From 5c2cc20313e14757e14399051dd814846b543b7f Mon Sep 17 00:00:00 2001
From: ZappoMan <bradh@konamoxt.com>
Date: Fri, 28 Nov 2014 17:36:55 -0800
Subject: [PATCH] fixes the stutter in animation when observer moves

---
 interface/src/renderer/AnimationHandle.cpp | 8 +++-----
 libraries/animation/src/AnimationLoop.cpp  | 5 +++--
 libraries/animation/src/AnimationLoop.h    | 4 ++++
 libraries/entities/src/ModelEntityItem.cpp | 4 +++-
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/interface/src/renderer/AnimationHandle.cpp b/interface/src/renderer/AnimationHandle.cpp
index 767f941049..89c265875b 100644
--- a/interface/src/renderer/AnimationHandle.cpp
+++ b/interface/src/renderer/AnimationHandle.cpp
@@ -138,11 +138,9 @@ void AnimationHandle::simulate(float deltaTime) {
         return;
     }
     
-    // TODO: When moving the loop/frame calculations to AnimationLoop class, we changed this behavior
-    // see AnimationLoop class for more details. Do we need to support clamping the endFrameIndex to
-    // the max number of frames in the geometry???
-    //
-    // float endFrameIndex = qMin(_lastFrame, animationGeometry.animationFrames.size() - (_loop ? 0.0f : 1.0f));
+    if (_animationLoop.getMaxFrameIndexHint() != animationGeometry.animationFrames.size()) {
+        _animationLoop.setMaxFrameIndexHint(animationGeometry.animationFrames.size());
+    }
         
     // blend between the closest two frames
     applyFrame(getFrameIndex());
diff --git a/libraries/animation/src/AnimationLoop.cpp b/libraries/animation/src/AnimationLoop.cpp
index f81904990f..75a3cdd338 100644
--- a/libraries/animation/src/AnimationLoop.cpp
+++ b/libraries/animation/src/AnimationLoop.cpp
@@ -20,7 +20,8 @@ AnimationLoop::AnimationLoop() :
     _firstFrame(0.0f),
     _lastFrame(FLT_MAX),
     _running(false),
-    _frameIndex(0.0f)
+    _frameIndex(0.0f),
+    _maxFrameIndexHint(FLT_MAX)
 {
 }
 
@@ -55,7 +56,7 @@ void AnimationLoop::simulate(float deltaTime) {
     
     // If we knew the number of frames from the animation, we'd consider using it here 
     // animationGeometry.animationFrames.size()
-    float maxFrame = _lastFrame; 
+    float maxFrame = _maxFrameIndexHint; 
     float endFrameIndex = qMin(_lastFrame, maxFrame - (_loop ? 0.0f : 1.0f));
     float startFrameIndex = qMin(_firstFrame, endFrameIndex);
     if ((!_loop && (_frameIndex < startFrameIndex || _frameIndex > endFrameIndex)) || startFrameIndex == endFrameIndex) {
diff --git a/libraries/animation/src/AnimationLoop.h b/libraries/animation/src/AnimationLoop.h
index b56f68f23b..aff2cd86ee 100644
--- a/libraries/animation/src/AnimationLoop.h
+++ b/libraries/animation/src/AnimationLoop.h
@@ -44,6 +44,9 @@ public:
 
     void setFrameIndex(float frameIndex) { _frameIndex = glm::clamp(frameIndex, _firstFrame, _lastFrame); }
     float getFrameIndex() const { return _frameIndex; }
+
+    void setMaxFrameIndexHint(float value) { _maxFrameIndexHint = value; }
+    float getMaxFrameIndexHint() const { return _maxFrameIndexHint; }
     
     void start() { setRunning(true); }
     void stop() { setRunning(false); }
@@ -58,6 +61,7 @@ private:
     float _lastFrame;
     bool _running;
     float _frameIndex;
+    float _maxFrameIndexHint;
 };
 
 #endif // hifi_AnimationLoop_h
diff --git a/libraries/entities/src/ModelEntityItem.cpp b/libraries/entities/src/ModelEntityItem.cpp
index 31a0c57f5b..63fe3daa03 100644
--- a/libraries/entities/src/ModelEntityItem.cpp
+++ b/libraries/entities/src/ModelEntityItem.cpp
@@ -344,7 +344,9 @@ QVector<glm::quat> ModelEntityItem::getAnimationFrame() {
         Animation* myAnimation = getAnimation(_animationURL);
         QVector<FBXAnimationFrame> frames = myAnimation->getFrames();
         int frameCount = frames.size();
-
+        if (_animationLoop.getMaxFrameIndexHint() != frameCount) {
+            _animationLoop.setMaxFrameIndexHint(frameCount);
+        }
         if (frameCount > 0) {
             int animationFrameIndex = (int)(glm::floor(getAnimationFrameIndex())) % frameCount;
             if (animationFrameIndex < 0 || animationFrameIndex > frameCount) {