papermc/Spigot-Server-Patches/0387-Anti-Xray.patch

From b023a025f9e7e5960b1b4b52ceaeb10a6935f5fc 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 99f1541b9..6634ef923 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -1,7 +1,11 @@
 package com.destroystokyo.paper;
 
+import java.util.Arrays;
 import java.util.List;
 
+import com.destroystokyo.paper.antixray.ChunkPacketBlockControllerAntiXray.ChunkEdgeMode;
+import com.destroystokyo.paper.antixray.ChunkPacketBlockControllerAntiXray.EngineMode;
+import net.minecraft.server.MinecraftServer;
 import org.bukkit.Bukkit;
 import org.bukkit.configuration.file.YamlConfiguration;
 import org.spigotmc.SpigotWorldConfig;
@@ -500,4 +504,43 @@ public class PaperWorldConfig {
     private void maxAutoSaveChunksPerTick() {
         maxAutoSaveChunksPerTick = getInt("max-auto-save-chunks-per-tick", 24);
     }
+
+    public boolean antiXray;
+    public boolean asynchronous;
+    public EngineMode engineMode;
+    public ChunkEdgeMode chunkEdgeMode;
+    public int maxChunkSectionIndex;
+    public int updateRadius;
+    public List<String> hiddenBlocks;
+    public List<String> replacementBlocks;
+    private void antiXray() {
+        antiXray = getBoolean("anti-xray.enabled", false);
+        asynchronous = true;
+        engineMode = EngineMode.getById(getInt("anti-xray.engine-mode", EngineMode.HIDE.getId()));
+        engineMode = engineMode == null ? EngineMode.HIDE : engineMode;
+        chunkEdgeMode = ChunkEdgeMode.getById(getInt("anti-xray.chunk-edge-mode", ChunkEdgeMode.WAIT.getId()));
+        chunkEdgeMode = chunkEdgeMode == null ? ChunkEdgeMode.DEFAULT : chunkEdgeMode;
+
+        if (chunkEdgeMode != ChunkEdgeMode.WAIT) {
+            log("Migrating anti-xray chunk edge mode to " + ChunkEdgeMode.WAIT + " (" + ChunkEdgeMode.WAIT.getId() + ")");
+            chunkEdgeMode = ChunkEdgeMode.WAIT;
+            set("anti-xray.chunk-edge-mode", ChunkEdgeMode.WAIT.getId());
+        }
+
+        maxChunkSectionIndex = getInt("anti-xray.max-chunk-section-index", 3);
+        maxChunkSectionIndex = maxChunkSectionIndex > 15 ? 15 : maxChunkSectionIndex;
+        updateRadius = getInt("anti-xray.update-radius", 2);
+        hiddenBlocks = getList("anti-xray.hidden-blocks", Arrays.asList("gold_ore", "iron_ore", "coal_ore", "lapis_ore", "mossy_cobblestone", "obsidian", "chest", "diamond_ore", "redstone_ore", "clay", "emerald_ore", "ender_chest"));
+        replacementBlocks = getList("anti-xray.replacement-blocks", Arrays.asList("stone", "oak_planks"));
+        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() + " / Chunk Edge Mode: " + chunkEdgeMode.getDescription() + " / Up to " + ((maxChunkSectionIndex + 1) * 16) + " blocks / Update Radius: " + updateRadius);
+    }
 }
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 000000000..f7e376ce6
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockController.java
@@ -0,0 +1,46 @@
+package com.destroystokyo.paper.antixray;
+
+import net.minecraft.server.BlockPosition;
+import net.minecraft.server.Chunk;
+import net.minecraft.server.ChunkSection;
+import net.minecraft.server.EnumDirection;
+import net.minecraft.server.IBlockData;
+import net.minecraft.server.IChunkAccess;
+import net.minecraft.server.IWorldReader;
+import net.minecraft.server.PacketPlayOutMapChunk;
+import net.minecraft.server.PlayerInteractManager;
+import net.minecraft.server.World;
+
+public class ChunkPacketBlockController {
+
+    public static final ChunkPacketBlockController NO_OPERATION_INSTANCE = new ChunkPacketBlockController();
+
+    protected ChunkPacketBlockController() {
+
+    }
+
+    public IBlockData[] getPredefinedBlockData(IWorldReader world, IChunkAccess chunk, ChunkSection chunkSection, boolean initializeBlocks) {
+        return null;
+    }
+
+    public boolean onChunkPacketCreate(Chunk chunk, int chunkSectionSelector, boolean force) {
+        return true;
+    }
+
+    public ChunkPacketInfo<IBlockData> getChunkPacketInfo(PacketPlayOutMapChunk packetPlayOutMapChunk, Chunk chunk,
+                                                          int chunkSectionSelector, boolean forceLoad) {
+        return null;
+    }
+
+    public void modifyBlocks(PacketPlayOutMapChunk packetPlayOutMapChunk, ChunkPacketInfo<IBlockData> chunkPacketInfo, boolean loadChunks, Integer ticketHold) {
+        packetPlayOutMapChunk.setReady(true);
+    }
+
+    public void onBlockChange(World world, BlockPosition blockPosition, IBlockData newBlockData, IBlockData oldBlockData, int flag) {
+
+    }
+
+    public void onPlayerLeftClickBlock(PlayerInteractManager playerInteractManager, BlockPosition blockPosition, EnumDirection enumDirection) {
+
+    }
+}
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 000000000..23626bef3
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketBlockControllerAntiXray.java
@@ -0,0 +1,782 @@
+package com.destroystokyo.paper.antixray;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Supplier;
+
+import net.minecraft.server.*;
+import org.bukkit.Bukkit;
+import org.bukkit.World.Environment;
+
+import com.destroystokyo.paper.PaperWorldConfig;
+
+public class ChunkPacketBlockControllerAntiXray extends ChunkPacketBlockController {
+
+    private static ExecutorService executorServiceInstance = null;
+    private final ExecutorService executorService;
+    private final boolean asynchronous;
+    private final EngineMode engineMode;
+    private final ChunkEdgeMode chunkEdgeMode;
+    private final int maxChunkSectionIndex;
+    private final int updateRadius;
+    private final IBlockData[] predefinedBlockData;
+    private final IBlockData[] predefinedBlockDataStone;
+    private final IBlockData[] predefinedBlockDataNetherrack;
+    private final IBlockData[] predefinedBlockDataEndStone;
+    private final int[] predefinedBlockDataBitsGlobal;
+    private final int[] predefinedBlockDataBitsStoneGlobal;
+    private final int[] predefinedBlockDataBitsNetherrackGlobal;
+    private final int[] predefinedBlockDataBitsEndStoneGlobal;
+    private final boolean[] solidGlobal = new boolean[Block.REGISTRY_ID.size()];
+    private final boolean[] obfuscateGlobal = new boolean[Block.REGISTRY_ID.size()];
+    private final ChunkSection[] emptyNearbyChunkSections = {Chunk.EMPTY_CHUNK_SECTION, Chunk.EMPTY_CHUNK_SECTION, Chunk.EMPTY_CHUNK_SECTION, Chunk.EMPTY_CHUNK_SECTION};
+    private final int maxBlockYUpdatePosition;
+
+    public ChunkPacketBlockControllerAntiXray(PaperWorldConfig paperWorldConfig) {
+        asynchronous = paperWorldConfig.asynchronous;
+        engineMode = paperWorldConfig.engineMode;
+        chunkEdgeMode = paperWorldConfig.chunkEdgeMode;
+        maxChunkSectionIndex = paperWorldConfig.maxChunkSectionIndex;
+        updateRadius = paperWorldConfig.updateRadius;
+
+        if (asynchronous) {
+            executorService = getExecutorServiceInstance();
+        } else {
+            executorService = null;
+        }
+
+        List<String> toObfuscate;
+
+        if (engineMode == EngineMode.HIDE) {
+            toObfuscate = paperWorldConfig.hiddenBlocks;
+            predefinedBlockData = null;
+            predefinedBlockDataStone = new IBlockData[] {Blocks.STONE.getBlockData()};
+            predefinedBlockDataNetherrack = new IBlockData[] {Blocks.NETHERRACK.getBlockData()};
+            predefinedBlockDataEndStone = new IBlockData[] {Blocks.END_STONE.getBlockData()};
+            predefinedBlockDataBitsGlobal = null;
+            predefinedBlockDataBitsStoneGlobal = new int[] {ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(Blocks.STONE.getBlockData())};
+            predefinedBlockDataBitsNetherrackGlobal = new int[] {ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(Blocks.NETHERRACK.getBlockData())};
+            predefinedBlockDataBitsEndStoneGlobal = new int[] {ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(Blocks.END_STONE.getBlockData())};
+        } else {
+            toObfuscate = new ArrayList<>(paperWorldConfig.replacementBlocks);
+            Set<IBlockData> predefinedBlockDataSet = new HashSet<IBlockData>();
+
+            for (String id : paperWorldConfig.hiddenBlocks) {
+                Block block = IRegistry.BLOCK.getOptional(new MinecraftKey(id)).orElse(null);
+
+                if (block != null && !block.isTileEntity()) {
+                    toObfuscate.add(id);
+                    predefinedBlockDataSet.add(block.getBlockData());
+                }
+            }
+
+            predefinedBlockData = predefinedBlockDataSet.size() == 0 ? new IBlockData[] {Blocks.DIAMOND_ORE.getBlockData()} : predefinedBlockDataSet.toArray(new IBlockData[0]);
+            predefinedBlockDataStone = null;
+            predefinedBlockDataNetherrack = null;
+            predefinedBlockDataEndStone = null;
+            predefinedBlockDataBitsGlobal = new int[predefinedBlockData.length];
+
+            for (int i = 0; i < predefinedBlockData.length; i++) {
+                predefinedBlockDataBitsGlobal[i] = ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(predefinedBlockData[i]);
+            }
+
+            predefinedBlockDataBitsStoneGlobal = null;
+            predefinedBlockDataBitsNetherrackGlobal = null;
+            predefinedBlockDataBitsEndStoneGlobal = null;
+        }
+
+        for (String id : toObfuscate) {
+            Block block = IRegistry.BLOCK.getOptional(new MinecraftKey(id)).orElse(null);
+
+            if (block != null) {
+                obfuscateGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(block.getBlockData())] = true;
+            }
+        }
+
+        ChunkEmpty emptyChunk = new ChunkEmpty(null, new ChunkCoordIntPair(0, 0));
+        BlockPosition zeroPos = new BlockPosition(0, 0, 0);
+
+        for (int i = 0; i < solidGlobal.length; i++) {
+            IBlockData blockData = ChunkSection.GLOBAL_PALETTE.getObject(i);
+
+            if (blockData != null) {
+                solidGlobal[i] = blockData.getBlock().isOccluding(blockData, emptyChunk, zeroPos)
+                    && blockData.getBlock() != Blocks.SPAWNER && blockData.getBlock() != Blocks.BARRIER && blockData.getBlock() != Blocks.SHULKER_BOX;
+                // shulker box checks TE.
+            }
+        }
+
+        this.maxBlockYUpdatePosition = (maxChunkSectionIndex + 1) * 16 + updateRadius - 1;
+    }
+
+    private static ExecutorService getExecutorServiceInstance() {
+        if (executorServiceInstance == null) {
+            executorServiceInstance = Executors.newSingleThreadExecutor();
+        }
+
+        return executorServiceInstance;
+    }
+
+    @Override
+    public IBlockData[] getPredefinedBlockData(IWorldReader world, IChunkAccess chunk, ChunkSection chunkSection, boolean initializeBlocks) {
+        //Return the block data which should be added to the data palettes so that they can be used for the obfuscation
+        if (chunkSection.getYPosition() >> 4 <= maxChunkSectionIndex) {
+            switch (engineMode) {
+                case HIDE:
+                    if (world instanceof GeneratorAccess) {
+                        switch (((GeneratorAccess) world).getMinecraftWorld().getWorld().getEnvironment()) {
+                            case NETHER:
+                                return predefinedBlockDataNetherrack;
+                            case THE_END:
+                                return predefinedBlockDataEndStone;
+                            default:
+                                return predefinedBlockDataStone;
+                        }
+                    }
+
+                    return null;
+                default:
+                    return predefinedBlockData;
+            }
+        }
+
+        return null;
+    }
+
+    private final AtomicInteger xrayRequests = new AtomicInteger();
+
+    private Integer addXrayTickets(final int x, final int z, final ChunkProviderServer chunkProvider) {
+        final Integer hold = Integer.valueOf(this.xrayRequests.getAndIncrement());
+
+        // Add at ticket level 33, which is just enough to keep chunks loaded
+        chunkProvider.addTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x, z), 0, hold);
+        chunkProvider.addTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x - 1, z), 0, hold);
+        chunkProvider.addTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x + 1, z), 0, hold);
+        chunkProvider.addTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x, z - 1), 0, hold);
+        chunkProvider.addTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x, z + 1), 0, hold);
+
+        return hold;
+    }
+
+    private void removeXrayTickets(final int x, final int z, final ChunkProviderServer chunkProvider, final Integer hold) {
+        // Remove at ticket level 33 (same one we added as), which is just enough to keep chunks loaded
+        chunkProvider.removeTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x, z), 0, hold);
+        chunkProvider.removeTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x - 1, z), 0, hold);
+        chunkProvider.removeTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x + 1, z), 0, hold);
+        chunkProvider.removeTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x, z - 1), 0, hold);
+        chunkProvider.removeTicket(TicketType.ANTIXRAY, new ChunkCoordIntPair(x, z + 1), 0, hold);
+    }
+
+    private void loadNeighbours(Chunk chunk) {
+        int locX = chunk.getPos().x;
+        int locZ = chunk.getPos().z;
+        chunk.world.getChunkAt(locX - 1, locZ);
+        chunk.world.getChunkAt(locX + 1, locZ);
+        chunk.world.getChunkAt(locX, locZ - 1);
+        chunk.world.getChunkAt(locX, locZ + 1);
+    }
+
+    @Override
+    public boolean onChunkPacketCreate(Chunk chunk, int chunkSectionSelector, boolean force) {
+        int locX = chunk.getPos().x;
+        int locZ = chunk.getPos().z;
+        WorldServer world = (WorldServer)chunk.world;
+        ChunkProviderServer chunkProvider = world.getChunkProvider();
+
+        //Load nearby chunks if necessary
+        if (force || chunkEdgeMode == ChunkEdgeMode.LOAD) { // TODO temporary
+            // if forced, load NOW;
+            this.loadNeighbours(chunk);
+        } else if (chunkEdgeMode == ChunkEdgeMode.WAIT) {
+            if (chunkProvider.getChunkAtIfCachedImmediately(locX - 1, locZ) == null ||
+                chunkProvider.getChunkAtIfCachedImmediately(locX + 1, locZ) == null ||
+                chunkProvider.getChunkAtIfCachedImmediately(locX, locZ - 1) == null ||
+                chunkProvider.getChunkAtIfCachedImmediately(locX, locZ + 1) == null) {
+                //Don't create the chunk packet now, wait until nearby chunks are loaded and create it later
+                return false;
+            }
+        } else if (false && chunkEdgeMode == ChunkEdgeMode.LOAD) {
+            // TODO Note: These should be asynchronous loads; however we have no such thing in 1.14.
+            boolean missingChunk = false;
+            //noinspection ConstantConditions
+            /*
+            missingChunk |= ((WorldServer)chunk.world).getChunkProvider().getChunkAt(chunk.locX - 1, chunk.locZ, true, true, c -> {}) == null;
+            missingChunk |= ((WorldServer)chunk.world).getChunkProvider().getChunkAt(chunk.locX + 1, chunk.locZ, true, true, c -> {}) == null;
+            missingChunk |= ((WorldServer)chunk.world).getChunkProvider().getChunkAt(chunk.locX, chunk.locZ - 1, true, true, c -> {}) == null;
+            missingChunk |= ((WorldServer)chunk.world).getChunkProvider().getChunkAt(chunk.locX, chunk.locZ + 1, true, true, c -> {}) == null;
+             */
+            if (missingChunk) {
+                return false;
+            }
+        }
+
+        //Create the chunk packet now
+        return true;
+    }
+
+    @Override
+    public ChunkPacketInfoAntiXray getChunkPacketInfo(PacketPlayOutMapChunk packetPlayOutMapChunk, Chunk chunk,
+                                                      int chunkSectionSelector, boolean forceLoad) {
+        // Return a new instance to collect data and objects in the right state while creating the chunk packet for thread safe access later
+        // Note: As of 1.14 this has to be moved later due to the chunk system.
+
+        ChunkPacketInfoAntiXray chunkPacketInfoAntiXray = new ChunkPacketInfoAntiXray(packetPlayOutMapChunk, chunk, chunkSectionSelector, this);
+        return chunkPacketInfoAntiXray;
+    }
+
+    @Override
+    public void modifyBlocks(PacketPlayOutMapChunk packetPlayOutMapChunk, ChunkPacketInfo<IBlockData> chunkPacketInfo, boolean loadChunks, Integer hold) {
+        if (!Bukkit.isPrimaryThread()) {
+            // plugins?
+            final Integer finalHold = hold;
+            MinecraftServer.getServer().scheduleOnMain(() -> {
+                this.modifyBlocks(packetPlayOutMapChunk, chunkPacketInfo, loadChunks, finalHold);
+            });
+            return;
+        }
+        Chunk chunk = chunkPacketInfo.getChunk();
+        int locX = chunk.getPos().x;
+        int locZ = chunk.getPos().z;
+        WorldServer world = (WorldServer)chunk.world;
+
+        Chunk[] chunks = new Chunk[] {
+            (Chunk)world.getChunkIfLoadedImmediately(locX - 1, locZ),
+            (Chunk)world.getChunkIfLoadedImmediately(locX + 1, locZ),
+            (Chunk)world.getChunkIfLoadedImmediately(locX, locZ - 1),
+            (Chunk)world.getChunkIfLoadedImmediately(locX, locZ + 1)
+        };
+
+        if (loadChunks) {
+            // Note: This ugly hack is to get us out of the general chunk load/unload queue to prevent deadlock
+
+            if (chunks[0] == null || chunks[1] == null || chunks[2] == null || chunks[3] == null) {
+                // we need to load
+                MinecraftServer.getServer().scheduleOnMain(() -> {
+                    Integer ticketHold = this.addXrayTickets(locX, locZ, world.getChunkProvider());
+                    this.loadNeighbours(chunk);
+                    this.modifyBlocks(packetPlayOutMapChunk, chunkPacketInfo, false, ticketHold);
+                });
+                return;
+            }
+
+            hold = this.addXrayTickets(locX, locZ, world.getChunkProvider());
+            // fall through to normal behavior, our chunks are now loaded & have a ticket
+        }
+
+        ((ChunkPacketInfoAntiXray)chunkPacketInfo).setNearbyChunks(chunks);
+        ((ChunkPacketInfoAntiXray)chunkPacketInfo).ticketHold = hold;
+
+        if (asynchronous) {
+            executorService.submit((ChunkPacketInfoAntiXray) chunkPacketInfo);
+        } else {
+            obfuscate((ChunkPacketInfoAntiXray) chunkPacketInfo);
+        }
+    }
+
+    //Actually these fields should be variables inside the obfuscate method but in sync mode or with SingleThreadExecutor in async mode it's okay
+    private int[] predefinedBlockDataBits;
+    private final boolean[] solid = new boolean[Block.REGISTRY_ID.size()];
+    private final boolean[] obfuscate = new boolean[Block.REGISTRY_ID.size()];
+    //These boolean arrays represent chunk layers, true means don't obfuscate, false means obfuscate
+    private boolean[][] current = new boolean[16][16];
+    private boolean[][] next = new boolean[16][16];
+    private boolean[][] nextNext = new boolean[16][16];
+    private final DataBitsReader dataBitsReader = new DataBitsReader();
+    private final DataBitsWriter dataBitsWriter = new DataBitsWriter();
+    private final ChunkSection[] nearbyChunkSections = new ChunkSection[4];
+
+    public void obfuscate(ChunkPacketInfoAntiXray chunkPacketInfoAntiXray) {
+        try {
+            boolean[] solidTemp = null;
+            boolean[] obfuscateTemp = null;
+            dataBitsReader.setDataBits(chunkPacketInfoAntiXray.getData());
+            dataBitsWriter.setDataBits(chunkPacketInfoAntiXray.getData());
+            int counter = 0;
+
+            for (int chunkSectionIndex = 0; chunkSectionIndex <= maxChunkSectionIndex; chunkSectionIndex++) {
+                if (chunkPacketInfoAntiXray.isWritten(chunkSectionIndex) && chunkPacketInfoAntiXray.getPredefinedObjects(chunkSectionIndex) != null) {
+                    int[] predefinedBlockDataBitsTemp;
+
+                    if (chunkPacketInfoAntiXray.getDataPalette(chunkSectionIndex) == ChunkSection.GLOBAL_PALETTE) {
+                        predefinedBlockDataBitsTemp = engineMode == EngineMode.HIDE ? chunkPacketInfoAntiXray.getChunk().world.getWorld().getEnvironment() == Environment.NETHER ? predefinedBlockDataBitsNetherrackGlobal : chunkPacketInfoAntiXray.getChunk().world.getWorld().getEnvironment() == Environment.THE_END ? predefinedBlockDataBitsEndStoneGlobal : predefinedBlockDataBitsStoneGlobal : predefinedBlockDataBitsGlobal;
+                    } else {
+                        predefinedBlockDataBitsTemp = predefinedBlockDataBits == null ? predefinedBlockDataBits = engineMode == EngineMode.HIDE ? new int[1] : new int[predefinedBlockData.length] : predefinedBlockDataBits;
+
+                        for (int i = 0; i < predefinedBlockDataBitsTemp.length; i++) {
+                            predefinedBlockDataBitsTemp[i] = chunkPacketInfoAntiXray.getDataPalette(chunkSectionIndex).getOrCreateIdFor(chunkPacketInfoAntiXray.getPredefinedObjects(chunkSectionIndex)[i]);
+                        }
+                    }
+
+                    dataBitsWriter.setIndex(chunkPacketInfoAntiXray.getOrCreateIdForIndex(chunkSectionIndex));
+
+                    //Check if the chunk section below was not obfuscated
+                    if (chunkSectionIndex == 0 || !chunkPacketInfoAntiXray.isWritten(chunkSectionIndex - 1) || chunkPacketInfoAntiXray.getPredefinedObjects(chunkSectionIndex - 1) == null) {
+                        //If so, initialize some stuff
+                        dataBitsReader.setBitsPerObject(chunkPacketInfoAntiXray.getBitsPerObject(chunkSectionIndex));
+                        dataBitsReader.setIndex(chunkPacketInfoAntiXray.getOrCreateIdForIndex(chunkSectionIndex));
+                        solidTemp = readDataPalette(chunkPacketInfoAntiXray.getDataPalette(chunkSectionIndex), solid, solidGlobal);
+                        obfuscateTemp = readDataPalette(chunkPacketInfoAntiXray.getDataPalette(chunkSectionIndex), obfuscate, obfuscateGlobal);
+                        //Read the blocks of the upper layer of the chunk section below if it exists
+                        ChunkSection belowChunkSection = null;
+                        boolean skipFirstLayer = chunkSectionIndex == 0 || (belowChunkSection = chunkPacketInfoAntiXray.getChunk().getSections()[chunkSectionIndex - 1]) == Chunk.EMPTY_CHUNK_SECTION;
+
+                        for (int z = 0; z < 16; z++) {
+                            for (int x = 0; x < 16; x++) {
+                                current[z][x] = true;
+                                next[z][x] = skipFirstLayer || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(belowChunkSection.getType(x, 15, z))];
+                            }
+                        }
+
+                        //Abuse the obfuscateLayer method to read the blocks of the first layer of the current chunk section
+                        dataBitsWriter.setBitsPerObject(0);
+                        obfuscateLayer(-1, dataBitsReader, dataBitsWriter, solidTemp, obfuscateTemp, predefinedBlockDataBitsTemp, current, next, nextNext, emptyNearbyChunkSections, counter);
+                    }
+
+                    dataBitsWriter.setBitsPerObject(chunkPacketInfoAntiXray.getBitsPerObject(chunkSectionIndex));
+                    nearbyChunkSections[0] = chunkPacketInfoAntiXray.getNearbyChunks()[0] == null ? Chunk.EMPTY_CHUNK_SECTION : chunkPacketInfoAntiXray.getNearbyChunks()[0].getSections()[chunkSectionIndex];
+                    nearbyChunkSections[1] = chunkPacketInfoAntiXray.getNearbyChunks()[1] == null ? Chunk.EMPTY_CHUNK_SECTION : chunkPacketInfoAntiXray.getNearbyChunks()[1].getSections()[chunkSectionIndex];
+                    nearbyChunkSections[2] = chunkPacketInfoAntiXray.getNearbyChunks()[2] == null ? Chunk.EMPTY_CHUNK_SECTION : chunkPacketInfoAntiXray.getNearbyChunks()[2].getSections()[chunkSectionIndex];
+                    nearbyChunkSections[3] = chunkPacketInfoAntiXray.getNearbyChunks()[3] == null ? Chunk.EMPTY_CHUNK_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;
+                        counter = obfuscateLayer(y, dataBitsReader, dataBitsWriter, solidTemp, obfuscateTemp, predefinedBlockDataBitsTemp, current, next, nextNext, nearbyChunkSections, counter);
+                    }
+
+                    //Check if the chunk section above doesn't need obfuscation
+                    if (chunkSectionIndex == maxChunkSectionIndex || !chunkPacketInfoAntiXray.isWritten(chunkSectionIndex + 1) || chunkPacketInfoAntiXray.getPredefinedObjects(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
+                        ChunkSection aboveChunkSection;
+
+                        if (chunkSectionIndex != 15 && (aboveChunkSection = chunkPacketInfoAntiXray.getChunk().getSections()[chunkSectionIndex + 1]) != Chunk.EMPTY_CHUNK_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[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(aboveChunkSection.getType(x, 0, z))]) {
+                                        current[z][x] = true;
+                                    }
+                                }
+                            }
+
+                            //There is nothing to read anymore
+                            dataBitsReader.setBitsPerObject(0);
+                            solid[0] = true;
+                            counter = obfuscateLayer(15, dataBitsReader, dataBitsWriter, solid, obfuscateTemp, predefinedBlockDataBitsTemp, current, next, nextNext, nearbyChunkSections, counter);
+                        }
+                    } else {
+                        //If not, initialize the reader and other stuff for the chunk section above to obfuscate the upper layer of the current chunk section
+                        dataBitsReader.setBitsPerObject(chunkPacketInfoAntiXray.getBitsPerObject(chunkSectionIndex + 1));
+                        dataBitsReader.setIndex(chunkPacketInfoAntiXray.getOrCreateIdForIndex(chunkSectionIndex + 1));
+                        solidTemp = readDataPalette(chunkPacketInfoAntiXray.getDataPalette(chunkSectionIndex + 1), solid, solidGlobal);
+                        obfuscateTemp = readDataPalette(chunkPacketInfoAntiXray.getDataPalette(chunkSectionIndex + 1), obfuscate, obfuscateGlobal);
+                        boolean[][] temp = current;
+                        current = next;
+                        next = nextNext;
+                        nextNext = temp;
+                        counter = obfuscateLayer(15, dataBitsReader, dataBitsWriter, solidTemp, obfuscateTemp, predefinedBlockDataBitsTemp, current, next, nextNext, nearbyChunkSections, counter);
+                    }
+
+                    dataBitsWriter.finish();
+                }
+            }
+
+            chunkPacketInfoAntiXray.getPacketPlayOutMapChunk().setReady(true);
+
+        } finally {
+            if (chunkPacketInfoAntiXray.ticketHold != null) {
+                Runnable runnable = () -> {
+                    Chunk chunk = chunkPacketInfoAntiXray.getChunk();
+                    ChunkCoordIntPair chunkPos = chunk.getPos();
+
+                    ChunkPacketBlockControllerAntiXray.this.removeXrayTickets(chunkPos.x, chunkPos.z, (ChunkProviderServer) chunk.world.getChunkProvider(),
+                        chunkPacketInfoAntiXray.ticketHold);
+                };
+                if (MinecraftServer.getServer().isMainThread()) {
+                    runnable.run();
+                } else {
+                    MinecraftServer.getServer().scheduleOnMain(runnable);
+                }
+            }
+        }
+    }
+
+    private int obfuscateLayer(int y, DataBitsReader dataBitsReader, DataBitsWriter dataBitsWriter, boolean[] solid, boolean[] obfuscate, int[] predefinedBlockDataBits, boolean[][] current, boolean[][] next, boolean[][] nextNext, ChunkSection[] nearbyChunkSections, int counter) {
+        //First block of first line
+        int dataBits = dataBitsReader.read();
+
+        if (nextNext[0][0] = !solid[dataBits]) {
+            dataBitsWriter.skip();
+            next[0][1] = true;
+            next[1][0] = true;
+        } else {
+            if (nearbyChunkSections[2] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[2].getType(0, y, 15))] || nearbyChunkSections[0] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[0].getType(15, y, 0))] || current[0][0]) {
+                dataBitsWriter.skip();
+            } else {
+                if (counter >= predefinedBlockDataBits.length) {
+                    counter = 0;
+                }
+
+                dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+            }
+        }
+
+        if (!obfuscate[dataBits]) {
+            next[0][0] = true;
+        }
+
+        //First line
+        for (int x = 1; x < 15; x++) {
+            dataBits = dataBitsReader.read();
+
+            if (nextNext[0][x] = !solid[dataBits]) {
+                dataBitsWriter.skip();
+                next[0][x - 1] = true;
+                next[0][x + 1] = true;
+                next[1][x] = true;
+            } else {
+                if (nearbyChunkSections[2] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[2].getType(x, y, 15))] || current[0][x]) {
+                    dataBitsWriter.skip();
+                } else {
+                    if (counter >= predefinedBlockDataBits.length) {
+                        counter = 0;
+                    }
+
+                    dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+                }
+            }
+
+            if (!obfuscate[dataBits]) {
+                next[0][x] = true;
+            }
+        }
+
+        //Last block of first line
+        dataBits = dataBitsReader.read();
+
+        if (nextNext[0][15] = !solid[dataBits]) {
+            dataBitsWriter.skip();
+            next[0][14] = true;
+            next[1][15] = true;
+        } else {
+            if (nearbyChunkSections[2] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[2].getType(15, y, 15))] || nearbyChunkSections[1] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[1].getType(0, y, 0))] || current[0][15]) {
+                dataBitsWriter.skip();
+            } else {
+                if (counter >= predefinedBlockDataBits.length) {
+                    counter = 0;
+                }
+
+                dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+            }
+        }
+
+        if (!obfuscate[dataBits]) {
+            next[0][15] = true;
+        }
+
+        //All inner lines
+        for (int z = 1; z < 15; z++) {
+            //First block
+            dataBits = dataBitsReader.read();
+
+            if (nextNext[z][0] = !solid[dataBits]) {
+                dataBitsWriter.skip();
+                next[z][1] = true;
+                next[z - 1][0] = true;
+                next[z + 1][0] = true;
+            } else {
+                if (nearbyChunkSections[0] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[0].getType(15, y, z))] || current[z][0]) {
+                    dataBitsWriter.skip();
+                } else {
+                    if (counter >= predefinedBlockDataBits.length) {
+                        counter = 0;
+                    }
+
+                    dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+                }
+            }
+
+            if (!obfuscate[dataBits]) {
+                next[z][0] = true;
+            }
+
+            //All inner blocks
+            for (int x = 1; x < 15; x++) {
+                dataBits = dataBitsReader.read();
+
+                if (nextNext[z][x] = !solid[dataBits]) {
+                    dataBitsWriter.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]) {
+                        dataBitsWriter.skip();
+                    } else {
+                        if (counter >= predefinedBlockDataBits.length) {
+                            counter = 0;
+                        }
+
+                        dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+                    }
+                }
+
+                if (!obfuscate[dataBits]) {
+                    next[z][x] = true;
+                }
+            }
+
+            //Last block
+            dataBits = dataBitsReader.read();
+
+            if (nextNext[z][15] = !solid[dataBits]) {
+                dataBitsWriter.skip();
+                next[z][14] = true;
+                next[z - 1][15] = true;
+                next[z + 1][15] = true;
+            } else {
+                if (nearbyChunkSections[1] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[1].getType(0, y, z))] || current[z][15]) {
+                    dataBitsWriter.skip();
+                } else {
+                    if (counter >= predefinedBlockDataBits.length) {
+                        counter = 0;
+                    }
+
+                    dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+                }
+            }
+
+            if (!obfuscate[dataBits]) {
+                next[z][15] = true;
+            }
+        }
+
+        //First block of last line
+        dataBits = dataBitsReader.read();
+
+        if (nextNext[15][0] = !solid[dataBits]) {
+            dataBitsWriter.skip();
+            next[15][1] = true;
+            next[14][0] = true;
+        } else {
+            if (nearbyChunkSections[3] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[3].getType(0, y, 0))] || nearbyChunkSections[0] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[0].getType(15, y, 15))] || current[15][0]) {
+                dataBitsWriter.skip();
+            } else {
+                if (counter >= predefinedBlockDataBits.length) {
+                    counter = 0;
+                }
+
+                dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+            }
+        }
+
+        if (!obfuscate[dataBits]) {
+            next[15][0] = true;
+        }
+
+        //Last line
+        for (int x = 1; x < 15; x++) {
+            dataBits = dataBitsReader.read();
+
+            if (nextNext[15][x] = !solid[dataBits]) {
+                dataBitsWriter.skip();
+                next[15][x - 1] = true;
+                next[15][x + 1] = true;
+                next[14][x] = true;
+            } else {
+                if (nearbyChunkSections[3] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[3].getType(x, y, 0))] || current[15][x]) {
+                    dataBitsWriter.skip();
+                } else {
+                    if (counter >= predefinedBlockDataBits.length) {
+                        counter = 0;
+                    }
+
+                    dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+                }
+            }
+
+            if (!obfuscate[dataBits]) {
+                next[15][x] = true;
+            }
+        }
+
+        //Last block of last line
+        dataBits = dataBitsReader.read();
+
+        if (nextNext[15][15] = !solid[dataBits]) {
+            dataBitsWriter.skip();
+            next[15][14] = true;
+            next[14][15] = true;
+        } else {
+            if (nearbyChunkSections[3] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[3].getType(15, y, 0))] || nearbyChunkSections[1] == Chunk.EMPTY_CHUNK_SECTION || !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(nearbyChunkSections[1].getType(0, y, 15))] || current[15][15]) {
+                dataBitsWriter.skip();
+            } else {
+                if (counter >= predefinedBlockDataBits.length) {
+                    counter = 0;
+                }
+
+                dataBitsWriter.write(predefinedBlockDataBits[counter++]);
+            }
+        }
+
+        if (!obfuscate[dataBits]) {
+            next[15][15] = true;
+        }
+
+        return counter;
+    }
+
+    private boolean[] readDataPalette(DataPalette<IBlockData> dataPalette, boolean[] temp, boolean[] global) {
+        if (dataPalette == ChunkSection.GLOBAL_PALETTE) {
+            return global;
+        }
+
+        IBlockData blockData;
+
+        for (int i = 0; (blockData = dataPalette.getObject(i)) != null; i++) {
+            temp[i] = global[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(blockData)];
+        }
+
+        return temp;
+    }
+
+    @Override
+    public void onBlockChange(World world, BlockPosition blockPosition, IBlockData newBlockData, IBlockData oldBlockData, int flag) {
+        if (oldBlockData != null && solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(oldBlockData)] && !solidGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(newBlockData)] && blockPosition.getY() <= maxBlockYUpdatePosition) {
+            updateNearbyBlocks(world, blockPosition);
+        }
+    }
+
+    @Override
+    public void onPlayerLeftClickBlock(PlayerInteractManager playerInteractManager, BlockPosition blockPosition, EnumDirection enumDirection) {
+        if (blockPosition.getY() <= maxBlockYUpdatePosition) {
+            updateNearbyBlocks(playerInteractManager.world, blockPosition);
+        }
+    }
+
+    private void updateNearbyBlocks(World world, BlockPosition blockPosition) {
+        if (updateRadius >= 2) {
+            BlockPosition temp = blockPosition.west();
+            updateBlock(world, temp);
+            updateBlock(world, temp.west());
+            updateBlock(world, temp.down());
+            updateBlock(world, temp.up());
+            updateBlock(world, temp.north());
+            updateBlock(world, temp.south());
+            updateBlock(world, temp = blockPosition.east());
+            updateBlock(world, temp.east());
+            updateBlock(world, temp.down());
+            updateBlock(world, temp.up());
+            updateBlock(world, temp.north());
+            updateBlock(world, temp.south());
+            updateBlock(world, temp = blockPosition.down());
+            updateBlock(world, temp.down());
+            updateBlock(world, temp.north());
+            updateBlock(world, temp.south());
+            updateBlock(world, temp = blockPosition.up());
+            updateBlock(world, temp.up());
+            updateBlock(world, temp.north());
+            updateBlock(world, temp.south());
+            updateBlock(world, temp = blockPosition.north());
+            updateBlock(world, temp.north());
+            updateBlock(world, temp = blockPosition.south());
+            updateBlock(world, temp.south());
+        } else if (updateRadius == 1) {
+            updateBlock(world, blockPosition.west());
+            updateBlock(world, blockPosition.east());
+            updateBlock(world, blockPosition.down());
+            updateBlock(world, blockPosition.up());
+            updateBlock(world, blockPosition.north());
+            updateBlock(world, blockPosition.south());
+        } else {
+            //Do nothing if updateRadius <= 0 (test mode)
+        }
+    }
+
+    private void updateBlock(World world, BlockPosition blockPosition) {
+        IBlockData blockData = world.getTypeIfLoaded(blockPosition);
+
+        if (blockData != null && obfuscateGlobal[ChunkSection.GLOBAL_PALETTE.getOrCreateIdFor(blockData)]) {
+            //world.notify(blockPosition, blockData, blockData, 3);
+            ((WorldServer)world).getChunkProvider().flagDirty(blockPosition); // We only need to re-send to client
+        }
+    }
+
+    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;
+        }
+    }
+
+    public enum ChunkEdgeMode {
+
+        DEFAULT(1, "default"),
+        WAIT(2, "wait until nearby chunks are loaded"),
+        LOAD(3, "load nearby chunks");
+
+        private final int id;
+        private final String description;
+
+        ChunkEdgeMode(int id, String description) {
+            this.id = id;
+            this.description = description;
+        }
+
+        public static ChunkEdgeMode getById(int id) {
+            for (ChunkEdgeMode chunkEdgeMode : values()) {
+                if (chunkEdgeMode.id == id) {
+                    return chunkEdgeMode;
+                }
+            }
+
+            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 000000000..a68bace35
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfo.java
@@ -0,0 +1,81 @@
+package com.destroystokyo.paper.antixray;
+
+import net.minecraft.server.Chunk;
+import net.minecraft.server.DataPalette;
+import net.minecraft.server.PacketPlayOutMapChunk;
+
+public class ChunkPacketInfo<T> {
+
+    private final PacketPlayOutMapChunk packetPlayOutMapChunk;
+    private final Chunk chunk;
+    private final int chunkSectionSelector;
+    private byte[] data;
+    private final int[] bitsPerObject = new int[16];
+    private final Object[] dataPalettes = new Object[16];
+    private final int[] dataBitsIndexes = new int[16];
+    private final Object[][] predefinedObjects = new Object[16][];
+
+    public ChunkPacketInfo(PacketPlayOutMapChunk packetPlayOutMapChunk, Chunk chunk, int chunkSectionSelector) {
+        this.packetPlayOutMapChunk = packetPlayOutMapChunk;
+        this.chunk = chunk;
+        this.chunkSectionSelector = chunkSectionSelector;
+    }
+
+    public PacketPlayOutMapChunk getPacketPlayOutMapChunk() {
+        return packetPlayOutMapChunk;
+    }
+
+    public Chunk getChunk() {
+        return chunk;
+    }
+
+    public int getChunkSectionSelector() {
+        return chunkSectionSelector;
+    }
+
+    public byte[] getData() {
+        return data;
+    }
+
+    public void setData(byte[] data) {
+        this.data = data;
+    }
+
+    public int getBitsPerObject(int chunkSectionIndex) {
+        return bitsPerObject[chunkSectionIndex];
+    }
+
+    public void setBitsPerObject(int chunkSectionIndex, int bitsPerObject) {
+        this.bitsPerObject[chunkSectionIndex] = bitsPerObject;
+    }
+
+    @SuppressWarnings("unchecked")
+    public DataPalette<T> getDataPalette(int chunkSectionIndex) {
+        return (DataPalette<T>) dataPalettes[chunkSectionIndex];
+    }
+
+    public void setDataPalette(int chunkSectionIndex, DataPalette<T> dataPalette) {
+        dataPalettes[chunkSectionIndex] = dataPalette;
+    }
+
+    public int getOrCreateIdForIndex(int chunkSectionIndex) {
+        return dataBitsIndexes[chunkSectionIndex];
+    }
+
+    public void setDataBitsIndex(int chunkSectionIndex, int dataBitsIndex) {
+        dataBitsIndexes[chunkSectionIndex] = dataBitsIndex;
+    }
+
+    @SuppressWarnings("unchecked")
+    public T[] getPredefinedObjects(int chunkSectionIndex) {
+        return (T[]) predefinedObjects[chunkSectionIndex];
+    }
+
+    public void setPredefinedObjects(int chunkSectionIndex, T[] predefinedObjects) {
+        this.predefinedObjects[chunkSectionIndex] = predefinedObjects;
+    }
+
+    public boolean isWritten(int chunkSectionIndex) {
+        return bitsPerObject[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 000000000..067dfb2f1
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/ChunkPacketInfoAntiXray.java
@@ -0,0 +1,31 @@
+package com.destroystokyo.paper.antixray;
+
+import net.minecraft.server.Chunk;
+import net.minecraft.server.IBlockData;
+import net.minecraft.server.PacketPlayOutMapChunk;
+
+public class ChunkPacketInfoAntiXray extends ChunkPacketInfo<IBlockData> implements Runnable {
+
+    private Chunk[] nearbyChunks;
+    private final ChunkPacketBlockControllerAntiXray chunkPacketBlockControllerAntiXray;
+    public Integer ticketHold;
+
+    public ChunkPacketInfoAntiXray(PacketPlayOutMapChunk packetPlayOutMapChunk, Chunk chunk, int chunkSectionSelector,
+                                   ChunkPacketBlockControllerAntiXray chunkPacketBlockControllerAntiXray) {
+        super(packetPlayOutMapChunk, chunk, chunkSectionSelector);
+        this.chunkPacketBlockControllerAntiXray = chunkPacketBlockControllerAntiXray;
+    }
+
+    public Chunk[] getNearbyChunks() {
+        return nearbyChunks;
+    }
+
+    public void setNearbyChunks(Chunk... nearbyChunks) {
+        this.nearbyChunks = nearbyChunks;
+    }
+
+    @Override
+    public void run() {
+        chunkPacketBlockControllerAntiXray.obfuscate(this);
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/antixray/DataBitsReader.java b/src/main/java/com/destroystokyo/paper/antixray/DataBitsReader.java
new file mode 100644
index 000000000..cc586827a
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/DataBitsReader.java
@@ -0,0 +1,56 @@
+package com.destroystokyo.paper.antixray;
+
+public class DataBitsReader {
+
+    private byte[] dataBits;
+    private int bitsPerObject;
+    private int mask;
+    private int longInDataBitsIndex;
+    private int bitInLongIndex;
+    private long current;
+
+    public void setDataBits(byte[] dataBits) {
+        this.dataBits = dataBits;
+    }
+
+    public void setBitsPerObject(int bitsPerObject) {
+        this.bitsPerObject = bitsPerObject;
+        mask = (1 << bitsPerObject) - 1;
+    }
+
+    public void setIndex(int index) {
+        this.longInDataBitsIndex = index;
+        bitInLongIndex = 0;
+        init();
+    }
+
+    private void init() {
+        if (dataBits.length > longInDataBitsIndex + 7) {
+            current = ((((long) dataBits[longInDataBitsIndex]) << 56)
+                    | (((long) dataBits[longInDataBitsIndex + 1] & 0xff) << 48)
+                    | (((long) dataBits[longInDataBitsIndex + 2] & 0xff) << 40)
+                    | (((long) dataBits[longInDataBitsIndex + 3] & 0xff) << 32)
+                    | (((long) dataBits[longInDataBitsIndex + 4] & 0xff) << 24)
+                    | (((long) dataBits[longInDataBitsIndex + 5] & 0xff) << 16)
+                    | (((long) dataBits[longInDataBitsIndex + 6] & 0xff) << 8)
+                    | (((long) dataBits[longInDataBitsIndex + 7] & 0xff)));
+        }
+    }
+
+    public int read() {
+        int value = (int) (current >>> bitInLongIndex) & mask;
+        bitInLongIndex += bitsPerObject;
+
+        if (bitInLongIndex > 63) {
+            bitInLongIndex -= 64;
+            longInDataBitsIndex += 8;
+            init();
+
+            if (bitInLongIndex > 0) {
+                value |= current << bitsPerObject - bitInLongIndex & mask;
+            }
+        }
+
+        return value;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/antixray/DataBitsWriter.java b/src/main/java/com/destroystokyo/paper/antixray/DataBitsWriter.java
new file mode 100644
index 000000000..37093419c
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/antixray/DataBitsWriter.java
@@ -0,0 +1,84 @@
+package com.destroystokyo.paper.antixray;
+
+public class DataBitsWriter {
+
+    private byte[] dataBits;
+    private int bitsPerObject;
+    private long mask;
+    private int longInDataBitsIndex;
+    private int bitInLongIndex;
+    private long current;
+    private boolean dirty;
+
+    public void setDataBits(byte[] dataBits) {
+        this.dataBits = dataBits;
+    }
+
+    public void setBitsPerObject(int bitsPerObject) {
+        this.bitsPerObject = bitsPerObject;
+        mask = (1 << bitsPerObject) - 1;
+    }
+
+    public void setIndex(int index) {
+        this.longInDataBitsIndex = index;
+        bitInLongIndex = 0;
+        init();
+    }
+
+    private void init() {
+        if (dataBits.length > longInDataBitsIndex + 7) {
+            current = ((((long) dataBits[longInDataBitsIndex]) << 56)
+                    | (((long) dataBits[longInDataBitsIndex + 1] & 0xff) << 48)
+                    | (((long) dataBits[longInDataBitsIndex + 2] & 0xff) << 40)
+                    | (((long) dataBits[longInDataBitsIndex + 3] & 0xff) << 32)
+                    | (((long) dataBits[longInDataBitsIndex + 4] & 0xff) << 24)
+                    | (((long) dataBits[longInDataBitsIndex + 5] & 0xff) << 16)
+                    | (((long) dataBits[longInDataBitsIndex + 6] & 0xff) << 8)
+                    | (((long) dataBits[longInDataBitsIndex + 7] & 0xff)));
+        }
+
+        dirty = false;
+    }
+
+    public void finish() {
+        if (dirty && dataBits.length > longInDataBitsIndex + 7) {
+            dataBits[longInDataBitsIndex] = (byte) (current >> 56 & 0xff);
+            dataBits[longInDataBitsIndex + 1] = (byte) (current >> 48 & 0xff);
+            dataBits[longInDataBitsIndex + 2] = (byte) (current >> 40 & 0xff);
+            dataBits[longInDataBitsIndex + 3] = (byte) (current >> 32 & 0xff);
+            dataBits[longInDataBitsIndex + 4] = (byte) (current >> 24 & 0xff);
+            dataBits[longInDataBitsIndex + 5] = (byte) (current >> 16 & 0xff);
+            dataBits[longInDataBitsIndex + 6] = (byte) (current >> 8 & 0xff);
+            dataBits[longInDataBitsIndex + 7] = (byte) (current & 0xff);
+        }
+    }
+
+    public void write(int value) {
+        current = current & ~(mask << bitInLongIndex) | (value & mask) << bitInLongIndex;
+        dirty = true;
+        bitInLongIndex += bitsPerObject;
+
+        if (bitInLongIndex > 63) {
+            finish();
+            bitInLongIndex -= 64;
+            longInDataBitsIndex += 8;
+            init();
+
+            if (bitInLongIndex > 0) {
+                current = current & ~(mask >>> bitsPerObject - bitInLongIndex) | (value & mask) >>> bitsPerObject - bitInLongIndex;
+                dirty = true;
+            }
+        }
+    }
+
+    public void skip() {
+        bitInLongIndex += bitsPerObject;
+
+        if (bitInLongIndex > 63) {
+            finish();
+            bitInLongIndex -= 64;
+            longInDataBitsIndex += 8;
+            init();
+        }
+    }
+}
diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index 14ec31f0a..863a2222f 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -315,7 +315,7 @@ public class Chunk implements IChunkAccess {
                 return null;
             }
 
-            chunksection = new ChunkSection(j >> 4 << 4);
+            chunksection = new ChunkSection(j >> 4 << 4, this, this.world, true); // Paper - Anti-Xray
             this.sections[j >> 4] = chunksection;
         }
 
diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
index 961228e9d..a950ad801 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -57,7 +57,7 @@ public class ChunkRegionLoader {
             byte b0 = nbttagcompound2.getByte("Y");
 
             if (nbttagcompound2.hasKeyOfType("Palette", 9) && nbttagcompound2.hasKeyOfType("BlockStates", 12)) {
-                ChunkSection chunksection = new ChunkSection(b0 << 4);
+                ChunkSection chunksection = new ChunkSection(b0 << 4, null, worldserver, false); // Paper - Anti-Xray
 
                 chunksection.getBlocks().a(nbttagcompound2.getList("Palette", 10), nbttagcompound2.getLongArray("BlockStates"));
                 chunksection.recalcBlockCounts();
@@ -115,7 +115,7 @@ public class ChunkRegionLoader {
                 loadEntities(nbttagcompound1, chunk);
             });
         } else {
-            ProtoChunk protochunk = new ProtoChunk(chunkcoordintpair, chunkconverter, achunksection, protochunkticklist, protochunkticklist1);
+            ProtoChunk protochunk = new ProtoChunk(chunkcoordintpair, chunkconverter, achunksection, protochunkticklist, protochunkticklist1, worldserver); // Paper - Anti-Xray
 
             protochunk.a(biomestorage);
             object = protochunk;
diff --git a/src/main/java/net/minecraft/server/ChunkSection.java b/src/main/java/net/minecraft/server/ChunkSection.java
index 0d5deee36..4526527ac 100644
--- a/src/main/java/net/minecraft/server/ChunkSection.java
+++ b/src/main/java/net/minecraft/server/ChunkSection.java
@@ -6,21 +6,31 @@ public class ChunkSection {
 
     public static final DataPalette<IBlockData> GLOBAL_PALETTE = new DataPaletteGlobal<>(Block.REGISTRY_ID, Blocks.AIR.getBlockData());
     private final int yPos;
-    private short nonEmptyBlockCount;
+    short nonEmptyBlockCount; // Paper - private -> package-private
     private short tickingBlockCount;
     private short e;
     final DataPaletteBlock<IBlockData> blockIds;
 
     public ChunkSection(int i) {
-        this(i, (short) 0, (short) 0, (short) 0);
+        // Paper start - add parameters
+        this(i, (IChunkAccess)null, (IWorldReader)null, true);
+    }
+    public ChunkSection(int i, IChunkAccess chunk, IWorldReader world, boolean initializeBlocks) {
+        this(i, (short) 0, (short) 0, (short) 0, chunk, world, initializeBlocks);
+        // Paper end
     }
 
     public ChunkSection(int i, short short0, short short1, short short2) {
+        // Paper start - add parameters
+        this(i, short0, short1, short2, (IChunkAccess)null, (IWorldReader)null, true);
+    }
+    public ChunkSection(int i, short short0, short short1, short short2, IChunkAccess chunk, IWorldReader world, boolean initializeBlocks) {
+        // Paper end
         this.yPos = i;
         this.nonEmptyBlockCount = short0;
         this.tickingBlockCount = short1;
         this.e = short2;
-        this.blockIds = new DataPaletteBlock<>(ChunkSection.GLOBAL_PALETTE, Block.REGISTRY_ID, GameProfileSerializer::d, GameProfileSerializer::a, Blocks.AIR.getBlockData());
+        this.blockIds = new DataPaletteBlock<>(ChunkSection.GLOBAL_PALETTE, Block.REGISTRY_ID, GameProfileSerializer::d, GameProfileSerializer::a, Blocks.AIR.getBlockData(), world instanceof GeneratorAccess ? ((GeneratorAccess) world).getMinecraftWorld().chunkPacketBlockController.getPredefinedBlockData(world, chunk, this, initializeBlocks) : null, initializeBlocks); // Paper - Anti-Xray - Add predefined block data
     }
 
     public IBlockData getType(int i, int j, int k) {
diff --git a/src/main/java/net/minecraft/server/DataPaletteBlock.java b/src/main/java/net/minecraft/server/DataPaletteBlock.java
index 2c1d1b1a5..44aed6727 100644
--- a/src/main/java/net/minecraft/server/DataPaletteBlock.java
+++ b/src/main/java/net/minecraft/server/DataPaletteBlock.java
@@ -3,6 +3,7 @@ package net.minecraft.server;
 import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
 import it.unimi.dsi.fastutil.ints.Int2IntMap.Entry;
+import com.destroystokyo.paper.antixray.ChunkPacketInfo; // Paper - Anti-Xray
 import java.util.Arrays;
 import java.util.Objects;
 import java.util.concurrent.locks.ReentrantLock;
@@ -19,6 +20,7 @@ public class DataPaletteBlock<T> implements DataPaletteExpandable<T> {
     private final Function<NBTTagCompound, T> e;
     private final Function<T, NBTTagCompound> f;
     private final T g;
+    private final T[] predefinedObjects; // Paper - Anti-Xray - Add predefined objects
     protected DataBits a; protected DataBits getDataBits() { return this.a; } // Paper - OBFHELPER
     private DataPalette<T> h; private DataPalette<T> getDataPalette() { return this.h; } // Paper - OBFHELPER
     private int i; private int getBitsPerObject() { return this.i; } // Paper - OBFHELPER
@@ -47,14 +49,50 @@ public class DataPaletteBlock<T> implements DataPaletteExpandable<T> {
     }
 
     public DataPaletteBlock(DataPalette<T> datapalette, RegistryBlockID<T> registryblockid, Function<NBTTagCompound, T> function, Function<T, NBTTagCompound> function1, T t0) {
+        // Paper start - Anti-Xray - Support default constructor
+        this(datapalette, registryblockid, function, function1, t0, null, true);
+    }
+
+    public DataPaletteBlock(DataPalette<T> datapalette, RegistryBlockID<T> registryblockid, Function<NBTTagCompound, T> function, Function<T, NBTTagCompound> function1, T t0, T[] predefinedObjects, boolean initialize) {
+        // Paper end - Anti-Xray - Add predefined objects
         this.b = datapalette;
         this.d = registryblockid;
         this.e = function;
         this.f = function1;
         this.g = t0;
-        this.b(4);
+        // Paper start - Anti-Xray - Add predefined objects
+        this.predefinedObjects = predefinedObjects;
+
+        if (initialize) {
+            if (predefinedObjects == null) {
+                // Default
+                this.initialize(4);
+            } else {
+                // MathHelper.d() is trailingBits(roundCeilPow2(n)), alternatively; (int)ceil(log2(n)); however it's trash, use numberOfLeadingZeros instead
+                // Count the bits of the maximum array index to initialize a data palette with enough space from the beginning
+                // The length of the array is used because air is also added to the data palette from the beginning
+                // Start with at least 4
+                int maxIndex = predefinedObjects.length >> 4;
+                int bitCount = (32 - Integer.numberOfLeadingZeros(Math.max(16, maxIndex) - 1));
+
+                // Initialize with at least 15 free indixes
+                this.initialize((1 << bitCount) - predefinedObjects.length < 16 ? bitCount + 1 : bitCount);
+                this.addPredefinedObjects();
+            }
+        }
+        // Paper end
     }
 
+    // Paper start - Anti-Xray - Add predefined objects
+    private void addPredefinedObjects() {
+        if (this.predefinedObjects != null && this.getDataPalette() != this.getDataPaletteGlobal()) {
+            for (int i = 0; i < this.predefinedObjects.length; i++) {
+                this.getDataPalette().getOrCreateIdFor(this.predefinedObjects[i]);
+            }
+        }
+    }
+    // Paper end
+
     private static int b(int i, int j, int k) {
         return j << 8 | k << 4 | i;
     }
@@ -88,6 +126,7 @@ public class DataPaletteBlock<T> implements DataPaletteExpandable<T> {
 
         int j;
 
+        this.addPredefinedObjects(); // Paper - Anti-Xray - Add predefined objects
         for (j = 0; j < databits.b(); ++j) {
             T t1 = datapalette.a(databits.a(j));
 
@@ -139,22 +178,39 @@ public class DataPaletteBlock<T> implements DataPaletteExpandable<T> {
 
     public void writeDataPaletteBlock(PacketDataSerializer packetDataSerializer) { this.b(packetDataSerializer); } // Paper - OBFHELPER
     public void b(PacketDataSerializer packetdataserializer) {
+        // Paper start - add parameters
+        this.writeDataPaletteBlock(packetdataserializer, null, 0);
+    }
+    public void writeDataPaletteBlock(PacketDataSerializer packetdataserializer, ChunkPacketInfo<T> chunkPacketInfo, int chunkSectionIndex) {
+        // Paper end
         this.a();
         packetdataserializer.writeByte(this.i);
         this.h.b(packetdataserializer);
+
+        // Paper start - Anti-Xray - Add chunk packet info
+        if (chunkPacketInfo != null) {
+            chunkPacketInfo.setBitsPerObject(chunkSectionIndex, this.getBitsPerObject());
+            chunkPacketInfo.setDataPalette(chunkSectionIndex, this.getDataPalette());
+            chunkPacketInfo.setDataBitsIndex(chunkSectionIndex, packetdataserializer.writerIndex() + PacketDataSerializer.countBytes(this.getDataBits().getDataBits().length));
+            chunkPacketInfo.setPredefinedObjects(chunkSectionIndex, this.predefinedObjects);
+        }
+        // Paper end
+
         packetdataserializer.a(this.a.a());
         this.b();
     }
 
     public void a(NBTTagList nbttaglist, long[] along) {
         this.a();
-        int i = Math.max(4, MathHelper.d(nbttaglist.size()));
+        // Paper - Anti-Xray - TODO: Should this.predefinedObjects.length just be added here (faster) or should the contents be compared to calculate the size (less RAM)?
+        int i = Math.max(4, MathHelper.d(nbttaglist.size() + (this.predefinedObjects == null ? 0 : this.predefinedObjects.length))); // Paper - Anti-Xray - Calculate the size with predefined objects
 
-        if (i != this.i) {
+        if (true || i != this.i) { // Paper - Anti-Xray - Not initialized yet
             this.b(i);
         }
 
         this.h.a(nbttaglist);
+        this.addPredefinedObjects(); // Paper - Anti-Xray - Add predefined objects
         int j = along.length * 64 / 4096;
 
         if (this.h == this.b) {
diff --git a/src/main/java/net/minecraft/server/NetworkManager.java b/src/main/java/net/minecraft/server/NetworkManager.java
index e156804f7..96a785af2 100644
--- a/src/main/java/net/minecraft/server/NetworkManager.java
+++ b/src/main/java/net/minecraft/server/NetworkManager.java
@@ -42,7 +42,7 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
         return new DefaultEventLoopGroup(0, (new ThreadFactoryBuilder()).setNameFormat("Netty Local Client IO #%d").setDaemon(true).build());
     });
     private final EnumProtocolDirection h;
-    private final Queue<NetworkManager.QueuedPacket> packetQueue = Queues.newConcurrentLinkedQueue();
+    private final Queue<NetworkManager.QueuedPacket> packetQueue = Queues.newConcurrentLinkedQueue(); private final Queue<NetworkManager.QueuedPacket> getPacketQueue() { return this.packetQueue; } // Paper - OBFHELPER
     public Channel channel;
     public SocketAddress socketAddress; public void setSpoofedRemoteAddress(SocketAddress address) { this.socketAddress = address; } // Paper - OBFHELPER
     // Spigot Start
@@ -164,8 +164,8 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
     }
 
     public void sendPacket(Packet<?> packet, @Nullable GenericFutureListener<? extends Future<? super Void>> genericfuturelistener) {
-        if (this.isConnected()) {
-            this.o();
+        if (this.isConnected() && this.sendPacketQueue() && !(packet instanceof PacketPlayOutMapChunk && !((PacketPlayOutMapChunk) packet).isReady())) { // Paper - Async-Anti-Xray - Add chunk packets which are not ready or all packets if the packet queue contains chunk packets which are not ready to the packet queue and send the packets later in the right order
+            //this.o(); // Paper - Async-Anti-Xray - Move to if statement (this.sendPacketQueue())
             this.b(packet, genericfuturelistener);
         } else {
             this.packetQueue.add(new NetworkManager.QueuedPacket(packet, genericfuturelistener));
@@ -223,21 +223,32 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
 
     }
 
-    private void sendPacketQueue() { this.o(); } // Paper - OBFHELPER
-    private void o() {
+    // Paper start - Async-Anti-Xray - Stop dispatching further packets and return false if the peeked packet is a chunk packet which is not ready
+    private boolean sendPacketQueue() { return this.o(); } // OBFHELPER // void -> boolean
+    private boolean o() { // void -> boolean
         if (this.channel != null && this.channel.isOpen()) {
             Queue queue = this.packetQueue;
 
             synchronized (this.packetQueue) {
-                NetworkManager.QueuedPacket networkmanager_queuedpacket;
-
-                while ((networkmanager_queuedpacket = (NetworkManager.QueuedPacket) this.packetQueue.poll()) != null) {
-                    this.b(networkmanager_queuedpacket.a, networkmanager_queuedpacket.b);
+                while (!this.packetQueue.isEmpty()) {
+                    NetworkManager.QueuedPacket networkmanager_queuedpacket = (NetworkManager.QueuedPacket) this.getPacketQueue().peek(); // poll -> peek
+
+                    if (networkmanager_queuedpacket != null) { // Fix NPE (Spigot bug caused by handleDisconnection())
+                        if (networkmanager_queuedpacket.getPacket() instanceof PacketPlayOutMapChunk && !((PacketPlayOutMapChunk) networkmanager_queuedpacket.getPacket()).isReady()) { // Check if the peeked packet is a chunk packet which is not ready
+                            return false; // Return false if the peeked packet is a chunk packet which is not ready
+                        } else {
+                            this.getPacketQueue().poll(); // poll here
+                            this.dispatchPacket(networkmanager_queuedpacket.getPacket(), networkmanager_queuedpacket.getGenericFutureListener()); // dispatch the packet
+                        }
+                    }
                 }
 
             }
         }
+
+        return true; // Return true if all packets were dispatched
     }
+    // Paper end
 
     public void a() {
         this.o();
diff --git a/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java b/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java
index 47710067a..ef7ade797 100644
--- a/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java
+++ b/src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java
@@ -1,5 +1,6 @@
 package net.minecraft.server;
 
+import com.destroystokyo.paper.antixray.ChunkPacketInfo; // Paper - Anti-Xray
 import com.google.common.collect.Lists;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
@@ -20,8 +21,11 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
     private byte[] f; private byte[] getData() { return this.f; } // Paper - OBFHELPER
     private List<NBTTagCompound> g;
     private boolean h;
+    private volatile boolean ready; // Paper - Async-Anti-Xray - Ready flag for the network manager
 
-    public PacketPlayOutMapChunk() {}
+    public PacketPlayOutMapChunk() {
+        this.ready = true; // Paper - Async-Anti-Xray - Set the ready flag to true
+    }
 
     // Paper start
     private final java.util.List<Packet> extraPackets = new java.util.ArrayList<>();
@@ -33,6 +37,12 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
     }
     // Paper end
     public PacketPlayOutMapChunk(Chunk chunk, int i) {
+        // Paper start - add forceLoad param
+        this(chunk, i, false);
+    }
+    public PacketPlayOutMapChunk(Chunk chunk, int i, boolean forceLoad) {
+        // Paper end
+        ChunkPacketInfo<IBlockData> chunkPacketInfo = chunk.world.chunkPacketBlockController.getChunkPacketInfo(this, chunk, i, forceLoad); // Paper - Anti-Xray - Add chunk packet info
         ChunkCoordIntPair chunkcoordintpair = chunk.getPos();
 
         this.a = chunkcoordintpair.x;
@@ -55,7 +65,12 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
         }
 
         this.f = new byte[this.a(chunk, i)];
-        this.c = this.a(new PacketDataSerializer(this.j()), chunk, i);
+        // Paper start - Anti-Xray - Add chunk packet info
+        if (chunkPacketInfo != null) {
+            chunkPacketInfo.setData(this.getData());
+        }
+        // Paper end
+        this.c = this.writeChunk(new PacketDataSerializer(this.j()), chunk, i, chunkPacketInfo); // Paper - Anti-Xray - Add chunk packet info
         this.g = Lists.newArrayList();
         iterator = chunk.getTileEntities().entrySet().iterator();
         int totalSigns = 0; // Paper
@@ -81,9 +96,19 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
                 this.g.add(nbttagcompound);
             }
         }
+        chunk.world.chunkPacketBlockController.modifyBlocks(this, chunkPacketInfo, forceLoad, null); // Paper - Anti-Xray - Modify blocks
+    }
 
+    // Paper start - Async-Anti-Xray - Getter and Setter for the ready flag
+    public boolean isReady() {
+        return this.ready;
     }
 
+    public void setReady(boolean ready) {
+        this.ready = ready;
+    }
+    // Paper end
+
     @Override
     public void a(PacketDataSerializer packetdataserializer) throws IOException {
         this.a = packetdataserializer.readInt();
@@ -150,6 +175,11 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
 
     public int writeChunk(PacketDataSerializer packetDataSerializer, Chunk chunk, int chunkSectionSelector) { return this.a(packetDataSerializer, chunk, chunkSectionSelector); } // Paper - OBFHELPER
     public int a(PacketDataSerializer packetdataserializer, Chunk chunk, int i) {
+        // Paper start - Add parameter
+        return this.writeChunk(packetdataserializer, chunk, i, null);
+    }
+    public int writeChunk(PacketDataSerializer packetdataserializer, Chunk chunk, int i, ChunkPacketInfo<IBlockData> chunkPacketInfo) {
+        // Paper end
         int j = 0;
         ChunkSection[] achunksection = chunk.getSections();
         int k = 0;
@@ -159,7 +189,8 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
 
             if (chunksection != Chunk.a && (!this.f() || !chunksection.c()) && (i & 1 << k) != 0) {
                 j |= 1 << k;
-                chunksection.b(packetdataserializer);
+                packetdataserializer.writeShort(chunksection.nonEmptyBlockCount); // Paper - Anti-Xray - Add chunk packet info
+                chunksection.getBlocks().writeDataPaletteBlock(packetdataserializer, chunkPacketInfo, k); // Paper - Anti-Xray - Add chunk packet info
             }
         }
 
diff --git a/src/main/java/net/minecraft/server/PlayerChunk.java b/src/main/java/net/minecraft/server/PlayerChunk.java
index 6f2cca07e..7a1578afa 100644
--- a/src/main/java/net/minecraft/server/PlayerChunk.java
+++ b/src/main/java/net/minecraft/server/PlayerChunk.java
@@ -176,6 +176,11 @@ public class PlayerChunk {
             World world = chunk.getWorld();
 
             if (this.dirtyCount == 64) {
+                // Paper start - Anti-Xray - Load nearby chunks if necessary
+                if (!chunk.world.chunkPacketBlockController.onChunkPacketCreate(chunk, '\uffff', false)) {
+                    return;
+                }
+                // Paper end
                 this.s = -1;
             }
 
@@ -208,7 +213,7 @@ public class PlayerChunk {
                     this.a(world, blockposition);
                 }
             } else if (this.dirtyCount == 64) {
-                this.a(new PacketPlayOutMapChunk(chunk, this.r), false);
+                this.a(new PacketPlayOutMapChunk(chunk, this.r, true), false); // Paper - Anti-Xray
             } else if (this.dirtyCount != 0) {
                 this.a(new PacketPlayOutMultiBlockChange(this.dirtyCount, this.dirtyBlocks, chunk), false);
 
diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
index cbab813d9..6a54ccb86 100644
--- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
@@ -540,7 +540,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
                 PlayerChunkMap.LOGGER.error("Couldn't load chunk {}", chunkcoordintpair, exception);
             }
 
-            return Either.left(new ProtoChunk(chunkcoordintpair, ChunkConverter.a));
+            return Either.left(new ProtoChunk(chunkcoordintpair, ChunkConverter.a, this.world)); // Paper - Anti-Xray
         }, this.executor);
     }
 
@@ -1251,7 +1251,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
 
     private void a(EntityPlayer entityplayer, Packet<?>[] apacket, Chunk chunk) {
         if (apacket[0] == null) {
-            apacket[0] = new PacketPlayOutMapChunk(chunk, 65535);
+            apacket[0] = new PacketPlayOutMapChunk(chunk, 65535, true); // Paper - Anti-Xray
             apacket[1] = new PacketPlayOutLightUpdate(chunk.getPos(), this.lightEngine);
         }
 
diff --git a/src/main/java/net/minecraft/server/PlayerInteractManager.java b/src/main/java/net/minecraft/server/PlayerInteractManager.java
index 18ff6dd68..8720dd120 100644
--- a/src/main/java/net/minecraft/server/PlayerInteractManager.java
+++ b/src/main/java/net/minecraft/server/PlayerInteractManager.java
@@ -264,6 +264,8 @@ public class PlayerInteractManager {
             }
 
         }
+
+        this.world.chunkPacketBlockController.onPlayerLeftClickBlock(this, blockposition, enumdirection); // Paper - Anti-Xray
     }
 
     public void a(BlockPosition blockposition, PacketPlayInBlockDig.EnumPlayerDigType packetplayinblockdig_enumplayerdigtype, String s) {
diff --git a/src/main/java/net/minecraft/server/ProtoChunk.java b/src/main/java/net/minecraft/server/ProtoChunk.java
index 39339fa27..f376e2106 100644
--- a/src/main/java/net/minecraft/server/ProtoChunk.java
+++ b/src/main/java/net/minecraft/server/ProtoChunk.java
@@ -45,16 +45,28 @@ public class ProtoChunk implements IChunkAccess {
     private long s;
     private final Map<WorldGenStage.Features, BitSet> t;
     private volatile boolean u;
+    private final GeneratorAccess world; // Paper - Anti-Xray
 
     public ProtoChunk(ChunkCoordIntPair chunkcoordintpair, ChunkConverter chunkconverter) {
+        // Paper start - add world parameter
+        this(chunkcoordintpair, chunkconverter, (GeneratorAccess)null);
+    }
+    public ProtoChunk(ChunkCoordIntPair chunkcoordintpair, ChunkConverter chunkconverter, GeneratorAccess world) {
+        // Paper end
         this(chunkcoordintpair, chunkconverter, (ChunkSection[]) null, new ProtoChunkTickList<>((block) -> {
             return block == null || block.getBlockData().isAir();
         }, chunkcoordintpair), new ProtoChunkTickList<>((fluidtype) -> {
             return fluidtype == null || fluidtype == FluidTypes.EMPTY;
-        }, chunkcoordintpair));
+        }, chunkcoordintpair), world); // Paper - add world parameter
     }
 
     public ProtoChunk(ChunkCoordIntPair chunkcoordintpair, ChunkConverter chunkconverter, @Nullable ChunkSection[] achunksection, ProtoChunkTickList<Block> protochunkticklist, ProtoChunkTickList<FluidType> protochunkticklist1) {
+        // Paper start - add world parameter
+        this(chunkcoordintpair, chunkconverter, achunksection, protochunkticklist, protochunkticklist1, (GeneratorAccess)null);
+    }
+    public ProtoChunk(ChunkCoordIntPair chunkcoordintpair, ChunkConverter chunkconverter, @Nullable ChunkSection[] achunksection, ProtoChunkTickList<Block> protochunkticklist, ProtoChunkTickList<FluidType> protochunkticklist1, GeneratorAccess world) {
+        this.world = world;
+        // Paper end
         this.f = Maps.newEnumMap(HeightMap.Type.class);
         this.g = ChunkStatus.EMPTY;
         this.h = Maps.newHashMap();
@@ -207,7 +219,7 @@ public class ProtoChunk implements IChunkAccess {
 
     public ChunkSection a(int i) {
         if (this.j[i] == Chunk.a) {
-            this.j[i] = new ChunkSection(i << 4);
+            this.j[i] = new ChunkSection(i << 4, this, this.world, true); // Paper - Anti-Xray
         }
 
         return this.j[i];
diff --git a/src/main/java/net/minecraft/server/TicketType.java b/src/main/java/net/minecraft/server/TicketType.java
index a905a29e7..335b64435 100644
--- a/src/main/java/net/minecraft/server/TicketType.java
+++ b/src/main/java/net/minecraft/server/TicketType.java
@@ -21,6 +21,7 @@ public class TicketType<T> {
     public static final TicketType<ChunkCoordIntPair> UNKNOWN = a("unknown", Comparator.comparingLong(ChunkCoordIntPair::pair), 1);
     public static final TicketType<Unit> PLUGIN = a("plugin", (a, b) -> 0); // CraftBukkit
     public static final TicketType<org.bukkit.plugin.Plugin> PLUGIN_TICKET = a("plugin_ticket", (plugin1, plugin2) -> plugin1.getClass().getName().compareTo(plugin2.getClass().getName())); // Craftbukkit
+    public static final TicketType<Integer> ANTIXRAY = a("antixray", Integer::compareTo); // Paper - Anti-Xray
 
     public static <T> TicketType<T> a(String s, Comparator<T> comparator) {
         return new TicketType<>(s, comparator, 0L);
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index e80cb3b97..985f30372 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -2,6 +2,8 @@ package net.minecraft.server;
 
 import co.aikar.timings.Timing;
 import co.aikar.timings.Timings;
+import com.destroystokyo.paper.antixray.ChunkPacketBlockController; // Paper - Anti-Xray
+import com.destroystokyo.paper.antixray.ChunkPacketBlockControllerAntiXray; // Paper - Anti-Xray
 import com.destroystokyo.paper.event.server.ServerExceptionEvent;
 import com.destroystokyo.paper.exception.ServerInternalException;
 import com.google.common.base.MoreObjects;
@@ -92,6 +94,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
     public final org.spigotmc.SpigotWorldConfig spigotConfig; // Spigot
 
     public final com.destroystokyo.paper.PaperWorldConfig paperConfig; // Paper
+    public final ChunkPacketBlockController chunkPacketBlockController; // Paper - Anti-Xray
 
     public final co.aikar.timings.WorldTimingsHandler timings; // Paper
     public static BlockPosition lastPhysicsProblem; // Spigot
@@ -133,6 +136,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
     protected World(WorldData worlddata, DimensionManager dimensionmanager, BiFunction<World, WorldProvider, IChunkProvider> bifunction, GameProfilerFiller gameprofilerfiller, boolean flag, org.bukkit.generator.ChunkGenerator gen, org.bukkit.World.Environment env) {
         this.spigotConfig = new org.spigotmc.SpigotWorldConfig( worlddata.getName() ); // Spigot
         this.paperConfig = new com.destroystokyo.paper.PaperWorldConfig(worlddata.getName(), this.spigotConfig); // Paper
+        this.chunkPacketBlockController = this.paperConfig.antiXray ? new ChunkPacketBlockControllerAntiXray(this.paperConfig) : ChunkPacketBlockController.NO_OPERATION_INSTANCE; // Paper - Anti-Xray
         this.generator = gen;
         this.world = new CraftWorld((WorldServer) this, gen, env);
         this.ticksPerAnimalSpawns = this.getServer().getTicksPerAnimalSpawns(); // CraftBukkit
@@ -358,6 +362,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
             // CraftBukkit end
 
             IBlockData iblockdata1 = chunk.setType(blockposition, iblockdata, (i & 64) != 0, (i & 1024) == 0); // CraftBukkit custom NO_PLACE flag
+            this.chunkPacketBlockController.onBlockChange(this, blockposition, iblockdata, iblockdata1, i); // Paper - Anti-Xray
 
             if (iblockdata1 == null) {
                 // CraftBukkit start - remove blockstate if failed
diff --git a/src/main/java/org/bukkit/craftbukkit/generator/CraftChunkData.java b/src/main/java/org/bukkit/craftbukkit/generator/CraftChunkData.java
index 7772d5900..4570ed999 100644
--- a/src/main/java/org/bukkit/craftbukkit/generator/CraftChunkData.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/CraftChunkData.java
@@ -21,9 +21,11 @@ public final class CraftChunkData implements ChunkGenerator.ChunkData {
     private final int maxHeight;
     private final ChunkSection[] sections;
     private Set<BlockPosition> tiles;
+    private World world; // Paper - Anti-Xray
 
     public CraftChunkData(World world) {
         this(world.getMaxHeight());
+        this.world = world; // Paper - Anti-Xray
     }
 
     /* pp for tests */ CraftChunkData(int maxHeight) {
@@ -157,7 +159,7 @@ public final class CraftChunkData implements ChunkGenerator.ChunkData {
     private ChunkSection getChunkSection(int y, boolean create) {
         ChunkSection section = sections[y >> 4];
         if (create && section == null) {
-            sections[y >> 4] = section = new ChunkSection(y);
+            sections[y >> 4] = section = new ChunkSection(y, null, world instanceof org.bukkit.craftbukkit.CraftWorld ? ((org.bukkit.craftbukkit.CraftWorld) world).getHandle() : null, true); // Paper - Anti-Xray
         }
         return section;
     }
-- 
2.24.1