WIP 24w33a

common/src/main/java/com/viaversion/viabackwards/api/ViaBackwardsPlatform.java

@@ -54,6 +54,7 @@ import com.viaversion.viabackwards.protocol.v1_19_1to1_19.Protocol1_19_1To1_19;
 import com.viaversion.viabackwards.protocol.v1_20_3to1_20_2.Protocol1_20_3To1_20_2;
 import com.viaversion.viabackwards.protocol.v1_20_5to1_20_3.Protocol1_20_5To1_20_3;
 import com.viaversion.viabackwards.protocol.v1_20_2to1_20.Protocol1_20_2To1_20;
+import com.viaversion.viabackwards.protocol.v1_21_2to1_21.Protocol1_21_2To1_21;
 import com.viaversion.viabackwards.protocol.v1_21to1_20_5.Protocol1_21To1_20_5;
 import com.viaversion.viabackwards.protocol.v1_9_3to1_9_1.Protocol1_9_3To1_9_1;
 import com.viaversion.viabackwards.protocol.v1_10to1_9_3.Protocol1_10To1_9_3;
@@ -141,6 +142,7 @@ public interface ViaBackwardsPlatform {
         protocolManager.registerProtocol(new Protocol1_20_5To1_20_3(), ProtocolVersion.v1_20_3, ProtocolVersion.v1_20_5);
 
         protocolManager.registerProtocol(new Protocol1_21To1_20_5(), ProtocolVersion.v1_20_5, ProtocolVersion.v1_21);
+        protocolManager.registerProtocol(new Protocol1_21_2To1_21(), ProtocolVersion.v1_21, ProtocolVersion.v1_21_2);
     }
 
     /**

common/src/main/java/com/viaversion/viabackwards/protocol/template/BlockItemPacketRewriter1_99.java

@@ -20,11 +20,11 @@ package com.viaversion.viabackwards.protocol.template;
 import com.viaversion.viabackwards.api.rewriters.BackwardsStructuredItemRewriter;
 import com.viaversion.viaversion.api.type.types.chunk.ChunkType1_20_2;
 import com.viaversion.viaversion.api.type.types.version.Types1_21;
-import com.viaversion.viaversion.protocols.v1_20_2to1_20_3.rewriter.RecipeRewriter1_20_3;
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPacket1_20_5;
 import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPackets1_20_5;
 import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundPacket1_21;
 import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundPackets1_21;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.rewriter.RecipeRewriter1_21_2;
 import com.viaversion.viaversion.rewriter.BlockRewriter;
 
 // To replace if needed:
@@ -52,19 +52,19 @@ final class BlockItemPacketRewriter1_99 extends BackwardsStructuredItemRewriter<
         blockRewriter.registerLevelChunk1_19(ClientboundPackets1_21.LEVEL_CHUNK_WITH_LIGHT, ChunkType1_20_2::new);
         blockRewriter.registerBlockEntityData(ClientboundPackets1_21.BLOCK_ENTITY_DATA);
 
-        // registerOpenWindow(ClientboundPackets1_21.OPEN_WINDOW);
+        // registerOpenScreen(ClientboundPackets1_21.OPEN_SCREEN);
         registerCooldown(ClientboundPackets1_21.COOLDOWN);
-        registerSetContent1_17_1(ClientboundPackets1_21.CONTAINER_SET_CONTENT);
+        registerSetContent1_21_2(ClientboundPackets1_21.CONTAINER_SET_CONTENT);
-        registerSetSlot1_17_1(ClientboundPackets1_21.CONTAINER_SET_SLOT);
+        registerSetSlot1_21_2(ClientboundPackets1_21.CONTAINER_SET_SLOT);
         registerAdvancements1_20_3(ClientboundPackets1_21.UPDATE_ADVANCEMENTS);
         registerSetEquipment(ClientboundPackets1_21.SET_EQUIPMENT);
-        registerContainerClick1_17_1(ServerboundPackets1_20_5.CONTAINER_CLICK);
+        registerContainerClick1_21_2(ServerboundPackets1_20_5.CONTAINER_CLICK);
         registerMerchantOffers1_20_5(ClientboundPackets1_21.MERCHANT_OFFERS);
         registerSetCreativeModeSlot(ServerboundPackets1_20_5.SET_CREATIVE_MODE_SLOT);
         registerContainerSetData(ClientboundPackets1_21.CONTAINER_SET_DATA);
         registerLevelParticles1_20_5(ClientboundPackets1_21.LEVEL_PARTICLES);
-        registerExplosion(ClientboundPackets1_21.EXPLODE);
+        registerExplosion1_21_2(ClientboundPackets1_21.EXPLODE);
 
-        new RecipeRewriter1_20_3<>(protocol).register1_20_5(ClientboundPackets1_21.UPDATE_RECIPES);
+        new RecipeRewriter1_21_2<>(protocol).register1_20_5(ClientboundPackets1_21.UPDATE_RECIPES);
     }
 }

common/src/main/java/com/viaversion/viabackwards/protocol/template/EntityPacketRewriter1_99.java

@@ -66,6 +66,7 @@ final class EntityPacketRewriter1_99 extends EntityRewriter<ClientboundPacket1_2
                 map(Types.VAR_INT); // Dimension key
                 map(Types.STRING); // World
                 handler(worldDataTrackerHandlerByKey1_20_5(3)); // Tracks world height and name for chunk data and entity (un)tracking
+                handler(playerTrackerHandler());
             }
         });
 

common/src/main/java/com/viaversion/viabackwards/protocol/template/Protocol1_98To1_99.java

@@ -74,10 +74,10 @@ final class Protocol1_98To1_99 extends BackwardsProtocol<ClientboundPacket1_21,
         soundRewriter.registerStopSound(ClientboundPackets1_21.STOP_SOUND);
 
         new StatisticsRewriter<>(this).register(ClientboundPackets1_21.AWARD_STATS);
-        //new AttributeRewriter<>(this).register1_21(ClientboundPackets1_21.ENTITY_PROPERTIES);
+        //new AttributeRewriter<>(this).register1_21(ClientboundPackets1_21.UPDATE_ATTRIBUTES);
 
         // Registers translatable mappings (missing a whole bunch still)
-        //translatableRewriter.registerOpenWindow(ClientboundPackets1_21.OPEN_WINDOW); // Handled by registerOpenWindow in item rewriters
+        //translatableRewriter.registerOpenScreen(ClientboundPackets1_21.OPEN_SCREEN); // Handled by registerOpenScreen in item rewriters
         translatableRewriter.registerComponentPacket(ClientboundPackets1_21.SET_ACTION_BAR_TEXT);
         translatableRewriter.registerComponentPacket(ClientboundPackets1_21.SET_TITLE_TEXT);
         translatableRewriter.registerComponentPacket(ClientboundPackets1_21.SET_SUBTITLE_TEXT);

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_2to1_21/Protocol1_21_2To1_21.java

@@ -0,0 +1,146 @@
+/*
+ * This file is part of ViaBackwards - https://github.com/ViaVersion/ViaBackwards
+ * Copyright (C) 2016-2024 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_2to1_21;
+
+import com.viaversion.viabackwards.api.BackwardsProtocol;
+import com.viaversion.viabackwards.api.data.BackwardsMappingData;
+import com.viaversion.viabackwards.api.rewriters.SoundRewriter;
+import com.viaversion.viabackwards.api.rewriters.TranslatableRewriter;
+import com.viaversion.viabackwards.protocol.v1_21_2to1_21.rewriter.BlockItemPacketRewriter1_21_2;
+import com.viaversion.viabackwards.protocol.v1_21_2to1_21.rewriter.EntityPacketRewriter1_21_2;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.entities.EntityTypes1_20_5;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.protocol.packet.provider.PacketTypesProvider;
+import com.viaversion.viaversion.api.protocol.packet.provider.SimplePacketTypesProvider;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.data.entity.EntityTrackerBase;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundConfigurationPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundConfigurationPackets1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundPacket1_21;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.Protocol1_21To1_21_2;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ClientboundPacket1_21_2;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ClientboundPackets1_21_2;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ServerboundPacket1_21_2;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ServerboundPackets1_21_2;
+import com.viaversion.viaversion.rewriter.AttributeRewriter;
+import com.viaversion.viaversion.rewriter.ComponentRewriter.ReadType;
+import com.viaversion.viaversion.rewriter.StatisticsRewriter;
+import com.viaversion.viaversion.rewriter.TagRewriter;
+
+import static com.viaversion.viaversion.util.ProtocolUtil.packetTypeMap;
+
+public final class Protocol1_21_2To1_21 extends BackwardsProtocol<ClientboundPacket1_21_2, ClientboundPacket1_21, ServerboundPacket1_21_2, ServerboundPacket1_20_5> {
+
+    public static final BackwardsMappingData MAPPINGS = new BackwardsMappingData("1.21.2", "1.21", Protocol1_21To1_21_2.class);
+    private final EntityPacketRewriter1_21_2 entityRewriter = new EntityPacketRewriter1_21_2(this);
+    private final BlockItemPacketRewriter1_21_2 itemRewriter = new BlockItemPacketRewriter1_21_2(this);
+    private final TranslatableRewriter<ClientboundPacket1_21_2> translatableRewriter = new TranslatableRewriter<>(this, ReadType.NBT);
+    private final TagRewriter<ClientboundPacket1_21_2> tagRewriter = new TagRewriter<>(this);
+
+    public Protocol1_21_2To1_21() {
+        super(ClientboundPacket1_21_2.class, ClientboundPacket1_21.class, ServerboundPacket1_21_2.class, ServerboundPacket1_20_5.class);
+    }
+
+    @Override
+    protected void registerPackets() {
+        super.registerPackets();
+
+        tagRewriter.registerGeneric(ClientboundPackets1_21_2.UPDATE_TAGS);
+        tagRewriter.registerGeneric(ClientboundConfigurationPackets1_21.UPDATE_TAGS);
+
+        final SoundRewriter<ClientboundPacket1_21_2> soundRewriter = new SoundRewriter<>(this);
+        soundRewriter.registerSound1_19_3(ClientboundPackets1_21_2.SOUND);
+        soundRewriter.registerSound1_19_3(ClientboundPackets1_21_2.SOUND_ENTITY);
+        soundRewriter.registerStopSound(ClientboundPackets1_21_2.STOP_SOUND);
+
+        new StatisticsRewriter<>(this).register(ClientboundPackets1_21_2.AWARD_STATS);
+        new AttributeRewriter<>(this).register1_21(ClientboundPackets1_21_2.UPDATE_ATTRIBUTES);
+
+        translatableRewriter.registerOpenScreen(ClientboundPackets1_21_2.OPEN_SCREEN);
+        translatableRewriter.registerComponentPacket(ClientboundPackets1_21_2.SET_ACTION_BAR_TEXT);
+        translatableRewriter.registerComponentPacket(ClientboundPackets1_21_2.SET_TITLE_TEXT);
+        translatableRewriter.registerComponentPacket(ClientboundPackets1_21_2.SET_SUBTITLE_TEXT);
+        translatableRewriter.registerBossEvent(ClientboundPackets1_21_2.BOSS_EVENT);
+        translatableRewriter.registerComponentPacket(ClientboundPackets1_21_2.DISCONNECT);
+        translatableRewriter.registerTabList(ClientboundPackets1_21_2.TAB_LIST);
+        translatableRewriter.registerPlayerCombatKill1_20(ClientboundPackets1_21_2.PLAYER_COMBAT_KILL);
+        translatableRewriter.registerComponentPacket(ClientboundPackets1_21_2.SYSTEM_CHAT);
+        translatableRewriter.registerComponentPacket(ClientboundPackets1_21_2.DISGUISED_CHAT);
+        translatableRewriter.registerPing();
+
+        registerServerbound(ServerboundPackets1_20_5.CLIENT_INFORMATION, this::clientInformation);
+        registerServerbound(ServerboundConfigurationPackets1_20_5.CLIENT_INFORMATION, this::clientInformation);
+
+        cancelClientbound(ClientboundPackets1_21_2.MOVE_MINECART_ALONG_TRACK); // TODO
+    }
+
+    private void clientInformation(final PacketWrapper wrapper) {
+        wrapper.passthrough(Types.STRING); // Locale
+        wrapper.passthrough(Types.BYTE); // View distance
+        wrapper.passthrough(Types.VAR_INT); // Chat visibility
+        wrapper.passthrough(Types.BOOLEAN); // Chat colors
+        wrapper.passthrough(Types.BYTE); // Skin parts
+        wrapper.passthrough(Types.VAR_INT); // Main hand
+        wrapper.passthrough(Types.BOOLEAN); // Text filtering enabled
+        wrapper.passthrough(Types.BOOLEAN); // Allow listing
+        wrapper.write(Types.VAR_INT, 0); // Particle status, assume 'all'
+    }
+
+    @Override
+    public void init(final UserConnection user) {
+        addEntityTracker(user, new EntityTrackerBase(user, EntityTypes1_20_5.PLAYER));
+    }
+
+    @Override
+    public BackwardsMappingData getMappingData() {
+        return MAPPINGS;
+    }
+
+    @Override
+    public EntityPacketRewriter1_21_2 getEntityRewriter() {
+        return entityRewriter;
+    }
+
+    @Override
+    public BlockItemPacketRewriter1_21_2 getItemRewriter() {
+        return itemRewriter;
+    }
+
+    @Override
+    public TranslatableRewriter<ClientboundPacket1_21_2> getComponentRewriter() {
+        return translatableRewriter;
+    }
+
+    @Override
+    public TagRewriter<ClientboundPacket1_21_2> getTagRewriter() {
+        return tagRewriter;
+    }
+
+    @Override
+    protected PacketTypesProvider<ClientboundPacket1_21_2, ClientboundPacket1_21, ServerboundPacket1_21_2, ServerboundPacket1_20_5> createPacketTypesProvider() {
+        return new SimplePacketTypesProvider<>(
+            packetTypeMap(unmappedClientboundPacketType, ClientboundPackets1_21_2.class, ClientboundConfigurationPackets1_21.class),
+            packetTypeMap(mappedClientboundPacketType, ClientboundPacket1_21.class, ClientboundConfigurationPackets1_21.class),
+            packetTypeMap(mappedServerboundPacketType, ServerboundPackets1_21_2.class, ServerboundConfigurationPackets1_20_5.class),
+            packetTypeMap(unmappedServerboundPacketType, ServerboundPackets1_20_5.class, ServerboundConfigurationPackets1_20_5.class)
+        );
+    }
+}

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_2to1_21/rewriter/BlockItemPacketRewriter1_21_2.java

@@ -0,0 +1,136 @@
+/*
+ * This file is part of ViaBackwards - https://github.com/ViaVersion/ViaBackwards
+ * Copyright (C) 2016-2024 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_2to1_21.rewriter;
+
+import com.viaversion.viabackwards.api.rewriters.BackwardsStructuredItemRewriter;
+import com.viaversion.viabackwards.protocol.v1_21_2to1_21.Protocol1_21_2To1_21;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.chunk.ChunkType1_20_2;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
+import com.viaversion.viaversion.api.type.types.version.Types1_21_2;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundPackets1_21;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ClientboundPacket1_21_2;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ClientboundPackets1_21_2;
+import com.viaversion.viaversion.rewriter.BlockRewriter;
+
+import static com.viaversion.viaversion.protocols.v1_21to1_21_2.rewriter.BlockItemPacketRewriter1_21_2.downgradeItemData;
+import static com.viaversion.viaversion.protocols.v1_21to1_21_2.rewriter.BlockItemPacketRewriter1_21_2.updateItemData;
+
+public final class BlockItemPacketRewriter1_21_2 extends BackwardsStructuredItemRewriter<ClientboundPacket1_21_2, ServerboundPacket1_20_5, Protocol1_21_2To1_21> {
+
+    public BlockItemPacketRewriter1_21_2(final Protocol1_21_2To1_21 protocol) {
+        super(protocol,
+            Types1_21_2.ITEM, Types1_21_2.ITEM_ARRAY, Types1_21.ITEM, Types1_21.ITEM_ARRAY,
+            Types1_21_2.ITEM_COST, Types1_21_2.OPTIONAL_ITEM_COST, Types1_21.ITEM_COST, Types1_21.OPTIONAL_ITEM_COST,
+            Types1_21_2.PARTICLE, Types1_21.PARTICLE
+        );
+    }
+
+    @Override
+    public void registerPackets() {
+        final BlockRewriter<ClientboundPacket1_21_2> blockRewriter = BlockRewriter.for1_20_2(protocol);
+        blockRewriter.registerBlockEvent(ClientboundPackets1_21_2.BLOCK_EVENT);
+        blockRewriter.registerBlockUpdate(ClientboundPackets1_21_2.BLOCK_UPDATE);
+        blockRewriter.registerSectionBlocksUpdate1_20(ClientboundPackets1_21_2.SECTION_BLOCKS_UPDATE);
+        blockRewriter.registerLevelEvent1_21(ClientboundPackets1_21_2.LEVEL_EVENT, 2001);
+        blockRewriter.registerLevelChunk1_19(ClientboundPackets1_21_2.LEVEL_CHUNK_WITH_LIGHT, ChunkType1_20_2::new);
+        blockRewriter.registerBlockEntityData(ClientboundPackets1_21_2.BLOCK_ENTITY_DATA);
+
+        registerCooldown(ClientboundPackets1_21_2.COOLDOWN);
+        registerAdvancements1_20_3(ClientboundPackets1_21_2.UPDATE_ADVANCEMENTS);
+        registerSetEquipment(ClientboundPackets1_21_2.SET_EQUIPMENT);
+        registerMerchantOffers1_20_5(ClientboundPackets1_21_2.MERCHANT_OFFERS);
+        registerSetCreativeModeSlot(ServerboundPackets1_20_5.SET_CREATIVE_MODE_SLOT);
+        registerLevelParticles1_20_5(ClientboundPackets1_21_2.LEVEL_PARTICLES);
+        registerExplosion1_21_2(ClientboundPackets1_21_2.EXPLODE);
+
+        protocol.registerClientbound(ClientboundPackets1_21_2.CONTAINER_SET_CONTENT, wrapper -> {
+            updateContainerId(wrapper);
+            wrapper.passthrough(Types.VAR_INT); // State id
+            Item[] items = wrapper.read(itemArrayType());
+            wrapper.write(mappedItemArrayType(), items);
+            for (int i = 0; i < items.length; i++) {
+                items[i] = handleItemToClient(wrapper.user(), items[i]);
+            }
+            passthroughClientboundItem(wrapper);
+        });
+        protocol.registerClientbound(ClientboundPackets1_21_2.CONTAINER_SET_SLOT, wrapper -> {
+            updateContainerId(wrapper);
+            wrapper.passthrough(Types.VAR_INT); // State id
+            wrapper.passthrough(Types.SHORT); // Slot id
+            passthroughClientboundItem(wrapper);
+        });
+        protocol.registerClientbound(ClientboundPackets1_21_2.SET_HELD_SLOT, ClientboundPackets1_21.SET_CARRIED_ITEM);
+        protocol.registerClientbound(ClientboundPackets1_21_2.CONTAINER_CLOSE, this::updateContainerId);
+        protocol.registerClientbound(ClientboundPackets1_21_2.CONTAINER_SET_DATA, this::updateContainerId);
+        protocol.registerClientbound(ClientboundPackets1_21_2.HORSE_SCREEN_OPEN, this::updateContainerId);
+        protocol.registerClientbound(ClientboundPackets1_21_2.PLACE_GHOST_RECIPE, this::updateContainerId);
+        protocol.registerServerbound(ServerboundPackets1_20_5.CONTAINER_CLOSE, this::updateContainerIdServerbound);
+        protocol.registerServerbound(ServerboundPackets1_20_5.PLACE_RECIPE, this::updateContainerIdServerbound);
+        protocol.registerServerbound(ServerboundPackets1_20_5.CONTAINER_CLICK, wrapper -> {
+            updateContainerIdServerbound(wrapper);
+            wrapper.passthrough(Types.VAR_INT); // State id
+            wrapper.passthrough(Types.SHORT); // Slot
+            wrapper.passthrough(Types.BYTE); // Button
+            wrapper.passthrough(Types.VAR_INT); // Mode
+            final int length = wrapper.passthrough(Types.VAR_INT);
+            for (int i = 0; i < length; i++) {
+                wrapper.passthrough(Types.SHORT); // Slot
+                passthroughServerboundItem(wrapper);
+            }
+            passthroughServerboundItem(wrapper);
+        });
+
+        protocol.registerClientbound(ClientboundPackets1_21_2.SET_PLAYER_INVENTORY, ClientboundPackets1_21.CONTAINER_SET_SLOT, wrapper -> {
+            wrapper.write(Types.BYTE, (byte) -2); // Player inventory
+            wrapper.write(Types.VAR_INT, 0); // 0 state id
+            final int slot = wrapper.read(Types.VAR_INT);
+            wrapper.write(Types.SHORT, (short) slot);
+        });
+    }
+
+    private void updateContainerId(final PacketWrapper wrapper) {
+        final int containerId = wrapper.read(Types.VAR_INT);
+        wrapper.write(Types.UNSIGNED_BYTE, (short) containerId);
+    }
+
+    private void updateContainerIdServerbound(final PacketWrapper wrapper) {
+        final short containerId = wrapper.read(Types.UNSIGNED_BYTE);
+        final int intId = (byte) containerId;
+        wrapper.write(Types.VAR_INT, intId);
+    }
+
+    @Override
+    public Item handleItemToClient(final UserConnection connection, final Item item) {
+        super.handleItemToClient(connection, item);
+        downgradeItemData(item);
+        return item;
+    }
+
+    @Override
+    public Item handleItemToServer(final UserConnection connection, final Item item) {
+        super.handleItemToServer(connection, item);
+        updateItemData(item);
+        return item;
+    }
+}

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_2to1_21/rewriter/EntityPacketRewriter1_21_2.java

@@ -0,0 +1,150 @@
+/*
+ * This file is part of ViaBackwards - https://github.com/ViaVersion/ViaBackwards
+ * Copyright (C) 2016-2024 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_2to1_21.rewriter;
+
+import com.viaversion.viabackwards.api.rewriters.EntityRewriter;
+import com.viaversion.viabackwards.protocol.v1_21_2to1_21.Protocol1_21_2To1_21;
+import com.viaversion.viaversion.api.minecraft.RegistryEntry;
+import com.viaversion.viaversion.api.minecraft.entities.EntityType;
+import com.viaversion.viaversion.api.minecraft.entities.EntityTypes1_20_5;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.protocol.remapper.PacketHandlers;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
+import com.viaversion.viaversion.api.type.types.version.Types1_21_2;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundConfigurationPackets1_21;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ClientboundPacket1_21_2;
+import com.viaversion.viaversion.protocols.v1_21to1_21_2.packet.ClientboundPackets1_21_2;
+import com.viaversion.viaversion.util.Key;
+
+import static com.viaversion.viaversion.protocols.v1_21to1_21_2.rewriter.EntityPacketRewriter1_21_2.updateEnchantmentAttributes;
+
+public final class EntityPacketRewriter1_21_2 extends EntityRewriter<ClientboundPacket1_21_2, Protocol1_21_2To1_21> {
+
+    public EntityPacketRewriter1_21_2(final Protocol1_21_2To1_21 protocol) {
+        super(protocol, Types1_21.ENTITY_DATA_TYPES.optionalComponentType, Types1_21.ENTITY_DATA_TYPES.booleanType);
+    }
+
+    @Override
+    public void registerPackets() {
+        registerTrackerWithData1_19(ClientboundPackets1_21_2.ADD_ENTITY, EntityTypes1_20_5.FALLING_BLOCK);
+        registerSetEntityData(ClientboundPackets1_21_2.SET_ENTITY_DATA, Types1_21_2.ENTITY_DATA_LIST, Types1_21.ENTITY_DATA_LIST);
+        registerRemoveEntities(ClientboundPackets1_21_2.REMOVE_ENTITIES);
+
+        protocol.registerClientbound(ClientboundConfigurationPackets1_21.REGISTRY_DATA, wrapper -> {
+            final String registryKey = Key.stripMinecraftNamespace(wrapper.passthrough(Types.STRING));
+            final RegistryEntry[] entries = wrapper.passthrough(Types.REGISTRY_ENTRY_ARRAY);
+            if (registryKey.equals("enchantment")) {
+                updateEnchantmentAttributes(entries, protocol.getMappingData().getAttributeMappings());
+            }
+
+            handleRegistryData1_20_5(wrapper.user(), registryKey, entries);
+        });
+
+        protocol.registerClientbound(ClientboundPackets1_21_2.LOGIN, new PacketHandlers() {
+            @Override
+            public void register() {
+                map(Types.INT); // Entity id
+                map(Types.BOOLEAN); // Hardcore
+                map(Types.STRING_ARRAY); // World List
+                map(Types.VAR_INT); // Max players
+                map(Types.VAR_INT); // View distance
+                map(Types.VAR_INT); // Simulation distance
+                map(Types.BOOLEAN); // Reduced debug info
+                map(Types.BOOLEAN); // Show death screen
+                map(Types.BOOLEAN); // Limited crafting
+                map(Types.VAR_INT); // Dimension key
+                map(Types.STRING); // World
+                map(Types.LONG); // Seed
+                map(Types.BYTE); // Gamemode
+                map(Types.BYTE); // Previous gamemode
+                map(Types.BOOLEAN); // Debug
+                map(Types.BOOLEAN); // Flat
+                map(Types.OPTIONAL_GLOBAL_POSITION); // Last death location
+                map(Types.VAR_INT); // Portal cooldown
+                handler(worldDataTrackerHandlerByKey1_20_5(3));
+                handler(playerTrackerHandler());
+                read(Types.VAR_INT); // Sea level
+            }
+        });
+
+        protocol.registerClientbound(ClientboundPackets1_21_2.RESPAWN, wrapper -> {
+            final int dimensionId = wrapper.passthrough(Types.VAR_INT);
+            final String world = wrapper.passthrough(Types.STRING);
+            wrapper.passthrough(Types.LONG); // Seed
+            wrapper.passthrough(Types.BYTE); // Gamemode
+            wrapper.passthrough(Types.BYTE); // Previous gamemode
+            wrapper.passthrough(Types.BOOLEAN); // Debug
+            wrapper.passthrough(Types.BOOLEAN); // Flat
+            wrapper.passthrough(Types.OPTIONAL_GLOBAL_POSITION); // Last death location
+            wrapper.passthrough(Types.VAR_INT); // Portal cooldown
+
+            wrapper.read(Types.VAR_INT); // Sea level
+            trackWorldDataByKey1_20_5(wrapper.user(), dimensionId, world);
+        });
+
+        protocol.appendServerbound(ServerboundPackets1_20_5.MOVE_PLAYER_POS, wrapper -> {
+            wrapper.passthrough(Types.DOUBLE); // X
+            wrapper.passthrough(Types.DOUBLE); // Y
+            wrapper.passthrough(Types.DOUBLE); // Z
+            fixOnGround(wrapper);
+        });
+        protocol.appendServerbound(ServerboundPackets1_20_5.MOVE_PLAYER_POS_ROT, wrapper -> {
+            wrapper.passthrough(Types.DOUBLE); // X
+            wrapper.passthrough(Types.DOUBLE); // Y
+            wrapper.passthrough(Types.DOUBLE); // Z
+            wrapper.passthrough(Types.FLOAT); // Yaw
+            wrapper.passthrough(Types.FLOAT); // Pitch
+            fixOnGround(wrapper);
+        });
+        protocol.appendServerbound(ServerboundPackets1_20_5.MOVE_PLAYER_ROT, wrapper -> {
+            wrapper.passthrough(Types.FLOAT); // Yaw
+            wrapper.passthrough(Types.FLOAT); // Pitch
+            fixOnGround(wrapper);
+        });
+        protocol.appendServerbound(ServerboundPackets1_20_5.MOVE_PLAYER_STATUS_ONLY, this::fixOnGround);
+    }
+
+    private void fixOnGround(final PacketWrapper wrapper) {
+        final boolean data = wrapper.read(Types.BOOLEAN);
+        wrapper.write(Types.UNSIGNED_BYTE, data ? (short) 1 : 0); // Carries more data now
+    }
+
+    @Override
+    protected void registerRewrites() {
+        filter().mapDataType(Types1_21.ENTITY_DATA_TYPES::byId);
+        registerEntityDataTypeHandler1_20_3(
+            Types1_21.ENTITY_DATA_TYPES.itemType,
+            Types1_21.ENTITY_DATA_TYPES.blockStateType,
+            Types1_21.ENTITY_DATA_TYPES.optionalBlockStateType,
+            Types1_21.ENTITY_DATA_TYPES.particleType,
+            Types1_21.ENTITY_DATA_TYPES.particlesType,
+            Types1_21.ENTITY_DATA_TYPES.componentType,
+            Types1_21.ENTITY_DATA_TYPES.optionalComponentType
+        );
+        registerBlockStateHandler(EntityTypes1_20_5.ABSTRACT_MINECART, 11);
+
+        filter().type(EntityTypes1_20_5.SALMON).removeIndex(17); // Data type
+    }
+
+    @Override
+    public EntityType typeFromId(final int type) {
+        return EntityTypes1_20_5.getTypeFromId(type);
+    }
+}