Paper/patches/server/0887-Only-tick-item-frames-if-players-can-see-it.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Redned <redned235@gmail.com>
Date: Mon, 19 Jun 2023 15:45:53 -0500
Subject: [PATCH] Only tick item frames if players can see it

In the event that an item frame cannot be seen by any players, ticking the item frame every tick is unnecessary. This can be a very hot section of the entity tracker when lots of item frames are present on a server, so this reduces the logic which speeds it up.

diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index b52f86e23a35f8727d827155ebb20f847108d673..72e7c44946ef02fcb744f2a4d265706e21b33c10 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -111,7 +111,7 @@ public class ServerEntity {
 
         Entity entity = this.entity;
 
-        if (entity instanceof ItemFrame) {
+        if (!this.trackedPlayers.isEmpty() && entity instanceof ItemFrame) { // Paper - Perf: Only tick item frames if players can see it
             ItemFrame entityitemframe = (ItemFrame) entity;
 
             if (true || this.tickCount % 10 == 0) { // CraftBukkit - Moved below, should always enter this block