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Diffstat (limited to 'i18npool/source/calendar/calendar_hijri.cxx')
| -rw-r--r-- | i18npool/source/calendar/calendar_hijri.cxx | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/i18npool/source/calendar/calendar_hijri.cxx b/i18npool/source/calendar/calendar_hijri.cxx new file mode 100644 index 000000000..ed64c80db --- /dev/null +++ b/i18npool/source/calendar/calendar_hijri.cxx @@ -0,0 +1,317 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#include <sal/config.h> +#include <i18nutil/calendar.hxx> +#include <cmath> +#include <stdlib.h> + +#include <calendar_hijri.hxx> +#include <tools/long.hxx> +#include <basegfx/numeric/ftools.hxx> + +using namespace ::com::sun::star::uno; +using namespace ::com::sun::star::lang; +using namespace ::com::sun::star::i18n; + +namespace i18npool { + +// Synodic Period (mean time between 2 successive new moon: 29d, 12 hr, 44min, 3sec +constexpr double SynPeriod = 29.53058868; + +// Julian day on Jan 1, 1900 +constexpr double jd1900 = 2415020.75933; + +// Reference point: March 26, 2001 == 1422 Hijri == 1252 Synodial month from 1900 +constexpr sal_Int32 SynRef = 1252; +constexpr sal_Int32 GregRef = 1422; + +Calendar_hijri::Calendar_hijri() +{ + cCalendar = "com.sun.star.i18n.Calendar_hijri"; +} + +#define FIELDS ((1 << CalendarFieldIndex::ERA) | (1 << CalendarFieldIndex::YEAR) | (1 << CalendarFieldIndex::MONTH) | (1 << CalendarFieldIndex::DAY_OF_MONTH)) + +// map field value from hijri calendar to gregorian calendar +void Calendar_hijri::mapToGregorian() +{ + if (!(fieldSet & FIELDS)) + return; + + sal_Int32 day = static_cast<sal_Int32>(fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH]); + sal_Int32 month = static_cast<sal_Int32>(fieldSetValue[CalendarFieldIndex::MONTH]) + 1; + sal_Int32 year = static_cast<sal_Int32>(fieldSetValue[CalendarFieldIndex::YEAR]); + if (fieldSetValue[CalendarFieldIndex::ERA] == 0) + year *= -1; + + ToGregorian(&day, &month, &year); + + fieldSetValue[CalendarFieldIndex::ERA] = year <= 0 ? 0 : 1; + fieldSetValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>(month - 1); + fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH] = static_cast<sal_Int16>(day); + fieldSetValue[CalendarFieldIndex::YEAR] = static_cast<sal_Int16>(abs(year)); + fieldSet |= FIELDS; +} + +// map field value from gregorian calendar to hijri calendar +void Calendar_hijri::mapFromGregorian() +{ + sal_Int32 month, day, year; + + day = static_cast<sal_Int32>(fieldValue[CalendarFieldIndex::DAY_OF_MONTH]); + month = static_cast<sal_Int32>(fieldValue[CalendarFieldIndex::MONTH]) + 1; + year = static_cast<sal_Int32>(fieldValue[CalendarFieldIndex::YEAR]); + if (fieldValue[CalendarFieldIndex::ERA] == 0) + year *= -1; + + // Get Hijri date + getHijri(&day, &month, &year); + + fieldValue[CalendarFieldIndex::DAY_OF_MONTH] = static_cast<sal_Int16>(day); + fieldValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>(month - 1); + fieldValue[CalendarFieldIndex::YEAR] = static_cast<sal_Int16>(abs(year)); + fieldValue[CalendarFieldIndex::ERA] = static_cast<sal_Int16>(year) < 1 ? 0 : 1; +} + + +// This function returns the Julian date/time of the Nth new moon since +// January 1900. The synodic month is passed as parameter. + +// Adapted from "Astronomical Formulae for Calculators" by +// Jean Meeus, Third Edition, Willmann-Bell, 1985. + +double +Calendar_hijri::NewMoon(sal_Int32 n) +{ + double jd, t, t2, t3, k, ma, sa, tf, xtra; + k = n; + t = k/1236.85; // Time in Julian centuries from 1900 January 0.5 + t2 = t * t; + t3 = t2 * t; + + // Mean time of phase + jd = jd1900 + + SynPeriod * k + - 0.0001178 * t2 + - 0.000000155 * t3 + + 0.00033 * sin(basegfx::deg2rad(166.56 + 132.87 * t - 0.009173 * t2)); + + // Sun's mean anomaly in radian + sa = basegfx::deg2rad(359.2242 + + 29.10535608 * k + - 0.0000333 * t2 + - 0.00000347 * t3); + + // Moon's mean anomaly + ma = basegfx::deg2rad(306.0253 + + 385.81691806 * k + + 0.0107306 * t2 + + 0.00001236 * t3); + + // Moon's argument of latitude + tf = 2.0 * basegfx::deg2rad(21.2964 + + 390.67050646 * k + - 0.0016528 * t2 + - 0.00000239 * t3); + + // should reduce to interval between 0 to 1.0 before calculating further + // Corrections for New Moon + xtra = (0.1734 - 0.000393 * t) * sin(sa) + + 0.0021 * sin(sa * 2) + - 0.4068 * sin(ma) + + 0.0161 * sin(2 * ma) + - 0.0004 * sin(3 * ma) + + 0.0104 * sin(tf) + - 0.0051 * sin(sa + ma) + - 0.0074 * sin(sa - ma) + + 0.0004 * sin(tf + sa) + - 0.0004 * sin(tf - sa) + - 0.0006 * sin(tf + ma) + + 0.0010 * sin(tf - ma) + + 0.0005 * sin(sa + 2 * ma); + + // convert from Ephemeris Time (ET) to (approximate) Universal Time (UT) + jd += xtra - (0.41 + 1.2053 * t + 0.4992 * t2)/1440; + + return jd; +} + +// Get Hijri Date +void +Calendar_hijri::getHijri(sal_Int32 *day, sal_Int32 *month, sal_Int32 *year) +{ + double prevday; + sal_Int32 syndiff; + sal_Int32 newsyn; + double newjd; + sal_Int32 synmonth; + + // Get Julian Day from Gregorian + sal_Int32 const julday = getJulianDay(*day, *month, *year); + + // obtain approx. of how many Synodic months since the beginning of the year 1900 + synmonth = static_cast<sal_Int32>(0.5 + (julday - jd1900)/SynPeriod); + + newsyn = synmonth; + prevday = julday - 0.5; + + do { + newjd = NewMoon(newsyn); + + // Decrement syntonic months + newsyn--; + } while (newjd > prevday); + newsyn++; + + // difference from reference point + syndiff = newsyn - SynRef; + + // Round up the day + *day = static_cast<sal_Int32>(julday - newjd + 0.5); + *month = (syndiff % 12) + 1; + + // currently not supported + //dayOfYear = (sal_Int32)(month * SynPeriod + day); + *year = GregRef + static_cast<sal_Int32>(syndiff / 12); + + // If month negative, consider it previous year + if (syndiff != 0 && *month <= 0) { + *month += 12; + (*year)--; + } + + // If Before Hijri subtract 1 + if (*year <= 0) (*year)--; +} + +void +Calendar_hijri::ToGregorian(sal_Int32 *day, sal_Int32 *month, sal_Int32 *year) +{ + sal_Int32 nmonth; + double jday; + + if ( *year < 0 ) (*year)++; + + // Number of month from reference point + nmonth = *month + *year * 12 - (GregRef * 12 + 1); + + // Add Synodic Reference point + nmonth += SynRef; + + // Get Julian days add time too + jday = NewMoon(nmonth) + *day; + + // Round-up + jday = std::trunc(jday + 0.5); + + // Use algorithm from "Numerical Recipes in C" + getGregorianDay(static_cast<sal_Int32>(jday), day, month, year); + + // Julian -> Gregorian only works for non-negative year + if ( *year <= 0 ) { + *day = -1; + *month = -1; + *year = -1; + } +} + +/* this algorithm is taken from "Numerical Recipes in C", 2nd ed, pp 14-15. */ +/* this algorithm only valid for non-negative gregorian year */ +void +Calendar_hijri::getGregorianDay(sal_Int32 lJulianDay, sal_Int32 *pnDay, sal_Int32 *pnMonth, sal_Int32 *pnYear) +{ + /* working variables */ + tools::Long lFactorA, lFactorB, lFactorC, lFactorD, lFactorE; + + constexpr sal_Int32 GREGORIAN_CROSSOVER = 2299161; + + /* test whether to adjust for the Gregorian calendar crossover */ + if (lJulianDay >= GREGORIAN_CROSSOVER) { + /* calculate a small adjustment */ + tools::Long lAdjust = static_cast<tools::Long>((static_cast<float>(lJulianDay - 1867216) - 0.25) / 36524.25); + + lFactorA = lJulianDay + 1 + lAdjust - static_cast<tools::Long>(0.25 * lAdjust); + + } else { + /* no adjustment needed */ + lFactorA = lJulianDay; + } + + lFactorB = lFactorA + 1524; + lFactorC = static_cast<tools::Long>(6680.0 + (static_cast<float>(lFactorB - 2439870) - 122.1) / 365.25); + lFactorD = static_cast<tools::Long>(365 * lFactorC + (0.25 * lFactorC)); + lFactorE = static_cast<tools::Long>((lFactorB - lFactorD) / i18nutil::monthDaysWithoutJanFeb); + + /* now, pull out the day number */ + *pnDay = lFactorB - lFactorD - static_cast<tools::Long>(i18nutil::monthDaysWithoutJanFeb * lFactorE); + + /* ...and the month, adjusting it if necessary */ + *pnMonth = lFactorE - 1; + if (*pnMonth > 12) + (*pnMonth) -= 12; + + /* ...and similarly for the year */ + *pnYear = lFactorC - 4715; + if (*pnMonth > 2) + (*pnYear)--; + + // Negative year adjustments + if (*pnYear <= 0) + (*pnYear)--; +} + +sal_Int32 +Calendar_hijri::getJulianDay(sal_Int32 day, sal_Int32 month, sal_Int32 year) +{ + double jy, jm; + + if( year == 0 ) { + return -1; + } + + if( year == 1582 && month == 10 && day > 4 && day < 15 ) { + return -1; + } + + if( month > 2 ) { + jy = year; + jm = month + 1; + } else { + jy = year - 1; + jm = month + 13; + } + + sal_Int32 intgr = static_cast<sal_Int32>(static_cast<sal_Int32>(365.25 * jy) + static_cast<sal_Int32>(i18nutil::monthDaysWithoutJanFeb * jm) + day + 1720995 ); + + //check for switch to Gregorian calendar + double const gregcal = 15 + 31 * ( 10 + 12 * 1582 ); + + if( day + 31 * (month + 12 * year) >= gregcal ) { + double ja; + ja = std::trunc(0.01 * jy); + intgr += static_cast<sal_Int32>(2 - ja + std::trunc(0.25 * ja)); + } + + return intgr; +} + +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |