Initialize with OpenTTD 1.9.3

src/date_func.h

@@ -0,0 +1,37 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * 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.
+ * 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.
+ * 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/>.
+ */
+
+/** @file date_func.h Functions related to dates. */
+
+#ifndef DATE_FUNC_H
+#define DATE_FUNC_H
+
+#include "date_type.h"
+
+extern Year      _cur_year;
+extern Month     _cur_month;
+extern Date      _date;
+extern DateFract _date_fract;
+extern uint16 _tick_counter;
+
+void SetDate(Date date, DateFract fract);
+void ConvertDateToYMD(Date date, YearMonthDay *ymd);
+Date ConvertYMDToDate(Year year, Month month, Day day);
+
+/**
+ * Checks whether the given year is a leap year or not.
+ * @param yr The year to check.
+ * @return True if \c yr is a leap year, otherwise false.
+ */
+static inline bool IsLeapYear(Year yr)
+{
+	return yr % 4 == 0 && (yr % 100 != 0 || yr % 400 == 0);
+}
+
+#endif /* DATE_FUNC_H */