2 files changed, 25 insertions, 0 deletions

diff --git a/src/citra_qt/bootmanager.cpp b/src/citra_qt/bootmanager.cpp
index 20824692d..516e115fd 100644
--- a/src/citra_qt/bootmanager.cpp
+++ b/src/citra_qt/bootmanager.cpp
@@ -2,6 +2,12 @@
 #include <QKeyEvent>
 #include <QApplication>
 
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+// Required for screen DPI information
+#include <QScreen>
+#include <QWindow>
+#endif
+
 #include "common/common.h"
 #include "bootmanager.hxx"
 
@@ -176,6 +182,24 @@ void GRenderWindow::PollEvents() {
     */
 }
 
+// On Qt 5.1+, this correctly gets the size of the framebuffer (pixels).
+//
+// Older versions get the window size (density independent pixels),
+// and hence, do not support DPI scaling ("retina" displays).
+// The result will be a viewport that is smaller than the extent of the window.
+void GRenderWindow::GetFramebufferSize(int* fbWidth, int* fbHeight)
+{
+#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
+    int pixelRatio = child->QPaintDevice::devicePixelRatio();
+    
+    *fbWidth = child->QPaintDevice::width() * pixelRatio;
+    *fbHeight = child->QPaintDevice::height() * pixelRatio;
+#else
+    *fbWidth = child->QPaintDevice::width();
+    *fbHeight = child->QPaintDevice::height();
+#endif
+}
+
 void GRenderWindow::BackupGeometry()
 {
     geometry = ((QGLWidget*)this)->saveGeometry();
diff --git a/src/citra_qt/bootmanager.hxx b/src/citra_qt/bootmanager.hxx
index f8afc403e..ec3e1fe71 100644
--- a/src/citra_qt/bootmanager.hxx
+++ b/src/citra_qt/bootmanager.hxx
@@ -96,6 +96,7 @@ public:
     void MakeCurrent() override;
     void DoneCurrent() override;
     void PollEvents() override;
+    void GetFramebufferSize(int* fbWidth, int* fbHeight) override;
 
     void BackupGeometry();
     void RestoreGeometry();