ServerUDP Example

/**
 * ServerUDP.cs
 * Created by: Jadson Almeida [jadson.sistemas@gmail.com]
 * Created on: 19/10/2017 (dd/mm/yy)
 */

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;

/// <summary>
/// Simple example for a server UDP receive and send data
/// </summary>
public class ServerUDP {

    /// <summary>
    /// UDP connection to send data
    /// </summary>
    UdpClient udpSend;
    /// <summary>
    /// UDP connection to receive data
    /// </summary>
    UdpClient udpReceive;
    /// <summary>
    /// IP end point used to send data in UDP connection
    /// </summary>
    IPEndPoint ipEndPointSend;
    /// <summary>
    /// IP end point used to receive data in UDP connection
    /// </summary>
    IPEndPoint ipEndPointReceive;
    /// <summary>
    /// Port used to send data in UDP connection
    /// </summary>
    int portToSend;
    /// <summary>
    /// Port used to send data in UDP connection
    /// </summary>
    int portToReceive;
    /// <summary>
    /// Thread used to listener UDP connection with <see cref="ReceiveData"/>
    /// </summary>
    Thread thread;

    public ServerUDP()
    {
        // Creates a UDP connection to send data
        ipEndPointSend = new IPEndPoint(IPAddress.Parse("127.0.0.1"), portToSend);
        udpSend = new UdpClient();
        // Creates a UDP connection to receive data
        ipEndPointReceive = new IPEndPoint(IPAddress.Any, portToReceive);
        udpReceive = new UdpClient()
        {
            ExclusiveAddressUse = false
        };
        udpReceive.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
        udpReceive.Client.Bind(ipEndPointReceive);
        // Start thread to listen received data
        thread = new Thread(new ThreadStart(ListeningData));
        thread.Start();
    }

    /// <summary>
    /// (Used as thread) Listen external input from UDP and pass to <see cref="ReceiveData(IAsyncResult)"/>
    /// </summary>
    void ListeningData()
    {
        try
        {
            udpReceive.BeginReceive(new AsyncCallback(ReceiveData), null);
        }
        catch (Exception err)
        {
        }
    }

    /// <summary>
    /// Receive the data from clients and pass it to <see cref="HandleData(byte[])"/>
    /// </summary>
    /// <param name="res"></param>
    void ReceiveData(IAsyncResult res)
    {
        IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, portToReceive);
        byte[] received = udpReceive.EndReceive(res, ref RemoteIpEndPoint);
        HandleData(received);
        ListeningData(); // repeat
    }

    /// <summary>
    /// Handles what data means with <see cref="CalculatePhysics(byte)"/>
    /// </summary>
    /// <param name="data">data to pass to <see cref=""/></param>
    void HandleData(byte[] data)
    {
        // Check if data is wrong
        if (data.Length > 0 && data[0] > 0)
            CalculatePhysics(data[0]);
    }

    /// <summary>
    /// Calculate physic movement based in external input and pass the movement to be sended with <see cref="SendCommand(byte[])"/>
    /// </summary>
    /// <param name="inputs">External input (client UDP)</param>
    void CalculatePhysics(byte inputs)
    {
        byte[] data;
        // calculate what we need to do with the player input
        // ...
        // transform the new position, rotation etc in byte array like this:
        // index: 0 to 3 are values of the front, 4 to 7 are values of the side, 8 to 11 are up, 12 to 15 are x-axis, 16 to 19 are y-axis, 20 to 23 are z-axis,
        // 24 to 27 are board port, 28 to 31 are starboard, 32 to 35 are wing angle, and 36 to 39 are sail angle
        // ...
        // Calls send command

        SendCommand(data);
    }

    /// <summary>
    /// Sends data for client in <see cref="ipEndPointSend"/>
    /// </summary>
    /// <param name="data">data to send</param>
    void SendCommand(byte[] data)
    {
        try
        {
            udpSend.Send(data, data.Length, ipEndPointSend);
        }
        catch (Exception err)
        {
            print(err.ToString());
        }
    }
}