update

src/qtviewer/main.cpp

@@ -5,7 +5,6 @@
 int main(int argc, char *argv[])
 {
   QApplication app(argc, argv);
-  qreal dpiScale = app.devicePixelRatio();
 
   // Set the icon in the window title-bar on mswindows
   // and dock icon on macos.
@@ -16,6 +15,8 @@ int main(int argc, char *argv[])
   // mswindows - .rc file
   // macos - .icns file (using CMake)
 
+  qreal dpiScale = app.devicePixelRatio();
+
   MainWindow window(dpiScale);
 
   window.show();