train_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "error.h"
00014 #include "articulated_vehicles.h"
00015 #include "command_func.h"
00016 #include "pathfinder/npf/npf_func.h"
00017 #include "pathfinder/yapf/yapf.hpp"
00018 #include "news_func.h"
00019 #include "company_func.h"
00020 #include "newgrf_sound.h"
00021 #include "newgrf_text.h"
00022 #include "strings_func.h"
00023 #include "viewport_func.h"
00024 #include "vehicle_func.h"
00025 #include "sound_func.h"
00026 #include "ai/ai.hpp"
00027 #include "game/game.hpp"
00028 #include "newgrf_station.h"
00029 #include "effectvehicle_func.h"
00030 #include "network/network.h"
00031 #include "spritecache.h"
00032 #include "core/random_func.hpp"
00033 #include "company_base.h"
00034 #include "newgrf.h"
00035 #include "order_backup.h"
00036 #include "zoom_func.h"
00037 
00038 #include "table/strings.h"
00039 #include "table/train_cmd.h"
00040 
00041 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00042 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00043 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00044 static TileIndex TrainApproachingCrossingTile(const Train *v);
00045 static void CheckIfTrainNeedsService(Train *v);
00046 static void CheckNextTrainTile(Train *v);
00047 
00048 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00049 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00050 
00051 
00059 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00060 {
00061   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00062 
00063   DiagDirection diagdir = DirToDiagDir(direction);
00064 
00065   /* Determine the diagonal direction in which we will exit this tile */
00066   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00067     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00068   }
00069 
00070   return diagdir;
00071 }
00072 
00073 
00079 byte FreightWagonMult(CargoID cargo)
00080 {
00081   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00082   return _settings_game.vehicle.freight_trains;
00083 }
00084 
00086 void CheckTrainsLengths()
00087 {
00088   const Train *v;
00089   bool first = true;
00090 
00091   FOR_ALL_TRAINS(v) {
00092     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00093       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00094         if (u->track != TRACK_BIT_DEPOT) {
00095           if ((w->track != TRACK_BIT_DEPOT &&
00096               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00097               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00098             SetDParam(0, v->index);
00099             SetDParam(1, v->owner);
00100             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00101 
00102             if (!_networking && first) {
00103               first = false;
00104               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00105             }
00106             /* Break so we warn only once for each train. */
00107             break;
00108           }
00109         }
00110       }
00111     }
00112   }
00113 }
00114 
00121 void Train::ConsistChanged(bool same_length)
00122 {
00123   uint16 max_speed = UINT16_MAX;
00124 
00125   assert(this->IsFrontEngine() || this->IsFreeWagon());
00126 
00127   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00128   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00129   this->gcache.cached_total_length = 0;
00130   this->compatible_railtypes = RAILTYPES_NONE;
00131 
00132   bool train_can_tilt = true;
00133 
00134   for (Train *u = this; u != NULL; u = u->Next()) {
00135     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00136 
00137     /* Check the this->first cache. */
00138     assert(u->First() == this);
00139 
00140     /* update the 'first engine' */
00141     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00142     u->railtype = rvi_u->railtype;
00143 
00144     if (u->IsEngine()) first_engine = u->engine_type;
00145 
00146     /* Set user defined data to its default value */
00147     u->tcache.user_def_data = rvi_u->user_def_data;
00148     this->InvalidateNewGRFCache();
00149     u->InvalidateNewGRFCache();
00150   }
00151 
00152   for (Train *u = this; u != NULL; u = u->Next()) {
00153     /* Update user defined data (must be done before other properties) */
00154     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00155     this->InvalidateNewGRFCache();
00156     u->InvalidateNewGRFCache();
00157   }
00158 
00159   for (Train *u = this; u != NULL; u = u->Next()) {
00160     const Engine *e_u = u->GetEngine();
00161     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00162 
00163     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00164 
00165     /* Cache wagon override sprite group. NULL is returned if there is none */
00166     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00167 
00168     /* Reset colour map */
00169     u->colourmap = PAL_NONE;
00170 
00171     /* Update powered-wagon-status and visual effect */
00172     u->UpdateVisualEffect(true);
00173 
00174     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00175         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00176       /* wagon is powered */
00177       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00178     } else {
00179       ClrBit(u->flags, VRF_POWEREDWAGON);
00180     }
00181 
00182     if (!u->IsArticulatedPart()) {
00183       /* Do not count powered wagons for the compatible railtypes, as wagons always
00184          have railtype normal */
00185       if (rvi_u->power > 0) {
00186         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00187       }
00188 
00189       /* Some electric engines can be allowed to run on normal rail. It happens to all
00190        * existing electric engines when elrails are disabled and then re-enabled */
00191       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00192         u->railtype = RAILTYPE_RAIL;
00193         u->compatible_railtypes |= RAILTYPES_RAIL;
00194       }
00195 
00196       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00197       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00198         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00199         if (speed != 0) max_speed = min(speed, max_speed);
00200       }
00201     }
00202 
00203     uint16 new_cap = e_u->DetermineCapacity(u);
00204     u->refit_cap = min(new_cap, u->refit_cap);
00205     u->cargo_cap = new_cap;
00206     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00207 
00208     /* check the vehicle length (callback) */
00209     uint16 veh_len = CALLBACK_FAILED;
00210     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00211       /* Use callback 36 */
00212       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00213 
00214       if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00215         ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00216       }
00217     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00218       /* Use callback 11 */
00219       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00220     }
00221     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00222     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00223 
00224     /* verify length hasn't changed */
00225     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00226 
00227     /* update vehicle length? */
00228     if (!same_length) u->gcache.cached_veh_length = veh_len;
00229 
00230     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00231     this->InvalidateNewGRFCache();
00232     u->InvalidateNewGRFCache();
00233   }
00234 
00235   /* store consist weight/max speed in cache */
00236   this->vcache.cached_max_speed = max_speed;
00237   this->tcache.cached_tilt = train_can_tilt;
00238   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00239 
00240   /* 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) */
00241   this->CargoChanged();
00242 
00243   if (this->IsFrontEngine()) {
00244     this->UpdateAcceleration();
00245     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00246     InvalidateWindowData(WC_VEHICLE_REFIT, this->index, VIWD_CONSIST_CHANGED);
00247     InvalidateWindowData(WC_VEHICLE_ORDERS, this->index, VIWD_CONSIST_CHANGED);
00248   }
00249 }
00250 
00261 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00262 {
00263   const Station *st = Station::Get(station_id);
00264   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00265   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00266 
00267   /* Default to the middle of the station for stations stops that are not in
00268    * the order list like intermediate stations when non-stop is disabled */
00269   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00270   if (v->gcache.cached_total_length >= *station_length) {
00271     /* The train is longer than the station, make it stop at the far end of the platform */
00272     osl = OSL_PLATFORM_FAR_END;
00273   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00274     osl = v->current_order.GetStopLocation();
00275   }
00276 
00277   /* The stop location of the FRONT! of the train */
00278   int stop;
00279   switch (osl) {
00280     default: NOT_REACHED();
00281 
00282     case OSL_PLATFORM_NEAR_END:
00283       stop = v->gcache.cached_total_length;
00284       break;
00285 
00286     case OSL_PLATFORM_MIDDLE:
00287       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00288       break;
00289 
00290     case OSL_PLATFORM_FAR_END:
00291       stop = *station_length;
00292       break;
00293   }
00294 
00295   /* Subtract half the front vehicle length of the train so we get the real
00296    * stop location of the train. */
00297   return stop - (v->gcache.cached_veh_length + 1) / 2;
00298 }
00299 
00300 
00305 int Train::GetCurveSpeedLimit() const
00306 {
00307   assert(this->First() == this);
00308 
00309   static const int absolute_max_speed = UINT16_MAX;
00310   int max_speed = absolute_max_speed;
00311 
00312   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00313 
00314   int curvecount[2] = {0, 0};
00315 
00316   /* first find the curve speed limit */
00317   int numcurve = 0;
00318   int sum = 0;
00319   int pos = 0;
00320   int lastpos = -1;
00321   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00322     Direction this_dir = u->direction;
00323     Direction next_dir = u->Next()->direction;
00324 
00325     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00326     if (dirdiff == DIRDIFF_SAME) continue;
00327 
00328     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00329     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00330     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00331       if (lastpos != -1) {
00332         numcurve++;
00333         sum += pos - lastpos;
00334         if (pos - lastpos == 1 && max_speed > 88) {
00335           max_speed = 88;
00336         }
00337       }
00338       lastpos = pos;
00339     }
00340 
00341     /* if we have a 90 degree turn, fix the speed limit to 60 */
00342     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00343       max_speed = 61;
00344     }
00345   }
00346 
00347   if (numcurve > 0 && max_speed > 88) {
00348     if (curvecount[0] == 1 && curvecount[1] == 1) {
00349       max_speed = absolute_max_speed;
00350     } else {
00351       sum /= numcurve;
00352       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00353     }
00354   }
00355 
00356   if (max_speed != absolute_max_speed) {
00357     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00358     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00359     max_speed += (max_speed / 2) * rti->curve_speed;
00360 
00361     if (this->tcache.cached_tilt) {
00362       /* Apply max_speed bonus of 20% for a tilting train */
00363       max_speed += max_speed / 5;
00364     }
00365   }
00366 
00367   return max_speed;
00368 }
00369 
00374 int Train::GetCurrentMaxSpeed() const
00375 {
00376   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return min(this->gcache.cached_max_track_speed, this->current_order.max_speed);
00377 
00378   int max_speed = this->tcache.cached_max_curve_speed;
00379   if (IsRailStationTile(this->tile)) {
00380     StationID sid = GetStationIndex(this->tile);
00381     if (this->current_order.ShouldStopAtStation(this, sid)) {
00382       int station_ahead;
00383       int station_length;
00384       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00385 
00386       /* The distance to go is whatever is still ahead of the train minus the
00387        * distance from the train's stop location to the end of the platform */
00388       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00389 
00390       if (distance_to_go > 0) {
00391         int st_max_speed = 120;
00392 
00393         int delta_v = this->cur_speed / (distance_to_go + 1);
00394         if (max_speed > (this->cur_speed - delta_v)) {
00395           st_max_speed = this->cur_speed - (delta_v / 10);
00396         }
00397 
00398         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00399         max_speed = min(max_speed, st_max_speed);
00400       }
00401     }
00402   }
00403 
00404   for (const Train *u = this; u != NULL; u = u->Next()) {
00405     if (u->track == TRACK_BIT_DEPOT) {
00406       max_speed = min(max_speed, 61);
00407       break;
00408     }
00409 
00410     /* Vehicle is on the middle part of a bridge. */
00411     if (u->track == TRACK_BIT_WORMHOLE && !(u->vehstatus & VS_HIDDEN)) {
00412       max_speed = min(max_speed, GetBridgeSpec(GetBridgeType(u->tile))->speed);
00413     }
00414   }
00415 
00416   max_speed = min(max_speed, this->current_order.max_speed);
00417   return min(max_speed, this->gcache.cached_max_track_speed);
00418 }
00419 
00421 void Train::UpdateAcceleration()
00422 {
00423   assert(this->IsFrontEngine());
00424 
00425   uint power = this->gcache.cached_power;
00426   uint weight = this->gcache.cached_weight;
00427   assert(weight != 0);
00428   this->acceleration = Clamp(power / weight * 4, 1, 255);
00429 }
00430 
00436 int Train::GetDisplayImageWidth(Point *offset) const
00437 {
00438   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00439   int vehicle_pitch = 0;
00440 
00441   const Engine *e = this->GetEngine();
00442   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00443     reference_width = e->GetGRF()->traininfo_vehicle_width;
00444     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00445   }
00446 
00447   if (offset != NULL) {
00448     offset->x = reference_width / 2;
00449     offset->y = vehicle_pitch;
00450   }
00451   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00452 }
00453 
00454 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00455 {
00456   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00457 }
00458 
00465 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00466 {
00467   uint8 spritenum = this->spritenum;
00468   SpriteID sprite;
00469 
00470   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00471 
00472   if (is_custom_sprite(spritenum)) {
00473     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00474     if (sprite != 0) return sprite;
00475 
00476     spritenum = this->GetEngine()->original_image_index;
00477   }
00478 
00479   sprite = GetDefaultTrainSprite(spritenum, direction);
00480 
00481   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00482 
00483   return sprite;
00484 }
00485 
00486 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00487 {
00488   const Engine *e = Engine::Get(engine);
00489   Direction dir = rear_head ? DIR_E : DIR_W;
00490   uint8 spritenum = e->u.rail.image_index;
00491 
00492   if (is_custom_sprite(spritenum)) {
00493     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00494     if (sprite != 0) {
00495       if (e->GetGRF() != NULL) {
00496         y += e->GetGRF()->traininfo_vehicle_pitch;
00497       }
00498       return sprite;
00499     }
00500 
00501     spritenum = Engine::Get(engine)->original_image_index;
00502   }
00503 
00504   if (rear_head) spritenum++;
00505 
00506   return GetDefaultTrainSprite(spritenum, DIR_W);
00507 }
00508 
00509 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00510 {
00511   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00512     int yf = y;
00513     int yr = y;
00514 
00515     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00516     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00517     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00518     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00519 
00520     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);
00521 
00522     DrawSprite(spritef, pal, preferred_x - 14, yf);
00523     DrawSprite(spriter, pal, preferred_x + 15, yr);
00524   } else {
00525     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00526     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00527     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));
00528     DrawSprite(sprite, pal, preferred_x, y);
00529   }
00530 }
00531 
00541 void GetTrainSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type)
00542 {
00543   int y = 0;
00544 
00545   SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00546   const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00547 
00548   width  = UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI);
00549   height = UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI);
00550   xoffs  = UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI);
00551   yoffs  = UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI);
00552 
00553   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00554     sprite = GetRailIcon(engine, true, y, image_type);
00555     real_sprite = GetSprite(sprite, ST_NORMAL);
00556 
00557     /* Calculate values relative to an imaginary center between the two sprites. */
00558     width = TRAININFO_DEFAULT_VEHICLE_WIDTH + UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) + UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI) - xoffs;
00559     height = max<uint>(height, UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI));
00560     xoffs  = xoffs - TRAININFO_DEFAULT_VEHICLE_WIDTH / 2;
00561     yoffs  = min(yoffs, UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI));
00562   }
00563 }
00564 
00573 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00574 {
00575   const RailVehicleInfo *rvi = &e->u.rail;
00576 
00577   /* Check that the wagon can drive on the track in question */
00578   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00579 
00580   if (flags & DC_EXEC) {
00581     Train *v = new Train();
00582     *ret = v;
00583     v->spritenum = rvi->image_index;
00584 
00585     v->engine_type = e->index;
00586     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00587 
00588     DiagDirection dir = GetRailDepotDirection(tile);
00589 
00590     v->direction = DiagDirToDir(dir);
00591     v->tile = tile;
00592 
00593     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00594     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00595 
00596     v->x_pos = x;
00597     v->y_pos = y;
00598     v->z_pos = GetSlopePixelZ(x, y);
00599     v->owner = _current_company;
00600     v->track = TRACK_BIT_DEPOT;
00601     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00602 
00603     v->SetWagon();
00604 
00605     v->SetFreeWagon();
00606     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00607 
00608     v->cargo_type = e->GetDefaultCargoType();
00609     v->cargo_cap = rvi->capacity;
00610     v->refit_cap = 0;
00611 
00612     v->railtype = rvi->railtype;
00613 
00614     v->build_year = _cur_year;
00615     v->cur_image = SPR_IMG_QUERY;
00616     v->random_bits = VehicleRandomBits();
00617 
00618     v->group_id = DEFAULT_GROUP;
00619 
00620     AddArticulatedParts(v);
00621 
00622     _new_vehicle_id = v->index;
00623 
00624     VehicleUpdatePosition(v);
00625     v->First()->ConsistChanged(false);
00626     UpdateTrainGroupID(v->First());
00627 
00628     CheckConsistencyOfArticulatedVehicle(v);
00629 
00630     /* Try to connect the vehicle to one of free chains of wagons. */
00631     Train *w;
00632     FOR_ALL_TRAINS(w) {
00633       if (w->tile == tile &&              
00634           w->IsFreeWagon() &&             
00635           w->engine_type == e->index &&   
00636           w->First() != v &&              
00637           !(w->vehstatus & VS_CRASHED)) { 
00638         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00639         break;
00640       }
00641     }
00642   }
00643 
00644   return CommandCost();
00645 }
00646 
00648 static void NormalizeTrainVehInDepot(const Train *u)
00649 {
00650   const Train *v;
00651   FOR_ALL_TRAINS(v) {
00652     if (v->IsFreeWagon() && v->tile == u->tile &&
00653         v->track == TRACK_BIT_DEPOT) {
00654       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00655           CMD_MOVE_RAIL_VEHICLE).Failed())
00656         break;
00657     }
00658   }
00659 }
00660 
00661 static void AddRearEngineToMultiheadedTrain(Train *v)
00662 {
00663   Train *u = new Train();
00664   v->value >>= 1;
00665   u->value = v->value;
00666   u->direction = v->direction;
00667   u->owner = v->owner;
00668   u->tile = v->tile;
00669   u->x_pos = v->x_pos;
00670   u->y_pos = v->y_pos;
00671   u->z_pos = v->z_pos;
00672   u->track = TRACK_BIT_DEPOT;
00673   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00674   u->spritenum = v->spritenum + 1;
00675   u->cargo_type = v->cargo_type;
00676   u->cargo_subtype = v->cargo_subtype;
00677   u->cargo_cap = v->cargo_cap;
00678   u->refit_cap = v->refit_cap;
00679   u->railtype = v->railtype;
00680   u->engine_type = v->engine_type;
00681   u->build_year = v->build_year;
00682   u->cur_image = SPR_IMG_QUERY;
00683   u->random_bits = VehicleRandomBits();
00684   v->SetMultiheaded();
00685   u->SetMultiheaded();
00686   v->SetNext(u);
00687   VehicleUpdatePosition(u);
00688 
00689   /* Now we need to link the front and rear engines together */
00690   v->other_multiheaded_part = u;
00691   u->other_multiheaded_part = v;
00692 }
00693 
00703 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00704 {
00705   const RailVehicleInfo *rvi = &e->u.rail;
00706 
00707   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00708 
00709   /* Check if depot and new engine uses the same kind of tracks *
00710    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00711   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00712 
00713   if (flags & DC_EXEC) {
00714     DiagDirection dir = GetRailDepotDirection(tile);
00715     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00716     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00717 
00718     Train *v = new Train();
00719     *ret = v;
00720     v->direction = DiagDirToDir(dir);
00721     v->tile = tile;
00722     v->owner = _current_company;
00723     v->x_pos = x;
00724     v->y_pos = y;
00725     v->z_pos = GetSlopePixelZ(x, y);
00726     v->track = TRACK_BIT_DEPOT;
00727     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00728     v->spritenum = rvi->image_index;
00729     v->cargo_type = e->GetDefaultCargoType();
00730     v->cargo_cap = rvi->capacity;
00731     v->refit_cap = 0;
00732     v->last_station_visited = INVALID_STATION;
00733     v->last_loading_station = INVALID_STATION;
00734 
00735     v->engine_type = e->index;
00736     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00737 
00738     v->reliability = e->reliability;
00739     v->reliability_spd_dec = e->reliability_spd_dec;
00740     v->max_age = e->GetLifeLengthInDays();
00741 
00742     v->railtype = rvi->railtype;
00743     _new_vehicle_id = v->index;
00744 
00745     v->service_interval = Company::Get(_current_company)->settings.vehicle.servint_trains;
00746     v->date_of_last_service = _date;
00747     v->build_year = _cur_year;
00748     v->cur_image = SPR_IMG_QUERY;
00749     v->random_bits = VehicleRandomBits();
00750 
00751     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00752 
00753     v->group_id = DEFAULT_GROUP;
00754 
00755     v->SetFrontEngine();
00756     v->SetEngine();
00757 
00758     VehicleUpdatePosition(v);
00759 
00760     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00761       AddRearEngineToMultiheadedTrain(v);
00762     } else {
00763       AddArticulatedParts(v);
00764     }
00765 
00766     v->ConsistChanged(false);
00767     UpdateTrainGroupID(v);
00768 
00769     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00770       NormalizeTrainVehInDepot(v);
00771     }
00772 
00773     CheckConsistencyOfArticulatedVehicle(v);
00774   }
00775 
00776   return CommandCost();
00777 }
00778 
00779 static Train *FindGoodVehiclePos(const Train *src)
00780 {
00781   EngineID eng = src->engine_type;
00782   TileIndex tile = src->tile;
00783 
00784   Train *dst;
00785   FOR_ALL_TRAINS(dst) {
00786     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00787       /* check so all vehicles in the line have the same engine. */
00788       Train *t = dst;
00789       while (t->engine_type == eng) {
00790         t = t->Next();
00791         if (t == NULL) return dst;
00792       }
00793     }
00794   }
00795 
00796   return NULL;
00797 }
00798 
00800 typedef SmallVector<Train *, 16> TrainList;
00801 
00807 static void MakeTrainBackup(TrainList &list, Train *t)
00808 {
00809   for (; t != NULL; t = t->Next()) *list.Append() = t;
00810 }
00811 
00816 static void RestoreTrainBackup(TrainList &list)
00817 {
00818   /* No train, nothing to do. */
00819   if (list.Length() == 0) return;
00820 
00821   Train *prev = NULL;
00822   /* Iterate over the list and rebuild it. */
00823   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00824     Train *t = *iter;
00825     if (prev != NULL) {
00826       prev->SetNext(t);
00827     } else if (t->Previous() != NULL) {
00828       /* Make sure the head of the train is always the first in the chain. */
00829       t->Previous()->SetNext(NULL);
00830     }
00831     prev = t;
00832   }
00833 }
00834 
00840 static void RemoveFromConsist(Train *part, bool chain = false)
00841 {
00842   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00843 
00844   /* Unlink at the front, but make it point to the next
00845    * vehicle after the to be remove part. */
00846   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00847 
00848   /* Unlink at the back */
00849   tail->SetNext(NULL);
00850 }
00851 
00857 static void InsertInConsist(Train *dst, Train *chain)
00858 {
00859   /* We do not want to add something in the middle of an articulated part. */
00860   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00861 
00862   chain->Last()->SetNext(dst->Next());
00863   dst->SetNext(chain);
00864 }
00865 
00871 static void NormaliseDualHeads(Train *t)
00872 {
00873   for (; t != NULL; t = t->GetNextVehicle()) {
00874     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00875 
00876     /* Make sure that there are no free cars before next engine */
00877     Train *u;
00878     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00879 
00880     if (u == t->other_multiheaded_part) continue;
00881 
00882     /* Remove the part from the 'wrong' train */
00883     RemoveFromConsist(t->other_multiheaded_part);
00884     /* And add it to the 'right' train */
00885     InsertInConsist(u, t->other_multiheaded_part);
00886   }
00887 }
00888 
00893 static void NormaliseSubtypes(Train *chain)
00894 {
00895   /* Nothing to do */
00896   if (chain == NULL) return;
00897 
00898   /* We must be the first in the chain. */
00899   assert(chain->Previous() == NULL);
00900 
00901   /* Set the appropriate bits for the first in the chain. */
00902   if (chain->IsWagon()) {
00903     chain->SetFreeWagon();
00904   } else {
00905     assert(chain->IsEngine());
00906     chain->SetFrontEngine();
00907   }
00908 
00909   /* Now clear the bits for the rest of the chain */
00910   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00911     t->ClearFreeWagon();
00912     t->ClearFrontEngine();
00913   }
00914 }
00915 
00925 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00926 {
00927   /* Just add 'new' engines and subtract the original ones.
00928    * If that's less than or equal to 0 we can be sure we did
00929    * not add any engines (read: trains) along the way. */
00930   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00931       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00932       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00933       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00934     return CommandCost();
00935   }
00936 
00937   /* Get a free unit number and check whether it's within the bounds.
00938    * There will always be a maximum of one new train. */
00939   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00940 
00941   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00942 }
00943 
00949 static CommandCost CheckTrainAttachment(Train *t)
00950 {
00951   /* No multi-part train, no need to check. */
00952   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00953 
00954   /* The maximum length for a train. For each part we decrease this by one
00955    * and if the result is negative the train is simply too long. */
00956   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00957 
00958   Train *head = t;
00959   Train *prev = t;
00960 
00961   /* Break the prev -> t link so it always holds within the loop. */
00962   t = t->Next();
00963   prev->SetNext(NULL);
00964 
00965   /* Make sure the cache is cleared. */
00966   head->InvalidateNewGRFCache();
00967 
00968   while (t != NULL) {
00969     allowed_len -= t->gcache.cached_veh_length;
00970 
00971     Train *next = t->Next();
00972 
00973     /* Unlink the to-be-added piece; it is already unlinked from the previous
00974      * part due to the fact that the prev -> t link is broken. */
00975     t->SetNext(NULL);
00976 
00977     /* Don't check callback for articulated or rear dual headed parts */
00978     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00979       /* Back up and clear the first_engine data to avoid using wagon override group */
00980       EngineID first_engine = t->gcache.first_engine;
00981       t->gcache.first_engine = INVALID_ENGINE;
00982 
00983       /* We don't want the cache to interfere. head's cache is cleared before
00984        * the loop and after each callback does not need to be cleared here. */
00985       t->InvalidateNewGRFCache();
00986 
00987       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00988 
00989       /* Restore original first_engine data */
00990       t->gcache.first_engine = first_engine;
00991 
00992       /* We do not want to remember any cached variables from the test run */
00993       t->InvalidateNewGRFCache();
00994       head->InvalidateNewGRFCache();
00995 
00996       if (callback != CALLBACK_FAILED) {
00997         /* A failing callback means everything is okay */
00998         StringID error = STR_NULL;
00999 
01000         if (head->GetGRF()->grf_version < 8) {
01001           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01002           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01003           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
01004         } else {
01005           if (callback < 0x400) {
01006             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01007           } else {
01008             switch (callback) {
01009               case 0x400: // allow if railtypes match (always the case for OpenTTD)
01010               case 0x401: // allow
01011                 break;
01012 
01013               default:    // unknown reason -> disallow
01014               case 0x402: // disallow attaching
01015                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01016                 break;
01017             }
01018           }
01019         }
01020 
01021         if (error != STR_NULL) return_cmd_error(error);
01022       }
01023     }
01024 
01025     /* And link it to the new part. */
01026     prev->SetNext(t);
01027     prev = t;
01028     t = next;
01029   }
01030 
01031   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01032   return CommandCost();
01033 }
01034 
01045 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01046 {
01047   /* Check whether we may actually construct the trains. */
01048   CommandCost ret = CheckTrainAttachment(src);
01049   if (ret.Failed()) return ret;
01050   ret = CheckTrainAttachment(dst);
01051   if (ret.Failed()) return ret;
01052 
01053   /* Check whether we need to build a new train. */
01054   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01055 }
01056 
01065 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01066 {
01067   /* First determine the front of the two resulting trains */
01068   if (*src_head == *dst_head) {
01069     /* If we aren't moving part(s) to a new train, we are just moving the
01070      * front back and there is not destination head. */
01071     *dst_head = NULL;
01072   } else if (*dst_head == NULL) {
01073     /* If we are moving to a new train the head of the move train would become
01074      * the head of the new vehicle. */
01075     *dst_head = src;
01076   }
01077 
01078   if (src == *src_head) {
01079     /* If we are moving the front of a train then we are, in effect, creating
01080      * a new head for the train. Point to that. Unless we are moving the whole
01081      * train in which case there is not 'source' train anymore.
01082      * In case we are a multiheaded part we want the complete thing to come
01083      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01084      * that is followed by a rear multihead we do not want to include that. */
01085     *src_head = move_chain ? NULL :
01086         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01087   }
01088 
01089   /* Now it's just simply removing the part that we are going to move from the
01090    * source train and *if* the destination is a not a new train add the chain
01091    * at the destination location. */
01092   RemoveFromConsist(src, move_chain);
01093   if (*dst_head != src) InsertInConsist(dst, src);
01094 
01095   /* Now normalise the dual heads, that is move the dual heads around in such
01096    * a way that the head and rear of a dual head are in the same train */
01097   NormaliseDualHeads(*src_head);
01098   NormaliseDualHeads(*dst_head);
01099 }
01100 
01106 static void NormaliseTrainHead(Train *head)
01107 {
01108   /* Not much to do! */
01109   if (head == NULL) return;
01110 
01111   /* Tell the 'world' the train changed. */
01112   head->ConsistChanged(false);
01113   UpdateTrainGroupID(head);
01114 
01115   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01116   if (!head->IsFrontEngine()) return;
01117 
01118   /* Update the refit button and window */
01119   InvalidateWindowData(WC_VEHICLE_REFIT, head->index, VIWD_CONSIST_CHANGED);
01120   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01121 
01122   /* If we don't have a unit number yet, set one. */
01123   if (head->unitnumber != 0) return;
01124   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01125 }
01126 
01139 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01140 {
01141   VehicleID s = GB(p1, 0, 20);
01142   VehicleID d = GB(p2, 0, 20);
01143   bool move_chain = HasBit(p1, 20);
01144 
01145   Train *src = Train::GetIfValid(s);
01146   if (src == NULL) return CMD_ERROR;
01147 
01148   CommandCost ret = CheckOwnership(src->owner);
01149   if (ret.Failed()) return ret;
01150 
01151   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01152   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01153 
01154   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01155   Train *dst;
01156   if (d == INVALID_VEHICLE) {
01157     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01158   } else {
01159     dst = Train::GetIfValid(d);
01160     if (dst == NULL) return CMD_ERROR;
01161 
01162     CommandCost ret = CheckOwnership(dst->owner);
01163     if (ret.Failed()) return ret;
01164 
01165     /* Do not allow appending to crashed vehicles, too */
01166     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01167   }
01168 
01169   /* if an articulated part is being handled, deal with its parent vehicle */
01170   src = src->GetFirstEnginePart();
01171   if (dst != NULL) {
01172     dst = dst->GetFirstEnginePart();
01173   }
01174 
01175   /* don't move the same vehicle.. */
01176   if (src == dst) return CommandCost();
01177 
01178   /* locate the head of the two chains */
01179   Train *src_head = src->First();
01180   Train *dst_head;
01181   if (dst != NULL) {
01182     dst_head = dst->First();
01183     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01184     /* Now deal with articulated part of destination wagon */
01185     dst = dst->GetLastEnginePart();
01186   } else {
01187     dst_head = NULL;
01188   }
01189 
01190   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01191 
01192   /* When moving all wagons, we can't have the same src_head and dst_head */
01193   if (move_chain && src_head == dst_head) return CommandCost();
01194 
01195   /* When moving a multiheaded part to be place after itself, bail out. */
01196   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01197 
01198   /* Check if all vehicles in the source train are stopped inside a depot. */
01199   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01200 
01201   /* Check if all vehicles in the destination train are stopped inside a depot. */
01202   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01203 
01204   /* First make a backup of the order of the trains. That way we can do
01205    * whatever we want with the order and later on easily revert. */
01206   TrainList original_src;
01207   TrainList original_dst;
01208 
01209   MakeTrainBackup(original_src, src_head);
01210   MakeTrainBackup(original_dst, dst_head);
01211 
01212   /* Also make backup of the original heads as ArrangeTrains can change them.
01213    * For the destination head we do not care if it is the same as the source
01214    * head because in that case it's just a copy. */
01215   Train *original_src_head = src_head;
01216   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01217 
01218   /* We want this information from before the rearrangement, but execute this after the validation. */
01219   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01220   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01221 
01222   /* (Re)arrange the trains in the wanted arrangement. */
01223   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01224 
01225   if ((flags & DC_AUTOREPLACE) == 0) {
01226     /* If the autoreplace flag is set we do not need to test for the validity
01227      * because we are going to revert the train to its original state. As we
01228      * assume the original state was correct autoreplace can skip this. */
01229     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01230     if (ret.Failed()) {
01231       /* Restore the train we had. */
01232       RestoreTrainBackup(original_src);
01233       RestoreTrainBackup(original_dst);
01234       return ret;
01235     }
01236   }
01237 
01238   /* do it? */
01239   if (flags & DC_EXEC) {
01240     /* Remove old heads from the statistics */
01241     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01242     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01243 
01244     /* First normalise the sub types of the chains. */
01245     NormaliseSubtypes(src_head);
01246     NormaliseSubtypes(dst_head);
01247 
01248     /* There are 14 different cases:
01249      *  1) front engine gets moved to a new train, it stays a front engine.
01250      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01251      *     b) the 'next' part is an engine that becomes a front engine.
01252      *     c) there is no 'next' part, nothing else happens
01253      *  2) front engine gets moved to another train, it is not a front engine anymore
01254      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01255      *     b) the 'next' part is an engine that becomes a front engine.
01256      *     c) there is no 'next' part, nothing else happens
01257      *  3) front engine gets moved to later in the current train, it is not a front engine anymore.
01258      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01259      *     b) the 'next' part is an engine that becomes a front engine.
01260      *  4) free wagon gets moved
01261      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01262      *     b) the 'next' part is an engine that becomes a front engine.
01263      *     c) there is no 'next' part, nothing else happens
01264      *  5) non front engine gets moved and becomes a new train, nothing else happens
01265      *  6) non front engine gets moved within a train / to another train, nothing hapens
01266      *  7) wagon gets moved, nothing happens
01267      */
01268     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01269       /* Cases #2 and #3: the front engine gets trashed. */
01270       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01271       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01272       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01273       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01274       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01275       SetWindowDirty(WC_COMPANY, _current_company);
01276 
01277       /* Delete orders, group stuff and the unit number as we're not the
01278        * front of any vehicle anymore. */
01279       DeleteVehicleOrders(src);
01280       RemoveVehicleFromGroup(src);
01281       src->unitnumber = 0;
01282     }
01283 
01284     /* We weren't a front engine but are becoming one. So
01285      * we should be put in the default group. */
01286     if (original_src_head != src && dst_head == src) {
01287       SetTrainGroupID(src, DEFAULT_GROUP);
01288       SetWindowDirty(WC_COMPANY, _current_company);
01289     }
01290 
01291     /* Add new heads to statistics */
01292     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01293     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01294 
01295     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01296     NormaliseTrainHead(src_head);
01297     NormaliseTrainHead(dst_head);
01298 
01299     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01300       CheckCargoCapacity(src_head);
01301       CheckCargoCapacity(dst_head);
01302     }
01303 
01304     /* We are undoubtedly changing something in the depot and train list. */
01305     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01306     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01307   } else {
01308     /* We don't want to execute what we're just tried. */
01309     RestoreTrainBackup(original_src);
01310     RestoreTrainBackup(original_dst);
01311   }
01312 
01313   return CommandCost();
01314 }
01315 
01327 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01328 {
01329   /* Check if we deleted a vehicle window */
01330   Window *w = NULL;
01331 
01332   /* Sell a chain of vehicles or not? */
01333   bool sell_chain = HasBit(data, 0);
01334 
01335   Train *v = Train::From(t)->GetFirstEnginePart();
01336   Train *first = v->First();
01337 
01338   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01339 
01340   /* First make a backup of the order of the train. That way we can do
01341    * whatever we want with the order and later on easily revert. */
01342   TrainList original;
01343   MakeTrainBackup(original, first);
01344 
01345   /* We need to keep track of the new head and the head of what we're going to sell. */
01346   Train *new_head = first;
01347   Train *sell_head = NULL;
01348 
01349   /* Split the train in the wanted way. */
01350   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01351 
01352   /* We don't need to validate the second train; it's going to be sold. */
01353   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01354   if (ret.Failed()) {
01355     /* Restore the train we had. */
01356     RestoreTrainBackup(original);
01357     return ret;
01358   }
01359 
01360   CommandCost cost(EXPENSES_NEW_VEHICLES);
01361   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01362 
01363   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01364     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01365   }
01366 
01367   /* do it? */
01368   if (flags & DC_EXEC) {
01369     /* First normalise the sub types of the chain. */
01370     NormaliseSubtypes(new_head);
01371 
01372     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01373       /* We are selling the front engine. In this case we want to
01374        * 'give' the order, unit number and such to the new head. */
01375       new_head->orders.list = first->orders.list;
01376       new_head->AddToShared(first);
01377       DeleteVehicleOrders(first);
01378 
01379       /* Copy other important data from the front engine */
01380       new_head->CopyVehicleConfigAndStatistics(first);
01381       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01382 
01383       /* If we deleted a window then open a new one for the 'new' train */
01384       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01385     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01386       OrderBackup::Backup(v, user);
01387     }
01388 
01389     /* We need to update the information about the train. */
01390     NormaliseTrainHead(new_head);
01391 
01392     /* We are undoubtedly changing something in the depot and train list. */
01393     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01394     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01395 
01396     /* Actually delete the sold 'goods' */
01397     delete sell_head;
01398   } else {
01399     /* We don't want to execute what we're just tried. */
01400     RestoreTrainBackup(original);
01401   }
01402 
01403   return cost;
01404 }
01405 
01406 void Train::UpdateDeltaXY(Direction direction)
01407 {
01408   /* Set common defaults. */
01409   this->x_offs    = -1;
01410   this->y_offs    = -1;
01411   this->x_extent  =  3;
01412   this->y_extent  =  3;
01413   this->z_extent  =  6;
01414   this->x_bb_offs =  0;
01415   this->y_bb_offs =  0;
01416 
01417   if (!IsDiagonalDirection(direction)) {
01418     static const int _sign_table[] =
01419     {
01420       // x, y
01421       -1, -1, // DIR_N
01422       -1,  1, // DIR_E
01423        1,  1, // DIR_S
01424        1, -1, // DIR_W
01425     };
01426 
01427     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01428 
01429     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01430     this->x_offs -= half_shorten * _sign_table[direction];
01431     this->y_offs -= half_shorten * _sign_table[direction + 1];
01432     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01433     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01434   } else {
01435     switch (direction) {
01436         /* Shorten southern corner of the bounding box according the vehicle length
01437          * and center the bounding box on the vehicle. */
01438       case DIR_NE:
01439         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01440         this->x_extent  = this->gcache.cached_veh_length - 1;
01441         this->x_bb_offs = -1;
01442         break;
01443 
01444       case DIR_NW:
01445         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01446         this->y_extent  = this->gcache.cached_veh_length - 1;
01447         this->y_bb_offs = -1;
01448         break;
01449 
01450         /* Move northern corner of the bounding box down according to vehicle length
01451          * and center the bounding box on the vehicle. */
01452       case DIR_SW:
01453         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01454         this->x_extent  = VEHICLE_LENGTH - 1;
01455         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01456         break;
01457 
01458       case DIR_SE:
01459         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01460         this->y_extent  = VEHICLE_LENGTH - 1;
01461         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01462         break;
01463 
01464       default:
01465         NOT_REACHED();
01466     }
01467   }
01468 }
01469 
01474 static void MarkTrainAsStuck(Train *v)
01475 {
01476   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01477     /* It is the first time the problem occurred, set the "train stuck" flag. */
01478     SetBit(v->flags, VRF_TRAIN_STUCK);
01479 
01480     v->wait_counter = 0;
01481 
01482     /* Stop train */
01483     v->cur_speed = 0;
01484     v->subspeed = 0;
01485     v->SetLastSpeed();
01486 
01487     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01488   }
01489 }
01490 
01498 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01499 {
01500   uint16 flag1 = *swap_flag1;
01501   uint16 flag2 = *swap_flag2;
01502 
01503   /* Clear the flags */
01504   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01505   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01506   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01507   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01508 
01509   /* Reverse the rail-flags (if needed) */
01510   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01511     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01512   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01513     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01514   }
01515   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01516     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01517   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01518     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01519   }
01520 }
01521 
01526 static void UpdateStatusAfterSwap(Train *v)
01527 {
01528   /* Reverse the direction. */
01529   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01530 
01531   /* Call the proper EnterTile function unless we are in a wormhole. */
01532   if (v->track != TRACK_BIT_WORMHOLE) {
01533     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01534   } else {
01535     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01536      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01537      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01538      * when we shouldn't have. Check if this is the case. */
01539     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01540     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01541       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01542       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01543         /* We have just left the wormhole, possibly set the
01544          * "goingdown" bit. UpdateInclination() can be used
01545          * because we are at the border of the tile. */
01546         VehicleUpdatePosition(v);
01547         v->UpdateInclination(true, true);
01548         return;
01549       }
01550     }
01551   }
01552 
01553   VehicleUpdatePosition(v);
01554   v->UpdateViewport(true, true);
01555 }
01556 
01563 void ReverseTrainSwapVeh(Train *v, int l, int r)
01564 {
01565   Train *a, *b;
01566 
01567   /* locate vehicles to swap */
01568   for (a = v; l != 0; l--) a = a->Next();
01569   for (b = v; r != 0; r--) b = b->Next();
01570 
01571   if (a != b) {
01572     /* swap the hidden bits */
01573     {
01574       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01575       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01576       a->vehstatus = tmp;
01577     }
01578 
01579     Swap(a->track, b->track);
01580     Swap(a->direction, b->direction);
01581     Swap(a->x_pos, b->x_pos);
01582     Swap(a->y_pos, b->y_pos);
01583     Swap(a->tile,  b->tile);
01584     Swap(a->z_pos, b->z_pos);
01585 
01586     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01587 
01588     UpdateStatusAfterSwap(a);
01589     UpdateStatusAfterSwap(b);
01590   } else {
01591     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01592      * This is a little bit redundant way, a->gv_flags will
01593      * be (re)set twice, but it reduces code duplication */
01594     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01595     UpdateStatusAfterSwap(a);
01596   }
01597 }
01598 
01599 
01605 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01606 {
01607   return (v->type == VEH_TRAIN) ? v : NULL;
01608 }
01609 
01610 
01617 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01618 {
01619   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01620 
01621   Train *t = Train::From(v);
01622   if (!t->IsFrontEngine()) return NULL;
01623 
01624   TileIndex tile = *(TileIndex *)data;
01625 
01626   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01627 
01628   return t;
01629 }
01630 
01631 
01638 static bool TrainApproachingCrossing(TileIndex tile)
01639 {
01640   assert(IsLevelCrossingTile(tile));
01641 
01642   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01643   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01644 
01645   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01646 
01647   dir = ReverseDiagDir(dir);
01648   tile_from = tile + TileOffsByDiagDir(dir);
01649 
01650   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01651 }
01652 
01653 
01660 void UpdateLevelCrossing(TileIndex tile, bool sound)
01661 {
01662   assert(IsLevelCrossingTile(tile));
01663 
01664   /* train on crossing || train approaching crossing || reserved */
01665   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01666 
01667   if (new_state != IsCrossingBarred(tile)) {
01668     if (new_state && sound) {
01669       if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01670     }
01671     SetCrossingBarred(tile, new_state);
01672     MarkTileDirtyByTile(tile);
01673   }
01674 }
01675 
01676 
01682 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01683 {
01684   if (!IsCrossingBarred(tile)) {
01685     BarCrossing(tile);
01686     if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01687     MarkTileDirtyByTile(tile);
01688   }
01689 }
01690 
01691 
01697 static void AdvanceWagonsBeforeSwap(Train *v)
01698 {
01699   Train *base = v;
01700   Train *first = base; // first vehicle to move
01701   Train *last = v->Last(); // last vehicle to move
01702   uint length = CountVehiclesInChain(v);
01703 
01704   while (length > 2) {
01705     last = last->Previous();
01706     first = first->Next();
01707 
01708     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01709 
01710     /* do not update images now
01711      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01712     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01713 
01714     base = first; // == base->Next()
01715     length -= 2;
01716   }
01717 }
01718 
01719 
01725 static void AdvanceWagonsAfterSwap(Train *v)
01726 {
01727   /* first of all, fix the situation when the train was entering a depot */
01728   Train *dep = v; // last vehicle in front of just left depot
01729   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01730     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01731   }
01732 
01733   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01734 
01735   if (leave != NULL) {
01736     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01737     int d = TicksToLeaveDepot(dep);
01738 
01739     if (d <= 0) {
01740       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01741       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01742       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01743     }
01744   } else {
01745     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01746   }
01747 
01748   Train *base = v;
01749   Train *first = base; // first vehicle to move
01750   Train *last = v->Last(); // last vehicle to move
01751   uint length = CountVehiclesInChain(v);
01752 
01753   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01754    * they have already correct spacing, so we have to make sure they are moved how they should */
01755   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01756 
01757   while (length > 2) {
01758     /* we reached vehicle (originally) in front of a depot, stop now
01759      * (we would move wagons that are already moved with new wagon length). */
01760     if (base == dep) break;
01761 
01762     /* the last wagon was that one leaving a depot, so do not move it anymore */
01763     if (last == dep) nomove = true;
01764 
01765     last = last->Previous();
01766     first = first->Next();
01767 
01768     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01769 
01770     /* do not update images now */
01771     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01772 
01773     base = first; // == base->Next()
01774     length -= 2;
01775   }
01776 }
01777 
01782 void ReverseTrainDirection(Train *v)
01783 {
01784   if (IsRailDepotTile(v->tile)) {
01785     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01786   }
01787 
01788   /* Clear path reservation in front if train is not stuck. */
01789   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01790 
01791   /* Check if we were approaching a rail/road-crossing */
01792   TileIndex crossing = TrainApproachingCrossingTile(v);
01793 
01794   /* count number of vehicles */
01795   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01796 
01797   AdvanceWagonsBeforeSwap(v);
01798 
01799   /* swap start<>end, start+1<>end-1, ... */
01800   int l = 0;
01801   do {
01802     ReverseTrainSwapVeh(v, l++, r--);
01803   } while (l <= r);
01804 
01805   AdvanceWagonsAfterSwap(v);
01806 
01807   if (IsRailDepotTile(v->tile)) {
01808     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01809   }
01810 
01811   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01812 
01813   ClrBit(v->flags, VRF_REVERSING);
01814 
01815   /* recalculate cached data */
01816   v->ConsistChanged(true);
01817 
01818   /* update all images */
01819   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01820 
01821   /* update crossing we were approaching */
01822   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01823 
01824   /* maybe we are approaching crossing now, after reversal */
01825   crossing = TrainApproachingCrossingTile(v);
01826   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01827 
01828   /* If we are inside a depot after reversing, don't bother with path reserving. */
01829   if (v->track == TRACK_BIT_DEPOT) {
01830     /* Can't be stuck here as inside a depot is always a safe tile. */
01831     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01832     ClrBit(v->flags, VRF_TRAIN_STUCK);
01833     return;
01834   }
01835 
01836   /* TrainExitDir does not always produce the desired dir for depots and
01837    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01838   DiagDirection dir = TrainExitDir(v->direction, v->track);
01839   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01840 
01841   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01842     /* If we are currently on a tile with conventional signals, we can't treat the
01843      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01844     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01845       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01846       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01847 
01848     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01849     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01850 
01851     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01852     if (TryPathReserve(v, false, first_tile_okay)) {
01853       /* Do a look-ahead now in case our current tile was already a safe tile. */
01854       CheckNextTrainTile(v);
01855     } else if (v->current_order.GetType() != OT_LOADING) {
01856       /* Do not wait for a way out when we're still loading */
01857       MarkTrainAsStuck(v);
01858     }
01859   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01860     /* A train not inside a PBS block can't be stuck. */
01861     ClrBit(v->flags, VRF_TRAIN_STUCK);
01862     v->wait_counter = 0;
01863   }
01864 }
01865 
01875 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01876 {
01877   Train *v = Train::GetIfValid(p1);
01878   if (v == NULL) return CMD_ERROR;
01879 
01880   CommandCost ret = CheckOwnership(v->owner);
01881   if (ret.Failed()) return ret;
01882 
01883   if (p2 != 0) {
01884     /* turn a single unit around */
01885 
01886     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01887       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01888     }
01889     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01890 
01891     Train *front = v->First();
01892     /* make sure the vehicle is stopped in the depot */
01893     if (!front->IsStoppedInDepot()) {
01894       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01895     }
01896 
01897     if (flags & DC_EXEC) {
01898       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01899 
01900       front->ConsistChanged(false);
01901       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01902       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01903       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01904       SetWindowClassesDirty(WC_TRAINS_LIST);
01905     }
01906   } else {
01907     /* turn the whole train around */
01908     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01909 
01910     if (flags & DC_EXEC) {
01911       /* Properly leave the station if we are loading and won't be loading anymore */
01912       if (v->current_order.IsType(OT_LOADING)) {
01913         const Vehicle *last = v;
01914         while (last->Next() != NULL) last = last->Next();
01915 
01916         /* not a station || different station --> leave the station */
01917         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01918           v->LeaveStation();
01919         }
01920       }
01921 
01922       /* We cancel any 'skip signal at dangers' here */
01923       v->force_proceed = TFP_NONE;
01924       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01925 
01926       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01927         ToggleBit(v->flags, VRF_REVERSING);
01928       } else {
01929         v->cur_speed = 0;
01930         v->SetLastSpeed();
01931         HideFillingPercent(&v->fill_percent_te_id);
01932         ReverseTrainDirection(v);
01933       }
01934     }
01935   }
01936   return CommandCost();
01937 }
01938 
01948 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01949 {
01950   Train *t = Train::GetIfValid(p1);
01951   if (t == NULL) return CMD_ERROR;
01952 
01953   if (!t->IsPrimaryVehicle()) return CMD_ERROR;
01954 
01955   CommandCost ret = CheckOwnership(t->owner);
01956   if (ret.Failed()) return ret;
01957 
01958 
01959   if (flags & DC_EXEC) {
01960     /* If we are forced to proceed, cancel that order.
01961      * If we are marked stuck we would want to force the train
01962      * to proceed to the next signal. In the other cases we
01963      * would like to pass the signal at danger and run till the
01964      * next signal we encounter. */
01965     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsChainInDepot() ? TFP_STUCK : TFP_SIGNAL;
01966     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01967   }
01968 
01969   return CommandCost();
01970 }
01971 
01979 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01980 {
01981   assert(!(v->vehstatus & VS_CRASHED));
01982 
01983   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01984 
01985   PBSTileInfo origin = FollowTrainReservation(v);
01986   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01987 
01988   switch (_settings_game.pf.pathfinder_for_trains) {
01989     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01990     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01991 
01992     default: NOT_REACHED();
01993   }
01994 }
01995 
02003 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
02004 {
02005   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
02006   if (tfdd.best_length == UINT_MAX) return false;
02007 
02008   if (location    != NULL) *location    = tfdd.tile;
02009   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
02010   if (reverse     != NULL) *reverse     = tfdd.reverse;
02011 
02012   return true;
02013 }
02014 
02016 void Train::PlayLeaveStationSound() const
02017 {
02018   static const SoundFx sfx[] = {
02019     SND_04_TRAIN,
02020     SND_0A_TRAIN_HORN,
02021     SND_0A_TRAIN_HORN,
02022     SND_47_MAGLEV_2,
02023     SND_41_MAGLEV
02024   };
02025 
02026   if (PlayVehicleSound(this, VSE_START)) return;
02027 
02028   EngineID engtype = this->engine_type;
02029   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02030 }
02031 
02036 static void CheckNextTrainTile(Train *v)
02037 {
02038   /* Don't do any look-ahead if path_backoff_interval is 255. */
02039   if (_settings_game.pf.path_backoff_interval == 255) return;
02040 
02041   /* Exit if we are inside a depot. */
02042   if (v->track == TRACK_BIT_DEPOT) return;
02043 
02044   switch (v->current_order.GetType()) {
02045     /* Exit if we reached our destination depot. */
02046     case OT_GOTO_DEPOT:
02047       if (v->tile == v->dest_tile) return;
02048       break;
02049 
02050     case OT_GOTO_WAYPOINT:
02051       /* If we reached our waypoint, make sure we see that. */
02052       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02053       break;
02054 
02055     case OT_NOTHING:
02056     case OT_LEAVESTATION:
02057     case OT_LOADING:
02058       /* Exit if the current order doesn't have a destination, but the train has orders. */
02059       if (v->GetNumOrders() > 0) return;
02060       break;
02061 
02062     default:
02063       break;
02064   }
02065   /* Exit if we are on a station tile and are going to stop. */
02066   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02067 
02068   Trackdir td = v->GetVehicleTrackdir();
02069 
02070   /* On a tile with a red non-pbs signal, don't look ahead. */
02071   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02072       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02073       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02074 
02075   CFollowTrackRail ft(v);
02076   if (!ft.Follow(v->tile, td)) return;
02077 
02078   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02079     /* Next tile is not reserved. */
02080     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02081       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02082         /* If the next tile is a PBS signal, try to make a reservation. */
02083         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02084         if (_settings_game.pf.forbid_90_deg) {
02085           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02086         }
02087         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02088       }
02089     }
02090   }
02091 }
02092 
02098 static bool CheckTrainStayInDepot(Train *v)
02099 {
02100   /* bail out if not all wagons are in the same depot or not in a depot at all */
02101   for (const Train *u = v; u != NULL; u = u->Next()) {
02102     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02103   }
02104 
02105   /* if the train got no power, then keep it in the depot */
02106   if (v->gcache.cached_power == 0) {
02107     v->vehstatus |= VS_STOPPED;
02108     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02109     return true;
02110   }
02111 
02112   SigSegState seg_state;
02113 
02114   if (v->force_proceed == TFP_NONE) {
02115     /* force proceed was not pressed */
02116     if (++v->wait_counter < 37) {
02117       SetWindowClassesDirty(WC_TRAINS_LIST);
02118       return true;
02119     }
02120 
02121     v->wait_counter = 0;
02122 
02123     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02124     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02125       /* Full and no PBS signal in block or depot reserved, can't exit. */
02126       SetWindowClassesDirty(WC_TRAINS_LIST);
02127       return true;
02128     }
02129   } else {
02130     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02131   }
02132 
02133   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02134   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02135     /* We need to have a reservation for this to work. */
02136     if (HasDepotReservation(v->tile)) return true;
02137     SetDepotReservation(v->tile, true);
02138     VehicleEnterDepot(v);
02139     return true;
02140   }
02141 
02142   /* Only leave when we can reserve a path to our destination. */
02143   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02144     /* No path and no force proceed. */
02145     SetWindowClassesDirty(WC_TRAINS_LIST);
02146     MarkTrainAsStuck(v);
02147     return true;
02148   }
02149 
02150   SetDepotReservation(v->tile, true);
02151   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02152 
02153   VehicleServiceInDepot(v);
02154   SetWindowClassesDirty(WC_TRAINS_LIST);
02155   v->PlayLeaveStationSound();
02156 
02157   v->track = TRACK_BIT_X;
02158   if (v->direction & 2) v->track = TRACK_BIT_Y;
02159 
02160   v->vehstatus &= ~VS_HIDDEN;
02161   v->cur_speed = 0;
02162 
02163   v->UpdateViewport(true, true);
02164   VehicleUpdatePosition(v);
02165   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02166   v->UpdateAcceleration();
02167   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02168 
02169   return false;
02170 }
02171 
02178 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02179 {
02180   DiagDirection dir = TrackdirToExitdir(track_dir);
02181 
02182   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02183     /* Are we just leaving a tunnel/bridge? */
02184     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02185       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02186 
02187       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02188         /* Free the reservation only if no other train is on the tiles. */
02189         SetTunnelBridgeReservation(tile, false);
02190         SetTunnelBridgeReservation(end, false);
02191 
02192         if (_settings_client.gui.show_track_reservation) {
02193           MarkTileDirtyByTile(tile);
02194           MarkTileDirtyByTile(end);
02195         }
02196       }
02197     }
02198   } else if (IsRailStationTile(tile)) {
02199     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02200     /* If the new tile is not a further tile of the same station, we
02201      * clear the reservation for the whole platform. */
02202     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02203       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02204     }
02205   } else {
02206     /* Any other tile */
02207     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02208   }
02209 }
02210 
02217 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02218 {
02219   assert(v->IsFrontEngine());
02220 
02221   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02222   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02223   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02224   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02225 
02226   /* Can't be holding a reservation if we enter a depot. */
02227   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02228   if (v->track == TRACK_BIT_DEPOT) {
02229     /* Front engine is in a depot. We enter if some part is not in the depot. */
02230     for (const Train *u = v; u != NULL; u = u->Next()) {
02231       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02232     }
02233   }
02234   /* Don't free reservation if it's not ours. */
02235   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02236 
02237   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02238   while (ft.Follow(tile, td)) {
02239     tile = ft.m_new_tile;
02240     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02241     td = RemoveFirstTrackdir(&bits);
02242     assert(bits == TRACKDIR_BIT_NONE);
02243 
02244     if (!IsValidTrackdir(td)) break;
02245 
02246     if (IsTileType(tile, MP_RAILWAY)) {
02247       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02248         /* Conventional signal along trackdir: remove reservation and stop. */
02249         UnreserveRailTrack(tile, TrackdirToTrack(td));
02250         break;
02251       }
02252       if (HasPbsSignalOnTrackdir(tile, td)) {
02253         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02254           /* Red PBS signal? Can't be our reservation, would be green then. */
02255           break;
02256         } else {
02257           /* Turn the signal back to red. */
02258           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02259           MarkTileDirtyByTile(tile);
02260         }
02261       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02262         break;
02263       }
02264     }
02265 
02266     /* Don't free first station/bridge/tunnel if we are on it. */
02267     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);
02268 
02269     free_tile = true;
02270   }
02271 }
02272 
02273 static const byte _initial_tile_subcoord[6][4][3] = {
02274 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02275 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02276 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02277 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02278 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02279 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02280 };
02281 
02294 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02295 {
02296   switch (_settings_game.pf.pathfinder_for_trains) {
02297     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02298     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02299 
02300     default: NOT_REACHED();
02301   }
02302 }
02303 
02309 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02310 {
02311   PBSTileInfo origin = FollowTrainReservation(v);
02312 
02313   CFollowTrackRail ft(v);
02314 
02315   TileIndex tile = origin.tile;
02316   Trackdir  cur_td = origin.trackdir;
02317   while (ft.Follow(tile, cur_td)) {
02318     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02319       /* Possible signal tile. */
02320       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02321     }
02322 
02323     if (_settings_game.pf.forbid_90_deg) {
02324       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02325       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02326     }
02327 
02328     /* Station, depot or waypoint are a possible target. */
02329     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02330     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02331       /* Choice found or possible target encountered.
02332        * On finding a possible target, we need to stop and let the pathfinder handle the
02333        * remaining path. This is because we don't know if this target is in one of our
02334        * orders, so we might cause pathfinding to fail later on if we find a choice.
02335        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02336        * a wrong path not leading to our next destination. */
02337       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02338 
02339       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02340        * actually starts its search at the first unreserved tile. */
02341       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02342 
02343       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02344       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02345       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02346       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02347     }
02348 
02349     tile = ft.m_new_tile;
02350     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02351 
02352     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02353       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02354       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02355       /* Safe position is all good, path valid and okay. */
02356       return PBSTileInfo(tile, cur_td, true);
02357     }
02358 
02359     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02360   }
02361 
02362   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02363     /* End of line, path valid and okay. */
02364     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02365   }
02366 
02367   /* Sorry, can't reserve path, back out. */
02368   tile = origin.tile;
02369   cur_td = origin.trackdir;
02370   TileIndex stopped = ft.m_old_tile;
02371   Trackdir  stopped_td = ft.m_old_td;
02372   while (tile != stopped || cur_td != stopped_td) {
02373     if (!ft.Follow(tile, cur_td)) break;
02374 
02375     if (_settings_game.pf.forbid_90_deg) {
02376       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02377       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02378     }
02379     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02380 
02381     tile = ft.m_new_tile;
02382     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02383 
02384     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02385   }
02386 
02387   /* Path invalid. */
02388   return PBSTileInfo();
02389 }
02390 
02401 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02402 {
02403   switch (_settings_game.pf.pathfinder_for_trains) {
02404     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02405     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02406 
02407     default: NOT_REACHED();
02408   }
02409 }
02410 
02412 class VehicleOrderSaver {
02413 private:
02414   Train          *v;
02415   Order          old_order;
02416   TileIndex      old_dest_tile;
02417   StationID      old_last_station_visited;
02418   VehicleOrderID index;
02419   bool           suppress_implicit_orders;
02420 
02421 public:
02422   VehicleOrderSaver(Train *_v) :
02423     v(_v),
02424     old_order(_v->current_order),
02425     old_dest_tile(_v->dest_tile),
02426     old_last_station_visited(_v->last_station_visited),
02427     index(_v->cur_real_order_index),
02428     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02429   {
02430   }
02431 
02432   ~VehicleOrderSaver()
02433   {
02434     this->v->current_order = this->old_order;
02435     this->v->dest_tile = this->old_dest_tile;
02436     this->v->last_station_visited = this->old_last_station_visited;
02437     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02438   }
02439 
02445   bool SwitchToNextOrder(bool skip_first)
02446   {
02447     if (this->v->GetNumOrders() == 0) return false;
02448 
02449     if (skip_first) ++this->index;
02450 
02451     int depth = 0;
02452 
02453     do {
02454       /* Wrap around. */
02455       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02456 
02457       Order *order = this->v->GetOrder(this->index);
02458       assert(order != NULL);
02459 
02460       switch (order->GetType()) {
02461         case OT_GOTO_DEPOT:
02462           /* Skip service in depot orders when the train doesn't need service. */
02463           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02464         case OT_GOTO_STATION:
02465         case OT_GOTO_WAYPOINT:
02466           this->v->current_order = *order;
02467           return UpdateOrderDest(this->v, order, 0, true);
02468         case OT_CONDITIONAL: {
02469           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02470           if (next != INVALID_VEH_ORDER_ID) {
02471             depth++;
02472             this->index = next;
02473             /* Don't increment next, so no break here. */
02474             continue;
02475           }
02476           break;
02477         }
02478         default:
02479           break;
02480       }
02481       /* Don't increment inside the while because otherwise conditional
02482        * orders can lead to an infinite loop. */
02483       ++this->index;
02484       depth++;
02485     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02486 
02487     return false;
02488   }
02489 };
02490 
02491 /* choose a track */
02492 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02493 {
02494   Track best_track = INVALID_TRACK;
02495   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02496   bool changed_signal = false;
02497 
02498   assert((tracks & ~TRACK_BIT_MASK) == 0);
02499 
02500   if (got_reservation != NULL) *got_reservation = false;
02501 
02502   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02503   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02504   /* Do we have a suitable reserved track? */
02505   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02506 
02507   /* Quick return in case only one possible track is available */
02508   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02509     Track track = FindFirstTrack(tracks);
02510     /* We need to check for signals only here, as a junction tile can't have signals. */
02511     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02512       do_track_reservation = true;
02513       changed_signal = true;
02514       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02515     } else if (!do_track_reservation) {
02516       return track;
02517     }
02518     best_track = track;
02519   }
02520 
02521   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02522   DiagDirection dest_enterdir = enterdir;
02523   if (do_track_reservation) {
02524     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02525     if (res_dest.tile == INVALID_TILE) {
02526       /* Reservation failed? */
02527       if (mark_stuck) MarkTrainAsStuck(v);
02528       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02529       return FindFirstTrack(tracks);
02530     }
02531     if (res_dest.okay) {
02532       /* Got a valid reservation that ends at a safe target, quick exit. */
02533       if (got_reservation != NULL) *got_reservation = true;
02534       if (changed_signal) MarkTileDirtyByTile(tile);
02535       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02536       return best_track;
02537     }
02538 
02539     /* Check if the train needs service here, so it has a chance to always find a depot.
02540      * Also check if the current order is a service order so we don't reserve a path to
02541      * the destination but instead to the next one if service isn't needed. */
02542     CheckIfTrainNeedsService(v);
02543     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02544   }
02545 
02546   /* Save the current train order. The destructor will restore the old order on function exit. */
02547   VehicleOrderSaver orders(v);
02548 
02549   /* If the current tile is the destination of the current order and
02550    * a reservation was requested, advance to the next order.
02551    * Don't advance on a depot order as depots are always safe end points
02552    * for a path and no look-ahead is necessary. This also avoids a
02553    * problem with depot orders not part of the order list when the
02554    * order list itself is empty. */
02555   if (v->current_order.IsType(OT_LEAVESTATION)) {
02556     orders.SwitchToNextOrder(false);
02557   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02558       v->current_order.IsType(OT_GOTO_STATION) ?
02559       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02560       v->tile == v->dest_tile))) {
02561     orders.SwitchToNextOrder(true);
02562   }
02563 
02564   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02565     /* Pathfinders are able to tell that route was only 'guessed'. */
02566     bool      path_found = true;
02567     TileIndex new_tile = res_dest.tile;
02568 
02569     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02570     if (new_tile == tile) best_track = next_track;
02571     v->HandlePathfindingResult(path_found);
02572   }
02573 
02574   /* No track reservation requested -> finished. */
02575   if (!do_track_reservation) return best_track;
02576 
02577   /* A path was found, but could not be reserved. */
02578   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02579     if (mark_stuck) MarkTrainAsStuck(v);
02580     FreeTrainTrackReservation(v);
02581     return best_track;
02582   }
02583 
02584   /* No possible reservation target found, we are probably lost. */
02585   if (res_dest.tile == INVALID_TILE) {
02586     /* Try to find any safe destination. */
02587     PBSTileInfo origin = FollowTrainReservation(v);
02588     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02589       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02590       best_track = FindFirstTrack(res);
02591       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02592       if (got_reservation != NULL) *got_reservation = true;
02593       if (changed_signal) MarkTileDirtyByTile(tile);
02594     } else {
02595       FreeTrainTrackReservation(v);
02596       if (mark_stuck) MarkTrainAsStuck(v);
02597     }
02598     return best_track;
02599   }
02600 
02601   if (got_reservation != NULL) *got_reservation = true;
02602 
02603   /* Reservation target found and free, check if it is safe. */
02604   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02605     /* Extend reservation until we have found a safe position. */
02606     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02607     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02608     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02609     if (_settings_game.pf.forbid_90_deg) {
02610       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02611     }
02612 
02613     /* Get next order with destination. */
02614     if (orders.SwitchToNextOrder(true)) {
02615       PBSTileInfo cur_dest;
02616       bool path_found;
02617       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02618       if (cur_dest.tile != INVALID_TILE) {
02619         res_dest = cur_dest;
02620         if (res_dest.okay) continue;
02621         /* Path found, but could not be reserved. */
02622         FreeTrainTrackReservation(v);
02623         if (mark_stuck) MarkTrainAsStuck(v);
02624         if (got_reservation != NULL) *got_reservation = false;
02625         changed_signal = false;
02626         break;
02627       }
02628     }
02629     /* No order or no safe position found, try any position. */
02630     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02631       FreeTrainTrackReservation(v);
02632       if (mark_stuck) MarkTrainAsStuck(v);
02633       if (got_reservation != NULL) *got_reservation = false;
02634       changed_signal = false;
02635     }
02636     break;
02637   }
02638 
02639   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02640 
02641   if (changed_signal) MarkTileDirtyByTile(tile);
02642 
02643   return best_track;
02644 }
02645 
02654 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02655 {
02656   assert(v->IsFrontEngine());
02657 
02658   /* We have to handle depots specially as the track follower won't look
02659    * at the depot tile itself but starts from the next tile. If we are still
02660    * inside the depot, a depot reservation can never be ours. */
02661   if (v->track == TRACK_BIT_DEPOT) {
02662     if (HasDepotReservation(v->tile)) {
02663       if (mark_as_stuck) MarkTrainAsStuck(v);
02664       return false;
02665     } else {
02666       /* Depot not reserved, but the next tile might be. */
02667       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02668       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02669     }
02670   }
02671 
02672   Vehicle *other_train = NULL;
02673   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02674   /* The path we are driving on is already blocked by some other train.
02675    * This can only happen in certain situations when mixing path and
02676    * block signals or when changing tracks and/or signals.
02677    * Exit here as doing any further reservations will probably just
02678    * make matters worse. */
02679   if (other_train != NULL && other_train->index != v->index) {
02680     if (mark_as_stuck) MarkTrainAsStuck(v);
02681     return false;
02682   }
02683   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02684   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02685     /* Can't be stuck then. */
02686     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02687     ClrBit(v->flags, VRF_TRAIN_STUCK);
02688     return true;
02689   }
02690 
02691   /* If we are in a depot, tentatively reserve the depot. */
02692   if (v->track == TRACK_BIT_DEPOT) {
02693     SetDepotReservation(v->tile, true);
02694     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02695   }
02696 
02697   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02698   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02699   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02700 
02701   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02702 
02703   bool res_made = false;
02704   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02705 
02706   if (!res_made) {
02707     /* Free the depot reservation as well. */
02708     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02709     return false;
02710   }
02711 
02712   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02713     v->wait_counter = 0;
02714     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02715   }
02716   ClrBit(v->flags, VRF_TRAIN_STUCK);
02717   return true;
02718 }
02719 
02720 
02721 static bool CheckReverseTrain(const Train *v)
02722 {
02723   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02724       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02725       !(v->direction & 1)) {
02726     return false;
02727   }
02728 
02729   assert(v->track != TRACK_BIT_NONE);
02730 
02731   switch (_settings_game.pf.pathfinder_for_trains) {
02732     case VPF_NPF: return NPFTrainCheckReverse(v);
02733     case VPF_YAPF: return YapfTrainCheckReverse(v);
02734 
02735     default: NOT_REACHED();
02736   }
02737 }
02738 
02744 TileIndex Train::GetOrderStationLocation(StationID station)
02745 {
02746   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02747 
02748   const Station *st = Station::Get(station);
02749   if (!(st->facilities & FACIL_TRAIN)) {
02750     /* The destination station has no trainstation tiles. */
02751     this->IncrementRealOrderIndex();
02752     return 0;
02753   }
02754 
02755   return st->xy;
02756 }
02757 
02759 void Train::MarkDirty()
02760 {
02761   Train *v = this;
02762   do {
02763     v->UpdateViewport(false, false);
02764   } while ((v = v->Next()) != NULL);
02765 
02766   /* need to update acceleration and cached values since the goods on the train changed. */
02767   this->CargoChanged();
02768   this->UpdateAcceleration();
02769 }
02770 
02778 int Train::UpdateSpeed()
02779 {
02780   switch (_settings_game.vehicle.train_acceleration_model) {
02781     default: NOT_REACHED();
02782     case AM_ORIGINAL:
02783       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, min(this->gcache.cached_max_track_speed, this->current_order.max_speed));
02784 
02785     case AM_REALISTIC:
02786       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02787   }
02788 }
02789 
02795 static void TrainEnterStation(Train *v, StationID station)
02796 {
02797   v->last_station_visited = station;
02798 
02799   /* check if a train ever visited this station before */
02800   Station *st = Station::Get(station);
02801   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02802     st->had_vehicle_of_type |= HVOT_TRAIN;
02803     SetDParam(0, st->index);
02804     AddVehicleNewsItem(
02805       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02806       v->owner == _local_company ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
02807       v->index,
02808       st->index
02809     );
02810     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02811     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02812   }
02813 
02814   v->force_proceed = TFP_NONE;
02815   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02816 
02817   v->BeginLoading();
02818 
02819   TriggerStationRandomisation(st, v->tile, SRT_TRAIN_ARRIVES);
02820   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02821 }
02822 
02823 /* Check if the vehicle is compatible with the specified tile */
02824 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02825 {
02826   return IsTileOwner(tile, v->owner) &&
02827       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02828 }
02829 
02831 struct AccelerationSlowdownParams {
02832   byte small_turn; 
02833   byte large_turn; 
02834   byte z_up;       
02835   byte z_down;     
02836 };
02837 
02839 static const AccelerationSlowdownParams _accel_slowdown[] = {
02840   /* normal accel */
02841   {256 / 4, 256 / 2, 256 / 4, 2}, 
02842   {256 / 4, 256 / 2, 256 / 4, 2}, 
02843   {0,       256 / 2, 256 / 4, 2}, 
02844 };
02845 
02851 static inline void AffectSpeedByZChange(Train *v, int old_z)
02852 {
02853   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02854 
02855   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02856 
02857   if (old_z < v->z_pos) {
02858     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02859   } else {
02860     uint16 spd = v->cur_speed + asp->z_down;
02861     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02862   }
02863 }
02864 
02865 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02866 {
02867   if (IsTileType(tile, MP_RAILWAY) &&
02868       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02869     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02870     Trackdir trackdir = FindFirstTrackdir(tracks);
02871     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02872       /* A PBS block with a non-PBS signal facing us? */
02873       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02874     }
02875   }
02876   return false;
02877 }
02878 
02880 void Train::ReserveTrackUnderConsist() const
02881 {
02882   for (const Train *u = this; u != NULL; u = u->Next()) {
02883     switch (u->track) {
02884       case TRACK_BIT_WORMHOLE:
02885         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02886         break;
02887       case TRACK_BIT_DEPOT:
02888         break;
02889       default:
02890         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02891         break;
02892     }
02893   }
02894 }
02895 
02902 uint Train::Crash(bool flooded)
02903 {
02904   uint pass = 0;
02905   if (this->IsFrontEngine()) {
02906     pass += 2; // driver
02907 
02908     /* Remove the reserved path in front of the train if it is not stuck.
02909      * Also clear all reserved tracks the train is currently on. */
02910     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02911     for (const Train *v = this; v != NULL; v = v->Next()) {
02912       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02913       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02914         /* ClearPathReservation will not free the wormhole exit
02915          * if the train has just entered the wormhole. */
02916         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02917       }
02918     }
02919 
02920     /* we may need to update crossing we were approaching,
02921      * but must be updated after the train has been marked crashed */
02922     TileIndex crossing = TrainApproachingCrossingTile(this);
02923     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02924 
02925     /* Remove the loading indicators (if any) */
02926     HideFillingPercent(&this->fill_percent_te_id);
02927   }
02928 
02929   pass += this->GroundVehicleBase::Crash(flooded);
02930 
02931   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02932   return pass;
02933 }
02934 
02941 static uint TrainCrashed(Train *v)
02942 {
02943   uint num = 0;
02944 
02945   /* do not crash train twice */
02946   if (!(v->vehstatus & VS_CRASHED)) {
02947     num = v->Crash();
02948     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02949     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02950   }
02951 
02952   /* Try to re-reserve track under already crashed train too.
02953    * Crash() clears the reservation! */
02954   v->ReserveTrackUnderConsist();
02955 
02956   return num;
02957 }
02958 
02960 struct TrainCollideChecker {
02961   Train *v; 
02962   uint num; 
02963 };
02964 
02971 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02972 {
02973   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02974 
02975   /* not a train or in depot */
02976   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02977 
02978   /* do not crash into trains of another company. */
02979   if (v->owner != tcc->v->owner) return NULL;
02980 
02981   /* get first vehicle now to make most usual checks faster */
02982   Train *coll = Train::From(v)->First();
02983 
02984   /* can't collide with own wagons */
02985   if (coll == tcc->v) return NULL;
02986 
02987   int x_diff = v->x_pos - tcc->v->x_pos;
02988   int y_diff = v->y_pos - tcc->v->y_pos;
02989 
02990   /* Do fast calculation to check whether trains are not in close vicinity
02991    * and quickly reject trains distant enough for any collision.
02992    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02993    * Differences are then ORed and then we check for any higher bits */
02994   uint hash = (y_diff + 7) | (x_diff + 7);
02995   if (hash & ~15) return NULL;
02996 
02997   /* Slower check using multiplication */
02998   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02999   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
03000 
03001   /* Happens when there is a train under bridge next to bridge head */
03002   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
03003 
03004   /* crash both trains */
03005   tcc->num += TrainCrashed(tcc->v);
03006   tcc->num += TrainCrashed(coll);
03007 
03008   return NULL; // continue searching
03009 }
03010 
03018 static bool CheckTrainCollision(Train *v)
03019 {
03020   /* can't collide in depot */
03021   if (v->track == TRACK_BIT_DEPOT) return false;
03022 
03023   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03024 
03025   TrainCollideChecker tcc;
03026   tcc.v = v;
03027   tcc.num = 0;
03028 
03029   /* find colliding vehicles */
03030   if (v->track == TRACK_BIT_WORMHOLE) {
03031     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03032     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03033   } else {
03034     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03035   }
03036 
03037   /* any dead -> no crash */
03038   if (tcc.num == 0) return false;
03039 
03040   SetDParam(0, tcc.num);
03041   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH, NT_ACCIDENT, v->index);
03042 
03043   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03044   if (_settings_client.sound.disaster) SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03045   return true;
03046 }
03047 
03048 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03049 {
03050   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03051 
03052   Train *t = Train::From(v);
03053   DiagDirection exitdir = *(DiagDirection *)data;
03054 
03055   /* not front engine of a train, inside wormhole or depot, crashed */
03056   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03057 
03058   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03059 
03060   return t;
03061 }
03062 
03070 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03071 {
03072   Train *first = v->First();
03073   Train *prev;
03074   bool direction_changed = false; // has direction of any part changed?
03075 
03076   /* For every vehicle after and including the given vehicle */
03077   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03078     DiagDirection enterdir = DIAGDIR_BEGIN;
03079     bool update_signals_crossing = false; // will we update signals or crossing state?
03080 
03081     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03082     if (v->track != TRACK_BIT_WORMHOLE) {
03083       /* Not inside tunnel */
03084       if (gp.old_tile == gp.new_tile) {
03085         /* Staying in the old tile */
03086         if (v->track == TRACK_BIT_DEPOT) {
03087           /* Inside depot */
03088           gp.x = v->x_pos;
03089           gp.y = v->y_pos;
03090         } else {
03091           /* Not inside depot */
03092 
03093           /* Reverse when we are at the end of the track already, do not move to the new position */
03094           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03095 
03096           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03097           if (HasBit(r, VETS_CANNOT_ENTER)) {
03098             goto invalid_rail;
03099           }
03100           if (HasBit(r, VETS_ENTERED_STATION)) {
03101             /* The new position is the end of the platform */
03102             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03103           }
03104         }
03105       } else {
03106         /* A new tile is about to be entered. */
03107 
03108         /* Determine what direction we're entering the new tile from */
03109         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03110         assert(IsValidDiagDirection(enterdir));
03111 
03112         /* Get the status of the tracks in the new tile and mask
03113          * away the bits that aren't reachable. */
03114         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03115         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03116 
03117         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03118         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03119 
03120         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03121         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03122           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03123            * can be switched on halfway a turn */
03124           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03125         }
03126 
03127         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03128 
03129         /* Check if the new tile constrains tracks that are compatible
03130          * with the current train, if not, bail out. */
03131         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03132 
03133         TrackBits chosen_track;
03134         if (prev == NULL) {
03135           /* Currently the locomotive is active. Determine which one of the
03136            * available tracks to choose */
03137           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03138           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03139 
03140           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03141             /* For each signal we find decrease the counter by one.
03142              * We start at two, so the first signal we pass decreases
03143              * this to one, then if we reach the next signal it is
03144              * decreased to zero and we won't pass that new signal. */
03145             Trackdir dir = FindFirstTrackdir(trackdirbits);
03146             if (GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS ||
03147                 !HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir))) {
03148               /* However, we do not want to be stopped by PBS signals
03149                * entered via the back. */
03150               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03151               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03152             }
03153           }
03154 
03155           /* Check if it's a red signal and that force proceed is not clicked. */
03156           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03157             /* In front of a red signal */
03158             Trackdir i = FindFirstTrackdir(trackdirbits);
03159 
03160             /* Don't handle stuck trains here. */
03161             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03162 
03163             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03164               v->cur_speed = 0;
03165               v->subspeed = 0;
03166               v->progress = 255 - 100;
03167               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03168             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03169               v->cur_speed = 0;
03170               v->subspeed = 0;
03171               v->progress = 255 - 10;
03172               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03173                 DiagDirection exitdir = TrackdirToExitdir(i);
03174                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03175 
03176                 exitdir = ReverseDiagDir(exitdir);
03177 
03178                 /* check if a train is waiting on the other side */
03179                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03180               }
03181             }
03182 
03183             /* If we would reverse but are currently in a PBS block and
03184              * reversing of stuck trains is disabled, don't reverse.
03185              * This does not apply if the reason for reversing is a one-way
03186              * signal blocking us, because a train would then be stuck forever. */
03187             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03188                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03189               v->wait_counter = 0;
03190               return false;
03191             }
03192             goto reverse_train_direction;
03193           } else {
03194             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track), false);
03195           }
03196         } else {
03197           /* The wagon is active, simply follow the prev vehicle. */
03198           if (prev->tile == gp.new_tile) {
03199             /* Choose the same track as prev */
03200             if (prev->track == TRACK_BIT_WORMHOLE) {
03201               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03202                * However, just choose the track into the wormhole. */
03203               assert(IsTunnel(prev->tile));
03204               chosen_track = bits;
03205             } else {
03206               chosen_track = prev->track;
03207             }
03208           } else {
03209             /* Choose the track that leads to the tile where prev is.
03210              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03211              * I.e. when the tile between them has only space for a single vehicle like
03212              *  1) horizontal/vertical track tiles and
03213              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03214              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03215              */
03216             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03217               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03218               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03219               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03220               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03221             };
03222             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03223             assert(IsValidDiagDirection(exitdir));
03224             chosen_track = _connecting_track[enterdir][exitdir];
03225           }
03226           chosen_track &= bits;
03227         }
03228 
03229         /* Make sure chosen track is a valid track */
03230         assert(
03231             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03232             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03233             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03234 
03235         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03236         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03237         gp.x = (gp.x & ~0xF) | b[0];
03238         gp.y = (gp.y & ~0xF) | b[1];
03239         Direction chosen_dir = (Direction)b[2];
03240 
03241         /* Call the landscape function and tell it that the vehicle entered the tile */
03242         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03243         if (HasBit(r, VETS_CANNOT_ENTER)) {
03244           goto invalid_rail;
03245         }
03246 
03247         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03248           Track track = FindFirstTrack(chosen_track);
03249           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03250           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03251             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03252             MarkTileDirtyByTile(gp.new_tile);
03253           }
03254 
03255           /* Clear any track reservation when the last vehicle leaves the tile */
03256           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03257 
03258           v->tile = gp.new_tile;
03259 
03260           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03261             v->First()->ConsistChanged(true);
03262           }
03263 
03264           v->track = chosen_track;
03265           assert(v->track);
03266         }
03267 
03268         /* We need to update signal status, but after the vehicle position hash
03269          * has been updated by UpdateInclination() */
03270         update_signals_crossing = true;
03271 
03272         if (chosen_dir != v->direction) {
03273           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03274             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03275             DirDiff diff = DirDifference(v->direction, chosen_dir);
03276             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03277           }
03278           direction_changed = true;
03279           v->direction = chosen_dir;
03280         }
03281 
03282         if (v->IsFrontEngine()) {
03283           v->wait_counter = 0;
03284 
03285           /* If we are approaching a crossing that is reserved, play the sound now. */
03286           TileIndex crossing = TrainApproachingCrossingTile(v);
03287           if (crossing != INVALID_TILE && HasCrossingReservation(crossing) && _settings_client.sound.new_year) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03288 
03289           /* Always try to extend the reservation when entering a tile. */
03290           CheckNextTrainTile(v);
03291         }
03292 
03293         if (HasBit(r, VETS_ENTERED_STATION)) {
03294           /* The new position is the location where we want to stop */
03295           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03296         }
03297       }
03298     } else {
03299       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03300         /* Perform look-ahead on tunnel exit. */
03301         if (v->IsFrontEngine()) {
03302           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03303           CheckNextTrainTile(v);
03304         }
03305         /* Prevent v->UpdateInclination() being called with wrong parameters.
03306          * This could happen if the train was reversed inside the tunnel/bridge. */
03307         if (gp.old_tile == gp.new_tile) {
03308           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03309         }
03310       } else {
03311         v->x_pos = gp.x;
03312         v->y_pos = gp.y;
03313         VehicleUpdatePosition(v);
03314         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03315         continue;
03316       }
03317     }
03318 
03319     /* update image of train, as well as delta XY */
03320     v->UpdateDeltaXY(v->direction);
03321 
03322     v->x_pos = gp.x;
03323     v->y_pos = gp.y;
03324     VehicleUpdatePosition(v);
03325 
03326     /* update the Z position of the vehicle */
03327     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03328 
03329     if (prev == NULL) {
03330       /* This is the first vehicle in the train */
03331       AffectSpeedByZChange(v, old_z);
03332     }
03333 
03334     if (update_signals_crossing) {
03335       if (v->IsFrontEngine()) {
03336         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03337           /* We are entering a block with PBS signals right now, but
03338            * not through a PBS signal. This means we don't have a
03339            * reservation right now. As a conventional signal will only
03340            * ever be green if no other train is in the block, getting
03341            * a path should always be possible. If the player built
03342            * such a strange network that it is not possible, the train
03343            * will be marked as stuck and the player has to deal with
03344            * the problem. */
03345           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03346               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03347               !TryPathReserve(v)) {
03348             MarkTrainAsStuck(v);
03349           }
03350         }
03351       }
03352 
03353       /* Signals can only change when the first
03354        * (above) or the last vehicle moves. */
03355       if (v->Next() == NULL) {
03356         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03357         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03358       }
03359     }
03360 
03361     /* Do not check on every tick to save some computing time. */
03362     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03363   }
03364 
03365   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03366 
03367   return true;
03368 
03369 invalid_rail:
03370   /* We've reached end of line?? */
03371   if (prev != NULL) error("Disconnecting train");
03372 
03373 reverse_train_direction:
03374   if (reverse) {
03375     v->wait_counter = 0;
03376     v->cur_speed = 0;
03377     v->subspeed = 0;
03378     ReverseTrainDirection(v);
03379   }
03380 
03381   return false;
03382 }
03383 
03390 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03391 {
03392   TrackBits *trackbits = (TrackBits *)data;
03393 
03394   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03395     TrackBits train_tbits = Train::From(v)->track;
03396     if (train_tbits == TRACK_BIT_WORMHOLE) {
03397       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03398       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03399     } else if (train_tbits != TRACK_BIT_DEPOT) {
03400       *trackbits |= train_tbits;
03401     }
03402   }
03403 
03404   return NULL;
03405 }
03406 
03414 static void DeleteLastWagon(Train *v)
03415 {
03416   Train *first = v->First();
03417 
03418   /* Go to the last wagon and delete the link pointing there
03419    * *u is then the one-before-last wagon, and *v the last
03420    * one which will physically be removed */
03421   Train *u = v;
03422   for (; v->Next() != NULL; v = v->Next()) u = v;
03423   u->SetNext(NULL);
03424 
03425   if (first != v) {
03426     /* Recalculate cached train properties */
03427     first->ConsistChanged(false);
03428     /* Update the depot window if the first vehicle is in depot -
03429      * if v == first, then it is updated in PreDestructor() */
03430     if (first->track == TRACK_BIT_DEPOT) {
03431       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03432     }
03433   }
03434 
03435   /* 'v' shouldn't be accessed after it has been deleted */
03436   TrackBits trackbits = v->track;
03437   TileIndex tile = v->tile;
03438   Owner owner = v->owner;
03439 
03440   delete v;
03441   v = NULL; // make sure nobody will try to read 'v' anymore
03442 
03443   if (trackbits == TRACK_BIT_WORMHOLE) {
03444     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03445     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03446   }
03447 
03448   Track track = TrackBitsToTrack(trackbits);
03449   if (HasReservedTracks(tile, trackbits)) {
03450     UnreserveRailTrack(tile, track);
03451 
03452     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03453     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03454     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03455 
03456     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03457     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03458     Track t;
03459     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03460   }
03461 
03462   /* check if the wagon was on a road/rail-crossing */
03463   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03464 
03465   /* Update signals */
03466   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03467     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03468   } else {
03469     SetSignalsOnBothDir(tile, track, owner);
03470   }
03471 }
03472 
03477 static void ChangeTrainDirRandomly(Train *v)
03478 {
03479   static const DirDiff delta[] = {
03480     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03481   };
03482 
03483   do {
03484     /* We don't need to twist around vehicles if they're not visible */
03485     if (!(v->vehstatus & VS_HIDDEN)) {
03486       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03487       v->UpdateDeltaXY(v->direction);
03488       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03489       /* Refrain from updating the z position of the vehicle when on
03490        * a bridge, because UpdateInclination() will put the vehicle under
03491        * the bridge in that case */
03492       if (v->track != TRACK_BIT_WORMHOLE) {
03493         VehicleUpdatePosition(v);
03494         v->UpdateInclination(false, false);
03495       }
03496     }
03497   } while ((v = v->Next()) != NULL);
03498 }
03499 
03505 static bool HandleCrashedTrain(Train *v)
03506 {
03507   int state = ++v->crash_anim_pos;
03508 
03509   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03510     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03511   }
03512 
03513   uint32 r;
03514   if (state <= 200 && Chance16R(1, 7, r)) {
03515     int index = (r * 10 >> 16);
03516 
03517     Vehicle *u = v;
03518     do {
03519       if (--index < 0) {
03520         r = Random();
03521 
03522         CreateEffectVehicleRel(u,
03523           GB(r,  8, 3) + 2,
03524           GB(r, 16, 3) + 2,
03525           GB(r,  0, 3) + 5,
03526           EV_EXPLOSION_SMALL);
03527         break;
03528       }
03529     } while ((u = u->Next()) != NULL);
03530   }
03531 
03532   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03533 
03534   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03535     bool ret = v->Next() != NULL;
03536     DeleteLastWagon(v);
03537     return ret;
03538   }
03539 
03540   return true;
03541 }
03542 
03544 static const uint16 _breakdown_speeds[16] = {
03545   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03546 };
03547 
03548 
03557 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03558 {
03559   /* Calc position within the current tile */
03560   uint x = v->x_pos & 0xF;
03561   uint y = v->y_pos & 0xF;
03562 
03563   /* for diagonal directions, 'x' will be 0..15 -
03564    * for other directions, it will be 1, 3, 5, ..., 15 */
03565   switch (v->direction) {
03566     case DIR_N : x = ~x + ~y + 25; break;
03567     case DIR_NW: x = y;            // FALL THROUGH
03568     case DIR_NE: x = ~x + 16;      break;
03569     case DIR_E : x = ~x + y + 9;   break;
03570     case DIR_SE: x = y;            break;
03571     case DIR_S : x = x + y - 7;    break;
03572     case DIR_W : x = ~y + x + 9;   break;
03573     default: break;
03574   }
03575 
03576   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03577    * does not cross the tile boundary when we do reverse, but as the vehicle's
03578    * location is based on their center, use half a vehicle's length as offset.
03579    * Multiply the half-length by two for straight directions to compensate that
03580    * we only get odd x offsets there. */
03581   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03582     /* we are too near the tile end, reverse now */
03583     v->cur_speed = 0;
03584     if (reverse) ReverseTrainDirection(v);
03585     return false;
03586   }
03587 
03588   /* slow down */
03589   v->vehstatus |= VS_TRAIN_SLOWING;
03590   uint16 break_speed = _breakdown_speeds[x & 0xF];
03591   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03592 
03593   return true;
03594 }
03595 
03596 
03602 static bool TrainCanLeaveTile(const Train *v)
03603 {
03604   /* Exit if inside a tunnel/bridge or a depot */
03605   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03606 
03607   TileIndex tile = v->tile;
03608 
03609   /* entering a tunnel/bridge? */
03610   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03611     DiagDirection dir = GetTunnelBridgeDirection(tile);
03612     if (DiagDirToDir(dir) == v->direction) return false;
03613   }
03614 
03615   /* entering a depot? */
03616   if (IsRailDepotTile(tile)) {
03617     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03618     if (DiagDirToDir(dir) == v->direction) return false;
03619   }
03620 
03621   return true;
03622 }
03623 
03624 
03632 static TileIndex TrainApproachingCrossingTile(const Train *v)
03633 {
03634   assert(v->IsFrontEngine());
03635   assert(!(v->vehstatus & VS_CRASHED));
03636 
03637   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03638 
03639   DiagDirection dir = TrainExitDir(v->direction, v->track);
03640   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03641 
03642   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03643   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03644       !CheckCompatibleRail(v, tile)) {
03645     return INVALID_TILE;
03646   }
03647 
03648   return tile;
03649 }
03650 
03651 
03659 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03660 {
03661   /* First, handle broken down train */
03662 
03663   int t = v->breakdown_ctr;
03664   if (t > 1) {
03665     v->vehstatus |= VS_TRAIN_SLOWING;
03666 
03667     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03668     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03669   } else {
03670     v->vehstatus &= ~VS_TRAIN_SLOWING;
03671   }
03672 
03673   if (!TrainCanLeaveTile(v)) return true;
03674 
03675   /* Determine the non-diagonal direction in which we will exit this tile */
03676   DiagDirection dir = TrainExitDir(v->direction, v->track);
03677   /* Calculate next tile */
03678   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03679 
03680   /* Determine the track status on the next tile */
03681   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03682   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03683 
03684   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03685   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03686 
03687   /* We are sure the train is not entering a depot, it is detected above */
03688 
03689   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03690   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03691   if (_settings_game.pf.forbid_90_deg) {
03692     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03693   }
03694 
03695   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03696   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03697     return TrainApproachingLineEnd(v, false, reverse);
03698   }
03699 
03700   /* approaching red signal */
03701   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03702 
03703   /* approaching a rail/road crossing? then make it red */
03704   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03705 
03706   return true;
03707 }
03708 
03709 
03710 static bool TrainLocoHandler(Train *v, bool mode)
03711 {
03712   /* train has crashed? */
03713   if (v->vehstatus & VS_CRASHED) {
03714     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03715   }
03716 
03717   if (v->force_proceed != TFP_NONE) {
03718     ClrBit(v->flags, VRF_TRAIN_STUCK);
03719     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03720   }
03721 
03722   /* train is broken down? */
03723   if (v->HandleBreakdown()) return true;
03724 
03725   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03726     ReverseTrainDirection(v);
03727   }
03728 
03729   /* exit if train is stopped */
03730   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03731 
03732   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03733   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03734     v->wait_counter = 0;
03735     v->cur_speed = 0;
03736     v->subspeed = 0;
03737     ClrBit(v->flags, VRF_LEAVING_STATION);
03738     ReverseTrainDirection(v);
03739     return true;
03740   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03741     /* Try to reserve a path when leaving the station as we
03742      * might not be marked as wanting a reservation, e.g.
03743      * when an overlength train gets turned around in a station. */
03744     DiagDirection dir = TrainExitDir(v->direction, v->track);
03745     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03746 
03747     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03748       TryPathReserve(v, true, true);
03749     }
03750     ClrBit(v->flags, VRF_LEAVING_STATION);
03751   }
03752 
03753   v->HandleLoading(mode);
03754 
03755   if (v->current_order.IsType(OT_LOADING)) return true;
03756 
03757   if (CheckTrainStayInDepot(v)) return true;
03758 
03759   if (!mode) v->ShowVisualEffect();
03760 
03761   /* We had no order but have an order now, do look ahead. */
03762   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03763     CheckNextTrainTile(v);
03764   }
03765 
03766   /* Handle stuck trains. */
03767   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03768     ++v->wait_counter;
03769 
03770     /* Should we try reversing this tick if still stuck? */
03771     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03772 
03773     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03774     if (!TryPathReserve(v)) {
03775       /* Still stuck. */
03776       if (turn_around) ReverseTrainDirection(v);
03777 
03778       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03779         /* Show message to player. */
03780         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03781           SetDParam(0, v->index);
03782           AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_STUCK, v->index);
03783         }
03784         v->wait_counter = 0;
03785       }
03786       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03787       if (v->force_proceed == TFP_NONE) return true;
03788       ClrBit(v->flags, VRF_TRAIN_STUCK);
03789       v->wait_counter = 0;
03790       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03791     }
03792   }
03793 
03794   if (v->current_order.IsType(OT_LEAVESTATION)) {
03795     v->current_order.Free();
03796     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03797     return true;
03798   }
03799 
03800   int j = v->UpdateSpeed();
03801 
03802   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03803   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03804     /* If we manually stopped, we're not force-proceeding anymore. */
03805     v->force_proceed = TFP_NONE;
03806     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03807   }
03808 
03809   int adv_spd = v->GetAdvanceDistance();
03810   if (j < adv_spd) {
03811     /* if the vehicle has speed 0, update the last_speed field. */
03812     if (v->cur_speed == 0) v->SetLastSpeed();
03813   } else {
03814     TrainCheckIfLineEnds(v);
03815     /* Loop until the train has finished moving. */
03816     for (;;) {
03817       j -= adv_spd;
03818       TrainController(v, NULL);
03819       /* Don't continue to move if the train crashed. */
03820       if (CheckTrainCollision(v)) break;
03821       /* Determine distance to next map position */
03822       adv_spd = v->GetAdvanceDistance();
03823 
03824       /* No more moving this tick */
03825       if (j < adv_spd || v->cur_speed == 0) break;
03826 
03827       OrderType order_type = v->current_order.GetType();
03828       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03829       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03830             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03831             IsTileType(v->tile, MP_STATION) &&
03832             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03833         ProcessOrders(v);
03834       }
03835     }
03836     v->SetLastSpeed();
03837   }
03838 
03839   for (Train *u = v; u != NULL; u = u->Next()) {
03840     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03841 
03842     u->UpdateViewport(false, false);
03843   }
03844 
03845   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03846 
03847   return true;
03848 }
03849 
03854 Money Train::GetRunningCost() const
03855 {
03856   Money cost = 0;
03857   const Train *v = this;
03858 
03859   do {
03860     const Engine *e = v->GetEngine();
03861     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03862 
03863     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03864     if (cost_factor == 0) continue;
03865 
03866     /* Halve running cost for multiheaded parts */
03867     if (v->IsMultiheaded()) cost_factor /= 2;
03868 
03869     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03870   } while ((v = v->GetNextVehicle()) != NULL);
03871 
03872   return cost;
03873 }
03874 
03879 bool Train::Tick()
03880 {
03881   this->tick_counter++;
03882 
03883   if (this->IsFrontEngine()) {
03884     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03885 
03886     this->current_order_time++;
03887 
03888     if (!TrainLocoHandler(this, false)) return false;
03889 
03890     return TrainLocoHandler(this, true);
03891   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03892     /* Delete flooded standalone wagon chain */
03893     if (++this->crash_anim_pos >= 4400) {
03894       delete this;
03895       return false;
03896     }
03897   }
03898 
03899   return true;
03900 }
03901 
03906 static void CheckIfTrainNeedsService(Train *v)
03907 {
03908   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03909   if (v->IsChainInDepot()) {
03910     VehicleServiceInDepot(v);
03911     return;
03912   }
03913 
03914   uint max_penalty;
03915   switch (_settings_game.pf.pathfinder_for_trains) {
03916     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03917     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03918     default: NOT_REACHED();
03919   }
03920 
03921   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03922   /* Only go to the depot if it is not too far out of our way. */
03923   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03924     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03925       /* If we were already heading for a depot but it has
03926        * suddenly moved farther away, we continue our normal
03927        * schedule? */
03928       v->current_order.MakeDummy();
03929       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03930     }
03931     return;
03932   }
03933 
03934   DepotID depot = GetDepotIndex(tfdd.tile);
03935 
03936   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03937       v->current_order.GetDestination() != depot &&
03938       !Chance16(3, 16)) {
03939     return;
03940   }
03941 
03942   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03943   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03944   v->dest_tile = tfdd.tile;
03945   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03946 }
03947 
03949 void Train::OnNewDay()
03950 {
03951   AgeVehicle(this);
03952 
03953   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03954 
03955   if (this->IsFrontEngine()) {
03956     CheckVehicleBreakdown(this);
03957 
03958     CheckIfTrainNeedsService(this);
03959 
03960     CheckOrders(this);
03961 
03962     /* update destination */
03963     if (this->current_order.IsType(OT_GOTO_STATION)) {
03964       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03965       if (tile != INVALID_TILE) this->dest_tile = tile;
03966     }
03967 
03968     if (this->running_ticks != 0) {
03969       /* running costs */
03970       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03971 
03972       this->profit_this_year -= cost.GetCost();
03973       this->running_ticks = 0;
03974 
03975       SubtractMoneyFromCompanyFract(this->owner, cost);
03976 
03977       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03978       SetWindowClassesDirty(WC_TRAINS_LIST);
03979     }
03980   }
03981 }
03982 
03987 Trackdir Train::GetVehicleTrackdir() const
03988 {
03989   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03990 
03991   if (this->track == TRACK_BIT_DEPOT) {
03992     /* We'll assume the train is facing outwards */
03993     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03994   }
03995 
03996   if (this->track == TRACK_BIT_WORMHOLE) {
03997     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03998     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03999   }
04000 
04001   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
04002 }