/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.vividsolutions.jts.geom;
import java.io.Serializable;
import java.util.*;
import com.vividsolutions.jts.algorithm.*;
import com.vividsolutions.jts.geom.util.*;
import com.vividsolutions.jts.io.WKTWriter;
import com.vividsolutions.jts.operation.*;
import com.vividsolutions.jts.operation.buffer.BufferOp;
import com.vividsolutions.jts.operation.distance.DistanceOp;
import com.vividsolutions.jts.operation.overlay.OverlayOp;
import com.vividsolutions.jts.operation.union.UnaryUnionOp;
import com.vividsolutions.jts.operation.overlay.snap.SnapIfNeededOverlayOp;
import com.vividsolutions.jts.operation.predicate.RectangleIntersects;
import com.vividsolutions.jts.operation.predicate.RectangleContains;
import com.vividsolutions.jts.operation.relate.RelateOp;
import com.vividsolutions.jts.operation.valid.IsValidOp;
import com.vividsolutions.jts.util.Assert;
/**
* The base class for all geometric objects.
* <P>
*
* <H3>Binary Predicates</H3>
* Because it is not clear at this time
* what semantics for spatial
* analysis methods involving <code>GeometryCollection</code>s would be useful,
* <code>GeometryCollection</code>s are not supported as arguments to binary
* predicates (other than <code>convexHull</code>) or the <code>relate</code>
* method.
*
* <H3>Set-Theoretic Methods</H3>
*
* The spatial analysis methods will
* return the most specific class possible to represent the result. If the
* result is homogeneous, a <code>Point</code>, <code>LineString</code>, or
* <code>Polygon</code> will be returned if the result contains a single
* element; otherwise, a <code>MultiPoint</code>, <code>MultiLineString</code>,
* or <code>MultiPolygon</code> will be returned. If the result is
* heterogeneous a <code>GeometryCollection</code> will be returned. <P>
*
* Because it is not clear at this time what semantics for set-theoretic
* methods involving <code>GeometryCollection</code>s would be useful,
* <code>GeometryCollections</code>
* are not supported as arguments to the set-theoretic methods.
*
* <H4>Representation of Computed Geometries </H4>
*
* The SFS states that the result
* of a set-theoretic method is the "point-set" result of the usual
* set-theoretic definition of the operation (SFS 3.2.21.1). However, there are
* sometimes many ways of representing a point set as a <code>Geometry</code>.
* <P>
*
* The SFS does not specify an unambiguous representation of a given point set
* returned from a spatial analysis method. One goal of JTS is to make this
* specification precise and unambiguous. JTS will use a canonical form for
* <code>Geometry</code>s returned from spatial analysis methods. The canonical
* form is a <code>Geometry</code> which is simple and noded:
* <UL>
* <LI> Simple means that the Geometry returned will be simple according to
* the JTS definition of <code>isSimple</code>.
* <LI> Noded applies only to overlays involving <code>LineString</code>s. It
* means that all intersection points on <code>LineString</code>s will be
* present as endpoints of <code>LineString</code>s in the result.
* </UL>
* This definition implies that non-simple geometries which are arguments to
* spatial analysis methods must be subjected to a line-dissolve process to
* ensure that the results are simple.
*
* <H4> Constructed Points And The Precision Model </H4>
*
* The results computed by the set-theoretic methods may
* contain constructed points which are not present in the input <code>Geometry</code>
* s. These new points arise from intersections between line segments in the
* edges of the input <code>Geometry</code>s. In the general case it is not
* possible to represent constructed points exactly. This is due to the fact
* that the coordinates of an intersection point may contain twice as many bits
* of precision as the coordinates of the input line segments. In order to
* represent these constructed points explicitly, JTS must truncate them to fit
* the <code>PrecisionModel</code>. <P>
*
* Unfortunately, truncating coordinates moves them slightly. Line segments
* which would not be coincident in the exact result may become coincident in
* the truncated representation. This in turn leads to "topology collapses" --
* situations where a computed element has a lower dimension than it would in
* the exact result. <P>
*
* When JTS detects topology collapses during the computation of spatial
* analysis methods, it will throw an exception. If possible the exception will
* report the location of the collapse. <P>
*
* #equals(Object) and #hashCode are not overridden, so that when two
* topologically equal Geometries are added to HashMaps and HashSets, they
* remain distinct. This behaviour is desired in many cases.
*
*@version 1.7
*/
public abstract class Geometry
implements Cloneable, Comparable, Serializable
{
private static final long serialVersionUID = 8763622679187376702L;
private static Class[] sortedClasses;
private final static GeometryComponentFilter geometryChangedFilter = new GeometryComponentFilter() {
public void filter(Geometry geom) {
geom.geometryChangedAction();
}
};
/**
* The bounding box of this <code>Geometry</code>.
*/
protected Envelope envelope;
/**
* The {@link GeometryFactory} used to create this Geometry
*/
protected final GeometryFactory factory;
/**
* The ID of the Spatial Reference System used by this <code>Geometry</code>
*/
protected int SRID;
/**
* An object reference which can be used to carry ancillary data defined
* by the client.
*/
private Object userData = null;
/**
* Creates a new <tt>Geometry</tt> via the specified GeometryFactory.
*
* @param factory
*/
public Geometry(GeometryFactory factory) {
this.factory = factory;
this.SRID = factory.getSRID();
}
/**
* Returns the name of this object's <code>com.vivid.jts.geom</code>
* interface.
*
*@return the name of this <code>Geometry</code>s most specific <code>com.vividsolutions.jts.geom</code>
* interface
*/
public abstract String getGeometryType();
/**
* Returns true if the array contains any non-empty <code>Geometry</code>s.
*
*@param geometries an array of <code>Geometry</code>s; no elements may be
* <code>null</code>
*@return <code>true</code> if any of the <code>Geometry</code>s
* <code>isEmpty</code> methods return <code>false</code>
*/
protected static boolean hasNonEmptyElements(Geometry[] geometries) {
for (int i = 0; i < geometries.length; i++) {
if (!geometries[i].isEmpty()) {
return true;
}
}
return false;
}
/**
* Returns true if the array contains any <code>null</code> elements.
*
*@param array an array to validate
*@return <code>true</code> if any of <code>array</code>s elements are
* <code>null</code>
*/
protected static boolean hasNullElements(Object[] array) {
for (int i = 0; i < array.length; i++) {
if (array[i] == null) {
return true;
}
}
return false;
}
/**
* Returns the ID of the Spatial Reference System used by the <code>Geometry</code>.
* <P>
*
* JTS supports Spatial Reference System information in the simple way
* defined in the SFS. A Spatial Reference System ID (SRID) is present in
* each <code>Geometry</code> object. <code>Geometry</code> provides basic
* accessor operations for this field, but no others. The SRID is represented
* as an integer.
*
*@return the ID of the coordinate space in which the <code>Geometry</code>
* is defined.
*
*/
public int getSRID() {
return SRID;
}
/**
* Sets the ID of the Spatial Reference System used by the <code>Geometry</code>.
* <p>
* <b>NOTE:</b> This method should only be used for exceptional circumstances or
* for backwards compatibility. Normally the SRID should be set on the
* {@link GeometryFactory} used to create the geometry.
* SRIDs set using this method will <i>not</i> be propagated to
* geometries returned by constructive methods.
*
* @see GeometryFactory
*/
public void setSRID(int SRID) {
this.SRID = SRID;
}
/**
* Gets the factory which contains the context in which this geometry was created.
*
* @return the factory for this geometry
*/
public GeometryFactory getFactory() {
return factory;
}
/**
* Gets the user data object for this geometry, if any.
*
* @return the user data object, or <code>null</code> if none set
*/
public Object getUserData() {
return userData;
}
/**
* Returns the number of {@link Geometry}s in a {@link GeometryCollection}
* (or 1, if the geometry is not a collection).
*
* @return the number of geometries contained in this geometry
*/
public int getNumGeometries() {
return 1;
}
/**
* Returns an element {@link Geometry} from a {@link GeometryCollection}
* (or <code>this</code>, if the geometry is not a collection).
*
* @param n the index of the geometry element
* @return the n'th geometry contained in this geometry
*/
public Geometry getGeometryN(int n) {
return this;
}
/**
* A simple scheme for applications to add their own custom data to a Geometry.
* An example use might be to add an object representing a Coordinate Reference System.
* <p>
* Note that user data objects are not present in geometries created by
* construction methods.
*
* @param userData an object, the semantics for which are defined by the
* application using this Geometry
*/
public void setUserData(Object userData) {
this.userData = userData;
}
/**
* Returns the <code>PrecisionModel</code> used by the <code>Geometry</code>.
*
*@return the specification of the grid of allowable points, for this
* <code>Geometry</code> and all other <code>Geometry</code>s
*/
public PrecisionModel getPrecisionModel() {
return factory.getPrecisionModel();
}
/**
* Returns a vertex of this <code>Geometry</code>
* (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.
*
*@return a {@link Coordinate} which is a vertex of this <code>Geometry</code>.
*@return null if this Geometry is empty
*/
public abstract Coordinate getCoordinate();
/**
* 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.
* <p>
* 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 {@link CoordinateSequence#setOrdinate} method
* (possibly on the components) to modify the underlying data.
* If the coordinates are modified,
* {@link #geometryChanged} must be called afterwards.
*
*@return the vertices of this <code>Geometry</code>
*@see geometryChanged
*@see CoordinateSequence#setOrdinate
*/
public abstract Coordinate[] getCoordinates();
/**
* Returns the count of this <code>Geometry</code>s vertices. The <code>Geometry</code>
* s contained by composite <code>Geometry</code>s must be
* Geometry's; that is, they must implement <code>getNumPoints</code>
*
*@return the number of vertices in this <code>Geometry</code>
*/
public abstract int getNumPoints();
/**
* Tests whether this {@link Geometry} is simple.
* In general, the SFS specification of simplicity
* follows the rule:
* <UL>
* <LI> A Geometry is simple iff the only self-intersections are at
* boundary points.
* </UL>
* Simplicity is defined for each {@link Geometry} subclass as follows:
* <ul>
* <li>Valid polygonal geometries are simple by definition, so
* <code>isSimple</code> trivially returns true.
* <li>Linear geometries are simple iff they do not self-intersect at points
* other than boundary points.
* <li>Zero-dimensional geometries (points) are simple iff they have no
* repeated points.
* <li>Empty <code>Geometry</code>s are always simple
* <ul>
*
* @return <code>true</code> if this <code>Geometry</code> has any points of
* self-tangency, self-intersection or other anomalous points
* @see #isValid
*/
public boolean isSimple()
{
checkNotGeometryCollection(this);
IsSimpleOp op = new IsSimpleOp(this);
return op.isSimple();
}
/**
* Tests the validity of this <code>Geometry</code>.
* Subclasses provide their own definition of "valid".
*
*@return <code>true</code> if this <code>Geometry</code> is valid
*
* @see IsValidOp
*/
public boolean isValid()
{
IsValidOp isValidOp = new IsValidOp(this);
return isValidOp.isValid();
}
/**
* Returns whether or not the set of points in this <code>Geometry</code> is
* empty.
*
*@return <code>true</code> if this <code>Geometry</code> equals the empty
* geometry
*/
public abstract boolean isEmpty();
/**
* Returns the minimum distance between this <code>Geometry</code>
* and the <code>Geometry</code> g
*
* @param g the <code>Geometry</code> from which to compute the distance
* @return the distance between the geometries
* @return 0 if either input geometry is empty
* @throws IllegalArgumentException if g is null
*/
public double distance(Geometry g)
{
return DistanceOp.distance(this, g);
}
/**
* Tests whether the distance from this <code>Geometry</code>
* to another is less than or equal to a specified value.
*
* @param geom the Geometry to check the distance to
* @param distance the distance value to compare
* @return <code>true</code> if the geometries are less than <code>distance</code> apart.
*/
public boolean isWithinDistance(Geometry geom, double distance)
{
double envDist = getEnvelopeInternal().distance(geom.getEnvelopeInternal());
if (envDist > distance)
return false;
return DistanceOp.isWithinDistance(this, geom, distance);
/*
double geomDist = this.distance(geom);
if (geomDist > distance)
return false;
return true;
*/
}
public boolean isRectangle()
{
// Polygon overrides to check for actual rectangle
return false;
}
/**
* Returns the area of this <code>Geometry</code>.
* Areal Geometries have a non-zero area.
* They override this function to compute the area.
* Others return 0.0
*
*@return the area of the Geometry
*/
public double getArea()
{
return 0.0;
}
/**
* Returns the length of this <code>Geometry</code>.
* Linear geometries return their length.
* Areal geometries return their perimeter.
* They override this function to compute the area.
* Others return 0.0
*
*@return the length of the Geometry
*/
public double getLength()
{
return 0.0;
}
/**
* Computes the centroid of this <code>Geometry</code>.
* The centroid
* is equal to the centroid of the set of component Geometries of highest
* dimension (since the lower-dimension geometries contribute zero
* "weight" to the centroid)
*
* @return a {@link Point} which is the centroid of this Geometry
*/
public Point getCentroid()
{
if (isEmpty()) { return null; }
Coordinate centPt = null;
int dim = getDimension();
if (dim == 0) {
CentroidPoint cent = new CentroidPoint();
cent.add(this);
centPt = cent.getCentroid();
}
else if (dim == 1) {
CentroidLine cent = new CentroidLine();
cent.add(this);
centPt = cent.getCentroid();
}
else {
CentroidArea cent = new CentroidArea();
cent.add(this);
centPt = cent.getCentroid();
}
return createPointFromInternalCoord(centPt, this);
}
/**
* Computes an interior point of this <code>Geometry</code>.
* An interior point is guaranteed to lie in the interior of the Geometry,
* if it possible to calculate such a point exactly. Otherwise,
* the point may lie on the boundary of the geometry.
*
* @return a {@link Point} which is in the interior of this Geometry
*/
public Point getInteriorPoint()
{
Coordinate interiorPt = null;
int dim = getDimension();
if (dim == 0) {
InteriorPointPoint intPt = new InteriorPointPoint(this);
interiorPt = intPt.getInteriorPoint();
}
else if (dim == 1) {
InteriorPointLine intPt = new InteriorPointLine(this);
interiorPt = intPt.getInteriorPoint();
}
else {
InteriorPointArea intPt = new InteriorPointArea(this);
interiorPt = intPt.getInteriorPoint();
}
return createPointFromInternalCoord(interiorPt, this);
}
/**
* 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}.
* <p>
* Note that this is a different concept to the dimension of
* the vertex {@link Coordinate}s.
* 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).
*
*@return the topological dimension of this geometry.
*/
public abstract int getDimension();
/**
* Returns the boundary, or an empty geometry of appropriate dimension
* if this <code>Geometry</code> is empty.
* (In the case of zero-dimensional geometries, '
* an empty GeometryCollection is returned.)
* For a discussion of this function, see the OpenGIS Simple
* Features Specification. As stated in SFS Section 2.1.13.1, "the boundary
* of a Geometry is a set of Geometries of the next lower dimension."
*
*@return the closure of the combinatorial boundary of this <code>Geometry</code>
*/
public abstract Geometry getBoundary();
/**
* Returns the dimension of this <code>Geometry</code>s inherent boundary.
*
*@return the dimension of the boundary of the class implementing this
* interface, whether or not this object is the empty geometry. Returns
* <code>Dimension.FALSE</code> if the boundary is the empty geometry.
*/
public abstract int getBoundaryDimension();
/**
* Returns this <code>Geometry</code>s bounding box. If this <code>Geometry</code>
* is the empty geometry, returns an empty <code>Point</code>. If the <code>Geometry</code>
* is a point, returns a non-empty <code>Point</code>. Otherwise, returns a
* <code>Polygon</code> whose points are (minx, miny), (maxx, miny), (maxx,
* maxy), (minx, maxy), (minx, miny).
*
*@return an empty <code>Point</code> (for empty <code>Geometry</code>s), a
* <code>Point</code> (for <code>Point</code>s) or a <code>Polygon</code>
* (in all other cases)
*/
public Geometry getEnvelope() {
return getFactory().toGeometry(getEnvelopeInternal());
}
/**
* Returns the minimum and maximum x and y values in this <code>Geometry</code>
* , or a null <code>Envelope</code> if this <code>Geometry</code> is empty.
*
*@return this <code>Geometry</code>s bounding box; if the <code>Geometry</code>
* is empty, <code>Envelope#isNull</code> will return <code>true</code>
*/
public Envelope getEnvelopeInternal() {
if (envelope == null) {
envelope = computeEnvelopeInternal();
}
return envelope;
}
/**
* Notifies this geometry that its coordinates have been changed by an external
* party (for example, via a {@link CoordinateFilter}).
* When this method is called the geometry will flush
* and/or update any derived information it has cached (such as its {@link Envelope} ).
*/
public void geometryChanged() {
apply(geometryChangedFilter);
}
/**
* Notifies this Geometry that its Coordinates have been changed by an external
* party. When #geometryChanged is called, this method will be called for
* this Geometry and its component Geometries.
* @see #apply(GeometryComponentFilter)
*/
protected void geometryChangedAction() {
envelope = null;
}
/**
* Tests whether this geometry is disjoint from the specified geometry.
* <p>
* The <code>disjoint</code> predicate has the following equivalent definitions:
* <ul>
* <li>The two geometries have no point in common
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[FF*FF****]</code>
* <li><code>! g.intersects(this)</code>
* (<code>disjoint</code> is the inverse of <code>intersects</code>)
* </ul>
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if the two <code>Geometry</code>s are
* disjoint
*
* @see Geometry#intersects
*/
public boolean disjoint(Geometry g) {
return ! intersects(g);
}
/**
* Tests whether this geometry touches the
* specified geometry.
* <p>
* The <code>touches</code> predicate has the following equivalent definitions:
* <ul>
* <li>The geometries have at least one point in common, but their interiors do not intersect.
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[FT*******]</code> or <code>[F**T*****]</code> or <code>[F***T****]</code>
* </ul>
* If both geometries have dimension 0, this predicate returns <code>false</code>
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if the two <code>Geometry</code>s touch;
* Returns <code>false</code> if both <code>Geometry</code>s are points
*/
public boolean touches(Geometry g) {
// short-circuit test
if (! getEnvelopeInternal().intersects(g.getEnvelopeInternal()))
return false;
return relate(g).isTouches(getDimension(), g.getDimension());
}
/**
* Tests whether this geometry intersects the specified geometry.
* <p>
* The <code>intersects</code> predicate has the following equivalent definitions:
* <ul>
* <li>The two geometries have at least one point in common
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[T********]</code>
* or <code>[*T*******]</code>
* or <code>[***T*****]</code>
* or <code>[****T****]</code>
* <li><code>! g.disjoint(this)</code>
* (<code>intersects</code> is the inverse of <code>disjoint</code>)
* </ul>
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if the two <code>Geometry</code>s intersect
*
* @see Geometry#disjoint
*/
public boolean intersects(Geometry g) {
// short-circuit envelope test
if (! getEnvelopeInternal().intersects(g.getEnvelopeInternal()))
return false;
/**
* TODO: (MD) Add optimizations:
*
* - for P-A case:
* If P is in env(A), test for point-in-poly
*
* - for A-A case:
* If env(A1).overlaps(env(A2))
* test for overlaps via point-in-poly first (both ways)
* Possibly optimize selection of point to test by finding point of A1
* closest to centre of env(A2).
* (Is there a test where we shouldn't bother - e.g. if env A
* is much smaller than env B, maybe there's no point in testing
* pt(B) in env(A)?
*/
// optimization for rectangle arguments
if (isRectangle()) {
return RectangleIntersects.intersects((Polygon) this, g);
}
if (g.isRectangle()) {
return RectangleIntersects.intersects((Polygon) g, this);
}
// general case
return relate(g).isIntersects();
}
/**
* Tests whether this geometry crosses the
* specified geometry.
* <p>
* The <code>crosses</code> predicate has the following equivalent definitions:
* <ul>
* <li>The geometries have some but not all interior points in common.
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <ul>
* <li><code>[T*T******]</code> (for P/L, P/A, and L/A situations)
* <li><code>[T*****T**]</code> (for L/P, A/P, and A/L situations)
* <li><code>[0********]</code> (for L/L situations)
* </ul>
* </ul>
* For any other combination of dimensions this predicate returns <code>false</code>.
* <p>
* The SFS defined this predicate only for P/L, P/A, L/L, and L/A situations.
* JTS extends the definition to apply to L/P, A/P and A/L situations as well,
* in order to make the relation symmetric.
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if the two <code>Geometry</code>s cross.
*/
public boolean crosses(Geometry g) {
// short-circuit test
if (! getEnvelopeInternal().intersects(g.getEnvelopeInternal()))
return false;
return relate(g).isCrosses(getDimension(), g.getDimension());
}
/**
* Tests whether this geometry is within the
* specified geometry.
* <p>
* The <code>within</code> predicate has the following equivalent definitions:
* <ul>
* <li>Every point of this geometry is a point of the other geometry,
* and the interiors of the two geometries have at least one point in common.
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[T*F**F***]</code>
* <li><code>g.contains(this)</code>
* (<code>within</code> is the converse of <code>contains</code>)
* </ul>
* An implication of the definition is that
* "The boundary of a Geometry is not within the Geometry".
* In other words, if a geometry A is a subset of
* the points in the boundary of a geomtry B, <code>A.within(B) = false</code>
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if this <code>Geometry</code> is within
* <code>other</code>
*
* @see Geometry#contains
*/
public boolean within(Geometry g) {
return g.contains(this);
}
/**
* Tests whether this geometry contains the
* specified geometry.
* <p>
* The <code>contains</code> predicate has the following equivalent definitions:
* <ul>
* <li>Every point of the other geometry is a point of this geometry,
* and the interiors of the two geometries have at least one point in common.
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[T*****FF*]</code>
* <li><code>g.within(this)</code>
* (<code>contains</code> is the converse of <code>within</code>)
* </ul>
* An implication of the definition is that "Geometries do not
* contain their boundary". In other words, if a geometry A is a subset of
* the points in the boundary of a geometry B, <code>B.contains(A) = false</code>
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if this <code>Geometry</code> contains <code>g</code>
*
* @see Geometry#within
*/
public boolean contains(Geometry g) {
// short-circuit test
if (! getEnvelopeInternal().contains(g.getEnvelopeInternal()))
return false;
// optimization for rectangle arguments
if (isRectangle()) {
return RectangleContains.contains((Polygon) this, g);
}
// general case
return relate(g).isContains();
}
/**
* Tests whether this geometry overlaps the
* specified geometry.
* <p>
* The <code>overlaps</code> predicate has the following equivalent definitions:
* <ul>
* <li>The geometries have at least one point each not shared by the other
* (or equivalently neither covers the other),
* they have the same dimension,
* and the intersection of the interiors of the two geometries has
* the same dimension as the geometries themselves.
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[T*T***T**]</code> (for two points or two surfaces)
* or <code>[1*T***T**]</code> (for two curves)
* </ul>
* If the geometries are of different dimension this predicate returns <code>false</code>.
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if the two <code>Geometry</code>s overlap.
*/
public boolean overlaps(Geometry g) {
// short-circuit test
if (! getEnvelopeInternal().intersects(g.getEnvelopeInternal()))
return false;
return relate(g).isOverlaps(getDimension(), g.getDimension());
}
/**
* Tests whether this geometry covers the
* specified geometry.
* <p>
* The <code>covers</code> predicate has the following equivalent definitions:
* <ul>
* <li>Every point of the other geometry is a point of this geometry.
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[T*****FF*]</code>
* or <code>[*T****FF*]</code>
* or <code>[***T**FF*]</code>
* or <code>[****T*FF*]</code>
* <li><code>g.coveredBy(this)</code>
* (<code>covers</code> is the converse of <code>coveredBy</code>)
* </ul>
* If either geometry is empty, the value of this predicate is <tt>false</tt>.
* <p>
* This predicate is similar to {@link #contains},
* but is more inclusive (i.e. returns <tt>true</tt> for more cases).
* In particular, unlike <code>contains</code> it does not distinguish between
* points in the boundary and in the interior of geometries.
* For most situations, <code>covers</code> should be used in preference to <code>contains</code>.
* As an added benefit, <code>covers</code> is more amenable to optimization,
* and hence should be more performant.
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if this <code>Geometry</code> covers <code>g</code>
*
* @see Geometry#contains
* @see Geometry#coveredBy
*/
public boolean covers(Geometry g) {
// short-circuit test
if (! getEnvelopeInternal().covers(g.getEnvelopeInternal()))
return false;
// optimization for rectangle arguments
if (isRectangle()) {
// since we have already tested that the test envelope is covered
return true;
}
return relate(g).isCovers();
}
/**
* Tests whether this geometry is covered by the
* specified geometry.
* <p>
* The <code>coveredBy</code> predicate has the following equivalent definitions:
* <ul>
* <li>Every point of this geometry is a point of the other geometry.
* <li>The DE-9IM Intersection Matrix for the two geometries matches
* <code>[T*F**F***]</code>
* or <code>[*TF**F***]</code>
* or <code>[**FT*F***]</code>
* or <code>[**F*TF***]</code>
* <li><code>g.covers(this)</code>
* (<code>coveredBy</code> is the converse of <code>covers</code>)
* </ul>
* If either geometry is empty, the value of this predicate is <tt>false</tt>.
* <p>
* This predicate is similar to {@link #within},
* but is more inclusive (i.e. returns <tt>true</tt> for more cases).
*
*@param g the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if this <code>Geometry</code> is covered by <code>g</code>
*
* @see Geometry#within
* @see Geometry#covers
*/
public boolean coveredBy(Geometry g) {
return g.covers(this);
}
/**
* Tests whether the elements in the DE-9IM
* {@link IntersectionMatrix} for the two <code>Geometry</code>s match the elements in <code>intersectionPattern</code>.
* The pattern is a 9-character string, with symbols drawn from the following set:
* <UL>
* <LI> 0 (dimension 0)
* <LI> 1 (dimension 1)
* <LI> 2 (dimension 2)
* <LI> T ( matches 0, 1 or 2)
* <LI> F ( matches FALSE)
* <LI> * ( matches any value)
* </UL>
* For more information on the DE-9IM, see the <i>OpenGIS Simple Features
* Specification</i>.
*
*@param other the <code>Geometry</code> with which to compare
* this <code>Geometry</code>
*@param intersectionPattern the pattern against which to check the
* intersection matrix for the two <code>Geometry</code>s
*@return <code>true</code> if the DE-9IM intersection
* matrix for the two <code>Geometry</code>s match <code>intersectionPattern</code>
* @see IntersectionMatrix
*/
public boolean relate(Geometry g, String intersectionPattern) {
return relate(g).matches(intersectionPattern);
}
/**
* Returns the DE-9IM {@link IntersectionMatrix} for the two <code>Geometry</code>s.
*
*@param other the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return an {@link IntersectionMatrix} describing the intersections of the interiors,
* boundaries and exteriors of the two <code>Geometry</code>s
*/
public IntersectionMatrix relate(Geometry g) {
checkNotGeometryCollection(this);
checkNotGeometryCollection(g);
return RelateOp.relate(this, g);
}
/**
* Tests whether this geometry is equal to the
* specified geometry.
* <p>
* The <code>equals</code> predicate has the following equivalent definitions:
* <ul>
* <li>The two geometries have at least one point in common,
* and no point of either geometry lies in the exterior of the other geometry.
* <li>The DE-9IM Intersection Matrix for the two geometries is T*F**FFF*
* </ul>
* <b>Note</b> that this method computes topologically equality, not structural or
* vertex-wise equality.
*
*@param other the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if the two <code>Geometry</code>s are equal
*/
public boolean equals(Geometry g) {
// short-circuit test
if (! getEnvelopeInternal().equals(g.getEnvelopeInternal()))
return false;
return relate(g).isEquals(getDimension(), g.getDimension());
}
public String toString() {
return toText();
}
/**
* Returns the Well-known Text representation of this <code>Geometry</code>.
* For a definition of the Well-known Text format, see the OpenGIS Simple
* Features Specification.
*
*@return the Well-known Text representation of this <code>Geometry</code>
*/
public String toText() {
WKTWriter writer = new WKTWriter();
return writer.write(this);
}
/**
* Computes a buffer area around this geometry having the given width. The
* buffer of a Geometry is the Minkowski sum or difference of the geometry
* with a disc of radius <code>abs(distance)</code>.
* <p>
* Mathematically-exact buffer area boundaries can contain circular arcs.
* To represent these arcs using linear geometry they must be approximated with line segments.
* The buffer geometry is constructed using 8 segments per quadrant to approximate
* the circular arcs.
* The end cap style is <tt>CAP_ROUND</tt>.
* <p>
* The buffer operation always returns a polygonal result. The negative or
* zero-distance buffer of lines and points is always an empty {@link Polygon}.
* This is also the result for the buffers of degenerate (zero-area) polygons.
*
* @param distance
* the width of the buffer (may be positive, negative or 0)
* @return a polygonal geometry representing the buffer region (which may be
* empty)
*
* @throws TopologyException
* if a robustness error occurs
*
* @see #buffer(double, int)
* @see #buffer(double, int, int)
*/
public Geometry buffer(double distance) {
return BufferOp.bufferOp(this, distance);
}
/**
* Computes a buffer area around this geometry having the given width and with
* a specified accuracy of approximation for circular arcs.
* <p>
* Mathematically-exact buffer area boundaries can contain circular arcs.
* To represent these arcs
* using linear geometry they must be approximated with line segments. The
* <code>quadrantSegments</code> argument allows controlling the accuracy of
* the approximation by specifying the number of line segments used to
* represent a quadrant of a circle
* <p>
* The buffer operation always returns a polygonal result. The negative or
* zero-distance buffer of lines and points is always an empty {@link Polygon}.
* This is also the result for the buffers of degenerate (zero-area) polygons.
*
* @param distance
* the width of the buffer (may be positive, negative or 0)
* @param quadrantSegments
* the number of line segments used to represent a quadrant of a
* circle
* @return a polygonal geometry representing the buffer region (which may be
* empty)
*
* @throws TopologyException
* if a robustness error occurs
*
* @see #buffer(double)
* @see #buffer(double, int, int)
*/
public Geometry buffer(double distance, int quadrantSegments) {
return BufferOp.bufferOp(this, distance, quadrantSegments);
}
/**
* Computes a buffer area around this geometry having the given
* width and with a specified accuracy of approximation for circular arcs,
* and using a specified end cap style.
* <p>
* Mathematically-exact buffer area boundaries can contain circular arcs.
* To represent these arcs using linear geometry they must be approximated with line segments.
* The <code>quadrantSegments</code> argument allows controlling the
* accuracy of the approximation
* by specifying the number of line segments used to represent a quadrant of a circle
* <p>
* The end cap style specifies the buffer geometry that will be
* created at the ends of linestrings. The styles provided are:
* <ul>
* <li><tt>BufferOp.CAP_ROUND</tt> - (default) a semi-circle
* <li><tt>BufferOp.CAP_BUTT</tt> - a straight line perpendicular to the end segment
* <li><tt>BufferOp.CAP_SQUARE</tt> - a half-square
* </ul>
* <p>
* The buffer operation always returns a polygonal result. The negative or
* zero-distance buffer of lines and points is always an empty {@link Polygon}.
* This is also the result for the buffers of degenerate (zero-area) polygons.
*
*@param distance the width of the buffer (may be positive, negative or 0)
*@param quadrantSegments the number of line segments used to represent a quadrant of a circle
*@param endCapStyle the end cap style to use
*@return a polygonal geometry representing the buffer region (which may be empty)
*
* @throws TopologyException if a robustness error occurs
*
* @see #buffer(double)
* @see #buffer(double, int)
* @see BufferOp
*/
public Geometry buffer(double distance, int quadrantSegments, int endCapStyle) {
return BufferOp.bufferOp(this, distance, quadrantSegments, endCapStyle);
}
/**
* Computes the smallest convex <code>Polygon</code> that contains all the
* points in the <code>Geometry</code>. This obviously applies only to <code>Geometry</code>
* s which contain 3 or more points; the results for degenerate cases are
* specified as follows:
* <TABLE>
* <TR>
* <TH> Number of <code>Point</code>s in argument <code>Geometry</code> </TH>
* <TH> <code>Geometry</code> class of result </TH>
* </TR>
* <TR>
* <TD> 0 </TD>
* <TD> empty <code>GeometryCollection</code> </TD>
* </TR>
* <TR> <TD> 1 </TD>
* <TD> <code>Point</code> </TD>
* </TR>
* <TR>
* <TD> 2 </TD>
* <TD> <code>LineString</code> </TD>
* </TR>
* <TR>
* <TD> 3 or more </TD>
* <TD> <code>Polygon</code> </TD>
* </TR>
* </TABLE>
*
*@return the minimum-area convex polygon containing this <code>Geometry</code>'
* s points
*/
public Geometry convexHull() {
return (new ConvexHull(this)).getConvexHull();
}
/**
* Computes a new geometry which has all component coordinate sequences
* in reverse order (opposite orientation) to this one.
*
* @return a reversed geometry
*/
public abstract Geometry reverse();
/**
* Computes a <code>Geometry</code> representing the points shared by this
* <code>Geometry</code> and <code>other</code>.
* {@link GeometryCollection}s support intersection with
* homogeneous collection types, with the semantics that
* the result is a {@link GeometryCollection} of the
* intersection of each element of the target with the argument.
*
* @param other the <code>Geometry</code> with which to compute the intersection
* @return the points common to the two <code>Geometry</code>s
* @throws TopologyException if a robustness error occurs
* @throws IllegalArgumentException if the argument is a non-empty GeometryCollection
*/
public Geometry intersection(Geometry other)
{
/**
* TODO: MD - add optimization for P-A case using Point-In-Polygon
*/
// special case: if one input is empty ==> empty
if (this.isEmpty()) return this.getFactory().createGeometryCollection(null);
if (other.isEmpty()) return this.getFactory().createGeometryCollection(null);
// compute for GCs
if (isGeometryCollection(this)) {
final Geometry g2 = other;
return GeometryCollectionMapper.map(
(GeometryCollection) this,
new GeometryCollectionMapper.MapOp() {
public Geometry map(Geometry g) {
return g.intersection(g2);
}
});
}
// if (isGeometryCollection(other))
// return other.intersection(this);
checkNotGeometryCollection(this);
checkNotGeometryCollection(other);
return SnapIfNeededOverlayOp.overlayOp(this, other, OverlayOp.INTERSECTION);
}
/**
* Computes a <code>Geometry</code> representing all the points in this <code>Geometry</code>
* and <code>other</code>.
*
*@param other the <code>Geometry</code> with which to compute the union
*@return a set combining the points of this <code>Geometry</code> and
* the points of <code>other</code>
* @throws TopologyException if a robustness error occurs
* @throws IllegalArgumentException if either input is a non-empty GeometryCollection
*/
public Geometry union(Geometry other)
{
// special case: if either input is empty ==> other input
if (this.isEmpty()) return (Geometry) other.clone();
if (other.isEmpty()) return (Geometry) clone();
// TODO: optimize if envelopes of geometries do not intersect
checkNotGeometryCollection(this);
checkNotGeometryCollection(other);
return SnapIfNeededOverlayOp.overlayOp(this, other, OverlayOp.UNION);
}
/**
* Computes a <code>Geometry</code> representing the points making up this
* <code>Geometry</code> that do not make up <code>other</code>. This method
* returns the closure of the resultant <code>Geometry</code>.
*
*@param other the <code>Geometry</code> with which to compute the
* difference
*@return the point set difference of this <code>Geometry</code> with
* <code>other</code>
* @throws TopologyException if a robustness error occurs
* @throws IllegalArgumentException if either input is a non-empty GeometryCollection
*/
public Geometry difference(Geometry other)
{
// mod to handle empty cases better - return type of input
//if (this.isEmpty() || other.isEmpty()) return (Geometry) clone();
// special case: if A.isEmpty ==> empty; if B.isEmpty ==> A
if (this.isEmpty()) return this.getFactory().createGeometryCollection(null);
if (other.isEmpty()) return (Geometry) clone();
checkNotGeometryCollection(this);
checkNotGeometryCollection(other);
return SnapIfNeededOverlayOp.overlayOp(this, other, OverlayOp.DIFFERENCE);
}
/**
* Returns a set combining the points in this <code>Geometry</code> not in
* <code>other</code>, and the points in <code>other</code> not in this
* <code>Geometry</code>. This method returns the closure of the resultant
* <code>Geometry</code>.
*
*@param other the <code>Geometry</code> with which to compute the symmetric
* difference
*@return the point set symmetric difference of this <code>Geometry</code>
* with <code>other</code>
* @throws TopologyException if a robustness error occurs
* @throws IllegalArgumentException if either input is a non-empty GeometryCollection
*/
public Geometry symDifference(Geometry other)
{
// special case: if either input is empty ==> other input
if (this.isEmpty()) return (Geometry) other.clone();
if (other.isEmpty()) return (Geometry) clone();
checkNotGeometryCollection(this);
checkNotGeometryCollection(other);
return SnapIfNeededOverlayOp.overlayOp(this, other, OverlayOp.SYMDIFFERENCE);
}
/**
* Computes the union of all the elements of this geometry. Heterogeneous
* {@link GeometryCollection}s are fully supported.
* <p>
* The result obeys the following contract:
* <ul>
* <li>Unioning a set of {@link LineString}s has the effect of fully noding
* and dissolving the linework.
* <li>Unioning a set of {@link Polygon}s will always
* return a {@link Polygonal} geometry (unlike {link #union(Geometry)},
* which may return geometrys of lower dimension if a topology collapse occurred.
* </ul>
*
* @return
*
* @see UnaryUnionOp
*/
public Geometry union() {
return UnaryUnionOp.union(this);
}
/**
* Returns true if the two <code>Geometry</code>s are exactly equal,
* up to a specified distance tolerance.
* Two Geometries are exactly equal within a distance tolerance
* if and only if:
* <ul>
* <li>they have the same class
* <li>they have the same values for their vertices,
* within the given tolerance distance, in exactly the same order.
* </ul>
* If this and the other <code>Geometry</code>s are
* composites and any children are not <code>Geometry</code>s, returns
* <code>false</code>.
*
* @param other the <code>Geometry</code> with which to compare this <code>Geometry</code>
* @parm tolerance distance at or below which two <code>Coordinate</code>s
* are considered equal
* @return <code>true</code> if this and the other <code>Geometry</code>
* are of the same class and have equal internal data.
*/
public abstract boolean equalsExact(Geometry other, double tolerance);
/**
* Returns true if the two <code>Geometry</code>s are exactly equal.
* Two Geometries are exactly equal iff:
* <ul>
* <li>they have the same class
* <li>they have the same values of Coordinates in their internal
* Coordinate lists, in exactly the same order.
* </ul>
* If this and the other <code>Geometry</code>s are
* composites and any children are not <code>Geometry</code>s, returns
* false.
* <p>
* This provides a stricter test of equality than
* <code>equals</code>.
*
*@param other the <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return <code>true</code> if this and the other <code>Geometry</code>
* are of the same class and have equal internal data.
*/
public boolean equalsExact(Geometry other) { return equalsExact(other, 0); }
/**
* Performs an operation with or on this <code>Geometry</code>'s
* coordinates.
* If this method modifies any coordinate values,
* {@link #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).
*
*@param filter the filter to apply to this <code>Geometry</code>'s
* coordinates
*/
public abstract void apply(CoordinateFilter filter);
/**
* Performs an operation on the coordinates in this <code>Geometry</code>'s
* {@link CoordinateSequence}s.
* If the filter reports that a coordinate value has been changed,
* {@link #geometryChanged} will be called automatically.
*
*@param filter the filter to apply
*/
public abstract void apply(CoordinateSequenceFilter filter);
/**
* Performs an operation with or on this <code>Geometry</code> and its
* subelement <code>Geometry</code>s (if any).
* Only GeometryCollections and subclasses
* have subelement Geometry's.
*
*@param filter the filter to apply to this <code>Geometry</code> (and
* its children, if it is a <code>GeometryCollection</code>).
*/
public abstract void apply(GeometryFilter filter);
/**
* 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.
*
*@param filter the filter to apply to this <code>Geometry</code>.
*/
public abstract void apply(GeometryComponentFilter filter);
/**
* Creates and returns a full copy of this {@link Geometry} object
* (including all coordinates contained by it).
* Subclasses are responsible for overriding this method and copying
* their internal data. Overrides should call this method first.
*
* @return a clone of this instance
*/
public Object clone() {
try {
Geometry clone = (Geometry) super.clone();
if (clone.envelope != null) { clone.envelope = new Envelope(clone.envelope); }
return clone;
}
catch (CloneNotSupportedException e) {
Assert.shouldNeverReachHere();
return null;
}
}
/**
* Converts this <code>Geometry</code> to <b>normal form</b> (or <b>
* canonical form</b> ). Normal form is a unique representation for <code>Geometry</code>
* s. It can be used to test whether two <code>Geometry</code>s 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.
*/
public abstract void normalize();
/**
* Returns whether this <code>Geometry</code> is greater than, equal to,
* or less than another <code>Geometry</code>. <P>
*
* If their classes are different, they are compared using the following
* ordering:
* <UL>
* <LI> Point (lowest)
* <LI> MultiPoint
* <LI> LineString
* <LI> LinearRing
* <LI> MultiLineString
* <LI> Polygon
* <LI> MultiPolygon
* <LI> GeometryCollection (highest)
* </UL>
* If the two <code>Geometry</code>s have the same class, their first
* elements are compared. If those are the same, the second elements are
* compared, etc.
*
*@param o a <code>Geometry</code> with which to compare this <code>Geometry</code>
*@return a positive number, 0, or a negative number, depending on whether
* this object is greater than, equal to, or less than <code>o</code>, as
* defined in "Normal Form For Geometry" in the JTS Technical
* Specifications
*/
public int compareTo(Object o) {
Geometry other = (Geometry) o;
if (getClassSortIndex() != other.getClassSortIndex()) {
return getClassSortIndex() - other.getClassSortIndex();
}
if (isEmpty() && other.isEmpty()) {
return 0;
}
if (isEmpty()) {
return -1;
}
if (other.isEmpty()) {
return 1;
}
return compareToSameClass(o);
}
/**
* Returns whether this <code>Geometry</code> is greater than, equal to,
* or less than another <code>Geometry</code>,
* using the given {@link CoordinateSequenceComparator}.
* <P>
*
* If their classes are different, they are compared using the following
* ordering:
* <UL>
* <LI> Point (lowest)
* <LI> MultiPoint
* <LI> LineString
* <LI> LinearRing
* <LI> MultiLineString
* <LI> Polygon
* <LI> MultiPolygon
* <LI> GeometryCollection (highest)
* </UL>
* If the two <code>Geometry</code>s have the same class, their first
* elements are compared. If those are the same, the second elements are
* compared, etc.
*
*@param o a <code>Geometry</code> with which to compare this <code>Geometry</code>
*@param comp a <code>CoordinateSequenceComparator</code>
*
*@return a positive number, 0, or a negative number, depending on whether
* this object is greater than, equal to, or less than <code>o</code>, as
* defined in "Normal Form For Geometry" in the JTS Technical
* Specifications
*/
public int compareTo(Object o, CoordinateSequenceComparator comp) {
Geometry other = (Geometry) o;
if (getClassSortIndex() != other.getClassSortIndex()) {
return getClassSortIndex() - other.getClassSortIndex();
}
if (isEmpty() && other.isEmpty()) {
return 0;
}
if (isEmpty()) {
return -1;
}
if (other.isEmpty()) {
return 1;
}
return compareToSameClass(o, comp);
}
/**
* Returns whether the two <code>Geometry</code>s are equal, from the point
* of view of the <code>equalsExact</code> method. Called by <code>equalsExact</code>
* . In general, two <code>Geometry</code> classes are considered to be
* "equivalent" only if they are the same class. An exception is <code>LineString</code>
* , which is considered to be equivalent to its subclasses.
*
*@param other the <code>Geometry</code> with which to compare this <code>Geometry</code>
* for equality
*@return <code>true</code> if the classes of the two <code>Geometry</code>
* s are considered to be equal by the <code>equalsExact</code> method.
*/
protected boolean isEquivalentClass(Geometry other) {
return this.getClass().getName().equals(other.getClass().getName());
}
/**
* Throws an exception if <code>g</code>'s class is <code>GeometryCollection</code>
* . (Its subclasses do not trigger an exception).
*
*@param g the <code>Geometry</code> to check
*@throws IllegalArgumentException if <code>g</code> is a <code>GeometryCollection</code>
* but not one of its subclasses
*/
protected void checkNotGeometryCollection(Geometry g) {
//Don't use instanceof because we want to allow subclasses
if (g.getClass().getName().equals("com.vividsolutions.jts.geom.GeometryCollection")) {
throw new IllegalArgumentException("This method does not support GeometryCollection arguments");
}
}
protected boolean isGeometryCollection(Geometry g)
{
return g.getClass().equals(com.vividsolutions.jts.geom.GeometryCollection.class);
}
/**
* Returns the minimum and maximum x and y values in this <code>Geometry</code>
* , or a null <code>Envelope</code> if this <code>Geometry</code> is empty.
* Unlike <code>getEnvelopeInternal</code>, this method calculates the <code>Envelope</code>
* each time it is called; <code>getEnvelopeInternal</code> caches the result
* of this method.
*
*@return this <code>Geometry</code>s bounding box; if the <code>Geometry</code>
* is empty, <code>Envelope#isNull</code> will return <code>true</code>
*/
protected abstract Envelope computeEnvelopeInternal();
/**
* Returns whether this <code>Geometry</code> is greater than, equal to,
* or less than another <code>Geometry</code> having the same class.
*
*@param o a <code>Geometry</code> having the same class as this <code>Geometry</code>
*@return a positive number, 0, or a negative number, depending on whether
* this object is greater than, equal to, or less than <code>o</code>, as
* defined in "Normal Form For Geometry" in the JTS Technical
* Specifications
*/
protected abstract int compareToSameClass(Object o);
/**
* Returns whether this <code>Geometry</code> is greater than, equal to,
* or less than another <code>Geometry</code> of the same class.
* using the given {@link CoordinateSequenceComparator}.
*
*@param o a <code>Geometry</code> having the same class as this <code>Geometry</code>
*@param comp a <code>CoordinateSequenceComparator</code>
*@return a positive number, 0, or a negative number, depending on whether
* this object is greater than, equal to, or less than <code>o</code>, as
* defined in "Normal Form For Geometry" in the JTS Technical
* Specifications
*/
protected abstract int compareToSameClass(Object o, CoordinateSequenceComparator comp);
/**
* Returns the first non-zero result of <code>compareTo</code> encountered as
* the two <code>Collection</code>s are iterated over. If, by the time one of
* the iterations is complete, no non-zero result has been encountered,
* returns 0 if the other iteration is also complete. If <code>b</code>
* completes before <code>a</code>, a positive number is returned; if a
* before b, a negative number.
*
*@param a a <code>Collection</code> of <code>Comparable</code>s
*@param b a <code>Collection</code> of <code>Comparable</code>s
*@return the first non-zero <code>compareTo</code> result, if any;
* otherwise, zero
*/
protected int compare(Collection a, Collection b) {
Iterator i = a.iterator();
Iterator j = b.iterator();
while (i.hasNext() && j.hasNext()) {
Comparable aElement = (Comparable) i.next();
Comparable bElement = (Comparable) j.next();
int comparison = aElement.compareTo(bElement);
if (comparison != 0) {
return comparison;
}
}
if (i.hasNext()) {
return 1;
}
if (j.hasNext()) {
return -1;
}
return 0;
}
protected boolean equal(Coordinate a, Coordinate b, double tolerance) {
if (tolerance == 0) { return a.equals(b); }
return a.distance(b) <= tolerance;
}
private int getClassSortIndex() {
if (sortedClasses == null)
initSortedClasses();
for (int i = 0; i < sortedClasses.length; i++) {
if (sortedClasses[i].isInstance(this))
return i;
}
Assert.shouldNeverReachHere("Class not supported: " + this.getClass());
return -1;
}
private static void initSortedClasses()
{
sortedClasses = new Class[] {
Point.class,
MultiPoint.class,
LineString.class,
LinearRing.class,
MultiLineString.class,
Polygon.class,
MultiPolygon.class,
GeometryCollection.class };
}
private Point createPointFromInternalCoord(Coordinate coord, Geometry exemplar)
{
exemplar.getPrecisionModel().makePrecise(coord);
return exemplar.getFactory().createPoint(coord);
}
}