diff --git a/wrap/qt/device_to_logical.h b/wrap/qt/device_to_logical.h
new file mode 100644
index 00000000..95d13980
--- /dev/null
+++ b/wrap/qt/device_to_logical.h
@@ -0,0 +1,37 @@
+#ifndef DEVICE_TO_LOGICAL_H
+#define DEVICE_TO_LOGICAL_H
+#include <QPainter>
+template < class ValueType>
+inline ValueType QTLogicalToDevice( QWidget *qw, const ValueType &value)
+{
+#if QT_VERSION >= 0x050000
+  return value*qw->devicePixelRatio() ;
+#else
+  Q_UNUSED(qw);
+  return value;
+#endif
+}
+
+template < class ValueType>
+inline ValueType QTLogicalToDevice( QPainter *qp, const ValueType &value)
+{
+#if QT_VERSION >= 0x050000
+  return value*qp->device()->devicePixelRatio() ;
+#else
+  Q_UNUSED(qp);
+  return value;
+#endif
+}
+
+template < class ValueType>
+inline ValueType QTDeviceToLogical( QPainter *qp, const ValueType &value)
+{
+#if QT_VERSION >= 0x050000
+  return value/qp->device()->devicePixelRatio() ;
+#else
+  Q_UNUSED(qp);
+  return value;
+#endif
+}
+
+#endif // DEVICE_TO_LOGICAL_H
diff --git a/wrap/qt/gl_label.h b/wrap/qt/gl_label.h
index 86c06764..10f39b89 100755
--- a/wrap/qt/gl_label.h
+++ b/wrap/qt/gl_label.h
@@ -25,6 +25,7 @@
 
 #include <QMessageBox>
 #include <wrap/qt/col_qt_convert.h>
+#include <wrap/qt/device_to_logical.h>
 #include <wrap/qt/checkGLError.h>
 #include <QPainter>
 namespace vcg
@@ -33,7 +34,8 @@ namespace vcg
  */
   class glLabel
   {
-	public:
+
+    public:
     class Mode
     {
     public:
@@ -64,7 +66,7 @@ namespace vcg
   private:
     static void enter2D(QPainter *painter)
     {
-      glPushAttrib(GL_ENABLE_BIT);
+      glPushAttrib(GL_ENABLE_BIT|GL_VIEWPORT_BIT);
       glDisable(GL_DEPTH_TEST);
       glMatrixMode(GL_PROJECTION);
       glPushMatrix();
@@ -84,7 +86,6 @@ namespace vcg
       glMatrixMode(GL_MODELVIEW);
       glPopMatrix();
       glPopAttrib();
-      //checkGLError::qDebug("glLabel");
     }
 
   public:
@@ -134,6 +135,7 @@ namespace vcg
         base.setX(-textBox.width() -qfm.maxWidth());
       painter->drawText(base,text);
       glLabel::exit2D(painter);
+      glViewport(view[0],view[1],view[2],view[3]);
     }
 
     static void render(QPainter *painter, const vcg::Point3f &p, const QString &text)
@@ -162,7 +164,8 @@ namespace vcg
       painter->setRenderHint(QPainter::TextAntialiasing);
       painter->setPen(vcg::ColorConverter::ToQColor(m.color));
       painter->setFont(m.qFont);
-      painter->translate(QPointF(winx,view[3]-winy));
+      painter->translate(QPointF(QTDeviceToLogical(painter,winx),
+                                 QTDeviceToLogical(painter,view[3]-winy)));
       painter->rotate(m.angle);
       QPoint base(0,qfm.ascent()/2);
       if(m.rightAlign)
diff --git a/wrap/qt/trackball.h b/wrap/qt/trackball.h
index 089d225b..866e6988 100644
--- a/wrap/qt/trackball.h
+++ b/wrap/qt/trackball.h
@@ -23,19 +23,14 @@
 
 #ifndef QT_TRACKBALL_H
 #define QT_TRACKBALL_H
+#include <wrap/qt/device_to_logical.h>
 
 /// Transforms the event coordintates (that are device independent)
 /// into the expected framebuffer coordinates (e.g.in opengl pixels)
 /// This is necessary because trackball works in the viewport coord systems.
-
 inline float QT2VCG_X( QWidget *qw, QMouseEvent *e)
 {
-#if QT_VERSION >= 0x050000
-  return e->x ()*qw->devicePixelRatio() ;
-#else
-  Q_UNUSED(qw);
-  return e->x ();
-#endif
+  return QTLogicalToDevice(qw,e->x());
 }
 
 /// Transforms the event coordintates (that are device independent)
@@ -44,11 +39,7 @@ inline float QT2VCG_X( QWidget *qw, QMouseEvent *e)
 
 inline float QT2VCG_Y( QWidget *qw, QMouseEvent *e)
 {
-#if QT_VERSION >= 0x050000
-  return (qw->height () - e->y ())*qw->devicePixelRatio() ;
-#else
-  return qw->height () - e->y ();
-#endif
+  return QTLogicalToDevice(qw,qw->height () - e->y ());
 }
 
 /// Takes a QT MouseButton, some QT KeyboardModifiers and returns the equivalent Trackball::Button