| gvSIG desktop 1

/*

 * Created on 11-sep-2006 by azabala

 *

 */

package com.iver.cit.gvsig.fmap.topology.geomgraph;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.Comparator;

import java.util.Iterator;

import java.util.List;

import com.vividsolutions.jts.geom.Coordinate;

import com.vividsolutions.jts.geom.Envelope;

import com.vividsolutions.jts.geom.Location;

import com.vividsolutions.jts.geomgraph.EdgeEnd;

import com.vividsolutions.jts.geomgraph.Node;

import com.vividsolutions.jts.geomgraph.NodeFactory;

import com.vividsolutions.jts.geomgraph.NodeMap;

import com.vividsolutions.jts.index.quadtree.Quadtree;

/**

 * Repository of nodes of a PlanarGraph that applies a snap 

 * tolerance.

 * 

 * If we ask for a node, and it founds a node in the tolerance distance

 * it returns the found node.

 * 

 * 

 * 

 * @author alzabord

 */

public class SnappingNodeMap extends NodeMap {

        private Quadtree spatialIndex;

        private double snapTolerance;

        private NodeFactory nodeFact;

        public SnappingNodeMap(NodeFactory arg0, double snapTolerance) {

                super(arg0);

                this.snapTolerance = snapTolerance;

                spatialIndex = new Quadtree();

        }

        class MinDistCoordComparator implements Comparator{

                Coordinate coord;

                 MinDistCoordComparator(Coordinate coord){

                        this.coord = coord;

                }

                public int compare(Object arg0, Object arg1) {

                        Coordinate c1 = (Coordinate) arg0;

                        Coordinate c2 = (Coordinate) arg1;

                        double d1 = c1.distance(coord);

                        double d2 = c2.distance(coord);

                        if (d1 < d2) return 1;

                        if (d1 > d2) return -1;

                        else return 0;

                }

        }

        private Envelope getQueryRect(Coordinate coord){

                double xmin = coord.x - snapTolerance;

                  double ymin = coord.x + snapTolerance;

                  double xmax = coord.y - snapTolerance;

                  double ymax = coord.y + snapTolerance;

                  Envelope queryRect = new Envelope(xmin, xmax, ymin, ymax);

                  return queryRect;

        }

          public Node addNode(final Coordinate coord)

          {

                  Envelope queryRect = getQueryRect(coord);

                  List nodes = spatialIndex.query(getQueryRect(coord));

                  Collections.sort(nodes, new MinDistCoordComparator(coord));          

                  Node candidate = (Node) nodes.get(0);

                  if(candidate == null)

                  {

              candidate = nodeFact.createNode(coord);

              this.spatialIndex.insert(queryRect, candidate);

            }

                  return candidate;  

          }

//FIXME: REVISAR SI HABR?A QUE HACER UN MERGE LABEL ARRIBA O AQU?

          public Node addNode(Node n)

          {

            Node node = addNode(n.getCoordinate());

            node.mergeLabel(n);

            return node;

          }

          /**

           * Adds a node for the start point of this EdgeEnd

           * (if one does not already exist in this map).

           * Adds the EdgeEnd to the (possibly new) node.

           */

          public void add(EdgeEnd e)

          {

            Coordinate p = e.getCoordinate();

            Node n = addNode(p);

            n.add(e);

          }

          /**

           * @return the node if found; null otherwise

           */

          public Node find(Coordinate coord)  { 

                Envelope queryRect = getQueryRect(coord);

                  List nodes = spatialIndex.query(getQueryRect(coord));

                  Collections.sort(nodes, new MinDistCoordComparator(coord));          

                  Node candidate = (Node) nodes.get(0);

                  return candidate;  

          }

          public Iterator iterator()

          {

            return spatialIndex.queryAll().iterator();

          }

          public Collection values()

          {

            return spatialIndex.queryAll();

          }

          public Collection getBoundaryNodes(int geomIndex)

          {

            Collection bdyNodes = new ArrayList();

            for (Iterator i = iterator(); i.hasNext(); ) {

              Node node = (Node) i.next();

              if (node.getLabel().getLocation(geomIndex) == Location.BOUNDARY)

                bdyNodes.add(node);

            }

            return bdyNodes;

          }

}