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 b7fd8e70413c38923d0719aff803449e392383ac..209685e67ebdb7f062bb58118242dcbf884a3876 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -198,6 +198,7 @@ public class ServerEntity {
                             flag4 = true;
                             flag5 = true;
                         }
+                        // Leaves end - Better checking
                     } else {
                         this.wasOnGround = this.entity.isOnGround();
                         this.teleportDelay = 0;
@@ -205,6 +206,11 @@ public class ServerEntity {
                         flag4 = true;
                         flag5 = true;
                     }
+                    // Leaves start - dont send useless entity packets
+                    if (top.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) {
@@ -279,6 +285,21 @@ 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()}));
diff --git a/src/main/java/top/leavesmc/leaves/LeavesConfig.java b/src/main/java/top/leavesmc/leaves/LeavesConfig.java
index 170f1f964e5cd3d1f1590106e31718dced04d0ef..76c382c839b904640cb92afa503d1aef1c29ffc6 100644
--- a/src/main/java/top/leavesmc/leaves/LeavesConfig.java
+++ b/src/main/java/top/leavesmc/leaves/LeavesConfig.java
@@ -236,6 +236,11 @@ public final class LeavesConfig {
         }
     }
 
+    public static boolean dontSendUselessEntityPackets = true;
+    private static void dontSendUselessEntityPackets() {
+        dontSendUselessEntityPackets = getBoolean("settings.performance.dont-send-useless-entity-packets", dontSendUselessEntityPackets);
+    }
+
     public static final class WorldConfig {
 
         public final String worldName;