src/date_func.h

   1 /* $Id: date_func.h 22411 2011-05-02 17:42:12Z rubidium $ */
   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 date_func.h Functions related to dates. */
  11
  12 #ifndef DATE_FUNC_H
  13 #define DATE_FUNC_H
  14
  15 #include "date_type.h"
  16
  17 extern Year      _cur_year;
  18 extern Month     _cur_month;
  19 extern YearMonthDay _cur_date_ymd;
  20 extern Date      _date;
  21 extern DateFract _date_fract;
  22 extern uint16 _tick_counter;
  23
  24 void SetDate(Date date, DateFract fract);
  25 void ConvertDateToYMD(Date date, YearMonthDay *ymd);
  26 Date ConvertYMDToDate(Year year, Month month, Day day);
  27 Ticks GetCurrentTickCount();
  28
  29 /**
  30  * Checks whether the given year is a leap year or not.
  31  * @param yr The year to check.
  32  * @return True if \c yr is a leap year, otherwise false.
  33  */
  34 static inline bool IsLeapYear(Year yr)
  35 {
  36         return yr % 4 == 0 && (yr % 100 != 0 || yr % 400 == 0);
  37 }
  38
  39 #endif /* DATE_FUNC_H */