From 4ead72747b72e3218172cde47388f26bfb7141c7 Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Sun, 13 Jul 2025 16:06:40 +1000
Subject: [PATCH] D3DCommon: Load dxgi.lib dynamically

---
 src/util/CMakeLists.txt |  2 +-
 src/util/d3d_common.cpp | 22 +++++++++++++++++++++-
 src/util/util.props     |  2 +-
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index 7b0dced0a..5e3c48a9a 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -241,7 +241,7 @@ if(WIN32)
     xinput_source.h
   )
   target_link_libraries(util PRIVATE d3d12ma)
-  target_link_libraries(util PRIVATE d3d12.lib dxgi.lib winmm.lib Dwmapi.lib winhttp.lib)
+  target_link_libraries(util PRIVATE d3d12.lib winmm.lib Dwmapi.lib winhttp.lib)
 
   if(CMAKE_BUILD_TYPE MATCHES "Debug|Devel")
     target_link_libraries(util PRIVATE WinPixEventRuntime::WinPixEventRuntime)
diff --git a/src/util/d3d_common.cpp b/src/util/d3d_common.cpp
index 353d7d84b..0fe8e93fd 100644
--- a/src/util/d3d_common.cpp
+++ b/src/util/d3d_common.cpp
@@ -35,6 +35,8 @@ struct FeatureLevelTableEntry
 struct Libs
 {
   std::mutex load_mutex;
+  DynamicLibrary dxgi_library;
+  decltype(&CreateDXGIFactory2) CreateDXGIFactory2;
   DynamicLibrary d3d11_library;
   PFN_D3D11_CREATE_DEVICE D3D11CreateDevice;
   DynamicLibrary d3dcompiler_library;
@@ -127,12 +129,30 @@ D3D_FEATURE_LEVEL D3DCommon::GetDeviceMaxFeatureLevel(IDXGIAdapter1* adapter)
 
 Microsoft::WRL::ComPtr<IDXGIFactory5> D3DCommon::CreateFactory(bool debug, Error* error)
 {
+  if (!s_libs.dxgi_library.IsOpen())
+  {
+    // another thread may have opened it
+    const std::unique_lock lock(s_libs.load_mutex);
+    if (!s_libs.d3d11_library.IsOpen())
+    {
+      if (!s_libs.dxgi_library.Open("dxgi.dll", error))
+        return {};
+
+      if (!s_libs.dxgi_library.GetSymbol("CreateDXGIFactory2", &s_libs.CreateDXGIFactory2))
+      {
+        Error::SetStringView(error, "Failed to load CreateDXGIFactory2 from dxgi.dll");
+        s_libs.dxgi_library.Close();
+        return {};
+      }
+    }
+  }
+
   UINT flags = 0;
   if (debug)
     flags |= DXGI_CREATE_FACTORY_DEBUG;
 
   Microsoft::WRL::ComPtr<IDXGIFactory5> factory;
-  const HRESULT hr = CreateDXGIFactory2(flags, IID_PPV_ARGS(factory.GetAddressOf()));
+  const HRESULT hr = s_libs.CreateDXGIFactory2(flags, IID_PPV_ARGS(factory.GetAddressOf()));
   if (FAILED(hr))
     Error::SetHResult(error, "Failed to create DXGI factory: ", hr);
 
diff --git a/src/util/util.props b/src/util/util.props
index 85fb12d9d..6aebff885 100644
--- a/src/util/util.props
+++ b/src/util/util.props
@@ -13,7 +13,7 @@
 
   <ItemDefinitionGroup>
     <Link>
-      <AdditionalDependencies>%(AdditionalDependencies);d3d12.lib;dxgi.lib;Dwmapi.lib;winhttp.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);d3d12.lib;Dwmapi.lib;winhttp.lib</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>