Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.symbology.fmap.mapcontext.rendering.symbol.impl;

import org.gvsig.fmap.mapcontext.MapContext;

import org.gvsig.fmap.mapcontext.ViewPort;

import org.gvsig.fmap.mapcontext.rendering.symbols.CartographicSupport;

/**

 * @author jaume dominguez faus - jaume.dominguez@iver.es

 */

public class CartographicSupportToolkit {

        /**

         * Calculates the distance in pixels corresponding to the provided length,

         * according to the current rendering context (output dpi, map scale, map units) and the

         * symbol cartographic settings (unit, size, and unit reference system).

         *

         * @param cartographicElement CartographicSupport object which contains the reference system

         * and the measuring units for the provided length

         * @param length The length to be computed in pixels. The length is supposed to be

         * provided in the units defined in the cartographicElement

         * @param viewPort The viewport, which defines the relationship between pixels and maps units

         * @param dpi The resolution (dots per inch) of the target display device

         * (printer, screen, etc)

         * @return The distance in pixels corresponding to the provided length

         */

        public static double getCartographicLength(CartographicSupport cartographicElement, double length, ViewPort viewPort, double dpi) {

                int unit = cartographicElement.getUnit();

                double lengthInPixel = length;

                if (unit != -1) {

                        double[] trans2Meter=MapContext.getDistanceTrans2Meter();

                        if (cartographicElement.getReferenceSystem() == CartographicSupport.WORLD) {

                                double dist1PixelInMeters = viewPort.getDist1pixel()*trans2Meter[viewPort.getMapUnits()];

                                double realWidthMeter = length*trans2Meter[unit];

                                lengthInPixel = realWidthMeter/dist1PixelInMeters;

                        } else if (cartographicElement.getReferenceSystem() == CartographicSupport.PAPER) {

                                double lengthInInches = 1/trans2Meter[7]*trans2Meter[unit]*length;

                                lengthInPixel = lengthInInches*dpi;

                        }

                } else{

                        double scale=dpi/72;

                        lengthInPixel=lengthInPixel*scale;

                }

                return  (lengthInPixel);

        }

        /**

         * The unit that will be used when creating new symbols.<br>

         * <b>Factory defaults to pixel.</b>

         */

        public static int DefaultMeasureUnit = -1;

        /**

         * The reference system that will be used when creating new symbols.<br>

         * <b>Factory defaults to pixel.</b>

         */

        public static int DefaultReferenceSystem = CartographicSupport.WORLD;

}