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 "articulated_vehicles.h"
00021 #include "core/random_func.hpp"
00022 
00023 #include "table/strings.h"
00024 
00025 extern void ChangeVehicleViewports(VehicleID from_index, VehicleID to_index);
00026 extern void ChangeVehicleNews(VehicleID from_index, VehicleID to_index);
00027 extern void ChangeVehicleViewWindow(VehicleID from_index, VehicleID to_index);
00028 
00036 static bool EnginesHaveCargoInCommon(EngineID engine_a, EngineID engine_b)
00037 {
00038   uint32 available_cargoes_a = GetUnionOfArticulatedRefitMasks(engine_a, true);
00039   uint32 available_cargoes_b = GetUnionOfArticulatedRefitMasks(engine_b, true);
00040   return (available_cargoes_a == 0 || available_cargoes_b == 0 || (available_cargoes_a & available_cargoes_b) != 0);
00041 }
00042 
00050 bool CheckAutoreplaceValidity(EngineID from, EngineID to, CompanyID company)
00051 {
00052   assert(Engine::IsValidID(from) && Engine::IsValidID(to));
00053 
00054   /* we can't replace an engine into itself (that would be autorenew) */
00055   if (from == to) return false;
00056 
00057   const Engine *e_from = Engine::Get(from);
00058   const Engine *e_to = Engine::Get(to);
00059   VehicleType type = e_from->type;
00060 
00061   /* check that the new vehicle type is available to the company and its type is the same as the original one */
00062   if (!IsEngineBuildable(to, type, company)) return false;
00063 
00064   switch (type) {
00065     case VEH_TRAIN: {
00066       /* make sure the railtypes are compatible */
00067       if ((GetRailTypeInfo(e_from->u.rail.railtype)->compatible_railtypes & GetRailTypeInfo(e_to->u.rail.railtype)->compatible_railtypes) == 0) return false;
00068 
00069       /* make sure we do not replace wagons with engines or vise versa */
00070       if ((e_from->u.rail.railveh_type == RAILVEH_WAGON) != (e_to->u.rail.railveh_type == RAILVEH_WAGON)) return false;
00071       break;
00072     }
00073 
00074     case VEH_ROAD:
00075       /* make sure that we do not replace a tram with a normal road vehicles or vise versa */
00076       if (HasBit(e_from->info.misc_flags, EF_ROAD_TRAM) != HasBit(e_to->info.misc_flags, EF_ROAD_TRAM)) return false;
00077       break;
00078 
00079     case VEH_AIRCRAFT:
00080       /* make sure that we do not replace a plane with a helicopter or vise versa */
00081       if ((e_from->u.air.subtype & AIR_CTOL) != (e_to->u.air.subtype & AIR_CTOL)) return false;
00082       break;
00083 
00084     default: break;
00085   }
00086 
00087   /* the engines needs to be able to carry the same cargo */
00088   return EnginesHaveCargoInCommon(from, to);
00089 }
00090 
00095 void CheckCargoCapacity(Vehicle *v)
00096 {
00097   assert(v == NULL || v->First() == v);
00098 
00099   for (Vehicle *src = v; src != NULL; src = src->Next()) {
00100     /* Do we need to more cargo away? */
00101     if (src->cargo.Count() <= src->cargo_cap) continue;
00102 
00103     /* We need to move a particular amount. Try that on the other vehicles. */
00104     uint to_spread = src->cargo.Count() - src->cargo_cap;
00105     for (Vehicle *dest = v; dest != NULL && to_spread != 0; dest = dest->Next()) {
00106       if (dest->cargo.Count() >= dest->cargo_cap || dest->cargo_type != src->cargo_type) continue;
00107 
00108       uint amount = min(to_spread, dest->cargo_cap - dest->cargo.Count());
00109       src->cargo.MoveTo(&dest->cargo, amount);
00110       to_spread -= amount;
00111     }
00112 
00113     /* Any left-overs will be thrown away, but not their feeder share. */
00114     src->cargo.Truncate(src->cargo_cap);
00115   }
00116 }
00117 
00124 static void TransferCargo(Vehicle *old_veh, Vehicle *new_head, bool part_of_chain)
00125 {
00126   assert(!part_of_chain || new_head->IsPrimaryVehicle());
00127   /* Loop through source parts */
00128   for (Vehicle *src = old_veh; src != NULL; src = src->Next()) {
00129     if (!part_of_chain && src->type == VEH_TRAIN && src != old_veh && src != Train::From(old_veh)->other_multiheaded_part && !src->IsArticulatedPart()) {
00130       /* Skip vehicles, which do not belong to old_veh */
00131       src = src->GetLastEnginePart();
00132       continue;
00133     }
00134     if (src->cargo_type >= NUM_CARGO || src->cargo.Count() == 0) continue;
00135 
00136     /* Find free space in the new chain */
00137     for (Vehicle *dest = new_head; dest != NULL && src->cargo.Count() > 0; dest = dest->Next()) {
00138       if (!part_of_chain && dest->type == VEH_TRAIN && dest != new_head && dest != Train::From(new_head)->other_multiheaded_part && !dest->IsArticulatedPart()) {
00139         /* Skip vehicles, which do not belong to new_head */
00140         dest = dest->GetLastEnginePart();
00141         continue;
00142       }
00143       if (dest->cargo_type != src->cargo_type) continue;
00144 
00145       uint amount = min(src->cargo.Count(), dest->cargo_cap - dest->cargo.Count());
00146       if (amount <= 0) continue;
00147 
00148       src->cargo.MoveTo(&dest->cargo, amount);
00149     }
00150   }
00151 
00152   /* Update train weight etc., the old vehicle will be sold anyway */
00153   if (part_of_chain && new_head->type == VEH_TRAIN) Train::From(new_head)->ConsistChanged(true);
00154 }
00155 
00162 static bool VerifyAutoreplaceRefitForOrders(const Vehicle *v, EngineID engine_type)
00163 {
00164 
00165   uint32 union_refit_mask_a = GetUnionOfArticulatedRefitMasks(v->engine_type, false);
00166   uint32 union_refit_mask_b = GetUnionOfArticulatedRefitMasks(engine_type, false);
00167 
00168   const Order *o;
00169   const Vehicle *u = (v->type == VEH_TRAIN) ? v->First() : v;
00170   FOR_VEHICLE_ORDERS(u, o) {
00171     if (!o->IsRefit() || o->IsAutoRefit()) continue;
00172     CargoID cargo_type = o->GetRefitCargo();
00173 
00174     if (!HasBit(union_refit_mask_a, cargo_type)) continue;
00175     if (!HasBit(union_refit_mask_b, cargo_type)) return false;
00176   }
00177 
00178   return true;
00179 }
00180 
00190 static CargoID GetNewCargoTypeForReplace(Vehicle *v, EngineID engine_type, bool part_of_chain)
00191 {
00192   uint32 available_cargo_types, union_mask;
00193   GetArticulatedRefitMasks(engine_type, true, &union_mask, &available_cargo_types);
00194 
00195   if (union_mask == 0) return CT_NO_REFIT; // Don't try to refit an engine with no cargo capacity
00196 
00197   CargoID cargo_type;
00198   if (IsArticulatedVehicleCarryingDifferentCargoes(v, &cargo_type)) return CT_INVALID; // We cannot refit to mixed cargoes in an automated way
00199 
00200   if (cargo_type == CT_INVALID) {
00201     if (v->type != VEH_TRAIN) return CT_NO_REFIT; // If the vehicle does not carry anything at all, every replacement is fine.
00202 
00203     if (!part_of_chain) return CT_NO_REFIT;
00204 
00205     /* the old engine didn't have cargo capacity, but the new one does
00206      * now we will figure out what cargo the train is carrying and refit to fit this */
00207 
00208     for (v = v->First(); v != NULL; v = v->Next()) {
00209       if (!v->GetEngine()->CanCarryCargo()) continue;
00210       /* Now we found a cargo type being carried on the train and we will see if it is possible to carry to this one */
00211       if (HasBit(available_cargo_types, v->cargo_type)) return v->cargo_type;
00212     }
00213 
00214     return CT_NO_REFIT; // We failed to find a cargo type on the old vehicle and we will not refit the new one
00215   } else {
00216     if (!HasBit(available_cargo_types, cargo_type)) return CT_INVALID; // We can't refit the vehicle to carry the cargo we want
00217 
00218     if (part_of_chain && !VerifyAutoreplaceRefitForOrders(v, engine_type)) return CT_INVALID; // Some refit orders lose their effect
00219 
00220     return cargo_type;
00221   }
00222 }
00223 
00232 static CommandCost GetNewEngineType(const Vehicle *v, const Company *c, bool always_replace, EngineID &e)
00233 {
00234   assert(v->type != VEH_TRAIN || !v->IsArticulatedPart());
00235 
00236   e = INVALID_ENGINE;
00237 
00238   if (v->type == VEH_TRAIN && Train::From(v)->IsRearDualheaded()) {
00239     /* we build the rear ends of multiheaded trains with the front ones */
00240     return CommandCost();
00241   }
00242 
00243   bool replace_when_old;
00244   e = EngineReplacementForCompany(c, v->engine_type, v->group_id, &replace_when_old);
00245   if (!always_replace && replace_when_old && !v->NeedsAutorenewing(c, false)) e = INVALID_ENGINE;
00246 
00247   /* Autoreplace, if engine is available */
00248   if (e != INVALID_ENGINE && IsEngineBuildable(e, v->type, _current_company)) {
00249     return CommandCost();
00250   }
00251 
00252   /* Autorenew if needed */
00253   if (v->NeedsAutorenewing(c)) e = v->engine_type;
00254 
00255   /* Nothing to do or all is fine? */
00256   if (e == INVALID_ENGINE || IsEngineBuildable(e, v->type, _current_company)) return CommandCost();
00257 
00258   /* The engine we need is not available. Report error to user */
00259   return CommandCost(STR_ERROR_RAIL_VEHICLE_NOT_AVAILABLE + v->type);
00260 }
00261 
00270 static CommandCost BuildReplacementVehicle(Vehicle *old_veh, Vehicle **new_vehicle, bool part_of_chain)
00271 {
00272   *new_vehicle = NULL;
00273 
00274   /* Shall the vehicle be replaced? */
00275   const Company *c = Company::Get(_current_company);
00276   EngineID e;
00277   CommandCost cost = GetNewEngineType(old_veh, c, true, e);
00278   if (cost.Failed()) return cost;
00279   if (e == INVALID_ENGINE) return CommandCost(); // neither autoreplace is set, nor autorenew is triggered
00280 
00281   /* Does it need to be refitted */
00282   CargoID refit_cargo = GetNewCargoTypeForReplace(old_veh, e, part_of_chain);
00283   if (refit_cargo == CT_INVALID) return CommandCost(); // incompatible cargoes
00284 
00285   /* Build the new vehicle */
00286   cost = DoCommand(old_veh->tile, e, 0, DC_EXEC | DC_AUTOREPLACE, GetCmdBuildVeh(old_veh));
00287   if (cost.Failed()) return cost;
00288 
00289   Vehicle *new_veh = Vehicle::Get(_new_vehicle_id);
00290   *new_vehicle = new_veh;
00291 
00292   /* Refit the vehicle if needed */
00293   if (refit_cargo != CT_NO_REFIT) {
00294     byte subtype = GetBestFittingSubType(old_veh, new_veh, refit_cargo);
00295 
00296     cost.AddCost(DoCommand(0, new_veh->index, refit_cargo | (subtype << 8), DC_EXEC, GetCmdRefitVeh(new_veh)));
00297     assert(cost.Succeeded()); // This should be ensured by GetNewCargoTypeForReplace()
00298   }
00299 
00300   /* Try to reverse the vehicle, but do not care if it fails as the new type might not be reversible */
00301   if (new_veh->type == VEH_TRAIN && HasBit(Train::From(old_veh)->flags, VRF_REVERSE_DIRECTION)) {
00302     DoCommand(0, new_veh->index, true, DC_EXEC, CMD_REVERSE_TRAIN_DIRECTION);
00303   }
00304 
00305   return cost;
00306 }
00307 
00314 static inline CommandCost CmdStartStopVehicle(const Vehicle *v, bool evaluate_callback)
00315 {
00316   return DoCommand(0, v->index, evaluate_callback ? 1 : 0, DC_EXEC | DC_AUTOREPLACE, CMD_START_STOP_VEHICLE);
00317 }
00318 
00327 static inline CommandCost CmdMoveVehicle(const Vehicle *v, const Vehicle *after, DoCommandFlag flags, bool whole_chain)
00328 {
00329   return DoCommand(0, v->index | (whole_chain ? 1 : 0) << 20, after != NULL ? after->index : INVALID_VEHICLE, flags | DC_NO_CARGO_CAP_CHECK, CMD_MOVE_RAIL_VEHICLE);
00330 }
00331 
00338 static CommandCost CopyHeadSpecificThings(Vehicle *old_head, Vehicle *new_head, DoCommandFlag flags)
00339 {
00340   CommandCost cost = CommandCost();
00341 
00342   /* Share orders */
00343   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));
00344 
00345   /* Copy group membership */
00346   if (cost.Succeeded() && old_head != new_head) cost.AddCost(DoCommand(0, old_head->group_id, new_head->index, DC_EXEC, CMD_ADD_VEHICLE_GROUP));
00347 
00348   /* Perform start/stop check whether the new vehicle suits newgrf restrictions etc. */
00349   if (cost.Succeeded()) {
00350     /* Start the vehicle, might be denied by certain things */
00351     assert((new_head->vehstatus & VS_STOPPED) != 0);
00352     cost.AddCost(CmdStartStopVehicle(new_head, true));
00353 
00354     /* Stop the vehicle again, but do not care about evil newgrfs allowing starting but not stopping :p */
00355     if (cost.Succeeded()) cost.AddCost(CmdStartStopVehicle(new_head, false));
00356   }
00357 
00358   /* Last do those things which do never fail (resp. we do not care about), but which are not undo-able */
00359   if (cost.Succeeded() && old_head != new_head && (flags & DC_EXEC) != 0) {
00360     /* Copy other things which cannot be copied by a command and which shall not stay resetted from the build vehicle command */
00361     new_head->CopyVehicleConfigAndStatistics(old_head);
00362 
00363     /* Switch vehicle windows/news to the new vehicle, so they are not closed/deleted when the old vehicle is sold */
00364     ChangeVehicleViewports(old_head->index, new_head->index);
00365     ChangeVehicleViewWindow(old_head->index, new_head->index);
00366     ChangeVehicleNews(old_head->index, new_head->index);
00367   }
00368 
00369   return cost;
00370 }
00371 
00379 static CommandCost ReplaceFreeUnit(Vehicle **single_unit, DoCommandFlag flags, bool *nothing_to_do)
00380 {
00381   Train *old_v = Train::From(*single_unit);
00382   assert(!old_v->IsArticulatedPart() && !old_v->IsRearDualheaded());
00383 
00384   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00385 
00386   /* Build and refit replacement vehicle */
00387   Vehicle *new_v = NULL;
00388   cost.AddCost(BuildReplacementVehicle(old_v, &new_v, false));
00389 
00390   /* Was a new vehicle constructed? */
00391   if (cost.Succeeded() && new_v != NULL) {
00392     *nothing_to_do = false;
00393 
00394     if ((flags & DC_EXEC) != 0) {
00395       /* Move the new vehicle behind the old */
00396       CmdMoveVehicle(new_v, old_v, DC_EXEC, false);
00397 
00398       /* Take over cargo
00399        * Note: We do only transfer cargo from the old to the new vehicle.
00400        *       I.e. we do not transfer remaining cargo to other vehicles.
00401        *       Else you would also need to consider moving cargo to other free chains,
00402        *       or doing the same in ReplaceChain(), which would be quite troublesome.
00403        */
00404       TransferCargo(old_v, new_v, false);
00405 
00406       *single_unit = new_v;
00407     }
00408 
00409     /* Sell the old vehicle */
00410     cost.AddCost(DoCommand(0, old_v->index, 0, flags, GetCmdSellVeh(old_v)));
00411 
00412     /* If we are not in DC_EXEC undo everything */
00413     if ((flags & DC_EXEC) == 0) {
00414       DoCommand(0, new_v->index, 0, DC_EXEC, GetCmdSellVeh(new_v));
00415     }
00416   }
00417 
00418   return cost;
00419 }
00420 
00429 static CommandCost ReplaceChain(Vehicle **chain, DoCommandFlag flags, bool wagon_removal, bool *nothing_to_do)
00430 {
00431   Vehicle *old_head = *chain;
00432   assert(old_head->IsPrimaryVehicle());
00433 
00434   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00435 
00436   if (old_head->type == VEH_TRAIN) {
00437     /* Store the length of the old vehicle chain, rounded up to whole tiles */
00438     uint16 old_total_length = CeilDiv(Train::From(old_head)->gcache.cached_total_length, TILE_SIZE) * TILE_SIZE;
00439 
00440     int num_units = 0; 
00441     for (Train *w = Train::From(old_head); w != NULL; w = w->GetNextUnit()) num_units++;
00442 
00443     Train **old_vehs = CallocT<Train *>(num_units); 
00444     Train **new_vehs = CallocT<Train *>(num_units); 
00445     Money *new_costs = MallocT<Money>(num_units);   
00446 
00447     /* Collect vehicles and build replacements
00448      * Note: The replacement vehicles can only successfully build as long as the old vehicles are still in their chain */
00449     int i;
00450     Train *w;
00451     for (w = Train::From(old_head), i = 0; w != NULL; w = w->GetNextUnit(), i++) {
00452       assert(i < num_units);
00453       old_vehs[i] = w;
00454 
00455       CommandCost ret = BuildReplacementVehicle(old_vehs[i], (Vehicle**)&new_vehs[i], true);
00456       cost.AddCost(ret);
00457       if (cost.Failed()) break;
00458 
00459       new_costs[i] = ret.GetCost();
00460       if (new_vehs[i] != NULL) *nothing_to_do = false;
00461     }
00462     Train *new_head = (new_vehs[0] != NULL ? new_vehs[0] : old_vehs[0]);
00463 
00464     /* Note: When autoreplace has already failed here, old_vehs[] is not completely initialized. But it is also not needed. */
00465     if (cost.Succeeded()) {
00466       /* Separate the head, so we can start constructing the new chain */
00467       Train *second = Train::From(old_head)->GetNextUnit();
00468       if (second != NULL) cost.AddCost(CmdMoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true));
00469 
00470       assert(Train::From(new_head)->GetNextUnit() == NULL);
00471 
00472       /* Append engines to the new chain
00473        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
00474        * That way we also have less trouble when exceeding the unitnumber limit.
00475        * OTOH the vehicle attach callback is more expensive this way :s */
00476       Train *last_engine = NULL; 
00477       if (cost.Succeeded()) {
00478         for (int i = num_units - 1; i > 0; i--) {
00479           Train *append = (new_vehs[i] != NULL ? new_vehs[i] : old_vehs[i]);
00480 
00481           if (RailVehInfo(append->engine_type)->railveh_type == RAILVEH_WAGON) continue;
00482 
00483           if (new_vehs[i] != NULL) {
00484             /* Move the old engine to a separate row with DC_AUTOREPLACE. Else
00485              * moving the wagon in front may fail later due to unitnumber limit.
00486              * (We have to attach wagons without DC_AUTOREPLACE.) */
00487             CmdMoveVehicle(old_vehs[i], NULL, DC_EXEC | DC_AUTOREPLACE, false);
00488           }
00489 
00490           if (last_engine == NULL) last_engine = append;
00491           cost.AddCost(CmdMoveVehicle(append, new_head, DC_EXEC, false));
00492           if (cost.Failed()) break;
00493         }
00494         if (last_engine == NULL) last_engine = new_head;
00495       }
00496 
00497       /* When wagon removal is enabled and the new engines without any wagons are already longer than the old, we have to fail */
00498       if (cost.Succeeded() && wagon_removal && new_head->gcache.cached_total_length > old_total_length) cost = CommandCost(STR_ERROR_TRAIN_TOO_LONG_AFTER_REPLACEMENT);
00499 
00500       /* Append/insert wagons into the new vehicle chain
00501        * 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.
00502        */
00503       if (cost.Succeeded()) {
00504         for (int i = num_units - 1; i > 0; i--) {
00505           assert(last_engine != NULL);
00506           Vehicle *append = (new_vehs[i] != NULL ? new_vehs[i] : old_vehs[i]);
00507 
00508           if (RailVehInfo(append->engine_type)->railveh_type == RAILVEH_WAGON) {
00509             /* Insert wagon after 'last_engine' */
00510             CommandCost res = CmdMoveVehicle(append, last_engine, DC_EXEC, false);
00511 
00512             /* When we allow removal of wagons, either the move failing due
00513              * to the train becoming too long, or the train becoming longer
00514              * would move the vehicle to the empty vehicle chain. */
00515             if (wagon_removal && (res.Failed() ? res.GetErrorMessage() == STR_ERROR_TRAIN_TOO_LONG : new_head->gcache.cached_total_length > old_total_length)) {
00516               CmdMoveVehicle(append, NULL, DC_EXEC | DC_AUTOREPLACE, false);
00517               break;
00518             }
00519 
00520             cost.AddCost(res);
00521             if (cost.Failed()) break;
00522           } else {
00523             /* We have reached 'last_engine', continue with the next engine towards the front */
00524             assert(append == last_engine);
00525             last_engine = last_engine->GetPrevUnit();
00526           }
00527         }
00528       }
00529 
00530       /* Sell superfluous new vehicles that could not be inserted. */
00531       if (cost.Succeeded() && wagon_removal) {
00532         assert(new_head->gcache.cached_total_length <= _settings_game.vehicle.max_train_length * TILE_SIZE);
00533         for (int i = 1; i < num_units; i++) {
00534           Vehicle *wagon = new_vehs[i];
00535           if (wagon == NULL) continue;
00536           if (wagon->First() == new_head) break;
00537 
00538           assert(RailVehInfo(wagon->engine_type)->railveh_type == RAILVEH_WAGON);
00539 
00540           /* Sell wagon */
00541           CommandCost ret = DoCommand(0, wagon->index, 0, DC_EXEC, GetCmdSellVeh(wagon));
00542           assert(ret.Succeeded());
00543           new_vehs[i] = NULL;
00544 
00545           /* Revert the money subtraction when the vehicle was built.
00546            * This value is different from the sell value, esp. because of refitting */
00547           cost.AddCost(-new_costs[i]);
00548         }
00549       }
00550 
00551       /* The new vehicle chain is constructed, now take over orders and everything... */
00552       if (cost.Succeeded()) cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
00553 
00554       if (cost.Succeeded()) {
00555         /* Success ! */
00556         if ((flags & DC_EXEC) != 0 && new_head != old_head) {
00557           *chain = new_head;
00558         }
00559 
00560         /* Transfer cargo of old vehicles and sell them */
00561         for (int i = 0; i < num_units; i++) {
00562           Vehicle *w = old_vehs[i];
00563           /* Is the vehicle again part of the new chain?
00564            * Note: We cannot test 'new_vehs[i] != NULL' as wagon removal might cause to remove both */
00565           if (w->First() == new_head) continue;
00566 
00567           if ((flags & DC_EXEC) != 0) TransferCargo(w, new_head, true);
00568 
00569           /* Sell the vehicle.
00570            * Note: This might temporarly construct new trains, so use DC_AUTOREPLACE to prevent
00571            *       it from failing due to engine limits. */
00572           cost.AddCost(DoCommand(0, w->index, 0, flags | DC_AUTOREPLACE, GetCmdSellVeh(w)));
00573           if ((flags & DC_EXEC) != 0) {
00574             old_vehs[i] = NULL;
00575             if (i == 0) old_head = NULL;
00576           }
00577         }
00578 
00579         if ((flags & DC_EXEC) != 0) CheckCargoCapacity(new_head);
00580       }
00581 
00582       /* If we are not in DC_EXEC undo everything, i.e. rearrange old vehicles.
00583        * We do this from back to front, so that the head of the temporary vehicle chain does not change all the time.
00584        * Note: The vehicle attach callback is disabled here :) */
00585       if ((flags & DC_EXEC) == 0) {
00586         /* Separate the head, so we can reattach the old vehicles */
00587         Train *second = Train::From(old_head)->GetNextUnit();
00588         if (second != NULL) CmdMoveVehicle(second, NULL, DC_EXEC | DC_AUTOREPLACE, true);
00589 
00590         assert(Train::From(old_head)->GetNextUnit() == NULL);
00591 
00592         for (int i = num_units - 1; i > 0; i--) {
00593           CommandCost ret = CmdMoveVehicle(old_vehs[i], old_head, DC_EXEC | DC_AUTOREPLACE, false);
00594           assert(ret.Succeeded());
00595         }
00596       }
00597     }
00598 
00599     /* Finally undo buying of new vehicles */
00600     if ((flags & DC_EXEC) == 0) {
00601       for (int i = num_units - 1; i >= 0; i--) {
00602         if (new_vehs[i] != NULL) {
00603           DoCommand(0, new_vehs[i]->index, 0, DC_EXEC, GetCmdSellVeh(new_vehs[i]));
00604           new_vehs[i] = NULL;
00605         }
00606       }
00607     }
00608 
00609     free(old_vehs);
00610     free(new_vehs);
00611     free(new_costs);
00612   } else {
00613     /* Build and refit replacement vehicle */
00614     Vehicle *new_head = NULL;
00615     cost.AddCost(BuildReplacementVehicle(old_head, &new_head, true));
00616 
00617     /* Was a new vehicle constructed? */
00618     if (cost.Succeeded() && new_head != NULL) {
00619       *nothing_to_do = false;
00620 
00621       /* The new vehicle is constructed, now take over orders and everything... */
00622       cost.AddCost(CopyHeadSpecificThings(old_head, new_head, flags));
00623 
00624       if (cost.Succeeded()) {
00625         /* The new vehicle is constructed, now take over cargo */
00626         if ((flags & DC_EXEC) != 0) {
00627           TransferCargo(old_head, new_head, true);
00628           *chain = new_head;
00629         }
00630 
00631         /* Sell the old vehicle */
00632         cost.AddCost(DoCommand(0, old_head->index, 0, flags, GetCmdSellVeh(old_head)));
00633       }
00634 
00635       /* If we are not in DC_EXEC undo everything */
00636       if ((flags & DC_EXEC) == 0) {
00637         DoCommand(0, new_head->index, 0, DC_EXEC, GetCmdSellVeh(new_head));
00638       }
00639     }
00640   }
00641 
00642   return cost;
00643 }
00644 
00655 CommandCost CmdAutoreplaceVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00656 {
00657   Vehicle *v = Vehicle::GetIfValid(p1);
00658   if (v == NULL) return CMD_ERROR;
00659 
00660   CommandCost ret = CheckOwnership(v->owner);
00661   if (ret.Failed()) return ret;
00662 
00663   if (!v->IsChainInDepot()) return CMD_ERROR;
00664   if (v->vehstatus & VS_CRASHED) return CMD_ERROR;
00665 
00666   bool free_wagon = false;
00667   if (v->type == VEH_TRAIN) {
00668     Train *t = Train::From(v);
00669     if (t->IsArticulatedPart() || t->IsRearDualheaded()) return CMD_ERROR;
00670     free_wagon = !t->IsFrontEngine();
00671     if (free_wagon && t->First()->IsFrontEngine()) return CMD_ERROR;
00672   } else {
00673     if (!v->IsPrimaryVehicle()) return CMD_ERROR;
00674   }
00675 
00676   const Company *c = Company::Get(_current_company);
00677   bool wagon_removal = c->settings.renew_keep_length;
00678 
00679   /* Test whether any replacement is set, before issuing a whole lot of commands that would end in nothing changed */
00680   Vehicle *w = v;
00681   bool any_replacements = false;
00682   while (w != NULL) {
00683     EngineID e;
00684     CommandCost cost = GetNewEngineType(w, c, false, e);
00685     if (cost.Failed()) return cost;
00686     any_replacements |= (e != INVALID_ENGINE);
00687     w = (!free_wagon && w->type == VEH_TRAIN ? Train::From(w)->GetNextUnit() : NULL);
00688   }
00689 
00690   CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
00691   bool nothing_to_do = true;
00692 
00693   if (any_replacements) {
00694     bool was_stopped = free_wagon || ((v->vehstatus & VS_STOPPED) != 0);
00695 
00696     /* Stop the vehicle */
00697     if (!was_stopped) cost.AddCost(CmdStartStopVehicle(v, true));
00698     if (cost.Failed()) return cost;
00699 
00700     assert(free_wagon || v->IsStoppedInDepot());
00701 
00702     /* We have to construct the new vehicle chain to test whether it is valid.
00703      * Vehicle construction needs random bits, so we have to save the random seeds
00704      * to prevent desyncs and to replay newgrf callbacks during DC_EXEC */
00705     SavedRandomSeeds saved_seeds;
00706     SaveRandomSeeds(&saved_seeds);
00707     if (free_wagon) {
00708       cost.AddCost(ReplaceFreeUnit(&v, flags & ~DC_EXEC, &nothing_to_do));
00709     } else {
00710       cost.AddCost(ReplaceChain(&v, flags & ~DC_EXEC, wagon_removal, &nothing_to_do));
00711     }
00712     RestoreRandomSeeds(saved_seeds);
00713 
00714     if (cost.Succeeded() && (flags & DC_EXEC) != 0) {
00715       CommandCost ret;
00716       if (free_wagon) {
00717         ret = ReplaceFreeUnit(&v, flags, &nothing_to_do);
00718       } else {
00719         ret = ReplaceChain(&v, flags, wagon_removal, &nothing_to_do);
00720       }
00721       assert(ret.Succeeded() && ret.GetCost() == cost.GetCost());
00722     }
00723 
00724     /* Restart the vehicle */
00725     if (!was_stopped) cost.AddCost(CmdStartStopVehicle(v, false));
00726   }
00727 
00728   if (cost.Succeeded() && nothing_to_do) cost = CommandCost(STR_ERROR_AUTOREPLACE_NOTHING_TO_DO);
00729   return cost;
00730 }
00731 
00745 CommandCost CmdSetAutoReplace(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00746 {
00747   Company *c = Company::GetIfValid(_current_company);
00748   if (c == NULL) return CMD_ERROR;
00749 
00750   EngineID old_engine_type = GB(p2, 0, 16);
00751   EngineID new_engine_type = GB(p2, 16, 16);
00752   GroupID id_g = GB(p1, 16, 16);
00753   CommandCost cost;
00754 
00755   if (Group::IsValidID(id_g) ? Group::Get(id_g)->owner != _current_company : !IsAllGroupID(id_g) && !IsDefaultGroupID(id_g)) return CMD_ERROR;
00756   if (!Engine::IsValidID(old_engine_type)) return CMD_ERROR;
00757 
00758   if (new_engine_type != INVALID_ENGINE) {
00759     if (!Engine::IsValidID(new_engine_type)) return CMD_ERROR;
00760     if (!CheckAutoreplaceValidity(old_engine_type, new_engine_type, _current_company)) return CMD_ERROR;
00761 
00762     cost = AddEngineReplacementForCompany(c, old_engine_type, new_engine_type, id_g, HasBit(p1, 0), flags);
00763   } else {
00764     cost = RemoveEngineReplacementForCompany(c, old_engine_type, id_g, flags);
00765   }
00766 
00767   if (flags & DC_EXEC) {
00768     GroupStatistics::UpdateAutoreplace(_current_company);
00769     SetWindowClassesDirty(GetWindowClassForVehicleType(Engine::Get(old_engine_type)->type));
00770   }
00771   if ((flags & DC_EXEC) && IsLocalCompany()) InvalidateAutoreplaceWindow(old_engine_type, id_g);
00772 
00773   return cost;
00774 }
00775