用 Dart 编写的简单快速的实体-组件-系统 (ECS) 库

void update(double deltaTime, SetEntity entities) {
    for (var i = 0; i < entities.size; i++) {
      Entity entity = entities[i];
      TransformComponent transform = transformComponents[entity] as TransformComponent;
      VelocityComponent rotation = velocityComponents[entity] as VelocityComponent;
      transform.rotation += rotation.velocity * deltaTime;
      transform.dirty = true;
    }
  }

void updateSprite(TransformComponent transform, SpriteComponent sprite) {
    var textureRegion = sprite.textureRegion;
    if (transform.dirty && textureRegion != null) {
      var scos = cos(transform.rotation) * transform.scale;
      var ssin = sin(transform.rotation) * transform.scale;
      var tx = -scos * textureRegion.anchorX + ssin * textureRegion.anchorY;
      var ty = -ssin * textureRegion.anchorX - scos * textureRegion.anchorY;
      sprite.transformData.set(scos, ssin, tx, ty);
      transform.dirty = false;
    }
  }