From c530c530ef05862af210e3085465936c0522b4ea Mon Sep 17 00:00:00 2001
From: David Rowe <david@ctrlaltstudio.com>
Date: Wed, 20 May 2015 17:26:31 -0700
Subject: [PATCH] Make eyelids follow iris as head tilts - for DDE and no face
 tracking

---
 interface/src/avatar/Head.cpp | 58 ++++++++++++++++++++++++++---------
 interface/src/avatar/Head.h   |  1 +
 2 files changed, 45 insertions(+), 14 deletions(-)

diff --git a/interface/src/avatar/Head.cpp b/interface/src/avatar/Head.cpp
index e0cdef109e..8691243c07 100644
--- a/interface/src/avatar/Head.cpp
+++ b/interface/src/avatar/Head.cpp
@@ -93,22 +93,24 @@ void Head::simulate(float deltaTime, bool isMine, bool billboard) {
             if (_isFaceTrackerConnected) {
                 _blendshapeCoefficients = faceTracker->getBlendshapeCoefficients();
 
-                if (typeid(*faceTracker) == typeid(DdeFaceTracker) 
-                    && Menu::getInstance()->isOptionChecked(MenuOption::UseAudioForMouth)) {
+                if (typeid(*faceTracker) == typeid(DdeFaceTracker)) {
 
-                    calculateMouthShapes();
+                    if (Menu::getInstance()->isOptionChecked(MenuOption::UseAudioForMouth)) {
+                        calculateMouthShapes();
 
-                    const int JAW_OPEN_BLENDSHAPE = 21;
-                    const int MMMM_BLENDSHAPE = 34;
-                    const int FUNNEL_BLENDSHAPE = 40;
-                    const int SMILE_LEFT_BLENDSHAPE = 28;
-                    const int SMILE_RIGHT_BLENDSHAPE = 29;
-                    _blendshapeCoefficients[JAW_OPEN_BLENDSHAPE] += _audioJawOpen;
-                    _blendshapeCoefficients[SMILE_LEFT_BLENDSHAPE] += _mouth4;
-                    _blendshapeCoefficients[SMILE_RIGHT_BLENDSHAPE] += _mouth4;
-                    _blendshapeCoefficients[MMMM_BLENDSHAPE] += _mouth2;
-                    _blendshapeCoefficients[FUNNEL_BLENDSHAPE] += _mouth3;
+                        const int JAW_OPEN_BLENDSHAPE = 21;
+                        const int MMMM_BLENDSHAPE = 34;
+                        const int FUNNEL_BLENDSHAPE = 40;
+                        const int SMILE_LEFT_BLENDSHAPE = 28;
+                        const int SMILE_RIGHT_BLENDSHAPE = 29;
+                        _blendshapeCoefficients[JAW_OPEN_BLENDSHAPE] += _audioJawOpen;
+                        _blendshapeCoefficients[SMILE_LEFT_BLENDSHAPE] += _mouth4;
+                        _blendshapeCoefficients[SMILE_RIGHT_BLENDSHAPE] += _mouth4;
+                        _blendshapeCoefficients[MMMM_BLENDSHAPE] += _mouth2;
+                        _blendshapeCoefficients[FUNNEL_BLENDSHAPE] += _mouth3;
+                    }
 
+                    applyEyelidOffset(getFinalOrientationInWorldFrame());
                 }
             }
         }
@@ -203,6 +205,9 @@ void Head::simulate(float deltaTime, bool isMine, bool billboard) {
                                                                     _mouth3,
                                                                     _mouth4,
                                                                     _blendshapeCoefficients);
+
+        applyEyelidOffset(getOrientation());
+
     } else {
         _saccade = glm::vec3();
     }
@@ -218,7 +223,6 @@ void Head::simulate(float deltaTime, bool isMine, bool billboard) {
         }
     }
     _eyePosition = calculateAverageEyePosition();
-
 }
 
 void Head::calculateMouthShapes() {
@@ -249,6 +253,32 @@ void Head::calculateMouthShapes() {
     _mouth4 = glm::mix(_audioJawOpen, _mouth4, SMILE_PERIOD + randFloat() * SMILE_RANDOM_PERIOD);
 }
 
+void Head::applyEyelidOffset(glm::quat headOrientation) {
+    // Adjusts the eyelid blendshape coefficients so that the eyelid follows the iris as the head pitches.
+
+    glm::quat eyeRotation = rotationBetween(headOrientation * IDENTITY_FRONT, getCorrectedLookAtPosition() - _eyePosition);
+    eyeRotation = eyeRotation * glm::angleAxis(safeEulerAngles(headOrientation).y, IDENTITY_UP);  // Rotation w.r.t. head
+    float eyePitch = safeEulerAngles(eyeRotation).x;
+
+    const float EYE_PITCH_TO_COEFFICIENT = 1.6f;  // Empirically determined
+    const float MAX_EYELID_OFFSET = 0.8f;  // So that don't fully close eyes when looking way down
+    float eyelidOffset = glm::clamp(-eyePitch * EYE_PITCH_TO_COEFFICIENT, -1.0f, MAX_EYELID_OFFSET);
+
+    for (int i = 0; i < 2; i++) {
+        const int LEFT_EYE = 8;
+        float eyeCoefficient = _blendshapeCoefficients[i] - _blendshapeCoefficients[LEFT_EYE + i];  // Raw value
+        eyeCoefficient = glm::clamp(eyelidOffset + eyeCoefficient * (1.0f - eyelidOffset), -1.0f, 1.0f);
+        if (eyeCoefficient > 0.0f) {
+            _blendshapeCoefficients[i] = eyeCoefficient;
+            _blendshapeCoefficients[LEFT_EYE + i] = 0.0f;
+
+        } else {
+            _blendshapeCoefficients[i] = 0.0f;
+            _blendshapeCoefficients[LEFT_EYE + i] = -eyeCoefficient;
+        }
+    }
+}
+
 void Head::relaxLean(float deltaTime) {
     // restore rotation, lean to neutral positions
     const float LEAN_RELAXATION_PERIOD = 0.25f;   // seconds
diff --git a/interface/src/avatar/Head.h b/interface/src/avatar/Head.h
index e523d958a6..6eba16824e 100644
--- a/interface/src/avatar/Head.h
+++ b/interface/src/avatar/Head.h
@@ -155,6 +155,7 @@ private:
     // private methods
     void renderLookatVectors(glm::vec3 leftEyePosition, glm::vec3 rightEyePosition, glm::vec3 lookatPosition);
     void calculateMouthShapes();
+    void applyEyelidOffset(glm::quat headOrientation);
 
     friend class FaceModel;
 };