If this line is parallel to Line L, then return null.
Returns a vertical cross point with P. 求点P到直线的垂直交点。
Returns a cross point of this line and Ray(p, rad). 直线与射线的交点。
If the cross point is not exist, then return null.
斜率
Returns the square of the distance from a point to a line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by the specified coordinates. If the specified point intersects the line, this method returns 0.0.
a value that is the square of the distance from the specified point to the specified line.
Returns the distance from a point to a line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by the specified coordinates. If the specified point intersects the line, this method returns 0.0.
a value that is the distance from the specified point to the specified line.
P1,P2,P3 is collinear. 三点是否共线
Returns the relation position of Line1(p1,p2) and Line2(p3,p4). 直线1与直线2的位置关系。
-1 is Parallel and Non-Collinear; 0 is Collinear; 1 is Cross and Non-Vertical; 2 is Cross and Vertical.
Caculate the slope of Segment P1P2. 计算线段(p1,p2)的斜率。当线段与X轴垂直时，斜率不存在
when P1P2 is vertical to the X, then return null.
Returns a cross point of Line L. 求与直线的交点。