Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.vectorTools.NNSpatialJoin;

import java.util.Properties;

import com.infomatiq.jsi.Point;

import com.infomatiq.jsi.Rectangle;

import com.infomatiq.jsi.rtree.RTree;

import com.vividsolutions.jts.geom.Envelope;

import com.vividsolutions.jts.geom.Geometry;

import es.unex.sextante.core.ITaskMonitor;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.dataObjects.IFeature;

import es.unex.sextante.dataObjects.IFeatureIterator;

import es.unex.sextante.dataObjects.IVectorLayer;

import es.unex.sextante.exceptions.IteratorException;

public class SextanteRTree {

   private final RTree      m_Tree;

   private final int        m_iShapes;

   private final IFeature[] m_Features;

   //TODO:this tree loads all features in memory, so it will not work with large datasets

   public SextanteRTree(final IVectorLayer layer,

                        final ITaskMonitor task) {

      int i;

      task.setProgressText(Sextante.getText("Creating_index"));

      m_Tree = new RTree();

      m_Tree.init(new Properties());

      m_iShapes = layer.getShapesCount();

      m_Features = new IFeature[m_iShapes];

      i = 0;

      final IFeatureIterator iter = layer.iterator();

      while (iter.hasNext() && !task.isCanceled()) {

         try {

            final IFeature feature = iter.next();

            final Geometry geom = feature.getGeometry();

            final Envelope bounds = geom.getEnvelopeInternal();

            final Rectangle rect = new Rectangle((float) bounds.getMinX(), (float) bounds.getMinY(), (float) bounds.getMaxX(),

                     (float) bounds.getMaxY());

            m_Tree.add(rect, new Integer(i));

            m_Features[i] = feature;

            if (i % 50 == 0) {

               task.setProgress(i, m_iShapes);

            }

            i++;

         }

         catch (final IteratorException e1) {

            //skip feature

         }

      }

      iter.close();

   }

   public IFeature getClosestFeature(final double x,

                                     final double y) {

      final Point pt = new Point((float) x, (float) y);

      final int iIdx = m_Tree.nearest(pt);

      return m_Features[iIdx];

   }

}