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 #include "safeguards.h"
  19
  20 /** The pool of autoreplace "orders". */
  21 EngineRenewPool _enginerenew_pool("EngineRenew");
  22 INSTANTIATE_POOL_METHODS(EngineRenew)
  23
  24 /**
  25  * Retrieves the EngineRenew that specifies the replacement of the given
  26  * engine type from the given renewlist
  27  */
  28 static EngineRenew *GetEngineReplacement(EngineRenewList erl, EngineID engine, GroupID group)
  29 {
  30         EngineRenew *er = (EngineRenew *)erl;
  31
  32         while (er != NULL) {
  33                 if (er->from == engine && GroupIsInGroup(group, er->group_id)) return er;
  34                 er = er->next;
  35         }
  36         return NULL;
  37 }
  38
  39 /**
  40  * Remove all engine replacement settings for the company.
  41  * @param  erl The renewlist for a given company.
  42  * @return The new renewlist for the company.
  43  */
  44 void RemoveAllEngineReplacement(EngineRenewList *erl)
  45 {
  46         EngineRenew *er = (EngineRenew *)(*erl);
  47         EngineRenew *next;
  48
  49         while (er != NULL) {
  50                 next = er->next;
  51                 delete er;
  52                 er = next;
  53         }
  54         *erl = NULL; // Empty list
  55 }
  56
  57 /**
  58  * Retrieve the engine replacement in a given renewlist for an original engine type.
  59  * @param erl The renewlist to search in.
  60  * @param engine Engine type to be replaced.
  61  * @param group The group related to this replacement.
  62  * @param[out] replace_when_old Set to true if the replacement should be done when old.
  63  * @return The engine type to replace with, or INVALID_ENGINE if no
  64  * replacement is in the list.
  65  */
  66 EngineID EngineReplacement(EngineRenewList erl, EngineID engine, GroupID group, bool *replace_when_old)
  67 {
  68         const EngineRenew *er = GetEngineReplacement(erl, engine, group);
  69         if (er == NULL && (group == DEFAULT_GROUP || (Group::IsValidID(group) && !Group::Get(group)->replace_protection))) {
  70                 /* We didn't find anything useful in the vehicle's own group so we will try ALL_GROUP */
  71                 er = GetEngineReplacement(erl, engine, ALL_GROUP);
  72         }
  73         if (replace_when_old != NULL) *replace_when_old = er == NULL ? false : er->replace_when_old;
  74         return er == NULL ? INVALID_ENGINE : er->to;
  75 }
  76
  77 /**
  78  * Add an engine replacement to the given renewlist.
  79  * @param erl The renewlist to add to.
  80  * @param old_engine The original engine type.
  81  * @param new_engine The replacement engine type.
  82  * @param group The group related to this replacement.
  83  * @param replace_when_old Replace when old or always?
  84  * @param flags The calling command flags.
  85  * @return 0 on success, CMD_ERROR on failure.
  86  */
  87 CommandCost AddEngineReplacement(EngineRenewList *erl, EngineID old_engine, EngineID new_engine, GroupID group, bool replace_when_old, DoCommandFlag flags)
  88 {
  89         /* Check if the old vehicle is already in the list */
  90         EngineRenew *er = GetEngineReplacement(*erl, old_engine, group);
  91         if (er != NULL) {
  92                 if (flags & DC_EXEC) {
  93                         er->to = new_engine;
  94                         er->replace_when_old = replace_when_old;
  95                 }
  96                 return CommandCost();
  97         }
  98
  99         if (!EngineRenew::CanAllocateItem()) return CMD_ERROR;
 100
 101         if (flags & DC_EXEC) {
 102                 er = new EngineRenew(old_engine, new_engine);
 103                 er->group_id = group;
 104                 er->replace_when_old = replace_when_old;
 105
 106                 /* Insert before the first element */
 107                 er->next = (EngineRenew *)(*erl);
 108                 *erl = (EngineRenewList)er;
 109         }
 110
 111         return CommandCost();
 112 }
 113
 114 /**
 115  * Remove an engine replacement from a given renewlist.
 116  * @param erl The renewlist from which to remove the replacement
 117  * @param engine The original engine type.
 118  * @param group The group related to this replacement.
 119  * @param flags The calling command flags.
 120  * @return 0 on success, CMD_ERROR on failure.
 121  */
 122 CommandCost RemoveEngineReplacement(EngineRenewList *erl, EngineID engine, GroupID group, DoCommandFlag flags)
 123 {
 124         EngineRenew *er = (EngineRenew *)(*erl);
 125         EngineRenew *prev = NULL;
 126
 127         while (er != NULL) {
 128                 if (er->from == engine && er->group_id == group) {
 129                         if (flags & DC_EXEC) {
 130                                 if (prev == NULL) { // First element
 131                                         /* The second becomes the new first element */
 132                                         *erl = (EngineRenewList)er->next;
 133                                 } else {
 134                                         /* Cut this element out */
 135                                         prev->next = er->next;
 136                                 }
 137                                 delete er;
 138                         }
 139                         return CommandCost();
 140                 }
 141                 prev = er;
 142                 er = er->next;
 143         }
 144
 145         return CMD_ERROR;
 146 }