autoreplace_cmd.cpp

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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 "command_func.h"
00016 #include "engine_func.h"
00017 #include "vehicle_func.h"
00018 #include "autoreplace_func.h"
00019 #include "autoreplace_gui.h"
00020 #include "group.h"
00021 #include "articulated_vehicles.h"
00022 #include "core/random_func.hpp"
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 
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 
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 && !src->IsArticulatedPart()) {
00104       /* Skip vehicles, which do not belong to old_veh */
00105       src = 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 && !dest->IsArticulatedPart()) {
00113         /* Skip vehicles, which do not belong to new_head */
00114         dest = 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);
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) Train::From(new_head)->ConsistChanged(true);
00128 }
00129 
00136 static bool VerifyAutoreplaceRefitForOrders(const Vehicle *v, EngineID engine_type)
00137 {
00138 
00139   uint32 union_refit_mask_a = GetUnionOfArticulatedRefitMasks(v->engine_type, false);
00140   uint32 union_refit_mask_b = GetUnionOfArticulatedRefitMasks(engine_type, false);
00141 
00142   const Order *o;
00143   const Vehicle *u = (v->type == VEH_TRAIN) ? v->First() : v;
00144   FOR_VEHICLE_ORDERS(u, o) {
00145     if (!o->IsRefit() || o->IsAutoRefit()) continue;
00146     CargoID cargo_type = o->GetRefitCargo();
00147 
00148     if (!HasBit(union_refit_mask_a, cargo_type)) continue;
00149     if (!HasBit(union_refit_mask_b, cargo_type)) return false;
00150   }
00151 
00152   return true;
00153 }
00154 
00164 static CargoID GetNewCargoTypeForReplace(Vehicle *v, EngineID engine_type, bool part_of_chain)
00165 {
00166   uint32 available_cargo_types, union_mask;
00167   GetArticulatedRefitMasks(engine_type, true, &union_mask, &available_cargo_types);
00168 
00169   if (union_mask == 0) return CT_NO_REFIT; // Don't try to refit an engine with no cargo capacity
00170 
00171   CargoID cargo_type;
00172   if (IsArticulatedVehicleCarryingDifferentCargos(v, &cargo_type)) return CT_INVALID; // We cannot refit to mixed cargos in an automated way
00173 
00174   if (cargo_type == CT_INVALID) {
00175     if (v->type != VEH_TRAIN) return CT_NO_REFIT; // If the vehicle does not carry anything at all, every replacement is fine.
00176 
00177     if (!part_of_chain) return CT_NO_REFIT;
00178 
00179     /* the old engine didn't have cargo capacity, but the new one does
00180      * now we will figure out what cargo the train is carrying and refit to fit this */
00181 
00182     for (v = v->First(); v != NULL; v = v->Next()) {
00183       if (v->cargo_cap == 0) continue;
00184       /* Now we found a cargo type being carried on the train and we will see if it is possible to carry to this one */
00185       if (HasBit(available_cargo_types, v->cargo_type)) {
00186         /* Do we have to refit the vehicle, or is it already carrying the right cargo? */
00187         CargoArray default_capacity = GetCapacityOfArticulatedParts(engine_type);
00188         for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
00189           if (cid != v->cargo_type && default_capacity[cid] > 0) return v->cargo_type;
00190         }
00191 
00192         return CT_NO_REFIT;
00193       }
00194     }
00195 
00196     return CT_NO_REFIT; // We failed to find a cargo type on the old vehicle and we will not refit the new one
00197   } else {
00198     if (!HasBit(available_cargo_types, cargo_type)) return CT_INVALID; // We can't refit the vehicle to carry the cargo we want
00199 
00200     if (part_of_chain && !VerifyAutoreplaceRefitForOrders(v, engine_type)) return CT_INVALID; // Some refit orders lose their effect
00201 
00202     /* Do we have to refit the vehicle, or is it already carrying the right cargo? */
00203     CargoArray default_capacity = GetCapacityOfArticulatedParts(engine_type);
00204     for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
00205       if (cid != cargo_type && default_capacity[cid] > 0) return cargo_type;
00206     }
00207 
00208     return CT_NO_REFIT;
00209   }
00210 }
00211 
00219 static CommandCost GetNewEngineType(const Vehicle *v, const Company *c, EngineID &e)
00220 {
00221   assert(v->type != VEH_TRAIN || !v->IsArticulatedPart());
00222 
00223   e = INVALID_ENGINE;
00224 
00225   if (v->type == VEH_TRAIN && Train::From(v)->IsRearDualheaded()) {
00226     /* we build the rear ends of multiheaded trains with the front ones */
00227     return CommandCost();
00228   }
00229 
00230   e = EngineReplacementForCompany(c, v->engine_type, v->group_id);
00231 
00232   /* Autoreplace, if engine is available */
00233   if (e != INVALID_ENGINE && IsEngineBuildable(e, v->type, _current_company)) {
00234     return CommandCost();
00235   }
00236 
00237   /* Autorenew if needed */
00238   if (v->NeedsAutorenewing(c)) e = v->engine_type;
00239 
00240   /* Nothing to do or all is fine? */
00241   if (e == INVALID_ENGINE || IsEngineBuildable(e, v->type, _current_company)) return CommandCost();
00242 
00243   /* The engine we need is not available. Report error to user */
00244   return CommandCost(STR_ERROR_RAIL_VEHICLE_NOT_AVAILABLE + v->type);
00245 }
00246 
00255 static CommandCost BuildReplacementVehicle(Vehicle *old_veh, Vehicle **new_vehicle, bool part_of_chain)
00256 {
00257   *new_vehicle = NULL;
00258 
00259   /* Shall the vehicle be replaced? */
00260   const Company *c = Company::Get(_current_company);
00261   EngineID e;
00262   CommandCost cost = GetNewEngineType(old_veh, c, e);
00263   if (cost.Failed()) return cost;
00264   if (e == INVALID_ENGINE) return CommandCost(); // neither autoreplace is set, nor autorenew is triggered
00265 
00266   /* Does it need to be refitted */
00267   CargoID refit_cargo = GetNewCargoTypeForReplace(old_veh, e, part_of_chain);
00268   if (refit_cargo == CT_INVALID) return CommandCost(); // incompatible cargos
00269 
00270   /* Build the new vehicle */
00271   cost = DoCommand(old_veh->tile, e, 0, DC_EXEC | DC_AUTOREPLACE, GetCmdBuildVeh(old_veh));
00272   if (cost.Failed()) return cost;
00273 
00274   Vehicle *new_veh = Vehicle::Get(_new_vehicle_id);
00275   *new_vehicle = new_veh;
00276 
00277   /* Refit the vehicle if needed */
00278   byte subtype = GetBestFittingSubType(old_veh, new_veh);
00279   /* If the subtype isn't zero and the refit cargo is not set,
00280    * we're better off setting the refit cargo too. */
00281   if (subtype != 0 && refit_cargo == CT_NO_REFIT) refit_cargo = old_veh->cargo_type;
00282 
00283   if (refit_cargo != CT_NO_REFIT) {
00284     cost.AddCost(DoCommand(0, new_veh->index, refit_cargo | (subtype << 8), DC_EXEC, GetCmdRefitVeh(new_veh)));
00285     assert(cost.Succeeded()); // This should be ensured by GetNewCargoTypeForReplace()
00286   }
00287 
00288   /* Try to reverse the vehicle, but do not care if it fails as the new type might not be reversible */
00289   if (new_veh->type == VEH_TRAIN && HasBit(Train::From(old_veh)->flags, VRF_REVERSE_DIRECTION)) {
00290     DoCommand(0, new_veh->index, true, DC_EXEC, CMD_REVERSE_TRAIN_DIRECTION);
00291   }
00292 
00293   return cost;
00294 }
00295 
00302 static inline CommandCost CmdStartStopVehicle(const Vehicle *v, bool evaluate_callback)
00303 {
00304   return DoCommand(0, v->index, evaluate_callback ? 1 : 0, DC_EXEC | DC_AUTOREPLACE, CMD_START_STOP_VEHICLE);
00305 }
00306 
00315 static inline CommandCost CmdMoveVehicle(const Vehicle *v, const Vehicle *after, DoCommandFlag flags, bool whole_chain)
00316 {
00317   return DoCommand(0, v->index | (whole_chain ? 1 : 0) << 20, after != NULL ? after->index : INVALID_VEHICLE, flags, CMD_MOVE_RAIL_VEHICLE);
00318 }
00319 
00326 static CommandCost CopyHeadSpecificThings(Vehicle *old_head, Vehicle *new_head, DoCommandFlag flags)
00327 {
00328   CommandCost cost = CommandCost();
00329 
00330   /* Share orders */
00331   if (cost.Succeeded() && old_head != new_head) cost.AddCost(DoCommand(0, new_head->index | CO_SHARE << 30, old_head->index, DC_EXEC, CMD_CLONE_ORDER));
00332 
00333   /* Copy group membership */
00334   if (cost.Succeeded() && old_head != new_head) cost.AddCost(DoCommand(0, old_head->group_id, new_head->index, DC_EXEC, CMD_ADD_VEHICLE_GROUP));
00335 
00336   /* Perform start/stop check whether the new vehicle suits newgrf restrictions etc. */
00337   if (cost.Succeeded()) {
00338     /* Start the vehicle, might be denied by certain things */
00339     assert((new_head->vehstatus & VS_STOPPED) != 0);
00340     cost.AddCost(CmdStartStopVehicle(new_head, true));
00341 
00342     /* Stop the vehicle again, but do not care about evil newgrfs allowing starting but not stopping :p */
00343     if (cost.Succeeded()) cost.AddCost(CmdStartStopVehicle(new_head, false));
00344   }
00345 
00346   /* Last do those things which do never fail (resp. we do not care about), but which are not undo-able */
00347   if (cost.Succeeded() && old_head != new_head && (flags & DC_EXEC) != 0) {
00348     /* Copy vehicle name */
00349     if (old_head->name != NULL) {
00350       DoCommand(0, new_head->index, 0, DC_EXEC | DC_AUTOREPLACE, CMD_RENAME_VEHICLE, old_head->name);
00351     }
00352 
00353     /* Copy other things which cannot be copied by a command and which shall not stay resetted from the build vehicle command */
00354     new_head->CopyVehicleConfigAndStatistics(old_head);
00355 
00356     /* Switch vehicle windows/news to the new vehicle, so they are not closed/deleted when the old vehicle is sold */
00357     ChangeVehicleViewports(old_head->index, new_head->index);
00358     ChangeVehicleViewWindow(old_head->index, new_head->index);
00359     ChangeVehicleNews(old_head->index, new_head->index);
00360   }
00361 
00362   return cost;
00363 }
00364 
00372 static CommandCost ReplaceFreeUnit(Vehicle **single_unit, DoCommandFlag flags, bool *nothing_to_do)
00373 {
00374   Train *old_v = Train::From(*single_unit);
00375   assert(!old_v->IsArticulatedPart() && !old_v->IsRearDualheaded());
00376 
00377   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00378 
00379   /* Build and refit replacement vehicle */
00380   Vehicle *new_v = NULL;
00381   cost.AddCost(BuildReplacementVehicle(old_v, &new_v, false));
00382 
00383   /* Was a new vehicle constructed? */
00384   if (cost.Succeeded() && new_v != NULL) {
00385     *nothing_to_do = false;
00386 
00387     if ((flags & DC_EXEC) != 0) {
00388       /* Move the new vehicle behind the old */
00389       CmdMoveVehicle(new_v, old_v, DC_EXEC, false);
00390 
00391       /* Take over cargo
00392        * Note: We do only transfer cargo from the old to the new vehicle.
00393        *       I.e. we do not transfer remaining cargo to other vehicles.
00394        *       Else you would also need to consider moving cargo to other free chains,
00395        *       or doing the same in ReplaceChain(), which would be quite troublesome.
00396        */
00397       TransferCargo(old_v, new_v, false);
00398 
00399       *single_unit = new_v;
00400     }
00401 
00402     /* Sell the old vehicle */
00403     cost.AddCost(DoCommand(0, old_v->index, 0, flags, GetCmdSellVeh(old_v)));
00404 
00405     /* If we are not in DC_EXEC undo everything */
00406     if ((flags & DC_EXEC) == 0) {
00407       DoCommand(0, new_v->index, 0, DC_EXEC, GetCmdSellVeh(new_v));
00408     }
00409   }
00410 
00411   return cost;
00412 }
00413 
00422 static CommandCost ReplaceChain(Vehicle **chain, DoCommandFlag flags, bool wagon_removal, bool *nothing_to_do)
00423 {
00424   Vehicle *old_head = *chain;
00425   assert(old_head->IsPrimaryVehicle());
00426 
00427   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00428 
00429   if (old_head->type == VEH_TRAIN) {
00430     /* Store the length of the old vehicle chain, rounded up to whole tiles */
00431     uint16 old_total_length = CeilDiv(Train::From(old_head)->gcache.cached_total_length, TILE_SIZE) * TILE_SIZE;
00432 
00433     int num_units = 0; 
00434     for (Train *w = Train::From(old_head); w != NULL; w = w->GetNextUnit()) num_units++;
00435 
00436     Train **old_vehs = CallocT<Train *>(num_units); 
00437     Train **new_vehs = CallocT<Train *>(num_units); 
00438     Money *new_costs = MallocT<Money>(num_units);   
00439 
00440     /* Collect vehicles and build replacements
00441      * Note: The replacement vehicles can only successfully build as long as the old vehicles are still in their chain */
00442     int i;
00443     Train *w;
00444     for (w = Train::From(old_head), i = 0; w != NULL; w = w->GetNextUnit(), i++) {
00445       assert(i < num_units);
00446       old_vehs[i] = w;
00447 
00448       CommandCost ret = BuildReplacementVehicle(old_vehs[i], (Vehicle**)&new_vehs[i], true);
00449       cost.AddCost(ret);
00450       if (cost.Failed()) break;
00451 
00452       new_costs[i] = ret.GetCost();
00453       if (new_vehs[i] != NULL) *nothing_to_do = false;
00454     }
00455     Train *new_head = (new_vehs[0] != NULL ? new_vehs[0] : old_vehs[0]);
00456 
00457     /* Note: When autoreplace has already failed here, old_vehs[] is not completely initialized. But it is also not needed. */
00458     if (cost.Succeeded()) {
00459       /* Separate the head, so we can start constructing the new chain */
00460       Train *second = Train::From(old_head)->GetNextUnit();
00461       if (second != NULL) cost.AddCost(CmdMoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true));
00462 
00463       assert(Train::From(new_head)->GetNextUnit() == NULL);
00464 
00465       /* Append engines to the new chain
00466        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
00467        * That way we also have less trouble when exceeding the unitnumber limit.
00468        * OTOH the vehicle attach callback is more expensive this way :s */
00469       Train *last_engine = NULL; 
00470       if (cost.Succeeded()) {
00471         for (int i = num_units - 1; i > 0; i--) {
00472           Train *append = (new_vehs[i] != NULL ? new_vehs[i] : old_vehs[i]);
00473 
00474           if (RailVehInfo(append->engine_type)->railveh_type == RAILVEH_WAGON) continue;
00475 
00476           if (new_vehs[i] != NULL) {
00477             /* Move the old engine to a separate row with DC_AUTOREPLACE. Else
00478              * moving the wagon in front may fail later due to unitnumber limit.
00479              * (We have to attach wagons without DC_AUTOREPLACE.) */
00480             CmdMoveVehicle(old_vehs[i], NULL, DC_EXEC | DC_AUTOREPLACE, false);
00481           }
00482 
00483           if (last_engine == NULL) last_engine = append;
00484           cost.AddCost(CmdMoveVehicle(append, new_head, DC_EXEC, false));
00485           if (cost.Failed()) break;
00486         }
00487         if (last_engine == NULL) last_engine = new_head;
00488       }
00489 
00490       /* When wagon removal is enabled and the new engines without any wagons are already longer than the old, we have to fail */
00491       if (cost.Succeeded() && wagon_removal && new_head->gcache.cached_total_length > old_total_length) cost = CommandCost(STR_ERROR_TRAIN_TOO_LONG_AFTER_REPLACEMENT);
00492 
00493       /* Append/insert wagons into the new vehicle chain
00494        * 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.
00495        */
00496       if (cost.Succeeded()) {
00497         for (int i = num_units - 1; i > 0; i--) {
00498           assert(last_engine != NULL);
00499           Vehicle *append = (new_vehs[i] != NULL ? new_vehs[i] : old_vehs[i]);
00500 
00501           if (RailVehInfo(append->engine_type)->railveh_type == RAILVEH_WAGON) {
00502             /* Insert wagon after 'last_engine' */
00503             CommandCost res = CmdMoveVehicle(append, last_engine, DC_EXEC, false);
00504 
00505             /* When we allow removal of wagons, either the move failing due
00506              * to the train becoming too long, or the train becoming longer
00507              * would move the vehicle to the empty vehicle chain. */
00508             if (wagon_removal && (res.Failed() ? res.GetErrorMessage() == STR_ERROR_TRAIN_TOO_LONG : new_head->gcache.cached_total_length > old_total_length)) {
00509               CmdMoveVehicle(append, NULL, DC_EXEC | DC_AUTOREPLACE, false);
00510               break;
00511             }
00512 
00513             cost.AddCost(res);
00514             if (cost.Failed()) break;
00515           } else {
00516             /* We have reached 'last_engine', continue with the next engine towards the front */
00517             assert(append == last_engine);
00518             last_engine = last_engine->GetPrevUnit();
00519           }
00520         }
00521       }
00522 
00523       /* Sell superfluous new vehicles that could not be inserted. */
00524       if (cost.Succeeded() && wagon_removal) {
00525         assert(new_head->gcache.cached_total_length <= _settings_game.vehicle.max_train_length * TILE_SIZE);
00526         for (int i = 1; i < num_units; i++) {
00527           Vehicle *wagon = new_vehs[i];
00528           if (wagon == NULL) continue;
00529           if (wagon->First() == new_head) break;
00530 
00531           assert(RailVehInfo(wagon->engine_type)->railveh_type == RAILVEH_WAGON);
00532 
00533           /* Sell wagon */
00534           CommandCost ret = DoCommand(0, wagon->index, 0, DC_EXEC, GetCmdSellVeh(wagon));
00535           assert(ret.Succeeded());
00536           new_vehs[i] = NULL;
00537 
00538           /* Revert the money subtraction when the vehicle was built.
00539            * This value is different from the sell value, esp. because of refitting */
00540           cost.AddCost(-new_costs[i]);
00541         }
00542       }
00543 
00544       /* The new vehicle chain is constructed, now take over orders and everything... */
00545       if (cost.Succeeded()) cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
00546 
00547       if (cost.Succeeded()) {
00548         /* Success ! */
00549         if ((flags & DC_EXEC) != 0 && new_head != old_head) {
00550           *chain = new_head;
00551         }
00552 
00553         /* Transfer cargo of old vehicles and sell them */
00554         for (int i = 0; i < num_units; i++) {
00555           Vehicle *w = old_vehs[i];
00556           /* Is the vehicle again part of the new chain?
00557            * Note: We cannot test 'new_vehs[i] != NULL' as wagon removal might cause to remove both */
00558           if (w->First() == new_head) continue;
00559 
00560           if ((flags & DC_EXEC) != 0) TransferCargo(w, new_head, true);
00561 
00562           /* Sell the vehicle.
00563            * Note: This might temporarly construct new trains, so use DC_AUTOREPLACE to prevent
00564            *       it from failing due to engine limits. */
00565           cost.AddCost(DoCommand(0, w->index, 0, flags | DC_AUTOREPLACE, GetCmdSellVeh(w)));
00566           if ((flags & DC_EXEC) != 0) {
00567             old_vehs[i] = NULL;
00568             if (i == 0) old_head = NULL;
00569           }
00570         }
00571       }
00572 
00573       /* If we are not in DC_EXEC undo everything, i.e. rearrange old vehicles.
00574        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
00575        * Note: The vehicle attach callback is disabled here :) */
00576       if ((flags & DC_EXEC) == 0) {
00577         /* Separate the head, so we can reattach the old vehicles */
00578         Train *second = Train::From(old_head)->GetNextUnit();
00579         if (second != NULL) CmdMoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true);
00580 
00581         assert(Train::From(old_head)->GetNextUnit() == NULL);
00582 
00583         for (int i = num_units - 1; i > 0; i--) {
00584           CommandCost ret = CmdMoveVehicle(old_vehs[i], old_head, DC_EXEC | DC_AUTOREPLACE, false);
00585           assert(ret.Succeeded());
00586         }
00587       }
00588     }
00589 
00590     /* Finally undo buying of new vehicles */
00591     if ((flags & DC_EXEC) == 0) {
00592       for (int i = num_units - 1; i >= 0; i--) {
00593         if (new_vehs[i] != NULL) {
00594           DoCommand(0, new_vehs[i]->index, 0, DC_EXEC, GetCmdSellVeh(new_vehs[i]));
00595           new_vehs[i] = NULL;
00596         }
00597       }
00598     }
00599 
00600     free(old_vehs);
00601     free(new_vehs);
00602     free(new_costs);
00603   } else {
00604     /* Build and refit replacement vehicle */
00605     Vehicle *new_head = NULL;
00606     cost.AddCost(BuildReplacementVehicle(old_head, &new_head, true));
00607 
00608     /* Was a new vehicle constructed? */
00609     if (cost.Succeeded() && new_head != NULL) {
00610       *nothing_to_do = false;
00611 
00612       /* The new vehicle is constructed, now take over orders and everything... */
00613       cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
00614 
00615       if (cost.Succeeded()) {
00616         /* The new vehicle is constructed, now take over cargo */
00617         if ((flags & DC_EXEC) != 0) {
00618           TransferCargo(old_head, new_head, true);
00619           *chain = new_head;
00620         }
00621 
00622         /* Sell the old vehicle */
00623         cost.AddCost(DoCommand(0, old_head->index, 0, flags, GetCmdSellVeh(old_head)));
00624       }
00625 
00626       /* If we are not in DC_EXEC undo everything */
00627       if ((flags & DC_EXEC) == 0) {
00628         DoCommand(0, new_head->index, 0, DC_EXEC, GetCmdSellVeh(new_head));
00629       }
00630     }
00631   }
00632 
00633   return cost;
00634 }
00635 
00646 CommandCost CmdAutoreplaceVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00647 {
00648   Vehicle *v = Vehicle::GetIfValid(p1);
00649   if (v == NULL) return CMD_ERROR;
00650 
00651   CommandCost ret = CheckOwnership(v->owner);
00652   if (ret.Failed()) return ret;
00653 
00654   if (!v->IsInDepot()) return CMD_ERROR;
00655   if (v->vehstatus & VS_CRASHED) return CMD_ERROR;
00656 
00657   bool free_wagon = false;
00658   if (v->type == VEH_TRAIN) {
00659     Train *t = Train::From(v);
00660     if (t->IsArticulatedPart() || t->IsRearDualheaded()) return CMD_ERROR;
00661     free_wagon = !t->IsFrontEngine();
00662     if (free_wagon && t->First()->IsFrontEngine()) return CMD_ERROR;
00663   } else {
00664     if (!v->IsPrimaryVehicle()) return CMD_ERROR;
00665   }
00666 
00667   const Company *c = Company::Get(_current_company);
00668   bool wagon_removal = c->settings.renew_keep_length;
00669 
00670   /* Test whether any replacement is set, before issuing a whole lot of commands that would end in nothing changed */
00671   Vehicle *w = v;
00672   bool any_replacements = false;
00673   while (w != NULL) {
00674     EngineID e;
00675     CommandCost cost = GetNewEngineType(w, c, e);
00676     if (cost.Failed()) return cost;
00677     any_replacements |= (e != INVALID_ENGINE);
00678     w = (!free_wagon && w->type == VEH_TRAIN ? Train::From(w)->GetNextUnit() : NULL);
00679   }
00680 
00681   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00682   bool nothing_to_do = true;
00683 
00684   if (any_replacements) {
00685     bool was_stopped = free_wagon || ((v->vehstatus & VS_STOPPED) != 0);
00686 
00687     /* Stop the vehicle */
00688     if (!was_stopped) cost.AddCost(CmdStartStopVehicle(v, true));
00689     if (cost.Failed()) return cost;
00690 
00691     assert(v->IsStoppedInDepot());
00692 
00693     /* We have to construct the new vehicle chain to test whether it is valid.
00694      * Vehicle construction needs random bits, so we have to save the random seeds
00695      * to prevent desyncs and to replay newgrf callbacks during DC_EXEC */
00696     SavedRandomSeeds saved_seeds;
00697     SaveRandomSeeds(&saved_seeds);
00698     if (free_wagon) {
00699       cost.AddCost(ReplaceFreeUnit(&v, flags & ~DC_EXEC, &nothing_to_do));
00700     } else {
00701       cost.AddCost(ReplaceChain(&v, flags & ~DC_EXEC, wagon_removal, &nothing_to_do));
00702     }
00703     RestoreRandomSeeds(saved_seeds);
00704 
00705     if (cost.Succeeded() && (flags & DC_EXEC) != 0) {
00706       CommandCost ret;
00707       if (free_wagon) {
00708         ret = ReplaceFreeUnit(&v, flags, &nothing_to_do);
00709       } else {
00710         ret = ReplaceChain(&v, flags, wagon_removal, &nothing_to_do);
00711       }
00712       assert(ret.Succeeded() && ret.GetCost() == cost.GetCost());
00713     }
00714 
00715     /* Restart the vehicle */
00716     if (!was_stopped) cost.AddCost(CmdStartStopVehicle(v, false));
00717   }
00718 
00719   if (cost.Succeeded() && nothing_to_do) cost = CommandCost(STR_ERROR_AUTOREPLACE_NOTHING_TO_DO);
00720   return cost;
00721 }
00722 
00735 CommandCost CmdSetAutoReplace(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00736 {
00737   Company *c = Company::GetIfValid(_current_company);
00738   if (c == NULL) return CMD_ERROR;
00739 
00740   EngineID old_engine_type = GB(p2, 0, 16);
00741   EngineID new_engine_type = GB(p2, 16, 16);
00742   GroupID id_g = GB(p1, 16, 16);
00743   CommandCost cost;
00744 
00745   if (Group::IsValidID(id_g) ? Group::Get(id_g)->owner != _current_company : !IsAllGroupID(id_g) && !IsDefaultGroupID(id_g)) return CMD_ERROR;
00746   if (!Engine::IsValidID(old_engine_type)) return CMD_ERROR;
00747 
00748   if (new_engine_type != INVALID_ENGINE) {
00749     if (!Engine::IsValidID(new_engine_type)) return CMD_ERROR;
00750     if (!CheckAutoreplaceValidity(old_engine_type, new_engine_type, _current_company)) return CMD_ERROR;
00751 
00752     cost = AddEngineReplacementForCompany(c, old_engine_type, new_engine_type, id_g, flags);
00753   } else {
00754     cost = RemoveEngineReplacementForCompany(c, old_engine_type, id_g, flags);
00755   }
00756 
00757   if (flags & DC_EXEC) GroupStatistics::UpdateAutoreplace(_current_company);
00758   if ((flags & DC_EXEC) && IsLocalCompany()) InvalidateAutoreplaceWindow(old_engine_type, id_g);
00759 
00760   return cost;
00761 }
00762