C++：三维空间，点，线，面之间的距离

##C++：三维空间，点，线，面之间的距离
main函数中仅写了点到点，点到线，点到面，

#include
#include
using namespace std;
class Point{
public:
 Point(double x=0.0,double y=0.0,double z=0.0);
 void disp();
 friend class ComputeTools;
private:
 double x,y,z;
}; 
Point::Point(double x,double y,double z)
{
 this->x=x;
 this->y=y;
 this->z=z;
}
void Point::disp()
{
 cout<<"point:("<<x<<","<<y<<","<<z<<")  ";
}
class Line
{
 private:
  double a,b,c,d;//ax+by+cz+d=0
 public:
  Line(double a=0.0,double b=0.0,double c=0.0,double d=0.0);
  void disp(); 
  friend class ComputeTools;
};
Line::Line(double a,double b,double c,double d)
{this->a=a; this->b=b; this->c=c; this->d;}
void Line::disp()
{cout<<"line:"<<a<<"x+"<<b<<"y+"<<c<<"z"<<"="<<d<<"  ";}
class Surface{
 private:
  double a,b,c,d;
 public:
  Surface(double a=0.0,double b=0.0,
    double c=0.0,double d=0.0);
  void disp();
  friend class ComputeTools;
};
Surface::Surface(double a,double b,double c,double d)
{this->a=a; this->b=b; this->c=c; this->d=d;}
void Surface::disp()
{cout<<a<<"x+"<<b<<"y+"<<c<<"z+"<<d<<"=0   ";}
class ComputeTools{
 public:
  static double distance(Point p1,Point p2);
  static double distance(Point p1,Line l1);
  static double distance(Point p1,Surface s1);
  static double distance(Line l1,Line l2);
  static double distance(Line l1,Surface s1);
  static double distance(Surface s1,Surface s2);
};
double ComputeTools::distance(Point p1,Point p2)
{
 return sqrt((p1.x-p2.x)*(p1.x-p2.x)
 +(p1.y-p2.y)*(p1.y-p2.y)+(p1.z-p2.z)*(p1.z-p2.z));
}
double ComputeTools::distance(Point p1,Line l1)
{
 return fabs(l1.a*p1.x+l1.b*p1.y+l1.c*p1.z)/sqrt(l1.a*l1.a+l1.b*l1.b+l1.c*l1.c);
}
double ComputeTools::distance(Point p1,Surface s1)
{
 return fabs(s1.a*p1.x+s1.b*p1.y+s1.c*p1.z+s1.d)/
    sqrt(s1.a*s1.a+s1.b*s1.b+s1.c*s1.c);
}
double ComputeTools::distance(Line l1,Line l2)
{
 return fabs(l1.c-l2.c)/sqrt(l1.a*l1.a+l1.b*l1.b+);
}
int main()
{
 Point p1(1.0,1.0,1.0),p2(0.0,0.0,0.0);
 Line l1(1.0,1.0,1.0),l2(2.0,2.0,2.0);
 Surface s1(0.0,0.0,1.0);
 p1.disp();   p2.disp();
 cout<<"  Distance: "<<ComputeTools::distance(p1,p2)<<endl;
 p1.disp(); l1.disp();
 cout<<"  Distance: "<<ComputeTools::distance(p1,l1)<<endl;
 p1.disp(); s1.disp();
 cout<<"  Distance: "<<ComputeTools::distance(p1,s1)<<endl;
 l1.disp(); l2.disp();
 cout<<"  Distance: "<<ComputeTools::distance(l1,l2)<<endl;
}