Merge branch 'vanilla_0.4.4' and resolve conflicts

TODO: Validate for removed patches due to relocation

Resolved Conflicts:
	LibOVR/Src/Kernel/OVR_ThreadsWinAPI.cpp
	LibOVR/Src/OVR_Linux_HMDDevice.cpp
	LibOVR/Src/OVR_OSX_HMDDevice.cpp
	LibOVR/Src/OVR_Profile.cpp
	LibOVR/Src/OVR_Sensor2Impl.cpp
	LibOVR/Src/OVR_SensorFusion.cpp
	LibOVR/Src/OVR_SensorImpl.cpp
	LibOVR/Src/OVR_Win32_DeviceStatus.cpp
	LibOVR/Src/OVR_Win32_HIDDevice.cpp
	LibOVR/Src/OVR_Win32_HIDDevice.h
	LibOVR/Src/OVR_Win32_HMDDevice.cpp

1 files changed, 0 insertions, 904 deletions

diff --git a/LibOVR/Src/OVR_SensorFusion.cpp b/LibOVR/Src/OVR_SensorFusion.cpp
deleted file mode 100644
index 9918250..0000000
--- a/LibOVR/Src/OVR_SensorFusion.cpp
+++ /dev/null
@@ -1,904 +0,0 @@
-/************************************************************************************
-
-Filename    :   OVR_SensorFusion.cpp
-Content     :   Methods that determine head orientation from sensor data over time
-Created     :   October 9, 2012
-Authors     :   Michael Antonov, Steve LaValle, Dov Katz, Max Katsev, Dan Gierl
-
-Copyright   :   Copyright 2014 Oculus VR, Inc. All Rights reserved.
-
-Licensed under the Oculus VR Rift SDK License Version 3.1 (the "License"); 
-you may not use the Oculus VR Rift SDK except in compliance with the License, 
-which is provided at the time of installation or download, or which 
-otherwise accompanies this software in either electronic or hard copy form.
-
-You may obtain a copy of the License at
-
-http://www.oculusvr.com/licenses/LICENSE-3.1 
-
-Unless required by applicable law or agreed to in writing, the Oculus VR SDK 
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-
-*************************************************************************************/
-
-#include "OVR_SensorFusion.h"
-#include "Kernel/OVR_Log.h"
-#include "Kernel/OVR_System.h"
-#include "OVR_JSON.h"
-#include "OVR_Profile.h"
-#include "OVR_Stereo.h"
-#include "OVR_Recording.h"
-
-// Temporary for debugging
-bool Global_Flag_1 = true;
-
-//Convenient global variables to temporarily extract this data.
-float  TPH_CameraPoseOrientationWxyz[4];
-double TPH_CameraPoseConfidence;
-double TPH_CameraPoseConfidenceThresholdOverrideIfNonZero = 0;
-bool   TPH_IsPositionTracked = false;
-
-
-namespace OVR {
-
-const Transformd DefaultWorldFromCamera(Quatd(), Vector3d(0, 0, -1));
-
-//-------------------------------------------------------------------------------------
-// ***** Sensor Fusion
-
-SensorFusion::SensorFusion(SensorDevice* sensor)
-  : ExposureRecordHistory(100), LastMessageExposureFrame(NULL),
-    FocusDirection(Vector3d(0, 0, 0)), FocusFOV(0.0),
-    FAccelInImuFrame(1000), FAccelInCameraFrame(1000), FAngV(20),
-    EnableGravity(true), EnableYawCorrection(true), MagCalibrated(false),
-    EnableCameraTiltCorrection(true),
-    MotionTrackingEnabled(true), VisionPositionEnabled(true),
-    CenterPupilDepth(0.0)
-{
-   pHandler = new BodyFrameHandler(this);
-
-   // And the clock is running...
-   LogText("*** SensorFusion Startup: TimeSeconds = %f\n", Timer::GetSeconds());
-
-   if (sensor)
-       AttachToSensor(sensor);
-   
-   Reset();
-}
-
-SensorFusion::~SensorFusion()
-{   
-    delete(pHandler);
-}
-
-bool SensorFusion::AttachToSensor(SensorDevice* sensor)
-{
-    pHandler->RemoveHandlerFromDevices();
-    Reset();
-
-    if (sensor != NULL)
-    {
-        // cache mag calibration state
-        MagCalibrated = sensor->IsMagCalibrated();
-        
-        // Load IMU position
-        Array<PositionCalibrationReport> reports;
-        bool result = sensor->GetAllPositionCalibrationReports(&reports);
-        if (result)
-        {
-            PositionCalibrationReport imu = reports[reports.GetSize() - 1];
-            OVR_ASSERT(imu.PositionType == PositionCalibrationReport::PositionType_IMU);
-            // convert from vision to the world frame
-            // TBD convert rotation as necessary?
-            imu.Position.x *= -1.0;
-            imu.Position.z *= -1.0;
-
-            ImuFromScreen = Transformd(Quatd(imu.Normal, imu.Angle), imu.Position).Inverted();
-
-            Recording::GetRecorder().RecordLedPositions(reports);
-            Recording::GetRecorder().RecordDeviceIfcVersion(sensor->GetDeviceInterfaceVersion());
-		}
-        
-        // Repopulate CPFOrigin
-        SetCenterPupilDepth(CenterPupilDepth);
-
-        // Subscribe to sensor updates
-        sensor->AddMessageHandler(pHandler);
-
-        // Initialize the sensor state
-        // TBD: This is a hack to avoid a race condition if sensor status is checked immediately 
-        // after sensor creation but before any data has flowed through.  We should probably
-        // not depend strictly on data flow to determine capabilities like orientation and position
-        // tracking, or else use some sort of synchronous method to wait for data
-        LocklessState init;
-        init.StatusFlags = Status_OrientationTracked;   
-        UpdatedState.SetState(init);
-    }
-
-    return true;
-}
-
-// Resets the current orientation
-void SensorFusion::Reset()
-{
-    Lock::Locker lockScope(pHandler->GetHandlerLock());
-
-    UpdatedState.SetState(LocklessState());
-    WorldFromImu                        = PoseState<double>();
-    WorldFromImu.Pose                   = ImuFromCpf.Inverted(); // place CPF at the origin, not the IMU
-    CameraFromImu                       = PoseState<double>();
-    VisionError                         = PoseState<double>();
-    WorldFromCamera                     = DefaultWorldFromCamera;
-    WorldFromCameraConfidence           = -1;
-
-    ExposureRecordHistory.Clear();
-    NextExposureRecord                  = ExposureRecord();
-    LastMessageExposureFrame            = MessageExposureFrame(NULL);
-    LastVisionAbsoluteTime              = 1e9;
-    Stage                               = 0;
-    
-    MagRefs.Clear();
-    MagRefIdx                           = -1;
-    MagCorrectionIntegralTerm           = Quatd();
-    AccelOffset                         = Vector3d();
-
-    FAccelInCameraFrame.Clear();
-    FAccelInImuFrame.Clear();
-    FAngV.Clear();
-
-    setNeckPivotFromPose ( WorldFromImu.Pose );
-}
-
-//-------------------------------------------------------------------------------------
-//  Vision & message processing
-
-void SensorFusion::OnVisionFailure()
-{
-    // do nothing
-    Recording::GetRecorder().RecordVisionSuccess(false);
-}
-
-void SensorFusion::OnVisionPreviousFrame(const Transform<double>& cameraFromImu)
-{
-    // simply save the observation for use in the next OnVisionSuccess call;
-    // this should not have unintended side-effects for position filtering, 
-    // since the vision time is not updated and the system keeps thinking we don't have vision yet
-    CameraFromImu.Pose = cameraFromImu;
-}
-
-void SensorFusion::OnVisionSuccess(const Transform<double>& cameraFromImu, UInt32 exposureCounter)
-{
-    Lock::Locker lockScope(pHandler->GetHandlerLock());
-
-    Recording::GetRecorder().RecordVisionSuccess(true);
-
-    LastVisionAbsoluteTime = GetTime();
-
-    // ********* LastVisionExposureRecord *********
-
-    // Skip old data and use the record that matches the exposure counter
-    while (!ExposureRecordHistory.IsEmpty() &&
-           (ExposureRecordHistory.PeekFront().ExposureCounter <= exposureCounter))
-    {
-        LastVisionExposureRecord = ExposureRecordHistory.PopFront();
-    }
-
-    // Use current values if we don't have historical data
-    // Right now, this will happen if we get first frame after prediction failure,
-    // and this exposure wasn't in the buffer.  (TBD: Unlikely.. unless IMU message wasn't sent?)
-    if (LastVisionExposureRecord.ExposureCounter != exposureCounter)
-        LastVisionExposureRecord = ExposureRecord(exposureCounter, GetTime(), WorldFromImu, PoseState<double>());
-
-    // ********* CameraFromImu *********
-    
-    // This is stored in the camera frame, so need to be careful when combining with the IMU data,
-    // which is in the world frame
-
-    Transformd cameraFromImuPrev = CameraFromImu.Pose;
-    CameraFromImu.Pose = cameraFromImu; 
-    CameraFromImu.TimeInSeconds = LastVisionExposureRecord.ExposureTime;
-
-    // Check LastVisionExposureRecord.Delta.TimeInSeconds to avoid divide by zero, which we could (rarely)
-    // get if we didn't have exposures delta for history (skipped exposure counters
-    // due to video mode change that stalls USB, etc).
-    if (LastVisionExposureRecord.ImuOnlyDelta.TimeInSeconds > 0.001)
-    {
-        Vector3d visionVelocityInImuFrame = (cameraFromImu.Translation - cameraFromImuPrev.Translation) /
-                                            LastVisionExposureRecord.ImuOnlyDelta.TimeInSeconds;
-        // Use the accel data to estimate the velocity at the exposure time
-        // (as opposed to the average velocity between exposures)
-        Vector3d imuVelocityInWorldFrame = LastVisionExposureRecord.ImuOnlyDelta.LinearVelocity -
-            LastVisionExposureRecord.ImuOnlyDelta.Pose.Translation / LastVisionExposureRecord.ImuOnlyDelta.TimeInSeconds;
-        CameraFromImu.LinearVelocity = visionVelocityInImuFrame + 
-            WorldFromCamera.Inverted().Rotate(imuVelocityInWorldFrame);
-    }
-    else
-    {
-        CameraFromImu.LinearVelocity = Vector3d(0,0,0);
-    }
-}
-
-PoseStated SensorFusion::computeVisionError()
-{
-    PoseStated worldFromImuVision = WorldFromCamera * CameraFromImu;
-    // Here we need to compute the difference between worldFromImuVision and WorldFromImu.
-    // However this difference needs to be represented in the World frame, not IMU frame.
-    // Therefore the computation is different from simply worldFromImuVision.Pose * WorldFromImu.Pose.Inverted().
-    PoseStated err;
-    err.Pose.Rotation = worldFromImuVision.Pose.Rotation * 
-        LastVisionExposureRecord.WorldFromImu.Pose.Rotation.Inverted();
-    err.Pose.Translation = worldFromImuVision.Pose.Translation - 
-        LastVisionExposureRecord.WorldFromImu.Pose.Translation;
-    err.LinearVelocity = worldFromImuVision.LinearVelocity - 
-        LastVisionExposureRecord.WorldFromImu.LinearVelocity;
-    return err;
-}
-
-Transform<double> SensorFusion::GetVisionPrediction(UInt32 exposureCounter)
-{
-    Lock::Locker lockScope(pHandler->GetHandlerLock());
-
-    // Combine the small deltas together
-    // Should only be one iteration, unless we are skipping camera frames
-    ExposureRecord record;
-    PoseState<double> delta = PoseState<double>();
-
-    while (!ExposureRecordHistory.IsEmpty() && 
-           (ExposureRecordHistory.PeekFront().ExposureCounter <= exposureCounter))
-    {
-        record = ExposureRecordHistory.PopFront();
-        delta.AdvanceByDelta(record.ImuOnlyDelta);
-    }
-    // Put the combine exposure record back in the history, for use in HandleVisionSuccess(...)
-    record.ImuOnlyDelta = delta;
-    ExposureRecordHistory.PushFront(record);
-
-    Transformd result;
-    if (record.VisionTrackingAvailable)
-    {
-        // if the tracking is working normally, use the change in the main state (SFusion output)
-        // to compute the prediction
-        result = CameraFromImu.Pose *
-            LastVisionExposureRecord.WorldFromImu.Pose.Inverted() * record.WorldFromImu.Pose;
-    }
-    else
-    {
-        // if we just acquired vision, the main state probably doesn't have the correct position,
-        // so can't rely on it for prediction
-
-        // solution: use the accelerometer and vision velocity to propagate the previous sample forward
-        // (don't forget to transform IMU to the camera frame)
-        result = Transform<double>
-            (
-                CameraFromImu.Pose.Rotation * delta.Pose.Rotation,
-                CameraFromImu.Pose.Translation + CameraFromImu.LinearVelocity * delta.TimeInSeconds +
-                WorldFromCamera.Inverted().Rotate(delta.Pose.Translation)
-            );
-    }
-
-    return result;
-}
-
-void SensorFusion::handleMessage(const MessageBodyFrame& msg)
-{
-    if (msg.Type != Message_BodyFrame || !IsMotionTrackingEnabled())
-        return;
-
-    // Put the sensor readings into convenient local variables
-    Vector3d gyro(msg.RotationRate); 
-    Vector3d accel(msg.Acceleration); 
-    Vector3d mag(msg.MagneticField);
-    double DeltaT = msg.TimeDelta;
-
-    // Keep track of time
-    WorldFromImu.TimeInSeconds = msg.AbsoluteTimeSeconds;
-    // We got an update in the last 60ms and the data is not very old
-    bool visionIsRecent = (GetTime() - LastVisionAbsoluteTime < 0.07) && (GetVisionLatency() < 0.25);
-    Stage++;
-
-    // Insert current sensor data into filter history
-    FAngV.PushBack(gyro);
-    FAccelInImuFrame.Update(accel, DeltaT, Quatd(gyro, gyro.Length() * DeltaT));
-
-    // Process raw inputs
-    // in the future the gravity offset can be calibrated using vision feedback
-    Vector3d accelInWorldFrame = WorldFromImu.Pose.Rotate(accel) - Vector3d(0, 9.8, 0);
-
-    // Recompute the vision error to account for all the corrections and the new data
-    VisionError = computeVisionError();
-
-    // Update headset orientation   
-    WorldFromImu.StoreAndIntegrateGyro(gyro, DeltaT);
-    // Tilt correction based on accelerometer
-    if (EnableGravity)
-        applyTiltCorrection(DeltaT);
-    // Yaw correction based on camera
-    if (EnableYawCorrection && visionIsRecent)
-        applyVisionYawCorrection(DeltaT);
-    // Yaw correction based on magnetometer
-	if (EnableYawCorrection && MagCalibrated) // MagCalibrated is always false for DK2 for now
-		applyMagYawCorrection(mag, DeltaT);
-	// Focus Correction
-	if ((FocusDirection.x != 0.0f || FocusDirection.z != 0.0f) && FocusFOV < Mathf::Pi)
-		applyFocusCorrection(DeltaT);
-
-    // Update camera orientation
-    if (EnableCameraTiltCorrection && visionIsRecent)
-        applyCameraTiltCorrection(accel, DeltaT);
-
-    // The quaternion magnitude may slowly drift due to numerical error,
-    // so it is periodically normalized.
-    if ((Stage & 0xFF) == 0)
-    {
-        WorldFromImu.Pose.Rotation.Normalize();
-        WorldFromCamera.Rotation.Normalize();
-    }
-
-    // Update headset position
-    if (VisionPositionEnabled && visionIsRecent)
-    {
-        // Integrate UMI and velocity here up to a fixed amount of time after vision. 
-        WorldFromImu.StoreAndIntegrateAccelerometer(accelInWorldFrame + AccelOffset, DeltaT);
-        // Position correction based on camera
-        applyPositionCorrection(DeltaT); 
-        // Compute where the neck pivot would be.
-        setNeckPivotFromPose(WorldFromImu.Pose);
-    }
-    else
-    {
-        // Fall back onto internal head model
-        // Use the last-known neck pivot position to figure out the expected IMU position.
-        // (should be the opposite of SensorFusion::setNeckPivotFromPose)
-        WorldFromNeck.Rotation = WorldFromImu.Pose.Rotation;
-        WorldFromImu.Pose = WorldFromNeck * (ImuFromCpf * CpfFromNeck).Inverted();
-
-        // We can't trust velocity past this point.
-        WorldFromImu.LinearVelocity = Vector3d(0,0,0);
-        WorldFromImu.LinearAcceleration = accelInWorldFrame;
-    }
-
-    // Compute the angular acceleration
-    WorldFromImu.AngularAcceleration = (FAngV.GetSize() >= 12 && DeltaT > 0) ? 
-        (FAngV.SavitzkyGolayDerivative12() / DeltaT) : Vector3d();
-
-    // Update the dead reckoning state used for incremental vision tracking
-    NextExposureRecord.ImuOnlyDelta.StoreAndIntegrateGyro(gyro, DeltaT);
-    NextExposureRecord.ImuOnlyDelta.StoreAndIntegrateAccelerometer(accelInWorldFrame, DeltaT);
-    NextExposureRecord.ImuOnlyDelta.TimeInSeconds = WorldFromImu.TimeInSeconds - LastMessageExposureFrame.CameraTimeSeconds;
-    NextExposureRecord.VisionTrackingAvailable &= (VisionPositionEnabled && visionIsRecent);
-
-	Recording::GetRecorder().LogData("sfTimeSeconds", WorldFromImu.TimeInSeconds);
-    Recording::GetRecorder().LogData("sfStage", (double)Stage);
-	Recording::GetRecorder().LogData("sfPose", WorldFromImu.Pose);
-	//Recorder::LogData("sfAngAcc", State.AngularAcceleration);
-	//Recorder::LogData("sfAngVel", State.AngularVelocity);
-	//Recorder::LogData("sfLinAcc", State.LinearAcceleration);
-	//Recorder::LogData("sfLinVel", State.LinearVelocity);
-
-    // Store the lockless state.    
-    LocklessState lstate;
-    lstate.StatusFlags       = Status_OrientationTracked;
-    if (VisionPositionEnabled)
-        lstate.StatusFlags  |= Status_PositionConnected;
-    if (VisionPositionEnabled && visionIsRecent)
-        lstate.StatusFlags  |= Status_PositionTracked;
-
-	//A convenient means to temporarily extract this flag
-	TPH_IsPositionTracked = visionIsRecent;
-
-    lstate.State        = WorldFromImu;
-    lstate.Temperature  = msg.Temperature;
-    lstate.Magnetometer = mag;    
-    UpdatedState.SetState(lstate);
-}
-
-void SensorFusion::handleExposure(const MessageExposureFrame& msg)
-{
-    NextExposureRecord.ExposureCounter = msg.CameraFrameCount;
-    NextExposureRecord.ExposureTime = msg.CameraTimeSeconds;
-    NextExposureRecord.WorldFromImu = WorldFromImu;
-    NextExposureRecord.ImuOnlyDelta.TimeInSeconds = msg.CameraTimeSeconds - LastMessageExposureFrame.CameraTimeSeconds;
-    ExposureRecordHistory.PushBack(NextExposureRecord);
-
-    // Every new exposure starts from zero
-    NextExposureRecord = ExposureRecord(); 
-    LastMessageExposureFrame = msg;
-}
-
-// If you have a known-good pose, this sets the neck pivot position.
-void SensorFusion::setNeckPivotFromPose(Transformd const &worldFromImu)
-{
-    WorldFromNeck = worldFromImu * ImuFromCpf * CpfFromNeck;
-}
-
-// These two functions need to be moved into Quat class
-// Compute a rotation required to transform "from" into "to". 
-Quatd vectorAlignmentRotation(const Vector3d &from, const Vector3d &to)
-{
-    Vector3d axis = from.Cross(to);
-    if (axis.LengthSq() == 0)
-        // this handles both collinear and zero-length input cases
-        return Quatd();
-    double angle = from.Angle(to);
-    return Quatd(axis, angle);
-}
-
-// Compute the part of the quaternion that rotates around Y axis
-Quatd extractYawRotation(const Quatd &error)
-{
-    if (error.y == 0)
-        return Quatd();
-    double phi = atan2(error.w, error.y);
-    double alpha = Mathd::Pi - 2 * phi;
-    return Quatd(Axis_Y, alpha);
-}
-
-void SensorFusion::applyPositionCorrection(double deltaT)
-{
-    // Each component of gainPos is equivalent to a Kalman gain of (sigma_process / sigma_observation)
-	const Vector3d gainPos = Vector3d(10, 10, 8);
-    const Vector3d gainVel = gainPos.EntrywiseMultiply(gainPos) * 0.5;
-    const Vector3d gainAccel = gainVel * 0.5;
-    const double snapThreshold = 0.1; // Large value (previously 0.01, which caused frequent jumping)
-
-    Vector3d correctionPos, correctionVel;
-    if (VisionError.Pose.Translation.LengthSq() > (snapThreshold * snapThreshold) ||
-        !(UpdatedState.GetState().StatusFlags & Status_PositionTracked))
-    {
-        // high error or just reacquired position from vision - apply full correction
-
-        // to know where we are right now, take the vision pose (which is slightly old)
-        // and update it using the imu data since then
-        PoseStated worldFromImuVision = WorldFromCamera * CameraFromImu;
-        for (unsigned int i = 0; i < ExposureRecordHistory.GetSize(); i++)
-            worldFromImuVision.AdvanceByDelta(ExposureRecordHistory.PeekFront(i).ImuOnlyDelta);
-        worldFromImuVision.AdvanceByDelta(NextExposureRecord.ImuOnlyDelta);
-
-        correctionPos = worldFromImuVision.Pose.Translation - WorldFromImu.Pose.Translation;
-        correctionVel = worldFromImuVision.LinearVelocity - WorldFromImu.LinearVelocity;
-        AccelOffset   = Vector3d();
-    }
-    else
-    {
-        correctionPos = VisionError.Pose.Translation.EntrywiseMultiply(gainPos) * deltaT;
-        correctionVel = VisionError.Pose.Translation.EntrywiseMultiply(gainVel) * deltaT;
-        AccelOffset  += VisionError.Pose.Translation.EntrywiseMultiply(gainAccel) * deltaT;
-    }
-
-    WorldFromImu.Pose.Translation += correctionPos;
-    WorldFromImu.LinearVelocity += correctionVel;
-
-    // Update the exposure records so that we don't apply the same correction twice
-    LastVisionExposureRecord.WorldFromImu.Pose.Translation += correctionPos;
-    LastVisionExposureRecord.WorldFromImu.LinearVelocity += correctionVel;
-    for (unsigned int i = 0; i < ExposureRecordHistory.GetSize(); i++)
-    {
-        PoseStated& state = ExposureRecordHistory.PeekBack(i).WorldFromImu;
-        state.Pose.Translation += correctionPos;
-        state.LinearVelocity += correctionVel;
-    }
-}
-
-void SensorFusion::applyVisionYawCorrection(double deltaT)
-{
-    const double gain = 0.25;
-    const double snapThreshold = 0.1;
-
-    Quatd yawError = extractYawRotation(VisionError.Pose.Rotation);
-
-    Quatd correction;
-    if (Alg::Abs(yawError.w) < cos(snapThreshold / 2)) // angle(yawError) > snapThreshold
-        // high error, jump to the vision position
-        correction = yawError;
-    else
-        correction = yawError.Nlerp(Quatd(), gain * deltaT);
-
-    WorldFromImu.Pose.Rotation = correction * WorldFromImu.Pose.Rotation;
-
-    // Update the exposure records so that we don't apply the same correction twice
-    LastVisionExposureRecord.WorldFromImu.Pose.Rotation = correction * LastVisionExposureRecord.WorldFromImu.Pose.Rotation;
-    for (unsigned int i = 0; i < ExposureRecordHistory.GetSize(); i++)
-    {
-        PoseStated& state = ExposureRecordHistory.PeekBack(i).WorldFromImu;
-        state.Pose.Rotation = correction * state.Pose.Rotation;
-    }
-}
-
-void SensorFusion::applyMagYawCorrection(Vector3d mag, double deltaT)
-{
-    const double minMagLengthSq   = Mathd::Tolerance; // need to use a real value to discard very weak fields
-    const double maxMagRefDist    = 0.1;
-    const double maxTiltError     = 0.05;
-    const double proportionalGain = 0.01;
-    const double integralGain     = 0.0005;
-
-    Vector3d magInWorldFrame = WorldFromImu.Pose.Rotate(mag);
-    // verify that the horizontal component is sufficient
-    if (magInWorldFrame.x * magInWorldFrame.x + magInWorldFrame.z * magInWorldFrame.z < minMagLengthSq)
-        return;
-    magInWorldFrame.Normalize();
-
-    // Delete a bad point
-    if (MagRefIdx >= 0 && MagRefs[MagRefIdx].Score < 0)
-    {
-        MagRefs.RemoveAtUnordered(MagRefIdx);
-        MagRefIdx = -1;
-    }
-
-    // Update the reference point if needed
-    if (MagRefIdx < 0 || mag.Distance(MagRefs[MagRefIdx].InImuFrame) > maxMagRefDist)
-    {
-        // Find a new one
-        MagRefIdx = -1;
-        double bestDist = maxMagRefDist;
-        for (unsigned int i = 0; i < MagRefs.GetSize(); i++)
-        {
-            double dist = mag.Distance(MagRefs[i].InImuFrame);
-            if (bestDist > dist)
-            {
-                bestDist = dist;
-                MagRefIdx = i;
-            }
-        }
-
-        // Create one if needed
-        if (MagRefIdx < 0 && MagRefs.GetSize() < MagMaxReferences)
-		{
-            MagRefs.PushBack(MagReferencePoint(mag, WorldFromImu.Pose, 1000));
-		}
-    }
-
-    if (MagRefIdx >= 0)
-    {
-        Vector3d magRefInWorldFrame = MagRefs[MagRefIdx].WorldFromImu.Rotate(MagRefs[MagRefIdx].InImuFrame);
-        magRefInWorldFrame.Normalize();
-
-        // If the vertical angle is wrong, decrease the score and do nothing
-        if (Alg::Abs(magRefInWorldFrame.y - magInWorldFrame.y) > maxTiltError)
-        {
-            MagRefs[MagRefIdx].Score -= 1;
-            return;
-        }
-
-        MagRefs[MagRefIdx].Score += 2;
-#if 0
-        // this doesn't seem to work properly, need to investigate
-        Quatd error = vectorAlignmentRotation(magW, magRefW);
-        Quatd yawError = extractYawRotation(error);
-#else
-        // Correction is computed in the horizontal plane
-        magInWorldFrame.y = magRefInWorldFrame.y = 0;
-        Quatd yawError = vectorAlignmentRotation(magInWorldFrame, magRefInWorldFrame);
-#endif                                                 
-        Quatd correction = yawError.Nlerp(Quatd(), proportionalGain * deltaT) *
-                           MagCorrectionIntegralTerm.Nlerp(Quatd(), deltaT);
-        MagCorrectionIntegralTerm = MagCorrectionIntegralTerm * yawError.Nlerp(Quatd(), integralGain * deltaT);
-
-        WorldFromImu.Pose.Rotation = correction * WorldFromImu.Pose.Rotation;
-    }
-}
-
-void SensorFusion::applyTiltCorrection(double deltaT)
-{
-    const double gain = 0.25;
-    const double snapThreshold = 0.1;
-    const Vector3d up(0, 1, 0);
-
-    Vector3d accelInWorldFrame = WorldFromImu.Pose.Rotate(FAccelInImuFrame.GetFilteredValue());
-    Quatd error = vectorAlignmentRotation(accelInWorldFrame, up);
-
-    Quatd correction;
-    if (FAccelInImuFrame.GetSize() == 1 || 
-        ((Alg::Abs(error.w) < cos(snapThreshold / 2) && FAccelInImuFrame.Confidence() > 0.75)))
-        // full correction for start-up
-        // or large error with high confidence
-        correction = error;
-    else if (FAccelInImuFrame.Confidence() > 0.5)
-        correction = error.Nlerp(Quatd(), gain * deltaT);
-    else
-        // accelerometer is unreliable due to movement
-        return;
-
-    WorldFromImu.Pose.Rotation = correction * WorldFromImu.Pose.Rotation;
-}
-
-void SensorFusion::applyCameraTiltCorrection(Vector3d accel, double deltaT)
-{
-    const double snapThreshold = 0.02; // in radians
-    const double maxCameraPositionOffset = 0.2;
-    const Vector3d up(0, 1, 0), forward(0, 0, -1);
-
-    // for startup use filtered value instead of instantaneous for stability
-    if (FAccelInCameraFrame.IsEmpty())
-        accel = FAccelInImuFrame.GetFilteredValue();
-
-    Transformd cameraFromImu = WorldFromCamera.Inverted() * VisionError.Pose * WorldFromImu.Pose;
-    // this is what the hypothetical camera-mounted accelerometer would show
-    Vector3d accelInCameraFrame = cameraFromImu.Rotate(accel);
-    FAccelInCameraFrame.Update(accelInCameraFrame, deltaT);
-    Vector3d cameraAccelInWorldFrame = WorldFromCamera.Rotate(FAccelInCameraFrame.GetFilteredValue());
-   
-    Quatd error1 = vectorAlignmentRotation(cameraAccelInWorldFrame, up);
-    // cancel out yaw rotation
-    Vector3d forwardCamera = (error1 * WorldFromCamera.Rotation).Rotate(forward);
-    forwardCamera.y = 0;
-    Quatd error2 = vectorAlignmentRotation(forwardCamera, forward);
-    // combined error
-    Quatd error = error2 * error1;
-
-    double confidence = FAccelInCameraFrame.Confidence();
-    // penalize the confidence if looking away from the camera
-    // TODO: smooth fall-off
-    if (CameraFromImu.Pose.Rotate(forward).Angle(forward) > 1)
-        confidence *= 0.5;
-
-	//Convenient global variable to temporarily extract this data.
-	TPH_CameraPoseConfidence = confidence;
-	//Allow override of confidence threshold
-	double confidenceThreshold = 0.75f;
-	if (TPH_CameraPoseConfidenceThresholdOverrideIfNonZero)
-    {
-		confidenceThreshold = TPH_CameraPoseConfidenceThresholdOverrideIfNonZero;
-	}
-
-    Quatd correction;
-    if (FAccelInCameraFrame.GetSize() == 1 ||
-        confidence > WorldFromCameraConfidence + 0.2 ||
-        // disabled due to false positives when moving side to side
-//        (Alg::Abs(error.w) < cos(5 * snapThreshold / 2) && confidence > 0.55) ||    
-        (Alg::Abs(error.w) < cos(snapThreshold / 2) && confidence > confidenceThreshold))
-    {
-        // large error with high confidence
-        correction = error;
-        // update the confidence level
-        WorldFromCameraConfidence = confidence;
-    }
-    else
-    {
-        // accelerometer is unreliable due to movement
-        return;
-    }
-
-    Transformd newWorldFromCamera(correction * WorldFromCamera.Rotation, Vector3d());
-
-    // compute a camera position change that together with the camera rotation would result in zero player movement
-    newWorldFromCamera.Translation += (WorldFromCamera * CameraFromImu.Pose).Translation -
-        (newWorldFromCamera * CameraFromImu.Pose).Translation;
-    // if the new position is too far, reset to default 
-    // (can't hide the rotation, might as well use it to reset the position)
-    if (newWorldFromCamera.Translation.DistanceSq(DefaultWorldFromCamera.Translation) > maxCameraPositionOffset * maxCameraPositionOffset)
-        newWorldFromCamera.Translation = DefaultWorldFromCamera.Translation;
-
-    WorldFromCamera = newWorldFromCamera;
-
-	//Convenient global variable to temporarily extract this data.
-	TPH_CameraPoseOrientationWxyz[0] = (float) WorldFromCamera.Rotation.w;
-	TPH_CameraPoseOrientationWxyz[1] = (float) WorldFromCamera.Rotation.x;
-	TPH_CameraPoseOrientationWxyz[2] = (float) WorldFromCamera.Rotation.y;
-	TPH_CameraPoseOrientationWxyz[3] = (float) WorldFromCamera.Rotation.z;
-}
-
-void SensorFusion::applyFocusCorrection(double deltaT)
-{
-	Vector3d up = Vector3d(0, 1, 0);
-	double gain = 0.01;
-	Vector3d currentDir = WorldFromImu.Pose.Rotate(Vector3d(0, 0, 1));
-
-	Vector3d focusYawComponent = FocusDirection.ProjectToPlane(up);
-	Vector3d currentYawComponent = currentDir.ProjectToPlane(up);
-
-	double angle = focusYawComponent.Angle(currentYawComponent);
-
-	if( angle > FocusFOV )
-	{
-		Quatd yawError;
-		if ( FocusFOV != 0.0f)
-		{
-			Vector3d lFocus = Quatd(up, -FocusFOV).Rotate(focusYawComponent);
-			Vector3d rFocus = Quatd(up, FocusFOV).Rotate(focusYawComponent);
-			double lAngle = lFocus.Angle(currentYawComponent);
-			double rAngle = rFocus.Angle(currentYawComponent);
-			if(lAngle < rAngle)
-			{
-				yawError = vectorAlignmentRotation(currentDir, lFocus);
-			} 
-            else
-			{
-				yawError = vectorAlignmentRotation(currentDir, rFocus);
-			}
-		} 
-        else
-		{
-			yawError = vectorAlignmentRotation(currentYawComponent, focusYawComponent);
-		}
-
-		Quatd correction = yawError.Nlerp(Quatd(), gain * deltaT);
-        WorldFromImu.Pose.Rotation = correction * WorldFromImu.Pose.Rotation;
-	}
-}
-
-//------------------------------------------------------------------------------------
-// Focus filter setting functions
-
-void SensorFusion::SetFocusDirection()
-{
-	SetFocusDirection(WorldFromImu.Pose.Rotate(Vector3d(0.0, 0.0, 1.0)));
-}
-
-void SensorFusion::SetFocusDirection(Vector3d direction)
-{
-	FocusDirection = direction;
-}
-
-void SensorFusion::SetFocusFOV(double fov)
-{
-	OVR_ASSERT(fov >= 0.0);
-	FocusFOV = fov;
-}
-
-void SensorFusion::ClearFocus()
-{
-	FocusDirection = Vector3d(0.0, 0.0, 0.0);
-	FocusFOV = 0.0f;
-}
-
-//-------------------------------------------------------------------------------------
-// Head model functions.
-
-// Sets up head-and-neck model and device-to-pupil dimensions from the user's profile.
-void SensorFusion::SetUserHeadDimensions(Profile const &profile, HmdRenderInfo const &hmdRenderInfo)
-{
-    float neckeye[2];
-    int count = profile.GetFloatValues(OVR_KEY_NECK_TO_EYE_DISTANCE, neckeye, 2);
-    // Make sure these are vaguely sensible values.
-    if (count == 2)
-    {
-        OVR_ASSERT ( ( neckeye[0] > 0.05f ) && ( neckeye[0] < 0.5f ) );
-        OVR_ASSERT ( ( neckeye[1] > 0.05f ) && ( neckeye[1] < 0.5f ) );
-        SetHeadModel ( Vector3f ( 0.0, neckeye[1], -neckeye[0] ) );
-    }
-
-    // Find the distance from the center of the screen to the "center eye"
-    // This center eye is used by systems like rendering & audio to represent the player,
-    // and they will handle the offsets needed from there to each actual eye.
-
-    // HACK HACK HACK
-    // We know for DK1 the screen->lens surface distance is roughly 0.049f, and that the faceplate->lens is 0.02357f.
-    // We're going to assume(!!!!) that all HMDs have the same screen->faceplate distance.
-    // Crystal Cove was measured to be roughly 0.025 screen->faceplate which agrees with this assumption.
-    // TODO: do this properly!  Update:  Measured this at 0.02733 with a CC prototype, CES era (PT7), on 2/19/14 -Steve
-    float screenCenterToMidplate = 0.02733f;
-    float centerEyeRelief = hmdRenderInfo.GetEyeCenter().ReliefInMeters;
-    float centerPupilDepth = screenCenterToMidplate + hmdRenderInfo.LensSurfaceToMidplateInMeters + centerEyeRelief;
-    SetCenterPupilDepth ( centerPupilDepth );
-
-    Recording::GetRecorder().RecordUserParams(GetHeadModel(), GetCenterPupilDepth());
-}
-
-Vector3f SensorFusion::GetHeadModel() const
-{
-    return (Vector3f)CpfFromNeck.Inverted().Translation;
-}
-
-void SensorFusion::SetHeadModel(const Vector3f &headModel, bool resetNeckPivot /*= true*/ )
-{
-    Lock::Locker lockScope(pHandler->GetHandlerLock());
-    // The head model should look something like (0, 0.12, -0.12), so
-    // these asserts are to try to prevent sign problems, as
-    // they can be subtle but nauseating!
-    OVR_ASSERT ( headModel.y > 0.0f );
-    OVR_ASSERT ( headModel.z < 0.0f );
-    CpfFromNeck = Transformd(Quatd(), (Vector3d)headModel).Inverted();
-    if ( resetNeckPivot )
-    {
-        setNeckPivotFromPose ( WorldFromImu.Pose );
-    }
-}
-
-float SensorFusion::GetCenterPupilDepth() const
-{
-    return CenterPupilDepth;
-}
-
-void SensorFusion::SetCenterPupilDepth(float centerPupilDepth)
-{
-    CenterPupilDepth = centerPupilDepth;
-
-    Transformd screenFromCpf(Quatd(), Vector3d(0, 0, centerPupilDepth));
-    ImuFromCpf = ImuFromScreen * screenFromCpf;
-	
-    setNeckPivotFromPose ( WorldFromImu.Pose );
-}
-
-//-------------------------------------------------------------------------------------
-
-// This is a "perceptually tuned predictive filter", which means that it is optimized
-// for improvements in the VR experience, rather than pure error.  In particular,
-// jitter is more perceptible at lower speeds whereas latency is more perceptible
-// after a high-speed motion.  Therefore, the prediction interval is dynamically
-// adjusted based on speed.  Significant more research is needed to further improve
-// this family of filters.
-static Transform<double> calcPredictedPose(const PoseState<double>& poseState, double predictionDt)
-{
-    Transform<double> pose   = poseState.Pose;
-	const double linearCoef  = 1.0;
-	Vector3d angularVelocity = poseState.AngularVelocity;
-	double   angularSpeed    = angularVelocity.Length();
-
-	// This could be tuned so that linear and angular are combined with different coefficients
-	double speed             = angularSpeed + linearCoef * poseState.LinearVelocity.Length();
-
-	const double slope       = 0.2; // The rate at which the dynamic prediction interval varies
-	double candidateDt       = slope * speed; // TODO: Replace with smoothstep function
-
-	double dynamicDt         = predictionDt;
-
-	// Choose the candidate if it is shorter, to improve stability
-	if (candidateDt < predictionDt)
-		dynamicDt = candidateDt;
-
-    if (angularSpeed > 0.001)
-        pose.Rotation = pose.Rotation * Quatd(angularVelocity, angularSpeed * dynamicDt);
-
-    pose.Translation += poseState.LinearVelocity * dynamicDt;
-
-    return pose;
-}
-
-
-Transformf SensorFusion::GetPoseAtTime(double absoluteTime) const
-{
-    SensorState ss = GetSensorStateAtTime ( absoluteTime );
-    return ss.Predicted.Pose;
-}
-
-
-SensorState SensorFusion::GetSensorStateAtTime(double absoluteTime) const
-{          
-     const LocklessState lstate = UpdatedState.GetState();
-     // Delta time from the last available data
-     const double pdt = absoluteTime - lstate.State.TimeInSeconds;
-     
-     SensorState ss;
-     ss.Recorded     = PoseStatef(lstate.State);
-     ss.Temperature  = lstate.Temperature;
-     ss.Magnetometer = Vector3f(lstate.Magnetometer);
-     ss.StatusFlags  = lstate.StatusFlags;
-
-     ss.Predicted               = ss.Recorded;
-     ss.Predicted.TimeInSeconds = absoluteTime;
-    
-     // Do prediction logic and ImuFromCpf transformation
-     ss.Recorded.Pose  = Transformf(lstate.State.Pose * ImuFromCpf);
-     ss.Predicted.Pose = Transformf(calcPredictedPose(lstate.State, pdt) * ImuFromCpf);
-     return ss;
-}
-
-unsigned SensorFusion::GetStatus() const
-{
-    return UpdatedState.GetState().StatusFlags;
-}
-
-//-------------------------------------------------------------------------------------
-
-void SensorFusion::OnMessage(const MessageBodyFrame& msg)
-{
-    OVR_ASSERT(!IsAttachedToSensor());
-    handleMessage(msg);
-}
-
-//-------------------------------------------------------------------------------------
-
-void SensorFusion::BodyFrameHandler::OnMessage(const Message& msg)
-{
-	Recording::GetRecorder().RecordMessage(msg);
-    if (msg.Type == Message_BodyFrame)
-        pFusion->handleMessage(static_cast<const MessageBodyFrame&>(msg));
-    if (msg.Type == Message_ExposureFrame)
-        pFusion->handleExposure(static_cast<const MessageExposureFrame&>(msg));
-}
-
-} // namespace OVR