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 * 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
}
