Contraptions and engines

- Sort of get the batching engine working for contraptions but this feels wrong
 - TaskEngine gets passed in methods
 - Better naming for TaskEngines
 - Do BufferSource ourselves
 - Change BufferBuilderMixin to allow for injection into BufferBuilder objects

src/main/java/com/jozufozu/flywheel/backend/instancing/AbstractInstancer.java

@@ -115,4 +115,9 @@ public abstract class AbstractInstancer<D extends InstanceData> implements Insta
 
 		return instanceData;
 	}
+
+	@Override
+	public String toString() {
+		return "Instancer[" + modelData + ']';
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/instancing/InstanceManager.java

@@ -32,13 +32,11 @@ public abstract class InstanceManager<T> implements InstancingEngine.OriginShift
 	protected final Map<T, AbstractInstance> instances;
 	protected final Object2ObjectOpenHashMap<T, ITickableInstance> tickableInstances;
 	protected final Object2ObjectOpenHashMap<T, IDynamicInstance> dynamicInstances;
-	private final TaskEngine taskEngine;
 
 	protected int frame;
 	protected int tick;
 
-	public InstanceManager(TaskEngine taskEngine, MaterialManager materialManager) {
-		this.taskEngine = taskEngine;
+	public InstanceManager(MaterialManager materialManager) {
 		this.materialManager = materialManager;
 		this.queuedUpdates = new HashSet<>(64);
 		this.queuedAdditions = new HashSet<>(64);
@@ -78,7 +76,7 @@ public abstract class InstanceManager<T> implements InstancingEngine.OriginShift
 	 *     Queued updates are processed.
 	 * </p>
 	 */
-	public void tick(double cameraX, double cameraY, double cameraZ) {
+	public void tick(TaskEngine taskEngine, double cameraX, double cameraY, double cameraZ) {
 		tick++;
 		processQueuedUpdates();
 
@@ -120,7 +118,7 @@ public abstract class InstanceManager<T> implements InstancingEngine.OriginShift
 		if ((tick % getUpdateDivisor(dX, dY, dZ)) == 0) instance.tick();
 	}
 
-	public void beginFrame(Camera info) {
+	public void beginFrame(TaskEngine taskEngine, Camera info) {
 		frame++;
 		processQueuedAdditions();
 

src/main/java/com/jozufozu/flywheel/backend/instancing/InstanceWorld.java

@@ -16,6 +16,8 @@ import com.jozufozu.flywheel.event.RenderLayerEvent;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.multiplayer.ClientLevel;
 import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.LevelAccessor;
 import net.minecraft.world.level.block.entity.BlockEntity;
 
 /**
@@ -29,11 +31,12 @@ public class InstanceWorld {
 	protected final InstanceManager<Entity> entityInstanceManager;
 	protected final InstanceManager<BlockEntity> tileEntityInstanceManager;
 
-	protected final BatchExecutor taskEngine;
+	protected final ParallelTaskEngine taskEngine;
 
-	public InstanceWorld() {
+	public InstanceWorld(LevelAccessor levelAccessor) {
+		Level world = (Level) levelAccessor;
 
-		this.taskEngine = new BatchExecutor();
+		this.taskEngine = new ParallelTaskEngine("Flywheel " + world.dimension().location());
 		this.taskEngine.startWorkers();
 
 		FlwEngine engine = Backend.getInstance()
@@ -42,19 +45,19 @@ public class InstanceWorld {
 		switch (engine) {
 		case INSTANCING -> {
 			InstancingEngine<WorldProgram> manager = InstancingEngine.builder(Contexts.WORLD)
-					.build(this.taskEngine);
+					.build();
 
-			entityInstanceManager = new EntityInstanceManager(this.taskEngine, manager);
-			tileEntityInstanceManager = new TileInstanceManager(this.taskEngine, manager);
+			entityInstanceManager = new EntityInstanceManager(manager);
+			tileEntityInstanceManager = new TileInstanceManager(manager);
 
 			manager.addListener(entityInstanceManager);
 			manager.addListener(tileEntityInstanceManager);
 			this.engine = manager;
 		}
 		case BATCHING -> {
-			this.engine = new BatchingEngine(this.taskEngine);
-			entityInstanceManager = new EntityInstanceManager(this.taskEngine, this.engine);
-			tileEntityInstanceManager = new TileInstanceManager(this.taskEngine, this.engine);
+			this.engine = new BatchingEngine();
+			entityInstanceManager = new EntityInstanceManager(this.engine);
+			tileEntityInstanceManager = new TileInstanceManager(this.engine);
 		}
 		default -> throw new IllegalArgumentException("Unknown engine type");
 		}
@@ -91,8 +94,8 @@ public class InstanceWorld {
 
 		taskEngine.syncPoint();
 
-		tileEntityInstanceManager.beginFrame(event.getInfo());
-		entityInstanceManager.beginFrame(event.getInfo());
+		tileEntityInstanceManager.beginFrame(taskEngine, event.getInfo());
+		entityInstanceManager.beginFrame(taskEngine, event.getInfo());
 	}
 
 	/**
@@ -107,8 +110,8 @@ public class InstanceWorld {
 
 		if (renderViewEntity == null) return;
 
-		tileEntityInstanceManager.tick(renderViewEntity.getX(), renderViewEntity.getY(), renderViewEntity.getZ());
-		entityInstanceManager.tick(renderViewEntity.getX(), renderViewEntity.getY(), renderViewEntity.getZ());
+		tileEntityInstanceManager.tick(taskEngine, renderViewEntity.getX(), renderViewEntity.getY(), renderViewEntity.getZ());
+		entityInstanceManager.tick(taskEngine, renderViewEntity.getX(), renderViewEntity.getY(), renderViewEntity.getZ());
 	}
 
 	/**
@@ -116,7 +119,10 @@ public class InstanceWorld {
 	 */
 	public void renderLayer(RenderLayerEvent event) {
 		taskEngine.syncPoint();
-		engine.render(event);
+		event.stack.pushPose();
+		event.stack.translate(-event.camX, -event.camY, -event.camZ);
+		engine.render(taskEngine, event);
+		event.stack.popPose();
 	}
 
 	/**

src/main/java/com/jozufozu/flywheel/backend/instancing/InstancedRenderDispatcher.java

@@ -22,7 +22,7 @@ import net.minecraftforge.fml.common.Mod;
 @Mod.EventBusSubscriber(Dist.CLIENT)
 public class InstancedRenderDispatcher {
 
-	private static final WorldAttached<InstanceWorld> instanceWorlds = new WorldAttached<>($ -> new InstanceWorld());
+	private static final WorldAttached<InstanceWorld> instanceWorlds = new WorldAttached<>(InstanceWorld::new);
 
 	/**
 	 * Call this when you want to manually run {@link AbstractInstance#update()}.

src/main/java/com/jozufozu/flywheel/backend/instancing/ParallelTaskEngine.java

@@ -17,7 +17,7 @@ import com.jozufozu.flywheel.backend.instancing.batching.WaitGroup;
 import net.minecraft.util.Mth;
 
 // https://github.com/CaffeineMC/sodium-fabric/blob/5d364ed5ba63f9067fcf72a078ca310bff4db3e9/src/main/java/me/jellysquid/mods/sodium/client/render/chunk/compile/ChunkBuilder.java
-public class BatchExecutor implements TaskEngine {
+public class ParallelTaskEngine implements TaskEngine {
 	private static final Logger LOGGER = LogManager.getLogger("BatchExecutor");
 
 	private final AtomicBoolean running = new AtomicBoolean(false);
@@ -30,7 +30,10 @@ public class BatchExecutor implements TaskEngine {
 
 	private final int threadCount;
 
-	public BatchExecutor() {
+	private final String name;
+
+	public ParallelTaskEngine(String name) {
+		this.name = name;
 		threadCount = getOptimalThreadCount();
 	}
 
@@ -49,7 +52,7 @@ public class BatchExecutor implements TaskEngine {
 
 		for (int i = 0; i < this.threadCount; i++) {
 
-			Thread thread = new Thread(new WorkerRunnable(), "Engine Executor " + i);
+			Thread thread = new Thread(new WorkerRunnable(), name + " " + i);
 			thread.setPriority(Math.max(0, Thread.NORM_PRIORITY - 2));
 			thread.start();
 
@@ -121,9 +124,9 @@ public class BatchExecutor implements TaskEngine {
 		Runnable job = this.jobQueue.pollFirst();
 
 		if (job == null) {
-			synchronized (BatchExecutor.this.jobNotifier) {
+			synchronized (ParallelTaskEngine.this.jobNotifier) {
 				try {
-					BatchExecutor.this.jobNotifier.wait();
+					ParallelTaskEngine.this.jobNotifier.wait();
 				} catch (InterruptedException ignored) {
 				}
 			}
@@ -138,7 +141,7 @@ public class BatchExecutor implements TaskEngine {
 		} catch (Exception e) {
 			Flywheel.log.error(e);
 		} finally {
-			BatchExecutor.this.wg.done();
+			ParallelTaskEngine.this.wg.done();
 		}
 	}
 
@@ -155,19 +158,19 @@ public class BatchExecutor implements TaskEngine {
 	}
 	private class WorkerRunnable implements Runnable {
 
-		private final AtomicBoolean running = BatchExecutor.this.running;
+		private final AtomicBoolean running = ParallelTaskEngine.this.running;
 
 		@Override
 		public void run() {
 			// Run until the chunk builder shuts down
 			while (this.running.get()) {
-				Runnable job = BatchExecutor.this.getNextTask();
+				Runnable job = ParallelTaskEngine.this.getNextTask();
 
 				if (job == null) {
 					continue;
 				}
 
-				BatchExecutor.this.processTask(job);
+				ParallelTaskEngine.this.processTask(job);
 			}
 		}
 

src/main/java/com/jozufozu/flywheel/backend/instancing/RenderDispatcher.java

@@ -3,15 +3,15 @@ package com.jozufozu.flywheel.backend.instancing;
 import com.jozufozu.flywheel.event.RenderLayerEvent;
 
 import net.minecraft.client.Camera;
-import net.minecraft.client.renderer.MultiBufferSource;
 
 public interface RenderDispatcher {
 	/**
 	 * Render every model for every material.
 	 *
-	 * @param event     Context for rendering.
+	 * @param taskEngine
+	 * @param event     	Context for rendering.
 	 */
-	void render(RenderLayerEvent event);
+	void render(TaskEngine taskEngine, RenderLayerEvent event);
 
 	/**
 	 * Maintain the integer origin coordinate to be within a certain distance from the camera in all directions.

src/main/java/com/jozufozu/flywheel/backend/instancing/SerialTaskEngine.java

@@ -2,11 +2,11 @@ package com.jozufozu.flywheel.backend.instancing;
 
 import org.jetbrains.annotations.NotNull;
 
-public class ImmediateExecutor implements TaskEngine {
+public class SerialTaskEngine implements TaskEngine {
 
-	public static final ImmediateExecutor INSTANCE = new ImmediateExecutor();
+	public static final SerialTaskEngine INSTANCE = new SerialTaskEngine();
 
-	private ImmediateExecutor() {
+	private SerialTaskEngine() {
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/backend/instancing/SuperBufferSource.java

@@ -0,0 +1,79 @@
+package com.jozufozu.flywheel.backend.instancing;
+
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.jozufozu.flywheel.backend.model.BufferBuilderHack;
+import com.jozufozu.flywheel.backend.model.DirectVertexConsumer;
+import com.mojang.blaze3d.platform.MemoryTracker;
+import com.mojang.blaze3d.vertex.BufferBuilder;
+import com.mojang.blaze3d.vertex.VertexFormat;
+
+import net.minecraft.client.renderer.RenderType;
+
+public class SuperBufferSource {
+
+	protected final Map<RenderType, DrawBuffer> buffers = new HashMap<>();
+	private final BufferBuilder scratch;
+
+	public SuperBufferSource() {
+		scratch = new BufferBuilder(8);
+
+		((BufferBuilderHack) scratch).freeBuffer();
+	}
+
+	public DirectVertexConsumer getBuffer(RenderType renderType, int vertexCount) {
+		return buffers.computeIfAbsent(renderType, DrawBuffer::new)
+				.begin(vertexCount);
+	}
+
+	public void endBatch() {
+		// TODO: when/if this causes trouble with shaders, try to inject our BufferBuilders
+		//  into the RenderBuffers from context.
+
+		BufferBuilderHack hack = (BufferBuilderHack) scratch;
+
+		for (Map.Entry<RenderType, DrawBuffer> entry : buffers.entrySet()) {
+			DrawBuffer builder = entry.getValue();
+
+			if (builder.expectedVertices > 0) {
+				RenderType type = entry.getKey();
+
+				hack.hackBegin(builder.backingBuffer, type.format(), builder.expectedVertices);
+
+				type.end(scratch, 0, 0, 0);
+
+				builder.expectedVertices = 0;
+			}
+		}
+	}
+
+	private static class DrawBuffer {
+
+		private final RenderType type;
+		private ByteBuffer backingBuffer;
+		private int expectedVertices;
+
+		public DrawBuffer(RenderType type) {
+			this.type = type;
+		}
+
+		public DirectVertexConsumer begin(int vertexCount) {
+			this.expectedVertices = vertexCount;
+
+			VertexFormat format = type.format();
+
+			int byteSize = format.getVertexSize() * vertexCount;
+
+			if (backingBuffer == null) {
+				backingBuffer = MemoryTracker.create(byteSize);
+			} if (byteSize > backingBuffer.capacity()) {
+				backingBuffer = MemoryTracker.resize(backingBuffer, byteSize);
+			}
+
+			return new DirectVertexConsumer(backingBuffer, format, vertexCount);
+		}
+
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/instancing/batching/BatchedMaterialGroup.java

@@ -7,13 +7,11 @@ import com.jozufozu.flywheel.api.InstanceData;
 import com.jozufozu.flywheel.api.MaterialGroup;
 import com.jozufozu.flywheel.api.struct.Batched;
 import com.jozufozu.flywheel.api.struct.StructType;
+import com.jozufozu.flywheel.backend.instancing.SuperBufferSource;
 import com.jozufozu.flywheel.backend.instancing.TaskEngine;
-import com.jozufozu.flywheel.backend.model.DirectBufferBuilder;
 import com.jozufozu.flywheel.backend.model.DirectVertexConsumer;
 import com.mojang.blaze3d.vertex.PoseStack;
-import com.mojang.blaze3d.vertex.VertexConsumer;
 
-import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.client.renderer.RenderType;
 
 public class BatchedMaterialGroup implements MaterialGroup {
@@ -36,17 +34,8 @@ public class BatchedMaterialGroup implements MaterialGroup {
 		}
 	}
 
-	public void render(PoseStack stack, MultiBufferSource source, TaskEngine pool) {
-		VertexConsumer buffer = source.getBuffer(state);
+	public void render(PoseStack stack, SuperBufferSource source, TaskEngine pool) {
 
-		if (buffer instanceof DirectBufferBuilder direct) {
-			renderParallel(stack, pool, direct);
-		} else {
-			renderSerial(stack, buffer);
-		}
-	}
-
-	private void renderParallel(PoseStack stack, TaskEngine pool, DirectBufferBuilder direct) {
 		int vertexCount = 0;
 		for (BatchedMaterial<?> material : materials.values()) {
 			for (CPUInstancer<?> instancer : material.models.values()) {
@@ -55,7 +44,7 @@ public class BatchedMaterialGroup implements MaterialGroup {
 			}
 		}
 
-		DirectVertexConsumer consumer = direct.intoDirectConsumer(vertexCount);
+		DirectVertexConsumer consumer = source.getBuffer(state, vertexCount);
 
 		// avoids rendering garbage, but doesn't fix the issue of some instances not being buffered
 		consumer.memSetZero();
@@ -74,12 +63,6 @@ public class BatchedMaterialGroup implements MaterialGroup {
 		}
 	}
 
-	private void renderSerial(PoseStack stack, VertexConsumer consumer) {
-		for (BatchedMaterial<?> value : materials.values()) {
-			value.setupAndRenderInto(stack, consumer);
-		}
-	}
-
 	public void clear() {
 		materials.values().forEach(BatchedMaterial::clear);
 	}

src/main/java/com/jozufozu/flywheel/backend/instancing/batching/BatchingEngine.java

@@ -6,6 +6,7 @@ import java.util.Map;
 
 import com.jozufozu.flywheel.api.MaterialGroup;
 import com.jozufozu.flywheel.backend.RenderLayer;
+import com.jozufozu.flywheel.backend.instancing.SuperBufferSource;
 import com.jozufozu.flywheel.backend.instancing.TaskEngine;
 import com.jozufozu.flywheel.backend.instancing.Engine;
 import com.jozufozu.flywheel.event.RenderLayerEvent;
@@ -21,19 +22,17 @@ import net.minecraft.client.renderer.RenderType;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Vec3i;
 
-public class BatchingEngine implements Engine, MultiBufferSource {
+public class BatchingEngine implements Engine {
 
-	protected final Map<RenderType, BufferBuilder> buffers = new HashMap<>();
-	protected final Map<RenderLayer, Map<RenderType, BatchedMaterialGroup>> layers;
-	protected final TaskEngine taskEngine;
+	private final Map<RenderLayer, Map<RenderType, BatchedMaterialGroup>> layers;
+	private final SuperBufferSource superBufferSource = new SuperBufferSource();
 
-	public BatchingEngine(TaskEngine taskEngine) {
+	public BatchingEngine() {
 		this.layers = new EnumMap<>(RenderLayer.class);
 		for (RenderLayer value : RenderLayer.values()) {
 			layers.put(value, new HashMap<>());
 		}
 
-		this.taskEngine = taskEngine;
 	}
 
 	@Override
@@ -47,21 +46,15 @@ public class BatchingEngine implements Engine, MultiBufferSource {
 	}
 
 	@Override
-	public void render(RenderLayerEvent event) {
-		PoseStack stack = event.stack;
+	public void render(TaskEngine taskEngine, RenderLayerEvent event) {
 
-		stack.pushPose();
-
-		stack.translate(-event.camX, -event.camY, -event.camZ);
-
-		for (BatchedMaterialGroup group : layers.get(event.getLayer()).values()) {
-			group.render(stack, this, taskEngine);
+		Map<RenderType, BatchedMaterialGroup> groups = layers.get(event.getLayer());
+		for (BatchedMaterialGroup group : groups.values()) {
+			group.render(event.stack, superBufferSource, taskEngine);
 		}
 
 		taskEngine.syncPoint();
 
-		stack.popPose();
-
 		// FIXME: this probably breaks some vanilla stuff but it works much better for flywheel
 		Matrix4f mat = new Matrix4f();
 		mat.setIdentity();
@@ -71,20 +64,7 @@ public class BatchingEngine implements Engine, MultiBufferSource {
 			Lighting.setupLevel(mat);
 		}
 
-		// TODO: when/if this causes trouble with shaders, try to inject our BufferBuilders
-		//  into the RenderBuffers from context.
-		buffers.forEach((type, builder) -> type.end(builder, 0, 0, 0));
-	}
-
-	@Override
-	public VertexConsumer getBuffer(RenderType renderType) {
-		BufferBuilder builder = buffers.computeIfAbsent(renderType, type -> new BufferBuilder(type.bufferSize()));
-
-		if (!builder.building()) {
-			builder.begin(renderType.mode(), renderType.format());
-		}
-
-		return builder;
+		superBufferSource.endBatch();
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/backend/instancing/entity/EntityInstanceManager.java

@@ -3,7 +3,6 @@ package com.jozufozu.flywheel.backend.instancing.entity;
 import com.jozufozu.flywheel.api.MaterialManager;
 import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.backend.instancing.AbstractInstance;
-import com.jozufozu.flywheel.backend.instancing.BatchExecutor;
 import com.jozufozu.flywheel.backend.instancing.InstanceManager;
 import com.jozufozu.flywheel.backend.instancing.InstancedRenderRegistry;
 import com.jozufozu.flywheel.backend.instancing.TaskEngine;
@@ -15,8 +14,8 @@ import net.minecraft.world.level.Level;
 
 public class EntityInstanceManager extends InstanceManager<Entity> {
 
-	public EntityInstanceManager(TaskEngine executor, MaterialManager materialManager) {
-		super(executor, materialManager);
+	public EntityInstanceManager(MaterialManager materialManager) {
+		super(materialManager);
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/InstancingEngine.java

@@ -10,7 +10,6 @@ import javax.annotation.Nullable;
 
 import com.jozufozu.flywheel.api.MaterialGroup;
 import com.jozufozu.flywheel.backend.instancing.TaskEngine;
-import com.jozufozu.flywheel.backend.instancing.ImmediateExecutor;
 import com.jozufozu.flywheel.backend.RenderLayer;
 import com.jozufozu.flywheel.backend.gl.GlVertexArray;
 import com.jozufozu.flywheel.backend.gl.buffer.GlBufferType;
@@ -22,7 +21,6 @@ import com.jozufozu.flywheel.util.WeakHashSet;
 import com.mojang.math.Matrix4f;
 
 import net.minecraft.client.Camera;
-import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.client.renderer.RenderType;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Vec3i;
@@ -35,7 +33,6 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 
 	protected BlockPos originCoordinate = BlockPos.ZERO;
 
-	protected final TaskEngine taskEngine;
 	protected final WorldContext<P> context;
 	protected final GroupFactory<P> groupFactory;
 	protected final boolean ignoreOriginCoordinate;
@@ -45,15 +42,14 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 	private final WeakHashSet<OriginShiftListener> listeners;
 
 	public InstancingEngine(WorldContext<P> context, TaskEngine taskEngine) {
-		this(taskEngine, context, InstancedMaterialGroup::new, false);
+		this(context, InstancedMaterialGroup::new, false);
 	}
 
 	public static <P extends WorldProgram> Builder<P> builder(WorldContext<P> context) {
 		return new Builder<>(context);
 	}
 
-	public InstancingEngine(TaskEngine taskEngine, WorldContext<P> context, GroupFactory<P> groupFactory, boolean ignoreOriginCoordinate) {
-		this.taskEngine = taskEngine;
+	public InstancingEngine(WorldContext<P> context, GroupFactory<P> groupFactory, boolean ignoreOriginCoordinate) {
 		this.context = context;
 		this.ignoreOriginCoordinate = ignoreOriginCoordinate;
 
@@ -82,7 +78,7 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 	 * Render every model for every material.
 	 */
 	@Override
-	public void render(RenderLayerEvent event) {
+	public void render(TaskEngine taskEngine, RenderLayerEvent event) {
 		double camX;
 		double camY;
 		double camZ;
@@ -205,11 +201,7 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 		}
 
 		public InstancingEngine<P> build() {
-			return build(ImmediateExecutor.INSTANCE);
-		}
-
-		public InstancingEngine<P> build(TaskEngine taskEngine) {
-			return new InstancingEngine<>(taskEngine, context, groupFactory, ignoreOriginCoordinate);
+			return new InstancingEngine<>(context, groupFactory, ignoreOriginCoordinate);
 		}
 	}
 }

src/main/java/com/jozufozu/flywheel/backend/instancing/tile/TileInstanceManager.java

@@ -3,7 +3,6 @@ package com.jozufozu.flywheel.backend.instancing.tile;
 import com.jozufozu.flywheel.api.MaterialManager;
 import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.backend.instancing.AbstractInstance;
-import com.jozufozu.flywheel.backend.instancing.BatchExecutor;
 import com.jozufozu.flywheel.backend.instancing.InstanceManager;
 import com.jozufozu.flywheel.backend.instancing.InstancedRenderRegistry;
 import com.jozufozu.flywheel.backend.instancing.TaskEngine;
@@ -15,8 +14,8 @@ import net.minecraft.world.level.block.entity.BlockEntity;
 
 public class TileInstanceManager extends InstanceManager<BlockEntity> {
 
-	public TileInstanceManager(TaskEngine executor, MaterialManager materialManager) {
-		super(executor, materialManager);
+	public TileInstanceManager(MaterialManager materialManager) {
+		super(materialManager);
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/backend/model/BufferBuilderHack.java

@@ -0,0 +1,16 @@
+package com.jozufozu.flywheel.backend.model;
+
+import java.nio.ByteBuffer;
+
+import com.mojang.blaze3d.vertex.BufferBuilder;
+import com.mojang.blaze3d.vertex.VertexFormat;
+
+/**
+ * Duck interface used on {@link BufferBuilder} to provide lower level access to the backing memory.
+ */
+public interface BufferBuilderHack {
+
+	void freeBuffer();
+
+	void hackBegin(ByteBuffer buffer, VertexFormat format, int vertexCount);
+}

src/main/java/com/jozufozu/flywheel/backend/model/DirectBufferBuilder.java

@@ -1,20 +0,0 @@
-package com.jozufozu.flywheel.backend.model;
-
-import com.mojang.blaze3d.vertex.BufferBuilder;
-
-/**
- * Duck interface used on {@link BufferBuilder} to provide lower level access to the backing memory.
- */
-public interface DirectBufferBuilder {
-
-	/**
-	 * Create a DirectVertexConsumer from this BufferBuilder.
-	 *
-	 * <p>
-	 *     After this function returns, the internal state of the BufferBuilder will be as if
-	 *     {@link BufferBuilder#endVertex()} was called vertexCount times. It is up to the callee
-	 *     to actually populate the BufferBuilder with vertices using the returned value.
-	 * </p>
-	 */
-	DirectVertexConsumer intoDirectConsumer(int vertexCount);
-}

src/main/java/com/jozufozu/flywheel/backend/model/DirectVertexConsumer.java

@@ -13,7 +13,7 @@ import com.mojang.blaze3d.vertex.VertexFormatElement;
 /**
  * An unsafe vertex consumer allowing for unchecked writes into a ByteBuffer.
  *
- * @see DirectBufferBuilder
+ * @see BufferBuilderHack
  */
 public class DirectVertexConsumer implements VertexConsumer {
 	public final VertexFormat format;

src/main/java/com/jozufozu/flywheel/core/crumbling/CrumblingInstanceManager.java

@@ -1,7 +1,6 @@
 package com.jozufozu.flywheel.core.crumbling;
 
 import com.jozufozu.flywheel.api.MaterialManager;
-import com.jozufozu.flywheel.backend.instancing.ImmediateExecutor;
 import com.jozufozu.flywheel.backend.instancing.tile.TileInstanceManager;
 
 import net.minecraft.core.BlockPos;
@@ -9,7 +8,7 @@ import net.minecraft.core.BlockPos;
 public class CrumblingInstanceManager extends TileInstanceManager {
 
 	public CrumblingInstanceManager(MaterialManager materialManager) {
-		super(ImmediateExecutor.INSTANCE, materialManager);
+		super(materialManager);
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/core/crumbling/CrumblingRenderer.java

@@ -6,6 +6,7 @@ import java.util.SortedSet;
 
 import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.backend.gl.GlTextureUnit;
+import com.jozufozu.flywheel.backend.instancing.SerialTaskEngine;
 import com.jozufozu.flywheel.backend.instancing.InstanceManager;
 import com.jozufozu.flywheel.backend.instancing.instancing.InstancingEngine;
 import com.jozufozu.flywheel.core.Contexts;
@@ -74,9 +75,9 @@ public class CrumblingRenderer {
 			if (_currentLayer != null) {
 				stage.getValue().forEach(instanceManager::add);
 
-				instanceManager.beginFrame(info);
+				instanceManager.beginFrame(SerialTaskEngine.INSTANCE, info);
 
-				materials.render(event);
+				materials.render(SerialTaskEngine.INSTANCE, event);
 
 				instanceManager.invalidate();
 			}

src/main/java/com/jozufozu/flywheel/mixin/BufferBuilderMixin.java

@@ -5,29 +5,34 @@ import java.nio.ByteBuffer;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import org.lwjgl.system.MemoryUtil;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 
+import com.jozufozu.flywheel.backend.instancing.SuperBufferSource;
 import com.jozufozu.flywheel.backend.model.DirectVertexConsumer;
-import com.jozufozu.flywheel.backend.model.DirectBufferBuilder;
+import com.jozufozu.flywheel.backend.model.BufferBuilderHack;
 import com.mojang.blaze3d.vertex.BufferBuilder;
 import com.mojang.blaze3d.vertex.VertexFormat;
 import com.mojang.blaze3d.vertex.VertexFormatElement;
 
 @Mixin(BufferBuilder.class)
-public abstract class BufferBuilderMixin implements DirectBufferBuilder {
+public abstract class BufferBuilderMixin implements BufferBuilderHack {
 	@Shadow
 	private ByteBuffer buffer;
 
+	@Shadow
+	private boolean building;
+
+	@Shadow
+	public abstract void begin(VertexFormat.Mode p_166780_, VertexFormat p_166781_);
+
+	@Shadow
+	private VertexFormat.Mode mode;
+
 	@Shadow
 	private VertexFormat format;
 
-	@Shadow
-	protected abstract void ensureCapacity(int p_85723_);
-
-	@Shadow
-	private int vertices;
-
 	@Shadow
 	@Nullable
 	private VertexFormatElement currentElement;
@@ -36,24 +41,26 @@ public abstract class BufferBuilderMixin implements DirectBufferBuilder {
 	private int elementIndex;
 
 	@Shadow
-	private int nextElementByte;
+	private int vertices;
 
 	@Override
-	@Nonnull
-	public DirectVertexConsumer intoDirectConsumer(int vertexCount) {
-		int bytes = vertexCount * format.getVertexSize();
-		// ensure we have capacity for one extra vertex, BufferBuilder does this on #endVertex
-		ensureCapacity(bytes + format.getVertexSize());
+	public void freeBuffer() {
+		if (this.buffer != null) {
+			MemoryUtil.memFree(this.buffer);
+			this.buffer = null;
+		}
+	}
 
-		DirectVertexConsumer consumer = new DirectVertexConsumer(this.buffer, this.format, vertexCount);
+	@Override
+	public void hackBegin(@Nonnull ByteBuffer buffer, @Nonnull VertexFormat format, int vertexCount) {
+		this.building = true;
+		this.mode = VertexFormat.Mode.QUADS;
 
-		this.vertices += vertexCount;
-		this.currentElement = format.getElements()
-				.get(0);
+		this.buffer = buffer;
+		this.format = format;
+		this.vertices = vertexCount;
+
+		this.currentElement = this.format.getElements().get(0);
 		this.elementIndex = 0;
-		this.nextElementByte += bytes;
-		this.buffer.position(this.buffer.position() + bytes);
-
-		return consumer;
 	}
 }