fix/reintroduce wms layer transparency

git-svn-id: http://svn.osgeo.org/qgis/trunk@15473 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: jef

src/core/raster/qgsrasterlayer.cpp

@@ -3622,12 +3622,43 @@ void QgsRasterLayer::drawSingleBandColorData( QPainter * theQPainter, QgsRasterV
   QRgb* imageScanLine = 0;
   void* rasterScanLine = 0;
 
+  QRgb myDefaultColor = qRgba( 255, 255, 255, 0 );
+
   while ( imageBuffer.nextScanLine( &imageScanLine, &rasterScanLine ) )
   {
-    int size = theRasterViewPort->drawableAreaXDim * 4;
-    memcpy( imageScanLine, rasterScanLine, size );
-  }
+    if ( mTransparencyLevel == 0 )
+    {
+      int size = theRasterViewPort->drawableAreaXDim * 4;
+      memcpy( imageScanLine, rasterScanLine, size );
+    }
+    else
+    {
+      uint *p = ( uint* ) rasterScanLine;
+      for ( int i = 0; i < theRasterViewPort->drawableAreaXDim; ++i )
+      {
+        uint v = *p++;
+        int myRedValue   = ( v & 0xff0000 ) >> 16;
+        int myGreenValue = ( v & 0xff00 ) >> 8;
+        int myBlueValue  = ( v & 0xff );
 
+        int myAlphaValue = mRasterTransparency.alphaValue( myRedValue, myGreenValue, myBlueValue, mTransparencyLevel );
+        if ( 0 == myAlphaValue )
+        {
+          imageScanLine[ i ] = myDefaultColor;
+          continue;
+        }
+
+        if ( mInvertColor )
+        {
+          myRedValue = 255 - myRedValue;
+          myGreenValue = 255 - myGreenValue;
+          myBlueValue = 255 - myBlueValue;
+        }
+
+        imageScanLine[ i ] = qRgba( myRedValue, myGreenValue, myBlueValue, myAlphaValue );
+      }
+    }
+  }
 }
 
 void QgsRasterLayer::drawMultiBandColor( QPainter * theQPainter, QgsRasterViewPort * theRasterViewPort,