From 12ab54648cb04d79c446a089f1652c05da1c6264 Mon Sep 17 00:00:00 2001
From: Pavel Rojtberg <rojtberg@gmail.com>
Date: Sat, 12 Feb 2022 14:56:42 +0100
Subject: [PATCH] highui: qt - enable hidpi by default

can be overriden by environment:
QT_AUTO_SCREEN_SCALE_FACTOR=0
---
 modules/highgui/src/window_QT.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/modules/highgui/src/window_QT.cpp b/modules/highgui/src/window_QT.cpp
index f6ba44b425..d8f2271faa 100644
--- a/modules/highgui/src/window_QT.cpp
+++ b/modules/highgui/src/window_QT.cpp
@@ -529,6 +529,9 @@ static int icvInitSystem(int* c, char** v)
     //"For any GUI application using Qt, there is precisely one QApplication object"
     if (!QApplication::instance())
     {
+#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
+        QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling, true);
+#endif
         new QApplication(*c, v);
         setlocale(LC_NUMERIC,"C");