refactor: expose BufferedLinearInterpolator to public (#1907)

Co-authored-by: Sam Bellomo <[email protected]>

Author: 0xFA11

com.unity.netcode.gameobjects/Components/Interpolator/BufferedLinearInterpolator.cs

@@ -4,13 +4,11 @@
 
 namespace Unity.Netcode
 {
-
     /// <summary>
     /// Solves for incoming values that are jittered
     /// Partially solves for message loss. Unclamped lerping helps hide this, but not completely
     /// </summary>
-    /// <typeparam name="T"></typeparam>
-    internal abstract class BufferedLinearInterpolator<T> where T : struct
+    public abstract class BufferedLinearInterpolator<T> where T : struct
     {
         private struct BufferedItem
         {
@@ -24,6 +22,10 @@ public BufferedItem(T item, double timeSent)
             }
         }
 
+        /// <summary>
+        /// There’s two factors affecting interpolation: buffering (set in NetworkManager’s NetworkTimeSystem) and interpolation time, which is the amount of time it’ll take to reach the target. This is to affect the second one.
+        /// </summary>
+        public float MaximumInterpolationTime = 0.1f;
 
         private const double k_SmallValue = 9.999999439624929E-11; // copied from Vector3's equal operator
 
@@ -69,13 +71,19 @@ public BufferedItem(T item, double timeSent)
 
         private bool InvalidState => m_Buffer.Count == 0 && m_LifetimeConsumedCount == 0;
 
+        /// <summary>
+        /// Resets Interpolator to initial state
+        /// </summary>
         public void Clear()
         {
             m_Buffer.Clear();
             m_EndTimeConsumed = 0.0d;
             m_StartTimeConsumed = 0.0d;
         }
 
+        /// <summary>
+        /// Teleports current interpolation value to targetValue.
+        /// </summary>
         public void ResetTo(T targetValue, double serverTime)
         {
             m_LifetimeConsumedCount = 1;
@@ -89,7 +97,6 @@ public void ResetTo(T targetValue, double serverTime)
             Update(0, serverTime, serverTime);
         }
 
-
         // todo if I have value 1, 2, 3 and I'm treating 1 to 3, I shouldn't interpolate between 1 and 3, I should interpolate from 1 to 2, then from 2 to 3 to get the best path
         private void TryConsumeFromBuffer(double renderTime, double serverTime)
         {
@@ -205,14 +212,16 @@ public T Update(float deltaTime, double renderTime, double serverTime)
                 }
 
                 var target = InterpolateUnclamped(m_InterpStartValue, m_InterpEndValue, t);
-                float maxInterpTime = 0.1f;
-                m_CurrentInterpValue = Interpolate(m_CurrentInterpValue, target, deltaTime / maxInterpTime); // second interpolate to smooth out extrapolation jumps
+                m_CurrentInterpValue = Interpolate(m_CurrentInterpValue, target, deltaTime / MaximumInterpolationTime); // second interpolate to smooth out extrapolation jumps
             }
 
             m_NbItemsReceivedThisFrame = 0;
             return m_CurrentInterpValue;
         }
 
+        /// <summary>
+        /// Add measurements to be used during interpolation. These will be buffered before being made available to be displayed as "latest value".
+        /// </summary>
         public void AddMeasurement(T newMeasurement, double sentTime)
         {
             m_NbItemsReceivedThisFrame++;
@@ -239,17 +248,25 @@ public void AddMeasurement(T newMeasurement, double sentTime)
             }
         }
 
+        /// <summary>
+        /// Gets latest value from the interpolator. This is updated every update as time goes by.
+        /// </summary>
         public T GetInterpolatedValue()
         {
             return m_CurrentInterpValue;
         }
 
+        /// <summary>
+        /// Method to override and adapted to the generic type. This assumes interpolation for that value will be clamped.
+        /// </summary>
         protected abstract T Interpolate(T start, T end, float time);
+        /// <summary>
+        /// Method to override and adapted to the generic type. This assumes interpolation for that value will not be clamped.
+        /// </summary>
         protected abstract T InterpolateUnclamped(T start, T end, float time);
     }
 
-
-    internal class BufferedLinearInterpolatorFloat : BufferedLinearInterpolator<float>
+    public class BufferedLinearInterpolatorFloat : BufferedLinearInterpolator<float>
     {
         protected override float InterpolateUnclamped(float start, float end, float time)
         {
@@ -262,7 +279,7 @@ protected override float Interpolate(float start, float end, float time)
         }
     }
 
-    internal class BufferedLinearInterpolatorQuaternion : BufferedLinearInterpolator<Quaternion>
+    public class BufferedLinearInterpolatorQuaternion : BufferedLinearInterpolator<Quaternion>
     {
         protected override Quaternion InterpolateUnclamped(Quaternion start, Quaternion end, float time)
         {