Possibility to set resampling modes differently for zoomed-in and zoo…

…med-out

src/app/qgsrasterlayerproperties.cpp

@@ -27,6 +27,7 @@
 #include "qgscubicrasterresampler.h"
 #include "qgscoordinatetransform.h"
 #include "qgsrasterlayerproperties.h"
+#include "qgsrasterrenderer.h"
 #include "qgsgenericprojectionselector.h"
 #include "qgsproject.h"
 #include "qgsrasterbandstats.h"
@@ -288,20 +289,45 @@ QgsRasterLayerProperties::QgsRasterLayerProperties( QgsMapLayer* lyr, QgsMapCanv
   tableTransparency->horizontalHeader()->setResizeMode( 1, QHeaderView::Stretch );
 
   //resampling
-  const QgsRasterResampler* resampler = mRasterLayer->resampler();
-  if ( !resampler )
+  const QgsRasterRenderer* renderer = mRasterLayer->renderer();
+  mZoomedInResamplingComboBox->insertItem( 0, tr( "Nearest neighbour" ) );
+  mZoomedInResamplingComboBox->insertItem( 1, tr( "Bilinear" ) );
+  mZoomedInResamplingComboBox->insertItem( 2, tr( "Cubic" ) );
+  mZoomedOutResamplingComboBox->insertItem( 0, tr( "Nearest neighbour" ) );
+  mZoomedOutResamplingComboBox->insertItem( 1, tr( "Average" ) );
+  //set combo boxes to current resampling types
+  if ( renderer )
   {
-    mNearestNeighbourRadioButton->setChecked( true );
-  }
-  else if ( resampler->type() == "bilinear" )
-  {
-    mBilinearRadioButton->setChecked( true );
-  }
-  else if ( resampler->type() == "cubic" )
-  {
-    mCubicRadioButton->setChecked( true );
-  }
+    const QgsRasterResampler* zoomedInResampler = renderer->zoomedInResampler();
+    if ( zoomedInResampler )
+    {
+      if ( zoomedInResampler->type() == "bilinear" )
+      {
+        mZoomedInResamplingComboBox->setCurrentIndex( 1 );
+      }
+      else if ( zoomedInResampler->type() == "cubic" )
+      {
+        mZoomedInResamplingComboBox->setCurrentIndex( 2 );
+      }
+    }
+    else
+    {
+      mZoomedInResamplingComboBox->setCurrentIndex( 0 );
+    }
 
+    const QgsRasterResampler* zoomedOutResampler = renderer->zoomedOutResampler();
+    if ( zoomedOutResampler )
+    {
+      if ( zoomedOutResampler->type() == "bilinear" ) //bilinear resampler does averaging when zooming out
+      {
+        mZoomedOutResamplingComboBox->setCurrentIndex( 1 );
+      }
+    }
+    else
+    {
+      mZoomedOutResamplingComboBox->setCurrentIndex( 0 );
+    }
+  }
 } // QgsRasterLayerProperties ctor
 
 
@@ -1370,20 +1396,6 @@ void QgsRasterLayerProperties::apply()
   pixmapLegend->setScaledContents( true );
   pixmapLegend->repaint();
 
-  //resampling
-  if ( mNearestNeighbourRadioButton->isChecked() )
-  {
-    mRasterLayer->setResampler( 0 );
-  }
-  else if ( mBilinearRadioButton->isChecked() )
-  {
-    mRasterLayer->setResampler( new QgsBilinearRasterResampler() );
-  }
-  else if ( mCubicRadioButton->isChecked() )
-  {
-    mRasterLayer->setResampler( new QgsCubicRasterResampler() );
-  }
-
   //set the appropriate render style
   if ( rbtnSingleBand->isChecked() )
   {
@@ -1478,6 +1490,36 @@ void QgsRasterLayerProperties::apply()
   //set render style finished
 
 
+  //resampling
+  QgsRasterRenderer* rasterRenderer = mRasterLayer->renderer();
+  QgsRasterResampler* zoomedInResampler = 0;
+  QString zoomedInResamplingMethod = mZoomedInResamplingComboBox->currentText();
+  if ( zoomedInResamplingMethod == tr( "Bilinear" ) )
+  {
+    zoomedInResampler = new QgsBilinearRasterResampler();
+  }
+  else if ( zoomedInResamplingMethod == tr( "Cubic" ) )
+  {
+    zoomedInResampler = new QgsCubicRasterResampler();
+  }
+
+  if ( rasterRenderer )
+  {
+    rasterRenderer->setZoomedInResampler( zoomedInResampler );
+  }
+
+  QgsRasterResampler* zoomedOutResampler = 0;
+  QString zoomedOutResamplingMethod = mZoomedOutResamplingComboBox->currentText();
+  if ( zoomedOutResamplingMethod == tr( "Average" ) )
+  {
+    zoomedOutResampler = new QgsBilinearRasterResampler();
+  }
+
+  if ( rasterRenderer )
+  {
+    rasterRenderer->setZoomedOutResampler( zoomedOutResampler );
+  }
+
 
   //get the thumbnail for the layer
   QPixmap myQPixmap = QPixmap( pixmapThumbnail->width(), pixmapThumbnail->height() );

src/core/raster/qgsmultibandcolorrenderer.cpp

@@ -20,8 +20,8 @@
 #include <QImage>
 #include <QSet>
 
-QgsMultiBandColorRenderer::QgsMultiBandColorRenderer( QgsRasterDataProvider* provider, int redBand, int greenBand, int blueBand, QgsRasterResampler* resampler ):
-    QgsRasterRenderer( provider, resampler ), mRedBand( redBand ), mGreenBand( greenBand ), mBlueBand( blueBand ), mContrastEnhancement( 0 )
+QgsMultiBandColorRenderer::QgsMultiBandColorRenderer( QgsRasterDataProvider* provider, int redBand, int greenBand, int blueBand ):
+    QgsRasterRenderer( provider ), mRedBand( redBand ), mGreenBand( greenBand ), mBlueBand( blueBand ), mContrastEnhancement( 0 )
 {
 }
 

src/core/raster/qgsmultibandcolorrenderer.h

@@ -26,7 +26,7 @@ class QgsContrastEnhancement;
 class QgsMultiBandColorRenderer: public QgsRasterRenderer
 {
   public:
-    QgsMultiBandColorRenderer( QgsRasterDataProvider* provider, int redBand, int greenBand, int blueBand, QgsRasterResampler* resampler = 0 );
+    QgsMultiBandColorRenderer( QgsRasterDataProvider* provider, int redBand, int greenBand, int blueBand );
     ~QgsMultiBandColorRenderer();
 
     void draw( QPainter* p, QgsRasterViewPort* viewPort, const QgsMapToPixel* theQgsMapToPixel );

src/core/raster/qgspalettedrasterrenderer.cpp

@@ -22,8 +22,8 @@
 #include <QImage>
 
 QgsPalettedRasterRenderer::QgsPalettedRasterRenderer( QgsRasterDataProvider* provider, int bandNumber,
-    QColor* colorArray, int nColors, QgsRasterResampler* resampler ):
-    QgsRasterRenderer( provider, resampler ), mBandNumber( bandNumber ), mColors( colorArray ), mNColors( nColors )
+    QColor* colorArray, int nColors ):
+    QgsRasterRenderer( provider ), mBandNumber( bandNumber ), mColors( colorArray ), mNColors( nColors )
 {
 }
 

src/core/raster/qgspalettedrasterrenderer.h

@@ -26,7 +26,7 @@ class QgsPalettedRasterRenderer: public QgsRasterRenderer
 {
   public:
     /**Renderer owns color array*/
-    QgsPalettedRasterRenderer( QgsRasterDataProvider* provider, int bandNumber, QColor* colorArray, int nColors, QgsRasterResampler* resampler = 0 );
+    QgsPalettedRasterRenderer( QgsRasterDataProvider* provider, int bandNumber, QColor* colorArray, int nColors );
     ~QgsPalettedRasterRenderer();
     void draw( QPainter* p, QgsRasterViewPort* viewPort, const QgsMapToPixel* theQgsMapToPixel );
 

src/core/raster/qgsrasterlayer.cpp

@@ -38,8 +38,6 @@ email                : tim at linfiniti.com
 
 //renderers
 #include "qgspalettedrasterrenderer.h"
-#include "qgsbilinearrasterresampler.h"
-#include "qgscubicrasterresampler.h"
 #include "qgsmultibandcolorrenderer.h"
 #include "qgssinglebandcolordatarenderer.h"
 #include "qgssinglebandpseudocolorrenderer.h"
@@ -103,7 +101,6 @@ QgsRasterLayer::QgsRasterLayer(
     , mWidth( std::numeric_limits<int>::max() )
     , mHeight( std::numeric_limits<int>::max() )
     , mInvertColor( false )
-    , mResampler( 0 )
     , mRenderer( 0 )
 {
   QgsDebugMsg( "Entered" );
@@ -153,7 +150,6 @@ QgsRasterLayer::QgsRasterLayer( int dummy,
     , mStyles( styles )
     , mFormat( format )
     , mCrs( crs )
-    , mResampler( 0 )
     , mRenderer( 0 )
 {
   Q_UNUSED( dummy );
@@ -192,7 +188,6 @@ QgsRasterLayer::~QgsRasterLayer()
   mValid = false;
   delete mRasterShader;
   delete mDataProvider;
-  delete mResampler;
   delete mRenderer;
 }
 
@@ -610,15 +605,14 @@ void QgsRasterLayer::setRendererForDrawingStyle( const DrawingStyle &  theDrawin
       renderer = new QgsPalettedRasterRenderer( mDataProvider,
           grayBand,
           colorArray,
-          itemList.size(),
-          mResampler );
+          itemList.size() );
       break;
     }
     case MultiBandSingleBandGray:
     case SingleBandGray:
     {
       int grayBand = bandNumber( mGrayBandName );
-      renderer = new QgsSingleBandGrayRenderer( mDataProvider, grayBand, mResampler );
+      renderer = new QgsSingleBandGrayRenderer( mDataProvider, grayBand );
       if ( QgsContrastEnhancement::NoEnhancement != contrastEnhancementAlgorithm() && !mUserDefinedGrayMinimumMaximum && mStandardDeviations > 0 )
       {
         mGrayMinimumMaximumEstimated = false;
@@ -656,20 +650,20 @@ void QgsRasterLayer::setRendererForDrawingStyle( const DrawingStyle &  theDrawin
       mRasterShader->setMinimumValue( myMinimumValue );
       mRasterShader->setMaximumValue( myMaximumValue );
 
-      renderer = new QgsSingleBandPseudoColorRenderer( mDataProvider, bandNo, mRasterShader, mResampler );
+      renderer = new QgsSingleBandPseudoColorRenderer( mDataProvider, bandNo, mRasterShader );
       break;
     }
     case MultiBandColor:
     {
       int red = bandNumber( mRedBandName );
       int green = bandNumber( mGreenBandName );
       int blue = bandNumber( mBlueBandName );
-      renderer = new QgsMultiBandColorRenderer( mDataProvider, red, green, blue, mResampler );
+      renderer = new QgsMultiBandColorRenderer( mDataProvider, red, green, blue );
       break;
     }
     case SingleBandColorDataStyle:
     {
-      renderer = new QgsSingleBandColorDataRenderer( mDataProvider, bandNumber( mGrayBandName ), mResampler );
+      renderer = new QgsSingleBandColorDataRenderer( mDataProvider, bandNumber( mGrayBandName ) );
       break;
     }
     default:
@@ -2802,12 +2796,6 @@ void QgsRasterLayer::setTransparentBandName( QString const & theBandName )
   mTransparencyBandName = validateBandName( theBandName );
 }
 
-void QgsRasterLayer::setResampler( QgsRasterResampler* resampler )
-{
-  delete mResampler;
-  mResampler = resampler;
-}
-
 void QgsRasterLayer::setRenderer( QgsRasterRenderer* renderer )
 {
   delete mRenderer;
@@ -2950,6 +2938,7 @@ bool QgsRasterLayer::readSymbology( const QDomNode& layer_node, QString& errorMe
   Q_UNUSED( errorMessage );
   QDomNode mnl = layer_node.namedItem( "rasterproperties" );
 
+#if 0
   //resampler
   QDomElement resamplerElem = mnl.firstChildElement( "resampler" );
   if ( !resamplerElem.isNull() )
@@ -2969,6 +2958,7 @@ bool QgsRasterLayer::readSymbology( const QDomNode& layer_node, QString& errorMe
       mResampler = 0;
     }
   }
+#endif //0
 
   QDomNode snode = mnl.namedItem( "mDrawingStyle" );
   QDomElement myElement = snode.toElement();
@@ -3287,12 +3277,14 @@ bool QgsRasterLayer::writeSymbology( QDomNode & layer_node, QDomDocument & docum
   QDomElement rasterPropertiesElement = document.createElement( "rasterproperties" );
   layer_node.appendChild( rasterPropertiesElement );
 
+#if 0
   // resampler
   QString resamplerName = mResampler ? mResampler->type() : "nearest neighbour";
   QDomElement resamplerElem = document.createElement( "resampler" );
   QDomText resamplerText = document.createTextNode( resamplerName );
   resamplerElem.appendChild( resamplerText );
   rasterPropertiesElement.appendChild( resamplerElem );
+#endif //0
 
   QStringList sl = subLayers();
   QStringList sls = mDataProvider->subLayerStyles();

src/core/raster/qgsrasterlayer.h

@@ -51,7 +51,6 @@ class QgsRectangle;
 class QgsRasterBandStats;
 class QgsRasterPyramid;
 class QgsRasterRenderer;
-class QgsRasterResampler;
 class QImage;
 class QPixmap;
 class QSlider;
@@ -393,14 +392,10 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     /** \brief Mutator for mUserDefinedRGBMinimumMaximum */
     void setUserDefinedRGBMinimumMaximum( bool theBool ) { mUserDefinedRGBMinimumMaximum = theBool; }
 
-    /** Set raster resampler. Uses nearest neighbour resampling per default. Takes ownership of the resampler object*/
-    void setResampler( QgsRasterResampler* resampler );
-    QgsRasterResampler* resampler() { return mResampler; }
-    const QgsRasterResampler* resampler() const { return mResampler; }
-
     /**Set raster renderer. Takes ownership of the renderer object*/
     void setRenderer( QgsRasterRenderer* renderer );
     const QgsRasterRenderer* renderer() const { return mRenderer; }
+    QgsRasterRenderer* renderer() { return mRenderer; }
 
     /** \brief Accessor to find out how many standard deviations are being plotted */
     double standardDeviations() const { return mStandardDeviations; }
@@ -940,7 +935,6 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     QString mFormat;
     QString mCrs;
 
-    QgsRasterResampler* mResampler;
     QgsRasterRenderer* mRenderer;
 };
 

src/core/raster/qgsrasterrenderer.cpp

@@ -23,7 +23,7 @@
 #include <QImage>
 #include <QPainter>
 
-QgsRasterRenderer::QgsRasterRenderer( QgsRasterDataProvider* provider, QgsRasterResampler* resampler ): mProvider( provider ), mResampler( resampler ),
+QgsRasterRenderer::QgsRasterRenderer( QgsRasterDataProvider* provider ): mProvider( provider ), mZoomedInResampler( 0 ), mZoomedOutResampler( 0 ),
     mOpacity( 1.0 ), mRasterTransparency( 0 ), mAlphaBand( -1 ), mInvertColor( false )
 {
 }
@@ -36,6 +36,21 @@ QgsRasterRenderer::~QgsRasterRenderer()
   {
     CPLFree( partIt.value().data );
   }
+
+  delete mZoomedInResampler;
+  delete mZoomedOutResampler;
+}
+
+void QgsRasterRenderer::setZoomedInResampler( QgsRasterResampler* r )
+{
+  delete mZoomedInResampler;
+  mZoomedInResampler = r;
+}
+
+void QgsRasterRenderer::setZoomedOutResampler( QgsRasterResampler* r )
+{
+  delete mZoomedOutResampler;
+  mZoomedOutResampler = r;
 }
 
 void QgsRasterRenderer::startRasterRead( int bandNumber, QgsRasterViewPort* viewPort, const QgsMapToPixel* mapToPixel, double& oversamplingX, double& oversamplingY )
@@ -50,7 +65,8 @@ void QgsRasterRenderer::startRasterRead( int bandNumber, QgsRasterViewPort* view
 
   //calculate oversampling factor
   double oversampling = 1.0; //approximate global oversampling factor
-  if ( mResampler )
+
+  if ( mZoomedInResampler || mZoomedOutResampler )
   {
     QgsRectangle providerExtent = mProvider->extent();
     if ( viewPort->mSrcCRS.isValid() && viewPort->mDestCRS.isValid() && viewPort->mSrcCRS != viewPort->mDestCRS )
@@ -62,6 +78,12 @@ void QgsRasterRenderer::startRasterRead( int bandNumber, QgsRasterViewPort* view
     oversampling = ( pixelRatio > 4.0 ) ? 4.0 : pixelRatio;
   }
 
+  //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;
+  }
+
   //split raster into small portions if necessary
   RasterPartInfo pInfo;
   pInfo.nCols = viewPort->drawableAreaXDim * oversampling;
@@ -178,13 +200,21 @@ void QgsRasterRenderer::drawImage( QPainter* p, QgsRasterViewPort* viewPort, con
 
   //top left position in device coords
   QPointF tlPoint = QPointF( viewPort->topLeftPoint.x(), viewPort->topLeftPoint.y() );
-  tlPoint += QPointF( topLeftCol / oversamplingX, topLeftRow / oversamplingY );
 
-  //draw image
-  if ( mResampler && !( doubleNear( oversamplingX, 1.0 ) && doubleNear( oversamplingY, 1.0 ) ) ) //resampling with factor 1.0 not useful
+  //resample and draw image
+  if (( mZoomedInResampler || mZoomedOutResampler ) && !doubleNear( oversamplingX, 1.0 ) && !doubleNear( oversamplingY, 1.0 ) )
   {
     QImage dstImg( nCols / oversamplingX + 1.0, nRows / oversamplingY + 1.0, QImage::Format_ARGB32_Premultiplied );
-    mResampler->resample( img, dstImg );
+    if ( mZoomedInResampler && oversamplingX < 1.0 )
+    {
+      mZoomedInResampler->resample( img, dstImg );
+    }
+    else if ( mZoomedOutResampler && oversamplingX > 1.0 )
+    {
+      mZoomedOutResampler->resample( img, dstImg );
+    }
+
+    tlPoint += QPointF( topLeftCol / oversamplingX, topLeftRow / oversamplingY );
     p->drawImage( tlPoint, dstImg );
   }
   else //use original image