rLine2D.cpp

//#include <iostream.h>
#include "rPoint2D.h"
#include "rLine2D.h"
#include <ostream>
#include <iostream>
rLine2D::rLine2D (double slope,double intercept)
{
  m = slope;
  b = intercept;
}
rLine2D::rLine2D (rPoint2D p0,rPoint2D p1)
{
  m = (p1.y-p0.y)/(p1.x-p0.x);
  b = p0.y - m*p0.x;
}
rLine2D::rLine2D (double x0,double y0,double x1, double y1)
{
  m = (y1-y0)/(x1-x0);
  b = y0 - m*x0;
}
rLine2D& rLine2D::operator=(rLine2D p)
{
  m = p.m; 
  b = p.b;
  return (*this);
}
int rLine2D::operator==(rLine2D p)
{
  if (m == p.m && b == p.b )
    return (1);
  else 
    return (0);
}
std::ostream& operator<<(std::ostream& os, rLine2D& p)
{
  os << "[y = "<< p.m <<"*x + "<<p.b<<']';
  return os;
}
 
void rLine2D::set(rPoint2D p0, rPoint2D p1)
{
  m = (p1.y-p0.y)/(p1.x-p0.x);
  b = p0.y - m*p0.x;
}
double rLine2D::y(double x) 
{
  return m*x + b;
}
double rLine2D::x(double y) 
{
  return (y-b)/m;
}
int rLine2D::sameside (rPoint2D p,rPoint2D q) 
{
  double result1=m*p.x+b;
  double result2=m*q.x+b;
  
  return  
    (p.y <= result1) == (q.y <= result2) ||
    (p.y >= result1) == (q.y >= result2) ;
}