cpp/geometry/line.hpp

• View this file on GitHub
• Last update: 2023-07-20 23:39:52+09:00
• Include: #include "cpp/geometry/line.hpp"

Depends on

• cpp/geometry/line-segment.hpp
• cpp/geometry/linevec.hpp
• cpp/geometry/point.hpp
• cpp/geometry/vec.hpp

Required by

• cpp/geometry/projection.cpp
• cpp/geometry/reflection.cpp
• cpp/geometry/two-points-distance.cpp

Verified with

• cpp/z_test/aoj-CGL_1_A.test.cpp

Code

#pragma once
#include "linevec.hpp"
#include "point.hpp"
#include "vec.hpp"

struct Line{
  //ax+by+c=0 (required: a*a+b*b != 0)
  long double a,b,c;
  Line(long double a, long double b, long double c): a(a), b(b), c(c){}
  Line(LineVec lv){
    a = -lv.vec.y;
    b = lv.vec.x;
    c = -(a*lv.base.x + b*lv.base.y);
  }

  Line operator/(long double v){
    return {a/v, b/v, c/v};
  }

  Line(LineSegment ls){
    (*this) = (LineVec)(ls);
  }
  Line(Point a, Point b){
    LineSegment ls({a,b});
    (*this) = (LineSegment)(ls);
  }
};

Line standardize(Line l){
  return l/sqrt(l.a*l.a+l.b*l.b);
}
long double distance(Line l, Point p){
  Line nl = standardize(l);
  return nl.a*p.x + nl.b*p.y + nl.c;
}
Vec normal(Line l){
  Vec v = {-l.a, -l.b};
  return standardize(v);
}

#line 2 "cpp/geometry/vec.hpp"

struct Vec{
  long double x,y;
  Vec operator*(long double a){
    return {x*a, y*a};
  }
  Vec operator/(long double a){
    return {x/a, y/a};
  }

  friend ostream &operator<<(ostream &os, const Vec &p){
    return os << p.x << " " << p.y;
  }
};

long double magnitude(Vec v){
  return sqrt(v.x*v.x+v.y*v.y);
}

Vec standardize(Vec v){
  return v/magnitude(v);
}
#line 3 "cpp/geometry/point.hpp"

struct Point{
  long double x,y;

  Vec operator-(Point b){
    return {x-b.x, y-b.y};
  }
  Point operator+(long double a){
    return {x+a, y+a};
  }
  Point operator+(Vec v){
    return {x+v.x, y+v.y};
  }

  friend istream &operator>>(istream &is, Point &p){
    long double a,b;
    cin>>a>>b;
    p = Point({a,b});
    return (is);
  }

  friend ostream &operator<<(ostream &os, const Point &p){
    return os << p.x << " " << p.y;
  }

};
#line 2 "cpp/geometry/line-segment.hpp"

#line 4 "cpp/geometry/line-segment.hpp"

struct LineSegment{
  Point first, second;
  LineSegment(Point a, Point b):first(a),second(b){}
};


#line 5 "cpp/geometry/linevec.hpp"

struct LineVec{
  Point base;
  Vec vec;
  LineVec(LineSegment ls){
    base = ls.first;
    vec = ls.second - ls.first;
  }
};
#line 5 "cpp/geometry/line.hpp"

struct Line{
  //ax+by+c=0 (required: a*a+b*b != 0)
  long double a,b,c;
  Line(long double a, long double b, long double c): a(a), b(b), c(c){}
  Line(LineVec lv){
    a = -lv.vec.y;
    b = lv.vec.x;
    c = -(a*lv.base.x + b*lv.base.y);
  }

  Line operator/(long double v){
    return {a/v, b/v, c/v};
  }

  Line(LineSegment ls){
    (*this) = (LineVec)(ls);
  }
  Line(Point a, Point b){
    LineSegment ls({a,b});
    (*this) = (LineSegment)(ls);
  }
};

Line standardize(Line l){
  return l/sqrt(l.a*l.a+l.b*l.b);
}
long double distance(Line l, Point p){
  Line nl = standardize(l);
  return nl.a*p.x + nl.b*p.y + nl.c;
}
Vec normal(Line l){
  Vec v = {-l.a, -l.b};
  return standardize(v);
}

Back to top page