From 3a1243b05eece82e5b94628001480548cb07e5b1 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Wed, 4 Mar 2020 11:41:55 +0100
Subject: [PATCH] [util] Don't set display mode if the desired mode is already
 set

See #1489.

Co-authored-by: zvova7890 <zvova7890@gmail.com>
---
 src/util/util_monitor.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/util/util_monitor.cpp b/src/util/util_monitor.cpp
index 287677604..1b84714ff 100644
--- a/src/util/util_monitor.cpp
+++ b/src/util/util_monitor.cpp
@@ -25,6 +25,21 @@ namespace dxvk {
       pMode->dmPelsWidth, "x", pMode->dmPelsHeight, "@",
       pMode->dmDisplayFrequency));
 
+    DEVMODEW curMode = { };
+    curMode.dmSize = sizeof(curMode);
+
+    if (GetMonitorDisplayMode(hMonitor, ENUM_CURRENT_SETTINGS, &curMode)) {
+      bool eq = curMode.dmPelsWidth  == pMode->dmPelsWidth
+             && curMode.dmPelsHeight == pMode->dmPelsHeight
+             && curMode.dmBitsPerPel == pMode->dmBitsPerPel;
+
+      if (pMode->dmFields & DM_DISPLAYFREQUENCY)
+        eq &= curMode.dmDisplayFrequency == pMode->dmDisplayFrequency;
+
+      if (eq)
+        return true;
+    }
+
     LONG status = ::ChangeDisplaySettingsExW(monInfo.szDevice,
       pMode, nullptr, CDS_FULLSCREEN, nullptr);