Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.vectorTools.fixedDistanceBuffer;

import java.util.ArrayList;

import java.util.Stack;

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;

import es.unex.sextante.additionalInfo.AdditionalInfoNumericalValue;

import es.unex.sextante.additionalInfo.AdditionalInfoVectorLayer;

import es.unex.sextante.core.GeoAlgorithm;

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.dataObjects.vectorFilters.BoundingBoxFilter;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

import es.unex.sextante.outputs.OutputVectorLayer;

public class FixedDistanceBufferAlgorithm

         extends

            GeoAlgorithm {

   public static final byte   BUFFER_INSIDE_POLY         = 1;

   public static final byte   BUFFER_OUTSIDE_POLY        = 0;

   public static final byte   BUFFER_INSIDE_OUTSIDE_POLY = 2;

   public static final String RESULT                     = "RESULT";

   public static final String NOTROUNDED                 = "NOTROUNDED";

   public static final String RINGS                      = "RINGS";

   public static final String TYPE                       = "TYPES";

   public static final String LAYER                      = "LAYER";

   public static final String DISTANCE                   = "DISTANCE";

   private IVectorLayer       m_Output;

   private boolean            m_bRounded;

   private int                m_iRings;

   private int                m_iType;

   private int                numProcessed               = 0;

   private double             m_dDistance;

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      final IVectorLayer layerIn = m_Parameters.getParameterValueAsVectorLayer(LAYER);

      if (!m_bIsAutoExtent) {

         layerIn.addFilter(new BoundingBoxFilter(m_AnalysisExtent));

      }

      m_dDistance = m_Parameters.getParameterValueAsDouble(DISTANCE);

      m_bRounded = !m_Parameters.getParameterValueAsBoolean(NOTROUNDED);

      m_iRings = m_Parameters.getParameterValueAsInt(RINGS);

      m_iType = m_Parameters.getParameterValueAsInt(TYPE);

      final int iFieldCount = layerIn.getFieldCount();

      Class types[];

      String[] sFieldNames;

      if (layerIn.getShapeType() != IVectorLayer.SHAPE_TYPE_POLYGON) {

         m_iType = BUFFER_OUTSIDE_POLY;

      }

      if (m_iType == BUFFER_INSIDE_OUTSIDE_POLY) {

         types = new Class[iFieldCount + 3];

         types[0] = Long.class;

         types[1] = Double.class;

         sFieldNames = new String[iFieldCount + 3];

         sFieldNames[0] = "ID";

         sFieldNames[1] = "FROM";

         sFieldNames[1] = "TO";

         for (int i = 0; i < iFieldCount; i++) {

            sFieldNames[i + 3] = layerIn.getFieldName(i);

            types[i + 3] = layerIn.getFieldType(i);

         }

      }

      else {

         types = new Class[iFieldCount + 2];

         types[0] = Long.class;

         types[1] = Double.class;

         sFieldNames = new String[iFieldCount + 2];

         sFieldNames[0] = "ID";

         sFieldNames[1] = "DIST";

         for (int i = 0; i < iFieldCount; i++) {

            sFieldNames[i + 2] = layerIn.getFieldName(i);

            types[i + 2] = layerIn.getFieldType(i);

         }

      }

      m_Output = getNewVectorLayer(RESULT, "Buffer", IVectorLayer.SHAPE_TYPE_POLYGON, types, sFieldNames);

      int i = 0;

      final int iTotal = layerIn.getShapesCount();

      final IFeatureIterator iter = layerIn.iterator();

      while (iter.hasNext() && setProgress(i, iTotal)) {

         final IFeature feature = iter.next();

         computeBuffer(feature.getGeometry(), m_dDistance, feature.getRecord().getValues());

         i++;

      }

      iter.close();

      return !m_Task.isCanceled();

   }

   @Override

   public void defineCharacteristics() {

      //      final String[] sRings = { Integer.toString(1), Integer.toString(2), Integer.toString(3) };

      final String[] sType = { Sextante.getText("Outer_buffer"), Sextante.getText("Inner_buffer"), Sextante.getText("Both"), };

      setName(Sextante.getText("Fixed_distance_buffer"));

      setGroup(Sextante.getText("Buffers"));

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addInputVectorLayer(LAYER, Sextante.getText("Input_layer"), AdditionalInfoVectorLayer.SHAPE_TYPE_ANY, true);

         m_Parameters.addNumericalValue(DISTANCE, Sextante.getText("Distance"),

                  AdditionalInfoNumericalValue.NUMERICAL_VALUE_DOUBLE, 100, 0, Double.MAX_VALUE);

         m_Parameters.addSelection(TYPE, Sextante.getText("Buffer_type"), sType);

         //         m_Parameters.addSelection(RINGS, Sextante.getText("Number_of_concentric_rings"), sRings);

         m_Parameters.addNumericalValue(RINGS, Sextante.getText("Number_of_concentric_rings"),

                  AdditionalInfoNumericalValue.NUMERICAL_VALUE_INTEGER, 100, 1, Integer.MAX_VALUE);

         m_Parameters.addBoolean(NOTROUNDED, Sextante.getText("Do_not_round_resulting_polygons"), false);

         addOutputVectorLayer(RESULT, Sextante.getText("Buffer"), OutputVectorLayer.SHAPE_TYPE_POLYGON);

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   //*********** code adapted from BufferVisitor class, by Alvaro Zabala*******************//

   public void computeBuffer(final Geometry originalGeometry,

                             final double bufferDistance,

                             final Object[] record) {

      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) {

         inputParam = TopologyPreservingSimplifier.simplify(originalGeometry, bufferDistance / 10d);

      }

      int cap = BufferOp.CAP_ROUND;

      if (!m_bRounded) {

         cap = BufferOp.CAP_SQUARE;

      }

      //this two references are necessary to compute radial rings

      Geometry previousExteriorRing = null;

      Geometry previousInteriorRing = null;

      if (m_iType == BUFFER_INSIDE_POLY) {

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

         //most interior buffer

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

            final double distRing = i * bufferDistance;

            final BufferOp bufOp = new BufferOp(inputParam);

            bufOp.setEndCapStyle(cap);

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

            if (verifyNilGeometry(newGeometry)) {

               //we have collapsed original geometry

               return;

            }

            if (previousInteriorRing != null) {

               solution = newGeometry.difference(previousInteriorRing);

            }

            else {

               solution = newGeometry;

            }

            numProcessed++;

            addFeature(solution, distRing, record);

            previousInteriorRing = newGeometry;

         }

      }

      else if (m_iType == BUFFER_OUTSIDE_POLY) {

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

            final double distRing = i * bufferDistance;

            final BufferOp bufOp = new BufferOp(inputParam);

            bufOp.setEndCapStyle(cap);

            final Geometry newGeometry = bufOp.getResultGeometry(distRing);

            if (previousExteriorRing != null) {

               solution = newGeometry.difference(previousExteriorRing);

            }

            else {

               solution = newGeometry;

            }

            numProcessed++;

            addFeature(solution, distRing, record);

            previousExteriorRing = newGeometry;

         }

      }

      else if (m_iType == BUFFER_INSIDE_OUTSIDE_POLY) {

         final GeometryFactory geomFact = new GeometryFactory();

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

            final double distRing = i * bufferDistance;

            final BufferOp bufOp = new BufferOp(inputParam);

            bufOp.setEndCapStyle(cap);

            final Geometry out = bufOp.getResultGeometry(distRing);

            final 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 {

                  final Geometry outRing = out.difference(previousExteriorRing);

                  final Geometry inRing = previousInteriorRing.difference(in);

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

                  solution = geomFact.createGeometryCollection(geomArray);

                  final ArrayList polygons = new ArrayList();

                  final Stack stack = new Stack();

                  stack.push(solution);

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

                     final GeometryCollection geCol = (GeometryCollection) stack.pop();

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

                        final Geometry geometry = geCol.getGeometryN(j);

                        if (geometry instanceof GeometryCollection) {

                           stack.push(geometry);

                        }

                        if (geometry instanceof Polygon) {

                           polygons.add(geometry);

                        }

                     }

                  }

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

                  polygons.toArray(pols);

                  final MultiPolygon newSolution = geomFact.createMultiPolygon(pols);

                  solution = newSolution;

               }

            }

            numProcessed++;

            addFeature(solution, -1 * distRing, distRing, record);

            previousExteriorRing = out;

            if (!collapsedInterior) {

               previousInteriorRing = in;

            }

         }

      }

   }

   protected void addFeature(final Geometry geom,

                             final double distance,

                             final Object[] record) {

      final Object[] values = new Object[2 + record.length];

      values[0] = new Long(numProcessed);

      values[1] = new Double(distance);

      for (int i = 0; i < record.length; i++) {

         values[i + 2] = record[i];

      }

      m_Output.addFeature(geom, values);

   }

   protected void addFeature(final Geometry geom,

                             final double distanceFrom,

                             final double distanceTo,

                             final Object[] record) {

      final Object[] values = new Object[3 + record.length];

      values[0] = new Long(numProcessed);

      values[1] = new Double(distanceFrom);

      values[2] = new Double(distanceTo);

      for (int i = 0; i < record.length; i++) {

         values[i + 3] = record[i];

      }

      m_Output.addFeature(geom, values);

   }

   public boolean verifyNilGeometry(final Geometry newGeometry) {

      if (newGeometry instanceof GeometryCollection) {

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

            //we have collapsed initial geometry

            return true;

         }

      }

      return false;

   }

}

package es.unex.sextante.vectorTools.variableDistanceBuffer;

import java.util.ArrayList;

import java.util.Stack;

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;

import es.unex.sextante.additionalInfo.AdditionalInfoVectorLayer;

import es.unex.sextante.core.GeoAlgorithm;

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.dataObjects.vectorFilters.BoundingBoxFilter;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.OptionalParentParameterException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

import es.unex.sextante.exceptions.UndefinedParentParameterNameException;

import es.unex.sextante.outputs.OutputVectorLayer;

public class VariableDistanceBufferAlgorithm

         extends

            GeoAlgorithm {

   public static final byte   BUFFER_INSIDE_POLY         = 1;

   public static final byte   BUFFER_OUTSIDE_POLY        = 0;

   public static final byte   BUFFER_INSIDE_OUTSIDE_POLY = 2;

   public static final String RESULT                     = "RESULT";

   public static final String NOTROUNDED                 = "NOTROUNDED";

   public static final String RINGS                      = "RINGS";

   public static final String TYPE                       = "TYPES";

   public static final String FIELD                      = "FIELD";

   public static final String LAYER                      = "LAYER";

   private IVectorLayer       m_Output;

   private boolean            m_bRounded;

   private int                m_iRings;

   private int                m_iType;

   private int                numProcessed               = 0;

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      final int iField = m_Parameters.getParameterValueAsInt(FIELD);

      final IVectorLayer layerIn = m_Parameters.getParameterValueAsVectorLayer(LAYER);

      if (!m_bIsAutoExtent) {

         layerIn.addFilter(new BoundingBoxFilter(m_AnalysisExtent));

      }

      m_bRounded = !m_Parameters.getParameterValueAsBoolean(NOTROUNDED);

      m_iRings = m_Parameters.getParameterValueAsInt(RINGS) + 1;

      m_iType = m_Parameters.getParameterValueAsInt(TYPE);

      final int iFieldCount = layerIn.getFieldCount();

      Class types[];

      String[] sFieldNames;

      if (layerIn.getShapeType() != IVectorLayer.SHAPE_TYPE_POLYGON) {

         m_iType = BUFFER_OUTSIDE_POLY;

      }

      if (m_iType == BUFFER_INSIDE_OUTSIDE_POLY) {

         types = new Class[iFieldCount + 3];

         types[0] = Long.class;

         types[1] = Double.class;

         sFieldNames = new String[iFieldCount + 3];

         sFieldNames[0] = "ID";

         sFieldNames[1] = "FROM";

         sFieldNames[1] = "TO";

         for (int i = 0; i < iFieldCount; i++) {

            sFieldNames[i + 3] = layerIn.getFieldName(i);

            types[i + 3] = layerIn.getFieldType(i);

         }

      }

      else {

         types = new Class[iFieldCount + 2];

         types[0] = Long.class;

         types[1] = Double.class;

         sFieldNames = new String[iFieldCount + 2];

         sFieldNames[0] = "ID";

         sFieldNames[1] = "DIST";

         for (int i = 0; i < iFieldCount; i++) {

            sFieldNames[i + 2] = layerIn.getFieldName(i);

            types[i + 2] = layerIn.getFieldType(i);

         }

      }

      m_Output = getNewVectorLayer("RESULT", "Buffer", IVectorLayer.SHAPE_TYPE_POLYGON, types, sFieldNames);

      int i = 0;

      final int iTotal = layerIn.getShapesCount();

      double dDistance;

      final IFeatureIterator iter = layerIn.iterator();

      while (iter.hasNext() && setProgress(i, iTotal)) {

         final IFeature feature = iter.next();

         try {

            final Number num = (Number) feature.getRecord().getValue(iField);

            dDistance = num.doubleValue();

         }

         catch (final Exception e) {

            continue;

         }

         computeBuffer(feature.getGeometry(), dDistance, feature.getRecord().getValues());

         i++;

      }

      iter.close();

      return !m_Task.isCanceled();

   }

   @Override

   public void defineCharacteristics() {

      final String[] sRings = { Integer.toString(1), Integer.toString(2), Integer.toString(3) };

      final String[] sType = { Sextante.getText("Outer_buffer"), Sextante.getText("Inner_buffer"), Sextante.getText("Both"), };

      setName(Sextante.getText("Variable_distance_buffer"));

      setGroup(Sextante.getText("Buffers"));

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addInputVectorLayer(LAYER, Sextante.getText("Input_layer"), AdditionalInfoVectorLayer.SHAPE_TYPE_ANY, true);

         m_Parameters.addTableField(FIELD, Sextante.getText("Distance_field"), "LAYER");

         m_Parameters.addSelection(TYPE, Sextante.getText("Buffer_type"), sType);

         m_Parameters.addSelection(RINGS, Sextante.getText("Number_of_concentric_rings"), sRings);

         m_Parameters.addBoolean(NOTROUNDED, Sextante.getText("Do_not_round_resulting_polygons"), false);

         addOutputVectorLayer(RESULT, Sextante.getText("Buffer"), OutputVectorLayer.SHAPE_TYPE_POLYGON);

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

      catch (final UndefinedParentParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

      catch (final OptionalParentParameterException e) {

         Sextante.addErrorToLog(e);

      }

   }

   //*********** code adapted from BufferVisitor class, by Alvaro Zabala*******************//

   public void computeBuffer(final Geometry originalGeometry,

                             final double bufferDistance,

                             final Object[] record) {

      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) {

         inputParam = TopologyPreservingSimplifier.simplify(originalGeometry, bufferDistance / 10d);

      }

      int cap = BufferOp.CAP_ROUND;

      if (!m_bRounded) {

         cap = BufferOp.CAP_SQUARE;

      }

      //this two references are necessary to compute radial rings

      Geometry previousExteriorRing = null;

      Geometry previousInteriorRing = null;

      if (m_iType == BUFFER_INSIDE_POLY) {

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

         //most interior buffer

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

            final double distRing = i * bufferDistance;

            final BufferOp bufOp = new BufferOp(inputParam);

            bufOp.setEndCapStyle(cap);

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

            if (verifyNilGeometry(newGeometry)) {

               //we have collapsed original geometry

               return;

            }

            if (previousInteriorRing != null) {

               solution = newGeometry.difference(previousInteriorRing);

            }

            else {

               solution = newGeometry;

            }

            numProcessed++;

            addFeature(solution, distRing, record);

            previousInteriorRing = newGeometry;

         }

      }

      else if (m_iType == BUFFER_OUTSIDE_POLY) {

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

            final double distRing = i * bufferDistance;

            final BufferOp bufOp = new BufferOp(inputParam);

            bufOp.setEndCapStyle(cap);

            final Geometry newGeometry = bufOp.getResultGeometry(distRing);

            if (previousExteriorRing != null) {

               solution = newGeometry.difference(previousExteriorRing);

            }

            else {

               solution = newGeometry;

            }

            numProcessed++;

            addFeature(solution, distRing, record);

            previousExteriorRing = newGeometry;

         }

      }

      else if (m_iType == BUFFER_INSIDE_OUTSIDE_POLY) {

         final GeometryFactory geomFact = new GeometryFactory();

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

            final double distRing = i * bufferDistance;

            final BufferOp bufOp = new BufferOp(inputParam);

            bufOp.setEndCapStyle(cap);

            final Geometry out = bufOp.getResultGeometry(distRing);

            final 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 {

                  final Geometry outRing = out.difference(previousExteriorRing);

                  final Geometry inRing = previousInteriorRing.difference(in);

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

                  solution = geomFact.createGeometryCollection(geomArray);

                  final ArrayList polygons = new ArrayList();

                  final Stack stack = new Stack();

                  stack.push(solution);

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

                     final GeometryCollection geCol = (GeometryCollection) stack.pop();

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

                        final Geometry geometry = geCol.getGeometryN(j);

                        if (geometry instanceof GeometryCollection) {

                           stack.push(geometry);

                        }

                        if (geometry instanceof Polygon) {

                           polygons.add(geometry);

                        }

                     }

                  }

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

                  polygons.toArray(pols);

                  final MultiPolygon newSolution = geomFact.createMultiPolygon(pols);

                  solution = newSolution;

               }

            }

            numProcessed++;

            addFeature(solution, -1 * distRing, distRing, record);

            previousExteriorRing = out;

            if (!collapsedInterior) {

               previousInteriorRing = in;

            }

         }

      }

   }

   protected void addFeature(final Geometry geom,

                             final double distance,

                             final Object[] record) {

      final Object[] values = new Object[2 + record.length];

      values[0] = new Long(numProcessed);

      values[1] = new Double(distance);

      for (int i = 0; i < record.length; i++) {

         values[i + 2] = record[i];

      }

      m_Output.addFeature(geom, values);

   }

   protected void addFeature(final Geometry geom,

                             final double distanceFrom,

                             final double distanceTo,

                             final Object[] record) {

      final Object[] values = new Object[3 + record.length];

      values[0] = new Long(numProcessed);

      values[1] = new Double(distanceFrom);

      values[2] = new Double(distanceTo);

      for (int i = 0; i < record.length; i++) {

         values[i + 3] = record[i];

      }

      m_Output.addFeature(geom, values);

   }

   public boolean verifyNilGeometry(final Geometry newGeometry) {

      if (newGeometry instanceof GeometryCollection) {

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

            //we have collapsed initial geometry

            return true;

         }

      }

      return false;

   }

}

package es.unex.sextante.vectorTools.distanceTableBuffer;

import java.util.ArrayList;

import java.util.Arrays;

import com.vividsolutions.jts.geom.Geometry;

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

import es.unex.sextante.additionalInfo.AdditionalInfoVectorLayer;

import es.unex.sextante.core.GeoAlgorithm;

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.dataObjects.vectorFilters.BoundingBoxFilter;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

import es.unex.sextante.outputs.OutputVectorLayer;

import es.unex.sextante.parameters.FixedTableModel;

public class DistanceTableBufferAlgorithm

         extends

            GeoAlgorithm {

   public static final String RESULT          = "RESULT";

   public static final String NOTROUNDED      = "NOTROUNDED";

   public static final String LAYER           = "LAYER";

   public static final String DISTANCES       = "DISTANCES";

   private IVectorLayer       m_Output;

   private boolean            m_bRounded;

   private int                m_iNumProcessed = 0;

   private Double[]           m_Distances;

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      final IVectorLayer layerIn = m_Parameters.getParameterValueAsVectorLayer(LAYER);

      if (!m_bIsAutoExtent) {

         layerIn.addFilter(new BoundingBoxFilter(m_AnalysisExtent));

      }

      final FixedTableModel distances = (FixedTableModel) m_Parameters.getParameterValueAsObject(DISTANCES);

      final ArrayList<Double> distancesList = new ArrayList<Double>();

      for (int i = 0; i < distances.getRowCount(); i++) {

         try {

            final double dDistance = Double.parseDouble(distances.getValueAt(i, 0).toString());

            if (dDistance > 0) {

               distancesList.add(new Double(dDistance));

            }

         }

         catch (final Exception e) {

            //ignore wrong values in table

         }

      }

      if (distancesList.size() == 0) {

         throw new GeoAlgorithmExecutionException(Sextante.getText("No_Elements_In_Distance_List"));

      }

      m_Distances = distancesList.toArray(new Double[0]);

      Arrays.sort(m_Distances);

      m_bRounded = !m_Parameters.getParameterValueAsBoolean(NOTROUNDED);

      final int iFieldCount = layerIn.getFieldCount();

      Class types[];

      String[] sFieldNames;

      types = new Class[iFieldCount + 2];

      types[0] = Integer.class;

      types[1] = Double.class;

      sFieldNames = new String[iFieldCount + 2];

      sFieldNames[0] = "ID";

      sFieldNames[1] = "DIST";

      for (int i = 0; i < iFieldCount; i++) {

         sFieldNames[i + 2] = layerIn.getFieldName(i);

         types[i + 2] = layerIn.getFieldType(i);

      }

      m_Output = getNewVectorLayer(RESULT, "Buffer", IVectorLayer.SHAPE_TYPE_POLYGON, types, sFieldNames);

      int i = 0;

      final int iTotal = layerIn.getShapesCount();

      final IFeatureIterator iter = layerIn.iterator();

      while (iter.hasNext() && setProgress(i, iTotal)) {

         final IFeature feature = iter.next();

         computeBuffer(feature.getGeometry(), feature.getRecord().getValues());

         i++;

      }

      iter.close();

      return !m_Task.isCanceled();

   }

   @Override

   public void defineCharacteristics() {

      setName(Sextante.getText("Multiple_buffer"));

      setGroup(Sextante.getText("Buffers"));

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addInputVectorLayer(LAYER, Sextante.getText("Input_layer"), AdditionalInfoVectorLayer.SHAPE_TYPE_ANY, true);

         m_Parameters.addFixedTable(DISTANCES, Sextante.getText("Distances_table"),

                  new String[] { Sextante.getText("Distance") }, 3, false);

         m_Parameters.addBoolean(NOTROUNDED, Sextante.getText("Do_not_round_resulting_polygons"), false);

         addOutputVectorLayer(RESULT, Sextante.getText("Buffer"), OutputVectorLayer.SHAPE_TYPE_POLYGON);

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   public void computeBuffer(final Geometry originalGeometry,

                             final Object[] record) {

      Geometry solution = null;

      final Geometry inputParam = originalGeometry;

      int cap = BufferOp.CAP_ROUND;

      if (!m_bRounded) {

         cap = BufferOp.CAP_SQUARE;

      }

      Geometry previousExteriorRing = null;

      for (int i = 0; i < m_Distances.length; i++) {

         final double dDistRing = m_Distances[i].doubleValue();

         final BufferOp bufOp = new BufferOp(inputParam);

         bufOp.setEndCapStyle(cap);

         final Geometry newGeometry = bufOp.getResultGeometry(dDistRing);

         if (previousExteriorRing != null) {

            solution = newGeometry.difference(previousExteriorRing);

         }

         else {

            solution = newGeometry;

         }

         m_iNumProcessed++;

         addFeature(solution, dDistRing, record);

         previousExteriorRing = newGeometry;

      }

   }

   protected void addFeature(final Geometry geom,

                             final double dDistance,

                             final Object[] record) {

      final Object[] values = new Object[2 + record.length];

      values[0] = new Long(m_iNumProcessed);

      values[1] = new Double(dDistance);

      for (int i = 0; i < record.length; i++) {

         values[i + 2] = record[i];

      }

      m_Output.addFeature(geom, values);

   }

}