From 25a6b128eb1c3d211b6af4b72d819479ee8d5b4e Mon Sep 17 00:00:00 2001
From: momo5502 <mauriceheumann@gmail.com>
Date: Sat, 18 Feb 2023 08:46:11 +0100
Subject: [PATCH] Trigger high performance GPU

This fixes #167
---
 src/client/main.cpp        | 29 ++++++++++++++--
 src/client/std_include.cpp |  6 ++++
 src/client/std_include.hpp |  2 ++
 src/common/utils/nt.cpp    | 29 ++++++++++++++++
 src/common/utils/nt.hpp    | 71 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 135 insertions(+), 2 deletions(-)

diff --git a/src/client/main.cpp b/src/client/main.cpp
index 1dfdb9ae..c6559941 100644
--- a/src/client/main.cpp
+++ b/src/client/main.cpp
@@ -212,6 +212,26 @@ namespace
 		}
 	}
 
+	void trigger_high_performance_gpu_switch()
+	{
+		// Make sure to link D3D11, as this might trigger high performance GPU
+		static volatile auto _ = &D3D11CreateDevice;
+
+		const auto key = utils::nt::open_or_create_registry_key(
+			HKEY_CURRENT_USER, R"(Software\Microsoft\DirectX\UserGpuPreferences)");
+		if (!key)
+		{
+			return;
+		}
+
+		const auto self = utils::nt::library::get_by_address(&trigger_high_performance_gpu_switch);
+
+		const std::wstring data = L"GpuPreference=2;";
+		RegSetValueExW(key, self.get_path().make_preferred().wstring().data(), 0, REG_SZ,
+		               reinterpret_cast<const BYTE*>(data.data()),
+		               static_cast<DWORD>((data.size() + 1u) * 2));
+	}
+
 	int main()
 	{
 		if (handle_process_runner())
@@ -246,9 +266,14 @@ namespace
 
 				const auto is_server = utils::flags::has_flag("dedicated") || (!has_client && has_server);
 
-				if (!is_server && !launcher::run())
+				if (!is_server)
 				{
-					return 0;
+					trigger_high_performance_gpu_switch();
+
+					if (!launcher::run())
+					{
+						return 0;
+					}
 				}
 
 				if (!component_loader::activate(is_server))
diff --git a/src/client/std_include.cpp b/src/client/std_include.cpp
index a28d1f38..a3f3a99f 100644
--- a/src/client/std_include.cpp
+++ b/src/client/std_include.cpp
@@ -24,3 +24,9 @@ extern "C"
 		return -1;
 	}
 }
+
+extern "C"
+{
+	__declspec(dllexport) DWORD NvOptimusEnablement = 1;
+	__declspec(dllexport) DWORD AmdPowerXpressRequestHighPerformance = 1;
+}
diff --git a/src/client/std_include.hpp b/src/client/std_include.hpp
index a29aa2a6..bbb4779c 100644
--- a/src/client/std_include.hpp
+++ b/src/client/std_include.hpp
@@ -51,6 +51,7 @@
 #include <iphlpapi.h>
 #include <wincrypt.h>
 #include <shellscalingapi.h>
+#include <d3d11.h>
 
 // min and max is required by gdi, therefore NOMINMAX won't work
 #ifdef max
@@ -101,5 +102,6 @@
 #pragma comment(lib, "urlmon.lib" )
 #pragma comment(lib, "iphlpapi.lib")
 #pragma comment(lib, "Crypt32.lib")
+#pragma comment(lib, "d3d11.lib")
 
 using namespace std::literals;
diff --git a/src/common/utils/nt.cpp b/src/common/utils/nt.cpp
index c57ab267..45f3cebc 100644
--- a/src/common/utils/nt.cpp
+++ b/src/common/utils/nt.cpp
@@ -1,4 +1,5 @@
 #include "nt.hpp"
+#include "string.hpp"
 
 namespace utils::nt
 {
@@ -223,6 +224,34 @@ namespace utils::nt
 		return nullptr;
 	}
 
+	registry_key open_or_create_registry_key(const HKEY base, const std::string& input)
+	{
+		const auto parts = string::split(input, '\\');
+
+		registry_key current_key = base;
+
+		for (const auto& part : parts)
+		{
+			registry_key new_key{};
+			if (RegOpenKeyExA(current_key, part.data(), 0,
+				KEY_ALL_ACCESS, &new_key) == ERROR_SUCCESS)
+			{
+				current_key = std::move(new_key);
+				continue;
+			}
+
+			if (RegCreateKeyExA(current_key, part.data(), 0, nullptr, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS,
+				nullptr, &new_key, nullptr) != ERROR_SUCCESS)
+			{
+				return {};
+			}
+
+			current_key = std::move(new_key);
+		}
+
+		return current_key;
+	}
+
 	bool is_wine()
 	{
 		static const auto has_wine_export = []() -> bool
diff --git a/src/common/utils/nt.hpp b/src/common/utils/nt.hpp
index 02b06dc1..4ca36860 100644
--- a/src/common/utils/nt.hpp
+++ b/src/common/utils/nt.hpp
@@ -173,6 +173,77 @@ namespace utils::nt
 		HANDLE handle_{InvalidHandle};
 	};
 
+
+	class registry_key
+	{
+	public:
+		registry_key() = default;
+
+		registry_key(HKEY key)
+			: key_(key)
+		{
+		}
+
+		registry_key(const registry_key&) = delete;
+		registry_key& operator=(const registry_key&) = delete;
+
+		registry_key(registry_key&& obj) noexcept
+			: registry_key()
+		{
+			this->operator=(std::move(obj));
+		}
+
+		registry_key& operator=(registry_key&& obj) noexcept
+		{
+			if (this != obj.GetRef())
+			{
+				this->~registry_key();
+				this->key_ = obj.key_;
+				obj.key_ = nullptr;
+			}
+
+			return *this;
+		}
+
+		~registry_key()
+		{
+			if (this->key_)
+			{
+				RegCloseKey(this->key_);
+			}
+		}
+
+		operator HKEY() const
+		{
+			return this->key_;
+		}
+
+		operator bool() const
+		{
+			return this->key_ != nullptr;
+		}
+
+		HKEY* operator&()
+		{
+			return &this->key_;
+		}
+
+		registry_key* GetRef()
+		{
+			return this;
+		}
+
+		const registry_key* GetRef() const
+		{
+			return this;
+		}
+
+	private:
+		HKEY key_{};
+	};
+
+	registry_key open_or_create_registry_key(const HKEY base, const std::string& input);
+
 	bool is_wine();
 	bool is_shutdown_in_progress();