/// <summary>
/// Initializes a new instance of the <see cref="GazeHidPositionsParser"/> class.
/// </summary>
/// <param name="gazeDevice"><see cref="GazeDevicePreview"/> used to parse.</param>
public GazeHidPositionsParser(GazeDevicePreview gazeDevice)
{
_leftEyePositionParser = new GazeHidPositionParser(gazeDevice, (ushort)GazeHidUsages.Usage_LeftEyePosition);
_rightEyePositionParser = new GazeHidPositionParser(gazeDevice, (ushort)GazeHidUsages.Usage_RightEyePosition);
_headPositionParser = new GazeHidPositionParser(gazeDevice, (ushort)GazeHidUsages.Usage_HeadPosition);
_headRotationParser = new GazeHidRotationParser(gazeDevice, (ushort)GazeHidUsages.Usage_HeadDirectionPoint);
}
/// <summary>
/// Check if eye-tracking device is viable.
/// </summary>
/// <param name="gazeDevice">Reference to eye-tracking device.</param>
/// <returns>True, if device is viable; otherwise, false.</returns>
private bool IsSupportedDevice(GazeDevicePreview gazeDevice)
{
TrackerState.Text = gazeDevice.ConfigurationState.ToString();
return(gazeDevice.CanTrackEyes &&
gazeDevice.ConfigurationState ==
GazeDeviceConfigurationStatePreview.Ready);
}
/// <summary>
/// Initializes a new instance of the <see cref="GazeHidRotationParser"/> class.
/// </summary>
/// <param name="gazeDevice"><see cref="GazeDevicePreview"/> used to parse.</param>
/// <param name="usage">The <see cref="GazeHidUsages"/> used to parse.</param>
public GazeHidRotationParser(GazeDevicePreview gazeDevice, ushort usage)
{
_usage = usage;
// Find all the rotation usages from the device's
// descriptor and store them for easy access
_x = GazeHidParsersHelpers.GetGazeUsageFromCollectionId(gazeDevice, (ushort)GazeHidUsages.Usage_RotationX, _usage);
_y = GazeHidParsersHelpers.GetGazeUsageFromCollectionId(gazeDevice, (ushort)GazeHidUsages.Usage_RotationY, _usage);
_z = GazeHidParsersHelpers.GetGazeUsageFromCollectionId(gazeDevice, (ushort)GazeHidUsages.Usage_RotationZ, _usage);
}
public GazeRotationHidParser(GazeDevicePreview gazeDevice, UInt16 usage)
{
_usage = usage;
// Find all the head rotation usage from the device's
// descriptor and store them for easy access
_X = GetGazeUsageFromCollectionId(gazeDevice, GazeExtendedUsages.Usage_RotationX, _usage);
_Y = GetGazeUsageFromCollectionId(gazeDevice, GazeExtendedUsages.Usage_RotationY, _usage);
_Z = GetGazeUsageFromCollectionId(gazeDevice, GazeExtendedUsages.Usage_RotationZ, _usage);
}
/// <summary>
/// Initialize gaze tracking.
/// </summary>
/// <param name="gazeDevice"></param>
private async void TryEnableGazeTrackingAsync(GazeDevicePreview gazeDevice)
{
// If eye-tracking device is ready, declare event handlers and start tracking.
if (IsSupportedDevice(gazeDevice))
{
timerGaze.Interval = new TimeSpan(0, 0, 0, 0, 20);
timerGaze.Tick += TimerGaze_Tick;
SetGazeTargetLocation();
// This must be called from the UI thread.
gazeInputSource = GazeInputSourcePreview.GetForCurrentView();
gazeInputSource.GazeEntered += GazeEntered;
gazeInputSource.GazeMoved += GazeMoved;
gazeInputSource.GazeExited += GazeExited;
}
// Notify if device calibration required.
else if (gazeDevice.ConfigurationState ==
GazeDeviceConfigurationStatePreview.UserCalibrationNeeded ||
gazeDevice.ConfigurationState ==
GazeDeviceConfigurationStatePreview.ScreenSetupNeeded)
{
// Device isn't calibrated, so invoke the calibration handler.
System.Diagnostics.Debug.WriteLine(
"Your device needs to calibrate. Please wait for it to finish.");
await gazeDevice.RequestCalibrationAsync();
}
// Notify if device calibration underway.
else if (gazeDevice.ConfigurationState ==
GazeDeviceConfigurationStatePreview.Configuring)
{
// Device is currently undergoing calibration.
// A device update is sent when calibration complete.
System.Diagnostics.Debug.WriteLine(
"Your device is being configured. Please wait for it to finish");
}
// Device is not viable.
else if (gazeDevice.ConfigurationState == GazeDeviceConfigurationStatePreview.Unknown)
{
// Notify if device is in unknown state.
// Reconfigure/recalbirate the device.
System.Diagnostics.Debug.WriteLine(
"Your device is not ready. Please set up your device or reconfigure it.");
}
}
private static HidNumericControlDescription GetGazeUsageFromCollectionId(GazeDevicePreview gazeDevice, UInt16 childUsageId, UInt16 parentUsageId)
{
var numericControls = gazeDevice.GetNumericControlDescriptions(
GazeExtendedUsages.UsagePage_EyeHeadTracker, childUsageId);
for (int i = 0; i < numericControls.Count; i++)
{
var parentCollections = numericControls[i].ParentCollections;
if (parentCollections.Count > 0 &&
parentCollections[0].UsagePage == GazeExtendedUsages.UsagePage_EyeHeadTracker &&
parentCollections[0].UsageId == parentUsageId)
{
return(numericControls[i]);
}
}
return(null);
}
public static HidNumericControlDescription GetGazeUsageFromCollectionId(
GazeDevicePreview gazeDevice,
ushort childUsageId,
ushort parentUsageId)
{
var numericControls = gazeDevice.GetNumericControlDescriptions(
(ushort)GazeHidUsages.UsagePage_EyeHeadTracker, childUsageId);
for (int i = 0; i < numericControls.Count; i++)
{
var parentCollections = numericControls[i].ParentCollections;
if (parentCollections.Count > 0 &&
parentCollections[0].UsagePage == (ushort)GazeHidUsages.UsagePage_EyeHeadTracker &&
parentCollections[0].UsageId == parentUsageId)
{
return(numericControls[i]);
}
}
return(null);
}
private void Log(string message, GazeDevicePreview device)
{
var identifiedMessage = $"{message}\tId={device.Id}, State={device.ConfigurationState}, Eyes={device.CanTrackEyes}, Head={device.CanTrackHead}";
Log(identifiedMessage);
}
private bool IsSupportedDevice(GazeDevicePreview gazeDevice)
{
return(gazeDevice.CanTrackEyes &&
gazeDevice.ConfigurationState ==
GazeDeviceConfigurationStatePreview.Ready);
}
