implement headless for 1.21.4

core/src/main/java/com/volmit/iris/core/commands/CommandDeveloper.java

@@ -140,12 +140,16 @@ public class CommandDeveloper implements DecreeExecutor {
     public void packBenchmark(
             @Param(description = "The pack to bench", aliases = {"pack"}, defaultValue = "overworld")
             IrisDimension dimension,
-            @Param(description = "Radius in regions", defaultValue = "5")
-            int radius,
+            @Param(description = "Diameter in regions", defaultValue = "5")
+            int diameter,
+            @Param(description = "Headless", defaultValue = "true")
+            boolean headless,
             @Param(description = "Open GUI while benchmarking", defaultValue = "false")
             boolean gui
     ) {
-        new IrisPackBenchmarking(dimension, radius, gui);
+        int rb = diameter << 9;
+        Iris.info("Benchmarking pack " + dimension.getName() + " with diameter: " + rb + "(" + diameter + ")");
+        new IrisPackBenchmarking(dimension, diameter, headless, gui);
     }
 
     @Decree(description = "Upgrade to another Minecraft version")

core/src/main/java/com/volmit/iris/core/nms/IHeadless.java

@@ -0,0 +1,22 @@
+package com.volmit.iris.core.nms;
+
+import com.volmit.iris.core.pregenerator.PregenListener;
+import com.volmit.iris.util.documentation.ChunkCoordinates;
+import com.volmit.iris.util.documentation.RegionCoordinates;
+import com.volmit.iris.util.parallel.MultiBurst;
+
+import java.io.Closeable;
+import java.util.concurrent.CompletableFuture;
+
+public interface IHeadless extends Closeable {
+    int getLoadedChunks();
+
+    @ChunkCoordinates
+    boolean exists(int x, int z);
+
+    @RegionCoordinates
+    CompletableFuture<Void> generateRegion(MultiBurst burst, int x, int z, int maxConcurrent, PregenListener listener);
+
+    @ChunkCoordinates
+    void generateChunk(int x, int z);
+}

core/src/main/java/com/volmit/iris/core/nms/INMSBinding.java

@@ -30,15 +30,12 @@ import com.volmit.iris.util.nbt.mca.palette.MCAPaletteAccess;
 import com.volmit.iris.util.nbt.tag.CompoundTag;
 import org.bukkit.*;
 import org.bukkit.block.Biome;
-import org.bukkit.entity.Dolphin;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.EntityType;
 import org.bukkit.event.entity.CreatureSpawnEvent;
 import org.bukkit.generator.ChunkGenerator;
-import org.bukkit.generator.structure.Structure;
 import org.bukkit.inventory.ItemStack;
 
-import java.awt.*;
 import java.awt.Color;
 
 public interface INMSBinding {
@@ -124,5 +121,9 @@ public interface INMSBinding {
         return 441;
     }
 
+    default IHeadless createHeadless(Engine engine) {
+        return null;
+    }
+
     KList<String> getStructureKeys();
 }

core/src/main/java/com/volmit/iris/core/pregenerator/methods/HeadlessPregenMethod.java

@@ -0,0 +1,109 @@
+/*
+ *  Iris is a World Generator for Minecraft Bukkit Servers
+ *  Copyright (c) 2024 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.volmit.iris.core.pregenerator.methods;
+
+import com.volmit.iris.Iris;
+import com.volmit.iris.core.IrisSettings;
+import com.volmit.iris.core.nms.IHeadless;
+import com.volmit.iris.core.nms.INMS;
+import com.volmit.iris.core.pregenerator.PregenListener;
+import com.volmit.iris.core.pregenerator.PregeneratorMethod;
+import com.volmit.iris.engine.framework.Engine;
+import com.volmit.iris.util.mantle.Mantle;
+import com.volmit.iris.util.parallel.MultiBurst;
+
+import java.io.IOException;
+import java.util.concurrent.Semaphore;
+
+public class HeadlessPregenMethod implements PregeneratorMethod {
+    private final Engine engine;
+    private final IHeadless headless;
+    private final Semaphore semaphore;
+    private final int max;
+    private final MultiBurst burst;
+
+    public HeadlessPregenMethod(Engine engine) {
+        this.max = IrisSettings.getThreadCount(IrisSettings.get().getConcurrency().getParallelism());
+        this.engine = engine;
+        this.headless = INMS.get().createHeadless(engine);
+        burst = new MultiBurst("HeadlessPregen", 8);
+        this.semaphore = new Semaphore(max);
+    }
+
+    @Override
+    public void init() {
+    }
+
+    @Override
+    public void close() {
+        try {
+            semaphore.acquire(max);
+        } catch (InterruptedException ignored) {
+        }
+        try {
+            headless.close();
+        } catch (IOException e) {
+            Iris.error("Failed to close headless");
+            e.printStackTrace();
+        }
+        burst.close();
+    }
+
+    @Override
+    public void save() {
+    }
+
+    @Override
+    public boolean supportsRegions(int x, int z, PregenListener listener) {
+        return false;
+    }
+
+    @Override
+    public String getMethod(int x, int z) {
+        return "Headless";
+    }
+
+    @Override
+    public void generateRegion(int x, int z, PregenListener listener) {
+    }
+
+    @Override
+    public void generateChunk(int x, int z, PregenListener listener) {
+        try {
+            semaphore.acquire();
+        } catch (InterruptedException ignored) {
+            return;
+        }
+
+        burst.complete(() -> {
+            try {
+                listener.onChunkGenerating(x, z);
+                headless.generateChunk(x, z);
+                listener.onChunkGenerated(x, z);
+            } finally {
+                semaphore.release();
+            }
+        });
+    }
+
+    @Override
+    public Mantle getMantle() {
+        return engine.getMantle().getMantle();
+    }
+}

core/src/main/java/com/volmit/iris/core/tools/IrisPackBenchmarking.java

@@ -2,9 +2,17 @@ package com.volmit.iris.core.tools;
 
 
 import com.volmit.iris.Iris;
+import com.volmit.iris.core.IrisSettings;
+import com.volmit.iris.core.loader.IrisData;
 import com.volmit.iris.core.pregenerator.PregenTask;
+import com.volmit.iris.core.pregenerator.methods.HeadlessPregenMethod;
+import com.volmit.iris.core.pregenerator.methods.HybridPregenMethod;
+import com.volmit.iris.core.service.StudioSVC;
+import com.volmit.iris.engine.IrisEngine;
 import com.volmit.iris.engine.framework.Engine;
+import com.volmit.iris.engine.framework.EngineTarget;
 import com.volmit.iris.engine.object.IrisDimension;
+import com.volmit.iris.engine.object.IrisWorld;
 import com.volmit.iris.util.collection.KList;
 import com.volmit.iris.util.collection.KMap;
 import com.volmit.iris.util.exceptions.IrisException;
@@ -33,13 +41,16 @@ public class IrisPackBenchmarking {
     public static boolean benchmarkInProgress = false;
     private final PrecisionStopwatch stopwatch = new PrecisionStopwatch();
     private final IrisDimension dimension;
-    private final int radius;
+    private final int diameter;
     private final boolean gui;
+    private final boolean headless;
+    private transient Engine engine;
 
-    public IrisPackBenchmarking(IrisDimension dimension, int radius, boolean gui) {
+    public IrisPackBenchmarking(IrisDimension dimension, int diameter, boolean headless, boolean gui) {
         instance = this;
         this.dimension = dimension;
-        this.radius = radius;
+        this.diameter = diameter;
+        this.headless = headless;
         this.gui = gui;
         runBenchmark();
     }
@@ -55,7 +66,7 @@ public class IrisPackBenchmarking {
                         deleteDirectory(file.toPath());
                     }
                     createBenchmark();
-                    while (!IrisToolbelt.isIrisWorld(Bukkit.getWorld("benchmark"))) {
+                    while (!headless && !IrisToolbelt.isIrisWorld(Bukkit.getWorld("benchmark"))) {
                         J.sleep(1000);
                         Iris.debug("Iris PackBenchmark: Waiting...");
                     }
@@ -73,7 +84,6 @@ public class IrisPackBenchmarking {
     public void finishedBenchmark(KList<Integer> cps) {
         try {
             String time = Form.duration(stopwatch.getMillis());
-            Engine engine = IrisToolbelt.access(Bukkit.getWorld("benchmark")).getEngine();
             Iris.info("-----------------");
             Iris.info("Results:");
             Iris.info("- Total time: " + time);
@@ -114,12 +124,16 @@ public class IrisPackBenchmarking {
                 e.printStackTrace();
             }
 
-            J.s(() -> {
-                var world = Bukkit.getWorld("benchmark");
-                if (world == null) return;
-                IrisToolbelt.evacuate(world);
-                Bukkit.unloadWorld(world, true);
-            });
+            if (headless) {
+                engine.close();
+            } else {
+                J.s(() -> {
+                    var world = Bukkit.getWorld("benchmark");
+                    if (world == null) return;
+                    IrisToolbelt.evacuate(world);
+                    Bukkit.unloadWorld(world, true);
+                });
+            }
 
             stopwatch.end();
         } catch (Exception e) {
@@ -130,13 +144,34 @@ public class IrisPackBenchmarking {
 
     private void createBenchmark() {
         try {
-            IrisToolbelt.createWorld()
+            if (headless) {
+                Iris.info("Using headless benchmark!");
+                IrisWorld world = IrisWorld.builder()
+                        .name("benchmark")
+                        .minHeight(dimension.getMinHeight())
+                        .maxHeight(dimension.getMaxHeight())
+                        .seed(1337)
+                        .worldFolder(new File(Bukkit.getWorldContainer(), "benchmark"))
+                        .environment(dimension.getEnvironment())
+                        .build();
+                Iris.service(StudioSVC.class).installIntoWorld(
+                        Iris.getSender(),
+                        dimension.getLoadKey(),
+                        world.worldFolder());
+                var data = IrisData.get(new File(world.worldFolder(), "iris/pack"));
+                var dim = data.getDimensionLoader().load(dimension.getLoadKey());
+                engine = new IrisEngine(new EngineTarget(world, dim, data), false);
+                return;
+            }
+
+            engine = IrisToolbelt.access(IrisToolbelt.createWorld()
                     .dimension(dimension.getLoadKey())
                     .name("benchmark")
                     .seed(1337)
                     .studio(false)
                     .benchmark(true)
-                    .create();
+                    .create())
+                    .getEngine();
         } catch (IrisException e) {
             throw new RuntimeException(e);
         }
@@ -146,9 +181,15 @@ public class IrisPackBenchmarking {
         IrisToolbelt.pregenerate(PregenTask
                 .builder()
                 .gui(gui)
-                .width(radius)
-                .height(radius)
-                .build(), Bukkit.getWorld("benchmark")
+                .width(diameter)
+                .height(diameter)
+                .build(), headless ?
+                new HeadlessPregenMethod(engine) :
+                new HybridPregenMethod(
+                        engine.getWorld().realWorld(),
+                        IrisSettings.getThreadCount(IrisSettings.get().getConcurrency().getParallelism())
+                ),
+                engine
         );
     }
 

core/src/main/java/com/volmit/iris/engine/IrisEngine.java

@@ -304,6 +304,11 @@ public class IrisEngine implements Engine {
         return generated.get();
     }
 
+    @Override
+    public void addGenerated(int x, int z) {
+        generated.incrementAndGet();
+    }
+
     @Override
     public double getGeneratedPerSecond() {
         if (perSecondLatch.flip()) {

core/src/main/java/com/volmit/iris/engine/framework/Engine.java

@@ -612,6 +612,9 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
 
     int getGenerated();
 
+    @ChunkCoordinates
+    void addGenerated(int x, int z);
+
     CompletableFuture<Long> getHash32();
 
     default <T> IrisPosition lookForStreamResult(T find, ProceduralStream<T> stream, Function2<T, T, Boolean> matcher, long timeout) {

core/src/main/java/com/volmit/iris/engine/object/IrisWorld.java

@@ -19,6 +19,7 @@
 package com.volmit.iris.engine.object;
 
 import com.volmit.iris.Iris;
+import com.volmit.iris.core.nms.IHeadless;
 import com.volmit.iris.core.tools.IrisToolbelt;
 import com.volmit.iris.util.collection.KList;
 import lombok.*;
@@ -48,6 +49,7 @@ public class IrisWorld {
     private long seed;
     private World.Environment environment;
     private World realWorld;
+    private IHeadless headless;
     private int minHeight;
     private int maxHeight;
 

core/src/main/java/com/volmit/iris/util/hunk/view/SyncChunkDataHunkHolder.java

@@ -0,0 +1,48 @@
+package com.volmit.iris.util.hunk.view;
+
+import com.volmit.iris.Iris;
+import com.volmit.iris.util.hunk.storage.ArrayHunk;
+import org.bukkit.Material;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.generator.ChunkGenerator;
+
+public class SyncChunkDataHunkHolder extends ArrayHunk<BlockData> {
+    private static final BlockData AIR = Material.AIR.createBlockData();
+    private final ChunkGenerator.ChunkData chunk;
+    private final Thread mainThread = Thread.currentThread();
+
+    public SyncChunkDataHunkHolder(ChunkGenerator.ChunkData chunk) {
+        super(16, chunk.getMaxHeight() - chunk.getMinHeight(), 16);
+        this.chunk = chunk;
+    }
+
+    @Override
+    public void setRaw(int x, int y, int z, BlockData data) {
+        if (Thread.currentThread() != mainThread)
+            Iris.warn("SyncChunkDataHunkHolder is not on the main thread");
+        super.setRaw(x, y, z, data);
+    }
+
+    @Override
+    public BlockData getRaw(int x, int y, int z) {
+        if (Thread.currentThread() != mainThread)
+            Iris.warn("SyncChunkDataHunkHolder is not on the main thread");
+        BlockData b = super.getRaw(x, y, z);
+
+        return b != null ? b : AIR;
+    }
+
+    public void apply() {
+        for (int i = getHeight()-1; i >= 0; i--) {
+            for (int j = 0; j < getWidth(); j++) {
+                for (int k = 0; k < getDepth(); k++) {
+                    BlockData b = super.getRaw(j, i, k);
+
+                    if (b != null) {
+                        chunk.setBlock(j, i + chunk.getMinHeight(), k, b);
+                    }
+                }
+            }
+        }
+    }
+}

nms/v1_21_R3/src/main/java/com/volmit/iris/core/nms/v1_21_R3/NMSBinding.java

@@ -2,9 +2,11 @@ package com.volmit.iris.core.nms.v1_21_R3;
 
 import com.mojang.brigadier.exceptions.CommandSyntaxException;
 import com.volmit.iris.Iris;
+import com.volmit.iris.core.nms.IHeadless;
 import com.volmit.iris.core.nms.INMSBinding;
 import com.volmit.iris.core.nms.container.BiomeColor;
 import com.volmit.iris.core.nms.datapack.DataVersion;
+import com.volmit.iris.core.nms.v1_21_R3.headless.Headless;
 import com.volmit.iris.engine.data.cache.AtomicCache;
 import com.volmit.iris.engine.framework.Engine;
 import com.volmit.iris.util.collection.KList;
@@ -643,4 +645,9 @@ public class NMSBinding implements INMSBinding {
 
         return keys;
     }
+
+    @Override
+    public IHeadless createHeadless(Engine engine) {
+        return new Headless(engine);
+    }
 }

nms/v1_21_R3/src/main/java/com/volmit/iris/core/nms/v1_21_R3/headless/DirectTerrainChunk.java

@@ -0,0 +1,194 @@
+package com.volmit.iris.core.nms.v1_21_R3.headless;
+
+import com.volmit.iris.Iris;
+import com.volmit.iris.core.nms.BiomeBaseInjector;
+import com.volmit.iris.engine.data.chunk.TerrainChunk;
+import com.volmit.iris.util.data.IrisBlockData;
+import lombok.Data;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.EntityBlock;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import org.bukkit.Material;
+import org.bukkit.block.Biome;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.craftbukkit.v1_21_R3.block.CraftBiome;
+import org.bukkit.craftbukkit.v1_21_R3.block.CraftBlockType;
+import org.bukkit.craftbukkit.v1_21_R3.block.data.CraftBlockData;
+import org.bukkit.craftbukkit.v1_21_R3.util.CraftMagicNumbers;
+import org.bukkit.generator.ChunkGenerator;
+import org.bukkit.material.MaterialData;
+import org.jetbrains.annotations.NotNull;
+
+@Data
+public final class DirectTerrainChunk implements TerrainChunk {
+    private final ChunkAccess access;
+    private final int minHeight, maxHeight;
+
+    public DirectTerrainChunk(ChunkAccess access) {
+        this.access = access;
+        this.minHeight = access.getMinY();
+        this.maxHeight = access.getMaxY();
+    }
+
+    @Override
+    public BiomeBaseInjector getBiomeBaseInjector() {
+        return null;
+    }
+
+    @NotNull
+    @Override
+    public Biome getBiome(int x, int z) {
+        return getBiome(x, 0, z);
+    }
+
+    @NotNull
+    @Override
+    public Biome getBiome(int x, int y, int z) {
+        if (y < minHeight || y > maxHeight) return Biome.PLAINS;
+        return CraftBiome.minecraftHolderToBukkit(access.getNoiseBiome(x >> 2, y >> 2, z >> 2));
+    }
+
+    @Override
+    public void setBiome(int x, int z, Biome bio) {
+        for (int y = minHeight; y < maxHeight; y += 4) {
+            setBiome(x, y, z, bio);
+        }
+    }
+
+    @Override
+    public void setBiome(int x, int y, int z, Biome bio) {
+        if (y < minHeight || y > maxHeight) return;
+        access.setBiome(x & 15, y, z & 15, CraftBiome.bukkitToMinecraftHolder(bio));
+    }
+
+    public void setBlock(int x, int y, int z, Material material) {
+        this.setBlock(x, y, z, material.createBlockData());
+    }
+
+    public void setBlock(int x, int y, int z, MaterialData material) {
+        this.setBlock(x, y, z, CraftMagicNumbers.getBlock(material));
+    }
+
+    @Override
+    public void setBlock(int x, int y, int z, BlockData blockData) {
+        if (blockData == null) {
+            Iris.error("NULL BD");
+        }
+        if (blockData instanceof IrisBlockData data)
+            blockData = data.getBase();
+        if (!(blockData instanceof CraftBlockData craftBlockData))
+            throw new IllegalArgumentException("Expected CraftBlockData, got " + blockData.getClass().getSimpleName() + " instead");
+        access.setBlockState(new BlockPos(x & 15, y, z & 15), craftBlockData.getState(), false);
+    }
+
+    public void setRegion(int xMin, int yMin, int zMin, int xMax, int yMax, int zMax, Material material) {
+        this.setRegion(xMin, yMin, zMin, xMax, yMax, zMax, material.createBlockData());
+    }
+
+    public void setRegion(int xMin, int yMin, int zMin, int xMax, int yMax, int zMax, MaterialData material) {
+        this.setRegion(xMin, yMin, zMin, xMax, yMax, zMax, CraftMagicNumbers.getBlock(material));
+    }
+
+    public void setRegion(int xMin, int yMin, int zMin, int xMax, int yMax, int zMax, BlockData blockData) {
+        this.setRegion(xMin, yMin, zMin, xMax, yMax, zMax, ((CraftBlockData) blockData).getState());
+    }
+
+    public Material getType(int x, int y, int z) {
+        return CraftBlockType.minecraftToBukkit(this.getTypeId(x, y, z).getBlock());
+    }
+
+    public MaterialData getTypeAndData(int x, int y, int z) {
+        return CraftMagicNumbers.getMaterial(this.getTypeId(x, y, z));
+    }
+
+    public BlockData getBlockData(int x, int y, int z) {
+        return CraftBlockData.fromData(this.getTypeId(x, y, z));
+    }
+
+    @Override
+    public ChunkGenerator.ChunkData getRaw() {
+        return null;
+    }
+
+    @Override
+    public void setRaw(ChunkGenerator.ChunkData data) {
+
+    }
+
+    @Override
+    public void inject(ChunkGenerator.BiomeGrid biome) {
+
+    }
+
+    public void setRegion(int xMin, int yMin, int zMin, int xMax, int yMax, int zMax, BlockState type) {
+        if (xMin > 15 || yMin >= this.maxHeight || zMin > 15)
+            return;
+
+        if (xMin < 0) {
+            xMin = 0;
+        }
+
+        if (yMin < this.minHeight) {
+            yMin = this.minHeight;
+        }
+
+        if (zMin < 0) {
+            zMin = 0;
+        }
+
+        if (xMax > 16) {
+            xMax = 16;
+        }
+
+        if (yMax > this.maxHeight) {
+            yMax = this.maxHeight;
+        }
+
+        if (zMax > 16) {
+            zMax = 16;
+        }
+
+        if (xMin >= xMax || yMin >= yMax || zMin >= zMax)
+            return;
+
+        for (int y = yMin; y < yMax; ++y) {
+            for (int x = xMin; x < xMax; ++x) {
+                for (int z = zMin; z < zMax; ++z) {
+                    this.setBlock(x, y, z, type);
+                }
+            }
+        }
+
+    }
+
+    public BlockState getTypeId(int x, int y, int z) {
+        if (x != (x & 15) || y < this.minHeight || y >= this.maxHeight || z != (z & 15))
+            return Blocks.AIR.defaultBlockState();
+        return access.getBlockState(new BlockPos(access.getPos().getMinBlockX() + x, y, access.getPos().getMinBlockZ() + z));
+    }
+
+    public byte getData(int x, int y, int z) {
+        return CraftMagicNumbers.toLegacyData(this.getTypeId(x, y, z));
+    }
+
+    private void setBlock(int x, int y, int z, BlockState type) {
+        if (x != (x & 15) || y < this.minHeight || y >= this.maxHeight || z != (z & 15))
+            return;
+        BlockPos blockPosition = new BlockPos(access.getPos().getMinBlockX() + x, y, access.getPos().getMinBlockZ() + z);
+        BlockState oldBlockData = access.setBlockState(blockPosition, type, false);
+        if (type.hasBlockEntity()) {
+            BlockEntity tileEntity = ((EntityBlock) type.getBlock()).newBlockEntity(blockPosition, type);
+            if (tileEntity == null) {
+                access.removeBlockEntity(blockPosition);
+            } else {
+                access.setBlockEntity(tileEntity);
+            }
+        } else if (oldBlockData != null && oldBlockData.hasBlockEntity()) {
+            access.removeBlockEntity(blockPosition);
+        }
+
+    }
+}

nms/v1_21_R3/src/main/java/com/volmit/iris/core/nms/v1_21_R3/headless/Headless.java

@@ -0,0 +1,453 @@
+/*
+ *  Iris is a World Generator for Minecraft Bukkit Servers
+ *  Copyright (c) 2024 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.volmit.iris.core.nms.v1_21_R3.headless;
+
+import com.volmit.iris.Iris;
+import com.volmit.iris.core.nms.IHeadless;
+import com.volmit.iris.core.pregenerator.PregenListener;
+import com.volmit.iris.engine.data.cache.AtomicCache;
+import com.volmit.iris.engine.data.cache.Cache;
+import com.volmit.iris.engine.framework.Engine;
+import com.volmit.iris.engine.framework.EngineStage;
+import com.volmit.iris.engine.framework.WrongEngineBroException;
+import com.volmit.iris.engine.object.IrisBiome;
+import com.volmit.iris.util.collection.KList;
+import com.volmit.iris.util.collection.KMap;
+import com.volmit.iris.util.context.ChunkContext;
+import com.volmit.iris.util.context.IrisContext;
+import com.volmit.iris.util.documentation.BlockCoordinates;
+import com.volmit.iris.util.documentation.RegionCoordinates;
+import com.volmit.iris.util.hunk.Hunk;
+import com.volmit.iris.util.hunk.view.BiomeGridHunkHolder;
+import com.volmit.iris.util.hunk.view.SyncChunkDataHunkHolder;
+import com.volmit.iris.util.mantle.MantleFlag;
+import com.volmit.iris.util.math.M;
+import com.volmit.iris.util.math.RNG;
+import com.volmit.iris.util.parallel.MultiBurst;
+import com.volmit.iris.util.scheduling.J;
+import com.volmit.iris.util.scheduling.Looper;
+import com.volmit.iris.util.scheduling.PrecisionStopwatch;
+import it.unimi.dsi.fastutil.shorts.ShortArrayList;
+import it.unimi.dsi.fastutil.shorts.ShortList;
+import lombok.Getter;
+import net.minecraft.Optionull;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Holder;
+import net.minecraft.core.RegistryAccess;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtIo;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.LevelHeightAccessor;
+import net.minecraft.world.level.biome.Biome;
+import net.minecraft.world.level.chunk.*;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.chunk.storage.RegionFile;
+import net.minecraft.world.level.chunk.storage.SerializableChunkData;
+import net.minecraft.world.level.levelgen.Heightmap;
+import net.minecraft.world.level.levelgen.blending.BlendingData;
+import org.bukkit.Bukkit;
+import org.bukkit.Material;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.craftbukkit.v1_21_R3.CraftServer;
+import org.bukkit.craftbukkit.v1_21_R3.block.CraftBiome;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+public class Headless implements IHeadless, LevelHeightAccessor {
+    private static final AtomicCache<RegistryAccess> CACHE = new AtomicCache<>();
+    private final long KEEP_ALIVE = TimeUnit.SECONDS.toMillis(10L);
+    private final Engine engine;
+    private final RegionFileStorage storage;
+    private final ExecutorService executor = Executors.newCachedThreadPool();
+    private final KMap<Long, Region> regions = new KMap<>();
+    private final AtomicInteger loadedChunks = new AtomicInteger();
+    private final KMap<String, Holder<Biome>> customBiomes = new KMap<>();
+    private final KMap<org.bukkit.block.Biome, Holder<Biome>> minecraftBiomes;
+    private final RNG biomeRng;
+    private final @Getter int minY;
+    private final @Getter int height;
+    private transient CompletingThread regionThread;
+    private transient boolean closed = false;
+
+    public Headless(Engine engine) {
+        this.engine = engine;
+        this.storage = new RegionFileStorage(engine.getWorld().worldFolder());
+        this.biomeRng = new RNG(engine.getSeedManager().getBiome());
+        this.minY = engine.getDimension().getMinHeight();
+        this.height = engine.getDimension().getMaxHeight() - minY;
+        engine.getWorld().headless(this);
+
+        AtomicInteger failed = new AtomicInteger();
+        var dimKey = engine.getDimension().getLoadKey();
+        for (var biome : engine.getAllBiomes()) {
+            if (!biome.isCustom()) continue;
+            for (var custom : biome.getCustomDerivitives()) {
+                biomeHolder(dimKey, custom.getId()).ifPresentOrElse(holder -> customBiomes.put(custom.getId(), holder), () -> {
+                    Iris.error("Failed to load custom biome " + dimKey + " " + custom.getId());
+                    failed.incrementAndGet();
+                });
+            }
+        }
+        if (failed.get() > 0) {
+            throw new IllegalStateException("Failed to load " + failed.get() + " custom biomes");
+        }
+
+        minecraftBiomes = new KMap<>(org.bukkit.Registry.BIOME.stream()
+                .collect(Collectors.toMap(Function.identity(), CraftBiome::bukkitToMinecraftHolder)));
+        minecraftBiomes.values().removeAll(customBiomes.values());
+        startRegionCleaner();
+    }
+
+    private void startRegionCleaner() {
+        var cleaner = new Looper() {
+            @Override
+            protected long loop() {
+                if (closed) return -1;
+                long time = M.ms() - KEEP_ALIVE;
+                regions.values()
+                        .stream()
+                        .filter(r -> r.lastEntry < time)
+                        .forEach(Region::submit);
+                return closed ? -1 : 1000;
+            }
+        };
+        cleaner.setName("Iris Region Cleaner - " + engine.getWorld().name());
+        cleaner.setPriority(Thread.MIN_PRIORITY);
+        cleaner.start();
+    }
+
+    @Override
+    public int getLoadedChunks() {
+        return loadedChunks.get();
+    }
+
+    /**
+     * Checks if the mca plate is fully generated or not.
+     *
+     * @param x coord of the chunk
+     * @param z coord of the chunk
+     * @return true if the chunk exists in .mca
+     */
+    @Override
+    public boolean exists(int x, int z) {
+        if (closed) return false;
+        if (engine.getWorld().hasRealWorld() && engine.getWorld().realWorld().isChunkLoaded(x, z))
+            return true;
+        try {
+            CompoundTag tag = storage.read(new ChunkPos(x, z));
+            return tag != null && !"empty".equals(tag.getString("Status"));
+        } catch (IOException e) {
+            return false;
+        }
+    }
+
+    @Override
+    public synchronized CompletableFuture<Void> generateRegion(MultiBurst burst, int x, int z, int maxConcurrent, PregenListener listener) {
+        if (closed) return CompletableFuture.completedFuture(null);
+        if (regionThread != null && !regionThread.future.isDone())
+            throw new IllegalStateException("Region generation already in progress");
+
+        regionThread = new CompletingThread(() -> {
+            boolean listening = listener != null;
+            Semaphore semaphore = new Semaphore(maxConcurrent);
+            CountDownLatch latch = new CountDownLatch(1024);
+
+            iterateRegion(x, z, pos -> {
+                try {
+                    semaphore.acquire();
+                } catch (InterruptedException e) {
+                    semaphore.release();
+                    return;
+                }
+
+                burst.complete(() -> {
+                    try {
+                        if (listening) listener.onChunkGenerating(pos.x, pos.z);
+                        generateChunk(pos.x, pos.z);
+                        if (listening) listener.onChunkGenerated(pos.x, pos.z);
+                    } finally {
+                        semaphore.release();
+                        latch.countDown();
+                    }
+                });
+            });
+            try {
+                latch.await();
+            } catch (InterruptedException ignored) {}
+            if (listening) listener.onRegionGenerated(x, z);
+        }, "Region Generator - " + x + "," + z, Thread.MAX_PRIORITY);
+
+        return regionThread.future;
+    }
+
+    @RegionCoordinates
+    private static void iterateRegion(int x, int z, Consumer<ChunkPos> chunkPos) {
+        int cX = x << 5;
+        int cZ = z << 5;
+        for (int xx = 0; xx < 32; xx++) {
+            for (int zz = 0; zz < 32; zz++) {
+                chunkPos.accept(new ChunkPos(cX + xx, cZ + zz));
+            }
+        }
+    }
+
+    @Override
+    public void generateChunk(int x, int z) {
+        if (closed || exists(x, z)) return;
+        try {
+            var pos = new ChunkPos(x, z);
+            ProtoChunk chunk = newProtoChunk(pos);
+            var tc = new DirectTerrainChunk(chunk);
+            loadedChunks.incrementAndGet();
+
+            SyncChunkDataHunkHolder blocks = new SyncChunkDataHunkHolder(tc);
+            BiomeGridHunkHolder biomes = new BiomeGridHunkHolder(tc, tc.getMinHeight(), tc.getMaxHeight());
+            ChunkContext ctx = generate(engine, pos.x << 4, pos.z << 4, blocks, biomes);
+            blocks.apply();
+            biomes.apply();
+
+            chunk.fillBiomesFromNoise((qX, qY, qZ, sampler) -> getNoiseBiome(engine, ctx, qX << 2, qY << 2, qZ << 2), null);
+            chunk.setPersistedStatus(ChunkStatus.FULL);
+
+            long key = Cache.key(pos.getRegionX(), pos.getRegionZ());
+            regions.computeIfAbsent(key, Region::new)
+                    .add(chunk);
+        } catch (Throwable e) {
+            loadedChunks.decrementAndGet();
+            Iris.error("Failed to generate " + x + ", " + z);
+            e.printStackTrace();
+        }
+    }
+
+    @BlockCoordinates
+    private ChunkContext generate(Engine engine, int x, int z, Hunk<BlockData> vblocks, Hunk<org.bukkit.block.Biome> vbiomes) throws WrongEngineBroException {
+        if (engine.isClosed()) {
+            throw new WrongEngineBroException();
+        }
+
+        engine.getContext().touch();
+        engine.getEngineData().getStatistics().generatedChunk();
+        ChunkContext ctx = null;
+        try {
+            PrecisionStopwatch p = PrecisionStopwatch.start();
+            Hunk<BlockData> blocks = vblocks.listen((xx, y, zz, t) -> engine.catchBlockUpdates(x + xx, y + engine.getMinHeight(), z + zz, t));
+
+            var dimension = engine.getDimension();
+            if (dimension.isDebugChunkCrossSections() && ((x >> 4) % dimension.getDebugCrossSectionsMod() == 0 || (z >> 4) % dimension.getDebugCrossSectionsMod() == 0)) {
+                for (int i = 0; i < 16; i++) {
+                    for (int j = 0; j < 16; j++) {
+                        blocks.set(i, 0, j, Material.CRYING_OBSIDIAN.createBlockData());
+                    }
+                }
+            } else {
+                ctx = new ChunkContext(x, z, engine.getComplex());
+                IrisContext.getOr(engine).setChunkContext(ctx);
+
+                for (EngineStage i : engine.getMode().getStages()) {
+                    i.generate(x, z, blocks, vbiomes, false, ctx);
+                }
+            }
+
+            engine.getMantle().getMantle().flag(x >> 4, z >> 4, MantleFlag.REAL, true);
+            engine.getMetrics().getTotal().put(p.getMilliseconds());
+            engine.addGenerated(x,z);
+        } catch (Throwable e) {
+            Iris.reportError(e);
+            engine.fail("Failed to generate " + x + ", " + z, e);
+        }
+        return ctx;
+    }
+
+    private Holder<Biome> getNoiseBiome(Engine engine, ChunkContext ctx, int x, int y, int z) {
+        int m = y - engine.getMinHeight();
+        IrisBiome ib = ctx == null ? engine.getSurfaceBiome(x, z) : ctx.getBiome().get(x & 15, z & 15);
+        if (ib.isCustom()) {
+            return customBiomes.get(ib.getCustomBiome(biomeRng, x, m, z).getId());
+        } else {
+            return minecraftBiomes.get(ib.getSkyBiome(biomeRng, x, m, z));
+        }
+    }
+
+    @Override
+    public void close() throws IOException {
+        if (closed) return;
+        try {
+            if (regionThread != null) {
+                regionThread.future.join();
+                regionThread = null;
+            }
+
+            regions.values().forEach(Region::submit);
+            Iris.info("Waiting for " + loadedChunks.get() + " chunks to unload...");
+            while (loadedChunks.get() > 0 || !regions.isEmpty())
+                J.sleep(1);
+            Iris.info("All chunks unloaded");
+            executor.shutdown();
+            storage.close();
+            engine.getWorld().headless(null);
+        } finally {
+            closed = true;
+            customBiomes.clear();
+            minecraftBiomes.clear();
+        }
+    }
+
+    private class Region implements Runnable {
+        private final int x, z;
+        private final long key;
+        private final KList<ProtoChunk> chunks = new KList<>(1024);
+        private final AtomicBoolean full = new AtomicBoolean();
+        private long lastEntry = M.ms();
+
+        public Region(long key) {
+            this.x = Cache.keyX(key);
+            this.z = Cache.keyZ(key);
+            this.key = key;
+        }
+
+        @Override
+        public void run() {
+            RegionFile regionFile;
+            try {
+                regionFile = storage.getRegionFile(new ChunkPos(x, z), false);
+            } catch (IOException e) {
+                Iris.error("Failed to load region file " + x + ", " + z);
+                Iris.reportError(e);
+                return;
+            }
+            if (regionFile == null) {
+                Iris.error("Failed to load region file " + x + ", " + z);
+                return;
+            }
+
+            for (var chunk : chunks) {
+                try (DataOutputStream dos = regionFile.getChunkDataOutputStream(chunk.getPos())) {
+                    NbtIo.write(write(chunk), dos);
+                } catch (Throwable e) {
+                    Iris.error("Failed to save chunk " + chunk.getPos().x + ", " + chunk.getPos().z);
+                    e.printStackTrace();
+                }
+                loadedChunks.decrementAndGet();
+            }
+            regions.remove(key);
+        }
+
+        public synchronized void add(ProtoChunk chunk) {
+            chunks.add(chunk);
+            lastEntry = M.ms();
+            if (chunks.size() < 1024)
+                return;
+            submit();
+        }
+
+        public void submit() {
+            if (full.getAndSet(true)) return;
+            executor.submit(this);
+        }
+    }
+
+    private CompoundTag write(ProtoChunk chunk) {
+        RegistryAccess access = registryAccess();
+        List<SerializableChunkData.SectionData> list = new ArrayList<>();
+        LevelChunkSection[] sections = chunk.getSections();
+
+        int minLightSection = getMinSectionY() - 1;
+        int maxLightSection = minLightSection + getSectionsCount() + 2;
+        for(int y = minLightSection; y < maxLightSection; ++y) {
+            int index = chunk.getSectionIndexFromSectionY(y);
+            if (index < 0 || index >= sections.length) continue;
+            LevelChunkSection section = sections[index].copy();
+            list.add(new SerializableChunkData.SectionData(y, section, null, null));
+        }
+
+        List<CompoundTag> blockEntities = new ArrayList<>(chunk.getBlockEntitiesPos().size());
+
+        for(BlockPos blockPos : chunk.getBlockEntitiesPos()) {
+            CompoundTag nbt = chunk.getBlockEntityNbtForSaving(blockPos, access);
+            if (nbt != null) {
+                blockEntities.add(nbt);
+            }
+        }
+        Map<Heightmap.Types, long[]> heightMap = new EnumMap<>(Heightmap.Types.class);
+        for(Map.Entry<Heightmap.Types, Heightmap> entry : chunk.getHeightmaps()) {
+            if (chunk.getPersistedStatus().heightmapsAfter().contains(entry.getKey())) {
+                heightMap.put(entry.getKey(), entry.getValue().getRawData().clone());
+            }
+        }
+
+        ChunkAccess.PackedTicks packedTicks = chunk.getTicksForSerialization(0);
+        ShortList[] postProcessing = Arrays.stream(chunk.getPostProcessing()).map((shortlist) -> shortlist != null ? new ShortArrayList(shortlist) : null).toArray(ShortList[]::new);
+        CompoundTag structureData = new CompoundTag();
+        structureData.put("starts", new CompoundTag());
+        structureData.put("References", new CompoundTag());
+
+        CompoundTag persistentDataContainer = null;
+        if (!chunk.persistentDataContainer.isEmpty()) {
+            persistentDataContainer = chunk.persistentDataContainer.toTagCompound();
+        }
+
+        return new SerializableChunkData(access.lookupOrThrow(Registries.BIOME), chunk.getPos(),
+                chunk.getMinSectionY(), 0, chunk.getInhabitedTime(), chunk.getPersistedStatus(),
+                Optionull.map(chunk.getBlendingData(), BlendingData::pack), chunk.getBelowZeroRetrogen(),
+                chunk.getUpgradeData().copy(), null, heightMap, packedTicks, postProcessing,
+                chunk.isLightCorrect(), list, new ArrayList<>(), blockEntities, structureData, persistentDataContainer)
+                .write();
+    }
+
+    private ProtoChunk newProtoChunk(ChunkPos pos) {
+        return new ProtoChunk(pos, UpgradeData.EMPTY, this, registryAccess().lookupOrThrow(Registries.BIOME), null);
+    }
+
+    private static class CompletingThread extends Thread {
+        private final CompletableFuture<Void> future = new CompletableFuture<>();
+
+        private CompletingThread(Runnable task, String name, int priority) {
+            super(task, name);
+            setPriority(priority);
+            start();
+        }
+
+        @Override
+        public void run() {
+            try {
+                super.run();
+            } finally {
+                future.complete(null);
+            }
+        }
+    }
+
+    private static RegistryAccess registryAccess() {
+        return CACHE.aquire(() -> ((CraftServer) Bukkit.getServer()).getServer().registryAccess());
+    }
+
+    private static Optional<Holder.Reference<Biome>> biomeHolder(String namespace, String path) {
+        return registryAccess().lookupOrThrow(Registries.BIOME).get(ResourceLocation.fromNamespaceAndPath(namespace, path));
+    }
+}

nms/v1_21_R3/src/main/java/com/volmit/iris/core/nms/v1_21_R3/headless/RegionFileStorage.java

@@ -0,0 +1,83 @@
+package com.volmit.iris.core.nms.v1_21_R3.headless;
+
+import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
+import net.minecraft.FileUtil;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtIo;
+import net.minecraft.util.ExceptionCollector;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.chunk.storage.RegionFile;
+import net.minecraft.world.level.chunk.storage.RegionStorageInfo;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.DataInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class RegionFileStorage implements AutoCloseable {
+    private static final RegionStorageInfo info = new RegionStorageInfo("headless", Level.OVERWORLD, "headless");
+    private final Long2ObjectLinkedOpenHashMap<RegionFile> regionCache = new Long2ObjectLinkedOpenHashMap<>();
+    private final Path folder;
+
+    public RegionFileStorage(File folder) {
+        this.folder = new File(folder, "region").toPath();
+    }
+
+    public RegionFile getRegionFile(ChunkPos chunkPos, boolean existingOnly) throws IOException {
+        long id = ChunkPos.asLong(chunkPos.getRegionX(), chunkPos.getRegionZ());
+        RegionFile regionFile;
+        synchronized (this.regionCache) {
+            regionFile = this.regionCache.getAndMoveToFirst(id);
+        }
+        if (regionFile != null) {
+            return regionFile;
+        } else {
+            if (this.regionCache.size() >= 256) {
+                synchronized (this.regionCache) {
+                    this.regionCache.removeLast().close();
+                }
+            }
+
+            FileUtil.createDirectoriesSafe(this.folder);
+            Path path = folder.resolve("r." + chunkPos.getRegionX() + "." + chunkPos.getRegionZ() + ".mca");
+            if (existingOnly && !Files.exists(path)) {
+                return null;
+            } else {
+                regionFile = new RegionFile(info, path, this.folder, true);
+                synchronized (this.regionCache) {
+                    this.regionCache.putAndMoveToFirst(id, regionFile);
+                }
+                return regionFile;
+            }
+        }
+    }
+
+    @Nullable
+    public CompoundTag read(ChunkPos chunkPos) throws IOException {
+        RegionFile regionFile = this.getRegionFile(chunkPos, true);
+        if (regionFile == null) return null;
+
+        try (DataInputStream din = regionFile.getChunkDataInputStream(chunkPos)) {
+            if (din == null) return null;
+            return NbtIo.read(din);
+        }
+    }
+
+    @Override
+    public void close() throws IOException {
+        ExceptionCollector<IOException> collector = new ExceptionCollector<>();
+
+        for (RegionFile regionFile : this.regionCache.values()) {
+            try {
+                regionFile.close();
+            } catch (IOException e) {
+                collector.add(e);
+            }
+        }
+
+        collector.throwIfPresent();
+    }
+}