Reworked packet writer

src/main/java/fr/themode/minestom/Main.java

@@ -21,6 +21,13 @@ import java.lang.reflect.InvocationTargetException;
 
 public class Main {
 
+    // Thread number
+    public static final int THREAD_COUNT_PACKET_WRITER = 3;
+    public static final int THREAD_COUNT_CHUNK_BATCH = 2;
+    public static final int THREAD_COUNT_OBJECTS_ENTITIES = 2;
+    public static final int THREAD_COUNT_CREATURES_ENTITIES = 2;
+    public static final int THREAD_COUNT_PLAYERS_ENTITIES = 2;
+
     public static final int TICK_MS = 50;
 
     // Networking
@@ -101,12 +108,14 @@ public class Main {
             currentTime = System.nanoTime();
 
             // Keep Alive Handling
-            server.getConnections().stream().filter(connection -> packetProcessor.hasPlayerConnection(connection) && connectionManager.getPlayer(packetProcessor.getPlayerConnection(connection)) != null && System.currentTimeMillis() - connectionManager.getPlayer(packetProcessor.getPlayerConnection(connection)).getLastKeepAlive() > 20000).map(connection -> connectionManager.getPlayer(packetProcessor.getPlayerConnection(connection))).forEach(player -> {
-                long id = System.currentTimeMillis();
-                player.refreshKeepAlive(id);
-                KeepAlivePacket keepAlivePacket = new KeepAlivePacket(id);
-                player.getPlayerConnection().sendPacket(keepAlivePacket);
-            });
+            for (Player player : getConnectionManager().getOnlinePlayers()) {
+                if (System.currentTimeMillis() - player.getLastKeepAlive() > 20000) {
+                    long id = System.currentTimeMillis();
+                    player.refreshKeepAlive(id);
+                    KeepAlivePacket keepAlivePacket = new KeepAlivePacket(id);
+                    player.getPlayerConnection().sendPacket(keepAlivePacket);
+                }
+            }
 
             // Entities update
             entityManager.update();

src/main/java/fr/themode/minestom/Viewable.java

@@ -1,6 +1,7 @@
 package fr.themode.minestom;
 
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 import java.util.Set;
@@ -21,8 +22,13 @@ public interface Viewable {
         if (getViewers().isEmpty())
             return;
 
-        //Packet p = PacketUtils.writePacket(packet);
-        getViewers().forEach(player -> player.getPlayerConnection().sendPacket(packet));
+        PacketWriter.writeCallbackPacket(packet, buffer -> {
+            buffer.getData().retain(getViewers().size()).markReaderIndex();
+            getViewers().forEach(player -> {
+                player.getPlayerConnection().sendUnencodedPacket(buffer);
+                buffer.getData().resetReaderIndex();
+            });
+        });
     }
 
     default void sendPacketsToViewers(ServerPacket... packets) {
@@ -30,17 +36,29 @@ public interface Viewable {
             return;
 
         for (ServerPacket packet : packets) {
-            //Packet p = PacketUtils.writePacket(packet);
-            getViewers().forEach(player -> player.getPlayerConnection().sendPacket(packet));
+            PacketWriter.writeCallbackPacket(packet, buffer -> {
+                buffer.getData().retain(getViewers().size()).markReaderIndex();
+                getViewers().forEach(player -> {
+                    player.getPlayerConnection().sendUnencodedPacket(buffer);
+                    buffer.getData().resetReaderIndex();
+                });
+            });
         }
     }
 
     default void sendPacketToViewersAndSelf(ServerPacket packet) {
         if (this instanceof Player) {
-            //Packet p = PacketUtils.writePacket(packet);
-            ((Player) this).getPlayerConnection().sendPacket(packet);
-            if (!getViewers().isEmpty())
-                getViewers().forEach(player -> player.getPlayerConnection().sendPacket(packet));
+            PacketWriter.writeCallbackPacket(packet, buffer -> {
+                buffer.getData().retain(getViewers().size() + 1).markReaderIndex();
+                ((Player) this).getPlayerConnection().sendUnencodedPacket(buffer);
+                buffer.getData().resetReaderIndex();
+                if (!getViewers().isEmpty()) {
+                    getViewers().forEach(player -> {
+                        buffer.getData().resetReaderIndex();
+                        player.getPlayerConnection().sendUnencodedPacket(buffer);
+                    });
+                }
+            });
         }
     }
 

src/main/java/fr/themode/minestom/entity/Entity.java

@@ -225,7 +225,12 @@ public abstract class Entity implements Viewable {
 
     public void setOnFire(boolean fire) {
         this.onFire = fire;
-        sendMetadata(0);
+        sendMetadataIndex(0);
+    }
+
+    public void setNoGravity(boolean noGravity) {
+        this.noGravity = noGravity;
+        sendMetadataIndex(5);
     }
 
     public boolean isChunkUnloaded(float x, float z) {
@@ -264,12 +269,12 @@ public abstract class Entity implements Viewable {
 
     public void refreshSneaking(boolean sneaking) {
         this.crouched = sneaking;
-        sendMetadata(0);
+        sendMetadataIndex(0);
     }
 
     public void refreshSprinting(boolean sprinting) {
         this.sprinting = sprinting;
-        sendMetadata(0);
+        sendMetadataIndex(0);
     }
 
     public Position getPosition() {
@@ -302,10 +307,11 @@ public abstract class Entity implements Viewable {
         Buffer buffer = Buffer.create();
         fillMetadataIndex(buffer, 0);
         fillMetadataIndex(buffer, 1);
+        fillMetadataIndex(buffer, 5);
         return buffer;
     }
 
-    private void sendMetadata(int index) {
+    protected void sendMetadataIndex(int index) {
         Buffer buffer = Buffer.create();
         fillMetadataIndex(buffer, index);
 
@@ -329,6 +335,9 @@ public abstract class Entity implements Viewable {
             case 2:
                 fillCustomNameMetaData(buffer);
                 break;
+            case 5:
+                fillNoGravityMetaData(buffer);
+                break;
         }
     }
 
@@ -367,6 +376,12 @@ public abstract class Entity implements Viewable {
         Utils.writeString(buffer, customName);
     }
 
+    private void fillNoGravityMetaData(Buffer buffer) {
+        buffer.putByte((byte) 5);
+        buffer.putByte(METADATA_BOOLEAN);
+        buffer.putBoolean(noGravity);
+    }
+
     private boolean shouldUpdate() {
         return (float) (System.currentTimeMillis() - lastUpdate) >= Main.TICK_MS * 0.9f; // Margin of error
     }

src/main/java/fr/themode/minestom/entity/EntityManager.java

@@ -13,9 +13,9 @@ public class EntityManager {
 
     private static InstanceManager instanceManager = Main.getInstanceManager();
 
-    private ExecutorService objectsPool = Executors.newFixedThreadPool(2);
-    private ExecutorService creaturesPool = Executors.newFixedThreadPool(2);
-    private ExecutorService playersPool = Executors.newFixedThreadPool(2);
+    private ExecutorService objectsPool = Executors.newFixedThreadPool(Main.THREAD_COUNT_OBJECTS_ENTITIES);
+    private ExecutorService creaturesPool = Executors.newFixedThreadPool(Main.THREAD_COUNT_CREATURES_ENTITIES);
+    private ExecutorService playersPool = Executors.newFixedThreadPool(Main.THREAD_COUNT_PLAYERS_ENTITIES);
 
     // TODO API for custom thread division (
     public void update() {

src/main/java/fr/themode/minestom/entity/ItemEntity.java

@@ -2,6 +2,7 @@ package fr.themode.minestom.entity;
 
 import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.item.ItemStack;
+import fr.themode.minestom.net.packet.server.play.EntityRelativeMovePacket;
 import fr.themode.minestom.utils.Utils;
 
 public class ItemEntity extends ObjectEntity {
@@ -16,7 +17,11 @@ public class ItemEntity extends ObjectEntity {
 
     @Override
     public void update() {
-
+        // TODO how to keep items at the same position?
+        EntityRelativeMovePacket entityRelativeMovePacket = new EntityRelativeMovePacket();
+        entityRelativeMovePacket.entityId = getEntityId();
+        entityRelativeMovePacket.onGround = false;
+        sendPacketToViewers(entityRelativeMovePacket);
     }
 
     @Override
@@ -37,6 +42,11 @@ public class ItemEntity extends ObjectEntity {
         return itemStack;
     }
 
+    public void setItemStack(ItemStack itemStack) {
+        this.itemStack = itemStack;
+        sendMetadataIndex(7); // Refresh itemstack for viewers
+    }
+
     public boolean isPickable() {
         return pickable;
     }

src/main/java/fr/themode/minestom/entity/ObjectEntity.java

@@ -1,16 +1,9 @@
 package fr.themode.minestom.entity;
 
-import fr.themode.minestom.Viewable;
 import fr.themode.minestom.net.packet.server.play.SpawnObjectPacket;
 import fr.themode.minestom.net.player.PlayerConnection;
 
-import java.util.Collections;
-import java.util.Set;
-import java.util.concurrent.CopyOnWriteArraySet;
-
-public abstract class ObjectEntity extends Entity implements Viewable {
-
-    private Set<Player> viewers = new CopyOnWriteArraySet<>();
+public abstract class ObjectEntity extends Entity {
 
     public ObjectEntity(int entityType) {
         super(entityType);
@@ -37,9 +30,4 @@ public abstract class ObjectEntity extends Entity implements Viewable {
     public void removeViewer(Player player) {
         super.removeViewer(player);
     }
-
-    @Override
-    public Set<Player> getViewers() {
-        return Collections.unmodifiableSet(viewers);
-    }
 }

src/main/java/fr/themode/minestom/entity/Player.java

@@ -20,9 +20,9 @@ import fr.themode.minestom.world.Dimension;
 import fr.themode.minestom.world.LevelType;
 
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.CopyOnWriteArraySet;
 
 public class Player extends LivingEntity {
@@ -31,7 +31,7 @@ public class Player extends LivingEntity {
 
     private String username;
     private PlayerConnection playerConnection;
-    private LinkedList<ClientPlayPacket> packets = new LinkedList<>();
+    private ConcurrentLinkedQueue<ClientPlayPacket> packets = new ConcurrentLinkedQueue<>();
 
     private Dimension dimension;
     private GameMode gameMode;
@@ -87,6 +87,7 @@ public class Player extends LivingEntity {
                 ((EntityCreature) entity).kill();
                 sendMessage("You killed an entity!");
             }
+            sendMessage("ATTACK");
             /*UpdateHealthPacket updateHealthPacket = new UpdateHealthPacket();
             updateHealthPacket.health = -1f;
             updateHealthPacket.food = 5;
@@ -101,11 +102,9 @@ public class Player extends LivingEntity {
 
     @Override
     public void update() {
-        synchronized (packets) {
-            while (!packets.isEmpty()) {
-                ClientPlayPacket packet = packets.pollFirst();
-                packet.process(this);
-            }
+        ClientPlayPacket packet = null;
+        while ((packet = packets.poll()) != null) {
+            packet.process(this);
         }
 
         // Target block stage
@@ -422,9 +421,7 @@ public class Player extends LivingEntity {
     }
 
     public void addPacketToQueue(ClientPlayPacket packet) {
-        synchronized (packets) {
-            this.packets.add(packet);
-        }
+        this.packets.add(packet);
     }
 
     public void refreshDimension(Dimension dimension) {

src/main/java/fr/themode/minestom/entity/demo/TestArrow.java

@@ -0,0 +1,24 @@
+package fr.themode.minestom.entity.demo;
+
+import fr.themode.minestom.entity.LivingEntity;
+import fr.themode.minestom.entity.ObjectEntity;
+
+public class TestArrow extends ObjectEntity {
+
+    private LivingEntity shooter;
+
+    public TestArrow(LivingEntity shooter) {
+        super(2);
+        this.shooter = shooter;
+    }
+
+    @Override
+    public int getData() {
+        return shooter.getEntityId() + 1;
+    }
+
+    @Override
+    public void update() {
+
+    }
+}

src/main/java/fr/themode/minestom/instance/Chunk.java

@@ -1,10 +1,14 @@
 package fr.themode.minestom.instance;
 
+import fr.adamaq01.ozao.net.Buffer;
+import fr.adamaq01.ozao.net.packet.Packet;
 import fr.themode.minestom.Main;
 import fr.themode.minestom.entity.Entity;
 import fr.themode.minestom.entity.EntityCreature;
 import fr.themode.minestom.entity.ObjectEntity;
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.server.play.ChunkDataPacket;
+import fr.themode.minestom.utils.PacketUtils;
 
 import java.util.Collections;
 import java.util.Set;
@@ -26,10 +30,14 @@ public class Chunk {
     // Block entities
     private Set<Integer> blockEntities = new CopyOnWriteArraySet<>();
 
+    // Cache
+    private Buffer fullDataPacket;
+
     public Chunk(Biome biome, int chunkX, int chunkZ) {
         this.biome = biome;
         this.chunkX = chunkX;
         this.chunkZ = chunkZ;
+        //refreshDataPacket(); // TODO remove
     }
 
     protected void setBlock(byte x, byte y, byte z, short blockId) {
@@ -130,6 +138,10 @@ public class Chunk {
         return Collections.unmodifiableSet(players);
     }
 
+    public Buffer getFullDataPacket() {
+        return fullDataPacket;
+    }
+
     private boolean isBlockEntity(short blockId) {
         // TODO complete
         return blockId == 2033;
@@ -145,4 +157,20 @@ public class Chunk {
         index |= (z << 12) & 0xF000;
         return index & 0xffff;
     }
+
+    public void setFullDataPacket(Buffer fullDataPacket) {
+        this.fullDataPacket = fullDataPacket;
+    }
+
+    protected ChunkDataPacket getFreshFullDataPacket() {
+        ChunkDataPacket fullDataPacket = new ChunkDataPacket();
+        fullDataPacket.chunk = this;
+        fullDataPacket.fullChunk = true;
+        return fullDataPacket;
+    }
+
+    protected void refreshDataPacket() {
+        Packet packet = PacketUtils.writePacket(getFreshFullDataPacket());
+        this.fullDataPacket = PacketUtils.encode(packet); // TODO write packet buffer in another thread (heavy calculations)
+    }
 }

src/main/java/fr/themode/minestom/instance/ChunkBatch.java

@@ -1,5 +1,7 @@
 package fr.themode.minestom.instance;
 
+import fr.themode.minestom.Main;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.ExecutorService;
@@ -7,7 +9,7 @@ import java.util.concurrent.Executors;
 
 public class ChunkBatch implements BlockModifier {
 
-    private static volatile ExecutorService batchesPool = Executors.newFixedThreadPool(3);
+    private static volatile ExecutorService batchesPool = Executors.newFixedThreadPool(Main.THREAD_COUNT_CHUNK_BATCH);
 
     private Instance instance;
     private Chunk chunk;
@@ -47,6 +49,7 @@ public class ChunkBatch implements BlockModifier {
                 for (BlockData data : dataList) {
                     data.apply(chunk);
                 }
+                chunk.refreshDataPacket(); // TODO partial refresh instead of full
                 instance.sendChunkUpdate(chunk); // TODO partial chunk data
             });
         }

src/main/java/fr/themode/minestom/instance/Instance.java

@@ -1,10 +1,12 @@
 package fr.themode.minestom.instance;
 
+import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.Entity;
 import fr.themode.minestom.entity.EntityCreature;
 import fr.themode.minestom.entity.ObjectEntity;
 import fr.themode.minestom.entity.Player;
 import fr.themode.minestom.event.BlockBreakEvent;
+import fr.themode.minestom.net.PacketWriter;
 import fr.themode.minestom.net.packet.server.play.ChunkDataPacket;
 import fr.themode.minestom.net.packet.server.play.DestroyEntitiesPacket;
 import fr.themode.minestom.net.packet.server.play.ParticlePacket;
@@ -39,7 +41,10 @@ public class Instance implements BlockModifier {
         Chunk chunk = getChunkAt(x, z);
         synchronized (chunk) {
             chunk.setBlock((byte) (x % 16), (byte) y, (byte) (z % 16), blockId);
-            sendChunkUpdate(chunk);
+            PacketWriter.writeCallbackPacket(chunk.getFreshFullDataPacket(), buffer -> {
+                chunk.setFullDataPacket(buffer);
+                sendChunkUpdate(chunk);
+            });
         }
     }
 
@@ -48,7 +53,10 @@ public class Instance implements BlockModifier {
         Chunk chunk = getChunkAt(x, z);
         synchronized (chunk) {
             chunk.setBlock((byte) (x % 16), (byte) y, (byte) (z % 16), blockId);
-            sendChunkUpdate(chunk);
+            PacketWriter.writeCallbackPacket(chunk.getFreshFullDataPacket(), buffer -> {
+                chunk.setFullDataPacket(buffer);
+                sendChunkUpdate(chunk);
+            });
         }
     }
 
@@ -56,6 +64,7 @@ public class Instance implements BlockModifier {
         BlockBreakEvent blockBreakEvent = new BlockBreakEvent(blockPosition);
         player.callEvent(BlockBreakEvent.class, blockBreakEvent);
         if (!blockBreakEvent.isCancelled()) {
+            // TODO blockbreak setBlock result
             int x = blockPosition.getX();
             int y = blockPosition.getY();
             int z = blockPosition.getZ();
@@ -67,7 +76,7 @@ public class Instance implements BlockModifier {
             particlePacket.y = y;
             particlePacket.z = z + 0.5f;
             particlePacket.offsetX = 0.4f;
-            particlePacket.offsetY = 0.65f;
+            particlePacket.offsetY = 0.6f;
             particlePacket.offsetZ = 0.4f;
             particlePacket.particleData = 0.3f;
             particlePacket.particleCount = 75;
@@ -221,18 +230,29 @@ public class Instance implements BlockModifier {
     }
 
     protected void sendChunkUpdate(Chunk chunk) {
-        ChunkDataPacket chunkDataPacket = new ChunkDataPacket();
-        chunkDataPacket.fullChunk = false;
-        chunkDataPacket.chunk = chunk;
-        getPlayers().forEach(player -> player.getPlayerConnection().sendPacket(chunkDataPacket)); // TODO write packet buffer in another thread (Chunk packets are heavy)
+        Buffer chunkData = chunk.getFullDataPacket();
+        chunkData.getData().retain(getPlayers().size()).markReaderIndex();
+        getPlayers().forEach(player -> {
+            player.getPlayerConnection().sendUnencodedPacket(chunkData);
+            chunkData.getData().resetReaderIndex();
+        });
     }
 
     private void sendChunks(Player player) {
-        ChunkDataPacket chunkDataPacket = new ChunkDataPacket();
-        chunkDataPacket.fullChunk = true;
         for (Chunk chunk : getChunks()) {
-            chunkDataPacket.chunk = chunk;
-            player.getPlayerConnection().sendPacket(chunkDataPacket); // TODO write packet buffer in another thread (Chunk packets are heavy)
+            Buffer chunkData = chunk.getFullDataPacket();
+            if (chunkData == null) {
+                PacketWriter.writeCallbackPacket(chunk.getFreshFullDataPacket(), buffer -> {
+                    buffer.getData().retain(1).markReaderIndex();
+                    player.getPlayerConnection().sendUnencodedPacket(buffer);
+                    buffer.getData().resetReaderIndex();
+                    chunk.setFullDataPacket(buffer);
+                });
+            } else {
+                chunkData.getData().retain(1).markReaderIndex();
+                player.getPlayerConnection().sendUnencodedPacket(chunkData);
+                chunkData.getData().resetReaderIndex();
+            }
         }
     }
 

src/main/java/fr/themode/minestom/instance/demo/ChunkGeneratorDemo.java

@@ -14,10 +14,8 @@ public class ChunkGeneratorDemo extends ChunkGenerator {
     public void generateChunkData(ChunkBatch batch, int chunkX, int chunkZ) {
         for (byte x = 0; x < 16; x++)
             for (byte z = 0; z < 16; z++) {
-                if (random.nextInt(10) > 5) {
-                    batch.setBlock(x, (byte) 4, z, (short) 10);
-                } else {
-                    batch.setBlock(x, (byte) 4, z, "custom_block");
+                for (byte y = 0; y < 65; y++) {
+                    batch.setBlock(x, y, z, "custom_block");
                 }
             }
     }

src/main/java/fr/themode/minestom/listener/ChatMessageListener.java

@@ -7,6 +7,7 @@ import fr.themode.minestom.net.packet.client.play.ClientChatMessagePacket;
 public class ChatMessageListener {
 
     public static void listener(ClientChatMessagePacket packet, Player player) {
+        // TODO commands check
         Main.getConnectionManager().getOnlinePlayers().forEach(p -> p.sendMessage(String.format("<%s> %s", player.getUsername(), packet.message)));
     }
 

src/main/java/fr/themode/minestom/net/PacketProcessor.java

@@ -44,14 +44,15 @@ public class PacketProcessor {
 
     public void process(Connection connection, Packet packet) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
         int id = packet.get(PACKET_ID_IDENTIFIER);
-        if (!printBlackList.contains(id)) {
-            //System.out.println("RECEIVED ID: 0x" + Integer.toHexString(id));
-        }
         Buffer buffer = packet.getPayload();
         connectionPlayerConnectionMap.get(connection);
         PlayerConnection playerConnection = connectionPlayerConnectionMap.computeIfAbsent(connection, c -> new PlayerConnection(c));
         ConnectionState connectionState = playerConnection.getConnectionState();
 
+        if (!printBlackList.contains(id)) {
+            System.out.println("RECEIVED ID: 0x" + Integer.toHexString(id) + " State: " + connectionState);
+        }
+
         if (connectionState == ConnectionState.UNKNOWN) {
             // Should be handshake packet
             if (id == 0) {

src/main/java/fr/themode/minestom/net/PacketWriter.java

@@ -0,0 +1,24 @@
+package fr.themode.minestom.net;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.adamaq01.ozao.net.packet.Packet;
+import fr.themode.minestom.Main;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+import fr.themode.minestom.utils.PacketUtils;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.function.Consumer;
+
+public class PacketWriter {
+
+    private static volatile ExecutorService batchesPool = Executors.newFixedThreadPool(Main.THREAD_COUNT_PACKET_WRITER);
+
+    public static void writeCallbackPacket(ServerPacket serverPacket, Consumer<Buffer> consumer) {
+        batchesPool.submit(() -> {
+            Packet p = PacketUtils.writePacket(serverPacket);
+            consumer.accept(PacketUtils.encode(p));
+        });
+    }
+
+}

src/main/java/fr/themode/minestom/net/packet/client/login/LoginStartPacket.java

@@ -9,6 +9,7 @@ import fr.themode.minestom.entity.GameMode;
 import fr.themode.minestom.entity.ItemEntity;
 import fr.themode.minestom.entity.Player;
 import fr.themode.minestom.entity.demo.ChickenCreature;
+import fr.themode.minestom.entity.demo.TestArrow;
 import fr.themode.minestom.instance.Instance;
 import fr.themode.minestom.instance.demo.ChunkGeneratorDemo;
 import fr.themode.minestom.inventory.PlayerInventory;
@@ -19,6 +20,7 @@ import fr.themode.minestom.net.ConnectionState;
 import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
 import fr.themode.minestom.net.packet.server.login.JoinGamePacket;
 import fr.themode.minestom.net.packet.server.login.LoginSuccessPacket;
+import fr.themode.minestom.net.packet.server.play.DeclareCommandsPacket;
 import fr.themode.minestom.net.packet.server.play.PlayerInfoPacket;
 import fr.themode.minestom.net.packet.server.play.PlayerPositionAndLookPacket;
 import fr.themode.minestom.net.packet.server.play.SpawnPositionPacket;
@@ -31,6 +33,9 @@ import java.util.UUID;
 
 public class LoginStartPacket implements ClientPreplayPacket {
 
+    // Test
+    private static Instance instance;
+
     static {
         ChunkGeneratorDemo chunkGeneratorDemo = new ChunkGeneratorDemo();
         instance = Main.getInstanceManager().createInstance();
@@ -45,9 +50,6 @@ public class LoginStartPacket implements ClientPreplayPacket {
         System.out.println("Time to load all chunks: " + (System.currentTimeMillis() - time) + " ms");
     }
 
-    // Test
-    private static Instance instance;
-
     public String username;
 
     @Override
@@ -72,7 +74,7 @@ public class LoginStartPacket implements ClientPreplayPacket {
         Dimension dimension = Dimension.OVERWORLD;
         LevelType levelType = LevelType.DEFAULT;
         float x = 5;
-        float y = 5;
+        float y = 65;
         float z = 5;
 
         player.refreshDimension(dimension);
@@ -117,12 +119,15 @@ public class LoginStartPacket implements ClientPreplayPacket {
         playerInfoPacket.playerInfos.add(addPlayer);
         connection.sendPacket(playerInfoPacket);
 
+        // Next is optional TODO put all that somewhere else (LoginEvent)
+        // TODO LoginEvent in another thread (here we are in netty thread)
+
         player.setInstance(instance);
 
         for (int cx = 0; cx < 4; cx++)
             for (int cz = 0; cz < 4; cz++) {
                 ChickenCreature chickenCreature = new ChickenCreature();
-                chickenCreature.refreshPosition(0 + (float) cx * 1, 5, 0 + (float) cz * 1);
+                chickenCreature.refreshPosition(0 + (float) cx * 1, 65, 0 + (float) cz * 1);
                 //chickenCreature.setOnFire(true);
                 chickenCreature.setInstance(instance);
                 //chickenCreature.addPassenger(player);
@@ -144,10 +149,36 @@ public class LoginStartPacket implements ClientPreplayPacket {
         for (int ix = 0; ix < 4; ix++)
             for (int iz = 0; iz < 4; iz++) {
                 ItemEntity itemEntity = new ItemEntity(new ItemStack(1, (byte) 32));
-                itemEntity.refreshPosition(ix, 5, iz);
+                itemEntity.refreshPosition(ix, 66, iz);
+                itemEntity.setNoGravity(true);
                 itemEntity.setInstance(instance);
                 //itemEntity.remove();
             }
+
+        TestArrow arrow = new TestArrow(player);
+        arrow.refreshPosition(5, 65, 5);
+        arrow.setInstance(instance);
+        arrow.setNoGravity(true);
+
+        DeclareCommandsPacket declareCommandsPacket = new DeclareCommandsPacket();
+        DeclareCommandsPacket.Node argumentNode = new DeclareCommandsPacket.Node();
+        argumentNode.flags = 0b1010;
+        argumentNode.children = new int[0];
+        argumentNode.name = "arg name";
+        argumentNode.parser = "minecraft:nbt_path";
+        DeclareCommandsPacket.Node literalNode = new DeclareCommandsPacket.Node();
+        literalNode.flags = 0b1;
+        literalNode.children = new int[]{2};
+        literalNode.name = "hey";
+        DeclareCommandsPacket.Node rootNode = new DeclareCommandsPacket.Node();
+        rootNode.flags = 0;
+        rootNode.children = new int[]{1};
+
+        declareCommandsPacket.nodes = new DeclareCommandsPacket.Node[]{rootNode, literalNode, argumentNode};
+        declareCommandsPacket.rootIndex = 0;
+
+
+        connection.sendPacket(declareCommandsPacket);
     }
 
     @Override

src/main/java/fr/themode/minestom/net/packet/server/play/DeclareCommandsPacket.java

@@ -0,0 +1,77 @@
+package fr.themode.minestom.net.packet.server.play;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+import fr.themode.minestom.utils.Utils;
+
+import java.util.function.Consumer;
+
+public class DeclareCommandsPacket implements ServerPacket {
+
+
+    public Node[] nodes;
+    public int rootIndex;
+
+    @Override
+    public void write(Buffer buffer) {
+        Utils.writeVarInt(buffer, nodes.length);
+        for (Node node : nodes) {
+            node.write(buffer);
+        }
+        Utils.writeVarInt(buffer, rootIndex);
+    }
+
+    @Override
+    public int getId() {
+        return 0x11;
+    }
+
+    public static class Node {
+
+        public byte flags;
+        public int[] children;
+        public int redirectedNode; // Only if flags & 0x08
+        public String name; // Only for literal and argument
+        public String parser; // Only for argument
+        public Consumer<Buffer> properties; // Only for argument
+        public String suggestionsType; // Only if flags 0x10
+
+        private void write(Buffer buffer) {
+            buffer.putByte(flags);
+            Utils.writeVarInt(buffer, children.length);
+            for (int child : children) {
+                Utils.writeVarInt(buffer, child);
+            }
+
+            if ((flags & 0x08) != 0) {
+                Utils.writeVarInt(buffer, redirectedNode);
+            }
+
+            if (isLiteral() || isArgument()) {
+                Utils.writeString(buffer, name);
+            }
+
+            if (isArgument()) {
+                Utils.writeString(buffer, parser);
+                if (properties != null) {
+                    properties.accept(buffer);
+                }
+            }
+
+            if ((flags & 0x10) != 0) {
+                Utils.writeString(buffer, suggestionsType);
+            }
+
+        }
+
+        private boolean isLiteral() {
+            return (flags & 0b1) != 0;
+        }
+
+        private boolean isArgument() {
+            return (flags & 0b10) != 0;
+        }
+
+    }
+
+}

src/main/java/fr/themode/minestom/net/player/PlayerConnection.java

@@ -1,10 +1,14 @@
 package fr.themode.minestom.net.player;
 
+import fr.adamaq01.ozao.net.Buffer;
 import fr.adamaq01.ozao.net.packet.Packet;
 import fr.adamaq01.ozao.net.server.Connection;
 import fr.themode.minestom.net.ConnectionState;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.PacketUtils;
+import io.netty.channel.socket.SocketChannel;
+
+import java.lang.reflect.Field;
 
 public class PlayerConnection {
 
@@ -20,6 +24,30 @@ public class PlayerConnection {
         this.connection.sendPacket(packet);
     }
 
+
+    // TODO make that proper (remove reflection)
+    private Field field;
+
+    {
+        try {
+            field = Class.forName("fr.adamaq01.ozao.net.server.backend.tcp.TCPConnection").getDeclaredField("channel");
+        } catch (NoSuchFieldException e) {
+            e.printStackTrace();
+        } catch (ClassNotFoundException e) {
+            e.printStackTrace();
+        }
+        field.setAccessible(true);
+    }
+
+    public void sendUnencodedPacket(Buffer packet) {
+        try {
+            SocketChannel channel = ((SocketChannel) field.get(connection));
+            channel.writeAndFlush(packet.getData());
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        }
+    }
+
     public void sendPacket(ServerPacket serverPacket) {
         sendPacket(PacketUtils.writePacket(serverPacket));
     }

src/main/java/fr/themode/minestom/net/protocol/MinecraftProtocol.java

@@ -3,12 +3,12 @@ package fr.themode.minestom.net.protocol;
 import fr.adamaq01.ozao.net.Buffer;
 import fr.adamaq01.ozao.net.packet.Packet;
 import fr.adamaq01.ozao.net.protocol.Protocol;
+import fr.themode.minestom.utils.PacketUtils;
 
 import java.util.ArrayList;
 import java.util.Collection;
 
 import static fr.themode.minestom.utils.Utils.readVarInt;
-import static fr.themode.minestom.utils.Utils.writeVarInt;
 
 public class MinecraftProtocol extends Protocol {
 
@@ -29,7 +29,7 @@ public class MinecraftProtocol extends Protocol {
 
     @Override
     public boolean verify(Packet packet) {
-        return packet.get("id") != null;
+        return PacketUtils.verify(packet);
     }
 
     @Override
@@ -56,12 +56,6 @@ public class MinecraftProtocol extends Protocol {
 
     @Override
     public Buffer encode(Packet packet) {
-        Buffer buffer = Buffer.create();
-        Buffer idAndPayload = Buffer.create();
-        writeVarInt(idAndPayload, packet.get(PACKET_ID_IDENTIFIER));
-        idAndPayload.putBuffer(packet.getPayload());
-        writeVarInt(buffer, idAndPayload.length());
-        buffer.putBuffer(idAndPayload);
-        return buffer;
+        return PacketUtils.encode(packet);
     }
 }

src/main/java/fr/themode/minestom/utils/BlockPosition.java

@@ -43,6 +43,6 @@ public class BlockPosition {
 
     @Override
     public String toString() {
-        return "Position[" + x + ":" + y + ":" + z + "]";
+        return "BlockPosition[" + x + ":" + y + ":" + z + "]";
     }
 }

src/main/java/fr/themode/minestom/utils/PacketUtils.java

@@ -5,6 +5,7 @@ import fr.adamaq01.ozao.net.packet.Packet;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 import static fr.themode.minestom.net.protocol.MinecraftProtocol.PACKET_ID_IDENTIFIER;
+import static fr.themode.minestom.utils.Utils.writeVarInt;
 
 public class PacketUtils {
 
@@ -13,10 +14,22 @@ public class PacketUtils {
         Packet packet = Packet.create();
         Buffer buffer = packet.getPayload();
         serverPacket.write(buffer);
-        /*if (id != 40 && id != 64)
-            System.out.println("ID: 0x" + Integer.toHexString(id));*/
         packet.put(PACKET_ID_IDENTIFIER, id);
         return packet;
     }
 
+    public static boolean verify(Packet packet) {
+        return packet.get("id") != null;
+    }
+
+    public static Buffer encode(Packet packet) {
+        Buffer buffer = Buffer.create();
+        Buffer idAndPayload = Buffer.create();
+        writeVarInt(idAndPayload, packet.get(PACKET_ID_IDENTIFIER));
+        idAndPayload.putBuffer(packet.getPayload());
+        writeVarInt(buffer, idAndPayload.length());
+        buffer.putBuffer(idAndPayload);
+        return buffer;
+    }
+
 }

src/main/java/fr/themode/minestom/utils/Position.java

@@ -21,10 +21,20 @@ public class Position {
         this(0, 0, 0);
     }
 
+    public void add(float x, float y, float z) {
+        this.x += x;
+        this.y += y;
+        this.z += z;
+    }
+
     public float getDistance(Position position) {
         return (float) Math.sqrt(Math.pow(position.getX() - getX(), 2) + Math.pow(position.getY() - getY(), 2) + Math.pow(position.getZ() - getZ(), 2));
     }
 
+    public Position clone() {
+        return new Position(getX(), getY(), getZ(), getYaw(), getPitch());
+    }
+
     public float getX() {
         return x;
     }
@@ -64,4 +74,9 @@ public class Position {
     public void setPitch(float pitch) {
         this.pitch = pitch;
     }
+
+    @Override
+    public String toString() {
+        return "Position[" + x + ":" + y + ":" + z + "] (" + yaw + "/" + pitch + ")";
+    }
 }