src/autoreplace.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * 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.
   6  * 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.
   7  * 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/>.
   8  */
   9
  10 /** @file autoreplace.cpp Management of replacement lists. */
  11
  12 #include "stdafx.h"
  13 #include "command_func.h"
  14 #include "group.h"
  15 #include "autoreplace_base.h"
  16 #include "core/pool_func.hpp"
  17
  18 /** The pool of autoreplace "orders". */
  19 template<> EngineRenew::Pool EngineRenew::PoolItem::pool ("EngineRenew");
  20 INSTANTIATE_POOL_METHODS(EngineRenew)
  21
  22 /**
  23  * Retrieves the EngineRenew that specifies the replacement of the given
  24  * engine type from the given renewlist
  25  */
  26 static EngineRenew *GetEngineReplacement(EngineRenewList erl, EngineID engine, GroupID group)
  27 {
  28         EngineRenew *er = (EngineRenew *)erl;
  29
  30         while (er != NULL) {
  31                 if (er->from == engine && er->group_id == group) return er;
  32                 er = er->next;
  33         }
  34         return NULL;
  35 }
  36
  37 /**
  38  * Remove all engine replacement settings for the company.
  39  * @param  erl The renewlist for a given company.
  40  * @return The new renewlist for the company.
  41  */
  42 void RemoveAllEngineReplacement(EngineRenewList *erl)
  43 {
  44         EngineRenew *er = (EngineRenew *)(*erl);
  45         EngineRenew *next;
  46
  47         while (er != NULL) {
  48                 next = er->next;
  49                 delete er;
  50                 er = next;
  51         }
  52         *erl = NULL; // Empty list
  53 }
  54
  55 /**
  56  * Retrieve the engine replacement in a given renewlist for an original engine type.
  57  * @param erl The renewlist to search in.
  58  * @param engine Engine type to be replaced.
  59  * @param group The group related to this replacement.
  60  * @param[out] replace_when_old Set to true if the replacement should be done when old.
  61  * @return The engine type to replace with, or INVALID_ENGINE if no
  62  * replacement is in the list.
  63  */
  64 EngineID EngineReplacement(EngineRenewList erl, EngineID engine, GroupID group, bool *replace_when_old)
  65 {
  66         const EngineRenew *er = GetEngineReplacement(erl, engine, group);
  67         if (er == NULL && (group == DEFAULT_GROUP || (Group::IsValidID(group) && !Group::Get(group)->replace_protection))) {
  68                 /* We didn't find anything useful in the vehicle's own group so we will try ALL_GROUP */
  69                 er = GetEngineReplacement(erl, engine, ALL_GROUP);
  70         }
  71         if (replace_when_old != NULL) *replace_when_old = er == NULL ? false : er->replace_when_old;
  72         return er == NULL ? INVALID_ENGINE : er->to;
  73 }
  74
  75 /**
  76  * Add an engine replacement to the given renewlist.
  77  * @param erl The renewlist to add to.
  78  * @param old_engine The original engine type.
  79  * @param new_engine The replacement engine type.
  80  * @param group The group related to this replacement.
  81  * @param replace_when_old Replace when old or always?
  82  * @param flags The calling command flags.
  83  * @return 0 on success, CMD_ERROR on failure.
  84  */
  85 CommandCost AddEngineReplacement(EngineRenewList *erl, EngineID old_engine, EngineID new_engine, GroupID group, bool replace_when_old, DoCommandFlag flags)
  86 {
  87         /* Check if the old vehicle is already in the list */
  88         EngineRenew *er = GetEngineReplacement(*erl, old_engine, group);
  89         if (er != NULL) {
  90                 if (flags & DC_EXEC) {
  91                         er->to = new_engine;
  92                         er->replace_when_old = replace_when_old;
  93                 }
  94                 return CommandCost();
  95         }
  96
  97         if (!EngineRenew::CanAllocateItem()) return CMD_ERROR;
  98
  99         if (flags & DC_EXEC) {
 100                 er = new EngineRenew(old_engine, new_engine);
 101                 er->group_id = group;
 102                 er->replace_when_old = replace_when_old;
 103
 104                 /* Insert before the first element */
 105                 er->next = (EngineRenew *)(*erl);
 106                 *erl = (EngineRenewList)er;
 107         }
 108
 109         return CommandCost();
 110 }
 111
 112 /**
 113  * Remove an engine replacement from a given renewlist.
 114  * @param erl The renewlist from which to remove the replacement
 115  * @param engine The original engine type.
 116  * @param group The group related to this replacement.
 117  * @param flags The calling command flags.
 118  * @return 0 on success, CMD_ERROR on failure.
 119  */
 120 CommandCost RemoveEngineReplacement(EngineRenewList *erl, EngineID engine, GroupID group, DoCommandFlag flags)
 121 {
 122         EngineRenew *er = (EngineRenew *)(*erl);
 123         EngineRenew *prev = NULL;
 124
 125         while (er != NULL) {
 126                 if (er->from == engine && er->group_id == group) {
 127                         if (flags & DC_EXEC) {
 128                                 if (prev == NULL) { // First element
 129                                         /* The second becomes the new first element */
 130                                         *erl = (EngineRenewList)er->next;
 131                                 } else {
 132                                         /* Cut this element out */
 133                                         prev->next = er->next;
 134                                 }
 135                                 delete er;
 136                         }
 137                         return CommandCost();
 138                 }
 139                 prev = er;
 140                 er = er->next;
 141         }
 142
 143         return CMD_ERROR;
 144 }