From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Tue, 5 May 2020 20:40:53 -0700
Subject: [PATCH] Optimize anyPlayerCloseEnoughForSpawning to use distance maps

Use a distance map to find the players in range quickly

diff --git a/src/main/java/net/minecraft/server/level/ChunkHolder.java b/src/main/java/net/minecraft/server/level/ChunkHolder.java
index 74d674b2684b0db4aa6c183edc6091d53e9ee882..560cc04ee7a8fd0c3c7217e08d53d1da682054e2 100644
--- a/src/main/java/net/minecraft/server/level/ChunkHolder.java
+++ b/src/main/java/net/minecraft/server/level/ChunkHolder.java
@@ -73,6 +73,23 @@ public class ChunkHolder {
     boolean isUpdateQueued = false; // Paper
     private final ChunkMap chunkMap; // Paper
 
+    // Paper start - optimise anyPlayerCloseEnoughForSpawning
+    // cached here to avoid a map lookup
+    com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInMobSpawnRange;
+    com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInChunkTickRange;
+
+    void onChunkAdd() {
+        long key = net.minecraft.server.MCUtil.getCoordinateKey(this.pos);
+        this.playersInMobSpawnRange = this.chunkMap.playerMobSpawnMap.getObjectsInRange(key);
+        this.playersInChunkTickRange = this.chunkMap.playerChunkTickRangeMap.getObjectsInRange(key);
+    }
+
+    void onChunkRemove() {
+        this.playersInMobSpawnRange = null;
+        this.playersInChunkTickRange = null;
+    }
+    // Paper end - optimise anyPlayerCloseEnoughForSpawning
+
     public ChunkHolder(ChunkPos pos, int level, LevelHeightAccessor world, LevelLightEngine lightingProvider, ChunkHolder.LevelChangeListener levelUpdateListener, ChunkHolder.PlayerProvider playersWatchingChunkProvider) {
         this.futures = new AtomicReferenceArray(ChunkHolder.CHUNK_STATUSES.size());
         this.fullChunkFuture = ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE;
@@ -94,6 +111,7 @@ public class ChunkHolder {
         this.setTicketLevel(level);
         this.changedBlocksPerSection = new ShortSet[world.getSectionsCount()];
         this.chunkMap = (ChunkMap)playersWatchingChunkProvider; // Paper
+        this.onChunkAdd(); // Paper - optimise anyPlayerCloseEnoughForSpawning
     }
 
     // CraftBukkit start
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index 00eeaa04c98a658bac63f72da6b6d157131e9120..cd58121bfa059366919e098005299dde0c55f46f 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -177,11 +177,23 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     final CallbackExecutor chunkLoadConversionCallbackExecutor = new CallbackExecutor(); // Paper
     // Paper start - distance maps
     private final com.destroystokyo.paper.util.misc.PooledLinkedHashSets<ServerPlayer> pooledLinkedPlayerHashSets = new com.destroystokyo.paper.util.misc.PooledLinkedHashSets<>();
+    // Paper start - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
+    // A note about the naming used here:
+    // Previously, mojang used a "spawn range" of 8 for controlling both ticking and
+    // mob spawn range. However, spigot makes the spawn range configurable by
+    // checking if the chunk is in the tick range (8) and the spawn range
+    // obviously this means a spawn range > 8 cannot be implemented
+
+    // these maps are named after spigot's uses
+    public final com.destroystokyo.paper.util.misc.PlayerAreaMap playerMobSpawnMap; // this map is absent from updateMaps since it's controlled at the start of the chunkproviderserver tick
+    public final com.destroystokyo.paper.util.misc.PlayerAreaMap playerChunkTickRangeMap;
+    // Paper end - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
 
     void addPlayerToDistanceMaps(ServerPlayer player) {
         int chunkX = MCUtil.getChunkCoordinate(player.getX());
         int chunkZ = MCUtil.getChunkCoordinate(player.getZ());
         // Note: players need to be explicitly added to distance maps before they can be updated
+        this.playerChunkTickRangeMap.add(player, chunkX, chunkZ, DistanceManager.MOB_SPAWN_RANGE); // Paper - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
         // Paper start - per player mob spawning
         if (this.playerMobDistanceMap != null) {
             this.playerMobDistanceMap.add(player, chunkX, chunkZ, this.distanceManager.getSimulationDistance());
@@ -191,6 +203,10 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     void removePlayerFromDistanceMaps(ServerPlayer player) {
 
+        // Paper start - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
+        this.playerMobSpawnMap.remove(player);
+        this.playerChunkTickRangeMap.remove(player);
+        // Paper end - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
         // Paper start - per player mob spawning
         if (this.playerMobDistanceMap != null) {
             this.playerMobDistanceMap.remove(player);
@@ -202,6 +218,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         int chunkX = MCUtil.getChunkCoordinate(player.getX());
         int chunkZ = MCUtil.getChunkCoordinate(player.getZ());
         // Note: players need to be explicitly added to distance maps before they can be updated
+        this.playerChunkTickRangeMap.update(player, chunkX, chunkZ, DistanceManager.MOB_SPAWN_RANGE); // Paper - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
         // Paper start - per player mob spawning
         if (this.playerMobDistanceMap != null) {
             this.playerMobDistanceMap.update(player, chunkX, chunkZ, this.distanceManager.getSimulationDistance());
@@ -281,6 +298,38 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         this.regionManagers.add(this.dataRegionManager);
         // Paper end
         this.playerMobDistanceMap = this.level.paperConfig.perPlayerMobSpawns ? new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets) : null; // Paper
+        // Paper start - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
+        this.playerChunkTickRangeMap = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets,
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInChunkTickRange = newState;
+                }
+            },
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInChunkTickRange = newState;
+                }
+            });
+        this.playerMobSpawnMap = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets,
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInMobSpawnRange = newState;
+                }
+            },
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInMobSpawnRange = newState;
+                }
+            });
+        // Paper end - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
     }
 
     protected ChunkGenerator generator() {
@@ -501,6 +550,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
                 holder = (ChunkHolder) this.pendingUnloads.remove(pos);
                 if (holder != null) {
                     holder.setTicketLevel(level);
+                    holder.onChunkAdd(); // Paper - optimise anyPlayerCloseEnoughForSpawning - PUT HERE AFTER RE-ADDING ONLY
                 } else {
                     holder = new ChunkHolder(new ChunkPos(pos), level, this.level, this.lightEngine, this.queueSorter, this);
                     // Paper start
@@ -600,6 +650,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
             ChunkHolder playerchunk = (ChunkHolder) this.updatingChunkMap.remove(j);
 
             if (playerchunk != null) {
+                playerchunk.onChunkRemove(); // Paper
                 this.pendingUnloads.put(j, playerchunk);
                 this.modified = true;
                 this.scheduleUnload(j, playerchunk); // Paper - Move up - don't leak chunks
@@ -1331,43 +1382,48 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         return this.anyPlayerCloseEnoughForSpawning(pos, false);
     }
 
-    boolean anyPlayerCloseEnoughForSpawning(ChunkPos chunkcoordintpair, boolean reducedRange) {
-        int chunkRange = level.spigotConfig.mobSpawnRange;
-        chunkRange = (chunkRange > level.spigotConfig.viewDistance) ? (byte) level.spigotConfig.viewDistance : chunkRange;
-        chunkRange = (chunkRange > 8) ? 8 : chunkRange;
-
-        final int finalChunkRange = chunkRange; // Paper for lambda below
-        //double blockRange = (reducedRange) ? Math.pow(chunkRange << 4, 2) : 16384.0D; // Paper - use from event
-        double blockRange = 16384.0D; // Paper
-        // Spigot end
-        long i = chunkcoordintpair.toLong();
+    // Paper start - optimise anyPlayerCloseEnoughForSpawning
+    final boolean anyPlayerCloseEnoughForSpawning(ChunkPos chunkcoordintpair, boolean reducedRange) {
+        return this.anyPlayerCloseEnoughForSpawning(this.getUpdatingChunkIfPresent(chunkcoordintpair.toLong()), chunkcoordintpair, reducedRange);
+    }
 
-        if (!this.distanceManager.hasPlayersNearby(i)) {
+    final boolean anyPlayerCloseEnoughForSpawning(ChunkHolder playerchunk, ChunkPos chunkcoordintpair, boolean reducedRange) {
+        // this function is so hot that removing the map lookup call can have an order of magnitude impact on its performance
+        // tested and confirmed via System.nanoTime()
+        com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInRange = reducedRange ? playerchunk.playersInMobSpawnRange : playerchunk.playersInChunkTickRange;
+        if (playersInRange == null) {
             return false;
-        } else {
-            Iterator iterator = this.playerMap.getPlayers(i).iterator();
-
-            ServerPlayer entityplayer;
+        }
+        Object[] backingSet = playersInRange.getBackingSet();
 
-            do {
-                if (!iterator.hasNext()) {
-                    return false;
+        if (reducedRange) {
+            for (int i = 0, len = backingSet.length; i < len; ++i) {
+                Object raw = backingSet[i];
+                if (!(raw instanceof ServerPlayer player)) {
+                    continue;
                 }
-
-                entityplayer = (ServerPlayer) iterator.next();
-                // Paper start - add PlayerNaturallySpawnCreaturesEvent
-                com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent event;
-                blockRange = 16384.0D;
-                if (reducedRange) {
-                    event = entityplayer.playerNaturallySpawnedEvent;
-                    if (event == null || event.isCancelled()) return false;
-                    blockRange = (double) ((event.getSpawnRadius() << 4) * (event.getSpawnRadius() << 4));
+                // don't check spectator and whatnot, already handled by mob spawn map update
+                if (euclideanDistanceSquared(chunkcoordintpair, player) < player.lastEntitySpawnRadiusSquared) {
+                    return true; // in range
                 }
-                // Paper end
-            } while (!this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair, blockRange)); // Spigot
-
-            return true;
+            }
+        } else {
+            final double range = (DistanceManager.MOB_SPAWN_RANGE * 16) * (DistanceManager.MOB_SPAWN_RANGE * 16);
+            // before spigot, mob spawn range was actually mob spawn range + tick range, but it was split
+            for (int i = 0, len = backingSet.length; i < len; ++i) {
+                Object raw = backingSet[i];
+                if (!(raw instanceof ServerPlayer player)) {
+                    continue;
+                }
+                // don't check spectator and whatnot, already handled by mob spawn map update
+                if (euclideanDistanceSquared(chunkcoordintpair, player) < range) {
+                    return true; // in range
+                }
+            }
         }
+        // no players in range
+        return false;
+        // Paper end - optimise anyPlayerCloseEnoughForSpawning
     }
 
     public List<ServerPlayer> getPlayersCloseForSpawning(ChunkPos pos) {
diff --git a/src/main/java/net/minecraft/server/level/DistanceManager.java b/src/main/java/net/minecraft/server/level/DistanceManager.java
index 75f11490737018096e7645ce0b991fd210c8f596..14774d51dd35a98471d29230a64fadee74651d19 100644
--- a/src/main/java/net/minecraft/server/level/DistanceManager.java
+++ b/src/main/java/net/minecraft/server/level/DistanceManager.java
@@ -48,7 +48,7 @@ public abstract class DistanceManager {
     final Long2ObjectMap<ObjectSet<ServerPlayer>> playersPerChunk = new Long2ObjectOpenHashMap();
     public final Long2ObjectOpenHashMap<SortedArraySet<Ticket<?>>> tickets = new Long2ObjectOpenHashMap();
     private final DistanceManager.ChunkTicketTracker ticketTracker = new DistanceManager.ChunkTicketTracker();
-    private final DistanceManager.FixedPlayerDistanceChunkTracker naturalSpawnChunkCounter = new DistanceManager.FixedPlayerDistanceChunkTracker(8);
+    public static final int MOB_SPAWN_RANGE = 8; // private final ChunkMapDistance.b f = new ChunkMapDistance.b(8); // Paper - no longer used
     private final TickingTracker tickingTicketsTracker = new TickingTracker();
     private final DistanceManager.PlayerTicketTracker playerTicketManager = new DistanceManager.PlayerTicketTracker(33);
     // Paper start use a queue, but still keep unique requirement
@@ -139,7 +139,7 @@ public abstract class DistanceManager {
     protected abstract ChunkHolder updateChunkScheduling(long pos, int level, @Nullable ChunkHolder holder, int k);
 
     public boolean runAllUpdates(ChunkMap chunkStorage) {
-        this.naturalSpawnChunkCounter.runAllUpdates();
+        //this.f.a(); // Paper - no longer used
         this.tickingTicketsTracker.runAllUpdates();
         this.playerTicketManager.runAllUpdates();
         int i = Integer.MAX_VALUE - this.ticketTracker.runDistanceUpdates(Integer.MAX_VALUE);
@@ -286,7 +286,7 @@ public abstract class DistanceManager {
         ((ObjectSet) this.playersPerChunk.computeIfAbsent(i, (j) -> {
             return new ObjectOpenHashSet();
         })).add(player);
-        this.naturalSpawnChunkCounter.update(i, 0, true);
+        //this.f.update(i, 0, true); // Paper - no longer used
         this.playerTicketManager.update(i, 0, true);
         this.tickingTicketsTracker.addTicket(TicketType.PLAYER, chunkcoordintpair, this.getPlayerTicketLevel(), chunkcoordintpair);
     }
@@ -300,7 +300,7 @@ public abstract class DistanceManager {
         if (objectset != null) objectset.remove(player); // Paper - some state corruption happens here, don't crash, clean up gracefully.
         if (objectset == null || objectset.isEmpty()) { // Paper
             this.playersPerChunk.remove(i);
-            this.naturalSpawnChunkCounter.update(i, Integer.MAX_VALUE, false);
+            //this.f.update(i, Integer.MAX_VALUE, false); // Paper - no longer used
             this.playerTicketManager.update(i, Integer.MAX_VALUE, false);
             this.tickingTicketsTracker.removeTicket(TicketType.PLAYER, chunkcoordintpair, this.getPlayerTicketLevel(), chunkcoordintpair);
         }
@@ -344,13 +344,17 @@ public abstract class DistanceManager {
     // Paper end
 
     public int getNaturalSpawnChunkCount() {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        return this.naturalSpawnChunkCounter.chunks.size();
+        // Paper start - use distance map to implement
+        // note: this is the spawn chunk count
+        return this.chunkMap.playerChunkTickRangeMap.size();
+        // Paper end - use distance map to implement
     }
 
     public boolean hasPlayersNearby(long chunkPos) {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        return this.naturalSpawnChunkCounter.chunks.containsKey(chunkPos);
+        // Paper start - use distance map to implement
+        // note: this is the is spawn chunk method
+        return this.chunkMap.playerChunkTickRangeMap.getObjectsInRange(chunkPos) != null;
+        // Paper end - use distance map to implement
     }
 
     public String getDebugStatus() {
diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
index 8cfd38617b49ea6be318abc819f2ed5b7dabd2e1..59cd2b8ecdd2c962a027526fe45032559aa2ee8c 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -881,6 +881,37 @@ public class ServerChunkCache extends ChunkSource {
         if (flag) {
             this.chunkMap.tick();
         } else {
+            // Paper start - optimize isOutisdeRange
+            ChunkMap playerChunkMap = this.chunkMap;
+            for (ServerPlayer player : this.level.players) {
+                if (!player.affectsSpawning || player.isSpectator()) {
+                    playerChunkMap.playerMobSpawnMap.remove(player);
+                    continue;
+                }
+
+                int viewDistance = this.chunkMap.getEffectiveViewDistance();
+
+                // copied and modified from isOutisdeRange
+                int chunkRange = level.spigotConfig.mobSpawnRange;
+                chunkRange = (chunkRange > viewDistance) ? (byte)viewDistance : chunkRange;
+                chunkRange = (chunkRange > DistanceManager.MOB_SPAWN_RANGE) ? DistanceManager.MOB_SPAWN_RANGE : chunkRange;
+
+                com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent event = new com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent(player.getBukkitEntity(), (byte)chunkRange);
+                event.callEvent();
+                if (event.isCancelled() || event.getSpawnRadius() < 0 || playerChunkMap.playerChunkTickRangeMap.getLastViewDistance(player) == -1) {
+                    playerChunkMap.playerMobSpawnMap.remove(player);
+                    continue;
+                }
+
+                int range = Math.min(event.getSpawnRadius(), 32); // limit to max view distance
+                int chunkX = net.minecraft.server.MCUtil.getChunkCoordinate(player.getX());
+                int chunkZ = net.minecraft.server.MCUtil.getChunkCoordinate(player.getZ());
+
+                playerChunkMap.playerMobSpawnMap.addOrUpdate(player, chunkX, chunkZ, range);
+                player.lastEntitySpawnRadiusSquared = (double)((range << 4) * (range << 4)); // used in anyPlayerCloseEnoughForSpawning
+                player.playerNaturallySpawnedEvent = event;
+            }
+            // Paper end - optimize isOutisdeRange
             LevelData worlddata = this.level.getLevelData();
             ProfilerFiller gameprofilerfiller = this.level.getProfiler();
 
@@ -924,15 +955,7 @@ public class ServerChunkCache extends ChunkSource {
             boolean flag2 = this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBSPAWNING) && !this.level.players().isEmpty(); // CraftBukkit
 
             Collections.shuffle(list);
-            // Paper start - call player naturally spawn event
-            int chunkRange = level.spigotConfig.mobSpawnRange;
-            chunkRange = (chunkRange > level.spigotConfig.viewDistance) ? (byte) level.spigotConfig.viewDistance : chunkRange;
-            chunkRange = Math.min(chunkRange, 8);
-            for (ServerPlayer entityPlayer : this.level.players()) {
-                entityPlayer.playerNaturallySpawnedEvent = new com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent(entityPlayer.getBukkitEntity(), (byte) chunkRange);
-                entityPlayer.playerNaturallySpawnedEvent.callEvent();
-            };
-            // Paper end
+            // Paper - moved natural spawn event up
             Iterator iterator1 = list.iterator();
 
             while (iterator1.hasNext()) {
@@ -940,9 +963,9 @@ public class ServerChunkCache extends ChunkSource {
                 LevelChunk chunk1 = chunkproviderserver_a.chunk;
                 ChunkPos chunkcoordintpair = chunk1.getPos();
 
-                if (this.level.isPositionEntityTicking(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair)) {
+                if (this.level.isPositionEntityTicking(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkproviderserver_a.holder, chunkcoordintpair, false)) { // Paper - optimise anyPlayerCloseEnoughForSpawning
                     chunk1.incrementInhabitedTime(j);
-                    if (flag2 && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair, true)) { // Spigot
+                    if (flag2 && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkproviderserver_a.holder, chunkcoordintpair, true)) { // Spigot // Paper - optimise anyPlayerCloseEnoughForSpawning
                         NaturalSpawner.spawnForChunk(this.level, chunk1, spawnercreature_d, this.spawnFriendlies, this.spawnEnemies, flag1);
                     }
 
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index beebb7a0e6b8b1fa4e7d2f9fdf1962357cc2ebc3..2f13055a39c26fe12d2c1094103186635e536166 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -253,6 +253,7 @@ public class ServerPlayer extends Player {
     // CraftBukkit end
     public PlayerNaturallySpawnCreaturesEvent playerNaturallySpawnedEvent; // Paper
 
+    public double lastEntitySpawnRadiusSquared; // Paper - optimise isOutsideRange, this field is in blocks
     public final com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> cachedSingleHashSet; // Paper
 
     public ServerPlayer(MinecraftServer server, ServerLevel world, GameProfile profile) {
