SmoothLit joins the battle

- Not attached to the name
- Add SmoothLitVisual opt in interface, allowing any visuals to
  contribute light sections to the arena
- Remove lightChunks from VisualEmbedding, it has been usurped
- Pass total collected light sections from BEs, Es, and effects to the
  engine interface. It seemed the most proper way to hand off
  information from the impl to the backend
- Add SmoothLitVisualStorage to maintain the set of collected sections,
  though at the moment it is very naive and simply unions everything
  upon request, which is also naively done every frame

common/src/api/java/dev/engine_room/flywheel/api/backend/Engine.java

@@ -9,6 +9,7 @@
 import dev.engine_room.flywheel.api.task.Plan;
 import dev.engine_room.flywheel.api.task.TaskExecutor;
 import dev.engine_room.flywheel.api.visualization.VisualizationContext;
+import it.unimi.dsi.fastutil.longs.LongSet;
 import net.minecraft.client.Camera;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Vec3i;
@@ -68,6 +69,13 @@ public interface Engine {
 	 */
 	void delete();
 
+	/**
+	 * Assign the set of sections that visuals have requested GPU light for.
+	 *
+	 * @param sections The set of sections.
+	 */
+	void lightSections(LongSet sections);
+
 	/**
 	 * A block to be rendered as a crumbling overlay.
 	 * @param progress The progress of the crumbling animation in the range [0, 10).

common/src/api/java/dev/engine_room/flywheel/api/visual/LitVisual.java

@@ -2,6 +2,8 @@
 
 import java.util.function.LongConsumer;
 
+import org.jetbrains.annotations.ApiStatus;
+
 import net.minecraft.core.SectionPos;
 
 /**
@@ -51,6 +53,7 @@ public interface LitVisual extends Visual {
 	 * A notifier object that can be used to indicate to the impl
 	 * that the sections a visual is contained in have changed.
 	 */
+	@ApiStatus.NonExtendable
 	interface Notifier {
 		/**
 		 * Invoke this to indicate to the impl that your visual has moved to a different set of sections.

common/src/api/java/dev/engine_room/flywheel/api/visual/SmoothLitVisual.java

@@ -0,0 +1,24 @@
+package dev.engine_room.flywheel.api.visual;
+
+import org.jetbrains.annotations.ApiStatus;
+
+import it.unimi.dsi.fastutil.longs.LongSet;
+
+public interface SmoothLitVisual extends Visual {
+	/**
+	 * Set the section property object.
+	 *
+	 * <p>This method is only called once, upon visual creation,
+	 *
+	 * @param property The property.
+	 */
+	void setSectionProperty(SectionProperty property);
+
+	@ApiStatus.NonExtendable
+	interface SectionProperty {
+		/**
+		 * Invoke this to indicate to the impl that your visual has moved to a different set of sections.
+		 */
+		void lightSections(LongSet sections);
+	}
+}

common/src/api/java/dev/engine_room/flywheel/api/visualization/VisualEmbedding.java

@@ -4,7 +4,6 @@
 import org.joml.Matrix4fc;
 
 import dev.engine_room.flywheel.api.BackendImplemented;
-import it.unimi.dsi.fastutil.longs.LongSet;
 
 @BackendImplemented
 public interface VisualEmbedding extends VisualizationContext {
@@ -16,8 +15,6 @@ public interface VisualEmbedding extends VisualizationContext {
 	 */
 	void transforms(Matrix4fc pose, Matrix3fc normal);
 
-	void lightChunks(LongSet chunks);
-
 	/**
 	 * Delete this embedding.
 	 *

common/src/backend/java/dev/engine_room/flywheel/backend/engine/EngineImpl.java

@@ -22,6 +22,7 @@
 import dev.engine_room.flywheel.lib.task.Flag;
 import dev.engine_room.flywheel.lib.task.NamedFlag;
 import dev.engine_room.flywheel.lib.task.SyncedPlan;
+import it.unimi.dsi.fastutil.longs.LongSet;
 import net.minecraft.client.Camera;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Vec3i;
@@ -41,7 +42,7 @@ public EngineImpl(LevelAccessor level, DrawManager<? extends AbstractInstancer<?
 		this.drawManager = drawManager;
 		sqrMaxOriginDistance = maxOriginDistance * maxOriginDistance;
 		environmentStorage = new EnvironmentStorage();
-		lightStorage = new LightStorage(level, environmentStorage);
+		lightStorage = new LightStorage(level);
 	}
 
 	@Override
@@ -101,6 +102,11 @@ public void delete() {
 		lightStorage.delete();
 	}
 
+	@Override
+	public void lightSections(LongSet sections) {
+		lightStorage.sections(sections);
+	}
+
 	public <I extends Instance> Instancer<I> instancer(Environment environment, InstanceType<I> type, Model model, RenderStage stage) {
 		return drawManager.getInstancer(environment, type, model, stage);
 	}

common/src/backend/java/dev/engine_room/flywheel/backend/engine/EnvironmentStorage.java

@@ -1,8 +1,6 @@
 package dev.engine_room.flywheel.backend.engine;
 
 import dev.engine_room.flywheel.backend.engine.embed.AbstractEmbeddedEnvironment;
-import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
-import it.unimi.dsi.fastutil.longs.LongSet;
 import it.unimi.dsi.fastutil.objects.ReferenceLinkedOpenHashSet;
 import it.unimi.dsi.fastutil.objects.ReferenceSet;
 import it.unimi.dsi.fastutil.objects.ReferenceSets;
@@ -18,10 +16,4 @@ public void flush() {
 		environments.removeIf(AbstractEmbeddedEnvironment::isDeleted);
 		environments.forEach(AbstractEmbeddedEnvironment::flush);
 	}
-
-	public LongSet allLightSections() {
-		var out = new LongOpenHashSet();
-		environments.forEach(e -> e.addLightSections(out));
-		return out;
-	}
 }

common/src/backend/java/dev/engine_room/flywheel/backend/engine/embed/AbstractEmbeddedEnvironment.java

@@ -15,7 +15,6 @@
 import dev.engine_room.flywheel.backend.compile.ContextShader;
 import dev.engine_room.flywheel.backend.engine.EngineImpl;
 import dev.engine_room.flywheel.backend.gl.shader.GlProgram;
-import it.unimi.dsi.fastutil.longs.LongSet;
 import net.minecraft.core.Vec3i;
 
 public abstract class AbstractEmbeddedEnvironment implements Environment, VisualEmbedding {
@@ -95,10 +94,6 @@ public boolean isDeleted() {
 		return deleted;
 	}
 
-	public void addLightSections(LongSet out) {
-
-	}
-
 	/**
 	 * Called by visuals
 	 */

common/src/backend/java/dev/engine_room/flywheel/backend/engine/embed/LightStorage.java

@@ -2,11 +2,11 @@
 
 import java.util.BitSet;
 
+import org.jetbrains.annotations.Nullable;
 import org.lwjgl.system.MemoryUtil;
 
 import dev.engine_room.flywheel.api.event.RenderContext;
 import dev.engine_room.flywheel.api.task.Plan;
-import dev.engine_room.flywheel.backend.engine.EnvironmentStorage;
 import dev.engine_room.flywheel.backend.engine.indirect.StagingBuffer;
 import dev.engine_room.flywheel.backend.gl.buffer.GlBuffer;
 import dev.engine_room.flywheel.lib.task.SimplePlan;
@@ -40,7 +40,6 @@ public class LightStorage {
 	private static final int INVALID_SECTION = -1;
 
 	private final LevelAccessor level;
-	private final EnvironmentStorage environmentStorage;
 
 	private final Arena arena;
 	private final Long2IntMap section2ArenaIndex = new Long2IntOpenHashMap();
@@ -51,41 +50,49 @@ public class LightStorage {
 	private final BitSet changed = new BitSet();
 	private boolean needsLutRebuild = false;
 
-	public LightStorage(LevelAccessor level, EnvironmentStorage environmentStorage) {
+	@Nullable
+	private LongSet requestedSections;
+
+	public LightStorage(LevelAccessor level) {
 		this.level = level;
-		this.environmentStorage = environmentStorage;
 
 		arena = new Arena(SECTION_SIZE_BYTES, DEFAULT_ARENA_CAPACITY_SECTIONS);
 	}
 
+	public void sections(LongSet sections) {
+		requestedSections = sections;
+	}
+
 	public Plan<RenderContext> createFramePlan() {
 		return SimplePlan.of(() -> {
-			var allLightSections = environmentStorage.allLightSections();
+			if (requestedSections == null) {
+				return;
+			}
 
-			removeUnusedSections(allLightSections);
+			removeUnusedSections(requestedSections);
 
 			var knownSections = section2ArenaIndex.keySet();
 
 			var updatedSections = LightUpdateHolder.get(level)
 					.getUpdatedSections();
 
 			// Only add the new sections.
-			allLightSections.removeAll(knownSections);
+			requestedSections.removeAll(knownSections);
 
 			for (long updatedSection : updatedSections) {
 				for (int x = -1; x <= 1; x++) {
 					for (int y = -1; y <= 1; y++) {
 						for (int z = -1; z <= 1; z++) {
 							long section = SectionPos.offset(updatedSection, x, y, z);
 							if (knownSections.contains(section)) {
-								allLightSections.add(section);
+								requestedSections.add(section);
 							}
 						}
 					}
 				}
 			}
 
-			for (long section : allLightSections) {
+			for (long section : requestedSections) {
 				addSection(section);
 			}
 		});

common/src/backend/java/dev/engine_room/flywheel/backend/engine/embed/NestedEmbeddedEnvironment.java

@@ -5,7 +5,6 @@
 
 import dev.engine_room.flywheel.api.event.RenderStage;
 import dev.engine_room.flywheel.backend.engine.EngineImpl;
-import it.unimi.dsi.fastutil.longs.LongSet;
 
 public class NestedEmbeddedEnvironment extends AbstractEmbeddedEnvironment {
 	private final AbstractEmbeddedEnvironment parent;
@@ -15,11 +14,6 @@ public NestedEmbeddedEnvironment(AbstractEmbeddedEnvironment parent, EngineImpl
 		this.parent = parent;
 	}
 
-	@Override
-	public void lightChunks(LongSet chunks) {
-		// noop
-	}
-
 	@Override
 	public void composeMatrices(Matrix4f pose, Matrix3f normal) {
 		parent.composeMatrices(pose, normal);

common/src/backend/java/dev/engine_room/flywheel/backend/engine/embed/TopLevelEmbeddedEnvironment.java

@@ -5,27 +5,12 @@
 
 import dev.engine_room.flywheel.api.event.RenderStage;
 import dev.engine_room.flywheel.backend.engine.EngineImpl;
-import it.unimi.dsi.fastutil.longs.LongArraySet;
-import it.unimi.dsi.fastutil.longs.LongSet;
 
 public class TopLevelEmbeddedEnvironment extends AbstractEmbeddedEnvironment {
-	private final LongSet lightSections = new LongArraySet();
-
 	public TopLevelEmbeddedEnvironment(EngineImpl engine, RenderStage renderStage) {
 		super(engine, renderStage);
 	}
 
-	@Override
-	public void lightChunks(LongSet chunks) {
-		lightSections.clear();
-		lightSections.addAll(chunks);
-	}
-
-	@Override
-	public void addLightSections(LongSet out) {
-		out.addAll(lightSections);
-	}
-
 	@Override
 	public void composeMatrices(Matrix4f pose, Matrix3f normal) {
 		pose.set(this.pose);

common/src/main/java/dev/engine_room/flywheel/impl/visualization/VisualizationManagerImpl.java

@@ -45,6 +45,7 @@
 import dev.engine_room.flywheel.lib.task.SimplePlan;
 import dev.engine_room.flywheel.lib.util.LevelAttached;
 import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
 import net.minecraft.client.Minecraft;
 import net.minecraft.core.Vec3i;
 import net.minecraft.server.level.BlockDestructionProgress;
@@ -104,6 +105,14 @@ private VisualizationManagerImpl(LevelAccessor level) {
 				.ifTrue(recreate)
 				.ifFalse(update)
 				.plan()
+				.then(SimplePlan.of(() -> {
+					// TODO: Lazily re-evaluate the union'd set
+					var out = new LongOpenHashSet();
+					out.addAll(blockEntities.lightSections());
+					out.addAll(entities.lightSections());
+					out.addAll(effects.lightSections());
+					engine.lightSections(out);
+				}))
 				.then(RaisePlan.raise(frameVisualsFlag))
 				.then(engine.createFramePlan())
 				.then(RaisePlan.raise(frameFlag));

common/src/main/java/dev/engine_room/flywheel/impl/visualization/manager/VisualManagerImpl.java

@@ -10,6 +10,7 @@
 import dev.engine_room.flywheel.impl.visualization.storage.Storage;
 import dev.engine_room.flywheel.impl.visualization.storage.Transaction;
 import dev.engine_room.flywheel.lib.task.SimplePlan;
+import it.unimi.dsi.fastutil.longs.LongSet;
 
 public class VisualManagerImpl<T, S extends Storage<T>> implements VisualManager<T> {
 	private final Queue<Transaction<T>> queue = new ConcurrentLinkedQueue<>();
@@ -74,4 +75,8 @@ public Plan<TickableVisual.Context> tickPlan() {
 		return SimplePlan.<TickableVisual.Context>of(context -> processQueue(1))
 				.then(storage.tickPlan());
 	}
+
+	public LongSet lightSections() {
+		return getStorage().lightSections();
+	}
 }

common/src/main/java/dev/engine_room/flywheel/impl/visualization/storage/SmoothLitVisualStorage.java

@@ -0,0 +1,45 @@
+package dev.engine_room.flywheel.impl.visualization.storage;
+
+import java.util.Map;
+
+import dev.engine_room.flywheel.api.visual.SmoothLitVisual;
+import it.unimi.dsi.fastutil.longs.LongArraySet;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import it.unimi.dsi.fastutil.longs.LongSet;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
+
+public class SmoothLitVisualStorage {
+	private final Map<SmoothLitVisual, SectionProperty> visuals = new Reference2ObjectOpenHashMap<>();
+
+	public LongSet sections() {
+		var out = new LongOpenHashSet();
+		for (SectionProperty value : visuals.values()) {
+			out.addAll(value.sections);
+		}
+		return out;
+	}
+
+	public void remove(SmoothLitVisual smoothLit) {
+		visuals.remove(smoothLit);
+	}
+
+	public void add(SmoothLitVisual smoothLit) {
+		var sections = new SectionProperty();
+		visuals.put(smoothLit, sections);
+		smoothLit.setSectionProperty(sections);
+	}
+
+	public void clear() {
+		visuals.clear();
+	}
+
+	private static final class SectionProperty implements SmoothLitVisual.SectionProperty {
+		private final LongSet sections = new LongArraySet();
+
+		@Override
+		public void lightSections(LongSet sections) {
+			this.sections.clear();
+			this.sections.addAll(sections);
+		}
+	}
+}