view gnv-artifacts/src/main/java/de/intevation/gnv/raster/JTSMultiLineStringProducer.java @ 756:1614b27dcbfa

Added Support of Layers which are Joined from two Tables. gnv-artifacts/trunk@804 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author Tim Englich <tim.englich@intevation.de>
date Fri, 19 Mar 2010 12:12:10 +0000
parents 70adafe2b9d5
children b1f5f2a8840f
line wrap: on
line source
package de.intevation.gnv.raster;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.MultiLineString;
import com.vividsolutions.jts.geom.Polygon;
import com.vividsolutions.jts.geom.TopologyException;

import de.intevation.gnv.math.IJKey;

import de.intevation.gnv.raster.Vectorizer.Edge;

import de.intevation.gnv.utils.Pair;

import gnu.trove.TIntObjectHashMap;

import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;
/**
 * @author Sascha L. Teichmann (sascha.teichmann@intevation.de)
 */
public class JTSMultiLineStringProducer
extends      IsoProducer
{
    private static Logger log = Logger.getLogger(
        JTSMultiLineStringProducer.class);

    protected GeometryFactory geometryFactory;

    protected Polygon clip;

    public JTSMultiLineStringProducer(
        Polygon clip,
        double minX, double minY,
        double maxX, double maxY
    ) {
        this(
            clip,
            // XXX: Geotools crashes if only using a 2d packed data format!
            JTSMultiPolygonProducer.createDefaultGeometryFactory(3),
            minX, minY,
            maxX, maxY);
    }

    public JTSMultiLineStringProducer(
        Polygon clip,
        GeometryFactory geometryFactory,
        double minX, double minY,
        double maxX, double maxY
    ) {
        super(minX, minY, maxX, maxY);
        this.clip = clip;
        this.geometryFactory = geometryFactory;
    }

    protected void clipLineString(
        LineString            lineString,
        ArrayList<LineString> lineStrings
    ) {
        if (clip == null) {
            lineStrings.add(lineString);
            return;
        }

        if (!lineString.intersects(clip)) {
            return;
        }

        try {
            Geometry result = lineString.intersection(clip);

            if (result instanceof LineString) {
                lineStrings.add((LineString)result);
            }
            else if (result instanceof MultiLineString) {
                MultiLineString mls = (MultiLineString)result;
                for (int i = 0, N = mls.getNumGeometries(); i < N; ++i) {
                    Geometry g = mls.getGeometryN(i);
                    if (g instanceof LineString) {
                        lineStrings.add((LineString)g);
                    }
                    else {
                        log.warn("cannot handle geometry " + g.getClass());
                    }
                }
            }
            else {
                log.warn("cannot handle " + result.getClass());
            }
        }
        catch (TopologyException te) {
            log.error(te.getLocalizedMessage(), te);
            lineStrings.add(lineString);
        }
    }

    public List<Pair<Object, MultiLineString>> getMultiLineStrings(
        AttributeGenerator attributeGenerator
    ) {
        ArrayList<Pair<Object, MultiLineString>> multiLineStrings =
            new ArrayList<Pair<Object, MultiLineString>>();

        double b1 = minX;
        double m1 = width != 1
            ? (maxX - minX)/(width-1)
            : 0d;

         double b2 = minY;
         double m2 = height != 1
            ? (maxY - minY)/(height-1)
            : 0d;

        ArrayList<Coordinate> coordinates = new ArrayList<Coordinate>();

        for (IJKey key: joinPairs()) {
            ArrayList<LineString> lineStrings = new ArrayList<LineString>();

            // process complete
            ArrayList<Edge> completeList = complete.get(key);
            if (completeList != null) {
                for (Edge head: completeList) {
                    Edge current = head;
                    do {
                        coordinates.add(new Coordinate(
                            m1*(current.a % width) + b1,
                            m2*(current.a / width) + b2));
                    }
                    while ((current = current.next) != head);
                    // add head again to close shape
                    coordinates.add(new Coordinate(
                        m1*(head.a % width) + b1,
                        m2*(head.a / width) + b2));

                    clipLineString(
                        geometryFactory.createLineString(
                            coordinates.toArray(
                                new Coordinate[coordinates.size()])),
                        lineStrings);

                    coordinates.clear();
                }
            }

            // process open
            TIntObjectHashMap map = commonOpen.get(key);

            if (map != null) {
                for (Edge head: headList(map)) {

                    head = Vectorizer.simplify(head, width);
                    Edge current = head, last = head;
                    do {
                        coordinates.add(new Coordinate(
                            m1*(current.a % width) + b1,
                            m2*(current.a / width) + b2));
                        last = current;
                    }
                    while ((current = current.next) != null);
                    // add b from tail
                    coordinates.add(new Coordinate(
                        m1*(last.b % width) + b1,
                        m2*(last.b / width) + b2));

                    clipLineString(
                        geometryFactory.createLineString(
                            coordinates.toArray(
                                new Coordinate[coordinates.size()])),
                        lineStrings);

                    coordinates.clear();
                } // for all in common open
            } // if map defined for key

			if (!lineStrings.isEmpty()) {
                MultiLineString multiLineString =
                    geometryFactory.createMultiLineString(
                        lineStrings.toArray(
                            new LineString[lineStrings.size()]));
                lineStrings.clear();
                Object attribute = attributeGenerator != null
                    ? attributeGenerator.generateAttribute(key.i, key.j)
                    : key;
                multiLineStrings.add(new Pair<Object, MultiLineString>(
                    attribute,
                    multiLineString));
			}
        } // for all pairs

        return multiLineStrings;
    }
}
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