org.opengis.cite.geomatics

Class TopologicalRelationships

java.lang.Object

org.opengis.cite.geomatics.TopologicalRelationships

public class TopologicalRelationships
extends Object

Provides methods to test for the existence of a specified spatial relationship between two geometric objects.

See Also:

OpenGIS Implementation Specification for Geographic information - Simple feature access - Part 1: Common architecture

Constructor Summary

Constructors

Constructor and Description
TopologicalRelationships()

Method Summary

Modifier and Type	Method and Description
static boolean	isBeyond(Node g1, Node g2, Element distanceWithUom) Tests whether or not the orthodromic distance between two geometry objects is greater than or equal to the specified distance.
static boolean	isSpatiallyRelated(SpatialOperator predicate, Node node1, Node node2) Determines whether or not two GML geometry representations are spatially related in some manner (e.g.
static boolean	isWithinDistance(Node geom1, Node geom2, Element distanceWithUom) Tests whether or not the minimum (orthodromic) distance between two geometry objects is less than the specified distance.
(package private) static com.vividsolutions.jts.geom.Geometry	setCRS(com.vividsolutions.jts.geom.Geometry g1, CoordinateReferenceSystem crs) Checks that the given geometry object uses the specified CRS.
(package private) static com.vividsolutions.jts.geom.Geometry	toJTSGeometry(org.geotoolkit.gml.xml.AbstractGeometry gmlGeom) Builds a JTS geometry object from a GML geometry object.
(package private) static org.geotoolkit.gml.xml.AbstractGeometry	unmarshal(Node geomNode) Creates a GML geometry object from a DOM node.

Methods inherited from class java.lang.Object

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

Constructor Detail

TopologicalRelationships

public TopologicalRelationships()

Method Detail

isSpatiallyRelated

public static boolean isSpatiallyRelated(SpatialOperator predicate,
                                         Node node1,
                                         Node node2)

Determines whether or not two GML geometry representations are spatially related in some manner (e.g. g1 contains g2). If the geometry representations have different CRS references, an attempt will be made to change coordinates from one CRS to another through the application of a coordinate operation (conversion or transformation).

Parameters:

predicate - A spatial relationship (predicate).

node1 - An Element node representing a GML geometry object.

node2 - An Element node representing another GML geometry object.

Returns:

true if the geometries satisfy the given spatial relationship ; false otherwise.

isWithinDistance

public static boolean isWithinDistance(Node geom1,
                                       Node geom2,
                                       Element distanceWithUom)

Tests whether or not the minimum (orthodromic) distance between two geometry objects is less than the specified distance. That is,

 DWithin(A,B,d) ⇔ Distance(A,B) < d
 

The computed distance is the shortest distance between the two nearest points in the geometry instances, as measured along the surface of an ellipsoid.

The unit of measure identifier for the given distance must be either a standard symbol for a unit of length (from UCUM) or an absolute URI that refers to a unit definition (unsupported). SI prefix symbols may also be used (see examples in the table below).

Units of Length (UCUM)

Symbol (c/s)	Name
m	metre
km	kilometre
[mi_i]	international mile
[nmi_i]	international nautical mile

Parameters:

geom1 - An Element node representing a GML geometry instance.

geom2 - An Element node representing some other GML geometry instance.

distanceWithUom - An fes:Distance element with a unit of measurement.

Returns:

true if the minimum distance between the geometries is less than the given quantity; false otherwise.

See Also:

The Unified Code for Units of Measure (UCUM)

isBeyond

public static boolean isBeyond(Node g1,
                               Node g2,
                               Element distanceWithUom)

Tests whether or not the orthodromic distance between two geometry objects is greater than or equal to the specified distance. That is,

 Beyond(A,B,d) ⇔ Distance(A,B) >= d
 

Parameters:

g1 - An Element node representing a GML geometry instance.

g2 - An Element node representing some other GML geometry instance.

distanceWithUom - An fes:Distance element with a unit of measurement.

Returns:

true if the minimum distance between the geometries equals or exceeds the given quantity; false otherwise.

toJTSGeometry

static com.vividsolutions.jts.geom.Geometry toJTSGeometry(org.geotoolkit.gml.xml.AbstractGeometry gmlGeom)

Builds a JTS geometry object from a GML geometry object.

Parameters:

gmlGeom - A GML geometry.

Returns:

A JTS geometry, or null if one could not be constructed.

unmarshal

static org.geotoolkit.gml.xml.AbstractGeometry unmarshal(Node geomNode)

Creates a GML geometry object from a DOM node.

Parameters:

geomNode - A node representing a GML geometry instance.

Returns:

A geometry object.

setCRS

static com.vividsolutions.jts.geom.Geometry setCRS(com.vividsolutions.jts.geom.Geometry g1,
                                                   CoordinateReferenceSystem crs)
                                            throws FactoryException,
                                                   TransformException

Checks that the given geometry object uses the specified CRS. If this is not the case, an attempt is made to change it.

Parameters:

g1 - A JTS geometry object.

crs - The target CRS.

Returns:

A Geometry object that uses the indicated CRS (the original geometry if its CRS was unchanged).

Throws:

FactoryException - If a CRS cannot be identified (e.g. a missing or invalid reference).

TransformException - If any coordinate operation (conversion or transformation) fails.