autoreplace.cpp

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00001 /* $Id: autoreplace.cpp 24136 2012-04-17 19:44:02Z michi_cc $ */
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 "command_func.h"
00014 #include "group.h"
00015 #include "autoreplace_base.h"
00016 #include "core/pool_func.hpp"
00017 
00019 EngineRenewPool _enginerenew_pool("EngineRenew");
00020 INSTANTIATE_POOL_METHODS(EngineRenew)
00021 
00022 
00026 static EngineRenew *GetEngineReplacement(EngineRenewList erl, EngineID engine, GroupID group)
00027 {
00028   EngineRenew *er = (EngineRenew *)erl;
00029 
00030   while (er != NULL) {
00031     if (er->from == engine && er->group_id == group) return er;
00032     er = er->next;
00033   }
00034   return NULL;
00035 }
00036 
00042 void RemoveAllEngineReplacement(EngineRenewList *erl)
00043 {
00044   EngineRenew *er = (EngineRenew *)(*erl);
00045   EngineRenew *next;
00046 
00047   while (er != NULL) {
00048     next = er->next;
00049     delete er;
00050     er = next;
00051   }
00052   *erl = NULL; // Empty list
00053 }
00054 
00064 EngineID EngineReplacement(EngineRenewList erl, EngineID engine, GroupID group, bool *replace_when_old)
00065 {
00066   const EngineRenew *er = GetEngineReplacement(erl, engine, group);
00067   if (er == NULL && (group == DEFAULT_GROUP || (Group::IsValidID(group) && !Group::Get(group)->replace_protection))) {
00068     /* We didn't find anything useful in the vehicle's own group so we will try ALL_GROUP */
00069     er = GetEngineReplacement(erl, engine, ALL_GROUP);
00070   }
00071   if (replace_when_old != NULL) *replace_when_old = er == NULL ? false : er->replace_when_old;
00072   return er == NULL ? INVALID_ENGINE : er->to;
00073 }
00074 
00085 CommandCost AddEngineReplacement(EngineRenewList *erl, EngineID old_engine, EngineID new_engine, GroupID group, bool replace_when_old, DoCommandFlag flags)
00086 {
00087   /* Check if the old vehicle is already in the list */
00088   EngineRenew *er = GetEngineReplacement(*erl, old_engine, group);
00089   if (er != NULL) {
00090     if (flags & DC_EXEC) er->to = new_engine;
00091     return CommandCost();
00092   }
00093 
00094   if (!EngineRenew::CanAllocateItem()) return CMD_ERROR;
00095 
00096   if (flags & DC_EXEC) {
00097     er = new EngineRenew(old_engine, new_engine);
00098     er->group_id = group;
00099     er->replace_when_old = replace_when_old;
00100 
00101     /* Insert before the first element */
00102     er->next = (EngineRenew *)(*erl);
00103     *erl = (EngineRenewList)er;
00104   }
00105 
00106   return CommandCost();
00107 }
00108 
00117 CommandCost RemoveEngineReplacement(EngineRenewList *erl, EngineID engine, GroupID group, DoCommandFlag flags)
00118 {
00119   EngineRenew *er = (EngineRenew *)(*erl);
00120   EngineRenew *prev = NULL;
00121 
00122   while (er != NULL) {
00123     if (er->from == engine && er->group_id == group) {
00124       if (flags & DC_EXEC) {
00125         if (prev == NULL) { // First element
00126           /* The second becomes the new first element */
00127           *erl = (EngineRenewList)er->next;
00128         } else {
00129           /* Cut this element out */
00130           prev->next = er->next;
00131         }
00132         delete er;
00133       }
00134       return CommandCost();
00135     }
00136     prev = er;
00137     er = er->next;
00138   }
00139 
00140   return CMD_ERROR;
00141 }