Update README.md

1.21 update

.github/workflows/build-commit.yml

@@ -20,7 +20,7 @@ jobs:
         uses: actions/setup-java@v2
         with:
           distribution: 'temurin'
-          java-version: 17
+          java-version: 21
       - name: Initialize caches
         uses: actions/cache@v3
         with:
@@ -31,17 +31,17 @@ jobs:
           key: ${{ runner.os }}-build-commit-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties') }}
           restore-keys: |
             ${{ runner.os }}-build-commit-
+      - name: Gradle deez
+        uses: gradle/actions/setup-gradle@v3
       - name: Build artifacts
-        run: ./gradlew clean :spotlessApply build
+        run: ./gradlew build
       - name: Upload artifacts
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: nitori-artifacts-${{ steps.ref.outputs.branch }}
           path: build/libs/*.jar
       - name: Reposilite upload
-        uses: gradle/gradle-build-action@bd5760595778326ba7f1441bcf7e88b49de61a25 # v2.6.0
-        with:
-          arguments: publish
+        run: ./gradlew publish
         env:
           USERNAME: ${{ secrets.ORG_GRADLE_PROJECT_GENSOREPOUSERNAME }}
           TOKEN: ${{ secrets.ORG_GRADLE_PROJECT_GENSOREPOPASSWORD }}

README.md

@@ -1,34 +1,42 @@
 # Nitori
 A performance mod that converts patches into mixins using the Ignite Framework for Paper/Spigot.
 
-## Optimizations
-This plugin provides the following optimizations:
-- [x] Iterate entity trackers faster by using Int2ObjectLinkedOpenHashMap
-- [ ] Reduce constants allocations
-- [x] Entity Micro Optimizations
-- [ ] Lithium mixins
-  - [x] Fast util
-  - [x] HashedReferenceList
-  - [x] CompactSineLUT
-  - [x] Fast retrieval
-  - [x] Cached hashcode
-  - [x] Store gamerules in fastutil hashmap
-  - [ ] Precompute shape arrays
-  - [ ] Collections.attributes
-  - [ ] Collections.entity_by_type 
-  - [ ] Collections.entity_filtering 
-  - [ ] Chunk serialization
-  - [x] Cache iterate outwards
-  - [ ] Block moving block shapes
-  - [ ] Shapes blockstate cache
-  - [x] Lithium gen
-  - [ ] Ai sensor secondary POI
-  - [ ] World tick scheduler
-- [x] Smarter statistics-ticking
-- [ ] Async Pathfinding
-- [ ] Multithreaded Tracker
+> [!CAUTION]
+> Nitori is more or less depraced to use [Leaf](https://github.com/Winds-Studio/Leaf) in it's replacement for performance orianted features.
 
-**NOTE: This mod may or may not alter the default behaviors of some mob AI.**
+## Optimizations:
+This plugin provides the following optimizations:
+- Faster Entity tracker by utilizing **Multiple Cores** this will allow larger servers to have way more entities
+- Async NBT data saving which improves where paper doesn't on world saving
+- Many of Lithium's Optimization patches which includes:
+  - Faster Math
+  - Faster Entity retrieval
+  - Reduced Memory allocations
+  - Improved inlined logics
+  - Improved collections
+  - Pre-Computed Shape arrays
+  - Improved Block Entity tickings
+  - Lithium Chunk Gen
+  - Mob Ai Improvements (soon)
+  - Fast BlockPos
+  - Faster entity related inmterractions (Hand swing, Sprinting particles etc.)
+  - ...and much more
+- Includes some of the patches from Very Many Players (VMP)'s
+  - Improved player tracking logic
+  - Improved TypeFilterableList
+  - If entity velocity is zero it won't send it as packets
+  - Improved Player lookups
+  - Faster VarInts
+- Some patches from Potatoptimize
+  - Way faster math
+  - Faster rotation logic
+  - Many Inlined logics
+
+## Optimizations To-Do:
+- Async Mob Pathfinding
+- Multithreading starlight using ScaleableLux
+- Easier config to toggle optimizations on and off
+- Improving EntityTickList further
 
 ---
 

build-logic/build.gradle.kts

@@ -16,15 +16,15 @@ dependencies {
 }
 
 java {
-  sourceCompatibility = JavaVersion.VERSION_11
-  targetCompatibility = JavaVersion.VERSION_11
+  sourceCompatibility = JavaVersion.VERSION_21
+  targetCompatibility = JavaVersion.VERSION_21
 }
 
 kotlin {
   target {
     compilations.configureEach {
       kotlinOptions {
-        jvmTarget = "11"
+        jvmTarget = "21"
       }
     }
   }

build-logic/src/main/kotlin/mod.base-conventions.gradle.kts

@@ -1,9 +1,8 @@
 plugins {
   `java-library`
 
-  id("com.github.johnrengelman.shadow")
+  id("io.github.goooler.shadow")
   id("io.papermc.paperweight.userdev")
-  id("com.diffplug.spotless")
   id("maven-publish")
 }
 
@@ -11,7 +10,7 @@ plugins {
 val libs = extensions.getByType(org.gradle.accessors.dm.LibrariesForLibs::class)
 
 java {
-  javaTarget(17)
+  javaTarget(21)
   withSourcesJar()
 }
 
@@ -38,49 +37,36 @@ tasks {
   build {
     dependsOn(reobfJar)
   }
-}
 
-spotless {
-  format("misc") {
-    target(project.files("*.gradle.kts", "gradle.properties", "settings.gradle.kts", "gradle/libs.versions.toml"))
 
-    trimTrailingWhitespace()
-    indentWithSpaces(4)
-    endWithNewline()
+  var jarFile = file("build/libs/%s-%s.jar".format(project.name, project.version))
+  var jarArtifact = artifacts.add("default", jarFile) {
+    type = "jar"
+    builtBy("jar")
   }
 
-  java {
-    licenseHeaderFile("LICENSE_header.txt")
-  }
-}
-
-var jarFile = file("build/libs/%s-%s.jar".format(project.name, project.version))
-var jarArtifact = artifacts.add("default", jarFile) {
-  type = "jar"
-  builtBy("jar")
-}
-
-publishing {
-  publications {
-    create<MavenPublication>("mavenJava") {
-      artifact(jarArtifact)
-      group = "plugins"
-    }
-  }
-
-  repositories {
-    maven {
-      name = "gensorepo"
-      credentials {
-        username = project.findProperty("gpr.user") as String? ?: System.getenv("USERNAME")
-        password = project.findProperty("gpr.key") as String? ?: System.getenv("TOKEN")
+  publishing {
+    publications {
+      create<MavenPublication>("mavenJava") {
+        artifact(jarArtifact)
+        group = "plugins"
+      }
+    }
+
+    repositories {
+      maven {
+        name = "gensorepo"
+        credentials {
+          username = project.findProperty("gpr.user") as String? ?: System.getenv("USERNAME")
+          password = project.findProperty("gpr.key") as String? ?: System.getenv("TOKEN")
+        }
+        // url to the releases maven repository
+        url = uri("https://repo.gensokyoreimagined.net/")
       }
-      // url to the releases maven repository
-      url = uri("https://repo.gensokyoreimagined.net/")
     }
   }
-}
 
-tasks.named("publishMavenJavaPublicationToGensorepoRepository") {
-  dependsOn("reobfJar")
-}
+  tasks.named("publishMavenJavaPublicationToGensorepoRepository") {
+    dependsOn("reobfJar")
+  }
+}

gradle.properties

@@ -1,5 +1,5 @@
 group=net.gensokyoreimagined.nitori
-version=1.1-SNAPSHOT
+version=1.5-SNAPSHOT
 description=Converting patches into mixins, for the Ignite Framework
 
 org.gradle.parallel=true

gradle/libs.versions.toml

@@ -6,10 +6,10 @@ jetbrains = "24.1.0"
 ignite = "1.0.1"
 mixin = "0.8.5"
 mixinExtras = "0.3.5"
-paperweight = "1.5.11"
-shadow = "8.1.1"
+paperweight = "1.7.1"
+shadow = "8.1.2"
 spotless = "6.25.0"
-paper = "1.20.4-R0.1-SNAPSHOT"
+paper = "1.21-R0.1-SNAPSHOT"
 
 [libraries]
 jetbrains-annotations = { module = "org.jetbrains:annotations", version.ref = "jetbrains" }
@@ -19,5 +19,5 @@ mixin = { group = "org.spongepowered", name = "mixin", version.ref = "mixin" }
 mixinExtras = { group = "io.github.llamalad7", name = "mixinextras-common", version.ref = "mixinExtras" }
 
 build-paperweight = { module = "io.papermc.paperweight.userdev:io.papermc.paperweight.userdev.gradle.plugin", version.ref = "paperweight" }
-build-shadow = { module = "com.github.johnrengelman:shadow", version.ref = "shadow" }
+build-shadow = { module = "io.github.goooler:shadow", version.ref = "shadow" }
 build-spotless = { module = "com.diffplug.spotless:spotless-plugin-gradle", version.ref = "spotless" }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.9-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

src/main/java/net/gensokyoreimagined/nitori/access/IMixinChunkEntitySlicesAccess.java

@@ -14,9 +14,9 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 package net.gensokyoreimagined.nitori.access;
 
-import com.destroystokyo.paper.util.maplist.EntityList;
-
-public interface IMixinChunkEntitySlicesAccess {
-    @SuppressWarnings("EmptyMethod")
-    EntityList getEntities();
-}
+//import ca.spottedleaf.moonrise.common.list.EntityList;
+//
+//public interface IMixinChunkEntitySlicesAccess {
+//    @SuppressWarnings("EmptyMethod")
+//    EntityList getEntities();
+//}

src/main/java/net/gensokyoreimagined/nitori/access/IMixinIteratorSafeOrderedReferenceSetAccess.java

@@ -14,7 +14,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 package net.gensokyoreimagined.nitori.access;
 
-public interface IMixinIteratorSafeOrderedReferenceSetAccess {
-    @SuppressWarnings("EmptyMethod")
-    int getListSize();
-}
+//public interface IMixinIteratorSafeOrderedReferenceSetAccess {
+//    @SuppressWarnings("EmptyMethod")
+//    int getListSize();
+//}

src/main/java/net/gensokyoreimagined/nitori/access/ITypeFilterableList.java

@@ -0,0 +1,8 @@
+package net.gensokyoreimagined.nitori.access;
+
+public interface ITypeFilterableList {
+
+    Object[] getBackingArray();
+
+
+}

src/main/java/net/gensokyoreimagined/nitori/api/inventory/LithiumInventory.java

@@ -0,0 +1,40 @@
+package net.gensokyoreimagined.nitori.api.inventory;
+
+import net.minecraft.core.NonNullList;
+import net.minecraft.world.entity.vehicle.ContainerEntity;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.level.block.entity.RandomizableContainerBlockEntity;
+
+
+public interface LithiumInventory extends ContainerEntity {
+
+    /**
+     * Getter for the inventory stack list of this inventory.
+     *
+     * @return inventory stack list
+     */
+    NonNullList<ItemStack> getInventoryLithium();
+
+    /**
+     * Setter for the inventory stack list of this inventory.
+     * Used to replace the stack list with Lithium's custom stack list.
+     *
+     * @param inventory inventory stack list
+     */
+    void setInventoryLithium(NonNullList<ItemStack> inventory);
+
+    /**
+     * Generates the loot like a hopper access would do in vanilla.
+     * <p>
+     * If a modded inventory has custom loot generation code, it will be required to override this
+     * loot generation method. Otherwise, its loot may be generated too late.
+     */
+    default void generateLootLithium() {
+        if (this instanceof RandomizableContainerBlockEntity) {
+            ((RandomizableContainerBlockEntity) this).unpackLootTable(null);
+        }
+        if (this instanceof ContainerEntity) {
+            ((ContainerEntity) this).unpackChestVehicleLootTable(null);
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/ai/MemoryModificationCounter.java

@@ -0,0 +1,6 @@
+package net.gensokyoreimagined.nitori.common.ai;
+
+public interface MemoryModificationCounter {
+
+    long lithium$getModCount();
+}

src/main/java/net/gensokyoreimagined/nitori/common/ai/WeightedListIterable.java

@@ -0,0 +1,45 @@
+package net.gensokyoreimagined.nitori.common.ai;
+
+import net.minecraft.world.entity.ai.behavior.ShufflingList;
+
+import java.util.Iterator;
+
+public interface WeightedListIterable<U> extends Iterable<U> {
+    /**
+     * {@inheritDoc}
+     */
+    Iterator<U> iterator();
+
+    /**
+     * Returns an {@link Iterable} over the elements in the {@param list}. This allows code to circumvent the usage
+     * of streams, providing a speed-up in other areas of the game.
+     */
+    @SuppressWarnings("unchecked")
+    static <T> Iterable<? extends T> cast(ShufflingList<T> list) {
+        return ((WeightedListIterable<T>) list);
+    }
+
+    /**
+     * A wrapper type for an iterator over the entries of a {@link ShufflingList} which de-references the contained
+     * values for consumers.
+     *
+     * @param <U> The value type stored in each list entry
+     */
+    class ListIterator<U> implements Iterator<U> {
+        private final Iterator<ShufflingList.WeightedEntry<? extends U>> inner;
+
+        public ListIterator(Iterator<ShufflingList.WeightedEntry<? extends U>> inner) {
+            this.inner = inner;
+        }
+
+        @Override
+        public boolean hasNext() {
+            return this.inner.hasNext();
+        }
+
+        @Override
+        public U next() {
+            return this.inner.next().getData();
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/ai/pathing/BlockStatePathingCache.java

@@ -0,0 +1,8 @@
+package net.gensokyoreimagined.nitori.common.ai.pathing;
+
+import net.minecraft.world.level.pathfinder.PathType;
+
+public interface BlockStatePathingCache {
+    PathType lithium$getPathNodeType();
+    PathType lithium$getNeighborPathNodeType();
+}

src/main/java/net/gensokyoreimagined/nitori/common/ai/pathing/PathNodeCache.java

@@ -0,0 +1,133 @@
+package net.gensokyoreimagined.nitori.common.ai.pathing;
+
+import net.gensokyoreimagined.nitori.common.block.BlockCountingSection;
+import net.gensokyoreimagined.nitori.common.block.BlockStateFlags;
+import net.gensokyoreimagined.nitori.common.util.Pos;
+import net.gensokyoreimagined.nitori.common.world.ChunkView;
+import net.gensokyoreimagined.nitori.common.world.WorldHelper;
+import net.minecraft.world.level.block.state.BlockBehaviour;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.pathfinder.PathfindingContext;
+import net.minecraft.world.level.pathfinder.WalkNodeEvaluator;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.pathfinder.PathType;
+import net.gensokyoreimagined.nitori.mixin.unapplied.ai.pathing.PathContextAccessor;
+
+public abstract class PathNodeCache {
+    private static boolean isChunkSectionDangerousNeighbor(LevelChunkSection section) {
+        return section.getStates().maybeHas(state -> getNeighborPathType(state) != PathType.OPEN);
+    }
+
+    public static PathType getPathType(BlockState state) {
+        return ((BlockStatePathingCache) state).lithium$getPathNodeType();
+    }
+
+    public static PathType getNeighborPathType(BlockBehaviour.BlockStateBase state) {
+        return ((BlockStatePathingCache) state).lithium$getNeighborPathNodeType();
+    }
+
+    /**
+     * Returns whether a chunk section is free of dangers. This makes use of a caching layer to greatly
+     * accelerate neighbor danger checks when path-finding.
+     *
+     * @param section The chunk section to test for dangers
+     * @return True if this neighboring section is free of any dangers, otherwise false if it could
+     * potentially contain dangers
+     */
+    public static boolean isSectionSafeAsNeighbor(LevelChunkSection section) {
+        // Empty sections can never contribute a danger
+        if (section.hasOnlyAir()) {
+            return true;
+        }
+
+        if (BlockStateFlags.ENABLED) {
+            return !((BlockCountingSection) section).lithium$mayContainAny(BlockStateFlags.PATH_NOT_OPEN);
+        }
+        return !isChunkSectionDangerousNeighbor(section);
+    }
+
+
+    public static PathType getNodeTypeFromNeighbors(PathfindingContext context, int x, int y, int z, PathType fallback) {
+        BlockGetter world = context.level();
+
+        LevelChunkSection section = null;
+
+        // Check that all the block's neighbors are within the same chunk column. If so, we can isolate all our block
+        // reads to just one chunk and avoid hits against the server chunk manager.
+        if (world instanceof ChunkView chunkView && WorldHelper.areNeighborsWithinSameChunkSection(x, y, z)) {
+            // If the y-coordinate is within bounds, we can cache the chunk section. Otherwise, the if statement to check
+            // if the cached chunk section was initialized will early-exit.
+            if (!world.isOutsideBuildHeight(y)) {
+                ChunkAccess chunk = chunkView.lithium$getLoadedChunk(Pos.ChunkCoord.fromBlockCoord(x), Pos.ChunkCoord.fromBlockCoord(z));
+
+                // If the chunk is absent, the cached section above will remain null, as there is no chunk section anyway.
+                // An empty chunk or section will never pose any danger sources, which will be caught later.
+                if (chunk != null) {
+                    section = chunk.getSections()[Pos.SectionYIndex.fromBlockCoord(world, y)];
+                }
+            }
+
+            // If we can guarantee that blocks won't be modified while the cache is active, try to see if the chunk
+            // section is empty or contains any dangerous blocks within the palette. If not, we can assume any checks
+            // against this chunk section will always fail, allowing us to fast-exit.
+            if (section == null || PathNodeCache.isSectionSafeAsNeighbor(section)) {
+                return fallback; //TODO side effects of vanilla's path node caching
+            }
+        }
+
+        int xStart = x - 1;
+        int yStart = y - 1;
+        int zStart = z - 1;
+
+        int xEnd = x + 1;
+        int yEnd = y + 1;
+        int zEnd = z + 1;
+
+        // Vanilla iteration order is XYZ
+        for (int adjX = xStart; adjX <= xEnd; adjX++) {
+            for (int adjY = yStart; adjY <= yEnd; adjY++) {
+                for (int adjZ = zStart; adjZ <= zEnd; adjZ++) {
+                    // Skip the vertical column of the origin block
+                    if (adjX == x && adjZ == z) {
+                        continue;
+                    }
+
+                    BlockState state;
+
+                    // If we're not accessing blocks outside a given section, we can greatly accelerate block state
+                    // retrieval by calling upon the cached chunk directly.
+                    if (section != null) {
+                        state = section.getBlockState(adjX & 15, adjY & 15, adjZ & 15);
+                    } else {
+                        BlockPos.MutableBlockPos pos = ((PathContextAccessor) context).getMutablePos().set(adjX, adjY, adjZ);
+                        state = world.getBlockState(pos);
+                    }
+
+                    if (state.isAir()) {
+                        continue;
+                    }
+
+                    PathType neighborType = PathNodeCache.getNeighborPathType(state);
+
+                    if (neighborType == null) { //Here null means that no path node type is cached (uninitialized or dynamic)
+                        //Passing null as previous node type to the method signals to other lithium mixins that we only want the neighbor behavior of this block and not its neighbors
+                        neighborType = WalkNodeEvaluator.checkNeighbourBlocks(context, adjX + 1, adjY + 1, adjZ + 1, null);
+                        //Here null means that the path node type is not changed by the block!
+                        if (neighborType == null) {
+                            neighborType = PathType.OPEN;
+                        }
+                    }
+                    if (neighborType != PathType.OPEN) {
+                        return neighborType;
+                    }
+                }
+            }
+        }
+
+        return fallback;
+    }
+
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/BlockCountingSection.java

@@ -0,0 +1,9 @@
+package net.gensokyoreimagined.nitori.common.block;
+
+import net.minecraft.world.level.block.state.BlockState;
+
+public interface BlockCountingSection {
+    boolean lithium$mayContainAny(TrackedBlockStatePredicate trackedBlockStatePredicate);
+
+    void lithium$trackBlockStateChange(BlockState newState, BlockState oldState);
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/BlockListeningSection.java

@@ -0,0 +1,14 @@
+package net.gensokyoreimagined.nitori.common.block;
+
+//import net.gensokyoreimagined.nitori.common.entity.block_tracking.SectionedBlockChangeTracker;
+//import net.minecraft.core.SectionPos;
+//import net.minecraft.world.level.Level;
+//
+//public interface BlockListeningSection {
+//
+//    void lithium$addToCallback(ListeningBlockStatePredicate blockGroup, SectionedBlockChangeTracker tracker, long sectionPos, Level world);
+//
+//    void lithium$removeFromCallback(ListeningBlockStatePredicate blockGroup, SectionedBlockChangeTracker tracker);
+//
+//    void lithium$invalidateListeningSection(SectionPos sectionPos);
+//}

src/main/java/net/gensokyoreimagined/nitori/common/block/BlockStateCounter.java

@@ -0,0 +1,28 @@
+package net.gensokyoreimagined.nitori.common.block;
+
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.PalettedContainer;
+import net.minecraft.world.level.material.FluidState;
+
+public class BlockStateCounter implements PalettedContainer.CountConsumer<BlockState> {
+    public int nonEmptyBlockCount;
+    public int randomTickableBlockCount;
+    public int nonEmptyFluidCount;
+
+    @Override
+    public void accept(BlockState arg, int i) {
+        FluidState lv = arg.getFluidState();
+        if (!arg.isAir()) {
+            this.nonEmptyBlockCount += i;
+            if (arg.isRandomlyTicking()) {
+                this.randomTickableBlockCount += i;
+            }
+        }
+        if (!lv.isEmpty()) {
+            this.nonEmptyBlockCount += i;
+            if (lv.isRandomlyTicking()) {
+                this.nonEmptyFluidCount += i;
+            }
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/BlockStateFlagHolder.java

@@ -0,0 +1,5 @@
+package net.gensokyoreimagined.nitori.common.block;
+
+public interface BlockStateFlagHolder {
+    int lithium$getAllFlags();
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/BlockStateFlags.java

@@ -0,0 +1,123 @@
+package net.gensokyoreimagined.nitori.common.block;
+
+import it.unimi.dsi.fastutil.objects.Reference2BooleanArrayMap;
+import net.gensokyoreimagined.nitori.common.ai.pathing.BlockStatePathingCache;
+import net.gensokyoreimagined.nitori.common.ai.pathing.PathNodeCache;
+import net.gensokyoreimagined.nitori.common.entity.FluidCachingEntity;
+import net.gensokyoreimagined.nitori.common.reflection.ReflectionUtil;
+import net.minecraft.world.level.block.state.BlockBehaviour;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.tags.FluidTags;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.pathfinder.PathType;
+
+import java.util.ArrayList;
+
+public class BlockStateFlags {
+    public static final boolean ENABLED = BlockCountingSection.class.isAssignableFrom(LevelChunkSection.class);
+
+    public static final int NUM_LISTENING_FLAGS;
+    public static final ListeningBlockStatePredicate[] LISTENING_FLAGS;
+    public static final int LISTENING_MASK_OR;
+
+    //Listening Flag
+    public static final ListeningBlockStatePredicate ANY;
+
+    public static final int NUM_TRACKED_FLAGS;
+    public static final TrackedBlockStatePredicate[] TRACKED_FLAGS;
+
+    //Counting flags
+    public static final TrackedBlockStatePredicate OVERSIZED_SHAPE;
+    public static final TrackedBlockStatePredicate PATH_NOT_OPEN;
+    public static final TrackedBlockStatePredicate WATER;
+    public static final TrackedBlockStatePredicate LAVA;
+
+    public static final TrackedBlockStatePredicate[] FLAGS;
+
+    //Non counting flags
+    public static final TrackedBlockStatePredicate ENTITY_TOUCHABLE;
+
+    static {
+        Reference2BooleanArrayMap<ListeningBlockStatePredicate> listeningFlags = new Reference2BooleanArrayMap<>();
+
+        ANY = new ListeningBlockStatePredicate(listeningFlags.size()) {
+            @Override
+            public boolean test(BlockState operand) {
+                return true;
+            }
+        };
+        //false -> we listen to changes of all blocks that pass the predicate test.
+        //true -> we only listen to changes of the predicate test result
+        listeningFlags.put(ANY, false);
+
+        NUM_LISTENING_FLAGS = listeningFlags.size();
+        int listenMaskOR = 0;
+        int iteration = 0;
+        for (var entry : listeningFlags.reference2BooleanEntrySet()) {
+            boolean listenOnlyXOR = entry.getBooleanValue();
+            listenMaskOR |= listenOnlyXOR ? 0 : 1 << iteration;
+        }
+        LISTENING_MASK_OR = listenMaskOR;
+        LISTENING_FLAGS = listeningFlags.keySet().toArray(new ListeningBlockStatePredicate[NUM_LISTENING_FLAGS]);
+
+
+        ArrayList<TrackedBlockStatePredicate> countingFlags = new ArrayList<>(listeningFlags.keySet());
+
+        OVERSIZED_SHAPE = new TrackedBlockStatePredicate(countingFlags.size()) {
+            @Override
+            public boolean test(BlockState operand) {
+                return operand.hasLargeCollisionShape();
+            }
+        };
+        countingFlags.add(OVERSIZED_SHAPE);
+
+        if (FluidCachingEntity.class.isAssignableFrom(Entity.class)) {
+            WATER = new TrackedBlockStatePredicate(countingFlags.size()) {
+                @Override
+                public boolean test(BlockState operand) {
+                    return operand.getFluidState().getType().is(FluidTags.WATER);
+                }
+            };
+            countingFlags.add(WATER);
+
+            LAVA = new TrackedBlockStatePredicate(countingFlags.size()) {
+                @Override
+                public boolean test(BlockState operand) {
+                    return operand.getFluidState().getType().is(FluidTags.LAVA);
+                }
+            };
+            countingFlags.add(LAVA);
+        } else {
+            WATER = null;
+            LAVA = null;
+        }
+
+        if (BlockStatePathingCache.class.isAssignableFrom(BlockBehaviour.BlockStateBase.class)) {
+            PATH_NOT_OPEN = new TrackedBlockStatePredicate(countingFlags.size()) {
+                @Override
+                public boolean test(BlockState operand) {
+                    return PathNodeCache.getNeighborPathType(operand) != PathType.OPEN;
+                }
+            };
+            countingFlags.add(PATH_NOT_OPEN);
+        } else {
+            PATH_NOT_OPEN = null;
+        }
+
+        NUM_TRACKED_FLAGS = countingFlags.size();
+        TRACKED_FLAGS = countingFlags.toArray(new TrackedBlockStatePredicate[NUM_TRACKED_FLAGS]);
+
+        ArrayList<TrackedBlockStatePredicate> flags = new ArrayList<>(countingFlags);
+
+        ENTITY_TOUCHABLE = new TrackedBlockStatePredicate(countingFlags.size()) {
+            @Override
+            public boolean test(BlockState operand) {
+                return ReflectionUtil.isBlockStateEntityTouchable(operand);
+            }
+        };
+        flags.add(ENTITY_TOUCHABLE);
+
+        FLAGS = flags.toArray(new TrackedBlockStatePredicate[0]);
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/ListeningBlockStatePredicate.java

@@ -0,0 +1,10 @@
+package net.gensokyoreimagined.nitori.common.block;
+
+public abstract class ListeningBlockStatePredicate extends TrackedBlockStatePredicate {
+    public static int LISTENING_MASK;
+
+    protected ListeningBlockStatePredicate(int index) {
+        super(index);
+        LISTENING_MASK |= (1 << this.getIndex());
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/TrackedBlockStatePredicate.java

@@ -0,0 +1,30 @@
+package net.gensokyoreimagined.nitori.common.block;
+
+import net.minecraft.world.level.block.state.BlockState;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Predicate;
+
+public abstract class TrackedBlockStatePredicate implements Predicate<BlockState> {
+    public static final AtomicBoolean FULLY_INITIALIZED;
+
+    static {
+        FULLY_INITIALIZED = new AtomicBoolean(false);
+        if (!BlockStateFlags.ENABLED) { //classload the BlockStateFlags class which initializes the content of ALL_FLAGS
+            System.out.println("Lithium Cached BlockState Flags are disabled!");
+        }
+    }
+
+    private final int index;
+
+    public TrackedBlockStatePredicate(int index) {
+        if (FULLY_INITIALIZED.get()) {
+            throw new IllegalStateException("Lithium Cached BlockState Flags: Cannot register more flags after assuming to be fully initialized.");
+        }
+        this.index = index;
+    }
+
+    public int getIndex() {
+        return this.index;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/entity/SleepUntilTimeBlockEntityTickInvoker.java

@@ -0,0 +1,37 @@
+package net.gensokyoreimagined.nitori.common.block.entity;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.block.entity.BlockEntityType;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.entity.TickingBlockEntity;
+import org.jetbrains.annotations.NotNull;
+
+public record SleepUntilTimeBlockEntityTickInvoker(BlockEntity sleepingBlockEntity, long sleepUntilTickExclusive,
+                                                   TickingBlockEntity delegate) implements TickingBlockEntity {
+
+    @Override
+    public void tick() {
+        //noinspection ConstantConditions
+        long tickTime = this.sleepingBlockEntity.getLevel().getGameTime();
+        if (tickTime >= this.sleepUntilTickExclusive) {
+            ((SleepingBlockEntity) this.sleepingBlockEntity).setTicker(this.delegate);
+            this.delegate.tick();
+        }
+    }
+
+    @Override
+    public boolean isRemoved() {
+        return this.sleepingBlockEntity.isRemoved();
+    }
+
+    @Override
+    public @NotNull BlockPos getPos() {
+        return this.sleepingBlockEntity.getBlockPos();
+    }
+
+    @Override
+    public String getType() {
+        //noinspection ConstantConditions
+        return BlockEntityType.getKey(this.sleepingBlockEntity.getType()).toString();
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/block/entity/SleepingBlockEntity.java

@@ -0,0 +1,80 @@
+package net.gensokyoreimagined.nitori.common.block.entity;
+
+import net.gensokyoreimagined.nitori.mixin.world.block_entity_ticking.sleeping.WrappedBlockEntityTickInvokerAccessor;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.entity.TickingBlockEntity;
+
+public interface SleepingBlockEntity {
+    TickingBlockEntity SLEEPING_BLOCK_ENTITY_TICKER = new TickingBlockEntity() {
+        public void tick() {
+        }
+
+        public boolean isRemoved() {
+            return false;
+        }
+
+        public BlockPos getPos() {
+            return null;
+        }
+
+        public String getType() {
+            return "<lithium_sleeping>";
+        }
+    };
+
+    WrappedBlockEntityTickInvokerAccessor lithium$getTickWrapper();
+
+    void lithium$setTickWrapper(WrappedBlockEntityTickInvokerAccessor tickWrapper);
+
+    TickingBlockEntity lithium$getSleepingTicker();
+
+    void lithium$setSleepingTicker(TickingBlockEntity sleepingTicker);
+
+    default boolean nitori$startSleeping() {
+        if (this.isSleeping()) {
+            return false;
+        }
+
+        WrappedBlockEntityTickInvokerAccessor tickWrapper = this.lithium$getTickWrapper();
+        if (tickWrapper == null) {
+            return false;
+        }
+        this.lithium$setSleepingTicker(tickWrapper.getTicker());
+        tickWrapper.callRebind(SleepingBlockEntity.SLEEPING_BLOCK_ENTITY_TICKER);
+        return true;
+    }
+
+    default void sleepOnlyCurrentTick() {
+        TickingBlockEntity sleepingTicker = this.lithium$getSleepingTicker();
+        WrappedBlockEntityTickInvokerAccessor tickWrapper = this.lithium$getTickWrapper();
+        if (sleepingTicker == null) {
+            sleepingTicker = tickWrapper.getTicker();
+        }
+        Level world = ((BlockEntity) this).getLevel();
+        tickWrapper.callRebind(new SleepUntilTimeBlockEntityTickInvoker((BlockEntity) this, world.getGameTime() + 1, sleepingTicker));
+        this.lithium$setSleepingTicker(null);
+    }
+
+    default void wakeUpNow() {
+        TickingBlockEntity sleepingTicker = this.lithium$getSleepingTicker();
+        if (sleepingTicker == null) {
+            return;
+        }
+        this.setTicker(sleepingTicker);
+        this.lithium$setSleepingTicker(null);
+    }
+
+    default void setTicker(TickingBlockEntity delegate) {
+        WrappedBlockEntityTickInvokerAccessor tickWrapper = this.lithium$getTickWrapper();
+        if (tickWrapper == null) {
+            return;
+        }
+        tickWrapper.callRebind(delegate);
+    }
+
+    default boolean isSleeping() {
+        return this.lithium$getSleepingTicker() != null;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/chunkwatching/PlayerClientVDTracking.java

@@ -0,0 +1,9 @@
+package net.gensokyoreimagined.nitori.common.chunkwatching;
+
+public interface PlayerClientVDTracking {
+
+    boolean isClientViewDistanceChanged();
+
+    int getClientViewDistance();
+
+}

src/main/java/net/gensokyoreimagined/nitori/common/entity/EntityClassGroup.java

@@ -0,0 +1,111 @@
+package net.gensokyoreimagined.nitori.common.entity;
+
+import it.unimi.dsi.fastutil.objects.Reference2ByteOpenHashMap;
+import net.gensokyoreimagined.nitori.common.reflection.ReflectionUtil;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.boss.enderdragon.EnderDragon;
+import net.minecraft.world.entity.monster.Shulker;
+import net.minecraft.world.entity.projectile.windcharge.WindCharge;
+import net.minecraft.world.entity.vehicle.Minecart;
+
+import java.util.Objects;
+import java.util.function.Predicate;
+import java.util.logging.Logger;
+
+/**
+ * Class for grouping Entity classes by some property for use in TypeFilterableList
+ * It is intended that an EntityClassGroup acts as if it was immutable, however we cannot predict which subclasses of
+ * Entity might appear. Therefore we evaluate whether a class belongs to the class group when it is first seen.
+ * Once a class was evaluated the result of it is cached and cannot be changed.
+ *
+ * @author 2No2Name
+ */
+public class EntityClassGroup {
+    public static final EntityClassGroup CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE; //aka entities that will attempt to collide with all other entities when moving
+
+    static {
+//        String remapped_collidesWith = FabricLoader.getInstance().getMappingResolver().mapMethodName("intermediary", "net.minecraft.class_1297", "method_30949", "(Lnet/minecraft/class_1297;)Z");
+        String remapped_collidesWith = "canCollideWith";
+        CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE = new EntityClassGroup(
+                (Class<?> entityClass) -> ReflectionUtil.hasMethodOverride(entityClass, Entity.class, true, remapped_collidesWith, Entity.class));
+
+        //sanity check: in case intermediary mappings changed, we fail
+        if ((!CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE.contains(Minecart.class))) {
+            throw new AssertionError();
+        }
+        if ((!CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE.contains(WindCharge.class)) || (!CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE.contains(WindCharge.class))) {
+            throw new AssertionError();
+        }
+        if ((CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE.contains(Shulker.class))) {
+            //should not throw an Error here, because another mod *could* add the method to ShulkerEntity. Warning when this sanity check fails.
+            Logger.getLogger("Lithium EntityClassGroup").warning("Either Lithium EntityClassGroup is broken or something else gave Shulkers the minecart-like collision behavior.");
+        }
+        CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE.clear();
+    }
+
+    private final Predicate<Class<?>> classFitEvaluator;
+    private volatile Reference2ByteOpenHashMap<Class<?>> class2GroupContains;
+
+    public EntityClassGroup(Predicate<Class<?>> classFitEvaluator) {
+        this.class2GroupContains = new Reference2ByteOpenHashMap<>();
+        Objects.requireNonNull(classFitEvaluator);
+        this.classFitEvaluator = classFitEvaluator;
+    }
+
+    public void clear() {
+        this.class2GroupContains = new Reference2ByteOpenHashMap<>();
+    }
+
+    public boolean contains(Class<?> entityClass) {
+        byte contains = this.class2GroupContains.getOrDefault(entityClass, (byte) 2);
+        if (contains != 2) {
+            return contains == 1;
+        } else {
+            return this.testAndAddClass(entityClass);
+        }
+    }
+
+    boolean testAndAddClass(Class<?> entityClass) {
+        byte contains;
+        //synchronizing here to avoid multiple threads replacing the map at the same time, and therefore possibly undoing progress
+        //it could also be fixed by using an AtomicReference's CAS, but we are writing very rarely (less than 150 times for the total game runtime in vanilla)
+        synchronized (this) {
+            //test the same condition again after synchronizing, as the collection might have been updated while this thread blocked
+            contains = this.class2GroupContains.getOrDefault(entityClass, (byte) 2);
+            if (contains != 2) {
+                return contains == 1;
+            }
+            //construct new map instead of updating the old map to avoid thread safety problems
+            //the map is not modified after publication
+            Reference2ByteOpenHashMap<Class<?>> newMap = this.class2GroupContains.clone();
+            contains = this.classFitEvaluator.test(entityClass) ? (byte) 1 : (byte) 0;
+            newMap.put(entityClass, contains);
+            //publish the new map in a volatile field, so that all threads reading after this write can also see all changes to the map done before the write
+            this.class2GroupContains = newMap;
+        }
+        return contains == 1;
+    }
+
+    public static class NoDragonClassGroup extends EntityClassGroup {
+        public static final NoDragonClassGroup BOAT_SHULKER_LIKE_COLLISION; //aka entities that other entities will do block-like collisions with when moving
+
+        static {
+//            String remapped_isCollidable = FabricLoader.getInstance().getMappingResolver().mapMethodName("intermediary", "net.minecraft.class_1297", "method_30948", "()Z");
+            String remapped_isCollidable = "canBeCollidedWith";
+            BOAT_SHULKER_LIKE_COLLISION = new NoDragonClassGroup(
+                    (Class<?> entityClass) -> ReflectionUtil.hasMethodOverride(entityClass, Entity.class, true, remapped_isCollidable));
+
+            if ((!BOAT_SHULKER_LIKE_COLLISION.contains(Shulker.class))) {
+                throw new AssertionError();
+            }
+            BOAT_SHULKER_LIKE_COLLISION.clear();
+        }
+
+        public NoDragonClassGroup(Predicate<Class<?>> classFitEvaluator) {
+            super(classFitEvaluator);
+            if (classFitEvaluator.test(EnderDragon.class)) {
+                throw new IllegalArgumentException("EntityClassGroup.NoDragonClassGroup cannot be initialized: Must exclude EnderDragonEntity!");
+            }
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/entity/FluidCachingEntity.java

@@ -0,0 +1,4 @@
+package net.gensokyoreimagined.nitori.common.entity;
+
+public interface FluidCachingEntity {
+}

src/main/java/net/gensokyoreimagined/nitori/common/entity/NavigatingEntity.java

@@ -0,0 +1,14 @@
+package net.gensokyoreimagined.nitori.common.entity;
+
+import net.minecraft.world.entity.ai.navigation.PathNavigation;
+
+public interface NavigatingEntity {
+    boolean lithium$isRegisteredToWorld();
+
+    void lithium$setRegisteredToWorld(PathNavigation navigation);
+
+    PathNavigation lithium$getRegisteredNavigation();
+
+    void lithium$updateNavigationRegistration();
+
+}

src/main/java/net/gensokyoreimagined/nitori/common/entity/block_tracking/ChunkSectionChangeCallback.java

@@ -0,0 +1,104 @@
+package net.gensokyoreimagined.nitori.common.entity.block_tracking;
+
+//import it.unimi.dsi.fastutil.longs.Long2ReferenceOpenHashMap;
+//import net.gensokyoreimagined.nitori.common.block.BlockListeningSection;
+//import net.gensokyoreimagined.nitori.common.block.BlockStateFlags;
+//import net.gensokyoreimagined.nitori.common.block.ListeningBlockStatePredicate;
+//import net.gensokyoreimagined.nitori.common.util.Pos;
+//import net.gensokyoreimagined.nitori.common.world.LithiumData;
+//import net.gensokyoreimagined.nitori.common.world.chunk.ChunkStatusTracker;
+//import net.minecraft.core.SectionPos;
+//import net.minecraft.world.level.Level;
+//import net.minecraft.world.level.chunk.LevelChunkSection;
+//
+//import java.util.ArrayList;
+//
+//public final class ChunkSectionChangeCallback {
+//    private final ArrayList<SectionedBlockChangeTracker>[] trackers;
+//    private short listeningMask;
+//
+//    static {
+//        if (BlockListeningSection.class.isAssignableFrom(LevelChunkSection.class)) {
+//            ChunkStatusTracker.registerUnloadCallback((serverWorld, chunkPos) -> {
+//                Long2ReferenceOpenHashMap<ChunkSectionChangeCallback> changeCallbacks = ((LithiumData) serverWorld).lithium$getData().chunkSectionChangeCallbacks();
+//                int x = chunkPos.x;
+//                int z = chunkPos.z;
+//                for (int y = Pos.SectionYCoord.getMinYSection(serverWorld); y <= Pos.SectionYCoord.getMaxYSectionInclusive(serverWorld); y++) {
+//                    SectionPos chunkSectionPos = SectionPos.of(x, y, z);
+//                    ChunkSectionChangeCallback chunkSectionChangeCallback = changeCallbacks.remove(chunkSectionPos.asLong());
+//                    if (chunkSectionChangeCallback != null) {
+//                        chunkSectionChangeCallback.onChunkSectionInvalidated(chunkSectionPos);
+//                    }
+//                }
+//            });
+//        }
+//    }
+//
+//    public ChunkSectionChangeCallback() {
+//        //noinspection unchecked
+//        this.trackers = new ArrayList[BlockStateFlags.NUM_LISTENING_FLAGS];
+//        this.listeningMask = 0;
+//    }
+//
+//    public static ChunkSectionChangeCallback create(long sectionPos, Level world) {
+//        ChunkSectionChangeCallback chunkSectionChangeCallback = new ChunkSectionChangeCallback();
+//        Long2ReferenceOpenHashMap<ChunkSectionChangeCallback> changeCallbacks = ((LithiumData) world).lithium$getData().chunkSectionChangeCallbacks();
+//        ChunkSectionChangeCallback previous = changeCallbacks.put(sectionPos, chunkSectionChangeCallback);
+//        if (previous != null) {
+//            previous.onChunkSectionInvalidated(SectionPos.of(sectionPos));
+//        }
+//        return chunkSectionChangeCallback;
+//    }
+//
+//    public short onBlockChange(int blockGroupIndex, BlockListeningSection section) {
+//        ArrayList<SectionedBlockChangeTracker> sectionedBlockChangeTrackers = this.trackers[blockGroupIndex];
+//        this.trackers[blockGroupIndex] = null;
+//        if (sectionedBlockChangeTrackers != null) {
+//            //noinspection ForLoopReplaceableByForEach
+//            for (int i = 0; i < sectionedBlockChangeTrackers.size(); i++) {
+//                sectionedBlockChangeTrackers.get(i).setChanged(section);
+//            }
+//        }
+//        this.listeningMask &= (short) ~(1 << blockGroupIndex);
+//
+//        return this.listeningMask;
+//    }
+//
+//    public short addTracker(SectionedBlockChangeTracker tracker, ListeningBlockStatePredicate blockGroup) {
+//        int blockGroupIndex = blockGroup.getIndex();
+//        ArrayList<SectionedBlockChangeTracker> sectionedBlockChangeTrackers = this.trackers[blockGroupIndex];
+//        if (sectionedBlockChangeTrackers == null) {
+//            this.trackers[blockGroupIndex] = (sectionedBlockChangeTrackers = new ArrayList<>());
+//        }
+//        sectionedBlockChangeTrackers.add(tracker);
+//
+//        this.listeningMask |= (short) (1 << blockGroupIndex);
+//        return this.listeningMask;
+//    }
+//
+//    public short removeTracker(SectionedBlockChangeTracker tracker, ListeningBlockStatePredicate blockGroup) {
+//        int blockGroupIndex = blockGroup.getIndex();
+//        ArrayList<SectionedBlockChangeTracker> sectionedBlockChangeTrackers = this.trackers[blockGroupIndex];
+//        if (sectionedBlockChangeTrackers != null) {
+//            sectionedBlockChangeTrackers.remove(tracker);
+//            if (sectionedBlockChangeTrackers.isEmpty()) {
+//                this.listeningMask &= (short) ~(1 << blockGroup.getIndex());
+//            }
+//        }
+//        return this.listeningMask;
+//    }
+//
+//    public void onChunkSectionInvalidated(SectionPos sectionPos) {
+//        for (int flagIndex = 0; flagIndex < this.trackers.length; flagIndex++) {
+//            ArrayList<SectionedBlockChangeTracker> sectionedBlockChangeTrackers = this.trackers[flagIndex];
+//            this.trackers[flagIndex] = null;
+//            if (sectionedBlockChangeTrackers != null) {
+//                //noinspection ForLoopReplaceableByForEach
+//                for (int i = 0; i < sectionedBlockChangeTrackers.size(); i++) {
+//                    sectionedBlockChangeTrackers.get(i).onChunkSectionInvalidated(sectionPos);
+//                }
+//            }
+//        }
+//        this.listeningMask = 0;
+//    }
+//}

src/main/java/net/gensokyoreimagined/nitori/common/entity/block_tracking/SectionedBlockChangeTracker.java

@@ -0,0 +1,211 @@
+package net.gensokyoreimagined.nitori.common.entity.block_tracking;
+
+//import net.gensokyoreimagined.nitori.common.block.BlockListeningSection;
+//import net.gensokyoreimagined.nitori.common.block.ListeningBlockStatePredicate;
+//import net.gensokyoreimagined.nitori.common.util.Pos;
+//import net.gensokyoreimagined.nitori.common.util.deduplication.LithiumInterner;
+//import net.gensokyoreimagined.nitori.common.util.tuples.WorldSectionBox;
+//import net.gensokyoreimagined.nitori.common.world.LithiumData;
+//import net.minecraft.world.phys.AABB;
+//import net.minecraft.core.SectionPos;
+//import net.minecraft.world.level.Level;
+//import net.minecraft.world.level.chunk.ChunkAccess;
+//import net.minecraft.world.level.chunk.LevelChunkSection;
+//import net.minecraft.world.level.chunk.status.ChunkStatus;
+//
+//import java.util.ArrayList;
+//import java.util.Objects;
+//
+//public class SectionedBlockChangeTracker {
+//    public final WorldSectionBox trackedWorldSections;
+//    public final ListeningBlockStatePredicate blockGroup;
+//
+//    private long maxChangeTime;
+//
+//    private int timesRegistered;
+//    //Some sections may not exist / be unloaded. We have to be aware of those. //TODO Invalidation when sections / chunks unload (but the entity does not (?), not sure whether this is possible)
+//    boolean isListeningToAll = false;
+//    private ArrayList<SectionPos> sectionsNotListeningTo = null;
+//    private ArrayList<BlockListeningSection> sectionsUnsubscribed = null;
+//
+//    public SectionedBlockChangeTracker(WorldSectionBox trackedWorldSections, ListeningBlockStatePredicate blockGroup) {
+//        this.trackedWorldSections = trackedWorldSections;
+//        this.blockGroup = blockGroup;
+//
+//        this.maxChangeTime = 0;
+//    }
+//
+//    public boolean matchesMovedBox(AABB box) {
+//        return this.trackedWorldSections.matchesRelevantBlocksBox(box);
+//    }
+//
+//    public static SectionedBlockChangeTracker registerAt(Level world, AABB entityBoundingBox, ListeningBlockStatePredicate blockGroup) {
+//        WorldSectionBox worldSectionBox = WorldSectionBox.relevantExpandedBlocksBox(world, entityBoundingBox);
+//        SectionedBlockChangeTracker tracker = new SectionedBlockChangeTracker(worldSectionBox, blockGroup);
+//
+//        LithiumInterner<SectionedBlockChangeTracker> blockChangeTrackers = ((LithiumData) world).lithium$getData().blockChangeTrackers();
+//        tracker = blockChangeTrackers.getCanonical(tracker);
+//
+//        tracker.register();
+//        return tracker;
+//    }
+//
+//    long getWorldTime() {
+//        return this.trackedWorldSections.world().getGameTime();
+//    }
+//
+//    public void register() {
+//        if (this.timesRegistered == 0) {
+//            WorldSectionBox trackedSections = this.trackedWorldSections;
+//            for (int x = trackedSections.chunkX1(); x < trackedSections.chunkX2(); x++) {
+//                for (int z = trackedSections.chunkZ1(); z < trackedSections.chunkZ2(); z++) {
+//                    Level world = trackedSections.world();
+//                    ChunkAccess chunk = world.getChunk(x, z, ChunkStatus.FULL, false);
+//                    LevelChunkSection[] sectionArray = chunk == null ? null : chunk.getSections();
+//                    for (int y = trackedSections.chunkY1(); y < trackedSections.chunkY2(); y++) {
+//                        if (Pos.SectionYCoord.getMinYSection(world) > y || Pos.SectionYCoord.getMaxYSectionExclusive(world) <= y) {
+//                            continue;
+//                        }
+//                        SectionPos sectionPos = SectionPos.of(x, y, z);
+//                        if (sectionArray == null) {
+//                            if (this.sectionsNotListeningTo == null) {
+//                                this.sectionsNotListeningTo = new ArrayList<>();
+//                            }
+//                            this.sectionsNotListeningTo.add(sectionPos);
+//                            continue;
+//                        }
+//                        LevelChunkSection section = sectionArray[Pos.SectionYIndex.fromSectionCoord(world, y)];
+//
+//                        BlockListeningSection blockListeningSection = (BlockListeningSection) section;
+//                        blockListeningSection.lithium$addToCallback(this.blockGroup, this, SectionPos.asLong(x, y, z), world);
+//                    }
+//                }
+//            }
+//            this.isListeningToAll = (this.sectionsNotListeningTo == null || this.sectionsNotListeningTo.isEmpty())
+//                    && (this.sectionsUnsubscribed == null || this.sectionsUnsubscribed.isEmpty());
+//            this.setChanged(this.getWorldTime());
+//        }
+//        this.timesRegistered++;
+//    }
+//
+//    public void unregister() {
+//        if (--this.timesRegistered > 0) {
+//            return;
+//        }
+//        WorldSectionBox trackedSections = this.trackedWorldSections;
+//        Level world = trackedSections.world();
+//        for (int x = trackedSections.chunkX1(); x < trackedSections.chunkX2(); x++) {
+//            for (int z = trackedSections.chunkZ1(); z < trackedSections.chunkZ2(); z++) {
+//                ChunkAccess chunk = world.getChunk(x, z, ChunkStatus.FULL, false);
+//                LevelChunkSection[] sectionArray = chunk == null ? null : chunk.getSections();
+//                for (int y = trackedSections.chunkY1(); y < trackedSections.chunkY2(); y++) {
+//
+//                    if (sectionArray == null) {
+//                        continue;
+//                    }
+//                    if (Pos.SectionYCoord.getMinYSection(world) > y || Pos.SectionYCoord.getMaxYSectionExclusive(world) <= y) {
+//                        continue;
+//                    }
+//                    LevelChunkSection section = sectionArray[Pos.SectionYIndex.fromSectionCoord(world, y)];
+//
+//                    BlockListeningSection blockListeningSection = (BlockListeningSection) section;
+//                    blockListeningSection.lithium$removeFromCallback(this.blockGroup, this);
+//                }
+//            }
+//        }
+//        this.sectionsNotListeningTo = null;
+//        LithiumInterner<SectionedBlockChangeTracker> blockChangeTrackers = ((LithiumData) world).lithium$getData().blockChangeTrackers();
+//        blockChangeTrackers.deleteCanonical(this);
+//    }
+//
+//    public void listenToAllSections() {
+//        boolean changed = false;
+//        ArrayList<SectionPos> notListeningTo = this.sectionsNotListeningTo;
+//        if (notListeningTo != null) {
+//            for (int i = notListeningTo.size() - 1; i >= 0; i--) {
+//                changed = true;
+//                SectionPos chunkSectionPos = notListeningTo.get(i);
+//                Level world = this.trackedWorldSections.world();
+//                ChunkAccess chunk = world.getChunk(chunkSectionPos.getX(), chunkSectionPos.getZ(), ChunkStatus.FULL, false);
+//                if (chunk != null) {
+//                    notListeningTo.remove(i);
+//                } else {
+//                    //Chunk not loaded, cannot listen to all sections.
+//                    return;
+//                }
+//                LevelChunkSection section = chunk.getSections()[Pos.SectionYIndex.fromSectionCoord(world, chunkSectionPos.getY())];
+//                BlockListeningSection blockListeningSection = (BlockListeningSection) section;
+//                blockListeningSection.lithium$addToCallback(this.blockGroup, this, chunkSectionPos.asLong(), world);
+//            }
+//        }
+//        if (this.sectionsUnsubscribed != null) {
+//            ArrayList<BlockListeningSection> unsubscribed = this.sectionsUnsubscribed;
+//            for (int i = unsubscribed.size() - 1; i >= 0; i--) {
+//                changed = true;
+//                BlockListeningSection blockListeningSection = unsubscribed.remove(i);
+//                blockListeningSection.lithium$addToCallback(this.blockGroup, this, Long.MIN_VALUE, null);
+//            }
+//        }
+//        this.isListeningToAll = true;
+//        if (changed) {
+//            this.setChanged(this.getWorldTime());
+//        }
+//    }
+//
+//    public void setChanged(BlockListeningSection section) {
+//        if (this.sectionsUnsubscribed == null) {
+//            this.sectionsUnsubscribed = new ArrayList<>();
+//        }
+//        this.sectionsUnsubscribed.add(section);
+//        this.setChanged(this.getWorldTime());
+//        this.isListeningToAll = false;
+//    }
+//
+//    public void setChanged(long atTime) {
+//        if (atTime > this.maxChangeTime) {
+//            this.maxChangeTime = atTime;
+//        }
+//    }
+//
+//    /**
+//     * Method to quickly check whether any relevant blocks changed inside the relevant chunk sections after
+//     * the last test.
+//     *
+//     * @param lastCheckedTime time of the last interaction attempt
+//     * @return whether any relevant entity moved in the tracked area
+//     */
+//    public boolean isUnchangedSince(long lastCheckedTime) {
+//        if (lastCheckedTime <= this.maxChangeTime) {
+//            return false;
+//        }
+//        if (!this.isListeningToAll) {
+//            this.listenToAllSections();
+//            return this.isListeningToAll && lastCheckedTime > this.maxChangeTime;
+//        }
+//        return true;
+//    }
+//
+//    //Do not modify, used for deduplication of instances
+//    @Override
+//    public boolean equals(Object obj) {
+//        if (obj == this) return true;
+//        if (obj == null || obj.getClass() != this.getClass()) return false;
+//        var that = (SectionedBlockChangeTracker) obj;
+//        return Objects.equals(this.trackedWorldSections, that.trackedWorldSections) &&
+//                Objects.equals(this.blockGroup, that.blockGroup);
+//    }
+//    //Do not modify, used for deduplication of instances
+//    @Override
+//    public int hashCode() {
+//        return this.getClass().hashCode() ^ this.trackedWorldSections.hashCode() ^ this.blockGroup.hashCode();
+//    }
+//
+//    public void onChunkSectionInvalidated(SectionPos sectionPos) {
+//        if (this.sectionsNotListeningTo == null) {
+//            this.sectionsNotListeningTo = new ArrayList<>();
+//        }
+//        this.sectionsNotListeningTo.add(sectionPos);
+//        this.setChanged(this.getWorldTime());
+//        this.isListeningToAll = false;
+//    }
+//}

src/main/java/net/gensokyoreimagined/nitori/common/entity/movement/ChunkAwareBlockCollisionSweeper.java

@@ -0,0 +1,349 @@
+package net.gensokyoreimagined.nitori.common.entity.movement;
+//
+//import com.google.common.collect.AbstractIterator;
+//import net.gensokyoreimagined.nitori.common.block.BlockCountingSection;
+//import net.gensokyoreimagined.nitori.common.block.BlockStateFlags;
+//import net.gensokyoreimagined.nitori.common.shapes.VoxelShapeCaster;
+//import net.gensokyoreimagined.nitori.common.util.Pos;
+//import net.minecraft.world.level.block.state.BlockState;
+//import net.minecraft.world.level.block.Blocks;
+//import net.minecraft.world.phys.shapes.CollisionContext;
+//import net.minecraft.world.entity.Entity;
+//import net.minecraft.world.phys.shapes.BooleanOp;
+//import net.minecraft.core.BlockPos;
+//import net.minecraft.world.phys.AABB;
+//import net.minecraft.util.Mth;
+//import net.minecraft.world.phys.shapes.VoxelShape;
+//import net.minecraft.world.phys.shapes.Shapes;
+//import net.minecraft.world.level.Level;
+//import net.minecraft.world.level.chunk.ChunkAccess;
+//import net.minecraft.world.level.chunk.LevelChunkSection;
+//import net.minecraft.world.level.chunk.status.ChunkStatus;
+//import org.jetbrains.annotations.Nullable;
+//
+//import java.util.ArrayList;
+//import java.util.Iterator;
+//import java.util.List;
+//import java.util.NoSuchElementException;
+//
+//import static net.gensokyoreimagined.nitori.common.entity.LithiumEntityCollisions.EPSILON;
+//
+///**
+// * ChunkAwareBlockCollisionSweeper iterates over blocks in one chunk section at a time. Together with the chunk
+// * section keeping track of the amount of oversized blocks inside the number of iterations can often be reduced.
+// */
+//public class ChunkAwareBlockCollisionSweeper extends AbstractIterator<VoxelShape> {
+//
+//    private final BlockPos.Mutable pos = new BlockPos.Mutable();
+//
+//    /**
+//     * The collision box being swept through the world.
+//     */
+//    private final AABB box;
+//
+//    /**
+//     * The VoxelShape of the collision box being swept through the world.
+//     */
+//    private final VoxelShape shape;
+//
+//    private final Level world;
+//
+//    private final CollisionContext context;
+//
+//    //limits of the area without extension for oversized blocks
+//    private final int minX, minY, minZ, maxX, maxY, maxZ;
+//
+//    //variables prefixed with c refer to the iteration of the currently cached chunk section
+//    private int chunkX, chunkYIndex, chunkZ;
+//    private int cStartX, cStartZ;
+//    private int cEndX, cEndZ;
+//    private int cX, cY, cZ;
+//
+//    private int maxHitX;
+//    private int maxHitY;
+//    private int maxHitZ;
+//    private VoxelShape maxShape;
+//    private final boolean hideLastCollision;
+//
+//
+//    private int cTotalSize;
+//    private int cIterated;
+//
+//    private boolean sectionOversizedBlocks;
+//    private ChunkAccess cachedChunk;
+//    private LevelChunkSection cachedChunkSection;
+//
+//    public ChunkAwareBlockCollisionSweeper(Level world, @Nullable Entity entity, AABB box) {
+//        this(world, entity, box, false);
+//    }
+//    public ChunkAwareBlockCollisionSweeper(Level world, @Nullable Entity entity, AABB box, boolean hideLastCollision) {
+//        this.box = box;
+//        this.shape = Shapes.cuboid(box);
+//        this.context = entity == null ? CollisionContext.absent() : CollisionContext.of(entity);
+//        this.world = world;
+//
+//        this.minX = Mth.floor(box.minX - EPSILON);
+//        this.maxX = Mth.floor(box.maxX + EPSILON);
+//        this.minY = Mth.clamp(Mth.floor(box.minY - EPSILON), Pos.BlockCoord.getMinY(this.world), Pos.BlockCoord.getMaxYInclusive(this.world));
+//        this.maxY = Mth.clamp(Mth.floor(box.maxY + EPSILON), Pos.BlockCoord.getMinY(this.world), Pos.BlockCoord.getMaxYInclusive(this.world));
+//        this.minZ = Mth.floor(box.minZ - EPSILON);
+//        this.maxZ = Mth.floor(box.maxZ + EPSILON);
+//
+//        this.chunkX = Pos.ChunkCoord.fromBlockCoord(expandMin(this.minX));
+//        this.chunkZ = Pos.ChunkCoord.fromBlockCoord(expandMin(this.minZ));
+//
+//        this.cIterated = 0;
+//        this.cTotalSize = 0;
+//
+//        this.maxHitX = Integer.MIN_VALUE;
+//        this.maxHitY = Integer.MIN_VALUE;
+//        this.maxHitZ = Integer.MIN_VALUE;
+//        this.maxShape = null;
+//        this.hideLastCollision = hideLastCollision;
+//
+//        //decrement as first nextSection call will increment it again
+//        this.chunkX--;
+//    }
+//
+//
+//    public VoxelShape getLastCollision() {
+//        return this.maxShape;
+//    }
+//
+//    public Iterator<VoxelShape> getLastCollisionIterator() {
+//        return new Iterator<>() {
+//            @Override
+//            public boolean hasNext() {
+//                return hideLastCollision && maxShape != null;
+//            }
+//
+//            @Override
+//            public VoxelShape next() {
+//                if (this.hasNext()) {
+//                    VoxelShape previousMaxShape = maxShape;
+//                    maxShape = null;
+//                    return previousMaxShape;
+//                }
+//                throw new NoSuchElementException();
+//            }
+//        };
+//    }
+//
+//    private boolean nextSection() {
+//        do {
+//            do {
+//                //find the coordinates of the next section inside the area expanded by 1 block on all sides
+//                //note: this.minX, maxX etc are not expanded, so there are lots of +1 and -1 around.
+//                if (
+//                        this.cachedChunk != null &&
+//                                this.chunkYIndex < Pos.SectionYIndex.getMaxYSectionIndexInclusive(this.world) &&
+//                                this.chunkYIndex < Pos.SectionYIndex.fromBlockCoord(this.world,expandMax(this.maxY))
+//                ) {
+//                    this.chunkYIndex++;
+//                    this.cachedChunkSection = this.cachedChunk.getSectionArray()[this.chunkYIndex];
+//                } else {
+//                    this.chunkYIndex = Mth.clamp(
+//                            Pos.SectionYIndex.fromBlockCoord(this.world, expandMin(this.minY)),
+//                            Pos.SectionYIndex.getMinYSectionIndex(this.world),
+//                            Pos.SectionYIndex.getMaxYSectionIndexInclusive(this.world)
+//                    );
+//
+//                    if (this.chunkX < Pos.ChunkCoord.fromBlockCoord(expandMax(this.maxX))) {
+//                        //first initialization takes this branch
+//                        this.chunkX++;
+//                    } else {
+//                        this.chunkX = Pos.ChunkCoord.fromBlockCoord(expandMin(this.minX));
+//
+//                        if (this.chunkZ < Pos.ChunkCoord.fromBlockCoord(expandMax(this.maxZ))) {
+//                            this.chunkZ++;
+//                        } else {
+//                            return false; //no more sections to iterate
+//                        }
+//                    }
+//                    this.cachedChunk = this.world.getChunk(this.chunkX, this.chunkZ, ChunkStatus.FULL, false);
+//                    if (this.cachedChunk != null) {
+//                        this.cachedChunkSection = this.cachedChunk.getSectionArray()[this.chunkYIndex];
+//                    }
+//                }
+//                //skip empty chunks and empty chunk sections
+//            } while (this.cachedChunk == null || this.cachedChunkSection == null || this.cachedChunkSection.isEmpty());
+//
+//            this.sectionOversizedBlocks = hasChunkSectionOversizedBlocks(this.cachedChunk, this.chunkYIndex);
+//
+//            int sizeExtension = this.sectionOversizedBlocks ? 1 : 0;
+//
+//            this.cEndX = Math.min(this.maxX + sizeExtension, Pos.BlockCoord.getMaxInSectionCoord(this.chunkX));
+//            int cEndY = Math.min(this.maxY + sizeExtension, Pos.BlockCoord.getMaxYInSectionIndex(this.world, this.chunkYIndex));
+//            this.cEndZ = Math.min(this.maxZ + sizeExtension, Pos.BlockCoord.getMaxInSectionCoord(this.chunkZ));
+//
+//            this.cStartX = Math.max(this.minX - sizeExtension, Pos.BlockCoord.getMinInSectionCoord(this.chunkX));
+//            int cStartY = Math.max(this.minY - sizeExtension, Pos.BlockCoord.getMinYInSectionIndex(this.world, this.chunkYIndex));
+//            this.cStartZ = Math.max(this.minZ - sizeExtension, Pos.BlockCoord.getMinInSectionCoord(this.chunkZ));
+//            this.cX = this.cStartX;
+//            this.cY = cStartY;
+//            this.cZ = this.cStartZ;
+//
+//            this.cTotalSize = (this.cEndX - this.cStartX + 1) * (cEndY - cStartY + 1) * (this.cEndZ - this.cStartZ + 1);
+//            //skip completely empty section iterations
+//        } while (this.cTotalSize == 0);
+//        this.cIterated = 0;
+//
+//        return true;
+//    }
+//
+//    /**
+//     * Advances the sweep forward until finding a block with a box-colliding VoxelShape
+//     *
+//     * @return null if no VoxelShape is left in the area, otherwise the next VoxelShape
+//     */
+//    @Override
+//    public VoxelShape computeNext() {
+//        while (true) {
+//            if (this.cIterated >= this.cTotalSize) {
+//                if (!this.nextSection()) {
+//                    break;
+//                }
+//            }
+//
+//            this.cIterated++;
+//
+//
+//            final int x = this.cX;
+//            final int y = this.cY;
+//            final int z = this.cZ;
+//
+//            //The iteration order within a chunk section is chosen so that it causes a mostly linear array access in the storage.
+//            //In net.minecraft.world.chunk.PalettedContainer.toIndex x gets the 4 least significant bits, z the 4 above, and y the 4 even higher ones.
+//            //Linearly accessing arrays is faster than other access patterns.
+//            if (this.cX < this.cEndX) {
+//                this.cX++;
+//            } else if (this.cZ < this.cEndZ) {
+//                this.cX = this.cStartX;
+//                this.cZ++;
+//            } else {
+//                this.cX = this.cStartX;
+//                this.cZ = this.cStartZ;
+//                this.cY++;
+//                //stop condition was already checked using this.cIterated at the start of the method
+//            }
+//
+//            //using < minX and > maxX instead of <= and >= in vanilla, because minX, maxX are the coordinates
+//            //of the box that wasn't extended for oversized blocks yet.
+//            final int edgesHit = this.sectionOversizedBlocks ?
+//                    (x < this.minX || x > this.maxX ? 1 : 0) +
+//                            (y < this.minY || y > this.maxY ? 1 : 0) +
+//                            (z < this.minZ || z > this.maxZ ? 1 : 0) : 0;
+//
+//            if (edgesHit == 3) {
+//                continue;
+//            }
+//
+//            final BlockState state = this.cachedChunkSection.getBlockState(x & 15, y & 15, z & 15);
+//
+//            if (!canInteractWithBlock(state, edgesHit)) {
+//                continue;
+//            }
+//
+//            this.pos.set(x, y, z);
+//
+//            VoxelShape collisionShape = state.getCollisionShape(this.world, this.pos, this.context);
+//
+//            if (collisionShape != Shapes.empty() && collisionShape != null /*collisionShape should never be null, but we received crash reports.*/) {
+//                VoxelShape collidedShape = getCollidedShape(this.box, this.shape, collisionShape, x, y, z);
+//                if (collidedShape != null) {
+//                    if (z >= this.maxHitZ && (z > this.maxHitZ || y >= this.maxHitY && (y > this.maxHitY || x > this.maxHitX))) {
+//                        this.maxHitX = x;
+//                        this.maxHitY = y;
+//                        this.maxHitZ = z;
+//                        //Always make sure the shape at the maximum position is the last one returned, because
+//                        // the last shape has a different 1e-7 behavior (no next shape that clips movement to 0).
+//                        // This does affect certain contraptions: https://github.com/CaffeineMC/lithium-fabric/issues/443
+//                        VoxelShape previousMaxShape = this.maxShape;
+//                        this.maxShape = collidedShape;
+//                        if (previousMaxShape != null) {
+//                            return previousMaxShape;
+//                        }
+//                    } else {
+//                        return collidedShape;
+//                    }
+//                }
+//            }
+//        }
+//
+//        if (!this.hideLastCollision && this.maxShape != null) {
+//            VoxelShape previousMaxShape = this.maxShape;
+//            this.maxShape = null;
+//            return previousMaxShape;
+//        }
+//
+//        return this.endOfData();
+//    }
+//
+//    /**
+//     * This is an artifact from vanilla which is used to avoid testing shapes in the extended portion of a volume
+//     * unless they are a shape which exceeds their voxel. Pistons must be special-cased here.
+//     *
+//     * @return True if the shape can be interacted with at the given edge boundary
+//     */
+//    private static boolean canInteractWithBlock(BlockState state, int edgesHit) {
+//        return (edgesHit != 1 || state.exceedsCube()) && (edgesHit != 2 || state.getBlock() == Blocks.MOVING_PISTON);
+//    }
+//
+//    /**
+//     * Checks if the {@param entityShape} or {@param entityBox} intersects the given {@param shape} which is translated
+//     * to the given position. This is a very specialized implementation which tries to avoid going through VoxelShape
+//     * for full-cube shapes.
+//     *
+//     * @return A {@link VoxelShape} which contains the shape representing that which was collided with, otherwise null
+//     */
+//    private static VoxelShape getCollidedShape(AABB entityBox, VoxelShape entityShape, VoxelShape shape, int x, int y, int z) {
+//        if (shape == Shapes.fullCube()) {
+//            return entityBox.intersects(x, y, z, x + 1.0, y + 1.0, z + 1.0) ? shape.offset(x, y, z) : null;
+//        }
+//        if (shape instanceof VoxelShapeCaster) {
+//            if (((VoxelShapeCaster) shape).intersects(entityBox, x, y, z)) {
+//                return shape.offset(x, y, z);
+//            } else {
+//                return null;
+//            }
+//        }
+//
+//        shape = shape.offset(x, y, z);
+//
+//        if (Shapes.matchesAnywhere(shape, entityShape, BooleanOp.AND)) {
+//            return shape;
+//        }
+//
+//        return null;
+//    }
+//
+//    private static int expandMin(int coord) {
+//        return coord - 1;
+//    }
+//    private static int expandMax(int coord) {
+//        return coord + 1;
+//    }
+//
+//    /**
+//     * Checks the cached information whether the {@param chunkY} section of the {@param chunk} has oversized blocks.
+//     *
+//     * @return Whether there are any oversized blocks in the chunk section.
+//     */
+//    private static boolean hasChunkSectionOversizedBlocks(ChunkAccess chunk, int chunkY) {
+//        if (BlockStateFlags.ENABLED) {
+//            LevelChunkSection section = chunk.getSectionArray()[chunkY];
+//            return section != null && ((BlockCountingSection) section).lithium$mayContainAny(BlockStateFlags.OVERSIZED_SHAPE);
+//        }
+//        return true; //like vanilla, assume that a chunk section has oversized blocks, when the section mixin isn't loaded
+//    }
+//
+//    public List<VoxelShape> collectAll() {
+//        ArrayList<VoxelShape> collisions = new ArrayList<>();
+//
+//        while (this.hasNext()) {
+//            collisions.add(this.next());
+//        }
+//
+//        return collisions;
+//    }
+//}

src/main/java/net/gensokyoreimagined/nitori/common/entity/movement_tracker/EntityMovementTrackerSection.java

@@ -0,0 +1,18 @@
+package net.gensokyoreimagined.nitori.common.entity.movement_tracker;
+
+//import net.minecraft.world.level.entity.EntityAccess;
+//import net.minecraft.world.level.entity.EntitySectionStorage;
+//
+//public interface EntityMovementTrackerSection {
+//    void lithium$addListener(SectionedEntityMovementTracker<?, ?> listener);
+//
+//    void lithium$removeListener(EntitySectionStorage<?> sectionedEntityCache, SectionedEntityMovementTracker<?, ?> listener);
+//
+//    void lithium$trackEntityMovement(int notificationMask, long time);
+//
+//    long lithium$getChangeTime(int trackedClass);
+//
+//    <S, E extends EntityAccess> void lithium$listenToMovementOnce(SectionedEntityMovementTracker<E, S> listener, int trackedClass);
+//
+//    <S, E extends EntityAccess> void lithium$removeListenToMovementOnce(SectionedEntityMovementTracker<E, S> listener, int trackedClass);
+//}

src/main/java/net/gensokyoreimagined/nitori/common/entity/movement_tracker/MovementTrackerHelper.java

@@ -0,0 +1,54 @@
+package net.gensokyoreimagined.nitori.common.entity.movement_tracker;
+
+import it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap;
+import net.gensokyoreimagined.nitori.api.inventory.LithiumInventory;
+import net.minecraft.world.entity.item.ItemEntity;
+import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.level.block.entity.HopperBlockEntity;
+import net.minecraft.world.level.entity.EntityAccess;
+
+import java.util.List;
+
+public abstract class MovementTrackerHelper {
+    public static final List<Class<?>> MOVEMENT_NOTIFYING_ENTITY_CLASSES;
+    public static volatile Reference2IntOpenHashMap<Class<? extends EntityAccess>> CLASS_2_NOTIFY_MASK;
+    public static final int NUM_MOVEMENT_NOTIFYING_CLASSES;
+
+    static {
+        if (LithiumInventory.class.isAssignableFrom(HopperBlockEntity.class)) {
+            MOVEMENT_NOTIFYING_ENTITY_CLASSES = List.of(ItemEntity.class, Inventory.class);
+        } else {
+            MOVEMENT_NOTIFYING_ENTITY_CLASSES = List.of();
+        }
+
+        CLASS_2_NOTIFY_MASK = new Reference2IntOpenHashMap<>();
+        CLASS_2_NOTIFY_MASK.defaultReturnValue(-1);
+        NUM_MOVEMENT_NOTIFYING_CLASSES = MOVEMENT_NOTIFYING_ENTITY_CLASSES.size();
+    }
+
+    public static int getNotificationMask(Class<? extends EntityAccess> entityClass) {
+        int notificationMask = CLASS_2_NOTIFY_MASK.getInt(entityClass);
+        if (notificationMask == -1) {
+            notificationMask = calculateNotificationMask(entityClass);
+        }
+        return notificationMask;
+    }
+    private static int calculateNotificationMask(Class<? extends EntityAccess> entityClass) {
+        int mask = 0;
+        for (int i = 0; i < MOVEMENT_NOTIFYING_ENTITY_CLASSES.size(); i++) {
+            Class<?> superclass = MOVEMENT_NOTIFYING_ENTITY_CLASSES.get(i);
+            if (superclass.isAssignableFrom(entityClass)) {
+                mask |= 1 << i;
+            }
+        }
+
+        //progress can be lost here, but it can only cost performance
+        //copy on write followed by publication in volatile field guarantees visibility of the final state
+        Reference2IntOpenHashMap<Class<? extends EntityAccess>> copy = CLASS_2_NOTIFY_MASK.clone();
+        copy.put(entityClass, mask);
+        CLASS_2_NOTIFY_MASK = copy;
+
+        return mask;
+    }
+
+}

src/main/java/net/gensokyoreimagined/nitori/common/entity/movement_tracker/SectionedEntityMovementListener.java

@@ -0,0 +1,5 @@
+package net.gensokyoreimagined.nitori.common.entity.movement_tracker;
+
+public interface SectionedEntityMovementListener {
+    void lithium$handleEntityMovement(Class<?> category);
+}

src/main/java/net/gensokyoreimagined/nitori/common/entity/movement_tracker/SectionedEntityMovementTracker.java

@@ -0,0 +1,197 @@
+package net.gensokyoreimagined.nitori.common.entity.movement_tracker;
+
+//import it.unimi.dsi.fastutil.HashCommon;
+//import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet;
+//import net.gensokyoreimagined.nitori.common.util.tuples.WorldSectionBox;
+//import net.gensokyoreimagined.nitori.common.world.LithiumData;
+//import net.gensokyoreimagined.nitori.mixin.util.accessors.ServerEntityManagerAccessor;
+//import net.gensokyoreimagined.nitori.mixin.util.accessors.ServerWorldAccessor;
+//import net.minecraft.server.level.ServerLevel;
+//import net.minecraft.core.SectionPos;
+//import net.minecraft.world.level.Level;
+//import net.minecraft.world.level.entity.EntityAccess;
+//import net.minecraft.world.level.entity.EntitySection;
+//import net.minecraft.world.level.entity.EntitySectionStorage;
+//
+//import java.util.ArrayList;
+//
+//public abstract class SectionedEntityMovementTracker<E extends EntityAccess, S> {
+//    final WorldSectionBox trackedWorldSections;
+//    final Class<S> clazz;
+//    private final int trackedClass;
+//    ArrayList<EntitySection<E>> sortedSections;
+//    boolean[] sectionVisible;
+//    private int timesRegistered;
+//    private final ArrayList<EntityMovementTrackerSection> sectionsNotListeningTo;
+//
+//    private long maxChangeTime;
+//
+//    private ReferenceOpenHashSet<SectionedEntityMovementListener> sectionedEntityMovementListeners;
+//
+//    public SectionedEntityMovementTracker(WorldSectionBox interactionChunks, Class<S> clazz) {
+//        this.clazz = clazz;
+//        this.trackedWorldSections = interactionChunks;
+//        this.trackedClass = MovementTrackerHelper.MOVEMENT_NOTIFYING_ENTITY_CLASSES.indexOf(clazz);
+//        assert this.trackedClass != -1;
+//        this.sectionedEntityMovementListeners = null;
+//        this.sectionsNotListeningTo = new ArrayList<>();
+//    }
+//
+//    @Override
+//    public int hashCode() {
+//        return HashCommon.mix(this.trackedWorldSections.hashCode()) ^ HashCommon.mix(this.trackedClass) ^ this.getClass().hashCode();
+//    }
+//
+//    @Override
+//    public boolean equals(Object obj) {
+//        return obj.getClass() == this.getClass() &&
+//                this.clazz == ((SectionedEntityMovementTracker<?, ?>) obj).clazz &&
+//                this.trackedWorldSections.equals(((SectionedEntityMovementTracker<?, ?>) obj).trackedWorldSections);
+//    }
+//
+//    /**
+//     * Method to quickly check whether any relevant entities moved inside the relevant entity sections after
+//     * the last interaction attempt.
+//     *
+//     * @param lastCheckedTime time of the last interaction attempt
+//     * @return whether any relevant entity moved in the tracked area
+//     */
+//    public boolean isUnchangedSince(long lastCheckedTime) {
+//        if (lastCheckedTime <= this.maxChangeTime) {
+//            return false;
+//        }
+//        if (!this.sectionsNotListeningTo.isEmpty()) {
+//            this.setChanged(this.listenToAllSectionsAndGetMaxChangeTime());
+//            return lastCheckedTime > this.maxChangeTime;
+//        }
+//        return true;
+//    }
+//
+//    private long listenToAllSectionsAndGetMaxChangeTime() {
+//        long maxChangeTime = Long.MIN_VALUE;
+//        ArrayList<EntityMovementTrackerSection> notListeningTo = this.sectionsNotListeningTo;
+//        for (int i = notListeningTo.size() - 1; i >= 0; i--) {
+//            EntityMovementTrackerSection entityMovementTrackerSection = notListeningTo.remove(i);
+//            entityMovementTrackerSection.lithium$listenToMovementOnce(this, this.trackedClass);
+//            maxChangeTime = Math.max(maxChangeTime, entityMovementTrackerSection.lithium$getChangeTime(this.trackedClass));
+//        }
+//        return maxChangeTime;
+//    }
+//
+//    public void register(ServerLevel world) {
+//        assert world == this.trackedWorldSections.world();
+//
+//        if (this.timesRegistered == 0) {
+//            //noinspection unchecked
+//            EntitySectionStorage<E> cache = ((ServerEntityManagerAccessor<E>) ((ServerWorldAccessor) world).getEntityManager()).getSectionStorage();
+//
+//            WorldSectionBox trackedSections = this.trackedWorldSections;
+//            int size = trackedSections.numSections();
+//            assert size > 0;
+//            this.sortedSections = new ArrayList<>(size);
+//            this.sectionVisible = new boolean[size];
+//
+//            //vanilla iteration order in EntitySectionStorage is xzy
+//            //WorldSectionBox upper coordinates are exclusive
+//            for (int x = trackedSections.chunkX1(); x < trackedSections.chunkX2(); x++) {
+//                for (int z = trackedSections.chunkZ1(); z < trackedSections.chunkZ2(); z++) {
+//                    for (int y = trackedSections.chunkY1(); y < trackedSections.chunkY2(); y++) {
+//                        EntitySection<E> section = cache.getSection(SectionPos.asLong(x, y, z));
+//                        EntityMovementTrackerSection sectionAccess = (EntityMovementTrackerSection) section;
+//                        this.sortedSections.add(section);
+//                        sectionAccess.lithium$addListener(this);
+//                    }
+//                }
+//            }
+//            this.setChanged(world.getGameTime());
+//        }
+//
+//        this.timesRegistered++;
+//    }
+//
+//    public void unRegister(Level world) {
+//        assert world == this.trackedWorldSections.world();
+//        if (--this.timesRegistered > 0) {
+//            return;
+//        }
+//        assert this.timesRegistered == 0;
+//        //noinspection unchecked
+//        EntitySectionStorage<E> cache = ((ServerEntityManagerAccessor<E>) ((ServerWorldAccessor) world).getEntityManager()).getSectionStorage();
+//        ((LithiumData) world).lithium$getData().entityMovementTrackers().deleteCanonical(this);
+//
+//        ArrayList<EntitySection<E>> sections = this.sortedSections;
+//        for (int i = sections.size() - 1; i >= 0; i--) {
+//            EntitySection<E> section = sections.get(i);
+//            EntityMovementTrackerSection sectionAccess = (EntityMovementTrackerSection) section;
+//            sectionAccess.lithium$removeListener(cache, this);
+//            if (!this.sectionsNotListeningTo.remove(section)) {
+//                ((EntityMovementTrackerSection) section).lithium$removeListenToMovementOnce(this, this.trackedClass);
+//            }
+//        }
+//        this.setChanged(world.getGameTime());
+//    }
+//
+//    /**
+//     * Register an entity section to this listener, so this listener can look for changes in the section.
+//     */
+//    public void onSectionEnteredRange(EntityMovementTrackerSection section) {
+//        this.setChanged(this.trackedWorldSections.world().getGameTime());
+//        //noinspection SuspiciousMethodCalls
+//        int sectionIndex = this.sortedSections.lastIndexOf(section);
+//        this.sectionVisible[sectionIndex] = true;
+//
+//        this.sectionsNotListeningTo.add(section);
+//        this.notifyAllListeners();
+//    }
+//
+//    public void onSectionLeftRange(EntityMovementTrackerSection section) {
+//        this.setChanged(this.trackedWorldSections.world().getGameTime());
+//        //noinspection SuspiciousMethodCalls
+//        int sectionIndex = this.sortedSections.lastIndexOf(section);
+//
+//        this.sectionVisible[sectionIndex] = false;
+//
+//        if (!this.sectionsNotListeningTo.remove(section)) {
+//            section.lithium$removeListenToMovementOnce(this, this.trackedClass);
+//            this.notifyAllListeners();
+//        }
+//    }
+//
+//    /**
+//     * Method that marks that new entities might have appeared or moved in the tracked chunk sections.
+//     */
+//    private void setChanged(long atTime) {
+//        if (atTime > this.maxChangeTime) {
+//            this.maxChangeTime = atTime;
+//        }
+//    }
+//
+//    public void listenToEntityMovementOnce(SectionedEntityMovementListener listener) {
+//        if (this.sectionedEntityMovementListeners == null) {
+//            this.sectionedEntityMovementListeners = new ReferenceOpenHashSet<>();
+//        }
+//        this.sectionedEntityMovementListeners.add(listener);
+//
+//        if (!this.sectionsNotListeningTo.isEmpty()) {
+//            this.setChanged(this.listenToAllSectionsAndGetMaxChangeTime());
+//        }
+//
+//    }
+//
+//    public void emitEntityMovement(int classMask, EntityMovementTrackerSection section) {
+//        if ((classMask & (1 << this.trackedClass)) != 0) {
+//            this.notifyAllListeners();
+//            this.sectionsNotListeningTo.add(section);
+//        }
+//    }
+//
+//    private void notifyAllListeners() {
+//        ReferenceOpenHashSet<SectionedEntityMovementListener> listeners = this.sectionedEntityMovementListeners;
+//        if (listeners != null && !listeners.isEmpty()) {
+//            for (SectionedEntityMovementListener listener : listeners) {
+//                listener.lithium$handleEntityMovement(this.clazz);
+//            }
+//            listeners.clear();
+//        }
+//    }
+//}

src/main/java/net/gensokyoreimagined/nitori/common/entity/pushable/BlockCachingEntity.java

@@ -0,0 +1,20 @@
+package net.gensokyoreimagined.nitori.common.entity.pushable;
+
+import net.minecraft.world.level.block.state.BlockState;
+
+public interface BlockCachingEntity {
+
+    default void lithium$OnBlockCacheDeleted() {
+
+    }
+
+    default void lithium$OnBlockCacheSet(BlockState newState) {
+
+    }
+
+    default void lithium$SetClimbingMobCachingSectionUpdateBehavior(boolean listening) {
+        throw new UnsupportedOperationException();
+    }
+
+    BlockState lithium$getCachedFeetBlockState();
+}

src/main/java/net/gensokyoreimagined/nitori/common/entity/pushable/EntityPushablePredicate.java

@@ -0,0 +1,14 @@
+package net.gensokyoreimagined.nitori.common.entity.pushable;
+
+import java.util.function.Predicate;
+
+public abstract class EntityPushablePredicate<S> implements Predicate<S> {
+    public static <T> Predicate<T> and(Predicate<? super T> first, Predicate<? super T> second) {
+        return new EntityPushablePredicate<T>() {
+            @Override
+            public boolean test(T t) {
+                return first.test(t) && second.test(t);
+            }
+        };
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/math/FasterMathUtil.java

@@ -0,0 +1,46 @@
+package net.gensokyoreimagined.nitori.common.math;
+
+/**
+ * @author jafama library
+ * https://github.com/jeffhain/jafama
+ */
+public final class FasterMathUtil {
+    private static final int MAX_FLOAT_EXPONENT = 127;
+    private static final int MAX_DOUBLE_EXPONENT = 1023;
+
+    public static int round(float a) {
+        final int bits = Float.floatToRawIntBits(a);
+        final int biasedExp = ((bits >> 23) & 0xFF);
+        final int shift = (23 - 1 + MAX_FLOAT_EXPONENT) - biasedExp;
+        if ((shift & -32) == 0) {
+            int bitsSignum = (((bits >> 31) << 1) + 1);
+            int extendedMantissa = (0x00800000 | (bits & 0x007FFFFF)) * bitsSignum;
+            return ((extendedMantissa >> shift) + 1) >> 1;
+        } else {
+            return (int) a;
+        }
+    }
+
+    public static long round(double a) {
+        final long bits = Double.doubleToRawLongBits(a);
+        final int biasedExp = (((int)(bits >> 52)) & 0x7FF);
+        final int shift = (52 - 1 + MAX_DOUBLE_EXPONENT) - biasedExp;
+        if ((shift & -64) == 0) {
+            long bitsSignum = (((bits >> 63) << 1) + 1);
+            long extendedMantissa = (0x0010000000000000L | (bits & 0x000FFFFFFFFFFFFFL)) * bitsSignum;
+            return ((extendedMantissa >> shift) + 1L) >> 1;
+        } else {
+            return (long) a;
+        }
+    }
+
+    public static float positiveModuloForPositiveIntegerDivisor(float dividend, float divisor) {
+        var modulo = dividend % divisor;
+        return modulo < 0 ? modulo + divisor : modulo;
+    }
+
+    public static double positiveModuloForPositiveIntegerDivisor(double dividend, double divisor) {
+        var modulo = dividend % divisor;
+        return modulo < 0 ? modulo + divisor : modulo;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/math/random/RandomGeneratorRandom.java

@@ -0,0 +1,116 @@
+package net.gensokyoreimagined.nitori.common.math.random;
+
+import com.google.common.annotations.VisibleForTesting;
+import net.minecraft.util.Mth;
+import net.minecraft.world.level.levelgen.BitRandomSource;
+import net.minecraft.world.level.levelgen.LegacyRandomSource;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.levelgen.PositionalRandomFactory;
+
+import java.util.random.RandomGenerator;
+import java.util.random.RandomGeneratorFactory;
+
+public class RandomGeneratorRandom implements BitRandomSource {
+    private static final RandomGeneratorFactory<RandomGenerator.SplittableGenerator> RANDOM_GENERATOR_FACTORY = RandomGeneratorFactory.of("L64X128MixRandom");
+
+    private static final int INT_BITS = 48;
+    private static final long SEED_MASK = 0xFFFFFFFFFFFFL;
+    private static final long MULTIPLIER = 25214903917L;
+    private static final long INCREMENT = 11L;
+
+    private long seed;
+    private RandomGenerator.SplittableGenerator randomGenerator;
+
+    public RandomGeneratorRandom(long seed) {
+        this.seed = seed;
+        this.randomGenerator = RANDOM_GENERATOR_FACTORY.create(seed);
+    }
+
+    @Override
+    public RandomSource fork() {
+        return new RandomGeneratorRandom(this.nextLong());
+    }
+
+    @Override
+    public PositionalRandomFactory forkPositional() {
+        return new Splitter(this.nextLong());
+    }
+
+    @Override
+    public void setSeed(long seed) {
+        this.seed = seed;
+        this.randomGenerator = RANDOM_GENERATOR_FACTORY.create(seed);
+    }
+
+    @Override
+    public int next(int bits) {
+        // >>> instead of Mojang's >> fixes MC-239059
+        return (int) ((seed * MULTIPLIER + INCREMENT & SEED_MASK) >>> INT_BITS - bits);
+    }
+
+    @Override
+    public int nextInt() {
+        return randomGenerator.nextInt();
+    }
+
+    @Override
+    public int nextInt(int bound) {
+        return randomGenerator.nextInt(bound);
+    }
+
+    @Override
+    public long nextLong() {
+        return randomGenerator.nextLong();
+    }
+
+    @Override
+    public boolean nextBoolean() {
+        return randomGenerator.nextBoolean();
+    }
+
+    @Override
+    public float nextFloat() {
+        return randomGenerator.nextFloat();
+    }
+
+    @Override
+    public double nextDouble() {
+        return randomGenerator.nextDouble();
+    }
+
+    @Override
+    public double nextGaussian() {
+        return randomGenerator.nextGaussian();
+    }
+
+    private record Splitter(long seed) implements PositionalRandomFactory {
+        @Override
+        public RandomSource at(int x, int y, int z) {
+            return new RandomGeneratorRandom(Mth.getSeed(x, y, z) ^ this.seed);
+        }
+
+        @Override
+        public RandomSource fromHashOf(String seed) {
+            return new RandomGeneratorRandom((long) seed.hashCode() ^ this.seed);
+        }
+
+        @Override
+        public RandomSource fromSeed(long seed) {
+            return new RandomGeneratorRandom(seed ^ this.seed);
+        }
+
+		/*
+		@Override
+		public Random split(long seed) {
+			return new RandomGeneratorRandom(seed);
+		}
+
+		 */
+
+        @Override
+        @VisibleForTesting
+        public void parityConfigString(StringBuilder info) {
+            info.append("RandomGeneratorRandom$Splitter{").append(this.seed).append("}");
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/reflection/ReflectionUtil.java

@@ -0,0 +1,71 @@
+package net.gensokyoreimagined.nitori.common.reflection;
+
+import net.minecraft.world.level.block.state.BlockBehaviour;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.ReportedException;
+import net.minecraft.CrashReport;
+import net.minecraft.CrashReportCategory;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.WeakHashMap;
+
+public class ReflectionUtil {
+
+    public static boolean hasMethodOverride(Class<?> clazz, Class<?> superclass, boolean fallbackResult, String methodName, Class<?>... methodArgs) {
+        while (clazz != null && clazz != superclass && superclass.isAssignableFrom(clazz)) {
+            try {
+                clazz.getDeclaredMethod(methodName, methodArgs);
+                return true;
+            } catch (NoSuchMethodException e) {
+                clazz = clazz.getSuperclass();
+            } catch (NoClassDefFoundError error) {
+                Logger logger = LogManager.getLogger("Lithium Class Analysis");
+                logger.warn("Lithium Class Analysis Error: Class " + clazz.getName() + " cannot be analysed, because" +
+                        " getting declared methods crashes with NoClassDefFoundError: " + error.getMessage() +
+                        ". This is usually caused by modded" +
+                        " entities declaring methods that have a return type or parameter type that is annotated" +
+                        " with @Environment(value=EnvType.CLIENT). Loading the type is not possible, because" +
+                        " it only exists in the CLIENT environment. The recommended fix is to annotate the method with" +
+                        " this argument or return type with the same annotation." +
+                        " Lithium handles this error by assuming the class cannot be included in some optimizations.");
+                return fallbackResult;
+            } catch (Throwable e) {
+                final String crashedClass = clazz.getName();
+                CrashReport crashReport = CrashReport.forThrowable(e, "Lithium Class Analysis");
+                CrashReportCategory crashReportSection = crashReport.addCategory(e.getClass().toString() + " when getting declared methods.");
+                crashReportSection.setDetail("Analyzed class", crashedClass);
+                crashReportSection.setDetail("Analyzed method name", methodName);
+                crashReportSection.setDetail("Analyzed method args", methodArgs);
+
+                throw new ReportedException(crashReport);
+            }
+        }
+        return false;
+    }
+
+    //How to find the remapped methods:
+    //1) Run in the debugger: System.out.println(FabricLoader.getInstance().getMappingResolver().getNamespaceData("intermediary").methodNames)
+    //2) Ctrl+F for the method name, in this case "onEntityCollision". Make sure to find the correct one.
+//    private static final String REMAPPED_ON_ENTITY_COLLISION = FabricLoader.getInstance().getMappingResolver().mapMethodName("intermediary", "net.minecraft.class_4970", "method_9548", "(Lnet/minecraft/class_2680;Lnet/minecraft/class_1937;Lnet/minecraft/class_2338;Lnet/minecraft/class_1297;)V");
+    private static final String REMAPPED_ON_ENTITY_COLLISION = "entityInside";
+    private static final WeakHashMap<Class<?>, Boolean> CACHED_IS_ENTITY_TOUCHABLE = new WeakHashMap<>();
+    public static boolean isBlockStateEntityTouchable(BlockState operand) {
+        Class<? extends Block> blockClazz = operand.getBlock().getClass();
+        //Caching results in hashmap as this calculation takes over a second for all blocks together
+        Boolean result = CACHED_IS_ENTITY_TOUCHABLE.get(blockClazz);
+        if (result != null) {
+            return result;
+        }
+        boolean res = ReflectionUtil.hasMethodOverride(blockClazz, BlockBehaviour.class, true, REMAPPED_ON_ENTITY_COLLISION, BlockState.class, Level.class, BlockPos.class, Entity.class);
+        CACHED_IS_ENTITY_TOUCHABLE.put(blockClazz, res);
+        return res;
+    }
+}
+
+
+//TODO: There's bunch of client sided options, we need to safely remove them if possible if not keep the behaviour since mixins work regardless of client or not

src/main/java/net/gensokyoreimagined/nitori/common/shapes/VoxelShapeCaster.java

@@ -0,0 +1,19 @@
+package net.gensokyoreimagined.nitori.common.shapes;
+
+//import net.minecraft.world.phys.shapes.BooleanOp;
+//import net.minecraft.world.phys.AABB;
+//import net.minecraft.world.phys.shapes.VoxelShape;
+//
+//
+//public interface VoxelShapeCaster {
+//    /**
+//     * Checks whether an entity's bounding box collides with this shape translated to the given coordinates.
+//     *
+//     * @param box    The entity's bounding box
+//     * @param blockX The x-coordinate of this shape
+//     * @param blockY The y-coordinate of this shape
+//     * @param blockZ The z-coordinate of this shape
+//     * @return True if the box intersects with this shape, otherwise false
+//     */
+//    boolean intersects(AABB box, double blockX, double blockY, double blockZ);
+//}

src/main/java/net/gensokyoreimagined/nitori/common/state/FastImmutableTable.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.common.state;
 
 import com.google.common.collect.Table;
 import it.unimi.dsi.fastutil.Hash;

src/main/java/net/gensokyoreimagined/nitori/common/state/FastImmutableTableCache.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.common.state;
 
 import it.unimi.dsi.fastutil.Hash;
 import it.unimi.dsi.fastutil.ints.IntArrays;

src/main/java/net/gensokyoreimagined/nitori/common/state/StatePropertyTableCache.java

@@ -0,0 +1,55 @@
+// Nitori Copyright (C) 2024 Gensokyo Reimagined
+//
+// 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 net.gensokyoreimagined.nitori.common.state;
+
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.block.state.properties.Property;
+import net.minecraft.world.level.material.Fluid;
+import net.minecraft.world.level.material.FluidState;
+
+
+
+
+/**
+ * Many of the column and row key arrays in block state tables will be duplicated, leading to an unnecessary waste of
+ * memory. Since we have very limited options for trying to construct more optimized table types without throwing
+ * maintainability or mod compatibility out the window, this class acts as a dirty way to find and de-duplicate arrays
+ * after we construct our table types.
+ * <p>
+ * While this global cache does not provide the ability to remove or clear entries from it, the reality is that it
+ * shouldn't matter because block state tables are only initialized once and remain loaded for the entire lifetime of
+ * the game. Even in the event of classloader pre-boot shenanigans, we still shouldn't leak memory as our cache will be
+ * dropped along with the rest of the loaded classes when the class loader is reaped.
+ */
+public class StatePropertyTableCache {
+    public static final FastImmutableTableCache<Property<?>, Comparable<?>, BlockState> BLOCK_STATE_TABLE =
+            new FastImmutableTableCache<>();
+
+    public static final FastImmutableTableCache<Property<?>, Comparable<?>, FluidState> FLUID_STATE_TABLE =
+            new FastImmutableTableCache<>();
+
+    @SuppressWarnings("unchecked")
+    public static <S, O> FastImmutableTableCache<Property<?>, Comparable<?>, S> getTableCache(O owner) {
+        if (owner instanceof Block) {
+            return (FastImmutableTableCache<Property<?>, Comparable<?>, S>) BLOCK_STATE_TABLE;
+        } else if (owner instanceof Fluid) {
+            return (FastImmutableTableCache<Property<?>, Comparable<?>, S>) FLUID_STATE_TABLE;
+        } else {
+            throw new IllegalArgumentException("");
+        }
+    }
+}
+

src/main/java/net/gensokyoreimagined/nitori/common/util/ArrayConstants.java

@@ -0,0 +1,11 @@
+package net.gensokyoreimagined.nitori.common.util;
+
+/**
+ * Pre-initialized constants to avoid unnecessary allocations.
+ */
+public final class ArrayConstants {
+    private ArrayConstants() {}
+
+    public static final int[] EMPTY = new int[0];
+    public static final int[] ZERO = new int[]{0};
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/EquipmentSlotConstants.java

@@ -0,0 +1,12 @@
+package net.gensokyoreimagined.nitori.common.util;
+
+import net.minecraft.world.entity.EquipmentSlot;
+
+/**
+ * Pre-initialized constants to avoid unnecessary allocations.
+ */
+public final class EquipmentSlotConstants {
+    private EquipmentSlotConstants() {}
+
+    public static final EquipmentSlot[] ALL = EquipmentSlot.values();
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/collections/LazyList.java

@@ -0,0 +1,106 @@
+package net.gensokyoreimagined.nitori.common.util.collections;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.AbstractList;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+
+public class LazyList<T> extends AbstractList<T> {
+
+    private final ArrayList<T> delegate;
+    private Iterator<T> iterator;
+
+    public LazyList(ArrayList<T> delegate, Iterator<T> iterator) {
+        this.delegate = delegate;
+        this.iterator = iterator;
+    }
+
+    private boolean produceToIndex(int n) {
+        n -= this.delegate.size();
+        if (n >= 0 && this.iterator != null) {
+            while (this.iterator.hasNext()) {
+                this.delegate.add(this.iterator.next());
+                if (--n < 0) {
+                    return true;
+                }
+            }
+            this.iterator = null;
+        }
+        return n < 0;
+    }
+
+    @Override
+    public T get(int index) {
+        this.produceToIndex(index);
+        return this.delegate.get(index);
+    }
+
+    @Override
+    public int size() {
+        this.produceToIndex(Integer.MAX_VALUE);
+        return this.delegate.size();
+    }
+
+    @Override
+    public @NotNull Iterator<T> iterator() {
+        return new Iterator<T>() {
+            private int index = 0;
+
+            @Override
+            public boolean hasNext() {
+                return LazyList.this.produceToIndex(this.index);
+            }
+
+            @Override
+            public T next() {
+                return LazyList.this.get(this.index++);
+            }
+        };
+    }
+
+    @Override
+    public T set(int index, T element) {
+        this.produceToIndex(index);
+        return this.delegate.set(index, element);
+    }
+
+    @Override
+    public void add(int index, T element) {
+        this.produceToIndex(index - 1);
+        this.delegate.add(index, element);
+    }
+
+    @Override
+    public T remove(int index) {
+        this.produceToIndex(index);
+        return this.delegate.remove(index);
+    }
+
+    @Override
+    public void clear() {
+        this.delegate.clear();
+        this.iterator = null;
+    }
+
+    @Override
+    public boolean add(T t) {
+        this.produceToIndex(Integer.MAX_VALUE);
+        return this.delegate.add(t);
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return !this.produceToIndex(0);
+    }
+
+    @Override
+    public boolean addAll(int index, Collection<? extends T> c) {
+        if (c.isEmpty()) {
+            return false;
+        }
+        this.produceToIndex(index - 1);
+        return this.delegate.addAll(index, c);
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/collections/MaskedList.java

@@ -0,0 +1,149 @@
+package net.gensokyoreimagined.nitori.common.util.collections;
+
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+
+import java.util.*;
+import java.util.function.Consumer;
+
+public class MaskedList<E> extends AbstractList<E> {
+    private final ObjectArrayList<E> allElements;
+    private final BitSet visibleMask;
+    private final Object2IntOpenHashMap<E> element2Index;
+    private final boolean defaultVisibility;
+    private int numCleared;
+
+    public MaskedList(ObjectArrayList<E> allElements, boolean defaultVisibility) {
+        this.allElements = new ObjectArrayList<>();
+        this.visibleMask = new BitSet();
+        this.defaultVisibility = defaultVisibility;
+        this.element2Index = new Object2IntOpenHashMap<>();
+        this.element2Index.defaultReturnValue(-1);
+
+        this.addAll(allElements);
+    }
+
+    public MaskedList() {
+        this(new ObjectArrayList<>(), true);
+    }
+
+    public int totalSize() {
+        return this.allElements.size();
+    }
+
+
+    public void addOrSet(E element, boolean visible) {
+        int index = this.element2Index.getInt(element);
+        if (index != -1) {
+            this.visibleMask.set(index, visible);
+        } else {
+            this.add(element);
+            this.setVisible(element, visible);
+        }
+    }
+
+    public void setVisible(E element, final boolean visible) {
+        int index = this.element2Index.getInt(element);
+        if (index != -1) {
+            this.visibleMask.set(index, visible);
+        }
+        //ignore when the element is not in the collection
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+        return new Iterator<>() {
+            int nextIndex = 0;
+            int cachedNext = -1;
+
+            @Override
+            public boolean hasNext() {
+                return (this.cachedNext = MaskedList.this.visibleMask.nextSetBit(this.nextIndex)) != -1;
+            }
+
+            @Override
+            public E next() {
+                int index = this.cachedNext;
+                this.cachedNext = -1;
+                this.nextIndex = index + 1;
+                return MaskedList.this.allElements.get(index);
+            }
+        };
+    }
+
+    @Override
+    public Spliterator<E> spliterator() {
+        return new Spliterators.AbstractSpliterator<E>(Long.MAX_VALUE, Spliterator.ORDERED | Spliterator.NONNULL) {
+            int nextIndex = 0;
+
+            @Override
+            public boolean tryAdvance(Consumer<? super E> action) {
+                int index = MaskedList.this.visibleMask.nextSetBit(this.nextIndex);
+                if (index == -1) {
+                    return false;
+                }
+                this.nextIndex = index + 1;
+                action.accept(MaskedList.this.allElements.get(index));
+                return true;
+            }
+        };
+    }
+
+    @Override
+    public boolean add(E e) {
+        int oldIndex = this.element2Index.put(e, this.allElements.size());
+        if (oldIndex != -1) {
+            throw new IllegalStateException("MaskedList must not contain duplicates! Trying to add " + e + " but it is already present at index " + oldIndex + ". Current size: " + this.allElements.size());
+        }
+        this.visibleMask.set(this.allElements.size(), this.defaultVisibility);
+        return this.allElements.add(e);
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        int index = this.element2Index.removeInt(o);
+        if (index == -1) {
+            return false;
+        }
+        this.visibleMask.clear(index);
+        this.allElements.set(index, null);
+        this.numCleared++;
+
+
+        if (this.numCleared * 2 > this.allElements.size()) {
+            ObjectArrayList<E> clonedElements = this.allElements.clone();
+            BitSet clonedVisibleMask = (BitSet) this.visibleMask.clone();
+            this.allElements.clear();
+            this.visibleMask.clear();
+            this.element2Index.clear();
+            for (int i = 0; i < clonedElements.size(); i++) {
+                E element = clonedElements.get(i);
+                int newIndex = this.allElements.size();
+                this.allElements.add(element);
+                this.visibleMask.set(newIndex, clonedVisibleMask.get(i));
+                this.element2Index.put(element, newIndex);
+            }
+            this.numCleared = 0;
+        }
+        return true;
+    }
+
+    @Override
+    public E get(int index) {
+        if (index < 0 || index >= this.size()) {
+            throw new IndexOutOfBoundsException(index);
+        }
+
+        int i = 0;
+        while (index >= 0) {
+            index--;
+            i = this.visibleMask.nextSetBit(i + 1);
+        }
+        return this.allElements.get(i);
+    }
+
+    @Override
+    public int size() {
+        return this.visibleMask.cardinality();
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/collections/Object2BooleanCacheTable.java

@@ -0,0 +1,74 @@
+// Nitori Copyright (C) 2024 Gensokyo Reimagined
+//
+// 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 net.gensokyoreimagined.nitori.common.util.collections;
+
+import it.unimi.dsi.fastutil.HashCommon;
+import net.minecraft.util.Mth;
+
+import java.util.function.Predicate;
+
+/**
+ * A lossy hashtable implementation that stores a mapping between an object and a boolean.
+ * <p>
+ * Any hash collisions will result in an overwrite: this is safe because the correct value can always be recomputed,
+ * given that the given operator is deterministic.
+ * <p>
+ * This implementation is safe to use from multiple threads
+ */
+public final class Object2BooleanCacheTable<T> {
+    private final int mask;
+
+    private final Node<T>[] nodes;
+
+    private final Predicate<T> operator;
+
+    @SuppressWarnings("unchecked")
+    public Object2BooleanCacheTable(int capacity, Predicate<T> operator) {
+        int capacity1 = Mth.smallestEncompassingPowerOfTwo(capacity);
+        this.mask = capacity1 - 1;
+
+        this.nodes = (Node<T>[]) new Node[capacity1];
+
+        this.operator = operator;
+    }
+
+    private static <T> int hash(T key) {
+        return HashCommon.mix(key.hashCode());
+    }
+
+    public boolean get(T key) {
+        int idx = hash(key) & this.mask;
+
+        Node<T> node = this.nodes[idx];
+        if (node != null && key.equals(node.key)) {
+            return node.value;
+        }
+
+        boolean test = this.operator.test(key);
+        this.nodes[idx] = new Node<>(key, test);
+
+        return test;
+    }
+
+    static class Node<T> {
+        final T key;
+        final boolean value;
+
+        Node(T key, boolean value) {
+            this.key = key;
+            this.value = value;
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/deduplication/LithiumInterner.java

@@ -0,0 +1,16 @@
+package net.gensokyoreimagined.nitori.common.util.deduplication;
+
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
+
+public class LithiumInterner<T> {
+    private final ObjectOpenHashSet<T> canonicalStorage = new ObjectOpenHashSet<>();
+
+    public <S extends T> S getCanonical(S value) {
+        //noinspection unchecked
+        return (S) this.canonicalStorage.addOrGet(value);
+    }
+
+    public void deleteCanonical(T value) {
+        this.canonicalStorage.remove(value);
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/deduplication/LithiumInternerWrapper.java

@@ -0,0 +1,8 @@
+package net.gensokyoreimagined.nitori.common.util.deduplication;
+
+public interface LithiumInternerWrapper<T> {
+
+    T lithium$getCanonical(T value);
+
+    void lithium$deleteCanonical(T value);
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/network/VarIntUtil.java

@@ -0,0 +1,20 @@
+package net.gensokyoreimagined.nitori.common.util.network;
+
+/**
+ * Maps VarInt byte sizes to a lookup table corresponding to the number of bits in the integer,
+ * from zero to 32.
+ */
+public class VarIntUtil {
+    private static final int[] VARINT_EXACT_BYTE_LENGTHS = new int[33];
+
+    static {
+        for (int i = 0; i <= 32; ++i) {
+            VARINT_EXACT_BYTE_LENGTHS[i] = (int) Math.ceil((31d - (i - 1)) / 7d);
+        }
+        VARINT_EXACT_BYTE_LENGTHS[32] = 1; // Special case for 0.
+    }
+
+    public static int getVarIntLength(int value) {
+        return VARINT_EXACT_BYTE_LENGTHS[Integer.numberOfLeadingZeros(value)];
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/util/tuples/WorldSectionBox.java

@@ -0,0 +1,57 @@
+package net.gensokyoreimagined.nitori.common.util.tuples;
+
+import net.minecraft.world.phys.AABB;
+import net.minecraft.core.SectionPos;
+import net.minecraft.util.Mth;
+import net.minecraft.world.level.Level;
+
+//Y values use coordinates, not indices (y=0 -> chunkY=0)
+//upper bounds are EXCLUSIVE
+public record WorldSectionBox(Level world, int chunkX1, int chunkY1, int chunkZ1, int chunkX2, int chunkY2,
+                              int chunkZ2) {
+    public static WorldSectionBox entityAccessBox(Level world, AABB box) {
+        int minX = SectionPos.blockToSectionCoord(box.minX - 2.0D);
+        int minY = SectionPos.blockToSectionCoord(box.minY - 4.0D);
+        int minZ = SectionPos.blockToSectionCoord(box.minZ - 2.0D);
+        int maxX = SectionPos.blockToSectionCoord(box.maxX + 2.0D) + 1;
+        int maxY = SectionPos.blockToSectionCoord(box.maxY) + 1;
+        int maxZ = SectionPos.blockToSectionCoord(box.maxZ + 2.0D) + 1;
+        return new WorldSectionBox(world, minX, minY, minZ, maxX, maxY, maxZ);
+    }
+
+    //Relevant block box: Entity hitbox expanded to all blocks it touches. Then expand the resulting box by 1 block in each direction.
+    //Include all chunk sections that contain blocks inside the expanded box.
+    public static WorldSectionBox relevantExpandedBlocksBox(Level world, AABB box) {
+        int minX = SectionPos.blockToSectionCoord(Mth.floor(box.minX) - 1);
+        int minY = SectionPos.blockToSectionCoord(Mth.floor(box.minY) - 1);
+        int minZ = SectionPos.blockToSectionCoord(Mth.floor(box.minZ) - 1);
+        int maxX = SectionPos.blockToSectionCoord(Mth.floor(box.maxX) + 1) + 1;
+        int maxY = SectionPos.blockToSectionCoord(Mth.floor(box.maxY) + 1) + 1;
+        int maxZ = SectionPos.blockToSectionCoord(Mth.floor(box.maxZ) + 1) + 1;
+        return new WorldSectionBox(world, minX, minY, minZ, maxX, maxY, maxZ);
+    }
+    //Like relevant blocks, but not expanded, because fluids never exceed the 1x1x1 volume of a block
+    public static WorldSectionBox relevantFluidBox(Level world, AABB box) {
+        int minX = SectionPos.blockToSectionCoord(Mth.floor(box.minX));
+        int minY = SectionPos.blockToSectionCoord(Mth.floor(box.minY));
+        int minZ = SectionPos.blockToSectionCoord(Mth.floor(box.minZ));
+        int maxX = SectionPos.blockToSectionCoord(Mth.floor(box.maxX)) + 1;
+        int maxY = SectionPos.blockToSectionCoord(Mth.floor(box.maxY)) + 1;
+        int maxZ = SectionPos.blockToSectionCoord(Mth.floor(box.maxZ)) + 1;
+        return new WorldSectionBox(world, minX, minY, minZ, maxX, maxY, maxZ);
+    }
+
+    public int numSections() {
+        return (this.chunkX2 - this.chunkX1) * (this.chunkY2 - this.chunkY1) * (this.chunkZ2 - this.chunkZ1);
+    }
+
+    public boolean matchesRelevantBlocksBox(AABB box) {
+        return SectionPos.blockToSectionCoord(Mth.floor(box.minX) - 1) == this.chunkX1 &&
+                SectionPos.blockToSectionCoord(Mth.floor(box.minY) - 1) == this.chunkY1 &&
+                SectionPos.blockToSectionCoord(Mth.floor(box.minZ) - 1) == this.chunkZ1 &&
+                SectionPos.blockToSectionCoord(Mth.ceil(box.maxX) + 1) + 1 == this.chunkX2 &&
+                SectionPos.blockToSectionCoord(Mth.ceil(box.maxY) + 1) + 1 == this.chunkY2 &&
+                SectionPos.blockToSectionCoord(Mth.ceil(box.maxZ) + 1) + 1 == this.chunkZ2;
+    }
+
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/ChunkAwareEntityIterable.java

@@ -0,0 +1,9 @@
+package net.gensokyoreimagined.nitori.common.world;
+
+//import net.minecraft.world.level.entity.EntityAccess;
+//
+//public interface ChunkAwareEntityIterable<T extends EntityAccess> {
+//    Iterable<T> lithium$IterateEntitiesInTrackedSections();
+//}
+
+//PersistentEntitySectionManager does not work on paper

src/main/java/net/gensokyoreimagined/nitori/common/world/ChunkRandomSource.java

@@ -12,20 +12,17 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.common.world;
 
-import com.destroystokyo.paper.util.maplist.EntityList;
-import io.papermc.paper.world.ChunkEntitySlices;
-import net.gensokyoreimagined.nitori.access.IMixinChunkEntitySlicesAccess;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.gen.Accessor;
+import net.minecraft.core.BlockPos;
 
-@Mixin(ChunkEntitySlices.class)
-public abstract class MixinChunkEntitySlices implements IMixinChunkEntitySlicesAccess {
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Override
-    @Final
-    @Accessor
-    public abstract EntityList getEntities();
+// Taken from Lithium
+// https://github.com/CaffeineMC/lithium-fabric/blob/427dd75ffc922cc1858c1db4b283cc54744567e0/src/main/java/me/jellysquid/mods/lithium/common/world/ChunkRandomSource.java
+
+public interface ChunkRandomSource {
+    /**
+     * Alternative implementation of {@link net.minecraft.server.level.ServerLevel#getBlockRandomPos(int, int, int, int)} which does not allocate
+     * a new {@link BlockPos}.
+     */
+    void nitori$getRandomPosInChunk(int x, int y, int z, int mask, BlockPos.MutableBlockPos out);
 }

src/main/java/net/gensokyoreimagined/nitori/common/world/ChunkView.java

@@ -0,0 +1,10 @@
+package net.gensokyoreimagined.nitori.common.world;
+
+import net.minecraft.world.level.chunk.ChunkAccess;
+import org.jetbrains.annotations.Nullable;
+
+public interface ChunkView {
+
+    @Nullable
+    ChunkAccess lithium$getLoadedChunk(int chunkX, int chunkZ);
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/ClimbingMobCachingSection.java

@@ -0,0 +1,17 @@
+package net.gensokyoreimagined.nitori.common.world;
+
+import net.gensokyoreimagined.nitori.common.entity.pushable.BlockCachingEntity;
+import net.gensokyoreimagined.nitori.common.entity.pushable.EntityPushablePredicate;
+import net.minecraft.util.AbortableIterationConsumer;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.phys.AABB;
+
+import java.util.ArrayList;
+
+public interface ClimbingMobCachingSection {
+    AbortableIterationConsumer.Continuation lithium$collectPushableEntities(Level world, Entity except, AABB box, EntityPushablePredicate<? super Entity> entityPushablePredicate, ArrayList<Entity> entities);
+
+    void lithium$onEntityModifiedCachedBlock(BlockCachingEntity entity, BlockState newBlockState);
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/LithiumData.java

@@ -0,0 +1,55 @@
+package net.gensokyoreimagined.nitori.common.world;
+
+//import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+//import it.unimi.dsi.fastutil.longs.Long2ReferenceOpenHashMap;
+//import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet;
+//import net.gensokyoreimagined.nitori.common.entity.block_tracking.ChunkSectionChangeCallback;
+//import net.gensokyoreimagined.nitori.common.entity.block_tracking.SectionedBlockChangeTracker;
+//import net.gensokyoreimagined.nitori.common.entity.movement_tracker.SectionedEntityMovementTracker;
+//import net.gensokyoreimagined.nitori.common.util.deduplication.LithiumInterner;
+//import net.minecraft.world.entity.ai.navigation.PathNavigation;
+//import net.minecraft.world.item.ItemStack;
+//import net.minecraft.core.registries.Registries;
+//import net.minecraft.world.entity.raid.Raid;
+//import net.minecraft.world.level.Level;
+//import net.minecraft.world.level.gameevent.GameEventDispatcher;
+//import net.minecraft.world.level.gameevent.GameEventListenerRegistry;
+//
+//public interface LithiumData {
+//
+//    record Data(
+//            // Map of chunk position -> y section -> game event dispatcher
+//            // This should be faster than the chunk lookup, since there are usually a lot more chunks than
+//            // chunk with game event dispatchers (we only initialize them when non-empty set of listeners)
+//            // All Int2ObjectMap objects are also stored in a field of the corresponding WorldChunk.
+//            Long2ReferenceOpenHashMap<Int2ObjectMap<GameEventDispatcher>> gameEventDispatchersByChunk,
+//
+//            // Cached ominous banner, must not be mutated.
+//            ItemStack ominousBanner,
+//
+//            // Set of active mob navigations (active = have a path)
+//            ReferenceOpenHashSet<PathNavigation> activeNavigations,
+//
+//            // Block change tracker deduplication
+//            LithiumInterner<SectionedBlockChangeTracker> blockChangeTrackers,
+//
+//            // Entity movement tracker deduplication
+//            LithiumInterner<SectionedEntityMovementTracker<?, ?>> entityMovementTrackers,
+//
+//            // Block ChunkSection listeners
+//            Long2ReferenceOpenHashMap<ChunkSectionChangeCallback> chunkSectionChangeCallbacks
+//    ) {
+//        public Data(Level world) {
+//            this(
+//                    new Long2ReferenceOpenHashMap<>(),
+//                    world.registryAccess().lookup(Registries.BANNER_PATTERN).map(Raid::getLeaderBannerInstance).orElse(null),
+//                    new ReferenceOpenHashSet<>(),
+//                    new LithiumInterner<>(),
+//                    new LithiumInterner<>(),
+//                    new Long2ReferenceOpenHashMap<>()
+//            );
+//        }
+//    }
+//
+//    LithiumData.Data lithium$getData();
+//}

src/main/java/net/gensokyoreimagined/nitori/common/world/ServerWorldExtended.java

@@ -0,0 +1,9 @@
+package net.gensokyoreimagined.nitori.common.world;
+
+import net.minecraft.world.entity.Mob;
+
+public interface ServerWorldExtended {
+    void lithium$setNavigationActive(Mob mobEntity);
+
+    void lithium$setNavigationInactive(Mob mobEntity);
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/WorldHelper.java

@@ -0,0 +1,120 @@
+package net.gensokyoreimagined.nitori.common.world;
+
+import net.gensokyoreimagined.nitori.common.entity.EntityClassGroup;
+import net.gensokyoreimagined.nitori.common.entity.pushable.EntityPushablePredicate;
+import net.gensokyoreimagined.nitori.mixin.util.accessors.EntityTrackingSectionAccessor;
+import net.gensokyoreimagined.nitori.common.world.chunk.ClassGroupFilterableList;
+import net.minecraft.core.BlockPos;
+import net.minecraft.util.ClassInstanceMultiMap;
+import net.minecraft.util.AbortableIterationConsumer;
+import net.minecraft.world.phys.AABB;
+import net.minecraft.world.level.EntityGetter;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.entity.EntitySectionStorage;
+import org.jetbrains.annotations.Nullable;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Predicate;
+
+public class WorldHelper {
+    public static final boolean CUSTOM_TYPE_FILTERABLE_LIST_DISABLED = !ClassGroupFilterableList.class.isAssignableFrom(ClassInstanceMultiMap.class);
+
+    /**
+     * Partial [VanillaCopy]
+     * The returned entity iterator is only used for collision interactions. As most entities do not collide with other
+     * entities (cramming is different), getting them is not necessary. This is why we only get entities when they override
+     * {@link Entity#canBeCollidedWith()} if the reference entity does not override {@link Entity#canCollideWith(Entity)}.
+     * Note that the returned iterator contains entities that override these methods. This does not mean that these methods
+     * always return true.
+     *
+     * @param entityView      the world
+     * @param box             the box the entities have to collide with
+     * @param collidingEntity the entity that is searching for the colliding entities
+     * @return iterator of entities with collision boxes
+     */
+    public static List<Entity> getEntitiesForCollision(EntityGetter entityView, AABB box, Entity collidingEntity) {
+        if (!CUSTOM_TYPE_FILTERABLE_LIST_DISABLED && entityView instanceof Level world && (collidingEntity == null || !EntityClassGroup.CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE.contains(collidingEntity.getClass()))) {
+            EntitySectionStorage<Entity> cache = getEntityCacheOrNull(world);
+            if (cache != null) {
+                world.getProfiler().incrementCounter("getEntities");
+                return getEntitiesOfClassGroup(cache, collidingEntity, EntityClassGroup.NoDragonClassGroup.BOAT_SHULKER_LIKE_COLLISION, box);
+            }
+        }
+        //use vanilla code in case the shortcut is not applicable
+        // due to the reference entity implementing special collision or the mixin being disabled in the config
+        return entityView.getEntities(collidingEntity, box);
+    }
+
+    public static List<Entity> getOtherEntitiesForCollision(EntityGetter entityView, AABB box, @Nullable Entity collidingEntity, Predicate<? super Entity> entityPredicate) {
+        if (!CUSTOM_TYPE_FILTERABLE_LIST_DISABLED && entityView instanceof Level world) {
+            if (collidingEntity == null || !EntityClassGroup.CUSTOM_COLLIDE_LIKE_MINECART_BOAT_WINDCHARGE.contains(collidingEntity.getClass())) {
+                EntitySectionStorage<Entity> cache = getEntityCacheOrNull(world);
+                if (cache != null) {
+                    world.getProfiler().incrementCounter("getEntities");
+                    return getEntitiesOfClassGroup(cache, collidingEntity, EntityClassGroup.NoDragonClassGroup.BOAT_SHULKER_LIKE_COLLISION, box);
+                }
+            }
+        }
+        //use vanilla code in case the shortcut is not applicable
+        // due to the reference entity implementing special collision or the mixin being disabled in the config
+        return entityView.getEntities(collidingEntity, box, entityPredicate);
+    }
+
+
+    //Requires util.accessors
+    public static EntitySectionStorage<Entity> getEntityCacheOrNull(Level world) {
+        // Does not work on Paper...
+//        if (world instanceof ServerWorldAccessor) {
+//            //noinspection unchecked
+//            return ((ServerEntityManagerAccessor<Entity>) ((ServerWorldAccessor) world).getEntityManager()).getSectionStorage();
+//        }
+        return null;
+    }
+
+    public static List<Entity> getEntitiesOfClassGroup(EntitySectionStorage<Entity> cache, Entity collidingEntity, EntityClassGroup.NoDragonClassGroup entityClassGroup, AABB box) {
+        ArrayList<Entity> entities = new ArrayList<>();
+        cache.forEachAccessibleNonEmptySection(box, section -> {
+            //noinspection unchecked
+            ClassInstanceMultiMap<Entity> allEntities = ((EntityTrackingSectionAccessor<Entity>) section).getStorage();
+            //noinspection unchecked
+            Collection<Entity> entitiesOfType = ((ClassGroupFilterableList<Entity>) allEntities).lithium$getAllOfGroupType(entityClassGroup);
+            if (!entitiesOfType.isEmpty()) {
+                for (Entity entity : entitiesOfType) {
+                    if (entity.getBoundingBox().intersects(box) && !entity.isSpectator() && entity != collidingEntity) {
+                        //skip the dragon piece check without issues by only allowing EntityClassGroup.NoDragonClassGroup as type
+                        entities.add(entity);
+                    }
+                }
+            }
+            return AbortableIterationConsumer.Continuation.CONTINUE;
+        });
+        return entities;
+    }
+
+    public static List<Entity> getPushableEntities(Level world, EntitySectionStorage<Entity> cache, Entity except, AABB box, EntityPushablePredicate<? super Entity> entityPushablePredicate) {
+        ArrayList<Entity> entities = new ArrayList<>();
+        cache.forEachAccessibleNonEmptySection(box, section -> ((ClimbingMobCachingSection) section).lithium$collectPushableEntities(world, except, box, entityPushablePredicate, entities));
+        return entities;
+    }
+
+    public static boolean areNeighborsWithinSameChunk(BlockPos pos) {
+        int localX = pos.getX() & 15;
+        int localZ = pos.getZ() & 15;
+
+        return localX > 0 && localZ > 0 && localX < 15 && localZ < 15;
+    }
+
+    public static boolean areNeighborsWithinSameChunkSection(int x, int y, int z) {
+        int localX = x & 15;
+        int localY = y & 15;
+        int localZ = z & 15;
+
+        return localX > 0 && localY > 0 && localZ > 0 && localX < 15 && localY < 15 && localZ < 15;
+    }
+
+    public static boolean arePosWithinSameChunk(BlockPos pos1, BlockPos pos2) {
+        return pos1.getX() >> 4 == pos2.getX() >> 4 && pos1.getZ() >> 4 == pos2.getZ() >> 4;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/blockentity/BlockEntityGetter.java

@@ -12,16 +12,11 @@
 //
 // 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 net.gensokyoreimagined.nitori.access;
+package net.gensokyoreimagined.nitori.common.world.blockentity;
 
-import com.destroystokyo.paper.util.misc.PooledLinkedHashSets;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.core.BlockPos;
 
-public interface IMixinChunkMap_TrackedEntityAccess {
-    @SuppressWarnings("EmptyMethod")
-    Entity getEntity();
-
-    @SuppressWarnings("EmptyMethod")
-    void callUpdatePlayers(PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newTrackerCandidates);
-}
+public interface BlockEntityGetter {
+    BlockEntity lithium$getLoadedExistingBlockEntity(BlockPos pos);
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/blockentity/SupportCache.java

@@ -0,0 +1,5 @@
+package net.gensokyoreimagined.nitori.common.world.blockentity;
+
+public interface SupportCache {
+    boolean lithium$isSupported();
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/blockview/SingleBlockBlockView.java

@@ -0,0 +1,142 @@
+package net.gensokyoreimagined.nitori.common.world.blockview;
+
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.phys.shapes.CollisionContext;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.material.FluidState;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.phys.AABB;
+import net.minecraft.world.phys.Vec3;
+import net.minecraft.world.phys.shapes.VoxelShape;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.CollisionGetter;
+import net.minecraft.world.level.border.WorldBorder;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+import java.util.Optional;
+
+public record SingleBlockBlockView(BlockState state, BlockPos pos) implements BlockGetter, CollisionGetter {
+    public static SingleBlockBlockView of(BlockState blockState, BlockPos blockPos) {
+        return new SingleBlockBlockView(blockState, blockPos.immutable());
+    }
+
+    @Override
+    public BlockState getBlockState(BlockPos pos) {
+        if (pos.equals(this.pos())) {
+            return this.state();
+        } else {
+            throw SingleBlockViewException.INSTANCE;
+        }
+    }
+
+    @Override
+    public FluidState getFluidState(BlockPos pos) {
+        if (pos.equals(this.pos())) {
+            return this.state().getFluidState();
+        } else {
+            throw SingleBlockViewException.INSTANCE;
+        }
+    }
+
+    @Nullable
+    @Override
+    public BlockEntity getBlockEntity(BlockPos pos) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public int getHeight() {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public int getMinBuildHeight() {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public WorldBorder getWorldBorder() {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Nullable
+    @Override
+    public BlockGetter getChunkForCollisions(int chunkX, int chunkZ) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public boolean isUnobstructed(@Nullable Entity except, VoxelShape shape) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public boolean isUnobstructed(BlockState state, BlockPos pos, CollisionContext context) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public boolean isUnobstructed(Entity entity) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public boolean noCollision(@Nullable Entity entity, AABB box) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public List<VoxelShape> getEntityCollisions(@Nullable Entity entity, AABB box) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public Iterable<VoxelShape> getCollisions(@Nullable Entity entity, AABB box) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public Iterable<VoxelShape> getBlockCollisions(@Nullable Entity entity, AABB box) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public boolean collidesWithSuffocatingBlock(@Nullable Entity entity, AABB box) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @Override
+    public Optional<Vec3> findFreePosition(@Nullable Entity entity, VoxelShape shape, Vec3 target, double x, double y, double z) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    public static class SingleBlockViewException extends RuntimeException {
+
+        public static final SingleBlockViewException INSTANCE = new SingleBlockViewException();
+
+        private SingleBlockViewException() {
+            this.setStackTrace(new StackTraceElement[0]);
+        }
+
+        @Override
+        public synchronized Throwable fillInStackTrace() {
+            this.setStackTrace(new StackTraceElement[0]);
+            return this;
+        }
+    }
+
+    @javax.annotation.Nullable
+    @Override
+    public BlockState getBlockStateIfLoaded(@NotNull BlockPos block) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+
+    @javax.annotation.Nullable
+    @Override
+    public FluidState getFluidIfLoaded(@NotNull BlockPos block) {
+        throw SingleBlockViewException.INSTANCE;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/chunk/ChunkStatusTracker.java

@@ -0,0 +1,26 @@
+package net.gensokyoreimagined.nitori.common.world.chunk;
+
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.ChunkPos;
+
+import java.util.ArrayList;
+import java.util.function.BiConsumer;
+
+public class ChunkStatusTracker {
+
+    //Add other callback types in the future when needed
+    private static final ArrayList<BiConsumer<ServerLevel, ChunkPos>> UNLOAD_CALLBACKS = new ArrayList<>();
+    public static void onChunkStatusChange(ServerLevel serverWorld, ChunkPos pos, FullChunkStatus levelType) {
+        boolean loaded = levelType.isOrAfter(FullChunkStatus.FULL);
+        if (!loaded) {
+            for (int i = 0; i < UNLOAD_CALLBACKS.size(); i++) {
+                UNLOAD_CALLBACKS.get(i).accept(serverWorld, pos);
+            }
+        }
+    }
+
+    public static void registerUnloadCallback(BiConsumer<ServerLevel, ChunkPos> callback) {
+        UNLOAD_CALLBACKS.add(callback);
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/chunk/ClassGroupFilterableList.java

@@ -0,0 +1,8 @@
+package net.gensokyoreimagined.nitori.common.world.chunk;
+
+import net.gensokyoreimagined.nitori.common.entity.EntityClassGroup;
+import java.util.Collection;
+
+public interface ClassGroupFilterableList<T> {
+    Collection<T> lithium$getAllOfGroupType(EntityClassGroup type);
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/chunk/LithiumHashPalette.java

@@ -0,0 +1,199 @@
+package net.gensokyoreimagined.nitori.common.world.chunk;
+
+//import com.google.common.collect.ImmutableList;
+//import it.unimi.dsi.fastutil.HashCommon;
+//import it.unimi.dsi.fastutil.objects.Reference2IntMap;
+//import it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap;
+//import net.gensokyoreimagined.nitori.mixin.removed.palette.PaletteResizeAccessor;
+//import net.minecraft.network.FriendlyByteBuf;
+//import net.minecraft.network.VarInt;
+//import net.minecraft.core.IdMap;
+//import net.minecraft.world.level.chunk.MissingPaletteEntryException;
+//import net.minecraft.world.level.chunk.Palette;
+//import org.jetbrains.annotations.NotNull;
+//
+//import java.util.Arrays;
+//import java.util.List;
+//import java.util.function.Predicate;
+//
+//import static it.unimi.dsi.fastutil.Hash.FAST_LOAD_FACTOR;
+//
+///**
+//* Generally provides better performance over the vanilla {@link net.minecraft.world.level.chunk.HashMapPalette} when calling
+//* {@link LithiumHashPalette#idFor(Object)} through using a faster backing map and reducing pointer chasing.
+//*/
+//public class LithiumHashPalette<T> implements Palette<T> {
+//   private static final int ABSENT_VALUE = -1;
+//
+//   private final IdMap<T> idList;
+//   // private final PaletteResize<T> resizeHandler;
+//   private final PaletteResizeAccessor<T> resizeHandler;
+//   private final int indexBits;
+//
+//   private final Reference2IntMap<T> table;
+//   private T[] entries;
+//   private int size = 0;
+//
+//   public LithiumHashPalette(IdMap<T> idList, PaletteResizeAccessor<T> resizeHandler, int indexBits, T[] entries, Reference2IntMap<T> table, int size) {
+//       this.idList = idList;
+//       this.resizeHandler = resizeHandler;
+//       this.indexBits = indexBits;
+//       this.entries = entries;
+//       this.table = table;
+//       this.size = size;
+//   }
+//
+//   public LithiumHashPalette(IdMap<T> idList, int bits, PaletteResizeAccessor<T> resizeHandler, List<T> list) {
+//       this(idList, bits, resizeHandler);
+//
+//       for (T t : list) {
+//           this.addEntry(t);
+//       }
+//   }
+//
+//   @SuppressWarnings("unchecked")
+//   public LithiumHashPalette(IdMap<T> idList, int bits, PaletteResizeAccessor<T> resizeHandler) {
+//       this.idList = idList;
+//       this.indexBits = bits;
+//       this.resizeHandler = resizeHandler;
+//
+//       int capacity = 1 << bits;
+//
+//       this.entries = (T[]) new Object[capacity];
+//       this.table = new Reference2IntOpenHashMap<>(capacity, FAST_LOAD_FACTOR);
+//       this.table.defaultReturnValue(ABSENT_VALUE);
+//   }
+//
+//   @Override
+//   public int idFor(T obj) {
+//       int id = this.table.getInt(obj);
+//
+//       if (id == ABSENT_VALUE) {
+//           id = this.computeEntry(obj);
+//       }
+//
+//       return id;
+//   }
+//
+//   @Override
+//   public boolean maybeHas(Predicate<T> predicate) {
+//       for (int i = 0; i < this.size; ++i) {
+//           if (predicate.test(this.entries[i])) {
+//               return true;
+//           }
+//       }
+//
+//       return false;
+//   }
+//
+//   private int computeEntry(T obj) {
+//       int id = this.addEntry(obj);
+//
+//       if (id >= 1 << this.indexBits) {
+//           if (this.resizeHandler == null) {
+//               throw new IllegalStateException("Cannot grow");
+//           } else {
+//               id = this.resizeHandler.callOnResize(this.indexBits + 1, obj);
+//           }
+//       }
+//
+//       return id;
+//   }
+//
+//   private int addEntry(T obj) {
+//       int nextId = this.size;
+//
+//       if (nextId >= this.entries.length) {
+//           this.resize(this.size);
+//       }
+//
+//       this.table.put(obj, nextId);
+//       this.entries[nextId] = obj;
+//
+//       this.size++;
+//
+//       return nextId;
+//   }
+//
+//   private void resize(int neededCapacity) {
+//       this.entries = Arrays.copyOf(this.entries, HashCommon.nextPowerOfTwo(neededCapacity + 1));
+//   }
+//
+//   @Override
+//   public @NotNull T valueFor(int id) {
+//       T[] entries = this.entries;
+//
+//       T entry = null;
+//       if (id >= 0 && id < entries.length) {
+//           entry = entries[id];
+//       }
+//
+//       if (entry != null) {
+//           return entry;
+//       } else {
+//           throw new MissingPaletteEntryException(id);
+//       }
+//   }
+//
+//   @Override
+//   public void read(FriendlyByteBuf buf) {
+//       this.clear();
+//
+//       int entryCount = buf.readVarInt();
+//
+//       for (int i = 0; i < entryCount; ++i) {
+//           this.addEntry(this.idList.byId(buf.readVarInt()));
+//       }
+//   }
+//
+//   @Override
+//   public void write(FriendlyByteBuf buf) {
+//       int size = this.size;
+//       buf.writeVarInt(size);
+//
+//       for (int i = 0; i < size; ++i) {
+//           buf.writeVarInt(this.idList.getId(this.valueFor(i)));
+//       }
+//   }
+//
+//   @Override
+//   public int getSerializedSize() {
+//       int size = VarInt.getByteSize(this.size);
+//
+//       for (int i = 0; i < this.size; ++i) {
+//           size += VarInt.getByteSize(this.idList.getId(this.valueFor(i)));
+//       }
+//
+//       return size;
+//   }
+//
+//   @Override
+//   public int getSize() {
+//       return this.size;
+//   }
+//
+//   @Override
+//   public Palette<T> copy() {
+//       return new LithiumHashPalette<>(this.idList, this.resizeHandler, this.indexBits, this.entries.clone(), new Reference2IntOpenHashMap<>(this.table), this.size);
+//   }
+//
+//   private void clear() {
+//       Arrays.fill(this.entries, null);
+//       this.table.clear();
+//       this.size = 0;
+//   }
+//
+//   public List<T> getElements() {
+//       ImmutableList.Builder<T> builder = new ImmutableList.Builder<>();
+//       for (T entry : this.entries) {
+//           if (entry != null) {
+//               builder.add(entry);
+//           }
+//       }
+//       return builder.build();
+//   }
+//
+//   public static <A> Palette<A> create(int bits, IdMap<A> idList, PaletteResizeAccessor<A> listener, List<A> list) {
+//       return new LithiumHashPalette<>(idList, bits, listener, list);
+//   }
+//}

src/main/java/net/gensokyoreimagined/nitori/common/world/interests/PointOfInterestSetExtended.java

@@ -0,0 +1,14 @@
+package net.gensokyoreimagined.nitori.common.world.interests;
+
+import net.minecraft.core.Holder;
+import net.minecraft.world.entity.ai.village.poi.PoiRecord;
+import net.minecraft.world.entity.ai.village.poi.PoiManager;
+import net.minecraft.world.entity.ai.village.poi.PoiType;
+
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+
+public interface PointOfInterestSetExtended {
+    void lithium$collectMatchingPoints(Predicate<Holder<PoiType>> type, PoiManager.Occupancy status,
+                                       Consumer<PoiRecord> consumer);
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/interests/iterator/SinglePointOfInterestTypeFilter.java

@@ -0,0 +1,19 @@
+package net.gensokyoreimagined.nitori.common.world.interests.iterator;
+
+import net.minecraft.core.Holder;
+import net.minecraft.world.entity.ai.village.poi.PoiType;
+
+import java.util.function.Predicate;
+
+public record SinglePointOfInterestTypeFilter(
+        Holder<PoiType> type) implements Predicate<Holder<PoiType>> {
+
+    @Override
+    public boolean test(Holder<PoiType> other) {
+        return this.type == other;
+    }
+
+    public Holder<PoiType> getType() {
+        return this.type;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/interests/types/PointOfInterestTypeHelper.java

@@ -0,0 +1,24 @@
+package net.gensokyoreimagined.nitori.common.world.interests.types;
+
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+
+import java.util.Set;
+import java.util.function.Predicate;
+
+public class PointOfInterestTypeHelper {
+    private static Predicate<BlockState> POI_BLOCKSTATE_PREDICATE;
+
+
+    public static void init(Set<BlockState> types) {
+        if (POI_BLOCKSTATE_PREDICATE != null) {
+            throw new IllegalStateException("Already initialized");
+        }
+
+        POI_BLOCKSTATE_PREDICATE = types::contains;
+    }
+
+    public static boolean mayHavePoi(LevelChunkSection chunkSection) {
+        return chunkSection.maybeHas(POI_BLOCKSTATE_PREDICATE);
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/common/world/scheduler/OrderedTickQueue.java

@@ -0,0 +1,192 @@
+package net.gensokyoreimagined.nitori.common.world.scheduler;
+
+// ChunkTickSchedulerMixin needs this
+
+
+
+//import it.unimi.dsi.fastutil.HashCommon;
+//import net.minecraft.world.ticks.ScheduledTick;
+//
+//import java.util.*;
+//
+//public class OrderedTickQueue<T> extends AbstractQueue<ScheduledTick<T>> {
+//    private static final int INITIAL_CAPACITY = 16;
+//    private static final Comparator<ScheduledTick<?>> COMPARATOR = Comparator.comparingLong(ScheduledTick::subTickOrder);
+//
+//    private ScheduledTick<T>[] arr;
+//
+//    private int lastIndexExclusive;
+//    private int firstIndex;
+//
+//    private long currentMaxSubTickOrder = Long.MIN_VALUE;
+//    private boolean isSorted;
+//    private ScheduledTick<T> unsortedPeekResult;
+//
+//    @SuppressWarnings("unchecked")
+//    public OrderedTickQueue(int capacity) {
+//        this.arr = (ScheduledTick<T>[]) new ScheduledTick[capacity];
+//        this.lastIndexExclusive = 0;
+//        this.isSorted = true;
+//        this.unsortedPeekResult = null;
+//        this.firstIndex = 0;
+//    }
+//
+//    public OrderedTickQueue() {
+//        this(INITIAL_CAPACITY);
+//    }
+//
+//    @Override
+//    public void clear() {
+//        Arrays.fill(this.arr, null);
+//        this.lastIndexExclusive = 0;
+//        this.firstIndex = 0;
+//        this.currentMaxSubTickOrder = Long.MIN_VALUE;
+//        this.isSorted = true;
+//        this.unsortedPeekResult = null;
+//    }
+//
+//    @Override
+//    public Iterator<ScheduledTick<T>> iterator() {
+//        if (this.isEmpty()) {
+//            return Collections.emptyIterator();
+//        }
+//        this.sort();
+//        return new Iterator<>() {
+//            int nextIndex = OrderedTickQueue.this.firstIndex;
+//
+//            @Override
+//            public boolean hasNext() {
+//                return this.nextIndex < OrderedTickQueue.this.lastIndexExclusive;
+//            }
+//
+//            @Override
+//            public ScheduledTick<T> next() {
+//                return OrderedTickQueue.this.arr[this.nextIndex++];
+//            }
+//        };
+//    }
+//
+//    @Override
+//    public ScheduledTick<T> poll() {
+//        if (this.isEmpty()) {
+//            return null;
+//        }
+//        if (!this.isSorted) {
+//            this.sort();
+//        }
+//        ScheduledTick<T> nextTick;
+//        int polledIndex = this.firstIndex++;
+//        ScheduledTick<T>[] ticks = this.arr;
+//        nextTick = ticks[polledIndex];
+//        ticks[polledIndex] = null;
+//        return nextTick;
+//    }
+//
+//    @Override
+//    public ScheduledTick<T> peek() {
+//        if (!this.isSorted) {
+//            return this.unsortedPeekResult;
+//        } else if (this.lastIndexExclusive > this.firstIndex) {
+//            return this.getTickAtIndex(this.firstIndex);
+//        }
+//        return null;
+//    }
+//
+//    public boolean offer(ScheduledTick<T> tick) {
+//        if (this.lastIndexExclusive >= this.arr.length) {
+//            //todo remove consumed elements first
+//            this.arr = copyArray(this.arr, HashCommon.nextPowerOfTwo(this.arr.length + 1));
+//        }
+//        if (tick.subTickOrder() <= this.currentMaxSubTickOrder) {
+//            //Set to unsorted instead of slowing down the insertion
+//            //This is rare but may happen in bulk
+//            //Sorting later needs O(n*log(n)) time, but it only needs to happen when unordered insertion needs to happen
+//            //Therefore it is better than n times log(n) time of the PriorityQueue that happens on ordered insertion too
+//            ScheduledTick<T> firstTick = this.isSorted ? this.size() > 0 ? this.arr[this.firstIndex] : null : this.unsortedPeekResult;
+//            this.isSorted = false;
+//            this.unsortedPeekResult = firstTick == null || tick.subTickOrder() < firstTick.subTickOrder() ? tick : firstTick;
+//        } else {
+//            this.currentMaxSubTickOrder = tick.subTickOrder();
+//        }
+//        this.arr[this.lastIndexExclusive++] = tick;
+//        return true;
+//    }
+//
+//    public int size() {
+//        return this.lastIndexExclusive - this.firstIndex;
+//    }
+//
+//    private void handleCompaction(int size) {
+//        // Only compact the array if it is less than 50% filled
+//        if (this.arr.length > INITIAL_CAPACITY && size < this.arr.length / 2) {
+//            this.arr = copyArray(this.arr, size);
+//        } else {
+//            // Fill the unused array elements with nulls to release our references to the elements in it
+//            Arrays.fill(this.arr, size, this.arr.length, null);
+//        }
+//
+//        this.firstIndex = 0;
+//        this.lastIndexExclusive = size;
+//
+//        if (size == 0 || !this.isSorted) {
+//            this.currentMaxSubTickOrder = Long.MIN_VALUE;
+//        } else {
+//            ScheduledTick<T> tick = this.arr[size - 1];
+//            this.currentMaxSubTickOrder = tick == null ? Long.MIN_VALUE : tick.subTickOrder();
+//        }
+//    }
+//
+//    public void sort() {
+//        if (this.isSorted) {
+//            return;
+//        }
+//        this.removeNullsAndConsumed();
+//        Arrays.sort(this.arr, this.firstIndex, this.lastIndexExclusive, COMPARATOR);
+//        this.isSorted = true;
+//        this.unsortedPeekResult = null;
+//    }
+//
+//    public void removeNullsAndConsumed() {
+//        int src = this.firstIndex;
+//        int dst = 0;
+//        while (src < this.lastIndexExclusive) {
+//            ScheduledTick<T> ScheduledTick = this.arr[src];
+//            if (ScheduledTick != null) {
+//                this.arr[dst] = ScheduledTick;
+//                dst++;
+//            }
+//            src++;
+//        }
+//        this.handleCompaction(dst);
+//    }
+//
+//    public ScheduledTick<T> getTickAtIndex(int index) {
+//        if (!this.isSorted) {
+//            throw new IllegalStateException("Unexpected access on unsorted queue!");
+//        }
+//        return this.arr[index];
+//    }
+//
+//    public void setTickAtIndex(int index, ScheduledTick<T> tick) {
+//        if (!this.isSorted) {
+//            throw new IllegalStateException("Unexpected access on unsorted queue!");
+//        }
+//        this.arr[index] = tick;
+//    }
+//
+//    @SuppressWarnings("unchecked")
+//    private static <T> ScheduledTick<T>[] copyArray(ScheduledTick<T>[] src, int size) {
+//        final ScheduledTick<T>[] copy = new ScheduledTick[Math.max(INITIAL_CAPACITY, size)];
+//
+//        if (size != 0) {
+//            System.arraycopy(src, 0, copy, 0, Math.min(src.length, size));
+//        }
+//
+//        return copy;
+//    }
+//
+//    @Override
+//    public boolean isEmpty() {
+//        return this.lastIndexExclusive <= this.firstIndex;
+//    }
+//}

src/main/java/net/gensokyoreimagined/nitori/compatibility/BasePluginCompatibility.java

@@ -22,7 +22,6 @@ import javax.annotation.Nullable;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.CompletionException;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.BooleanSupplier;
 
 /**

src/main/java/net/gensokyoreimagined/nitori/compatibility/PluginCompatibilityCitizens.java

@@ -24,9 +24,9 @@ import java.util.Map;
 public final class PluginCompatibilityCitizens extends BasePluginCompatibility {
     private static final String CITIZENS_PLUGIN_NAME = "Citizens";
 
-    private static final ClassReflectionReferenceResolver citizensPluginCitizensEntityTrackerClassResolver = new ClassReflectionReferenceResolver("net.citizensnpcs.nms.v1_20_R3.util.CitizensEntityTracker");
+    private static final ClassReflectionReferenceResolver citizensPluginCitizensEntityTrackerClassResolver = new ClassReflectionReferenceResolver("net.citizensnpcs.nms.v1_20_R4.util.CitizensEntityTracker");
 
-    private static final ClassReflectionReferenceResolver citizensPluginEntityHumanNPCClassResolver = new ClassReflectionReferenceResolver("net.citizensnpcs.nms.v1_20_R3.entity.EntityHumanNPC");
+    private static final ClassReflectionReferenceResolver citizensPluginEntityHumanNPCClassResolver = new ClassReflectionReferenceResolver("net.citizensnpcs.nms.v1_20_R4.entity.EntityHumanNPC");
 
     PluginCompatibilityCitizens() {
         super(new String[]{CITIZENS_PLUGIN_NAME});

src/main/java/net/gensokyoreimagined/nitori/core/ChunkMapMixin.java

@@ -1,170 +0,0 @@
-// Nitori Copyright (C) 2024 Gensokyo Reimagined
-//
-// 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 net.gensokyoreimagined.nitori.core;
-
-import com.destroystokyo.paper.util.misc.PooledLinkedHashSets;
-import it.unimi.dsi.fastutil.ints.Int2ObjectLinkedOpenHashMap;
-import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
-import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet;
-import it.unimi.dsi.fastutil.objects.ReferenceSets;
-//import net.gensokyoreimagined.nitori.config.NitoriConfig;
-import net.gensokyoreimagined.nitori.access.IMixinChunkMapAccess;
-import net.gensokyoreimagined.nitori.access.IMixinChunkMap_TrackedEntityAccess;
-import net.gensokyoreimagined.nitori.compatibility.PluginCompatibilityRegistry;
-import net.gensokyoreimagined.nitori.tracker.MultithreadedTracker;
-import net.minecraft.server.level.ChunkMap;
-import net.minecraft.server.level.ServerEntity;
-import net.minecraft.server.level.ServerLevel;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.server.network.ServerPlayerConnection;
-import net.minecraft.world.entity.Entity;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Mutable;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.Unique;
-import org.spongepowered.asm.mixin.gen.Accessor;
-import org.spongepowered.asm.mixin.gen.Invoker;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.Redirect;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-
-import java.util.Set;
-import java.util.concurrent.ConcurrentLinkedQueue;
-import javax.annotation.Nullable;
-
-@Mixin(ChunkMap.class)
-public class ChunkMapMixin implements IMixinChunkMapAccess {
-
-    @Mutable
-    @Shadow @Final public Int2ObjectMap<ChunkMap.TrackedEntity> entityMap;
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Final
-    @Shadow
-    public ServerLevel level;
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Unique
-    private @Nullable MultithreadedTracker gensouHacks$multithreadedTracker;
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Final
-    @Unique
-    private final ConcurrentLinkedQueue<Runnable> gensouHacks$trackerMainThreadTasks = new ConcurrentLinkedQueue<>();
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Unique
-    private boolean gensouHacks$tracking = false;
-
-    @Inject(method = "<init>", at = @At("RETURN"))
-    private void reassignEntityTrackers(CallbackInfo ci) {
-        this.entityMap = new Int2ObjectLinkedOpenHashMap<>();
-    }
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Override
-    @Unique
-    public void gensouHacks$runOnTrackerMainThread(final Runnable runnable) {
-        if (this.gensouHacks$tracking) {
-            this.gensouHacks$trackerMainThreadTasks.add(runnable);
-        } else {
-            runnable.run();
-        }
-    }
-
-    @Inject(method = "processTrackQueue", at = @At("HEAD"), cancellable = true)
-    private void atProcessTrackQueueHead(CallbackInfo callbackInfo) {
-        // Implementation of 0107-Multithreaded-Tracker.patch
-        //TODO: Restore config condition
-        //if (NitoriConfig.enableAsyncEntityTracker) {
-            if (this.gensouHacks$multithreadedTracker == null) {
-                this.gensouHacks$multithreadedTracker = new MultithreadedTracker(this.level.chunkSource.entityTickingChunks, this.gensouHacks$trackerMainThreadTasks);
-            }
-
-            this.gensouHacks$tracking = true;
-            try {
-                this.gensouHacks$multithreadedTracker.tick();
-            } finally {
-                this.gensouHacks$tracking = false;
-            }
-            callbackInfo.cancel();
-        //}
-        // Mirai end
-    }
-
-    @Mixin(ChunkMap.TrackedEntity.class)
-    public static abstract class TrackedEntity implements IMixinChunkMap_TrackedEntityAccess {
-        // Implementation of 0107-Multithreaded-Tracker.patch
-        @Override
-        @Final
-        @Accessor
-        public abstract Entity getEntity(); // Mirai -> public
-
-        @Final
-        @Mutable
-        @Shadow
-        public Set<ServerPlayerConnection> seenBy;
-
-        @Shadow
-        public abstract void updatePlayer(ServerPlayer player);
-
-        @Inject(method = "<init>", at = @At("RETURN"))
-        private void reassignSeenBy(CallbackInfo ci) {
-            // Implementation of 0107-Multithreaded-Tracker.patch
-            this.seenBy = ReferenceSets.synchronize(new ReferenceOpenHashSet<>()); // Mirai - sync
-        }
-
-        // Implementation of 0107-Multithreaded-Tracker.patch
-        @Override
-        @Final
-        @Invoker
-        public abstract void callUpdatePlayers(PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newTrackerCandidates); // Mirai -> public
-
-        @Redirect(method = "updatePlayers(Lcom/destroystokyo/paper/util/misc/PooledLinkedHashSets$PooledObjectLinkedOpenHashSet;)V", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/level/ChunkMap$TrackedEntity;updatePlayer(Lnet/minecraft/server/level/ServerPlayer;)V"))
-        private void handleCitizensPluginTracking(ChunkMap.TrackedEntity self, ServerPlayer serverPlayer) {
-            // Nitori - Citizens tracker must run on the main thread to avoid cyclic wait
-            if (PluginCompatibilityRegistry.CITIZENS.shouldRedirectToMainThread(self, serverPlayer)) {
-                ((IMixinChunkMapAccess) (Object) ((ServerLevel) serverPlayer.level()).chunkSource.chunkMap).gensouHacks$runOnTrackerMainThread(() ->
-                    this.updatePlayer(serverPlayer)
-                );
-            } else {
-                this.updatePlayer(serverPlayer);
-            }
-        }
-
-        // Implementation of 0107-Multithreaded-Tracker.patch
-        @SuppressWarnings("EmptyMethod")
-        @Redirect(method = "removePlayer", at = @At(value = "INVOKE", target = "Lorg/spigotmc/AsyncCatcher;catchOp(Ljava/lang/String;)V"))
-        private void skipSpigotAsyncPlayerTrackerClear(String reason) {} // Mirai - we can remove async too
-
-        // Implementation of 0107-Multithreaded-Tracker.patch
-        @SuppressWarnings("EmptyMethod")
-        @Redirect(method = "updatePlayer", at = @At(value = "INVOKE", target = "Lorg/spigotmc/AsyncCatcher;catchOp(Ljava/lang/String;)V"))
-        private void skipSpigotAsyncPlayerTrackerUpdate(String reason) {} // Mirai - we can update async
-
-        @Redirect(method = "updatePlayer", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/level/ServerEntity;addPairing(Lnet/minecraft/server/level/ServerPlayer;)V"))
-        private void handleTrainCartsPluginAddPairing(ServerEntity self, ServerPlayer serverPlayer) {
-            if (PluginCompatibilityRegistry.TRAIN_CARTS.shouldRedirectToMainThread((ChunkMap.TrackedEntity) (Object) this)) {
-                ((IMixinChunkMapAccess) (Object) ((ServerLevel) serverPlayer.level()).chunkSource.chunkMap).gensouHacks$runOnTrackerMainThread(() ->
-                    self.addPairing(serverPlayer)
-                );
-            } else {
-                self.addPairing(serverPlayer);
-            }
-        }
-    }
-}

src/main/java/net/gensokyoreimagined/nitori/core/MixinDirection.java

@@ -1,46 +0,0 @@
-// Nitori Copyright (C) 2024 Gensokyo Reimagined
-//
-// 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 net.gensokyoreimagined.nitori.core;
-
-import net.minecraft.core.Direction;
-import net.minecraft.util.RandomSource;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Overwrite;
-import org.spongepowered.asm.mixin.Shadow;
-
-@Mixin(Direction.class)
-public class MixinDirection {
-    @Shadow @Final private static Direction[] VALUES;
-    @Shadow @Final private int oppositeIndex;
-
-    /**
-     * @author DoggySazHi
-     * @reason Implementation of 0005-lithium-fast-util.patch, requires a overwrite to avoid calling `from3DDataValue`
-     */
-    @Overwrite
-    public Direction getOpposite() {
-        return VALUES[this.oppositeIndex];
-    }
-
-    /**
-     * @author DoggySazHi
-     * @reason Implementation of 0005-lithium-fast-util.patch, requires a overwrite to avoid calling `Util.getRandom`
-     */
-    @Overwrite
-    public static Direction getRandom(RandomSource random) {
-        return VALUES[random.nextInt(VALUES.length)];
-    }
-}

src/main/java/net/gensokyoreimagined/nitori/core/MixinIteratorSafeOrderedReferenceSet.java

@@ -1,30 +0,0 @@
-// Nitori Copyright (C) 2024 Gensokyo Reimagined
-//
-// 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 net.gensokyoreimagined.nitori.core;
-
-import io.papermc.paper.util.maplist.IteratorSafeOrderedReferenceSet;
-import net.gensokyoreimagined.nitori.access.IMixinIteratorSafeOrderedReferenceSetAccess;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Unique;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-@Mixin(IteratorSafeOrderedReferenceSet.class)
-public abstract class MixinIteratorSafeOrderedReferenceSet implements IMixinIteratorSafeOrderedReferenceSetAccess {
-    // Implementation of 0107-Multithreaded-Tracker.patch
-	// @Accessor happens to do exactly what is needed, making for nice shorthand
-    @Override
-    @Accessor
-    public abstract int getListSize(); // Mirai - expose listSize
-}

src/main/java/net/gensokyoreimagined/nitori/core/MixinLevel.java

@@ -1,49 +0,0 @@
-// Nitori Copyright (C) 2024 Gensokyo Reimagined
-//
-// 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 net.gensokyoreimagined.nitori.core;
-
-import com.google.common.collect.Lists;
-import net.gensokyoreimagined.nitori.common.util.collections.HashedReferenceList;
-import net.minecraft.world.level.Level;
-import net.minecraft.world.level.block.entity.TickingBlockEntity;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Mutable;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-
-import java.util.List;
-
-@Mixin(Level.class)
-public class MixinLevel {
-    // Implementation of 0006-lithium-HashedReferenceList.patch
-    @Mutable
-    @Final @Shadow
-    public List<TickingBlockEntity> blockEntityTickers;
-
-    // Implementation of 0006-lithium-HashedReferenceList.patch
-    @Mutable
-    @Final @Shadow
-    private List<TickingBlockEntity> pendingBlockEntityTickers;
-
-    // Implementation of 0006-lithium-HashedReferenceList.patch
-    @Inject(method = "<init>", at = @At("RETURN"))
-    private void onInit(CallbackInfo ci) {
-        this.blockEntityTickers = new HashedReferenceList<>(Lists.newArrayList());
-        this.pendingBlockEntityTickers = new HashedReferenceList<>(Lists.newArrayList());
-    }
-}

src/main/java/net/gensokyoreimagined/nitori/core/MixinServerEntity.java

@@ -1,129 +0,0 @@
-// Nitori Copyright (C) 2024 Gensokyo Reimagined
-//
-// 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 net.gensokyoreimagined.nitori.core;
-
-import com.google.common.collect.Lists;
-import com.llamalad7.mixinextras.sugar.Local;
-import net.gensokyoreimagined.nitori.access.IMixinChunkMapAccess;
-import net.minecraft.network.protocol.Packet;
-import net.minecraft.network.protocol.game.ClientGamePacketListener;
-import net.minecraft.network.protocol.game.ClientboundBundlePacket;
-import net.minecraft.network.protocol.game.ClientboundRemoveEntitiesPacket;
-import net.minecraft.network.protocol.game.ClientboundSetEntityDataPacket;
-import net.minecraft.network.protocol.game.ClientboundUpdateAttributesPacket;
-import net.minecraft.network.syncher.SynchedEntityData;
-import net.minecraft.server.level.ServerEntity;
-import net.minecraft.server.level.ServerLevel;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.server.network.ServerGamePacketListenerImpl;
-import net.minecraft.world.entity.Entity;
-import net.minecraft.world.entity.ai.attributes.AttributeInstance;
-import org.objectweb.asm.Opcodes;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.Redirect;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
-
-import java.util.List;
-import java.util.Set;
-import java.util.function.Consumer;
-
-@Mixin(ServerEntity.class)
-public abstract class MixinServerEntity {
-    @Final
-    @Shadow
-    private Entity entity;
-
-    @Shadow
-    public void sendPairingData(ServerPlayer serverplayer, Consumer<Packet<ClientGamePacketListener>> consumer) {
-        throw new AssertionError("Mixin failed to apply!");
-    }
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @SuppressWarnings("EmptyMethod")
-    @Redirect(method = "removePairing", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/network/ServerGamePacketListenerImpl;send(Lnet/minecraft/network/protocol/Packet;)V"))
-    private void skipSendForOriginalRemovePairing(ServerGamePacketListenerImpl self, Packet<?> packet) {}
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Inject(method = "removePairing", at = @At(value = "TAIL"))
-    private void invokeRemovePairingSendOnMain(ServerPlayer serverplayer, CallbackInfo callbackInfo) {
-        // Mirai start - ensure main thread
-        ((IMixinChunkMapAccess) (Object) ((ServerLevel) this.entity.level()).chunkSource.chunkMap).gensouHacks$runOnTrackerMainThread(() ->
-            serverplayer.connection.send(new ClientboundRemoveEntitiesPacket(this.entity.getId()))
-        );
-        // Mirai end
-    }
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @SuppressWarnings("EmptyMethod")
-    @Redirect(method = "addPairing", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/level/ServerEntity;sendPairingData(Lnet/minecraft/server/level/ServerPlayer;Ljava/util/function/Consumer;)V"))
-    private void skipSendPrepForOriginalAddPairing(ServerEntity self, ServerPlayer serverplayer, Consumer<Packet<ClientGamePacketListener>> consumer) {}
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @SuppressWarnings("EmptyMethod")
-    @Redirect(method = "addPairing", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/network/ServerGamePacketListenerImpl;send(Lnet/minecraft/network/protocol/Packet;)V"))
-    private void skipSendForOriginalAddPairing(ServerGamePacketListenerImpl self, Packet<?> packet) {}
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Inject(method = "addPairing", locals = LocalCapture.CAPTURE_FAILHARD, at = @At(value = "FIELD", target = "Lnet/minecraft/server/level/ServerEntity;entity:Lnet/minecraft/world/entity/Entity;", opcode = Opcodes.GETFIELD, shift = At.Shift.BEFORE))
-    private void invokeAddPairingSendOnMain(ServerPlayer serverplayer, CallbackInfo callbackInfo, @Local List<Packet<ClientGamePacketListener>> list) {
-        ((IMixinChunkMapAccess) (Object) ((ServerLevel) this.entity.level()).chunkSource.chunkMap).gensouHacks$runOnTrackerMainThread(() -> { // Mirai - main thread
-            this.sendPairingData(serverplayer, list::add);
-            serverplayer.connection.send(new ClientboundBundlePacket(list));
-        });
-    }
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @SuppressWarnings("EmptyMethod")
-    @Redirect(method = "sendDirtyEntityData", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/level/ServerEntity;broadcastAndSend(Lnet/minecraft/network/protocol/Packet;)V"))
-    private void skipTrasmitForNonDefault(ServerEntity self, Packet<?> packet) {}
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Inject(method = "sendDirtyEntityData", locals = LocalCapture.CAPTURE_FAILHARD, at = @At(value = "FIELD", target = "Lnet/minecraft/server/level/ServerEntity;entity:Lnet/minecraft/world/entity/Entity;", opcode = Opcodes.GETFIELD, ordinal = 2, shift = At.Shift.BY, by = -4))
-    private void invokeSendForGenericDirtyEntityDataOnMain(CallbackInfo callbackInfo, @Local SynchedEntityData synchedentitydata, @Local List<SynchedEntityData.DataValue<?>> list) {
-        // Mirai start - sync
-        ((IMixinChunkMapAccess) (Object) ((ServerLevel) this.entity.level()).chunkSource.chunkMap).gensouHacks$runOnTrackerMainThread(() ->
-            this.broadcastAndSend(new ClientboundSetEntityDataPacket(this.entity.getId(), list))
-        );
-        // Mirai end
-    }
-
-    // stubbing of broadcastAndSend in if (this.entity instanceof LivingEntity) handled in skipTrasmitForNonDefault
-
-    // Implementation of 0107-Multithreaded-Tracker.patch
-    @Inject(method = "sendDirtyEntityData", at = @At(value = "INVOKE", target = "Ljava/util/Set;clear()V", shift = At.Shift.BY, by = -4))
-    private void invokeSendForLivingDirtyEntityDataOnMain(CallbackInfo callbackInfo, @Local Set<AttributeInstance> set) {
-        // Mirai start - sync
-        final var copy = Lists.newArrayList(set);
-        ((IMixinChunkMapAccess) (Object) ((ServerLevel) this.entity.level()).chunkSource.chunkMap).gensouHacks$runOnTrackerMainThread(() -> {
-            // CraftBukkit start - Send scaled max health
-            if (this.entity instanceof ServerPlayer) {
-                ((ServerPlayer) this.entity).getBukkitEntity().injectScaledMaxHealth(copy, false);
-            }
-            // CraftBukkit end
-            this.broadcastAndSend(new ClientboundUpdateAttributesPacket(this.entity.getId(), copy));
-        });
-        // Mirai end
-    }    
-
-    @Shadow
-    private void broadcastAndSend(Packet<?> packet) {
-        throw new AssertionError("Mixin failed to apply!");
-    }
-}

src/main/java/net/gensokyoreimagined/nitori/core/MixinSpongeSIMD.java

@@ -1,33 +0,0 @@
-// Nitori Copyright (C) 2024 Gensokyo Reimagined
-//
-// 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 net.gensokyoreimagined.nitori.core;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
-
-@Mixin(targets = "gg.pufferfish.pufferfish.simd.SIMDDetection")
-public abstract class MixinSpongeSIMD {
-  @Inject(method = "getJavaVersion", at = @At("RETURN"), cancellable = true)
-  private static void loadPufferfishConfig(CallbackInfoReturnable<Integer> callback) {
-    // We troll the Pufferfish developers by changing the return value of the method
-    // System.out.println("Thought that it was " + callback.getReturnValue() + " for java version");
-    if (callback.getReturnValue() == 21) {
-      System.out.println("Successfully trolled Pufferfish into thinking we're on Java 19!");
-      callback.setReturnValue(19);
-    }
-  }
-}

src/main/java/net/gensokyoreimagined/nitori/core/MixinWorldGenRegion.java

@@ -1,82 +0,0 @@
-// Nitori Copyright (C) 2024 Gensokyo Reimagined
-//
-// 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 net.gensokyoreimagined.nitori.core;
-
-import net.gensokyoreimagined.nitori.common.util.Pos;
-import net.minecraft.core.BlockPos;
-import net.minecraft.server.level.ServerLevel;
-import net.minecraft.server.level.WorldGenRegion;
-import net.minecraft.world.level.ChunkPos;
-import net.minecraft.world.level.block.state.BlockState;
-import net.minecraft.world.level.chunk.ChunkAccess;
-import net.minecraft.world.level.chunk.ChunkStatus;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.Unique;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
-
-import java.util.List;
-
-@Mixin(WorldGenRegion.class)
-public class MixinWorldGenRegion {
-    @Shadow @Final private ChunkPos firstPos;
-    @Shadow @Final private int size;
-
-    @Unique
-    private ChunkAccess[] gensouHacks$chunksArr;
-    @Unique
-    private int gensouHacks$minChunkX;
-    @Unique
-    private int gensouHacks$minChunkZ;
-
-    @Inject(method = "<init>", at = @At("RETURN"))
-    private void onInit(ServerLevel world, List<ChunkAccess> chunks, ChunkStatus status, int placementRadius, CallbackInfo ci) {
-        this.gensouHacks$minChunkX = this.firstPos.x;
-        this.gensouHacks$minChunkZ = this.firstPos.z;
-        this.gensouHacks$chunksArr = chunks.toArray(new ChunkAccess[0]);
-    }
-    
-    @Inject(method = "getChunk(II)Lnet/minecraft/world/level/chunk/ChunkAccess;", at = @At("HEAD"), cancellable = true)
-    public void getChunk(int chunkX, int chunkZ, CallbackInfoReturnable<ChunkAccess> cir) {
-        int x = chunkX - this.gensouHacks$minChunkX;
-        int z = chunkZ - this.gensouHacks$minChunkZ;
-        int w = this.size;
-
-        if (x >= 0 && z >= 0 && x < w && z < w) {
-            cir.setReturnValue(this.gensouHacks$chunksArr[x + z * w]);
-            cir.cancel();
-        } else {
-            throw new NullPointerException("No chunk exists at " + new ChunkPos(chunkX, chunkZ));
-        }
-    }
-    
-    @Inject(method = "getBlockState", at = @At("HEAD"), cancellable = true)
-    public void getBlockState(BlockPos pos, CallbackInfoReturnable<BlockState> cir) {
-        int x = (Pos.ChunkCoord.fromBlockCoord(pos.getX())) - this.gensouHacks$minChunkX;
-        int z = (Pos.ChunkCoord.fromBlockCoord(pos.getZ())) - this.gensouHacks$minChunkZ;
-        int w = this.size;
-
-        if (x >= 0 && z >= 0 && x < w && z < w) {
-            cir.setReturnValue(this.gensouHacks$chunksArr[x + z * w].getBlockState(pos));
-            cir.cancel();
-        } else {
-            throw new NullPointerException("No chunk exists at " + new ChunkPos(pos));
-        }
-    }
-}

src/main/java/net/gensokyoreimagined/nitori/mixin/MixinBlockPos.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.mixin;
 
 import it.unimi.dsi.fastutil.longs.LongList;
 import net.gensokyoreimagined.nitori.cached_blockpos_iteration.IterateOutwardsCache;

src/main/java/net/gensokyoreimagined/nitori/mixin/MixinEntity.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.mixin;
 
 import net.minecraft.core.BlockPos;
 import net.minecraft.world.entity.Entity;
@@ -39,7 +39,7 @@ public abstract class MixinEntity {
      * Implementation of 0065-some-entity-micro-opts.patch
      */
     @Unique
-    public float gensouHacks$getLightLevelDependentMagicValue(BlockPos pos) {
+    public float nitori$getLightLevelDependentMagicValue(BlockPos pos) {
         return this.level.hasChunkAt(this.getBlockX(), this.getBlockZ()) ? this.level.getLightLevelDependentMagicValue(pos) : 0.0F;
     }
 
@@ -48,7 +48,7 @@ public abstract class MixinEntity {
      */
     @Inject(method = "getLightLevelDependentMagicValue", at = @At("HEAD"), cancellable = true)
     private void getLightLevelDependentMagicValue(CallbackInfoReturnable<Float> cir) {
-        cir.setReturnValue(this.gensouHacks$getLightLevelDependentMagicValue(new BlockPos(this.getBlockX(), (int) this.getEyeY(), this.getBlockZ())));
+        cir.setReturnValue(this.nitori$getLightLevelDependentMagicValue(new BlockPos(this.getBlockX(), (int) this.getEyeY(), this.getBlockZ())));
         cir.cancel();
     }
 }

src/main/java/net/gensokyoreimagined/nitori/mixin/MixinEntitySectionStorage.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.mixin;
 
 import com.llamalad7.mixinextras.sugar.Local;
 import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
@@ -79,12 +79,12 @@ public class MixinEntitySectionStorage<T extends EntityAccess> {
             // are placed somewhere inside the packed long
             for (int x = j; x <= m; x++) {
                 for (int z = Math.max(l, 0); z <= o; z++) {
-                    this.gensouHacks$forEachInColumn(x, k, n, z, consumer);
+                    this.nitori$forEachInColumn(x, k, n, z, consumer);
                 }
 
                 int bound = Math.min(-1, o);
                 for (int z = l; z <= bound; z++) {
-                    this.gensouHacks$forEachInColumn(x, k, n, z, consumer);
+                    this.nitori$forEachInColumn(x, k, n, z, consumer);
                 }
             }
         }
@@ -95,19 +95,19 @@ public class MixinEntitySectionStorage<T extends EntityAccess> {
 
     // Mirai start - lithium: fast retrieval
     @Unique
-    private void gensouHacks$forEachInColumn(int x, int k, int n, int z, AbortableIterationConsumer<EntitySection<T>> action) {
+    private void nitori$forEachInColumn(int x, int k, int n, int z, AbortableIterationConsumer<EntitySection<T>> action) {
         // y from negative to positive, but y is treated as unsigned
         for (int y = Math.max(k, 0); y <= n; y++) {
-            this.gensouHacks$consumeSection(SectionPos.asLong(x, y, z), action);
+            this.nitori$consumeSection(SectionPos.asLong(x, y, z), action);
         }
         int bound = Math.min(-1, n);
         for (int y = k; y <= bound; y++) {
-            this.gensouHacks$consumeSection(SectionPos.asLong(x, y, z), action);
+            this.nitori$consumeSection(SectionPos.asLong(x, y, z), action);
         }
     }
 
     @Unique
-    private void gensouHacks$consumeSection(long pos, AbortableIterationConsumer<EntitySection<T>> action) {
+    private void nitori$consumeSection(long pos, AbortableIterationConsumer<EntitySection<T>> action) {
         EntitySection<T> entitySection = this.getSection(pos);
         if (entitySection != null && !entitySection.isEmpty() && entitySection.getStatus().isAccessible()) {
             action.accept(entitySection);

src/main/java/net/gensokyoreimagined/nitori/mixin/MixinEntityTickList.java

@@ -0,0 +1,70 @@
+package net.gensokyoreimagined.nitori.mixin;
+
+import it.unimi.dsi.fastutil.ints.Int2ObjectLinkedOpenHashMap;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.entity.EntityTickList;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.util.function.Consumer;
+
+@Mixin(EntityTickList.class)
+public class MixinEntityTickList {
+    @Unique
+    private Int2ObjectLinkedOpenHashMap<Entity> nitori$entities = new Int2ObjectLinkedOpenHashMap<>();
+    @Unique
+    private Int2ObjectLinkedOpenHashMap<Entity> nitori$iteratorPointer = null;
+
+    // I've decided I hate Paper's design.
+    // All of these are effectively Overwrites.
+
+    @Unique
+    private void nitori$ensureActiveIsNotIterated() {
+        if (nitori$iteratorPointer == nitori$entities) {
+            // Avoid a ConcurrentModificationException by cloning the map before modifying it.
+            // Side effect is that it allocates more memory to avoid blocking the main thread, but it's all pointers anyway.
+            nitori$entities = nitori$entities.clone();
+        }
+    }
+
+    @Inject(method = "add", at = @At("HEAD"), cancellable = true)
+    public void add(Entity entity, CallbackInfo ci) {
+        nitori$ensureActiveIsNotIterated();
+        nitori$entities.put(entity.getId(), entity);
+        ci.cancel();
+    }
+
+    @Inject(method = "remove", at = @At("HEAD"), cancellable = true)
+    public void remove(Entity entity, CallbackInfo ci) {
+        nitori$ensureActiveIsNotIterated();
+        nitori$entities.remove(entity.getId());
+        ci.cancel();
+    }
+
+    @Inject(method = "contains", at = @At("HEAD"), cancellable = true)
+    public void contains(Entity entity, CallbackInfoReturnable<Boolean> ci) {
+        ci.setReturnValue(nitori$entities.containsKey(entity.getId()));
+        ci.cancel();
+    }
+
+    @Inject(method = "forEach", at = @At("HEAD"), cancellable = true)
+    public void forEach(Consumer<Entity> action, CallbackInfo ci) {
+        if (nitori$iteratorPointer == nitori$entities) {
+            nitori$entities = nitori$entities.clone(); // Avoid a ConcurrentModificationException by cloning the map before iterating over it.
+        }
+
+        nitori$iteratorPointer = nitori$entities; // Mark the map as being iterated.
+
+        try {
+            nitori$iteratorPointer.values().forEach(action); // Iterate over the map.
+        } finally {
+            nitori$iteratorPointer = null; // Mark the map as no longer being iterated.
+        }
+
+        ci.cancel();
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/MixinNoiseBasedChunkGenerator.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.mixin;
 
 import com.google.common.base.Supplier;
 import com.google.common.base.Suppliers;

src/main/java/net/gensokyoreimagined/nitori/mixin/MixinReobfServer.java

@@ -0,0 +1,51 @@
+// Nitori Copyright (C) 2024 Gensokyo Reimagined
+//
+// 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 net.gensokyoreimagined.nitori.mixin;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import space.vectrix.ignite.Blackboard;
+
+import java.net.URISyntaxException;
+import java.nio.file.Path;
+
+@Mixin(targets = "io.papermc.paper.pluginremap.ReobfServer")
+public class MixinReobfServer {
+    @Inject(method = "serverJar", at = @At("HEAD"), cancellable = true)
+    private static void serverJar(CallbackInfoReturnable<Path> cir) {
+        try {
+            var igniteGameJarPath = Blackboard.get(Blackboard.GAME_JAR);
+            System.out.println("Nitori: ReobfServer.serverJar() called" + igniteGameJarPath);
+
+            if (igniteGameJarPath.isPresent()) {
+                System.out.println("Nitori: ReobfServer.serverJar() found Ignite, returning " + igniteGameJarPath.get());
+                cir.setReturnValue(igniteGameJarPath.get());
+                cir.cancel();
+                return;
+            }
+
+            // This is a fallback in case the game jar path is not set for some reason
+            var path = Path.of(MixinReobfServer.class.getProtectionDomain().getCodeSource().getLocation().toURI());
+            System.out.println("Nitori: ReobfServer.serverJar() tried loading, returning " + path);
+            cir.setReturnValue(path);
+            cir.cancel();
+        } catch (final URISyntaxException ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/alloc/MixinIdentifier.java

@@ -0,0 +1,34 @@
+package net.gensokyoreimagined.nitori.mixin.alloc;
+
+import net.minecraft.resources.ResourceLocation;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+
+@Mixin(ResourceLocation.class)
+public class MixinIdentifier {
+
+    @Shadow @Final
+    private String namespace;
+
+    @Shadow @Final
+    private String path;
+
+    @Unique
+    private String nitori$cachedString = null;
+
+    /**
+     * @author ishland
+     * @reason cache toString
+     */
+    @Overwrite
+    public String toString() {
+        if (this.nitori$cachedString != null) return this.nitori$cachedString;
+        final String s = this.namespace + ":" + this.path;
+        this.nitori$cachedString = s;
+        return s;
+    }
+
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/alloc/biome_temprature_leak/Biome_threadLocalMixin.java

@@ -0,0 +1,39 @@
+package net.gensokyoreimagined.nitori.mixin.alloc.biome_temprature_leak;
+
+import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import it.unimi.dsi.fastutil.longs.Long2FloatLinkedOpenHashMap;
+import net.minecraft.world.level.biome.Biome;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+
+import java.util.function.Supplier;
+
+@Mixin(Biome.class)
+public abstract class Biome_threadLocalMixin {
+
+    /*
+     * Not only do I absolutely hate this garbage cache, cause it barely works at all.
+     * HOW did nobody at mojang notice that this thread local was not static, how on earth is a non-static private
+     * value suppose to run on multiple threads at the same time.
+     * So now its static so that it actually works like its suppose to, and you don't need to declare a billion of them
+     *
+     * This is a significant performance boost & reduces a lot of memory usage
+     */
+
+    private static ThreadLocal<Long2FloatLinkedOpenHashMap> memoryLeakFix$betterTempCache;
+
+    @WrapOperation(
+            method = "<init>",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Ljava/lang/ThreadLocal;withInitial(Ljava/util/function/Supplier;)Ljava/lang/ThreadLocal;"
+            )
+    )
+    private ThreadLocal<Long2FloatLinkedOpenHashMap> memoryLeakFix$useStaticThreadLocal(Supplier<?> supplier, Operation<ThreadLocal<Long2FloatLinkedOpenHashMap>> original) {
+        if (memoryLeakFix$betterTempCache == null) {
+            memoryLeakFix$betterTempCache = original.call(supplier);
+        }
+        return memoryLeakFix$betterTempCache;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/alloc/blockstate/StateMixin.java

@@ -0,0 +1,49 @@
+// Nitori Copyright (C) 2024 Gensokyo Reimagined
+//
+// 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 net.gensokyoreimagined.nitori.mixin.alloc.blockstate;
+
+import com.google.common.collect.Table;
+import net.gensokyoreimagined.nitori.common.state.FastImmutableTable;
+import net.gensokyoreimagined.nitori.common.state.StatePropertyTableCache;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.state.StateHolder;
+import net.minecraft.world.level.block.state.properties.Property;
+import net.minecraft.world.level.material.Fluid;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.Map;
+
+@Mixin(StateHolder.class)
+public class StateMixin<O, S> {
+    @Shadow
+    private Table<Property<?>, Comparable<?>, S> neighbours;
+
+    @Shadow
+    @Final
+    protected O owner;
+
+    @Inject(method = "populateNeighbours", at = @At("RETURN"))
+    private void postCreateWithTable(Map<Map<Property<?>, Comparable<?>>, S> states, CallbackInfo ci) {
+        if (this.owner instanceof Block || this.owner instanceof Fluid) {
+            this.neighbours = new FastImmutableTable<Property<?>, Comparable<?>, S>(this.neighbours, StatePropertyTableCache.getTableCache(this.owner));
+        }
+    }
+
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/alloc/chunk_random/WorldMixin.java

@@ -0,0 +1,23 @@
+package net.gensokyoreimagined.nitori.mixin.alloc.chunk_random;
+
+import net.gensokyoreimagined.nitori.common.world.ChunkRandomSource;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.Level;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(Level.class)
+public class WorldMixin implements ChunkRandomSource {
+    @Shadow
+    protected int randValue;
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void nitori$getRandomPosInChunk(int x, int y, int z, int mask, BlockPos.MutableBlockPos out) {
+        this.randValue = this.randValue * 3 + 1013904223;
+        int rand = this.randValue >> 2;
+        out.set(x + (rand & 15), y + (rand >> 16 & mask), z + (rand >> 8 & 15));
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/alloc/composter/ComposterMixin.java

@@ -0,0 +1,46 @@
+package net.gensokyoreimagined.nitori.mixin.alloc.composter;
+
+import net.gensokyoreimagined.nitori.common.util.ArrayConstants;
+import net.minecraft.world.WorldlyContainer;
+import net.minecraft.core.Direction;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+
+public class ComposterMixin {
+
+    @Mixin(targets = "net.minecraft.world.level.block.ComposterBlock$InputContainer")
+    static abstract class ComposterBlockComposterInventoryMixin implements WorldlyContainer {
+        /**
+         * @author 2No2Name
+         * @reason avoid allocation
+         */
+        @Overwrite
+        public int[] getSlotsForFace(Direction side) {
+            return side == Direction.UP ? ArrayConstants.ZERO : ArrayConstants.EMPTY;
+        }
+    }
+
+    @Mixin(targets = "net.minecraft.world.level.block.ComposterBlock$EmptyContainer")
+    static abstract class ComposterBlockDummyInventoryMixin implements WorldlyContainer {
+        /**
+         * @author 2No2Name
+         * @reason avoid allocation
+         */
+        @Overwrite
+        public int[] getSlotsForFace(Direction side) {
+            return ArrayConstants.EMPTY;
+        }
+    }
+
+    @Mixin(targets = "net.minecraft.world.level.block.ComposterBlock$OutputContainer")
+    static abstract class ComposterBlockFullComposterInventoryMixin implements WorldlyContainer {
+        /**
+         * @author 2No2Name
+         * @reason avoid allocation
+         */
+        @Overwrite
+        public int[] getSlotsForFace(Direction side) {
+            return side == Direction.DOWN ? ArrayConstants.ZERO : ArrayConstants.EMPTY;
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/alloc/package-info.java

@@ -0,0 +1,6 @@
+package net.gensokyoreimagined.nitori.mixin.alloc;
+
+/*
+ /nbt/NbtCompoundMixin is not needed
+
+ */

src/main/java/net/gensokyoreimagined/nitori/mixin/cached_hashcode/BlockNeighborGroupMixin.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.mixin.cached_hashcode;
 
 import net.minecraft.core.Direction;
 import net.minecraft.world.level.block.Block;
@@ -22,16 +22,8 @@ import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
-/*
- * Originally from CaffeineMC, licensed under GNU Lesser General Public License v3.0
- * See https://github.com/CaffeineMC/lithium-fabric for more information/sources
- */
-
 @Mixin(Block.BlockStatePairKey.class)
-public class MixinBlock {
-    @Unique
-    private int gensouHacks$hash;
-
+public class BlockNeighborGroupMixin {
     @Shadow
     @Final
     private BlockState first;
@@ -44,20 +36,27 @@ public class MixinBlock {
     @Final
     private Direction direction;
 
+    @Unique
+    private int nitori$hash;
+
+    /**
+     * @reason Initialize the object's hashcode and cache it
+     */
     @Inject(method = "<init>", at = @At("RETURN"))
-    private void init(CallbackInfo info) {
-        int hash = first.hashCode();
-        hash = 31 * hash + second.hashCode();
-        hash = 31 * hash + direction.hashCode();
-        this.gensouHacks$hash = hash;
+    private void generateHash(BlockState blockState_1, BlockState blockState_2, Direction direction_1, CallbackInfo ci) {
+        int hash = this.first.hashCode();
+        hash = 31 * hash + this.second.hashCode();
+        hash = 31 * hash + this.direction.hashCode();
+
+        this.nitori$hash = hash;
     }
 
     /**
-     * @author DoggySazHi
-     * @reason Implementation of 0045-lithium-cached-hashcode.patch
+     * @reason Uses the cached hashcode
+     * @author JellySquid
      */
-    @Overwrite
+    @Overwrite(remap = false)
     public int hashCode() {
-        return this.gensouHacks$hash;
+        return this.nitori$hash;
     }
-}
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/chunk/entity_class_groups/TypeFilterableListMixin.java

@@ -0,0 +1,86 @@
+package net.gensokyoreimagined.nitori.mixin.chunk.entity_class_groups;
+
+import it.unimi.dsi.fastutil.objects.Reference2ReferenceArrayMap;
+import it.unimi.dsi.fastutil.objects.ReferenceLinkedOpenHashSet;
+import net.gensokyoreimagined.nitori.common.entity.EntityClassGroup;
+import net.gensokyoreimagined.nitori.common.world.chunk.ClassGroupFilterableList;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.util.ClassInstanceMultiMap;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.ModifyVariable;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Patches {@link ClassInstanceMultiMap} to allow grouping entities by arbitrary groups of classes instead of one class only.
+ */
+@Mixin(ClassInstanceMultiMap.class)
+public abstract class TypeFilterableListMixin<T> implements ClassGroupFilterableList<T> {
+
+    @Shadow
+    @Final
+    private List<T> allInstances;
+
+    private final Reference2ReferenceArrayMap<EntityClassGroup, ReferenceLinkedOpenHashSet<T>> nitori$entitiesByGroup =
+            new Reference2ReferenceArrayMap<>();
+
+    /**
+     * Update our collections
+     */
+    @ModifyVariable(method = "add(Ljava/lang/Object;)Z", at = @At("HEAD"), argsOnly = true)
+    public T add(T entity) {
+        for (Map.Entry<EntityClassGroup, ReferenceLinkedOpenHashSet<T>> entityGroupAndSet : this.nitori$entitiesByGroup.entrySet()) {
+            EntityClassGroup entityGroup = entityGroupAndSet.getKey();
+            if (entityGroup.contains(((Entity) entity).getClass())) {
+                entityGroupAndSet.getValue().add((entity));
+            }
+        }
+        return entity;
+    }
+
+    /**
+     * Update our collections
+     */
+    @ModifyVariable(method = "remove(Ljava/lang/Object;)Z", at = @At("HEAD"), argsOnly = true)
+    public Object remove(Object o) {
+        for (ReferenceLinkedOpenHashSet<T> entitySet : this.nitori$entitiesByGroup.values()) {
+            //noinspection SuspiciousMethodCalls
+            entitySet.remove(o);
+        }
+        return o;
+    }
+
+    /**
+     * Get entities of a class group
+     */
+    public Collection<T> lithium$getAllOfGroupType(EntityClassGroup type) {
+        Collection<T> collection = this.nitori$entitiesByGroup.get(type);
+
+        if (collection == null) {
+            collection = this.nitori$createAllOfGroupType(type);
+        }
+
+        return collection;
+    }
+
+    /**
+     * Start grouping by a new class group
+     */
+    private Collection<T> nitori$createAllOfGroupType(EntityClassGroup type) {
+        ReferenceLinkedOpenHashSet<T> allOfType = new ReferenceLinkedOpenHashSet<>();
+
+        for (T entity : this.allInstances) {
+            if (type.contains(entity.getClass())) {
+                allOfType.add(entity);
+            }
+        }
+        this.nitori$entitiesByGroup.put(type, allOfType);
+
+        return allOfType;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/collections/block_entity_tickers/WorldChunkMixin.java

@@ -0,0 +1,38 @@
+package net.gensokyoreimagined.nitori.mixin.collections.block_entity_tickers;
+
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.chunk.UpgradeData;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.levelgen.blending.BlendingData;
+import net.minecraft.world.ticks.LevelChunkTicks;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Coerce;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.Map;
+
+@Mixin(LevelChunk.class)
+public class WorldChunkMixin {
+    @Mutable
+    @Shadow
+    @Final
+    private Map<BlockPos, ?> tickersInLevel;
+
+    @Inject(
+            method = "<init>(Lnet/minecraft/world/level/Level;Lnet/minecraft/world/level/ChunkPos;Lnet/minecraft/world/level/chunk/UpgradeData;Lnet/minecraft/world/ticks/LevelChunkTicks;Lnet/minecraft/world/ticks/LevelChunkTicks;J[Lnet/minecraft/world/level/chunk/LevelChunkSection;Lnet/minecraft/world/level/chunk/LevelChunk$PostLoadProcessor;Lnet/minecraft/world/level/levelgen/blending/BlendingData;)V",
+            at = @At("TAIL")
+    )
+    @Coerce
+    private void createFastUtilMap(Level world, ChunkPos pos, UpgradeData upgradeData, LevelChunkTicks<?> blockTickScheduler, LevelChunkTicks<?> fluidTickScheduler, long inhabitedTime, LevelChunkSection[] sectionArrayInitializer, LevelChunk.PostLoadProcessor entityLoader, BlendingData blendingData, CallbackInfo ci) {
+        this.tickersInLevel = new Object2ObjectOpenHashMap<>();
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/collections/brain/BrainMixin.java

@@ -0,0 +1,53 @@
+package net.gensokyoreimagined.nitori.mixin.collections.brain;
+
+import com.google.common.collect.ImmutableList;
+import it.unimi.dsi.fastutil.Pair;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.Reference2ReferenceLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.objects.Reference2ReferenceOpenHashMap;
+import net.minecraft.world.entity.ai.Brain;
+import net.minecraft.world.entity.ai.memory.MemoryModuleType;
+import net.minecraft.world.entity.ai.memory.MemoryStatus;
+import net.minecraft.world.entity.schedule.Activity;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Supplier;
+
+@Mixin(Brain.class)
+public class BrainMixin {
+
+    @Mutable
+    @Shadow
+    @Final
+    private Map<?, ?> memories;
+
+    @Mutable
+    @Shadow
+    @Final
+    private Map<?, ?> sensors;
+
+    @Shadow
+    @Final
+    @Mutable
+    private Map<Activity, Set<Pair<MemoryModuleType<?>, MemoryStatus>>> activityRequirements;
+
+    @Inject(
+            method = "<init>",
+            at = @At("RETURN")
+    )
+    private void reinitializeBrainCollections(Collection<?> memories, Collection<?> sensors, ImmutableList<?> memoryEntries, Supplier<?> codecSupplier, CallbackInfo ci) {
+        this.memories = new Reference2ReferenceOpenHashMap<>(this.memories);
+        this.sensors = new Reference2ReferenceLinkedOpenHashMap<>(this.sensors);
+        this.activityRequirements = new Object2ObjectOpenHashMap<>(this.activityRequirements);
+    }
+
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/collections/chunk_tickets/SortedArraySetMixin.java

@@ -0,0 +1,52 @@
+package net.gensokyoreimagined.nitori.mixin.collections.chunk_tickets;
+
+import net.minecraft.util.SortedArraySet;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import java.util.Collection;
+import java.util.function.Predicate;
+
+@Mixin(SortedArraySet.class)
+public abstract class SortedArraySetMixin<T> implements Collection<T> {
+    @Shadow
+    int size;
+
+    @Shadow
+     T[] contents ;
+
+    /**
+     * Add an optimized implementation of {@link Collection#removeIf(Predicate)} which doesn't attempt to shift
+     * the values in the array multiple times with each removal. This also eliminates a number of object allocations
+     * and works on the direct backing array, speeding things up a fair chunk.
+     */
+    @Override
+    public boolean removeIf(Predicate<? super T> filter) {
+        T[] arr = this.contents ;
+
+        int writeLim = this.size;
+        int writeIdx = 0;
+
+        for (int readIdx = 0; readIdx < writeLim; readIdx++) {
+            T obj = arr[readIdx];
+
+            // If the filter does not pass the object, simply skip over it. The write pointer will
+            // not be advanced and the next element to pass will instead take this one's place.
+            if (filter.test(obj)) {
+                continue;
+            }
+
+            // If the read and write pointers are the same, then no removals have occurred so far. This
+            // allows us to skip copying unchanged values back into the array.
+            if (writeIdx != readIdx) {
+                arr[writeIdx] = obj;
+            }
+
+            writeIdx++;
+        }
+
+        this.size = writeIdx;
+
+        return writeLim != writeIdx;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/collections/entity_by_type/TypeFilterableListMixin.java

@@ -0,0 +1,28 @@
+package net.gensokyoreimagined.nitori.mixin.collections.entity_by_type;
+
+import it.unimi.dsi.fastutil.objects.Reference2ReferenceOpenHashMap;
+import net.minecraft.util.ClassInstanceMultiMap;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.List;
+import java.util.Map;
+
+@Mixin(ClassInstanceMultiMap.class)
+public class TypeFilterableListMixin {
+
+    @Mutable
+    @Shadow
+    @Final
+    private Map<Class<?>, List<?>> byClass;
+
+    @Inject(method = "<init>", at = @At("RETURN"))
+    private void init(Class<?> elementType, CallbackInfo ci) {
+        this.byClass = new Reference2ReferenceOpenHashMap<>(this.byClass);
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/collections/entity_filtering/TypeFilterableListMixin.java

@@ -0,0 +1,55 @@
+package net.gensokyoreimagined.nitori.mixin.collections.entity_filtering;
+
+import net.minecraft.util.ClassInstanceMultiMap;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+import org.spongepowered.asm.mixin.Shadow;
+
+import java.util.*;
+
+/**
+ * Patches {@link ClassInstanceMultiMap} to improve performance when entities are being queried in the world.
+ */
+@Mixin(ClassInstanceMultiMap.class)
+public class TypeFilterableListMixin<T> {
+
+    @Shadow
+    @Final
+    private Map<Class<?>, List<T>> byClass;
+
+    @Shadow
+    @Final
+    private List<T> allInstances;
+
+    /**
+     * @reason Only perform the slow Class#isAssignableFrom(Class) if a list doesn't exist for the type, otherwise
+     * we can assume it's already valid. The slow-path code is moved to a separate method to help the JVM inline this.
+     * @author JellySquid
+     */
+    @SuppressWarnings("unchecked")
+    @Overwrite
+    public <S> Collection<S> find(Class<S> type) {
+        Collection<T> collection = this.byClass.get(type);
+
+        if (collection == null) {
+            collection = this.createAllOfType(type);
+        }
+
+        return (Collection<S>) Collections.unmodifiableCollection(collection);
+    }
+
+    private <S> Collection<T> createAllOfType(Class<S> type) {
+        List<T> list = new ArrayList<>();
+
+        for (T allElement : this.allInstances) {
+            if (type.isInstance(allElement)) {
+                list.add(allElement);
+            }
+        }
+
+        this.byClass.put(type, list);
+
+        return list;
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/collections/fluid_submersion/EntityMixin.java

@@ -0,0 +1,44 @@
+package net.gensokyoreimagined.nitori.mixin.collections.fluid_submersion;
+
+import it.unimi.dsi.fastutil.objects.ReferenceArraySet;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.material.Fluid;
+import net.minecraft.tags.TagKey;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.Set;
+
+@Mixin(Entity.class)
+public class EntityMixin {
+
+    @Mutable
+    @Shadow
+    @Final
+    private Set<TagKey<Fluid>> fluidOnEyes;
+
+    @Inject(
+            method = "<init>",
+            at = @At("RETURN")
+    )
+    private void useReferenceArraySet(CallbackInfo ci) {
+        this.fluidOnEyes = new ReferenceArraySet<>(this.fluidOnEyes);
+    }
+
+    @Redirect(
+            method = "updateFluidOnEyes",
+            at = @At(value = "INVOKE", target = "Ljava/util/Set;clear()V"),
+            require = 0
+    )
+    private void clearIfNotEmpty(Set<?> set) {
+        if (!set.isEmpty()) {
+            set.clear();
+        }
+    }
+}

src/main/java/net/gensokyoreimagined/nitori/mixin/collections/gamerules/MixinGameRules.java

@@ -12,7 +12,7 @@
 //
 // 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 net.gensokyoreimagined.nitori.core;
+package net.gensokyoreimagined.nitori.mixin.collections.gamerules;
 
 import com.google.common.collect.ImmutableMap;
 import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;