system: add console language conf

src/main.cpp

@@ -10,6 +10,7 @@
 #include "emulator.h"
 #include "kytyGitVersion.h"
 
+#include <charconv>
 #include <cstdio>
 #include <fmt/format.h>
 
@@ -47,6 +48,7 @@ static void PrintUsage() {
 	::printf("  --screen-width <num>                 Window width. Default: 1280.\n");
 	::printf("  --screen-height <num>                Window height. Default: 720.\n");
 	::printf("  --vblank-frequency <num>             Virtual vblank frequency. Default: 60.\n");
+	::printf("  --console-language <0-29>            Console language. Default: 1 (English US).\n");
 	::printf("  --vulkan-validation <true|false>     Enable Vulkan validation.\n");
 	::printf("  --shader-validation <true|false>     Enable shader validation.\n");
 	::printf("  --shader-optimization-type <value>   None, Size, or Performance.\n");
@@ -101,6 +103,17 @@ static bool ParseEnum(const std::string& value, E& out) {
 	return true;
 }
 
+static bool ParseConsoleLanguage(const std::string& value, uint32_t& out) {
+	uint32_t language = 0;
+	auto [end, error] = std::from_chars(value.data(), value.data() + value.size(), language);
+	if (error != std::errc {} || end != value.data() + value.size() ||
+	    language > Config::MAX_CONSOLE_LANGUAGE) {
+		return false;
+	}
+	out = language;
+	return true;
+}
+
 static bool ParseArgs(int argc, char* argv[], RunOptions& options, bool& show_help) {
 	show_help = false;
 
@@ -167,6 +180,11 @@ static bool ParseArgs(int argc, char* argv[], RunOptions& options, bool& show_he
 			const int32_t vblank_frequency = Common::ToInt32(value);
 			options.config.vblank_frequency =
 			    static_cast<uint32_t>(vblank_frequency < 0 ? 0 : vblank_frequency);
+		} else if (arg == "--console-language") {
+			if (!ParseConsoleLanguage(value, options.config.console_language)) {
+				::printf("invalid console language: %s\n", value.c_str());
+				return false;
+			}
 		} else if (arg == "--vulkan-validation") {
 			if (!ParseBool(value, options.config.vulkan_validation_enabled)) {
 				::printf("invalid boolean for %s: %s\n", arg.c_str(), value.c_str());