/**
 * Constants<p>
 *
 * These constants are used throughout the SunClock package.
 *
 * Copyright &copy; 1996-1998 Martin Minow. All Rights Reserved.<p>
 *
 * Permission to use, copy, modify, and redistribute this software and its
 * documentation for personal, non-commercial use is hereby granted provided that
 * this copyright notice and appropriate documentation appears in all copies. This
 * software may not be distributed for fee or as part of commercial, "shareware,"
 * and/or not-for-profit endevors including, but not limited to, CD-ROM collections,
 * online databases, and subscription services without specific license.<p>
 *
 * @author <a href="mailto:minow@merrymeet.com">Martin Minow</a>
 * @version 1.0
 * Set tabs every 4 characters.
 */
// package Classes;

import java.awt.*;

/**
 * Constants used throughout the SunClock applet. To use these values, a
 * class should implement the Constants class.
 */
public interface Constants {
	/**
	 * These bit-set values are passed from SunClockData to notification
	 * clients to indicate changes in the underlying data.
	 */
	public static final int		LOCATION_CHANGED		= 0x0001;
	public static final int		TIME_CHANGED			= 0x0002;
	public static final int		SUN_UPDATE_NEEDED		= 0x0004;
	public static final int		MOON_UPDATE_NEEDED		= 0x0008;
	public static final int		DISPLAY_FONT_CHANGED	= 0x0010;
	public static final int		WORLD_MAP_SIZE_CHANGED	= 0x0020;
	/**
	 * All observers watch for STOP_NOW and kill all asynchronous
	 * processes (including image loading) when it is received.
	 */
	public static final int		STOP_NOW			= 0x10;

	/**
	 * The sunrise and moonrise algorithms return values in a double[] vector
	 * where result[RISE] is the time of sun (moon) rise and result[SET]
	 * is the value of sun (moon) set. Sun.riseSetLST() also returns
	 * result[ASIMUTH_RISE] and result[ASIMUTH_SET].
	 */
	public static final int		RISE			= 0;
	public static final int		SET				= 1;
	public static final int		ASIMUTH_RISE	= 2;
	public static final int		ASIMUTH_SET		= 3;
	/**
	 * ABOVE_HORIZON and BELOW_HORIZON are returned for sun and moon
	 * calculations where the astronomical object does not cross the
	 * horizon.
	 */
	public static final double	ABOVE_HORIZON	= Double.POSITIVE_INFINITY;
	public static final double	BELOW_HORIZON	= Double.NEGATIVE_INFINITY;
	/**
	 * RA and DEC are indexes into the result vector from several
	 * astronomical functions.
	 */
    public static final int		RA					= 0;
    public static final int		DEC					= 1;
    
    /**
     * Degrees -> Radians:  degree * DegRad
     * Radians -> Degrees:  radians / DegRad
     */
	public static final double DegRad				= (Math.PI / 180.0);

    /**
     * These values define the location of the horizon for an observer
     * at sea level.
     *	 -0Á50'	Sunrise/Sunset
     *	 -6Á	Civil Twilight (default twilight)
     *	-12Á	Nautical Twilight
     *	-18Á	Astronomical Twilight
     * Note that these values are related to the horizon (90Á from the
     * azimuth). If the observer is above or below the horizon, the
     * correct adopted true sunrise/sunset altitude in degrees is
     *	-(50/60) - 0.0353 * sqrt(height in meters);
  	 *
  	 * Several religions use the times of twilight, sunrise, and sunset,
  	 * and other times derived from these times such as midday, to determine
  	 * the times of religious observation and obligation. For example, the Jewish
  	 * Sabbath ends at the time when "three stars" are observable after sunset,
  	 * which was specified by the Talmud as when the sun is 9 degrees below
  	 * the horizon.
  	 *
  	 * This program does not presume to provide theologically-correct results
  	 * and it should be noted that the rules are extremely complex, especially
  	 * at high latitudes: i.e., "when does Sabbath end when the sun never sets?"
  	 * You should consult a religious advisor for guidance in interpreting the
  	 * results of this program.
  	 *
     * The following are relevant to Jewish religious observance, as described
     * in Andrew H. Shooman's sunrise_prg.c, 26 January 1992.
     *
     * Morning Alot HaShachar	-15Á (The earliest time to begin Shacharit)
     * Taalit v'Tfilin			-12Á40' (Morning only)
	 * Sof Z'man Kriat Sh'ma	Sunrise + 3 hours
	 * Midday					The midpoint between sunrise and sunset
	 * Mincha K'tana			Midday + 1/2 hour: the earliest time to begin Mincha.
	 * Sabbath/holiday end		-9Á (The end of Sabbath or holiday observation,
	 *							derived from Rav Yehuda's Tzeit ha-Kochavim from
	 *							Shabbat 24b, 35a
     *
     * The following are relevant to Moslim religious observance, as described in
     * "Astronomy of Islamic Times," by Mohammad Ilyas, 1988. ISBN 0-7201-1983-9:
     *	Sunset					-0Á50'	(Sunrise/Sunset).
     *	Isha					-18Á	(End of astronomical twilight)
     *	Fajr					-18Á	(Beginning of astronomical twilight)
     *	Sunrise					-0Á50'	(Sunrise/Sunset)
     *	Midday					(Declination - Right Ascension)
     *	Asr (Shafi)				90Á - arccotangent(1 + cotangent(An))
     *							where An = 90Á - Zn
     *							and Zn is the zenith angle at noon.
     *	Asr (Hanafi)			90Á - arccotangent(2 + cotangent(An))
     *
     * Sunrise is defined as the time when the apparent altitlude of the upper
     * limb of the Sun will be -50 arc minutes below the horizon. This takes
     * into account refraction and solar semi-diameter effects.
     *
     * Twilight is defined as -6 degrees (civil), -12 degrees
     * (nautical), and -18 degrees (astronomical).
     */
	public static final double	SUNRISE					= -(50.0 / 60.0);
	public static final double	CIVIL_TWILIGHT			= -6.0;
	public static final double	NAUTICAL_TWILIGHT		= -12.0;
	public static final double	ASTRONOMICAL_TWILIGHT	= -18.0;
	public static final double	TWILIGHT				= CIVIL_TWILIGHT;
	public static final double	JEWISH_SABBATH_END		= -9.0;
	public static final double	JEWISH_MORNING_ALOT	= -15.0;
	public static final double	JEWISH_TFILIN			= -(12 + 40.0 / 60.0);
};