import {
createWorld,
Types,
defineComponent,
defineQuery,
addEntity,
addComponent,
pipe,
} from 'bitecs'
const Vector3 = { x: Types.f32, y: Types.f32, z: Types.f32 }
const Position = defineComponent(Vector3)
const Velocity = defineComponent(Vector3)
const movementQuery = defineQuery([Position, Velocity])
const movementSystem = (world) => {
const { time: { delta } } = world
const ents = movementQuery(world)
for (let i = 0; i < ents.length; i++) {
const eid = ents[i]
Position.x[eid] += Velocity.x[eid] * delta
Position.y[eid] += Velocity.y[eid] * delta
Position.z[eid] += Velocity.z[eid] * delta
}
return world
}
const timeSystem = world => {
const { time } = world
const now = performance.now()
const delta = now - time.then
time.delta = delta
time.elapsed += delta
time.then = now
return world
}
const pipeline = pipe(movementSystem, timeSystem)
const world = createWorld()
world.time = { delta: 0, elapsed: 0, then: performance.now() }
const eid = addEntity(world)
addComponent(world, Position, eid)
addComponent(world, Velocity, eid)
Velocity.x[eid] = 1.23
Velocity.y[eid] = 1.23
setInterval(() => {
pipeline(world)
}, 16)