扩展后的中点法画直线程序,可以支持任意斜率的直线的绘制,-Extended point method to draw a straight line in the program, can support any of the slope of the straight line drawing,

判断两条线段的相关算法，相交、求一点到线段的距离、求线段的交点、求线段的斜率。(Judge the two line segment correlation algorithm, intersection, seek a point to the line distance, the intersection of the line segment, the slope of the line segment)

这是一个作图的界面程序可以在任一座标以任一斜率()