初步介绍分形编程，示例中显示了4种分形图案，递归算法简单易懂。-Introduction to fractal programming, the example shows four kinds of fractal patterns, recursion is easy to understand.

Breshman画直线、画圆、简单种子填充、递归种子填充-Breshman draw a line to draw circles simple seed filling ，recursion seed filling，Breshman draw a line ，draw circles

通过递归法实现基于正十二面体的线框球，能够操作键盘和鼠标实现球体的放大、缩小和旋转-By recursion method based on frame ball dodecahedron, and able to operate a keyboard and mouse balls zoom and rotation