实验内容：

1 实现扫描转换多边形的算法填充多边形。

实现内容：

1，　　可以画任意多边形。

2，　　三角形也是通过扫描转换多边形的算法实现。

具体实现：

画多边形用moveto(),lineto(),两个函数实现画没一条边。

构造ET表，AEL表，通过这两个表填充多边形。

画图步骤：

1.　　取顶点：用n记录顶点个数，按下鼠标开始取点，第二次按下取得第二个顶点，第i次按下取得第i 个顶点。取得的顶点放到Verex[]中。

2.　　画多边形：按下菜单按钮----多边形。画多边形时可通过颜色菜单选择填充颜色。

3.　　填充多边形：按下菜单按钮----填充。填充时可通过颜色菜单选择填充颜色。

4.　　重新画一个多边形时需要先点菜单---new，然后再重复1，2，3步。

-experiment : to achieve a polygon scan conversion algorithm filled polygons. Implementation : a can draw arbitrary polygon. 2, as well as through the triangular polygon scan conversion algorithm. Realization : painting polygon with moveto (), LineTo (), two paintings did not function to achieve an edge. Construction ET table, Table AEL, through these two tables filled polygons. Drawing steps : 1. Vertex admitted : n vertices record number, press the mouse started to admit, the second press made the second vertices, i pressed the first time i made its vertex. The vertex put Verex []. 2. Painting polygon : press the menu button-polygon. When painting polygon can be filled with color menu to choose colors. 3. Polygon Filling : press the menu button-filled. When filled with color by color fill