mirror of
https://github.com/JGRennison/OpenTTD-patches.git
synced 2024-10-31 15:20:10 +00:00
60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
/* $Id$ */
|
|
|
|
#ifndef DATE_H
|
|
#define DATE_H
|
|
|
|
/**
|
|
* 1 day is 74 ticks; _date_fract used to be uint16 and incremented by 885. On
|
|
* an overflow the new day begun and 65535 / 885 = 74.
|
|
* 1 tick is approximately 30 ms.
|
|
* 1 day is thus about 2 seconds (74 * 30 = 2220) on a machine that can run OpenTTD normally
|
|
*/
|
|
#define DAY_TICKS 74
|
|
|
|
/*
|
|
* ORIGINAL_BASE_YEAR, ORIGINAL_MAX_YEAR and DAYS_TILL_ORIGINAL_BASE_YEAR are
|
|
* primarily used for loading newgrf and savegame data and returning some
|
|
* newgrf (callback) functions that were in the original (TTD) inherited
|
|
* format, where '_date == 0' meant that it was 1920-01-01.
|
|
*/
|
|
|
|
/** The minimum starting year/base year of the original TTD */
|
|
#define ORIGINAL_BASE_YEAR 1920
|
|
/** The maximum year of the original TTD */
|
|
#define ORIGINAL_MAX_YEAR 2090
|
|
|
|
/**
|
|
* The offset in days from the '_date == 0' till
|
|
* 'ConvertYMDToDate(ORIGINAL_BASE_YEAR, 0, 1)'
|
|
*/
|
|
#define DAYS_TILL_ORIGINAL_BASE_YEAR (365 * ORIGINAL_BASE_YEAR + ORIGINAL_BASE_YEAR / 4 - ORIGINAL_BASE_YEAR / 100 + ORIGINAL_BASE_YEAR / 400)
|
|
|
|
/* The absolute minimum & maximum years in OTTD */
|
|
#define MIN_YEAR 0
|
|
/* MAX_YEAR, nicely rounded value of the number of years that can
|
|
* be encoded in a single 32 bits date, about 2^31 / 366 years. */
|
|
#define MAX_YEAR 5000000
|
|
|
|
/* Year and Date are defined elsewhere */
|
|
typedef uint8 Month;
|
|
typedef uint8 Day;
|
|
typedef uint16 DateFract;
|
|
|
|
typedef struct YearMonthDay {
|
|
Year year;
|
|
Month month;
|
|
Day day;
|
|
} YearMonthDay;
|
|
|
|
extern Year _cur_year;
|
|
extern Month _cur_month;
|
|
extern Date _date;
|
|
extern DateFract _date_fract;
|
|
|
|
|
|
void SetDate(Date date);
|
|
void ConvertDateToYMD(Date date, YearMonthDay *ymd);
|
|
Date ConvertYMDToDate(Year year, Month month, Day day);
|
|
|
|
#endif /* DATE_H */
|