/*
* 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.*;
/**
* A piecewise parametric polynomial or rational curve described
* in terms of control points and basis functions. If the weights in the knots are equal
* then it is a polynomial spline. If not, then it is a rational function spline. If
* the boolean {@link #isPolynomial} is set to {@code true} then the weights shall all be set to 1.
* A B-spline curve is a piecewise Bézier curve if it is quasi-uniform except that the
* interior knots have multiplicity "degree" rather than having multiplicity one. In
* this subtype the knot spacing shall be 1.0, starting at 0.0. A piecewise Bézier curve
* that has only two knots, 0.0, and 1.0, each of multiplicity (degree+1), is equivalent
* to a simple Bézier curve.
*
*
* @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/opengis/src/main/java/org/opengis/geometry/coordinate/BSplineCurve.java $
* @version <A HREF="http://www.opengeospatial.org/standards/as">ISO 19107</A>
* @author Martin Desruisseaux (IRD)
* @since GeoAPI 2.0
*
* @see GeometryFactory#createBSplineCurve
*/
@UML(identifier="GM_BSplineCurve", specification=ISO_19107)
public interface BSplineCurve extends SplineCurve {
/**
* The algebraic degree of the basis functions.
*/
@UML(identifier="degree", obligation=MANDATORY, specification=ISO_19107)
int getDegree();
/**
* Identifies particular types of curve which this spline is being used to
* approximate. It is for information only, used to capture the original intention.
* If no such approximation is intended, then the value of this attribute is {@code null}.
*/
@UML(identifier="curveForm", obligation=OPTIONAL, specification=ISO_19107)
SplineCurveForm getCurveForm();
/**
* Gives the type of knot distribution used in defining this spline.
* This is for information only and is set according to the different construction-functions.
*/
@UML(identifier="knotSpec", obligation=OPTIONAL, specification=ISO_19107)
KnotType getKnotSpec();
/**
* {@code true} if this is a polynomial spline.
*/
@UML(identifier="isPolynomial", obligation=MANDATORY, specification=ISO_19107)
boolean isPolynomial();
}