src/subsidy_base.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * 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.
   4  * 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.
   5  * 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/>.
   6  */
   7
   8 /** @file subsidy_base.h %Subsidy base class. */
   9
  10 #ifndef SUBSIDY_BASE_H
  11 #define SUBSIDY_BASE_H
  12
  13 #include "cargo_type.h"
  14 #include "company_type.h"
  15 #include "subsidy_type.h"
  16 #include "core/pool_type.hpp"
  17
  18 typedef Pool<Subsidy, SubsidyID, 1, 256> SubsidyPool;
  19 extern SubsidyPool _subsidy_pool;
  20
  21 /** Struct about subsidies, offered and awarded */
  22 struct Subsidy : SubsidyPool::PoolItem<&_subsidy_pool> {
  23         CargoID cargo_type;  ///< Cargo type involved in this subsidy, INVALID_CARGO for invalid subsidy
  24         uint16_t remaining;    ///< Remaining months when this subsidy is valid
  25         CompanyID awarded;   ///< Subsidy is awarded to this company; INVALID_COMPANY if it's not awarded to anyone
  26         SourceType src_type; ///< Source of subsidised path (SourceType::Industry or SourceType::Town)
  27         SourceType dst_type; ///< Destination of subsidised path (SourceType::Industry or SourceType::Town)
  28         SourceID src;        ///< Index of source. Either TownID or IndustryID
  29         SourceID dst;        ///< Index of destination. Either TownID or IndustryID
  30
  31         /**
  32          * We need an (empty) constructor so struct isn't zeroed (as C++ standard states)
  33          */
  34         inline Subsidy() { }
  35
  36         /**
  37          * (Empty) destructor has to be defined else operator delete might be called with nullptr parameter
  38          */
  39         inline ~Subsidy() { }
  40
  41         /**
  42          * Tests whether this subsidy has been awarded to someone
  43          * @return is this subsidy awarded?
  44          */
  45         inline bool IsAwarded() const
  46         {
  47                 return this->awarded != INVALID_COMPANY;
  48         }
  49
  50         void AwardTo(CompanyID company);
  51 };
  52
  53 /** Constants related to subsidies */
  54 static const uint SUBSIDY_OFFER_MONTHS         =  12; ///< Duration of subsidy offer
  55 static const uint SUBSIDY_PAX_MIN_POPULATION   = 400; ///< Min. population of towns for subsidised pax route
  56 static const uint SUBSIDY_CARGO_MIN_POPULATION = 900; ///< Min. population of destination town for cargo route
  57 static const uint SUBSIDY_MAX_PCT_TRANSPORTED  =  42; ///< Subsidy will be created only for towns/industries with less % transported
  58 static const uint SUBSIDY_MAX_DISTANCE         =  70; ///< Max. length of subsidised route (DistanceManhattan)
  59 static const uint SUBSIDY_TOWN_CARGO_RADIUS    =   6; ///< Extent of a tile area around town center when scanning for town cargo acceptance and production (6 ~= min catchmement + min station / 2)
  60
  61 /** Types of subsidy news messages, which determine how the date is printed and whether to use singular or plural cargo names */
  62 enum class SubsidyDecodeParamType {
  63         NewsOffered   = 0, ///< News item for an offered subsidy
  64         NewsAwarded   = 1, ///< News item for an awarded subsidy
  65         NewsWithdrawn = 2, ///< News item for a subsidy offer withdrawn, or expired subsidy
  66         Gui           = 3, ///< Subsidies listed in the Subsidy GUI
  67 };
  68
  69 #endif /* SUBSIDY_BASE_H */