com.vividsolutions.jts.geom

Class Envelope

java.lang.Object

com.vividsolutions.jts.geom.Envelope

All Implemented Interfaces:

Serializable, Comparable

public class Envelope
extends Object
implements Comparable, Serializable

Defines a rectangular region of the 2D coordinate plane. It is often used to represent the bounding box of a Geometry, e.g. the minimum and maximum x and y values of the Coordinates.

Envelopes support infinite or half-infinite regions, by using the values of Double.POSITIVE_INFINITY and Double.NEGATIVE_INFINITY. Envelope objects may have a null value.

When Envelope objects are created or initialized, the supplies extent values are automatically sorted into the correct order.

Version:

1.7

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Envelope() Creates a null Envelope.
Envelope(Coordinate p) Creates an Envelope for a region defined by a single Coordinate.
Envelope(Coordinate p1, Coordinate p2) Creates an Envelope for a region defined by two Coordinates.
Envelope(double x1, double x2, double y1, double y2) Creates an Envelope for a region defined by maximum and minimum values.
Envelope(Envelope env) Create an Envelope from an existing Envelope.

Method Summary

Methods

Modifier and Type	Method and Description
Coordinate	centre() Computes the coordinate of the centre of this envelope (as long as it is non-null
int	compareTo(Object o) Compares two envelopes using lexicographic ordering.
boolean	contains(Coordinate p) Tests if the given point lies in or on the envelope.
boolean	contains(double x, double y) Tests if the given point lies in or on the envelope.
boolean	contains(Envelope other) Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).
boolean	covers(Coordinate p) Tests if the given point lies in or on the envelope.
boolean	covers(double x, double y) Tests if the given point lies in or on the envelope.
boolean	covers(Envelope other) Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).
double	distance(Envelope env) Computes the distance between this and another Envelope.
boolean	equals(Object other)
void	expandBy(double distance) Expands this envelope by a given distance in all directions.
void	expandBy(double deltaX, double deltaY) Expands this envelope by a given distance in all directions.
void	expandToInclude(Coordinate p) Enlarges this Envelope so that it contains the given Coordinate.
void	expandToInclude(double x, double y) Enlarges this Envelope so that it contains the given point.
void	expandToInclude(Envelope other) Enlarges this Envelope so that it contains the other Envelope.
double	getArea() Gets the area of this envelope.
double	getHeight() Returns the difference between the maximum and minimum y values.
double	getMaxX() Returns the Envelopes maximum x-value.
double	getMaxY() Returns the Envelopes maximum y-value.
double	getMinX() Returns the Envelopes minimum x-value.
double	getMinY() Returns the Envelopes minimum y-value.
double	getWidth() Returns the difference between the maximum and minimum x values.
int	hashCode()
void	init() Initialize to a null Envelope.
void	init(Coordinate p) Initialize an Envelope to a region defined by a single Coordinate.
void	init(Coordinate p1, Coordinate p2) Initialize an Envelope to a region defined by two Coordinates.
void	init(double x1, double x2, double y1, double y2) Initialize an Envelope for a region defined by maximum and minimum values.
void	init(Envelope env) Initialize an Envelope from an existing Envelope.
Envelope	intersection(Envelope env) Computes the intersection of two Envelopes.
boolean	intersects(Coordinate p) Check if the point p overlaps (lies inside) the region of this Envelope.
static boolean	intersects(Coordinate p1, Coordinate p2, Coordinate q) Test the point q to see whether it intersects the Envelope defined by p1-p2
static boolean	intersects(Coordinate p1, Coordinate p2, Coordinate q1, Coordinate q2) Tests whether the envelope defined by p1-p2 and the envelope defined by q1-q2 intersect.
boolean	intersects(double x, double y) Check if the point (x, y) overlaps (lies inside) the region of this Envelope.
boolean	intersects(Envelope other) Check if the region defined by other overlaps (intersects) the region of this Envelope.
boolean	isNull() Returns true if this Envelope is a "null" envelope.
double	maxExtent() Gets the maximum extent of this envelope across both dimensions.
double	minExtent() Gets the minimum extent of this envelope across both dimensions.
boolean	overlaps(Coordinate p) Deprecated. Use #intersects instead.
boolean	overlaps(double x, double y) Deprecated. Use #intersects instead.
boolean	overlaps(Envelope other) Deprecated. Use #intersects instead. In the future, #overlaps may be changed to be a true overlap check; that is, whether the intersection is two-dimensional.
void	setToNull() Makes this Envelope a "null" envelope, that is, the envelope of the empty geometry.
String	toString()
void	translate(double transX, double transY) Translates this envelope by given amounts in the X and Y direction.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Envelope

public Envelope()

Creates a null Envelope.

Envelope

public Envelope(double x1,
        double x2,
        double y1,
        double y2)

Creates an Envelope for a region defined by maximum and minimum values.

Parameters:

x1 - the first x-value

x2 - the second x-value

y1 - the first y-value

y2 - the second y-value

Envelope

public Envelope(Coordinate p1,
        Coordinate p2)

Creates an Envelope for a region defined by two Coordinates.

Parameters:

p1 - the first Coordinate

p2 - the second Coordinate

Envelope

public Envelope(Coordinate p)

Creates an Envelope for a region defined by a single Coordinate.

Parameters:

p - the Coordinate

Envelope

public Envelope(Envelope env)

Create an Envelope from an existing Envelope.

Parameters:

env - the Envelope to initialize from

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class Object

intersects

public static boolean intersects(Coordinate p1,
                 Coordinate p2,
                 Coordinate q)

Test the point q to see whether it intersects the Envelope defined by p1-p2

Parameters:

p1 - one extremal point of the envelope

p2 - another extremal point of the envelope

q - the point to test for intersection

Returns:

true if q intersects the envelope p1-p2

intersects

public static boolean intersects(Coordinate p1,
                 Coordinate p2,
                 Coordinate q1,
                 Coordinate q2)

Tests whether the envelope defined by p1-p2 and the envelope defined by q1-q2 intersect.

Parameters:

p1 - one extremal point of the envelope P

p2 - another extremal point of the envelope P

q1 - one extremal point of the envelope Q

q2 - another extremal point of the envelope Q

Returns:

true if Q intersects P

init

public void init()

Initialize to a null Envelope.

init

public void init(double x1,
        double x2,
        double y1,
        double y2)

Initialize an Envelope for a region defined by maximum and minimum values.

Parameters:

x1 - the first x-value

x2 - the second x-value

y1 - the first y-value

y2 - the second y-value

init

public void init(Coordinate p1,
        Coordinate p2)

Initialize an Envelope to a region defined by two Coordinates.

Parameters:

p1 - the first Coordinate

p2 - the second Coordinate

init

public void init(Coordinate p)

Initialize an Envelope to a region defined by a single Coordinate.

Parameters:

p - the coordinate

init

public void init(Envelope env)

Initialize an Envelope from an existing Envelope.

Parameters:

env - the Envelope to initialize from

setToNull

public void setToNull()

Makes this Envelope a "null" envelope, that is, the envelope of the empty geometry.

isNull

public boolean isNull()

Returns true if this Envelope is a "null" envelope.

Returns:

true if this Envelope is uninitialized or is the envelope of the empty geometry.

getWidth

public double getWidth()

Returns the difference between the maximum and minimum x values.

Returns:

max x - min x, or 0 if this is a null Envelope

getHeight

public double getHeight()

Returns the difference between the maximum and minimum y values.

Returns:

max y - min y, or 0 if this is a null Envelope

getMinX

public double getMinX()

Returns the Envelopes minimum x-value. min x > max x indicates that this is a null Envelope.

Returns:

the minimum x-coordinate

getMaxX

public double getMaxX()

Returns the Envelopes maximum x-value. min x > max x indicates that this is a null Envelope.

Returns:

the maximum x-coordinate

getMinY

public double getMinY()

Returns the Envelopes minimum y-value. min y > max y indicates that this is a null Envelope.

Returns:

the minimum y-coordinate

getMaxY

public double getMaxY()

Returns the Envelopes maximum y-value. min y > max y indicates that this is a null Envelope.

Returns:

the maximum y-coordinate

getArea

public double getArea()

Gets the area of this envelope.

Returns:

the area of the envelope

minExtent

public double minExtent()

Gets the minimum extent of this envelope across both dimensions.

Returns:

the minimum extent of this envelope

maxExtent

public double maxExtent()

Gets the maximum extent of this envelope across both dimensions.

Returns:

the maximum extent of this envelope

expandToInclude

public void expandToInclude(Coordinate p)

Enlarges this Envelope so that it contains the given Coordinate. Has no effect if the point is already on or within the envelope.

Parameters:

p - the Coordinate to expand to include

expandBy

public void expandBy(double distance)

Expands this envelope by a given distance in all directions. Both positive and negative distances are supported.

Parameters:

distance - the distance to expand the envelope

expandBy

public void expandBy(double deltaX,
            double deltaY)

Expands this envelope by a given distance in all directions. Both positive and negative distances are supported.

Parameters:

deltaX - the distance to expand the envelope along the the X axis

deltaY - the distance to expand the envelope along the the Y axis

expandToInclude

public void expandToInclude(double x,
                   double y)

Enlarges this Envelope so that it contains the given point. Has no effect if the point is already on or within the envelope.

Parameters:

x - the value to lower the minimum x to or to raise the maximum x to

y - the value to lower the minimum y to or to raise the maximum y to

expandToInclude

public void expandToInclude(Envelope other)

Enlarges this Envelope so that it contains the other Envelope. Has no effect if other is wholly on or within the envelope.

Parameters:

other - the Envelope to expand to include

translate

public void translate(double transX,
             double transY)

Translates this envelope by given amounts in the X and Y direction.

Parameters:

transX - the amount to translate along the X axis

transY - the amount to translate along the Y axis

centre

public Coordinate centre()

Computes the coordinate of the centre of this envelope (as long as it is non-null

Returns:

the centre coordinate of this envelope null if the envelope is null

intersection

public Envelope intersection(Envelope env)

Computes the intersection of two Envelopes.

Parameters:

env - the envelope to intersect with

Returns:

a new Envelope representing the intersection of the envelopes (this will be the null envelope if either argument is null, or they do not intersect

intersects

public boolean intersects(Envelope other)

Check if the region defined by other overlaps (intersects) the region of this Envelope.

Parameters:

other - the Envelope which this Envelope is being checked for overlapping

Returns:

true if the Envelopes overlap

overlaps

public boolean overlaps(Envelope other)

Deprecated. Use #intersects instead. In the future, #overlaps may be changed to be a true overlap check; that is, whether the intersection is two-dimensional.

intersects

public boolean intersects(Coordinate p)

Check if the point p overlaps (lies inside) the region of this Envelope.

Parameters:

p - the Coordinate to be tested

Returns:

true if the point overlaps this Envelope

overlaps

public boolean overlaps(Coordinate p)

Deprecated. Use #intersects instead.

intersects

public boolean intersects(double x,
                 double y)

Check if the point (x, y) overlaps (lies inside) the region of this Envelope.

Parameters:

x - the x-ordinate of the point

y - the y-ordinate of the point

Returns:

true if the point overlaps this Envelope

overlaps

public boolean overlaps(double x,
               double y)

Deprecated. Use #intersects instead.

contains

public boolean contains(Envelope other)

Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).

Note that this is not the same definition as the SFS contains, which would exclude the envelope boundary.

Parameters:

other - the Envelope to check

Returns:

true if other is contained in this Envelope

See Also:

covers(Envelope)

contains

public boolean contains(Coordinate p)

Tests if the given point lies in or on the envelope.

Note that this is not the same definition as the SFS contains, which would exclude the envelope boundary.

Parameters:

p - the point which this Envelope is being checked for containing

Returns:

true if the point lies in the interior or on the boundary of this Envelope.

See Also:

covers(Coordinate)

contains

public boolean contains(double x,
               double y)

Tests if the given point lies in or on the envelope.

Note that this is not the same definition as the SFS contains, which would exclude the envelope boundary.

Parameters:

x - the x-coordinate of the point which this Envelope is being checked for containing

y - the y-coordinate of the point which this Envelope is being checked for containing

Returns:

true if (x, y) lies in the interior or on the boundary of this Envelope.

See Also:

covers(double, double)

covers

public boolean covers(double x,
             double y)

Tests if the given point lies in or on the envelope.

Parameters:

x - the x-coordinate of the point which this Envelope is being checked for containing

y - the y-coordinate of the point which this Envelope is being checked for containing

Returns:

true if (x, y) lies in the interior or on the boundary of this Envelope.

covers

public boolean covers(Coordinate p)

Tests if the given point lies in or on the envelope.

Parameters:

p - the point which this Envelope is being checked for containing

Returns:

true if the point lies in the interior or on the boundary of this Envelope.

covers

public boolean covers(Envelope other)

Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).

Parameters:

other - the Envelope to check

Returns:

true if this Envelope covers the other

distance

public double distance(Envelope env)

Computes the distance between this and another Envelope. The distance between overlapping Envelopes is 0. Otherwise, the distance is the Euclidean distance between the closest points.

equals

public boolean equals(Object other)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(Object o)

Compares two envelopes using lexicographic ordering. The ordering comparison is based on the usual numerical comparison between the sequence of ordinates. Null envelopes are less than all non-null envelopes.

Specified by:

compareTo in interface Comparable

Parameters:

o - an Envelope object