Added two helper function to correctly translate QT mouse events into coords for our trackball.

You must use QT2VCG_X QT2VCG_Y instead of passing the event coords because on newer machines (mac but also win) with very high res monitor, qt events are no more in physical coords.

wrap/qt/trackball.h

@@ -30,8 +30,35 @@ $Log: trackball.h,v $
 #ifndef QT_TRACKBALL_H
 #define QT_TRACKBALL_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.
+
+float QT2VCG_X( QWidget *qw, QMouseEvent *e)
+{
+#if QT_VERSION >= 0x050000
+  return e->x ()*qw->devicePixelRatio() ;
+#else
+  Q_UNUSED(qw);
+  return e->x ();
+#endif
+}
+
+/// 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.
+
+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
+}
+
 /// Takes a QT MouseButton, some QT KeyboardModifiers and returns the equivalent Trackball::Button
-static vcg::Trackball::Button QT2VCG (Qt::MouseButton qtbt, Qt::KeyboardModifiers modifiers)
+ vcg::Trackball::Button QT2VCG (Qt::MouseButton qtbt, Qt::KeyboardModifiers modifiers)
 {
   int vcgbt = vcg::Trackball::BUTTON_NONE;