Fix empty chunk encoding

core/src/main/java/org/geysermc/geyser/translator/protocol/java/JavaLoginTranslator.java

@@ -99,6 +99,8 @@ public class JavaLoginTranslator extends PacketTranslator<ClientboundLoginPacket
         if (needsSpawnPacket) {
             // The player has yet to spawn so let's do that using some of the information in this Java packet
             session.setDimension(newDimension);
+            session.setDimensionType(dimensions.get(newDimension));
+            ChunkUtils.loadDimension(session);
             session.connect();
 
             // It is now safe to send these packets
@@ -145,8 +147,5 @@ public class JavaLoginTranslator extends PacketTranslator<ClientboundLoginPacket
             // If the player is spawning into the "fake" nether, send them some fog
             session.sendFog("minecraft:fog_hell");
         }
-
-        session.setDimensionType(dimensions.get(newDimension));
-        ChunkUtils.loadDimension(session);
     }
 }

core/src/main/java/org/geysermc/geyser/translator/protocol/java/JavaRespawnTranslator.java

@@ -36,7 +36,6 @@ import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.inventory.InventoryTranslator;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
 import org.geysermc.geyser.translator.protocol.Translator;
-import org.geysermc.geyser.util.ChunkUtils;
 import org.geysermc.geyser.util.DimensionUtils;
 
 @Translator(packet = ClientboundRespawnPacket.class)
@@ -93,9 +92,6 @@ public class JavaRespawnTranslator extends PacketTranslator<ClientboundRespawnPa
             }
             session.setWorldName(packet.getWorldName());
             DimensionUtils.switchDimension(session, newDimension);
-
-            session.setDimensionType(session.getDimensions().get(newDimension));
-            ChunkUtils.loadDimension(session);
         }
     }
 }

core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaLevelChunkWithLightTranslator.java

@@ -39,7 +39,6 @@ import com.nukkitx.math.vector.Vector3i;
 import com.nukkitx.nbt.NBTOutputStream;
 import com.nukkitx.nbt.NbtMap;
 import com.nukkitx.nbt.NbtUtils;
-import com.nukkitx.network.VarInts;
 import com.nukkitx.protocol.bedrock.packet.LevelChunkPacket;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
@@ -284,6 +283,9 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
             }
             sectionCount++;
 
+            // As of 1.18.30, the amount of biomes read is dependent on how high Bedrock thinks the dimension is
+            int biomeCount = bedrockDimension.height() >> 4;
+
             // Estimate chunk size
             int size = 0;
             for (int i = 0; i < sectionCount; i++) {
@@ -294,9 +296,8 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                     size += SERIALIZED_CHUNK_DATA.length;
                 }
             }
-            size += ChunkUtils.EMPTY_CHUNK_DATA.length; // Consists only of biome data
+            size += ChunkUtils.EMPTY_BIOME_DATA.length * biomeCount;
             size += 1; // Border blocks
-            size += 1; // Extra data length (always 0)
             size += bedrockBlockEntities.size() * 64; // Conservative estimate of 64 bytes per tile entity
 
             // Allocate output buffer
@@ -310,8 +311,6 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
                 }
             }
 
-            // As of 1.18.30, the amount of biomes read is dependent on how high Bedrock thinks the dimension is
-            int biomeCount = bedrockDimension.height() >> 4;
             int dimensionOffset = bedrockDimension.minY() >> 4;
             for (int i = 0; i < biomeCount; i++) {
                 int biomeYOffset = dimensionOffset + i;
@@ -331,7 +330,6 @@ public class JavaLevelChunkWithLightTranslator extends PacketTranslator<Clientbo
             }
 
             byteBuf.writeByte(0); // Border blocks - Edu edition only
-            VarInts.writeUnsignedInt(byteBuf, 0); // extra data length, 0 for now
 
             // Encode tile entities into buffer
             NBTOutputStream nbtStream = NbtUtils.createNetworkWriter(new ByteBufOutputStream(byteBuf));

core/src/main/java/org/geysermc/geyser/util/ChunkUtils.java

@@ -31,6 +31,7 @@ import com.nukkitx.protocol.bedrock.packet.LevelChunkPacket;
 import com.nukkitx.protocol.bedrock.packet.NetworkChunkPublisherUpdatePacket;
 import com.nukkitx.protocol.bedrock.packet.UpdateBlockPacket;
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufAllocator;
 import io.netty.buffer.Unpooled;
 import it.unimi.dsi.fastutil.ints.IntLists;
 import lombok.experimental.UtilityClass;
@@ -54,10 +55,6 @@ public class ChunkUtils {
      * An empty subchunk.
      */
     public static final byte[] SERIALIZED_CHUNK_DATA;
-    /**
-     * An empty chunk that can be safely passed on to a LevelChunkPacket with subcounts set to 0.
-     */
-    public static final byte[] EMPTY_CHUNK_DATA;
     public static final byte[] EMPTY_BIOME_DATA;
 
     static {
@@ -81,20 +78,6 @@ public class ChunkUtils {
         } finally {
             byteBuf.release();
         }
-
-        byteBuf = Unpooled.buffer();
-        try {
-            for (int i = 0; i < 32; i++) {
-                byteBuf.writeBytes(EMPTY_BIOME_DATA);
-            }
-
-            byteBuf.writeByte(0); // Border
-
-            EMPTY_CHUNK_DATA = new byte[byteBuf.readableBytes()];
-            byteBuf.readBytes(EMPTY_CHUNK_DATA);
-        } finally {
-            byteBuf.release();
-        }
     }
 
     public static int indexYZXtoXZY(int yzx) {
@@ -185,11 +168,32 @@ public class ChunkUtils {
     }
 
     public static void sendEmptyChunk(GeyserSession session, int chunkX, int chunkZ, boolean forceUpdate) {
+        BedrockDimension bedrockDimension = session.getChunkCache().getBedrockDimension();
+        int bedrockSubChunkCount = bedrockDimension.height() >> 4;
+
+        byte[] payload;
+
+        // Allocate output buffer
+        ByteBuf byteBuf = ByteBufAllocator.DEFAULT.buffer(ChunkUtils.EMPTY_BIOME_DATA.length * bedrockSubChunkCount + 1); // Consists only of biome data and border blocks
+        try {
+            byteBuf.writeBytes(EMPTY_BIOME_DATA);
+            for (int i = 1; i < bedrockSubChunkCount; i++) {
+                byteBuf.writeByte((127 << 1) | 1);
+            }
+
+            byteBuf.writeByte(0); // Border blocks - Edu edition only
+
+            payload = new byte[byteBuf.readableBytes()];
+            byteBuf.readBytes(payload);
+        } finally {
+            byteBuf.release();
+        }
+
         LevelChunkPacket data = new LevelChunkPacket();
         data.setChunkX(chunkX);
         data.setChunkZ(chunkZ);
         data.setSubChunksLength(0);
-        data.setData(EMPTY_CHUNK_DATA);
+        data.setData(payload);
         data.setCachingEnabled(false);
         session.sendUpstreamPacket(data);
 

core/src/main/java/org/geysermc/geyser/util/DimensionUtils.java

@@ -94,6 +94,8 @@ public class DimensionUtils {
         changeDimensionPacket.setPosition(pos);
         session.sendUpstreamPacket(changeDimensionPacket);
         session.setDimension(javaDimension);
+        session.setDimensionType(session.getDimensions().get(javaDimension));
+        ChunkUtils.loadDimension(session);
         player.setPosition(pos);
         session.setSpawned(false);
         session.setLastChunkPosition(null);