silphius/app/ecs/systems/control-direction.js

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

export default class ControlDirection extends System {

  tick() {
    for (const {Controlled, Direction} of this.ecs.changed(['Controlled'])) {
      const {locked, moveUp, moveRight, moveDown, moveLeft} = Controlled;
      if (locked) {
        continue;
      }
      if (
        0 === moveRight
        && 0 === moveDown
        && 0 === moveLeft
        && 0 === moveUp
      ) {
        continue;
      }
      Direction.direction = (
        TAU + Math.atan2(
          moveDown - moveUp,
          moveRight - moveLeft,
        )
      ) % TAU;
    }
  }

}