//-*- mode: c++ -*-
//
//  $Id: BrPlane3D.h,v 1.2 2001/07/19 18:12:28 ekman Exp $
//
#ifndef BRAT_BrPlane3D
#define BRAT_BrPlane3D

//////////////////////////////////////////////////////////////////////////////
//                                                                          //
//  BrPlane3D                                                               //
//                                                                          //
//  3D Plane. Part of the Geometry classes Points, Vector, Lines, Planes.   //
//                                                                          //
//  Author:   K. Hagel                                                      //
//  Created:  December 1998                                                 //
//                                                                          //
//                                                                          //
//////////////////////////////////////////////////////////////////////////////

//
// ROOT classes
//
#include <BrIostream.h>
#ifndef ROOT_TObject
#include "TObject.h"
#endif

class BrVector3D;
class BrLine3D;

class BrPlane3D : public TObject {

public:

  // constructors and destructors
  //
  BrPlane3D(const Double_t a=0, const Double_t b=0, const Double_t c=0 , const Double_t d=0) :
    fA(a), fB(b), fC(c), fD(d) {};

  BrPlane3D(const BrVector3D &p1, const BrVector3D &p2, const BrVector3D &p3);
  BrPlane3D(const BrVector3D &point, const BrVector3D &);
  BrPlane3D(const Double_t x1, const Double_t y1, const Double_t z1,
            const Double_t x2, const Double_t y2, const Double_t z2,
            const Double_t x3, const Double_t y3, const Double_t z3 );
  virtual ~BrPlane3D(){};
  
  BrPlane3D(const BrPlane3D& plane) : fA(plane.fA), fB(plane.fB), fC(plane.fC), fD(plane.fD) {};
  BrPlane3D&      operator = (const BrPlane3D&);
  //
  // general field operators
  BrPlane3D&      operator +=(const BrPlane3D&);
  BrPlane3D&      operator -=(const BrPlane3D&);
  BrPlane3D       operator - () const;
  BrPlane3D       operator + () const;
  const Double_t& operator [] (size_t) const;
  Double_t&       operator [] (size_t);

  const Double_t& operator () (size_t) const;
  Double_t&       operator () (size_t);

  Bool_t          operator == (const BrPlane3D&) const;
  Bool_t          operator != (const BrPlane3D&) const;

  // access methods
  Double_t        GetA() const {return fA;};
  Double_t        GetB() const {return fB;};
  Double_t        GetC() const {return fC;};
  Double_t        GetD() const {return fD;};

//Setter methods
  void            SetA(Double_t value) { fA = value;};
  void            SetB(Double_t value) { fB = value;};
  void            SetC(Double_t value) { fC = value;};
  void            SetD(Double_t value) { fD = value;};

  void            Set(const BrVector3D &p1, const BrVector3D &p2, const BrVector3D &p3);
  BrVector3D      UnitNormal();
  BrVector3D      GetIntersectionWithLine(const BrLine3D &line);
  Double_t        GetMinimumDistanceFromPlane(const BrVector3D &point);

 private:

//Coefficients for the planes  
  Double_t fA;  //  1. Plane Coefficient
  Double_t fB;  //  2. Plane Coefficient
  Double_t fC;  //  3. Plane Coefficient
  Double_t fD;  //  4. Plane Coefficient
  
  friend BrPlane3D operator+(const BrPlane3D& v1, const BrPlane3D& v2);
  friend BrPlane3D operator-(const BrPlane3D& v1, const BrPlane3D& v2);
  friend BrPlane3D operator*(Double_t a, const BrPlane3D& v2);
  friend BrPlane3D operator*(const BrPlane3D& v1, Double_t a);
  friend BrPlane3D operator/(const BrPlane3D& v1, Double_t a); 
  ClassDef(BrPlane3D,1)
    
};
    
//
// Related Global functions
//

ostream& operator<<(ostream& str, const BrPlane3D&);
istream& operator>>(istream& str, BrPlane3D&);

#endif
//  $Log: BrPlane3D.h,v $
//  Revision 1.2  2001/07/19 18:12:28  ekman
//  Added method to set a,b,c,d after initialisation from 3 vectors.
//
//  Revision 1.1.1.1  2001/06/21 14:55:20  hagel
//  Initial revision of brat2
//
//  Revision 1.8  2001/04/30 21:17:07  videbaek
//  Added method to create Plane3D from a point and a normal vector.
//  Considered removing the add, divide which have a marginal precise definition.
//
//
//  Revision 1.7  1999/03/07 00:00:44  hagel
//
//  Revision 1.6  1999/01/21 23:23:24  hagel
//  1. Changed convention for checking includes.  Current convention is:
//     BRAT_Br...... eg BRAT_BrModule ala ROOT.
//  2. Added CVS logs to .h files that didn't have them.
//  3. Moved checking of include definition to first line for easier reading
//  4. Put checks before all includes in the include files as per BRAT specifications
//  5. Added BrGeantHeader to Geant Makefile
//  6. All changes have been checked to compile on NT ala Cygnus
//
//  Revision 1.5  1998/12/18 19:37:14  hagel
//  Implement UnitNormal
//
//  Revision 1.4  1998/12/18 17:21:55  hagel
//  Implement minimum distance from point to plane plus add comments
//
//  Revision 1.3  1998/12/17 21:16:12  hagel
//  Add CVS comments
//