Class Polygon

Represents a polygon with linear edges, which may include holes. The outer boundary (shell) and inner boundaries (holes) of the polygon are represented by {@link LinearRing}s. The boundary rings of the polygon may have any orientation. Polygons are closed, simple geometries by definition.

The polygon model conforms to the assertions specified in the OpenGIS Simple Features Specification for SQL.

A Polygon is topologically valid if and only if:

• the coordinates which define it are valid coordinates
• the linear rings for the shell and holes are valid (i.e. are closed and do not self-intersect)
• holes touch the shell or another hole at at most one point (which implies that the rings of the shell and holes must not cross)
• the interior of the polygon is connected, or equivalently no sequence of touching holes makes the interior of the polygon disconnected (i.e. effectively split the polygon into two pieces).

Inheritance

object

Geometry

Polygon

Implements

IComparable

IComparable<Geometry>

IPolygonal

Inherited Members

Geometry.TypeNamePoint

Geometry.TypeNameMultiPoint

Geometry.TypeNameLineString

Geometry.TypeNameLinearRing

Geometry.TypeNameMultiLineString

Geometry.TypeNamePolygon

Geometry.TypeNameMultiPolygon

Geometry.TypeNameGeometryCollection

Geometry.Factory

Geometry.UserData

Geometry.SRID

Geometry.HasNonEmptyElements(Geometry[])

Geometry.HasNullElements(object[])

Geometry.HasNullElements<T>(IEnumerable<T>)

Geometry.PrecisionModel

Geometry.NumGeometries

Geometry.GetGeometryN(int)

Geometry.IsSimple

Geometry.IsValid

Geometry.Distance(Geometry)

Geometry.IsWithinDistance(Geometry, double)

Geometry.Centroid

Geometry.InteriorPoint

Geometry.PointOnSurface

Geometry.HasDimension(Dimension)

Geometry.Envelope

Geometry.EnvelopeInternal

Geometry.GeometryChanged()

Geometry.GeometryChangedAction()

Geometry.Disjoint(Geometry)

Geometry.Touches(Geometry)

Geometry.Intersects(Geometry)

Geometry.Crosses(Geometry)

Geometry.Within(Geometry)

Geometry.Contains(Geometry)

Geometry.Overlaps(Geometry)

Geometry.Covers(Geometry)

Geometry.CoveredBy(Geometry)

Geometry.Relate(Geometry, string)

Geometry.Relate(Geometry)

Geometry.Equals(Geometry)

Geometry.EqualsTopologically(Geometry)

Geometry.Equals(object)

Geometry.GetHashCode()

Geometry.ToString()

Geometry.ToText()

Geometry.AsText()

Geometry.ToBinary()

Geometry.AsBinary()

Geometry.ToGMLFeature()

Geometry.Buffer(double)

Geometry.Buffer(double, EndCapStyle)

Geometry.Buffer(double, int)

Geometry.Buffer(double, int, EndCapStyle)

Geometry.Buffer(double, BufferParameters)

Geometry.Intersection(Geometry)

Geometry.Union(Geometry)

Geometry.Difference(Geometry)

Geometry.SymmetricDifference(Geometry)

Geometry.Union()

Geometry.EqualsExact(Geometry)

Geometry.EqualsNormalized(Geometry)

Geometry.Copy()

Geometry.Normalized()

Geometry.CompareTo(object)

Geometry.CompareTo(Geometry)

Geometry.CompareTo(object, IComparer<CoordinateSequence>)

Geometry.IsEquivalentClass(Geometry)

Geometry.CheckNotGeometryCollection(Geometry)

Geometry.IsGeometryCollection

Geometry.Compare(List<Geometry>, List<Geometry>)

Geometry.Equal(Coordinate, Coordinate, double)

Geometry.DefaultFactory

Geometry.CreateArray(int, double)

Geometry.CreateArray(CoordinateSequence, Ordinate)

object.Equals(object, object)

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: NetTopologySuite.Geometries

Assembly: NetTopologySuite.dll

Syntax

[Serializable]
public class Polygon : Geometry, IComparable, IComparable<Geometry>, IPolygonal

Constructors

Polygon(LinearRing)

Constructs a Polygon with the given exterior boundary.

Declaration

public Polygon(LinearRing shell)

Parameters

Type	Name	Description
LinearRing	shell	The outer boundary of the new Polygon, or null or an empty LinearRing if the empty polygon is to be created.

Polygon(LinearRing, GeometryFactory)

Constructs a Polygon with the given exterior boundary.

Declaration

public Polygon(LinearRing shell, GeometryFactory factory)

Parameters

Type	Name	Description
LinearRing	shell	The outer boundary of the new Polygon, or null or an empty LinearRing if the empty polygon is to be created.
GeometryFactory	factory

Polygon(LinearRing, LinearRing[])

Initializes a new instance of the Polygon class.

Declaration

public Polygon(LinearRing shell, LinearRing[] holes)

Parameters

Type	Name	Description
LinearRing	shell	The outer boundary of the new Polygon, or null or an empty LinearRing if the empty point is to be created.
LinearRing[]	holes	The inner boundaries of the new Polygon , or null or empty LinearRings if the empty point is to be created.

Remarks

For create this Geometry is used a standard GeometryFactory with PrecisionModel == Floating.

Polygon(LinearRing, LinearRing[], GeometryFactory)

Constructs a Polygon with the given exterior boundary and interior boundaries.

Declaration

public Polygon(LinearRing shell, LinearRing[] holes, GeometryFactory factory)

Parameters

Type	Name	Description
LinearRing	shell	The outer boundary of the new Polygon, or null or an empty LinearRing if the empty point is to be created.
LinearRing[]	holes	The inner boundaries of the new Polygon , or null or empty LinearRings if the empty point is to be created.
GeometryFactory	factory

Fields

Empty

Represents an empty Polygon.

Declaration

public static readonly Polygon Empty

Field Value

Type	Description
Polygon

Properties

Area

Returns the area of this Polygon

Declaration

public override double Area { get; }

Property Value

Type	Description
double

Overrides

Geometry.Area

Boundary

Declaration

public override Geometry Boundary { get; }

Property Value

Type	Description
Geometry

Overrides

Geometry.Boundary

BoundaryDimension

Returns the dimension of this Geometrys inherent boundary.

Declaration

public override Dimension BoundaryDimension { get; }

Property Value

Type	Description
Dimension	The dimension of the boundary of the class implementing this interface, whether or not this object is the empty point. Returns Dimension.False if the boundary is the empty point.

Overrides

Geometry.BoundaryDimension

Coordinate

Returns a vertex of this Geometry (usually, but not necessarily, the first one).

Declaration

public override Coordinate Coordinate { get; }

Property Value

Type	Description
Coordinate	a Coordinate which is a vertex of this Geometry.

Overrides

Geometry.Coordinate

Remarks

The returned coordinate should not be assumed to be an actual Coordinate object used in the internal representation.

Coordinates

Returns an array containing the values of all the vertices for this geometry.

Declaration

public override Coordinate[] Coordinates { get; }

Property Value

Type	Description
Coordinate[]	The vertices of this Geometry.

Overrides

Geometry.Coordinates

Remarks

If the geometry is a composite, the array will contain all the vertices for the components, in the order in which the components occur in the geometry.

In general, the array cannot be assumed to be the actual internal storage for the vertices. Thus modifying the array may not modify the geometry itself. Use the SetOrdinate(int, int, double) method (possibly on the components) to modify the underlying data. If the coordinates are modified, GeometryChanged() must be called afterwards.

See Also

GeometryChanged()

SetOrdinate(int, int, double)

SetOrdinate(int, Ordinate, double)

Dimension

Returns the dimension of this geometry.

Declaration

public override Dimension Dimension { get; }

Property Value

Type	Description
Dimension	The topological dimensions of this geometry

Overrides

Geometry.Dimension

Remarks

The dimension of a geometry is is the topological dimension of its embedding in the 2-D Euclidean plane. In the NTS spatial model, dimension values are in the set {0,1,2}.

Note that this is a different concept to the dimension of the vertex Coordinates. The geometry dimension can never be greater than the coordinate dimension. For example, a 0-dimensional geometry (e.g. a Point) may have a coordinate dimension of 3 (X,Y,Z).

ExteriorRing

Declaration

public LineString ExteriorRing { get; }

Property Value

Type	Description
LineString

GeometryType

Returns the name of this object's interface.

Declaration

public override string GeometryType { get; }

Property Value

Type	Description
string	"Polygon"

Overrides

Geometry.GeometryType

Holes

Declaration

public LinearRing[] Holes { get; }

Property Value

Type	Description
LinearRing[]

InteriorRings

Declaration

public LineString[] InteriorRings { get; }

Property Value

Type	Description
LineString[]

IsEmpty

Declaration

public override bool IsEmpty { get; }

Property Value

Type	Description
bool

Overrides

Geometry.IsEmpty

IsRectangle

Tests whether this is a rectangular Polygon.

Declaration

public override bool IsRectangle { get; }

Property Value

Type	Description
bool	true if the geometry is a rectangle.

Overrides

Geometry.IsRectangle

Length

Returns the perimeter of this Polygon.

Declaration

public override double Length { get; }

Property Value

Type	Description
double

Overrides

Geometry.Length

NumInteriorRings

Declaration

public int NumInteriorRings { get; }

Property Value

Type	Description
int

NumPoints

Returns the count of this Geometrys vertices. The Geometry s contained by composite Geometrys must be Geometry's; that is, they must implement NumPoints.

Declaration

public override int NumPoints { get; }

Property Value

Type	Description
int	The number of vertices in this Geometry.

Overrides

Geometry.NumPoints

OgcGeometryType

Gets the OGC geometry type

Declaration

public override OgcGeometryType OgcGeometryType { get; }

Property Value

Type	Description
OgcGeometryType

Overrides

Geometry.OgcGeometryType

Shell

Declaration

public LinearRing Shell { get; }

Property Value

Type	Description
LinearRing

SortIndex

Gets a value to sort the geometry

Declaration

protected override Geometry.SortIndexValue SortIndex { get; }

Property Value

Type	Description
Geometry.SortIndexValue

Overrides

Geometry.SortIndex

Remarks

NOTE:
For JTS v1.17 this property's getter has been renamed to getTypeCode(). In order not to break binary compatibility we did not follow.

Methods

Apply(ICoordinateFilter)

Performs an operation with or on this Geometry's coordinates.

Declaration

public override void Apply(ICoordinateFilter filter)

Parameters

Type	Name	Description
ICoordinateFilter	filter	The filter to apply to this Geometry's coordinates

Overrides

Geometry.Apply(ICoordinateFilter)

Remarks

If this method modifies any coordinate values, GeometryChanged() must be called to update the geometry state. Note that you cannot use this method to modify this Geometry if its underlying CoordinateSequence's #get method returns a copy of the Coordinate, rather than the actual Coordinate stored (if it even stores Coordinate objects at all).

Apply(ICoordinateSequenceFilter)

Performs an operation on the coordinates in this Geometry's CoordinateSequences.

Declaration

public override void Apply(ICoordinateSequenceFilter filter)

Parameters

Type	Name	Description
ICoordinateSequenceFilter	filter	The filter to apply

Overrides

Geometry.Apply(ICoordinateSequenceFilter)

Remarks

If the filter reports that a coordinate value has been changed, GeometryChanged() will be called automatically.

Apply(IEntireCoordinateSequenceFilter)

Performs an operation on this Geometry's CoordinateSequences.

Declaration

public override void Apply(IEntireCoordinateSequenceFilter filter)

Parameters

Type	Name	Description
IEntireCoordinateSequenceFilter	filter	The filter to apply

Overrides

Geometry.Apply(IEntireCoordinateSequenceFilter)

Remarks

If the filter reports that a coordinate value has been changed, GeometryChanged() will be called automatically.

Apply(IGeometryComponentFilter)

Performs an operation with or on this Geometry and its component Geometry's. Only GeometryCollections and Polygons have component Geometry's; for Polygons they are the LinearRings of the shell and holes.

Declaration

public override void Apply(IGeometryComponentFilter filter)

Parameters

Type	Name	Description
IGeometryComponentFilter	filter	The filter to apply to this Geometry.

Overrides

Geometry.Apply(IGeometryComponentFilter)

Apply(IGeometryFilter)

Performs an operation with or on this Geometry and its subelement Geometrys (if any). Only GeometryCollections and subclasses have subelement Geometry's.

Declaration

public override void Apply(IGeometryFilter filter)

Parameters

Type	Name	Description
IGeometryFilter	filter	The filter to apply to this Geometry (and its children, if it is a GeometryCollection).

Overrides

Geometry.Apply(IGeometryFilter)

CompareToSameClass(object)

Declaration

protected override int CompareToSameClass(object o)

Parameters

Type	Name	Description
object	o

Returns

Type	Description
int

Overrides

Geometry.CompareToSameClass(object)

CompareToSameClass(object, IComparer<CoordinateSequence>)

Declaration

protected override int CompareToSameClass(object other, IComparer<CoordinateSequence> comparer)

Parameters

Type	Name	Description
object	other
IComparer<CoordinateSequence>	comparer

Returns

Type	Description
int

Overrides

Geometry.CompareToSameClass(object, IComparer<CoordinateSequence>)

ComputeEnvelopeInternal()

Declaration

protected override Envelope ComputeEnvelopeInternal()

Returns

Type	Description
Envelope

Overrides

Geometry.ComputeEnvelopeInternal()

ConvexHull()

Declaration

public override Geometry ConvexHull()

Returns

Type	Description
Geometry

Overrides

Geometry.ConvexHull()

CopyInternal()

An internal method to copy subclass-specific geometry data.

Declaration

protected override Geometry CopyInternal()

Returns

Type	Description
Geometry	A copy of the target geometry object.

Overrides

Geometry.CopyInternal()

EqualsExact(Geometry, double)

Declaration

public override bool EqualsExact(Geometry other, double tolerance)

Parameters

Type	Name	Description
Geometry	other
double	tolerance

Returns

Type	Description
bool

Overrides

Geometry.EqualsExact(Geometry, double)

GetInteriorRingN(int)

Declaration

public LineString GetInteriorRingN(int n)

Parameters

Type	Name	Description
int	n

Returns

Type	Description
LineString

GetOrdinates(Ordinate)

Gets an array of double ordinate values

Declaration

public override double[] GetOrdinates(Ordinate ordinate)

Parameters

Type	Name	Description
Ordinate	ordinate	The ordinate index

Returns

Type	Description
double[]	An array of ordinate values

Overrides

Geometry.GetOrdinates(Ordinate)

Normalize()

Declaration

public override void Normalize()

Overrides

Geometry.Normalize()

Reverse()

Computes a new geometry which has all component coordinate sequences in reverse order (opposite orientation) to this one.

Declaration

[Obsolete("Call Geometry.Reverse()")]
public override Geometry Reverse()

Returns

Type	Description
Geometry	A reversed geometry

Overrides

Geometry.Reverse()

Remarks

Don't override this function, implement ReverseInternal().

ReverseInternal()

The actual implementation of the Reverse() function for POLYGONs

Declaration

protected override Geometry ReverseInternal()

Returns

Type	Description
Geometry	A reversed geometry

Overrides

Geometry.ReverseInternal()

Implements

IComparable

IComparable<T>

IPolygonal

Extension Methods

PolygonalExtracter.GetPolygonals<TCollection>(Geometry)

PolygonalExtracter.GetPolygonals<TCollection>(Geometry, TCollection)