验证直线和圆生成的DDA算法和Bresenham算法。能通过类分别抽象直线和圆，并对各自的DDA算法及Bresenham算法生成图元功能进行封装，通过设计MFC单文档应用程序来验证算法的正确性。-DDA Algorithm Bresenham algorithm verification and generation lines and circles. By abstract lines and circles class respectively, and the respective DD