README.md

scalartemis

At first I just wanted to rewrite the Artemis framework to Scala, but I discovered that the architecture of the Artemis framework doesn't meet my expectations. So Artemis gave me the overall view what should it look like. Almost everything else is entirely new.

Documentation

http://scalartemis.readthedocs.io/en/latest/

Usage SBT 0.13.6+

In SBT 0.13.6+ you only need to add my Bintray repository

 resolvers += Resolver.bintrayRepo("moriturius", "maven")

and add the dependency

 libraryDependencies += "io.github.marad" %% "scalartemis" % "1.0.0"

Example

case class Position(var x: Int, var y: Int) extends Component

class PositionUpdateSystem(val world: World)
      extends SequentialProcessingSystem(Aspect.forAll[Position])
      with ComponentMapping {
  override def process(entity: Entity, delta: Float): Unit = {
    component[Position](entity) match {
      case Some(position) =>
        position.x += 1
        position.y += 1
      case None =>
    }
  }
}

val world = new World
world.registerSystem(new PositionUpdateSystem(world))
world.createEntity(Position(1, 2))
world.update(1f)

In the example above there is one component Position which holds the coordinates. There is also PositionUpdateSystem that contains the logic - what should happen each world update to every entity with Position component. Here we declare our system as subclass of SequentialProcessingSystem which means that all entities are processed one by one.

Also please note that SequentialProcessingSystem has constructor argument of type Aspect. This argument is then used to determine which entities are handled by the system - it will receive only entities matching requirements (containing required components).

We can also see that the ComponentMapping trait is used. This allows us to call method component[T <: Component](entity: Entity) which returns Option[T]. This method is used to fetch component of given type for given entity.

Below the PositionUpdateSystem class declaration we create the World object and register our system in it. Then we create one entity with one component Position(1, 2). In the end there is one call world.update(1f) which asks the world to process all systems.