QgsRasterBlock* QgsSingleBandColorDataRenderer::block( int bandNo, QgsRectangle  const & extent, int width, int height, QgsRasterBlockFeedback* feedback )
{
  Q_UNUSED( bandNo );

  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput )
  {
    return outputBlock;
  }

  QgsRasterBlock *inputBlock = mInput->block( mBand, extent, width, height, feedback );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  bool hasTransparency = usesTransparency();
  if ( !hasTransparency )
  {
    // Nothing to do, just retype if necessary
    inputBlock->convert( Qgis::ARGB32_Premultiplied );
    delete outputBlock;
    return inputBlock;
  }

  if ( !outputBlock->reset( Qgis::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    return outputBlock;
  }

  // make sure input is also premultiplied!
  inputBlock->convert( Qgis::ARGB32_Premultiplied );

  QRgb* inputBits = ( QRgb* )inputBlock->bits();
  QRgb* outputBits = ( QRgb* )outputBlock->bits();
  for ( qgssize i = 0; i < ( qgssize )width*height; i++ )
  {
    QRgb c = inputBits[i];
    outputBits[i] = qRgba( mOpacity * qRed( c ), mOpacity * qGreen( c ), mOpacity * qBlue( c ), mOpacity * qAlpha( c ) );
  }

  delete inputBlock;
  return outputBlock;
}
QgsRasterBlock* QgsSingleBandColorDataRenderer::block( int bandNo, QgsRectangle  const & extent, int width, int height )
{
  Q_UNUSED( bandNo );

  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput )
  {
    return outputBlock;
  }

  QgsRasterBlock *inputBlock = mInput->block( mBand, extent, width, height );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  bool hasTransparency = usesTransparency();
  if ( !hasTransparency )
  {
    // Nothing to do, just retype if necessary
    inputBlock->convert( QgsRasterBlock::ARGB32_Premultiplied );
    delete outputBlock;
    return inputBlock;
  }

  if ( !outputBlock->reset( QgsRasterBlock::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    return outputBlock;
  }

  for ( size_t i = 0; i < ( size_t )width*height; i++ )
  {
    QRgb pixelColor;
    double alpha = 255.0;
    QRgb c = inputBlock->color( i );
    alpha = qAlpha( c );
    pixelColor = qRgba( mOpacity * qRed( c ), mOpacity * qGreen( c ), mOpacity * qBlue( c ), mOpacity * alpha );
    outputBlock->setColor( i,  pixelColor );
  }

  delete inputBlock;
  return outputBlock;
}
Example #3
0
QgsRasterBlock *QgsRasterDataProvider::block( int bandNo, QgsRectangle  const &boundingBox, int width, int height, QgsRasterBlockFeedback *feedback )
{
  QgsDebugMsgLevel( QString( "bandNo = %1 width = %2 height = %3" ).arg( bandNo ).arg( width ).arg( height ), 4 );
  QgsDebugMsgLevel( QString( "boundingBox = %1" ).arg( boundingBox.toString() ), 4 );

  QgsRasterBlock *block = new QgsRasterBlock( dataType( bandNo ), width, height );
  if ( sourceHasNoDataValue( bandNo ) && useSourceNoDataValue( bandNo ) )
  {
    block->setNoDataValue( sourceNoDataValue( bandNo ) );
  }

  if ( block->isEmpty() )
  {
    QgsDebugMsg( "Couldn't create raster block" );
    return block;
  }

  // Read necessary extent only
  QgsRectangle tmpExtent = extent().intersect( &boundingBox );

  if ( tmpExtent.isEmpty() )
  {
    QgsDebugMsg( "Extent outside provider extent" );
    block->setIsNoData();
    return block;
  }

  double xRes = boundingBox.width() / width;
  double yRes = boundingBox.height() / height;
  double tmpXRes, tmpYRes;
  double providerXRes = 0;
  double providerYRes = 0;
  if ( capabilities() & Size )
  {
    providerXRes = extent().width() / xSize();
    providerYRes = extent().height() / ySize();
    tmpXRes = std::max( providerXRes, xRes );
    tmpYRes = std::max( providerYRes, yRes );
    if ( qgsDoubleNear( tmpXRes, xRes ) ) tmpXRes = xRes;
    if ( qgsDoubleNear( tmpYRes, yRes ) ) tmpYRes = yRes;
  }
  else
  {
    tmpXRes = xRes;
    tmpYRes = yRes;
  }

  if ( tmpExtent != boundingBox ||
       tmpXRes > xRes || tmpYRes > yRes )
  {
    // Read smaller extent or lower resolution

    if ( !extent().contains( boundingBox ) )
    {
      QRect subRect = QgsRasterBlock::subRect( boundingBox, width, height, extent() );
      block->setIsNoDataExcept( subRect );
    }

    // Calculate row/col limits (before tmpExtent is aligned)
    int fromRow = std::round( ( boundingBox.yMaximum() - tmpExtent.yMaximum() ) / yRes );
    int toRow = std::round( ( boundingBox.yMaximum() - tmpExtent.yMinimum() ) / yRes ) - 1;
    int fromCol = std::round( ( tmpExtent.xMinimum() - boundingBox.xMinimum() ) / xRes );
    int toCol = std::round( ( tmpExtent.xMaximum() - boundingBox.xMinimum() ) / xRes ) - 1;

    QgsDebugMsgLevel( QString( "fromRow = %1 toRow = %2 fromCol = %3 toCol = %4" ).arg( fromRow ).arg( toRow ).arg( fromCol ).arg( toCol ), 4 );

    if ( fromRow < 0 || fromRow >= height || toRow < 0 || toRow >= height ||
         fromCol < 0 || fromCol >= width || toCol < 0 || toCol >= width )
    {
      // Should not happen
      QgsDebugMsg( "Row or column limits out of range" );
      return block;
    }

    // If lower source resolution is used, the extent must beS aligned to original
    // resolution to avoid possible shift due to resampling
    if ( tmpXRes > xRes )
    {
      int col = std::floor( ( tmpExtent.xMinimum() - extent().xMinimum() ) / providerXRes );
      tmpExtent.setXMinimum( extent().xMinimum() + col * providerXRes );
      col = std::ceil( ( tmpExtent.xMaximum() - extent().xMinimum() ) / providerXRes );
      tmpExtent.setXMaximum( extent().xMinimum() + col * providerXRes );
    }
    if ( tmpYRes > yRes )
    {
      int row = std::floor( ( extent().yMaximum() - tmpExtent.yMaximum() ) / providerYRes );
      tmpExtent.setYMaximum( extent().yMaximum() - row * providerYRes );
      row = std::ceil( ( extent().yMaximum() - tmpExtent.yMinimum() ) / providerYRes );
      tmpExtent.setYMinimum( extent().yMaximum() - row * providerYRes );
    }
    int tmpWidth = std::round( tmpExtent.width() / tmpXRes );
    int tmpHeight = std::round( tmpExtent.height() / tmpYRes );
    tmpXRes = tmpExtent.width() / tmpWidth;
    tmpYRes = tmpExtent.height() / tmpHeight;

    QgsDebugMsgLevel( QString( "Reading smaller block tmpWidth = %1 height = %2" ).arg( tmpWidth ).arg( tmpHeight ), 4 );
    QgsDebugMsgLevel( QString( "tmpExtent = %1" ).arg( tmpExtent.toString() ), 4 );

    QgsRasterBlock *tmpBlock = new QgsRasterBlock( dataType( bandNo ), tmpWidth, tmpHeight );
    if ( sourceHasNoDataValue( bandNo ) && useSourceNoDataValue( bandNo ) )
    {
      tmpBlock->setNoDataValue( sourceNoDataValue( bandNo ) );
    }

    readBlock( bandNo, tmpExtent, tmpWidth, tmpHeight, tmpBlock->bits(), feedback );

    int pixelSize = dataTypeSize( bandNo );

    double xMin = boundingBox.xMinimum();
    double yMax = boundingBox.yMaximum();
    double tmpXMin = tmpExtent.xMinimum();
    double tmpYMax = tmpExtent.yMaximum();

    for ( int row = fromRow; row <= toRow; row++ )
    {
      double y = yMax - ( row + 0.5 ) * yRes;
      int tmpRow = std::floor( ( tmpYMax - y ) / tmpYRes );

      for ( int col = fromCol; col <= toCol; col++ )
      {
        double x = xMin + ( col + 0.5 ) * xRes;
        int tmpCol = std::floor( ( x - tmpXMin ) / tmpXRes );

        if ( tmpRow < 0 || tmpRow >= tmpHeight || tmpCol < 0 || tmpCol >= tmpWidth )
        {
          QgsDebugMsg( "Source row or column limits out of range" );
          block->setIsNoData(); // so that the problem becomes obvious and fixed
          delete tmpBlock;
          return block;
        }

        qgssize tmpIndex = static_cast< qgssize >( tmpRow ) * static_cast< qgssize >( tmpWidth ) + tmpCol;
        qgssize index = row * static_cast< qgssize >( width ) + col;

        char *tmpBits = tmpBlock->bits( tmpIndex );
        char *bits = block->bits( index );
        if ( !tmpBits )
        {
          QgsDebugMsg( QString( "Cannot get input block data tmpRow = %1 tmpCol = %2 tmpIndex = %3." ).arg( tmpRow ).arg( tmpCol ).arg( tmpIndex ) );
          continue;
        }
        if ( !bits )
        {
          QgsDebugMsg( "Cannot set output block data." );
          continue;
        }
        memcpy( bits, tmpBits, pixelSize );
      }
    }

    delete tmpBlock;
  }
  else
  {
    readBlock( bandNo, boundingBox, width, height, block->bits(), feedback );
  }

  // apply scale and offset
  block->applyScaleOffset( bandScale( bandNo ), bandOffset( bandNo ) );
  // apply user no data values
  block->applyNoDataValues( userNoDataValues( bandNo ) );
  return block;
}
QgsRasterBlock* QgsSingleBandGrayRenderer::block( int bandNo, QgsRectangle  const & extent, int width, int height )
{
  Q_UNUSED( bandNo );
  QgsDebugMsg( QString( "width = %1 height = %2" ).arg( width ).arg( height ) );

  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput )
  {
    return outputBlock;
  }

  QgsRasterBlock *inputBlock = mInput->block( mGrayBand, extent, width, height );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  QgsRasterBlock *alphaBlock = 0;

  if ( mAlphaBand > 0 && mGrayBand != mAlphaBand )
  {
    alphaBlock = mInput->block( mAlphaBand, extent, width, height );
    if ( !alphaBlock || alphaBlock->isEmpty() )
    {
      // TODO: better to render without alpha
      delete inputBlock;
      delete alphaBlock;
      return outputBlock;
    }
  }
  else if ( mAlphaBand > 0 )
  {
    alphaBlock = inputBlock;
  }

  if ( !outputBlock->reset( QGis::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    delete alphaBlock;
    return outputBlock;
  }

  QRgb myDefaultColor = NODATA_COLOR;
  for ( qgssize i = 0; i < ( qgssize )width*height; i++ )
  {
    if ( inputBlock->isNoData( i ) )
    {
      outputBlock->setColor( i, myDefaultColor );
      continue;
    }
    double grayVal = inputBlock->value( i );

    double currentAlpha = mOpacity;
    if ( mRasterTransparency )
    {
      currentAlpha = mRasterTransparency->alphaValue( grayVal, mOpacity * 255 ) / 255.0;
    }
    if ( mAlphaBand > 0 )
    {
      currentAlpha *= alphaBlock->value( i ) / 255.0;
    }

    if ( mContrastEnhancement )
    {
      if ( !mContrastEnhancement->isValueInDisplayableRange( grayVal ) )
      {
        outputBlock->setColor( i, myDefaultColor );
        continue;
      }
      grayVal = mContrastEnhancement->enhanceContrast( grayVal );
    }

    if ( mGradient == WhiteToBlack )
    {
      grayVal = 255 - grayVal;
    }

    if ( qgsDoubleNear( currentAlpha, 1.0 ) )
    {
      outputBlock->setColor( i, qRgba( grayVal, grayVal, grayVal, 255 ) );
    }
    else
    {
      outputBlock->setColor( i, qRgba( currentAlpha * grayVal, currentAlpha * grayVal, currentAlpha * grayVal, currentAlpha * 255 ) );
    }
  }

  delete inputBlock;
  if ( mAlphaBand > 0 && mGrayBand != mAlphaBand )
  {
    delete alphaBlock;
  }

  return outputBlock;
}
QgsRasterBlock *QgsHillshadeRenderer::block( int bandNo, const QgsRectangle &extent, int width, int height, QgsRasterBlockFeedback* feedback )
{
    Q_UNUSED( bandNo );
    QgsRasterBlock *outputBlock = new QgsRasterBlock();
    if ( !mInput )
    {
        QgsDebugMsg( "No input raster!" );
        return outputBlock;
    }

    QgsRasterBlock *inputBlock = mInput->block( mBand, extent, width, height, feedback );

    if ( !inputBlock || inputBlock->isEmpty() )
    {
        QgsDebugMsg( "No raster data!" );
        delete inputBlock;
        return outputBlock;
    }

    QgsRasterBlock *alphaBlock = nullptr;

    if ( mAlphaBand > 0 && mBand != mAlphaBand )
    {

        alphaBlock = mInput->block( mAlphaBand, extent, width, height, feedback );
        if ( !alphaBlock || alphaBlock->isEmpty() )
        {
            // TODO: better to render without alpha
            delete inputBlock;
            delete alphaBlock;
            return outputBlock;
        }
    }
    else if ( mAlphaBand > 0 )
    {
        alphaBlock = inputBlock;
    }

    if ( !outputBlock->reset( Qgis::ARGB32_Premultiplied, width, height ) )
    {
        delete inputBlock;
        delete alphaBlock;
        return outputBlock;
    }



    double cellXSize = extent.width() / double( width );
    double cellYSize = extent.height() / double( height );
    double zenithRad = qMax( 0.0, 90 - mLightAngle ) * M_PI / 180.0;
    double azimuthRad = -1 * mLightAzimuth * M_PI / 180.0;
    double cosZenithRad = cos( zenithRad );
    double sinZenithRad = sin( zenithRad );

    // Multi direction hillshade: http://pubs.usgs.gov/of/1992/of92-422/of92-422.pdf
    double angle0Rad = ( -1 * mLightAzimuth - 45 - 45 * 0.5 ) * M_PI / 180.0;
    double angle1Rad = ( -1 * mLightAzimuth - 45 * 0.5 ) * M_PI / 180.0;
    double angle2Rad = ( -1 * mLightAzimuth + 45 * 0.5 ) * M_PI / 180.0;
    double angle3Rad = ( -1 * mLightAzimuth + 45 + 45 * 0.5 ) * M_PI / 180.0;

    QRgb myDefaultColor = NODATA_COLOR;

    for ( qgssize i = 0; i < ( qgssize )height; i++ )
    {

        for ( qgssize j = 0; j < ( qgssize )width; j++ )
        {

            if ( inputBlock->isNoData( i, j ) )
            {
                outputBlock->setColor( i, j, myDefaultColor );
                continue;
            }

            qgssize iUp, iDown, jLeft, jRight;
            if ( i == 0 )
            {
                iUp = i;
                iDown = i + 1;
            }
            else if ( i < ( qgssize )height - 1 )
            {
                iUp = i - 1;
                iDown = i + 1;
            }
            else
            {
                iUp = i - 1;
                iDown = i;
            }

            if ( j == 0 )
            {
                jLeft = j;
                jRight = j + 1;
            }
            else if ( j < ( qgssize )width - 1 )
            {
                jLeft = j - 1;
                jRight = j + 1;
            }
            else
            {
                jLeft = j - 1;
                jRight = j;
            }

            double x11;
            double x21;
            double x31;
            double x12;
            double x22; // Working cell
            double x32;
            double x13;
            double x23;
            double x33;

            // This is center cell. It is not nodata. Use this in place of nodata neighbors
            x22 = inputBlock->value( i, j );

            x11 = inputBlock->isNoData( iUp, jLeft )  ? x22 : inputBlock->value( iUp, jLeft );
            x21 = inputBlock->isNoData( i, jLeft )     ? x22 : inputBlock->value( i, jLeft );
            x31 = inputBlock->isNoData( iDown, jLeft ) ? x22 : inputBlock->value( iDown, jLeft );

            x12 = inputBlock->isNoData( iUp, j )       ? x22 : inputBlock->value( iUp, j );
            // x22
            x32 = inputBlock->isNoData( iDown, j )     ? x22 : inputBlock->value( iDown, j );

            x13 = inputBlock->isNoData( iUp, jRight )   ? x22 : inputBlock->value( iUp, jRight );
            x23 = inputBlock->isNoData( i, jRight )     ? x22 : inputBlock->value( i, jRight );
            x33 = inputBlock->isNoData( iDown, jRight ) ? x22 : inputBlock->value( iDown, jRight );

            double derX = calcFirstDerX( x11, x21, x31, x12, x22, x32, x13, x23, x33, cellXSize );
            double derY = calcFirstDerY( x11, x21, x31, x12, x22, x32, x13, x23, x33, cellYSize );

            double slopeRad = atan( mZFactor * sqrt( derX * derX + derY * derY ) );
            double aspectRad = atan2( derX, -derY );


            double grayValue;
            if ( !mMultiDirectional )
            {
                // Standard single direction hillshade
                grayValue = qBound( 0.0, 255.0 * ( cosZenithRad * cos( slopeRad )
                                                   + sinZenithRad * sin( slopeRad )
                                                   * cos( azimuthRad - aspectRad ) ) , 255.0 );
            }
            else
            {
                // Weighted multi direction as in http://pubs.usgs.gov/of/1992/of92-422/of92-422.pdf
                double weight0 = sin( aspectRad - angle0Rad );
                double weight1 = sin( aspectRad - angle1Rad );
                double weight2 = sin( aspectRad - angle2Rad );
                double weight3 = sin( aspectRad - angle3Rad );
                weight0 = weight0 * weight0;
                weight1 = weight1 * weight1;
                weight2 = weight2 * weight2;
                weight3 = weight3 * weight3;

                double cosSlope = cosZenithRad * cos( slopeRad );
                double sinSlope = sinZenithRad * sin( slopeRad );
                double color0 = cosSlope + sinSlope * cos( angle0Rad - aspectRad ) ;
                double color1 = cosSlope + sinSlope * cos( angle1Rad - aspectRad ) ;
                double color2 = cosSlope + sinSlope * cos( angle2Rad - aspectRad ) ;
                double color3 = cosSlope + sinSlope * cos( angle3Rad - aspectRad ) ;
                grayValue = qBound( 0.0, 255 * ( weight0 * color0 + weight1 * color1 + weight2 * color2 + weight3 * color3 ) * 0.5, 255.0 );
            }

            double currentAlpha = mOpacity;
            if ( mRasterTransparency )
            {
                currentAlpha = mRasterTransparency->alphaValue( x22, mOpacity * 255 ) / 255.0;
            }
            if ( mAlphaBand > 0 )
            {
                currentAlpha *= alphaBlock->value( i ) / 255.0;
            }

            if ( qgsDoubleNear( currentAlpha, 1.0 ) )
            {
                outputBlock->setColor( i, j, qRgba( grayValue, grayValue, grayValue, 255 ) );
            }
            else
            {
                outputBlock->setColor( i, j, qRgba( currentAlpha * grayValue, currentAlpha * grayValue, currentAlpha * grayValue, currentAlpha * 255 ) );
            }
        }
    }

    delete inputBlock;
    if ( mAlphaBand > 0 && mBand != mAlphaBand )
    {
        delete alphaBlock;
    }
    return outputBlock;
}
Example #6
0
QgsRasterBlock* QgsSingleBandPseudoColorRenderer::block( int bandNo, QgsRectangle  const & extent, int width, int height, QgsRasterBlockFeedback* feedback )
{
  Q_UNUSED( bandNo );

  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput || !mShader )
  {
    return outputBlock;
  }


  QgsRasterBlock *inputBlock = mInput->block( mBand, extent, width, height, feedback );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  //rendering is faster without considering user-defined transparency
  bool hasTransparency = usesTransparency();

  QgsRasterBlock *alphaBlock = nullptr;
  if ( mAlphaBand > 0 && mAlphaBand != mBand )
  {
    alphaBlock = mInput->block( mAlphaBand, extent, width, height, feedback );
    if ( !alphaBlock || alphaBlock->isEmpty() )
    {
      delete inputBlock;
      delete alphaBlock;
      return outputBlock;
    }
  }
  else if ( mAlphaBand == mBand )
  {
    alphaBlock = inputBlock;
  }

  if ( !outputBlock->reset( Qgis::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    delete alphaBlock;
    return outputBlock;
  }

  QRgb myDefaultColor = NODATA_COLOR;

  for ( qgssize i = 0; i < ( qgssize )width*height; i++ )
  {
    if ( inputBlock->isNoData( i ) )
    {
      outputBlock->setColor( i, myDefaultColor );
      continue;
    }
    double val = inputBlock->value( i );
    int red, green, blue, alpha;
    if ( !mShader->shade( val, &red, &green, &blue, &alpha ) )
    {
      outputBlock->setColor( i, myDefaultColor );
      continue;
    }

    if ( alpha < 255 )
    {
      // Working with premultiplied colors, so multiply values by alpha
      red *= ( alpha / 255.0 );
      blue *= ( alpha / 255.0 );
      green *= ( alpha / 255.0 );
    }

    if ( !hasTransparency )
    {
      outputBlock->setColor( i, qRgba( red, green, blue, alpha ) );
    }
    else
    {
      //opacity
      double currentOpacity = mOpacity;
      if ( mRasterTransparency )
      {
        currentOpacity = mRasterTransparency->alphaValue( val, mOpacity * 255 ) / 255.0;
      }
      if ( mAlphaBand > 0 )
      {
        currentOpacity *= alphaBlock->value( i ) / 255.0;
      }

      outputBlock->setColor( i, qRgba( currentOpacity * red, currentOpacity * green, currentOpacity * blue, currentOpacity * alpha ) );
    }
  }

  delete inputBlock;
  if ( mAlphaBand > 0 && mBand != mAlphaBand )
  {
    delete alphaBlock;
  }

  return outputBlock;
}
QgsRasterBlock* QgsRasterResampleFilter::block2( int bandNo, QgsRectangle  const & extent, int width, int height, QgsRasterBlockFeedback *feedback )
{
  Q_UNUSED( bandNo );
  QgsDebugMsg( QString( "width = %1 height = %2 extent = %3" ).arg( width ).arg( height ).arg( extent.toString() ) );
  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput ) return outputBlock;

  double oversampling = 1.0; // approximate global oversampling factor

  if ( mZoomedInResampler || mZoomedOutResampler )
  {
    QgsRasterDataProvider *provider = dynamic_cast<QgsRasterDataProvider*>( mInput->srcInput() );
    if ( provider && ( provider->capabilities() & QgsRasterDataProvider::Size ) )
    {
      double xRes = extent.width() / width;
      double providerXRes = provider->extent().width() / provider->xSize();
      double pixelRatio = xRes / providerXRes;
      oversampling = ( pixelRatio > mMaxOversampling ) ? mMaxOversampling : pixelRatio;
      QgsDebugMsg( QString( "xRes = %1 providerXRes = %2 pixelRatio = %3 oversampling = %4" ).arg( xRes ).arg( providerXRes ).arg( pixelRatio ).arg( oversampling ) );
    }
    else
    {
      // We don't know exact data source resolution (WMS) so we expect that
      // server data have higher resolution (which is not always true) and use
      // mMaxOversampling
      oversampling = mMaxOversampling;
    }
  }

  QgsDebugMsg( QString( "oversampling %1" ).arg( oversampling ) );

  int bandNumber = 1;

  // Do no oversampling if no resampler for zoomed in / zoomed out (nearest neighbour)
  // We do mZoomedInResampler if oversampling == 1 (otherwise for example reprojected
  // zoom in rasters are never resampled because projector limits resolution.
  if ((( oversampling < 1.0 || qgsDoubleNear( oversampling, 1.0 ) ) && !mZoomedInResampler ) || ( oversampling > 1.0 && !mZoomedOutResampler ) )
  {
    QgsDebugMsg( "No oversampling." );
    delete outputBlock;
    return mInput->block2( bandNumber, extent, width, height, feedback );
  }

  //effective oversampling factors are different to global one because of rounding
  double oversamplingX = (( double )width * oversampling ) / width;
  double oversamplingY = (( double )height * oversampling ) / height;

  // TODO: we must also increase the extent to get correct result on borders of parts

  int resWidth = width * oversamplingX;
  int resHeight = height * oversamplingY;

  QgsRasterBlock *inputBlock = mInput->block2( bandNumber, extent, resWidth, resHeight, feedback );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  if ( !outputBlock->reset( QGis::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    return outputBlock;
  }

  //resample image
  QImage img = inputBlock->image();

  QImage dstImg = QImage( width, height, QImage::Format_ARGB32_Premultiplied );

  if ( mZoomedInResampler && ( oversamplingX < 1.0 || qgsDoubleNear( oversampling, 1.0 ) ) )
  {
    QgsDebugMsg( "zoomed in resampling" );
    mZoomedInResampler->resample( img, dstImg );
  }
  else if ( mZoomedOutResampler && oversamplingX > 1.0 )
  {
    QgsDebugMsg( "zoomed out resampling" );
    mZoomedOutResampler->resample( img, dstImg );
  }
  else
  {
    // Should not happen
    QgsDebugMsg( "Unexpected resampling" );
    dstImg = img.scaled( width, height );
  }

  outputBlock->setImage( &dstImg );

  delete inputBlock;
  return outputBlock; // No resampling
}
QgsRasterBlock * QgsPalettedRasterRenderer::block( int bandNo, QgsRectangle  const & extent, int width, int height )
{
    QgsRasterBlock *outputBlock = new QgsRasterBlock();
    if ( !mInput )
    {
        return outputBlock;
    }

    QgsRasterBlock *inputBlock = mInput->block( bandNo, extent, width, height );

    if ( !inputBlock || inputBlock->isEmpty() )
    {
        QgsDebugMsg( "No raster data!" );
        delete inputBlock;
        return outputBlock;
    }

    double currentOpacity = mOpacity;

    //rendering is faster without considering user-defined transparency
    bool hasTransparency = usesTransparency();
    QgsRasterBlock *alphaBlock = 0;

    if ( mAlphaBand > 0 && mAlphaBand != mBand )
    {
        alphaBlock = mInput->block( mAlphaBand, extent, width, height );
        if ( !alphaBlock || alphaBlock->isEmpty() )
        {
            delete inputBlock;
            delete alphaBlock;
            return outputBlock;
        }
    }
    else if ( mAlphaBand == mBand )
    {
        alphaBlock = inputBlock;
    }

    if ( !outputBlock->reset( QGis::ARGB32_Premultiplied, width, height ) )
    {
        delete inputBlock;
        delete alphaBlock;
        return outputBlock;
    }

    QRgb myDefaultColor = NODATA_COLOR;

    //use direct data access instead of QgsRasterBlock::setValue
    //because of performance
    unsigned int* outputData = ( unsigned int* )( outputBlock->bits() );

    qgssize rasterSize = ( qgssize )width * height;
    for ( qgssize i = 0; i < rasterSize; ++i )
    {
        if ( inputBlock->isNoData( i ) )
        {
            outputData[i] = myDefaultColor;
            continue;
        }
        int val = ( int ) inputBlock->value( i );
        if ( !hasTransparency )
        {
            outputData[i] = mColors[val];
        }
        else
        {
            currentOpacity = mOpacity;
            if ( mRasterTransparency )
            {
                currentOpacity = mRasterTransparency->alphaValue( val, mOpacity * 255 ) / 255.0;
            }
            if ( mAlphaBand > 0 )
            {
                currentOpacity *=  alphaBlock->value( i ) / 255.0;
            }
            QColor currentColor = QColor( mColors[val] );
            outputData[i] = qRgba( currentOpacity * currentColor.red(), currentOpacity * currentColor.green(), currentOpacity * currentColor.blue(), currentOpacity * 255 );
        }
    }

    delete inputBlock;
    if ( mAlphaBand > 0 && mBand != mAlphaBand )
    {
        delete alphaBlock;
    }

    return outputBlock;
}
QgsRasterBlock * QgsRasterResampleFilter::block( int bandNo, QgsRectangle  const & extent, int width, int height )
{
  Q_UNUSED( bandNo );
  QgsDebugMsg( "Entered" );
  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput ) return outputBlock;

  double oversampling = 1.0; // approximate global oversampling factor

  if ( mZoomedInResampler || mZoomedOutResampler )
  {
    QgsRasterDataProvider *provider = dynamic_cast<QgsRasterDataProvider*>( mInput->srcInput() );
    // Do not oversample if data source does not have fixed resolution (WMS)
    if ( provider && ( provider->capabilities() & QgsRasterDataProvider::ExactResolution ) )
    {
      double xRes = extent.width() / width;
      double providerXRes = provider->extent().width() / provider->xSize();
      double pixelRatio = xRes / providerXRes;
      oversampling = ( pixelRatio > mMaxOversampling ) ? mMaxOversampling : pixelRatio;
      QgsDebugMsg( QString( "xRes = %1 providerXRes = %2 pixelRatio = %3 oversampling = %4" ).arg( xRes ).arg( providerXRes ).arg( pixelRatio ).arg( oversampling ) );
    }
  }

  //set oversampling back to 1.0 if no resampler for zoomed in / zoomed out (nearest neighbour)
  if (( oversampling < 1.0 && !mZoomedInResampler ) || ( oversampling > 1.0 && !mZoomedOutResampler ) )
  {
    oversampling = 1.0;
  }

  QgsDebugMsg( QString( "oversampling %1" ).arg( oversampling ) );

  //effective oversampling factors are different to global one because of rounding
  double oversamplingX = (( double )width * oversampling ) / width;
  double oversamplingY = (( double )height * oversampling ) / height;

  // TODO: we must also increase the extent to get correct result on borders of parts

  int resWidth = width * oversamplingX;
  int resHeight = height * oversamplingY;

  // At moment we know that we read rendered image
  int bandNumber = 1;
  //void *rasterData = mInput->block( bandNumber, extent, resWidth, resHeight );
  QgsRasterBlock *inputBlock = mInput->block( bandNumber, extent, resWidth, resHeight );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  if ( doubleNear( oversamplingX, 1.0 ) || doubleNear( oversamplingY, 1.0 ) )
  {
    QgsDebugMsg( "No oversampling." );
    delete outputBlock;
    return inputBlock;
  }

  if ( !outputBlock->reset( QgsRasterBlock::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    return outputBlock;
  }

  //resample image
  QImage img = inputBlock->image();

  QImage dstImg = QImage( width, height, QImage::Format_ARGB32_Premultiplied );

  if ( mZoomedInResampler && oversamplingX < 1.0 )
  {
    QgsDebugMsg( "zoomed in resampling" );
    mZoomedInResampler->resample( img, dstImg );
  }
  else if ( mZoomedOutResampler && oversamplingX > 1.0 )
  {
    QgsDebugMsg( "zoomed out resampling" );
    mZoomedOutResampler->resample( img, dstImg );
  }
  else
  {
    // Should not happen
    QgsDebugMsg( "Unexpected resampling" );
    dstImg = img.scaled( width, height );
  }

  outputBlock->setImage( &dstImg );

  delete inputBlock;
  return outputBlock; // No resampling
}
Example #10
0
QgsRasterBlock * QgsRasterProjector::block( int bandNo, QgsRectangle  const & extent, int width, int height )
{
  QgsDebugMsg( QString( "extent:\n%1" ).arg( extent.toString() ) );
  QgsDebugMsg( QString( "width = %1 height = %2" ).arg( width ).arg( height ) );
  if ( !mInput )
  {
    QgsDebugMsg( "Input not set" );
    return new QgsRasterBlock();
  }

  if ( ! mSrcCRS.isValid() || ! mDestCRS.isValid() || mSrcCRS == mDestCRS )
  {
    QgsDebugMsg( "No projection necessary" );
    return mInput->block( bandNo, extent, width, height );
  }

  mDestExtent = extent;
  mDestRows = height;
  mDestCols = width;
  calc();

  QgsDebugMsg( QString( "srcExtent:\n%1" ).arg( srcExtent().toString() ) );
  QgsDebugMsg( QString( "srcCols = %1 srcRows = %2" ).arg( srcCols() ).arg( srcRows() ) );

  // If we zoom out too much, projector srcRows / srcCols maybe 0, which can cause problems in providers
  if ( srcRows() <= 0 || srcCols() <= 0 )
  {
    QgsDebugMsg( "Zero srcRows or srcCols" );
    return new QgsRasterBlock();
  }

  QgsRasterBlock *inputBlock = mInput->block( bandNo, srcExtent(), srcCols(), srcRows() );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return new QgsRasterBlock();
  }

  qgssize pixelSize = QgsRasterBlock::typeSize( mInput->dataType( bandNo ) );

  QgsRasterBlock *outputBlock;
  if ( inputBlock->hasNoDataValue() )
  {
    outputBlock = new QgsRasterBlock( inputBlock->dataType(), width, height, inputBlock->noDataValue() );
  }
  else
  {
    outputBlock = new QgsRasterBlock( inputBlock->dataType(), width, height );
  }
  if ( !outputBlock->isValid() )
  {
    QgsDebugMsg( "Cannot create block" );
    delete inputBlock;
    return outputBlock;
  }

  // set output to no data, it should be fast
  outputBlock->setIsNoData();

  // No data: because isNoData()/setIsNoData() is slow with respect to simple memcpy,
  // we use if only if necessary:
  // 1) no data value exists (numerical) -> memcpy, not necessary isNoData()/setIsNoData()
  // 2) no data value does not exist but it may contain no data (numerical no data bitmap)
  //    -> must use isNoData()/setIsNoData()
  // 3) no data are not used (no no data value, no no data bitmap) -> simple memcpy
  // 4) image - simple memcpy

  // To copy no data values stored in bitmaps we have to use isNoData()/setIsNoData(),
  // we cannot fill output block with no data because we use memcpy for data, not setValue().
  bool doNoData = !QgsRasterBlock::typeIsNumeric( inputBlock->dataType() ) && inputBlock->hasNoData() && !inputBlock->hasNoDataValue();

  const QgsCoordinateTransform* inverseCt = nullptr;
  if ( !mApproximate )
  {
    inverseCt = QgsCoordinateTransformCache::instance()->transform( mDestCRS.authid(), mSrcCRS.authid(), mDestDatumTransform, mSrcDatumTransform );
  }

  outputBlock->setIsNoData();

  int srcRow, srcCol;
  for ( int i = 0; i < height; ++i )
  {
    for ( int j = 0; j < width; ++j )
    {
      bool inside = srcRowCol( i, j, &srcRow, &srcCol, inverseCt );
      if ( !inside ) continue; // we have everything set to no data

      qgssize srcIndex = ( qgssize )srcRow * mSrcCols + srcCol;
      QgsDebugMsgLevel( QString( "row = %1 col = %2 srcRow = %3 srcCol = %4" ).arg( i ).arg( j ).arg( srcRow ).arg( srcCol ), 5 );

      // isNoData() may be slow so we check doNoData first
      if ( doNoData && inputBlock->isNoData( srcRow, srcCol ) )
      {
        outputBlock->setIsNoData( i, j );
        continue;
      }

      qgssize destIndex = ( qgssize )i * width + j;
      char *srcBits = inputBlock->bits( srcIndex );
      char *destBits = outputBlock->bits( destIndex );
      if ( !srcBits )
      {
        QgsDebugMsg( QString( "Cannot get input block data: row = %1 col = %2" ).arg( i ).arg( j ) );
        continue;
      }
      if ( !destBits )
      {
        QgsDebugMsg( QString( "Cannot set output block data: srcRow = %1 srcCol = %2" ).arg( srcRow ).arg( srcCol ) );
        continue;
      }
      memcpy( destBits, srcBits, pixelSize );
      outputBlock->setIsData( i, j );
    }
  }

  delete inputBlock;

  return outputBlock;
}
int QgsRasterCalculator::processCalculation( QProgressDialog* p )
{
  //prepare search string / tree
  QString errorString;
  QgsRasterCalcNode* calcNode = QgsRasterCalcNode::parseRasterCalcString( mFormulaString, errorString );
  if ( !calcNode )
  {
    //error
    return static_cast<int>( ParserError );
  }

  QMap< QString, QgsRasterBlock* > inputBlocks;
  QVector<QgsRasterCalculatorEntry>::const_iterator it = mRasterEntries.constBegin();
  for ( ; it != mRasterEntries.constEnd(); ++it )
  {
    if ( !it->raster ) // no raster layer in entry
    {
      delete calcNode;
      qDeleteAll( inputBlocks );
      return static_cast< int >( InputLayerError );
    }

    QgsRasterBlock* block = nullptr;
    // if crs transform needed
    if ( it->raster->crs() != mOutputCrs )
    {
      QgsRasterProjector proj;
      proj.setCRS( it->raster->crs(), mOutputCrs );
      proj.setInput( it->raster->dataProvider() );
      proj.setPrecision( QgsRasterProjector::Exact );

      block = proj.block( it->bandNumber, mOutputRectangle, mNumOutputColumns, mNumOutputRows );
    }
    else
    {
      block = it->raster->dataProvider()->block( it->bandNumber, mOutputRectangle, mNumOutputColumns, mNumOutputRows );
    }
    if ( block->isEmpty() )
    {
      delete block;
      delete calcNode;
      qDeleteAll( inputBlocks );
      return static_cast<int>( MemoryError );
    }
    inputBlocks.insert( it->ref, block );
  }

  //open output dataset for writing
  GDALDriverH outputDriver = openOutputDriver();
  if ( !outputDriver )
  {
    return static_cast< int >( CreateOutputError );
  }

  GDALDatasetH outputDataset = openOutputFile( outputDriver );
  GDALSetProjection( outputDataset, mOutputCrs.toWkt().toLocal8Bit().data() );
  GDALRasterBandH outputRasterBand = GDALGetRasterBand( outputDataset, 1 );

  float outputNodataValue = -FLT_MAX;
  GDALSetRasterNoDataValue( outputRasterBand, outputNodataValue );

  if ( p )
  {
    p->setMaximum( mNumOutputRows );
  }

  QgsRasterMatrix resultMatrix;
  resultMatrix.setNodataValue( outputNodataValue );

  //read / write line by line
  for ( int i = 0; i < mNumOutputRows; ++i )
  {
    if ( p )
    {
      p->setValue( i );
    }

    if ( p && p->wasCanceled() )
    {
      break;
    }

    if ( calcNode->calculate( inputBlocks, resultMatrix, i ) )
    {
      bool resultIsNumber = resultMatrix.isNumber();
      float* calcData = new float[mNumOutputColumns];

      for ( int j = 0; j < mNumOutputColumns; ++j )
      {
        calcData[j] = ( float )( resultIsNumber ? resultMatrix.number() : resultMatrix.data()[j] );
      }

      //write scanline to the dataset
      if ( GDALRasterIO( outputRasterBand, GF_Write, 0, i, mNumOutputColumns, 1, calcData, mNumOutputColumns, 1, GDT_Float32, 0, 0 ) != CE_None )
      {
        qWarning( "RasterIO error!" );
      }

      delete[] calcData;
    }

  }

  if ( p )
  {
    p->setValue( mNumOutputRows );
  }

  //close datasets and release memory
  delete calcNode;
  qDeleteAll( inputBlocks );
  inputBlocks.clear();

  if ( p && p->wasCanceled() )
  {
    //delete the dataset without closing (because it is faster)
    GDALDeleteDataset( outputDriver, TO8F( mOutputFile ) );
    return static_cast< int >( Cancelled );
  }
  GDALClose( outputDataset );

  return static_cast< int >( Success );
}
Example #12
0
QgsRasterBlock * QgsHueSaturationFilter::block( int bandNo, QgsRectangle  const & extent, int width, int height, QgsRasterBlockFeedback* feedback )
{
  Q_UNUSED( bandNo );
  QgsDebugMsgLevel( QString( "width = %1 height = %2 extent = %3" ).arg( width ).arg( height ).arg( extent.toString() ), 4 );

  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput )
  {
    return outputBlock;
  }

  // At this moment we know that we read rendered image
  int bandNumber = 1;
  QgsRasterBlock *inputBlock = mInput->block( bandNumber, extent, width, height, feedback );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  if ( mSaturation == 0 && mGrayscaleMode == GrayscaleOff && !mColorizeOn )
  {
    QgsDebugMsgLevel( "No hue/saturation change.", 4 );
    delete outputBlock;
    return inputBlock;
  }

  if ( !outputBlock->reset( Qgis::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    return outputBlock;
  }

  // adjust image
  QRgb myNoDataColor = qRgba( 0, 0, 0, 0 );
  QRgb myRgb;
  QColor myColor;
  int h, s, l;
  int r, g, b, alpha;
  double alphaFactor = 1.0;

  for ( qgssize i = 0; i < ( qgssize )width*height; i++ )
  {
    if ( inputBlock->color( i ) == myNoDataColor )
    {
      outputBlock->setColor( i, myNoDataColor );
      continue;
    }

    myRgb = inputBlock->color( i );
    myColor = QColor( myRgb );

    // Alpha must be taken from QRgb, since conversion from QRgb->QColor loses alpha
    alpha = qAlpha( myRgb );

    if ( alpha == 0 )
    {
      // totally transparent, no changes required
      outputBlock->setColor( i, myRgb );
      continue;
    }

    // Get rgb for color
    myColor.getRgb( &r, &g, &b );
    if ( alpha != 255 )
    {
      // Semi-transparent pixel. We need to adjust the colors since we are using Qgis::ARGB32_Premultiplied
      // and color values have been premultiplied by alpha
      alphaFactor = alpha / 255.;
      r /= alphaFactor;
      g /= alphaFactor;
      b /= alphaFactor;
      myColor = QColor::fromRgb( r, g, b );
    }

    myColor.getHsl( &h, &s, &l );

    // Changing saturation?
    if (( mGrayscaleMode != GrayscaleOff ) || ( mSaturationScale != 1 ) )
    {
      processSaturation( r, g, b, h, s, l );
    }

    // Colorizing?
    if ( mColorizeOn )
    {
      processColorization( r, g, b, h, s, l );
    }

    // Convert back to rgb
    if ( alpha != 255 )
    {
      // Transparent pixel, need to premultiply color components
      r *= alphaFactor;
      g *= alphaFactor;
      b *= alphaFactor;
    }

    outputBlock->setColor( i, qRgba( r, g, b, alpha ) );
  }

  delete inputBlock;
  return outputBlock;
}
QgsRasterBlock * QgsBrightnessContrastFilter::block( int bandNo, QgsRectangle  const & extent, int width, int height )
{
  Q_UNUSED( bandNo );
  QgsDebugMsg( QString( "width = %1 height = %2 extent = %3" ).arg( width ).arg( height ).arg( extent.toString() ) );

  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput )
  {
    return outputBlock;
  }

  // At this moment we know that we read rendered image
  int bandNumber = 1;
  QgsRasterBlock *inputBlock = mInput->block( bandNumber, extent, width, height );
  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  if ( mBrightness == 0 && mContrast == 0 )
  {
    QgsDebugMsg( "No brightness changes." );
    delete outputBlock;
    return inputBlock;
  }

  if ( !outputBlock->reset( QGis::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    return outputBlock;
  }

  // adjust image
  QRgb myNoDataColor = qRgba( 0, 0, 0, 0 );
  QRgb myColor;

  int r, g, b, alpha;
  double f = qPow(( mContrast + 100 ) / 100.0, 2 );

  for ( qgssize i = 0; i < ( qgssize )width*height; i++ )
  {
    if ( inputBlock->color( i ) == myNoDataColor )
    {
      outputBlock->setColor( i, myNoDataColor );
      continue;
    }

    myColor = inputBlock->color( i );
    alpha = qAlpha( myColor );

    r = adjustColorComponent( qRed( myColor ), alpha, mBrightness, f );
    g = adjustColorComponent( qGreen( myColor ), alpha, mBrightness, f );
    b = adjustColorComponent( qBlue( myColor ), alpha, mBrightness, f );

    outputBlock->setColor( i, qRgba( r, g, b, alpha ) );
  }

  delete inputBlock;
  return outputBlock;
}
Example #14
0
QgsRasterBlock *QgsHillshadeRenderer::block( int bandNo, const QgsRectangle &extent, int width, int height )
{
  Q_UNUSED( bandNo );
  QgsRasterBlock *outputBlock = new QgsRasterBlock();
  if ( !mInput )
  {
    QgsDebugMsg( "No input raster!" );
    return outputBlock;
  }

  QgsRasterBlock *inputBlock = mInput->block( mBand, extent, width, height );

  if ( !inputBlock || inputBlock->isEmpty() )
  {
    QgsDebugMsg( "No raster data!" );
    delete inputBlock;
    return outputBlock;
  }

  if ( !outputBlock->reset( QGis::ARGB32_Premultiplied, width, height ) )
  {
    delete inputBlock;
    return outputBlock;
  }

  double cellXSize = extent.width() / double( width );
  double cellYSize = extent.height() / double( height );
  double zenithRad = qMax( 0.0, 90 - mLightAngle ) * M_PI / 180.0;
  double azimuthRad = -1 * mLightAzimuth * M_PI / 180.0;
  double cosZenithRad = cos( zenithRad );
  double sinZenithRad = sin( zenithRad );

  QRgb myDefaultColor = NODATA_COLOR;

  for ( qgssize i = 0; i < ( qgssize )height; i++ )
  {

    for ( qgssize j = 0; j < ( qgssize )width; j++ )
    {

      if ( inputBlock->isNoData( i, j ) )
      {
        outputBlock->setColor( i, j, myDefaultColor );
        continue;
      }

      qgssize iUp, iDown, jLeft, jRight;
      if ( i == 0 )
      {
        iUp = i;
        iDown = i + 1;
      }
      else if ( i < ( qgssize )height - 1 )
      {
        iUp = i - 1;
        iDown = i + 1;
      }
      else
      {
        iUp = i - 1;
        iDown = i;
      }

      if ( j == 0 )
      {
        jLeft = j;
        jRight = j + 1;
      }
      else if ( j < ( qgssize )width - 1 )
      {
        jLeft = j - 1;
        jRight = j + 1;
      }
      else
      {
        jLeft = j - 1;
        jRight = j;
      }

      double x11;
      double x21;
      double x31;
      double x12;
      double x22; // Working cell
      double x32;
      double x13;
      double x23;
      double x33;

      // This is center cell. It is not nodata. Use this in place of nodata neighbors
      x22 = inputBlock->value( i, j );

      x11 = inputBlock->isNoData( iUp, jLeft )  ? x22 : inputBlock->value( iUp, jLeft );
      x21 = inputBlock->isNoData( i, jLeft )     ? x22 : inputBlock->value( i, jLeft );
      x31 = inputBlock->isNoData( iDown, jLeft ) ? x22 : inputBlock->value( iDown, jLeft );

      x12 = inputBlock->isNoData( iUp, j )       ? x22 : inputBlock->value( iUp, j );
      // x22
      x32 = inputBlock->isNoData( iDown, j )     ? x22 : inputBlock->value( iDown, j );

      x13 = inputBlock->isNoData( iUp, jRight )   ? x22 : inputBlock->value( iUp, jRight );
      x23 = inputBlock->isNoData( i, jRight )     ? x22 : inputBlock->value( i, jRight );
      x33 = inputBlock->isNoData( iDown, jRight ) ? x22 : inputBlock->value( iDown, jRight );

      double derX = calcFirstDerX( x11, x21, x31, x12, x22, x32, x13, x23, x33, cellXSize );
      double derY = calcFirstDerY( x11, x21, x31, x12, x22, x32, x13, x23, x33, cellYSize );

      double slope_rad = atan( mZFactor * sqrt( derX * derX + derY * derY ) );
      double aspectRad = atan2( derX, -derY );

      double colorvalue = qBound( 0.0, 255.0 * (( cosZenithRad * cos( slope_rad ) ) +
                                  ( sinZenithRad * sin( slope_rad ) *
                                    cos( azimuthRad - aspectRad ) ) ), 255.0 );

      outputBlock->setColor( i, j, qRgb( colorvalue, colorvalue, colorvalue ) );
    }
  }
  return outputBlock;
}
QgsRasterBlock * QgsRasterDataProvider::block( int theBandNo, QgsRectangle  const & theExtent, int theWidth, int theHeight )
{
  QgsDebugMsg( QString( "theBandNo = %1 theWidth = %2 theHeight = %3" ).arg( theBandNo ).arg( theWidth ).arg( theHeight ) );
  QgsDebugMsg( QString( "theExtent = %1" ).arg( theExtent.toString() ) );

  QgsRasterBlock *block = new QgsRasterBlock( dataType( theBandNo ), theWidth, theHeight, noDataValue( theBandNo ) );

  if ( block->isEmpty() )
  {
    QgsDebugMsg( "Couldn't create raster block" );
    return block;
  }

  // Read necessary extent only
  QgsRectangle tmpExtent = extent().intersect( &theExtent );

  if ( tmpExtent.isEmpty() )
  {
    QgsDebugMsg( "Extent outside provider extent" );
    block->setIsNoData();
    return block;
  }

  double xRes = theExtent.width() / theWidth;
  double yRes = theExtent.height() / theHeight;
  double tmpXRes, tmpYRes;
  double providerXRes = 0;
  double providerYRes = 0;
  if ( capabilities() & ExactResolution )
  {
    providerXRes = extent().width() / xSize();
    providerYRes = extent().height() / ySize();
    tmpXRes = qMax( providerXRes, xRes );
    tmpYRes = qMax( providerYRes, yRes );
    if ( doubleNear( tmpXRes, xRes ) ) tmpXRes = xRes;
    if ( doubleNear( tmpYRes, yRes ) ) tmpYRes = yRes;
  }
  else
  {
    tmpXRes = xRes;
    tmpYRes = yRes;
  }

  if ( tmpExtent != theExtent ||
       tmpXRes > xRes || tmpYRes > yRes )
  {
    // Read smaller extent or lower resolution

    // Calculate row/col limits (before tmpExtent is aligned)
    int fromRow = qRound(( theExtent.yMaximum() - tmpExtent.yMaximum() ) / yRes );
    int toRow = qRound(( theExtent.yMaximum() - tmpExtent.yMinimum() ) / yRes ) - 1;
    int fromCol = qRound(( tmpExtent.xMinimum() - theExtent.xMinimum() ) / xRes ) ;
    int toCol = qRound(( tmpExtent.xMaximum() - theExtent.xMinimum() ) / xRes ) - 1;

    QgsDebugMsg( QString( "fromRow = %1 toRow = %2 fromCol = %3 toCol = %4" ).arg( fromRow ).arg( toRow ).arg( fromCol ).arg( toCol ) );

    if ( fromRow < 0 || fromRow >= theHeight || toRow < 0 || toRow >= theHeight ||
         fromCol < 0 || fromCol >= theWidth || toCol < 0 || toCol >= theWidth )
    {
      // Should not happen
      QgsDebugMsg( "Row or column limits out of range" );
      return block;
    }

    // If lower source resolution is used, the extent must beS aligned to original
    // resolution to avoid possible shift due to resampling
    if ( tmpXRes > xRes )
    {
      int col = floor(( tmpExtent.xMinimum() - extent().xMinimum() ) / providerXRes );
      tmpExtent.setXMinimum( extent().xMinimum() + col * providerXRes );
      col = ceil(( tmpExtent.xMaximum() - extent().xMinimum() ) / providerXRes );
      tmpExtent.setXMaximum( extent().xMinimum() + col * providerXRes );
    }
    if ( tmpYRes > yRes )
    {
      int row = floor(( extent().yMaximum() - tmpExtent.yMaximum() ) / providerYRes );
      tmpExtent.setYMaximum( extent().yMaximum() - row * providerYRes );
      row = ceil(( extent().yMaximum() - tmpExtent.yMinimum() ) / providerYRes );
      tmpExtent.setYMinimum( extent().yMaximum() - row * providerYRes );
    }
    int tmpWidth = qRound( tmpExtent.width() / tmpXRes );
    int tmpHeight = qRound( tmpExtent.height() / tmpYRes );
    tmpXRes = tmpExtent.width() / tmpWidth;
    tmpYRes = tmpExtent.height() / tmpHeight;

    QgsDebugMsg( QString( "Reading smaller block tmpWidth = %1 theHeight = %2" ).arg( tmpWidth ).arg( tmpHeight ) );
    QgsDebugMsg( QString( "tmpExtent = %1" ).arg( tmpExtent.toString() ) );

    block->setIsNoData();

    QgsRasterBlock *tmpBlock = new QgsRasterBlock( dataType( theBandNo ), tmpWidth, tmpHeight, noDataValue( theBandNo ) );

    readBlock( theBandNo, tmpExtent, tmpWidth, tmpHeight, tmpBlock->data() );

    int pixelSize = dataTypeSize( theBandNo );

    double xMin = theExtent.xMinimum();
    double yMax = theExtent.yMaximum();
    double tmpXMin = tmpExtent.xMinimum();
    double tmpYMax = tmpExtent.yMaximum();

    for ( int row = fromRow; row <= toRow; row++ )
    {
      double y = yMax - ( row + 0.5 ) * yRes;
      int tmpRow = floor(( tmpYMax - y ) / tmpYRes );

      for ( int col = fromCol; col <= toCol; col++ )
      {
        double x = xMin + ( col + 0.5 ) * xRes;
        int tmpCol = floor(( x - tmpXMin ) / tmpXRes );

        if ( tmpRow < 0 || tmpRow >= tmpHeight || tmpCol < 0 || tmpCol >= tmpWidth )
        {
          QgsDebugMsg( "Source row or column limits out of range" );
          block->setIsNoData(); // so that the problem becomes obvious and fixed
          delete tmpBlock;
          return block;
        }

        size_t tmpIndex = tmpRow * tmpWidth + tmpCol;
        size_t index = row * theWidth + col;

        char *tmpBits = tmpBlock->bits( tmpIndex );
        char *bits = block->bits( index );
        if ( !tmpBits )
        {
          QgsDebugMsg( QString( "Cannot get input block data tmpRow = %1 tmpCol = %2 tmpIndex = %3." ).arg( tmpRow ).arg( tmpCol ).arg( tmpIndex ) );
          continue;
        }
        if ( !bits )
        {
          QgsDebugMsg( "Cannot set output block data." );
          continue;
        }
        memcpy( bits, tmpBits, pixelSize );
      }
    }

    delete tmpBlock;
  }
  else
  {
    readBlock( theBandNo, theExtent, theWidth, theHeight, block->data() );
  }

  // apply user no data values
  // TODO: there are other readBlock methods where no data are not applied
  block->applyNodataValues( userNoDataValue( theBandNo ) );
  return block;
}