From 10419b8947018d21eb6ddbf97109357dc225e1da Mon Sep 17 00:00:00 2001
From: falkTX <falktx@falktx.com>
Date: Sat, 14 Aug 2021 13:21:41 +0100
Subject: [PATCH] Fix OpenGL viewport size for fullviewport-drawing and
 auto-scaling

Signed-off-by: falkTX <falktx@falktx.com>
---
 dgl/src/OpenGL.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/dgl/src/OpenGL.cpp b/dgl/src/OpenGL.cpp
index df91b34b..8cc6d889 100644
--- a/dgl/src/OpenGL.cpp
+++ b/dgl/src/OpenGL.cpp
@@ -598,7 +598,10 @@ void SubWidget::PrivateData::display(const uint width, const uint height, const
     else if (needsFullViewportForDrawing || (absolutePos.isZero() && self->getSize() == Size<uint>(width, height)))
     {
         // full viewport size
-        glViewport(0, 0, static_cast<int>(width), static_cast<int>(height));
+        glViewport(0,
+                   -static_cast<int>(height * autoScaleFactor - height + 0.5),
+                   static_cast<int>(width * autoScaleFactor + 0.5),
+                   static_cast<int>(height * autoScaleFactor + 0.5));
     }
     else
     {