Problem Sync Client-server for Entity Mount

[vals_kenway]

Version 1.19 - Forge 41.0.63

I want to create a wolf entity that I can ride, so far it seems to be working, but the problem is that when I get on the wolf, I can’t control it. I then discovered that the issue is that the server doesn’t detect that I’m riding the wolf, so I’m struggling with synchronization. However, it seems to not be working properly. As I understand it, the server receives the packet but doesn’t register it correctly. I’m a bit new to Java, and I’ll try to provide all the relevant code and prints

*The comments and prints are translated by chatgpt since they were originally in Spanish*

Thank you very much in advance

No player is mounted, or the passenger is not a player.
No player is mounted, or the passenger is not a player.
No player is mounted, or the passenger is not a player.
No player is mounted, or the passenger is not a player.
No player is mounted, or the passenger is not a player.

MountableWolfEntity

package com.vals.valscraft.entity;

import com.vals.valscraft.network.MountSyncPacket;
import com.vals.valscraft.network.NetworkHandler;
import net.minecraft.client.Minecraft;
import net.minecraft.network.syncher.EntityDataAccessor;
import net.minecraft.network.syncher.EntityDataSerializers;
import net.minecraft.network.syncher.SynchedEntityData;
import net.minecraft.server.MinecraftServer;
import net.minecraft.server.level.ServerPlayer;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.Mob;
import net.minecraft.world.entity.ai.attributes.AttributeSupplier;
import net.minecraft.world.entity.ai.attributes.Attributes;
import net.minecraft.world.entity.animal.Wolf;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.InteractionHand;
import net.minecraft.world.InteractionResult;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.Items;
import net.minecraft.world.level.Level;
import net.minecraft.world.phys.Vec3;
import net.minecraftforge.event.TickEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.network.PacketDistributor;

public class MountableWolfEntity extends Wolf {
    private boolean hasSaddle;
    private static final EntityDataAccessor<Byte> DATA_ID_FLAGS = SynchedEntityData.defineId(MountableWolfEntity.class, EntityDataSerializers.BYTE);

    public MountableWolfEntity(EntityType<? extends Wolf> type, Level level) {
        super(type, level);
        this.hasSaddle = false;
    }

    @Override
    protected void defineSynchedData() {
        super.defineSynchedData();
        this.entityData.define(DATA_ID_FLAGS, (byte)0);
    }

    public static AttributeSupplier.Builder createAttributes() {
        return Wolf.createAttributes()
                .add(Attributes.MAX_HEALTH, 20.0)
                .add(Attributes.MOVEMENT_SPEED, 0.3);
    }

    @Override
    public InteractionResult mobInteract(Player player, InteractionHand hand) {
        ItemStack itemstack = player.getItemInHand(hand);

        if (itemstack.getItem() == Items.SADDLE && !this.hasSaddle()) {
            if (!player.isCreative()) {
                itemstack.shrink(1);
            }
            this.setSaddle(true);
            return InteractionResult.SUCCESS;
        } else if (!level.isClientSide && this.hasSaddle()) {
            player.startRiding(this);
            MountSyncPacket packet = new MountSyncPacket(true);  // 'true' means the player is mounted
            NetworkHandler.CHANNEL.sendToServer(packet);  // Ensure the server handles the packet
            return InteractionResult.SUCCESS;
        }
        return InteractionResult.PASS;
    }

    @Override
    public void travel(Vec3 travelVector) {
        if (this.isVehicle() && this.getControllingPassenger() instanceof Player) {
            System.out.println("The wolf has a passenger.");
            System.out.println("The passenger is a player.");

            Player player = (Player) this.getControllingPassenger();  // Ensure the player is the controller
            this.setYRot(player.getYRot());
            this.yRotO = this.getYRot();
            this.setXRot(player.getXRot() * 0.5F);
            this.setRot(this.getYRot(), this.getXRot());
            this.yBodyRot = this.getYRot();
            this.yHeadRot = this.yBodyRot;

            float forward = player.zza;
            float strafe = player.xxa;

            if (forward <= 0.0F) {
                forward *= 0.25F;
            }

            this.flyingSpeed = this.getSpeed() * 0.1F;
            this.setSpeed((float) this.getAttributeValue(Attributes.MOVEMENT_SPEED) * 1.5F);
            this.setDeltaMovement(new Vec3(strafe, travelVector.y, forward).scale(this.getSpeed()));

            this.calculateEntityAnimation(this, false);
        } else {
            // The wolf does not have a passenger or the passenger is not a player
            System.out.println("No player is mounted, or the passenger is not a player.");
            super.travel(travelVector);
        }
    }

    public boolean hasSaddle() {
        return this.hasSaddle;
    }

    public void setSaddle(boolean hasSaddle) {
        this.hasSaddle = hasSaddle;
    }

    @Override
    protected void dropEquipment() {
        super.dropEquipment();
        if (this.hasSaddle()) {
            this.spawnAtLocation(Items.SADDLE);
            this.setSaddle(false);
        }
    }

    @SubscribeEvent
    public static void onServerTick(TickEvent.ServerTickEvent event) {
        if (event.phase == TickEvent.Phase.START) {
            MinecraftServer server = net.minecraftforge.server.ServerLifecycleHooks.getCurrentServer();
            if (server != null) {
                for (ServerPlayer player : server.getPlayerList().getPlayers()) {
                    if (player.isPassenger() && player.getVehicle() instanceof MountableWolfEntity) {
                        MountableWolfEntity wolf = (MountableWolfEntity) player.getVehicle();
                        System.out.println("Tick: " + player.getName().getString() + " is correctly mounted on " + wolf);
                    }
                }
            }
        }
    }
    private boolean lastMountedState = false;

    @Override
    public void tick() {
        super.tick();

        if (!this.level.isClientSide) {  // Only on the server
            boolean isMounted = this.isVehicle() && this.getControllingPassenger() instanceof Player;

            // Only print if the state changed
            if (isMounted != lastMountedState) {
                if (isMounted) {
                    Player player = (Player) this.getControllingPassenger();  // Verify the passenger is a player
                    System.out.println("Server: Player " + player.getName().getString() + " is now mounted.");
                } else {
                    System.out.println("Server: The wolf no longer has a passenger.");
                }
                lastMountedState = isMounted;
            }
        }
    }

    @Override
    public void addPassenger(Entity passenger) {
        super.addPassenger(passenger);
        if (passenger instanceof Player) {
            Player player = (Player) passenger;
            if (!this.level.isClientSide && player instanceof ServerPlayer) {
                // Send the packet to the server to indicate the player is mounted
                NetworkHandler.CHANNEL.send(PacketDistributor.PLAYER.with(() -> (ServerPlayer) player), new MountSyncPacket(true));
            }
        }
    }

    @Override
    public void removePassenger(Entity passenger) {
        super.removePassenger(passenger);
        if (passenger instanceof Player) {
            Player player = (Player) passenger;
            if (!this.level.isClientSide && player instanceof ServerPlayer) {
                // Send the packet to the server to indicate the player is no longer mounted
                NetworkHandler.CHANNEL.send(PacketDistributor.PLAYER.with(() -> (ServerPlayer) player), new MountSyncPacket(false));
            }
        }
    }

    @Override
    public boolean isControlledByLocalInstance() {
        Entity entity = this.getControllingPassenger();
        return entity instanceof Player;
    }

    @Override
    public void positionRider(Entity passenger) {
        if (this.hasPassenger(passenger)) {
            double xOffset = Math.cos(Math.toRadians(this.getYRot() + 90)) * 0.4;
            double zOffset = Math.sin(Math.toRadians(this.getYRot() + 90)) * 0.4;
            passenger.setPos(this.getX() + xOffset, this.getY() + this.getPassengersRidingOffset() + passenger.getMyRidingOffset(), this.getZ() + zOffset);
        }
    }
}

MountSyncPacket

package com.vals.valscraft.network;

import com.vals.valscraft.entity.MountableWolfEntity;
import net.minecraft.network.FriendlyByteBuf;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.server.level.ServerPlayer;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.player.Player;
import net.minecraftforge.network.NetworkEvent;

import java.util.function.Supplier;

public class MountSyncPacket {
    private final boolean isMounted;

    public MountSyncPacket(boolean isMounted) {
        this.isMounted = isMounted;
    }

    public void encode(FriendlyByteBuf buffer) {
        buffer.writeBoolean(isMounted);
    }

    public static MountSyncPacket decode(FriendlyByteBuf buffer) {
        return new MountSyncPacket(buffer.readBoolean());
    }

    public void handle(NetworkEvent.Context context) {
        context.enqueueWork(() -> {
            ServerPlayer player = context.getSender(); // Get the player from the context
            if (player != null) {
                // Verifies if the player has dismounted
                if (!isMounted) {
                    Entity vehicle = player.getVehicle();
                    if (vehicle instanceof MountableWolfEntity wolf) {
                        // Logic to remove the player as a passenger
                        wolf.removePassenger(player);
                        System.out.println("Server: Player " + player.getName().getString() + " is no longer mounted.");
                    }
                }
            }
        });
        context.setPacketHandled(true); // Marks the packet as handled
    }

}

networkHandler

package com.vals.valscraft.network;

import com.vals.valscraft.valscraft;
import net.minecraft.resources.ResourceLocation;
import net.minecraftforge.network.NetworkRegistry;
import net.minecraftforge.network.simple.SimpleChannel;
import net.minecraftforge.network.NetworkEvent;

import java.util.function.Supplier;

public class NetworkHandler {
    private static final String PROTOCOL_VERSION = "1";
    public static final SimpleChannel CHANNEL = NetworkRegistry.newSimpleChannel(
            new ResourceLocation(valscraft.MODID, "main"),
            () -> PROTOCOL_VERSION,
            PROTOCOL_VERSION::equals,
            PROTOCOL_VERSION::equals
    );
    public static void init() {
        int packetId = 0;

        // Register the mount synchronization packet
        CHANNEL.registerMessage(
                packetId++,
                MountSyncPacket.class,
                MountSyncPacket::encode,
                MountSyncPacket::decode,
                (msg, context) -> msg.handle(context.get())  // Get the context with context.get()
        );

    }
}

 

Edited November 27, 2024 by vals_kenway