Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.gridTools.mergeGrids;

import java.util.ArrayList;

import es.unex.sextante.additionalInfo.AdditionalInfoMultipleInput;

import es.unex.sextante.core.GeoAlgorithm;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.dataObjects.IRasterLayer;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

public class MergeGridsAlgorithm

         extends

            GeoAlgorithm {

   public static final String METHOD = "METHOD";

   public static final String INPUT  = "INPUT";

   public static final String RESULT = "RESULT";

   @Override

   public void defineCharacteristics() {

      final String[] sMethod = { Sextante.getText("Nearest_neighbour"), Sextante.getText("Bilinear"),

               Sextante.getText("Inverse_distance"), Sextante.getText("Cubic_spline"), Sextante.getText("B-spline") };

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

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

      setUserCanDefineAnalysisExtent(true);

      try {

         m_Parameters.addMultipleInput(INPUT, Sextante.getText("Layers"), AdditionalInfoMultipleInput.DATA_TYPE_RASTER, true);

         m_Parameters.addSelection(METHOD, Sextante.getText("Interpolation_method"), sMethod);

         addOutputRasterLayer(RESULT, Sextante.getText("Merged_grids"));

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      int i;

      int x, y;

      int iMethod;

      int iNX, iNY;

      double dValue, dValueSum;

      double dValidValues;

      IRasterLayer[] window;

      iMethod = m_Parameters.getParameterValueAsInt(METHOD);

      final ArrayList input = m_Parameters.getParameterValueAsArrayList(INPUT);

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

         return false;

      }

      boolean bAddWarning = false;

      int iBands = ((IRasterLayer) input.get(0)).getBandsCount();

      for (i = 0; i < input.size(); i++) {

         final IRasterLayer layer = ((IRasterLayer) input.get(i));

         if (layer.getBandsCount() != iBands) {

            iBands = Math.max(layer.getBandsCount(), iBands);

            bAddWarning = true;

         }

      }

      if (bAddWarning) {

         Sextante.addWarningToLog(Sextante.getText("Layers_to_be_merged_have_different_number_of_bands"));

      }

      final IRasterLayer result = getNewRasterLayer(RESULT, Sextante.getText("Merged_grids"),

               ((IRasterLayer) input.get(0)).getDataType(), iBands);

      result.assignNoData();

      window = new IRasterLayer[input.size()];

      for (i = 0; i < input.size(); i++) {

         window[i] = ((IRasterLayer) input.get(i));

         window[i].setWindowExtent(result.getWindowGridExtent());

         window[i].setInterpolationMethod(iMethod);

      }

      iNX = window[0].getNX();

      iNY = window[0].getNY();

      for (int iBand = 0; iBand < iBands; iBand++) {

         for (y = 0; (y < iNY) && setProgress(y, iNY); y++) {

            for (x = 0; x < iNX; x++) {

               dValueSum = 0;

               dValidValues = 0;

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

                  dValue = window[i].getCellValueAsDouble(x, y, iBand);

                  if (!window[i].isNoDataValue(dValue)) {

                     dValidValues++;

                     dValueSum += dValue;

                  }

               }

               if (dValidValues == 0.0) {

                  result.setNoData(x, y);

               }

               else {

                  result.setCellValue(x, y, iBand, dValueSum / dValidValues);

               }

            }

         }

      }

      return !m_Task.isCanceled();

   }

}