Merged development

Signed-off-by: AMZN-Olex <5432499+AMZN-Olex@users.noreply.github.com>

Gems/Multiplayer/Code/Include/Multiplayer/Components/NetworkTransformComponent.h

@@ -36,6 +36,8 @@ namespace Multiplayer
         void OnScaleChangedEvent(float scale);
         void OnResetCountChangedEvent();
 
+        void UpdateTargetHostFrameId();
+
         AZ::Transform m_previousTransform = AZ::Transform::CreateIdentity();
         AZ::Transform m_targetTransform = AZ::Transform::CreateIdentity();
 
@@ -45,6 +47,8 @@ namespace Multiplayer
         AZ::Event<uint8_t>::Handler m_resetCountEventHandler;
 
         EntityPreRenderEvent::Handler m_entityPreRenderEventHandler;
+
+        Multiplayer::HostFrameId m_targetHostFrameId = HostFrameId(0);
     };
 
     class NetworkTransformComponentController

Gems/Multiplayer/Code/Include/Multiplayer/IMultiplayer.h

@@ -122,6 +122,11 @@ namespace Multiplayer
         //! @return the current server time in milliseconds
         virtual AZ::TimeMs GetCurrentHostTimeMs() const = 0;
 
+        //! Returns the current blend factor for client side interpolation
+        //! This value is only relevant on the client and is used to smooth between host frames
+        //! @return the current blend factor
+        virtual float GetCurrentBlendFactor() const = 0;
+
         //! Returns the network time instance bound to this multiplayer instance.
         //! @return pointer to the network time instance bound to this multiplayer instance
         virtual INetworkTime* GetNetworkTime() = 0;
@@ -182,23 +187,27 @@ namespace Multiplayer
     class ScopedAlterTime final
     {
     public:
-        inline ScopedAlterTime(HostFrameId frameId, AZ::TimeMs timeMs, AzNetworking::ConnectionId connectionId)
+        inline ScopedAlterTime(HostFrameId frameId, AZ::TimeMs timeMs, float blendFactor, AzNetworking::ConnectionId connectionId)
         {
             INetworkTime* time = GetNetworkTime();
             m_previousHostFrameId = time->GetHostFrameId();
             m_previousHostTimeMs = time->GetHostTimeMs();
             m_previousRewindConnectionId = time->GetRewindingConnectionId();
             time->AlterTime(frameId, timeMs, connectionId);
+            m_previousBlendFactor = time->GetHostBlendFactor();
+            time->AlterBlendFactor(blendFactor);
         }
         inline ~ScopedAlterTime()
         {
             INetworkTime* time = GetNetworkTime();
             time->AlterTime(m_previousHostFrameId, m_previousHostTimeMs, m_previousRewindConnectionId);
+            time->AlterBlendFactor(m_previousBlendFactor);
         }
     private:
         HostFrameId m_previousHostFrameId = InvalidHostFrameId;
         AZ::TimeMs m_previousHostTimeMs = AZ::TimeMs{ 0 };
         AzNetworking::ConnectionId m_previousRewindConnectionId = AzNetworking::InvalidConnectionId;
+        float m_previousBlendFactor = DefaultBlendFactor;
     };
 
     inline const char* GetEnumString(MultiplayerAgentType value)

Gems/Multiplayer/Code/Include/Multiplayer/MultiplayerTypes.h

@@ -22,6 +22,9 @@ namespace Multiplayer
     //! The default number of rewindable samples for us to store.
     static constexpr uint32_t RewindHistorySize = 128;
 
+    //! The default blend factor for ScopedAlterTime
+    static constexpr float DefaultBlendFactor = 1.f;
+
     AZ_TYPE_SAFE_INTEGRAL(HostId, uint32_t);
     static constexpr HostId InvalidHostId = static_cast<HostId>(-1);
 

Gems/Multiplayer/Code/Include/Multiplayer/NetworkInput/NetworkInput.h

@@ -45,6 +45,9 @@ namespace Multiplayer
         AZ::TimeMs GetHostTimeMs() const;
         AZ::TimeMs& ModifyHostTimeMs();
 
+        void SetHostBlendFactor(float hostBlendFactor);
+        float GetHostBlendFactor() const;
+
         void AttachNetBindComponent(NetBindComponent* netBindComponent);
 
         bool Serialize(AzNetworking::ISerializer& serializer);
@@ -73,6 +76,7 @@ namespace Multiplayer
         ClientInputId m_inputId = ClientInputId{ 0 };
         HostFrameId m_hostFrameId = InvalidHostFrameId;
         AZ::TimeMs m_hostTimeMs = AZ::TimeMs{ 0 };
+        float m_hostBlendFactor = 0.f;
         ConstNetworkEntityHandle m_owner;
         bool m_wasAttached = false;
     };

Gems/Multiplayer/Code/Include/Multiplayer/NetworkTime/INetworkTime.h

@@ -43,6 +43,10 @@ namespace Multiplayer
         //! @return the hosts current timeMs
         virtual AZ::TimeMs GetHostTimeMs() const = 0;
 
+        //! Retrieves the hosts current blend factor (may be rewound on the server during backward reconciliation).
+        //! @return the hosts current blend factor
+        virtual float GetHostBlendFactor() const = 0;
+
         //! Get the controlling connection that may be currently altering global game time.
         //! Note this abstraction is required at a relatively high level to allow for 'don't rewind the shooter' semantics
         //! @return the ConnectionId of the connection requesting the rewind operation
@@ -60,6 +64,10 @@ namespace Multiplayer
         //! @param rewindConnectionId the rewinding ConnectionId 
         virtual void AlterTime(HostFrameId frameId, AZ::TimeMs timeMs, AzNetworking::ConnectionId rewindConnectionId) = 0;
 
+        //! Alters the current Host blend factor. Used to drive interpolation in rewound states.
+        //! @param blendFactor the blend factor to use
+        virtual void AlterBlendFactor(float blendFactor) = 0;
+
         //! Syncs all entities contained within a volume to the current rewind state.
         //! @param rewindVolume the volume to rewind entities within (needed for physics entities)
         virtual void SyncEntitiesToRewindState(const AZ::Aabb& rewindVolume) = 0;

Gems/Multiplayer/Code/Include/Multiplayer/NetworkTime/RewindableObject.h

@@ -60,6 +60,10 @@ namespace Multiplayer
         //! @return value in const base type form
         const BASE_TYPE& Get() const;
 
+        //! Const base type retriever for one host frame behind Get(). Only intended for use in SyncRewind contexts.
+        //! @return value in const base type form
+        const BASE_TYPE& GetPrevious() const;
+
         //! Base type retriever.
         //! @return value in base type form
         BASE_TYPE& Modify();

Gems/Multiplayer/Code/Include/Multiplayer/NetworkTime/RewindableObject.inl

@@ -66,6 +66,12 @@ namespace Multiplayer
         return GetValueForTime(GetCurrentTimeForProperty());
     }
 
+    template <typename BASE_TYPE, AZStd::size_t REWIND_SIZE>
+    inline const BASE_TYPE& RewindableObject<BASE_TYPE, REWIND_SIZE>::GetPrevious() const
+    {
+        return GetValueForTime(GetCurrentTimeForProperty() - HostFrameId(1));
+    }
+
     template <typename BASE_TYPE, AZStd::size_t REWIND_SIZE>
     inline BASE_TYPE& RewindableObject<BASE_TYPE, REWIND_SIZE>::Modify()
     {