train_cmd.cpp

Go to the documentation of this file.
00001 /* $Id: train_cmd.cpp 15718 2009-03-15 00:32:18Z 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     u->cache_valid = 0;
00245   }
00246 
00247   for (Vehicle *u = v; u != NULL; u = u->Next()) {
00248     /* Update user defined data (must be done before other properties) */
00249     u->u.rail.user_def_data = GetVehicleProperty(u, 0x25, u->u.rail.user_def_data);
00250     u->cache_valid = 0;
00251   }
00252 
00253   for (Vehicle *u = v; u != NULL; u = u->Next()) {
00254     const Engine *e_u = GetEngine(u->engine_type);
00255     const RailVehicleInfo *rvi_u = &e_u->u.rail;
00256 
00257     if (!HasBit(EngInfo(u->engine_type)->misc_flags, EF_RAIL_TILTS)) train_can_tilt = false;
00258 
00259     /* Cache wagon override sprite group. NULL is returned if there is none */
00260     u->u.rail.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->u.rail.first_engine);
00261 
00262     /* Reset colour map */
00263     u->colourmap = PAL_NONE;
00264 
00265     if (rvi_u->visual_effect != 0) {
00266       u->u.rail.cached_vis_effect = rvi_u->visual_effect;
00267     } else {
00268       if (IsTrainWagon(u) || IsArticulatedPart(u)) {
00269         /* Wagons and articulated parts have no effect by default */
00270         u->u.rail.cached_vis_effect = 0x40;
00271       } else if (rvi_u->engclass == 0) {
00272         /* Steam is offset by -4 units */
00273         u->u.rail.cached_vis_effect = 4;
00274       } else {
00275         /* Diesel fumes and sparks come from the centre */
00276         u->u.rail.cached_vis_effect = 8;
00277       }
00278     }
00279 
00280     /* Check powered wagon / visual effect callback */
00281     if (HasBit(EngInfo(u->engine_type)->callbackmask, CBM_TRAIN_WAGON_POWER)) {
00282       uint16 callback = GetVehicleCallback(CBID_TRAIN_WAGON_POWER, 0, 0, u->engine_type, u);
00283 
00284       if (callback != CALLBACK_FAILED) u->u.rail.cached_vis_effect = GB(callback, 0, 8);
00285     }
00286 
00287     if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
00288       UsesWagonOverride(u) && !HasBit(u->u.rail.cached_vis_effect, 7)) {
00289       /* wagon is powered */
00290       SetBit(u->u.rail.flags, VRF_POWEREDWAGON); // cache 'powered' status
00291     } else {
00292       ClrBit(u->u.rail.flags, VRF_POWEREDWAGON);
00293     }
00294 
00295     if (!IsArticulatedPart(u)) {
00296       /* Do not count powered wagons for the compatible railtypes, as wagons always
00297          have railtype normal */
00298       if (rvi_u->power > 0) {
00299         v->u.rail.compatible_railtypes |= GetRailTypeInfo(u->u.rail.railtype)->powered_railtypes;
00300       }
00301 
00302       /* Some electric engines can be allowed to run on normal rail. It happens to all
00303        * existing electric engines when elrails are disabled and then re-enabled */
00304       if (HasBit(u->u.rail.flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL)) {
00305         u->u.rail.railtype = RAILTYPE_RAIL;
00306         u->u.rail.compatible_railtypes |= RAILTYPES_RAIL;
00307       }
00308 
00309       /* max speed is the minimum of the speed limits of all vehicles in the consist */
00310       if ((rvi_u->railveh_type != RAILVEH_WAGON || _settings_game.vehicle.wagon_speed_limits) && !UsesWagonOverride(u)) {
00311         uint16 speed = GetVehicleProperty(u, 0x09, rvi_u->max_speed);
00312         if (speed != 0) max_speed = min(speed, max_speed);
00313       }
00314     }
00315 
00316     if (e_u->CanCarryCargo() && u->cargo_type == e_u->GetDefaultCargoType() && u->cargo_subtype == 0) {
00317       /* Set cargo capacity if we've not been refitted */
00318       u->cargo_cap = GetVehicleProperty(u, 0x14, rvi_u->capacity);
00319     }
00320 
00321     /* check the vehicle length (callback) */
00322     uint16 veh_len = CALLBACK_FAILED;
00323     if (HasBit(EngInfo(u->engine_type)->callbackmask, CBM_VEHICLE_LENGTH)) {
00324       veh_len = GetVehicleCallback(CBID_VEHICLE_LENGTH, 0, 0, u->engine_type, u);
00325     }
00326     if (veh_len == CALLBACK_FAILED) veh_len = rvi_u->shorten_factor;
00327     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
00328 
00329     /* verify length hasn't changed */
00330     if (same_length && veh_len != u->u.rail.cached_veh_length) RailVehicleLengthChanged(u);
00331 
00332     /* update vehicle length? */
00333     if (!same_length) u->u.rail.cached_veh_length = veh_len;
00334 
00335     v->u.rail.cached_total_length += u->u.rail.cached_veh_length;
00336     u->cache_valid = 0;
00337   }
00338 
00339   /* store consist weight/max speed in cache */
00340   v->u.rail.cached_max_speed = max_speed;
00341   v->u.rail.cached_tilt = train_can_tilt;
00342 
00343   /* 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) */
00344   TrainCargoChanged(v);
00345 
00346   if (IsFrontEngine(v)) {
00347     UpdateTrainAcceleration(v);
00348     InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
00349   }
00350 }
00351 
00352 enum AccelType {
00353   AM_ACCEL,
00354   AM_BRAKE
00355 };
00356 
00358 static int GetTrainAcceleration(Vehicle *v, bool mode)
00359 {
00360   static const int absolute_max_speed = UINT16_MAX;
00361   int max_speed = absolute_max_speed;
00362   int speed = v->cur_speed * 10 / 16; // km-ish/h -> mp/h
00363   int curvecount[2] = {0, 0};
00364 
00365   /* first find the curve speed limit */
00366   int numcurve = 0;
00367   int sum = 0;
00368   int pos = 0;
00369   int lastpos = -1;
00370   for (const Vehicle *u = v; u->Next() != NULL; u = u->Next(), pos++) {
00371     Direction this_dir = u->direction;
00372     Direction next_dir = u->Next()->direction;
00373 
00374     DirDiff dirdiff = DirDifference(this_dir, next_dir);
00375     if (dirdiff == DIRDIFF_SAME) continue;
00376 
00377     if (dirdiff == DIRDIFF_45LEFT) curvecount[0]++;
00378     if (dirdiff == DIRDIFF_45RIGHT) curvecount[1]++;
00379     if (dirdiff == DIRDIFF_45LEFT || dirdiff == DIRDIFF_45RIGHT) {
00380       if (lastpos != -1) {
00381         numcurve++;
00382         sum += pos - lastpos;
00383         if (pos - lastpos == 1) {
00384           max_speed = 88;
00385         }
00386       }
00387       lastpos = pos;
00388     }
00389 
00390     /* if we have a 90 degree turn, fix the speed limit to 60 */
00391     if (dirdiff == DIRDIFF_90LEFT || dirdiff == DIRDIFF_90RIGHT) {
00392       max_speed = 61;
00393     }
00394   }
00395 
00396   if ((curvecount[0] != 0 || curvecount[1] != 0) && max_speed > 88) {
00397     int total = curvecount[0] + curvecount[1];
00398 
00399     if (curvecount[0] == 1 && curvecount[1] == 1) {
00400       max_speed = absolute_max_speed;
00401     } else if (total > 1) {
00402       if (numcurve > 0) sum /= numcurve;
00403       max_speed = 232 - (13 - Clamp(sum, 1, 12)) * (13 - Clamp(sum, 1, 12));
00404     }
00405   }
00406 
00407   if (max_speed != absolute_max_speed) {
00408     /* Apply the engine's rail type curve speed advantage, if it slowed by curves */
00409     const RailtypeInfo *rti = GetRailTypeInfo(v->u.rail.railtype);
00410     max_speed += (max_speed / 2) * rti->curve_speed;
00411 
00412     if (v->u.rail.cached_tilt) {
00413       /* Apply max_speed bonus of 20% for a tilting train */
00414       max_speed += max_speed / 5;
00415     }
00416   }
00417 
00418   if (IsTileType(v->tile, MP_STATION) && IsFrontEngine(v)) {
00419     if (v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) {
00420       int station_length = GetStationByTile(v->tile)->GetPlatformLength(v->tile, DirToDiagDir(v->direction));
00421 
00422       int st_max_speed = 120;
00423 
00424       int delta_v = v->cur_speed / (station_length + 1);
00425       if (v->max_speed > (v->cur_speed - delta_v)) {
00426         st_max_speed = v->cur_speed - (delta_v / 10);
00427       }
00428 
00429       st_max_speed = max(st_max_speed, 25 * station_length);
00430       max_speed = min(max_speed, st_max_speed);
00431     }
00432   }
00433 
00434   int mass = v->u.rail.cached_weight;
00435   int power = v->u.rail.cached_power * 746;
00436   max_speed = min(max_speed, v->u.rail.cached_max_speed);
00437 
00438   int num = 0; // number of vehicles, change this into the number of axles later
00439   int incl = 0;
00440   int drag_coeff = 20; //[1e-4]
00441   for (const Vehicle *u = v; u != NULL; u = u->Next()) {
00442     num++;
00443     drag_coeff += 3;
00444 
00445     if (u->u.rail.track == TRACK_BIT_DEPOT) max_speed = min(max_speed, 61);
00446 
00447     if (HasBit(u->u.rail.flags, VRF_GOINGUP)) {
00448       incl += u->u.rail.cached_veh_weight * 60; // 3% slope, quite a bit actually
00449     } else if (HasBit(u->u.rail.flags, VRF_GOINGDOWN)) {
00450       incl -= u->u.rail.cached_veh_weight * 60;
00451     }
00452   }
00453 
00454   v->max_speed = max_speed;
00455 
00456   const int area = 120;
00457   const int friction = 35; //[1e-3]
00458   int resistance;
00459   if (v->u.rail.railtype != RAILTYPE_MAGLEV) {
00460     resistance = 13 * mass / 10;
00461     resistance += 60 * num;
00462     resistance += friction * mass * speed / 1000;
00463     resistance += (area * drag_coeff * speed * speed) / 10000;
00464   } else {
00465     resistance = (area * (drag_coeff / 2) * speed * speed) / 10000;
00466   }
00467   resistance += incl;
00468   resistance *= 4; //[N]
00469 
00470   const int max_te = v->u.rail.cached_max_te; // [N]
00471   int force;
00472   if (speed > 0) {
00473     switch (v->u.rail.railtype) {
00474       case RAILTYPE_RAIL:
00475       case RAILTYPE_ELECTRIC:
00476       case RAILTYPE_MONO:
00477         force = power / speed; //[N]
00478         force *= 22;
00479         force /= 10;
00480         if (mode == AM_ACCEL && force > max_te) force = max_te;
00481         break;
00482 
00483       default: NOT_REACHED();
00484       case RAILTYPE_MAGLEV:
00485         force = power / 25;
00486         break;
00487     }
00488   } else {
00489     /* "kickoff" acceleration */
00490     force = (mode == AM_ACCEL && v->u.rail.railtype != RAILTYPE_MAGLEV) ? min(max_te, power) : power;
00491     force = max(force, (mass * 8) + resistance);
00492   }
00493 
00494   if (mode == AM_ACCEL) {
00495     return (force - resistance) / (mass * 2);
00496   } else {
00497     return min(-force - resistance, -10000) / mass;
00498   }
00499 }
00500 
00501 void UpdateTrainAcceleration(Vehicle *v)
00502 {
00503   assert(IsFrontEngine(v));
00504 
00505   v->max_speed = v->u.rail.cached_max_speed;
00506 
00507   uint power = v->u.rail.cached_power;
00508   uint weight = v->u.rail.cached_weight;
00509   assert(weight != 0);
00510   v->acceleration = Clamp(power / weight * 4, 1, 255);
00511 }
00512 
00513 SpriteID Train::GetImage(Direction direction) const
00514 {
00515   uint8 spritenum = this->spritenum;
00516   SpriteID sprite;
00517 
00518   if (HasBit(this->u.rail.flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
00519 
00520   if (is_custom_sprite(spritenum)) {
00521     sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)));
00522     if (sprite != 0) return sprite;
00523 
00524     spritenum = GetEngine(this->engine_type)->image_index;
00525   }
00526 
00527   sprite = _engine_sprite_base[spritenum] + ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]);
00528 
00529   if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
00530 
00531   return sprite;
00532 }
00533 
00534 static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y)
00535 {
00536   Direction dir = rear_head ? DIR_E : DIR_W;
00537   uint8 spritenum = RailVehInfo(engine)->image_index;
00538 
00539   if (is_custom_sprite(spritenum)) {
00540     SpriteID sprite = GetCustomVehicleIcon(engine, dir);
00541     if (sprite != 0) {
00542       y += _traininfo_vehicle_pitch; // TODO Make this per-GRF
00543       return sprite;
00544     }
00545 
00546     spritenum = GetEngine(engine)->image_index;
00547   }
00548 
00549   if (rear_head) spritenum++;
00550 
00551   return ((6 + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
00552 }
00553 
00554 void DrawTrainEngine(int x, int y, EngineID engine, SpriteID pal)
00555 {
00556   if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
00557     int yf = y;
00558     int yr = y;
00559 
00560     SpriteID spritef = GetRailIcon(engine, false, yf);
00561     SpriteID spriter = GetRailIcon(engine, true, yr);
00562     DrawSprite(spritef, pal, x - 14, yf);
00563     DrawSprite(spriter, pal, x + 15, yr);
00564   } else {
00565     SpriteID sprite = GetRailIcon(engine, false, y);
00566     DrawSprite(sprite, pal, x, y);
00567   }
00568 }
00569 
00570 static CommandCost CmdBuildRailWagon(EngineID engine, TileIndex tile, DoCommandFlag flags)
00571 {
00572   const Engine *e = GetEngine(engine);
00573   const RailVehicleInfo *rvi = &e->u.rail;
00574   CommandCost value(EXPENSES_NEW_VEHICLES, e->GetCost());
00575 
00576   /* Engines without valid cargo should not be available */
00577   if (e->GetDefaultCargoType() == CT_INVALID) return CMD_ERROR;
00578 
00579   if (flags & DC_QUERY_COST) return value;
00580 
00581   /* Check that the wagon can drive on the track in question */
00582   if (!IsCompatibleRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00583 
00584   uint num_vehicles = 1 + CountArticulatedParts(engine, false);
00585 
00586   /* Allow for the wagon and the articulated parts, plus one to "terminate" the list. */
00587   Vehicle **vl = AllocaM(Vehicle*, num_vehicles + 1);
00588   memset(vl, 0, sizeof(*vl) * (num_vehicles + 1));
00589 
00590   if (!Vehicle::AllocateList(vl, num_vehicles)) {
00591     return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
00592   }
00593 
00594   if (flags & DC_EXEC) {
00595     Vehicle *v = vl[0];
00596     v->spritenum = rvi->image_index;
00597 
00598     Vehicle *u = NULL;
00599 
00600     Vehicle *w;
00601     FOR_ALL_VEHICLES(w) {
00602       if (w->type == VEH_TRAIN && w->tile == tile &&
00603           IsFreeWagon(w) && w->engine_type == engine &&
00604           !HASBITS(w->vehstatus, VS_CRASHED)) {          
00605         u = GetLastVehicleInChain(w);
00606         break;
00607       }
00608     }
00609 
00610     v = new (v) Train();
00611     v->engine_type = engine;
00612 
00613     DiagDirection dir = GetRailDepotDirection(tile);
00614 
00615     v->direction = DiagDirToDir(dir);
00616     v->tile = tile;
00617 
00618     int x = TileX(tile) * TILE_SIZE | _vehicle_initial_x_fract[dir];
00619     int y = TileY(tile) * TILE_SIZE | _vehicle_initial_y_fract[dir];
00620 
00621     v->x_pos = x;
00622     v->y_pos = y;
00623     v->z_pos = GetSlopeZ(x, y);
00624     v->owner = _current_company;
00625     v->u.rail.track = TRACK_BIT_DEPOT;
00626     v->vehstatus = VS_HIDDEN | VS_DEFPAL;
00627 
00628 //    v->subtype = 0;
00629     SetTrainWagon(v);
00630 
00631     if (u != NULL) {
00632       u->SetNext(v);
00633     } else {
00634       SetFreeWagon(v);
00635       InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00636     }
00637 
00638     v->cargo_type = e->GetDefaultCargoType();
00639 //    v->cargo_subtype = 0;
00640     v->cargo_cap = rvi->capacity;
00641     v->value = value.GetCost();
00642 //    v->day_counter = 0;
00643 
00644     v->u.rail.railtype = rvi->railtype;
00645 
00646     v->build_year = _cur_year;
00647     v->cur_image = 0xAC2;
00648     v->random_bits = VehicleRandomBits();
00649 
00650     v->group_id = DEFAULT_GROUP;
00651 
00652     AddArticulatedParts(vl, VEH_TRAIN);
00653 
00654     _new_vehicle_id = v->index;
00655 
00656     VehicleMove(v, false);
00657     TrainConsistChanged(v->First(), false);
00658     UpdateTrainGroupID(v->First());
00659 
00660     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
00661     if (IsLocalCompany()) {
00662       InvalidateAutoreplaceWindow(v->engine_type, v->group_id); // updates the replace Train window
00663     }
00664     GetCompany(_current_company)->num_engines[engine]++;
00665 
00666     CheckConsistencyOfArticulatedVehicle(v);
00667   }
00668 
00669   return value;
00670 }
00671 
00673 static void NormalizeTrainVehInDepot(const Vehicle *u)
00674 {
00675   const Vehicle *v;
00676 
00677   FOR_ALL_VEHICLES(v) {
00678     if (v->type == VEH_TRAIN && IsFreeWagon(v) &&
00679         v->tile == u->tile &&
00680         v->u.rail.track == TRACK_BIT_DEPOT) {
00681       if (CmdFailed(DoCommand(0, v->index | (u->index << 16), 1, DC_EXEC,
00682           CMD_MOVE_RAIL_VEHICLE)))
00683         break;
00684     }
00685   }
00686 }
00687 
00688 static void AddRearEngineToMultiheadedTrain(Vehicle *v, Vehicle *u, bool building)
00689 {
00690   u = new (u) Train();
00691   u->direction = v->direction;
00692   u->owner = v->owner;
00693   u->tile = v->tile;
00694   u->x_pos = v->x_pos;
00695   u->y_pos = v->y_pos;
00696   u->z_pos = v->z_pos;
00697   u->u.rail.track = TRACK_BIT_DEPOT;
00698   u->vehstatus = v->vehstatus & ~VS_STOPPED;
00699 //  u->subtype = 0;
00700   SetMultiheaded(u);
00701   u->spritenum = v->spritenum + 1;
00702   u->cargo_type = v->cargo_type;
00703   u->cargo_subtype = v->cargo_subtype;
00704   u->cargo_cap = v->cargo_cap;
00705   u->u.rail.railtype = v->u.rail.railtype;
00706   if (building) v->SetNext(u);
00707   u->engine_type = v->engine_type;
00708   u->build_year = v->build_year;
00709   if (building) v->value >>= 1;
00710   u->value = v->value;
00711   u->cur_image = 0xAC2;
00712   u->random_bits = VehicleRandomBits();
00713   VehicleMove(u, false);
00714 }
00715 
00722 CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00723 {
00724   /* Check if the engine-type is valid (for the company) */
00725   if (!IsEngineBuildable(p1, VEH_TRAIN, _current_company)) return_cmd_error(STR_RAIL_VEHICLE_NOT_AVAILABLE);
00726 
00727   const Engine *e = GetEngine(p1);
00728   CommandCost value(EXPENSES_NEW_VEHICLES, e->GetCost());
00729 
00730   /* Engines with CT_INVALID should not be available */
00731   if (e->GetDefaultCargoType() == CT_INVALID) return CMD_ERROR;
00732 
00733   if (flags & DC_QUERY_COST) return value;
00734 
00735   /* Check if the train is actually being built in a depot belonging
00736    * to the company. Doesn't matter if only the cost is queried */
00737   if (!IsRailDepotTile(tile)) return CMD_ERROR;
00738   if (!IsTileOwner(tile, _current_company)) return CMD_ERROR;
00739 
00740   const RailVehicleInfo *rvi = RailVehInfo(p1);
00741   if (rvi->railveh_type == RAILVEH_WAGON) return CmdBuildRailWagon(p1, tile, flags);
00742 
00743   uint num_vehicles =
00744     (rvi->railveh_type == RAILVEH_MULTIHEAD ? 2 : 1) +
00745     CountArticulatedParts(p1, false);
00746 
00747   /* Check if depot and new engine uses the same kind of tracks *
00748    * We need to see if the engine got power on the tile to avoid eletric engines in non-electric depots */
00749   if (!HasPowerOnRail(rvi->railtype, GetRailType(tile))) return CMD_ERROR;
00750 
00751   /* Allow for the dual-heads and the articulated parts, plus one to "terminate" the list. */
00752   Vehicle **vl = AllocaM(Vehicle*, num_vehicles + 1);
00753   memset(vl, 0, sizeof(*vl) * (num_vehicles + 1));
00754 
00755   if (!Vehicle::AllocateList(vl, num_vehicles)) {
00756     return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
00757   }
00758 
00759   Vehicle *v = vl[0];
00760 
00761   UnitID unit_num = (flags & DC_AUTOREPLACE) ? 0 : GetFreeUnitNumber(VEH_TRAIN);
00762   if (unit_num > _settings_game.vehicle.max_trains) {
00763     return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
00764   }
00765 
00766   if (flags & DC_EXEC) {
00767     DiagDirection dir = GetRailDepotDirection(tile);
00768     int x = TileX(tile) * TILE_SIZE + _vehicle_initial_x_fract[dir];
00769     int y = TileY(tile) * TILE_SIZE + _vehicle_initial_y_fract[dir];
00770 
00771     v = new (v) Train();
00772     v->unitnumber = unit_num;
00773     v->direction = DiagDirToDir(dir);
00774     v->tile = tile;
00775     v->owner = _current_company;
00776     v->x_pos = x;
00777     v->y_pos = y;
00778     v->z_pos = GetSlopeZ(x, y);
00779 //    v->running_ticks = 0;
00780     v->u.rail.track = TRACK_BIT_DEPOT;
00781     v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
00782     v->spritenum = rvi->image_index;
00783     v->cargo_type = e->GetDefaultCargoType();
00784 //    v->cargo_subtype = 0;
00785     v->cargo_cap = rvi->capacity;
00786     v->max_speed = rvi->max_speed;
00787     v->value = value.GetCost();
00788     v->last_station_visited = INVALID_STATION;
00789 //    v->dest_tile = 0;
00790 
00791     v->engine_type = p1;
00792 
00793     v->reliability = e->reliability;
00794     v->reliability_spd_dec = e->reliability_spd_dec;
00795     v->max_age = e->lifelength * DAYS_IN_LEAP_YEAR;
00796 
00797     v->name = NULL;
00798     v->u.rail.railtype = rvi->railtype;
00799     _new_vehicle_id = v->index;
00800 
00801     v->service_interval = _settings_game.vehicle.servint_trains;
00802     v->date_of_last_service = _date;
00803     v->build_year = _cur_year;
00804     v->cur_image = 0xAC2;
00805     v->random_bits = VehicleRandomBits();
00806 
00807 //    v->vehicle_flags = 0;
00808     if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
00809 
00810     v->group_id = DEFAULT_GROUP;
00811 
00812 //    v->subtype = 0;
00813     SetFrontEngine(v);
00814     SetTrainEngine(v);
00815 
00816     VehicleMove(v, false);
00817 
00818     if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
00819       SetMultiheaded(v);
00820       AddRearEngineToMultiheadedTrain(vl[0], vl[1], true);
00821       /* Now we need to link the front and rear engines together
00822        * other_multiheaded_part is the pointer that links to the other half of the engine
00823        * vl[0] is the front and vl[1] is the rear
00824        */
00825       vl[0]->u.rail.other_multiheaded_part = vl[1];
00826       vl[1]->u.rail.other_multiheaded_part = vl[0];
00827     } else {
00828       AddArticulatedParts(vl, VEH_TRAIN);
00829     }
00830 
00831     TrainConsistChanged(v, false);
00832     UpdateTrainGroupID(v);
00833 
00834     if (!HasBit(p2, 1) && !(flags & DC_AUTOREPLACE)) { // check if the cars should be added to the new vehicle
00835       NormalizeTrainVehInDepot(v);
00836     }
00837 
00838     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
00839     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
00840     InvalidateWindow(WC_COMPANY, v->owner);
00841     if (IsLocalCompany()) {
00842       InvalidateAutoreplaceWindow(v->engine_type, v->group_id); // updates the replace Train window
00843     }
00844 
00845     GetCompany(_current_company)->num_engines[p1]++;
00846 
00847     CheckConsistencyOfArticulatedVehicle(v);
00848   }
00849 
00850   return value;
00851 }
00852 
00853 
00854 /* Check if all the wagons of the given train are in a depot, returns the
00855  * number of cars (including loco) then. If not it returns -1 */
00856 int CheckTrainInDepot(const Vehicle *v, bool needs_to_be_stopped)
00857 {
00858   TileIndex tile = v->tile;
00859 
00860   /* check if stopped in a depot */
00861   if (!IsRailDepotTile(tile) || v->cur_speed != 0) return -1;
00862 
00863   int count = 0;
00864   for (; v != NULL; v = v->Next()) {
00865     /* This count is used by the depot code to determine the number of engines
00866      * in the consist. Exclude articulated parts so that autoreplacing to
00867      * engines with more articulated parts than before works correctly.
00868      *
00869      * Also skip counting rear ends of multiheaded engines */
00870     if (!IsArticulatedPart(v) && !IsRearDualheaded(v)) count++;
00871     if (v->u.rail.track != TRACK_BIT_DEPOT || v->tile != tile ||
00872         (IsFrontEngine(v) && needs_to_be_stopped && !(v->vehstatus & VS_STOPPED))) {
00873       return -1;
00874     }
00875   }
00876 
00877   return count;
00878 }
00879 
00880 /* Used to check if the train is inside the depot and verifying that the VS_STOPPED flag is set */
00881 int CheckTrainStoppedInDepot(const Vehicle *v)
00882 {
00883   return CheckTrainInDepot(v, true);
00884 }
00885 
00886 /* Used to check if the train is inside the depot, but not checking the VS_STOPPED flag */
00887 inline bool CheckTrainIsInsideDepot(const Vehicle *v)
00888 {
00889   return CheckTrainInDepot(v, false) > 0;
00890 }
00891 
00898 static Vehicle *UnlinkWagon(Vehicle *v, Vehicle *first)
00899 {
00900   /* unlinking the first vehicle of the chain? */
00901   if (v == first) {
00902     v = GetNextVehicle(v);
00903     if (v == NULL) return NULL;
00904 
00905     if (IsTrainWagon(v)) SetFreeWagon(v);
00906 
00907     /* First can be an articulated engine, meaning GetNextVehicle() isn't
00908      * v->Next(). Thus set the next vehicle of the last articulated part
00909      * and the last articulated part is just before the next vehicle (v). */
00910     v->Previous()->SetNext(NULL);
00911 
00912     return v;
00913   }
00914 
00915   Vehicle *u;
00916   for (u = first; GetNextVehicle(u) != v; u = GetNextVehicle(u)) {}
00917   GetLastEnginePart(u)->SetNext(GetNextVehicle(v));
00918   return first;
00919 }
00920 
00921 static Vehicle *FindGoodVehiclePos(const Vehicle *src)
00922 {
00923   Vehicle *dst;
00924   EngineID eng = src->engine_type;
00925   TileIndex tile = src->tile;
00926 
00927   FOR_ALL_VEHICLES(dst) {
00928     if (dst->type == VEH_TRAIN && IsFreeWagon(dst) && dst->tile == tile && !HASBITS(dst->vehstatus, VS_CRASHED)) {
00929       /* check so all vehicles in the line have the same engine. */
00930       Vehicle *v = dst;
00931 
00932       while (v->engine_type == eng) {
00933         v = v->Next();
00934         if (v == NULL) return dst;
00935       }
00936     }
00937   }
00938 
00939   return NULL;
00940 }
00941 
00942 /*
00943  * add a vehicle v behind vehicle dest
00944  * use this function since it sets flags as needed
00945  */
00946 static void AddWagonToConsist(Vehicle *v, Vehicle *dest)
00947 {
00948   UnlinkWagon(v, v->First());
00949   if (dest == NULL) return;
00950 
00951   Vehicle *next = dest->Next();
00952   v->SetNext(NULL);
00953   dest->SetNext(v);
00954   v->SetNext(next);
00955   ClearFreeWagon(v);
00956   ClearFrontEngine(v);
00957 }
00958 
00959 /*
00960  * move around on the train so rear engines are placed correctly according to the other engines
00961  * always call with the front engine
00962  */
00963 static void NormaliseTrainConsist(Vehicle *v)
00964 {
00965   if (IsFreeWagon(v)) return;
00966 
00967   assert(IsFrontEngine(v));
00968 
00969   for (; v != NULL; v = GetNextVehicle(v)) {
00970     if (!IsMultiheaded(v) || !IsTrainEngine(v)) continue;
00971 
00972     /* make sure that there are no free cars before next engine */
00973     Vehicle *u;
00974     for (u = v; u->Next() != NULL && !IsTrainEngine(u->Next()); u = u->Next()) {}
00975 
00976     if (u == v->u.rail.other_multiheaded_part) continue;
00977     AddWagonToConsist(v->u.rail.other_multiheaded_part, u);
00978   }
00979 }
00980 
00990 CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00991 {
00992   VehicleID s = GB(p1, 0, 16);
00993   VehicleID d = GB(p1, 16, 16);
00994 
00995   if (!IsValidVehicleID(s)) return CMD_ERROR;
00996 
00997   Vehicle *src = GetVehicle(s);
00998 
00999   if (src->type != VEH_TRAIN || !CheckOwnership(src->owner)) return CMD_ERROR;
01000 
01001   /* Do not allow moving crashed vehicles inside the depot, it is likely to cause asserts later */
01002   if (HASBITS(src->vehstatus, VS_CRASHED)) return CMD_ERROR;
01003 
01004   /* if nothing is selected as destination, try and find a matching vehicle to drag to. */
01005   Vehicle *dst;
01006   if (d == INVALID_VEHICLE) {
01007     dst = IsTrainEngine(src) ? NULL : FindGoodVehiclePos(src);
01008   } else {
01009     if (!IsValidVehicleID(d)) return CMD_ERROR;
01010     dst = GetVehicle(d);
01011     if (dst->type != VEH_TRAIN || !CheckOwnership(dst->owner)) return CMD_ERROR;
01012 
01013     /* Do not allow appending to crashed vehicles, too */
01014     if (HASBITS(dst->vehstatus, VS_CRASHED)) return CMD_ERROR;
01015   }
01016 
01017   /* if an articulated part is being handled, deal with its parent vehicle */
01018   while (IsArticulatedPart(src)) src = src->Previous();
01019   if (dst != NULL) {
01020     while (IsArticulatedPart(dst)) dst = dst->Previous();
01021   }
01022 
01023   /* don't move the same vehicle.. */
01024   if (src == dst) return CommandCost();
01025 
01026   /* locate the head of the two chains */
01027   Vehicle *src_head = src->First();
01028   Vehicle *dst_head;
01029   if (dst != NULL) {
01030     dst_head = dst->First();
01031     if (dst_head->tile != src_head->tile) return CMD_ERROR;
01032     /* Now deal with articulated part of destination wagon */
01033     dst = GetLastEnginePart(dst);
01034   } else {
01035     dst_head = NULL;
01036   }
01037 
01038   if (IsRearDualheaded(src)) return_cmd_error(STR_REAR_ENGINE_FOLLOW_FRONT_ERROR);
01039 
01040   /* when moving all wagons, we can't have the same src_head and dst_head */
01041   if (HasBit(p2, 0) && src_head == dst_head) return CommandCost();
01042 
01043   /* check if all vehicles in the source train are stopped inside a depot. */
01044   int src_len = CheckTrainStoppedInDepot(src_head);
01045   if (src_len < 0) return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01046 
01047   if ((flags & DC_AUTOREPLACE) == 0) {
01048     /* Check whether there are more than 'max_len' train units (articulated parts and rear heads do not count) in the new chain */
01049     int max_len = _settings_game.vehicle.mammoth_trains ? 100 : 10;
01050 
01051     /* check the destination row if the source and destination aren't the same. */
01052     if (src_head != dst_head) {
01053       int dst_len = 0;
01054 
01055       if (dst_head != NULL) {
01056         /* check if all vehicles in the dest train are stopped. */
01057         dst_len = CheckTrainStoppedInDepot(dst_head);
01058         if (dst_len < 0) return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01059       }
01060 
01061       /* We are moving between rows, so only count the wagons from the source
01062        * row that are being moved. */
01063       if (HasBit(p2, 0)) {
01064         const Vehicle *u;
01065         for (u = src_head; u != src && u != NULL; u = GetNextVehicle(u))
01066           src_len--;
01067       } else {
01068         /* If moving only one vehicle, just count that. */
01069         src_len = 1;
01070       }
01071 
01072       if (src_len + dst_len > max_len) {
01073         /* Abort if we're adding too many wagons to a train. */
01074         if (dst_head != NULL && IsFrontEngine(dst_head)) return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01075         /* Abort if we're making a train on a new row. */
01076         if (dst_head == NULL && IsTrainEngine(src)) return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01077       }
01078     } else {
01079       /* Abort if we're creating a new train on an existing row. */
01080       if (src_len > max_len && src == src_head && IsTrainEngine(GetNextVehicle(src_head)))
01081         return_cmd_error(STR_8819_TRAIN_TOO_LONG);
01082     }
01083   }
01084 
01085   /* moving a loco to a new line?, then we need to assign a unitnumber. */
01086   if (dst == NULL && !IsFrontEngine(src) && IsTrainEngine(src)) {
01087     UnitID unit_num = ((flags & DC_AUTOREPLACE) != 0 ? 0 : GetFreeUnitNumber(VEH_TRAIN));
01088     if (unit_num > _settings_game.vehicle.max_trains)
01089       return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
01090 
01091     if (flags & DC_EXEC) src->unitnumber = unit_num;
01092   }
01093 
01094   /* When we move the front vehicle, the second vehicle might need a unitnumber */
01095   if (!HasBit(p2, 0) && (IsFreeWagon(src) || (IsFrontEngine(src) && dst == NULL)) && (flags & DC_AUTOREPLACE) == 0) {
01096     Vehicle *second = GetNextUnit(src);
01097     if (second != NULL && IsTrainEngine(second) && GetFreeUnitNumber(VEH_TRAIN) > _settings_game.vehicle.max_trains) {
01098       return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
01099     }
01100   }
01101 
01102   /*
01103    * Check whether the vehicles in the source chain are in the destination
01104    * chain. This can easily be done by checking whether the first vehicle
01105    * of the source chain is in the destination chain as the Next/Previous
01106    * pointers always make a doubly linked list of it where the assumption
01107    * v->Next()->Previous() == v holds (assuming v->Next() != NULL).
01108    */
01109   bool src_in_dst = false;
01110   for (Vehicle *v = dst_head; !src_in_dst && v != NULL; v = v->Next()) src_in_dst = v == src;
01111 
01112   /*
01113    * If the source chain is in the destination chain then the user is
01114    * only reordering the vehicles, thus not attaching a new vehicle.
01115    * Therefor the 'allow wagon attach' callback does not need to be
01116    * called. If it would be called strange things would happen because
01117    * one 'attaches' an already 'attached' vehicle causing more trouble
01118    * than it actually solves (infinite loops and such).
01119    */
01120   if (dst_head != NULL && !src_in_dst && (flags & DC_AUTOREPLACE) == 0) {
01121     /*
01122      * When performing the 'allow wagon attach' callback, we have to check
01123      * that for each and every wagon, not only the first one. This means
01124      * that we have to test one wagon, attach it to the train and then test
01125      * the next wagon till we have reached the end. We have to restore it
01126      * to the state it was before we 'tried' attaching the train when the
01127      * attaching fails or succeeds because we are not 'only' doing this
01128      * in the DC_EXEC state.
01129      */
01130     Vehicle *dst_tail = dst_head;
01131     while (dst_tail->Next() != NULL) dst_tail = dst_tail->Next();
01132 
01133     Vehicle *orig_tail = dst_tail;
01134     Vehicle *next_to_attach = src;
01135     Vehicle *src_previous = src->Previous();
01136 
01137     while (next_to_attach != NULL) {
01138       /* Don't check callback for articulated or rear dual headed parts */
01139       if (!IsArticulatedPart(next_to_attach) && !IsRearDualheaded(next_to_attach)) {
01140         /* Back up and clear the first_engine data to avoid using wagon override group */
01141         EngineID first_engine = next_to_attach->u.rail.first_engine;
01142         next_to_attach->u.rail.first_engine = INVALID_ENGINE;
01143 
01144         uint16 callback = GetVehicleCallbackParent(CBID_TRAIN_ALLOW_WAGON_ATTACH, 0, 0, dst_head->engine_type, next_to_attach, dst_head);
01145 
01146         /* Restore original first_engine data */
01147         next_to_attach->u.rail.first_engine = first_engine;
01148 
01149         if (callback != CALLBACK_FAILED) {
01150           StringID error = STR_NULL;
01151 
01152           if (callback == 0xFD) error = STR_INCOMPATIBLE_RAIL_TYPES;
01153           if (callback < 0xFD) error = GetGRFStringID(GetEngineGRFID(dst_head->engine_type), 0xD000 + callback);
01154 
01155           if (error != STR_NULL) {
01156             /*
01157              * The attaching is not allowed. In this case 'next_to_attach'
01158              * can contain some vehicles of the 'source' and the destination
01159              * train can have some too. We 'just' add the to-be added wagons
01160              * to the chain and then split it where it was previously
01161              * separated, i.e. the tail of the original destination train.
01162              * Furthermore the 'previous' link of the original source vehicle needs
01163              * to be restored, otherwise the train goes missing in the depot.
01164              */
01165             dst_tail->SetNext(next_to_attach);
01166             orig_tail->SetNext(NULL);
01167             if (src_previous != NULL) src_previous->SetNext(src);
01168 
01169             return_cmd_error(error);
01170           }
01171         }
01172       }
01173 
01174       /* Only check further wagons if told to move the chain */
01175       if (!HasBit(p2, 0)) break;
01176 
01177       /*
01178        * Adding a next wagon to the chain so we can test the other wagons.
01179        * First 'take' the first wagon from 'next_to_attach' and move it
01180        * to the next wagon. Then add that to the tail of the destination
01181        * train and update the tail with the new vehicle.
01182        */
01183       Vehicle *to_add = next_to_attach;
01184       next_to_attach = next_to_attach->Next();
01185 
01186       to_add->SetNext(NULL);
01187       dst_tail->SetNext(to_add);
01188       dst_tail = dst_tail->Next();
01189     }
01190 
01191     /*
01192      * When we reach this the attaching is allowed. It also means that the
01193      * chain of vehicles to attach is empty, so we do not need to merge that.
01194      * This means only the splitting needs to be done.
01195      * Furthermore the 'previous' link of the original source vehicle needs
01196      * to be restored, otherwise the train goes missing in the depot.
01197      */
01198     orig_tail->SetNext(NULL);
01199     if (src_previous != NULL) src_previous->SetNext(src);
01200   }
01201 
01202   /* do it? */
01203   if (flags & DC_EXEC) {
01204     /* If we move the front Engine and if the second vehicle is not an engine
01205        add the whole vehicle to the DEFAULT_GROUP */
01206     if (IsFrontEngine(src) && !IsDefaultGroupID(src->group_id)) {
01207       Vehicle *v = GetNextVehicle(src);
01208 
01209       if (v != NULL && IsTrainEngine(v)) {
01210         v->group_id   = src->group_id;
01211         src->group_id = DEFAULT_GROUP;
01212       }
01213     }
01214 
01215     if (HasBit(p2, 0)) {
01216       /* unlink ALL wagons */
01217       if (src != src_head) {
01218         Vehicle *v = src_head;
01219         while (GetNextVehicle(v) != src) v = GetNextVehicle(v);
01220         GetLastEnginePart(v)->SetNext(NULL);
01221       } else {
01222         InvalidateWindowData(WC_VEHICLE_DEPOT, src_head->tile); // We removed a line
01223         src_head = NULL;
01224       }
01225     } else {
01226       /* if moving within the same chain, dont use dst_head as it may get invalidated */
01227       if (src_head == dst_head) dst_head = NULL;
01228       /* unlink single wagon from linked list */
01229       src_head = UnlinkWagon(src, src_head);
01230       GetLastEnginePart(src)->SetNext(NULL);
01231     }
01232 
01233     if (dst == NULL) {
01234       /* We make a new line in the depot, so we know already that we invalidate the window data */
01235       InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01236 
01237       /* move the train to an empty line. for locomotives, we set the type to TS_Front. for wagons, 4. */
01238       if (IsTrainEngine(src)) {
01239         if (!IsFrontEngine(src)) {
01240           /* setting the type to 0 also involves setting up the orders field. */
01241           SetFrontEngine(src);
01242           assert(src->orders.list == NULL);
01243 
01244           /* Decrease the engines number of the src engine_type */
01245           if (!IsDefaultGroupID(src->group_id) && IsValidGroupID(src->group_id)) {
01246             GetGroup(src->group_id)->num_engines[src->engine_type]--;
01247           }
01248 
01249           /* If we move an engine to a new line affect it to the DEFAULT_GROUP */
01250           src->group_id = DEFAULT_GROUP;
01251         }
01252       } else {
01253         SetFreeWagon(src);
01254       }
01255       dst_head = src;
01256     } else {
01257       if (IsFrontEngine(src)) {
01258         /* the vehicle was previously a loco. need to free the order list and delete vehicle windows etc. */
01259         DeleteWindowById(WC_VEHICLE_VIEW, src->index);
01260         DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
01261         DeleteWindowById(WC_VEHICLE_REFIT, src->index);
01262         DeleteWindowById(WC_VEHICLE_DETAILS, src->index);
01263         DeleteWindowById(WC_VEHICLE_TIMETABLE, src->index);
01264         DeleteVehicleOrders(src);
01265         RemoveVehicleFromGroup(src);
01266       }
01267 
01268       if (IsFrontEngine(src) || IsFreeWagon(src)) {
01269         InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
01270         ClearFrontEngine(src);
01271         ClearFreeWagon(src);
01272         src->unitnumber = 0; // doesn't occupy a unitnumber anymore.
01273       }
01274 
01275       /* link in the wagon(s) in the chain. */
01276       {
01277         Vehicle *v;
01278 
01279         for (v = src; GetNextVehicle(v) != NULL; v = GetNextVehicle(v)) {}
01280         GetLastEnginePart(v)->SetNext(dst->Next());
01281       }
01282       dst->SetNext(src);
01283     }
01284 
01285     if (src->u.rail.other_multiheaded_part != NULL) {
01286       if (src->u.rail.other_multiheaded_part == src_head) {
01287         src_head = src_head->Next();
01288       }
01289       AddWagonToConsist(src->u.rail.other_multiheaded_part, src);
01290     }
01291 
01292     /* If there is an engine behind first_engine we moved away, it should become new first_engine
01293      * To do this, CmdMoveRailVehicle must be called once more
01294      * we can't loop forever here because next time we reach this line we will have a front engine */
01295     if (src_head != NULL && !IsFrontEngine(src_head) && IsTrainEngine(src_head)) {
01296       /* As in CmdMoveRailVehicle src_head->group_id will be equal to DEFAULT_GROUP
01297        * we need to save the group and reaffect it to src_head */
01298       const GroupID tmp_g = src_head->group_id;
01299       CmdMoveRailVehicle(0, flags, src_head->index | (INVALID_VEHICLE << 16), 1, text);
01300       SetTrainGroupID(src_head, tmp_g);
01301       src_head = NULL; // don't do anything more to this train since the new call will do it
01302     }
01303 
01304     if (src_head != NULL) {
01305       NormaliseTrainConsist(src_head);
01306       TrainConsistChanged(src_head, false);
01307       UpdateTrainGroupID(src_head);
01308       if (IsFrontEngine(src_head)) {
01309         /* Update the refit button and window */
01310         InvalidateWindow(WC_VEHICLE_REFIT, src_head->index);
01311         InvalidateWindowWidget(WC_VEHICLE_VIEW, src_head->index, VVW_WIDGET_REFIT_VEH);
01312       }
01313       /* Update the depot window */
01314       InvalidateWindow(WC_VEHICLE_DEPOT, src_head->tile);
01315     }
01316 
01317     if (dst_head != NULL) {
01318       NormaliseTrainConsist(dst_head);
01319       TrainConsistChanged(dst_head, false);
01320       UpdateTrainGroupID(dst_head);
01321       if (IsFrontEngine(dst_head)) {
01322         /* Update the refit button and window */
01323         InvalidateWindowWidget(WC_VEHICLE_VIEW, dst_head->index, VVW_WIDGET_REFIT_VEH);
01324         InvalidateWindow(WC_VEHICLE_REFIT, dst_head->index);
01325       }
01326       /* Update the depot window */
01327       InvalidateWindow(WC_VEHICLE_DEPOT, dst_head->tile);
01328     }
01329 
01330     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01331   }
01332 
01333   return CommandCost();
01334 }
01335 
01345 CommandCost CmdSellRailWagon(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01346 {
01347   /* Check if we deleted a vehicle window */
01348   Window *w = NULL;
01349 
01350   if (!IsValidVehicleID(p1) || p2 > 1) return CMD_ERROR;
01351 
01352   Vehicle *v = GetVehicle(p1);
01353 
01354   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01355 
01356   if (HASBITS(v->vehstatus, VS_CRASHED)) return_cmd_error(STR_CAN_T_SELL_DESTROYED_VEHICLE);
01357 
01358   while (IsArticulatedPart(v)) v = v->Previous();
01359   Vehicle *first = v->First();
01360 
01361   /* make sure the vehicle is stopped in the depot */
01362   if (CheckTrainStoppedInDepot(first) < 0) {
01363     return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01364   }
01365 
01366   if (IsRearDualheaded(v)) return_cmd_error(STR_REAR_ENGINE_FOLLOW_FRONT_ERROR);
01367 
01368   if (flags & DC_EXEC) {
01369     if (v == first && IsFrontEngine(first)) {
01370       DeleteWindowById(WC_VEHICLE_VIEW, first->index);
01371       DeleteWindowById(WC_VEHICLE_ORDERS, first->index);
01372       DeleteWindowById(WC_VEHICLE_REFIT, first->index);
01373       DeleteWindowById(WC_VEHICLE_DETAILS, first->index);
01374       DeleteWindowById(WC_VEHICLE_TIMETABLE, first->index);
01375     }
01376     InvalidateWindow(WC_VEHICLE_DEPOT, first->tile);
01377     InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
01378   }
01379 
01380   CommandCost cost(EXPENSES_NEW_VEHICLES);
01381   switch (p2) {
01382     case 0: { // Delete given wagon
01383       bool switch_engine = false;    // update second wagon to engine?
01384 
01385       /* 1. Delete the engine, if it is dualheaded also delete the matching
01386        * rear engine of the loco (from the point of deletion onwards) */
01387       Vehicle *rear = (IsMultiheaded(v) &&
01388         IsTrainEngine(v)) ? v->u.rail.other_multiheaded_part : NULL;
01389 
01390       if (rear != NULL) {
01391         cost.AddCost(-rear->value);
01392         if (flags & DC_EXEC) {
01393           UnlinkWagon(rear, first);
01394           delete rear;
01395         }
01396       }
01397 
01398       /* 2. We are selling the front vehicle, some special action might be required
01399        * here, so take attention */
01400       if (v == first) {
01401         Vehicle *new_f = GetNextVehicle(first);
01402 
01403         /* 2.2 If there are wagons present after the deleted front engine, check
01404          * if the second wagon (which will be first) is an engine. If it is one,
01405          * promote it as a new train, retaining the unitnumber, orders */
01406         if (new_f != NULL && IsTrainEngine(new_f)) {
01407           if (IsTrainEngine(first)) {
01408             /* Let the new front engine take over the setup of the old engine */
01409             switch_engine = true;
01410 
01411             if (flags & DC_EXEC) {
01412               /* Make sure the group counts stay correct. */
01413               new_f->group_id        = first->group_id;
01414               first->group_id        = DEFAULT_GROUP;
01415 
01416               /* Copy orders (by sharing) */
01417               new_f->orders.list     = first->orders.list;
01418               new_f->AddToShared(first);
01419               DeleteVehicleOrders(first);
01420 
01421               /* Copy other important data from the front engine */
01422               new_f->CopyVehicleConfigAndStatistics(first);
01423 
01424               /* If we deleted a window then open a new one for the 'new' train */
01425               if (IsLocalCompany() && w != NULL) ShowVehicleViewWindow(new_f);
01426             }
01427           } else {
01428             /* We are selling a free wagon, and construct a new train at the same time.
01429              * This needs lots of extra checks (e.g. train limit), which are done by first moving
01430              * the remaining vehicles to a new row */
01431             cost.AddCost(DoCommand(0, new_f->index | INVALID_VEHICLE << 16, 1, flags, CMD_MOVE_RAIL_VEHICLE));
01432             if (cost.Failed()) return cost;
01433           }
01434         }
01435       }
01436 
01437       /* 3. Delete the requested wagon */
01438       cost.AddCost(-v->value);
01439       if (flags & DC_EXEC) {
01440         first = UnlinkWagon(v, first);
01441         delete v;
01442 
01443         /* 4 If the second wagon was an engine, update it to front_engine
01444          * which UnlinkWagon() has changed to TS_Free_Car */
01445         if (switch_engine) SetFrontEngine(first);
01446 
01447         /* 5. If the train still exists, update its acceleration, window, etc. */
01448         if (first != NULL) {
01449           NormaliseTrainConsist(first);
01450           TrainConsistChanged(first, false);
01451           UpdateTrainGroupID(first);
01452           if (IsFrontEngine(first)) InvalidateWindow(WC_VEHICLE_REFIT, first->index);
01453         }
01454 
01455       }
01456     } break;
01457     case 1: { // Delete wagon and all wagons after it given certain criteria
01458       /* Start deleting every vehicle after the selected one
01459        * If we encounter a matching rear-engine to a front-engine
01460        * earlier in the chain (before deletion), leave it alone */
01461       for (Vehicle *tmp; v != NULL; v = tmp) {
01462         tmp = GetNextVehicle(v);
01463 
01464         if (IsMultiheaded(v)) {
01465           if (IsTrainEngine(v)) {
01466             /* We got a front engine of a multiheaded set. Now we will sell the rear end too */
01467             Vehicle *rear = v->u.rail.other_multiheaded_part;
01468 
01469             if (rear != NULL) {
01470               cost.AddCost(-rear->value);
01471 
01472               /* If this is a multiheaded vehicle with nothing
01473                * between the parts, tmp will be pointing to the
01474                * rear part, which is unlinked from the train and
01475                * deleted here. However, because tmp has already
01476                * been set it needs to be updated now so that the
01477                * loop never sees the rear part. */
01478               if (tmp == rear) tmp = GetNextVehicle(tmp);
01479 
01480               if (flags & DC_EXEC) {
01481                 first = UnlinkWagon(rear, first);
01482                 delete rear;
01483               }
01484             }
01485           } else if (v->u.rail.other_multiheaded_part != NULL) {
01486             /* The front to this engine is earlier in this train. Do nothing */
01487             continue;
01488           }
01489         }
01490 
01491         cost.AddCost(-v->value);
01492         if (flags & DC_EXEC) {
01493           first = UnlinkWagon(v, first);
01494           delete v;
01495         }
01496       }
01497 
01498       /* 3. If it is still a valid train after selling, update its acceleration and cached values */
01499       if (flags & DC_EXEC && first != NULL) {
01500         NormaliseTrainConsist(first);
01501         TrainConsistChanged(first, false);
01502         UpdateTrainGroupID(first);
01503         InvalidateWindow(WC_VEHICLE_REFIT, first->index);
01504       }
01505     } break;
01506   }
01507   return cost;
01508 }
01509 
01510 void Train::UpdateDeltaXY(Direction direction)
01511 {
01512 #define MKIT(a, b, c, d) ((a & 0xFF) << 24) | ((b & 0xFF) << 16) | ((c & 0xFF) << 8) | ((d & 0xFF) << 0)
01513   static const uint32 _delta_xy_table[8] = {
01514     MKIT(3, 3, -1, -1),
01515     MKIT(3, 7, -1, -3),
01516     MKIT(3, 3, -1, -1),
01517     MKIT(7, 3, -3, -1),
01518     MKIT(3, 3, -1, -1),
01519     MKIT(3, 7, -1, -3),
01520     MKIT(3, 3, -1, -1),
01521     MKIT(7, 3, -3, -1),
01522   };
01523 #undef MKIT
01524 
01525   uint32 x = _delta_xy_table[direction];
01526   this->x_offs        = GB(x,  0, 8);
01527   this->y_offs        = GB(x,  8, 8);
01528   this->x_extent      = GB(x, 16, 8);
01529   this->y_extent      = GB(x, 24, 8);
01530   this->z_extent      = 6;
01531 }
01532 
01533 static void UpdateVarsAfterSwap(Vehicle *v)
01534 {
01535   v->UpdateDeltaXY(v->direction);
01536   v->cur_image = v->GetImage(v->direction);
01537   VehicleMove(v, true);
01538 }
01539 
01540 static inline void SetLastSpeed(Vehicle *v, int spd)
01541 {
01542   int old = v->u.rail.last_speed;
01543   if (spd != old) {
01544     v->u.rail.last_speed = spd;
01545     if (_settings_client.gui.vehicle_speed || (old == 0) != (spd == 0)) {
01546       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01547     }
01548   }
01549 }
01550 
01552 static void MarkTrainAsStuck(Vehicle *v)
01553 {
01554   if (!HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
01555     /* It is the first time the problem occured, set the "train stuck" flag. */
01556     SetBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01557     v->load_unload_time_rem = 0;
01558 
01559     /* Stop train */
01560     v->cur_speed = 0;
01561     v->subspeed = 0;
01562     SetLastSpeed(v, 0);
01563 
01564     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01565   }
01566 }
01567 
01568 static void SwapTrainFlags(uint16 *swap_flag1, uint16 *swap_flag2)
01569 {
01570   uint16 flag1 = *swap_flag1;
01571   uint16 flag2 = *swap_flag2;
01572 
01573   /* Clear the flags */
01574   ClrBit(*swap_flag1, VRF_GOINGUP);
01575   ClrBit(*swap_flag1, VRF_GOINGDOWN);
01576   ClrBit(*swap_flag2, VRF_GOINGUP);
01577   ClrBit(*swap_flag2, VRF_GOINGDOWN);
01578 
01579   /* Reverse the rail-flags (if needed) */
01580   if (HasBit(flag1, VRF_GOINGUP)) {
01581     SetBit(*swap_flag2, VRF_GOINGDOWN);
01582   } else if (HasBit(flag1, VRF_GOINGDOWN)) {
01583     SetBit(*swap_flag2, VRF_GOINGUP);
01584   }
01585   if (HasBit(flag2, VRF_GOINGUP)) {
01586     SetBit(*swap_flag1, VRF_GOINGDOWN);
01587   } else if (HasBit(flag2, VRF_GOINGDOWN)) {
01588     SetBit(*swap_flag1, VRF_GOINGUP);
01589   }
01590 }
01591 
01592 static void ReverseTrainSwapVeh(Vehicle *v, int l, int r)
01593 {
01594   Vehicle *a, *b;
01595 
01596   /* locate vehicles to swap */
01597   for (a = v; l != 0; l--) a = a->Next();
01598   for (b = v; r != 0; r--) b = b->Next();
01599 
01600   if (a != b) {
01601     /* swap the hidden bits */
01602     {
01603       uint16 tmp = (a->vehstatus & ~VS_HIDDEN) | (b->vehstatus&VS_HIDDEN);
01604       b->vehstatus = (b->vehstatus & ~VS_HIDDEN) | (a->vehstatus&VS_HIDDEN);
01605       a->vehstatus = tmp;
01606     }
01607 
01608     Swap(a->u.rail.track, b->u.rail.track);
01609     Swap(a->direction,    b->direction);
01610 
01611     /* toggle direction */
01612     if (a->u.rail.track != TRACK_BIT_DEPOT) a->direction = ReverseDir(a->direction);
01613     if (b->u.rail.track != TRACK_BIT_DEPOT) b->direction = ReverseDir(b->direction);
01614 
01615     Swap(a->x_pos, b->x_pos);
01616     Swap(a->y_pos, b->y_pos);
01617     Swap(a->tile,  b->tile);
01618     Swap(a->z_pos, b->z_pos);
01619 
01620     SwapTrainFlags(&a->u.rail.flags, &b->u.rail.flags);
01621 
01622     /* update other vars */
01623     UpdateVarsAfterSwap(a);
01624     UpdateVarsAfterSwap(b);
01625 
01626     /* call the proper EnterTile function unless we are in a wormhole */
01627     if (a->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
01628     if (b->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(b, b->tile, b->x_pos, b->y_pos);
01629   } else {
01630     if (a->u.rail.track != TRACK_BIT_DEPOT) a->direction = ReverseDir(a->direction);
01631     UpdateVarsAfterSwap(a);
01632 
01633     if (a->u.rail.track != TRACK_BIT_WORMHOLE) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
01634   }
01635 
01636   /* Update train's power incase tiles were different rail type */
01637   TrainPowerChanged(v);
01638 }
01639 
01640 
01646 static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
01647 {
01648   return (v->type == VEH_TRAIN) ? v : NULL;
01649 }
01650 
01651 
01658 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
01659 {
01660   /* not a train || not front engine || crashed */
01661   if (v->type != VEH_TRAIN || !IsFrontEngine(v) || v->vehstatus & VS_CRASHED) return NULL;
01662 
01663   TileIndex tile = *(TileIndex*)data;
01664 
01665   if (TrainApproachingCrossingTile(v) != tile) return NULL;
01666 
01667   return v;
01668 }
01669 
01670 
01677 static bool TrainApproachingCrossing(TileIndex tile)
01678 {
01679   assert(IsLevelCrossingTile(tile));
01680 
01681   DiagDirection dir = AxisToDiagDir(GetCrossingRailAxis(tile));
01682   TileIndex tile_from = tile + TileOffsByDiagDir(dir);
01683 
01684   if (HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum)) return true;
01685 
01686   dir = ReverseDiagDir(dir);
01687   tile_from = tile + TileOffsByDiagDir(dir);
01688 
01689   return HasVehicleOnPos(tile_from, &tile, &TrainApproachingCrossingEnum);
01690 }
01691 
01692 
01699 void UpdateLevelCrossing(TileIndex tile, bool sound)
01700 {
01701   assert(IsLevelCrossingTile(tile));
01702 
01703   /* train on crossing || train approaching crossing || reserved */
01704   bool new_state = HasVehicleOnPos(tile, NULL, &TrainOnTileEnum) || TrainApproachingCrossing(tile) || GetCrossingReservation(tile);
01705 
01706   if (new_state != IsCrossingBarred(tile)) {
01707     if (new_state && sound) {
01708       SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01709     }
01710     SetCrossingBarred(tile, new_state);
01711     MarkTileDirtyByTile(tile);
01712   }
01713 }
01714 
01715 
01721 static inline void MaybeBarCrossingWithSound(TileIndex tile)
01722 {
01723   if (!IsCrossingBarred(tile)) {
01724     BarCrossing(tile);
01725     SndPlayTileFx(SND_0E_LEVEL_CROSSING, tile);
01726     MarkTileDirtyByTile(tile);
01727   }
01728 }
01729 
01730 
01736 static void AdvanceWagonsBeforeSwap(Vehicle *v)
01737 {
01738   Vehicle *base = v;
01739   Vehicle *first = base;                    // first vehicle to move
01740   Vehicle *last = GetLastVehicleInChain(v); // last vehicle to move
01741   uint length = CountVehiclesInChain(v);
01742 
01743   while (length > 2) {
01744     last = last->Previous();
01745     first = first->Next();
01746 
01747     int differential = base->u.rail.cached_veh_length - last->u.rail.cached_veh_length;
01748 
01749     /* do not update images now
01750      * negative differential will be handled in AdvanceWagonsAfterSwap() */
01751     for (int i = 0; i < differential; i++) TrainController(first, last->Next());
01752 
01753     base = first; // == base->Next()
01754     length -= 2;
01755   }
01756 }
01757 
01758 
01764 static void AdvanceWagonsAfterSwap(Vehicle *v)
01765 {
01766   /* first of all, fix the situation when the train was entering a depot */
01767   Vehicle *dep = v; // last vehicle in front of just left depot
01768   while (dep->Next() != NULL && (dep->u.rail.track == TRACK_BIT_DEPOT || dep->Next()->u.rail.track != TRACK_BIT_DEPOT)) {
01769     dep = dep->Next(); // find first vehicle outside of a depot, with next vehicle inside a depot
01770   }
01771 
01772   Vehicle *leave = dep->Next(); // first vehicle in a depot we are leaving now
01773 
01774   if (leave != NULL) {
01775     /* 'pull' next wagon out of the depot, so we won't miss it (it could stay in depot forever) */
01776     int d = TicksToLeaveDepot(dep);
01777 
01778     if (d <= 0) {
01779       leave->vehstatus &= ~VS_HIDDEN; // move it out of the depot
01780       leave->u.rail.track = TrackToTrackBits(GetRailDepotTrack(leave->tile));
01781       for (int i = 0; i >= d; i--) TrainController(leave, NULL); // maybe move it, and maybe let another wagon leave
01782     }
01783   } else {
01784     dep = NULL; // no vehicle in a depot, so no vehicle leaving a depot
01785   }
01786 
01787   Vehicle *base = v;
01788   Vehicle *first = base;                    // first vehicle to move
01789   Vehicle *last = GetLastVehicleInChain(v); // last vehicle to move
01790   uint length = CountVehiclesInChain(v);
01791 
01792   /* we have to make sure all wagons that leave a depot because of train reversing are moved coorectly
01793    * they have already correct spacing, so we have to make sure they are moved how they should */
01794   bool nomove = (dep == NULL); // if there is no vehicle leaving a depot, limit the number of wagons moved immediatelly
01795 
01796   while (length > 2) {
01797     /* we reached vehicle (originally) in front of a depot, stop now
01798      * (we would move wagons that are alredy moved with new wagon length) */
01799     if (base == dep) break;
01800 
01801     /* the last wagon was that one leaving a depot, so do not move it anymore */
01802     if (last == dep) nomove = true;
01803 
01804     last = last->Previous();
01805     first = first->Next();
01806 
01807     int differential = last->u.rail.cached_veh_length - base->u.rail.cached_veh_length;
01808 
01809     /* do not update images now */
01810     for (int i = 0; i < differential; i++) TrainController(first, (nomove ? last->Next() : NULL));
01811 
01812     base = first; // == base->Next()
01813     length -= 2;
01814   }
01815 }
01816 
01817 
01818 static void ReverseTrainDirection(Vehicle *v)
01819 {
01820   if (IsRailDepotTile(v->tile)) {
01821     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01822   }
01823 
01824   /* Clear path reservation in front. */
01825   FreeTrainTrackReservation(v);
01826 
01827   /* Check if we were approaching a rail/road-crossing */
01828   TileIndex crossing = TrainApproachingCrossingTile(v);
01829 
01830   /* count number of vehicles */
01831   int r = CountVehiclesInChain(v) - 1;  // number of vehicles - 1
01832 
01833   AdvanceWagonsBeforeSwap(v);
01834 
01835   /* swap start<>end, start+1<>end-1, ... */
01836   int l = 0;
01837   do {
01838     ReverseTrainSwapVeh(v, l++, r--);
01839   } while (l <= r);
01840 
01841   AdvanceWagonsAfterSwap(v);
01842 
01843   if (IsRailDepotTile(v->tile)) {
01844     InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
01845   }
01846 
01847   ToggleBit(v->u.rail.flags, VRF_TOGGLE_REVERSE);
01848 
01849   ClrBit(v->u.rail.flags, VRF_REVERSING);
01850 
01851   /* recalculate cached data */
01852   TrainConsistChanged(v, true);
01853 
01854   /* update all images */
01855   for (Vehicle *u = v; u != NULL; u = u->Next()) u->cur_image = u->GetImage(u->direction);
01856 
01857   /* update crossing we were approaching */
01858   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
01859 
01860   /* maybe we are approaching crossing now, after reversal */
01861   crossing = TrainApproachingCrossingTile(v);
01862   if (crossing != INVALID_TILE) MaybeBarCrossingWithSound(crossing);
01863 
01864   /* If we are inside a depot after reversing, don't bother with path reserving. */
01865   if (v->u.rail.track & TRACK_BIT_DEPOT) {
01866     /* Can't be stuck here as inside a depot is always a safe tile. */
01867     if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
01868     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01869     return;
01870   }
01871 
01872   /* TrainExitDir does not always produce the desired dir for depots and
01873    * tunnels/bridges that is needed for UpdateSignalsOnSegment. */
01874   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
01875   if (IsRailDepotTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE)) dir = INVALID_DIAGDIR;
01876 
01877   if (UpdateSignalsOnSegment(v->tile, dir, v->owner) == SIGSEG_PBS || _settings_game.pf.reserve_paths) {
01878     /* If we are currently on a tile with conventional signals, we can't treat the
01879      * current tile as a safe tile or we would enter a PBS block without a reservation. */
01880     bool first_tile_okay = !(IsTileType(v->tile, MP_RAILWAY) &&
01881       HasSignalOnTrackdir(v->tile, GetVehicleTrackdir(v)) &&
01882       !IsPbsSignal(GetSignalType(v->tile, FindFirstTrack(v->u.rail.track))));
01883 
01884     if (IsRailwayStationTile(v->tile)) SetRailwayStationPlatformReservation(v->tile, TrackdirToExitdir(GetVehicleTrackdir(v)), true);
01885     if (TryPathReserve(v, false, first_tile_okay)) {
01886       /* Do a look-ahead now in case our current tile was already a safe tile. */
01887       CheckNextTrainTile(v);
01888     } else if (v->current_order.GetType() != OT_LOADING) {
01889       /* Do not wait for a way out when we're still loading */
01890       MarkTrainAsStuck(v);
01891     }
01892   } else if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
01893     /* A train not inside a PBS block can't be stuck. */
01894     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
01895     v->load_unload_time_rem = 0;
01896   }
01897 }
01898 
01905 CommandCost CmdReverseTrainDirection(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01906 {
01907   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01908 
01909   Vehicle *v = GetVehicle(p1);
01910 
01911   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01912 
01913   if (p2 != 0) {
01914     /* turn a single unit around */
01915 
01916     if (IsMultiheaded(v) || HasBit(EngInfo(v->engine_type)->callbackmask, CBM_VEHICLE_ARTIC_ENGINE)) {
01917       return_cmd_error(STR_ONLY_TURN_SINGLE_UNIT);
01918     }
01919 
01920     Vehicle *front = v->First();
01921     /* make sure the vehicle is stopped in the depot */
01922     if (CheckTrainStoppedInDepot(front) < 0) {
01923       return_cmd_error(STR_881A_TRAINS_CAN_ONLY_BE_ALTERED);
01924     }
01925 
01926     if (flags & DC_EXEC) {
01927       ToggleBit(v->u.rail.flags, VRF_REVERSE_DIRECTION);
01928       InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
01929       InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
01930     }
01931   } else {
01932     /* turn the whole train around */
01933     if (v->vehstatus & VS_CRASHED || v->breakdown_ctr != 0) return CMD_ERROR;
01934 
01935     if (flags & DC_EXEC) {
01936       /* Properly leave the station if we are loading and won't be loading anymore */
01937       if (v->current_order.IsType(OT_LOADING)) {
01938         const Vehicle *last = v;
01939         while (last->Next() != NULL) last = last->Next();
01940 
01941         /* not a station || different station --> leave the station */
01942         if (!IsTileType(last->tile, MP_STATION) || GetStationIndex(last->tile) != GetStationIndex(v->tile)) {
01943           v->LeaveStation();
01944         }
01945       }
01946 
01947       if (_settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL && v->cur_speed != 0) {
01948         ToggleBit(v->u.rail.flags, VRF_REVERSING);
01949       } else {
01950         v->cur_speed = 0;
01951         SetLastSpeed(v, 0);
01952         HideFillingPercent(&v->fill_percent_te_id);
01953         ReverseTrainDirection(v);
01954       }
01955     }
01956   }
01957   return CommandCost();
01958 }
01959 
01966 CommandCost CmdForceTrainProceed(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01967 {
01968   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01969 
01970   Vehicle *v = GetVehicle(p1);
01971 
01972   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
01973 
01974   if (flags & DC_EXEC) v->u.rail.force_proceed = 0x50;
01975 
01976   return CommandCost();
01977 }
01978 
01989 CommandCost CmdRefitRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
01990 {
01991   CargoID new_cid = GB(p2, 0, 8);
01992   byte new_subtype = GB(p2, 8, 8);
01993   bool only_this = HasBit(p2, 16);
01994 
01995   if (!IsValidVehicleID(p1)) return CMD_ERROR;
01996 
01997   Vehicle *v = GetVehicle(p1);
01998 
01999   if (v->type != VEH_TRAIN || !CheckOwnership(v->owner)) return CMD_ERROR;
02000   if (CheckTrainStoppedInDepot(v) < 0) return_cmd_error(STR_TRAIN_MUST_BE_STOPPED);
02001   if (v->vehstatus & VS_CRASHED) return_cmd_error(STR_CAN_T_REFIT_DESTROYED_VEHICLE);
02002 
02003   /* Check cargo */
02004   if (new_cid >= NUM_CARGO) return CMD_ERROR;
02005 
02006   CommandCost cost(EXPENSES_TRAIN_RUN);
02007   uint num = 0;
02008 
02009   do {
02010     /* XXX: We also refit all the attached wagons en-masse if they
02011      * can be refitted. This is how TTDPatch does it.  TODO: Have
02012      * some nice [Refit] button near each wagon. --pasky */
02013     if (!CanRefitTo(v->engine_type, new_cid)) continue;
02014 
02015     const Engine *e = GetEngine(v->engine_type);
02016     if (e->CanCarryCargo()) {
02017       uint16 amount = CALLBACK_FAILED;
02018 
02019       if (HasBit(EngInfo(v->engine_type)->callbackmask, CBM_VEHICLE_REFIT_CAPACITY)) {
02020         /* Back up the vehicle's cargo type */
02021         CargoID temp_cid = v->cargo_type;
02022         byte temp_subtype = v->cargo_subtype;
02023         v->cargo_type = new_cid;
02024         v->cargo_subtype = new_subtype;
02025         /* Check the refit capacity callback */
02026         amount = GetVehicleCallback(CBID_VEHICLE_REFIT_CAPACITY, 0, 0, v->engine_type, v);
02027         /* Restore the original cargo type */
02028         v->cargo_type = temp_cid;
02029         v->cargo_subtype = temp_subtype;
02030       }
02031 
02032       if (amount == CALLBACK_FAILED) { // callback failed or not used, use default
02033         CargoID old_cid = e->GetDefaultCargoType();
02034         /* normally, the capacity depends on the cargo type, a rail vehicle can
02035          * carry twice as much mail/goods as normal cargo, and four times as
02036          * many passengers
02037          */
02038         amount = e->u.rail.capacity;
02039         switch (old_cid) {
02040           case CT_PASSENGERS: break;
02041           case CT_MAIL:
02042           case CT_GOODS: amount *= 2; break;
02043           default:       amount *= 4; break;
02044         }
02045         switch (new_cid) {
02046           case CT_PASSENGERS: break;
02047           case CT_MAIL:
02048           case CT_GOODS: amount /= 2; break;
02049           default:       amount /= 4; break;
02050         }
02051       }
02052 
02053       if (new_cid != v->cargo_type) {
02054         cost.AddCost(GetRefitCost(v->engine_type));
02055       }
02056 
02057       num += amount;
02058       if (flags & DC_EXEC) {
02059         v->cargo.Truncate((v->cargo_type == new_cid) ? amount : 0);
02060         v->cargo_type = new_cid;
02061         v->cargo_cap = amount;
02062         v->cargo_subtype = new_subtype;
02063         InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
02064         InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
02065         InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
02066       }
02067     }
02068   } while ((v = v->Next()) != NULL && !only_this);
02069 
02070   _returned_refit_capacity = num;
02071 
02072   /* Update the train's cached variables */
02073   if (flags & DC_EXEC) TrainConsistChanged(GetVehicle(p1)->First(), false);
02074 
02075   return cost;
02076 }
02077 
02078 struct TrainFindDepotData {
02079   uint best_length;
02080   TileIndex tile;
02081   Owner owner;
02086   bool reverse;
02087 };
02088 
02089 static bool NtpCallbFindDepot(TileIndex tile, TrainFindDepotData *tfdd, int track, uint length)
02090 {
02091   if (IsTileType(tile, MP_RAILWAY) &&
02092       IsTileOwner(tile, tfdd->owner) &&
02093       IsRailDepot(tile)) {
02094     /* approximate number of tiles by dividing by DIAG_FACTOR */
02095     tfdd->best_length = length / DIAG_FACTOR;
02096     tfdd->tile = tile;
02097     return true;
02098   }
02099 
02100   return false;
02101 }
02102 
02105 static TrainFindDepotData FindClosestTrainDepot(Vehicle *v, int max_distance)
02106 {
02107   assert(!(v->vehstatus & VS_CRASHED));
02108 
02109   TrainFindDepotData tfdd;
02110   tfdd.owner = v->owner;
02111   tfdd.reverse = false;
02112 
02113   if (IsRailDepotTile(v->tile)) {
02114     tfdd.tile = v->tile;
02115     tfdd.best_length = 0;
02116     return tfdd;
02117   }
02118 
02119   PBSTileInfo origin = FollowTrainReservation(v);
02120   if (IsRailDepotTile(origin.tile)) {
02121     tfdd.tile = origin.tile;
02122     tfdd.best_length = 0;
02123     return tfdd;
02124   }
02125 
02126   tfdd.best_length = UINT_MAX;
02127 
02128   uint8 pathfinder = _settings_game.pf.pathfinder_for_trains;
02129   if ((_settings_game.pf.reserve_paths || HasReservedTracks(v->tile, v->u.rail.track)) && pathfinder == VPF_NTP) pathfinder = VPF_NPF;
02130 
02131   switch (pathfinder) {
02132     case VPF_YAPF: { // YAPF
02133       bool found = YapfFindNearestRailDepotTwoWay(v, max_distance, NPF_INFINITE_PENALTY, &tfdd.tile, &tfdd.reverse);
02134       tfdd.best_length = found ? max_distance / 2 : UINT_MAX; // some fake distance or NOT_FOUND
02135     } break;
02136 
02137     case VPF_NPF: { // NPF
02138       const Vehicle *last = GetLastVehicleInChain(v);
02139       Trackdir trackdir = GetVehicleTrackdir(v);
02140       Trackdir trackdir_rev = ReverseTrackdir(GetVehicleTrackdir(last));
02141 
02142       assert(trackdir != INVALID_TRACKDIR);
02143       NPFFoundTargetData ftd = NPFRouteToDepotBreadthFirstTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes, NPF_INFINITE_PENALTY);
02144       if (ftd.best_bird_dist == 0) {
02145         /* Found target */
02146         tfdd.tile = ftd.node.tile;
02147         /* Our caller expects a number of tiles, so we just approximate that
02148          * number by this. It might not be completely what we want, but it will
02149          * work for now :-) We can possibly change this when the old pathfinder
02150          * is removed. */
02151         tfdd.best_length = ftd.best_path_dist / NPF_TILE_LENGTH;
02152         if (NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE)) tfdd.reverse = true;
02153       }
02154     } break;
02155 
02156     default:
02157     case VPF_NTP: { // NTP
02158       /* search in the forward direction first. */
02159       DiagDirection i = TrainExitDir(v->direction, v->u.rail.track);
02160       NewTrainPathfind(v->tile, 0, v->u.rail.compatible_railtypes, i, (NTPEnumProc*)NtpCallbFindDepot, &tfdd);
02161       if (tfdd.best_length == UINT_MAX){
02162         tfdd.reverse = true;
02163         /* search in backwards direction */
02164         i = TrainExitDir(ReverseDir(v->direction), v->u.rail.track);
02165         NewTrainPathfind(v->tile, 0, v->u.rail.compatible_railtypes, i, (NTPEnumProc*)NtpCallbFindDepot, &tfdd);
02166       }
02167     } break;
02168   }
02169 
02170   return tfdd;
02171 }
02172 
02173 bool Train::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
02174 {
02175   TrainFindDepotData tfdd = FindClosestTrainDepot(this, 0);
02176   if (tfdd.best_length == UINT_MAX) return false;
02177 
02178   if (location    != NULL) *location    = tfdd.tile;
02179   if (destination != NULL) *destination = GetDepotByTile(tfdd.tile)->index;
02180   if (reverse     != NULL) *reverse     = tfdd.reverse;
02181 
02182   return true;
02183 }
02184 
02193 CommandCost CmdSendTrainToDepot(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
02194 {
02195   if (p2 & DEPOT_MASS_SEND) {
02196     /* Mass goto depot requested */
02197     if (!ValidVLWFlags(p2 & VLW_MASK)) return CMD_ERROR;
02198     return SendAllVehiclesToDepot(VEH_TRAIN, flags, p2 & DEPOT_SERVICE, _current_company, (p2 & VLW_MASK), p1);
02199   }
02200 
02201   if (!IsValidVehicleID(p1)) return CMD_ERROR;
02202 
02203   Vehicle *v = GetVehicle(p1);
02204 
02205   if (v->type != VEH_TRAIN) return CMD_ERROR;
02206 
02207   return v->SendToDepot(flags, (DepotCommand)(p2 & DEPOT_COMMAND_MASK));
02208 }
02209 
02210 
02211 void OnTick_Train()
02212 {
02213   _age_cargo_skip_counter = (_age_cargo_skip_counter == 0) ? 184 : (_age_cargo_skip_counter - 1);
02214 }
02215 
02216 static const int8 _vehicle_smoke_pos[8] = {
02217   1, 1, 1, 0, -1, -1, -1, 0
02218 };
02219 
02220 static void HandleLocomotiveSmokeCloud(const Vehicle *v)
02221 {
02222   bool sound = false;
02223 
02224   if (v->vehstatus & VS_TRAIN_SLOWING || v->load_unload_time_rem != 0 || v->cur_speed < 2) {
02225     return;
02226   }
02227 
02228   const Vehicle *u = v;
02229 
02230   do {
02231     const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
02232     int effect_offset = GB(v->u.rail.cached_vis_effect, 0, 4) - 8;
02233     byte effect_type = GB(v->u.rail.cached_vis_effect, 4, 2);
02234     bool disable_effect = HasBit(v->u.rail.cached_vis_effect, 6);
02235 
02236     /* no smoke? */
02237     if ((rvi->railveh_type == RAILVEH_WAGON && effect_type == 0) ||
02238         disable_effect ||
02239         v->vehstatus & VS_HIDDEN) {
02240       continue;
02241     }
02242 
02243     /* No smoke in depots or tunnels */
02244     if (IsRailDepotTile(v->tile) || IsTunnelTile(v->tile)) continue;
02245 
02246     /* No sparks for electric vehicles on nonelectrified tracks */
02247     if (!HasPowerOnRail(v->u.rail.railtype, GetTileRailType(v->tile))) continue;
02248 
02249     if (effect_type == 0) {
02250       /* Use default effect type for engine class. */
02251       effect_type = rvi->engclass;
02252     } else {
02253       effect_type--;
02254     }
02255 
02256     int x = _vehicle_smoke_pos[v->direction] * effect_offset;
02257     int y = _vehicle_smoke_pos[(v->direction + 2) % 8] * effect_offset;
02258 
02259     if (HasBit(v->u.rail.flags, VRF_REVERSE_DIRECTION)) {
02260       x = -x;
02261       y = -y;
02262     }
02263 
02264     switch (effect_type) {
02265       case 0:
02266         /* steam smoke. */
02267         if (GB(v->tick_counter, 0, 4) == 0) {
02268           CreateEffectVehicleRel(v, x, y, 10, EV_STEAM_SMOKE);
02269           sound = true;
02270         }
02271         break;
02272 
02273       case 1:
02274         /* diesel smoke */
02275         if (u->cur_speed <= 40 && Chance16(15, 128)) {
02276           CreateEffectVehicleRel(v, 0, 0, 10, EV_DIESEL_SMOKE);
02277           sound = true;
02278         }
02279         break;
02280 
02281       case 2:
02282         /* blue spark */
02283         if (GB(v->tick_counter, 0, 2) == 0 && Chance16(1, 45)) {
02284           CreateEffectVehicleRel(v, 0, 0, 10, EV_ELECTRIC_SPARK);
02285           sound = true;
02286         }
02287         break;
02288 
02289       default:
02290         break;
02291     }
02292   } while ((v = v->Next()) != NULL);
02293 
02294   if (sound) PlayVehicleSound(u, VSE_TRAIN_EFFECT);
02295 }
02296 
02297 void Train::PlayLeaveStationSound() const
02298 {
02299   static const SoundFx sfx[] = {
02300     SND_04_TRAIN,
02301     SND_0A_TRAIN_HORN,
02302     SND_0A_TRAIN_HORN,
02303     SND_47_MAGLEV_2,
02304     SND_41_MAGLEV
02305   };
02306 
02307   if (PlayVehicleSound(this, VSE_START)) return;
02308 
02309   EngineID engtype = this->engine_type;
02310   SndPlayVehicleFx(sfx[RailVehInfo(engtype)->engclass], this);
02311 }
02312 
02314 static void CheckNextTrainTile(Vehicle *v)
02315 {
02316   /* Don't do any look-ahead if path_backoff_interval is 255. */
02317   if (_settings_game.pf.path_backoff_interval == 255) return;
02318 
02319   /* Exit if we reached our destination depot or are inside a depot. */
02320   if ((v->tile == v->dest_tile && v->current_order.IsType(OT_GOTO_DEPOT)) || v->u.rail.track & TRACK_BIT_DEPOT) return;
02321   /* Exit if we are on a station tile and are going to stop. */
02322   if (IsRailwayStationTile(v->tile) && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile))) return;
02323   /* Exit if the current order doesn't have a destination, but the train has orders. */
02324   if ((v->current_order.IsType(OT_NOTHING) || v->current_order.IsType(OT_LEAVESTATION) || v->current_order.IsType(OT_LOADING)) && v->GetNumOrders() > 0) return;
02325 
02326   Trackdir td = GetVehicleTrackdir(v);
02327 
02328   /* On a tile with a red non-pbs signal, don't look ahead. */
02329   if (IsTileType(v->tile, MP_RAILWAY) && HasSignalOnTrackdir(v->tile, td) &&
02330       !IsPbsSignal(GetSignalType(v->tile, TrackdirToTrack(td))) &&
02331       GetSignalStateByTrackdir(v->tile, td) == SIGNAL_STATE_RED) return;
02332 
02333   CFollowTrackRail ft(v);
02334   if (!ft.Follow(v->tile, td)) return;
02335 
02336   if (!HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) {
02337     /* Next tile is not reserved. */
02338     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02339       if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
02340         /* If the next tile is a PBS signal, try to make a reservation. */
02341         TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02342         if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
02343           tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
02344         }
02345         ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, NULL, false);
02346       }
02347     }
02348   }
02349 }
02350 
02351 static bool CheckTrainStayInDepot(Vehicle *v)
02352 {
02353   /* bail out if not all wagons are in the same depot or not in a depot at all */
02354   for (const Vehicle *u = v; u != NULL; u = u->Next()) {
02355     if (u->u.rail.track != TRACK_BIT_DEPOT || u->tile != v->tile) return false;
02356   }
02357 
02358   /* if the train got no power, then keep it in the depot */
02359   if (v->u.rail.cached_power == 0) {
02360     v->vehstatus |= VS_STOPPED;
02361     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
02362     return true;
02363   }
02364 
02365   SigSegState seg_state;
02366 
02367   if (v->u.rail.force_proceed == 0) {
02368     /* force proceed was not pressed */
02369     if (++v->load_unload_time_rem < 37) {
02370       InvalidateWindowClasses(WC_TRAINS_LIST);
02371       return true;
02372     }
02373 
02374     v->load_unload_time_rem = 0;
02375 
02376     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02377     if (seg_state == SIGSEG_FULL || GetDepotWaypointReservation(v->tile)) {
02378       /* Full and no PBS signal in block or depot reserved, can't exit. */
02379       InvalidateWindowClasses(WC_TRAINS_LIST);
02380       return true;
02381     }
02382   } else {
02383     seg_state = _settings_game.pf.reserve_paths ? SIGSEG_PBS : UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02384   }
02385 
02386   /* Only leave when we can reserve a path to our destination. */
02387   if (seg_state == SIGSEG_PBS && !TryPathReserve(v) && v->u.rail.force_proceed == 0) {
02388     /* No path and no force proceed. */
02389     InvalidateWindowClasses(WC_TRAINS_LIST);
02390     MarkTrainAsStuck(v);
02391     return true;
02392   }
02393 
02394   SetDepotWaypointReservation(v->tile, true);
02395   if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
02396 
02397   VehicleServiceInDepot(v);
02398   InvalidateWindowClasses(WC_TRAINS_LIST);
02399   v->PlayLeaveStationSound();
02400 
02401   v->u.rail.track = TRACK_BIT_X;
02402   if (v->direction & 2) v->u.rail.track = TRACK_BIT_Y;
02403 
02404   v->vehstatus &= ~VS_HIDDEN;
02405   v->cur_speed = 0;
02406 
02407   v->UpdateDeltaXY(v->direction);
02408   v->cur_image = v->GetImage(v->direction);
02409   VehicleMove(v, false);
02410   UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
02411   UpdateTrainAcceleration(v);
02412   InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
02413 
02414   return false;
02415 }
02416 
02418 static void ClearPathReservation(const Vehicle *v, TileIndex tile, Trackdir track_dir)
02419 {
02420   DiagDirection dir = TrackdirToExitdir(track_dir);
02421 
02422   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
02423     /* Are we just leaving a tunnel/bridge? */
02424     if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
02425       TileIndex end = GetOtherTunnelBridgeEnd(tile);
02426 
02427       if (!HasVehicleOnTunnelBridge(tile, end, v)) {
02428         /* Free the reservation only if no other train is on the tiles. */
02429         SetTunnelBridgeReservation(tile, false);
02430         SetTunnelBridgeReservation(end, false);
02431 
02432         if (_settings_client.gui.show_track_reservation) {
02433           MarkTileDirtyByTile(tile);
02434           MarkTileDirtyByTile(end);
02435         }
02436       }
02437     }
02438   } else if (IsRailwayStationTile(tile)) {
02439     TileIndex new_tile = TileAddByDiagDir(tile, dir);
02440     /* If the new tile is not a further tile of the same station, we
02441      * clear the reservation for the whole platform. */
02442     if (!IsCompatibleTrainStationTile(new_tile, tile)) {
02443       SetRailwayStationPlatformReservation(tile, ReverseDiagDir(dir), false);
02444     }
02445   } else {
02446     /* Any other tile */
02447     UnreserveRailTrack(tile, TrackdirToTrack(track_dir));
02448   }
02449 }
02450 
02452 void FreeTrainTrackReservation(const Vehicle *v, TileIndex origin, Trackdir orig_td)
02453 {
02454   assert(IsFrontEngine(v));
02455 
02456   TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
02457   Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : GetVehicleTrackdir(v);
02458   bool      free_tile = tile != v->tile || !(IsRailwayStationTile(v->tile) || IsTileType(v->tile, MP_TUNNELBRIDGE));
02459   StationID station_id = IsRailwayStationTile(v->tile) ? GetStationIndex(v->tile) : INVALID_STATION;
02460 
02461   /* Don't free reservation if it's not ours. */
02462   if (TracksOverlap(GetReservedTrackbits(tile) | TrackToTrackBits(TrackdirToTrack(td)))) return;
02463 
02464   CFollowTrackRail ft(v, GetRailTypeInfo(v->u.rail.railtype)->compatible_railtypes);
02465   while (ft.Follow(tile, td)) {
02466     tile = ft.m_new_tile;
02467     TrackdirBits bits = ft.m_new_td_bits & TrackBitsToTrackdirBits(GetReservedTrackbits(tile));
02468     td = RemoveFirstTrackdir(&bits);
02469     assert(bits == TRACKDIR_BIT_NONE);
02470 
02471     if (!IsValidTrackdir(td)) break;
02472 
02473     if (IsTileType(tile, MP_RAILWAY)) {
02474       if (HasSignalOnTrackdir(tile, td) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)))) {
02475         /* Conventional signal along trackdir: remove reservation and stop. */
02476         UnreserveRailTrack(tile, TrackdirToTrack(td));
02477         break;
02478       }
02479       if (HasPbsSignalOnTrackdir(tile, td)) {
02480         if (GetSignalStateByTrackdir(tile, td) == SIGNAL_STATE_RED) {
02481           /* Red PBS signal? Can't be our reservation, would be green then. */
02482           break;
02483         } else {
02484           /* Turn the signal back to red. */
02485           SetSignalStateByTrackdir(tile, td, SIGNAL_STATE_RED);
02486           MarkTileDirtyByTile(tile);
02487         }
02488       } else if (HasSignalOnTrackdir(tile, ReverseTrackdir(td)) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
02489         break;
02490       }
02491     }
02492 
02493     /* Don't free first station/bridge/tunnel if we are on it. */
02494     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);
02495 
02496     free_tile = true;
02497   }
02498 }
02499 
02501 struct TrainTrackFollowerData {
02502   TileIndex dest_coords;
02503   StationID station_index; 
02504   uint best_bird_dist;
02505   uint best_track_dist;
02506   TrackdirByte best_track;
02507 };
02508 
02509 static bool NtpCallbFindStation(TileIndex tile, TrainTrackFollowerData *ttfd, Trackdir track, uint length)
02510 {
02511   /* heading for nowhere? */
02512   if (ttfd->dest_coords == 0) return false;
02513 
02514   /* did we reach the final station? */
02515   if ((ttfd->station_index == INVALID_STATION && tile == ttfd->dest_coords) || (
02516         IsTileType(tile, MP_STATION) &&
02517         IsRailwayStation(tile) &&
02518         GetStationIndex(tile) == ttfd->station_index
02519       )) {
02520     /* We do not check for dest_coords if we have a station_index,
02521      * because in that case the dest_coords are just an
02522      * approximation of where the station is */
02523 
02524     /* found station */
02525     ttfd->best_track = track;
02526     ttfd->best_bird_dist = 0;
02527     return true;
02528   } else {
02529     /* didn't find station, keep track of the best path so far. */
02530     uint dist = DistanceManhattan(tile, ttfd->dest_coords);
02531     if (dist < ttfd->best_bird_dist) {
02532       ttfd->best_bird_dist = dist;
02533       ttfd->best_track = track;
02534     }
02535     return false;
02536   }
02537 }
02538 
02539 static void FillWithStationData(TrainTrackFollowerData *fd, const Vehicle *v)
02540 {
02541   fd->dest_coords = v->dest_tile;
02542   fd->station_index = v->current_order.IsType(OT_GOTO_STATION) ? v->current_order.GetDestination() : INVALID_STATION;
02543 }
02544 
02545 static const byte _initial_tile_subcoord[6][4][3] = {
02546 {{ 15, 8, 1 }, { 0, 0, 0 }, { 0, 8, 5 }, { 0,  0, 0 }},
02547 {{  0, 0, 0 }, { 8, 0, 3 }, { 0, 0, 0 }, { 8, 15, 7 }},
02548 {{  0, 0, 0 }, { 7, 0, 2 }, { 0, 7, 6 }, { 0,  0, 0 }},
02549 {{ 15, 8, 2 }, { 0, 0, 0 }, { 0, 0, 0 }, { 8, 15, 6 }},
02550 {{ 15, 7, 0 }, { 8, 0, 4 }, { 0, 0, 0 }, { 0,  0, 0 }},
02551 {{  0, 0, 0 }, { 0, 0, 0 }, { 0, 8, 4 }, { 7, 15, 0 }},
02552 };
02553 
02554 static const byte _search_directions[6][4] = {
02555   { 0, 9, 2, 9 }, 
02556   { 9, 1, 9, 3 }, 
02557   { 9, 0, 3, 9 }, 
02558   { 1, 9, 9, 2 }, 
02559   { 3, 2, 9, 9 }, 
02560   { 9, 9, 1, 0 }, 
02561 };
02562 
02563 static const byte _pick_track_table[6] = {1, 3, 2, 2, 0, 0};
02564 
02577 static Track DoTrainPathfind(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool do_track_reservation, PBSTileInfo *dest)
02578 {
02579   Track best_track;
02580 
02581 #ifdef PF_BENCHMARK
02582   TIC()
02583 #endif
02584 
02585   if (path_not_found) *path_not_found = false;
02586 
02587   uint8 pathfinder = _settings_game.pf.pathfinder_for_trains;
02588   if (do_track_reservation && pathfinder == VPF_NTP) pathfinder = VPF_NPF;
02589 
02590   switch (pathfinder) {
02591     case VPF_YAPF: { // YAPF
02592       Trackdir trackdir = YapfChooseRailTrack(v, tile, enterdir, tracks, path_not_found, do_track_reservation, dest);
02593       if (trackdir != INVALID_TRACKDIR) {
02594         best_track = TrackdirToTrack(trackdir);
02595       } else {
02596         best_track = FindFirstTrack(tracks);
02597       }
02598     } break;
02599 
02600     case VPF_NPF: { // NPF
02601       void *perf = NpfBeginInterval();
02602 
02603       NPFFindStationOrTileData fstd;
02604       NPFFillWithOrderData(&fstd, v, do_track_reservation);
02605 
02606       PBSTileInfo origin = FollowTrainReservation(v);
02607       assert(IsValidTrackdir(origin.trackdir));
02608 
02609       NPFFoundTargetData ftd = NPFRouteToStationOrTile(origin.tile, origin.trackdir, true, &fstd, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes);
02610 
02611       if (dest != NULL) {
02612         dest->tile = ftd.node.tile;
02613         dest->trackdir = (Trackdir)ftd.node.direction;
02614         dest->okay = ftd.res_okay;
02615       }
02616 
02617       if (ftd.best_trackdir == INVALID_TRACKDIR) {
02618         /* We are already at our target. Just do something
02619          * @todo maybe display error?
02620          * @todo: go straight ahead if possible? */
02621         best_track = FindFirstTrack(tracks);
02622       } else {
02623         /* If ftd.best_bird_dist is 0, we found our target and ftd.best_trackdir contains
02624          * the direction we need to take to get there, if ftd.best_bird_dist is not 0,
02625          * we did not find our target, but ftd.best_trackdir contains the direction leading
02626          * to the tile closest to our target. */
02627         if (ftd.best_bird_dist != 0 && path_not_found != NULL) *path_not_found = true;
02628         /* Discard enterdir information, making it a normal track */
02629         best_track = TrackdirToTrack(ftd.best_trackdir);
02630       }
02631 
02632       int time = NpfEndInterval(perf);
02633       DEBUG(yapf, 4, "[NPFT] %d us - %d rounds - %d open - %d closed -- ", time, 0, _aystar_stats_open_size, _aystar_stats_closed_size);
02634     } break;
02635 
02636     default:
02637     case VPF_NTP: { // NTP
02638       void *perf = NpfBeginInterval();
02639 
02640       TrainTrackFollowerData fd;
02641       FillWithStationData(&fd, v);
02642 
02643       /* New train pathfinding */
02644       fd.best_bird_dist = UINT_MAX;
02645       fd.best_track_dist = UINT_MAX;
02646       fd.best_track = INVALID_TRACKDIR;
02647 
02648       NewTrainPathfind(tile - TileOffsByDiagDir(enterdir), v->dest_tile,
02649         v->u.rail.compatible_railtypes, enterdir, (NTPEnumProc*)NtpCallbFindStation, &fd);
02650 
02651       /* check whether the path was found or only 'guessed' */
02652       if (fd.best_bird_dist != 0 && path_not_found != NULL) *path_not_found = true;
02653 
02654       if (fd.best_track == INVALID_TRACKDIR) {
02655         /* blaha */
02656         best_track = FindFirstTrack(tracks);
02657       } else {
02658         best_track = TrackdirToTrack(fd.best_track);
02659       }
02660 
02661       int time = NpfEndInterval(perf);
02662       DEBUG(yapf, 4, "[NTPT] %d us - %d rounds - %d open - %d closed -- ", time, 0, 0, 0);
02663     } break;
02664   }
02665 
02666 #ifdef PF_BENCHMARK
02667   TOC("PF time = ", 1)
02668 #endif
02669 
02670   return best_track;
02671 }
02672 
02678 static PBSTileInfo ExtendTrainReservation(const Vehicle *v, TrackBits *new_tracks, DiagDirection *enterdir)
02679 {
02680   bool no_90deg_turns = _settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg;
02681   PBSTileInfo origin = FollowTrainReservation(v);
02682 
02683   CFollowTrackRail ft(v);
02684 
02685   TileIndex tile = origin.tile;
02686   Trackdir  cur_td = origin.trackdir;
02687   while (ft.Follow(tile, cur_td)) {
02688     if (KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
02689       /* Possible signal tile. */
02690       if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
02691     }
02692 
02693     if (no_90deg_turns) {
02694       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02695       if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
02696     }
02697 
02698     /* Station, depot or waypoint are a possible target. */
02699     bool target_seen = ft.m_is_station || (IsTileType(ft.m_new_tile, MP_RAILWAY) && !IsPlainRailTile(ft.m_new_tile));
02700     if (target_seen || KillFirstBit(ft.m_new_td_bits) != TRACKDIR_BIT_NONE) {
02701       /* Choice found or possible target encountered.
02702        * On finding a possible target, we need to stop and let the pathfinder handle the
02703        * remaining path. This is because we don't know if this target is in one of our
02704        * orders, so we might cause pathfinding to fail later on if we find a choice.
02705        * This failure would cause a bogous call to TryReserveSafePath which might reserve
02706        * a wrong path not leading to our next destination. */
02707       if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(TrackdirReachesTrackdirs(ft.m_old_td)))) break;
02708 
02709       /* If we did skip some tiles, backtrack to the first skipped tile so the pathfinder
02710        * actually starts its search at the first unreserved tile. */
02711       if (ft.m_tiles_skipped != 0) ft.m_new_tile -= TileOffsByDiagDir(ft.m_exitdir) * ft.m_tiles_skipped;
02712 
02713       /* Choice found, path valid but not okay. Save info about the choice tile as well. */
02714       if (new_tracks) *new_tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
02715       if (enterdir) *enterdir = ft.m_exitdir;
02716       return PBSTileInfo(ft.m_new_tile, ft.m_old_td, false);
02717     }
02718 
02719     tile = ft.m_new_tile;
02720     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02721 
02722     if (IsSafeWaitingPosition(v, tile, cur_td, true, no_90deg_turns)) {
02723       bool wp_free = IsWaitingPositionFree(v, tile, cur_td, no_90deg_turns);
02724       if (!(wp_free && TryReserveRailTrack(tile, TrackdirToTrack(cur_td)))) break;
02725       /* Safe position is all good, path valid and okay. */
02726       return PBSTileInfo(tile, cur_td, true);
02727     }
02728 
02729     if (!TryReserveRailTrack(tile, TrackdirToTrack(cur_td))) break;
02730   }
02731 
02732   if (ft.m_err == CFollowTrackRail::EC_OWNER || ft.m_err == CFollowTrackRail::EC_NO_WAY) {
02733     /* End of line, path valid and okay. */
02734     return PBSTileInfo(ft.m_old_tile, ft.m_old_td, true);
02735   }
02736 
02737   /* Sorry, can't reserve path, back out. */
02738   tile = origin.tile;
02739   cur_td = origin.trackdir;
02740   TileIndex stopped = ft.m_old_tile;
02741   Trackdir  stopped_td = ft.m_old_td;
02742   while (tile != stopped || cur_td != stopped_td) {
02743     if (!ft.Follow(tile, cur_td)) break;
02744 
02745     if (no_90deg_turns) {
02746       ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
02747       assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
02748     }
02749     assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
02750 
02751     tile = ft.m_new_tile;
02752     cur_td = FindFirstTrackdir(ft.m_new_td_bits);
02753 
02754     UnreserveRailTrack(tile, TrackdirToTrack(cur_td));
02755   }
02756 
02757   /* Path invalid. */
02758   return PBSTileInfo();
02759 }
02760 
02771 static bool TryReserveSafeTrack(const Vehicle *v, TileIndex tile, Trackdir td, bool override_tailtype)
02772 {
02773   if (_settings_game.pf.pathfinder_for_trains == VPF_YAPF) {
02774     return YapfRailFindNearestSafeTile(v, tile, td, override_tailtype);
02775   } else {
02776     return NPFRouteToSafeTile(v, tile, td, override_tailtype).res_okay;
02777   }
02778 }
02779 
02781 class VehicleOrderSaver
02782 {
02783 private:
02784   Vehicle        *v;
02785   Order          old_order;
02786   TileIndex      old_dest_tile;
02787   StationID      old_last_station_visited;
02788   VehicleOrderID index;
02789 
02790 public:
02791   VehicleOrderSaver(Vehicle *_v) :
02792     v(_v),
02793     old_order(_v->current_order),
02794     old_dest_tile(_v->dest_tile),
02795     old_last_station_visited(_v->last_station_visited),
02796     index(_v->cur_order_index)
02797   {
02798   }
02799 
02800   ~VehicleOrderSaver()
02801   {
02802     this->v->current_order = this->old_order;
02803     this->v->dest_tile = this->old_dest_tile;
02804     this->v->last_station_visited = this->old_last_station_visited;
02805   }
02806 
02812   bool SwitchToNextOrder(bool skip_first)
02813   {
02814     if (this->v->GetNumOrders() == 0) return false;
02815 
02816     if (skip_first) ++this->index;
02817 
02818     int conditional_depth = 0;
02819 
02820     do {
02821       /* Wrap around. */
02822       if (this->index >= this->v->GetNumOrders()) this->index = 0;
02823 
02824       Order *order = GetVehicleOrder(this->v, this->index);
02825       assert(order != NULL);
02826 
02827       switch (order->GetType()) {
02828         case OT_GOTO_DEPOT:
02829           /* Skip service in depot orders when the train doesn't need service. */
02830           if ((order->GetDepotOrderType() & ODTFB_SERVICE) && !this->v->NeedsServicing()) break;
02831         case OT_GOTO_STATION:
02832         case OT_GOTO_WAYPOINT:
02833           this->v->current_order = *order;
02834           UpdateOrderDest(this->v, order);
02835           return true;
02836         case OT_CONDITIONAL: {
02837           if (conditional_depth > this->v->GetNumOrders()) return false;
02838           VehicleOrderID next = ProcessConditionalOrder(order, this->v);
02839           if (next != INVALID_VEH_ORDER_ID) {
02840             conditional_depth++;
02841             this->index = next;
02842             /* Don't increment next, so no break here. */
02843             continue;
02844           }
02845           break;
02846         }
02847         default:
02848           break;
02849       }
02850       /* Don't increment inside the while because otherwise conditional
02851        * orders can lead to an infinite loop. */
02852       ++this->index;
02853     } while (this->index != this->v->cur_order_index);
02854 
02855     return false;
02856   }
02857 };
02858 
02859 /* choose a track */
02860 static Track ChooseTrainTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool force_res, bool *got_reservation, bool mark_stuck)
02861 {
02862   Track best_track = INVALID_TRACK;
02863   bool do_track_reservation = _settings_game.pf.reserve_paths || force_res;
02864   bool changed_signal = false;
02865 
02866   assert((tracks & ~TRACK_BIT_MASK) == 0);
02867 
02868   if (got_reservation != NULL) *got_reservation = false;
02869 
02870   /* Don't use tracks here as the setting to forbid 90 deg turns might have been switched between reservation and now. */
02871   TrackBits res_tracks = (TrackBits)(GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir));
02872   /* Do we have a suitable reserved track? */
02873   if (res_tracks != TRACK_BIT_NONE) return FindFirstTrack(res_tracks);
02874 
02875   /* Quick return in case only one possible track is available */
02876   if (KillFirstBit(tracks) == TRACK_BIT_NONE) {
02877     Track track = FindFirstTrack(tracks);
02878     /* We need to check for signals only here, as a junction tile can't have signals. */
02879     if (track != INVALID_TRACK && HasPbsSignalOnTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir))) {
02880       do_track_reservation = true;
02881       changed_signal = true;
02882       SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(track, enterdir), SIGNAL_STATE_GREEN);
02883     } else if (!do_track_reservation) {
02884       return track;
02885     }
02886     best_track = track;
02887   }
02888 
02889   PBSTileInfo   res_dest(tile, INVALID_TRACKDIR, false);
02890   DiagDirection dest_enterdir = enterdir;
02891   if (do_track_reservation) {
02892     /* Check if the train needs service here, so it has a chance to always find a depot.
02893      * Also check if the current order is a service order so we don't reserve a path to
02894      * the destination but instead to the next one if service isn't needed. */
02895     CheckIfTrainNeedsService(v);
02896     if (v->current_order.IsType(OT_DUMMY) || v->current_order.IsType(OT_CONDITIONAL) || v->current_order.IsType(OT_GOTO_DEPOT)) ProcessOrders(v);
02897 
02898     res_dest = ExtendTrainReservation(v, &tracks, &dest_enterdir);
02899     if (res_dest.tile == INVALID_TILE) {
02900       /* Reservation failed? */
02901       if (mark_stuck) MarkTrainAsStuck(v);
02902       if (changed_signal) SetSignalStateByTrackdir(tile, TrackEnterdirToTrackdir(best_track, enterdir), SIGNAL_STATE_RED);
02903       return FindFirstTrack(tracks);
02904     }
02905   }
02906 
02907   /* Save the current train order. The destructor will restore the old order on function exit. */
02908   VehicleOrderSaver orders(v);
02909 
02910   /* If the current tile is the destination of the current order and
02911    * a reservation was requested, advance to the next order.
02912    * Don't advance on a depot order as depots are always safe end points
02913    * for a path and no look-ahead is necessary. This also avoids a
02914    * problem with depot orders not part of the order list when the
02915    * order list itself is empty. */
02916   if (v->current_order.IsType(OT_LEAVESTATION)) {
02917     orders.SwitchToNextOrder(false);
02918   } else if (v->current_order.IsType(OT_LOADING) || (!v->current_order.IsType(OT_GOTO_DEPOT) && (
02919       v->current_order.IsType(OT_GOTO_STATION) ?
02920       IsRailwayStationTile(v->tile) && v->current_order.GetDestination() == GetStationIndex(v->tile) :
02921       v->tile == v->dest_tile))) {
02922     orders.SwitchToNextOrder(true);
02923   }
02924 
02925   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02926     /* Pathfinders are able to tell that route was only 'guessed'. */
02927     bool      path_not_found = false;
02928     TileIndex new_tile = res_dest.tile;
02929 
02930     Track next_track = DoTrainPathfind(v, new_tile, dest_enterdir, tracks, &path_not_found, do_track_reservation, &res_dest);
02931     if (new_tile == tile) best_track = next_track;
02932 
02933     /* handle "path not found" state */
02934     if (path_not_found) {
02935       /* PF didn't find the route */
02936       if (!HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
02937         /* it is first time the problem occurred, set the "path not found" flag */
02938         SetBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
02939         /* and notify user about the event */
02940         AI::NewEvent(v->owner, new AIEventVehicleLost(v->index));
02941         if (_settings_client.gui.lost_train_warn && v->owner == _local_company) {
02942           SetDParam(0, v->index);
02943           AddNewsItem(
02944             STR_TRAIN_IS_LOST,
02945             NS_ADVICE,
02946             v->index,
02947             0);
02948         }
02949       }
02950     } else {
02951       /* route found, is the train marked with "path not found" flag? */
02952       if (HasBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
02953         /* clear the flag as the PF's problem was solved */
02954         ClrBit(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
02955         /* can we also delete the "News" item somehow? */
02956       }
02957     }
02958   }
02959 
02960   /* No track reservation requested -> finished. */
02961   if (!do_track_reservation) return best_track;
02962 
02963   /* A path was found, but could not be reserved. */
02964   if (res_dest.tile != INVALID_TILE && !res_dest.okay) {
02965     if (mark_stuck) MarkTrainAsStuck(v);
02966     FreeTrainTrackReservation(v);
02967     return best_track;
02968   }
02969 
02970   /* No possible reservation target found, we are probably lost. */
02971   if (res_dest.tile == INVALID_TILE) {
02972     /* Try to find any safe destination. */
02973     PBSTileInfo origin = FollowTrainReservation(v);
02974     if (TryReserveSafeTrack(v, origin.tile, origin.trackdir, false)) {
02975       TrackBits res = GetReservedTrackbits(tile) & DiagdirReachesTracks(enterdir);
02976       best_track = FindFirstTrack(res);
02977       TryReserveRailTrack(v->tile, TrackdirToTrack(GetVehicleTrackdir(v)));
02978       if (got_reservation != NULL) *got_reservation = true;
02979       if (changed_signal) MarkTileDirtyByTile(tile);
02980     } else {
02981       FreeTrainTrackReservation(v);
02982       if (mark_stuck) MarkTrainAsStuck(v);
02983     }
02984     return best_track;
02985   }
02986 
02987   if (got_reservation != NULL) *got_reservation = true;
02988 
02989   /* Reservation target found and free, check if it is safe. */
02990   while (!IsSafeWaitingPosition(v, res_dest.tile, res_dest.trackdir, true, _settings_game.pf.forbid_90_deg)) {
02991     /* Extend reservation until we have found a safe position. */
02992     DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
02993     TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
02994     TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
02995     if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
02996       reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
02997     }
02998 
02999     /* Get next order with destination. */
03000     if (orders.SwitchToNextOrder(true)) {
03001       PBSTileInfo cur_dest;
03002       DoTrainPathfind(v, next_tile, exitdir, reachable, NULL, true, &cur_dest);
03003       if (cur_dest.tile != INVALID_TILE) {
03004         res_dest = cur_dest;
03005         if (res_dest.okay) continue;
03006         /* Path found, but could not be reserved. */
03007         FreeTrainTrackReservation(v);
03008         if (mark_stuck) MarkTrainAsStuck(v);
03009         if (got_reservation != NULL) *got_reservation = false;
03010         changed_signal = false;
03011         break;
03012       }
03013     }
03014     /* No order or no safe position found, try any position. */
03015     if (!TryReserveSafeTrack(v, res_dest.tile, res_dest.trackdir, true)) {
03016       FreeTrainTrackReservation(v);
03017       if (mark_stuck) MarkTrainAsStuck(v);
03018       if (got_reservation != NULL) *got_reservation = false;
03019       changed_signal = false;
03020     }
03021     break;
03022   }
03023 
03024   TryReserveRailTrack(v->tile, TrackdirToTrack(GetVehicleTrackdir(v)));
03025 
03026   if (changed_signal) MarkTileDirtyByTile(tile);
03027 
03028   return best_track;
03029 }
03030 
03039 bool TryPathReserve(Vehicle *v, bool mark_as_stuck, bool first_tile_okay)
03040 {
03041   assert(v->type == VEH_TRAIN && IsFrontEngine(v));
03042 
03043   /* We have to handle depots specially as the track follower won't look
03044    * at the depot tile itself but starts from the next tile. If we are still
03045    * inside the depot, a depot reservation can never be ours. */
03046   if (v->u.rail.track & TRACK_BIT_DEPOT) {
03047     if (GetDepotWaypointReservation(v->tile)) {
03048       if (mark_as_stuck) MarkTrainAsStuck(v);
03049       return false;
03050     } else {
03051       /* Depot not reserved, but the next tile might be. */
03052       TileIndex next_tile = TileAddByDiagDir(v->tile, GetRailDepotDirection(v->tile));
03053       if (HasReservedTracks(next_tile, DiagdirReachesTracks(GetRailDepotDirection(v->tile)))) return false;
03054     }
03055   }
03056 
03057   /* Special check if we are in front of a two-sided conventional signal. */
03058   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
03059   TileIndex next_tile = TileAddByDiagDir(v->tile, dir);
03060   if (IsTileType(next_tile, MP_RAILWAY) && HasReservedTracks(next_tile, DiagdirReachesTracks(dir))) {
03061     /* Can have only one reserved trackdir. */
03062     Trackdir td = FindFirstTrackdir(TrackBitsToTrackdirBits(GetReservedTrackbits(next_tile)) & DiagdirReachesTrackdirs(dir));
03063     if (HasSignalOnTrackdir(next_tile, td) && HasSignalOnTrackdir(next_tile, ReverseTrackdir(td)) &&
03064         !IsPbsSignal(GetSignalType(next_tile, TrackdirToTrack(td)))) {
03065       /* Signal already reserved, is not ours. */
03066       if (mark_as_stuck) MarkTrainAsStuck(v);
03067       return false;
03068     }
03069   }
03070 
03071   bool other_train = false;
03072   PBSTileInfo origin = FollowTrainReservation(v, &other_train);
03073   /* If we have a reserved path and the path ends at a safe tile, we are finished already. */
03074   if (origin.okay && (v->tile != origin.tile || first_tile_okay)) {
03075     /* Can't be stuck then. */
03076     if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03077     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
03078     return true;
03079   }
03080   /* The path we are driving on is alread blocked by some other train.
03081    * This can only happen when tracks and signals are changed. A crash
03082    * is probably imminent, don't do any further reservation because
03083    * it might cause stale reservations. */
03084   if (other_train && v->tile != origin.tile) {
03085     if (mark_as_stuck) MarkTrainAsStuck(v);
03086     return false;
03087   }
03088 
03089   /* If we are in a depot, tentativly reserve the depot. */
03090   if (v->u.rail.track & TRACK_BIT_DEPOT) {
03091     SetDepotWaypointReservation(v->tile, true);
03092     if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
03093   }
03094 
03095   DiagDirection exitdir = TrackdirToExitdir(origin.trackdir);
03096   TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
03097   TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
03098 
03099   if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
03100 
03101   bool res_made = false;
03102   ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
03103 
03104   if (!res_made) {
03105     /* Free the depot reservation as well. */
03106     if (v->u.rail.track & TRACK_BIT_DEPOT) SetDepotWaypointReservation(v->tile, false);
03107     return false;
03108   }
03109 
03110   if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
03111     v->load_unload_time_rem = 0;
03112     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03113   }
03114   ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
03115   return true;
03116 }
03117 
03118 
03119 static bool CheckReverseTrain(Vehicle *v)
03120 {
03121   if (_settings_game.difficulty.line_reverse_mode != 0 ||
03122       v->u.rail.track == TRACK_BIT_DEPOT || v->u.rail.track == TRACK_BIT_WORMHOLE ||
03123       !(v->direction & 1)) {
03124     return false;
03125   }
03126 
03127   uint reverse_best = 0;
03128 
03129   assert(v->u.rail.track);
03130 
03131   switch (_settings_game.pf.pathfinder_for_trains) {
03132     case VPF_YAPF: // YAPF
03133       reverse_best = YapfCheckReverseTrain(v);
03134       break;
03135 
03136     case VPF_NPF: { // NPF
03137       NPFFindStationOrTileData fstd;
03138       NPFFoundTargetData ftd;
03139       Vehicle *last = GetLastVehicleInChain(v);
03140 
03141       NPFFillWithOrderData(&fstd, v);
03142 
03143       Trackdir trackdir = GetVehicleTrackdir(v);
03144       Trackdir trackdir_rev = ReverseTrackdir(GetVehicleTrackdir(last));
03145       assert(trackdir != INVALID_TRACKDIR);
03146       assert(trackdir_rev != INVALID_TRACKDIR);
03147 
03148       ftd = NPFRouteToStationOrTileTwoWay(v->tile, trackdir, false, last->tile, trackdir_rev, false, &fstd, TRANSPORT_RAIL, 0, v->owner, v->u.rail.compatible_railtypes);
03149       if (ftd.best_bird_dist != 0) {
03150         /* We didn't find anything, just keep on going straight ahead */
03151         reverse_best = false;
03152       } else {
03153         if (NPFGetFlag(&ftd.node, NPF_FLAG_REVERSE)) {
03154           reverse_best = true;
03155         } else {
03156           reverse_best = false;
03157         }
03158       }
03159     } break;
03160 
03161     default:
03162     case VPF_NTP: { // NTP
03163       TrainTrackFollowerData fd;
03164       FillWithStationData(&fd, v);
03165 
03166       int i = _search_directions[FindFirstTrack(v->u.rail.track)][DirToDiagDir(v->direction)];
03167 
03168       int best_track = -1;
03169       uint reverse = 0;
03170       uint best_bird_dist  = 0;
03171       uint best_track_dist = 0;
03172 
03173       for (;;) {
03174         fd.best_bird_dist = UINT_MAX;
03175         fd.best_track_dist = UINT_MAX;
03176 
03177         NewTrainPathfind(v->tile, v->dest_tile, v->u.rail.compatible_railtypes, (DiagDirection)(reverse ^ i), (NTPEnumProc*)NtpCallbFindStation, &fd);
03178 
03179         if (best_track != -1) {
03180           if (best_bird_dist != 0) {
03181             if (fd.best_bird_dist != 0) {
03182               /* neither reached the destination, pick the one with the smallest bird dist */
03183               if (fd.best_bird_dist > best_bird_dist) goto bad;
03184               if (fd.best_bird_dist < best_bird_dist) goto good;
03185             } else {
03186               /* we found the destination for the first time */
03187               goto good;
03188             }
03189           } else {
03190             if (fd.best_bird_dist != 0) {
03191               /* didn't find destination, but we've found the destination previously */
03192               goto bad;
03193             } else {
03194               /* both old & new reached the destination, compare track length */
03195               if (fd.best_track_dist > best_track_dist) goto bad;
03196               if (fd.best_track_dist < best_track_dist) goto good;
03197             }
03198           }
03199 
03200           /* if we reach this position, there's two paths of equal value so far.
03201            * pick one randomly. */
03202           int r = GB(Random(), 0, 8);
03203           if (_pick_track_table[i] == (v->direction & 3)) r += 80;
03204           if (_pick_track_table[best_track] == (v->direction & 3)) r -= 80;
03205           if (r <= 127) goto bad;
03206         }
03207 good:;
03208         best_track = i;
03209         best_bird_dist = fd.best_bird_dist;
03210         best_track_dist = fd.best_track_dist;
03211         reverse_best = reverse;
03212 bad:;
03213         if (reverse != 0) break;
03214         reverse = 2;
03215       }
03216     } break;
03217   }
03218 
03219   return reverse_best != 0;
03220 }
03221 
03222 TileIndex Train::GetOrderStationLocation(StationID station)
03223 {
03224   if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;
03225 
03226   const Station *st = GetStation(station);
03227   if (!(st->facilities & FACIL_TRAIN)) {
03228     /* The destination station has no trainstation tiles. */
03229     this->cur_order_index++;
03230     return 0;
03231   }
03232 
03233   return st->xy;
03234 }
03235 
03236 void Train::MarkDirty()
03237 {
03238   Vehicle *v = this;
03239   do {
03240     v->cur_image = v->GetImage(v->direction);
03241     MarkSingleVehicleDirty(v);
03242   } while ((v = v->Next()) != NULL);
03243 
03244   /* need to update acceleration and cached values since the goods on the train changed. */
03245   TrainCargoChanged(this);
03246   UpdateTrainAcceleration(this);
03247 }
03248 
03259 static int UpdateTrainSpeed(Vehicle *v)
03260 {
03261   uint accel;
03262 
03263   if (v->vehstatus & VS_STOPPED || HasBit(v->u.rail.flags, VRF_REVERSING) || HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
03264     switch (_settings_game.vehicle.train_acceleration_model) {
03265       default: NOT_REACHED();
03266       case TAM_ORIGINAL:  accel = v->acceleration * -4; break;
03267       case TAM_REALISTIC: accel = GetTrainAcceleration(v, AM_BRAKE); break;
03268     }
03269   } else {
03270     switch (_settings_game.vehicle.train_acceleration_model) {
03271       default: NOT_REACHED();
03272       case TAM_ORIGINAL:  accel = v->acceleration * 2; break;
03273       case TAM_REALISTIC: accel = GetTrainAcceleration(v, AM_ACCEL); break;
03274     }
03275   }
03276 
03277   uint spd = v->subspeed + accel;
03278   v->subspeed = (byte)spd;
03279   {
03280     int tempmax = v->max_speed;
03281     if (v->cur_speed > v->max_speed)
03282       tempmax = v->cur_speed - (v->cur_speed / 10) - 1;
03283     v->cur_speed = spd = Clamp(v->cur_speed + ((int)spd >> 8), 0, tempmax);
03284   }
03285 
03286   /* Scale speed by 3/4. Previously this was only done when the train was
03287    * facing diagonally and would apply to however many moves the train made
03288    * regardless the of direction actually moved in. Now it is always scaled,
03289    * 256 spd is used to go straight and 192 is used to go diagonally
03290    * (3/4 of 256). This results in the same effect, but without the error the
03291    * previous method caused.
03292    *
03293    * The scaling is done in this direction and not by multiplying the amount
03294    * to be subtracted by 4/3 so that the leftover speed can be saved in a
03295    * byte in v->progress.
03296    */
03297   int scaled_spd = spd * 3 >> 2;
03298 
03299   scaled_spd += v->progress;
03300   v->progress = 0; // set later in TrainLocoHandler or TrainController
03301   return scaled_spd;
03302 }
03303 
03304 static void TrainEnterStation(Vehicle *v, StationID station)
03305 {
03306   v->last_station_visited = station;
03307 
03308   /* check if a train ever visited this station before */
03309   Station *st = GetStation(station);
03310   if (!(st->had_vehicle_of_type & HVOT_TRAIN)) {
03311     st->had_vehicle_of_type |= HVOT_TRAIN;
03312     SetDParam(0, st->index);
03313     AddNewsItem(
03314       STR_8801_CITIZENS_CELEBRATE_FIRST,
03315       v->owner == _local_company ? NS_ARRIVAL_COMPANY : NS_ARRIVAL_OTHER,
03316       v->index,
03317       st->index
03318     );
03319     AI::NewEvent(v->owner, new AIEventStationFirstVehicle(st->index, v->index));
03320   }
03321 
03322   v->BeginLoading();
03323 
03324   StationAnimationTrigger(st, v->tile, STAT_ANIM_TRAIN_ARRIVES);
03325 }
03326 
03327 static byte AfterSetTrainPos(Vehicle *v, bool new_tile)
03328 {
03329   byte old_z = v->z_pos;
03330   v->z_pos = GetSlopeZ(v->x_pos, v->y_pos);
03331 
03332   if (new_tile) {
03333     ClrBit(v->u.rail.flags, VRF_GOINGUP);
03334     ClrBit(v->u.rail.flags, VRF_GOINGDOWN);
03335 
03336     if (v->u.rail.track == TRACK_BIT_X || v->u.rail.track == TRACK_BIT_Y) {
03337       /* Any track that isn't TRACK_BIT_X or TRACK_BIT_Y cannot be sloped.
03338        * To check whether the current tile is sloped, and in which
03339        * direction it is sloped, we get the 'z' at the center of
03340        * the tile (middle_z) and the edge of the tile (old_z),
03341        * which we then can compare. */
03342       static const int HALF_TILE_SIZE = TILE_SIZE / 2;
03343       static const int INV_TILE_SIZE_MASK = ~(TILE_SIZE - 1);
03344 
03345       byte middle_z = GetSlopeZ((v->x_pos & INV_TILE_SIZE_MASK) | HALF_TILE_SIZE, (v->y_pos & INV_TILE_SIZE_MASK) | HALF_TILE_SIZE);
03346 
03347       /* For some reason tunnel tiles are always given as sloped :(
03348        * But they are not sloped... */
03349       if (middle_z != v->z_pos && !IsTunnelTile(TileVirtXY(v->x_pos, v->y_pos))) {
03350         SetBit(v->u.rail.flags, (middle_z > old_z) ? VRF_GOINGUP : VRF_GOINGDOWN);
03351       }
03352     }
03353   }
03354 
03355   VehicleMove(v, true);
03356   return old_z;
03357 }
03358 
03359 static const Direction _new_vehicle_direction_table[11] = {
03360   DIR_N , DIR_NW, DIR_W , INVALID_DIR,
03361   DIR_NE, DIR_N , DIR_SW, INVALID_DIR,
03362   DIR_E , DIR_SE, DIR_S
03363 };
03364 
03365 static inline Direction GetNewVehicleDirectionByTile(TileIndex new_tile, TileIndex old_tile)
03366 {
03367   uint offs = (TileY(new_tile) - TileY(old_tile) + 1) * 4 +
03368               TileX(new_tile) - TileX(old_tile) + 1;
03369   assert(offs < 11);
03370   return _new_vehicle_direction_table[offs];
03371 }
03372 
03373 static inline int GetDirectionToVehicle(const Vehicle *v, int x, int y)
03374 {
03375   byte offs;
03376 
03377   x -= v->x_pos;
03378   if (x >= 0) {
03379     offs = (x > 2) ? 0 : 1;
03380   } else {
03381     offs = (x < -2) ? 2 : 1;
03382   }
03383 
03384   y -= v->y_pos;
03385   if (y >= 0) {
03386     offs += ((y > 2) ? 0 : 1) * 4;
03387   } else {
03388     offs += ((y < -2) ? 2 : 1) * 4;
03389   }
03390 
03391   assert(offs < 11);
03392   return _new_vehicle_direction_table[offs];
03393 }
03394 
03395 /* Check if the vehicle is compatible with the specified tile */
03396 static inline bool CheckCompatibleRail(const Vehicle *v, TileIndex tile)
03397 {
03398   return
03399     IsTileOwner(tile, v->owner) && (
03400       !IsFrontEngine(v) ||
03401       HasBit(v->u.rail.compatible_railtypes, GetRailType(tile))
03402     );
03403 }
03404 
03405 struct RailtypeSlowdownParams {
03406   byte small_turn, large_turn;
03407   byte z_up; // fraction to remove when moving up
03408   byte z_down; // fraction to remove when moving down
03409 };
03410 
03411 static const RailtypeSlowdownParams _railtype_slowdown[] = {
03412   /* normal accel */
03413   {256 / 4, 256 / 2, 256 / 4, 2}, 
03414   {256 / 4, 256 / 2, 256 / 4, 2}, 
03415   {256 / 4, 256 / 2, 256 / 4, 2}, 
03416   {0,       256 / 2, 256 / 4, 2}, 
03417 };
03418 
03420 static inline void AffectSpeedByDirChange(Vehicle *v, Direction new_dir)
03421 {
03422   if (_settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL) return;
03423 
03424   DirDiff diff = DirDifference(v->direction, new_dir);
03425   if (diff == DIRDIFF_SAME) return;
03426 
03427   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->u.rail.railtype];
03428   v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8;
03429 }
03430 
03432 static inline void AffectSpeedByZChange(Vehicle *v, byte old_z)
03433 {
03434   if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL) return;
03435 
03436   const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->u.rail.railtype];
03437 
03438   if (old_z < v->z_pos) {
03439     v->cur_speed -= (v->cur_speed * rsp->z_up >> 8);
03440   } else {
03441     uint16 spd = v->cur_speed + rsp->z_down;
03442     if (spd <= v->max_speed) v->cur_speed = spd;
03443   }
03444 }
03445 
03446 static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
03447 {
03448   if (IsTileType(tile, MP_RAILWAY) &&
03449       GetRailTileType(tile) == RAIL_TILE_SIGNALS) {
03450     TrackdirBits tracks = TrackBitsToTrackdirBits(GetTrackBits(tile)) & DiagdirReachesTrackdirs(dir);
03451     Trackdir trackdir = FindFirstTrackdir(tracks);
03452     if (UpdateSignalsOnSegment(tile,  TrackdirToExitdir(trackdir), GetTileOwner(tile)) == SIGSEG_PBS && HasSignalOnTrackdir(tile, trackdir)) {
03453       /* A PBS block with a non-PBS signal facing us? */
03454       if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
03455     }
03456   }
03457   return false;
03458 }
03459 
03460 
03461 static void SetVehicleCrashed(Vehicle *v)
03462 {
03463   if (v->u.rail.crash_anim_pos != 0) return;
03464 
03465   /* Free a possible path reservation and try to mark all tiles occupied by the train reserved. */
03466   if (IsFrontEngine(v)) {
03467     /* Remove all reservations, also the ones currently under the train
03468      * and any railway station paltform reservation. */
03469     FreeTrainTrackReservation(v);
03470     for (const Vehicle *u = v; u != NULL; u = u->Next()) {
03471       ClearPathReservation(u, u->tile, GetVehicleTrackdir(u));
03472       if (IsTileType(u->tile, MP_TUNNELBRIDGE)) {
03473         /* ClearPathReservation will not free the wormhole exit
03474          * if the train has just entered the wormhole. */
03475         SetTunnelBridgeReservation(GetOtherTunnelBridgeEnd(u->tile), false);
03476       }
03477     }
03478   }
03479 
03480   /* we may need to update crossing we were approaching */
03481   TileIndex crossing = TrainApproachingCrossingTile(v);
03482 
03483   v->u.rail.crash_anim_pos++;
03484 
03485   InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
03486   InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
03487 
03488   if (v->u.rail.track == TRACK_BIT_DEPOT) {
03489     InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
03490   }
03491 
03492   InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
03493 
03494   for (; v != NULL; v = v->Next()) {
03495     v->vehstatus |= VS_CRASHED;
03496     MarkSingleVehicleDirty(v);
03497   }
03498 
03499   /* must be updated after the train has been marked crashed */
03500   if (crossing != INVALID_TILE) UpdateLevelCrossing(crossing);
03501 }
03502 
03503 static uint CountPassengersInTrain(const Vehicle *v)
03504 {
03505   uint num = 0;
03506 
03507   for (; v != NULL; v = v->Next()) {
03508     if (IsCargoInClass(v->cargo_type, CC_PASSENGERS)) num += v->cargo.Count();
03509   }
03510 
03511   return num;
03512 }
03513 
03520 static uint TrainCrashed(Vehicle *v)
03521 {
03522   /* do not crash train twice */
03523   if (v->vehstatus & VS_CRASHED) return 0;
03524 
03525   /* two drivers + passengers */
03526   uint num = 2 + CountPassengersInTrain(v);
03527 
03528   SetVehicleCrashed(v);
03529   AI::NewEvent(v->owner, new AIEventVehicleCrashed(v->index, v->tile, AIEventVehicleCrashed::CRASH_TRAIN));
03530 
03531   return num;
03532 }
03533 
03534 struct TrainCollideChecker {
03535   Vehicle *v;  
03536   uint num;    
03537 };
03538 
03539 static Vehicle *FindTrainCollideEnum(Vehicle *v, void *data)
03540 {
03541   TrainCollideChecker *tcc = (TrainCollideChecker*)data;
03542 
03543   if (v->type != VEH_TRAIN) return NULL;
03544 
03545   /* get first vehicle now to make most usual checks faster */
03546   Vehicle *coll = v->First();
03547 
03548   /* can't collide with own wagons && can't crash in depot && the same height level */
03549   if (coll != tcc->v && v->u.rail.track != TRACK_BIT_DEPOT && abs(v->z_pos - tcc->v->z_pos) < 6) {
03550     int x_diff = v->x_pos - tcc->v->x_pos;
03551     int y_diff = v->y_pos - tcc->v->y_pos;
03552 
03553     /* needed to disable possible crash of competitor train in station by building diagonal track at its end */
03554     if (x_diff * x_diff + y_diff * y_diff > 25) return NULL;
03555 
03556     /* crash both trains */
03557     tcc->num += TrainCrashed(tcc->v);
03558     tcc->num += TrainCrashed(coll);
03559 
03560     /* Try to reserve all tiles directly under the crashed trains.
03561      * As there might be more than two trains involved, we have to do that for all vehicles */
03562     const Vehicle *u;
03563     FOR_ALL_VEHICLES(u) {
03564       if (u->type == VEH_TRAIN && HASBITS(u->vehstatus, VS_CRASHED) && (u->u.rail.track & TRACK_BIT_DEPOT) == TRACK_BIT_NONE) {
03565         TrackBits trackbits = u->u.rail.track;
03566         if ((trackbits & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03567           /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03568           trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(u->tile));
03569         }
03570         TryReserveRailTrack(u->tile, TrackBitsToTrack(trackbits));
03571       }
03572     }
03573   }
03574 
03575   return NULL;
03576 }
03577 
03584 static bool CheckTrainCollision(Vehicle *v)
03585 {
03586   /* can't collide in depot */
03587   if (v->u.rail.track == TRACK_BIT_DEPOT) return false;
03588 
03589   assert(v->u.rail.track == TRACK_BIT_WORMHOLE || TileVirtXY(v->x_pos, v->y_pos) == v->tile);
03590 
03591   TrainCollideChecker tcc;
03592   tcc.v = v;
03593   tcc.num = 0;
03594 
03595   /* find colliding vehicles */
03596   if (v->u.rail.track == TRACK_BIT_WORMHOLE) {
03597     FindVehicleOnPos(v->tile, &tcc, FindTrainCollideEnum);
03598     FindVehicleOnPos(GetOtherTunnelBridgeEnd(v->tile), &tcc, FindTrainCollideEnum);
03599   } else {
03600     FindVehicleOnPosXY(v->x_pos, v->y_pos, &tcc, FindTrainCollideEnum);
03601   }
03602 
03603   /* any dead -> no crash */
03604   if (tcc.num == 0) return false;
03605 
03606   SetDParam(0, tcc.num);
03607   AddNewsItem(STR_8868_TRAIN_CRASH_DIE_IN_FIREBALL,
03608     NS_ACCIDENT_VEHICLE,
03609     v->index,
03610     0
03611   );
03612 
03613   ModifyStationRatingAround(v->tile, v->owner, -160, 30);
03614   SndPlayVehicleFx(SND_13_BIG_CRASH, v);
03615   return true;
03616 }
03617 
03618 static Vehicle *CheckVehicleAtSignal(Vehicle *v, void *data)
03619 {
03620   DiagDirection exitdir = *(DiagDirection *)data;
03621 
03622   /* front engine of a train, not inside wormhole or depot, not crashed */
03623   if (v->type == VEH_TRAIN && IsFrontEngine(v) && (v->u.rail.track & TRACK_BIT_MASK) != 0 && !(v->vehstatus & VS_CRASHED)) {
03624     if (v->cur_speed <= 5 && TrainExitDir(v->direction, v->u.rail.track) == exitdir) return v;
03625   }
03626 
03627   return NULL;
03628 }
03629 
03630 static void TrainController(Vehicle *v, Vehicle *nomove)
03631 {
03632   Vehicle *prev;
03633 
03634   /* For every vehicle after and including the given vehicle */
03635   for (prev = v->Previous(); v != nomove; prev = v, v = v->Next()) {
03636     DiagDirection enterdir = DIAGDIR_BEGIN;
03637     bool update_signals_crossing = false; // will we update signals or crossing state?
03638 
03639     GetNewVehiclePosResult gp = GetNewVehiclePos(v);
03640     if (v->u.rail.track != TRACK_BIT_WORMHOLE) {
03641       /* Not inside tunnel */
03642       if (gp.old_tile == gp.new_tile) {
03643         /* Staying in the old tile */
03644         if (v->u.rail.track == TRACK_BIT_DEPOT) {
03645           /* Inside depot */
03646           gp.x = v->x_pos;
03647           gp.y = v->y_pos;
03648         } else {
03649           /* Not inside depot */
03650 
03651           /* Reverse when we are at the end of the track already, do not move to the new position */
03652           if (IsFrontEngine(v) && !TrainCheckIfLineEnds(v)) return;
03653 
03654           uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03655           if (HasBit(r, VETS_CANNOT_ENTER)) {
03656             goto invalid_rail;
03657           }
03658           if (HasBit(r, VETS_ENTERED_STATION)) {
03659             /* The new position is the end of the platform */
03660             TrainEnterStation(v, r >> VETS_STATION_ID_OFFSET);
03661           }
03662         }
03663       } else {
03664         /* A new tile is about to be entered. */
03665 
03666         /* Determine what direction we're entering the new tile from */
03667         Direction dir = GetNewVehicleDirectionByTile(gp.new_tile, gp.old_tile);
03668         enterdir = DirToDiagDir(dir);
03669         assert(IsValidDiagDirection(enterdir));
03670 
03671         /* Get the status of the tracks in the new tile and mask
03672          * away the bits that aren't reachable. */
03673         TrackStatus ts = GetTileTrackStatus(gp.new_tile, TRANSPORT_RAIL, 0, ReverseDiagDir(enterdir));
03674         TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(enterdir);
03675 
03676         TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
03677         TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
03678 
03679         TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
03680         if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg && prev == NULL) {
03681           /* We allow wagons to make 90 deg turns, because forbid_90_deg
03682            * can be switched on halfway a turn */
03683           bits &= ~TrackCrossesTracks(FindFirstTrack(v->u.rail.track));
03684         }
03685 
03686         if (bits == TRACK_BIT_NONE) goto invalid_rail;
03687 
03688         /* Check if the new tile contrains tracks that are compatible
03689          * with the current train, if not, bail out. */
03690         if (!CheckCompatibleRail(v, gp.new_tile)) goto invalid_rail;
03691 
03692         TrackBits chosen_track;
03693         if (prev == NULL) {
03694           /* Currently the locomotive is active. Determine which one of the
03695            * available tracks to choose */
03696           chosen_track = TrackToTrackBits(ChooseTrainTrack(v, gp.new_tile, enterdir, bits, false, NULL, true));
03697           assert(chosen_track & (bits | GetReservedTrackbits(gp.new_tile)));
03698 
03699           /* Check if it's a red signal and that force proceed is not clicked. */
03700           if (red_signals & chosen_track && v->u.rail.force_proceed == 0) {
03701             /* In front of a red signal */
03702             Trackdir i = FindFirstTrackdir(trackdirbits);
03703 
03704             /* Don't handle stuck trains here. */
03705             if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) return;
03706 
03707             if (!HasSignalOnTrackdir(gp.new_tile, ReverseTrackdir(i))) {
03708               v->cur_speed = 0;
03709               v->subspeed = 0;
03710               v->progress = 255 - 100;
03711               if (_settings_game.pf.wait_oneway_signal == 255 || ++v->load_unload_time_rem < _settings_game.pf.wait_oneway_signal * 20) return;
03712             } else if (HasSignalOnTrackdir(gp.new_tile, i)) {
03713               v->cur_speed = 0;
03714               v->subspeed = 0;
03715               v->progress = 255 - 10;
03716               if (_settings_game.pf.wait_twoway_signal == 255 || ++v->load_unload_time_rem < _settings_game.pf.wait_twoway_signal * 73) {
03717                 DiagDirection exitdir = TrackdirToExitdir(i);
03718                 TileIndex o_tile = TileAddByDiagDir(gp.new_tile, exitdir);
03719 
03720                 exitdir = ReverseDiagDir(exitdir);
03721 
03722                 /* check if a train is waiting on the other side */
03723                 if (!HasVehicleOnPos(o_tile, &exitdir, &CheckVehicleAtSignal)) return;
03724               }
03725             }
03726 
03727             /* If we would reverse but are currently in a PBS block and
03728              * reversing of stuck trains is disabled, don't reverse. */
03729             if (_settings_game.pf.wait_for_pbs_path == 255 && UpdateSignalsOnSegment(v->tile, enterdir, v->owner) == SIGSEG_PBS) {
03730               v->load_unload_time_rem = 0;
03731               return;
03732             }
03733             goto reverse_train_direction;
03734           } else {
03735             TryReserveRailTrack(gp.new_tile, TrackBitsToTrack(chosen_track));
03736           }
03737         } else {
03738           static const TrackBits _matching_tracks[8] = {
03739               TRACK_BIT_LEFT  | TRACK_BIT_RIGHT, TRACK_BIT_X,
03740               TRACK_BIT_UPPER | TRACK_BIT_LOWER, TRACK_BIT_Y,
03741               TRACK_BIT_LEFT  | TRACK_BIT_RIGHT, TRACK_BIT_X,
03742               TRACK_BIT_UPPER | TRACK_BIT_LOWER, TRACK_BIT_Y
03743           };
03744 
03745           /* The wagon is active, simply follow the prev vehicle. */
03746           chosen_track = (TrackBits)(byte)(_matching_tracks[GetDirectionToVehicle(prev, gp.x, gp.y)] & bits);
03747         }
03748 
03749         /* Make sure chosen track is a valid track */
03750         assert(
03751             chosen_track == TRACK_BIT_X     || chosen_track == TRACK_BIT_Y ||
03752             chosen_track == TRACK_BIT_UPPER || chosen_track == TRACK_BIT_LOWER ||
03753             chosen_track == TRACK_BIT_LEFT  || chosen_track == TRACK_BIT_RIGHT);
03754 
03755         /* Update XY to reflect the entrance to the new tile, and select the direction to use */
03756         const byte *b = _initial_tile_subcoord[FIND_FIRST_BIT(chosen_track)][enterdir];
03757         gp.x = (gp.x & ~0xF) | b[0];
03758         gp.y = (gp.y & ~0xF) | b[1];
03759         Direction chosen_dir = (Direction)b[2];
03760 
03761         /* Call the landscape function and tell it that the vehicle entered the tile */
03762         uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
03763         if (HasBit(r, VETS_CANNOT_ENTER)) {
03764           goto invalid_rail;
03765         }
03766 
03767         if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
03768           Track track = FindFirstTrack(chosen_track);
03769           Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
03770           if (IsFrontEngine(v) && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
03771             SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
03772             MarkTileDirtyByTile(gp.new_tile);
03773           }
03774 
03775           /* Clear any track reservation when the last vehicle leaves the tile */
03776           if (v->Next() == NULL) ClearPathReservation(v, v->tile, GetVehicleTrackdir(v));
03777 
03778           v->tile = gp.new_tile;
03779 
03780           if (GetTileRailType(gp.new_tile) != GetTileRailType(gp.old_tile)) {
03781             TrainPowerChanged(v->First());
03782           }
03783 
03784           v->u.rail.track = chosen_track;
03785           assert(v->u.rail.track);
03786         }
03787 
03788         /* We need to update signal status, but after the vehicle position hash
03789          * has been updated by AfterSetTrainPos() */
03790         update_signals_crossing = true;
03791 
03792         if (prev == NULL) AffectSpeedByDirChange(v, chosen_dir);
03793 
03794         v->direction = chosen_dir;
03795 
03796         if (IsFrontEngine(v)) {
03797           v->load_unload_time_rem = 0;
03798 
03799           /* If we are approching a crossing that is reserved, play the sound now. */
03800           TileIndex crossing = TrainApproachingCrossingTile(v);
03801           if (crossing != INVALID_TILE && GetCrossingReservation(crossing)) SndPlayTileFx(SND_0E_LEVEL_CROSSING, crossing);
03802 
03803           /* Always try to extend the reservation when entering a tile. */
03804           CheckNextTrainTile(v);
03805         }
03806       }
03807     } else {
03808       /* In a tunnel or on a bridge
03809        * - for tunnels, only the part when the vehicle is not visible (part of enter/exit tile too)
03810        * - for bridges, only the middle part - without the bridge heads */
03811       if (!(v->vehstatus & VS_HIDDEN)) {
03812         v->cur_speed =
03813           min(v->cur_speed, GetBridgeSpec(GetBridgeType(v->tile))->speed);
03814       }
03815 
03816       if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
03817         /* Perform look-ahead on tunnel exit. */
03818         if (IsFrontEngine(v)) {
03819           TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
03820           CheckNextTrainTile(v);
03821         }
03822       } else {
03823         v->x_pos = gp.x;
03824         v->y_pos = gp.y;
03825         VehicleMove(v, !(v->vehstatus & VS_HIDDEN));
03826         continue;
03827       }
03828     }
03829 
03830     /* update image of train, as well as delta XY */
03831     v->UpdateDeltaXY(v->direction);
03832 
03833     v->x_pos = gp.x;
03834     v->y_pos = gp.y;
03835 
03836     /* update the Z position of the vehicle */
03837     byte old_z = AfterSetTrainPos(v, (gp.new_tile != gp.old_tile));
03838 
03839     if (prev == NULL) {
03840       /* This is the first vehicle in the train */
03841       AffectSpeedByZChange(v, old_z);
03842     }
03843 
03844     if (update_signals_crossing) {
03845       if (IsFrontEngine(v)) {
03846         if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
03847           /* We are entering a block with PBS signals right now, but
03848            * not through a PBS signal. This means we don't have a
03849            * reservation right now. As a conventional signal will only
03850            * ever be green if no other train is in the block, getting
03851            * a path should always be possible. If the player built
03852            * such a strange network that it is not possible, the train
03853            * will be marked as stuck and the player has to deal with
03854            * the problem. */
03855           if ((!HasReservedTracks(gp.new_tile, v->u.rail.track) &&
03856               !TryReserveRailTrack(gp.new_tile, FindFirstTrack(v->u.rail.track))) ||
03857               !TryPathReserve(v)) {
03858             MarkTrainAsStuck(v);
03859           }
03860         }
03861       }
03862 
03863       /* Signals can only change when the first
03864        * (above) or the last vehicle moves. */
03865       if (v->Next() == NULL) {
03866         TrainMovedChangeSignals(gp.old_tile, ReverseDiagDir(enterdir));
03867         if (IsLevelCrossingTile(gp.old_tile)) UpdateLevelCrossing(gp.old_tile);
03868       }
03869     }
03870 
03871     /* Do not check on every tick to save some computing time. */
03872     if (IsFrontEngine(v) && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
03873   }
03874   return;
03875 
03876 invalid_rail:
03877   /* We've reached end of line?? */
03878   if (prev != NULL) error("Disconnecting train");
03879 
03880 reverse_train_direction:
03881   v->load_unload_time_rem = 0;
03882   v->cur_speed = 0;
03883   v->subspeed = 0;
03884   ReverseTrainDirection(v);
03885 }
03886 
03892 static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
03893 {
03894   TrackBits *trackbits = (TrackBits *)data;
03895 
03896   if (v->type == VEH_TRAIN && (v->vehstatus & VS_CRASHED) != 0) {
03897     if ((v->u.rail.track & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03898       /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03899       *trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile));
03900     } else {
03901       *trackbits |= v->u.rail.track;
03902     }
03903   }
03904 
03905   return NULL;
03906 }
03907 
03915 static void DeleteLastWagon(Vehicle *v)
03916 {
03917   Vehicle *first = v->First();
03918 
03919   /* Go to the last wagon and delete the link pointing there
03920    * *u is then the one-before-last wagon, and *v the last
03921    * one which will physicially be removed */
03922   Vehicle *u = v;
03923   for (; v->Next() != NULL; v = v->Next()) u = v;
03924   u->SetNext(NULL);
03925 
03926   if (first != v) {
03927     /* Recalculate cached train properties */
03928     TrainConsistChanged(first, false);
03929     /* Update the depot window if the first vehicle is in depot -
03930      * if v == first, then it is updated in PreDestructor() */
03931     if (first->u.rail.track == TRACK_BIT_DEPOT) {
03932       InvalidateWindow(WC_VEHICLE_DEPOT, first->tile);
03933     }
03934   }
03935 
03936   /* 'v' shouldn't be accessed after it has been deleted */
03937   TrackBits trackbits = v->u.rail.track;
03938   TileIndex tile = v->tile;
03939   Owner owner = v->owner;
03940 
03941   delete v;
03942   v = NULL; // make sure nobody will try to read 'v' anymore
03943 
03944   if ((trackbits & TRACK_BIT_WORMHOLE) == TRACK_BIT_WORMHOLE) {
03945     /* Vehicle is inside a wormhole, v->u.rail.track contains no useful value then. */
03946     trackbits |= DiagDirToDiagTrackBits(GetTunnelBridgeDirection(tile));
03947   }
03948 
03949   Track track = TrackBitsToTrack(trackbits);
03950   if (HasReservedTracks(tile, trackbits)) {
03951     UnreserveRailTrack(tile, track);
03952 
03953     /* If there are still crashed vehicles on the tile, give the track reservation to them */
03954     TrackBits remaining_trackbits = TRACK_BIT_NONE;
03955     FindVehicleOnPos(tile, &remaining_trackbits, CollectTrackbitsFromCrashedVehiclesEnum);
03956 
03957     /* It is important that these two are the first in the loop, as reservation cannot deal with every trackbit combination */
03958     assert(TRACK_BEGIN == TRACK_X && TRACK_Y == TRACK_BEGIN + 1);
03959     for (Track t = TRACK_BEGIN; t < TRACK_END; t++) {
03960       if (HasBit(remaining_trackbits, t)) {
03961         TryReserveRailTrack(tile, t);
03962       }
03963     }
03964   }
03965 
03966   /* check if the wagon was on a road/rail-crossing */
03967   if (IsLevelCrossingTile(tile)) UpdateLevelCrossing(tile);
03968 
03969   /* Update signals */
03970   if (IsTileType(tile, MP_TUNNELBRIDGE) || IsRailDepotTile(tile)) {
03971     UpdateSignalsOnSegment(tile, INVALID_DIAGDIR, owner);
03972   } else {
03973     SetSignalsOnBothDir(tile, track, owner);
03974   }
03975 }
03976 
03977 static void ChangeTrainDirRandomly(Vehicle *v)
03978 {
03979   static const DirDiff delta[] = {
03980     DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
03981   };
03982 
03983   do {
03984     /* We don't need to twist around vehicles if they're not visible */
03985     if (!(v->vehstatus & VS_HIDDEN)) {
03986       v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
03987       v->UpdateDeltaXY(v->direction);
03988       v->cur_image = v->GetImage(v->direction);
03989       /* Refrain from updating the z position of the vehicle when on
03990        * a bridge, because AfterSetTrainPos will put the vehicle under
03991        * the bridge in that case */
03992       if (v->u.rail.track != TRACK_BIT_WORMHOLE) AfterSetTrainPos(v, false);
03993     }
03994   } while ((v = v->Next()) != NULL);
03995 }
03996 
03997 static void HandleCrashedTrain(Vehicle *v)
03998 {
03999   int state = ++v->u.rail.crash_anim_pos;
04000 
04001   if (state == 4 && !(v->vehstatus & VS_HIDDEN)) {
04002     CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
04003   }
04004 
04005   uint32 r;
04006   if (state <= 200 && Chance16R(1, 7, r)) {
04007     int index = (r * 10 >> 16);
04008 
04009     Vehicle *u = v;
04010     do {
04011       if (--index < 0) {
04012         r = Random();
04013 
04014         CreateEffectVehicleRel(u,
04015           GB(r,  8, 3) + 2,
04016           GB(r, 16, 3) + 2,
04017           GB(r,  0, 3) + 5,
04018           EV_EXPLOSION_SMALL);
04019         break;
04020       }
04021     } while ((u = u->Next()) != NULL);
04022   }
04023 
04024   if (state <= 240 && !(v->tick_counter & 3)) ChangeTrainDirRandomly(v);
04025 
04026   if (state >= 4440 && !(v->tick_counter & 0x1F)) {
04027     DeleteLastWagon(v);
04028     InvalidateWindow(WC_REPLACE_VEHICLE, (v->group_id << 16) | VEH_TRAIN);
04029   }
04030 }
04031 
04032 static void HandleBrokenTrain(Vehicle *v)
04033 {
04034   if (v->breakdown_ctr != 1) {
04035     v->breakdown_ctr = 1;
04036     v->cur_speed = 0;
04037 
04038     if (v->breakdowns_since_last_service != 255)
04039       v->breakdowns_since_last_service++;
04040 
04041     InvalidateWindow(WC_VEHICLE_VIEW, v->index);
04042     InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
04043 
04044     if (!PlayVehicleSound(v, VSE_BREAKDOWN)) {
04045       SndPlayVehicleFx((_settings_game.game_creation.landscape != LT_TOYLAND) ?
04046         SND_10_TRAIN_BREAKDOWN : SND_3A_COMEDY_BREAKDOWN_2, v);
04047     }
04048 
04049     if (!(v->vehstatus & VS_HIDDEN)) {
04050       Vehicle *u = CreateEffectVehicleRel(v, 4, 4, 5, EV_BREAKDOWN_SMOKE);
04051       if (u != NULL) u->u.effect.animation_state = v->breakdown_delay * 2;
04052     }
04053   }
04054 
04055   if (!(v->tick_counter & 3)) {
04056     if (!--v->breakdown_delay) {
04057       v->breakdown_ctr = 0;
04058       InvalidateWindow(WC_VEHICLE_VIEW, v->index);
04059     }
04060   }
04061 }
04062 
04064 static const uint16 _breakdown_speeds[16] = {
04065   225, 210, 195, 180, 165, 150, 135, 120, 105, 90, 75, 60, 45, 30, 15, 15
04066 };
04067 
04068 
04076 static bool TrainApproachingLineEnd(Vehicle *v, bool signal)
04077 {
04078   /* Calc position within the current tile */
04079   uint x = v->x_pos & 0xF;
04080   uint y = v->y_pos & 0xF;
04081 
04082   /* for diagonal directions, 'x' will be 0..15 -
04083    * for other directions, it will be 1, 3, 5, ..., 15 */
04084   switch (v->direction) {
04085     case DIR_N : x = ~x + ~y + 25; break;
04086     case DIR_NW: x = y;            // FALLTHROUGH
04087     case DIR_NE: x = ~x + 16;      break;
04088     case DIR_E : x = ~x + y + 9;   break;
04089     case DIR_SE: x = y;            break;
04090     case DIR_S : x = x + y - 7;    break;
04091     case DIR_W : x = ~y + x + 9;   break;
04092     default: break;
04093   }
04094 
04095   /* do not reverse when approaching red signal */
04096   if (!signal && x + (v->u.rail.cached_veh_length + 1) / 2 >= TILE_SIZE) {
04097     /* we are too near the tile end, reverse now */
04098     v->cur_speed = 0;
04099     ReverseTrainDirection(v);
04100     return false;
04101   }
04102 
04103   /* slow down */
04104   v->vehstatus |= VS_TRAIN_SLOWING;
04105   uint16 break_speed = _breakdown_speeds[x & 0xF];
04106   if (break_speed < v->cur_speed) v->cur_speed = break_speed;
04107 
04108   return true;
04109 }
04110 
04111 
04117 static bool TrainCanLeaveTile(const Vehicle *v)
04118 {
04119   /* Exit if inside a tunnel/bridge or a depot */
04120   if (v->u.rail.track == TRACK_BIT_WORMHOLE || v->u.rail.track == TRACK_BIT_DEPOT) return false;
04121 
04122   TileIndex tile = v->tile;
04123 
04124   /* entering a tunnel/bridge? */
04125   if (IsTileType(tile, MP_TUNNELBRIDGE)) {
04126     DiagDirection dir = GetTunnelBridgeDirection(tile);
04127     if (DiagDirToDir(dir) == v->direction) return false;
04128   }
04129 
04130   /* entering a depot? */
04131   if (IsRailDepotTile(tile)) {
04132     DiagDirection dir = ReverseDiagDir(GetRailDepotDirection(tile));
04133     if (DiagDirToDir(dir) == v->direction) return false;
04134   }
04135 
04136   return true;
04137 }
04138 
04139 
04147 static TileIndex TrainApproachingCrossingTile(const Vehicle *v)
04148 {
04149   assert(IsFrontEngine(v));
04150   assert(!(v->vehstatus & VS_CRASHED));
04151 
04152   if (!TrainCanLeaveTile(v)) return INVALID_TILE;
04153 
04154   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
04155   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
04156 
04157   /* not a crossing || wrong axis || unusable rail (wrong type or owner) */
04158   if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
04159       !CheckCompatibleRail(v, tile)) {
04160     return INVALID_TILE;
04161   }
04162 
04163   return tile;
04164 }
04165 
04166 
04173 static bool TrainCheckIfLineEnds(Vehicle *v)
04174 {
04175   /* First, handle broken down train */
04176 
04177   int t = v->breakdown_ctr;
04178   if (t > 1) {
04179     v->vehstatus |= VS_TRAIN_SLOWING;
04180 
04181     uint16 break_speed = _breakdown_speeds[GB(~t, 4, 4)];
04182     if (break_speed < v->cur_speed) v->cur_speed = break_speed;
04183   } else {
04184     v->vehstatus &= ~VS_TRAIN_SLOWING;
04185   }
04186 
04187   if (!TrainCanLeaveTile(v)) return true;
04188 
04189   /* Determine the non-diagonal direction in which we will exit this tile */
04190   DiagDirection dir = TrainExitDir(v->direction, v->u.rail.track);
04191   /* Calculate next tile */
04192   TileIndex tile = v->tile + TileOffsByDiagDir(dir);
04193 
04194   /* Determine the track status on the next tile */
04195   TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_RAIL, 0, ReverseDiagDir(dir));
04196   TrackdirBits reachable_trackdirs = DiagdirReachesTrackdirs(dir);
04197 
04198   TrackdirBits trackdirbits = TrackStatusToTrackdirBits(ts) & reachable_trackdirs;
04199   TrackdirBits red_signals = TrackStatusToRedSignals(ts) & reachable_trackdirs;
04200 
04201   /* We are sure the train is not entering a depot, it is detected above */
04202 
04203   /* mask unreachable track bits if we are forbidden to do 90deg turns */
04204   TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
04205   if (_settings_game.pf.pathfinder_for_trains != VPF_NTP && _settings_game.pf.forbid_90_deg) {
04206     bits &= ~TrackCrossesTracks(FindFirstTrack(v->u.rail.track));
04207   }
04208 
04209   /* no suitable trackbits at all || unusable rail (wrong type or owner) */
04210   if (bits == TRACK_BIT_NONE || !CheckCompatibleRail(v, tile)) {
04211     return TrainApproachingLineEnd(v, false);
04212   }
04213 
04214   /* approaching red signal */
04215   if ((trackdirbits & red_signals) != 0) return TrainApproachingLineEnd(v, true);
04216 
04217   /* approaching a rail/road crossing? then make it red */
04218   if (IsLevelCrossingTile(tile)) MaybeBarCrossingWithSound(tile);
04219 
04220   return true;
04221 }
04222 
04223 
04224 static void TrainLocoHandler(Vehicle *v, bool mode)
04225 {
04226   /* train has crashed? */
04227   if (v->vehstatus & VS_CRASHED) {
04228     if (!mode) HandleCrashedTrain(v);
04229     return;
04230   }
04231 
04232   if (v->u.rail.force_proceed != 0) {
04233     v->u.rail.force_proceed--;
04234     ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
04235     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04236   }
04237 
04238   /* train is broken down? */
04239   if (v->breakdown_ctr != 0) {
04240     if (v->breakdown_ctr <= 2) {
04241       HandleBrokenTrain(v);
04242       return;
04243     }
04244     if (!v->current_order.IsType(OT_LOADING)) v->breakdown_ctr--;
04245   }
04246 
04247   if (HasBit(v->u.rail.flags, VRF_REVERSING) && v->cur_speed == 0) {
04248     ReverseTrainDirection(v);
04249   }
04250 
04251   /* exit if train is stopped */
04252   if (v->vehstatus & VS_STOPPED && v->cur_speed == 0) return;
04253 
04254   bool valid_order = v->current_order.IsValid() && v->current_order.GetType() != OT_CONDITIONAL;
04255   if (ProcessOrders(v) && CheckReverseTrain(v)) {
04256     v->load_unload_time_rem = 0;
04257     v->cur_speed = 0;
04258     v->subspeed = 0;
04259     ReverseTrainDirection(v);
04260     return;
04261   }
04262 
04263   v->HandleLoading(mode);
04264 
04265   if (v->current_order.IsType(OT_LOADING)) return;
04266 
04267   if (CheckTrainStayInDepot(v)) return;
04268 
04269   if (!mode) HandleLocomotiveSmokeCloud(v);
04270 
04271   /* We had no order but have an order now, do look ahead. */
04272   if (!valid_order && v->current_order.IsValid()) {
04273     CheckNextTrainTile(v);
04274   }
04275 
04276   /* Handle stuck trains. */
04277   if (!mode && HasBit(v->u.rail.flags, VRF_TRAIN_STUCK)) {
04278     ++v->load_unload_time_rem;
04279 
04280     /* Should we try reversing this tick if still stuck? */
04281     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;
04282 
04283     if (!turn_around && v->load_unload_time_rem % _settings_game.pf.path_backoff_interval != 0 && v->u.rail.force_proceed == 0) return;
04284     if (!TryPathReserve(v)) {
04285       /* Still stuck. */
04286       if (turn_around) ReverseTrainDirection(v);
04287 
04288       if (HasBit(v->u.rail.flags, VRF_TRAIN_STUCK) && v->load_unload_time_rem > 2 * _settings_game.pf.wait_for_pbs_path * DAY_TICKS) {
04289         /* Show message to player. */
04290         if (_settings_client.gui.lost_train_warn && v->owner == _local_company) {
04291           SetDParam(0, v->index);
04292           AddNewsItem(
04293             STR_TRAIN_IS_STUCK,
04294             NS_ADVICE,
04295             v->index,
04296             0);
04297         }
04298         v->load_unload_time_rem = 0;
04299       }
04300       /* Exit if force proceed not pressed, else reset stuck flag anyway. */
04301       if (v->u.rail.force_proceed == 0) return;
04302       ClrBit(v->u.rail.flags, VRF_TRAIN_STUCK);
04303       v->load_unload_time_rem = 0;
04304       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04305     }
04306   }
04307 
04308   if (v->current_order.IsType(OT_LEAVESTATION)) {
04309     v->current_order.Free();
04310     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04311     return;
04312   }
04313 
04314   int j = UpdateTrainSpeed(v);
04315 
04316   /* we need to invalidate the widget if we are stopping from 'Stopping 0 km/h' to 'Stopped' */
04317   if (v->cur_speed == 0 && v->u.rail.last_speed == 0 && v->vehstatus & VS_STOPPED) {
04318     InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04319   }
04320 
04321   int adv_spd = (v->direction & 1) ? 192 : 256;
04322   if (j < adv_spd) {
04323     /* if the vehicle has speed 0, update the last_speed field. */
04324     if (v->cur_speed == 0) SetLastSpeed(v, v->cur_speed);
04325   } else {
04326     TrainCheckIfLineEnds(v);
04327     /* Loop until the train has finished moving. */
04328     do {
04329       j -= adv_spd;
04330       TrainController(v, NULL);
04331       /* Don't continue to move if the train crashed. */
04332       if (CheckTrainCollision(v)) break;
04333       /* 192 spd used for going straight, 256 for going diagonally. */
04334       adv_spd = (v->direction & 1) ? 192 : 256;
04335     } while (j >= adv_spd);
04336     SetLastSpeed(v, v->cur_speed);
04337   }
04338 
04339   for (Vehicle *u = v; u != NULL; u = u->Next()) {
04340     if ((u->vehstatus & VS_HIDDEN) != 0) continue;
04341 
04342     uint16 old_image = u->cur_image;
04343     u->cur_image = u->GetImage(u->direction);
04344     if (old_image != u->cur_image) VehicleMove(u, true);
04345   }
04346 
04347   if (v->progress == 0) v->progress = j; // Save unused spd for next time, if TrainController didn't set progress
04348 }
04349 
04350 
04351 
04352 Money Train::GetRunningCost() const
04353 {
04354   Money cost = 0;
04355   const Vehicle *v = this;
04356 
04357   do {
04358     const RailVehicleInfo *rvi = RailVehInfo(v->engine_type);
04359 
04360     byte cost_factor = GetVehicleProperty(v, 0x0D, rvi->running_cost);
04361     if (cost_factor == 0) continue;
04362 
04363     /* Halve running cost for multiheaded parts */
04364     if (IsMultiheaded(v)) cost_factor /= 2;
04365 
04366     cost += cost_factor * GetPriceByIndex(rvi->running_cost_class);
04367   } while ((v = GetNextVehicle(v)) != NULL);
04368 
04369   return cost;
04370 }
04371 
04372 
04373 void Train::Tick()
04374 {
04375   if (_age_cargo_skip_counter == 0) this->cargo.AgeCargo();
04376 
04377   this->tick_counter++;
04378 
04379   if (IsFrontEngine(this)) {
04380     if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;
04381     this->current_order_time++;
04382 
04383     TrainLocoHandler(this, false);
04384 
04385     /* make sure vehicle wasn't deleted. */
04386     if (this->type == VEH_TRAIN && IsFrontEngine(this))
04387       TrainLocoHandler(this, true);
04388   } else if (IsFreeWagon(this) && HASBITS(this->vehstatus, VS_CRASHED)) {
04389     /* Delete flooded standalone wagon chain */
04390     if (++this->u.rail.crash_anim_pos >= 4400) delete this;
04391   }
04392 }
04393 
04394 static void CheckIfTrainNeedsService(Vehicle *v)
04395 {
04396   static const uint MAX_ACCEPTABLE_DEPOT_DIST = 16;
04397 
04398   if (_settings_game.vehicle.servint_trains == 0 || !v->NeedsAutomaticServicing()) return;
04399   if (v->IsInDepot()) {
04400     VehicleServiceInDepot(v);
04401     return;
04402   }
04403 
04404   TrainFindDepotData tfdd = FindClosestTrainDepot(v, MAX_ACCEPTABLE_DEPOT_DIST);
04405   /* Only go to the depot if it is not too far out of our way. */
04406   if (tfdd.best_length == UINT_MAX || tfdd.best_length > MAX_ACCEPTABLE_DEPOT_DIST) {
04407     if (v->current_order.IsType(OT_GOTO_DEPOT)) {
04408       /* If we were already heading for a depot but it has
04409        * suddenly moved farther away, we continue our normal
04410        * schedule? */
04411       v->current_order.MakeDummy();
04412       InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04413     }
04414     return;
04415   }
04416 
04417   const Depot *depot = GetDepotByTile(tfdd.tile);
04418 
04419   if (v->current_order.IsType(OT_GOTO_DEPOT) &&
04420       v->current_order.GetDestination() != depot->index &&
04421       !Chance16(3, 16)) {
04422     return;
04423   }
04424 
04425   v->current_order.MakeGoToDepot(depot->index, ODTFB_SERVICE);
04426   v->dest_tile = tfdd.tile;
04427   InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);
04428 }
04429 
04430 void Train::OnNewDay()
04431 {
04432   if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
04433 
04434   if (IsFrontEngine(this)) {
04435     CheckVehicleBreakdown(this);
04436     AgeVehicle(this);
04437 
04438     CheckIfTrainNeedsService(this);
04439 
04440     CheckOrders(this);
04441 
04442     /* update destination */
04443     if (this->current_order.IsType(OT_GOTO_STATION)) {
04444       TileIndex tile = GetStation(this->current_order.GetDestination())->train_tile;
04445       if (tile != INVALID_TILE) this->dest_tile = tile;
04446     }
04447 
04448     if (this->running_ticks != 0) {
04449       /* running costs */
04450       CommandCost cost(EXPENSES_TRAIN_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR  * DAY_TICKS));
04451 
04452       this->profit_this_year -= cost.GetCost();
04453       this->running_ticks = 0;
04454 
04455       SubtractMoneyFromCompanyFract(this->owner, cost);
04456 
04457       InvalidateWindow(WC_VEHICLE_DETAILS, this->index);
04458       InvalidateWindowClasses(WC_TRAINS_LIST);
04459     }
04460   } else if (IsTrainEngine(this)) {
04461     /* Also age engines that aren't front engines */
04462     AgeVehicle(this);
04463   }
04464 }
04465 
04466 void InitializeTrains()
04467 {
04468   _age_cargo_skip_counter = 1;
04469 }

Generated on Sun Mar 15 22:49:51 2009 for openttd by  doxygen 1.5.6