001    /*
002     *    GeoAPI - Java interfaces for OGC/ISO standards
003     *    http://www.geoapi.org
004     *
005     *    Copyright (C) 2004-2012 Open Geospatial Consortium, Inc.
006     *    All Rights Reserved. http://www.opengeospatial.org/ogc/legal
007     *
008     *    Permission to use, copy, and modify this software and its documentation, with
009     *    or without modification, for any purpose and without fee or royalty is hereby
010     *    granted, provided that you include the following on ALL copies of the software
011     *    and documentation or portions thereof, including modifications, that you make:
012     *
013     *    1. The full text of this NOTICE in a location viewable to users of the
014     *       redistributed or derivative work.
015     *    2. Notice of any changes or modifications to the OGC files, including the
016     *       date changes were made.
017     *
018     *    THIS SOFTWARE AND DOCUMENTATION IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE
019     *    NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
020     *    TO, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT
021     *    THE USE OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY
022     *    PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
023     *
024     *    COPYRIGHT HOLDERS WILL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL OR
025     *    CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE OR DOCUMENTATION.
026     *
027     *    The name and trademarks of copyright holders may NOT be used in advertising or
028     *    publicity pertaining to the software without specific, written prior permission.
029     *    Title to copyright in this software and any associated documentation will at all
030     *    times remain with copyright holders.
031     */
032    package org.opengis.geometry.coordinate;
033    
034    import org.opengis.geometry.DirectPosition;
035    import org.opengis.annotation.UML;
036    
037    import static org.opengis.annotation.Obligation.*;
038    import static org.opengis.annotation.Specification.*;
039    
040    
041    /**
042     * Common interface for {@linkplain org.opengis.geometry.primitive.Surface surface} and
043     * {@linkplain org.opengis.geometry.primitive.SurfacePatch surface patch}. {@code Surface}
044     * and {@code SurfacePatch} represent sections of surface geometry,
045     * and therefore share a number of operation signatures.
046     *
047     * @version <A HREF="http://www.opengeospatial.org/standards/as">ISO 19107</A>
048     * @author Martin Desruisseaux (IRD)
049     * @since GeoAPI 1.0
050     *
051     * @todo Investigate why this interface doesn't extends {@link Geometry}, since it is a cause
052     *       of difficulty with {@link org.opengis.coverage.Coverage}.
053     */
054    @UML(identifier="GM_GenericSurface", specification=ISO_19107)
055    public interface GenericSurface {
056        /**
057         * Returns a vector perpendicular to the {@code GenericSurface} at the
058         * {@linkplain DirectPosition direct position} passed, which must be on this
059         * {@code GenericSurface}. The upward normal always points upward in a
060         * manner consistent with the boundary. This means that the exterior boundary
061         * of the surface is counterclockwise when viewed from the side of the surface
062         * indicated by the {@code upNormal}. Interior boundaries are clockwise.
063         * The side of the surface indicated by the {@code upNormal} is referred
064         * to as the "top." The function "upNormal" shall be continuous and the length
065         * of the normal shall always be equal to 1.0.
066         *
067         * <blockquote><font size=2>
068         * <strong>NOTE:</strong> The upNormal along a boundary of a solid always points away from the
069         * solid. This is a slight semantics problem in dealing with voids within solids, where the
070         * upNormal (for sake of mathematical consistency) points into the center of the voided region,
071         * which linguistically can be considered the interior of the void. What the confusion is here
072         * is that the basic linguistic metaphors used in most languages for "interior of solid" and
073         * for "interior of container" use "inward" in inconsistent manners from a topological point
074         * of view. The void "in" rock is not inside the rock in the same manner as the solid material
075         * that makes up the substance of the rock. Nor is the coffee "in" the cup the same "in" as
076         * the ceramic glass "in" the cup. The use of these culturally derived metaphors may not be
077         * consistent across all languages, some of which may use different prepositions for these two
078         * different concepts. This specification uses the linguistically neutral concept of "interior"
079         * derived from mathematics (topology).
080         * </font></blockquote>
081         *
082         * @param point The point on this {@code GenericSurface} where to compute the upNormal.
083         * @return The upNormal unit vector.
084         */
085        @UML(identifier="upNormal", obligation=MANDATORY, specification=ISO_19107)
086        double[] getUpNormal(DirectPosition point);
087    
088        /**
089         * Returns the sum of the lengths of all the boundary components of this
090         * {@code GenericSurface}. Since perimeter, like length, is an accumulation
091         * (integral) of distance, its return value shall be in a reference system appropriate
092         * for measuring distances.
093         *
094         * <blockquote><font size=2>
095         * <strong>NOTE:</strong> The perimeter is defined as the sum of the lengths of all boundary
096         * components. The length of a curve or of a collection of curves is always positive and
097         * non-zero (unless the curve is pathological). This means that holes in surfaces will
098         * contribute positively to the total perimeter.
099         * </font></blockquote>
100         *
101         * @return The perimeter.
102         * @unitof Length
103         */
104        @UML(identifier="perimeter", obligation=MANDATORY, specification=ISO_19107)
105        double getPerimeter();
106    
107        /**
108         * Returns the area of this {@code GenericSurface}. The area of a 2-dimensional geometric
109         * object shall be a numeric measure of its surface area (in a square unit of distance). Since
110         * area is an accumulation (integral) of the product of two distances, its return value shall
111         * be in a unit of measure appropriate for measuring distances squared, such as meters squared
112         * (m<sup>2</sup>).
113         *
114         * <blockquote><font size=2>
115         * <strong>NOTE:</strong> Consistent with the definition of surface as a set of
116         * {@linkplain DirectPosition direct positions}, holes in the surfaces will not contribute to
117         * the total area. If the usual Green's Theorem (or more general Stokes' Theorem) integral is
118         * used, the integral around the holes in the surface are subtracted from the integral
119         * about the exterior of the surface patch.
120         * </font></blockquote>
121         *
122         * @return The area.
123         * @unitof Area
124         */
125        @UML(identifier="area", obligation=MANDATORY, specification=ISO_19107)
126        double getArea();
127    }