Class EdgeRing

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

Inheritance

Object

EdgeRing

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Namespace: NetTopologySuite.Operation.Polygonize

Assembly: NetTopologySuite.dll

Syntax

public class EdgeRing

Constructors

EdgeRing(GeometryFactory)

Declaration

public EdgeRing(GeometryFactory factory)

Parameters

Type	Name	Description
GeometryFactory	factory

Properties

HasShell

Gets a value indicating whether this ring has a shell assigned to it.

Declaration

public bool HasShell { get; }

Property Value

Type	Description
Boolean

IsHole

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

Declaration

public bool IsHole { get; }

Property Value

Type	Description
Boolean	true if this ring is a hole.

IsIncluded

Declaration

public bool IsIncluded { get; set; }

Property Value

Type	Description
Boolean

IsIncludedSet

Declaration

public bool IsIncludedSet { get; }

Property Value

Type	Description
Boolean

IsOuterHole

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

Declaration

public bool IsOuterHole { get; }

Property Value

Type	Description
Boolean

IsOuterShell

Tests whether this ring is an outer shell.

Declaration

public bool IsOuterShell { get; }

Property Value

Type	Description
Boolean

IsProcessed

Gets or sets a value indicating whether this ring has been processed.

Declaration

public bool IsProcessed { get; set; }

Property Value

Type	Description
Boolean

IsValid

Tests if the LinearRing ring formed by this edge ring is topologically valid.

Declaration

public bool IsValid { get; }

Property Value

Type	Description
Boolean

LineString

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

Declaration

public LineString LineString { get; }

Property Value

Type	Description
LineString

OuterHole

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.

Declaration

public EdgeRing OuterHole { get; }

Property Value

Type	Description
EdgeRing	The outer hole edge ring, or null

Polygon

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

Declaration

public Polygon Polygon { get; }

Property Value

Type	Description
Polygon

Ring

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

Declaration

public LinearRing Ring { get; }

Property Value

Type	Description
LinearRing

Shell

Gets or sets a value indicating the containing shell ring of a ring that has been determined to be a hole.

Declaration

public EdgeRing Shell { get; }

Property Value

Type	Description
EdgeRing

Methods

AddHole(LinearRing)

Adds a hole to the polygon formed by this ring.

Declaration

public void AddHole(LinearRing hole)

Parameters

Type	Name	Description
LinearRing	hole	The LinearRing forming the hole.

AddHole(EdgeRing)

Adds a hole to the polygon formed by this ring.

Declaration

public void AddHole(EdgeRing holeER)

Parameters

Type	Name	Description
EdgeRing	holeER	the LinearRing forming the hole.

Build(PolygonizeDirectedEdge)

Declaration

public void Build(PolygonizeDirectedEdge startDE)

Parameters

Type	Name	Description
PolygonizeDirectedEdge	startDE

ComputeHole()

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

Declaration

public void ComputeHole()

FindDirEdgesInRing(PolygonizeDirectedEdge)

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.

Declaration

public static List<DirectedEdge> FindDirEdgesInRing(PolygonizeDirectedEdge startDE)

Parameters

Type	Name	Description
PolygonizeDirectedEdge	startDE	The DirectedEdge to start traversing at

Returns

Type	Description
List<DirectedEdge>	A list of DirectedEdges that form a ring

FindEdgeRingContaining(EdgeRing, IList<EdgeRing>)

Find the innermost enclosing shell EdgeRing containing the argument EdgeRing, if any. The innermost enclosing ring is the smallest enclosing ring. The algorithm used depends on the fact that: ring A contains ring B if 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).

To improve performance of this function the caller should make the passed shellList as small as possible(e.g. by using a spatial index filter beforehand).

Declaration

public static EdgeRing FindEdgeRingContaining(EdgeRing testEr, IList<EdgeRing> erList)

Parameters

Type	Name	Description
EdgeRing	testEr
IList<EdgeRing>	erList

Returns

Type	Description
EdgeRing	Containing EdgeRing, if there is one or null if no containing EdgeRing is found.

IsInRing(Coordinate)

Declaration

public bool IsInRing(Coordinate pt)

Parameters

Type	Name	Description
Coordinate	pt

Returns

Type	Description
Boolean

ToString()

Gets a string representation of this object.

Declaration

public override string ToString()

Returns

Type	Description
String

Overrides

Object.ToString()