silphius/app/ecs/systems/run-animations.js

import {System} from '@/ecs/index.js';

export default class RunAnimations extends System {

  static queries() {
    return {
      default: ['Sprite'],
    };
  }

  tick(elapsed) {
    for (const {Sprite} of this.select('default')) {
      if (0 === Sprite.speed || !Sprite.isAnimating) {
        continue;
      }
      Sprite.elapsed += elapsed / Sprite.speed;
      while (Sprite.elapsed > 1) {
        Sprite.elapsed -= 1;
        Sprite.frame += 1;
      }
    }
  }

}