geometry.java

GEo 地理操作源代码

/*$************************************************************************************************
 **
 ** $Id: Geometry.java,v 1.15.2.2 2004/05/18 11:20:28 desruisseaux Exp $
 **
 ** $Source: /cvsroot/geoapi/src/org/opengis/spatialschema/geometry/Geometry.java,v $
 **
 ** Copyright (C) 2003 Open GIS Consortium, Inc. All Rights Reserved. http://www.opengis.org/Legal/
 **
 *************************************************************************************************/
package org.opengis.spatialschema.geometry;

import java.util.Set;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.IncompatibleOperationException;
import org.opengis.referencing.operation.MathTransform;
import org.opengis.referencing.operation.TransformException;
import org.opengis.spatialschema.geometry.complex.Complex;


/**
 * Root class of the geometric object taxonomy. <code>Geometry</code> supports interfaces common
 * to all geographically referenced geometric objects. <code>Geometry</code> instances are sets
 * of direct positions in a particular coordinate reference system. A <code>Geometry</code> can
 * be regarded as an infinite set of points that satisfies the set operation interfaces for a set
 * of direct positions, {@link TransfiniteSet TransfiniteSet&lt;DirectPosition&gt;}.
 *
 * @UML type GM_Object
 * @rename Renamed as <code>Geometry</code> in order to avoid ambiguity with
 *         {@link java.lang.Object}.
 *
 * @author ISO/DIS 19107
 * @author <A HREF="http://www.opengis.org">OpenGIS&reg; consortium</A>
 * @version 2.0
 */
public interface Geometry extends TransfiniteSet {
    /**
     * Returns the coordinate reference system used in {@linkplain DirectPosition direct position}
     * coordinates. If <code>null</code>, then this <code>Geometry</code> uses the coordinate reference
     * system from another <code>Geometry</code> in which it is contained.
     *
     * The most common example where the coordinate reference system is <code>null</code> is the elements
     * and subcomplexes of a maximal {@linkplain Complex complex}. The {@linkplain Complex complex} can
     * carry the {@linkplain CoordinateReferenceSystem coordinate reference system} for all
     * {@linkplain org.opengis.spatialschema.geometry.primitive.Primitive primitive} elements
     * and for all {@link Complex} subcomplexes.
     * <br><br>
     * This association is only navigable from <code>Geometry</code> to {@linkplain CoordinateReferenceSystem
     * coordinate reference system}. This means that the coordinate reference system objects in a data set do
     * not keep a list of <code>Geometry</code>s that use them.
     *
     * @return The coordinate reference system used in {@linkplain DirectPosition direct position}
     *         coordinates.
     * @UML association CRS
     *
     * @see #getCoordinateDimension
     */
    public CoordinateReferenceSystem getCoordinateReferenceSystem();

    /**
     * Returns a region in the coordinate reference system that contains this <code>Geometry</code>.
     * The default shall be to return an instance of an appropriate <code>Geometry</code> subclass
     * that represents the same spatial set returned from {@link #getEnvelope}. The most common
     * use of <code>mbRegion</code> will be to support indexing methods that use extents other
     * than minimum bounding rectangles (MBR or envelopes). This does not restrict the returned
     * <code>Geometry</code> from being a non-vector geometric representation, although those
     * types are not defined within this specification.
     *
     * @return The minimum bounding region.
     * @UML operation mbRegion
     *
     * @see #getEnvelope
     * @see #getBoundary
     */
    public Geometry getMbRegion();

    /**
     * Returns a point value that is guaranteed to be on this <code>Geometry</code>. The default
     * logic may be to use the {@linkplain DirectPosition direct position} of the point returned by
     * {@link #getCentroid} if that point is on the object. Another use of representative point may
     * be for the placement of labels in systems based on graphic presentation.
     *
     * @return The representative point.
     * @UML operation representativePoint
     *
     * @see #getCentroid
     */
    public DirectPosition getRepresentativePoint();

    /**
     * Returns a finite set of <code>Geometry</code>s containing all of the direct positions on the
     * boundary of this <code>Geometry</code>. These object collections shall have further internal
     * structure where appropriate. The finite set of <code>Geometry</code>s returned shall be in
     * the same coordinate reference system as this <code>Geometry</code>. If the <code>Geometry</code>
     * is in a {@linkplain Complex complex}, then the boundary <code>Geometry</code>s returned shall be
     * in the same {@linkplain Complex complex}. If the <code>Geometry</code> is not in any
     * {@linkplain Complex complex}, then the boundary <code>Geometry</code>s returned may have been
     * constructed in response to the operation. The elements of a boundary shall be smaller in
     * dimension than the original element.
     *
     * @return The sets of positions on the boundary.
     * @UML operation boundary
     *
     * @see #getMbRegion
     * @see #getClosure
     * @see #getBuffer
     * @see #getDistance
     */
    public Boundary getBoundary();

    /**
     * Returns a finite set of <code>Geometry</code>s containing all of the points on the boundary of
     * this <code>Geometry</code> and this object (the union of the object and its boundary). These
     * object collections shall have further internal structure where appropriate. The finite set
     * of <code>Geometry</code>s returned shall be in the same coordinate reference system as this
     * <code>Geometry</code>. If the <code>Geometry</code> is in a {@linkplain Complex complex}, then the boundary
     * <code>Geometry</code>s returned shall be in the same {@linkplain Complex complex}. If the
     * <code>Geometry</code> is not in any {@linkplain Complex complex}, then the boundary
     * <code>Geometry</code>s returned may have been constructed in response to the operation.
     *
     * @return The sets of points on the union of this object and its boundary.
     * @UML operation closure
     *
     * @see #getBoundary
     */
    public Complex getClosure();

    /**
     * Returns <code>true</code> if this <code>Geometry</code> has no interior point of
     * self-intersection or selftangency. In mathematical formalisms, this means that
     * every point in the interior of the object must have a metric neighborhood whose
     * intersection with the object is isomorphic to an <var>n</var>-sphere, where <var>n</var>
     * is the dimension of this <code>Geometry</code>.
     * <br><br>
     * Since most coordinate geometries are represented, either directly or indirectly by functions
     * from regions in Euclidean space of their topological dimension, the easiest test for
     * simplicity to require that a function exist that is one-to-one and bicontinuous
     * (continuous in both directions). Such a function is a topological isomorphism. This test
     * does not work for "closed" objects (that is, objects for which {@link #isCycle} returns
     * <code>true</code>).
     *
     * @return <code>true</code> if this object has no interior point of self-intersection or
     *         selftangency.
     * @UML operation isSimple
     *
     * @see #isCycle
     */
    public boolean isSimple();

    /**
     * Returns <code>true</code> if this <code>Geometry</code> has an empty boundary after topological
     * simplification (removal of overlaps between components in non-structured aggregates, such as
     * subclasses of {@link org.opengis.spatialschema.geometry.aggregate.Aggregate}). This condition is alternatively
     * referred to as being "closed" as in a "closed curve." This creates some confusion since there
     * are two distinct and incompatible definitions for the word "closed". The use of the word cycle
     * is rarer (generally restricted to the field of algebraic topology), but leads to less confusion.
     * Essentially, an object is a cycle if it is isomorphic to a geometric object that is the
     * boundary of a region in some Euclidean space. Thus a curve is a cycle if it is isomorphic
     * to a circle (has the same start and end point). A surface is a cycle if it isomorphic to the
     * surface of a sphere, or some torus. A solid, with finite size, in a space of dimension 3 is
     * never a cycle.
     *
     * @return <code>true</code> if this <code>Geometry</code> has an empty boundary after
     *         topological simplification.
     * @UML operation isCycle
     *
     * @see #isSimple
     */
    public boolean isCycle();

    /**
     * Returns the distance between this <code>Geometry</code> and another <code>Geometry</code>.
     * This distance is defined to be the greatest lower bound of the set of distances between
     * all pairs of points that include one each from each of the two <code>Geometry</code>s. A