Map biomes

core/src/main/java/nl/matsv/viabackwards/protocol/protocol1_16_1to1_16_2/data/BackwardsBiomeMappings.java

@@ -0,0 +1,36 @@
+package nl.matsv.viabackwards.protocol.protocol1_16_1to1_16_2.data;
+import nl.matsv.viabackwards.ViaBackwards;
+import us.myles.ViaVersion.api.Via;
+import us.myles.ViaVersion.protocols.protocol1_16_2to1_16_1.data.BiomeMappings;
+import us.myles.viaversion.libs.fastutil.ints.Int2IntMap;
+import us.myles.viaversion.libs.fastutil.ints.Int2IntOpenHashMap;
+
+public class BackwardsBiomeMappings {
+
+    private static final Int2IntMap BIOMES = new Int2IntOpenHashMap();
+    private static final int HIGHEST_VANILLA_BIOME;
+
+    static {
+        int lastBiome = 0;
+        for (Int2IntMap.Entry entry : BiomeMappings.getBiomes().int2IntEntrySet()) {
+            int newBiome = entry.getIntValue();
+            BIOMES.put(newBiome, entry.getIntKey());
+            if (newBiome > lastBiome) {
+                lastBiome = newBiome;
+            }
+        }
+
+        HIGHEST_VANILLA_BIOME = lastBiome;
+    }
+
+    public static int getOldBiomeId(int biomeId) {
+        if (biomeId > HIGHEST_VANILLA_BIOME) {
+            if (!Via.getConfig().isSuppressConversionWarnings()) {
+                ViaBackwards.getPlatform().getLogger().warning("Custom biome id could not be mapped: " + biomeId);
+            }
+            return 0;
+        }
+
+        return BIOMES.getOrDefault(biomeId, biomeId);
+    }
+}

core/src/main/java/nl/matsv/viabackwards/protocol/protocol1_16_1to1_16_2/packets/BlockItemPackets1_16_2.java

@@ -3,6 +3,7 @@ package nl.matsv.viabackwards.protocol.protocol1_16_1to1_16_2.packets;
 import nl.matsv.viabackwards.ViaBackwards;
 import nl.matsv.viabackwards.api.rewriters.TranslatableRewriter;
 import nl.matsv.viabackwards.protocol.protocol1_16_1to1_16_2.Protocol1_16_1To1_16_2;
+import nl.matsv.viabackwards.protocol.protocol1_16_1to1_16_2.data.BackwardsBiomeMappings;
 import nl.matsv.viabackwards.protocol.protocol1_16_1to1_16_2.data.BackwardsMappings;
 import us.myles.ViaVersion.api.minecraft.BlockChangeRecord;
 import us.myles.ViaVersion.api.minecraft.BlockChangeRecord1_8;
@@ -71,7 +72,13 @@ public class BlockItemPackets1_16_2 extends nl.matsv.viabackwards.api.rewriters.
                     Chunk chunk = wrapper.read(new Chunk1_16_2Type(clientWorld));
                     wrapper.write(new Chunk1_16Type(clientWorld), chunk);
 
-                    //TODO handle biome ids
+                    if (chunk.isBiomeData()) {
+                        int[] biomes = chunk.getBiomeData();
+                        for (int i = 0; i < biomes.length; i++) {
+                            int biome = biomes[i];
+                            biomes[i] = BackwardsBiomeMappings.getOldBiomeId(biome);
+                        }
+                    }
 
                     for (int i = 0; i < chunk.getSections().length; i++) {
                         ChunkSection section = chunk.getSections()[i];