train_cmd.cpp

Go to the documentation of this file.
00001 /* $Id: train_cmd.cpp 17346 2009-09-01 13:16:53Z rubidium $ */
00002 
00005 #include "stdafx.h"
00006 #include "gui.h"
00007 #include "articulated_vehicles.h"
00008 #include "command_func.h"
00009 #include "npf.h"
00010 #include "news_func.h"
00011 #include "engine_func.h"
00012 #include "engine_base.h"
00013 #include "company_func.h"
00014 #include "depot_base.h"
00015 #include "vehicle_gui.h"
00016 #include "train.h"
00017 #include "newgrf_engine.h"
00018 #include "newgrf_sound.h"
00019 #include "newgrf_text.h"
00020 #include "yapf/follow_track.hpp"
00021 #include "group.h"
00022 #include "table/sprites.h"
00023 #include "strings_func.h"
00024 #include "functions.h"
00025 #include "window_func.h"
00026 #include "vehicle_func.h"
00027 #include "sound_func.h"
00028 #include "variables.h"
00029 #include "autoreplace_gui.h"
00030 #include "gfx_func.h"
00031 #include "ai/ai.hpp"
00032 #include "newgrf_station.h"
00033 #include "effectvehicle_func.h"
00034 #include "gamelog.h"
00035 #include "network/network.h"
00036 
00037 #include "table/strings.h"
00038 #include "table/train_cmd.h"
00039 
00040 static Track ChooseTrainTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck);
00041 static bool TrainCheckIfLineEnds(Vehicle *v);
00042 static void TrainController(Vehicle *v, Vehicle *nomove);
00043 static TileIndex TrainApproachingCrossingTile(const Vehicle *v);
00044 static void CheckIfTrainNeedsService(Vehicle *v);
00045 static void CheckNextTrainTile(Vehicle *v);
00046 
00047 static const byte _vehicle_initial_x_fract[4] = {10, 8, 4,  8};
00048 static const byte _vehicle_initial_y_fract[4] = { 8, 4, 8, 10};
00049 
00050 
00058 static inline DiagDirection TrainExitDir(Direction direction, TrackBits track)
00059 {
00060   static const TrackBits state_dir_table[DIAGDIR_END] = { TRACK_BIT_RIGHT, TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER };
00061 
00062   DiagDirection diagdir = DirToDiagDir(direction);
00063 
00064   /* Determine the diagonal direction in which we will exit this tile */
00065   if (!HasBit(direction, 0) && track != state_dir_table[diagdir]) {
00066     diagdir = ChangeDiagDir(diagdir, DIAGDIRDIFF_90LEFT);
00067   }
00068 
00069   return diagdir;
00070 }
00071 
00072 
00077 byte FreightWagonMult(CargoID cargo)
00078 {
00079   if (!GetCargo(cargo)->is_freight) return 1;
00080   return _settings_game.vehicle.freight_trains;
00081 }
00082 
00083 
00088 void TrainPowerChanged(Vehicle *v)
00089 {
00090   uint32 total_power = 0;
00091   uint32 max_te = 0;
00092 
00093   for (const Vehicle *u = v; u != NULL; u = u->Next()) {
00094     RailType railtype = GetRailType(u->tile);
00095 
00096     /* Power is not added for articulated parts */
00097     if (!IsArticulatedPart(u)) {
00098       bool engine_has_power = HasPowerOnRail(u->u.rail.railtype, railtype);
00099 
00100       const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00101 
00102       if (engine_has_power) {
00103         uint16 power = GetVehicleProperty(u, 0x0B, rvi_u->power);
00104         if (power != 0) {
00105           /* Halve power for multiheaded parts */
00106           if (IsMultiheaded(u)) power /= 2;
00107 
00108           total_power += power;
00109           /* Tractive effort in (tonnes * 1000 * 10 =) N */
00110           max_te += (u->u.rail.cached_veh_weight * 10000 * GetVehicleProperty(u, 0x1F, rvi_u->tractive_effort)) / 256;
00111         }
00112       }
00113     }
00114 
00115     if (HasBit(u->u.rail.flags, VRF_POWEREDWAGON) && HasPowerOnRail(v->u.rail.railtype, railtype)) {
00116       total_power += RailVehInfo(u->u.rail.first_engine)->pow_wag_power;
00117     }
00118   }
00119 
00120   if (v->u.rail.cached_power != total_power || v->u.rail.cached_max_te != max_te) {
00121     /* If it has no power (no catenary), stop the train */
00122     if (total_power == 0) v->vehstatus |= VS_STOPPED;
00123 
00124     v->u.rail.cached_power = total_power;
00125     v->u.rail.cached_max_te = max_te;
00126     InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
00127     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
00128   }
00129 }
00130 
00131 
00137 static void TrainCargoChanged(Vehicle *v)
00138 {
00139   uint32 weight = 0;
00140 
00141   for (Vehicle *u = v; u != NULL; u = u->Next()) {
00142     uint32 vweight = GetCargo(u->cargo_type)->weight * u->cargo.Count() * FreightWagonMult(u->cargo_type) / 16;
00143 
00144     /* Vehicle weight is not added for articulated parts. */
00145     if (!IsArticulatedPart(u)) {
00146       /* vehicle weight is the sum of the weight of the vehicle and the weight of its cargo */
00147       vweight += GetVehicleProperty(u, 0x16, RailVehInfo(u->engine_type)->weight);
00148     }
00149 
00150     /* powered wagons have extra weight added */
00151     if (HasBit(u->u.rail.flags, VRF_POWEREDWAGON)) {
00152       vweight += RailVehInfo(u->u.rail.first_engine)->pow_wag_weight;
00153     }
00154 
00155     /* consist weight is the sum of the weight of all vehicles in the consist */
00156     weight += vweight;
00157 
00158     /* store vehicle weight in cache */
00159     u->u.rail.cached_veh_weight = vweight;
00160   }
00161 
00162   /* store consist weight in cache */
00163   v->u.rail.cached_weight = weight;
00164 
00165   /* Now update train power (tractive effort is dependent on weight) */
00166   TrainPowerChanged(v);
00167 }
00168 
00169 
00174 static void RailVehicleLengthChanged(const Vehicle *u)
00175 {
00176   /* show a warning once for each engine in whole game and once for each GRF after each game load */
00177   const Engine *engine = GetEngine(u->engine_type);
00178   uint32 grfid = engine->grffile->grfid;
00179   GRFConfig *grfconfig = GetGRFConfig(grfid);
00180   if (GamelogGRFBugReverse(grfid, engine->internal_id) || !HasBit(grfconfig->grf_bugs, GBUG_VEH_LENGTH)) {
00181     ShowNewGrfVehicleError(u->engine_type, STR_NEWGRF_BROKEN, STR_NEWGRF_BROKEN_VEHICLE_LENGTH, GBUG_VEH_LENGTH, true);
00182   }
00183 }
00184 
00186 void CheckTrainsLengths()
00187 {
00188   const Vehicle *v;
00189 
00190   FOR_ALL_VEHICLES(v) {
00191     if (v->type == VEH_TRAIN && v->First() == v && !(v->vehstatus & VS_CRASHED)) {
00192       for (const Vehicle *u = v, *w = v->Next(); w != NULL; u = w, w = w->Next()) {
00193         if (u->u.rail.track != TRACK_BIT_DEPOT) {
00194           if ((w->u.rail.track != TRACK_BIT_DEPOT &&
00195               max(abs(u->x_pos - w->x_pos), abs(u->y_pos - w->y_pos)) != u->u.rail.cached_veh_length) ||
00196               (w->u.rail.track == TRACK_BIT_DEPOT && TicksToLeaveDepot(u) <= 0)) {
00197             SetDParam(0, v->index);
00198             SetDParam(1, v->owner);
00199             ShowErrorMessage(INVALID_STRING_ID, STR_BROKEN_VEHICLE_LENGTH, 0, 0);
00200 
00201             if (!_networking) _pause_game = -1;
00202           }
00203         }
00204       }
00205     }
00206   }
00207 }
00208 
00216 void TrainConsistChanged(Vehicle *v, bool same_length)
00217 {
00218   uint16 max_speed = UINT16_MAX;
00219 
00220   assert(v->type == VEH_TRAIN);
00221   assert(IsFrontEngine(v) || IsFreeWagon(v));
00222 
00223   const RailVehicleInfo *rvi_v = RailVehInfo(v->engine_type);
00224   EngineID first_engine = IsFrontEngine(v) ? v->engine_type : INVALID_ENGINE;
00225   v->u.rail.cached_total_length = 0;
00226   v->u.rail.compatible_railtypes = RAILTYPES_NONE;
00227 
00228   bool train_can_tilt = true;
00229 
00230   for (Vehicle *u = v; u != NULL; u = u->Next()) {
00231     const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
00232 
00233     /* Check the v->first cache. */
00234     assert(u->First() == v);
00235 
00236     /* update the 'first engine' */
00237     u->u.rail.first_engine = v == u ? INVALID_ENGINE : first_engine;
00238     u->u.rail.railtype = rvi_u->railtype;
00239 
00240     if (IsTrainEngine(u)) first_engine = u->engine_type;
00241 
00242     /* Set user defined data to its default value */
00243     u->u.rail.user_def_data = rvi_u->user_def_data;
00244     v->InvalidateNewGRFCache();
00245     u->InvalidateNewGRFCache();
00246   }
00247 
00248   for (Vehicle *u = v; u != NULL; u = u->Next()) {
00249     /* Update user defined data (must be done before other properties) */
00250     u->u.rail.user_def_data = GetVehicleProperty(u, 0x25, u->u.rail.user_def_data);
00251     v->InvalidateNewGRFCache();
00252     u->InvalidateNewGRFCache();
00253   }
00254 
00255   for (Vehicle *u = v; u != NULL; u = u->Next()) {
00256     const Engine *e_u = GetEngine(u->engine_type);
00257     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00258 
00259     if (!HasBit(EngInfo(u->engine_type)->misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00260 
00261     /* Cache wagon override sprite group. NULL is returned if there is none */
00262     u->u.rail.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->u.rail.first_engine);
00263 
00264     /* Reset colour map */
00265     u->colourmap = PAL_NONE;
00266 
00267     if (rvi_u->visual_effect != 0) {
00268       u->u.rail.cached_vis_effect = rvi_u->visual_effect;
00269     } else {
00270       if (IsTrainWagon(u) || IsArticulatedPart(u)) {
00271         /* Wagons and articulated parts have no effect by default */
00272         u->u.rail.cached_vis_effect = 0x40;
00273       } else if (rvi_u->engclass == 0) {
00274         /* Steam is offset by -4 units */
00275         u->u.rail.cached_vis_effect = 4;
00276       } else {
00277         /* Diesel fumes and sparks come from the centre */
00278         u->u.rail.cached_vis_effect = 8;
00279       }
00280     }
00281 
00282     /* Check powered wagon / visual effect callback */
00283     if (HasBit(EngInfo(u->engine_type)->callbackmask, CBM_TRAIN_WAGON_POWER)) {
00284       uint16 callback = GetVehicleCallback(CBID_TRAIN_WAGON_POWER, 0, 0, u->engine_type, u);
00285 
00286       if (callback != CALLBACK_FAILED) u->u.rail.cached_vis_effect = GB(callback, 0, 8);
00287     }
00288 
00289     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00290       UsesWagonOverride(u) && !HasBit(u->u.rail.cached_vis_effect, 7)) {
00291       /* wagon is powered */
00292       SetBit(u->u.rail.flags, VRF_POWEREDWAGON); // cache 'powered' status
00293     } else {
00294       ClrBit(u->u.rail.flags, VRF_POWEREDWAGON);
00295     }
00296 
00297     if (!IsArticulatedPart(u)) {
00298       /* Do not count powered wagons for the compatible railtypes, as wagons always
00299          have railtype normal */
00300       if (rvi_u->power > 0) {
00301         v->u.rail.compatible_railtypes |= GetRailTypeInfo(u->u.rail.railtype)->powered_railtypes;
00302       }
00303 
00304       /* Some electric engines can be allowed to run on normal rail. It happens to all
00305        * existing electric engines when elrails are disabled and then re-enabled */
00306       if (HasBit(u->u.rail.flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00307         u->u.rail.railtype = RAILTYPE_RAIL;
00308         u->u.rail.compatible_railtypes |= RAILTYPES_RAIL;
00309       }
00310 
00311       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00312       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00313         uint16 speed = GetVehicleProperty(u, 0x09, rvi_u->max_speed);
00314         if (speed != 0) max_speed = min(speed, max_speed);
00315       }
00316     }
00317 
00318     if (e_u->CanCarryCargo() && u->cargo_type == e_u->GetDefaultCargoType() && u->cargo_subtype == 0) {
00319       /* Set cargo capacity if we've not been refitted */
00320       u->cargo_cap = GetVehicleProperty(u, 0x14, rvi_u->capacity);
00321     }
00322 
00323     /* check the vehicle length (callback) */
00324     uint16 veh_len = CALLBACK_FAILED;
00325     if (HasBit(EngInfo(u->engine_type)->callbackmask, CBM_VEHICLE_LENGTH)) {
00326       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00327     }
00328     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00329     veh_len = 8 - Clamp(veh_len, 0, u->Next() == NULL ? 7 : 5); // the clamp on vehicles not the last in chain is stricter, as too short wagons can break the 'follow next vehicle' code
00330 
00331     /* verify length hasn't changed */
00332     if (same_length && veh_len != u->u.rail.cached_veh_length) RailVehicleLengthChanged(u);
00333 
00334     /* update vehicle length? */
00335     if (!same_length) u->u.rail.cached_veh_length = veh_len;
00336 
00337     v->u.rail.cached_total_length += u->u.rail.cached_veh_length;
00338     v->InvalidateNewGRFCache();
00339     u->InvalidateNewGRFCache();
00340   }
00341 
00342   /* store consist weight/max speed in cache */
00343   v->u.rail.cached_max_speed = max_speed;
00344   v->u.rail.cached_tilt = train_can_tilt;
00345 
00346   /* 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) */
00347   TrainCargoChanged(v);
00348 
00349   if (IsFrontEngine(v)) {
00350     UpdateTrainAcceleration(v);
00351     InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
00352   }
00353 }
00354 
00355 enum AccelType {
00356   AM_ACCEL,
00357   AM_BRAKE
00358 };
00359 
00361 static int GetTrainAcceleration(Vehicle *v, bool mode)
00362 {
00363   static const int absolute_max_speed = UINT16_MAX;
00364   int max_speed = absolute_max_speed;
00365   int speed = v->cur_speed * 10 / 16; // km-ish/h -> mp/h
00366   int curvecount[2] = {0, 0};
00367 
00368   /* first find the curve speed limit */
00369   int numcurve = 0;
00370   int sum = 0;
00371   int pos = 0;
00372   int lastpos = -1;
00373   for (const Vehicle *u = v; u->Next() != NULL; u = u->Next(), pos++) {
00374     Direction this_dir = u->direction;
00375     Direction next_dir = u->Next()->direction;
00376 
00377     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00378     if (dirdiff == DIRDIFF_SAME) continue;
00379 
00380     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00381     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00382     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00383       if (lastpos != -1) {
00384         numcurve++;
00385         sum += pos - lastpos;
00386         if (pos - lastpos == 1) {
00387           max_speed = 88;
00388         }
00389       }
00390       lastpos = pos;
00391     }
00392 
00393     /* if we have a 90 degree turn, fix the speed limit to 60 */
00394     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00395       max_speed = 61;
00396     }
00397   }
00398 
00399   if ((curvecount[0] != 0 || curvecount[1] != 0) && max_speed > 88) {
00400     int total = curvecount[0] + curvecount[1];
00401 
00402     if (curvecount[0] == 1 && curvecount[1] == 1) {
00403       max_speed = absolute_max_speed;
00404     } else if (total > 1) {
00405       if (numcurve > 0) sum /= numcurve;
00406       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00407     }
00408   }
00409 
00410   if (max_speed != absolute_max_speed) {
00411     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00412     const RailtypeInfo *rti = GetRailTypeInfo(v->u.rail.railtype);
00413     max_speed += (max_speed / 2) * rti->curve_speed;
00414 
00415     if (v->u.rail.cached_tilt) {
00416       /* Apply max_speed bonus of 20% for a tilting train */
00417       max_speed += max_speed / 5;
00418     }
00419   }
00420 
00421   if (IsTileType(v->tile, MP_STATION) && IsFrontEngine(v)) {
00422     if (v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) {
00423       int station_length = GetStationByTile(v->tile)->GetPlatformLength(v->tile, DirToDiagDir(v->direction));
00424 
00425       int st_max_speed = 120;
00426 
00427       int delta_v = v->cur_speed / (station_length + 1);
00428       if (v->max_speed > (v->cur_speed - delta_v)) {
00429         st_max_speed = v->cur_speed - (delta_v / 10);
00430       }
00431 
00432       st_max_speed = max(st_max_speed, 25 * station_length);
00433       max_speed = min(max_speed, st_max_speed);
00434     }
00435   }
00436 
00437   int mass = v->u.rail.cached_weight;
00438   int power = v->u.rail.cached_power * 746;
00439   max_speed = min(max_speed, v->u.rail.cached_max_speed);
00440 
00441   int num = 0; // number of vehicles, change this into the number of axles later
00442   int incl = 0;
00443   int drag_coeff = 20; //[1e-4]
00444   for (const Vehicle *u = v; u != NULL; u = u->Next()) {
00445     num++;
00446     drag_coeff += 3;
00447 
00448     if (u->u.rail.track == TRACK_BIT_DEPOT) max_speed = min(max_speed, 61);
00449 
00450     if (HasBit(u->u.rail.flags, VRF_GOINGUP)) {
00451       incl += u->u.rail.cached_veh_weight * 60; // 3% slope, quite a bit actually
00452     } else if (HasBit(u->u.rail.flags, VRF_GOINGDOWN)) {
00453       incl -= u->u.rail.cached_veh_weight * 60;
00454     }
00455   }
00456 
00457   v->max_speed = max_speed;
00458 
00459   const int area = 120;
00460   const int friction = 35; //[1e-3]
00461   int resistance;
00462   if (v->u.rail.railtype != RAILTYPE_MAGLEV) {
00463     resistance = 13 * mass / 10;
00464     resistance += 60 * num;
00465     resistance += friction * mass * speed / 1000;
00466     resistance += (area * drag_coeff * speed * speed) / 10000;
00467   } else {
00468     resistance = (area * (drag_coeff / 2) * speed * speed) / 10000;
00469   }
00470   resistance += incl;
00471   resistance *= 4; //[N]
00472 
00473   const int max_te = v->u.rail.cached_max_te; // [N]
00474   int force;
00475   if (speed > 0) {
00476     switch (v->u.rail.railtype) {
00477       case RAILTYPE_RAIL:
00478       case RAILTYPE_ELECTRIC:
00479       case RAILTYPE_MONO:
00480         force = power / speed; //[N]
00481         force *= 22;
00482         force /= 10;
00483         if (mode == AM_ACCEL && force > max_te) force = max_te;
00484         break;
00485 
00486       default: NOT_REACHED();
00487       case RAILTYPE_MAGLEV:
00488         force = power / 25;
00489         break;
00490     }
00491   } else {
00492     /* "kickoff" acceleration */
00493     force = (mode == AM_ACCEL && v->u.rail.railtype != RAILTYPE_MAGLEV) ? min(max_te, power) : power;
00494     force = max(force, (mass * 8) + resistance);
00495   }
00496 
00497   if (mode == AM_ACCEL) {
00498     return (force - resistance) / (mass * 2);
00499   } else {
00500     return min(-force - resistance, -10000) / mass;
00501   }
00502 }
00503 
00504 void UpdateTrainAcceleration(Vehicle *v)
00505 {
00506   assert(IsFrontEngine(v));
00507 
00508   v->max_speed = v->u.rail.cached_max_speed;
00509 
00510   uint power = v->u.rail.cached_power;
00511   uint weight = v->u.rail.cached_weight;
00512   assert(weight != 0);
00513   v->acceleration = Clamp(power / weight * 4, 1, 255);
00514 }
00515 
00516 SpriteID Train::GetImage(Direction direction) const
00517 {
00518   uint8 spritenum = this->spritenum;
00519   SpriteID sprite;
00520 
00521   if (HasBit(this->u.rail.flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00522 
00523   if (is_custom_sprite(spritenum)) {
00524     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)));
00525     if (sprite != 0) return sprite;
00526 
00527     spritenum = GetEngine(this->engine_type)->image_index;
00528   }
00529 
00530   sprite = _engine_sprite_base[spritenum] + ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]);
00531 
00532   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00533 
00534   return sprite;
00535 }
00536 
00537 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y)
00538 {
00539   Direction dir = rear_head ? DIR_E : DIR_W;
00540   uint8 spritenum = RailVehInfo(engine)->image_index;
00541 
00542   if (is_custom_sprite(spritenum)) {
00543     SpriteID sprite = GetCustomVehicleIcon(engine, dir);
00544     if (sprite != 0) {
00545       y += _traininfo_vehicle_pitch; // TODO Make this per-GRF
00546       return sprite;
00547     }
00548 
00549     spritenum = GetEngine(engine)->image_index;
00550   }
00551 
00552   if (rear_head) spritenum++;
00553 
00554   return ((6 + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00555 }
00556 
00557 void DrawTrainEngine(int x, int y, EngineID engine, SpriteID pal)
00558 {
00559   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00560     int yf = y;
00561     int yr = y;
00562 
00563     SpriteID spritef = GetRailIcon(engine, false, yf);
00564     SpriteID spriter = GetRailIcon(engine, true, yr);
00565     DrawSprite(spritef, pal, x - 14, yf);
00566     DrawSprite(spriter, pal, x + 15, yr);
00567   } else {
00568     SpriteID sprite = GetRailIcon(engine, false, y);
00569     DrawSprite(sprite, pal, x, y);
00570   }
00571 }
00572 
00573 static CommandCost CmdBuildRailWagon(EngineID engine, TileIndex tile, DoCommandFlag flags)
00574 {
00575   const Engine *e = GetEngine(engine);
00576   const RailVehicleInfo *rvi = &e->u.rail;
00577   CommandCost value(EXPENSES_NEW_VEHICLES, e->GetCost());
00578 
00579   /* Engines without valid cargo should not be available */
00580   if (e->GetDefaultCargoType() == CT_INVALID) return CMD_ERROR;
00581 
00582   if (flags & DC_QUERY_COST) return value;
00583 
00584   /* Check that the wagon can drive on the track in question */
00585   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00586 
00587   uint num_vehicles = 1 + CountArticulatedParts(engine, false);
00588 
00589   /* Allow for the wagon and the articulated parts, plus one to "terminate" the list. */
00590   Vehicle **vl = AllocaM(Vehicle*, num_vehicles + 1);
00591   memset(vl, 0, sizeof(*vl) * (num_vehicles + 1));
00592 
00593   if (!Vehicle::AllocateList(vl, num_vehicles)) {
00594     return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
00595   }
00596 
00597   if (flags & DC_EXEC) {
00598     Vehicle *v = vl[0];
00599     v->spritenum = rvi->image_index;
00600 
00601     Vehicle *u = NULL;
00602 
00603     Vehicle *w;
00604     FOR_ALL_VEHICLES(w) {
00605       if (w->type == VEH_TRAIN && w->tile == tile &&
00606           IsFreeWagon(w) && w->engine_type == engine &&
00607           !HASBITS(w->vehstatus, VS_CRASHED)) {          
00608         u = GetLastVehicleInChain(w);
00609         break;
00610       }
00611     }
00612 
00613     v = new (v) Train();
00614     v->engine_type = engine;
00615 
00616     DiagDirection dir = GetRailDepotDirection(tile);
00617 
00618     v->direction = DiagDirToDir(dir);
00619     v->tile = tile;
00620 
00621     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00622     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00623 
00624     v->x_pos = x;
00625     v->y_pos = y;
00626     v->z_pos = GetSlopeZ(x, y);
00627     v->owner = _current_company;
00628     v->u.rail.track = TRACK_BIT_DEPOT;
00629     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00630 
00631 //    v->subtype = 0;
00632     SetTrainWagon(v);
00633 
00634     if (u != NULL) {
00635       u->SetNext(v);
00636     } else {
00637       SetFreeWagon(v);
00638       InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00639     }
00640 
00641     v->cargo_type = e->GetDefaultCargoType();
00642 //    v->cargo_subtype = 0;
00643     v->cargo_cap = rvi->capacity;
00644     v->value = value.GetCost();
00645 //    v->day_counter = 0;
00646 
00647     v->u.rail.railtype = rvi->railtype;
00648 
00649     v->build_year = _cur_year;
00650     v->cur_image = 0xAC2;
00651     v->random_bits = VehicleRandomBits();
00652 
00653     v->group_id = DEFAULT_GROUP;
00654 
00655     AddArticulatedParts(vl, VEH_TRAIN);
00656 
00657     _new_vehicle_id = v->index;
00658 
00659     VehicleMove(v, false);
00660     TrainConsistChanged(v->First(), false);
00661     UpdateTrainGroupID(v->First());
00662 
00663     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
00664     if (IsLocalCompany()) {
00665       InvalidateAutoreplaceWindow(v->engine_type, v->group_id); // updates the replace Train window
00666     }
00667     GetCompany(_current_company)->num_engines[engine]++;
00668 
00669     CheckConsistencyOfArticulatedVehicle(v);
00670   }
00671 
00672   return value;
00673 }
00674 
00676 static void NormalizeTrainVehInDepot(const Vehicle *u)
00677 {
00678   const Vehicle *v;
00679 
00680   FOR_ALL_VEHICLES(v) {
00681     if (v->type == VEH_TRAIN && IsFreeWagon(v) &&
00682         v->tile == u->tile &&
00683         v->u.rail.track == TRACK_BIT_DEPOT) {
00684       if (CmdFailed(DoCommand(0, v->index | (u->index << 16), 1, DC_EXEC,
00685           CMD_MOVE_RAIL_VEHICLE)))
00686         break;
00687     }
00688   }
00689 }
00690 
00691 static void AddRearEngineToMultiheadedTrain(Vehicle *v, Vehicle *u, bool building)
00692 {
00693   u = new (u) Train();
00694   u->direction = v->direction;
00695   u->owner = v->owner;
00696   u->tile = v->tile;
00697   u->x_pos = v->x_pos;
00698   u->y_pos = v->y_pos;
00699   u->z_pos = v->z_pos;
00700   u->u.rail.track = TRACK_BIT_DEPOT;
00701   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00702 //  u->subtype = 0;
00703   SetMultiheaded(u);
00704   u->spritenum = v->spritenum + 1;
00705   u->cargo_type = v->cargo_type;
00706   u->cargo_subtype = v->cargo_subtype;
00707   u->cargo_cap = v->cargo_cap;
00708   u->u.rail.railtype = v->u.rail.railtype;
00709   if (building) v->SetNext(u);
00710   u->engine_type = v->engine_type;
00711   u->build_year = v->build_year;
00712   if (building) v->value >>= 1;
00713   u->value = v->value;
00714   u->cur_image = 0xAC2;
00715   u->random_bits = VehicleRandomBits();
00716   VehicleMove(u, false);
00717 }
00718 
00725 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00726 {
00727   /* Check if the engine-type is valid (for the company) */
00728   if (!IsEngineBuildable(p1, VEH_TRAIN, _current_company)) return_cmd_error(STR_RAIL_VEHICLE_NOT_AVAILABLE);
00729 
00730   const Engine *e = GetEngine(p1);
00731   CommandCost value(EXPENSES_NEW_VEHICLES, e->GetCost());
00732 
00733   /* Engines with CT_INVALID should not be available */
00734   if (e->GetDefaultCargoType() == CT_INVALID) return CMD_ERROR;
00735 
00736   if (flags & DC_QUERY_COST) return value;
00737 
00738   /* Check if the train is actually being built in a depot belonging
00739    * to the company. Doesn't matter if only the cost is queried */
00740   if (!IsRailDepotTile(tile)) return CMD_ERROR;
00741   if (!IsTileOwner(tile, _current_company)) return CMD_ERROR;
00742 
00743   const RailVehicleInfo *rvi = RailVehInfo(p1);
00744   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(p1, tile, flags);
00745 
00746   uint num_vehicles =
00747     (rvi->railveh_type == RAILVEH_MULTIHEAD ? 2 : 1) +
00748     CountArticulatedParts(p1, false);
00749 
00750   /* Check if depot and new engine uses the same kind of tracks *
00751    * We need to see if the engine got power on the tile to avoid eletric engines in non-electric depots */
00752   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00753 
00754   /* Allow for the dual-heads and the articulated parts, plus one to "terminate" the list. */
00755   Vehicle **vl = AllocaM(Vehicle*, num_vehicles + 1);
00756   memset(vl, 0, sizeof(*vl) * (num_vehicles + 1));
00757 
00758   if (!Vehicle::AllocateList(vl, num_vehicles)) {
00759     return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
00760   }
00761 
00762   Vehicle *v = vl[0];
00763 
00764   UnitID unit_num = (flags & DC_AUTOREPLACE) ? 0 : GetFreeUnitNumber(VEH_TRAIN);
00765   if (unit_num > _settings_game.vehicle.max_trains) {
00766     return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
00767   }
00768 
00769   if (flags & DC_EXEC) {
00770     DiagDirection dir = GetRailDepotDirection(tile);
00771     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00772     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00773 
00774     v = new (v) Train();
00775     v->unitnumber = unit_num;
00776     v->direction = DiagDirToDir(dir);
00777     v->tile = tile;
00778     v->owner = _current_company;
00779     v->x_pos = x;
00780     v->y_pos = y;
00781     v->z_pos = GetSlopeZ(x, y);
00782 //    v->running_ticks = 0;
00783     v->u.rail.track = TRACK_BIT_DEPOT;
00784     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00785     v->spritenum = rvi->image_index;
00786     v->cargo_type = e->GetDefaultCargoType();
00787 //    v->cargo_subtype = 0;
00788     v->cargo_cap = rvi->capacity;
00789     v->max_speed = rvi->max_speed;
00790     v->value = value.GetCost();
00791     v->last_station_visited = INVALID_STATION;
00792 //    v->dest_tile = 0;
00793 
00794     v->engine_type = p1;
00795 
00796     v->reliability = e->reliability;
00797     v->reliability_spd_dec = e->reliability_spd_dec;
00798     v->max_age = e->lifelength * DAYS_IN_LEAP_YEAR;
00799 
00800     v->name = NULL;
00801     v->u.rail.railtype = rvi->railtype;
00802     _new_vehicle_id = v->index;
00803 
00804     v->service_interval = _settings_game.vehicle.servint_trains;
00805     v->date_of_last_service = _date;
00806     v->build_year = _cur_year;
00807     v->cur_image = 0xAC2;
00808     v->random_bits = VehicleRandomBits();
00809 
00810 //    v->vehicle_flags = 0;
00811     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00812 
00813     v->group_id = DEFAULT_GROUP;
00814 
00815 //    v->subtype = 0;
00816     SetFrontEngine(v);
00817     SetTrainEngine(v);
00818 
00819     VehicleMove(v, false);
00820 
00821     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00822       SetMultiheaded(v);
00823       AddRearEngineToMultiheadedTrain(vl[0], vl[1], true);
00824       /* Now we need to link the front and rear engines together
00825        * other_multiheaded_part is the pointer that links to the other half of the engine
00826        * vl[0] is the front and vl[1] is the rear
00827        */
00828       vl[0]->u.rail.other_multiheaded_part = vl[1];
00829       vl[1]->u.rail.other_multiheaded_part = vl[0];
00830     } else {
00831       AddArticulatedParts(vl, VEH_TRAIN);
00832     }
00833 
00834     TrainConsistChanged(v, false);
00835     UpdateTrainGroupID(v);
00836 
00837     if (!HasBit(p2, 1) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00838       NormalizeTrainVehInDepot(v);
00839     }
00840 
00841     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00842     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
00843     InvalidateWindow(WC_COMPANY, v->owner);
00844     if (IsLocalCompany()) {
00845       InvalidateAutoreplaceWindow(v->engine_type, v->group_id); // updates the replace Train window
00846     }
00847 
00848     GetCompany(_current_company)->num_engines[p1]++;
00849 
00850     CheckConsistencyOfArticulatedVehicle(v);
00851   }
00852 
00853   return value;
00854 }
00855 
00856 
00857 /* Check if all the wagons of the given train are in a depot, returns the
00858  * number of cars (including loco) then. If not it returns -1 */
00859 int CheckTrainInDepot(const Vehicle *v, bool needs_to_be_stopped)
00860 {
00861   TileIndex tile = v->tile;
00862 
00863   /* check if stopped in a depot */
00864   if (!IsRailDepotTile(tile) || v->cur_speed != 0) return -1;
00865 
00866   int count = 0;
00867   for (; v != NULL; v = v->Next()) {
00868     /* This count is used by the depot code to determine the number of engines
00869      * in the consist. Exclude articulated parts so that autoreplacing to
00870      * engines with more articulated parts than before works correctly.
00871      *
00872      * Also skip counting rear ends of multiheaded engines */
00873     if (!IsArticulatedPart(v) && !IsRearDualheaded(v)) count++;
00874     if (v->u.rail.track != TRACK_BIT_DEPOT || v->tile != tile ||
00875         (IsFrontEngine(v) && needs_to_be_stopped && !(v->vehstatus & VS_STOPPED))) {
00876       return -1;
00877     }
00878   }
00879 
00880   return count;
00881 }
00882 
00883 /* Used to check if the train is inside the depot and verifying that the VS_STOPPED flag is set */
00884 int CheckTrainStoppedInDepot(const Vehicle *v)
00885 {
00886   return CheckTrainInDepot(v, true);
00887 }
00888 
00889 /* Used to check if the train is inside the depot, but not checking the VS_STOPPED flag */
00890 inline bool CheckTrainIsInsideDepot(const Vehicle *v)
00891 {
00892   return CheckTrainInDepot(v, false) > 0;
00893 }
00894 
00901 static Vehicle *UnlinkWagon(Vehicle *v, Vehicle *first)
00902 {
00903   /* unlinking the first vehicle of the chain? */
00904   if (v == first) {
00905     v = GetNextVehicle(v);
00906     if (v == NULL) return NULL;
00907 
00908     if (IsTrainWagon(v)) SetFreeWagon(v);
00909 
00910     /* First can be an articulated engine, meaning GetNextVehicle() isn't
00911      * v->Next(). Thus set the next vehicle of the last articulated part
00912      * and the last articulated part is just before the next vehicle (v). */
00913     v->Previous()->SetNext(NULL);
00914 
00915     return v;
00916   }
00917 
00918   Vehicle *u;
00919   for (u = first; GetNextVehicle(u) != v; u = GetNextVehicle(u)) {}
00920   GetLastEnginePart(u)->SetNext(GetNextVehicle(v));
00921   return first;
00922 }
00923 
00924 static Vehicle *FindGoodVehiclePos(const Vehicle *src)
00925 {
00926   Vehicle *dst;
00927   EngineID eng = src->engine_type;
00928   TileIndex tile = src->tile;
00929 
00930   FOR_ALL_VEHICLES(dst) {
00931     if (dst->type == VEH_TRAIN && IsFreeWagon(dst) && dst->tile == tile && !HASBITS(dst->vehstatus, VS_CRASHED)) {
00932       /* check so all vehicles in the line have the same engine. */
00933       Vehicle *v = dst;
00934 
00935       while (v->engine_type == eng) {
00936         v = v->Next();
00937         if (v == NULL) return dst;
00938       }
00939     }
00940   }
00941 
00942   return NULL;
00943 }
00944 
00945 /*
00946  * add a vehicle v behind vehicle dest
00947  * use this function since it sets flags as needed
00948  */
00949 static void AddWagonToConsist(Vehicle *v, Vehicle *dest)
00950 {
00951   UnlinkWagon(v, v->First());
00952   if (dest == NULL) return;
00953 
00954   Vehicle *next = dest->Next();
00955   v->SetNext(NULL);
00956   dest->SetNext(v);
00957   v->SetNext(next);
00958   ClearFreeWagon(v);
00959   ClearFrontEngine(v);
00960 }
00961 
00962 /*
00963  * move around on the train so rear engines are placed correctly according to the other engines
00964  * always call with the front engine
00965  */
00966 static void NormaliseTrainConsist(Vehicle *v)
00967 {
00968   if (IsFreeWagon(v)) return;
00969 
00970   assert(IsFrontEngine(v));
00971 
00972   for (; v != NULL; v = GetNextVehicle(v)) {
00973     if (!IsMultiheaded(v) || !IsTrainEngine(v)) continue;
00974 
00975     /* make sure that there are no free cars before next engine */
00976     Vehicle *u;
00977     for (u = v; u->Next() != NULL && !IsTrainEngine(u->Next()); u = u->Next()) {}
00978 
00979     if (u == v->u.rail.other_multiheaded_part) continue;
00980     AddWagonToConsist(v->u.rail.other_multiheaded_part, u);
00981   }
00982 }
00983 
00993 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00994 {
00995   VehicleID s = GB(p1, 0, 16);
00996   VehicleID d = GB(p1, 16, 16);
00997 
00998   if (!IsValidVehicleID(s)) return CMD_ERROR;
00999 
01000   Vehicle *src = GetVehicle(s);
01001 
01002   if (src->type != VEH_TRAIN || !CheckOwnership(src->owner)) return CMD_ERROR;
01003 
01004   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01005   if (HASBITS(src->vehstatus, VS_CRASHED)) return CMD_ERROR;
01006 
01007   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01008   Vehicle *dst;
01009   if (d == INVALID_VEHICLE) {
01010     dst = IsTrainEngine(src) ? NULL : FindGoodVehiclePos(src);
01011   } else {
01012     if (!IsValidVehicleID(d)) return CMD_ERROR;
01013     dst = GetVehicle(d);
01014     if (dst->type != VEH_TRAIN || !CheckOwnership(dst->owner)) return CMD_ERROR;
01015 
01016     /* Do not allow appending to crashed vehicles, too */
01017     if (HASBITS(dst->vehstatus, VS_CRASHED)) return CMD_ERROR;
01018   }
01019 
01020   /* if an articulated part is being handled, deal with its parent vehicle */
01021   while (IsArticulatedPart(src)) src = src->Previous();
01022   if (dst != NULL) {
01023     while (IsArticulatedPart(dst)) dst = dst->Previous();
01024   }
01025 
01026   /* don't move the same vehicle.. */
01027   if (src == dst) return CommandCost();
01028 
01029   /* locate the head of the two chains */
01030   Vehicle *src_head = src->First();
01031   Vehicle *dst_head;
01032   if (dst != NULL) {
01033     dst_head = dst->First();
01034     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01035     /* Now deal with articulated part of destination wagon */
01036     dst = GetLastEnginePart(dst);
01037   } else {
01038     dst_head = NULL;
01039   }
01040 
01041   if (IsRearDualheaded(src)) return_cmd_error(STR_REAR_ENGINE_FOLLOW_FRONT_ERROR);
01042 
01043   /* when moving all wagons, we can't have the same src_head and dst_head */
01044   if (HasBit(p2, 0) && src_head == dst_head) return CommandCost();
01045 
01046   /* check if all vehicles in the source train are stopped inside a depot. */
01047   int src_len = CheckTrainStoppedInDepot(src_head);
01048   if (src_len < 0) return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01049 
01050   if ((flags & DC_AUTOREPLACE) == 0) {
01051     /* Check whether there are more than 'max_len' train units (articulated parts and rear heads do not count) in the new chain */
01052     int max_len = _settings_game.vehicle.mammoth_trains ? 100 : 10;
01053 
01054     /* check the destination row if the source and destination aren't the same. */
01055     if (src_head != dst_head) {
01056       int dst_len = 0;
01057 
01058       if (dst_head != NULL) {
01059         /* check if all vehicles in the dest train are stopped. */
01060         dst_len = CheckTrainStoppedInDepot(dst_head);
01061         if (dst_len < 0) return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01062       }
01063 
01064       /* We are moving between rows, so only count the wagons from the source
01065        * row that are being moved. */
01066       if (HasBit(p2, 0)) {
01067         const Vehicle *u;
01068         for (u = src_head; u != src && u != NULL; u = GetNextVehicle(u))
01069           src_len--;
01070       } else {
01071         /* If moving only one vehicle, just count that. */
01072         src_len = 1;
01073       }
01074 
01075       if (src_len + dst_len > max_len) {
01076         /* Abort if we're adding too many wagons to a train. */
01077         if (dst_head != NULL && IsFrontEngine(dst_head)) return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01078         /* Abort if we're making a train on a new row. */
01079         if (dst_head == NULL && IsTrainEngine(src)) return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01080       }
01081     } else {
01082       /* Abort if we're creating a new train on an existing row. */
01083       if (src_len > max_len && src == src_head && IsTrainEngine(GetNextVehicle(src_head)))
01084         return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01085     }
01086   }
01087 
01088   /* moving a loco to a new line?, then we need to assign a unitnumber. */
01089   if (dst == NULL && !IsFrontEngine(src) && IsTrainEngine(src)) {
01090     UnitID unit_num = ((flags & DC_AUTOREPLACE) != 0 ? 0 : GetFreeUnitNumber(VEH_TRAIN));
01091     if (unit_num > _settings_game.vehicle.max_trains)
01092       return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
01093 
01094     if (flags & DC_EXEC) src->unitnumber = unit_num;
01095   }
01096 
01097   /* When we move the front vehicle, the second vehicle might need a unitnumber */
01098   if (!HasBit(p2, 0) && (IsFreeWagon(src) || (IsFrontEngine(src) && dst == NULL)) && (flags & DC_AUTOREPLACE) == 0) {
01099     Vehicle *second = GetNextUnit(src);
01100     if (second != NULL && IsTrainEngine(second) && GetFreeUnitNumber(VEH_TRAIN) > _settings_game.vehicle.max_trains) {
01101       return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
01102     }
01103   }
01104 
01105   /*
01106    * Check whether the vehicles in the source chain are in the destination
01107    * chain. This can easily be done by checking whether the first vehicle
01108    * of the source chain is in the destination chain as the Next/Previous
01109    * pointers always make a doubly linked list of it where the assumption
01110    * v->Next()->Previous() == v holds (assuming v->Next() != NULL).
01111    */
01112   bool src_in_dst = false;
01113   for (Vehicle *v = dst_head; !src_in_dst && v != NULL; v = v->Next()) src_in_dst = v == src;
01114 
01115   /*
01116    * If the source chain is in the destination chain then the user is
01117    * only reordering the vehicles, thus not attaching a new vehicle.
01118    * Therefor the 'allow wagon attach' callback does not need to be
01119    * called. If it would be called strange things would happen because
01120    * one 'attaches' an already 'attached' vehicle causing more trouble
01121    * than it actually solves (infinite loops and such).
01122    */
01123   if (dst_head != NULL && !src_in_dst && (flags & DC_AUTOREPLACE) == 0) {
01124     /*
01125      * When performing the 'allow wagon attach' callback, we have to check
01126      * that for each and every wagon, not only the first one. This means
01127      * that we have to test one wagon, attach it to the train and then test
01128      * the next wagon till we have reached the end. We have to restore it
01129      * to the state it was before we 'tried' attaching the train when the
01130      * attaching fails or succeeds because we are not 'only' doing this
01131      * in the DC_EXEC state.
01132      */
01133     Vehicle *dst_tail = dst_head;
01134     while (dst_tail->Next() != NULL) dst_tail = dst_tail->Next();
01135 
01136     Vehicle *orig_tail = dst_tail;
01137     Vehicle *next_to_attach = src;
01138     Vehicle *src_previous = src->Previous();
01139 
01140     while (next_to_attach != NULL) {
01141       /* Don't check callback for articulated or rear dual headed parts */
01142       if (!IsArticulatedPart(next_to_attach) && !IsRearDualheaded(next_to_attach)) {
01143         /* Back up and clear the first_engine data to avoid using wagon override group */
01144         EngineID first_engine = next_to_attach->u.rail.first_engine;
01145         next_to_attach->u.rail.first_engine = INVALID_ENGINE;
01146 
01147         uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, dst_head->engine_type, next_to_attach, dst_head);
01148 
01149         /* Restore original first_engine data */
01150         next_to_attach->u.rail.first_engine = first_engine;
01151 
01152         if (callback != CALLBACK_FAILED) {
01153           StringID error = STR_NULL;
01154 
01155           if (callback == 0xFD) error = STR_INCOMPATIBLE_RAIL_TYPES;
01156           if (callback < 0xFD) error = GetGRFStringID(GetEngineGRFID(dst_head->engine_type), 0xD000 + callback);
01157 
01158           if (error != STR_NULL) {
01159             /*
01160              * The attaching is not allowed. In this case 'next_to_attach'
01161              * can contain some vehicles of the 'source' and the destination
01162              * train can have some too. We 'just' add the to-be added wagons
01163              * to the chain and then split it where it was previously
01164              * separated, i.e. the tail of the original destination train.
01165              * Furthermore the 'previous' link of the original source vehicle needs
01166              * to be restored, otherwise the train goes missing in the depot.
01167              */
01168             dst_tail->SetNext(next_to_attach);
01169             orig_tail->SetNext(NULL);
01170             if (src_previous != NULL) src_previous->SetNext(src);
01171 
01172             return_cmd_error(error);
01173           }
01174         }
01175       }
01176 
01177       /* Only check further wagons if told to move the chain */
01178       if (!HasBit(p2, 0)) break;
01179 
01180       /*
01181        * Adding a next wagon to the chain so we can test the other wagons.
01182        * First 'take' the first wagon from 'next_to_attach' and move it
01183        * to the next wagon. Then add that to the tail of the destination
01184        * train and update the tail with the new vehicle.
01185        */
01186       Vehicle *to_add = next_to_attach;
01187       next_to_attach = next_to_attach->Next();
01188 
01189       to_add->SetNext(NULL);
01190       dst_tail->SetNext(to_add);
01191       dst_tail = dst_tail->Next();
01192     }
01193 
01194     /*
01195      * When we reach this the attaching is allowed. It also means that the
01196      * chain of vehicles to attach is empty, so we do not need to merge that.
01197      * This means only the splitting needs to be done.
01198      * Furthermore the 'previous' link of the original source vehicle needs
01199      * to be restored, otherwise the train goes missing in the depot.
01200      */
01201     orig_tail->SetNext(NULL);
01202     if (src_previous != NULL) src_previous->SetNext(src);
01203   }
01204 
01205   /* do it? */
01206   if (flags & DC_EXEC) {
01207     /* If we move the front Engine and if the second vehicle is not an engine
01208        add the whole vehicle to the DEFAULT_GROUP */
01209     if (IsFrontEngine(src) && !IsDefaultGroupID(src->group_id)) {
01210       Vehicle *v = GetNextVehicle(src);
01211 
01212       if (v != NULL && IsTrainEngine(v)) {
01213         v->group_id   = src->group_id;
01214         src->group_id = DEFAULT_GROUP;
01215       }
01216     }
01217 
01218     if (HasBit(p2, 0)) {
01219       /* unlink ALL wagons */
01220       if (src != src_head) {
01221         Vehicle *v = src_head;
01222         while (GetNextVehicle(v) != src) v = GetNextVehicle(v);
01223         GetLastEnginePart(v)->SetNext(NULL);
01224       } else {
01225         InvalidateWindowData(WC_VEHICLE_DEPOT, src_head->tile); // We removed a line
01226         src_head = NULL;
01227       }
01228     } else {
01229       /* if moving within the same chain, dont use dst_head as it may get invalidated */
01230       if (src_head == dst_head) dst_head = NULL;
01231       /* unlink single wagon from linked list */
01232       src_head = UnlinkWagon(src, src_head);
01233       GetLastEnginePart(src)->SetNext(NULL);
01234     }
01235 
01236     if (dst == NULL) {
01237       /* We make a new line in the depot, so we know already that we invalidate the window data */
01238       InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01239 
01240       /* move the train to an empty line. for locomotives, we set the type to TS_Front. for wagons, 4. */
01241       if (IsTrainEngine(src)) {
01242         if (!IsFrontEngine(src)) {
01243           /* setting the type to 0 also involves setting up the orders field. */
01244           SetFrontEngine(src);
01245           assert(src->orders.list == NULL);
01246 
01247           /* Decrease the engines number of the src engine_type */
01248           if (!IsDefaultGroupID(src->group_id) && IsValidGroupID(src->group_id)) {
01249             GetGroup(src->group_id)->num_engines[src->engine_type]--;
01250           }
01251 
01252           /* If we move an engine to a new line affect it to the DEFAULT_GROUP */
01253           src->group_id = DEFAULT_GROUP;
01254         }
01255       } else {
01256         SetFreeWagon(src);
01257       }
01258       dst_head = src;
01259     } else {
01260       if (IsFrontEngine(src)) {
01261         /* the vehicle was previously a loco. need to free the order list and delete vehicle windows etc. */
01262         DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01263         DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01264         DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01265         DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01266         DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01267         DeleteVehicleOrders(src);
01268         RemoveVehicleFromGroup(src);
01269       }
01270 
01271       if (IsFrontEngine(src) || IsFreeWagon(src)) {
01272         InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01273         ClearFrontEngine(src);
01274         ClearFreeWagon(src);
01275         src->unitnumber = 0; // doesn't occupy a unitnumber anymore.
01276       }
01277 
01278       /* link in the wagon(s) in the chain. */
01279       {
01280         Vehicle *v;
01281 
01282         for (v = src; GetNextVehicle(v) != NULL; v = GetNextVehicle(v)) {}
01283         GetLastEnginePart(v)->SetNext(dst->Next());
01284       }
01285       dst->SetNext(src);
01286     }
01287 
01288     if (src->u.rail.other_multiheaded_part != NULL) {
01289       if (src->u.rail.other_multiheaded_part == src_head) {
01290         src_head = src_head->Next();
01291       }
01292       AddWagonToConsist(src->u.rail.other_multiheaded_part, src);
01293     }
01294 
01295     /* If there is an engine behind first_engine we moved away, it should become new first_engine
01296      * To do this, CmdMoveRailVehicle must be called once more
01297      * we can't loop forever here because next time we reach this line we will have a front engine */
01298     if (src_head != NULL && !IsFrontEngine(src_head) && IsTrainEngine(src_head)) {
01299       /* As in CmdMoveRailVehicle src_head->group_id will be equal to DEFAULT_GROUP
01300        * we need to save the group and reaffect it to src_head */
01301       const GroupID tmp_g = src_head->group_id;
01302       CmdMoveRailVehicle(0, flags, src_head->index | (INVALID_VEHICLE << 16), 1, text);
01303       SetTrainGroupID(src_head, tmp_g);
01304       src_head = NULL; // don't do anything more to this train since the new call will do it
01305     }
01306 
01307     if (src_head != NULL) {
01308       NormaliseTrainConsist(src_head);
01309       TrainConsistChanged(src_head, false);
01310       UpdateTrainGroupID(src_head);
01311       if (IsFrontEngine(src_head)) {
01312         /* Update the refit button and window */
01313         InvalidateWindow(WC_VEHICLE_REFIT, src_head->index);
01314         InvalidateWindowWidget(WC_VEHICLE_VIEW, src_head->index, VVW_WIDGET_REFIT_VEH);
01315       }
01316       /* Update the depot window */
01317       InvalidateWindow(WC_VEHICLE_DEPOT, src_head->tile);
01318     }
01319 
01320     if (dst_head != NULL) {
01321       NormaliseTrainConsist(dst_head);
01322       TrainConsistChanged(dst_head, false);
01323       UpdateTrainGroupID(dst_head);
01324       if (IsFrontEngine(dst_head)) {
01325         /* Update the refit button and window */
01326         InvalidateWindowWidget(WC_VEHICLE_VIEW, dst_head->index, VVW_WIDGET_REFIT_VEH);
01327         InvalidateWindow(WC_VEHICLE_REFIT, dst_head->index);
01328       }
01329       /* Update the depot window */
01330       InvalidateWindow(WC_VEHICLE_DEPOT, dst_head->tile);
01331     }
01332 
01333     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01334   }
01335 
01336   return CommandCost();
01337 }
01338 
01348 CommandCost CmdSellRailWagon(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01349 {
01350   /* Check if we deleted a vehicle window */
01351   Window *w = NULL;
01352 
01353   if (!IsValidVehicleID(p1) || p2 > 1) return CMD_ERROR;
01354 
01355   Vehicle *v = GetVehicle(p1);
01356 
01357   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01358 
01359   if (HASBITS(v->vehstatus, VS_CRASHED)) return_cmd_error(STR_CAN_T_SELL_DESTROYED_VEHICLE);
01360 
01361   while (IsArticulatedPart(v)) v = v->Previous();
01362   Vehicle *first = v->First();
01363 
01364   /* make sure the vehicle is stopped in the depot */
01365   if (CheckTrainStoppedInDepot(first) < 0) {
01366     return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01367   }
01368 
01369   if (IsRearDualheaded(v)) return_cmd_error(STR_REAR_ENGINE_FOLLOW_FRONT_ERROR);
01370 
01371   if (flags & DC_EXEC) {
01372     if (v == first && IsFrontEngine(first)) {
01373       DeleteWindowById(WC_VEHICLE_VIEW, first->index);
01374       DeleteWindowById(WC_VEHICLE_ORDERS, first->index);
01375       DeleteWindowById(WC_VEHICLE_REFIT, first->index);
01376       DeleteWindowById(WC_VEHICLE_DETAILS, first->index);
01377       DeleteWindowById(WC_VEHICLE_TIMETABLE, first->index);
01378     }
01379     InvalidateWindow(WC_VEHICLE_DEPOT, first->tile);
01380     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01381   }
01382 
01383   CommandCost cost(EXPENSES_NEW_VEHICLES);
01384   switch (p2) {
01385     case 0: { // Delete given wagon
01386       bool switch_engine = false;    // update second wagon to engine?
01387 
01388       /* 1. Delete the engine, if it is dualheaded also delete the matching
01389        * rear engine of the loco (from the point of deletion onwards) */
01390       Vehicle *rear = (IsMultiheaded(v) &&
01391         IsTrainEngine(v)) ? v->u.rail.other_multiheaded_part : NULL;
01392 
01393       if (rear != NULL) {
01394         cost.AddCost(-rear->value);
01395         if (flags & DC_EXEC) {
01396           UnlinkWagon(rear, first);
01397           delete rear;
01398         }
01399       }
01400 
01401       /* 2. We are selling the front vehicle, some special action might be required
01402        * here, so take attention */
01403       if (v == first) {
01404         Vehicle *new_f = GetNextVehicle(first);
01405 
01406         /* 2.2 If there are wagons present after the deleted front engine, check
01407          * if the second wagon (which will be first) is an engine. If it is one,
01408          * promote it as a new train, retaining the unitnumber, orders */
01409         if (new_f != NULL && IsTrainEngine(new_f)) {
01410           if (IsTrainEngine(first)) {
01411             /* Let the new front engine take over the setup of the old engine */
01412             switch_engine = true;
01413 
01414             if (flags & DC_EXEC) {
01415               /* Make sure the group counts stay correct. */
01416               new_f->group_id        = first->group_id;
01417               first->group_id        = DEFAULT_GROUP;
01418 
01419               /* Copy orders (by sharing) */
01420               new_f->orders.list     = first->orders.list;
01421               new_f->AddToShared(first);
01422               DeleteVehicleOrders(first);
01423 
01424               /* Copy other important data from the front engine */
01425               new_f->CopyVehicleConfigAndStatistics(first);
01426 
01427               /* If we deleted a window then open a new one for the 'new' train */
01428               if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_f);
01429             }
01430           } else {
01431             /* We are selling a free wagon, and construct a new train at the same time.
01432              * This needs lots of extra checks (e.g. train limit), which are done by first moving
01433              * the remaining vehicles to a new row */
01434             cost.AddCost(DoCommand(0, new_f->index | INVALID_VEHICLE << 16, 1, flags, CMD_MOVE_RAIL_VEHICLE));
01435             if (cost.Failed()) return cost;
01436           }
01437         }
01438       }
01439 
01440       /* 3. Delete the requested wagon */
01441       cost.AddCost(-v->value);
01442       if (flags & DC_EXEC) {
01443         first = UnlinkWagon(v, first);
01444         delete v;
01445 
01446         /* 4 If the second wagon was an engine, update it to front_engine
01447          * which UnlinkWagon() has changed to TS_Free_Car */
01448         if (switch_engine) SetFrontEngine(first);
01449 
01450         /* 5. If the train still exists, update its acceleration, window, etc. */
01451         if (first != NULL) {
01452           NormaliseTrainConsist(first);
01453           TrainConsistChanged(first, false);
01454           UpdateTrainGroupID(first);
01455           if (IsFrontEngine(first)) InvalidateWindow(WC_VEHICLE_REFIT, first->index);
01456         }
01457 
01458       }
01459     } break;
01460     case 1: { // Delete wagon and all wagons after it given certain criteria
01461       /* Start deleting every vehicle after the selected one
01462        * If we encounter a matching rear-engine to a front-engine
01463        * earlier in the chain (before deletion), leave it alone */
01464       for (Vehicle *tmp; v != NULL; v = tmp) {
01465         tmp = GetNextVehicle(v);
01466 
01467         if (IsMultiheaded(v)) {
01468           if (IsTrainEngine(v)) {
01469             /* We got a front engine of a multiheaded set. Now we will sell the rear end too */
01470             Vehicle *rear = v->u.rail.other_multiheaded_part;
01471 
01472             if (rear != NULL) {
01473               cost.AddCost(-rear->value);
01474 
01475               /* If this is a multiheaded vehicle with nothing
01476                * between the parts, tmp will be pointing to the
01477                * rear part, which is unlinked from the train and
01478                * deleted here. However, because tmp has already
01479                * been set it needs to be updated now so that the
01480                * loop never sees the rear part. */
01481               if (tmp == rear) tmp = GetNextVehicle(tmp);
01482 
01483               if (flags & DC_EXEC) {
01484                 first = UnlinkWagon(rear, first);
01485                 delete rear;
01486               }
01487             }
01488           } else if (v->u.rail.other_multiheaded_part != NULL) {
01489             /* The front to this engine is earlier in this train. Do nothing */
01490             continue;
01491           }
01492         }
01493 
01494         cost.AddCost(-v->value);
01495         if (flags & DC_EXEC) {
01496           first = UnlinkWagon(v, first);
01497           delete v;
01498         }
01499       }
01500 
01501       /* 3. If it is still a valid train after selling, update its acceleration and cached values */
01502       if (flags & DC_EXEC && first != NULL) {
01503         NormaliseTrainConsist(first);
01504         TrainConsistChanged(first, false);
01505         UpdateTrainGroupID(first);
01506         InvalidateWindow(WC_VEHICLE_REFIT, first->index);
01507       }
01508     } break;
01509   }
01510   return cost;
01511 }
01512 
01513 void Train::UpdateDeltaXY(Direction direction)
01514 {
01515 #define MKIT(a, b, c, d) ((a & 0xFF) << 24) | ((b & 0xFF) << 16) | ((c & 0xFF) << 8) | ((d & 0xFF) << 0)
01516   static const uint32 _delta_xy_table[8] = {
01517     MKIT(3, 3, -1, -1),
01518     MKIT(3, 7, -1, -3),
01519     MKIT(3, 3, -1, -1),
01520     MKIT(7, 3, -3, -1),
01521     MKIT(3, 3, -1, -1),
01522     MKIT(3, 7, -1, -3),
01523     MKIT(3, 3, -1, -1),
01524     MKIT(7, 3, -3, -1),
01525   };
01526 #undef MKIT
01527 
01528   uint32 x = _delta_xy_table[direction];
01529   this->x_offs        = GB(x,  0, 8);
01530   this->y_offs        = GB(x,  8, 8);
01531   this->x_extent      = GB(x, 16, 8);
01532   this->y_extent      = GB(x, 24, 8);
01533   this->z_extent      = 6;
01534 }
01535 
01536 static inline void SetLastSpeed(Vehicle *v, int spd)
01537 {
01538   int old = v->u.rail.last_speed;
01539   if (spd != old) {
01540     v->u.rail.last_speed = spd;
01541     if (_settings_client.gui.vehicle_speed || (old == 0) != (spd == 0)) {
01542       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01543     }
01544   }
01545 }
01546 
01548 static void MarkTrainAsStuck(Vehicle *v)
01549 {
01550   if (!HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
01551     /* It is the first time the problem occured, set the "train stuck" flag. */
01552     SetBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01553 
01554     /* When loading the vehicle is already stopped. No need to change that. */
01555     if (v->current_order.IsType(OT_LOADING)) return;
01556 
01557     v->load_unload_time_rem = 0;
01558 
01559     /* Stop train */
01560     v->cur_speed = 0;
01561     v->subspeed = 0;
01562     SetLastSpeed(v, 0);
01563 
01564     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01565   }
01566 }
01567 
01568 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01569 {
01570   uint16 flag1 = *swap_flag1;
01571   uint16 flag2 = *swap_flag2;
01572 
01573   /* Clear the flags */
01574   ClrBit(*swap_flag1, VRF_GOINGUP);
01575   ClrBit(*swap_flag1, VRF_GOINGDOWN);
01576   ClrBit(*swap_flag2, VRF_GOINGUP);
01577   ClrBit(*swap_flag2, VRF_GOINGDOWN);
01578 
01579   /* Reverse the rail-flags (if needed) */
01580   if (HasBit(flag1, VRF_GOINGUP)) {
01581     SetBit(*swap_flag2, VRF_GOINGDOWN);
01582   } else if (HasBit(flag1, VRF_GOINGDOWN)) {
01583     SetBit(*swap_flag2, VRF_GOINGUP);
01584   }
01585   if (HasBit(flag2, VRF_GOINGUP)) {
01586     SetBit(*swap_flag1, VRF_GOINGDOWN);
01587   } else if (HasBit(flag2, VRF_GOINGDOWN)) {
01588     SetBit(*swap_flag1, VRF_GOINGUP);
01589   }
01590 }
01591 
01592 static void ReverseTrainSwapVeh(Vehicle *v, int l, int r)
01593 {
01594   Vehicle *a, *b;
01595 
01596   /* locate vehicles to swap */
01597   for (a = v; l != 0; l--) a = a->Next();
01598   for (b = v; r != 0; r--) b = b->Next();
01599 
01600   if (a != b) {
01601     /* swap the hidden bits */
01602     {
01603       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus&VS_HIDDEN);
01604       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus&VS_HIDDEN);
01605       a->vehstatus = tmp;
01606     }
01607 
01608     Swap(a->u.rail.track, b->u.rail.track);
01609     Swap(a->direction,    b->direction);
01610 
01611     /* toggle direction */
01612     if (a->u.rail.track != TRACK_BIT_DEPOT) a->direction = ReverseDir(a->direction);
01613     if (b->u.rail.track != TRACK_BIT_DEPOT) b->direction = ReverseDir(b->direction);
01614 
01615     Swap(a->x_pos, b->x_pos);
01616     Swap(a->y_pos, b->y_pos);
01617     Swap(a->tile,  b->tile);
01618     Swap(a->z_pos, b->z_pos);
01619 
01620     SwapTrainFlags(&a->u.rail.flags, &b->u.rail.flags);
01621 
01622     /* update other vars */
01623     a->UpdateViewport(true, true);
01624     b->UpdateViewport(true, true);
01625 
01626     /* call the proper EnterTile function unless we are in a wormhole */
01627     if (a->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
01628     if (b->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(b, b->tile, b->x_pos, b->y_pos);
01629   } else {
01630     if (a->u.rail.track != TRACK_BIT_DEPOT) a->direction = ReverseDir(a->direction);
01631     a->UpdateViewport(true, true);
01632 
01633     if (a->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
01634   }
01635 
01636   /* Update train's power incase tiles were different rail type */
01637   TrainPowerChanged(v);
01638 }
01639 
01640 
01646 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01647 {
01648   return (v->type == VEH_TRAIN) ? v : NULL;
01649 }
01650 
01651 
01658 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01659 {
01660   /* not a train || not front engine || crashed */
01661   if (v->type != VEH_TRAIN || !IsFrontEngine(v) || v->vehstatus & VS_CRASHED) return NULL;
01662 
01663   TileIndex tile = *(TileIndex*)data;
01664 
01665   if (TrainApproachingCrossingTile(v) != tile) return NULL;
01666 
01667   return v;
01668 }
01669 
01670 
01677 static bool TrainApproachingCrossing(TileIndex tile)
01678 {
01679   assert(IsLevelCrossingTile(tile));
01680 
01681   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01682   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01683 
01684   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01685 
01686   dir = ReverseDiagDir(dir);
01687   tile_from = tile + TileOffsByDiagDir(dir);
01688 
01689   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01690 }
01691 
01692 
01699 void UpdateLevelCrossing(TileIndex tile, bool sound)
01700 {
01701   assert(IsLevelCrossingTile(tile));
01702 
01703   /* train on crossing || train approaching crossing || reserved */
01704   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || GetCrossingReservation(tile);
01705 
01706   if (new_state != IsCrossingBarred(tile)) {
01707     if (new_state && sound) {
01708       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01709     }
01710     SetCrossingBarred(tile, new_state);
01711     MarkTileDirtyByTile(tile);
01712   }
01713 }
01714 
01715 
01721 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01722 {
01723   if (!IsCrossingBarred(tile)) {
01724     BarCrossing(tile);
01725     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01726     MarkTileDirtyByTile(tile);
01727   }
01728 }
01729 
01730 
01736 static void AdvanceWagonsBeforeSwap(Vehicle *v)
01737 {
01738   Vehicle *base = v;
01739   Vehicle *first = base;                    // first vehicle to move
01740   Vehicle *last = GetLastVehicleInChain(v); // last vehicle to move
01741   uint length = CountVehiclesInChain(v);
01742 
01743   while (length > 2) {
01744     last = last->Previous();
01745     first = first->Next();
01746 
01747     int differential = base->u.rail.cached_veh_length - last->u.rail.cached_veh_length;
01748 
01749     /* do not update images now
01750      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01751     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01752 
01753     base = first; // == base->Next()
01754     length -= 2;
01755   }
01756 }
01757 
01758 
01764 static void AdvanceWagonsAfterSwap(Vehicle *v)
01765 {
01766   /* first of all, fix the situation when the train was entering a depot */
01767   Vehicle *dep = v; // last vehicle in front of just left depot
01768   while (dep->Next() != NULL && (dep->u.rail.track == TRACK_BIT_DEPOT || dep->Next()->u.rail.track != TRACK_BIT_DEPOT)) {
01769     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01770   }
01771 
01772   Vehicle *leave = dep->Next(); // first vehicle in a depot we are leaving now
01773 
01774   if (leave != NULL) {
01775     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01776     int d = TicksToLeaveDepot(dep);
01777 
01778     if (d <= 0) {
01779       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01780       leave->u.rail.track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01781       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01782     }
01783   } else {
01784     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01785   }
01786 
01787   Vehicle *base = v;
01788   Vehicle *first = base;                    // first vehicle to move
01789   Vehicle *last = GetLastVehicleInChain(v); // last vehicle to move
01790   uint length = CountVehiclesInChain(v);
01791 
01792   /* we have to make sure all wagons that leave a depot because of train reversing are moved coorectly
01793    * they have already correct spacing, so we have to make sure they are moved how they should */
01794   bool nomove = (dep == NULL); // if there is no vehicle leaving a depot, limit the number of wagons moved immediatelly
01795 
01796   while (length > 2) {
01797     /* we reached vehicle (originally) in front of a depot, stop now
01798      * (we would move wagons that are alredy moved with new wagon length) */
01799     if (base == dep) break;
01800 
01801     /* the last wagon was that one leaving a depot, so do not move it anymore */
01802     if (last == dep) nomove = true;
01803 
01804     last = last->Previous();
01805     first = first->Next();
01806 
01807     int differential = last->u.rail.cached_veh_length - base->u.rail.cached_veh_length;
01808 
01809     /* do not update images now */
01810     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01811 
01812     base = first; // == base->Next()
01813     length -= 2;
01814   }
01815 }
01816 
01817 
01818 static void ReverseTrainDirection(Vehicle *v)
01819 {
01820   if (IsRailDepotTile(v->tile)) {
01821     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01822   }
01823 
01824   /* Clear path reservation in front if train is not stuck. */
01825   if (!HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01826 
01827   /* Check if we were approaching a rail/road-crossing */
01828   TileIndex crossing = TrainApproachingCrossingTile(v);
01829 
01830   /* count number of vehicles */
01831   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01832 
01833   AdvanceWagonsBeforeSwap(v);
01834 
01835   /* swap start<>end, start+1<>end-1, ... */
01836   int l = 0;
01837   do {
01838     ReverseTrainSwapVeh(v, l++, r--);
01839   } while (l <= r);
01840 
01841   AdvanceWagonsAfterSwap(v);
01842 
01843   if (IsRailDepotTile(v->tile)) {
01844     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01845   }
01846 
01847   ToggleBit(v->u.rail.flags, VRF_TOGGLE_REVERSE);
01848 
01849   ClrBit(v->u.rail.flags, VRF_REVERSING);
01850 
01851   /* recalculate cached data */
01852   TrainConsistChanged(v, true);
01853 
01854   /* update all images */
01855   for (Vehicle *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01856 
01857   /* update crossing we were approaching */
01858   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01859 
01860   /* maybe we are approaching crossing now, after reversal */
01861   crossing = TrainApproachingCrossingTile(v);
01862   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01863 
01864   /* If we are inside a depot after reversing, don't bother with path reserving. */
01865   if (v->u.rail.track & TRACK_BIT_DEPOT) {
01866     /* Can't be stuck here as inside a depot is always a safe tile. */
01867     if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01868     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01869     return;
01870   }
01871 
01872   /* TrainExitDir does not always produce the desired dir for depots and
01873    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01874   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
01875   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01876 
01877   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01878     /* If we are currently on a tile with conventional signals, we can't treat the
01879      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01880     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01881       HasSignalOnTrackdir(v->tile, GetVehicleTrackdir(v)) &&
01882       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->u.rail.track))));
01883 
01884     if (IsRailwayStationTile(v->tile)) SetRailwayStationPlatformReservation(v->tile, TrackdirToExitdir(GetVehicleTrackdir(v)), true);
01885     if (TryPathReserve(v, false, first_tile_okay)) {
01886       /* Do a look-ahead now in case our current tile was already a safe tile. */
01887       CheckNextTrainTile(v);
01888     } else if (v->current_order.GetType() != OT_LOADING) {
01889       /* Do not wait for a way out when we're still loading */
01890       MarkTrainAsStuck(v);
01891     }
01892   } else if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
01893     /* A train not inside a PBS block can't be stuck. */
01894     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01895     v->load_unload_time_rem = 0;
01896   }
01897 }
01898 
01905 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01906 {
01907   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01908 
01909   Vehicle *v = GetVehicle(p1);
01910 
01911   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01912 
01913   if (p2 != 0) {
01914     /* turn a single unit around */
01915 
01916     if (IsMultiheaded(v) || HasBit(EngInfo(v->engine_type)->callbackmask, CBM_VEHICLE_ARTIC_ENGINE)) {
01917       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01918     }
01919 
01920     Vehicle *front = v->First();
01921     /* make sure the vehicle is stopped in the depot */
01922     if (CheckTrainStoppedInDepot(front) < 0) {
01923       return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01924     }
01925 
01926     if (flags & DC_EXEC) {
01927       ToggleBit(v->u.rail.flags, VRF_REVERSE_DIRECTION);
01928       InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
01929       InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
01930     }
01931   } else {
01932     /* turn the whole train around */
01933     if (v->vehstatus & VS_CRASHED || v->breakdown_ctr != 0) return CMD_ERROR;
01934 
01935     if (flags & DC_EXEC) {
01936       /* Properly leave the station if we are loading and won't be loading anymore */
01937       if (v->current_order.IsType(OT_LOADING)) {
01938         const Vehicle *last = v;
01939         while (last->Next() != NULL) last = last->Next();
01940 
01941         /* not a station || different station --> leave the station */
01942         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01943           v->LeaveStation();
01944         }
01945       }
01946 
01947       if (_settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL && v->cur_speed != 0) {
01948         ToggleBit(v->u.rail.flags, VRF_REVERSING);
01949       } else {
01950         v->cur_speed = 0;
01951         SetLastSpeed(v, 0);
01952         HideFillingPercent(&v->fill_percent_te_id);
01953         ReverseTrainDirection(v);
01954       }
01955     }
01956   }
01957   return CommandCost();
01958 }
01959 
01966 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01967 {
01968   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01969 
01970   Vehicle *v = GetVehicle(p1);
01971 
01972   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01973 
01974   if (flags & DC_EXEC) v->u.rail.force_proceed = 0x50;
01975 
01976   return CommandCost();
01977 }
01978 
01989 CommandCost CmdRefitRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01990 {
01991   CargoID new_cid = GB(p2, 0, 8);
01992   byte new_subtype = GB(p2, 8, 8);
01993   bool only_this = HasBit(p2, 16);
01994 
01995   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01996 
01997   Vehicle *v = GetVehicle(p1);
01998 
01999   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
02000   if (CheckTrainStoppedInDepot(v) < 0) return_cmd_error(STR_TRAIN_MUST_BE_STOPPED);
02001   if (v->vehstatus & VS_CRASHED) return_cmd_error(STR_CAN_T_REFIT_DESTROYED_VEHICLE);
02002 
02003   /* Check cargo */
02004   if (new_cid >= NUM_CARGO) return CMD_ERROR;
02005 
02006   CommandCost cost(EXPENSES_TRAIN_RUN);
02007   uint num = 0;
02008 
02009   do {
02010     /* XXX: We also refit all the attached wagons en-masse if they
02011      * can be refitted. This is how TTDPatch does it.  TODO: Have
02012      * some nice [Refit] button near each wagon. --pasky */
02013     if (!CanRefitTo(v->engine_type, new_cid)) continue;
02014 
02015     const Engine *e = GetEngine(v->engine_type);
02016     if (e->CanCarryCargo()) {
02017       uint16 amount = CALLBACK_FAILED;
02018 
02019       if (HasBit(EngInfo(v->engine_type)->callbackmask, CBM_VEHICLE_REFIT_CAPACITY)) {
02020         /* Back up the vehicle's cargo type */
02021         CargoID temp_cid = v->cargo_type;
02022         byte temp_subtype = v->cargo_subtype;
02023         v->cargo_type = new_cid;
02024         v->cargo_subtype = new_subtype;
02025         /* Check the refit capacity callback */
02026         amount = GetVehicleCallback(CBID_VEHICLE_REFIT_CAPACITY, 0, 0, v->engine_type, v);
02027         /* Restore the original cargo type */
02028         v->cargo_type = temp_cid;
02029         v->cargo_subtype = temp_subtype;
02030       }
02031 
02032       if (amount == CALLBACK_FAILED) { // callback failed or not used, use default
02033         CargoID old_cid = e->GetDefaultCargoType();
02034         /* normally, the capacity depends on the cargo type, a rail vehicle can
02035          * carry twice as much mail/goods as normal cargo, and four times as
02036          * many passengers
02037          */
02038         amount = e->u.rail.capacity;
02039         switch (old_cid) {
02040           case CT_PASSENGERS: break;
02041           case CT_MAIL:
02042           case CT_GOODS: amount *= 2; break;
02043           default:       amount *= 4; break;
02044         }
02045         switch (new_cid) {
02046           case CT_PASSENGERS: break;
02047           case CT_MAIL:
02048           case CT_GOODS: amount /= 2; break;
02049           default:       amount /= 4; break;
02050         }
02051       }
02052 
02053       if (new_cid != v->cargo_type) {
02054         cost.AddCost(GetRefitCost(v->engine_type));
02055       }
02056 
02057       num += amount;
02058       if (flags & DC_EXEC) {
02059         v->cargo.Truncate((v->cargo_type == new_cid) ? amount : 0);
02060         v->cargo_type = new_cid;
02061         v->cargo_cap = amount;
02062         v->cargo_subtype = new_subtype;
02063         InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
02064         InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
02065         InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
02066       }
02067     }
02068   } while ((v = v->Next()) != NULL && !only_this);
02069 
02070   _returned_refit_capacity = num;
02071 
02072   /* Update the train's cached variables */
02073   if (flags & DC_EXEC) TrainConsistChanged(GetVehicle(p1)->First(), false);
02074 
02075   return cost;
02076 }
02077 
02078 struct TrainFindDepotData {
02079   uint best_length;
02080   TileIndex tile;
02081   Owner owner;
02086   bool reverse;
02087 };
02088 
02089 static bool NtpCallbFindDepot(TileIndex tile, TrainFindDepotData *tfdd, int track, uint length)
02090 {
02091   if (IsTileType(tile, MP_RAILWAY) &&
02092       IsTileOwner(tile, tfdd->owner) &&
02093       IsRailDepot(tile)) {
02094     /* approximate number of tiles by dividing by DIAG_FACTOR */
02095     tfdd->best_length = length / DIAG_FACTOR;
02096     tfdd->tile = tile;
02097     return true;
02098   }
02099 
02100   return false;
02101 }
02102 
02105 static TrainFindDepotData FindClosestTrainDepot(Vehicle *v, int max_distance)
02106 {
02107   assert(!(v->vehstatus & VS_CRASHED));
02108 
02109   TrainFindDepotData tfdd;
02110   tfdd.owner = v->owner;
02111   tfdd.reverse = false;
02112 
02113   if (IsRailDepotTile(v->tile)) {
02114     tfdd.tile = v->tile;
02115     tfdd.best_length = 0;
02116     return tfdd;
02117   }
02118 
02119   PBSTileInfo origin = FollowTrainReservation(v);
02120   if (IsRailDepotTile(origin.tile)) {
02121     tfdd.tile = origin.tile;
02122     tfdd.best_length = 0;
02123     return tfdd;
02124   }
02125 
02126   tfdd.best_length = UINT_MAX;
02127 
02128   uint8 pathfinder = _settings_game.pf.pathfinder_for_trains;
02129   if ((_settings_game.pf.reserve_paths || HasReservedTracks(v->tile, v->u.rail.track)) && pathfinder == VPF_NTP) pathfinder = VPF_NPF;
02130 
02131   switch (pathfinder) {
02132     case VPF_YAPF: { // YAPF
02133       bool found = YapfFindNearestRailDepotTwoWay(v, max_distance, NPF_INFINITE_PENALTY, &tfdd.tile, &tfdd.reverse);
02134       tfdd.best_length = found ? max_distance / 2 : UINT_MAX; // some fake distance or NOT_FOUND
02135     } break;
02136 
02137     case VPF_NPF: { // NPF
02138       const Vehicle *last = GetLastVehicleInChain(v);
02139       Trackdir trackdir = GetVehicleTrackdir(v);
02140       Trackdir trackdir_rev = ReverseTrackdir(GetVehicleTrackdir(last));
02141 
02142       assert(trackdir != INVALID_TRACKDIR);
02143       NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes, NPF_INFINITE_PENALTY);
02144       if (ftd.best_bird_dist == 0) {
02145         /* Found target */
02146         tfdd.tile = ftd.node.tile;
02147         /* Our caller expects a number of tiles, so we just approximate that
02148          * number by this. It might not be completely what we want, but it will
02149          * work for now :-) We can possibly change this when the old pathfinder
02150          * is removed. */
02151         tfdd.best_length = ftd.best_path_dist / NPF_TILE_LENGTH;
02152         if (NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE)) tfdd.reverse = true;
02153       }
02154     } break;
02155 
02156     default:
02157     case VPF_NTP: { // NTP
02158       /* search in the forward direction first. */
02159       DiagDirection i = TrainExitDir(v->direction, v->u.rail.track);
02160       NewTrainPathfind(v->tile, 0, v->u.rail.compatible_railtypes, i, (NTPEnumProc*)NtpCallbFindDepot, &tfdd);
02161       if (tfdd.best_length == UINT_MAX){
02162         tfdd.reverse = true;
02163         /* search in backwards direction */
02164         i = TrainExitDir(ReverseDir(v->direction), v->u.rail.track);
02165         NewTrainPathfind(v->tile, 0, v->u.rail.compatible_railtypes, i, (NTPEnumProc*)NtpCallbFindDepot, &tfdd);
02166       }
02167     } break;
02168   }
02169 
02170   return tfdd;
02171 }
02172 
02173 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
02174 {
02175   TrainFindDepotData tfdd = FindClosestTrainDepot(this, 0);
02176   if (tfdd.best_length == UINT_MAX) return false;
02177 
02178   if (location    != NULL) *location    = tfdd.tile;
02179   if (destination != NULL) *destination = GetDepotByTile(tfdd.tile)->index;
02180   if (reverse     != NULL) *reverse     = tfdd.reverse;
02181 
02182   return true;
02183 }
02184 
02193 CommandCost CmdSendTrainToDepot(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
02194 {
02195   if (p2 & DEPOT_MASS_SEND) {
02196     /* Mass goto depot requested */
02197     if (!ValidVLWFlags(p2 & VLW_MASK)) return CMD_ERROR;
02198     return SendAllVehiclesToDepot(VEH_TRAIN, flags, p2 & DEPOT_SERVICE, _current_company, (p2 & VLW_MASK), p1);
02199   }
02200 
02201   if (!IsValidVehicleID(p1)) return CMD_ERROR;
02202 
02203   Vehicle *v = GetVehicle(p1);
02204 
02205   if (v->type != VEH_TRAIN) return CMD_ERROR;
02206 
02207   return v->SendToDepot(flags, (DepotCommand)(p2 & DEPOT_COMMAND_MASK));
02208 }
02209 
02210 
02211 void OnTick_Train()
02212 {
02213   _age_cargo_skip_counter = (_age_cargo_skip_counter == 0) ? 184 : (_age_cargo_skip_counter - 1);
02214 }
02215 
02216 static const int8 _vehicle_smoke_pos[8] = {
02217   1, 1, 1, 0, -1, -1, -1, 0
02218 };
02219 
02220 static void HandleLocomotiveSmokeCloud(const Vehicle *v)
02221 {
02222   bool sound = false;
02223 
02224   if (v->vehstatus & VS_TRAIN_SLOWING || v->load_unload_time_rem != 0 || v->cur_speed < 2) {
02225     return;
02226   }
02227 
02228   const Vehicle *u = v;
02229 
02230   do {
02231     const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
02232     int effect_offset = GB(v->u.rail.cached_vis_effect, 0, 4) - 8;
02233     byte effect_type = GB(v->u.rail.cached_vis_effect, 4, 2);
02234     bool disable_effect = HasBit(v->u.rail.cached_vis_effect, 6);
02235 
02236     /* no smoke? */
02237     if ((rvi->railveh_type == RAILVEH_WAGON && effect_type == 0) ||
02238         disable_effect ||
02239         v->vehstatus & VS_HIDDEN) {
02240       continue;
02241     }
02242 
02243     /* No smoke in depots or tunnels */
02244     if (IsRailDepotTile(v->tile) || IsTunnelTile(v->tile)) continue;
02245 
02246     /* No sparks for electric vehicles on nonelectrified tracks */
02247     if (!HasPowerOnRail(v->u.rail.railtype, GetTileRailType(v->tile))) continue;
02248 
02249     if (effect_type == 0) {
02250       /* Use default effect type for engine class. */
02251       effect_type = rvi->engclass;
02252     } else {
02253       effect_type--;
02254     }
02255 
02256     int x = _vehicle_smoke_pos[v->direction] * effect_offset;
02257     int y = _vehicle_smoke_pos[(v->direction + 2) % 8] * effect_offset;
02258 
02259     if (HasBit(v->u.rail.flags, VRF_REVERSE_DIRECTION)) {
02260       x = -x;
02261       y = -y;
02262     }
02263 
02264     switch (effect_type) {
02265       case 0:
02266         /* steam smoke. */
02267         if (GB(v->tick_counter, 0, 4) == 0) {
02268           CreateEffectVehicleRel(v, x, y, 10, EV_STEAM_SMOKE);
02269           sound = true;
02270         }
02271         break;
02272 
02273       case 1:
02274         /* diesel smoke */
02275         if (u->cur_speed <= 40 && Chance16(15, 128)) {
02276           CreateEffectVehicleRel(v, 0, 0, 10, EV_DIESEL_SMOKE);
02277           sound = true;
02278         }
02279         break;
02280 
02281       case 2:
02282         /* blue spark */
02283         if (GB(v->tick_counter, 0, 2) == 0 && Chance16(1, 45)) {
02284           CreateEffectVehicleRel(v, 0, 0, 10, EV_ELECTRIC_SPARK);
02285           sound = true;
02286         }
02287         break;
02288 
02289       default:
02290         break;
02291     }
02292   } while ((v = v->Next()) != NULL);
02293 
02294   if (sound) PlayVehicleSound(u, VSE_TRAIN_EFFECT);
02295 }
02296 
02297 void Train::PlayLeaveStationSound() const
02298 {
02299   static const SoundFx sfx[] = {
02300     SND_04_TRAIN,
02301     SND_0A_TRAIN_HORN,
02302     SND_0A_TRAIN_HORN,
02303     SND_47_MAGLEV_2,
02304     SND_41_MAGLEV
02305   };
02306 
02307   if (PlayVehicleSound(this, VSE_START)) return;
02308 
02309   EngineID engtype = this->engine_type;
02310   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02311 }
02312 
02314 static void CheckNextTrainTile(Vehicle *v)
02315 {
02316   /* Don't do any look-ahead if path_backoff_interval is 255. */
02317   if (_settings_game.pf.path_backoff_interval == 255) return;
02318 
02319   /* Exit if we reached our destination depot or are inside a depot. */
02320   if ((v->tile == v->dest_tile && v->current_order.IsType(OT_GOTO_DEPOT)) || v->u.rail.track & TRACK_BIT_DEPOT) return;
02321   /* Exit if we are on a station tile and are going to stop. */
02322   if (IsRailwayStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02323   /* Exit if the current order doesn't have a destination, but the train has orders. */
02324   if ((v->current_order.IsType(OT_NOTHING) || v->current_order.IsType(OT_LEAVESTATION) || v->current_order.IsType(OT_LOADING)) && v->GetNumOrders() > 0) return;
02325 
02326   Trackdir td = GetVehicleTrackdir(v);
02327 
02328   /* On a tile with a red non-pbs signal, don't look ahead. */
02329   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02330       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02331       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02332 
02333   CFollowTrackRail ft(v);
02334   if (!ft.Follow(v->tile, td)) return;
02335 
02336   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02337     /* Next tile is not reserved. */
02338     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02339       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02340         /* If the next tile is a PBS signal, try to make a reservation. */
02341         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02342         if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
02343           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02344         }
02345         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02346       }
02347     }
02348   }
02349 }
02350 
02351 static bool CheckTrainStayInDepot(Vehicle *v)
02352 {
02353   /* bail out if not all wagons are in the same depot or not in a depot at all */
02354   for (const Vehicle *u = v; u != NULL; u = u->Next()) {
02355     if (u->u.rail.track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02356   }
02357 
02358   /* if the train got no power, then keep it in the depot */
02359   if (v->u.rail.cached_power == 0) {
02360     v->vehstatus |= VS_STOPPED;
02361     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
02362     return true;
02363   }
02364 
02365   SigSegState seg_state;
02366 
02367   if (v->u.rail.force_proceed == 0) {
02368     /* force proceed was not pressed */
02369     if (++v->load_unload_time_rem < 37) {
02370       InvalidateWindowClasses(WC_TRAINS_LIST);
02371       return true;
02372     }
02373 
02374     v->load_unload_time_rem = 0;
02375 
02376     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02377     if (seg_state == SIGSEG_FULL || GetDepotWaypointReservation(v->tile)) {
02378       /* Full and no PBS signal in block or depot reserved, can't exit. */
02379       InvalidateWindowClasses(WC_TRAINS_LIST);
02380       return true;
02381     }
02382   } else {
02383     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02384   }
02385 
02386   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02387   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02388     /* We need to have a reservation for this to work. */
02389     if (GetDepotWaypointReservation(v->tile)) return true;
02390     SetDepotWaypointReservation(v->tile, true);
02391     VehicleEnterDepot(v);
02392     return true;
02393   }
02394 
02395   /* Only leave when we can reserve a path to our destination. */
02396   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->u.rail.force_proceed == 0) {
02397     /* No path and no force proceed. */
02398     InvalidateWindowClasses(WC_TRAINS_LIST);
02399     MarkTrainAsStuck(v);
02400     return true;
02401   }
02402 
02403   SetDepotWaypointReservation(v->tile, true);
02404   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02405 
02406   VehicleServiceInDepot(v);
02407   InvalidateWindowClasses(WC_TRAINS_LIST);
02408   v->PlayLeaveStationSound();
02409 
02410   v->u.rail.track = TRACK_BIT_X;
02411   if (v->direction & 2) v->u.rail.track = TRACK_BIT_Y;
02412 
02413   v->vehstatus &= ~VS_HIDDEN;
02414   v->cur_speed = 0;
02415 
02416   v->UpdateDeltaXY(v->direction);
02417   v->cur_image = v->GetImage(v->direction);
02418   VehicleMove(v, false);
02419   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02420   UpdateTrainAcceleration(v);
02421   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02422 
02423   return false;
02424 }
02425 
02427 static void ClearPathReservation(const Vehicle *v, TileIndex tile, Trackdir track_dir)
02428 {
02429   DiagDirection dir = TrackdirToExitdir(track_dir);
02430 
02431   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02432     /* Are we just leaving a tunnel/bridge? */
02433     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02434       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02435 
02436       if (!HasVehicleOnTunnelBridge(tile, end, v)) {
02437         /* Free the reservation only if no other train is on the tiles. */
02438         SetTunnelBridgeReservation(tile, false);
02439         SetTunnelBridgeReservation(end, false);
02440 
02441         if (_settings_client.gui.show_track_reservation) {
02442           MarkTileDirtyByTile(tile);
02443           MarkTileDirtyByTile(end);
02444         }
02445       }
02446     }
02447   } else if (IsRailwayStationTile(tile)) {
02448     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02449     /* If the new tile is not a further tile of the same station, we
02450      * clear the reservation for the whole platform. */
02451     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02452       SetRailwayStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02453     }
02454   } else {
02455     /* Any other tile */
02456     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02457   }
02458 }
02459 
02461 void FreeTrainTrackReservation(const Vehicle *v, TileIndex origin, Trackdir orig_td)
02462 {
02463   assert(IsFrontEngine(v));
02464 
02465   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02466   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : GetVehicleTrackdir(v);
02467   bool      free_tile = tile != v->tile || !(IsRailwayStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02468   StationID station_id = IsRailwayStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02469 
02470   /* Don't free reservation if it's not ours. */
02471   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02472 
02473   CFollowTrackRail ft(v, GetRailTypeInfo(v->u.rail.railtype)->compatible_railtypes);
02474   while (ft.Follow(tile, td)) {
02475     tile = ft.m_new_tile;
02476     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02477     td = RemoveFirstTrackdir(&bits);
02478     assert(bits == TRACKDIR_BIT_NONE);
02479 
02480     if (!IsValidTrackdir(td)) break;
02481 
02482     if (IsTileType(tile, MP_RAILWAY)) {
02483       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02484         /* Conventional signal along trackdir: remove reservation and stop. */
02485         UnreserveRailTrack(tile, TrackdirToTrack(td));
02486         break;
02487       }
02488       if (HasPbsSignalOnTrackdir(tile, td)) {
02489         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02490           /* Red PBS signal? Can't be our reservation, would be green then. */
02491           break;
02492         } else {
02493           /* Turn the signal back to red. */
02494           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02495           MarkTileDirtyByTile(tile);
02496         }
02497       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02498         break;
02499       }
02500     }
02501 
02502     /* Don't free first station/bridge/tunnel if we are on it. */
02503     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);
02504 
02505     free_tile = true;
02506   }
02507 }
02508 
02510 struct TrainTrackFollowerData {
02511   TileIndex dest_coords;
02512   StationID station_index; 
02513   uint best_bird_dist;
02514   uint best_track_dist;
02515   TrackdirByte best_track;
02516 };
02517 
02518 static bool NtpCallbFindStation(TileIndex tile, TrainTrackFollowerData *ttfd, Trackdir track, uint length)
02519 {
02520   /* heading for nowhere? */
02521   if (ttfd->dest_coords == 0) return false;
02522 
02523   /* did we reach the final station? */
02524   if ((ttfd->station_index == INVALID_STATION && tile == ttfd->dest_coords) || (
02525         IsTileType(tile, MP_STATION) &&
02526         IsRailwayStation(tile) &&
02527         GetStationIndex(tile) == ttfd->station_index
02528       )) {
02529     /* We do not check for dest_coords if we have a station_index,
02530      * because in that case the dest_coords are just an
02531      * approximation of where the station is */
02532 
02533     /* found station */
02534     ttfd->best_track = track;
02535     ttfd->best_bird_dist = 0;
02536     return true;
02537   } else {
02538     /* didn't find station, keep track of the best path so far. */
02539     uint dist = DistanceManhattan(tile, ttfd->dest_coords);
02540     if (dist < ttfd->best_bird_dist) {
02541       ttfd->best_bird_dist = dist;
02542       ttfd->best_track = track;
02543     }
02544     return false;
02545   }
02546 }
02547 
02548 static void FillWithStationData(TrainTrackFollowerData *fd, const Vehicle *v)
02549 {
02550   fd->dest_coords = v->dest_tile;
02551   fd->station_index = v->current_order.IsType(OT_GOTO_STATION) ? v->current_order.GetDestination() : INVALID_STATION;
02552 }
02553 
02554 static const byte _initial_tile_subcoord[6][4][3] = {
02555 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02556 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02557 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02558 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02559 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02560 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02561 };
02562 
02563 static const byte _search_directions[6][4] = {
02564   { 0, 9, 2, 9 }, 
02565   { 9, 1, 9, 3 }, 
02566   { 9, 0, 3, 9 }, 
02567   { 1, 9, 9, 2 }, 
02568   { 3, 2, 9, 9 }, 
02569   { 9, 9, 1, 0 }, 
02570 };
02571 
02572 static const byte _pick_track_table[6] = {1, 3, 2, 2, 0, 0};
02573 
02586 static Track DoTrainPathfind(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool do_track_reservation, PBSTileInfo *dest)
02587 {
02588   Track best_track;
02589 
02590 #ifdef PF_BENCHMARK
02591   TIC()
02592 #endif
02593 
02594   if (path_not_found) *path_not_found = false;
02595 
02596   uint8 pathfinder = _settings_game.pf.pathfinder_for_trains;
02597   if (do_track_reservation && pathfinder == VPF_NTP) pathfinder = VPF_NPF;
02598 
02599   switch (pathfinder) {
02600     case VPF_YAPF: { // YAPF
02601       Trackdir trackdir = YapfChooseRailTrack(v, tile, enterdir, tracks, path_not_found, do_track_reservation, dest);
02602       if (trackdir != INVALID_TRACKDIR) {
02603         best_track = TrackdirToTrack(trackdir);
02604       } else {
02605         best_track = FindFirstTrack(tracks);
02606       }
02607     } break;
02608 
02609     case VPF_NPF: { // NPF
02610       void *perf = NpfBeginInterval();
02611 
02612       NPFFindStationOrTileData fstd;
02613       NPFFillWithOrderData(&fstd, v, do_track_reservation);
02614 
02615       PBSTileInfo origin = FollowTrainReservation(v);
02616       assert(IsValidTrackdir(origin.trackdir));
02617 
02618       NPFFoundTargetData ftd = NPFRouteToStationOrTile(origin.tile, origin.trackdir, true, &fstd, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes);
02619 
02620       if (dest != NULL) {
02621         dest->tile = ftd.node.tile;
02622         dest->trackdir = (Trackdir)ftd.node.direction;
02623         dest->okay = ftd.res_okay;
02624       }
02625 
02626       if (ftd.best_trackdir == INVALID_TRACKDIR) {
02627         /* We are already at our target. Just do something
02628          * @todo maybe display error?
02629          * @todo: go straight ahead if possible? */
02630         best_track = FindFirstTrack(tracks);
02631       } else {
02632         /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
02633          * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
02634          * we did not find our target, but ftd.best_trackdir contains the direction leading
02635          * to the tile closest to our target. */
02636         if (ftd.best_bird_dist != 0 && path_not_found != NULL) *path_not_found = true;
02637         /* Discard enterdir information, making it a normal track */
02638         best_track = TrackdirToTrack(ftd.best_trackdir);
02639       }
02640 
02641       int time = NpfEndInterval(perf);
02642       DEBUG(yapf, 4, "[NPFT] %d us - %d rounds - %d open - %d closed -- ", time, 0, _aystar_stats_open_size, _aystar_stats_closed_size);
02643     } break;
02644 
02645     default:
02646     case VPF_NTP: { // NTP
02647       void *perf = NpfBeginInterval();
02648 
02649       TrainTrackFollowerData fd;
02650       FillWithStationData(&fd, v);
02651 
02652       /* New train pathfinding */
02653       fd.best_bird_dist = UINT_MAX;
02654       fd.best_track_dist = UINT_MAX;
02655       fd.best_track = INVALID_TRACKDIR;
02656 
02657       NewTrainPathfind(tile - TileOffsByDiagDir(enterdir), v->dest_tile,
02658         v->u.rail.compatible_railtypes, enterdir, (NTPEnumProc*)NtpCallbFindStation, &fd);
02659 
02660       /* check whether the path was found or only 'guessed' */
02661       if (fd.best_bird_dist != 0 && path_not_found != NULL) *path_not_found = true;
02662 
02663       if (fd.best_track == INVALID_TRACKDIR) {
02664         /* blaha */
02665         best_track = FindFirstTrack(tracks);
02666       } else {
02667         best_track = TrackdirToTrack(fd.best_track);
02668       }
02669 
02670       int time = NpfEndInterval(perf);
02671       DEBUG(yapf, 4, "[NTPT] %d us - %d rounds - %d open - %d closed -- ", time, 0, 0, 0);
02672     } break;
02673   }
02674 
02675 #ifdef PF_BENCHMARK
02676   TOC("PF time = ", 1)
02677 #endif
02678 
02679   return best_track;
02680 }
02681 
02687 static PBSTileInfo ExtendTrainReservation(const Vehicle *v, TrackBits *new_tracks, DiagDirection *enterdir)
02688 {
02689   bool no_90deg_turns = _settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg;
02690   PBSTileInfo origin = FollowTrainReservation(v);
02691 
02692   CFollowTrackRail ft(v);
02693 
02694   TileIndex tile = origin.tile;
02695   Trackdir  cur_td = origin.trackdir;
02696   while (ft.Follow(tile, cur_td)) {
02697     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02698       /* Possible signal tile. */
02699       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02700     }
02701 
02702     if (no_90deg_turns) {
02703       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02704       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02705     }
02706 
02707     /* Station, depot or waypoint are a possible target. */
02708     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02709     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02710       /* Choice found or possible target encountered.
02711        * On finding a possible target, we need to stop and let the pathfinder handle the
02712        * remaining path. This is because we don't know if this target is in one of our
02713        * orders, so we might cause pathfinding to fail later on if we find a choice.
02714        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02715        * a wrong path not leading to our next destination. */
02716       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02717 
02718       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02719        * actually starts its search at the first unreserved tile. */
02720       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02721 
02722       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02723       if (new_tracks) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02724       if (enterdir) *enterdir = ft.m_exitdir;
02725       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02726     }
02727 
02728     tile = ft.m_new_tile;
02729     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02730 
02731     if (IsSafeWaitingPosition(v, tile, cur_td, true, no_90deg_turns)) {
02732       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, no_90deg_turns);
02733       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02734       /* Safe position is all good, path valid and okay. */
02735       return PBSTileInfo(tile, cur_td, true);
02736     }
02737 
02738     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02739   }
02740 
02741   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02742     /* End of line, path valid and okay. */
02743     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02744   }
02745 
02746   /* Sorry, can't reserve path, back out. */
02747   tile = origin.tile;
02748   cur_td = origin.trackdir;
02749   TileIndex stopped = ft.m_old_tile;
02750   Trackdir  stopped_td = ft.m_old_td;
02751   while (tile != stopped || cur_td != stopped_td) {
02752     if (!ft.Follow(tile, cur_td)) break;
02753 
02754     if (no_90deg_turns) {
02755       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02756       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02757     }
02758     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02759 
02760     tile = ft.m_new_tile;
02761     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02762 
02763     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02764   }
02765 
02766   /* Path invalid. */
02767   return PBSTileInfo();
02768 }
02769 
02780 static bool TryReserveSafeTrack(const Vehicle *v, TileIndex tile, Trackdir td, bool override_tailtype)
02781 {
02782   if (_settings_game.pf.pathfinder_for_trains == VPF_YAPF) {
02783     return YapfRailFindNearestSafeTile(v, tile, td, override_tailtype);
02784   } else {
02785     return NPFRouteToSafeTile(v, tile, td, override_tailtype).res_okay;
02786   }
02787 }
02788 
02790 class VehicleOrderSaver
02791 {
02792 private:
02793   Vehicle        *v;
02794   Order          old_order;
02795   TileIndex      old_dest_tile;
02796   StationID      old_last_station_visited;
02797   VehicleOrderID index;
02798 
02799 public:
02800   VehicleOrderSaver(Vehicle *_v) :
02801     v(_v),
02802     old_order(_v->current_order),
02803     old_dest_tile(_v->dest_tile),
02804     old_last_station_visited(_v->last_station_visited),
02805     index(_v->cur_order_index)
02806   {
02807   }
02808 
02809   ~VehicleOrderSaver()
02810   {
02811     this->v->current_order = this->old_order;
02812     this->v->dest_tile = this->old_dest_tile;
02813     this->v->last_station_visited = this->old_last_station_visited;
02814   }
02815 
02821   bool SwitchToNextOrder(bool skip_first)
02822   {
02823     if (this->v->GetNumOrders() == 0) return false;
02824 
02825     if (skip_first) ++this->index;
02826 
02827     int conditional_depth = 0;
02828 
02829     do {
02830       /* Wrap around. */
02831       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02832 
02833       Order *order = GetVehicleOrder(this->v, this->index);
02834       assert(order != NULL);
02835 
02836       switch (order->GetType()) {
02837         case OT_GOTO_DEPOT:
02838           /* Skip service in depot orders when the train doesn't need service. */
02839           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02840         case OT_GOTO_STATION:
02841         case OT_GOTO_WAYPOINT:
02842           this->v->current_order = *order;
02843           UpdateOrderDest(this->v, order);
02844           return true;
02845         case OT_CONDITIONAL: {
02846           if (conditional_depth > this->v->GetNumOrders()) return false;
02847           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02848           if (next != INVALID_VEH_ORDER_ID) {
02849             conditional_depth++;
02850             this->index = next;
02851             /* Don't increment next, so no break here. */
02852             continue;
02853           }
02854           break;
02855         }
02856         default:
02857           break;
02858       }
02859       /* Don't increment inside the while because otherwise conditional
02860        * orders can lead to an infinite loop. */
02861       ++this->index;
02862     } while (this->index != this->v->cur_order_index);
02863 
02864     return false;
02865   }
02866 };
02867 
02868 /* choose a track */
02869 static Track ChooseTrainTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02870 {
02871   Track best_track = INVALID_TRACK;
02872   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02873   bool changed_signal = false;
02874 
02875   assert((tracks & ~TRACK_BIT_MASK) == 0);
02876 
02877   if (got_reservation != NULL) *got_reservation = false;
02878 
02879   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02880   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02881   /* Do we have a suitable reserved track? */
02882   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02883 
02884   /* Quick return in case only one possible track is available */
02885   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02886     Track track = FindFirstTrack(tracks);
02887     /* We need to check for signals only here, as a junction tile can't have signals. */
02888     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02889       do_track_reservation = true;
02890       changed_signal = true;
02891       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02892     } else if (!do_track_reservation) {
02893       return track;
02894     }
02895     best_track = track;
02896   }
02897 
02898   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02899   DiagDirection dest_enterdir = enterdir;
02900   if (do_track_reservation) {
02901     /* Check if the train needs service here, so it has a chance to always find a depot.
02902      * Also check if the current order is a service order so we don't reserve a path to
02903      * the destination but instead to the next one if service isn't needed. */
02904     CheckIfTrainNeedsService(v);
02905     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02906 
02907     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02908     if (res_dest.tile == INVALID_TILE) {
02909       /* Reservation failed? */
02910       if (mark_stuck) MarkTrainAsStuck(v);
02911       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02912       return FindFirstTrack(tracks);
02913     }
02914   }
02915 
02916   /* Save the current train order. The destructor will restore the old order on function exit. */
02917   VehicleOrderSaver orders(v);
02918 
02919   /* If the current tile is the destination of the current order and
02920    * a reservation was requested, advance to the next order.
02921    * Don't advance on a depot order as depots are always safe end points
02922    * for a path and no look-ahead is necessary. This also avoids a
02923    * problem with depot orders not part of the order list when the
02924    * order list itself is empty. */
02925   if (v->current_order.IsType(OT_LEAVESTATION)) {
02926     orders.SwitchToNextOrder(false);
02927   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02928       v->current_order.IsType(OT_GOTO_STATION) ?
02929       IsRailwayStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02930       v->tile == v->dest_tile))) {
02931     orders.SwitchToNextOrder(true);
02932   }
02933 
02934   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02935     /* Pathfinders are able to tell that route was only 'guessed'. */
02936     bool      path_not_found = false;
02937     TileIndex new_tile = res_dest.tile;
02938 
02939     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, &path_not_found, do_track_reservation, &res_dest);
02940     if (new_tile == tile) best_track = next_track;
02941 
02942     /* handle "path not found" state */
02943     if (path_not_found) {
02944       /* PF didn't find the route */
02945       if (!HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
02946         /* it is first time the problem occurred, set the "path not found" flag */
02947         SetBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
02948         /* and notify user about the event */
02949         AI::NewEvent(v->owner, new AIEventVehicleLost(v->index));
02950         if (_settings_client.gui.lost_train_warn && v->owner == _local_company) {
02951           SetDParam(0, v->index);
02952           AddNewsItem(
02953             STR_TRAIN_IS_LOST,
02954             NS_ADVICE,
02955             v->index,
02956             0);
02957         }
02958       }
02959     } else {
02960       /* route found, is the train marked with "path not found" flag? */
02961       if (HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
02962         /* clear the flag as the PF's problem was solved */
02963         ClrBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
02964         /* can we also delete the "News" item somehow? */
02965       }
02966     }
02967   }
02968 
02969   /* No track reservation requested -> finished. */
02970   if (!do_track_reservation) return best_track;
02971 
02972   /* A path was found, but could not be reserved. */
02973   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02974     if (mark_stuck) MarkTrainAsStuck(v);
02975     FreeTrainTrackReservation(v);
02976     return best_track;
02977   }
02978 
02979   /* No possible reservation target found, we are probably lost. */
02980   if (res_dest.tile == INVALID_TILE) {
02981     /* Try to find any safe destination. */
02982     PBSTileInfo origin = FollowTrainReservation(v);
02983     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02984       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02985       best_track = FindFirstTrack(res);
02986       TryReserveRailTrack(v->tile, TrackdirToTrack(GetVehicleTrackdir(v)));
02987       if (got_reservation != NULL) *got_reservation = true;
02988       if (changed_signal) MarkTileDirtyByTile(tile);
02989     } else {
02990       FreeTrainTrackReservation(v);
02991       if (mark_stuck) MarkTrainAsStuck(v);
02992     }
02993     return best_track;
02994   }
02995 
02996   if (got_reservation != NULL) *got_reservation = true;
02997 
02998   /* Reservation target found and free, check if it is safe. */
02999   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
03000     /* Extend reservation until we have found a safe position. */
03001     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
03002     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
03003     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
03004     if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
03005       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
03006     }
03007 
03008     /* Get next order with destination. */
03009     if (orders.SwitchToNextOrder(true)) {
03010       PBSTileInfo cur_dest;
03011       DoTrainPathfind(v, next_tile, exitdir, reachable, NULL, true, &cur_dest);
03012       if (cur_dest.tile != INVALID_TILE) {
03013         res_dest = cur_dest;
03014         if (res_dest.okay) continue;
03015         /* Path found, but could not be reserved. */
03016         FreeTrainTrackReservation(v);
03017         if (mark_stuck) MarkTrainAsStuck(v);
03018         if (got_reservation != NULL) *got_reservation = false;
03019         changed_signal = false;
03020         break;
03021       }
03022     }
03023     /* No order or no safe position found, try any position. */
03024     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
03025       FreeTrainTrackReservation(v);
03026       if (mark_stuck) MarkTrainAsStuck(v);
03027       if (got_reservation != NULL) *got_reservation = false;
03028       changed_signal = false;
03029     }
03030     break;
03031   }
03032 
03033   TryReserveRailTrack(v->tile, TrackdirToTrack(GetVehicleTrackdir(v)));
03034 
03035   if (changed_signal) MarkTileDirtyByTile(tile);
03036 
03037   return best_track;
03038 }
03039 
03048 bool TryPathReserve(Vehicle *v, bool mark_as_stuck, bool first_tile_okay)
03049 {
03050   assert(v->type == VEH_TRAIN && IsFrontEngine(v));
03051 
03052   /* We have to handle depots specially as the track follower won't look
03053    * at the depot tile itself but starts from the next tile. If we are still
03054    * inside the depot, a depot reservation can never be ours. */
03055   if (v->u.rail.track & TRACK_BIT_DEPOT) {
03056     if (GetDepotWaypointReservation(v->tile)) {
03057       if (mark_as_stuck) MarkTrainAsStuck(v);
03058       return false;
03059     } else {
03060       /* Depot not reserved, but the next tile might be. */
03061       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
03062       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
03063     }
03064   }
03065 
03066   /* Special check if we are in front of a two-sided conventional signal. */
03067   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
03068   TileIndex next_tile = TileAddByDiagDir(v->tile, dir);
03069   if (IsTileType(next_tile, MP_RAILWAY) && HasReservedTracks(next_tile, DiagdirReachesTracks(dir))) {
03070     /* Can have only one reserved trackdir. */
03071     Trackdir td = FindFirstTrackdir(TrackBitsToTrackdirBits(GetReservedTrackbits(next_tile)) & DiagdirReachesTrackdirs(dir));
03072     if (HasSignalOnTrackdir(next_tile, td) && HasSignalOnTrackdir(next_tile, ReverseTrackdir(td)) &&
03073         !IsPbsSignal(GetSignalType(next_tile, TrackdirToTrack(td)))) {
03074       /* Signal already reserved, is not ours. */
03075       if (mark_as_stuck) MarkTrainAsStuck(v);
03076       return false;
03077     }
03078   }
03079 
03080   bool other_train = false;
03081   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
03082   /* The path we are driving on is alread blocked by some other train.
03083    * This can only happen in certain situations when mixing path and
03084    * block signals or when changing tracks and/or signals.
03085    * Exit here as doing any further reservations will probably just
03086    * make matters worse. */
03087   if (other_train && v->tile != origin.tile) {
03088     if (mark_as_stuck) MarkTrainAsStuck(v);
03089     return false;
03090   }
03091   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
03092   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
03093     /* Can't be stuck then. */
03094     if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03095     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
03096     return true;
03097   }
03098 
03099   /* If we are in a depot, tentativly reserve the depot. */
03100   if (v->u.rail.track & TRACK_BIT_DEPOT) {
03101     SetDepotWaypointReservation(v->tile, true);
03102     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
03103   }
03104 
03105   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
03106   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
03107   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
03108 
03109   if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
03110 
03111   bool res_made = false;
03112   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
03113 
03114   if (!res_made) {
03115     /* Free the depot reservation as well. */
03116     if (v->u.rail.track & TRACK_BIT_DEPOT) SetDepotWaypointReservation(v->tile, false);
03117     return false;
03118   }
03119 
03120   if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
03121     v->load_unload_time_rem = 0;
03122     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03123   }
03124   ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
03125   return true;
03126 }
03127 
03128 
03129 static bool CheckReverseTrain(Vehicle *v)
03130 {
03131   if (_settings_game.difficulty.line_reverse_mode != 0 ||
03132       v->u.rail.track == TRACK_BIT_DEPOT || v->u.rail.track == TRACK_BIT_WORMHOLE ||
03133       !(v->direction & 1)) {
03134     return false;
03135   }
03136 
03137   uint reverse_best = 0;
03138 
03139   assert(v->u.rail.track);
03140 
03141   switch (_settings_game.pf.pathfinder_for_trains) {
03142     case VPF_YAPF: // YAPF
03143       reverse_best = YapfCheckReverseTrain(v);
03144       break;
03145 
03146     case VPF_NPF: { // NPF
03147       NPFFindStationOrTileData fstd;
03148       NPFFoundTargetData ftd;
03149       Vehicle *last = GetLastVehicleInChain(v);
03150 
03151       NPFFillWithOrderData(&fstd, v);
03152 
03153       Trackdir trackdir = GetVehicleTrackdir(v);
03154       Trackdir trackdir_rev = ReverseTrackdir(GetVehicleTrackdir(last));
03155       assert(trackdir != INVALID_TRACKDIR);
03156       assert(trackdir_rev != INVALID_TRACKDIR);
03157 
03158       ftd = NPFRouteToStationOrTileTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, &fstd, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes);
03159       if (ftd.best_bird_dist != 0) {
03160         /* We didn't find anything, just keep on going straight ahead */
03161         reverse_best = false;
03162       } else {
03163         if (NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE)) {
03164           reverse_best = true;
03165         } else {
03166           reverse_best = false;
03167         }
03168       }
03169     } break;
03170 
03171     default:
03172     case VPF_NTP: { // NTP
03173       TrainTrackFollowerData fd;
03174       FillWithStationData(&fd, v);
03175 
03176       int i = _search_directions[FindFirstTrack(v->u.rail.track)][DirToDiagDir(v->direction)];
03177 
03178       int best_track = -1;
03179       uint reverse = 0;
03180       uint best_bird_dist  = 0;
03181       uint best_track_dist = 0;
03182 
03183       for (;;) {
03184         fd.best_bird_dist = UINT_MAX;
03185         fd.best_track_dist = UINT_MAX;
03186 
03187         NewTrainPathfind(v->tile, v->dest_tile, v->u.rail.compatible_railtypes, (DiagDirection)(reverse ^ i), (NTPEnumProc*)NtpCallbFindStation, &fd);
03188 
03189         if (best_track != -1) {
03190           if (best_bird_dist != 0) {
03191             if (fd.best_bird_dist != 0) {
03192               /* neither reached the destination, pick the one with the smallest bird dist */
03193               if (fd.best_bird_dist > best_bird_dist) goto bad;
03194               if (fd.best_bird_dist < best_bird_dist) goto good;
03195             } else {
03196               /* we found the destination for the first time */
03197               goto good;
03198             }
03199           } else {
03200             if (fd.best_bird_dist != 0) {
03201               /* didn't find destination, but we've found the destination previously */
03202               goto bad;
03203             } else {
03204               /* both old & new reached the destination, compare track length */
03205               if (fd.best_track_dist > best_track_dist) goto bad;
03206               if (fd.best_track_dist < best_track_dist) goto good;
03207             }
03208           }
03209 
03210           /* if we reach this position, there's two paths of equal value so far.
03211            * pick one randomly. */
03212           int r = GB(Random(), 0, 8);
03213           if (_pick_track_table[i] == (v->direction & 3)) r += 80;
03214           if (_pick_track_table[best_track] == (v->direction & 3)) r -= 80;
03215           if (r <= 127) goto bad;
03216         }
03217 good:;
03218         best_track = i;
03219         best_bird_dist = fd.best_bird_dist;
03220         best_track_dist = fd.best_track_dist;
03221         reverse_best = reverse;
03222 bad:;
03223         if (reverse != 0) break;
03224         reverse = 2;
03225       }
03226     } break;
03227   }
03228 
03229   return reverse_best != 0;
03230 }
03231 
03232 TileIndex Train::GetOrderStationLocation(StationID station)
03233 {
03234   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
03235 
03236   const Station *st = GetStation(station);
03237   if (!(st->facilities & FACIL_TRAIN)) {
03238     /* The destination station has no trainstation tiles. */
03239     this->cur_order_index++;
03240     return 0;
03241   }
03242 
03243   return st->xy;
03244 }
03245 
03246 void Train::MarkDirty()
03247 {
03248   Vehicle *v = this;
03249   do {
03250     v->UpdateViewport(false, false);
03251   } while ((v = v->Next()) != NULL);
03252 
03253   /* need to update acceleration and cached values since the goods on the train changed. */
03254   TrainCargoChanged(this);
03255   UpdateTrainAcceleration(this);
03256 }
03257 
03268 static int UpdateTrainSpeed(Vehicle *v)
03269 {
03270   uint accel;
03271 
03272   if (v->vehstatus & VS_STOPPED || HasBit(v->u.rail.flags, VRF_REVERSING) || HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
03273     switch (_settings_game.vehicle.train_acceleration_model) {
03274       default: NOT_REACHED();
03275       case TAM_ORIGINAL:  accel = v->acceleration * -4; break;
03276       case TAM_REALISTIC: accel = GetTrainAcceleration(v, AM_BRAKE); break;
03277     }
03278   } else {
03279     switch (_settings_game.vehicle.train_acceleration_model) {
03280       default: NOT_REACHED();
03281       case TAM_ORIGINAL:  accel = v->acceleration * 2; break;
03282       case TAM_REALISTIC: accel = GetTrainAcceleration(v, AM_ACCEL); break;
03283     }
03284   }
03285 
03286   uint spd = v->subspeed + accel;
03287   v->subspeed = (byte)spd;
03288   {
03289     int tempmax = v->max_speed;
03290     if (v->cur_speed > v->max_speed)
03291       tempmax = v->cur_speed - (v->cur_speed / 10) - 1;
03292     v->cur_speed = spd = Clamp(v->cur_speed + ((int)spd >> 8), 0, tempmax);
03293   }
03294 
03295   /* Scale speed by 3/4. Previously this was only done when the train was
03296    * facing diagonally and would apply to however many moves the train made
03297    * regardless the of direction actually moved in. Now it is always scaled,
03298    * 256 spd is used to go straight and 192 is used to go diagonally
03299    * (3/4 of 256). This results in the same effect, but without the error the
03300    * previous method caused.
03301    *
03302    * The scaling is done in this direction and not by multiplying the amount
03303    * to be subtracted by 4/3 so that the leftover speed can be saved in a
03304    * byte in v->progress.
03305    */
03306   int scaled_spd = spd * 3 >> 2;
03307 
03308   scaled_spd += v->progress;
03309   v->progress = 0; // set later in TrainLocoHandler or TrainController
03310   return scaled_spd;
03311 }
03312 
03313 static void TrainEnterStation(Vehicle *v, StationID station)
03314 {
03315   v->last_station_visited = station;
03316 
03317   /* check if a train ever visited this station before */
03318   Station *st = GetStation(station);
03319   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
03320     st->had_vehicle_of_type |= HVOT_TRAIN;
03321     SetDParam(0, st->index);
03322     AddNewsItem(
03323       STR_8801_CITIZENS_CELEBRATE_FIRST,
03324       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
03325       v->index,
03326       st->index
03327     );
03328     AI::NewEvent(v->owner, new AIEventStationFirstVehicle(st->index, v->index));
03329   }
03330 
03331   v->BeginLoading();
03332 
03333   StationAnimationTrigger(st, v->tile, STAT_ANIM_TRAIN_ARRIVES);
03334 }
03335 
03336 static byte AfterSetTrainPos(Vehicle *v, bool new_tile)
03337 {
03338   byte old_z = v->z_pos;
03339   v->z_pos = GetSlopeZ(v->x_pos, v->y_pos);
03340 
03341   if (new_tile) {
03342     ClrBit(v->u.rail.flags, VRF_GOINGUP);
03343     ClrBit(v->u.rail.flags, VRF_GOINGDOWN);
03344 
03345     if (v->u.rail.track == TRACK_BIT_X || v->u.rail.track == TRACK_BIT_Y) {
03346       /* Any track that isn't TRACK_BIT_X or TRACK_BIT_Y cannot be sloped.
03347        * To check whether the current tile is sloped, and in which
03348        * direction it is sloped, we get the 'z' at the center of
03349        * the tile (middle_z) and the edge of the tile (old_z),
03350        * which we then can compare. */
03351       static const int HALF_TILE_SIZE = TILE_SIZE / 2;
03352       static const int INV_TILE_SIZE_MASK = ~(TILE_SIZE - 1);
03353 
03354       byte middle_z = GetSlopeZ((v->x_pos & INV_TILE_SIZE_MASK) | HALF_TILE_SIZE, (v->y_pos & INV_TILE_SIZE_MASK) | HALF_TILE_SIZE);
03355 
03356       /* For some reason tunnel tiles are always given as sloped :(
03357        * But they are not sloped... */
03358       if (middle_z != v->z_pos && !IsTunnelTile(TileVirtXY(v->x_pos, v->y_pos))) {
03359         SetBit(v->u.rail.flags, (middle_z > old_z) ? VRF_GOINGUP : VRF_GOINGDOWN);
03360       }
03361     }
03362   }
03363 
03364   VehicleMove(v, true);
03365   return old_z;
03366 }
03367 
03368 static const Direction _new_vehicle_direction_table[11] = {
03369   DIR_N , DIR_NW, DIR_W , INVALID_DIR,
03370   DIR_NE, DIR_N , DIR_SW, INVALID_DIR,
03371   DIR_E , DIR_SE, DIR_S
03372 };
03373 
03374 static inline Direction GetNewVehicleDirectionByTile(TileIndex new_tile, TileIndex old_tile)
03375 {
03376   uint offs = (TileY(new_tile) - TileY(old_tile) + 1) * 4 +
03377               TileX(new_tile) - TileX(old_tile) + 1;
03378   assert(offs < 11);
03379   return _new_vehicle_direction_table[offs];
03380 }
03381 
03382 static inline int GetDirectionToVehicle(const Vehicle *v, int x, int y)
03383 {
03384   byte offs;
03385 
03386   x -= v->x_pos;
03387   if (x >= 0) {
03388     offs = (x > 2) ? 0 : 1;
03389   } else {
03390     offs = (x < -2) ? 2 : 1;
03391   }
03392 
03393   y -= v->y_pos;
03394   if (y >= 0) {
03395     offs += ((y > 2) ? 0 : 1) * 4;
03396   } else {
03397     offs += ((y < -2) ? 2 : 1) * 4;
03398   }
03399 
03400   assert(offs < 11);
03401   return _new_vehicle_direction_table[offs];
03402 }
03403 
03404 /* Check if the vehicle is compatible with the specified tile */
03405 static inline bool CheckCompatibleRail(const Vehicle *v, TileIndex tile)
03406 {
03407   return
03408     IsTileOwner(tile, v->owner) && (
03409       !IsFrontEngine(v) ||
03410       HasBit(v->u.rail.compatible_railtypes, GetRailType(tile))
03411     );
03412 }
03413 
03414 struct RailtypeSlowdownParams {
03415   byte small_turn, large_turn;
03416   byte z_up; // fraction to remove when moving up
03417   byte z_down; // fraction to remove when moving down
03418 };
03419 
03420 static const RailtypeSlowdownParams _railtype_slowdown[] = {
03421   /* normal accel */
03422   {256 / 4, 256 / 2, 256 / 4, 2}, 
03423   {256 / 4, 256 / 2, 256 / 4, 2}, 
03424   {256 / 4, 256 / 2, 256 / 4, 2}, 
03425   {0,       256 / 2, 256 / 4, 2}, 
03426 };
03427 
03429 static inline void AffectSpeedByDirChange(Vehicle *v, Direction new_dir)
03430 {
03431   if (_settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL) return;
03432 
03433   DirDiff diff = DirDifference(v->direction, new_dir);
03434   if (diff == DIRDIFF_SAME) return;
03435 
03436   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->u.rail.railtype];
03437   v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03438 }
03439 
03441 static inline void AffectSpeedByZChange(Vehicle *v, byte old_z)
03442 {
03443   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL) return;
03444 
03445   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->u.rail.railtype];
03446 
03447   if (old_z < v->z_pos) {
03448     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
03449   } else {
03450     uint16 spd = v->cur_speed + rsp->z_down;
03451     if (spd <= v->max_speed) v->cur_speed = spd;
03452   }
03453 }
03454 
03455 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
03456 {
03457   if (IsTileType(tile, MP_RAILWAY) &&
03458       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
03459     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
03460     Trackdir trackdir = FindFirstTrackdir(tracks);
03461     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
03462       /* A PBS block with a non-PBS signal facing us? */
03463       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
03464     }
03465   }
03466   return false;
03467 }
03468 
03469 
03470 static void SetVehicleCrashed(Vehicle *v)
03471 {
03472   if (v->u.rail.crash_anim_pos != 0) return;
03473 
03474   if (IsFrontEngine(v)) {
03475     /* Remove the reserved path in front of the train if it is not stuck.
03476      * Also clear all reserved tracks the train is currently on. */
03477     if (!HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
03478     for (const Vehicle *u = v; u != NULL; u = u->Next()) {
03479       ClearPathReservation(u, u->tile, GetVehicleTrackdir(u));
03480       if (IsTileType(u->tile, MP_TUNNELBRIDGE)) {
03481         /* ClearPathReservation will not free the wormhole exit
03482          * if the train has just entered the wormhole. */
03483         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(u->tile), false);
03484       }
03485     }
03486   }
03487 
03488   /* we may need to update crossing we were approaching */
03489   TileIndex crossing = TrainApproachingCrossingTile(v);
03490 
03491   v->u.rail.crash_anim_pos++;
03492 
03493   InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03494   InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
03495 
03496   if (v->u.rail.track == TRACK_BIT_DEPOT) {
03497     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
03498   }
03499 
03500   InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
03501 
03502   for (; v != NULL; v = v->Next()) {
03503     v->vehstatus |= VS_CRASHED;
03504     MarkSingleVehicleDirty(v);
03505   }
03506 
03507   /* must be updated after the train has been marked crashed */
03508   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
03509 }
03510 
03511 static uint CountPassengersInTrain(const Vehicle *v)
03512 {
03513   uint num = 0;
03514 
03515   for (; v != NULL; v = v->Next()) {
03516     if (IsCargoInClass(v->cargo_type, CC_PASSENGERS)) num += v->cargo.Count();
03517   }
03518 
03519   return num;
03520 }
03521 
03528 static uint TrainCrashed(Vehicle *v)
03529 {
03530   /* do not crash train twice */
03531   if (v->vehstatus & VS_CRASHED) return 0;
03532 
03533   /* two drivers + passengers */
03534   uint num = 2 + CountPassengersInTrain(v);
03535 
03536   SetVehicleCrashed(v);
03537   AI::NewEvent(v->owner, new AIEventVehicleCrashed(v->index, v->tile, AIEventVehicleCrashed::CRASH_TRAIN));
03538 
03539   return num;
03540 }
03541 
03542 struct TrainCollideChecker {
03543   Vehicle *v;  
03544   uint num;    
03545 };
03546 
03547 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
03548 {
03549   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
03550 
03551   if (v->type != VEH_TRAIN) return NULL;
03552 
03553   /* get first vehicle now to make most usual checks faster */
03554   Vehicle *coll = v->First();
03555 
03556   /* can't collide with own wagons && can't crash in depot && the same height level */
03557   if (coll != tcc->v && v->u.rail.track != TRACK_BIT_DEPOT && abs(v->z_pos - tcc->v->z_pos) < 6) {
03558     int x_diff = v->x_pos - tcc->v->x_pos;
03559     int y_diff = v->y_pos - tcc->v->y_pos;
03560 
03561     /* needed to disable possible crash of competitor train in station by building diagonal track at its end */
03562     if (x_diff * x_diff + y_diff * y_diff > 25) return NULL;
03563 
03564     /* crash both trains */
03565     tcc->num += TrainCrashed(tcc->v);
03566     tcc->num += TrainCrashed(coll);
03567 
03568     /* Try to reserve all tiles directly under the crashed trains.
03569      * As there might be more than two trains involved, we have to do that for all vehicles */
03570     const Vehicle *u;
03571     FOR_ALL_VEHICLES(u) {
03572       if (u->type == VEH_TRAIN && HASBITS(u->vehstatus, VS_CRASHED) && (u->u.rail.track & TRACK_BIT_DEPOT) == TRACK_BIT_NONE) {
03573         TrackBits trackbits = u->u.rail.track;
03574         if ((trackbits & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03575           /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03576           trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(u->tile));
03577         }
03578         TryReserveRailTrack(u->tile, TrackBitsToTrack(trackbits));
03579       }
03580     }
03581   }
03582 
03583   return NULL;
03584 }
03585 
03592 static bool CheckTrainCollision(Vehicle *v)
03593 {
03594   /* can't collide in depot */
03595   if (v->u.rail.track == TRACK_BIT_DEPOT) return false;
03596 
03597   assert(v->u.rail.track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03598 
03599   TrainCollideChecker tcc;
03600   tcc.v = v;
03601   tcc.num = 0;
03602 
03603   /* find colliding vehicles */
03604   if (v->u.rail.track == TRACK_BIT_WORMHOLE) {
03605     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03606     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03607   } else {
03608     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03609   }
03610 
03611   /* any dead -> no crash */
03612   if (tcc.num == 0) return false;
03613 
03614   SetDParam(0, tcc.num);
03615   AddNewsItem(STR_8868_TRAIN_CRASH_DIE_IN_FIREBALL,
03616     NS_ACCIDENT_VEHICLE,
03617     v->index,
03618     0
03619   );
03620 
03621   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03622   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03623   return true;
03624 }
03625 
03626 static Vehicle *CheckVehicleAtSignal(Vehicle *v, void *data)
03627 {
03628   DiagDirection exitdir = *(DiagDirection *)data;
03629 
03630   /* front engine of a train, not inside wormhole or depot, not crashed */
03631   if (v->type == VEH_TRAIN && IsFrontEngine(v) && (v->u.rail.track & TRACK_BIT_MASK) != 0 && !(v->vehstatus & VS_CRASHED)) {
03632     if (v->cur_speed <= 5 && TrainExitDir(v->direction, v->u.rail.track) == exitdir) return v;
03633   }
03634 
03635   return NULL;
03636 }
03637 
03638 static void TrainController(Vehicle *v, Vehicle *nomove)
03639 {
03640   Vehicle *prev;
03641 
03642   /* For every vehicle after and including the given vehicle */
03643   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03644     DiagDirection enterdir = DIAGDIR_BEGIN;
03645     bool update_signals_crossing = false; // will we update signals or crossing state?
03646 
03647     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03648     if (v->u.rail.track != TRACK_BIT_WORMHOLE) {
03649       /* Not inside tunnel */
03650       if (gp.old_tile == gp.new_tile) {
03651         /* Staying in the old tile */
03652         if (v->u.rail.track == TRACK_BIT_DEPOT) {
03653           /* Inside depot */
03654           gp.x = v->x_pos;
03655           gp.y = v->y_pos;
03656         } else {
03657           /* Not inside depot */
03658 
03659           /* Reverse when we are at the end of the track already, do not move to the new position */
03660           if (IsFrontEngine(v) && !TrainCheckIfLineEnds(v)) return;
03661 
03662           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03663           if (HasBit(r, VETS_CANNOT_ENTER)) {
03664             goto invalid_rail;
03665           }
03666           if (HasBit(r, VETS_ENTERED_STATION)) {
03667             /* The new position is the end of the platform */
03668             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03669           }
03670         }
03671       } else {
03672         /* A new tile is about to be entered. */
03673 
03674         /* Determine what direction we're entering the new tile from */
03675         Direction dir = GetNewVehicleDirectionByTile(gp.new_tile, gp.old_tile);
03676         enterdir = DirToDiagDir(dir);
03677         assert(IsValidDiagDirection(enterdir));
03678 
03679         /* Get the status of the tracks in the new tile and mask
03680          * away the bits that aren't reachable. */
03681         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03682         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03683 
03684         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03685         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03686 
03687         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03688         if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg && prev == NULL) {
03689           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03690            * can be switched on halfway a turn */
03691           bits &= ~TrackCrossesTracks(FindFirstTrack(v->u.rail.track));
03692         }
03693 
03694         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03695 
03696         /* Check if the new tile contrains tracks that are compatible
03697          * with the current train, if not, bail out. */
03698         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03699 
03700         TrackBits chosen_track;
03701         if (prev == NULL) {
03702           /* Currently the locomotive is active. Determine which one of the
03703            * available tracks to choose */
03704           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03705           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03706 
03707           /* Check if it's a red signal and that force proceed is not clicked. */
03708           if (red_signals & chosen_track && v->u.rail.force_proceed == 0) {
03709             /* In front of a red signal */
03710             Trackdir i = FindFirstTrackdir(trackdirbits);
03711 
03712             /* Don't handle stuck trains here. */
03713             if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) return;
03714 
03715             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03716               v->cur_speed = 0;
03717               v->subspeed = 0;
03718               v->progress = 255 - 100;
03719               if (_settings_game.pf.wait_oneway_signal == 255 || ++v->load_unload_time_rem < _settings_game.pf.wait_oneway_signal * 20) return;
03720             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03721               v->cur_speed = 0;
03722               v->subspeed = 0;
03723               v->progress = 255 - 10;
03724               if (_settings_game.pf.wait_twoway_signal == 255 || ++v->load_unload_time_rem < _settings_game.pf.wait_twoway_signal * 73) {
03725                 DiagDirection exitdir = TrackdirToExitdir(i);
03726                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03727 
03728                 exitdir = ReverseDiagDir(exitdir);
03729 
03730                 /* check if a train is waiting on the other side */
03731                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckVehicleAtSignal)) return;
03732               }
03733             }
03734 
03735             /* If we would reverse but are currently in a PBS block and
03736              * reversing of stuck trains is disabled, don't reverse. */
03737             if (_settings_game.pf.wait_for_pbs_path == 255 && UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03738               v->load_unload_time_rem = 0;
03739               return;
03740             }
03741             goto reverse_train_direction;
03742           } else {
03743             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03744           }
03745         } else {
03746           static const TrackBits _matching_tracks[8] = {
03747               TRACK_BIT_LEFT  | TRACK_BIT_RIGHT, TRACK_BIT_X,
03748               TRACK_BIT_UPPER | TRACK_BIT_LOWER, TRACK_BIT_Y,
03749               TRACK_BIT_LEFT  | TRACK_BIT_RIGHT, TRACK_BIT_X,
03750               TRACK_BIT_UPPER | TRACK_BIT_LOWER, TRACK_BIT_Y
03751           };
03752 
03753           /* The wagon is active, simply follow the prev vehicle. */
03754           chosen_track = (TrackBits)(byte)(_matching_tracks[GetDirectionToVehicle(prev, gp.x, gp.y)] & bits);
03755         }
03756 
03757         /* Make sure chosen track is a valid track */
03758         assert(
03759             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03760             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03761             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03762 
03763         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03764         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03765         gp.x = (gp.x & ~0xF) | b[0];
03766         gp.y = (gp.y & ~0xF) | b[1];
03767         Direction chosen_dir = (Direction)b[2];
03768 
03769         /* Call the landscape function and tell it that the vehicle entered the tile */
03770         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03771         if (HasBit(r, VETS_CANNOT_ENTER)) {
03772           goto invalid_rail;
03773         }
03774 
03775         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03776           Track track = FindFirstTrack(chosen_track);
03777           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03778           if (IsFrontEngine(v) && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03779             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03780             MarkTileDirtyByTile(gp.new_tile);
03781           }
03782 
03783           /* Clear any track reservation when the last vehicle leaves the tile */
03784           if (v->Next() == NULL) ClearPathReservation(v, v->tile, GetVehicleTrackdir(v));
03785 
03786           v->tile = gp.new_tile;
03787 
03788           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03789             TrainPowerChanged(v->First());
03790           }
03791 
03792           v->u.rail.track = chosen_track;
03793           assert(v->u.rail.track);
03794         }
03795 
03796         /* We need to update signal status, but after the vehicle position hash
03797          * has been updated by AfterSetTrainPos() */
03798         update_signals_crossing = true;
03799 
03800         if (prev == NULL) AffectSpeedByDirChange(v, chosen_dir);
03801 
03802         v->direction = chosen_dir;
03803 
03804         if (IsFrontEngine(v)) {
03805           v->load_unload_time_rem = 0;
03806 
03807           /* If we are approching a crossing that is reserved, play the sound now. */
03808           TileIndex crossing = TrainApproachingCrossingTile(v);
03809           if (crossing != INVALID_TILE && GetCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03810 
03811           /* Always try to extend the reservation when entering a tile. */
03812           CheckNextTrainTile(v);
03813         }
03814       }
03815     } else {
03816       /* In a tunnel or on a bridge
03817        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03818        * - for bridges, only the middle part - without the bridge heads */
03819       if (!(v->vehstatus & VS_HIDDEN)) {
03820         v->cur_speed =
03821           min(v->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03822       }
03823 
03824       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03825         /* Perform look-ahead on tunnel exit. */
03826         if (IsFrontEngine(v)) {
03827           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03828           CheckNextTrainTile(v);
03829         }
03830       } else {
03831         v->x_pos = gp.x;
03832         v->y_pos = gp.y;
03833         VehicleMove(v, !(v->vehstatus & VS_HIDDEN));
03834         continue;
03835       }
03836     }
03837 
03838     /* update image of train, as well as delta XY */
03839     v->UpdateDeltaXY(v->direction);
03840 
03841     v->x_pos = gp.x;
03842     v->y_pos = gp.y;
03843 
03844     /* update the Z position of the vehicle */
03845     byte old_z = AfterSetTrainPos(v, (gp.new_tile != gp.old_tile));
03846 
03847     if (prev == NULL) {
03848       /* This is the first vehicle in the train */
03849       AffectSpeedByZChange(v, old_z);
03850     }
03851 
03852     if (update_signals_crossing) {
03853       if (IsFrontEngine(v)) {
03854         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03855           /* We are entering a block with PBS signals right now, but
03856            * not through a PBS signal. This means we don't have a
03857            * reservation right now. As a conventional signal will only
03858            * ever be green if no other train is in the block, getting
03859            * a path should always be possible. If the player built
03860            * such a strange network that it is not possible, the train
03861            * will be marked as stuck and the player has to deal with
03862            * the problem. */
03863           if ((!HasReservedTracks(gp.new_tile, v->u.rail.track) &&
03864               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->u.rail.track))) ||
03865               !TryPathReserve(v)) {
03866             MarkTrainAsStuck(v);
03867           }
03868         }
03869       }
03870 
03871       /* Signals can only change when the first
03872        * (above) or the last vehicle moves. */
03873       if (v->Next() == NULL) {
03874         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03875         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03876       }
03877     }
03878 
03879     /* Do not check on every tick to save some computing time. */
03880     if (IsFrontEngine(v) && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03881   }
03882   return;
03883 
03884 invalid_rail:
03885   /* We've reached end of line?? */
03886   if (prev != NULL) error("Disconnecting train");
03887 
03888 reverse_train_direction:
03889   v->load_unload_time_rem = 0;
03890   v->cur_speed = 0;
03891   v->subspeed = 0;
03892   ReverseTrainDirection(v);
03893 }
03894 
03900 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03901 {
03902   TrackBits *trackbits = (TrackBits *)data;
03903 
03904   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03905     if ((v->u.rail.track & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03906       /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03907       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03908     } else {
03909       *trackbits |= v->u.rail.track;
03910     }
03911   }
03912 
03913   return NULL;
03914 }
03915 
03923 static void DeleteLastWagon(Vehicle *v)
03924 {
03925   Vehicle *first = v->First();
03926 
03927   /* Go to the last wagon and delete the link pointing there
03928    * *u is then the one-before-last wagon, and *v the last
03929    * one which will physicially be removed */
03930   Vehicle *u = v;
03931   for (; v->Next() != NULL; v = v->Next()) u = v;
03932   u->SetNext(NULL);
03933 
03934   if (first != v) {
03935     /* Recalculate cached train properties */
03936     TrainConsistChanged(first, false);
03937     /* Update the depot window if the first vehicle is in depot -
03938      * if v == first, then it is updated in PreDestructor() */
03939     if (first->u.rail.track == TRACK_BIT_DEPOT) {
03940       InvalidateWindow(WC_VEHICLE_DEPOT, first->tile);
03941     }
03942   }
03943 
03944   /* 'v' shouldn't be accessed after it has been deleted */
03945   TrackBits trackbits = v->u.rail.track;
03946   TileIndex tile = v->tile;
03947   Owner owner = v->owner;
03948 
03949   delete v;
03950   v = NULL; // make sure nobody will try to read 'v' anymore
03951 
03952   if ((trackbits & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03953     /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03954     trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03955   }
03956 
03957   Track track = TrackBitsToTrack(trackbits);
03958   if (HasReservedTracks(tile, trackbits)) {
03959     UnreserveRailTrack(tile, track);
03960 
03961     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03962     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03963     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03964 
03965     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03966     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03967     for (Track t = TRACK_BEGIN; t < TRACK_END; t++) {
03968       if (HasBit(remaining_trackbits, t)) {
03969         TryReserveRailTrack(tile, t);
03970       }
03971     }
03972   }
03973 
03974   /* check if the wagon was on a road/rail-crossing */
03975   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03976 
03977   /* Update signals */
03978   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03979     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03980   } else {
03981     SetSignalsOnBothDir(tile, track, owner);
03982   }
03983 }
03984 
03985 static void ChangeTrainDirRandomly(Vehicle *v)
03986 {
03987   static const DirDiff delta[] = {
03988     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03989   };
03990 
03991   do {
03992     /* We don't need to twist around vehicles if they're not visible */
03993     if (!(v->vehstatus & VS_HIDDEN)) {
03994       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03995       v->UpdateDeltaXY(v->direction);
03996       v->cur_image = v->GetImage(v->direction);
03997       /* Refrain from updating the z position of the vehicle when on
03998        * a bridge, because AfterSetTrainPos will put the vehicle under
03999        * the bridge in that case */
04000       if (v->u.rail.track != TRACK_BIT_WORMHOLE) AfterSetTrainPos(v, false);
04001     }
04002   } while ((v = v->Next()) != NULL);
04003 }
04004 
04005 static void HandleCrashedTrain(Vehicle *v)
04006 {
04007   int state = ++v->u.rail.crash_anim_pos;
04008 
04009   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
04010     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
04011   }
04012 
04013   uint32 r;
04014   if (state <= 200 && Chance16R(1, 7, r)) {
04015     int index = (r * 10 >> 16);
04016 
04017     Vehicle *u = v;
04018     do {
04019       if (--index < 0) {
04020         r = Random();
04021 
04022         CreateEffectVehicleRel(u,
04023           GB(r,  8, 3) + 2,
04024           GB(r, 16, 3) + 2,
04025           GB(r,  0, 3) + 5,
04026           EV_EXPLOSION_SMALL);
04027         break;
04028       }
04029     } while ((u = u->Next()) != NULL);
04030   }
04031 
04032   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
04033 
04034   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
04035     DeleteLastWagon(v);
04036     InvalidateWindow(WC_REPLACE_VEHICLE, (v->group_id << 16) | VEH_TRAIN);
04037   }
04038 }
04039 
04040 static void HandleBrokenTrain(Vehicle *v)
04041 {
04042   if (v->breakdown_ctr != 1) {
04043     v->breakdown_ctr = 1;
04044     v->cur_speed = 0;
04045 
04046     if (v->breakdowns_since_last_service != 255)
04047       v->breakdowns_since_last_service++;
04048 
04049     InvalidateWindow(WC_VEHICLE_VIEW, v->index);
04050     InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
04051 
04052     if (!PlayVehicleSound(v, VSE_BREAKDOWN)) {
04053       SndPlayVehicleFx((_settings_game.game_creation.landscape != LT_TOYLAND) ?
04054         SND_10_TRAIN_BREAKDOWN : SND_3A_COMEDY_BREAKDOWN_2, v);
04055     }
04056 
04057     if (!(v->vehstatus & VS_HIDDEN)) {
04058       Vehicle *u = CreateEffectVehicleRel(v, 4, 4, 5, EV_BREAKDOWN_SMOKE);
04059       if (u != NULL) u->u.effect.animation_state = v->breakdown_delay * 2;
04060     }
04061   }
04062 
04063   if (!(v->tick_counter & 3)) {
04064     if (!--v->breakdown_delay) {
04065       v->breakdown_ctr = 0;
04066       InvalidateWindow(WC_VEHICLE_VIEW, v->index);
04067     }
04068   }
04069 }
04070 
04072 static const uint16 _breakdown_speeds[16] = {
04073   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
04074 };
04075 
04076 
04084 static bool TrainApproachingLineEnd(Vehicle *v, bool signal)
04085 {
04086   /* Calc position within the current tile */
04087   uint x = v->x_pos & 0xF;
04088   uint y = v->y_pos & 0xF;
04089 
04090   /* for diagonal directions, 'x' will be 0..15 -
04091    * for other directions, it will be 1, 3, 5, ..., 15 */
04092   switch (v->direction) {
04093     case DIR_N : x = ~x + ~y + 25; break;
04094     case DIR_NW: x = y;            // FALLTHROUGH
04095     case DIR_NE: x = ~x + 16;      break;
04096     case DIR_E : x = ~x + y + 9;   break;
04097     case DIR_SE: x = y;            break;
04098     case DIR_S : x = x + y - 7;    break;
04099     case DIR_W : x = ~y + x + 9;   break;
04100     default: break;
04101   }
04102 
04103   /* do not reverse when approaching red signal */
04104   if (!signal && x + (v->u.rail.cached_veh_length + 1) / 2 >= TILE_SIZE) {
04105     /* we are too near the tile end, reverse now */
04106     v->cur_speed = 0;
04107     ReverseTrainDirection(v);
04108     return false;
04109   }
04110 
04111   /* slow down */
04112   v->vehstatus |= VS_TRAIN_SLOWING;
04113   uint16 break_speed = _breakdown_speeds[x & 0xF];
04114   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
04115 
04116   return true;
04117 }
04118 
04119 
04125 static bool TrainCanLeaveTile(const Vehicle *v)
04126 {
04127   /* Exit if inside a tunnel/bridge or a depot */
04128   if (v->u.rail.track == TRACK_BIT_WORMHOLE || v->u.rail.track == TRACK_BIT_DEPOT) return false;
04129 
04130   TileIndex tile = v->tile;
04131 
04132   /* entering a tunnel/bridge? */
04133   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
04134     DiagDirection dir = GetTunnelBridgeDirection(tile);
04135     if (DiagDirToDir(dir) == v->direction) return false;
04136   }
04137 
04138   /* entering a depot? */
04139   if (IsRailDepotTile(tile)) {
04140     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
04141     if (DiagDirToDir(dir) == v->direction) return false;
04142   }
04143 
04144   return true;
04145 }
04146 
04147 
04155 static TileIndex TrainApproachingCrossingTile(const Vehicle *v)
04156 {
04157   assert(IsFrontEngine(v));
04158   assert(!(v->vehstatus & VS_CRASHED));
04159 
04160   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
04161 
04162   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
04163   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
04164 
04165   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
04166   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
04167       !CheckCompatibleRail(v, tile)) {
04168     return INVALID_TILE;
04169   }
04170 
04171   return tile;
04172 }
04173 
04174 
04181 static bool TrainCheckIfLineEnds(Vehicle *v)
04182 {
04183   /* First, handle broken down train */
04184 
04185   int t = v->breakdown_ctr;
04186   if (t > 1) {
04187     v->vehstatus |= VS_TRAIN_SLOWING;
04188 
04189     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
04190     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
04191   } else {
04192     v->vehstatus &= ~VS_TRAIN_SLOWING;
04193   }
04194 
04195   if (!TrainCanLeaveTile(v)) return true;
04196 
04197   /* Determine the non-diagonal direction in which we will exit this tile */
04198   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
04199   /* Calculate next tile */
04200   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
04201 
04202   /* Determine the track status on the next tile */
04203   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
04204   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
04205 
04206   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
04207   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
04208 
04209   /* We are sure the train is not entering a depot, it is detected above */
04210 
04211   /* mask unreachable track bits if we are forbidden to do 90deg turns */
04212   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
04213   if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
04214     bits &= ~TrackCrossesTracks(FindFirstTrack(v->u.rail.track));
04215   }
04216 
04217   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
04218   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
04219     return TrainApproachingLineEnd(v, false);
04220   }
04221 
04222   /* approaching red signal */
04223   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true);
04224 
04225   /* approaching a rail/road crossing? then make it red */
04226   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
04227 
04228   return true;
04229 }
04230 
04231 
04232 static void TrainLocoHandler(Vehicle *v, bool mode)
04233 {
04234   /* train has crashed? */
04235   if (v->vehstatus & VS_CRASHED) {
04236     if (!mode) HandleCrashedTrain(v);
04237     return;
04238   }
04239 
04240   if (v->u.rail.force_proceed != 0) {
04241     v->u.rail.force_proceed--;
04242     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
04243     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04244   }
04245 
04246   /* train is broken down? */
04247   if (v->breakdown_ctr != 0) {
04248     if (v->breakdown_ctr <= 2) {
04249       HandleBrokenTrain(v);
04250       return;
04251     }
04252     if (!v->current_order.IsType(OT_LOADING)) v->breakdown_ctr--;
04253   }
04254 
04255   if (HasBit(v->u.rail.flags, VRF_REVERSING) && v->cur_speed == 0) {
04256     ReverseTrainDirection(v);
04257   }
04258 
04259   /* exit if train is stopped */
04260   if (v->vehstatus & VS_STOPPED && v->cur_speed == 0) return;
04261 
04262   bool valid_order = v->current_order.IsValid() && v->current_order.GetType() != OT_CONDITIONAL;
04263   if (ProcessOrders(v) && CheckReverseTrain(v)) {
04264     v->load_unload_time_rem = 0;
04265     v->cur_speed = 0;
04266     v->subspeed = 0;
04267     ReverseTrainDirection(v);
04268     return;
04269   }
04270 
04271   v->HandleLoading(mode);
04272 
04273   if (v->current_order.IsType(OT_LOADING)) return;
04274 
04275   if (CheckTrainStayInDepot(v)) return;
04276 
04277   if (!mode) HandleLocomotiveSmokeCloud(v);
04278 
04279   /* We had no order but have an order now, do look ahead. */
04280   if (!valid_order && v->current_order.IsValid()) {
04281     CheckNextTrainTile(v);
04282   }
04283 
04284   /* Handle stuck trains. */
04285   if (!mode && HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
04286     ++v->load_unload_time_rem;
04287 
04288     /* Should we try reversing this tick if still stuck? */
04289     bool turn_around = v->load_unload_time_rem % (_settings_game.pf.wait_for_pbs_path * DAY_TICKS) == 0 && _settings_game.pf.wait_for_pbs_path < 255;
04290 
04291     if (!turn_around && v->load_unload_time_rem % _settings_game.pf.path_backoff_interval != 0 && v->u.rail.force_proceed == 0) return;
04292     if (!TryPathReserve(v)) {
04293       /* Still stuck. */
04294       if (turn_around) ReverseTrainDirection(v);
04295 
04296       if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK) && v->load_unload_time_rem > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
04297         /* Show message to player. */
04298         if (_settings_client.gui.lost_train_warn && v->owner == _local_company) {
04299           SetDParam(0, v->index);
04300           AddNewsItem(
04301             STR_TRAIN_IS_STUCK,
04302             NS_ADVICE,
04303             v->index,
04304             0);
04305         }
04306         v->load_unload_time_rem = 0;
04307       }
04308       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
04309       if (v->u.rail.force_proceed == 0) return;
04310       ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
04311       v->load_unload_time_rem = 0;
04312       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04313     }
04314   }
04315 
04316   if (v->current_order.IsType(OT_LEAVESTATION)) {
04317     v->current_order.Free();
04318     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04319     return;
04320   }
04321 
04322   int j = UpdateTrainSpeed(v);
04323 
04324   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
04325   if (v->cur_speed == 0 && v->u.rail.last_speed == 0 && v->vehstatus & VS_STOPPED) {
04326     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04327   }
04328 
04329   int adv_spd = (v->direction & 1) ? 192 : 256;
04330   if (j < adv_spd) {
04331     /* if the vehicle has speed 0, update the last_speed field. */
04332     if (v->cur_speed == 0) SetLastSpeed(v, v->cur_speed);
04333   } else {
04334     TrainCheckIfLineEnds(v);
04335     /* Loop until the train has finished moving. */
04336     for (;;) {
04337       j -= adv_spd;
04338       TrainController(v, NULL);
04339       /* Don't continue to move if the train crashed. */
04340       if (CheckTrainCollision(v)) break;
04341       /* 192 spd used for going straight, 256 for going diagonally. */
04342       adv_spd = (v->direction & 1) ? 192 : 256;
04343 
04344       /* No more moving this tick */
04345       if (j < adv_spd || v->cur_speed == 0) break;
04346 
04347       OrderType order_type = v->current_order.GetType();
04348       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
04349       if ((order_type == OT_GOTO_WAYPOINT &&
04350             v->dest_tile == v->tile) ||
04351           (order_type == OT_GOTO_STATION &&
04352             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
04353             IsTileType(v->tile, MP_STATION) &&
04354             v->current_order.GetDestination() == GetStationIndex(v->tile))) {
04355         ProcessOrders(v);
04356       }
04357     }
04358     SetLastSpeed(v, v->cur_speed);
04359   }
04360 
04361   for (Vehicle *u = v; u != NULL; u = u->Next()) {
04362     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
04363 
04364     u->UpdateViewport(false, false);
04365   }
04366 
04367   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
04368 }
04369 
04370 
04371 
04372 Money Train::GetRunningCost() const
04373 {
04374   Money cost = 0;
04375   const Vehicle *v = this;
04376 
04377   do {
04378     const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
04379 
04380     byte cost_factor = GetVehicleProperty(v, 0x0D, rvi->running_cost);
04381     if (cost_factor == 0) continue;
04382 
04383     /* Halve running cost for multiheaded parts */
04384     if (IsMultiheaded(v)) cost_factor /= 2;
04385 
04386     cost += cost_factor * GetPriceByIndex(rvi->running_cost_class);
04387   } while ((v = GetNextVehicle(v)) != NULL);
04388 
04389   return cost;
04390 }
04391 
04392 
04393 void Train::Tick()
04394 {
04395   if (_age_cargo_skip_counter == 0) this->cargo.AgeCargo();
04396 
04397   this->tick_counter++;
04398 
04399   if (IsFrontEngine(this)) {
04400     if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;
04401     this->current_order_time++;
04402 
04403     TrainLocoHandler(this, false);
04404 
04405     /* make sure vehicle wasn't deleted. */
04406     if (this->type == VEH_TRAIN && IsFrontEngine(this))
04407       TrainLocoHandler(this, true);
04408   } else if (IsFreeWagon(this) && HASBITS(this->vehstatus, VS_CRASHED)) {
04409     /* Delete flooded standalone wagon chain */
04410     if (++this->u.rail.crash_anim_pos >= 4400) delete this;
04411   }
04412 }
04413 
04414 static void CheckIfTrainNeedsService(Vehicle *v)
04415 {
04416   static const uint MAX_ACCEPTABLE_DEPOT_DIST = 16;
04417 
04418   if (_settings_game.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
04419   if (v->IsInDepot()) {
04420     VehicleServiceInDepot(v);
04421     return;
04422   }
04423 
04424   TrainFindDepotData tfdd = FindClosestTrainDepot(v, MAX_ACCEPTABLE_DEPOT_DIST);
04425   /* Only go to the depot if it is not too far out of our way. */
04426   if (tfdd.best_length == UINT_MAX || tfdd.best_length > MAX_ACCEPTABLE_DEPOT_DIST) {
04427     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
04428       /* If we were already heading for a depot but it has
04429        * suddenly moved farther away, we continue our normal
04430        * schedule? */
04431       v->current_order.MakeDummy();
04432       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04433     }
04434     return;
04435   }
04436 
04437   const Depot *depot = GetDepotByTile(tfdd.tile);
04438 
04439   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
04440       v->current_order.GetDestination() != depot->index &&
04441       !Chance16(3, 16)) {
04442     return;
04443   }
04444 
04445   v->current_order.MakeGoToDepot(depot->index, ODTFB_SERVICE);
04446   v->dest_tile = tfdd.tile;
04447   InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04448 }
04449 
04450 void Train::OnNewDay()
04451 {
04452   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
04453 
04454   if (IsFrontEngine(this)) {
04455     CheckVehicleBreakdown(this);
04456     AgeVehicle(this);
04457 
04458     CheckIfTrainNeedsService(this);
04459 
04460     CheckOrders(this);
04461 
04462     /* update destination */
04463     if (this->current_order.IsType(OT_GOTO_STATION)) {
04464       TileIndex tile = GetStation(this->current_order.GetDestination())->train_tile;
04465       if (tile != INVALID_TILE) this->dest_tile = tile;
04466     }
04467 
04468     if (this->running_ticks != 0) {
04469       /* running costs */
04470       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
04471 
04472       this->profit_this_year -= cost.GetCost();
04473       this->running_ticks = 0;
04474 
04475       SubtractMoneyFromCompanyFract(this->owner, cost);
04476 
04477       InvalidateWindow(WC_VEHICLE_DETAILS, this->index);
04478       InvalidateWindowClasses(WC_TRAINS_LIST);
04479     }
04480   } else if (IsTrainEngine(this)) {
04481     /* Also age engines that aren't front engines */
04482     AgeVehicle(this);
04483   }
04484 }
04485 
04486 void InitializeTrains()
04487 {
04488   _age_cargo_skip_counter = 1;
04489 }

Generated on Sun Sep 13 08:19:21 2009 for OpenTTD by  doxygen 1.5.6