Class EdgeRing

Namespace

NetTopologySuite.Operation.Polygonize

Assembly

NetTopologySuite.dll

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

public class EdgeRing

Inheritance

object

EdgeRing

Inherited Members

object.GetType()

object.MemberwiseClone()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Constructors

EdgeRing(GeometryFactory)

public EdgeRing(GeometryFactory factory)

Parameters

factory GeometryFactory

Properties

HasShell

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

public bool HasShell { get; }

Property Value

bool

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.

public bool IsHole { get; }

Property Value

bool

true if this ring is a hole.

IsIncluded

public bool IsIncluded { get; set; }

Property Value

bool

IsIncludedSet

public bool IsIncludedSet { get; }

Property Value

bool

IsOuterHole

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

public bool IsOuterHole { get; }

Property Value

bool

IsOuterShell

Tests whether this ring is an outer shell.

public bool IsOuterShell { get; }

Property Value

bool

IsProcessed

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

public bool IsProcessed { get; set; }

Property Value

bool

IsValid

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

public bool IsValid { get; }

Property Value

bool

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.

public LineString LineString { get; }

Property Value

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.

public EdgeRing OuterHole { get; }

Property Value

EdgeRing

The outer hole edge ring, or null

Polygon

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

public Polygon Polygon { get; }

Property Value

Polygon

Ring

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

public LinearRing Ring { get; }

Property Value

LinearRing

Shell

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

public EdgeRing Shell { get; }

Property Value

EdgeRing

Methods

AddHole(LinearRing)

Adds a hole to the polygon formed by this ring.

public void AddHole(LinearRing hole)

Parameters

hole LinearRing

The LinearRing forming the hole.

AddHole(EdgeRing)

Adds a hole to the polygon formed by this ring.

public void AddHole(EdgeRing holeER)

Parameters

holeER EdgeRing

the LinearRing forming the hole.

Build(PolygonizeDirectedEdge)

public void Build(PolygonizeDirectedEdge startDE)

Parameters

startDE PolygonizeDirectedEdge

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.

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.

public static List<DirectedEdge> FindDirEdgesInRing(PolygonizeDirectedEdge startDE)

Parameters

startDE PolygonizeDirectedEdge

The DirectedEdge to start traversing at

Returns

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).

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

Parameters

testEr EdgeRing

erList IList<EdgeRing>

Returns

EdgeRing

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

IsInRing(Coordinate)

public bool IsInRing(Coordinate pt)

Parameters

pt Coordinate

Returns

bool

ToString()

Gets a string representation of this object.

public override string ToString()

Returns

string