1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /*
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9 * This file incorporates work covered by the following license notice:
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11 * Licensed to the Apache Software Foundation (ASF) under one or more
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14 * ownership. The ASF licenses this file to you under the Apache
15 * License, Version 2.0 (the "License"); you may not use this file
16 * except in compliance with the License. You may obtain a copy of
17 * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 */
19
20 #include <sal/config.h>
21
22 #include <cmath>
23 #include <stdlib.h>
24
25 #include <calendar_hijri.hxx>
26 #include <tools/long.hxx>
27
28 using namespace ::com::sun::star::uno;
29 using namespace ::com::sun::star::lang;
30 using namespace ::com::sun::star::i18n;
31
32 #define GREGORIAN_CROSSOVER 2299161
33
34 namespace i18npool {
35
36 // not used
37 //static UErrorCode status; // status is shared in all calls to Calendar, it has to be reset for each call.
38
39 // radians per degree (pi/180)
40 const double Calendar_hijri::RadPerDeg = 0.01745329251994329577;
41
42 // Synodic Period (mean time between 2 successive new moon: 29d, 12 hr, 44min, 3sec
43 const double Calendar_hijri::SynPeriod = 29.53058868;
44 const double Calendar_hijri::SynMonth = 365.25/29.53058868; // Solar days in a year/SynPeriod
45
46 // Julian day on Jan 1, 1900
47 const double Calendar_hijri::jd1900 = 2415020.75933;
48
49 // Reference point: March 26, 2001 == 1422 Hijri == 1252 Synodial month from 1900
50 const sal_Int32 Calendar_hijri::SynRef = 1252;
51 const sal_Int32 Calendar_hijri::GregRef = 1422;
52
53 // Local time specific to Saudi Arabia
54 const double Calendar_hijri::SA_TimeZone = 3.0;
55
56 const double Calendar_hijri::EveningPeriod = 6.0;
57
58 const sal_Int32 Calendar_hijri::LeapYear[] = {
59 2, 5, 7, 10, 13, 16, 18, 21, 24, 26, 29
60 };
61
Calendar_hijri()62 Calendar_hijri::Calendar_hijri()
63 {
64 cCalendar = "com.sun.star.i18n.Calendar_hijri";
65 }
66
67 #define FIELDS ((1 << CalendarFieldIndex::ERA) | (1 << CalendarFieldIndex::YEAR) | (1 << CalendarFieldIndex::MONTH) | (1 << CalendarFieldIndex::DAY_OF_MONTH))
68
69 // map field value from hijri calendar to gregorian calendar
mapToGregorian()70 void Calendar_hijri::mapToGregorian()
71 {
72 if (!(fieldSet & FIELDS))
73 return;
74
75 sal_Int32 day = static_cast<sal_Int32>(fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH]);
76 sal_Int32 month = static_cast<sal_Int32>(fieldSetValue[CalendarFieldIndex::MONTH]) + 1;
77 sal_Int32 year = static_cast<sal_Int32>(fieldSetValue[CalendarFieldIndex::YEAR]);
78 if (fieldSetValue[CalendarFieldIndex::ERA] == 0)
79 year *= -1;
80
81 ToGregorian(&day, &month, &year);
82
83 fieldSetValue[CalendarFieldIndex::ERA] = year <= 0 ? 0 : 1;
84 fieldSetValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>(month - 1);
85 fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH] = static_cast<sal_Int16>(day);
86 fieldSetValue[CalendarFieldIndex::YEAR] = static_cast<sal_Int16>(abs(year));
87 fieldSet |= FIELDS;
88 }
89
90 // map field value from gregorian calendar to hijri calendar
mapFromGregorian()91 void Calendar_hijri::mapFromGregorian()
92 {
93 sal_Int32 month, day, year;
94
95 day = static_cast<sal_Int32>(fieldValue[CalendarFieldIndex::DAY_OF_MONTH]);
96 month = static_cast<sal_Int32>(fieldValue[CalendarFieldIndex::MONTH]) + 1;
97 year = static_cast<sal_Int32>(fieldValue[CalendarFieldIndex::YEAR]);
98 if (fieldValue[CalendarFieldIndex::ERA] == 0)
99 year *= -1;
100
101 // Get Hijri date
102 getHijri(&day, &month, &year);
103
104 fieldValue[CalendarFieldIndex::DAY_OF_MONTH] = static_cast<sal_Int16>(day);
105 fieldValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>(month - 1);
106 fieldValue[CalendarFieldIndex::YEAR] = static_cast<sal_Int16>(abs(year));
107 fieldValue[CalendarFieldIndex::ERA] = static_cast<sal_Int16>(year) < 1 ? 0 : 1;
108 }
109
110
111 // This function returns the Julian date/time of the Nth new moon since
112 // January 1900. The synodic month is passed as parameter.
113
114 // Adapted from "Astronomical Formulae for Calculators" by
115 // Jean Meeus, Third Edition, Willmann-Bell, 1985.
116
117 double
NewMoon(sal_Int32 n)118 Calendar_hijri::NewMoon(sal_Int32 n)
119 {
120 double jd, t, t2, t3, k, ma, sa, tf, xtra;
121 k = n;
122 t = k/1236.85; // Time in Julian centuries from 1900 January 0.5
123 t2 = t * t;
124 t3 = t2 * t;
125
126 // Mean time of phase
127 jd = jd1900
128 + SynPeriod * k
129 - 0.0001178 * t2
130 - 0.000000155 * t3
131 + 0.00033 * sin(RadPerDeg * (166.56 + 132.87 * t - 0.009173 * t2));
132
133 // Sun's mean anomaly in radian
134 sa = RadPerDeg * (359.2242
135 + 29.10535608 * k
136 - 0.0000333 * t2
137 - 0.00000347 * t3);
138
139 // Moon's mean anomaly
140 ma = RadPerDeg * (306.0253
141 + 385.81691806 * k
142 + 0.0107306 * t2
143 + 0.00001236 * t3);
144
145 // Moon's argument of latitude
146 tf = RadPerDeg * 2.0 * (21.2964
147 + 390.67050646 * k
148 - 0.0016528 * t2
149 - 0.00000239 * t3);
150
151 // should reduce to interval between 0 to 1.0 before calculating further
152 // Corrections for New Moon
153 xtra = (0.1734 - 0.000393 * t) * sin(sa)
154 + 0.0021 * sin(sa * 2)
155 - 0.4068 * sin(ma)
156 + 0.0161 * sin(2 * ma)
157 - 0.0004 * sin(3 * ma)
158 + 0.0104 * sin(tf)
159 - 0.0051 * sin(sa + ma)
160 - 0.0074 * sin(sa - ma)
161 + 0.0004 * sin(tf + sa)
162 - 0.0004 * sin(tf - sa)
163 - 0.0006 * sin(tf + ma)
164 + 0.0010 * sin(tf - ma)
165 + 0.0005 * sin(sa + 2 * ma);
166
167 // convert from Ephemeris Time (ET) to (approximate) Universal Time (UT)
168 jd += xtra - (0.41 + 1.2053 * t + 0.4992 * t2)/1440;
169
170 return jd;
171 }
172
173 // Get Hijri Date
174 void
getHijri(sal_Int32 * day,sal_Int32 * month,sal_Int32 * year)175 Calendar_hijri::getHijri(sal_Int32 *day, sal_Int32 *month, sal_Int32 *year)
176 {
177 double prevday;
178 // double dayfraction;
179 sal_Int32 syndiff;
180 sal_Int32 newsyn;
181 double newjd;
182 sal_Int32 synmonth;
183
184 // Get Julian Day from Gregorian
185 sal_Int32 const julday = getJulianDay(*day, *month, *year);
186
187 // obtain approx. of how many Synodic months since the beginning of the year 1900
188 synmonth = static_cast<sal_Int32>(0.5 + (julday - jd1900)/SynPeriod);
189
190 newsyn = synmonth;
191 prevday = julday - 0.5;
192
193 do {
194 newjd = NewMoon(newsyn);
195
196 // Decrement syntonic months
197 newsyn--;
198 } while (newjd > prevday);
199 newsyn++;
200
201 // difference from reference point
202 syndiff = newsyn - SynRef;
203
204 // Round up the day
205 *day = static_cast<sal_Int32>(julday - newjd + 0.5);
206 *month = (syndiff % 12) + 1;
207
208 // currently not supported
209 //dayOfYear = (sal_Int32)(month * SynPeriod + day);
210 *year = GregRef + static_cast<sal_Int32>(syndiff / 12);
211
212 // If month negative, consider it previous year
213 if (syndiff != 0 && *month <= 0) {
214 *month += 12;
215 (*year)--;
216 }
217
218 // If Before Hijri subtract 1
219 if (*year <= 0) (*year)--;
220 }
221
222 void
ToGregorian(sal_Int32 * day,sal_Int32 * month,sal_Int32 * year)223 Calendar_hijri::ToGregorian(sal_Int32 *day, sal_Int32 *month, sal_Int32 *year)
224 {
225 sal_Int32 nmonth;
226 // double dayfraction;
227 double jday;
228 // sal_Int32 dayint;
229
230 if ( *year < 0 ) (*year)++;
231
232 // Number of month from reference point
233 nmonth = *month + *year * 12 - (GregRef * 12 + 1);
234
235 // Add Synodic Reference point
236 nmonth += SynRef;
237
238 // Get Julian days add time too
239 jday = NewMoon(nmonth) + *day;
240
241 // Round-up
242 jday = std::trunc(jday + 0.5);
243
244 // Use algorithm from "Numerical Recipes in C"
245 getGregorianDay(static_cast<sal_Int32>(jday), day, month, year);
246
247 // Julian -> Gregorian only works for non-negative year
248 if ( *year <= 0 ) {
249 *day = -1;
250 *month = -1;
251 *year = -1;
252 }
253 }
254
255 /* this algorithm is taken from "Numerical Recipes in C", 2nd ed, pp 14-15. */
256 /* this algorithm only valid for non-negative gregorian year */
257 void
getGregorianDay(sal_Int32 lJulianDay,sal_Int32 * pnDay,sal_Int32 * pnMonth,sal_Int32 * pnYear)258 Calendar_hijri::getGregorianDay(sal_Int32 lJulianDay, sal_Int32 *pnDay, sal_Int32 *pnMonth, sal_Int32 *pnYear)
259 {
260 /* working variables */
261 tools::Long lFactorA, lFactorB, lFactorC, lFactorD, lFactorE;
262
263 /* test whether to adjust for the Gregorian calendar crossover */
264 if (lJulianDay >= GREGORIAN_CROSSOVER) {
265 /* calculate a small adjustment */
266 tools::Long lAdjust = static_cast<tools::Long>((static_cast<float>(lJulianDay - 1867216) - 0.25) / 36524.25);
267
268 lFactorA = lJulianDay + 1 + lAdjust - static_cast<tools::Long>(0.25 * lAdjust);
269
270 } else {
271 /* no adjustment needed */
272 lFactorA = lJulianDay;
273 }
274
275 lFactorB = lFactorA + 1524;
276 lFactorC = static_cast<tools::Long>(6680.0 + (static_cast<float>(lFactorB - 2439870) - 122.1) / 365.25);
277 lFactorD = static_cast<tools::Long>(365 * lFactorC + (0.25 * lFactorC));
278 lFactorE = static_cast<tools::Long>((lFactorB - lFactorD) / 30.6001);
279
280 /* now, pull out the day number */
281 *pnDay = lFactorB - lFactorD - static_cast<tools::Long>(30.6001 * lFactorE);
282
283 /* ...and the month, adjusting it if necessary */
284 *pnMonth = lFactorE - 1;
285 if (*pnMonth > 12)
286 (*pnMonth) -= 12;
287
288 /* ...and similarly for the year */
289 *pnYear = lFactorC - 4715;
290 if (*pnMonth > 2)
291 (*pnYear)--;
292
293 // Negative year adjustments
294 if (*pnYear <= 0)
295 (*pnYear)--;
296 }
297
298 sal_Int32
getJulianDay(sal_Int32 day,sal_Int32 month,sal_Int32 year)299 Calendar_hijri::getJulianDay(sal_Int32 day, sal_Int32 month, sal_Int32 year)
300 {
301 double jy, jm;
302
303 if( year == 0 ) {
304 return -1;
305 }
306
307 if( year == 1582 && month == 10 && day > 4 && day < 15 ) {
308 return -1;
309 }
310
311 if( month > 2 ) {
312 jy = year;
313 jm = month + 1;
314 } else {
315 jy = year - 1;
316 jm = month + 13;
317 }
318
319 sal_Int32 intgr = static_cast<sal_Int32>(static_cast<sal_Int32>(365.25 * jy) + static_cast<sal_Int32>(30.6001 * jm) + day + 1720995 );
320
321 //check for switch to Gregorian calendar
322 double const gregcal = 15 + 31 * ( 10 + 12 * 1582 );
323
324 if( day + 31 * (month + 12 * year) >= gregcal ) {
325 double ja;
326 ja = std::trunc(0.01 * jy);
327 intgr += static_cast<sal_Int32>(2 - ja + std::trunc(0.25 * ja));
328 }
329
330 return intgr;
331 }
332
333 }
334
335 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
336