visibles<T extends GameComponent> method

Implementation

@override
Iterable<T> visibles<T extends GameComponent>() {
  final cached = _visibleComponentsCache[T];
  final cachedFrame = _visibleComponentsCacheFrame[T];
  if (cached != null && cachedFrame == _frameCounter) {
    return cached.cast<T>();
  }

  // Rebuild cache for this type for the current frame.
  final rebuilt = world.children
      .whereType<T>()
      .where((e) => e.isVisible)
      .toList(growable: false);
  _visibleComponentsCache[T] = rebuilt.cast<GameComponent>();
  _visibleComponentsCacheFrame[T] = _frameCounter;
  return rebuilt;
}