Added missing files

src/files/engine_files.cpp

@@ -0,0 +1,35 @@
+#include "engine_files.h"
+
+#include <filesystem>
+
+namespace filesystem = std::filesystem;
+using std::string;
+using filesystem::path;
+
+path enginefs::get_screenshot_file(string ext) {
+	path folder = SCREENSHOTS_FOLDER;
+	if (!filesystem::is_directory(folder)) {
+		filesystem::create_directory(folder);
+	}
+
+	auto t = std::time(nullptr);
+    auto tm = *std::localtime(&t);
+
+	const char* format = "%d-%m-%Y_%H-%M-%S";
+
+	std::stringstream ss;
+	ss << std::put_time(&tm, format);
+	string datetimestr = ss.str();
+
+	path filename = folder/("screenshot-"+datetimestr+"."+ext);
+	uint index = 0;
+	while (filesystem::exists(filename)) {
+		filename = folder/("screenshot-"+datetimestr+"-"+std::to_string(index)+"."+ext);
+		index++;
+	}
+	return filename;
+}
+
+path enginefs::get_worlds_folder() {
+    return "worlds";
+}