From 0386dec2a67e0f8d450d7f49c8643bb82c9427ba Mon Sep 17 00:00:00 2001
From: Andrzej Kapolka <drzej.k@gmail.com>
Date: Wed, 23 Apr 2014 12:09:54 -0700
Subject: [PATCH] Provide option to align wrists with forearms.

---
 interface/src/Menu.cpp                 |  1 +
 interface/src/Menu.h                   |  1 +
 interface/src/avatar/SkeletonModel.cpp | 20 ++++++++++++++++++--
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/interface/src/Menu.cpp b/interface/src/Menu.cpp
index 0a0bd599eb..a7012d838d 100644
--- a/interface/src/Menu.cpp
+++ b/interface/src/Menu.cpp
@@ -336,6 +336,7 @@ Menu::Menu() :
     addCheckableActionToQMenuAndActionHash(handOptionsMenu, MenuOption::PlaySlaps, 0, false);
     addCheckableActionToQMenuAndActionHash(handOptionsMenu, MenuOption::HandsCollideWithSelf, 0, false);
     addCheckableActionToQMenuAndActionHash(handOptionsMenu, MenuOption::ShowIKConstraints, 0, false);
+    addCheckableActionToQMenuAndActionHash(handOptionsMenu, MenuOption::AlignForearmsWithWrists, 0, true);
 
     addDisabledActionAndSeparator(developerMenu, "Testing");
 
diff --git a/interface/src/Menu.h b/interface/src/Menu.h
index f9f97be379..09b5fabfc8 100644
--- a/interface/src/Menu.h
+++ b/interface/src/Menu.h
@@ -256,6 +256,7 @@ private:
 
 namespace MenuOption {
     const QString AboutApp = "About Interface";
+    const QString AlignForearmsWithWrists = "Align Forearms with Wrists";
     const QString AmbientOcclusion = "Ambient Occlusion";
     const QString Atmosphere = "Atmosphere";
     const QString AudioNoiseReduction = "Audio Noise Reduction";
diff --git a/interface/src/avatar/SkeletonModel.cpp b/interface/src/avatar/SkeletonModel.cpp
index f52858b4ff..4bb7814300 100644
--- a/interface/src/avatar/SkeletonModel.cpp
+++ b/interface/src/avatar/SkeletonModel.cpp
@@ -148,10 +148,18 @@ void SkeletonModel::applyPalmData(int jointIndex, const QVector<int>& fingerJoin
     }
     const FBXGeometry& geometry = _geometry->getFBXGeometry();
     float sign = (jointIndex == geometry.rightHandJointIndex) ? 1.0f : -1.0f;
+    int parentJointIndex = geometry.joints.at(jointIndex).parentIndex;
+    if (parentJointIndex == -1) {
+        return;
+    }
     
     // rotate palm to align with palm direction
     glm::quat palmRotation;
-    getJointRotation(jointIndex, palmRotation, true);
+    if (Menu::getInstance()->isOptionChecked(MenuOption::AlignForearmsWithWrists)) {
+        getJointRotation(parentJointIndex, palmRotation, true);
+    } else {
+        getJointRotation(jointIndex, palmRotation, true);
+    }
     palmRotation = rotationBetween(palmRotation * geometry.palmDirection, palm.getNormal()) * palmRotation;
     
     // sort the finger indices by raw x, get the average direction
@@ -177,7 +185,15 @@ void SkeletonModel::applyPalmData(int jointIndex, const QVector<int>& fingerJoin
     }
 
     // set hand position, rotation
-    setJointPosition(jointIndex, palm.getPosition(), palmRotation, true);
+    if (Menu::getInstance()->isOptionChecked(MenuOption::AlignForearmsWithWrists)) {
+        glm::vec3 forearmVector = palmRotation * glm::vec3(sign, 0.0f, 0.0f);
+        setJointPosition(parentJointIndex, palm.getPosition() + forearmVector *
+            geometry.joints.at(jointIndex).distanceToParent * extractUniformScale(_scale), palmRotation, true);
+        _jointStates[jointIndex].rotation = glm::quat();
+        
+    } else {
+        setJointPosition(jointIndex, palm.getPosition(), palmRotation, true);
+    }
 }
 
 void SkeletonModel::updateJointState(int index) {