feat: add support for multipart entity (close #364)

src/main/java/snownee/jade/api/EntityAccessor.java

@@ -17,6 +17,14 @@ public interface EntityAccessor extends Accessor<EntityHitResult> {
 
 	Entity getEntity();
 
+	/**
+	 * For part entity like ender dragon's, getEntity() will return the parent entity.
+	 */
+	//TODO 1.21: remove default implementation
+	default Entity getRawEntity() {
+		return getEntity();
+	}
+
 	@Override
 	default Class<? extends Accessor<?>> getAccessorType() {
 		return EntityAccessor.class;

src/main/java/snownee/jade/impl/EntityAccessorImpl.java

@@ -64,7 +64,13 @@ public static void handleRequest(SyncData data, ServerPlayer player, Consumer<Ru
 	@Deprecated
 	public void toNetwork(FriendlyByteBuf buf) {
 		buf.writeBoolean(showDetails());
-		buf.writeVarInt(entity.get().getId());
+		Entity entity = getEntity();
+		buf.writeVarInt(entity.getId());
+		if (CommonProxy.isMultipartEntity(entity)) {
+			buf.writeVarInt(CommonProxy.getPartEntityIndex(entity));
+		} else {
+			buf.writeVarInt(-1);
+		}
 		Vec3 hitVec = getHitResult().getLocation();
 		buf.writeFloat((float) hitVec.x);
 		buf.writeFloat((float) hitVec.y);
@@ -73,6 +79,11 @@ public void toNetwork(FriendlyByteBuf buf) {
 
 	@Override
 	public Entity getEntity() {
+		return CommonProxy.wrapPartEntityParent(getRawEntity());
+	}
+
+	@Override
+	public Entity getRawEntity() {
 		return entity.get();
 	}
 
@@ -176,13 +187,13 @@ public EntityAccessor build() {
 		}
 	}
 
-	public record SyncData(boolean showDetails, int id, Vec3 hitVec) {
+	public record SyncData(boolean showDetails, int id, int partIndex, Vec3 hitVec) {
 		public SyncData(EntityAccessor accessor) {
-			this(accessor.showDetails(), accessor.getEntity().getId(), accessor.getHitResult().getLocation());
+			this(accessor.showDetails(), accessor.getEntity().getId(), CommonProxy.getPartEntityIndex(accessor.getRawEntity()), accessor.getHitResult().getLocation());
 		}
 
 		public SyncData(FriendlyByteBuf buffer) {
-			this(buffer.readBoolean(), buffer.readInt(), new Vec3(buffer.readFloat(), buffer.readFloat(), buffer.readFloat()));
+			this(buffer.readBoolean(), buffer.readVarInt(), buffer.readVarInt(), new Vec3(buffer.readFloat(), buffer.readFloat(), buffer.readFloat()));
 		}
 
 		public void write(FriendlyByteBuf buffer) {
@@ -194,7 +205,7 @@ public void write(FriendlyByteBuf buffer) {
 		}
 
 		public EntityAccessor unpack(ServerPlayer player) {
-			Supplier<Entity> entity = Suppliers.memoize(() -> player.level().getEntity(id));
+			Supplier<Entity> entity = Suppliers.memoize(() -> CommonProxy.getPartEntity(player.level().getEntity(id), partIndex));
 			return new EntityAccessorImpl.Builder()
 					.level(player.level())
 					.player(player)

src/main/java/snownee/jade/overlay/RayTracing.java

@@ -30,6 +30,7 @@
 import snownee.jade.impl.ObjectDataCenter;
 import snownee.jade.impl.WailaClientRegistration;
 import snownee.jade.impl.ui.ItemStackElement;
+import snownee.jade.util.CommonProxy;
 
 public class RayTracing {
 
@@ -171,6 +172,8 @@ private boolean canBeTarget(Entity target, Entity viewEntity) {
 			return false;
 		if (target instanceof Projectile projectile && projectile.tickCount <= 10 && !target.level().tickRateManager().isEntityFrozen(target))
 			return false;
+		if (CommonProxy.isMultipartEntity(target) && !target.isPickable())
+			return false;
 		if (viewEntity instanceof Player player) {
 			if (target.isInvisibleTo(player))
 				return false;

src/main/java/snownee/jade/util/CommonProxy.java

@@ -49,6 +49,7 @@
 import net.neoforged.neoforge.common.Tags;
 import net.neoforged.neoforge.common.UsernameCache;
 import net.neoforged.neoforge.energy.IEnergyStorage;
+import net.neoforged.neoforge.entity.PartEntity;
 import net.neoforged.neoforge.event.RegisterCommandsEvent;
 import net.neoforged.neoforge.event.entity.player.PlayerEvent;
 import net.neoforged.neoforge.fluids.FluidStack;
@@ -94,7 +95,7 @@ public CommonProxy(IEventBus modBus) {
 
 	private void registerPayloadHandlers(RegisterPayloadHandlerEvent event) {
 		event.registrar(Jade.MODID)
-				.versioned("1")
+				.versioned("2")
 				.optional()
 				.play(Identifiers.PACKET_RECEIVE_DATA, ReceiveDataPacket::read, handlers -> handlers.client(ReceiveDataPacket::handle))
 				.play(Identifiers.PACKET_SERVER_PING, ServerPingPacket::read, handlers -> handlers.client(ServerPingPacket::handle))
@@ -352,4 +353,41 @@ private void loadComplete(FMLLoadCompleteEvent event) {
 		}
 		Jade.loadComplete();
 	}
+
+	public static boolean isMultipartEntity(Entity target) {
+		return target.isMultipartEntity();
+	}
+
+	public static Entity wrapPartEntityParent(Entity target) {
+		if (target instanceof PartEntity<?> part) {
+			return part.getParent();
+		}
+		return target;
+	}
+
+	public static int getPartEntityIndex(Entity entity) {
+		if (!(entity instanceof PartEntity<?> part)) {
+			return -1;
+		}
+		Entity parent = wrapPartEntityParent(entity);
+		PartEntity<?>[] parts = parent.getParts();
+		if (parts == null) {
+			return -1;
+		}
+		return List.of(parts).indexOf(part);
+	}
+
+	public static Entity getPartEntity(Entity parent, int index) {
+		if (parent == null) {
+			return null;
+		}
+		if (index < 0) {
+			return parent;
+		}
+		PartEntity<?>[] parts = parent.getParts();
+		if (parts == null || index >= parts.length) {
+			return parent;
+		}
+		return parts[index];
+	}
 }