From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrHua269 <mrhua269@gmail.com>
Date: Sun, 17 May 2026 10:10:21 +0800
Subject: [PATCH] Leaf fast bit radix sort

This is a part of Leaf(https://github.com/Winds-Studio/Leaf/blob/d0ed97cf45dfa94f686ef32f0eea1ec7323f78d5/leaf-server/minecraft-patches/features/0284-fast-bit-radix-sort.patch)

Original license: https://github.com/Winds-Studio/Leaf/blob/d0ed97cf45dfa94f686ef32f0eea1ec7323f78d5/LICENSE.md

diff --git a/io/papermc/paper/threadedregions/RegionizedWorldData.java b/io/papermc/paper/threadedregions/RegionizedWorldData.java
index 08e4adac3425a94f9bcf5191883d333cfe5bf5c9..e540458c7b21dd01c05012a82deee6a3ad613e24 100644
--- a/io/papermc/paper/threadedregions/RegionizedWorldData.java
+++ b/io/papermc/paper/threadedregions/RegionizedWorldData.java
@@ -525,6 +525,7 @@ public final class RegionizedWorldData {
     public final PathTypeCache pathTypesByPosCache = new PathTypeCache();
     public final List<LevelChunk> temporaryChunkTickList = new java.util.ArrayList<>();
     public final Set<ChunkHolder> chunkHoldersToBroadcast = new ReferenceLinkedOpenHashSet<>();
+    public final org.dreeam.leaf.util.FastBitRadixSort radixBitSorter = new org.dreeam.leaf.util.FastBitRadixSort(); // Leaf - quick sort
 
     // not transient
     public java.util.ArrayDeque<net.minecraft.world.level.block.RedstoneTorchBlock.Toggle> redstoneUpdateInfos;
diff --git a/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java b/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java
index 8aeea55380462421cde43afb4b2fb0ce44b65195..73247b46d778dcb9b3be742e4e4c4c037e3ac0e5 100644
--- a/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java
+++ b/net/minecraft/world/entity/ai/sensing/NearestItemSensor.java
@@ -15,6 +15,7 @@ public class NearestItemSensor extends Sensor<Mob> {
     private static final long XZ_RANGE = 32L;
     private static final long Y_RANGE = 16L;
     public static final int MAX_DISTANCE_TO_WANTED_ITEM = 32;
+    private static final double MAX_DIST_SQ = (double) MAX_DISTANCE_TO_WANTED_ITEM * MAX_DISTANCE_TO_WANTED_ITEM; // Leaf - quick sort
 
     @Override
     public Set<MemoryModuleType<?>> requires() {
@@ -24,8 +25,16 @@ public class NearestItemSensor extends Sensor<Mob> {
     @Override
     protected void doTick(final ServerLevel level, final Mob body) {
         Brain<?> brain = body.getBrain();
-        List<ItemEntity> items = level.getEntitiesOfClass(ItemEntity.class, body.getBoundingBox().inflate(32.0, 16.0, 32.0), item -> item.closerThan(body, MAX_DISTANCE_TO_WANTED_ITEM) && body.wantsToPickUp(level, item.getItem())); // Paper - Perf: Move predicate into getEntities
-        items.sort(Comparator.comparingDouble(body::distanceToSqr));
+        // Leaf start - fast bit radix sort
+        net.minecraft.core.Position pos = body.position();
+        double x = pos.x();
+        double y = pos.y();
+        double z = pos.z();
+        net.minecraft.world.phys.AABB boundingBox = body.getBoundingBox().inflate(32.0, 16.0, 32.0);
+        it.unimi.dsi.fastutil.objects.ObjectArrayList<ItemEntity> items = new it.unimi.dsi.fastutil.objects.ObjectArrayList<>();
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel) level).moonrise$getEntityLookup().getEntities(ItemEntity.class, null, boundingBox, items, (ItemEntity itemEntity) -> itemEntity.distanceToSqr(x, y, z) < MAX_DIST_SQ && body.wantsToPickUp(level, itemEntity.getItem())); // Paper - Perf: Move predicate into getEntities
+        level.getCurrentWorldData().radixBitSorter.sort(items.elements(), items.size(), pos);
+        // Leaf end - fast bit radix sort
         // Paper start - Perf: remove streams from hot code
         ItemEntity nearest = null;
         for (final ItemEntity item : items) {
diff --git a/net/minecraft/world/entity/ai/sensing/NearestLivingEntitySensor.java b/net/minecraft/world/entity/ai/sensing/NearestLivingEntitySensor.java
index 3578ece216827fd5d8c1206c689fc608e97b50df..9fbe439663edf57e018369a44ed7576d947d1fbc 100644
--- a/net/minecraft/world/entity/ai/sensing/NearestLivingEntitySensor.java
+++ b/net/minecraft/world/entity/ai/sensing/NearestLivingEntitySensor.java
@@ -17,8 +17,11 @@ public class NearestLivingEntitySensor<T extends LivingEntity> extends Sensor<T>
     protected void doTick(final ServerLevel level, final T body) {
         double followRange = body.getAttributeValue(Attributes.FOLLOW_RANGE);
         AABB boundingBox = body.getBoundingBox().inflate(followRange, followRange, followRange);
-        List<LivingEntity> livingEntities = level.getEntitiesOfClass(LivingEntity.class, boundingBox, mob -> mob != body && mob.isAlive());
-        livingEntities.sort(Comparator.comparingDouble(body::distanceToSqr));
+        // Leaf start - fast bit radix sort
+        it.unimi.dsi.fastutil.objects.ObjectArrayList<LivingEntity> livingEntities = new it.unimi.dsi.fastutil.objects.ObjectArrayList<>();
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel) level).moonrise$getEntityLookup().getEntities(LivingEntity.class, body, boundingBox, livingEntities, LivingEntity::isAlive);
+        level.getCurrentWorldData().radixBitSorter.sort(livingEntities.elements(), livingEntities.size(), body.position());
+        // Leaf end - fast bit radix sort
         Brain<?> brain = body.getBrain();
         brain.setMemory(MemoryModuleType.NEAREST_LIVING_ENTITIES, livingEntities);
         brain.setMemory(MemoryModuleType.NEAREST_VISIBLE_LIVING_ENTITIES, new NearestVisibleLivingEntities(level, body, livingEntities));