refactor: remove fine-grained biome controls and adjust biome handling

Removed the deprecated `doFineGrainedBiomes` option from `TerraMinestomWorldBuilder` and associated classes. Updated biome management to use `IdentityHashMap` and added additional tracking for created biomes. Upgraded Minestom version to `1_21_6-a40d7115d4`.

buildSrc/src/main/kotlin/Versions.kt

@@ -89,6 +89,6 @@ object Versions {
     }
     
     object Minestom {
-        const val minestom = "1_21_6-c3ccee696b"
+        const val minestom = "1_21_6-a40d7115d4"
     }
 }

platforms/minestom/example/src/main/java/com/dfsek/terra/minestom/TerraMinestomExample.java

@@ -44,7 +44,6 @@ public class TerraMinestomExample {
     public void attachTerra() {
         world = platform.worldBuilder(instance)
             .defaultPack()
-            .doFineGrainedBiomes(false)
             .attach();
     }
 

platforms/minestom/src/main/java/com/dfsek/terra/minestom/api/TerraMinestomWorldBuilder.java

@@ -22,7 +22,6 @@ public class TerraMinestomWorldBuilder {
     private EntityFactory entityFactory = new DefaultEntityFactory();
     private BlockEntityFactory blockEntityFactory;
     private BiomeFactory biomeFactory = new MinestomUserDefinedBiomeFactory();
-    private boolean doFineGrainedBiomes = true;
 
     public TerraMinestomWorldBuilder(TerraMinestomPlatform platform, Instance instance) {
         this.platform = platform;
@@ -70,20 +69,7 @@ public class TerraMinestomWorldBuilder {
         return this;
     }
 
-    /**
-     * Due to a current bug with the minestom biome encoder, sometimes, the client gets kicked when decoding a chunk
-     * packet with more than one biome. Until this is fixed in minestom, one can disable fine-grained biomes to prevent
-     * this issue.
-     *
-     * @deprecated Scheduled for removal once Minestom rolls out a fix
-     */
-    @Deprecated
-    public TerraMinestomWorldBuilder doFineGrainedBiomes(boolean doFineGrainedBiomes) {
-        this.doFineGrainedBiomes = doFineGrainedBiomes;
-        return this;
-    }
-
     public TerraMinestomWorld attach() {
-        return new TerraMinestomWorld(platform, instance, pack, seed, entityFactory, blockEntityFactory, biomeFactory, doFineGrainedBiomes);
+        return new TerraMinestomWorld(platform, instance, pack, seed, entityFactory, blockEntityFactory, biomeFactory);
     }
 }

platforms/minestom/src/main/java/com/dfsek/terra/minestom/biome/MinestomUserDefinedBiomePool.java

@@ -1,6 +1,8 @@
 package com.dfsek.terra.minestom.biome;
 
 import java.util.HashMap;
+import java.util.HashSet;
+import java.util.IdentityHashMap;
 
 import com.dfsek.terra.api.config.ConfigPack;
 import com.dfsek.terra.api.world.biome.Biome;
@@ -8,7 +10,8 @@ import com.dfsek.terra.minestom.api.BiomeFactory;
 
 
 public class MinestomUserDefinedBiomePool {
-    private final HashMap<String, UserDefinedBiome> biomes = new HashMap<>();
+    private final IdentityHashMap<Biome, UserDefinedBiome> biomes = new IdentityHashMap<>();
+    private final HashSet<String> createdBiomes = new HashSet<>();
     private final BiomeFactory factory;
     private final ConfigPack configPack;
 
@@ -18,18 +21,21 @@ public class MinestomUserDefinedBiomePool {
     }
 
     public UserDefinedBiome getBiome(Biome source) {
-        UserDefinedBiome userDefinedBiome = biomes.get(source.getID());
+        UserDefinedBiome userDefinedBiome = biomes.get(source);
         if(userDefinedBiome != null) return userDefinedBiome;
         userDefinedBiome = factory.create(configPack, source);
-        biomes.put(source.getID(), userDefinedBiome);
+        biomes.put(source, userDefinedBiome);
+        createdBiomes.add(source.getID());
         return userDefinedBiome;
     }
 
     public void preloadBiomes(Iterable<Biome> biomesToLoad) {
         biomesToLoad
             .forEach(biome -> {
-                if(!this.biomes.containsKey(biome.getID())) {
-                    this.biomes.put(biome.getID(), factory.create(configPack, biome));
+                if(!this.createdBiomes.contains(biome.getID())) {
+                    UserDefinedBiome udf = factory.create(configPack, biome);
+                    this.biomes.put(biome, udf);
+                    this.createdBiomes.add(biome.getID());
                 }
             });
     }

platforms/minestom/src/main/java/com/dfsek/terra/minestom/biome/UserDefinedBiome.java

@@ -1,9 +1,49 @@
 package com.dfsek.terra.minestom.biome;
 
 import net.kyori.adventure.key.Key;
+import net.minestom.server.MinecraftServer;
+import net.minestom.server.registry.DynamicRegistry;
 import net.minestom.server.registry.RegistryKey;
 import net.minestom.server.world.biome.Biome;
 
 
-public record UserDefinedBiome(Key key, RegistryKey<Biome> registry, String id, Biome biome) {
+public class UserDefinedBiome {
+    private static final DynamicRegistry<Biome> BIOME_REGISTRY = MinecraftServer.getBiomeRegistry();
+
+    private final Key key;
+    private final RegistryKey<Biome> registry;
+    private final String id;
+    private final Biome biome;
+
+    private int registryId = -1;
+
+    public UserDefinedBiome(Key key, RegistryKey<Biome> registry, String id, Biome biome) {
+        this.key = key;
+        this.registry = registry;
+        this.id = id;
+        this.biome = biome;
+    }
+
+    public Key key() {
+        return key;
+    }
+
+    public RegistryKey<Biome> registryKey() {
+        return registry;
+    }
+
+    public String id() {
+        return id;
+    }
+
+    public Biome biome() {
+        return biome;
+    }
+
+    public int registryId() {
+        if(registryId == -1) {
+            registryId = BIOME_REGISTRY.getId(registry);
+        }
+        return registryId;
+    }
 }

platforms/minestom/src/main/java/com/dfsek/terra/minestom/world/MinestomChunkGeneratorWrapper.java

@@ -1,9 +1,13 @@
 package com.dfsek.terra.minestom.world;
 
 import net.minestom.server.coordinate.Point;
+import net.minestom.server.instance.block.Block;
 import net.minestom.server.instance.generator.GenerationUnit;
 import net.minestom.server.instance.generator.Generator;
+import net.minestom.server.instance.generator.GeneratorImpl.AreaModifierImpl;
+import net.minestom.server.instance.generator.GeneratorImpl.SectionModifierImpl;
 import net.minestom.server.instance.generator.UnitModifier;
+import net.minestom.server.instance.palette.Palette;
 import org.jetbrains.annotations.NotNull;
 
 import com.dfsek.terra.api.Platform;
@@ -22,25 +26,21 @@ public class MinestomChunkGeneratorWrapper implements Generator, GeneratorWrappe
     private final GeneratedChunkCache cache;
     private final TerraMinestomWorld world;
     private final BiomeProvider biomeProvider;
-    private final boolean doFineGrainedBiomes;
     private final MinestomUserDefinedBiomePool biomePool;
     private ChunkGenerator generator;
     private ConfigPack pack;
 
     public MinestomChunkGeneratorWrapper(
-        Platform platform,
         ChunkGenerator generator,
         TerraMinestomWorld world,
         ConfigPack pack,
-        MinestomUserDefinedBiomePool biomePool,
-        boolean doFineGrainedBiomes
+        MinestomUserDefinedBiomePool biomePool
     ) {
         this.generator = generator;
         this.world = world;
         this.pack = pack;
         this.biomePool = biomePool;
         this.biomeProvider = pack.getBiomeProvider();
-        this.doFineGrainedBiomes = doFineGrainedBiomes;
         this.cache = new GeneratedChunkCache(world.getDimensionType(), generator, world, biomeProvider);
         preloadBiomes();
     }
@@ -49,6 +49,7 @@ public class MinestomChunkGeneratorWrapper implements Generator, GeneratorWrappe
         return generator;
     }
 
+    @SuppressWarnings("UnstableApiUsage")
     @Override
     public void generate(@NotNull GenerationUnit unit) {
         Point start = unit.absoluteStart();
@@ -56,27 +57,33 @@ public class MinestomChunkGeneratorWrapper implements Generator, GeneratorWrappe
         int z = start.chunkZ();
         int blockX = start.blockX();
         int blockZ = start.blockZ();
-        int minY = world.getMinHeight();
-        int maxY = world.getMaxHeight();
         CachedChunk chunk = cache.at(x, z);
         UnitModifier modifier = unit.modifier();
         chunk.writeRelative(modifier);
 
-        if(doFineGrainedBiomes) {
-            for(int y = minY; y < maxY; y++) {
-                for(int absoluteX = blockX; absoluteX < blockX + 16; absoluteX++) {
-                    for(int absoluteZ = blockZ; absoluteZ < blockZ + 16; absoluteZ++) {
-                        UserDefinedBiome userDefinedBiome = biomePool.getBiome(
-                            biomeProvider.getBiome(absoluteX, y, absoluteZ, world.getSeed())
-                        );
-                        modifier.setBiome(absoluteX, y, absoluteZ, userDefinedBiome.registry());
+        AreaModifierImpl areaModifiers = (AreaModifierImpl) modifier;
+        for(GenerationUnit section : areaModifiers.sections()) {
+            SectionModifierImpl sectionModifier = (SectionModifierImpl) section.modifier();
+            Palette biomes = sectionModifier.genSection().biomes();
+            int minY = section.absoluteStart().blockY();
+            for(int relativeX = 0; relativeX < 16; relativeX += 1) {
+                int absoluteX = blockX + relativeX;
+                for(int relativeZ = 0; relativeZ < 16; relativeZ  += 1) {
+                    int absoluteZ = blockZ + relativeZ;
+                    for(int relativeY = 0; relativeY < 16; relativeY  += 1) {
+                        int absoluteY = minY + relativeY;
+
+                        if (relativeX % 4 == 0 && relativeY % 4 == 0 && relativeZ % 4 == 0) {
+                            UserDefinedBiome userDefinedBiome = biomePool.getBiome(
+                                biomeProvider.getBiome(absoluteX, absoluteY, absoluteZ, world.getSeed())
+                            );
+
+                            int registryId = userDefinedBiome.registryId();
+                            biomes.set(relativeX / 4, relativeY / 4, relativeZ / 4, registryId);
+                        }
                     }
                 }
             }
-        } else {
-            // TODO: remove with feature flag once minestom fixed biome encoding
-            UserDefinedBiome userDefinedBiome = biomePool.getBiome(biomeProvider.getBiome(blockX, 100, blockZ, world.getSeed()));
-            modifier.fillBiome(userDefinedBiome.registry());
         }
 
         unit.fork(setter -> {

platforms/minestom/src/main/java/com/dfsek/terra/minestom/world/TerraMinestomWorld.java

@@ -44,8 +44,7 @@ public final class TerraMinestomWorld implements ServerWorld, WorldProperties {
         long seed,
         EntityFactory entityFactory,
         BlockEntityFactory blockEntityFactory,
-        BiomeFactory factory,
-        boolean doFineGrainedBiomes
+        BiomeFactory factory
     ) {
         this.instance = instance;
         this.pack = pack;
@@ -55,12 +54,10 @@ public final class TerraMinestomWorld implements ServerWorld, WorldProperties {
         this.blockEntityFactory = blockEntityFactory;
 
         this.wrapper = new MinestomChunkGeneratorWrapper(
-            platform,
             pack.getGeneratorProvider().newInstance(pack),
             this,
             pack,
-            new MinestomUserDefinedBiomePool(pack, factory),
-            doFineGrainedBiomes
+            new MinestomUserDefinedBiomePool(pack, factory)
         );
         this.entityFactory = entityFactory;