jts.rar_gis java

/* * 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.Collection; import java.util.Iterator; import com.vividsolutions.jts.algorithm.*; import com.vividsolutions.jts.io.WKTWriter; 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.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 1.7.2 */ public abstract class Geometry implements Cloneable, Comparable, Serializable { private static final long serialVersionUID = 8763622679187376702L; /** * The bounding box of this <code>Geometry</code>. */ protected Envelope envelope; private final static Class[] sortedClasses = new Class[] { Point.class, MultiPoint.class, LineString.class, LinearRing.class, MultiLineString.class, Polygon.class, MultiPolygon.class, GeometryCollection.class }; private final static GeometryComponentFilter geometryChangedFilter = new GeometryComponentFilter() { public void filter(Geometry geom) { geom.geometryChangedAction(); } }; public Geometry(GeometryFactory factory) { this.factory = factory; this.SRID = factory.getSRID(); } private GeometryFactory factory; /** * The ID of the Spatial Reference System used by this <code>Geometry</code> */ protected int SRID; /** * 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 */ //I wonder if we need this method, now that we have renamed the classes to //what their old interfaces were named. Now we can perhaps simply use //getClass().getName(). Who calls this method anyway? [Jon Aquino] 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 (!geomet