Enable mode selection via arguments

src/main.cpp

@@ -5,6 +5,7 @@
 #include "game/game.hpp"
 #include "loader/binary_loader.hpp"
 #include "utils/string.hpp"
+#include "utils/flags.hpp"
 
 //#define GENERATE_DIFFS
 
@@ -37,6 +38,26 @@ void verify_tls()
 	}
 }
 
+launcher::mode detect_mode_from_arguments()
+{
+	if (utils::flags::has_flag("dedicated"))
+	{
+		return launcher::mode::server;
+	}
+
+	if (utils::flags::has_flag("multiplayer"))
+	{
+		return launcher::mode::multiplayer;
+	}
+
+	if (utils::flags::has_flag("singleplayer"))
+	{
+		return launcher::mode::singleplayer;
+	}
+
+	return launcher::mode::none;
+}
+
 FARPROC load_binary(const launcher::mode mode)
 {
 	loader loader(mode);
@@ -64,10 +85,10 @@ int main()
 	FARPROC entry_point;
 
 	{
-		bool premature_shutdown = true;
-		const auto _ = gsl::finally( [&premature_shutdown]()
+		auto premature_shutdown = true;
+		const auto _ = gsl::finally([&premature_shutdown]()
 		{
-			if(premature_shutdown)
+			if (premature_shutdown)
 			{
 				module_loader::pre_destroy();
 			}
@@ -83,9 +104,13 @@ int main()
 			verify_tls();
 			if (!module_loader::post_start()) return 0;
 
+			auto mode = detect_mode_from_arguments();
+			if (mode == launcher::mode::none)
+			{
 				launcher launcher;
-			const auto mode = launcher.run();
+				mode = launcher.run();
 				if (mode == launcher::mode::none) return 0;
+			}
 
 			entry_point = load_binary(mode);
 			if (!entry_point)

src/std_include.hpp

@@ -16,6 +16,7 @@
 #include <Ws2tcpip.h>
 #include <corecrt_io.h>
 #include <fcntl.h>
+#include <shellapi.h>
 
 // min and max is required by gdi, therefore NOMINMAX won't work
 #ifdef max

src/utils/flags.cpp

@@ -0,0 +1,52 @@
+#include <std_include.hpp>
+#include "flags.hpp"
+#include "string.hpp"
+
+namespace utils
+{
+	namespace flags
+	{
+		void parse_flags(std::vector<std::string>& flags)
+		{
+			int num_args;
+			const auto argv = CommandLineToArgvW(GetCommandLineW(), &num_args);
+
+			flags.clear();
+
+			if (argv)
+			{
+				for (auto i = 0; i < num_args; ++i)
+				{
+					std::wstring wide_flag(argv[i]);
+					if (wide_flag[0] == L'-')
+					{
+						flags.emplace_back(wide_flag.begin() + 1, wide_flag.end());
+					}
+				}
+
+				LocalFree(argv);
+			}
+		}
+
+		bool has_flag(const std::string& flag)
+		{
+			static auto parsed = false;
+			static std::vector<std::string> enabled_flags;
+
+			if (!parsed)
+			{
+				parse_flags(enabled_flags);
+			}
+
+			for (const auto& entry : enabled_flags)
+			{
+				if (string::to_lower(entry) == string::to_lower(flag))
+				{
+					return true;
+				}
+			}
+
+			return false;
+		}
+	}
+}

src/utils/flags.hpp

@@ -0,0 +1,10 @@
+#pragma once
+#include "memory.hpp"
+
+namespace utils
+{
+	namespace flags
+	{
+		bool has_flag(const std::string& flag);
+	}
+}