// -*- Mode : c++ -*-
//
// SUMMARY  :
// USAGE    :
// ORG      :
// AUTHOR   : Frederic Hecht
// E-MAIL   : hecht@ann.jussieu.fr
//

/*

 This file is part of Freefem++

 Freefem++ is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published by
 the Free Software Foundation; either version 2.1 of the License, or
 (at your option) any later version.

 Freefem++  is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public License
 along with Freefem++; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef R2_H_
#define R2_H_

namespace bamg {
  template< class R, class RR >
  class P2xP2;

  template< class R, class RR >
  class P2 {

   public:
    R x, y;
    P2( ) : x(0), y(0){}
    P2(R a, R b) : x(a), y(b) {}
    P2(P2 A, P2 B) : x(B.x - A.x), y(B.y - A.y) {}
    P2< R, RR > operator+(const P2< R, RR >& cc) const { return P2< R, RR >(x + cc.x, y + cc.y); }
    P2< R, RR > operator-(const P2< R, RR >& cc) const { return P2< R, RR >(x - cc.x, y - cc.y); }
    P2< R, RR > operator-( ) const { return P2< R, RR >(-x, -y); }
    //  RR   operator*(const P2<R,RR> & cc) const {return  (RR) x* (RR) cc.x+(RR) y* (RR) cc.y;} //
    //  produit scalaire
    RR operator,(const P2< R, RR >& cc) const {
      return (RR)x * (RR)cc.x + (RR)y * (RR)cc.y;
    }    // produit scalaire
    P2< R, RR > operator*(R cc) const { return P2< R, RR >(x * cc, y * cc); }
    // P2<R,RR>   operator*(RR  cc) const {return P2<R,RR>((R)(x*cc),(R)(y*cc));}
    P2< R, RR > operator/(R cc) const { return P2< R, RR >(x / cc, y / cc); }
    P2< R, RR > operator+=(const P2< R, RR >& cc) {
      x += cc.x;
      y += cc.y;
      return *this;
    }
    P2< R, RR > operator/=(const R r) {
      x /= r;
      y /= r;
      return *this;
    }
    P2< R, RR > operator*=(const R r) {
      x *= r;
      y *= r;
      return *this;
    }
    P2< R, RR > operator-=(const P2< R, RR >& cc) {
      x -= cc.x;
      y -= cc.y;
      return *this;
    }
    //  P2<R,RR> Orthogonal(const   P2<R,RR> r) {return P2<R,RR>(-r.y,r.x);}
  };

  template< class R, class RR >
  class P2xP2 {    // x ligne 1 y ligne2

    friend ostream& operator<<(ostream& f, const P2xP2< R, RR >& c) {
      f << '[' << c.x << ',' << c.y << ']' << flush;
      return f;
    }

    friend P2< R, RR > operator*(P2< R, RR > c, P2xP2< R, RR > cc) {
      return P2< R, RR >(c.x * cc.x.x + c.y * cc.y.x, c.x * cc.x.y + c.y * cc.y.y);
    }

   public:
    P2< R, RR > x, y;
    P2xP2( ) : x( ), y( ) {}
    P2xP2(P2< R, RR > a, P2< R, RR > b) : x(a), y(b) {}
    P2xP2(P2< R, RR > a, P2< R, RR > b, P2< R, RR > c) : x(b - a), y(c - a) {}
    P2xP2(R xx, R xy, R yx, R yy) : x(xx, xy), y(yx, yy) {}
    P2< R, RR > operator*(const P2< R, RR > c) const {
      return P2< R, RR >(x.x * c.x + x.y * c.y, y.x * c.x + y.y * c.y);
    }
    P2xP2< R, RR > operator*(P2xP2< R, RR > c) const {
      return P2xP2< R, RR >(x.x * c.x.x + x.y * c.y.x, x.x * c.x.y + x.y * c.y.y,
                            y.x * c.x.x + y.y * c.y.x, y.x * c.x.y + y.y * c.y.y);
    }
    RR det( ) const { return (RR)x.x * (RR)y.y - (RR)x.y * (RR)y.x; }
    P2xP2< R, RR > inv( ) const {
      RR d = (*this).det( );
      return P2xP2< R, RR >((R)(y.y / d), (R)(-x.y / d), (R)(-y.x / d), (R)(x.x / d));
    }
    P2xP2< R, RR > t( ) { return P2xP2< R, RR >(x.x, y.x, x.y, y.y); }    // transposer
    P2< R, RR > tx( ) { return P2< R, RR >(x.x, y.x); }
    P2< R, RR > ty( ) { return P2< R, RR >(x.y, y.y); }
  };

  // template  <class R,class RR>  // transposer
  // inline P2xP2<R,RR> t(P2xP2<R,RR> m)
  //   {return P2xP2<R,RR>(m.x.x,m.y.x,m.x.y,m.y.y);}

  template< class R, class RR >
  inline RR Det(const P2< R, RR > x, const P2< R, RR > y) {
    return (RR)x.x * (RR)y.y - (RR)x.y * (RR)y.x;
  }

  template< class R, class RR >
  inline RR Area2(const P2< R, RR > a, const P2< R, RR > b, const P2< R, RR > c) {
    return Det(b - a, c - a);
  }

  template< class R, class RR >
  inline R Norme1(const P2< R, RR > x) {
    return (Abs(x.x) + Abs(x.y));
  }

  template< class R, class RR >
  inline R NormeInfini(const P2< R, RR > x) {
    return Max(Abs(x.x), Abs(x.y));
  }

  template< class R, class RR >
  inline RR Norme2_2(const P2< R, RR > x) {
    return (RR)x.x * (RR)x.x + (RR)x.y * (RR)x.y;
  }

  template< class R, class RR >
  inline RR Norme2(const P2< R, RR > x) {
    return sqrt((RR)x.x * (RR)x.x + (RR)x.y * (RR)x.y);
  }

  template< class R, class RR >
  inline P2< R, RR > Orthogonal(const P2< R, RR > x) {
    return P2< R, RR >(-x.y, x.x);
  }

  template< class R, class RR >
  inline ostream& operator<<(ostream& f, const P2< R, RR >& c) {
    f << '[' << c.x << ',' << c.y << ']' << flush;
    return f;
  }

  /*template  <class R,class RR>
  inline P2<R,RR> Min2(P2<R,RR> x,P2<R,RR> y)
     {return  P2<R,RR>(Min(x.x,y.x),Min(x.y,y.y) ;}

  template  <class R,class RR>
  inline P2<R,RR> Max2(P2<R,RR> x,P2<R,RR> y)
     {return  P2<R,RR>(Max(x.x,y.x),Max(x.y,y.y) ;}
  */
}    // namespace bamg

#endif    // R2_H_
