ml_eye_tracking.h

Classes

	Name
struct	MLEyeTrackingStaticData Static information about the eye tracking.
struct	MLEyeTrackingStateEx Information about the state of the eye tracking system.

Types

	Name
typedef struct MLEyeTrackingStaticData	MLEyeTrackingStaticData Static information about the eye tracking.
typedef struct MLEyeTrackingStateEx	MLEyeTrackingStateEx Information about the state of the eye tracking system.

Enums

	Name
enum	MLEyeTrackingError { MLEyeTrackingError_None, MLEyeTrackingError_Generic, MLEyeTrackingError_Ensure32Bits = 0x7FFFFFFF }

Functions

	Name
void	MLEyeTrackingStateInit(MLEyeTrackingStateEx * inout_state) Initialize MLEyeTrackingStateEx with version.
MLResult	MLEyeTrackingCreate(MLHandle * out_handle) Creates an eye tracker.
MLResult	MLEyeTrackingDestroy(MLHandle eye_tracker) Destroys an eye tracker.
MLResult	MLEyeTrackingGetStaticData(MLHandle eye_tracker, MLEyeTrackingStaticData * out_data) Gets static information about the eye tracker.
MLResult	MLEyeTrackingGetStateEx(MLHandle eye_tracker, MLEyeTrackingStateEx * out_state) Gets information about the user's eyes.

Enums Documentation

MLEyeTrackingError

Enumerator	Value	Description
MLEyeTrackingError_None		No error, tracking is nominal.
MLEyeTrackingError_Generic		Eye Tracker failed.
MLEyeTrackingError_Ensure32Bits	0x7FFFFFFF	Ensure enum is represented as 32 bits.

A set of possible error codes that the Eye Tracking system can report.

---

Types Documentation

MLEyeTrackingStaticData

typedef struct MLEyeTrackingStaticData MLEyeTrackingStaticData;

Static information about the eye tracking.

Populate with MLEyeTrackingGetStaticData().

More Info

API Level:

• 20

---

MLEyeTrackingStateEx

typedef struct MLEyeTrackingStateEx MLEyeTrackingStateEx;

Information about the state of the eye tracking system.

This structure must be initialized by calling MLEyeTrackingStateInit() before use.

More Info

API Level:

• 26

---

Functions Documentation

MLEyeTrackingStateInit

static inline void MLEyeTrackingStateInit(
    MLEyeTrackingStateEx * inout_state
)

Initialize MLEyeTrackingStateEx with version.

Parameters

MLEyeTrackingStateEx *	inout_state	Set up the version for inout_state and zero all other fields.

API Level:

• 26

---

MLEyeTrackingCreate

MLResult MLEyeTrackingCreate(
    MLHandle * out_handle
)

Creates an eye tracker.

Parameters

MLHandle *	out_handle	A pointer to an MLHandle which will contain the handle of the eye tracker. If this operation fails, out_handle will be ML_INVALID_HANDLE.

Returns

MLResult	MLResult_InvalidParam	Failed to create eye tracker due to an invalid input parameter.
MLResult	MLResult_Ok	Successfully created eye tracker.
MLResult	MLResult_UnspecifiedFaiure	Failed to create eye tracker due to an unknown failure.
MLResult	MLResult_PermissionDenied	The application lacks permission.

Required Permissions:

• com.magicleap.permission.EYE_TRACKING (protection level: dangerous)

---

MLEyeTrackingDestroy

MLResult MLEyeTrackingDestroy(
    MLHandle eye_tracker
)

Destroys an eye tracker.

Parameters

MLHandle	eye_tracker	A handle to an Eye Tracker created by MLEyeTrackingCreate().

Returns

MLResult	MLResult_Ok	Successfully destroyed eye tracker.
MLResult	MLResult_UnspecifiedFaiure	Failed to destroy eye tracker due to an unknown failure.

Required Permissions:

• None

---

MLEyeTrackingGetStaticData

MLResult MLEyeTrackingGetStaticData(
    MLHandle eye_tracker,
    MLEyeTrackingStaticData * out_data
)

Gets static information about the eye tracker.

Parameters

MLHandle	eye_tracker	A handle to an Eye Tracker created by MLEyeTrackingCreate().
MLEyeTrackingStaticData *	out_data	Target to populate the data about the eye tracker.

Returns

MLResult	MLResult_InvalidParam	The out_data parameter was not valid (null).
MLResult	MLResult_Ok	Eye tracking static data was successfully received.
MLResult	MLResult_UnspecifiedFailure	Failed to receive eye tracking static data.

Required Permissions:

• None

API Level:

• 20

---

MLEyeTrackingGetStateEx

MLResult MLEyeTrackingGetStateEx(
    MLHandle eye_tracker,
    MLEyeTrackingStateEx * out_state
)

Gets information about the user's eyes.

Parameters

MLHandle	eye_tracker	A handle to an Eye Tracker created by MLEyeTrackingCreate().
MLEyeTrackingStateEx *	out_state	Information about the eyes.

Returns

MLResult	MLResult_InvalidParam	Failed to receive eye tracking state due to an invalid input parameter.
MLResult	MLResult_Ok	Successfully received eye tracking state.
MLResult	MLResult_UnspecifiedFailure	Failed to receive eye tracking state due to an unknown failure.

Required Permissions:

• None

NOTE: To ensure a clean trace of any eye state, it is important to monitor the confidence value of that eye to reject frames where confidence is 0 (or employ another fallback strategy like propagating the last high confidence value).

API Level:

• 9

---

Source code

// %BANNER_BEGIN%
// ---------------------------------------------------------------------
// %COPYRIGHT_BEGIN%
// Copyright (c) 2017 Magic Leap, Inc. All Rights Reserved.
// Use of this file is governed by the Software License Agreement,
// located here: https://www.magicleap.com/software-license-agreement-ml2
// Terms and conditions applicable to third-party materials accompanying
// this distribution may also be found in the top-level NOTICE file
// appearing herein.
// %COPYRIGHT_END%
// ---------------------------------------------------------------------
// %BANNER_END%

#pragma once

#include "ml_api.h"
#include "ml_types.h"

#include <string.h>

ML_EXTERN_C_BEGIN

typedef enum MLEyeTrackingError {
  MLEyeTrackingError_None,
  MLEyeTrackingError_Generic,
  MLEyeTrackingError_Ensure32Bits = 0x7FFFFFFF
} MLEyeTrackingError;

typedef struct MLEyeTrackingStaticData {
  MLCoordinateFrameUID vergence;

  MLCoordinateFrameUID left_center;

  MLCoordinateFrameUID right_center;
} MLEyeTrackingStaticData;

typedef struct MLEyeTrackingStateEx {
  uint32_t version;
  float vergence_confidence;
  float  left_center_confidence;
  float right_center_confidence;
  bool left_blink;
  bool right_blink;
  MLEyeTrackingError error;
  MLTime timestamp;
  float left_eye_openness;
  float right_eye_openness;
} MLEyeTrackingStateEx;

ML_STATIC_INLINE void MLEyeTrackingStateInit(MLEyeTrackingStateEx *inout_state) {
  if (inout_state) {
    memset(inout_state, 0, sizeof(MLEyeTrackingStateEx));
    inout_state->version = 2;
    inout_state->error = MLEyeTrackingError_None;
  }
}

ML_API MLResult ML_CALL MLEyeTrackingCreate(MLHandle *out_handle);

ML_API MLResult ML_CALL MLEyeTrackingDestroy(MLHandle eye_tracker);

ML_API MLResult ML_CALL MLEyeTrackingGetStaticData(MLHandle eye_tracker, MLEyeTrackingStaticData *out_data);

ML_API MLResult ML_CALL MLEyeTrackingGetStateEx(MLHandle eye_tracker, MLEyeTrackingStateEx *out_state);

ML_EXTERN_C_END