用Label创建了一个MenuItemLabel以后，当我为Label加上阴影和光晕以后，按钮的位置就偏移了，要点左下角才有反应，这是为什么？是BUG吗？下面附上代码。
auto menu1 = Menu::create();
addChild(menu1);
menu1->setPosition(Vec2(300, 450));
auto label1 = Label::createWithTTF("Play", "fonts/Marker Felt.ttf", 100);
label1->enableGlow(Color4B(255, 255, 0, 255));
label1->enableShadow();
auto menuItem1 = MenuItemLabel::create(label1, CC_CALLBACK_1(HelloWorld::backgroundMusic, this));
auto label2 = Label::createWithTTF("HIT", "fonts/Marker Felt.ttf", 100);
label2->enableGlow(Color4B(255, 255, 0, 255));
label2->enableShadow();
auto menuItem2 = MenuItemLabel::create(label2, CC_CALLBACK_1(HelloWorld::effectMusic, this));
menu1->addChild(menuItem1);
menu1->addChild(menuItem2);
//menu1->alignItemsVertically();
menu1->alignItemsVerticallyWithPadding(100);