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The main module contains the GeoTools public interfaces that are used by other GeoTools modules (and GeoTools applications). Where possible we make use industry standard terms as provided by OGC and ISO standards. The formal GeoTools public api consists of gt-metadata, jts and the gt-main module. The main module contains the default implementations that are available provided to other GeoTools modules using our factory system. Factories are obtained from an appropriate FactoryFinder, giving applications a chance configure the factory used using the Factory Hints facilities. FilterFactory ff = CommonFactoryFinder.getFilterFactory(); Expression expr = ff.add( expression1, expression2 ); If you find yourself using implementation specific classes chances are you doing it wrong: Expression expr = new AddImpl( expression1, expressiom2 );

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/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2002-2008, 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.renderer.crs;

import org.geotools.geometry.jts.JTS;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.referencing.CRS;
import org.geotools.referencing.operation.projection.EquidistantConic;
import org.geotools.referencing.operation.projection.LambertConformal;
import org.geotools.referencing.operation.projection.LambertConformal1SP;
import org.geotools.referencing.operation.projection.MapProjection;
import org.geotools.referencing.operation.projection.MapProjection.AbstractProvider;
import org.locationtech.jts.geom.Envelope;
import org.locationtech.jts.geom.MultiPolygon;
import org.locationtech.jts.geom.Polygon;
import org.opengis.parameter.ParameterValueGroup;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;

/**
 * Returns a {@link ProjectionHandler} for the {@link LambertConformal} projection that will cut
 * geometries too close to pole on the open ended side of the cone.
 *
 * @author Andrea Aime - GeoSolutions
 */
public class ConicHandlerFactory implements ProjectionHandlerFactory {

    static final double EPS = 0.1;
    static final double MAX_DISTANCE = 44;

    public ProjectionHandler getHandler(
            ReferencedEnvelope renderingEnvelope,
            CoordinateReferenceSystem sourceCrs,
            boolean wrap,
            int maxWraps)
            throws FactoryException {
        if (renderingEnvelope == null) {
            return null;
        }

        MapProjection mapProjection =
                CRS.getMapProjection(renderingEnvelope.getCoordinateReferenceSystem());
        if (mapProjection instanceof LambertConformal
                || mapProjection instanceof EquidistantConic) {
            ParameterValueGroup params = mapProjection.getParameterValues();
            double centralMeridian =
                    params.parameter(AbstractProvider.CENTRAL_MERIDIAN.getName().getCode())
                            .doubleValue();
            double minLat, maxLat;

            double latitudeOrigin;
            if (mapProjection instanceof LambertConformal1SP) {
                latitudeOrigin =
                        params.parameter(AbstractProvider.LATITUDE_OF_ORIGIN.getName().getCode())
                                .doubleValue();
            } else {
                double stdParallel1 =
                        params.parameter(AbstractProvider.STANDARD_PARALLEL_1.getName().getCode())
                                .doubleValue();
                double stdParallel2 =
                        params.parameter(AbstractProvider.STANDARD_PARALLEL_2.getName().getCode())
                                .doubleValue();
                latitudeOrigin = (stdParallel1 + stdParallel2) / 2;
            }
            if (latitudeOrigin > 0) {
                minLat = Math.max(-89, latitudeOrigin - MAX_DISTANCE);
                maxLat = 90;
            } else {
                minLat = -90;
                maxLat = Math.min(89, latitudeOrigin + MAX_DISTANCE);
            }

            if (centralMeridian != 0) {
                // we need to divide geometries crossing the central antimeridian in two
                double antiMeridian =
                        centralMeridian > 0 ? centralMeridian - 180 : centralMeridian + 180;
                Polygon beforeAntiMeridian =
                        JTS.toGeometry(new Envelope(-180, antiMeridian - EPS, minLat, maxLat));
                Polygon afterAntiMeridian =
                        JTS.toGeometry(new Envelope(antiMeridian + EPS, 180, minLat, maxLat));
                MultiPolygon mask =
                        beforeAntiMeridian
                                .getFactory()
                                .createMultiPolygon(
                                        new Polygon[] {beforeAntiMeridian, afterAntiMeridian});

                return new ProjectionHandler(sourceCrs, mask, renderingEnvelope);
            } else {
                // for this case we just need to cut on the valid area, which is the whole world
                // minus a tiny area around the dateline
                Envelope validArea = new Envelope(-180 + EPS, 180 - EPS, minLat, maxLat);
                return new ProjectionHandler(sourceCrs, validArea, renderingEnvelope);
            }
        }

        return null;
    }
}