Add initial stage of chunk builder

build.gradle

@@ -73,4 +73,8 @@ publishing {
 		// The repositories here will be used for publishing your artifact, not for
 		// retrieving dependencies.
 	}
+}
+
+loom {
+	accessWidenerPath = file("src/main/resources/flat-minecraft.accesswidener")
 }

src/main/java/com/cyao/FlatCarverContext.java

@@ -0,0 +1,47 @@
+package com.cyao;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.registry.DynamicRegistryManager;
+import net.minecraft.registry.entry.RegistryEntry;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.HeightLimitView;
+import net.minecraft.world.biome.Biome;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.gen.HeightContext;
+import net.minecraft.world.gen.chunk.ChunkNoiseSampler;
+import net.minecraft.world.gen.noise.NoiseConfig;
+import net.minecraft.world.gen.surfacebuilder.MaterialRules;
+
+import java.util.Optional;
+import java.util.function.Function;
+
+public class FlatCarverContext extends HeightContext {
+    private final DynamicRegistryManager registryManager;
+    private final ChunkNoiseSampler chunkNoiseSampler;
+    private final NoiseConfig noiseConfig;
+    private final MaterialRules.MaterialRule materialRule;
+
+    public FlatCarverContext(PaperChunkGenerator noiseChunkGenerator, DynamicRegistryManager registryManager, HeightLimitView heightLimitView, ChunkNoiseSampler chunkNoiseSampler, NoiseConfig noiseConfig, MaterialRules.MaterialRule materialRule) {
+        super(noiseChunkGenerator, heightLimitView);
+        this.registryManager = registryManager;
+        this.chunkNoiseSampler = chunkNoiseSampler;
+        this.noiseConfig = noiseConfig;
+        this.materialRule = materialRule;
+    }
+
+    /** @deprecated */
+    @Deprecated
+    public Optional<BlockState> applyMaterialRule(Function<BlockPos, RegistryEntry<Biome>> posToBiome, Chunk chunk, BlockPos pos, boolean hasFluid) {
+        return this.noiseConfig.getSurfaceBuilder().applyMaterialRule(this.materialRule, this, posToBiome, chunk, this.chunkNoiseSampler, pos, hasFluid);
+    }
+
+    /** @deprecated */
+    @Deprecated
+    public DynamicRegistryManager getRegistryManager() {
+        return this.registryManager;
+    }
+
+    public NoiseConfig getNoiseConfig() {
+        return this.noiseConfig;
+    }
+}

src/main/java/com/cyao/FlatMinecraft.java

@@ -1,15 +1,22 @@
 package com.cyao;
 
 import net.fabricmc.api.ModInitializer;
+import net.minecraft.registry.Registry;
+import net.minecraft.util.Identifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static net.minecraft.registry.Registries.CHUNK_GENERATOR;
+
 public class FlatMinecraft implements ModInitializer {
 	public static final String MOD_ID = "flat-minecraft";
 	public static final Logger LOGGER = LoggerFactory.getLogger(MOD_ID);
 
 	@Override
 	public void onInitialize() {
 		LOGGER.info("Initializing mod");
+		Registry.register(CHUNK_GENERATOR,
+                Identifier.of("flat-minecraft:2D-world"),
+				PaperChunkGenerator.CODEC);
 	}
 }