+
- point getcrosspoint(point a,point a1,point b,point b1)
- {
- point base=b1-b;
- double d1=abs(cross(base,a-b));
- double d2=abs(cross(base,a1-b));
- double t=d1/(d1+d2);
- point temp=(a1-a)*t;
- return a+temp;
- }
线段与线段的交点
原文：https://www.cnblogs.com/honghong87/p/9127611.html
