Systems

Systems are just plain functions that can specify dependencies to be injected at runtime. Dependencies can either be Queries or Resources.

There are 2 types of Systems, System and SystemOnce, and you may use the return type of the function to declare which type it is.

import type { System, SystemOnce } from '@vaguevoid/fiasco'

function animalsInit(): SystemOnce {
  // runs only once
}

function animalsMove(): System {
  // runs every frame
}

// Magic export - must be named `systems`
export const systems = [animalsInit, animalsMove]

IMPORTANT

Be sure to export your systems using the magic export systems from the root of the game - the order of the array matters, systems run in that order.

INFO

The return type for systems is optional and defaults to System, so only SystemOnce systems really need to specify the return type. But it's up to you.

System arguments must only be Queries or Resources:

function mySystem(query: Query<[...]>, frame: FrameConstants, aspect: Aspect) {
  // update items
}

Systems can be enabled or disabled with setSystemEnabled. A disabled system will no longer run every frame until re-enabled.

function system1() {
  // disable system2
  engine.setSystemEnabled("system2", false)
}

Systems ​

Systems