/*$************************************************************************************************
 **
 ** $Id: SurfacePatch.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/SurfacePatch.java $
 **
 ** Copyright (C) 2003-2005 Open GIS Consortium, Inc.
 ** All Rights Reserved. http://www.opengis.org/legal/
 **
 *************************************************************************************************/
package org.opengis.spatialschema.geometry.primitive;

// 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.*;


/**
 * Defines a homogeneous portion of a {@linkplain Surface surface}.
 * Each {@code SurfacePatch} shall be in at most one {@linkplain Surface surface}.
 *
 * @version Abstract specification 5
 * @author Martin Desruisseaux (IRD)
 * @since GeoAPI 1.0
 */
@UML(identifier="GM_SurfacePatch", specification=ISO_19107)
public interface SurfacePatch extends GenericSurface {
    /**
     * Returns the patch which own this surface patch.
     *
     * 

     * NOTE: In this specification, surface patches do not appear except in the
     * context of a surface, and therefore this method should never returns {@code null}
     * which would preclude the use of surface patches except in this manner. While this would
     * not affect this specification, allowing {@code null} owner allows other standards
     * based on this one to use surface patches in a more open-ended manner.
     * 
     *
     * @return The owner of this surface patch, or {@code null} if none.
     *
     * @see Surface#getPatches
     */
    @UML(identifier="surface", obligation=MANDATORY, specification=ISO_19107)
    public Surface getSurface();

    /**
     * Determines the surface interpolation mechanism used for this {@code SurfacePatch}.
     * This mechanism uses the control points and control parameters defined in the various
     * subclasses to determine the position of this {@code SurfacePatch}.
     *
     * @return The interpolation mechanism.
     */
    @UML(identifier="interpolation", obligation=MANDATORY, specification=ISO_19107)
    public SurfaceInterpolation getInterpolation();

    /**
     * Specifies the type of continuity between this surface patch and its immediate neighbors
     * with which it shares a boundary curve. The sequence of values corresponds to the
     * {@linkplain Ring rings} in the {@linkplain SurfaceBoundary surface boundary} returned by
     * {@link #getBoundary} for this patch. The default value of "0" means simple continuity, which
     * is a mandatory minimum level of continuity. This level is referred to as "C0" in
     * mathematical texts. A value of 1 means that the functions are continuous and differentiable
     * at the appropriate end point: "C1" continuity. A value of "n" for any integer means
     * n-times differentiable: "Cn" continuity.
     *
     * @return The type of continuity between this surface patch and its immediate neighbors.
     */
    @UML(identifier="numDerivativesOnBoundary", obligation=MANDATORY, specification=ISO_19107)
    public int getNumDerivativesOnBoundary();

    /**
     * Returns the boundary of this {@code SurfacePatch} represented as a collection of
     * {@linkplain OrientableCurve orientable curves} organized into {@linkplain Ring rings}
     * by a {@linkplain SurfaceBoundary surface boundary}. The semantics of this operation is
     * the same as that of {@link Surface#getBoundary()}, except that the curves used here may
     * be not be persistent {@linkplain OrientableCurve orientable curve} instances. Transient
     * data type values of {@linkplain Curve curve} are also valid. In the normal case,
     * {@code SurfacePatch}es will share parts of their boundary with the aggregate
     * {@linkplain Surface surface}, and other parts with {@code SurfacePatch}es (not
     * necessarily distinct).
     *
     * @return The boundary of this {@code SurfacePatch}
     */
    @UML(identifier="boundary", obligation=MANDATORY, specification=ISO_19107)
    public SurfaceBoundary getBoundary();
}