feat(proxy): add shell api; add --disable-ue4ss command line/launch arg

Author: narknon

README.md

@@ -27,7 +27,11 @@ The easiest installation is via downloading the non-dev version of the latest no
 
 If your game is in the custom config list, extract the contents from the relevant folder to `Win64` as well.
 
-If you are planning on doing mod development using UE4SS, you can do the same as above but download the zDEV version instead. 
+If you are planning on doing mod development using UE4SS, you can do the same as above but download the zDEV version instead.
+
+### Disabling UE4SS Temporarily
+
+If RE-UE4SS is installed via proxy DLL, you can temporarily disable it without uninstalling by launching the game with the `--disable-ue4ss` command line argument. 
 
 ## Links
 

UE4SS/proxy_generator/main.cpp

@@ -209,9 +209,11 @@ int _tmain(int argc, TCHAR* argv[])
     cpp_file << endl;
     cpp_file << "#define WIN32_LEAN_AND_MEAN" << endl;
     cpp_file << "#include <Windows.h>" << endl;
+    cpp_file << "#include <shellapi.h>" << endl;
     cpp_file << "#include <filesystem>" << endl;
     cpp_file << endl;
     cpp_file << "#pragma comment(lib, \"user32.lib\")" << endl;
+    cpp_file << "#pragma comment(lib, \"shell32.lib\")" << endl;
     cpp_file << endl;
 
     cpp_file << "using namespace RC;" << endl;
@@ -256,6 +258,30 @@ int _tmain(int argc, TCHAR* argv[])
     cpp_file << "}" << endl;
     cpp_file << endl;
 
+    cpp_file << "bool should_disable_ue4ss()" << endl;
+    cpp_file << "{" << endl;
+    cpp_file << "    int argc = 0;" << endl;
+    cpp_file << "    LPWSTR* argv = CommandLineToArgvW(GetCommandLineW(), &argc);" << endl;
+    cpp_file << "    if (!argv)" << endl;
+    cpp_file << "    {" << endl;
+    cpp_file << "        return false;" << endl;
+    cpp_file << "    }" << endl;
+    cpp_file << endl;
+    cpp_file << "    bool disable = false;" << endl;
+    cpp_file << "    for (int i = 0; i < argc; i++)" << endl;
+    cpp_file << "    {" << endl;
+    cpp_file << "        if (wcscmp(argv[i], L\"--disable-ue4ss\") == 0)" << endl;
+    cpp_file << "        {" << endl;
+    cpp_file << "            disable = true;" << endl;
+    cpp_file << "            break;" << endl;
+    cpp_file << "        }" << endl;
+    cpp_file << "    }" << endl;
+    cpp_file << endl;
+    cpp_file << "    LocalFree(argv);" << endl;
+    cpp_file << "    return disable;" << endl;
+    cpp_file << "}" << endl;
+    cpp_file << endl;
+
     cpp_file << "HMODULE load_ue4ss_dll(HMODULE moduleHandle)" << endl;
     cpp_file << "{" << endl;
     cpp_file << "    HMODULE hModule = nullptr;" << endl;
@@ -308,12 +334,17 @@ int _tmain(int argc, TCHAR* argv[])
     cpp_file << "    if (fdwReason == DLL_PROCESS_ATTACH)" << endl;
     cpp_file << "    {" << endl;
     cpp_file << "        load_original_dll();" << endl;
-    cpp_file << "        HMODULE hUE4SSDll = load_ue4ss_dll(hInstDll);" << endl;
-    cpp_file << "        if (hUE4SSDll)" << endl;
+    cpp_file << "        setup_functions();" << endl;
+    cpp_file << endl;
+    cpp_file << "        // Check if UE4SS should be disabled via command line argument" << endl;
+    cpp_file << "        if (should_disable_ue4ss())" << endl;
     cpp_file << "        {" << endl;
-    cpp_file << "            setup_functions();" << endl;
+    cpp_file << "            // UE4SS is disabled, proxy will still forward calls to original DLL" << endl;
+    cpp_file << "            return TRUE;" << endl;
     cpp_file << "        }" << endl;
-    cpp_file << "        else" << endl;
+    cpp_file << endl;
+    cpp_file << "        HMODULE hUE4SSDll = load_ue4ss_dll(hInstDll);" << endl;
+    cpp_file << "        if (!hUE4SSDll)" << endl;
     cpp_file << "        {" << endl;
     cpp_file << "            MessageBox(nullptr, L\"Failed to load UE4SS.dll. Please see the docs on correct installation: "
                 "https://docs.ue4ss.com/installation-guide\", L\"UE4SS Error\", MB_OK | MB_ICONERROR);"

assets/Changelog.md

@@ -20,6 +20,8 @@ Added support for UE Version 5.4 - ([UE4SS #503](https://github.com/UE4SS-RE/RE-
 Added basic support for Development/Debug/Test built Unreal Engine games ([UE4SS #607](https://github.com/UE4SS-RE/RE-UE4SS/pull/607)) 
 - To use this functionality, set DebugBuild to true in UE4SS-Settings.ini 
 
+Added command line option to disable RE-UE4SS loading via proxy DLL. Use `--disable-ue4ss` to launch game without UE4SS while keeping the proxy DLL installed. ([UE4SS #1069](https://github.com/UE4SS-RE/RE-UE4SS/pull/1069))
+
 Added new build definition "LessEqual421".  Using this definition for games on UE<=4.21 is not mandatory for UE4SS to function, but will ensure the correct alignment is used in containers. 
 
 **BREAKING:** - This also changes the default FName alignment from 8 to 4.