Expose maxOversampling parameter to user

Author: mhugent

src/app/qgsrasterlayerproperties.cpp

@@ -327,6 +327,7 @@ QgsRasterLayerProperties::QgsRasterLayerProperties( QgsMapLayer* lyr, QgsMapCanv
     {
       mZoomedOutResamplingComboBox->setCurrentIndex( 0 );
     }
+    mMaximumOversamplingSpinBox->setValue( renderer->maxOversampling() );
   }
 } // QgsRasterLayerProperties ctor
 
@@ -1520,6 +1521,11 @@ void QgsRasterLayerProperties::apply()
     rasterRenderer->setZoomedOutResampler( zoomedOutResampler );
   }
 
+  if ( rasterRenderer )
+  {
+    rasterRenderer->setMaxOversampling( mMaximumOversamplingSpinBox->value() );
+  }
+
 
   //get the thumbnail for the layer
   QPixmap myQPixmap = QPixmap( pixmapThumbnail->width(), pixmapThumbnail->height() );

src/core/raster/qgsrasterlayer.cpp

@@ -3188,6 +3188,22 @@ bool QgsRasterLayer::readSymbology( const QDomNode& layer_node, QString& errorMe
   }
 
   //resampler
+
+  //max oversampling
+  if ( mRenderer )
+  {
+    QDomElement maxOversamplingElem = mnl.firstChildElement( "MaxOversampling" );
+    if ( !maxOversamplingElem.isNull() )
+    {
+      bool conversion;
+      double maxOversampling = maxOversamplingElem.text().toDouble( &conversion );
+      if ( conversion )
+      {
+        mRenderer->setMaxOversampling( maxOversampling );
+      }
+    }
+  }
+
   QDomElement zoomedInResamplerElem = mnl.firstChildElement( "zoomedInResampler" );
   if ( mRenderer && !zoomedInResamplerElem.isNull() )
   {
@@ -3348,6 +3364,12 @@ bool QgsRasterLayer::writeSymbology( QDomNode & layer_node, QDomDocument & docum
   // resampler
   if ( mRenderer )
   {
+    //Max oversampling
+    QDomElement maxOversamplingElem = document.createElement( "MaxOversampling" );
+    QDomText maxOversamplingText = document.createTextNode( QString::number( mRenderer->maxOversampling() ) );
+    maxOversamplingElem.appendChild( maxOversamplingText );
+    rasterPropertiesElement.appendChild( maxOversamplingElem );
+
     QString zoomedInResamplerString = "nearest";
     const QgsRasterResampler* zoomedInResampler = mRenderer->zoomedInResampler();
     if ( zoomedInResampler )

src/core/raster/qgsrasterrenderer.cpp

@@ -25,7 +25,7 @@
 #include <QPainter>
 
 QgsRasterRenderer::QgsRasterRenderer( QgsRasterDataProvider* provider ): mProvider( provider ), mZoomedInResampler( 0 ), mZoomedOutResampler( 0 ),
-    mOpacity( 1.0 ), mRasterTransparency( 0 ), mAlphaBand( -1 ), mInvertColor( false )
+    mOpacity( 1.0 ), mRasterTransparency( 0 ), mAlphaBand( -1 ), mInvertColor( false ), mMaxOversampling( 2.0 )
 {
 }
 
@@ -76,7 +76,7 @@ void QgsRasterRenderer::startRasterRead( int bandNumber, QgsRasterViewPort* view
       providerExtent = t.transformBoundingBox( providerExtent );
     }
     double pixelRatio = mapToPixel->mapUnitsPerPixel() / ( providerExtent.width() / mProvider->xSize() );
-    oversampling = ( pixelRatio > 4.0 ) ? 4.0 : pixelRatio;
+    oversampling = ( pixelRatio > mMaxOversampling ) ? mMaxOversampling : pixelRatio;
   }
 
   //set oversampling back to 1.0 if no resampler for zoomed in / zoomed out (nearest neighbour)

src/core/raster/qgsrasterrenderer.h

@@ -69,6 +69,9 @@ class QgsRasterRenderer
     void setZoomedOutResampler( QgsRasterResampler* r );
     const QgsRasterResampler* zoomedOutResampler() const { return mZoomedOutResampler; }
 
+    void setMaxOversampling( double os ) { mMaxOversampling = os; }
+    double maxOversampling() const { return mMaxOversampling; }
+
   protected:
     inline double readValue( void *data, QgsRasterDataProvider::DataType type, int index );
 
@@ -110,6 +113,9 @@ class QgsRasterRenderer
 
     bool mInvertColor;
 
+    /**Maximum boundary for oversampling (to avoid too much data traffic). Default: 2.0*/
+    double mMaxOversampling;
+
   private:
     /**Remove part into and release memory*/
     void removePartInfo( int bandNumer );

src/ui/qgsrasterlayerpropertiesbase.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>691</width>
-    <height>598</height>
+    <height>617</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -776,6 +776,16 @@
           <item row="3" column="0">
            <widget class="QComboBox" name="mZoomedOutResamplingComboBox"/>
           </item>
+          <item row="5" column="0">
+           <widget class="QDoubleSpinBox" name="mMaximumOversamplingSpinBox"/>
+          </item>
+          <item row="4" column="0">
+           <widget class="QLabel" name="mMaximumOversamplingLabel">
+            <property name="text">
+             <string>Maximum oversampling</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>
@@ -1834,6 +1844,7 @@ p, li { white-space: pre-wrap; }
 &lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;&lt;/p&gt;
 &lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;&lt;/p&gt;
 &lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;&lt;/p&gt;
+&lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;&quot;&gt;&lt;/p&gt;
 &lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-size:10pt;&quot;&gt;&lt;/p&gt;
 &lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-family:'Sans'; font-size:10pt;&quot;&gt;&lt;/p&gt;
 &lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-size:11pt;&quot;&gt;&lt;/p&gt;