/*
* Geotoolkit - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2008 - 2009, Geomatys
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotoolkit.style.function;
import org.opengis.annotation.XmlElement;
import org.opengis.filter.expression.Expression;
/**
* The InterpolationPoints have to be specified in ascending order of Data. They define a
* graph of points. LookupValues less than the Data value of the first InterpolationPoint
* are mapped to its corresponding Value. Accordingly, LookupValues greater than the
* Data value of the last InterpolationPoint are mapped to the Value of this one.
* LookupValues between two InterpolationPoints are interpolated between the
* corresponding Values.
*
* Only numeric quantities are allowed for LookupValue and Data. Values are usually
* numeric as well. The interpolation of color-values requires the attribute mode="color" at
* the Interpolate element.s
*
* @version <A HREF="http://www.opengeospatial.org/standards/symbol">Symbology Encoding Implementation Specification 1.1.0</A>
* @author Johann Sorel (Geomatys)
* @module
*/
@XmlElement("InterpolationPoint")
public interface InterpolationPoint {
/**
* Get value.
*
* The Values can be of any type, dependent on which symbolization context the function is
* employed. Color values (like #00ffff) or numeric values are typical.
*
* @return Expression
*/
@XmlElement("Value")
Expression getValue();
/**
* Get data.
*
* @return double
*/
@XmlElement("Data")
Number getData();
}