基于活性边表的多边形扫描线算法，MFC GPI 可含内环，可自定义多边形！-Based on the activity side of the table scan line algorithm for polygon, MFC GPI can contain inner ring can be custom polygon!

实现了基本的DDA直线、中点直线、Bresenham直线算法，实现中点画圆，能画多边形，能进行递归种子，扫面直线填充，能改变颜色和画笔大小。-DDA to achieve the basic line, the midpoint of a straight line, Bresenham linear algorithm, the midpoint of the circle, to draw a polygon, the seeds can be recursive, linear sweep