Represents a ring of PolygonizeDirectedEdge which form a ring of a polygon. The ring may be either an outer shell or a hole. More...

#include <EdgeRing.h>

Public Member Functions
void	add (const PolygonizeDirectedEdge *de)
	Adds a DirectedEdge which is known to form part of this ring.

EdgeRing *	findEdgeRingContaining (const std::vector< EdgeRing * > &erList)
	Find the innermost enclosing shell EdgeRing containing this, if any.

	EdgeRing (const geom::GeometryFactory *newFactory)

void	build (PolygonizeDirectedEdge *startDE)

void	computeHole ()

const DeList &	getEdges () const

bool	isHole () const
	Tests whether this ring is a hole.

bool	isIncludedSet () const

bool	isIncluded () const

void	setIncluded (bool included)

bool	isProcessed () const

void	setProcessed (bool processed)

void	setShell (EdgeRing *shellRing)
	Sets the containing shell ring of a ring that has been determined to be a hole.

bool	hasShell () const
	Tests whether this ring has a shell assigned to it.

EdgeRing *	getShell ()
	Gets the shell for this ring. The shell is the ring itself if it is not a hole, otherwise it is the parent shell.

bool	isOuterHole () const
	Tests whether this ring is an outer hole. A hole is an outer hole if it is not contained by any shell.

bool	isOuterShell () const
	Tests whether this ring is an outer shell.

EdgeRing *	getOuterHole () const
	Gets the outer hole of a shell, if it has one. An outer hole is one that is not contained in any other shell.

void	updateIncludedRecursive ()
	Updates the included status for currently non-included shells based on whether they are adjacent to an included shell.

void	addHole (geom::LinearRing *hole)
	Adds a hole to the polygon formed by this ring.

void	addHole (EdgeRing *holeER)

std::unique_ptr< geom::Polygon >	getPolygon ()
	Computes the Polygon formed by this ring and any contained holes.

bool	isValid () const
	Tests if the LinearRing ring formed by this edge ring is topologically valid.

void	computeValid ()

std::unique_ptr< geom::LineString >	getLineString ()
	Gets the coordinates for this ring as a LineString.

geom::LinearRing *	getRingInternal ()
	Returns this ring as a LinearRing, or null if an Exception occurs while creating it (such as a topology problem).

std::unique_ptr< geom::LinearRing >	getRingOwnership ()
	Returns this ring as a LinearRing, or null if an Exception occurs while creating it (such as a topology problem).

bool	isInRing (const geom::Coordinate &pt)

Static Public Member Functions
static std::vector< PolygonizeDirectedEdge * >	findDirEdgesInRing (PolygonizeDirectedEdge *startDE)
	Traverses a ring of DirectedEdges, accumulating them into a list.

static const geom::Coordinate &	ptNotInList (const geom::CoordinateSequence testPts, const geom::CoordinateSequence pts)
	Finds a point in a list of points which is not contained in another list of points.

static bool	isInList (const geom::Coordinate &pt, const geom::CoordinateSequence *pts)
	Tests whether a given point is in an array of points. Uses a value-based test.

Detailed Description

Represents a ring of PolygonizeDirectedEdge which form a ring of a polygon. The ring may be either an outer shell or a hole.

Member Function Documentation

◆ add()

void geos::operation::polygonize::EdgeRing::add ( const PolygonizeDirectedEdge * de )

Adds a DirectedEdge which is known to form part of this ring.

Parameters

de	the DirectedEdge to add. Ownership to the caller.

◆ addHole()

void geos::operation::polygonize::EdgeRing::addHole ( geom::LinearRing * hole )

Adds a hole to the polygon formed by this ring.

Parameters

hole	the LinearRing forming the hole.

◆ findDirEdgesInRing()

static std::vector< PolygonizeDirectedEdge * > geos::operation::polygonize::EdgeRing::findDirEdgesInRing ( PolygonizeDirectedEdge * startDE )

static

Traverses a ring of DirectedEdges, accumulating them into a list.

This assumes that all dangling directed edges have been removed from the graph, so that there is always a next dirEdge.

Parameters

startDE the DirectedEdge to start traversing at

Returns: a vector of DirectedEdges that form a ring

◆ findEdgeRingContaining()

EdgeRing * geos::operation::polygonize::EdgeRing::findEdgeRingContaining ( const std::vector< EdgeRing * > & erList )

Find the innermost enclosing shell EdgeRing containing this, if any.

The innermost enclosing ring is the smallest enclosing ring. The algorithm used depends on the fact that:

ring A contains ring B iff envelope(ring A) contains envelope(ring B)

This routine is only safe to use if the chosen point of the hole is known to be properly contained in a shell (which is guaranteed to be the case if the hole does not touch its shell)

Returns: containing EdgeRing, if there is one; null if no containing EdgeRing is found

◆ getLineString()

std::unique_ptr< geom::LineString > geos::operation::polygonize::EdgeRing::getLineString ( )

Gets the coordinates for this ring as a LineString.

Used to return the coordinates in this ring as a valid geometry, when it has been detected that the ring is topologically invalid.

Returns: a LineString containing the coordinates in this ring

◆ getOuterHole()

EdgeRing * geos::operation::polygonize::EdgeRing::getOuterHole ( ) const

Gets the outer hole of a shell, if it has one. An outer hole is one that is not contained in any other shell.

Each disjoint connected group of shells is surrounded by an outer hole.

Returns: the outer hole edge ring, or nullptr

◆ getPolygon()

std::unique_ptr< geom::Polygon > geos::operation::polygonize::EdgeRing::getPolygon ( )

Computes the Polygon formed by this ring and any contained holes.

LinearRings ownership is transferred to returned polygon. Subsequent calls to the function will return NULL.

Returns: the Polygon formed by this ring and its holes.

◆ getRingInternal()

geom::LinearRing * geos::operation::polygonize::EdgeRing::getRingInternal ( )

Returns this ring as a LinearRing, or null if an Exception occurs while creating it (such as a topology problem).

Ownership of ring is retained by the object. Details of problems are written to standard output.

◆ getRingOwnership()

std::unique_ptr< geom::LinearRing > geos::operation::polygonize::EdgeRing::getRingOwnership ( )

Returns this ring as a LinearRing, or null if an Exception occurs while creating it (such as a topology problem).

Details of problems are written to standard output. Caller gets ownership of ring.

◆ getShell()

EdgeRing * geos::operation::polygonize::EdgeRing::getShell ( )

inline

Gets the shell for this ring. The shell is the ring itself if it is not a hole, otherwise it is the parent shell.

Returns: the shell for the ring

◆ hasShell()

bool geos::operation::polygonize::EdgeRing::hasShell ( ) const

inline

Tests whether this ring has a shell assigned to it.

Returns: true if the ring has a shell

◆ isHole()

bool geos::operation::polygonize::EdgeRing::isHole ( ) const

inline

Tests whether this ring is a hole.

Due to the way the edges in the polyongization graph are linked, a ring is a hole if it is oriented counter-clockwise.

Returns: true if this ring is a hole

◆ isInList()

static bool geos::operation::polygonize::EdgeRing::isInList	(	const geom::Coordinate &	pt,
		const geom::CoordinateSequence *	pts
	)

static

Tests whether a given point is in an array of points. Uses a value-based test.

Parameters

pt	a Coordinate for the test point
pts	an array of Coordinate to test

Returns: true if the point is in the array

◆ isOuterHole()

bool geos::operation::polygonize::EdgeRing::isOuterHole ( ) const

inline

Tests whether this ring is an outer hole. A hole is an outer hole if it is not contained by any shell.

Returns: true if the ring is an outer hole.

◆ isOuterShell()

bool geos::operation::polygonize::EdgeRing::isOuterShell ( ) const

inline

Tests whether this ring is an outer shell.

Returns: true if the ring is an outer shell.

◆ ptNotInList()

static const geom::Coordinate & geos::operation::polygonize::EdgeRing::ptNotInList	(	const geom::CoordinateSequence *	testPts,
		const geom::CoordinateSequence *	pts
	)

static

Finds a point in a list of points which is not contained in another list of points.

Parameters

testPts	the CoordinateSequence to test
pts	the CoordinateSequence to test the input points against

Returns: a Coordinate reference from testPts which is not in pts, or Coordinate::nullCoord

◆ setShell()

void geos::operation::polygonize::EdgeRing::setShell ( EdgeRing * shellRing )

inline

Sets the containing shell ring of a ring that has been determined to be a hole.

Parameters

shellRing the shell ring

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

operation/polygonize/EdgeRing.h

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ add()

◆ addHole()

◆ findDirEdgesInRing()

◆ findEdgeRingContaining()

◆ getLineString()

◆ getOuterHole()

◆ getPolygon()

◆ getRingInternal()

◆ getRingOwnership()

◆ getShell()

◆ hasShell()

◆ isHole()

◆ isInList()

◆ isOuterHole()

◆ isOuterShell()

◆ ptNotInList()

◆ setShell()