com.franz.ag
Class Polygon

java.lang.Object
  com.franz.ag.Polygon

public class Polygon

extends java.lang.Object

This class is used to represent a collection of point coordinates that form a polygon in 2-dimensional space.

A Polygon is represented in a triple store as a collection of triples, all with the same subject. The predicates are generated by the implementation and identify the point coordinates. The objects of the triples are encoded vertex coordinates.

Constructor Summary

Polygon(int vertices)
Create an empty Polygon instance with room for a given number of vertices.

Method Summary

UPI	add(AllegroGraph ag) Add the polygon to a triple store.
void	addVertex(double x, double y) Add one pair of vertex coordinates to the Polygon.
void	get(AllegroGraph ag) Retrieve the coordinates of this polygon from the triple store.
boolean	getModified() Query the state of a Polygon instance.
double[]	getPoints() Get the array of coordinates for the points in the Polygon.
UPI	getSubject() Query the subject that identifies the triples in a polygon.
GeospatialSubtype	getSubtype() Get the GeospatialSubtype associated with all the points in the Polygon instance.
boolean	pointInside(double x, double y) Query whether a point is inside a polygon.
boolean[]	pointsInside(double[] xy) Query whether some points are inside a polygon.
boolean[]	pointsInside(double[] x, double[] y) Query whether some points are inside a polygon.
void	setSubject(UPI subject) Set the subject that identifies the triples in a polygon.
void	setSubtype(GeospatialSubtype subtype) Set the GeospatialSubtype associated with all the points in the Polygon instance.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Polygon

public Polygon(int vertices)

Create an empty Polygon instance with room for a given number of vertices.

Parameters:

vertices - the number of vertices in the Polygon.

Method Detail

getSubtype

public GeospatialSubtype getSubtype()

Get the GeospatialSubtype associated with all the points in the Polygon instance.

Returns:

the GeospatialSubtype

setSubtype

public void setSubtype(GeospatialSubtype subtype)

Set the GeospatialSubtype associated with all the points in the Polygon instance.

Parameters:

subtype - the GeospatialSubtype

getPoints

public double[] getPoints()

Get the array of coordinates for the points in the Polygon.

Returns:

an array of alternating x and y coordinates

getModified

public boolean getModified()

Query the state of a Polygon instance.

Returns:

true if the Polygon contains changes not transmitted to the server.

getSubject

public UPI getSubject()

Query the subject that identifies the triples in a polygon.

Returns:

the subject

setSubject

public void setSubject(UPI subject)

Set the subject that identifies the triples in a polygon. If the subject is null, a new blank node will be assigned to the Polugon when it is added to a triple store.

Parameters:

subject - the subject to set

addVertex

public void addVertex(double x,
                      double y)

Add one pair of vertex coordinates to the Polygon.

Parameters:

x -

y -

add

public UPI add(AllegroGraph ag)
        throws AllegroGraphException

Add the polygon to a triple store.

Parameters:

ag - The triple store.

Returns:

the UPI that identifies the triples in the polygon.

Throws:

AllegroGraphException

get

public void get(AllegroGraph ag)
         throws AllegroGraphException

Retrieve the coordinates of this polygon from the triple store.

Parameters:

ag - the triple store

Throws:

AllegroGraphException

pointInside

public boolean pointInside(double x,
                           double y)
                    throws AllegroGraphException

Query whether a point is inside a polygon.

Parameters:

x -

y -

Returns:

true if the point is inside

Throws:

AllegroGraphException

pointsInside

public boolean[] pointsInside(double[] xy)
                       throws AllegroGraphException

Query whether some points are inside a polygon.

Parameters:

xy - An array of alternating x and y coordinates

Returns:

an array of boolean values. The length of the array is half the length of the xy array. Each boolean value is true or false if the corresponding point is inside or outside the Polygon.

Throws:

AllegroGraphException

pointsInside

public boolean[] pointsInside(double[] x,
                              double[] y)
                       throws AllegroGraphException

Query whether some points are inside a polygon.

Parameters:

x - An array of x coordinates

y - An array of y coordinates The two arrays must of the same length.

Returns:

an array of boolean values. The length of the array is equal to the length of the argument array. Each boolean value is true or false if the corresponding point is inside or outside the Polygon.

Throws:

AllegroGraphException