AbsAnimation()=default
默认构造函数
AbsAnimation & operator=(const AbsAnimation &)=default
AbsAnimation & operator=(AbsAnimation &&)=delete
AbsAnimation(AbsAnimation &&)=delete
AbsAnimation(const AbsAnimation &)=default
virtual ~AbsAnimation()=default
虚析构函数
virtual void update_to(float_t time)=0
更新到指定时间点