Add command line arguments to headless samples

Those samples can now toggle between glsl and hlsl shaders
Moved command line parster to a separate header

base/CommandLineParser.hpp

@@ -0,0 +1,117 @@
+/*
+ * Simple command line parse
+ *
+ * Copyright (C) 2016-2022 by Sascha Willems - www.saschawillems.de
+ *
+ * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
+ */
+
+#pragma once
+
+#include <vector>
+#include <unordered_map>
+#include <string>
+
+class CommandLineParser
+{
+public:
+	struct CommandLineOption {
+		std::vector<std::string> commands;
+		std::string value;
+		bool hasValue = false;
+		std::string help;
+		bool set = false;
+	};
+	std::unordered_map<std::string, CommandLineOption> options;
+
+	void add(std::string name, std::vector<std::string> commands, bool hasValue, std::string help)
+	{
+		options[name].commands = commands;
+		options[name].help = help;
+		options[name].set = false;
+		options[name].hasValue = hasValue;
+		options[name].value = "";
+	}
+
+	void printHelp()
+	{
+		std::cout << "Available command line options:\n";
+		for (auto option : options) {
+			std::cout << " ";
+			for (size_t i = 0; i < option.second.commands.size(); i++) {
+				std::cout << option.second.commands[i];
+				if (i < option.second.commands.size() - 1) {
+					std::cout << ", ";
+				}
+			}
+			std::cout << ": " << option.second.help << "\n";
+		}
+		std::cout << "Press any key to close...";
+	}
+
+	void parse(std::vector<const char*> arguments)
+	{
+		bool printHelp = false;
+		// Known arguments
+		for (auto& option : options) {
+			for (auto& command : option.second.commands) {
+				for (size_t i = 0; i < arguments.size(); i++) {
+					if (strcmp(arguments[i], command.c_str()) == 0) {
+						option.second.set = true;
+						// Get value
+						if (option.second.hasValue) {
+							if (arguments.size() > i + 1) {
+								option.second.value = arguments[i + 1];
+							}
+							if (option.second.value == "") {
+								printHelp = true;
+								break;
+							}
+						}
+					}
+				}
+			}
+		}
+		// Print help for unknown arguments or missing argument values
+		if (printHelp) {
+			options["help"].set = true;
+		}
+	}
+
+	void parse(int argc, char* argv[])
+	{
+		std::vector<const char*> args;
+		for (int i = 0; i < __argc; i++) { 
+			args.push_back(__argv[i]); 
+		};
+		parse(args);
+	}
+
+	bool isSet(std::string name)
+	{
+		return ((options.find(name) != options.end()) && options[name].set);
+	}
+
+	std::string getValueAsString(std::string name, std::string defaultValue)
+	{
+		assert(options.find(name) != options.end());
+		std::string value = options[name].value;
+		return (value != "") ? value : defaultValue;
+	}
+
+	int32_t getValueAsInt(std::string name, int32_t defaultValue)
+	{
+		assert(options.find(name) != options.end());
+		std::string value = options[name].value;
+		if (value != "") {
+			char* numConvPtr;
+			int32_t intVal = strtol(value.c_str(), &numConvPtr, 10);
+			return (intVal > 0) ? intVal : defaultValue;
+		}
+		else {
+			return defaultValue;
+		}
+		return int32_t();
+	}
+
+};