train_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "gui.h"
00014 #include "articulated_vehicles.h"
00015 #include "command_func.h"
00016 #include "pathfinder/npf/npf_func.h"
00017 #include "pathfinder/yapf/yapf.hpp"
00018 #include "news_func.h"
00019 #include "company_func.h"
00020 #include "vehicle_gui.h"
00021 #include "newgrf_sound.h"
00022 #include "newgrf_text.h"
00023 #include "group.h"
00024 #include "strings_func.h"
00025 #include "viewport_func.h"
00026 #include "window_func.h"
00027 #include "vehicle_func.h"
00028 #include "sound_func.h"
00029 #include "ai/ai.hpp"
00030 #include "newgrf_station.h"
00031 #include "effectvehicle_func.h"
00032 #include "gamelog.h"
00033 #include "network/network.h"
00034 #include "spritecache.h"
00035 #include "core/random_func.hpp"
00036 #include "company_base.h"
00037 #include "newgrf.h"
00038 #include "order_backup.h"
00039 #include "cargodest_func.h"
00040 
00041 #include "table/strings.h"
00042 #include "table/train_cmd.h"
00043 
00044 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00045 static bool TrainCheckIfLineEnds(Train *v);
00046 static void TrainController(Train *v, Vehicle *nomove);
00047 static TileIndex TrainApproachingCrossingTile(const Train *v);
00048 static void CheckIfTrainNeedsService(Train *v);
00049 static void CheckNextTrainTile(Train *v);
00050 
00051 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00052 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00053 
00054 
00062 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00063 {
00064   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00065 
00066   DiagDirection diagdir = DirToDiagDir(direction);
00067 
00068   /* Determine the diagonal direction in which we will exit this tile */
00069   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00070     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00071   }
00072 
00073   return diagdir;
00074 }
00075 
00076 
00082 byte FreightWagonMult(CargoID cargo)
00083 {
00084   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00085   return _settings_game.vehicle.freight_trains;
00086 }
00087 
00093 static void RailVehicleLengthChanged(const Train *u)
00094 {
00095   /* show a warning once for each engine in whole game and once for each GRF after each game load */
00096   const Engine *engine = Engine::Get(u->engine_type);
00097   uint32 grfid = engine->grf_prop.grffile->grfid;
00098   GRFConfig *grfconfig = GetGRFConfig(grfid);
00099   if (GamelogGRFBugReverse(grfid, engine->grf_prop.local_id) || !HasBit(grfconfig->grf_bugs, GBUG_VEH_LENGTH)) {
00100     ShowNewGrfVehicleError(u->engine_type, STR_NEWGRF_BROKEN, STR_NEWGRF_BROKEN_VEHICLE_LENGTH, GBUG_VEH_LENGTH, true);
00101   }
00102 }
00103 
00105 void CheckTrainsLengths()
00106 {
00107   const Train *v;
00108   bool first = true;
00109 
00110   FOR_ALL_TRAINS(v) {
00111     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00112       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00113         if (u->track != TRACK_BIT_DEPOT) {
00114           if ((w->track != TRACK_BIT_DEPOT &&
00115               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->gcache.cached_veh_length) ||
00116               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00117             SetDParam(0, v->index);
00118             SetDParam(1, v->owner);
00119             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00120 
00121             if (!_networking && first) {
00122               first = false;
00123               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00124             }
00125             /* Break so we warn only once for each train. */
00126             break;
00127           }
00128         }
00129       }
00130     }
00131   }
00132 }
00133 
00138 void Train::RailtypeChanged()
00139 {
00140   for (Train *u = this; u != NULL; u = u->Next()) {
00141     /* The wagon-is-powered-state should not change, so the weight does not change. */
00142     u->UpdateVisualEffect(false);
00143   }
00144   this->PowerChanged();
00145   if (this->IsFrontEngine()) this->UpdateAcceleration();
00146 }
00147 
00154 void Train::ConsistChanged(bool same_length)
00155 {
00156   uint16 max_speed = UINT16_MAX;
00157 
00158   assert(this->IsFrontEngine() || this->IsFreeWagon());
00159 
00160   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00161   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00162   this->gcache.cached_total_length = 0;
00163   this->compatible_railtypes = RAILTYPES_NONE;
00164 
00165   bool train_can_tilt = true;
00166 
00167   for (Train *u = this; u != NULL; u = u->Next()) {
00168     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00169 
00170     /* Check the this->first cache. */
00171     assert(u->First() == this);
00172 
00173     /* update the 'first engine' */
00174     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00175     u->railtype = rvi_u->railtype;
00176 
00177     if (u->IsEngine()) first_engine = u->engine_type;
00178 
00179     /* Set user defined data to its default value */
00180     u->tcache.user_def_data = rvi_u->user_def_data;
00181     this->InvalidateNewGRFCache();
00182     u->InvalidateNewGRFCache();
00183   }
00184 
00185   for (Train *u = this; u != NULL; u = u->Next()) {
00186     /* Update user defined data (must be done before other properties) */
00187     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00188     this->InvalidateNewGRFCache();
00189     u->InvalidateNewGRFCache();
00190   }
00191 
00192   uint32 cargo_mask = 0;
00193 
00194   for (Train *u = this; u != NULL; u = u->Next()) {
00195     const Engine *e_u = Engine::Get(u->engine_type);
00196     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00197 
00198     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00199 
00200     /* Cache wagon override sprite group. NULL is returned if there is none */
00201     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00202 
00203     /* Reset colour map */
00204     u->colourmap = PAL_NONE;
00205 
00206     /* Update powered-wagon-status and visual effect */
00207     u->UpdateVisualEffect(true);
00208 
00209     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00210         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00211       /* wagon is powered */
00212       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00213     } else {
00214       ClrBit(u->flags, VRF_POWEREDWAGON);
00215     }
00216 
00217     if (!u->IsArticulatedPart()) {
00218       /* Do not count powered wagons for the compatible railtypes, as wagons always
00219          have railtype normal */
00220       if (rvi_u->power > 0) {
00221         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00222       }
00223 
00224       /* Some electric engines can be allowed to run on normal rail. It happens to all
00225        * existing electric engines when elrails are disabled and then re-enabled */
00226       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00227         u->railtype = RAILTYPE_RAIL;
00228         u->compatible_railtypes |= RAILTYPES_RAIL;
00229       }
00230 
00231       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00232       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00233         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00234         if (speed != 0) max_speed = min(speed, max_speed);
00235       }
00236     }
00237 
00238     /* Store carried cargo. */
00239     u->cargo_cap = GetVehicleCapacity(u);
00240     if (u->cargo_type != INVALID_CARGO && u->cargo_cap > 0) SetBit(cargo_mask, u->cargo_type);
00241 
00242     /* check the vehicle length (callback) */
00243     uint16 veh_len = CALLBACK_FAILED;
00244     if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00245       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00246     }
00247     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00248     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00249 
00250     /* verify length hasn't changed */
00251     if (same_length && veh_len != u->gcache.cached_veh_length) RailVehicleLengthChanged(u);
00252 
00253     /* update vehicle length? */
00254     if (!same_length) u->gcache.cached_veh_length = veh_len;
00255 
00256     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00257     this->InvalidateNewGRFCache();
00258     u->InvalidateNewGRFCache();
00259   }
00260 
00261   /* store consist weight/max speed in cache */
00262   this->vcache.cached_cargo_mask = cargo_mask;
00263   this->vcache.cached_max_speed = max_speed;
00264   this->tcache.cached_tilt = train_can_tilt;
00265   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00266 
00267   /* 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) */
00268   this->CargoChanged();
00269 
00270   if (this->IsFrontEngine()) {
00271     this->UpdateAcceleration();
00272     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00273     InvalidateWindowData(WC_VEHICLE_REFIT, this->index);
00274   }
00275 }
00276 
00287 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00288 {
00289   const Station *st = Station::Get(station_id);
00290   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00291   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00292 
00293   /* Default to the middle of the station for stations stops that are not in
00294    * the order list like intermediate stations when non-stop is disabled */
00295   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00296   if (v->gcache.cached_total_length >= *station_length) {
00297     /* The train is longer than the station, make it stop at the far end of the platform */
00298     osl = OSL_PLATFORM_FAR_END;
00299   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00300     osl = v->current_order.GetStopLocation();
00301   }
00302 
00303   /* The stop location of the FRONT! of the train */
00304   int stop;
00305   switch (osl) {
00306     default: NOT_REACHED();
00307 
00308     case OSL_PLATFORM_NEAR_END:
00309       stop = v->gcache.cached_total_length;
00310       break;
00311 
00312     case OSL_PLATFORM_MIDDLE:
00313       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00314       break;
00315 
00316     case OSL_PLATFORM_FAR_END:
00317       stop = *station_length;
00318       break;
00319   }
00320 
00321   /* Subtract half the front vehicle length of the train so we get the real
00322    * stop location of the train.
00323    * Actually, the center of all vehicles is half a normal vehicle's length
00324    * from the front of the vehicle, so even in case the vehicle is 1/8th
00325    * long, the center is still at 1/2 of VEHICLE_LENGTH. Basically FS#3569. */
00326   return stop - VEHICLE_LENGTH / 2;
00327 }
00328 
00329 
00334 int Train::GetCurveSpeedLimit() const
00335 {
00336   assert(this->First() == this);
00337 
00338   static const int absolute_max_speed = UINT16_MAX;
00339   int max_speed = absolute_max_speed;
00340 
00341   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00342 
00343   int curvecount[2] = {0, 0};
00344 
00345   /* first find the curve speed limit */
00346   int numcurve = 0;
00347   int sum = 0;
00348   int pos = 0;
00349   int lastpos = -1;
00350   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00351     Direction this_dir = u->direction;
00352     Direction next_dir = u->Next()->direction;
00353 
00354     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00355     if (dirdiff == DIRDIFF_SAME) continue;
00356 
00357     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00358     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00359     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00360       if (lastpos != -1) {
00361         numcurve++;
00362         sum += pos - lastpos;
00363         if (pos - lastpos == 1) {
00364           max_speed = 88;
00365         }
00366       }
00367       lastpos = pos;
00368     }
00369 
00370     /* if we have a 90 degree turn, fix the speed limit to 60 */
00371     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00372       max_speed = 61;
00373     }
00374   }
00375 
00376   if (numcurve > 0 && max_speed > 88) {
00377     if (curvecount[0] == 1 && curvecount[1] == 1) {
00378       max_speed = absolute_max_speed;
00379     } else {
00380       sum /= numcurve;
00381       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00382     }
00383   }
00384 
00385   if (max_speed != absolute_max_speed) {
00386     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00387     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00388     max_speed += (max_speed / 2) * rti->curve_speed;
00389 
00390     if (this->tcache.cached_tilt) {
00391       /* Apply max_speed bonus of 20% for a tilting train */
00392       max_speed += max_speed / 5;
00393     }
00394   }
00395 
00396   return max_speed;
00397 }
00398 
00403 int Train::GetCurrentMaxSpeed() const
00404 {
00405   int max_speed = this->tcache.cached_max_curve_speed;
00406   assert(max_speed == this->GetCurveSpeedLimit());
00407 
00408   if (IsRailStationTile(this->tile)) {
00409     StationID sid = GetStationIndex(this->tile);
00410     if (this->current_order.ShouldStopAtStation(this, sid)) {
00411       int station_ahead;
00412       int station_length;
00413       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00414 
00415       /* The distance to go is whatever is still ahead of the train minus the
00416        * distance from the train's stop location to the end of the platform */
00417       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00418 
00419       if (distance_to_go > 0) {
00420         int st_max_speed = 120;
00421 
00422         int delta_v = this->cur_speed / (distance_to_go + 1);
00423         if (max_speed > (this->cur_speed - delta_v)) {
00424           st_max_speed = this->cur_speed - (delta_v / 10);
00425         }
00426 
00427         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00428         max_speed = min(max_speed, st_max_speed);
00429       }
00430     }
00431   }
00432 
00433   for (const Train *u = this; u != NULL; u = u->Next()) {
00434     if (u->track == TRACK_BIT_DEPOT) {
00435       max_speed = min(max_speed, 61);
00436       break;
00437     }
00438   }
00439 
00440   return min(max_speed, this->gcache.cached_max_track_speed);
00441 }
00442 
00443 void Train::UpdateAcceleration()
00444 {
00445   assert(this->IsFrontEngine());
00446 
00447   uint power = this->gcache.cached_power;
00448   uint weight = this->gcache.cached_weight;
00449   assert(weight != 0);
00450   this->acceleration = Clamp(power / weight * 4, 1, 255);
00451 }
00452 
00458 int Train::GetDisplayImageWidth(Point *offset) const
00459 {
00460   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00461   int vehicle_pitch = 0;
00462 
00463   const Engine *e = Engine::Get(this->engine_type);
00464   if (e->grf_prop.grffile != NULL && is_custom_sprite(e->u.rail.image_index)) {
00465     reference_width = e->grf_prop.grffile->traininfo_vehicle_width;
00466     vehicle_pitch = e->grf_prop.grffile->traininfo_vehicle_pitch;
00467   }
00468 
00469   if (offset != NULL) {
00470     offset->x = reference_width / 2;
00471     offset->y = vehicle_pitch;
00472   }
00473   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00474 }
00475 
00476 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00477 {
00478   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00479 }
00480 
00481 SpriteID Train::GetImage(Direction direction) const
00482 {
00483   uint8 spritenum = this->spritenum;
00484   SpriteID sprite;
00485 
00486   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00487 
00488   if (is_custom_sprite(spritenum)) {
00489     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)));
00490     if (sprite != 0) return sprite;
00491 
00492     spritenum = Engine::Get(this->engine_type)->original_image_index;
00493   }
00494 
00495   sprite = GetDefaultTrainSprite(spritenum, direction);
00496 
00497   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00498 
00499   return sprite;
00500 }
00501 
00502 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y)
00503 {
00504   const Engine *e = Engine::Get(engine);
00505   Direction dir = rear_head ? DIR_E : DIR_W;
00506   uint8 spritenum = e->u.rail.image_index;
00507 
00508   if (is_custom_sprite(spritenum)) {
00509     SpriteID sprite = GetCustomVehicleIcon(engine, dir);
00510     if (sprite != 0) {
00511       if (e->grf_prop.grffile != NULL) {
00512         y += e->grf_prop.grffile->traininfo_vehicle_pitch;
00513       }
00514       return sprite;
00515     }
00516 
00517     spritenum = Engine::Get(engine)->original_image_index;
00518   }
00519 
00520   if (rear_head) spritenum++;
00521 
00522   return GetDefaultTrainSprite(spritenum, DIR_W);
00523 }
00524 
00525 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal)
00526 {
00527   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00528     int yf = y;
00529     int yr = y;
00530 
00531     SpriteID spritef = GetRailIcon(engine, false, yf);
00532     SpriteID spriter = GetRailIcon(engine, true, yr);
00533     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00534     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00535 
00536     preferred_x = Clamp(preferred_x, left - real_spritef->x_offs + 14, right - real_spriter->width - real_spriter->x_offs - 15);
00537 
00538     DrawSprite(spritef, pal, preferred_x - 14, yf);
00539     DrawSprite(spriter, pal, preferred_x + 15, yr);
00540   } else {
00541     SpriteID sprite = GetRailIcon(engine, false, y);
00542     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00543     preferred_x = Clamp(preferred_x, left - real_sprite->x_offs, right - real_sprite->width - real_sprite->x_offs);
00544     DrawSprite(sprite, pal, preferred_x, y);
00545   }
00546 }
00547 
00556 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00557 {
00558   const RailVehicleInfo *rvi = &e->u.rail;
00559 
00560   /* Check that the wagon can drive on the track in question */
00561   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00562 
00563   if (flags & DC_EXEC) {
00564     Train *v = new Train();
00565     *ret = v;
00566     v->spritenum = rvi->image_index;
00567 
00568     v->engine_type = e->index;
00569     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00570 
00571     DiagDirection dir = GetRailDepotDirection(tile);
00572 
00573     v->direction = DiagDirToDir(dir);
00574     v->tile = tile;
00575 
00576     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00577     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00578 
00579     v->x_pos = x;
00580     v->y_pos = y;
00581     v->z_pos = GetSlopeZ(x, y);
00582     v->owner = _current_company;
00583     v->track = TRACK_BIT_DEPOT;
00584     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00585 
00586     v->SetWagon();
00587 
00588     v->SetFreeWagon();
00589     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00590 
00591     v->cargo_type = e->GetDefaultCargoType();
00592     v->cargo_cap = rvi->capacity;
00593 
00594     v->railtype = rvi->railtype;
00595 
00596     v->build_year = _cur_year;
00597     v->cur_image = SPR_IMG_QUERY;
00598     v->random_bits = VehicleRandomBits();
00599 
00600     v->group_id = DEFAULT_GROUP;
00601 
00602     AddArticulatedParts(v);
00603 
00604     _new_vehicle_id = v->index;
00605 
00606     VehicleMove(v, false);
00607     v->First()->ConsistChanged(false);
00608     UpdateTrainGroupID(v->First());
00609 
00610     CheckConsistencyOfArticulatedVehicle(v);
00611 
00612     /* Try to connect the vehicle to one of free chains of wagons. */
00613     Train *w;
00614     FOR_ALL_TRAINS(w) {
00615       if (w->tile == tile &&              
00616           w->IsFreeWagon() &&             
00617           w->engine_type == e->index &&   
00618           w->First() != v &&              
00619           !(w->vehstatus & VS_CRASHED)) { 
00620         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00621         break;
00622       }
00623     }
00624   }
00625 
00626   return CommandCost();
00627 }
00628 
00630 static void NormalizeTrainVehInDepot(const Train *u)
00631 {
00632   const Train *v;
00633   FOR_ALL_TRAINS(v) {
00634     if (v->IsFreeWagon() && v->tile == u->tile &&
00635         v->track == TRACK_BIT_DEPOT) {
00636       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00637           CMD_MOVE_RAIL_VEHICLE).Failed())
00638         break;
00639     }
00640   }
00641 }
00642 
00643 static void AddRearEngineToMultiheadedTrain(Train *v)
00644 {
00645   Train *u = new Train();
00646   v->value >>= 1;
00647   u->value = v->value;
00648   u->direction = v->direction;
00649   u->owner = v->owner;
00650   u->tile = v->tile;
00651   u->x_pos = v->x_pos;
00652   u->y_pos = v->y_pos;
00653   u->z_pos = v->z_pos;
00654   u->track = TRACK_BIT_DEPOT;
00655   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00656   u->spritenum = v->spritenum + 1;
00657   u->cargo_type = v->cargo_type;
00658   u->cargo_subtype = v->cargo_subtype;
00659   u->cargo_cap = v->cargo_cap;
00660   u->railtype = v->railtype;
00661   u->engine_type = v->engine_type;
00662   u->build_year = v->build_year;
00663   u->cur_image = SPR_IMG_QUERY;
00664   u->random_bits = VehicleRandomBits();
00665   v->SetMultiheaded();
00666   u->SetMultiheaded();
00667   v->SetNext(u);
00668   VehicleMove(u, false);
00669 
00670   /* Now we need to link the front and rear engines together */
00671   v->other_multiheaded_part = u;
00672   u->other_multiheaded_part = v;
00673 }
00674 
00684 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00685 {
00686   const RailVehicleInfo *rvi = &e->u.rail;
00687 
00688   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00689 
00690   /* Check if depot and new engine uses the same kind of tracks *
00691    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00692   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00693 
00694   if (flags & DC_EXEC) {
00695     DiagDirection dir = GetRailDepotDirection(tile);
00696     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00697     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00698 
00699     Train *v = new Train();
00700     *ret = v;
00701     v->direction = DiagDirToDir(dir);
00702     v->tile = tile;
00703     v->owner = _current_company;
00704     v->x_pos = x;
00705     v->y_pos = y;
00706     v->z_pos = GetSlopeZ(x, y);
00707     v->track = TRACK_BIT_DEPOT;
00708     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00709     v->spritenum = rvi->image_index;
00710     v->cargo_type = e->GetDefaultCargoType();
00711     v->cargo_cap = rvi->capacity;
00712     v->last_station_visited = INVALID_STATION;
00713 
00714     v->engine_type = e->index;
00715     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00716 
00717     v->reliability = e->reliability;
00718     v->reliability_spd_dec = e->reliability_spd_dec;
00719     v->max_age = e->GetLifeLengthInDays();
00720 
00721     v->railtype = rvi->railtype;
00722     _new_vehicle_id = v->index;
00723 
00724     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00725     v->date_of_last_service = _date;
00726     v->build_year = _cur_year;
00727     v->cur_image = SPR_IMG_QUERY;
00728     v->random_bits = VehicleRandomBits();
00729 
00730     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00731 
00732     v->group_id = DEFAULT_GROUP;
00733 
00734     v->SetFrontEngine();
00735     v->SetEngine();
00736 
00737     VehicleMove(v, false);
00738 
00739     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00740       AddRearEngineToMultiheadedTrain(v);
00741     } else {
00742       AddArticulatedParts(v);
00743     }
00744 
00745     v->ConsistChanged(false);
00746     UpdateTrainGroupID(v);
00747 
00748     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00749       NormalizeTrainVehInDepot(v);
00750     }
00751 
00752     CheckConsistencyOfArticulatedVehicle(v);
00753   }
00754 
00755   return CommandCost();
00756 }
00757 
00758 
00759 bool Train::IsInDepot() const
00760 {
00761   /* Is the front engine stationary in the depot? */
00762   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00763 
00764   /* Check whether the rest is also already trying to enter the depot. */
00765   for (const Train *v = this; v != NULL; v = v->Next()) {
00766     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00767   }
00768 
00769   return true;
00770 }
00771 
00772 bool Train::IsStoppedInDepot() const
00773 {
00774   /* Are we stopped? Of course wagons don't really care... */
00775   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00776   return this->IsInDepot();
00777 }
00778 
00779 static Train *FindGoodVehiclePos(const Train *src)
00780 {
00781   EngineID eng = src->engine_type;
00782   TileIndex tile = src->tile;
00783 
00784   Train *dst;
00785   FOR_ALL_TRAINS(dst) {
00786     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00787       /* check so all vehicles in the line have the same engine. */
00788       Train *t = dst;
00789       while (t->engine_type == eng) {
00790         t = t->Next();
00791         if (t == NULL) return dst;
00792       }
00793     }
00794   }
00795 
00796   return NULL;
00797 }
00798 
00800 typedef SmallVector<Train *, 16> TrainList;
00801 
00807 static void MakeTrainBackup(TrainList &list, Train *t)
00808 {
00809   for (; t != NULL; t = t->Next()) *list.Append() = t;
00810 }
00811 
00816 static void RestoreTrainBackup(TrainList &list)
00817 {
00818   /* No train, nothing to do. */
00819   if (list.Length() == 0) return;
00820 
00821   Train *prev = NULL;
00822   /* Iterate over the list and rebuild it. */
00823   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00824     Train *t = *iter;
00825     if (prev != NULL) {
00826       prev->SetNext(t);
00827     } else if (t->Previous() != NULL) {
00828       /* Make sure the head of the train is always the first in the chain. */
00829       t->Previous()->SetNext(NULL);
00830     }
00831     prev = t;
00832   }
00833 }
00834 
00840 static void RemoveFromConsist(Train *part, bool chain = false)
00841 {
00842   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00843 
00844   /* Unlink at the front, but make it point to the next
00845    * vehicle after the to be remove part. */
00846   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00847 
00848   /* Unlink at the back */
00849   tail->SetNext(NULL);
00850 }
00851 
00857 static void InsertInConsist(Train *dst, Train *chain)
00858 {
00859   /* We do not want to add something in the middle of an articulated part. */
00860   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00861 
00862   chain->Last()->SetNext(dst->Next());
00863   dst->SetNext(chain);
00864 }
00865 
00871 static void NormaliseDualHeads(Train *t)
00872 {
00873   for (; t != NULL; t = t->GetNextVehicle()) {
00874     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00875 
00876     /* Make sure that there are no free cars before next engine */
00877     Train *u;
00878     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00879 
00880     if (u == t->other_multiheaded_part) continue;
00881 
00882     /* Remove the part from the 'wrong' train */
00883     RemoveFromConsist(t->other_multiheaded_part);
00884     /* And add it to the 'right' train */
00885     InsertInConsist(u, t->other_multiheaded_part);
00886   }
00887 }
00888 
00893 static void NormaliseSubtypes(Train *chain)
00894 {
00895   /* Nothing to do */
00896   if (chain == NULL) return;
00897 
00898   /* We must be the first in the chain. */
00899   assert(chain->Previous() == NULL);
00900 
00901   /* Set the appropriate bits for the first in the chain. */
00902   if (chain->IsWagon()) {
00903     chain->SetFreeWagon();
00904   } else {
00905     assert(chain->IsEngine());
00906     chain->SetFrontEngine();
00907   }
00908 
00909   /* Now clear the bits for the rest of the chain */
00910   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00911     t->ClearFreeWagon();
00912     t->ClearFrontEngine();
00913   }
00914 }
00915 
00925 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00926 {
00927   /* Just add 'new' engines and subtract the original ones.
00928    * If that's less than or equal to 0 we can be sure we did
00929    * not add any engines (read: trains) along the way. */
00930   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00931       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00932       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00933       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00934     return CommandCost();
00935   }
00936 
00937   /* Get a free unit number and check whether it's within the bounds.
00938    * There will always be a maximum of one new train. */
00939   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00940 
00941   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00942 }
00943 
00949 static CommandCost CheckTrainAttachment(Train *t)
00950 {
00951   /* No multi-part train, no need to check. */
00952   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00953 
00954   /* The maximum length for a train. For each part we decrease this by one
00955    * and if the result is negative the train is simply too long. */
00956   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00957 
00958   Train *head = t;
00959   Train *prev = t;
00960 
00961   /* Break the prev -> t link so it always holds within the loop. */
00962   t = t->Next();
00963   prev->SetNext(NULL);
00964 
00965   /* Make sure the cache is cleared. */
00966   head->InvalidateNewGRFCache();
00967 
00968   while (t != NULL) {
00969     allowed_len -= t->gcache.cached_veh_length;
00970 
00971     Train *next = t->Next();
00972 
00973     /* Unlink the to-be-added piece; it is already unlinked from the previous
00974      * part due to the fact that the prev -> t link is broken. */
00975     t->SetNext(NULL);
00976 
00977     /* Don't check callback for articulated or rear dual headed parts */
00978     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00979       /* Back up and clear the first_engine data to avoid using wagon override group */
00980       EngineID first_engine = t->gcache.first_engine;
00981       t->gcache.first_engine = INVALID_ENGINE;
00982 
00983       /* We don't want the cache to interfere. head's cache is cleared before
00984        * the loop and after each callback does not need to be cleared here. */
00985       t->InvalidateNewGRFCache();
00986 
00987       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00988 
00989       /* Restore original first_engine data */
00990       t->gcache.first_engine = first_engine;
00991 
00992       /* We do not want to remember any cached variables from the test run */
00993       t->InvalidateNewGRFCache();
00994       head->InvalidateNewGRFCache();
00995 
00996       if (callback != CALLBACK_FAILED) {
00997         /* A failing callback means everything is okay */
00998         StringID error = STR_NULL;
00999 
01000         if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01001         if (callback  < 0xFD) error = GetGRFStringID(GetEngineGRFID(head->engine_type), 0xD000 + callback);
01002 
01003         if (error != STR_NULL) return_cmd_error(error);
01004       }
01005     }
01006 
01007     /* And link it to the new part. */
01008     prev->SetNext(t);
01009     prev = t;
01010     t = next;
01011   }
01012 
01013   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01014   return CommandCost();
01015 }
01016 
01027 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01028 {
01029   /* Check whether we may actually construct the trains. */
01030   CommandCost ret = CheckTrainAttachment(src);
01031   if (ret.Failed()) return ret;
01032   ret = CheckTrainAttachment(dst);
01033   if (ret.Failed()) return ret;
01034 
01035   /* Check whether we need to build a new train. */
01036   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01037 }
01038 
01047 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01048 {
01049   /* First determine the front of the two resulting trains */
01050   if (*src_head == *dst_head) {
01051     /* If we aren't moving part(s) to a new train, we are just moving the
01052      * front back and there is not destination head. */
01053     *dst_head = NULL;
01054   } else if (*dst_head == NULL) {
01055     /* If we are moving to a new train the head of the move train would become
01056      * the head of the new vehicle. */
01057     *dst_head = src;
01058   }
01059 
01060   if (src == *src_head) {
01061     /* If we are moving the front of a train then we are, in effect, creating
01062      * a new head for the train. Point to that. Unless we are moving the whole
01063      * train in which case there is not 'source' train anymore.
01064      * In case we are a multiheaded part we want the complete thing to come
01065      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01066      * that is followed by a rear multihead we do not want to include that. */
01067     *src_head = move_chain ? NULL :
01068         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01069   }
01070 
01071   /* Now it's just simply removing the part that we are going to move from the
01072    * source train and *if* the destination is a not a new train add the chain
01073    * at the destination location. */
01074   RemoveFromConsist(src, move_chain);
01075   if (*dst_head != src) InsertInConsist(dst, src);
01076 
01077   /* Now normalise the dual heads, that is move the dual heads around in such
01078    * a way that the head and rear of a dual head are in the same train */
01079   NormaliseDualHeads(*src_head);
01080   NormaliseDualHeads(*dst_head);
01081 }
01082 
01088 static void NormaliseTrainHead(Train *head)
01089 {
01090   /* Not much to do! */
01091   if (head == NULL) return;
01092 
01093   /* Tell the 'world' the train changed. */
01094   head->ConsistChanged(false);
01095   UpdateTrainGroupID(head);
01096 
01097   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01098   if (!head->IsFrontEngine()) return;
01099 
01100   PrefillRouteLinks(head);
01101 
01102   /* Update the refit button and window */
01103   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01104   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, VVW_WIDGET_REFIT_VEH);
01105 
01106   /* If we don't have a unit number yet, set one. */
01107   if (head->unitnumber != 0) return;
01108   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01109 }
01110 
01123 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01124 {
01125   VehicleID s = GB(p1, 0, 20);
01126   VehicleID d = GB(p2, 0, 20);
01127   bool move_chain = HasBit(p1, 20);
01128 
01129   Train *src = Train::GetIfValid(s);
01130   if (src == NULL) return CMD_ERROR;
01131 
01132   CommandCost ret = CheckOwnership(src->owner);
01133   if (ret.Failed()) return ret;
01134 
01135   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01136   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01137 
01138   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01139   Train *dst;
01140   if (d == INVALID_VEHICLE) {
01141     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01142   } else {
01143     dst = Train::GetIfValid(d);
01144     if (dst == NULL) return CMD_ERROR;
01145 
01146     CommandCost ret = CheckOwnership(dst->owner);
01147     if (ret.Failed()) return ret;
01148 
01149     /* Do not allow appending to crashed vehicles, too */
01150     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01151   }
01152 
01153   /* if an articulated part is being handled, deal with its parent vehicle */
01154   src = src->GetFirstEnginePart();
01155   if (dst != NULL) {
01156     dst = dst->GetFirstEnginePart();
01157   }
01158 
01159   /* don't move the same vehicle.. */
01160   if (src == dst) return CommandCost();
01161 
01162   /* locate the head of the two chains */
01163   Train *src_head = src->First();
01164   Train *dst_head;
01165   if (dst != NULL) {
01166     dst_head = dst->First();
01167     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01168     /* Now deal with articulated part of destination wagon */
01169     dst = dst->GetLastEnginePart();
01170   } else {
01171     dst_head = NULL;
01172   }
01173 
01174   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01175 
01176   /* When moving all wagons, we can't have the same src_head and dst_head */
01177   if (move_chain && src_head == dst_head) return CommandCost();
01178 
01179   /* When moving a multiheaded part to be place after itself, bail out. */
01180   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01181 
01182   /* Check if all vehicles in the source train are stopped inside a depot. */
01183   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01184 
01185   /* Check if all vehicles in the destination train are stopped inside a depot. */
01186   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01187 
01188   /* First make a backup of the order of the trains. That way we can do
01189    * whatever we want with the order and later on easily revert. */
01190   TrainList original_src;
01191   TrainList original_dst;
01192 
01193   MakeTrainBackup(original_src, src_head);
01194   MakeTrainBackup(original_dst, dst_head);
01195 
01196   /* Also make backup of the original heads as ArrangeTrains can change them.
01197    * For the destination head we do not care if it is the same as the source
01198    * head because in that case it's just a copy. */
01199   Train *original_src_head = src_head;
01200   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01201 
01202   /* (Re)arrange the trains in the wanted arrangement. */
01203   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01204 
01205   if ((flags & DC_AUTOREPLACE) == 0) {
01206     /* If the autoreplace flag is set we do not need to test for the validity
01207      * because we are going to revert the train to its original state. As we
01208      * assume the original state was correct autoreplace can skip this. */
01209     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01210     if (ret.Failed()) {
01211       /* Restore the train we had. */
01212       RestoreTrainBackup(original_src);
01213       RestoreTrainBackup(original_dst);
01214       return ret;
01215     }
01216   }
01217 
01218   /* do it? */
01219   if (flags & DC_EXEC) {
01220     /* First normalise the sub types of the chains. */
01221     NormaliseSubtypes(src_head);
01222     NormaliseSubtypes(dst_head);
01223 
01224     /* There are 14 different cases:
01225      *  1) front engine gets moved to a new train, it stays a front engine.
01226      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01227      *     b) the 'next' part is an engine that becomes a front engine.
01228      *     c) there is no 'next' part, nothing else happens
01229      *  2) front engine gets moved to another train, it is not a front engine anymore
01230      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01231      *     b) the 'next' part is an engine that becomes a front engine.
01232      *     c) there is no 'next' part, nothing else happens
01233      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01234      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01235      *     b) the 'next' part is an engine that becomes a front engine.
01236      *  4) free wagon gets moved
01237      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01238      *     b) the 'next' part is an engine that becomes a front engine.
01239      *     c) there is no 'next' part, nothing else happens
01240      *  5) non front engine gets moved and becomes a new train, nothing else happens
01241      *  6) non front engine gets moved within a train / to another train, nothing hapens
01242      *  7) wagon gets moved, nothing happens
01243      */
01244     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01245       /* Cases #2 and #3: the front engine gets trashed. */
01246       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01247       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01248       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01249       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01250       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01251 
01252       /* We are going to be moved to a different train, and
01253        * we were the front engine of the original train. */
01254       if (dst_head != NULL && dst_head != src && (src_head == NULL || !src_head->IsFrontEngine())) {
01255         DecreaseGroupNumVehicle(src->group_id);
01256       }
01257 
01258       /* The front engine is going to be moved later in the
01259        * current train, and it will not be a train anymore. */
01260       if (dst_head == NULL && !src_head->IsFrontEngine()) {
01261         DecreaseGroupNumVehicle(src->group_id);
01262       }
01263 
01264       /* Delete orders, group stuff and the unit number as we're not the
01265        * front of any vehicle anymore. */
01266       DeleteVehicleOrders(src);
01267       RemoveVehicleFromGroup(src);
01268       src->unitnumber = 0;
01269     }
01270 
01271     /* We were a front engine and we are becoming one for a different train.
01272      * Increase the group counter accordingly. */
01273     if (original_src_head == src && dst_head == src) {
01274       IncreaseGroupNumVehicle(src->group_id);
01275     }
01276 
01277     /* We weren't a front engine but are becoming one. So
01278      * we should be put in the default group. */
01279     if (original_src_head != src && dst_head == src) {
01280       SetTrainGroupID(src, DEFAULT_GROUP);
01281     }
01282 
01283     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01284     NormaliseTrainHead(src_head);
01285     NormaliseTrainHead(dst_head);
01286 
01287     /* We are undoubtedly changing something in the depot and train list. */
01288     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01289     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01290   } else {
01291     /* We don't want to execute what we're just tried. */
01292     RestoreTrainBackup(original_src);
01293     RestoreTrainBackup(original_dst);
01294   }
01295 
01296   return CommandCost();
01297 }
01298 
01310 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01311 {
01312   /* Check if we deleted a vehicle window */
01313   Window *w = NULL;
01314 
01315   /* Sell a chain of vehicles or not? */
01316   bool sell_chain = HasBit(data, 0);
01317 
01318   Train *v = Train::From(t)->GetFirstEnginePart();
01319   Train *first = v->First();
01320 
01321   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01322 
01323   /* First make a backup of the order of the train. That way we can do
01324    * whatever we want with the order and later on easily revert. */
01325   TrainList original;
01326   MakeTrainBackup(original, first);
01327 
01328   /* We need to keep track of the new head and the head of what we're going to sell. */
01329   Train *new_head = first;
01330   Train *sell_head = NULL;
01331 
01332   /* Split the train in the wanted way. */
01333   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01334 
01335   /* We don't need to validate the second train; it's going to be sold. */
01336   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01337   if (ret.Failed()) {
01338     /* Restore the train we had. */
01339     RestoreTrainBackup(original);
01340     return ret;
01341   }
01342 
01343   CommandCost cost(EXPENSES_NEW_VEHICLES);
01344   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01345 
01346   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01347     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01348   }
01349 
01350   /* do it? */
01351   if (flags & DC_EXEC) {
01352     /* First normalise the sub types of the chain. */
01353     NormaliseSubtypes(new_head);
01354 
01355     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01356       /* We are selling the front engine. In this case we want to
01357        * 'give' the order, unit number and such to the new head. */
01358       new_head->orders.list = first->orders.list;
01359       new_head->AddToShared(first);
01360       DeleteVehicleOrders(first);
01361 
01362       /* Copy other important data from the front engine */
01363       new_head->CopyVehicleConfigAndStatistics(first);
01364       IncreaseGroupNumVehicle(new_head->group_id);
01365 
01366       /* If we deleted a window then open a new one for the 'new' train */
01367       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01368     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01369       OrderBackup::Backup(v, user);
01370     }
01371 
01372     /* We need to update the information about the train. */
01373     NormaliseTrainHead(new_head);
01374 
01375     /* We are undoubtedly changing something in the depot and train list. */
01376     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01377     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01378 
01379     /* Actually delete the sold 'goods' */
01380     delete sell_head;
01381   } else {
01382     /* We don't want to execute what we're just tried. */
01383     RestoreTrainBackup(original);
01384   }
01385 
01386   return cost;
01387 }
01388 
01389 void Train::UpdateDeltaXY(Direction direction)
01390 {
01391 #define MKIT(a, b, c, d) ((a & 0xFF) << 24) | ((b & 0xFF) << 16) | ((c & 0xFF) << 8) | ((d & 0xFF) << 0)
01392   static const uint32 _delta_xy_table[8] = {
01393     MKIT(3, 3, -1, -1),
01394     MKIT(3, 7, -1, -3),
01395     MKIT(3, 3, -1, -1),
01396     MKIT(7, 3, -3, -1),
01397     MKIT(3, 3, -1, -1),
01398     MKIT(3, 7, -1, -3),
01399     MKIT(3, 3, -1, -1),
01400     MKIT(7, 3, -3, -1),
01401   };
01402 #undef MKIT
01403 
01404   uint32 x = _delta_xy_table[direction];
01405   this->x_offs        = GB(x,  0, 8);
01406   this->y_offs        = GB(x,  8, 8);
01407   this->x_extent      = GB(x, 16, 8);
01408   this->y_extent      = GB(x, 24, 8);
01409   this->z_extent      = 6;
01410 }
01411 
01413 static void MarkTrainAsStuck(Train *v)
01414 {
01415   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01416     /* It is the first time the problem occurred, set the "train stuck" flag. */
01417     SetBit(v->flags, VRF_TRAIN_STUCK);
01418 
01419     v->wait_counter = 0;
01420 
01421     /* Stop train */
01422     v->cur_speed = 0;
01423     v->subspeed = 0;
01424     v->SetLastSpeed();
01425 
01426     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01427   }
01428 }
01429 
01430 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01431 {
01432   uint16 flag1 = *swap_flag1;
01433   uint16 flag2 = *swap_flag2;
01434 
01435   /* Clear the flags */
01436   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01437   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01438   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01439   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01440 
01441   /* Reverse the rail-flags (if needed) */
01442   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01443     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01444   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01445     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01446   }
01447   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01448     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01449   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01450     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01451   }
01452 }
01453 
01458 static void UpdateStatusAfterSwap(Train *v)
01459 {
01460   /* Reverse the direction. */
01461   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01462 
01463   /* Call the proper EnterTile function unless we are in a wormhole. */
01464   if (v->track != TRACK_BIT_WORMHOLE) {
01465     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01466   } else {
01467     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01468      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01469      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01470      * when we shouldn't have. Check if this is the case. */
01471     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01472     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01473       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01474       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01475         /* We have just left the wormhole, possibly set the
01476          * "goingdown" bit. UpdateInclination() can be used
01477          * because we are at the border of the tile. */
01478         v->UpdateInclination(true, true);
01479         return;
01480       }
01481     }
01482   }
01483 
01484   v->UpdateViewport(true, true);
01485 }
01486 
01487 static void ReverseTrainSwapVeh(Train *v, int l, int r)
01488 {
01489   Train *a, *b;
01490 
01491   /* locate vehicles to swap */
01492   for (a = v; l != 0; l--) a = a->Next();
01493   for (b = v; r != 0; r--) b = b->Next();
01494 
01495   if (a != b) {
01496     /* swap the hidden bits */
01497     {
01498       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01499       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01500       a->vehstatus = tmp;
01501     }
01502 
01503     Swap(a->track, b->track);
01504     Swap(a->direction, b->direction);
01505     Swap(a->x_pos, b->x_pos);
01506     Swap(a->y_pos, b->y_pos);
01507     Swap(a->tile,  b->tile);
01508     Swap(a->z_pos, b->z_pos);
01509 
01510     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01511 
01512     UpdateStatusAfterSwap(a);
01513     UpdateStatusAfterSwap(b);
01514   } else {
01515     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01516      * This is a little bit redundant way, a->gv_flags will
01517      * be (re)set twice, but it reduces code duplication */
01518     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01519     UpdateStatusAfterSwap(a);
01520   }
01521 
01522   /* Update power of the train in case tiles were different rail type. */
01523   v->RailtypeChanged();
01524 }
01525 
01526 
01532 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01533 {
01534   return (v->type == VEH_TRAIN) ? v : NULL;
01535 }
01536 
01537 
01544 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01545 {
01546   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01547 
01548   Train *t = Train::From(v);
01549   if (!t->IsFrontEngine()) return NULL;
01550 
01551   TileIndex tile = *(TileIndex *)data;
01552 
01553   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01554 
01555   return t;
01556 }
01557 
01558 
01565 static bool TrainApproachingCrossing(TileIndex tile)
01566 {
01567   assert(IsLevelCrossingTile(tile));
01568 
01569   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01570   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01571 
01572   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01573 
01574   dir = ReverseDiagDir(dir);
01575   tile_from = tile + TileOffsByDiagDir(dir);
01576 
01577   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01578 }
01579 
01580 
01587 void UpdateLevelCrossing(TileIndex tile, bool sound)
01588 {
01589   assert(IsLevelCrossingTile(tile));
01590 
01591   /* train on crossing || train approaching crossing || reserved */
01592   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01593 
01594   if (new_state != IsCrossingBarred(tile)) {
01595     if (new_state && sound) {
01596       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01597     }
01598     SetCrossingBarred(tile, new_state);
01599     MarkTileDirtyByTile(tile);
01600   }
01601 }
01602 
01603 
01609 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01610 {
01611   if (!IsCrossingBarred(tile)) {
01612     BarCrossing(tile);
01613     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01614     MarkTileDirtyByTile(tile);
01615   }
01616 }
01617 
01618 
01624 static void AdvanceWagonsBeforeSwap(Train *v)
01625 {
01626   Train *base = v;
01627   Train *first = base; // first vehicle to move
01628   Train *last = v->Last(); // last vehicle to move
01629   uint length = CountVehiclesInChain(v);
01630 
01631   while (length > 2) {
01632     last = last->Previous();
01633     first = first->Next();
01634 
01635     int differential = base->gcache.cached_veh_length - last->gcache.cached_veh_length;
01636 
01637     /* do not update images now
01638      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01639     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01640 
01641     base = first; // == base->Next()
01642     length -= 2;
01643   }
01644 }
01645 
01646 
01652 static void AdvanceWagonsAfterSwap(Train *v)
01653 {
01654   /* first of all, fix the situation when the train was entering a depot */
01655   Train *dep = v; // last vehicle in front of just left depot
01656   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01657     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01658   }
01659 
01660   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01661 
01662   if (leave != NULL) {
01663     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01664     int d = TicksToLeaveDepot(dep);
01665 
01666     if (d <= 0) {
01667       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01668       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01669       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01670     }
01671   } else {
01672     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01673   }
01674 
01675   Train *base = v;
01676   Train *first = base; // first vehicle to move
01677   Train *last = v->Last(); // last vehicle to move
01678   uint length = CountVehiclesInChain(v);
01679 
01680   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01681    * they have already correct spacing, so we have to make sure they are moved how they should */
01682   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01683 
01684   while (length > 2) {
01685     /* we reached vehicle (originally) in front of a depot, stop now
01686      * (we would move wagons that are already moved with new wagon length). */
01687     if (base == dep) break;
01688 
01689     /* the last wagon was that one leaving a depot, so do not move it anymore */
01690     if (last == dep) nomove = true;
01691 
01692     last = last->Previous();
01693     first = first->Next();
01694 
01695     int differential = last->gcache.cached_veh_length - base->gcache.cached_veh_length;
01696 
01697     /* do not update images now */
01698     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01699 
01700     base = first; // == base->Next()
01701     length -= 2;
01702   }
01703 }
01704 
01705 
01706 static void ReverseTrainDirection(Train *v)
01707 {
01708   if (IsRailDepotTile(v->tile)) {
01709     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01710   }
01711 
01712   /* Clear path reservation in front if train is not stuck. */
01713   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01714 
01715   /* Check if we were approaching a rail/road-crossing */
01716   TileIndex crossing = TrainApproachingCrossingTile(v);
01717 
01718   /* count number of vehicles */
01719   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01720 
01721   AdvanceWagonsBeforeSwap(v);
01722 
01723   /* swap start<>end, start+1<>end-1, ... */
01724   int l = 0;
01725   do {
01726     ReverseTrainSwapVeh(v, l++, r--);
01727   } while (l <= r);
01728 
01729   AdvanceWagonsAfterSwap(v);
01730 
01731   if (IsRailDepotTile(v->tile)) {
01732     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01733   }
01734 
01735   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01736 
01737   ClrBit(v->flags, VRF_REVERSING);
01738 
01739   /* recalculate cached data */
01740   v->ConsistChanged(true);
01741 
01742   /* update all images */
01743   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01744 
01745   /* update crossing we were approaching */
01746   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01747 
01748   /* maybe we are approaching crossing now, after reversal */
01749   crossing = TrainApproachingCrossingTile(v);
01750   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01751 
01752   /* If we are inside a depot after reversing, don't bother with path reserving. */
01753   if (v->track == TRACK_BIT_DEPOT) {
01754     /* Can't be stuck here as inside a depot is always a safe tile. */
01755     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01756     ClrBit(v->flags, VRF_TRAIN_STUCK);
01757     return;
01758   }
01759 
01760   /* TrainExitDir does not always produce the desired dir for depots and
01761    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01762   DiagDirection dir = TrainExitDir(v->direction, v->track);
01763   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01764 
01765   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01766     /* If we are currently on a tile with conventional signals, we can't treat the
01767      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01768     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01769       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01770       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01771 
01772     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01773     if (TryPathReserve(v, false, first_tile_okay)) {
01774       /* Do a look-ahead now in case our current tile was already a safe tile. */
01775       CheckNextTrainTile(v);
01776     } else if (v->current_order.GetType() != OT_LOADING) {
01777       /* Do not wait for a way out when we're still loading */
01778       MarkTrainAsStuck(v);
01779     }
01780   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01781     /* A train not inside a PBS block can't be stuck. */
01782     ClrBit(v->flags, VRF_TRAIN_STUCK);
01783     v->wait_counter = 0;
01784   }
01785 }
01786 
01796 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01797 {
01798   Train *v = Train::GetIfValid(p1);
01799   if (v == NULL) return CMD_ERROR;
01800 
01801   CommandCost ret = CheckOwnership(v->owner);
01802   if (ret.Failed()) return ret;
01803 
01804   if (p2 != 0) {
01805     /* turn a single unit around */
01806 
01807     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01808       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01809     }
01810     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01811 
01812     Train *front = v->First();
01813     /* make sure the vehicle is stopped in the depot */
01814     if (!front->IsStoppedInDepot()) {
01815       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01816     }
01817 
01818     if (flags & DC_EXEC) {
01819       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01820 
01821       front->ConsistChanged(false);
01822       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01823       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01824       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01825       SetWindowClassesDirty(WC_TRAINS_LIST);
01826     }
01827   } else {
01828     /* turn the whole train around */
01829     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01830 
01831     if (flags & DC_EXEC) {
01832       /* Properly leave the station if we are loading and won't be loading anymore */
01833       if (v->current_order.IsType(OT_LOADING)) {
01834         const Vehicle *last = v;
01835         while (last->Next() != NULL) last = last->Next();
01836 
01837         /* not a station || different station --> leave the station */
01838         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01839           v->LeaveStation();
01840         }
01841       }
01842 
01843       /* We cancel any 'skip signal at dangers' here */
01844       v->force_proceed = TFP_NONE;
01845       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01846 
01847       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01848         ToggleBit(v->flags, VRF_REVERSING);
01849       } else {
01850         v->cur_speed = 0;
01851         v->SetLastSpeed();
01852         HideFillingPercent(&v->fill_percent_te_id);
01853         ReverseTrainDirection(v);
01854       }
01855     }
01856   }
01857   return CommandCost();
01858 }
01859 
01869 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01870 {
01871   Train *t = Train::GetIfValid(p1);
01872   if (t == NULL) return CMD_ERROR;
01873 
01874   CommandCost ret = CheckOwnership(t->owner);
01875   if (ret.Failed()) return ret;
01876 
01877 
01878   if (flags & DC_EXEC) {
01879     /* If we are forced to proceed, cancel that order.
01880      * If we are marked stuck we would want to force the train
01881      * to proceed to the next signal. In the other cases we
01882      * would like to pass the signal at danger and run till the
01883      * next signal we encounter. */
01884     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01885     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01886   }
01887 
01888   return CommandCost();
01889 }
01890 
01895 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01896 {
01897   assert(!(v->vehstatus & VS_CRASHED));
01898 
01899   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01900 
01901   PBSTileInfo origin = FollowTrainReservation(v);
01902   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01903 
01904   switch (_settings_game.pf.pathfinder_for_trains) {
01905     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01906     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01907 
01908     default: NOT_REACHED();
01909   }
01910 }
01911 
01912 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01913 {
01914   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01915   if (tfdd.best_length == UINT_MAX) return false;
01916 
01917   if (location    != NULL) *location    = tfdd.tile;
01918   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01919   if (reverse     != NULL) *reverse     = tfdd.reverse;
01920 
01921   return true;
01922 }
01923 
01924 void Train::PlayLeaveStationSound() const
01925 {
01926   static const SoundFx sfx[] = {
01927     SND_04_TRAIN,
01928     SND_0A_TRAIN_HORN,
01929     SND_0A_TRAIN_HORN,
01930     SND_47_MAGLEV_2,
01931     SND_41_MAGLEV
01932   };
01933 
01934   if (PlayVehicleSound(this, VSE_START)) return;
01935 
01936   EngineID engtype = this->engine_type;
01937   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
01938 }
01939 
01941 static void CheckNextTrainTile(Train *v)
01942 {
01943   /* Don't do any look-ahead if path_backoff_interval is 255. */
01944   if (_settings_game.pf.path_backoff_interval == 255) return;
01945 
01946   /* Exit if we are inside a depot. */
01947   if (v->track == TRACK_BIT_DEPOT) return;
01948 
01949   switch (v->current_order.GetType()) {
01950     /* Exit if we reached our destination depot. */
01951     case OT_GOTO_DEPOT:
01952       if (v->tile == v->dest_tile) return;
01953       break;
01954 
01955     case OT_GOTO_WAYPOINT:
01956       /* If we reached our waypoint, make sure we see that. */
01957       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
01958       break;
01959 
01960     case OT_NOTHING:
01961     case OT_LEAVESTATION:
01962     case OT_LOADING:
01963       /* Exit if the current order doesn't have a destination, but the train has orders. */
01964       if (v->GetNumOrders() > 0) return;
01965       break;
01966 
01967     default:
01968       break;
01969   }
01970   /* Exit if we are on a station tile and are going to stop. */
01971   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
01972 
01973   Trackdir td = v->GetVehicleTrackdir();
01974 
01975   /* On a tile with a red non-pbs signal, don't look ahead. */
01976   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
01977       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
01978       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
01979 
01980   CFollowTrackRail ft(v);
01981   if (!ft.Follow(v->tile, td)) return;
01982 
01983   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
01984     /* Next tile is not reserved. */
01985     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
01986       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
01987         /* If the next tile is a PBS signal, try to make a reservation. */
01988         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
01989         if (_settings_game.pf.forbid_90_deg) {
01990           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
01991         }
01992         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
01993       }
01994     }
01995   }
01996 }
01997 
01998 static bool CheckTrainStayInDepot(Train *v)
01999 {
02000   /* bail out if not all wagons are in the same depot or not in a depot at all */
02001   for (const Train *u = v; u != NULL; u = u->Next()) {
02002     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02003   }
02004 
02005   /* if the train got no power, then keep it in the depot */
02006   if (v->gcache.cached_power == 0) {
02007     v->vehstatus |= VS_STOPPED;
02008     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02009     return true;
02010   }
02011 
02012   SigSegState seg_state;
02013 
02014   if (v->force_proceed == TFP_NONE) {
02015     /* force proceed was not pressed */
02016     if (++v->wait_counter < 37) {
02017       SetWindowClassesDirty(WC_TRAINS_LIST);
02018       return true;
02019     }
02020 
02021     v->wait_counter = 0;
02022 
02023     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02024     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02025       /* Full and no PBS signal in block or depot reserved, can't exit. */
02026       SetWindowClassesDirty(WC_TRAINS_LIST);
02027       return true;
02028     }
02029   } else {
02030     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02031   }
02032 
02033   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02034   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02035     /* We need to have a reservation for this to work. */
02036     if (HasDepotReservation(v->tile)) return true;
02037     SetDepotReservation(v->tile, true);
02038     VehicleEnterDepot(v);
02039     return true;
02040   }
02041 
02042   /* Only leave when we can reserve a path to our destination. */
02043   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02044     /* No path and no force proceed. */
02045     SetWindowClassesDirty(WC_TRAINS_LIST);
02046     MarkTrainAsStuck(v);
02047     return true;
02048   }
02049 
02050   SetDepotReservation(v->tile, true);
02051   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02052 
02053   VehicleServiceInDepot(v);
02054   SetWindowClassesDirty(WC_TRAINS_LIST);
02055   v->PlayLeaveStationSound();
02056 
02057   v->track = TRACK_BIT_X;
02058   if (v->direction & 2) v->track = TRACK_BIT_Y;
02059 
02060   v->vehstatus &= ~VS_HIDDEN;
02061   v->cur_speed = 0;
02062 
02063   v->UpdateDeltaXY(v->direction);
02064   v->cur_image = v->GetImage(v->direction);
02065   VehicleMove(v, false);
02066   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02067   v->UpdateAcceleration();
02068   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02069 
02070   return false;
02071 }
02072 
02074 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02075 {
02076   DiagDirection dir = TrackdirToExitdir(track_dir);
02077 
02078   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02079     /* Are we just leaving a tunnel/bridge? */
02080     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02081       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02082 
02083       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02084         /* Free the reservation only if no other train is on the tiles. */
02085         SetTunnelBridgeReservation(tile, false);
02086         SetTunnelBridgeReservation(end, false);
02087 
02088         if (_settings_client.gui.show_track_reservation) {
02089           MarkTileDirtyByTile(tile);
02090           MarkTileDirtyByTile(end);
02091         }
02092       }
02093     }
02094   } else if (IsRailStationTile(tile)) {
02095     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02096     /* If the new tile is not a further tile of the same station, we
02097      * clear the reservation for the whole platform. */
02098     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02099       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02100     }
02101   } else {
02102     /* Any other tile */
02103     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02104   }
02105 }
02106 
02108 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02109 {
02110   assert(v->IsFrontEngine());
02111 
02112   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02113   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02114   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02115   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02116 
02117   /* Don't free reservation if it's not ours. */
02118   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02119 
02120   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02121   while (ft.Follow(tile, td)) {
02122     tile = ft.m_new_tile;
02123     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02124     td = RemoveFirstTrackdir(&bits);
02125     assert(bits == TRACKDIR_BIT_NONE);
02126 
02127     if (!IsValidTrackdir(td)) break;
02128 
02129     if (IsTileType(tile, MP_RAILWAY)) {
02130       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02131         /* Conventional signal along trackdir: remove reservation and stop. */
02132         UnreserveRailTrack(tile, TrackdirToTrack(td));
02133         break;
02134       }
02135       if (HasPbsSignalOnTrackdir(tile, td)) {
02136         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02137           /* Red PBS signal? Can't be our reservation, would be green then. */
02138           break;
02139         } else {
02140           /* Turn the signal back to red. */
02141           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02142           MarkTileDirtyByTile(tile);
02143         }
02144       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02145         break;
02146       }
02147     }
02148 
02149     /* Don't free first station/bridge/tunnel if we are on it. */
02150     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);
02151 
02152     free_tile = true;
02153   }
02154 }
02155 
02156 static const byte _initial_tile_subcoord[6][4][3] = {
02157 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02158 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02159 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02160 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02161 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02162 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02163 };
02164 
02177 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02178 {
02179   switch (_settings_game.pf.pathfinder_for_trains) {
02180     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02181     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02182 
02183     default: NOT_REACHED();
02184   }
02185 }
02186 
02192 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02193 {
02194   PBSTileInfo origin = FollowTrainReservation(v);
02195 
02196   CFollowTrackRail ft(v);
02197 
02198   TileIndex tile = origin.tile;
02199   Trackdir  cur_td = origin.trackdir;
02200   while (ft.Follow(tile, cur_td)) {
02201     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02202       /* Possible signal tile. */
02203       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02204     }
02205 
02206     if (_settings_game.pf.forbid_90_deg) {
02207       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02208       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02209     }
02210 
02211     /* Station, depot or waypoint are a possible target. */
02212     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02213     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02214       /* Choice found or possible target encountered.
02215        * On finding a possible target, we need to stop and let the pathfinder handle the
02216        * remaining path. This is because we don't know if this target is in one of our
02217        * orders, so we might cause pathfinding to fail later on if we find a choice.
02218        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02219        * a wrong path not leading to our next destination. */
02220       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02221 
02222       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02223        * actually starts its search at the first unreserved tile. */
02224       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02225 
02226       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02227       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02228       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02229       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02230     }
02231 
02232     tile = ft.m_new_tile;
02233     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02234 
02235     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02236       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02237       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02238       /* Safe position is all good, path valid and okay. */
02239       return PBSTileInfo(tile, cur_td, true);
02240     }
02241 
02242     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02243   }
02244 
02245   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02246     /* End of line, path valid and okay. */
02247     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02248   }
02249 
02250   /* Sorry, can't reserve path, back out. */
02251   tile = origin.tile;
02252   cur_td = origin.trackdir;
02253   TileIndex stopped = ft.m_old_tile;
02254   Trackdir  stopped_td = ft.m_old_td;
02255   while (tile != stopped || cur_td != stopped_td) {
02256     if (!ft.Follow(tile, cur_td)) break;
02257 
02258     if (_settings_game.pf.forbid_90_deg) {
02259       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02260       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02261     }
02262     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02263 
02264     tile = ft.m_new_tile;
02265     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02266 
02267     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02268   }
02269 
02270   /* Path invalid. */
02271   return PBSTileInfo();
02272 }
02273 
02284 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02285 {
02286   switch (_settings_game.pf.pathfinder_for_trains) {
02287     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02288     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02289 
02290     default: NOT_REACHED();
02291   }
02292 }
02293 
02295 class VehicleOrderSaver
02296 {
02297 private:
02298   Train          *v;
02299   Order          old_order;
02300   TileIndex      old_dest_tile;
02301   StationID      old_last_station_visited;
02302   VehicleOrderID index;
02303   bool           suppress_automatic_orders;
02304 
02305 public:
02306   VehicleOrderSaver(Train *_v) :
02307     v(_v),
02308     old_order(_v->current_order),
02309     old_dest_tile(_v->dest_tile),
02310     old_last_station_visited(_v->last_station_visited),
02311     index(_v->cur_real_order_index),
02312     suppress_automatic_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_AUTOMATIC_ORDERS))
02313   {
02314   }
02315 
02316   ~VehicleOrderSaver()
02317   {
02318     this->v->current_order = this->old_order;
02319     this->v->dest_tile = this->old_dest_tile;
02320     this->v->last_station_visited = this->old_last_station_visited;
02321     SB(this->v->gv_flags, GVF_SUPPRESS_AUTOMATIC_ORDERS, 1, suppress_automatic_orders ? 1: 0);
02322   }
02323 
02329   bool SwitchToNextOrder(bool skip_first)
02330   {
02331     if (this->v->GetNumOrders() == 0) return false;
02332 
02333     if (skip_first) ++this->index;
02334 
02335     int conditional_depth = 0;
02336 
02337     do {
02338       /* Wrap around. */
02339       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02340 
02341       Order *order = this->v->GetOrder(this->index);
02342       assert(order != NULL);
02343 
02344       switch (order->GetType()) {
02345         case OT_GOTO_DEPOT:
02346           /* Skip service in depot orders when the train doesn't need service. */
02347           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02348         case OT_GOTO_STATION:
02349         case OT_GOTO_WAYPOINT:
02350           this->v->current_order = *order;
02351           UpdateOrderDest(this->v, order);
02352           return true;
02353         case OT_CONDITIONAL: {
02354           if (conditional_depth > this->v->GetNumOrders()) return false;
02355           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02356           if (next != INVALID_VEH_ORDER_ID) {
02357             conditional_depth++;
02358             this->index = next;
02359             /* Don't increment next, so no break here. */
02360             continue;
02361           }
02362           break;
02363         }
02364         default:
02365           break;
02366       }
02367       /* Don't increment inside the while because otherwise conditional
02368        * orders can lead to an infinite loop. */
02369       ++this->index;
02370     } while (this->index != this->v->cur_real_order_index);
02371 
02372     return false;
02373   }
02374 };
02375 
02376 /* choose a track */
02377 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02378 {
02379   Track best_track = INVALID_TRACK;
02380   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02381   bool changed_signal = false;
02382 
02383   assert((tracks & ~TRACK_BIT_MASK) == 0);
02384 
02385   if (got_reservation != NULL) *got_reservation = false;
02386 
02387   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02388   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02389   /* Do we have a suitable reserved track? */
02390   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02391 
02392   /* Quick return in case only one possible track is available */
02393   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02394     Track track = FindFirstTrack(tracks);
02395     /* We need to check for signals only here, as a junction tile can't have signals. */
02396     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02397       do_track_reservation = true;
02398       changed_signal = true;
02399       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02400     } else if (!do_track_reservation) {
02401       return track;
02402     }
02403     best_track = track;
02404   }
02405 
02406   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02407   DiagDirection dest_enterdir = enterdir;
02408   if (do_track_reservation) {
02409     /* Check if the train needs service here, so it has a chance to always find a depot.
02410      * Also check if the current order is a service order so we don't reserve a path to
02411      * the destination but instead to the next one if service isn't needed. */
02412     CheckIfTrainNeedsService(v);
02413     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02414 
02415     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02416     if (res_dest.tile == INVALID_TILE) {
02417       /* Reservation failed? */
02418       if (mark_stuck) MarkTrainAsStuck(v);
02419       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02420       return FindFirstTrack(tracks);
02421     }
02422   }
02423 
02424   /* Save the current train order. The destructor will restore the old order on function exit. */
02425   VehicleOrderSaver orders(v);
02426 
02427   /* If the current tile is the destination of the current order and
02428    * a reservation was requested, advance to the next order.
02429    * Don't advance on a depot order as depots are always safe end points
02430    * for a path and no look-ahead is necessary. This also avoids a
02431    * problem with depot orders not part of the order list when the
02432    * order list itself is empty. */
02433   if (v->current_order.IsType(OT_LEAVESTATION)) {
02434     orders.SwitchToNextOrder(false);
02435   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02436       v->current_order.IsType(OT_GOTO_STATION) ?
02437       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02438       v->tile == v->dest_tile))) {
02439     orders.SwitchToNextOrder(true);
02440   }
02441 
02442   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02443     /* Pathfinders are able to tell that route was only 'guessed'. */
02444     bool      path_found = true;
02445     TileIndex new_tile = res_dest.tile;
02446 
02447     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02448     if (new_tile == tile) best_track = next_track;
02449     v->HandlePathfindingResult(path_found);
02450   }
02451 
02452   /* No track reservation requested -> finished. */
02453   if (!do_track_reservation) return best_track;
02454 
02455   /* A path was found, but could not be reserved. */
02456   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02457     if (mark_stuck) MarkTrainAsStuck(v);
02458     FreeTrainTrackReservation(v);
02459     return best_track;
02460   }
02461 
02462   /* No possible reservation target found, we are probably lost. */
02463   if (res_dest.tile == INVALID_TILE) {
02464     /* Try to find any safe destination. */
02465     PBSTileInfo origin = FollowTrainReservation(v);
02466     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02467       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02468       best_track = FindFirstTrack(res);
02469       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02470       if (got_reservation != NULL) *got_reservation = true;
02471       if (changed_signal) MarkTileDirtyByTile(tile);
02472     } else {
02473       FreeTrainTrackReservation(v);
02474       if (mark_stuck) MarkTrainAsStuck(v);
02475     }
02476     return best_track;
02477   }
02478 
02479   if (got_reservation != NULL) *got_reservation = true;
02480 
02481   /* Reservation target found and free, check if it is safe. */
02482   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02483     /* Extend reservation until we have found a safe position. */
02484     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02485     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02486     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02487     if (_settings_game.pf.forbid_90_deg) {
02488       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02489     }
02490 
02491     /* Get next order with destination. */
02492     if (orders.SwitchToNextOrder(true)) {
02493       PBSTileInfo cur_dest;
02494       bool path_found;
02495       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02496       if (cur_dest.tile != INVALID_TILE) {
02497         res_dest = cur_dest;
02498         if (res_dest.okay) continue;
02499         /* Path found, but could not be reserved. */
02500         FreeTrainTrackReservation(v);
02501         if (mark_stuck) MarkTrainAsStuck(v);
02502         if (got_reservation != NULL) *got_reservation = false;
02503         changed_signal = false;
02504         break;
02505       }
02506     }
02507     /* No order or no safe position found, try any position. */
02508     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02509       FreeTrainTrackReservation(v);
02510       if (mark_stuck) MarkTrainAsStuck(v);
02511       if (got_reservation != NULL) *got_reservation = false;
02512       changed_signal = false;
02513     }
02514     break;
02515   }
02516 
02517   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02518 
02519   if (changed_signal) MarkTileDirtyByTile(tile);
02520 
02521   return best_track;
02522 }
02523 
02532 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02533 {
02534   assert(v->IsFrontEngine());
02535 
02536   /* We have to handle depots specially as the track follower won't look
02537    * at the depot tile itself but starts from the next tile. If we are still
02538    * inside the depot, a depot reservation can never be ours. */
02539   if (v->track == TRACK_BIT_DEPOT) {
02540     if (HasDepotReservation(v->tile)) {
02541       if (mark_as_stuck) MarkTrainAsStuck(v);
02542       return false;
02543     } else {
02544       /* Depot not reserved, but the next tile might be. */
02545       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02546       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02547     }
02548   }
02549 
02550   Vehicle *other_train = NULL;
02551   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02552   /* The path we are driving on is already blocked by some other train.
02553    * This can only happen in certain situations when mixing path and
02554    * block signals or when changing tracks and/or signals.
02555    * Exit here as doing any further reservations will probably just
02556    * make matters worse. */
02557   if (other_train != NULL && other_train->index != v->index) {
02558     if (mark_as_stuck) MarkTrainAsStuck(v);
02559     return false;
02560   }
02561   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02562   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02563     /* Can't be stuck then. */
02564     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
02565     ClrBit(v->flags, VRF_TRAIN_STUCK);
02566     return true;
02567   }
02568 
02569   /* If we are in a depot, tentatively reserve the depot. */
02570   if (v->track == TRACK_BIT_DEPOT) {
02571     SetDepotReservation(v->tile, true);
02572     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02573   }
02574 
02575   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02576   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02577   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02578 
02579   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02580 
02581   bool res_made = false;
02582   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02583 
02584   if (!res_made) {
02585     /* Free the depot reservation as well. */
02586     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02587     return false;
02588   }
02589 
02590   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02591     v->wait_counter = 0;
02592     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
02593   }
02594   ClrBit(v->flags, VRF_TRAIN_STUCK);
02595   return true;
02596 }
02597 
02598 
02599 static bool CheckReverseTrain(const Train *v)
02600 {
02601   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02602       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02603       !(v->direction & 1)) {
02604     return false;
02605   }
02606 
02607   assert(v->track != TRACK_BIT_NONE);
02608 
02609   switch (_settings_game.pf.pathfinder_for_trains) {
02610     case VPF_NPF: return NPFTrainCheckReverse(v);
02611     case VPF_YAPF: return YapfTrainCheckReverse(v);
02612 
02613     default: NOT_REACHED();
02614   }
02615 }
02616 
02617 TileIndex Train::GetOrderStationLocation(StationID station)
02618 {
02619   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02620 
02621   const Station *st = Station::Get(station);
02622   if (!(st->facilities & FACIL_TRAIN)) {
02623     /* The destination station has no trainstation tiles. */
02624     this->IncrementRealOrderIndex();
02625     return 0;
02626   }
02627 
02628   return st->xy;
02629 }
02630 
02631 void Train::MarkDirty()
02632 {
02633   Train *v = this;
02634   do {
02635     v->UpdateViewport(false, false);
02636   } while ((v = v->Next()) != NULL);
02637 
02638   /* need to update acceleration and cached values since the goods on the train changed. */
02639   this->CargoChanged();
02640   this->UpdateAcceleration();
02641 }
02642 
02650 int Train::UpdateSpeed()
02651 {
02652   switch (_settings_game.vehicle.train_acceleration_model) {
02653     default: NOT_REACHED();
02654     case AM_ORIGINAL:
02655       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, this->gcache.cached_max_track_speed);
02656 
02657     case AM_REALISTIC:
02658       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02659   }
02660 }
02661 
02667 static void TrainEnterStation(Train *v, StationID station)
02668 {
02669   /* check if a train ever visited this station before */
02670   Station *st = Station::Get(station);
02671   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02672     st->had_vehicle_of_type |= HVOT_TRAIN;
02673     SetDParam(0, st->index);
02674     AddVehicleNewsItem(
02675       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02676       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
02677       v->index,
02678       st->index
02679     );
02680     AI::NewEvent(v->owner, new AIEventStationFirstVehicle(st->index, v->index));
02681   }
02682 
02683   v->force_proceed = TFP_NONE;
02684   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02685 
02686   v->BeginLoading(station);
02687 
02688   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02689 }
02690 
02691 /* Check if the vehicle is compatible with the specified tile */
02692 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02693 {
02694   return IsTileOwner(tile, v->owner) &&
02695       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02696 }
02697 
02698 struct RailtypeSlowdownParams {
02699   byte small_turn, large_turn;
02700   byte z_up; // fraction to remove when moving up
02701   byte z_down; // fraction to remove when moving down
02702 };
02703 
02704 static const RailtypeSlowdownParams _railtype_slowdown[] = {
02705   /* normal accel */
02706   {256 / 4, 256 / 2, 256 / 4, 2}, 
02707   {256 / 4, 256 / 2, 256 / 4, 2}, 
02708   {256 / 4, 256 / 2, 256 / 4, 2}, 
02709   {0,       256 / 2, 256 / 4, 2}, 
02710 };
02711 
02713 static inline void AffectSpeedByZChange(Train *v, byte old_z)
02714 {
02715   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02716 
02717   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
02718 
02719   if (old_z < v->z_pos) {
02720     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
02721   } else {
02722     uint16 spd = v->cur_speed + rsp->z_down;
02723     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02724   }
02725 }
02726 
02727 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02728 {
02729   if (IsTileType(tile, MP_RAILWAY) &&
02730       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02731     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02732     Trackdir trackdir = FindFirstTrackdir(tracks);
02733     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02734       /* A PBS block with a non-PBS signal facing us? */
02735       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02736     }
02737   }
02738   return false;
02739 }
02740 
02744 void Train::ReserveTrackUnderConsist() const
02745 {
02746   for (const Train *u = this; u != NULL; u = u->Next()) {
02747     switch (u->track) {
02748       case TRACK_BIT_WORMHOLE:
02749         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02750         break;
02751       case TRACK_BIT_DEPOT:
02752         break;
02753       default:
02754         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02755         break;
02756     }
02757   }
02758 }
02759 
02760 uint Train::Crash(bool flooded)
02761 {
02762   uint pass = 0;
02763   if (this->IsFrontEngine()) {
02764     pass += 2; // driver
02765 
02766     /* Remove the reserved path in front of the train if it is not stuck.
02767      * Also clear all reserved tracks the train is currently on. */
02768     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02769     for (const Train *v = this; v != NULL; v = v->Next()) {
02770       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02771       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02772         /* ClearPathReservation will not free the wormhole exit
02773          * if the train has just entered the wormhole. */
02774         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02775       }
02776     }
02777 
02778     /* we may need to update crossing we were approaching,
02779      * but must be updated after the train has been marked crashed */
02780     TileIndex crossing = TrainApproachingCrossingTile(this);
02781     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02782 
02783     /* Remove the loading indicators (if any) */
02784     HideFillingPercent(&this->fill_percent_te_id);
02785   }
02786 
02787   pass += this->GroundVehicleBase::Crash(flooded);
02788 
02789   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02790   return pass;
02791 }
02792 
02799 static uint TrainCrashed(Train *v)
02800 {
02801   uint num = 0;
02802 
02803   /* do not crash train twice */
02804   if (!(v->vehstatus & VS_CRASHED)) {
02805     num = v->Crash();
02806     AI::NewEvent(v->owner, new AIEventVehicleCrashed(v->index, v->tile, AIEventVehicleCrashed::CRASH_TRAIN));
02807   }
02808 
02809   /* Try to re-reserve track under already crashed train too.
02810    * Crash() clears the reservation! */
02811   v->ReserveTrackUnderConsist();
02812 
02813   return num;
02814 }
02815 
02816 struct TrainCollideChecker {
02817   Train *v; 
02818   uint num; 
02819 };
02820 
02821 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02822 {
02823   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02824 
02825   /* not a train or in depot */
02826   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02827 
02828   /* do not crash into trains of another company. */
02829   if (v->owner != tcc->v->owner) return NULL;
02830 
02831   /* get first vehicle now to make most usual checks faster */
02832   Train *coll = Train::From(v)->First();
02833 
02834   /* can't collide with own wagons */
02835   if (coll == tcc->v) return NULL;
02836 
02837   int x_diff = v->x_pos - tcc->v->x_pos;
02838   int y_diff = v->y_pos - tcc->v->y_pos;
02839 
02840   /* Do fast calculation to check whether trains are not in close vicinity
02841    * and quickly reject trains distant enough for any collision.
02842    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02843    * Differences are then ORed and then we check for any higher bits */
02844   uint hash = (y_diff + 7) | (x_diff + 7);
02845   if (hash & ~15) return NULL;
02846 
02847   /* Slower check using multiplication */
02848   if (x_diff * x_diff + y_diff * y_diff > 25) return NULL;
02849 
02850   /* Happens when there is a train under bridge next to bridge head */
02851   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02852 
02853   /* crash both trains */
02854   tcc->num += TrainCrashed(tcc->v);
02855   tcc->num += TrainCrashed(coll);
02856 
02857   return NULL; // continue searching
02858 }
02859 
02866 static bool CheckTrainCollision(Train *v)
02867 {
02868   /* can't collide in depot */
02869   if (v->track == TRACK_BIT_DEPOT) return false;
02870 
02871   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
02872 
02873   TrainCollideChecker tcc;
02874   tcc.v = v;
02875   tcc.num = 0;
02876 
02877   /* find colliding vehicles */
02878   if (v->track == TRACK_BIT_WORMHOLE) {
02879     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
02880     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
02881   } else {
02882     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
02883   }
02884 
02885   /* any dead -> no crash */
02886   if (tcc.num == 0) return false;
02887 
02888   SetDParam(0, tcc.num);
02889   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH,
02890     NS_ACCIDENT,
02891     v->index
02892   );
02893 
02894   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
02895   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
02896   return true;
02897 }
02898 
02899 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
02900 {
02901   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
02902 
02903   Train *t = Train::From(v);
02904   DiagDirection exitdir = *(DiagDirection *)data;
02905 
02906   /* not front engine of a train, inside wormhole or depot, crashed */
02907   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
02908 
02909   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
02910 
02911   return t;
02912 }
02913 
02914 static void TrainController(Train *v, Vehicle *nomove)
02915 {
02916   Train *first = v->First();
02917   Train *prev;
02918   bool direction_changed = false; // has direction of any part changed?
02919 
02920   /* For every vehicle after and including the given vehicle */
02921   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
02922     DiagDirection enterdir = DIAGDIR_BEGIN;
02923     bool update_signals_crossing = false; // will we update signals or crossing state?
02924 
02925     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
02926     if (v->track != TRACK_BIT_WORMHOLE) {
02927       /* Not inside tunnel */
02928       if (gp.old_tile == gp.new_tile) {
02929         /* Staying in the old tile */
02930         if (v->track == TRACK_BIT_DEPOT) {
02931           /* Inside depot */
02932           gp.x = v->x_pos;
02933           gp.y = v->y_pos;
02934         } else {
02935           /* Not inside depot */
02936 
02937           /* Reverse when we are at the end of the track already, do not move to the new position */
02938           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v)) return;
02939 
02940           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
02941           if (HasBit(r, VETS_CANNOT_ENTER)) {
02942             goto invalid_rail;
02943           }
02944           if (HasBit(r, VETS_ENTERED_STATION)) {
02945             /* The new position is the end of the platform */
02946             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
02947           }
02948         }
02949       } else {
02950         /* A new tile is about to be entered. */
02951 
02952         /* Determine what direction we're entering the new tile from */
02953         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
02954         assert(IsValidDiagDirection(enterdir));
02955 
02956         /* Get the status of the tracks in the new tile and mask
02957          * away the bits that aren't reachable. */
02958         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
02959         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
02960 
02961         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
02962         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
02963 
02964         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
02965         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
02966           /* We allow wagons to make 90 deg turns, because forbid_90_deg
02967            * can be switched on halfway a turn */
02968           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
02969         }
02970 
02971         if (bits == TRACK_BIT_NONE) goto invalid_rail;
02972 
02973         /* Check if the new tile constrains tracks that are compatible
02974          * with the current train, if not, bail out. */
02975         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
02976 
02977         TrackBits chosen_track;
02978         if (prev == NULL) {
02979           /* Currently the locomotive is active. Determine which one of the
02980            * available tracks to choose */
02981           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
02982           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
02983 
02984           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
02985             /* For each signal we find decrease the counter by one.
02986              * We start at two, so the first signal we pass decreases
02987              * this to one, then if we reach the next signal it is
02988              * decreased to zero and we won't pass that new signal. */
02989             Trackdir dir = FindFirstTrackdir(trackdirbits);
02990             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
02991                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
02992               /* However, we do not want to be stopped by PBS signals
02993                * entered via the back. */
02994               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
02995               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02996             }
02997           }
02998 
02999           /* Check if it's a red signal and that force proceed is not clicked. */
03000           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03001             /* In front of a red signal */
03002             Trackdir i = FindFirstTrackdir(trackdirbits);
03003 
03004             /* Don't handle stuck trains here. */
03005             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return;
03006 
03007             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03008               v->cur_speed = 0;
03009               v->subspeed = 0;
03010               v->progress = 255 - 100;
03011               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return;
03012             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03013               v->cur_speed = 0;
03014               v->subspeed = 0;
03015               v->progress = 255 - 10;
03016               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03017                 DiagDirection exitdir = TrackdirToExitdir(i);
03018                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03019 
03020                 exitdir = ReverseDiagDir(exitdir);
03021 
03022                 /* check if a train is waiting on the other side */
03023                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return;
03024               }
03025             }
03026 
03027             /* If we would reverse but are currently in a PBS block and
03028              * reversing of stuck trains is disabled, don't reverse.
03029              * This does not apply if the reason for reversing is a one-way
03030              * signal blocking us, because a train would then be stuck forever. */
03031             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03032                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03033               v->wait_counter = 0;
03034               return;
03035             }
03036             goto reverse_train_direction;
03037           } else {
03038             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03039           }
03040         } else {
03041           /* The wagon is active, simply follow the prev vehicle. */
03042           if (prev->tile == gp.new_tile) {
03043             /* Choose the same track as prev */
03044             if (prev->track == TRACK_BIT_WORMHOLE) {
03045               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03046                * However, just choose the track into the wormhole. */
03047               assert(IsTunnel(prev->tile));
03048               chosen_track = bits;
03049             } else {
03050               chosen_track = prev->track;
03051             }
03052           } else {
03053             /* Choose the track that leads to the tile where prev is.
03054              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03055              * I.e. when the tile between them has only space for a single vehicle like
03056              *  1) horizontal/vertical track tiles and
03057              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03058              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03059              */
03060             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03061               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03062               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03063               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03064               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03065             };
03066             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03067             assert(IsValidDiagDirection(exitdir));
03068             chosen_track = _connecting_track[enterdir][exitdir];
03069           }
03070           chosen_track &= bits;
03071         }
03072 
03073         /* Make sure chosen track is a valid track */
03074         assert(
03075             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03076             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03077             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03078 
03079         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03080         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03081         gp.x = (gp.x & ~0xF) | b[0];
03082         gp.y = (gp.y & ~0xF) | b[1];
03083         Direction chosen_dir = (Direction)b[2];
03084 
03085         /* Call the landscape function and tell it that the vehicle entered the tile */
03086         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03087         if (HasBit(r, VETS_CANNOT_ENTER)) {
03088           goto invalid_rail;
03089         }
03090 
03091         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03092           Track track = FindFirstTrack(chosen_track);
03093           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03094           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03095             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03096             MarkTileDirtyByTile(gp.new_tile);
03097           }
03098 
03099           /* Clear any track reservation when the last vehicle leaves the tile */
03100           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03101 
03102           v->tile = gp.new_tile;
03103 
03104           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03105             v->First()->RailtypeChanged();
03106           }
03107 
03108           v->track = chosen_track;
03109           assert(v->track);
03110         }
03111 
03112         /* We need to update signal status, but after the vehicle position hash
03113          * has been updated by UpdateInclination() */
03114         update_signals_crossing = true;
03115 
03116         if (chosen_dir != v->direction) {
03117           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03118             const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype];
03119             DirDiff diff = DirDifference(v->direction, chosen_dir);
03120             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03121           }
03122           direction_changed = true;
03123           v->direction = chosen_dir;
03124         }
03125 
03126         if (v->IsFrontEngine()) {
03127           v->wait_counter = 0;
03128 
03129           /* If we are approaching a crossing that is reserved, play the sound now. */
03130           TileIndex crossing = TrainApproachingCrossingTile(v);
03131           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03132 
03133           /* Always try to extend the reservation when entering a tile. */
03134           CheckNextTrainTile(v);
03135         }
03136 
03137         if (HasBit(r, VETS_ENTERED_STATION)) {
03138           /* The new position is the location where we want to stop */
03139           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03140         }
03141       }
03142     } else {
03143       /* In a tunnel or on a bridge
03144        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03145        * - for bridges, only the middle part - without the bridge heads */
03146       if (!(v->vehstatus & VS_HIDDEN)) {
03147         Train *first = v->First();
03148         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03149       }
03150 
03151       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03152         /* Perform look-ahead on tunnel exit. */
03153         if (v->IsFrontEngine()) {
03154           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03155           CheckNextTrainTile(v);
03156         }
03157         /* Prevent v->UpdateInclination() being called with wrong parameters.
03158          * This could happen if the train was reversed inside the tunnel/bridge. */
03159         if (gp.old_tile == gp.new_tile) {
03160           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03161         }
03162       } else {
03163         v->x_pos = gp.x;
03164         v->y_pos = gp.y;
03165         VehicleMove(v, !(v->vehstatus & VS_HIDDEN));
03166         continue;
03167       }
03168     }
03169 
03170     /* update image of train, as well as delta XY */
03171     v->UpdateDeltaXY(v->direction);
03172 
03173     v->x_pos = gp.x;
03174     v->y_pos = gp.y;
03175 
03176     /* update the Z position of the vehicle */
03177     byte old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03178 
03179     if (prev == NULL) {
03180       /* This is the first vehicle in the train */
03181       AffectSpeedByZChange(v, old_z);
03182     }
03183 
03184     if (update_signals_crossing) {
03185       if (v->IsFrontEngine()) {
03186         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03187           /* We are entering a block with PBS signals right now, but
03188            * not through a PBS signal. This means we don't have a
03189            * reservation right now. As a conventional signal will only
03190            * ever be green if no other train is in the block, getting
03191            * a path should always be possible. If the player built
03192            * such a strange network that it is not possible, the train
03193            * will be marked as stuck and the player has to deal with
03194            * the problem. */
03195           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03196               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03197               !TryPathReserve(v)) {
03198             MarkTrainAsStuck(v);
03199           }
03200         }
03201       }
03202 
03203       /* Signals can only change when the first
03204        * (above) or the last vehicle moves. */
03205       if (v->Next() == NULL) {
03206         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03207         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03208       }
03209     }
03210 
03211     /* Do not check on every tick to save some computing time. */
03212     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03213   }
03214 
03215   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03216 
03217   return;
03218 
03219 invalid_rail:
03220   /* We've reached end of line?? */
03221   if (prev != NULL) error("Disconnecting train");
03222 
03223 reverse_train_direction:
03224   v->wait_counter = 0;
03225   v->cur_speed = 0;
03226   v->subspeed = 0;
03227   ReverseTrainDirection(v);
03228 }
03229 
03236 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03237 {
03238   TrackBits *trackbits = (TrackBits *)data;
03239 
03240   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03241     TrackBits train_tbits = Train::From(v)->track;
03242     if (train_tbits == TRACK_BIT_WORMHOLE) {
03243       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03244       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03245     } else if (train_tbits != TRACK_BIT_DEPOT) {
03246       *trackbits |= train_tbits;
03247     }
03248   }
03249 
03250   return NULL;
03251 }
03252 
03260 static void DeleteLastWagon(Train *v)
03261 {
03262   Train *first = v->First();
03263 
03264   /* Go to the last wagon and delete the link pointing there
03265    * *u is then the one-before-last wagon, and *v the last
03266    * one which will physically be removed */
03267   Train *u = v;
03268   for (; v->Next() != NULL; v = v->Next()) u = v;
03269   u->SetNext(NULL);
03270 
03271   if (first != v) {
03272     /* Recalculate cached train properties */
03273     first->ConsistChanged(false);
03274     /* Update the depot window if the first vehicle is in depot -
03275      * if v == first, then it is updated in PreDestructor() */
03276     if (first->track == TRACK_BIT_DEPOT) {
03277       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03278     }
03279   }
03280 
03281   /* 'v' shouldn't be accessed after it has been deleted */
03282   TrackBits trackbits = v->track;
03283   TileIndex tile = v->tile;
03284   Owner owner = v->owner;
03285 
03286   delete v;
03287   v = NULL; // make sure nobody will try to read 'v' anymore
03288 
03289   if (trackbits == TRACK_BIT_WORMHOLE) {
03290     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03291     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03292   }
03293 
03294   Track track = TrackBitsToTrack(trackbits);
03295   if (HasReservedTracks(tile, trackbits)) {
03296     UnreserveRailTrack(tile, track);
03297 
03298     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03299     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03300     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03301 
03302     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03303     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03304     Track t;
03305     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03306   }
03307 
03308   /* check if the wagon was on a road/rail-crossing */
03309   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03310 
03311   /* Update signals */
03312   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03313     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03314   } else {
03315     SetSignalsOnBothDir(tile, track, owner);
03316   }
03317 }
03318 
03323 static void ChangeTrainDirRandomly(Train *v)
03324 {
03325   static const DirDiff delta[] = {
03326     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03327   };
03328 
03329   do {
03330     /* We don't need to twist around vehicles if they're not visible */
03331     if (!(v->vehstatus & VS_HIDDEN)) {
03332       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03333       v->UpdateDeltaXY(v->direction);
03334       v->cur_image = v->GetImage(v->direction);
03335       /* Refrain from updating the z position of the vehicle when on
03336        * a bridge, because UpdateInclination() will put the vehicle under
03337        * the bridge in that case */
03338       if (v->track != TRACK_BIT_WORMHOLE) v->UpdateInclination(false, false);
03339     }
03340   } while ((v = v->Next()) != NULL);
03341 }
03342 
03348 static bool HandleCrashedTrain(Train *v)
03349 {
03350   int state = ++v->crash_anim_pos;
03351 
03352   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03353     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03354   }
03355 
03356   uint32 r;
03357   if (state <= 200 && Chance16R(1, 7, r)) {
03358     int index = (r * 10 >> 16);
03359 
03360     Vehicle *u = v;
03361     do {
03362       if (--index < 0) {
03363         r = Random();
03364 
03365         CreateEffectVehicleRel(u,
03366           GB(r,  8, 3) + 2,
03367           GB(r, 16, 3) + 2,
03368           GB(r,  0, 3) + 5,
03369           EV_EXPLOSION_SMALL);
03370         break;
03371       }
03372     } while ((u = u->Next()) != NULL);
03373   }
03374 
03375   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03376 
03377   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03378     bool ret = v->Next() != NULL;
03379     DeleteLastWagon(v);
03380     return ret;
03381   }
03382 
03383   return true;
03384 }
03385 
03387 static const uint16 _breakdown_speeds[16] = {
03388   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03389 };
03390 
03391 
03399 static bool TrainApproachingLineEnd(Train *v, bool signal)
03400 {
03401   /* Calc position within the current tile */
03402   uint x = v->x_pos & 0xF;
03403   uint y = v->y_pos & 0xF;
03404 
03405   /* for diagonal directions, 'x' will be 0..15 -
03406    * for other directions, it will be 1, 3, 5, ..., 15 */
03407   switch (v->direction) {
03408     case DIR_N : x = ~x + ~y + 25; break;
03409     case DIR_NW: x = y;            // FALL THROUGH
03410     case DIR_NE: x = ~x + 16;      break;
03411     case DIR_E : x = ~x + y + 9;   break;
03412     case DIR_SE: x = y;            break;
03413     case DIR_S : x = x + y - 7;    break;
03414     case DIR_W : x = ~y + x + 9;   break;
03415     default: break;
03416   }
03417 
03418   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03419    * does not cross the tile boundary when we do reverse, but as the vehicle's
03420    * location is based on their center, use half a vehicle's length as offset.
03421    * Actually, the center of all vehicles is half a normal vehicle's length
03422    * from the front of the vehicle, so even in case the vehicle is 1/8th
03423    * long, the center is still at 1/2 of VEHICLE_LENGTH. Basically FS#3569. */
03424   if (!signal && x + VEHICLE_LENGTH / 2 >= TILE_SIZE) {
03425     /* we are too near the tile end, reverse now */
03426     v->cur_speed = 0;
03427     ReverseTrainDirection(v);
03428     return false;
03429   }
03430 
03431   /* slow down */
03432   v->vehstatus |= VS_TRAIN_SLOWING;
03433   uint16 break_speed = _breakdown_speeds[x & 0xF];
03434   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03435 
03436   return true;
03437 }
03438 
03439 
03445 static bool TrainCanLeaveTile(const Train *v)
03446 {
03447   /* Exit if inside a tunnel/bridge or a depot */
03448   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03449 
03450   TileIndex tile = v->tile;
03451 
03452   /* entering a tunnel/bridge? */
03453   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03454     DiagDirection dir = GetTunnelBridgeDirection(tile);
03455     if (DiagDirToDir(dir) == v->direction) return false;
03456   }
03457 
03458   /* entering a depot? */
03459   if (IsRailDepotTile(tile)) {
03460     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03461     if (DiagDirToDir(dir) == v->direction) return false;
03462   }
03463 
03464   return true;
03465 }
03466 
03467 
03475 static TileIndex TrainApproachingCrossingTile(const Train *v)
03476 {
03477   assert(v->IsFrontEngine());
03478   assert(!(v->vehstatus & VS_CRASHED));
03479 
03480   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03481 
03482   DiagDirection dir = TrainExitDir(v->direction, v->track);
03483   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03484 
03485   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03486   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03487       !CheckCompatibleRail(v, tile)) {
03488     return INVALID_TILE;
03489   }
03490 
03491   return tile;
03492 }
03493 
03494 
03501 static bool TrainCheckIfLineEnds(Train *v)
03502 {
03503   /* First, handle broken down train */
03504 
03505   int t = v->breakdown_ctr;
03506   if (t > 1) {
03507     v->vehstatus |= VS_TRAIN_SLOWING;
03508 
03509     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03510     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03511   } else {
03512     v->vehstatus &= ~VS_TRAIN_SLOWING;
03513   }
03514 
03515   if (!TrainCanLeaveTile(v)) return true;
03516 
03517   /* Determine the non-diagonal direction in which we will exit this tile */
03518   DiagDirection dir = TrainExitDir(v->direction, v->track);
03519   /* Calculate next tile */
03520   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03521 
03522   /* Determine the track status on the next tile */
03523   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03524   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03525 
03526   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03527   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03528 
03529   /* We are sure the train is not entering a depot, it is detected above */
03530 
03531   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03532   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03533   if (_settings_game.pf.forbid_90_deg) {
03534     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03535   }
03536 
03537   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03538   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03539     return TrainApproachingLineEnd(v, false);
03540   }
03541 
03542   /* approaching red signal */
03543   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true);
03544 
03545   /* approaching a rail/road crossing? then make it red */
03546   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03547 
03548   return true;
03549 }
03550 
03551 
03552 static bool TrainLocoHandler(Train *v, bool mode)
03553 {
03554   /* train has crashed? */
03555   if (v->vehstatus & VS_CRASHED) {
03556     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03557   }
03558 
03559   if (v->force_proceed != TFP_NONE) {
03560     ClrBit(v->flags, VRF_TRAIN_STUCK);
03561     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03562   }
03563 
03564   /* train is broken down? */
03565   if (v->HandleBreakdown()) return true;
03566 
03567   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03568     ReverseTrainDirection(v);
03569   }
03570 
03571   /* exit if train is stopped */
03572   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03573 
03574   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03575   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03576     v->wait_counter = 0;
03577     v->cur_speed = 0;
03578     v->subspeed = 0;
03579     ClrBit(v->flags, VRF_LEAVING_STATION);
03580     ReverseTrainDirection(v);
03581     return true;
03582   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03583     /* Try to reserve a path when leaving the station as we
03584      * might not be marked as wanting a reservation, e.g.
03585      * when an overlength train gets turned around in a station. */
03586     DiagDirection dir = TrainExitDir(v->direction, v->track);
03587     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03588 
03589     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03590       TryPathReserve(v, true, true);
03591     }
03592     ClrBit(v->flags, VRF_LEAVING_STATION);
03593   }
03594 
03595   v->HandleLoading(mode);
03596 
03597   if (v->current_order.IsType(OT_LOADING)) return true;
03598 
03599   if (CheckTrainStayInDepot(v)) return true;
03600 
03601   if (!mode) v->ShowVisualEffect();
03602 
03603   /* We had no order but have an order now, do look ahead. */
03604   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03605     CheckNextTrainTile(v);
03606   }
03607 
03608   /* Handle stuck trains. */
03609   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03610     ++v->wait_counter;
03611 
03612     /* Should we try reversing this tick if still stuck? */
03613     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03614 
03615     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03616     if (!TryPathReserve(v)) {
03617       /* Still stuck. */
03618       if (turn_around) ReverseTrainDirection(v);
03619 
03620       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03621         /* Show message to player. */
03622         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03623           SetDParam(0, v->index);
03624           AddVehicleNewsItem(
03625             STR_NEWS_TRAIN_IS_STUCK,
03626             NS_ADVICE,
03627             v->index
03628           );
03629         }
03630         v->wait_counter = 0;
03631       }
03632       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03633       if (v->force_proceed == TFP_NONE) return true;
03634       ClrBit(v->flags, VRF_TRAIN_STUCK);
03635       v->wait_counter = 0;
03636       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03637     }
03638   }
03639 
03640   if (v->current_order.IsType(OT_LEAVESTATION)) {
03641     v->current_order.Free();
03642     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03643     return true;
03644   }
03645 
03646   int j = v->UpdateSpeed();
03647 
03648   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03649   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03650     /* If we manually stopped, we're not force-proceeding anymore. */
03651     v->force_proceed = TFP_NONE;
03652     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03653   }
03654 
03655   int adv_spd = v->GetAdvanceDistance();
03656   if (j < adv_spd) {
03657     /* if the vehicle has speed 0, update the last_speed field. */
03658     if (v->cur_speed == 0) v->SetLastSpeed();
03659   } else {
03660     TrainCheckIfLineEnds(v);
03661     /* Loop until the train has finished moving. */
03662     for (;;) {
03663       j -= adv_spd;
03664       TrainController(v, NULL);
03665       /* Don't continue to move if the train crashed. */
03666       if (CheckTrainCollision(v)) break;
03667       /* Determine distance to next map position */
03668       adv_spd = v->GetAdvanceDistance();
03669 
03670       /* No more moving this tick */
03671       if (j < adv_spd || v->cur_speed == 0) break;
03672 
03673       OrderType order_type = v->current_order.GetType();
03674       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03675       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03676             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03677             IsTileType(v->tile, MP_STATION) &&
03678             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03679         ProcessOrders(v);
03680       }
03681     }
03682     v->SetLastSpeed();
03683   }
03684 
03685   for (Train *u = v; u != NULL; u = u->Next()) {
03686     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03687 
03688     u->UpdateViewport(false, false);
03689   }
03690 
03691   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03692 
03693   return true;
03694 }
03695 
03696 
03697 
03698 Money Train::GetRunningCost() const
03699 {
03700   Money cost = 0;
03701   const Train *v = this;
03702 
03703   do {
03704     const Engine *e = Engine::Get(v->engine_type);
03705     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03706 
03707     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03708     if (cost_factor == 0) continue;
03709 
03710     /* Halve running cost for multiheaded parts */
03711     if (v->IsMultiheaded()) cost_factor /= 2;
03712 
03713     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->grf_prop.grffile);
03714   } while ((v = v->GetNextVehicle()) != NULL);
03715 
03716   return cost;
03717 }
03718 
03719 
03720 bool Train::Tick()
03721 {
03722   this->tick_counter++;
03723 
03724   if (this->IsFrontEngine()) {
03725     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03726 
03727     this->current_order_time++;
03728 
03729     if (!TrainLocoHandler(this, false)) return false;
03730 
03731     return TrainLocoHandler(this, true);
03732   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03733     /* Delete flooded standalone wagon chain */
03734     if (++this->crash_anim_pos >= 4400) {
03735       delete this;
03736       return false;
03737     }
03738   }
03739 
03740   return true;
03741 }
03742 
03743 static void CheckIfTrainNeedsService(Train *v)
03744 {
03745   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03746   if (v->IsInDepot()) {
03747     VehicleServiceInDepot(v);
03748     return;
03749   }
03750 
03751   uint max_penalty;
03752   switch (_settings_game.pf.pathfinder_for_trains) {
03753     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03754     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03755     default: NOT_REACHED();
03756   }
03757 
03758   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03759   /* Only go to the depot if it is not too far out of our way. */
03760   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03761     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03762       /* If we were already heading for a depot but it has
03763        * suddenly moved farther away, we continue our normal
03764        * schedule? */
03765       v->current_order.MakeDummy();
03766       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03767     }
03768     return;
03769   }
03770 
03771   DepotID depot = GetDepotIndex(tfdd.tile);
03772 
03773   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03774       v->current_order.GetDestination() != depot &&
03775       !Chance16(3, 16)) {
03776     return;
03777   }
03778 
03779   SetBit(v->gv_flags, GVF_SUPPRESS_AUTOMATIC_ORDERS);
03780   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03781   v->dest_tile = tfdd.tile;
03782   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03783 }
03784 
03785 void Train::OnNewDay()
03786 {
03787   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03788 
03789   if (this->IsFrontEngine()) {
03790     CheckVehicleBreakdown(this);
03791     AgeVehicle(this);
03792 
03793     CheckIfTrainNeedsService(this);
03794 
03795     CheckOrders(this);
03796 
03797     /* update destination */
03798     if (this->current_order.IsType(OT_GOTO_STATION)) {
03799       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03800       if (tile != INVALID_TILE) this->dest_tile = tile;
03801     }
03802 
03803     if (this->running_ticks != 0) {
03804       /* running costs */
03805       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03806 
03807       this->profit_this_year -= cost.GetCost();
03808       this->running_ticks = 0;
03809 
03810       SubtractMoneyFromCompanyFract(this->owner, cost);
03811 
03812       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03813       SetWindowClassesDirty(WC_TRAINS_LIST);
03814     }
03815   } else if (this->IsEngine()) {
03816     /* Also age engines that aren't front engines */
03817     AgeVehicle(this);
03818   }
03819 }
03820 
03821 Trackdir Train::GetVehicleTrackdir() const
03822 {
03823   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03824 
03825   if (this->track == TRACK_BIT_DEPOT) {
03826     /* We'll assume the train is facing outwards */
03827     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03828   }
03829 
03830   if (this->track == TRACK_BIT_WORMHOLE) {
03831     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03832     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03833   }
03834 
03835   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03836 }

Generated on Sun May 8 07:30:21 2011 for OpenTTD by  doxygen 1.6.1