com.revolsys.jts.geomgraph

Class Quadrant

java.lang.Object

com.revolsys.jts.geomgraph.Quadrant

public class Quadrant
extends Object

Utility functions for working with quadrants, which are numbered as follows:

 1 | 0
 --+--
 2 | 3
 

Version:

1.7

Field Summary

Fields

Modifier and Type	Field and Description
static int	NE
static int	NW
static int	SE
static int	SW

Constructor Summary

Constructors

Constructor and Description
Quadrant()

Method Summary

Methods

Modifier and Type	Method and Description
static int	commonHalfPlane(int quad1, int quad2) Returns the right-hand quadrant of the halfplane defined by the two quadrants, or -1 if the quadrants are opposite, or the quadrant if they are identical.
static boolean	isInHalfPlane(int quad, int halfPlane) Returns whether the given quadrant lies within the given halfplane (specified by its right-hand quadrant).
static boolean	isNorthern(int quad) Returns true if the given quadrant is 0 or 1.
static boolean	isOpposite(int quad1, int quad2) Returns true if the quadrants are 1 and 3, or 2 and 4
static int	quadrant(double dx, double dy) Returns the quadrant of a directed line segment (specified as x and y displacements, which cannot both be 0).
static int	quadrant(Point p0, Point p1) Returns the quadrant of a directed line segment from p0 to p1.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NE

public static final int NE

See Also:

Constant Field Values

NW

public static final int NW

See Also:

Constant Field Values

SW

public static final int SW

See Also:

Constant Field Values

SE

public static final int SE

See Also:

Constant Field Values

Constructor Detail

Quadrant

public Quadrant()

Method Detail

commonHalfPlane

public static int commonHalfPlane(int quad1,
                  int quad2)

Returns the right-hand quadrant of the halfplane defined by the two quadrants, or -1 if the quadrants are opposite, or the quadrant if they are identical.

isInHalfPlane

public static boolean isInHalfPlane(int quad,
                    int halfPlane)

Returns whether the given quadrant lies within the given halfplane (specified by its right-hand quadrant).

isNorthern

public static boolean isNorthern(int quad)

Returns true if the given quadrant is 0 or 1.

isOpposite

public static boolean isOpposite(int quad1,
                 int quad2)

Returns true if the quadrants are 1 and 3, or 2 and 4

quadrant

public static int quadrant(double dx,
           double dy)

Returns the quadrant of a directed line segment (specified as x and y displacements, which cannot both be 0).

Throws:

IllegalArgumentException - if the displacements are both 0

quadrant

public static int quadrant(Point p0,
           Point p1)

Returns the quadrant of a directed line segment from p0 to p1.

Throws:

IllegalArgumentException - if the points are equal