@javelin/ecs

@javelin/ecs

A TypeScript Entity-Component System (ECS) for Node and web browsers.

Docs

Visit https://javelin.games for documentation, examples, and external resources.

Features

Fast

Entities are organized by their component makeup into Archetypes for quick lookups and iteration. In a small app (10 component types, 10 archetypes, 10 queries), Javelin can iterate ~2.5 million entities per 16ms on a 2GHz Intel i5 processor.

Ergonomic

Define your game's data model using simple syntax.

const Transform = {
  x: float64,
  y: float64,
}
const Inventory = {
  bags: arrayOf(arrayOf(uint32)),
}
const world = createWorld()
const entity = world.spawn(
  component(Transform), // => { x: 0, y: 0 }
  component(Inventory), // => { bags: [] }
)

Intuitive

Query game state using simple syntax.

const qryBodies = createQuery(Transform, Velocity)
const sysPhysics = () =>
  qryBodies((e, [t, v]) => {
    t.x += v.x
    t.y += v.y
  })

Powerful

Best practices are built-in with tools like Topics for inter-system messaging:

const sysMovement = () =>
  qryInput((e, [input]) => {
    if (input.jump) {
      topPhysics.push(impulse(e, 0, 10))
    }
  })
const sysPhysics = () => {
  for (const message of topPhysics) {
    // ...
  }
}

and Effects for handling async code, third-party dependencies, and events:

const sysRender = () => {
  const scene = useScene()
  const model = useLoadGLTF("llama.gltf")

  useMonitor(
    qryPlayers,
    e => scene.insert(e, model, world.get(e, Transform)),
    e => scene.destroy(e),
  )
}