com.kheops.jmap.spatial

Class Polygon

java.lang.Object

com.kheops.jmap.spatial.DefaultGeometry

com.kheops.jmap.spatial.Polygon

All Implemented Interfaces:

Geometry, PolygonTypeGeometry, Surface, java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

OrientedRectangle

public class Polygon
extends DefaultGeometry
implements Surface, PolygonTypeGeometry

The Polygon class defines a polygon in a 2D space.
It is defined by a exterior ring and a set of non-intersecting rings called holes contained in the exterior ring.
A hole can intersect the exterior ring only on a single point.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected LinearRing[]	rings the rings defining the polygon.

Fields inherited from interface com.kheops.jmap.spatial.Geometry

GEOMETRY_ANNOTATION, GEOMETRY_COMPLEX, GEOMETRY_ELLIPSE, GEOMETRY_LINE, GEOMETRY_LINEAR_RING, GEOMETRY_LINESTRING, GEOMETRY_MULTI_ANNOTATION, GEOMETRY_MULTI_LINESTRING, GEOMETRY_MULTI_POINT, GEOMETRY_MULTI_POLYGON, GEOMETRY_POINT, GEOMETRY_POLYGON, GEOMETRY_RECTANGLE

Constructor Summary

Constructors

Constructor and Description
Polygon()
Polygon(double[][] tab) Constructs a Polygon given a matrix of double (rings made of points, points are entered as x y in the array), doesn't check if it's valid !
Polygon(LinearRing ring) Constructs a Polygon given a single ring, doesn't check if it's valid !
Polygon(LinearRing[] rings) Constructs a Polygon given rings, doesn't check if it's valid !

Method Summary

Modifier and Type	Method and Description
double	area() Computes the area of this Polygon
java.lang.String	asText() Returns this geometry encoded using the Well-Known Text (WKT) standard.
Geometry	boundary() The boundary (!= boundingBox) of this polygon
Point	centroid() Computes the centroid (center of mass) of the polygon, considering possibles holes in it.
Polygon	clone() Clones the current polygon object.
void	createBounds() creates the bounding box called in the constructor, not needed from outside
boolean	equals(java.lang.Object o)
LinearRing	exteriorRing() The Exterior Ring
Rectangle	getBounds() Returns the bounding box
Point	getCenteredPoint() This method returns a point that is typically centered on the geometry.
short	getGeometryId() Returns the geometry class id.
int	getGeometryType() Returns the geometry type for this geometry.
LinearRing[]	getRings() The rings defining this polygon
boolean	hasHoles()
LinearRing	interiorRingN(int N)
double	length() Returns the geometry length.
int	numInteriorRing() The number of holes
Point	pointOnSurface() a Point on this Polygon, in fact the first of the exteriorRing (not in the interior)
PolygonGeometryIterator	polygonIterator()
Point[]	serialize() This polygon as an array of Point
void	setRings(LinearRing[] rings)
int	sizeOf() Returns an approximation in bytes of the memory used by this geometry.
boolean	spatiallyEquals(Geometry geometry, PrecisionModel precisionModel) Tests if this Polygon is equal to the argument, on a topological point of vue it means that they represents the same geometry, even if it is described differently (direction of the rings, order of the rings) it does not remove additional points on lineString (3 points aligned), one must use smoother.removeExtraPoints() before in order to achieve that.
java.lang.String	toString() Returns informations about the current geometry.
Geometry	transform(Transformation tr) Creates a clone of the current polygon and returns the new instance transformed with the specified geometry transformation. The returned geometry can be of any geometry types after the transformation.
void	translate(double dx, double dy) Translate this Polygon
boolean	validate() validate this polygon ie test if it autointersects and if holes crosse the exteriorRing

Methods inherited from class com.kheops.jmap.spatial.DefaultGeometry

spatiallyEquals

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.kheops.jmap.spatial.Geometry

spatiallyEquals

Field Detail

rings

protected LinearRing[] rings

the rings defining the polygon. The first is the exterior Ring, others are the holes

Constructor Detail

Polygon

public Polygon()

Polygon

public Polygon(LinearRing ring)

Constructs a Polygon given a single ring, doesn't check if it's valid !

Parameters:

ring -

Polygon

public Polygon(LinearRing[] rings)

Constructs a Polygon given rings, doesn't check if it's valid !

Parameters:

rings -

Polygon

public Polygon(double[][] tab)

Constructs a Polygon given a matrix of double (rings made of points, points are entered as x y in the array), doesn't check if it's valid !

Parameters:

tab -

Method Detail

getBounds

public Rectangle getBounds()

Returns the bounding box

Specified by:

getBounds in interface Geometry

Returns:

the bounding box of this geometry.

validate

public boolean validate()

validate this polygon
ie test if it autointersects and if holes crosse the exteriorRing

Returns:

createBounds

public void createBounds()

creates the bounding box
called in the constructor, not needed from outside

Specified by:

createBounds in interface Geometry

centroid

public Point centroid()

Computes the centroid (center of mass) of the polygon, considering possibles holes in it.
it also computes Area, available with getTempArea if needed

Specified by:

centroid in interface PolygonTypeGeometry

Specified by:

centroid in interface Surface

Returns:

the center of mass

area

public double area()

Computes the area of this Polygon

Specified by:

area in interface Geometry

Specified by:

area in interface PolygonTypeGeometry

Specified by:

area in interface Surface

Returns:

the area of this polygon

length

public double length()

Description copied from interface: Geometry

Returns the geometry length. If the geometry is a surface, then the geometry perimeter shall be returned.

Specified by:

length in interface Geometry

Returns:

the geometry length.

clone

public Polygon clone()

Clones the current polygon object.

Specified by:

clone in interface Geometry

Specified by:

clone in class DefaultGeometry

Returns:

serialize

public Point[] serialize()

This polygon as an array of Point

Specified by:

serialize in interface Geometry

Returns:

this geometry as an array of Point.

exteriorRing

public LinearRing exteriorRing()

The Exterior Ring

Returns:

numInteriorRing

public int numInteriorRing()

The number of holes

Returns:

interiorRingN

public LinearRing interiorRingN(int N)

boundary

public Geometry boundary()

The boundary (!= boundingBox) of this polygon

Specified by:

boundary in interface Geometry

Returns:

a MultiLineString object describing the boundary of the polygon

pointOnSurface

public Point pointOnSurface()

a Point on this Polygon, in fact the first of the exteriorRing (not in the interior)

Specified by:

pointOnSurface in interface PolygonTypeGeometry

Specified by:

pointOnSurface in interface Surface

Returns:

a point on thge surface.

getRings

public LinearRing[] getRings()

The rings defining this polygon

Returns:

setRings

public void setRings(LinearRing[] rings)

Parameters:

rings -

hasHoles

public boolean hasHoles()

spatiallyEquals

public boolean spatiallyEquals(Geometry geometry,
                               PrecisionModel precisionModel)

Tests if this Polygon is equal to the argument, on a topological point of vue
it means that they represents the same geometry, even if it is described differently (direction of the rings, order of the rings)
it does not remove additional points on lineString (3 points aligned), one must use smoother.removeExtraPoints() before in order to achieve that.

Specified by:

spatiallyEquals in interface Geometry

Parameters:

geometry -

precisionModel - the precision model to use while comparing geometries.

Returns:

whether or not both geometries are spatially equals.

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Description copied from interface: Geometry

Returns informations about the current geometry.

Specified by:

toString in interface Geometry

Overrides:

toString in class java.lang.Object

Returns:

informations about the current geometry.

polygonIterator

public PolygonGeometryIterator polygonIterator()

Specified by:

polygonIterator in interface PolygonTypeGeometry

translate

public void translate(double dx,
                      double dy)

Translate this Polygon

Specified by:

translate in interface Geometry

Parameters:

dx - : translation on the X-axis

dy - : translation on the Y-axis

getGeometryId

public short getGeometryId()

Description copied from interface: Geometry

Returns the geometry class id. This method is useful for geometry serialization.

Specified by:

getGeometryId in interface Geometry

Returns:

the geometry id.

getGeometryType

public int getGeometryType()

Description copied from interface: Geometry

Returns the geometry type for this geometry.

Specified by:

getGeometryType in interface Geometry

Returns:

the geometry type.

See Also:

for more details.

transform

public Geometry transform(Transformation tr)

Creates a clone of the current polygon and returns the new instance transformed with the specified geometry transformation.
The returned geometry can be of any geometry types after the transformation.

Specified by:

transform in interface Geometry

Parameters:

tr - the transformation to apply.

Returns:

the newly created and transformed geometry instance.

getCenteredPoint

public Point getCenteredPoint()

Description copied from interface: Geometry

This method returns a point that is typically centered on the geometry. If the geometry is a point, the point is returned. If it is a line, a point on the curve interpolated at 50% is returned. If the geometry is a surface, the centroid is returned if it is inside the polygon, if not, a point inside the polygon (but likely not exactly in the center) will be returned. If the geometry is a collection, the method is called on the first part of the collection.

Specified by:

getCenteredPoint in interface Geometry

Returns:

a point likely at the center of the geometry

See Also:

Geometry.getCenteredPoint()

sizeOf

public int sizeOf()

Returns an approximation in bytes of the memory used by this geometry.

Specified by:

sizeOf in interface Geometry

Returns:

the memory used by this geometry.

asText

public java.lang.String asText()

Description copied from class: DefaultGeometry

Returns this geometry encoded using the Well-Known Text (WKT) standard.

Specified by:

asText in interface Geometry

Overrides:

asText in class DefaultGeometry

Returns:

a WKT geometry.