I'm trying to use boost::geometry and boost::units together.
For some reason boost::geometry doesn't represent the difference of two
points as vectors.
So, I'm making my own Vector class and defining Vector = Point - Point.
The sample program below doesn't compile because I need to tell the units
library about the special properties of point subtraction (I think).
terry
#include
#include
#include
#include
#include <iostream>
#include <iomanip>
using namespace std;
using namespace boost;
using namespace boost::geometry;
using namespace boost::units;
typedef point Point;
class Vector {
Point _impl;
friend Vector operator-(const Point& lhs, const Point& rhs);
explicit Vector(Point p) : _impl(p) { }
public:
Vector() : _impl(0) { }
Vector(double dx, double dy, double dz=0) : _impl(dx, dy, dz) { }
friend ostream& operator<<(ostream& os, const Vector& v)
{ return os << dsv(v._impl); }
}; // Vector
inline
Vector operator-(const Point& lhs, const Point& rhs) {
Point tmp(lhs);
subtract_point(tmp, rhs);
return Vector(tmp);
}
inline
ostream& operator<<(ostream& os, const Point& pt)
{ return os << dsv(pt); }
int main() {
Point p1(1, 2, 3);
Point p2(4, 5, 6);
typedef quantity Position;
typedef quantity Displacement;
Position start( p1 * si::meters);
Position finish(p2 * si::meters);
Displacement disp(finish - start);
cout << "disp=" << disp << endl;
return EXIT_SUCCESS;
} // main
