An Envelope defines a rectangulare region of the 2D coordinate plane. More...

#include <geos.h>

Public Types
typedef std::unique_ptr< Envelope >	Ptr

Public Member Functions
	Envelope ()
	Creates a null Envelope.

	Envelope (double x1, double x2, double y1, double y2)
	Creates an Envelope for a region defined by maximum and minimum values.

	Envelope (const CoordinateXY &p1, const CoordinateXY &p2)
	Creates an Envelope for a region defined by two Coordinates.

	Envelope (const CoordinateXY &p)
	Creates an Envelope for a region defined by a single Coordinate.

	Envelope (const std::string &str)
	Create an Envelope from an Envelope string representation produced by Envelope::toString()

bool	intersects (const CoordinateXY &a, const CoordinateXY &b) const
	Check if the extent defined by two extremal points intersects the extent of this Envelope.

void	init ()
	Initialize to a null Envelope.

void	init (double x1, double x2, double y1, double y2)
	Initialize an Envelope for a region defined by maximum and minimum values.

void	init (const CoordinateXY &p1, const CoordinateXY &p2)
	Initialize an Envelope to a region defined by two Coordinates.

void	init (const CoordinateXY &p)
	Initialize an Envelope to a region defined by a single Coordinate.

void	setToNull ()
	Makes this `Envelope` a "null" envelope, that is, the envelope of the empty geometry.

bool	isNull (void) const
	Returns `true` if this Envelope is a "null" envelope.

double	getWidth () const
	Returns the difference between the maximum and minimum x values.

double	getHeight () const
	Returns the difference between the maximum and minimum y values.

double	getArea () const
	Gets the area of this envelope.

bool	isFinite () const
	Returns true if this Envelope covers a finite region.

double	getMaxY () const
	Returns the Envelope maximum y-value. Null envelopes do not have maximum values.

double	getMaxX () const
	Returns the Envelope maximum x-value. Null envelopes do not have maximum values.

double	getMinY () const
	Returns the Envelope minimum y-value. Null envelopes do not have maximum values.

double	getMinX () const
	Returns the Envelope minimum x-value. Null envelopes do not have maximum values.

double	getDiameter () const

bool	centre (CoordinateXY &centre) const
	Computes the coordinate of the centre of this envelope (as long as it is non-null).

bool	intersection (const Envelope &env, Envelope &result) const
	Computes the intersection of two Envelopes.

void	translate (double transX, double transY)
	Translates this envelope by given amounts in the X and Y direction.

void	expandBy (double deltaX, double deltaY)
	Expands this envelope by a given distance in all directions. Both positive and negative distances are supported.

void	expandBy (double p_distance)
	Expands this envelope by a given distance in all directions.

void	expandToInclude (const CoordinateXY &p)
	Enlarges the boundary of the Envelope so that it contains p. Does nothing if p is already on or within the boundaries.

void	expandToInclude (double x, double y)
	Enlarges the boundary of the Envelope so that it contains (x,y).

void	expandToInclude (const Envelope *other)
	Enlarges the boundary of the Envelope so that it contains `other`.

void	expandToInclude (const Envelope &other)

bool	contains (const Envelope &other) const
	Tests if the Envelope `other` lies wholly inside this Envelope (inclusive of the boundary).

bool	contains (const Envelope *other) const

bool	contains (const CoordinateXY &p) const
	Returns `true` if the given point lies in or on the envelope.

bool	contains (double x, double y) const
	Returns `true` if the given point lies in or on the envelope.

bool	intersects (const CoordinateXY &other) const
	Check if the point p intersects (lies inside) the region of this Envelope.

bool	intersects (double x, double y) const
	Check if the point (x, y) intersects (lies inside) the region of this Envelope.

bool	intersects (const Envelope *other) const
	Check if the region defined by other Envelope intersects the region of this Envelope.

bool	intersects (const Envelope &other) const

bool	disjoint (const Envelope &other) const

bool	disjoint (const Envelope *other) const

bool	covers (double x, double y) const
	Tests if the given point lies in or on the envelope.

bool	covers (const CoordinateXY *p) const
	Tests if the given point lies in or on the envelope.

bool	covers (const Envelope &other) const
	Tests if the Envelope `other` lies wholly inside this Envelope (inclusive of the boundary).

bool	covers (const Envelope *other) const

bool	equals (const Envelope *other) const
	Returns `true` if the Envelope `other` spatially equals this Envelope.

bool	isfinite () const

std::string	toString () const
	Returns a `string` of the form `Env[minx:maxx,miny:maxy]`.

double	distance (const Envelope &env) const
	Computes the distance between this and another Envelope.

double	maxDistance (const Envelope &other) const
	Computes the maximum distance between points in this and another Envelope.

double	distanceSquared (const Envelope &env) const
	Computes the square of the distance between this and another Envelope.

std::size_t	hashCode () const

Static Public Member Functions
static bool	intersects (const CoordinateXY &p1, const CoordinateXY &p2, const CoordinateXY &q)
	Test the point `q` to see whether it intersects the Envelope defined by `p1-p2`.

static bool	intersects (const CoordinateXY &p1, const CoordinateXY &p2, const CoordinateXY &q1, const CoordinateXY &q2)
	Test the envelope defined by `p1-p2` for intersection with the envelope defined by `q1-q2`.

static double	distanceToCoordinate (const CoordinateXY &c, const CoordinateXY &p0, const CoordinateXY &p1)
	Computes the distance between one Coordinate and an Envelope defined by two other Coordinates. The order of the Coordinates used to define the envelope is not significant.

static double	distanceSquaredToCoordinate (const CoordinateXY &c, const CoordinateXY &p0, const CoordinateXY &p1)
	Computes the squared distance between one Coordinate and an Envelope defined by two other Coordinates. The order of the Coordinates used to define the envelope is not significant.

Friends
std::ostream &	operator<< (std::ostream &os, const Envelope &o)
	Output operator.

bool	operator== (const Envelope &a, const Envelope &b)
	Checks if two Envelopes are equal (2D only check)

bool	operator!= (const Envelope &a, const Envelope &b)

bool	operator< (const Envelope &a, const Envelope &b)

Detailed Description

An Envelope defines a rectangulare 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 allow null values, which are represented with NaN values for ordinates. Envelopes support infinite or half-infinite regions, by using the values of Double_POSITIVE_INFINITY and Double_NEGATIVE_INFINITY.

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

Constructor & Destructor Documentation

◆ Envelope() [1/3]

geos::geom::Envelope::Envelope	(	double	x1,
		double	x2,
		double	y1,
		double	y2
	)

inline

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() [2/3]

geos::geom::Envelope::Envelope	(	const CoordinateXY &	p1,
		const CoordinateXY &	p2
	)

inline

Creates an Envelope for a region defined by two Coordinates.

Parameters

p1	the first Coordinate
p2	the second Coordinate

◆ Envelope() [3/3]

geos::geom::Envelope::Envelope ( const CoordinateXY & p )

inlineexplicit

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

Parameters

p	the Coordinate

Member Function Documentation

◆ centre()

bool geos::geom::Envelope::centre ( CoordinateXY & centre ) const

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

Parameters

centre The coordinate to write results into

Returns: false if the center could not be found (null envelope).

◆ contains() [1/3]

bool geos::geom::Envelope::contains ( const CoordinateXY & p ) const

inline

Returns true 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.

◆ contains() [2/3]

bool geos::geom::Envelope::contains ( const Envelope & other ) const

inline

Tests if the Envelope other lies wholly 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() [3/3]

bool geos::geom::Envelope::contains	(	double	x,
		double	y
	)		const

inline

Returns true 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() [1/3]

bool geos::geom::Envelope::covers ( const CoordinateXY * p ) const

inline

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() [2/3]

bool geos::geom::Envelope::covers ( const Envelope & other ) const

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

Parameters

other the Envelope to check

Returns: true if this Envelope covers the other

◆ covers() [3/3]

bool geos::geom::Envelope::covers	(	double	x,
		double	y
	)		const

inline

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.

◆ disjoint()

bool geos::geom::Envelope::disjoint ( const Envelope & other ) const

inline

Tests if the region defined by other is disjoint from the region of this Envelope

Parameters

other the Envelope being checked for disjointedness

Returns: true if the Envelopes are disjoint

◆ distance()

double geos::geom::Envelope::distance ( const Envelope & env ) const

inline

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.

◆ distanceSquared()

double geos::geom::Envelope::distanceSquared ( const Envelope & env ) const

inline

Computes the square of 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.

Referenced by geos::operation::cluster::EnvelopeDistanceClusterFinder::shouldJoin().

◆ distanceSquaredToCoordinate()

static double geos::geom::Envelope::distanceSquaredToCoordinate	(	const CoordinateXY &	c,
		const CoordinateXY &	p0,
		const CoordinateXY &	p1
	)

inlinestatic

Computes the squared distance between one Coordinate and an Envelope defined by two other Coordinates. The order of the Coordinates used to define the envelope is not significant.

Parameters

c	the coordinate to from which distance should be found
p0	first coordinate defining an envelope
p1	second coordinate defining an envelope.

◆ distanceToCoordinate()

static double geos::geom::Envelope::distanceToCoordinate	(	const CoordinateXY &	c,
		const CoordinateXY &	p0,
		const CoordinateXY &	p1
	)

inlinestatic

Computes the distance between one Coordinate and an Envelope defined by two other Coordinates. The order of the Coordinates used to define the envelope is not significant.

Parameters

c	the coordinate to from which distance should be found
p0	first coordinate defining an envelope
p1	second coordinate defining an envelope.

◆ equals()

bool geos::geom::Envelope::equals ( const Envelope * other ) const

Returns true if the Envelope other spatially equals this Envelope.

Parameters

other the Envelope which this Envelope is being checked for equality

Returns: true if this and other Envelope objects are spatially equal

◆ expandBy() [1/2]

void geos::geom::Envelope::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 X axis
deltaY	the distance to expand the envelope along the Y axis

Referenced by geos::operation::cluster::DBSCANClusterFinder::queryEnvelope(), geos::operation::cluster::EnvelopeDistanceClusterFinder::queryEnvelope(), and geos::operation::cluster::GeometryDistanceClusterFinder::queryEnvelope().

◆ expandBy() [2/2]

void geos::geom::Envelope::expandBy ( double p_distance )

inline

Expands this envelope by a given distance in all directions.

Both positive and negative distances are supported.

Parameters

p_distance the distance to expand the envelope

◆ expandToInclude() [1/3]

void geos::geom::Envelope::expandToInclude ( const CoordinateXY & p )

inline

Enlarges the boundary of the Envelope so that it contains p. Does nothing if p is already on or within the boundaries.

Parameters

p	the Coordinate to include

◆ expandToInclude() [2/3]

void geos::geom::Envelope::expandToInclude ( const Envelope * other )

inline

Enlarges the boundary of the Envelope so that it contains other.

Does nothing if other is wholly on or within the boundaries.

Parameters

other the Envelope to merge with

◆ expandToInclude() [3/3]

void geos::geom::Envelope::expandToInclude	(	double	x,
		double	y
	)

inline

Enlarges the boundary of the Envelope so that it contains (x,y).

Does nothing if (x,y) is already on or within the boundaries.

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

◆ getArea()

double geos::geom::Envelope::getArea ( ) const

inline

Gets the area of this envelope.

Returns: the area of the envelope; 0.0 if the envelope is null

◆ getDiameter()

double geos::geom::Envelope::getDiameter ( ) const

inline

Gets the length of the diameter (diagonal) of the envelope.

Returns: the diameter length

◆ getHeight()

double geos::geom::Envelope::getHeight ( ) const

inline

Returns the difference between the maximum and minimum y values.

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

◆ getWidth()

double geos::geom::Envelope::getWidth ( ) const

inline

Returns the difference between the maximum and minimum x values.

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

◆ init() [1/3]

void geos::geom::Envelope::init ( const CoordinateXY & p )

inline

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

Parameters

p	the Coordinate

◆ init() [2/3]

void geos::geom::Envelope::init	(	const CoordinateXY &	p1,
		const CoordinateXY &	p2
	)

inline

Initialize an Envelope to a region defined by two Coordinates.

Parameters

p1	the first Coordinate
p2	the second Coordinate

◆ init() [3/3]

void geos::geom::Envelope::init	(	double	x1,
		double	x2,
		double	y1,
		double	y2
	)

inline

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

◆ intersection()

bool geos::geom::Envelope::intersection	(	const Envelope &	env,
		Envelope &	result
	)		const

Computes the intersection of two Envelopes.

Parameters

env	the envelope to intersect with
result	the envelope representing the intersection of the envelopes (this will be the null envelope if either argument is null, or they do not intersect)

Returns: false if no intersection is found

◆ intersects() [1/6]

bool geos::geom::Envelope::intersects	(	const CoordinateXY &	a,
		const CoordinateXY &	b
	)		const

Check if the extent defined by two extremal points intersects the extent of this Envelope.

Parameters

a	a point
b	another point

Returns: true if the extents intersect

◆ intersects() [2/6]

bool geos::geom::Envelope::intersects ( const CoordinateXY & other ) const

inline

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

Parameters

other the Coordinate to be tested

Returns: true if the point intersects this Envelope

◆ intersects() [3/6]

static bool geos::geom::Envelope::intersects	(	const CoordinateXY &	p1,
		const CoordinateXY &	p2,
		const CoordinateXY &	q
	)

static

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

Referenced by geos::operation::cluster::EnvelopeIntersectsClusterFinder::shouldJoin().

◆ intersects() [4/6]

static bool geos::geom::Envelope::intersects	(	const CoordinateXY &	p1,
		const CoordinateXY &	p2,
		const CoordinateXY &	q1,
		const CoordinateXY &	q2
	)

inlinestatic

Test the envelope defined by p1-p2 for intersection with the envelope defined by q1-q2.

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

◆ intersects() [5/6]

bool geos::geom::Envelope::intersects ( const Envelope * other ) const

inline

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

Parameters

other the Envelope which this Envelope is being checked for intersection

Returns: true if the Envelopes intersects

◆ intersects() [6/6]

bool geos::geom::Envelope::intersects	(	double	x,
		double	y
	)		const

inline

Check if the point (x, y) intersects (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 intersects this Envelope

◆ isfinite()

bool geos::geom::Envelope::isfinite ( ) const

Returns true if all the extents of the Envelope are finite and defined (not NaN)

Returns: true if envelope has only finite/valid extents, false otherwise

◆ isNull()

bool geos::geom::Envelope::isNull ( void ) const

inline

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

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

◆ toString()

std::string geos::geom::Envelope::toString ( ) const

Returns a string of the form Env[minx:maxx,miny:maxy].

Returns: a string of the form Env[minx:maxx,miny:maxy]

◆ translate()

void geos::geom::Envelope::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

Friends And Related Symbol Documentation

◆ operator<

bool operator<	(	const Envelope &	a,
		const Envelope &	b
	)

friend

Strict weak ordering operator for Envelope This is the C++ equivalent of JTS's compareTo

The documentation for this class was generated from the following file:

Envelope.h

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Envelope() [1/3]

◆ Envelope() [2/3]

◆ Envelope() [3/3]

Member Function Documentation

◆ centre()

◆ contains() [1/3]

◆ contains() [2/3]

◆ contains() [3/3]

◆ covers() [1/3]

◆ covers() [2/3]

◆ covers() [3/3]

◆ disjoint()

◆ distance()

◆ distanceSquared()

◆ distanceSquaredToCoordinate()

◆ distanceToCoordinate()

◆ equals()

◆ expandBy() [1/2]

◆ expandBy() [2/2]

◆ expandToInclude() [1/3]

◆ expandToInclude() [2/3]

◆ expandToInclude() [3/3]

◆ getArea()

◆ getDiameter()

◆ getHeight()

◆ getWidth()

◆ init() [1/3]

◆ init() [2/3]

◆ init() [3/3]

◆ intersection()

◆ intersects() [1/6]

◆ intersects() [2/6]

◆ intersects() [3/6]

◆ intersects() [4/6]

◆ intersects() [5/6]

◆ intersects() [6/6]

◆ isfinite()

◆ isNull()

◆ toString()

◆ translate()

Friends And Related Symbol Documentation

◆ operator<