libGDX GWT Backend

The libGDX GWT Backend enables Java-based libGDX games to run in web browsers by transpiling Java code to JavaScript using Google Web Toolkit (GWT). It provides complete implementations of all core libGDX interfaces optimized for web browser environments, including WebGL graphics rendering, HTML5/Web Audio API audio playback, DOM-based input handling, and browser-compatible file system access.

Package Information

• Package Name: gdx-backend-gwt
• Package Type: maven
• Language: Java
• Installation: Add dependency com.badlogicgames.gdx:gdx-backend-gwt:1.13.1

Core Imports

import com.badlogic.gdx.backends.gwt.GwtApplication;
import com.badlogic.gdx.backends.gwt.GwtApplicationConfiguration;

Basic Usage

import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.backends.gwt.GwtApplication;
import com.badlogic.gdx.backends.gwt.GwtApplicationConfiguration;

public class MyGameGwt extends GwtApplication {
    @Override
    public GwtApplicationConfiguration getConfig() {
        GwtApplicationConfiguration config = new GwtApplicationConfiguration(800, 600);
        config.disableAudio = false;
        config.antialiasing = true;
        return config;
    }

    @Override
    public ApplicationListener createApplicationListener() {
        return new MyGame();
    }
}

Architecture

The GWT backend implements the libGDX Application interface through several key components:

• Application Core: Entry point and lifecycle management through GwtApplication
• Graphics Subsystem: WebGL-based rendering through GwtGraphics and GL implementations
• Audio Subsystem: HTML5 Audio and Web Audio API integration
• Input Handling: DOM event-based mouse, keyboard, and touch input
• File System: Browser storage and asset management with preloading
• Networking: HTTP-only network operations through browser APIs

Capabilities

Application Setup

Core application initialization, configuration, and lifecycle management for web deployment.

public abstract class GwtApplication implements EntryPoint, Application {
    public abstract GwtApplicationConfiguration getConfig();
    public abstract ApplicationListener createApplicationListener();
}

Graphics and Rendering

WebGL-based graphics implementation with OpenGL ES 2.0/3.0 compatibility and browser-specific optimizations.

public class GwtGraphics extends AbstractGraphics {
    public int getWidth();
    public int getHeight();
    public GL20 getGL20();
    public GL30 getGL30();
}

Audio System

Dual audio implementation supporting both HTML5 Audio and Web Audio API for optimal cross-browser compatibility.

public interface GwtAudio extends Audio {
    Music newMusic(FileHandle file);
    Sound newSound(FileHandle file);
}

Input Handling

Comprehensive input support for mouse, keyboard, touch, and mobile device sensors with web-specific optimizations.

public interface GwtInput extends Input {
    // Standard Input methods plus web-specific extensions
    boolean isKeyPressed(int key);
    int getX();
    int getY();
    boolean isTouched();
}

File System and Assets

Browser-compatible file system with asset preloading capabilities and local storage integration.

public class GwtFiles implements Files {
    FileHandle internal(String path);
    FileHandle local(String path);
    boolean isExternalStorageAvailable();
}

Networking

HTTP-based networking implementation using browser APIs for web-compatible network operations.

public class GwtNet implements Net {
    void sendHttpRequest(HttpRequest httpRequest, HttpResponseListener httpResponseListener);
    void openURI(String URI);
}

Asset Preloading

Specialized asset preloading system for web deployment requirements with progress tracking and error handling.

public class Preloader {
    void preload(String path, PreloaderCallback callback);
    PreloaderState update();
}

Web Audio API

Advanced Web Audio API integration for improved audio performance and capabilities in modern browsers.

public class WebAudioAPIManager implements LifecycleListener {
    boolean isSupported();
    void createContext();
}

UI Widgets

Web-specific UI components for progress indicators, text input dialogs, and browser integration elements.

public interface ResizableWidget {
    void resize(int width, int height);
}