     case OT_NOTHING:
02012     case OT_LEAVESTATION:
02013     case OT_LOADING:
02014       /* Exit if the current order doesn't have a destination, but the train has orders. */
02015       if (v->GetNumOrders() > 0) return;
02016       break;
02017 
02018     default:
02019       break;
02020   }
02021   /* Exit if we are on a station tile and are going to stop. */
02022   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02023 
02024   Trackdir td = v->GetVehicleTrackdir();
02025 
02026   /* On a tile with a red non-pbs signal, don't look ahead. */
02027   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02028       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02029       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02030 
02031   CFollowTrackRail ft(v);
02032   if (!ft.Follow(v->tile, td)) return;
02033 
02034   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02035     /* Next tile is not reserved. */
02036     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02037       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02038         /* If the next tile is a PBS signal, try to make a reservation. */
02039         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02040         if (_settings_game.pf.forbid_90_deg) {
02041           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02042         }
02043         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02044       }
02045     }
02046   }
02047 }
02048 
02054 static bool CheckTrainStayInDepot(Train *v)
02055 {
02056   /* bail out if not all wagons are in the same depot or not in a depot at all */
02057   for (const Train *u = v; u != NULL; u = u->Next()) {
02058     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02059   }
02060 
02061   /* if the train got no power, then keep it in the depot */
02062   if (v->gcache.cached_power == 0) {
02063     v->vehstatus |= VS_STOPPED;
02064     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02065     return true;
02066   }
02067 
02068   SigSegState seg_state;
02069 
02070   if (v->force_proceed == TFP_NONE) {
02071     /* force proceed was not pressed */
02072     if (++v->wait_counter < 37) {
02073       SetWindowClassesDirty(WC_TRAINS_LIST);
02074       return true;
02075     }
02076 
02077     v->wait_counter = 0;
02078 
02079     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02080     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02081       /* Full and no PBS signal in block or depot reserved, can't exit. */
02082       SetWindowClassesDirty(WC_TRAINS_LIST);
02083       return true;
02084     }
02085   } else {
02086     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02087   }
02088 
02089   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02090   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02091     /* We need to have a reservation for this to work. */
02092     if (HasDepotReservation(v->tile)) return true;
02093     SetDepotReservation(v->tile, true);
02094     VehicleEnterDepot(v);
02095     return true;
02096   }
02097 
02098   /* Only leave when we can reserve a path to our destination. */
02099   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02100     /* No path and no force proceed. */
02101     SetWindowClassesDirty(WC_TRAINS_LIST);
02102     MarkTrainAsStuck(v);
02103     return true;
02104   }
02105 
02106   SetDepotReservation(v->tile, true);
02107   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02108 
02109   VehicleServiceInDepot(v);
02110   SetWindowClassesDirty(WC_TRAINS_LIST);
02111   v->PlayLeaveStationSound();
02112 
02113   v->track = TRACK_BIT_X;
02114   if (v->direction & 2) v->track = TRACK_BIT_Y;
02115 
02116   v->vehstatus &= ~VS_HIDDEN;
02117   v->cur_speed = 0;
02118 
02119   v->UpdateViewport(true, true);
02120   VehicleUpdatePosition(v);
02121   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02122   v->UpdateAcceleration();
02123   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02124 
02125   return false;
02126 }
02127 
02134 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02135 {
02136   DiagDirection dir = TrackdirToExitdir(track_dir);
02137 
02138   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02139     /* Are we just leaving a tunnel/bridge? */
02140     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02141       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02142 
02143       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02144         /* Free the reservation only if no other train is on the tiles. */
02145         SetTunnelBridgeReservation(tile, false);
02146         SetTunnelBridgeReservation(end, false);
02147 
02148         if (_settings_client.gui.show_track_reservation) {
02149           MarkTileDirtyByTile(tile);
02150           MarkTileDirtyByTile(end);
02151         }
02152       }
02153     }
02154   } else if (IsRailStationTile(tile)) {
02155     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02156     /* If the new tile is not a further tile of the same station, we
02157      * clear the reservation for the whole platform. */
02158     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02159       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02160     }
02161   } else {
02162     /* Any other tile */
02163     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02164   }
02165 }
02166 
02173 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02174 {
02175   assert(v->IsFrontEngine());
02176 
02177   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02178   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02179   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02180   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02181 
02182   /* Can't be holding a reservation if we enter a depot. */
02183   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02184   if (v->track == TRACK_BIT_DEPOT) {
02185     /* Front engine is in a depot. We enter if some part is not in the depot. */
02186     for (const Train *u = v; u != NULL; u = u->Next()) {
02187       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02188     }
02189   }
02190   /* Don't free reservation if it's not ours. */
02191   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02192 
02193   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02194   while (ft.Follow(tile, td)) {
02195     tile = ft.m_new_tile;
02196     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02197     td = RemoveFirstTrackdir(&bits);
02198     assert(bits == TRACKDIR_BIT_NONE);
02199 
02200     if (!IsValidTrackdir(td)) break;
02201 
02202     if (IsTileType(tile, MP_RAILWAY)) {
02203       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02204         /* Conventional signal along trackdir: remove reservation and stop. */
02205         UnreserveRailTrack(tile, TrackdirToTrack(td));
02206         break;
02207       }
02208       if (HasPbsSignalOnTrackdir(tile, td)) {
02209         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02210           /* Red PBS signal? Can't be our reservation, would be green then. */
02211           break;
02212         } else {
02213           /* Turn the signal back to red. */
02214           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02215           MarkTileDirtyByTile(tile);
02216         }
02217       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02218         break;
02219       }
02220     }
02221 
02222     /* Don't free first station/bridge/tunnel if we are on it. */
02223     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);
02224 
02225     free_tile = true;
02226   }
02227 }
02228 
02229 static const byte _initial_tile_subcoord[6][4][3] = {
02230 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02231 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02232 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02233 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02234 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02235 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02236 };
02237 
02250 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02251 {
02252   switch (_settings_game.pf.pathfinder_for_trains) {
02253     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02254     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02255 
02256     default: NOT_REACHED();
02257   }
02258 }
02259 
02265 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02266 {
02267   PBSTileInfo origin = FollowTrainReservation(v);
02268 
02269   CFollowTrackRail ft(v);
02270 
02271   TileIndex tile = origin.tile;
02272   Trackdir  cur_td = origin.trackdir;
02273   while (ft.Follow(tile, cur_td)) {
02274     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02275       /* Possible signal tile. */
02276       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02277     }
02278 
02279     if (_settings_game.pf.forbid_90_deg) {
02280       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02281       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02282     }
02283 
02284     /* Station, depot or waypoint are a possible target. */
02285     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02286     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02287       /* Choice found or possible target encountered.
02288        * On finding a possible target, we need to stop and let the pathfinder handle the
02289        * remaining path. This is because we don't know if this target is in one of our
02290        * orders, so we might cause pathfinding to fail later on if we find a choice.
02291        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02292        * a wrong path not leading to our next destination. */
02293       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02294 
02295       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02296        * actually starts its search at the first unreserved tile. */
02297       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02298 
02299       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02300       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02301       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02302       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02303     }
02304 
02305     tile = ft.m_new_tile;
02306     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02307 
02308     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02309       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02310       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02311       /* Safe position is all good, path valid and okay. */
02312       return PBSTileInfo(tile, cur_td, true);
02313     }
02314 
02315     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02316   }
02317 
02318   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02319     /* End of line, path valid and okay. */
02320     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02321   }
02322 
02323   /* Sorry, can't reserve path, back out. */
02324   tile = origin.tile;
02325   cur_td = origin.trackdir;
02326   TileIndex stopped = ft.m_old_tile;
02327   Trackdir  stopped_td = ft.m_old_td;
02328   while (tile != stopped || cur_td != stopped_td) {
02329     if (!ft.Follow(tile, cur_td)) break;
02330 
02331     if (_settings_game.pf.forbid_90_deg) {
02332       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02333       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02334     }
02335     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02336 
02337     tile = ft.m_new_tile;
02338     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02339 
02340     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02341   }
02342 
02343   /* Path invalid. */
02344   return PBSTileInfo();
02345 }
02346 
02357 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02358 {
02359   switch (_settings_game.pf.pathfinder_for_trains) {
02360     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02361     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02362 
02363     default: NOT_REACHED();
02364   }
02365 }
02366 
02368 class VehicleOrderSaver {
02369 private:
02370   Train          *v;
02371   Order          old_order;
02372   TileIndex      old_dest_tile;
02373   StationID      old_last_station_visited;
02374   VehicleOrderID index;
02375   bool           suppress_implicit_orders;
02376 
02377 public:
02378   VehicleOrderSaver(Train *_v) :
02379     v(_v),
02380     old_order(_v->current_order),
02381     old_dest_tile(_v->dest_tile),
02382     old_last_station_visited(_v->last_station_visited),
02383     index(_v->cur_real_order_index),
02384     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02385   {
02386   }
02387 
02388   ~VehicleOrderSaver()
02389   {
02390     this->v->current_order = this->old_order;
02391     this->v->dest_tile = this->old_dest_tile;
02392     this->v->last_station_visited = this->old_last_station_visited;
02393     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02394   }
02395 
02401   bool SwitchToNextOrder(bool skip_first)
02402   {
02403     if (this->v->GetNumOrders() == 0) return false;
02404 
02405     if (skip_first) ++this->index;
02406 
02407     int depth = 0;
02408 
02409     do {
02410       /* Wrap around. */
02411       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02412 
02413       Order *order = this->v->GetOrder(this->index);
02414       assert(order != NULL);
02415 
02416       switch (order->GetType()) {
02417         case OT_GOTO_DEPOT:
02418           /* Skip service in depot orders when the train doesn't need service. */
02419           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02420         case OT_GOTO_STATION:
02421         case OT_GOTO_WAYPOINT:
02422           this->v->current_order = *order;
02423           return UpdateOrderDest(this->v, order, 0, true);
02424         case OT_CONDITIONAL: {
02425           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02426           if (next != INVALID_VEH_ORDER_ID) {
02427             depth++;
02428             this->index = next;
02429             /* Don't increment next, so no break here. */
02430             continue;
02431           }
02432           break;
02433         }
02434         default:
02435           break;
02436       }
02437       /* Don't increment inside the while because otherwise conditional
02438        * orders can lead to an infinite loop. */
02439       ++this->index;
02440       depth++;
02441     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02442 
02443     return false;
02444   }
02445 };
02446 
02447 /* choose a track */
02448 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02449 {
02450   Track best_track = INVALID_TRACK;
02451   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02452   bool changed_signal = false;
02453 
02454   assert((tracks & ~TRACK_BIT_MASK) == 0);
02455 
02456   if (got_reservation != NULL) *got_reservation = false;
02457 
02458   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02459   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02460   /* Do we have a suitable reserved track? */
02461   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02462 
02463   /* Quick return in case only one possible track is available */
02464   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02465     Track track = FindFirstTrack(tracks);
02466     /* We need to check for signals only here, as a junction tile can't have signals. */
02467     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02468       do_track_reservation = true;
02469       changed_signal = true;
02470       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02471     } else if (!do_track_reservation) {
02472       return track;
02473     }
02474     best_track = track;
02475   }
02476 
02477   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02478   DiagDirection dest_enterdir = enterdir;
02479   if (do_track_reservation) {
02480     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02481     if (res_dest.tile == INVALID_TILE) {
02482       /* Reservation failed? */
02483       if (mark_stuck) MarkTrainAsStuck(v);
02484       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02485       return FindFirstTrack(tracks);
02486     }
02487     if (res_dest.okay) {
02488       /* Got a valid reservation that ends at a safe target, quick exit. */
02489       if (got_reservation != NULL) *got_reservation = true;
02490       if (changed_signal) MarkTileDirtyByTile(tile);
02491       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02492       return best_track;
02493     }
02494 
02495     /* Check if the train needs service here, so it has a chance to always find a depot.
02496      * Also check if the current order is a service order so we don't reserve a path to
02497      * the destination but instead to the next one if service isn't needed. */
02498     CheckIfTrainNeedsService(v);
02499     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02500   }
02501 
02502   /* Save the current train order. The destructor will restore the old order on function exit. */
02503   VehicleOrderSaver orders(v);
02504 
02505   /* If the current tile is the destination of the current order and
02506    * a reservation was requested, advance to the next order.
02507    * Don't advance on a depot order as depots are always safe end points
02508    * for a path and no look-ahead is necessary. This also avoids a
02509    * problem with depot orders not part of the order list when the
02510    * order list itself is empty. */
02511   if (v->current_order.IsType(OT_LEAVESTATION)) {
02512     orders.SwitchToNextOrder(false);
02513   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02514       v->current_order.IsType(OT_GOTO_STATION) ?
02515       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02516       v->tile == v->dest_tile))) {
02517     orders.SwitchToNextOrder(true);
02518   }
02519 
02520   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02521     /* Pathfinders are able to tell that route was only 'guessed'. */
02522     bool      path_found = true;
02523     TileIndex new_tile = res_dest.tile;
02524 
02525     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02526     if (new_tile == tile) best_track = next_track;
02527     v->HandlePathfindingResult(path_found);
02528   }
02529 
02530   /* No track reservation requested -> finished. */
02531   if (!do_track_reservation) return best_track;
02532 
02533   /* A path was found, but could not be reserved. */
02534   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02535     if (mark_stuck) MarkTrainAsStuck(v);
02536     FreeTrainTrackReservation(v);
02537     return best_track;
02538   }
02539 
02540   /* No possible reservation target found, we are probably lost. */
02541   if (res_dest.tile == INVALID_TILE) {
02542     /* Try to find any safe destination. */
02543     PBSTileInfo origin = FollowTrainReservation(v);
02544     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02545       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02546       best_track = FindFirstTrack(res);
02547       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02548       if (got_reservation != NULL) *got_reservation = true;
02549       if (changed_signal) MarkTileDirtyByTile(tile);
02550     } else {
02551       FreeTrainTrackReservation(v);
02552       if (mark_stuck) MarkTrainAsStuck(v);
02553     }
02554     return best_track;
02555   }
02556 
02557   if (got_reservation != NULL) *got_reservation = true;
02558 
02559   /* Reservation target found and free, check if it is safe. */
02560   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02561     /* Extend reservation until we have found a safe position. */
02562     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02563     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02564     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02565     if (_settings_game.pf.forbid_90_deg) {
02566       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02567     }
02568 
02569     /* Get next order with destination. */
02570     if (orders.SwitchToNextOrder(true)) {
02571       PBSTileInfo cur_dest;
02572       bool path_found;
02573       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02574       if (cur_dest.tile != INVALID_TILE) {
02575         res_dest = cur_dest;
02576         if (res_dest.okay) continue;
02577         /* Path found, but could not be reserved. */
02578         FreeTrainTrackReservation(v);
02579         if (mark_stuck) MarkTrainAsStuck(v);
02580         if (got_reservation != NULL) *got_reservation = false;
02581         changed_signal = false;
02582         break;
02583       }
02584     }
02585     /* No order or no safe position found, try any position. */
02586     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02587       FreeTrainTrackReservation(v);
02588       if (mark_stuck) MarkTrainAsStuck(v);
02589       if (got_reservation != NULL) *got_reservation = false;
02590       changed_signal = false;
02591     }
02592     break;
02593   }
02594 
02595   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02596 
02597   if (changed_signal) MarkTileDirtyByTile(tile);
02598 
02599   return best_track;
02600 }
02601 
02610 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02611 {
02612   assert(v->IsFrontEngine());
02613 
02614   /* We have to handle depots specially as the track follower won't look
02615    * at the depot tile itself but starts from the next tile. If we are still
02616    * inside the depot, a depot reservation can never be ours. */
02617   if (v->track == TRACK_BIT_DEPOT) {
02618     if (HasDepotReservation(v->tile)) {
02619       if (mark_as_stuck) MarkTrainAsStuck(v);
02620       return false;
02621     } else {
02622       /* Depot not reserved, but the next tile might be. */
02623       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02624       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02625     }
02626   }
02627 
02628   Vehicle *other_train = NULL;
02629   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02630   /* The path we are driving on is already blocked by some other train.
02631    * This can only happen in certain situations when mixing path and
02632    * block signals or when changing tracks and/or signals.
02633    * Exit here as doing any further reservations will probably just
02634    * make matters worse. */
02635   if (other_train != NULL && other_train->index != v->index) {
02636     if (mark_as_stuck) MarkTrainAsStuck(v);
02637     return false;
02638   }
02639   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02640   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02641     /* Can't be stuck then. */
02642     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02643     ClrBit(v->flags, VRF_TRAIN_STUCK);
02644     return true;
02645   }
02646 
02647   /* If we are in a depot, tentatively reserve the depot. */
02648   if (v->track == TRACK_BIT_DEPOT) {
02649     SetDepotReservation(v->tile, true);
02650     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02651   }
02652 
02653   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02654   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02655   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02656 
02657   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02658 
02659   bool res_made = false;
02660   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02661 
02662   if (!res_made) {
02663     /* Free the depot reservation as well. */
02664     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02665     return false;
02666   }
02667 
02668   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02669     v->wait_counter = 0;
02670     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02671   }
02672   ClrBit(v->flags, VRF_TRAIN_STUCK);
02673   return true;
02674 }
02675 
02676 
02677 static bool CheckReverseTrain(const Train *v)
02678 {
02679   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02680       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02681       !(v->direction & 1)) {
02682     return false;
02683   }
02684 
02685   assert(v->track != TRACK_BIT_NONE);
02686 
02687   switch (_settings_game.pf.pathfinder_for_trains) {
02688     case VPF_NPF: return NPFTrainCheckReverse(v);
02689     case VPF_YAPF: return YapfTrainCheckReverse(v);
02690 
02691     default: NOT_REACHED();
02692   }
02693 }
02694 
02700 TileIndex Train::GetOrderStationLocation(StationID station)
02701 {
02702   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02703 
02704   const Station *st = Station::Get(station);
02705   if (!(st->facilities & FACIL_TRAIN)) {
02706     /* The destination station has no trainstation tiles. */
02707     this->IncrementRealOrderIndex();
02708     return 0;
02709   }
02710 
02711   return st->xy;
02712 }
02713 
02715 void Train::MarkDirty()
02716 {
02717   Train *v = this;
02718   do {
02719     v->UpdateViewport(false, false);
02720   } while ((v = v->Next()) != NULL);
02721 
02722   /* need to update acceleration and cached values since the goods on the train changed. */
02723   this->CargoChanged();
02724   this->UpdateAcceleration();
02725 }
02726 
02734 int Train::UpdateSpeed()
02735 {
02736   switch (_settings_game.vehicle.train_acceleration_model) {
02737     default: NOT_REACHED();
02738     case AM_ORIGINAL:
02739       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, min(this->gcache.cached_max_track_speed, this->current_order.max_speed));
02740 
02741     case AM_REALISTIC:
02742       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02743   }
02744 }
02745 
02751 static void TrainEnterStation(Train *v, StationID station)
02752 {
02753   v->last_station_visited = station;
02754 
02755   /* check if a train ever visited this station before */
02756   Station *st = Station::Get(station);
02757   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02758     st->had_vehicle_of_type |= HVOT_TRAIN;
02759     SetDParam(0, st->index);
02760     AddVehicleNewsItem(
02761       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02762       v->owner == _local_company ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
02763       v->index,
02764       st->index
02765     );
02766     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02767     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02768   }
02769 
02770   v->force_proceed = TFP_NONE;
02771   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02772 
02773   v->BeginLoading();
02774 
02775   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02776 }
02777 
02778 /* Check if the vehicle is compatible with the specified tile */
02779 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02780 {
02781   return IsTileOwner(tile, v->owner) &&
02782       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02783 }
02784 
02786 struct AccelerationSlowdownParams {
02787   byte small_turn; 
02788   byte large_turn; 
02789   byte z_up;       
02790   byte z_down;     
02791 };
02792 
02794 static const AccelerationSlowdownParams _accel_slowdown[] = {
02795   /* normal accel */
02796   {256 / 4, 256 / 2, 256 / 4, 2}, 
02797   {256 / 4, 256 / 2, 256 / 4, 2}, 
02798   {0,       256 / 2, 256 / 4, 2}, 
02799 };
02800 
02806 static inline void AffectSpeedByZChange(Train *v, int old_z)
02807 {
02808   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02809 
02810   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02811 
02812   if (old_z < v->z_pos) {
02813     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02814   } else {
02815     uint16 spd = v->cur_speed + asp->z_down;
02816     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02817   }
02818 }
02819 
02820 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02821 {
02822   if (IsTileType(tile, MP_RAILWAY) &&
02823       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02824     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02825     Trackdir trackdir = FindFirstTrackdir(tracks);
02826     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02827       /* A PBS block with a non-PBS signal facing us? */
02828       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02829     }
02830   }
02831   return false;
02832 }
02833 
02835 void Train::ReserveTrackUnderConsist() const
02836 {
02837   for (const Train *u = this; u != NULL; u = u->Next()) {
02838     switch (u->track) {
02839       case TRACK_BIT_WORMHOLE:
02840         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02841         break;
02842       case TRACK_BIT_DEPOT:
02843         break;
02844       default:
02845         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02846         break;
02847     }
02848   }
02849 }
02850 
02857 uint Train::Crash(bool flooded)
02858 {
02859   uint pass = 0;
02860   if (this->IsFrontEngine()) {
02861     pass += 2; // driver
02862 
02863     /* Remove the reserved path in front of the train if it is not stuck.
02864      * Also clear all reserved tracks the train is currently on. */
02865     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02866     for (const Train *v = this; v != NULL; v = v->Next()) {
02867       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02868       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02869         /* ClearPathReservation will not free the wormhole exit
02870          * if the train has just entered the wormhole. */
02871         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02872       }
02873     }
02874 
02875     /* we may need to update crossing we were approaching,
02876      * but must be updated after the train has been marked crashed */
02877     TileIndex crossing = TrainApproachingCrossingTile(this);
02878     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02879 
02880     /* Remove the loading indicators (if any) */
02881     HideFillingPercent(&this->fill_percent_te_id);
02882   }
02883 
02884   pass += this->GroundVehicleBase::Crash(flooded);
02885 
02886   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02887   return pass;
02888 }
02889 
02896 static uint TrainCrashed(Train *v)
02897 {
02898   uint num = 0;
02899 
02900   /* do not crash train twice */
02901   if (!(v->vehstatus & VS_CRASHED)) {
02902     num = v->Crash();
02903     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02904     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02905   }
02906 
02907   /* Try to re-reserve track under already crashed train too.
02908    * Crash() clears the reservation! */
02909   v->ReserveTrackUnderConsist();
02910 
02911   return num;
02912 }
02913 
02915 struct TrainCollideChecker {
02916   Train *v; 
02917   uint num; 
02918 };
02919 
02926 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02927 {
02928   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02929 
02930   /* not a train or in depot */
02931   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02932 
02933   /* do not crash into trains of another company. */
02934   if (v->owner != tcc->v->owner) return NULL;
02935 
02936   /* get first vehicle now to make most usual checks faster */
02937   Train *coll = Train::From(v)->First();
02938 
02939   /* can't collide with own wagons */
02940   if (coll == tcc->v) return NULL;
02941 
02942   int x_diff = v->x_pos - tcc->v->x_pos;
02943   int y_diff = v->y_pos - tcc->v->y_pos;
02944 
02945   /* Do fast calculation to check whether trains are not in close vicinity
02946    * and quickly reject trains distant enough for any collision.
02947    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02948    * Differences are then ORed and then we check for any higher bits */
02949   uint hash = (y_diff + 7) | (x_diff + 7);
02950   if (hash & ~15) return NULL;
02951 
02952   /* Slower check using multiplication */
02953   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02954   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02955 
02956   /* Happens when there is a train under bridge next to bridge head */
02957   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02958 
02959   /* crash both trains */
02960   tcc->num += TrainCrashed(tcc->v);
02961   tcc->num += TrainCrashed(coll);
02962 
02963   return NULL; // continue searching
02964 }
02965 
02973 static bool CheckTrainCollision(Train *v)
02974 {
02975   /* can't collide in depot */
02976   if (v->track == TRACK_BIT_DEPOT) return false;
02977 
02978   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
02979 
02980   TrainCollideChecker tcc;
02981   tcc.v = v;
02982   tcc.num = 0;
02983 
02984   /* find colliding vehicles */
02985   if (v->track == TRACK_BIT_WORMHOLE) {
02986     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
02987     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
02988   } else {
02989     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
02990   }
02991 
02992   /* any dead -> no crash */
02993   if (tcc.num == 0) return false;
02994 
02995   SetDParam(0, tcc.num);
02996   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH, NT_ACCIDENT, v->index);
02997 
02998   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
02999   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03000   return true;
03001 }
03002 
03003 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03004 {
03005   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03006 
03007   Train *t = Train::From(v);
03008   DiagDirection exitdir = *(DiagDirection *)data;
03009 
03010   /* not front engine of a train, inside wormhole or depot, crashed */
03011   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03012 
03013   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03014 
03015   return t;
03016 }
03017 
03025 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03026 {
03027   Train *first = v->First();
03028   Train *prev;
03029   bool direction_changed = false; // has direction of any part changed?
03030 
03031   /* For every vehicle after and including the given vehicle */
03032   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03033     DiagDirection enterdir = DIAGDIR_BEGIN;
03034     bool update_signals_crossing = false; // will we update signals or crossing state?
03035 
03036     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03037     if (v->track != TRACK_BIT_WORMHOLE) {
03038       /* Not inside tunnel */
03039       if (gp.old_tile == gp.new_tile) {
03040         /* Staying in the old tile */
03041         if (v->track == TRACK_BIT_DEPOT) {
03042           /* Inside depot */
03043           gp.x = v->x_pos;
03044           gp.y = v->y_pos;
03045         } else {
03046           /* Not inside depot */
03047 
03048           /* Reverse when we are at the end of the track already, do not move to the new position */
03049           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03050 
03051           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03052           if (HasBit(r, VETS_CANNOT_ENTER)) {
03053             goto invalid_rail;
03054           }
03055           if (HasBit(r, VETS_ENTERED_STATION)) {
03056             /* The new position is the end of the platform */
03057             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03058           }
03059         }
03060       } else {
03061         /* A new tile is about to be entered. */
03062 
03063         /* Determine what direction we're entering the new tile from */
03064         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03065         assert(IsValidDiagDirection(enterdir));
03066 
03067         /* Get the status of the tracks in the new tile and mask
03068          * away the bits that aren't reachable. */
03069         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03070         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03071 
03072         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03073         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03074 
03075         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03076         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03077           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03078            * can be switched on halfway a turn */
03079           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03080         }
03081 
03082         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03083 
03084         /* Check if the new tile constrains tracks that are compatible
03085          * with the current train, if not, bail out. */
03086         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03087 
03088         TrackBits chosen_track;
03089         if (prev == NULL) {
03090           /* Currently the locomotive is active. Determine which one of the
03091            * available tracks to choose */
03092           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03093           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03094 
03095           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03096             /* For each signal we find decrease the counter by one.
03097              * We start at two, so the first signal we pass decreases
03098              * this to one, then if we reach the next signal it is
03099              * decreased to zero and we won't pass that new signal. */
03100             Trackdir dir = FindFirstTrackdir(trackdirbits);
03101             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03102                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03103               /* However, we do not want to be stopped by PBS signals
03104                * entered via the back. */
03105               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03106               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03107             }
03108           }
03109 
03110           /* Check if it's a red signal and that force proceed is not clicked. */
03111           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03112             /* In front of a red signal */
03113             Trackdir i = FindFirstTrackdir(trackdirbits);
03114 
03115             /* Don't handle stuck trains here. */
03116             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03117 
03118             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03119               v->cur_speed = 0;
03120               v->subspeed = 0;
03121               v->progress = 255 - 100;
03122               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03123             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03124               v->cur_speed = 0;
03125               v->subspeed = 0;
03126               v->progress = 255 - 10;
03127               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03128                 DiagDirection exitdir = TrackdirToExitdir(i);
03129                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03130 
03131                 exitdir = ReverseDiagDir(exitdir);
03132 
03133                 /* check if a train is waiting on the other side */
03134                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03135               }
03136             }
03137 
03138             /* If we would reverse but are currently in a PBS block and
03139              * reversing of stuck trains is disabled, don't reverse.
03140              * This does not apply if the reason for reversing is a one-way
03141              * signal blocking us, because a train would then be stuck forever. */
03142             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03143                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03144               v->wait_counter = 0;
03145               return false;
03146             }
03147             goto reverse_train_direction;
03148           } else {
03149             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03150           }
03151         } else {
03152           /* The wagon is active, simply follow the prev vehicle. */
03153           if (prev->tile == gp.new_tile) {
03154             /* Choose the same track as prev */
03155             if (prev->track == TRACK_BIT_WORMHOLE) {
03156               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03157                * However, just choose the track into the wormhole. */
03158               assert(IsTunnel(prev->tile));
03159               chosen_track = bits;
03160             } else {
03161               chosen_track = prev->track;
03162             }
03163           } else {
03164             /* Choose the track that leads to the tile where prev is.
03165              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03166              * I.e. when the tile between them has only space for a single vehicle like
03167              *  1) horizontal/vertical track tiles and
03168              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03169              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03170              */
03171             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03172               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03173               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03174               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03175               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03176             };
03177             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03178             assert(IsValidDiagDirection(exitdir));
03179             chosen_track = _connecting_track[enterdir][exitdir];
03180           }
03181           chosen_track &= bits;
03182         }
03183 
03184         /* Make sure chosen track is a valid track */
03185         assert(
03186             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03187             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03188             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03189 
03190         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03191         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03192         gp.x = (gp.x & ~0xF) | b[0];
03193         gp.y = (gp.y & ~0xF) | b[1];
03194         Direction chosen_dir = (Direction)b[2];
03195 
03196         /* Call the landscape function and tell it that the vehicle entered the tile */
03197         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03198         if (HasBit(r, VETS_CANNOT_ENTER)) {
03199           goto invalid_rail;
03200         }
03201 
03202         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03203           Track track = FindFirstTrack(chosen_track);
03204           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03205           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03206             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03207             MarkTileDirtyByTile(gp.new_tile);
03208           }
03209 
03210           /* Clear any track reservation when the last vehicle leaves the tile */
03211           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03212 
03213           v->tile = gp.new_tile;
03214 
03215           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03216             v->First()->ConsistChanged(true);
03217           }
03218 
03219           v->track = chosen_track;
03220           assert(v->track);
03221         }
03222 
03223         /* We need to update signal status, but after the vehicle position hash
03224          * has been updated by UpdateInclination() */
03225         update_signals_crossing = true;
03226 
03227         if (chosen_dir != v->direction) {
03228           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03229             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03230             DirDiff diff = DirDifference(v->direction, chosen_dir);
03231             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03232           }
03233           direction_changed = true;
03234           v->direction = chosen_dir;
03235         }
03236 
03237         if (v->IsFrontEngine()) {
03238           v->wait_counter = 0;
03239 
03240           /* If we are approaching a crossing that is reserved, play the sound now. */
03241           TileIndex crossing = TrainApproachingCrossingTile(v);
03242           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03243 
03244           /* Always try to extend the reservation when entering a tile. */
03245           CheckNextTrainTile(v);
03246         }
03247 
03248         if (HasBit(r, VETS_ENTERED_STATION)) {
03249           /* The new position is the location where we want to stop */
03250           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03251         }
03252       }
03253     } else {
03254       /* In a tunnel or on a bridge
03255        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03256        * - for bridges, only the middle part - without the bridge heads */
03257       if (!(v->vehstatus & VS_HIDDEN)) {
03258         Train *first = v->First();
03259         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03260       }
03261 
03262       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03263         /* Perform look-ahead on tunnel exit. */
03264         if (v->IsFrontEngine()) {
03265           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03266           CheckNextTrainTile(v);
03267         }
03268         /* Prevent v->UpdateInclination() being called with wrong parameters.
03269          * This could happen if the train was reversed inside the tunnel/bridge. */
03270         if (gp.old_tile == gp.new_tile) {
03271           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03272         }
03273       } else {
03274         v->x_pos = gp.x;
03275         v->y_pos = gp.y;
03276         VehicleUpdatePosition(v);
03277         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03278         continue;
03279       }
03280     }
03281 
03282     /* update image of train, as well as delta XY */
03283     v->UpdateDeltaXY(v->direction);
03284 
03285     v->x_pos = gp.x;
03286     v->y_pos = gp.y;
03287     VehicleUpdatePosition(v);
03288 
03289     /* update the Z position of the vehicle */
03290     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03291 
03292     if (prev == NULL) {
03293       /* This is the first vehicle in the train */
03294       AffectSpeedByZChange(v, old_z);
03295     }
03296 
03297     if (update_signals_crossing) {
03298       if (v->IsFrontEngine()) {
03299         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03300           /* We are entering a block with PBS signals right now, but
03301            * not through a PBS signal. This means we don't have a
03302            * reservation right now. As a conventional signal will only
03303            * ever be green if no other train is in the block, getting
03304            * a path should always be possible. If the player built
03305            * such a strange network that it is not possible, the train
03306            * will be marked as stuck and the player has to deal with
03307            * the problem. */
03308           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03309               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03310               !TryPathReserve(v)) {
03311             MarkTrainAsStuck(v);
03312           }
03313         }
03314       }
03315 
03316       /* Signals can only change when the first
03317        * (above) or the last vehicle moves. */
03318       if (v->Next() == NULL) {
03319         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03320         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03321       }
03322     }
03323 
03324     /* Do not check on every tick to save some computing time. */
03325     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03326   }
03327 
03328   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03329 
03330   return true;
03331 
03332 invalid_rail:
03333   /* We've reached end of line?? */
03334   if (prev != NULL) error("Disconnecting train");
03335 
03336 reverse_train_direction:
03337   if (reverse) {
03338     v->wait_counter = 0;
03339     v->cur_speed = 0;
03340     v->subspeed = 0;
03341     ReverseTrainDirection(v);
03342   }
03343 
03344   return false;
03345 }
03346 
03353 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03354 {
03355   TrackBits *trackbits = (TrackBits *)data;
03356 
03357   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03358     TrackBits train_tbits = Train::From(v)->track;
03359     if (train_tbits == TRACK_BIT_WORMHOLE) {
03360       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03361       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03362     } else if (train_tbits != TRACK_BIT_DEPOT) {
03363       *trackbits |= train_tbits;
03364     }
03365   }
03366 
03367   return NULL;
03368 }
03369 
03377 static void DeleteLastWagon(Train *v)
03378 {
03379   Train *first = v->First();
03380 
03381   /* Go to the last wagon and delete the link pointing there
03382    * *u is then the one-before-last wagon, and *v the last
03383    * one which will physically be removed */
03384   Train *u = v;
03385   for (; v->Next() != NULL; v = v->Next()) u = v;
03386   u->SetNext(NULL);
03387 
03388   if (first != v) {
03389     /* Recalculate cached train properties */
03390     first->ConsistChanged(false);
03391     /* Update the depot window if the first vehicle is in depot -
03392      * if v == first, then it is updated in PreDestructor() */
03393     if (first->track == TRACK_BIT_DEPOT) {
03394       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03395     }
03396   }
03397 
03398   /* 'v' shouldn't be accessed after it has been deleted */
03399   TrackBits trackbits = v->track;
03400   TileIndex tile = v->tile;
03401   Owner owner = v->owner;
03402 
03403   delete v;
03404   v = NULL; // make sure nobody will try to read 'v' anymore
03405 
03406   if (trackbits == TRACK_BIT_WORMHOLE) {
03407     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03408     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03409   }
03410 
03411   Track track = TrackBitsToTrack(trackbits);
03412   if (HasReservedTracks(tile, trackbits)) {
03413     UnreserveRailTrack(tile, track);
03414 
03415     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03416     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03417     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03418 
03419     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03420     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03421     Track t;
03422     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03423   }
03424 
03425   /* check if the wagon was on a road/rail-crossing */
03426   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03427 
03428   /* Update signals */
03429   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03430     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03431   } else {
03432     SetSignalsOnBothDir(tile, track, owner);
03433   }
03434 }
03435 
03440 static void ChangeTrainDirRandomly(Train *v)
03441 {
03442   static const DirDiff delta[] = {
03443     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03444   };
03445 
03446   do {
03447     /* We don't need to twist around vehicles if they're not visible */
03448     if (!(v->vehstatus & VS_HIDDEN)) {
03449       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03450       v->UpdateDeltaXY(v->direction);
03451       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03452       /* Refrain from updating the z position of the vehicle when on
03453        * a bridge, because UpdateInclination() will put the vehicle under
03454        * the bridge in that case */
03455       if (v->track != TRACK_BIT_WORMHOLE) {
03456         VehicleUpdatePosition(v);
03457         v->UpdateInclination(false, false);
03458       }
03459     }
03460   } while ((v = v->Next()) != NULL);
03461 }
03462 
03468 static bool HandleCrashedTrain(Train *v)
03469 {
03470   int state = ++v->crash_anim_pos;
03471 
03472   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03473     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03474   }
03475 
03476   uint32 r;
03477   if (state <= 200 && Chance16R(1, 7, r)) {
03478     int index = (r * 10 >> 16);
03479 
03480     Vehicle *u = v;
03481     do {
03482       if (--index < 0) {
03483         r = Random();
03484 
03485         CreateEffectVehicleRel(u,
03486           GB(r,  8, 3) + 2,
03487           GB(r, 16, 3) + 2,
03488           GB(r,  0, 3) + 5,
03489           EV_EXPLOSION_SMALL);
03490         break;
03491       }
03492     } while ((u = u->Next()) != NULL);
03493   }
03494 
03495   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03496 
03497   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03498     bool ret = v->Next() != NULL;
03499     DeleteLastWagon(v);
03500     return ret;
03501   }
03502 
03503   return true;
03504 }
03505 
03507 static const uint16 _breakdown_speeds[16] = {
03508   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03509 };
03510 
03511 
03520 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03521 {
03522   /* Calc position within the current tile */
03523   uint x = v->x_pos & 0xF;
03524   uint y = v->y_pos & 0xF;
03525 
03526   /* for diagonal directions, 'x' will be 0..15 -
03527    * for other directions, it will be 1, 3, 5, ..., 15 */
03528   switch (v->direction) {
03529     case DIR_N : x = ~x + ~y + 25; break;
03530     case DIR_NW: x = y;            // FALL THROUGH
03531     case DIR_NE: x = ~x + 16;      break;
03532     case DIR_E : x = ~x + y + 9;   break;
03533     case DIR_SE: x = y;            break;
03534     case DIR_S : x = x + y - 7;    break;
03535     case DIR_W : x = ~y + x + 9;   break;
03536     default: break;
03537   }
03538 
03539   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03540    * does not cross the tile boundary when we do reverse, but as the vehicle's
03541    * location is based on their center, use half a vehicle's length as offset.
03542    * Multiply the half-length by two for straight directions to compensate that
03543    * we only get odd x offsets there. */
03544   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03545     /* we are too near the tile end, reverse now */
03546     v->cur_speed = 0;
03547     if (reverse) ReverseTrainDirection(v);
03548     return false;
03549   }
03550 
03551   /* slow down */
03552   v->vehstatus |= VS_TRAIN_SLOWING;
03553   uint16 break_speed = _breakdown_speeds[x & 0xF];
03554   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03555 
03556   return true;
03557 }
03558 
03559 
03565 static bool TrainCanLeaveTile(const Train *v)
03566 {
03567   /* Exit if inside a tunnel/bridge or a depot */
03568   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03569 
03570   TileIndex tile = v->tile;
03571 
03572   /* entering a tunnel/bridge? */
03573   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03574     DiagDirection dir = GetTunnelBridgeDirection(tile);
03575     if (DiagDirToDir(dir) == v->direction) return false;
03576   }
03577 
03578   /* entering a depot? */
03579   if (IsRailDepotTile(tile)) {
03580     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03581     if (DiagDirToDir(dir) == v->direction) return false;
03582   }
03583 
03584   return true;
03585 }
03586 
03587 
03595 static TileIndex TrainApproachingCrossingTile(const Train *v)
03596 {
03597   assert(v->IsFrontEngine());
03598   assert(!(v->vehstatus & VS_CRASHED));
03599 
03600   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03601 
03602   DiagDirection dir = TrainExitDir(v->direction, v->track);
03603   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03604 
03605   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03606   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03607       !CheckCompatibleRail(v, tile)) {
03608     return INVALID_TILE;
03609   }
03610 
03611   return tile;
03612 }
03613 
03614 
03622 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03623 {
03624   /* First, handle broken down train */
03625 
03626   int t = v->breakdown_ctr;
03627   if (t > 1) {
03628     v->vehstatus |= VS_TRAIN_SLOWING;
03629 
03630     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03631     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03632   } else {
03633     v->vehstatus &= ~VS_TRAIN_SLOWING;
03634   }
03635 
03636   if (!TrainCanLeaveTile(v)) return true;
03637 
03638   /* Determine the non-diagonal direction in which we will exit this tile */
03639   DiagDirection dir = TrainExitDir(v->direction, v->track);
03640   /* Calculate next tile */
03641   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03642 
03643   /* Determine the track status on the next tile */
03644   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03645   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03646 
03647   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03648   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03649 
03650   /* We are sure the train is not entering a depot, it is detected above */
03651 
03652   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03653   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03654   if (_settings_game.pf.forbid_90_deg) {
03655     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03656   }
03657 
03658   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03659   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03660     return TrainApproachingLineEnd(v, false, reverse);
03661   }
03662 
03663   /* approaching red signal */
03664   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03665 
03666   /* approaching a rail/road crossing? then make it red */
03667   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03668 
03669   return true;
03670 }
03671 
03672 
03673 static bool TrainLocoHandler(Train *v, bool mode)
03674 {
03675   /* train has crashed? */
03676   if (v->vehstatus & VS_CRASHED) {
03677     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03678   }
03679 
03680   if (v->force_proceed != TFP_NONE) {
03681     ClrBit(v->flags, VRF_TRAIN_STUCK);
03682     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03683   }
03684 
03685   /* train is broken down? */
03686   if (v->HandleBreakdown()) return true;
03687 
03688   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03689     ReverseTrainDirection(v);
03690   }
03691 
03692   /* exit if train is stopped */
03693   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03694 
03695   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03696   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03697     v->wait_counter = 0;
03698     v->cur_speed = 0;
03699     v->subspeed = 0;
03700     ClrBit(v->flags, VRF_LEAVING_STATION);
03701     ReverseTrainDirection(v);
03702     return true;
03703   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03704     /* Try to reserve a path when leaving the station as we
03705      * might not be marked as wanting a reservation, e.g.
03706      * when an overlength train gets turned around in a station. */
03707     DiagDirection dir = TrainExitDir(v->direction, v->track);
03708     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03709 
03710     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03711       TryPathReserve(v, true, true);
03712     }
03713     ClrBit(v->flags, VRF_LEAVING_STATION);
03714   }
03715 
03716   v->HandleLoading(mode);
03717 
03718   if (v->current_order.IsType(OT_LOADING)) return true;
03719 
03720   if (CheckTrainStayInDepot(v)) return true;
03721 
03722   if (!mode) v->ShowVisualEffect();
03723 
03724   /* We had no order but have an order now, do look ahead. */
03725   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03726     CheckNextTrainTile(v);
03727   }
03728 
03729   /* Handle stuck trains. */
03730   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03731     ++v->wait_counter;
03732 
03733     /* Should we try reversing this tick if still stuck? */
03734     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03735 
03736     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03737     if (!TryPathReserve(v)) {
03738       /* Still stuck. */
03739       if (turn_around) ReverseTrainDirection(v);
03740 
03741       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03742         /* Show message to player. */
03743         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03744           SetDParam(0, v->index);
03745           AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_STUCK, v->index);
03746         }
03747         v->wait_counter = 0;
03748       }
03749       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03750       if (v->force_proceed == TFP_NONE) return true;
03751       ClrBit(v->flags, VRF_TRAIN_STUCK);
03752       v->wait_counter = 0;
03753       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03754     }
03755   }
03756 
03757   if (v->current_order.IsType(OT_LEAVESTATION)) {
03758     v->current_order.Free();
03759     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03760     return true;
03761   }
03762 
03763   int j = v->UpdateSpeed();
03764 
03765   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03766   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03767     /* If we manually stopped, we're not force-proceeding anymore. */
03768     v->force_proceed = TFP_NONE;
03769     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03770   }
03771 
03772   int adv_spd = v->GetAdvanceDistance();
03773   if (j < adv_spd) {
03774     /* if the vehicle has speed 0, update the last_speed field. */
03775     if (v->cur_speed == 0) v->SetLastSpeed();
03776   } else {
03777     TrainCheckIfLineEnds(v);
03778     /* Loop until the train has finished moving. */
03779     for (;;) {
03780       j -= adv_spd;
03781       TrainController(v, NULL);
03782       /* Don't continue to move if the train crashed. */
03783       if (CheckTrainCollision(v)) break;
03784       /* Determine distance to next map position */
03785       adv_spd = v->GetAdvanceDistance();
03786 
03787       /* No more moving this tick */
03788       if (j < adv_spd || v->cur_speed == 0) break;
03789 
03790       OrderType order_type = v->current_order.GetType();
03791       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03792       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03793             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03794             IsTileType(v->tile, MP_STATION) &&
03795             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03796         ProcessOrders(v);
03797       }
03798     }
03799     v->SetLastSpeed();
03800   }
03801 
03802   for (Train *u = v; u != NULL; u = u->Next()) {
03803     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03804 
03805     u->UpdateViewport(false, false);
03806   }
03807 
03808   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03809 
03810   return true;
03811 }
03812 
03817 Money Train::GetRunningCost() const
03818 {
03819   Money cost = 0;
03820   const Train *v = this;
03821 
03822   do {
03823     const Engine *e = v->GetEngine();
03824     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03825 
03826     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03827     if (cost_factor == 0) continue;
03828 
03829     /* Halve running cost for multiheaded parts */
03830     if (v->IsMultiheaded()) cost_factor /= 2;
03831 
03832     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03833   } while ((v = v->GetNextVehicle()) != NULL);
03834 
03835   return cost;
03836 }
03837 
03842 bool Train::Tick()
03843 {
03844   this->tick_counter++;
03845 
03846   if (this->IsFrontEngine()) {
03847     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03848 
03849     this->current_order_time++;
03850 
03851     if (!TrainLocoHandler(this, false)) return false;
03852 
03853     return TrainLocoHandler(this, true);
03854   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03855     /* Delete flooded standalone wagon chain */
03856     if (++this->crash_anim_pos >= 4400) {
03857       delete this;
03858       return false;
03859     }
03860   }
03861 
03862   return true;
03863 }
03864 
03869 static void CheckIfTrainNeedsService(Train *v)
03870 {
03871   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03872   if (v->IsChainInDepot()) {
03873     VehicleServiceInDepot(v);
03874     return;
03875   }
03876 
03877   uint max_penalty;
03878   switch (_settings_game.pf.pathfinder_for_trains) {
03879     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03880     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03881     default: NOT_REACHED();
03882   }
03883 
03884   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03885   /* Only go to the depot if it is not too far out of our way. */
03886   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03887     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03888       /* If we were already heading for a depot but it has
03889        * suddenly moved farther away, we continue our normal
03890        * schedule? */
03891       v->current_order.MakeDummy();
03892       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03893     }
03894     return;
03895   }
03896 
03897   DepotID depot = GetDepotIndex(tfdd.tile);
03898 
03899   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03900       v->current_order.GetDestination() != depot &&
03901       !Chance16(3, 16)) {
03902     return;
03903   }
03904 
03905   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03906   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03907   v->dest_tile = tfdd.tile;
03908   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03909 }
03910 
03912 void Train::OnNewDay()
03913 {
03914   AgeVehicle(this);
03915 
03916   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03917 
03918   if (this->IsFrontEngine()) {
03919     CheckVehicleBreakdown(this);
03920 
03921     CheckIfTrainNeedsService(this);
03922 
03923     CheckOrders(this);
03924 
03925     /* update destination */
03926     if (this->current_order.IsType(OT_GOTO_STATION)) {
03927       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03928       if (tile != INVALID_TILE) this->dest_tile = tile;
03929     }
03930 
03931     if (this->running_ticks != 0) {
03932       /* running costs */
03933       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03934 
03935       this->profit_this_year -= cost.GetCost();
03936       this->running_ticks = 0;
03937 
03938       SubtractMoneyFromCompanyFract(this->owner, cost);
03939 
03940       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03941       SetWindowClassesDirty(WC_TRAINS_LIST);
03942     }
03943   }
03944 }
03945 
03950 Trackdir Train::GetVehicleTrackdir() const
03951 {
03952   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03953 
03954   if (this->track == TRACK_BIT_DEPOT) {
03955     /* We'll assume the train is facing outwards */
03956     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03957   }
03958 
03959   if (this->track == TRACK_BIT_WORMHOLE) {
03960     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03961     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03962   }
03963 
03964   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03965 }