Paper/patches/removed/1.18/0361-Anti-Xray.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: stonar96 <minecraft.stonar96@gmail.com>
Date: Mon, 20 Aug 2018 03:03:58 +0200
Subject: [PATCH] Anti-Xray


diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 7a97a4a395f20680bc3b028586c9a17b84783d99..75f6915e2a2cc7328cf51b953edcc3ee6f9e7fbd 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -1,10 +1,12 @@
 package com.destroystokyo.paper;
 
+import java.util.Arrays;
 import java.util.List;
 
 import it.unimi.dsi.fastutil.objects.Reference2IntMap;
 import it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap;
 import net.minecraft.world.entity.MobCategory;
+import com.destroystokyo.paper.antixray.ChunkPacketBlockControllerAntiXray.EngineMode;
 import org.bukkit.Bukkit;
 import org.bukkit.configuration.file.YamlConfiguration;
 import org.spigotmc.SpigotWorldConfig;
@@ -518,5 +520,40 @@ public class PaperWorldConfig {
     private void lightQueueSize() {
         lightQueueSize = getInt("light-queue-size", lightQueueSize);
     }
+
+    public boolean antiXray;
+    public EngineMode engineMode;
+    public int maxBlockHeight;
+    public int updateRadius;
+    public boolean lavaObscures;
+    public boolean usePermission;
+    public List<String> hiddenBlocks;
+    public List<String> replacementBlocks;
+    private void antiXray() {
+        antiXray = getBoolean("anti-xray.enabled", false);
+        engineMode = EngineMode.getById(getInt("anti-xray.engine-mode", EngineMode.HIDE.getId()));
+        engineMode = engineMode == null ? EngineMode.HIDE : engineMode;
+        maxBlockHeight = getInt("anti-xray.max-block-height", 64);
+        updateRadius = getInt("anti-xray.update-radius", 2);
+        lavaObscures = getBoolean("anti-xray.lava-obscures", false);
+        usePermission = getBoolean("anti-xray.use-permission", false);
+        hiddenBlocks = getList("anti-xray.hidden-blocks", Arrays.asList("copper_ore", "deepslate_copper_ore", "gold_ore", "deepslate_gold_ore", "iron_ore", "deepslate_iron_ore",
+            "coal_ore", "deepslate_coal_ore", "lapis_ore", "deepslate_lapis_ore", "mossy_cobblestone", "obsidian", "chest", "diamond_ore", "deepslate_diamond_ore",
+            "redstone_ore", "deepslate_redstone_ore", "clay", "emerald_ore", "deepslate_emerald_ore", "ender_chest"));
+        replacementBlocks = getList("anti-xray.replacement-blocks", Arrays.asList("stone", "oak_planks", "deepslate"));
+        if (PaperConfig.version < 19) {
+            hiddenBlocks.remove("lit_redstone_ore");
+            int index = replacementBlocks.indexOf("planks");
+            if (index != -1) {
+                replacementBlocks.set(index, "oak_planks");
+            }
+            set("anti-xray.hidden-blocks", hiddenBlocks);
+            set("anti-xray.replacement-blocks", replacementBlocks);
+        }
+        log("Anti-Xray: " + (antiXray ? "enabled" : "disabled") + " / Engine Mode: " + engineMode.getDescription() + " / Up to " + ((maxBlockHeight >> 4) << 4) + " blocks / Update Radius: " + updateRadius);
+        if (antiXray && usePermission) {
+            Bukkit.getLogger().warning("You have enabled permission-based Anti-Xray checking - depending on your permission plugin, this may cause performance issues");
+        }
+    }
 }
 
diff --git a/src/main/java/com/destroystokyo/paper/antixray/BitStorageReader.java b/src/main/java/com/destroystokyo/paper/antixray/BitStorageReader.java
new file mode 100644
index 0000000000000000000000000000000000000000..e448c26327b5f6189c3c52e698cff66c8f9ad81a
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/BitStorageReader.java
@@ -0,0 +1,51 @@
+package com.destroystokyo.paper.antixray;
+
+public final class BitStorageReader {
+
+    private byte[] buffer;
+    private int bits;
+    private int mask;
+    private int longInBufferIndex;
+    private int bitInLongIndex;
+    private long current;
+
+    public void setBuffer(byte[] buffer) {
+        this.buffer = buffer;
+    }
+
+    public void setBits(int bits) {
+        this.bits = bits;
+        mask = (1 << bits) - 1;
+    }
+
+    public void setIndex(int index) {
+        longInBufferIndex = index;
+        bitInLongIndex = 0;
+        init();
+    }
+
+    private void init() {
+        if (buffer.length > longInBufferIndex + 7) {
+            current = ((((long) buffer[longInBufferIndex]) << 56)
+                | (((long) buffer[longInBufferIndex + 1] & 0xff) << 48)
+                | (((long) buffer[longInBufferIndex + 2] & 0xff) << 40)
+                | (((long) buffer[longInBufferIndex + 3] & 0xff) << 32)
+                | (((long) buffer[longInBufferIndex + 4] & 0xff) << 24)
+                | (((long) buffer[longInBufferIndex + 5] & 0xff) << 16)
+                | (((long) buffer[longInBufferIndex + 6] & 0xff) << 8)
+                | (((long) buffer[longInBufferIndex + 7] & 0xff)));
+        }
+    }
+
+    public int read() {
+        if (bitInLongIndex + bits > 64) {
+            bitInLongIndex = 0;
+            longInBufferIndex += 8;
+            init();
+        }
+
+        int value = (int) (current >>> bitInLongIndex) & mask;
+        bitInLongIndex += bits;
+        return value;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/antixray/BitStorageWriter.java b/src/main/java/com/destroystokyo/paper/antixray/BitStorageWriter.java
new file mode 100644
index 0000000000000000000000000000000000000000..e4540ea278f2dc871cb6a3cb8897559bfd65e134
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/BitStorageWriter.java
@@ -0,0 +1,79 @@
+package com.destroystokyo.paper.antixray;
+
+public final class BitStorageWriter {
+
+    private byte[] buffer;
+    private int bits;
+    private long mask;
+    private int longInBufferIndex;
+    private int bitInLongIndex;
+    private long current;
+    private boolean dirty;
+
+    public void setBuffer(byte[] buffer) {
+        this.buffer = buffer;
+    }
+
+    public void setBits(int bits) {
+        this.bits = bits;
+        mask = (1L << bits) - 1;
+    }
+
+    public void setIndex(int index) {
+        longInBufferIndex = index;
+        bitInLongIndex = 0;
+        init();
+    }
+
+    private void init() {
+        if (buffer.length > longInBufferIndex + 7) {
+            current = ((((long) buffer[longInBufferIndex]) << 56)
+                | (((long) buffer[longInBufferIndex + 1] & 0xff) << 48)
+                | (((long) buffer[longInBufferIndex + 2] & 0xff) << 40)
+                | (((long) buffer[longInBufferIndex + 3] & 0xff) << 32)
+                | (((long) buffer[longInBufferIndex + 4] & 0xff) << 24)
+                | (((long) buffer[longInBufferIndex + 5] & 0xff) << 16)
+                | (((long) buffer[longInBufferIndex + 6] & 0xff) << 8)
+                | (((long) buffer[longInBufferIndex + 7] & 0xff)));
+        }
+
+        dirty = false;
+    }
+
+    public void flush() {
+        if (dirty && buffer.length > longInBufferIndex + 7) {
+            buffer[longInBufferIndex] = (byte) (current >> 56 & 0xff);
+            buffer[longInBufferIndex + 1] = (byte) (current >> 48 & 0xff);
+            buffer[longInBufferIndex + 2] = (byte) (current >> 40 & 0xff);
+            buffer[longInBufferIndex + 3] = (byte) (current >> 32 & 0xff);
+            buffer[longInBufferIndex + 4] = (byte) (current >> 24 & 0xff);
+            buffer[longInBufferIndex + 5] = (byte) (current >> 16 & 0xff);
+            buffer[longInBufferIndex + 6] = (byte) (current >> 8 & 0xff);
+            buffer[longInBufferIndex + 7] = (byte) (current & 0xff);
+        }
+    }
+
+    public void write(int value) {
+        if (bitInLongIndex + bits > 64) {
+            flush();
+            bitInLongIndex = 0;
+            longInBufferIndex += 8;
+            init();
+        }
+
+        current = current & ~(mask << bitInLongIndex) | (value & mask) << bitInLongIndex;
+        dirty = true;
+        bitInLongIndex += bits;
+    }
+
+    public void skip() {
+        bitInLongIndex += bits;
+
+        if (bitInLongIndex > 64) {
+            flush();
+            bitInLongIndex = bits;
+            longInBufferIndex += 8;
+            init();
+        }
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockController.java b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockController.java
new file mode 100644
index 0000000000000000000000000000000000000000..280ece653cdda74e9c8fab4e9e5b3a952901cb01
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockController.java
@@ -0,0 +1,46 @@
+package com.destroystokyo.paper.antixray;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.network.protocol.game.ClientboundLevelChunkPacket;
+import net.minecraft.network.protocol.game.ServerboundPlayerActionPacket;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.ServerPlayerGameMode;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+
+public class ChunkPacketBlockController {
+
+    public static final ChunkPacketBlockController NO_OPERATION_INSTANCE = new ChunkPacketBlockController();
+
+    protected ChunkPacketBlockController() {
+
+    }
+
+    public BlockState[] getPresetBlockStates(Level level, ChunkAccess chunk, LevelChunkSection chunkSection, boolean initializeBlocks) {
+        return null;
+    }
+
+    public boolean shouldModify(ServerPlayer player, LevelChunk chunk) {
+        return false;
+    }
+
+    public ChunkPacketInfo<BlockState> getChunkPacketInfo(ClientboundLevelChunkPacket chunkPacket, LevelChunk chunk) {
+        return null;
+    }
+
+    public void modifyBlocks(ClientboundLevelChunkPacket chunkPacket, ChunkPacketInfo<BlockState> chunkPacketInfo) {
+        chunkPacket.setReady(true);
+    }
+
+    public void onBlockChange(Level level, BlockPos blockPos, BlockState newBlockState, BlockState oldBlockState, int flags, int maxUpdateDepth) {
+
+    }
+
+    public void onPlayerLeftClickBlock(ServerPlayerGameMode serverPlayerGameMode, BlockPos blockPos, ServerboundPlayerActionPacket.Action action, Direction direction, int worldHeight) {
+
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockControllerAntiXray.java b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockControllerAntiXray.java
new file mode 100644
index 0000000000000000000000000000000000000000..f9ed88082f1a58a0572acc22761fad4340185aeb
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockControllerAntiXray.java
@@ -0,0 +1,635 @@
+package com.destroystokyo.paper.antixray;
+
+import com.destroystokyo.paper.PaperWorldConfig;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.core.Registry;
+import net.minecraft.network.protocol.game.ClientboundLevelChunkPacketData;
+import net.minecraft.network.protocol.game.ServerboundPlayerActionPacket;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.ServerPlayerGameMode;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.EntityBlock;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.*;
+import org.bukkit.Bukkit;
+
+import java.util.*;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.function.IntSupplier;
+
+public final class ChunkPacketBlockControllerAntiXray extends ChunkPacketBlockController {
+
+    private final Executor executor;
+    private final EngineMode engineMode;
+    private final int maxBlockHeight;
+    private final int updateRadius;
+    private final boolean usePermission;
+    private final BlockState[] presetBlockStates;
+    private final BlockState[] presetBlockStatesFull;
+    private final BlockState[] presetBlockStatesStone;
+    private final BlockState[] presetBlockStatesNetherrack;
+    private final BlockState[] presetBlockStatesEndStone;
+    private final int[] presetBlockStateBitsGlobal;
+    private final int[] presetBlockStateBitsStoneGlobal;
+    private final int[] presetBlockStateBitsNetherrackGlobal;
+    private final int[] presetBlockStateBitsEndStoneGlobal;
+    private final boolean[] solidGlobal = new boolean[Block.BLOCK_STATE_REGISTRY.size()];
+    private final boolean[] obfuscateGlobal = new boolean[Block.BLOCK_STATE_REGISTRY.size()];
+    private final LevelChunkSection[] emptyNearbyChunkSections = {LevelChunk.EMPTY_SECTION, LevelChunk.EMPTY_SECTION, LevelChunk.EMPTY_SECTION, LevelChunk.EMPTY_SECTION};
+    private final int maxBlockHeightUpdatePosition;
+
+    public ChunkPacketBlockControllerAntiXray(Level level, Executor executor) {
+        this.executor = executor;
+        PaperWorldConfig paperWorldConfig = level.paperConfig;
+        engineMode = paperWorldConfig.engineMode;
+        maxBlockHeight = paperWorldConfig.maxBlockHeight >> 4 << 4;
+        updateRadius = paperWorldConfig.updateRadius;
+        usePermission = paperWorldConfig.usePermission;
+        List<String> toObfuscate;
+
+        if (engineMode == EngineMode.HIDE) {
+            toObfuscate = paperWorldConfig.hiddenBlocks;
+            presetBlockStates = null;
+            presetBlockStatesFull = null;
+            presetBlockStatesStone = new BlockState[]{Blocks.STONE.defaultBlockState()};
+            presetBlockStatesNetherrack = new BlockState[]{Blocks.NETHERRACK.defaultBlockState()};
+            presetBlockStatesEndStone = new BlockState[]{Blocks.END_STONE.defaultBlockState()};
+            presetBlockStateBitsGlobal = null;
+            presetBlockStateBitsStoneGlobal = new int[]{LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(Blocks.STONE.defaultBlockState())};
+            presetBlockStateBitsNetherrackGlobal = new int[]{LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(Blocks.NETHERRACK.defaultBlockState())};
+            presetBlockStateBitsEndStoneGlobal = new int[]{LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(Blocks.END_STONE.defaultBlockState())};
+        } else {
+            toObfuscate = new ArrayList<>(paperWorldConfig.replacementBlocks);
+            List<BlockState> presetBlockStateList = new LinkedList<>();
+
+            for (String id : paperWorldConfig.hiddenBlocks) {
+                Block block = Registry.BLOCK.getOptional(new ResourceLocation(id)).orElse(null);
+
+                if (block != null && !(block instanceof EntityBlock)) {
+                    toObfuscate.add(id);
+                    presetBlockStateList.add(block.defaultBlockState());
+                }
+            }
+
+            // The doc of the LinkedHashSet(Collection<? extends E>) constructor doesn't specify that the insertion order is the predictable iteration order of the specified Collection, although it is in the implementation
+            Set<BlockState> presetBlockStateSet = new LinkedHashSet<>();
+            // Therefore addAll(Collection<? extends E>) is used, which guarantees this order in the doc
+            presetBlockStateSet.addAll(presetBlockStateList);
+            presetBlockStates = presetBlockStateSet.isEmpty() ? new BlockState[]{Blocks.DIAMOND_ORE.defaultBlockState()} : presetBlockStateSet.toArray(new BlockState[0]);
+            presetBlockStatesFull = presetBlockStateSet.isEmpty() ? new BlockState[]{Blocks.DIAMOND_ORE.defaultBlockState()} : presetBlockStateList.toArray(new BlockState[0]);
+            presetBlockStatesStone = null;
+            presetBlockStatesNetherrack = null;
+            presetBlockStatesEndStone = null;
+            presetBlockStateBitsGlobal = new int[presetBlockStatesFull.length];
+
+            for (int i = 0; i < presetBlockStatesFull.length; i++) {
+                presetBlockStateBitsGlobal[i] = LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(presetBlockStatesFull[i]);
+            }
+
+            presetBlockStateBitsStoneGlobal = null;
+            presetBlockStateBitsNetherrackGlobal = null;
+            presetBlockStateBitsEndStoneGlobal = null;
+        }
+
+        for (String id : toObfuscate) {
+            Block block = Registry.BLOCK.getOptional(new ResourceLocation(id)).orElse(null);
+
+            // Don't obfuscate air because air causes unnecessary block updates and causes block updates to fail in the void
+            if (block != null && !block.defaultBlockState().isAir()) {
+                // Replace all block states of a specified block
+                for (BlockState blockState : block.getStateDefinition().getPossibleStates()) {
+                    obfuscateGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(blockState)] = true;
+                }
+            }
+        }
+
+        EmptyLevelChunk emptyChunk = new EmptyLevelChunk(level, new ChunkPos(0, 0));
+        BlockPos zeroPos = new BlockPos(0, 0, 0);
+
+        for (int i = 0; i < solidGlobal.length; i++) {
+            BlockState blockState = LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.valueFor(i);
+
+            if (blockState != null) {
+                solidGlobal[i] = blockState.isRedstoneConductor(emptyChunk, zeroPos)
+                    && blockState.getBlock() != Blocks.SPAWNER && blockState.getBlock() != Blocks.BARRIER && blockState.getBlock() != Blocks.SHULKER_BOX && blockState.getBlock() != Blocks.SLIME_BLOCK || paperWorldConfig.lavaObscures && blockState == Blocks.LAVA.defaultBlockState();
+                // Comparing blockState == Blocks.LAVA.defaultBlockState() instead of blockState.getBlock() == Blocks.LAVA ensures that only "stationary lava" is used
+                // shulker box checks TE.
+            }
+        }
+
+        maxBlockHeightUpdatePosition = maxBlockHeight + updateRadius - 1;
+    }
+
+    private int getPresetBlockStatesFullLength() {
+        return engineMode == EngineMode.HIDE ? 1 : presetBlockStatesFull.length;
+    }
+
+    @Override
+    public BlockState[] getPresetBlockStates(Level level, ChunkAccess chunk, LevelChunkSection chunkSection, boolean initializeBlocks) {
+        // Return the block states to be added to the paletted containers so that they can be used for obfuscation
+        if (chunkSection.bottomBlockY() < maxBlockHeight) {
+            if (engineMode == EngineMode.HIDE) {
+                return switch (level.getWorld().getEnvironment()) {
+                    case NETHER -> presetBlockStatesNetherrack;
+                    case THE_END -> presetBlockStatesEndStone;
+                    default -> presetBlockStatesStone;
+                };
+            }
+
+            return presetBlockStates;
+        }
+
+        return null;
+    }
+
+    @Override
+    public boolean shouldModify(ServerPlayer player, LevelChunk chunk) {
+        return !usePermission || !player.getBukkitEntity().hasPermission("paper.antixray.bypass");
+    }
+
+    @Override
+    public ChunkPacketInfoAntiXray getChunkPacketInfo(ClientboundLevelChunkPacketData chunkPacket, LevelChunk chunk) {
+        // Return a new instance to collect data and objects in the right state while creating the chunk packet for thread safe access later
+        return new ChunkPacketInfoAntiXray(chunkPacket, chunk, this);
+    }
+
+    @Override
+    public void modifyBlocks(ClientboundLevelChunkPacket chunkPacket, ChunkPacketInfo<BlockState> chunkPacketInfo) {
+        if (!(chunkPacketInfo instanceof ChunkPacketInfoAntiXray)) {
+            chunkPacket.setReady(true);
+            return;
+        }
+
+        if (!Bukkit.isPrimaryThread()) {
+            // Plugins?
+            MinecraftServer.getServer().scheduleOnMain(() -> modifyBlocks(chunkPacket, chunkPacketInfo));
+            return;
+        }
+
+        LevelChunk chunk = chunkPacketInfo.getChunk();
+        int x = chunk.getPos().x;
+        int z = chunk.getPos().z;
+        Level level = chunk.level;
+        ((ChunkPacketInfoAntiXray) chunkPacketInfo).setNearbyChunks(level.getChunkIfLoaded(x - 1, z), level.getChunkIfLoaded(x + 1, z), level.getChunkIfLoaded(x, z - 1), level.getChunkIfLoaded(x, z + 1));
+        executor.execute((Runnable) chunkPacketInfo);
+    }
+
+    // Actually these fields should be variables inside the obfuscate method but in sync mode or with SingleThreadExecutor in async mode it's okay (even without ThreadLocal)
+    // If an ExecutorService with multiple threads is used, ThreadLocal must be used here
+    private final ThreadLocal<int[]> presetBlockStateBits = ThreadLocal.withInitial(() -> new int[getPresetBlockStatesFullLength()]);
+    private static final ThreadLocal<boolean[]> solid = ThreadLocal.withInitial(() -> new boolean[Block.BLOCK_STATE_REGISTRY.size()]);
+    private static final ThreadLocal<boolean[]> obfuscate = ThreadLocal.withInitial(() -> new boolean[Block.BLOCK_STATE_REGISTRY.size()]);
+    // These boolean arrays represent chunk layers, true means don't obfuscate, false means obfuscate
+    private static final ThreadLocal<boolean[][]> current = ThreadLocal.withInitial(() -> new boolean[16][16]);
+    private static final ThreadLocal<boolean[][]> next = ThreadLocal.withInitial(() -> new boolean[16][16]);
+    private static final ThreadLocal<boolean[][]> nextNext = ThreadLocal.withInitial(() -> new boolean[16][16]);
+
+    public void obfuscate(ChunkPacketInfoAntiXray chunkPacketInfoAntiXray) {
+        int[] presetBlockStateBits = this.presetBlockStateBits.get();
+        boolean[] solid = ChunkPacketBlockControllerAntiXray.solid.get();
+        boolean[] obfuscate = ChunkPacketBlockControllerAntiXray.obfuscate.get();
+        boolean[][] current = ChunkPacketBlockControllerAntiXray.current.get();
+        boolean[][] next = ChunkPacketBlockControllerAntiXray.next.get();
+        boolean[][] nextNext = ChunkPacketBlockControllerAntiXray.nextNext.get();
+        // bitStorageReader, bitStorageWriter and nearbyChunkSections could also be reused (with ThreadLocal if necessary) but it's not worth it
+        BitStorageReader bitStorageReader = new BitStorageReader();
+        BitStorageWriter bitStorageWriter = new BitStorageWriter();
+        LevelChunkSection[] nearbyChunkSections = new LevelChunkSection[4];
+        LevelChunk chunk = chunkPacketInfoAntiXray.getChunk();
+        Level level = chunk.level;
+        int maxChunkSectionIndex = Math.min((maxBlockHeight >> 4) - chunk.getMinSection(), chunk.getSectionsCount() - 1);
+        boolean[] solidTemp = null;
+        boolean[] obfuscateTemp = null;
+        bitStorageReader.setBuffer(chunkPacketInfoAntiXray.getBuffer());
+        bitStorageWriter.setBuffer(chunkPacketInfoAntiXray.getBuffer());
+        int numberOfBlocks = presetBlockStateBits.length;
+        // Keep the lambda expressions as simple as possible. They are used very frequently.
+        IntSupplier random = numberOfBlocks == 1 ? (() -> 0) : new IntSupplier() {
+            private int state;
+
+            {
+                while ((state = ThreadLocalRandom.current().nextInt()) == 0) ;
+            }
+
+            @Override
+            public int getAsInt() {
+                // https://en.wikipedia.org/wiki/Xorshift
+                state ^= state << 13;
+                state ^= state >>> 17;
+                state ^= state << 5;
+                // https://www.pcg-random.org/posts/bounded-rands.html
+                return (int) ((Integer.toUnsignedLong(state) * numberOfBlocks) >>> 32);
+            }
+        };
+
+        for (int chunkSectionIndex = 0; chunkSectionIndex <= maxChunkSectionIndex; chunkSectionIndex++) {
+            if (chunkPacketInfoAntiXray.isWritten(chunkSectionIndex) && chunkPacketInfoAntiXray.getPresetValues(chunkSectionIndex) != null) {
+                int[] presetBlockStateBitsTemp;
+
+                if (chunkPacketInfoAntiXray.getPalette(chunkSectionIndex) == LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE) {
+                    if (engineMode == EngineMode.HIDE) {
+                        presetBlockStateBitsTemp = switch (level.getWorld().getEnvironment()) {
+                            case NETHER -> presetBlockStateBitsNetherrackGlobal;
+                            case THE_END -> presetBlockStateBitsEndStoneGlobal;
+                            default -> presetBlockStateBitsStoneGlobal;
+                        };
+                    } else {
+                        presetBlockStateBitsTemp = presetBlockStateBitsGlobal;
+                    }
+                } else {
+                    // If it's presetBlockStates, use this.presetBlockStatesFull instead
+                    BlockState[] presetBlockStatesFull = chunkPacketInfoAntiXray.getPresetValues(chunkSectionIndex) == presetBlockStates ? this.presetBlockStatesFull : chunkPacketInfoAntiXray.getPresetValues(chunkSectionIndex);
+                    presetBlockStateBitsTemp = presetBlockStateBits;
+
+                    for (int i = 0; i < presetBlockStateBitsTemp.length; i++) {
+                        presetBlockStateBitsTemp[i] = chunkPacketInfoAntiXray.getPalette(chunkSectionIndex).idFor(presetBlockStatesFull[i]);
+                    }
+                }
+
+                bitStorageWriter.setIndex(chunkPacketInfoAntiXray.getIndex(chunkSectionIndex));
+
+                // Check if the chunk section below was not obfuscated
+                if (chunkSectionIndex == 0 || !chunkPacketInfoAntiXray.isWritten(chunkSectionIndex - 1) || chunkPacketInfoAntiXray.getPresetValues(chunkSectionIndex - 1) == null) {
+                    // If so, initialize some stuff
+                    bitStorageReader.setBits(chunkPacketInfoAntiXray.getBits(chunkSectionIndex));
+                    bitStorageReader.setIndex(chunkPacketInfoAntiXray.getIndex(chunkSectionIndex));
+                    solidTemp = readPalette(chunkPacketInfoAntiXray.getPalette(chunkSectionIndex), solid, solidGlobal);
+                    obfuscateTemp = readPalette(chunkPacketInfoAntiXray.getPalette(chunkSectionIndex), obfuscate, obfuscateGlobal);
+                    // Read the blocks of the upper layer of the chunk section below if it exists
+                    LevelChunkSection belowChunkSection = null;
+                    boolean skipFirstLayer = chunkSectionIndex == 0 || (belowChunkSection = chunk.getSections()[chunkSectionIndex - 1]) == LevelChunk.EMPTY_SECTION;
+
+                    for (int z = 0; z < 16; z++) {
+                        for (int x = 0; x < 16; x++) {
+                            current[z][x] = true;
+                            next[z][x] = skipFirstLayer || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(belowChunkSection.getBlockState(x, 15, z))];
+                        }
+                    }
+
+                    // Abuse the obfuscateLayer method to read the blocks of the first layer of the current chunk section
+                    bitStorageWriter.setBits(0);
+                    obfuscateLayer(-1, bitStorageReader, bitStorageWriter, solidTemp, obfuscateTemp, presetBlockStateBitsTemp, current, next, nextNext, emptyNearbyChunkSections, random);
+                }
+
+                bitStorageWriter.setBits(chunkPacketInfoAntiXray.getBits(chunkSectionIndex));
+                nearbyChunkSections[0] = chunkPacketInfoAntiXray.getNearbyChunks()[0] == null ? LevelChunk.EMPTY_SECTION : chunkPacketInfoAntiXray.getNearbyChunks()[0].getSections()[chunkSectionIndex];
+                nearbyChunkSections[1] = chunkPacketInfoAntiXray.getNearbyChunks()[1] == null ? LevelChunk.EMPTY_SECTION : chunkPacketInfoAntiXray.getNearbyChunks()[1].getSections()[chunkSectionIndex];
+                nearbyChunkSections[2] = chunkPacketInfoAntiXray.getNearbyChunks()[2] == null ? LevelChunk.EMPTY_SECTION : chunkPacketInfoAntiXray.getNearbyChunks()[2].getSections()[chunkSectionIndex];
+                nearbyChunkSections[3] = chunkPacketInfoAntiXray.getNearbyChunks()[3] == null ? LevelChunk.EMPTY_SECTION : chunkPacketInfoAntiXray.getNearbyChunks()[3].getSections()[chunkSectionIndex];
+
+                // Obfuscate all layers of the current chunk section except the upper one
+                for (int y = 0; y < 15; y++) {
+                    boolean[][] temp = current;
+                    current = next;
+                    next = nextNext;
+                    nextNext = temp;
+                    obfuscateLayer(y, bitStorageReader, bitStorageWriter, solidTemp, obfuscateTemp, presetBlockStateBitsTemp, current, next, nextNext, nearbyChunkSections, random);
+                }
+
+                // Check if the chunk section above doesn't need obfuscation
+                if (chunkSectionIndex == maxChunkSectionIndex || !chunkPacketInfoAntiXray.isWritten(chunkSectionIndex + 1) || chunkPacketInfoAntiXray.getPresetValues(chunkSectionIndex + 1) == null) {
+                    // If so, obfuscate the upper layer of the current chunk section by reading blocks of the first layer from the chunk section above if it exists
+                    LevelChunkSection aboveChunkSection;
+
+                    if (chunkSectionIndex != chunk.getSectionsCount() - 1 && (aboveChunkSection = chunk.getSections()[chunkSectionIndex + 1]) != LevelChunk.EMPTY_SECTION) {
+                        boolean[][] temp = current;
+                        current = next;
+                        next = nextNext;
+                        nextNext = temp;
+
+                        for (int z = 0; z < 16; z++) {
+                            for (int x = 0; x < 16; x++) {
+                                if (!solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(aboveChunkSection.getBlockState(x, 0, z))]) {
+                                    current[z][x] = true;
+                                }
+                            }
+                        }
+
+                        // There is nothing to read anymore
+                        bitStorageReader.setBits(0);
+                        solid[0] = true;
+                        obfuscateLayer(15, bitStorageReader, bitStorageWriter, solid, obfuscateTemp, presetBlockStateBitsTemp, current, next, nextNext, nearbyChunkSections, random);
+                    }
+                } else {
+                    // If not, initialize the reader and other stuff for the chunk section above to obfuscate the upper layer of the current chunk section
+                    bitStorageReader.setBits(chunkPacketInfoAntiXray.getBits(chunkSectionIndex + 1));
+                    bitStorageReader.setIndex(chunkPacketInfoAntiXray.getIndex(chunkSectionIndex + 1));
+                    solidTemp = readPalette(chunkPacketInfoAntiXray.getPalette(chunkSectionIndex + 1), solid, solidGlobal);
+                    obfuscateTemp = readPalette(chunkPacketInfoAntiXray.getPalette(chunkSectionIndex + 1), obfuscate, obfuscateGlobal);
+                    boolean[][] temp = current;
+                    current = next;
+                    next = nextNext;
+                    nextNext = temp;
+                    obfuscateLayer(15, bitStorageReader, bitStorageWriter, solidTemp, obfuscateTemp, presetBlockStateBitsTemp, current, next, nextNext, nearbyChunkSections, random);
+                }
+
+                bitStorageWriter.flush();
+            }
+        }
+
+        chunkPacketInfoAntiXray.getChunkPacket().setReady(true);
+    }
+
+    private void obfuscateLayer(int y, BitStorageReader bitStorageReader, BitStorageWriter bitStorageWriter, boolean[] solid, boolean[] obfuscate, int[] presetBlockStateBits, boolean[][] current, boolean[][] next, boolean[][] nextNext, LevelChunkSection[] nearbyChunkSections, IntSupplier random) {
+        // First block of first line
+        int bits = bitStorageReader.read();
+
+        if (nextNext[0][0] = !solid[bits]) {
+            bitStorageWriter.skip();
+            next[0][1] = true;
+            next[1][0] = true;
+        } else {
+            if (current[0][0] || nearbyChunkSections[2] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[2].getBlockState(0, y, 15))] || nearbyChunkSections[0] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[0].getBlockState(15, y, 0))]) {
+                bitStorageWriter.skip();
+            } else {
+                bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+            }
+        }
+
+        if (!obfuscate[bits]) {
+            next[0][0] = true;
+        }
+
+        // First line
+        for (int x = 1; x < 15; x++) {
+            bits = bitStorageReader.read();
+
+            if (nextNext[0][x] = !solid[bits]) {
+                bitStorageWriter.skip();
+                next[0][x - 1] = true;
+                next[0][x + 1] = true;
+                next[1][x] = true;
+            } else {
+                if (current[0][x] || nearbyChunkSections[2] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[2].getBlockState(x, y, 15))]) {
+                    bitStorageWriter.skip();
+                } else {
+                    bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+                }
+            }
+
+            if (!obfuscate[bits]) {
+                next[0][x] = true;
+            }
+        }
+
+        // Last block of first line
+        bits = bitStorageReader.read();
+
+        if (nextNext[0][15] = !solid[bits]) {
+            bitStorageWriter.skip();
+            next[0][14] = true;
+            next[1][15] = true;
+        } else {
+            if (current[0][15] || nearbyChunkSections[2] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[2].getBlockState(15, y, 15))] || nearbyChunkSections[1] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[1].getBlockState(0, y, 0))]) {
+                bitStorageWriter.skip();
+            } else {
+                bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+            }
+        }
+
+        if (!obfuscate[bits]) {
+            next[0][15] = true;
+        }
+
+        // All inner lines
+        for (int z = 1; z < 15; z++) {
+            // First block
+            bits = bitStorageReader.read();
+
+            if (nextNext[z][0] = !solid[bits]) {
+                bitStorageWriter.skip();
+                next[z][1] = true;
+                next[z - 1][0] = true;
+                next[z + 1][0] = true;
+            } else {
+                if (current[z][0] || nearbyChunkSections[0] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[0].getBlockState(15, y, z))]) {
+                    bitStorageWriter.skip();
+                } else {
+                    bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+                }
+            }
+
+            if (!obfuscate[bits]) {
+                next[z][0] = true;
+            }
+
+            // All inner blocks
+            for (int x = 1; x < 15; x++) {
+                bits = bitStorageReader.read();
+
+                if (nextNext[z][x] = !solid[bits]) {
+                    bitStorageWriter.skip();
+                    next[z][x - 1] = true;
+                    next[z][x + 1] = true;
+                    next[z - 1][x] = true;
+                    next[z + 1][x] = true;
+                } else {
+                    if (current[z][x]) {
+                        bitStorageWriter.skip();
+                    } else {
+                        bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+                    }
+                }
+
+                if (!obfuscate[bits]) {
+                    next[z][x] = true;
+                }
+            }
+
+            // Last block
+            bits = bitStorageReader.read();
+
+            if (nextNext[z][15] = !solid[bits]) {
+                bitStorageWriter.skip();
+                next[z][14] = true;
+                next[z - 1][15] = true;
+                next[z + 1][15] = true;
+            } else {
+                if (current[z][15] || nearbyChunkSections[1] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[1].getBlockState(0, y, z))]) {
+                    bitStorageWriter.skip();
+                } else {
+                    bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+                }
+            }
+
+            if (!obfuscate[bits]) {
+                next[z][15] = true;
+            }
+        }
+
+        // First block of last line
+        bits = bitStorageReader.read();
+
+        if (nextNext[15][0] = !solid[bits]) {
+            bitStorageWriter.skip();
+            next[15][1] = true;
+            next[14][0] = true;
+        } else {
+            if (current[15][0] || nearbyChunkSections[3] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[3].getBlockState(0, y, 0))] || nearbyChunkSections[0] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[0].getBlockState(15, y, 15))]) {
+                bitStorageWriter.skip();
+            } else {
+                bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+            }
+        }
+
+        if (!obfuscate[bits]) {
+            next[15][0] = true;
+        }
+
+        // Last line
+        for (int x = 1; x < 15; x++) {
+            bits = bitStorageReader.read();
+
+            if (nextNext[15][x] = !solid[bits]) {
+                bitStorageWriter.skip();
+                next[15][x - 1] = true;
+                next[15][x + 1] = true;
+                next[14][x] = true;
+            } else {
+                if (current[15][x] || nearbyChunkSections[3] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[3].getBlockState(x, y, 0))]) {
+                    bitStorageWriter.skip();
+                } else {
+                    bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+                }
+            }
+
+            if (!obfuscate[bits]) {
+                next[15][x] = true;
+            }
+        }
+
+        // Last block of last line
+        bits = bitStorageReader.read();
+
+        if (nextNext[15][15] = !solid[bits]) {
+            bitStorageWriter.skip();
+            next[15][14] = true;
+            next[14][15] = true;
+        } else {
+            if (current[15][15] || nearbyChunkSections[3] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[3].getBlockState(15, y, 0))] || nearbyChunkSections[1] == LevelChunk.EMPTY_SECTION || !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(nearbyChunkSections[1].getBlockState(0, y, 15))]) {
+                bitStorageWriter.skip();
+            } else {
+                bitStorageWriter.write(presetBlockStateBits[random.getAsInt()]);
+            }
+        }
+
+        if (!obfuscate[bits]) {
+            next[15][15] = true;
+        }
+    }
+
+    private boolean[] readPalette(Palette<BlockState> palette, boolean[] temp, boolean[] global) {
+        if (palette == LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE) {
+            return global;
+        }
+
+        BlockState blockState;
+
+        for (int i = 0; (blockState = palette.valueFor(i)) != null; i++) {
+            temp[i] = global[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(blockState)];
+        }
+
+        return temp;
+    }
+
+    @Override
+    public void onBlockChange(Level level, BlockPos blockPos, BlockState newBlockState, BlockState oldBlockState, int flags, int maxUpdateDepth) {
+        if (oldBlockState != null && solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(oldBlockState)] && !solidGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(newBlockState)] && blockPos.getY() <= maxBlockHeightUpdatePosition) {
+            updateNearbyBlocks(level, blockPos);
+        }
+    }
+
+    @Override
+    public void onPlayerLeftClickBlock(ServerPlayerGameMode serverPlayerGameMode, BlockPos blockPos, ServerboundPlayerActionPacket.Action action, Direction direction, int worldHeight) {
+        if (blockPos.getY() <= maxBlockHeightUpdatePosition) {
+            updateNearbyBlocks(serverPlayerGameMode.level, blockPos);
+        }
+    }
+
+    private void updateNearbyBlocks(Level level, BlockPos blockPos) {
+        if (updateRadius >= 2) {
+            BlockPos temp = blockPos.west();
+            updateBlock(level, temp);
+            updateBlock(level, temp.west());
+            updateBlock(level, temp.below());
+            updateBlock(level, temp.above());
+            updateBlock(level, temp.north());
+            updateBlock(level, temp.south());
+            updateBlock(level, temp = blockPos.east());
+            updateBlock(level, temp.east());
+            updateBlock(level, temp.below());
+            updateBlock(level, temp.above());
+            updateBlock(level, temp.north());
+            updateBlock(level, temp.south());
+            updateBlock(level, temp = blockPos.below());
+            updateBlock(level, temp.below());
+            updateBlock(level, temp.north());
+            updateBlock(level, temp.south());
+            updateBlock(level, temp = blockPos.above());
+            updateBlock(level, temp.above());
+            updateBlock(level, temp.north());
+            updateBlock(level, temp.south());
+            updateBlock(level, temp = blockPos.north());
+            updateBlock(level, temp.north());
+            updateBlock(level, temp = blockPos.south());
+            updateBlock(level, temp.south());
+        } else if (updateRadius == 1) {
+            updateBlock(level, blockPos.west());
+            updateBlock(level, blockPos.east());
+            updateBlock(level, blockPos.below());
+            updateBlock(level, blockPos.above());
+            updateBlock(level, blockPos.north());
+            updateBlock(level, blockPos.south());
+        } else {
+            // Do nothing if updateRadius <= 0 (test mode)
+        }
+    }
+
+    private void updateBlock(Level level, BlockPos blockPos) {
+        BlockState blockState = level.getTypeIfLoaded(blockPos);
+
+        if (blockState != null && obfuscateGlobal[LevelChunkSection.GLOBAL_BLOCKSTATE_PALETTE.idFor(blockState)]) {
+            ((ServerLevel) level).getChunkSource().blockChanged(blockPos);
+        }
+    }
+
+    public enum EngineMode {
+
+        HIDE(1, "hide ores"),
+        OBFUSCATE(2, "obfuscate");
+
+        private final int id;
+        private final String description;
+
+        EngineMode(int id, String description) {
+            this.id = id;
+            this.description = description;
+        }
+
+        public static EngineMode getById(int id) {
+            for (EngineMode engineMode : values()) {
+                if (engineMode.id == id) {
+                    return engineMode;
+                }
+            }
+
+            return null;
+        }
+
+        public int getId() {
+            return id;
+        }
+
+        public String getDescription() {
+            return description;
+        }
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfo.java b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfo.java
new file mode 100644
index 0000000000000000000000000000000000000000..351ab20ba506cca55ee198f06346bad8b1593d0a
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfo.java
@@ -0,0 +1,80 @@
+package com.destroystokyo.paper.antixray;
+
+import net.minecraft.network.protocol.game.ClientboundLevelChunkPacketData;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.Palette;
+
+public class ChunkPacketInfo<T> {
+
+    private final ClientboundLevelChunkPacketData chunkPacket;
+    private final LevelChunk chunk;
+    private final int[] bits;
+    private final Object[] palettes;
+    private final int[] indexes;
+    private final Object[][] presetValues;
+    private byte[] buffer;
+
+    public ChunkPacketInfo(ClientboundLevelChunkPacketData chunkPacket, LevelChunk chunk) {
+        this.chunkPacket = chunkPacket;
+        this.chunk = chunk;
+        int sections = chunk.getSectionsCount();
+        this.bits = new int[sections];
+        this.palettes = new Object[sections];
+        this.indexes = new int[sections];
+        this.presetValues = new Object[sections][];
+    }
+
+    public ClientboundLevelChunkPacketData getChunkPacket() {
+        return this.chunkPacket;
+    }
+
+    public LevelChunk getChunk() {
+        return this.chunk;
+    }
+
+    public byte[] getBuffer() {
+        return this.buffer;
+    }
+
+    public void setBuffer(byte[] buffer) {
+        this.buffer = buffer;
+    }
+
+    public int getBits(int chunkSectionIndex) {
+        return this.bits[chunkSectionIndex];
+    }
+
+    public void setBits(int chunkSectionIndex, int bits) {
+        this.bits[chunkSectionIndex] = bits;
+    }
+
+    @SuppressWarnings("unchecked")
+    public Palette<T> getPalette(int chunkSectionIndex) {
+        return (Palette<T>) this.palettes[chunkSectionIndex];
+    }
+
+    public void setPalette(int chunkSectionIndex, Palette<T> palette) {
+        this.palettes[chunkSectionIndex] = palette;
+    }
+
+    public int getIndex(int chunkSectionIndex) {
+        return this.indexes[chunkSectionIndex];
+    }
+
+    public void setIndex(int chunkSectionIndex, int index) {
+        this.indexes[chunkSectionIndex] = index;
+    }
+
+    @SuppressWarnings("unchecked")
+    public T[] getPresetValues(int chunkSectionIndex) {
+        return (T[]) this.presetValues[chunkSectionIndex];
+    }
+
+    public void setPresetValues(int chunkSectionIndex, T[] presetValues) {
+        this.presetValues[chunkSectionIndex] = presetValues;
+    }
+
+    public boolean isWritten(int chunkSectionIndex) {
+        return this.bits[chunkSectionIndex] != 0;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfoAntiXray.java b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfoAntiXray.java
new file mode 100644
index 0000000000000000000000000000000000000000..a3ee0cf08076848806912b983d386caadf762acc
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfoAntiXray.java
@@ -0,0 +1,29 @@
+package com.destroystokyo.paper.antixray;
+
+import net.minecraft.network.protocol.game.ClientboundLevelChunkPacketData;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.LevelChunk;
+
+public final class ChunkPacketInfoAntiXray extends ChunkPacketInfo<BlockState> implements Runnable {
+
+    private final ChunkPacketBlockControllerAntiXray chunkPacketBlockControllerAntiXray;
+    private LevelChunk[] nearbyChunks;
+
+    public ChunkPacketInfoAntiXray(ClientboundLevelChunkPacketData chunkPacket, LevelChunk chunk, ChunkPacketBlockControllerAntiXray chunkPacketBlockControllerAntiXray) {
+        super(chunkPacket, chunk);
+        this.chunkPacketBlockControllerAntiXray = chunkPacketBlockControllerAntiXray;
+    }
+
+    public LevelChunk[] getNearbyChunks() {
+        return this.nearbyChunks;
+    }
+
+    public void setNearbyChunks(LevelChunk... nearbyChunks) {
+        this.nearbyChunks = nearbyChunks;
+    }
+
+    @Override
+    public void run() {
+        this.chunkPacketBlockControllerAntiXray.obfuscate(this);
+    }
+}
diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java
index dba11f277f3703e1ee7f5a62f021d319e4ab18fc..a6f693ee925b03aa591720864d6b493dfe89e4e8 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java
@@ -33,7 +33,24 @@ public class ClientboundLevelChunkPacketData {
     }
     // Paper end
 
-    public ClientboundLevelChunkPacketData(LevelChunk chunk) {
+    // Paper start - Async-Anti-Xray - Ready flag for the connection
+    private volatile boolean ready;
+
+    @Override
+    public boolean isReady() {
+        return this.ready;
+    }
+
+    public void setReady(boolean ready) {
+        this.ready = ready;
+    }
+    // Paper end
+
+    // Paper start - Anti-Xray - Add chunk packet info
+    @Deprecated public ClientboundLevelChunkPacketData(LevelChunk chunk) { this(chunk, true); } // Notice for updates: Please make sure this constructor isn't used anywhere
+    public ClientboundLevelChunkPacketData(LevelChunk chunk, boolean modifyBlocks) {
+        com.destroystokyo.paper.antixray.ChunkPacketInfo<net.minecraft.world.level.block.state.BlockState> chunkPacketInfo = modifyBlocks ? chunk.level.chunkPacketBlockController.getChunkPacketInfo(this, chunk) : null;
+        // Paper end
         this.heightmaps = new CompoundTag();
 
         for(Entry<Heightmap.Types, Heightmap> entry : chunk.getHeightmaps()) {
@@ -43,7 +60,13 @@ public class ClientboundLevelChunkPacketData {
         }
 
         this.buffer = new byte[calculateChunkSize(chunk)];
-        extractChunkData(new FriendlyByteBuf(this.getWriteBuffer()), chunk);
+        // Paper start - Anti-Xray - Add chunk packet info
+        if (chunkPacketInfo != null) {
+            chunkPacketInfo.setBuffer(this.buffer);
+        }
+
+        this.extractChunkData(new FriendlyByteBuf(this.getWriteBuffer()), chunk, chunkPacketInfo);
+        // Paper end
         this.blockEntitiesData = Lists.newArrayList();
         int totalTileEntities = 0; // Paper
 
@@ -60,6 +83,7 @@ public class ClientboundLevelChunkPacketData {
             this.blockEntitiesData.add(ClientboundLevelChunkPacketData.BlockEntityInfo.create(entry2.getValue()));
         }
 
+        chunk.level.chunkPacketBlockController.modifyBlocks(this, chunkPacketInfo); // Paper - Anti-Xray - Modify blocks
     }
 
     public ClientboundLevelChunkPacketData(FriendlyByteBuf buf, int x, int z) {
@@ -103,9 +127,11 @@ public class ClientboundLevelChunkPacketData {
         return byteBuf;
     }
 
-    public static void extractChunkData(FriendlyByteBuf buf, LevelChunk chunk) {
+    // Paper start - Anti-Xray - Add chunk packet info
+    @Deprecated public static void extractChunkData(FriendlyByteBuf buf, LevelChunk chunk) { extractChunkData(buf, chunk, null); } // Notice for updates: Please make sure this method isn't used anywhere
+    public static void extractChunkData(FriendlyByteBuf buf, LevelChunk chunk, com.destroystokyo.paper.antixray.ChunkPacketInfo<net.minecraft.world.level.block.state.BlockState> chunkPacketInfo) {
         for(LevelChunkSection levelChunkSection : chunk.getSections()) {
-            levelChunkSection.write(buf);
+            levelChunkSection.write(buf, chunkPacketInfo);
         }
 
     }
diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkWithLightPacket.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkWithLightPacket.java
index 079734654c0fd421561b5f9003cd318bad5787a9..dc8ff27a3851982b0a798274ddb5e13af6917794 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkWithLightPacket.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkWithLightPacket.java
@@ -14,11 +14,12 @@ public class ClientboundLevelChunkWithLightPacket implements Packet<ClientGamePa
     private final ClientboundLevelChunkPacketData chunkData;
     private final ClientboundLightUpdatePacketData lightData;
 
-    public ClientboundLevelChunkWithLightPacket(LevelChunk chunk, LevelLightEngine lightProvider, @Nullable BitSet bitSet, @Nullable BitSet bitSet2, boolean bl) {
+    @Deprecated public ClientboundLevelChunkWithLightPacket(LevelChunk chunk, LevelLightEngine lightProvider, @Nullable BitSet bitSet, @Nullable BitSet bitSet2, boolean bl) { this(chunk, lightProvider, bitSet, bitSet2, bl, true); } // Paper - anti xray - make sure this isn't called anywhere
+    public ClientboundLevelChunkWithLightPacket(LevelChunk chunk, LevelLightEngine lightProvider, @Nullable BitSet bitSet, @Nullable BitSet bitSet2, boolean bl, boolean modifyBlocks) { // Paper - anti xray
         ChunkPos chunkPos = chunk.getPos();
         this.x = chunkPos.x;
         this.z = chunkPos.z;
-        this.chunkData = new ClientboundLevelChunkPacketData(chunk);
+        this.chunkData = new ClientboundLevelChunkPacketData(chunk, modifyBlocks); // Paper - anti xray
         this.lightData = new ClientboundLightUpdatePacketData(chunkPos, lightProvider, bitSet, bitSet2, bl);
     }
 
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index f3f6fc973cd75a42594f1ec222c220e3894e11ee..b70cabde8408c9876255bd939f9f77d61e5392df 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -1648,7 +1648,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     private void playerLoadedChunk(ServerPlayer player, MutableObject<ClientboundLevelChunkWithLightPacket> cachedDataPacket, LevelChunk chunk) {
         if (cachedDataPacket.getValue() == null) {
-            cachedDataPacket.setValue(new ClientboundLevelChunkWithLightPacket(chunk, this.lightEngine, (BitSet) null, (BitSet) null, true));
+            cachedDataPacket.setValue(new ClientboundLevelChunkWithLightPacket(chunk, this.lightEngine, (BitSet) null, (BitSet) null, true, chunk.level.chunkPacketBlockController.shouldModify(player, chunk))); // Paper - Ani-Xray - Bypass
         }
 
         player.trackChunk(chunk.getPos(), (Packet) cachedDataPacket.getValue());
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index 09deaa9badf53bdc1292796c643751d8d92ac585..6c4f1fa1d96f906f3b4e1e352c919155a1092530 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -391,7 +391,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
     // Add env and gen to constructor, WorldData -> WorldDataServer
     public ServerLevel(MinecraftServer minecraftserver, Executor executor, LevelStorageSource.LevelStorageAccess convertable_conversionsession, ServerLevelData iworlddataserver, ResourceKey<Level> resourcekey, DimensionType dimensionmanager, ChunkProgressListener worldloadlistener, ChunkGenerator chunkgenerator, boolean flag, long i, List<CustomSpawner> list, boolean flag1, org.bukkit.World.Environment env, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider) {
         // Objects.requireNonNull(minecraftserver); // CraftBukkit - decompile error
-        super(iworlddataserver, resourcekey, dimensionmanager, minecraftserver::getProfiler, false, flag, i, gen, biomeProvider, env);
+        super(iworlddataserver, resourcekey, dimensionmanager, minecraftserver::getProfiler, false, flag, i, gen, biomeProvider, env, executor); // Paper - Anti-Xray - Pass executor
         this.pvpMode = minecraftserver.isPvpAllowed();
         this.convertable = convertable_conversionsession;
         this.uuid = WorldUUID.getUUID(convertable_conversionsession.levelPath.toFile());
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
index 44e5ab0b545de41b937c7ce304ce643f78a43734..a85b89a0d525e623e154c8b1bea55470d2072dcb 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
@@ -48,7 +48,7 @@ import org.bukkit.event.player.PlayerInteractEvent;
 public class ServerPlayerGameMode {
 
     private static final Logger LOGGER = LogManager.getLogger();
-    protected ServerLevel level;
+    public ServerLevel level; // Paper - Anti-Xray - protected -> public
     protected final ServerPlayer player;
     private GameType gameModeForPlayer;
     @Nullable
@@ -314,6 +314,8 @@ public class ServerPlayerGameMode {
             }
 
         }
+
+        this.level.chunkPacketBlockController.onPlayerLeftClickBlock(this, pos, action, direction, worldHeight); // Paper - Anti-Xray
     }
 
     public void destroyAndAck(BlockPos pos, ServerboundPlayerActionPacket.Action action, String reason) {
diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index de7abae207b0a565a25fa4ed2f66b94c6b0cdcf9..69ac5ec34b6eb95036b679ed299e11766093935c 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -167,6 +167,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
     public final org.spigotmc.SpigotWorldConfig spigotConfig; // Spigot
 
     public final com.destroystokyo.paper.PaperWorldConfig paperConfig; // Paper
+    public final com.destroystokyo.paper.antixray.ChunkPacketBlockController chunkPacketBlockController; // Paper - Anti-Xray
 
     public final co.aikar.timings.WorldTimingsHandler timings; // Paper
     public static BlockPos lastPhysicsProblem; // Spigot
@@ -186,7 +187,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
 
     public abstract ResourceKey<LevelStem> getTypeKey();
 
-    protected Level(WritableLevelData worlddatamutable, ResourceKey<Level> resourcekey, final DimensionType dimensionmanager, Supplier<ProfilerFiller> supplier, boolean flag, boolean flag1, long i, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider, org.bukkit.World.Environment env) {
+    protected Level(WritableLevelData worlddatamutable, ResourceKey<Level> resourcekey, final DimensionType dimensionmanager, Supplier<ProfilerFiller> supplier, boolean flag, boolean flag1, long i, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider, org.bukkit.World.Environment env, java.util.concurrent.Executor executor) { // Paper - Anti-Xray - Pass executor
         this.spigotConfig = new org.spigotmc.SpigotWorldConfig(((net.minecraft.world.level.storage.PrimaryLevelData) worlddatamutable).getLevelName()); // Spigot
         this.paperConfig = new com.destroystokyo.paper.PaperWorldConfig(((net.minecraft.world.level.storage.PrimaryLevelData) worlddatamutable).getLevelName(), this.spigotConfig); // Paper
         this.generator = gen;
@@ -262,6 +263,9 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         this.keepSpawnInMemory = this.paperConfig.keepSpawnInMemory; // Paper
         this.entityLimiter = new org.spigotmc.TickLimiter(spigotConfig.entityMaxTickTime);
         this.tileLimiter = new org.spigotmc.TickLimiter(spigotConfig.tileMaxTickTime);
+        this.chunkPacketBlockController = this.paperConfig.antiXray ?
+            new com.destroystokyo.paper.antixray.ChunkPacketBlockControllerAntiXray(this, executor)
+            : com.destroystokyo.paper.antixray.ChunkPacketBlockController.NO_OPERATION_INSTANCE; // Paper - Anti-Xray
     }
 
     // Paper start
@@ -441,6 +445,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
             // CraftBukkit end
 
             BlockState iblockdata1 = chunk.setBlockState(pos, state, (flags & 64) != 0, (flags & 1024) == 0); // CraftBukkit custom NO_PLACE flag
+            this.chunkPacketBlockController.onBlockChange(this, pos, state, iblockdata1, flags, maxUpdateDepth); // Paper - Anti-Xray
 
             if (iblockdata1 == null) {
                 // CraftBukkit start - remove blockstate if failed (or the same)
diff --git a/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java b/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
index 92a42aea3f54c49e2055e8000645d91da9471e09..2e651fcf0227dcf0d36fba6bf6e4ba6a5e21dfd7 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
@@ -158,9 +158,12 @@ public class LevelChunkSection {
         this.biomes.read(buf);
     }
 
-    public void write(FriendlyByteBuf buf) {
+    // Paper start - Anti-Xray - Add chunk packet info
+    @Deprecated public void write(FriendlyByteBuf buf) { write(buf, null); } // Notice for updates: Please make sure this method isn't used anywhere
+    public void write(FriendlyByteBuf buf, com.destroystokyo.paper.antixray.ChunkPacketInfo<BlockState> chunkPacketInfo) {
+        // Paper end
         buf.writeShort(this.nonEmptyBlockCount);
-        this.states.write(buf);
+        this.states.write(buf, chunkPacketInfo, this.bottomBlockY); // Paper - Anti-Xray - Add chunk packet info
         this.biomes.write(buf);
     }
 
diff --git a/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java b/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java
index b7b81cbdb36b0041177e012cb932d4267638d9c9..803b75e88e96d4bdcde002fde4000d136d6f07e5 100644
--- a/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java
+++ b/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java
@@ -33,6 +33,7 @@ public class PalettedContainer<T> implements PaletteResize<T> {
         return 0;
     };
     public final IdMap<T> registry;
+    private final T[] presetValues; // Paper - Anti-Xray - Add preset values
     private volatile PalettedContainer.Data<T> data;
     private final PalettedContainer.Strategy strategy;
     private final Semaphore lock = new Semaphore(1);
@@ -63,14 +64,47 @@ public class PalettedContainer<T> implements PaletteResize<T> {
         });
     }
 
-    public PalettedContainer(IdMap<T> idList, PalettedContainer.Strategy paletteProvider, PalettedContainer.Configuration<T> dataProvider, BitStorage storage, List<T> list) {
+    // Paper start - Anti-Xray - Add preset values
+    @Deprecated public PalettedContainer(IdMap<T> idList, PalettedContainer.Strategy paletteProvider, PalettedContainer.Configuration<T> dataProvider, BitStorage storage, List<T> list) { // Notice for updates: Please make sure this constructor isn't used anywhere
+        this(idList, paletteProvider, dataProvider, storage, list, null, true);
+    }
+    public PalettedContainer(IdMap<T> idList, PalettedContainer.Strategy paletteProvider, PalettedContainer.Configuration<T> dataProvider, BitStorage storage, List<T> list, T[] presetValues, boolean initialize) {
+        // Paper end
         this.registry = idList;
         this.strategy = paletteProvider;
         Palette<T> datapalette = dataProvider.factory().create(dataProvider.bits(), idList, this, list);
 
         this.data = new PalettedContainer.Data(dataProvider, storage, datapalette);
+        // Paper start - Anti-Xray - Add preset values
+        this.presetValues = presetValues;
+
+        if(initialize) {
+            if(presetValues == null) {
+                // Default
+                this.setBits(4);
+            } else {
+                // Count the number of required bits
+                // Preset values:   presetValues.length - 1
+                // Air:                                 + 1
+                // Extra:                              + 15
+                // Air and extra correspond to the default behavior this.setBits(4)
+                this.setBits(32 - Integer.numberOfLeadingZeros(presetValues.length + 15));
+                this.addPresetValues();
+            }
+        }
+        // Paper end
     }
 
+    // Paper start - Anti-Xray - Add preset values
+    private void addPresetValues() {
+        if (this.presetValues != null && this.palette != this.globalPalette) {
+            for (T presetValue : this.presetValues) {
+                this.palette.idFor(presetValue);
+            }
+        }
+    }
+    // Paper end
+
     public PalettedContainer(IdMap<T> idList, T object, PalettedContainer.Strategy paletteProvider) {
         this.strategy = paletteProvider;
         this.registry = idList;
@@ -88,6 +122,7 @@ public class PalettedContainer<T> implements PaletteResize<T> {
     public int onResize(int newBits, T object) {
         PalettedContainer.Data<T> datapaletteblock_c = this.data;
         PalettedContainer.Data<T> datapaletteblock_c1 = this.createOrReuseData(datapaletteblock_c, newBits);
+        this.addPresetValues(); // Paper - Anti-Xray - Add preset values
 
         datapaletteblock_c1.copyFrom(datapaletteblock_c.palette, datapaletteblock_c.storage);
         this.data = datapaletteblock_c1;
@@ -168,17 +203,26 @@ public class PalettedContainer<T> implements PaletteResize<T> {
             datapaletteblock_c.palette.read(buf);
             buf.readLongArray(datapaletteblock_c.storage.getRaw());
             this.data = datapaletteblock_c;
+            // Paper start - Anti-Xray - Add preset values
+            // If there are many preset values this may require several resize operations
+            // This can be avoided by calculating the required bits in advance, as it is done in #read(ListTag, long[])
+            // However, this method is only used by the client, so it does not matter
+            this.addPresetValues();
+            // Paper end
         } finally {
             this.release();
         }
 
     }
 
-    public void write(FriendlyByteBuf buf) {
+    // Paper start - Anti-Xray - Add chunk packet info
+    @Deprecated public void write(FriendlyByteBuf buf) { write(buf, null, 0); } // Notice for updates: Please make sure this method isn't used anywhere
+    public void write(FriendlyByteBuf buf, com.destroystokyo.paper.antixray.ChunkPacketInfo<T> chunkPacketInfo, int bottomBlockY) {
+        // Paper end
         this.acquire();
 
         try {
-            this.data.write(buf);
+            this.data.write(buf, chunkPacketInfo, bottomBlockY);
         } finally {
             this.release();
         }
@@ -188,6 +232,7 @@ public class PalettedContainer<T> implements PaletteResize<T> {
     private static <T> DataResult<PalettedContainer<T>> read(IdMap<T> idList, PalettedContainer.Strategy provider, PalettedContainer.DiscData<T> serialized) {
         List<T> list = serialized.paletteEntries();
         int i = provider.size();
+        // TODO I think we need to inject the old code into the calculateBitsForSerialization method
         int j = provider.calculateBitsForSerialization(idList, list.size());
         PalettedContainer.Configuration<T> datapaletteblock_a = provider.getConfiguration(idList, j);
         Object object;
@@ -224,7 +269,7 @@ public class PalettedContainer<T> implements PaletteResize<T> {
             }
         }
 
-        return DataResult.success(new PalettedContainer<>(idList, provider, datapaletteblock_a, (BitStorage) object, list));
+        return DataResult.success(new PalettedContainer<>(idList, provider, datapaletteblock_a, (BitStorage) object, list, this.presetValues, true));
     }
 
     private PalettedContainer.DiscData<T> write(IdMap<T> idList, PalettedContainer.Strategy provider) {
@@ -450,9 +495,22 @@ public class PalettedContainer<T> implements PaletteResize<T> {
             return 1 + this.palette.getSerializedSize() + FriendlyByteBuf.getVarIntSize(this.storage.getSize()) + this.storage.getRaw().length * 8;
         }
 
-        public void write(FriendlyByteBuf buf) {
+        // Paper start - Anti-Xray - Add chunk packet info
+        @Deprecated public void write(FriendlyByteBuf buf) { this.write(buf, null, 0);} // Notice for updates: Please make sure this method isn't used anywhere - it is used for biomes now
+        public void write(FriendlyByteBuf buf, com.destroystokyo.paper.antixray.ChunkPacketInfo<T> chunkPacketInfo, int bottomBlockY) {
+            // Paper end
             buf.writeByte(this.storage.getBits());
             this.palette.write(buf);
+            // Paper start - Anti-Xray - Add chunk packet info
+            if (chunkPacketInfo != null) {
+                // Bottom block to 0 based chunk section index
+                int chunkSectionIndex = (bottomBlockY >> 4) - chunkPacketInfo.getChunk().getMinSection();
+                chunkPacketInfo.setBits(chunkSectionIndex, this.storage.getBits());
+                chunkPacketInfo.setPalette(chunkSectionIndex, this.palette);
+                chunkPacketInfo.setIndex(chunkSectionIndex, buf.writerIndex() + FriendlyByteBuf.getVarIntSize(this.storage.getRaw().length));
+                chunkPacketInfo.setPresetValues(chunkSectionIndex, this.presetValues); // TODO where do we get this from?
+            }
+            // Paper end
             buf.writeLongArray(this.storage.getRaw());
         }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 8d1cbefc82f64a120eeea8c6bdd6361ffa513099..e8cb57d79c73f115679ddc2e6f579b5e1b5e482b 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -2204,7 +2204,7 @@ public final class CraftServer implements Server {
     public ChunkGenerator.ChunkData createChunkData(World world) {
         Validate.notNull(world, "World cannot be null");
         ServerLevel handle = ((CraftWorld) world).getHandle();
-        return new OldCraftChunkData(world.getMinHeight(), world.getMaxHeight(), handle.registryAccess().registryOrThrow(Registry.BIOME_REGISTRY));
+        return new OldCraftChunkData(world.getMinHeight(), world.getMaxHeight(), handle.registryAccess().registryOrThrow(Registry.BIOME_REGISTRY). world); // Paper - anti xray - add parameters
     }
 
     @Override
diff --git a/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java b/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java
index 960405935e395a31c0300773c41413801cf0d290..7acf5e6e7e038895d49a0d01d319eb7c8ba809bf 100644
--- a/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java
@@ -27,8 +27,13 @@ public final class OldCraftChunkData implements ChunkGenerator.ChunkData {
     private final Registry<net.minecraft.world.level.biome.Biome> biomes;
     private Set<BlockPos> tiles;
     private final Set<BlockPos> lights = new HashSet<>();
+    private World world; // Paper - Anti-Xray - Add parameters
 
-    public OldCraftChunkData(int minHeight, int maxHeight, Registry<net.minecraft.world.level.biome.Biome> biomes) {
+// Paper start - Anti-Xray - Add parameters
+    @Deprecated OldCraftChunkData(int minHeight, int maxHeight, Registry<net.minecraft.world.level.biome.Biome> biomes) { this(minHeight, maxHeight, biomes, null); } // Only used in tests
+    public OldCraftChunkData(int minHeight, int maxHeight, Registry<net.minecraft.world.level.biome.Biome> biomes, World world) {
+        this.world = world;
+        // Paper end
         this.minHeight = minHeight;
         this.maxHeight = maxHeight;
         this.biomes = biomes;
@@ -176,7 +181,11 @@ public final class OldCraftChunkData implements ChunkGenerator.ChunkData {
         int offset = (y - this.minHeight) >> 4;
         LevelChunkSection section = this.sections[offset];
         if (create && section == null) {
+<<<<<<< HEAD
             this.sections[offset] = section = new LevelChunkSection(offset + (this.minHeight >> 4), this.biomes);
+=======
+            this.sections[offset] = section = new LevelChunkSection(offset + (this.minHeight >> 4), this.biomes, null, world instanceof org.bukkit.craftbukkit.CraftWorld ? ((org.bukkit.craftbukkit.CraftWorld) this.world).getHandle() : null, true); // Paper - Anti-Xray - Add parameters
+>>>>>>> Anti-Xray
         }
         return section;
     }