/*$************************************************************************************************
 **
 ** $Id: Surface.java 831 2006-05-01 00:27:23Z Desruisseaux $
 **
 ** $URL: http://svn.code.sf.net/p/geoapi/code/branches/2.0.x/geoapi/src/main/java/org/opengis/spatialschema/geometry/primitive/Surface.java $
 **
 ** Copyright (C) 2003-2005 Open GIS Consortium, Inc.
 ** All Rights Reserved. http://www.opengis.org/legal/
 **
 *************************************************************************************************/
package org.opengis.spatialschema.geometry.primitive;

// J2SE direct dependencies
import java.util.List;

// OpenGIS direct dependencies
import org.opengis.spatialschema.geometry.geometry.GenericSurface;

// Annotations
import org.opengis.annotation.UML;
import static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;


/**
 * Surface with a positive orientation.
 * {@code Surface} is a subclass of {@link Primitive} and is the basis for 2-dimensional
 * geometry. Unorientable surfaces such as the Möbius band are not allowed. The orientation of
 * a surface chooses an "up" direction through the choice of the upward normal, which, if the
 * surface is not a cycle, is the side of the surface from which the exterior boundary appears
 * counterclockwise. Reversal of the surface orientation reverses the curve orientation of each
 * boundary component, and interchanges the conceptual "up" and "down" direction of the surface.
 * If the surface is the boundary of a solid, the "up" direction is usually outward. For closed
 * surfaces, which have no boundary, the up direction is that of the surface patches, which must
 * be consistent with one another. Its included {@linkplain SurfacePatch surface patches} describe
 * the interior structure of a {@code Surface}.
 *
 * 

 * NOTE: Other than the restriction on orientability, no other "validity" condition is required for GM_Surface.
 * 
 *
 * @version Abstract specification 5
 * @author Martin Desruisseaux (IRD)
 * @since GeoAPI 1.0
 *
 * @see PrimitiveFactory#createSurface(List)
 * @see PrimitiveFactory#createSurface(SurfaceBoundary)
 */
@UML(identifier="GM_Surface", specification=ISO_19107)
public interface Surface extends OrientableSurface, GenericSurface {
    /**
     * Relates this {@code Surface} to a set of {@linkplain SurfacePatch surface patches} that
     * shall be joined together to form this surface. Depending on the interpolation method, the set
     * of patches may require significant additional structure.
     *
     * If the surface {@linkplain #getCoordinateDimension coordinate dimension} is 2, then the
     * entire {@code Surface} is one logical patch defined by linear interpolation from the
     * boundary.
     *
     * @return The list of surface patches. Should never be {@code null} neither empty.
     *
     * @see SurfacePatch#getSurface
     */
    @UML(identifier="patch", obligation=MANDATORY, specification=ISO_19107)
    List getPatches();
}