goo2d 0.0.2

A modular, low-level 2D game engine for Flutter featuring a component system, physics, advanced rendering, multi-device input, and built-in RPC for networked games.

[GOO2D]

GOO2D

Explore the Documentation »

⚠️ Under Heavy Development

GOO2D is currently in an early, active phase of heavy development. The APIs are subject to change rapidly. At this moment, we may not accept external contributions, as the core architecture is still being finalized.

A low-level 2D Entity-Component-System (ECS) engine built natively for Flutter.

GOO2D strips away standard UI boilerplate, providing the architectural primitives—GameObjects, Components, Coroutines, and Swept Collision—required to build games directly on the Flutter Canvas.

[GOO2D Battle Example]

Technical Highlights

• Strict Entity-Component Architecture: No inheritance spaghetti. Compose your game logic strictly through GameObjects and Components.
• Sequential Coroutines: Stop relying on messy Timers. Write state machines and timing logic sequentially using startCoroutine and native yield instructions like WaitForSeconds.
• Sweep-and-Prune Collision: Kinematic, AABB-based broadphase collision detection out of the box via BoxCollisionTrigger.
• Abstracted Input System: Map raw keyboard and pointer data to logical InputActions using composite bindings.

The 60-Second Quickstart

Building a game world uses the standard Flutter build syntax you already know, paired with a dedicated onUpdate game loop.

import 'package:flutter/material.dart';
import 'package:goo2d/goo2d.dart';

class Player extends StatefulGameWidget {
  const Player({super.key});
  @override
  PlayerState createState() => PlayerState();
}

class PlayerState extends GameState<Player> with Tickable {
  @override
  void initState() {
    super.initState();
    // 1. Attach components to give your object physical presence
    addComponent(
      ObjectTransform()..position = const Offset(50, 50),
      BoxCollisionTrigger()..rect = const Rect.fromLTWH(0, 0, 50, 50),
    );
  }

  @override
  void onUpdate(double dt) {
    // 2. The engine ticks this automatically every frame
    final transform = getComponent<ObjectTransform>();
    transform.position += Offset(100 * dt, 0); 
  }

  @override
  Iterable<Widget> build(BuildContext context) sync* {
    // 3. Yield your visual representation
    yield const Text('🚀', style: TextStyle(fontSize: 40));
  }
}

Mount the Engine

void main() {
  runApp(
    const MaterialApp(
      home: Scaffold(
        body: Game(
          // The Game widget handles the Ticker, Input, and Collision passes
          child: Player(), 
        ),
      ),
    ),
  );
}

Try the Example

The repository includes a complete top-down battle example demonstrating movement, rotation, shooting mechanics, HUD layering, and collision handling.

Run it directly from the /example directory:

cd example
flutter run