Adding rewindable mechanisms to support interpolation

Signed-off-by: puvvadar <puvvadar@amazon.com>
2021-07-22 13:49:05 -07:00
parent 69d5f64bb7
commit b55bad496d
10 changed files with 57 additions and 19 deletions
@@ -186,18 +186,20 @@ 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);
+            time->AlterBlendFactor(blendFactor);
        }
        inline ~ScopedAlterTime()
        {
            INetworkTime* time = GetNetworkTime();
            time->AlterTime(m_previousHostFrameId, m_previousHostTimeMs, m_previousRewindConnectionId);
+            time->AlterBlendFactor(DefaultBlendFactor);
        }
    private:
        HostFrameId m_previousHostFrameId = InvalidHostFrameId;
@@ -21,6 +21,9 @@ 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);

@@ -42,6 +42,10 @@ 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
@@ -59,6 +63,10 @@ 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;
@@ -59,6 +59,10 @@ namespace Multiplayer
        //! @return value in const base type form
        const BASE_TYPE& Get() const;

+        //! Const base type retriever for one host frame behind Get().
+        //! @return value in const base type form
+        const BASE_TYPE& GetPrevious() const;
+
        //! Base type retriever.
        //! @return value in base type form
        BASE_TYPE& Modify();
@@ -65,6 +65,12 @@ 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()
    {