Support annotations, add more restrictions, improve version detection

build.gradle.kts

@@ -8,7 +8,7 @@ plugins {
 }
 
 group = "com.moulberry.axiom"
-version = "1.5.12"
+version = "3.3.0"
 description = "Serverside component for Axiom on Paper"
 
 java {

src/main/java/com/moulberry/axiom/AxiomConstants.java

@@ -12,7 +12,7 @@ public class AxiomConstants {
         }
     }
 
-    public static final int API_VERSION = 7;
+    public static final int API_VERSION = 8;
     public static final NamespacedKey ACTIVE_HOTBAR_INDEX = new NamespacedKey("axiom", "active_hotbar_index");
     public static final NamespacedKey HOTBAR_DATA = new NamespacedKey("axiom", "hotbar_data");
 

src/main/java/com/moulberry/axiom/AxiomPaper.java

@@ -65,6 +65,7 @@ public class AxiomPaper extends JavaPlugin implements Listener {
     private boolean logLargeBlockBufferChanges = false;
 
     public Path blueprintFolder = null;
+    public boolean allowAnnotations = false;
 
     @Override
     public void onEnable() {
@@ -87,6 +88,11 @@ public class AxiomPaper extends JavaPlugin implements Listener {
         List<String> disallowedBlocks = this.configuration.getStringList("disallowed-blocks");
         this.allowedBlockRegistry = DisallowedBlocks.createAllowedBlockRegistry(disallowedBlocks);
 
+        this.allowAnnotations = this.configuration.getBoolean("allow-annotations");
+
+        int allowedCapabilities = calculateAllowedCapabilities();
+        int infiniteReachLimit = this.configuration.getInt("infinite-reach-limit");
+
         Bukkit.getPluginManager().registerEvents(this, this);
         // Bukkit.getPluginManager().registerEvents(new WorldPropertiesExample(), this);
         CompressedBlockEntity.initialize(this);
@@ -103,6 +109,7 @@ public class AxiomPaper extends JavaPlugin implements Listener {
         msg.registerOutgoingPluginChannel(this, "axiom:restrictions");
         msg.registerOutgoingPluginChannel(this, "axiom:marker_data");
         msg.registerOutgoingPluginChannel(this, "axiom:marker_nbt_response");
+        msg.registerOutgoingPluginChannel(this, "axiom:annotation_update");
 
         if (configuration.getBoolean("packet-handlers.hello")) {
             msg.registerIncomingPluginChannel(this, "axiom:hello", new HelloPacketListener(this));
@@ -158,6 +165,7 @@ public class AxiomPaper extends JavaPlugin implements Listener {
         if (configuration.getBoolean("packet-handlers.set-buffer")) {
             SetBlockBufferPacketListener setBlockBufferPacketListener = new SetBlockBufferPacketListener(this);
             UploadBlueprintPacketListener uploadBlueprintPacketListener = new UploadBlueprintPacketListener(this);
+            UpdateAnnotationPacketListener updateAnnotationPacketListener = new UpdateAnnotationPacketListener(this);
             RequestChunkDataPacketListener requestChunkDataPacketListener = allowLargeChunkDataRequest ?
                 new RequestChunkDataPacketListener(this) : null;
 
@@ -179,7 +187,7 @@ public class AxiomPaper extends JavaPlugin implements Listener {
                     Connection connection = (Connection) channel.pipeline().get("packet_handler");
                     channel.pipeline().addBefore("decoder", "axiom-big-payload-handler",
                         new AxiomBigPayloadHandler(payloadId, connection, setBlockBufferPacketListener,
-                            uploadBlueprintPacketListener, requestChunkDataPacketListener));
+                            uploadBlueprintPacketListener, updateAnnotationPacketListener, requestChunkDataPacketListener));
                 }
             });
         }
@@ -252,12 +260,19 @@ public class AxiomPaper extends JavaPlugin implements Listener {
                         }
 
                         boolean allowImportingBlocks = player.hasPermission("axiom.can_import_blocks");
+                        boolean canCreateAnnotations = this.allowAnnotations && player.hasPermission("axiom.annotation.create");
 
                         if (restrictions.maxSectionsPerSecond != rateLimit ||
                                 restrictions.canImportBlocks != allowImportingBlocks ||
+                                restrictions.canCreateAnnotations != canCreateAnnotations ||
+                                restrictions.allowedCapabilities != allowedCapabilities ||
+                                restrictions.infiniteReachLimit != infiniteReachLimit ||
                                 !Objects.equals(restrictions.bounds, bounds)) {
                             restrictions.maxSectionsPerSecond = rateLimit;
                             restrictions.canImportBlocks = allowImportingBlocks;
+                            restrictions.canCreateAnnotations = canCreateAnnotations;
+                            restrictions.allowedCapabilities = allowedCapabilities;
+                            restrictions.infiniteReachLimit = infiniteReachLimit;
                             restrictions.bounds = bounds;
                             send = true;
                         }
@@ -302,6 +317,25 @@ public class AxiomPaper extends JavaPlugin implements Listener {
         }
     }
 
+    private int calculateAllowedCapabilities() {
+        Set<String> allowed = new HashSet<>(this.configuration.getStringList("allow-capabilities"));
+        if (allowed.contains("all")) {
+            return -1;
+        }
+
+        int allowedCapabilities = 0;
+        if (allowed.contains("bulldozer")) allowedCapabilities |= Restrictions.ALLOW_BULLDOZER;
+        if (allowed.contains("replace_mode")) allowedCapabilities |= Restrictions.ALLOW_REPLACE_MODE;
+        if (allowed.contains("force_place")) allowedCapabilities |= Restrictions.ALLOW_FORCE_PLACE;
+        if (allowed.contains("no_updates")) allowedCapabilities |= Restrictions.ALLOW_NO_UPDATES;
+        if (allowed.contains("tinker")) allowedCapabilities |= Restrictions.ALLOW_TINKER;
+        if (allowed.contains("infinite_reach")) allowedCapabilities |= Restrictions.ALLOW_INFINITE_REACH;
+        if (allowed.contains("fast_place")) allowedCapabilities |= Restrictions.ALLOW_FAST_PLACE;
+        if (allowed.contains("angel_placement")) allowedCapabilities |= Restrictions.ALLOW_ANGEL_PLACEMENT;
+        if (allowed.contains("no_clip")) allowedCapabilities |= Restrictions.ALLOW_NO_CLIP;
+        return allowedCapabilities;
+    }
+
     public boolean logLargeBlockBufferChanges() {
         return this.logLargeBlockBufferChanges;
     }

src/main/java/com/moulberry/axiom/Restrictions.java

@@ -10,20 +10,36 @@ import java.util.Set;
 
 public class Restrictions {
 
+    public static final int ALLOW_BULLDOZER = 1;
+    public static final int ALLOW_REPLACE_MODE = 2;
+    public static final int ALLOW_FORCE_PLACE = 4;
+    public static final int ALLOW_NO_UPDATES = 8;
+    public static final int ALLOW_TINKER = 16;
+    public static final int ALLOW_INFINITE_REACH = 32;
+    public static final int ALLOW_FAST_PLACE = 64;
+    public static final int ALLOW_ANGEL_PLACEMENT = 128;
+    public static final int ALLOW_NO_CLIP = 256;
+    public static final int ALLOW_ALL = -1;
+
     public boolean canImportBlocks = true;
     public boolean canUseEditor = true;
     public boolean canEditDisplayEntities = true;
+    public boolean canCreateAnnotations = false;
+    public int allowedCapabilities = ALLOW_ALL;
+    public int infiniteReachLimit = -1;
+
     public int maxSectionsPerSecond = 0;
     public Set<PlotSquaredIntegration.PlotBox> bounds = Set.of();
-
     public PlotSquaredIntegration.PlotBounds lastPlotBounds = null;
 
     public void send(AxiomPaper plugin, Player player) {
-        if (player.getListeningPluginChannels().contains("axiom:restrictions")) {
         FriendlyByteBuf buf = new FriendlyByteBuf(Unpooled.buffer());
         buf.writeBoolean(this.canImportBlocks);
         buf.writeBoolean(this.canUseEditor);
         buf.writeBoolean(this.canEditDisplayEntities);
+        buf.writeBoolean(this.canCreateAnnotations);
+        buf.writeInt(this.allowedCapabilities);
+        buf.writeInt(this.infiniteReachLimit);
 
         buf.writeVarInt(this.maxSectionsPerSecond);
 
@@ -65,7 +81,6 @@ public class Restrictions {
         buf.getBytes(0, bytes);
         player.sendPluginMessage(plugin, "axiom:restrictions", bytes);
     }
-    }
 
     @Override
     public String toString() {

src/main/java/com/moulberry/axiom/WorldExtension.java

@@ -1,5 +1,6 @@
 package com.moulberry.axiom;
 
+import com.moulberry.axiom.annotations.ServerAnnotations;
 import com.moulberry.axiom.marker.MarkerData;
 import io.netty.buffer.Unpooled;
 import it.unimi.dsi.fastutil.longs.*;
@@ -35,6 +36,10 @@ public class WorldExtension {
     public static void onPlayerJoin(World world, Player player) {
         ServerLevel level = ((CraftWorld)world).getHandle();
         get(level).onPlayerJoin(player);
+
+        if (AxiomPaper.PLUGIN.canUseAxiom(player, "axiom.annotations.view")) {
+            ServerAnnotations.sendAll(world, ((CraftPlayer)player).getHandle());
+        }
     }
 
     public static void tick(MinecraftServer server, boolean sendMarkers, int maxChunkRelightsPerTick, int maxChunkSendsPerTick) {

src/main/java/com/moulberry/axiom/annotations/AnnotationUpdateAction.java

@@ -0,0 +1,93 @@
+package com.moulberry.axiom.annotations;
+
+import com.moulberry.axiom.annotations.data.AnnotationData;
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+import java.util.UUID;
+
+public interface AnnotationUpdateAction {
+
+    void write(FriendlyByteBuf friendlyByteBuf);
+
+    static AnnotationUpdateAction read(FriendlyByteBuf friendlyByteBuf) {
+        byte type = friendlyByteBuf.readByte();
+        if (type == 0) {
+            UUID uuid = friendlyByteBuf.readUUID();
+            AnnotationData annotationData = AnnotationData.read(friendlyByteBuf);
+            if (annotationData == null) {
+                return null;
+            }
+            return new CreateAnnotation(uuid, annotationData);
+        } else if (type == 1) {
+            return new DeleteAnnotation(friendlyByteBuf.readUUID());
+        } else if (type == 2) {
+            return new MoveAnnotation(friendlyByteBuf.readUUID(), new Vector3f(
+                friendlyByteBuf.readFloat(),
+                friendlyByteBuf.readFloat(),
+                friendlyByteBuf.readFloat()
+            ));
+        } else if (type == 3) {
+            return new ClearAllAnnotations();
+        } else if (type == 4) {
+            return new RotateAnnotation(friendlyByteBuf.readUUID(), new Quaternionf(
+                friendlyByteBuf.readFloat(),
+                friendlyByteBuf.readFloat(),
+                friendlyByteBuf.readFloat(),
+                friendlyByteBuf.readFloat()
+            ));
+        } else {
+            return null;
+        }
+    }
+
+    record CreateAnnotation(UUID uuid, AnnotationData annotationData) implements AnnotationUpdateAction {
+        @Override
+        public void write(FriendlyByteBuf friendlyByteBuf) {
+            friendlyByteBuf.writeByte(0);
+            friendlyByteBuf.writeUUID(this.uuid);
+            this.annotationData.write(friendlyByteBuf);
+        }
+    }
+
+    record DeleteAnnotation(UUID uuid) implements AnnotationUpdateAction {
+        @Override
+        public void write(FriendlyByteBuf friendlyByteBuf) {
+            friendlyByteBuf.writeByte(1);
+            friendlyByteBuf.writeUUID(this.uuid);
+        }
+    }
+
+    record MoveAnnotation(UUID uuid, Vector3f to) implements AnnotationUpdateAction {
+        @Override
+        public void write(FriendlyByteBuf friendlyByteBuf) {
+            friendlyByteBuf.writeByte(2);
+            friendlyByteBuf.writeUUID(this.uuid);
+            friendlyByteBuf.writeFloat(this.to.x);
+            friendlyByteBuf.writeFloat(this.to.y);
+            friendlyByteBuf.writeFloat(this.to.z);
+        }
+    }
+
+    record ClearAllAnnotations() implements AnnotationUpdateAction {
+        @Override
+        public void write(FriendlyByteBuf friendlyByteBuf) {
+            friendlyByteBuf.writeByte(3);
+        }
+    }
+
+
+    record RotateAnnotation(UUID uuid, Quaternionf to) implements AnnotationUpdateAction {
+        @Override
+        public void write(FriendlyByteBuf friendlyByteBuf) {
+            friendlyByteBuf.writeByte(4);
+            friendlyByteBuf.writeUUID(this.uuid);
+            friendlyByteBuf.writeFloat(this.to.x);
+            friendlyByteBuf.writeFloat(this.to.y);
+            friendlyByteBuf.writeFloat(this.to.z);
+            friendlyByteBuf.writeFloat(this.to.w);
+        }
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/ServerAnnotations.java

@@ -0,0 +1,136 @@
+package com.moulberry.axiom.annotations;
+
+import com.moulberry.axiom.AxiomPaper;
+import com.moulberry.axiom.VersionHelper;
+import com.moulberry.axiom.annotations.data.AnnotationData;
+import io.netty.buffer.Unpooled;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.util.datafix.DataFixTypes;
+import net.minecraft.world.level.saveddata.SavedData;
+import org.bukkit.NamespacedKey;
+import org.bukkit.World;
+import org.bukkit.craftbukkit.v1_20_R3.CraftWorld;
+import org.bukkit.persistence.PersistentDataAdapterContext;
+import org.bukkit.persistence.PersistentDataContainer;
+import org.bukkit.persistence.PersistentDataType;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.WeakHashMap;
+
+public class ServerAnnotations {
+
+    private static final WeakHashMap<World, ServerAnnotations> serverAnnotationCache = new WeakHashMap<>();
+    private static final NamespacedKey ANNOTATION_DATA_KEY = new NamespacedKey(AxiomPaper.PLUGIN, "annotation_data");
+
+    final LinkedHashMap<UUID, AnnotationData> annotations = new LinkedHashMap<>();
+
+    private static void sendAnnotationUpdates(List<AnnotationUpdateAction> actions, List<ServerPlayer> players) {
+        FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.buffer());
+        friendlyByteBuf.writeCollection(actions, (buffer, action) -> action.write(buffer));
+
+        byte[] bytes = new byte[friendlyByteBuf.writerIndex()];
+        friendlyByteBuf.getBytes(0, bytes);
+        for (ServerPlayer serverPlayer : players) {
+            VersionHelper.sendCustomPayload(serverPlayer, VersionHelper.createResourceLocation("axiom:annotation_update"), bytes);
+        }
+    }
+
+    public static void sendAll(World world, ServerPlayer player) {
+        if (!AxiomPaper.PLUGIN.allowAnnotations) {
+            return;
+        }
+
+        List<AnnotationUpdateAction> actions = new ArrayList<>();
+
+        actions.add(new AnnotationUpdateAction.ClearAllAnnotations());
+
+        ServerAnnotations serverAnnotations = serverAnnotationCache.get(world);
+        if (serverAnnotations == null) {
+            serverAnnotations = world.getPersistentDataContainer().get(ANNOTATION_DATA_KEY, ServerAnnotationsAdapater.INSTANCE);
+            serverAnnotationCache.put(world, serverAnnotations);
+        }
+
+        if (serverAnnotations != null) {
+            for (Map.Entry<UUID, AnnotationData> entry : serverAnnotations.annotations.entrySet()) {
+                actions.add(new AnnotationUpdateAction.CreateAnnotation(entry.getKey(), entry.getValue()));
+            }
+        }
+
+        sendAnnotationUpdates(actions, List.of(player));
+    }
+
+    public static void handleUpdates(World world, List<AnnotationUpdateAction> actions) {
+        if (!AxiomPaper.PLUGIN.allowAnnotations) {
+            return;
+        }
+
+        ServerAnnotations serverAnnotations = serverAnnotationCache.get(world);
+        if (serverAnnotations == null) {
+            serverAnnotations = world.getPersistentDataContainer().get(ANNOTATION_DATA_KEY, ServerAnnotationsAdapater.INSTANCE);
+            serverAnnotationCache.put(world, serverAnnotations);
+        }
+        if (serverAnnotations == null) {
+            serverAnnotations = new ServerAnnotations();
+            serverAnnotationCache.put(world, serverAnnotations);
+        }
+
+        boolean dirty = false;
+
+        for (AnnotationUpdateAction action : actions) {
+            if (action instanceof AnnotationUpdateAction.CreateAnnotation create) {
+                serverAnnotations.annotations.put(create.uuid(), create.annotationData());
+                dirty = true;
+            } else if (action instanceof AnnotationUpdateAction.DeleteAnnotation delete) {
+                AnnotationData removed = serverAnnotations.annotations.remove(delete.uuid());
+                if (removed != null) {
+                    dirty = true;
+                }
+            } else if (action instanceof AnnotationUpdateAction.MoveAnnotation move) {
+                AnnotationData annotation = serverAnnotations.annotations.get(move.uuid());
+                if (annotation != null) {
+                    annotation.setPosition(move.to());
+                    dirty = true;
+                }
+            } else if (action instanceof AnnotationUpdateAction.ClearAllAnnotations) {
+                if (!serverAnnotations.annotations.isEmpty()) {
+                    serverAnnotations.annotations.clear();
+                    dirty = true;
+                }
+            } else if (action instanceof AnnotationUpdateAction.RotateAnnotation rotate) {
+                AnnotationData annotation = serverAnnotations.annotations.get(rotate.uuid());
+                if (annotation != null) {
+                    annotation.setRotation(rotate.to());
+                    dirty = true;
+                }
+            } else {
+                throw new UnsupportedOperationException("Unknown action: " + action.getClass());
+            }
+        }
+
+        if (dirty) {
+            world.getPersistentDataContainer().set(ANNOTATION_DATA_KEY, ServerAnnotationsAdapater.INSTANCE, serverAnnotations);
+        }
+
+        // Forward actions back to clients
+        List<ServerPlayer> playersWithAxiom = new ArrayList<>();
+
+        for (ServerPlayer player : ((CraftWorld)world).getHandle().players()) {
+            if (AxiomPaper.PLUGIN.canUseAxiom(player.getBukkitEntity(), "axiom.annotations.view")) {
+                playersWithAxiom.add(player);
+            }
+        }
+
+        if (!playersWithAxiom.isEmpty()) {
+            sendAnnotationUpdates(actions, playersWithAxiom);
+        }
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/ServerAnnotationsAdapater.java

@@ -0,0 +1,73 @@
+package com.moulberry.axiom.annotations;
+
+import com.moulberry.axiom.AxiomPaper;
+import com.moulberry.axiom.annotations.data.AnnotationData;
+import io.netty.buffer.Unpooled;
+import net.minecraft.network.FriendlyByteBuf;
+import org.bukkit.NamespacedKey;
+import org.bukkit.persistence.PersistentDataAdapterContext;
+import org.bukkit.persistence.PersistentDataContainer;
+import org.bukkit.persistence.PersistentDataType;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Map;
+import java.util.UUID;
+
+public class ServerAnnotationsAdapater implements PersistentDataType<PersistentDataContainer, ServerAnnotations>  {
+    public static final ServerAnnotationsAdapater INSTANCE = new ServerAnnotationsAdapater();
+
+    @Override
+    public @NotNull Class<PersistentDataContainer> getPrimitiveType() {
+        return PersistentDataContainer.class;
+    }
+
+    @Override
+    public @NotNull Class<ServerAnnotations> getComplexType() {
+        return ServerAnnotations.class;
+    }
+
+    @Override
+    public @NotNull PersistentDataContainer toPrimitive(@NotNull ServerAnnotations serverAnnotations, @NotNull PersistentDataAdapterContext context) {
+        PersistentDataContainer container = context.newPersistentDataContainer();
+
+        FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.buffer());
+
+        for (Map.Entry<UUID, AnnotationData> entry : serverAnnotations.annotations.entrySet()) {
+            try {
+                friendlyByteBuf.writerIndex(0);
+                entry.getValue().write(friendlyByteBuf);
+
+                byte[] bytes = new byte[friendlyByteBuf.writerIndex()];
+                friendlyByteBuf.getBytes(0, bytes);
+
+                container.set(new NamespacedKey(AxiomPaper.PLUGIN, entry.getKey().toString()),
+                    PersistentDataType.BYTE_ARRAY, bytes);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+
+        return container;
+    }
+
+    @Override
+    public @NotNull ServerAnnotations fromPrimitive(@NotNull PersistentDataContainer container, @NotNull PersistentDataAdapterContext context) {
+        ServerAnnotations serverAnnotations = new ServerAnnotations();
+
+        for (NamespacedKey key : container.getKeys()) {
+            try {
+                String uuidString = key.value();
+                UUID uuid = UUID.fromString(uuidString);
+
+                byte[] bytes = container.get(key, PersistentDataType.BYTE_ARRAY);
+                AnnotationData annotation = AnnotationData.read(new FriendlyByteBuf(Unpooled.wrappedBuffer(bytes)));
+
+                serverAnnotations.annotations.put(uuid, annotation);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+
+        return serverAnnotations;
+    }
+}

src/main/java/com/moulberry/axiom/annotations/data/AnnotationData.java

@@ -0,0 +1,32 @@
+package com.moulberry.axiom.annotations.data;
+
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+public interface AnnotationData {
+
+    void setPosition(Vector3f position);
+    void setRotation(Quaternionf rotation);
+    void write(FriendlyByteBuf friendlyByteBuf);
+
+    static AnnotationData read(FriendlyByteBuf friendlyByteBuf) {
+        byte type = friendlyByteBuf.readByte();
+        if (type == 0) {
+            return LineAnnotationData.read(friendlyByteBuf);
+        } else if (type == 1) {
+            return TextAnnotationData.read(friendlyByteBuf);
+        } else if (type == 2) {
+            return ImageAnnotationData.read(friendlyByteBuf);
+        } else if (type == 3) {
+            return FreehandOutlineAnnotationData.read(friendlyByteBuf);
+        } else if (type == 4) {
+            return LinesOutlineAnnotationData.read(friendlyByteBuf);
+        } else if (type == 5) {
+            return BoxOutlineAnnotationData.read(friendlyByteBuf);
+        } else {
+            return null;
+        }
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/data/BoxOutlineAnnotationData.java

@@ -0,0 +1,44 @@
+package com.moulberry.axiom.annotations.data;
+
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+public record BoxOutlineAnnotationData(int fromX, int fromY, int fromZ, int toX, int toY, int toZ, int colour) implements AnnotationData {
+
+    public BoxOutlineAnnotationData {
+        colour = 0xFF000000 | colour;
+    }
+
+    @Override
+    public void setPosition(Vector3f position) {
+    }
+
+    @Override
+    public void setRotation(Quaternionf rotation) {
+    }
+
+    @Override
+    public void write(FriendlyByteBuf friendlyByteBuf) {
+        friendlyByteBuf.writeByte(5);
+        friendlyByteBuf.writeVarInt(this.fromX);
+        friendlyByteBuf.writeVarInt(this.fromY);
+        friendlyByteBuf.writeVarInt(this.fromZ);
+        friendlyByteBuf.writeVarInt(this.toX);
+        friendlyByteBuf.writeVarInt(this.toY);
+        friendlyByteBuf.writeVarInt(this.toZ);
+        friendlyByteBuf.writeInt(this.colour);
+    }
+
+    public static BoxOutlineAnnotationData read(FriendlyByteBuf friendlyByteBuf) {
+        int fromX = friendlyByteBuf.readVarInt();
+        int fromY = friendlyByteBuf.readVarInt();
+        int fromZ = friendlyByteBuf.readVarInt();
+        int toX = friendlyByteBuf.readVarInt();
+        int toY = friendlyByteBuf.readVarInt();
+        int toZ = friendlyByteBuf.readVarInt();
+        int colour = friendlyByteBuf.readInt();
+        return new BoxOutlineAnnotationData(fromX, fromY, fromZ, toX, toY, toZ, colour);
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/data/FreehandOutlineAnnotationData.java

@@ -0,0 +1,43 @@
+package com.moulberry.axiom.annotations.data;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+public record FreehandOutlineAnnotationData(BlockPos start, byte[] offsets, int offsetCount, int colour) implements AnnotationData {
+
+    public FreehandOutlineAnnotationData {
+        colour = 0xFF000000 | colour;
+    }
+
+    @Override
+    public void setPosition(Vector3f position) {
+    }
+
+    @Override
+    public void setRotation(Quaternionf rotation) {
+    }
+
+    @Override
+    public void write(FriendlyByteBuf friendlyByteBuf) {
+        friendlyByteBuf.writeByte(3);
+        friendlyByteBuf.writeVarInt(this.start.getX());
+        friendlyByteBuf.writeVarInt(this.start.getY());
+        friendlyByteBuf.writeVarInt(this.start.getZ());
+        friendlyByteBuf.writeVarInt(this.offsetCount);
+        friendlyByteBuf.writeInt(this.colour);
+        friendlyByteBuf.writeByteArray(this.offsets);
+    }
+
+    public static FreehandOutlineAnnotationData read(FriendlyByteBuf friendlyByteBuf) {
+        int x = friendlyByteBuf.readVarInt();
+        int y = friendlyByteBuf.readVarInt();
+        int z = friendlyByteBuf.readVarInt();
+        int offsetCount = friendlyByteBuf.readVarInt();
+        int colour = friendlyByteBuf.readInt();
+        byte[] offsets = friendlyByteBuf.readByteArray();
+        return new FreehandOutlineAnnotationData(new BlockPos(x, y, z), offsets, offsetCount, colour);
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/data/ImageAnnotationData.java

@@ -0,0 +1,53 @@
+package com.moulberry.axiom.annotations.data;
+
+import net.minecraft.core.Direction;
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+public record ImageAnnotationData(String imageUrl, Vector3f position, Quaternionf rotation, Direction direction, float fallbackYaw, float width, int billboardMode) implements AnnotationData {
+
+    @Override
+    public void setPosition(Vector3f position) {
+        this.position.set(position);
+    }
+
+    @Override
+    public void setRotation(Quaternionf rotation) {
+        this.rotation.set(rotation);
+    }
+
+    @Override
+    public void write(FriendlyByteBuf friendlyByteBuf) {
+        friendlyByteBuf.writeByte(2);
+        friendlyByteBuf.writeUtf(this.imageUrl);
+        friendlyByteBuf.writeFloat(this.position.x);
+        friendlyByteBuf.writeFloat(this.position.y);
+        friendlyByteBuf.writeFloat(this.position.z);
+        friendlyByteBuf.writeFloat(this.rotation.x);
+        friendlyByteBuf.writeFloat(this.rotation.y);
+        friendlyByteBuf.writeFloat(this.rotation.z);
+        friendlyByteBuf.writeFloat(this.rotation.w);
+        friendlyByteBuf.writeByte(this.direction.get3DDataValue());
+        friendlyByteBuf.writeFloat(this.fallbackYaw);
+        friendlyByteBuf.writeFloat(this.width);
+        friendlyByteBuf.writeByte(this.billboardMode);
+    }
+
+    public static ImageAnnotationData read(FriendlyByteBuf friendlyByteBuf) {
+        String imageUrl = friendlyByteBuf.readUtf();
+        float x = friendlyByteBuf.readFloat();
+        float y = friendlyByteBuf.readFloat();
+        float z = friendlyByteBuf.readFloat();
+        float rotX = friendlyByteBuf.readFloat();
+        float rotY = friendlyByteBuf.readFloat();
+        float rotZ = friendlyByteBuf.readFloat();
+        float rotW = friendlyByteBuf.readFloat();
+        Direction direction = Direction.from3DDataValue(friendlyByteBuf.readByte());
+        float fallbackYaw = friendlyByteBuf.readFloat();
+        float width = friendlyByteBuf.readFloat();
+        int billboardMode = friendlyByteBuf.readByte();
+        return new ImageAnnotationData(imageUrl, new Vector3f(x, y, z), new Quaternionf(rotX, rotY, rotZ, rotW), direction, fallbackYaw, width, billboardMode);
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/data/LineAnnotationData.java

@@ -0,0 +1,43 @@
+package com.moulberry.axiom.annotations.data;
+
+import net.minecraft.core.Vec3i;
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+public record LineAnnotationData(Vec3i startQuantized, byte[] offsets, float lineWidth, int colour) implements AnnotationData {
+
+    public LineAnnotationData {
+        colour = 0xFF000000 | colour;
+    }
+
+    @Override
+    public void setPosition(Vector3f position) {
+    }
+
+    @Override
+    public void setRotation(Quaternionf rotation) {
+    }
+
+    @Override
+    public void write(FriendlyByteBuf friendlyByteBuf) {
+        friendlyByteBuf.writeByte(0);
+        friendlyByteBuf.writeVarInt(this.startQuantized.getX());
+        friendlyByteBuf.writeVarInt(this.startQuantized.getY());
+        friendlyByteBuf.writeVarInt(this.startQuantized.getZ());
+        friendlyByteBuf.writeFloat(this.lineWidth);
+        friendlyByteBuf.writeInt(this.colour);
+        friendlyByteBuf.writeByteArray(this.offsets);
+    }
+
+    public static LineAnnotationData read(FriendlyByteBuf friendlyByteBuf) {
+        int x = friendlyByteBuf.readVarInt();
+        int y = friendlyByteBuf.readVarInt();
+        int z = friendlyByteBuf.readVarInt();
+        float lineWidth = friendlyByteBuf.readFloat();
+        int colour = friendlyByteBuf.readInt();
+        byte[] offsets = friendlyByteBuf.readByteArray();
+        return new LineAnnotationData(new Vec3i(x, y, z), offsets, lineWidth, colour);
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/data/LinesOutlineAnnotationData.java

@@ -0,0 +1,41 @@
+package com.moulberry.axiom.annotations.data;
+
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+public record LinesOutlineAnnotationData(long[] positions, int colour) implements AnnotationData {
+
+    public LinesOutlineAnnotationData {
+        colour = 0xFF000000 | colour;
+    }
+
+    @Override
+    public void setPosition(Vector3f position) {
+    }
+
+    @Override
+    public void setRotation(Quaternionf rotation) {
+    }
+
+    @Override
+    public void write(FriendlyByteBuf friendlyByteBuf) {
+        friendlyByteBuf.writeByte(4);
+        friendlyByteBuf.writeVarInt(this.positions.length);
+        for (long position : this.positions) {
+            friendlyByteBuf.writeLong(position);
+        }
+        friendlyByteBuf.writeInt(this.colour);
+    }
+
+    public static LinesOutlineAnnotationData read(FriendlyByteBuf friendlyByteBuf) {
+        int positionCount = friendlyByteBuf.readVarInt();
+        long[] positions = new long[positionCount];
+        for (int i = 0; i < positionCount; i++) {
+            positions[i] = friendlyByteBuf.readLong();
+        }
+        int colour = friendlyByteBuf.readInt();
+        return new LinesOutlineAnnotationData(positions, colour);
+    }
+
+}

src/main/java/com/moulberry/axiom/annotations/data/TextAnnotationData.java

@@ -0,0 +1,58 @@
+package com.moulberry.axiom.annotations.data;
+
+import net.minecraft.core.Direction;
+import net.minecraft.network.FriendlyByteBuf;
+import org.joml.Quaternionf;
+import org.joml.Vector3f;
+
+public record TextAnnotationData(String text, Vector3f position, Quaternionf rotation, Direction direction, float fallbackYaw, float scale,
+                                 int billboardMode, int colour, boolean shadow) implements AnnotationData {
+
+    @Override
+    public void setPosition(Vector3f position) {
+        this.position.set(position);
+    }
+
+    @Override
+    public void setRotation(Quaternionf rotation) {
+        this.rotation.set(rotation);
+    }
+
+    @Override
+    public void write(FriendlyByteBuf friendlyByteBuf) {
+        friendlyByteBuf.writeByte(1);
+        friendlyByteBuf.writeUtf(this.text);
+        friendlyByteBuf.writeFloat(this.position.x);
+        friendlyByteBuf.writeFloat(this.position.y);
+        friendlyByteBuf.writeFloat(this.position.z);
+        friendlyByteBuf.writeFloat(this.rotation.x);
+        friendlyByteBuf.writeFloat(this.rotation.y);
+        friendlyByteBuf.writeFloat(this.rotation.z);
+        friendlyByteBuf.writeFloat(this.rotation.w);
+        friendlyByteBuf.writeByte(this.direction.get3DDataValue());
+        friendlyByteBuf.writeFloat(this.fallbackYaw);
+        friendlyByteBuf.writeFloat(this.scale);
+        friendlyByteBuf.writeByte(this.billboardMode);
+        friendlyByteBuf.writeInt(this.colour);
+        friendlyByteBuf.writeBoolean(this.shadow);
+    }
+
+    public static TextAnnotationData read(FriendlyByteBuf friendlyByteBuf) {
+        String text = friendlyByteBuf.readUtf();
+        float x = friendlyByteBuf.readFloat();
+        float y = friendlyByteBuf.readFloat();
+        float z = friendlyByteBuf.readFloat();
+        float rotX = friendlyByteBuf.readFloat();
+        float rotY = friendlyByteBuf.readFloat();
+        float rotZ = friendlyByteBuf.readFloat();
+        float rotW = friendlyByteBuf.readFloat();
+        Direction direction = Direction.from3DDataValue(friendlyByteBuf.readByte());
+        float fallbackYaw = friendlyByteBuf.readFloat();
+        float scale = friendlyByteBuf.readFloat();
+        int billboardMode = friendlyByteBuf.readByte();
+        int colour = friendlyByteBuf.readInt();
+        boolean shadow = friendlyByteBuf.readBoolean();
+        return new TextAnnotationData(text, new Vector3f(x, y, z), new Quaternionf(rotX, rotY, rotZ, rotW), direction, fallbackYaw, scale, billboardMode, colour, shadow);
+    }
+
+}

src/main/java/com/moulberry/axiom/packet/AxiomBigPayloadHandler.java

@@ -20,19 +20,23 @@ public class AxiomBigPayloadHandler extends MessageToMessageDecoder<ByteBuf> {
 
     private static final ResourceLocation SET_BUFFER = VersionHelper.createResourceLocation("axiom", "set_buffer");
     private static final ResourceLocation UPLOAD_BLUEPRINT = VersionHelper.createResourceLocation("axiom", "upload_blueprint");
+    private static final ResourceLocation UPDATE_ANNOTATIONS = VersionHelper.createResourceLocation("axiom", "annotation_update");
     private static final ResourceLocation REQUEST_CHUNK_DATA = VersionHelper.createResourceLocation("axiom", "request_chunk_data");
     private final int payloadId;
     private final Connection connection;
     private final SetBlockBufferPacketListener setBlockBuffer;
     private final UploadBlueprintPacketListener uploadBlueprint;
+    private final UpdateAnnotationPacketListener updateAnnotation;
     private final RequestChunkDataPacketListener requestChunkDataPacketListener;
 
     public AxiomBigPayloadHandler(int payloadId, Connection connection, SetBlockBufferPacketListener setBlockBuffer,
-            UploadBlueprintPacketListener uploadBlueprint, RequestChunkDataPacketListener requestChunkDataPacketListener) {
+            UploadBlueprintPacketListener uploadBlueprint, UpdateAnnotationPacketListener updateAnnotation,
+            RequestChunkDataPacketListener requestChunkDataPacketListener) {
         this.payloadId = payloadId;
         this.connection = connection;
         this.setBlockBuffer = setBlockBuffer;
         this.uploadBlueprint = uploadBlueprint;
+        this.updateAnnotation = updateAnnotation;
         this.requestChunkDataPacketListener = requestChunkDataPacketListener;
     }
 
@@ -80,6 +84,14 @@ public class AxiomBigPayloadHandler extends MessageToMessageDecoder<ByteBuf> {
                             " bytes extra whilst reading packet");
                     }
                     return;
+                } else if (identifier.equals(UPDATE_ANNOTATIONS)) {
+                    updateAnnotation.onReceive(player, buf);
+                    success = true;
+                    if (in.readableBytes() > 0) {
+                        throw new IOException("Axiom packet " + identifier + " was larger than I expected, found " + in.readableBytes() +
+                            " bytes extra whilst reading packet");
+                    }
+                    return;
                 } else if (requestChunkDataPacketListener != null && identifier.equals(REQUEST_CHUNK_DATA)) {
                     byte[] bytes = new byte[buf.writerIndex() - buf.readerIndex()];
                     buf.getBytes(buf.readerIndex(), bytes);
@@ -122,7 +134,7 @@ public class AxiomBigPayloadHandler extends MessageToMessageDecoder<ByteBuf> {
         if (evt == ConnectionEvent.COMPRESSION_THRESHOLD_SET || evt == ConnectionEvent.COMPRESSION_DISABLED) {
             ctx.channel().pipeline().remove("axiom-big-payload-handler");
             ctx.channel().pipeline().addBefore("decoder", "axiom-big-payload-handler",
-                                   new AxiomBigPayloadHandler(payloadId, connection, setBlockBuffer, uploadBlueprint, requestChunkDataPacketListener));
+                                   new AxiomBigPayloadHandler(payloadId, connection, setBlockBuffer, uploadBlueprint, updateAnnotation, requestChunkDataPacketListener));
         }
         super.userEventTriggered(ctx, evt);
     }

src/main/java/com/moulberry/axiom/packet/HelloPacketListener.java

@@ -2,6 +2,7 @@ package com.moulberry.axiom.packet;
 
 import com.google.common.util.concurrent.RateLimiter;
 import com.moulberry.axiom.*;
+import com.moulberry.axiom.annotations.ServerAnnotations;
 import com.moulberry.axiom.blueprint.ServerBlueprintManager;
 import com.moulberry.axiom.event.AxiomHandshakeEvent;
 import com.moulberry.axiom.persistence.ItemStackDataType;
@@ -20,6 +21,7 @@ import net.minecraft.world.level.block.state.BlockState;
 import org.bukkit.Bukkit;
 import org.bukkit.NamespacedKey;
 import org.bukkit.World;
+import org.bukkit.craftbukkit.v1_20_R3.CraftWorld;
 import org.bukkit.craftbukkit.v1_20_R3.entity.CraftPlayer;
 import org.bukkit.craftbukkit.v1_20_R3.inventory.CraftItemStack;
 import org.bukkit.entity.Player;
@@ -49,13 +51,6 @@ public class HelloPacketListener implements PluginMessageListener {
         }
     }
 
-    private static int normalizeDataVersion(int dataVersion) {
-        if (dataVersion == 3955) { // 1.21.1
-            return 3953; // 1.21
-        }
-        return dataVersion;
-    }
-
     private void process(Player player, byte[] message) {
         if (!this.plugin.hasAxiomPermission(player)) {
             return;
@@ -63,11 +58,32 @@ public class HelloPacketListener implements PluginMessageListener {
 
         FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.wrappedBuffer(message));
         int apiVersion = friendlyByteBuf.readVarInt();
+
+        if (apiVersion != AxiomConstants.API_VERSION) {
+            String versions = " (C="+apiVersion+" S="+AxiomConstants.API_VERSION+")";
+            Component text;
+            if (apiVersion < AxiomConstants.API_VERSION) {
+                text = Component.text("Unable to use Axiom, you're on an outdated version! Please update to the latest version of Axiom to use it on this server." + versions);
+            } else {
+                text = Component.text("Unable to use Axiom, server hasn't updated Axiom yet." + versions);
+            }
+
+            String unsupportedAxiomVersion = plugin.configuration.getString("unsupported-axiom-version");
+            if (unsupportedAxiomVersion == null) unsupportedAxiomVersion = "kick";
+            if (unsupportedAxiomVersion.equals("warn")) {
+                player.sendMessage(text.color(NamedTextColor.RED));
+                return;
+            } else if (!unsupportedAxiomVersion.equals("ignore")) {
+                player.kick(text);
+                return;
+            }
+        }
+
         int dataVersion = friendlyByteBuf.readVarInt();
-        // note - skipping NBT here. friendlyByteBuf.readNBT();
+        int protocolVersion = friendlyByteBuf.readVarInt();
 
         int serverDataVersion = SharedConstants.getCurrentVersion().getDataVersion().getVersion();
-        if (normalizeDataVersion(dataVersion) != normalizeDataVersion(serverDataVersion)) {
+        if (protocolVersion != SharedConstants.getProtocolVersion()) {
             String incompatibleDataVersion = plugin.configuration.getString("incompatible-data-version");
             if (incompatibleDataVersion == null) incompatibleDataVersion = "warn";
 
@@ -83,35 +99,11 @@ public class HelloPacketListener implements PluginMessageListener {
                     return;
                 }
             } else {
-                int playerVersion = Via.getAPI().getPlayerVersion(player.getUniqueId());
-                if (playerVersion == SharedConstants.getProtocolVersion()) {
-                    // Likely using via on the proxy, try to get protocol version from data version
-                    if (dataVersion < 3337) {
-                        player.sendMessage(incompatibleWarning.color(NamedTextColor.RED));
-                        return;
-                    } else if (dataVersion == 3337) {
-                        playerVersion = 762; // 1.19.4
-                    } else if (dataVersion <= 3465) {
-                        playerVersion = 763; // 1.20.1
-                    } else if (dataVersion <= 3578) {
-                        playerVersion = 764; // 1.20.2
-                    } else if (dataVersion <= 3700) {
-                        playerVersion = 765; // 1.20.3 / 1.20.4
-                    } else if (dataVersion <= 3839) {
-                        playerVersion = 766; // 1.20.5 / 1.20.6
-                    } else if (dataVersion <= 3955) {
-                        playerVersion = 767; // 1.21.1
-                    } else {
-                        player.sendMessage(incompatibleWarning.color(NamedTextColor.RED));
-                        return;
-                    }
-                }
-
                 IdMapper<BlockState> mapper;
                 try {
-                    mapper = ViaVersionHelper.getBlockRegistryForVersion(this.plugin.allowedBlockRegistry, playerVersion);
+                    mapper = ViaVersionHelper.getBlockRegistryForVersion(this.plugin.allowedBlockRegistry, protocolVersion);
                 } catch (Exception e) {
-                    String clientDescription = "client: " + ProtocolVersion.getProtocol(playerVersion);
+                    String clientDescription = "client: " + ProtocolVersion.getProtocol(protocolVersion);
                     String serverDescription = "server: " + ProtocolVersion.getProtocol(SharedConstants.getProtocolVersion());
                     String description = clientDescription + " <-> " + serverDescription;
                     Component text = Component.text("Axiom+ViaVersion: " + e.getMessage() + " (" + description + ")");
@@ -125,7 +117,7 @@ public class HelloPacketListener implements PluginMessageListener {
                 }
 
                 this.plugin.playerBlockRegistry.put(player.getUniqueId(), mapper);
-                this.plugin.playerProtocolVersion.put(player.getUniqueId(), playerVersion);
+                this.plugin.playerProtocolVersion.put(player.getUniqueId(), protocolVersion);
 
                 Component text = Component.text("Axiom: Warning, client and server versions don't match. " +
                         "Axiom will try to use ViaVersion conversions, but this process may cause problems");
@@ -133,35 +125,6 @@ public class HelloPacketListener implements PluginMessageListener {
             }
         }
 
-        if (apiVersion != AxiomConstants.API_VERSION) {
-            Component text = Component.text("Unsupported Axiom API Version. Server supports " + AxiomConstants.API_VERSION +
-                ", while client is " + apiVersion);
-
-            String unsupportedAxiomVersion = plugin.configuration.getString("unsupported-axiom-version");
-            if (unsupportedAxiomVersion == null) unsupportedAxiomVersion = "kick";
-            if (unsupportedAxiomVersion.equals("warn")) {
-                player.sendMessage(text.color(NamedTextColor.RED));
-                return;
-            } else if (!unsupportedAxiomVersion.equals("ignore")) {
-                player.kick(text);
-                return;
-            }
-        }
-
-        if (!player.getListeningPluginChannels().contains("axiom:restrictions")) {
-            Component text = Component.text("This server requires the use of Axiom 2.3 or later. Contact the server administrator if you believe this is unintentional");
-
-            String unsupportedRestrictions = plugin.configuration.getString("client-doesnt-support-restrictions");
-            if (unsupportedRestrictions == null) unsupportedRestrictions = "warn";
-            if (unsupportedRestrictions.equals("warn")) {
-                player.sendMessage(text.color(NamedTextColor.RED));
-                return;
-            } else if (!unsupportedRestrictions.equals("ignore")) {
-                player.kick(text);
-                return;
-            }
-        }
-
         // Call handshake event
         int maxBufferSize = plugin.configuration.getInt("max-block-buffer-packet-size");
         AxiomHandshakeEvent handshakeEvent = new AxiomHandshakeEvent(player, maxBufferSize);

src/main/java/com/moulberry/axiom/packet/SetBlockPacketListener.java

@@ -33,10 +33,16 @@ import net.minecraft.world.phys.Vec3;
 import org.bukkit.Location;
 import org.bukkit.block.BlockFace;
 import org.bukkit.craftbukkit.v1_20_R3.CraftWorld;
+import org.bukkit.craftbukkit.v1_20_R3.block.CapturedBlockState;
 import org.bukkit.craftbukkit.v1_20_R3.block.CraftBlock;
+import org.bukkit.craftbukkit.v1_20_R3.block.CraftBlockStates;
 import org.bukkit.craftbukkit.v1_20_R3.entity.CraftPlayer;
+import org.bukkit.craftbukkit.v1_20_R3.event.CraftEventFactory;
+import org.bukkit.craftbukkit.v1_20_R3.util.CraftMagicNumbers;
 import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
 import org.bukkit.event.block.Action;
+import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.event.player.PlayerInteractEvent;
 import org.bukkit.plugin.messaging.PluginMessageListener;
 import org.jetbrains.annotations.NotNull;
@@ -44,6 +50,8 @@ import xyz.jpenilla.reflectionremapper.ReflectionRemapper;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
@@ -107,6 +115,8 @@ public class SetBlockPacketListener implements PluginMessageListener {
             player.connection.ackBlockChangesUpTo(sequenceId);
         }
 
+        BlockPlaceContext blockPlaceContext = new BlockPlaceContext(player, hand, player.getItemInHand(hand), blockHit);
+
         if (!blockHit.getLocation().equals(Vec3.ZERO)) {
             org.bukkit.inventory.ItemStack heldItem;
             if (hand == InteractionHand.MAIN_HAND) {
@@ -126,12 +136,30 @@ public class SetBlockPacketListener implements PluginMessageListener {
             if (!playerInteractEvent.callEvent()) {
                 return;
             }
+
+            // Call BlockMultiPlace / BlockPlace event
+            List<org.bukkit.block.BlockState> blockStates = new ArrayList<>();
+            for (Map.Entry<BlockPos, BlockState> entry : blocks.entrySet()) {
+                blockStates.add(CraftBlockStates.getBlockState(entry.getKey(), entry.getValue(), null));
+            }
+
+            Cancellable event = null;
+            if (blockStates.size() > 1) {
+                event = CraftEventFactory.callBlockMultiPlaceEvent(player.serverLevel(),
+                    player, hand, blockStates, blockHit.getBlockPos().getX(),
+                    blockHit.getBlockPos().getY(), blockHit.getBlockPos().getZ());
+            } else if (blockStates.size() == 1) {
+                event = CraftEventFactory.callBlockPlaceEvent(player.serverLevel(),
+                    player, hand, blockStates.get(0), blockHit.getBlockPos().getX(),
+                    blockHit.getBlockPos().getY(), blockHit.getBlockPos().getZ());
+            }
+            if (event != null && event.isCancelled()) {
+                return;
+            }
         }
 
         CraftWorld world = player.level().getWorld();
 
-        BlockPlaceContext blockPlaceContext = new BlockPlaceContext(player, hand, player.getItemInHand(hand), blockHit);
-
         // Update blocks
         if (updateNeighbors) {
             int count = 0;

src/main/java/com/moulberry/axiom/packet/UpdateAnnotationPacketListener.java

@@ -0,0 +1,57 @@
+package com.moulberry.axiom.packet;
+
+import com.moulberry.axiom.AxiomPaper;
+import com.moulberry.axiom.annotations.AnnotationUpdateAction;
+import com.moulberry.axiom.annotations.ServerAnnotations;
+import com.moulberry.axiom.blueprint.BlueprintIo;
+import com.moulberry.axiom.blueprint.RawBlueprint;
+import com.moulberry.axiom.blueprint.ServerBlueprintManager;
+import com.moulberry.axiom.blueprint.ServerBlueprintRegistry;
+import net.minecraft.SharedConstants;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.chat.Component;
+import net.minecraft.server.level.ServerPlayer;
+
+import java.io.BufferedOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+public class UpdateAnnotationPacketListener {
+
+    private final AxiomPaper plugin;
+    public UpdateAnnotationPacketListener(AxiomPaper plugin) {
+        this.plugin = plugin;
+    }
+
+    public void onReceive(ServerPlayer serverPlayer, FriendlyByteBuf friendlyByteBuf) {
+        if (!this.plugin.allowAnnotations || !this.plugin.canUseAxiom(serverPlayer.getBukkitEntity(), "axiom.annotation.create")) {
+            friendlyByteBuf.writerIndex(friendlyByteBuf.readerIndex());
+            return;
+        }
+
+        // Read actions
+        int length = friendlyByteBuf.readVarInt();
+        List<AnnotationUpdateAction> actions = new ArrayList<>(Math.min(256, length));
+        for (int i = 0; i < length; i++) {
+            AnnotationUpdateAction action = AnnotationUpdateAction.read(friendlyByteBuf);
+            if (action != null) {
+                actions.add(action);
+            }
+        }
+
+        // Execute
+        serverPlayer.getServer().execute(() -> {
+            try {
+                ServerAnnotations.handleUpdates(serverPlayer.serverLevel().getWorld(), actions);
+            } catch (Throwable t) {
+                serverPlayer.getBukkitEntity().kick(net.kyori.adventure.text.Component.text(
+                        "An error occured while updating annotations: " + t.getMessage()));
+            }
+        });
+    }
+
+}

src/main/java/com/moulberry/axiom/packet/UploadBlueprintPacketListener.java

@@ -25,6 +25,7 @@ public class UploadBlueprintPacketListener  {
 
     public void onReceive(ServerPlayer serverPlayer, FriendlyByteBuf friendlyByteBuf) {
         if (!this.plugin.canUseAxiom(serverPlayer.getBukkitEntity(), "axiom.blueprint.upload")) {
+            friendlyByteBuf.writerIndex(friendlyByteBuf.readerIndex());
             return;
         }
 

src/main/resources/config.yml

@@ -18,12 +18,10 @@ blueprint-sharing: false
 allow-large-chunk-data-request: false
 
 # Action to take when a user with an incompatible Minecraft version or Axiom version joins
-# Valid actions are 'kick', 'warn' and 'ignore'
+# Valid actions are 'kick' and 'warn'
 # 'warn' will give the player a warning and disable Axiom
-# Using 'ignore' may result in corruption and is only provided for debugging purposes
 incompatible-data-version: "warn"
 unsupported-axiom-version: "warn"
-client-doesnt-support-restrictions: "ignore"
 
 # Maximum packet size. Must not be less than 32767
 max-block-buffer-packet-size: 0x100000
@@ -59,11 +57,28 @@ blacklist-entities:
 # True allows players to see/manipulate marker entities
 send-markers: false
 
+# True to enable Annotations on this server
+allow-annotations: false
+
 # Disallowed blocks
 disallowed-blocks:
 #  - "minecraft:wheat"
 #  - "minecraft:oak_stairs[waterlogged=true]"
 
+allow-capabilities:
+  - "all"
+  # - "bulldozer"
+  # - "replace_mode"
+  # - "force_place"
+  # - "no_updates"
+  # - "tinker"
+  # - "infinite_reach"
+  # - "fast_place"
+  # - "angel_placement"
+  # - "no_clip"
+
+infinite-reach-limit: 256
+
 # Toggles for individual packet handlers. May break certain features
 packet-handlers:
   hello: true

src/main/resources/plugin.yml

@@ -32,6 +32,12 @@ permissions:
       axiom.blueprint.upload: true
       axiom.blueprint.request: true
       axiom.blueprint.manifest: true
+  axiom.annotation.*:
+    description: Allows creating and viewing annotations
+    default: op
+    children:
+      axiom.annotation.create: true
+      axiom.annotation.view: true
   axiom.chunk.*:
     description: Allows use of all chunk-related features
     default: op