Esempio n. 1
0
// Slot called when the menu item is triggered
// If you created more menu items / toolbar buttons in initiGui, you should
// create a separate handler for each action - this single run() method will
// not be enough
void Heatmap::run()
{
  HeatmapGui d( mQGisIface->mainWindow(), QgisGui::ModalDialogFlags, &mSessionSettings );

  if ( d.exec() == QDialog::Accepted )
  {
    // everything runs here

    // Get the required data from the dialog
    QgsRectangle myBBox = d.bbox();
    int columns = d.columns();
    int rows = d.rows();
    double cellsize = d.cellSizeX(); // or d.cellSizeY();  both have the same value
    mDecay = d.decayRatio();
    int kernelShape = d.kernelShape();

    // Start working on the input vector
    QgsVectorLayer* inputLayer = d.inputVectorLayer();

    // Getting the rasterdataset in place
    GDALAllRegister();

    GDALDataset *emptyDataset;
    GDALDriver *myDriver;

    myDriver = GetGDALDriverManager()->GetDriverByName( d.outputFormat().toUtf8() );
    if ( myDriver == NULL )
    {
      QMessageBox::information( 0, tr( "GDAL driver error" ), tr( "Cannot open the driver for the specified format" ) );
      return;
    }

    double geoTransform[6] = { myBBox.xMinimum(), cellsize, 0, myBBox.yMinimum(), 0, cellsize };
    emptyDataset = myDriver->Create( d.outputFilename().toUtf8(), columns, rows, 1, GDT_Float32, NULL );
    emptyDataset->SetGeoTransform( geoTransform );
    // Set the projection on the raster destination to match the input layer
    emptyDataset->SetProjection( inputLayer->crs().toWkt().toLocal8Bit().data() );

    GDALRasterBand *poBand;
    poBand = emptyDataset->GetRasterBand( 1 );
    poBand->SetNoDataValue( NO_DATA );

    float* line = ( float * ) CPLMalloc( sizeof( float ) * columns );
    for ( int i = 0; i < columns ; i++ )
    {
      line[i] = NO_DATA;
    }
    // Write the empty raster
    for ( int i = 0; i < rows ; i++ )
    {
      poBand->RasterIO( GF_Write, 0, i, columns, 1, line, columns, 1, GDT_Float32, 0, 0 );
    }

    CPLFree( line );
    //close the dataset
    GDALClose(( GDALDatasetH ) emptyDataset );

    // open the raster in GA_Update mode
    GDALDataset *heatmapDS;
    heatmapDS = ( GDALDataset * ) GDALOpen( d.outputFilename().toUtf8(), GA_Update );
    if ( !heatmapDS )
    {
      QMessageBox::information( 0, tr( "Raster update error" ), tr( "Could not open the created raster for updating. The heatmap was not generated." ) );
      return;
    }
    poBand = heatmapDS->GetRasterBand( 1 );

    QgsAttributeList myAttrList;
    int rField = 0;
    int wField = 0;

    // Handle different radius options
    double radius;
    double radiusToMapUnits = 1;
    int myBuffer = 0;
    if ( d.variableRadius() )
    {
      rField = d.radiusField();
      myAttrList.append( rField );
      QgsDebugMsg( QString( "Radius Field index received: %1" ).arg( rField ) );

      // If not using map units, then calculate a conversion factor to convert the radii to map units
      if ( d.radiusUnit() == HeatmapGui::Meters )
      {
        radiusToMapUnits = mapUnitsOf( 1, inputLayer->crs() );
      }
    }
    else
    {
      radius = d.radius(); // radius returned by d.radius() is already in map units
      myBuffer = bufferSize( radius, cellsize );
    }

    if ( d.weighted() )
    {
      wField = d.weightField();
      myAttrList.append( wField );
    }

    // This might have attributes or mightnot have attibutes at all
    // based on the variableRadius() and weighted()
    QgsFeatureIterator fit = inputLayer->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( myAttrList ) );
    int totalFeatures = inputLayer->featureCount();
    int counter = 0;

    QProgressDialog p( tr( "Creating heatmap" ), tr( "Abort" ), 0, totalFeatures, mQGisIface->mainWindow() );
    p.setWindowModality( Qt::ApplicationModal );
    p.show();

    QgsFeature myFeature;

    while ( fit.nextFeature( myFeature ) )
    {
      counter++;
      p.setValue( counter );
      QApplication::processEvents();
      if ( p.wasCanceled() )
      {
        QMessageBox::information( 0, tr( "Heatmap generation aborted" ), tr( "QGIS will now load the partially-computed raster." ) );
        break;
      }

      QgsGeometry* myPointGeometry;
      myPointGeometry = myFeature.geometry();
      // convert the geometry to point
      QgsPoint myPoint;
      myPoint = myPointGeometry->asPoint();
      // avoiding any empty points or out of extent points
      if (( myPoint.x() < myBBox.xMinimum() ) || ( myPoint.y() < myBBox.yMinimum() )
          || ( myPoint.x() > myBBox.xMaximum() ) || ( myPoint.y() > myBBox.yMaximum() ) )
      {
        continue;
      }

      // If radius is variable then fetch it and calculate new pixel buffer size
      if ( d.variableRadius() )
      {
        radius = myFeature.attribute( rField ).toDouble() * radiusToMapUnits;
        myBuffer = bufferSize( radius, cellsize );
      }

      int blockSize = 2 * myBuffer + 1; //Block SIDE would be more appropriate
      // calculate the pixel position
      unsigned int xPosition, yPosition;
      xPosition = (( myPoint.x() - myBBox.xMinimum() ) / cellsize ) - myBuffer;
      yPosition = (( myPoint.y() - myBBox.yMinimum() ) / cellsize ) - myBuffer;

      // get the data
      float *dataBuffer = ( float * ) CPLMalloc( sizeof( float ) * blockSize * blockSize );
      poBand->RasterIO( GF_Read, xPosition, yPosition, blockSize, blockSize,
                        dataBuffer, blockSize, blockSize, GDT_Float32, 0, 0 );

      double weight = 1.0;
      if ( d.weighted() )
      {
        weight = myFeature.attribute( wField ).toDouble();
      }

      for ( int xp = 0; xp <= myBuffer; xp++ )
      {
        for ( int yp = 0; yp <= myBuffer; yp++ )
        {
          double distance = sqrt( pow( xp, 2.0 ) + pow( yp, 2.0 ) );

          // is pixel outside search bandwidth of feature?
          if ( distance > myBuffer )
          {
            continue;
          }

          double pixelValue = weight * calculateKernelValue( distance, myBuffer, kernelShape );

          // clearing anamolies along the axes
          if ( xp == 0 && yp == 0 )
          {
            pixelValue /= 4;
          }
          else if ( xp == 0 || yp == 0 )
          {
            pixelValue /= 2;
          }

          int pos[4];
          pos[0] = ( myBuffer + xp ) * blockSize + ( myBuffer + yp );
          pos[1] = ( myBuffer + xp ) * blockSize + ( myBuffer - yp );
          pos[2] = ( myBuffer - xp ) * blockSize + ( myBuffer + yp );
          pos[3] = ( myBuffer - xp ) * blockSize + ( myBuffer - yp );
          for ( int p = 0; p < 4; p++ )
          {
            if ( dataBuffer[ pos[p] ] == NO_DATA )
            {
              dataBuffer[ pos[p] ] = 0;
            }
            dataBuffer[ pos[p] ] += pixelValue;
          }
        }
      }

      poBand->RasterIO( GF_Write, xPosition, yPosition, blockSize, blockSize,
                        dataBuffer, blockSize, blockSize, GDT_Float32, 0, 0 );
      CPLFree( dataBuffer );
    }
    // Finally close the dataset
    GDALClose(( GDALDatasetH ) heatmapDS );

    // Open the file in QGIS window
    mQGisIface->addRasterLayer( d.outputFilename(), QFileInfo( d.outputFilename() ).baseName() );
  }
}
Esempio n. 2
0
// Slot called when the menu item is triggered
// If you created more menu items / toolbar buttons in initiGui, you should
// create a separate handler for each action - this single run() method will
// not be enough
void Heatmap::run()
{
  HeatmapGui d( mQGisIface->mainWindow(), QgisGui::ModalDialogFlags, &mSessionSettings );

  //check that dialog found a suitable vector layer
  if ( !d.inputVectorLayer() )
  {
    mQGisIface->messageBar()->pushMessage( tr( "Layer not found" ), tr( "The heatmap plugin requires at least one point vector layer" ), QgsMessageBar::INFO, mQGisIface->messageTimeout() );
    return;
  }

  if ( d.exec() != QDialog::Accepted )
  {
    return;
  }

  QgsVectorLayer* inputLayer = d.inputVectorLayer();

  // Get the required data from the dialog
  QgsRectangle myBBox = d.bbox();
  int columns = d.columns();
  int rows = d.rows();
  double cellsize = d.cellSizeX(); // or d.cellSizeY();  both have the same value
  mDecay = d.decayRatio();
  KernelShape kernelShape = d.kernelShape();
  OutputValues valueType = d.outputValues();

  //is input layer multipoint?
  bool isMultiPoint = inputLayer->wkbType() == Qgis::WKBMultiPoint || inputLayer->wkbType() == Qgis::WKBMultiPoint25D;

  // Getting the rasterdataset in place
  GDALAllRegister();

  GDALDriverH myDriver = GDALGetDriverByName( d.outputFormat().toUtf8() );
  if ( !myDriver )
  {
    mQGisIface->messageBar()->pushMessage( tr( "GDAL driver error" ), tr( "Cannot open the driver for the specified format" ), QgsMessageBar::WARNING, mQGisIface->messageTimeout() );
    return;
  }

  double geoTransform[6] = { myBBox.xMinimum(), cellsize, 0, myBBox.yMinimum(), 0, cellsize };
  GDALDatasetH emptyDataset = GDALCreate( myDriver, d.outputFilename().toUtf8(), columns, rows, 1, GDT_Float32, nullptr );
  GDALSetGeoTransform( emptyDataset, geoTransform );
  // Set the projection on the raster destination to match the input layer
  GDALSetProjection( emptyDataset, inputLayer->crs().toWkt().toLocal8Bit().data() );

  GDALRasterBandH poBand = GDALGetRasterBand( emptyDataset, 1 );
  GDALSetRasterNoDataValue( poBand, NO_DATA );

  float* line = ( float * ) CPLMalloc( sizeof( float ) * columns );
  for ( int i = 0; i < columns ; i++ )
  {
    line[i] = NO_DATA;
  }
  // Write the empty raster
  for ( int i = 0; i < rows ; i++ )
  {
    if ( GDALRasterIO( poBand, GF_Write, 0, i, columns, 1, line, columns, 1, GDT_Float32, 0, 0 ) != CE_None )
    {
      QgsDebugMsg( "Raster IO Error" );
    }
  }

  CPLFree( line );
  //close the dataset
  GDALClose( emptyDataset );

  // open the raster in GA_Update mode
  GDALDatasetH heatmapDS = GDALOpen( TO8F( d.outputFilename() ), GA_Update );
  if ( !heatmapDS )
  {
    mQGisIface->messageBar()->pushMessage( tr( "Raster update error" ), tr( "Could not open the created raster for updating. The heatmap was not generated." ), QgsMessageBar::WARNING );
    return;
  }
  poBand = GDALGetRasterBand( heatmapDS, 1 );

  QgsAttributeList myAttrList;
  int rField = 0;
  int wField = 0;

  // Handle different radius options
  double radius;
  double radiusToMapUnits = 1;
  int myBuffer = 0;
  if ( d.variableRadius() )
  {
    rField = d.radiusField();
    myAttrList.append( rField );
    QgsDebugMsg( QString( "Radius Field index received: %1" ).arg( rField ) );

    // If not using map units, then calculate a conversion factor to convert the radii to map units
    if ( d.radiusUnit() == HeatmapGui::LayerUnits )
    {
      radiusToMapUnits = mapUnitsOf( 1, inputLayer->crs() );
    }
  }
  else
  {
    radius = d.radius(); // radius returned by d.radius() is already in map units
    myBuffer = bufferSize( radius, cellsize );
  }

  if ( d.weighted() )
  {
    wField = d.weightField();
    myAttrList.append( wField );
  }

  // This might have attributes or mightnot have attibutes at all
  // based on the variableRadius() and weighted()
  QgsFeatureIterator fit = inputLayer->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( myAttrList ) );
  int totalFeatures = inputLayer->featureCount();
  int counter = 0;

  QProgressDialog p( tr( "Rendering heatmap..." ), tr( "Abort" ), 0, totalFeatures, mQGisIface->mainWindow() );
  p.setWindowTitle( tr( "QGIS" ) );
  p.setWindowModality( Qt::ApplicationModal );
  p.show();

  QgsFeature myFeature;

  while ( fit.nextFeature( myFeature ) )
  {
    counter++;
    p.setValue( counter );
    QApplication::processEvents();
    if ( p.wasCanceled() )
    {
      mQGisIface->messageBar()->pushMessage( tr( "Heatmap generation aborted" ), tr( "QGIS will now load the partially-computed raster" ), QgsMessageBar::INFO, mQGisIface->messageTimeout() );
      break;
    }

    const QgsGeometry* featureGeometry = myFeature.constGeometry();
    if ( !featureGeometry )
    {
      continue;
    }

    // convert the geometry to multipoint
    QgsMultiPoint multiPoints;
    if ( !isMultiPoint )
    {
      QgsPoint myPoint = featureGeometry->asPoint();
      // avoiding any empty points or out of extent points
      if (( myPoint.x() < myBBox.xMinimum() ) || ( myPoint.y() < myBBox.yMinimum() )
          || ( myPoint.x() > myBBox.xMaximum() ) || ( myPoint.y() > myBBox.yMaximum() ) )
      {
        continue;
      }
      multiPoints << myPoint;
    }
    else
    {
      multiPoints = featureGeometry->asMultiPoint();
    }

    // If radius is variable then fetch it and calculate new pixel buffer size
    if ( d.variableRadius() )
    {
      radius = myFeature.attribute( rField ).toDouble() * radiusToMapUnits;
      myBuffer = bufferSize( radius, cellsize );
    }

    int blockSize = 2 * myBuffer + 1; //Block SIDE would be more appropriate

    double weight = 1.0;
    if ( d.weighted() )
    {
      weight = myFeature.attribute( wField ).toDouble();
    }

    //loop through all points in multipoint
    for ( QgsMultiPoint::const_iterator pointIt = multiPoints.constBegin(); pointIt != multiPoints.constEnd(); ++pointIt )
    {
      // avoiding any empty points or out of extent points
      if ((( *pointIt ).x() < myBBox.xMinimum() ) || (( *pointIt ).y() < myBBox.yMinimum() )
          || (( *pointIt ).x() > myBBox.xMaximum() ) || (( *pointIt ).y() > myBBox.yMaximum() ) )
      {
        continue;
      }

      // calculate the pixel position
      unsigned int xPosition, yPosition;
      xPosition = ((( *pointIt ).x() - myBBox.xMinimum() ) / cellsize ) - myBuffer;
      yPosition = ((( *pointIt ).y() - myBBox.yMinimum() ) / cellsize ) - myBuffer;

      // get the data
      float *dataBuffer = ( float * ) CPLMalloc( sizeof( float ) * blockSize * blockSize );
      if ( GDALRasterIO( poBand, GF_Read, xPosition, yPosition, blockSize, blockSize,
                         dataBuffer, blockSize, blockSize, GDT_Float32, 0, 0 ) != CE_None )
      {
        QgsDebugMsg( "Raster IO Error" );
      }

      for ( int xp = 0; xp <= myBuffer; xp++ )
      {
        for ( int yp = 0; yp <= myBuffer; yp++ )
        {
          double distance = sqrt( pow( xp, 2.0 ) + pow( yp, 2.0 ) );

          // is pixel outside search bandwidth of feature?
          if ( distance > myBuffer )
          {
            continue;
          }

          double pixelValue = weight * calculateKernelValue( distance, myBuffer, kernelShape, valueType );

          // clearing anamolies along the axes
          if ( xp == 0 && yp == 0 )
          {
            pixelValue /= 4;
          }
          else if ( xp == 0 || yp == 0 )
          {
            pixelValue /= 2;
          }

          int pos[4];
          pos[0] = ( myBuffer + xp ) * blockSize + ( myBuffer + yp );
          pos[1] = ( myBuffer + xp ) * blockSize + ( myBuffer - yp );
          pos[2] = ( myBuffer - xp ) * blockSize + ( myBuffer + yp );
          pos[3] = ( myBuffer - xp ) * blockSize + ( myBuffer - yp );
          for ( int p = 0; p < 4; p++ )
          {
            if ( dataBuffer[ pos[p] ] == NO_DATA )
            {
              dataBuffer[ pos[p] ] = 0;
            }
            dataBuffer[ pos[p] ] += pixelValue;
          }
        }
      }
      if ( GDALRasterIO( poBand, GF_Write, xPosition, yPosition, blockSize, blockSize,
                         dataBuffer, blockSize, blockSize, GDT_Float32, 0, 0 ) != CE_None )
      {
        QgsDebugMsg( "Raster IO Error" );
      }
      CPLFree( dataBuffer );
    }
  }

  // Finally close the dataset
  GDALClose(( GDALDatasetH ) heatmapDS );

  // Open the file in QGIS window if requested
  if ( d.addToCanvas() )
  {
    mQGisIface->addRasterLayer( d.outputFilename(), QFileInfo( d.outputFilename() ).baseName() );
  }

}