src/timer/timer_game_realtime.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 timer_game_realtime.h Definition of the real time game-timer */
   9
  10 #ifndef TIMER_GAME_REALTIME_H
  11 #define TIMER_GAME_REALTIME_H
  12
  13 #include <chrono>
  14
  15 /**
  16  * Timer that represents real time for game-related purposes.
  17  *
  18  * For pausing, there are several modes:
  19  * - Continue to tick during pause (PeriodFlags::ALWAYS).
  20  * - Stop ticking when paused (PeriodFlags::UNPAUSED).
  21  * - Only tick when unpaused or when there was a Command executed recently (recently: since last autosave) (PeriodFlags::AUTOSAVE).
  22  *
  23  * @note The lowest possible interval is 1ms, although realistic the lowest
  24  * interval is 27ms. This timer is only updated when the game-thread makes
  25  * a tick, which happens every 27ms.
  26  * @note Callbacks are executed in the game-thread.
  27  */
  28 class TimerGameRealtime {
  29 public:
  30         enum PeriodFlags {
  31                 ALWAYS, ///< Always run, even when paused.
  32                 UNPAUSED, ///< Only run when not paused.
  33                 AUTOSAVE, ///< Only run when not paused or there was a Command executed recently.
  34         };
  35
  36         struct TPeriod {
  37                 std::chrono::milliseconds period;
  38                 PeriodFlags flag;
  39
  40                 TPeriod(std::chrono::milliseconds period, PeriodFlags flag) : period(period), flag(flag) {}
  41
  42                 bool operator < (const TPeriod &other) const
  43                 {
  44                         if (this->flag != other.flag) return this->flag < other.flag;
  45                         return this->period < other.period;
  46                 }
  47
  48                 bool operator == (const TPeriod &other) const
  49                 {
  50                         return this->flag == other.flag && this->period == other.period;
  51                 }
  52         };
  53         using TElapsed = std::chrono::milliseconds;
  54         struct TStorage {
  55                 std::chrono::milliseconds elapsed;
  56         };
  57 };
  58
  59 #endif /* TIMER_GAME_REALTIME_H */