autoreplace_cmd.cpp

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00001 /* $Id: autoreplace_cmd.cpp 20585 2010-08-20 18:28:46Z rubidium $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "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 #include "core/random_func.hpp"
00024 
00025 #include "table/strings.h"
00026 
00027 extern void ChangeVehicleViewports(VehicleID from_index, VehicleID to_index);
00028 extern void ChangeVehicleNews(VehicleID from_index, VehicleID to_index);
00029 extern void ChangeVehicleViewWindow(VehicleID from_index, VehicleID to_index);
00030 
00037 static bool EnginesHaveCargoInCommon(EngineID engine_a, EngineID engine_b)
00038 {
00039   uint32 available_cargos_a = GetUnionOfArticulatedRefitMasks(engine_a, true);
00040   uint32 available_cargos_b = GetUnionOfArticulatedRefitMasks(engine_b, true);
00041   return (available_cargos_a == 0 || available_cargos_b == 0 || (available_cargos_a & available_cargos_b) != 0);
00042 }
00043 
00051 bool CheckAutoreplaceValidity(EngineID from, EngineID to, CompanyID company)
00052 {
00053   assert(Engine::IsValidID(from) && Engine::IsValidID(to));
00054 
00055   /* we can't replace an engine into itself (that would be autorenew) */
00056   if (from == to) return false;
00057 
00058   const Engine *e_from = Engine::Get(from);
00059   const Engine *e_to = Engine::Get(to);
00060   VehicleType type = e_from->type;
00061 
00062   /* check that the new vehicle type is available to the company and its type is the same as the original one */
00063   if (!IsEngineBuildable(to, type, company)) return false;
00064 
00065   switch (type) {
00066     case VEH_TRAIN: {
00067       /* make sure the railtypes are compatible */
00068       if ((GetRailTypeInfo(e_from->u.rail.railtype)->compatible_railtypes & GetRailTypeInfo(e_to->u.rail.railtype)->compatible_railtypes) == 0) return false;
00069 
00070       /* make sure we do not replace wagons with engines or vise versa */
00071       if ((e_from->u.rail.railveh_type == RAILVEH_WAGON) != (e_to->u.rail.railveh_type == RAILVEH_WAGON)) return false;
00072       break;
00073     }
00074 
00075     case VEH_ROAD:
00076       /* make sure that we do not replace a tram with a normal road vehicles or vise versa */
00077       if (HasBit(e_from->info.misc_flags, EF_ROAD_TRAM) != HasBit(e_to->info.misc_flags, EF_ROAD_TRAM)) return false;
00078       break;
00079 
00080     case VEH_AIRCRAFT:
00081       /* make sure that we do not replace a plane with a helicopter or vise versa */
00082       if ((e_from->u.air.subtype & AIR_CTOL) != (e_to->u.air.subtype & AIR_CTOL)) return false;
00083       break;
00084 
00085     default: break;
00086   }
00087 
00088   /* the engines needs to be able to carry the same cargo */
00089   return EnginesHaveCargoInCommon(from, to);
00090 }
00091 
00097 static void TransferCargo(Vehicle *old_veh, Vehicle *new_head, bool part_of_chain)
00098 {
00099   assert(!part_of_chain || new_head->IsPrimaryVehicle());
00100   /* Loop through source parts */
00101   for (Vehicle *src = old_veh; src != NULL; src = src->Next()) {
00102     if (!part_of_chain && src->type == VEH_TRAIN && src != old_veh && src != Train::From(old_veh)->other_multiheaded_part && !Train::From(src)->IsArticulatedPart()) {
00103       /* Skip vehicles, which do not belong to old_veh */
00104       src = Train::From(src)->GetLastEnginePart();
00105       continue;
00106     }
00107     if (src->cargo_type >= NUM_CARGO || src->cargo.Count() == 0) continue;
00108 
00109     /* Find free space in the new chain */
00110     for (Vehicle *dest = new_head; dest != NULL && src->cargo.Count() > 0; dest = dest->Next()) {
00111       if (!part_of_chain && dest->type == VEH_TRAIN && dest != new_head && dest != Train::From(new_head)->other_multiheaded_part && !Train::From(dest)->IsArticulatedPart()) {
00112         /* Skip vehicles, which do not belong to new_head */
00113         dest = Train::From(dest)->GetLastEnginePart();
00114         continue;
00115       }
00116       if (dest->cargo_type != src->cargo_type) continue;
00117 
00118       uint amount = min(src->cargo.Count(), dest->cargo_cap - dest->cargo.Count());
00119       if (amount <= 0) continue;
00120 
00121       src->cargo.MoveTo(&dest->cargo, amount, VehicleCargoList::MTA_UNLOAD, NULL);
00122     }
00123   }
00124 
00125   /* Update train weight etc., the old vehicle will be sold anyway */
00126   if (part_of_chain && new_head->type == VEH_TRAIN) Train::From(new_head)->ConsistChanged(true);
00127 }
00128 
00135 static bool VerifyAutoreplaceRefitForOrders(const Vehicle *v, EngineID engine_type)
00136 {
00137   const Order *o;
00138   const Vehicle *u;
00139 
00140   uint32 union_refit_mask_a = GetUnionOfArticulatedRefitMasks(v->engine_type, false);
00141   uint32 union_refit_mask_b = GetUnionOfArticulatedRefitMasks(engine_type, false);
00142 
00143   if (v->type == VEH_TRAIN) {
00144     u = v->First();
00145   } else {
00146     u = v;
00147   }
00148 
00149   FOR_VEHICLE_ORDERS(u, o) {
00150     if (!o->IsRefit()) continue;
00151     CargoID cargo_type = o->GetRefitCargo();
00152 
00153     if (!HasBit(union_refit_mask_a, cargo_type)) continue;
00154     if (!HasBit(union_refit_mask_b, cargo_type)) return false;
00155   }
00156 
00157   return true;
00158 }
00159 
00169 static CargoID GetNewCargoTypeForReplace(Vehicle *v, EngineID engine_type, bool part_of_chain)
00170 {
00171   CargoID cargo_type;
00172   uint32 available_cargo_types, union_mask;
00173   GetArticulatedRefitMasks(engine_type, true, &union_mask, &available_cargo_types);
00174 
00175   if (union_mask == 0) return CT_NO_REFIT; // Don't try to refit an engine with no cargo capacity
00176 
00177   if (IsArticulatedVehicleCarryingDifferentCargos(v, &cargo_type)) return CT_INVALID; // We cannot refit to mixed cargos in an automated way
00178 
00179   if (cargo_type == CT_INVALID) {
00180     if (v->type != VEH_TRAIN) return CT_NO_REFIT; // If the vehicle does not carry anything at all, every replacement is fine.
00181 
00182     if (!part_of_chain) return CT_NO_REFIT;
00183 
00184     /* the old engine didn't have cargo capacity, but the new one does
00185      * now we will figure out what cargo the train is carrying and refit to fit this */
00186 
00187     for (v = v->First(); v != NULL; v = v->Next()) {
00188       if (v->cargo_cap == 0) continue;
00189       /* Now we found a cargo type being carried on the train and we will see if it is possible to carry to this one */
00190       if (HasBit(available_cargo_types, v->cargo_type)) {
00191         /* Do we have to refit the vehicle, or is it already carrying the right cargo? */
00192         CargoArray default_capacity = GetCapacityOfArticulatedParts(engine_type);
00193         for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
00194           if (cid != v->cargo_type && default_capacity[cid] > 0) return v->cargo_type;
00195         }
00196 
00197         return CT_NO_REFIT;
00198       }
00199     }
00200 
00201     return CT_NO_REFIT; // We failed to find a cargo type on the old vehicle and we will not refit the new one
00202   } else {
00203     if (!HasBit(available_cargo_types, cargo_type)) return CT_INVALID; // We can't refit the vehicle to carry the cargo we want
00204 
00205     if (part_of_chain && !VerifyAutoreplaceRefitForOrders(v, engine_type)) return CT_INVALID; // Some refit orders lose their effect
00206 
00207     /* Do we have to refit the vehicle, or is it already carrying the right cargo? */
00208     CargoArray default_capacity = GetCapacityOfArticulatedParts(engine_type);
00209     for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
00210       if (cid != cargo_type && default_capacity[cid] > 0) return cargo_type;
00211     }
00212 
00213     return CT_NO_REFIT;
00214   }
00215 }
00216 
00222 static EngineID GetNewEngineType(const Vehicle *v, const Company *c)
00223 {
00224   assert(v->type != VEH_TRAIN || !Train::From(v)->IsArticulatedPart());
00225 
00226   if (v->type == VEH_TRAIN && Train::From(v)->IsRearDualheaded()) {
00227     /* we build the rear ends of multiheaded trains with the front ones */
00228     return INVALID_ENGINE;
00229   }
00230 
00231   EngineID e = EngineReplacementForCompany(c, v->engine_type, v->group_id);
00232 
00233   if (e != INVALID_ENGINE && IsEngineBuildable(e, v->type, _current_company)) {
00234     return e;
00235   }
00236 
00237   if (v->NeedsAutorenewing(c) && // replace if engine is too old
00238       IsEngineBuildable(v->engine_type, v->type, _current_company)) { // engine can still be build
00239     return v->engine_type;
00240   }
00241 
00242   return INVALID_ENGINE;
00243 }
00244 
00252 static CommandCost BuildReplacementVehicle(Vehicle *old_veh, Vehicle **new_vehicle, bool part_of_chain)
00253 {
00254   *new_vehicle = NULL;
00255 
00256   /* Shall the vehicle be replaced? */
00257   const Company *c = Company::Get(_current_company);
00258   EngineID e = GetNewEngineType(old_veh, c);
00259   if (e == INVALID_ENGINE) return CommandCost(); // neither autoreplace is set, nor autorenew is triggered
00260 
00261   /* Does it need to be refitted */
00262   CargoID refit_cargo = GetNewCargoTypeForReplace(old_veh, e, part_of_chain);
00263   if (refit_cargo == CT_INVALID) return CommandCost(); // incompatible cargos
00264 
00265   /* Build the new vehicle */
00266   CommandCost cost = DoCommand(old_veh->tile, e, 0, DC_EXEC | DC_AUTOREPLACE, GetCmdBuildVeh(old_veh));
00267   if (cost.Failed()) return cost;
00268 
00269   Vehicle *new_veh = Vehicle::Get(_new_vehicle_id);
00270   *new_vehicle = new_veh;
00271 
00272   /* Refit the vehicle if needed */
00273   byte subtype = GetBestFittingSubType(old_veh, new_veh);
00274   /* If the subtype isn't zero and the refit cargo is not set,
00275    * we're better off setting the refit cargo too. */
00276   if (subtype != 0 && refit_cargo == CT_NO_REFIT) refit_cargo = old_veh->cargo_type;
00277 
00278   if (refit_cargo != CT_NO_REFIT) {
00279     cost.AddCost(DoCommand(0, new_veh->index, refit_cargo | (subtype << 8), DC_EXEC, GetCmdRefitVeh(new_veh)));
00280     assert(cost.Succeeded()); // This should be ensured by GetNewCargoTypeForReplace()
00281   }
00282 
00283   /* Try to reverse the vehicle, but do not care if it fails as the new type might not be reversible */
00284   if (new_veh->type == VEH_TRAIN && HasBit(Train::From(old_veh)->flags, VRF_REVERSE_DIRECTION)) {
00285     DoCommand(0, new_veh->index, true, DC_EXEC, CMD_REVERSE_TRAIN_DIRECTION);
00286   }
00287 
00288   return cost;
00289 }
00290 
00296 static inline CommandCost StartStopVehicle(const Vehicle *v, bool evaluate_callback)
00297 {
00298   return DoCommand(0, v->index, evaluate_callback ? 1 : 0, DC_EXEC | DC_AUTOREPLACE, CMD_START_STOP_VEHICLE);
00299 }
00300 
00308 static inline CommandCost MoveVehicle(const Vehicle *v, const Vehicle *after, DoCommandFlag flags, bool whole_chain)
00309 {
00310   return DoCommand(0, v->index | (after != NULL ? after->index : INVALID_VEHICLE) << 16, whole_chain ? 1 : 0, flags, CMD_MOVE_RAIL_VEHICLE);
00311 }
00312 
00318 static CommandCost CopyHeadSpecificThings(Vehicle *old_head, Vehicle *new_head, DoCommandFlag flags)
00319 {
00320   CommandCost cost = CommandCost();
00321 
00322   /* Share orders */
00323   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));
00324 
00325   /* Copy group membership */
00326   if (cost.Succeeded() && old_head != new_head) cost.AddCost(DoCommand(0, old_head->group_id, new_head->index, DC_EXEC, CMD_ADD_VEHICLE_GROUP));
00327 
00328   /* Perform start/stop check whether the new vehicle suits newgrf restrictions etc. */
00329   if (cost.Succeeded()) {
00330     /* Start the vehicle, might be denied by certain things */
00331     assert((new_head->vehstatus & VS_STOPPED) != 0);
00332     cost.AddCost(StartStopVehicle(new_head, true));
00333 
00334     /* Stop the vehicle again, but do not care about evil newgrfs allowing starting but not stopping :p */
00335     if (cost.Succeeded()) cost.AddCost(StartStopVehicle(new_head, false));
00336   }
00337 
00338   /* Last do those things which do never fail (resp. we do not care about), but which are not undo-able */
00339   if (cost.Succeeded() && old_head != new_head && (flags & DC_EXEC) != 0) {
00340     /* Copy vehicle name */
00341     if (old_head->name != NULL) {
00342       DoCommand(0, new_head->index, 0, DC_EXEC | DC_AUTOREPLACE, CMD_RENAME_VEHICLE, old_head->name);
00343     }
00344 
00345     /* Copy other things which cannot be copied by a command and which shall not stay resetted from the build vehicle command */
00346     new_head->CopyVehicleConfigAndStatistics(old_head);
00347 
00348     /* Switch vehicle windows/news to the new vehicle, so they are not closed/deleted when the old vehicle is sold */
00349     ChangeVehicleViewports(old_head->index, new_head->index);
00350     ChangeVehicleViewWindow(old_head->index, new_head->index);
00351     ChangeVehicleNews(old_head->index, new_head->index);
00352   }
00353 
00354   return cost;
00355 }
00356 
00363 static CommandCost ReplaceFreeUnit(Vehicle **single_unit, DoCommandFlag flags, bool *nothing_to_do)
00364 {
00365   Train *old_v = Train::From(*single_unit);
00366   assert(!old_v->IsArticulatedPart() && !old_v->IsRearDualheaded());
00367 
00368   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00369 
00370   /* Build and refit replacement vehicle */
00371   Vehicle *new_v = NULL;
00372   cost.AddCost(BuildReplacementVehicle(old_v, &new_v, false));
00373 
00374   /* Was a new vehicle constructed? */
00375   if (cost.Succeeded() && new_v != NULL) {
00376     *nothing_to_do = false;
00377 
00378     if ((flags & DC_EXEC) != 0) {
00379       /* Move the new vehicle behind the old */
00380       MoveVehicle(new_v, old_v, DC_EXEC, false);
00381 
00382       /* Take over cargo
00383        * Note: We do only transfer cargo from the old to the new vehicle.
00384        *       I.e. we do not transfer remaining cargo to other vehicles.
00385        *       Else you would also need to consider moving cargo to other free chains,
00386        *       or doing the same in ReplaceChain(), which would be quite troublesome.
00387        */
00388       TransferCargo(old_v, new_v, false);
00389 
00390       *single_unit = new_v;
00391     }
00392 
00393     /* Sell the old vehicle */
00394     cost.AddCost(DoCommand(0, old_v->index, 0, flags, GetCmdSellVeh(old_v)));
00395 
00396     /* If we are not in DC_EXEC undo everything */
00397     if ((flags & DC_EXEC) == 0) {
00398       DoCommand(0, new_v->index, 0, DC_EXEC, GetCmdSellVeh(new_v));
00399     }
00400   }
00401 
00402   return cost;
00403 }
00404 
00412 static CommandCost ReplaceChain(Vehicle **chain, DoCommandFlag flags, bool wagon_removal, bool *nothing_to_do)
00413 {
00414   Vehicle *old_head = *chain;
00415   assert(old_head->IsPrimaryVehicle());
00416 
00417   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00418 
00419   if (old_head->type == VEH_TRAIN) {
00420     /* Store the length of the old vehicle chain, rounded up to whole tiles */
00421     uint16 old_total_length = (Train::From(old_head)->tcache.cached_total_length + TILE_SIZE - 1) / TILE_SIZE * TILE_SIZE;
00422 
00423     int num_units = 0; 
00424     for (Train *w = Train::From(old_head); w != NULL; w = w->GetNextUnit()) num_units++;
00425 
00426     Train **old_vehs = CallocT<Train *>(num_units); 
00427     Train **new_vehs = CallocT<Train *>(num_units); 
00428     Money *new_costs = MallocT<Money>(num_units);   
00429 
00430     /* Collect vehicles and build replacements
00431      * Note: The replacement vehicles can only successfully build as long as the old vehicles are still in their chain */
00432     int i;
00433     Train *w;
00434     for (w = Train::From(old_head), i = 0; w != NULL; w = w->GetNextUnit(), i++) {
00435       assert(i < num_units);
00436       old_vehs[i] = w;
00437 
00438       CommandCost ret = BuildReplacementVehicle(old_vehs[i], (Vehicle**)&new_vehs[i], true);
00439       cost.AddCost(ret);
00440       if (cost.Failed()) break;
00441 
00442       new_costs[i] = ret.GetCost();
00443       if (new_vehs[i] != NULL) *nothing_to_do = false;
00444     }
00445     Train *new_head = (new_vehs[0] != NULL ? new_vehs[0] : old_vehs[0]);
00446 
00447     /* Note: When autoreplace has already failed here, old_vehs[] is not completely initialized. But it is also not needed. */
00448     if (cost.Succeeded()) {
00449       /* Separate the head, so we can start constructing the new chain */
00450       Train *second = Train::From(old_head)->GetNextUnit();
00451       if (second != NULL) cost.AddCost(MoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true));
00452 
00453       assert(Train::From(new_head)->GetNextUnit() == NULL);
00454 
00455       /* Append engines to the new chain
00456        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
00457        * That way we also have less trouble when exceeding the unitnumber limit.
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 (new_vehs[i] != NULL) {
00467             /* Move the old engine to a separate row with DC_AUTOREPLACE. Else
00468              * moving the wagon in front may fail later due to unitnumber limit.
00469              * (We have to attach wagons without DC_AUTOREPLACE.) */
00470             MoveVehicle(old_vehs[i], NULL, DC_EXEC | DC_AUTOREPLACE, false);
00471           }
00472 
00473           if (last_engine == NULL) last_engine = append;
00474           cost.AddCost(MoveVehicle(append, new_head, DC_EXEC, false));
00475           if (cost.Failed()) break;
00476         }
00477         if (last_engine == NULL) last_engine = new_head;
00478       }
00479 
00480       /* When wagon removal is enabled and the new engines without any wagons are already longer than the old, we have to fail */
00481       if (cost.Succeeded() && wagon_removal && new_head->tcache.cached_total_length > old_total_length) cost = CommandCost(STR_ERROR_TRAIN_TOO_LONG_AFTER_REPLACEMENT);
00482 
00483       /* Append/insert wagons into the new vehicle chain
00484        * 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.
00485        */
00486       if (cost.Succeeded()) {
00487         for (int i = num_units - 1; i > 0; i--) {
00488           assert(last_engine != NULL);
00489           Vehicle *append = (new_vehs[i] != NULL ? new_vehs[i] : old_vehs[i]);
00490 
00491           if (RailVehInfo(append->engine_type)->railveh_type == RAILVEH_WAGON) {
00492             /* Insert wagon after 'last_engine' */
00493             CommandCost res = MoveVehicle(append, last_engine, DC_EXEC, false);
00494 
00495             if (res.Succeeded() && wagon_removal && new_head->tcache.cached_total_length > old_total_length) {
00496               MoveVehicle(append, NULL, DC_EXEC | DC_AUTOREPLACE, false);
00497               break;
00498             }
00499 
00500             cost.AddCost(res);
00501             if (cost.Failed()) break;
00502           } else {
00503             /* We have reached 'last_engine', continue with the next engine towards the front */
00504             assert(append == last_engine);
00505             last_engine = last_engine->GetPrevUnit();
00506           }
00507         }
00508       }
00509 
00510       /* Sell superfluous new vehicles that could not be inserted. */
00511       if (cost.Succeeded() && wagon_removal) {
00512         for (int i = 1; i < num_units; i++) {
00513           Vehicle *wagon = new_vehs[i];
00514           if (wagon == NULL) continue;
00515           if (wagon->First() == new_head) break;
00516 
00517           assert(RailVehInfo(wagon->engine_type)->railveh_type == RAILVEH_WAGON);
00518 
00519           /* Sell wagon */
00520           CommandCost ret = DoCommand(0, wagon->index, 0, DC_EXEC, GetCmdSellVeh(wagon));
00521           assert(ret.Succeeded());
00522           new_vehs[i] = NULL;
00523 
00524           /* Revert the money subtraction when the vehicle was built.
00525            * This value is different from the sell value, esp. because of refitting */
00526           cost.AddCost(-new_costs[i]);
00527         }
00528       }
00529 
00530       /* The new vehicle chain is constructed, now take over orders and everything... */
00531       if (cost.Succeeded()) cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
00532 
00533       if (cost.Succeeded()) {
00534         /* Success ! */
00535         if ((flags & DC_EXEC) != 0 && new_head != old_head) {
00536           *chain = new_head;
00537         }
00538 
00539         /* Transfer cargo of old vehicles and sell them */
00540         for (int i = 0; i < num_units; i++) {
00541           Vehicle *w = old_vehs[i];
00542           /* Is the vehicle again part of the new chain?
00543            * Note: We cannot test 'new_vehs[i] != NULL' as wagon removal might cause to remove both */
00544           if (w->First() == new_head) continue;
00545 
00546           if ((flags & DC_EXEC) != 0) TransferCargo(w, new_head, true);
00547 
00548           /* Sell the vehicle.
00549            * Note: This might temporarly construct new trains, so use DC_AUTOREPLACE to prevent
00550            *       it from failing due to engine limits. */
00551           cost.AddCost(DoCommand(0, w->index, 0, flags | DC_AUTOREPLACE, GetCmdSellVeh(w)));
00552           if ((flags & DC_EXEC) != 0) {
00553             old_vehs[i] = NULL;
00554             if (i == 0) old_head = NULL;
00555           }
00556         }
00557       }
00558 
00559       /* If we are not in DC_EXEC undo everything, i.e. rearrange old vehicles.
00560        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
00561        * Note: The vehicle attach callback is disabled here :) */
00562       if ((flags & DC_EXEC) == 0) {
00563         /* Separate the head, so we can reattach the old vehicles */
00564         Train *second = Train::From(old_head)->GetNextUnit();
00565         if (second != NULL) MoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true);
00566 
00567         assert(Train::From(old_head)->GetNextUnit() == NULL);
00568 
00569         for (int i = num_units - 1; i > 0; i--) {
00570           CommandCost ret = MoveVehicle(old_vehs[i], old_head, DC_EXEC | DC_AUTOREPLACE, false);
00571           assert(ret.Succeeded());
00572         }
00573       }
00574     }
00575 
00576     /* Finally undo buying of new vehicles */
00577     if ((flags & DC_EXEC) == 0) {
00578       for (int i = num_units - 1; i >= 0; i--) {
00579         if (new_vehs[i] != NULL) {
00580           DoCommand(0, new_vehs[i]->index, 0, DC_EXEC, GetCmdSellVeh(new_vehs[i]));
00581           new_vehs[i] = NULL;
00582         }
00583       }
00584     }
00585 
00586     free(old_vehs);
00587     free(new_vehs);
00588     free(new_costs);
00589   } else {
00590     /* Build and refit replacement vehicle */
00591     Vehicle *new_head = NULL;
00592     cost.AddCost(BuildReplacementVehicle(old_head, &new_head, true));
00593 
00594     /* Was a new vehicle constructed? */
00595     if (cost.Succeeded() && new_head != NULL) {
00596       *nothing_to_do = false;
00597 
00598       /* The new vehicle is constructed, now take over orders and everything... */
00599       cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
00600 
00601       if (cost.Succeeded()) {
00602         /* The new vehicle is constructed, now take over cargo */
00603         if ((flags & DC_EXEC) != 0) {
00604           TransferCargo(old_head, new_head, true);
00605           *chain = new_head;
00606         }
00607 
00608         /* Sell the old vehicle */
00609         cost.AddCost(DoCommand(0, old_head->index, 0, flags, GetCmdSellVeh(old_head)));
00610       }
00611 
00612       /* If we are not in DC_EXEC undo everything */
00613       if ((flags & DC_EXEC) == 0) {
00614         DoCommand(0, new_head->index, 0, DC_EXEC, GetCmdSellVeh(new_head));
00615       }
00616     }
00617   }
00618 
00619   return cost;
00620 }
00621 
00631 CommandCost CmdAutoreplaceVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00632 {
00633   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00634   bool nothing_to_do = true;
00635 
00636   Vehicle *v = Vehicle::GetIfValid(p1);
00637   if (v == NULL) return CMD_ERROR;
00638 
00639   if (!CheckOwnership(v->owner)) return CMD_ERROR;
00640   if (!v->IsInDepot()) return CMD_ERROR;
00641   if (v->vehstatus & VS_CRASHED) return CMD_ERROR;
00642 
00643   bool free_wagon = false;
00644   if (v->type == VEH_TRAIN) {
00645     Train *t = Train::From(v);
00646     if (t->IsArticulatedPart() || t->IsRearDualheaded()) return CMD_ERROR;
00647     free_wagon = !t->IsFrontEngine();
00648     if (free_wagon && t->First()->IsFrontEngine()) return CMD_ERROR;
00649   } else {
00650     if (!v->IsPrimaryVehicle()) return CMD_ERROR;
00651   }
00652 
00653   const Company *c = Company::Get(_current_company);
00654   bool wagon_removal = c->settings.renew_keep_length;
00655 
00656   /* Test whether any replacement is set, before issuing a whole lot of commands that would end in nothing changed */
00657   Vehicle *w = v;
00658   bool any_replacements = false;
00659   while (w != NULL && !any_replacements) {
00660     any_replacements = (GetNewEngineType(w, c) != INVALID_ENGINE);
00661     w = (!free_wagon && w->type == VEH_TRAIN ? Train::From(w)->GetNextUnit() : NULL);
00662   }
00663 
00664   if (any_replacements) {
00665     bool was_stopped = free_wagon || ((v->vehstatus & VS_STOPPED) != 0);
00666 
00667     /* Stop the vehicle */
00668     if (!was_stopped) cost.AddCost(StartStopVehicle(v, true));
00669     if (cost.Failed()) return cost;
00670 
00671     assert(v->IsStoppedInDepot());
00672 
00673     /* We have to construct the new vehicle chain to test whether it is valid.
00674      * Vehicle construction needs random bits, so we have to save the random seeds
00675      * to prevent desyncs and to replay newgrf callbacks during DC_EXEC */
00676     SavedRandomSeeds saved_seeds;
00677     SaveRandomSeeds(&saved_seeds);
00678     if (free_wagon) {
00679       cost.AddCost(ReplaceFreeUnit(&v, flags & ~DC_EXEC, &nothing_to_do));
00680     } else {
00681       cost.AddCost(ReplaceChain(&v, flags & ~DC_EXEC, wagon_removal, &nothing_to_do));
00682     }
00683     RestoreRandomSeeds(saved_seeds);
00684 
00685     if (cost.Succeeded() && (flags & DC_EXEC) != 0) {
00686       CommandCost ret;
00687       if (free_wagon) {
00688         ret = ReplaceFreeUnit(&v, flags, &nothing_to_do);
00689       } else {
00690         ret = ReplaceChain(&v, flags, wagon_removal, &nothing_to_do);
00691       }
00692       assert(ret.Succeeded() && ret.GetCost() == cost.GetCost());
00693     }
00694 
00695     /* Restart the vehicle */
00696     if (!was_stopped) cost.AddCost(StartStopVehicle(v, false));
00697   }
00698 
00699   if (cost.Succeeded() && nothing_to_do) cost = CommandCost(STR_ERROR_AUTOREPLACE_NOTHING_TO_DO);
00700   return cost;
00701 }

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