com.vividsolutions.jts.geom
Class Polygon

java.lang.Object
  com.vividsolutions.jts.geom.Geometry
      com.vividsolutions.jts.geom.Polygon

All Implemented Interfaces:

Polygonal, java.io.Serializable, java.lang.Cloneable, java.lang.Comparable

public class Polygon
extends Geometry
implements Polygonal

Represents a linear polygon, which may include holes. The shell and holes of the polygon are represented by LinearRings. In a valid polygon, holes may touch the shell or other holes at a single point. However, no sequence of touching holes may split the polygon into two pieces. The orientation of the rings in the polygon does not matter.

The shell and holes must conform to the assertions specified in the OpenGIS Simple Features Specification for SQL .

Version:

1.7

See Also:

Serialized Form

Field Summary

protected LinearRing[]	holes The interior boundaries, if any.
protected LinearRing	shell The exterior boundary, or null if this Polygon is empty.

Fields inherited from class com.vividsolutions.jts.geom.Geometry

envelope, factory, SRID

Constructor Summary

Polygon(LinearRing shell, LinearRing[] holes, GeometryFactory factory)
Constructs a Polygon with the given exterior boundary and interior boundaries.

Polygon(LinearRing shell, LinearRing[] holes, PrecisionModel precisionModel, int SRID)
Deprecated. Use GeometryFactory instead

Polygon(LinearRing shell, PrecisionModel precisionModel, int SRID)
Deprecated. Use GeometryFactory instead

Method Summary

void	apply(CoordinateFilter filter) Performs an operation with or on this Geometry's coordinates.
void	apply(CoordinateSequenceFilter filter) Performs an operation on the coordinates in this Geometry's CoordinateSequences.
void	apply(GeometryComponentFilter filter) Performs an operation with or on this Geometry and its component Geometry's.
void	apply(GeometryFilter filter) Performs an operation with or on this Geometry and its subelement Geometrys (if any).
java.lang.Object	clone() Creates and returns a full copy of this Polygon object.
protected int	compareToSameClass(java.lang.Object o) Returns whether this Geometry is greater than, equal to, or less than another Geometry having the same class.
protected int	compareToSameClass(java.lang.Object o, CoordinateSequenceComparator comp) Returns whether this Geometry is greater than, equal to, or less than another Geometry of the same class.
protected Envelope	computeEnvelopeInternal() Returns the minimum and maximum x and y values in this Geometry , or a null Envelope if this Geometry is empty.
Geometry	convexHull() Computes the smallest convex Polygon that contains all the points in the Geometry.
boolean	equalsExact(Geometry other, double tolerance) Returns true if the two Geometrys are exactly equal, up to a specified distance tolerance.
double	getArea() Returns the area of this Polygon
Geometry	getBoundary() Computes the boundary of this geometry
int	getBoundaryDimension() Returns the dimension of this Geometrys inherent boundary.
Coordinate	getCoordinate() Returns a vertex of this Geometry (usually, but not necessarily, the first one).
Coordinate[]	getCoordinates() Returns an array containing the values of all the vertices for this geometry.
int	getDimension() Returns the dimension of this geometry.
LineString	getExteriorRing()
java.lang.String	getGeometryType() Returns the name of this object's com.vivid.jts.geom interface.
LineString	getInteriorRingN(int n)
double	getLength() Returns the perimeter of this Polygon
int	getNumInteriorRing()
int	getNumPoints() Returns the count of this Geometrys vertices.
boolean	isEmpty() Returns whether or not the set of points in this Geometry is empty.
boolean	isRectangle()
boolean	isSimple() Tests if a valid polygon is simple.
void	normalize() Converts this Geometry to normal form (or canonical form ).
Geometry	reverse() Computes a new geometry which has all component coordinate sequences in reverse order (opposite orientation) to this one.

Methods inherited from class com.vividsolutions.jts.geom.Geometry

buffer, buffer, buffer, checkNotGeometryCollection, compare, compareTo, compareTo, contains, coveredBy, covers, crosses, difference, disjoint, distance, equal, equals, equals, equalsExact, equalsNorm, equalsTopo, geometryChanged, geometryChangedAction, getCentroid, getEnvelope, getEnvelopeInternal, getFactory, getGeometryN, getInteriorPoint, getNumGeometries, getPrecisionModel, getSRID, getUserData, hashCode, hasNonEmptyElements, hasNullElements, intersection, intersects, isEquivalentClass, isGeometryCollection, isValid, isWithinDistance, norm, overlaps, relate, relate, setSRID, setUserData, symDifference, toString, toText, touches, union, union, within

Methods inherited from class java.lang.Object

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

Field Detail

shell

protected LinearRing shell

The exterior boundary, or null if this Polygon is empty.

holes

protected LinearRing[] holes

The interior boundaries, if any. This instance var is never null. If there are no holes, the array is of zero length.

Constructor Detail

Polygon

public Polygon(LinearRing shell,
               PrecisionModel precisionModel,
               int SRID)

Deprecated. Use GeometryFactory instead

Constructs a Polygon with the given exterior boundary.

Parameters:

shell - the outer boundary of the new Polygon, or null or an empty LinearRing if the empty geometry is to be created.

precisionModel - the specification of the grid of allowable points for this Polygon

SRID - the ID of the Spatial Reference System used by this Polygon

Polygon

public Polygon(LinearRing shell,
               LinearRing[] holes,
               PrecisionModel precisionModel,
               int SRID)

Deprecated. Use GeometryFactory instead

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

Parameters:

shell - the outer boundary of the new Polygon, or null or an empty LinearRing if the empty geometry is to be created.

holes - the inner boundaries of the new Polygon , or null or empty LinearRings if the empty geometry is to be created.

precisionModel - the specification of the grid of allowable points for this Polygon

SRID - the ID of the Spatial Reference System used by this Polygon

Polygon

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

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

Parameters:

shell - the outer boundary of the new Polygon, or null or an empty LinearRing if the empty geometry is to be created.

holes - the inner boundaries of the new Polygon , or null or empty LinearRings if the empty geometry is to be created.

Method Detail

getCoordinate

public Coordinate getCoordinate()

Description copied from class: Geometry

Returns a vertex of this Geometry (usually, but not necessarily, the first one). The returned coordinate should not be assumed to be an actual Coordinate object used in the internal representation.

Specified by:

getCoordinate in class Geometry

Returns:

a Coordinate which is a vertex of this Geometry.

getCoordinates

public Coordinate[] getCoordinates()

Description copied from class: Geometry

Returns an array containing the values of all the vertices for this geometry. 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 CoordinateSequence.setOrdinate(int, int, double) method (possibly on the components) to modify the underlying data. If the coordinates are modified, Geometry.geometryChanged() must be called afterwards.

Specified by:

getCoordinates in class Geometry

Returns:

the vertices of this Geometry

See Also:

Geometry.geometryChanged(), CoordinateSequence.setOrdinate(int, int, double)

getNumPoints

public int getNumPoints()

Description copied from class: Geometry

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

Specified by:

getNumPoints in class Geometry

Returns:

the number of vertices in this Geometry

getDimension

public int getDimension()

Description copied from class: Geometry

Returns the dimension of this geometry. The dimension of a geometry is is the topological dimension of its embedding in the 2-D Euclidean plane. In the JTS 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).

Specified by:

getDimension in class Geometry

Returns:

the topological dimension of this geometry.

getBoundaryDimension

public int getBoundaryDimension()

Description copied from class: Geometry

Returns the dimension of this Geometrys inherent boundary.

Specified by:

getBoundaryDimension in class Geometry

Returns:

the dimension of the boundary of the class implementing this interface, whether or not this object is the empty geometry. Returns Dimension.FALSE if the boundary is the empty geometry.

isEmpty

public boolean isEmpty()

Description copied from class: Geometry

Returns whether or not the set of points in this Geometry is empty.

Specified by:

isEmpty in class Geometry

Returns:

true if this Geometry equals the empty geometry

isSimple

public boolean isSimple()

Tests if a valid polygon is simple. This method always returns true, since a valid polygon is always simple

Overrides:

isSimple in class Geometry

Returns:

true

See Also:

Geometry.isValid()

isRectangle

public boolean isRectangle()

Overrides:

isRectangle in class Geometry

getExteriorRing

public LineString getExteriorRing()

getNumInteriorRing

public int getNumInteriorRing()

getInteriorRingN

public LineString getInteriorRingN(int n)

getGeometryType

public java.lang.String getGeometryType()

Description copied from class: Geometry

Returns the name of this object's com.vivid.jts.geom interface.

Specified by:

getGeometryType in class Geometry

Returns:

the name of this Geometrys most specific com.vividsolutions.jts.geom interface

getArea

public double getArea()

Returns the area of this Polygon

Overrides:

getArea in class Geometry

Returns:

the area of the polygon

getLength

public double getLength()

Returns the perimeter of this Polygon

Overrides:

getLength in class Geometry

Returns:

the perimeter of the polygon

getBoundary

public Geometry getBoundary()

Computes the boundary of this geometry

Specified by:

getBoundary in class Geometry

Returns:

a lineal geometry (which may be empty)

See Also:

Geometry.getBoundary()

computeEnvelopeInternal

protected Envelope computeEnvelopeInternal()

Description copied from class: Geometry

Returns the minimum and maximum x and y values in this Geometry , or a null Envelope if this Geometry is empty. Unlike getEnvelopeInternal, this method calculates the Envelope each time it is called; getEnvelopeInternal caches the result of this method.

Specified by:

computeEnvelopeInternal in class Geometry

Returns:

this Geometrys bounding box; if the Geometry is empty, Envelope#isNull will return true

equalsExact

public boolean equalsExact(Geometry other,
                           double tolerance)

Description copied from class: Geometry

Returns true if the two Geometrys are exactly equal, up to a specified distance tolerance. Two Geometries are exactly equal within a distance tolerance if and only if:

• they have the same structure
• they have the same values for their vertices, within the given tolerance distance, in exactly the same order.

This method does not test the values of the GeometryFactory, the SRID, or the userData fields.

To properly test equality between different geometries, it is usually necessary to Geometry.normalize() them first.

Specified by:

equalsExact in class Geometry

Parameters:

other - the Geometry with which to compare this Geometry

tolerance - distance at or below which two Coordinates are considered equal

Returns:

true if this and the other Geometry have identical structure and point values, up to the distance tolerance.

See Also:

Geometry.equalsExact(Geometry), Geometry.normalize(), Geometry.norm()

apply

public void apply(CoordinateFilter filter)

Description copied from class: Geometry

Performs an operation with or on this Geometry's coordinates. If this method modifies any coordinate values, Geometry.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).

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry's coordinates

apply

public void apply(CoordinateSequenceFilter filter)

Description copied from class: Geometry

Performs an operation on the coordinates in this Geometry's CoordinateSequences. If the filter reports that a coordinate value has been changed, Geometry.geometryChanged() will be called automatically.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply

apply

public void apply(GeometryFilter filter)

Description copied from class: Geometry

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

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry (and its children, if it is a GeometryCollection).

apply

public void apply(GeometryComponentFilter filter)

Description copied from class: Geometry

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.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry.

clone

public java.lang.Object clone()

Creates and returns a full copy of this Polygon object. (including all coordinates contained by it).

Overrides:

clone in class Geometry

Returns:

a clone of this instance

convexHull

public Geometry convexHull()

Description copied from class: Geometry

Computes the smallest convex Polygon that contains all the points in the Geometry. This obviously applies only to Geometry s which contain 3 or more points; the results for degenerate cases are specified as follows:

Number of Points in argument Geometry	Geometry class of result
0	empty GeometryCollection
1	Point
2	LineString
3 or more	Polygon

Overrides:

convexHull in class Geometry

Returns:

the minimum-area convex polygon containing this Geometry' s points

normalize

public void normalize()

Description copied from class: Geometry

Converts this Geometry to normal form (or canonical form ). Normal form is a unique representation for Geometry s. It can be used to test whether two Geometrys are equal in a way that is independent of the ordering of the coordinates within them. Normal form equality is a stronger condition than topological equality, but weaker than pointwise equality. The definitions for normal form use the standard lexicographical ordering for coordinates. "Sorted in order of coordinates" means the obvious extension of this ordering to sequences of coordinates.

NOTE that this method mutates the value of this geometry in-place. If this is not safe and/or wanted, the geometry should be cloned prior to normalization.

Specified by:

normalize in class Geometry

compareToSameClass

protected int compareToSameClass(java.lang.Object o)

Description copied from class: Geometry

Returns whether this Geometry is greater than, equal to, or less than another Geometry having the same class.

Specified by:

compareToSameClass in class Geometry

Parameters:

o - a Geometry having the same class as this Geometry

Returns:

a positive number, 0, or a negative number, depending on whether this object is greater than, equal to, or less than o, as defined in "Normal Form For Geometry" in the JTS Technical Specifications

compareToSameClass

protected int compareToSameClass(java.lang.Object o,
                                 CoordinateSequenceComparator comp)

Description copied from class: Geometry

Returns whether this Geometry is greater than, equal to, or less than another Geometry of the same class. using the given CoordinateSequenceComparator.

Specified by:

compareToSameClass in class Geometry

Parameters:

o - a Geometry having the same class as this Geometry

comp - a CoordinateSequenceComparator

Returns:

a positive number, 0, or a negative number, depending on whether this object is greater than, equal to, or less than o, as defined in "Normal Form For Geometry" in the JTS Technical Specifications

reverse

public Geometry reverse()

Description copied from class: Geometry

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

Specified by:

reverse in class Geometry

Returns:

a reversed geometry