From 7c731368afae3c94c499554686c39188b87dc374 Mon Sep 17 00:00:00 2001
From: momo5502 <mauriceheumann@gmail.com>
Date: Wed, 9 Jan 2019 00:40:04 +0100
Subject: [PATCH] Allow launching complementary games via the menu

---
 src/loader/module.hpp        |  5 +++
 src/loader/module_loader.cpp | 16 ++++++++++
 src/loader/module_loader.hpp |  2 ++
 src/main.cpp                 |  2 +-
 src/module/game_launcher.cpp | 59 ++++++++++++++++++++++++++++++++++++
 5 files changed, 83 insertions(+), 1 deletion(-)
 create mode 100644 src/module/game_launcher.cpp

diff --git a/src/loader/module.hpp b/src/loader/module.hpp
index 10938f5..49c344e 100644
--- a/src/loader/module.hpp
+++ b/src/loader/module.hpp
@@ -18,4 +18,9 @@ public:
 	virtual void pre_destroy()
 	{
 	}
+
+	virtual void* load_import(const std::string& module, const std::string& function)
+	{
+		return nullptr;
+	}
 };
diff --git a/src/loader/module_loader.cpp b/src/loader/module_loader.cpp
index 615c9e1..bce9176 100644
--- a/src/loader/module_loader.cpp
+++ b/src/loader/module_loader.cpp
@@ -68,6 +68,22 @@ void module_loader::pre_destroy()
 	}
 }
 
+void* module_loader::load_import(const std::string& module, const std::string& function)
+{
+	void* function_ptr = nullptr;
+
+	for (const auto& module_ : *modules_)
+	{
+		const auto module_function_ptr = module_->load_import(module, function);
+		if(module_function_ptr)
+		{
+			function_ptr = module_function_ptr;
+		}
+	}
+
+	return function_ptr;
+}
+
 void module_loader::destroy_modules()
 {
 	pre_destroy();
diff --git a/src/loader/module_loader.hpp b/src/loader/module_loader.hpp
index ae27493..9477f6e 100644
--- a/src/loader/module_loader.hpp
+++ b/src/loader/module_loader.hpp
@@ -30,6 +30,8 @@ public:
 	static bool post_load();
 	static void pre_destroy();
 
+	static void* load_import(const std::string& module, const std::string& function);
+
 	static void trigger_premature_shutdown();
 
 private:
diff --git a/src/main.cpp b/src/main.cpp
index 4d582f0..31bd3e8 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -74,7 +74,7 @@ FARPROC load_binary(const launcher::mode mode)
 			return FARPROC(exit_hook);
 		}
 
-		return nullptr;
+		return FARPROC(module_loader::load_import(module, function));
 	});
 
 	return loader.load(self);
diff --git a/src/module/game_launcher.cpp b/src/module/game_launcher.cpp
new file mode 100644
index 0000000..7fe9dd7
--- /dev/null
+++ b/src/module/game_launcher.cpp
@@ -0,0 +1,59 @@
+#include <std_include.hpp>
+#include "loader/module_loader.hpp"
+#include "utils/nt.hpp"
+#include "utils/string.hpp"
+#include "game/game.hpp"
+
+class game_launcher final : public module
+{
+public:
+	void* load_import(const std::string& module, const std::string& function) override
+	{
+		if (utils::string::to_lower(module) == "shell32.dll" && function == "ShellExecuteA")
+		{
+			return shell_execute_a;
+		}
+
+		return nullptr;
+	}
+
+private:
+	static HINSTANCE __stdcall shell_execute_a(const HWND hwnd, const LPCSTR lp_operation, const LPCSTR lp_file,
+	                                 const LPCSTR lp_parameters, const LPCSTR lp_directory, INT n_show_cmd)
+	{
+		static const auto sp_url = "steam://run/42680"s;
+		static const auto mp_url = "steam://run/42690"s;
+
+		if (lp_file && (sp_url == lp_file || mp_url == lp_file))
+		{
+			launch_game(sp_url == lp_file);
+			return HINSTANCE(33);
+		}
+
+		return ShellExecuteA(hwnd, lp_operation, lp_file, lp_parameters, lp_directory, n_show_cmd);
+	}
+
+
+	static void launch_game(const bool singleplayer)
+	{
+		utils::nt::module self;
+
+		STARTUPINFOA s_info;
+		PROCESS_INFORMATION p_info;
+
+		ZeroMemory(&s_info, sizeof(s_info));
+		ZeroMemory(&p_info, sizeof(p_info));
+		s_info.cb = sizeof(s_info);
+
+		const auto path = self.get_path();
+		std::string cmdline = utils::string::va("\"%s\" %s", path.data(),
+		                                        singleplayer ? "-singleplayer" : "-multiplayer");
+
+		CreateProcessA(path.data(), cmdline.data(), nullptr, nullptr, false, NULL, nullptr, nullptr, &s_info, &p_info);
+
+		if (p_info.hThread && p_info.hThread != INVALID_HANDLE_VALUE) CloseHandle(p_info.hThread);
+		if (p_info.hProcess && p_info.hProcess != INVALID_HANDLE_VALUE) CloseHandle(p_info.hProcess);
+	}
+};
+
+REGISTER_MODULE(game_launcher)