From 86d6fd45de95962b23d2c30c33da242666e838fb Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Thu, 29 May 2014 08:19:43 -0700
Subject: [PATCH] safe copy of JointState data

---
 interface/src/renderer/Model.cpp | 26 +++++++++++++++++++-------
 interface/src/renderer/Model.h   |  6 ++++--
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/interface/src/renderer/Model.cpp b/interface/src/renderer/Model.cpp
index 215678dedc..1a857ff811 100644
--- a/interface/src/renderer/Model.cpp
+++ b/interface/src/renderer/Model.cpp
@@ -138,8 +138,9 @@ void Model::initSkinProgram(ProgramObject& program, Model::SkinLocations& locati
 QVector<JointState> Model::createJointStates(const FBXGeometry& geometry) {
     QVector<JointState> jointStates;
     foreach (const FBXJoint& joint, geometry.joints) {
+        // NOTE: the state keeps a pointer to an FBXJoint
         JointState state;
-        state.setFBXJoint(joint);
+        state.setFBXJoint(&joint);
         jointStates.append(state);
     }
 
@@ -408,7 +409,7 @@ bool Model::updateGeometry() {
                 int oldIndex = it.value() - 1;
                 int newIndex = newGeometry.getJointIndex(it.key());
                 if (newIndex != -1) {
-                    newJointStates[newIndex] = _jointStates.at(oldIndex);
+                    newJointStates[newIndex].copyState(_jointStates[oldIndex]);
                 }
             }
         } 
@@ -1890,15 +1891,26 @@ JointState::JointState() :
     _fbxJoint(NULL) {
 }
 
-void JointState::setFBXJoint(const FBXJoint& joint) { 
-    assert(&joint != NULL);
-    _translation = joint.translation;
-    _rotation = joint.rotation;
-    _fbxJoint = &joint;
+void JointState::setFBXJoint(const FBXJoint* joint) { 
+    assert(joint != NULL);
+    _translation = joint->translation;
+    _rotation = joint->rotation;
+    // NOTE: JointState does not own the FBXJoint to which it points.
+    _fbxJoint = joint;
 }
 
 void JointState::updateWorldTransform(const glm::mat4& baseTransform, const glm::quat& parentRotation) {
+    assert(_fbxJoint != NULL);
     glm::quat combinedRotation = _fbxJoint->preRotation * _rotation * _fbxJoint->postRotation;    
     _transform = baseTransform * glm::translate(_translation) * _fbxJoint->preTransform * glm::mat4_cast(combinedRotation) * _fbxJoint->postTransform;
     _combinedRotation = parentRotation * combinedRotation;
 }
+
+void JointState::copyState(const JointState& state) {
+    _translation = state._translation;
+    _rotation = state._rotation;
+    _transform = state._transform;
+    _combinedRotation = state._combinedRotation;
+    _animationPriority = state._animationPriority;
+    // DO NOT copy _fbxJoint
+}
diff --git a/interface/src/renderer/Model.h b/interface/src/renderer/Model.h
index 349e8305c4..b8a5de5902 100644
--- a/interface/src/renderer/Model.h
+++ b/interface/src/renderer/Model.h
@@ -35,11 +35,13 @@ class JointState {
 public:
     JointState();
 
-    void setFBXJoint(const FBXJoint& joint); 
+    void setFBXJoint(const FBXJoint* joint); 
     const FBXJoint& getFBXJoint() const { return *_fbxJoint; }
 
     void updateWorldTransform(const glm::mat4& baseTransform, const glm::quat& parentRotation);
 
+    void copyState(const JointState& state);
+
     glm::vec3 _translation;  // translation relative to parent
     glm::quat _rotation;     // rotation relative to parent
     glm::mat4 _transform;    // rotation to world frame + translation in model frame
@@ -47,7 +49,7 @@ public:
     float _animationPriority; // the priority of the animation affecting this joint
 
 private:
-    const FBXJoint* _fbxJoint;    // JointState does not own its FBXJoint
+    const FBXJoint* _fbxJoint; // JointState does NOT own its FBXJoint
 };
 
 /// A generic 3D model displaying geometry loaded from a URL.