org.geolatte.geom

Class Polygon<P extends Position>

java.lang.Object

org.geolatte.geom.Geometry<P>

org.geolatte.geom.Polygon<P>

All Implemented Interfaces:

Serializable, Iterable<LinearRing<P>>, Complex<P,LinearRing<P>>, Polygonal<P>

public class Polygon<P extends Position>
extends Geometry<P>
implements Polygonal<P>, Complex<P,LinearRing<P>>

A planar surface defined by 1 exterior boundary and 0 or more interior boundaries. Each interior boundary defines a hole in the Polygon.

The exterior boundary LinearRing defines the "top" of the surface which is the side of the surface from which the exterior boundary appears to traverse the boundary in a counter clockwise direction. The interior LinearRings will have the opposite orientation and appear as clockwise when viewed from the "top".

The rules that define valid Polygons are as follows

1. Polygons are topologically closed;
2. The boundary of a Polygon consists of a set of LinearRings that make up its exterior and interior boundaries;
3. No two rings in the boundary cross and the rings in the boundary of a Polygon may intersect at a Point but only as a tangent
4. A Polygon may not have cut lines, spikes or punctures;
5. The interior of every Polygon is a connected point set;
6. The exterior of a Polygon with 1 or more holes is not connected. Each hole defines a connected component of the exterior

Author:

Karel Maesen, Geovise BVBA creation-date: 4/14/11

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Polygon(CoordinateReferenceSystem<P> crs)
Polygon(LinearRing<P>... rings) Creates a Polygon with the specified array of exterior and interior boundaries.
Polygon(PositionSequence<P> positionSequence, CoordinateReferenceSystem<P> crs) Creates a Polygon with no holes, and having the specified PositionSequence as exterior boundary

Method Summary

Modifier and Type	Method and Description
void	accept(GeometryVisitor<P> visitor) Accepts a GeometryVisitor.
Class<? extends Geometry>	getComponentType() Returns the Class of which all constituent Geometrys are instances.
int	getDimension() Returns the topological dimension of this instance.
LinearRing<P>	getExteriorRing() Returns the exterior boundary of this Polygon.
GeometryType	getGeometryType() Returns the type of this Geometry.
LinearRing<P>	getInteriorRingN(int index) Returns the specified interior ring.
int	getNumGeometries() Returns the number of constituent Geometrys
int	getNumInteriorRing() returns the number of interior boundaries.
Iterator<LinearRing<P>>	iterator() Returns an Iterator over the boundaries of this Polygon.

Methods inherited from class org.geolatte.geom.Geometry

equals, forceToCrs, getCoordinateDimension, getCoordinateReferenceSystem, getCrs, getEnvelope, getNumPositions, getPositionClass, getPositionN, getPositions, getSRID, hashCode, isEmpty, nestPositionSequences, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

Polygon

public Polygon(CoordinateReferenceSystem<P> crs)

Polygon

public Polygon(PositionSequence<P> positionSequence,
               CoordinateReferenceSystem<P> crs)

Creates a Polygon with no holes, and having the specified PositionSequence as exterior boundary

Parameters:

positionSequence - the PositionSequence representing the exterior boundary

Throws:

IllegalArgumentException - when the specified PositionSequence does not form a LinearRing (i.e., is empty or not closed).

Polygon

public Polygon(LinearRing<P>... rings)

Creates a Polygon with the specified array of exterior and interior boundaries.

Parameters:

rings - the array of the Polygon's boundaries: the first element is the exterior boundary, all subsequent rings represent interior boundaries.

Throws:

IllegalArgumentException - when the specified PositionSequence does not form a LinearRing (i.e., is empty or not closed).

Method Detail

getExteriorRing

public LinearRing<P> getExteriorRing()

Returns the exterior boundary of this Polygon.

Returns:

a LinearRing representing the exterior boundary of this Polygon.

getNumInteriorRing

public int getNumInteriorRing()

returns the number of interior boundaries.

Returns:

the number of interior boundaries

getInteriorRingN

public LinearRing<P> getInteriorRingN(int index)

Returns the specified interior ring.

Parameters:

index - the (zero-based) position of the interior boundary in the list of interior boundaries.

Returns:

the LinearRing at the position specified by the parameter index.

getDimension

public int getDimension()

Description copied from class: Geometry

Returns the topological dimension of this instance. In non-homogenous collections, this will return the largest topological dimension of the contained Geometries.

Specified by:

getDimension in class Geometry<P extends Position>

Returns:

the topological dimension of this instance

getGeometryType

public GeometryType getGeometryType()

Description copied from class: Geometry

Returns the type of this Geometry.

Specified by:

getGeometryType in class Geometry<P extends Position>

Returns:

the GeometryType of this instance.

iterator

public Iterator<LinearRing<P>> iterator()

Returns an Iterator over the boundaries of this Polygon.

The boundaries are returned in order, with the first element being the exterior boundary.

Specified by:

iterator in interface Iterable<LinearRing<P extends Position>>

Returns:

an Iterator over the boundaries of this Polygon.

accept

public void accept(GeometryVisitor<P> visitor)

Description copied from class: Geometry

Accepts a GeometryVisitor.

If this Geometry instance is a GeometryCollection then it will pass the visitor to its contained Geometries.

Specified by:

accept in class Geometry<P extends Position>

getNumGeometries

public int getNumGeometries()

Description copied from interface: Complex

Returns the number of constituent Geometrys

Specified by:

getNumGeometries in interface Complex<P extends Position,LinearRing<P extends Position>>

Returns:

the number of constituent Geometrys

getComponentType

public Class<? extends Geometry> getComponentType()

Description copied from interface: Complex

Returns the Class of which all constituent Geometrys are instances.

Specified by:

getComponentType in interface Complex<P extends Position,LinearRing<P extends Position>>

Returns:

the Class of which all constituent Geometrys are instances.