DevelexCore

A TypeScript/JavaScript SDK for integrating eye tracking and gaze-based interactions into web applications. It is part of the develex ecosystem and focuses on gaze data processing for dyslexia interventions and gaze based interactions in web applications.

Quick Start

npm install develex-js-sdk

import { GazeManager } from 'develex-js-sdk';

// Create the gaze manager, which serves as the main entry point for all gaze functionality
const gazeManager = new GazeManager();

// Configure and connect to an eye tracker
gazeManager.createInput({
  tracker: 'gazepoint',
  uri: 'ws://localhost:4242',
  fixationDetection: 'device'
});
await gazeManager.connect();
await gazeManager.subscribe();
await gazeManager.start();

// Calibrate window coordinates (essential for proper gaze tracking)
await gazeManager.setWindowCalibration(
  { clientX: 100, clientY: 100, screenX: 150, screenY: 200 },
  { screen: { width: 1920, height: 1080 } }
);

// Register elements for gaze interaction
gazeManager.register({
  interaction: 'dwell',
  element: document.getElementById('myButton'),
  settings: {
    dwellTime: 1000,
    bufferSize: 100,
    toleranceTime: 150,
    onDwellProgress: (event) => {},
    onDwellFinish: (event) => console.log('User dwelled on button!'),
    onDwellCancel: (event) => {}
  }
});

Documentation

• Getting Started Guide - Setup instructions and basic usage
• GazeManager Reference - API documentation for the main GazeManager class
• Data Structures Reference - Interface and type definitions
• Interaction Types Guide - Available gaze interaction types

Core Features

Multi-Device Support

• GazePoint - Professional eye tracking devices
• EyeLogic - Consumer-grade eye trackers
• ASEE - Advanced eye tracking systems
• Dummy Input - Testing and development

Gaze Interaction Types

• Fixation Detection - Identifies when gaze stabilises on elements
• Saccade Tracking - Monitors rapid eye movements between points
• Dwell Time - Tracks how long gaze remains on elements
• Intersection Detection - Real-time gaze-element intersection
• Validation - Accuracy and precision measurements

Technical Features

• Real-time Processing - Processes gaze data as it arrives, with configurable detection algorithms
• Window Calibration - Maps screen coordinates to browser window coordinates
• Fixation Analysis - Implements fixation detection algorithms for gaze analysis
• Event-Driven Architecture - Uses an event system for handling gaze interactions

Architecture

The SDK is built around the GazeManager class, which provides a unified interface for all gaze functionality. The main components include:

• GazeManager - Main class that coordinates all gaze operations and provides the primary API
• GazeInput - Handles communication with different eye tracking devices
• GazeInteraction - Contains modules for detecting various types of gaze interactions
• GazeFixationDetector - Implements algorithms for detecting eye fixations
• GazeWindowCalibrator - Manages coordinate system calibration between screen and browser window

Most applications only need to use the GazeManager class, which provides a simplified interface for common operations.

Testing

A separate testing interface exists for validating eye tracker functionality. To use it:

1. Start your eye tracking controller software (such as GazePoint Control)
2. Start the develex-bridge application
3. Visit the testing website to validate that everything works correctly

Note: This testing interface is separate from the main SDK and includes additional components for demonstration purposes.

Development

# Install dependencies
npm install

# Start development server
npm run dev

# Build for production
npm run build

# Run tests
npm test

# Lint code
npm run lint

Publishing

The package publishes to npm automatically when changes are pushed to the main branch. You can also publish manually:

npm publish

License

This project is part of the develex ecosystem. See the main develex repository for licensing information.

Related Projects

• develex-bridge - Bridge service for eye tracker communication