From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Thu, 6 Jul 2023 20:17:37 -0700
Subject: [PATCH] Optimize player lookups for beacons

For larger ranges, it's better to iterate over the player list
than the entity slices.

diff --git a/src/main/java/net/minecraft/world/level/block/entity/BeaconBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/BeaconBlockEntity.java
index 2f12a1054c9c9e311e02dc5c3244ad3688db15ba..45e3a4f09a0e515932d08f52e7d07cf8f6014fb6 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/BeaconBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/BeaconBlockEntity.java
@@ -329,7 +329,16 @@ public class BeaconBlockEntity extends BlockEntity implements MenuProvider, Name
             double d0 = blockEntity != null ? blockEntity.getEffectRange() : (i * 10 + 10);// Paper - custom beacon ranges
 
             AABB axisalignedbb = (new AABB(blockposition)).inflate(d0).expandTowards(0.0D, (double) world.getHeight(), 0.0D);
-            List<Player> list = world.getEntitiesOfClass(Player.class, axisalignedbb);
+            // Paper start - optimize player lookup for beacons
+            List<Player> list;
+            if (d0 <= 128.0) {
+                list = world.getEntitiesOfClass(Player.class, axisalignedbb);
+            } else {
+                list = (List)world.getNearbyPlayers(null, (double)blockposition.getX() + 0.5, (double)blockposition.getY() + 0.5, (double)blockposition.getZ() + 0.5, -1.0, (net.minecraft.world.entity.Entity entity) -> {
+                    return !entity.isSpectator() && entity.getBoundingBox().intersects(axisalignedbb);
+                });
+            }
+            // Paper end - optimize player lookup for beacons
 
             return list;
         }