From b74fd6d4a2f2d61cf38c31117645cae8e5f9e0f1 Mon Sep 17 00:00:00 2001
From: Stan <stan@wildfiregames.com>
Date: Thu, 30 Dec 2021 13:57:40 +0000
Subject: [PATCH] Use the high performance GPU on Windows by default.

Reviewed by: @vladislavbelov
Accepted by: @asterix
Differential Revision: https://code.wildfiregames.com/D4401
This was SVN commit r26140.
---
 source/main.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/source/main.cpp b/source/main.cpp
index 408f19fe7b..ed67c69b67 100644
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -100,6 +100,24 @@ that of Atlas depending on commandline parameters.
 #define getpid _getpid // Use the non-deprecated function name
 #endif
 
+#if OS_WIN
+// We don't want to include Windows.h as it might mess up the rest
+// of the file so we just define DWORD as done in Windef.h.
+#ifndef DWORD
+typedef unsigned long DWORD;
+#endif // !DWORD
+// Request the high performance GPU on Windows by default if no system override is specified.
+// See:
+// - https://github.com/supertuxkart/stk-code/pull/4693/commits/0a99c667ef513b2ce0f5755729a6e05df8aac48a
+// - https://docs.nvidia.com/gameworks/content/technologies/desktop/optimus.htm 
+// - https://gpuopen.com/learn/amdpowerxpressrequesthighperformance/ 
+extern "C"
+{
+	__declspec(dllexport) DWORD NvOptimusEnablement = 0x00000001;
+	__declspec(dllexport) DWORD AmdPowerXpressRequestHighPerformance = 0x00000001;
+}
+#endif
+
 #include <chrono>
 
 extern CStrW g_UniqueLogPostfix;