avoid creating a histogram without range (fixes #10832)

qgis · Oct 15, 2014 · 962a7d9 · 962a7d9
1 parent c90d810
commit 962a7d9
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Showing 5 changed files with 54 additions and 42 deletions.
diff --git a/src/app/qgsrasterlayerproperties.cpp b/src/app/qgsrasterlayerproperties.cpp
@@ -512,7 +512,7 @@ void QgsRasterLayerProperties::setRendererWidget( const QString& rendererName )
       QgsDebugMsg( "renderer has widgetCreateFunction" );
       // Current canvas extent (used to calc min/max) in layer CRS
       QgsRectangle myExtent = mMapCanvas->mapSettings().outputExtentToLayerExtent( mRasterLayer, mMapCanvas->extent() );
-      mRendererWidget = ( *rendererEntry.widgetCreateFunction )( mRasterLayer, myExtent );
+      mRendererWidget = rendererEntry.widgetCreateFunction( mRasterLayer, myExtent );
       mRendererStackedWidget->addWidget( mRendererWidget );
       if ( oldWidget )
       {

diff --git a/src/core/raster/qgsrasterbandstats.h b/src/core/raster/qgsrasterbandstats.h
@@ -50,7 +50,7 @@ class CORE_EXPORT QgsRasterBandStats
     {
       statsGathered = None;
       minimumValue = std::numeric_limits<double>::max();
-      maximumValue = std::numeric_limits<double>::min();
+      maximumValue = -std::numeric_limits<double>::max();
       range = 0.0;
       mean = 0.0;
       sumOfSquares = 0.0;

diff --git a/src/core/raster/qgsrasterinterface.cpp b/src/core/raster/qgsrasterinterface.cpp
@@ -273,7 +273,7 @@ void QgsRasterInterface::initHistogram( QgsRasterHistogram &theHistogram,
       // We need statistics -> avoid histogramDefaults in hasHistogram if possible
       // TODO: use approximated statistics if aproximated histogram is requested
       // (theSampleSize > 0)
-      QgsRasterBandStats stats =  bandStatistics( theBandNo, QgsRasterBandStats::Min, theExtent, theSampleSize );
+      QgsRasterBandStats stats = bandStatistics( theBandNo, QgsRasterBandStats::Min, theExtent, theSampleSize );
       theHistogram.minimum = stats.minimumValue;
     }
   }
@@ -285,7 +285,7 @@ void QgsRasterInterface::initHistogram( QgsRasterHistogram &theHistogram,
     }
     else
     {
-      QgsRasterBandStats stats =  bandStatistics( theBandNo, QgsRasterBandStats::Max, theExtent, theSampleSize );
+      QgsRasterBandStats stats = bandStatistics( theBandNo, QgsRasterBandStats::Max, theExtent, theSampleSize );
       theHistogram.maximum = stats.maximumValue;
     }
   }
@@ -518,7 +518,7 @@ void QgsRasterInterface::cumulativeCut( int theBandNo,
   int mySrcDataType = srcDataType( theBandNo );
 
   //get band stats to specify real histogram min/max (fix #9793 Byte bands)
-  QgsRasterBandStats stats =  bandStatistics( theBandNo, QgsRasterBandStats::Min, theExtent, theSampleSize );
+  QgsRasterBandStats stats = bandStatistics( theBandNo, QgsRasterBandStats::Min, theExtent, theSampleSize );
   // for byte bands make sure bin count == actual range
   int myBinCount = ( mySrcDataType == QGis::Byte ) ? int( ceil( stats.maximumValue - stats.minimumValue + 1 ) ) : 0;
   QgsRasterHistogram myHistogram = histogram( theBandNo, myBinCount, stats.minimumValue, stats.maximumValue, theExtent, theSampleSize );

diff --git a/src/gui/raster/qgsrasterhistogramwidget.cpp b/src/gui/raster/qgsrasterhistogramwidget.cpp
@@ -606,53 +606,65 @@ void QgsRasterHistogramWidget::refreshHistogram()
     QgsDebugMsg( QString( "computed histo min = %1 max = %2" ).arg( mHistoMin ).arg( mHistoMax ) );
     myFirstIteration = false;
   }
-  // for x axis use band pixel values rather than gdal hist. bin values
-  // subtract -0.5 to prevent rounding errors
-  // see http://www.gdal.org/classGDALRasterBand.html#3f8889607d3b2294f7e0f11181c201c8
-  // fix x range for non-Byte data
-  mpPlot->setAxisScale( QwtPlot::xBottom,
-                        mHistoMin - myBinXStep / 2,
-                        mHistoMax + myBinXStep / 2 );
 
-  mpPlot->replot();
+  if ( mHistoMin < mHistoMax )
+  {
+    // for x axis use band pixel values rather than gdal hist. bin values
+    // subtract -0.5 to prevent rounding errors
+    // see http://www.gdal.org/classGDALRasterBand.html#3f8889607d3b2294f7e0f11181c201c8
+    // fix x range for non-Byte data
+    mpPlot->setAxisScale( QwtPlot::xBottom,
+                          mHistoMin - myBinXStep / 2,
+                          mHistoMax + myBinXStep / 2 );
+    mpPlot->setEnabled( true );
+    mpPlot->replot();
 
-  // histo plot markers
-  // memory leak?
-  mHistoMarkerMin = new QwtPlotMarker();
-  mHistoMarkerMin->attach( mpPlot );
-  mHistoMarkerMax = new QwtPlotMarker();
-  mHistoMarkerMax->attach( mpPlot );
-  updateHistoMarkers();
+    // histo plot markers
+    // memory leak?
+    mHistoMarkerMin = new QwtPlotMarker();
+    mHistoMarkerMin->attach( mpPlot );
+    mHistoMarkerMax = new QwtPlotMarker();
+    mHistoMarkerMax->attach( mpPlot );
+    updateHistoMarkers();
 
-  // histo picker
-  if ( ! mHistoPicker )
-  {
-    mHistoPicker = new QwtPlotPicker( mpPlot->canvas() );
-    // mHistoPicker->setTrackerMode( QwtPicker::ActiveOnly );
-    mHistoPicker->setTrackerMode( QwtPicker::AlwaysOff );
-    mHistoPicker->setRubberBand( QwtPicker::VLineRubberBand );
-    mHistoPicker->setEnabled( false );
+    // histo picker
+    if ( !mHistoPicker )
+    {
+      mHistoPicker = new QwtPlotPicker( mpPlot->canvas() );
+      // mHistoPicker->setTrackerMode( QwtPicker::ActiveOnly );
+      mHistoPicker->setTrackerMode( QwtPicker::AlwaysOff );
+      mHistoPicker->setRubberBand( QwtPicker::VLineRubberBand );
 #if defined(QWT_VERSION) && QWT_VERSION>=0x060000
-    mHistoPicker->setStateMachine( new QwtPickerDragPointMachine );
-    connect( mHistoPicker, SIGNAL( selected( const QPointF & ) ), this, SLOT( histoPickerSelected( const QPointF & ) ) );
+      mHistoPicker->setStateMachine( new QwtPickerDragPointMachine );
+      connect( mHistoPicker, SIGNAL( selected( const QPointF & ) ), this, SLOT( histoPickerSelected( const QPointF & ) ) );
 #else
-    mHistoPicker->setSelectionFlags( QwtPicker::PointSelection | QwtPicker::DragSelection );
-    connect( mHistoPicker, SIGNAL( selected( const QwtDoublePoint & ) ), this, SLOT( histoPickerSelectedQwt5( const QwtDoublePoint & ) ) );
+      mHistoPicker->setSelectionFlags( QwtPicker::PointSelection | QwtPicker::DragSelection );
+      connect( mHistoPicker, SIGNAL( selected( const QwtDoublePoint & ) ), this, SLOT( histoPickerSelectedQwt5( const QwtDoublePoint & ) ) );
 #endif
-  }
+    }
+    mHistoPicker->setEnabled( false );
 
-  // plot zoomer
-  if ( ! mHistoZoomer )
-  {
-    mHistoZoomer = new QwtPlotZoomer( mpPlot->canvas() );
+    // plot zoomer
+    if ( !mHistoZoomer )
+    {
+      mHistoZoomer = new QwtPlotZoomer( mpPlot->canvas() );
 #if defined(QWT_VERSION) && QWT_VERSION>=0x060000
-    mHistoZoomer->setStateMachine( new QwtPickerDragRectMachine );
+      mHistoZoomer->setStateMachine( new QwtPickerDragRectMachine );
 #else
-    mHistoZoomer->setSelectionFlags( QwtPicker::RectSelection | QwtPicker::DragSelection );
+      mHistoZoomer->setSelectionFlags( QwtPicker::RectSelection | QwtPicker::DragSelection );
 #endif
-    mHistoZoomer->setTrackerMode( QwtPicker::AlwaysOff );
+      mHistoZoomer->setTrackerMode( QwtPicker::AlwaysOff );
+    }
     mHistoZoomer->setEnabled( true );
   }
+  else
+  {
+    mpPlot->setDisabled( true );
+    if ( mHistoPicker )
+      mHistoPicker->setEnabled( false );
+    if ( mHistoZoomer )
+      mHistoZoomer->setEnabled( false );
+  }
 
   disconnect( mRasterLayer, SIGNAL( progressUpdate( int ) ), mHistogramProgress, SLOT( setValue( int ) ) );
   stackedWidget2->setCurrentIndex( 0 );

diff --git a/src/providers/gdal/qgsgdalprovider.cpp b/src/providers/gdal/qgsgdalprovider.cpp
@@ -1397,7 +1397,7 @@ QgsRasterHistogram QgsGdalProvider::histogram( int theBandNo,
   myMinVal -= dfHalfBucket;
   myMaxVal += dfHalfBucket;
 
-  /*
+#if 0
   const char* pszPixelType = GDALGetMetadataItem( myGdalBand, "PIXELTYPE", "IMAGE_STRUCTURE" );
   int bSignedByte = ( pszPixelType != NULL && EQUAL( pszPixelType, "SIGNEDBYTE" ) );
 
@@ -1420,7 +1420,7 @@ QgsRasterHistogram QgsGdalProvider::histogram( int theBandNo,
     myMinVal -= dfHalfBucket;
     myMaxVal += dfHalfBucket;
   }
-  */
+#endif
 
   int *myHistogramArray = new int[myHistogram.binCount];
   CPLErr myError = GDALGetRasterHistogram( myGdalBand, myMinVal, myMaxVal,