raster no data speed up

qgis · Apr 13, 2013 · 5280e21 · 5280e21
1 parent 7d425bf
commit 5280e21
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Showing 4 changed files with 16 additions and 4 deletions.
diff --git a/src/core/raster/qgsrasterblock.cpp b/src/core/raster/qgsrasterblock.cpp
@@ -269,6 +269,11 @@ QGis::DataType QgsRasterBlock::typeWithNoDataValue( QGis::DataType dataType, dou
   return newDataType;
 }
 
+bool QgsRasterBlock::hasNoData() const
+{
+  return mHasNoDataValue || mNoDataBitmap != 0;
+}
+
 bool QgsRasterBlock::isNoDataValue( double value, double noDataValue )
 {
   // More precise would be qIsNaN(value) && qIsNaN(noDataValue(bandNo)), but probably
@@ -302,6 +307,7 @@ QRgb QgsRasterBlock::color( int row, int column ) const
 
 bool QgsRasterBlock::isNoData( size_t index )
 {
+  if ( !mHasNoDataValue && !mNoDataBitmap ) return false;
   if ( index >= ( size_t )mWidth*mHeight )
   {
     QgsDebugMsg( QString( "Index %1 out of range (%2 x %3)" ).arg( index ).arg( mWidth ).arg( mHeight ) );
@@ -662,7 +668,7 @@ bool QgsRasterBlock::convert( QGis::DataType destDataType )
   return true;
 }
 
-void QgsRasterBlock::applyNodataValues( const QgsRasterRangeList & rangeList )
+void QgsRasterBlock::applyNoDataValues( const QgsRasterRangeList & rangeList )
 {
   if ( rangeList.isEmpty() )
   {

diff --git a/src/core/raster/qgsrasterblock.h b/src/core/raster/qgsrasterblock.h
@@ -144,6 +144,12 @@ class CORE_EXPORT QgsRasterBlock
      * @return true if the block has no data value */
     bool hasNoDataValue() const { return mHasNoDataValue; }
 
+    /** Returns true if thee block may contain no data. It does not guarantee
+     * that it really contains any no data. It can be used to speed up processing.
+     * Not the difference between this method and hasNoDataValue().
+     * @return true if the block may contain no data */
+    bool hasNoData() const;
+
     /** Return no data value.
      * @return No data value */
     double noDataValue() const { return mNoDataValue; }
@@ -292,7 +298,7 @@ class CORE_EXPORT QgsRasterBlock
 
     inline static void writeValue( void *data, QGis::DataType type, size_t index, double value );
 
-    void applyNodataValues( const QgsRasterRangeList & rangeList );
+    void applyNoDataValues( const QgsRasterRangeList & rangeList );
 
     /** \brief Get error */
     QgsError error() const { return mError; }

diff --git a/src/core/raster/qgsrasterdataprovider.cpp b/src/core/raster/qgsrasterdataprovider.cpp
@@ -233,7 +233,7 @@ QgsRasterBlock * QgsRasterDataProvider::block( int theBandNo, QgsRectangle  cons
 
   // apply user no data values
   // TODO: there are other readBlock methods where no data are not applied
-  block->applyNodataValues( userNoDataValue( theBandNo ) );
+  block->applyNoDataValues( userNoDataValue( theBandNo ) );
   return block;
 }
 

diff --git a/src/providers/gdal/qgsgdalprovider.cpp b/src/providers/gdal/qgsgdalprovider.cpp
@@ -386,7 +386,7 @@ QgsRasterBlock* QgsGdalProvider::block( int theBandNo, const QgsRectangle &theEx
     block->setIsNoDataExcept( subRect );
   }
   readBlock( theBandNo, theExtent, theWidth, theHeight, block->data() );
-  block->applyNodataValues( userNoDataValue( theBandNo ) );
+  block->applyNoDataValues( userNoDataValue( theBandNo ) );
   return block;
 }