/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2011, Open Source Geospatial Foundation (OSGeo)
* (C) 2003-2005, Open Geospatial Consortium Inc.
*
* All Rights Reserved. http://www.opengis.org/legal/
*/
package org.opengis.geometry.coordinate;
import org.opengis.annotation.UML;
import static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;
/**
* Controls the constructive parameter space for spline curves and surfaces. Each knot sequence
* is used for a dimension of the spline's parameter space. Thus, in a surface spline, there will
* be two knot sequences, one for each parameter (<var>u</var>, <var>v</var>).
* The <var>i</var><sup>th</sup>, <var>j</var><sup>th</sup> would be (<var>u<sub>i</sub></var>,
* <var>v<sub>j</sub></var>), where the original knot sequences were (<var>u<sub>i</sub></var>)
* and (<var>v<sub>j</sub></var>). Each knot of a spline curve or surface is described using a
* {@code Knot}.
*
*
* @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/opengis/src/main/java/org/opengis/geometry/coordinate/Knot.java $
* @version <A HREF="http://www.opengeospatial.org/standards/as">ISO 19107</A>
* @author Martin Desruisseaux (IRD)
* @since GeoAPI 2.0
*/
@UML(identifier="GM_Knot", specification=ISO_19107)
public interface Knot {
/**
* The value of the parameter at the knot of the spline. The sequence of knots shall be a
* nondecreasing sequence. That is, each knot's value in the sequence shall be equal to or
* greater than the previous knot's value. The use of equal consecutive knots is normally
* handled using the multiplicity.
*/
@UML(identifier="value", obligation=MANDATORY, specification=ISO_19107)
double getValue();
/**
* The multiplicity of this knot used in the definition of the spline (with the same weight).
*/
@UML(identifier="multiplicity", obligation=MANDATORY, specification=ISO_19107)
int getMultiplicity();
/**
* The value of the averaging weight used for this knot of the spline.
*/
@UML(identifier="weight", obligation=MANDATORY, specification=ISO_19107)
double getWeight();
}