// @(#)root/physics:$Name$:$Id$
// Author: Peter Malzacher   19/06/99

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#ifndef ROOT_TLorentzRotation
#define ROOT_TLorentzRotation


#ifndef ROOT_TRotation
#include "TRotation.h"
#endif
#ifndef ROOT_TLorentzVector
#include "TLorentzVector.h"
#endif


class TLorentzRotation : public TObject {


public:

  class TLorentzRotationRow {
  public:
    inline TLorentzRotationRow(const TLorentzRotation &, int);
    inline Double_t operator [] (int) const;
  private:
    const TLorentzRotation * rr;
    int ii;
  };
  // Helper class for implemention of C-style subscripting r[i][j]

  TLorentzRotation();
  // Default constructor. Gives a unit matrix.

  TLorentzRotation(const TRotation &);
  // Constructor for 3d rotations.

  TLorentzRotation(const TLorentzRotation &);
  // Copy constructor.

  TLorentzRotation(Double_t, Double_t, Double_t);
  TLorentzRotation(const TVector3 &);
  // Constructors giving a Lorenz-boost.

  inline Double_t XX() const;
  inline Double_t XY() const;
  inline Double_t XZ() const;
  inline Double_t XT() const;
  inline Double_t YX() const;
  inline Double_t YY() const;
  inline Double_t YZ() const;
  inline Double_t YT() const;
  inline Double_t ZX() const;
  inline Double_t ZY() const;
  inline Double_t ZZ() const;
  inline Double_t ZT() const;
  inline Double_t TX() const;
  inline Double_t TY() const;
  inline Double_t TZ() const;
  inline Double_t TT() const;
  // Elements of the matrix.

  inline TLorentzRotationRow operator [] (int) const;
  // Returns object of the helper class for C-style subscripting r[i][j]


  Double_t operator () (int, int) const;
  // Fortran-style subscriptimg: returns (i,j) element of the matrix.


  inline TLorentzRotation & operator = (const TLorentzRotation &);
  inline TLorentzRotation & operator = (const TRotation &);
  // Assignment.

  inline Bool_t operator == (const TLorentzRotation &) const;
  inline Bool_t operator != (const TLorentzRotation &) const;
  // Comparisons.

  inline Bool_t IsIdentity() const;
  // Returns true if the Identity matrix.

  inline TLorentzVector VectorMultiplication(const TLorentzVector&) const;
  inline TLorentzVector operator * (const TLorentzVector &) const;
  // Multiplication with a Lorentz vector.

  TLorentzRotation MatrixMultiplication(const TLorentzRotation &) const;
  inline TLorentzRotation operator * (const TLorentzRotation &) const;
  inline TLorentzRotation & operator *= (const TLorentzRotation &);
  inline TLorentzRotation & Transform(const TLorentzRotation &);
  inline TLorentzRotation & Transform(const TRotation &);
  // Matrix multiplication.
  // Note: a *= b; <=> a = a * b; while a.Transform(b); <=> a = b * a;

  inline TLorentzRotation Inverse() const;
  // Return the inverse.

  inline TLorentzRotation & Invert();
  // Inverts the LorentzRotation matrix.

  inline TLorentzRotation & Boost(Double_t, Double_t, Double_t);
  inline TLorentzRotation & Boost(const TVector3 &);
  // Lorenz boost.

  inline TLorentzRotation & RotateX(Double_t);
  // Rotation around x-axis.

  inline TLorentzRotation & RotateY(Double_t);
  // Rotation around y-axis.

  inline TLorentzRotation & RotateZ(Double_t);
  // Rotation around z-axis.

  inline TLorentzRotation & Rotate(Double_t, const TVector3 &);
  inline TLorentzRotation & Rotate(Double_t, const TVector3 *);
  // Rotation around specified vector.

protected:

  Double_t fxx, fxy, fxz, fxt,
            fyx, fyy, fyz, fyt,
            fzx, fzy, fzz, fzt,
            ftx, fty, ftz, ftt;
  // The matrix elements.

  void SetBoost(Double_t, Double_t, Double_t);
  // Set elements according to a boost vector.

  TLorentzRotation(Double_t, Double_t, Double_t, Double_t,
                   Double_t, Double_t, Double_t, Double_t,
                   Double_t, Double_t, Double_t, Double_t,
                   Double_t, Double_t, Double_t, Double_t);
  // Protected constructor.

  ClassDef(TLorentzRotation,1) // Lorentz transformations including boosts and rotations

};



inline Double_t TLorentzRotation::XX() const { return fxx; }
inline Double_t TLorentzRotation::XY() const { return fxy; }
inline Double_t TLorentzRotation::XZ() const { return fxz; }
inline Double_t TLorentzRotation::XT() const { return fxt; }
inline Double_t TLorentzRotation::YX() const { return fyx; }
inline Double_t TLorentzRotation::YY() const { return fyy; }
inline Double_t TLorentzRotation::YZ() const { return fyz; }
inline Double_t TLorentzRotation::YT() const { return fyt; }
inline Double_t TLorentzRotation::ZX() const { return fzx; }
inline Double_t TLorentzRotation::ZY() const { return fzy; }
inline Double_t TLorentzRotation::ZZ() const { return fzz; }
inline Double_t TLorentzRotation::ZT() const { return fzt; }
inline Double_t TLorentzRotation::TX() const { return ftx; }
inline Double_t TLorentzRotation::TY() const { return fty; }
inline Double_t TLorentzRotation::TZ() const { return ftz; }
inline Double_t TLorentzRotation::TT() const { return ftt; }

inline TLorentzRotation::TLorentzRotationRow::TLorentzRotationRow
(const TLorentzRotation & r, int i) : rr(&r), ii(i) {}

inline Double_t
TLorentzRotation::TLorentzRotationRow::operator [] (int jj) const {
  return rr->operator()(ii,jj);
}

inline TLorentzRotation::TLorentzRotationRow
TLorentzRotation::operator [] (int i) const {
  return TLorentzRotationRow(*this, i);
}

inline TLorentzRotation &
TLorentzRotation::operator = (const TLorentzRotation & r) {
  fxx = r.fxx; fxy = r.fxy; fxz = r.fxz; fxt = r.fxt;
  fyx = r.fyx; fyy = r.fyy; fyz = r.fyz; fyt = r.fyt;
  fzx = r.fzx; fzy = r.fzy; fzz = r.fzz; fzt = r.fzt;
  ftx = r.ftx; fty = r.fty; ftz = r.ftz; ftt = r.ftt;
  return *this;
}

//inline TLorentzRotation &
//TLorentzRotation::operator = (const TRotation & r) {
//  mxx = r.xx(); mxy = r.xy(); mxz = r.xz(); mxt = 0.0;
//  myx = r.yx(); myy = r.yy(); myz = r.yz(); myt = 0.0;
//  mzx = r.zx(); mzy = r.zy(); mzz = r.zz(); mzt = 0.0;
//  mtx = 0.0;    mty = 0.0;    mtz = 0.0;    mtt = 1.0;
//  return *this;
//}

inline TLorentzRotation &
TLorentzRotation::operator = (const TRotation & r) {
  fxx = r.XX(); fxy = r.XY(); fxz = r.XZ(); fxt = 0.0;
  fyx = r.YX(); fyy = r.YY(); fyz = r.YZ(); fyt = 0.0;
  fzx = r.ZX(); fzy = r.ZY(); fzz = r.ZZ(); fzt = 0.0;
  ftx = 0.0;    fty = 0.0;    ftz = 0.0;    ftt = 1.0;
  return *this;
}


//inline Bool_t
//TLorentzRotation::operator == (const TLorentzRotation & r) const {
//  return (mxx == r.xx() && mxy == r.xy() && mxz == r.xz() && mxt == r.xt() &&
//          myx == r.yx() && myy == r.yy() && myz == r.yz() && myt == r.yt() &&
//          mzx == r.zx() && mzy == r.zy() && mzz == r.zz() && mzt == r.zt() &&
//          mtx == r.tx() && mty == r.ty() && mtz == r.tz() && mtt == r.tt())
//  ? kTRUE : kFALSE;
//}

inline Bool_t
TLorentzRotation::operator == (const TLorentzRotation & r) const {
  return (fxx == r.fxx && fxy == r.fxy && fxz == r.fxz && fxt == r.fxt &&
          fyx == r.fyx && fyy == r.fyy && fyz == r.fyz && fyt == r.fyt &&
          fzx == r.fzx && fzy == r.fzy && fzz == r.fzz && fzt == r.fzt &&
          ftx == r.ftx && fty == r.fty && ftz == r.ftz && ftt == r.ftt)
  ? kTRUE : kFALSE;
}

//inline Bool_t
//TLorentzRotation::operator != (const TLorentzRotation & r) const {
//  return (mxx != r.xx() || mxy != r.xy() || mxz != r.xz() || mxt != r.xt() ||
//          myx != r.yx() || myy != r.yy() || myz != r.yz() || myt != r.yt() ||
//          mzx != r.zx() || mzy != r.zy() || mzz != r.zz() || mzt != r.zt() ||
//          mtx != r.tx() || mty != r.ty() || mtz != r.tz() || mtt != r.tt())
//  ? kTRUE : kFALSE;
//}

inline Bool_t
TLorentzRotation::operator != (const TLorentzRotation & r) const {
  return (fxx != r.fxx || fxy != r.fxy || fxz != r.fxz || fxt != r.fxt ||
          fyx != r.fyx || fyy != r.fyy || fyz != r.fyz || fyt != r.fyt ||
          fzx != r.fzx || fzy != r.fzy || fzz != r.fzz || fzt != r.fzt ||
          ftx != r.ftx || fty != r.fty || ftz != r.ftz || ftt != r.ftt)
  ? kTRUE : kFALSE;
}

inline Bool_t TLorentzRotation::IsIdentity() const {
  return (fxx == 1.0 && fxy == 0.0 && fxz == 0.0 && fxt == 0.0 &&
          fyx == 0.0 && fyy == 1.0 && fyz == 0.0 && fyt == 0.0 &&
          fzx == 0.0 && fzy == 0.0 && fzz == 1.0 && fzt == 0.0 &&
          ftx == 0.0 && fty == 0.0 && ftz == 0.0 && ftt == 1.0)
  ? kTRUE : kFALSE;
}


inline TLorentzVector
TLorentzRotation::VectorMultiplication(const TLorentzVector & p) const {
  return TLorentzVector(fxx*p.X()+fxy*p.Y()+fxz*p.Z()+fxt*p.T(),
                          fyx*p.X()+fyy*p.Y()+fyz*p.Z()+fyt*p.T(),
                          fzx*p.X()+fzy*p.Y()+fzz*p.Z()+fzt*p.T(),
                          ftx*p.X()+fty*p.Y()+ftz*p.Z()+ftt*p.T());
}

inline TLorentzVector
TLorentzRotation::operator * (const TLorentzVector & p) const {
  return VectorMultiplication(p);
}

inline TLorentzRotation
TLorentzRotation::operator * (const TLorentzRotation & m) const {
  return MatrixMultiplication(m);
}

inline TLorentzRotation &
TLorentzRotation::operator *= (const TLorentzRotation & m) {
  return *this = MatrixMultiplication(m);
}

inline TLorentzRotation &
TLorentzRotation::Transform(const TLorentzRotation & m) {
  return *this = m.MatrixMultiplication(*this);
}

inline TLorentzRotation &
TLorentzRotation::Transform(const TRotation & m){
  return Transform(TLorentzRotation(m));
}

inline TLorentzRotation TLorentzRotation::Inverse() const {
  return TLorentzRotation( fxx,  fyx,  fzx, -ftx,
                             fxy,  fyy,  fzy, -fty,
                             fxz,  fyz,  fzz, -ftz,
                            -fxt, -fyt, -fzt,  ftt);
}

inline TLorentzRotation & TLorentzRotation::Invert() {
  return *this = Inverse();
}

inline TLorentzRotation &
TLorentzRotation::Boost(Double_t bx, Double_t by, Double_t bz) {
  return Transform(TLorentzRotation(bx, by, bz));
}

inline TLorentzRotation &
TLorentzRotation::Boost(const TVector3 & b) {
  return Transform(TLorentzRotation(b));
}

inline TLorentzRotation &
TLorentzRotation::RotateX(Double_t angle) {
  return Transform(TRotation().RotateX(angle));
}

inline TLorentzRotation &
TLorentzRotation::RotateY(Double_t angle) {
  return Transform(TRotation().RotateY(angle));
}

inline TLorentzRotation &
TLorentzRotation::RotateZ(Double_t angle) {
  return Transform(TRotation().RotateZ(angle));
}

inline TLorentzRotation &
TLorentzRotation::Rotate(Double_t angle, const TVector3 & axis) {
  return Transform(TRotation().Rotate(angle, axis));
}

inline TLorentzRotation &
TLorentzRotation::Rotate(Double_t angle, const TVector3 * axis) {
  return Transform(TRotation().Rotate(angle, axis));
}

#endif