Fix picking of transparent pixels

qgis · Jul 1, 2012 · 3deef8b · 3deef8b
1 parent fa292eb
commit 3deef8b
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Showing 7 changed files with 109 additions and 24 deletions.
diff --git a/src/app/qgsrasterlayerproperties.cpp b/src/app/qgsrasterlayerproperties.cpp
@@ -1315,44 +1315,42 @@ void QgsRasterLayerProperties::on_pbnRemoveSelectedRow_clicked()
 
 void QgsRasterLayerProperties::pixelSelected( const QgsPoint& canvasPoint )
 {
-#if 0 //needs to be fixed
-  //PixelSelectorTool has registered a mouse click on the canvas, so bring the dialog back to the front
+  QgsRasterRenderer* renderer = mRendererWidget->renderer();
+  if ( !renderer )
+  {
+    return;
+  }
+
   raise();
   setModal( true );
   activateWindow();
 
   //Get the pixel values and add a new entry to the transparency table
   if ( mMapCanvas && mPixelSelectorTool )
   {
-    QMap< QString, QString > myPixelMap;
+    QMap< int, QString > myPixelMap;
     mMapCanvas->unsetMapTool( mPixelSelectorTool );
     mRasterLayer->identify( mMapCanvas->mapRenderer()->mapToLayerCoordinates( mRasterLayer, canvasPoint ), myPixelMap );
-    if ( tableTransparency->columnCount() == 2 )
-    {
-      QString myValue = myPixelMap[ mRasterLayer->grayBandName()];
-      if ( myValue != tr( "out of extent" ) )
-      {
-        tableTransparency->insertRow( tableTransparency->rowCount() );
-        tableTransparency->setItem( tableTransparency->rowCount() - 1, tableTransparency->columnCount() - 1, new QTableWidgetItem( "100.0" ) );
-        tableTransparency->setItem( tableTransparency->rowCount() - 1, 0, new QTableWidgetItem( myValue ) );
-      }
-    }
-    else
+
+    QList<int> bands = renderer->usesBands();
+    tableTransparency->insertRow( tableTransparency->rowCount() );
+    tableTransparency->setItem( tableTransparency->rowCount() - 1, tableTransparency->columnCount() - 1, new QTableWidgetItem( "100.0" ) );
+
+    for ( int i = 0; i < bands.size(); ++i )
     {
-      QString myValue = myPixelMap[ mRasterLayer->redBandName()];
-      if ( myValue != tr( "out of extent" ) )
+      QMap< int, QString >::const_iterator pixelResult = myPixelMap.find( bands.at( i ) );
+      if ( pixelResult != myPixelMap.constEnd() )
       {
-        tableTransparency->insertRow( tableTransparency->rowCount() );
-        tableTransparency->setItem( tableTransparency->rowCount() - 1, tableTransparency->columnCount() - 1, new QTableWidgetItem( "100.0" ) );
-        tableTransparency->setItem( tableTransparency->rowCount() - 1, 0, new QTableWidgetItem( myValue ) );
-        tableTransparency->setItem( tableTransparency->rowCount() - 1, 1, new QTableWidgetItem( myPixelMap[ mRasterLayer->greenBandName()] ) );
-        tableTransparency->setItem( tableTransparency->rowCount() - 1, 2, new QTableWidgetItem( myPixelMap[ mRasterLayer->blueBandName()] ) );
+        QString value = pixelResult.value();
+        if ( value != tr( "out of extent" ) )
+        {
+          tableTransparency->setItem( tableTransparency->rowCount() - 1, i, new QTableWidgetItem( value ) );
+        }
       }
     }
   }
-#else
-  Q_UNUSED( canvasPoint );
-#endif //0
+
+  delete renderer;
 }
 
 void QgsRasterLayerProperties::sliderTransparency_valueChanged( int theValue )

diff --git a/src/core/qgsrasterdataprovider.cpp b/src/core/qgsrasterdataprovider.cpp
@@ -184,6 +184,13 @@ bool QgsRasterDataProvider::identify( const QgsPoint& thePoint, QMap<QString, QS
   return false;
 }
 
+bool QgsRasterDataProvider::identify( const QgsPoint & point, QMap<int, QString>& results )
+{
+  Q_UNUSED( point );
+  results.clear();
+  return false;
+}
+
 QString QgsRasterDataProvider::lastErrorFormat()
 {
   return "text/plain";

diff --git a/src/core/qgsrasterdataprovider.h b/src/core/qgsrasterdataprovider.h
@@ -390,6 +390,8 @@ class CORE_EXPORT QgsRasterDataProvider : public QgsDataProvider
     /** \brief Identify raster value(s) found on the point position */
     virtual bool identify( const QgsPoint & point, QMap<QString, QString>& results );
 
+    virtual bool identify( const QgsPoint & point, QMap<int, QString>& results );
+
     /**
      * \brief Identify details from a server (e.g. WMS) from the last screen update
      *

diff --git a/src/core/raster/qgsrasterlayer.cpp b/src/core/raster/qgsrasterlayer.cpp
@@ -914,6 +914,18 @@ bool QgsRasterLayer::identify( const QgsPoint& thePoint, QMap<QString, QString>&
   return ( mDataProvider->identify( thePoint, theResults ) );
 }
 
+bool QgsRasterLayer::identify( const QgsPoint & point, QMap<int, QString>& results )
+{
+  if ( !mDataProvider )
+  {
+    return false;
+  }
+
+  results.clear();
+  return mDataProvider->identify( point, results );
+}
+
+
 /**
  * @note  The arbitraryness of the returned document is enforced by WMS standards up to at least v1.3.0
  *

diff --git a/src/core/raster/qgsrasterlayer.h b/src/core/raster/qgsrasterlayer.h
@@ -457,6 +457,9 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     /** \brief Identify raster value(s) found on the point position */
     bool identify( const QgsPoint & point, QMap<QString, QString>& results );
 
+    /** \brief Identify raster value(s) found on the point position */
+    bool identify( const QgsPoint & point, QMap<int, QString>& results );
+
     /** \brief Identify arbitrary details from the WMS server found on the point position */
     QString identifyAsText( const QgsPoint & point );
 

diff --git a/src/providers/gdal/qgsgdalprovider.cpp b/src/providers/gdal/qgsgdalprovider.cpp
@@ -1117,6 +1117,67 @@ int QgsGdalProvider::yBlockSize() const
 int QgsGdalProvider::xSize() const { return mWidth; }
 int QgsGdalProvider::ySize() const { return mHeight; }
 
+bool QgsGdalProvider::identify( const QgsPoint & point, QMap<int, QString>& results )
+{
+  // QgsDebugMsg( "Entered" );
+  if ( !mExtent.contains( point ) )
+  {
+    // Outside the raster
+    for ( int i = 1; i <= GDALGetRasterCount( mGdalDataset ); i++ )
+    {
+      results[ i ] = tr( "out of extent" );
+    }
+  }
+  else
+  {
+    double x = point.x();
+    double y = point.y();
+
+    // Calculate the row / column where the point falls
+    double xres = ( mExtent.xMaximum() - mExtent.xMinimum() ) / mWidth;
+    double yres = ( mExtent.yMaximum() - mExtent.yMinimum() ) / mHeight;
+
+    // Offset, not the cell index -> flor
+    int col = ( int ) floor(( x - mExtent.xMinimum() ) / xres );
+    int row = ( int ) floor(( mExtent.yMaximum() - y ) / yres );
+
+    // QgsDebugMsg( "row = " + QString::number( row ) + " col = " + QString::number( col ) );
+
+    for ( int i = 1; i <= GDALGetRasterCount( mGdalDataset ); i++ )
+    {
+      GDALRasterBandH gdalBand = GDALGetRasterBand( mGdalDataset, i );
+      double value;
+
+      CPLErr err = GDALRasterIO( gdalBand, GF_Read, col, row, 1, 1,
+                                 &value, 1, 1, GDT_Float64, 0, 0 );
+
+      if ( err != CPLE_None )
+      {
+        QgsLogger::warning( "RasterIO error: " + QString::fromUtf8( CPLGetLastErrorMsg() ) );
+      }
+
+      //double value = readValue( data, type, 0 );
+      // QgsDebugMsg( QString( "value=%1" ).arg( value ) );
+      QString v;
+
+      if ( mValidNoDataValue && ( fabs( value - mNoDataValue[i-1] ) <= TINY_VALUE || value != value ) )
+      {
+        v = tr( "null (no data)" );
+      }
+      else
+      {
+        v.setNum( value );
+      }
+
+      results[ i ] = v;
+
+      //CPLFree( data );
+    }
+  }
+
+  return true;
+}
+
 bool QgsGdalProvider::identify( const QgsPoint& thePoint, QMap<QString, QString>& theResults )
 {
   // QgsDebugMsg( "Entered" );

diff --git a/src/providers/gdal/qgsgdalprovider.h b/src/providers/gdal/qgsgdalprovider.h
@@ -135,6 +135,8 @@ class QgsGdalProvider : public QgsRasterDataProvider
     /** \brief Identify raster value(s) found on the point position */
     bool identify( const QgsPoint & point, QMap<QString, QString>& results );
 
+    bool identify( const QgsPoint & point, QMap<int, QString>& results );
+
     /**
      * \brief Identify details from a GDAL layer from the last screen update
      *