train_cmd.cpp

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00001 /* $Id: train_cmd.cpp 24082 2012-03-31 17:55:38Z rubidium $ */
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 
00689     v->engine_type = e->index;
00690     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00691 
00692     v->reliability = e->reliability;
00693     v->reliability_spd_dec = e->reliability_spd_dec;
00694     v->max_age = e->GetLifeLengthInDays();
00695 
00696     v->railtype = rvi->railtype;
00697     _new_vehicle_id = v->index;
00698 
00699     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00700     v->date_of_last_service = _date;
00701     v->build_year = _cur_year;
00702     v->cur_image = SPR_IMG_QUERY;
00703     v->random_bits = VehicleRandomBits();
00704 
00705     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00706 
00707     v->group_id = DEFAULT_GROUP;
00708 
00709     v->SetFrontEngine();
00710     v->SetEngine();
00711 
00712     VehicleUpdatePosition(v);
00713 
00714     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00715       AddRearEngineToMultiheadedTrain(v);
00716     } else {
00717       AddArticulatedParts(v);
00718     }
00719 
00720     v->ConsistChanged(false);
00721     UpdateTrainGroupID(v);
00722 
00723     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00724       NormalizeTrainVehInDepot(v);
00725     }
00726 
00727     CheckConsistencyOfArticulatedVehicle(v);
00728   }
00729 
00730   return CommandCost();
00731 }
00732 
00737 bool Train::IsInDepot() const
00738 {
00739   /* Is the front engine stationary in the depot? */
00740   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00741 
00742   /* Check whether the rest is also already trying to enter the depot. */
00743   for (const Train *v = this; v != NULL; v = v->Next()) {
00744     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00745   }
00746 
00747   return true;
00748 }
00749 
00754 bool Train::IsStoppedInDepot() const
00755 {
00756   /* Are we stopped? Of course wagons don't really care... */
00757   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00758   return this->IsInDepot();
00759 }
00760 
00761 static Train *FindGoodVehiclePos(const Train *src)
00762 {
00763   EngineID eng = src->engine_type;
00764   TileIndex tile = src->tile;
00765 
00766   Train *dst;
00767   FOR_ALL_TRAINS(dst) {
00768     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00769       /* check so all vehicles in the line have the same engine. */
00770       Train *t = dst;
00771       while (t->engine_type == eng) {
00772         t = t->Next();
00773         if (t == NULL) return dst;
00774       }
00775     }
00776   }
00777 
00778   return NULL;
00779 }
00780 
00782 typedef SmallVector<Train *, 16> TrainList;
00783 
00789 static void MakeTrainBackup(TrainList &list, Train *t)
00790 {
00791   for (; t != NULL; t = t->Next()) *list.Append() = t;
00792 }
00793 
00798 static void RestoreTrainBackup(TrainList &list)
00799 {
00800   /* No train, nothing to do. */
00801   if (list.Length() == 0) return;
00802 
00803   Train *prev = NULL;
00804   /* Iterate over the list and rebuild it. */
00805   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00806     Train *t = *iter;
00807     if (prev != NULL) {
00808       prev->SetNext(t);
00809     } else if (t->Previous() != NULL) {
00810       /* Make sure the head of the train is always the first in the chain. */
00811       t->Previous()->SetNext(NULL);
00812     }
00813     prev = t;
00814   }
00815 }
00816 
00822 static void RemoveFromConsist(Train *part, bool chain = false)
00823 {
00824   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00825 
00826   /* Unlink at the front, but make it point to the next
00827    * vehicle after the to be remove part. */
00828   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00829 
00830   /* Unlink at the back */
00831   tail->SetNext(NULL);
00832 }
00833 
00839 static void InsertInConsist(Train *dst, Train *chain)
00840 {
00841   /* We do not want to add something in the middle of an articulated part. */
00842   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00843 
00844   chain->Last()->SetNext(dst->Next());
00845   dst->SetNext(chain);
00846 }
00847 
00853 static void NormaliseDualHeads(Train *t)
00854 {
00855   for (; t != NULL; t = t->GetNextVehicle()) {
00856     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00857 
00858     /* Make sure that there are no free cars before next engine */
00859     Train *u;
00860     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00861 
00862     if (u == t->other_multiheaded_part) continue;
00863 
00864     /* Remove the part from the 'wrong' train */
00865     RemoveFromConsist(t->other_multiheaded_part);
00866     /* And add it to the 'right' train */
00867     InsertInConsist(u, t->other_multiheaded_part);
00868   }
00869 }
00870 
00875 static void NormaliseSubtypes(Train *chain)
00876 {
00877   /* Nothing to do */
00878   if (chain == NULL) return;
00879 
00880   /* We must be the first in the chain. */
00881   assert(chain->Previous() == NULL);
00882 
00883   /* Set the appropriate bits for the first in the chain. */
00884   if (chain->IsWagon()) {
00885     chain->SetFreeWagon();
00886   } else {
00887     assert(chain->IsEngine());
00888     chain->SetFrontEngine();
00889   }
00890 
00891   /* Now clear the bits for the rest of the chain */
00892   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00893     t->ClearFreeWagon();
00894     t->ClearFrontEngine();
00895   }
00896 }
00897 
00907 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00908 {
00909   /* Just add 'new' engines and subtract the original ones.
00910    * If that's less than or equal to 0 we can be sure we did
00911    * not add any engines (read: trains) along the way. */
00912   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00913       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00914       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00915       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00916     return CommandCost();
00917   }
00918 
00919   /* Get a free unit number and check whether it's within the bounds.
00920    * There will always be a maximum of one new train. */
00921   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00922 
00923   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00924 }
00925 
00931 static CommandCost CheckTrainAttachment(Train *t)
00932 {
00933   /* No multi-part train, no need to check. */
00934   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00935 
00936   /* The maximum length for a train. For each part we decrease this by one
00937    * and if the result is negative the train is simply too long. */
00938   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00939 
00940   Train *head = t;
00941   Train *prev = t;
00942 
00943   /* Break the prev -> t link so it always holds within the loop. */
00944   t = t->Next();
00945   prev->SetNext(NULL);
00946 
00947   /* Make sure the cache is cleared. */
00948   head->InvalidateNewGRFCache();
00949 
00950   while (t != NULL) {
00951     allowed_len -= t->gcache.cached_veh_length;
00952 
00953     Train *next = t->Next();
00954 
00955     /* Unlink the to-be-added piece; it is already unlinked from the previous
00956      * part due to the fact that the prev -> t link is broken. */
00957     t->SetNext(NULL);
00958 
00959     /* Don't check callback for articulated or rear dual headed parts */
00960     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00961       /* Back up and clear the first_engine data to avoid using wagon override group */
00962       EngineID first_engine = t->gcache.first_engine;
00963       t->gcache.first_engine = INVALID_ENGINE;
00964 
00965       /* We don't want the cache to interfere. head's cache is cleared before
00966        * the loop and after each callback does not need to be cleared here. */
00967       t->InvalidateNewGRFCache();
00968 
00969       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00970 
00971       /* Restore original first_engine data */
00972       t->gcache.first_engine = first_engine;
00973 
00974       /* We do not want to remember any cached variables from the test run */
00975       t->InvalidateNewGRFCache();
00976       head->InvalidateNewGRFCache();
00977 
00978       if (callback != CALLBACK_FAILED) {
00979         /* A failing callback means everything is okay */
00980         StringID error = STR_NULL;
00981 
00982         if (head->GetGRF()->grf_version < 8) {
00983           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00984           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00985           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00986         } else {
00987           if (callback < 0x400) {
00988             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00989           } else {
00990             switch (callback) {
00991               case 0x400: // allow if railtypes match (always the case for OpenTTD)
00992               case 0x401: // allow
00993                 break;
00994 
00995               default:    // unknown reason -> disallow
00996               case 0x402: // disallow attaching
00997                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00998                 break;
00999             }
01000           }
01001         }
01002 
01003         if (error != STR_NULL) return_cmd_error(error);
01004       }
01005     }
01006 
01007     /* And link it to the new part. */
01008     prev->SetNext(t);
01009     prev = t;
01010     t = next;
01011   }
01012 
01013   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01014   return CommandCost();
01015 }
01016 
01027 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01028 {
01029   /* Check whether we may actually construct the trains. */
01030   CommandCost ret = CheckTrainAttachment(src);
01031   if (ret.Failed()) return ret;
01032   ret = CheckTrainAttachment(dst);
01033   if (ret.Failed()) return ret;
01034 
01035   /* Check whether we need to build a new train. */
01036   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01037 }
01038 
01047 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01048 {
01049   /* First determine the front of the two resulting trains */
01050   if (*src_head == *dst_head) {
01051     /* If we aren't moving part(s) to a new train, we are just moving the
01052      * front back and there is not destination head. */
01053     *dst_head = NULL;
01054   } else if (*dst_head == NULL) {
01055     /* If we are moving to a new train the head of the move train would become
01056      * the head of the new vehicle. */
01057     *dst_head = src;
01058   }
01059 
01060   if (src == *src_head) {
01061     /* If we are moving the front of a train then we are, in effect, creating
01062      * a new head for the train. Point to that. Unless we are moving the whole
01063      * train in which case there is not 'source' train anymore.
01064      * In case we are a multiheaded part we want the complete thing to come
01065      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01066      * that is followed by a rear multihead we do not want to include that. */
01067     *src_head = move_chain ? NULL :
01068         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01069   }
01070 
01071   /* Now it's just simply removing the part that we are going to move from the
01072    * source train and *if* the destination is a not a new train add the chain
01073    * at the destination location. */
01074   RemoveFromConsist(src, move_chain);
01075   if (*dst_head != src) InsertInConsist(dst, src);
01076 
01077   /* Now normalise the dual heads, that is move the dual heads around in such
01078    * a way that the head and rear of a dual head are in the same train */
01079   NormaliseDualHeads(*src_head);
01080   NormaliseDualHeads(*dst_head);
01081 }
01082 
01088 static void NormaliseTrainHead(Train *head)
01089 {
01090   /* Not much to do! */
01091   if (head == NULL) return;
01092 
01093   /* Tell the 'world' the train changed. */
01094   head->ConsistChanged(false);
01095   UpdateTrainGroupID(head);
01096 
01097   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01098   if (!head->IsFrontEngine()) return;
01099 
01100   /* Update the refit button and window */
01101   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01102   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01103 
01104   /* If we don't have a unit number yet, set one. */
01105   if (head->unitnumber != 0) return;
01106   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01107 }
01108 
01121 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01122 {
01123   VehicleID s = GB(p1, 0, 20);
01124   VehicleID d = GB(p2, 0, 20);
01125   bool move_chain = HasBit(p1, 20);
01126 
01127   Train *src = Train::GetIfValid(s);
01128   if (src == NULL) return CMD_ERROR;
01129 
01130   CommandCost ret = CheckOwnership(src->owner);
01131   if (ret.Failed()) return ret;
01132 
01133   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01134   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01135 
01136   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01137   Train *dst;
01138   if (d == INVALID_VEHICLE) {
01139     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01140   } else {
01141     dst = Train::GetIfValid(d);
01142     if (dst == NULL) return CMD_ERROR;
01143 
01144     CommandCost ret = CheckOwnership(dst->owner);
01145     if (ret.Failed()) return ret;
01146 
01147     /* Do not allow appending to crashed vehicles, too */
01148     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01149   }
01150 
01151   /* if an articulated part is being handled, deal with its parent vehicle */
01152   src = src->GetFirstEnginePart();
01153   if (dst != NULL) {
01154     dst = dst->GetFirstEnginePart();
01155   }
01156 
01157   /* don't move the same vehicle.. */
01158   if (src == dst) return CommandCost();
01159 
01160   /* locate the head of the two chains */
01161   Train *src_head = src->First();
01162   Train *dst_head;
01163   if (dst != NULL) {
01164     dst_head = dst->First();
01165     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01166     /* Now deal with articulated part of destination wagon */
01167     dst = dst->GetLastEnginePart();
01168   } else {
01169     dst_head = NULL;
01170   }
01171 
01172   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01173 
01174   /* When moving all wagons, we can't have the same src_head and dst_head */
01175   if (move_chain && src_head == dst_head) return CommandCost();
01176 
01177   /* When moving a multiheaded part to be place after itself, bail out. */
01178   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01179 
01180   /* Check if all vehicles in the source train are stopped inside a depot. */
01181   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01182 
01183   /* Check if all vehicles in the destination train are stopped inside a depot. */
01184   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01185 
01186   /* First make a backup of the order of the trains. That way we can do
01187    * whatever we want with the order and later on easily revert. */
01188   TrainList original_src;
01189   TrainList original_dst;
01190 
01191   MakeTrainBackup(original_src, src_head);
01192   MakeTrainBackup(original_dst, dst_head);
01193 
01194   /* Also make backup of the original heads as ArrangeTrains can change them.
01195    * For the destination head we do not care if it is the same as the source
01196    * head because in that case it's just a copy. */
01197   Train *original_src_head = src_head;
01198   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01199 
01200   /* We want this information from before the rearrangement, but execute this after the validation. */
01201   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01202   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01203 
01204   /* (Re)arrange the trains in the wanted arrangement. */
01205   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01206 
01207   if ((flags & DC_AUTOREPLACE) == 0) {
01208     /* If the autoreplace flag is set we do not need to test for the validity
01209      * because we are going to revert the train to its original state. As we
01210      * assume the original state was correct autoreplace can skip this. */
01211     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01212     if (ret.Failed()) {
01213       /* Restore the train we had. */
01214       RestoreTrainBackup(original_src);
01215       RestoreTrainBackup(original_dst);
01216       return ret;
01217     }
01218   }
01219 
01220   /* do it? */
01221   if (flags & DC_EXEC) {
01222     /* Remove old heads from the statistics */
01223     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01224     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01225 
01226     /* First normalise the sub types of the chains. */
01227     NormaliseSubtypes(src_head);
01228     NormaliseSubtypes(dst_head);
01229 
01230     /* There are 14 different cases:
01231      *  1) front engine gets moved to a new train, it stays a front engine.
01232      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01233      *     b) the 'next' part is an engine that becomes a front engine.
01234      *     c) there is no 'next' part, nothing else happens
01235      *  2) front engine gets moved to another train, it is not a front engine anymore
01236      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01237      *     b) the 'next' part is an engine that becomes a front engine.
01238      *     c) there is no 'next' part, nothing else happens
01239      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01240      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01241      *     b) the 'next' part is an engine that becomes a front engine.
01242      *  4) free wagon gets moved
01243      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01244      *     b) the 'next' part is an engine that becomes a front engine.
01245      *     c) there is no 'next' part, nothing else happens
01246      *  5) non front engine gets moved and becomes a new train, nothing else happens
01247      *  6) non front engine gets moved within a train / to another train, nothing hapens
01248      *  7) wagon gets moved, nothing happens
01249      */
01250     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01251       /* Cases #2 and #3: the front engine gets trashed. */
01252       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01253       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01254       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01255       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01256       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01257       SetWindowDirty(WC_COMPANY, _current_company);
01258 
01259       /* Delete orders, group stuff and the unit number as we're not the
01260        * front of any vehicle anymore. */
01261       DeleteVehicleOrders(src);
01262       RemoveVehicleFromGroup(src);
01263       src->unitnumber = 0;
01264     }
01265 
01266     /* We weren't a front engine but are becoming one. So
01267      * we should be put in the default group. */
01268     if (original_src_head != src && dst_head == src) {
01269       SetTrainGroupID(src, DEFAULT_GROUP);
01270       SetWindowDirty(WC_COMPANY, _current_company);
01271     }
01272 
01273     /* Add new heads to statistics */
01274     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01275     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01276 
01277     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01278     NormaliseTrainHead(src_head);
01279     NormaliseTrainHead(dst_head);
01280 
01281     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01282       CheckCargoCapacity(src_head);
01283       CheckCargoCapacity(dst_head);
01284     }
01285 
01286     /* We are undoubtedly changing something in the depot and train list. */
01287     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01288     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01289   } else {
01290     /* We don't want to execute what we're just tried. */
01291     RestoreTrainBackup(original_src);
01292     RestoreTrainBackup(original_dst);
01293   }
01294 
01295   return CommandCost();
01296 }
01297 
01309 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01310 {
01311   /* Check if we deleted a vehicle window */
01312   Window *w = NULL;
01313 
01314   /* Sell a chain of vehicles or not? */
01315   bool sell_chain = HasBit(data, 0);
01316 
01317   Train *v = Train::From(t)->GetFirstEnginePart();
01318   Train *first = v->First();
01319 
01320   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01321 
01322   /* First make a backup of the order of the train. That way we can do
01323    * whatever we want with the order and later on easily revert. */
01324   TrainList original;
01325   MakeTrainBackup(original, first);
01326 
01327   /* We need to keep track of the new head and the head of what we're going to sell. */
01328   Train *new_head = first;
01329   Train *sell_head = NULL;
01330 
01331   /* Split the train in the wanted way. */
01332   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01333 
01334   /* We don't need to validate the second train; it's going to be sold. */
01335   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01336   if (ret.Failed()) {
01337     /* Restore the train we had. */
01338     RestoreTrainBackup(original);
01339     return ret;
01340   }
01341 
01342   CommandCost cost(EXPENSES_NEW_VEHICLES);
01343   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01344 
01345   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01346     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01347   }
01348 
01349   /* do it? */
01350   if (flags & DC_EXEC) {
01351     /* First normalise the sub types of the chain. */
01352     NormaliseSubtypes(new_head);
01353 
01354     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01355       /* We are selling the front engine. In this case we want to
01356        * 'give' the order, unit number and such to the new head. */
01357       new_head->orders.list = first->orders.list;
01358       new_head->AddToShared(first);
01359       DeleteVehicleOrders(first);
01360 
01361       /* Copy other important data from the front engine */
01362       new_head->CopyVehicleConfigAndStatistics(first);
01363       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01364 
01365       /* If we deleted a window then open a new one for the 'new' train */
01366       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01367     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01368       OrderBackup::Backup(v, user);
01369     }
01370 
01371     /* We need to update the information about the train. */
01372     NormaliseTrainHead(new_head);
01373 
01374     /* We are undoubtedly changing something in the depot and train list. */
01375     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01376     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01377 
01378     /* Actually delete the sold 'goods' */
01379     delete sell_head;
01380   } else {
01381     /* We don't want to execute what we're just tried. */
01382     RestoreTrainBackup(original);
01383   }
01384 
01385   return cost;
01386 }
01387 
01388 void Train::UpdateDeltaXY(Direction direction)
01389 {
01390   /* Set common defaults. */
01391   this->x_offs    = -1;
01392   this->y_offs    = -1;
01393   this->x_extent  =  3;
01394   this->y_extent  =  3;
01395   this->z_extent  =  6;
01396   this->x_bb_offs =  0;
01397   this->y_bb_offs =  0;
01398 
01399   if (!IsDiagonalDirection(direction)) {
01400     static const int _sign_table[] =
01401     {
01402       // x, y
01403       -1, -1, // DIR_N
01404       -1,  1, // DIR_E
01405        1,  1, // DIR_S
01406        1, -1, // DIR_W
01407     };
01408 
01409     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01410 
01411     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01412     this->x_offs -= half_shorten * _sign_table[direction];
01413     this->y_offs -= half_shorten * _sign_table[direction + 1];
01414     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01415     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01416   } else {
01417     switch (direction) {
01418         /* Shorten southern corner of the bounding box according the vehicle length
01419          * and center the bounding box on the vehicle. */
01420       case DIR_NE:
01421         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01422         this->x_extent  = this->gcache.cached_veh_length - 1;
01423         this->x_bb_offs = -1;
01424         break;
01425 
01426       case DIR_NW:
01427         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01428         this->y_extent  = this->gcache.cached_veh_length - 1;
01429         this->y_bb_offs = -1;
01430         break;
01431 
01432         /* Move northern corner of the bounding box down according to vehicle length
01433          * and center the bounding box on the vehicle. */
01434       case DIR_SW:
01435         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01436         this->x_extent  = VEHICLE_LENGTH - 1;
01437         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01438         break;
01439 
01440       case DIR_SE:
01441         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01442         this->y_extent  = VEHICLE_LENGTH - 1;
01443         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01444         break;
01445 
01446       default:
01447         NOT_REACHED();
01448     }
01449   }
01450 }
01451 
01456 static void MarkTrainAsStuck(Train *v)
01457 {
01458   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01459     /* It is the first time the problem occurred, set the "train stuck" flag. */
01460     SetBit(v->flags, VRF_TRAIN_STUCK);
01461 
01462     v->wait_counter = 0;
01463 
01464     /* Stop train */
01465     v->cur_speed = 0;
01466     v->subspeed = 0;
01467     v->SetLastSpeed();
01468 
01469     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01470   }
01471 }
01472 
01480 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01481 {
01482   uint16 flag1 = *swap_flag1;
01483   uint16 flag2 = *swap_flag2;
01484 
01485   /* Clear the flags */
01486   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01487   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01488   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01489   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01490 
01491   /* Reverse the rail-flags (if needed) */
01492   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01493     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01494   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01495     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01496   }
01497   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01498     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01499   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01500     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01501   }
01502 }
01503 
01508 static void UpdateStatusAfterSwap(Train *v)
01509 {
01510   /* Reverse the direction. */
01511   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01512 
01513   /* Call the proper EnterTile function unless we are in a wormhole. */
01514   if (v->track != TRACK_BIT_WORMHOLE) {
01515     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01516   } else {
01517     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01518      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01519      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01520      * when we shouldn't have. Check if this is the case. */
01521     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01522     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01523       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01524       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01525         /* We have just left the wormhole, possibly set the
01526          * "goingdown" bit. UpdateInclination() can be used
01527          * because we are at the border of the tile. */
01528         VehicleUpdatePosition(v);
01529         v->UpdateInclination(true, true);
01530         return;
01531       }
01532     }
01533   }
01534 
01535   VehicleUpdatePosition(v);
01536   v->UpdateViewport(true, true);
01537 }
01538 
01545 void ReverseTrainSwapVeh(Train *v, int l, int r)
01546 {
01547   Train *a, *b;
01548 
01549   /* locate vehicles to swap */
01550   for (a = v; l != 0; l--) a = a->Next();
01551   for (b = v; r != 0; r--) b = b->Next();
01552 
01553   if (a != b) {
01554     /* swap the hidden bits */
01555     {
01556       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01557       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01558       a->vehstatus = tmp;
01559     }
01560 
01561     Swap(a->track, b->track);
01562     Swap(a->direction, b->direction);
01563     Swap(a->x_pos, b->x_pos);
01564     Swap(a->y_pos, b->y_pos);
01565     Swap(a->tile,  b->tile);
01566     Swap(a->z_pos, b->z_pos);
01567 
01568     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01569 
01570     UpdateStatusAfterSwap(a);
01571     UpdateStatusAfterSwap(b);
01572   } else {
01573     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01574      * This is a little bit redundant way, a->gv_flags will
01575      * be (re)set twice, but it reduces code duplication */
01576     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01577     UpdateStatusAfterSwap(a);
01578   }
01579 }
01580 
01581 
01587 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01588 {
01589   return (v->type == VEH_TRAIN) ? v : NULL;
01590 }
01591 
01592 
01599 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01600 {
01601   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01602 
01603   Train *t = Train::From(v);
01604   if (!t->IsFrontEngine()) return NULL;
01605 
01606   TileIndex tile = *(TileIndex *)data;
01607 
01608   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01609 
01610   return t;
01611 }
01612 
01613 
01620 static bool TrainApproachingCrossing(TileIndex tile)
01621 {
01622   assert(IsLevelCrossingTile(tile));
01623 
01624   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01625   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01626 
01627   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01628 
01629   dir = ReverseDiagDir(dir);
01630   tile_from = tile + TileOffsByDiagDir(dir);
01631 
01632   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01633 }
01634 
01635 
01642 void UpdateLevelCrossing(TileIndex tile, bool sound)
01643 {
01644   assert(IsLevelCrossingTile(tile));
01645 
01646   /* train on crossing || train approaching crossing || reserved */
01647   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01648 
01649   if (new_state != IsCrossingBarred(tile)) {
01650     if (new_state && sound) {
01651       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01652     }
01653     SetCrossingBarred(tile, new_state);
01654     MarkTileDirtyByTile(tile);
01655   }
01656 }
01657 
01658 
01664 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01665 {
01666   if (!IsCrossingBarred(tile)) {
01667     BarCrossing(tile);
01668     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01669     MarkTileDirtyByTile(tile);
01670   }
01671 }
01672 
01673 
01679 static void AdvanceWagonsBeforeSwap(Train *v)
01680 {
01681   Train *base = v;
01682   Train *first = base; // first vehicle to move
01683   Train *last = v->Last(); // last vehicle to move
01684   uint length = CountVehiclesInChain(v);
01685 
01686   while (length > 2) {
01687     last = last->Previous();
01688     first = first->Next();
01689 
01690     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01691 
01692     /* do not update images now
01693      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01694     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01695 
01696     base = first; // == base->Next()
01697     length -= 2;
01698   }
01699 }
01700 
01701 
01707 static void AdvanceWagonsAfterSwap(Train *v)
01708 {
01709   /* first of all, fix the situation when the train was entering a depot */
01710   Train *dep = v; // last vehicle in front of just left depot
01711   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01712     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01713   }
01714 
01715   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01716 
01717   if (leave != NULL) {
01718     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01719     int d = TicksToLeaveDepot(dep);
01720 
01721     if (d <= 0) {
01722       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01723       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01724       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01725     }
01726   } else {
01727     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01728   }
01729 
01730   Train *base = v;
01731   Train *first = base; // first vehicle to move
01732   Train *last = v->Last(); // last vehicle to move
01733   uint length = CountVehiclesInChain(v);
01734 
01735   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01736    * they have already correct spacing, so we have to make sure they are moved how they should */
01737   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01738 
01739   while (length > 2) {
01740     /* we reached vehicle (originally) in front of a depot, stop now
01741      * (we would move wagons that are already moved with new wagon length). */
01742     if (base == dep) break;
01743 
01744     /* the last wagon was that one leaving a depot, so do not move it anymore */
01745     if (last == dep) nomove = true;
01746 
01747     last = last->Previous();
01748     first = first->Next();
01749 
01750     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01751 
01752     /* do not update images now */
01753     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01754 
01755     base = first; // == base->Next()
01756     length -= 2;
01757   }
01758 }
01759 
01764 void ReverseTrainDirection(Train *v)
01765 {
01766   if (IsRailDepotTile(v->tile)) {
01767     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01768   }
01769 
01770   /* Clear path reservation in front if train is not stuck. */
01771   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01772 
01773   /* Check if we were approaching a rail/road-crossing */
01774   TileIndex crossing = TrainApproachingCrossingTile(v);
01775 
01776   /* count number of vehicles */
01777   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01778 
01779   AdvanceWagonsBeforeSwap(v);
01780 
01781   /* swap start<>end, start+1<>end-1, ... */
01782   int l = 0;
01783   do {
01784     ReverseTrainSwapVeh(v, l++, r--);
01785   } while (l <= r);
01786 
01787   AdvanceWagonsAfterSwap(v);
01788 
01789   if (IsRailDepotTile(v->tile)) {
01790     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01791   }
01792 
01793   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01794 
01795   ClrBit(v->flags, VRF_REVERSING);
01796 
01797   /* recalculate cached data */
01798   v->ConsistChanged(true);
01799 
01800   /* update all images */
01801   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01802 
01803   /* update crossing we were approaching */
01804   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01805 
01806   /* maybe we are approaching crossing now, after reversal */
01807   crossing = TrainApproachingCrossingTile(v);
01808   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01809 
01810   /* If we are inside a depot after reversing, don't bother with path reserving. */
01811   if (v->track == TRACK_BIT_DEPOT) {
01812     /* Can't be stuck here as inside a depot is always a safe tile. */
01813     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01814     ClrBit(v->flags, VRF_TRAIN_STUCK);
01815     return;
01816   }
01817 
01818   /* TrainExitDir does not always produce the desired dir for depots and
01819    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01820   DiagDirection dir = TrainExitDir(v->direction, v->track);
01821   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01822 
01823   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01824     /* If we are currently on a tile with conventional signals, we can't treat the
01825      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01826     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01827       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01828       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01829 
01830     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01831     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01832 
01833     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01834     if (TryPathReserve(v, false, first_tile_okay)) {
01835       /* Do a look-ahead now in case our current tile was already a safe tile. */
01836       CheckNextTrainTile(v);
01837     } else if (v->current_order.GetType() != OT_LOADING) {
01838       /* Do not wait for a way out when we're still loading */
01839       MarkTrainAsStuck(v);
01840     }
01841   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01842     /* A train not inside a PBS block can't be stuck. */
01843     ClrBit(v->flags, VRF_TRAIN_STUCK);
01844     v->wait_counter = 0;
01845   }
01846 }
01847 
01857 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01858 {
01859   Train *v = Train::GetIfValid(p1);
01860   if (v == NULL) return CMD_ERROR;
01861 
01862   CommandCost ret = CheckOwnership(v->owner);
01863   if (ret.Failed()) return ret;
01864 
01865   if (p2 != 0) {
01866     /* turn a single unit around */
01867 
01868     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01869       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01870     }
01871     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01872 
01873     Train *front = v->First();
01874     /* make sure the vehicle is stopped in the depot */
01875     if (!front->IsStoppedInDepot()) {
01876       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01877     }
01878 
01879     if (flags & DC_EXEC) {
01880       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01881 
01882       front->ConsistChanged(false);
01883       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01884       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01885       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01886       SetWindowClassesDirty(WC_TRAINS_LIST);
01887     }
01888   } else {
01889     /* turn the whole train around */
01890     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01891 
01892     if (flags & DC_EXEC) {
01893       /* Properly leave the station if we are loading and won't be loading anymore */
01894       if (v->current_order.IsType(OT_LOADING)) {
01895         const Vehicle *last = v;
01896         while (last->Next() != NULL) last = last->Next();
01897 
01898         /* not a station || different station --> leave the station */
01899         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01900           v->LeaveStation();
01901         }
01902       }
01903 
01904       /* We cancel any 'skip signal at dangers' here */
01905       v->force_proceed = TFP_NONE;
01906       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01907 
01908       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01909         ToggleBit(v->flags, VRF_REVERSING);
01910       } else {
01911         v->cur_speed = 0;
01912         v->SetLastSpeed();
01913         HideFillingPercent(&v->fill_percent_te_id);
01914         ReverseTrainDirection(v);
01915       }
01916     }
01917   }
01918   return CommandCost();
01919 }
01920 
01930 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01931 {
01932   Train *t = Train::GetIfValid(p1);
01933   if (t == NULL) return CMD_ERROR;
01934 
01935   CommandCost ret = CheckOwnership(t->owner);
01936   if (ret.Failed()) return ret;
01937 
01938 
01939   if (flags & DC_EXEC) {
01940     /* If we are forced to proceed, cancel that order.
01941      * If we are marked stuck we would want to force the train
01942      * to proceed to the next signal. In the other cases we
01943      * would like to pass the signal at danger and run till the
01944      * next signal we encounter. */
01945     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01946     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01947   }
01948 
01949   return CommandCost();
01950 }
01951 
01959 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01960 {
01961   assert(!(v->vehstatus & VS_CRASHED));
01962 
01963   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01964 
01965   PBSTileInfo origin = FollowTrainReservation(v);
01966   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01967 
01968   switch (_settings_game.pf.pathfinder_for_trains) {
01969     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01970     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01971 
01972     default: NOT_REACHED();
01973   }
01974 }
01975 
01983 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01984 {
01985   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01986   if (tfdd.best_length == UINT_MAX) return false;
01987 
01988   if (location    != NULL) *location    = tfdd.tile;
01989   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01990   if (reverse     != NULL) *reverse     = tfdd.reverse;
01991 
01992   return true;
01993 }
01994 
01996 void Train::PlayLeaveStationSound() const
01997 {
01998   static const SoundFx sfx[] = {
01999     SND_04_TRAIN,
02000     SND_0A_TRAIN_HORN,
02001     SND_0A_TRAIN_HORN,
02002     SND_47_MAGLEV_2,
02003     SND_41_MAGLEV
02004   };
02005 
02006   if (PlayVehicleSound(this, VSE_START)) return;
02007 
02008   EngineID engtype = this->engine_type;
02009   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02010 }
02011 
02016 static void CheckNextTrainTile(Train *v)
02017 {
02018   /* Don't do any look-ahead if path_backoff_interval is 255. */
02019   if (_settings_game.pf.path_backoff_interval == 255) return;
02020 
02021   /* Exit if we are inside a depot. */
02022   if (v->track == TRACK_BIT_DEPOT) return;
02023 
02024   switch (v->current_order.GetType()) {
02025     /* Exit if we reached our destination depot. */
02026     case OT_GOTO_DEPOT:
02027       if (v->tile == v->dest_tile) return;
02028       break;
02029 
02030     case OT_GOTO_WAYPOINT:
02031       /* If we reached our waypoint, make sure we see that. */
02032       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02033       break;
02034 
02035     case OT_NOTHING:
02036     case OT_LEAVESTATION:
02037     case OT_LOADING:
02038       /* Exit if the current order doesn't have a destination, but the train has orders. */
02039       if (v->GetNumOrders() > 0) return;
02040       break;
02041 
02042     default:
02043       break;
02044   }
02045   /* Exit if we are on a station tile and are going to stop. */
02046   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02047 
02048   Trackdir td = v->GetVehicleTrackdir();
02049 
02050   /* On a tile with a red non-pbs signal, don't look ahead. */
02051   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02052       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02053       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02054 
02055   CFollowTrackRail ft(v);
02056   if (!ft.Follow(v->tile, td)) return;
02057 
02058   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02059     /* Next tile is not reserved. */
02060     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02061       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02062         /* If the next tile is a PBS signal, try to make a reservation. */
02063         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02064         if (_settings_game.pf.forbid_90_deg) {
02065           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02066         }
02067         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02068       }
02069     }
02070   }
02071 }
02072 
02078 static bool CheckTrainStayInDepot(Train *v)
02079 {
02080   /* bail out if not all wagons are in the same depot or not in a depot at all */
02081   for (const Train *u = v; u != NULL; u = u->Next()) {
02082     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02083   }
02084 
02085   /* if the train got no power, then keep it in the depot */
02086   if (v->gcache.cached_power == 0) {
02087     v->vehstatus |= VS_STOPPED;
02088     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02089     return true;
02090   }
02091 
02092   SigSegState seg_state;
02093 
02094   if (v->force_proceed == TFP_NONE) {
02095     /* force proceed was not pressed */
02096     if (++v->wait_counter < 37) {
02097       SetWindowClassesDirty(WC_TRAINS_LIST);
02098       return true;
02099     }
02100 
02101     v->wait_counter = 0;
02102 
02103     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02104     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02105       /* Full and no PBS signal in block or depot reserved, can't exit. */
02106       SetWindowClassesDirty(WC_TRAINS_LIST);
02107       return true;
02108     }
02109   } else {
02110     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02111   }
02112 
02113   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02114   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02115     /* We need to have a reservation for this to work. */
02116     if (HasDepotReservation(v->tile)) return true;
02117     SetDepotReservation(v->tile, true);
02118     VehicleEnterDepot(v);
02119     return true;
02120   }
02121 
02122   /* Only leave when we can reserve a path to our destination. */
02123   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02124     /* No path and no force proceed. */
02125     SetWindowClassesDirty(WC_TRAINS_LIST);
02126     MarkTrainAsStuck(v);
02127     return true;
02128   }
02129 
02130   SetDepotReservation(v->tile, true);
02131   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02132 
02133   VehicleServiceInDepot(v);
02134   SetWindowClassesDirty(WC_TRAINS_LIST);
02135   v->PlayLeaveStationSound();
02136 
02137   v->track = TRACK_BIT_X;
02138   if (v->direction & 2) v->track = TRACK_BIT_Y;
02139 
02140   v->vehstatus &= ~VS_HIDDEN;
02141   v->cur_speed = 0;
02142 
02143   v->UpdateViewport(true, true);
02144   VehicleUpdatePosition(v);
02145   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02146   v->UpdateAcceleration();
02147   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02148 
02149   return false;
02150 }
02151 
02158 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02159 {
02160   DiagDirection dir = TrackdirToExitdir(track_dir);
02161 
02162   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02163     /* Are we just leaving a tunnel/bridge? */
02164     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02165       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02166 
02167       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02168         /* Free the reservation only if no other train is on the tiles. */
02169         SetTunnelBridgeReservation(tile, false);
02170         SetTunnelBridgeReservation(end, false);
02171 
02172         if (_settings_client.gui.show_track_reservation) {
02173           MarkTileDirtyByTile(tile);
02174           MarkTileDirtyByTile(end);
02175         }
02176       }
02177     }
02178   } else if (IsRailStationTile(tile)) {
02179     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02180     /* If the new tile is not a further tile of the same station, we
02181      * clear the reservation for the whole platform. */
02182     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02183       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02184     }
02185   } else {
02186     /* Any other tile */
02187     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02188   }
02189 }
02190 
02197 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02198 {
02199   assert(v->IsFrontEngine());
02200 
02201   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02202   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02203   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02204   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02205 
02206   /* Can't be holding a reservation if we enter a depot. */
02207   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02208   if (v->track == TRACK_BIT_DEPOT) {
02209     /* Front engine is in a depot. We enter if some part is not in the depot. */
02210     for (const Train *u = v; u != NULL; u = u->Next()) {
02211       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02212     }
02213   }
02214   /* Don't free reservation if it's not ours. */
02215   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02216 
02217   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02218   while (ft.Follow(tile, td)) {
02219     tile = ft.m_new_tile;
02220     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02221     td = RemoveFirstTrackdir(&bits);
02222     assert(bits == TRACKDIR_BIT_NONE);
02223 
02224     if (!IsValidTrackdir(td)) break;
02225 
02226     if (IsTileType(tile, MP_RAILWAY)) {
02227       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02228         /* Conventional signal along trackdir: remove reservation and stop. */
02229         UnreserveRailTrack(tile, TrackdirToTrack(td));
02230         break;
02231       }
02232       if (HasPbsSignalOnTrackdir(tile, td)) {
02233         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02234           /* Red PBS signal? Can't be our reservation, would be green then. */
02235           break;
02236         } else {
02237           /* Turn the signal back to red. */
02238           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02239           MarkTileDirtyByTile(tile);
02240         }
02241       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02242         break;
02243       }
02244     }
02245 
02246     /* Don't free first station/bridge/tunnel if we are on it. */
02247     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);
02248 
02249     free_tile = true;
02250   }
02251 }
02252 
02253 static const byte _initial_tile_subcoord[6][4][3] = {
02254 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02255 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02256 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02257 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02258 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02259 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02260 };
02261 
02274 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02275 {
02276   switch (_settings_game.pf.pathfinder_for_trains) {
02277     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02278     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02279 
02280     default: NOT_REACHED();
02281   }
02282 }
02283 
02289 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02290 {
02291   PBSTileInfo origin = FollowTrainReservation(v);
02292 
02293   CFollowTrackRail ft(v);
02294 
02295   TileIndex tile = origin.tile;
02296   Trackdir  cur_td = origin.trackdir;
02297   while (ft.Follow(tile, cur_td)) {
02298     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02299       /* Possible signal tile. */
02300       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02301     }
02302 
02303     if (_settings_game.pf.forbid_90_deg) {
02304       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02305       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02306     }
02307 
02308     /* Station, depot or waypoint are a possible target. */
02309     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02310     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02311       /* Choice found or possible target encountered.
02312        * On finding a possible target, we need to stop and let the pathfinder handle the
02313        * remaining path. This is because we don't know if this target is in one of our
02314        * orders, so we might cause pathfinding to fail later on if we find a choice.
02315        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02316        * a wrong path not leading to our next destination. */
02317       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02318 
02319       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02320        * actually starts its search at the first unreserved tile. */
02321       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02322 
02323       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02324       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02325       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02326       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02327     }
02328 
02329     tile = ft.m_new_tile;
02330     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02331 
02332     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02333       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02334       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02335       /* Safe position is all good, path valid and okay. */
02336       return PBSTileInfo(tile, cur_td, true);
02337     }
02338 
02339     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02340   }
02341 
02342   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02343     /* End of line, path valid and okay. */
02344     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02345   }
02346 
02347   /* Sorry, can't reserve path, back out. */
02348   tile = origin.tile;
02349   cur_td = origin.trackdir;
02350   TileIndex stopped = ft.m_old_tile;
02351   Trackdir  stopped_td = ft.m_old_td;
02352   while (tile != stopped || cur_td != stopped_td) {
02353     if (!ft.Follow(tile, cur_td)) break;
02354 
02355     if (_settings_game.pf.forbid_90_deg) {
02356       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02357       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02358     }
02359     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02360 
02361     tile = ft.m_new_tile;
02362     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02363 
02364     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02365   }
02366 
02367   /* Path invalid. */
02368   return PBSTileInfo();
02369 }
02370 
02381 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02382 {
02383   switch (_settings_game.pf.pathfinder_for_trains) {
02384     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02385     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02386 
02387     default: NOT_REACHED();
02388   }
02389 }
02390 
02392 class VehicleOrderSaver {
02393 private:
02394   Train          *v;
02395   Order          old_order;
02396   TileIndex      old_dest_tile;
02397   StationID      old_last_station_visited;
02398   VehicleOrderID index;
02399   bool           suppress_implicit_orders;
02400 
02401 public:
02402   VehicleOrderSaver(Train *_v) :
02403     v(_v),
02404     old_order(_v->current_order),
02405     old_dest_tile(_v->dest_tile),
02406     old_last_station_visited(_v->last_station_visited),
02407     index(_v->cur_real_order_index),
02408     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02409   {
02410   }
02411 
02412   ~VehicleOrderSaver()
02413   {
02414     this->v->current_order = this->old_order;
02415     this->v->dest_tile = this->old_dest_tile;
02416     this->v->last_station_visited = this->old_last_station_visited;
02417     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02418   }
02419 
02425   bool SwitchToNextOrder(bool skip_first)
02426   {
02427     if (this->v->GetNumOrders() == 0) return false;
02428 
02429     if (skip_first) ++this->index;
02430 
02431     int depth = 0;
02432 
02433     do {
02434       /* Wrap around. */
02435       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02436 
02437       Order *order = this->v->GetOrder(this->index);
02438       assert(order != NULL);
02439 
02440       switch (order->GetType()) {
02441         case OT_GOTO_DEPOT:
02442           /* Skip service in depot orders when the train doesn't need service. */
02443           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02444         case OT_GOTO_STATION:
02445         case OT_GOTO_WAYPOINT:
02446           this->v->current_order = *order;
02447           return UpdateOrderDest(this->v, order, 0, true);
02448         case OT_CONDITIONAL: {
02449           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02450           if (next != INVALID_VEH_ORDER_ID) {
02451             depth++;
02452             this->index = next;
02453             /* Don't increment next, so no break here. */
02454             continue;
02455           }
02456           break;
02457         }
02458         default:
02459           break;
02460       }
02461       /* Don't increment inside the while because otherwise conditional
02462        * orders can lead to an infinite loop. */
02463       ++this->index;
02464       depth++;
02465     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02466 
02467     return false;
02468   }
02469 };
02470 
02471 /* choose a track */
02472 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02473 {
02474   Track best_track = INVALID_TRACK;
02475   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02476   bool changed_signal = false;
02477 
02478   assert((tracks & ~TRACK_BIT_MASK) == 0);
02479 
02480   if (got_reservation != NULL) *got_reservation = false;
02481 
02482   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02483   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02484   /* Do we have a suitable reserved track? */
02485   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02486 
02487   /* Quick return in case only one possible track is available */
02488   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02489     Track track = FindFirstTrack(tracks);
02490     /* We need to check for signals only here, as a junction tile can't have signals. */
02491     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02492       do_track_reservation = true;
02493       changed_signal = true;
02494       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02495     } else if (!do_track_reservation) {
02496       return track;
02497     }
02498     best_track = track;
02499   }
02500 
02501   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02502   DiagDirection dest_enterdir = enterdir;
02503   if (do_track_reservation) {
02504     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02505     if (res_dest.tile == INVALID_TILE) {
02506       /* Reservation failed? */
02507       if (mark_stuck) MarkTrainAsStuck(v);
02508       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02509       return FindFirstTrack(tracks);
02510     }
02511     if (res_dest.okay) {
02512       /* Got a valid reservation that ends at a safe target, quick exit. */
02513       if (got_reservation != NULL) *got_reservation = true;
02514       if (changed_signal) MarkTileDirtyByTile(tile);
02515       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02516       return best_track;
02517     }
02518 
02519     /* Check if the train needs service here, so it has a chance to always find a depot.
02520      * Also check if the current order is a service order so we don't reserve a path to
02521      * the destination but instead to the next one if service isn't needed. */
02522     CheckIfTrainNeedsService(v);
02523     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02524   }
02525 
02526   /* Save the current train order. The destructor will restore the old order on function exit. */
02527   VehicleOrderSaver orders(v);
02528 
02529   /* If the current tile is the destination of the current order and
02530    * a reservation was requested, advance to the next order.
02531    * Don't advance on a depot order as depots are always safe end points
02532    * for a path and no look-ahead is necessary. This also avoids a
02533    * problem with depot orders not part of the order list when the
02534    * order list itself is empty. */
02535   if (v->current_order.IsType(OT_LEAVESTATION)) {
02536     orders.SwitchToNextOrder(false);
02537   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02538       v->current_order.IsType(OT_GOTO_STATION) ?
02539       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02540       v->tile == v->dest_tile))) {
02541     orders.SwitchToNextOrder(true);
02542   }
02543 
02544   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02545     /* Pathfinders are able to tell that route was only 'guessed'. */
02546     bool      path_found = true;
02547     TileIndex new_tile = res_dest.tile;
02548 
02549     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02550     if (new_tile == tile) best_track = next_track;
02551     v->HandlePathfindingResult(path_found);
02552   }
02553 
02554   /* No track reservation requested -> finished. */
02555   if (!do_track_reservation) return best_track;
02556 
02557   /* A path was found, but could not be reserved. */
02558   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02559     if (mark_stuck) MarkTrainAsStuck(v);
02560     FreeTrainTrackReservation(v);
02561     return best_track;
02562   }
02563 
02564   /* No possible reservation target found, we are probably lost. */
02565   if (res_dest.tile == INVALID_TILE) {
02566     /* Try to find any safe destination. */
02567     PBSTileInfo origin = FollowTrainReservation(v);
02568     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02569       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02570       best_track = FindFirstTrack(res);
02571       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02572       if (got_reservation != NULL) *got_reservation = true;
02573       if (changed_signal) MarkTileDirtyByTile(tile);
02574     } else {
02575       FreeTrainTrackReservation(v);
02576       if (mark_stuck) MarkTrainAsStuck(v);
02577     }
02578     return best_track;
02579   }
02580 
02581   if (got_reservation != NULL) *got_reservation = true;
02582 
02583   /* Reservation target found and free, check if it is safe. */
02584   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02585     /* Extend reservation until we have found a safe position. */
02586     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02587     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02588     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02589     if (_settings_game.pf.forbid_90_deg) {
02590       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02591     }
02592 
02593     /* Get next order with destination. */
02594     if (orders.SwitchToNextOrder(true)) {
02595       PBSTileInfo cur_dest;
02596       bool path_found;
02597       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02598       if (cur_dest.tile != INVALID_TILE) {
02599         res_dest = cur_dest;
02600         if (res_dest.okay) continue;
02601         /* Path found, but could not be reserved. */
02602         FreeTrainTrackReservation(v);
02603         if (mark_stuck) MarkTrainAsStuck(v);
02604         if (got_reservation != NULL) *got_reservation = false;
02605         changed_signal = false;
02606         break;
02607       }
02608     }
02609     /* No order or no safe position found, try any position. */
02610     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02611       FreeTrainTrackReservation(v);
02612       if (mark_stuck) MarkTrainAsStuck(v);
02613       if (got_reservation != NULL) *got_reservation = false;
02614       changed_signal = false;
02615     }
02616     break;
02617   }
02618 
02619   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02620 
02621   if (changed_signal) MarkTileDirtyByTile(tile);
02622 
02623   return best_track;
02624 }
02625 
02634 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02635 {
02636   assert(v->IsFrontEngine());
02637 
02638   /* We have to handle depots specially as the track follower won't look
02639    * at the depot tile itself but starts from the next tile. If we are still
02640    * inside the depot, a depot reservation can never be ours. */
02641   if (v->track == TRACK_BIT_DEPOT) {
02642     if (HasDepotReservation(v->tile)) {
02643       if (mark_as_stuck) MarkTrainAsStuck(v);
02644       return false;
02645     } else {
02646       /* Depot not reserved, but the next tile might be. */
02647       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02648       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02649     }
02650   }
02651 
02652   Vehicle *other_train = NULL;
02653   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02654   /* The path we are driving on is already blocked by some other train.
02655    * This can only happen in certain situations when mixing path and
02656    * block signals or when changing tracks and/or signals.
02657    * Exit here as doing any further reservations will probably just
02658    * make matters worse. */
02659   if (other_train != NULL && other_train->index != v->index) {
02660     if (mark_as_stuck) MarkTrainAsStuck(v);
02661     return false;
02662   }
02663   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02664   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02665     /* Can't be stuck then. */
02666     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02667     ClrBit(v->flags, VRF_TRAIN_STUCK);
02668     return true;
02669   }
02670 
02671   /* If we are in a depot, tentatively reserve the depot. */
02672   if (v->track == TRACK_BIT_DEPOT) {
02673     SetDepotReservation(v->tile, true);
02674     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02675   }
02676 
02677   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02678   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02679   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02680 
02681   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02682 
02683   bool res_made = false;
02684   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02685 
02686   if (!res_made) {
02687     /* Free the depot reservation as well. */
02688     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02689     return false;
02690   }
02691 
02692   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02693     v->wait_counter = 0;
02694     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02695   }
02696   ClrBit(v->flags, VRF_TRAIN_STUCK);
02697   return true;
02698 }
02699 
02700 
02701 static bool CheckReverseTrain(const Train *v)
02702 {
02703   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02704       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02705       !(v->direction & 1)) {
02706     return false;
02707   }
02708 
02709   assert(v->track != TRACK_BIT_NONE);
02710 
02711   switch (_settings_game.pf.pathfinder_for_trains) {
02712     case VPF_NPF: return NPFTrainCheckReverse(v);
02713     case VPF_YAPF: return YapfTrainCheckReverse(v);
02714 
02715     default: NOT_REACHED();
02716   }
02717 }
02718 
02724 TileIndex Train::GetOrderStationLocation(StationID station)
02725 {
02726   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02727 
02728   const Station *st = Station::Get(station);
02729   if (!(st->facilities & FACIL_TRAIN)) {
02730     /* The destination station has no trainstation tiles. */
02731     this->IncrementRealOrderIndex();
02732     return 0;
02733   }
02734 
02735   return st->xy;
02736 }
02737 
02739 void Train::MarkDirty()
02740 {
02741   Train *v = this;
02742   do {
02743     v->UpdateViewport(false, false);
02744   } while ((v = v->Next()) != NULL);
02745 
02746   /* need to update acceleration and cached values since the goods on the train changed. */
02747   this->CargoChanged();
02748   this->UpdateAcceleration();
02749 }
02750 
02758 int Train::UpdateSpeed()
02759 {
02760   switch (_settings_game.vehicle.train_acceleration_model) {
02761     default: NOT_REACHED();
02762     case AM_ORIGINAL:
02763       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, min(this->gcache.cached_max_track_speed, this->current_order.max_speed));
02764 
02765     case AM_REALISTIC:
02766       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02767   }
02768 }
02769 
02775 static void TrainEnterStation(Train *v, StationID station)
02776 {
02777   v->last_station_visited = station;
02778 
02779   /* check if a train ever visited this station before */
02780   Station *st = Station::Get(station);
02781   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02782     st->had_vehicle_of_type |= HVOT_TRAIN;
02783     SetDParam(0, st->index);
02784     AddVehicleNewsItem(
02785       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02786       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
02787       v->index,
02788       st->index
02789     );
02790     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02791     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02792   }
02793 
02794   v->force_proceed = TFP_NONE;
02795   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02796 
02797   v->BeginLoading();
02798 
02799   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02800 }
02801 
02802 /* Check if the vehicle is compatible with the specified tile */
02803 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02804 {
02805   return IsTileOwner(tile, v->owner) &&
02806       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02807 }
02808 
02810 struct AccelerationSlowdownParams {
02811   byte small_turn; 
02812   byte large_turn; 
02813   byte z_up;       
02814   byte z_down;     
02815 };
02816 
02818 static const AccelerationSlowdownParams _accel_slowdown[] = {
02819   /* normal accel */
02820   {256 / 4, 256 / 2, 256 / 4, 2}, 
02821   {256 / 4, 256 / 2, 256 / 4, 2}, 
02822   {0,       256 / 2, 256 / 4, 2}, 
02823 };
02824 
02830 static inline void AffectSpeedByZChange(Train *v, int old_z)
02831 {
02832   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02833 
02834   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02835 
02836   if (old_z < v->z_pos) {
02837     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02838   } else {
02839     uint16 spd = v->cur_speed + asp->z_down;
02840     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02841   }
02842 }
02843 
02844 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02845 {
02846   if (IsTileType(tile, MP_RAILWAY) &&
02847       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02848     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02849     Trackdir trackdir = FindFirstTrackdir(tracks);
02850     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02851       /* A PBS block with a non-PBS signal facing us? */
02852       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02853     }
02854   }
02855   return false;
02856 }
02857 
02859 void Train::ReserveTrackUnderConsist() const
02860 {
02861   for (const Train *u = this; u != NULL; u = u->Next()) {
02862     switch (u->track) {
02863       case TRACK_BIT_WORMHOLE:
02864         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02865         break;
02866       case TRACK_BIT_DEPOT:
02867         break;
02868       default:
02869         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02870         break;
02871     }
02872   }
02873 }
02874 
02881 uint Train::Crash(bool flooded)
02882 {
02883   uint pass = 0;
02884   if (this->IsFrontEngine()) {
02885     pass += 2; // driver
02886 
02887     /* Remove the reserved path in front of the train if it is not stuck.
02888      * Also clear all reserved tracks the train is currently on. */
02889     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02890     for (const Train *v = this; v != NULL; v = v->Next()) {
02891       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02892       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02893         /* ClearPathReservation will not free the wormhole exit
02894          * if the train has just entered the wormhole. */
02895         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02896       }
02897     }
02898 
02899     /* we may need to update crossing we were approaching,
02900      * but must be updated after the train has been marked crashed */
02901     TileIndex crossing = TrainApproachingCrossingTile(this);
02902     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02903 
02904     /* Remove the loading indicators (if any) */
02905     HideFillingPercent(&this->fill_percent_te_id);
02906   }
02907 
02908   pass += this->GroundVehicleBase::Crash(flooded);
02909 
02910   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02911   return pass;
02912 }
02913 
02920 static uint TrainCrashed(Train *v)
02921 {
02922   uint num = 0;
02923 
02924   /* do not crash train twice */
02925   if (!(v->vehstatus & VS_CRASHED)) {
02926     num = v->Crash();
02927     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02928     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02929   }
02930 
02931   /* Try to re-reserve track under already crashed train too.
02932    * Crash() clears the reservation! */
02933   v->ReserveTrackUnderConsist();
02934 
02935   return num;
02936 }
02937 
02939 struct TrainCollideChecker {
02940   Train *v; 
02941   uint num; 
02942 };
02943 
02950 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02951 {
02952   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02953 
02954   /* not a train or in depot */
02955   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02956 
02957   /* do not crash into trains of another company. */
02958   if (v->owner != tcc->v->owner) return NULL;
02959 
02960   /* get first vehicle now to make most usual checks faster */
02961   Train *coll = Train::From(v)->First();
02962 
02963   /* can't collide with own wagons */
02964   if (coll == tcc->v) return NULL;
02965 
02966   int x_diff = v->x_pos - tcc->v->x_pos;
02967   int y_diff = v->y_pos - tcc->v->y_pos;
02968 
02969   /* Do fast calculation to check whether trains are not in close vicinity
02970    * and quickly reject trains distant enough for any collision.
02971    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02972    * Differences are then ORed and then we check for any higher bits */
02973   uint hash = (y_diff + 7) | (x_diff + 7);
02974   if (hash & ~15) return NULL;
02975 
02976   /* Slower check using multiplication */
02977   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02978   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02979 
02980   /* Happens when there is a train under bridge next to bridge head */
02981   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02982 
02983   /* crash both trains */
02984   tcc->num += TrainCrashed(tcc->v);
02985   tcc->num += TrainCrashed(coll);
02986 
02987   return NULL; // continue searching
02988 }
02989 
02997 static bool CheckTrainCollision(Train *v)
02998 {
02999   /* can't collide in depot */
03000   if (v->track == TRACK_BIT_DEPOT) return false;
03001 
03002   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03003 
03004   TrainCollideChecker tcc;
03005   tcc.v = v;
03006   tcc.num = 0;
03007 
03008   /* find colliding vehicles */
03009   if (v->track == TRACK_BIT_WORMHOLE) {
03010     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03011     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03012   } else {
03013     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03014   }
03015 
03016   /* any dead -> no crash */
03017   if (tcc.num == 0) return false;
03018 
03019   SetDParam(0, tcc.num);
03020   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH,
03021     NS_ACCIDENT,
03022     v->index
03023   );
03024 
03025   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03026   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03027   return true;
03028 }
03029 
03030 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03031 {
03032   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03033 
03034   Train *t = Train::From(v);
03035   DiagDirection exitdir = *(DiagDirection *)data;
03036 
03037   /* not front engine of a train, inside wormhole or depot, crashed */
03038   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03039 
03040   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03041 
03042   return t;
03043 }
03044 
03052 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03053 {
03054   Train *first = v->First();
03055   Train *prev;
03056   bool direction_changed = false; // has direction of any part changed?
03057 
03058   /* For every vehicle after and including the given vehicle */
03059   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03060     DiagDirection enterdir = DIAGDIR_BEGIN;
03061     bool update_signals_crossing = false; // will we update signals or crossing state?
03062 
03063     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03064     if (v->track != TRACK_BIT_WORMHOLE) {
03065       /* Not inside tunnel */
03066       if (gp.old_tile == gp.new_tile) {
03067         /* Staying in the old tile */
03068         if (v->track == TRACK_BIT_DEPOT) {
03069           /* Inside depot */
03070           gp.x = v->x_pos;
03071           gp.y = v->y_pos;
03072         } else {
03073           /* Not inside depot */
03074 
03075           /* Reverse when we are at the end of the track already, do not move to the new position */
03076           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03077 
03078           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03079           if (HasBit(r, VETS_CANNOT_ENTER)) {
03080             goto invalid_rail;
03081           }
03082           if (HasBit(r, VETS_ENTERED_STATION)) {
03083             /* The new position is the end of the platform */
03084             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03085           }
03086         }
03087       } else {
03088         /* A new tile is about to be entered. */
03089 
03090         /* Determine what direction we're entering the new tile from */
03091         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03092         assert(IsValidDiagDirection(enterdir));
03093 
03094         /* Get the status of the tracks in the new tile and mask
03095          * away the bits that aren't reachable. */
03096         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03097         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03098 
03099         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03100         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03101 
03102         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03103         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03104           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03105            * can be switched on halfway a turn */
03106           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03107         }
03108 
03109         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03110 
03111         /* Check if the new tile constrains tracks that are compatible
03112          * with the current train, if not, bail out. */
03113         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03114 
03115         TrackBits chosen_track;
03116         if (prev == NULL) {
03117           /* Currently the locomotive is active. Determine which one of the
03118            * available tracks to choose */
03119           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03120           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03121 
03122           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03123             /* For each signal we find decrease the counter by one.
03124              * We start at two, so the first signal we pass decreases
03125              * this to one, then if we reach the next signal it is
03126              * decreased to zero and we won't pass that new signal. */
03127             Trackdir dir = FindFirstTrackdir(trackdirbits);
03128             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03129                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03130               /* However, we do not want to be stopped by PBS signals
03131                * entered via the back. */
03132               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03133               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03134             }
03135           }
03136 
03137           /* Check if it's a red signal and that force proceed is not clicked. */
03138           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03139             /* In front of a red signal */
03140             Trackdir i = FindFirstTrackdir(trackdirbits);
03141 
03142             /* Don't handle stuck trains here. */
03143             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03144 
03145             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03146               v->cur_speed = 0;
03147               v->subspeed = 0;
03148               v->progress = 255 - 100;
03149               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03150             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03151               v->cur_speed = 0;
03152               v->subspeed = 0;
03153               v->progress = 255 - 10;
03154               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03155                 DiagDirection exitdir = TrackdirToExitdir(i);
03156                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03157 
03158                 exitdir = ReverseDiagDir(exitdir);
03159 
03160                 /* check if a train is waiting on the other side */
03161                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03162               }
03163             }
03164 
03165             /* If we would reverse but are currently in a PBS block and
03166              * reversing of stuck trains is disabled, don't reverse.
03167              * This does not apply if the reason for reversing is a one-way
03168              * signal blocking us, because a train would then be stuck forever. */
03169             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03170                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03171               v->wait_counter = 0;
03172               return false;
03173             }
03174             goto reverse_train_direction;
03175           } else {
03176             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03177           }
03178         } else {
03179           /* The wagon is active, simply follow the prev vehicle. */
03180           if (prev->tile == gp.new_tile) {
03181             /* Choose the same track as prev */
03182             if (prev->track == TRACK_BIT_WORMHOLE) {
03183               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03184                * However, just choose the track into the wormhole. */
03185               assert(IsTunnel(prev->tile));
03186               chosen_track = bits;
03187             } else {
03188               chosen_track = prev->track;
03189             }
03190           } else {
03191             /* Choose the track that leads to the tile where prev is.
03192              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03193              * I.e. when the tile between them has only space for a single vehicle like
03194              *  1) horizontal/vertical track tiles and
03195              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03196              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03197              */
03198             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03199               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03200               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03201               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03202               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03203             };
03204             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03205             assert(IsValidDiagDirection(exitdir));
03206             chosen_track = _connecting_track[enterdir][exitdir];
03207           }
03208           chosen_track &= bits;
03209         }
03210 
03211         /* Make sure chosen track is a valid track */
03212         assert(
03213             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03214             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03215             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03216 
03217         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03218         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03219         gp.x = (gp.x & ~0xF) | b[0];
03220         gp.y = (gp.y & ~0xF) | b[1];
03221         Direction chosen_dir = (Direction)b[2];
03222 
03223         /* Call the landscape function and tell it that the vehicle entered the tile */
03224         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03225         if (HasBit(r, VETS_CANNOT_ENTER)) {
03226           goto invalid_rail;
03227         }
03228 
03229         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03230           Track track = FindFirstTrack(chosen_track);
03231           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03232           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03233             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03234             MarkTileDirtyByTile(gp.new_tile);
03235           }
03236 
03237           /* Clear any track reservation when the last vehicle leaves the tile */
03238           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03239 
03240           v->tile = gp.new_tile;
03241 
03242           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03243             v->First()->ConsistChanged(true);
03244           }
03245 
03246           v->track = chosen_track;
03247           assert(v->track);
03248         }
03249 
03250         /* We need to update signal status, but after the vehicle position hash
03251          * has been updated by UpdateInclination() */
03252         update_signals_crossing = true;
03253 
03254         if (chosen_dir != v->direction) {
03255           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03256             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03257             DirDiff diff = DirDifference(v->direction, chosen_dir);
03258             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03259           }
03260           direction_changed = true;
03261           v->direction = chosen_dir;
03262         }
03263 
03264         if (v->IsFrontEngine()) {
03265           v->wait_counter = 0;
03266 
03267           /* If we are approaching a crossing that is reserved, play the sound now. */
03268           TileIndex crossing = TrainApproachingCrossingTile(v);
03269           if (crossing != INVALID_TILE && HasCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03270 
03271           /* Always try to extend the reservation when entering a tile. */
03272           CheckNextTrainTile(v);
03273         }
03274 
03275         if (HasBit(r, VETS_ENTERED_STATION)) {
03276           /* The new position is the location where we want to stop */
03277           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03278         }
03279       }
03280     } else {
03281       /* In a tunnel or on a bridge
03282        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03283        * - for bridges, only the middle part - without the bridge heads */
03284       if (!(v->vehstatus & VS_HIDDEN)) {
03285         Train *first = v->First();
03286         first->cur_speed = min(first->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03287       }
03288 
03289       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03290         /* Perform look-ahead on tunnel exit. */
03291         if (v->IsFrontEngine()) {
03292           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03293           CheckNextTrainTile(v);
03294         }
03295         /* Prevent v->UpdateInclination() being called with wrong parameters.
03296          * This could happen if the train was reversed inside the tunnel/bridge. */
03297         if (gp.old_tile == gp.new_tile) {
03298           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03299         }
03300       } else {
03301         v->x_pos = gp.x;
03302         v->y_pos = gp.y;
03303         VehicleUpdatePosition(v);
03304         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03305         continue;
03306       }
03307     }
03308 
03309     /* update image of train, as well as delta XY */
03310     v->UpdateDeltaXY(v->direction);
03311 
03312     v->x_pos = gp.x;
03313     v->y_pos = gp.y;
03314     VehicleUpdatePosition(v);
03315 
03316     /* update the Z position of the vehicle */
03317     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03318 
03319     if (prev == NULL) {
03320       /* This is the first vehicle in the train */
03321       AffectSpeedByZChange(v, old_z);
03322     }
03323 
03324     if (update_signals_crossing) {
03325       if (v->IsFrontEngine()) {
03326         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03327           /* We are entering a block with PBS signals right now, but
03328            * not through a PBS signal. This means we don't have a
03329            * reservation right now. As a conventional signal will only
03330            * ever be green if no other train is in the block, getting
03331            * a path should always be possible. If the player built
03332            * such a strange network that it is not possible, the train
03333            * will be marked as stuck and the player has to deal with
03334            * the problem. */
03335           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03336               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03337               !TryPathReserve(v)) {
03338             MarkTrainAsStuck(v);
03339           }
03340         }
03341       }
03342 
03343       /* Signals can only change when the first
03344        * (above) or the last vehicle moves. */
03345       if (v->Next() == NULL) {
03346         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03347         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03348       }
03349     }
03350 
03351     /* Do not check on every tick to save some computing time. */
03352     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03353   }
03354 
03355   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03356 
03357   return true;
03358 
03359 invalid_rail:
03360   /* We've reached end of line?? */
03361   if (prev != NULL) error("Disconnecting train");
03362 
03363 reverse_train_direction:
03364   if (reverse) {
03365     v->wait_counter = 0;
03366     v->cur_speed = 0;
03367     v->subspeed = 0;
03368     ReverseTrainDirection(v);
03369   }
03370 
03371   return false;
03372 }
03373 
03380 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03381 {
03382   TrackBits *trackbits = (TrackBits *)data;
03383 
03384   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03385     TrackBits train_tbits = Train::From(v)->track;
03386     if (train_tbits == TRACK_BIT_WORMHOLE) {
03387       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03388       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03389     } else if (train_tbits != TRACK_BIT_DEPOT) {
03390       *trackbits |= train_tbits;
03391     }
03392   }
03393 
03394   return NULL;
03395 }
03396 
03404 static void DeleteLastWagon(Train *v)
03405 {
03406   Train *first = v->First();
03407 
03408   /* Go to the last wagon and delete the link pointing there
03409    * *u is then the one-before-last wagon, and *v the last
03410    * one which will physically be removed */
03411   Train *u = v;
03412   for (; v->Next() != NULL; v = v->Next()) u = v;
03413   u->SetNext(NULL);
03414 
03415   if (first != v) {
03416     /* Recalculate cached train properties */
03417     first->ConsistChanged(false);
03418     /* Update the depot window if the first vehicle is in depot -
03419      * if v == first, then it is updated in PreDestructor() */
03420     if (first->track == TRACK_BIT_DEPOT) {
03421       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03422     }
03423   }
03424 
03425   /* 'v' shouldn't be accessed after it has been deleted */
03426   TrackBits trackbits = v->track;
03427   TileIndex tile = v->tile;
03428   Owner owner = v->owner;
03429 
03430   delete v;
03431   v = NULL; // make sure nobody will try to read 'v' anymore
03432 
03433   if (trackbits == TRACK_BIT_WORMHOLE) {
03434     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03435     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03436   }
03437 
03438   Track track = TrackBitsToTrack(trackbits);
03439   if (HasReservedTracks(tile, trackbits)) {
03440     UnreserveRailTrack(tile, track);
03441 
03442     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03443     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03444     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03445 
03446     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03447     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03448     Track t;
03449     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03450   }
03451 
03452   /* check if the wagon was on a road/rail-crossing */
03453   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03454 
03455   /* Update signals */
03456   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03457     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03458   } else {
03459     SetSignalsOnBothDir(tile, track, owner);
03460   }
03461 }
03462 
03467 static void ChangeTrainDirRandomly(Train *v)
03468 {
03469   static const DirDiff delta[] = {
03470     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03471   };
03472 
03473   do {
03474     /* We don't need to twist around vehicles if they're not visible */
03475     if (!(v->vehstatus & VS_HIDDEN)) {
03476       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03477       v->UpdateDeltaXY(v->direction);
03478       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03479       /* Refrain from updating the z position of the vehicle when on
03480        * a bridge, because UpdateInclination() will put the vehicle under
03481        * the bridge in that case */
03482       if (v->track != TRACK_BIT_WORMHOLE) {
03483         VehicleUpdatePosition(v);
03484         v->UpdateInclination(false, false);
03485       }
03486     }
03487   } while ((v = v->Next()) != NULL);
03488 }
03489 
03495 static bool HandleCrashedTrain(Train *v)
03496 {
03497   int state = ++v->crash_anim_pos;
03498 
03499   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03500     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03501   }
03502 
03503   uint32 r;
03504   if (state <= 200 && Chance16R(1, 7, r)) {
03505     int index = (r * 10 >> 16);
03506 
03507     Vehicle *u = v;
03508     do {
03509       if (--index < 0) {
03510         r = Random();
03511 
03512         CreateEffectVehicleRel(u,
03513           GB(r,  8, 3) + 2,
03514           GB(r, 16, 3) + 2,
03515           GB(r,  0, 3) + 5,
03516           EV_EXPLOSION_SMALL);
03517         break;
03518       }
03519     } while ((u = u->Next()) != NULL);
03520   }
03521 
03522   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03523 
03524   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03525     bool ret = v->Next() != NULL;
03526     DeleteLastWagon(v);
03527     return ret;
03528   }
03529 
03530   return true;
03531 }
03532 
03534 static const uint16 _breakdown_speeds[16] = {
03535   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03536 };
03537 
03538 
03547 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03548 {
03549   /* Calc position within the current tile */
03550   uint x = v->x_pos & 0xF;
03551   uint y = v->y_pos & 0xF;
03552 
03553   /* for diagonal directions, 'x' will be 0..15 -
03554    * for other directions, it will be 1, 3, 5, ..., 15 */
03555   switch (v->direction) {
03556     case DIR_N : x = ~x + ~y + 25; break;
03557     case DIR_NW: x = y;            // FALL THROUGH
03558     case DIR_NE: x = ~x + 16;      break;
03559     case DIR_E : x = ~x + y + 9;   break;
03560     case DIR_SE: x = y;            break;
03561     case DIR_S : x = x + y - 7;    break;
03562     case DIR_W : x = ~y + x + 9;   break;
03563     default: break;
03564   }
03565 
03566   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03567    * does not cross the tile boundary when we do reverse, but as the vehicle's
03568    * location is based on their center, use half a vehicle's length as offset.
03569    * Multiply the half-length by two for straight directions to compensate that
03570    * we only get odd x offsets there. */
03571   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03572     /* we are too near the tile end, reverse now */
03573     v->cur_speed = 0;
03574     if (reverse) ReverseTrainDirection(v);
03575     return false;
03576   }
03577 
03578   /* slow down */
03579   v->vehstatus |= VS_TRAIN_SLOWING;
03580   uint16 break_speed = _breakdown_speeds[x & 0xF];
03581   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03582 
03583   return true;
03584 }
03585 
03586 
03592 static bool TrainCanLeaveTile(const Train *v)
03593 {
03594   /* Exit if inside a tunnel/bridge or a depot */
03595   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03596 
03597   TileIndex tile = v->tile;
03598 
03599   /* entering a tunnel/bridge? */
03600   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03601     DiagDirection dir = GetTunnelBridgeDirection(tile);
03602     if (DiagDirToDir(dir) == v->direction) return false;
03603   }
03604 
03605   /* entering a depot? */
03606   if (IsRailDepotTile(tile)) {
03607     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03608     if (DiagDirToDir(dir) == v->direction) return false;
03609   }
03610 
03611   return true;
03612 }
03613 
03614 
03622 static TileIndex TrainApproachingCrossingTile(const Train *v)
03623 {
03624   assert(v->IsFrontEngine());
03625   assert(!(v->vehstatus & VS_CRASHED));
03626 
03627   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03628 
03629   DiagDirection dir = TrainExitDir(v->direction, v->track);
03630   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03631 
03632   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03633   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03634       !CheckCompatibleRail(v, tile)) {
03635     return INVALID_TILE;
03636   }
03637 
03638   return tile;
03639 }
03640 
03641 
03649 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03650 {
03651   /* First, handle broken down train */
03652 
03653   int t = v->breakdown_ctr;
03654   if (t > 1) {
03655     v->vehstatus |= VS_TRAIN_SLOWING;
03656 
03657     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03658     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03659   } else {
03660     v->vehstatus &= ~VS_TRAIN_SLOWING;
03661   }
03662 
03663   if (!TrainCanLeaveTile(v)) return true;
03664 
03665   /* Determine the non-diagonal direction in which we will exit this tile */
03666   DiagDirection dir = TrainExitDir(v->direction, v->track);
03667   /* Calculate next tile */
03668   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03669 
03670   /* Determine the track status on the next tile */
03671   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03672   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03673 
03674   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03675   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03676 
03677   /* We are sure the train is not entering a depot, it is detected above */
03678 
03679   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03680   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03681   if (_settings_game.pf.forbid_90_deg) {
03682     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03683   }
03684 
03685   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03686   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03687     return TrainApproachingLineEnd(v, false, reverse);
03688   }
03689 
03690   /* approaching red signal */
03691   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03692 
03693   /* approaching a rail/road crossing? then make it red */
03694   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03695 
03696   return true;
03697 }
03698 
03699 
03700 static bool TrainLocoHandler(Train *v, bool mode)
03701 {
03702   /* train has crashed? */
03703   if (v->vehstatus & VS_CRASHED) {
03704     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03705   }
03706 
03707   if (v->force_proceed != TFP_NONE) {
03708     ClrBit(v->flags, VRF_TRAIN_STUCK);
03709     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03710   }
03711 
03712   /* train is broken down? */
03713   if (v->HandleBreakdown()) return true;
03714 
03715   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03716     ReverseTrainDirection(v);
03717   }
03718 
03719   /* exit if train is stopped */
03720   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03721 
03722   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03723   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03724     v->wait_counter = 0;
03725     v->cur_speed = 0;
03726     v->subspeed = 0;
03727     ClrBit(v->flags, VRF_LEAVING_STATION);
03728     ReverseTrainDirection(v);
03729     return true;
03730   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03731     /* Try to reserve a path when leaving the station as we
03732      * might not be marked as wanting a reservation, e.g.
03733      * when an overlength train gets turned around in a station. */
03734     DiagDirection dir = TrainExitDir(v->direction, v->track);
03735     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03736 
03737     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03738       TryPathReserve(v, true, true);
03739     }
03740     ClrBit(v->flags, VRF_LEAVING_STATION);
03741   }
03742 
03743   v->HandleLoading(mode);
03744 
03745   if (v->current_order.IsType(OT_LOADING)) return true;
03746 
03747   if (CheckTrainStayInDepot(v)) return true;
03748 
03749   if (!mode) v->ShowVisualEffect();
03750 
03751   /* We had no order but have an order now, do look ahead. */
03752   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03753     CheckNextTrainTile(v);
03754   }
03755 
03756   /* Handle stuck trains. */
03757   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03758     ++v->wait_counter;
03759 
03760     /* Should we try reversing this tick if still stuck? */
03761     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03762 
03763     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03764     if (!TryPathReserve(v)) {
03765       /* Still stuck. */
03766       if (turn_around) ReverseTrainDirection(v);
03767 
03768       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03769         /* Show message to player. */
03770         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03771           SetDParam(0, v->index);
03772           AddVehicleNewsItem(
03773             STR_NEWS_TRAIN_IS_STUCK,
03774             NS_ADVICE,
03775             v->index
03776           );
03777         }
03778         v->wait_counter = 0;
03779       }
03780       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03781       if (v->force_proceed == TFP_NONE) return true;
03782       ClrBit(v->flags, VRF_TRAIN_STUCK);
03783       v->wait_counter = 0;
03784       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03785     }
03786   }
03787 
03788   if (v->current_order.IsType(OT_LEAVESTATION)) {
03789     v->current_order.Free();
03790     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03791     return true;
03792   }
03793 
03794   int j = v->UpdateSpeed();
03795 
03796   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03797   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03798     /* If we manually stopped, we're not force-proceeding anymore. */
03799     v->force_proceed = TFP_NONE;
03800     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03801   }
03802 
03803   int adv_spd = v->GetAdvanceDistance();
03804   if (j < adv_spd) {
03805     /* if the vehicle has speed 0, update the last_speed field. */
03806     if (v->cur_speed == 0) v->SetLastSpeed();
03807   } else {
03808     TrainCheckIfLineEnds(v);
03809     /* Loop until the train has finished moving. */
03810     for (;;) {
03811       j -= adv_spd;
03812       TrainController(v, NULL);
03813       /* Don't continue to move if the train crashed. */
03814       if (CheckTrainCollision(v)) break;
03815       /* Determine distance to next map position */
03816       adv_spd = v->GetAdvanceDistance();
03817 
03818       /* No more moving this tick */
03819       if (j < adv_spd || v->cur_speed == 0) break;
03820 
03821       OrderType order_type = v->current_order.GetType();
03822       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03823       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03824             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03825             IsTileType(v->tile, MP_STATION) &&
03826             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03827         ProcessOrders(v);
03828       }
03829     }
03830     v->SetLastSpeed();
03831   }
03832 
03833   for (Train *u = v; u != NULL; u = u->Next()) {
03834     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03835 
03836     u->UpdateViewport(false, false);
03837   }
03838 
03839   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03840 
03841   return true;
03842 }
03843 
03848 Money Train::GetRunningCost() const
03849 {
03850   Money cost = 0;
03851   const Train *v = this;
03852 
03853   do {
03854     const Engine *e = v->GetEngine();
03855     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03856 
03857     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03858     if (cost_factor == 0) continue;
03859 
03860     /* Halve running cost for multiheaded parts */
03861     if (v->IsMultiheaded()) cost_factor /= 2;
03862 
03863     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03864   } while ((v = v->GetNextVehicle()) != NULL);
03865 
03866   return cost;
03867 }
03868 
03873 bool Train::Tick()
03874 {
03875   this->tick_counter++;
03876 
03877   if (this->IsFrontEngine()) {
03878     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03879 
03880     this->current_order_time++;
03881 
03882     if (!TrainLocoHandler(this, false)) return false;
03883 
03884     return TrainLocoHandler(this, true);
03885   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03886     /* Delete flooded standalone wagon chain */
03887     if (++this->crash_anim_pos >= 4400) {
03888       delete this;
03889       return false;
03890     }
03891   }
03892 
03893   return true;
03894 }
03895 
03900 static void CheckIfTrainNeedsService(Train *v)
03901 {
03902   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03903   if (v->IsInDepot()) {
03904     VehicleServiceInDepot(v);
03905     return;
03906   }
03907 
03908   uint max_penalty;
03909   switch (_settings_game.pf.pathfinder_for_trains) {
03910     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03911     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03912     default: NOT_REACHED();
03913   }
03914 
03915   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03916   /* Only go to the depot if it is not too far out of our way. */
03917   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03918     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03919       /* If we were already heading for a depot but it has
03920        * suddenly moved farther away, we continue our normal
03921        * schedule? */
03922       v->current_order.MakeDummy();
03923       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03924     }
03925     return;
03926   }
03927 
03928   DepotID depot = GetDepotIndex(tfdd.tile);
03929 
03930   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03931       v->current_order.GetDestination() != depot &&
03932       !Chance16(3, 16)) {
03933     return;
03934   }
03935 
03936   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03937   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03938   v->dest_tile = tfdd.tile;
03939   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03940 }
03941 
03943 void Train::OnNewDay()
03944 {
03945   AgeVehicle(this);
03946 
03947   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03948 
03949   if (this->IsFrontEngine()) {
03950     CheckVehicleBreakdown(this);
03951 
03952     CheckIfTrainNeedsService(this);
03953 
03954     CheckOrders(this);
03955 
03956     /* update destination */
03957     if (this->current_order.IsType(OT_GOTO_STATION)) {
03958       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03959       if (tile != INVALID_TILE) this->dest_tile = tile;
03960     }
03961 
03962     if (this->running_ticks != 0) {
03963       /* running costs */
03964       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03965 
03966       this->profit_this_year -= cost.GetCost();
03967       this->running_ticks = 0;
03968 
03969       SubtractMoneyFromCompanyFract(this->owner, cost);
03970 
03971       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03972       SetWindowClassesDirty(WC_TRAINS_LIST);
03973     }
03974   }
03975 }
03976 
03981 Trackdir Train::GetVehicleTrackdir() const
03982 {
03983   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03984 
03985   if (this->track == TRACK_BIT_DEPOT) {
03986     /* We'll assume the train is facing outwards */
03987     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03988   }
03989 
03990   if (this->track == TRACK_BIT_WORMHOLE) {
03991     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03992     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03993   }
03994 
03995   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03996 }