简单屏幕烟花程序

可惜一开始没能画成圆,所以整个过程都是菱形的变换,希望大家多多指教,能够想办法把初始状态就围成一个圆.

-Unfortunately, a simple screen fireworks begin the program could not draw a circle, so the whole process is the diamond transformation, we hope the exhibitions can think of ways to the initial state is surrounded by a circle.