train_cmd.cpp

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00001 /* $Id: train_cmd.cpp 25991 2013-11-13 22:00:46Z rubidium $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "error.h"
00014 #include "articulated_vehicles.h"
00015 #include "command_func.h"
00016 #include "pathfinder/npf/npf_func.h"
00017 #include "pathfinder/yapf/yapf.hpp"
00018 #include "news_func.h"
00019 #include "company_func.h"
00020 #include "newgrf_sound.h"
00021 #include "newgrf_text.h"
00022 #include "strings_func.h"
00023 #include "viewport_func.h"
00024 #include "vehicle_func.h"
00025 #include "sound_func.h"
00026 #include "ai/ai.hpp"
00027 #include "game/game.hpp"
00028 #include "newgrf_station.h"
00029 #include "effectvehicle_func.h"
00030 #include "network/network.h"
00031 #include "spritecache.h"
00032 #include "core/random_func.hpp"
00033 #include "company_base.h"
00034 #include "newgrf.h"
00035 #include "order_backup.h"
00036 #include "zoom_func.h"
00037 
00038 #include "table/strings.h"
00039 #include "table/train_cmd.h"
00040 
00041 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00042 static bool TrainCheckIfLineEnds(Train *v, bool reverse = true);
00043 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // Also used in vehicle_sl.cpp.
00044 static TileIndex TrainApproachingCrossingTile(const Train *v);
00045 static void CheckIfTrainNeedsService(Train *v);
00046 static void CheckNextTrainTile(Train *v);
00047 
00048 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00049 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00050 
00051 
00059 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00060 {
00061   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00062 
00063   DiagDirection diagdir = DirToDiagDir(direction);
00064 
00065   /* Determine the diagonal direction in which we will exit this tile */
00066   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00067     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00068   }
00069 
00070   return diagdir;
00071 }
00072 
00073 
00079 byte FreightWagonMult(CargoID cargo)
00080 {
00081   if (!CargoSpec::Get(cargo)->is_freight) return 1;
00082   return _settings_game.vehicle.freight_trains;
00083 }
00084 
00086 void CheckTrainsLengths()
00087 {
00088   const Train *v;
00089   bool first = true;
00090 
00091   FOR_ALL_TRAINS(v) {
00092     if (v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00093       for (const Train *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00094         if (u->track != TRACK_BIT_DEPOT) {
00095           if ((w->track != TRACK_BIT_DEPOT &&
00096               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->CalcNextVehicleOffset()) ||
00097               (w->track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00098             SetDParam(0, v->index);
00099             SetDParam(1, v->owner);
00100             ShowErrorMessage(STR_BROKEN_VEHICLE_LENGTH, INVALID_STRING_ID, WL_CRITICAL);
00101 
00102             if (!_networking && first) {
00103               first = false;
00104               DoCommandP(0, PM_PAUSED_ERROR, 1, CMD_PAUSE);
00105             }
00106             /* Break so we warn only once for each train. */
00107             break;
00108           }
00109         }
00110       }
00111     }
00112   }
00113 }
00114 
00121 void Train::ConsistChanged(bool same_length)
00122 {
00123   uint16 max_speed = UINT16_MAX;
00124 
00125   assert(this->IsFrontEngine() || this->IsFreeWagon());
00126 
00127   const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
00128   EngineID first_engine = this->IsFrontEngine() ? this->engine_type : INVALID_ENGINE;
00129   this->gcache.cached_total_length = 0;
00130   this->compatible_railtypes = RAILTYPES_NONE;
00131 
00132   bool train_can_tilt = true;
00133 
00134   for (Train *u = this; u != NULL; u = u->Next()) {
00135     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00136 
00137     /* Check the this->first cache. */
00138     assert(u->First() == this);
00139 
00140     /* update the 'first engine' */
00141     u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;
00142     u->railtype = rvi_u->railtype;
00143 
00144     if (u->IsEngine()) first_engine = u->engine_type;
00145 
00146     /* Set user defined data to its default value */
00147     u->tcache.user_def_data = rvi_u->user_def_data;
00148     this->InvalidateNewGRFCache();
00149     u->InvalidateNewGRFCache();
00150   }
00151 
00152   for (Train *u = this; u != NULL; u = u->Next()) {
00153     /* Update user defined data (must be done before other properties) */
00154     u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
00155     this->InvalidateNewGRFCache();
00156     u->InvalidateNewGRFCache();
00157   }
00158 
00159   for (Train *u = this; u != NULL; u = u->Next()) {
00160     const Engine *e_u = u->GetEngine();
00161     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00162 
00163     if (!HasBit(e_u->info.misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00164 
00165     /* Cache wagon override sprite group. NULL is returned if there is none */
00166     u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);
00167 
00168     /* Reset colour map */
00169     u->colourmap = PAL_NONE;
00170 
00171     /* Update powered-wagon-status and visual effect */
00172     u->UpdateVisualEffect(true);
00173 
00174     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00175         UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
00176       /* wagon is powered */
00177       SetBit(u->flags, VRF_POWEREDWAGON); // cache 'powered' status
00178     } else {
00179       ClrBit(u->flags, VRF_POWEREDWAGON);
00180     }
00181 
00182     if (!u->IsArticulatedPart()) {
00183       /* Do not count powered wagons for the compatible railtypes, as wagons always
00184          have railtype normal */
00185       if (rvi_u->power > 0) {
00186         this->compatible_railtypes |= GetRailTypeInfo(u->railtype)->powered_railtypes;
00187       }
00188 
00189       /* Some electric engines can be allowed to run on normal rail. It happens to all
00190        * existing electric engines when elrails are disabled and then re-enabled */
00191       if (HasBit(u->flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00192         u->railtype = RAILTYPE_RAIL;
00193         u->compatible_railtypes |= RAILTYPES_RAIL;
00194       }
00195 
00196       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00197       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00198         uint16 speed = GetVehicleProperty(u, PROP_TRAIN_SPEED, rvi_u->max_speed);
00199         if (speed != 0) max_speed = min(speed, max_speed);
00200       }
00201     }
00202 
00203     u->cargo_cap = e_u->DetermineCapacity(u);
00204     u->vcache.cached_cargo_age_period = GetVehicleProperty(u, PROP_TRAIN_CARGO_AGE_PERIOD, e_u->info.cargo_age_period);
00205 
00206     /* check the vehicle length (callback) */
00207     uint16 veh_len = CALLBACK_FAILED;
00208     if (e_u->GetGRF() != NULL && e_u->GetGRF()->grf_version >= 8) {
00209       /* Use callback 36 */
00210       veh_len = GetVehicleProperty(u, PROP_TRAIN_SHORTEN_FACTOR, CALLBACK_FAILED);
00211 
00212       if (veh_len != CALLBACK_FAILED && veh_len >= VEHICLE_LENGTH) {
00213         ErrorUnknownCallbackResult(e_u->GetGRFID(), CBID_VEHICLE_LENGTH, veh_len);
00214       }
00215     } else if (HasBit(e_u->info.callback_mask, CBM_VEHICLE_LENGTH)) {
00216       /* Use callback 11 */
00217       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00218     }
00219     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00220     veh_len = VEHICLE_LENGTH - Clamp(veh_len, 0, VEHICLE_LENGTH - 1);
00221 
00222     /* verify length hasn't changed */
00223     if (same_length && veh_len != u->gcache.cached_veh_length) VehicleLengthChanged(u);
00224 
00225     /* update vehicle length? */
00226     if (!same_length) u->gcache.cached_veh_length = veh_len;
00227 
00228     this->gcache.cached_total_length += u->gcache.cached_veh_length;
00229     this->InvalidateNewGRFCache();
00230     u->InvalidateNewGRFCache();
00231   }
00232 
00233   /* store consist weight/max speed in cache */
00234   this->vcache.cached_max_speed = max_speed;
00235   this->tcache.cached_tilt = train_can_tilt;
00236   this->tcache.cached_max_curve_speed = this->GetCurveSpeedLimit();
00237 
00238   /* recalculate cached weights and power too (we do this *after* the rest, so it is known which wagons are powered and need extra weight added) */
00239   this->CargoChanged();
00240 
00241   if (this->IsFrontEngine()) {
00242     this->UpdateAcceleration();
00243     SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
00244     InvalidateWindowData(WC_VEHICLE_REFIT, this->index, VIWD_CONSIST_CHANGED);
00245     InvalidateWindowData(WC_VEHICLE_ORDERS, this->index, VIWD_CONSIST_CHANGED);
00246   }
00247 }
00248 
00259 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length)
00260 {
00261   const Station *st = Station::Get(station_id);
00262   *station_ahead  = st->GetPlatformLength(tile, DirToDiagDir(v->direction)) * TILE_SIZE;
00263   *station_length = st->GetPlatformLength(tile) * TILE_SIZE;
00264 
00265   /* Default to the middle of the station for stations stops that are not in
00266    * the order list like intermediate stations when non-stop is disabled */
00267   OrderStopLocation osl = OSL_PLATFORM_MIDDLE;
00268   if (v->gcache.cached_total_length >= *station_length) {
00269     /* The train is longer than the station, make it stop at the far end of the platform */
00270     osl = OSL_PLATFORM_FAR_END;
00271   } else if (v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetDestination() == station_id) {
00272     osl = v->current_order.GetStopLocation();
00273   }
00274 
00275   /* The stop location of the FRONT! of the train */
00276   int stop;
00277   switch (osl) {
00278     default: NOT_REACHED();
00279 
00280     case OSL_PLATFORM_NEAR_END:
00281       stop = v->gcache.cached_total_length;
00282       break;
00283 
00284     case OSL_PLATFORM_MIDDLE:
00285       stop = *station_length - (*station_length - v->gcache.cached_total_length) / 2;
00286       break;
00287 
00288     case OSL_PLATFORM_FAR_END:
00289       stop = *station_length;
00290       break;
00291   }
00292 
00293   /* Subtract half the front vehicle length of the train so we get the real
00294    * stop location of the train. */
00295   return stop - (v->gcache.cached_veh_length + 1) / 2;
00296 }
00297 
00298 
00303 int Train::GetCurveSpeedLimit() const
00304 {
00305   assert(this->First() == this);
00306 
00307   static const int absolute_max_speed = UINT16_MAX;
00308   int max_speed = absolute_max_speed;
00309 
00310   if (_settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) return max_speed;
00311 
00312   int curvecount[2] = {0, 0};
00313 
00314   /* first find the curve speed limit */
00315   int numcurve = 0;
00316   int sum = 0;
00317   int pos = 0;
00318   int lastpos = -1;
00319   for (const Vehicle *u = this; u->Next() != NULL; u = u->Next(), pos++) {
00320     Direction this_dir = u->direction;
00321     Direction next_dir = u->Next()->direction;
00322 
00323     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00324     if (dirdiff == DIRDIFF_SAME) continue;
00325 
00326     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00327     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00328     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00329       if (lastpos != -1) {
00330         numcurve++;
00331         sum += pos - lastpos;
00332         if (pos - lastpos == 1 && max_speed > 88) {
00333           max_speed = 88;
00334         }
00335       }
00336       lastpos = pos;
00337     }
00338 
00339     /* if we have a 90 degree turn, fix the speed limit to 60 */
00340     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00341       max_speed = 61;
00342     }
00343   }
00344 
00345   if (numcurve > 0 && max_speed > 88) {
00346     if (curvecount[0] == 1 && curvecount[1] == 1) {
00347       max_speed = absolute_max_speed;
00348     } else {
00349       sum /= numcurve;
00350       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00351     }
00352   }
00353 
00354   if (max_speed != absolute_max_speed) {
00355     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00356     const RailtypeInfo *rti = GetRailTypeInfo(this->railtype);
00357     max_speed += (max_speed / 2) * rti->curve_speed;
00358 
00359     if (this->tcache.cached_tilt) {
00360       /* Apply max_speed bonus of 20% for a tilting train */
00361       max_speed += max_speed / 5;
00362     }
00363   }
00364 
00365   return max_speed;
00366 }
00367 
00372 int Train::GetCurrentMaxSpeed() const
00373 {
00374   int max_speed = _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL ?
00375       this->gcache.cached_max_track_speed :
00376       this->tcache.cached_max_curve_speed;
00377 
00378   if (_settings_game.vehicle.train_acceleration_model == AM_REALISTIC && IsRailStationTile(this->tile)) {
00379     StationID sid = GetStationIndex(this->tile);
00380     if (this->current_order.ShouldStopAtStation(this, sid)) {
00381       int station_ahead;
00382       int station_length;
00383       int stop_at = GetTrainStopLocation(sid, this->tile, this, &station_ahead, &station_length);
00384 
00385       /* The distance to go is whatever is still ahead of the train minus the
00386        * distance from the train's stop location to the end of the platform */
00387       int distance_to_go = station_ahead / TILE_SIZE - (station_length - stop_at) / TILE_SIZE;
00388 
00389       if (distance_to_go > 0) {
00390         int st_max_speed = 120;
00391 
00392         int delta_v = this->cur_speed / (distance_to_go + 1);
00393         if (max_speed > (this->cur_speed - delta_v)) {
00394           st_max_speed = this->cur_speed - (delta_v / 10);
00395         }
00396 
00397         st_max_speed = max(st_max_speed, 25 * distance_to_go);
00398         max_speed = min(max_speed, st_max_speed);
00399       }
00400     }
00401   }
00402 
00403   for (const Train *u = this; u != NULL; u = u->Next()) {
00404     if (_settings_game.vehicle.train_acceleration_model == AM_REALISTIC && u->track == TRACK_BIT_DEPOT) {
00405       max_speed = min(max_speed, 61);
00406       break;
00407     }
00408 
00409     /* Vehicle is on the middle part of a bridge. */
00410     if (u->track == TRACK_BIT_WORMHOLE && !(u->vehstatus & VS_HIDDEN)) {
00411       max_speed = min(max_speed, GetBridgeSpec(GetBridgeType(u->tile))->speed);
00412     }
00413   }
00414 
00415   max_speed = min(max_speed, this->current_order.max_speed);
00416   return min(max_speed, this->gcache.cached_max_track_speed);
00417 }
00418 
00420 void Train::UpdateAcceleration()
00421 {
00422   assert(this->IsFrontEngine() || this->IsFreeWagon());
00423 
00424   uint power = this->gcache.cached_power;
00425   uint weight = this->gcache.cached_weight;
00426   assert(weight != 0);
00427   this->acceleration = Clamp(power / weight * 4, 1, 255);
00428 }
00429 
00435 int Train::GetDisplayImageWidth(Point *offset) const
00436 {
00437   int reference_width = TRAININFO_DEFAULT_VEHICLE_WIDTH;
00438   int vehicle_pitch = 0;
00439 
00440   const Engine *e = this->GetEngine();
00441   if (e->GetGRF() != NULL && is_custom_sprite(e->u.rail.image_index)) {
00442     reference_width = e->GetGRF()->traininfo_vehicle_width;
00443     vehicle_pitch = e->GetGRF()->traininfo_vehicle_pitch;
00444   }
00445 
00446   if (offset != NULL) {
00447     offset->x = reference_width / 2;
00448     offset->y = vehicle_pitch;
00449   }
00450   return this->gcache.cached_veh_length * reference_width / VEHICLE_LENGTH;
00451 }
00452 
00453 static SpriteID GetDefaultTrainSprite(uint8 spritenum, Direction direction)
00454 {
00455   return ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00456 }
00457 
00464 SpriteID Train::GetImage(Direction direction, EngineImageType image_type) const
00465 {
00466   uint8 spritenum = this->spritenum;
00467   SpriteID sprite;
00468 
00469   if (HasBit(this->flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00470 
00471   if (is_custom_sprite(spritenum)) {
00472     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)), image_type);
00473     if (sprite != 0) return sprite;
00474 
00475     spritenum = this->GetEngine()->original_image_index;
00476   }
00477 
00478   sprite = GetDefaultTrainSprite(spritenum, direction);
00479 
00480   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00481 
00482   return sprite;
00483 }
00484 
00485 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y, EngineImageType image_type)
00486 {
00487   const Engine *e = Engine::Get(engine);
00488   Direction dir = rear_head ? DIR_E : DIR_W;
00489   uint8 spritenum = e->u.rail.image_index;
00490 
00491   if (is_custom_sprite(spritenum)) {
00492     SpriteID sprite = GetCustomVehicleIcon(engine, dir, image_type);
00493     if (sprite != 0) {
00494       if (e->GetGRF() != NULL) {
00495         y += e->GetGRF()->traininfo_vehicle_pitch;
00496       }
00497       return sprite;
00498     }
00499 
00500     spritenum = Engine::Get(engine)->original_image_index;
00501   }
00502 
00503   if (rear_head) spritenum++;
00504 
00505   return GetDefaultTrainSprite(spritenum, DIR_W);
00506 }
00507 
00508 void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
00509 {
00510   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00511     int yf = y;
00512     int yr = y;
00513 
00514     SpriteID spritef = GetRailIcon(engine, false, yf, image_type);
00515     SpriteID spriter = GetRailIcon(engine, true, yr, image_type);
00516     const Sprite *real_spritef = GetSprite(spritef, ST_NORMAL);
00517     const Sprite *real_spriter = GetSprite(spriter, ST_NORMAL);
00518 
00519     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);
00520 
00521     DrawSprite(spritef, pal, preferred_x - 14, yf);
00522     DrawSprite(spriter, pal, preferred_x + 15, yr);
00523   } else {
00524     SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00525     const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00526     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));
00527     DrawSprite(sprite, pal, preferred_x, y);
00528   }
00529 }
00530 
00540 void GetTrainSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type)
00541 {
00542   int y = 0;
00543 
00544   SpriteID sprite = GetRailIcon(engine, false, y, image_type);
00545   const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
00546 
00547   width  = UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI);
00548   height = UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI);
00549   xoffs  = UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI);
00550   yoffs  = UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI);
00551 
00552   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00553     sprite = GetRailIcon(engine, true, y, image_type);
00554     real_sprite = GetSprite(sprite, ST_NORMAL);
00555 
00556     /* Calculate values relative to an imaginary center between the two sprites. */
00557     width = TRAININFO_DEFAULT_VEHICLE_WIDTH + UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) + UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI) - xoffs;
00558     height = max<uint>(height, UnScaleByZoom(real_sprite->height, ZOOM_LVL_GUI));
00559     xoffs  = xoffs - TRAININFO_DEFAULT_VEHICLE_WIDTH / 2;
00560     yoffs  = min(yoffs, UnScaleByZoom(real_sprite->y_offs, ZOOM_LVL_GUI));
00561   }
00562 }
00563 
00572 static CommandCost CmdBuildRailWagon(TileIndex tile, DoCommandFlag flags, const Engine *e, Vehicle **ret)
00573 {
00574   const RailVehicleInfo *rvi = &e->u.rail;
00575 
00576   /* Check that the wagon can drive on the track in question */
00577   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00578 
00579   if (flags & DC_EXEC) {
00580     Train *v = new Train();
00581     *ret = v;
00582     v->spritenum = rvi->image_index;
00583 
00584     v->engine_type = e->index;
00585     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00586 
00587     DiagDirection dir = GetRailDepotDirection(tile);
00588 
00589     v->direction = DiagDirToDir(dir);
00590     v->tile = tile;
00591 
00592     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00593     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00594 
00595     v->x_pos = x;
00596     v->y_pos = y;
00597     v->z_pos = GetSlopePixelZ(x, y);
00598     v->owner = _current_company;
00599     v->track = TRACK_BIT_DEPOT;
00600     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00601 
00602     v->SetWagon();
00603 
00604     v->SetFreeWagon();
00605     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00606 
00607     v->cargo_type = e->GetDefaultCargoType();
00608     v->cargo_cap = rvi->capacity;
00609 
00610     v->railtype = rvi->railtype;
00611 
00612     v->build_year = _cur_year;
00613     v->cur_image = SPR_IMG_QUERY;
00614     v->random_bits = VehicleRandomBits();
00615 
00616     v->group_id = DEFAULT_GROUP;
00617 
00618     AddArticulatedParts(v);
00619 
00620     _new_vehicle_id = v->index;
00621 
00622     VehicleUpdatePosition(v);
00623     v->First()->ConsistChanged(false);
00624     UpdateTrainGroupID(v->First());
00625 
00626     CheckConsistencyOfArticulatedVehicle(v);
00627 
00628     /* Try to connect the vehicle to one of free chains of wagons. */
00629     Train *w;
00630     FOR_ALL_TRAINS(w) {
00631       if (w->tile == tile &&              
00632           w->IsFreeWagon() &&             
00633           w->engine_type == e->index &&   
00634           w->First() != v &&              
00635           !(w->vehstatus & VS_CRASHED)) { 
00636         DoCommand(0, v->index | 1 << 20, w->Last()->index, DC_EXEC, CMD_MOVE_RAIL_VEHICLE);
00637         break;
00638       }
00639     }
00640   }
00641 
00642   return CommandCost();
00643 }
00644 
00646 static void NormalizeTrainVehInDepot(const Train *u)
00647 {
00648   const Train *v;
00649   FOR_ALL_TRAINS(v) {
00650     if (v->IsFreeWagon() && v->tile == u->tile &&
00651         v->track == TRACK_BIT_DEPOT) {
00652       if (DoCommand(0, v->index | 1 << 20, u->index, DC_EXEC,
00653           CMD_MOVE_RAIL_VEHICLE).Failed())
00654         break;
00655     }
00656   }
00657 }
00658 
00659 static void AddRearEngineToMultiheadedTrain(Train *v)
00660 {
00661   Train *u = new Train();
00662   v->value >>= 1;
00663   u->value = v->value;
00664   u->direction = v->direction;
00665   u->owner = v->owner;
00666   u->tile = v->tile;
00667   u->x_pos = v->x_pos;
00668   u->y_pos = v->y_pos;
00669   u->z_pos = v->z_pos;
00670   u->track = TRACK_BIT_DEPOT;
00671   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00672   u->spritenum = v->spritenum + 1;
00673   u->cargo_type = v->cargo_type;
00674   u->cargo_subtype = v->cargo_subtype;
00675   u->cargo_cap = v->cargo_cap;
00676   u->railtype = v->railtype;
00677   u->engine_type = v->engine_type;
00678   u->build_year = v->build_year;
00679   u->cur_image = SPR_IMG_QUERY;
00680   u->random_bits = VehicleRandomBits();
00681   v->SetMultiheaded();
00682   u->SetMultiheaded();
00683   v->SetNext(u);
00684   VehicleUpdatePosition(u);
00685 
00686   /* Now we need to link the front and rear engines together */
00687   v->other_multiheaded_part = u;
00688   u->other_multiheaded_part = v;
00689 }
00690 
00700 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
00701 {
00702   const RailVehicleInfo *rvi = &e->u.rail;
00703 
00704   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(tile, flags, e, ret);
00705 
00706   /* Check if depot and new engine uses the same kind of tracks *
00707    * We need to see if the engine got power on the tile to avoid electric engines in non-electric depots */
00708   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00709 
00710   if (flags & DC_EXEC) {
00711     DiagDirection dir = GetRailDepotDirection(tile);
00712     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00713     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00714 
00715     Train *v = new Train();
00716     *ret = v;
00717     v->direction = DiagDirToDir(dir);
00718     v->tile = tile;
00719     v->owner = _current_company;
00720     v->x_pos = x;
00721     v->y_pos = y;
00722     v->z_pos = GetSlopePixelZ(x, y);
00723     v->track = TRACK_BIT_DEPOT;
00724     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00725     v->spritenum = rvi->image_index;
00726     v->cargo_type = e->GetDefaultCargoType();
00727     v->cargo_cap = rvi->capacity;
00728     v->last_station_visited = INVALID_STATION;
00729 
00730     v->engine_type = e->index;
00731     v->gcache.first_engine = INVALID_ENGINE; // needs to be set before first callback
00732 
00733     v->reliability = e->reliability;
00734     v->reliability_spd_dec = e->reliability_spd_dec;
00735     v->max_age = e->GetLifeLengthInDays();
00736 
00737     v->railtype = rvi->railtype;
00738     _new_vehicle_id = v->index;
00739 
00740     v->SetServiceInterval(Company::Get(_current_company)->settings.vehicle.servint_trains);
00741     v->date_of_last_service = _date;
00742     v->build_year = _cur_year;
00743     v->cur_image = SPR_IMG_QUERY;
00744     v->random_bits = VehicleRandomBits();
00745 
00746     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00747     v->SetServiceIntervalIsPercent(Company::Get(_current_company)->settings.vehicle.servint_ispercent);
00748 
00749     v->group_id = DEFAULT_GROUP;
00750 
00751     v->SetFrontEngine();
00752     v->SetEngine();
00753 
00754     VehicleUpdatePosition(v);
00755 
00756     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00757       AddRearEngineToMultiheadedTrain(v);
00758     } else {
00759       AddArticulatedParts(v);
00760     }
00761 
00762     v->ConsistChanged(false);
00763     UpdateTrainGroupID(v);
00764 
00765     if (!HasBit(data, 0) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00766       NormalizeTrainVehInDepot(v);
00767     }
00768 
00769     CheckConsistencyOfArticulatedVehicle(v);
00770   }
00771 
00772   return CommandCost();
00773 }
00774 
00775 static Train *FindGoodVehiclePos(const Train *src)
00776 {
00777   EngineID eng = src->engine_type;
00778   TileIndex tile = src->tile;
00779 
00780   Train *dst;
00781   FOR_ALL_TRAINS(dst) {
00782     if (dst->IsFreeWagon() && dst->tile == tile && !(dst->vehstatus & VS_CRASHED)) {
00783       /* check so all vehicles in the line have the same engine. */
00784       Train *t = dst;
00785       while (t->engine_type == eng) {
00786         t = t->Next();
00787         if (t == NULL) return dst;
00788       }
00789     }
00790   }
00791 
00792   return NULL;
00793 }
00794 
00796 typedef SmallVector<Train *, 16> TrainList;
00797 
00803 static void MakeTrainBackup(TrainList &list, Train *t)
00804 {
00805   for (; t != NULL; t = t->Next()) *list.Append() = t;
00806 }
00807 
00812 static void RestoreTrainBackup(TrainList &list)
00813 {
00814   /* No train, nothing to do. */
00815   if (list.Length() == 0) return;
00816 
00817   Train *prev = NULL;
00818   /* Iterate over the list and rebuild it. */
00819   for (Train **iter = list.Begin(); iter != list.End(); iter++) {
00820     Train *t = *iter;
00821     if (prev != NULL) {
00822       prev->SetNext(t);
00823     } else if (t->Previous() != NULL) {
00824       /* Make sure the head of the train is always the first in the chain. */
00825       t->Previous()->SetNext(NULL);
00826     }
00827     prev = t;
00828   }
00829 }
00830 
00836 static void RemoveFromConsist(Train *part, bool chain = false)
00837 {
00838   Train *tail = chain ? part->Last() : part->GetLastEnginePart();
00839 
00840   /* Unlink at the front, but make it point to the next
00841    * vehicle after the to be remove part. */
00842   if (part->Previous() != NULL) part->Previous()->SetNext(tail->Next());
00843 
00844   /* Unlink at the back */
00845   tail->SetNext(NULL);
00846 }
00847 
00853 static void InsertInConsist(Train *dst, Train *chain)
00854 {
00855   /* We do not want to add something in the middle of an articulated part. */
00856   assert(dst->Next() == NULL || !dst->Next()->IsArticulatedPart());
00857 
00858   chain->Last()->SetNext(dst->Next());
00859   dst->SetNext(chain);
00860 }
00861 
00867 static void NormaliseDualHeads(Train *t)
00868 {
00869   for (; t != NULL; t = t->GetNextVehicle()) {
00870     if (!t->IsMultiheaded() || !t->IsEngine()) continue;
00871 
00872     /* Make sure that there are no free cars before next engine */
00873     Train *u;
00874     for (u = t; u->Next() != NULL && !u->Next()->IsEngine(); u = u->Next()) {}
00875 
00876     if (u == t->other_multiheaded_part) continue;
00877 
00878     /* Remove the part from the 'wrong' train */
00879     RemoveFromConsist(t->other_multiheaded_part);
00880     /* And add it to the 'right' train */
00881     InsertInConsist(u, t->other_multiheaded_part);
00882   }
00883 }
00884 
00889 static void NormaliseSubtypes(Train *chain)
00890 {
00891   /* Nothing to do */
00892   if (chain == NULL) return;
00893 
00894   /* We must be the first in the chain. */
00895   assert(chain->Previous() == NULL);
00896 
00897   /* Set the appropriate bits for the first in the chain. */
00898   if (chain->IsWagon()) {
00899     chain->SetFreeWagon();
00900   } else {
00901     assert(chain->IsEngine());
00902     chain->SetFrontEngine();
00903   }
00904 
00905   /* Now clear the bits for the rest of the chain */
00906   for (Train *t = chain->Next(); t != NULL; t = t->Next()) {
00907     t->ClearFreeWagon();
00908     t->ClearFrontEngine();
00909   }
00910 }
00911 
00921 static CommandCost CheckNewTrain(Train *original_dst, Train *dst, Train *original_src, Train *src)
00922 {
00923   /* Just add 'new' engines and subtract the original ones.
00924    * If that's less than or equal to 0 we can be sure we did
00925    * not add any engines (read: trains) along the way. */
00926   if ((src          != NULL && src->IsEngine()          ? 1 : 0) +
00927       (dst          != NULL && dst->IsEngine()          ? 1 : 0) -
00928       (original_src != NULL && original_src->IsEngine() ? 1 : 0) -
00929       (original_dst != NULL && original_dst->IsEngine() ? 1 : 0) <= 0) {
00930     return CommandCost();
00931   }
00932 
00933   /* Get a free unit number and check whether it's within the bounds.
00934    * There will always be a maximum of one new train. */
00935   if (GetFreeUnitNumber(VEH_TRAIN) <= _settings_game.vehicle.max_trains) return CommandCost();
00936 
00937   return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
00938 }
00939 
00945 static CommandCost CheckTrainAttachment(Train *t)
00946 {
00947   /* No multi-part train, no need to check. */
00948   if (t == NULL || t->Next() == NULL || !t->IsEngine()) return CommandCost();
00949 
00950   /* The maximum length for a train. For each part we decrease this by one
00951    * and if the result is negative the train is simply too long. */
00952   int allowed_len = _settings_game.vehicle.max_train_length * TILE_SIZE - t->gcache.cached_veh_length;
00953 
00954   Train *head = t;
00955   Train *prev = t;
00956 
00957   /* Break the prev -> t link so it always holds within the loop. */
00958   t = t->Next();
00959   prev->SetNext(NULL);
00960 
00961   /* Make sure the cache is cleared. */
00962   head->InvalidateNewGRFCache();
00963 
00964   while (t != NULL) {
00965     allowed_len -= t->gcache.cached_veh_length;
00966 
00967     Train *next = t->Next();
00968 
00969     /* Unlink the to-be-added piece; it is already unlinked from the previous
00970      * part due to the fact that the prev -> t link is broken. */
00971     t->SetNext(NULL);
00972 
00973     /* Don't check callback for articulated or rear dual headed parts */
00974     if (!t->IsArticulatedPart() && !t->IsRearDualheaded()) {
00975       /* Back up and clear the first_engine data to avoid using wagon override group */
00976       EngineID first_engine = t->gcache.first_engine;
00977       t->gcache.first_engine = INVALID_ENGINE;
00978 
00979       /* We don't want the cache to interfere. head's cache is cleared before
00980        * the loop and after each callback does not need to be cleared here. */
00981       t->InvalidateNewGRFCache();
00982 
00983       uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, head->engine_type, t, head);
00984 
00985       /* Restore original first_engine data */
00986       t->gcache.first_engine = first_engine;
00987 
00988       /* We do not want to remember any cached variables from the test run */
00989       t->InvalidateNewGRFCache();
00990       head->InvalidateNewGRFCache();
00991 
00992       if (callback != CALLBACK_FAILED) {
00993         /* A failing callback means everything is okay */
00994         StringID error = STR_NULL;
00995 
00996         if (head->GetGRF()->grf_version < 8) {
00997           if (callback == 0xFD) error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
00998           if (callback  < 0xFD) error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
00999           if (callback >= 0x100) ErrorUnknownCallbackResult(head->GetGRFID(), CBID_TRAIN_ALLOW_WAGON_ATTACH, callback);
01000         } else {
01001           if (callback < 0x400) {
01002             error = GetGRFStringID(head->GetGRFID(), 0xD000 + callback);
01003           } else {
01004             switch (callback) {
01005               case 0x400: // allow if railtypes match (always the case for OpenTTD)
01006               case 0x401: // allow
01007                 break;
01008 
01009               default:    // unknown reason -> disallow
01010               case 0x402: // disallow attaching
01011                 error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
01012                 break;
01013             }
01014           }
01015         }
01016 
01017         if (error != STR_NULL) return_cmd_error(error);
01018       }
01019     }
01020 
01021     /* And link it to the new part. */
01022     prev->SetNext(t);
01023     prev = t;
01024     t = next;
01025   }
01026 
01027   if (allowed_len < 0) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
01028   return CommandCost();
01029 }
01030 
01041 static CommandCost ValidateTrains(Train *original_dst, Train *dst, Train *original_src, Train *src, bool check_limit)
01042 {
01043   /* Check whether we may actually construct the trains. */
01044   CommandCost ret = CheckTrainAttachment(src);
01045   if (ret.Failed()) return ret;
01046   ret = CheckTrainAttachment(dst);
01047   if (ret.Failed()) return ret;
01048 
01049   /* Check whether we need to build a new train. */
01050   return check_limit ? CheckNewTrain(original_dst, dst, original_src, src) : CommandCost();
01051 }
01052 
01061 static void ArrangeTrains(Train **dst_head, Train *dst, Train **src_head, Train *src, bool move_chain)
01062 {
01063   /* First determine the front of the two resulting trains */
01064   if (*src_head == *dst_head) {
01065     /* If we aren't moving part(s) to a new train, we are just moving the
01066      * front back and there is not destination head. */
01067     *dst_head = NULL;
01068   } else if (*dst_head == NULL) {
01069     /* If we are moving to a new train the head of the move train would become
01070      * the head of the new vehicle. */
01071     *dst_head = src;
01072   }
01073 
01074   if (src == *src_head) {
01075     /* If we are moving the front of a train then we are, in effect, creating
01076      * a new head for the train. Point to that. Unless we are moving the whole
01077      * train in which case there is not 'source' train anymore.
01078      * In case we are a multiheaded part we want the complete thing to come
01079      * with us, so src->GetNextUnit(), however... when we are e.g. a wagon
01080      * that is followed by a rear multihead we do not want to include that. */
01081     *src_head = move_chain ? NULL :
01082         (src->IsMultiheaded() ? src->GetNextUnit() : src->GetNextVehicle());
01083   }
01084 
01085   /* Now it's just simply removing the part that we are going to move from the
01086    * source train and *if* the destination is a not a new train add the chain
01087    * at the destination location. */
01088   RemoveFromConsist(src, move_chain);
01089   if (*dst_head != src) InsertInConsist(dst, src);
01090 
01091   /* Now normalise the dual heads, that is move the dual heads around in such
01092    * a way that the head and rear of a dual head are in the same train */
01093   NormaliseDualHeads(*src_head);
01094   NormaliseDualHeads(*dst_head);
01095 }
01096 
01102 static void NormaliseTrainHead(Train *head)
01103 {
01104   /* Not much to do! */
01105   if (head == NULL) return;
01106 
01107   /* Tell the 'world' the train changed. */
01108   head->ConsistChanged(false);
01109   UpdateTrainGroupID(head);
01110 
01111   /* Not a front engine, i.e. a free wagon chain. No need to do more. */
01112   if (!head->IsFrontEngine()) return;
01113 
01114   /* Update the refit button and window */
01115   InvalidateWindowData(WC_VEHICLE_REFIT, head->index, VIWD_CONSIST_CHANGED);
01116   SetWindowWidgetDirty(WC_VEHICLE_VIEW, head->index, WID_VV_REFIT);
01117 
01118   /* If we don't have a unit number yet, set one. */
01119   if (head->unitnumber != 0) return;
01120   head->unitnumber = GetFreeUnitNumber(VEH_TRAIN);
01121 }
01122 
01135 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01136 {
01137   VehicleID s = GB(p1, 0, 20);
01138   VehicleID d = GB(p2, 0, 20);
01139   bool move_chain = HasBit(p1, 20);
01140 
01141   Train *src = Train::GetIfValid(s);
01142   if (src == NULL) return CMD_ERROR;
01143 
01144   CommandCost ret = CheckOwnership(src->owner);
01145   if (ret.Failed()) return ret;
01146 
01147   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01148   if (src->vehstatus & VS_CRASHED) return CMD_ERROR;
01149 
01150   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01151   Train *dst;
01152   if (d == INVALID_VEHICLE) {
01153     dst = src->IsEngine() ? NULL : FindGoodVehiclePos(src);
01154   } else {
01155     dst = Train::GetIfValid(d);
01156     if (dst == NULL) return CMD_ERROR;
01157 
01158     CommandCost ret = CheckOwnership(dst->owner);
01159     if (ret.Failed()) return ret;
01160 
01161     /* Do not allow appending to crashed vehicles, too */
01162     if (dst->vehstatus & VS_CRASHED) return CMD_ERROR;
01163   }
01164 
01165   /* if an articulated part is being handled, deal with its parent vehicle */
01166   src = src->GetFirstEnginePart();
01167   if (dst != NULL) {
01168     dst = dst->GetFirstEnginePart();
01169   }
01170 
01171   /* don't move the same vehicle.. */
01172   if (src == dst) return CommandCost();
01173 
01174   /* locate the head of the two chains */
01175   Train *src_head = src->First();
01176   Train *dst_head;
01177   if (dst != NULL) {
01178     dst_head = dst->First();
01179     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01180     /* Now deal with articulated part of destination wagon */
01181     dst = dst->GetLastEnginePart();
01182   } else {
01183     dst_head = NULL;
01184   }
01185 
01186   if (src->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01187 
01188   /* When moving all wagons, we can't have the same src_head and dst_head */
01189   if (move_chain && src_head == dst_head) return CommandCost();
01190 
01191   /* When moving a multiheaded part to be place after itself, bail out. */
01192   if (!move_chain && dst != NULL && dst->IsRearDualheaded() && src == dst->other_multiheaded_part) return CommandCost();
01193 
01194   /* Check if all vehicles in the source train are stopped inside a depot. */
01195   if (!src_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01196 
01197   /* Check if all vehicles in the destination train are stopped inside a depot. */
01198   if (dst_head != NULL && !dst_head->IsStoppedInDepot()) return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01199 
01200   /* First make a backup of the order of the trains. That way we can do
01201    * whatever we want with the order and later on easily revert. */
01202   TrainList original_src;
01203   TrainList original_dst;
01204 
01205   MakeTrainBackup(original_src, src_head);
01206   MakeTrainBackup(original_dst, dst_head);
01207 
01208   /* Also make backup of the original heads as ArrangeTrains can change them.
01209    * For the destination head we do not care if it is the same as the source
01210    * head because in that case it's just a copy. */
01211   Train *original_src_head = src_head;
01212   Train *original_dst_head = (dst_head == src_head ? NULL : dst_head);
01213 
01214   /* We want this information from before the rearrangement, but execute this after the validation. */
01215   bool original_src_head_front_engine = original_src_head != NULL && original_src_head->IsFrontEngine();
01216   bool original_dst_head_front_engine = original_dst_head != NULL && original_dst_head->IsFrontEngine();
01217 
01218   /* (Re)arrange the trains in the wanted arrangement. */
01219   ArrangeTrains(&dst_head, dst, &src_head, src, move_chain);
01220 
01221   if ((flags & DC_AUTOREPLACE) == 0) {
01222     /* If the autoreplace flag is set we do not need to test for the validity
01223      * because we are going to revert the train to its original state. As we
01224      * assume the original state was correct autoreplace can skip this. */
01225     CommandCost ret = ValidateTrains(original_dst_head, dst_head, original_src_head, src_head, true);
01226     if (ret.Failed()) {
01227       /* Restore the train we had. */
01228       RestoreTrainBackup(original_src);
01229       RestoreTrainBackup(original_dst);
01230       return ret;
01231     }
01232   }
01233 
01234   /* do it? */
01235   if (flags & DC_EXEC) {
01236     /* Remove old heads from the statistics */
01237     if (original_src_head_front_engine) GroupStatistics::CountVehicle(original_src_head, -1);
01238     if (original_dst_head_front_engine) GroupStatistics::CountVehicle(original_dst_head, -1);
01239 
01240     /* First normalise the sub types of the chains. */
01241     NormaliseSubtypes(src_head);
01242     NormaliseSubtypes(dst_head);
01243 
01244     /* There are 14 different cases:
01245      *  1) front engine gets moved to a new train, it stays a front engine.
01246      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01247      *     b) the 'next' part is an engine that becomes a front engine.
01248      *     c) there is no 'next' part, nothing else happens
01249      *  2) front engine gets moved to another train, it is not a front engine anymore
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      *  3) front engine gets moved to later in the current 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      *  4) free wagon gets moved
01257      *     a) the 'next' part is a wagon that becomes a free wagon chain.
01258      *     b) the 'next' part is an engine that becomes a front engine.
01259      *     c) there is no 'next' part, nothing else happens
01260      *  5) non front engine gets moved and becomes a new train, nothing else happens
01261      *  6) non front engine gets moved within a train / to another train, nothing hapens
01262      *  7) wagon gets moved, nothing happens
01263      */
01264     if (src == original_src_head && src->IsEngine() && !src->IsFrontEngine()) {
01265       /* Cases #2 and #3: the front engine gets trashed. */
01266       DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01267       DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01268       DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01269       DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01270       DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01271       SetWindowDirty(WC_COMPANY, _current_company);
01272 
01273       /* Delete orders, group stuff and the unit number as we're not the
01274        * front of any vehicle anymore. */
01275       DeleteVehicleOrders(src);
01276       RemoveVehicleFromGroup(src);
01277       src->unitnumber = 0;
01278     }
01279 
01280     /* We weren't a front engine but are becoming one. So
01281      * we should be put in the default group. */
01282     if (original_src_head != src && dst_head == src) {
01283       SetTrainGroupID(src, DEFAULT_GROUP);
01284       SetWindowDirty(WC_COMPANY, _current_company);
01285     }
01286 
01287     /* Add new heads to statistics */
01288     if (src_head != NULL && src_head->IsFrontEngine()) GroupStatistics::CountVehicle(src_head, 1);
01289     if (dst_head != NULL && dst_head->IsFrontEngine()) GroupStatistics::CountVehicle(dst_head, 1);
01290 
01291     /* Handle 'new engine' part of cases #1b, #2b, #3b, #4b and #5 in NormaliseTrainHead. */
01292     NormaliseTrainHead(src_head);
01293     NormaliseTrainHead(dst_head);
01294 
01295     if ((flags & DC_NO_CARGO_CAP_CHECK) == 0) {
01296       CheckCargoCapacity(src_head);
01297       CheckCargoCapacity(dst_head);
01298     }
01299 
01300     /* We are undoubtedly changing something in the depot and train list. */
01301     InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01302     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01303   } else {
01304     /* We don't want to execute what we're just tried. */
01305     RestoreTrainBackup(original_src);
01306     RestoreTrainBackup(original_dst);
01307   }
01308 
01309   return CommandCost();
01310 }
01311 
01323 CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint32 user)
01324 {
01325   /* Check if we deleted a vehicle window */
01326   Window *w = NULL;
01327 
01328   /* Sell a chain of vehicles or not? */
01329   bool sell_chain = HasBit(data, 0);
01330 
01331   Train *v = Train::From(t)->GetFirstEnginePart();
01332   Train *first = v->First();
01333 
01334   if (v->IsRearDualheaded()) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
01335 
01336   /* First make a backup of the order of the train. That way we can do
01337    * whatever we want with the order and later on easily revert. */
01338   TrainList original;
01339   MakeTrainBackup(original, first);
01340 
01341   /* We need to keep track of the new head and the head of what we're going to sell. */
01342   Train *new_head = first;
01343   Train *sell_head = NULL;
01344 
01345   /* Split the train in the wanted way. */
01346   ArrangeTrains(&sell_head, NULL, &new_head, v, sell_chain);
01347 
01348   /* We don't need to validate the second train; it's going to be sold. */
01349   CommandCost ret = ValidateTrains(NULL, NULL, first, new_head, (flags & DC_AUTOREPLACE) == 0);
01350   if (ret.Failed()) {
01351     /* Restore the train we had. */
01352     RestoreTrainBackup(original);
01353     return ret;
01354   }
01355 
01356   CommandCost cost(EXPENSES_NEW_VEHICLES);
01357   for (Train *t = sell_head; t != NULL; t = t->Next()) cost.AddCost(-t->value);
01358 
01359   if (first->orders.list == NULL && !OrderList::CanAllocateItem()) {
01360     return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
01361   }
01362 
01363   /* do it? */
01364   if (flags & DC_EXEC) {
01365     /* First normalise the sub types of the chain. */
01366     NormaliseSubtypes(new_head);
01367 
01368     if (v == first && v->IsEngine() && !sell_chain && new_head != NULL && new_head->IsFrontEngine()) {
01369       /* We are selling the front engine. In this case we want to
01370        * 'give' the order, unit number and such to the new head. */
01371       new_head->orders.list = first->orders.list;
01372       new_head->AddToShared(first);
01373       DeleteVehicleOrders(first);
01374 
01375       /* Copy other important data from the front engine */
01376       new_head->CopyVehicleConfigAndStatistics(first);
01377       GroupStatistics::CountVehicle(new_head, 1); // after copying over the profit
01378 
01379       /* If we deleted a window then open a new one for the 'new' train */
01380       if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_head);
01381     } else if (v->IsPrimaryVehicle() && data & (MAKE_ORDER_BACKUP_FLAG >> 20)) {
01382       OrderBackup::Backup(v, user);
01383     }
01384 
01385     /* We need to update the information about the train. */
01386     NormaliseTrainHead(new_head);
01387 
01388     /* We are undoubtedly changing something in the depot and train list. */
01389     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01390     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01391 
01392     /* Actually delete the sold 'goods' */
01393     delete sell_head;
01394   } else {
01395     /* We don't want to execute what we're just tried. */
01396     RestoreTrainBackup(original);
01397   }
01398 
01399   return cost;
01400 }
01401 
01402 void Train::UpdateDeltaXY(Direction direction)
01403 {
01404   /* Set common defaults. */
01405   this->x_offs    = -1;
01406   this->y_offs    = -1;
01407   this->x_extent  =  3;
01408   this->y_extent  =  3;
01409   this->z_extent  =  6;
01410   this->x_bb_offs =  0;
01411   this->y_bb_offs =  0;
01412 
01413   if (!IsDiagonalDirection(direction)) {
01414     static const int _sign_table[] =
01415     {
01416       // x, y
01417       -1, -1, // DIR_N
01418       -1,  1, // DIR_E
01419        1,  1, // DIR_S
01420        1, -1, // DIR_W
01421     };
01422 
01423     int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;
01424 
01425     /* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
01426     this->x_offs -= half_shorten * _sign_table[direction];
01427     this->y_offs -= half_shorten * _sign_table[direction + 1];
01428     this->x_extent += this->x_bb_offs = half_shorten * _sign_table[direction];
01429     this->y_extent += this->y_bb_offs = half_shorten * _sign_table[direction + 1];
01430   } else {
01431     switch (direction) {
01432         /* Shorten southern corner of the bounding box according the vehicle length
01433          * and center the bounding box on the vehicle. */
01434       case DIR_NE:
01435         this->x_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01436         this->x_extent  = this->gcache.cached_veh_length - 1;
01437         this->x_bb_offs = -1;
01438         break;
01439 
01440       case DIR_NW:
01441         this->y_offs    = 1 - (this->gcache.cached_veh_length + 1) / 2;
01442         this->y_extent  = this->gcache.cached_veh_length - 1;
01443         this->y_bb_offs = -1;
01444         break;
01445 
01446         /* Move northern corner of the bounding box down according to vehicle length
01447          * and center the bounding box on the vehicle. */
01448       case DIR_SW:
01449         this->x_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01450         this->x_extent  = VEHICLE_LENGTH - 1;
01451         this->x_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01452         break;
01453 
01454       case DIR_SE:
01455         this->y_offs    = 1 + (this->gcache.cached_veh_length + 1) / 2 - VEHICLE_LENGTH;
01456         this->y_extent  = VEHICLE_LENGTH - 1;
01457         this->y_bb_offs = VEHICLE_LENGTH - this->gcache.cached_veh_length - 1;
01458         break;
01459 
01460       default:
01461         NOT_REACHED();
01462     }
01463   }
01464 }
01465 
01470 static void MarkTrainAsStuck(Train *v)
01471 {
01472   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) {
01473     /* It is the first time the problem occurred, set the "train stuck" flag. */
01474     SetBit(v->flags, VRF_TRAIN_STUCK);
01475 
01476     v->wait_counter = 0;
01477 
01478     /* Stop train */
01479     v->cur_speed = 0;
01480     v->subspeed = 0;
01481     v->SetLastSpeed();
01482 
01483     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01484   }
01485 }
01486 
01494 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01495 {
01496   uint16 flag1 = *swap_flag1;
01497   uint16 flag2 = *swap_flag2;
01498 
01499   /* Clear the flags */
01500   ClrBit(*swap_flag1, GVF_GOINGUP_BIT);
01501   ClrBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01502   ClrBit(*swap_flag2, GVF_GOINGUP_BIT);
01503   ClrBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01504 
01505   /* Reverse the rail-flags (if needed) */
01506   if (HasBit(flag1, GVF_GOINGUP_BIT)) {
01507     SetBit(*swap_flag2, GVF_GOINGDOWN_BIT);
01508   } else if (HasBit(flag1, GVF_GOINGDOWN_BIT)) {
01509     SetBit(*swap_flag2, GVF_GOINGUP_BIT);
01510   }
01511   if (HasBit(flag2, GVF_GOINGUP_BIT)) {
01512     SetBit(*swap_flag1, GVF_GOINGDOWN_BIT);
01513   } else if (HasBit(flag2, GVF_GOINGDOWN_BIT)) {
01514     SetBit(*swap_flag1, GVF_GOINGUP_BIT);
01515   }
01516 }
01517 
01522 static void UpdateStatusAfterSwap(Train *v)
01523 {
01524   /* Reverse the direction. */
01525   if (v->track != TRACK_BIT_DEPOT) v->direction = ReverseDir(v->direction);
01526 
01527   /* Call the proper EnterTile function unless we are in a wormhole. */
01528   if (v->track != TRACK_BIT_WORMHOLE) {
01529     VehicleEnterTile(v, v->tile, v->x_pos, v->y_pos);
01530   } else {
01531     /* VehicleEnter_TunnelBridge() sets TRACK_BIT_WORMHOLE when the vehicle
01532      * is on the last bit of the bridge head (frame == TILE_SIZE - 1).
01533      * If we were swapped with such a vehicle, we have set TRACK_BIT_WORMHOLE,
01534      * when we shouldn't have. Check if this is the case. */
01535     TileIndex vt = TileVirtXY(v->x_pos, v->y_pos);
01536     if (IsTileType(vt, MP_TUNNELBRIDGE)) {
01537       VehicleEnterTile(v, vt, v->x_pos, v->y_pos);
01538       if (v->track != TRACK_BIT_WORMHOLE && IsBridgeTile(v->tile)) {
01539         /* We have just left the wormhole, possibly set the
01540          * "goingdown" bit. UpdateInclination() can be used
01541          * because we are at the border of the tile. */
01542         VehicleUpdatePosition(v);
01543         v->UpdateInclination(true, true);
01544         return;
01545       }
01546     }
01547   }
01548 
01549   VehicleUpdatePosition(v);
01550   v->UpdateViewport(true, true);
01551 }
01552 
01559 void ReverseTrainSwapVeh(Train *v, int l, int r)
01560 {
01561   Train *a, *b;
01562 
01563   /* locate vehicles to swap */
01564   for (a = v; l != 0; l--) a = a->Next();
01565   for (b = v; r != 0; r--) b = b->Next();
01566 
01567   if (a != b) {
01568     /* swap the hidden bits */
01569     {
01570       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus & VS_HIDDEN);
01571       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus & VS_HIDDEN);
01572       a->vehstatus = tmp;
01573     }
01574 
01575     Swap(a->track, b->track);
01576     Swap(a->direction, b->direction);
01577     Swap(a->x_pos, b->x_pos);
01578     Swap(a->y_pos, b->y_pos);
01579     Swap(a->tile,  b->tile);
01580     Swap(a->z_pos, b->z_pos);
01581 
01582     SwapTrainFlags(&a->gv_flags, &b->gv_flags);
01583 
01584     UpdateStatusAfterSwap(a);
01585     UpdateStatusAfterSwap(b);
01586   } else {
01587     /* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
01588      * This is a little bit redundant way, a->gv_flags will
01589      * be (re)set twice, but it reduces code duplication */
01590     SwapTrainFlags(&a->gv_flags, &a->gv_flags);
01591     UpdateStatusAfterSwap(a);
01592   }
01593 }
01594 
01595 
01601 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01602 {
01603   return (v->type == VEH_TRAIN) ? v : NULL;
01604 }
01605 
01606 
01613 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01614 {
01615   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
01616 
01617   Train *t = Train::From(v);
01618   if (!t->IsFrontEngine()) return NULL;
01619 
01620   TileIndex tile = *(TileIndex *)data;
01621 
01622   if (TrainApproachingCrossingTile(t) != tile) return NULL;
01623 
01624   return t;
01625 }
01626 
01627 
01634 static bool TrainApproachingCrossing(TileIndex tile)
01635 {
01636   assert(IsLevelCrossingTile(tile));
01637 
01638   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01639   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01640 
01641   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01642 
01643   dir = ReverseDiagDir(dir);
01644   tile_from = tile + TileOffsByDiagDir(dir);
01645 
01646   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01647 }
01648 
01649 
01656 void UpdateLevelCrossing(TileIndex tile, bool sound)
01657 {
01658   assert(IsLevelCrossingTile(tile));
01659 
01660   /* train on crossing || train approaching crossing || reserved */
01661   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || HasCrossingReservation(tile);
01662 
01663   if (new_state != IsCrossingBarred(tile)) {
01664     if (new_state && sound) {
01665       if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01666     }
01667     SetCrossingBarred(tile, new_state);
01668     MarkTileDirtyByTile(tile);
01669   }
01670 }
01671 
01672 
01678 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01679 {
01680   if (!IsCrossingBarred(tile)) {
01681     BarCrossing(tile);
01682     if (_settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01683     MarkTileDirtyByTile(tile);
01684   }
01685 }
01686 
01687 
01693 static void AdvanceWagonsBeforeSwap(Train *v)
01694 {
01695   Train *base = v;
01696   Train *first = base; // first vehicle to move
01697   Train *last = v->Last(); // last vehicle to move
01698   uint length = CountVehiclesInChain(v);
01699 
01700   while (length > 2) {
01701     last = last->Previous();
01702     first = first->Next();
01703 
01704     int differential = base->CalcNextVehicleOffset() - last->CalcNextVehicleOffset();
01705 
01706     /* do not update images now
01707      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01708     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01709 
01710     base = first; // == base->Next()
01711     length -= 2;
01712   }
01713 }
01714 
01715 
01721 static void AdvanceWagonsAfterSwap(Train *v)
01722 {
01723   /* first of all, fix the situation when the train was entering a depot */
01724   Train *dep = v; // last vehicle in front of just left depot
01725   while (dep->Next() != NULL && (dep->track == TRACK_BIT_DEPOT || dep->Next()->track != TRACK_BIT_DEPOT)) {
01726     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01727   }
01728 
01729   Train *leave = dep->Next(); // first vehicle in a depot we are leaving now
01730 
01731   if (leave != NULL) {
01732     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01733     int d = TicksToLeaveDepot(dep);
01734 
01735     if (d <= 0) {
01736       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01737       leave->track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01738       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01739     }
01740   } else {
01741     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01742   }
01743 
01744   Train *base = v;
01745   Train *first = base; // first vehicle to move
01746   Train *last = v->Last(); // last vehicle to move
01747   uint length = CountVehiclesInChain(v);
01748 
01749   /* We have to make sure all wagons that leave a depot because of train reversing are moved correctly
01750    * they have already correct spacing, so we have to make sure they are moved how they should */
01751   bool nomove = (dep == NULL); // If there is no vehicle leaving a depot, limit the number of wagons moved immediately.
01752 
01753   while (length > 2) {
01754     /* we reached vehicle (originally) in front of a depot, stop now
01755      * (we would move wagons that are already moved with new wagon length). */
01756     if (base == dep) break;
01757 
01758     /* the last wagon was that one leaving a depot, so do not move it anymore */
01759     if (last == dep) nomove = true;
01760 
01761     last = last->Previous();
01762     first = first->Next();
01763 
01764     int differential = last->CalcNextVehicleOffset() - base->CalcNextVehicleOffset();
01765 
01766     /* do not update images now */
01767     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01768 
01769     base = first; // == base->Next()
01770     length -= 2;
01771   }
01772 }
01773 
01778 void ReverseTrainDirection(Train *v)
01779 {
01780   if (IsRailDepotTile(v->tile)) {
01781     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01782   }
01783 
01784   /* Clear path reservation in front if train is not stuck. */
01785   if (!HasBit(v->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01786 
01787   /* Check if we were approaching a rail/road-crossing */
01788   TileIndex crossing = TrainApproachingCrossingTile(v);
01789 
01790   /* count number of vehicles */
01791   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01792 
01793   AdvanceWagonsBeforeSwap(v);
01794 
01795   /* swap start<>end, start+1<>end-1, ... */
01796   int l = 0;
01797   do {
01798     ReverseTrainSwapVeh(v, l++, r--);
01799   } while (l <= r);
01800 
01801   AdvanceWagonsAfterSwap(v);
01802 
01803   if (IsRailDepotTile(v->tile)) {
01804     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01805   }
01806 
01807   ToggleBit(v->flags, VRF_TOGGLE_REVERSE);
01808 
01809   ClrBit(v->flags, VRF_REVERSING);
01810 
01811   /* recalculate cached data */
01812   v->ConsistChanged(true);
01813 
01814   /* update all images */
01815   for (Train *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01816 
01817   /* update crossing we were approaching */
01818   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01819 
01820   /* maybe we are approaching crossing now, after reversal */
01821   crossing = TrainApproachingCrossingTile(v);
01822   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01823 
01824   /* If we are inside a depot after reversing, don't bother with path reserving. */
01825   if (v->track == TRACK_BIT_DEPOT) {
01826     /* Can't be stuck here as inside a depot is always a safe tile. */
01827     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
01828     ClrBit(v->flags, VRF_TRAIN_STUCK);
01829     return;
01830   }
01831 
01832   /* TrainExitDir does not always produce the desired dir for depots and
01833    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01834   DiagDirection dir = TrainExitDir(v->direction, v->track);
01835   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01836 
01837   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01838     /* If we are currently on a tile with conventional signals, we can't treat the
01839      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01840     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01841       HasSignalOnTrackdir(v->tile, v->GetVehicleTrackdir()) &&
01842       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->track))));
01843 
01844     /* If we are on a depot tile facing outwards, do not treat the current tile as safe. */
01845     if (IsRailDepotTile(v->tile) && TrackdirToExitdir(v->GetVehicleTrackdir()) == GetRailDepotDirection(v->tile)) first_tile_okay = false;
01846 
01847     if (IsRailStationTile(v->tile)) SetRailStationPlatformReservation(v->tile, TrackdirToExitdir(v->GetVehicleTrackdir()), true);
01848     if (TryPathReserve(v, false, first_tile_okay)) {
01849       /* Do a look-ahead now in case our current tile was already a safe tile. */
01850       CheckNextTrainTile(v);
01851     } else if (v->current_order.GetType() != OT_LOADING) {
01852       /* Do not wait for a way out when we're still loading */
01853       MarkTrainAsStuck(v);
01854     }
01855   } else if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
01856     /* A train not inside a PBS block can't be stuck. */
01857     ClrBit(v->flags, VRF_TRAIN_STUCK);
01858     v->wait_counter = 0;
01859   }
01860 }
01861 
01871 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01872 {
01873   Train *v = Train::GetIfValid(p1);
01874   if (v == NULL) return CMD_ERROR;
01875 
01876   CommandCost ret = CheckOwnership(v->owner);
01877   if (ret.Failed()) return ret;
01878 
01879   if (p2 != 0) {
01880     /* turn a single unit around */
01881 
01882     if (v->IsMultiheaded() || HasBit(EngInfo(v->engine_type)->callback_mask, CBM_VEHICLE_ARTIC_ENGINE)) {
01883       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01884     }
01885     if (!HasBit(EngInfo(v->engine_type)->misc_flags, EF_RAIL_FLIPS)) return CMD_ERROR;
01886 
01887     Train *front = v->First();
01888     /* make sure the vehicle is stopped in the depot */
01889     if (!front->IsStoppedInDepot()) {
01890       return_cmd_error(STR_ERROR_TRAINS_CAN_ONLY_BE_ALTERED_INSIDE_A_DEPOT);
01891     }
01892 
01893     if (flags & DC_EXEC) {
01894       ToggleBit(v->flags, VRF_REVERSE_DIRECTION);
01895 
01896       front->ConsistChanged(false);
01897       SetWindowDirty(WC_VEHICLE_DEPOT, front->tile);
01898       SetWindowDirty(WC_VEHICLE_DETAILS, front->index);
01899       SetWindowDirty(WC_VEHICLE_VIEW, front->index);
01900       SetWindowClassesDirty(WC_TRAINS_LIST);
01901     }
01902   } else {
01903     /* turn the whole train around */
01904     if ((v->vehstatus & VS_CRASHED) || v->breakdown_ctr != 0) return CMD_ERROR;
01905 
01906     if (flags & DC_EXEC) {
01907       /* Properly leave the station if we are loading and won't be loading anymore */
01908       if (v->current_order.IsType(OT_LOADING)) {
01909         const Vehicle *last = v;
01910         while (last->Next() != NULL) last = last->Next();
01911 
01912         /* not a station || different station --> leave the station */
01913         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01914           v->LeaveStation();
01915         }
01916       }
01917 
01918       /* We cancel any 'skip signal at dangers' here */
01919       v->force_proceed = TFP_NONE;
01920       SetWindowDirty(WC_VEHICLE_VIEW, v->index);
01921 
01922       if (_settings_game.vehicle.train_acceleration_model != AM_ORIGINAL && v->cur_speed != 0) {
01923         ToggleBit(v->flags, VRF_REVERSING);
01924       } else {
01925         v->cur_speed = 0;
01926         v->SetLastSpeed();
01927         HideFillingPercent(&v->fill_percent_te_id);
01928         ReverseTrainDirection(v);
01929       }
01930     }
01931   }
01932   return CommandCost();
01933 }
01934 
01944 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01945 {
01946   Train *t = Train::GetIfValid(p1);
01947   if (t == NULL) return CMD_ERROR;
01948 
01949   if (!t->IsPrimaryVehicle()) return CMD_ERROR;
01950 
01951   CommandCost ret = CheckOwnership(t->owner);
01952   if (ret.Failed()) return ret;
01953 
01954 
01955   if (flags & DC_EXEC) {
01956     /* If we are forced to proceed, cancel that order.
01957      * If we are marked stuck we would want to force the train
01958      * to proceed to the next signal. In the other cases we
01959      * would like to pass the signal at danger and run till the
01960      * next signal we encounter. */
01961     t->force_proceed = t->force_proceed == TFP_SIGNAL ? TFP_NONE : HasBit(t->flags, VRF_TRAIN_STUCK) || t->IsChainInDepot() ? TFP_STUCK : TFP_SIGNAL;
01962     SetWindowDirty(WC_VEHICLE_VIEW, t->index);
01963   }
01964 
01965   return CommandCost();
01966 }
01967 
01975 static FindDepotData FindClosestTrainDepot(Train *v, int max_distance)
01976 {
01977   assert(!(v->vehstatus & VS_CRASHED));
01978 
01979   if (IsRailDepotTile(v->tile)) return FindDepotData(v->tile, 0);
01980 
01981   PBSTileInfo origin = FollowTrainReservation(v);
01982   if (IsRailDepotTile(origin.tile)) return FindDepotData(origin.tile, 0);
01983 
01984   switch (_settings_game.pf.pathfinder_for_trains) {
01985     case VPF_NPF: return NPFTrainFindNearestDepot(v, max_distance);
01986     case VPF_YAPF: return YapfTrainFindNearestDepot(v, max_distance);
01987 
01988     default: NOT_REACHED();
01989   }
01990 }
01991 
01999 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
02000 {
02001   FindDepotData tfdd = FindClosestTrainDepot(this, 0);
02002   if (tfdd.best_length == UINT_MAX) return false;
02003 
02004   if (location    != NULL) *location    = tfdd.tile;
02005   if (destination != NULL) *destination = GetDepotIndex(tfdd.tile);
02006   if (reverse     != NULL) *reverse     = tfdd.reverse;
02007 
02008   return true;
02009 }
02010 
02012 void Train::PlayLeaveStationSound() const
02013 {
02014   static const SoundFx sfx[] = {
02015     SND_04_TRAIN,
02016     SND_0A_TRAIN_HORN,
02017     SND_0A_TRAIN_HORN,
02018     SND_47_MAGLEV_2,
02019     SND_41_MAGLEV
02020   };
02021 
02022   if (PlayVehicleSound(this, VSE_START)) return;
02023 
02024   EngineID engtype = this->engine_type;
02025   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02026 }
02027 
02032 static void CheckNextTrainTile(Train *v)
02033 {
02034   /* Don't do any look-ahead if path_backoff_interval is 255. */
02035   if (_settings_game.pf.path_backoff_interval == 255) return;
02036 
02037   /* Exit if we are inside a depot. */
02038   if (v->track == TRACK_BIT_DEPOT) return;
02039 
02040   switch (v->current_order.GetType()) {
02041     /* Exit if we reached our destination depot. */
02042     case OT_GOTO_DEPOT:
02043       if (v->tile == v->dest_tile) return;
02044       break;
02045 
02046     case OT_GOTO_WAYPOINT:
02047       /* If we reached our waypoint, make sure we see that. */
02048       if (IsRailWaypointTile(v->tile) && GetStationIndex(v->tile) == v->current_order.GetDestination()) ProcessOrders(v);
02049       break;
02050 
02051     case OT_NOTHING:
02052     case OT_LEAVESTATION:
02053     case OT_LOADING:
02054       /* Exit if the current order doesn't have a destination, but the train has orders. */
02055       if (v->GetNumOrders() > 0) return;
02056       break;
02057 
02058     default:
02059       break;
02060   }
02061   /* Exit if we are on a station tile and are going to stop. */
02062   if (IsRailStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02063 
02064   Trackdir td = v->GetVehicleTrackdir();
02065 
02066   /* On a tile with a red non-pbs signal, don't look ahead. */
02067   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02068       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02069       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02070 
02071   CFollowTrackRail ft(v);
02072   if (!ft.Follow(v->tile, td)) return;
02073 
02074   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02075     /* Next tile is not reserved. */
02076     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02077       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02078         /* If the next tile is a PBS signal, try to make a reservation. */
02079         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02080         if (_settings_game.pf.forbid_90_deg) {
02081           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02082         }
02083         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02084       }
02085     }
02086   }
02087 }
02088 
02094 static bool CheckTrainStayInDepot(Train *v)
02095 {
02096   /* bail out if not all wagons are in the same depot or not in a depot at all */
02097   for (const Train *u = v; u != NULL; u = u->Next()) {
02098     if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02099   }
02100 
02101   /* if the train got no power, then keep it in the depot */
02102   if (v->gcache.cached_power == 0) {
02103     v->vehstatus |= VS_STOPPED;
02104     SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
02105     return true;
02106   }
02107 
02108   SigSegState seg_state;
02109 
02110   if (v->force_proceed == TFP_NONE) {
02111     /* force proceed was not pressed */
02112     if (++v->wait_counter < 37) {
02113       SetWindowClassesDirty(WC_TRAINS_LIST);
02114       return true;
02115     }
02116 
02117     v->wait_counter = 0;
02118 
02119     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02120     if (seg_state == SIGSEG_FULL || HasDepotReservation(v->tile)) {
02121       /* Full and no PBS signal in block or depot reserved, can't exit. */
02122       SetWindowClassesDirty(WC_TRAINS_LIST);
02123       return true;
02124     }
02125   } else {
02126     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02127   }
02128 
02129   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02130   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02131     /* We need to have a reservation for this to work. */
02132     if (HasDepotReservation(v->tile)) return true;
02133     SetDepotReservation(v->tile, true);
02134     VehicleEnterDepot(v);
02135     return true;
02136   }
02137 
02138   /* Only leave when we can reserve a path to our destination. */
02139   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->force_proceed == TFP_NONE) {
02140     /* No path and no force proceed. */
02141     SetWindowClassesDirty(WC_TRAINS_LIST);
02142     MarkTrainAsStuck(v);
02143     return true;
02144   }
02145 
02146   SetDepotReservation(v->tile, true);
02147   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02148 
02149   VehicleServiceInDepot(v);
02150   SetWindowClassesDirty(WC_TRAINS_LIST);
02151   v->PlayLeaveStationSound();
02152 
02153   v->track = TRACK_BIT_X;
02154   if (v->direction & 2) v->track = TRACK_BIT_Y;
02155 
02156   v->vehstatus &= ~VS_HIDDEN;
02157   v->cur_speed = 0;
02158 
02159   v->UpdateViewport(true, true);
02160   VehicleUpdatePosition(v);
02161   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02162   v->UpdateAcceleration();
02163   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02164 
02165   return false;
02166 }
02167 
02174 static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_dir)
02175 {
02176   DiagDirection dir = TrackdirToExitdir(track_dir);
02177 
02178   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02179     /* Are we just leaving a tunnel/bridge? */
02180     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02181       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02182 
02183       if (TunnelBridgeIsFree(tile, end, v).Succeeded()) {
02184         /* Free the reservation only if no other train is on the tiles. */
02185         SetTunnelBridgeReservation(tile, false);
02186         SetTunnelBridgeReservation(end, false);
02187 
02188         if (_settings_client.gui.show_track_reservation) {
02189           MarkTileDirtyByTile(tile);
02190           MarkTileDirtyByTile(end);
02191         }
02192       }
02193     }
02194   } else if (IsRailStationTile(tile)) {
02195     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02196     /* If the new tile is not a further tile of the same station, we
02197      * clear the reservation for the whole platform. */
02198     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02199       SetRailStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02200     }
02201   } else {
02202     /* Any other tile */
02203     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02204   }
02205 }
02206 
02213 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
02214 {
02215   assert(v->IsFrontEngine());
02216 
02217   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02218   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
02219   bool      free_tile = tile != v->tile || !(IsRailStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02220   StationID station_id = IsRailStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02221 
02222   /* Can't be holding a reservation if we enter a depot. */
02223   if (IsRailDepotTile(tile) && TrackdirToExitdir(td) != GetRailDepotDirection(tile)) return;
02224   if (v->track == TRACK_BIT_DEPOT) {
02225     /* Front engine is in a depot. We enter if some part is not in the depot. */
02226     for (const Train *u = v; u != NULL; u = u->Next()) {
02227       if (u->track != TRACK_BIT_DEPOT || u->tile != v->tile) return;
02228     }
02229   }
02230   /* Don't free reservation if it's not ours. */
02231   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02232 
02233   CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);
02234   while (ft.Follow(tile, td)) {
02235     tile = ft.m_new_tile;
02236     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02237     td = RemoveFirstTrackdir(&bits);
02238     assert(bits == TRACKDIR_BIT_NONE);
02239 
02240     if (!IsValidTrackdir(td)) break;
02241 
02242     if (IsTileType(tile, MP_RAILWAY)) {
02243       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02244         /* Conventional signal along trackdir: remove reservation and stop. */
02245         UnreserveRailTrack(tile, TrackdirToTrack(td));
02246         break;
02247       }
02248       if (HasPbsSignalOnTrackdir(tile, td)) {
02249         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02250           /* Red PBS signal? Can't be our reservation, would be green then. */
02251           break;
02252         } else {
02253           /* Turn the signal back to red. */
02254           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02255           MarkTileDirtyByTile(tile);
02256         }
02257       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02258         break;
02259       }
02260     }
02261 
02262     /* Don't free first station/bridge/tunnel if we are on it. */
02263     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);
02264 
02265     free_tile = true;
02266   }
02267 }
02268 
02269 static const byte _initial_tile_subcoord[6][4][3] = {
02270 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02271 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02272 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02273 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02274 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02275 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02276 };
02277 
02290 static Track DoTrainPathfind(const Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool &path_found, bool do_track_reservation, PBSTileInfo *dest)
02291 {
02292   switch (_settings_game.pf.pathfinder_for_trains) {
02293     case VPF_NPF: return NPFTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02294     case VPF_YAPF: return YapfTrainChooseTrack(v, tile, enterdir, tracks, path_found, do_track_reservation, dest);
02295 
02296     default: NOT_REACHED();
02297   }
02298 }
02299 
02305 static PBSTileInfo ExtendTrainReservation(const Train *v, TrackBits *new_tracks, DiagDirection *enterdir)
02306 {
02307   PBSTileInfo origin = FollowTrainReservation(v);
02308 
02309   CFollowTrackRail ft(v);
02310 
02311   TileIndex tile = origin.tile;
02312   Trackdir  cur_td = origin.trackdir;
02313   while (ft.Follow(tile, cur_td)) {
02314     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02315       /* Possible signal tile. */
02316       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02317     }
02318 
02319     if (_settings_game.pf.forbid_90_deg) {
02320       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02321       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02322     }
02323 
02324     /* Station, depot or waypoint are a possible target. */
02325     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02326     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02327       /* Choice found or possible target encountered.
02328        * On finding a possible target, we need to stop and let the pathfinder handle the
02329        * remaining path. This is because we don't know if this target is in one of our
02330        * orders, so we might cause pathfinding to fail later on if we find a choice.
02331        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02332        * a wrong path not leading to our next destination. */
02333       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02334 
02335       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02336        * actually starts its search at the first unreserved tile. */
02337       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02338 
02339       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02340       if (new_tracks != NULL) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02341       if (enterdir != NULL) *enterdir = ft.m_exitdir;
02342       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02343     }
02344 
02345     tile = ft.m_new_tile;
02346     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02347 
02348     if (IsSafeWaitingPosition(v, tile, cur_td, true, _settings_game.pf.forbid_90_deg)) {
02349       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, _settings_game.pf.forbid_90_deg);
02350       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02351       /* Safe position is all good, path valid and okay. */
02352       return PBSTileInfo(tile, cur_td, true);
02353     }
02354 
02355     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02356   }
02357 
02358   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02359     /* End of line, path valid and okay. */
02360     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02361   }
02362 
02363   /* Sorry, can't reserve path, back out. */
02364   tile = origin.tile;
02365   cur_td = origin.trackdir;
02366   TileIndex stopped = ft.m_old_tile;
02367   Trackdir  stopped_td = ft.m_old_td;
02368   while (tile != stopped || cur_td != stopped_td) {
02369     if (!ft.Follow(tile, cur_td)) break;
02370 
02371     if (_settings_game.pf.forbid_90_deg) {
02372       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02373       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02374     }
02375     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02376 
02377     tile = ft.m_new_tile;
02378     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02379 
02380     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02381   }
02382 
02383   /* Path invalid. */
02384   return PBSTileInfo();
02385 }
02386 
02397 static bool TryReserveSafeTrack(const Train *v, TileIndex tile, Trackdir td, bool override_tailtype)
02398 {
02399   switch (_settings_game.pf.pathfinder_for_trains) {
02400     case VPF_NPF: return NPFTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02401     case VPF_YAPF: return YapfTrainFindNearestSafeTile(v, tile, td, override_tailtype);
02402 
02403     default: NOT_REACHED();
02404   }
02405 }
02406 
02408 class VehicleOrderSaver {
02409 private:
02410   Train          *v;
02411   Order          old_order;
02412   TileIndex      old_dest_tile;
02413   StationID      old_last_station_visited;
02414   VehicleOrderID index;
02415   bool           suppress_implicit_orders;
02416 
02417 public:
02418   VehicleOrderSaver(Train *_v) :
02419     v(_v),
02420     old_order(_v->current_order),
02421     old_dest_tile(_v->dest_tile),
02422     old_last_station_visited(_v->last_station_visited),
02423     index(_v->cur_real_order_index),
02424     suppress_implicit_orders(HasBit(_v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS))
02425   {
02426   }
02427 
02428   ~VehicleOrderSaver()
02429   {
02430     this->v->current_order = this->old_order;
02431     this->v->dest_tile = this->old_dest_tile;
02432     this->v->last_station_visited = this->old_last_station_visited;
02433     SB(this->v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS, 1, suppress_implicit_orders ? 1: 0);
02434   }
02435 
02441   bool SwitchToNextOrder(bool skip_first)
02442   {
02443     if (this->v->GetNumOrders() == 0) return false;
02444 
02445     if (skip_first) ++this->index;
02446 
02447     int depth = 0;
02448 
02449     do {
02450       /* Wrap around. */
02451       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02452 
02453       Order *order = this->v->GetOrder(this->index);
02454       assert(order != NULL);
02455 
02456       switch (order->GetType()) {
02457         case OT_GOTO_DEPOT:
02458           /* Skip service in depot orders when the train doesn't need service. */
02459           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02460         case OT_GOTO_STATION:
02461         case OT_GOTO_WAYPOINT:
02462           this->v->current_order = *order;
02463           return UpdateOrderDest(this->v, order, 0, true);
02464         case OT_CONDITIONAL: {
02465           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02466           if (next != INVALID_VEH_ORDER_ID) {
02467             depth++;
02468             this->index = next;
02469             /* Don't increment next, so no break here. */
02470             continue;
02471           }
02472           break;
02473         }
02474         default:
02475           break;
02476       }
02477       /* Don't increment inside the while because otherwise conditional
02478        * orders can lead to an infinite loop. */
02479       ++this->index;
02480       depth++;
02481     } while (this->index != this->v->cur_real_order_index && depth < this->v->GetNumOrders());
02482 
02483     return false;
02484   }
02485 };
02486 
02487 /* choose a track */
02488 static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02489 {
02490   Track best_track = INVALID_TRACK;
02491   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02492   bool changed_signal = false;
02493 
02494   assert((tracks & ~TRACK_BIT_MASK) == 0);
02495 
02496   if (got_reservation != NULL) *got_reservation = false;
02497 
02498   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02499   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02500   /* Do we have a suitable reserved track? */
02501   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02502 
02503   /* Quick return in case only one possible track is available */
02504   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02505     Track track = FindFirstTrack(tracks);
02506     /* We need to check for signals only here, as a junction tile can't have signals. */
02507     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02508       do_track_reservation = true;
02509       changed_signal = true;
02510       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02511     } else if (!do_track_reservation) {
02512       return track;
02513     }
02514     best_track = track;
02515   }
02516 
02517   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02518   DiagDirection dest_enterdir = enterdir;
02519   if (do_track_reservation) {
02520     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02521     if (res_dest.tile == INVALID_TILE) {
02522       /* Reservation failed? */
02523       if (mark_stuck) MarkTrainAsStuck(v);
02524       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02525       return FindFirstTrack(tracks);
02526     }
02527     if (res_dest.okay) {
02528       /* Got a valid reservation that ends at a safe target, quick exit. */
02529       if (got_reservation != NULL) *got_reservation = true;
02530       if (changed_signal) MarkTileDirtyByTile(tile);
02531       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02532       return best_track;
02533     }
02534 
02535     /* Check if the train needs service here, so it has a chance to always find a depot.
02536      * Also check if the current order is a service order so we don't reserve a path to
02537      * the destination but instead to the next one if service isn't needed. */
02538     CheckIfTrainNeedsService(v);
02539     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02540   }
02541 
02542   /* Save the current train order. The destructor will restore the old order on function exit. */
02543   VehicleOrderSaver orders(v);
02544 
02545   /* If the current tile is the destination of the current order and
02546    * a reservation was requested, advance to the next order.
02547    * Don't advance on a depot order as depots are always safe end points
02548    * for a path and no look-ahead is necessary. This also avoids a
02549    * problem with depot orders not part of the order list when the
02550    * order list itself is empty. */
02551   if (v->current_order.IsType(OT_LEAVESTATION)) {
02552     orders.SwitchToNextOrder(false);
02553   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02554       v->current_order.IsType(OT_GOTO_STATION) ?
02555       IsRailStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02556       v->tile == v->dest_tile))) {
02557     orders.SwitchToNextOrder(true);
02558   }
02559 
02560   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02561     /* Pathfinders are able to tell that route was only 'guessed'. */
02562     bool      path_found = true;
02563     TileIndex new_tile = res_dest.tile;
02564 
02565     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, path_found, do_track_reservation, &res_dest);
02566     if (new_tile == tile) best_track = next_track;
02567     v->HandlePathfindingResult(path_found);
02568   }
02569 
02570   /* No track reservation requested -> finished. */
02571   if (!do_track_reservation) return best_track;
02572 
02573   /* A path was found, but could not be reserved. */
02574   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02575     if (mark_stuck) MarkTrainAsStuck(v);
02576     FreeTrainTrackReservation(v);
02577     return best_track;
02578   }
02579 
02580   /* No possible reservation target found, we are probably lost. */
02581   if (res_dest.tile == INVALID_TILE) {
02582     /* Try to find any safe destination. */
02583     PBSTileInfo origin = FollowTrainReservation(v);
02584     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02585       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02586       best_track = FindFirstTrack(res);
02587       TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02588       if (got_reservation != NULL) *got_reservation = true;
02589       if (changed_signal) MarkTileDirtyByTile(tile);
02590     } else {
02591       FreeTrainTrackReservation(v);
02592       if (mark_stuck) MarkTrainAsStuck(v);
02593     }
02594     return best_track;
02595   }
02596 
02597   if (got_reservation != NULL) *got_reservation = true;
02598 
02599   /* Reservation target found and free, check if it is safe. */
02600   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02601     /* Extend reservation until we have found a safe position. */
02602     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02603     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02604     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02605     if (_settings_game.pf.forbid_90_deg) {
02606       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02607     }
02608 
02609     /* Get next order with destination. */
02610     if (orders.SwitchToNextOrder(true)) {
02611       PBSTileInfo cur_dest;
02612       bool path_found;
02613       DoTrainPathfind(v, next_tile, exitdir, reachable, path_found, true, &cur_dest);
02614       if (cur_dest.tile != INVALID_TILE) {
02615         res_dest = cur_dest;
02616         if (res_dest.okay) continue;
02617         /* Path found, but could not be reserved. */
02618         FreeTrainTrackReservation(v);
02619         if (mark_stuck) MarkTrainAsStuck(v);
02620         if (got_reservation != NULL) *got_reservation = false;
02621         changed_signal = false;
02622         break;
02623       }
02624     }
02625     /* No order or no safe position found, try any position. */
02626     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
02627       FreeTrainTrackReservation(v);
02628       if (mark_stuck) MarkTrainAsStuck(v);
02629       if (got_reservation != NULL) *got_reservation = false;
02630       changed_signal = false;
02631     }
02632     break;
02633   }
02634 
02635   TryReserveRailTrack(v->tile, TrackdirToTrack(v->GetVehicleTrackdir()));
02636 
02637   if (changed_signal) MarkTileDirtyByTile(tile);
02638 
02639   return best_track;
02640 }
02641 
02650 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
02651 {
02652   assert(v->IsFrontEngine());
02653 
02654   /* We have to handle depots specially as the track follower won't look
02655    * at the depot tile itself but starts from the next tile. If we are still
02656    * inside the depot, a depot reservation can never be ours. */
02657   if (v->track == TRACK_BIT_DEPOT) {
02658     if (HasDepotReservation(v->tile)) {
02659       if (mark_as_stuck) MarkTrainAsStuck(v);
02660       return false;
02661     } else {
02662       /* Depot not reserved, but the next tile might be. */
02663       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
02664       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
02665     }
02666   }
02667 
02668   Vehicle *other_train = NULL;
02669   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
02670   /* The path we are driving on is already blocked by some other train.
02671    * This can only happen in certain situations when mixing path and
02672    * block signals or when changing tracks and/or signals.
02673    * Exit here as doing any further reservations will probably just
02674    * make matters worse. */
02675   if (other_train != NULL && other_train->index != v->index) {
02676     if (mark_as_stuck) MarkTrainAsStuck(v);
02677     return false;
02678   }
02679   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
02680   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
02681     /* Can't be stuck then. */
02682     if (HasBit(v->flags, VRF_TRAIN_STUCK)) SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02683     ClrBit(v->flags, VRF_TRAIN_STUCK);
02684     return true;
02685   }
02686 
02687   /* If we are in a depot, tentatively reserve the depot. */
02688   if (v->track == TRACK_BIT_DEPOT) {
02689     SetDepotReservation(v->tile, true);
02690     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02691   }
02692 
02693   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
02694   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
02695   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
02696 
02697   if (_settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
02698 
02699   bool res_made = false;
02700   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
02701 
02702   if (!res_made) {
02703     /* Free the depot reservation as well. */
02704     if (v->track == TRACK_BIT_DEPOT) SetDepotReservation(v->tile, false);
02705     return false;
02706   }
02707 
02708   if (HasBit(v->flags, VRF_TRAIN_STUCK)) {
02709     v->wait_counter = 0;
02710     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
02711   }
02712   ClrBit(v->flags, VRF_TRAIN_STUCK);
02713   return true;
02714 }
02715 
02716 
02717 static bool CheckReverseTrain(const Train *v)
02718 {
02719   if (_settings_game.difficulty.line_reverse_mode != 0 ||
02720       v->track == TRACK_BIT_DEPOT || v->track == TRACK_BIT_WORMHOLE ||
02721       !(v->direction & 1)) {
02722     return false;
02723   }
02724 
02725   assert(v->track != TRACK_BIT_NONE);
02726 
02727   switch (_settings_game.pf.pathfinder_for_trains) {
02728     case VPF_NPF: return NPFTrainCheckReverse(v);
02729     case VPF_YAPF: return YapfTrainCheckReverse(v);
02730 
02731     default: NOT_REACHED();
02732   }
02733 }
02734 
02740 TileIndex Train::GetOrderStationLocation(StationID station)
02741 {
02742   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
02743 
02744   const Station *st = Station::Get(station);
02745   if (!(st->facilities & FACIL_TRAIN)) {
02746     /* The destination station has no trainstation tiles. */
02747     this->IncrementRealOrderIndex();
02748     return 0;
02749   }
02750 
02751   return st->xy;
02752 }
02753 
02755 void Train::MarkDirty()
02756 {
02757   Train *v = this;
02758   do {
02759     v->UpdateViewport(false, false);
02760   } while ((v = v->Next()) != NULL);
02761 
02762   /* need to update acceleration and cached values since the goods on the train changed. */
02763   this->CargoChanged();
02764   this->UpdateAcceleration();
02765 }
02766 
02774 int Train::UpdateSpeed()
02775 {
02776   switch (_settings_game.vehicle.train_acceleration_model) {
02777     default: NOT_REACHED();
02778     case AM_ORIGINAL:
02779       return this->DoUpdateSpeed(this->acceleration * (this->GetAccelerationStatus() == AS_BRAKE ? -4 : 2), 0, this->GetCurrentMaxSpeed());
02780 
02781     case AM_REALISTIC:
02782       return this->DoUpdateSpeed(this->GetAcceleration(), this->GetAccelerationStatus() == AS_BRAKE ? 0 : 2, this->GetCurrentMaxSpeed());
02783   }
02784 }
02785 
02791 static void TrainEnterStation(Train *v, StationID station)
02792 {
02793   v->last_station_visited = station;
02794 
02795   /* check if a train ever visited this station before */
02796   Station *st = Station::Get(station);
02797   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
02798     st->had_vehicle_of_type |= HVOT_TRAIN;
02799     SetDParam(0, st->index);
02800     AddVehicleNewsItem(
02801       STR_NEWS_FIRST_TRAIN_ARRIVAL,
02802       v->owner == _local_company ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
02803       v->index,
02804       st->index
02805     );
02806     AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
02807     Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
02808   }
02809 
02810   v->force_proceed = TFP_NONE;
02811   SetWindowDirty(WC_VEHICLE_VIEW, v->index);
02812 
02813   v->BeginLoading();
02814 
02815   TriggerStationRandomisation(st, v->tile, SRT_TRAIN_ARRIVES);
02816   TriggerStationAnimation(st, v->tile, SAT_TRAIN_ARRIVES);
02817 }
02818 
02819 /* Check if the vehicle is compatible with the specified tile */
02820 static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
02821 {
02822   return IsTileOwner(tile, v->owner) &&
02823       (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile)));
02824 }
02825 
02827 struct AccelerationSlowdownParams {
02828   byte small_turn; 
02829   byte large_turn; 
02830   byte z_up;       
02831   byte z_down;     
02832 };
02833 
02835 static const AccelerationSlowdownParams _accel_slowdown[] = {
02836   /* normal accel */
02837   {256 / 4, 256 / 2, 256 / 4, 2}, 
02838   {256 / 4, 256 / 2, 256 / 4, 2}, 
02839   {0,       256 / 2, 256 / 4, 2}, 
02840 };
02841 
02847 static inline void AffectSpeedByZChange(Train *v, int old_z)
02848 {
02849   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return;
02850 
02851   const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
02852 
02853   if (old_z < v->z_pos) {
02854     v->cur_speed -= (v->cur_speed * asp->z_up >> 8);
02855   } else {
02856     uint16 spd = v->cur_speed + asp->z_down;
02857     if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd;
02858   }
02859 }
02860 
02861 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
02862 {
02863   if (IsTileType(tile, MP_RAILWAY) &&
02864       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
02865     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
02866     Trackdir trackdir = FindFirstTrackdir(tracks);
02867     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
02868       /* A PBS block with a non-PBS signal facing us? */
02869       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
02870     }
02871   }
02872   return false;
02873 }
02874 
02876 void Train::ReserveTrackUnderConsist() const
02877 {
02878   for (const Train *u = this; u != NULL; u = u->Next()) {
02879     switch (u->track) {
02880       case TRACK_BIT_WORMHOLE:
02881         TryReserveRailTrack(u->tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(u->tile)));
02882         break;
02883       case TRACK_BIT_DEPOT:
02884         break;
02885       default:
02886         TryReserveRailTrack(u->tile, TrackBitsToTrack(u->track));
02887         break;
02888     }
02889   }
02890 }
02891 
02898 uint Train::Crash(bool flooded)
02899 {
02900   uint pass = 0;
02901   if (this->IsFrontEngine()) {
02902     pass += 2; // driver
02903 
02904     /* Remove the reserved path in front of the train if it is not stuck.
02905      * Also clear all reserved tracks the train is currently on. */
02906     if (!HasBit(this->flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(this);
02907     for (const Train *v = this; v != NULL; v = v->Next()) {
02908       ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
02909       if (IsTileType(v->tile, MP_TUNNELBRIDGE)) {
02910         /* ClearPathReservation will not free the wormhole exit
02911          * if the train has just entered the wormhole. */
02912         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(v->tile), false);
02913       }
02914     }
02915 
02916     /* we may need to update crossing we were approaching,
02917      * but must be updated after the train has been marked crashed */
02918     TileIndex crossing = TrainApproachingCrossingTile(this);
02919     if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
02920 
02921     /* Remove the loading indicators (if any) */
02922     HideFillingPercent(&this->fill_percent_te_id);
02923   }
02924 
02925   pass += this->GroundVehicleBase::Crash(flooded);
02926 
02927   this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded
02928   return pass;
02929 }
02930 
02937 static uint TrainCrashed(Train *v)
02938 {
02939   uint num = 0;
02940 
02941   /* do not crash train twice */
02942   if (!(v->vehstatus & VS_CRASHED)) {
02943     num = v->Crash();
02944     AI::NewEvent(v->owner, new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02945     Game::NewEvent(new ScriptEventVehicleCrashed(v->index, v->tile, ScriptEventVehicleCrashed::CRASH_TRAIN));
02946   }
02947 
02948   /* Try to re-reserve track under already crashed train too.
02949    * Crash() clears the reservation! */
02950   v->ReserveTrackUnderConsist();
02951 
02952   return num;
02953 }
02954 
02956 struct TrainCollideChecker {
02957   Train *v; 
02958   uint num; 
02959 };
02960 
02967 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
02968 {
02969   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
02970 
02971   /* not a train or in depot */
02972   if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return NULL;
02973 
02974   /* do not crash into trains of another company. */
02975   if (v->owner != tcc->v->owner) return NULL;
02976 
02977   /* get first vehicle now to make most usual checks faster */
02978   Train *coll = Train::From(v)->First();
02979 
02980   /* can't collide with own wagons */
02981   if (coll == tcc->v) return NULL;
02982 
02983   int x_diff = v->x_pos - tcc->v->x_pos;
02984   int y_diff = v->y_pos - tcc->v->y_pos;
02985 
02986   /* Do fast calculation to check whether trains are not in close vicinity
02987    * and quickly reject trains distant enough for any collision.
02988    * Differences are shifted by 7, mapping range [-7 .. 8] into [0 .. 15]
02989    * Differences are then ORed and then we check for any higher bits */
02990   uint hash = (y_diff + 7) | (x_diff + 7);
02991   if (hash & ~15) return NULL;
02992 
02993   /* Slower check using multiplication */
02994   int min_diff = (Train::From(v)->gcache.cached_veh_length + 1) / 2 + (tcc->v->gcache.cached_veh_length + 1) / 2 - 1;
02995   if (x_diff * x_diff + y_diff * y_diff > min_diff * min_diff) return NULL;
02996 
02997   /* Happens when there is a train under bridge next to bridge head */
02998   if (abs(v->z_pos - tcc->v->z_pos) > 5) return NULL;
02999 
03000   /* crash both trains */
03001   tcc->num += TrainCrashed(tcc->v);
03002   tcc->num += TrainCrashed(coll);
03003 
03004   return NULL; // continue searching
03005 }
03006 
03014 static bool CheckTrainCollision(Train *v)
03015 {
03016   /* can't collide in depot */
03017   if (v->track == TRACK_BIT_DEPOT) return false;
03018 
03019   assert(v->track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03020 
03021   TrainCollideChecker tcc;
03022   tcc.v = v;
03023   tcc.num = 0;
03024 
03025   /* find colliding vehicles */
03026   if (v->track == TRACK_BIT_WORMHOLE) {
03027     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03028     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03029   } else {
03030     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03031   }
03032 
03033   /* any dead -> no crash */
03034   if (tcc.num == 0) return false;
03035 
03036   SetDParam(0, tcc.num);
03037   AddVehicleNewsItem(STR_NEWS_TRAIN_CRASH, NT_ACCIDENT, v->index);
03038 
03039   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03040   if (_settings_client.sound.disaster) SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03041   return true;
03042 }
03043 
03044 static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
03045 {
03046   if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
03047 
03048   Train *t = Train::From(v);
03049   DiagDirection exitdir = *(DiagDirection *)data;
03050 
03051   /* not front engine of a train, inside wormhole or depot, crashed */
03052   if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
03053 
03054   if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
03055 
03056   return t;
03057 }
03058 
03066 bool TrainController(Train *v, Vehicle *nomove, bool reverse)
03067 {
03068   Train *first = v->First();
03069   Train *prev;
03070   bool direction_changed = false; // has direction of any part changed?
03071 
03072   /* For every vehicle after and including the given vehicle */
03073   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03074     DiagDirection enterdir = DIAGDIR_BEGIN;
03075     bool update_signals_crossing = false; // will we update signals or crossing state?
03076 
03077     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03078     if (v->track != TRACK_BIT_WORMHOLE) {
03079       /* Not inside tunnel */
03080       if (gp.old_tile == gp.new_tile) {
03081         /* Staying in the old tile */
03082         if (v->track == TRACK_BIT_DEPOT) {
03083           /* Inside depot */
03084           gp.x = v->x_pos;
03085           gp.y = v->y_pos;
03086         } else {
03087           /* Not inside depot */
03088 
03089           /* Reverse when we are at the end of the track already, do not move to the new position */
03090           if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v, reverse)) return false;
03091 
03092           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03093           if (HasBit(r, VETS_CANNOT_ENTER)) {
03094             goto invalid_rail;
03095           }
03096           if (HasBit(r, VETS_ENTERED_STATION)) {
03097             /* The new position is the end of the platform */
03098             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03099           }
03100         }
03101       } else {
03102         /* A new tile is about to be entered. */
03103 
03104         /* Determine what direction we're entering the new tile from */
03105         enterdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
03106         assert(IsValidDiagDirection(enterdir));
03107 
03108         /* Get the status of the tracks in the new tile and mask
03109          * away the bits that aren't reachable. */
03110         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03111         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03112 
03113         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03114         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03115 
03116         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03117         if (_settings_game.pf.forbid_90_deg && prev == NULL) {
03118           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03119            * can be switched on halfway a turn */
03120           bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03121         }
03122 
03123         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03124 
03125         /* Check if the new tile constrains tracks that are compatible
03126          * with the current train, if not, bail out. */
03127         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03128 
03129         TrackBits chosen_track;
03130         if (prev == NULL) {
03131           /* Currently the locomotive is active. Determine which one of the
03132            * available tracks to choose */
03133           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03134           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03135 
03136           if (v->force_proceed != TFP_NONE && IsPlainRailTile(gp.new_tile) && HasSignals(gp.new_tile)) {
03137             /* For each signal we find decrease the counter by one.
03138              * We start at two, so the first signal we pass decreases
03139              * this to one, then if we reach the next signal it is
03140              * decreased to zero and we won't pass that new signal. */
03141             Trackdir dir = FindFirstTrackdir(trackdirbits);
03142             if (HasSignalOnTrackdir(gp.new_tile, dir) ||
03143                 (HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(dir)) &&
03144                 GetSignalType(gp.new_tile, TrackdirToTrack(dir)) != SIGTYPE_PBS)) {
03145               /* However, we do not want to be stopped by PBS signals
03146                * entered via the back. */
03147               v->force_proceed = (v->force_proceed == TFP_SIGNAL) ? TFP_STUCK : TFP_NONE;
03148               SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03149             }
03150           }
03151 
03152           /* Check if it's a red signal and that force proceed is not clicked. */
03153           if ((red_signals & chosen_track) && v->force_proceed == TFP_NONE) {
03154             /* In front of a red signal */
03155             Trackdir i = FindFirstTrackdir(trackdirbits);
03156 
03157             /* Don't handle stuck trains here. */
03158             if (HasBit(v->flags, VRF_TRAIN_STUCK)) return false;
03159 
03160             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03161               v->cur_speed = 0;
03162               v->subspeed = 0;
03163               v->progress = 255 - 100;
03164               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_oneway_signal * 20) return false;
03165             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03166               v->cur_speed = 0;
03167               v->subspeed = 0;
03168               v->progress = 255 - 10;
03169               if (!_settings_game.pf.reverse_at_signals || ++v->wait_counter < _settings_game.pf.wait_twoway_signal * 73) {
03170                 DiagDirection exitdir = TrackdirToExitdir(i);
03171                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03172 
03173                 exitdir = ReverseDiagDir(exitdir);
03174 
03175                 /* check if a train is waiting on the other side */
03176                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return false;
03177               }
03178             }
03179 
03180             /* If we would reverse but are currently in a PBS block and
03181              * reversing of stuck trains is disabled, don't reverse.
03182              * This does not apply if the reason for reversing is a one-way
03183              * signal blocking us, because a train would then be stuck forever. */
03184             if (!_settings_game.pf.reverse_at_signals && !HasOnewaySignalBlockingTrackdir(gp.new_tile, i) &&
03185                 UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03186               v->wait_counter = 0;
03187               return false;
03188             }
03189             goto reverse_train_direction;
03190           } else {
03191             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track), false);
03192           }
03193         } else {
03194           /* The wagon is active, simply follow the prev vehicle. */
03195           if (prev->tile == gp.new_tile) {
03196             /* Choose the same track as prev */
03197             if (prev->track == TRACK_BIT_WORMHOLE) {
03198               /* Vehicles entering tunnels enter the wormhole earlier than for bridges.
03199                * However, just choose the track into the wormhole. */
03200               assert(IsTunnel(prev->tile));
03201               chosen_track = bits;
03202             } else {
03203               chosen_track = prev->track;
03204             }
03205           } else {
03206             /* Choose the track that leads to the tile where prev is.
03207              * This case is active if 'prev' is already on the second next tile, when 'v' just enters the next tile.
03208              * I.e. when the tile between them has only space for a single vehicle like
03209              *  1) horizontal/vertical track tiles and
03210              *  2) some orientations of tunnel entries, where the vehicle is already inside the wormhole at 8/16 from the tile edge.
03211              *     Is also the train just reversing, the wagon inside the tunnel is 'on' the tile of the opposite tunnel entry.
03212              */
03213             static const TrackBits _connecting_track[DIAGDIR_END][DIAGDIR_END] = {
03214               {TRACK_BIT_X,     TRACK_BIT_LOWER, TRACK_BIT_NONE,  TRACK_BIT_LEFT },
03215               {TRACK_BIT_UPPER, TRACK_BIT_Y,     TRACK_BIT_LEFT,  TRACK_BIT_NONE },
03216               {TRACK_BIT_NONE,  TRACK_BIT_RIGHT, TRACK_BIT_X,     TRACK_BIT_UPPER},
03217               {TRACK_BIT_RIGHT, TRACK_BIT_NONE,  TRACK_BIT_LOWER, TRACK_BIT_Y    }
03218             };
03219             DiagDirection exitdir = DiagdirBetweenTiles(gp.new_tile, prev->tile);
03220             assert(IsValidDiagDirection(exitdir));
03221             chosen_track = _connecting_track[enterdir][exitdir];
03222           }
03223           chosen_track &= bits;
03224         }
03225 
03226         /* Make sure chosen track is a valid track */
03227         assert(
03228             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03229             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03230             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03231 
03232         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03233         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03234         gp.x = (gp.x & ~0xF) | b[0];
03235         gp.y = (gp.y & ~0xF) | b[1];
03236         Direction chosen_dir = (Direction)b[2];
03237 
03238         /* Call the landscape function and tell it that the vehicle entered the tile */
03239         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03240         if (HasBit(r, VETS_CANNOT_ENTER)) {
03241           goto invalid_rail;
03242         }
03243 
03244         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03245           Track track = FindFirstTrack(chosen_track);
03246           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03247           if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03248             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03249             MarkTileDirtyByTile(gp.new_tile);
03250           }
03251 
03252           /* Clear any track reservation when the last vehicle leaves the tile */
03253           if (v->Next() == NULL) ClearPathReservation(v, v->tile, v->GetVehicleTrackdir());
03254 
03255           v->tile = gp.new_tile;
03256 
03257           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03258             v->First()->ConsistChanged(true);
03259           }
03260 
03261           v->track = chosen_track;
03262           assert(v->track);
03263         }
03264 
03265         /* We need to update signal status, but after the vehicle position hash
03266          * has been updated by UpdateInclination() */
03267         update_signals_crossing = true;
03268 
03269         if (chosen_dir != v->direction) {
03270           if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) {
03271             const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type];
03272             DirDiff diff = DirDifference(v->direction, chosen_dir);
03273             v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8;
03274           }
03275           direction_changed = true;
03276           v->direction = chosen_dir;
03277         }
03278 
03279         if (v->IsFrontEngine()) {
03280           v->wait_counter = 0;
03281 
03282           /* If we are approaching a crossing that is reserved, play the sound now. */
03283           TileIndex crossing = TrainApproachingCrossingTile(v);
03284           if (crossing != INVALID_TILE && HasCrossingReservation(crossing) && _settings_client.sound.ambient) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03285 
03286           /* Always try to extend the reservation when entering a tile. */
03287           CheckNextTrainTile(v);
03288         }
03289 
03290         if (HasBit(r, VETS_ENTERED_STATION)) {
03291           /* The new position is the location where we want to stop */
03292           TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03293         }
03294       }
03295     } else {
03296       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03297         /* Perform look-ahead on tunnel exit. */
03298         if (v->IsFrontEngine()) {
03299           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03300           CheckNextTrainTile(v);
03301         }
03302         /* Prevent v->UpdateInclination() being called with wrong parameters.
03303          * This could happen if the train was reversed inside the tunnel/bridge. */
03304         if (gp.old_tile == gp.new_tile) {
03305           gp.old_tile = GetOtherTunnelBridgeEnd(gp.old_tile);
03306         }
03307       } else {
03308         v->x_pos = gp.x;
03309         v->y_pos = gp.y;
03310         VehicleUpdatePosition(v);
03311         if ((v->vehstatus & VS_HIDDEN) == 0) VehicleUpdateViewport(v, true);
03312         continue;
03313       }
03314     }
03315 
03316     /* update image of train, as well as delta XY */
03317     v->UpdateDeltaXY(v->direction);
03318 
03319     v->x_pos = gp.x;
03320     v->y_pos = gp.y;
03321     VehicleUpdatePosition(v);
03322 
03323     /* update the Z position of the vehicle */
03324     int old_z = v->UpdateInclination(gp.new_tile != gp.old_tile, false);
03325 
03326     if (prev == NULL) {
03327       /* This is the first vehicle in the train */
03328       AffectSpeedByZChange(v, old_z);
03329     }
03330 
03331     if (update_signals_crossing) {
03332       if (v->IsFrontEngine()) {
03333         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03334           /* We are entering a block with PBS signals right now, but
03335            * not through a PBS signal. This means we don't have a
03336            * reservation right now. As a conventional signal will only
03337            * ever be green if no other train is in the block, getting
03338            * a path should always be possible. If the player built
03339            * such a strange network that it is not possible, the train
03340            * will be marked as stuck and the player has to deal with
03341            * the problem. */
03342           if ((!HasReservedTracks(gp.new_tile, v->track) &&
03343               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->track))) ||
03344               !TryPathReserve(v)) {
03345             MarkTrainAsStuck(v);
03346           }
03347         }
03348       }
03349 
03350       /* Signals can only change when the first
03351        * (above) or the last vehicle moves. */
03352       if (v->Next() == NULL) {
03353         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03354         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03355       }
03356     }
03357 
03358     /* Do not check on every tick to save some computing time. */
03359     if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03360   }
03361 
03362   if (direction_changed) first->tcache.cached_max_curve_speed = first->GetCurveSpeedLimit();
03363 
03364   return true;
03365 
03366 invalid_rail:
03367   /* We've reached end of line?? */
03368   if (prev != NULL) error("Disconnecting train");
03369 
03370 reverse_train_direction:
03371   if (reverse) {
03372     v->wait_counter = 0;
03373     v->cur_speed = 0;
03374     v->subspeed = 0;
03375     ReverseTrainDirection(v);
03376   }
03377 
03378   return false;
03379 }
03380 
03387 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03388 {
03389   TrackBits *trackbits = (TrackBits *)data;
03390 
03391   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03392     TrackBits train_tbits = Train::From(v)->track;
03393     if (train_tbits == TRACK_BIT_WORMHOLE) {
03394       /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03395       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03396     } else if (train_tbits != TRACK_BIT_DEPOT) {
03397       *trackbits |= train_tbits;
03398     }
03399   }
03400 
03401   return NULL;
03402 }
03403 
03411 static void DeleteLastWagon(Train *v)
03412 {
03413   Train *first = v->First();
03414 
03415   /* Go to the last wagon and delete the link pointing there
03416    * *u is then the one-before-last wagon, and *v the last
03417    * one which will physically be removed */
03418   Train *u = v;
03419   for (; v->Next() != NULL; v = v->Next()) u = v;
03420   u->SetNext(NULL);
03421 
03422   if (first != v) {
03423     /* Recalculate cached train properties */
03424     first->ConsistChanged(false);
03425     /* Update the depot window if the first vehicle is in depot -
03426      * if v == first, then it is updated in PreDestructor() */
03427     if (first->track == TRACK_BIT_DEPOT) {
03428       SetWindowDirty(WC_VEHICLE_DEPOT, first->tile);
03429     }
03430   }
03431 
03432   /* 'v' shouldn't be accessed after it has been deleted */
03433   TrackBits trackbits = v->track;
03434   TileIndex tile = v->tile;
03435   Owner owner = v->owner;
03436 
03437   delete v;
03438   v = NULL; // make sure nobody will try to read 'v' anymore
03439 
03440   if (trackbits == TRACK_BIT_WORMHOLE) {
03441     /* Vehicle is inside a wormhole, v->track contains no useful value then. */
03442     trackbits = DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03443   }
03444 
03445   Track track = TrackBitsToTrack(trackbits);
03446   if (HasReservedTracks(tile, trackbits)) {
03447     UnreserveRailTrack(tile, track);
03448 
03449     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03450     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03451     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03452 
03453     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03454     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03455     Track t;
03456     FOR_EACH_SET_TRACK(t, remaining_trackbits) TryReserveRailTrack(tile, t);
03457   }
03458 
03459   /* check if the wagon was on a road/rail-crossing */
03460   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03461 
03462   /* Update signals */
03463   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03464     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03465   } else {
03466     SetSignalsOnBothDir(tile, track, owner);
03467   }
03468 }
03469 
03474 static void ChangeTrainDirRandomly(Train *v)
03475 {
03476   static const DirDiff delta[] = {
03477     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03478   };
03479 
03480   do {
03481     /* We don't need to twist around vehicles if they're not visible */
03482     if (!(v->vehstatus & VS_HIDDEN)) {
03483       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03484       v->UpdateDeltaXY(v->direction);
03485       v->cur_image = v->GetImage(v->direction, EIT_ON_MAP);
03486       /* Refrain from updating the z position of the vehicle when on
03487        * a bridge, because UpdateInclination() will put the vehicle under
03488        * the bridge in that case */
03489       if (v->track != TRACK_BIT_WORMHOLE) {
03490         VehicleUpdatePosition(v);
03491         v->UpdateInclination(false, false);
03492       }
03493     }
03494   } while ((v = v->Next()) != NULL);
03495 }
03496 
03502 static bool HandleCrashedTrain(Train *v)
03503 {
03504   int state = ++v->crash_anim_pos;
03505 
03506   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
03507     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
03508   }
03509 
03510   uint32 r;
03511   if (state <= 200 && Chance16R(1, 7, r)) {
03512     int index = (r * 10 >> 16);
03513 
03514     Vehicle *u = v;
03515     do {
03516       if (--index < 0) {
03517         r = Random();
03518 
03519         CreateEffectVehicleRel(u,
03520           GB(r,  8, 3) + 2,
03521           GB(r, 16, 3) + 2,
03522           GB(r,  0, 3) + 5,
03523           EV_EXPLOSION_SMALL);
03524         break;
03525       }
03526     } while ((u = u->Next()) != NULL);
03527   }
03528 
03529   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
03530 
03531   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
03532     bool ret = v->Next() != NULL;
03533     DeleteLastWagon(v);
03534     return ret;
03535   }
03536 
03537   return true;
03538 }
03539 
03541 static const uint16 _breakdown_speeds[16] = {
03542   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
03543 };
03544 
03545 
03554 static bool TrainApproachingLineEnd(Train *v, bool signal, bool reverse)
03555 {
03556   /* Calc position within the current tile */
03557   uint x = v->x_pos & 0xF;
03558   uint y = v->y_pos & 0xF;
03559 
03560   /* for diagonal directions, 'x' will be 0..15 -
03561    * for other directions, it will be 1, 3, 5, ..., 15 */
03562   switch (v->direction) {
03563     case DIR_N : x = ~x + ~y + 25; break;
03564     case DIR_NW: x = y;            // FALL THROUGH
03565     case DIR_NE: x = ~x + 16;      break;
03566     case DIR_E : x = ~x + y + 9;   break;
03567     case DIR_SE: x = y;            break;
03568     case DIR_S : x = x + y - 7;    break;
03569     case DIR_W : x = ~y + x + 9;   break;
03570     default: break;
03571   }
03572 
03573   /* Do not reverse when approaching red signal. Make sure the vehicle's front
03574    * does not cross the tile boundary when we do reverse, but as the vehicle's
03575    * location is based on their center, use half a vehicle's length as offset.
03576    * Multiply the half-length by two for straight directions to compensate that
03577    * we only get odd x offsets there. */
03578   if (!signal && x + (v->gcache.cached_veh_length + 1) / 2 * (IsDiagonalDirection(v->direction) ? 1 : 2) >= TILE_SIZE) {
03579     /* we are too near the tile end, reverse now */
03580     v->cur_speed = 0;
03581     if (reverse) ReverseTrainDirection(v);
03582     return false;
03583   }
03584 
03585   /* slow down */
03586   v->vehstatus |= VS_TRAIN_SLOWING;
03587   uint16 break_speed = _breakdown_speeds[x & 0xF];
03588   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03589 
03590   return true;
03591 }
03592 
03593 
03599 static bool TrainCanLeaveTile(const Train *v)
03600 {
03601   /* Exit if inside a tunnel/bridge or a depot */
03602   if (v->track == TRACK_BIT_WORMHOLE || v->track == TRACK_BIT_DEPOT) return false;
03603 
03604   TileIndex tile = v->tile;
03605 
03606   /* entering a tunnel/bridge? */
03607   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
03608     DiagDirection dir = GetTunnelBridgeDirection(tile);
03609     if (DiagDirToDir(dir) == v->direction) return false;
03610   }
03611 
03612   /* entering a depot? */
03613   if (IsRailDepotTile(tile)) {
03614     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
03615     if (DiagDirToDir(dir) == v->direction) return false;
03616   }
03617 
03618   return true;
03619 }
03620 
03621 
03629 static TileIndex TrainApproachingCrossingTile(const Train *v)
03630 {
03631   assert(v->IsFrontEngine());
03632   assert(!(v->vehstatus & VS_CRASHED));
03633 
03634   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
03635 
03636   DiagDirection dir = TrainExitDir(v->direction, v->track);
03637   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03638 
03639   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
03640   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
03641       !CheckCompatibleRail(v, tile)) {
03642     return INVALID_TILE;
03643   }
03644 
03645   return tile;
03646 }
03647 
03648 
03656 static bool TrainCheckIfLineEnds(Train *v, bool reverse)
03657 {
03658   /* First, handle broken down train */
03659 
03660   int t = v->breakdown_ctr;
03661   if (t > 1) {
03662     v->vehstatus |= VS_TRAIN_SLOWING;
03663 
03664     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
03665     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
03666   } else {
03667     v->vehstatus &= ~VS_TRAIN_SLOWING;
03668   }
03669 
03670   if (!TrainCanLeaveTile(v)) return true;
03671 
03672   /* Determine the non-diagonal direction in which we will exit this tile */
03673   DiagDirection dir = TrainExitDir(v->direction, v->track);
03674   /* Calculate next tile */
03675   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
03676 
03677   /* Determine the track status on the next tile */
03678   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
03679   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
03680 
03681   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03682   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
03683 
03684   /* We are sure the train is not entering a depot, it is detected above */
03685 
03686   /* mask unreachable track bits if we are forbidden to do 90deg turns */
03687   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03688   if (_settings_game.pf.forbid_90_deg) {
03689     bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
03690   }
03691 
03692   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
03693   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
03694     return TrainApproachingLineEnd(v, false, reverse);
03695   }
03696 
03697   /* approaching red signal */
03698   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true, reverse);
03699 
03700   /* approaching a rail/road crossing? then make it red */
03701   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
03702 
03703   return true;
03704 }
03705 
03706 
03707 static bool TrainLocoHandler(Train *v, bool mode)
03708 {
03709   /* train has crashed? */
03710   if (v->vehstatus & VS_CRASHED) {
03711     return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
03712   }
03713 
03714   if (v->force_proceed != TFP_NONE) {
03715     ClrBit(v->flags, VRF_TRAIN_STUCK);
03716     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03717   }
03718 
03719   /* train is broken down? */
03720   if (v->HandleBreakdown()) return true;
03721 
03722   if (HasBit(v->flags, VRF_REVERSING) && v->cur_speed == 0) {
03723     ReverseTrainDirection(v);
03724   }
03725 
03726   /* exit if train is stopped */
03727   if ((v->vehstatus & VS_STOPPED) && v->cur_speed == 0) return true;
03728 
03729   bool valid_order = !v->current_order.IsType(OT_NOTHING) && v->current_order.GetType() != OT_CONDITIONAL;
03730   if (ProcessOrders(v) && CheckReverseTrain(v)) {
03731     v->wait_counter = 0;
03732     v->cur_speed = 0;
03733     v->subspeed = 0;
03734     ClrBit(v->flags, VRF_LEAVING_STATION);
03735     ReverseTrainDirection(v);
03736     return true;
03737   } else if (HasBit(v->flags, VRF_LEAVING_STATION)) {
03738     /* Try to reserve a path when leaving the station as we
03739      * might not be marked as wanting a reservation, e.g.
03740      * when an overlength train gets turned around in a station. */
03741     DiagDirection dir = TrainExitDir(v->direction, v->track);
03742     if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
03743 
03744     if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
03745       TryPathReserve(v, true, true);
03746     }
03747     ClrBit(v->flags, VRF_LEAVING_STATION);
03748   }
03749 
03750   v->HandleLoading(mode);
03751 
03752   if (v->current_order.IsType(OT_LOADING)) return true;
03753 
03754   if (CheckTrainStayInDepot(v)) return true;
03755 
03756   if (!mode) v->ShowVisualEffect();
03757 
03758   /* We had no order but have an order now, do look ahead. */
03759   if (!valid_order && !v->current_order.IsType(OT_NOTHING)) {
03760     CheckNextTrainTile(v);
03761   }
03762 
03763   /* Handle stuck trains. */
03764   if (!mode && HasBit(v->flags, VRF_TRAIN_STUCK)) {
03765     ++v->wait_counter;
03766 
03767     /* Should we try reversing this tick if still stuck? */
03768     bool turn_around = v->wait_counter % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.reverse_at_signals;
03769 
03770     if (!turn_around && v->wait_counter % _settings_game.pf.path_backoff_interval != 0 && v->force_proceed == TFP_NONE) return true;
03771     if (!TryPathReserve(v)) {
03772       /* Still stuck. */
03773       if (turn_around) ReverseTrainDirection(v);
03774 
03775       if (HasBit(v->flags, VRF_TRAIN_STUCK) && v->wait_counter > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
03776         /* Show message to player. */
03777         if (_settings_client.gui.lost_vehicle_warn && v->owner == _local_company) {
03778           SetDParam(0, v->index);
03779           AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_STUCK, v->index);
03780         }
03781         v->wait_counter = 0;
03782       }
03783       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
03784       if (v->force_proceed == TFP_NONE) return true;
03785       ClrBit(v->flags, VRF_TRAIN_STUCK);
03786       v->wait_counter = 0;
03787       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03788     }
03789   }
03790 
03791   if (v->current_order.IsType(OT_LEAVESTATION)) {
03792     v->current_order.Free();
03793     SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03794     return true;
03795   }
03796 
03797   int j = v->UpdateSpeed();
03798 
03799   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
03800   if (v->cur_speed == 0 && (v->vehstatus & VS_STOPPED)) {
03801     /* If we manually stopped, we're not force-proceeding anymore. */
03802     v->force_proceed = TFP_NONE;
03803     SetWindowDirty(WC_VEHICLE_VIEW, v->index);
03804   }
03805 
03806   int adv_spd = v->GetAdvanceDistance();
03807   if (j < adv_spd) {
03808     /* if the vehicle has speed 0, update the last_speed field. */
03809     if (v->cur_speed == 0) v->SetLastSpeed();
03810   } else {
03811     TrainCheckIfLineEnds(v);
03812     /* Loop until the train has finished moving. */
03813     for (;;) {
03814       j -= adv_spd;
03815       TrainController(v, NULL);
03816       /* Don't continue to move if the train crashed. */
03817       if (CheckTrainCollision(v)) break;
03818       /* Determine distance to next map position */
03819       adv_spd = v->GetAdvanceDistance();
03820 
03821       /* No more moving this tick */
03822       if (j < adv_spd || v->cur_speed == 0) break;
03823 
03824       OrderType order_type = v->current_order.GetType();
03825       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
03826       if ((order_type == OT_GOTO_WAYPOINT || order_type == OT_GOTO_STATION) &&
03827             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
03828             IsTileType(v->tile, MP_STATION) &&
03829             v->current_order.GetDestination() == GetStationIndex(v->tile)) {
03830         ProcessOrders(v);
03831       }
03832     }
03833     v->SetLastSpeed();
03834   }
03835 
03836   for (Train *u = v; u != NULL; u = u->Next()) {
03837     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
03838 
03839     u->UpdateViewport(false, false);
03840   }
03841 
03842   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
03843 
03844   return true;
03845 }
03846 
03851 Money Train::GetRunningCost() const
03852 {
03853   Money cost = 0;
03854   const Train *v = this;
03855 
03856   do {
03857     const Engine *e = v->GetEngine();
03858     if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
03859 
03860     uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
03861     if (cost_factor == 0) continue;
03862 
03863     /* Halve running cost for multiheaded parts */
03864     if (v->IsMultiheaded()) cost_factor /= 2;
03865 
03866     cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
03867   } while ((v = v->GetNextVehicle()) != NULL);
03868 
03869   return cost;
03870 }
03871 
03876 bool Train::Tick()
03877 {
03878   this->tick_counter++;
03879 
03880   if (this->IsFrontEngine()) {
03881     if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
03882 
03883     this->current_order_time++;
03884 
03885     if (!TrainLocoHandler(this, false)) return false;
03886 
03887     return TrainLocoHandler(this, true);
03888   } else if (this->IsFreeWagon() && (this->vehstatus & VS_CRASHED)) {
03889     /* Delete flooded standalone wagon chain */
03890     if (++this->crash_anim_pos >= 4400) {
03891       delete this;
03892       return false;
03893     }
03894   }
03895 
03896   return true;
03897 }
03898 
03903 static void CheckIfTrainNeedsService(Train *v)
03904 {
03905   if (Company::Get(v->owner)->settings.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
03906   if (v->IsChainInDepot()) {
03907     VehicleServiceInDepot(v);
03908     return;
03909   }
03910 
03911   uint max_penalty;
03912   switch (_settings_game.pf.pathfinder_for_trains) {
03913     case VPF_NPF:  max_penalty = _settings_game.pf.npf.maximum_go_to_depot_penalty;  break;
03914     case VPF_YAPF: max_penalty = _settings_game.pf.yapf.maximum_go_to_depot_penalty; break;
03915     default: NOT_REACHED();
03916   }
03917 
03918   FindDepotData tfdd = FindClosestTrainDepot(v, max_penalty);
03919   /* Only go to the depot if it is not too far out of our way. */
03920   if (tfdd.best_length == UINT_MAX || tfdd.best_length > max_penalty) {
03921     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
03922       /* If we were already heading for a depot but it has
03923        * suddenly moved farther away, we continue our normal
03924        * schedule? */
03925       v->current_order.MakeDummy();
03926       SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03927     }
03928     return;
03929   }
03930 
03931   DepotID depot = GetDepotIndex(tfdd.tile);
03932 
03933   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
03934       v->current_order.GetDestination() != depot &&
03935       !Chance16(3, 16)) {
03936     return;
03937   }
03938 
03939   SetBit(v->gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
03940   v->current_order.MakeGoToDepot(depot, ODTFB_SERVICE);
03941   v->dest_tile = tfdd.tile;
03942   SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
03943 }
03944 
03946 void Train::OnNewDay()
03947 {
03948   AgeVehicle(this);
03949 
03950   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
03951 
03952   if (this->IsFrontEngine()) {
03953     CheckVehicleBreakdown(this);
03954 
03955     CheckIfTrainNeedsService(this);
03956 
03957     CheckOrders(this);
03958 
03959     /* update destination */
03960     if (this->current_order.IsType(OT_GOTO_STATION)) {
03961       TileIndex tile = Station::Get(this->current_order.GetDestination())->train_station.tile;
03962       if (tile != INVALID_TILE) this->dest_tile = tile;
03963     }
03964 
03965     if (this->running_ticks != 0) {
03966       /* running costs */
03967       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
03968 
03969       this->profit_this_year -= cost.GetCost();
03970       this->running_ticks = 0;
03971 
03972       SubtractMoneyFromCompanyFract(this->owner, cost);
03973 
03974       SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
03975       SetWindowClassesDirty(WC_TRAINS_LIST);
03976     }
03977   }
03978 }
03979 
03984 Trackdir Train::GetVehicleTrackdir() const
03985 {
03986   if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
03987 
03988   if (this->track == TRACK_BIT_DEPOT) {
03989     /* We'll assume the train is facing outwards */
03990     return DiagDirToDiagTrackdir(GetRailDepotDirection(this->tile)); // Train in depot
03991   }
03992 
03993   if (this->track == TRACK_BIT_WORMHOLE) {
03994     /* train in tunnel or on bridge, so just use his direction and assume a diagonal track */
03995     return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
03996   }
03997 
03998   return TrackDirectionToTrackdir(FindFirstTrack(this->track), this->direction);
03999 }