geometry/product.hpp

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• Last update: 2023-07-08 14:12:19+09:00
• Include: #include "geometry/product.hpp"

Depends on

• geometry/base.hpp
• geometry/point.hpp

Required by

• geometry/projection.hpp

Code

#pragma once

#include "./base.hpp"
#include "./point.hpp"

namespace matumoto {
  Real cross(const Point &a, const Point &b) {
    return a.real() * b.imag() - a.imag() * b.real();
  }

  Real dot(const Point &a, const Point &b) {
    return a.real() * b.real() + a.imag() * b.imag();
  }
} // namespace matumoto

#line 2 "geometry/product.hpp"

#line 2 "geometry/base.hpp"

#include <cmath>

namespace matumoto {
  using namespace std;
  using Real = double;

  constexpr Real PI = M_PI;
  constexpr Real EPS = 1e-9;

  inline int sign(Real a) {
    if (a < -EPS)
      return -1;
    if (a > +EPS)
      return +1;
    return 0;
  }

  inline bool equals(Real a, Real b) {
    return sign(a - b) == 0;
  }
} // namespace matumoto
#line 2 "geometry/point.hpp"

#line 4 "geometry/point.hpp"

#include <complex>

namespace matumoto {
  using Point = complex<Real>;

  istream &operator>>(istream &is, Point &p) {
    Real x, y;
    is >> x >> y;
    p = Point(x, y);
    return is;
  }

  ostream &operator<<(ostream &os, const Point &p) {
    os << p.real() << " " << p.imag();
    return os;
  }

  Point operator*(const Point &p, const Real &k) {
    return Point(p.real() * k, p.imag() * k);
  }

  Point rotate_cw(const Real &radian, Point p, const Point &origin = Point(0, 0)) {
    p -= origin;
    Real r = cosl(radian) * p.real() + sinl(-radian) * p.imag();
    Real i = sinl(radian) * p.real() + cosl(-radian) * p.imag();
    p = Point(r, i);
    p += origin;
    return p;
  }

  Point rotate_ccw(const Real &radian, Point p, const Point &origin = Point(0, 0)) {
    p -= origin;
    Real r = cosl(radian) * p.real() + sinl(-radian) * p.real();
    Real i = sinl(radian) * p.imag() + cosl(-radian) * p.imag();
    p = Point(r, i);
    p += origin;
    return p;
  }

  bool equals(const Point &a, const Point &b) {
    return equals(a.real(), b.real()) and equals(a.imag(), b.imag());
  }
} // namespace matumoto
#line 5 "geometry/product.hpp"

namespace matumoto {
  Real cross(const Point &a, const Point &b) {
    return a.real() * b.imag() - a.imag() * b.real();
  }

  Real dot(const Point &a, const Point &b) {
    return a.real() * b.real() + a.imag() * b.imag();
  }
} // namespace matumoto

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