From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "Sofiane H. Djerbi" <46628754+kugge@users.noreply.github.com>
Date: Thu, 16 Feb 2023 01:49:54 +0200
Subject: [PATCH] Send null entity packets

This is from Purpur. Don't send null entity packets.

diff --git a/src/main/java/dev/kaiijumc/kaiiju/KaiijuConfig.java b/src/main/java/dev/kaiijumc/kaiiju/KaiijuConfig.java
index fa829cef4033625470dfae29ddf777e6c5ab8c55..47e23a196ae5e44600a64184b69141c00235baca 100644
--- a/src/main/java/dev/kaiijumc/kaiiju/KaiijuConfig.java
+++ b/src/main/java/dev/kaiijumc/kaiiju/KaiijuConfig.java
@@ -203,7 +203,10 @@ public class KaiijuConfig {
         else
             linearFlushThreads = Math.max(linearFlushThreads, 1);
     }
+    
+    public static boolean sendNullEntityPackets = true;
 
     private static void networkSettings() {
+        sendNullEntityPackets = getBoolean("network.send-null-entity-packets", sendNullEntityPackets);
     }
 }
diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index 81d0b2933040a451441f660f9e46199ae3b111e3..cdbc4be679d7e096c1005eaf84b74c4877479c43 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -201,6 +201,11 @@ public class ServerEntity {
                         flag4 = true;
                         flag5 = true;
                     }
+                    // Kaiiju start - Don't send null move entity packets
+                    if (!dev.kaiijumc.kaiiju.KaiijuConfig.sendNullEntityPackets && isNullMovePacket(packet1)) {
+                        packet1 = null;
+                    }
+                    // Kaiiju end
                 }
 
                 if ((this.trackDelta || this.entity.hasImpulse || this.entity instanceof LivingEntity && ((LivingEntity) this.entity).isFallFlying()) && this.tickCount > 0) {
@@ -273,6 +278,20 @@ public class ServerEntity {
         });
     }
 
+    // Kaiiju start - Don't send null move entity packets
+    private boolean isNullMovePacket(Packet<?> packet) {
+        if (packet instanceof ClientboundMoveEntityPacket move) {
+            if (packet instanceof ClientboundMoveEntityPacket.Pos)
+                return move.getXa() == 0 && move.getYa() == 0 && move.getZa() == 0;
+            if (packet instanceof ClientboundMoveEntityPacket.PosRot)
+                return move.getXa() == 0 && move.getYa() == 0 && move.getZa() == 0 && move.getyRot() == 0 && move.getxRot() == 0;
+            if (packet instanceof ClientboundMoveEntityPacket.Rot)
+                return move.getyRot() == 0 && move.getxRot() == 0;
+        }
+        return false;
+    }
+    // Kaiiju end
+
     public void removePairing(ServerPlayer player) {
         this.entity.stopSeenByPlayer(player);
         player.connection.send(new ClientboundRemoveEntitiesPacket(new int[]{this.entity.getId()}));