Add mapping for CHUNKS_BIOMES in 1.21.5->1.21.4 (#976)

Author: Gerrygames

common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_5to1_21_4/rewriter/BlockItemPacketRewriter1_21_5.java

@@ -42,6 +42,7 @@
 import com.viaversion.viaversion.api.minecraft.blockentity.BlockEntity;
 import com.viaversion.viaversion.api.minecraft.chunks.Chunk;
 import com.viaversion.viaversion.api.minecraft.chunks.Chunk1_18;
+import com.viaversion.viaversion.api.minecraft.chunks.DataPalette;
 import com.viaversion.viaversion.api.minecraft.chunks.Heightmap;
 import com.viaversion.viaversion.api.minecraft.data.StructuredDataContainer;
 import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
@@ -62,6 +63,8 @@
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.chunk.ChunkBiomesType1_19_4;
+import com.viaversion.viaversion.api.type.types.chunk.ChunkBiomesType1_21_5;
 import com.viaversion.viaversion.api.type.types.chunk.ChunkType1_20_2;
 import com.viaversion.viaversion.api.type.types.chunk.ChunkType1_21_5;
 import com.viaversion.viaversion.api.type.types.version.Types1_21_4;
@@ -128,6 +131,19 @@ public void registerPackets() {
             wrapper.write(newChunkType, mappedChunk);
         });
 
+        protocol.registerClientbound(ClientboundPackets1_21_5.CHUNKS_BIOMES, wrapper -> {
+            final EntityTracker tracker = protocol.getEntityRewriter().tracker(wrapper.user());
+            final int globalPaletteBiomeBits = ceilLog2(tracker.biomesSent());
+            final Type<DataPalette[]> biomesType = new ChunkBiomesType1_21_5(tracker.currentWorldSectionHeight(), globalPaletteBiomeBits);
+            final Type<DataPalette[]> newBiomesType = new ChunkBiomesType1_19_4(tracker.currentWorldSectionHeight(), globalPaletteBiomeBits);
+
+            final int size = wrapper.passthrough(Types.VAR_INT);
+            for (int i = 0; i < size; i++) {
+                wrapper.passthrough(Types.CHUNK_POSITION);
+                wrapper.passthroughAndMap(biomesType, newBiomesType);
+            }
+        });
+
         protocol.registerClientbound(ClientboundPackets1_21_5.SET_CURSOR_ITEM, this::passthroughClientboundItem);
         registerSetPlayerInventory(ClientboundPackets1_21_5.SET_PLAYER_INVENTORY);
         registerCooldown1_21_2(ClientboundPackets1_21_5.COOLDOWN);