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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /intl/icu/source/i18n/astro.cpp
parentInitial commit. (diff)
downloadfirefox-esr-upstream.tar.xz
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Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/************************************************************************
+ * Copyright (C) 1996-2012, International Business Machines Corporation
+ * and others. All Rights Reserved.
+ ************************************************************************
+ * 2003-nov-07 srl Port from Java
+ */
+
+#include "astro.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/calendar.h"
+#include <math.h>
+#include <float.h>
+#include "unicode/putil.h"
+#include "uhash.h"
+#include "umutex.h"
+#include "ucln_in.h"
+#include "putilimp.h"
+#include <stdio.h> // for toString()
+
+#if defined (PI)
+#undef PI
+#endif
+
+#ifdef U_DEBUG_ASTRO
+# include "uresimp.h" // for debugging
+
+static void debug_astro_loc(const char *f, int32_t l)
+{
+ fprintf(stderr, "%s:%d: ", f, l);
+}
+
+static void debug_astro_msg(const char *pat, ...)
+{
+ va_list ap;
+ va_start(ap, pat);
+ vfprintf(stderr, pat, ap);
+ fflush(stderr);
+}
+#include "unicode/datefmt.h"
+#include "unicode/ustring.h"
+static const char * debug_astro_date(UDate d) {
+ static char gStrBuf[1024];
+ static DateFormat *df = nullptr;
+ if(df == nullptr) {
+ df = DateFormat::createDateTimeInstance(DateFormat::MEDIUM, DateFormat::MEDIUM, Locale::getUS());
+ df->adoptTimeZone(TimeZone::getGMT()->clone());
+ }
+ UnicodeString str;
+ df->format(d,str);
+ u_austrncpy(gStrBuf,str.getTerminatedBuffer(),sizeof(gStrBuf)-1);
+ return gStrBuf;
+}
+
+// must use double parens, i.e.: U_DEBUG_ASTRO_MSG(("four is: %d",4));
+#define U_DEBUG_ASTRO_MSG(x) {debug_astro_loc(__FILE__,__LINE__);debug_astro_msg x;}
+#else
+#define U_DEBUG_ASTRO_MSG(x)
+#endif
+
+static inline UBool isINVALID(double d) {
+ return(uprv_isNaN(d));
+}
+
+static icu::UMutex ccLock;
+
+U_CDECL_BEGIN
+static UBool calendar_astro_cleanup() {
+ return true;
+}
+U_CDECL_END
+
+U_NAMESPACE_BEGIN
+
+/**
+ * The number of standard hours in one sidereal day.
+ * Approximately 24.93.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define SIDEREAL_DAY (23.93446960027)
+
+/**
+ * The number of sidereal hours in one mean solar day.
+ * Approximately 24.07.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define SOLAR_DAY (24.065709816)
+
+/**
+ * The average number of solar days from one new moon to the next. This is the time
+ * it takes for the moon to return the same ecliptic longitude as the sun.
+ * It is longer than the sidereal month because the sun's longitude increases
+ * during the year due to the revolution of the earth around the sun.
+ * Approximately 29.53.
+ *
+ * @see #SIDEREAL_MONTH
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+const double CalendarAstronomer::SYNODIC_MONTH = 29.530588853;
+
+/**
+ * The average number of days it takes
+ * for the moon to return to the same ecliptic longitude relative to the
+ * stellar background. This is referred to as the sidereal month.
+ * It is shorter than the synodic month due to
+ * the revolution of the earth around the sun.
+ * Approximately 27.32.
+ *
+ * @see #SYNODIC_MONTH
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define SIDEREAL_MONTH 27.32166
+
+/**
+ * The average number number of days between successive vernal equinoxes.
+ * Due to the precession of the earth's
+ * axis, this is not precisely the same as the sidereal year.
+ * Approximately 365.24
+ *
+ * @see #SIDEREAL_YEAR
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define TROPICAL_YEAR 365.242191
+
+/**
+ * The average number of days it takes
+ * for the sun to return to the same position against the fixed stellar
+ * background. This is the duration of one orbit of the earth about the sun
+ * as it would appear to an outside observer.
+ * Due to the precession of the earth's
+ * axis, this is not precisely the same as the tropical year.
+ * Approximately 365.25.
+ *
+ * @see #TROPICAL_YEAR
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define SIDEREAL_YEAR 365.25636
+
+//-------------------------------------------------------------------------
+// Time-related constants
+//-------------------------------------------------------------------------
+
+/**
+ * The number of milliseconds in one second.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define SECOND_MS U_MILLIS_PER_SECOND
+
+/**
+ * The number of milliseconds in one minute.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define MINUTE_MS U_MILLIS_PER_MINUTE
+
+/**
+ * The number of milliseconds in one hour.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define HOUR_MS U_MILLIS_PER_HOUR
+
+/**
+ * The number of milliseconds in one day.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define DAY_MS U_MILLIS_PER_DAY
+
+/**
+ * The start of the julian day numbering scheme used by astronomers, which
+ * is 1/1/4713 BC (Julian), 12:00 GMT. This is given as the number of milliseconds
+ * since 1/1/1970 AD (Gregorian), a negative number.
+ * Note that julian day numbers and
+ * the Julian calendar are <em>not</em> the same thing. Also note that
+ * julian days start at <em>noon</em>, not midnight.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+#define JULIAN_EPOCH_MS -210866760000000.0
+
+
+/**
+ * Milliseconds value for 0.0 January 2000 AD.
+ */
+#define EPOCH_2000_MS 946598400000.0
+
+//-------------------------------------------------------------------------
+// Assorted private data used for conversions
+//-------------------------------------------------------------------------
+
+// My own copies of these so compilers are more likely to optimize them away
+const double CalendarAstronomer::PI = 3.14159265358979323846;
+
+#define CalendarAstronomer_PI2 (CalendarAstronomer::PI*2.0)
+#define RAD_HOUR ( 12 / CalendarAstronomer::PI ) // radians -> hours
+#define DEG_RAD ( CalendarAstronomer::PI / 180 ) // degrees -> radians
+#define RAD_DEG ( 180 / CalendarAstronomer::PI ) // radians -> degrees
+
+/***
+ * Given 'value', add or subtract 'range' until 0 <= 'value' < range.
+ * The modulus operator.
+ */
+inline static double normalize(double value, double range) {
+ return value - range * ClockMath::floorDivide(value, range);
+}
+
+/**
+ * Normalize an angle so that it's in the range 0 - 2pi.
+ * For positive angles this is just (angle % 2pi), but the Java
+ * mod operator doesn't work that way for negative numbers....
+ */
+inline static double norm2PI(double angle) {
+ return normalize(angle, CalendarAstronomer::PI * 2.0);
+}
+
+/**
+ * Normalize an angle into the range -PI - PI
+ */
+inline static double normPI(double angle) {
+ return normalize(angle + CalendarAstronomer::PI, CalendarAstronomer::PI * 2.0) - CalendarAstronomer::PI;
+}
+
+//-------------------------------------------------------------------------
+// Constructors
+//-------------------------------------------------------------------------
+
+/**
+ * Construct a new <code>CalendarAstronomer</code> object that is initialized to
+ * the current date and time.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::CalendarAstronomer():
+ fTime(Calendar::getNow()), fLongitude(0.0), fLatitude(0.0), fGmtOffset(0.0), moonPosition(0,0), moonPositionSet(false) {
+ clearCache();
+}
+
+/**
+ * Construct a new <code>CalendarAstronomer</code> object that is initialized to
+ * the specified date and time.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::CalendarAstronomer(UDate d): fTime(d), fLongitude(0.0), fLatitude(0.0), fGmtOffset(0.0), moonPosition(0,0), moonPositionSet(false) {
+ clearCache();
+}
+
+/**
+ * Construct a new <code>CalendarAstronomer</code> object with the given
+ * latitude and longitude. The object's time is set to the current
+ * date and time.
+ * <p>
+ * @param longitude The desired longitude, in <em>degrees</em> east of
+ * the Greenwich meridian.
+ *
+ * @param latitude The desired latitude, in <em>degrees</em>. Positive
+ * values signify North, negative South.
+ *
+ * @see java.util.Date#getTime()
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::CalendarAstronomer(double longitude, double latitude) :
+ fTime(Calendar::getNow()), moonPosition(0,0), moonPositionSet(false) {
+ fLongitude = normPI(longitude * (double)DEG_RAD);
+ fLatitude = normPI(latitude * (double)DEG_RAD);
+ fGmtOffset = (double)(fLongitude * 24. * (double)HOUR_MS / (double)CalendarAstronomer_PI2);
+ clearCache();
+}
+
+CalendarAstronomer::~CalendarAstronomer()
+{
+}
+
+//-------------------------------------------------------------------------
+// Time and date getters and setters
+//-------------------------------------------------------------------------
+
+/**
+ * Set the current date and time of this <code>CalendarAstronomer</code> object. All
+ * astronomical calculations are performed based on this time setting.
+ *
+ * @param aTime the date and time, expressed as the number of milliseconds since
+ * 1/1/1970 0:00 GMT (Gregorian).
+ *
+ * @see #setDate
+ * @see #getTime
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+void CalendarAstronomer::setTime(UDate aTime) {
+ fTime = aTime;
+ U_DEBUG_ASTRO_MSG(("setTime(%.1lf, %sL)\n", aTime, debug_astro_date(aTime+fGmtOffset)));
+ clearCache();
+}
+
+/**
+ * Set the current date and time of this <code>CalendarAstronomer</code> object. All
+ * astronomical calculations are performed based on this time setting.
+ *
+ * @param jdn the desired time, expressed as a "julian day number",
+ * which is the number of elapsed days since
+ * 1/1/4713 BC (Julian), 12:00 GMT. Note that julian day
+ * numbers start at <em>noon</em>. To get the jdn for
+ * the corresponding midnight, subtract 0.5.
+ *
+ * @see #getJulianDay
+ * @see #JULIAN_EPOCH_MS
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+void CalendarAstronomer::setJulianDay(double jdn) {
+ fTime = (double)(jdn * DAY_MS) + JULIAN_EPOCH_MS;
+ clearCache();
+ julianDay = jdn;
+}
+
+/**
+ * Get the current time of this <code>CalendarAstronomer</code> object,
+ * represented as the number of milliseconds since
+ * 1/1/1970 AD 0:00 GMT (Gregorian).
+ *
+ * @see #setTime
+ * @see #getDate
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+UDate CalendarAstronomer::getTime() {
+ return fTime;
+}
+
+/**
+ * Get the current time of this <code>CalendarAstronomer</code> object,
+ * expressed as a "julian day number", which is the number of elapsed
+ * days since 1/1/4713 BC (Julian), 12:00 GMT.
+ *
+ * @see #setJulianDay
+ * @see #JULIAN_EPOCH_MS
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::getJulianDay() {
+ if (isINVALID(julianDay)) {
+ julianDay = (fTime - (double)JULIAN_EPOCH_MS) / (double)DAY_MS;
+ }
+ return julianDay;
+}
+
+/**
+ * Return this object's time expressed in julian centuries:
+ * the number of centuries after 1/1/1900 AD, 12:00 GMT
+ *
+ * @see #getJulianDay
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::getJulianCentury() {
+ if (isINVALID(julianCentury)) {
+ julianCentury = (getJulianDay() - 2415020.0) / 36525.0;
+ }
+ return julianCentury;
+}
+
+/**
+ * Returns the current Greenwich sidereal time, measured in hours
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::getGreenwichSidereal() {
+ if (isINVALID(siderealTime)) {
+ // See page 86 of "Practical Astronomy with your Calculator",
+ // by Peter Duffet-Smith, for details on the algorithm.
+
+ double UT = normalize(fTime/(double)HOUR_MS, 24.);
+
+ siderealTime = normalize(getSiderealOffset() + UT*1.002737909, 24.);
+ }
+ return siderealTime;
+}
+
+double CalendarAstronomer::getSiderealOffset() {
+ if (isINVALID(siderealT0)) {
+ double JD = uprv_floor(getJulianDay() - 0.5) + 0.5;
+ double S = JD - 2451545.0;
+ double T = S / 36525.0;
+ siderealT0 = normalize(6.697374558 + 2400.051336*T + 0.000025862*T*T, 24);
+ }
+ return siderealT0;
+}
+
+/**
+ * Returns the current local sidereal time, measured in hours
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::getLocalSidereal() {
+ return normalize(getGreenwichSidereal() + (fGmtOffset/(double)HOUR_MS), 24.);
+}
+
+/**
+ * Converts local sidereal time to Universal Time.
+ *
+ * @param lst The Local Sidereal Time, in hours since sidereal midnight
+ * on this object's current date.
+ *
+ * @return The corresponding Universal Time, in milliseconds since
+ * 1 Jan 1970, GMT.
+ */
+double CalendarAstronomer::lstToUT(double lst) {
+ // Convert to local mean time
+ double lt = normalize((lst - getSiderealOffset()) * 0.9972695663, 24);
+
+ // Then find local midnight on this day
+ double base = (DAY_MS * ClockMath::floorDivide(fTime + fGmtOffset,(double)DAY_MS)) - fGmtOffset;
+
+ //out(" lt =" + lt + " hours");
+ //out(" base=" + new Date(base));
+
+ return base + (long)(lt * HOUR_MS);
+}
+
+
+//-------------------------------------------------------------------------
+// Coordinate transformations, all based on the current time of this object
+//-------------------------------------------------------------------------
+
+/**
+ * Convert from ecliptic to equatorial coordinates.
+ *
+ * @param ecliptic A point in the sky in ecliptic coordinates.
+ * @return The corresponding point in equatorial coordinates.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, const CalendarAstronomer::Ecliptic& ecliptic)
+{
+ return eclipticToEquatorial(result, ecliptic.longitude, ecliptic.latitude);
+}
+
+/**
+ * Convert from ecliptic to equatorial coordinates.
+ *
+ * @param eclipLong The ecliptic longitude
+ * @param eclipLat The ecliptic latitude
+ *
+ * @return The corresponding point in equatorial coordinates.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, double eclipLong, double eclipLat)
+{
+ // See page 42 of "Practical Astronomy with your Calculator",
+ // by Peter Duffet-Smith, for details on the algorithm.
+
+ double obliq = eclipticObliquity();
+ double sinE = ::sin(obliq);
+ double cosE = cos(obliq);
+
+ double sinL = ::sin(eclipLong);
+ double cosL = cos(eclipLong);
+
+ double sinB = ::sin(eclipLat);
+ double cosB = cos(eclipLat);
+ double tanB = tan(eclipLat);
+
+ result.set(atan2(sinL*cosE - tanB*sinE, cosL),
+ asin(sinB*cosE + cosB*sinE*sinL) );
+ return result;
+}
+
+/**
+ * Convert from ecliptic longitude to equatorial coordinates.
+ *
+ * @param eclipLong The ecliptic longitude
+ *
+ * @return The corresponding point in equatorial coordinates.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, double eclipLong)
+{
+ return eclipticToEquatorial(result, eclipLong, 0); // TODO: optimize
+}
+
+/**
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::Horizon& CalendarAstronomer::eclipticToHorizon(CalendarAstronomer::Horizon& result, double eclipLong)
+{
+ Equatorial equatorial;
+ eclipticToEquatorial(equatorial, eclipLong);
+
+ double H = getLocalSidereal()*CalendarAstronomer::PI/12 - equatorial.ascension; // Hour-angle
+
+ double sinH = ::sin(H);
+ double cosH = cos(H);
+ double sinD = ::sin(equatorial.declination);
+ double cosD = cos(equatorial.declination);
+ double sinL = ::sin(fLatitude);
+ double cosL = cos(fLatitude);
+
+ double altitude = asin(sinD*sinL + cosD*cosL*cosH);
+ double azimuth = atan2(-cosD*cosL*sinH, sinD - sinL * ::sin(altitude));
+
+ result.set(azimuth, altitude);
+ return result;
+}
+
+
+//-------------------------------------------------------------------------
+// The Sun
+//-------------------------------------------------------------------------
+
+//
+// Parameters of the Sun's orbit as of the epoch Jan 0.0 1990
+// Angles are in radians (after multiplying by CalendarAstronomer::PI/180)
+//
+#define JD_EPOCH 2447891.5 // Julian day of epoch
+
+#define SUN_ETA_G (279.403303 * CalendarAstronomer::PI/180) // Ecliptic longitude at epoch
+#define SUN_OMEGA_G (282.768422 * CalendarAstronomer::PI/180) // Ecliptic longitude of perigee
+#define SUN_E 0.016713 // Eccentricity of orbit
+//double sunR0 1.495585e8 // Semi-major axis in KM
+//double sunTheta0 (0.533128 * CalendarAstronomer::PI/180) // Angular diameter at R0
+
+// The following three methods, which compute the sun parameters
+// given above for an arbitrary epoch (whatever time the object is
+// set to), make only a small difference as compared to using the
+// above constants. E.g., Sunset times might differ by ~12
+// seconds. Furthermore, the eta-g computation is befuddled by
+// Duffet-Smith's incorrect coefficients (p.86). I've corrected
+// the first-order coefficient but the others may be off too - no
+// way of knowing without consulting another source.
+
+// /**
+// * Return the sun's ecliptic longitude at perigee for the current time.
+// * See Duffett-Smith, p. 86.
+// * @return radians
+// */
+// private double getSunOmegaG() {
+// double T = getJulianCentury();
+// return (281.2208444 + (1.719175 + 0.000452778*T)*T) * DEG_RAD;
+// }
+
+// /**
+// * Return the sun's ecliptic longitude for the current time.
+// * See Duffett-Smith, p. 86.
+// * @return radians
+// */
+// private double getSunEtaG() {
+// double T = getJulianCentury();
+// //return (279.6966778 + (36000.76892 + 0.0003025*T)*T) * DEG_RAD;
+// //
+// // The above line is from Duffett-Smith, and yields manifestly wrong
+// // results. The below constant is derived empirically to match the
+// // constant he gives for the 1990 EPOCH.
+// //
+// return (279.6966778 + (-0.3262541582718024 + 0.0003025*T)*T) * DEG_RAD;
+// }
+
+// /**
+// * Return the sun's eccentricity of orbit for the current time.
+// * See Duffett-Smith, p. 86.
+// * @return double
+// */
+// private double getSunE() {
+// double T = getJulianCentury();
+// return 0.01675104 - (0.0000418 + 0.000000126*T)*T;
+// }
+
+/**
+ * Find the "true anomaly" (longitude) of an object from
+ * its mean anomaly and the eccentricity of its orbit. This uses
+ * an iterative solution to Kepler's equation.
+ *
+ * @param meanAnomaly The object's longitude calculated as if it were in
+ * a regular, circular orbit, measured in radians
+ * from the point of perigee.
+ *
+ * @param eccentricity The eccentricity of the orbit
+ *
+ * @return The true anomaly (longitude) measured in radians
+ */
+static double trueAnomaly(double meanAnomaly, double eccentricity)
+{
+ // First, solve Kepler's equation iteratively
+ // Duffett-Smith, p.90
+ double delta;
+ double E = meanAnomaly;
+ do {
+ delta = E - eccentricity * ::sin(E) - meanAnomaly;
+ E = E - delta / (1 - eccentricity * ::cos(E));
+ }
+ while (uprv_fabs(delta) > 1e-5); // epsilon = 1e-5 rad
+
+ return 2.0 * ::atan( ::tan(E/2) * ::sqrt( (1+eccentricity)
+ /(1-eccentricity) ) );
+}
+
+/**
+ * The longitude of the sun at the time specified by this object.
+ * The longitude is measured in radians along the ecliptic
+ * from the "first point of Aries," the point at which the ecliptic
+ * crosses the earth's equatorial plane at the vernal equinox.
+ * <p>
+ * Currently, this method uses an approximation of the two-body Kepler's
+ * equation for the earth and the sun. It does not take into account the
+ * perturbations caused by the other planets, the moon, etc.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::getSunLongitude()
+{
+ // See page 86 of "Practical Astronomy with your Calculator",
+ // by Peter Duffet-Smith, for details on the algorithm.
+
+ if (isINVALID(sunLongitude)) {
+ getSunLongitude(getJulianDay(), sunLongitude, meanAnomalySun);
+ }
+ return sunLongitude;
+}
+
+/**
+ * TODO Make this public when the entire class is package-private.
+ */
+/*public*/ void CalendarAstronomer::getSunLongitude(double jDay, double &longitude, double &meanAnomaly)
+{
+ // See page 86 of "Practical Astronomy with your Calculator",
+ // by Peter Duffet-Smith, for details on the algorithm.
+
+ double day = jDay - JD_EPOCH; // Days since epoch
+
+ // Find the angular distance the sun in a fictitious
+ // circular orbit has travelled since the epoch.
+ double epochAngle = norm2PI(CalendarAstronomer_PI2/TROPICAL_YEAR*day);
+
+ // The epoch wasn't at the sun's perigee; find the angular distance
+ // since perigee, which is called the "mean anomaly"
+ meanAnomaly = norm2PI(epochAngle + SUN_ETA_G - SUN_OMEGA_G);
+
+ // Now find the "true anomaly", e.g. the real solar longitude
+ // by solving Kepler's equation for an elliptical orbit
+ // NOTE: The 3rd ed. of the book lists omega_g and eta_g in different
+ // equations; omega_g is to be correct.
+ longitude = norm2PI(trueAnomaly(meanAnomaly, SUN_E) + SUN_OMEGA_G);
+}
+
+/**
+ * The position of the sun at this object's current date and time,
+ * in equatorial coordinates.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+CalendarAstronomer::Equatorial& CalendarAstronomer::getSunPosition(CalendarAstronomer::Equatorial& result) {
+ return eclipticToEquatorial(result, getSunLongitude(), 0);
+}
+
+
+/**
+ * Constant representing the vernal equinox.
+ * For use with {@link #getSunTime getSunTime}.
+ * Note: In this case, "vernal" refers to the northern hemisphere's seasons.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+/*double CalendarAstronomer::VERNAL_EQUINOX() {
+ return 0;
+}*/
+
+/**
+ * Constant representing the summer solstice.
+ * For use with {@link #getSunTime getSunTime}.
+ * Note: In this case, "summer" refers to the northern hemisphere's seasons.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::SUMMER_SOLSTICE() {
+ return (CalendarAstronomer::PI/2);
+}
+
+/**
+ * Constant representing the autumnal equinox.
+ * For use with {@link #getSunTime getSunTime}.
+ * Note: In this case, "autumn" refers to the northern hemisphere's seasons.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+/*double CalendarAstronomer::AUTUMN_EQUINOX() {
+ return (CalendarAstronomer::PI);
+}*/
+
+/**
+ * Constant representing the winter solstice.
+ * For use with {@link #getSunTime getSunTime}.
+ * Note: In this case, "winter" refers to the northern hemisphere's seasons.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::WINTER_SOLSTICE() {
+ return ((CalendarAstronomer::PI*3)/2);
+}
+
+CalendarAstronomer::AngleFunc::~AngleFunc() {}
+
+/**
+ * Find the next time at which the sun's ecliptic longitude will have
+ * the desired value.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+class SunTimeAngleFunc : public CalendarAstronomer::AngleFunc {
+public:
+ virtual ~SunTimeAngleFunc();
+ virtual double eval(CalendarAstronomer& a) override { return a.getSunLongitude(); }
+};
+
+SunTimeAngleFunc::~SunTimeAngleFunc() {}
+
+UDate CalendarAstronomer::getSunTime(double desired, UBool next)
+{
+ SunTimeAngleFunc func;
+ return timeOfAngle( func,
+ desired,
+ TROPICAL_YEAR,
+ MINUTE_MS,
+ next);
+}
+
+CalendarAstronomer::CoordFunc::~CoordFunc() {}
+
+class RiseSetCoordFunc : public CalendarAstronomer::CoordFunc {
+public:
+ virtual ~RiseSetCoordFunc();
+ virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer& a) override { a.getSunPosition(result); }
+};
+
+RiseSetCoordFunc::~RiseSetCoordFunc() {}
+
+UDate CalendarAstronomer::getSunRiseSet(UBool rise)
+{
+ UDate t0 = fTime;
+
+ // Make a rough guess: 6am or 6pm local time on the current day
+ double noon = ClockMath::floorDivide(fTime + fGmtOffset, (double)DAY_MS)*DAY_MS - fGmtOffset + (12*HOUR_MS);
+
+ U_DEBUG_ASTRO_MSG(("Noon=%.2lf, %sL, gmtoff %.2lf\n", noon, debug_astro_date(noon+fGmtOffset), fGmtOffset));
+ setTime(noon + ((rise ? -6 : 6) * HOUR_MS));
+ U_DEBUG_ASTRO_MSG(("added %.2lf ms as a guess,\n", ((rise ? -6. : 6.) * HOUR_MS)));
+
+ RiseSetCoordFunc func;
+ double t = riseOrSet(func,
+ rise,
+ .533 * DEG_RAD, // Angular Diameter
+ 34. /60.0 * DEG_RAD, // Refraction correction
+ MINUTE_MS / 12.); // Desired accuracy
+
+ setTime(t0);
+ return t;
+}
+
+// Commented out - currently unused. ICU 2.6, Alan
+// //-------------------------------------------------------------------------
+// // Alternate Sun Rise/Set
+// // See Duffett-Smith p.93
+// //-------------------------------------------------------------------------
+//
+// // This yields worse results (as compared to USNO data) than getSunRiseSet().
+// /**
+// * TODO Make this when the entire class is package-private.
+// */
+// /*public*/ long getSunRiseSet2(boolean rise) {
+// // 1. Calculate coordinates of the sun's center for midnight
+// double jd = uprv_floor(getJulianDay() - 0.5) + 0.5;
+// double[] sl = getSunLongitude(jd);// double lambda1 = sl[0];
+// Equatorial pos1 = eclipticToEquatorial(lambda1, 0);
+//
+// // 2. Add ... to lambda to get position 24 hours later
+// double lambda2 = lambda1 + 0.985647*DEG_RAD;
+// Equatorial pos2 = eclipticToEquatorial(lambda2, 0);
+//
+// // 3. Calculate LSTs of rising and setting for these two positions
+// double tanL = ::tan(fLatitude);
+// double H = ::acos(-tanL * ::tan(pos1.declination));
+// double lst1r = (CalendarAstronomer_PI2 + pos1.ascension - H) * 24 / CalendarAstronomer_PI2;
+// double lst1s = (pos1.ascension + H) * 24 / CalendarAstronomer_PI2;
+// H = ::acos(-tanL * ::tan(pos2.declination));
+// double lst2r = (CalendarAstronomer_PI2-H + pos2.ascension ) * 24 / CalendarAstronomer_PI2;
+// double lst2s = (H + pos2.ascension ) * 24 / CalendarAstronomer_PI2;
+// if (lst1r > 24) lst1r -= 24;
+// if (lst1s > 24) lst1s -= 24;
+// if (lst2r > 24) lst2r -= 24;
+// if (lst2s > 24) lst2s -= 24;
+//
+// // 4. Convert LSTs to GSTs. If GST1 > GST2, add 24 to GST2.
+// double gst1r = lstToGst(lst1r);
+// double gst1s = lstToGst(lst1s);
+// double gst2r = lstToGst(lst2r);
+// double gst2s = lstToGst(lst2s);
+// if (gst1r > gst2r) gst2r += 24;
+// if (gst1s > gst2s) gst2s += 24;
+//
+// // 5. Calculate GST at 0h UT of this date
+// double t00 = utToGst(0);
+//
+// // 6. Calculate GST at 0h on the observer's longitude
+// double offset = ::round(fLongitude*12/PI); // p.95 step 6; he _rounds_ to nearest 15 deg.
+// double t00p = t00 - offset*1.002737909;
+// if (t00p < 0) t00p += 24; // do NOT normalize
+//
+// // 7. Adjust
+// if (gst1r < t00p) {
+// gst1r += 24;
+// gst2r += 24;
+// }
+// if (gst1s < t00p) {
+// gst1s += 24;
+// gst2s += 24;
+// }
+//
+// // 8.
+// double gstr = (24.07*gst1r-t00*(gst2r-gst1r))/(24.07+gst1r-gst2r);
+// double gsts = (24.07*gst1s-t00*(gst2s-gst1s))/(24.07+gst1s-gst2s);
+//
+// // 9. Correct for parallax, refraction, and sun's diameter
+// double dec = (pos1.declination + pos2.declination) / 2;
+// double psi = ::acos(sin(fLatitude) / cos(dec));
+// double x = 0.830725 * DEG_RAD; // parallax+refraction+diameter
+// double y = ::asin(sin(x) / ::sin(psi)) * RAD_DEG;
+// double delta_t = 240 * y / cos(dec) / 3600; // hours
+//
+// // 10. Add correction to GSTs, subtract from GSTr
+// gstr -= delta_t;
+// gsts += delta_t;
+//
+// // 11. Convert GST to UT and then to local civil time
+// double ut = gstToUt(rise ? gstr : gsts);
+// //System.out.println((rise?"rise=":"set=") + ut + ", delta_t=" + delta_t);
+// long midnight = DAY_MS * (time / DAY_MS); // Find UT midnight on this day
+// return midnight + (long) (ut * 3600000);
+// }
+
+// Commented out - currently unused. ICU 2.6, Alan
+// /**
+// * Convert local sidereal time to Greenwich sidereal time.
+// * Section 15. Duffett-Smith p.21
+// * @param lst in hours (0..24)
+// * @return GST in hours (0..24)
+// */
+// double lstToGst(double lst) {
+// double delta = fLongitude * 24 / CalendarAstronomer_PI2;
+// return normalize(lst - delta, 24);
+// }
+
+// Commented out - currently unused. ICU 2.6, Alan
+// /**
+// * Convert UT to GST on this date.
+// * Section 12. Duffett-Smith p.17
+// * @param ut in hours
+// * @return GST in hours
+// */
+// double utToGst(double ut) {
+// return normalize(getT0() + ut*1.002737909, 24);
+// }
+
+// Commented out - currently unused. ICU 2.6, Alan
+// /**
+// * Convert GST to UT on this date.
+// * Section 13. Duffett-Smith p.18
+// * @param gst in hours
+// * @return UT in hours
+// */
+// double gstToUt(double gst) {
+// return normalize(gst - getT0(), 24) * 0.9972695663;
+// }
+
+// Commented out - currently unused. ICU 2.6, Alan
+// double getT0() {
+// // Common computation for UT <=> GST
+//
+// // Find JD for 0h UT
+// double jd = uprv_floor(getJulianDay() - 0.5) + 0.5;
+//
+// double s = jd - 2451545.0;
+// double t = s / 36525.0;
+// double t0 = 6.697374558 + (2400.051336 + 0.000025862*t)*t;
+// return t0;
+// }
+
+// Commented out - currently unused. ICU 2.6, Alan
+// //-------------------------------------------------------------------------
+// // Alternate Sun Rise/Set
+// // See sci.astro FAQ
+// // http://www.faqs.org/faqs/astronomy/faq/part3/section-5.html
+// //-------------------------------------------------------------------------
+//
+// // Note: This method appears to produce inferior accuracy as
+// // compared to getSunRiseSet().
+//
+// /**
+// * TODO Make this when the entire class is package-private.
+// */
+// /*public*/ long getSunRiseSet3(boolean rise) {
+//
+// // Compute day number for 0.0 Jan 2000 epoch
+// double d = (double)(time - EPOCH_2000_MS) / DAY_MS;
+//
+// // Now compute the Local Sidereal Time, LST:
+// //
+// double LST = 98.9818 + 0.985647352 * d + /*UT*15 + long*/
+// fLongitude*RAD_DEG;
+// //
+// // (east long. positive). Note that LST is here expressed in degrees,
+// // where 15 degrees corresponds to one hour. Since LST really is an angle,
+// // it's convenient to use one unit---degrees---throughout.
+//
+// // COMPUTING THE SUN'S POSITION
+// // ----------------------------
+// //
+// // To be able to compute the Sun's rise/set times, you need to be able to
+// // compute the Sun's position at any time. First compute the "day
+// // number" d as outlined above, for the desired moment. Next compute:
+// //
+// double oblecl = 23.4393 - 3.563E-7 * d;
+// //
+// double w = 282.9404 + 4.70935E-5 * d;
+// double M = 356.0470 + 0.9856002585 * d;
+// double e = 0.016709 - 1.151E-9 * d;
+// //
+// // This is the obliquity of the ecliptic, plus some of the elements of
+// // the Sun's apparent orbit (i.e., really the Earth's orbit): w =
+// // argument of perihelion, M = mean anomaly, e = eccentricity.
+// // Semi-major axis is here assumed to be exactly 1.0 (while not strictly
+// // true, this is still an accurate approximation). Next compute E, the
+// // eccentric anomaly:
+// //
+// double E = M + e*(180/PI) * ::sin(M*DEG_RAD) * ( 1.0 + e*cos(M*DEG_RAD) );
+// //
+// // where E and M are in degrees. This is it---no further iterations are
+// // needed because we know e has a sufficiently small value. Next compute
+// // the true anomaly, v, and the distance, r:
+// //
+// /* r * cos(v) = */ double A = cos(E*DEG_RAD) - e;
+// /* r * ::sin(v) = */ double B = ::sqrt(1 - e*e) * ::sin(E*DEG_RAD);
+// //
+// // and
+// //
+// // r = sqrt( A*A + B*B )
+// double v = ::atan2( B, A )*RAD_DEG;
+// //
+// // The Sun's true longitude, slon, can now be computed:
+// //
+// double slon = v + w;
+// //
+// // Since the Sun is always at the ecliptic (or at least very very close to
+// // it), we can use simplified formulae to convert slon (the Sun's ecliptic
+// // longitude) to sRA and sDec (the Sun's RA and Dec):
+// //
+// // ::sin(slon) * cos(oblecl)
+// // tan(sRA) = -------------------------
+// // cos(slon)
+// //
+// // ::sin(sDec) = ::sin(oblecl) * ::sin(slon)
+// //
+// // As was the case when computing az, the Azimuth, if possible use an
+// // atan2() function to compute sRA.
+//
+// double sRA = ::atan2(sin(slon*DEG_RAD) * cos(oblecl*DEG_RAD), cos(slon*DEG_RAD))*RAD_DEG;
+//
+// double sin_sDec = ::sin(oblecl*DEG_RAD) * ::sin(slon*DEG_RAD);
+// double sDec = ::asin(sin_sDec)*RAD_DEG;
+//
+// // COMPUTING RISE AND SET TIMES
+// // ----------------------------
+// //
+// // To compute when an object rises or sets, you must compute when it
+// // passes the meridian and the HA of rise/set. Then the rise time is
+// // the meridian time minus HA for rise/set, and the set time is the
+// // meridian time plus the HA for rise/set.
+// //
+// // To find the meridian time, compute the Local Sidereal Time at 0h local
+// // time (or 0h UT if you prefer to work in UT) as outlined above---name
+// // that quantity LST0. The Meridian Time, MT, will now be:
+// //
+// // MT = RA - LST0
+// double MT = normalize(sRA - LST, 360);
+// //
+// // where "RA" is the object's Right Ascension (in degrees!). If negative,
+// // add 360 deg to MT. If the object is the Sun, leave the time as it is,
+// // but if it's stellar, multiply MT by 365.2422/366.2422, to convert from
+// // sidereal to solar time. Now, compute HA for rise/set, name that
+// // quantity HA0:
+// //
+// // ::sin(h0) - ::sin(lat) * ::sin(Dec)
+// // cos(HA0) = ---------------------------------
+// // cos(lat) * cos(Dec)
+// //
+// // where h0 is the altitude selected to represent rise/set. For a purely
+// // mathematical horizon, set h0 = 0 and simplify to:
+// //
+// // cos(HA0) = - tan(lat) * tan(Dec)
+// //
+// // If you want to account for refraction on the atmosphere, set h0 = -35/60
+// // degrees (-35 arc minutes), and if you want to compute the rise/set times
+// // for the Sun's upper limb, set h0 = -50/60 (-50 arc minutes).
+// //
+// double h0 = -50/60 * DEG_RAD;
+//
+// double HA0 = ::acos(
+// (sin(h0) - ::sin(fLatitude) * sin_sDec) /
+// (cos(fLatitude) * cos(sDec*DEG_RAD)))*RAD_DEG;
+//
+// // When HA0 has been computed, leave it as it is for the Sun but multiply
+// // by 365.2422/366.2422 for stellar objects, to convert from sidereal to
+// // solar time. Finally compute:
+// //
+// // Rise time = MT - HA0
+// // Set time = MT + HA0
+// //
+// // convert the times from degrees to hours by dividing by 15.
+// //
+// // If you'd like to check that your calculations are accurate or just
+// // need a quick result, check the USNO's Sun or Moon Rise/Set Table,
+// // <URL:http://aa.usno.navy.mil/AA/data/docs/RS_OneYear.html>.
+//
+// double result = MT + (rise ? -HA0 : HA0); // in degrees
+//
+// // Find UT midnight on this day
+// long midnight = DAY_MS * (time / DAY_MS);
+//
+// return midnight + (long) (result * 3600000 / 15);
+// }
+
+//-------------------------------------------------------------------------
+// The Moon
+//-------------------------------------------------------------------------
+
+#define moonL0 (318.351648 * CalendarAstronomer::PI/180 ) // Mean long. at epoch
+#define moonP0 ( 36.340410 * CalendarAstronomer::PI/180 ) // Mean long. of perigee
+#define moonN0 ( 318.510107 * CalendarAstronomer::PI/180 ) // Mean long. of node
+#define moonI ( 5.145366 * CalendarAstronomer::PI/180 ) // Inclination of orbit
+#define moonE ( 0.054900 ) // Eccentricity of orbit
+
+// These aren't used right now
+#define moonA ( 3.84401e5 ) // semi-major axis (km)
+#define moonT0 ( 0.5181 * CalendarAstronomer::PI/180 ) // Angular size at distance A
+#define moonPi ( 0.9507 * CalendarAstronomer::PI/180 ) // Parallax at distance A
+
+/**
+ * The position of the moon at the time set on this
+ * object, in equatorial coordinates.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+const CalendarAstronomer::Equatorial& CalendarAstronomer::getMoonPosition()
+{
+ //
+ // See page 142 of "Practical Astronomy with your Calculator",
+ // by Peter Duffet-Smith, for details on the algorithm.
+ //
+ if (moonPositionSet == false) {
+ // Calculate the solar longitude. Has the side effect of
+ // filling in "meanAnomalySun" as well.
+ getSunLongitude();
+
+ //
+ // Find the # of days since the epoch of our orbital parameters.
+ // TODO: Convert the time of day portion into ephemeris time
+ //
+ double day = getJulianDay() - JD_EPOCH; // Days since epoch
+
+ // Calculate the mean longitude and anomaly of the moon, based on
+ // a circular orbit. Similar to the corresponding solar calculation.
+ double meanLongitude = norm2PI(13.1763966*PI/180*day + moonL0);
+ meanAnomalyMoon = norm2PI(meanLongitude - 0.1114041*PI/180 * day - moonP0);
+
+ //
+ // Calculate the following corrections:
+ // Evection: the sun's gravity affects the moon's eccentricity
+ // Annual Eqn: variation in the effect due to earth-sun distance
+ // A3: correction factor (for ???)
+ //
+ double evection = 1.2739*PI/180 * ::sin(2 * (meanLongitude - sunLongitude)
+ - meanAnomalyMoon);
+ double annual = 0.1858*PI/180 * ::sin(meanAnomalySun);
+ double a3 = 0.3700*PI/180 * ::sin(meanAnomalySun);
+
+ meanAnomalyMoon += evection - annual - a3;
+
+ //
+ // More correction factors:
+ // center equation of the center correction
+ // a4 yet another error correction (???)
+ //
+ // TODO: Skip the equation of the center correction and solve Kepler's eqn?
+ //
+ double center = 6.2886*PI/180 * ::sin(meanAnomalyMoon);
+ double a4 = 0.2140*PI/180 * ::sin(2 * meanAnomalyMoon);
+
+ // Now find the moon's corrected longitude
+ moonLongitude = meanLongitude + evection + center - annual + a4;
+
+ //
+ // And finally, find the variation, caused by the fact that the sun's
+ // gravitational pull on the moon varies depending on which side of
+ // the earth the moon is on
+ //
+ double variation = 0.6583*CalendarAstronomer::PI/180 * ::sin(2*(moonLongitude - sunLongitude));
+
+ moonLongitude += variation;
+
+ //
+ // What we've calculated so far is the moon's longitude in the plane
+ // of its own orbit. Now map to the ecliptic to get the latitude
+ // and longitude. First we need to find the longitude of the ascending
+ // node, the position on the ecliptic where it is crossed by the moon's
+ // orbit as it crosses from the southern to the northern hemisphere.
+ //
+ double nodeLongitude = norm2PI(moonN0 - 0.0529539*PI/180 * day);
+
+ nodeLongitude -= 0.16*PI/180 * ::sin(meanAnomalySun);
+
+ double y = ::sin(moonLongitude - nodeLongitude);
+ double x = cos(moonLongitude - nodeLongitude);
+
+ moonEclipLong = ::atan2(y*cos(moonI), x) + nodeLongitude;
+ double moonEclipLat = ::asin(y * ::sin(moonI));
+
+ eclipticToEquatorial(moonPosition, moonEclipLong, moonEclipLat);
+ moonPositionSet = true;
+ }
+ return moonPosition;
+}
+
+/**
+ * The "age" of the moon at the time specified in this object.
+ * This is really the angle between the
+ * current ecliptic longitudes of the sun and the moon,
+ * measured in radians.
+ *
+ * @see #getMoonPhase
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::getMoonAge() {
+ // See page 147 of "Practical Astronomy with your Calculator",
+ // by Peter Duffet-Smith, for details on the algorithm.
+ //
+ // Force the moon's position to be calculated. We're going to use
+ // some the intermediate results cached during that calculation.
+ //
+ getMoonPosition();
+
+ return norm2PI(moonEclipLong - sunLongitude);
+}
+
+/**
+ * Calculate the phase of the moon at the time set in this object.
+ * The returned phase is a <code>double</code> in the range
+ * <code>0 <= phase < 1</code>, interpreted as follows:
+ * <ul>
+ * <li>0.00: New moon
+ * <li>0.25: First quarter
+ * <li>0.50: Full moon
+ * <li>0.75: Last quarter
+ * </ul>
+ *
+ * @see #getMoonAge
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+double CalendarAstronomer::getMoonPhase() {
+ // See page 147 of "Practical Astronomy with your Calculator",
+ // by Peter Duffet-Smith, for details on the algorithm.
+ return 0.5 * (1 - cos(getMoonAge()));
+}
+
+/**
+ * Constant representing a new moon.
+ * For use with {@link #getMoonTime getMoonTime}
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+const CalendarAstronomer::MoonAge CalendarAstronomer::NEW_MOON() {
+ return CalendarAstronomer::MoonAge(0);
+}
+
+/**
+ * Constant representing the moon's first quarter.
+ * For use with {@link #getMoonTime getMoonTime}
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+/*const CalendarAstronomer::MoonAge CalendarAstronomer::FIRST_QUARTER() {
+ return CalendarAstronomer::MoonAge(CalendarAstronomer::PI/2);
+}*/
+
+/**
+ * Constant representing a full moon.
+ * For use with {@link #getMoonTime getMoonTime}
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+const CalendarAstronomer::MoonAge CalendarAstronomer::FULL_MOON() {
+ return CalendarAstronomer::MoonAge(CalendarAstronomer::PI);
+}
+/**
+ * Constant representing the moon's last quarter.
+ * For use with {@link #getMoonTime getMoonTime}
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+
+class MoonTimeAngleFunc : public CalendarAstronomer::AngleFunc {
+public:
+ virtual ~MoonTimeAngleFunc();
+ virtual double eval(CalendarAstronomer& a) override { return a.getMoonAge(); }
+};
+
+MoonTimeAngleFunc::~MoonTimeAngleFunc() {}
+
+/*const CalendarAstronomer::MoonAge CalendarAstronomer::LAST_QUARTER() {
+ return CalendarAstronomer::MoonAge((CalendarAstronomer::PI*3)/2);
+}*/
+
+/**
+ * Find the next or previous time at which the Moon's ecliptic
+ * longitude will have the desired value.
+ * <p>
+ * @param desired The desired longitude.
+ * @param next <tt>true</tt> if the next occurrence of the phase
+ * is desired, <tt>false</tt> for the previous occurrence.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+UDate CalendarAstronomer::getMoonTime(double desired, UBool next)
+{
+ MoonTimeAngleFunc func;
+ return timeOfAngle( func,
+ desired,
+ SYNODIC_MONTH,
+ MINUTE_MS,
+ next);
+}
+
+/**
+ * Find the next or previous time at which the moon will be in the
+ * desired phase.
+ * <p>
+ * @param desired The desired phase of the moon.
+ * @param next <tt>true</tt> if the next occurrence of the phase
+ * is desired, <tt>false</tt> for the previous occurrence.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+UDate CalendarAstronomer::getMoonTime(const CalendarAstronomer::MoonAge& desired, UBool next) {
+ return getMoonTime(desired.value, next);
+}
+
+class MoonRiseSetCoordFunc : public CalendarAstronomer::CoordFunc {
+public:
+ virtual ~MoonRiseSetCoordFunc();
+ virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer& a) override { result = a.getMoonPosition(); }
+};
+
+MoonRiseSetCoordFunc::~MoonRiseSetCoordFunc() {}
+
+/**
+ * Returns the time (GMT) of sunrise or sunset on the local date to which
+ * this calendar is currently set.
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+UDate CalendarAstronomer::getMoonRiseSet(UBool rise)
+{
+ MoonRiseSetCoordFunc func;
+ return riseOrSet(func,
+ rise,
+ .533 * DEG_RAD, // Angular Diameter
+ 34 /60.0 * DEG_RAD, // Refraction correction
+ MINUTE_MS); // Desired accuracy
+}
+
+//-------------------------------------------------------------------------
+// Interpolation methods for finding the time at which a given event occurs
+//-------------------------------------------------------------------------
+
+UDate CalendarAstronomer::timeOfAngle(AngleFunc& func, double desired,
+ double periodDays, double epsilon, UBool next)
+{
+ // Find the value of the function at the current time
+ double lastAngle = func.eval(*this);
+
+ // Find out how far we are from the desired angle
+ double deltaAngle = norm2PI(desired - lastAngle) ;
+
+ // Using the average period, estimate the next (or previous) time at
+ // which the desired angle occurs.
+ double deltaT = (deltaAngle + (next ? 0.0 : - CalendarAstronomer_PI2 )) * (periodDays*DAY_MS) / CalendarAstronomer_PI2;
+
+ double lastDeltaT = deltaT; // Liu
+ UDate startTime = fTime; // Liu
+
+ setTime(fTime + uprv_ceil(deltaT));
+
+ // Now iterate until we get the error below epsilon. Throughout
+ // this loop we use normPI to get values in the range -Pi to Pi,
+ // since we're using them as correction factors rather than absolute angles.
+ do {
+ // Evaluate the function at the time we've estimated
+ double angle = func.eval(*this);
+
+ // Find the # of milliseconds per radian at this point on the curve
+ double factor = uprv_fabs(deltaT / normPI(angle-lastAngle));
+
+ // Correct the time estimate based on how far off the angle is
+ deltaT = normPI(desired - angle) * factor;
+
+ // HACK:
+ //
+ // If abs(deltaT) begins to diverge we need to quit this loop.
+ // This only appears to happen when attempting to locate, for
+ // example, a new moon on the day of the new moon. E.g.:
+ //
+ // This result is correct:
+ // newMoon(7508(Mon Jul 23 00:00:00 CST 1990,false))=
+ // Sun Jul 22 10:57:41 CST 1990
+ //
+ // But attempting to make the same call a day earlier causes deltaT
+ // to diverge:
+ // CalendarAstronomer.timeOfAngle() diverging: 1.348508727575625E9 ->
+ // 1.3649828540224032E9
+ // newMoon(7507(Sun Jul 22 00:00:00 CST 1990,false))=
+ // Sun Jul 08 13:56:15 CST 1990
+ //
+ // As a temporary solution, we catch this specific condition and
+ // adjust our start time by one eighth period days (either forward
+ // or backward) and try again.
+ // Liu 11/9/00
+ if (uprv_fabs(deltaT) > uprv_fabs(lastDeltaT)) {
+ double delta = uprv_ceil (periodDays * DAY_MS / 8.0);
+ setTime(startTime + (next ? delta : -delta));
+ return timeOfAngle(func, desired, periodDays, epsilon, next);
+ }
+
+ lastDeltaT = deltaT;
+ lastAngle = angle;
+
+ setTime(fTime + uprv_ceil(deltaT));
+ }
+ while (uprv_fabs(deltaT) > epsilon);
+
+ return fTime;
+}
+
+UDate CalendarAstronomer::riseOrSet(CoordFunc& func, UBool rise,
+ double diameter, double refraction,
+ double epsilon)
+{
+ Equatorial pos;
+ double tanL = ::tan(fLatitude);
+ double deltaT = 0;
+ int32_t count = 0;
+
+ //
+ // Calculate the object's position at the current time, then use that
+ // position to calculate the time of rising or setting. The position
+ // will be different at that time, so iterate until the error is allowable.
+ //
+ U_DEBUG_ASTRO_MSG(("setup rise=%s, dia=%.3lf, ref=%.3lf, eps=%.3lf\n",
+ rise?"T":"F", diameter, refraction, epsilon));
+ do {
+ // See "Practical Astronomy With Your Calculator, section 33.
+ func.eval(pos, *this);
+ double angle = ::acos(-tanL * ::tan(pos.declination));
+ double lst = ((rise ? CalendarAstronomer_PI2-angle : angle) + pos.ascension ) * 24 / CalendarAstronomer_PI2;
+
+ // Convert from LST to Universal Time.
+ UDate newTime = lstToUT( lst );
+
+ deltaT = newTime - fTime;
+ setTime(newTime);
+ U_DEBUG_ASTRO_MSG(("%d] dT=%.3lf, angle=%.3lf, lst=%.3lf, A=%.3lf/D=%.3lf\n",
+ count, deltaT, angle, lst, pos.ascension, pos.declination));
+ }
+ while (++ count < 5 && uprv_fabs(deltaT) > epsilon);
+
+ // Calculate the correction due to refraction and the object's angular diameter
+ double cosD = ::cos(pos.declination);
+ double psi = ::acos(sin(fLatitude) / cosD);
+ double x = diameter / 2 + refraction;
+ double y = ::asin(sin(x) / ::sin(psi));
+ long delta = (long)((240 * y * RAD_DEG / cosD)*SECOND_MS);
+
+ return fTime + (rise ? -delta : delta);
+}
+ /**
+ * Return the obliquity of the ecliptic (the angle between the ecliptic
+ * and the earth's equator) at the current time. This varies due to
+ * the precession of the earth's axis.
+ *
+ * @return the obliquity of the ecliptic relative to the equator,
+ * measured in radians.
+ */
+double CalendarAstronomer::eclipticObliquity() {
+ if (isINVALID(eclipObliquity)) {
+ const double epoch = 2451545.0; // 2000 AD, January 1.5
+
+ double T = (getJulianDay() - epoch) / 36525;
+
+ eclipObliquity = 23.439292
+ - 46.815/3600 * T
+ - 0.0006/3600 * T*T
+ + 0.00181/3600 * T*T*T;
+
+ eclipObliquity *= DEG_RAD;
+ }
+ return eclipObliquity;
+}
+
+
+//-------------------------------------------------------------------------
+// Private data
+//-------------------------------------------------------------------------
+void CalendarAstronomer::clearCache() {
+ const double INVALID = uprv_getNaN();
+
+ julianDay = INVALID;
+ julianCentury = INVALID;
+ sunLongitude = INVALID;
+ meanAnomalySun = INVALID;
+ moonLongitude = INVALID;
+ moonEclipLong = INVALID;
+ meanAnomalyMoon = INVALID;
+ eclipObliquity = INVALID;
+ siderealTime = INVALID;
+ siderealT0 = INVALID;
+ moonPositionSet = false;
+}
+
+//private static void out(String s) {
+// System.out.println(s);
+//}
+
+//private static String deg(double rad) {
+// return Double.toString(rad * RAD_DEG);
+//}
+
+//private static String hours(long ms) {
+// return Double.toString((double)ms / HOUR_MS) + " hours";
+//}
+
+/**
+ * @internal
+ * @deprecated ICU 2.4. This class may be removed or modified.
+ */
+/*UDate CalendarAstronomer::local(UDate localMillis) {
+ // TODO - srl ?
+ TimeZone *tz = TimeZone::createDefault();
+ int32_t rawOffset;
+ int32_t dstOffset;
+ UErrorCode status = U_ZERO_ERROR;
+ tz->getOffset(localMillis, true, rawOffset, dstOffset, status);
+ delete tz;
+ return localMillis - rawOffset;
+}*/
+
+// Debugging functions
+UnicodeString CalendarAstronomer::Ecliptic::toString() const
+{
+#ifdef U_DEBUG_ASTRO
+ char tmp[800];
+ snprintf(tmp, sizeof(tmp), "[%.5f,%.5f]", longitude*RAD_DEG, latitude*RAD_DEG);
+ return UnicodeString(tmp, "");
+#else
+ return UnicodeString();
+#endif
+}
+
+UnicodeString CalendarAstronomer::Equatorial::toString() const
+{
+#ifdef U_DEBUG_ASTRO
+ char tmp[400];
+ snprintf(tmp, sizeof(tmp), "%f,%f",
+ (ascension*RAD_DEG), (declination*RAD_DEG));
+ return UnicodeString(tmp, "");
+#else
+ return UnicodeString();
+#endif
+}
+
+UnicodeString CalendarAstronomer::Horizon::toString() const
+{
+#ifdef U_DEBUG_ASTRO
+ char tmp[800];
+ snprintf(tmp, sizeof(tmp), "[%.5f,%.5f]", altitude*RAD_DEG, azimuth*RAD_DEG);
+ return UnicodeString(tmp, "");
+#else
+ return UnicodeString();
+#endif
+}
+
+
+// static private String radToHms(double angle) {
+// int hrs = (int) (angle*RAD_HOUR);
+// int min = (int)((angle*RAD_HOUR - hrs) * 60);
+// int sec = (int)((angle*RAD_HOUR - hrs - min/60.0) * 3600);
+
+// return Integer.toString(hrs) + "h" + min + "m" + sec + "s";
+// }
+
+// static private String radToDms(double angle) {
+// int deg = (int) (angle*RAD_DEG);
+// int min = (int)((angle*RAD_DEG - deg) * 60);
+// int sec = (int)((angle*RAD_DEG - deg - min/60.0) * 3600);
+
+// return Integer.toString(deg) + "\u00b0" + min + "'" + sec + "\"";
+// }
+
+// =============== Calendar Cache ================
+
+void CalendarCache::createCache(CalendarCache** cache, UErrorCode& status) {
+ ucln_i18n_registerCleanup(UCLN_I18N_ASTRO_CALENDAR, calendar_astro_cleanup);
+ if(cache == nullptr) {
+ status = U_MEMORY_ALLOCATION_ERROR;
+ } else {
+ *cache = new CalendarCache(32, status);
+ if(U_FAILURE(status)) {
+ delete *cache;
+ *cache = nullptr;
+ }
+ }
+}
+
+int32_t CalendarCache::get(CalendarCache** cache, int32_t key, UErrorCode &status) {
+ int32_t res;
+
+ if(U_FAILURE(status)) {
+ return 0;
+ }
+ umtx_lock(&ccLock);
+
+ if(*cache == nullptr) {
+ createCache(cache, status);
+ if(U_FAILURE(status)) {
+ umtx_unlock(&ccLock);
+ return 0;
+ }
+ }
+
+ res = uhash_igeti((*cache)->fTable, key);
+ U_DEBUG_ASTRO_MSG(("%p: GET: [%d] == %d\n", (*cache)->fTable, key, res));
+
+ umtx_unlock(&ccLock);
+ return res;
+}
+
+void CalendarCache::put(CalendarCache** cache, int32_t key, int32_t value, UErrorCode &status) {
+ if(U_FAILURE(status)) {
+ return;
+ }
+ umtx_lock(&ccLock);
+
+ if(*cache == nullptr) {
+ createCache(cache, status);
+ if(U_FAILURE(status)) {
+ umtx_unlock(&ccLock);
+ return;
+ }
+ }
+
+ uhash_iputi((*cache)->fTable, key, value, &status);
+ U_DEBUG_ASTRO_MSG(("%p: PUT: [%d] := %d\n", (*cache)->fTable, key, value));
+
+ umtx_unlock(&ccLock);
+}
+
+CalendarCache::CalendarCache(int32_t size, UErrorCode &status) {
+ fTable = uhash_openSize(uhash_hashLong, uhash_compareLong, nullptr, size, &status);
+ U_DEBUG_ASTRO_MSG(("%p: Opening.\n", fTable));
+}
+
+CalendarCache::~CalendarCache() {
+ if(fTable != nullptr) {
+ U_DEBUG_ASTRO_MSG(("%p: Closing.\n", fTable));
+ uhash_close(fTable);
+ }
+}
+
+U_NAMESPACE_END
+
+#endif // !UCONFIG_NO_FORMATTING