# autoreplace_cmd.cpp

Go to the documentation of this file.

    00001 /* $Id$ */
    00002
    00003 /*
    00004  * This file is part of OpenTTD.
    00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
    00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
    00008  */
    00009
    00012 #include "stdafx.h"
    00013 #include "company_func.h"
    00014 #include "train.h"
    00015 #include "rail.h"
    00016 #include "command_func.h"
    00017 #include "engine_base.h"
    00018 #include "engine_func.h"
    00019 #include "vehicle_func.h"
    00020 #include "functions.h"
    00021 #include "autoreplace_func.h"
    00022 #include "articulated_vehicles.h"
    00023
    00024 #include "table/strings.h"
    00025
    00026 extern void ChangeVehicleViewports(VehicleID from_index, VehicleID to_index);
    00027 extern void ChangeVehicleNews(VehicleID from_index, VehicleID to_index);
    00028 extern void ChangeVehicleViewWindow(VehicleID from_index, VehicleID to_index);
    00029
    00036 static bool EnginesHaveCargoInCommon(EngineID engine_a, EngineID engine_b)
    00037 {
    00038   uint32 available_cargos_a = GetUnionOfArticulatedRefitMasks(engine_a, true);
    00039   uint32 available_cargos_b = GetUnionOfArticulatedRefitMasks(engine_b, true);
    00040   return (available_cargos_a == 0 || available_cargos_b == 0 || (available_cargos_a & available_cargos_b) != 0);
    00041 }
    00042
    00050 bool CheckAutoreplaceValidity(EngineID from, EngineID to, CompanyID company)
    00051 {
    00052   /* First we make sure that it's a valid type the user requested
    00053    * check that it's an engine that is in the engine array */
    00054   if (!Engine::IsValidID(from) || !Engine::IsValidID(to)) return false;
    00055
    00056   /* we can't replace an engine into itself (that would be autorenew) */
    00057   if (from == to) return false;
    00058
    00059   const Engine *e_from = Engine::Get(from);
    00060   const Engine *e_to = Engine::Get(to);
    00061   VehicleType type = e_from->type;
    00062
    00063   /* check that the new vehicle type is available to the company and its type is the same as the original one */
    00064   if (!IsEngineBuildable(to, type, company)) return false;
    00065
    00066   switch (type) {
    00067     case VEH_TRAIN: {
    00068       /* make sure the railtypes are compatible */
    00069       if ((GetRailTypeInfo(e_from->u.rail.railtype)->compatible_railtypes & GetRailTypeInfo(e_to->u.rail.railtype)->compatible_railtypes) == 0) return false;
    00070
    00071       /* make sure we do not replace wagons with engines or vise versa */
    00072       if ((e_from->u.rail.railveh_type == RAILVEH_WAGON) != (e_to->u.rail.railveh_type == RAILVEH_WAGON)) return false;
    00073       break;
    00074     }
    00075
    00076     case VEH_ROAD:
    00077       /* make sure that we do not replace a tram with a normal road vehicles or vise versa */
    00078       if (HasBit(e_from->info.misc_flags, EF_ROAD_TRAM) != HasBit(e_to->info.misc_flags, EF_ROAD_TRAM)) return false;
    00079       break;
    00080
    00081     case VEH_AIRCRAFT:
    00082       /* make sure that we do not replace a plane with a helicopter or vise versa */
    00083       if ((e_from->u.air.subtype & AIR_CTOL) != (e_to->u.air.subtype & AIR_CTOL)) return false;
    00084       break;
    00085
    00086     default: break;
    00087   }
    00088
    00089   /* the engines needs to be able to carry the same cargo */
    00090   return EnginesHaveCargoInCommon(from, to);
    00091 }
    00092
    00098 static void TransferCargo(Vehicle *old_veh, Vehicle *new_head, bool part_of_chain)
    00099 {
    00100   assert(!part_of_chain || new_head->IsPrimaryVehicle());
    00101   /* Loop through source parts */
    00102   for (Vehicle *src = old_veh; src != NULL; src = src->Next()) {
    00103     if (!part_of_chain && src->type == VEH_TRAIN && src != old_veh && src != Train::From(old_veh)->other_multiheaded_part && !Train::From(src)->IsArticulatedPart()) {
    00104       /* Skip vehicles, which do not belong to old_veh */
    00105       src = Train::From(src)->GetLastEnginePart();
    00106       continue;
    00107     }
    00108     if (src->cargo_type >= NUM_CARGO || src->cargo.Count() == 0) continue;
    00109
    00110     /* Find free space in the new chain */
    00111     for (Vehicle *dest = new_head; dest != NULL && src->cargo.Count() > 0; dest = dest->Next()) {
    00112       if (!part_of_chain && dest->type == VEH_TRAIN && dest != new_head && dest != Train::From(new_head)->other_multiheaded_part && !Train::From(dest)->IsArticulatedPart()) {
    00113         /* Skip vehicles, which do not belong to new_head */
    00114         dest = Train::From(dest)->GetLastEnginePart();
    00115         continue;
    00116       }
    00117       if (dest->cargo_type != src->cargo_type) continue;
    00118
    00119       uint amount = min(src->cargo.Count(), dest->cargo_cap - dest->cargo.Count());
    00120       if (amount <= 0) continue;
    00121
    00122       src->cargo.MoveTo(&dest->cargo, amount, VehicleCargoList::MTA_UNLOAD, NULL);
    00123     }
    00124   }
    00125
    00126   /* Update train weight etc., the old vehicle will be sold anyway */
    00127   if (part_of_chain && new_head->type == VEH_TRAIN) TrainConsistChanged(Train::From(new_head), true);
    00128 }
    00129
    00136 static bool VerifyAutoreplaceRefitForOrders(const Vehicle *v, EngineID engine_type)
    00137 {
    00138   const Order *o;
    00139   const Vehicle *u;
    00140
    00141   uint32 union_refit_mask_a = GetUnionOfArticulatedRefitMasks(v->engine_type, false);
    00142   uint32 union_refit_mask_b = GetUnionOfArticulatedRefitMasks(engine_type, false);
    00143
    00144   if (v->type == VEH_TRAIN) {
    00145     u = v->First();
    00146   } else {
    00147     u = v;
    00148   }
    00149
    00150   FOR_VEHICLE_ORDERS(u, o) {
    00151     if (!o->IsRefit()) continue;
    00152     CargoID cargo_type = o->GetRefitCargo();
    00153
    00154     if (!HasBit(union_refit_mask_a, cargo_type)) continue;
    00155     if (!HasBit(union_refit_mask_b, cargo_type)) return false;
    00156   }
    00157
    00158   return true;
    00159 }
    00160
    00170 static CargoID GetNewCargoTypeForReplace(Vehicle *v, EngineID engine_type, bool part_of_chain)
    00171 {
    00172   CargoID cargo_type;
    00173   uint32 available_cargo_types, union_mask;
    00174   GetArticulatedRefitMasks(engine_type, true, &union_mask, &available_cargo_types);
    00175
    00176   if (union_mask == 0) return CT_NO_REFIT; // Don't try to refit an engine with no cargo capacity
    00177
    00178   if (IsArticulatedVehicleCarryingDifferentCargos(v, &cargo_type)) return CT_INVALID; // We cannot refit to mixed cargos in an automated way
    00179
    00180   if (cargo_type == CT_INVALID) {
    00181     if (v->type != VEH_TRAIN) return CT_NO_REFIT; // If the vehicle does not carry anything at all, every replacement is fine.
    00182
    00183     if (!part_of_chain) return CT_NO_REFIT;
    00184
    00185     /* the old engine didn't have cargo capacity, but the new one does
    00186      * now we will figure out what cargo the train is carrying and refit to fit this */
    00187
    00188     for (v = v->First(); v != NULL; v = v->Next()) {
    00189       if (v->cargo_cap == 0) continue;
    00190       /* Now we found a cargo type being carried on the train and we will see if it is possible to carry to this one */
    00191       if (HasBit(available_cargo_types, v->cargo_type)) {
    00192         /* Do we have to refit the vehicle, or is it already carrying the right cargo? */
    00193         CargoArray default_capacity = GetCapacityOfArticulatedParts(engine_type);
    00194         for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
    00195           if (cid != v->cargo_type && default_capacity[cid] > 0) return v->cargo_type;
    00196         }
    00197
    00198         return CT_NO_REFIT;
    00199       }
    00200     }
    00201
    00202     return CT_NO_REFIT; // We failed to find a cargo type on the old vehicle and we will not refit the new one
    00203   } else {
    00204     if (!HasBit(available_cargo_types, cargo_type)) return CT_INVALID; // We can't refit the vehicle to carry the cargo we want
    00205
    00206     if (part_of_chain && !VerifyAutoreplaceRefitForOrders(v, engine_type)) return CT_INVALID; // Some refit orders lose their effect
    00207
    00208     /* Do we have to refit the vehicle, or is it already carrying the right cargo? */
    00209     CargoArray default_capacity = GetCapacityOfArticulatedParts(engine_type);
    00210     for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
    00211       if (cid != cargo_type && default_capacity[cid] > 0) return cargo_type;
    00212     }
    00213
    00214     return CT_NO_REFIT;
    00215   }
    00216 }
    00217
    00223 static EngineID GetNewEngineType(const Vehicle *v, const Company *c)
    00224 {
    00225   assert(v->type != VEH_TRAIN || !Train::From(v)->IsArticulatedPart());
    00226
    00227   if (v->type == VEH_TRAIN && Train::From(v)->IsRearDualheaded()) {
    00228     /* we build the rear ends of multiheaded trains with the front ones */
    00229     return INVALID_ENGINE;
    00230   }
    00231
    00232   EngineID e = EngineReplacementForCompany(c, v->engine_type, v->group_id);
    00233
    00234   if (e != INVALID_ENGINE && IsEngineBuildable(e, v->type, _current_company)) {
    00235     return e;
    00236   }
    00237
    00238   if (v->NeedsAutorenewing(c) && // replace if engine is too old
    00239       IsEngineBuildable(v->engine_type, v->type, _current_company)) { // engine can still be build
    00240     return v->engine_type;
    00241   }
    00242
    00243   return INVALID_ENGINE;
    00244 }
    00245
    00253 static CommandCost BuildReplacementVehicle(Vehicle *old_veh, Vehicle **new_vehicle, bool part_of_chain)
    00254 {
    00255   *new_vehicle = NULL;
    00256
    00257   /* Shall the vehicle be replaced? */
    00258   const Company *c = Company::Get(_current_company);
    00259   EngineID e = GetNewEngineType(old_veh, c);
    00260   if (e == INVALID_ENGINE) return CommandCost(); // neither autoreplace is set, nor autorenew is triggered
    00261
    00262   /* Does it need to be refitted */
    00263   CargoID refit_cargo = GetNewCargoTypeForReplace(old_veh, e, part_of_chain);
    00264   if (refit_cargo == CT_INVALID) return CommandCost(); // incompatible cargos
    00265
    00266   /* Build the new vehicle */
    00267   CommandCost cost = DoCommand(old_veh->tile, e, 0, DC_EXEC | DC_AUTOREPLACE, GetCmdBuildVeh(old_veh));
    00268   if (cost.Failed()) return cost;
    00269
    00270   Vehicle *new_veh = Vehicle::Get(_new_vehicle_id);
    00271   *new_vehicle = new_veh;
    00272
    00273   /* Refit the vehicle if needed */
    00274   byte subtype = GetBestFittingSubType(old_veh, new_veh);
    00275   /* If the subtype isn't zero and the refit cargo is not set,
    00276    * we're better off setting the refit cargo too. */
    00277   if (subtype != 0 && refit_cargo == CT_NO_REFIT) refit_cargo = old_veh->cargo_type;
    00278
    00279   if (refit_cargo != CT_NO_REFIT) {
    00280     cost.AddCost(DoCommand(0, new_veh->index, refit_cargo | (subtype << 8), DC_EXEC, GetCmdRefitVeh(new_veh)));
    00281     assert(cost.Succeeded()); // This should be ensured by GetNewCargoTypeForReplace()
    00282   }
    00283
    00284   /* Try to reverse the vehicle, but do not care if it fails as the new type might not be reversible */
    00285   if (new_veh->type == VEH_TRAIN && HasBit(Train::From(old_veh)->flags, VRF_REVERSE_DIRECTION)) {
    00286     DoCommand(0, new_veh->index, true, DC_EXEC, CMD_REVERSE_TRAIN_DIRECTION);
    00287   }
    00288
    00289   return cost;
    00290 }
    00291
    00297 static inline CommandCost StartStopVehicle(const Vehicle *v, bool evaluate_callback)
    00298 {
    00299   return DoCommand(0, v->index, evaluate_callback ? 1 : 0, DC_EXEC | DC_AUTOREPLACE, CMD_START_STOP_VEHICLE);
    00300 }
    00301
    00309 static inline CommandCost MoveVehicle(const Vehicle *v, const Vehicle *after, DoCommandFlag flags, bool whole_chain)
    00310 {
    00311   return DoCommand(0, v->index | (after != NULL ? after->index : INVALID_VEHICLE) << 16, whole_chain ? 1 : 0, flags, CMD_MOVE_RAIL_VEHICLE);
    00312 }
    00313
    00319 static CommandCost CopyHeadSpecificThings(Vehicle *old_head, Vehicle *new_head, DoCommandFlag flags)
    00320 {
    00321   CommandCost cost = CommandCost();
    00322
    00323   /* Share orders */
    00324   if (cost.Succeeded() && old_head != new_head) cost.AddCost(DoCommand(0, (old_head->index << 16) | new_head->index, CO_SHARE, DC_EXEC, CMD_CLONE_ORDER));
    00325
    00326   /* Copy group membership */
    00327   if (cost.Succeeded() && old_head != new_head) cost.AddCost(DoCommand(0, old_head->group_id, new_head->index, DC_EXEC, CMD_ADD_VEHICLE_GROUP));
    00328
    00329   /* Perform start/stop check whether the new vehicle suits newgrf restrictions etc. */
    00330   if (cost.Succeeded()) {
    00331     /* Start the vehicle, might be denied by certain things */
    00332     assert((new_head->vehstatus & VS_STOPPED) != 0);
    00333     cost.AddCost(StartStopVehicle(new_head, true));
    00334
    00335     /* Stop the vehicle again, but do not care about evil newgrfs allowing starting but not stopping :p */
    00336     if (cost.Succeeded()) cost.AddCost(StartStopVehicle(new_head, false));
    00337   }
    00338
    00339   /* Last do those things which do never fail (resp. we do not care about), but which are not undo-able */
    00340   if (cost.Succeeded() && old_head != new_head && (flags & DC_EXEC) != 0) {
    00341     /* Copy vehicle name */
    00342     if (old_head->name != NULL) {
    00343       DoCommand(0, new_head->index, 0, DC_EXEC | DC_AUTOREPLACE, CMD_RENAME_VEHICLE, old_head->name);
    00344     }
    00345
    00346     /* Copy other things which cannot be copied by a command and which shall not stay resetted from the build vehicle command */
    00347     new_head->CopyVehicleConfigAndStatistics(old_head);
    00348
    00349     /* Switch vehicle windows/news to the new vehicle, so they are not closed/deleted when the old vehicle is sold */
    00350     ChangeVehicleViewports(old_head->index, new_head->index);
    00351     ChangeVehicleViewWindow(old_head->index, new_head->index);
    00352     ChangeVehicleNews(old_head->index, new_head->index);
    00353   }
    00354
    00355   return cost;
    00356 }
    00357
    00364 static CommandCost ReplaceFreeUnit(Vehicle **single_unit, DoCommandFlag flags, bool *nothing_to_do)
    00365 {
    00366   Train *old_v = Train::From(*single_unit);
    00367   assert(!old_v->IsArticulatedPart() && !old_v->IsRearDualheaded());
    00368
    00369   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
    00370
    00371   /* Build and refit replacement vehicle */
    00372   Vehicle *new_v = NULL;
    00373   cost.AddCost(BuildReplacementVehicle(old_v, &new_v, false));
    00374
    00375   /* Was a new vehicle constructed? */
    00376   if (cost.Succeeded() && new_v != NULL) {
    00377     *nothing_to_do = false;
    00378
    00379     if ((flags & DC_EXEC) != 0) {
    00380       /* Move the new vehicle behind the old */
    00381       MoveVehicle(new_v, old_v, DC_EXEC, false);
    00382
    00383       /* Take over cargo
    00384        * Note: We do only transfer cargo from the old to the new vehicle.
    00385        *       I.e. we do not transfer remaining cargo to other vehicles.
    00386        *       Else you would also need to consider moving cargo to other free chains,
    00387        *       or doing the same in ReplaceChain(), which would be quite troublesome.
    00388        */
    00389       TransferCargo(old_v, new_v, false);
    00390
    00391       *single_unit = new_v;
    00392     }
    00393
    00394     /* Sell the old vehicle */
    00395     cost.AddCost(DoCommand(0, old_v->index, 0, flags, GetCmdSellVeh(old_v)));
    00396
    00397     /* If we are not in DC_EXEC undo everything */
    00398     if ((flags & DC_EXEC) == 0) {
    00399       DoCommand(0, new_v->index, 0, DC_EXEC, GetCmdSellVeh(new_v));
    00400     }
    00401   }
    00402
    00403   return cost;
    00404 }
    00405
    00413 static CommandCost ReplaceChain(Vehicle **chain, DoCommandFlag flags, bool wagon_removal, bool *nothing_to_do)
    00414 {
    00415   Vehicle *old_head = *chain;
    00416   assert(old_head->IsPrimaryVehicle());
    00417
    00418   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
    00419
    00420   if (old_head->type == VEH_TRAIN) {
    00421     /* Store the length of the old vehicle chain, rounded up to whole tiles */
    00422     uint16 old_total_length = (Train::From(old_head)->tcache.cached_total_length + TILE_SIZE - 1) / TILE_SIZE * TILE_SIZE;
    00423
    00424     int num_units = 0;
    00425     for (Train *w = Train::From(old_head); w != NULL; w = w->GetNextUnit()) num_units++;
    00426
    00427     Train **old_vehs = CallocT<Train *>(num_units);
    00428     Train **new_vehs = CallocT<Train *>(num_units);
    00429     Money *new_costs = MallocT<Money>(num_units);
    00430
    00431     /* Collect vehicles and build replacements
    00432      * Note: The replacement vehicles can only successfully build as long as the old vehicles are still in their chain */
    00433     int i;
    00434     Train *w;
    00435     for (w = Train::From(old_head), i = 0; w != NULL; w = w->GetNextUnit(), i++) {
    00436       assert(i < num_units);
    00437       old_vehs[i] = w;
    00438
    00439       CommandCost ret = BuildReplacementVehicle(old_vehs[i], (Vehicle**)&new_vehs[i], true);
    00440       cost.AddCost(ret);
    00441       if (cost.Failed()) break;
    00442
    00443       new_costs[i] = ret.GetCost();
    00444       if (new_vehs[i] != NULL) *nothing_to_do = false;
    00445     }
    00446     Train *new_head = (new_vehs[0] != NULL ? new_vehs[0] : old_vehs[0]);
    00447
    00448     /* Note: When autoreplace has already failed here, old_vehs[] is not completely initialized. But it is also not needed. */
    00449     if (cost.Succeeded()) {
    00450       /* Separate the head, so we can start constructing the new chain */
    00451       Train *second = Train::From(old_head)->GetNextUnit();
    00452       if (second != NULL) cost.AddCost(MoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true));
    00453
    00454       assert(Train::From(new_head)->GetNextUnit() == NULL);
    00455
    00456       /* Append engines to the new chain
    00457        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
    00458        * OTOH the vehicle attach callback is more expensive this way :s */
    00459       Train *last_engine = NULL;
    00460       if (cost.Succeeded()) {
    00461         for (int i = num_units - 1; i > 0; i--) {
    00462           Train *append = (new_vehs[i] != NULL ? new_vehs[i] : old_vehs[i]);
    00463
    00464           if (RailVehInfo(append->engine_type)->railveh_type == RAILVEH_WAGON) continue;
    00465
    00466           if (last_engine == NULL) last_engine = append;
    00467           cost.AddCost(MoveVehicle(append, new_head, DC_EXEC, false));
    00468           if (cost.Failed()) break;
    00469         }
    00470         if (last_engine == NULL) last_engine = new_head;
    00471       }
    00472
    00473       /* When wagon removal is enabled and the new engines without any wagons are already longer than the old, we have to fail */
    00474       if (cost.Succeeded() && wagon_removal && new_head->tcache.cached_total_length > old_total_length) cost = CommandCost(STR_ERROR_TRAIN_TOO_LONG_AFTER_REPLACEMENT);
    00475
    00476       /* Append/insert wagons into the new vehicle chain
    00477        * We do this from back to front, so we can stop when wagon removal or maximum train length (i.e. from mammoth-train setting) is triggered.
    00478        */
    00479       if (cost.Succeeded()) {
    00480         for (int i = num_units - 1; i > 0; i--) {
    00481           assert(last_engine != NULL);
    00482           Vehicle *append = (new_vehs[i] != NULL ? new_vehs[i] : old_vehs[i]);
    00483
    00484           if (RailVehInfo(append->engine_type)->railveh_type == RAILVEH_WAGON) {
    00485             /* Insert wagon after 'last_engine' */
    00486             CommandCost res = MoveVehicle(append, last_engine, DC_EXEC, false);
    00487
    00488             if (res.Succeeded() && wagon_removal && new_head->tcache.cached_total_length > old_total_length) {
    00489               MoveVehicle(append, NULL, DC_EXEC | DC_AUTOREPLACE, false);
    00490               break;
    00491             }
    00492
    00493             cost.AddCost(res);
    00494             if (cost.Failed()) break;
    00495           } else {
    00496             /* We have reached 'last_engine', continue with the next engine towards the front */
    00497             assert(append == last_engine);
    00498             last_engine = last_engine->GetPrevUnit();
    00499           }
    00500         }
    00501       }
    00502
    00503       /* Sell superfluous new vehicles that could not be inserted. */
    00504       if (cost.Succeeded() && wagon_removal) {
    00505         for (int i = 1; i < num_units; i++) {
    00506           Vehicle *wagon = new_vehs[i];
    00507           if (wagon == NULL) continue;
    00508           if (wagon->First() == new_head) break;
    00509
    00510           assert(RailVehInfo(wagon->engine_type)->railveh_type == RAILVEH_WAGON);
    00511
    00512           /* Sell wagon */
    00513           CommandCost ret = DoCommand(0, wagon->index, 0, DC_EXEC, GetCmdSellVeh(wagon));
    00514           assert(ret.Succeeded());
    00515           new_vehs[i] = NULL;
    00516
    00517           /* Revert the money subtraction when the vehicle was built.
    00518            * This value is different from the sell value, esp. because of refitting */
    00519           cost.AddCost(-new_costs[i]);
    00520         }
    00521       }
    00522
    00523       /* The new vehicle chain is constructed, now take over orders and everything... */
    00524       if (cost.Succeeded()) cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
    00525
    00526       if (cost.Succeeded()) {
    00527         /* Success ! */
    00528         if ((flags & DC_EXEC) != 0 && new_head != old_head) {
    00529           *chain = new_head;
    00530         }
    00531
    00532         /* Transfer cargo of old vehicles and sell them */
    00533         for (int i = 0; i < num_units; i++) {
    00534           Vehicle *w = old_vehs[i];
    00535           /* Is the vehicle again part of the new chain?
    00536            * Note: We cannot test 'new_vehs[i] != NULL' as wagon removal might cause to remove both */
    00537           if (w->First() == new_head) continue;
    00538
    00539           if ((flags & DC_EXEC) != 0) TransferCargo(w, new_head, true);
    00540
    00541           /* Sell the vehicle.
    00542            * Note: This might temporarly construct new trains, so use DC_AUTOREPLACE to prevent
    00543            *       it from failing due to engine limits. */
    00544           cost.AddCost(DoCommand(0, w->index, 0, flags | DC_AUTOREPLACE, GetCmdSellVeh(w)));
    00545           if ((flags & DC_EXEC) != 0) {
    00546             old_vehs[i] = NULL;
    00547             if (i == 0) old_head = NULL;
    00548           }
    00549         }
    00550       }
    00551
    00552       /* If we are not in DC_EXEC undo everything, i.e. rearrange old vehicles.
    00553        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
    00554        * Note: The vehicle attach callback is disabled here :) */
    00555       if ((flags & DC_EXEC) == 0) {
    00556         /* Separate the head, so we can reattach the old vehicles */
    00557         Train *second = Train::From(old_head)->GetNextUnit();
    00558         if (second != NULL) MoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true);
    00559
    00560         assert(Train::From(old_head)->GetNextUnit() == NULL);
    00561
    00562         for (int i = num_units - 1; i > 0; i--) {
    00563           CommandCost ret = MoveVehicle(old_vehs[i], old_head, DC_EXEC | DC_AUTOREPLACE, false);
    00564           assert(ret.Succeeded());
    00565         }
    00566       }
    00567     }
    00568
    00569     /* Finally undo buying of new vehicles */
    00570     if ((flags & DC_EXEC) == 0) {
    00571       for (int i = num_units - 1; i >= 0; i--) {
    00572         if (new_vehs[i] != NULL) {
    00573           DoCommand(0, new_vehs[i]->index, 0, DC_EXEC, GetCmdSellVeh(new_vehs[i]));
    00574           new_vehs[i] = NULL;
    00575         }
    00576       }
    00577     }
    00578
    00579     free(old_vehs);
    00580     free(new_vehs);
    00581     free(new_costs);
    00582   } else {
    00583     /* Build and refit replacement vehicle */
    00584     Vehicle *new_head = NULL;
    00585     cost.AddCost(BuildReplacementVehicle(old_head, &new_head, true));
    00586
    00587     /* Was a new vehicle constructed? */
    00588     if (cost.Succeeded() && new_head != NULL) {
    00589       *nothing_to_do = false;
    00590
    00591       /* The new vehicle is constructed, now take over orders and everything... */
    00592       cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
    00593
    00594       if (cost.Succeeded()) {
    00595         /* The new vehicle is constructed, now take over cargo */
    00596         if ((flags & DC_EXEC) != 0) {
    00597           TransferCargo(old_head, new_head, true);
    00598           *chain = new_head;
    00599         }
    00600
    00601         /* Sell the old vehicle */
    00602         cost.AddCost(DoCommand(0, old_head->index, 0, flags, GetCmdSellVeh(old_head)));
    00603       }
    00604
    00605       /* If we are not in DC_EXEC undo everything */
    00606       if ((flags & DC_EXEC) == 0) {
    00607         DoCommand(0, new_head->index, 0, DC_EXEC, GetCmdSellVeh(new_head));
    00608       }
    00609     }
    00610   }
    00611
    00612   return cost;
    00613 }
    00614
    00624 CommandCost CmdAutoreplaceVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
    00625 {
    00626   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
    00627   bool nothing_to_do = true;
    00628
    00629   Vehicle *v = Vehicle::GetIfValid(p1);
    00630   if (v == NULL) return CMD_ERROR;
    00631
    00632   if (!CheckOwnership(v->owner)) return CMD_ERROR;
    00633   if (!v->IsInDepot()) return CMD_ERROR;
    00634   if (v->vehstatus & VS_CRASHED) return CMD_ERROR;
    00635
    00636   bool free_wagon = false;
    00637   if (v->type == VEH_TRAIN) {
    00638     Train *t = Train::From(v);
    00639     if (t->IsArticulatedPart() || t->IsRearDualheaded()) return CMD_ERROR;
    00640     free_wagon = !t->IsFrontEngine();
    00641     if (free_wagon && t->First()->IsFrontEngine()) return CMD_ERROR;
    00642   } else {
    00643     if (!v->IsPrimaryVehicle()) return CMD_ERROR;
    00644   }
    00645
    00646   const Company *c = Company::Get(_current_company);
    00647   bool wagon_removal = c->settings.renew_keep_length;
    00648
    00649   /* Test whether any replacement is set, before issuing a whole lot of commands that would end in nothing changed */
    00650   Vehicle *w = v;
    00651   bool any_replacements = false;
    00652   while (w != NULL && !any_replacements) {
    00653     any_replacements = (GetNewEngineType(w, c) != INVALID_ENGINE);
    00654     w = (!free_wagon && w->type == VEH_TRAIN ? Train::From(w)->GetNextUnit() : NULL);
    00655   }
    00656
    00657   if (any_replacements) {
    00658     bool was_stopped = free_wagon || ((v->vehstatus & VS_STOPPED) != 0);
    00659
    00660     /* Stop the vehicle */
    00661     if (!was_stopped) cost.AddCost(StartStopVehicle(v, true));
    00662     if (cost.Failed()) return cost;
    00663
    00664     assert(v->IsStoppedInDepot());
    00665
    00666     /* We have to construct the new vehicle chain to test whether it is valid.
    00667      * Vehicle construction needs random bits, so we have to save the random seeds
    00668      * to prevent desyncs and to replay newgrf callbacks during DC_EXEC */
    00669     SavedRandomSeeds saved_seeds;
    00670     SaveRandomSeeds(&saved_seeds);
    00671     if (free_wagon) {
    00672       cost.AddCost(ReplaceFreeUnit(&v, flags & ~DC_EXEC, &nothing_to_do));
    00673     } else {
    00674       cost.AddCost(ReplaceChain(&v, flags & ~DC_EXEC, wagon_removal, &nothing_to_do));
    00675     }
    00676     RestoreRandomSeeds(saved_seeds);
    00677
    00678     if (cost.Succeeded() && (flags & DC_EXEC) != 0) {
    00679       CommandCost ret;
    00680       if (free_wagon) {
    00681         ret = ReplaceFreeUnit(&v, flags, &nothing_to_do);
    00682       } else {
    00683         ret = ReplaceChain(&v, flags, wagon_removal, &nothing_to_do);
    00684       }
    00685       assert(ret.Succeeded() && ret.GetCost() == cost.GetCost());
    00686     }
    00687
    00688     /* Restart the vehicle */
    00689     if (!was_stopped) cost.AddCost(StartStopVehicle(v, false));
    00690   }
    00691
    00692   if (cost.Succeeded() && nothing_to_do) cost = CommandCost(STR_ERROR_AUTOREPLACE_NOTHING_TO_DO);
    00693   return cost;
    00694 }