SpaceShooterScore

The listener the kill event was missing. SpaceShooterHealth.destroyShip fires wingman.enemy.killed on every hostile death; this is the other end — it turns each kill into points and rebroadcasts the running total for a scoreboard to render.

What it does

SpaceShooterScoreComponent is two numbers: score (the run's accumulated points, starts at 0) and pointsPerKill (the payout, defaults to 100). One lives on the world/director entity — a per-run singleton, not a per-ship counter.

SpaceShooterScoreSystem does no per-frame work. On initialize it subscribes to the one event that matters:

protected onInitialize(): void {
  // The void gets a listener: every enemy death is now worth points.
  this.listen(SpaceShooterHealthEvents.ENEMY_KILLED, () => this.awardKill());
}

Each kill adds the payout to the total and rebroadcasts it as the canonical score.changed:

private awardKill(): void {
  const comp = this.getPrimary();
  if (!comp) return;
  const delta = comp.pointsPerKill;
  comp.score += delta;
  this.eventBus.emit(ScoreEvents.CHANGED, {
    score: comp.score,
    delta,
  });
}

getPrimary returns the first entity carrying the component — the singleton. A scoreboard HUD listening for score.changed updates with no wiring back to this System.

Use it in a scene

Key one SpaceShooterScoreComponent onto the world/director entity, and pull in a scoreboard that renders score.changed. Raise pointsPerKill to make a mission's kills worth more:

"Director": {
  "components": {
    "SpaceShooterScore": { "pointsPerKill": 250 }
  }
}

The kills come from SpaceShooterHealth — any hostile ship that dies through destroyShip feeds this. Without that death path in the scene there is nothing to count.

Events

• Emits score.changed (ScoreEvents.CHANGED) after every counted kill — { score, delta }. score is the new total, delta the points that kill was worth.
• Listens for wingman.enemy.killed (SpaceShooterHealthEvents.ENEMY_KILLED) — the hostile-death signal. Nothing else moves the score.

Dependencies

• SpaceShooterHealth — owns destroyShip, which emits the wingman.enemy.killed this counts. Its only input.

Notes

• Kills, not goals. This is the kill-scored variant, named apart from the generic arcade Score (which listens for score.add / goal.scored). Both emit the same score.changed, so a scoreboard swaps between them without rewiring.
• Only enemy deaths count. It subscribes to ENEMY_KILLED alone — a downed freighter or a lost cargo car (wingman.freighter.killed / wingman.freighter.car.lost) fires its own event and scores nothing here. Add another listener if a mission should pay for those.
• The event names live in the shared arcade dictionary, not this file — SpaceShooterHealthEvents (in) and ScoreEvents (out) both come from @babylonjsmarket/arcade, so the emitter and this listener never import each other.
• First match wins. getPrimary returns the first entity with the component; a second SpaceShooterScoreComponent in the same scene is ignored. Keep it a singleton.