现在的计算机能够生成各种复杂的图形，但无论其多么复杂，它都是由一些基本图形组合而成的。因此，学习基本图形的生成算法是掌握计算机图形的基础。-Now the computer can generate a variety of complex graphics, but no matter how complex, it is a combination of some of the basic graphics made. Thus, learning basic graphics genera