use float precision for screen coordinates

this should fix rounding error when the map canvas has an odd pixel size
qgis · Sep 28, 2018 · 33c68d2 · 33c68d2
1 parent 1a61885
commit 33c68d2
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/quickgui/qgsquickmapsettings.cpp b/src/quickgui/qgsquickmapsettings.cpp
@@ -118,7 +118,9 @@ QPointF QgsQuickMapSettings::coordinateToScreen( const QgsPoint &point ) const
 
 QgsPoint QgsQuickMapSettings::screenToCoordinate( const QPointF &point ) const
 {
-  const QgsPointXY pp = mMapSettings.mapToPixel().toMapCoordinates( point.toPoint() );
+  // use floating point precision with mapToCoordinatesF
+  // instead of integer precision of toMapCoordinates( point.toPoint() )
+  const QgsPointXY pp = mMapSettings.mapToPixel().toMapCoordinatesF( point.x(), point.y() );
   return QgsPoint( pp );
 }