Add basic location handling

- Retrieve player location from the server
- Send back player location from the server
- Requires that a specific setting is enabled
- Should allow items to be picked up by the player
- May also trigger some anti chead plugins

MinecraftClient/Protocol/Handlers/Protocol16.cs

@@ -7,6 +7,7 @@ using System.Threading;
 using MinecraftClient.Crypto;
 using MinecraftClient.Proxy;
 using System.Security.Cryptography;
+using MinecraftClient.Mapping;
 
 namespace MinecraftClient.Protocol.Handlers
 {
@@ -615,6 +616,11 @@ namespace MinecraftClient.Protocol.Handlers
             return false; //Only supported since MC 1.7
         }
 
+        public bool SendLocationUpdate(Location location, bool onGround)
+        {
+            return false; //Currently not implemented
+        }
+
         /// <summary>
         /// Send a plugin channel packet to the server.
         /// </summary>

MinecraftClient/Protocol/Handlers/Protocol18.cs

@@ -8,6 +8,7 @@ using MinecraftClient.Crypto;
 using MinecraftClient.Proxy;
 using System.Security.Cryptography;
 using MinecraftClient.Protocol.Handlers.Forge;
+using MinecraftClient.Mapping;
 
 namespace MinecraftClient.Protocol.Handlers
 {
@@ -162,6 +163,23 @@ namespace MinecraftClient.Protocol.Handlers
                     catch (IndexOutOfRangeException) { /* No message type */ }
                     handler.OnTextReceived(ChatParser.ParseText(message));
                     break;
+                case 0x08:
+                    if (Settings.TerrainAndMovements)
+                    {
+                        double x = readNextDouble(ref packetData);
+                        double y = readNextDouble(ref packetData);
+                        double z = readNextDouble(ref packetData);
+
+                        byte locMask = readNextByte(ref packetData);
+                        Location location = handler.GetCurrentLocation();
+
+                        location.X = (locMask & 1 << 0) != 0 ? location.X + x : x;
+                        location.Y = (locMask & 1 << 1) != 0 ? location.Y + y : y;
+                        location.Z = (locMask & 1 << 2) != 0 ? location.Z + z : z;
+
+                        handler.UpdateLocation(location);
+                    }
+                    break;
                 case 0x38: //Player List update
                     if (protocolversion >= MC18Version)
                     {
@@ -509,6 +527,18 @@ namespace MinecraftClient.Protocol.Handlers
             return readData(len, ref cache);
         }
 
+        /// <summary>
+        /// Read a double from a cache of bytes and remove it from the cache
+        /// </summary>
+        /// <returns>The double value</returns>
+
+        private static double readNextDouble(ref byte[] cache)
+        {
+            byte[] rawValue = readData(8, ref cache);
+            Array.Reverse(rawValue); //Endianness
+            return BitConverter.ToDouble(rawValue, 0);
+        }
+
         /// <summary>
         /// Read an integer from the network
         /// </summary>
@@ -602,6 +632,19 @@ namespace MinecraftClient.Protocol.Handlers
             return bytes.ToArray();
         }
 
+        /// <summary>
+        /// Get byte array representing a double
+        /// </summary>
+        /// <param name="array">Array to process</param>
+        /// <returns>Array ready to send</returns>
+
+        private byte[] getDouble(double number)
+        {
+            byte[] theDouble = BitConverter.GetBytes(number);
+            Array.Reverse(theDouble); //Endianness
+            return theDouble;
+        }
+
         /// <summary>
         /// Get byte array with length information prepended to it
         /// </summary>
@@ -931,6 +974,29 @@ namespace MinecraftClient.Protocol.Handlers
             return SendPluginChannelPacket("MC|Brand", getString(brandInfo));
         }
 
+        /// <summary>
+        /// Send a location update to the server
+        /// </summary>
+        /// <param name="location">The new location of the player</param>
+        /// <param name="onGround">True if the player is on the ground</param>
+        /// <returns>True if the location update was successfully sent</returns>
+
+        public bool SendLocationUpdate(Location location, bool onGround)
+        {
+            if (Settings.TerrainAndMovements)
+            {
+                try
+                {
+                    SendPacket(0x04, concatBytes(
+                        getDouble(location.X), getDouble(location.X), getDouble(location.X),
+                        new byte[] { onGround ? (byte)1 : (byte)0 }));
+                    return true;
+                }
+                catch (SocketException) { return false; }
+            }
+            else return false;
+        }
+
         /// <summary>
         /// Send a plugin channel packet (0x17) to the server, compression and encryption will be handled automatically
         /// </summary>

MinecraftClient/Protocol/IMinecraftCom.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using MinecraftClient.Crypto;
+using MinecraftClient.Mapping;
 
 namespace MinecraftClient.Protocol
 {
@@ -45,7 +46,7 @@ namespace MinecraftClient.Protocol
         bool SendRespawnPacket();
 
         /// <summary>
-        /// Tell the server what client is being used to connect to the server
+        /// Inform the server of the client being used to connect
         /// </summary>
         /// <param name="brandInfo">Client string describing the client</param>
         /// <returns>True if brand info was successfully sent</returns>
@@ -53,10 +54,17 @@ namespace MinecraftClient.Protocol
         bool SendBrandInfo(string brandInfo);
 
         /// <summary>
-        /// Send a plugin channel packet to the server.
-        ///
-        /// http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/
+        /// Send a location update telling that we moved to that location
         /// </summary>
+        /// <param name="location">The new location</param>
+        /// <returns>True if packet was successfully sent</returns>
+
+        bool SendLocationUpdate(Location location, bool onGround);
+
+        /// <summary>
+        /// Send a plugin channel packet to the server.
+        /// </summary>
+        /// <see href="http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/" />
         /// <param name="channel">Channel to send packet on</param>
         /// <param name="data">packet Data</param>
         /// <returns>True if message was successfully sent</returns>

MinecraftClient/Protocol/IMinecraftComHandler.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using MinecraftClient.Mapping;
 
 namespace MinecraftClient.Protocol
 {
@@ -22,6 +23,7 @@ namespace MinecraftClient.Protocol
         string GetUserUUID();
         string GetSessionID();
         string[] GetOnlinePlayers();
+        Location GetCurrentLocation();
 
         /// <summary>
         /// Called when a server was successfully joined
@@ -50,6 +52,13 @@ namespace MinecraftClient.Protocol
 
         void OnPlayerLeave(Guid uuid);
 
+        /// <summary>
+        /// Called when the server sets the new location for the player
+        /// </summary>
+        /// <param name="location">New location of the player</param>
+
+        void UpdateLocation(Location location);
+
         /// <summary>
         /// This method is called when the connection has been lost
         /// </summary>