Use the proper packet to close the loading screen

Tested on 1.21.1

src/main/java/org/geysermc/globallinkserver/java/JavaServer.java

@@ -1,36 +1,20 @@
 /*
  * Copyright (c) 2021-2024 GeyserMC
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- *
- * @author GeyserMC
+ * Licensed under the MIT license
  * @link https://github.com/GeyserMC/GlobalLinkServer
  */
 package org.geysermc.globallinkserver.java;
 
 import static org.geysermc.mcprotocollib.protocol.codec.MinecraftCodec.CODEC;
 
+import java.util.BitSet;
 import java.util.Collections;
+import java.util.List;
 import java.util.OptionalInt;
 import net.kyori.adventure.key.Key;
 import net.kyori.adventure.text.Component;
 import org.cloudburstmc.math.vector.Vector3i;
+import org.cloudburstmc.nbt.NbtMap;
 import org.geysermc.globallinkserver.config.Config;
 import org.geysermc.globallinkserver.link.LinkManager;
 import org.geysermc.globallinkserver.player.PlayerManager;
@@ -43,30 +27,32 @@
 import org.geysermc.mcprotocollib.network.tcp.TcpServer;
 import org.geysermc.mcprotocollib.protocol.MinecraftConstants;
 import org.geysermc.mcprotocollib.protocol.MinecraftProtocol;
-import org.geysermc.mcprotocollib.protocol.ServerLoginHandler;
 import org.geysermc.mcprotocollib.protocol.data.game.command.CommandNode;
 import org.geysermc.mcprotocollib.protocol.data.game.command.CommandParser;
 import org.geysermc.mcprotocollib.protocol.data.game.command.CommandType;
 import org.geysermc.mcprotocollib.protocol.data.game.command.properties.IntegerProperties;
 import org.geysermc.mcprotocollib.protocol.data.game.entity.player.GameMode;
 import org.geysermc.mcprotocollib.protocol.data.game.entity.player.PlayerSpawnInfo;
+import org.geysermc.mcprotocollib.protocol.data.game.level.LightUpdateData;
+import org.geysermc.mcprotocollib.protocol.data.game.level.block.BlockEntityInfo;
 import org.geysermc.mcprotocollib.protocol.data.game.level.notify.GameEvent;
 import org.geysermc.mcprotocollib.protocol.data.status.PlayerInfo;
 import org.geysermc.mcprotocollib.protocol.data.status.ServerStatusInfo;
 import org.geysermc.mcprotocollib.protocol.data.status.VersionInfo;
-import org.geysermc.mcprotocollib.protocol.data.status.handler.ServerInfoBuilder;
 import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.ClientboundCommandsPacket;
 import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.ClientboundLoginPacket;
 import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.entity.player.ClientboundPlayerAbilitiesPacket;
 import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.entity.player.ClientboundPlayerPositionPacket;
-import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.entity.player.ClientboundSetHealthPacket;
 import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.level.ClientboundGameEventPacket;
+import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.level.ClientboundLevelChunkWithLightPacket;
 import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.level.ClientboundSetDefaultSpawnPositionPacket;
 
 public class JavaServer implements org.geysermc.globallinkserver.Server {
     private final PlayerManager playerManager;
     private final LinkManager linkManager;
 
+    private final ClientboundLevelChunkWithLightPacket cachedChunk = cachedChunk();
+
     private final ServerStatusInfo pong = new ServerStatusInfo(
             Component.text("Global Link Server"),
             new PlayerInfo(1, 0, Collections.emptyList()),
@@ -91,8 +77,8 @@ public boolean startServer(Config config) {
 
         server.setGlobalFlag(MinecraftConstants.SESSION_SERVICE_KEY, new SessionService());
         server.setGlobalFlag(MinecraftConstants.VERIFY_USERS_KEY, true);
-        server.setGlobalFlag(MinecraftConstants.SERVER_INFO_BUILDER_KEY, (ServerInfoBuilder) session -> pong);
-        server.setGlobalFlag(MinecraftConstants.SERVER_LOGIN_HANDLER_KEY, (ServerLoginHandler) session -> {
+        server.setGlobalFlag(MinecraftConstants.SERVER_INFO_BUILDER_KEY, session -> pong);
+        server.setGlobalFlag(MinecraftConstants.SERVER_LOGIN_HANDLER_KEY, session -> {
             session.send(new ClientboundCommandsPacket(
                     new CommandNode[] {
                         new CommandNode(
@@ -151,20 +137,16 @@ public boolean startServer(Config config) {
 
             session.send(new ClientboundPlayerAbilitiesPacket(false, false, true, false, 0f, 0f));
 
-            // without this the player will spawn only after waiting 30 seconds
-            // there are multiple options to fix that,
-            // but this is the best option as we don't want to send chunk and the player is in spectator anyway
-            session.send(new ClientboundSetHealthPacket(0, 0, 0));
-
             // this packet is also required to let our player spawn, but the location itself doesn't matter
             session.send(new ClientboundSetDefaultSpawnPositionPacket(Vector3i.ZERO, 0));
 
             // we have to listen to the teleport confirm on the PacketHandler to prevent respawn request packet spam,
             // so send it after calling ConnectedEvent which adds the PacketHandler as listener
             session.send(new ClientboundPlayerPositionPacket(0, 0, 0, 0, 0, 0));
 
-            // this packet is required since 1.20.3
+            // these packets are required since 1.20.3
             session.send(new ClientboundGameEventPacket(GameEvent.LEVEL_CHUNKS_LOAD_START, null));
+            session.send(cachedChunk);
 
             // Manually call the connect event
             session.callEvent(new ConnectedEvent(session));
@@ -192,4 +174,22 @@ public void shutdown() {
         server.close();
         server = null;
     }
+
+    private ClientboundLevelChunkWithLightPacket cachedChunk() {
+        // 8 bytes for every section:
+        // short - block count
+        // for both blocks and biomes:
+        // byte - bits per entry
+        // varint(1) - block ID (0, air)
+        // varint(1) - data length
+        // times 16 for the 16 chunk sections that the end biome has
+        byte[] chunkData = new byte[8 * 16];
+
+        // just setting everything to empty seems to do the trick
+        var lightData =
+                new LightUpdateData(new BitSet(), new BitSet(), new BitSet(), new BitSet(), List.of(), List.of());
+        // same applies for the heightmaps
+        return new ClientboundLevelChunkWithLightPacket(
+                0, 0, chunkData, NbtMap.EMPTY, new BlockEntityInfo[0], lightData);
+    }
 }