| gvSIG desktop 1

/*

 * Created on 05-feb-2006

 *

 * gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/* CVS MESSAGES:

*

* $Id: BufferVisitor.java 6526 2006-07-26 18:06:27Z azabala $

* $Log$

* Revision 1.3  2006-07-26 18:06:27  azabala

* fixed bug when internal buffers collapses geometries

*

* Revision 1.2  2006/07/21 11:04:50  azabala

* Unified createTask and process() methods

*

* Revision 1.1  2006/06/20 18:20:45  azabala

* first version in cvs

*

* Revision 1.2  2006/06/02 18:20:33  azabala

* limpieza de imports

*

* Revision 1.1  2006/05/24 21:14:41  azabala

* primera version en cvs despues de refactoring orientado a crear un framework extensible de geoprocessing

*

* Revision 1.7  2006/05/01 19:18:09  azabala

* revisi?n general del buffer (a?adidos anillos concentricos, buffers interiores y exteriores, etc)

*

* Revision 1.6  2006/04/07 19:00:33  azabala

* *** empty log message ***

*

* Revision 1.5  2006/03/28 16:27:25  azabala

* *** empty log message ***

*

* Revision 1.4  2006/03/07 21:01:33  azabala

* *** empty log message ***

*

* Revision 1.3  2006/03/05 19:56:27  azabala

* *** empty log message ***

*

* Revision 1.1  2006/02/17 16:33:46  azabala

* *** empty log message ***

*

* Revision 1.1  2006/02/09 16:00:36  azabala

* First version in CVS

*

*

*/

package com.iver.cit.gvsig.geoprocess.impl.buffer.fmap;

import java.util.ArrayList;

import java.util.Stack;

import com.hardcode.gdbms.engine.values.Value;

import com.hardcode.gdbms.engine.values.ValueFactory;

import com.iver.cit.gvsig.fmap.core.IFeature;

import com.iver.cit.gvsig.fmap.core.IGeometry;

import com.iver.cit.gvsig.fmap.core.v02.FConverter;

import com.iver.cit.gvsig.fmap.operations.strategies.FeatureVisitor;

import com.iver.cit.gvsig.fmap.operations.strategies.VisitException;

import com.iver.cit.gvsig.geoprocess.core.fmap.FeatureFactory;

import com.iver.cit.gvsig.geoprocess.core.fmap.GeoprocessingResultsProcessor;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.geom.GeometryCollection;

import com.vividsolutions.jts.geom.GeometryFactory;

import com.vividsolutions.jts.geom.MultiPolygon;

import com.vividsolutions.jts.geom.Polygon;

import com.vividsolutions.jts.operation.buffer.BufferOp;

import com.vividsolutions.jts.simplify.TopologyPreservingSimplifier;

/**

 * Abstract base class to those all FeatureVisitor that computes

 * geometry buffers.

 * 

 * 

 * @author azabala

 *

 */

public abstract class BufferVisitor implements FeatureVisitor {

//INTERNAL, EXTERNAL OR BOTH FLAGS        

        /**

         * For polygonal buffers, only compute interior buffers

         */

        public static final byte BUFFER_INSIDE_POLY = 0;

        /**

         * For polygonal buffers, only compute exterior buffers

         * (is the default operation, it applies to any geometry type)

         */

        public static final byte BUFFER_OUTSIDE_POLY = 1;

        /**

         * For polygonal buffers, compute interior and exterior buffers

         */

        public static final byte BUFFER_INSIDE_OUTSIDE_POLY = 2;

//SQUARE OR ROUND CAP FLAGS        

        /**

         * Buffer with square cap

         */

        public static final byte CAP_SQUARE = 0;

        /**

         * Buffer with round cap

         */

        public static final byte CAP_ROUND = 1;

        /**

         * type of buffer to compute (polygons could have the three types,

         * point and lines only outside buffer.

         */

        private byte typeOfBuffer = BUFFER_OUTSIDE_POLY;

        /**

         * To use or not round caps.

         */

        private byte capBuffer = CAP_ROUND;

        /**

         * Number of radial rings buffers

         */

        private int numberOfRadialBuffers = 1;

        /**

         * It process individual JTS buffer results

         */

        protected GeoprocessingResultsProcessor resultsProcessor;

        /**

         * Counter of buffers generated

         */

        protected int numProcessed = 0;

        /**

         * Flag to decide if simplify or not the input

         * geometries. Actually always is true, but 

         * it could change

         */

        private boolean simplifyGeometry = true;

        public void setSimplifyGeometry(boolean simplify){

                this.simplifyGeometry = simplify;

        }

        /**

         * Sets type of buffer flag

         * @param typeOfBuffer

         */

        public void setTypeOfBuffer(byte typeOfBuffer){

                this.typeOfBuffer = typeOfBuffer;

        }

        /**

         * Sets type of cap flag

         * @param typeOfCap

         */

        public void setTypeOfCap(byte typeOfCap){

                capBuffer = typeOfCap;

        }

        /**

         * Sets number of radial rings buffers

         * @param number

         */

        public void setNumberOfRadialBuffers(int number){

                numberOfRadialBuffers = number;

        }

        /**

         * Return number of radial buffers.

         * @return

         */

        public int getNumberOfRadialBuffers(){

                return numberOfRadialBuffers;

        }

        /**

         * Computes a buffer distance for a feature of the buffer layer

         * @param g

         * @param index

         * @return

         */

        public abstract double getBufferDistance(IGeometry g, int index);

        /**

         * Generates a buffer geometry for the visited IGeometry

         */

        public void visit(IGeometry g, int index) throws VisitException {

                if(g == null)

                        return;

                Geometry jtsGeo = g.toJTSGeometry();

                double bufferDistance = getBufferDistance(g, index);

                computeBuffer(jtsGeo, bufferDistance, index);

        }

        /**

         * Verifys if a geometry buffer is null.

         * It is useful when you're working with internal buffers. If the internal

         * buffer distance is greater than the geometry radius, the buffer result

         * will be null.

         * 

         * @param newGeometry

         * @return

         */

        public boolean verifyNilGeometry(Geometry newGeometry){

                if(newGeometry instanceof GeometryCollection){

                        if(((GeometryCollection)newGeometry).getNumGeometries() == 0){

                                //we have collapsed initial geometry

                                return true;

                        }

                }

                return false;

        }

        /**

         * 

         * Compute a buffer (in function of the params) of

         * the original geometry

         * 

         * @param originalGeometry

         * @param bufferDistance

         * @return

         * 

         */

        public void computeBuffer(Geometry originalGeometry, double bufferDistance, int index){

                Geometry solution = null;

                Geometry inputParam = originalGeometry;

                /*

                 * When we try to apply large buffer distances, we could get OutOfMemoryError

                 * exceptions. Explanation in

                 * http://lists.jump-project.org/pipermail/jts-devel/2005-February/000991.html

                 * http://lists.jump-project.org/pipermail/jts-devel/2005-September/001292.html

                 * This problems hasnt been resolved in JTS 1.7.

                 */

                if(originalGeometry.getDimension() != 0 && simplifyGeometry){

                        //ver si 1/10 de la distancia de buffer

                        //es un % de simplificaci?n adecuado

                        inputParam = 

                                TopologyPreservingSimplifier.

                                        simplify(originalGeometry, 

                                                        bufferDistance / 10d);

                }

                int cap = BufferOp.CAP_ROUND;

                if(capBuffer == CAP_SQUARE){

                        cap = BufferOp.CAP_SQUARE;

                }

                //this two references are necessary to compute radial rings

                Geometry previousExteriorRing = null;

                Geometry previousInteriorRing = null;

                //TODO Ya se que no est? muy refinado estos if-else, pero

                //en principio he priorizado que funcione 

                if(typeOfBuffer == BUFFER_INSIDE_POLY){

                                //if we have radial internal buffers, we start by

                                //most interior buffer

                                for(int i = numberOfRadialBuffers; i >= 1; i--){

                                        double distRing = i * bufferDistance;

                                        BufferOp bufOp = new BufferOp(inputParam);

                                        bufOp.setEndCapStyle(cap);

                                        Geometry newGeometry = bufOp.getResultGeometry(-1 * distRing);

//                                        Geometry newGeometry = BufferOp.bufferOp(inputParam, -1 * distRing, cap);

                                        if(verifyNilGeometry(newGeometry)){

                                                //we have collapsed original geometry

                                                return;

                                        }

                                        if(previousInteriorRing != null){

                                                solution = newGeometry.difference(previousInteriorRing);

                                        }else{

                                                solution = newGeometry;

                                        }

                                        numProcessed++;

                                        IFeature feature = createFeature(solution, distRing);

                                        resultsProcessor.processFeature(feature);

                                        previousInteriorRing = newGeometry;

                                }

                }else if(typeOfBuffer == BUFFER_OUTSIDE_POLY){

                        for(int i = 1; i <= numberOfRadialBuffers; i++){

                                double distRing = i * bufferDistance;

                                BufferOp bufOp = new BufferOp(inputParam);

                                bufOp.setEndCapStyle(cap);

                                Geometry newGeometry = bufOp.getResultGeometry(distRing);

//                                Geometry newGeometry = BufferOp.bufferOp(inputParam, distRing, cap);

                                if(previousExteriorRing != null){

                                        solution = newGeometry.difference(previousExteriorRing);

                                }else{

                                        solution = newGeometry;

                                }

                                numProcessed++;

                                IFeature feature = createFeature(solution, distRing);

                                resultsProcessor.processFeature(feature);

                                previousExteriorRing = newGeometry;

                        }

                }else if(typeOfBuffer == BUFFER_INSIDE_OUTSIDE_POLY){

                        GeometryFactory geomFact = new GeometryFactory();

                        for(int i = 1; i <= numberOfRadialBuffers; i++){

                                double distRing = i * bufferDistance;

                                BufferOp bufOp = new BufferOp(inputParam);

                                bufOp.setEndCapStyle(cap);

                                Geometry out = bufOp.getResultGeometry(distRing);

                                Geometry in = bufOp.getResultGeometry(-1 * distRing);

                                boolean collapsedInterior = verifyNilGeometry(in);

                                if(previousExteriorRing == null || previousInteriorRing == null){

                                        if(collapsedInterior)

                                                solution = out;

                                        else

                                                solution = out.difference(in);

                                }else{

                                        if(collapsedInterior){

                                                solution = out.difference(previousExteriorRing);

                                        }else{

                                                Geometry outRing = out.difference(previousExteriorRing);

                                                Geometry inRing = previousInteriorRing.difference(in);

                                                Geometry[] geomArray = new Geometry[]{outRing, inRing};

                                                solution = geomFact.createGeometryCollection(geomArray);

                                                //FMap doesnt work with GeometryCollection, so we try

                                                //to pass to a MultiPolygon.

                                                ArrayList polygons = new ArrayList();

                                                Stack stack = new Stack();

                                                stack.push(solution);

                                                while(stack.size() != 0){

                                                        GeometryCollection geCol = 

                                                                (GeometryCollection) stack.pop(); 

                                                        for(int j = 0; j < geCol.getNumGeometries(); j++){

                                                                Geometry geometry = geCol.getGeometryN(j);

                                                                if(geometry instanceof GeometryCollection)

                                                                        stack.push(geometry);

                                                                if(geometry instanceof Polygon)

                                                                        polygons.add(geometry);

                                                        }//for

                                                }//while

                                                Polygon[] pols = new Polygon[polygons.size()];

                                                polygons.toArray(pols);

                                                MultiPolygon newSolution = geomFact.createMultiPolygon(pols);

                                                solution = newSolution;

                                        }

                                }//else

                                numProcessed++;

                                IFeature feature = createFeature(solution, -1 * distRing, distRing);

                                resultsProcessor.processFeature(feature);

                                previousExteriorRing = out;

                                if(!collapsedInterior)

                                        previousInteriorRing = in;

                        }//for

                }//else

        }

        /**

         * Creates a feature for a simple buffer process for polygons

         * (the result feature will have a field with the buffer distance)

         * @param jtsGeo

         * @param distance

         * @return

         */

        protected IFeature createFeature(Geometry jtsGeo, double distance){

                IGeometry iGeo = FConverter.jts_to_igeometry(jtsGeo);

                Value[] values = new Value[2];

                values[0] = ValueFactory.createValue(numProcessed);

                values[1] = ValueFactory.createValue(distance);

                return FeatureFactory.createFeature(values, iGeo);

        }

        /**

         * Creates a feature for a external and internal buffer process for polygons

         * (the result feature will have a field with the external buffer distance,

         * and a field with the internal buffer distance)

         * @param jtsGeo

         * @param distance

         * @return

         */

        protected IFeature createFeature(Geometry jtsGeo, double distanceFrom, double distanceTo){

                IGeometry iGeo = FConverter.jts_to_igeometry(jtsGeo);

                Value[] values = new Value[3];

                values[0] = ValueFactory.createValue(numProcessed);

                values[1] = ValueFactory.createValue(distanceFrom);

                values[2] = ValueFactory.createValue(distanceTo);

                return FeatureFactory.createFeature(values, iGeo);

        }

        /**

         * Sets BufferResultProcessor, class that has the responsability

         * of process individual JTS buffered geometries (save it, 

         * to cache it, etc)

         * @param processor

         */

        public void setBufferProcessor(GeoprocessingResultsProcessor processor) {

                this.resultsProcessor = processor;

        }

        /**

         * Returns buffer processor

         * @return

         */

        public GeoprocessingResultsProcessor getBufferProcessor() {

                return resultsProcessor;

        }

        /**

         * Returns type of buffer flag (internal, external, both)

         * @return

         */

        public byte getTypeOfBuffer() {

                return typeOfBuffer;

        }

}