From 28d4d29bb60bd4247f829fdf3aef5d3820485ec6 Mon Sep 17 00:00:00 2001
From: Seth Alves <seth@highfidelity.io>
Date: Thu, 5 Nov 2015 15:07:00 -0800
Subject: [PATCH 1/2] smooth hold action velocity over 2 frames

---
 interface/src/avatar/AvatarActionHold.cpp | 6 +++++-
 interface/src/avatar/AvatarActionHold.h   | 3 +++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/interface/src/avatar/AvatarActionHold.cpp b/interface/src/avatar/AvatarActionHold.cpp
index 70216eca11..6078d326e0 100644
--- a/interface/src/avatar/AvatarActionHold.cpp
+++ b/interface/src/avatar/AvatarActionHold.cpp
@@ -107,8 +107,12 @@ void AvatarActionHold::doKinematicUpdate(float deltaTimeStep) {
     withWriteLock([&]{
         if (_kinematicSetVelocity) {
             if (_previousSet) {
-                glm::vec3 positionalVelocity = (_positionalTarget - _previousPositionalTarget) / deltaTimeStep;
+                // smooth velocity over 2 frames
+                glm::vec3 positionalDelta = _positionalTarget - _previousPositionalTarget;
+                glm::vec3 positionalVelocity = (positionalDelta + previousPositionalDelta) / (deltaTimeStep + previousDeltaTimeStep);
                 rigidBody->setLinearVelocity(glmToBullet(positionalVelocity));
+                previousPositionalDelta = positionalDelta;
+                previousDeltaTimeStep = deltaTimeStep;
             }
         }
 
diff --git a/interface/src/avatar/AvatarActionHold.h b/interface/src/avatar/AvatarActionHold.h
index 6badf97e9e..4856a17b89 100644
--- a/interface/src/avatar/AvatarActionHold.h
+++ b/interface/src/avatar/AvatarActionHold.h
@@ -46,6 +46,9 @@ private:
     bool _previousSet { false };
     glm::vec3 _previousPositionalTarget;
     glm::quat _previousRotationalTarget;
+
+    float previousDeltaTimeStep = 0.0f;
+    glm::vec3 previousPositionalDelta;
 };
 
 #endif // hifi_AvatarActionHold_h

From 46b7b92b2f76aded24a7134b9afa455197b12c5a Mon Sep 17 00:00:00 2001
From: Seth Alves <seth.alves@gmail.com>
Date: Fri, 6 Nov 2015 11:54:51 -0800
Subject: [PATCH 2/2] prefix private member variables with _

---
 interface/src/avatar/AvatarActionHold.cpp | 6 +++---
 interface/src/avatar/AvatarActionHold.h   | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/interface/src/avatar/AvatarActionHold.cpp b/interface/src/avatar/AvatarActionHold.cpp
index 6078d326e0..866f444b32 100644
--- a/interface/src/avatar/AvatarActionHold.cpp
+++ b/interface/src/avatar/AvatarActionHold.cpp
@@ -109,10 +109,10 @@ void AvatarActionHold::doKinematicUpdate(float deltaTimeStep) {
             if (_previousSet) {
                 // smooth velocity over 2 frames
                 glm::vec3 positionalDelta = _positionalTarget - _previousPositionalTarget;
-                glm::vec3 positionalVelocity = (positionalDelta + previousPositionalDelta) / (deltaTimeStep + previousDeltaTimeStep);
+                glm::vec3 positionalVelocity = (positionalDelta + _previousPositionalDelta) / (deltaTimeStep + _previousDeltaTimeStep);
                 rigidBody->setLinearVelocity(glmToBullet(positionalVelocity));
-                previousPositionalDelta = positionalDelta;
-                previousDeltaTimeStep = deltaTimeStep;
+                _previousPositionalDelta = positionalDelta;
+                _previousDeltaTimeStep = deltaTimeStep;
             }
         }
 
diff --git a/interface/src/avatar/AvatarActionHold.h b/interface/src/avatar/AvatarActionHold.h
index 4856a17b89..eb8ebf2525 100644
--- a/interface/src/avatar/AvatarActionHold.h
+++ b/interface/src/avatar/AvatarActionHold.h
@@ -47,8 +47,8 @@ private:
     glm::vec3 _previousPositionalTarget;
     glm::quat _previousRotationalTarget;
 
-    float previousDeltaTimeStep = 0.0f;
-    glm::vec3 previousPositionalDelta;
+    float _previousDeltaTimeStep = 0.0f;
+    glm::vec3 _previousPositionalDelta;
 };
 
 #endif // hifi_AvatarActionHold_h