From 72c74984540a6f6bc593be7136871e9d6de06d28 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Wed, 23 Jul 2014 16:56:40 -0700
Subject: [PATCH] add JointState::getDistanceToParent()

---
 interface/src/renderer/JointState.cpp | 4 ++++
 interface/src/renderer/JointState.h   | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/interface/src/renderer/JointState.cpp b/interface/src/renderer/JointState.cpp
index 865036df8e..26fa29c4a9 100644
--- a/interface/src/renderer/JointState.cpp
+++ b/interface/src/renderer/JointState.cpp
@@ -20,6 +20,7 @@
 JointState::JointState() :
     _animationPriority(0.0f),
     _positionInParentFrame(0.0f),
+    _distanceToParent(0.0f),
     _fbxJoint(NULL),
     _constraint(NULL) {
 }
@@ -29,6 +30,7 @@ JointState::JointState(const JointState& other) : _constraint(NULL) {
     _rotation = other._rotation;
     _rotationInConstrainedFrame = other._rotationInConstrainedFrame;
     _positionInParentFrame = other._positionInParentFrame;
+    _distanceToParent = other._distanceToParent;
     _animationPriority = other._animationPriority;
     _fbxJoint = other._fbxJoint;
     // DO NOT copy _constraint
@@ -72,6 +74,7 @@ void JointState::copyState(const JointState& state) {
     _rotation = extractRotation(_transform);
     _rotationInConstrainedFrame = state._rotationInConstrainedFrame;
     _positionInParentFrame = state._positionInParentFrame;
+    _distanceToParent = state._distanceToParent;
 
     _visibleTransform = state._visibleTransform;
     _visibleRotation = extractRotation(_visibleTransform);
@@ -82,6 +85,7 @@ void JointState::copyState(const JointState& state) {
 void JointState::initTransform(const glm::mat4& parentTransform) {
     computeTransform(parentTransform);
     _positionInParentFrame = glm::inverse(extractRotation(parentTransform)) * (extractTranslation(_transform) - extractTranslation(parentTransform));
+    _distanceToParent = glm::length(_positionInParentFrame);
 }
 
 void JointState::computeTransform(const glm::mat4& parentTransform) {
diff --git a/interface/src/renderer/JointState.h b/interface/src/renderer/JointState.h
index 86ee5d01b7..a3b792abc4 100644
--- a/interface/src/renderer/JointState.h
+++ b/interface/src/renderer/JointState.h
@@ -51,6 +51,7 @@ public:
     glm::quat getRotationInParentFrame() const;
     glm::quat getVisibleRotationInParentFrame() const;
     const glm::vec3& getPositionInParentFrame() const { return _positionInParentFrame; }
+    float getDistanceToParent() const { return _distanceToParent; }
 
     int getParentIndex() const { return _fbxJoint->parentIndex; }
 
@@ -104,6 +105,7 @@ private:
     glm::quat _rotation;  // joint- to model-frame
     glm::quat _rotationInConstrainedFrame; // rotation in frame where angular constraints would be applied
     glm::vec3 _positionInParentFrame; // only changes when the Model is scaled
+    float _distanceToParent;
 
     glm::mat4 _visibleTransform;
     glm::quat _visibleRotation;