From f49f90906c76f4581b1caa225ee841fd60b1c04d Mon Sep 17 00:00:00 2001
From: Tiger Wang <ziwei.tiger@outlook.com>
Date: Tue, 21 Apr 2020 23:16:28 +0100
Subject: [PATCH] Reduced packet spam when entities idle

* Try not to send look packets when nothing's changed.
---
 src/Entities/Entity.cpp       |  4 ++--
 src/Mobs/Monster.cpp          | 10 +++++++++-
 src/Protocol/Protocol_1_9.cpp |  2 +-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/Entities/Entity.cpp b/src/Entities/Entity.cpp
index 5c444f74a..ae468d25c 100644
--- a/src/Entities/Entity.cpp
+++ b/src/Entities/Entity.cpp
@@ -39,8 +39,8 @@ cEntity::cEntity(eEntityType a_EntityType, Vector3d a_Pos, double a_Width, doubl
 	m_MaxHealth(1),
 	m_AttachedTo(nullptr),
 	m_Attachee(nullptr),
-	m_bDirtyHead(true),
-	m_bDirtyOrientation(true),
+	m_bDirtyHead(false),
+	m_bDirtyOrientation(false),
 	m_bHasSentNoSpeed(true),
 	m_bOnGround(false),
 	m_Gravity(-9.81f),
diff --git a/src/Mobs/Monster.cpp b/src/Mobs/Monster.cpp
index 75bda197f..1c3b3a45e 100644
--- a/src/Mobs/Monster.cpp
+++ b/src/Mobs/Monster.cpp
@@ -490,14 +490,22 @@ void cMonster::CalcLeashActions(std::chrono::milliseconds a_Dt)
 void cMonster::SetPitchAndYawFromDestination(bool a_IsFollowingPath)
 {
 	Vector3d BodyDistance;
-	if (!a_IsFollowingPath && (GetTarget() != nullptr))
+	if (!a_IsFollowingPath)
 	{
+		if (GetTarget() == nullptr)
+		{
+			// Avoid dirtying head position when nothing will change
+			// Thus avoids creating unnecessary network traffic
+			return;
+		}
+
 		BodyDistance = GetTarget()->GetPosition() - GetPosition();
 	}
 	else
 	{
 		BodyDistance = m_NextWayPointPosition - GetPosition();
 	}
+
 	double BodyRotation, BodyPitch;
 	BodyDistance.Normalize();
 	VectorToEuler(BodyDistance.x, BodyDistance.y, BodyDistance.z, BodyRotation, BodyPitch);
diff --git a/src/Protocol/Protocol_1_9.cpp b/src/Protocol/Protocol_1_9.cpp
index dfa371a62..8327eaf40 100644
--- a/src/Protocol/Protocol_1_9.cpp
+++ b/src/Protocol/Protocol_1_9.cpp
@@ -446,8 +446,8 @@ void cProtocol_1_9_0::SendSpawnMob(const cMonster & a_Mob)
 	Pkt.WriteBEDouble(LastSentPos.x);
 	Pkt.WriteBEDouble(LastSentPos.y);
 	Pkt.WriteBEDouble(LastSentPos.z);
+	Pkt.WriteByteAngle(a_Mob.GetHeadYaw());  // Doesn't seem to be used
 	Pkt.WriteByteAngle(a_Mob.GetPitch());
-	Pkt.WriteByteAngle(a_Mob.GetHeadYaw());
 	Pkt.WriteByteAngle(a_Mob.GetYaw());
 	Pkt.WriteBEInt16(static_cast<Int16>(a_Mob.GetSpeedX() * 400));
 	Pkt.WriteBEInt16(static_cast<Int16>(a_Mob.GetSpeedY() * 400));