added missing files (part 2)

src/util/command_line.cpp

@@ -0,0 +1,46 @@
+#include "command_line.h"
+
+#include <filesystem>
+
+namespace fs = std::filesystem;
+
+using std::filesystem::path;
+using std::string;
+using std::cout;
+using std::cerr;
+using std::endl;
+
+bool parse_cmdline(int argc, char** argv, EnginePaths& paths) {
+	ArgsReader reader(argc, argv);
+	reader.skip();
+	while (reader.hasNext()) {
+		string token = reader.next();
+		if (reader.isKeywordArg()) {
+			if (token == "--res") {
+				token = reader.next();
+				if (!fs::is_directory(path(token))) {
+					throw std::runtime_error(token+" is not a directory");
+				}
+				paths.setResources(path(token));
+				cout << "resources folder: " << token << std::endl;
+			} else if (token == "--dir") {
+				token = reader.next();
+				if (!fs::is_directory(path(token))) {
+					fs::create_directories(path(token));
+				}
+				paths.setUserfiles(path(token));
+				cout << "userfiles folder: " << token << endl;
+			} else if (token == "--help" || token == "-h") {
+				cout << "VoxelEngine command-line arguments:" << endl;
+				cout << " --res [path] - set resources directory" << endl;
+				cout << " --dir [path] - set userfiles directory" << endl;
+				return false;
+			} else {
+				cerr << "unknown argument " << token << endl;
+			}
+		} else {
+			cerr << "unexpected token" << endl;
+		}
+	}
+	return true;
+}

src/util/command_line.h

@@ -0,0 +1,41 @@
+#ifndef UTIL_COMMAND_LINE_H_
+#define UTIL_COMMAND_LINE_H_
+
+#include <string>
+#include <iostream>
+#include <stdexcept>
+#include "../files/engine_paths.h"
+
+class ArgsReader {
+	int argc;
+	char** argv;
+	int pos = 0;
+	const char* last = "";
+public:
+	ArgsReader(int argc, char** argv) : argc(argc), argv(argv) {}
+
+	void skip() {
+		pos++;
+	}
+
+	bool hasNext() const {
+		return pos < argc;
+	}
+
+	bool isKeywordArg() const {
+		return last[0] == '-';
+	}
+
+	std::string next() {
+		if (pos >= argc) {
+			throw std::runtime_error("unexpected end");
+		}
+		last = argv[pos];
+		return argv[pos++];
+	}
+};
+
+/* @return false if engine start can*/
+extern bool parse_cmdline(int argc, char** argv, EnginePaths& paths);
+
+#endif // UTIL_COMMAND_LINE_H_