Application: gvSIG desktop » gvSIG tools: Vector editing

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright ? 2007-2015 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 2

 * 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.vectorediting.lib.prov.trimline.operation;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.dal.feature.Feature;

import org.gvsig.fmap.dal.feature.FeatureSelection;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.GeometryLocator;

import org.gvsig.fmap.geom.GeometryManager;

import org.gvsig.fmap.geom.aggregate.MultiCurve;

import org.gvsig.fmap.geom.exception.CreateGeometryException;

import org.gvsig.fmap.geom.operation.GeometryOperationException;

import org.gvsig.fmap.geom.operation.GeometryOperationNotSupportedException;

import org.gvsig.fmap.geom.primitive.Curve;

import org.gvsig.fmap.geom.primitive.Line;

import org.gvsig.fmap.geom.primitive.Point;

import org.gvsig.tools.dispose.DisposableIterator;

import org.gvsig.tools.locator.LocatorException;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 * Operation to trim curves.

 * 

 * @author llmarques

 */

public class CurveTrimLineOperation implements TrimLineOperation {

    private static final Logger LOGGER = LoggerFactory

        .getLogger(CurveTrimLineOperation.class);

    /*

     * Strategy:

     * 

     * 1. Get arc segments between curve and shears.

     * 2. Determinate what segment of curve must be deleted

     * 3. Rebuild curve taking into account the segment that must be deleted

     */

    @Override

    public MultiCurve trimLine(Curve curveToTrim, Point shearingPoint,

        FeatureSelection shears)

        throws GeometryOperationNotSupportedException,

        GeometryOperationException, DataException, CreateGeometryException,

        LocatorException {

        GeometryManager geometryManager = GeometryLocator.getGeometryManager();

        int subType = curveToTrim.getGeometryType().getSubType();

        DisposableIterator it = shears.fastIterator();

        MultiCurve segmentedLine = geometryManager.createMultiCurve(subType);

        segmentedLine.addCurve(curveToTrim);

        while (it.hasNext()) {

            Feature feature = (Feature) it.next();

            Geometry geometry = feature.getDefaultGeometry();

            Geometry tmpDifference = segmentedLine.difference(geometry);

            if (tmpDifference instanceof MultiCurve) {

                segmentedLine = (MultiCurve) tmpDifference;

            } else if(tmpDifference instanceof Curve) {

                // Sometimes line to split and splitter are so close ( distance

                // between geometries < 0.00000000001 ). In this cases, we try

                // to do an enhance difference.

                // If the result is instance of Curve, it is considered that

                // lines don't intersect.

                // If the result is instance of Multicurve, lines are so close

                // and it is considered that lines intersect.

                Geometry enchancedGeometry = enhancedDifference(geometry, (Curve) tmpDifference);

                if(enchancedGeometry instanceof MultiCurve){

                    segmentedLine = (MultiCurve) enchancedGeometry;

                } 

            }

        }

        if (segmentedLine.getPrimitivesNumber() == 1) {

            return segmentedLine;

        }

        int index = 0;

        Curve curve;

        double minDistance = Double.POSITIVE_INFINITY;

        for (int i = 0; i < segmentedLine.getPrimitivesNumber(); i++) {

            curve = segmentedLine.getCurveAt(i);

            double distance = curve.distance(shearingPoint);

            if (distance < minDistance) {

                index = i;

                minDistance = distance;

            }

        }

        MultiCurve trimmedCurve = geometryManager.createMultiCurve(subType);

        Curve tmpCurve = null;

        for (int i = 0; i < segmentedLine.getPrimitivesNumber(); i++) {

            if (i == index) {

                if (tmpCurve != null) {

                    trimmedCurve.addCurve(tmpCurve);

                    tmpCurve = null;

                }

                continue;

            }

            if (tmpCurve != null) {

                tmpCurve = union(tmpCurve, segmentedLine.getCurveAt(i));

            } else {

                tmpCurve = segmentedLine.getCurveAt(i);

            }

        }

        if (tmpCurve != null) {

            trimmedCurve.addCurve(tmpCurve);

        }

        return trimmedCurve;

    }

    private Curve union(Curve firstCurve, Curve secondCurve)

        throws CreateGeometryException, LocatorException,

        GeometryOperationNotSupportedException, GeometryOperationException {

        int subtype1 = firstCurve.getGeometryType().getSubType();

        int subtype2 = secondCurve.getGeometryType().getSubType();

        if (subtype1 == subtype2) {

            Curve union =

                GeometryLocator.getGeometryManager().createLine(subtype1);

            for (int i = 0; i < firstCurve.getNumVertices() - 1; i++) {

                union.addVertex(firstCurve.getVertex(i));

            }

            Point lastVertex =

                firstCurve.getVertex(firstCurve.getNumVertices() - 2);

            for (int i = 0; i < secondCurve.getNumVertices(); i++) {

                if (i == 0) {

                    Line tmpLine =

                        GeometryLocator.getGeometryManager().createLine(

                            subtype1);

                    tmpLine.setPoints(lastVertex, secondCurve.getVertex(1));

                    if (TrimLineOperationUtils.intersects(tmpLine,

                        secondCurve.getVertex(0))) {

                        continue;

                    }

                }

                union.addVertex(secondCurve.getVertex(i));

            }

            return union;

        }

        return null;

    }

    private Geometry enhancedDifference(Geometry splitter, Curve curve)

        throws GeometryOperationNotSupportedException,

        GeometryOperationException {

        Geometry snapTo = curve.snapTo(splitter, TrimLineOperationUtils.SNAP_TOLERANCE);

        return snapTo.difference(splitter);

    }

    /*

     * Strategy:

     * 

     * 1. Get line segments between curve and shears

     * 2. Determinate what segment of curve must be deleted

     * 3. Rebuild curve taking into account the segment that must be deleted

     */

    @Override

    public MultiCurve trimLine(Curve curveToTrim, Point shearingPoint,

        Geometry shears)

        throws GeometryOperationNotSupportedException,

        GeometryOperationException, DataException, CreateGeometryException,

        LocatorException {

        GeometryManager geometryManager = GeometryLocator.getGeometryManager();

        int subType = curveToTrim.getGeometryType().getSubType();

        MultiCurve segmentedLine = geometryManager.createMultiCurve(subType);

        segmentedLine.addCurve(curveToTrim);

        Geometry tmpDifference = segmentedLine.difference(shears);

        if (tmpDifference instanceof MultiCurve) {

            segmentedLine = (MultiCurve) tmpDifference;

        } else if(tmpDifference instanceof Curve) {

            // Sometimes line to split and splitter are so close ( distance

            // between geometries < 0.00000000001 ). In this cases, we try

            // to do an enhance difference.

            // If the result is instance of Curve, it is considered that

            // lines don't intersect.

            // If the result is instance of Multicurve, lines are so close

            // and it is considered that lines intersect.

            Geometry enchancedGeometry = enhancedDifference(shears, (Curve) tmpDifference);

            if(enchancedGeometry instanceof MultiCurve){

                segmentedLine = (MultiCurve) enchancedGeometry;

            } 

        }

        if (segmentedLine.getPrimitivesNumber() == 1) {

            return segmentedLine;

        }

        double side = TrimLineOperationUtils.getSide(shears, shearingPoint);

        int index = -1;

        if(!Double.isNaN(side)){

            Curve curve;

            double minDistance = Double.POSITIVE_INFINITY;

            for (int i = 0; i < segmentedLine.getPrimitivesNumber(); i++) {

                curve = segmentedLine.getCurveAt(i);

                double distance = curve.distance(shearingPoint);

                if (distance < minDistance) {

                    Double segmentSide = TrimLineOperationUtils.getSide(shears, curve);

                    if(segmentSide == side){

                        index = i;

                        minDistance = distance;

                    }

                }

            }

        }

        MultiCurve trimmedCurve = geometryManager.createMultiCurve(subType);

        Curve tmpCurve = null;

        for (int i = 0; i < segmentedLine.getPrimitivesNumber(); i++) {

            if (i == index) {

                if (tmpCurve != null) {

                    trimmedCurve.addCurve(tmpCurve);

                    tmpCurve = null;

                }

                continue;

            }

            if (tmpCurve != null) {

                tmpCurve = union(tmpCurve, segmentedLine.getCurveAt(i));

            } else {

                tmpCurve = segmentedLine.getCurveAt(i);

            }

        }

        if (tmpCurve != null) {

            trimmedCurve.addCurve(tmpCurve);

        }

        return trimmedCurve;

    }

}