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 
00212       if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00213         ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00214       }
00215     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00216       /* Use callback 11 */
00217       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00218     }
00219     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00220     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00221 
00222     /* verify length hasn't changed */
00223     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00224 
00225     /* update vehicle length? */
00226     if (!same_length) u->gcache.cached_veh_length = veh_len;
00227 
00228     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00229     this->InvalidateNewGRFCache();
00230     u->InvalidateNewGRFCache();
00231   }
00232 
00233   /* store consist weight/max speed in cache */
00234   this->vcache.cached_max_speed = max_speed;
00235   this->tcache.cached_tilt = train_can_tilt;
00236   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00237 
00238   /* 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) */
00239   this->CargoChanged();
00240 
00241   if (this->IsFrontEngine()) {
00242     this->UpdateAcceleration();
00243     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00244     InvalidateWindowData(WC_VEHICLE_REFIT, this->index, VIWD_CONSIST_CHANGED);
00245     InvalidateWindowData(WC_VEHICLE_ORDERS, this->index, VIWD_CONSIST_CHANGED);
00246   }
00247 }
00248 
00259 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00260 {
00261   const Station *st = Station::Get(station_id);
00262   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00263   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00264 
00265   /* Default to the middle of the station for stations stops that are not in
00266    * the order list like intermediate stations when non-stop is disabled */
00267   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00268   if (v->gcache.cached_total_length >= *station_length) {
00269     /* The train is longer than the station, make it stop at the far end of the platform */
00270     osl = OSL_PLATFORM_FAR_END;
00271   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00272     osl = v->current_order.GetStopLocation();
00273   }
00274 
00275   /* The stop location of the FRONT! of the train */
00276   int stop;
00277   switch (osl) {
00278     default: NOT_REACHED();
00279 
00280     case OSL_PLATFORM_NEAR_END:
00281       stop = v->gcache.cached_total_length;
00282       break;
00283 
00284     case OSL_PLATFORM_MIDDLE:
00285       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00286       break;
00287 
00288     case OSL_PLATFORM_FAR_END:
00289       stop = *station_length;
00290       break;
00291   }
00292 
00293   /* Subtract half the front vehicle length of the train so we get the real
00294    * stop location of the train. */
00295   return stop - (v->gcache.cached_veh_length + 1) / 2;
00296 }
00297 
00298 
00303 int Train::GetCurveSpeedLimit() const
00304 {
00305   assert(this->First() == this);
00306 
00307   static const int absolute_max_speed = UINT16_MAX;
00308   int max_speed = absolute_max_speed;
00309 
00310   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00311 
00312   int curvecount[2] = {0, 0};
00313 
00314   /* first find the curve speed limit */
00315   int numcurve = 0;
00316   int sum = 0;
00317   int pos = 0;
00318   int lastpos = -1;
00319   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00320     Direction this_dir = u->direction;
00321     Direction next_dir = u->Next()->direction;
00322 
00323     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00324     if (dirdiff == DIRDIFF_SAME) continue;
00325 
00326     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00327     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00328     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00329       if (lastpos != -1) {
00330         numcurve++;
00331         sum += pos - lastpos;
00332         if (pos - lastpos == 1 && max_speed > 88) {
00333           max_speed = 88;
00334         }
00335       }
00336       lastpos = pos;
00337     }
00338 
00339     /* if we have a 90 degree turn, fix the speed limit to 60 */
00340     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00341       max_speed = 61;
00342     }
00343   }
00344 
00345   if (numcurve > 0 && max_speed > 88) {
00346     if (curvecount[0] == 1 && curvecount[1] == 1) {
00347       max_speed = absolute_max_speed;
00348     } else {
00349       sum /= numcurve;
00350       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00351     }
00352   }
00353 
00354   if (max_speed != absolute_max_speed) {
00355     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00356     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00357     max_speed += (max_speed / 2) * rti->curve_speed;
00358 
00359     if (this->tcache.cached_tilt) {
00360       /* Apply max_speed bonus of 20% for a tilting train */
00361       max_speed += max_speed / 5;
00362     }
00363   }
00364 
00365   return max_speed;
00366 }
00367 
00372 int Train::GetCurrentMaxSpeed() const
00373 {
00374   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return min(this->gcache.cached_max_track_speed, this->current_order.max_speed);
00375 
00376   int max_speed = this->tcache.cached_max_curve_speed;
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     /* Vehicle is on the middle part of a bridge. */
00409     if (u->track == TRACK_BIT_WORMHOLE && !(u->vehstatus & VS_HIDDEN)) {
00410       max_speed = min(max_speed, GetBridgeSpec(GetBridgeType(u->tile))->speed);
00411     }
00412   }
00413 
00414   max_speed = min(max_speed, this->current_order.max_speed);
00415   return min(max_speed, this->gcache.cached_max_track_speed);
00416 }
00417 
00419 void Train::UpdateAcceleration()
00420 {
00421   assert(this->IsFrontEngine());
00422 
00423   uint power = this->gcache.cached_power;
00424   uint weight = this->gcache.cached_weight;
00425   assert(weight != 0);
00426   this->acceleration = Clamp(power / weight * 4, 1, 255);
00427 }
00428 
00434 int Train::GetDisplayImageWidth(Point *offset) const
00435 {
00436   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00437   int vehicle_pitch = 0;
00438 
00439   const Engine *e = this->GetEngine();
00440   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00441     reference_width = e->GetGRF()->traininfo_vehicle_width;
00442     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00443   }
00444 
00445   if (offset != NULL) {
00446     offset->x = reference_width / 2;
00447     offset->y = vehicle_pitch;
00448   }
00449   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00450 }
00451 
00452 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00453 {
00454   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00455 }
00456 
00463 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00464 {
00465   uint8 spritenum = this->spritenum;
00466   SpriteID sprite;
00467 
00468   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00469 
00470   if (is_custom_sprite(spritenum)) {
00471     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00472     if (sprite != 0) return sprite;
00473 
00474     spritenum = this->GetEngine()->original_image_index;
00475   }
00476 
00477   sprite = GetDefaultTrainSprite(spritenum, direction);
00478 
00479   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00480 
00481   return sprite;
00482 }
00483 
00484 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00485 {
00486   const Engine *e = Engine::Get(engine);
00487   Direction dir = rear_head ? DIR_E : DIR_W;
00488   uint8 spritenum = e->u.rail.image_index;
00489 
00490   if (is_custom_sprite(spritenum)) {
00491     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00492     if (sprite != 0) {
00493       if (e->GetGRF() != NULL) {
00494         y += e->GetGRF()->traininfo_vehicle_pitch;
00495       }
00496       return sprite;
00497     }
00498 
00499     spritenum = Engine::Get(engine)->original_image_index;
00500   }
00501 
00502   if (rear_head) spritenum++;
00503 
00504   return GetDefaultTrainSprite(spritenum, DIR_W);
00505 }
00506 
00507 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00508 {
00509   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00510     int yf = y;
00511     int yr = y;
00512 
00513     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00514     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00515     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00516     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00517 
00518     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);
00519 
00520     DrawSprite(spritef, pal, preferred_x - 14, yf);
00521     DrawSprite(spriter, pal, preferred_x + 15, yr);
00522   } else {
00523     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00524     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00525     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));
00526     DrawSprite(sprite, pal, preferred_x, y);
00527   }
00528 }
00529 
00539 void GetTrainSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type)
00540 {
00541   int y = 0;
00542 
00543   SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00544   const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00545 
00546   width  = UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI);
00547   height = UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI);
00548   xoffs  = UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI);
00549   yoffs  = UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI);
00550 
00551   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00552     sprite = GetRailIcon(engine, true, y, image_type);
00553     real_sprite = GetSprite(sprite, ST_NORMAL);
00554 
00555     /* Calculate values relative to an imaginary center between the two sprites. */
00556     width = TRAININFO_DEFAULT_VEHICLE_WIDTH + UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) + UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI) - xoffs;
00557     height = max<uint>(height, UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI));
00558     xoffs  = xoffs - TRAININFO_DEFAULT_VEHICLE_WIDTH / 2;
00559     yoffs  = min(yoffs, UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI));
00560   }
00561 }
00562 
00571 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00572 {
00573   const RailVehicleInfo *rvi = &e->u.rail;
00574 
00575   /* Check that the wagon can drive on the track in question */
00576   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00577 
00578   if (flags & DC_EXEC) {
00579     Train *v = new Train();
00580     *ret = v;
00581     v->spritenum = rvi->image_index;
00582 
00583     v->engine_type = e->index;
00584     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00585 
00586     DiagDirection dir = GetRailDepotDirection(tile);
00587 
00588     v->direction = DiagDirToDir(dir);
00589     v->tile = tile;
00590 
00591     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00592     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00593 
00594     v->x_pos = x;
00595     v->y_pos = y;
00596     v->z_pos = GetSlopePixelZ(x, y);
00597     v->owner = _current_company;
00598     v->track = TRACK_BIT_DEPOT;
00599     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00600 
00601     v->SetWagon();
00602 
00603     v->SetFreeWagon();
00604     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00605 
00606     v->cargo_type = e->GetDefaultCargoType();
00607     v->cargo_cap = rvi->capacity;
00608 
00609     v->railtype = rvi->railtype;
00610 
00611     v->build_year = _cur_year;
00612     v->cur_image = SPR_IMG_QUERY;
00613     v->random_bits = VehicleRandomBits();
00614 
00615     v->group_id = DEFAULT_GROUP;
00616 
00617     AddArticulatedParts(v);
00618 
00619     _new_vehicle_id = v->index;
00620 
00621     VehicleUpdatePosition(v);
00622     v->First()->ConsistChanged(false);
00623     UpdateTrainGroupID(v->First());
00624 
00625     CheckConsistencyOfArticulatedVehicle(v);
00626 
00627     /* Try to connect the vehicle to one of free chains of wagons. */
00628     Train *w;
00629     FOR_ALL_TRAINS(w) {
00630       if (w->tile == tile &&              
00631           w->IsFreeWagon() &&             
00632           w->engine_type == e->index &&   
00633           w->First() != v &&              
00634           !(w->vehstatus & VS_CRASHED)) { 
00635         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00636         break;
00637       }
00638     }
00639   }
00640 
00641   return CommandCost();
00642 }
00643 
00645 static void NormalizeTrainVehInDepot(const Train *u)
00646 {
00647   const Train *v;
00648   FOR_ALL_TRAINS(v) {
00649     if (v->IsFreeWagon() && v->tile == u->tile &&
00650         v->track == TRACK_BIT_DEPOT) {
00651       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00652           CMD_MOVE_RAIL_VEHICLE).Failed())
00653         break;
00654     }
00655   }
00656 }
00657 
00658 static void AddRearEngineToMultiheadedTrain(Train *v)
00659 {
00660   Train *u = new Train();
00661   v->value >>= 1;
00662   u->value = v->value;
00663   u->direction = v->direction;
00664   u->owner = v->owner;
00665   u->tile = v->tile;
00666   u->x_pos = v->x_pos;
00667   u->y_pos = v->y_pos;
00668   u->z_pos = v->z_pos;
00669   u->track = TRACK_BIT_DEPOT;
00670   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00671   u->spritenum = v->spritenum + 1;
00672   u->cargo_type = v->cargo_type;
00673   u->cargo_subtype = v->cargo_subtype;
00674   u->cargo_cap = v->cargo_cap;
00675   u->railtype = v->railtype;
00676   u->engine_type = v->engine_type;
00677   u->build_year = v->build_year;
00678   u->cur_image = SPR_IMG_QUERY;
00679   u->random_bits = VehicleRandomBits();
00680   v->SetMultiheaded();
00681   u->SetMultiheaded();
00682   v->SetNext(u);
00683   VehicleUpdatePosition(u);
00684 
00685   /* Now we need to link the front and rear engines together */
00686   v->other_multiheaded_part = u;
00687   u->other_multiheaded_part = v;
00688 }
00689 
00699 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00700 {
00701   const RailVehicleInfo *rvi = &e->u.rail;
00702 
00703   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00704 
00705   /* Check if depot and new engine uses the same kind of tracks *
00706    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00707   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00708 
00709   if (flags & DC_EXEC) {
00710     DiagDirection dir = GetRailDepotDirection(tile);
00711     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00712     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00713 
00714     Train *v = new Train();
00715     *ret = v;
00716     v->direction = DiagDirToDir(dir);
00717     v->tile = tile;
00718     v->owner = _current_company;
00719     v->x_pos = x;
00720     v->y_pos = y;
00721     v->z_pos = GetSlopePixelZ(x, y);
00722     v->track = TRACK_BIT_DEPOT;
00723     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00724     v->spritenum = rvi->image_index;
00725     v->cargo_type = e->GetDefaultCargoType();
00726     v->cargo_cap = rvi->capacity;
00727     v->last_station_visited = INVALID_STATION;
00728     v->last_loading_station = INVALID_STATION;
00729 
00730     v->engine_type = e->index;
00731     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00732 
00733     v->reliability = e->reliability;
00734     v->reliability_spd_dec = e->reliability_spd_dec;
00735     v->max_age = e->GetLifeLengthInDays();
00736 
00737     v->railtype = rvi->railtype;
00738     _new_vehicle_id = v->index;
00739 
00740     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00741     v->date_of_last_service = _date;
00742     v->build_year = _cur_year;
00743     v->cur_image = SPR_IMG_QUERY;
00744     v->random_bits = VehicleRandomBits();
00745 
00746     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00747 
00748     v->group_id = DEFAULT_GROUP;
00749 
00750     v->SetFrontEngine();
00751     v->SetEngine();
00752 
00753     VehicleUpdatePosition(v);
00754 
00755     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00756       AddRearEngineToMultiheadedTrain(v);
00757     } else {
00758       AddArticulatedParts(v);
00759     }
00760 
00761     v->ConsistChanged(false);
00762     UpdateTrainGroupID(v);
00763 
00764     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00765       NormalizeTrainVehInDepot(v);
00766     }
00767 
00768     CheckConsistencyOfArticulatedVehicle(v);
00769   }
00770 
00771   return CommandCost();
00772 }
00773 
00774 static Train *FindGoodVehiclePos(const Train *src)
00775 {
00776   EngineID eng = src->engine_type;
00777   TileIndex tile = src->tile;
00778 
00779   Train *dst;
00780   FOR_ALL_TRAINS(dst) {
00781     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00782       /* check so all vehicles in the line have the same engine. */
00783       Train *t = dst;
00784       while (t->engine_type == eng) {
00785         t = t->Next();
00786         if (t == NULL) return dst;
00787       }
00788     }
00789   }
00790 
00791   return NULL;
00792 }
00793 
00795 typedef SmallVector<Train *, 16> TrainList;
00796 
00802 static void MakeTrainBackup(TrainList &list, Train *t)
00803 {
00804   for (; t != NULL; t = t->Next()) *list.Append() = t;
00805 }
00806 
00811 static void RestoreTrainBackup(TrainList &list)
00812 {
00813   /* No train, nothing to do. */
00814   if (list.Length() == 0) return;
00815 
00816   Train *prev = NULL;
00817   /* Iterate over the list and rebuild it. */
00818   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00819     Train *t = *iter;
00820     if (prev != NULL) {
00821       prev->SetNext(t);
00822     } else if (t->Previous() != NULL) {
00823       /* Make sure the head of the train is always the first in the chain. */
00824       t->Previous()->SetNext(NULL);
00825     }
00826     prev = t;
00827   }
00828 }
00829 
00835 static void RemoveFromConsist(Train *part, bool chain = false)
00836 {
00837   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00838 
00839   /* Unlink at the front, but make it point to the next
00840    * vehicle after the to be remove part. */
00841   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00842 
00843   /* Unlink at the back */
00844   tail->SetNext(NULL);
00845 }
00846 
00852 static void InsertInConsist(Train *dst, Train *chain)
00853 {
00854   /* We do not want to add something in the middle of an articulated part. */
00855   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00856 
00857   chain->Last()->SetNext(dst->Next());
00858   dst->SetNext(chain);
00859 }
00860 
00866 static void NormaliseDualHeads(Train *t)
00867 {
00868   for (; t != NULL; t = t->GetNextVehicle()) {
00869     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00870 
00871     /* Make sure that there are no free cars before next engine */
00872     Train *u;
00873     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00874 
00875     if (u == t->other_multiheaded_part) continue;
00876 
00877     /* Remove the part from the 'wrong' train */
00878     RemoveFromConsist(t->other_multiheaded_part);
00879     /* And add it to the 'right' train */
00880     InsertInConsist(u, t->other_multiheaded_part);
00881   }
00882 }
00883 
00888 static void NormaliseSubtypes(Train *chain)
00889 {
00890   /* Nothing to do */
00891   if (chain == NULL) return;
00892 
00893   /* We must be the first in the chain. */
00894   assert(chain->Previous() == NULL);
00895 
00896   /* Set the appropriate bits for the first in the chain. */
00897   if (chain->IsWagon()) {
00898     chain->SetFreeWagon();
00899   } else {
00900     assert(chain->IsEngine());
00901     chain->SetFrontEngine();
00902   }
00903 
00904   /* Now clear the bits for the rest of the chain */
00905   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00906     t->ClearFreeWagon();
00907     t->ClearFrontEngine();
00908   }
00909 }
00910 
00920 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00921 {
00922   /* Just add 'new' engines and subtract the original ones.
00923    * If that's less than or equal to 0 we can be sure we did
00924    * not add any engines (read: trains) along the way. */
00925   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00926       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00927       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00928       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00929     return CommandCost();
00930   }
00931 
00932   /* Get a free unit number and check whether it's within the bounds.
00933    * There will always be a maximum of one new train. */
00934   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00935 
00936   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00937 }
00938 
00944 static CommandCost CheckTrainAttachment(Train *t)
00945 {
00946   /* No multi-part train, no need to check. */
00947   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00948 
00949   /* The maximum length for a train. For each part we decrease this by one
00950    * and if the result is negative the train is simply too long. */
00951   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00952 
00953   Train *head = t;
00954   Train *prev = t;
00955 
00956   /* Break the prev -> t link so it always holds within the loop. */
00957   t = t->Next();
00958   prev->SetNext(NULL);
00959 
00960   /* Make sure the cache is cleared. */
00961   head->InvalidateNewGRFCache();
00962 
00963   while (t != NULL) {
00964     allowed_len -= t->gcache.cached_veh_length;
00965 
00966     Train *next = t->Next();
00967 
00968     /* Unlink the to-be-added piece; it is already unlinked from the previous
00969      * part due to the fact that the prev -> t link is broken. */
00970     t->SetNext(NULL);
00971 
00972     /* Don't check callback for articulated or rear dual headed parts */
00973     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00974       /* Back up and clear the first_engine data to avoid using wagon override group */
00975       EngineID first_engine = t->gcache.first_engine;
00976       t->gcache.first_engine = INVALID_ENGINE;
00977 
00978       /* We don't want the cache to interfere. head's cache is cleared before
00979        * the loop and after each callback does not need to be cleared here. */
00980       t->InvalidateNewGRFCache();
00981 
00982       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00983 
00984       /* Restore original first_engine data */
00985       t->gcache.first_engine = first_engine;
00986 
00987       /* We do not want to remember any cached variables from the test run */
00988       t->InvalidateNewGRFCache();
00989       head->InvalidateNewGRFCache();
00990 
00991       if (callback != CALLBACK_FAILED) {
00992         /* A failing callback means everything is okay */
00993         StringID error = STR_NULL;
00994 
00995         if (head->GetGRF()->grf_version < 8) {
00996           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00997           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00998           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00999         } else {
01000           if (callback < 0x400) {
01001             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01002           } else {
01003             switch (callback) {
01004               case 0x400: // allow if railtypes match (always the case for OpenTTD)
01005               case 0x401: // allow
01006                 break;
01007 
01008               default:    // unknown reason -> disallow
01009               case 0x402: // disallow attaching
01010                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01011                 break;
01012             }
01013           }
01014         }
01015 
01016         if (error != STR_NULL) return_cmd_error(error);
01017       }
01018     }
01019 
01020     /* And link it to the new part. */
01021     prev->SetNext(t);
01022     prev = t;
01023     t = next;
01024   }
01025 
01026   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01027   return CommandCost();
01028 }
01029 
01040 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01041 {
01042   /* Check whether we may actually construct the trains. */
01043   CommandCost ret = CheckTrainAttachment(src);
01044   if (ret.Failed()) return ret;
01045   ret = CheckTrainAttachment(dst);
01046   if (ret.Failed()) return ret;
01047 
01048   /* Check whether we need to build a new train. */
01049   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01050 }
01051 
01060 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01061 {
01062   /* First determine the front of the two resulting trains */
01063   if (*src_head == *dst_head) {
01064     /* If we aren't moving part(s) to a new train, we are just moving the
01065      * front back and there is not destination head. */
01066     *dst_head = NULL;
01067   } else if (*dst_head == NULL) {
01068     /* If we are moving to a new train the head of the move train would become
01069      * the head of the new vehicle. */
01070     *dst_head = src;
01071   }
01072 
01073   if (src == *src_head) {
01074     /* If we are moving the front of a train then we are, in effect, creating
01075      * a new head for the train. Point to that. Unless we are moving the whole
01076      * train in which case there is not 'source' train anymore.
01077      * In case we are a multiheaded part we want the complete thing to come
01078      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01079      * that is followed by a rear multihead we do not want to include that. */
01080     *src_head = move_chain ? NULL :
01081         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01082   }
01083 
01084   /* Now it's just simply removing the part that we are going to move from the
01085    * source train and *if* the destination is a not a new train add the chain
01086    * at the destination location. */
01087   RemoveFromConsist(src, move_chain);
01088   if (*dst_head != src) InsertInConsist(dst, src);
01089 
01090   /* Now normalise the dual heads, that is move the dual heads around in such
01091    * a way that the head and rear of a dual head are in the same train */
01092   NormaliseDualHeads(*src_head);
01093   NormaliseDualHeads(*dst_head);
01094 }
01095 
01101 static void NormaliseTrainHead(Train *head)
01102 {
01103   /* Not much to do! */
01104   if (head == NULL) return;
01105 
01106   /* Tell the 'world' the train changed. */
01107   head->ConsistChanged(false);
01108   UpdateTrainGroupID(head);
01109 
01110   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01111   if (!head->IsFrontEngine()) return;
01112 
01113   /* Update the refit button and window */
01114   InvalidateWindowData(WC_VEHICLE_REFIT, head->index, VIWD_CONSIST_CHANGED);
01115   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01116 
01117   /* If we don't have a unit number yet, set one. */
01118   if (head->unitnumber != 0) return;
01119   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01120 }
01121 
01134 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01135 {
01136   VehicleID s = GB(p1, 0, 20);
01137   VehicleID d = GB(p2, 0, 20);
01138   bool move_chain = HasBit(p1, 20);
01139 
01140   Train *src = Train::GetIfValid(s);
01141   if (src == NULL) return CMD_ERROR;
01142 
01143   CommandCost ret = CheckOwnership(src->owner);
01144   if (ret.Failed()) return ret;
01145 
01146   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01147   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01148 
01149   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01150   Train *dst;
01151   if (d == INVALID_VEHICLE) {
01152     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01153   } else {
01154     dst = Train::GetIfValid(d);
01155     if (dst == NULL) return CMD_ERROR;
01156 
01157     CommandCost ret = CheckOwnership(dst->owner);
01158     if (ret.Failed()) return ret;
01159 
01160     /* Do not allow appending to crashed vehicles, too */
01161     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01162   }
01163 
01164   /* if an articulated part is being handled, deal with its parent vehicle */
01165   src = src->GetFirstEnginePart();
01166   if (dst != NULL) {
01167     dst = dst->GetFirstEnginePart();
01168   }
01169 
01170   /* don't move the same vehicle.. */
01171   if (src == dst) return CommandCost();
01172 
01173   /* locate the head of the two chains */
01174   Train *src_head = src->First();
01175   Train *dst_head;
01176   if (dst != NULL) {
01177     dst_head = dst->First();
01178     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01179     /* Now deal with articulated part of destination wagon */
01180     dst = dst->GetLastEnginePart();
01181   } else {
01182     dst_head = NULL;
01183   }
01184 
01185   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01186 
01187   /* When moving all wagons, we can't have the same src_head and dst_head */
01188   if (move_chain && src_head == dst_head) return CommandCost();
01189 
01190   /* When moving a multiheaded part to be place after itself, bail out. */
01191   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01192 
01193   /* Check if all vehicles in the source train are stopped inside a depot. */
01194   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01195 
01196   /* Check if all vehicles in the destination train are stopped inside a depot. */
01197   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01198 
01199   /* First make a backup of the order of the trains. That way we can do
01200    * whatever we want with the order and later on easily revert. */
01201   TrainList original_src;
01202   TrainList original_dst;
01203 
01204   MakeTrainBackup(original_src, src_head);
01205   MakeTrainBackup(original_dst, dst_head);
01206 
01207   /* Also make backup of the original heads as ArrangeTrains can change them.
01208    * For the destination head we do not care if it is the same as the source
01209    * head because in that case it's just a copy. */
01210   Train *original_src_head = src_head;
01211   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01212 
01213   /* We want this information from before the rearrangement, but execute this after the validation. */
01214   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01215   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01216 
01217   /* (Re)arrange the trains in the wanted arrangement. */
01218   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01219 
01220   if ((flags & DC_AUTOREPLACE) == 0) {
01221     /* If the autoreplace flag is set we do not need to test for the validity
01222      * because we are going to revert the train to its original state. As we
01223      * assume the original state was correct autoreplace can skip this. */
01224     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01225     if (ret.Failed()) {
01226       /* Restore the train we had. */
01227       RestoreTrainBackup(original_src);
01228       RestoreTrainBackup(original_dst);
01229       return ret;
01230     }
01231   }
01232 
01233   /* do it? */
01234   if (flags & DC_EXEC) {
01235     /* Remove old heads from the statistics */
01236     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01237     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01238 
01239     /* First normalise the sub types of the chains. */
01240     NormaliseSubtypes(src_head);
01241     NormaliseSubtypes(dst_head);
01242 
01243     /* There are 14 different cases:
01244      *  1) front engine gets moved to a new train, it stays a front engine.
01245      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01246      *     b) the 'next' part is an engine that becomes a front engine.
01247      *     c) there is no 'next' part, nothing else happens
01248      *  2) front engine gets moved to another train, it is not a front engine anymore
01249      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01250      *     b) the 'next' part is an engine that becomes a front engine.
01251      *     c) there is no 'next' part, nothing else happens
01252      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01253      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01254      *     b) the 'next' part is an engine that becomes a front engine.
01255      *  4) free wagon gets moved
01256      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01257      *     b) the 'next' part is an engine that becomes a front engine.
01258      *     c) there is no 'next' part, nothing else happens
01259      *  5) non front engine gets moved and becomes a new train, nothing else happens
01260      *  6) non front engine gets moved within a train / to another train, nothing hapens
01261      *  7) wagon gets moved, nothing happens
01262      */
01263     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01264       /* Cases #2 and #3: the front engine gets trashed. */
01265       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01266       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01267       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01268       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01269       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01270       SetWindowDirty(WC_COMPANY, _current_company);
01271 
01272       /* Delete orders, group stuff and the unit number as we're not the
01273        * front of any vehicle anymore. */
01274       DeleteVehicleOrders(src);
01275       RemoveVehicleFromGroup(src);
01276       src->unitnumber = 0;
01277     }
01278 
01279     /* We weren't a front engine but are becoming one. So
01280      * we should be put in the default group. */
01281     if (original_src_head != src && dst_head == src) {
01282       SetTrainGroupID(src, DEFAULT_GROUP);
01283       SetWindowDirty(WC_COMPANY, _current_company);
01284     }
01285 
01286     /* Add new heads to statistics */
01287     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01288     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01289 
01290     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01291     NormaliseTrainHead(src_head);
01292     NormaliseTrainHead(dst_head);
01293 
01294     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01295       CheckCargoCapacity(src_head);
01296       CheckCargoCapacity(dst_head);
01297     }
01298 
01299     /* We are undoubtedly changing something in the depot and train list. */
01300     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01301     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01302   } else {
01303     /* We don't want to execute what we're just tried. */
01304     RestoreTrainBackup(original_src);
01305     RestoreTrainBackup(original_dst);
01306   }
01307 
01308   return CommandCost();
01309 }
01310 
01322 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01323 {
01324   /* Check if we deleted a vehicle window */
01325   Window *w = NULL;
01326 
01327   /* Sell a chain of vehicles or not? */
01328   bool sell_chain = HasBit(data, 0);
01329 
01330   Train *v = Train::From(t)->GetFirstEnginePart();
01331   Train *first = v->First();
01332 
01333   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01334 
01335   /* First make a backup of the order of the train. That way we can do
01336    * whatever we want with the order and later on easily revert. */
01337   TrainList original;
01338   MakeTrainBackup(original, first);
01339 
01340   /* We need to keep track of the new head and the head of what we're going to sell. */
01341   Train *new_head = first;
01342   Train *sell_head = NULL;
01343 
01344   /* Split the train in the wanted way. */
01345   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01346 
01347   /* We don't need to validate the second train; it's going to be sold. */
01348   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01349   if (ret.Failed()) {
01350     /* Restore the train we had. */
01351     RestoreTrainBackup(original);
01352     return ret;
01353   }
01354 
01355   CommandCost cost(EXPENSES_NEW_VEHICLES);
01356   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01357 
01358   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01359     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01360   }
01361 
01362   /* do it? */
01363   if (flags & DC_EXEC) {
01364     /* First normalise the sub types of the chain. */
01365     NormaliseSubtypes(new_head);
01366 
01367     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01368       /* We are selling the front engine. In this case we want to
01369        * 'give' the order, unit number and such to the new head. */
01370       new_head->orders.list = first->orders.list;
01371       new_head->AddToShared(first);
01372       DeleteVehicleOrders(first);
01373 
01374       /* Copy other important data from the front engine */
01375       new_head->CopyVehicleConfigAndStatistics(first);
01376       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01377 
01378       /* If we deleted a window then open a new one for the 'new' train */
01379       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01380     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01381       OrderBackup::Backup(v, user);
01382     }
01383 
01384     /* We need to update the information about the train. */
01385     NormaliseTrainHead(new_head);
01386 
01387     /* We are undoubtedly changing something in the depot and train list. */
01388     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01389     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01390 
01391     /* Actually delete the sold 'goods' */
01392     delete sell_head;
01393   } else {
01394     /* We don't want to execute what we're just tried. */
01395     RestoreTrainBackup(original);
01396   }
01397 
01398   return cost;
01399 }
01400 
01401 void Train::UpdateDeltaXY(Direction direction)
01402 {
01403   /* Set common defaults. */
01404   this->x_offs    = -1;
01405   this->y_offs    = -1;
01406   this->x_extent  =  3;
01407   this->y_extent  =  3;
01408   this->z_extent  =  6;
01409   this->x_bb_offs =  0;
01410   this->y_bb_offs =  0;
01411 
01412   if (!IsDiagonalDirection(direction)) {
01413     static const int _sign_table[] =
01414     {
01415       // x, y
01416       -1, -1, // DIR_N
01417       -1,  1, // DIR_E
01418        1,  1, // DIR_S
01419        1, -1, // DIR_W
01420     };
01421 
01422     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01423 
01424     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01425     this->x_offs -= half_shorten * _sign_table[direction];
01426     this->y_offs -= half_shorten * _sign_table[direction + 1];
01427     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01428     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01429   } else {
01430     switch (direction) {
01431         /* Shorten southern corner of the bounding box according the vehicle length
01432          * and center the bounding box on the vehicle. */
01433       case DIR_NE:
01434         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01435         this->x_extent  = this->gcache.cached_veh_length - 1;
01436         this->x_bb_offs = -1;
01437         break;
01438 
01439       case DIR_NW:
01440         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01441         this->y_extent  = this->gcache.cached_veh_length - 1;
01442         this->y_bb_offs = -1;
01443         break;
01444 
01445         /* Move northern corner of the bounding box down according to vehicle length
01446          * and center the bounding box on the vehicle. */
01447       case DIR_SW:
01448         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01449         this->x_extent  = VEHICLE_LENGTH - 1;
01450         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01451         break;
01452 
01453       case DIR_SE:
01454         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01455         this->y_extent  = VEHICLE_LENGTH - 1;
01456         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01457         break;
01458 
01459       default:
01460         NOT_REACHED();
01461     }
01462   }
01463 }
01464 
01469 static void MarkTrainAsStuck(Train *v)
01470 {
01471   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01472     /* It is the first time the problem occurred, set the "train stuck" flag. */
01473     SetBit(v->flags, VRF_TRAIN_STUCK);
01474 
01475     v->wait_counter = 0;
01476 
01477     /* Stop train */
01478     v->cur_speed = 0;
01479     v->subspeed = 0;
01480     v->SetLastSpeed();
01481 
01482     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01483   }
01484 }
01485 
01493 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01494 {
01495   uint16 flag1 = *swap_flag1;
01496   uint16 flag2 = *swap_flag2;
01497 
01498   /* Clear the flags */
01499   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01500   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01501   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01502   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01503 
01504   /* Reverse the rail-flags (if needed) */
01505   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01506     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01507   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01508     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01509   }
01510   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01511     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01512   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01513     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01514   }
01515 }
01516 
01521 static void UpdateStatusAfterSwap(Train *v)
01522 {
01523   /* Reverse the direction. */
01524   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01525 
01526   /* Call the proper EnterTile function unless we are in a wormhole. */
01527   if (v->track != TRACK_BIT_WORMHOLE) {
01528     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01529   } else {
01530     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01531      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01532      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01533      * when we shouldn't have. Check if this is the case. */
01534     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01535     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01536       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01537       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01538         /* We have just left the wormhole, possibly set the
01539          * "goingdown" bit. UpdateInclination() can be used
01540          * because we are at the border of the tile. */
01541         VehicleUpdatePosition(v);
01542         v->UpdateInclination(true, true);
01543         return;
01544       }
01545     }
01546   }
01547 
01548   VehicleUpdatePosition(v);
01549   v->UpdateViewport(true, true);
01550 }
01551 
01558 void ReverseTrainSwapVeh(Train *v, int l, int r)
01559 {
01560   Train *a, *b;
01561 
01562   /* locate vehicles to swap */
01563   for (a = v; l != 0; l--) a = a->Next();
01564   for (b = v; r != 0; r--) b = b->Next();
01565 
01566   if (a != b) {
01567     /* swap the hidden bits */
01568     {
01569       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01570       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01571       a->vehstatus = tmp;
01572     }
01573 
01574     Swap(a->track, b->track);
01575     Swap(a->direction, b->direction);
01576     Swap(a->x_pos, b->x_pos);
01577     Swap(a->y_pos, b->y_pos);
01578     Swap(a->tile,  b->tile);
01579     Swap(a->z_pos, b->z_pos);
01580 
01581     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01582 
01583     UpdateStatusAfterSwap(a);
01584     UpdateStatusAfterSwap(b);
01585   } else {
01586     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01587      * This is a little bit redundant way, a->gv_flags will
01588      * be (re)set twice, but it reduces code duplication */
01589     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01590     UpdateStatusAfterSwap(a);
01591   }
01592 }
01593 
01594 
01600 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01601 {
01602   return (v->type == VEH_TRAIN) ? v : NULL;
01603 }
01604 
01605 
01612 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01613 {
01614   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01615 
01616   Train *t = Train::From(v);
01617   if (!t->IsFrontEngine()) return NULL;
01618 
01619   TileIndex tile = *(TileIndex *)data;
01620 
01621   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01622 
01623   return t;
01624 }
01625 
01626 
01633 static bool TrainApproachingCrossing(TileIndex tile)
01634 {
01635   assert(IsLevelCrossingTile(tile));
01636 
01637   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01638   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01639 
01640   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01641 
01642   dir = ReverseDiagDir(dir);
01643   tile_from = tile + TileOffsByDiagDir(dir);
01644 
01645   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01646 }
01647 
01648 
01655 void UpdateLevelCrossing(TileIndex tile, bool sound)
01656 {
01657   assert(IsLevelCrossingTile(tile));
01658 
01659   /* train on crossing || train approaching crossing || reserved */
01660   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01661 
01662   if (new_state != IsCrossingBarred(tile)) {
01663     if (new_state && sound) {
01664       if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01665     }
01666     SetCrossingBarred(tile, new_state);
01667     MarkTileDirtyByTile(tile);
01668   }
01669 }
01670 
01671 
01677 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01678 {
01679   if (!IsCrossingBarred(tile)) {
01680     BarCrossing(tile);
01681     if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01682     MarkTileDirtyByTile(tile);
01683   }
01684 }
01685 
01686 
01692 static void AdvanceWagonsBeforeSwap(Train *v)
01693 {
01694   Train *base = v;
01695   Train *first = base; // first vehicle to move
01696   Train *last = v->Last(); // last vehicle to move
01697   uint length = CountVehiclesInChain(v);
01698 
01699   while (length > 2) {
01700     last = last->Previous();
01701     first = first->Next();
01702 
01703     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01704 
01705     /* do not update images now
01706      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01707     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01708 
01709     base = first; // == base->Next()
01710     length -= 2;
01711   }
01712 }
01713 
01714 
01720 static void AdvanceWagonsAfterSwap(Train *v)
01721 {
01722   /* first of all, fix the situation when the train was entering a depot */
01723   Train *dep = v; // last vehicle in front of just left depot
01724   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01725     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01726   }
01727 
01728   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01729 
01730   if (leave != NULL) {
01731     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01732     int d = TicksToLeaveDepot(dep);
01733 
01734     if (d <= 0) {
01735       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01736       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01737       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01738     }
01739   } else {
01740     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01741   }
01742 
01743   Train *base = v;
01744   Train *first = base; // first vehicle to move
01745   Train *last = v->Last(); // last vehicle to move
01746   uint length = CountVehiclesInChain(v);
01747 
01748   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01749    * they have already correct spacing, so we have to make sure they are moved how they should */
01750   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01751 
01752   while (length > 2) {
01753     /* we reached vehicle (originally) in front of a depot, stop now
01754      * (we would move wagons that are already moved with new wagon length). */
01755     if (base == dep) break;
01756 
01757     /* the last wagon was that one leaving a depot, so do not move it anymore */
01758     if (last == dep) nomove = true;
01759 
01760     last = last->Previous();
01761     first = first->Next();
01762 
01763     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01764 
01765     /* do not update images now */
01766     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01767 
01768     base = first; // == base->Next()
01769     length -= 2;
01770   }
01771 }
01772 
01777 void ReverseTrainDirection(Train *v)
01778 {
01779   if (IsRailDepotTile(v->tile)) {
01780     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01781   }
01782 
01783   /* Clear path reservation in front if train is not stuck. */
01784   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01785 
01786   /* Check if we were approaching a rail/road-crossing */
01787   TileIndex crossing = TrainApproachingCrossingTile(v);
01788 
01789   /* count number of vehicles */
01790   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01791 
01792   AdvanceWagonsBeforeSwap(v);
01793 
01794   /* swap start<>end, start+1<>end-1, ... */
01795   int l = 0;
01796   do {
01797     ReverseTrainSwapVeh(v, l++, r--);
01798   } while (l <= r);
01799 
01800   AdvanceWagonsAfterSwap(v);
01801 
01802   if (IsRailDepotTile(v->tile)) {
01803     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01804   }
01805 
01806   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01807 
01808   ClrBit(v->flags, VRF_REVERSING);
01809 
01810   /* recalculate cached data */
01811   v->ConsistChanged(true);
01812 
01813   /* update all images */
01814   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01815 
01816   /* update crossing we were approaching */
01817   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01818 
01819   /* maybe we are approaching crossing now, after reversal */
01820   crossing = TrainApproachingCrossingTile(v);
01821   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01822 
01823   /* If we are inside a depot after reversing, don't bother with path reserving. */
01824   if (v->track == TRACK_BIT_DEPOT) {
01825     /* Can't be stuck here as inside a depot is always a safe tile. */
01826     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01827     ClrBit(v->flags, VRF_TRAIN_STUCK);
01828     return;
01829   }
01830 
01831   /* TrainExitDir does not always produce the desired dir for depots and
01832    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01833   DiagDirection dir = TrainExitDir(v->direction, v->track);
01834   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01835 
01836   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01837     /* If we are currently on a tile with conventional signals, we can't treat the
01838      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01839     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01840       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01841       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01842 
01843     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01844     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01845 
01846     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01847     if (TryPathReserve(v, false, first_tile_okay)) {
01848       /* Do a look-ahead now in case our current tile was already a safe tile. */
01849       CheckNextTrainTile(v);
01850     } else if (v->current_order.GetType() != OT_LOADING) {
01851       /* Do not wait for a way out when we're still loading */
01852       MarkTrainAsStuck(v);
01853     }
01854   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01855     /* A train not inside a PBS block can't be stuck. */
01856     ClrBit(v->flags, VRF_TRAIN_STUCK);
01857     v->wait_counter = 0;
01858   }
01859 }
01860 
01870 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01871 {
01872   Train *v = Train::GetIfValid(p1);
01873   if (v == NULL) return CMD_ERROR;
01874 
01875   CommandCost ret = CheckOwnership(v->owner);
01876   if (ret.Failed()) return ret;
01877 
01878   if (p2 != 0) {
01879     /* turn a single unit around */
01880 
01881     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01882       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01883     }
01884     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01885 
01886     Train *front = v->First();
01887     /* make sure the vehicle is stopped in the depot */
01888     if (!front->IsStoppedInDepot()) {
01889       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01890     }
01891 
01892     if (flags & DC_EXEC) {
01893       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01894 
01895       front->ConsistChanged(false);
01896       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01897       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01898       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01899       SetWindowClassesDirty(WC_TRAINS_LIST);
01900     }
01901   } else {
01902     /* turn the whole train around */
01903     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01904 
01905     if (flags & DC_EXEC) {
01906       /* Properly leave the station if we are loading and won't be loading anymore */
01907       if (v->current_order.IsType(OT_LOADING)) {
01908         const Vehicle *last = v;
01909         while (last->Next() != NULL) last = last->Next();
01910 
01911         /* not a station || different station --> leave the station */
01912         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01913           v->LeaveStation();
01914         }
01915       }
01916 
01917       /* We cancel any 'skip signal at dangers' here */
01918       v->force_proceed = TFP_NONE;
01919       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01920 
01921       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01922         ToggleBit(v->flags, VRF_REVERSING);
01923       } else {
01924         v->cur_speed = 0;
01925         v->SetLastSpeed();
01926         HideFillingPercent(&v->fill_percent_te_id);
01927         ReverseTrainDirection(v);
01928       }
01929     }
01930   }
01931   return CommandCost();
01932 }
01933 
01943 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01944 {
01945   Train *t = Train::GetIfValid(p1);
01946   if (t == NULL) return CMD_ERROR;
01947 
01948   if (!t->IsPrimaryVehicle()) return CMD_ERROR;
01949 
01950   CommandCost ret = CheckOwnership(t->owner);
01951   if (ret.Failed()) return ret;
01952 
01953 
01954   if (flags & DC_EXEC) {
01955     /* If we are forced to proceed, cancel that order.
01956      * If we are marked stuck we would want to force the train
01957      * to proceed to the next signal. In the other cases we
01958      * would like to pass the signal at danger and run till the
01959      * next signal we encounter. */
01960     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsChainInDepot() ? TFP_STUCK : TFP_SIGNAL;
01961     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01962   }
01963 
01964   return CommandCost();
01965 }
01966 
01974 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01975 {
01976   assert(!(v->vehstatus & VS_CRASHED));
01977 
01978   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01979 
01980   PBSTileInfo origin = FollowTrainReservation(v);
01981   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01982 
01983   switch (_settings_game.pf.pathfinder_for_trains) {
01984     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01985     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01986 
01987     default: NOT_REACHED();
01988   }
01989 }
01990 
01998 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01999 {
02000   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
02001   if (tfdd.best_length == UINT_MAX) return false;
02002 
02003   if (location    != NULL) *location    = tfdd.tile;
02004   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
02005   if (reverse     != NULL) *reverse     = tfdd.reverse;
02006 
02007   return true;
02008 }
02009 
02011 void Train::PlayLeaveStationSound() const
02012 {
02013   static const SoundFx sfx[] = {
02014     SND_04_TRAIN,
02015     SND_0A_TRAIN_HORN,
02016     SND_0A_TRAIN_HORN,
02017     SND_47_MAGLEV_2,
02018     SND_41_MAGLEV
02019   };
02020 
02021   if (PlayVehicleSound(this, VSE_START)) return;
02022 
02023   EngineID engtype = this->engine_type;
02024   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02025 }
02026 
02031 static void CheckNextTrainTile(Train *v)
02032 {
02033   /* Don't do any look-ahead if path_backoff_interval is 255. */
02034   if (_settings_game.pf.path_backoff_interval == 255) return;
02035 
02036   /* Exit if we are inside a depot. */
02037   if (v->track == TRACK_BIT_DEPOT) return;
02038 
02039   switch (v->current_order.GetType()) {
02040     /* Exit if we reached our destination depot. */
02041     case OT_GOTO_DEPOT:
02042       if (v->tile == v->dest_tile) return;
02043       break;
02044 
02045     case OT_GOTO_WAYPOINT:
02046       /* If we reached our waypoint, make sure we see that. */
02047       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02048       break;
02049 
02050     case OT_NOTHING:
02051     case OT_LEAVESTATION:
02052     case OT_LOADING:
02053       /* Exit if the current order doesn't have a destination, but the train has orders. */
02054       if (v->GetNumOrders() > 0) return;
02055       break;
02056 
02057     default:
02058       break;
02059   }
02060   /* Exit if we are on a station tile and are going to stop. */
02061   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02062 
02063   Trackdir td = v->GetVehicleTrackdir();
02064 
02065   /* On a tile with a red non-pbs signal, don't look ahead. */
02066   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02067       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02068       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02069 
02070   CFollowTrackRail ft(v);
02071   if (!ft.Follow(v->tile, td)) return;
02072 
02073   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02074     /* Next tile is not reserved. */
02075     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02076       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02077         /* If the next tile is a PBS signal, try to make a reservation. */
02078         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02079         if (_settings_game.pf.forbid_90_deg) {
02080           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02081         }
02082         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02083       }
02084     }
02085   }
02086 }
02087 
02093 static bool CheckTrainStayInDepot(Train *v)
02094 {
02095   /* bail out if not all wagons are in the same depot or not in a depot at all */
02096   for (const Train *u = v; u != NULL; u = u->Next()) {
02097     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02098   }
02099 
02100   /* if the train got no power, then keep it in the depot */
02101   if (v->gcache.cached_power == 0) {
02102     v->vehstatus |= VS_STOPPED;
02103     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02104     return true;
02105   }
02106 
02107   SigSegState seg_state;
02108 
02109   if (v->force_proceed == TFP_NONE) {
02110     /* force proceed was not pressed */
02111     if (++v->wait_counter < 37) {
02112       SetWindowClassesDirty(WC_TRAINS_LIST);
02113       return true;
02114     }
02115 
02116     v->wait_counter = 0;
02117 
02118     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02119     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02120       /* Full and no PBS signal in block or depot reserved, can't exit. */
02121       SetWindowClassesDirty(WC_TRAINS_LIST);
02122       return true;
02123     }
02124   } else {
02125     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02126   }
02127 
02128   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02129   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02130     /* We need to have a reservation for this to work. */
02131     if (HasDepotReservation(v->tile)) return true;
02132     SetDepotReservation(v->tile, true);
02133     VehicleEnterDepot(v);
02134     return true;
02135   }
02136 
02137   /* Only leave when we can reserve a path to our destination. */
02138   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02139     /* No path and no force proceed. */
02140     SetWindowClassesDirty(WC_TRAINS_LIST);
02141     MarkTrainAsStuck(v);
02142     return true;
02143   }
02144 
02145   SetDepotReservation(v->tile, true);
02146   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02147 
02148   VehicleServiceInDepot(v);
02149   SetWindowClassesDirty(WC_TRAINS_LIST);
02150   v->PlayLeaveStationSound();
02151 
02152   v->track = TRACK_BIT_X;
02153   if (v->direction & 2) v->track = TRACK_BIT_Y;
02154 
02155   v->vehstatus &= ~VS_HIDDEN;
02156   v->cur_speed = 0;
02157 
02158   v->UpdateViewport(true, true);
02159   VehicleUpdatePosition(v);
02160   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02161   v->UpdateAcceleration();
02162   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02163 
02164   return false;
02165 }
02166 
02173 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02174 {
02175   DiagDirection dir = TrackdirToExitdir(track_dir);
02176 
02177   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02178     /* Are we just leaving a tunnel/bridge? */
02179     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02180       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02181 
02182       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02183         /* Free the reservation only if no other train is on the tiles. */
02184         SetTunnelBridgeReservation(tile, false);
02185         SetTunnelBridgeReservation(end, false);
02186 
02187         if (_settings_client.gui.show_track_reservation) {
02188           MarkTileDirtyByTile(tile);
02189           MarkTileDirtyByTile(end);
02190         }
02191       }
02192     }
02193   } else if (IsRailStationTile(tile)) {
02194     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02195     /* If the new tile is not a further tile of the same station, we
02196      * clear the reservation for the whole platform. */
02197     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02198       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02199     }
02200   } else {
02201     /* Any other tile */
02202     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02203   }
02204 }
02205 
02212 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02213 {
02214   assert(v->IsFrontEngine());
02215 
02216   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02217   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02218   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02219   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02220 
02221   /* Can't be holding a reservation if we enter a depot. */
02222   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02223   if (v->track == TRACK_BIT_DEPOT) {
02224     /* Front engine is in a depot. We enter if some part is not in the depot. */
02225     for (const Train *u = v; u != NULL; u = u->Next()) {
02226       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02227     }
02228   }
02229   /* Don't free reservation if it's not ours. */
02230   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02231 
02232   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02233   while (ft.Follow(tile, td)) {
02234     tile = ft.m_new_tile;
02235     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02236     td = RemoveFirstTrackdir(&bits);
02237     assert(bits == TRACKDIR_BIT_NONE);
02238 
02239     if (!IsValidTrackdir(td)) break;
02240 
02241     if (IsTileType(tile, MP_RAILWAY)) {
02242       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02243         /* Conventional signal along trackdir: remove reservation and stop. */
02244         UnreserveRailTrack(tile, TrackdirToTrack(td));
02245         break;
02246       }
02247       if (HasPbsSignalOnTrackdir(tile, td)) {
02248         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02249           /* Red PBS signal? Can't be our reservation, would be green then. */
02250           break;
02251         } else {
02252           /* Turn the signal back to red. */
02253           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02254           MarkTileDirtyByTile(tile);
02255         }
02256       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02257         break;
02258       }
02259     }
02260 
02261     /* Don't free first station/bridge/tunnel if we are on it. */
02262     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);
02263 
02264     free_tile = true;
02265   }
02266 }
02267 
02268 static const byte _initial_tile_subcoord[6][4][3] = {
02269 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02270 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02271 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02272 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02273 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02274 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02275 };
02276 
02289 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02290 {
02291   switch (_settings_game.pf.pathfinder_for_trains) {
02292     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02293     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02294 
02295     default: NOT_REACHED();
02296   }
02297 }
02298 
02304 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02305 {
02306   PBSTileInfo origin = FollowTrainReservation(v);
02307 
02308   CFollowTrackRail ft(v);
02309 
02310   TileIndex tile = origin.tile;
02311   Trackdir  cur_td = origin.trackdir;
02312   while (ft.Follow(tile, cur_td)) {
02313     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02314       /* Possible signal tile. */
02315       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02316     }
02317 
02318     if (_settings_game.pf.forbid_90_deg) {
02319       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02320       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02321     }
02322 
02323     /* Station, depot or waypoint are a possible target. */
02324     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02325     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02326       /* Choice found or possible target encountered.
02327        * On finding a possible target, we need to stop and let the pathfinder handle the
02328        * remaining path. This is because we don't know if this target is in one of our
02329        * orders, so we might cause pathfinding to fail later on if we find a choice.
02330        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02331        * a wrong path not leading to our next destination. */
02332       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02333 
02334       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02335        * actually starts its search at the first unreserved tile. */
02336       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02337 
02338       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02339       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02340       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02341       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02342     }
02343 
02344     tile = ft.m_new_tile;
02345     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02346 
02347     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02348       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02349       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02350       /* Safe position is all good, path valid and okay. */
02351       return PBSTileInfo(tile, cur_td, true);
02352     }
02353 
02354     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02355   }
02356 
02357   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02358     /* End of line, path valid and okay. */
02359     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02360   }
02361 
02362   /* Sorry, can't reserve path, back out. */
02363   tile = origin.tile;
02364   cur_td = origin.trackdir;
02365   TileIndex stopped = ft.m_old_tile;
02366   Trackdir  stopped_td = ft.m_old_td;
02367   while (tile != stopped || cur_td != stopped_td) {
02368     if (!ft.Follow(tile, cur_td)) break;
02369 
02370     if (_settings_game.pf.forbid_90_deg) {
02371       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02372       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02373     }
02374     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02375 
02376     tile = ft.m_new_tile;
02377     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02378 
02379     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02380   }
02381 
02382   /* Path invalid. */
02383   return PBSTileInfo();
02384 }
02385 
02396 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02397 {
02398   switch (_settings_game.pf.pathfinder_for_trains) {
02399     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02400     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02401 
02402     default: NOT_REACHED();
02403   }
02404 }
02405 
02407 class VehicleOrderSaver {
02408 private:
02409   Train          *v;
02410   Order          old_order;
02411   TileIndex      old_dest_tile;
02412   StationID      old_last_station_visited;
02413   VehicleOrderID index;
02414   bool           suppress_implicit_orders;
02415 
02416 public:
02417   VehicleOrderSaver(Train *_v) :
02418     v(_v),
02419     old_order(_v->current_order),
02420     old_dest_tile(_v->dest_tile),
02421     old_last_station_visited(_v->last_station_visited),
02422     index(_v->cur_real_order_index),
02423     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02424   {
02425   }
02426 
02427   ~VehicleOrderSaver()
02428   {
02429     this->v->current_order = this->old_order;
02430     this->v->dest_tile = this->old_dest_tile;
02431     this->v->last_station_visited = this->old_last_station_visited;
02432     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02433   }
02434 
02440   bool SwitchToNextOrder(bool skip_first)
02441   {
02442     if (this->v->GetNumOrders() == 0) return false;
02443 
02444     if (skip_first) ++this->index;
02445 
02446     int depth = 0;
02447 
02448     do {
02449       /* Wrap around. */
02450       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02451 
02452       Order *order = this->v->GetOrder(this->index);
02453       assert(order != NULL);
02454 
02455       switch (order->GetType()) {
02456         case OT_GOTO_DEPOT:
02457           /* Skip service in depot orders when the train doesn't need service. */
02458           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02459         case OT_GOTO_STATION:
02460         case OT_GOTO_WAYPOINT:
02461           this->v->current_order = *order;
02462           return UpdateOrderDest(this->v, order, 0, true);
02463         case OT_CONDITIONAL: {
02464           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02465           if (next != INVALID_VEH_ORDER_ID) {
02466             depth++;
02467             this->index = next;
02468             /* Don't increment next, so no break here. */
02469             continue;
02470           }
02471           break;
02472         }
02473         default:
02474           break;
02475       }
02476       /* Don't increment inside the while because otherwise conditional
02477        * orders can lead to an infinite loop. */
02478       ++this->index;
02479       depth++;
02480     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02481 
02482     return false;
02483   }
02484 };
02485 
02486 /* choose a track */
02487 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02488 {
02489   Track best_track = INVALID_TRACK;
02490   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02491   bool changed_signal = false;
02492 
02493   assert((tracks & ~TRACK_BIT_MASK) == 0);
02494 
02495   if (got_reservation != NULL) *got_reservation = false;
02496 
02497   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02498   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02499   /* Do we have a suitable reserved track? */
02500   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02501 
02502   /* Quick return in case only one possible track is available */
02503   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02504     Track track = FindFirstTrack(tracks);
02505     /* We need to check for signals only here, as a junction tile can't have signals. */
02506     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02507       do_track_reservation = true;
02508       changed_signal = true;
02509       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02510     } else if (!do_track_reservation) {
02511       return track;
02512     }
02513     best_track = track;
02514   }
02515 
02516   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02517   DiagDirection dest_enterdir = enterdir;
02518   if (do_track_reservation) {
02519     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02520     if (res_dest.tile == INVALID_TILE) {
02521       /* Reservation failed? */
02522       if (mark_stuck) MarkTrainAsStuck(v);
02523       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02524       return FindFirstTrack(tracks);
02525     }
02526     if (res_dest.okay) {
02527       /* Got a valid reservation that ends at a safe target, quick exit. */
02528       if (got_reservation != NULL) *got_reservation = true;
02529       if (changed_signal) MarkTileDirtyByTile(tile);
02530       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02531       return best_track;
02532     }
02533 
02534     /* Check if the train needs service here, so it has a chance to always find a depot.
02535      * Also check if the current order is a service order so we don't reserve a path to
02536      * the destination but instead to the next one if service isn't needed. */
02537     CheckIfTrainNeedsService(v);
02538     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02539   }
02540 
02541   /* Save the current train order. The destructor will restore the old order on function exit. */
02542   VehicleOrderSaver orders(v);
02543 
02544   /* If the current tile is the destination of the current order and
02545    * a reservation was requested, advance to the next order.
02546    * Don't advance on a depot order as depots are always safe end points
02547    * for a path and no look-ahead is necessary. This also avoids a
02548    * problem with depot orders not part of the order list when the
02549    * order list itself is empty. */
02550   if (v->current_order.IsType(OT_LEAVESTATION)) {
02551     orders.SwitchToNextOrder(false);
02552   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02553       v->current_order.IsType(OT_GOTO_STATION) ?
02554       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02555       v->tile == v->dest_tile))) {
02556     orders.SwitchToNextOrder(true);
02557   }
02558 
02559   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02560     /* Pathfinders are able to tell that route was only 'guessed'. */
02561     bool      path_found = true;
02562     TileIndex new_tile = res_dest.tile;
02563 
02564     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02565     if (new_tile == tile) best_track = next_track;
02566     v->HandlePathfindingResult(path_found);
02567   }
02568 
02569   /* No track reservation requested -> finished. */
02570   if (!do_track_reservation) return best_track;
02571 
02572   /* A path was found, but could not be reserved. */
02573   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02574     if (mark_stuck) MarkTrainAsStuck(v);
02575     FreeTrainTrackReservation(v);
02576     return best_track;
02577   }
02578 
02579   /* No possible reservation target found, we are probably lost. */
02580   if (res_dest.tile == INVALID_TILE) {
02581     /* Try to find any safe destination. */
02582     PBSTileInfo origin = FollowTrainReservation(v);
02583     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02584       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02585       best_track = FindFirstTrack(res);
02586       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02587       if (got_reservation != NULL) *got_reservation = true;
02588       if (changed_signal) MarkTileDirtyByTile(tile);
02589     } else {
02590       FreeTrainTrackReservation(v);
02591       if (mark_stuck) MarkTrainAsStuck(v);
02592     }
02593     return best_track;
02594   }
02595 
02596   if (got_reservation != NULL) *got_reservation = true;
02597 
02598   /* Reservation target found and free, check if it is safe. */
02599   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02600     /* Extend reservation until we have found a safe position. */
02601     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02602     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02603     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02604     if (_settings_game.pf.forbid_90_deg) {
02605       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02606     }
02607 
02608     /* Get next order with destination. */
02609     if (orders.SwitchToNextOrder(true)) {
02610       PBSTileInfo cur_dest;
02611       bool path_found;
02612       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02613       if (cur_dest.tile != INVALID_TILE) {
02614         res_dest = cur_dest;
02615         if (res_dest.okay) continue;
02616         /* Path found, but could not be reserved. */
02617         FreeTrainTrackReservation(v);
02618         if (mark_stuck) MarkTrainAsStuck(v);
02619         if (got_reservation != NULL) *got_reservation = false;
02620         changed_signal = false;
02621         break;
02622       }
02623     }
02624     /* No order or no safe position found, try any position. */
02625     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02626       FreeTrainTrackReservation(v);
02627       if (mark_stuck) MarkTrainAsStuck(v);
02628       if (got_reservation != NULL) *got_reservation = false;
02629       changed_signal = false;
02630     }
02631     break;
02632   }
02633 
02634   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02635 
02636   if (changed_signal) MarkTileDirtyByTile(tile);
02637 
02638   return best_track;
02639 }
02640 
02649 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02650 {
02651   assert(v->IsFrontEngine());
02652 
02653   /* We have to handle depots specially as the track follower won't look
02654    * at the depot tile itself but starts from the next tile. If we are still
02655    * inside the depot, a depot reservation can never be ours. */
02656   if (v->track == TRACK_BIT_DEPOT) {
02657     if (HasDepotReservation(v->tile)) {
02658       if (mark_as_stuck) MarkTrainAsStuck(v);
02659       return false;
02660     } else {
02661       /* Depot not reserved, but the next tile might be. */
02662       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02663       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02664     }
02665   }
02666 
02667   Vehicle *other_train = NULL;
02668   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02669   /* The path we are driving on is already blocked by some other train.
02670    * This can only happen in certain situations when mixing path and
02671    * block signals or when changing tracks and/or signals.
02672    * Exit here as doing any further reservations will probably just
02673    * make matters worse. */
02674   if (other_train != NULL && other_train->index != v->index) {
02675     if (mark_as_stuck) MarkTrainAsStuck(v);
02676     return false;
02677   }
02678   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02679   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02680     /* Can't be stuck then. */
02681     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02682     ClrBit(v->flags, VRF_TRAIN_STUCK);
02683     return true;
02684   }
02685 
02686   /* If we are in a depot, tentatively reserve the depot. */
02687   if (v->track == TRACK_BIT_DEPOT) {
02688     SetDepotReservation(v->tile, true);
02689     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02690   }
02691 
02692   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02693   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02694   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02695 
02696   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02697 
02698   bool res_made = false;
02699   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02700 
02701   if (!res_made) {
02702     /* Free the depot reservation as well. */
02703     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02704     return false;
02705   }
02706 
02707   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02708     v->wait_counter = 0;
02709     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02710   }
02711   ClrBit(v->flags, VRF_TRAIN_STUCK);
02712   return true;
02713 }
02714 
02715 
02716 static bool CheckReverseTrain(const Train *v)
02717 {
02718   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02719       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02720       !(v->direction & 1)) {
02721     return false;
02722   }
02723 
02724   assert(v->track != TRACK_BIT_NONE);
02725 
02726   switch (_settings_game.pf.pathfinder_for_trains) {
02727     case VPF_NPF: return NPFTrainCheckReverse(v);
02728     case VPF_YAPF: return YapfTrainCheckReverse(v);
02729 
02730     default: NOT_REACHED();
02731   }
02732 }
02733 
02739 TileIndex Train::GetOrderStationLocation(StationID station)
02740 {
02741   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02742 
02743   const Station *st = Station::Get(station);
02744   if (!(st->facilities & FACIL_TRAIN)) {
02745     /* The destination station has no trainstation tiles. */
02746     this->IncrementRealOrderIndex();
02747     return 0;
02748   }
02749 
02750   return st->xy;
02751 }
02752 
02754 void Train::MarkDirty()
02755 {
02756   Train *v = this;
02757   do {
02758     v->UpdateViewport(false, false);
02759   } while ((v = v->Next()) != NULL);
02760 
02761   /* need to update acceleration and cached values since the goods on the train changed. */
02762   this->CargoChanged();
02763   this->UpdateAcceleration();
02764 }
02765 
02773 int Train::UpdateSpeed()
02774 {
02775   switch (_settings_game.vehicle.train_acceleration_model) {
02776     default: NOT_REACHED();
02777     case AM_ORIGINAL:
02778       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, min(this->gcache.cached_max_track_speed, this->current_order.max_speed));
02779 
02780     case AM_REALISTIC:
02781       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02782   }
02783 }
02784 
02790 static void TrainEnterStation(Train *v, StationID station)
02791 {
02792   v->last_station_visited = station;
02793 
02794   /* check if a train ever visited this station before */
02795   Station *st = Station::Get(station);
02796   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02797     st->had_vehicle_of_type |= HVOT_TRAIN;
02798     SetDParam(0, st->index);
02799     AddVehicleNewsItem(
02800       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02801       v->owner == _local_company ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
02802       v->index,
02803       st->index
02804     );
02805     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02806     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02807   }
02808 
02809   v->force_proceed = TFP_NONE;
02810   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02811 
02812   v->BeginLoading();
02813 
02814   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02815 }
02816 
02817 /* Check if the vehicle is compatible with the specified tile */
02818 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02819 {
02820   return IsTileOwner(tile, v->owner) &&
02821       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02822 }
02823 
02825 struct AccelerationSlowdownParams {
02826   byte small_turn; 
02827   byte large_turn; 
02828   byte z_up;       
02829   byte z_down;     
02830 };
02831 
02833 static const AccelerationSlowdownParams _accel_slowdown[] = {
02834   /* normal accel */
02835   {256 / 4, 256 / 2, 256 / 4, 2}, 
02836   {256 / 4, 256 / 2, 256 / 4, 2}, 
02837   {0,       256 / 2, 256 / 4, 2}, 
02838 };
02839 
02845 static inline void AffectSpeedByZChange(Train *v, int old_z)
02846 {
02847   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02848 
02849   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02850 
02851   if (old_z < v->z_pos) {
02852     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02853   } else {
02854     uint16 spd = v->cur_speed + asp->z_down;
02855     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02856   }
02857 }
02858 
02859 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02860 {
02861   if (IsTileType(tile, MP_RAILWAY) &&
02862       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02863     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02864     Trackdir trackdir = FindFirstTrackdir(tracks);
02865     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02866       /* A PBS block with a non-PBS signal facing us? */
02867       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02868     }
02869   }
02870   return false;
02871 }
02872 
02874 void Train::ReserveTrackUnderConsist() const
02875 {
02876   for (const Train *u = this; u != NULL; u = u->Next()) {
02877     switch (u->track) {
02878       case TRACK_BIT_WORMHOLE:
02879         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02880         break;
02881       case TRACK_BIT_DEPOT:
02882         break;
02883       default:
02884         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02885         break;
02886     }
02887   }
02888 }
02889 
02896 uint Train::Crash(bool flooded)
02897 {
02898   uint pass = 0;
02899   if (this->IsFrontEngine()) {
02900     pass += 2; // driver
02901 
02902     /* Remove the reserved path in front of the train if it is not stuck.
02903      * Also clear all reserved tracks the train is currently on. */
02904     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02905     for (const Train *v = this; v != NULL; v = v->Next()) {
02906       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02907       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02908         /* ClearPathReservation will not free the wormhole exit
02909          * if the train has just entered the wormhole. */
02910         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02911       }
02912     }
02913 
02914     /* we may need to update crossing we were approaching,
02915      * but must be updated after the train has been marked crashed */
02916     TileIndex crossing = TrainApproachingCrossingTile(this);
02917     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02918 
02919     /* Remove the loading indicators (if any) */
02920     HideFillingPercent(&this->fill_percent_te_id);
02921   }
02922 
02923   pass += this->GroundVehicleBase::Crash(flooded);
02924 
02925   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02926   return pass;
02927 }
02928 
02935 static uint TrainCrashed(Train *v)
02936 {
02937   uint num = 0;
02938 
02939   /* do not crash train twice */
02940   if (!(v->vehstatus & VS_CRASHED)) {
02941     num = v->Crash();
02942     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02943     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02944   }
02945 
02946   /* Try to re-reserve track under already crashed train too.
02947    * Crash() clears the reservation! */
02948   v->ReserveTrackUnderConsist();
02949 
02950   return num;
02951 }
02952 
02954 struct TrainCollideChecker {
02955   Train *v; 
02956   uint num; 
02957 };
02958 
02965 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02966 {
02967   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02968 
02969   /* not a train or in depot */
02970   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02971 
02972   /* do not crash into trains of another company. */
02973   if (v->owner != tcc->v->owner) return NULL;
02974 
02975   /* get first vehicle now to make most usual checks faster */
02976   Train *coll = Train::From(v)->First();
02977 
02978   /* can't collide with own wagons */
02979   if (coll == tcc->v) return NULL;
02980 
02981   int x_diff = v->x_pos - tcc->v->x_pos;
02982   int y_diff = v->y_pos - tcc->v->y_pos;
02983 
02984   /* Do fast calculation to check whether trains are not in close vicinity
02985    * and quickly reject trains distant enough for any collision.
02986    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02987    * Differences are then ORed and then we check for any higher bits */
02988   uint hash = (y_diff + 7) | (x_diff + 7);
02989   if (hash & ~15) return NULL;
02990 
02991   /* Slower check using multiplication */
02992   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02993   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02994 
02995   /* Happens when there is a train under bridge next to bridge head */
02996   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02997 
02998   /* crash both trains */
02999   tcc->num += TrainCrashed(tcc->v);
03000   tcc->num += TrainCrashed(coll);
03001 
03002   return NULL; // continue searching
03003 }
03004 
03012 static bool CheckTrainCollision(Train *v)
03013 {
03014   /* can't collide in depot */
03015   if (v->track == TRACK_BIT_DEPOT) return false;
03016 
03017   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03018 
03019   TrainCollideChecker tcc;
03020   tcc.v = v;
03021   tcc.num = 0;
03022 
03023   /* find colliding vehicles */
03024   if (v->track == TRACK_BIT_WORMHOLE) {
03025     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03026     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03027   } else {
03028     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03029   }
03030 
03031   /* any dead -> no crash */
03032   if (tcc.num == 0) return false;
03033 
03034   SetDParam(0, tcc.num);
03035   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH, NT_ACCIDENT, v->index);
03036 
03037   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03038   if (_settings_client.sound.disaster) SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03039   return true;
03040 }
03041 
03042 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03043 {
03044   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03045 
03046   Train *t = Train::From(v);
03047   DiagDirection exitdir = *(DiagDirection *)data;
03048 
03049   /* not front engine of a train, inside wormhole or depot, crashed */
03050   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03051 
03052   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03053 
03054   return t;
03055 }
03056 
03064 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03065 {
03066   Train *first = v->First();
03067   Train *prev;
03068   bool direction_changed = false; // has direction of any part changed?
03069 
03070   /* For every vehicle after and including the given vehicle */
03071   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03072     DiagDirection enterdir = DIAGDIR_BEGIN;
03073     bool update_signals_crossing = false; // will we update signals or crossing state?
03074 
03075     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03076     if (v->track != TRACK_BIT_WORMHOLE) {
03077       /* Not inside tunnel */
03078       if (gp.old_tile == gp.new_tile) {
03079         /* Staying in the old tile */
03080         if (v->track == TRACK_BIT_DEPOT) {
03081           /* Inside depot */
03082           gp.x = v->x_pos;
03083           gp.y = v->y_pos;
03084         } else {
03085           /* Not inside depot */
03086 
03087           /* Reverse when we are at the end of the track already, do not move to the new position */
03088           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03089 
03090           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03091           if (HasBit(r, VETS_CANNOT_ENTER)) {
03092             goto invalid_rail;
03093           }
03094           if (HasBit(r, VETS_ENTERED_STATION)) {
03095             /* The new position is the end of the platform */
03096             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03097           }
03098         }
03099       } else {
03100         /* A new tile is about to be entered. */
03101 
03102         /* Determine what direction we're entering the new tile from */
03103         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03104         assert(IsValidDiagDirection(enterdir));
03105 
03106         /* Get the status of the tracks in the new tile and mask
03107          * away the bits that aren't reachable. */
03108         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03109         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03110 
03111         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03112         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03113 
03114         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03115         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03116           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03117            * can be switched on halfway a turn */
03118           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03119         }
03120 
03121         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03122 
03123         /* Check if the new tile constrains tracks that are compatible
03124          * with the current train, if not, bail out. */
03125         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03126 
03127         TrackBits chosen_track;
03128         if (prev == NULL) {
03129           /* Currently the locomotive is active. Determine which one of the
03130            * available tracks to choose */
03131           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03132           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03133 
03134           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03135             /* For each signal we find decrease the counter by one.
03136              * We start at two, so the first signal we pass decreases
03137              * this to one, then if we reach the next signal it is
03138              * decreased to zero and we won't pass that new signal. */
03139             Trackdir dir = FindFirstTrackdir(trackdirbits);
03140             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03141                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03142               /* However, we do not want to be stopped by PBS signals
03143                * entered via the back. */
03144               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03145               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03146             }
03147           }
03148 
03149           /* Check if it's a red signal and that force proceed is not clicked. */
03150           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03151             /* In front of a red signal */
03152             Trackdir i = FindFirstTrackdir(trackdirbits);
03153 
03154             /* Don't handle stuck trains here. */
03155             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03156 
03157             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03158               v->cur_speed = 0;
03159               v->subspeed = 0;
03160               v->progress = 255 - 100;
03161               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03162             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03163               v->cur_speed = 0;
03164               v->subspeed = 0;
03165               v->progress = 255 - 10;
03166               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03167                 DiagDirection exitdir = TrackdirToExitdir(i);
03168                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03169 
03170                 exitdir = ReverseDiagDir(exitdir);
03171 
03172                 /* check if a train is waiting on the other side */
03173                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03174               }
03175             }
03176 
03177             /* If we would reverse but are currently in a PBS block and
03178              * reversing of stuck trains is disabled, don't reverse.
03179              * This does not apply if the reason for reversing is a one-way
03180              * signal blocking us, because a train would then be stuck forever. */
03181             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03182                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03183               v->wait_counter = 0;
03184               return false;
03185             }
03186             goto reverse_train_direction;
03187           } else {
03188             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03189           }
03190         } else {
03191           /* The wagon is active, simply follow the prev vehicle. */
03192           if (prev->tile == gp.new_tile) {
03193             /* Choose the same track as prev */
03194             if (prev->track == TRACK_BIT_WORMHOLE) {
03195               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03196                * However, just choose the track into the wormhole. */
03197               assert(IsTunnel(prev->tile));
03198               chosen_track = bits;
03199             } else {
03200               chosen_track = prev->track;
03201             }
03202           } else {
03203             /* Choose the track that leads to the tile where prev is.
03204              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03205              * I.e. when the tile between them has only space for a single vehicle like
03206              *  1) horizontal/vertical track tiles and
03207              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03208              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03209              */
03210             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03211               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03212               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03213               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03214               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03215             };
03216             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03217             assert(IsValidDiagDirection(exitdir));
03218             chosen_track = _connecting_track[enterdir][exitdir];
03219           }
03220           chosen_track &= bits;
03221         }
03222 
03223         /* Make sure chosen track is a valid track */
03224         assert(
03225             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03226             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03227             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03228 
03229         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03230         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03231         gp.x = (gp.x & ~0xF) | b[0];
03232         gp.y = (gp.y & ~0xF) | b[1];
03233         Direction chosen_dir = (Direction)b[2];
03234 
03235         /* Call the landscape function and tell it that the vehicle entered the tile */
03236         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03237         if (HasBit(r, VETS_CANNOT_ENTER)) {
03238           goto invalid_rail;
03239         }
03240 
03241         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03242           Track track = FindFirstTrack(chosen_track);
03243           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03244           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03245             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03246             MarkTileDirtyByTile(gp.new_tile);
03247           }
03248 
03249           /* Clear any track reservation when the last vehicle leaves the tile */
03250           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03251 
03252           v->tile = gp.new_tile;
03253 
03254           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03255             v->First()->ConsistChanged(true);
03256           }
03257 
03258           v->track = chosen_track;
03259           assert(v->track);
03260         }
03261 
03262         /* We need to update signal status, but after the vehicle position hash
03263          * has been updated by UpdateInclination() */
03264         update_signals_crossing = true;
03265 
03266         if (chosen_dir != v->direction) {
03267           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03268             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03269             DirDiff diff = DirDifference(v->direction, chosen_dir);
03270             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03271           }
03272           direction_changed = true;
03273           v->direction = chosen_dir;
03274         }
03275 
03276         if (v->IsFrontEngine()) {
03277           v->wait_counter = 0;
03278 
03279           /* If we are approaching a crossing that is reserved, play the sound now. */
03280           TileIndex crossing = TrainApproachingCrossingTile(v);
03281           if (crossing != INVALID_TILE && HasCrossingReservation(crossing) && _settings_client.sound.new_year) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03282 
03283           /* Always try to extend the reservation when entering a tile. */
03284           CheckNextTrainTile(v);
03285         }
03286 
03287         if (HasBit(r, VETS_ENTERED_STATION)) {
03288           /* The new position is the location where we want to stop */
03289           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03290         }
03291       }
03292     } else {
03293       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03294         /* Perform look-ahead on tunnel exit. */
03295         if (v->IsFrontEngine()) {
03296           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03297           CheckNextTrainTile(v);
03298         }
03299         /* Prevent v->UpdateInclination() being called with wrong parameters.
03300          * This could happen if the train was reversed inside the tunnel/bridge. */
03301         if (gp.old_tile == gp.new_tile) {
03302           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03303         }
03304       } else {
03305         v->x_pos = gp.x;
03306         v->y_pos = gp.y;
03307         VehicleUpdatePosition(v);
03308         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03309         continue;
03310       }
03311     }
03312 
03313     /* update image of train, as well as delta XY */
03314     v->UpdateDeltaXY(v->direction);
03315 
03316     v->x_pos = gp.x;
03317     v->y_pos = gp.y;
03318     VehicleUpdatePosition(v);
03319 
03320     /* update the Z position of the vehicle */
03321     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03322 
03323     if (prev == NULL) {
03324       /* This is the first vehicle in the train */
03325       AffectSpeedByZChange(v, old_z);
03326     }
03327 
03328     if (update_signals_crossing) {
03329       if (v->IsFrontEngine()) {
03330         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03331           /* We are entering a block with PBS signals right now, but
03332            * not through a PBS signal. This means we don't have a
03333            * reservation right now. As a conventional signal will only
03334            * ever be green if no other train is in the block, getting
03335            * a path should always be possible. If the player built
03336            * such a strange network that it is not possible, the train
03337            * will be marked as stuck and the player has to deal with
03338            * the problem. */
03339           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03340               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03341               !TryPathReserve(v)) {
03342             MarkTrainAsStuck(v);
03343           }
03344         }
03345       }
03346 
03347       /* Signals can only change when the first
03348        * (above) or the last vehicle moves. */
03349       if (v->Next() == NULL) {
03350         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03351         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03352       }
03353     }
03354 
03355     /* Do not check on every tick to save some computing time. */
03356     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03357   }
03358 
03359   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03360 
03361   return true;
03362 
03363 invalid_rail:
03364   /* We've reached end of line?? */
03365   if (prev != NULL) error("Disconnecting train");
03366 
03367 reverse_train_direction:
03368   if (reverse) {
03369     v->wait_counter = 0;
03370     v->cur_speed = 0;
03371     v->subspeed = 0;
03372     ReverseTrainDirection(v);
03373   }
03374 
03375   return false;
03376 }
03377 
03384 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03385 {
03386   TrackBits *trackbits = (TrackBits *)data;
03387 
03388   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03389     TrackBits train_tbits = Train::From(v)->track;
03390     if (train_tbits == TRACK_BIT_WORMHOLE) {
03391       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03392       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03393     } else if (train_tbits != TRACK_BIT_DEPOT) {
03394       *trackbits |= train_tbits;
03395     }
03396   }
03397 
03398   return NULL;
03399 }
03400 
03408 static void DeleteLastWagon(Train *v)
03409 {
03410   Train *first = v->First();
03411 
03412   /* Go to the last wagon and delete the link pointing there
03413    * *u is then the one-before-last wagon, and *v the last
03414    * one which will physically be removed */
03415   Train *u = v;
03416   for (; v->Next() != NULL; v = v->Next()) u = v;
03417   u->SetNext(NULL);
03418 
03419   if (first != v) {
03420     /* Recalculate cached train properties */
03421     first->ConsistChanged(false);
03422     /* Update the depot window if the first vehicle is in depot -
03423      * if v == first, then it is updated in PreDestructor() */
03424     if (first->track == TRACK_BIT_DEPOT) {
03425       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03426     }
03427   }
03428 
03429   /* 'v' shouldn't be accessed after it has been deleted */
03430   TrackBits trackbits = v->track;
03431   TileIndex tile = v->tile;
03432   Owner owner = v->owner;
03433 
03434   delete v;
03435   v = NULL; // make sure nobody will try to read 'v' anymore
03436 
03437   if (trackbits == TRACK_BIT_WORMHOLE) {
03438     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03439     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03440   }
03441 
03442   Track track = TrackBitsToTrack(trackbits);
03443   if (HasReservedTracks(tile, trackbits)) {
03444     UnreserveRailTrack(tile, track);
03445 
03446     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03447     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03448     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03449 
03450     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03451     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03452     Track t;
03453     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03454   }
03455 
03456   /* check if the wagon was on a road/rail-crossing */
03457   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03458 
03459   /* Update signals */
03460   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03461     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03462   } else {
03463     SetSignalsOnBothDir(tile, track, owner);
03464   }
03465 }
03466 
03471 static void ChangeTrainDirRandomly(Train *v)
03472 {
03473   static const DirDiff delta[] = {
03474     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03475   };
03476 
03477   do {
03478     /* We don't need to twist around vehicles if they're not visible */
03479     if (!(v->vehstatus & VS_HIDDEN)) {
03480       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03481       v->UpdateDeltaXY(v->direction);
03482       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03483       /* Refrain from updating the z position of the vehicle when on
03484        * a bridge, because UpdateInclination() will put the vehicle under
03485        * the bridge in that case */
03486       if (v->track != TRACK_BIT_WORMHOLE) {
03487         VehicleUpdatePosition(v);
03488         v->UpdateInclination(false, false);
03489       }
03490     }
03491   } while ((v = v->Next()) != NULL);
03492 }
03493 
03499 static bool HandleCrashedTrain(Train *v)
03500 {
03501   int state = ++v->crash_anim_pos;
03502 
03503   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03504     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03505   }
03506 
03507   uint32 r;
03508   if (state <= 200 && Chance16R(1, 7, r)) {
03509     int index = (r * 10 >> 16);
03510 
03511     Vehicle *u = v;
03512     do {
03513       if (--index < 0) {
03514         r = Random();
03515 
03516         CreateEffectVehicleRel(u,
03517           GB(r,  8, 3) + 2,
03518           GB(r, 16, 3) + 2,
03519           GB(r,  0, 3) + 5,
03520           EV_EXPLOSION_SMALL);
03521         break;
03522       }
03523     } while ((u = u->Next()) != NULL);
03524   }
03525 
03526   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03527 
03528   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03529     bool ret = v->Next() != NULL;
03530     DeleteLastWagon(v);
03531     return ret;
03532   }
03533 
03534   return true;
03535 }
03536 
03538 static const uint16 _breakdown_speeds[16] = {
03539   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03540 };
03541 
03542 
03551 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03552 {
03553   /* Calc position within the current tile */
03554   uint x = v->x_pos & 0xF;
03555   uint y = v->y_pos & 0xF;
03556 
03557   /* for diagonal directions, 'x' will be 0..15 -
03558    * for other directions, it will be 1, 3, 5, ..., 15 */
03559   switch (v->direction) {
03560     case DIR_N : x = ~x + ~y + 25; break;
03561     case DIR_NW: x = y;            // FALL THROUGH
03562     case DIR_NE: x = ~x + 16;      break;
03563     case DIR_E : x = ~x + y + 9;   break;
03564     case DIR_SE: x = y;            break;
03565     case DIR_S : x = x + y - 7;    break;
03566     case DIR_W : x = ~y + x + 9;   break;
03567     default: break;
03568   }
03569 
03570   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03571    * does not cross the tile boundary when we do reverse, but as the vehicle's
03572    * location is based on their center, use half a vehicle's length as offset.
03573    * Multiply the half-length by two for straight directions to compensate that
03574    * we only get odd x offsets there. */
03575   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03576     /* we are too near the tile end, reverse now */
03577     v->cur_speed = 0;
03578     if (reverse) ReverseTrainDirection(v);
03579     return false;
03580   }
03581 
03582   /* slow down */
03583   v->vehstatus |= VS_TRAIN_SLOWING;
03584   uint16 break_speed = _breakdown_speeds[x & 0xF];
03585   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03586 
03587   return true;
03588 }
03589 
03590 
03596 static bool TrainCanLeaveTile(const Train *v)
03597 {
03598   /* Exit if inside a tunnel/bridge or a depot */
03599   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03600 
03601   TileIndex tile = v->tile;
03602 
03603   /* entering a tunnel/bridge? */
03604   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03605     DiagDirection dir = GetTunnelBridgeDirection(tile);
03606     if (DiagDirToDir(dir) == v->direction) return false;
03607   }
03608 
03609   /* entering a depot? */
03610   if (IsRailDepotTile(tile)) {
03611     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03612     if (DiagDirToDir(dir) == v->direction) return false;
03613   }
03614 
03615   return true;
03616 }
03617 
03618 
03626 static TileIndex TrainApproachingCrossingTile(const Train *v)
03627 {
03628   assert(v->IsFrontEngine());
03629   assert(!(v->vehstatus & VS_CRASHED));
03630 
03631   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03632 
03633   DiagDirection dir = TrainExitDir(v->direction, v->track);
03634   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03635 
03636   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03637   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03638       !CheckCompatibleRail(v, tile)) {
03639     return INVALID_TILE;
03640   }
03641 
03642   return tile;
03643 }
03644 
03645 
03653 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03654 {
03655   /* First, handle broken down train */
03656 
03657   int t = v->breakdown_ctr;
03658   if (t > 1) {
03659     v->vehstatus |= VS_TRAIN_SLOWING;
03660 
03661     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03662     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03663   } else {
03664     v->vehstatus &= ~VS_TRAIN_SLOWING;
03665   }
03666 
03667   if (!TrainCanLeaveTile(v)) return true;
03668 
03669   /* Determine the non-diagonal direction in which we will exit this tile */
03670   DiagDirection dir = TrainExitDir(v->direction, v->track);
03671   /* Calculate next tile */
03672   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03673 
03674   /* Determine the track status on the next tile */
03675   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03676   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03677 
03678   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03679   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03680 
03681   /* We are sure the train is not entering a depot, it is detected above */
03682 
03683   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03684   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03685   if (_settings_game.pf.forbid_90_deg) {
03686     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03687   }
03688 
03689   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03690   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03691     return TrainApproachingLineEnd(v, false, reverse);
03692   }
03693 
03694   /* approaching red signal */
03695   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03696 
03697   /* approaching a rail/road crossing? then make it red */
03698   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03699 
03700   return true;
03701 }
03702 
03703 
03704 static bool TrainLocoHandler(Train *v, bool mode)
03705 {
03706   /* train has crashed? */
03707   if (v->vehstatus & VS_CRASHED) {
03708     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03709   }
03710 
03711   if (v->force_proceed != TFP_NONE) {
03712     ClrBit(v->flags, VRF_TRAIN_STUCK);
03713     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03714   }
03715 
03716   /* train is broken down? */
03717   if (v->HandleBreakdown()) return true;
03718 
03719   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03720     ReverseTrainDirection(v);
03721   }
03722 
03723   /* exit if train is stopped */
03724   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03725 
03726   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03727   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03728     v->wait_counter = 0;
03729     v->cur_speed = 0;
03730     v->subspeed = 0;
03731     ClrBit(v->flags, VRF_LEAVING_STATION);
03732     ReverseTrainDirection(v);
03733     return true;
03734   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03735     /* Try to reserve a path when leaving the station as we
03736      * might not be marked as wanting a reservation, e.g.
03737      * when an overlength train gets turned around in a station. */
03738     DiagDirection dir = TrainExitDir(v->direction, v->track);
03739     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03740 
03741     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03742       TryPathReserve(v, true, true);
03743     }
03744     ClrBit(v->flags, VRF_LEAVING_STATION);
03745   }
03746 
03747   v->HandleLoading(mode);
03748 
03749   if (v->current_order.IsType(OT_LOADING)) return true;
03750 
03751   if (CheckTrainStayInDepot(v)) return true;
03752 
03753   if (!mode) v->ShowVisualEffect();
03754 
03755   /* We had no order but have an order now, do look ahead. */
03756   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03757     CheckNextTrainTile(v);
03758   }
03759 
03760   /* Handle stuck trains. */
03761   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03762     ++v->wait_counter;
03763 
03764     /* Should we try reversing this tick if still stuck? */
03765     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03766 
03767     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03768     if (!TryPathReserve(v)) {
03769       /* Still stuck. */
03770       if (turn_around) ReverseTrainDirection(v);
03771 
03772       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03773         /* Show message to player. */
03774         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03775           SetDParam(0, v->index);
03776           AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_STUCK, v->index);
03777         }
03778         v->wait_counter = 0;
03779       }
03780       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03781       if (v->force_proceed == TFP_NONE) return true;
03782       ClrBit(v->flags, VRF_TRAIN_STUCK);
03783       v->wait_counter = 0;
03784       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03785     }
03786   }
03787 
03788   if (v->current_order.IsType(OT_LEAVESTATION)) {
03789     v->current_order.Free();
03790     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03791     return true;
03792   }
03793 
03794   int j = v->UpdateSpeed();
03795 
03796   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03797   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03798     /* If we manually stopped, we're not force-proceeding anymore. */
03799     v->force_proceed = TFP_NONE;
03800     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03801   }
03802 
03803   int adv_spd = v->GetAdvanceDistance();
03804   if (j < adv_spd) {
03805     /* if the vehicle has speed 0, update the last_speed field. */
03806     if (v->cur_speed == 0) v->SetLastSpeed();
03807   } else {
03808     TrainCheckIfLineEnds(v);
03809     /* Loop until the train has finished moving. */
03810     for (;;) {
03811       j -= adv_spd;
03812       TrainController(v, NULL);
03813       /* Don't continue to move if the train crashed. */
03814       if (CheckTrainCollision(v)) break;
03815       /* Determine distance to next map position */
03816       adv_spd = v->GetAdvanceDistance();
03817 
03818       /* No more moving this tick */
03819       if (j < adv_spd || v->cur_speed == 0) break;
03820 
03821       OrderType order_type = v->current_order.GetType();
03822       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03823       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03824             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03825             IsTileType(v->tile, MP_STATION) &&
03826             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03827         ProcessOrders(v);
03828       }
03829     }
03830     v->SetLastSpeed();
03831   }
03832 
03833   for (Train *u = v; u != NULL; u = u->Next()) {
03834     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03835 
03836     u->UpdateViewport(false, false);
03837   }
03838 
03839   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03840 
03841   return true;
03842 }
03843 
03848 Money Train::GetRunningCost() const
03849 {
03850   Money cost = 0;
03851   const Train *v = this;
03852 
03853   do {
03854     const Engine *e = v->GetEngine();
03855     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03856 
03857     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03858     if (cost_factor == 0) continue;
03859 
03860     /* Halve running cost for multiheaded parts */
03861     if (v->IsMultiheaded()) cost_factor /= 2;
03862 
03863     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03864   } while ((v = v->GetNextVehicle()) != NULL);
03865 
03866   return cost;
03867 }
03868 
03873 bool Train::Tick()
03874 {
03875   this->tick_counter++;
03876 
03877   if (this->IsFrontEngine()) {
03878     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03879 
03880     this->current_order_time++;
03881 
03882     if (!TrainLocoHandler(this, false)) return false;
03883 
03884     return TrainLocoHandler(this, true);
03885   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03886     /* Delete flooded standalone wagon chain */
03887     if (++this->crash_anim_pos >= 4400) {
03888       delete this;
03889       return false;
03890     }
03891   }
03892 
03893   return true;
03894 }
03895 
03900 static void CheckIfTrainNeedsService(Train *v)
03901 {
03902   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03903   if (v->IsChainInDepot()) {
03904     VehicleServiceInDepot(v);
03905     return;
03906   }
03907 
03908   uint max_penalty;
03909   switch (_settings_game.pf.pathfinder_for_trains) {
03910     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03911     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03912     default: NOT_REACHED();
03913   }
03914 
03915   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03916   /* Only go to the depot if it is not too far out of our way. */
03917   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03918     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03919       /* If we were already heading for a depot but it has
03920        * suddenly moved farther away, we continue our normal
03921        * schedule? */
03922       v->current_order.MakeDummy();
03923       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03924     }
03925     return;
03926   }
03927 
03928   DepotID depot = GetDepotIndex(tfdd.tile);
03929 
03930   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03931       v->current_order.GetDestination() != depot &&
03932       !Chance16(3, 16)) {
03933     return;
03934   }
03935 
03936   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03937   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03938   v->dest_tile = tfdd.tile;
03939   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03940 }
03941 
03943 void Train::OnNewDay()
03944 {
03945   AgeVehicle(this);
03946 
03947   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03948 
03949   if (this->IsFrontEngine()) {
03950     CheckVehicleBreakdown(this);
03951 
03952     CheckIfTrainNeedsService(this);
03953 
03954     CheckOrders(this);
03955 
03956     /* update destination */
03957     if (this->current_order.IsType(OT_GOTO_STATION)) {
03958       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03959       if (tile != INVALID_TILE) this->dest_tile = tile;
03960     }
03961 
03962     if (this->running_ticks != 0) {
03963       /* running costs */
03964       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03965 
03966       this->profit_this_year -= cost.GetCost();
03967       this->running_ticks = 0;
03968 
03969       SubtractMoneyFromCompanyFract(this->owner, cost);
03970 
03971       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03972       SetWindowClassesDirty(WC_TRAINS_LIST);
03973     }
03974   }
03975 }
03976 
03981 Trackdir Train::GetVehicleTrackdir() const
03982 {
03983   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03984 
03985   if (this->track == TRACK_BIT_DEPOT) {
03986     /* We'll assume the train is facing outwards */
03987     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03988   }
03989 
03990   if (this->track == TRACK_BIT_WORMHOLE) {
03991     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03992     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03993   }
03994 
03995   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03996 }