point.h

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#ifndef SEEN_Geom_POINT_H
#define SEEN_Geom_POINT_H

#include <iostream>

#include "coord.h"
#include "utils.h"

namespace Geom {

enum Dim2 { X=0, Y=1 };

class Matrix;

class Point {
    Coord _pt[2];

  public:
    inline Point()
    { _pt[X] = _pt[Y] = 0; }

    inline Point(Coord x, Coord y) {
        _pt[X] = x; _pt[Y] = y;
    }

    inline Point(Point const &p) {
        for (unsigned i = 0; i < 2; ++i)
            _pt[i] = p._pt[i];
    }

    inline Point &operator=(Point const &p) {
        for (unsigned i = 0; i < 2; ++i)
            _pt[i] = p._pt[i];
        return *this;
    }

    inline Coord operator[](unsigned i) const { return _pt[i]; }
    inline Coord &operator[](unsigned i) { return _pt[i]; }

    Coord operator[](Dim2 d) const throw() { return _pt[d]; }
    Coord &operator[](Dim2 d) throw() { return _pt[d]; }

    static inline Point polar(Coord angle, Coord radius) {
        return Point(radius * std::cos(angle), radius * std::sin(angle));
    }

    inline Coord length() const { return hypot(_pt[0], _pt[1]); }

    Point ccw() const {
        return Point(_pt[Y], -_pt[X]);
    }

    Point cw() const {
        return Point(-_pt[Y], _pt[X]);
    }

    inline void round (int places = 0) {
        _pt[X] = (Coord)(decimal_round((double)_pt[X], places));
        _pt[Y] = (Coord)(decimal_round((double)_pt[Y], places));
        return;
    }

    void normalize();

    inline Point operator+(Point const &o) const {
        return Point(_pt[X] + o._pt[X], _pt[Y] + o._pt[Y]);
    }
    inline Point operator-(Point const &o) const {
        return Point(_pt[X] - o._pt[X], _pt[Y] - o._pt[Y]);
    }
    inline Point &operator+=(Point const &o) {
        for ( unsigned i = 0 ; i < 2 ; ++i ) {
            _pt[i] += o._pt[i];
        }
        return *this;
    }  
    inline Point &operator-=(Point const &o) {
        for ( unsigned i = 0 ; i < 2 ; ++i ) {
            _pt[i] -= o._pt[i];
        }
        return *this;
    }

    inline Point operator-() const {
        return Point(-_pt[X], -_pt[Y]);
    }
    inline Point operator*(double const s) const {
        return Point(_pt[X] * s, _pt[Y] * s);
    }
    inline Point operator/(double const s) const {
        //TODO: s == 0?
        return Point(_pt[X] / s, _pt[Y] / s);
    }
    inline Point &operator*=(double const s) {
        for ( unsigned i = 0 ; i < 2 ; ++i ) _pt[i] *= s;
        return *this;
    }
    inline Point &operator/=(double const s) {
        //TODO: s == 0?
        for ( unsigned i = 0 ; i < 2 ; ++i ) _pt[i] /= s;
        return *this;
    }

    Point &operator*=(Matrix const &m);

    inline int operator == (const Point &in_pnt) {
        return ((_pt[X] == in_pnt[X]) && (_pt[Y] == in_pnt[Y]));
    }

    friend inline std::ostream &operator<< (std::ostream &out_file, const Geom::Point &in_pnt);
};

inline Point operator*(double const s, Point const &p) { return p * s; }

inline std::ostream &operator<< (std::ostream &out_file, const Geom::Point &in_pnt) {
    out_file << "X: " << in_pnt[X] << "  Y: " << in_pnt[Y];
    return out_file;
}

inline Point operator^(Point const &a, Point const &b) {
    Point const ret(a[0] * b[0] - a[1] * b[1],
                    a[1] * b[0] + a[0] * b[1]);
    return ret;
}

//IMPL: boost::EqualityComparableConcept
inline bool operator==(Point const &a, Point const &b) {
    return (a[X] == b[X]) && (a[Y] == b[Y]);
}
inline bool operator!=(Point const &a, Point const &b) {
    return (a[X] != b[X]) || (a[Y] != b[Y]);
}

inline bool operator<=(Point const &a, Point const &b) {
    return ( ( a[Y] < b[Y] ) ||
             (( a[Y] == b[Y] ) && ( a[X] < b[X] )));
}

Coord L1(Point const &p);

inline Coord L2(Point const &p) { return p.length(); }

inline Coord L2sq(Point const &p) { return p[0]*p[0] + p[1]*p[1]; }

double LInfty(Point const &p);
bool is_zero(Point const &p);
bool is_unit_vector(Point const &p);

extern double atan2(Point const p);
extern double angle_between(Point const a, Point const b);

//IMPL: NearConcept
inline bool are_near(Point const &a, Point const &b, double const eps=EPSILON) {
    return ( are_near(a[X],b[X],eps) && are_near(a[Y],b[Y],eps) );
}

inline Point rot90(Point const &p) { return Point(-p[Y], p[X]); }

inline Point lerp(double const t, Point const a, Point const b) { return (a * (1 - t) + b * t); }

Point unit_vector(Point const &a);

inline Coord dot(Point const &a, Point const &b) { return a[0] * b[0] + a[1] * b[1]; }
inline Coord cross(Point const &a, Point const &b) { return dot(a, b.cw()); }

inline Coord distance (Point const &a, Point const &b) { return L2(a - b); }

inline Coord distanceSq (Point const &a, Point const &b) { return L2sq(a - b); }

Point abs(Point const &b);

Point operator*(Point const &v, Matrix const &m);

Point operator/(Point const &p, Matrix const &m);

} /* namespace Geom */

#endif /* !SEEN_Geom_POINT_H */

/*
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  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
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  End:
*/
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