train_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "error.h"
00014 #include "articulated_vehicles.h"
00015 #include "command_func.h"
00016 #include "pathfinder/npf/npf_func.h"
00017 #include "pathfinder/yapf/yapf.hpp"
00018 #include "news_func.h"
00019 #include "company_func.h"
00020 #include "newgrf_sound.h"
00021 #include "newgrf_text.h"
00022 #include "strings_func.h"
00023 #include "viewport_func.h"
00024 #include "vehicle_func.h"
00025 #include "sound_func.h"
00026 #include "ai/ai.hpp"
00027 #include "game/game.hpp"
00028 #include "newgrf_station.h"
00029 #include "effectvehicle_func.h"
00030 #include "network/network.h"
00031 #include "spritecache.h"
00032 #include "core/random_func.hpp"
00033 #include "company_base.h"
00034 #include "newgrf.h"
00035 #include "order_backup.h"
00036 #include "zoom_func.h"
00037 
00038 #include "table/strings.h"
00039 #include "table/train_cmd.h"
00040 
00041 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00042 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00043 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00044 static TileIndex TrainApproachingCrossingTile(const Train *v);
00045 static void CheckIfTrainNeedsService(Train *v);
00046 static void CheckNextTrainTile(Train *v);
00047 
00048 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00049 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00050 
00051 
00059 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00060 {
00061   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00062 
00063   DiagDirection diagdir = DirToDiagDir(direction);
00064 
00065   /* Determine the diagonal direction in which we will exit this tile */
00066   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00067     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00068   }
00069 
00070   return diagdir;
00071 }
00072 
00073 
00079 byte FreightWagonMult(CargoID cargo)
00080 {
00081   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00082   return _settings_game.vehicle.freight_trains;
00083 }
00084 
00086 void CheckTrainsLengths()
00087 {
00088   const Train *v;
00089   bool first = true;
00090 
00091   FOR_ALL_TRAINS(v) {
00092     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00093       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00094         if (u->track != TRACK_BIT_DEPOT) {
00095           if ((w->track != TRACK_BIT_DEPOT &&
00096               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00097               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00098             SetDParam(0, v->index);
00099             SetDParam(1, v->owner);
00100             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00101 
00102             if (!_networking && first) {
00103               first = false;
00104               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00105             }
00106             /* Break so we warn only once for each train. */
00107             break;
00108           }
00109         }
00110       }
00111     }
00112   }
00113 }
00114 
00121 void Train::ConsistChanged(bool same_length)
00122 {
00123   uint16 max_speed = UINT16_MAX;
00124 
00125   assert(this->IsFrontEngine() || this->IsFreeWagon());
00126 
00127   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00128   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00129   this->gcache.cached_total_length = 0;
00130   this->compatible_railtypes = RAILTYPES_NONE;
00131 
00132   bool train_can_tilt = true;
00133 
00134   for (Train *u = this; u != NULL; u = u->Next()) {
00135     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00136 
00137     /* Check the this->first cache. */
00138     assert(u->First() == this);
00139 
00140     /* update the 'first engine' */
00141     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00142     u->railtype = rvi_u->railtype;
00143 
00144     if (u->IsEngine()) first_engine = u->engine_type;
00145 
00146     /* Set user defined data to its default value */
00147     u->tcache.user_def_data = rvi_u->user_def_data;
00148     this->InvalidateNewGRFCache();
00149     u->InvalidateNewGRFCache();
00150   }
00151 
00152   for (Train *u = this; u != NULL; u = u->Next()) {
00153     /* Update user defined data (must be done before other properties) */
00154     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00155     this->InvalidateNewGRFCache();
00156     u->InvalidateNewGRFCache();
00157   }
00158 
00159   for (Train *u = this; u != NULL; u = u->Next()) {
00160     const Engine *e_u = u->GetEngine();
00161     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00162 
00163     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00164 
00165     /* Cache wagon override sprite group. NULL is returned if there is none */
00166     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00167 
00168     /* Reset colour map */
00169     u->colourmap = PAL_NONE;
00170 
00171     /* Update powered-wagon-status and visual effect */
00172     u->UpdateVisualEffect(true);
00173 
00174     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00175         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00176       /* wagon is powered */
00177       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00178     } else {
00179       ClrBit(u->flags, VRF_POWEREDWAGON);
00180     }
00181 
00182     if (!u->IsArticulatedPart()) {
00183       /* Do not count powered wagons for the compatible railtypes, as wagons always
00184          have railtype normal */
00185       if (rvi_u->power > 0) {
00186         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00187       }
00188 
00189       /* Some electric engines can be allowed to run on normal rail. It happens to all
00190        * existing electric engines when elrails are disabled and then re-enabled */
00191       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00192         u->railtype = RAILTYPE_RAIL;
00193         u->compatible_railtypes |= RAILTYPES_RAIL;
00194       }
00195 
00196       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00197       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00198         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00199         if (speed != 0) max_speed = min(speed, max_speed);
00200       }
00201     }
00202 
00203     u->cargo_cap = e_u->DetermineCapacity(u);
00204     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00205 
00206     /* check the vehicle length (callback) */
00207     uint16 veh_len = CALLBACK_FAILED;
00208     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00209       /* Use callback 36 */
00210       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00211     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00212       /* Use callback 11 */
00213       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00214     }
00215     if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00216       ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00217     }
00218     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00219     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00220 
00221     /* verify length hasn't changed */
00222     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00223 
00224     /* update vehicle length? */
00225     if (!same_length) u->gcache.cached_veh_length = veh_len;
00226 
00227     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00228     this->InvalidateNewGRFCache();
00229     u->InvalidateNewGRFCache();
00230   }
00231 
00232   /* store consist weight/max speed in cache */
00233   this->vcache.cached_max_speed = max_speed;
00234   this->tcache.cached_tilt = train_can_tilt;
00235   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00236 
00237   /* recalculate cached weights and power too (we do this *after* the rest, so it is known which wagons are powered and need extra weight added) */
00238   this->CargoChanged();
00239 
00240   if (this->IsFrontEngine()) {
00241     this->UpdateAcceleration();
00242     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00243     InvalidateWindowData(WC_VEHICLE_REFIT, this->index);
00244   }
00245 }
00246 
00257 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00258 {
00259   const Station *st = Station::Get(station_id);
00260   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00261   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00262 
00263   /* Default to the middle of the station for stations stops that are not in
00264    * the order list like intermediate stations when non-stop is disabled */
00265   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00266   if (v->gcache.cached_total_length >= *station_length) {
00267     /* The train is longer than the station, make it stop at the far end of the platform */
00268     osl = OSL_PLATFORM_FAR_END;
00269   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00270     osl = v->current_order.GetStopLocation();
00271   }
00272 
00273   /* The stop location of the FRONT! of the train */
00274   int stop;
00275   switch (osl) {
00276     default: NOT_REACHED();
00277 
00278     case OSL_PLATFORM_NEAR_END:
00279       stop = v->gcache.cached_total_length;
00280       break;
00281 
00282     case OSL_PLATFORM_MIDDLE:
00283       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00284       break;
00285 
00286     case OSL_PLATFORM_FAR_END:
00287       stop = *station_length;
00288       break;
00289   }
00290 
00291   /* Subtract half the front vehicle length of the train so we get the real
00292    * stop location of the train. */
00293   return stop - (v->gcache.cached_veh_length + 1) / 2;
00294 }
00295 
00296 
00301 int Train::GetCurveSpeedLimit() const
00302 {
00303   assert(this->First() == this);
00304 
00305   static const int absolute_max_speed = UINT16_MAX;
00306   int max_speed = absolute_max_speed;
00307 
00308   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00309 
00310   int curvecount[2] = {0, 0};
00311 
00312   /* first find the curve speed limit */
00313   int numcurve = 0;
00314   int sum = 0;
00315   int pos = 0;
00316   int lastpos = -1;
00317   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00318     Direction this_dir = u->direction;
00319     Direction next_dir = u->Next()->direction;
00320 
00321     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00322     if (dirdiff == DIRDIFF_SAME) continue;
00323 
00324     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00325     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00326     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00327       if (lastpos != -1) {
00328         numcurve++;
00329         sum += pos - lastpos;
00330         if (pos - lastpos == 1 && max_speed > 88) {
00331           max_speed = 88;
00332         }
00333       }
00334       lastpos = pos;
00335     }
00336 
00337     /* if we have a 90 degree turn, fix the speed limit to 60 */
00338     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00339       max_speed = 61;
00340     }
00341   }
00342 
00343   if (numcurve > 0 && max_speed > 88) {
00344     if (curvecount[0] == 1 && curvecount[1] == 1) {
00345       max_speed = absolute_max_speed;
00346     } else {
00347       sum /= numcurve;
00348       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00349     }
00350   }
00351 
00352   if (max_speed != absolute_max_speed) {
00353     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00354     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00355     max_speed += (max_speed / 2) * rti->curve_speed;
00356 
00357     if (this->tcache.cached_tilt) {
00358       /* Apply max_speed bonus of 20% for a tilting train */
00359       max_speed += max_speed / 5;
00360     }
00361   }
00362 
00363   return max_speed;
00364 }
00365 
00370 int Train::GetCurrentMaxSpeed() const
00371 {
00372   int max_speed = this->tcache.cached_max_curve_speed;
00373   assert(max_speed == this->GetCurveSpeedLimit());
00374 
00375   if (IsRailStationTile(this->tile)) {
00376     StationID sid = GetStationIndex(this->tile);
00377     if (this->current_order.ShouldStopAtStation(this, sid)) {
00378       int station_ahead;
00379       int station_length;
00380       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00381 
00382       /* The distance to go is whatever is still ahead of the train minus the
00383        * distance from the train's stop location to the end of the platform */
00384       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00385 
00386       if (distance_to_go > 0) {
00387         int st_max_speed = 120;
00388 
00389         int delta_v = this->cur_speed / (distance_to_go + 1);
00390         if (max_speed > (this->cur_speed - delta_v)) {
00391           st_max_speed = this->cur_speed - (delta_v / 10);
00392         }
00393 
00394         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00395         max_speed = min(max_speed, st_max_speed);
00396       }
00397     }
00398   }
00399 
00400   for (const Train *u = this; u != NULL; u = u->Next()) {
00401     if (u->track == TRACK_BIT_DEPOT) {
00402       max_speed = min(max_speed, 61);
00403       break;
00404     }
00405   }
00406 
00407   max_speed = min(max_speed, this->current_order.max_speed);
00408   return min(max_speed, this->gcache.cached_max_track_speed);
00409 }
00410 
00412 void Train::UpdateAcceleration()
00413 {
00414   assert(this->IsFrontEngine());
00415 
00416   uint power = this->gcache.cached_power;
00417   uint weight = this->gcache.cached_weight;
00418   assert(weight != 0);
00419   this->acceleration = Clamp(power / weight * 4, 1, 255);
00420 }
00421 
00427 int Train::GetDisplayImageWidth(Point *offset) const
00428 {
00429   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00430   int vehicle_pitch = 0;
00431 
00432   const Engine *e = this->GetEngine();
00433   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00434     reference_width = e->GetGRF()->traininfo_vehicle_width;
00435     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00436   }
00437 
00438   if (offset != NULL) {
00439     offset->x = reference_width / 2;
00440     offset->y = vehicle_pitch;
00441   }
00442   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00443 }
00444 
00445 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00446 {
00447   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00448 }
00449 
00456 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00457 {
00458   uint8 spritenum = this->spritenum;
00459   SpriteID sprite;
00460 
00461   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00462 
00463   if (is_custom_sprite(spritenum)) {
00464     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00465     if (sprite != 0) return sprite;
00466 
00467     spritenum = this->GetEngine()->original_image_index;
00468   }
00469 
00470   sprite = GetDefaultTrainSprite(spritenum, direction);
00471 
00472   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00473 
00474   return sprite;
00475 }
00476 
00477 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00478 {
00479   const Engine *e = Engine::Get(engine);
00480   Direction dir = rear_head ? DIR_E : DIR_W;
00481   uint8 spritenum = e->u.rail.image_index;
00482 
00483   if (is_custom_sprite(spritenum)) {
00484     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00485     if (sprite != 0) {
00486       if (e->GetGRF() != NULL) {
00487         y += e->GetGRF()->traininfo_vehicle_pitch;
00488       }
00489       return sprite;
00490     }
00491 
00492     spritenum = Engine::Get(engine)->original_image_index;
00493   }
00494 
00495   if (rear_head) spritenum++;
00496 
00497   return GetDefaultTrainSprite(spritenum, DIR_W);
00498 }
00499 
00500 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00501 {
00502   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00503     int yf = y;
00504     int yr = y;
00505 
00506     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00507     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00508     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00509     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00510 
00511     preferred_x = Clamp(preferred_x, left - UnScaleByZoom(real_spritef->x_offs, ZOOM_LVL_GUI) + 14, right - UnScaleByZoom(real_spriter->width, ZOOM_LVL_GUI) - UnScaleByZoom(real_spriter->x_offs, ZOOM_LVL_GUI) - 15);
00512 
00513     DrawSprite(spritef, pal, preferred_x - 14, yf);
00514     DrawSprite(spriter, pal, preferred_x + 15, yr);
00515   } else {
00516     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00517     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00518     preferred_x = Clamp(preferred_x, left - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI), right - UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI));
00519     DrawSprite(sprite, pal, preferred_x, y);
00520   }
00521 }
00522 
00531 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00532 {
00533   const RailVehicleInfo *rvi = &e->u.rail;
00534 
00535   /* Check that the wagon can drive on the track in question */
00536   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00537 
00538   if (flags & DC_EXEC) {
00539     Train *v = new Train();
00540     *ret = v;
00541     v->spritenum = rvi->image_index;
00542 
00543     v->engine_type = e->index;
00544     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00545 
00546     DiagDirection dir = GetRailDepotDirection(tile);
00547 
00548     v->direction = DiagDirToDir(dir);
00549     v->tile = tile;
00550 
00551     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00552     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00553 
00554     v->x_pos = x;
00555     v->y_pos = y;
00556     v->z_pos = GetSlopePixelZ(x, y);
00557     v->owner = _current_company;
00558     v->track = TRACK_BIT_DEPOT;
00559     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00560 
00561     v->SetWagon();
00562 
00563     v->SetFreeWagon();
00564     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00565 
00566     v->cargo_type = e->GetDefaultCargoType();
00567     v->cargo_cap = rvi->capacity;
00568 
00569     v->railtype = rvi->railtype;
00570 
00571     v->build_year = _cur_year;
00572     v->cur_image = SPR_IMG_QUERY;
00573     v->random_bits = VehicleRandomBits();
00574 
00575     v->group_id = DEFAULT_GROUP;
00576 
00577     AddArticulatedParts(v);
00578 
00579     _new_vehicle_id = v->index;
00580 
00581     VehicleUpdatePosition(v);
00582     v->First()->ConsistChanged(false);
00583     UpdateTrainGroupID(v->First());
00584 
00585     CheckConsistencyOfArticulatedVehicle(v);
00586 
00587     /* Try to connect the vehicle to one of free chains of wagons. */
00588     Train *w;
00589     FOR_ALL_TRAINS(w) {
00590       if (w->tile == tile &&              
00591           w->IsFreeWagon() &&             
00592           w->engine_type == e->index &&   
00593           w->First() != v &&              
00594           !(w->vehstatus & VS_CRASHED)) { 
00595         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00596         break;
00597       }
00598     }
00599   }
00600 
00601   return CommandCost();
00602 }
00603 
00605 static void NormalizeTrainVehInDepot(const Train *u)
00606 {
00607   const Train *v;
00608   FOR_ALL_TRAINS(v) {
00609     if (v->IsFreeWagon() && v->tile == u->tile &&
00610         v->track == TRACK_BIT_DEPOT) {
00611       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00612           CMD_MOVE_RAIL_VEHICLE).Failed())
00613         break;
00614     }
00615   }
00616 }
00617 
00618 static void AddRearEngineToMultiheadedTrain(Train *v)
00619 {
00620   Train *u = new Train();
00621   v->value >>= 1;
00622   u->value = v->value;
00623   u->direction = v->direction;
00624   u->owner = v->owner;
00625   u->tile = v->tile;
00626   u->x_pos = v->x_pos;
00627   u->y_pos = v->y_pos;
00628   u->z_pos = v->z_pos;
00629   u->track = TRACK_BIT_DEPOT;
00630   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00631   u->spritenum = v->spritenum + 1;
00632   u->cargo_type = v->cargo_type;
00633   u->cargo_subtype = v->cargo_subtype;
00634   u->cargo_cap = v->cargo_cap;
00635   u->railtype = v->railtype;
00636   u->engine_type = v->engine_type;
00637   u->build_year = v->build_year;
00638   u->cur_image = SPR_IMG_QUERY;
00639   u->random_bits = VehicleRandomBits();
00640   v->SetMultiheaded();
00641   u->SetMultiheaded();
00642   v->SetNext(u);
00643   VehicleUpdatePosition(u);
00644 
00645   /* Now we need to link the front and rear engines together */
00646   v->other_multiheaded_part = u;
00647   u->other_multiheaded_part = v;
00648 }
00649 
00659 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00660 {
00661   const RailVehicleInfo *rvi = &e->u.rail;
00662 
00663   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00664 
00665   /* Check if depot and new engine uses the same kind of tracks *
00666    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00667   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00668 
00669   if (flags & DC_EXEC) {
00670     DiagDirection dir = GetRailDepotDirection(tile);
00671     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00672     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00673 
00674     Train *v = new Train();
00675     *ret = v;
00676     v->direction = DiagDirToDir(dir);
00677     v->tile = tile;
00678     v->owner = _current_company;
00679     v->x_pos = x;
00680     v->y_pos = y;
00681     v->z_pos = GetSlopePixelZ(x, y);
00682     v->track = TRACK_BIT_DEPOT;
00683     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00684     v->spritenum = rvi->image_index;
00685     v->cargo_type = e->GetDefaultCargoType();
00686     v->cargo_cap = rvi->capacity;
00687     v->last_station_visited = INVALID_STATION;
00688     v->last_loading_station = INVALID_STATION;
00689 
00690     v->engine_type = e->index;
00691     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00692 
00693     v->reliability = e->reliability;
00694     v->reliability_spd_dec = e->reliability_spd_dec;
00695     v->max_age = e->GetLifeLengthInDays();
00696 
00697     v->railtype = rvi->railtype;
00698     _new_vehicle_id = v->index;
00699 
00700     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00701     v->date_of_last_service = _date;
00702     v->build_year = _cur_year;
00703     v->cur_image = SPR_IMG_QUERY;
00704     v->random_bits = VehicleRandomBits();
00705 
00706     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00707 
00708     v->group_id = DEFAULT_GROUP;
00709 
00710     v->SetFrontEngine();
00711     v->SetEngine();
00712 
00713     VehicleUpdatePosition(v);
00714 
00715     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00716       AddRearEngineToMultiheadedTrain(v);
00717     } else {
00718       AddArticulatedParts(v);
00719     }
00720 
00721     v->ConsistChanged(false);
00722     UpdateTrainGroupID(v);
00723 
00724     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00725       NormalizeTrainVehInDepot(v);
00726     }
00727 
00728     CheckConsistencyOfArticulatedVehicle(v);
00729   }
00730 
00731   return CommandCost();
00732 }
00733 
00738 bool Train::IsInDepot() const
00739 {
00740   /* Is the front engine stationary in the depot? */
00741   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00742 
00743   /* Check whether the rest is also already trying to enter the depot. */
00744   for (const Train *v = this; v != NULL; v = v->Next()) {
00745     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00746   }
00747 
00748   return true;
00749 }
00750 
00755 bool Train::IsStoppedInDepot() const
00756 {
00757   /* Are we stopped? Of course wagons don't really care... */
00758   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00759   return this->IsInDepot();
00760 }
00761 
00762 static Train *FindGoodVehiclePos(const Train *src)
00763 {
00764   EngineID eng = src->engine_type;
00765   TileIndex tile = src->tile;
00766 
00767   Train *dst;
00768   FOR_ALL_TRAINS(dst) {
00769     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00770       /* check so all vehicles in the line have the same engine. */
00771       Train *t = dst;
00772       while (t->engine_type == eng) {
00773         t = t->Next();
00774         if (t == NULL) return dst;
00775       }
00776     }
00777   }
00778 
00779   return NULL;
00780 }
00781 
00783 typedef SmallVector<Train *, 16> TrainList;
00784 
00790 static void MakeTrainBackup(TrainList &list, Train *t)
00791 {
00792   for (; t != NULL; t = t->Next()) *list.Append() = t;
00793 }
00794 
00799 static void RestoreTrainBackup(TrainList &list)
00800 {
00801   /* No train, nothing to do. */
00802   if (list.Length() == 0) return;
00803 
00804   Train *prev = NULL;
00805   /* Iterate over the list and rebuild it. */
00806   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00807     Train *t = *iter;
00808     if (prev != NULL) {
00809       prev->SetNext(t);
00810     } else if (t->Previous() != NULL) {
00811       /* Make sure the head of the train is always the first in the chain. */
00812       t->Previous()->SetNext(NULL);
00813     }
00814     prev = t;
00815   }
00816 }
00817 
00823 static void RemoveFromConsist(Train *part, bool chain = false)
00824 {
00825   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00826 
00827   /* Unlink at the front, but make it point to the next
00828    * vehicle after the to be remove part. */
00829   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00830 
00831   /* Unlink at the back */
00832   tail->SetNext(NULL);
00833 }
00834 
00840 static void InsertInConsist(Train *dst, Train *chain)
00841 {
00842   /* We do not want to add something in the middle of an articulated part. */
00843   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00844 
00845   chain->Last()->SetNext(dst->Next());
00846   dst->SetNext(chain);
00847 }
00848 
00854 static void NormaliseDualHeads(Train *t)
00855 {
00856   for (; t != NULL; t = t->GetNextVehicle()) {
00857     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00858 
00859     /* Make sure that there are no free cars before next engine */
00860     Train *u;
00861     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00862 
00863     if (u == t->other_multiheaded_part) continue;
00864 
00865     /* Remove the part from the 'wrong' train */
00866     RemoveFromConsist(t->other_multiheaded_part);
00867     /* And add it to the 'right' train */
00868     InsertInConsist(u, t->other_multiheaded_part);
00869   }
00870 }
00871 
00876 static void NormaliseSubtypes(Train *chain)
00877 {
00878   /* Nothing to do */
00879   if (chain == NULL) return;
00880 
00881   /* We must be the first in the chain. */
00882   assert(chain->Previous() == NULL);
00883 
00884   /* Set the appropriate bits for the first in the chain. */
00885   if (chain->IsWagon()) {
00886     chain->SetFreeWagon();
00887   } else {
00888     assert(chain->IsEngine());
00889     chain->SetFrontEngine();
00890   }
00891 
00892   /* Now clear the bits for the rest of the chain */
00893   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00894     t->ClearFreeWagon();
00895     t->ClearFrontEngine();
00896   }
00897 }
00898 
00908 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00909 {
00910   /* Just add 'new' engines and subtract the original ones.
00911    * If that's less than or equal to 0 we can be sure we did
00912    * not add any engines (read: trains) along the way. */
00913   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00914       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00915       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00916       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00917     return CommandCost();
00918   }
00919 
00920   /* Get a free unit number and check whether it's within the bounds.
00921    * There will always be a maximum of one new train. */
00922   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00923 
00924   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00925 }
00926 
00932 static CommandCost CheckTrainAttachment(Train *t)
00933 {
00934   /* No multi-part train, no need to check. */
00935   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00936 
00937   /* The maximum length for a train. For each part we decrease this by one
00938    * and if the result is negative the train is simply too long. */
00939   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00940 
00941   Train *head = t;
00942   Train *prev = t;
00943 
00944   /* Break the prev -> t link so it always holds within the loop. */
00945   t = t->Next();
00946   prev->SetNext(NULL);
00947 
00948   /* Make sure the cache is cleared. */
00949   head->InvalidateNewGRFCache();
00950 
00951   while (t != NULL) {
00952     allowed_len -= t->gcache.cached_veh_length;
00953 
00954     Train *next = t->Next();
00955 
00956     /* Unlink the to-be-added piece; it is already unlinked from the previous
00957      * part due to the fact that the prev -> t link is broken. */
00958     t->SetNext(NULL);
00959 
00960     /* Don't check callback for articulated or rear dual headed parts */
00961     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00962       /* Back up and clear the first_engine data to avoid using wagon override group */
00963       EngineID first_engine = t->gcache.first_engine;
00964       t->gcache.first_engine = INVALID_ENGINE;
00965 
00966       /* We don't want the cache to interfere. head's cache is cleared before
00967        * the loop and after each callback does not need to be cleared here. */
00968       t->InvalidateNewGRFCache();
00969 
00970       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00971 
00972       /* Restore original first_engine data */
00973       t->gcache.first_engine = first_engine;
00974 
00975       /* We do not want to remember any cached variables from the test run */
00976       t->InvalidateNewGRFCache();
00977       head->InvalidateNewGRFCache();
00978 
00979       if (callback != CALLBACK_FAILED) {
00980         /* A failing callback means everything is okay */
00981         StringID error = STR_NULL;
00982 
00983         if (head->GetGRF()->grf_version < 8) {
00984           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00985           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00986           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00987         } else {
00988           if (callback < 0x400) {
00989             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00990           } else {
00991             switch (callback) {
00992               case 0x400: // allow if railtypes match (always the case for OpenTTD)
00993               case 0x401: // allow
00994                 break;
00995 
00996               default:    // unknown reason -> disallow
00997               case 0x402: // disallow attaching
00998                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00999                 break;
01000             }
01001           }
01002         }
01003 
01004         if (error != STR_NULL) return_cmd_error(error);
01005       }
01006     }
01007 
01008     /* And link it to the new part. */
01009     prev->SetNext(t);
01010     prev = t;
01011     t = next;
01012   }
01013 
01014   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01015   return CommandCost();
01016 }
01017 
01028 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01029 {
01030   /* Check whether we may actually construct the trains. */
01031   CommandCost ret = CheckTrainAttachment(src);
01032   if (ret.Failed()) return ret;
01033   ret = CheckTrainAttachment(dst);
01034   if (ret.Failed()) return ret;
01035 
01036   /* Check whether we need to build a new train. */
01037   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01038 }
01039 
01048 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01049 {
01050   /* First determine the front of the two resulting trains */
01051   if (*src_head == *dst_head) {
01052     /* If we aren't moving part(s) to a new train, we are just moving the
01053      * front back and there is not destination head. */
01054     *dst_head = NULL;
01055   } else if (*dst_head == NULL) {
01056     /* If we are moving to a new train the head of the move train would become
01057      * the head of the new vehicle. */
01058     *dst_head = src;
01059   }
01060 
01061   if (src == *src_head) {
01062     /* If we are moving the front of a train then we are, in effect, creating
01063      * a new head for the train. Point to that. Unless we are moving the whole
01064      * train in which case there is not 'source' train anymore.
01065      * In case we are a multiheaded part we want the complete thing to come
01066      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01067      * that is followed by a rear multihead we do not want to include that. */
01068     *src_head = move_chain ? NULL :
01069         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01070   }
01071 
01072   /* Now it's just simply removing the part that we are going to move from the
01073    * source train and *if* the destination is a not a new train add the chain
01074    * at the destination location. */
01075   RemoveFromConsist(src, move_chain);
01076   if (*dst_head != src) InsertInConsist(dst, src);
01077 
01078   /* Now normalise the dual heads, that is move the dual heads around in such
01079    * a way that the head and rear of a dual head are in the same train */
01080   NormaliseDualHeads(*src_head);
01081   NormaliseDualHeads(*dst_head);
01082 }
01083 
01089 static void NormaliseTrainHead(Train *head)
01090 {
01091   /* Not much to do! */
01092   if (head == NULL) return;
01093 
01094   /* Tell the 'world' the train changed. */
01095   head->ConsistChanged(false);
01096   UpdateTrainGroupID(head);
01097 
01098   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01099   if (!head->IsFrontEngine()) return;
01100 
01101   /* Update the refit button and window */
01102   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01103   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01104 
01105   /* If we don't have a unit number yet, set one. */
01106   if (head->unitnumber != 0) return;
01107   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01108 }
01109 
01122 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01123 {
01124   VehicleID s = GB(p1, 0, 20);
01125   VehicleID d = GB(p2, 0, 20);
01126   bool move_chain = HasBit(p1, 20);
01127 
01128   Train *src = Train::GetIfValid(s);
01129   if (src == NULL) return CMD_ERROR;
01130 
01131   CommandCost ret = CheckOwnership(src->owner);
01132   if (ret.Failed()) return ret;
01133 
01134   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01135   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01136 
01137   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01138   Train *dst;
01139   if (d == INVALID_VEHICLE) {
01140     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01141   } else {
01142     dst = Train::GetIfValid(d);
01143     if (dst == NULL) return CMD_ERROR;
01144 
01145     CommandCost ret = CheckOwnership(dst->owner);
01146     if (ret.Failed()) return ret;
01147 
01148     /* Do not allow appending to crashed vehicles, too */
01149     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01150   }
01151 
01152   /* if an articulated part is being handled, deal with its parent vehicle */
01153   src = src->GetFirstEnginePart();
01154   if (dst != NULL) {
01155     dst = dst->GetFirstEnginePart();
01156   }
01157 
01158   /* don't move the same vehicle.. */
01159   if (src == dst) return CommandCost();
01160 
01161   /* locate the head of the two chains */
01162   Train *src_head = src->First();
01163   Train *dst_head;
01164   if (dst != NULL) {
01165     dst_head = dst->First();
01166     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01167     /* Now deal with articulated part of destination wagon */
01168     dst = dst->GetLastEnginePart();
01169   } else {
01170     dst_head = NULL;
01171   }
01172 
01173   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01174 
01175   /* When moving all wagons, we can't have the same src_head and dst_head */
01176   if (move_chain && src_head == dst_head) return CommandCost();
01177 
01178   /* When moving a multiheaded part to be place after itself, bail out. */
01179   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01180 
01181   /* Check if all vehicles in the source train are stopped inside a depot. */
01182   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01183 
01184   /* Check if all vehicles in the destination train are stopped inside a depot. */
01185   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01186 
01187   /* First make a backup of the order of the trains. That way we can do
01188    * whatever we want with the order and later on easily revert. */
01189   TrainList original_src;
01190   TrainList original_dst;
01191 
01192   MakeTrainBackup(original_src, src_head);
01193   MakeTrainBackup(original_dst, dst_head);
01194 
01195   /* Also make backup of the original heads as ArrangeTrains can change them.
01196    * For the destination head we do not care if it is the same as the source
01197    * head because in that case it's just a copy. */
01198   Train *original_src_head = src_head;
01199   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01200 
01201   /* We want this information from before the rearrangement, but execute this after the validation. */
01202   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01203   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01204 
01205   /* (Re)arrange the trains in the wanted arrangement. */
01206   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01207 
01208   if ((flags & DC_AUTOREPLACE) == 0) {
01209     /* If the autoreplace flag is set we do not need to test for the validity
01210      * because we are going to revert the train to its original state. As we
01211      * assume the original state was correct autoreplace can skip this. */
01212     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01213     if (ret.Failed()) {
01214       /* Restore the train we had. */
01215       RestoreTrainBackup(original_src);
01216       RestoreTrainBackup(original_dst);
01217       return ret;
01218     }
01219   }
01220 
01221   /* do it? */
01222   if (flags & DC_EXEC) {
01223     /* Remove old heads from the statistics */
01224     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01225     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01226 
01227     /* First normalise the sub types of the chains. */
01228     NormaliseSubtypes(src_head);
01229     NormaliseSubtypes(dst_head);
01230 
01231     /* There are 14 different cases:
01232      *  1) front engine gets moved to a new train, it stays a front engine.
01233      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01234      *     b) the 'next' part is an engine that becomes a front engine.
01235      *     c) there is no 'next' part, nothing else happens
01236      *  2) front engine gets moved to another train, it is not a front engine anymore
01237      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01238      *     b) the 'next' part is an engine that becomes a front engine.
01239      *     c) there is no 'next' part, nothing else happens
01240      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01241      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01242      *     b) the 'next' part is an engine that becomes a front engine.
01243      *  4) free wagon gets moved
01244      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01245      *     b) the 'next' part is an engine that becomes a front engine.
01246      *     c) there is no 'next' part, nothing else happens
01247      *  5) non front engine gets moved and becomes a new train, nothing else happens
01248      *  6) non front engine gets moved within a train / to another train, nothing hapens
01249      *  7) wagon gets moved, nothing happens
01250      */
01251     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01252       /* Cases #2 and #3: the front engine gets trashed. */
01253       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01254       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01255       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01256       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01257       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01258       SetWindowDirty(WC_COMPANY, _current_company);
01259 
01260       /* Delete orders, group stuff and the unit number as we're not the
01261        * front of any vehicle anymore. */
01262       DeleteVehicleOrders(src);
01263       RemoveVehicleFromGroup(src);
01264       src->unitnumber = 0;
01265     }
01266 
01267     /* We weren't a front engine but are becoming one. So
01268      * we should be put in the default group. */
01269     if (original_src_head != src && dst_head == src) {
01270       SetTrainGroupID(src, DEFAULT_GROUP);
01271       SetWindowDirty(WC_COMPANY, _current_company);
01272     }
01273 
01274     /* Add new heads to statistics */
01275     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01276     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01277 
01278     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01279     NormaliseTrainHead(src_head);
01280     NormaliseTrainHead(dst_head);
01281 
01282     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01283       CheckCargoCapacity(src_head);
01284       CheckCargoCapacity(dst_head);
01285     }
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       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
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   /* Set common defaults. */
01392   this->x_offs    = -1;
01393   this->y_offs    = -1;
01394   this->x_extent  =  3;
01395   this->y_extent  =  3;
01396   this->z_extent  =  6;
01397   this->x_bb_offs =  0;
01398   this->y_bb_offs =  0;
01399 
01400   if (!IsDiagonalDirection(direction)) {
01401     static const int _sign_table[] =
01402     {
01403       // x, y
01404       -1, -1, // DIR_N
01405       -1,  1, // DIR_E
01406        1,  1, // DIR_S
01407        1, -1, // DIR_W
01408     };
01409 
01410     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01411 
01412     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01413     this->x_offs -= half_shorten * _sign_table[direction];
01414     this->y_offs -= half_shorten * _sign_table[direction + 1];
01415     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01416     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01417   } else {
01418     switch (direction) {
01419         /* Shorten southern corner of the bounding box according the vehicle length
01420          * and center the bounding box on the vehicle. */
01421       case DIR_NE:
01422         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01423         this->x_extent  = this->gcache.cached_veh_length - 1;
01424         this->x_bb_offs = -1;
01425         break;
01426 
01427       case DIR_NW:
01428         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01429         this->y_extent  = this->gcache.cached_veh_length - 1;
01430         this->y_bb_offs = -1;
01431         break;
01432 
01433         /* Move northern corner of the bounding box down according to vehicle length
01434          * and center the bounding box on the vehicle. */
01435       case DIR_SW:
01436         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01437         this->x_extent  = VEHICLE_LENGTH - 1;
01438         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01439         break;
01440 
01441       case DIR_SE:
01442         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01443         this->y_extent  = VEHICLE_LENGTH - 1;
01444         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01445         break;
01446 
01447       default:
01448         NOT_REACHED();
01449     }
01450   }
01451 }
01452 
01457 static void MarkTrainAsStuck(Train *v)
01458 {
01459   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01460     /* It is the first time the problem occurred, set the "train stuck" flag. */
01461     SetBit(v->flags, VRF_TRAIN_STUCK);
01462 
01463     v->wait_counter = 0;
01464 
01465     /* Stop train */
01466     v->cur_speed = 0;
01467     v->subspeed = 0;
01468     v->SetLastSpeed();
01469 
01470     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01471   }
01472 }
01473 
01481 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01482 {
01483   uint16 flag1 = *swap_flag1;
01484   uint16 flag2 = *swap_flag2;
01485 
01486   /* Clear the flags */
01487   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01488   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01489   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01490   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01491 
01492   /* Reverse the rail-flags (if needed) */
01493   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01494     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01495   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01496     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01497   }
01498   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01499     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01500   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01501     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01502   }
01503 }
01504 
01509 static void UpdateStatusAfterSwap(Train *v)
01510 {
01511   /* Reverse the direction. */
01512   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01513 
01514   /* Call the proper EnterTile function unless we are in a wormhole. */
01515   if (v->track != TRACK_BIT_WORMHOLE) {
01516     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01517   } else {
01518     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01519      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01520      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01521      * when we shouldn't have. Check if this is the case. */
01522     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01523     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01524       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01525       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01526         /* We have just left the wormhole, possibly set the
01527          * "goingdown" bit. UpdateInclination() can be used
01528          * because we are at the border of the tile. */
01529         VehicleUpdatePosition(v);
01530         v->UpdateInclination(true, true);
01531         return;
01532       }
01533     }
01534   }
01535 
01536   VehicleUpdatePosition(v);
01537   v->UpdateViewport(true, true);
01538 }
01539 
01546 void ReverseTrainSwapVeh(Train *v, int l, int r)
01547 {
01548   Train *a, *b;
01549 
01550   /* locate vehicles to swap */
01551   for (a = v; l != 0; l--) a = a->Next();
01552   for (b = v; r != 0; r--) b = b->Next();
01553 
01554   if (a != b) {
01555     /* swap the hidden bits */
01556     {
01557       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01558       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01559       a->vehstatus = tmp;
01560     }
01561 
01562     Swap(a->track, b->track);
01563     Swap(a->direction, b->direction);
01564     Swap(a->x_pos, b->x_pos);
01565     Swap(a->y_pos, b->y_pos);
01566     Swap(a->tile,  b->tile);
01567     Swap(a->z_pos, b->z_pos);
01568 
01569     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01570 
01571     UpdateStatusAfterSwap(a);
01572     UpdateStatusAfterSwap(b);
01573   } else {
01574     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01575      * This is a little bit redundant way, a->gv_flags will
01576      * be (re)set twice, but it reduces code duplication */
01577     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01578     UpdateStatusAfterSwap(a);
01579   }
01580 }
01581 
01582 
01588 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01589 {
01590   return (v->type == VEH_TRAIN) ? v : NULL;
01591 }
01592 
01593 
01600 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01601 {
01602   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01603 
01604   Train *t = Train::From(v);
01605   if (!t->IsFrontEngine()) return NULL;
01606 
01607   TileIndex tile = *(TileIndex *)data;
01608 
01609   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01610 
01611   return t;
01612 }
01613 
01614 
01621 static bool TrainApproachingCrossing(TileIndex tile)
01622 {
01623   assert(IsLevelCrossingTile(tile));
01624 
01625   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01626   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01627 
01628   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01629 
01630   dir = ReverseDiagDir(dir);
01631   tile_from = tile + TileOffsByDiagDir(dir);
01632 
01633   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01634 }
01635 
01636 
01643 void UpdateLevelCrossing(TileIndex tile, bool sound)
01644 {
01645   assert(IsLevelCrossingTile(tile));
01646 
01647   /* train on crossing || train approaching crossing || reserved */
01648   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01649 
01650   if (new_state != IsCrossingBarred(tile)) {
01651     if (new_state && sound) {
01652       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01653     }
01654     SetCrossingBarred(tile, new_state);
01655     MarkTileDirtyByTile(tile);
01656   }
01657 }
01658 
01659 
01665 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01666 {
01667   if (!IsCrossingBarred(tile)) {
01668     BarCrossing(tile);
01669     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01670     MarkTileDirtyByTile(tile);
01671   }
01672 }
01673 
01674 
01680 static void AdvanceWagonsBeforeSwap(Train *v)
01681 {
01682   Train *base = v;
01683   Train *first = base; // first vehicle to move
01684   Train *last = v->Last(); // last vehicle to move
01685   uint length = CountVehiclesInChain(v);
01686 
01687   while (length > 2) {
01688     last = last->Previous();
01689     first = first->Next();
01690 
01691     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01692 
01693     /* do not update images now
01694      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01695     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01696 
01697     base = first; // == base->Next()
01698     length -= 2;
01699   }
01700 }
01701 
01702 
01708 static void AdvanceWagonsAfterSwap(Train *v)
01709 {
01710   /* first of all, fix the situation when the train was entering a depot */
01711   Train *dep = v; // last vehicle in front of just left depot
01712   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01713     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01714   }
01715 
01716   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01717 
01718   if (leave != NULL) {
01719     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01720     int d = TicksToLeaveDepot(dep);
01721 
01722     if (d <= 0) {
01723       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01724       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01725       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01726     }
01727   } else {
01728     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01729   }
01730 
01731   Train *base = v;
01732   Train *first = base; // first vehicle to move
01733   Train *last = v->Last(); // last vehicle to move
01734   uint length = CountVehiclesInChain(v);
01735 
01736   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01737    * they have already correct spacing, so we have to make sure they are moved how they should */
01738   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01739 
01740   while (length > 2) {
01741     /* we reached vehicle (originally) in front of a depot, stop now
01742      * (we would move wagons that are already moved with new wagon length). */
01743     if (base == dep) break;
01744 
01745     /* the last wagon was that one leaving a depot, so do not move it anymore */
01746     if (last == dep) nomove = true;
01747 
01748     last = last->Previous();
01749     first = first->Next();
01750 
01751     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01752 
01753     /* do not update images now */
01754     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01755 
01756     base = first; // == base->Next()
01757     length -= 2;
01758   }
01759 }
01760 
01765 void ReverseTrainDirection(Train *v)
01766 {
01767   if (IsRailDepotTile(v->tile)) {
01768     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01769   }
01770 
01771   /* Clear path reservation in front if train is not stuck. */
01772   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01773 
01774   /* Check if we were approaching a rail/road-crossing */
01775   TileIndex crossing = TrainApproachingCrossingTile(v);
01776 
01777   /* count number of vehicles */
01778   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01779 
01780   AdvanceWagonsBeforeSwap(v);
01781 
01782   /* swap start<>end, start+1<>end-1, ... */
01783   int l = 0;
01784   do {
01785     ReverseTrainSwapVeh(v, l++, r--);
01786   } while (l <= r);
01787 
01788   AdvanceWagonsAfterSwap(v);
01789 
01790   if (IsRailDepotTile(v->tile)) {
01791     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01792   }
01793 
01794   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01795 
01796   ClrBit(v->flags, VRF_REVERSING);
01797 
01798   /* recalculate cached data */
01799   v->ConsistChanged(true);
01800 
01801   /* update all images */
01802   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01803 
01804   /* update crossing we were approaching */
01805   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01806 
01807   /* maybe we are approaching crossing now, after reversal */
01808   crossing = TrainApproachingCrossingTile(v);
01809   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01810 
01811   /* If we are inside a depot after reversing, don't bother with path reserving. */
01812   if (v->track == TRACK_BIT_DEPOT) {
01813     /* Can't be stuck here as inside a depot is always a safe tile. */
01814     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01815     ClrBit(v->flags, VRF_TRAIN_STUCK);
01816     return;
01817   }
01818 
01819   /* TrainExitDir does not always produce the desired dir for depots and
01820    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01821   DiagDirection dir = TrainExitDir(v->direction, v->track);
01822   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01823 
01824   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01825     /* If we are currently on a tile with conventional signals, we can't treat the
01826      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01827     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01828       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01829       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01830 
01831     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01832     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01833 
01834     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01835     if (TryPathReserve(v, false, first_tile_okay)) {
01836       /* Do a look-ahead now in case our current tile was already a safe tile. */
01837       CheckNextTrainTile(v);
01838     } else if (v->current_order.GetType() != OT_LOADING) {
01839       /* Do not wait for a way out when we're still loading */
01840       MarkTrainAsStuck(v);
01841     }
01842   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01843     /* A train not inside a PBS block can't be stuck. */
01844     ClrBit(v->flags, VRF_TRAIN_STUCK);
01845     v->wait_counter = 0;
01846   }
01847 }
01848 
01858 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01859 {
01860   Train *v = Train::GetIfValid(p1);
01861   if (v == NULL) return CMD_ERROR;
01862 
01863   CommandCost ret = CheckOwnership(v->owner);
01864   if (ret.Failed()) return ret;
01865 
01866   if (p2 != 0) {
01867     /* turn a single unit around */
01868 
01869     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01870       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01871     }
01872     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01873 
01874     Train *front = v->First();
01875     /* make sure the vehicle is stopped in the depot */
01876     if (!front->IsStoppedInDepot()) {
01877       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01878     }
01879 
01880     if (flags & DC_EXEC) {
01881       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01882 
01883       front->ConsistChanged(false);
01884       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01885       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01886       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01887       SetWindowClassesDirty(WC_TRAINS_LIST);
01888     }
01889   } else {
01890     /* turn the whole train around */
01891     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01892 
01893     if (flags & DC_EXEC) {
01894       /* Properly leave the station if we are loading and won't be loading anymore */
01895       if (v->current_order.IsType(OT_LOADING)) {
01896         const Vehicle *last = v;
01897         while (last->Next() != NULL) last = last->Next();
01898 
01899         /* not a station || different station --> leave the station */
01900         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01901           v->LeaveStation();
01902         }
01903       }
01904 
01905       /* We cancel any 'skip signal at dangers' here */
01906       v->force_proceed = TFP_NONE;
01907       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01908 
01909       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01910         ToggleBit(v->flags, VRF_REVERSING);
01911       } else {
01912         v->cur_speed = 0;
01913         v->SetLastSpeed();
01914         HideFillingPercent(&v->fill_percent_te_id);
01915         ReverseTrainDirection(v);
01916       }
01917     }
01918   }
01919   return CommandCost();
01920 }
01921 
01931 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01932 {
01933   Train *t = Train::GetIfValid(p1);
01934   if (t == NULL) return CMD_ERROR;
01935 
01936   CommandCost ret = CheckOwnership(t->owner);
01937   if (ret.Failed()) return ret;
01938 
01939 
01940   if (flags & DC_EXEC) {
01941     /* If we are forced to proceed, cancel that order.
01942      * If we are marked stuck we would want to force the train
01943      * to proceed to the next signal. In the other cases we
01944      * would like to pass the signal at danger and run till the
01945      * next signal we encounter. */
01946     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01947     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01948   }
01949 
01950   return CommandCost();
01951 }
01952 
01960 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01961 {
01962   assert(!(v->vehstatus & VS_CRASHED));
01963 
01964   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01965 
01966   PBSTileInfo origin = FollowTrainReservation(v);
01967   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01968 
01969   switch (_settings_game.pf.pathfinder_for_trains) {
01970     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01971     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01972 
01973     default: NOT_REACHED();
01974   }
01975 }
01976 
01984 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01985 {
01986   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01987   if (tfdd.best_length == UINT_MAX) return false;
01988 
01989   if (location    != NULL) *location    = tfdd.tile;
01990   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01991   if (reverse     != NULL) *reverse     = tfdd.reverse;
01992 
01993   return true;
01994 }
01995 
01997 void Train::PlayLeaveStationSound() const
01998 {
01999   static const SoundFx sfx[] = {
02000     SND_04_TRAIN,
02001     SND_0A_TRAIN_HORN,
02002     SND_0A_TRAIN_HORN,
02003     SND_47_MAGLEV_2,
02004     SND_41_MAGLEV
02005   };
02006 
02007   if (PlayVehicleSound(this, VSE_START)) return;
02008 
02009   EngineID engtype = this->engine_type;
02010   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02011 }
02012 
02017 static void CheckNextTrainTile(Train *v)
02018 {
02019   /* Don't do any look-ahead if path_backoff_interval is 255. */
02020   if (_settings_game.pf.path_backoff_interval == 255) return;
02021 
02022   /* Exit if we are inside a depot. */
02023   if (v->track == TRACK_BIT_DEPOT) return;
02024 
02025   switch (v->current_order.GetType()) {
02026     /* Exit if we reached our destination depot. */
02027     case OT_GOTO_DEPOT:
02028       if (v->tile == v->dest_tile) return;
02029       break;
02030 
02031     case OT_GOTO_WAYPOINT:
02032       /* If we reached our waypoint, make sure we see that. */
02033       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02034       break;
02035 
02036     case OT_NOTHING:
02037     case OT_LEAVESTATION:
02038     case OT_LOADING:
02039       /* Exit if the current order doesn't have a destination, but the train has orders. */
02040       if (v->GetNumOrders() > 0) return;
02041       break;
02042 
02043     default:
02044       break;
02045   }
02046   /* Exit if we are on a station tile and are going to stop. */
02047   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02048 
02049   Trackdir td = v->GetVehicleTrackdir();
02050 
02051   /* On a tile with a red non-pbs signal, don't look ahead. */
02052   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02053       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02054       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02055 
02056   CFollowTrackRail ft(v);
02057   if (!ft.Follow(v->tile, td)) return;
02058 
02059   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02060     /* Next tile is not reserved. */
02061     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02062       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02063         /* If the next tile is a PBS signal, try to make a reservation. */
02064         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02065         if (_settings_game.pf.forbid_90_deg) {
02066           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02067         }
02068         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02069       }
02070     }
02071   }
02072 }
02073 
02079 static bool CheckTrainStayInDepot(Train *v)
02080 {
02081   /* bail out if not all wagons are in the same depot or not in a depot at all */
02082   for (const Train *u = v; u != NULL; u = u->Next()) {
02083     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02084   }
02085 
02086   /* if the train got no power, then keep it in the depot */
02087   if (v->gcache.cached_power == 0) {
02088     v->vehstatus |= VS_STOPPED;
02089     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02090     return true;
02091   }
02092 
02093   SigSegState seg_state;
02094 
02095   if (v->force_proceed == TFP_NONE) {
02096     /* force proceed was not pressed */
02097     if (++v->wait_counter < 37) {
02098       SetWindowClassesDirty(WC_TRAINS_LIST);
02099       return true;
02100     }
02101 
02102     v->wait_counter = 0;
02103 
02104     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02105     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02106       /* Full and no PBS signal in block or depot reserved, can't exit. */
02107       SetWindowClassesDirty(WC_TRAINS_LIST);
02108       return true;
02109     }
02110   } else {
02111     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02112   }
02113 
02114   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02115   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02116     /* We need to have a reservation for this to work. */
02117     if (HasDepotReservation(v->tile)) return true;
02118     SetDepotReservation(v->tile, true);
02119     VehicleEnterDepot(v);
02120     return true;
02121   }
02122 
02123   /* Only leave when we can reserve a path to our destination. */
02124   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02125     /* No path and no force proceed. */
02126     SetWindowClassesDirty(WC_TRAINS_LIST);
02127     MarkTrainAsStuck(v);
02128     return true;
02129   }
02130 
02131   SetDepotReservation(v->tile, true);
02132   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02133 
02134   VehicleServiceInDepot(v);
02135   SetWindowClassesDirty(WC_TRAINS_LIST);
02136   v->PlayLeaveStationSound();
02137 
02138   v->track = TRACK_BIT_X;
02139   if (v->direction & 2) v->track = TRACK_BIT_Y;
02140 
02141   v->vehstatus &= ~VS_HIDDEN;
02142   v->cur_speed = 0;
02143 
02144   v->UpdateViewport(true, true);
02145   VehicleUpdatePosition(v);
02146   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02147   v->UpdateAcceleration();
02148   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02149 
02150   return false;
02151 }
02152 
02159 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02160 {
02161   DiagDirection dir = TrackdirToExitdir(track_dir);
02162 
02163   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02164     /* Are we just leaving a tunnel/bridge? */
02165     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02166       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02167 
02168       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02169         /* Free the reservation only if no other train is on the tiles. */
02170         SetTunnelBridgeReservation(tile, false);
02171         SetTunnelBridgeReservation(end, false);
02172 
02173         if (_settings_client.gui.show_track_reservation) {
02174           MarkTileDirtyByTile(tile);
02175           MarkTileDirtyByTile(end);
02176         }
02177       }
02178     }
02179   } else if (IsRailStationTile(tile)) {
02180     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02181     /* If the new tile is not a further tile of the same station, we
02182      * clear the reservation for the whole platform. */
02183     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02184       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02185     }
02186   } else {
02187     /* Any other tile */
02188     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02189   }
02190 }
02191 
02198 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02199 {
02200   assert(v->IsFrontEngine());
02201 
02202   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02203   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02204   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02205   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02206 
02207   /* Can't be holding a reservation if we enter a depot. */
02208   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02209   if (v->track == TRACK_BIT_DEPOT) {
02210     /* Front engine is in a depot. We enter if some part is not in the depot. */
02211     for (const Train *u = v; u != NULL; u = u->Next()) {
02212       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02213     }
02214   }
02215   /* Don't free reservation if it's not ours. */
02216   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02217 
02218   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02219   while (ft.Follow(tile, td)) {
02220     tile = ft.m_new_tile;
02221     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02222     td = RemoveFirstTrackdir(&bits);
02223     assert(bits == TRACKDIR_BIT_NONE);
02224 
02225     if (!IsValidTrackdir(td)) break;
02226 
02227     if (IsTileType(tile, MP_RAILWAY)) {
02228       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02229         /* Conventional signal along trackdir: remove reservation and stop. */
02230         UnreserveRailTrack(tile, TrackdirToTrack(td));
02231         break;
02232       }
02233       if (HasPbsSignalOnTrackdir(tile, td)) {
02234         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02235           /* Red PBS signal? Can't be our reservation, would be green then. */
02236           break;
02237         } else {
02238           /* Turn the signal back to red. */
02239           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02240           MarkTileDirtyByTile(tile);
02241         }
02242       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02243         break;
02244       }
02245     }
02246 
02247     /* Don't free first station/bridge/tunnel if we are on it. */
02248     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);
02249 
02250     free_tile = true;
02251   }
02252 }
02253 
02254 static const byte _initial_tile_subcoord[6][4][3] = {
02255 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02256 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02257 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02258 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02259 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02260 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02261 };
02262 
02275 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02276 {
02277   switch (_settings_game.pf.pathfinder_for_trains) {
02278     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02279     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02280 
02281     default: NOT_REACHED();
02282   }
02283 }
02284 
02290 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02291 {
02292   PBSTileInfo origin = FollowTrainReservation(v);
02293 
02294   CFollowTrackRail ft(v);
02295 
02296   TileIndex tile = origin.tile;
02297   Trackdir  cur_td = origin.trackdir;
02298   while (ft.Follow(tile, cur_td)) {
02299     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02300       /* Possible signal tile. */
02301       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02302     }
02303 
02304     if (_settings_game.pf.forbid_90_deg) {
02305       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02306       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02307     }
02308 
02309     /* Station, depot or waypoint are a possible target. */
02310     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02311     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02312       /* Choice found or possible target encountered.
02313        * On finding a possible target, we need to stop and let the pathfinder handle the
02314        * remaining path. This is because we don't know if this target is in one of our
02315        * orders, so we might cause pathfinding to fail later on if we find a choice.
02316        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02317        * a wrong path not leading to our next destination. */
02318       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02319 
02320       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02321        * actually starts its search at the first unreserved tile. */
02322       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02323 
02324       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02325       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02326       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02327       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02328     }
02329 
02330     tile = ft.m_new_tile;
02331     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02332 
02333     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02334       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02335       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02336       /* Safe position is all good, path valid and okay. */
02337       return PBSTileInfo(tile, cur_td, true);
02338     }
02339 
02340     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02341   }
02342 
02343   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02344     /* End of line, path valid and okay. */
02345     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02346   }
02347 
02348   /* Sorry, can't reserve path, back out. */
02349   tile = origin.tile;
02350   cur_td = origin.trackdir;
02351   TileIndex stopped = ft.m_old_tile;
02352   Trackdir  stopped_td = ft.m_old_td;
02353   while (tile != stopped || cur_td != stopped_td) {
02354     if (!ft.Follow(tile, cur_td)) break;
02355 
02356     if (_settings_game.pf.forbid_90_deg) {
02357       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02358       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02359     }
02360     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02361 
02362     tile = ft.m_new_tile;
02363     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02364 
02365     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02366   }
02367 
02368   /* Path invalid. */
02369   return PBSTileInfo();
02370 }
02371 
02382 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02383 {
02384   switch (_settings_game.pf.pathfinder_for_trains) {
02385     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02386     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02387 
02388     default: NOT_REACHED();
02389   }
02390 }
02391 
02393 class VehicleOrderSaver {
02394 private:
02395   Train          *v;
02396   Order          old_order;
02397   TileIndex      old_dest_tile;
02398   StationID      old_last_station_visited;
02399   VehicleOrderID index;
02400   bool           suppress_implicit_orders;
02401 
02402 public:
02403   VehicleOrderSaver(Train *_v) :
02404     v(_v),
02405     old_order(_v->current_order),
02406     old_dest_tile(_v->dest_tile),
02407     old_last_station_visited(_v->last_station_visited),
02408     index(_v->cur_real_order_index),
02409     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02410   {
02411   }
02412 
02413   ~VehicleOrderSaver()
02414   {
02415     this->v->current_order = this->old_order;
02416     this->v->dest_tile = this->old_dest_tile;
02417     this->v->last_station_visited = this->old_last_station_visited;
02418     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02419   }
02420 
02426   bool SwitchToNextOrder(bool skip_first)
02427   {
02428     if (this->v->GetNumOrders() == 0) return false;
02429 
02430     if (skip_first) ++this->index;
02431 
02432     int depth = 0;
02433 
02434     do {
02435       /* Wrap around. */
02436       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02437 
02438       Order *order = this->v->GetOrder(this->index);
02439       assert(order != NULL);
02440 
02441       switch (order->GetType()) {
02442         case OT_GOTO_DEPOT:
02443           /* Skip service in depot orders when the train doesn't need service. */
02444           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02445         case OT_GOTO_STATION:
02446         case OT_GOTO_WAYPOINT:
02447           this->v->current_order = *order;
02448           return UpdateOrderDest(this->v, order, 0, true);
02449         case OT_CONDITIONAL: {
02450           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02451           if (next != INVALID_VEH_ORDER_ID) {
02452             depth++;
02453             this->index = next;
02454             /* Don't increment next, so no break here. */
02455             continue;
02456           }
02457           break;
02458         }
02459         default:
02460           break;
02461       }
02462       /* Don't increment inside the while because otherwise conditional
02463        * orders can lead to an infinite loop. */
02464       ++this->index;
02465       depth++;
02466     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02467 
02468     return false;
02469   }
02470 };
02471 
02472 /* choose a track */
02473 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02474 {
02475   Track best_track = INVALID_TRACK;
02476   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02477   bool changed_signal = false;
02478 
02479   assert((tracks & ~TRACK_BIT_MASK) == 0);
02480 
02481   if (got_reservation != NULL) *got_reservation = false;
02482 
02483   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02484   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02485   /* Do we have a suitable reserved track? */
02486   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02487 
02488   /* Quick return in case only one possible track is available */
02489   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02490     Track track = FindFirstTrack(tracks);
02491     /* We need to check for signals only here, as a junction tile can't have signals. */
02492     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02493       do_track_reservation = true;
02494       changed_signal = true;
02495       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02496     } else if (!do_track_reservation) {
02497       return track;
02498     }
02499     best_track = track;
02500   }
02501 
02502   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02503   DiagDirection dest_enterdir = enterdir;
02504   if (do_track_reservation) {
02505     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02506     if (res_dest.tile == INVALID_TILE) {
02507       /* Reservation failed? */
02508       if (mark_stuck) MarkTrainAsStuck(v);
02509       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02510       return FindFirstTrack(tracks);
02511     }
02512     if (res_dest.okay) {
02513       /* Got a valid reservation that ends at a safe target, quick exit. */
02514       if (got_reservation != NULL) *got_reservation = true;
02515       if (changed_signal) MarkTileDirtyByTile(tile);
02516       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02517       return best_track;
02518     }
02519 
02520     /* Check if the train needs service here, so it has a chance to always find a depot.
02521      * Also check if the current order is a service order so we don't reserve a path to
02522      * the destination but instead to the next one if service isn't needed. */
02523     CheckIfTrainNeedsService(v);
02524     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02525   }
02526 
02527   /* Save the current train order. The destructor will restore the old order on function exit. */
02528   VehicleOrderSaver orders(v);
02529 
02530   /* If the current tile is the destination of the current order and
02531    * a reservation was requested, advance to the next order.
02532    * Don't advance on a depot order as depots are always safe end points
02533    * for a path and no look-ahead is necessary. This also avoids a
02534    * problem with depot orders not part of the order list when the
02535    * order list itself is empty. */
02536   if (v->current_order.IsType(OT_LEAVESTATION)) {
02537     orders.SwitchToNextOrder(false);
02538   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02539       v->current_order.IsType(OT_GOTO_STATION) ?
02540       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02541       v->tile == v->dest_tile))) {
02542     orders.SwitchToNextOrder(true);
02543   }
02544 
02545   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02546     /* Pathfinders are able to tell that route was only 'guessed'. */
02547     bool      path_found = true;
02548     TileIndex new_tile = res_dest.tile;
02549 
02550     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02551     if (new_tile == tile) best_track = next_track;
02552     v->HandlePathfindingResult(path_found);
02553   }
02554 
02555   /* No track reservation requested -> finished. */
02556   if (!do_track_reservation) return best_track;
02557 
02558   /* A path was found, but could not be reserved. */
02559   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02560     if (mark_stuck) MarkTrainAsStuck(v);
02561     FreeTrainTrackReservation(v);
02562     return best_track;
02563   }
02564 
02565   /* No possible reservation target found, we are probably lost. */
02566   if (res_dest.tile == INVALID_TILE) {
02567     /* Try to find any safe destination. */
02568     PBSTileInfo origin = FollowTrainReservation(v);
02569     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02570       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02571       best_track = FindFirstTrack(res);
02572       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02573       if (got_reservation != NULL) *got_reservation = true;
02574       if (changed_signal) MarkTileDirtyByTile(tile);
02575     } else {
02576       FreeTrainTrackReservation(v);
02577       if (mark_stuck) MarkTrainAsStuck(v);
02578     }
02579     return best_track;
02580   }
02581 
02582   if (got_reservation != NULL) *got_reservation = true;
02583 
02584   /* Reservation target found and free, check if it is safe. */
02585   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02586     /* Extend reservation until we have found a safe position. */
02587     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02588     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02589     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02590     if (_settings_game.pf.forbid_90_deg) {
02591       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02592     }
02593 
02594     /* Get next order with destination. */
02595     if (orders.SwitchToNextOrder(true)) {
02596       PBSTileInfo cur_dest;
02597       bool path_found;
02598       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02599       if (cur_dest.tile != INVALID_TILE) {
02600         res_dest = cur_dest;
02601         if (res_dest.okay) continue;
02602         /* Path found, but could not be reserved. */
02603         FreeTrainTrackReservation(v);
02604         if (mark_stuck) MarkTrainAsStuck(v);
02605         if (got_reservation != NULL) *got_reservation = false;
02606         changed_signal = false;
02607         break;
02608       }
02609     }
02610     /* No order or no safe position found, try any position. */
02611     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02612       FreeTrainTrackReservation(v);
02613       if (mark_stuck) MarkTrainAsStuck(v);
02614       if (got_reservation != NULL) *got_reservation = false;
02615       changed_signal = false;
02616     }
02617     break;
02618   }
02619 
02620   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02621 
02622   if (changed_signal) MarkTileDirtyByTile(tile);
02623 
02624   return best_track;
02625 }
02626 
02635 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02636 {
02637   assert(v->IsFrontEngine());
02638 
02639   /* We have to handle depots specially as the track follower won't look
02640    * at the depot tile itself but starts from the next tile. If we are still
02641    * inside the depot, a depot reservation can never be ours. */
02642   if (v->track == TRACK_BIT_DEPOT) {
02643     if (HasDepotReservation(v->tile)) {
02644       if (mark_as_stuck) MarkTrainAsStuck(v);
02645       return false;
02646     } else {
02647       /* Depot not reserved, but the next tile might be. */
02648       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02649       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02650     }
02651   }
02652 
02653   Vehicle *other_train = NULL;
02654   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02655   /* The path we are driving on is already blocked by some other train.
02656    * This can only happen in certain situations when mixing path and
02657    * block signals or when changing tracks and/or signals.
02658    * Exit here as doing any further reservations will probably just
02659    * make matters worse. */
02660   if (other_train != NULL && other_train->index != v->index) {
02661     if (mark_as_stuck) MarkTrainAsStuck(v);
02662     return false;
02663   }
02664   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02665   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02666     /* Can't be stuck then. */
02667     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02668     ClrBit(v->flags, VRF_TRAIN_STUCK);
02669     return true;
02670   }
02671 
02672   /* If we are in a depot, tentatively reserve the depot. */
02673   if (v->track == TRACK_BIT_DEPOT) {
02674     SetDepotReservation(v->tile, true);
02675     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02676   }
02677 
02678   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02679   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02680   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02681 
02682   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02683 
02684   bool res_made = false;
02685   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02686 
02687   if (!res_made) {
02688     /* Free the depot reservation as well. */
02689     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02690     return false;
02691   }
02692 
02693   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02694     v->wait_counter = 0;
02695     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02696   }
02697   ClrBit(v->flags, VRF_TRAIN_STUCK);
02698   return true;
02699 }
02700 
02701 
02702 static bool CheckReverseTrain(const Train *v)
02703 {
02704   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02705       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02706       !(v->direction & 1)) {
02707     return false;
02708   }
02709 
02710   assert(v->track != TRACK_BIT_NONE);
02711 
02712   switch (_settings_game.pf.pathfinder_for_trains) {
02713     case VPF_NPF: return NPFTrainCheckReverse(v);
02714     case VPF_YAPF: return YapfTrainCheckReverse(v);
02715 
02716     default: NOT_REACHED();
02717   }
02718 }
02719 
02725 TileIndex Train::GetOrderStationLocation(StationID station)
02726 {
02727   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02728 
02729   const Station *st = Station::Get(station);
02730   if (!(st->facilities & FACIL_TRAIN)) {
02731     /* The destination station has no trainstation tiles. */
02732     this->IncrementRealOrderIndex();
02733     return 0;
02734   }
02735 
02736   return st->xy;
02737 }
02738 
02740 void Train::MarkDirty()
02741 {
02742   Train *v = this;
02743   do {
02744     v->UpdateViewport(false, false);
02745   } while ((v = v->Next()) != NULL);
02746 
02747   /* need to update acceleration and cached values since the goods on the train changed. */
02748   this->CargoChanged();
02749   this->UpdateAcceleration();
02750 }
02751 
02759 int Train::UpdateSpeed()
02760 {
02761   switch (_settings_game.vehicle.train_acceleration_model) {
02762     default: NOT_REACHED();
02763     case AM_ORIGINAL:
02764       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, min(this->gcache.cached_max_track_speed, this->current_order.max_speed));
02765 
02766     case AM_REALISTIC:
02767       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02768   }
02769 }
02770 
02776 static void TrainEnterStation(Train *v, StationID station)
02777 {
02778   v->last_station_visited = station;
02779 
02780   /* check if a train ever visited this station before */
02781   Station *st = Station::Get(station);
02782   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02783     st->had_vehicle_of_type |= HVOT_TRAIN;
02784     SetDParam(0, st->index);
02785     AddVehicleNewsItem(
02786       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02787       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
02788       v->index,
02789       st->index
02790     );
02791     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02792     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02793   }
02794 
02795   v->force_proceed = TFP_NONE;
02796   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02797 
02798   v->BeginLoading();
02799 
02800   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02801 }
02802 
02803 /* Check if the vehicle is compatible with the specified tile */
02804 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02805 {
02806   return IsTileOwner(tile, v->owner) &&
02807       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02808 }
02809 
02811 struct AccelerationSlowdownParams {
02812   byte small_turn; 
02813   byte large_turn; 
02814   byte z_up;       
02815   byte z_down;     
02816 };
02817 
02819 static const AccelerationSlowdownParams _accel_slowdown[] = {
02820   /* normal accel */
02821   {256 / 4, 256 / 2, 256 / 4, 2}, 
02822   {256 / 4, 256 / 2, 256 / 4, 2}, 
02823   {0,       256 / 2, 256 / 4, 2}, 
02824 };
02825 
02831 static inline void AffectSpeedByZChange(Train *v, int old_z)
02832 {
02833   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02834 
02835   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02836 
02837   if (old_z < v->z_pos) {
02838     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02839   } else {
02840     uint16 spd = v->cur_speed + asp->z_down;
02841     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02842   }
02843 }
02844 
02845 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02846 {
02847   if (IsTileType(tile, MP_RAILWAY) &&
02848       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02849     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02850     Trackdir trackdir = FindFirstTrackdir(tracks);
02851     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02852       /* A PBS block with a non-PBS signal facing us? */
02853       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02854     }
02855   }
02856   return false;
02857 }
02858 
02860 void Train::ReserveTrackUnderConsist() const
02861 {
02862   for (const Train *u = this; u != NULL; u = u->Next()) {
02863     switch (u->track) {
02864       case TRACK_BIT_WORMHOLE:
02865         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02866         break;
02867       case TRACK_BIT_DEPOT:
02868         break;
02869       default:
02870         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02871         break;
02872     }
02873   }
02874 }
02875 
02882 uint Train::Crash(bool flooded)
02883 {
02884   uint pass = 0;
02885   if (this->IsFrontEngine()) {
02886     pass += 2; // driver
02887 
02888     /* Remove the reserved path in front of the train if it is not stuck.
02889      * Also clear all reserved tracks the train is currently on. */
02890     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02891     for (const Train *v = this; v != NULL; v = v->Next()) {
02892       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02893       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02894         /* ClearPathReservation will not free the wormhole exit
02895          * if the train has just entered the wormhole. */
02896         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02897       }
02898     }
02899 
02900     /* we may need to update crossing we were approaching,
02901      * but must be updated after the train has been marked crashed */
02902     TileIndex crossing = TrainApproachingCrossingTile(this);
02903     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02904 
02905     /* Remove the loading indicators (if any) */
02906     HideFillingPercent(&this->fill_percent_te_id);
02907   }
02908 
02909   pass += this->GroundVehicleBase::Crash(flooded);
02910 
02911   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02912   return pass;
02913 }
02914 
02921 static uint TrainCrashed(Train *v)
02922 {
02923   uint num = 0;
02924 
02925   /* do not crash train twice */
02926   if (!(v->vehstatus & VS_CRASHED)) {
02927     num = v->Crash();
02928     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02929     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02930   }
02931 
02932   /* Try to re-reserve track under already crashed train too.
02933    * Crash() clears the reservation! */
02934   v->ReserveTrackUnderConsist();
02935 
02936   return num;
02937 }
02938 
02940 struct TrainCollideChecker {
02941   Train *v; 
02942   uint num; 
02943 };
02944 
02951 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02952 {
02953   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02954 
02955   /* not a train or in depot */
02956   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02957 
02958   /* do not crash into trains of another company. */
02959   if (v->owner != tcc->v->owner) return NULL;
02960 
02961   /* get first vehicle now to make most usual checks faster */
02962   Train *coll = Train::From(v)->First();
02963 
02964   /* can't collide with own wagons */
02965   if (coll == tcc->v) return NULL;
02966 
02967   int x_diff = v->x_pos - tcc->v->x_pos;
02968   int y_diff = v->y_pos - tcc->v->y_pos;
02969 
02970   /* Do fast calculation to check whether trains are not in close vicinity
02971    * and quickly reject trains distant enough for any collision.
02972    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02973    * Differences are then ORed and then we check for any higher bits */
02974   uint hash = (y_diff + 7) | (x_diff + 7);
02975   if (hash & ~15) return NULL;
02976 
02977   /* Slower check using multiplication */
02978   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02979   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02980 
02981   /* Happens when there is a train under bridge next to bridge head */
02982   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02983 
02984   /* crash both trains */
02985   tcc->num += TrainCrashed(tcc->v);
02986   tcc->num += TrainCrashed(coll);
02987 
02988   return NULL; // continue searching
02989 }
02990 
02998 static bool CheckTrainCollision(Train *v)
02999 {
03000   /* can't collide in depot */
03001   if (v->track == TRACK_BIT_DEPOT) return false;
03002 
03003   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03004 
03005   TrainCollideChecker tcc;
03006   tcc.v = v;
03007   tcc.num = 0;
03008 
03009   /* find colliding vehicles */
03010   if (v->track == TRACK_BIT_WORMHOLE) {
03011     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03012     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03013   } else {
03014     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03015   }
03016 
03017   /* any dead -> no crash */
03018   if (tcc.num == 0) return false;
03019 
03020   SetDParam(0, tcc.num);
03021   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH,
03022     NS_ACCIDENT,
03023     v->index
03024   );
03025 
03026   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03027   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03028   return true;
03029 }
03030 
03031 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03032 {
03033   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03034 
03035   Train *t = Train::From(v);
03036   DiagDirection exitdir = *(DiagDirection *)data;
03037 
03038   /* not front engine of a train, inside wormhole or depot, crashed */
03039   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03040 
03041   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03042 
03043   return t;
03044 }
03045 
03053 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03054 {
03055   Train *first = v->First();
03056   Train *prev;
03057   bool direction_changed = false; // has direction of any part changed?
03058 
03059   /* For every vehicle after and including the given vehicle */
03060   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03061     DiagDirection enterdir = DIAGDIR_BEGIN;
03062     bool update_signals_crossing = false; // will we update signals or crossing state?
03063 
03064     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03065     if (v->track != TRACK_BIT_WORMHOLE) {
03066       /* Not inside tunnel */
03067       if (gp.old_tile == gp.new_tile) {
03068         /* Staying in the old tile */
03069         if (v->track == TRACK_BIT_DEPOT) {
03070           /* Inside depot */
03071           gp.x = v->x_pos;
03072           gp.y = v->y_pos;
03073         } else {
03074           /* Not inside depot */
03075 
03076           /* Reverse when we are at the end of the track already, do not move to the new position */
03077           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03078 
03079           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03080           if (HasBit(r, VETS_CANNOT_ENTER)) {
03081             goto invalid_rail;
03082           }
03083           if (HasBit(r, VETS_ENTERED_STATION)) {
03084             /* The new position is the end of the platform */
03085             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03086           }
03087         }
03088       } else {
03089         /* A new tile is about to be entered. */
03090 
03091         /* Determine what direction we're entering the new tile from */
03092         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03093         assert(IsValidDiagDirection(enterdir));
03094 
03095         /* Get the status of the tracks in the new tile and mask
03096          * away the bits that aren't reachable. */
03097         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03098         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03099 
03100         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03101         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03102 
03103         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03104         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03105           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03106            * can be switched on halfway a turn */
03107           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03108         }
03109 
03110         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03111 
03112         /* Check if the new tile constrains tracks that are compatible
03113          * with the current train, if not, bail out. */
03114         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03115 
03116         TrackBits chosen_track;
03117         if (prev == NULL) {
03118           /* Currently the locomotive is active. Determine which one of the
03119            * available tracks to choose */
03120           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03121           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03122 
03123           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03124             /* For each signal we find decrease the counter by one.
03125              * We start at two, so the first signal we pass decreases
03126              * this to one, then if we reach the next signal it is
03127              * decreased to zero and we won't pass that new signal. */
03128             Trackdir dir = FindFirstTrackdir(trackdirbits);
03129             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03130                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03131               /* However, we do not want to be stopped by PBS signals
03132                * entered via the back. */
03133               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03134               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03135             }
03136           }
03137 
03138           /* Check if it's a red signal and that force proceed is not clicked. */
03139           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03140             /* In front of a red signal */
03141             Trackdir i = FindFirstTrackdir(trackdirbits);
03142 
03143             /* Don't handle stuck trains here. */
03144             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03145 
03146             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03147               v->cur_speed = 0;
03148               v->subspeed = 0;
03149               v->progress = 255 - 100;
03150               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03151             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03152               v->cur_speed = 0;
03153               v->subspeed = 0;
03154               v->progress = 255 - 10;
03155               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03156                 DiagDirection exitdir = TrackdirToExitdir(i);
03157                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03158 
03159                 exitdir = ReverseDiagDir(exitdir);
03160 
03161                 /* check if a train is waiting on the other side */
03162                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03163               }
03164             }
03165 
03166             /* If we would reverse but are currently in a PBS block and
03167              * reversing of stuck trains is disabled, don't reverse.
03168              * This does not apply if the reason for reversing is a one-way
03169              * signal blocking us, because a train would then be stuck forever. */
03170             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03171                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03172               v->wait_counter = 0;
03173               return false;
03174             }
03175             goto reverse_train_direction;
03176           } else {
03177             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03178           }
03179         } else {
03180           /* The wagon is active, simply follow the prev vehicle. */
03181           if (prev->tile == gp.new_tile) {
03182             /* Choose the same track as prev */
03183             if (prev->track == TRACK_BIT_WORMHOLE) {
03184               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03185                * However, just choose the track into the wormhole. */
03186               assert(IsTunnel(prev->tile));
03187               chosen_track = bits;
03188             } else {
03189               chosen_track = prev->track;
03190             }
03191           } else {
03192             /* Choose the track that leads to the tile where prev is.
03193              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03194              * I.e. when the tile between them has only space for a single vehicle like
03195              *  1) horizontal/vertical track tiles and
03196              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03197              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03198              */
03199             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03200               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03201               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03202               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03203               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03204             };
03205             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03206             assert(IsValidDiagDirection(exitdir));
03207             chosen_track = _connecting_track[enterdir][exitdir];
03208           }
03209           chosen_track &= bits;
03210         }
03211 
03212         /* Make sure chosen track is a valid track */
03213         assert(
03214             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03215             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03216             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03217 
03218         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03219         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03220         gp.x = (gp.x & ~0xF) | b[0];
03221         gp.y = (gp.y & ~0xF) | b[1];
03222         Direction chosen_dir = (Direction)b[2];
03223 
03224         /* Call the landscape function and tell it that the vehicle entered the tile */
03225         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03226         if (HasBit(r, VETS_CANNOT_ENTER)) {
03227           goto invalid_rail;
03228         }
03229 
03230         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03231           Track track = FindFirstTrack(chosen_track);
03232           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03233           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03234             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03235             MarkTileDirtyByTile(gp.new_tile);
03236           }
03237 
03238           /* Clear any track reservation when the last vehicle leaves the tile */
03239           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03240 
03241           v->tile = gp.new_tile;
03242 
03243           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03244             v->First()->ConsistChanged(true);
03245           }
03246 
03247           v->track = chosen_track;
03248           assert(v->track);
03249         }
03250 
03251         /* We need to update signal status, but after the vehicle position hash
03252          * has been updated by UpdateInclination() */
03253         update_signals_crossing = true;
03254 
03255         if (chosen_dir != v->direction) {
03256           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03257             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03258             DirDiff diff = DirDifference(v->direction, chosen_dir);
03259             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03260           }
03261           direction_changed = true;
03262           v->direction = chosen_dir;
03263         }
03264 
03265         if (v->IsFrontEngine()) {
03266           v->wait_counter = 0;
03267 
03268           /* If we are approaching a crossing that is reserved, play the sound now. */
03269           TileIndex crossing = TrainApproachingCrossingTile(v);
03270           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03271 
03272           /* Always try to extend the reservation when entering a tile. */
03273           CheckNextTrainTile(v);
03274         }
03275 
03276         if (HasBit(r, VETS_ENTERED_STATION)) {
03277           /* The new position is the location where we want to stop */
03278           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03279         }
03280       }
03281     } else {
03282       /* In a tunnel or on a bridge
03283        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03284        * - for bridges, only the middle part - without the bridge heads */
03285       if (!(v->vehstatus & VS_HIDDEN)) {
03286         Train *first = v->First();
03287         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03288       }
03289 
03290       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03291         /* Perform look-ahead on tunnel exit. */
03292         if (v->IsFrontEngine()) {
03293           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03294           CheckNextTrainTile(v);
03295         }
03296         /* Prevent v->UpdateInclination() being called with wrong parameters.
03297          * This could happen if the train was reversed inside the tunnel/bridge. */
03298         if (gp.old_tile == gp.new_tile) {
03299           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03300         }
03301       } else {
03302         v->x_pos = gp.x;
03303         v->y_pos = gp.y;
03304         VehicleUpdatePosition(v);
03305         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03306         continue;
03307       }
03308     }
03309 
03310     /* update image of train, as well as delta XY */
03311     v->UpdateDeltaXY(v->direction);
03312 
03313     v->x_pos = gp.x;
03314     v->y_pos = gp.y;
03315     VehicleUpdatePosition(v);
03316 
03317     /* update the Z position of the vehicle */
03318     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03319 
03320     if (prev == NULL) {
03321       /* This is the first vehicle in the train */
03322       AffectSpeedByZChange(v, old_z);
03323     }
03324 
03325     if (update_signals_crossing) {
03326       if (v->IsFrontEngine()) {
03327         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03328           /* We are entering a block with PBS signals right now, but
03329            * not through a PBS signal. This means we don't have a
03330            * reservation right now. As a conventional signal will only
03331            * ever be green if no other train is in the block, getting
03332            * a path should always be possible. If the player built
03333            * such a strange network that it is not possible, the train
03334            * will be marked as stuck and the player has to deal with
03335            * the problem. */
03336           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03337               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03338               !TryPathReserve(v)) {
03339             MarkTrainAsStuck(v);
03340           }
03341         }
03342       }
03343 
03344       /* Signals can only change when the first
03345        * (above) or the last vehicle moves. */
03346       if (v->Next() == NULL) {
03347         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03348         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03349       }
03350     }
03351 
03352     /* Do not check on every tick to save some computing time. */
03353     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03354   }
03355 
03356   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03357 
03358   return true;
03359 
03360 invalid_rail:
03361   /* We've reached end of line?? */
03362   if (prev != NULL) error("Disconnecting train");
03363 
03364 reverse_train_direction:
03365   if (reverse) {
03366     v->wait_counter = 0;
03367     v->cur_speed = 0;
03368     v->subspeed = 0;
03369     ReverseTrainDirection(v);
03370   }
03371 
03372   return false;
03373 }
03374 
03381 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03382 {
03383   TrackBits *trackbits = (TrackBits *)data;
03384 
03385   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03386     TrackBits train_tbits = Train::From(v)->track;
03387     if (train_tbits == TRACK_BIT_WORMHOLE) {
03388       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03389       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03390     } else if (train_tbits != TRACK_BIT_DEPOT) {
03391       *trackbits |= train_tbits;
03392     }
03393   }
03394 
03395   return NULL;
03396 }
03397 
03405 static void DeleteLastWagon(Train *v)
03406 {
03407   Train *first = v->First();
03408 
03409   /* Go to the last wagon and delete the link pointing there
03410    * *u is then the one-before-last wagon, and *v the last
03411    * one which will physically be removed */
03412   Train *u = v;
03413   for (; v->Next() != NULL; v = v->Next()) u = v;
03414   u->SetNext(NULL);
03415 
03416   if (first != v) {
03417     /* Recalculate cached train properties */
03418     first->ConsistChanged(false);
03419     /* Update the depot window if the first vehicle is in depot -
03420      * if v == first, then it is updated in PreDestructor() */
03421     if (first->track == TRACK_BIT_DEPOT) {
03422       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03423     }
03424   }
03425 
03426   /* 'v' shouldn't be accessed after it has been deleted */
03427   TrackBits trackbits = v->track;
03428   TileIndex tile = v->tile;
03429   Owner owner = v->owner;
03430 
03431   delete v;
03432   v = NULL; // make sure nobody will try to read 'v' anymore
03433 
03434   if (trackbits == TRACK_BIT_WORMHOLE) {
03435     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03436     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03437   }
03438 
03439   Track track = TrackBitsToTrack(trackbits);
03440   if (HasReservedTracks(tile, trackbits)) {
03441     UnreserveRailTrack(tile, track);
03442 
03443     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03444     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03445     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03446 
03447     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03448     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03449     Track t;
03450     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03451   }
03452 
03453   /* check if the wagon was on a road/rail-crossing */
03454   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03455 
03456   /* Update signals */
03457   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03458     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03459   } else {
03460     SetSignalsOnBothDir(tile, track, owner);
03461   }
03462 }
03463 
03468 static void ChangeTrainDirRandomly(Train *v)
03469 {
03470   static const DirDiff delta[] = {
03471     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03472   };
03473 
03474   do {
03475     /* We don't need to twist around vehicles if they're not visible */
03476     if (!(v->vehstatus & VS_HIDDEN)) {
03477       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03478       v->UpdateDeltaXY(v->direction);
03479       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03480       /* Refrain from updating the z position of the vehicle when on
03481        * a bridge, because UpdateInclination() will put the vehicle under
03482        * the bridge in that case */
03483       if (v->track != TRACK_BIT_WORMHOLE) {
03484         VehicleUpdatePosition(v);
03485         v->UpdateInclination(false, false);
03486       }
03487     }
03488   } while ((v = v->Next()) != NULL);
03489 }
03490 
03496 static bool HandleCrashedTrain(Train *v)
03497 {
03498   int state = ++v->crash_anim_pos;
03499 
03500   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03501     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03502   }
03503 
03504   uint32 r;
03505   if (state <= 200 && Chance16R(1, 7, r)) {
03506     int index = (r * 10 >> 16);
03507 
03508     Vehicle *u = v;
03509     do {
03510       if (--index < 0) {
03511         r = Random();
03512 
03513         CreateEffectVehicleRel(u,
03514           GB(r,  8, 3) + 2,
03515           GB(r, 16, 3) + 2,
03516           GB(r,  0, 3) + 5,
03517           EV_EXPLOSION_SMALL);
03518         break;
03519       }
03520     } while ((u = u->Next()) != NULL);
03521   }
03522 
03523   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03524 
03525   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03526     bool ret = v->Next() != NULL;
03527     DeleteLastWagon(v);
03528     return ret;
03529   }
03530 
03531   return true;
03532 }
03533 
03535 static const uint16 _breakdown_speeds[16] = {
03536   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03537 };
03538 
03539 
03548 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03549 {
03550   /* Calc position within the current tile */
03551   uint x = v->x_pos & 0xF;
03552   uint y = v->y_pos & 0xF;
03553 
03554   /* for diagonal directions, 'x' will be 0..15 -
03555    * for other directions, it will be 1, 3, 5, ..., 15 */
03556   switch (v->direction) {
03557     case DIR_N : x = ~x + ~y + 25; break;
03558     case DIR_NW: x = y;            // FALL THROUGH
03559     case DIR_NE: x = ~x + 16;      break;
03560     case DIR_E : x = ~x + y + 9;   break;
03561     case DIR_SE: x = y;            break;
03562     case DIR_S : x = x + y - 7;    break;
03563     case DIR_W : x = ~y + x + 9;   break;
03564     default: break;
03565   }
03566 
03567   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03568    * does not cross the tile boundary when we do reverse, but as the vehicle's
03569    * location is based on their center, use half a vehicle's length as offset.
03570    * Multiply the half-length by two for straight directions to compensate that
03571    * we only get odd x offsets there. */
03572   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03573     /* we are too near the tile end, reverse now */
03574     v->cur_speed = 0;
03575     if (reverse) ReverseTrainDirection(v);
03576     return false;
03577   }
03578 
03579   /* slow down */
03580   v->vehstatus |= VS_TRAIN_SLOWING;
03581   uint16 break_speed = _breakdown_speeds[x & 0xF];
03582   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03583 
03584   return true;
03585 }
03586 
03587 
03593 static bool TrainCanLeaveTile(const Train *v)
03594 {
03595   /* Exit if inside a tunnel/bridge or a depot */
03596   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03597 
03598   TileIndex tile = v->tile;
03599 
03600   /* entering a tunnel/bridge? */
03601   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03602     DiagDirection dir = GetTunnelBridgeDirection(tile);
03603     if (DiagDirToDir(dir) == v->direction) return false;
03604   }
03605 
03606   /* entering a depot? */
03607   if (IsRailDepotTile(tile)) {
03608     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03609     if (DiagDirToDir(dir) == v->direction) return false;
03610   }
03611 
03612   return true;
03613 }
03614 
03615 
03623 static TileIndex TrainApproachingCrossingTile(const Train *v)
03624 {
03625   assert(v->IsFrontEngine());
03626   assert(!(v->vehstatus & VS_CRASHED));
03627 
03628   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03629 
03630   DiagDirection dir = TrainExitDir(v->direction, v->track);
03631   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03632 
03633   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03634   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03635       !CheckCompatibleRail(v, tile)) {
03636     return INVALID_TILE;
03637   }
03638 
03639   return tile;
03640 }
03641 
03642 
03650 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03651 {
03652   /* First, handle broken down train */
03653 
03654   int t = v->breakdown_ctr;
03655   if (t > 1) {
03656     v->vehstatus |= VS_TRAIN_SLOWING;
03657 
03658     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03659     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03660   } else {
03661     v->vehstatus &= ~VS_TRAIN_SLOWING;
03662   }
03663 
03664   if (!TrainCanLeaveTile(v)) return true;
03665 
03666   /* Determine the non-diagonal direction in which we will exit this tile */
03667   DiagDirection dir = TrainExitDir(v->direction, v->track);
03668   /* Calculate next tile */
03669   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03670 
03671   /* Determine the track status on the next tile */
03672   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03673   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03674 
03675   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03676   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03677 
03678   /* We are sure the train is not entering a depot, it is detected above */
03679 
03680   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03681   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03682   if (_settings_game.pf.forbid_90_deg) {
03683     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03684   }
03685 
03686   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03687   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03688     return TrainApproachingLineEnd(v, false, reverse);
03689   }
03690 
03691   /* approaching red signal */
03692   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03693 
03694   /* approaching a rail/road crossing? then make it red */
03695   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03696 
03697   return true;
03698 }
03699 
03700 
03701 static bool TrainLocoHandler(Train *v, bool mode)
03702 {
03703   /* train has crashed? */
03704   if (v->vehstatus & VS_CRASHED) {
03705     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03706   }
03707 
03708   if (v->force_proceed != TFP_NONE) {
03709     ClrBit(v->flags, VRF_TRAIN_STUCK);
03710     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03711   }
03712 
03713   /* train is broken down? */
03714   if (v->HandleBreakdown()) return true;
03715 
03716   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03717     ReverseTrainDirection(v);
03718   }
03719 
03720   /* exit if train is stopped */
03721   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03722 
03723   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03724   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03725     v->wait_counter = 0;
03726     v->cur_speed = 0;
03727     v->subspeed = 0;
03728     ClrBit(v->flags, VRF_LEAVING_STATION);
03729     ReverseTrainDirection(v);
03730     return true;
03731   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03732     /* Try to reserve a path when leaving the station as we
03733      * might not be marked as wanting a reservation, e.g.
03734      * when an overlength train gets turned around in a station. */
03735     DiagDirection dir = TrainExitDir(v->direction, v->track);
03736     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03737 
03738     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03739       TryPathReserve(v, true, true);
03740     }
03741     ClrBit(v->flags, VRF_LEAVING_STATION);
03742   }
03743 
03744   v->HandleLoading(mode);
03745 
03746   if (v->current_order.IsType(OT_LOADING)) return true;
03747 
03748   if (CheckTrainStayInDepot(v)) return true;
03749 
03750   if (!mode) v->ShowVisualEffect();
03751 
03752   /* We had no order but have an order now, do look ahead. */
03753   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03754     CheckNextTrainTile(v);
03755   }
03756 
03757   /* Handle stuck trains. */
03758   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03759     ++v->wait_counter;
03760 
03761     /* Should we try reversing this tick if still stuck? */
03762     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03763 
03764     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03765     if (!TryPathReserve(v)) {
03766       /* Still stuck. */
03767       if (turn_around) ReverseTrainDirection(v);
03768 
03769       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03770         /* Show message to player. */
03771         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03772           SetDParam(0, v->index);
03773           AddVehicleNewsItem(
03774             STR_NEWS_TRAIN_IS_STUCK,
03775             NS_ADVICE,
03776             v->index
03777           );
03778         }
03779         v->wait_counter = 0;
03780       }
03781       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03782       if (v->force_proceed == TFP_NONE) return true;
03783       ClrBit(v->flags, VRF_TRAIN_STUCK);
03784       v->wait_counter = 0;
03785       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03786     }
03787   }
03788 
03789   if (v->current_order.IsType(OT_LEAVESTATION)) {
03790     v->current_order.Free();
03791     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03792     return true;
03793   }
03794 
03795   int j = v->UpdateSpeed();
03796 
03797   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03798   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03799     /* If we manually stopped, we're not force-proceeding anymore. */
03800     v->force_proceed = TFP_NONE;
03801     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03802   }
03803 
03804   int adv_spd = v->GetAdvanceDistance();
03805   if (j < adv_spd) {
03806     /* if the vehicle has speed 0, update the last_speed field. */
03807     if (v->cur_speed == 0) v->SetLastSpeed();
03808   } else {
03809     TrainCheckIfLineEnds(v);
03810     /* Loop until the train has finished moving. */
03811     for (;;) {
03812       j -= adv_spd;
03813       TrainController(v, NULL);
03814       /* Don't continue to move if the train crashed. */
03815       if (CheckTrainCollision(v)) break;
03816       /* Determine distance to next map position */
03817       adv_spd = v->GetAdvanceDistance();
03818 
03819       /* No more moving this tick */
03820       if (j < adv_spd || v->cur_speed == 0) break;
03821 
03822       OrderType order_type = v->current_order.GetType();
03823       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03824       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03825             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03826             IsTileType(v->tile, MP_STATION) &&
03827             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03828         ProcessOrders(v);
03829       }
03830     }
03831     v->SetLastSpeed();
03832   }
03833 
03834   for (Train *u = v; u != NULL; u = u->Next()) {
03835     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03836 
03837     u->UpdateViewport(false, false);
03838   }
03839 
03840   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03841 
03842   return true;
03843 }
03844 
03849 Money Train::GetRunningCost() const
03850 {
03851   Money cost = 0;
03852   const Train *v = this;
03853 
03854   do {
03855     const Engine *e = v->GetEngine();
03856     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03857 
03858     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03859     if (cost_factor == 0) continue;
03860 
03861     /* Halve running cost for multiheaded parts */
03862     if (v->IsMultiheaded()) cost_factor /= 2;
03863 
03864     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03865   } while ((v = v->GetNextVehicle()) != NULL);
03866 
03867   return cost;
03868 }
03869 
03874 bool Train::Tick()
03875 {
03876   this->tick_counter++;
03877 
03878   if (this->IsFrontEngine()) {
03879     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03880 
03881     this->current_order_time++;
03882 
03883     if (!TrainLocoHandler(this, false)) return false;
03884 
03885     return TrainLocoHandler(this, true);
03886   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03887     /* Delete flooded standalone wagon chain */
03888     if (++this->crash_anim_pos >= 4400) {
03889       delete this;
03890       return false;
03891     }
03892   }
03893 
03894   return true;
03895 }
03896 
03901 static void CheckIfTrainNeedsService(Train *v)
03902 {
03903   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03904   if (v->IsInDepot()) {
03905     VehicleServiceInDepot(v);
03906     return;
03907   }
03908 
03909   uint max_penalty;
03910   switch (_settings_game.pf.pathfinder_for_trains) {
03911     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03912     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03913     default: NOT_REACHED();
03914   }
03915 
03916   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03917   /* Only go to the depot if it is not too far out of our way. */
03918   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03919     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03920       /* If we were already heading for a depot but it has
03921        * suddenly moved farther away, we continue our normal
03922        * schedule? */
03923       v->current_order.MakeDummy();
03924       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03925     }
03926     return;
03927   }
03928 
03929   DepotID depot = GetDepotIndex(tfdd.tile);
03930 
03931   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03932       v->current_order.GetDestination() != depot &&
03933       !Chance16(3, 16)) {
03934     return;
03935   }
03936 
03937   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03938   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03939   v->dest_tile = tfdd.tile;
03940   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03941 }
03942 
03944 void Train::OnNewDay()
03945 {
03946   AgeVehicle(this);
03947 
03948   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03949 
03950   if (this->IsFrontEngine()) {
03951     CheckVehicleBreakdown(this);
03952 
03953     CheckIfTrainNeedsService(this);
03954 
03955     CheckOrders(this);
03956 
03957     /* update destination */
03958     if (this->current_order.IsType(OT_GOTO_STATION)) {
03959       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03960       if (tile != INVALID_TILE) this->dest_tile = tile;
03961     }
03962 
03963     if (this->running_ticks != 0) {
03964       /* running costs */
03965       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03966 
03967       this->profit_this_year -= cost.GetCost();
03968       this->running_ticks = 0;
03969 
03970       SubtractMoneyFromCompanyFract(this->owner, cost);
03971 
03972       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03973       SetWindowClassesDirty(WC_TRAINS_LIST);
03974     }
03975   }
03976 }
03977 
03982 Trackdir Train::GetVehicleTrackdir() const
03983 {
03984   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03985 
03986   if (this->track == TRACK_BIT_DEPOT) {
03987     /* We'll assume the train is facing outwards */
03988     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03989   }
03990 
03991   if (this->track == TRACK_BIT_WORMHOLE) {
03992     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03993     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03994   }
03995 
03996   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03997 }