OpenTTD/src/date.h
rubidium 66bbf336c6 (svn r7759) -Merge: makefile rewrite. This merge features:
- A proper ./configure, so everything needs to be configured only once, not for every make.
 - Usage of makedepend when available. This greatly reduces the time needed for generating the dependencies.
 - A generator for all project files. There is a single file with sources, which is used to generate Makefiles and the project files for MSVC.
 - Proper support for OSX universal binaries.
 - Object files for non-MSVC compiles are also placed in separate directories, making is faster to switch between debug and release compiles and it does not touch the directory with the source files.
 - Functionality to make a bundle of all needed files for for example a nightly or distribution of a binary with all needed GRFs and language files.

Note: as this merge moves almost all files, it is recommended to make a backup of your working copy before updating your working copy.
2007-01-02 19:19:48 +00:00

62 lines
1.7 KiB
C

/* $Id$ */
#ifndef DATE_H
#define DATE_H
#include "openttd.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 */