org.geotools.renderer.crs.PolarStereographicHandlerFactory Maven / Gradle / Ivy

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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 java.util.ArrayList;
import java.util.List;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.referencing.CRS;
import org.geotools.referencing.crs.DefaultGeographicCRS;
import org.geotools.referencing.operation.projection.MapProjection;
import org.geotools.referencing.operation.projection.MapProjection.AbstractProvider;
import org.geotools.referencing.operation.projection.PolarStereographic;
import org.geotools.referencing.operation.projection.TransverseMercator;
import org.opengis.parameter.ParameterNotFoundException;
import org.opengis.parameter.ParameterValue;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.TransformException;

/**
 * Returns a {@link ProjectionHandler} for the {@link TransverseMercator} projection that will cut
 * geometries 45° away from the projection central meridian
 *
 * @author Andrea Aime - OpenGeo
 */
public class PolarStereographicHandlerFactory implements ProjectionHandlerFactory {

    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 PolarStereographic)) return null;

        final boolean north;
        // variant B uses standard_parallel
        ParameterValue stdParallel = null;
        try {
            stdParallel =
                    mapProjection
                            .getParameterValues()
                            .parameter(AbstractProvider.STANDARD_PARALLEL_1.getName().getCode());
        } catch (ParameterNotFoundException e) {
            // ignore
        }
        if (stdParallel != null) {
            north = stdParallel.doubleValue() > 0;
        } else {
            // variant A uses latitude of origin
            ParameterValue latOrigin = null;
            try {
                latOrigin =
                        mapProjection
                                .getParameterValues()
                                .parameter(AbstractProvider.LATITUDE_OF_ORIGIN.getName().getCode());
            } catch (ParameterNotFoundException e) {
                // ignore
            }
            if (latOrigin != null) {
                north = latOrigin.doubleValue() > 0;
            } else {
                return null;
            }
        }

        ReferencedEnvelope validArea;
        if (north) {
            validArea =
                    new ReferencedEnvelope(
                            -Integer.MAX_VALUE,
                            Integer.MAX_VALUE,
                            -0,
                            90,
                            DefaultGeographicCRS.WGS84);
        } else {
            validArea =
                    new ReferencedEnvelope(
                            -Integer.MAX_VALUE,
                            Integer.MAX_VALUE,
                            -90,
                            0,
                            DefaultGeographicCRS.WGS84);
        }

        return new ProjectionHandler(sourceCrs, validArea, renderingEnvelope) {
            @Override
            public List getQueryEnvelopes()
                    throws TransformException, FactoryException {
                // check if we are crossing the antimeridian and are fully below the pole,
                // in this case we'd end up reading the full globe when we'd have to just
                // read two portions near the dateline
                List envelopes;
                if (!north
                        && renderingEnvelope.getMaxY() < 0
                        && renderingEnvelope.getMinX() < 0
                        && renderingEnvelope.getMaxX() > 0) {
                    ReferencedEnvelope e1 =
                            new ReferencedEnvelope(
                                    renderingEnvelope.getMinX(),
                                    -1e-6,
                                    renderingEnvelope.getMinY(),
                                    renderingEnvelope.getMaxY(),
                                    renderingEnvelope.getCoordinateReferenceSystem());
                    ReferencedEnvelope e2 =
                            new ReferencedEnvelope(
                                    1e-6,
                                    renderingEnvelope.getMaxX(),
                                    renderingEnvelope.getMinY(),
                                    renderingEnvelope.getMaxY(),
                                    renderingEnvelope.getCoordinateReferenceSystem());
                    envelopes = new ArrayList();
                    envelopes.add(e1);
                    envelopes.add(e2);
                    reprojectEnvelopes(sourceCRS, envelopes);
                } else if (north
                        && renderingEnvelope.getMinY() > 0
                        && renderingEnvelope.getMinX() < 0
                        && renderingEnvelope.getMaxX() > 0) {
                    ReferencedEnvelope e1 =
                            new ReferencedEnvelope(
                                    renderingEnvelope.getMinX(),
                                    -1e-6,
                                    renderingEnvelope.getMinY(),
                                    renderingEnvelope.getMaxY(),
                                    renderingEnvelope.getCoordinateReferenceSystem());
                    ReferencedEnvelope e2 =
                            new ReferencedEnvelope(
                                    1e-6,
                                    renderingEnvelope.getMaxX(),
                                    renderingEnvelope.getMinY(),
                                    renderingEnvelope.getMaxY(),
                                    renderingEnvelope.getCoordinateReferenceSystem());
                    envelopes = new ArrayList();
                    envelopes.add(e1);
                    envelopes.add(e2);
                    reprojectEnvelopes(sourceCRS, envelopes);
                } else {
                    envelopes = super.getQueryEnvelopes();
                }

                return envelopes;
            }
        };
    }
}