train_cmd.cpp

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00001 /* $Id: train_cmd.cpp 17598 2009-09-21 15:41:58Z 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       if (src_head == src && !HasBit(p2, 0)) {
01065         /* Moving of a *single* vehicle at the front of the train.
01066          * If the next vehicle is an engine a new train will be created
01067          * instead of removing a vehicle from a free chain. The newly
01068          * created train may not be too long. */
01069         const Vehicle *u = GetNextVehicle(src_head);
01070         if (u != NULL && IsTrainEngine(u) && (src_len - 1) > max_len) return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01071       }
01072 
01073       /* We are moving between rows, so only count the wagons from the source
01074        * row that are being moved. */
01075       if (HasBit(p2, 0)) {
01076         const Vehicle *u;
01077         for (u = src_head; u != src && u != NULL; u = GetNextVehicle(u))
01078           src_len--;
01079       } else {
01080         /* If moving only one vehicle, just count that. */
01081         src_len = 1;
01082       }
01083 
01084       if (src_len + dst_len > max_len) {
01085         /* Abort if we're adding too many wagons to a train. */
01086         if (dst_head != NULL && IsFrontEngine(dst_head)) return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01087         /* Abort if we're making a train on a new row. */
01088         if (dst_head == NULL && IsTrainEngine(src)) return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01089       }
01090     } else {
01091       /* Abort if we're creating a new train on an existing row. */
01092       if (src_len > max_len && src == src_head && IsTrainEngine(GetNextVehicle(src_head)))
01093         return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01094     }
01095   }
01096 
01097   /* moving a loco to a new line?, then we need to assign a unitnumber. */
01098   if (dst == NULL && !IsFrontEngine(src) && IsTrainEngine(src)) {
01099     UnitID unit_num = ((flags & DC_AUTOREPLACE) != 0 ? 0 : GetFreeUnitNumber(VEH_TRAIN));
01100     if (unit_num > _settings_game.vehicle.max_trains)
01101       return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
01102 
01103     if (flags & DC_EXEC) src->unitnumber = unit_num;
01104   }
01105 
01106   /* When we move the front vehicle, the second vehicle might need a unitnumber */
01107   if (!HasBit(p2, 0) && (IsFreeWagon(src) || (IsFrontEngine(src) && dst == NULL)) && (flags & DC_AUTOREPLACE) == 0) {
01108     Vehicle *second = GetNextUnit(src);
01109     if (second != NULL && IsTrainEngine(second) && GetFreeUnitNumber(VEH_TRAIN) > _settings_game.vehicle.max_trains) {
01110       return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
01111     }
01112   }
01113 
01114   /*
01115    * Check whether the vehicles in the source chain are in the destination
01116    * chain. This can easily be done by checking whether the first vehicle
01117    * of the source chain is in the destination chain as the Next/Previous
01118    * pointers always make a doubly linked list of it where the assumption
01119    * v->Next()->Previous() == v holds (assuming v->Next() != NULL).
01120    */
01121   bool src_in_dst = false;
01122   for (Vehicle *v = dst_head; !src_in_dst && v != NULL; v = v->Next()) src_in_dst = v == src;
01123 
01124   /*
01125    * If the source chain is in the destination chain then the user is
01126    * only reordering the vehicles, thus not attaching a new vehicle.
01127    * Therefor the 'allow wagon attach' callback does not need to be
01128    * called. If it would be called strange things would happen because
01129    * one 'attaches' an already 'attached' vehicle causing more trouble
01130    * than it actually solves (infinite loops and such).
01131    */
01132   if (dst_head != NULL && !src_in_dst && (flags & DC_AUTOREPLACE) == 0) {
01133     /*
01134      * When performing the 'allow wagon attach' callback, we have to check
01135      * that for each and every wagon, not only the first one. This means
01136      * that we have to test one wagon, attach it to the train and then test
01137      * the next wagon till we have reached the end. We have to restore it
01138      * to the state it was before we 'tried' attaching the train when the
01139      * attaching fails or succeeds because we are not 'only' doing this
01140      * in the DC_EXEC state.
01141      */
01142     Vehicle *dst_tail = dst_head;
01143     while (dst_tail->Next() != NULL) dst_tail = dst_tail->Next();
01144 
01145     Vehicle *orig_tail = dst_tail;
01146     Vehicle *next_to_attach = src;
01147     Vehicle *src_previous = src->Previous();
01148 
01149     while (next_to_attach != NULL) {
01150       /* Don't check callback for articulated or rear dual headed parts */
01151       if (!IsArticulatedPart(next_to_attach) && !IsRearDualheaded(next_to_attach)) {
01152         /* Back up and clear the first_engine data to avoid using wagon override group */
01153         EngineID first_engine = next_to_attach->u.rail.first_engine;
01154         next_to_attach->u.rail.first_engine = INVALID_ENGINE;
01155 
01156         uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, dst_head->engine_type, next_to_attach, dst_head);
01157 
01158         /* Restore original first_engine data */
01159         next_to_attach->u.rail.first_engine = first_engine;
01160 
01161         if (callback != CALLBACK_FAILED) {
01162           StringID error = STR_NULL;
01163 
01164           if (callback == 0xFD) error = STR_INCOMPATIBLE_RAIL_TYPES;
01165           if (callback < 0xFD) error = GetGRFStringID(GetEngineGRFID(dst_head->engine_type), 0xD000 + callback);
01166 
01167           if (error != STR_NULL) {
01168             /*
01169              * The attaching is not allowed. In this case 'next_to_attach'
01170              * can contain some vehicles of the 'source' and the destination
01171              * train can have some too. We 'just' add the to-be added wagons
01172              * to the chain and then split it where it was previously
01173              * separated, i.e. the tail of the original destination train.
01174              * Furthermore the 'previous' link of the original source vehicle needs
01175              * to be restored, otherwise the train goes missing in the depot.
01176              */
01177             dst_tail->SetNext(next_to_attach);
01178             orig_tail->SetNext(NULL);
01179             if (src_previous != NULL) src_previous->SetNext(src);
01180 
01181             return_cmd_error(error);
01182           }
01183         }
01184       }
01185 
01186       /* Only check further wagons if told to move the chain */
01187       if (!HasBit(p2, 0)) break;
01188 
01189       /*
01190        * Adding a next wagon to the chain so we can test the other wagons.
01191        * First 'take' the first wagon from 'next_to_attach' and move it
01192        * to the next wagon. Then add that to the tail of the destination
01193        * train and update the tail with the new vehicle.
01194        */
01195       Vehicle *to_add = next_to_attach;
01196       next_to_attach = next_to_attach->Next();
01197 
01198       to_add->SetNext(NULL);
01199       dst_tail->SetNext(to_add);
01200       dst_tail = dst_tail->Next();
01201     }
01202 
01203     /*
01204      * When we reach this the attaching is allowed. It also means that the
01205      * chain of vehicles to attach is empty, so we do not need to merge that.
01206      * This means only the splitting needs to be done.
01207      * Furthermore the 'previous' link of the original source vehicle needs
01208      * to be restored, otherwise the train goes missing in the depot.
01209      */
01210     orig_tail->SetNext(NULL);
01211     if (src_previous != NULL) src_previous->SetNext(src);
01212   }
01213 
01214   /* do it? */
01215   if (flags & DC_EXEC) {
01216     /* If we move the front Engine and if the second vehicle is not an engine
01217        add the whole vehicle to the DEFAULT_GROUP */
01218     if (IsFrontEngine(src) && !IsDefaultGroupID(src->group_id)) {
01219       Vehicle *v = GetNextVehicle(src);
01220 
01221       if (v != NULL && IsTrainEngine(v)) {
01222         v->group_id   = src->group_id;
01223         src->group_id = DEFAULT_GROUP;
01224       }
01225     }
01226 
01227     if (HasBit(p2, 0)) {
01228       /* unlink ALL wagons */
01229       if (src != src_head) {
01230         Vehicle *v = src_head;
01231         while (GetNextVehicle(v) != src) v = GetNextVehicle(v);
01232         GetLastEnginePart(v)->SetNext(NULL);
01233       } else {
01234         InvalidateWindowData(WC_VEHICLE_DEPOT, src_head->tile); // We removed a line
01235         src_head = NULL;
01236       }
01237     } else {
01238       /* if moving within the same chain, dont use dst_head as it may get invalidated */
01239       if (src_head == dst_head) dst_head = NULL;
01240       /* unlink single wagon from linked list */
01241       src_head = UnlinkWagon(src, src_head);
01242       GetLastEnginePart(src)->SetNext(NULL);
01243     }
01244 
01245     if (dst == NULL) {
01246       /* We make a new line in the depot, so we know already that we invalidate the window data */
01247       InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01248 
01249       /* move the train to an empty line. for locomotives, we set the type to TS_Front. for wagons, 4. */
01250       if (IsTrainEngine(src)) {
01251         if (!IsFrontEngine(src)) {
01252           /* setting the type to 0 also involves setting up the orders field. */
01253           SetFrontEngine(src);
01254           assert(src->orders.list == NULL);
01255 
01256           /* Decrease the engines number of the src engine_type */
01257           if (!IsDefaultGroupID(src->group_id) && IsValidGroupID(src->group_id)) {
01258             GetGroup(src->group_id)->num_engines[src->engine_type]--;
01259           }
01260 
01261           /* If we move an engine to a new line affect it to the DEFAULT_GROUP */
01262           src->group_id = DEFAULT_GROUP;
01263         }
01264       } else {
01265         SetFreeWagon(src);
01266       }
01267       dst_head = src;
01268     } else {
01269       if (IsFrontEngine(src)) {
01270         /* the vehicle was previously a loco. need to free the order list and delete vehicle windows etc. */
01271         DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01272         DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01273         DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01274         DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01275         DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01276         DeleteVehicleOrders(src);
01277         RemoveVehicleFromGroup(src);
01278       }
01279 
01280       if (IsFrontEngine(src) || IsFreeWagon(src)) {
01281         InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01282         ClearFrontEngine(src);
01283         ClearFreeWagon(src);
01284         src->unitnumber = 0; // doesn't occupy a unitnumber anymore.
01285       }
01286 
01287       /* link in the wagon(s) in the chain. */
01288       {
01289         Vehicle *v;
01290 
01291         for (v = src; GetNextVehicle(v) != NULL; v = GetNextVehicle(v)) {}
01292         GetLastEnginePart(v)->SetNext(dst->Next());
01293       }
01294       dst->SetNext(src);
01295     }
01296 
01297     if (src->u.rail.other_multiheaded_part != NULL) {
01298       if (src->u.rail.other_multiheaded_part == src_head) {
01299         src_head = src_head->Next();
01300       }
01301       AddWagonToConsist(src->u.rail.other_multiheaded_part, src);
01302     }
01303 
01304     /* If there is an engine behind first_engine we moved away, it should become new first_engine
01305      * To do this, CmdMoveRailVehicle must be called once more
01306      * we can't loop forever here because next time we reach this line we will have a front engine */
01307     if (src_head != NULL && !IsFrontEngine(src_head) && IsTrainEngine(src_head)) {
01308       /* As in CmdMoveRailVehicle src_head->group_id will be equal to DEFAULT_GROUP
01309        * we need to save the group and reaffect it to src_head */
01310       const GroupID tmp_g = src_head->group_id;
01311       CmdMoveRailVehicle(0, flags, src_head->index | (INVALID_VEHICLE << 16), 1, text);
01312       SetTrainGroupID(src_head, tmp_g);
01313       src_head = NULL; // don't do anything more to this train since the new call will do it
01314     }
01315 
01316     if (src_head != NULL) {
01317       NormaliseTrainConsist(src_head);
01318       TrainConsistChanged(src_head, false);
01319       UpdateTrainGroupID(src_head);
01320       if (IsFrontEngine(src_head)) {
01321         /* Update the refit button and window */
01322         InvalidateWindow(WC_VEHICLE_REFIT, src_head->index);
01323         InvalidateWindowWidget(WC_VEHICLE_VIEW, src_head->index, VVW_WIDGET_REFIT_VEH);
01324       }
01325       /* Update the depot window */
01326       InvalidateWindow(WC_VEHICLE_DEPOT, src_head->tile);
01327     }
01328 
01329     if (dst_head != NULL) {
01330       NormaliseTrainConsist(dst_head);
01331       TrainConsistChanged(dst_head, false);
01332       UpdateTrainGroupID(dst_head);
01333       if (IsFrontEngine(dst_head)) {
01334         /* Update the refit button and window */
01335         InvalidateWindowWidget(WC_VEHICLE_VIEW, dst_head->index, VVW_WIDGET_REFIT_VEH);
01336         InvalidateWindow(WC_VEHICLE_REFIT, dst_head->index);
01337       }
01338       /* Update the depot window */
01339       InvalidateWindow(WC_VEHICLE_DEPOT, dst_head->tile);
01340     }
01341 
01342     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01343   }
01344 
01345   return CommandCost();
01346 }
01347 
01357 CommandCost CmdSellRailWagon(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01358 {
01359   /* Check if we deleted a vehicle window */
01360   Window *w = NULL;
01361 
01362   if (!IsValidVehicleID(p1) || p2 > 1) return CMD_ERROR;
01363 
01364   Vehicle *v = GetVehicle(p1);
01365 
01366   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01367 
01368   if (HASBITS(v->vehstatus, VS_CRASHED)) return_cmd_error(STR_CAN_T_SELL_DESTROYED_VEHICLE);
01369 
01370   while (IsArticulatedPart(v)) v = v->Previous();
01371   Vehicle *first = v->First();
01372 
01373   /* make sure the vehicle is stopped in the depot */
01374   if (CheckTrainStoppedInDepot(first) < 0) {
01375     return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01376   }
01377 
01378   if (IsRearDualheaded(v)) return_cmd_error(STR_REAR_ENGINE_FOLLOW_FRONT_ERROR);
01379 
01380   if (flags & DC_EXEC) {
01381     if (v == first && IsFrontEngine(first)) {
01382       DeleteWindowById(WC_VEHICLE_VIEW, first->index);
01383       DeleteWindowById(WC_VEHICLE_ORDERS, first->index);
01384       DeleteWindowById(WC_VEHICLE_REFIT, first->index);
01385       DeleteWindowById(WC_VEHICLE_DETAILS, first->index);
01386       DeleteWindowById(WC_VEHICLE_TIMETABLE, first->index);
01387     }
01388     InvalidateWindow(WC_VEHICLE_DEPOT, first->tile);
01389     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01390   }
01391 
01392   CommandCost cost(EXPENSES_NEW_VEHICLES);
01393   switch (p2) {
01394     case 0: { // Delete given wagon
01395       bool switch_engine = false;    // update second wagon to engine?
01396 
01397       /* 1. Delete the engine, if it is dualheaded also delete the matching
01398        * rear engine of the loco (from the point of deletion onwards) */
01399       Vehicle *rear = (IsMultiheaded(v) &&
01400         IsTrainEngine(v)) ? v->u.rail.other_multiheaded_part : NULL;
01401 
01402       if (rear != NULL) {
01403         cost.AddCost(-rear->value);
01404         if (flags & DC_EXEC) {
01405           UnlinkWagon(rear, first);
01406           delete rear;
01407         }
01408       }
01409 
01410       /* 2. We are selling the front vehicle, some special action might be required
01411        * here, so take attention */
01412       if (v == first) {
01413         Vehicle *new_f = GetNextVehicle(first);
01414 
01415         /* 2.2 If there are wagons present after the deleted front engine, check
01416          * if the second wagon (which will be first) is an engine. If it is one,
01417          * promote it as a new train, retaining the unitnumber, orders */
01418         if (new_f != NULL && IsTrainEngine(new_f)) {
01419           if (IsTrainEngine(first)) {
01420             /* Let the new front engine take over the setup of the old engine */
01421             switch_engine = true;
01422 
01423             if (flags & DC_EXEC) {
01424               /* Make sure the group counts stay correct. */
01425               new_f->group_id        = first->group_id;
01426               first->group_id        = DEFAULT_GROUP;
01427 
01428               /* Copy orders (by sharing) */
01429               new_f->orders.list     = first->orders.list;
01430               new_f->AddToShared(first);
01431               DeleteVehicleOrders(first);
01432 
01433               /* Copy other important data from the front engine */
01434               new_f->CopyVehicleConfigAndStatistics(first);
01435 
01436               /* If we deleted a window then open a new one for the 'new' train */
01437               if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_f);
01438             }
01439           } else {
01440             /* We are selling a free wagon, and construct a new train at the same time.
01441              * This needs lots of extra checks (e.g. train limit), which are done by first moving
01442              * the remaining vehicles to a new row */
01443             cost.AddCost(DoCommand(0, new_f->index | INVALID_VEHICLE << 16, 1, flags, CMD_MOVE_RAIL_VEHICLE));
01444             if (cost.Failed()) return cost;
01445           }
01446         }
01447       }
01448 
01449       /* 3. Delete the requested wagon */
01450       cost.AddCost(-v->value);
01451       if (flags & DC_EXEC) {
01452         first = UnlinkWagon(v, first);
01453         delete v;
01454 
01455         /* 4 If the second wagon was an engine, update it to front_engine
01456          * which UnlinkWagon() has changed to TS_Free_Car */
01457         if (switch_engine) SetFrontEngine(first);
01458 
01459         /* 5. If the train still exists, update its acceleration, window, etc. */
01460         if (first != NULL) {
01461           NormaliseTrainConsist(first);
01462           TrainConsistChanged(first, false);
01463           UpdateTrainGroupID(first);
01464           if (IsFrontEngine(first)) InvalidateWindow(WC_VEHICLE_REFIT, first->index);
01465         }
01466 
01467       }
01468     } break;
01469     case 1: { // Delete wagon and all wagons after it given certain criteria
01470       /* Start deleting every vehicle after the selected one
01471        * If we encounter a matching rear-engine to a front-engine
01472        * earlier in the chain (before deletion), leave it alone */
01473       for (Vehicle *tmp; v != NULL; v = tmp) {
01474         tmp = GetNextVehicle(v);
01475 
01476         if (IsMultiheaded(v)) {
01477           if (IsTrainEngine(v)) {
01478             /* We got a front engine of a multiheaded set. Now we will sell the rear end too */
01479             Vehicle *rear = v->u.rail.other_multiheaded_part;
01480 
01481             if (rear != NULL) {
01482               cost.AddCost(-rear->value);
01483 
01484               /* If this is a multiheaded vehicle with nothing
01485                * between the parts, tmp will be pointing to the
01486                * rear part, which is unlinked from the train and
01487                * deleted here. However, because tmp has already
01488                * been set it needs to be updated now so that the
01489                * loop never sees the rear part. */
01490               if (tmp == rear) tmp = GetNextVehicle(tmp);
01491 
01492               if (flags & DC_EXEC) {
01493                 first = UnlinkWagon(rear, first);
01494                 delete rear;
01495               }
01496             }
01497           } else if (v->u.rail.other_multiheaded_part != NULL) {
01498             /* The front to this engine is earlier in this train. Do nothing */
01499             continue;
01500           }
01501         }
01502 
01503         cost.AddCost(-v->value);
01504         if (flags & DC_EXEC) {
01505           first = UnlinkWagon(v, first);
01506           delete v;
01507         }
01508       }
01509 
01510       /* 3. If it is still a valid train after selling, update its acceleration and cached values */
01511       if (flags & DC_EXEC && first != NULL) {
01512         NormaliseTrainConsist(first);
01513         TrainConsistChanged(first, false);
01514         UpdateTrainGroupID(first);
01515         InvalidateWindow(WC_VEHICLE_REFIT, first->index);
01516       }
01517     } break;
01518   }
01519   return cost;
01520 }
01521 
01522 void Train::UpdateDeltaXY(Direction direction)
01523 {
01524 #define MKIT(a, b, c, d) ((a & 0xFF) << 24) | ((b & 0xFF) << 16) | ((c & 0xFF) << 8) | ((d & 0xFF) << 0)
01525   static const uint32 _delta_xy_table[8] = {
01526     MKIT(3, 3, -1, -1),
01527     MKIT(3, 7, -1, -3),
01528     MKIT(3, 3, -1, -1),
01529     MKIT(7, 3, -3, -1),
01530     MKIT(3, 3, -1, -1),
01531     MKIT(3, 7, -1, -3),
01532     MKIT(3, 3, -1, -1),
01533     MKIT(7, 3, -3, -1),
01534   };
01535 #undef MKIT
01536 
01537   uint32 x = _delta_xy_table[direction];
01538   this->x_offs        = GB(x,  0, 8);
01539   this->y_offs        = GB(x,  8, 8);
01540   this->x_extent      = GB(x, 16, 8);
01541   this->y_extent      = GB(x, 24, 8);
01542   this->z_extent      = 6;
01543 }
01544 
01545 static inline void SetLastSpeed(Vehicle *v, int spd)
01546 {
01547   int old = v->u.rail.last_speed;
01548   if (spd != old) {
01549     v->u.rail.last_speed = spd;
01550     if (_settings_client.gui.vehicle_speed || (old == 0) != (spd == 0)) {
01551       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01552     }
01553   }
01554 }
01555 
01557 static void MarkTrainAsStuck(Vehicle *v)
01558 {
01559   if (!HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
01560     /* It is the first time the problem occured, set the "train stuck" flag. */
01561     SetBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01562 
01563     /* When loading the vehicle is already stopped. No need to change that. */
01564     if (v->current_order.IsType(OT_LOADING)) return;
01565 
01566     v->load_unload_time_rem = 0;
01567 
01568     /* Stop train */
01569     v->cur_speed = 0;
01570     v->subspeed = 0;
01571     SetLastSpeed(v, 0);
01572 
01573     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01574   }
01575 }
01576 
01577 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01578 {
01579   uint16 flag1 = *swap_flag1;
01580   uint16 flag2 = *swap_flag2;
01581 
01582   /* Clear the flags */
01583   ClrBit(*swap_flag1, VRF_GOINGUP);
01584   ClrBit(*swap_flag1, VRF_GOINGDOWN);
01585   ClrBit(*swap_flag2, VRF_GOINGUP);
01586   ClrBit(*swap_flag2, VRF_GOINGDOWN);
01587 
01588   /* Reverse the rail-flags (if needed) */
01589   if (HasBit(flag1, VRF_GOINGUP)) {
01590     SetBit(*swap_flag2, VRF_GOINGDOWN);
01591   } else if (HasBit(flag1, VRF_GOINGDOWN)) {
01592     SetBit(*swap_flag2, VRF_GOINGUP);
01593   }
01594   if (HasBit(flag2, VRF_GOINGUP)) {
01595     SetBit(*swap_flag1, VRF_GOINGDOWN);
01596   } else if (HasBit(flag2, VRF_GOINGDOWN)) {
01597     SetBit(*swap_flag1, VRF_GOINGUP);
01598   }
01599 }
01600 
01601 static void ReverseTrainSwapVeh(Vehicle *v, int l, int r)
01602 {
01603   Vehicle *a, *b;
01604 
01605   /* locate vehicles to swap */
01606   for (a = v; l != 0; l--) a = a->Next();
01607   for (b = v; r != 0; r--) b = b->Next();
01608 
01609   if (a != b) {
01610     /* swap the hidden bits */
01611     {
01612       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus&VS_HIDDEN);
01613       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus&VS_HIDDEN);
01614       a->vehstatus = tmp;
01615     }
01616 
01617     Swap(a->u.rail.track, b->u.rail.track);
01618     Swap(a->direction,    b->direction);
01619 
01620     /* toggle direction */
01621     if (a->u.rail.track != TRACK_BIT_DEPOT) a->direction = ReverseDir(a->direction);
01622     if (b->u.rail.track != TRACK_BIT_DEPOT) b->direction = ReverseDir(b->direction);
01623 
01624     Swap(a->x_pos, b->x_pos);
01625     Swap(a->y_pos, b->y_pos);
01626     Swap(a->tile,  b->tile);
01627     Swap(a->z_pos, b->z_pos);
01628 
01629     SwapTrainFlags(&a->u.rail.flags, &b->u.rail.flags);
01630 
01631     /* update other vars */
01632     a->UpdateViewport(true, true);
01633     b->UpdateViewport(true, true);
01634 
01635     /* call the proper EnterTile function unless we are in a wormhole */
01636     if (a->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
01637     if (b->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(b, b->tile, b->x_pos, b->y_pos);
01638   } else {
01639     if (a->u.rail.track != TRACK_BIT_DEPOT) a->direction = ReverseDir(a->direction);
01640     a->UpdateViewport(true, true);
01641 
01642     if (a->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
01643   }
01644 
01645   /* Update train's power incase tiles were different rail type */
01646   TrainPowerChanged(v);
01647 }
01648 
01649 
01655 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01656 {
01657   return (v->type == VEH_TRAIN) ? v : NULL;
01658 }
01659 
01660 
01667 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01668 {
01669   /* not a train || not front engine || crashed */
01670   if (v->type != VEH_TRAIN || !IsFrontEngine(v) || v->vehstatus & VS_CRASHED) return NULL;
01671 
01672   TileIndex tile = *(TileIndex*)data;
01673 
01674   if (TrainApproachingCrossingTile(v) != tile) return NULL;
01675 
01676   return v;
01677 }
01678 
01679 
01686 static bool TrainApproachingCrossing(TileIndex tile)
01687 {
01688   assert(IsLevelCrossingTile(tile));
01689 
01690   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01691   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01692 
01693   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01694 
01695   dir = ReverseDiagDir(dir);
01696   tile_from = tile + TileOffsByDiagDir(dir);
01697 
01698   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01699 }
01700 
01701 
01708 void UpdateLevelCrossing(TileIndex tile, bool sound)
01709 {
01710   assert(IsLevelCrossingTile(tile));
01711 
01712   /* train on crossing || train approaching crossing || reserved */
01713   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || GetCrossingReservation(tile);
01714 
01715   if (new_state != IsCrossingBarred(tile)) {
01716     if (new_state && sound) {
01717       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01718     }
01719     SetCrossingBarred(tile, new_state);
01720     MarkTileDirtyByTile(tile);
01721   }
01722 }
01723 
01724 
01730 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01731 {
01732   if (!IsCrossingBarred(tile)) {
01733     BarCrossing(tile);
01734     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01735     MarkTileDirtyByTile(tile);
01736   }
01737 }
01738 
01739 
01745 static void AdvanceWagonsBeforeSwap(Vehicle *v)
01746 {
01747   Vehicle *base = v;
01748   Vehicle *first = base;                    // first vehicle to move
01749   Vehicle *last = GetLastVehicleInChain(v); // last vehicle to move
01750   uint length = CountVehiclesInChain(v);
01751 
01752   while (length > 2) {
01753     last = last->Previous();
01754     first = first->Next();
01755 
01756     int differential = base->u.rail.cached_veh_length - last->u.rail.cached_veh_length;
01757 
01758     /* do not update images now
01759      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01760     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01761 
01762     base = first; // == base->Next()
01763     length -= 2;
01764   }
01765 }
01766 
01767 
01773 static void AdvanceWagonsAfterSwap(Vehicle *v)
01774 {
01775   /* first of all, fix the situation when the train was entering a depot */
01776   Vehicle *dep = v; // last vehicle in front of just left depot
01777   while (dep->Next() != NULL && (dep->u.rail.track == TRACK_BIT_DEPOT || dep->Next()->u.rail.track != TRACK_BIT_DEPOT)) {
01778     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01779   }
01780 
01781   Vehicle *leave = dep->Next(); // first vehicle in a depot we are leaving now
01782 
01783   if (leave != NULL) {
01784     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01785     int d = TicksToLeaveDepot(dep);
01786 
01787     if (d <= 0) {
01788       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01789       leave->u.rail.track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01790       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01791     }
01792   } else {
01793     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01794   }
01795 
01796   Vehicle *base = v;
01797   Vehicle *first = base;                    // first vehicle to move
01798   Vehicle *last = GetLastVehicleInChain(v); // last vehicle to move
01799   uint length = CountVehiclesInChain(v);
01800 
01801   /* we have to make sure all wagons that leave a depot because of train reversing are moved coorectly
01802    * they have already correct spacing, so we have to make sure they are moved how they should */
01803   bool nomove = (dep == NULL); // if there is no vehicle leaving a depot, limit the number of wagons moved immediatelly
01804 
01805   while (length > 2) {
01806     /* we reached vehicle (originally) in front of a depot, stop now
01807      * (we would move wagons that are alredy moved with new wagon length) */
01808     if (base == dep) break;
01809 
01810     /* the last wagon was that one leaving a depot, so do not move it anymore */
01811     if (last == dep) nomove = true;
01812 
01813     last = last->Previous();
01814     first = first->Next();
01815 
01816     int differential = last->u.rail.cached_veh_length - base->u.rail.cached_veh_length;
01817 
01818     /* do not update images now */
01819     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01820 
01821     base = first; // == base->Next()
01822     length -= 2;
01823   }
01824 }
01825 
01826 
01827 static void ReverseTrainDirection(Vehicle *v)
01828 {
01829   if (IsRailDepotTile(v->tile)) {
01830     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01831   }
01832 
01833   /* Clear path reservation in front if train is not stuck. */
01834   if (!HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
01835 
01836   /* Check if we were approaching a rail/road-crossing */
01837   TileIndex crossing = TrainApproachingCrossingTile(v);
01838 
01839   /* count number of vehicles */
01840   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01841 
01842   AdvanceWagonsBeforeSwap(v);
01843 
01844   /* swap start<>end, start+1<>end-1, ... */
01845   int l = 0;
01846   do {
01847     ReverseTrainSwapVeh(v, l++, r--);
01848   } while (l <= r);
01849 
01850   AdvanceWagonsAfterSwap(v);
01851 
01852   if (IsRailDepotTile(v->tile)) {
01853     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01854   }
01855 
01856   ToggleBit(v->u.rail.flags, VRF_TOGGLE_REVERSE);
01857 
01858   ClrBit(v->u.rail.flags, VRF_REVERSING);
01859 
01860   /* recalculate cached data */
01861   TrainConsistChanged(v, true);
01862 
01863   /* update all images */
01864   for (Vehicle *u = v; u != NULL; u = u->Next()) u->UpdateViewport(false, false);
01865 
01866   /* update crossing we were approaching */
01867   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01868 
01869   /* maybe we are approaching crossing now, after reversal */
01870   crossing = TrainApproachingCrossingTile(v);
01871   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01872 
01873   /* If we are inside a depot after reversing, don't bother with path reserving. */
01874   if (v->u.rail.track & TRACK_BIT_DEPOT) {
01875     /* Can't be stuck here as inside a depot is always a safe tile. */
01876     if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01877     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01878     return;
01879   }
01880 
01881   /* TrainExitDir does not always produce the desired dir for depots and
01882    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01883   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
01884   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01885 
01886   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01887     /* If we are currently on a tile with conventional signals, we can't treat the
01888      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01889     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01890       HasSignalOnTrackdir(v->tile, GetVehicleTrackdir(v)) &&
01891       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->u.rail.track))));
01892 
01893     if (IsRailwayStationTile(v->tile)) SetRailwayStationPlatformReservation(v->tile, TrackdirToExitdir(GetVehicleTrackdir(v)), true);
01894     if (TryPathReserve(v, false, first_tile_okay)) {
01895       /* Do a look-ahead now in case our current tile was already a safe tile. */
01896       CheckNextTrainTile(v);
01897     } else if (v->current_order.GetType() != OT_LOADING) {
01898       /* Do not wait for a way out when we're still loading */
01899       MarkTrainAsStuck(v);
01900     }
01901   } else if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
01902     /* A train not inside a PBS block can't be stuck. */
01903     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01904     v->load_unload_time_rem = 0;
01905   }
01906 }
01907 
01914 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01915 {
01916   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01917 
01918   Vehicle *v = GetVehicle(p1);
01919 
01920   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01921 
01922   if (p2 != 0) {
01923     /* turn a single unit around */
01924 
01925     if (IsMultiheaded(v) || HasBit(EngInfo(v->engine_type)->callbackmask, CBM_VEHICLE_ARTIC_ENGINE)) {
01926       return_cmd_error(STR_ERROR_CAN_T_REVERSE_DIRECTION_RAIL_VEHICLE_MULTIPLE_UNITS);
01927     }
01928 
01929     Vehicle *front = v->First();
01930     /* make sure the vehicle is stopped in the depot */
01931     if (CheckTrainStoppedInDepot(front) < 0) {
01932       return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01933     }
01934 
01935     if (flags & DC_EXEC) {
01936       ToggleBit(v->u.rail.flags, VRF_REVERSE_DIRECTION);
01937       InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
01938       InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
01939     }
01940   } else {
01941     /* turn the whole train around */
01942     if (v->vehstatus & VS_CRASHED || v->breakdown_ctr != 0) return CMD_ERROR;
01943 
01944     if (flags & DC_EXEC) {
01945       /* Properly leave the station if we are loading and won't be loading anymore */
01946       if (v->current_order.IsType(OT_LOADING)) {
01947         const Vehicle *last = v;
01948         while (last->Next() != NULL) last = last->Next();
01949 
01950         /* not a station || different station --> leave the station */
01951         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01952           v->LeaveStation();
01953         }
01954       }
01955 
01956       if (_settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL && v->cur_speed != 0) {
01957         ToggleBit(v->u.rail.flags, VRF_REVERSING);
01958       } else {
01959         v->cur_speed = 0;
01960         SetLastSpeed(v, 0);
01961         HideFillingPercent(&v->fill_percent_te_id);
01962         ReverseTrainDirection(v);
01963       }
01964     }
01965   }
01966   return CommandCost();
01967 }
01968 
01975 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01976 {
01977   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01978 
01979   Vehicle *v = GetVehicle(p1);
01980 
01981   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01982 
01983   if (flags & DC_EXEC) v->u.rail.force_proceed = 0x50;
01984 
01985   return CommandCost();
01986 }
01987 
01998 CommandCost CmdRefitRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01999 {
02000   CargoID new_cid = GB(p2, 0, 8);
02001   byte new_subtype = GB(p2, 8, 8);
02002   bool only_this = HasBit(p2, 16);
02003 
02004   if (!IsValidVehicleID(p1)) return CMD_ERROR;
02005 
02006   Vehicle *v = GetVehicle(p1);
02007 
02008   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
02009   if (CheckTrainStoppedInDepot(v) < 0) return_cmd_error(STR_TRAIN_MUST_BE_STOPPED);
02010   if (v->vehstatus & VS_CRASHED) return_cmd_error(STR_CAN_T_REFIT_DESTROYED_VEHICLE);
02011 
02012   /* Check cargo */
02013   if (new_cid >= NUM_CARGO) return CMD_ERROR;
02014 
02015   CommandCost cost(EXPENSES_TRAIN_RUN);
02016   uint num = 0;
02017 
02018   do {
02019     /* XXX: We also refit all the attached wagons en-masse if they
02020      * can be refitted. This is how TTDPatch does it.  TODO: Have
02021      * some nice [Refit] button near each wagon. --pasky */
02022     if (!CanRefitTo(v->engine_type, new_cid)) continue;
02023 
02024     const Engine *e = GetEngine(v->engine_type);
02025     if (e->CanCarryCargo()) {
02026       uint16 amount = CALLBACK_FAILED;
02027 
02028       if (HasBit(EngInfo(v->engine_type)->callbackmask, CBM_VEHICLE_REFIT_CAPACITY)) {
02029         /* Back up the vehicle's cargo type */
02030         CargoID temp_cid = v->cargo_type;
02031         byte temp_subtype = v->cargo_subtype;
02032         v->cargo_type = new_cid;
02033         v->cargo_subtype = new_subtype;
02034         /* Check the refit capacity callback */
02035         amount = GetVehicleCallback(CBID_VEHICLE_REFIT_CAPACITY, 0, 0, v->engine_type, v);
02036         /* Restore the original cargo type */
02037         v->cargo_type = temp_cid;
02038         v->cargo_subtype = temp_subtype;
02039       }
02040 
02041       if (amount == CALLBACK_FAILED) { // callback failed or not used, use default
02042         CargoID old_cid = e->GetDefaultCargoType();
02043         /* normally, the capacity depends on the cargo type, a rail vehicle can
02044          * carry twice as much mail/goods as normal cargo, and four times as
02045          * many passengers
02046          */
02047         amount = e->u.rail.capacity;
02048         switch (old_cid) {
02049           case CT_PASSENGERS: break;
02050           case CT_MAIL:
02051           case CT_GOODS: amount *= 2; break;
02052           default:       amount *= 4; break;
02053         }
02054         switch (new_cid) {
02055           case CT_PASSENGERS: break;
02056           case CT_MAIL:
02057           case CT_GOODS: amount /= 2; break;
02058           default:       amount /= 4; break;
02059         }
02060       }
02061 
02062       if (new_cid != v->cargo_type) {
02063         cost.AddCost(GetRefitCost(v->engine_type));
02064       }
02065 
02066       num += amount;
02067       if (flags & DC_EXEC) {
02068         v->cargo.Truncate((v->cargo_type == new_cid) ? amount : 0);
02069         v->cargo_type = new_cid;
02070         v->cargo_cap = amount;
02071         v->cargo_subtype = new_subtype;
02072         InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
02073         InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
02074         InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
02075       }
02076     }
02077   } while ((v = v->Next()) != NULL && !only_this);
02078 
02079   _returned_refit_capacity = num;
02080 
02081   /* Update the train's cached variables */
02082   if (flags & DC_EXEC) TrainConsistChanged(GetVehicle(p1)->First(), false);
02083 
02084   return cost;
02085 }
02086 
02087 struct TrainFindDepotData {
02088   uint best_length;
02089   TileIndex tile;
02090   Owner owner;
02095   bool reverse;
02096 };
02097 
02098 static bool NtpCallbFindDepot(TileIndex tile, TrainFindDepotData *tfdd, int track, uint length)
02099 {
02100   if (IsTileType(tile, MP_RAILWAY) &&
02101       IsTileOwner(tile, tfdd->owner) &&
02102       IsRailDepot(tile)) {
02103     /* approximate number of tiles by dividing by DIAG_FACTOR */
02104     tfdd->best_length = length / DIAG_FACTOR;
02105     tfdd->tile = tile;
02106     return true;
02107   }
02108 
02109   return false;
02110 }
02111 
02114 static TrainFindDepotData FindClosestTrainDepot(Vehicle *v, int max_distance)
02115 {
02116   assert(!(v->vehstatus & VS_CRASHED));
02117 
02118   TrainFindDepotData tfdd;
02119   tfdd.owner = v->owner;
02120   tfdd.reverse = false;
02121 
02122   if (IsRailDepotTile(v->tile)) {
02123     tfdd.tile = v->tile;
02124     tfdd.best_length = 0;
02125     return tfdd;
02126   }
02127 
02128   PBSTileInfo origin = FollowTrainReservation(v);
02129   if (IsRailDepotTile(origin.tile)) {
02130     tfdd.tile = origin.tile;
02131     tfdd.best_length = 0;
02132     return tfdd;
02133   }
02134 
02135   tfdd.best_length = UINT_MAX;
02136 
02137   uint8 pathfinder = _settings_game.pf.pathfinder_for_trains;
02138   if ((_settings_game.pf.reserve_paths || HasReservedTracks(v->tile, v->u.rail.track)) && pathfinder == VPF_NTP) pathfinder = VPF_NPF;
02139 
02140   switch (pathfinder) {
02141     case VPF_YAPF: { // YAPF
02142       bool found = YapfFindNearestRailDepotTwoWay(v, max_distance, NPF_INFINITE_PENALTY, &tfdd.tile, &tfdd.reverse);
02143       tfdd.best_length = found ? max_distance / 2 : UINT_MAX; // some fake distance or NOT_FOUND
02144     } break;
02145 
02146     case VPF_NPF: { // NPF
02147       const Vehicle *last = GetLastVehicleInChain(v);
02148       Trackdir trackdir = GetVehicleTrackdir(v);
02149       Trackdir trackdir_rev = ReverseTrackdir(GetVehicleTrackdir(last));
02150 
02151       assert(trackdir != INVALID_TRACKDIR);
02152       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);
02153       if (ftd.best_bird_dist == 0) {
02154         /* Found target */
02155         tfdd.tile = ftd.node.tile;
02156         /* Our caller expects a number of tiles, so we just approximate that
02157          * number by this. It might not be completely what we want, but it will
02158          * work for now :-) We can possibly change this when the old pathfinder
02159          * is removed. */
02160         tfdd.best_length = ftd.best_path_dist / NPF_TILE_LENGTH;
02161         if (NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE)) tfdd.reverse = true;
02162       }
02163     } break;
02164 
02165     default:
02166     case VPF_NTP: { // NTP
02167       /* search in the forward direction first. */
02168       DiagDirection i = TrainExitDir(v->direction, v->u.rail.track);
02169       NewTrainPathfind(v->tile, 0, v->u.rail.compatible_railtypes, i, (NTPEnumProc*)NtpCallbFindDepot, &tfdd);
02170       if (tfdd.best_length == UINT_MAX){
02171         tfdd.reverse = true;
02172         /* search in backwards direction */
02173         i = TrainExitDir(ReverseDir(v->direction), v->u.rail.track);
02174         NewTrainPathfind(v->tile, 0, v->u.rail.compatible_railtypes, i, (NTPEnumProc*)NtpCallbFindDepot, &tfdd);
02175       }
02176     } break;
02177   }
02178 
02179   return tfdd;
02180 }
02181 
02182 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
02183 {
02184   TrainFindDepotData tfdd = FindClosestTrainDepot(this, 0);
02185   if (tfdd.best_length == UINT_MAX) return false;
02186 
02187   if (location    != NULL) *location    = tfdd.tile;
02188   if (destination != NULL) *destination = GetDepotByTile(tfdd.tile)->index;
02189   if (reverse     != NULL) *reverse     = tfdd.reverse;
02190 
02191   return true;
02192 }
02193 
02202 CommandCost CmdSendTrainToDepot(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
02203 {
02204   if (p2 & DEPOT_MASS_SEND) {
02205     /* Mass goto depot requested */
02206     if (!ValidVLWFlags(p2 & VLW_MASK)) return CMD_ERROR;
02207     return SendAllVehiclesToDepot(VEH_TRAIN, flags, p2 & DEPOT_SERVICE, _current_company, (p2 & VLW_MASK), p1);
02208   }
02209 
02210   if (!IsValidVehicleID(p1)) return CMD_ERROR;
02211 
02212   Vehicle *v = GetVehicle(p1);
02213 
02214   if (v->type != VEH_TRAIN) return CMD_ERROR;
02215 
02216   return v->SendToDepot(flags, (DepotCommand)(p2 & DEPOT_COMMAND_MASK));
02217 }
02218 
02219 
02220 void OnTick_Train()
02221 {
02222   _age_cargo_skip_counter = (_age_cargo_skip_counter == 0) ? 184 : (_age_cargo_skip_counter - 1);
02223 }
02224 
02225 static const int8 _vehicle_smoke_pos[8] = {
02226   1, 1, 1, 0, -1, -1, -1, 0
02227 };
02228 
02229 static void HandleLocomotiveSmokeCloud(const Vehicle *v)
02230 {
02231   bool sound = false;
02232 
02233   if (v->vehstatus & VS_TRAIN_SLOWING || v->load_unload_time_rem != 0 || v->cur_speed < 2) {
02234     return;
02235   }
02236 
02237   const Vehicle *u = v;
02238 
02239   do {
02240     const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
02241     int effect_offset = GB(v->u.rail.cached_vis_effect, 0, 4) - 8;
02242     byte effect_type = GB(v->u.rail.cached_vis_effect, 4, 2);
02243     bool disable_effect = HasBit(v->u.rail.cached_vis_effect, 6);
02244 
02245     /* no smoke? */
02246     if ((rvi->railveh_type == RAILVEH_WAGON && effect_type == 0) ||
02247         disable_effect ||
02248         v->vehstatus & VS_HIDDEN) {
02249       continue;
02250     }
02251 
02252     /* No smoke in depots or tunnels */
02253     if (IsRailDepotTile(v->tile) || IsTunnelTile(v->tile)) continue;
02254 
02255     /* No sparks for electric vehicles on nonelectrified tracks */
02256     if (!HasPowerOnRail(v->u.rail.railtype, GetTileRailType(v->tile))) continue;
02257 
02258     if (effect_type == 0) {
02259       /* Use default effect type for engine class. */
02260       effect_type = rvi->engclass;
02261     } else {
02262       effect_type--;
02263     }
02264 
02265     int x = _vehicle_smoke_pos[v->direction] * effect_offset;
02266     int y = _vehicle_smoke_pos[(v->direction + 2) % 8] * effect_offset;
02267 
02268     if (HasBit(v->u.rail.flags, VRF_REVERSE_DIRECTION)) {
02269       x = -x;
02270       y = -y;
02271     }
02272 
02273     switch (effect_type) {
02274       case 0:
02275         /* steam smoke. */
02276         if (GB(v->tick_counter, 0, 4) == 0) {
02277           CreateEffectVehicleRel(v, x, y, 10, EV_STEAM_SMOKE);
02278           sound = true;
02279         }
02280         break;
02281 
02282       case 1:
02283         /* diesel smoke */
02284         if (u->cur_speed <= 40 && Chance16(15, 128)) {
02285           CreateEffectVehicleRel(v, 0, 0, 10, EV_DIESEL_SMOKE);
02286           sound = true;
02287         }
02288         break;
02289 
02290       case 2:
02291         /* blue spark */
02292         if (GB(v->tick_counter, 0, 2) == 0 && Chance16(1, 45)) {
02293           CreateEffectVehicleRel(v, 0, 0, 10, EV_ELECTRIC_SPARK);
02294           sound = true;
02295         }
02296         break;
02297 
02298       default:
02299         break;
02300     }
02301   } while ((v = v->Next()) != NULL);
02302 
02303   if (sound) PlayVehicleSound(u, VSE_TRAIN_EFFECT);
02304 }
02305 
02306 void Train::PlayLeaveStationSound() const
02307 {
02308   static const SoundFx sfx[] = {
02309     SND_04_TRAIN,
02310     SND_0A_TRAIN_HORN,
02311     SND_0A_TRAIN_HORN,
02312     SND_47_MAGLEV_2,
02313     SND_41_MAGLEV
02314   };
02315 
02316   if (PlayVehicleSound(this, VSE_START)) return;
02317 
02318   EngineID engtype = this->engine_type;
02319   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02320 }
02321 
02323 static void CheckNextTrainTile(Vehicle *v)
02324 {
02325   /* Don't do any look-ahead if path_backoff_interval is 255. */
02326   if (_settings_game.pf.path_backoff_interval == 255) return;
02327 
02328   /* Exit if we reached our destination depot or are inside a depot. */
02329   if ((v->tile == v->dest_tile && v->current_order.IsType(OT_GOTO_DEPOT)) || v->u.rail.track & TRACK_BIT_DEPOT) return;
02330   /* Exit if we are on a station tile and are going to stop. */
02331   if (IsRailwayStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02332   /* Exit if the current order doesn't have a destination, but the train has orders. */
02333   if ((v->current_order.IsType(OT_NOTHING) || v->current_order.IsType(OT_LEAVESTATION) || v->current_order.IsType(OT_LOADING)) && v->GetNumOrders() > 0) return;
02334 
02335   Trackdir td = GetVehicleTrackdir(v);
02336 
02337   /* On a tile with a red non-pbs signal, don't look ahead. */
02338   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02339       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02340       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02341 
02342   CFollowTrackRail ft(v);
02343   if (!ft.Follow(v->tile, td)) return;
02344 
02345   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02346     /* Next tile is not reserved. */
02347     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02348       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02349         /* If the next tile is a PBS signal, try to make a reservation. */
02350         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02351         if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
02352           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02353         }
02354         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02355       }
02356     }
02357   }
02358 }
02359 
02360 static bool CheckTrainStayInDepot(Vehicle *v)
02361 {
02362   /* bail out if not all wagons are in the same depot or not in a depot at all */
02363   for (const Vehicle *u = v; u != NULL; u = u->Next()) {
02364     if (u->u.rail.track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02365   }
02366 
02367   /* if the train got no power, then keep it in the depot */
02368   if (v->u.rail.cached_power == 0) {
02369     v->vehstatus |= VS_STOPPED;
02370     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
02371     return true;
02372   }
02373 
02374   SigSegState seg_state;
02375 
02376   if (v->u.rail.force_proceed == 0) {
02377     /* force proceed was not pressed */
02378     if (++v->load_unload_time_rem < 37) {
02379       InvalidateWindowClasses(WC_TRAINS_LIST);
02380       return true;
02381     }
02382 
02383     v->load_unload_time_rem = 0;
02384 
02385     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02386     if (seg_state == SIGSEG_FULL || GetDepotWaypointReservation(v->tile)) {
02387       /* Full and no PBS signal in block or depot reserved, can't exit. */
02388       InvalidateWindowClasses(WC_TRAINS_LIST);
02389       return true;
02390     }
02391   } else {
02392     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02393   }
02394 
02395   /* We are leaving a depot, but have to go to the exact same one; re-enter */
02396   if (v->current_order.IsType(OT_GOTO_DEPOT) && v->tile == v->dest_tile) {
02397     /* We need to have a reservation for this to work. */
02398     if (GetDepotWaypointReservation(v->tile)) return true;
02399     SetDepotWaypointReservation(v->tile, true);
02400     VehicleEnterDepot(v);
02401     return true;
02402   }
02403 
02404   /* Only leave when we can reserve a path to our destination. */
02405   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->u.rail.force_proceed == 0) {
02406     /* No path and no force proceed. */
02407     InvalidateWindowClasses(WC_TRAINS_LIST);
02408     MarkTrainAsStuck(v);
02409     return true;
02410   }
02411 
02412   SetDepotWaypointReservation(v->tile, true);
02413   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02414 
02415   VehicleServiceInDepot(v);
02416   InvalidateWindowClasses(WC_TRAINS_LIST);
02417   v->PlayLeaveStationSound();
02418 
02419   v->u.rail.track = TRACK_BIT_X;
02420   if (v->direction & 2) v->u.rail.track = TRACK_BIT_Y;
02421 
02422   v->vehstatus &= ~VS_HIDDEN;
02423   v->cur_speed = 0;
02424 
02425   v->UpdateDeltaXY(v->direction);
02426   v->cur_image = v->GetImage(v->direction);
02427   VehicleMove(v, false);
02428   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02429   UpdateTrainAcceleration(v);
02430   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02431 
02432   return false;
02433 }
02434 
02436 static void ClearPathReservation(const Vehicle *v, TileIndex tile, Trackdir track_dir)
02437 {
02438   DiagDirection dir = TrackdirToExitdir(track_dir);
02439 
02440   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02441     /* Are we just leaving a tunnel/bridge? */
02442     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02443       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02444 
02445       if (!HasVehicleOnTunnelBridge(tile, end, v)) {
02446         /* Free the reservation only if no other train is on the tiles. */
02447         SetTunnelBridgeReservation(tile, false);
02448         SetTunnelBridgeReservation(end, false);
02449 
02450         if (_settings_client.gui.show_track_reservation) {
02451           MarkTileDirtyByTile(tile);
02452           MarkTileDirtyByTile(end);
02453         }
02454       }
02455     }
02456   } else if (IsRailwayStationTile(tile)) {
02457     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02458     /* If the new tile is not a further tile of the same station, we
02459      * clear the reservation for the whole platform. */
02460     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02461       SetRailwayStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02462     }
02463   } else {
02464     /* Any other tile */
02465     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02466   }
02467 }
02468 
02470 void FreeTrainTrackReservation(const Vehicle *v, TileIndex origin, Trackdir orig_td)
02471 {
02472   assert(IsFrontEngine(v));
02473 
02474   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02475   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : GetVehicleTrackdir(v);
02476   bool      free_tile = tile != v->tile || !(IsRailwayStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02477   StationID station_id = IsRailwayStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02478 
02479   /* Don't free reservation if it's not ours. */
02480   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02481 
02482   CFollowTrackRail ft(v, GetRailTypeInfo(v->u.rail.railtype)->compatible_railtypes);
02483   while (ft.Follow(tile, td)) {
02484     tile = ft.m_new_tile;
02485     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02486     td = RemoveFirstTrackdir(&bits);
02487     assert(bits == TRACKDIR_BIT_NONE);
02488 
02489     if (!IsValidTrackdir(td)) break;
02490 
02491     if (IsTileType(tile, MP_RAILWAY)) {
02492       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02493         /* Conventional signal along trackdir: remove reservation and stop. */
02494         UnreserveRailTrack(tile, TrackdirToTrack(td));
02495         break;
02496       }
02497       if (HasPbsSignalOnTrackdir(tile, td)) {
02498         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02499           /* Red PBS signal? Can't be our reservation, would be green then. */
02500           break;
02501         } else {
02502           /* Turn the signal back to red. */
02503           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02504           MarkTileDirtyByTile(tile);
02505         }
02506       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02507         break;
02508       }
02509     }
02510 
02511     /* Don't free first station/bridge/tunnel if we are on it. */
02512     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);
02513 
02514     free_tile = true;
02515   }
02516 }
02517 
02519 struct TrainTrackFollowerData {
02520   TileIndex dest_coords;
02521   StationID station_index; 
02522   uint best_bird_dist;
02523   uint best_track_dist;
02524   TrackdirByte best_track;
02525 };
02526 
02527 static bool NtpCallbFindStation(TileIndex tile, TrainTrackFollowerData *ttfd, Trackdir track, uint length)
02528 {
02529   /* heading for nowhere? */
02530   if (ttfd->dest_coords == 0) return false;
02531 
02532   /* did we reach the final station? */
02533   if ((ttfd->station_index == INVALID_STATION && tile == ttfd->dest_coords) || (
02534         IsTileType(tile, MP_STATION) &&
02535         IsRailwayStation(tile) &&
02536         GetStationIndex(tile) == ttfd->station_index
02537       )) {
02538     /* We do not check for dest_coords if we have a station_index,
02539      * because in that case the dest_coords are just an
02540      * approximation of where the station is */
02541 
02542     /* found station */
02543     ttfd->best_track = track;
02544     ttfd->best_bird_dist = 0;
02545     return true;
02546   } else {
02547     /* didn't find station, keep track of the best path so far. */
02548     uint dist = DistanceManhattan(tile, ttfd->dest_coords);
02549     if (dist < ttfd->best_bird_dist) {
02550       ttfd->best_bird_dist = dist;
02551       ttfd->best_track = track;
02552     }
02553     return false;
02554   }
02555 }
02556 
02557 static void FillWithStationData(TrainTrackFollowerData *fd, const Vehicle *v)
02558 {
02559   fd->dest_coords = v->dest_tile;
02560   fd->station_index = v->current_order.IsType(OT_GOTO_STATION) ? v->current_order.GetDestination() : INVALID_STATION;
02561 }
02562 
02563 static const byte _initial_tile_subcoord[6][4][3] = {
02564 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02565 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02566 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02567 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02568 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02569 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02570 };
02571 
02572 static const byte _search_directions[6][4] = {
02573   { 0, 9, 2, 9 }, 
02574   { 9, 1, 9, 3 }, 
02575   { 9, 0, 3, 9 }, 
02576   { 1, 9, 9, 2 }, 
02577   { 3, 2, 9, 9 }, 
02578   { 9, 9, 1, 0 }, 
02579 };
02580 
02581 static const byte _pick_track_table[6] = {1, 3, 2, 2, 0, 0};
02582 
02595 static Track DoTrainPathfind(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool do_track_reservation, PBSTileInfo *dest)
02596 {
02597   Track best_track;
02598 
02599 #ifdef PF_BENCHMARK
02600   TIC()
02601 #endif
02602 
02603   if (path_not_found) *path_not_found = false;
02604 
02605   uint8 pathfinder = _settings_game.pf.pathfinder_for_trains;
02606   if (do_track_reservation && pathfinder == VPF_NTP) pathfinder = VPF_NPF;
02607 
02608   switch (pathfinder) {
02609     case VPF_YAPF: { // YAPF
02610       Trackdir trackdir = YapfChooseRailTrack(v, tile, enterdir, tracks, path_not_found, do_track_reservation, dest);
02611       if (trackdir != INVALID_TRACKDIR) {
02612         best_track = TrackdirToTrack(trackdir);
02613       } else {
02614         best_track = FindFirstTrack(tracks);
02615       }
02616     } break;
02617 
02618     case VPF_NPF: { // NPF
02619       void *perf = NpfBeginInterval();
02620 
02621       NPFFindStationOrTileData fstd;
02622       NPFFillWithOrderData(&fstd, v, do_track_reservation);
02623 
02624       PBSTileInfo origin = FollowTrainReservation(v);
02625       assert(IsValidTrackdir(origin.trackdir));
02626 
02627       NPFFoundTargetData ftd = NPFRouteToStationOrTile(origin.tile, origin.trackdir, true, &fstd, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes);
02628 
02629       if (dest != NULL) {
02630         dest->tile = ftd.node.tile;
02631         dest->trackdir = (Trackdir)ftd.node.direction;
02632         dest->okay = ftd.res_okay;
02633       }
02634 
02635       if (ftd.best_trackdir == INVALID_TRACKDIR) {
02636         /* We are already at our target. Just do something
02637          * @todo maybe display error?
02638          * @todo: go straight ahead if possible? */
02639         best_track = FindFirstTrack(tracks);
02640       } else {
02641         /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
02642          * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
02643          * we did not find our target, but ftd.best_trackdir contains the direction leading
02644          * to the tile closest to our target. */
02645         if (ftd.best_bird_dist != 0 && path_not_found != NULL) *path_not_found = true;
02646         /* Discard enterdir information, making it a normal track */
02647         best_track = TrackdirToTrack(ftd.best_trackdir);
02648       }
02649 
02650       int time = NpfEndInterval(perf);
02651       DEBUG(yapf, 4, "[NPFT] %d us - %d rounds - %d open - %d closed -- ", time, 0, _aystar_stats_open_size, _aystar_stats_closed_size);
02652     } break;
02653 
02654     default:
02655     case VPF_NTP: { // NTP
02656       void *perf = NpfBeginInterval();
02657 
02658       TrainTrackFollowerData fd;
02659       FillWithStationData(&fd, v);
02660 
02661       /* New train pathfinding */
02662       fd.best_bird_dist = UINT_MAX;
02663       fd.best_track_dist = UINT_MAX;
02664       fd.best_track = INVALID_TRACKDIR;
02665 
02666       NewTrainPathfind(tile - TileOffsByDiagDir(enterdir), v->dest_tile,
02667         v->u.rail.compatible_railtypes, enterdir, (NTPEnumProc*)NtpCallbFindStation, &fd);
02668 
02669       /* check whether the path was found or only 'guessed' */
02670       if (fd.best_bird_dist != 0 && path_not_found != NULL) *path_not_found = true;
02671 
02672       if (fd.best_track == INVALID_TRACKDIR) {
02673         /* blaha */
02674         best_track = FindFirstTrack(tracks);
02675       } else {
02676         best_track = TrackdirToTrack(fd.best_track);
02677       }
02678 
02679       int time = NpfEndInterval(perf);
02680       DEBUG(yapf, 4, "[NTPT] %d us - %d rounds - %d open - %d closed -- ", time, 0, 0, 0);
02681     } break;
02682   }
02683 
02684 #ifdef PF_BENCHMARK
02685   TOC("PF time = ", 1)
02686 #endif
02687 
02688   return best_track;
02689 }
02690 
02696 static PBSTileInfo ExtendTrainReservation(const Vehicle *v, TrackBits *new_tracks, DiagDirection *enterdir)
02697 {
02698   bool no_90deg_turns = _settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg;
02699   PBSTileInfo origin = FollowTrainReservation(v);
02700 
02701   CFollowTrackRail ft(v);
02702 
02703   TileIndex tile = origin.tile;
02704   Trackdir  cur_td = origin.trackdir;
02705   while (ft.Follow(tile, cur_td)) {
02706     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02707       /* Possible signal tile. */
02708       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02709     }
02710 
02711     if (no_90deg_turns) {
02712       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02713       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02714     }
02715 
02716     /* Station, depot or waypoint are a possible target. */
02717     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRail(ft.m_new_tile));
02718     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02719       /* Choice found or possible target encountered.
02720        * On finding a possible target, we need to stop and let the pathfinder handle the
02721        * remaining path. This is because we don't know if this target is in one of our
02722        * orders, so we might cause pathfinding to fail later on if we find a choice.
02723        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02724        * a wrong path not leading to our next destination. */
02725       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02726 
02727       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02728        * actually starts its search at the first unreserved tile. */
02729       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02730 
02731       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02732       if (new_tracks) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02733       if (enterdir) *enterdir = ft.m_exitdir;
02734       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02735     }
02736 
02737     tile = ft.m_new_tile;
02738     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02739 
02740     if (IsSafeWaitingPosition(v, tile, cur_td, true, no_90deg_turns)) {
02741       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, no_90deg_turns);
02742       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02743       /* Safe position is all good, path valid and okay. */
02744       return PBSTileInfo(tile, cur_td, true);
02745     }
02746 
02747     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02748   }
02749 
02750   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02751     /* End of line, path valid and okay. */
02752     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02753   }
02754 
02755   /* Sorry, can't reserve path, back out. */
02756   tile = origin.tile;
02757   cur_td = origin.trackdir;
02758   TileIndex stopped = ft.m_old_tile;
02759   Trackdir  stopped_td = ft.m_old_td;
02760   while (tile != stopped || cur_td != stopped_td) {
02761     if (!ft.Follow(tile, cur_td)) break;
02762 
02763     if (no_90deg_turns) {
02764       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02765       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02766     }
02767     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02768 
02769     tile = ft.m_new_tile;
02770     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02771 
02772     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02773   }
02774 
02775   /* Path invalid. */
02776   return PBSTileInfo();
02777 }
02778 
02789 static bool TryReserveSafeTrack(const Vehicle *v, TileIndex tile, Trackdir td, bool override_tailtype)
02790 {
02791   if (_settings_game.pf.pathfinder_for_trains == VPF_YAPF) {
02792     return YapfRailFindNearestSafeTile(v, tile, td, override_tailtype);
02793   } else {
02794     return NPFRouteToSafeTile(v, tile, td, override_tailtype).res_okay;
02795   }
02796 }
02797 
02799 class VehicleOrderSaver
02800 {
02801 private:
02802   Vehicle        *v;
02803   Order          old_order;
02804   TileIndex      old_dest_tile;
02805   StationID      old_last_station_visited;
02806   VehicleOrderID index;
02807 
02808 public:
02809   VehicleOrderSaver(Vehicle *_v) :
02810     v(_v),
02811     old_order(_v->current_order),
02812     old_dest_tile(_v->dest_tile),
02813     old_last_station_visited(_v->last_station_visited),
02814     index(_v->cur_order_index)
02815   {
02816   }
02817 
02818   ~VehicleOrderSaver()
02819   {
02820     this->v->current_order = this->old_order;
02821     this->v->dest_tile = this->old_dest_tile;
02822     this->v->last_station_visited = this->old_last_station_visited;
02823   }
02824 
02830   bool SwitchToNextOrder(bool skip_first)
02831   {
02832     if (this->v->GetNumOrders() == 0) return false;
02833 
02834     if (skip_first) ++this->index;
02835 
02836     int conditional_depth = 0;
02837 
02838     do {
02839       /* Wrap around. */
02840       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02841 
02842       Order *order = GetVehicleOrder(this->v, this->index);
02843       assert(order != NULL);
02844 
02845       switch (order->GetType()) {
02846         case OT_GOTO_DEPOT:
02847           /* Skip service in depot orders when the train doesn't need service. */
02848           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02849         case OT_GOTO_STATION:
02850         case OT_GOTO_WAYPOINT:
02851           this->v->current_order = *order;
02852           UpdateOrderDest(this->v, order);
02853           return true;
02854         case OT_CONDITIONAL: {
02855           if (conditional_depth > this->v->GetNumOrders()) return false;
02856           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02857           if (next != INVALID_VEH_ORDER_ID) {
02858             conditional_depth++;
02859             this->index = next;
02860             /* Don't increment next, so no break here. */
02861             continue;
02862           }
02863           break;
02864         }
02865         default:
02866           break;
02867       }
02868       /* Don't increment inside the while because otherwise conditional
02869        * orders can lead to an infinite loop. */
02870       ++this->index;
02871     } while (this->index != this->v->cur_order_index);
02872 
02873     return false;
02874   }
02875 };
02876 
02877 /* choose a track */
02878 static Track ChooseTrainTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02879 {
02880   Track best_track = INVALID_TRACK;
02881   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02882   bool changed_signal = false;
02883 
02884   assert((tracks & ~TRACK_BIT_MASK) == 0);
02885 
02886   if (got_reservation != NULL) *got_reservation = false;
02887 
02888   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02889   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02890   /* Do we have a suitable reserved track? */
02891   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02892 
02893   /* Quick return in case only one possible track is available */
02894   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02895     Track track = FindFirstTrack(tracks);
02896     /* We need to check for signals only here, as a junction tile can't have signals. */
02897     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02898       do_track_reservation = true;
02899       changed_signal = true;
02900       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02901     } else if (!do_track_reservation) {
02902       return track;
02903     }
02904     best_track = track;
02905   }
02906 
02907   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02908   DiagDirection dest_enterdir = enterdir;
02909   if (do_track_reservation) {
02910     /* Check if the train needs service here, so it has a chance to always find a depot.
02911      * Also check if the current order is a service order so we don't reserve a path to
02912      * the destination but instead to the next one if service isn't needed. */
02913     CheckIfTrainNeedsService(v);
02914     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02915 
02916     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02917     if (res_dest.tile == INVALID_TILE) {
02918       /* Reservation failed? */
02919       if (mark_stuck) MarkTrainAsStuck(v);
02920       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02921       return FindFirstTrack(tracks);
02922     }
02923   }
02924 
02925   /* Save the current train order. The destructor will restore the old order on function exit. */
02926   VehicleOrderSaver orders(v);
02927 
02928   /* If the current tile is the destination of the current order and
02929    * a reservation was requested, advance to the next order.
02930    * Don't advance on a depot order as depots are always safe end points
02931    * for a path and no look-ahead is necessary. This also avoids a
02932    * problem with depot orders not part of the order list when the
02933    * order list itself is empty. */
02934   if (v->current_order.IsType(OT_LEAVESTATION)) {
02935     orders.SwitchToNextOrder(false);
02936   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02937       v->current_order.IsType(OT_GOTO_STATION) ?
02938       IsRailwayStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02939       v->tile == v->dest_tile))) {
02940     orders.SwitchToNextOrder(true);
02941   }
02942 
02943   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02944     /* Pathfinders are able to tell that route was only 'guessed'. */
02945     bool      path_not_found = false;
02946     TileIndex new_tile = res_dest.tile;
02947 
02948     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, &path_not_found, do_track_reservation, &res_dest);
02949     if (new_tile == tile) best_track = next_track;
02950 
02951     /* handle "path not found" state */
02952     if (path_not_found) {
02953       /* PF didn't find the route */
02954       if (!HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
02955         /* it is first time the problem occurred, set the "path not found" flag */
02956         SetBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
02957         /* and notify user about the event */
02958         AI::NewEvent(v->owner, new AIEventVehicleLost(v->index));
02959         if (_settings_client.gui.lost_train_warn && v->owner == _local_company) {
02960           SetDParam(0, v->index);
02961           AddNewsItem(
02962             STR_TRAIN_IS_LOST,
02963             NS_ADVICE,
02964             v->index,
02965             0);
02966         }
02967       }
02968     } else {
02969       /* route found, is the train marked with "path not found" flag? */
02970       if (HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
02971         /* clear the flag as the PF's problem was solved */
02972         ClrBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
02973         /* can we also delete the "News" item somehow? */
02974       }
02975     }
02976   }
02977 
02978   /* No track reservation requested -> finished. */
02979   if (!do_track_reservation) return best_track;
02980 
02981   /* A path was found, but could not be reserved. */
02982   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02983     if (mark_stuck) MarkTrainAsStuck(v);
02984     FreeTrainTrackReservation(v);
02985     return best_track;
02986   }
02987 
02988   /* No possible reservation target found, we are probably lost. */
02989   if (res_dest.tile == INVALID_TILE) {
02990     /* Try to find any safe destination. */
02991     PBSTileInfo origin = FollowTrainReservation(v);
02992     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02993       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02994       best_track = FindFirstTrack(res);
02995       TryReserveRailTrack(v->tile, TrackdirToTrack(GetVehicleTrackdir(v)));
02996       if (got_reservation != NULL) *got_reservation = true;
02997       if (changed_signal) MarkTileDirtyByTile(tile);
02998     } else {
02999       FreeTrainTrackReservation(v);
03000       if (mark_stuck) MarkTrainAsStuck(v);
03001     }
03002     return best_track;
03003   }
03004 
03005   if (got_reservation != NULL) *got_reservation = true;
03006 
03007   /* Reservation target found and free, check if it is safe. */
03008   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
03009     /* Extend reservation until we have found a safe position. */
03010     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
03011     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
03012     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
03013     if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
03014       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
03015     }
03016 
03017     /* Get next order with destination. */
03018     if (orders.SwitchToNextOrder(true)) {
03019       PBSTileInfo cur_dest;
03020       DoTrainPathfind(v, next_tile, exitdir, reachable, NULL, true, &cur_dest);
03021       if (cur_dest.tile != INVALID_TILE) {
03022         res_dest = cur_dest;
03023         if (res_dest.okay) continue;
03024         /* Path found, but could not be reserved. */
03025         FreeTrainTrackReservation(v);
03026         if (mark_stuck) MarkTrainAsStuck(v);
03027         if (got_reservation != NULL) *got_reservation = false;
03028         changed_signal = false;
03029         break;
03030       }
03031     }
03032     /* No order or no safe position found, try any position. */
03033     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
03034       FreeTrainTrackReservation(v);
03035       if (mark_stuck) MarkTrainAsStuck(v);
03036       if (got_reservation != NULL) *got_reservation = false;
03037       changed_signal = false;
03038     }
03039     break;
03040   }
03041 
03042   TryReserveRailTrack(v->tile, TrackdirToTrack(GetVehicleTrackdir(v)));
03043 
03044   if (changed_signal) MarkTileDirtyByTile(tile);
03045 
03046   return best_track;
03047 }
03048 
03057 bool TryPathReserve(Vehicle *v, bool mark_as_stuck, bool first_tile_okay)
03058 {
03059   assert(v->type == VEH_TRAIN && IsFrontEngine(v));
03060 
03061   /* We have to handle depots specially as the track follower won't look
03062    * at the depot tile itself but starts from the next tile. If we are still
03063    * inside the depot, a depot reservation can never be ours. */
03064   if (v->u.rail.track & TRACK_BIT_DEPOT) {
03065     if (GetDepotWaypointReservation(v->tile)) {
03066       if (mark_as_stuck) MarkTrainAsStuck(v);
03067       return false;
03068     } else {
03069       /* Depot not reserved, but the next tile might be. */
03070       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
03071       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
03072     }
03073   }
03074 
03075   /* Special check if we are in front of a two-sided conventional signal. */
03076   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
03077   TileIndex next_tile = TileAddByDiagDir(v->tile, dir);
03078   if (IsTileType(next_tile, MP_RAILWAY) && HasReservedTracks(next_tile, DiagdirReachesTracks(dir))) {
03079     /* Can have only one reserved trackdir. */
03080     Trackdir td = FindFirstTrackdir(TrackBitsToTrackdirBits(GetReservedTrackbits(next_tile)) & DiagdirReachesTrackdirs(dir));
03081     if (HasSignalOnTrackdir(next_tile, td) && HasSignalOnTrackdir(next_tile, ReverseTrackdir(td)) &&
03082         !IsPbsSignal(GetSignalType(next_tile, TrackdirToTrack(td)))) {
03083       /* Signal already reserved, is not ours. */
03084       if (mark_as_stuck) MarkTrainAsStuck(v);
03085       return false;
03086     }
03087   }
03088 
03089   bool other_train = false;
03090   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
03091   /* The path we are driving on is alread blocked by some other train.
03092    * This can only happen in certain situations when mixing path and
03093    * block signals or when changing tracks and/or signals.
03094    * Exit here as doing any further reservations will probably just
03095    * make matters worse. */
03096   if (other_train && v->tile != origin.tile) {
03097     if (mark_as_stuck) MarkTrainAsStuck(v);
03098     return false;
03099   }
03100   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
03101   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
03102     /* Can't be stuck then. */
03103     if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03104     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
03105     return true;
03106   }
03107 
03108   /* If we are in a depot, tentativly reserve the depot. */
03109   if (v->u.rail.track & TRACK_BIT_DEPOT) {
03110     SetDepotWaypointReservation(v->tile, true);
03111     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
03112   }
03113 
03114   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
03115   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
03116   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
03117 
03118   if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
03119 
03120   bool res_made = false;
03121   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
03122 
03123   if (!res_made) {
03124     /* Free the depot reservation as well. */
03125     if (v->u.rail.track & TRACK_BIT_DEPOT) SetDepotWaypointReservation(v->tile, false);
03126     return false;
03127   }
03128 
03129   if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
03130     v->load_unload_time_rem = 0;
03131     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03132   }
03133   ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
03134   return true;
03135 }
03136 
03137 
03138 static bool CheckReverseTrain(Vehicle *v)
03139 {
03140   if (_settings_game.difficulty.line_reverse_mode != 0 ||
03141       v->u.rail.track == TRACK_BIT_DEPOT || v->u.rail.track == TRACK_BIT_WORMHOLE ||
03142       !(v->direction & 1)) {
03143     return false;
03144   }
03145 
03146   uint reverse_best = 0;
03147 
03148   assert(v->u.rail.track);
03149 
03150   switch (_settings_game.pf.pathfinder_for_trains) {
03151     case VPF_YAPF: // YAPF
03152       reverse_best = YapfCheckReverseTrain(v);
03153       break;
03154 
03155     case VPF_NPF: { // NPF
03156       NPFFindStationOrTileData fstd;
03157       NPFFoundTargetData ftd;
03158       Vehicle *last = GetLastVehicleInChain(v);
03159 
03160       NPFFillWithOrderData(&fstd, v);
03161 
03162       Trackdir trackdir = GetVehicleTrackdir(v);
03163       Trackdir trackdir_rev = ReverseTrackdir(GetVehicleTrackdir(last));
03164       assert(trackdir != INVALID_TRACKDIR);
03165       assert(trackdir_rev != INVALID_TRACKDIR);
03166 
03167       ftd = NPFRouteToStationOrTileTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, &fstd, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes);
03168       if (ftd.best_bird_dist != 0) {
03169         /* We didn't find anything, just keep on going straight ahead */
03170         reverse_best = false;
03171       } else {
03172         if (NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE)) {
03173           reverse_best = true;
03174         } else {
03175           reverse_best = false;
03176         }
03177       }
03178     } break;
03179 
03180     default:
03181     case VPF_NTP: { // NTP
03182       TrainTrackFollowerData fd;
03183       FillWithStationData(&fd, v);
03184 
03185       int i = _search_directions[FindFirstTrack(v->u.rail.track)][DirToDiagDir(v->direction)];
03186 
03187       int best_track = -1;
03188       uint reverse = 0;
03189       uint best_bird_dist  = 0;
03190       uint best_track_dist = 0;
03191 
03192       for (;;) {
03193         fd.best_bird_dist = UINT_MAX;
03194         fd.best_track_dist = UINT_MAX;
03195 
03196         NewTrainPathfind(v->tile, v->dest_tile, v->u.rail.compatible_railtypes, (DiagDirection)(reverse ^ i), (NTPEnumProc*)NtpCallbFindStation, &fd);
03197 
03198         if (best_track != -1) {
03199           if (best_bird_dist != 0) {
03200             if (fd.best_bird_dist != 0) {
03201               /* neither reached the destination, pick the one with the smallest bird dist */
03202               if (fd.best_bird_dist > best_bird_dist) goto bad;
03203               if (fd.best_bird_dist < best_bird_dist) goto good;
03204             } else {
03205               /* we found the destination for the first time */
03206               goto good;
03207             }
03208           } else {
03209             if (fd.best_bird_dist != 0) {
03210               /* didn't find destination, but we've found the destination previously */
03211               goto bad;
03212             } else {
03213               /* both old & new reached the destination, compare track length */
03214               if (fd.best_track_dist > best_track_dist) goto bad;
03215               if (fd.best_track_dist < best_track_dist) goto good;
03216             }
03217           }
03218 
03219           /* if we reach this position, there's two paths of equal value so far.
03220            * pick one randomly. */
03221           int r = GB(Random(), 0, 8);
03222           if (_pick_track_table[i] == (v->direction & 3)) r += 80;
03223           if (_pick_track_table[best_track] == (v->direction & 3)) r -= 80;
03224           if (r <= 127) goto bad;
03225         }
03226 good:;
03227         best_track = i;
03228         best_bird_dist = fd.best_bird_dist;
03229         best_track_dist = fd.best_track_dist;
03230         reverse_best = reverse;
03231 bad:;
03232         if (reverse != 0) break;
03233         reverse = 2;
03234       }
03235     } break;
03236   }
03237 
03238   return reverse_best != 0;
03239 }
03240 
03241 TileIndex Train::GetOrderStationLocation(StationID station)
03242 {
03243   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
03244 
03245   const Station *st = GetStation(station);
03246   if (!(st->facilities & FACIL_TRAIN)) {
03247     /* The destination station has no trainstation tiles. */
03248     this->cur_order_index++;
03249     return 0;
03250   }
03251 
03252   return st->xy;
03253 }
03254 
03255 void Train::MarkDirty()
03256 {
03257   Vehicle *v = this;
03258   do {
03259     v->UpdateViewport(false, false);
03260   } while ((v = v->Next()) != NULL);
03261 
03262   /* need to update acceleration and cached values since the goods on the train changed. */
03263   TrainCargoChanged(this);
03264   UpdateTrainAcceleration(this);
03265 }
03266 
03277 static int UpdateTrainSpeed(Vehicle *v)
03278 {
03279   uint accel;
03280 
03281   if (v->vehstatus & VS_STOPPED || HasBit(v->u.rail.flags, VRF_REVERSING) || HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
03282     switch (_settings_game.vehicle.train_acceleration_model) {
03283       default: NOT_REACHED();
03284       case TAM_ORIGINAL:  accel = v->acceleration * -4; break;
03285       case TAM_REALISTIC: accel = GetTrainAcceleration(v, AM_BRAKE); break;
03286     }
03287   } else {
03288     switch (_settings_game.vehicle.train_acceleration_model) {
03289       default: NOT_REACHED();
03290       case TAM_ORIGINAL:  accel = v->acceleration * 2; break;
03291       case TAM_REALISTIC: accel = GetTrainAcceleration(v, AM_ACCEL); break;
03292     }
03293   }
03294 
03295   uint spd = v->subspeed + accel;
03296   v->subspeed = (byte)spd;
03297   {
03298     int tempmax = v->max_speed;
03299     if (v->cur_speed > v->max_speed)
03300       tempmax = v->cur_speed - (v->cur_speed / 10) - 1;
03301     v->cur_speed = spd = Clamp(v->cur_speed + ((int)spd >> 8), 0, tempmax);
03302   }
03303 
03304   /* Scale speed by 3/4. Previously this was only done when the train was
03305    * facing diagonally and would apply to however many moves the train made
03306    * regardless the of direction actually moved in. Now it is always scaled,
03307    * 256 spd is used to go straight and 192 is used to go diagonally
03308    * (3/4 of 256). This results in the same effect, but without the error the
03309    * previous method caused.
03310    *
03311    * The scaling is done in this direction and not by multiplying the amount
03312    * to be subtracted by 4/3 so that the leftover speed can be saved in a
03313    * byte in v->progress.
03314    */
03315   int scaled_spd = spd * 3 >> 2;
03316 
03317   scaled_spd += v->progress;
03318   v->progress = 0; // set later in TrainLocoHandler or TrainController
03319   return scaled_spd;
03320 }
03321 
03322 static void TrainEnterStation(Vehicle *v, StationID station)
03323 {
03324   v->last_station_visited = station;
03325 
03326   /* check if a train ever visited this station before */
03327   Station *st = GetStation(station);
03328   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
03329     st->had_vehicle_of_type |= HVOT_TRAIN;
03330     SetDParam(0, st->index);
03331     AddNewsItem(
03332       STR_8801_CITIZENS_CELEBRATE_FIRST,
03333       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
03334       v->index,
03335       st->index
03336     );
03337     AI::NewEvent(v->owner, new AIEventStationFirstVehicle(st->index, v->index));
03338   }
03339 
03340   v->BeginLoading();
03341 
03342   StationAnimationTrigger(st, v->tile, STAT_ANIM_TRAIN_ARRIVES);
03343 }
03344 
03345 static byte AfterSetTrainPos(Vehicle *v, bool new_tile)
03346 {
03347   byte old_z = v->z_pos;
03348   v->z_pos = GetSlopeZ(v->x_pos, v->y_pos);
03349 
03350   if (new_tile) {
03351     ClrBit(v->u.rail.flags, VRF_GOINGUP);
03352     ClrBit(v->u.rail.flags, VRF_GOINGDOWN);
03353 
03354     if (v->u.rail.track == TRACK_BIT_X || v->u.rail.track == TRACK_BIT_Y) {
03355       /* Any track that isn't TRACK_BIT_X or TRACK_BIT_Y cannot be sloped.
03356        * To check whether the current tile is sloped, and in which
03357        * direction it is sloped, we get the 'z' at the center of
03358        * the tile (middle_z) and the edge of the tile (old_z),
03359        * which we then can compare. */
03360       static const int HALF_TILE_SIZE = TILE_SIZE / 2;
03361       static const int INV_TILE_SIZE_MASK = ~(TILE_SIZE - 1);
03362 
03363       byte middle_z = GetSlopeZ((v->x_pos & INV_TILE_SIZE_MASK) | HALF_TILE_SIZE, (v->y_pos & INV_TILE_SIZE_MASK) | HALF_TILE_SIZE);
03364 
03365       /* For some reason tunnel tiles are always given as sloped :(
03366        * But they are not sloped... */
03367       if (middle_z != v->z_pos && !IsTunnelTile(TileVirtXY(v->x_pos, v->y_pos))) {
03368         SetBit(v->u.rail.flags, (middle_z > old_z) ? VRF_GOINGUP : VRF_GOINGDOWN);
03369       }
03370     }
03371   }
03372 
03373   VehicleMove(v, true);
03374   return old_z;
03375 }
03376 
03377 static const Direction _new_vehicle_direction_table[11] = {
03378   DIR_N , DIR_NW, DIR_W , INVALID_DIR,
03379   DIR_NE, DIR_N , DIR_SW, INVALID_DIR,
03380   DIR_E , DIR_SE, DIR_S
03381 };
03382 
03383 static inline Direction GetNewVehicleDirectionByTile(TileIndex new_tile, TileIndex old_tile)
03384 {
03385   uint offs = (TileY(new_tile) - TileY(old_tile) + 1) * 4 +
03386               TileX(new_tile) - TileX(old_tile) + 1;
03387   assert(offs < 11);
03388   return _new_vehicle_direction_table[offs];
03389 }
03390 
03391 static inline int GetDirectionToVehicle(const Vehicle *v, int x, int y)
03392 {
03393   byte offs;
03394 
03395   x -= v->x_pos;
03396   if (x >= 0) {
03397     offs = (x > 2) ? 0 : 1;
03398   } else {
03399     offs = (x < -2) ? 2 : 1;
03400   }
03401 
03402   y -= v->y_pos;
03403   if (y >= 0) {
03404     offs += ((y > 2) ? 0 : 1) * 4;
03405   } else {
03406     offs += ((y < -2) ? 2 : 1) * 4;
03407   }
03408 
03409   assert(offs < 11);
03410   return _new_vehicle_direction_table[offs];
03411 }
03412 
03413 /* Check if the vehicle is compatible with the specified tile */
03414 static inline bool CheckCompatibleRail(const Vehicle *v, TileIndex tile)
03415 {
03416   return
03417     IsTileOwner(tile, v->owner) && (
03418       !IsFrontEngine(v) ||
03419       HasBit(v->u.rail.compatible_railtypes, GetRailType(tile))
03420     );
03421 }
03422 
03423 struct RailtypeSlowdownParams {
03424   byte small_turn, large_turn;
03425   byte z_up; // fraction to remove when moving up
03426   byte z_down; // fraction to remove when moving down
03427 };
03428 
03429 static const RailtypeSlowdownParams _railtype_slowdown[] = {
03430   /* normal accel */
03431   {256 / 4, 256 / 2, 256 / 4, 2}, 
03432   {256 / 4, 256 / 2, 256 / 4, 2}, 
03433   {256 / 4, 256 / 2, 256 / 4, 2}, 
03434   {0,       256 / 2, 256 / 4, 2}, 
03435 };
03436 
03438 static inline void AffectSpeedByDirChange(Vehicle *v, Direction new_dir)
03439 {
03440   if (_settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL) return;
03441 
03442   DirDiff diff = DirDifference(v->direction, new_dir);
03443   if (diff == DIRDIFF_SAME) return;
03444 
03445   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->u.rail.railtype];
03446   v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03447 }
03448 
03450 static inline void AffectSpeedByZChange(Vehicle *v, byte old_z)
03451 {
03452   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL) return;
03453 
03454   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->u.rail.railtype];
03455 
03456   if (old_z < v->z_pos) {
03457     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
03458   } else {
03459     uint16 spd = v->cur_speed + rsp->z_down;
03460     if (spd <= v->max_speed) v->cur_speed = spd;
03461   }
03462 }
03463 
03464 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
03465 {
03466   if (IsTileType(tile, MP_RAILWAY) &&
03467       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
03468     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
03469     Trackdir trackdir = FindFirstTrackdir(tracks);
03470     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
03471       /* A PBS block with a non-PBS signal facing us? */
03472       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
03473     }
03474   }
03475   return false;
03476 }
03477 
03478 
03479 static void SetVehicleCrashed(Vehicle *v)
03480 {
03481   if (v->u.rail.crash_anim_pos != 0) return;
03482 
03483   if (IsFrontEngine(v)) {
03484     /* Remove the reserved path in front of the train if it is not stuck.
03485      * Also clear all reserved tracks the train is currently on. */
03486     if (!HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) FreeTrainTrackReservation(v);
03487     for (const Vehicle *u = v; u != NULL; u = u->Next()) {
03488       ClearPathReservation(u, u->tile, GetVehicleTrackdir(u));
03489       if (IsTileType(u->tile, MP_TUNNELBRIDGE)) {
03490         /* ClearPathReservation will not free the wormhole exit
03491          * if the train has just entered the wormhole. */
03492         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(u->tile), false);
03493       }
03494     }
03495   }
03496 
03497   /* we may need to update crossing we were approaching */
03498   TileIndex crossing = TrainApproachingCrossingTile(v);
03499 
03500   v->u.rail.crash_anim_pos++;
03501 
03502   InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03503   InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
03504 
03505   if (v->u.rail.track == TRACK_BIT_DEPOT) {
03506     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
03507   }
03508 
03509   InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
03510 
03511   for (; v != NULL; v = v->Next()) {
03512     v->vehstatus |= VS_CRASHED;
03513     MarkSingleVehicleDirty(v);
03514   }
03515 
03516   /* must be updated after the train has been marked crashed */
03517   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
03518 }
03519 
03520 static uint CountPassengersInTrain(const Vehicle *v)
03521 {
03522   uint num = 0;
03523 
03524   for (; v != NULL; v = v->Next()) {
03525     if (IsCargoInClass(v->cargo_type, CC_PASSENGERS)) num += v->cargo.Count();
03526   }
03527 
03528   return num;
03529 }
03530 
03537 static uint TrainCrashed(Vehicle *v)
03538 {
03539   /* do not crash train twice */
03540   if (v->vehstatus & VS_CRASHED) return 0;
03541 
03542   /* two drivers + passengers */
03543   uint num = 2 + CountPassengersInTrain(v);
03544 
03545   SetVehicleCrashed(v);
03546   AI::NewEvent(v->owner, new AIEventVehicleCrashed(v->index, v->tile, AIEventVehicleCrashed::CRASH_TRAIN));
03547 
03548   return num;
03549 }
03550 
03551 struct TrainCollideChecker {
03552   Vehicle *v;  
03553   uint num;    
03554 };
03555 
03556 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
03557 {
03558   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
03559 
03560   if (v->type != VEH_TRAIN) return NULL;
03561 
03562   /* get first vehicle now to make most usual checks faster */
03563   Vehicle *coll = v->First();
03564 
03565   /* can't collide with own wagons && can't crash in depot && the same height level */
03566   if (coll != tcc->v && v->u.rail.track != TRACK_BIT_DEPOT && abs(v->z_pos - tcc->v->z_pos) < 6) {
03567     int x_diff = v->x_pos - tcc->v->x_pos;
03568     int y_diff = v->y_pos - tcc->v->y_pos;
03569 
03570     /* needed to disable possible crash of competitor train in station by building diagonal track at its end */
03571     if (x_diff * x_diff + y_diff * y_diff > 25) return NULL;
03572 
03573     /* crash both trains */
03574     tcc->num += TrainCrashed(tcc->v);
03575     tcc->num += TrainCrashed(coll);
03576 
03577     /* Try to reserve all tiles directly under the crashed trains.
03578      * As there might be more than two trains involved, we have to do that for all vehicles */
03579     const Vehicle *u;
03580     FOR_ALL_VEHICLES(u) {
03581       if (u->type == VEH_TRAIN && HASBITS(u->vehstatus, VS_CRASHED) && (u->u.rail.track & TRACK_BIT_DEPOT) == TRACK_BIT_NONE) {
03582         TrackBits trackbits = u->u.rail.track;
03583         if ((trackbits & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03584           /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03585           trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(u->tile));
03586         }
03587         TryReserveRailTrack(u->tile, TrackBitsToTrack(trackbits));
03588       }
03589     }
03590   }
03591 
03592   return NULL;
03593 }
03594 
03601 static bool CheckTrainCollision(Vehicle *v)
03602 {
03603   /* can't collide in depot */
03604   if (v->u.rail.track == TRACK_BIT_DEPOT) return false;
03605 
03606   assert(v->u.rail.track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03607 
03608   TrainCollideChecker tcc;
03609   tcc.v = v;
03610   tcc.num = 0;
03611 
03612   /* find colliding vehicles */
03613   if (v->u.rail.track == TRACK_BIT_WORMHOLE) {
03614     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03615     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03616   } else {
03617     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03618   }
03619 
03620   /* any dead -> no crash */
03621   if (tcc.num == 0) return false;
03622 
03623   SetDParam(0, tcc.num);
03624   AddNewsItem(STR_8868_TRAIN_CRASH_DIE_IN_FIREBALL,
03625     NS_ACCIDENT_VEHICLE,
03626     v->index,
03627     0
03628   );
03629 
03630   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03631   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03632   return true;
03633 }
03634 
03635 static Vehicle *CheckVehicleAtSignal(Vehicle *v, void *data)
03636 {
03637   DiagDirection exitdir = *(DiagDirection *)data;
03638 
03639   /* front engine of a train, not inside wormhole or depot, not crashed */
03640   if (v->type == VEH_TRAIN && IsFrontEngine(v) && (v->u.rail.track & TRACK_BIT_MASK) != 0 && !(v->vehstatus & VS_CRASHED)) {
03641     if (v->cur_speed <= 5 && TrainExitDir(v->direction, v->u.rail.track) == exitdir) return v;
03642   }
03643 
03644   return NULL;
03645 }
03646 
03647 static void TrainController(Vehicle *v, Vehicle *nomove)
03648 {
03649   Vehicle *prev;
03650 
03651   /* For every vehicle after and including the given vehicle */
03652   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03653     DiagDirection enterdir = DIAGDIR_BEGIN;
03654     bool update_signals_crossing = false; // will we update signals or crossing state?
03655 
03656     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03657     if (v->u.rail.track != TRACK_BIT_WORMHOLE) {
03658       /* Not inside tunnel */
03659       if (gp.old_tile == gp.new_tile) {
03660         /* Staying in the old tile */
03661         if (v->u.rail.track == TRACK_BIT_DEPOT) {
03662           /* Inside depot */
03663           gp.x = v->x_pos;
03664           gp.y = v->y_pos;
03665         } else {
03666           /* Not inside depot */
03667 
03668           /* Reverse when we are at the end of the track already, do not move to the new position */
03669           if (IsFrontEngine(v) && !TrainCheckIfLineEnds(v)) return;
03670 
03671           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03672           if (HasBit(r, VETS_CANNOT_ENTER)) {
03673             goto invalid_rail;
03674           }
03675           if (HasBit(r, VETS_ENTERED_STATION)) {
03676             /* The new position is the end of the platform */
03677             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03678           }
03679         }
03680       } else {
03681         /* A new tile is about to be entered. */
03682 
03683         /* Determine what direction we're entering the new tile from */
03684         Direction dir = GetNewVehicleDirectionByTile(gp.new_tile, gp.old_tile);
03685         enterdir = DirToDiagDir(dir);
03686         assert(IsValidDiagDirection(enterdir));
03687 
03688         /* Get the status of the tracks in the new tile and mask
03689          * away the bits that aren't reachable. */
03690         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03691         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03692 
03693         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03694         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03695 
03696         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03697         if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg && prev == NULL) {
03698           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03699            * can be switched on halfway a turn */
03700           bits &= ~TrackCrossesTracks(FindFirstTrack(v->u.rail.track));
03701         }
03702 
03703         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03704 
03705         /* Check if the new tile contrains tracks that are compatible
03706          * with the current train, if not, bail out. */
03707         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03708 
03709         TrackBits chosen_track;
03710         if (prev == NULL) {
03711           /* Currently the locomotive is active. Determine which one of the
03712            * available tracks to choose */
03713           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03714           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03715 
03716           /* Check if it's a red signal and that force proceed is not clicked. */
03717           if (red_signals & chosen_track && v->u.rail.force_proceed == 0) {
03718             /* In front of a red signal */
03719             Trackdir i = FindFirstTrackdir(trackdirbits);
03720 
03721             /* Don't handle stuck trains here. */
03722             if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) return;
03723 
03724             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03725               v->cur_speed = 0;
03726               v->subspeed = 0;
03727               v->progress = 255 - 100;
03728               if (_settings_game.pf.wait_oneway_signal == 255 || ++v->load_unload_time_rem < _settings_game.pf.wait_oneway_signal * 20) return;
03729             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03730               v->cur_speed = 0;
03731               v->subspeed = 0;
03732               v->progress = 255 - 10;
03733               if (_settings_game.pf.wait_twoway_signal == 255 || ++v->load_unload_time_rem < _settings_game.pf.wait_twoway_signal * 73) {
03734                 DiagDirection exitdir = TrackdirToExitdir(i);
03735                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03736 
03737                 exitdir = ReverseDiagDir(exitdir);
03738 
03739                 /* check if a train is waiting on the other side */
03740                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckVehicleAtSignal)) return;
03741               }
03742             }
03743 
03744             /* If we would reverse but are currently in a PBS block and
03745              * reversing of stuck trains is disabled, don't reverse. */
03746             if (_settings_game.pf.wait_for_pbs_path == 255 && UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03747               v->load_unload_time_rem = 0;
03748               return;
03749             }
03750             goto reverse_train_direction;
03751           } else {
03752             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03753           }
03754         } else {
03755           static const TrackBits _matching_tracks[8] = {
03756               TRACK_BIT_LEFT  | TRACK_BIT_RIGHT, TRACK_BIT_X,
03757               TRACK_BIT_UPPER | TRACK_BIT_LOWER, TRACK_BIT_Y,
03758               TRACK_BIT_LEFT  | TRACK_BIT_RIGHT, TRACK_BIT_X,
03759               TRACK_BIT_UPPER | TRACK_BIT_LOWER, TRACK_BIT_Y
03760           };
03761 
03762           /* The wagon is active, simply follow the prev vehicle. */
03763           chosen_track = (TrackBits)(byte)(_matching_tracks[GetDirectionToVehicle(prev, gp.x, gp.y)] & bits);
03764         }
03765 
03766         /* Make sure chosen track is a valid track */
03767         assert(
03768             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03769             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03770             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03771 
03772         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03773         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03774         gp.x = (gp.x & ~0xF) | b[0];
03775         gp.y = (gp.y & ~0xF) | b[1];
03776         Direction chosen_dir = (Direction)b[2];
03777 
03778         /* Call the landscape function and tell it that the vehicle entered the tile */
03779         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03780         if (HasBit(r, VETS_CANNOT_ENTER)) {
03781           goto invalid_rail;
03782         }
03783 
03784         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03785           Track track = FindFirstTrack(chosen_track);
03786           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03787           if (IsFrontEngine(v) && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03788             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03789             MarkTileDirtyByTile(gp.new_tile);
03790           }
03791 
03792           /* Clear any track reservation when the last vehicle leaves the tile */
03793           if (v->Next() == NULL) ClearPathReservation(v, v->tile, GetVehicleTrackdir(v));
03794 
03795           v->tile = gp.new_tile;
03796 
03797           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03798             TrainPowerChanged(v->First());
03799           }
03800 
03801           v->u.rail.track = chosen_track;
03802           assert(v->u.rail.track);
03803         }
03804 
03805         /* We need to update signal status, but after the vehicle position hash
03806          * has been updated by AfterSetTrainPos() */
03807         update_signals_crossing = true;
03808 
03809         if (prev == NULL) AffectSpeedByDirChange(v, chosen_dir);
03810 
03811         v->direction = chosen_dir;
03812 
03813         if (IsFrontEngine(v)) {
03814           v->load_unload_time_rem = 0;
03815 
03816           /* If we are approching a crossing that is reserved, play the sound now. */
03817           TileIndex crossing = TrainApproachingCrossingTile(v);
03818           if (crossing != INVALID_TILE && GetCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03819 
03820           /* Always try to extend the reservation when entering a tile. */
03821           CheckNextTrainTile(v);
03822         }
03823       }
03824     } else {
03825       /* In a tunnel or on a bridge
03826        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03827        * - for bridges, only the middle part - without the bridge heads */
03828       if (!(v->vehstatus & VS_HIDDEN)) {
03829         v->cur_speed =
03830           min(v->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03831       }
03832 
03833       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03834         /* Perform look-ahead on tunnel exit. */
03835         if (IsFrontEngine(v)) {
03836           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03837           CheckNextTrainTile(v);
03838         }
03839       } else {
03840         v->x_pos = gp.x;
03841         v->y_pos = gp.y;
03842         VehicleMove(v, !(v->vehstatus & VS_HIDDEN));
03843         continue;
03844       }
03845     }
03846 
03847     /* update image of train, as well as delta XY */
03848     v->UpdateDeltaXY(v->direction);
03849 
03850     v->x_pos = gp.x;
03851     v->y_pos = gp.y;
03852 
03853     /* update the Z position of the vehicle */
03854     byte old_z = AfterSetTrainPos(v, (gp.new_tile != gp.old_tile));
03855 
03856     if (prev == NULL) {
03857       /* This is the first vehicle in the train */
03858       AffectSpeedByZChange(v, old_z);
03859     }
03860 
03861     if (update_signals_crossing) {
03862       if (IsFrontEngine(v)) {
03863         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03864           /* We are entering a block with PBS signals right now, but
03865            * not through a PBS signal. This means we don't have a
03866            * reservation right now. As a conventional signal will only
03867            * ever be green if no other train is in the block, getting
03868            * a path should always be possible. If the player built
03869            * such a strange network that it is not possible, the train
03870            * will be marked as stuck and the player has to deal with
03871            * the problem. */
03872           if ((!HasReservedTracks(gp.new_tile, v->u.rail.track) &&
03873               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->u.rail.track))) ||
03874               !TryPathReserve(v)) {
03875             MarkTrainAsStuck(v);
03876           }
03877         }
03878       }
03879 
03880       /* Signals can only change when the first
03881        * (above) or the last vehicle moves. */
03882       if (v->Next() == NULL) {
03883         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03884         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03885       }
03886     }
03887 
03888     /* Do not check on every tick to save some computing time. */
03889     if (IsFrontEngine(v) && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03890   }
03891   return;
03892 
03893 invalid_rail:
03894   /* We've reached end of line?? */
03895   if (prev != NULL) error("Disconnecting train");
03896 
03897 reverse_train_direction:
03898   v->load_unload_time_rem = 0;
03899   v->cur_speed = 0;
03900   v->subspeed = 0;
03901   ReverseTrainDirection(v);
03902 }
03903 
03909 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03910 {
03911   TrackBits *trackbits = (TrackBits *)data;
03912 
03913   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03914     if ((v->u.rail.track & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03915       /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03916       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03917     } else {
03918       *trackbits |= v->u.rail.track;
03919     }
03920   }
03921 
03922   return NULL;
03923 }
03924 
03932 static void DeleteLastWagon(Vehicle *v)
03933 {
03934   Vehicle *first = v->First();
03935 
03936   /* Go to the last wagon and delete the link pointing there
03937    * *u is then the one-before-last wagon, and *v the last
03938    * one which will physicially be removed */
03939   Vehicle *u = v;
03940   for (; v->Next() != NULL; v = v->Next()) u = v;
03941   u->SetNext(NULL);
03942 
03943   if (first != v) {
03944     /* Recalculate cached train properties */
03945     TrainConsistChanged(first, false);
03946     /* Update the depot window if the first vehicle is in depot -
03947      * if v == first, then it is updated in PreDestructor() */
03948     if (first->u.rail.track == TRACK_BIT_DEPOT) {
03949       InvalidateWindow(WC_VEHICLE_DEPOT, first->tile);
03950     }
03951   }
03952 
03953   /* 'v' shouldn't be accessed after it has been deleted */
03954   TrackBits trackbits = v->u.rail.track;
03955   TileIndex tile = v->tile;
03956   Owner owner = v->owner;
03957 
03958   delete v;
03959   v = NULL; // make sure nobody will try to read 'v' anymore
03960 
03961   if ((trackbits & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03962     /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03963     trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03964   }
03965 
03966   Track track = TrackBitsToTrack(trackbits);
03967   if (HasReservedTracks(tile, trackbits)) {
03968     UnreserveRailTrack(tile, track);
03969 
03970     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03971     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03972     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03973 
03974     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03975     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03976     for (Track t = TRACK_BEGIN; t < TRACK_END; t++) {
03977       if (HasBit(remaining_trackbits, t)) {
03978         TryReserveRailTrack(tile, t);
03979       }
03980     }
03981   }
03982 
03983   /* check if the wagon was on a road/rail-crossing */
03984   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03985 
03986   /* Update signals */
03987   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03988     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03989   } else {
03990     SetSignalsOnBothDir(tile, track, owner);
03991   }
03992 }
03993 
03994 static void ChangeTrainDirRandomly(Vehicle *v)
03995 {
03996   static const DirDiff delta[] = {
03997     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03998   };
03999 
04000   do {
04001     /* We don't need to twist around vehicles if they're not visible */
04002     if (!(v->vehstatus & VS_HIDDEN)) {
04003       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
04004       v->UpdateDeltaXY(v->direction);
04005       v->cur_image = v->GetImage(v->direction);
04006       /* Refrain from updating the z position of the vehicle when on
04007        * a bridge, because AfterSetTrainPos will put the vehicle under
04008        * the bridge in that case */
04009       if (v->u.rail.track != TRACK_BIT_WORMHOLE) AfterSetTrainPos(v, false);
04010     }
04011   } while ((v = v->Next()) != NULL);
04012 }
04013 
04014 static void HandleCrashedTrain(Vehicle *v)
04015 {
04016   int state = ++v->u.rail.crash_anim_pos;
04017 
04018   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
04019     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
04020   }
04021 
04022   uint32 r;
04023   if (state <= 200 && Chance16R(1, 7, r)) {
04024     int index = (r * 10 >> 16);
04025 
04026     Vehicle *u = v;
04027     do {
04028       if (--index < 0) {
04029         r = Random();
04030 
04031         CreateEffectVehicleRel(u,
04032           GB(r,  8, 3) + 2,
04033           GB(r, 16, 3) + 2,
04034           GB(r,  0, 3) + 5,
04035           EV_EXPLOSION_SMALL);
04036         break;
04037       }
04038     } while ((u = u->Next()) != NULL);
04039   }
04040 
04041   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
04042 
04043   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
04044     DeleteLastWagon(v);
04045     InvalidateWindow(WC_REPLACE_VEHICLE, (v->group_id << 16) | VEH_TRAIN);
04046   }
04047 }
04048 
04049 static void HandleBrokenTrain(Vehicle *v)
04050 {
04051   if (v->breakdown_ctr != 1) {
04052     v->breakdown_ctr = 1;
04053     v->cur_speed = 0;
04054 
04055     if (v->breakdowns_since_last_service != 255)
04056       v->breakdowns_since_last_service++;
04057 
04058     InvalidateWindow(WC_VEHICLE_VIEW, v->index);
04059     InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
04060     v->MarkDirty();
04061 
04062     if (!PlayVehicleSound(v, VSE_BREAKDOWN)) {
04063       SndPlayVehicleFx((_settings_game.game_creation.landscape != LT_TOYLAND) ?
04064         SND_10_TRAIN_BREAKDOWN : SND_3A_COMEDY_BREAKDOWN_2, v);
04065     }
04066 
04067     if (!(v->vehstatus & VS_HIDDEN)) {
04068       Vehicle *u = CreateEffectVehicleRel(v, 4, 4, 5, EV_BREAKDOWN_SMOKE);
04069       if (u != NULL) u->u.effect.animation_state = v->breakdown_delay * 2;
04070     }
04071   }
04072 
04073   if (!(v->tick_counter & 3)) {
04074     if (!--v->breakdown_delay) {
04075       v->breakdown_ctr = 0;
04076       InvalidateWindow(WC_VEHICLE_VIEW, v->index);
04077       v->MarkDirty();
04078     }
04079   }
04080 }
04081 
04083 static const uint16 _breakdown_speeds[16] = {
04084   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
04085 };
04086 
04087 
04095 static bool TrainApproachingLineEnd(Vehicle *v, bool signal)
04096 {
04097   /* Calc position within the current tile */
04098   uint x = v->x_pos & 0xF;
04099   uint y = v->y_pos & 0xF;
04100 
04101   /* for diagonal directions, 'x' will be 0..15 -
04102    * for other directions, it will be 1, 3, 5, ..., 15 */
04103   switch (v->direction) {
04104     case DIR_N : x = ~x + ~y + 25; break;
04105     case DIR_NW: x = y;            // FALLTHROUGH
04106     case DIR_NE: x = ~x + 16;      break;
04107     case DIR_E : x = ~x + y + 9;   break;
04108     case DIR_SE: x = y;            break;
04109     case DIR_S : x = x + y - 7;    break;
04110     case DIR_W : x = ~y + x + 9;   break;
04111     default: break;
04112   }
04113 
04114   /* do not reverse when approaching red signal */
04115   if (!signal && x + (v->u.rail.cached_veh_length + 1) / 2 >= TILE_SIZE) {
04116     /* we are too near the tile end, reverse now */
04117     v->cur_speed = 0;
04118     ReverseTrainDirection(v);
04119     return false;
04120   }
04121 
04122   /* slow down */
04123   v->vehstatus |= VS_TRAIN_SLOWING;
04124   uint16 break_speed = _breakdown_speeds[x & 0xF];
04125   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
04126 
04127   return true;
04128 }
04129 
04130 
04136 static bool TrainCanLeaveTile(const Vehicle *v)
04137 {
04138   /* Exit if inside a tunnel/bridge or a depot */
04139   if (v->u.rail.track == TRACK_BIT_WORMHOLE || v->u.rail.track == TRACK_BIT_DEPOT) return false;
04140 
04141   TileIndex tile = v->tile;
04142 
04143   /* entering a tunnel/bridge? */
04144   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
04145     DiagDirection dir = GetTunnelBridgeDirection(tile);
04146     if (DiagDirToDir(dir) == v->direction) return false;
04147   }
04148 
04149   /* entering a depot? */
04150   if (IsRailDepotTile(tile)) {
04151     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
04152     if (DiagDirToDir(dir) == v->direction) return false;
04153   }
04154 
04155   return true;
04156 }
04157 
04158 
04166 static TileIndex TrainApproachingCrossingTile(const Vehicle *v)
04167 {
04168   assert(IsFrontEngine(v));
04169   assert(!(v->vehstatus & VS_CRASHED));
04170 
04171   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
04172 
04173   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
04174   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
04175 
04176   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
04177   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
04178       !CheckCompatibleRail(v, tile)) {
04179     return INVALID_TILE;
04180   }
04181 
04182   return tile;
04183 }
04184 
04185 
04192 static bool TrainCheckIfLineEnds(Vehicle *v)
04193 {
04194   /* First, handle broken down train */
04195 
04196   int t = v->breakdown_ctr;
04197   if (t > 1) {
04198     v->vehstatus |= VS_TRAIN_SLOWING;
04199 
04200     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
04201     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
04202   } else {
04203     v->vehstatus &= ~VS_TRAIN_SLOWING;
04204   }
04205 
04206   if (!TrainCanLeaveTile(v)) return true;
04207 
04208   /* Determine the non-diagonal direction in which we will exit this tile */
04209   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
04210   /* Calculate next tile */
04211   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
04212 
04213   /* Determine the track status on the next tile */
04214   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
04215   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
04216 
04217   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
04218   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
04219 
04220   /* We are sure the train is not entering a depot, it is detected above */
04221 
04222   /* mask unreachable track bits if we are forbidden to do 90deg turns */
04223   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
04224   if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
04225     bits &= ~TrackCrossesTracks(FindFirstTrack(v->u.rail.track));
04226   }
04227 
04228   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
04229   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
04230     return TrainApproachingLineEnd(v, false);
04231   }
04232 
04233   /* approaching red signal */
04234   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true);
04235 
04236   /* approaching a rail/road crossing? then make it red */
04237   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
04238 
04239   return true;
04240 }
04241 
04242 
04243 static void TrainLocoHandler(Vehicle *v, bool mode)
04244 {
04245   /* train has crashed? */
04246   if (v->vehstatus & VS_CRASHED) {
04247     if (!mode) HandleCrashedTrain(v);
04248     return;
04249   }
04250 
04251   if (v->u.rail.force_proceed != 0) {
04252     v->u.rail.force_proceed--;
04253     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
04254     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04255   }
04256 
04257   /* train is broken down? */
04258   if (v->breakdown_ctr != 0) {
04259     if (v->breakdown_ctr <= 2) {
04260       HandleBrokenTrain(v);
04261       return;
04262     }
04263     if (!v->current_order.IsType(OT_LOADING)) v->breakdown_ctr--;
04264   }
04265 
04266   if (HasBit(v->u.rail.flags, VRF_REVERSING) && v->cur_speed == 0) {
04267     ReverseTrainDirection(v);
04268   }
04269 
04270   /* exit if train is stopped */
04271   if (v->vehstatus & VS_STOPPED && v->cur_speed == 0) return;
04272 
04273   bool valid_order = v->current_order.IsValid() && v->current_order.GetType() != OT_CONDITIONAL;
04274   if (ProcessOrders(v) && CheckReverseTrain(v)) {
04275     v->load_unload_time_rem = 0;
04276     v->cur_speed = 0;
04277     v->subspeed = 0;
04278     ReverseTrainDirection(v);
04279     return;
04280   }
04281 
04282   v->HandleLoading(mode);
04283 
04284   if (v->current_order.IsType(OT_LOADING)) return;
04285 
04286   if (CheckTrainStayInDepot(v)) return;
04287 
04288   if (!mode) HandleLocomotiveSmokeCloud(v);
04289 
04290   /* We had no order but have an order now, do look ahead. */
04291   if (!valid_order && v->current_order.IsValid()) {
04292     CheckNextTrainTile(v);
04293   }
04294 
04295   /* Handle stuck trains. */
04296   if (!mode && HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
04297     ++v->load_unload_time_rem;
04298 
04299     /* Should we try reversing this tick if still stuck? */
04300     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;
04301 
04302     if (!turn_around && v->load_unload_time_rem % _settings_game.pf.path_backoff_interval != 0 && v->u.rail.force_proceed == 0) return;
04303     if (!TryPathReserve(v)) {
04304       /* Still stuck. */
04305       if (turn_around) ReverseTrainDirection(v);
04306 
04307       if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK) && v->load_unload_time_rem > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
04308         /* Show message to player. */
04309         if (_settings_client.gui.lost_train_warn && v->owner == _local_company) {
04310           SetDParam(0, v->index);
04311           AddNewsItem(
04312             STR_TRAIN_IS_STUCK,
04313             NS_ADVICE,
04314             v->index,
04315             0);
04316         }
04317         v->load_unload_time_rem = 0;
04318       }
04319       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
04320       if (v->u.rail.force_proceed == 0) return;
04321       ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
04322       v->load_unload_time_rem = 0;
04323       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04324     }
04325   }
04326 
04327   if (v->current_order.IsType(OT_LEAVESTATION)) {
04328     v->current_order.Free();
04329     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04330     return;
04331   }
04332 
04333   int j = UpdateTrainSpeed(v);
04334 
04335   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
04336   if (v->cur_speed == 0 && v->u.rail.last_speed == 0 && v->vehstatus & VS_STOPPED) {
04337     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04338   }
04339 
04340   int adv_spd = (v->direction & 1) ? 192 : 256;
04341   if (j < adv_spd) {
04342     /* if the vehicle has speed 0, update the last_speed field. */
04343     if (v->cur_speed == 0) SetLastSpeed(v, v->cur_speed);
04344   } else {
04345     TrainCheckIfLineEnds(v);
04346     /* Loop until the train has finished moving. */
04347     for (;;) {
04348       j -= adv_spd;
04349       TrainController(v, NULL);
04350       /* Don't continue to move if the train crashed. */
04351       if (CheckTrainCollision(v)) break;
04352       /* 192 spd used for going straight, 256 for going diagonally. */
04353       adv_spd = (v->direction & 1) ? 192 : 256;
04354 
04355       /* No more moving this tick */
04356       if (j < adv_spd || v->cur_speed == 0) break;
04357 
04358       OrderType order_type = v->current_order.GetType();
04359       /* Do not skip waypoints (incl. 'via' stations) when passing through at full speed. */
04360       if ((order_type == OT_GOTO_WAYPOINT &&
04361             v->dest_tile == v->tile) ||
04362           (order_type == OT_GOTO_STATION &&
04363             (v->current_order.GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
04364             IsTileType(v->tile, MP_STATION) &&
04365             v->current_order.GetDestination() == GetStationIndex(v->tile))) {
04366         ProcessOrders(v);
04367       }
04368     }
04369     SetLastSpeed(v, v->cur_speed);
04370   }
04371 
04372   for (Vehicle *u = v; u != NULL; u = u->Next()) {
04373     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
04374 
04375     u->UpdateViewport(false, false);
04376   }
04377 
04378   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
04379 }
04380 
04381 
04382 
04383 Money Train::GetRunningCost() const
04384 {
04385   Money cost = 0;
04386   const Vehicle *v = this;
04387 
04388   do {
04389     const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
04390 
04391     byte cost_factor = GetVehicleProperty(v, 0x0D, rvi->running_cost);
04392     if (cost_factor == 0) continue;
04393 
04394     /* Halve running cost for multiheaded parts */
04395     if (IsMultiheaded(v)) cost_factor /= 2;
04396 
04397     cost += cost_factor * GetPriceByIndex(rvi->running_cost_class);
04398   } while ((v = GetNextVehicle(v)) != NULL);
04399 
04400   return cost;
04401 }
04402 
04403 
04404 void Train::Tick()
04405 {
04406   if (_age_cargo_skip_counter == 0) this->cargo.AgeCargo();
04407 
04408   this->tick_counter++;
04409 
04410   if (IsFrontEngine(this)) {
04411     if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;
04412     this->current_order_time++;
04413 
04414     TrainLocoHandler(this, false);
04415 
04416     /* make sure vehicle wasn't deleted. */
04417     if (this->type == VEH_TRAIN && IsFrontEngine(this))
04418       TrainLocoHandler(this, true);
04419   } else if (IsFreeWagon(this) && HASBITS(this->vehstatus, VS_CRASHED)) {
04420     /* Delete flooded standalone wagon chain */
04421     if (++this->u.rail.crash_anim_pos >= 4400) delete this;
04422   }
04423 }
04424 
04425 static void CheckIfTrainNeedsService(Vehicle *v)
04426 {
04427   static const uint MAX_ACCEPTABLE_DEPOT_DIST = 16;
04428 
04429   if (_settings_game.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
04430   if (v->IsInDepot()) {
04431     VehicleServiceInDepot(v);
04432     return;
04433   }
04434 
04435   TrainFindDepotData tfdd = FindClosestTrainDepot(v, MAX_ACCEPTABLE_DEPOT_DIST);
04436   /* Only go to the depot if it is not too far out of our way. */
04437   if (tfdd.best_length == UINT_MAX || tfdd.best_length > MAX_ACCEPTABLE_DEPOT_DIST) {
04438     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
04439       /* If we were already heading for a depot but it has
04440        * suddenly moved farther away, we continue our normal
04441        * schedule? */
04442       v->current_order.MakeDummy();
04443       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04444     }
04445     return;
04446   }
04447 
04448   const Depot *depot = GetDepotByTile(tfdd.tile);
04449 
04450   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
04451       v->current_order.GetDestination() != depot->index &&
04452       !Chance16(3, 16)) {
04453     return;
04454   }
04455 
04456   v->current_order.MakeGoToDepot(depot->index, ODTFB_SERVICE);
04457   v->dest_tile = tfdd.tile;
04458   InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04459 }
04460 
04461 void Train::OnNewDay()
04462 {
04463   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
04464 
04465   if (IsFrontEngine(this)) {
04466     CheckVehicleBreakdown(this);
04467     AgeVehicle(this);
04468 
04469     CheckIfTrainNeedsService(this);
04470 
04471     CheckOrders(this);
04472 
04473     /* update destination */
04474     if (this->current_order.IsType(OT_GOTO_STATION)) {
04475       TileIndex tile = GetStation(this->current_order.GetDestination())->train_tile;
04476       if (tile != INVALID_TILE) this->dest_tile = tile;
04477     }
04478 
04479     if (this->running_ticks != 0) {
04480       /* running costs */
04481       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
04482 
04483       this->profit_this_year -= cost.GetCost();
04484       this->running_ticks = 0;
04485 
04486       SubtractMoneyFromCompanyFract(this->owner, cost);
04487 
04488       InvalidateWindow(WC_VEHICLE_DETAILS, this->index);
04489       InvalidateWindowClasses(WC_TRAINS_LIST);
04490     }
04491   } else if (IsTrainEngine(this)) {
04492     /* Also age engines that aren't front engines */
04493     AgeVehicle(this);
04494   }
04495 }
04496 
04497 void InitializeTrains()
04498 {
04499   _age_cargo_skip_counter = 1;
04500 }

Generated on Thu Sep 24 19:35:07 2009 for OpenTTD by  doxygen 1.5.6