SparklyPaperMC/patches/server/0004-Skip-distanceToSqr-call-in-ServerEntity-sendChanges-.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrPowerGamerBR <git@mrpowergamerbr.com>
Date: Wed, 15 Nov 2023 23:39:36 -0300
Subject: [PATCH] Skip "distanceToSqr" call in "ServerEntity#sendChanges" if
 the delta movement hasn't changed

The "distanceToSqr" call is a bit expensive, so avoiding it is pretty nice, around ~15% calls are skipped with this check

We could also check if the x,y,z coordinates are equal, but for now, let's just keep the identity check, which also helps us since Minecraft's code does reuse the original delta movement Vec3 object

diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index e8781c8857d4b8b241515c811a4686feda437abb..aafa06b3730fa3826941cbec7177b58fbd672040 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -229,6 +229,7 @@ public class ServerEntity {
 
                 if ((this.trackDelta || this.entity.hasImpulse || this.entity instanceof LivingEntity && ((LivingEntity) this.entity).isFallFlying()) && this.tickCount > 0) {
                     Vec3 vec3d1 = this.entity.getDeltaMovement();
+                    if (vec3d1 != this.lastSentMovement) { // SparklyPaper start - skip distanceToSqr call in ServerEntity#sendChanges if the delta movement hasn't changed
                     double d0 = vec3d1.distanceToSqr(this.lastSentMovement);
 
                     if (d0 > 1.0E-7D || d0 > 0.0D && vec3d1.lengthSqr() == 0.0D) {
@@ -243,6 +244,7 @@ public class ServerEntity {
                             this.broadcast.accept(new ClientboundSetEntityMotionPacket(this.entity.getId(), this.lastSentMovement));
                         }
                     }
+                    } // SparklyPaper end
                 }
 
                 if (packet1 != null) {