train_cmd.cpp

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00001 /* $Id: train_cmd.cpp 24846 2012-12-23 21:09:09Z frosch $ */
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 
00729     v->engine_type = e->index;
00730     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00731 
00732     v->reliability = e->reliability;
00733     v->reliability_spd_dec = e->reliability_spd_dec;
00734     v->max_age = e->GetLifeLengthInDays();
00735 
00736     v->railtype = rvi->railtype;
00737     _new_vehicle_id = v->index;
00738 
00739     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00740     v->date_of_last_service = _date;
00741     v->build_year = _cur_year;
00742     v->cur_image = SPR_IMG_QUERY;
00743     v->random_bits = VehicleRandomBits();
00744 
00745     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00746 
00747     v->group_id = DEFAULT_GROUP;
00748 
00749     v->SetFrontEngine();
00750     v->SetEngine();
00751 
00752     VehicleUpdatePosition(v);
00753 
00754     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00755       AddRearEngineToMultiheadedTrain(v);
00756     } else {
00757       AddArticulatedParts(v);
00758     }
00759 
00760     v->ConsistChanged(false);
00761     UpdateTrainGroupID(v);
00762 
00763     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00764       NormalizeTrainVehInDepot(v);
00765     }
00766 
00767     CheckConsistencyOfArticulatedVehicle(v);
00768   }
00769 
00770   return CommandCost();
00771 }
00772 
00773 static Train *FindGoodVehiclePos(const Train *src)
00774 {
00775   EngineID eng = src->engine_type;
00776   TileIndex tile = src->tile;
00777 
00778   Train *dst;
00779   FOR_ALL_TRAINS(dst) {
00780     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00781       /* check so all vehicles in the line have the same engine. */
00782       Train *t = dst;
00783       while (t->engine_type == eng) {
00784         t = t->Next();
00785         if (t == NULL) return dst;
00786       }
00787     }
00788   }
00789 
00790   return NULL;
00791 }
00792 
00794 typedef SmallVector<Train *, 16> TrainList;
00795 
00801 static void MakeTrainBackup(TrainList &list, Train *t)
00802 {
00803   for (; t != NULL; t = t->Next()) *list.Append() = t;
00804 }
00805 
00810 static void RestoreTrainBackup(TrainList &list)
00811 {
00812   /* No train, nothing to do. */
00813   if (list.Length() == 0) return;
00814 
00815   Train *prev = NULL;
00816   /* Iterate over the list and rebuild it. */
00817   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00818     Train *t = *iter;
00819     if (prev != NULL) {
00820       prev->SetNext(t);
00821     } else if (t->Previous() != NULL) {
00822       /* Make sure the head of the train is always the first in the chain. */
00823       t->Previous()->SetNext(NULL);
00824     }
00825     prev = t;
00826   }
00827 }
00828 
00834 static void RemoveFromConsist(Train *part, bool chain = false)
00835 {
00836   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00837 
00838   /* Unlink at the front, but make it point to the next
00839    * vehicle after the to be remove part. */
00840   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00841 
00842   /* Unlink at the back */
00843   tail->SetNext(NULL);
00844 }
00845 
00851 static void InsertInConsist(Train *dst, Train *chain)
00852 {
00853   /* We do not want to add something in the middle of an articulated part. */
00854   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00855 
00856   chain->Last()->SetNext(dst->Next());
00857   dst->SetNext(chain);
00858 }
00859 
00865 static void NormaliseDualHeads(Train *t)
00866 {
00867   for (; t != NULL; t = t->GetNextVehicle()) {
00868     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00869 
00870     /* Make sure that there are no free cars before next engine */
00871     Train *u;
00872     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00873 
00874     if (u == t->other_multiheaded_part) continue;
00875 
00876     /* Remove the part from the 'wrong' train */
00877     RemoveFromConsist(t->other_multiheaded_part);
00878     /* And add it to the 'right' train */
00879     InsertInConsist(u, t->other_multiheaded_part);
00880   }
00881 }
00882 
00887 static void NormaliseSubtypes(Train *chain)
00888 {
00889   /* Nothing to do */
00890   if (chain == NULL) return;
00891 
00892   /* We must be the first in the chain. */
00893   assert(chain->Previous() == NULL);
00894 
00895   /* Set the appropriate bits for the first in the chain. */
00896   if (chain->IsWagon()) {
00897     chain->SetFreeWagon();
00898   } else {
00899     assert(chain->IsEngine());
00900     chain->SetFrontEngine();
00901   }
00902 
00903   /* Now clear the bits for the rest of the chain */
00904   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00905     t->ClearFreeWagon();
00906     t->ClearFrontEngine();
00907   }
00908 }
00909 
00919 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00920 {
00921   /* Just add 'new' engines and subtract the original ones.
00922    * If that's less than or equal to 0 we can be sure we did
00923    * not add any engines (read: trains) along the way. */
00924   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00925       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00926       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00927       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00928     return CommandCost();
00929   }
00930 
00931   /* Get a free unit number and check whether it's within the bounds.
00932    * There will always be a maximum of one new train. */
00933   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00934 
00935   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00936 }
00937 
00943 static CommandCost CheckTrainAttachment(Train *t)
00944 {
00945   /* No multi-part train, no need to check. */
00946   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00947 
00948   /* The maximum length for a train. For each part we decrease this by one
00949    * and if the result is negative the train is simply too long. */
00950   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00951 
00952   Train *head = t;
00953   Train *prev = t;
00954 
00955   /* Break the prev -> t link so it always holds within the loop. */
00956   t = t->Next();
00957   prev->SetNext(NULL);
00958 
00959   /* Make sure the cache is cleared. */
00960   head->InvalidateNewGRFCache();
00961 
00962   while (t != NULL) {
00963     allowed_len -= t->gcache.cached_veh_length;
00964 
00965     Train *next = t->Next();
00966 
00967     /* Unlink the to-be-added piece; it is already unlinked from the previous
00968      * part due to the fact that the prev -> t link is broken. */
00969     t->SetNext(NULL);
00970 
00971     /* Don't check callback for articulated or rear dual headed parts */
00972     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00973       /* Back up and clear the first_engine data to avoid using wagon override group */
00974       EngineID first_engine = t->gcache.first_engine;
00975       t->gcache.first_engine = INVALID_ENGINE;
00976 
00977       /* We don't want the cache to interfere. head's cache is cleared before
00978        * the loop and after each callback does not need to be cleared here. */
00979       t->InvalidateNewGRFCache();
00980 
00981       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00982 
00983       /* Restore original first_engine data */
00984       t->gcache.first_engine = first_engine;
00985 
00986       /* We do not want to remember any cached variables from the test run */
00987       t->InvalidateNewGRFCache();
00988       head->InvalidateNewGRFCache();
00989 
00990       if (callback != CALLBACK_FAILED) {
00991         /* A failing callback means everything is okay */
00992         StringID error = STR_NULL;
00993 
00994         if (head->GetGRF()->grf_version < 8) {
00995           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00996           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00997           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
00998         } else {
00999           if (callback < 0x400) {
01000             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01001           } else {
01002             switch (callback) {
01003               case 0x400: // allow if railtypes match (always the case for OpenTTD)
01004               case 0x401: // allow
01005                 break;
01006 
01007               default:    // unknown reason -> disallow
01008               case 0x402: // disallow attaching
01009                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01010                 break;
01011             }
01012           }
01013         }
01014 
01015         if (error != STR_NULL) return_cmd_error(error);
01016       }
01017     }
01018 
01019     /* And link it to the new part. */
01020     prev->SetNext(t);
01021     prev = t;
01022     t = next;
01023   }
01024 
01025   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01026   return CommandCost();
01027 }
01028 
01039 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01040 {
01041   /* Check whether we may actually construct the trains. */
01042   CommandCost ret = CheckTrainAttachment(src);
01043   if (ret.Failed()) return ret;
01044   ret = CheckTrainAttachment(dst);
01045   if (ret.Failed()) return ret;
01046 
01047   /* Check whether we need to build a new train. */
01048   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01049 }
01050 
01059 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01060 {
01061   /* First determine the front of the two resulting trains */
01062   if (*src_head == *dst_head) {
01063     /* If we aren't moving part(s) to a new train, we are just moving the
01064      * front back and there is not destination head. */
01065     *dst_head = NULL;
01066   } else if (*dst_head == NULL) {
01067     /* If we are moving to a new train the head of the move train would become
01068      * the head of the new vehicle. */
01069     *dst_head = src;
01070   }
01071 
01072   if (src == *src_head) {
01073     /* If we are moving the front of a train then we are, in effect, creating
01074      * a new head for the train. Point to that. Unless we are moving the whole
01075      * train in which case there is not 'source' train anymore.
01076      * In case we are a multiheaded part we want the complete thing to come
01077      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01078      * that is followed by a rear multihead we do not want to include that. */
01079     *src_head = move_chain ? NULL :
01080         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01081   }
01082 
01083   /* Now it's just simply removing the part that we are going to move from the
01084    * source train and *if* the destination is a not a new train add the chain
01085    * at the destination location. */
01086   RemoveFromConsist(src, move_chain);
01087   if (*dst_head != src) InsertInConsist(dst, src);
01088 
01089   /* Now normalise the dual heads, that is move the dual heads around in such
01090    * a way that the head and rear of a dual head are in the same train */
01091   NormaliseDualHeads(*src_head);
01092   NormaliseDualHeads(*dst_head);
01093 }
01094 
01100 static void NormaliseTrainHead(Train *head)
01101 {
01102   /* Not much to do! */
01103   if (head == NULL) return;
01104 
01105   /* Tell the 'world' the train changed. */
01106   head->ConsistChanged(false);
01107   UpdateTrainGroupID(head);
01108 
01109   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01110   if (!head->IsFrontEngine()) return;
01111 
01112   /* Update the refit button and window */
01113   InvalidateWindowData(WC_VEHICLE_REFIT, head->index, VIWD_CONSIST_CHANGED);
01114   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01115 
01116   /* If we don't have a unit number yet, set one. */
01117   if (head->unitnumber != 0) return;
01118   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01119 }
01120 
01133 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01134 {
01135   VehicleID s = GB(p1, 0, 20);
01136   VehicleID d = GB(p2, 0, 20);
01137   bool move_chain = HasBit(p1, 20);
01138 
01139   Train *src = Train::GetIfValid(s);
01140   if (src == NULL) return CMD_ERROR;
01141 
01142   CommandCost ret = CheckOwnership(src->owner);
01143   if (ret.Failed()) return ret;
01144 
01145   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01146   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01147 
01148   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01149   Train *dst;
01150   if (d == INVALID_VEHICLE) {
01151     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01152   } else {
01153     dst = Train::GetIfValid(d);
01154     if (dst == NULL) return CMD_ERROR;
01155 
01156     CommandCost ret = CheckOwnership(dst->owner);
01157     if (ret.Failed()) return ret;
01158 
01159     /* Do not allow appending to crashed vehicles, too */
01160     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01161   }
01162 
01163   /* if an articulated part is being handled, deal with its parent vehicle */
01164   src = src->GetFirstEnginePart();
01165   if (dst != NULL) {
01166     dst = dst->GetFirstEnginePart();
01167   }
01168 
01169   /* don't move the same vehicle.. */
01170   if (src == dst) return CommandCost();
01171 
01172   /* locate the head of the two chains */
01173   Train *src_head = src->First();
01174   Train *dst_head;
01175   if (dst != NULL) {
01176     dst_head = dst->First();
01177     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01178     /* Now deal with articulated part of destination wagon */
01179     dst = dst->GetLastEnginePart();
01180   } else {
01181     dst_head = NULL;
01182   }
01183 
01184   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01185 
01186   /* When moving all wagons, we can't have the same src_head and dst_head */
01187   if (move_chain && src_head == dst_head) return CommandCost();
01188 
01189   /* When moving a multiheaded part to be place after itself, bail out. */
01190   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01191 
01192   /* Check if all vehicles in the source train are stopped inside a depot. */
01193   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01194 
01195   /* Check if all vehicles in the destination train are stopped inside a depot. */
01196   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01197 
01198   /* First make a backup of the order of the trains. That way we can do
01199    * whatever we want with the order and later on easily revert. */
01200   TrainList original_src;
01201   TrainList original_dst;
01202 
01203   MakeTrainBackup(original_src, src_head);
01204   MakeTrainBackup(original_dst, dst_head);
01205 
01206   /* Also make backup of the original heads as ArrangeTrains can change them.
01207    * For the destination head we do not care if it is the same as the source
01208    * head because in that case it's just a copy. */
01209   Train *original_src_head = src_head;
01210   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01211 
01212   /* We want this information from before the rearrangement, but execute this after the validation. */
01213   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01214   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01215 
01216   /* (Re)arrange the trains in the wanted arrangement. */
01217   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01218 
01219   if ((flags & DC_AUTOREPLACE) == 0) {
01220     /* If the autoreplace flag is set we do not need to test for the validity
01221      * because we are going to revert the train to its original state. As we
01222      * assume the original state was correct autoreplace can skip this. */
01223     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01224     if (ret.Failed()) {
01225       /* Restore the train we had. */
01226       RestoreTrainBackup(original_src);
01227       RestoreTrainBackup(original_dst);
01228       return ret;
01229     }
01230   }
01231 
01232   /* do it? */
01233   if (flags & DC_EXEC) {
01234     /* Remove old heads from the statistics */
01235     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01236     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01237 
01238     /* First normalise the sub types of the chains. */
01239     NormaliseSubtypes(src_head);
01240     NormaliseSubtypes(dst_head);
01241 
01242     /* There are 14 different cases:
01243      *  1) front engine gets moved to a new train, it stays a front engine.
01244      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01245      *     b) the 'next' part is an engine that becomes a front engine.
01246      *     c) there is no 'next' part, nothing else happens
01247      *  2) front engine gets moved to another train, it is not a front engine anymore
01248      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01249      *     b) the 'next' part is an engine that becomes a front engine.
01250      *     c) there is no 'next' part, nothing else happens
01251      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01252      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01253      *     b) the 'next' part is an engine that becomes a front engine.
01254      *  4) free wagon gets moved
01255      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01256      *     b) the 'next' part is an engine that becomes a front engine.
01257      *     c) there is no 'next' part, nothing else happens
01258      *  5) non front engine gets moved and becomes a new train, nothing else happens
01259      *  6) non front engine gets moved within a train / to another train, nothing hapens
01260      *  7) wagon gets moved, nothing happens
01261      */
01262     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01263       /* Cases #2 and #3: the front engine gets trashed. */
01264       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01265       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01266       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01267       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01268       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01269       SetWindowDirty(WC_COMPANY, _current_company);
01270 
01271       /* Delete orders, group stuff and the unit number as we're not the
01272        * front of any vehicle anymore. */
01273       DeleteVehicleOrders(src);
01274       RemoveVehicleFromGroup(src);
01275       src->unitnumber = 0;
01276     }
01277 
01278     /* We weren't a front engine but are becoming one. So
01279      * we should be put in the default group. */
01280     if (original_src_head != src && dst_head == src) {
01281       SetTrainGroupID(src, DEFAULT_GROUP);
01282       SetWindowDirty(WC_COMPANY, _current_company);
01283     }
01284 
01285     /* Add new heads to statistics */
01286     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01287     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01288 
01289     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01290     NormaliseTrainHead(src_head);
01291     NormaliseTrainHead(dst_head);
01292 
01293     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01294       CheckCargoCapacity(src_head);
01295       CheckCargoCapacity(dst_head);
01296     }
01297 
01298     /* We are undoubtedly changing something in the depot and train list. */
01299     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01300     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01301   } else {
01302     /* We don't want to execute what we're just tried. */
01303     RestoreTrainBackup(original_src);
01304     RestoreTrainBackup(original_dst);
01305   }
01306 
01307   return CommandCost();
01308 }
01309 
01321 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01322 {
01323   /* Check if we deleted a vehicle window */
01324   Window *w = NULL;
01325 
01326   /* Sell a chain of vehicles or not? */
01327   bool sell_chain = HasBit(data, 0);
01328 
01329   Train *v = Train::From(t)->GetFirstEnginePart();
01330   Train *first = v->First();
01331 
01332   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01333 
01334   /* First make a backup of the order of the train. That way we can do
01335    * whatever we want with the order and later on easily revert. */
01336   TrainList original;
01337   MakeTrainBackup(original, first);
01338 
01339   /* We need to keep track of the new head and the head of what we're going to sell. */
01340   Train *new_head = first;
01341   Train *sell_head = NULL;
01342 
01343   /* Split the train in the wanted way. */
01344   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01345 
01346   /* We don't need to validate the second train; it's going to be sold. */
01347   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01348   if (ret.Failed()) {
01349     /* Restore the train we had. */
01350     RestoreTrainBackup(original);
01351     return ret;
01352   }
01353 
01354   CommandCost cost(EXPENSES_NEW_VEHICLES);
01355   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01356 
01357   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01358     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01359   }
01360 
01361   /* do it? */
01362   if (flags & DC_EXEC) {
01363     /* First normalise the sub types of the chain. */
01364     NormaliseSubtypes(new_head);
01365 
01366     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01367       /* We are selling the front engine. In this case we want to
01368        * 'give' the order, unit number and such to the new head. */
01369       new_head->orders.list = first->orders.list;
01370       new_head->AddToShared(first);
01371       DeleteVehicleOrders(first);
01372 
01373       /* Copy other important data from the front engine */
01374       new_head->CopyVehicleConfigAndStatistics(first);
01375       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01376 
01377       /* If we deleted a window then open a new one for the 'new' train */
01378       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01379     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01380       OrderBackup::Backup(v, user);
01381     }
01382 
01383     /* We need to update the information about the train. */
01384     NormaliseTrainHead(new_head);
01385 
01386     /* We are undoubtedly changing something in the depot and train list. */
01387     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01388     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01389 
01390     /* Actually delete the sold 'goods' */
01391     delete sell_head;
01392   } else {
01393     /* We don't want to execute what we're just tried. */
01394     RestoreTrainBackup(original);
01395   }
01396 
01397   return cost;
01398 }
01399 
01400 void Train::UpdateDeltaXY(Direction direction)
01401 {
01402   /* Set common defaults. */
01403   this->x_offs    = -1;
01404   this->y_offs    = -1;
01405   this->x_extent  =  3;
01406   this->y_extent  =  3;
01407   this->z_extent  =  6;
01408   this->x_bb_offs =  0;
01409   this->y_bb_offs =  0;
01410 
01411   if (!IsDiagonalDirection(direction)) {
01412     static const int _sign_table[] =
01413     {
01414       // x, y
01415       -1, -1, // DIR_N
01416       -1,  1, // DIR_E
01417        1,  1, // DIR_S
01418        1, -1, // DIR_W
01419     };
01420 
01421     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01422 
01423     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01424     this->x_offs -= half_shorten * _sign_table[direction];
01425     this->y_offs -= half_shorten * _sign_table[direction + 1];
01426     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01427     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01428   } else {
01429     switch (direction) {
01430         /* Shorten southern corner of the bounding box according the vehicle length
01431          * and center the bounding box on the vehicle. */
01432       case DIR_NE:
01433         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01434         this->x_extent  = this->gcache.cached_veh_length - 1;
01435         this->x_bb_offs = -1;
01436         break;
01437 
01438       case DIR_NW:
01439         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01440         this->y_extent  = this->gcache.cached_veh_length - 1;
01441         this->y_bb_offs = -1;
01442         break;
01443 
01444         /* Move northern corner of the bounding box down according to vehicle length
01445          * and center the bounding box on the vehicle. */
01446       case DIR_SW:
01447         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01448         this->x_extent  = VEHICLE_LENGTH - 1;
01449         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01450         break;
01451 
01452       case DIR_SE:
01453         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01454         this->y_extent  = VEHICLE_LENGTH - 1;
01455         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01456         break;
01457 
01458       default:
01459         NOT_REACHED();
01460     }
01461   }
01462 }
01463 
01468 static void MarkTrainAsStuck(Train *v)
01469 {
01470   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01471     /* It is the first time the problem occurred, set the "train stuck" flag. */
01472     SetBit(v->flags, VRF_TRAIN_STUCK);
01473 
01474     v->wait_counter = 0;
01475 
01476     /* Stop train */
01477     v->cur_speed = 0;
01478     v->subspeed = 0;
01479     v->SetLastSpeed();
01480 
01481     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01482   }
01483 }
01484 
01492 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01493 {
01494   uint16 flag1 = *swap_flag1;
01495   uint16 flag2 = *swap_flag2;
01496 
01497   /* Clear the flags */
01498   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01499   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01500   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01501   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01502 
01503   /* Reverse the rail-flags (if needed) */
01504   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01505     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01506   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01507     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01508   }
01509   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01510     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01511   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01512     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01513   }
01514 }
01515 
01520 static void UpdateStatusAfterSwap(Train *v)
01521 {
01522   /* Reverse the direction. */
01523   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01524 
01525   /* Call the proper EnterTile function unless we are in a wormhole. */
01526   if (v->track != TRACK_BIT_WORMHOLE) {
01527     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01528   } else {
01529     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01530      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01531      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01532      * when we shouldn't have. Check if this is the case. */
01533     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01534     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01535       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01536       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01537         /* We have just left the wormhole, possibly set the
01538          * "goingdown" bit. UpdateInclination() can be used
01539          * because we are at the border of the tile. */
01540         VehicleUpdatePosition(v);
01541         v->UpdateInclination(true, true);
01542         return;
01543       }
01544     }
01545   }
01546 
01547   VehicleUpdatePosition(v);
01548   v->UpdateViewport(true, true);
01549 }
01550 
01557 void ReverseTrainSwapVeh(Train *v, int l, int r)
01558 {
01559   Train *a, *b;
01560 
01561   /* locate vehicles to swap */
01562   for (a = v; l != 0; l--) a = a->Next();
01563   for (b = v; r != 0; r--) b = b->Next();
01564 
01565   if (a != b) {
01566     /* swap the hidden bits */
01567     {
01568       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01569       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01570       a->vehstatus = tmp;
01571     }
01572 
01573     Swap(a->track, b->track);
01574     Swap(a->direction, b->direction);
01575     Swap(a->x_pos, b->x_pos);
01576     Swap(a->y_pos, b->y_pos);
01577     Swap(a->tile,  b->tile);
01578     Swap(a->z_pos, b->z_pos);
01579 
01580     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01581 
01582     UpdateStatusAfterSwap(a);
01583     UpdateStatusAfterSwap(b);
01584   } else {
01585     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01586      * This is a little bit redundant way, a->gv_flags will
01587      * be (re)set twice, but it reduces code duplication */
01588     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01589     UpdateStatusAfterSwap(a);
01590   }
01591 }
01592 
01593 
01599 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01600 {
01601   return (v->type == VEH_TRAIN) ? v : NULL;
01602 }
01603 
01604 
01611 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01612 {
01613   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01614 
01615   Train *t = Train::From(v);
01616   if (!t->IsFrontEngine()) return NULL;
01617 
01618   TileIndex tile = *(TileIndex *)data;
01619 
01620   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01621 
01622   return t;
01623 }
01624 
01625 
01632 static bool TrainApproachingCrossing(TileIndex tile)
01633 {
01634   assert(IsLevelCrossingTile(tile));
01635 
01636   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01637   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01638 
01639   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01640 
01641   dir = ReverseDiagDir(dir);
01642   tile_from = tile + TileOffsByDiagDir(dir);
01643 
01644   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01645 }
01646 
01647 
01654 void UpdateLevelCrossing(TileIndex tile, bool sound)
01655 {
01656   assert(IsLevelCrossingTile(tile));
01657 
01658   /* train on crossing || train approaching crossing || reserved */
01659   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01660 
01661   if (new_state != IsCrossingBarred(tile)) {
01662     if (new_state && sound) {
01663       if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01664     }
01665     SetCrossingBarred(tile, new_state);
01666     MarkTileDirtyByTile(tile);
01667   }
01668 }
01669 
01670 
01676 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01677 {
01678   if (!IsCrossingBarred(tile)) {
01679     BarCrossing(tile);
01680     if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01681     MarkTileDirtyByTile(tile);
01682   }
01683 }
01684 
01685 
01691 static void AdvanceWagonsBeforeSwap(Train *v)
01692 {
01693   Train *base = v;
01694   Train *first = base; // first vehicle to move
01695   Train *last = v->Last(); // last vehicle to move
01696   uint length = CountVehiclesInChain(v);
01697 
01698   while (length > 2) {
01699     last = last->Previous();
01700     first = first->Next();
01701 
01702     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01703 
01704     /* do not update images now
01705      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01706     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01707 
01708     base = first; // == base->Next()
01709     length -= 2;
01710   }
01711 }
01712 
01713 
01719 static void AdvanceWagonsAfterSwap(Train *v)
01720 {
01721   /* first of all, fix the situation when the train was entering a depot */
01722   Train *dep = v; // last vehicle in front of just left depot
01723   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01724     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01725   }
01726 
01727   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01728 
01729   if (leave != NULL) {
01730     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01731     int d = TicksToLeaveDepot(dep);
01732 
01733     if (d <= 0) {
01734       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01735       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01736       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01737     }
01738   } else {
01739     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01740   }
01741 
01742   Train *base = v;
01743   Train *first = base; // first vehicle to move
01744   Train *last = v->Last(); // last vehicle to move
01745   uint length = CountVehiclesInChain(v);
01746 
01747   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01748    * they have already correct spacing, so we have to make sure they are moved how they should */
01749   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01750 
01751   while (length > 2) {
01752     /* we reached vehicle (originally) in front of a depot, stop now
01753      * (we would move wagons that are already moved with new wagon length). */
01754     if (base == dep) break;
01755 
01756     /* the last wagon was that one leaving a depot, so do not move it anymore */
01757     if (last == dep) nomove = true;
01758 
01759     last = last->Previous();
01760     first = first->Next();
01761 
01762     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01763 
01764     /* do not update images now */
01765     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01766 
01767     base = first; // == base->Next()
01768     length -= 2;
01769   }
01770 }
01771 
01776 void ReverseTrainDirection(Train *v)
01777 {
01778   if (IsRailDepotTile(v->tile)) {
01779     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01780   }
01781 
01782   /* Clear path reservation in front if train is not stuck. */
01783   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01784 
01785   /* Check if we were approaching a rail/road-crossing */
01786   TileIndex crossing = TrainApproachingCrossingTile(v);
01787 
01788   /* count number of vehicles */
01789   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01790 
01791   AdvanceWagonsBeforeSwap(v);
01792 
01793   /* swap start<>end, start+1<>end-1, ... */
01794   int l = 0;
01795   do {
01796     ReverseTrainSwapVeh(v, l++, r--);
01797   } while (l <= r);
01798 
01799   AdvanceWagonsAfterSwap(v);
01800 
01801   if (IsRailDepotTile(v->tile)) {
01802     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01803   }
01804 
01805   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01806 
01807   ClrBit(v->flags, VRF_REVERSING);
01808 
01809   /* recalculate cached data */
01810   v->ConsistChanged(true);
01811 
01812   /* update all images */
01813   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01814 
01815   /* update crossing we were approaching */
01816   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01817 
01818   /* maybe we are approaching crossing now, after reversal */
01819   crossing = TrainApproachingCrossingTile(v);
01820   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01821 
01822   /* If we are inside a depot after reversing, don't bother with path reserving. */
01823   if (v->track == TRACK_BIT_DEPOT) {
01824     /* Can't be stuck here as inside a depot is always a safe tile. */
01825     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01826     ClrBit(v->flags, VRF_TRAIN_STUCK);
01827     return;
01828   }
01829 
01830   /* TrainExitDir does not always produce the desired dir for depots and
01831    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01832   DiagDirection dir = TrainExitDir(v->direction, v->track);
01833   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01834 
01835   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01836     /* If we are currently on a tile with conventional signals, we can't treat the
01837      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01838     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01839       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01840       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01841 
01842     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01843     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01844 
01845     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01846     if (TryPathReserve(v, false, first_tile_okay)) {
01847       /* Do a look-ahead now in case our current tile was already a safe tile. */
01848       CheckNextTrainTile(v);
01849     } else if (v->current_order.GetType() != OT_LOADING) {
01850       /* Do not wait for a way out when we're still loading */
01851       MarkTrainAsStuck(v);
01852     }
01853   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01854     /* A train not inside a PBS block can't be stuck. */
01855     ClrBit(v->flags, VRF_TRAIN_STUCK);
01856     v->wait_counter = 0;
01857   }
01858 }
01859 
01869 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01870 {
01871   Train *v = Train::GetIfValid(p1);
01872   if (v == NULL) return CMD_ERROR;
01873 
01874   CommandCost ret = CheckOwnership(v->owner);
01875   if (ret.Failed()) return ret;
01876 
01877   if (p2 != 0) {
01878     /* turn a single unit around */
01879 
01880     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01881       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01882     }
01883     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01884 
01885     Train *front = v->First();
01886     /* make sure the vehicle is stopped in the depot */
01887     if (!front->IsStoppedInDepot()) {
01888       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01889     }
01890 
01891     if (flags & DC_EXEC) {
01892       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01893 
01894       front->ConsistChanged(false);
01895       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01896       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01897       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01898       SetWindowClassesDirty(WC_TRAINS_LIST);
01899     }
01900   } else {
01901     /* turn the whole train around */
01902     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01903 
01904     if (flags & DC_EXEC) {
01905       /* Properly leave the station if we are loading and won't be loading anymore */
01906       if (v->current_order.IsType(OT_LOADING)) {
01907         const Vehicle *last = v;
01908         while (last->Next() != NULL) last = last->Next();
01909 
01910         /* not a station || different station --> leave the station */
01911         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01912           v->LeaveStation();
01913         }
01914       }
01915 
01916       /* We cancel any 'skip signal at dangers' here */
01917       v->force_proceed = TFP_NONE;
01918       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01919 
01920       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01921         ToggleBit(v->flags, VRF_REVERSING);
01922       } else {
01923         v->cur_speed = 0;
01924         v->SetLastSpeed();
01925         HideFillingPercent(&v->fill_percent_te_id);
01926         ReverseTrainDirection(v);
01927       }
01928     }
01929   }
01930   return CommandCost();
01931 }
01932 
01942 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01943 {
01944   Train *t = Train::GetIfValid(p1);
01945   if (t == NULL) return CMD_ERROR;
01946 
01947   if (!t->IsPrimaryVehicle()) return CMD_ERROR;
01948 
01949   CommandCost ret = CheckOwnership(t->owner);
01950   if (ret.Failed()) return ret;
01951 
01952 
01953   if (flags & DC_EXEC) {
01954     /* If we are forced to proceed, cancel that order.
01955      * If we are marked stuck we would want to force the train
01956      * to proceed to the next signal. In the other cases we
01957      * would like to pass the signal at danger and run till the
01958      * next signal we encounter. */
01959     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsChainInDepot() ? TFP_STUCK : TFP_SIGNAL;
01960     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01961   }
01962 
01963   return CommandCost();
01964 }
01965 
01973 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01974 {
01975   assert(!(v->vehstatus & VS_CRASHED));
01976 
01977   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01978 
01979   PBSTileInfo origin = FollowTrainReservation(v);
01980   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01981 
01982   switch (_settings_game.pf.pathfinder_for_trains) {
01983     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01984     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01985 
01986     default: NOT_REACHED();
01987   }
01988 }
01989 
01997 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
01998 {
01999   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
02000   if (tfdd.best_length == UINT_MAX) return false;
02001 
02002   if (location    != NULL) *location    = tfdd.tile;
02003   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
02004   if (reverse     != NULL) *reverse     = tfdd.reverse;
02005 
02006   return true;
02007 }
02008 
02010 void Train::PlayLeaveStationSound() const
02011 {
02012   static const SoundFx sfx[] = {
02013     SND_04_TRAIN,
02014     SND_0A_TRAIN_HORN,
02015     SND_0A_TRAIN_HORN,
02016     SND_47_MAGLEV_2,
02017     SND_41_MAGLEV
02018   };
02019 
02020   if (PlayVehicleSound(this, VSE_START)) return;
02021 
02022   EngineID engtype = this->engine_type;
02023   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02024 }
02025 
02030 static void CheckNextTrainTile(Train *v)
02031 {
02032   /* Don't do any look-ahead if path_backoff_interval is 255. */
02033   if (_settings_game.pf.path_backoff_interval == 255) return;
02034 
02035   /* Exit if we are inside a depot. */
02036   if (v->track == TRACK_BIT_DEPOT) return;
02037 
02038   switch (v->current_order.GetType()) {
02039     /* Exit if we reached our destination depot. */
02040     case OT_GOTO_DEPOT:
02041       if (v->tile == v->dest_tile) return;
02042       break;
02043 
02044     case OT_GOTO_WAYPOINT:
02045       /* If we reached our waypoint, make sure we see that. */
02046       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02047       break;
02048 
02049     case OT_NOTHING:
02050     case OT_LEAVESTATION:
02051     case OT_LOADING:
02052       /* Exit if the current order doesn't have a destination, but the train has orders. */
02053       if (v->GetNumOrders() > 0) return;
02054       break;
02055 
02056     default:
02057       break;
02058   }
02059   /* Exit if we are on a station tile and are going to stop. */
02060   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02061 
02062   Trackdir td = v->GetVehicleTrackdir();
02063 
02064   /* On a tile with a red non-pbs signal, don't look ahead. */
02065   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02066       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02067       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02068 
02069   CFollowTrackRail ft(v);
02070   if (!ft.Follow(v->tile, td)) return;
02071 
02072   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02073     /* Next tile is not reserved. */
02074     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02075       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02076         /* If the next tile is a PBS signal, try to make a reservation. */
02077         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02078         if (_settings_game.pf.forbid_90_deg) {
02079           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02080         }
02081         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02082       }
02083     }
02084   }
02085 }
02086 
02092 static bool CheckTrainStayInDepot(Train *v)
02093 {
02094   /* bail out if not all wagons are in the same depot or not in a depot at all */
02095   for (const Train *u = v; u != NULL; u = u->Next()) {
02096     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02097   }
02098 
02099   /* if the train got no power, then keep it in the depot */
02100   if (v->gcache.cached_power == 0) {
02101     v->vehstatus |= VS_STOPPED;
02102     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02103     return true;
02104   }
02105 
02106   SigSegState seg_state;
02107 
02108   if (v->force_proceed == TFP_NONE) {
02109     /* force proceed was not pressed */
02110     if (++v->wait_counter < 37) {
02111       SetWindowClassesDirty(WC_TRAINS_LIST);
02112       return true;
02113     }
02114 
02115     v->wait_counter = 0;
02116 
02117     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02118     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02119       /* Full and no PBS signal in block or depot reserved, can't exit. */
02120       SetWindowClassesDirty(WC_TRAINS_LIST);
02121       return true;
02122     }
02123   } else {
02124     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02125   }
02126 
02127   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02128   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02129     /* We need to have a reservation for this to work. */
02130     if (HasDepotReservation(v->tile)) return true;
02131     SetDepotReservation(v->tile, true);
02132     VehicleEnterDepot(v);
02133     return true;
02134   }
02135 
02136   /* Only leave when we can reserve a path to our destination. */
02137   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02138     /* No path and no force proceed. */
02139     SetWindowClassesDirty(WC_TRAINS_LIST);
02140     MarkTrainAsStuck(v);
02141     return true;
02142   }
02143 
02144   SetDepotReservation(v->tile, true);
02145   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02146 
02147   VehicleServiceInDepot(v);
02148   SetWindowClassesDirty(WC_TRAINS_LIST);
02149   v->PlayLeaveStationSound();
02150 
02151   v->track = TRACK_BIT_X;
02152   if (v->direction & 2) v->track = TRACK_BIT_Y;
02153 
02154   v->vehstatus &= ~VS_HIDDEN;
02155   v->cur_speed = 0;
02156 
02157   v->UpdateViewport(true, true);
02158   VehicleUpdatePosition(v);
02159   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02160   v->UpdateAcceleration();
02161   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02162 
02163   return false;
02164 }
02165 
02172 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02173 {
02174   DiagDirection dir = TrackdirToExitdir(track_dir);
02175 
02176   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02177     /* Are we just leaving a tunnel/bridge? */
02178     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02179       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02180 
02181       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02182         /* Free the reservation only if no other train is on the tiles. */
02183         SetTunnelBridgeReservation(tile, false);
02184         SetTunnelBridgeReservation(end, false);
02185 
02186         if (_settings_client.gui.show_track_reservation) {
02187           MarkTileDirtyByTile(tile);
02188           MarkTileDirtyByTile(end);
02189         }
02190       }
02191     }
02192   } else if (IsRailStationTile(tile)) {
02193     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02194     /* If the new tile is not a further tile of the same station, we
02195      * clear the reservation for the whole platform. */
02196     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02197       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02198     }
02199   } else {
02200     /* Any other tile */
02201     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02202   }
02203 }
02204 
02211 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02212 {
02213   assert(v->IsFrontEngine());
02214 
02215   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02216   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02217   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02218   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02219 
02220   /* Can't be holding a reservation if we enter a depot. */
02221   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02222   if (v->track == TRACK_BIT_DEPOT) {
02223     /* Front engine is in a depot. We enter if some part is not in the depot. */
02224     for (const Train *u = v; u != NULL; u = u->Next()) {
02225       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02226     }
02227   }
02228   /* Don't free reservation if it's not ours. */
02229   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02230 
02231   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02232   while (ft.Follow(tile, td)) {
02233     tile = ft.m_new_tile;
02234     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02235     td = RemoveFirstTrackdir(&bits);
02236     assert(bits == TRACKDIR_BIT_NONE);
02237 
02238     if (!IsValidTrackdir(td)) break;
02239 
02240     if (IsTileType(tile, MP_RAILWAY)) {
02241       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02242         /* Conventional signal along trackdir: remove reservation and stop. */
02243         UnreserveRailTrack(tile, TrackdirToTrack(td));
02244         break;
02245       }
02246       if (HasPbsSignalOnTrackdir(tile, td)) {
02247         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02248           /* Red PBS signal? Can't be our reservation, would be green then. */
02249           break;
02250         } else {
02251           /* Turn the signal back to red. */
02252           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02253           MarkTileDirtyByTile(tile);
02254         }
02255       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02256         break;
02257       }
02258     }
02259 
02260     /* Don't free first station/bridge/tunnel if we are on it. */
02261     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);
02262 
02263     free_tile = true;
02264   }
02265 }
02266 
02267 static const byte _initial_tile_subcoord[6][4][3] = {
02268 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02269 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02270 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02271 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02272 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02273 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02274 };
02275 
02288 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02289 {
02290   switch (_settings_game.pf.pathfinder_for_trains) {
02291     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02292     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02293 
02294     default: NOT_REACHED();
02295   }
02296 }
02297 
02303 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02304 {
02305   PBSTileInfo origin = FollowTrainReservation(v);
02306 
02307   CFollowTrackRail ft(v);
02308 
02309   TileIndex tile = origin.tile;
02310   Trackdir  cur_td = origin.trackdir;
02311   while (ft.Follow(tile, cur_td)) {
02312     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02313       /* Possible signal tile. */
02314       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02315     }
02316 
02317     if (_settings_game.pf.forbid_90_deg) {
02318       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02319       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02320     }
02321 
02322     /* Station, depot or waypoint are a possible target. */
02323     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02324     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02325       /* Choice found or possible target encountered.
02326        * On finding a possible target, we need to stop and let the pathfinder handle the
02327        * remaining path. This is because we don't know if this target is in one of our
02328        * orders, so we might cause pathfinding to fail later on if we find a choice.
02329        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02330        * a wrong path not leading to our next destination. */
02331       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02332 
02333       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02334        * actually starts its search at the first unreserved tile. */
02335       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02336 
02337       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02338       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02339       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02340       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02341     }
02342 
02343     tile = ft.m_new_tile;
02344     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02345 
02346     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02347       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02348       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02349       /* Safe position is all good, path valid and okay. */
02350       return PBSTileInfo(tile, cur_td, true);
02351     }
02352 
02353     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02354   }
02355 
02356   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02357     /* End of line, path valid and okay. */
02358     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02359   }
02360 
02361   /* Sorry, can't reserve path, back out. */
02362   tile = origin.tile;
02363   cur_td = origin.trackdir;
02364   TileIndex stopped = ft.m_old_tile;
02365   Trackdir  stopped_td = ft.m_old_td;
02366   while (tile != stopped || cur_td != stopped_td) {
02367     if (!ft.Follow(tile, cur_td)) break;
02368 
02369     if (_settings_game.pf.forbid_90_deg) {
02370       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02371       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02372     }
02373     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02374 
02375     tile = ft.m_new_tile;
02376     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02377 
02378     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02379   }
02380 
02381   /* Path invalid. */
02382   return PBSTileInfo();
02383 }
02384 
02395 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02396 {
02397   switch (_settings_game.pf.pathfinder_for_trains) {
02398     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02399     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02400 
02401     default: NOT_REACHED();
02402   }
02403 }
02404 
02406 class VehicleOrderSaver {
02407 private:
02408   Train          *v;
02409   Order          old_order;
02410   TileIndex      old_dest_tile;
02411   StationID      old_last_station_visited;
02412   VehicleOrderID index;
02413   bool           suppress_implicit_orders;
02414 
02415 public:
02416   VehicleOrderSaver(Train *_v) :
02417     v(_v),
02418     old_order(_v->current_order),
02419     old_dest_tile(_v->dest_tile),
02420     old_last_station_visited(_v->last_station_visited),
02421     index(_v->cur_real_order_index),
02422     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02423   {
02424   }
02425 
02426   ~VehicleOrderSaver()
02427   {
02428     this->v->current_order = this->old_order;
02429     this->v->dest_tile = this->old_dest_tile;
02430     this->v->last_station_visited = this->old_last_station_visited;
02431     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02432   }
02433 
02439   bool SwitchToNextOrder(bool skip_first)
02440   {
02441     if (this->v->GetNumOrders() == 0) return false;
02442 
02443     if (skip_first) ++this->index;
02444 
02445     int depth = 0;
02446 
02447     do {
02448       /* Wrap around. */
02449       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02450 
02451       Order *order = this->v->GetOrder(this->index);
02452       assert(order != NULL);
02453 
02454       switch (order->GetType()) {
02455         case OT_GOTO_DEPOT:
02456           /* Skip service in depot orders when the train doesn't need service. */
02457           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02458         case OT_GOTO_STATION:
02459         case OT_GOTO_WAYPOINT:
02460           this->v->current_order = *order;
02461           return UpdateOrderDest(this->v, order, 0, true);
02462         case OT_CONDITIONAL: {
02463           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02464           if (next != INVALID_VEH_ORDER_ID) {
02465             depth++;
02466             this->index = next;
02467             /* Don't increment next, so no break here. */
02468             continue;
02469           }
02470           break;
02471         }
02472         default:
02473           break;
02474       }
02475       /* Don't increment inside the while because otherwise conditional
02476        * orders can lead to an infinite loop. */
02477       ++this->index;
02478       depth++;
02479     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02480 
02481     return false;
02482   }
02483 };
02484 
02485 /* choose a track */
02486 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02487 {
02488   Track best_track = INVALID_TRACK;
02489   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02490   bool changed_signal = false;
02491 
02492   assert((tracks & ~TRACK_BIT_MASK) == 0);
02493 
02494   if (got_reservation != NULL) *got_reservation = false;
02495 
02496   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02497   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02498   /* Do we have a suitable reserved track? */
02499   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02500 
02501   /* Quick return in case only one possible track is available */
02502   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02503     Track track = FindFirstTrack(tracks);
02504     /* We need to check for signals only here, as a junction tile can't have signals. */
02505     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02506       do_track_reservation = true;
02507       changed_signal = true;
02508       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02509     } else if (!do_track_reservation) {
02510       return track;
02511     }
02512     best_track = track;
02513   }
02514 
02515   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02516   DiagDirection dest_enterdir = enterdir;
02517   if (do_track_reservation) {
02518     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02519     if (res_dest.tile == INVALID_TILE) {
02520       /* Reservation failed? */
02521       if (mark_stuck) MarkTrainAsStuck(v);
02522       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02523       return FindFirstTrack(tracks);
02524     }
02525     if (res_dest.okay) {
02526       /* Got a valid reservation that ends at a safe target, quick exit. */
02527       if (got_reservation != NULL) *got_reservation = true;
02528       if (changed_signal) MarkTileDirtyByTile(tile);
02529       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02530       return best_track;
02531     }
02532 
02533     /* Check if the train needs service here, so it has a chance to always find a depot.
02534      * Also check if the current order is a service order so we don't reserve a path to
02535      * the destination but instead to the next one if service isn't needed. */
02536     CheckIfTrainNeedsService(v);
02537     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02538   }
02539 
02540   /* Save the current train order. The destructor will restore the old order on function exit. */
02541   VehicleOrderSaver orders(v);
02542 
02543   /* If the current tile is the destination of the current order and
02544    * a reservation was requested, advance to the next order.
02545    * Don't advance on a depot order as depots are always safe end points
02546    * for a path and no look-ahead is necessary. This also avoids a
02547    * problem with depot orders not part of the order list when the
02548    * order list itself is empty. */
02549   if (v->current_order.IsType(OT_LEAVESTATION)) {
02550     orders.SwitchToNextOrder(false);
02551   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02552       v->current_order.IsType(OT_GOTO_STATION) ?
02553       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02554       v->tile == v->dest_tile))) {
02555     orders.SwitchToNextOrder(true);
02556   }
02557 
02558   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02559     /* Pathfinders are able to tell that route was only 'guessed'. */
02560     bool      path_found = true;
02561     TileIndex new_tile = res_dest.tile;
02562 
02563     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02564     if (new_tile == tile) best_track = next_track;
02565     v->HandlePathfindingResult(path_found);
02566   }
02567 
02568   /* No track reservation requested -> finished. */
02569   if (!do_track_reservation) return best_track;
02570 
02571   /* A path was found, but could not be reserved. */
02572   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02573     if (mark_stuck) MarkTrainAsStuck(v);
02574     FreeTrainTrackReservation(v);
02575     return best_track;
02576   }
02577 
02578   /* No possible reservation target found, we are probably lost. */
02579   if (res_dest.tile == INVALID_TILE) {
02580     /* Try to find any safe destination. */
02581     PBSTileInfo origin = FollowTrainReservation(v);
02582     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02583       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02584       best_track = FindFirstTrack(res);
02585       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02586       if (got_reservation != NULL) *got_reservation = true;
02587       if (changed_signal) MarkTileDirtyByTile(tile);
02588     } else {
02589       FreeTrainTrackReservation(v);
02590       if (mark_stuck) MarkTrainAsStuck(v);
02591     }
02592     return best_track;
02593   }
02594 
02595   if (got_reservation != NULL) *got_reservation = true;
02596 
02597   /* Reservation target found and free, check if it is safe. */
02598   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02599     /* Extend reservation until we have found a safe position. */
02600     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02601     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02602     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02603     if (_settings_game.pf.forbid_90_deg) {
02604       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02605     }
02606 
02607     /* Get next order with destination. */
02608     if (orders.SwitchToNextOrder(true)) {
02609       PBSTileInfo cur_dest;
02610       bool path_found;
02611       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02612       if (cur_dest.tile != INVALID_TILE) {
02613         res_dest = cur_dest;
02614         if (res_dest.okay) continue;
02615         /* Path found, but could not be reserved. */
02616         FreeTrainTrackReservation(v);
02617         if (mark_stuck) MarkTrainAsStuck(v);
02618         if (got_reservation != NULL) *got_reservation = false;
02619         changed_signal = false;
02620         break;
02621       }
02622     }
02623     /* No order or no safe position found, try any position. */
02624     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02625       FreeTrainTrackReservation(v);
02626       if (mark_stuck) MarkTrainAsStuck(v);
02627       if (got_reservation != NULL) *got_reservation = false;
02628       changed_signal = false;
02629     }
02630     break;
02631   }
02632 
02633   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02634 
02635   if (changed_signal) MarkTileDirtyByTile(tile);
02636 
02637   return best_track;
02638 }
02639 
02648 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02649 {
02650   assert(v->IsFrontEngine());
02651 
02652   /* We have to handle depots specially as the track follower won't look
02653    * at the depot tile itself but starts from the next tile. If we are still
02654    * inside the depot, a depot reservation can never be ours. */
02655   if (v->track == TRACK_BIT_DEPOT) {
02656     if (HasDepotReservation(v->tile)) {
02657       if (mark_as_stuck) MarkTrainAsStuck(v);
02658       return false;
02659     } else {
02660       /* Depot not reserved, but the next tile might be. */
02661       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02662       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02663     }
02664   }
02665 
02666   Vehicle *other_train = NULL;
02667   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02668   /* The path we are driving on is already blocked by some other train.
02669    * This can only happen in certain situations when mixing path and
02670    * block signals or when changing tracks and/or signals.
02671    * Exit here as doing any further reservations will probably just
02672    * make matters worse. */
02673   if (other_train != NULL && other_train->index != v->index) {
02674     if (mark_as_stuck) MarkTrainAsStuck(v);
02675     return false;
02676   }
02677   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02678   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02679     /* Can't be stuck then. */
02680     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02681     ClrBit(v->flags, VRF_TRAIN_STUCK);
02682     return true;
02683   }
02684 
02685   /* If we are in a depot, tentatively reserve the depot. */
02686   if (v->track == TRACK_BIT_DEPOT) {
02687     SetDepotReservation(v->tile, true);
02688     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02689   }
02690 
02691   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02692   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02693   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02694 
02695   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02696 
02697   bool res_made = false;
02698   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02699 
02700   if (!res_made) {
02701     /* Free the depot reservation as well. */
02702     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02703     return false;
02704   }
02705 
02706   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02707     v->wait_counter = 0;
02708     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02709   }
02710   ClrBit(v->flags, VRF_TRAIN_STUCK);
02711   return true;
02712 }
02713 
02714 
02715 static bool CheckReverseTrain(const Train *v)
02716 {
02717   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02718       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02719       !(v->direction & 1)) {
02720     return false;
02721   }
02722 
02723   assert(v->track != TRACK_BIT_NONE);
02724 
02725   switch (_settings_game.pf.pathfinder_for_trains) {
02726     case VPF_NPF: return NPFTrainCheckReverse(v);
02727     case VPF_YAPF: return YapfTrainCheckReverse(v);
02728 
02729     default: NOT_REACHED();
02730   }
02731 }
02732 
02738 TileIndex Train::GetOrderStationLocation(StationID station)
02739 {
02740   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02741 
02742   const Station *st = Station::Get(station);
02743   if (!(st->facilities & FACIL_TRAIN)) {
02744     /* The destination station has no trainstation tiles. */
02745     this->IncrementRealOrderIndex();
02746     return 0;
02747   }
02748 
02749   return st->xy;
02750 }
02751 
02753 void Train::MarkDirty()
02754 {
02755   Train *v = this;
02756   do {
02757     v->UpdateViewport(false, false);
02758   } while ((v = v->Next()) != NULL);
02759 
02760   /* need to update acceleration and cached values since the goods on the train changed. */
02761   this->CargoChanged();
02762   this->UpdateAcceleration();
02763 }
02764 
02772 int Train::UpdateSpeed()
02773 {
02774   switch (_settings_game.vehicle.train_acceleration_model) {
02775     default: NOT_REACHED();
02776     case AM_ORIGINAL:
02777       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, min(this->gcache.cached_max_track_speed, this->current_order.max_speed));
02778 
02779     case AM_REALISTIC:
02780       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02781   }
02782 }
02783 
02789 static void TrainEnterStation(Train *v, StationID station)
02790 {
02791   v->last_station_visited = station;
02792 
02793   /* check if a train ever visited this station before */
02794   Station *st = Station::Get(station);
02795   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02796     st->had_vehicle_of_type |= HVOT_TRAIN;
02797     SetDParam(0, st->index);
02798     AddVehicleNewsItem(
02799       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02800       v->owner == _local_company ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
02801       v->index,
02802       st->index
02803     );
02804     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02805     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02806   }
02807 
02808   v->force_proceed = TFP_NONE;
02809   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02810 
02811   v->BeginLoading();
02812 
02813   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02814 }
02815 
02816 /* Check if the vehicle is compatible with the specified tile */
02817 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02818 {
02819   return IsTileOwner(tile, v->owner) &&
02820       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02821 }
02822 
02824 struct AccelerationSlowdownParams {
02825   byte small_turn; 
02826   byte large_turn; 
02827   byte z_up;       
02828   byte z_down;     
02829 };
02830 
02832 static const AccelerationSlowdownParams _accel_slowdown[] = {
02833   /* normal accel */
02834   {256 / 4, 256 / 2, 256 / 4, 2}, 
02835   {256 / 4, 256 / 2, 256 / 4, 2}, 
02836   {0,       256 / 2, 256 / 4, 2}, 
02837 };
02838 
02844 static inline void AffectSpeedByZChange(Train *v, int old_z)
02845 {
02846   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02847 
02848   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02849 
02850   if (old_z < v->z_pos) {
02851     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02852   } else {
02853     uint16 spd = v->cur_speed + asp->z_down;
02854     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02855   }
02856 }
02857 
02858 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02859 {
02860   if (IsTileType(tile, MP_RAILWAY) &&
02861       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02862     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02863     Trackdir trackdir = FindFirstTrackdir(tracks);
02864     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02865       /* A PBS block with a non-PBS signal facing us? */
02866       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02867     }
02868   }
02869   return false;
02870 }
02871 
02873 void Train::ReserveTrackUnderConsist() const
02874 {
02875   for (const Train *u = this; u != NULL; u = u->Next()) {
02876     switch (u->track) {
02877       case TRACK_BIT_WORMHOLE:
02878         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02879         break;
02880       case TRACK_BIT_DEPOT:
02881         break;
02882       default:
02883         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02884         break;
02885     }
02886   }
02887 }
02888 
02895 uint Train::Crash(bool flooded)
02896 {
02897   uint pass = 0;
02898   if (this->IsFrontEngine()) {
02899     pass += 2; // driver
02900 
02901     /* Remove the reserved path in front of the train if it is not stuck.
02902      * Also clear all reserved tracks the train is currently on. */
02903     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02904     for (const Train *v = this; v != NULL; v = v->Next()) {
02905       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02906       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02907         /* ClearPathReservation will not free the wormhole exit
02908          * if the train has just entered the wormhole. */
02909         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02910       }
02911     }
02912 
02913     /* we may need to update crossing we were approaching,
02914      * but must be updated after the train has been marked crashed */
02915     TileIndex crossing = TrainApproachingCrossingTile(this);
02916     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02917 
02918     /* Remove the loading indicators (if any) */
02919     HideFillingPercent(&this->fill_percent_te_id);
02920   }
02921 
02922   pass += this->GroundVehicleBase::Crash(flooded);
02923 
02924   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02925   return pass;
02926 }
02927 
02934 static uint TrainCrashed(Train *v)
02935 {
02936   uint num = 0;
02937 
02938   /* do not crash train twice */
02939   if (!(v->vehstatus & VS_CRASHED)) {
02940     num = v->Crash();
02941     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02942     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02943   }
02944 
02945   /* Try to re-reserve track under already crashed train too.
02946    * Crash() clears the reservation! */
02947   v->ReserveTrackUnderConsist();
02948 
02949   return num;
02950 }
02951 
02953 struct TrainCollideChecker {
02954   Train *v; 
02955   uint num; 
02956 };
02957 
02964 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02965 {
02966   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02967 
02968   /* not a train or in depot */
02969   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02970 
02971   /* do not crash into trains of another company. */
02972   if (v->owner != tcc->v->owner) return NULL;
02973 
02974   /* get first vehicle now to make most usual checks faster */
02975   Train *coll = Train::From(v)->First();
02976 
02977   /* can't collide with own wagons */
02978   if (coll == tcc->v) return NULL;
02979 
02980   int x_diff = v->x_pos - tcc->v->x_pos;
02981   int y_diff = v->y_pos - tcc->v->y_pos;
02982 
02983   /* Do fast calculation to check whether trains are not in close vicinity
02984    * and quickly reject trains distant enough for any collision.
02985    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02986    * Differences are then ORed and then we check for any higher bits */
02987   uint hash = (y_diff + 7) | (x_diff + 7);
02988   if (hash & ~15) return NULL;
02989 
02990   /* Slower check using multiplication */
02991   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02992   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02993 
02994   /* Happens when there is a train under bridge next to bridge head */
02995   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02996 
02997   /* crash both trains */
02998   tcc->num += TrainCrashed(tcc->v);
02999   tcc->num += TrainCrashed(coll);
03000 
03001   return NULL; // continue searching
03002 }
03003 
03011 static bool CheckTrainCollision(Train *v)
03012 {
03013   /* can't collide in depot */
03014   if (v->track == TRACK_BIT_DEPOT) return false;
03015 
03016   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03017 
03018   TrainCollideChecker tcc;
03019   tcc.v = v;
03020   tcc.num = 0;
03021 
03022   /* find colliding vehicles */
03023   if (v->track == TRACK_BIT_WORMHOLE) {
03024     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03025     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03026   } else {
03027     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03028   }
03029 
03030   /* any dead -> no crash */
03031   if (tcc.num == 0) return false;
03032 
03033   SetDParam(0, tcc.num);
03034   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH, NT_ACCIDENT, v->index);
03035 
03036   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03037   if (_settings_client.sound.disaster) SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03038   return true;
03039 }
03040 
03041 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03042 {
03043   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03044 
03045   Train *t = Train::From(v);
03046   DiagDirection exitdir = *(DiagDirection *)data;
03047 
03048   /* not front engine of a train, inside wormhole or depot, crashed */
03049   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03050 
03051   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03052 
03053   return t;
03054 }
03055 
03063 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03064 {
03065   Train *first = v->First();
03066   Train *prev;
03067   bool direction_changed = false; // has direction of any part changed?
03068 
03069   /* For every vehicle after and including the given vehicle */
03070   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03071     DiagDirection enterdir = DIAGDIR_BEGIN;
03072     bool update_signals_crossing = false; // will we update signals or crossing state?
03073 
03074     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03075     if (v->track != TRACK_BIT_WORMHOLE) {
03076       /* Not inside tunnel */
03077       if (gp.old_tile == gp.new_tile) {
03078         /* Staying in the old tile */
03079         if (v->track == TRACK_BIT_DEPOT) {
03080           /* Inside depot */
03081           gp.x = v->x_pos;
03082           gp.y = v->y_pos;
03083         } else {
03084           /* Not inside depot */
03085 
03086           /* Reverse when we are at the end of the track already, do not move to the new position */
03087           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03088 
03089           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03090           if (HasBit(r, VETS_CANNOT_ENTER)) {
03091             goto invalid_rail;
03092           }
03093           if (HasBit(r, VETS_ENTERED_STATION)) {
03094             /* The new position is the end of the platform */
03095             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03096           }
03097         }
03098       } else {
03099         /* A new tile is about to be entered. */
03100 
03101         /* Determine what direction we're entering the new tile from */
03102         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03103         assert(IsValidDiagDirection(enterdir));
03104 
03105         /* Get the status of the tracks in the new tile and mask
03106          * away the bits that aren't reachable. */
03107         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03108         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03109 
03110         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03111         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03112 
03113         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03114         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03115           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03116            * can be switched on halfway a turn */
03117           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03118         }
03119 
03120         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03121 
03122         /* Check if the new tile constrains tracks that are compatible
03123          * with the current train, if not, bail out. */
03124         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03125 
03126         TrackBits chosen_track;
03127         if (prev == NULL) {
03128           /* Currently the locomotive is active. Determine which one of the
03129            * available tracks to choose */
03130           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03131           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03132 
03133           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03134             /* For each signal we find decrease the counter by one.
03135              * We start at two, so the first signal we pass decreases
03136              * this to one, then if we reach the next signal it is
03137              * decreased to zero and we won't pass that new signal. */
03138             Trackdir dir = FindFirstTrackdir(trackdirbits);
03139             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03140                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03141               /* However, we do not want to be stopped by PBS signals
03142                * entered via the back. */
03143               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03144               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03145             }
03146           }
03147 
03148           /* Check if it's a red signal and that force proceed is not clicked. */
03149           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03150             /* In front of a red signal */
03151             Trackdir i = FindFirstTrackdir(trackdirbits);
03152 
03153             /* Don't handle stuck trains here. */
03154             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03155 
03156             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03157               v->cur_speed = 0;
03158               v->subspeed = 0;
03159               v->progress = 255 - 100;
03160               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03161             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03162               v->cur_speed = 0;
03163               v->subspeed = 0;
03164               v->progress = 255 - 10;
03165               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03166                 DiagDirection exitdir = TrackdirToExitdir(i);
03167                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03168 
03169                 exitdir = ReverseDiagDir(exitdir);
03170 
03171                 /* check if a train is waiting on the other side */
03172                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03173               }
03174             }
03175 
03176             /* If we would reverse but are currently in a PBS block and
03177              * reversing of stuck trains is disabled, don't reverse.
03178              * This does not apply if the reason for reversing is a one-way
03179              * signal blocking us, because a train would then be stuck forever. */
03180             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03181                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03182               v->wait_counter = 0;
03183               return false;
03184             }
03185             goto reverse_train_direction;
03186           } else {
03187             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03188           }
03189         } else {
03190           /* The wagon is active, simply follow the prev vehicle. */
03191           if (prev->tile == gp.new_tile) {
03192             /* Choose the same track as prev */
03193             if (prev->track == TRACK_BIT_WORMHOLE) {
03194               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03195                * However, just choose the track into the wormhole. */
03196               assert(IsTunnel(prev->tile));
03197               chosen_track = bits;
03198             } else {
03199               chosen_track = prev->track;
03200             }
03201           } else {
03202             /* Choose the track that leads to the tile where prev is.
03203              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03204              * I.e. when the tile between them has only space for a single vehicle like
03205              *  1) horizontal/vertical track tiles and
03206              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03207              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03208              */
03209             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03210               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03211               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03212               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03213               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03214             };
03215             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03216             assert(IsValidDiagDirection(exitdir));
03217             chosen_track = _connecting_track[enterdir][exitdir];
03218           }
03219           chosen_track &= bits;
03220         }
03221 
03222         /* Make sure chosen track is a valid track */
03223         assert(
03224             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03225             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03226             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03227 
03228         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03229         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03230         gp.x = (gp.x & ~0xF) | b[0];
03231         gp.y = (gp.y & ~0xF) | b[1];
03232         Direction chosen_dir = (Direction)b[2];
03233 
03234         /* Call the landscape function and tell it that the vehicle entered the tile */
03235         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03236         if (HasBit(r, VETS_CANNOT_ENTER)) {
03237           goto invalid_rail;
03238         }
03239 
03240         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03241           Track track = FindFirstTrack(chosen_track);
03242           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03243           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03244             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03245             MarkTileDirtyByTile(gp.new_tile);
03246           }
03247 
03248           /* Clear any track reservation when the last vehicle leaves the tile */
03249           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03250 
03251           v->tile = gp.new_tile;
03252 
03253           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03254             v->First()->ConsistChanged(true);
03255           }
03256 
03257           v->track = chosen_track;
03258           assert(v->track);
03259         }
03260 
03261         /* We need to update signal status, but after the vehicle position hash
03262          * has been updated by UpdateInclination() */
03263         update_signals_crossing = true;
03264 
03265         if (chosen_dir != v->direction) {
03266           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03267             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03268             DirDiff diff = DirDifference(v->direction, chosen_dir);
03269             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03270           }
03271           direction_changed = true;
03272           v->direction = chosen_dir;
03273         }
03274 
03275         if (v->IsFrontEngine()) {
03276           v->wait_counter = 0;
03277 
03278           /* If we are approaching a crossing that is reserved, play the sound now. */
03279           TileIndex crossing = TrainApproachingCrossingTile(v);
03280           if (crossing != INVALID_TILE && HasCrossingReservation(crossing) && _settings_client.sound.new_year) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03281 
03282           /* Always try to extend the reservation when entering a tile. */
03283           CheckNextTrainTile(v);
03284         }
03285 
03286         if (HasBit(r, VETS_ENTERED_STATION)) {
03287           /* The new position is the location where we want to stop */
03288           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03289         }
03290       }
03291     } else {
03292       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03293         /* Perform look-ahead on tunnel exit. */
03294         if (v->IsFrontEngine()) {
03295           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03296           CheckNextTrainTile(v);
03297         }
03298         /* Prevent v->UpdateInclination() being called with wrong parameters.
03299          * This could happen if the train was reversed inside the tunnel/bridge. */
03300         if (gp.old_tile == gp.new_tile) {
03301           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03302         }
03303       } else {
03304         v->x_pos = gp.x;
03305         v->y_pos = gp.y;
03306         VehicleUpdatePosition(v);
03307         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03308         continue;
03309       }
03310     }
03311 
03312     /* update image of train, as well as delta XY */
03313     v->UpdateDeltaXY(v->direction);
03314 
03315     v->x_pos = gp.x;
03316     v->y_pos = gp.y;
03317     VehicleUpdatePosition(v);
03318 
03319     /* update the Z position of the vehicle */
03320     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03321 
03322     if (prev == NULL) {
03323       /* This is the first vehicle in the train */
03324       AffectSpeedByZChange(v, old_z);
03325     }
03326 
03327     if (update_signals_crossing) {
03328       if (v->IsFrontEngine()) {
03329         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03330           /* We are entering a block with PBS signals right now, but
03331            * not through a PBS signal. This means we don't have a
03332            * reservation right now. As a conventional signal will only
03333            * ever be green if no other train is in the block, getting
03334            * a path should always be possible. If the player built
03335            * such a strange network that it is not possible, the train
03336            * will be marked as stuck and the player has to deal with
03337            * the problem. */
03338           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03339               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03340               !TryPathReserve(v)) {
03341             MarkTrainAsStuck(v);
03342           }
03343         }
03344       }
03345 
03346       /* Signals can only change when the first
03347        * (above) or the last vehicle moves. */
03348       if (v->Next() == NULL) {
03349         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03350         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03351       }
03352     }
03353 
03354     /* Do not check on every tick to save some computing time. */
03355     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03356   }
03357 
03358   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03359 
03360   return true;
03361 
03362 invalid_rail:
03363   /* We've reached end of line?? */
03364   if (prev != NULL) error("Disconnecting train");
03365 
03366 reverse_train_direction:
03367   if (reverse) {
03368     v->wait_counter = 0;
03369     v->cur_speed = 0;
03370     v->subspeed = 0;
03371     ReverseTrainDirection(v);
03372   }
03373 
03374   return false;
03375 }
03376 
03383 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03384 {
03385   TrackBits *trackbits = (TrackBits *)data;
03386 
03387   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03388     TrackBits train_tbits = Train::From(v)->track;
03389     if (train_tbits == TRACK_BIT_WORMHOLE) {
03390       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03391       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03392     } else if (train_tbits != TRACK_BIT_DEPOT) {
03393       *trackbits |= train_tbits;
03394     }
03395   }
03396 
03397   return NULL;
03398 }
03399 
03407 static void DeleteLastWagon(Train *v)
03408 {
03409   Train *first = v->First();
03410 
03411   /* Go to the last wagon and delete the link pointing there
03412    * *u is then the one-before-last wagon, and *v the last
03413    * one which will physically be removed */
03414   Train *u = v;
03415   for (; v->Next() != NULL; v = v->Next()) u = v;
03416   u->SetNext(NULL);
03417 
03418   if (first != v) {
03419     /* Recalculate cached train properties */
03420     first->ConsistChanged(false);
03421     /* Update the depot window if the first vehicle is in depot -
03422      * if v == first, then it is updated in PreDestructor() */
03423     if (first->track == TRACK_BIT_DEPOT) {
03424       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03425     }
03426   }
03427 
03428   /* 'v' shouldn't be accessed after it has been deleted */
03429   TrackBits trackbits = v->track;
03430   TileIndex tile = v->tile;
03431   Owner owner = v->owner;
03432 
03433   delete v;
03434   v = NULL; // make sure nobody will try to read 'v' anymore
03435 
03436   if (trackbits == TRACK_BIT_WORMHOLE) {
03437     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03438     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03439   }
03440 
03441   Track track = TrackBitsToTrack(trackbits);
03442   if (HasReservedTracks(tile, trackbits)) {
03443     UnreserveRailTrack(tile, track);
03444 
03445     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03446     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03447     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03448 
03449     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03450     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03451     Track t;
03452     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03453   }
03454 
03455   /* check if the wagon was on a road/rail-crossing */
03456   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03457 
03458   /* Update signals */
03459   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03460     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03461   } else {
03462     SetSignalsOnBothDir(tile, track, owner);
03463   }
03464 }
03465 
03470 static void ChangeTrainDirRandomly(Train *v)
03471 {
03472   static const DirDiff delta[] = {
03473     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03474   };
03475 
03476   do {
03477     /* We don't need to twist around vehicles if they're not visible */
03478     if (!(v->vehstatus & VS_HIDDEN)) {
03479       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03480       v->UpdateDeltaXY(v->direction);
03481       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03482       /* Refrain from updating the z position of the vehicle when on
03483        * a bridge, because UpdateInclination() will put the vehicle under
03484        * the bridge in that case */
03485       if (v->track != TRACK_BIT_WORMHOLE) {
03486         VehicleUpdatePosition(v);
03487         v->UpdateInclination(false, false);
03488       }
03489     }
03490   } while ((v = v->Next()) != NULL);
03491 }
03492 
03498 static bool HandleCrashedTrain(Train *v)
03499 {
03500   int state = ++v->crash_anim_pos;
03501 
03502   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03503     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03504   }
03505 
03506   uint32 r;
03507   if (state <= 200 && Chance16R(1, 7, r)) {
03508     int index = (r * 10 >> 16);
03509 
03510     Vehicle *u = v;
03511     do {
03512       if (--index < 0) {
03513         r = Random();
03514 
03515         CreateEffectVehicleRel(u,
03516           GB(r,  8, 3) + 2,
03517           GB(r, 16, 3) + 2,
03518           GB(r,  0, 3) + 5,
03519           EV_EXPLOSION_SMALL);
03520         break;
03521       }
03522     } while ((u = u->Next()) != NULL);
03523   }
03524 
03525   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03526 
03527   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03528     bool ret = v->Next() != NULL;
03529     DeleteLastWagon(v);
03530     return ret;
03531   }
03532 
03533   return true;
03534 }
03535 
03537 static const uint16 _breakdown_speeds[16] = {
03538   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03539 };
03540 
03541 
03550 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03551 {
03552   /* Calc position within the current tile */
03553   uint x = v->x_pos & 0xF;
03554   uint y = v->y_pos & 0xF;
03555 
03556   /* for diagonal directions, 'x' will be 0..15 -
03557    * for other directions, it will be 1, 3, 5, ..., 15 */
03558   switch (v->direction) {
03559     case DIR_N : x = ~x + ~y + 25; break;
03560     case DIR_NW: x = y;            // FALL THROUGH
03561     case DIR_NE: x = ~x + 16;      break;
03562     case DIR_E : x = ~x + y + 9;   break;
03563     case DIR_SE: x = y;            break;
03564     case DIR_S : x = x + y - 7;    break;
03565     case DIR_W : x = ~y + x + 9;   break;
03566     default: break;
03567   }
03568 
03569   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03570    * does not cross the tile boundary when we do reverse, but as the vehicle's
03571    * location is based on their center, use half a vehicle's length as offset.
03572    * Multiply the half-length by two for straight directions to compensate that
03573    * we only get odd x offsets there. */
03574   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03575     /* we are too near the tile end, reverse now */
03576     v->cur_speed = 0;
03577     if (reverse) ReverseTrainDirection(v);
03578     return false;
03579   }
03580 
03581   /* slow down */
03582   v->vehstatus |= VS_TRAIN_SLOWING;
03583   uint16 break_speed = _breakdown_speeds[x & 0xF];
03584   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03585 
03586   return true;
03587 }
03588 
03589 
03595 static bool TrainCanLeaveTile(const Train *v)
03596 {
03597   /* Exit if inside a tunnel/bridge or a depot */
03598   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03599 
03600   TileIndex tile = v->tile;
03601 
03602   /* entering a tunnel/bridge? */
03603   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03604     DiagDirection dir = GetTunnelBridgeDirection(tile);
03605     if (DiagDirToDir(dir) == v->direction) return false;
03606   }
03607 
03608   /* entering a depot? */
03609   if (IsRailDepotTile(tile)) {
03610     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03611     if (DiagDirToDir(dir) == v->direction) return false;
03612   }
03613 
03614   return true;
03615 }
03616 
03617 
03625 static TileIndex TrainApproachingCrossingTile(const Train *v)
03626 {
03627   assert(v->IsFrontEngine());
03628   assert(!(v->vehstatus & VS_CRASHED));
03629 
03630   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03631 
03632   DiagDirection dir = TrainExitDir(v->direction, v->track);
03633   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03634 
03635   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03636   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03637       !CheckCompatibleRail(v, tile)) {
03638     return INVALID_TILE;
03639   }
03640 
03641   return tile;
03642 }
03643 
03644 
03652 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03653 {
03654   /* First, handle broken down train */
03655 
03656   int t = v->breakdown_ctr;
03657   if (t > 1) {
03658     v->vehstatus |= VS_TRAIN_SLOWING;
03659 
03660     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03661     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03662   } else {
03663     v->vehstatus &= ~VS_TRAIN_SLOWING;
03664   }
03665 
03666   if (!TrainCanLeaveTile(v)) return true;
03667 
03668   /* Determine the non-diagonal direction in which we will exit this tile */
03669   DiagDirection dir = TrainExitDir(v->direction, v->track);
03670   /* Calculate next tile */
03671   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03672 
03673   /* Determine the track status on the next tile */
03674   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03675   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03676 
03677   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03678   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03679 
03680   /* We are sure the train is not entering a depot, it is detected above */
03681 
03682   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03683   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03684   if (_settings_game.pf.forbid_90_deg) {
03685     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03686   }
03687 
03688   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03689   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03690     return TrainApproachingLineEnd(v, false, reverse);
03691   }
03692 
03693   /* approaching red signal */
03694   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03695 
03696   /* approaching a rail/road crossing? then make it red */
03697   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03698 
03699   return true;
03700 }
03701 
03702 
03703 static bool TrainLocoHandler(Train *v, bool mode)
03704 {
03705   /* train has crashed? */
03706   if (v->vehstatus & VS_CRASHED) {
03707     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03708   }
03709 
03710   if (v->force_proceed != TFP_NONE) {
03711     ClrBit(v->flags, VRF_TRAIN_STUCK);
03712     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03713   }
03714 
03715   /* train is broken down? */
03716   if (v->HandleBreakdown()) return true;
03717 
03718   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03719     ReverseTrainDirection(v);
03720   }
03721 
03722   /* exit if train is stopped */
03723   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03724 
03725   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03726   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03727     v->wait_counter = 0;
03728     v->cur_speed = 0;
03729     v->subspeed = 0;
03730     ClrBit(v->flags, VRF_LEAVING_STATION);
03731     ReverseTrainDirection(v);
03732     return true;
03733   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03734     /* Try to reserve a path when leaving the station as we
03735      * might not be marked as wanting a reservation, e.g.
03736      * when an overlength train gets turned around in a station. */
03737     DiagDirection dir = TrainExitDir(v->direction, v->track);
03738     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03739 
03740     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03741       TryPathReserve(v, true, true);
03742     }
03743     ClrBit(v->flags, VRF_LEAVING_STATION);
03744   }
03745 
03746   v->HandleLoading(mode);
03747 
03748   if (v->current_order.IsType(OT_LOADING)) return true;
03749 
03750   if (CheckTrainStayInDepot(v)) return true;
03751 
03752   if (!mode) v->ShowVisualEffect();
03753 
03754   /* We had no order but have an order now, do look ahead. */
03755   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03756     CheckNextTrainTile(v);
03757   }
03758 
03759   /* Handle stuck trains. */
03760   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03761     ++v->wait_counter;
03762 
03763     /* Should we try reversing this tick if still stuck? */
03764     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03765 
03766     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03767     if (!TryPathReserve(v)) {
03768       /* Still stuck. */
03769       if (turn_around) ReverseTrainDirection(v);
03770 
03771       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03772         /* Show message to player. */
03773         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03774           SetDParam(0, v->index);
03775           AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_STUCK, v->index);
03776         }
03777         v->wait_counter = 0;
03778       }
03779       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03780       if (v->force_proceed == TFP_NONE) return true;
03781       ClrBit(v->flags, VRF_TRAIN_STUCK);
03782       v->wait_counter = 0;
03783       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03784     }
03785   }
03786 
03787   if (v->current_order.IsType(OT_LEAVESTATION)) {
03788     v->current_order.Free();
03789     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03790     return true;
03791   }
03792 
03793   int j = v->UpdateSpeed();
03794 
03795   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03796   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03797     /* If we manually stopped, we're not force-proceeding anymore. */
03798     v->force_proceed = TFP_NONE;
03799     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03800   }
03801 
03802   int adv_spd = v->GetAdvanceDistance();
03803   if (j < adv_spd) {
03804     /* if the vehicle has speed 0, update the last_speed field. */
03805     if (v->cur_speed == 0) v->SetLastSpeed();
03806   } else {
03807     TrainCheckIfLineEnds(v);
03808     /* Loop until the train has finished moving. */
03809     for (;;) {
03810       j -= adv_spd;
03811       TrainController(v, NULL);
03812       /* Don't continue to move if the train crashed. */
03813       if (CheckTrainCollision(v)) break;
03814       /* Determine distance to next map position */
03815       adv_spd = v->GetAdvanceDistance();
03816 
03817       /* No more moving this tick */
03818       if (j < adv_spd || v->cur_speed == 0) break;
03819 
03820       OrderType order_type = v->current_order.GetType();
03821       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03822       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03823             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03824             IsTileType(v->tile, MP_STATION) &&
03825             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03826         ProcessOrders(v);
03827       }
03828     }
03829     v->SetLastSpeed();
03830   }
03831 
03832   for (Train *u = v; u != NULL; u = u->Next()) {
03833     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03834 
03835     u->UpdateViewport(false, false);
03836   }
03837 
03838   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03839 
03840   return true;
03841 }
03842 
03847 Money Train::GetRunningCost() const
03848 {
03849   Money cost = 0;
03850   const Train *v = this;
03851 
03852   do {
03853     const Engine *e = v->GetEngine();
03854     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03855 
03856     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03857     if (cost_factor == 0) continue;
03858 
03859     /* Halve running cost for multiheaded parts */
03860     if (v->IsMultiheaded()) cost_factor /= 2;
03861 
03862     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03863   } while ((v = v->GetNextVehicle()) != NULL);
03864 
03865   return cost;
03866 }
03867 
03872 bool Train::Tick()
03873 {
03874   this->tick_counter++;
03875 
03876   if (this->IsFrontEngine()) {
03877     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03878 
03879     this->current_order_time++;
03880 
03881     if (!TrainLocoHandler(this, false)) return false;
03882 
03883     return TrainLocoHandler(this, true);
03884   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03885     /* Delete flooded standalone wagon chain */
03886     if (++this->crash_anim_pos >= 4400) {
03887       delete this;
03888       return false;
03889     }
03890   }
03891 
03892   return true;
03893 }
03894 
03899 static void CheckIfTrainNeedsService(Train *v)
03900 {
03901   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03902   if (v->IsChainInDepot()) {
03903     VehicleServiceInDepot(v);
03904     return;
03905   }
03906 
03907   uint max_penalty;
03908   switch (_settings_game.pf.pathfinder_for_trains) {
03909     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03910     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03911     default: NOT_REACHED();
03912   }
03913 
03914   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03915   /* Only go to the depot if it is not too far out of our way. */
03916   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03917     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03918       /* If we were already heading for a depot but it has
03919        * suddenly moved farther away, we continue our normal
03920        * schedule? */
03921       v->current_order.MakeDummy();
03922       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03923     }
03924     return;
03925   }
03926 
03927   DepotID depot = GetDepotIndex(tfdd.tile);
03928 
03929   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03930       v->current_order.GetDestination() != depot &&
03931       !Chance16(3, 16)) {
03932     return;
03933   }
03934 
03935   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03936   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03937   v->dest_tile = tfdd.tile;
03938   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03939 }
03940 
03942 void Train::OnNewDay()
03943 {
03944   AgeVehicle(this);
03945 
03946   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03947 
03948   if (this->IsFrontEngine()) {
03949     CheckVehicleBreakdown(this);
03950 
03951     CheckIfTrainNeedsService(this);
03952 
03953     CheckOrders(this);
03954 
03955     /* update destination */
03956     if (this->current_order.IsType(OT_GOTO_STATION)) {
03957       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03958       if (tile != INVALID_TILE) this->dest_tile = tile;
03959     }
03960 
03961     if (this->running_ticks != 0) {
03962       /* running costs */
03963       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03964 
03965       this->profit_this_year -= cost.GetCost();
03966       this->running_ticks = 0;
03967 
03968       SubtractMoneyFromCompanyFract(this->owner, cost);
03969 
03970       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03971       SetWindowClassesDirty(WC_TRAINS_LIST);
03972     }
03973   }
03974 }
03975 
03980 Trackdir Train::GetVehicleTrackdir() const
03981 {
03982   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03983 
03984   if (this->track == TRACK_BIT_DEPOT) {
03985     /* We'll assume the train is facing outwards */
03986     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03987   }
03988 
03989   if (this->track == TRACK_BIT_WORMHOLE) {
03990     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03991     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03992   }
03993 
03994   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03995 }