void QgsZonalStatistics::statisticsFromMiddlePointTest( void* band, const QgsGeometry& poly, int pixelOffsetX,
    int pixelOffsetY, int nCellsX, int nCellsY, double cellSizeX, double cellSizeY, const QgsRectangle& rasterBBox, FeatureStats &stats )
{
  double cellCenterX, cellCenterY;

  float* scanLine = ( float * ) CPLMalloc( sizeof( float ) * nCellsX );
  cellCenterY = rasterBBox.yMaximum() - pixelOffsetY * cellSizeY - cellSizeY / 2;
  stats.reset();

  GEOSGeometry* polyGeos = poly.exportToGeos();
  if ( !polyGeos )
  {
    return;
  }

  GEOSContextHandle_t geosctxt = QgsGeometry::getGEOSHandler();
  const GEOSPreparedGeometry* polyGeosPrepared = GEOSPrepare_r( geosctxt, polyGeos );
  if ( !polyGeosPrepared )
  {
    GEOSGeom_destroy_r( geosctxt, polyGeos );
    return;
  }

  GEOSCoordSequence* cellCenterCoords = nullptr;
  GEOSGeometry* currentCellCenter = nullptr;

  for ( int i = 0; i < nCellsY; ++i )
  {
    if ( GDALRasterIO( band, GF_Read, pixelOffsetX, pixelOffsetY + i, nCellsX, 1, scanLine, nCellsX, 1, GDT_Float32, 0, 0 )
         != CPLE_None )
    {
      continue;
    }
    cellCenterX = rasterBBox.xMinimum() + pixelOffsetX * cellSizeX + cellSizeX / 2;
    for ( int j = 0; j < nCellsX; ++j )
    {
      if ( validPixel( scanLine[j] ) )
      {
        GEOSGeom_destroy_r( geosctxt, currentCellCenter );
        cellCenterCoords = GEOSCoordSeq_create_r( geosctxt, 1, 2 );
        GEOSCoordSeq_setX_r( geosctxt, cellCenterCoords, 0, cellCenterX );
        GEOSCoordSeq_setY_r( geosctxt, cellCenterCoords, 0, cellCenterY );
        currentCellCenter = GEOSGeom_createPoint_r( geosctxt, cellCenterCoords );
        if ( GEOSPreparedContains_r( geosctxt, polyGeosPrepared, currentCellCenter ) )
        {
          stats.addValue( scanLine[j] );
        }
      }
      cellCenterX += cellSizeX;
    }
    cellCenterY -= cellSizeY;
  }
  GEOSGeom_destroy_r( geosctxt, currentCellCenter );
  CPLFree( scanLine );
  GEOSPreparedGeom_destroy_r( geosctxt, polyGeosPrepared );
  GEOSGeom_destroy_r( geosctxt, polyGeos );
}
示例#2
0
void QgsZonalStatistics::statisticsFromMiddlePointTest( const QgsGeometry &poly, int pixelOffsetX,
    int pixelOffsetY, int nCellsX, int nCellsY, double cellSizeX, double cellSizeY, const QgsRectangle &rasterBBox, FeatureStats &stats )
{
  double cellCenterX, cellCenterY;

  cellCenterY = rasterBBox.yMaximum() - pixelOffsetY * cellSizeY - cellSizeY / 2;
  stats.reset();

  GEOSGeometry *polyGeos = poly.exportToGeos();
  if ( !polyGeos )
  {
    return;
  }

  GEOSContextHandle_t geosctxt = QgsGeometry::getGEOSHandler();
  const GEOSPreparedGeometry *polyGeosPrepared = GEOSPrepare_r( geosctxt, polyGeos );
  if ( !polyGeosPrepared )
  {
    GEOSGeom_destroy_r( geosctxt, polyGeos );
    return;
  }

  GEOSCoordSequence *cellCenterCoords = nullptr;
  GEOSGeometry *currentCellCenter = nullptr;

  QgsRectangle featureBBox = poly.boundingBox().intersect( &rasterBBox );
  QgsRectangle intersectBBox = rasterBBox.intersect( &featureBBox );

  QgsRasterBlock *block = mRasterProvider->block( mRasterBand, intersectBBox, nCellsX, nCellsY );
  for ( int i = 0; i < nCellsY; ++i )
  {
    cellCenterX = rasterBBox.xMinimum() + pixelOffsetX * cellSizeX + cellSizeX / 2;
    for ( int j = 0; j < nCellsX; ++j )
    {
      if ( validPixel( block->value( i, j ) ) )
      {
        GEOSGeom_destroy_r( geosctxt, currentCellCenter );
        cellCenterCoords = GEOSCoordSeq_create_r( geosctxt, 1, 2 );
        GEOSCoordSeq_setX_r( geosctxt, cellCenterCoords, 0, cellCenterX );
        GEOSCoordSeq_setY_r( geosctxt, cellCenterCoords, 0, cellCenterY );
        currentCellCenter = GEOSGeom_createPoint_r( geosctxt, cellCenterCoords );
        if ( GEOSPreparedContains_r( geosctxt, polyGeosPrepared, currentCellCenter ) )
        {
          stats.addValue( block->value( i, j ) );
        }
      }
      cellCenterX += cellSizeX;
    }
    cellCenterY -= cellSizeY;
  }

  GEOSGeom_destroy_r( geosctxt, currentCellCenter );
  GEOSPreparedGeom_destroy_r( geosctxt, polyGeosPrepared );
  GEOSGeom_destroy_r( geosctxt, polyGeos );
  delete block;
}
示例#3
0
void QgsZonalStatistics::statisticsFromPreciseIntersection( const QgsGeometry &poly, int pixelOffsetX,
    int pixelOffsetY, int nCellsX, int nCellsY, double cellSizeX, double cellSizeY, const QgsRectangle &rasterBBox, FeatureStats &stats )
{
  stats.reset();

  double currentY = rasterBBox.yMaximum() - pixelOffsetY * cellSizeY - cellSizeY / 2;
  QgsGeometry pixelRectGeometry;

  double hCellSizeX = cellSizeX / 2.0;
  double hCellSizeY = cellSizeY / 2.0;
  double pixelArea = cellSizeX * cellSizeY;
  double weight = 0;

  QgsRectangle featureBBox = poly.boundingBox().intersect( &rasterBBox );
  QgsRectangle intersectBBox = rasterBBox.intersect( &featureBBox );

  QgsRasterBlock *block = mRasterProvider->block( mRasterBand, intersectBBox, nCellsX, nCellsY );
  for ( int i = 0; i < nCellsY; ++i )
  {
    double currentX = rasterBBox.xMinimum() + cellSizeX / 2.0 + pixelOffsetX * cellSizeX;
    for ( int j = 0; j < nCellsX; ++j )
    {
      if ( !validPixel( block->value( i, j ) ) )
      {
        continue;
      }

      pixelRectGeometry = QgsGeometry::fromRect( QgsRectangle( currentX - hCellSizeX, currentY - hCellSizeY, currentX + hCellSizeX, currentY + hCellSizeY ) );
      if ( !pixelRectGeometry.isNull() )
      {
        //intersection
        QgsGeometry intersectGeometry = pixelRectGeometry.intersection( poly );
        if ( !intersectGeometry.isNull() )
        {
          double intersectionArea = intersectGeometry.area();
          if ( intersectionArea >= 0.0 )
          {
            weight = intersectionArea / pixelArea;
            stats.addValue( block->value( i, j ), weight );
          }
        }
        pixelRectGeometry = QgsGeometry();
      }
      currentX += cellSizeX;
    }
    currentY -= cellSizeY;
  }
  delete block;
}
示例#4
0
void QgsZonalStatistics::statisticsFromPreciseIntersection( void* band, const QgsGeometry* poly, int pixelOffsetX,
    int pixelOffsetY, int nCellsX, int nCellsY, double cellSizeX, double cellSizeY, const QgsRectangle& rasterBBox, FeatureStats &stats )
{
  stats.reset();

  double currentY = rasterBBox.yMaximum() - pixelOffsetY * cellSizeY - cellSizeY / 2;
  float* pixelData = ( float * ) CPLMalloc( sizeof( float ) );
  QgsGeometry* pixelRectGeometry = nullptr;

  double hCellSizeX = cellSizeX / 2.0;
  double hCellSizeY = cellSizeY / 2.0;
  double pixelArea = cellSizeX * cellSizeY;
  double weight = 0;

  for ( int row = 0; row < nCellsY; ++row )
  {
    double currentX = rasterBBox.xMinimum() + cellSizeX / 2.0 + pixelOffsetX * cellSizeX;
    for ( int col = 0; col < nCellsX; ++col )
    {
      if ( GDALRasterIO( band, GF_Read, pixelOffsetX + col, pixelOffsetY + row, nCellsX, 1, pixelData, 1, 1, GDT_Float32, 0, 0 ) != CE_None )
        QgsDebugMsg( "Raster IO Error" );

      if ( !validPixel( *pixelData ) )
        continue;

      pixelRectGeometry = QgsGeometry::fromRect( QgsRectangle( currentX - hCellSizeX, currentY - hCellSizeY, currentX + hCellSizeX, currentY + hCellSizeY ) );
      if ( pixelRectGeometry )
      {
        //intersection
        QgsGeometry *intersectGeometry = pixelRectGeometry->intersection( poly );
        if ( intersectGeometry )
        {
          double intersectionArea = intersectGeometry->area();
          if ( intersectionArea >= 0.0 )
          {
            weight = intersectionArea / pixelArea;
            stats.addValue( *pixelData, weight );
          }
          delete intersectGeometry;
        }
        delete pixelRectGeometry;
        pixelRectGeometry = nullptr;
      }
      currentX += cellSizeX;
    }
    currentY -= cellSizeY;
  }
  CPLFree( pixelData );
}