GamePacketEncoder.java

package com.osroyale.net.codec.game;
 
import com.osroyale.net.packet.GamePacket;
import com.osroyale.net.packet.PacketType;
import com.osroyale.net.codec.IsaacCipher;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
 
public class GamePacketEncoder extends MessageToByteEncoder<GamePacket> {
     
    private final IsaacCipher encryptor;
 
    public GamePacketEncoder(IsaacCipher encryptor) {
        this.encryptor = encryptor;
    }
 
    @Override
    protected void encode(ChannelHandlerContext ctx, GamePacket packet, ByteBuf out) throws Exception {
        out.writeByte((packet.getOpcode() + (encryptor.getKey() & 0xFF)) & 0xFF);
        if (packet.getHeader() == PacketType.VAR_BYTE) {
            out.writeByte(packet.getSize());
        } else if (packet.getHeader() == PacketType.VAR_SHORT) {
            out.writeShort(packet.getSize());
        }
        out.writeBytes(packet.getPayload());
    }
 
}