train_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "error.h"
00014 #include "articulated_vehicles.h"
00015 #include "command_func.h"
00016 #include "pathfinder/npf/npf_func.h"
00017 #include "pathfinder/yapf/yapf.hpp"
00018 #include "news_func.h"
00019 #include "company_func.h"
00020 #include "newgrf_sound.h"
00021 #include "newgrf_text.h"
00022 #include "strings_func.h"
00023 #include "viewport_func.h"
00024 #include "vehicle_func.h"
00025 #include "sound_func.h"
00026 #include "ai/ai.hpp"
00027 #include "game/game.hpp"
00028 #include "newgrf_station.h"
00029 #include "effectvehicle_func.h"
00030 #include "network/network.h"
00031 #include "spritecache.h"
00032 #include "core/random_func.hpp"
00033 #include "company_base.h"
00034 #include "newgrf.h"
00035 #include "order_backup.h"
00036 #include "zoom_func.h"
00037 
00038 #include "table/strings.h"
00039 #include "table/train_cmd.h"
00040 
00041 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00042 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00043 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00044 static TileIndex TrainApproachingCrossingTile(const Train *v);
00045 static void CheckIfTrainNeedsService(Train *v);
00046 static void CheckNextTrainTile(Train *v);
00047 
00048 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00049 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00050 
00051 
00059 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00060 {
00061   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00062 
00063   DiagDirection diagdir = DirToDiagDir(direction);
00064 
00065   /* Determine the diagonal direction in which we will exit this tile */
00066   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00067     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00068   }
00069 
00070   return diagdir;
00071 }
00072 
00073 
00079 byte FreightWagonMult(CargoID cargo)
00080 {
00081   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00082   return _settings_game.vehicle.freight_trains;
00083 }
00084 
00086 void CheckTrainsLengths()
00087 {
00088   const Train *v;
00089   bool first = true;
00090 
00091   FOR_ALL_TRAINS(v) {
00092     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00093       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00094         if (u->track != TRACK_BIT_DEPOT) {
00095           if ((w->track != TRACK_BIT_DEPOT &&
00096               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00097               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00098             SetDParam(0, v->index);
00099             SetDParam(1, v->owner);
00100             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00101 
00102             if (!_networking && first) {
00103               first = false;
00104               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00105             }
00106             /* Break so we warn only once for each train. */
00107             break;
00108           }
00109         }
00110       }
00111     }
00112   }
00113 }
00114 
00121 void Train::ConsistChanged(bool same_length)
00122 {
00123   uint16 max_speed = UINT16_MAX;
00124 
00125   assert(this->IsFrontEngine() || this->IsFreeWagon());
00126 
00127   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00128   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00129   this->gcache.cached_total_length = 0;
00130   this->compatible_railtypes = RAILTYPES_NONE;
00131 
00132   bool train_can_tilt = true;
00133 
00134   for (Train *u = this; u != NULL; u = u->Next()) {
00135     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00136 
00137     /* Check the this->first cache. */
00138     assert(u->First() == this);
00139 
00140     /* update the 'first engine' */
00141     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00142     u->railtype = rvi_u->railtype;
00143 
00144     if (u->IsEngine()) first_engine = u->engine_type;
00145 
00146     /* Set user defined data to its default value */
00147     u->tcache.user_def_data = rvi_u->user_def_data;
00148     this->InvalidateNewGRFCache();
00149     u->InvalidateNewGRFCache();
00150   }
00151 
00152   for (Train *u = this; u != NULL; u = u->Next()) {
00153     /* Update user defined data (must be done before other properties) */
00154     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00155     this->InvalidateNewGRFCache();
00156     u->InvalidateNewGRFCache();
00157   }
00158 
00159   for (Train *u = this; u != NULL; u = u->Next()) {
00160     const Engine *e_u = u->GetEngine();
00161     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00162 
00163     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00164 
00165     /* Cache wagon override sprite group. NULL is returned if there is none */
00166     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00167 
00168     /* Reset colour map */
00169     u->colourmap = PAL_NONE;
00170 
00171     /* Update powered-wagon-status and visual effect */
00172     u->UpdateVisualEffect(true);
00173 
00174     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00175         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00176       /* wagon is powered */
00177       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00178     } else {
00179       ClrBit(u->flags, VRF_POWEREDWAGON);
00180     }
00181 
00182     if (!u->IsArticulatedPart()) {
00183       /* Do not count powered wagons for the compatible railtypes, as wagons always
00184          have railtype normal */
00185       if (rvi_u->power > 0) {
00186         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00187       }
00188 
00189       /* Some electric engines can be allowed to run on normal rail. It happens to all
00190        * existing electric engines when elrails are disabled and then re-enabled */
00191       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00192         u->railtype = RAILTYPE_RAIL;
00193         u->compatible_railtypes |= RAILTYPES_RAIL;
00194       }
00195 
00196       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00197       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00198         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00199         if (speed != 0) max_speed = min(speed, max_speed);
00200       }
00201     }
00202 
00203     u->cargo_cap = e_u->DetermineCapacity(u);
00204     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00205 
00206     /* check the vehicle length (callback) */
00207     uint16 veh_len = CALLBACK_FAILED;
00208     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00209       /* Use callback 36 */
00210       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00211     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00212       /* Use callback 11 */
00213       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00214     }
00215     if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00216       ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00217     }
00218     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00219     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00220 
00221     /* verify length hasn't changed */
00222     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00223 
00224     /* update vehicle length? */
00225     if (!same_length) u->gcache.cached_veh_length = veh_len;
00226 
00227     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00228     this->InvalidateNewGRFCache();
00229     u->InvalidateNewGRFCache();
00230   }
00231 
00232   /* store consist weight/max speed in cache */
00233   this->vcache.cached_max_speed = max_speed;
00234   this->tcache.cached_tilt = train_can_tilt;
00235   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00236 
00237   /* recalculate cached weights and power too (we do this *after* the rest, so it is known which wagons are powered and need extra weight added) */
00238   this->CargoChanged();
00239 
00240   if (this->IsFrontEngine()) {
00241     this->UpdateAcceleration();
00242     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00243     InvalidateWindowData(WC_VEHICLE_REFIT, this->index);
00244   }
00245 }
00246 
00257 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00258 {
00259   const Station *st = Station::Get(station_id);
00260   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00261   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00262 
00263   /* Default to the middle of the station for stations stops that are not in
00264    * the order list like intermediate stations when non-stop is disabled */
00265   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00266   if (v->gcache.cached_total_length >= *station_length) {
00267     /* The train is longer than the station, make it stop at the far end of the platform */
00268     osl = OSL_PLATFORM_FAR_END;
00269   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00270     osl = v->current_order.GetStopLocation();
00271   }
00272 
00273   /* The stop location of the FRONT! of the train */
00274   int stop;
00275   switch (osl) {
00276     default: NOT_REACHED();
00277 
00278     case OSL_PLATFORM_NEAR_END:
00279       stop = v->gcache.cached_total_length;
00280       break;
00281 
00282     case OSL_PLATFORM_MIDDLE:
00283       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00284       break;
00285 
00286     case OSL_PLATFORM_FAR_END:
00287       stop = *station_length;
00288       break;
00289   }
00290 
00291   /* Subtract half the front vehicle length of the train so we get the real
00292    * stop location of the train. */
00293   return stop - (v->gcache.cached_veh_length + 1) / 2;
00294 }
00295 
00296 
00301 int Train::GetCurveSpeedLimit() const
00302 {
00303   assert(this->First() == this);
00304 
00305   static const int absolute_max_speed = UINT16_MAX;
00306   int max_speed = absolute_max_speed;
00307 
00308   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00309 
00310   int curvecount[2] = {0, 0};
00311 
00312   /* first find the curve speed limit */
00313   int numcurve = 0;
00314   int sum = 0;
00315   int pos = 0;
00316   int lastpos = -1;
00317   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00318     Direction this_dir = u->direction;
00319     Direction next_dir = u->Next()->direction;
00320 
00321     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00322     if (dirdiff == DIRDIFF_SAME) continue;
00323 
00324     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00325     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00326     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00327       if (lastpos != -1) {
00328         numcurve++;
00329         sum += pos - lastpos;
00330         if (pos - lastpos == 1 && max_speed > 88) {
00331           max_speed = 88;
00332         }
00333       }
00334       lastpos = pos;
00335     }
00336 
00337     /* if we have a 90 degree turn, fix the speed limit to 60 */
00338     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00339       max_speed = 61;
00340     }
00341   }
00342 
00343   if (numcurve > 0 && max_speed > 88) {
00344     if (curvecount[0] == 1 && curvecount[1] == 1) {
00345       max_speed = absolute_max_speed;
00346     } else {
00347       sum /= numcurve;
00348       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00349     }
00350   }
00351 
00352   if (max_speed != absolute_max_speed) {
00353     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00354     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00355     max_speed += (max_speed / 2) * rti->curve_speed;
00356 
00357     if (this->tcache.cached_tilt) {
00358       /* Apply max_speed bonus of 20% for a tilting train */
00359       max_speed += max_speed / 5;
00360     }
00361   }
00362 
00363   return max_speed;
00364 }
00365 
00370 int Train::GetCurrentMaxSpeed() const
00371 {
00372   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return min(this->gcache.cached_max_track_speed, this->current_order.max_speed);
00373 
00374   int max_speed = this->tcache.cached_max_curve_speed;
00375   assert(max_speed == this->GetCurveSpeedLimit());
00376 
00377   if (IsRailStationTile(this->tile)) {
00378     StationID sid = GetStationIndex(this->tile);
00379     if (this->current_order.ShouldStopAtStation(this, sid)) {
00380       int station_ahead;
00381       int station_length;
00382       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00383 
00384       /* The distance to go is whatever is still ahead of the train minus the
00385        * distance from the train's stop location to the end of the platform */
00386       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00387 
00388       if (distance_to_go > 0) {
00389         int st_max_speed = 120;
00390 
00391         int delta_v = this->cur_speed / (distance_to_go + 1);
00392         if (max_speed > (this->cur_speed - delta_v)) {
00393           st_max_speed = this->cur_speed - (delta_v / 10);
00394         }
00395 
00396         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00397         max_speed = min(max_speed, st_max_speed);
00398       }
00399     }
00400   }
00401 
00402   for (const Train *u = this; u != NULL; u = u->Next()) {
00403     if (u->track == TRACK_BIT_DEPOT) {
00404       max_speed = min(max_speed, 61);
00405       break;
00406     }
00407   }
00408 
00409   max_speed = min(max_speed, this->current_order.max_speed);
00410   return min(max_speed, this->gcache.cached_max_track_speed);
00411 }
00412 
00414 void Train::UpdateAcceleration()
00415 {
00416   assert(this->IsFrontEngine());
00417 
00418   uint power = this->gcache.cached_power;
00419   uint weight = this->gcache.cached_weight;
00420   assert(weight != 0);
00421   this->acceleration = Clamp(power / weight * 4, 1, 255);
00422 }
00423 
00429 int Train::GetDisplayImageWidth(Point *offset) const
00430 {
00431   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00432   int vehicle_pitch = 0;
00433 
00434   const Engine *e = this->GetEngine();
00435   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00436     reference_width = e->GetGRF()->traininfo_vehicle_width;
00437     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00438   }
00439 
00440   if (offset != NULL) {
00441     offset->x = reference_width / 2;
00442     offset->y = vehicle_pitch;
00443   }
00444   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00445 }
00446 
00447 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00448 {
00449   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00450 }
00451 
00458 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00459 {
00460   uint8 spritenum = this->spritenum;
00461   SpriteID sprite;
00462 
00463   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00464 
00465   if (is_custom_sprite(spritenum)) {
00466     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00467     if (sprite != 0) return sprite;
00468 
00469     spritenum = this->GetEngine()->original_image_index;
00470   }
00471 
00472   sprite = GetDefaultTrainSprite(spritenum, direction);
00473 
00474   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00475 
00476   return sprite;
00477 }
00478 
00479 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00480 {
00481   const Engine *e = Engine::Get(engine);
00482   Direction dir = rear_head ? DIR_E : DIR_W;
00483   uint8 spritenum = e->u.rail.image_index;
00484 
00485   if (is_custom_sprite(spritenum)) {
00486     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00487     if (sprite != 0) {
00488       if (e->GetGRF() != NULL) {
00489         y += e->GetGRF()->traininfo_vehicle_pitch;
00490       }
00491       return sprite;
00492     }
00493 
00494     spritenum = Engine::Get(engine)->original_image_index;
00495   }
00496 
00497   if (rear_head) spritenum++;
00498 
00499   return GetDefaultTrainSprite(spritenum, DIR_W);
00500 }
00501 
00502 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00503 {
00504   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00505     int yf = y;
00506     int yr = y;
00507 
00508     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00509     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00510     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00511     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00512 
00513     preferred_x = Clamp(preferred_x, left - UnScaleByZoom(real_spritef->x_offs, ZOOM_LVL_GUI) + 14, right - UnScaleByZoom(real_spriter->width, ZOOM_LVL_GUI) - UnScaleByZoom(real_spriter->x_offs, ZOOM_LVL_GUI) - 15);
00514 
00515     DrawSprite(spritef, pal, preferred_x - 14, yf);
00516     DrawSprite(spriter, pal, preferred_x + 15, yr);
00517   } else {
00518     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00519     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00520     preferred_x = Clamp(preferred_x, left - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI), right - UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI));
00521     DrawSprite(sprite, pal, preferred_x, y);
00522   }
00523 }
00524 
00533 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00534 {
00535   const RailVehicleInfo *rvi = &e->u.rail;
00536 
00537   /* Check that the wagon can drive on the track in question */
00538   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00539 
00540   if (flags & DC_EXEC) {
00541     Train *v = new Train();
00542     *ret = v;
00543     v->spritenum = rvi->image_index;
00544 
00545     v->engine_type = e->index;
00546     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00547 
00548     DiagDirection dir = GetRailDepotDirection(tile);
00549 
00550     v->direction = DiagDirToDir(dir);
00551     v->tile = tile;
00552 
00553     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00554     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00555 
00556     v->x_pos = x;
00557     v->y_pos = y;
00558     v->z_pos = GetSlopePixelZ(x, y);
00559     v->owner = _current_company;
00560     v->track = TRACK_BIT_DEPOT;
00561     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00562 
00563     v->SetWagon();
00564 
00565     v->SetFreeWagon();
00566     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00567 
00568     v->cargo_type = e->GetDefaultCargoType();
00569     v->cargo_cap = rvi->capacity;
00570 
00571     v->railtype = rvi->railtype;
00572 
00573     v->build_year = _cur_year;
00574     v->cur_image = SPR_IMG_QUERY;
00575     v->random_bits = VehicleRandomBits();
00576 
00577     v->group_id = DEFAULT_GROUP;
00578 
00579     AddArticulatedParts(v);
00580 
00581     _new_vehicle_id = v->index;
00582 
00583     VehicleUpdatePosition(v);
00584     v->First()->ConsistChanged(false);
00585     UpdateTrainGroupID(v->First());
00586 
00587     CheckConsistencyOfArticulatedVehicle(v);
00588 
00589     /* Try to connect the vehicle to one of free chains of wagons. */
00590     Train *w;
00591     FOR_ALL_TRAINS(w) {
00592       if (w->tile == tile &&              
00593           w->IsFreeWagon() &&             
00594           w->engine_type == e->index &&   
00595           w->First() != v &&              
00596           !(w->vehstatus & VS_CRASHED)) { 
00597         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00598         break;
00599       }
00600     }
00601   }
00602 
00603   return CommandCost();
00604 }
00605 
00607 static void NormalizeTrainVehInDepot(const Train *u)
00608 {
00609   const Train *v;
00610   FOR_ALL_TRAINS(v) {
00611     if (v->IsFreeWagon() && v->tile == u->tile &&
00612         v->track == TRACK_BIT_DEPOT) {
00613       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00614           CMD_MOVE_RAIL_VEHICLE).Failed())
00615         break;
00616     }
00617   }
00618 }
00619 
00620 static void AddRearEngineToMultiheadedTrain(Train *v)
00621 {
00622   Train *u = new Train();
00623   v->value >>= 1;
00624   u->value = v->value;
00625   u->direction = v->direction;
00626   u->owner = v->owner;
00627   u->tile = v->tile;
00628   u->x_pos = v->x_pos;
00629   u->y_pos = v->y_pos;
00630   u->z_pos = v->z_pos;
00631   u->track = TRACK_BIT_DEPOT;
00632   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00633   u->spritenum = v->spritenum + 1;
00634   u->cargo_type = v->cargo_type;
00635   u->cargo_subtype = v->cargo_subtype;
00636   u->cargo_cap = v->cargo_cap;
00637   u->railtype = v->railtype;
00638   u->engine_type = v->engine_type;
00639   u->build_year = v->build_year;
00640   u->cur_image = SPR_IMG_QUERY;
00641   u->random_bits = VehicleRandomBits();
00642   v->SetMultiheaded();
00643   u->SetMultiheaded();
00644   v->SetNext(u);
00645   VehicleUpdatePosition(u);
00646 
00647   /* Now we need to link the front and rear engines together */
00648   v->other_multiheaded_part = u;
00649   u->other_multiheaded_part = v;
00650 }
00651 
00661 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00662 {
00663   const RailVehicleInfo *rvi = &e->u.rail;
00664 
00665   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00666 
00667   /* Check if depot and new engine uses the same kind of tracks *
00668    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00669   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00670 
00671   if (flags & DC_EXEC) {
00672     DiagDirection dir = GetRailDepotDirection(tile);
00673     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00674     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00675 
00676     Train *v = new Train();
00677     *ret = v;
00678     v->direction = DiagDirToDir(dir);
00679     v->tile = tile;
00680     v->owner = _current_company;
00681     v->x_pos = x;
00682     v->y_pos = y;
00683     v->z_pos = GetSlopePixelZ(x, y);
00684     v->track = TRACK_BIT_DEPOT;
00685     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00686     v->spritenum = rvi->image_index;
00687     v->cargo_type = e->GetDefaultCargoType();
00688     v->cargo_cap = rvi->capacity;
00689     v->last_station_visited = INVALID_STATION;
00690     v->last_loading_station = INVALID_STATION;
00691 
00692     v->engine_type = e->index;
00693     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00694 
00695     v->reliability = e->reliability;
00696     v->reliability_spd_dec = e->reliability_spd_dec;
00697     v->max_age = e->GetLifeLengthInDays();
00698 
00699     v->railtype = rvi->railtype;
00700     _new_vehicle_id = v->index;
00701 
00702     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00703     v->date_of_last_service = _date;
00704     v->build_year = _cur_year;
00705     v->cur_image = SPR_IMG_QUERY;
00706     v->random_bits = VehicleRandomBits();
00707 
00708     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00709 
00710     v->group_id = DEFAULT_GROUP;
00711 
00712     v->SetFrontEngine();
00713     v->SetEngine();
00714 
00715     VehicleUpdatePosition(v);
00716 
00717     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00718       AddRearEngineToMultiheadedTrain(v);
00719     } else {
00720       AddArticulatedParts(v);
00721     }
00722 
00723     v->ConsistChanged(false);
00724     UpdateTrainGroupID(v);
00725 
00726     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00727       NormalizeTrainVehInDepot(v);
00728     }
00729 
00730     CheckConsistencyOfArticulatedVehicle(v);
00731   }
00732 
00733   return CommandCost();
00734 }
00735 
00740 bool Train::IsInDepot() const
00741 {
00742   /* Is the front engine stationary in the depot? */
00743   if (!IsRailDepotTile(this->tile) || this->cur_speed != 0) return false;
00744 
00745   /* Check whether the rest is also already trying to enter the depot. */
00746   for (const Train *v = this; v != NULL; v = v->Next()) {
00747     if (v->track != TRACK_BIT_DEPOT || v->tile != this->tile) return false;
00748   }
00749 
00750   return true;
00751 }
00752 
00757 bool Train::IsStoppedInDepot() const
00758 {
00759   /* Are we stopped? Of course wagons don't really care... */
00760   if (this->IsFrontEngine() && !(this->vehstatus & VS_STOPPED)) return false;
00761   return this->IsInDepot();
00762 }
00763 
00764 static Train *FindGoodVehiclePos(const Train *src)
00765 {
00766   EngineID eng = src->engine_type;
00767   TileIndex tile = src->tile;
00768 
00769   Train *dst;
00770   FOR_ALL_TRAINS(dst) {
00771     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00772       /* check so all vehicles in the line have the same engine. */
00773       Train *t = dst;
00774       while (t->engine_type == eng) {
00775         t = t->Next();
00776         if (t == NULL) return dst;
00777       }
00778     }
00779   }
00780 
00781   return NULL;
00782 }
00783 
00785 typedef SmallVector<Train *, 16> TrainList;
00786 
00792 static void MakeTrainBackup(TrainList &list, Train *t)
00793 {
00794   for (; t != NULL; t = t->Next()) *list.Append() = t;
00795 }
00796 
00801 static void RestoreTrainBackup(TrainList &list)
00802 {
00803   /* No train, nothing to do. */
00804   if (list.Length() == 0) return;
00805 
00806   Train *prev = NULL;
00807   /* Iterate over the list and rebuild it. */
00808   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00809     Train *t = *iter;
00810     if (prev != NULL) {
00811       prev->SetNext(t);
00812     } else if (t->Previous() != NULL) {
00813       /* Make sure the head of the train is always the first in the chain. */
00814       t->Previous()->SetNext(NULL);
00815     }
00816     prev = t;
00817   }
00818 }
00819 
00825 static void RemoveFromConsist(Train *part, bool chain = false)
00826 {
00827   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00828 
00829   /* Unlink at the front, but make it point to the next
00830    * vehicle after the to be remove part. */
00831   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00832 
00833   /* Unlink at the back */
00834   tail->SetNext(NULL);
00835 }
00836 
00842 static void InsertInConsist(Train *dst, Train *chain)
00843 {
00844   /* We do not want to add something in the middle of an articulated part. */
00845   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00846 
00847   chain->Last()->SetNext(dst->Next());
00848   dst->SetNext(chain);
00849 }
00850 
00856 static void NormaliseDualHeads(Train *t)
00857 {
00858   for (; t != NULL; t = t->GetNextVehicle()) {
00859     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00860 
00861     /* Make sure that there are no free cars before next engine */
00862     Train *u;
00863     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00864 
00865     if (u == t->other_multiheaded_part) continue;
00866 
00867     /* Remove the part from the 'wrong' train */
00868     RemoveFromConsist(t->other_multiheaded_part);
00869     /* And add it to the 'right' train */
00870     InsertInConsist(u, t->other_multiheaded_part);
00871   }
00872 }
00873 
00878 static void NormaliseSubtypes(Train *chain)
00879 {
00880   /* Nothing to do */
00881   if (chain == NULL) return;
00882 
00883   /* We must be the first in the chain. */
00884   assert(chain->Previous() == NULL);
00885 
00886   /* Set the appropriate bits for the first in the chain. */
00887   if (chain->IsWagon()) {
00888     chain->SetFreeWagon();
00889   } else {
00890     assert(chain->IsEngine());
00891     chain->SetFrontEngine();
00892   }
00893 
00894   /* Now clear the bits for the rest of the chain */
00895   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00896     t->ClearFreeWagon();
00897     t->ClearFrontEngine();
00898   }
00899 }
00900 
00910 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00911 {
00912   /* Just add 'new' engines and subtract the original ones.
00913    * If that's less than or equal to 0 we can be sure we did
00914    * not add any engines (read: trains) along the way. */
00915   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00916       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00917       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00918       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00919     return CommandCost();
00920   }
00921 
00922   /* Get a free unit number and check whether it's within the bounds.
00923    * There will always be a maximum of one new train. */
00924   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00925 
00926   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00927 }
00928 
00934 static CommandCost CheckTrainAttachment(Train *t)
00935 {
00936   /* No multi-part train, no need to check. */
00937   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00938 
00939   /* The maximum length for a train. For each part we decrease this by one
00940    * and if the result is negative the train is simply too long. */
00941   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00942 
00943   Train *head = t;
00944   Train *prev = t;
00945 
00946   /* Break the prev -> t link so it always holds within the loop. */
00947   t = t->Next();
00948   prev->SetNext(NULL);
00949 
00950   /* Make sure the cache is cleared. */
00951   head->InvalidateNewGRFCache();
00952 
00953   while (t != NULL) {
00954     allowed_len -= t->gcache.cached_veh_length;
00955 
00956     Train *next = t->Next();
00957 
00958     /* Unlink the to-be-added piece; it is already unlinked from the previous
00959      * part due to the fact that the prev -> t link is broken. */
00960     t->SetNext(NULL);
00961 
00962     /* Don't check callback for articulated or rear dual headed parts */
00963     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00964       /* Back up and clear the first_engine data to avoid using wagon override group */
00965       EngineID first_engine = t->gcache.first_engine;
00966       t->gcache.first_engine = INVALID_ENGINE;
00967 
00968       /* We don't want the cache to interfere. head's cache is cleared before
00969        * the loop and after each callback does not need to be cleared here. */
00970       t->InvalidateNewGRFCache();
00971 
00972       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00973 
00974       /* Restore original first_engine data */
00975       t->gcache.first_engine = first_engine;
00976 
00977       /* We do not want to remember any cached variables from the test run */
00978       t->InvalidateNewGRFCache();
00979       head->InvalidateNewGRFCache();
00980 
00981       if (callback != CALLBACK_FAILED) {
00982         /* A failing callback means everything is okay */
00983         StringID error = STR_NULL;
00984 
00985         if (head->GetGRF()->grf_version < 8) {
00986           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00987           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00988           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00989         } else {
00990           if (callback < 0x400) {
00991             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00992           } else {
00993             switch (callback) {
00994               case 0x400: // allow if railtypes match (always the case for OpenTTD)
00995               case 0x401: // allow
00996                 break;
00997 
00998               default:    // unknown reason -> disallow
00999               case 0x402: // disallow attaching
01000                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01001                 break;
01002             }
01003           }
01004         }
01005 
01006         if (error != STR_NULL) return_cmd_error(error);
01007       }
01008     }
01009 
01010     /* And link it to the new part. */
01011     prev->SetNext(t);
01012     prev = t;
01013     t = next;
01014   }
01015 
01016   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01017   return CommandCost();
01018 }
01019 
01030 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01031 {
01032   /* Check whether we may actually construct the trains. */
01033   CommandCost ret = CheckTrainAttachment(src);
01034   if (ret.Failed()) return ret;
01035   ret = CheckTrainAttachment(dst);
01036   if (ret.Failed()) return ret;
01037 
01038   /* Check whether we need to build a new train. */
01039   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01040 }
01041 
01050 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01051 {
01052   /* First determine the front of the two resulting trains */
01053   if (*src_head == *dst_head) {
01054     /* If we aren't moving part(s) to a new train, we are just moving the
01055      * front back and there is not destination head. */
01056     *dst_head = NULL;
01057   } else if (*dst_head == NULL) {
01058     /* If we are moving to a new train the head of the move train would become
01059      * the head of the new vehicle. */
01060     *dst_head = src;
01061   }
01062 
01063   if (src == *src_head) {
01064     /* If we are moving the front of a train then we are, in effect, creating
01065      * a new head for the train. Point to that. Unless we are moving the whole
01066      * train in which case there is not 'source' train anymore.
01067      * In case we are a multiheaded part we want the complete thing to come
01068      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01069      * that is followed by a rear multihead we do not want to include that. */
01070     *src_head = move_chain ? NULL :
01071         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01072   }
01073 
01074   /* Now it's just simply removing the part that we are going to move from the
01075    * source train and *if* the destination is a not a new train add the chain
01076    * at the destination location. */
01077   RemoveFromConsist(src, move_chain);
01078   if (*dst_head != src) InsertInConsist(dst, src);
01079 
01080   /* Now normalise the dual heads, that is move the dual heads around in such
01081    * a way that the head and rear of a dual head are in the same train */
01082   NormaliseDualHeads(*src_head);
01083   NormaliseDualHeads(*dst_head);
01084 }
01085 
01091 static void NormaliseTrainHead(Train *head)
01092 {
01093   /* Not much to do! */
01094   if (head == NULL) return;
01095 
01096   /* Tell the 'world' the train changed. */
01097   head->ConsistChanged(false);
01098   UpdateTrainGroupID(head);
01099 
01100   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01101   if (!head->IsFrontEngine()) return;
01102 
01103   /* Update the refit button and window */
01104   InvalidateWindowData(WC_VEHICLE_REFIT, head->index);
01105   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01106 
01107   /* If we don't have a unit number yet, set one. */
01108   if (head->unitnumber != 0) return;
01109   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01110 }
01111 
01124 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01125 {
01126   VehicleID s = GB(p1, 0, 20);
01127   VehicleID d = GB(p2, 0, 20);
01128   bool move_chain = HasBit(p1, 20);
01129 
01130   Train *src = Train::GetIfValid(s);
01131   if (src == NULL) return CMD_ERROR;
01132 
01133   CommandCost ret = CheckOwnership(src->owner);
01134   if (ret.Failed()) return ret;
01135 
01136   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01137   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01138 
01139   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01140   Train *dst;
01141   if (d == INVALID_VEHICLE) {
01142     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01143   } else {
01144     dst = Train::GetIfValid(d);
01145     if (dst == NULL) return CMD_ERROR;
01146 
01147     CommandCost ret = CheckOwnership(dst->owner);
01148     if (ret.Failed()) return ret;
01149 
01150     /* Do not allow appending to crashed vehicles, too */
01151     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01152   }
01153 
01154   /* if an articulated part is being handled, deal with its parent vehicle */
01155   src = src->GetFirstEnginePart();
01156   if (dst != NULL) {
01157     dst = dst->GetFirstEnginePart();
01158   }
01159 
01160   /* don't move the same vehicle.. */
01161   if (src == dst) return CommandCost();
01162 
01163   /* locate the head of the two chains */
01164   Train *src_head = src->First();
01165   Train *dst_head;
01166   if (dst != NULL) {
01167     dst_head = dst->First();
01168     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01169     /* Now deal with articulated part of destination wagon */
01170     dst = dst->GetLastEnginePart();
01171   } else {
01172     dst_head = NULL;
01173   }
01174 
01175   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01176 
01177   /* When moving all wagons, we can't have the same src_head and dst_head */
01178   if (move_chain && src_head == dst_head) return CommandCost();
01179 
01180   /* When moving a multiheaded part to be place after itself, bail out. */
01181   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01182 
01183   /* Check if all vehicles in the source train are stopped inside a depot. */
01184   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01185 
01186   /* Check if all vehicles in the destination train are stopped inside a depot. */
01187   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01188 
01189   /* First make a backup of the order of the trains. That way we can do
01190    * whatever we want with the order and later on easily revert. */
01191   TrainList original_src;
01192   TrainList original_dst;
01193 
01194   MakeTrainBackup(original_src, src_head);
01195   MakeTrainBackup(original_dst, dst_head);
01196 
01197   /* Also make backup of the original heads as ArrangeTrains can change them.
01198    * For the destination head we do not care if it is the same as the source
01199    * head because in that case it's just a copy. */
01200   Train *original_src_head = src_head;
01201   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01202 
01203   /* We want this information from before the rearrangement, but execute this after the validation. */
01204   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01205   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01206 
01207   /* (Re)arrange the trains in the wanted arrangement. */
01208   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01209 
01210   if ((flags & DC_AUTOREPLACE) == 0) {
01211     /* If the autoreplace flag is set we do not need to test for the validity
01212      * because we are going to revert the train to its original state. As we
01213      * assume the original state was correct autoreplace can skip this. */
01214     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01215     if (ret.Failed()) {
01216       /* Restore the train we had. */
01217       RestoreTrainBackup(original_src);
01218       RestoreTrainBackup(original_dst);
01219       return ret;
01220     }
01221   }
01222 
01223   /* do it? */
01224   if (flags & DC_EXEC) {
01225     /* Remove old heads from the statistics */
01226     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01227     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01228 
01229     /* First normalise the sub types of the chains. */
01230     NormaliseSubtypes(src_head);
01231     NormaliseSubtypes(dst_head);
01232 
01233     /* There are 14 different cases:
01234      *  1) front engine gets moved to a new train, it stays a front engine.
01235      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01236      *     b) the 'next' part is an engine that becomes a front engine.
01237      *     c) there is no 'next' part, nothing else happens
01238      *  2) front engine gets moved to another train, it is not a front engine anymore
01239      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01240      *     b) the 'next' part is an engine that becomes a front engine.
01241      *     c) there is no 'next' part, nothing else happens
01242      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
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      *  4) free wagon gets moved
01246      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01247      *     b) the 'next' part is an engine that becomes a front engine.
01248      *     c) there is no 'next' part, nothing else happens
01249      *  5) non front engine gets moved and becomes a new train, nothing else happens
01250      *  6) non front engine gets moved within a train / to another train, nothing hapens
01251      *  7) wagon gets moved, nothing happens
01252      */
01253     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01254       /* Cases #2 and #3: the front engine gets trashed. */
01255       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01256       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01257       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01258       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01259       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01260       SetWindowDirty(WC_COMPANY, _current_company);
01261 
01262       /* Delete orders, group stuff and the unit number as we're not the
01263        * front of any vehicle anymore. */
01264       DeleteVehicleOrders(src);
01265       RemoveVehicleFromGroup(src);
01266       src->unitnumber = 0;
01267     }
01268 
01269     /* We weren't a front engine but are becoming one. So
01270      * we should be put in the default group. */
01271     if (original_src_head != src && dst_head == src) {
01272       SetTrainGroupID(src, DEFAULT_GROUP);
01273       SetWindowDirty(WC_COMPANY, _current_company);
01274     }
01275 
01276     /* Add new heads to statistics */
01277     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01278     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01279 
01280     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01281     NormaliseTrainHead(src_head);
01282     NormaliseTrainHead(dst_head);
01283 
01284     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01285       CheckCargoCapacity(src_head);
01286       CheckCargoCapacity(dst_head);
01287     }
01288 
01289     /* We are undoubtedly changing something in the depot and train list. */
01290     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01291     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01292   } else {
01293     /* We don't want to execute what we're just tried. */
01294     RestoreTrainBackup(original_src);
01295     RestoreTrainBackup(original_dst);
01296   }
01297 
01298   return CommandCost();
01299 }
01300 
01312 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01313 {
01314   /* Check if we deleted a vehicle window */
01315   Window *w = NULL;
01316 
01317   /* Sell a chain of vehicles or not? */
01318   bool sell_chain = HasBit(data, 0);
01319 
01320   Train *v = Train::From(t)->GetFirstEnginePart();
01321   Train *first = v->First();
01322 
01323   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01324 
01325   /* First make a backup of the order of the train. That way we can do
01326    * whatever we want with the order and later on easily revert. */
01327   TrainList original;
01328   MakeTrainBackup(original, first);
01329 
01330   /* We need to keep track of the new head and the head of what we're going to sell. */
01331   Train *new_head = first;
01332   Train *sell_head = NULL;
01333 
01334   /* Split the train in the wanted way. */
01335   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01336 
01337   /* We don't need to validate the second train; it's going to be sold. */
01338   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01339   if (ret.Failed()) {
01340     /* Restore the train we had. */
01341     RestoreTrainBackup(original);
01342     return ret;
01343   }
01344 
01345   CommandCost cost(EXPENSES_NEW_VEHICLES);
01346   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01347 
01348   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01349     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01350   }
01351 
01352   /* do it? */
01353   if (flags & DC_EXEC) {
01354     /* First normalise the sub types of the chain. */
01355     NormaliseSubtypes(new_head);
01356 
01357     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01358       /* We are selling the front engine. In this case we want to
01359        * 'give' the order, unit number and such to the new head. */
01360       new_head->orders.list = first->orders.list;
01361       new_head->AddToShared(first);
01362       DeleteVehicleOrders(first);
01363 
01364       /* Copy other important data from the front engine */
01365       new_head->CopyVehicleConfigAndStatistics(first);
01366       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01367 
01368       /* If we deleted a window then open a new one for the 'new' train */
01369       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01370     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01371       OrderBackup::Backup(v, user);
01372     }
01373 
01374     /* We need to update the information about the train. */
01375     NormaliseTrainHead(new_head);
01376 
01377     /* We are undoubtedly changing something in the depot and train list. */
01378     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01379     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01380 
01381     /* Actually delete the sold 'goods' */
01382     delete sell_head;
01383   } else {
01384     /* We don't want to execute what we're just tried. */
01385     RestoreTrainBackup(original);
01386   }
01387 
01388   return cost;
01389 }
01390 
01391 void Train::UpdateDeltaXY(Direction direction)
01392 {
01393   /* Set common defaults. */
01394   this->x_offs    = -1;
01395   this->y_offs    = -1;
01396   this->x_extent  =  3;
01397   this->y_extent  =  3;
01398   this->z_extent  =  6;
01399   this->x_bb_offs =  0;
01400   this->y_bb_offs =  0;
01401 
01402   if (!IsDiagonalDirection(direction)) {
01403     static const int _sign_table[] =
01404     {
01405       // x, y
01406       -1, -1, // DIR_N
01407       -1,  1, // DIR_E
01408        1,  1, // DIR_S
01409        1, -1, // DIR_W
01410     };
01411 
01412     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01413 
01414     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01415     this->x_offs -= half_shorten * _sign_table[direction];
01416     this->y_offs -= half_shorten * _sign_table[direction + 1];
01417     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01418     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01419   } else {
01420     switch (direction) {
01421         /* Shorten southern corner of the bounding box according the vehicle length
01422          * and center the bounding box on the vehicle. */
01423       case DIR_NE:
01424         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01425         this->x_extent  = this->gcache.cached_veh_length - 1;
01426         this->x_bb_offs = -1;
01427         break;
01428 
01429       case DIR_NW:
01430         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01431         this->y_extent  = this->gcache.cached_veh_length - 1;
01432         this->y_bb_offs = -1;
01433         break;
01434 
01435         /* Move northern corner of the bounding box down according to vehicle length
01436          * and center the bounding box on the vehicle. */
01437       case DIR_SW:
01438         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01439         this->x_extent  = VEHICLE_LENGTH - 1;
01440         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01441         break;
01442 
01443       case DIR_SE:
01444         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01445         this->y_extent  = VEHICLE_LENGTH - 1;
01446         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01447         break;
01448 
01449       default:
01450         NOT_REACHED();
01451     }
01452   }
01453 }
01454 
01459 static void MarkTrainAsStuck(Train *v)
01460 {
01461   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01462     /* It is the first time the problem occurred, set the "train stuck" flag. */
01463     SetBit(v->flags, VRF_TRAIN_STUCK);
01464 
01465     v->wait_counter = 0;
01466 
01467     /* Stop train */
01468     v->cur_speed = 0;
01469     v->subspeed = 0;
01470     v->SetLastSpeed();
01471 
01472     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01473   }
01474 }
01475 
01483 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01484 {
01485   uint16 flag1 = *swap_flag1;
01486   uint16 flag2 = *swap_flag2;
01487 
01488   /* Clear the flags */
01489   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01490   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01491   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01492   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01493 
01494   /* Reverse the rail-flags (if needed) */
01495   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01496     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01497   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01498     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01499   }
01500   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01501     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01502   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01503     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01504   }
01505 }
01506 
01511 static void UpdateStatusAfterSwap(Train *v)
01512 {
01513   /* Reverse the direction. */
01514   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01515 
01516   /* Call the proper EnterTile function unless we are in a wormhole. */
01517   if (v->track != TRACK_BIT_WORMHOLE) {
01518     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01519   } else {
01520     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01521      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01522      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01523      * when we shouldn't have. Check if this is the case. */
01524     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01525     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01526       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01527       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01528         /* We have just left the wormhole, possibly set the
01529          * "goingdown" bit. UpdateInclination() can be used
01530          * because we are at the border of the tile. */
01531         VehicleUpdatePosition(v);
01532         v->UpdateInclination(true, true);
01533         return;
01534       }
01535     }
01536   }
01537 
01538   VehicleUpdatePosition(v);
01539   v->UpdateViewport(true, true);
01540 }
01541 
01548 void ReverseTrainSwapVeh(Train *v, int l, int r)
01549 {
01550   Train *a, *b;
01551 
01552   /* locate vehicles to swap */
01553   for (a = v; l != 0; l--) a = a->Next();
01554   for (b = v; r != 0; r--) b = b->Next();
01555 
01556   if (a != b) {
01557     /* swap the hidden bits */
01558     {
01559       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01560       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01561       a->vehstatus = tmp;
01562     }
01563 
01564     Swap(a->track, b->track);
01565     Swap(a->direction, b->direction);
01566     Swap(a->x_pos, b->x_pos);
01567     Swap(a->y_pos, b->y_pos);
01568     Swap(a->tile,  b->tile);
01569     Swap(a->z_pos, b->z_pos);
01570 
01571     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01572 
01573     UpdateStatusAfterSwap(a);
01574     UpdateStatusAfterSwap(b);
01575   } else {
01576     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01577      * This is a little bit redundant way, a->gv_flags will
01578      * be (re)set twice, but it reduces code duplication */
01579     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01580     UpdateStatusAfterSwap(a);
01581   }
01582 }
01583 
01584 
01590 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01591 {
01592   return (v->type == VEH_TRAIN) ? v : NULL;
01593 }
01594 
01595 
01602 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01603 {
01604   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01605 
01606   Train *t = Train::From(v);
01607   if (!t->IsFrontEngine()) return NULL;
01608 
01609   TileIndex tile = *(TileIndex *)data;
01610 
01611   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01612 
01613   return t;
01614 }
01615 
01616 
01623 static bool TrainApproachingCrossing(TileIndex tile)
01624 {
01625   assert(IsLevelCrossingTile(tile));
01626 
01627   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01628   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01629 
01630   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01631 
01632   dir = ReverseDiagDir(dir);
01633   tile_from = tile + TileOffsByDiagDir(dir);
01634 
01635   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01636 }
01637 
01638 
01645 void UpdateLevelCrossing(TileIndex tile, bool sound)
01646 {
01647   assert(IsLevelCrossingTile(tile));
01648 
01649   /* train on crossing || train approaching crossing || reserved */
01650   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01651 
01652   if (new_state != IsCrossingBarred(tile)) {
01653     if (new_state && sound) {
01654       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01655     }
01656     SetCrossingBarred(tile, new_state);
01657     MarkTileDirtyByTile(tile);
01658   }
01659 }
01660 
01661 
01667 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01668 {
01669   if (!IsCrossingBarred(tile)) {
01670     BarCrossing(tile);
01671     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01672     MarkTileDirtyByTile(tile);
01673   }
01674 }
01675 
01676 
01682 static void AdvanceWagonsBeforeSwap(Train *v)
01683 {
01684   Train *base = v;
01685   Train *first = base; // first vehicle to move
01686   Train *last = v->Last(); // last vehicle to move
01687   uint length = CountVehiclesInChain(v);
01688 
01689   while (length > 2) {
01690     last = last->Previous();
01691     first = first->Next();
01692 
01693     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01694 
01695     /* do not update images now
01696      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01697     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01698 
01699     base = first; // == base->Next()
01700     length -= 2;
01701   }
01702 }
01703 
01704 
01710 static void AdvanceWagonsAfterSwap(Train *v)
01711 {
01712   /* first of all, fix the situation when the train was entering a depot */
01713   Train *dep = v; // last vehicle in front of just left depot
01714   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01715     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01716   }
01717 
01718   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01719 
01720   if (leave != NULL) {
01721     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01722     int d = TicksToLeaveDepot(dep);
01723 
01724     if (d <= 0) {
01725       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01726       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01727       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01728     }
01729   } else {
01730     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01731   }
01732 
01733   Train *base = v;
01734   Train *first = base; // first vehicle to move
01735   Train *last = v->Last(); // last vehicle to move
01736   uint length = CountVehiclesInChain(v);
01737 
01738   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01739    * they have already correct spacing, so we have to make sure they are moved how they should */
01740   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01741 
01742   while (length > 2) {
01743     /* we reached vehicle (originally) in front of a depot, stop now
01744      * (we would move wagons that are already moved with new wagon length). */
01745     if (base == dep) break;
01746 
01747     /* the last wagon was that one leaving a depot, so do not move it anymore */
01748     if (last == dep) nomove = true;
01749 
01750     last = last->Previous();
01751     first = first->Next();
01752 
01753     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01754 
01755     /* do not update images now */
01756     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01757 
01758     base = first; // == base->Next()
01759     length -= 2;
01760   }
01761 }
01762 
01767 void ReverseTrainDirection(Train *v)
01768 {
01769   if (IsRailDepotTile(v->tile)) {
01770     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01771   }
01772 
01773   /* Clear path reservation in front if train is not stuck. */
01774   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01775 
01776   /* Check if we were approaching a rail/road-crossing */
01777   TileIndex crossing = TrainApproachingCrossingTile(v);
01778 
01779   /* count number of vehicles */
01780   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01781 
01782   AdvanceWagonsBeforeSwap(v);
01783 
01784   /* swap start<>end, start+1<>end-1, ... */
01785   int l = 0;
01786   do {
01787     ReverseTrainSwapVeh(v, l++, r--);
01788   } while (l <= r);
01789 
01790   AdvanceWagonsAfterSwap(v);
01791 
01792   if (IsRailDepotTile(v->tile)) {
01793     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01794   }
01795 
01796   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01797 
01798   ClrBit(v->flags, VRF_REVERSING);
01799 
01800   /* recalculate cached data */
01801   v->ConsistChanged(true);
01802 
01803   /* update all images */
01804   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01805 
01806   /* update crossing we were approaching */
01807   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01808 
01809   /* maybe we are approaching crossing now, after reversal */
01810   crossing = TrainApproachingCrossingTile(v);
01811   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01812 
01813   /* If we are inside a depot after reversing, don't bother with path reserving. */
01814   if (v->track == TRACK_BIT_DEPOT) {
01815     /* Can't be stuck here as inside a depot is always a safe tile. */
01816     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01817     ClrBit(v->flags, VRF_TRAIN_STUCK);
01818     return;
01819   }
01820 
01821   /* TrainExitDir does not always produce the desired dir for depots and
01822    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01823   DiagDirection dir = TrainExitDir(v->direction, v->track);
01824   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01825 
01826   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01827     /* If we are currently on a tile with conventional signals, we can't treat the
01828      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01829     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01830       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01831       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01832 
01833     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01834     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01835 
01836     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01837     if (TryPathReserve(v, false, first_tile_okay)) {
01838       /* Do a look-ahead now in case our current tile was already a safe tile. */
01839       CheckNextTrainTile(v);
01840     } else if (v->current_order.GetType() != OT_LOADING) {
01841       /* Do not wait for a way out when we're still loading */
01842       MarkTrainAsStuck(v);
01843     }
01844   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01845     /* A train not inside a PBS block can't be stuck. */
01846     ClrBit(v->flags, VRF_TRAIN_STUCK);
01847     v->wait_counter = 0;
01848   }
01849 }
01850 
01860 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01861 {
01862   Train *v = Train::GetIfValid(p1);
01863   if (v == NULL) return CMD_ERROR;
01864 
01865   CommandCost ret = CheckOwnership(v->owner);
01866   if (ret.Failed()) return ret;
01867 
01868   if (p2 != 0) {
01869     /* turn a single unit around */
01870 
01871     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01872       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01873     }
01874     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01875 
01876     Train *front = v->First();
01877     /* make sure the vehicle is stopped in the depot */
01878     if (!front->IsStoppedInDepot()) {
01879       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01880     }
01881 
01882     if (flags & DC_EXEC) {
01883       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01884 
01885       front->ConsistChanged(false);
01886       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01887       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01888       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01889       SetWindowClassesDirty(WC_TRAINS_LIST);
01890     }
01891   } else {
01892     /* turn the whole train around */
01893     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01894 
01895     if (flags & DC_EXEC) {
01896       /* Properly leave the station if we are loading and won't be loading anymore */
01897       if (v->current_order.IsType(OT_LOADING)) {
01898         const Vehicle *last = v;
01899         while (last->Next() != NULL) last = last->Next();
01900 
01901         /* not a station || different station --> leave the station */
01902         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01903           v->LeaveStation();
01904         }
01905       }
01906 
01907       /* We cancel any 'skip signal at dangers' here */
01908       v->force_proceed = TFP_NONE;
01909       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01910 
01911       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01912         ToggleBit(v->flags, VRF_REVERSING);
01913       } else {
01914         v->cur_speed = 0;
01915         v->SetLastSpeed();
01916         HideFillingPercent(&v->fill_percent_te_id);
01917         ReverseTrainDirection(v);
01918       }
01919     }
01920   }
01921   return CommandCost();
01922 }
01923 
01933 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01934 {
01935   Train *t = Train::GetIfValid(p1);
01936   if (t == NULL) return CMD_ERROR;
01937 
01938   CommandCost ret = CheckOwnership(t->owner);
01939   if (ret.Failed()) return ret;
01940 
01941 
01942   if (flags & DC_EXEC) {
01943     /* If we are forced to proceed, cancel that order.
01944      * If we are marked stuck we would want to force the train
01945      * to proceed to the next signal. In the other cases we
01946      * would like to pass the signal at danger and run till the
01947      * next signal we encounter. */
01948     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsInDepot() ? TFP_STUCK : TFP_SIGNAL;
01949     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01950   }
01951 
01952   return CommandCost();
01953 }
01954 
01962 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01963 {
01964   assert(!(v->vehstatus & VS_CRASHED));
01965 
01966   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01967 
01968   PBSTileInfo origin = FollowTrainReservation(v);
01969   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01970 
01971   switch (_settings_game.pf.pathfinder_for_trains) {
01972     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01973     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01974 
01975     default: NOT_REACHED();
01976   }
01977 }
01978 
01986 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01987 {
01988   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
01989   if (tfdd.best_length == UINT_MAX) return false;
01990 
01991   if (location    != NULL) *location    = tfdd.tile;
01992   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
01993   if (reverse     != NULL) *reverse     = tfdd.reverse;
01994 
01995   return true;
01996 }
01997 
01999 void Train::PlayLeaveStationSound() const
02000 {
02001   static const SoundFx sfx[] = {
02002     SND_04_TRAIN,
02003     SND_0A_TRAIN_HORN,
02004     SND_0A_TRAIN_HORN,
02005     SND_47_MAGLEV_2,
02006     SND_41_MAGLEV
02007   };
02008 
02009   if (PlayVehicleSound(this, VSE_START)) return;
02010 
02011   EngineID engtype = this->engine_type;
02012   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02013 }
02014 
02019 static void CheckNextTrainTile(Train *v)
02020 {
02021   /* Don't do any look-ahead if path_backoff_interval is 255. */
02022   if (_settings_game.pf.path_backoff_interval == 255) return;
02023 
02024   /* Exit if we are inside a depot. */
02025   if (v->track == TRACK_BIT_DEPOT) return;
02026 
02027   switch (v->current_order.GetType()) {
02028     /* Exit if we reached our destination depot. */
02029     case OT_GOTO_DEPOT:
02030       if (v->tile == v->dest_tile) return;
02031       break;
02032 
02033     case OT_GOTO_WAYPOINT:
02034       /* If we reached our waypoint, make sure we see that. */
02035       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02036       break;
02037 
02038     case OT_NOTHING:
02039     case OT_LEAVESTATION:
02040     case OT_LOADING:
02041       /* Exit if the current order doesn't have a destination, but the train has orders. */
02042       if (v->GetNumOrders() > 0) return;
02043       break;
02044 
02045     default:
02046       break;
02047   }
02048   /* Exit if we are on a station tile and are going to stop. */
02049   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02050 
02051   Trackdir td = v->GetVehicleTrackdir();
02052 
02053   /* On a tile with a red non-pbs signal, don't look ahead. */
02054   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02055       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02056       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02057 
02058   CFollowTrackRail ft(v);
02059   if (!ft.Follow(v->tile, td)) return;
02060 
02061   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02062     /* Next tile is not reserved. */
02063     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02064       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02065         /* If the next tile is a PBS signal, try to make a reservation. */
02066         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02067         if (_settings_game.pf.forbid_90_deg) {
02068           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02069         }
02070         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02071       }
02072     }
02073   }
02074 }
02075 
02081 static bool CheckTrainStayInDepot(Train *v)
02082 {
02083   /* bail out if not all wagons are in the same depot or not in a depot at all */
02084   for (const Train *u = v; u != NULL; u = u->Next()) {
02085     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02086   }
02087 
02088   /* if the train got no power, then keep it in the depot */
02089   if (v->gcache.cached_power == 0) {
02090     v->vehstatus |= VS_STOPPED;
02091     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02092     return true;
02093   }
02094 
02095   SigSegState seg_state;
02096 
02097   if (v->force_proceed == TFP_NONE) {
02098     /* force proceed was not pressed */
02099     if (++v->wait_counter < 37) {
02100       SetWindowClassesDirty(WC_TRAINS_LIST);
02101       return true;
02102     }
02103 
02104     v->wait_counter = 0;
02105 
02106     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02107     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02108       /* Full and no PBS signal in block or depot reserved, can't exit. */
02109       SetWindowClassesDirty(WC_TRAINS_LIST);
02110       return true;
02111     }
02112   } else {
02113     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02114   }
02115 
02116   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02117   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02118     /* We need to have a reservation for this to work. */
02119     if (HasDepotReservation(v->tile)) return true;
02120     SetDepotReservation(v->tile, true);
02121     VehicleEnterDepot(v);
02122     return true;
02123   }
02124 
02125   /* Only leave when we can reserve a path to our destination. */
02126   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02127     /* No path and no force proceed. */
02128     SetWindowClassesDirty(WC_TRAINS_LIST);
02129     MarkTrainAsStuck(v);
02130     return true;
02131   }
02132 
02133   SetDepotReservation(v->tile, true);
02134   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02135 
02136   VehicleServiceInDepot(v);
02137   SetWindowClassesDirty(WC_TRAINS_LIST);
02138   v->PlayLeaveStationSound();
02139 
02140   v->track = TRACK_BIT_X;
02141   if (v->direction & 2) v->track = TRACK_BIT_Y;
02142 
02143   v->vehstatus &= ~VS_HIDDEN;
02144   v->cur_speed = 0;
02145 
02146   v->UpdateViewport(true, true);
02147   VehicleUpdatePosition(v);
02148   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02149   v->UpdateAcceleration();
02150   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02151 
02152   return false;
02153 }
02154 
02161 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02162 {
02163   DiagDirection dir = TrackdirToExitdir(track_dir);
02164 
02165   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02166     /* Are we just leaving a tunnel/bridge? */
02167     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02168       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02169 
02170       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02171         /* Free the reservation only if no other train is on the tiles. */
02172         SetTunnelBridgeReservation(tile, false);
02173         SetTunnelBridgeReservation(end, false);
02174 
02175         if (_settings_client.gui.show_track_reservation) {
02176           MarkTileDirtyByTile(tile);
02177           MarkTileDirtyByTile(end);
02178         }
02179       }
02180     }
02181   } else if (IsRailStationTile(tile)) {
02182     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02183     /* If the new tile is not a further tile of the same station, we
02184      * clear the reservation for the whole platform. */
02185     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02186       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02187     }
02188   } else {
02189     /* Any other tile */
02190     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02191   }
02192 }
02193 
02200 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02201 {
02202   assert(v->IsFrontEngine());
02203 
02204   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02205   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02206   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02207   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02208 
02209   /* Can't be holding a reservation if we enter a depot. */
02210   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02211   if (v->track == TRACK_BIT_DEPOT) {
02212     /* Front engine is in a depot. We enter if some part is not in the depot. */
02213     for (const Train *u = v; u != NULL; u = u->Next()) {
02214       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02215     }
02216   }
02217   /* Don't free reservation if it's not ours. */
02218   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02219 
02220   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02221   while (ft.Follow(tile, td)) {
02222     tile = ft.m_new_tile;
02223     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02224     td = RemoveFirstTrackdir(&bits);
02225     assert(bits == TRACKDIR_BIT_NONE);
02226 
02227     if (!IsValidTrackdir(td)) break;
02228 
02229     if (IsTileType(tile, MP_RAILWAY)) {
02230       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02231         /* Conventional signal along trackdir: remove reservation and stop. */
02232         UnreserveRailTrack(tile, TrackdirToTrack(td));
02233         break;
02234       }
02235       if (HasPbsSignalOnTrackdir(tile, td)) {
02236         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02237           /* Red PBS signal? Can't be our reservation, would be green then. */
02238           break;
02239         } else {
02240           /* Turn the signal back to red. */
02241           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02242           MarkTileDirtyByTile(tile);
02243         }
02244       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02245         break;
02246       }
02247     }
02248 
02249     /* Don't free first station/bridge/tunnel if we are on it. */
02250     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);
02251 
02252     free_tile = true;
02253   }
02254 }
02255 
02256 static const byte _initial_tile_subcoord[6][4][3] = {
02257 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02258 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02259 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02260 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02261 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02262 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02263 };
02264 
02277 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02278 {
02279   switch (_settings_game.pf.pathfinder_for_trains) {
02280     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02281     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02282 
02283     default: NOT_REACHED();
02284   }
02285 }
02286 
02292 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02293 {
02294   PBSTileInfo origin = FollowTrainReservation(v);
02295 
02296   CFollowTrackRail ft(v);
02297 
02298   TileIndex tile = origin.tile;
02299   Trackdir  cur_td = origin.trackdir;
02300   while (ft.Follow(tile, cur_td)) {
02301     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02302       /* Possible signal tile. */
02303       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02304     }
02305 
02306     if (_settings_game.pf.forbid_90_deg) {
02307       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02308       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02309     }
02310 
02311     /* Station, depot or waypoint are a possible target. */
02312     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02313     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02314       /* Choice found or possible target encountered.
02315        * On finding a possible target, we need to stop and let the pathfinder handle the
02316        * remaining path. This is because we don't know if this target is in one of our
02317        * orders, so we might cause pathfinding to fail later on if we find a choice.
02318        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02319        * a wrong path not leading to our next destination. */
02320       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02321 
02322       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02323        * actually starts its search at the first unreserved tile. */
02324       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02325 
02326       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02327       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02328       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02329       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02330     }
02331 
02332     tile = ft.m_new_tile;
02333     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02334 
02335     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02336       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02337       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02338       /* Safe position is all good, path valid and okay. */
02339       return PBSTileInfo(tile, cur_td, true);
02340     }
02341 
02342     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02343   }
02344 
02345   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02346     /* End of line, path valid and okay. */
02347     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02348   }
02349 
02350   /* Sorry, can't reserve path, back out. */
02351   tile = origin.tile;
02352   cur_td = origin.trackdir;
02353   TileIndex stopped = ft.m_old_tile;
02354   Trackdir  stopped_td = ft.m_old_td;
02355   while (tile != stopped || cur_td != stopped_td) {
02356     if (!ft.Follow(tile, cur_td)) break;
02357 
02358     if (_settings_game.pf.forbid_90_deg) {
02359       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02360       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02361     }
02362     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02363 
02364     tile = ft.m_new_tile;
02365     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02366 
02367     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02368   }
02369 
02370   /* Path invalid. */
02371   return PBSTileInfo();
02372 }
02373 
02384 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02385 {
02386   switch (_settings_game.pf.pathfinder_for_trains) {
02387     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02388     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02389 
02390     default: NOT_REACHED();
02391   }
02392 }
02393 
02395 class VehicleOrderSaver {
02396 private:
02397   Train          *v;
02398   Order          old_order;
02399   TileIndex      old_dest_tile;
02400   StationID      old_last_station_visited;
02401   VehicleOrderID index;
02402   bool           suppress_implicit_orders;
02403 
02404 public:
02405   VehicleOrderSaver(Train *_v) :
02406     v(_v),
02407     old_order(_v->current_order),
02408     old_dest_tile(_v->dest_tile),
02409     old_last_station_visited(_v->last_station_visited),
02410     index(_v->cur_real_order_index),
02411     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02412   {
02413   }
02414 
02415   ~VehicleOrderSaver()
02416   {
02417     this->v->current_order = this->old_order;
02418     this->v->dest_tile = this->old_dest_tile;
02419     this->v->last_station_visited = this->old_last_station_visited;
02420     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02421   }
02422 
02428   bool SwitchToNextOrder(bool skip_first)
02429   {
02430     if (this->v->GetNumOrders() == 0) return false;
02431 
02432     if (skip_first) ++this->index;
02433 
02434     int depth = 0;
02435 
02436     do {
02437       /* Wrap around. */
02438       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02439 
02440       Order *order = this->v->GetOrder(this->index);
02441       assert(order != NULL);
02442 
02443       switch (order->GetType()) {
02444         case OT_GOTO_DEPOT:
02445           /* Skip service in depot orders when the train doesn't need service. */
02446           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02447         case OT_GOTO_STATION:
02448         case OT_GOTO_WAYPOINT:
02449           this->v->current_order = *order;
02450           return UpdateOrderDest(this->v, order, 0, true);
02451         case OT_CONDITIONAL: {
02452           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02453           if (next != INVALID_VEH_ORDER_ID) {
02454             depth++;
02455             this->index = next;
02456             /* Don't increment next, so no break here. */
02457             continue;
02458           }
02459           break;
02460         }
02461         default:
02462           break;
02463       }
02464       /* Don't increment inside the while because otherwise conditional
02465        * orders can lead to an infinite loop. */
02466       ++this->index;
02467       depth++;
02468     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02469 
02470     return false;
02471   }
02472 };
02473 
02474 /* choose a track */
02475 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02476 {
02477   Track best_track = INVALID_TRACK;
02478   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02479   bool changed_signal = false;
02480 
02481   assert((tracks & ~TRACK_BIT_MASK) == 0);
02482 
02483   if (got_reservation != NULL) *got_reservation = false;
02484 
02485   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02486   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02487   /* Do we have a suitable reserved track? */
02488   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02489 
02490   /* Quick return in case only one possible track is available */
02491   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02492     Track track = FindFirstTrack(tracks);
02493     /* We need to check for signals only here, as a junction tile can't have signals. */
02494     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02495       do_track_reservation = true;
02496       changed_signal = true;
02497       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02498     } else if (!do_track_reservation) {
02499       return track;
02500     }
02501     best_track = track;
02502   }
02503 
02504   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02505   DiagDirection dest_enterdir = enterdir;
02506   if (do_track_reservation) {
02507     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02508     if (res_dest.tile == INVALID_TILE) {
02509       /* Reservation failed? */
02510       if (mark_stuck) MarkTrainAsStuck(v);
02511       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02512       return FindFirstTrack(tracks);
02513     }
02514     if (res_dest.okay) {
02515       /* Got a valid reservation that ends at a safe target, quick exit. */
02516       if (got_reservation != NULL) *got_reservation = true;
02517       if (changed_signal) MarkTileDirtyByTile(tile);
02518       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02519       return best_track;
02520     }
02521 
02522     /* Check if the train needs service here, so it has a chance to always find a depot.
02523      * Also check if the current order is a service order so we don't reserve a path to
02524      * the destination but instead to the next one if service isn't needed. */
02525     CheckIfTrainNeedsService(v);
02526     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02527   }
02528 
02529   /* Save the current train order. The destructor will restore the old order on function exit. */
02530   VehicleOrderSaver orders(v);
02531 
02532   /* If the current tile is the destination of the current order and
02533    * a reservation was requested, advance to the next order.
02534    * Don't advance on a depot order as depots are always safe end points
02535    * for a path and no look-ahead is necessary. This also avoids a
02536    * problem with depot orders not part of the order list when the
02537    * order list itself is empty. */
02538   if (v->current_order.IsType(OT_LEAVESTATION)) {
02539     orders.SwitchToNextOrder(false);
02540   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02541       v->current_order.IsType(OT_GOTO_STATION) ?
02542       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02543       v->tile == v->dest_tile))) {
02544     orders.SwitchToNextOrder(true);
02545   }
02546 
02547   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02548     /* Pathfinders are able to tell that route was only 'guessed'. */
02549     bool      path_found = true;
02550     TileIndex new_tile = res_dest.tile;
02551 
02552     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02553     if (new_tile == tile) best_track = next_track;
02554     v->HandlePathfindingResult(path_found);
02555   }
02556 
02557   /* No track reservation requested -> finished. */
02558   if (!do_track_reservation) return best_track;
02559 
02560   /* A path was found, but could not be reserved. */
02561   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02562     if (mark_stuck) MarkTrainAsStuck(v);
02563     FreeTrainTrackReservation(v);
02564     return best_track;
02565   }
02566 
02567   /* No possible reservation target found, we are probably lost. */
02568   if (res_dest.tile == INVALID_TILE) {
02569     /* Try to find any safe destination. */
02570     PBSTileInfo origin = FollowTrainReservation(v);
02571     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02572       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02573       best_track = FindFirstTrack(res);
02574       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02575       if (got_reservation != NULL) *got_reservation = true;
02576       if (changed_signal) MarkTileDirtyByTile(tile);
02577     } else {
02578       FreeTrainTrackReservation(v);
02579       if (mark_stuck) MarkTrainAsStuck(v);
02580     }
02581     return best_track;
02582   }
02583 
02584   if (got_reservation != NULL) *got_reservation = true;
02585 
02586   /* Reservation target found and free, check if it is safe. */
02587   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02588     /* Extend reservation until we have found a safe position. */
02589     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02590     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02591     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02592     if (_settings_game.pf.forbid_90_deg) {
02593       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02594     }
02595 
02596     /* Get next order with destination. */
02597     if (orders.SwitchToNextOrder(true)) {
02598       PBSTileInfo cur_dest;
02599       bool path_found;
02600       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02601       if (cur_dest.tile != INVALID_TILE) {
02602         res_dest = cur_dest;
02603         if (res_dest.okay) continue;
02604         /* Path found, but could not be reserved. */
02605         FreeTrainTrackReservation(v);
02606         if (mark_stuck) MarkTrainAsStuck(v);
02607         if (got_reservation != NULL) *got_reservation = false;
02608         changed_signal = false;
02609         break;
02610       }
02611     }
02612     /* No order or no safe position found, try any position. */
02613     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02614       FreeTrainTrackReservation(v);
02615       if (mark_stuck) MarkTrainAsStuck(v);
02616       if (got_reservation != NULL) *got_reservation = false;
02617       changed_signal = false;
02618     }
02619     break;
02620   }
02621 
02622   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02623 
02624   if (changed_signal) MarkTileDirtyByTile(tile);
02625 
02626   return best_track;
02627 }
02628 
02637 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02638 {
02639   assert(v->IsFrontEngine());
02640 
02641   /* We have to handle depots specially as the track follower won't look
02642    * at the depot tile itself but starts from the next tile. If we are still
02643    * inside the depot, a depot reservation can never be ours. */
02644   if (v->track == TRACK_BIT_DEPOT) {
02645     if (HasDepotReservation(v->tile)) {
02646       if (mark_as_stuck) MarkTrainAsStuck(v);
02647       return false;
02648     } else {
02649       /* Depot not reserved, but the next tile might be. */
02650       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02651       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02652     }
02653   }
02654 
02655   Vehicle *other_train = NULL;
02656   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02657   /* The path we are driving on is already blocked by some other train.
02658    * This can only happen in certain situations when mixing path and
02659    * block signals or when changing tracks and/or signals.
02660    * Exit here as doing any further reservations will probably just
02661    * make matters worse. */
02662   if (other_train != NULL && other_train->index != v->index) {
02663     if (mark_as_stuck) MarkTrainAsStuck(v);
02664     return false;
02665   }
02666   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02667   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02668     /* Can't be stuck then. */
02669     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02670     ClrBit(v->flags, VRF_TRAIN_STUCK);
02671     return true;
02672   }
02673 
02674   /* If we are in a depot, tentatively reserve the depot. */
02675   if (v->track == TRACK_BIT_DEPOT) {
02676     SetDepotReservation(v->tile, true);
02677     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02678   }
02679 
02680   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02681   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02682   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02683 
02684   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02685 
02686   bool res_made = false;
02687   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02688 
02689   if (!res_made) {
02690     /* Free the depot reservation as well. */
02691     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02692     return false;
02693   }
02694 
02695   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02696     v->wait_counter = 0;
02697     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02698   }
02699   ClrBit(v->flags, VRF_TRAIN_STUCK);
02700   return true;
02701 }
02702 
02703 
02704 static bool CheckReverseTrain(const Train *v)
02705 {
02706   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02707       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02708       !(v->direction & 1)) {
02709     return false;
02710   }
02711 
02712   assert(v->track != TRACK_BIT_NONE);
02713 
02714   switch (_settings_game.pf.pathfinder_for_trains) {
02715     case VPF_NPF: return NPFTrainCheckReverse(v);
02716     case VPF_YAPF: return YapfTrainCheckReverse(v);
02717 
02718     default: NOT_REACHED();
02719   }
02720 }
02721 
02727 TileIndex Train::GetOrderStationLocation(StationID station)
02728 {
02729   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02730 
02731   const Station *st = Station::Get(station);
02732   if (!(st->facilities & FACIL_TRAIN)) {
02733     /* The destination station has no trainstation tiles. */
02734     this->IncrementRealOrderIndex();
02735     return 0;
02736   }
02737 
02738   return st->xy;
02739 }
02740 
02742 void Train::MarkDirty()
02743 {
02744   Train *v = this;
02745   do {
02746     v->UpdateViewport(false, false);
02747   } while ((v = v->Next()) != NULL);
02748 
02749   /* need to update acceleration and cached values since the goods on the train changed. */
02750   this->CargoChanged();
02751   this->UpdateAcceleration();
02752 }
02753 
02761 int Train::UpdateSpeed()
02762 {
02763   switch (_settings_game.vehicle.train_acceleration_model) {
02764     default: NOT_REACHED();
02765     case AM_ORIGINAL:
02766       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, min(this->gcache.cached_max_track_speed, this->current_order.max_speed));
02767 
02768     case AM_REALISTIC:
02769       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02770   }
02771 }
02772 
02778 static void TrainEnterStation(Train *v, StationID station)
02779 {
02780   v->last_station_visited = station;
02781 
02782   /* check if a train ever visited this station before */
02783   Station *st = Station::Get(station);
02784   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02785     st->had_vehicle_of_type |= HVOT_TRAIN;
02786     SetDParam(0, st->index);
02787     AddVehicleNewsItem(
02788       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02789       v->owner == _local_company ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
02790       v->index,
02791       st->index
02792     );
02793     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02794     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02795   }
02796 
02797   v->force_proceed = TFP_NONE;
02798   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02799 
02800   v->BeginLoading();
02801 
02802   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02803 }
02804 
02805 /* Check if the vehicle is compatible with the specified tile */
02806 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02807 {
02808   return IsTileOwner(tile, v->owner) &&
02809       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02810 }
02811 
02813 struct AccelerationSlowdownParams {
02814   byte small_turn; 
02815   byte large_turn; 
02816   byte z_up;       
02817   byte z_down;     
02818 };
02819 
02821 static const AccelerationSlowdownParams _accel_slowdown[] = {
02822   /* normal accel */
02823   {256 / 4, 256 / 2, 256 / 4, 2}, 
02824   {256 / 4, 256 / 2, 256 / 4, 2}, 
02825   {0,       256 / 2, 256 / 4, 2}, 
02826 };
02827 
02833 static inline void AffectSpeedByZChange(Train *v, int old_z)
02834 {
02835   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02836 
02837   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02838 
02839   if (old_z < v->z_pos) {
02840     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02841   } else {
02842     uint16 spd = v->cur_speed + asp->z_down;
02843     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02844   }
02845 }
02846 
02847 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02848 {
02849   if (IsTileType(tile, MP_RAILWAY) &&
02850       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02851     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02852     Trackdir trackdir = FindFirstTrackdir(tracks);
02853     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02854       /* A PBS block with a non-PBS signal facing us? */
02855       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02856     }
02857   }
02858   return false;
02859 }
02860 
02862 void Train::ReserveTrackUnderConsist() const
02863 {
02864   for (const Train *u = this; u != NULL; u = u->Next()) {
02865     switch (u->track) {
02866       case TRACK_BIT_WORMHOLE:
02867         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02868         break;
02869       case TRACK_BIT_DEPOT:
02870         break;
02871       default:
02872         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02873         break;
02874     }
02875   }
02876 }
02877 
02884 uint Train::Crash(bool flooded)
02885 {
02886   uint pass = 0;
02887   if (this->IsFrontEngine()) {
02888     pass += 2; // driver
02889 
02890     /* Remove the reserved path in front of the train if it is not stuck.
02891      * Also clear all reserved tracks the train is currently on. */
02892     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02893     for (const Train *v = this; v != NULL; v = v->Next()) {
02894       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02895       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02896         /* ClearPathReservation will not free the wormhole exit
02897          * if the train has just entered the wormhole. */
02898         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02899       }
02900     }
02901 
02902     /* we may need to update crossing we were approaching,
02903      * but must be updated after the train has been marked crashed */
02904     TileIndex crossing = TrainApproachingCrossingTile(this);
02905     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02906 
02907     /* Remove the loading indicators (if any) */
02908     HideFillingPercent(&this->fill_percent_te_id);
02909   }
02910 
02911   pass += this->GroundVehicleBase::Crash(flooded);
02912 
02913   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02914   return pass;
02915 }
02916 
02923 static uint TrainCrashed(Train *v)
02924 {
02925   uint num = 0;
02926 
02927   /* do not crash train twice */
02928   if (!(v->vehstatus & VS_CRASHED)) {
02929     num = v->Crash();
02930     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02931     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02932   }
02933 
02934   /* Try to re-reserve track under already crashed train too.
02935    * Crash() clears the reservation! */
02936   v->ReserveTrackUnderConsist();
02937 
02938   return num;
02939 }
02940 
02942 struct TrainCollideChecker {
02943   Train *v; 
02944   uint num; 
02945 };
02946 
02953 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02954 {
02955   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02956 
02957   /* not a train or in depot */
02958   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02959 
02960   /* do not crash into trains of another company. */
02961   if (v->owner != tcc->v->owner) return NULL;
02962 
02963   /* get first vehicle now to make most usual checks faster */
02964   Train *coll = Train::From(v)->First();
02965 
02966   /* can't collide with own wagons */
02967   if (coll == tcc->v) return NULL;
02968 
02969   int x_diff = v->x_pos - tcc->v->x_pos;
02970   int y_diff = v->y_pos - tcc->v->y_pos;
02971 
02972   /* Do fast calculation to check whether trains are not in close vicinity
02973    * and quickly reject trains distant enough for any collision.
02974    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02975    * Differences are then ORed and then we check for any higher bits */
02976   uint hash = (y_diff + 7) | (x_diff + 7);
02977   if (hash & ~15) return NULL;
02978 
02979   /* Slower check using multiplication */
02980   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02981   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02982 
02983   /* Happens when there is a train under bridge next to bridge head */
02984   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02985 
02986   /* crash both trains */
02987   tcc->num += TrainCrashed(tcc->v);
02988   tcc->num += TrainCrashed(coll);
02989 
02990   return NULL; // continue searching
02991 }
02992 
03000 static bool CheckTrainCollision(Train *v)
03001 {
03002   /* can't collide in depot */
03003   if (v->track == TRACK_BIT_DEPOT) return false;
03004 
03005   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03006 
03007   TrainCollideChecker tcc;
03008   tcc.v = v;
03009   tcc.num = 0;
03010 
03011   /* find colliding vehicles */
03012   if (v->track == TRACK_BIT_WORMHOLE) {
03013     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03014     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03015   } else {
03016     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03017   }
03018 
03019   /* any dead -> no crash */
03020   if (tcc.num == 0) return false;
03021 
03022   SetDParam(0, tcc.num);
03023   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH, NT_ACCIDENT, v->index);
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           AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_STUCK, v->index);
03773         }
03774         v->wait_counter = 0;
03775       }
03776       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03777       if (v->force_proceed == TFP_NONE) return true;
03778       ClrBit(v->flags, VRF_TRAIN_STUCK);
03779       v->wait_counter = 0;
03780       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03781     }
03782   }
03783 
03784   if (v->current_order.IsType(OT_LEAVESTATION)) {
03785     v->current_order.Free();
03786     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03787     return true;
03788   }
03789 
03790   int j = v->UpdateSpeed();
03791 
03792   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03793   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03794     /* If we manually stopped, we're not force-proceeding anymore. */
03795     v->force_proceed = TFP_NONE;
03796     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03797   }
03798 
03799   int adv_spd = v->GetAdvanceDistance();
03800   if (j < adv_spd) {
03801     /* if the vehicle has speed 0, update the last_speed field. */
03802     if (v->cur_speed == 0) v->SetLastSpeed();
03803   } else {
03804     TrainCheckIfLineEnds(v);
03805     /* Loop until the train has finished moving. */
03806     for (;;) {
03807       j -= adv_spd;
03808       TrainController(v, NULL);
03809       /* Don't continue to move if the train crashed. */
03810       if (CheckTrainCollision(v)) break;
03811       /* Determine distance to next map position */
03812       adv_spd = v->GetAdvanceDistance();
03813 
03814       /* No more moving this tick */
03815       if (j < adv_spd || v->cur_speed == 0) break;
03816 
03817       OrderType order_type = v->current_order.GetType();
03818       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03819       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03820             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03821             IsTileType(v->tile, MP_STATION) &&
03822             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03823         ProcessOrders(v);
03824       }
03825     }
03826     v->SetLastSpeed();
03827   }
03828 
03829   for (Train *u = v; u != NULL; u = u->Next()) {
03830     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03831 
03832     u->UpdateViewport(false, false);
03833   }
03834 
03835   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03836 
03837   return true;
03838 }
03839 
03844 Money Train::GetRunningCost() const
03845 {
03846   Money cost = 0;
03847   const Train *v = this;
03848 
03849   do {
03850     const Engine *e = v->GetEngine();
03851     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03852 
03853     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03854     if (cost_factor == 0) continue;
03855 
03856     /* Halve running cost for multiheaded parts */
03857     if (v->IsMultiheaded()) cost_factor /= 2;
03858 
03859     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03860   } while ((v = v->GetNextVehicle()) != NULL);
03861 
03862   return cost;
03863 }
03864 
03869 bool Train::Tick()
03870 {
03871   this->tick_counter++;
03872 
03873   if (this->IsFrontEngine()) {
03874     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03875 
03876     this->current_order_time++;
03877 
03878     if (!TrainLocoHandler(this, false)) return false;
03879 
03880     return TrainLocoHandler(this, true);
03881   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03882     /* Delete flooded standalone wagon chain */
03883     if (++this->crash_anim_pos >= 4400) {
03884       delete this;
03885       return false;
03886     }
03887   }
03888 
03889   return true;
03890 }
03891 
03896 static void CheckIfTrainNeedsService(Train *v)
03897 {
03898   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03899   if (v->IsInDepot()) {
03900     VehicleServiceInDepot(v);
03901     return;
03902   }
03903 
03904   uint max_penalty;
03905   switch (_settings_game.pf.pathfinder_for_trains) {
03906     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03907     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03908     default: NOT_REACHED();
03909   }
03910 
03911   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03912   /* Only go to the depot if it is not too far out of our way. */
03913   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03914     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03915       /* If we were already heading for a depot but it has
03916        * suddenly moved farther away, we continue our normal
03917        * schedule? */
03918       v->current_order.MakeDummy();
03919       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03920     }
03921     return;
03922   }
03923 
03924   DepotID depot = GetDepotIndex(tfdd.tile);
03925 
03926   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03927       v->current_order.GetDestination() != depot &&
03928       !Chance16(3, 16)) {
03929     return;
03930   }
03931 
03932   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03933   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03934   v->dest_tile = tfdd.tile;
03935   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03936 }
03937 
03939 void Train::OnNewDay()
03940 {
03941   AgeVehicle(this);
03942 
03943   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03944 
03945   if (this->IsFrontEngine()) {
03946     CheckVehicleBreakdown(this);
03947 
03948     CheckIfTrainNeedsService(this);
03949 
03950     CheckOrders(this);
03951 
03952     /* update destination */
03953     if (this->current_order.IsType(OT_GOTO_STATION)) {
03954       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03955       if (tile != INVALID_TILE) this->dest_tile = tile;
03956     }
03957 
03958     if (this->running_ticks != 0) {
03959       /* running costs */
03960       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03961 
03962       this->profit_this_year -= cost.GetCost();
03963       this->running_ticks = 0;
03964 
03965       SubtractMoneyFromCompanyFract(this->owner, cost);
03966 
03967       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03968       SetWindowClassesDirty(WC_TRAINS_LIST);
03969     }
03970   }
03971 }
03972 
03977 Trackdir Train::GetVehicleTrackdir() const
03978 {
03979   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03980 
03981   if (this->track == TRACK_BIT_DEPOT) {
03982     /* We'll assume the train is facing outwards */
03983     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03984   }
03985 
03986   if (this->track == TRACK_BIT_WORMHOLE) {
03987     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03988     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03989   }
03990 
03991   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03992 }