C++点到直线的距离和垂足

#include<iostream>
#include<math.h>
using namespace std;

typedef struct POINT{ 
	double x;
	double y;
}POINT;

typedef struct Line{ 
	POINT  startPoint;
	POINT  endPoint;
}Line;

//求点到直线的距离 和 垂足
double getDistanceP2L(POINT point ,Line line,POINT &p_point)
{
	double x1=line.startPoint.x;
	double y1=line.startPoint.y;
	double x2=line.endPoint.x;
	double y2=line.endPoint.y;
	double x0=point.x;
	double y0=point.y;

	double k=x1==x2?100000:(y2-y1)/(x2-x1);//当x1=x2时，给斜率设一个较大值100000
	double a=k;
	double b=-1;
	double c=y1-k*x1;
	//垂足
	double px = (b*b*x0-a*b*y0-a*c)/(a*a+b*b);
	double py = (a*a*y0-a*b*x0-b*c)/(a*a+b*b); 
	p_point.x = px;
	p_point.y = py;

	cout<<"垂足："<<p_point.x<<"   ,   "<<p_point.y<<endl;

	double d=abs(a*x0+b*y0+c)/sqrt(a*a+b*b);
	cout<<"距离："<<d<<endl;
	return d;
}


int main()
{
	POINT point;
	POINT t_point;
	point.x =1;
	point.y = 1;
	Line line;
	line.startPoint.x = 0;
	line.startPoint.y = 0;
	line.endPoint.x = 0;
	line.endPoint.y = 1;

	getDistanceP2L(point , line , t_point);
	return 0;
}