6 files changed, 56 insertions, 38 deletions

diff --git a/src/ByteBuffer.cpp b/src/ByteBuffer.cpp
index 46f2ba0d4..8121fc3ef 100644
--- a/src/ByteBuffer.cpp
+++ b/src/ByteBuffer.cpp
@@ -214,6 +214,24 @@ size_t cByteBuffer::GetReadableSpace(void) const
 
 
 
+bool cByteBuffer::CanBEInt8Represent(int a_Value)
+{
+	return (-128 <= a_Value) && (a_Value <= 127);
+}
+
+
+
+
+
+bool cByteBuffer::CanBEInt16Represent(int a_Value)
+{
+	return (-32768 <= a_Value) && (a_Value <= 32767);
+}
+
+
+
+
+
 bool cByteBuffer::CanReadBytes(size_t a_Count) const
 {
 	CHECK_THREAD
diff --git a/src/ByteBuffer.h b/src/ByteBuffer.h
index 1d108fca2..664887132 100644
--- a/src/ByteBuffer.h
+++ b/src/ByteBuffer.h
@@ -31,6 +31,7 @@ their own synchronization.
 class cByteBuffer
 {
 public:
+
 	cByteBuffer(size_t a_BufferSize);
 	~cByteBuffer();
 
@@ -47,7 +48,13 @@ public:
 	size_t GetReadableSpace(void) const;
 
 	/** Returns the current data start index. For debugging purposes. */
-	size_t  GetDataStart(void) const { return m_DataStart; }
+	size_t GetDataStart(void) const { return m_DataStart; }
+
+	/** Returns if the given value can fit in a protocol big-endian 8 bit integer. */
+	static bool CanBEInt8Represent(int a_Value);
+
+	/** Returns if the given value can fit in a protocol big-endian 16 bit integer. */
+	static bool CanBEInt16Represent(int a_Value);
 
 	/** Returns true if the specified amount of bytes are available for reading */
 	bool CanReadBytes(size_t a_Count) const;
diff --git a/src/Entities/Entity.cpp b/src/Entities/Entity.cpp
index 0718da06c..c46f9e644 100644
--- a/src/Entities/Entity.cpp
+++ b/src/Entities/Entity.cpp
@@ -1970,7 +1970,7 @@ void cEntity::BroadcastMovementUpdate(const cClientHandle * a_Exclude)
 		return;
 	}
 
-	if (GetSpeed().SqrLength() > 0.001)
+	if (m_Speed.HasNonZeroLength())
 	{
 		// Movin'
 		m_World->BroadcastEntityVelocity(*this, a_Exclude);
@@ -1986,8 +1986,7 @@ void cEntity::BroadcastMovementUpdate(const cClientHandle * a_Exclude)
 		m_bHasSentNoSpeed = true;
 	}
 
-	Vector3i Diff = (GetPosition() * 32.0).Floor() - (m_LastSentPosition * 32.0).Floor();
-	if (Diff.HasNonZeroLength())  // Have we moved?
+	if ((m_Position - m_LastSentPosition).HasNonZeroLength())  // Have we moved?
 	{
 		m_World->BroadcastEntityPosition(*this, a_Exclude);
 
diff --git a/src/Protocol/Protocol_1_8.cpp b/src/Protocol/Protocol_1_8.cpp
index e949d6116..d56375a8d 100644
--- a/src/Protocol/Protocol_1_8.cpp
+++ b/src/Protocol/Protocol_1_8.cpp
@@ -579,12 +579,15 @@ void cProtocol_1_8_0::SendEntityPosition(const cEntity & a_Entity)
 {
 	ASSERT(m_State == 3);  // In game mode?
 
-	const auto Delta = (a_Entity.GetPosition() - a_Entity.GetLastSentPosition()) * 32;
+	const auto Delta = (a_Entity.GetPosition() * 32).Floor() - (a_Entity.GetLastSentPosition() * 32).Floor();
 
-	// Limitations of a byte
-	static const auto Max = std::numeric_limits<Int8>::max();
-
-	if ((std::abs(Delta.x) <= Max) && (std::abs(Delta.y) <= Max) && (std::abs(Delta.z) <= Max))
+	// Ensure that the delta has enough precision and is within range of a BEInt8:
+	if (
+		Delta.HasNonZeroLength() &&
+		cByteBuffer::CanBEInt8Represent(Delta.x) &&
+		cByteBuffer::CanBEInt8Represent(Delta.y) &&
+		cByteBuffer::CanBEInt8Represent(Delta.z)
+	)
 	{
 		const auto Move = static_cast<Vector3<Int8>>(Delta);
 
@@ -613,8 +616,16 @@ void cProtocol_1_8_0::SendEntityPosition(const cEntity & a_Entity)
 		return;
 	}
 
-	// Too big a movement, do a teleport
-	SendEntityTeleport(a_Entity);
+	// Too big or small a movement, do a teleport.
+
+	cPacketizer Pkt(*this, pktTeleportEntity);
+	Pkt.WriteVarInt32(a_Entity.GetUniqueID());
+	Pkt.WriteFPInt(a_Entity.GetPosX());
+	Pkt.WriteFPInt(a_Entity.GetPosY());
+	Pkt.WriteFPInt(a_Entity.GetPosZ());
+	Pkt.WriteByteAngle(a_Entity.GetYaw());
+	Pkt.WriteByteAngle(a_Entity.GetPitch());
+	Pkt.WriteBool(a_Entity.IsOnGround());
 }
 
 
@@ -4202,22 +4213,6 @@ void cProtocol_1_8_0::HandlePacket(cByteBuffer & a_Buffer)
 
 
 
-void cProtocol_1_8_0::SendEntityTeleport(const cEntity & a_Entity)
-{
-	cPacketizer Pkt(*this, pktTeleportEntity);
-	Pkt.WriteVarInt32(a_Entity.GetUniqueID());
-	Pkt.WriteFPInt(a_Entity.GetPosX());
-	Pkt.WriteFPInt(a_Entity.GetPosY());
-	Pkt.WriteFPInt(a_Entity.GetPosZ());
-	Pkt.WriteByteAngle(a_Entity.GetYaw());
-	Pkt.WriteByteAngle(a_Entity.GetPitch());
-	Pkt.WriteBool(a_Entity.IsOnGround());
-}
-
-
-
-
-
 void cProtocol_1_8_0::StartEncryption(const Byte * a_Key)
 {
 	m_Encryptor.Init(a_Key, a_Key);
diff --git a/src/Protocol/Protocol_1_8.h b/src/Protocol/Protocol_1_8.h
index eaa8813be..ed13399ef 100644
--- a/src/Protocol/Protocol_1_8.h
+++ b/src/Protocol/Protocol_1_8.h
@@ -270,10 +270,5 @@ private:
 	/** Handle a complete packet stored in the given buffer. */
 	void HandlePacket(cByteBuffer & a_Buffer);
 
-	/** Sends an entity teleport packet.
-	Mitigates a 1.8 bug where the position in the entity spawn packet is ignored,
-	and so entities don't show up until a teleport is sent. */
-	void SendEntityTeleport(const cEntity & a_Entity);
-
 	void StartEncryption(const Byte * a_Key);
 } ;
diff --git a/src/Protocol/Protocol_1_9.cpp b/src/Protocol/Protocol_1_9.cpp
index dd2133f77..9a4bcdc4a 100644
--- a/src/Protocol/Protocol_1_9.cpp
+++ b/src/Protocol/Protocol_1_9.cpp
@@ -307,12 +307,15 @@ void cProtocol_1_9_0::SendEntityPosition(const cEntity & a_Entity)
 {
 	ASSERT(m_State == 3);  // In game mode?
 
-	const auto Delta = (a_Entity.GetPosition() - a_Entity.GetLastSentPosition()) * 32 * 128;
+	const auto Delta = (a_Entity.GetPosition() * 32 * 128).Floor() - (a_Entity.GetLastSentPosition() * 32 * 128).Floor();
 
-	// Limitations of a short
-	static const auto Max = std::numeric_limits<Int16>::max();
-
-	if ((std::abs(Delta.x) <= Max) && (std::abs(Delta.y) <= Max) && (std::abs(Delta.z) <= Max))
+	// Ensure that the delta has enough precision and is within range of a BEInt16:
+	if (
+		Delta.HasNonZeroLength() &&
+		cByteBuffer::CanBEInt16Represent(Delta.x) &&
+		cByteBuffer::CanBEInt16Represent(Delta.y) &&
+		cByteBuffer::CanBEInt16Represent(Delta.z)
+	)
 	{
 		const auto Move = static_cast<Vector3<Int16>>(Delta);
 
@@ -341,7 +344,8 @@ void cProtocol_1_9_0::SendEntityPosition(const cEntity & a_Entity)
 		return;
 	}
 
-	// Too big a movement, do a teleport
+	// Too big or small a movement, do a teleport.
+
 	cPacketizer Pkt(*this, pktTeleportEntity);
 	Pkt.WriteVarInt32(a_Entity.GetUniqueID());
 	Pkt.WriteBEDouble(a_Entity.GetPosX());