Package org.shredzone.commons.suncalc

Enum SunTimes.Twilight

java.lang.Object

java.lang.Enum<SunTimes.Twilight>

org.shredzone.commons.suncalc.SunTimes.Twilight

All Implemented Interfaces:

Serializable, Comparable<SunTimes.Twilight>, java.lang.constant.Constable

Enclosing class:

SunTimes

public static enum SunTimes.Twilight
extends Enum<SunTimes.Twilight>

Enumeration of predefined twilights.

The twilight angles use a geocentric reference, by definition. However, VISUAL and VISUAL_LOWER are topocentric, and take the spectator's height and the atmospheric refraction into account.

See Also:

• Wikipedia: Twilight

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
ASTRONOMICAL	Astronomical twilight (-18°).
BLUE_HOUR	Blue hour (-4°).
CIVIL	Civil twilight (-6°).
GOLDEN_HOUR	Golden hour (6°).
HORIZON	The moment when the center of the sun crosses the horizon (0°).
NAUTICAL	Nautical twilight (-12°).
NIGHT_HOUR	End of Blue hour (-8°).
VISUAL	The moment when the visual upper edge of the sun crosses the horizon.
VISUAL_LOWER	The moment when the visual lower edge of the sun crosses the horizon.

Method Summary

Modifier and Type	Method	Description
double	getAngle()	Returns the sun's angle at the twilight position, in degrees.
double	getAngleRad()	Returns the sun's angle at the twilight position, in radians.
boolean	isTopocentric()	Returns true if this twilight position is topocentric.
static SunTimes.Twilight	valueOf(String name)	Returns the enum constant of this type with the specified name.
static SunTimes.Twilight[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

VISUAL

public static final SunTimes.Twilight VISUAL

The moment when the visual upper edge of the sun crosses the horizon. This is commonly referred to as "sunrise" and "sunset". Atmospheric refraction is taken into account.

This is the default.

VISUAL_LOWER

public static final SunTimes.Twilight VISUAL_LOWER

The moment when the visual lower edge of the sun crosses the horizon. This is the ending of the sunrise and the starting of the sunset. Atmospheric refraction is taken into account.

HORIZON

public static final SunTimes.Twilight HORIZON

The moment when the center of the sun crosses the horizon (0°).

CIVIL

public static final SunTimes.Twilight CIVIL

Civil twilight (-6°).

NAUTICAL

public static final SunTimes.Twilight NAUTICAL

Nautical twilight (-12°).

ASTRONOMICAL

public static final SunTimes.Twilight ASTRONOMICAL

Astronomical twilight (-18°).

GOLDEN_HOUR

public static final SunTimes.Twilight GOLDEN_HOUR

Golden hour (6°). The Golden hour is between GOLDEN_HOUR and BLUE_HOUR. The Magic hour is between GOLDEN_HOUR and CIVIL.

See Also:

• Wikipedia: Golden hour

BLUE_HOUR

public static final SunTimes.Twilight BLUE_HOUR

Blue hour (-4°). The Blue hour is between NIGHT_HOUR and BLUE_HOUR.

See Also:

• Wikipedia: Blue hour

NIGHT_HOUR

public static final SunTimes.Twilight NIGHT_HOUR

End of Blue hour (-8°).

"Night Hour" is not an official term, but just a name that is marking the beginning/end of the Blue hour.

Method Details

values

public static SunTimes.Twilight[] values()

Returns an array containing the constants of this enum type, in the order they are declared.

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static SunTimes.Twilight valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getAngle

public double getAngle()

Returns the sun's angle at the twilight position, in degrees.

getAngleRad

public double getAngleRad()

Returns the sun's angle at the twilight position, in radians.

isTopocentric

public boolean isTopocentric()

Returns true if this twilight position is topocentric. Then the parallax and the atmospheric refraction is taken into account.