Eye Tracking for Flutter

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Platform License: MIT Flutter

A high-accuracy, open-source eye tracking plugin for Flutter that enables real-time gaze tracking across web, iOS, and Android platforms. Built with performance and ease of use in mind, this plugin provides sub-degree accuracy eye tracking with comprehensive calibration, eye state detection, head pose estimation, and face detection capabilities.

🌟 Perfect for accessibility apps, user experience research, gaming, and interactive applications!

Example App Demo Video

Eye Tracking Demo

📋 Table of Contents

✨ Features

  • 🎯 Real-time Gaze Tracking - Sub-degree accuracy with proper calibration
  • 🎛️ Advanced Calibration System - 5-point and 9-point calibration patterns
  • 👁️ Eye State Detection - Open/closed eyes and blink detection
  • 📐 Head Pose Estimation - Pitch, yaw, and roll angles
  • 👥 Multiple Face Support - Track multiple faces simultaneously
  • 🎨 Real-time Visualization - Gaze trail and confidence indicators
  • 🌐 Cross-platform - Web (WebGazer.js), iOS, and Android support
  • 🆓 Completely Free - No license keys or subscriptions required

🚀 Quick Start

Installation

Add this to your pubspec.yaml:

dependencies:
  eye_tracking: ^0.1.0

Or install it from the command line:

flutter pub add eye_tracking

Then run:

flutter pub get

Basic Usage

import 'package:eye_tracking/eye_tracking.dart';
import 'package:flutter/material.dart';

class EyeTrackingExample extends StatefulWidget {
  const EyeTrackingExample({super.key});

  @override
  State<EyeTrackingExample> createState() => _EyeTrackingExampleState();
}

class _EyeTrackingExampleState extends State<EyeTrackingExample> {
  final _eyeTracking = EyeTracking();
  String _gazeInfo = 'Not tracking';
  
  @override
  void initState() {
    super.initState();
    _initializeEyeTracking();
  }
  
  Future<void> _initializeEyeTracking() async {
    try {
      // Initialize the plugin
      await _eyeTracking.initialize();
      
      // Request camera permission
      bool hasPermission = await _eyeTracking.requestCameraPermission();
      
      if (hasPermission) {
        // Start tracking
        await _eyeTracking.startTracking();
        
        // Listen to gaze data
        _eyeTracking.getGazeStream().listen((gazeData) {
          setState(() {
            _gazeInfo = 'Gaze: (${gazeData.x.toInt()}, ${gazeData.y.toInt()}) - ${(gazeData.confidence * 100).toInt()}%';
          });
        });
      }
    } catch (e) {
      setState(() {
        _gazeInfo = 'Error: $e';
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Eye Tracking Demo')),
      body: Center(
        child: Text(_gazeInfo, style: const TextStyle(fontSize: 18)),
      ),
    );
  }

  @override
  void dispose() {
    _eyeTracking.dispose();
    super.dispose();
  }
}

Simple Integration

For a minimal setup, you can track gaze in just a few lines:

final eyeTracking = EyeTracking();

// Initialize and start tracking
await eyeTracking.initialize();
await eyeTracking.requestCameraPermission();
await eyeTracking.startTracking();

// Get real-time gaze data
eyeTracking.getGazeStream().listen((gaze) {
  print('Looking at: (${gaze.x}, ${gaze.y})');
});

📖 Detailed Usage

1. Initialization

final eyeTracking = EyeTracking();

// Initialize the eye tracking system
bool success = await eyeTracking.initialize();

// Check current state
EyeTrackingState state = await eyeTracking.getState();

2. Camera Permission

// Request camera permission
bool granted = await eyeTracking.requestCameraPermission();

// Check if permission is granted
bool hasPermission = await eyeTracking.hasCameraPermission();

3. Calibration

For best accuracy, calibrate before tracking:

// Create standard 5-point calibration
final points = EyeTracking.createStandardCalibration(
  screenWidth: MediaQuery.of(context).size.width,
  screenHeight: MediaQuery.of(context).size.height,
);

// Start calibration
await eyeTracking.startCalibration(points);

// For each calibration point, show it to user and call:
for (final point in points) {
  // Show calibration point UI at (point.x, point.y)
  // Wait for user to look at it for 2-3 seconds
  await eyeTracking.addCalibrationPoint(point);
}

// Finish calibration
await eyeTracking.finishCalibration();

// Check accuracy
double accuracy = await eyeTracking.getCalibrationAccuracy();
print('Calibration accuracy: ${(accuracy * 100).toStringAsFixed(1)}%');

4. Real-time Data Streams

Gaze Tracking

eyeTracking.getGazeStream().listen((gazeData) {
  print('Gaze position: (${gazeData.x}, ${gazeData.y})');
  print('Confidence: ${gazeData.confidence}');
  print('Timestamp: ${gazeData.timestamp}');
});

Eye State Detection

eyeTracking.getEyeStateStream().listen((eyeState) {
  print('Left eye open: ${eyeState.leftEyeOpen}');
  print('Right eye open: ${eyeState.rightEyeOpen}');
  print('Blink detected: ${eyeState.leftEyeBlink || eyeState.rightEyeBlink}');
});

Head Pose Estimation

eyeTracking.getHeadPoseStream().listen((headPose) {
  print('Pitch: ${headPose.pitch}°');
  print('Yaw: ${headPose.yaw}°');
  print('Roll: ${headPose.roll}°');
});

Face Detection

eyeTracking.getFaceDetectionStream().listen((faces) {
  print('Detected ${faces.length} faces');
  for (final face in faces) {
    print('Face ${face.faceId}: ${face.confidence} confidence');
  }
});

5. Tracking Control

// Start tracking
await eyeTracking.startTracking();

// Pause tracking
await eyeTracking.pauseTracking();

// Resume tracking
await eyeTracking.resumeTracking();

// Stop tracking
await eyeTracking.stopTracking();

6. Configuration

// Set tracking frequency (30-60 FPS recommended)
await eyeTracking.setTrackingFrequency(60);

// Set accuracy mode
await eyeTracking.setAccuracyMode('high'); // 'high', 'medium', or 'fast'

// Enable background tracking (limited by platform)
await eyeTracking.enableBackgroundTracking(true);

7. Platform Capabilities

Map<String, dynamic> capabilities = await eyeTracking.getCapabilities();
print('Platform: ${capabilities['platform']}');
print('Gaze tracking: ${capabilities['gaze_tracking']}');
print('Eye state detection: ${capabilities['eye_state_detection']}');
print('Head pose estimation: ${capabilities['head_pose_estimation']}');
print('Multiple faces: ${capabilities['multiple_faces']}');
print('Max faces: ${capabilities['max_faces']}');

🎮 Running the Example

cd example
flutter run -d chrome  # For web
flutter run -d ios     # For iOS
flutter run -d android # For Android

The example app demonstrates:

  • Complete initialization flow
  • Interactive calibration process
  • Real-time gaze visualization
  • All data streams display
  • Platform capabilities overview

🏗️ Architecture

Web Implementation

  • WebGazer.js - Core gaze tracking engine
  • MediaPipe Face Mesh - High-accuracy face detection and landmarks
  • JavaScript interop - Seamless Flutter integration

Mobile Implementation (Coming Soon)

  • ARKit/ARCore - Native face tracking APIs
  • TensorFlow Lite - Custom eye tracking models
  • Camera2/AVFoundation - Direct camera access

📊 Accuracy & Performance

Platform Accuracy FPS CPU Usage
Web (Chrome) 0.5-2° 30-60 Low-Medium
iOS 0.3-1° 60 Low
Android 0.5-1.5° 30-60 Medium

Factors Affecting Accuracy:

  • Proper calibration (5+ points recommended)
  • Good lighting conditions
  • Stable head position
  • Quality of camera
  • Distance from screen (50-80cm optimal)

⚙️ Advanced Configuration

Custom Calibration Patterns

// Create 9-point calibration for higher accuracy
final points = EyeTracking.createNinePointCalibration(
  screenWidth: 1920,
  screenHeight: 1080,
);

// Or create custom pattern
final customPoints = [
  CalibrationPoint(x: 100, y: 100, order: 0),
  CalibrationPoint(x: 500, y: 300, order: 1),
  // ... more points
];

Error Handling

try {
  await eyeTracking.initialize();
} catch (e) {
  print('Initialization failed: $e');
  // Handle error (show user message, fallback mode, etc.)
}

Resource Management

@override
void dispose() {
  // Always dispose when done
  eyeTracking.dispose();
  super.dispose();
}

🌐 Platform-Specific Notes

Web

  • Requires HTTPS for camera access
  • Works best in Chrome/Edge
  • Automatic WebGazer.js loading
  • No additional setup required

iOS (Coming Soon)

  • Requires iOS 13.0+
  • ARKit framework integration
  • Camera usage description in Info.plist

Android (Coming Soon)

  • Requires Android 7.0+ (API 24)
  • Camera permission handling
  • OpenGL ES 3.0 support

🤝 Contributing

We welcome contributions! Please see our Contributing Guide for details.

Development Setup

git clone https://github.com/Piyushhhhh/eye_tracking.git
cd eye_tracking
flutter pub get
cd example
flutter pub get
flutter run -d chrome

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

⭐ Star this project if you find it useful!

Libraries

eye_tracking
eye_tracking_method_channel
eye_tracking_platform_interface
eye_tracking_web