/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 * 
 *    (C) 2008, Open Source Geospatial Foundation (OSGeo)
 *
 *    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;
 *    version 2.1 of the License.
 *
 *    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.geotools.filter.function;

import org.geotools.data.Query;
import org.opengis.coverage.grid.GridGeometry;
import org.opengis.filter.expression.Function;

/**
 * An interface to be implemented by processes or by filter functions meant to be integrated as
 * feature collection/grid coverage transformations in a rendering chain.
 * <p>
 * These functions are meant to take one layer (raster or vector) and apply transformations on top
 * of it
 * <p>
 * The method provide information about how the data is altered so that the renderer can query the
 * appropriate part of the input data that will feed the process/function
 * </p>
 * 
 * @author Andrea Aime - GeoSolutions
 *
 * @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/main/src/main/java/org/geotools/filter/function/RenderingTransformation.java $
 */
public interface RenderingTransformation extends Function {

    /**
     * Given a target query and a target grid geometry returns the query to be used to read the
     * input data of the function This method will be called only if the input data is a feature
     * collection.
     * 
     * @param targetQuery
     * @param gridGeometry
     * @return The transformed query, or null if no inversion is possible/meaningful
     */
    Query invertQuery(Query targetQuery, GridGeometry gridGeometry);

    /**
     * Given a target query and a target grid geometry returns the grid geometry to be used to read
     * the input data of the function involved in rendering. This method will be called only if the
     * input data is a grid coverage or a grid coverage reader
     * 
     * @param targetQuery
     * @param gridGeometry
     * @return The transformed query, or null if no inversion is possible/meaningful
     */
    GridGeometry invertGridGeometry(Query targetQuery, GridGeometry targetGridGeometry);
}