#ifndef SEEN_LINE_GEOMETRY_H

#define SEEN_LINE_GEOMETRY_H

#include <2geom/point.h>

#include <boost/optional.hpp>

#include "axis-manip.h" // FIXME: This is only for Box3D::epsilon; move that to a better location

#include "persp3d.h"

class SPDesktop;

typedef unsigned int guint32;

namespace Box3D {

class Line {

public:

Line(Geom::Point const &start, Geom::Point const &vec, bool is_endpoint = true);

Line(Line const &line);

virtual ~Line() {}

Line &operator=(Line const &line);

virtual boost::optional<Geom::Point> intersect(Line const &line);

inline Geom::Point direction () { return v_dir; }

Geom::Point closest_to(Geom::Point const &pt); // returns the point on the line closest to pt

friend inline std::ostream &operator<< (std::ostream &out_file, const Line &in_line);

boost::optional<Geom::Point> intersection_with_viewbox (SPDesktop *desktop);

inline bool lie_on_same_side (Geom::Point const &A, Geom::Point const &B) {

/* If A is a point in the plane and n is the normal vector of the line then

return ((Geom::dot(A, normal) - d0) * (Geom::dot(B, normal) - d0)) > 0;

}

double lambda (Geom::Point const pt);

inline Geom::Point point_from_lambda (double const lambda) {

return (pt + lambda * Geom::unit_vector (v_dir)); }

protected:

void set_direction(Geom::Point const &dir);

inline static bool pts_coincide (Geom::Point const pt1, Geom::Point const pt2)

{

return (Geom::L2 (pt2 - pt1) < epsilon);

}

Geom::Point pt;

Geom::Point v_dir;

Geom::Point normal;

Geom::Coord d0;

};

inline double determinant (Geom::Point const &a, Geom::Point const &b)

{

return (a[Geom::X] * b[Geom::Y] - a[Geom::Y] * b[Geom::X]);

}

std::pair<double, double> coordinates (Geom::Point const &v1, Geom::Point const &v2, Geom::Point const &w);

bool lies_in_sector (Geom::Point const &v1, Geom::Point const &v2, Geom::Point const &w);

bool lies_in_quadrangle (Geom::Point const &A, Geom::Point const &B, Geom::Point const &C, Geom::Point const &D, Geom::Point const &pt);

std::pair<Geom::Point, Geom::Point> side_of_intersection (Geom::Point const &A, Geom::Point const &B,

Geom::Point const &C, Geom::Point const &D,

Geom::Point const &pt, Geom::Point const &dir);

void create_canvas_point(Geom::Point const &pos, double size = 4.0, guint32 rgba = 0xff00007f);

void create_canvas_line(Geom::Point const &p1, Geom::Point const &p2, guint32 rgba = 0xff00007f);

inline std::ostream &operator<< (std::ostream &out_file, const Line &in_line) {

out_file << "Start: " << in_line.pt << " Direction: " << in_line.v_dir;

return out_file;

}

} // namespace Box3D

#endif /* !SEEN_LINE_GEOMETRY_H */