Updated packets reader/writer

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

@@ -1,7 +1,7 @@
 package fr.themode.minestom;
 
 import fr.themode.minestom.entity.Player;
-import fr.themode.minestom.net.PacketWriter;
+import fr.themode.minestom.net.PacketWriterUtils;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 import java.util.Set;
@@ -22,7 +22,7 @@ public interface Viewable {
         if (getViewers().isEmpty())
             return;
 
-        PacketWriter.writeCallbackPacket(packet, buffer -> {
+        PacketWriterUtils.writeCallbackPacket(packet, buffer -> {
             int size = getViewers().size();
             if (size == 0)
                 return;
@@ -39,7 +39,7 @@ public interface Viewable {
             return;
 
         for (ServerPacket packet : packets) {
-            PacketWriter.writeCallbackPacket(packet, buffer -> {
+            PacketWriterUtils.writeCallbackPacket(packet, buffer -> {
                 int size = getViewers().size();
                 if (size == 0)
                     return;
@@ -61,7 +61,7 @@ public interface Viewable {
     }
 
     private void UNSAFE_sendPacketToViewersAndSelf(ServerPacket packet) {
-        PacketWriter.writeCallbackPacket(packet, buffer -> {
+        PacketWriterUtils.writeCallbackPacket(packet, buffer -> {
             int size = getViewers().size();
             buffer.getData().retain(size + 1).markReaderIndex();
             ((Player) this).getPlayerConnection().writeUnencodedPacket(buffer);

src/main/java/fr/themode/minestom/collision/BoundingBox.java

@@ -1,6 +1,8 @@
 package fr.themode.minestom.collision;
 
 import fr.themode.minestom.entity.Entity;
+import fr.themode.minestom.utils.BlockPosition;
+import fr.themode.minestom.utils.Position;
 
 /**
  * See https://wiki.vg/Entity_metadata#Mobs_2
@@ -23,6 +25,31 @@ public class BoundingBox {
                 (getMinZ() <= boundingBox.getMaxZ() && getMaxZ() >= boundingBox.getMinZ());
     }
 
+    public boolean intersect(BlockPosition blockPosition) {
+        final float x = 1f;
+        final float y = 1;
+        final float z = 1f;
+        float minX = blockPosition.getX() - (x / 2) + 0.5f;
+        float maxX = blockPosition.getX() + (x / 2) + 0.5f;
+
+        float minY = blockPosition.getY();
+        float maxY = blockPosition.getY() + y;
+
+        float minZ = blockPosition.getZ() - (z / 2) + 0.5f;
+        float maxZ = blockPosition.getZ() + (z / 2) + 0.5f;
+
+        boolean checkX = getMinX() + x / 2 < maxX && getMaxX() - x / 2 > minX;
+        boolean checkY = getMinY() + y < maxY && getMaxY() + y > minY;
+        boolean checkZ = getMinZ() + z / 2 < maxZ && getMaxZ() - z / 2 > minZ;
+        return checkX && checkY && checkZ;
+    }
+
+    public boolean intersect(Position position) {
+        return (position.getX() >= getMinX() && position.getX() <= getMaxX()) &&
+                (position.getY() >= getMinY() && position.getY() <= getMaxY()) &&
+                (position.getZ() >= getMinZ() && position.getZ() <= getMaxZ());
+    }
+
     public BoundingBox expand(float x, float y, float z) {
         return new BoundingBox(entity, this.x + x, this.y + y, this.z + z);
     }
@@ -63,4 +90,8 @@ public class BoundingBox {
         return entity.getPosition().getZ() + (z / 2);
     }
 
+    @Override
+    public String toString() {
+        return "BoundingBox[" + x + ":" + y + ":" + z + "]";
+    }
 }

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

@@ -153,7 +153,7 @@ public abstract class Entity implements Viewable, DataContainer {
         player.viewableEntity.add(this);
         PlayerConnection playerConnection = player.getPlayerConnection();
         playerConnection.sendPacket(getVelocityPacket());
-        playerConnection.sendPacket(getPassengersPacket()); // TODO fix synchronization
+        playerConnection.sendPacket(getPassengersPacket());
     }
 
     @Override

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

@@ -94,9 +94,9 @@ public abstract class EntityCreature extends LivingEntity {
         spawnMobPacket.entityType = getEntityType();
         spawnMobPacket.position = getPosition();
         spawnMobPacket.headPitch = 0;
+        spawnMobPacket.metadata = getMetadataBuffer();
         playerConnection.sendPacket(entityPacket);
         playerConnection.sendPacket(spawnMobPacket);
-        playerConnection.sendPacket(getMetadataPacket());
     }
 
     @Override

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

@@ -0,0 +1,52 @@
+package fr.themode.minestom.entity;
+
+import fr.themode.minestom.net.packet.server.play.SpawnExperienceOrbPacket;
+import fr.themode.minestom.net.player.PlayerConnection;
+import fr.themode.minestom.utils.EntityUtils;
+
+public class ExperienceOrb extends Entity {
+
+    private short experienceCount;
+
+    public ExperienceOrb(short experienceCount) {
+        super(23);
+        setGravity(0.02f);
+        setBoundingBox(0.5f, 0.5f, 0.5f);
+        this.experienceCount = experienceCount;
+    }
+
+    @Override
+    public void update() {
+        // TODO slide toward nearest player
+    }
+
+    @Override
+    public void spawn() {
+
+    }
+
+    @Override
+    public boolean isOnGround() {
+        return EntityUtils.isOnGround(this);
+    }
+
+    @Override
+    public void addViewer(Player player) {
+        PlayerConnection playerConnection = player.getPlayerConnection();
+
+        SpawnExperienceOrbPacket experienceOrbPacket = new SpawnExperienceOrbPacket();
+        experienceOrbPacket.entityId = getEntityId();
+        experienceOrbPacket.position = getPosition();
+        experienceOrbPacket.expCount = experienceCount;
+        playerConnection.sendPacket(experienceOrbPacket);
+        super.addViewer(player); // Add player to viewers list and send velocity packet
+    }
+
+    public short getExperienceCount() {
+        return experienceCount;
+    }
+
+    public void setExperienceCount(short experienceCount) {
+        this.experienceCount = experienceCount;
+    }
+}

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

@@ -57,7 +57,7 @@ public abstract class LivingEntity extends Entity {
                                 collectItemPacket.collectorEntityId = getEntityId();
                                 collectItemPacket.pickupItemCount = item.getAmount();
                                 sendPacketToViewersAndSelf(collectItemPacket);
-                                entity.scheduleRemove(500);
+                                entity.remove();
                             });
                         }
                     }

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

@@ -3,8 +3,8 @@ package fr.themode.minestom.entity;
 import fr.themode.minestom.Main;
 import fr.themode.minestom.bossbar.BossBar;
 import fr.themode.minestom.chat.Chat;
+import fr.themode.minestom.collision.BoundingBox;
 import fr.themode.minestom.data.Data;
-import fr.themode.minestom.entity.demo.ChickenCreature;
 import fr.themode.minestom.entity.property.Attribute;
 import fr.themode.minestom.event.*;
 import fr.themode.minestom.instance.Chunk;
@@ -65,6 +65,8 @@ public class Player extends LivingEntity {
     protected Set<Entity> viewableEntity = new CopyOnWriteArraySet<>();
 
     private PlayerSettings settings;
+    private float exp;
+    private int level;
     private PlayerInventory inventory;
     private short heldSlot;
     private Inventory openInventory;
@@ -156,10 +158,10 @@ public class Player extends LivingEntity {
             setGameMode(GameMode.SURVIVAL);
             teleport(new Position(0, 66, 0));
 
-            ChickenCreature chickenCreature = new ChickenCreature();
+            /*ChickenCreature chickenCreature = new ChickenCreature();
             chickenCreature.refreshPosition(2, 65, 2);
             chickenCreature.setInstance(getInstance());
-            chickenCreature.addPassenger(this);
+            chickenCreature.addPassenger(this);*/
 
             /*for (int ix = 0; ix < 4; ix++)
                 for (int iz = 0; iz < 4; iz++) {
@@ -170,6 +172,10 @@ public class Player extends LivingEntity {
                     //itemEntity.remove();
                 }*/
 
+            ExperienceOrb experienceOrb = new ExperienceOrb((short) 500);
+            experienceOrb.refreshPosition(5, 66, 0);
+            experienceOrb.setInstance(getInstance());
+
             getInventory().addItemStack(new ItemStack(1, (byte) 100));
 
             TeamsPacket teamsPacket = new TeamsPacket();
@@ -186,6 +192,8 @@ public class Player extends LivingEntity {
 
             setAttribute(Attribute.MAX_HEALTH, 40);
             heal();
+
+            setExp(0.9f);
         });
     }
 
@@ -217,6 +225,28 @@ public class Player extends LivingEntity {
             }
         }
 
+        // Experience orb pickup
+        Chunk chunk = instance.getChunkAt(getPosition()); // TODO check surrounding chunks
+        Set<Entity> entities = instance.getChunkEntities(chunk);
+        BoundingBox livingBoundingBox = getBoundingBox().expand(1, 0.5f, 1);
+        for (Entity entity : entities) {
+            if (entity instanceof ExperienceOrb) {
+                ExperienceOrb experienceOrb = (ExperienceOrb) entity;
+                BoundingBox itemBoundingBox = experienceOrb.getBoundingBox();
+                if (livingBoundingBox.intersect(itemBoundingBox)) {
+                    synchronized (experienceOrb) {
+                        if (experienceOrb.shouldRemove() || experienceOrb.isRemoveScheduled())
+                            continue;
+                        PickupExperienceEvent pickupExperienceEvent = new PickupExperienceEvent(experienceOrb.getExperienceCount());
+                        callCancellableEvent(PickupExperienceEvent.class, pickupExperienceEvent, () -> {
+                            short experienceCount = pickupExperienceEvent.getExperienceCount(); // TODO give to player
+                            entity.remove();
+                        });
+                    }
+                }
+            }
+        }
+
 
         // Multiplayer sync
         Position position = getPosition();
@@ -445,6 +475,25 @@ public class Player extends LivingEntity {
         playerConnection.sendPacket(updateHealthPacket);
     }
 
+    public void setExp(float exp) {
+        if (exp < 0 || exp > 1)
+            throw new IllegalArgumentException("Exp should be between 0 and 1");
+        this.exp = exp;
+        sendExperienceUpdatePacket();
+    }
+
+    public void setLevel(int level) {
+        this.level = level;
+        sendExperienceUpdatePacket();
+    }
+
+    protected void sendExperienceUpdatePacket() {
+        SetExperiencePacket setExperiencePacket = new SetExperiencePacket();
+        setExperiencePacket.percentage = exp;
+        setExperiencePacket.level = level;
+        playerConnection.sendPacket(setExperiencePacket);
+    }
+
     protected void onChunkChange(Chunk lastChunk, Chunk newChunk) {
         float dx = newChunk.getChunkX() - lastChunk.getChunkX();
         float dz = newChunk.getChunkZ() - lastChunk.getChunkZ();

src/main/java/fr/themode/minestom/event/PickupExperienceEvent.java

@@ -0,0 +1,18 @@
+package fr.themode.minestom.event;
+
+public class PickupExperienceEvent extends CancellableEvent {
+
+    private short experienceCount;
+
+    public PickupExperienceEvent(short experienceCount) {
+        this.experienceCount = experienceCount;
+    }
+
+    public short getExperienceCount() {
+        return experienceCount;
+    }
+
+    public void setExperienceCount(short experienceCount) {
+        this.experienceCount = experienceCount;
+    }
+}

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

@@ -2,10 +2,7 @@ package fr.themode.minestom.instance;
 
 import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.Main;
-import fr.themode.minestom.entity.Entity;
+import fr.themode.minestom.entity.*;
-import fr.themode.minestom.entity.EntityCreature;
-import fr.themode.minestom.entity.ObjectEntity;
-import fr.themode.minestom.entity.Player;
 import fr.themode.minestom.utils.BlockPosition;
 import fr.themode.minestom.utils.ChunkUtils;
 import fr.themode.minestom.utils.Position;
@@ -20,9 +17,10 @@ public abstract class Instance implements BlockModifier {
 
     protected static final ChunkLoaderIO CHUNK_LOADER_IO = new ChunkLoaderIO();
     // Entities present in this instance
-    protected Set<ObjectEntity> objectEntities = new CopyOnWriteArraySet<>();
-    protected Set<EntityCreature> creatures = new CopyOnWriteArraySet<>();
     protected Set<Player> players = new CopyOnWriteArraySet<>();
+    protected Set<EntityCreature> creatures = new CopyOnWriteArraySet<>();
+    protected Set<ObjectEntity> objectEntities = new CopyOnWriteArraySet<>();
+    protected Set<ExperienceOrb> experienceOrbs = new CopyOnWriteArraySet<>();
     // Entities per chunk
     protected Map<Long, Set<Entity>> chunkEntities = new ConcurrentHashMap<>();
     private UUID uniqueId;
@@ -79,16 +77,20 @@ public abstract class Instance implements BlockModifier {
     }
     //
 
-    public Set<ObjectEntity> getObjectEntities() {
+    public Set<Player> getPlayers() {
-        return Collections.unmodifiableSet(objectEntities);
+        return Collections.unmodifiableSet(players);
     }
 
     public Set<EntityCreature> getCreatures() {
         return Collections.unmodifiableSet(creatures);
     }
 
-    public Set<Player> getPlayers() {
+    public Set<ObjectEntity> getObjectEntities() {
-        return Collections.unmodifiableSet(players);
+        return Collections.unmodifiableSet(objectEntities);
+    }
+
+    public Set<ExperienceOrb> getExperienceOrbs() {
+        return Collections.unmodifiableSet(experienceOrbs);
     }
 
     public Set<Entity> getChunkEntities(Chunk chunk) {
@@ -197,6 +199,8 @@ public abstract class Instance implements BlockModifier {
             this.creatures.add((EntityCreature) entity);
         } else if (entity instanceof ObjectEntity) {
             this.objectEntities.add((ObjectEntity) entity);
+        } else if (entity instanceof ExperienceOrb) {
+            this.experienceOrbs.add((ExperienceOrb) entity);
         }
     }
 
@@ -215,6 +219,8 @@ public abstract class Instance implements BlockModifier {
             this.creatures.remove(entity);
         } else if (entity instanceof ObjectEntity) {
             this.objectEntities.remove(entity);
+        } else if (entity instanceof ExperienceOrb) {
+            this.experienceOrbs.remove((ExperienceOrb) entity);
         }
     }
 

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

@@ -3,7 +3,7 @@ package fr.themode.minestom.instance;
 import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.Player;
 import fr.themode.minestom.event.PlayerBlockBreakEvent;
-import fr.themode.minestom.net.PacketWriter;
+import fr.themode.minestom.net.PacketWriterUtils;
 import fr.themode.minestom.net.packet.server.play.ParticlePacket;
 import fr.themode.minestom.utils.BlockPosition;
 import fr.themode.minestom.utils.ChunkUtils;
@@ -38,7 +38,7 @@ public class InstanceContainer extends Instance {
         Chunk chunk = getChunkAt(x, z);
         synchronized (chunk) {
             chunk.setBlock((byte) (x % 16), (byte) y, (byte) (z % 16), blockId);
-            PacketWriter.writeCallbackPacket(chunk.getFreshPartialDataPacket(), buffer -> {
+            PacketWriterUtils.writeCallbackPacket(chunk.getFreshPartialDataPacket(), buffer -> {
                 chunk.setFullDataPacket(buffer);
                 sendChunkUpdate(chunk);
             });
@@ -50,7 +50,7 @@ public class InstanceContainer extends Instance {
         Chunk chunk = getChunkAt(x, z);
         synchronized (chunk) {
             chunk.setCustomBlock((byte) (x % 16), (byte) y, (byte) (z % 16), blockId);
-            PacketWriter.writeCallbackPacket(chunk.getFreshPartialDataPacket(), buffer -> {
+            PacketWriterUtils.writeCallbackPacket(chunk.getFreshPartialDataPacket(), buffer -> {
                 chunk.setFullDataPacket(buffer);
                 sendChunkUpdate(chunk);
             });
@@ -216,7 +216,7 @@ public class InstanceContainer extends Instance {
         }else{
             sendChunkUpdate(player, chunk);
         }*/
-        PacketWriter.writeCallbackPacket(chunk.getFreshFullDataPacket(), buffer -> {
+        PacketWriterUtils.writeCallbackPacket(chunk.getFreshFullDataPacket(), buffer -> {
             chunk.setFullDataPacket(buffer);
             sendChunkUpdate(player, chunk);
         });

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

@@ -31,23 +31,26 @@ public class BlockPlacementListener {
         int offsetZ = blockFace == ClientPlayerDiggingPacket.BlockFace.NORTH ? -1 : blockFace == ClientPlayerDiggingPacket.BlockFace.SOUTH ? 1 : 0;
 
         blockPosition.add(offsetX, offsetY, offsetZ);
-        PlayerBlockPlaceEvent playerBlockPlaceEvent = new PlayerBlockPlaceEvent((short) 10, blockPosition, packet.hand);
+        boolean intersectPlayer = player.getBoundingBox().intersect(blockPosition);
-        player.callEvent(PlayerBlockPlaceEvent.class, playerBlockPlaceEvent);
+        if (!intersectPlayer) {
-        if (!playerBlockPlaceEvent.isCancelled()) {
+            PlayerBlockPlaceEvent playerBlockPlaceEvent = new PlayerBlockPlaceEvent((short) 10, blockPosition, packet.hand);
-            instance.setBlock(blockPosition, "custom_block"); // TODO set useItem's block instead
+            player.callEvent(PlayerBlockPlaceEvent.class, playerBlockPlaceEvent);
-            if (playerBlockPlaceEvent.doesConsumeBlock()) {
+            if (!playerBlockPlaceEvent.isCancelled()) {
-                usedItem.setAmount((byte) (usedItem.getAmount() - 1));
+                instance.setBlock(blockPosition, "custom_block"); // TODO set useItem's block instead
-                if (usedItem.getAmount() <= 0)
+                if (playerBlockPlaceEvent.doesConsumeBlock()) {
-                    usedItem = ItemStack.AIR_ITEM;
+                    usedItem.setAmount((byte) (usedItem.getAmount() - 1));
-                if (hand == Player.Hand.OFF) {
+                    if (usedItem.getAmount() <= 0)
-                    playerInventory.setItemInOffHand(usedItem);
+                        usedItem = ItemStack.AIR_ITEM;
-                } else { // Main
+                    if (hand == Player.Hand.OFF) {
-                    playerInventory.setItemInMainHand(usedItem);
+                        playerInventory.setItemInOffHand(usedItem);
+                    } else { // Main
+                        playerInventory.setItemInMainHand(usedItem);
+                    }
                 }
+            } else {
+                Chunk chunk = instance.getChunkAt(blockPosition);
+                instance.sendChunkUpdate(player, chunk);
             }
-        } else {
-            Chunk chunk = instance.getChunkAt(blockPosition);
-            instance.sendChunkUpdate(player, chunk);
         }
         player.getInventory().refreshSlot(player.getHeldSlot());
     }

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

@@ -5,6 +5,7 @@ import fr.adamaq01.ozao.net.packet.Packet;
 import fr.adamaq01.ozao.net.server.Connection;
 import fr.themode.minestom.Main;
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
 import fr.themode.minestom.net.packet.client.handler.ClientLoginPacketsHandler;
@@ -52,11 +53,13 @@ public class PacketProcessor {
             //System.out.println("RECEIVED ID: 0x" + Integer.toHexString(id) + " State: " + connectionState);
         }
 
+        PacketReader packetReader = new PacketReader(buffer);
+
         if (connectionState == ConnectionState.UNKNOWN) {
             // Should be handshake packet
             if (id == 0) {
                 HandshakePacket handshakePacket = new HandshakePacket();
-                handshakePacket.read(buffer);
+                handshakePacket.read(packetReader);
                 handshakePacket.process(playerConnection, connectionManager);
             }
             return;
@@ -66,17 +69,17 @@ public class PacketProcessor {
             case PLAY:
                 Player player = connectionManager.getPlayer(playerConnection);
                 ClientPlayPacket playPacket = (ClientPlayPacket) playPacketsHandler.getPacketInstance(id);
-                playPacket.read(buffer);
+                playPacket.read(packetReader);
                 player.addPacketToQueue(playPacket); // Processed during player tick update
                 break;
             case LOGIN:
                 ClientPreplayPacket loginPacket = (ClientPreplayPacket) loginPacketsHandler.getPacketInstance(id);
-                loginPacket.read(buffer);
+                loginPacket.read(packetReader);
                 loginPacket.process(playerConnection, connectionManager);
                 break;
             case STATUS:
                 ClientPreplayPacket statusPacket = (ClientPreplayPacket) statusPacketsHandler.getPacketInstance(id);
-                statusPacket.read(buffer);
+                statusPacket.read(packetReader);
                 statusPacket.process(playerConnection, connectionManager);
                 break;
             case UNKNOWN:

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

@@ -10,7 +10,7 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.function.Consumer;
 
-public class PacketWriter {
+public class PacketWriterUtils {
 
     private static volatile ExecutorService batchesPool = Executors.newFixedThreadPool(Main.THREAD_COUNT_PACKET_WRITER);
 

src/main/java/fr/themode/minestom/net/packet/PacketReader.java

@@ -0,0 +1,55 @@
+package fr.themode.minestom.net.packet;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.utils.BlockPosition;
+import fr.themode.minestom.utils.Utils;
+
+public class PacketReader {
+
+    private Buffer buffer;
+
+    public PacketReader(Buffer buffer) {
+        this.buffer = buffer;
+    }
+
+    public int readVarInt() {
+        return Utils.readVarInt(buffer);
+    }
+
+    public boolean readBoolean() {
+        return buffer.getBoolean();
+    }
+
+    public byte readByte() {
+        return buffer.getByte();
+    }
+
+    public short readShort() {
+        return buffer.getShort();
+    }
+
+    public long readLong() {
+        return buffer.getLong();
+    }
+
+    public float readFloat() {
+        return buffer.getFloat();
+    }
+
+    public double readDouble() {
+        return buffer.getDouble();
+    }
+
+    public String readSizedString() {
+        return Utils.readString(buffer);
+    }
+
+    public byte[] getRemainingBytes() {
+        return buffer.getAllBytes();
+    }
+
+    public BlockPosition readBlockPosition() {
+        return Utils.readPosition(buffer);
+    }
+
+}

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

@@ -0,0 +1,101 @@
+package fr.themode.minestom.net.packet;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.item.ItemStack;
+import fr.themode.minestom.utils.BlockPosition;
+import fr.themode.minestom.utils.Utils;
+
+import java.util.UUID;
+
+public class PacketWriter {
+
+    private Buffer buffer;
+
+    public PacketWriter(Buffer buffer) {
+        this.buffer = buffer;
+    }
+
+    public void writeBoolean(boolean b) {
+        buffer.putBoolean(b);
+    }
+
+    public void writeByte(byte b) {
+        buffer.putByte(b);
+    }
+
+    public void writeShort(short s) {
+        buffer.putShort(s);
+    }
+
+    public void writeInt(int i) {
+        buffer.putInt(i);
+    }
+
+    public void writeLong(long l) {
+        buffer.putLong(l);
+    }
+
+    public void writeFloat(float f) {
+        buffer.putFloat(f);
+    }
+
+    public void writeDouble(double d) {
+        buffer.putDouble(d);
+    }
+
+    public void writeVarInt(int i) {
+        Utils.writeVarInt(buffer, i);
+    }
+
+    public void writeSizedString(String string) {
+        Utils.writeString(buffer, string);
+    }
+
+    public void writeVarIntArray(int[] array) {
+        if (array == null) {
+            writeVarInt(0);
+            return;
+        }
+        writeVarInt(array.length);
+        for (int element : array) {
+            writeVarInt(element);
+        }
+    }
+
+    public void writeBytes(byte[] bytes) {
+        buffer.putBytes(bytes);
+    }
+
+    public void writeStringArray(String[] array) {
+        if (array == null) {
+            writeVarInt(0);
+            return;
+        }
+        writeVarInt(array.length);
+        for (String element : array) {
+            writeSizedString(element);
+        }
+    }
+
+    public void writeBuffer(Buffer buffer) {
+        this.buffer.putBuffer(buffer);
+    }
+
+    public void writeUuid(UUID uuid) {
+        writeLong(uuid.getMostSignificantBits());
+        writeLong(uuid.getLeastSignificantBits());
+    }
+
+    public void writeBlockPosition(BlockPosition blockPosition) {
+        Utils.writePosition(buffer, blockPosition);
+    }
+
+    public void writeBlockPosition(int x, int y, int z) {
+        Utils.writePosition(buffer, x, y, z);
+    }
+
+    public void writeItemStack(ItemStack itemStack) {
+        Utils.writeItemStack(buffer, itemStack);
+    }
+
+}

src/main/java/fr/themode/minestom/net/packet/client/ClientPacket.java

@@ -1,9 +1,9 @@
 package fr.themode.minestom.net.packet.client;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 
 public interface ClientPacket {
 
-    void read(Buffer buffer);
+    void read(PacketReader reader);
 
 }

src/main/java/fr/themode/minestom/net/packet/client/handshake/HandshakePacket.java

@@ -1,24 +1,21 @@
 package fr.themode.minestom.net.packet.client.handshake;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.net.ConnectionManager;
 import fr.themode.minestom.net.ConnectionState;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
 import fr.themode.minestom.net.player.PlayerConnection;
 
-import static fr.themode.minestom.utils.Utils.readString;
-import static fr.themode.minestom.utils.Utils.readVarInt;
-
 public class HandshakePacket implements ClientPreplayPacket {
 
     private int nextState;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        int protocolVersion = readVarInt(buffer);
+        int protocolVersion = reader.readVarInt();
-        String serverAddress = readString(buffer);
+        String serverAddress = reader.readSizedString();
-        short serverPort = buffer.getShort();
+        short serverPort = reader.readShort();
-        this.nextState = readVarInt(buffer);
+        this.nextState = reader.readVarInt();
     }
 
     @Override

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

@@ -1,18 +1,17 @@
 package fr.themode.minestom.net.packet.client.login;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.Main;
 import fr.themode.minestom.entity.GameMode;
 import fr.themode.minestom.entity.Player;
 import fr.themode.minestom.net.ConnectionManager;
 import fr.themode.minestom.net.ConnectionState;
+import fr.themode.minestom.net.packet.PacketReader;
 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.PlayerInfoPacket;
 import fr.themode.minestom.net.packet.server.play.SpawnPositionPacket;
 import fr.themode.minestom.net.player.PlayerConnection;
-import fr.themode.minestom.utils.Utils;
 import fr.themode.minestom.world.Dimension;
 import fr.themode.minestom.world.LevelType;
 
@@ -107,7 +106,7 @@ public class LoginStartPacket implements ClientPreplayPacket {
     }
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.username = Utils.readString(buffer);
+        this.username = reader.readSizedString();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientAnimationPacket.java

@@ -1,16 +1,15 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientAnimationPacket extends ClientPlayPacket {
 
     public Player.Hand hand;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.hand = Player.Hand.values()[Utils.readVarInt(buffer)];
+        this.hand = Player.Hand.values()[reader.readVarInt()];
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientChatMessagePacket.java

@@ -1,15 +1,14 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientChatMessagePacket extends ClientPlayPacket {
 
     public String message;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.message = Utils.readString(buffer);
+        this.message = reader.readSizedString();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientClickWindowPacket.java

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientClickWindowPacket extends ClientPlayPacket {
 
@@ -14,12 +13,12 @@ public class ClientClickWindowPacket extends ClientPlayPacket {
     // TODO clicked item
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.windowId = buffer.getByte();
+        this.windowId = reader.readByte();
-        this.slot = buffer.getShort();
+        this.slot = reader.readShort();
-        this.button = buffer.getByte();
+        this.button = reader.readByte();
-        this.actionNumber = buffer.getShort();
+        this.actionNumber = reader.readShort();
-        this.mode = Utils.readVarInt(buffer);
+        this.mode = reader.readVarInt();
         // TODO read clicked item
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientCloseWindow.java

@@ -1,15 +1,14 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientCloseWindow extends ClientPlayPacket {
 
     public int windowId;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.windowId = Utils.readVarInt(buffer);
+        this.windowId = reader.readVarInt();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientConfirmTransactionPacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientConfirmTransactionPacket extends ClientPlayPacket {
@@ -10,7 +10,7 @@ public class ClientConfirmTransactionPacket extends ClientPlayPacket {
     public boolean accepted;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
         // TODO
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientEntityActionPacket.java

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientEntityActionPacket extends ClientPlayPacket {
 
@@ -11,10 +10,10 @@ public class ClientEntityActionPacket extends ClientPlayPacket {
     public int horseJumpBoost;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.playerId = Utils.readVarInt(buffer);
+        this.playerId = reader.readVarInt();
-        this.action = Action.values()[Utils.readVarInt(buffer)];
+        this.action = Action.values()[reader.readVarInt()];
-        this.horseJumpBoost = Utils.readVarInt(buffer);
+        this.horseJumpBoost = reader.readVarInt();
     }
 
     public enum Action {

src/main/java/fr/themode/minestom/net/packet/client/play/ClientHeldItemChangePacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientHeldItemChangePacket extends ClientPlayPacket {
@@ -8,7 +8,7 @@ public class ClientHeldItemChangePacket extends ClientPlayPacket {
     public short slot;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.slot = buffer.getShort();
+        this.slot = reader.readShort();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientKeepAlivePacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientKeepAlivePacket extends ClientPlayPacket {
@@ -8,7 +8,7 @@ public class ClientKeepAlivePacket extends ClientPlayPacket {
     public long id;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.id = buffer.getLong();
+        this.id = reader.readLong();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPlayerAbilitiesPacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientPlayerAbilitiesPacket extends ClientPlayPacket {
@@ -10,9 +10,9 @@ public class ClientPlayerAbilitiesPacket extends ClientPlayPacket {
     public float walkingSpeed;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.flags = buffer.getByte();
+        this.flags = reader.readByte();
-        this.flyingSpeed = buffer.getFloat();
+        this.flyingSpeed = reader.readFloat();
-        this.walkingSpeed = buffer.getFloat();
+        this.walkingSpeed = reader.readFloat();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPlayerBlockPlacementPacket.java

@@ -1,10 +1,9 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 import fr.themode.minestom.utils.BlockPosition;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientPlayerBlockPlacementPacket extends ClientPlayPacket {
 
@@ -15,14 +14,14 @@ public class ClientPlayerBlockPlacementPacket extends ClientPlayPacket {
     public boolean insideBlock;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.hand = Player.Hand.values()[Utils.readVarInt(buffer)];
+        this.hand = Player.Hand.values()[reader.readVarInt()];
-        this.blockPosition = Utils.readPosition(buffer);
+        this.blockPosition = reader.readBlockPosition();
-        this.blockFace = ClientPlayerDiggingPacket.BlockFace.values()[Utils.readVarInt(buffer)];
+        this.blockFace = ClientPlayerDiggingPacket.BlockFace.values()[reader.readVarInt()];
-        this.cursorPositionX = buffer.getFloat();
+        this.cursorPositionX = reader.readFloat();
-        this.cursorPositionY = buffer.getFloat();
+        this.cursorPositionY = reader.readFloat();
-        this.cursorPositionZ = buffer.getFloat();
+        this.cursorPositionZ = reader.readFloat();
-        this.insideBlock = buffer.getBoolean();
+        this.insideBlock = reader.readBoolean();
     }
 
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPlayerDiggingPacket.java

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 import fr.themode.minestom.utils.BlockPosition;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientPlayerDiggingPacket extends ClientPlayPacket {
 
@@ -12,10 +11,10 @@ public class ClientPlayerDiggingPacket extends ClientPlayPacket {
     public BlockFace blockFace;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.status = Status.values()[Utils.readVarInt(buffer)];
+        this.status = Status.values()[reader.readVarInt()];
-        this.blockPosition = Utils.readPosition(buffer);
+        this.blockPosition = reader.readBlockPosition();
-        this.blockFace = BlockFace.values()[Utils.readVarInt(buffer)];
+        this.blockFace = BlockFace.values()[reader.readVarInt()];
     }
 
     public enum Status {

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPlayerLookPacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientPlayerLookPacket extends ClientPlayPacket {
@@ -9,9 +9,9 @@ public class ClientPlayerLookPacket extends ClientPlayPacket {
     public boolean onGround;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.yaw = buffer.getFloat();
+        this.yaw = reader.readFloat();
-        this.pitch = buffer.getFloat();
+        this.pitch = reader.readFloat();
-        this.onGround = buffer.getBoolean();
+        this.onGround = reader.readBoolean();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPlayerPacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientPlayerPacket extends ClientPlayPacket {
@@ -8,7 +8,7 @@ public class ClientPlayerPacket extends ClientPlayPacket {
     public boolean onGround;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.onGround = buffer.getBoolean();
+        this.onGround = reader.readBoolean();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPlayerPositionAndLookPacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientPlayerPositionAndLookPacket extends ClientPlayPacket {
@@ -10,12 +10,12 @@ public class ClientPlayerPositionAndLookPacket extends ClientPlayPacket {
     public boolean onGround;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.x = buffer.getDouble();
+        this.x = reader.readDouble();
-        this.y = buffer.getDouble();
+        this.y = reader.readDouble();
-        this.z = buffer.getDouble();
+        this.z = reader.readDouble();
-        this.yaw = buffer.getFloat();
+        this.yaw = reader.readFloat();
-        this.pitch = buffer.getFloat();
+        this.pitch = reader.readFloat();
-        this.onGround = buffer.getBoolean();
+        this.onGround = reader.readBoolean();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPlayerPositionPacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientPlayerPositionPacket extends ClientPlayPacket {
@@ -9,10 +9,10 @@ public class ClientPlayerPositionPacket extends ClientPlayPacket {
     public boolean onGround;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.x = buffer.getDouble();
+        this.x = reader.readDouble();
-        this.y = buffer.getDouble();
+        this.y = reader.readDouble();
-        this.z = buffer.getDouble();
+        this.z = reader.readDouble();
-        this.onGround = buffer.getBoolean();
+        this.onGround = reader.readBoolean();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientPluginMessagePacket.java

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientPluginMessagePacket extends ClientPlayPacket {
 
@@ -10,8 +9,8 @@ public class ClientPluginMessagePacket extends ClientPlayPacket {
     private byte[] data;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.identifier = Utils.readString(buffer);
+        this.identifier = reader.readSizedString();
-        this.data = buffer.getAllBytes();
+        this.data = reader.getRemainingBytes();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientSettingsPacket.java

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientSettingsPacket extends ClientPlayPacket {
 
@@ -15,12 +14,12 @@ public class ClientSettingsPacket extends ClientPlayPacket {
     public Player.MainHand mainHand;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.locale = Utils.readString(buffer);
+        this.locale = reader.readSizedString();
-        this.viewDistance = buffer.getByte();
+        this.viewDistance = reader.readByte();
-        this.chatMode = Player.ChatMode.values()[Utils.readVarInt(buffer)];
+        this.chatMode = Player.ChatMode.values()[reader.readVarInt()];
-        this.chatColors = buffer.getBoolean();
+        this.chatColors = reader.readBoolean();
-        this.displayedSkinParts = buffer.getByte();
+        this.displayedSkinParts = reader.readByte();
-        this.mainHand = Player.MainHand.values()[Utils.readVarInt(buffer)];
+        this.mainHand = Player.MainHand.values()[reader.readVarInt()];
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientStatusPacket.java

@@ -1,16 +1,15 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientStatusPacket extends ClientPlayPacket {
 
     public Action action;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.action = Action.values()[Utils.readVarInt(buffer)];
+        this.action = Action.values()[reader.readVarInt()];
     }
 
     public enum Action {

src/main/java/fr/themode/minestom/net/packet/client/play/ClientSteerVehiclePacket.java

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
 
 public class ClientSteerVehiclePacket extends ClientPlayPacket {
@@ -10,9 +10,9 @@ public class ClientSteerVehiclePacket extends ClientPlayPacket {
     public byte flags;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.sideways = buffer.getFloat();
+        this.sideways = reader.readFloat();
-        this.forward = buffer.getFloat();
+        this.forward = reader.readFloat();
-        this.flags = buffer.getByte();
+        this.flags = reader.readByte();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientTeleportConfirmPacket.java

@@ -1,15 +1,14 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientTeleportConfirmPacket extends ClientPlayPacket {
 
     public int teleportId;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.teleportId = Utils.readVarInt(buffer);
+        this.teleportId = reader.readVarInt();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/play/ClientUseEntityPacket.java

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientUseEntityPacket extends ClientPlayPacket {
 
@@ -15,16 +14,16 @@ public class ClientUseEntityPacket extends ClientPlayPacket {
     public Player.Hand hand;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.targetId = Utils.readVarInt(buffer);
+        this.targetId = reader.readVarInt();
-        this.type = Type.values()[Utils.readVarInt(buffer)];
+        this.type = Type.values()[reader.readVarInt()];
         if (this.type == Type.INTERACT_AT) {
-            this.x = buffer.getFloat();
+            this.x = reader.readFloat();
-            this.y = buffer.getFloat();
+            this.y = reader.readFloat();
-            this.z = buffer.getFloat();
+            this.z = reader.readFloat();
         }
         if (type == Type.INTERACT || type == Type.INTERACT_AT)
-            this.hand = Player.Hand.values()[Utils.readVarInt(buffer)];
+            this.hand = Player.Hand.values()[reader.readVarInt()];
     }
 
     public enum Type {

src/main/java/fr/themode/minestom/net/packet/client/play/ClientUseItemPacket.java

@@ -1,16 +1,15 @@
 package fr.themode.minestom.net.packet.client.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPlayPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ClientUseItemPacket extends ClientPlayPacket {
 
     public Player.Hand hand;
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.hand = Player.Hand.values()[Utils.readVarInt(buffer)];
+        this.hand = Player.Hand.values()[reader.readVarInt()];
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/status/PingPacket.java

@@ -1,7 +1,7 @@
 package fr.themode.minestom.net.packet.client.status;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
 import fr.themode.minestom.net.packet.server.status.PongPacket;
 import fr.themode.minestom.net.player.PlayerConnection;
@@ -18,7 +18,7 @@ public class PingPacket implements ClientPreplayPacket {
     }
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
-        this.number = buffer.getLong();
+        this.number = reader.readLong();
     }
 }

src/main/java/fr/themode/minestom/net/packet/client/status/StatusRequestPacket.java

@@ -1,7 +1,7 @@
 package fr.themode.minestom.net.packet.client.status;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.packet.PacketReader;
 import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
 import fr.themode.minestom.net.packet.server.handshake.ResponsePacket;
 import fr.themode.minestom.net.player.PlayerConnection;
@@ -15,7 +15,7 @@ public class StatusRequestPacket implements ClientPreplayPacket {
     }
 
     @Override
-    public void read(Buffer buffer) {
+    public void read(PacketReader reader) {
         // Empty
     }
 }

src/main/java/fr/themode/minestom/net/packet/server/ServerPacket.java

@@ -1,10 +1,10 @@
 package fr.themode.minestom.net.packet.server;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 
 public interface ServerPacket {
 
-    void write(Buffer buffer);
+    void write(PacketWriter writer);
 
     int getId();
 

src/main/java/fr/themode/minestom/net/packet/server/handshake/ResponsePacket.java

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.handshake;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ResponsePacket implements ServerPacket {
 
@@ -28,8 +27,8 @@ public class ResponsePacket implements ServerPacket {
             "}";
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeString(buffer, JSON_EXAMPLE);
+        writer.writeSizedString(JSON_EXAMPLE);
     }
 
     @Override

src/main/java/fr/themode/minestom/net/packet/server/login/JoinGamePacket.java

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.login;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.GameMode;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 import fr.themode.minestom.world.Dimension;
 import fr.themode.minestom.world.LevelType;
 
@@ -18,18 +17,18 @@ public class JoinGamePacket implements ServerPacket {
     public boolean reducedDebugInfo = false;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
         int gameModeId = gameMode.getId();
         if (gameMode.isHardcore())
             gameModeId |= 8;
 
-        buffer.putInt(entityId);
+        writer.writeInt(entityId);
-        buffer.putByte((byte) gameModeId);
+        writer.writeByte((byte) gameModeId);
-        buffer.putInt(dimension.getId());
+        writer.writeInt(dimension.getId());
-        buffer.putByte(maxPlayers);
+        writer.writeByte(maxPlayers);
-        Utils.writeString(buffer, levelType.getType());
+        writer.writeSizedString(levelType.getType());
-        Utils.writeVarInt(buffer, viewDistance);
+        writer.writeVarInt(viewDistance);
-        buffer.putBoolean(reducedDebugInfo);
+        writer.writeBoolean(reducedDebugInfo);
     }
 
     @Override

src/main/java/fr/themode/minestom/net/packet/server/login/LoginSuccessPacket.java

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.login;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 import java.util.UUID;
 
@@ -22,9 +21,9 @@ public class LoginSuccessPacket implements ServerPacket {
     }
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeString(buffer, uuid.toString()); // TODO mojang auth
+        writer.writeSizedString(uuid.toString()); // TODO mojang auth
-        Utils.writeString(buffer, username);
+        writer.writeSizedString(username);
     }
 
     @Override

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

@@ -1,10 +1,9 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.client.play.ClientPlayerDiggingPacket;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.BlockPosition;
-import fr.themode.minestom.utils.Utils;
 
 public class AcknowledgePlayerDiggingPacket implements ServerPacket {
 
@@ -14,11 +13,11 @@ public class AcknowledgePlayerDiggingPacket implements ServerPacket {
     public boolean successful;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writePosition(buffer, blockPosition);
+        writer.writeBlockPosition(blockPosition);
-        Utils.writeVarInt(buffer, blockStateId);
+        writer.writeVarInt(blockStateId);
-        Utils.writeVarInt(buffer, status.ordinal());
+        writer.writeVarInt(status.ordinal());
-        buffer.putBoolean(successful);
+        writer.writeBoolean(successful);
     }
 
     @Override

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

@@ -1,10 +1,9 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.chat.Chat;
 import fr.themode.minestom.item.ItemStack;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class AdvancementsPacket implements ServerPacket {
 
@@ -14,22 +13,19 @@ public class AdvancementsPacket implements ServerPacket {
     public ProgressMapping[] progressMappings;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putBoolean(resetAdvancements);
+        writer.writeBoolean(resetAdvancements);
 
-        Utils.writeVarInt(buffer, advancementMappings.length);
+        writer.writeVarInt(advancementMappings.length);
         for (AdvancementMapping advancementMapping : advancementMappings) {
-            advancementMapping.write(buffer);
+            advancementMapping.write(writer);
         }
 
-        Utils.writeVarInt(buffer, identifiersToRemove.length);
+        writer.writeStringArray(identifiersToRemove);
-        for (String identifierToRemove : identifiersToRemove) {
-            Utils.writeString(buffer, identifierToRemove);
-        }
 
-        Utils.writeVarInt(buffer, progressMappings.length);
+        writer.writeVarInt(progressMappings.length);
         for (ProgressMapping progressMapping : progressMappings) {
-            progressMapping.write(buffer);
+            progressMapping.write(writer);
         }
     }
 
@@ -47,9 +43,9 @@ public class AdvancementsPacket implements ServerPacket {
         public String key;
         public Advancement value;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeString(buffer, key);
+            writer.writeSizedString(key);
-            value.write(buffer);
+            value.write(writer);
         }
 
     }
@@ -63,25 +59,23 @@ public class AdvancementsPacket implements ServerPacket {
         public String[] criterions;
         public Requirement[] requirements;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            buffer.putBoolean(hasParent);
+            writer.writeBoolean(hasParent);
             if (identifier != null) {
-                Utils.writeString(buffer, identifier);
+                writer.writeSizedString(identifier);
             }
 
-            buffer.putBoolean(hasDisplay);
+            writer.writeBoolean(hasDisplay);
             if (hasDisplay) {
-                displayData.write(buffer);
+                displayData.write(writer);
             }
 
-            Utils.writeVarInt(buffer, criterions.length);
+            writer.writeStringArray(criterions);
-            for (String criterion : criterions) {
-                Utils.writeString(buffer, criterion);
-            }
 
-            Utils.writeVarInt(buffer, requirements.length);
+
+            writer.writeVarInt(requirements.length);
             for (Requirement requirement : requirements) {
-                requirement.write(buffer);
+                requirement.write(writer);
             }
         }
     }
@@ -96,17 +90,17 @@ public class AdvancementsPacket implements ServerPacket {
         public float x;
         public float y;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeString(buffer, Chat.rawText(title));
+            writer.writeSizedString(Chat.rawText(title));
-            Utils.writeString(buffer, Chat.rawText(description));
+            writer.writeSizedString(Chat.rawText(description));
-            Utils.writeItemStack(buffer, icon);
+            writer.writeItemStack(icon);
-            Utils.writeVarInt(buffer, frameType.ordinal());
+            writer.writeVarInt(frameType.ordinal());
-            buffer.putInt(flags);
+            writer.writeInt(flags);
             if ((flags & 0x1) != 0) {
-                Utils.writeString(buffer, backgroundTexture);
+                writer.writeSizedString(backgroundTexture);
             }
-            buffer.putFloat(x);
+            writer.writeFloat(x);
-            buffer.putFloat(y);
+            writer.writeFloat(y);
         }
 
     }
@@ -115,10 +109,10 @@ public class AdvancementsPacket implements ServerPacket {
 
         public String[] requirements;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeVarInt(buffer, requirements.length);
+            writer.writeVarInt(requirements.length);
             for (String requirement : requirements) {
-                Utils.writeString(buffer, requirement);
+                writer.writeSizedString(requirement);
             }
         }
     }
@@ -127,19 +121,19 @@ public class AdvancementsPacket implements ServerPacket {
         public String key;
         public AdvancementProgress value;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeString(buffer, key);
+            writer.writeSizedString(key);
-            value.write(buffer);
+            value.write(writer);
         }
     }
 
     public static class AdvancementProgress {
         public Criteria[] criteria;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeVarInt(buffer, criteria.length);
+            writer.writeVarInt(criteria.length);
             for (Criteria criterion : criteria) {
-                criterion.write(buffer);
+                criterion.write(writer);
             }
         }
     }
@@ -148,9 +142,9 @@ public class AdvancementsPacket implements ServerPacket {
         public String criterionIdentifier;
         public CriterionProgress criterionProgress;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeString(buffer, criterionIdentifier);
+            writer.writeSizedString(criterionIdentifier);
-            criterionProgress.write(buffer);
+            criterionProgress.write(writer);
         }
     }
 
@@ -158,10 +152,10 @@ public class AdvancementsPacket implements ServerPacket {
         public boolean achieved;
         public long dateOfAchieving;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            buffer.putBoolean(achieved);
+            writer.writeBoolean(achieved);
             if (dateOfAchieving != 0)
-                buffer.putLong(dateOfAchieving);
+                writer.writeLong(dateOfAchieving);
         }
 
     }

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class AnimationPacket implements ServerPacket {
 
@@ -10,9 +9,9 @@ public class AnimationPacket implements ServerPacket {
     public Animation animation;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putByte((byte) animation.ordinal());
+        writer.writeByte((byte) animation.ordinal());
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.BlockPosition;
-import fr.themode.minestom.utils.Utils;
 
 public class BlockActionPacket implements ServerPacket {
 
@@ -13,11 +12,11 @@ public class BlockActionPacket implements ServerPacket {
     public int blockId;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writePosition(buffer, blockPosition);
+        writer.writeBlockPosition(blockPosition);
-        buffer.putByte(actionId);
+        writer.writeByte(actionId);
-        buffer.putByte(actionParam);
+        writer.writeByte(actionParam);
-        Utils.writeVarInt(buffer, blockId);
+        writer.writeVarInt(blockId);
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.BlockPosition;
-import fr.themode.minestom.utils.Utils;
 
 public class BlockBreakAnimationPacket implements ServerPacket {
 
@@ -12,10 +11,10 @@ public class BlockBreakAnimationPacket implements ServerPacket {
     public byte destroyStage;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        Utils.writePosition(buffer, blockPosition);
+        writer.writeBlockPosition(blockPosition);
-        buffer.putByte(destroyStage);
+        writer.writeByte(destroyStage);
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.BlockPosition;
-import fr.themode.minestom.utils.Utils;
 
 public class BlockChangePacket implements ServerPacket {
 
@@ -11,9 +10,9 @@ public class BlockChangePacket implements ServerPacket {
     public int blockId;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writePosition(buffer, blockPosition.getX(), blockPosition.getY(), blockPosition.getZ());
+        writer.writeBlockPosition(blockPosition);
-        Utils.writeVarInt(buffer, blockId);
+        writer.writeVarInt(blockId);
     }
 
     @Override

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

@@ -1,10 +1,9 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.bossbar.BarColor;
 import fr.themode.minestom.bossbar.BarDivision;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 import java.util.UUID;
 
@@ -21,33 +20,33 @@ public class BossBarPacket implements ServerPacket {
 
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeUuid(buffer, uuid);
+        writer.writeUuid(uuid);
-        Utils.writeVarInt(buffer, action.ordinal());
+        writer.writeVarInt(action.ordinal());
 
         switch (action) {
             case ADD:
-                Utils.writeString(buffer, title);
+                writer.writeSizedString(title);
-                buffer.putFloat(health);
+                writer.writeFloat(health);
-                Utils.writeVarInt(buffer, color.ordinal());
+                writer.writeVarInt(color.ordinal());
-                Utils.writeVarInt(buffer, division.ordinal());
+                writer.writeVarInt(division.ordinal());
-                buffer.putByte(flags);
+                writer.writeByte(flags);
                 break;
             case REMOVE:
 
                 break;
             case UPDATE_HEALTH:
-                buffer.putFloat(health);
+                writer.writeFloat(health);
                 break;
             case UPDATE_TITLE:
-                Utils.writeString(buffer, title);
+                writer.writeSizedString(title);
                 break;
             case UPDATE_STYLE:
-                Utils.writeVarInt(buffer, color.ordinal());
+                writer.writeVarInt(color.ordinal());
-                Utils.writeVarInt(buffer, division.ordinal());
+                writer.writeVarInt(division.ordinal());
                 break;
             case UPDATE_FLAGS:
-                buffer.putByte(flags);
+                writer.writeByte(flags);
                 break;
         }
     }

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

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 public class ChangeGameStatePacket implements ServerPacket {
@@ -9,9 +9,9 @@ public class ChangeGameStatePacket implements ServerPacket {
     public float value;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putByte((byte) reason.ordinal());
+        writer.writeByte((byte) reason.ordinal());
-        buffer.putFloat(value);
+        writer.writeFloat(value);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ChatMessagePacket implements ServerPacket {
 
@@ -15,9 +14,9 @@ public class ChatMessagePacket implements ServerPacket {
     }
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeString(buffer, this.message);
+        writer.writeSizedString(message);
-        buffer.putByte((byte) this.position.ordinal());
+        writer.writeByte((byte) position.ordinal());
     }
 
     @Override

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

@@ -2,6 +2,7 @@ package fr.themode.minestom.net.packet.server.play;
 
 import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.instance.Chunk;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.BlockPosition;
 import fr.themode.minestom.utils.SerializerUtils;
@@ -19,13 +20,12 @@ public class ChunkDataPacket implements ServerPacket {
 
     public boolean fullChunk;
     public Chunk chunk;
-    // TODO nbt tile entities
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putInt(chunk.getChunkX());
+        writer.writeInt(chunk.getChunkX());
-        buffer.putInt(chunk.getChunkZ());
+        writer.writeInt(chunk.getChunkZ());
-        buffer.putBoolean(fullChunk);
+        writer.writeBoolean(fullChunk);
 
 
         int mask = 0;
@@ -48,7 +48,7 @@ public class ChunkDataPacket implements ServerPacket {
                 blocks.putInt(biomeData[i]);
             }
         }
-        Utils.writeVarInt(buffer, mask);
+        writer.writeVarInt(mask);
 
         // Heightmap
         int[] motionBlocking = new int[16 * 16];
@@ -71,15 +71,15 @@ public class ChunkDataPacket implements ServerPacket {
                 e.printStackTrace();
             }
             byte[] data = outputStream.toByteArray();
-            buffer.putBytes(data);
+            writer.writeBytes(data);
         }
 
-        Utils.writeVarInt(buffer, blocks.length());
+        writer.writeVarInt(blocks.length());
-        buffer.putBuffer(blocks);
+        writer.writeBuffer(blocks);
 
         // Block entities
         Set<Integer> blockEntities = chunk.getBlockEntities();
-        Utils.writeVarInt(buffer, blockEntities.size());
+        writer.writeVarInt(blockEntities.size());
 
         for (Integer index : blockEntities) {
             BlockPosition blockPosition = SerializerUtils.indexToChunkBlockPosition(index);
@@ -94,7 +94,7 @@ public class ChunkDataPacket implements ServerPacket {
                 e.printStackTrace();
             }
             byte[] d = os.toByteArray();
-            buffer.putBytes(d);
+            writer.writeBytes(d);
         }
     }
 

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

@@ -1,16 +1,15 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class CloseWindowPacket implements ServerPacket {
 
     public int windowId;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, windowId);
+        writer.writeVarInt(windowId);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class CollectItemPacket implements ServerPacket {
 
@@ -11,10 +10,10 @@ public class CollectItemPacket implements ServerPacket {
     public int pickupItemCount;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, collectedEntityId);
+        writer.writeVarInt(collectedEntityId);
-        Utils.writeVarInt(buffer, collectorEntityId);
+        writer.writeVarInt(collectorEntityId);
-        Utils.writeVarInt(buffer, pickupItemCount);
+        writer.writeVarInt(pickupItemCount);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ConfirmTransactionPacket implements ServerPacket {
 
@@ -11,10 +10,10 @@ public class ConfirmTransactionPacket implements ServerPacket {
     public boolean accepted;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, windowId);
+        writer.writeVarInt(windowId);
-        buffer.putShort(actionNumber);
+        writer.writeShort(actionNumber);
-        buffer.putBoolean(accepted);
+        writer.writeBoolean(accepted);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 import java.util.function.Consumer;
 
@@ -13,12 +12,12 @@ public class DeclareCommandsPacket implements ServerPacket {
     public int rootIndex;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, nodes.length);
+        writer.writeVarInt(nodes.length);
         for (Node node : nodes) {
-            node.write(buffer);
+            node.write(writer);
         }
-        Utils.writeVarInt(buffer, rootIndex);
+        writer.writeVarInt(rootIndex);
     }
 
     @Override
@@ -33,33 +32,31 @@ public class DeclareCommandsPacket implements ServerPacket {
         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 Consumer<PacketWriter> properties; // Only for argument
         public String suggestionsType; // Only if flags 0x10
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            buffer.putByte(flags);
+            writer.writeByte(flags);
-            Utils.writeVarInt(buffer, children.length);
+
-            for (int child : children) {
+            writer.writeVarIntArray(children);
-                Utils.writeVarInt(buffer, child);
-            }
 
             if ((flags & 0x08) != 0) {
-                Utils.writeVarInt(buffer, redirectedNode);
+                writer.writeVarInt(redirectedNode);
             }
 
             if (isLiteral() || isArgument()) {
-                Utils.writeString(buffer, name);
+                writer.writeSizedString(name);
             }
 
             if (isArgument()) {
-                Utils.writeString(buffer, parser);
+                writer.writeSizedString(parser);
                 if (properties != null) {
-                    properties.accept(buffer);
+                    properties.accept(writer);
                 }
             }
 
             if ((flags & 0x10) != 0) {
-                Utils.writeString(buffer, suggestionsType);
+                writer.writeSizedString(suggestionsType);
             }
 
         }

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

@@ -1,20 +1,15 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class DestroyEntitiesPacket implements ServerPacket {
 
     public int[] entityIds;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityIds.length);
+        writer.writeVarIntArray(entityIds);
-        for (int i = 0; i < entityIds.length; i++) {
-            int entityId = entityIds[i];
-            Utils.writeVarInt(buffer, entityId);
-        }
     }
 
     @Override

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

@@ -1,17 +1,16 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.chat.Chat;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class DisconnectPacket implements ServerPacket {
 
     public String message;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeString(buffer, Chat.rawText(message));
+        writer.writeSizedString(Chat.rawText(message));
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class DisplayScoreboardPacket implements ServerPacket {
 
@@ -10,9 +9,9 @@ public class DisplayScoreboardPacket implements ServerPacket {
     public String scoreName;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putByte(position);
+        writer.writeByte(position);
-        Utils.writeString(buffer, scoreName);
+        writer.writeSizedString(scoreName);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityEffectPacket implements ServerPacket {
 
@@ -13,12 +12,12 @@ public class EntityEffectPacket implements ServerPacket {
     public byte flags;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putByte(effectId);
+        writer.writeByte(effectId);
-        buffer.putByte(amplifier);
+        writer.writeByte(amplifier);
-        Utils.writeVarInt(buffer, duration);
+        writer.writeVarInt(duration);
-        buffer.putByte(flags);
+        writer.writeByte(flags);
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.item.ItemStack;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityEquipmentPacket implements ServerPacket {
 
@@ -12,10 +11,10 @@ public class EntityEquipmentPacket implements ServerPacket {
     public ItemStack itemStack;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        Utils.writeVarInt(buffer, slot.ordinal());
+        writer.writeVarInt(slot.ordinal());
-        Utils.writeItemStack(buffer, itemStack);
+        writer.writeItemStack(itemStack);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityHeadLookPacket implements ServerPacket {
 
@@ -10,9 +9,9 @@ public class EntityHeadLookPacket implements ServerPacket {
     public float yaw;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putByte((byte) (this.yaw * 256 / 360));
+        writer.writeByte((byte) (this.yaw * 256 / 360));
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityLookAndRelativeMovePacket implements ServerPacket {
 
@@ -12,14 +11,14 @@ public class EntityLookAndRelativeMovePacket implements ServerPacket {
     public boolean onGround;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putShort(deltaX);
+        writer.writeShort(deltaX);
-        buffer.putShort(deltaY);
+        writer.writeShort(deltaY);
-        buffer.putShort(deltaZ);
+        writer.writeShort(deltaZ);
-        buffer.putByte((byte) (this.yaw * 256 / 360));
+        writer.writeByte((byte) (yaw * 256 / 360));
-        buffer.putByte((byte) (this.pitch * 256 / 360));
+        writer.writeByte((byte) (pitch * 256 / 360));
-        buffer.putBoolean(onGround);
+        writer.writeBoolean(onGround);
     }
 
 

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityLookPacket implements ServerPacket {
 
@@ -11,11 +10,11 @@ public class EntityLookPacket implements ServerPacket {
     public boolean onGround;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putByte((byte) (this.yaw * 256 / 360));
+        writer.writeByte((byte) (yaw * 256 / 360));
-        buffer.putByte((byte) (this.pitch * 256 / 360));
+        writer.writeByte((byte) (pitch * 256 / 360));
-        buffer.putBoolean(onGround);
+        writer.writeBoolean(onGround);
     }
 
     @Override

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

@@ -1,8 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
 import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityMetaDataPacket implements ServerPacket {
 
@@ -10,10 +10,10 @@ public class EntityMetaDataPacket implements ServerPacket {
     public Buffer data;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putBuffer(data);
+        writer.writeBuffer(data);
-        buffer.putByte((byte) 0xFF);
+        writer.writeByte((byte) 0xFF);
     }
 
     @Override

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

@@ -1,16 +1,15 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityPacket implements ServerPacket {
 
     public int entityId;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityPropertiesPacket implements ServerPacket {
 
@@ -11,11 +10,11 @@ public class EntityPropertiesPacket implements ServerPacket {
 
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putInt(properties.length);
+        writer.writeInt(properties.length);
         for (Property property : properties) {
-            property.write(buffer);
+            property.write(writer);
         }
     }
 
@@ -29,12 +28,12 @@ public class EntityPropertiesPacket implements ServerPacket {
         public String key;
         public double value;
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeString(buffer, key);
+            writer.writeSizedString(key);
-            buffer.putDouble(value);
+            writer.writeDouble(value);
 
-            // TODO Modifiers
+            // TODO modifiers
-            Utils.writeVarInt(buffer, 0);
+            writer.writeVarInt(0);
         }
     }
 

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityRelativeMovePacket implements ServerPacket {
 
@@ -11,12 +10,12 @@ public class EntityRelativeMovePacket implements ServerPacket {
     public boolean onGround;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putShort(deltaX);
+        writer.writeShort(deltaX);
-        buffer.putShort(deltaY);
+        writer.writeShort(deltaY);
-        buffer.putShort(deltaZ);
+        writer.writeShort(deltaZ);
-        buffer.putBoolean(onGround);
+        writer.writeBoolean(onGround);
     }
 
     @Override

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

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 public class EntityStatusPacket implements ServerPacket {
@@ -9,9 +9,9 @@ public class EntityStatusPacket implements ServerPacket {
     public byte status;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putInt(entityId);
+        writer.writeInt(entityId);
-        buffer.putByte(status);
+        writer.writeByte(status);
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.Position;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityTeleportPacket implements ServerPacket {
 
@@ -12,14 +11,14 @@ public class EntityTeleportPacket implements ServerPacket {
     public boolean onGround;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putDouble(position.getX());
+        writer.writeDouble(position.getX());
-        buffer.putDouble(position.getY());
+        writer.writeDouble(position.getY());
-        buffer.putDouble(position.getZ());
+        writer.writeDouble(position.getZ());
-        buffer.putByte((byte) (position.getYaw() * 256f / 360f));
+        writer.writeByte((byte) (position.getYaw() * 256f / 360f));
-        buffer.putByte((byte) (position.getPitch() * 256f / 360f));
+        writer.writeByte((byte) (position.getPitch() * 256f / 360f));
-        buffer.putBoolean(onGround);
+        writer.writeBoolean(onGround);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class EntityVelocityPacket implements ServerPacket {
 
@@ -10,11 +9,11 @@ public class EntityVelocityPacket implements ServerPacket {
     public short velocityX, velocityY, velocityZ;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putShort(velocityX);
+        writer.writeShort(velocityX);
-        buffer.putShort(velocityY);
+        writer.writeShort(velocityY);
-        buffer.putShort(velocityZ);
+        writer.writeShort(velocityZ);
     }
 
     @Override

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

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 public class ExplosionPacket implements ServerPacket {
@@ -11,17 +11,17 @@ public class ExplosionPacket implements ServerPacket {
     public float playerMotionX, playerMotionY, playerMotionZ;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putFloat(x);
+        writer.writeFloat(x);
-        buffer.putFloat(y);
+        writer.writeFloat(y);
-        buffer.putFloat(z);
+        writer.writeFloat(z);
-        buffer.putFloat(radius);
+        writer.writeFloat(radius);
-        buffer.putInt(records.length);
+        writer.writeInt(records.length);
         for (byte record : records)
-            buffer.putByte(record);
+            writer.writeByte(record);
-        buffer.putFloat(playerMotionX);
+        writer.writeFloat(playerMotionX);
-        buffer.putFloat(playerMotionY);
+        writer.writeFloat(playerMotionY);
-        buffer.putFloat(playerMotionZ);
+        writer.writeFloat(playerMotionZ);
     }
 
     @Override

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

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 public class HeldItemChangePacket implements ServerPacket {
@@ -8,8 +8,8 @@ public class HeldItemChangePacket implements ServerPacket {
     public short slot;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putShort(slot);
+        writer.writeShort(slot);
     }
 
     @Override

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

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 public class KeepAlivePacket implements ServerPacket {
@@ -12,8 +12,8 @@ public class KeepAlivePacket implements ServerPacket {
     }
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putLong(id);
+        writer.writeLong(id);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class MultiBlockChangePacket implements ServerPacket {
 
@@ -11,18 +10,21 @@ public class MultiBlockChangePacket implements ServerPacket {
     public BlockChange[] blockChanges;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putInt(chunkX);
+        writer.writeInt(chunkX);
-        buffer.putInt(chunkZ);
+        writer.writeInt(chunkZ);
-        Utils.writeVarInt(buffer, blockChanges == null ? 0 : blockChanges.length);
 
         if (blockChanges != null) {
-            for (int i = 0; i < blockChanges.length; i++) {
+            int length = blockChanges.length;
+            writer.writeVarInt(length);
+            for (int i = 0; i < length; i++) {
                 BlockChange blockChange = blockChanges[i];
-                buffer.putByte(blockChange.positionXZ);
+                writer.writeByte(blockChange.positionXZ);
-                buffer.putByte(blockChange.positionY);
+                writer.writeByte(blockChange.positionY);
-                Utils.writeVarInt(buffer, blockChange.newBlockId);
+                writer.writeVarInt(blockChange.newBlockId);
             }
+        } else {
+            writer.writeVarInt(0);
         }
     }
 

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class OpenWindowPacket implements ServerPacket {
 
@@ -11,10 +10,10 @@ public class OpenWindowPacket implements ServerPacket {
     public String title;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, windowId);
+        writer.writeVarInt(windowId);
-        Utils.writeVarInt(buffer, windowType);
+        writer.writeVarInt(windowType);
-        Utils.writeString(buffer, "{\"text\": \"" + title + " \"}");
+        writer.writeSizedString("{\"text\": \"" + title + " \"}");
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ParticlePacket implements ServerPacket {
 
@@ -16,19 +15,19 @@ public class ParticlePacket implements ServerPacket {
     public int blockId;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putInt(particleId);
+        writer.writeInt(particleId);
-        buffer.putBoolean(longDistance);
+        writer.writeBoolean(longDistance);
-        buffer.putFloat(x);
+        writer.writeFloat(x);
-        buffer.putFloat(y);
+        writer.writeFloat(y);
-        buffer.putFloat(z);
+        writer.writeFloat(z);
-        buffer.putFloat(offsetX);
+        writer.writeFloat(offsetX);
-        buffer.putFloat(offsetY);
+        writer.writeFloat(offsetY);
-        buffer.putFloat(offsetZ);
+        writer.writeFloat(offsetZ);
-        buffer.putFloat(particleData);
+        writer.writeFloat(particleData);
-        buffer.putInt(particleCount);
+        writer.writeInt(particleCount);
         if (particleId == 3)
-            Utils.writeVarInt(buffer, blockId);
+            writer.writeVarInt(blockId);
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.GameMode;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 import java.util.ArrayList;
 import java.util.UUID;
@@ -19,14 +18,14 @@ public class PlayerInfoPacket implements ServerPacket {
     }
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, this.action.ordinal());
+        writer.writeVarInt(action.ordinal());
-        Utils.writeVarInt(buffer, this.playerInfos.size());
+        writer.writeVarInt(playerInfos.size());
+
         for (PlayerInfo playerInfo : this.playerInfos) {
             if (!playerInfo.getClass().equals(action.getClazz())) continue;
-            buffer.putLong(playerInfo.uuid.getMostSignificantBits());
+            writer.writeUuid(playerInfo.uuid);
-            buffer.putLong(playerInfo.uuid.getLeastSignificantBits());
+            playerInfo.write(writer);
-            playerInfo.write(buffer);
         }
     }
 
@@ -62,7 +61,7 @@ public class PlayerInfoPacket implements ServerPacket {
             this.uuid = uuid;
         }
 
-        public abstract void write(Buffer buffer);
+        public abstract void write(PacketWriter writer);
     }
 
     public static class AddPlayer extends PlayerInfo {
@@ -83,17 +82,17 @@ public class PlayerInfoPacket implements ServerPacket {
         }
 
         @Override
-        public void write(Buffer buffer) {
+        public void write(PacketWriter writer) {
-            Utils.writeString(buffer, name);
+            writer.writeSizedString(name);
-            Utils.writeVarInt(buffer, properties.size());
+            writer.writeVarInt(properties.size());
             for (Property property : properties) {
-                property.write(buffer);
+                property.write(writer);
             }
-            Utils.writeVarInt(buffer, gameMode.getId());
+            writer.writeVarInt(gameMode.getId());
-            Utils.writeVarInt(buffer, ping);
+            writer.writeVarInt(ping);
-            buffer.putBoolean(hasDisplayName);
+            writer.writeBoolean(hasDisplayName);
             if (hasDisplayName)
-                Utils.writeString(buffer, displayName);
+                writer.writeSizedString(displayName);
         }
 
         public static class Property {
@@ -108,12 +107,12 @@ public class PlayerInfoPacket implements ServerPacket {
                 this.value = value;
             }
 
-            public void write(Buffer buffer) {
+            public void write(PacketWriter writer) {
-                Utils.writeString(buffer, name);
+                writer.writeSizedString(name);
-                Utils.writeString(buffer, value);
+                writer.writeSizedString(value);
-                buffer.putBoolean(signed);
+                writer.writeBoolean(signed);
                 if (signed)
-                    Utils.writeString(buffer, signature);
+                    writer.writeSizedString(signature);
             }
         }
     }
@@ -128,8 +127,8 @@ public class PlayerInfoPacket implements ServerPacket {
         }
 
         @Override
-        public void write(Buffer buffer) {
+        public void write(PacketWriter writer) {
-            Utils.writeVarInt(buffer, gameMode.getId());
+            writer.writeVarInt(gameMode.getId());
         }
     }
 
@@ -143,8 +142,8 @@ public class PlayerInfoPacket implements ServerPacket {
         }
 
         @Override
-        public void write(Buffer buffer) {
+        public void write(PacketWriter writer) {
-            Utils.writeVarInt(buffer, ping);
+            writer.writeVarInt(ping);
         }
     }
 
@@ -158,9 +157,9 @@ public class PlayerInfoPacket implements ServerPacket {
         }
 
         @Override
-        public void write(Buffer buffer) {
+        public void write(PacketWriter writer) {
-            buffer.putBoolean(true); // ????
+            writer.writeBoolean(true); // ????
-            Utils.writeString(buffer, displayName);
+            writer.writeSizedString(displayName);
         }
     }
 
@@ -171,7 +170,7 @@ public class PlayerInfoPacket implements ServerPacket {
         }
 
         @Override
-        public void write(Buffer buffer) {
+        public void write(PacketWriter writer) {
         }
     }
 }

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.Position;
-import fr.themode.minestom.utils.Utils;
 
 public class PlayerPositionAndLookPacket implements ServerPacket {
 
@@ -13,14 +12,14 @@ public class PlayerPositionAndLookPacket implements ServerPacket {
 
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putDouble(position.getX());
+        writer.writeDouble(position.getX());
-        buffer.putDouble(position.getY());
+        writer.writeDouble(position.getY());
-        buffer.putDouble(position.getZ());
+        writer.writeDouble(position.getZ());
-        buffer.putFloat(position.getYaw());
+        writer.writeFloat(position.getYaw());
-        buffer.putFloat(position.getPitch());
+        writer.writeFloat(position.getPitch());
-        buffer.putBytes(flags);
+        writer.writeByte(flags);
-        Utils.writeVarInt(buffer, teleportId);
+        writer.writeVarInt(teleportId);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class RemoveEntityEffectPacket implements ServerPacket {
 
@@ -10,9 +9,9 @@ public class RemoveEntityEffectPacket implements ServerPacket {
     public byte effectId;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putByte(effectId);
+        writer.writeByte(effectId);
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.entity.GameMode;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 import fr.themode.minestom.world.Dimension;
 import fr.themode.minestom.world.LevelType;
 
@@ -14,14 +13,14 @@ public class RespawnPacket implements ServerPacket {
     public LevelType levelType;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
         int gameModeId = gameMode.getId();
         if (gameMode.isHardcore())
             gameModeId |= 8;
 
-        buffer.putByte((byte) gameModeId);
+        writer.writeByte((byte) gameModeId);
-        buffer.putInt(dimension.getId());
+        writer.writeInt(dimension.getId());
-        Utils.writeString(buffer, levelType.getType());
+        writer.writeSizedString(levelType.getType());
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class ScoreboardObjectivePacket implements ServerPacket {
 
@@ -12,12 +11,13 @@ public class ScoreboardObjectivePacket implements ServerPacket {
     public int type;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeString(buffer, objectiveName);
+        writer.writeSizedString(objectiveName);
-        buffer.putByte(mode);
+        writer.writeByte(mode);
+
         if (mode == 0 || mode == 2) {
-            Utils.writeString(buffer, objectiveValue);
+            writer.writeSizedString(objectiveValue);
-            Utils.writeVarInt(buffer, type);
+            writer.writeVarInt(type);
         }
     }
 

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class SetExperiencePacket implements ServerPacket {
 
@@ -11,10 +10,10 @@ public class SetExperiencePacket implements ServerPacket {
     public int totalExperience;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putFloat(percentage);
+        writer.writeFloat(percentage);
-        Utils.writeVarInt(buffer, level);
+        writer.writeVarInt(level);
-        Utils.writeVarInt(buffer, totalExperience);
+        writer.writeVarInt(totalExperience);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class SetPassengersPacket implements ServerPacket {
 
@@ -10,12 +9,9 @@ public class SetPassengersPacket implements ServerPacket {
     public int[] passengersId;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, vehicleEntityId);
+        writer.writeVarInt(vehicleEntityId);
-        Utils.writeVarInt(buffer, passengersId.length);
+        writer.writeVarIntArray(passengersId);
-        for (int passengerId : passengersId) {
-            Utils.writeVarInt(buffer, passengerId);
-        }
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.item.ItemStack;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class SetSlotPacket implements ServerPacket {
 
@@ -12,10 +11,10 @@ public class SetSlotPacket implements ServerPacket {
     public ItemStack itemStack;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putByte(windowId);
+        writer.writeByte(windowId);
-        buffer.putShort(slot);
+        writer.writeShort(slot);
-        Utils.writeItemStack(buffer, itemStack);
+        writer.writeItemStack(itemStack);
     }
 
     @Override

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

@@ -0,0 +1,26 @@
+package fr.themode.minestom.net.packet.server.play;
+
+import fr.themode.minestom.net.packet.PacketWriter;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+import fr.themode.minestom.utils.Position;
+
+public class SpawnExperienceOrbPacket implements ServerPacket {
+
+    public int entityId;
+    public Position position;
+    public short expCount;
+
+    @Override
+    public void write(PacketWriter writer) {
+        writer.writeVarInt(entityId);
+        writer.writeDouble(position.getX());
+        writer.writeDouble(position.getY());
+        writer.writeDouble(position.getZ());
+        writer.writeShort(expCount);
+    }
+
+    @Override
+    public int getId() {
+        return 0x01;
+    }
+}

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

@@ -1,9 +1,9 @@
 package fr.themode.minestom.net.packet.server.play;
 
 import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.Position;
-import fr.themode.minestom.utils.Utils;
 
 import java.util.UUID;
 
@@ -15,23 +15,27 @@ public class SpawnMobPacket implements ServerPacket {
     public Position position;
     public float headPitch;
     public short velocityX, velocityY, velocityZ;
-    // TODO metadata
+    public Buffer metadata;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        Utils.writeUuid(buffer, entityUuid);
+        writer.writeUuid(entityUuid);
-        Utils.writeVarInt(buffer, entityType);
+        writer.writeVarInt(entityType);
-        buffer.putDouble(position.getX());
+        writer.writeDouble(position.getX());
-        buffer.putDouble(position.getY());
+        writer.writeDouble(position.getY());
-        buffer.putDouble(position.getZ());
+        writer.writeDouble(position.getZ());
-        buffer.putFloat(position.getYaw());
+        writer.writeFloat(position.getYaw());
-        buffer.putFloat(position.getPitch());
+        writer.writeFloat(position.getPitch());
-        buffer.putFloat(headPitch);
+        writer.writeFloat(headPitch);
-        buffer.putShort(velocityX);
+        writer.writeShort(velocityX);
-        buffer.putShort(velocityY);
+        writer.writeShort(velocityY);
-        buffer.putShort(velocityZ);
+        writer.writeShort(velocityZ);
-        buffer.putByte((byte) 0xff); // TODO metadata
+        if (metadata != null) {
+            writer.writeBuffer(metadata);
+        } else {
+            writer.writeByte((byte) 0xff);
+        }
     }
 
     @Override

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.Position;
-import fr.themode.minestom.utils.Utils;
 
 import java.util.UUID;
 
@@ -16,16 +15,16 @@ public class SpawnObjectPacket implements ServerPacket {
     public int data;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        Utils.writeUuid(buffer, uuid);
+        writer.writeUuid(uuid);
-        Utils.writeVarInt(buffer, type);
+        writer.writeVarInt(type);
-        buffer.putDouble(position.getX());
+        writer.writeDouble(position.getX());
-        buffer.putDouble(position.getY());
+        writer.writeDouble(position.getY());
-        buffer.putDouble(position.getZ());
+        writer.writeDouble(position.getZ());
-        buffer.putFloat(position.getYaw());
+        writer.writeFloat(position.getYaw());
-        buffer.putFloat(position.getPitch());
+        writer.writeFloat(position.getPitch());
-        buffer.putInt(data);
+        writer.writeInt(data);
     }
 
     @Override

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

@@ -1,9 +1,9 @@
 package fr.themode.minestom.net.packet.server.play;
 
 import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 import fr.themode.minestom.utils.Position;
-import fr.themode.minestom.utils.Utils;
 
 import java.util.UUID;
 
@@ -15,19 +15,19 @@ public class SpawnPlayerPacket implements ServerPacket {
     public Buffer metadata;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, entityId);
+        writer.writeVarInt(entityId);
-        buffer.putLong(playerUuid.getMostSignificantBits());
+        writer.writeUuid(playerUuid);
-        buffer.putLong(playerUuid.getLeastSignificantBits());
+        writer.writeDouble(position.getX());
-        buffer.putDouble(position.getX());
+        writer.writeDouble(position.getY());
-        buffer.putDouble(position.getY());
+        writer.writeDouble(position.getZ());
-        buffer.putDouble(position.getZ());
+        writer.writeByte((byte) (position.getYaw() * 256f / 360f));
-        buffer.putByte((byte) (position.getYaw() * 256f / 360f));
+        writer.writeByte((byte) (position.getPitch() * 256f / 360f));
-        buffer.putByte((byte) (position.getPitch() * 256f / 360f));
+
         if (metadata != null) {
-            buffer.putBuffer(metadata);
+            writer.writeBuffer(metadata);
         } else {
-            buffer.putByte((byte) 0xff);
+            writer.writeByte((byte) 0xff);
         }
     }
 

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

@@ -1,16 +1,15 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class SpawnPositionPacket implements ServerPacket {
 
     public int x, y, z;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writePosition(buffer, x, y, z);
+        writer.writeBlockPosition(x, y, z);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class TeamsPacket implements ServerPacket {
 
@@ -20,20 +19,20 @@ public class TeamsPacket implements ServerPacket {
     public String[] entities;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeString(buffer, teamName);
+        writer.writeSizedString(teamName);
-        buffer.putByte((byte) action.ordinal());
+        writer.writeByte((byte) action.ordinal());
 
         switch (action) {
             case CREATE_TEAM:
             case UPDATE_TEAM_INFO:
-                Utils.writeString(buffer, teamDisplayName);
+                writer.writeSizedString(teamDisplayName);
-                buffer.putByte(friendlyFlags);
+                writer.writeByte(friendlyFlags);
-                Utils.writeString(buffer, nameTagVisibility);
+                writer.writeSizedString(nameTagVisibility);
-                Utils.writeString(buffer, collisionRule);
+                writer.writeSizedString(collisionRule);
-                Utils.writeVarInt(buffer, teamColor);
+                writer.writeVarInt(teamColor);
-                Utils.writeString(buffer, teamPrefix);
+                writer.writeSizedString(teamPrefix);
-                Utils.writeString(buffer, teamSuffix);
+                writer.writeSizedString(teamSuffix);
                 break;
             case REMOVE_TEAM:
 
@@ -41,15 +40,7 @@ public class TeamsPacket implements ServerPacket {
         }
 
         if (action == Action.CREATE_TEAM || action == Action.ADD_PLAYERS_TEAM || action == Action.REMOVE_PLAYERS_TEAM) {
-            if (entities == null) {
+            writer.writeStringArray(entities);
-                Utils.writeVarInt(buffer, 0);
-                return;
-            }
-
-            Utils.writeVarInt(buffer, entities.length);
-            for (String entity : entities) {
-                Utils.writeString(buffer, entity);
-            }
         }
 
     }

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.item.ItemStack;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class TradeListPacket implements ServerPacket {
 
@@ -15,16 +14,16 @@ public class TradeListPacket implements ServerPacket {
     public boolean canRestock;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, windowId);
+        writer.writeVarInt(windowId);
-        buffer.putByte((byte) trades.length);
+        writer.writeByte((byte) trades.length);
         for (Trade trade : trades) {
-            trade.write(buffer);
+            trade.write(writer);
         }
-        Utils.writeVarInt(buffer, villagerLevel);
+        writer.writeVarInt(villagerLevel);
-        Utils.writeVarInt(buffer, experience);
+        writer.writeVarInt(experience);
-        buffer.putBoolean(regularVillager);
+        writer.writeBoolean(regularVillager);
-        buffer.putBoolean(canRestock);
+        writer.writeBoolean(canRestock);
     }
 
     @Override
@@ -46,19 +45,21 @@ public class TradeListPacket implements ServerPacket {
         public int demand;
 
 
-        private void write(Buffer buffer) {
+        private void write(PacketWriter writer) {
-            Utils.writeItemStack(buffer, inputItem1);
+            boolean hasSecondItem = inputItem2 != null;
-            Utils.writeItemStack(buffer, result);
+
-            buffer.putBoolean(inputItem2 != null);
+            writer.writeItemStack(inputItem1);
-            if (inputItem2 != null)
+            writer.writeItemStack(result);
-                Utils.writeItemStack(buffer, inputItem2);
+            writer.writeBoolean(hasSecondItem);
-            buffer.putBoolean(tradeDisabled);
+            if (hasSecondItem)
-            buffer.putInt(tradeUsesNumber);
+                writer.writeItemStack(inputItem2);
-            buffer.putInt(maxTradeUsesNumber);
+            writer.writeBoolean(tradeDisabled);
-            buffer.putInt(exp);
+            writer.writeInt(tradeUsesNumber);
-            buffer.putInt(specialPrice);
+            writer.writeInt(maxTradeUsesNumber);
-            buffer.putFloat(priceMultiplier);
+            writer.writeInt(exp);
-            buffer.putInt(demand);
+            writer.writeInt(specialPrice);
+            writer.writeFloat(priceMultiplier);
+            writer.writeInt(demand);
         }
 
     }

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

@@ -1,6 +1,6 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
 
 public class UnloadChunkPacket implements ServerPacket {
@@ -8,9 +8,9 @@ public class UnloadChunkPacket implements ServerPacket {
     public int chunkX, chunkZ;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putInt(chunkX);
+        writer.writeInt(chunkX);
-        buffer.putInt(chunkZ);
+        writer.writeInt(chunkZ);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class UpdateHealthPacket implements ServerPacket {
 
@@ -11,10 +10,10 @@ public class UpdateHealthPacket implements ServerPacket {
     public float foodSaturation;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        buffer.putFloat(health);
+        writer.writeFloat(health);
-        Utils.writeVarInt(buffer, food);
+        writer.writeVarInt(food);
-        buffer.putFloat(foodSaturation);
+        writer.writeFloat(foodSaturation);
     }
 
     @Override

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

@@ -1,8 +1,7 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class UpdateScorePacket implements ServerPacket {
 
@@ -12,12 +11,12 @@ public class UpdateScorePacket implements ServerPacket {
     public int value;
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeString(buffer, entityName);
+        writer.writeSizedString(entityName);
-        buffer.putByte(action);
+        writer.writeByte(action);
-        Utils.writeString(buffer, objectiveName);
+        writer.writeSizedString(objectiveName);
         if (action != 1) {
-            Utils.writeVarInt(buffer, value);
+            writer.writeVarInt(value);
         }
     }
 

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

@@ -1,9 +1,8 @@
 package fr.themode.minestom.net.packet.server.play;
 
-import fr.adamaq01.ozao.net.Buffer;
 import fr.themode.minestom.instance.Chunk;
+import fr.themode.minestom.net.packet.PacketWriter;
 import fr.themode.minestom.net.packet.server.ServerPacket;
-import fr.themode.minestom.utils.Utils;
 
 public class UpdateViewPositionPacket implements ServerPacket {
 
@@ -14,9 +13,9 @@ public class UpdateViewPositionPacket implements ServerPacket {
     }
 
     @Override
-    public void write(Buffer buffer) {
+    public void write(PacketWriter writer) {
-        Utils.writeVarInt(buffer, chunk.getChunkX());
+        writer.writeVarInt(chunk.getChunkX());
-        Utils.writeVarInt(buffer, chunk.getChunkZ());
+        writer.writeVarInt(chunk.getChunkZ());
     }
 
     @Override