Unions a collection of Geometry or a single Geometry (which may be a collection) together. More...

#include <UnaryUnionOp.h>

Collaboration diagram for geos::operation::geounion::UnaryUnionOp:

Public Member Functions
template<class T >
	UnaryUnionOp (const T &geoms, geom::GeometryFactory &geomFactIn)

template<class T >
	UnaryUnionOp (const T &geoms)

	UnaryUnionOp (const geom::Geometry &geom)

void	setUnionFunction (UnionStrategy *unionFun)

std::unique_ptr< geom::Geometry >	Union ()
	Gets the union of the input geometries. More...

Static Public Member Functions
template<typename T >
static std::unique_ptr< geom::Geometry >	Union (const T &geoms)

template<class T >
static std::unique_ptr< geom::Geometry >	Union (const T &geoms, geom::GeometryFactory &geomFact)

static std::unique_ptr< geom::Geometry >	Union (const geom::Geometry &geom)

Private Member Functions
template<typename T >
void	extractGeoms (const T &geoms)

void	extract (const geom::Geometry &geom)

std::unique_ptr< geom::Geometry >	unionNoOpt (const geom::Geometry &g0)

std::unique_ptr< geom::Geometry >	unionWithNull (std::unique_ptr< geom::Geometry > g0, std::unique_ptr< geom::Geometry > g1)

Private Attributes
std::vector< const geom::Polygon * >	polygons

std::vector< const geom::LineString * >	lines

std::vector< const geom::Point * >	points

const geom::GeometryFactory *	geomFact

std::unique_ptr< geom::Geometry >	empty

UnionStrategy *	unionFunction

ClassicUnionStrategy	defaultUnionFunction

Detailed Description

Unions a collection of Geometry or a single Geometry (which may be a collection) together.

By using this special-purpose operation over a collection of geometries it is possible to take advantage of various optimizations to improve performance. Heterogeneous GeometryCollections are fully supported.

The result obeys the following contract:

Unioning a set of overlapping Polygons has the effect of merging the areas (i.e. the same effect as iteratively unioning all individual polygons together).
Unioning a set of LineStrings has the effect of fully noding and dissolving the input linework. In this context "fully noded" means that there will be a node or endpoint in the output for every endpoint or line segment crossing in the input. "Dissolved" means that any duplicate (e.g. coincident) line segments or portions of line segments will be reduced to a single line segment in the output. This is consistent with the semantics of the Geometry::Union(Geometry* ) operation. If merged linework is required, the LineMerger class can be used.
Unioning a set of Points has the effect of merging all identical points (producing a set with no duplicates).

UnaryUnion always operates on the individual components of MultiGeometries. So it is possible to use it to "clean" invalid self-intersecting MultiPolygons (although the polygon components must all still be individually valid.)

Definition at line 89 of file UnaryUnionOp.h.

Constructor & Destructor Documentation

template<class T >

geos::operation::geounion::UnaryUnionOp::UnaryUnionOp	(	const T &	geoms,
		geom::GeometryFactory &	geomFactIn
	)

inline

Definition at line 117 of file UnaryUnionOp.h.

template<class T >

geos::operation::geounion::UnaryUnionOp::UnaryUnionOp ( const T & geoms )

inline

Definition at line 125 of file UnaryUnionOp.h.

geos::operation::geounion::UnaryUnionOp::UnaryUnionOp ( const geom::Geometry & geom )

inline

Definition at line 132 of file UnaryUnionOp.h.

Member Function Documentation

void geos::operation::geounion::UnaryUnionOp::extract ( const geom::Geometry & geom )

inlineprivate

Definition at line 173 of file UnaryUnionOp.h.

References geos::geom::Geometry::getFactory().

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template<typename T >

void geos::operation::geounion::UnaryUnionOp::extractGeoms ( const T & geoms )

inlineprivate

Definition at line 160 of file UnaryUnionOp.h.

void geos::operation::geounion::UnaryUnionOp::setUnionFunction ( UnionStrategy * unionFun )

inline

Definition at line 139 of file UnaryUnionOp.h.

template<typename T >

static std::unique_ptr<geom::Geometry> geos::operation::geounion::UnaryUnionOp::Union ( const T & geoms )

inlinestatic

Definition at line 94 of file UnaryUnionOp.h.

References Union().

Referenced by Union().

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template<class T >

static std::unique_ptr<geom::Geometry> geos::operation::geounion::UnaryUnionOp::Union	(	const T &	geoms,
		geom::GeometryFactory &	geomFact
	)

inlinestatic

Definition at line 102 of file UnaryUnionOp.h.

References Union().

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static std::unique_ptr<geom::Geometry> geos::operation::geounion::UnaryUnionOp::Union ( const geom::Geometry & geom )

inlinestatic

Definition at line 110 of file UnaryUnionOp.h.

References Union().

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std::unique_ptr<geom::Geometry> geos::operation::geounion::UnaryUnionOp::Union ( )

Gets the union of the input geometries.

If no input geometries were provided, an empty GEOMETRYCOLLECTION is returned.

Returns: a Geometry containing the union; an empty GEOMETRYCOLLECTION if no geometries were provided in the input

std::unique_ptr<geom::Geometry> geos::operation::geounion::UnaryUnionOp::unionNoOpt ( const geom::Geometry & g0 )

inlineprivate

Computes a unary union with no extra optimization, and no short-circuiting. Due to the way the overlay operations are implemented, this is still efficient in the case of linear and puntal geometries. Uses robust version of overlay operation to ensure identical behaviour to the union(Geometry) operation.

Parameters

g0	a geometry

Returns: the union of the input geometry

Definition at line 199 of file UnaryUnionOp.h.

std::unique_ptr<geom::Geometry> geos::operation::geounion::UnaryUnionOp::unionWithNull	(	std::unique_ptr< geom::Geometry >	g0,
		std::unique_ptr< geom::Geometry >	g1
	)

private

Computes the union of two geometries, either of both of which may be null.

Parameters

g0	a Geometry (ownership transferred)
g1	a Geometry (ownership transferred)

Returns: the union of the input(s); null if both inputs are null

Member Data Documentation

ClassicUnionStrategy geos::operation::geounion::UnaryUnionOp::defaultUnionFunction

private

Definition at line 234 of file UnaryUnionOp.h.

std::unique_ptr<geom::Geometry> geos::operation::geounion::UnaryUnionOp::empty

private

Definition at line 231 of file UnaryUnionOp.h.

const geom::GeometryFactory* geos::operation::geounion::UnaryUnionOp::geomFact

private

Definition at line 230 of file UnaryUnionOp.h.

std::vector<const geom::LineString*> geos::operation::geounion::UnaryUnionOp::lines

private

Definition at line 227 of file UnaryUnionOp.h.

std::vector<const geom::Point*> geos::operation::geounion::UnaryUnionOp::points

private

Definition at line 228 of file UnaryUnionOp.h.

std::vector<const geom::Polygon*> geos::operation::geounion::UnaryUnionOp::polygons

private

Definition at line 226 of file UnaryUnionOp.h.

UnionStrategy* geos::operation::geounion::UnaryUnionOp::unionFunction

private

Definition at line 233 of file UnaryUnionOp.h.

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

UnaryUnionOp.h

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation