javelin API

javelin-api.ts

import {
  changed,
  createComponent,
  createApp,
  createQuery,
  createType,
  Group,
  Format,
  createSchema,
  useConst,
  useQuery,
} from "../src"

enum Id {
  Position,
  Velocity,
  Rotation,
}

interface Vector2 {
  x: number
  y: number
}
interface Position extends Vector2 {}
interface Velocity extends Vector2 {}
interface Rotation {
  angle: number
}

let Vector2 = {x: Format.f32, y: Format.f32}

let Position = createComponent(Id.Position, createSchema<Position>(Vector2))
let Velocity = createComponent(Id.Velocity, createSchema<Velocity>(Vector2))
let Rotation = createComponent(Id.Rotation, createSchema<Rotation>({angle: Format.f32}))

let Point = createType(Position)
let Kinetic = createType(Point, Velocity)
let Transform = createType(Kinetic, Rotation)

createApp()
  .addStartupSystem(world => {
    world.createEntity(Point, {x: 0, y: 0})
    world.createEntity(Kinetic, {x: 0, y: 0}, {x: 0, y: 0})
    world.createEntity(Transform, {x: 0, y: 0}, {x: 0, y: 0}, {angle: 0})
  })
  .addSystemToGroup(Group.First, () => {
    console.log("step")
  })
  .addSystem(() => {
    let kinetics = use_const(() =>
      createQuery()
        .with(Position)
        .withOptional(Velocity)
        .without(Rotation)
        .as(changed(Position), Velocity),
    )
    useQuery(kinetics).forEach((entity, position, velocity) => {
      if (position) {
        console.log(
          `${entity} changed position${velocity ? ` velocity: ${velocity}` : ""}`,
        )
      }
    })
  })
  .step()