From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
Date: Thu, 6 Jan 2022 15:59:06 -0800
Subject: [PATCH] Expose vanilla BiomeProvider from WorldInfo


diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index dff3ce704d44d13a250b9a6ae1ec1768e4a8187a..4eafa147edad4fe66fb419635c320a01186e7fea 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -584,7 +584,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
                 chunkgenerator = worlddimension.generator();
             }
 
-            org.bukkit.generator.WorldInfo worldInfo = new org.bukkit.craftbukkit.generator.CraftWorldInfo(iworlddataserver, worldSession, org.bukkit.World.Environment.getEnvironment(dimension), holder.value());
+            org.bukkit.generator.WorldInfo worldInfo = new org.bukkit.craftbukkit.generator.CraftWorldInfo(iworlddataserver, worldSession, org.bukkit.World.Environment.getEnvironment(dimension), holder.value(), chunkgenerator, this.registryAccess().registryOrThrow(net.minecraft.core.Registry.BIOME_REGISTRY)); // Paper
             if (biomeProvider == null && gen != null) {
                 biomeProvider = gen.getDefaultBiomeProvider(worldInfo);
             }
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index e6163f2eab88fd1d77d5fb4878e2913c25df862c..f4aa3096f8e40ac850caf567a0c14dcba74510ce 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1210,7 +1210,7 @@ public final class CraftServer implements Server {
             chunkgenerator = worlddimension.generator();
         }
 
-        WorldInfo worldInfo = new CraftWorldInfo(worlddata, worldSession, creator.environment(), holder.value());
+        WorldInfo worldInfo = new CraftWorldInfo(worlddata, worldSession, creator.environment(), holder.value(), chunkgenerator, this.getHandle().getServer().registryAccess().registryOrThrow(net.minecraft.core.Registry.BIOME_REGISTRY)); // Paper
         if (biomeProvider == null && generator != null) {
             biomeProvider = generator.getDefaultBiomeProvider(worldInfo);
         }
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index a8c3c76ec3aed40655a0c5335407cb20ecfbc63d..7dcaa657f1488a922c14537a673d6c4bd158411c 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -211,6 +211,31 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
         return this.getHandle().clip(new ClipContext(vec3d, vec3d1, ClipContext.Block.COLLIDER, ClipContext.Fluid.NONE, null)).getType() == HitResult.Type.MISS;
     }
+
+    @Override
+    public BiomeProvider vanillaBiomeProvider() {
+        final net.minecraft.world.level.chunk.ChunkGenerator chunkGenerator;
+        if (this.getHandle().chunkSource.getGenerator() instanceof org.bukkit.craftbukkit.generator.CustomChunkGenerator bukkit) {
+            chunkGenerator = bukkit.delegate;
+        } else {
+            chunkGenerator = this.getHandle().chunkSource.getGenerator();
+        }
+        final net.minecraft.core.Registry<net.minecraft.world.level.biome.Biome> biomeRegistry = this.getHandle().registryAccess().registryOrThrow(net.minecraft.core.Registry.BIOME_REGISTRY);
+        final List<Biome> possibleBiomes = chunkGenerator.getBiomeSource().possibleBiomes().stream()
+            .map(biome -> CraftBlock.biomeBaseToBiome(biomeRegistry, biome))
+            .toList();
+        return new BiomeProvider() {
+            @Override
+            public Biome getBiome(final org.bukkit.generator.WorldInfo worldInfo, final int x, final int y, final int z) {
+                return CraftBlock.biomeBaseToBiome(biomeRegistry, chunkGenerator.getNoiseBiome(x >> 2, y >> 2, z >> 2));
+            }
+
+            @Override
+            public List<Biome> getBiomes(final org.bukkit.generator.WorldInfo worldInfo) {
+                return possibleBiomes;
+            }
+        };
+    }
     // Paper end
 
     private static final Random rand = new Random();
diff --git a/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java b/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java
index aeffb30cd91d4b21850059d33070c537bd5cb25e..3918c24dfb6cda4cff18016cca807c2dbc2a9156 100644
--- a/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/CraftWorldInfo.java
@@ -17,8 +17,17 @@ public class CraftWorldInfo implements WorldInfo {
     private final long seed;
     private final int minHeight;
     private final int maxHeight;
+    // Paper start
+    private final net.minecraft.world.level.chunk.ChunkGenerator vanillaChunkGenerator;
+    private final net.minecraft.core.Registry<net.minecraft.world.level.biome.Biome> biomeRegistry;
 
     public CraftWorldInfo(ServerLevelData worldDataServer, LevelStorageSource.LevelStorageAccess session, World.Environment environment, DimensionType dimensionManager) {
+        this(worldDataServer, session, environment, dimensionManager, null, null);
+    }
+    public CraftWorldInfo(ServerLevelData worldDataServer, LevelStorageSource.LevelStorageAccess session, World.Environment environment, DimensionType dimensionManager, net.minecraft.world.level.chunk.ChunkGenerator chunkGenerator, net.minecraft.core.Registry<net.minecraft.world.level.biome.Biome> biomeRegistry) {
+        this.biomeRegistry = biomeRegistry;
+        this.vanillaChunkGenerator = chunkGenerator;
+        // Paper end
         this.name = worldDataServer.getLevelName();
         this.uuid = WorldUUID.getUUID(session.levelPath.toFile());
         this.environment = environment;
@@ -28,6 +37,10 @@ public class CraftWorldInfo implements WorldInfo {
     }
 
     public CraftWorldInfo(String name, UUID uuid, World.Environment environment, long seed, int minHeight, int maxHeight) {
+        // Paper start
+        this.vanillaChunkGenerator = null;
+        this.biomeRegistry = null;
+        // Paper end
         this.name = name;
         this.uuid = uuid;
         this.environment = environment;
@@ -65,4 +78,24 @@ public class CraftWorldInfo implements WorldInfo {
     public int getMaxHeight() {
         return this.maxHeight;
     }
+
+    // Paper start
+    @Override
+    public org.bukkit.generator.BiomeProvider vanillaBiomeProvider() {
+        final java.util.List<org.bukkit.block.Biome> possibleBiomes = CraftWorldInfo.this.vanillaChunkGenerator.getBiomeSource().possibleBiomes().stream()
+            .map(biome -> org.bukkit.craftbukkit.block.CraftBlock.biomeBaseToBiome(CraftWorldInfo.this.biomeRegistry, biome))
+            .toList();
+        return new org.bukkit.generator.BiomeProvider() {
+            @Override
+            public org.bukkit.block.Biome getBiome(final WorldInfo worldInfo, final int x, final int y, final int z) {
+                return org.bukkit.craftbukkit.block.CraftBlock.biomeBaseToBiome(CraftWorldInfo.this.biomeRegistry, CraftWorldInfo.this.vanillaChunkGenerator.getNoiseBiome(x >> 2, y >> 2, z >> 2));
+            }
+
+            @Override
+            public java.util.List<org.bukkit.block.Biome> getBiomes(final org.bukkit.generator.WorldInfo worldInfo) {
+                return possibleBiomes;
+            }
+        };
+    }
+    // Paper end
 }