Fix #9698 (magnified SVG symbols with data-defined rotation)

qgis · Mar 4, 2014 · 86ea4bf · 86ea4bf
1 parent 9774abd
commit 86ea4bf
Showing 1 changed file with 16 additions and 0 deletions.
diff --git a/src/core/symbology-ng/qgsmarkersymbollayerv2.cpp b/src/core/symbology-ng/qgsmarkersymbollayerv2.cpp
@@ -32,6 +32,19 @@
 
 #include <cmath>
 
+Q_GUI_EXPORT extern int qt_defaultDpiX();
+Q_GUI_EXPORT extern int qt_defaultDpiY();
+
+static void _fixQPictureDPI( QPainter* p )
+{
+  // QPicture makes an assumption that we drawing to it with system DPI.
+  // Then when being drawn, it scales the painter. The following call
+  // negates the effect. There is no way of setting QPicture's DPI.
+  // See QTBUG-20361
+  p->scale(( double )qt_defaultDpiX() / p->device()->logicalDpiX(),
+           ( double )qt_defaultDpiY() / p->device()->logicalDpiY() );
+}
+
 //////
 
 QgsSimpleMarkerSymbolLayerV2::QgsSimpleMarkerSymbolLayerV2( QString name, QColor color, QColor borderColor, double size, double angle, QgsSymbolV2::ScaleMethod scaleMethod )
@@ -1189,7 +1202,10 @@ void QgsSvgMarkerSymbolLayerV2::renderPoint( const QPointF& point, QgsSymbolV2Re
 
     if ( pct.width() > 1 )
     {
+      p->save();
+      _fixQPictureDPI( p );
       p->drawPicture( 0, 0, pct );
+      p->restore();
       hwRatio = ( double )pct.height() / ( double )pct.width();
     }
   }