基于visual c++.net开发交互式cad系统（具体为划线，画圆，画多边形）-Based on visual c++. Net development of interactive cad system (specifically for the dash, circle, polygon drawing)

有别过去传统的画线画园画多边形的算法，以步骤实现画图。-Traditional line drawing drawing a circle polygon drawing algorithm is different from the past, drawing step.