dartemis 0.9.0-nullsafety.0

An Entity System Framework for game development. Based on Artemis.

dartemis

Content

• About
• Getting Started
• Documentation
• Example Games

About

dartemis is a Dart port of the Entity System Framework Artemis.

The original has been written in Java by Arni Arent and Tiago Costa and can be found here: http://archive.is/1xRWW with the source available here: https://code.google.com/p/artemis-framework/

Ports for other languages are also available:

• C#: https://github.com/thelinuxlich/artemis_CSharp
• Python: https://github.com/kernhanda/PyArtemis

Some useful links about what an Entity System/Entity Component System is:

• http://piemaster.net/2011/07/entity-component-artemis/
• http://t-machine.org/index.php/2007/09/03/entity-systems-are-the-future-of-mmog-development-part-1/
• http://www.richardlord.net/blog/what-is-an-entity-framework

Getting started

1. Add dartemis to your project by adding it to your pubspec.yaml:

   dependencies:
     dartemis: any
   

2. Import it in your project:

   import 'package:dartemis/dartemis.dart';
   

3. Create a world:

   World world = World();
   

4. Create an entity from a list of components. Entities with different components will be processed by different systems:

   world.createEntity([
     Position(0, 0), 
     Velocity(1, 1),
   ]);
   

   A Component is a pretty simple structure and should not contain any logic:

   class Position extends Component {
       num x, y;
       Position(this.x, this.y);
   }
   

   Or if you want to use a PooledComponent:

   class Position extends PooledComponent {
       late num x, y;
      
       Position._();
       factory Position(num x, num y) {
           Position position = Pooled.of<Position>(() => Position._())
             ..x = x
             ..y = y;
           return position;
       }
   }
   

   By using a factory constructor and calling the static function Pooled.of, dartemis is able to reuse destroyed components and they will not be garbage collected.

5. Define a systems that should process your entities. The Aspect defines which components an entity needs to have in order to be processed by the system:

   class MovementSystem extends EntityProcessingSystem {
       late Mapper<Position> positionMapper;
       late Mapper<Velocity> velocityMapper;
   
       MovementSystem() : super(Aspect.forAllOf([Position, Velocity]));
   
       void initialize() {
         // initialize your system
         // Mappers, Systems and Managers have to be assigned here
         // see dartemis_builder if you don't want to write this code
         positionMapper = Mapper<Position>(world);
         velocityMapper = Mapper<Velocity>(world);
       }
   
       void processEntity(int entity) {
         Position position = positionMapper[entity];
         Velocity vel = velocityMapper[entity];
         position.x += vel.x;
         position.y += vel.y;
       }
   }
   

6. Add your system to the world:

   world.addSystem(MovementSystem());
   

7. Initialize the world:

   world.initialize();
   

8. In your game loop you then process your systems:

   world.process();
   

   If your game logic requires a delta you can set it by calling:

   world.delta = delta;
   

Documentation

API

Reference Manual

Example Games using dartemis

• darteroids - Very simple example included in the example folder of dartemis, (Source)
• Shapeocalypse - A fast paced reaction game using Angular, WebAudio and WebGL
• damacreat.io - An iogame similar to agar.io about creatures made of dark matter (circles) consuming dark energy (circles) and other dark matter creatures (circles), which can shoot black holes (circles)