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/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index 8ea2f24695f5dad55e21f238b69442513e7a90c6..0846e11c82295ccf93683f877962ec7804dad677 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -212,6 +212,11 @@ public class ServerEntity {
                     packet1 = new ClientboundTeleportEntityPacket(this.entity);
                     flag4 = true;
                     flag5 = true;
+                    // Leaves start - dont send useless entity packets
+                    if (org.leavesmc.leaves.LeavesConfig.dontSendUselessEntityPackets && isUselessPacket(packet1)) {
+                        packet1 = null;
+                    }
+                    // Leaves end - dont send useless entity packets
                 }
 
                 if ((this.trackDelta || this.entity.hasImpulse || this.entity instanceof LivingEntity && ((LivingEntity) this.entity).isFallFlying()) && this.tickCount > 0) {
@@ -294,6 +299,21 @@ public class ServerEntity {
         });
     }
 
+    // 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(new int[]{this.entity.getId()}));