Unigine.Socket Class

//AppWorldLogic.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace UnigineApp
{
	static class Constants
	{
		// UDP port to be used
		public const int UDP_PORT = 8889;
		// UDP receive buffer size
		public const int RECV_SIZE = 7;
		// UDP send buffer size
		public const int SEND_SIZE = 7;
	}

	/// Class representing the Server Socket
	class ServerSocket
	{
		Socket socket;

		/// Server constructor
		public ServerSocket()
		{
			// creating a UDP socket
			socket = new Socket(Socket.SOCKET_TYPE.DGRAM);

			// opening a socket on the specified port with a specified broadcast address
			socket.Open("127.255.255.255", Constants.UDP_PORT);

			// setting the size of the sending buffer
			socket.Send(Constants.SEND_SIZE);

			// setting the socket as a broadcasting one
			socket.Broadcast();

			// setting the socket as a non-blocking one
			socket.Nonblock();
		}

		/// Server destructor
		~ServerSocket()
		{
			// closing the socket
			socket.Close();
		}

		/// method sending a message to a certain client
		public void send_message(short client_num, string message)
		{
			// preparing a message to be received by a client with a given client_id
			Blob blob = new Blob();
			blob.Clear();
			blob.WriteShort(client_num);
			blob.Write(Marshal.StringToHGlobalUni(message), (uint)message.Length);

			// getting message size
			var size = blob.GetSize();

			// setting current position to start
			blob.SeekSet(0);

			// sending the message
			socket.WriteStream(blob, size);

			blob.Clear();
		}
	};

	/// Class representing the Client Socket
	class ClientSocket
	{
		Socket socket;
		int id = 0;

		/// Client constructor
		public ClientSocket()
		{
			// creating a UDP socket
			socket = new Socket(Socket.SOCKET_TYPE.DGRAM);

			// opening a socket on the specified port 
			socket.Open(Constants.UDP_PORT);

			// setting the size of the receiving buffer
			socket.Recv(Constants.RECV_SIZE);

			// binding the socket to an address figured out from the host used for socket initialization
			socket.Bind();

			// setting the socket as a non-blocking one
			socket.Nonblock();
		}

		/// Client destructor
		~ClientSocket()
		{

			// closing the socket
			socket.Close();
		}

		public void setID(int num)
		{
			// setting client's ID
			id = num;
		}

		/// method checking for received packets from the server
		public int update()
		{
			// preparing a blob to read the message into
			Blob temp_blob = new Blob();
			temp_blob.Clear();

			// reading data from the socket
			socket.ReadStream(temp_blob, Constants.RECV_SIZE);

			if (temp_blob.GetSize() > 0)
			{
				// setting current position to start
				temp_blob.SeekSet(0);

				// getting client's ID
				short num_client = temp_blob.ReadShort();

				// checking if the received message is addressed to this particular client and processing it
				if (num_client == id)
					Log.Message("\nClient[{0}] - OPERATION_CODE: {1}", id, temp_blob.ReadLine());
			}
			return 1;
		}
	};

	class AppWorldLogic : WorldLogic
	{
		//declaring server and client sockets
		ServerSocket server_socket;
		ClientSocket[] clients = new ClientSocket[5];

		// World logic, it takes effect only when the world is loaded.
		// These methods are called right after corresponding world script's (UnigineScript) methods.

		public AppWorldLogic()
		{
		}

		private void Init()
		{

			server_socket = new ServerSocket();
			// Write here code to be called on world initialization: initialize resources for your world scene during the world start.
			for (int i = 0; i < 5; i++)
			{
				clients[i] = new ClientSocket();
				clients[i].setID(i + 1);
			}
		}

		// start of the main loop
		private void Update()
		{
			// sending messages on keys pressed to clients 2 and 5
			if (Input.IsKeyDown(Input.KEY.E))
				server_socket.send_message(2, "E");
			else if (Input.IsKeyDown(Input.KEY.W))
				server_socket.send_message(5, "W");
			else if (Input.IsKeyDown(Input.KEY.A))
				server_socket.send_message(5, "A");
			else if (Input.IsKeyDown(Input.KEY.S))
				server_socket.send_message(5, "S");
			else if (Input.IsKeyDown(Input.KEY.D))
				server_socket.send_message(5, "D");

			// updating clients
			for (int i = 0; i < 5; i++)
				clients[i].update();

		}

		/* ... */

	}
}