From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: violetc <58360096+s-yh-china@users.noreply.github.com>
Date: Sun, 14 Aug 2022 00:00:51 +0800
Subject: [PATCH] Dont send useless entity packets

This patch is Powered by Purpur(https://github.com/PurpurMC/Purpur)

diff --git a/net/minecraft/server/level/ServerEntity.java b/net/minecraft/server/level/ServerEntity.java
index 0fb253aa55a24b56b17f524b3261c5b75c7d7e59..f2974a0f49711d17c349fdfa8f57d3a4706ff0ca 100644
--- a/net/minecraft/server/level/ServerEntity.java
+++ b/net/minecraft/server/level/ServerEntity.java
@@ -186,6 +186,11 @@ public class ServerEntity {
                     } else if (flag) {
                         packet = new ClientboundMoveEntityPacket.Rot(this.entity.getId(), b, b1, this.entity.onGround());
                         flag4 = true;
+                        // Leaves start - dont send useless entity packets
+                        if (org.leavesmc.leaves.LeavesConfig.performance.dontSendUselessEntityPackets && isUselessPacket(packet)) {
+                            packet = null;
+                        }
+                        // Leaves end - dont send useless entity packets
                     }
                 } else {
                     packet = new ClientboundMoveEntityPacket.PosRot(this.entity.getId(), (short)l, (short)l1, (short)l2, b, b1, this.entity.onGround());
@@ -302,6 +307,21 @@ public class ServerEntity {
         return currentPassengers.stream().filter(entity -> !initialPassengers.contains(entity));
     }
 
+    // Leaves start - dont send useless entity packets
+    private boolean isUselessPacket(Packet<?> possibleUselessPacket) {
+        if (possibleUselessPacket instanceof ClientboundMoveEntityPacket packet) {
+            if (possibleUselessPacket instanceof ClientboundMoveEntityPacket.Pos) {
+                return packet.getXa() == 0 && packet.getYa() == 0 && packet.getZa() == 0;
+            } else if (possibleUselessPacket instanceof ClientboundMoveEntityPacket.PosRot) {
+                return packet.getXa() == 0 && packet.getYa() == 0 && packet.getZa() == 0 && packet.getyRot() == 0 && packet.getxRot() == 0;
+            } else if (possibleUselessPacket instanceof ClientboundMoveEntityPacket.Rot) {
+                return packet.getyRot() == 0 && packet.getxRot() == 0;
+            }
+        }
+        return false;
+    }
+    // Leaves end - dont send useless entity packets
+
     public void removePairing(ServerPlayer player) {
         this.entity.stopSeenByPlayer(player);
         player.connection.send(new ClientboundRemoveEntitiesPacket(this.entity.getId()));