Allow mannequins to inherit server teams

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_9to1_21_7/rewriter/EntityPacketRewriter1_21_9.java

@@ -23,6 +23,7 @@
 import com.viaversion.viabackwards.api.rewriters.EntityRewriter;
 import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.Protocol1_21_9To1_21_7;
 import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.storage.MannequinData;
+import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.storage.MannequinTeamStorage;
 import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.storage.PlayerRotationStorage;
 import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.storage.ProtocolStorables1_21_9;
 import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.tracker.EntityTracker1_21_9;
@@ -50,10 +51,8 @@
 import com.viaversion.viaversion.rewriter.entitydata.EntityDataHandler;
 import com.viaversion.viaversion.util.ChatColorUtil;
 import com.viaversion.viaversion.util.Copyable;
-import java.util.BitSet;
-import java.util.List;
-import java.util.Map;
-import java.util.UUID;
+
+import java.util.*;
 import java.util.concurrent.ThreadLocalRandom;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
@@ -157,6 +156,32 @@ public void registerPackets() {
             } while (slot < 0);
         });
 
+        protocol.appendClientbound(ClientboundPackets1_21_9.SET_PLAYER_TEAM, wrapper -> {
+            final String teamName = wrapper.get(Types.STRING, 0);
+            final byte action = wrapper.get(Types.BYTE, 0);
+            final ProtocolStorables1_21_9 storables = wrapper.user().storables(protocol);
+            final MannequinTeamStorage storage = storables.mannequinTeamStorage();
+            if (action == 1) {
+                final List<String> mannequins = storables.mannequinTeamStorage().removeTeam(teamName);
+                for (String name : mannequins) {
+                    storage.setFakeTeam(wrapper.user(), name);
+                }
+            } else if (action != 2) {
+                final String[] entries = wrapper.passthrough(Types.STRING_ARRAY);
+                final String newTeam = action != 4 ? teamName : null;
+                for (int i = 0; i < entries.length; i++) {
+                    final String rewritten = storage.changeTeamAndRewrite(newTeam, entries[i]);
+                    if (rewritten == null) {
+                        continue;
+                    }
+                    entries[i] = rewritten;
+                    if (newTeam == null) {
+                        storage.setFakeTeam(wrapper.user(), rewritten);
+                    }
+                }
+            }
+        });
+
         // Back to more non-mannequin things
         protocol.registerClientbound(ClientboundPackets1_21_9.SET_ENTITY_MOTION, wrapper -> {
             wrapper.passthrough(Types.VAR_INT); // Entity ID
@@ -276,7 +301,20 @@ private void sendInitialPlayerInfoUpdate(final UserConnection connection, final
         playerInfo.write(Types.BOOLEAN, true); // Show hat
         playerInfo.send(Protocol1_21_9To1_21_7.class);
 
-        sendPlayerTeamDisplayName(connection, mannequinData, mannequinData.displayName());
+        final ProtocolStorables1_21_9 storables = connection.storables(protocol);
+        final String serverTeam = storables.mannequinTeamStorage().registerMannequin(mannequinData, mannequinData.name());
+        if (serverTeam == null || !mannequinData.hasTeam()) {
+            // Still create the mannequin team even if server has team, so we can set it later if needed
+            sendPlayerTeamDisplayName(connection, mannequinData, mannequinData.displayName());
+        }
+        if (serverTeam != null) {
+            // Server had a team for this entity already, but players want names
+            final PacketWrapper setTeam = PacketWrapper.create(ClientboundPackets1_21_6.SET_PLAYER_TEAM, connection);
+            setTeam.write(Types.STRING, serverTeam);
+            setTeam.write(Types.BYTE, (byte) 3); // Add entities
+            setTeam.write(Types.STRING_ARRAY, new String[] { mannequinData.name() });
+            setTeam.send(Protocol1_21_9To1_21_7.class);
+        }
     }
 
     private void sendPlayerInfoDisplayNameUpdate(final UserConnection connection, final MannequinData mannequinData, @Nullable final Tag displayName) {
@@ -294,16 +332,16 @@ private void sendPlayerInfoDisplayNameUpdate(final UserConnection connection, fi
 
     private void sendPlayerTeamDisplayName(final UserConnection connection, final MannequinData mannequinData, final Tag displayName) {
         // Send the display name as a team prefix
-        final Tag nonNullDisplayName = displayName != null ? displayName : new StringTag("Mannequin");
+        boolean showName = displayName != null && (!(displayName instanceof StringTag str) || !str.getValue().isEmpty());
         final PacketWrapper addTeam = PacketWrapper.create(ClientboundPackets1_21_6.SET_PLAYER_TEAM, connection);
         addTeam.write(Types.STRING, mannequinData.name());
         addTeam.write(Types.BYTE, mannequinData.hasTeam() ? (byte) 2 : 0); // Mode
-        addTeam.write(Types.TRUSTED_TAG, nonNullDisplayName); // Display Name
+        addTeam.write(Types.TRUSTED_TAG, displayName != null ? displayName : new StringTag("Mannequin")); // Display Name
         addTeam.write(Types.BYTE, (byte) 0); // Flags
-        addTeam.write(Types.VAR_INT, 0); // Nametag visibility
+        addTeam.write(Types.VAR_INT, showName ? 0 : 1); // Nametag visibility
         addTeam.write(Types.VAR_INT, 0); // Collision rule
         addTeam.write(Types.VAR_INT, 15); // Color
-        addTeam.write(Types.TRUSTED_TAG, nonNullDisplayName); // Prefix
+        addTeam.write(Types.TRUSTED_TAG, displayName != null ? displayName : new StringTag("")); // Prefix
         addTeam.write(Types.TRUSTED_TAG, new StringTag("")); // Suffix
         if (!mannequinData.hasTeam()) {
             addTeam.write(Types.STRING_ARRAY, new String[]{mannequinData.name()});

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_9to1_21_7/storage/MannequinTeamStorage.java

@@ -0,0 +1,145 @@
+/*
+ * This file is part of ViaBackwards - https://github.com/ViaVersion/ViaBackwards
+ * Copyright (C) 2016-2026 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.storage;
+
+import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.Protocol1_21_9To1_21_7;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.protocols.v1_21_5to1_21_6.packet.ClientboundPackets1_21_6;
+
+import java.util.*;
+
+public class MannequinTeamStorage {
+  private final Map<UUID, ScoreboardEntity> scoreboardEntities = new HashMap<>();
+  private final Map<String, List<ScoreboardEntity>> entitiesByTeam = new HashMap<>();
+
+  /**
+   * Called when the server changes the team for an entity.
+   *
+   * <p>Attempts to find known mannequins by the UUID in the entry. If not found,
+   * it stores the team association in case a mannequin with that UUID does spawn.
+   *
+   * @param newTeam the new team, or {@code null} to leave the team
+   * @param entry the raw entry from the server
+   * @return the mannequin/player name for this entry if it should be rewritten, {@code null} otherwise
+   */
+  public String changeTeamAndRewrite(String newTeam, String entry) {
+    UUID uuid;
+    // Only consider entity UUIDs, the server uses those to assign teams to mannequins,
+    // but we need player names for scoreboard teams
+    if (entry.length() != 36) {
+      return null;
+    }
+    try {
+      uuid = UUID.fromString(entry);
+    } catch (IllegalArgumentException ignored) {
+      return null;
+    }
+
+    ScoreboardEntity entity = scoreboardEntities.get(uuid);
+    if (entity == null) {
+      if (newTeam == null) {
+        // Untracked entity removed from team, we don't care
+        return null;
+      }
+      entity = new ScoreboardEntity(uuid);
+      scoreboardEntities.put(uuid, entity);
+    }
+
+    changeServerTeam(entity, newTeam);
+
+    if (newTeam == null && !entity.isMannequin()) {
+      // Remove the team registration but only forget the entity
+      // now if not a mannequin. Keep entry until the mannequin is
+      // despawned, in case server sends another team
+      scoreboardEntities.remove(uuid);
+    }
+
+    return entity.mannequinName;
+  }
+
+  private void changeServerTeam(ScoreboardEntity entity, String newTeam) {
+    if (entity.serverTeam != null) {
+      final List<ScoreboardEntity> oldTeam = entitiesByTeam.get(entity.serverTeam);
+      if (oldTeam != null) {
+        oldTeam.remove(entity);
+      }
+    }
+    entity.serverTeam = newTeam;
+    if (newTeam != null) {
+      entitiesByTeam.computeIfAbsent(newTeam, $ -> new ArrayList<>()).add(entity);
+    }
+  }
+
+  public List<String> removeTeam(String teamName) {
+    final List<ScoreboardEntity> entities = entitiesByTeam.remove(teamName);
+    if (entities == null) {
+      return List.of();
+    }
+    final List<String> result = new ArrayList<>();
+    for (ScoreboardEntity entity : entities) {
+      scoreboardEntities.remove(entity.uuid);
+      if (entity.isMannequin()) {
+        result.add(entity.mannequinName);
+      }
+    }
+    return result;
+  }
+
+  public String registerMannequin(MannequinData data, String playerName) {
+    // If server set team before mannequin spawned, scoreboardEntities has it. Otherwise,
+    // we still register the entity so that future team changes recognize the entity as a mannequin
+    final ScoreboardEntity entity = scoreboardEntities.computeIfAbsent(data.uuid(), ScoreboardEntity::new);
+    entity.mannequinName = playerName;
+    return entity.serverTeam;
+  }
+
+  public void unregisterMannequin(MannequinData data) {
+    final ScoreboardEntity entity = scoreboardEntities.get(data.uuid());
+    if (entity != null && entity.serverTeam == null) {
+      // Remove lingering mannequin entry with no server team that was waiting
+      // for the mannequin to despawn
+      scoreboardEntities.remove(data.uuid());
+    }
+  }
+
+  public void setFakeTeam(UserConnection connection, String mannequinName) {
+    // Mannequin was removed from server team, apply our fake team again
+    final PacketWrapper setTeam = PacketWrapper.create(ClientboundPackets1_21_6.SET_PLAYER_TEAM, connection);
+    setTeam.write(Types.STRING, mannequinName);
+    setTeam.write(Types.BYTE, (byte) 3); // Add entities
+    setTeam.write(Types.STRING_ARRAY, new String[]{mannequinName});
+    setTeam.send(Protocol1_21_9To1_21_7.class);
+  }
+
+  private static class ScoreboardEntity {
+    private final UUID uuid;
+    private String serverTeam;
+    // Set to VB's mannequin team name (= mannequin profile name) if entity is a known mannequin, null otherwise
+    private String mannequinName;
+
+    private ScoreboardEntity(UUID uuid) {
+      this.uuid = uuid;
+    }
+
+    private boolean isMannequin() {
+      return mannequinName != null;
+    }
+  }
+}

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_9to1_21_7/storage/ProtocolStorables1_21_9.java

@@ -25,6 +25,7 @@ public final class ProtocolStorables1_21_9 extends ProtocolStorablesBase {
     private final PlayerRotationStorage playerRotationStorage = new PlayerRotationStorage();
     private final DimensionScaleStorage dimensionScaleStorage = new DimensionScaleStorage();
     private final BundleStateTracker bundleStateTracker = new BundleStateTracker();
+    private final MannequinTeamStorage mannequinTeamStorage = new MannequinTeamStorage();
 
     public PlayerRotationStorage playerRotationStorage() {
         return playerRotationStorage;
@@ -37,4 +38,8 @@ public DimensionScaleStorage dimensionScaleStorage() {
     public BundleStateTracker bundleStateTracker() {
         return bundleStateTracker;
     }
+
+    public MannequinTeamStorage mannequinTeamStorage() {
+        return mannequinTeamStorage;
+    }
 }

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_9to1_21_7/tracker/EntityTracker1_21_9.java

@@ -19,6 +19,7 @@
 
 import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.Protocol1_21_9To1_21_7;
 import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.storage.MannequinData;
+import com.viaversion.viabackwards.protocol.v1_21_9to1_21_7.storage.ProtocolStorables1_21_9;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.data.entity.TrackedEntity;
 import com.viaversion.viaversion.api.minecraft.entities.EntityType;
@@ -47,6 +48,9 @@ public EntityTracker1_21_9(final UserConnection connection, @Nullable final Enti
     public void sendRemovePacket(final TrackedEntity entity) {
         final MannequinData trackedEntityId = entity.get(MannequinData.class);
         if (trackedEntityId != null) {
+            final ProtocolStorables1_21_9 storables = user().storables(Protocol1_21_9To1_21_7.class);
+            storables.mannequinTeamStorage().unregisterMannequin(trackedEntityId);
+
             final PacketWrapper playerInfoRemove = PacketWrapper.create(ClientboundPackets1_21_6.PLAYER_INFO_REMOVE, user());
             playerInfoRemove.write(Types.UUID_ARRAY, new UUID[]{trackedEntityId.uuid()});
             playerInfoRemove.send(Protocol1_21_9To1_21_7.class);