Merge branch 'extended-world-height'

README.md

@@ -39,8 +39,6 @@ Take a look [here](https://github.com/GeyserMC/Geyser/wiki/Setup) for how to set
 - Some Entity Flags
 - Structure block UI
 
-Extended height features can be "supported", but require additional work.
-
 ## What can't be fixed
 There are a few things Geyser is unable to support due to various differences between Minecraft Bedrock and Java. For a list of these limitations, see the [Current Limitations](https://github.com/GeyserMC/Geyser/wiki/Current-Limitations) page.
 

connector/pom.xml

@@ -130,7 +130,7 @@
         <dependency>
             <groupId>com.github.GeyserMC</groupId>
             <artifactId>MCProtocolLib</artifactId>
-            <version>6e318f5</version>
+            <version>e427237</version>
             <scope>compile</scope>
             <exclusions>
                 <exclusion>

connector/src/main/java/org/geysermc/connector/configuration/GeyserConfiguration.java

@@ -45,6 +45,8 @@ public interface GeyserConfiguration {
 
     Map<String, ? extends IUserAuthenticationInfo> getUserAuths();
 
+    boolean isExtendedWorldHeight();
+
     boolean isCommandSuggestions();
 
     @JsonIgnore

connector/src/main/java/org/geysermc/connector/configuration/GeyserJacksonConfiguration.java

@@ -55,6 +55,9 @@ public abstract class GeyserJacksonConfiguration implements GeyserConfiguration
     private BedrockConfiguration bedrock = new BedrockConfiguration();
     private RemoteConfiguration remote = new RemoteConfiguration();
 
+    @JsonProperty("extended-world-height")
+    private boolean extendedWorldHeight = false;
+
     @JsonProperty("floodgate-key-file")
     private String floodgateKeyFile = "public-key.pem";
 

connector/src/main/java/org/geysermc/connector/network/BedrockProtocol.java

@@ -28,6 +28,7 @@ package org.geysermc.connector.network;
 import com.nukkitx.protocol.bedrock.BedrockPacketCodec;
 import com.nukkitx.protocol.bedrock.v440.Bedrock_v440;
 import com.nukkitx.protocol.bedrock.v448.Bedrock_v448;
+import org.geysermc.connector.GeyserConnector;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -40,15 +41,17 @@ public class BedrockProtocol {
      * Default Bedrock codec that should act as a fallback. Should represent the latest available
      * release of the game that Geyser supports.
      */
-    public static final BedrockPacketCodec DEFAULT_BEDROCK_CODEC = Bedrock_v440.V440_CODEC;
+    public static final BedrockPacketCodec DEFAULT_BEDROCK_CODEC = Bedrock_v448.V448_CODEC;
     /**
      * A list of all supported Bedrock versions that can join Geyser
      */
     public static final List<BedrockPacketCodec> SUPPORTED_BEDROCK_CODECS = new ArrayList<>();
 
     static {
+        if (!GeyserConnector.getInstance().getConfig().isExtendedWorldHeight()) {
+            SUPPORTED_BEDROCK_CODECS.add(Bedrock_v440.V440_CODEC);
+        }
         SUPPORTED_BEDROCK_CODECS.add(DEFAULT_BEDROCK_CODEC);
-        SUPPORTED_BEDROCK_CODECS.add(Bedrock_v448.V448_CODEC);
     }
 
     /**

connector/src/main/java/org/geysermc/connector/network/UpstreamPacketHandler.java

@@ -137,6 +137,11 @@ public class UpstreamPacketHandler extends LoggingPacketHandler {
                     stackPacket.getExperiments().add(new ExperimentData("data_driven_items", true));
                 }
 
+                if (session.getConnector().getConfig().isExtendedWorldHeight()) {
+                    // Allow extended world height in the overworld to work
+                    stackPacket.getExperiments().add(new ExperimentData("caves_and_cliffs", true));
+                }
+
                 session.sendUpstreamPacket(stackPacket);
                 break;
 

connector/src/main/java/org/geysermc/connector/network/session/GeyserSession.java

@@ -1070,6 +1070,10 @@ public class GeyserSession implements CommandSender {
         settings.setServerAuthoritativeBlockBreaking(false);
         startGamePacket.setPlayerMovementSettings(settings);
 
+        if (connector.getConfig().isExtendedWorldHeight()) {
+            startGamePacket.getExperiments().add(new ExperimentData("caves_and_cliffs", true));
+        }
+
         upstream.sendPacket(startGamePacket);
     }
 
@@ -1191,11 +1195,7 @@ public class GeyserSession implements CommandSender {
      * @param packet the bedrock packet from the NukkitX protocol lib
      */
     public void sendUpstreamPacket(BedrockPacket packet) {
-        if (upstream != null) {
         upstream.sendPacket(packet);
-        } else {
-            connector.getLogger().debug("Tried to send upstream packet " + packet.getClass().getSimpleName() + " but the session was null");
-        }
     }
 
     /**
@@ -1204,11 +1204,7 @@ public class GeyserSession implements CommandSender {
      * @param packet the bedrock packet from the NukkitX protocol lib
      */
     public void sendUpstreamPacketImmediately(BedrockPacket packet) {
-        if (upstream != null) {
         upstream.sendPacketImmediately(packet);
-        } else {
-            connector.getLogger().debug("Tried to send upstream packet " + packet.getClass().getSimpleName() + " immediately but the session was null");
-        }
     }
 
     /**

connector/src/main/java/org/geysermc/connector/network/session/cache/ChunkCache.java

@@ -29,6 +29,7 @@ import com.github.steveice10.mc.protocol.data.game.chunk.Chunk;
 import com.github.steveice10.mc.protocol.data.game.chunk.Column;
 import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
 import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import lombok.Getter;
 import lombok.Setter;
 import org.geysermc.connector.network.session.GeyserSession;
 import org.geysermc.connector.network.translators.world.block.BlockStateValues;
@@ -44,6 +45,13 @@ public class ChunkCache {
     @Setter
     private int heightY;
 
+    /**
+     * Whether the Bedrock client believes they are in a world with a minimum of -64 and maximum of 320
+     */
+    @Getter
+    @Setter
+    private boolean isExtendedHeight = false;
+
     public ChunkCache(GeyserSession session) {
         this.cache = !session.getConnector().getWorldManager().hasOwnChunkCache(); // To prevent Spigot from initializing
         chunks = cache ? new Long2ObjectOpenHashMap<>() : null;
@@ -74,19 +82,19 @@ public class ChunkCache {
             return;
         }
 
-        if (y < minY || (y >> 4) > column.getChunks().length - 1) {
+        if (y < minY || ((y - minY) >> 4) > column.getChunks().length - 1) {
             // Y likely goes above or below the height limit of this world
             return;
         }
 
-        Chunk chunk = column.getChunks()[(y >> 4) - getChunkMinY()];
+        Chunk chunk = column.getChunks()[(y - minY) >> 4];
         if (chunk == null) {
             if (block != BlockStateValues.JAVA_AIR_ID) {
                 // A previously empty chunk, which is no longer empty as a block has been added to it
                 chunk = new Chunk();
                 // Fixes the chunk assuming that all blocks is the `block` variable we are updating. /shrug
                 chunk.getPalette().stateToId(BlockStateValues.JAVA_AIR_ID);
-                column.getChunks()[(y >> 4) - getChunkMinY()] = chunk;
+                column.getChunks()[(y - minY) >> 4] = chunk;
             } else {
                 // Nothing to update
                 return;
@@ -106,12 +114,12 @@ public class ChunkCache {
             return BlockStateValues.JAVA_AIR_ID;
         }
 
-        if (y < minY || (y >> 4) > column.getChunks().length - 1) {
+        if (y < minY || ((y - minY) >> 4) > column.getChunks().length - 1) {
             // Y likely goes above or below the height limit of this world
             return BlockStateValues.JAVA_AIR_ID;
         }
 
-        Chunk chunk = column.getChunks()[(y >> 4) - getChunkMinY()];
+        Chunk chunk = column.getChunks()[(y - minY) >> 4];
         if (chunk != null) {
             return chunk.get(x & 0xF, y & 0xF, z & 0xF);
         }

connector/src/main/java/org/geysermc/connector/network/translators/bedrock/entity/player/BedrockMovePlayerTranslator.java

@@ -33,6 +33,7 @@ import com.nukkitx.math.vector.Vector3d;
 import com.nukkitx.math.vector.Vector3f;
 import com.nukkitx.protocol.bedrock.packet.MoveEntityAbsolutePacket;
 import com.nukkitx.protocol.bedrock.packet.MovePlayerPacket;
+import org.geysermc.connector.GeyserConnector;
 import org.geysermc.connector.common.ChatColor;
 import org.geysermc.connector.entity.player.PlayerEntity;
 import org.geysermc.connector.entity.type.EntityType;
@@ -42,6 +43,14 @@ import org.geysermc.connector.network.translators.Translator;
 
 @Translator(packet = MovePlayerPacket.class)
 public class BedrockMovePlayerTranslator extends PacketTranslator<MovePlayerPacket> {
+    /* The upper and lower bounds to check for the void floor that only exists in Bedrock */
+    private static final int BEDROCK_OVERWORLD_VOID_FLOOR_UPPER_Y;
+    private static final int BEDROCK_OVERWORLD_VOID_FLOOR_LOWER_Y;
+
+    static {
+        BEDROCK_OVERWORLD_VOID_FLOOR_UPPER_Y = GeyserConnector.getInstance().getConfig().isExtendedWorldHeight() ? -104 : -40;
+        BEDROCK_OVERWORLD_VOID_FLOOR_LOWER_Y = BEDROCK_OVERWORLD_VOID_FLOOR_UPPER_Y + 2;
+    }
 
     @Override
     public void translate(MovePlayerPacket packet, GeyserSession session) {
@@ -108,10 +117,13 @@ public class BedrockMovePlayerTranslator extends PacketTranslator<MovePlayerPack
 
                         if (notMovingUp) {
                             int floorY = position.getFloorY();
-                            if (floorY <= -38 && floorY >= -40) {
-                                // Work around there being a floor at Y -40 and teleport the player below it
-                                // Moving from below Y -40 to above the void floor works fine
-                                //TODO: This will need to be changed for 1.17
+                            // If the client believes the world has extended height, then it also believes the void floor
+                            // still exists, just at a lower spot
+                            boolean extendedWorld = session.getChunkCache().isExtendedHeight();
+                            if (floorY <= (extendedWorld ? BEDROCK_OVERWORLD_VOID_FLOOR_LOWER_Y : -38)
+                                    && floorY >= (extendedWorld ? BEDROCK_OVERWORLD_VOID_FLOOR_UPPER_Y : -40)) {
+                                // Work around there being a floor at the bottom of the world and teleport the player below it
+                                // Moving from below to above the void floor works fine
                                 entity.setPosition(entity.getPosition().sub(0, 4f, 0));
                                 MovePlayerPacket movePlayerPacket = new MovePlayerPacket();
                                 movePlayerPacket.setRuntimeEntityId(entity.getGeyserId());

connector/src/main/java/org/geysermc/connector/network/translators/java/JavaJoinGameTranslator.java

@@ -55,8 +55,6 @@ public class JavaJoinGameTranslator extends PacketTranslator<ServerJoinGamePacke
         PlayerEntity entity = session.getPlayerEntity();
         entity.setEntityId(packet.getEntityId());
 
-        ChunkUtils.applyDimensionHeight(session, packet.getDimension());
-
         // If the player is already initialized and a join game packet is sent, they
         // are swapping servers
         String newDimension = DimensionUtils.getNewDimension(packet.getDimension());
@@ -113,5 +111,7 @@ public class JavaJoinGameTranslator extends PacketTranslator<ServerJoinGamePacke
         if (!newDimension.equals(session.getDimension())) {
             DimensionUtils.switchDimension(session, newDimension);
         }
+
+        ChunkUtils.applyDimensionHeight(session, packet.getDimension());
     }
 }

connector/src/main/java/org/geysermc/connector/network/translators/java/JavaRespawnTranslator.java

@@ -78,8 +78,6 @@ public class JavaRespawnTranslator extends PacketTranslator<ServerRespawnPacket>
             session.setThunder(false);
         }
 
-        ChunkUtils.applyDimensionHeight(session, packet.getDimension());
-
         String newDimension = DimensionUtils.getNewDimension(packet.getDimension());
         if (!session.getDimension().equals(newDimension) || !packet.getWorldName().equals(session.getWorldName())) {
             // Switching to a new world (based off the world name change); send a fake dimension change
@@ -93,5 +91,7 @@ public class JavaRespawnTranslator extends PacketTranslator<ServerRespawnPacket>
             session.setWorldName(packet.getWorldName());
             DimensionUtils.switchDimension(session, newDimension);
         }
+
+        ChunkUtils.applyDimensionHeight(session, packet.getDimension());
     }
 }

connector/src/main/java/org/geysermc/connector/network/translators/java/world/JavaChunkDataTranslator.java

@@ -37,14 +37,16 @@ import io.netty.buffer.ByteBufAllocator;
 import io.netty.buffer.ByteBufOutputStream;
 import org.geysermc.connector.GeyserConnector;
 import org.geysermc.connector.network.session.GeyserSession;
-import org.geysermc.connector.utils.BiomeUtils;
 import org.geysermc.connector.network.translators.PacketTranslator;
 import org.geysermc.connector.network.translators.Translator;
 import org.geysermc.connector.network.translators.world.chunk.ChunkSection;
+import org.geysermc.connector.utils.BiomeUtils;
 import org.geysermc.connector.utils.ChunkUtils;
 
 @Translator(packet = ServerChunkDataPacket.class)
 public class JavaChunkDataTranslator extends PacketTranslator<ServerChunkDataPacket> {
+    // Caves and cliffs supports 3D biomes by implementing a very similar palette system to blocks
+    private static final boolean NEW_BIOME_WRITE = GeyserConnector.getInstance().getConfig().isExtendedWorldHeight();
 
     @Override
     public void translate(ServerChunkDataPacket packet, GeyserSession session) {
@@ -79,7 +81,11 @@ public class JavaChunkDataTranslator extends PacketTranslator<ServerChunkDataPac
                     ChunkSection section = sections[i];
                     size += (section != null ? section : session.getBlockMappings().getEmptyChunkSection()).estimateNetworkSize();
                 }
-                size += 256; // Biomes
+                if (NEW_BIOME_WRITE) {
+                    size += ChunkUtils.EMPTY_CHUNK_DATA.length; // Consists only of biome data
+                } else {
+                    size += 256; // Biomes pre-1.18
+                }
                 size += 1; // Border blocks
                 size += 1; // Extra data length (always 0)
                 size += chunkData.getBlockEntities().length * 64; // Conservative estimate of 64 bytes per tile entity
@@ -93,7 +99,19 @@ public class JavaChunkDataTranslator extends PacketTranslator<ServerChunkDataPac
                         (section != null ? section : session.getBlockMappings().getEmptyChunkSection()).writeToNetwork(byteBuf);
                     }
 
+                    if (NEW_BIOME_WRITE) {
+                        for (int i = 0; i < sectionCount; i++) {
+                            BiomeUtils.toNewBedrockBiome(column.getBiomeData(), i).writeToNetwork(byteBuf);
+                        }
+
+                        // As of 1.17.10, Bedrock hardcodes to always read 32 biome sections
+                        int remainingEmptyBiomes = 32 - sectionCount;
+                        for (int i = 0; i < remainingEmptyBiomes; i++) {
+                            byteBuf.writeBytes(ChunkUtils.EMPTY_BIOME_DATA);
+                        }
+                    } else {
                         byteBuf.writeBytes(BiomeUtils.toBedrockBiome(column.getBiomeData())); // Biomes - 256 bytes
+                    }
                     byteBuf.writeByte(0); // Border blocks - Edu edition only
                     VarInts.writeUnsignedInt(byteBuf, 0); // extra data length, 0 for now
 

connector/src/main/java/org/geysermc/connector/registry/populator/BlockRegistryPopulator.java

@@ -53,8 +53,15 @@ import java.util.function.BiFunction;
 import java.util.zip.GZIPInputStream;
 
 public class BlockRegistryPopulator {
-    private static final ImmutableMap<String, BiFunction<String, NbtMapBuilder, String>> STATE_MAPPER = ImmutableMap.<String, BiFunction<String, NbtMapBuilder, String>>builder()
-            .put("1_17_0", (bedrockIdentifier, statesBuilder) -> {
+    private static final ImmutableMap<String, BiFunction<String, NbtMapBuilder, String>> STATE_MAPPER;
+
+    private static final Object2IntMap<String> PALETTE_VERSIONS;
+
+    static {
+        ImmutableMap.Builder<String, BiFunction<String, NbtMapBuilder, String>> stateMapperBuilder = ImmutableMap.<String, BiFunction<String, NbtMapBuilder, String>>builder()
+                .put("1_17_10", (bedrockIdentifier, statesBuilder) -> null);
+        if (!GeyserConnector.getInstance().getConfig().isExtendedWorldHeight()) {
+            stateMapperBuilder.put("1_17_0", (bedrockIdentifier, statesBuilder) -> {
                 if (bedrockIdentifier.contains("candle")) {
                     // Replace candles with sea pickles or cake
                     if (bedrockIdentifier.contains("cake")) {
@@ -68,16 +75,16 @@ public class BlockRegistryPopulator {
                     }
                 }
                 return null;
-            })
-            .put("1_17_10", (bedrockIdentifier, statesBuilder) -> null)
-            .build();
-
-    private static final Object2IntMap<String> PALETTE_VERSIONS = new Object2IntOpenHashMap<String>() {
-        {
-            put("1_17_0", Bedrock_v440.V440_CODEC.getProtocolVersion());
-            put("1_17_10", Bedrock_v448.V448_CODEC.getProtocolVersion());
+            });
+        }
+        STATE_MAPPER = stateMapperBuilder.build();
+
+        PALETTE_VERSIONS = new Object2IntOpenHashMap<>();
+        if (!GeyserConnector.getInstance().getConfig().isExtendedWorldHeight()) {
+            PALETTE_VERSIONS.put("1_17_0", Bedrock_v440.V440_CODEC.getProtocolVersion());
+        }
+        PALETTE_VERSIONS.put("1_17_10", Bedrock_v448.V448_CODEC.getProtocolVersion());
     }
-    };
 
     /**
      * Stores the raw blocks JSON until it is no longer needed.

connector/src/main/java/org/geysermc/connector/registry/populator/ItemRegistryPopulator.java

@@ -58,9 +58,14 @@ import java.io.InputStream;
 import java.util.*;
 
 public class ItemRegistryPopulator {
-    private static final Map<String, PaletteVersion> PALETTE_VERSIONS = new Object2ObjectOpenHashMap<String, PaletteVersion>(){
-        {
-            put("1_17_0", new PaletteVersion(Bedrock_v440.V440_CODEC.getProtocolVersion(), new Object2ObjectOpenHashMap<String, String>() {
+    private static final Map<String, PaletteVersion> PALETTE_VERSIONS;
+
+    static {
+        PALETTE_VERSIONS = new Object2ObjectOpenHashMap<>();
+        if (GeyserConnector.getInstance().getConfig().isExtendedWorldHeight()) {
+            PALETTE_VERSIONS.put("1_17_10.caves_and_cliffs", new PaletteVersion(Bedrock_v448.V448_CODEC.getProtocolVersion(), Collections.emptyMap()));
+        } else {
+            PALETTE_VERSIONS.put("1_17_0", new PaletteVersion(Bedrock_v440.V440_CODEC.getProtocolVersion(), new Object2ObjectOpenHashMap<String, String>() {
                 {
                     put("minecraft:candle", "minecraft:sea_pickle");
                     put("minecraft:white_candle", "minecraft:sea_pickle");
@@ -81,9 +86,9 @@ public class ItemRegistryPopulator {
                     put("minecraft:black_candle", "minecraft:sea_pickle");
                 }
             }));
-            put("1_17_10", new PaletteVersion(Bedrock_v448.V448_CODEC.getProtocolVersion(), Collections.emptyMap()));
+            PALETTE_VERSIONS.put("1_17_10", new PaletteVersion(Bedrock_v448.V448_CODEC.getProtocolVersion(), Collections.emptyMap()));
+        }
     }
-    };
 
     @Getter
     @AllArgsConstructor
@@ -230,10 +235,13 @@ public class ItemRegistryPopulator {
             Set<String> javaOnlyItems = new ObjectOpenHashSet<>();
             Collections.addAll(javaOnlyItems, "minecraft:spectral_arrow", "minecraft:debug_stick",
                     "minecraft:knowledge_book", "minecraft:tipped_arrow", "minecraft:trader_llama_spawn_egg",
-                    "minecraft:bundle", "minecraft:sculk_sensor");
+                    "minecraft:bundle");
             if (!usingFurnaceMinecart) {
                 javaOnlyItems.add("minecraft:furnace_minecart");
             }
+            if (!GeyserConnector.getInstance().getConfig().isExtendedWorldHeight()) {
+                javaOnlyItems.add("minecraft:sculk_sensor");
+            }
             // Java-only items for this version
             javaOnlyItems.addAll(palette.getValue().getAdditionalTranslatedItems().keySet());
 
@@ -246,6 +254,9 @@ public class ItemRegistryPopulator {
                     // This items has a mapping specifically for this version of the game
                     mappingItem = entry.getValue();
                 }
+                if (entry.getKey().equals("minecraft:sculk_sensor") && GeyserConnector.getInstance().getConfig().isExtendedWorldHeight()) {
+                    mappingItem.setBedrockIdentifier("minecraft:sculk_sensor");
+                }
 
                 if (usingFurnaceMinecart && entry.getKey().equals("minecraft:furnace_minecart")) {
                     javaFurnaceMinecartId = itemIndex;

connector/src/main/java/org/geysermc/connector/utils/BiomeUtils.java

@@ -25,6 +25,8 @@
 
 package org.geysermc.connector.utils;
 
+import org.geysermc.connector.network.translators.world.chunk.BlockStorage;
+
 import java.util.Arrays;
 
 // Based off of ProtocolSupport's LegacyBiomeData.java:
@@ -40,7 +42,7 @@ public class BiomeUtils {
         for (int y = 0; y < 16; y += 4) {
             for (int z = 0; z < 16; z += 4) {
                 for (int x = 0; x < 16; x += 4) {
-                    byte biomeId = biomeID(biomeData, x, y, z);
+                    byte biomeId = (byte) biomeID(biomeData, x, y, z);
                     int offset = ((z + (y / 4)) << 4) | x;
                     Arrays.fill(bedrockData, offset, offset + 4, biomeId);
                 }
@@ -49,7 +51,25 @@ public class BiomeUtils {
         return bedrockData;
     }
 
-    private static byte biomeID(int[] biomeData, int x, int y, int z) {
+    public static BlockStorage toNewBedrockBiome(int[] biomeData, int ySection) {
+        BlockStorage storage = new BlockStorage(0);
+        int blockY = ySection << 4;
+        int i = 0;
+        // Iterate over biomes like a chunk, grab the biome from Java, and add it to Bedrock's biome palette
+        // Might be able to be optimized by iterating over Java's biome data section?? Unsure.
+        for (int x = 0; x < 16; x++) {
+            for (int z = 0; z < 16; z++) {
+                for (int y = blockY; y < (blockY + 16); y++) {
+                    int biomeId = biomeID(biomeData, x, y, z);
+                    storage.setFullBlock(i, biomeId);
+                    i++;
+                }
+            }
+        }
+        return storage;
+    }
+
+    private static int biomeID(int[] biomeData, int x, int y, int z) {
         int biomeId = biomeData[((y >> 2) & 63) << 4 | ((z >> 2) & 3) << 2 | ((x >> 2) & 3)];
         if (biomeId == 0) {
             biomeId = 42; // Ocean
@@ -58,6 +78,6 @@ public class BiomeUtils {
         } else if (biomeId >= 170) { // Nether biomes. Dunno why it's like this :microjang:
             biomeId += 8;
         }
-        return (byte) biomeId;
+        return biomeId;
     }
 }

connector/src/main/java/org/geysermc/connector/utils/ChunkUtils.java

@@ -41,6 +41,8 @@ import com.nukkitx.nbt.NbtMap;
 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.Unpooled;
 import it.unimi.dsi.fastutil.ints.IntArrayList;
 import it.unimi.dsi.fastutil.ints.IntList;
 import lombok.Data;
@@ -72,10 +74,49 @@ public class ChunkUtils {
      * The minimum height Bedrock Edition will accept.
      */
     private static final int MINIMUM_ACCEPTED_HEIGHT = 0;
+    private static final int CAVES_AND_CLIFFS_MINIMUM_HEIGHT = -64;
+    private static final int MINIMUM_ACCEPTED_HEIGHT_OVERWORLD = GeyserConnector.getInstance().getConfig().isExtendedWorldHeight() ?
+            CAVES_AND_CLIFFS_MINIMUM_HEIGHT  : MINIMUM_ACCEPTED_HEIGHT;
     /**
-     * The maximum height Bedrock Edition will accept.
+     * The maximum chunk height Bedrock Edition will accept, from the lowest point to the highest.
      */
     private static final int MAXIMUM_ACCEPTED_HEIGHT = 256;
+    private static final int CAVES_AND_CLIFFS_MAXIMUM_HEIGHT = 384;
+    private static final int MAXIMUM_ACCEPTED_HEIGHT_OVERWORLD = GeyserConnector.getInstance().getConfig().isExtendedWorldHeight() ?
+            CAVES_AND_CLIFFS_MAXIMUM_HEIGHT : MAXIMUM_ACCEPTED_HEIGHT;
+
+    public static final byte[] EMPTY_CHUNK_DATA;
+    public static final byte[] EMPTY_BIOME_DATA;
+
+    static {
+        if (GeyserConnector.getInstance().getConfig().isExtendedWorldHeight()) {
+            ByteBuf byteBuf = Unpooled.buffer();
+            try {
+                BlockStorage blockStorage = new BlockStorage(0);
+                blockStorage.writeToNetwork(byteBuf);
+
+                EMPTY_BIOME_DATA = new byte[byteBuf.readableBytes()];
+                byteBuf.readBytes(EMPTY_BIOME_DATA);
+            } finally {
+                byteBuf.release();
+            }
+
+            byteBuf = Unpooled.buffer();
+            try {
+                for (int i = 0; i < 32; i++) {
+                    byteBuf.writeBytes(EMPTY_BIOME_DATA);
+                }
+
+                EMPTY_CHUNK_DATA = new byte[byteBuf.readableBytes()];
+                byteBuf.readBytes(EMPTY_CHUNK_DATA);
+            } finally {
+                byteBuf.release();
+            }
+        } else {
+            EMPTY_BIOME_DATA = null; // Unused
+            EMPTY_CHUNK_DATA = new byte[257]; // 256 bytes for biomes, one for borders
+        }
+    }
 
     private static int indexYZXtoXZY(int yzx) {
         return (yzx >> 8) | (yzx & 0x0F0) | ((yzx & 0x00F) << 8);
@@ -91,8 +132,10 @@ public class ChunkUtils {
         BitSet waterloggedPaletteIds = new BitSet();
         BitSet pistonOrFlowerPaletteIds = new BitSet();
 
+        boolean overworld = session.getChunkCache().isExtendedHeight();
+
         for (int sectionY = 0; sectionY < javaSections.length; sectionY++) {
-            if (yOffset < 0 && sectionY < -yOffset) {
+            if (yOffset < ((overworld ? MINIMUM_ACCEPTED_HEIGHT_OVERWORLD : MINIMUM_ACCEPTED_HEIGHT) >> 4) && sectionY < -yOffset) {
                 // Ignore this chunk since it goes below the accepted height limit
                 continue;
             }
@@ -128,7 +171,7 @@ public class ChunkUtils {
                         ));
                     }
                 }
-                sections[sectionY + yOffset] = section;
+                sections[sectionY + (yOffset - ((overworld ? MINIMUM_ACCEPTED_HEIGHT_OVERWORLD : MINIMUM_ACCEPTED_HEIGHT) >> 4))] = section;
                 continue;
             }
 
@@ -201,7 +244,7 @@ public class ChunkUtils {
                 layers = new BlockStorage[]{ layer0, new BlockStorage(BitArrayVersion.V1.createArray(BlockStorage.SIZE, layer1Data), layer1Palette) };
             }
 
-            sections[sectionY + yOffset] = new ChunkSection(layers);
+            sections[sectionY + (yOffset - ((overworld ? MINIMUM_ACCEPTED_HEIGHT_OVERWORLD : MINIMUM_ACCEPTED_HEIGHT) >> 4))] = new ChunkSection(layers);
         }
 
         CompoundTag[] blockEntities = column.getTileEntities();
@@ -383,7 +426,7 @@ public class ChunkUtils {
                 data.setChunkX(chunkX + x);
                 data.setChunkZ(chunkZ + z);
                 data.setSubChunksLength(0);
-                data.setData(new byte[0]);
+                data.setData(EMPTY_CHUNK_DATA);
                 data.setCachingEnabled(false);
                 session.sendUpstreamPacket(data);
 
@@ -400,7 +443,8 @@ public class ChunkUtils {
     }
 
     /**
-     * Process the minimum and maximum heights for this dimension
+     * Process the minimum and maximum heights for this dimension.
+     * This must be done after the player has switched dimensions so we know what their dimension is
      */
     public static void applyDimensionHeight(GeyserSession session, CompoundTag dimensionTag) {
         int minY = ((IntTag) dimensionTag.get("min_y")).getValue();
@@ -414,8 +458,25 @@ public class ChunkUtils {
             throw new RuntimeException("Maximum Y must be a multiple of 16!");
         }
 
-        if (minY < MINIMUM_ACCEPTED_HEIGHT || maxY > MAXIMUM_ACCEPTED_HEIGHT) {
-            session.getConnector().getLogger().warning(LanguageUtils.getLocaleStringLog("geyser.network.translator.chunk.out_of_bounds"));
+        int dimension = DimensionUtils.javaToBedrock(session.getDimension());
+        boolean extendedHeight = dimension == 0 && session.getConnector().getConfig().isExtendedWorldHeight();
+        session.getChunkCache().setExtendedHeight(extendedHeight);
+
+        // Yell in the console if the world height is too height in the current scenario
+        // The constraints change depending on if the player is in the overworld or not, and if experimental height is enabled
+        if (minY < (extendedHeight ? MINIMUM_ACCEPTED_HEIGHT_OVERWORLD : MINIMUM_ACCEPTED_HEIGHT)
+                || maxY > (extendedHeight ? MAXIMUM_ACCEPTED_HEIGHT_OVERWORLD : MAXIMUM_ACCEPTED_HEIGHT)) {
+            if (minY >= CAVES_AND_CLIFFS_MINIMUM_HEIGHT && maxY <= CAVES_AND_CLIFFS_MAXIMUM_HEIGHT && dimension == 0 && !session.getConnector().getConfig().isExtendedWorldHeight()) {
+                // This dimension uses heights that would be fixed by enabling the experimental toggle
+                session.getConnector().getLogger().warning(
+                        LanguageUtils.getLocaleStringLog("geyser.network.translator.chunk.out_of_bounds.caves_and_cliffs",
+                                "extended-world-height"));
+            } else {
+                session.getConnector().getLogger().warning(LanguageUtils.getLocaleStringLog("geyser.network.translator.chunk.out_of_bounds",
+                        extendedHeight ? MINIMUM_ACCEPTED_HEIGHT_OVERWORLD : MINIMUM_ACCEPTED_HEIGHT,
+                        extendedHeight ? MAXIMUM_ACCEPTED_HEIGHT_OVERWORLD : MAXIMUM_ACCEPTED_HEIGHT,
+                        session.getDimension()));
+            }
         }
 
         session.getChunkCache().setMinY(minY);

connector/src/main/resources/config.yml

@@ -57,6 +57,11 @@ remote:
   # This is designed to be used for forced hosts on proxies
   forward-hostname: false
 
+# Allows the overworld world height to be extended from 0 - 255 to -64 - 319. This option cannot be changed during a reload.
+# 1.17.0-1.17.2 Bedrock clients cannot connect with this option enabled.
+# Performance issues and/or additional bugs may occur for Bedrock clients as this is an experimental toggle on their end.
+extended-world-height: false
+
 # Floodgate uses encryption to ensure use from authorised sources.
 # This should point to the public key generated by Floodgate (BungeeCord, Spigot or Velocity)
 # You can ignore this when not using Floodgate.

connector/src/main/resources/languages

@@ -1 +1 @@
-Subproject commit fcc8f01e25e481c9c82f2ee9bff23111ec781dd7
+Subproject commit c8923b1f71c7f66621729be47dec7f911606c6a1