Merge `--gdi` handling into `ArgParser` (resolves #4201)

funny story, the `--gdi` handler didn't remove it from the `args` array,
so it's always been parsed as a rom filename and obviously failing, but
before bd58bde07 it was failing silently

src/BizHawk.Client.Common/ArgParser.cs

@@ -48,6 +48,8 @@ namespace BizHawk.Client.Common
 
 		private static readonly BespokeOption<string?> OptionConfigFilePath = new(name: "--config", description: "path of config file to use");
 
+		private static readonly BespokeOption<bool> OptionGDIPlus = new(name: "--gdi", description: "pass to use the GDI+ display method rather than whatever preference is set in the config file");
+
 		private static readonly BespokeOption<string?> OptionHTTPClientURIGET = new(aliases: [ "--url-get", "--url_get" ], description: "string; URI to use for HTTP 'GET' IPC (Lua `comm.http*Get*`)");
 
 		private static readonly BespokeOption<string?> OptionHTTPClientURIPOST = new(aliases: [ "--url-post", "--url_post" ], description: "string; URI to use for HTTP 'POST' IPC (Lua `comm.http*Post*`)");
@@ -105,6 +107,7 @@ namespace BizHawk.Client.Common
 			root.Add(/* --dump-name */ OptionAVDumpName);
 			root.Add(/* --dump-type */ OptionAVDumpType);
 			root.Add(/* --fullscreen */ OptionLaunchFullscreen);
+			root.Add(/* --gdi */ OptionGDIPlus);
 			root.Add(/* --load-slot */ OptionLoadQuicksaveSlot);
 			root.Add(/* --load-state */ OptionLoadSavestateFilePath);
 			root.Add(/* --lua */ OptionLuaFilePath);
@@ -219,6 +222,7 @@ namespace BizHawk.Client.Common
 				autoCloseOnDump: result.GetValueForOption(OptionAVDumpQuitWhenDone),
 				chromeless: result.GetValueForOption(OptionLaunchChromeless),
 				startFullscreen: result.GetValueForOption(OptionLaunchFullscreen),
+				gdiPlusRequested: result.GetValueForOption(OptionGDIPlus),
 				luaScript: luaScript,
 				luaConsole: luaConsole,
 				socketAddress: socketAddress,

src/BizHawk.Client.Common/ParsedCLIFlags.cs

@@ -31,6 +31,8 @@ namespace BizHawk.Client.Common
 
 		public readonly bool startFullscreen;
 
+		public readonly bool GDIPlusRequested;
+
 		public readonly string? luaScript;
 
 		public readonly bool luaConsole;
@@ -64,6 +66,7 @@ namespace BizHawk.Client.Common
 			bool autoCloseOnDump,
 			bool chromeless,
 			bool startFullscreen,
+			bool gdiPlusRequested,
 			string? luaScript,
 			bool luaConsole,
 			(string IP, ushort Port)? socketAddress,
@@ -87,6 +90,7 @@ namespace BizHawk.Client.Common
 			_autoCloseOnDump = autoCloseOnDump;
 			_chromeless = chromeless;
 			this.startFullscreen = startFullscreen;
+			GDIPlusRequested = gdiPlusRequested;
 			this.luaScript = luaScript;
 			this.luaConsole = luaConsole;
 			SocketAddress = socketAddress;

src/BizHawk.Client.EmuHawk/Program.cs

@@ -220,6 +220,7 @@ namespace BizHawk.Client.EmuHawk
 				initialConfig = ConfigService.Load<Config>(configPath);
 			}
 			initialConfig.ResolveDefaults();
+			if (cliFlags.GDIPlusRequested) initialConfig.DispMethod = EDispMethod.GdiPlus;
 			if (initialConfig.SaveSlot is 0) initialConfig.SaveSlot = 10; //TODO remove after a while
 			// initialConfig should really be globalConfig as it's mutable
 
@@ -307,12 +308,6 @@ namespace BizHawk.Client.EmuHawk
 				}
 			}
 
-			// super hacky! this needs to be done first. still not worth the trouble to make this system fully proper
-			if (Array.Exists(args, static arg => arg.StartsWithIgnoreCase("--gdi")))
-			{
-				initialConfig.DispMethod = EDispMethod.GdiPlus;
-			}
-
 			var workingGL = TryInitIGL(initialConfig.DispMethod);
 
 			Sound globalSound = null;