/*
 *    Geotoolkit.org - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2008-2012, Open Source Geospatial Foundation (OSGeo)
 *    (C) 2009-2012, 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;
 *    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.geotoolkit.referencing.operation.transform;


/**
 * Whatever the grid values backing a {@link GridTransform} are directly the target coordinates
 * or offsets to apply on the source coordinates. If grid values are offsets, they may be added
 * directly to the source coordinates ({@link #OFFSET}) or they may be pre-multiplied by some
 * factor before to be added to source coordinates ({@link #NADCON}, {@link #NTv2}).
 *
 * {@note The special offset cases (<code>NADCON</code>, <code>NTv2</code>) are not strictly
 * necessary since it would be possible to pre-multiply the scale factor straight in the grid.
 * However the approach taken by <code>GridTransform</code> is to keep major formats unchanged.
 * This approach allows for example a <code>RenderedImage</code> to share the same
 * <code>DataBuffer</code> than the one used by <code>GridTransform</code>, and compare
 * the visual aspect with publications.}
 *
 * @author Martin Desruisseaux (Geomatys)
 * @version 3.12
 *
 * @since 3.00
 * @module
 *
 * @deprecated Replaced by {@link org.apache.sis.referencing.operation.transform.InterpolatedTransform}
 */
@Deprecated
public enum GridType {
    /**
     * The grid values give directly the target coordinates. The source coordinates
     * are discarded after the interpolation.
     */
    LOCALIZATION,

    /**
     * The grid values are offsets to add to source coordinates. The source and target
     * coordinates can be in any CRS. In the typical case where to source or the target
     * CRS is {@linkplain org.geotoolkit.referencing.crs.DefaultGeographicCRS#WGS84 WGS84},
     * then the offsets are in decimal degrees with longitude offset positive toward east
     * and latitude offset positive toward north.
     */
    OFFSET,

    /**
     * The grid values are offsets to apply on source coordinates in seconds of angle.
     * Longitude offset is positive toward <strong>west</strong> and latitude offset is
     * positive toward north. Longitudes in the west hemisphere are negatives.
     */
    NADCON,

    /**
     * Same as {@link #NADCON}, except that longitudes in the west hemisphere are positives.
     *
     * @since 3.12
     */
    NTv2;
}