adjust terse avatar update filtering to send updates when distance traveled does not match expected distance, rather than at a fixed time period. this should smooth avatar motion somewhat when moving in a straight line and velocity is constant.

1 files changed, 17 insertions, 3 deletions

diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 5b86735..feab35c 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -2395,6 +2395,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         // vars to support reduced update frequency when velocity is unchanged
         private Vector3 lastVelocitySentToAllClients = Vector3.Zero;
+        private Vector3 lastPositionSentToAllClients = Vector3.Zero;
         private int lastTerseUpdateToAllClientsTick = Util.EnvironmentTickCount();
 
         /// <summary>
@@ -2404,14 +2405,27 @@ namespace OpenSim.Region.Framework.Scenes
         {
             int currentTick = Util.EnvironmentTickCount();
 
-            // decrease update frequency when avatar is moving but velocity is not changing
+            // Decrease update frequency when avatar is moving but velocity is
+            // not changing.
+            // If there is a mismatch between distance travelled and expected
+            // distance based on last velocity sent and velocity hasnt changed,
+            // then send a new terse update
+
+            float timeSinceLastUpdate = (currentTick - lastTerseUpdateToAllClientsTick) * 0.001f;
+
+            Vector3 expectedPosition = lastPositionSentToAllClients + lastVelocitySentToAllClients * timeSinceLastUpdate;
+
+            float absoluteDistanceError = (float)Math.Abs(Vector3.Distance(m_pos, expectedPosition));
+
+
             if (m_velocity.Length() < 0.01f
-                || Vector3.Distance(lastVelocitySentToAllClients, m_velocity) > 0.01f
-                || currentTick - lastTerseUpdateToAllClientsTick > 1500)
+                || absoluteDistanceError > 0.25f // arbitrary distance error threshold
+                || Vector3.Distance(lastVelocitySentToAllClients, m_velocity) > 0.01f)
             {
                 m_perfMonMS = currentTick;
                 lastVelocitySentToAllClients = m_velocity;
                 lastTerseUpdateToAllClientsTick = currentTick;
+                lastPositionSentToAllClients = m_pos;
 
                 m_scene.ForEachClient(SendTerseUpdateToClient);