用迭代算法实现动态逼近效果，最终实现颤动的小水珠，代码很简单，但是很有意思，只要修改一下，就可以制作出很漂亮的按钮-using iterative approximation algorithm dynamic effects, and eventually realizing the quiver of small globs, the code is very simple. However, it is very interesting, as long as the changes that can produce a very nice button