// @(#)root/eve:$Id: TEveVector.cxx 31517 2009-12-03 11:56:23Z matevz $
// Author: Matevz Tadel 2007

/*************************************************************************
 * Copyright (C) 1995-2007, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#include "TEveVector.h"
#include "TVector3.h"

//==============================================================================
// TEveVector
//==============================================================================

//______________________________________________________________________________
//
// Float three-vector; a inimal Float_t copy of TVector3 used to
// represent points and momenta (also used in VSD).

ClassImp(TEveVector);

//______________________________________________________________________________
void TEveVector::Set(const TVector3& v)
{
   // Set from TVector3.

   fX = v.x(); fY = v.y(); fZ = v.z();
}

//______________________________________________________________________________
void TEveVector::Dump() const
{
   // Dump to stdout as "(x, y, z)\n".

   printf("(%f, %f, %f)\n", fX, fY, fZ);
}

//______________________________________________________________________________
Float_t TEveVector::Eta() const
{
   // Calculate eta of the point, pretending it's a momentum vector.

   Float_t cosTheta = CosTheta();
   if (cosTheta*cosTheta < 1) return -0.5* TMath::Log( (1.0-cosTheta)/(1.0+cosTheta) );
   Warning("Eta","transverse momentum = 0, returning +/- 1e10");
   return (fZ >= 0) ? 1e10 : -1e10;
}

//______________________________________________________________________________
void TEveVector::Normalize(Float_t length)
{
   // Normalize the vector to length if current length is non-zero.

   Float_t m = Mag();
   if (m != 0)
   {
      m = length / m;
      fX *= m; fY *= m; fZ *= m;
   }
}

//______________________________________________________________________________
TEveVector TEveVector::Orthogonal() const
{
   // Returns an orthogonal vector (not normalized).

   Float_t xx = fX < 0 ? -fX : fX;
   Float_t yy = fY < 0 ? -fY : fY;
   Float_t zz = fZ < 0 ? -fZ : fZ;
   if (xx < yy) {
      return xx < zz ? TEveVector(0,fZ,-fY) : TEveVector(fY,-fX,0);
   } else {
      return yy < zz ? TEveVector(-fZ,0,fX) : TEveVector(fY,-fX,0);
   }
}

//______________________________________________________________________________
void TEveVector::OrthoNormBase(TEveVector& a, TEveVector& b) const
{
   // Set vectors a and b to be normal to this and among themselves,
   // both of length 1.

   a = Orthogonal();
   TMath::Cross(this->Arr(), a.Arr(), b.Arr());
   a.Normalize();
   b.Normalize();
}

//______________________________________________________________________________
TEveVector TEveVector::operator + (const TEveVector & b) const
{
   // Vector addition.

   return TEveVector(fX + b.fX, fY + b.fY, fZ + b.fZ);
}

//______________________________________________________________________________
TEveVector TEveVector::operator - (const TEveVector & b) const
{
   // Vector subtraction.

   return TEveVector(fX - b.fX, fY - b.fY, fZ - b.fZ);
}

//______________________________________________________________________________
TEveVector TEveVector::operator * (Float_t a) const
{
   // Multiplication with scalar.

   return TEveVector(a*fX, a*fY, a*fZ);
}


//==============================================================================
// TEveVector4
//==============================================================================

//______________________________________________________________________________
//
// Float four-vector.

ClassImp(TEveVector4);

//______________________________________________________________________________
void TEveVector4::Dump() const
{
   // Dump to stdout as "(x, y, z; t)\n".

   printf("(%f, %f, %f; %f)\n", fX, fY, fZ, fT);
}


//==============================================================================
// TEvePathMark
//==============================================================================

//______________________________________________________________________________
//
// Special-point on track:
//  kDaughter  - daughter creation; fP is momentum of the daughter, it is subtracted from
//               momentum of the track
//  kReference - position/momentum reference
//  kDecay     - decay point, fP not used
//  kCluster2D - measurement with large error in one direction (like strip detectors):
//               fP - normal to detector plane,
//               fE - large error direction, must be normalized.
//               Track is propagated to plane and correction in fE direction is discarded.

ClassImp(TEvePathMark);

//______________________________________________________________________________
const char* TEvePathMark::TypeName()
{
   // Return the name of path-mark type.

   switch (fType)
   {
      case kDaughter:  return "Daughter";
      case kReference: return "Reference";
      case kDecay:     return "Decay";
      case kCluster2D: return "Cluster2D";
      default:         return "Unknown";
   }
}