DetPlane.cc

Go to the documentation of this file. Or view the newest version in sPHENIX GitHub for file DetPlane.cc

/* Copyright 2008-2010, Technische Universitaet Muenchen,
   Authors: Christian Hoeppner & Sebastian Neubert & Johannes Rauch

   This file is part of GENFIT.

   GENFIT 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 3 of the License, or
   (at your option) any later version.

   GENFIT 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 GENFIT.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "DetPlane.h"
#include "IO.h"

#include <cassert>
#include <cmath>
#include <TMath.h>
#include <TClass.h>
#include <TBuffer.h>

namespace genfit {


DetPlane::DetPlane(AbsFinitePlane* finite)
  :finitePlane_(finite)
{
  // default constructor
  o_.SetXYZ(0.,0.,0.);
  u_.SetXYZ(1.,0.,0.);
  v_.SetXYZ(0.,1.,0.);
  // sane() not needed here
}


DetPlane::DetPlane(const TVector3& o,
                       const TVector3& u,
                       const TVector3& v,
                       AbsFinitePlane* finite)
  :o_(o), u_(u), v_(v), finitePlane_(finite)
{
  sane();
}

DetPlane::DetPlane(const TVector3& o,
                       const TVector3& n,
                       AbsFinitePlane* finite)
  :o_(o), finitePlane_(finite)
{
  setNormal(n);
}


DetPlane::~DetPlane(){
  ;
}


DetPlane::DetPlane(const DetPlane& rhs) :
  TObject(rhs),
  o_(rhs.o_),
  u_(rhs.u_),
  v_(rhs.v_)
{
  if(rhs.finitePlane_)
    finitePlane_.reset(rhs.finitePlane_->clone());
  else finitePlane_.reset();
}


DetPlane& DetPlane::operator=(DetPlane other) {
  swap(other);
  return *this;
}


void DetPlane::swap(DetPlane& other) {
  // by swapping the members of two classes,
  // the two classes are effectively swapped
  std::swap(this->o_, other.o_);
  std::swap(this->u_, other.u_);
  std::swap(this->v_, other.v_);
  this->finitePlane_.swap(other.finitePlane_);
}


void DetPlane::set(const TVector3& o,
                const TVector3& u,
                const TVector3& v)
{
  o_ = o;
  u_ = u;
  v_ = v;
  sane();
}


void DetPlane::setO(const TVector3& o)
{
  o_ = o;
}

void DetPlane::setO(double X,double Y,double Z)
{
  o_.SetXYZ(X,Y,Z);
}

void DetPlane::setU(const TVector3& u)
{
  u_ = u;
  sane(); // sets v_ perpendicular to u_
}

void DetPlane::setU(double X,double Y,double Z)
{
  u_.SetXYZ(X,Y,Z);
  sane(); // sets v_ perpendicular to u_
}

void DetPlane::setV(const TVector3& v)
{
  v_ = v;
  u_ = getNormal().Cross(v_);
  u_ *= -1.;
  sane();
}

void DetPlane::setV(double X,double Y,double Z)
{
  v_.SetXYZ(X,Y,Z);
  u_ = getNormal().Cross(v_);
  u_ *= -1.;
  sane();
}

void DetPlane::setUV(const TVector3& u,const TVector3& v)
{
  u_ = u;
  v_ = v;
  sane();
}

void DetPlane::setON(const TVector3& o,const TVector3& n){
  o_ = o;
  setNormal(n);
}


TVector3 DetPlane::getNormal() const
{
  return u_.Cross(v_);
}

void DetPlane::setNormal(double X,double Y,double Z){
  setNormal( TVector3(X,Y,Z) );
}

void DetPlane::setNormal(const TVector3& n){
  u_ = n.Orthogonal();
  v_ = n.Cross(u_);
  u_.SetMag(1.);
  v_.SetMag(1.);
}

void DetPlane::setNormal(const double& theta, const double& phi){
  setNormal( TVector3(TMath::Sin(theta)*TMath::Cos(phi),TMath::Sin(theta)*TMath::Sin(phi),TMath::Cos(theta)) );
}


TVector2 DetPlane::project(const TVector3& x)const
{
  return TVector2(u_*x, v_*x);
}


TVector2 DetPlane::LabToPlane(const TVector3& x)const
{
  return project(x-o_);
}


TVector3 DetPlane::toLab(const TVector2& x)const
{
  TVector3 d(o_);
  d += x.X()*u_;
  d += x.Y()*v_;
  return d;
}


TVector3 DetPlane::dist(const TVector3& x)const
{
  return toLab(LabToPlane(x)) - x;
}


void DetPlane::sane(){
  assert(u_!=v_);

  // ensure unit vectors
  u_.SetMag(1.);
  v_.SetMag(1.);

  // check if already orthogonal
  if (u_.Dot(v_) < 1.E-5) return;

  // ensure orthogonal system
  v_ = getNormal().Cross(u_);
}


void DetPlane::Print(const Option_t* option) const
{
  printOut<<"DetPlane: "
     <<"O("<<o_.X()<<", "<<o_.Y()<<", "<<o_.Z()<<") "
     <<"u("<<u_.X()<<", "<<u_.Y()<<", "<<u_.Z()<<") "
     <<"v("<<v_.X()<<", "<<v_.Y()<<", "<<v_.Z()<<") "
     <<"n("<<getNormal().X()<<", "<<getNormal().Y()<<", "<<getNormal().Z()<<") "
       <<std::endl;
  if(finitePlane_ != nullptr) {
    finitePlane_->Print(option);
  }

}


/*
  I could write pages of comments about correct equality checking for
  floating point numbers, but: When two planes are as close as 10E-5 cm
  in all nine numbers that define the plane, this will be enough for all
  practical purposes
 */
bool operator== (const DetPlane& lhs, const DetPlane& rhs){
  if (&lhs == &rhs)
    return true;
  static const double detplaneEpsilon = 1.E-5;
  if(
     fabs( (lhs.o_.X()-rhs.o_.X()) ) > detplaneEpsilon  ||
     fabs( (lhs.o_.Y()-rhs.o_.Y()) ) > detplaneEpsilon  ||
     fabs( (lhs.o_.Z()-rhs.o_.Z()) ) > detplaneEpsilon
     ) return false;
  else if(
    fabs( (lhs.u_.X()-rhs.u_.X()) ) > detplaneEpsilon  ||
    fabs( (lhs.u_.Y()-rhs.u_.Y()) ) > detplaneEpsilon  ||
    fabs( (lhs.u_.Z()-rhs.u_.Z()) ) > detplaneEpsilon
    ) return false;
  else if(
    fabs( (lhs.v_.X()-rhs.v_.X()) ) > detplaneEpsilon  ||
    fabs( (lhs.v_.Y()-rhs.v_.Y()) ) > detplaneEpsilon  ||
    fabs( (lhs.v_.Z()-rhs.v_.Z()) ) > detplaneEpsilon
    ) return false;
  return true;
}

bool operator!= (const DetPlane& lhs, const DetPlane& rhs){
  return !(lhs==rhs);
}


double DetPlane::distance(const TVector3& point) const {
  // |(point - o_)*(u_ x v_)|
  return fabs( (point.X()-o_.X()) * (u_.Y()*v_.Z() - u_.Z()*v_.Y()) +
               (point.Y()-o_.Y()) * (u_.Z()*v_.X() - u_.X()*v_.Z()) +
               (point.Z()-o_.Z()) * (u_.X()*v_.Y() - u_.Y()*v_.X()));
}

double DetPlane::distance(double x, double y, double z) const {
  // |(point - o_)*(u_ x v_)|
  return fabs( (x-o_.X()) * (u_.Y()*v_.Z() - u_.Z()*v_.Y()) +
               (y-o_.Y()) * (u_.Z()*v_.X() - u_.X()*v_.Z()) +
               (z-o_.Z()) * (u_.X()*v_.Y() - u_.Y()*v_.X()));
}


TVector2 DetPlane::straightLineToPlane (const TVector3& point, const TVector3& dir) const {
  TVector3 dirNorm(dir.Unit());
  TVector3 normal = getNormal();
  double dirTimesN = dirNorm*normal;
  if(fabs(dirTimesN)<1.E-6){//straight line is parallel to plane, so return infinity
    return TVector2(1.E100,1.E100);
  }
  double t = 1./dirTimesN * ((o_-point)*normal);
  return project(point - o_ + t * dirNorm);
}


void DetPlane::straightLineToPlane(const double& posX, const double& posY, const double& posZ,
                                   const double& dirX, const double& dirY, const double& dirZ,
                                   double& u, double& v) const {

  TVector3 W = getNormal();
  double dirTimesN = dirX*W.X() + dirY*W.Y() + dirZ*W.Z();
  if(fabs(dirTimesN)<1.E-6){//straight line is parallel to plane, so return infinity
    u = 1.E100;
    v = 1.E100;
    return;
  }
  double t = 1./dirTimesN * ((o_.X()-posX)*W.X() +
                             (o_.Y()-posY)*W.Y() +
                             (o_.Z()-posZ)*W.Z());

  double posOnPlaneX = posX-o_.X() + t*dirX;
  double posOnPlaneY = posY-o_.Y() + t*dirY;
  double posOnPlaneZ = posZ-o_.Z() + t*dirZ;

  u = u_.X()*posOnPlaneX + u_.Y()*posOnPlaneY + u_.Z()*posOnPlaneZ;
  v = v_.X()*posOnPlaneX + v_.Y()*posOnPlaneY + v_.Z()*posOnPlaneZ;
}


void DetPlane::rotate(double angle) {
  TVector3 normal = getNormal();
  u_.Rotate(angle, normal);
  v_.Rotate(angle, normal);

  sane();
}


void DetPlane::reset() {
  o_.SetXYZ(0.,0.,0.);
  u_.SetXYZ(1.,0.,0.);
  v_.SetXYZ(0.,1.,0.);
  finitePlane_.reset();
}


void DetPlane::Streamer(TBuffer &R__b)
{
   // Stream an object of class genfit::DetPlane.
   // This is modified from the streamer generated by ROOT in order to 
   // account for the scoped_ptr.
   //This works around a msvc bug and should be harmless on other platforms
   typedef ::genfit::DetPlane thisClass;
   UInt_t R__s, R__c;
   if (R__b.IsReading()) {
      Version_t R__v = R__b.ReadVersion(&R__s, &R__c); if (R__v) { }
      //TObject::Streamer(R__b);
      o_.Streamer(R__b);
      u_.Streamer(R__b);
      v_.Streamer(R__b);
      finitePlane_.reset();
      char flag;
      R__b >> flag;
      if (flag) {
        // Read AbsFinitePlane with correct overload ... see comment
        // in writing code.
        TClass* cl = TClass::Load(R__b);
        AbsFinitePlane *p = (AbsFinitePlane*)(cl->New());
        cl->Streamer(p, R__b);
        finitePlane_.reset(p);
      }
      R__b.CheckByteCount(R__s, R__c, thisClass::IsA());
   } else {
      R__c = R__b.WriteVersion(thisClass::IsA(), kTRUE);
      //TObject::Streamer(R__b);
      o_.Streamer(R__b);
      u_.Streamer(R__b);
      v_.Streamer(R__b);
      if (finitePlane_) {
        R__b << (char)1;

        // finitPlane_ is a scoped_ptr, but a shared plane may be
        // written several times in different places (e.g. it may also
        // be stored in the measurement class).  Since we have no way
        // of knowing in which other places the same plane is written
        // (it may even be in another track!), we cannot synchronize
        // these writes and have to duplicate the SharedPlanePtr's
        // instead.  ROOT caches which pointers were written and read
        // if one uses 'R__b << p' or equivalent.  This can lead to
        // trouble have no way of synchronizing two reads to
        // shared_ptr's pointing to the same memory location.  But
        // even if we break the link between the two shared_ptr's,
        // ROOT will still try to outsmart us, and it will notice that
        // the finitePlane_ was the same during writing.  This will
        // lead to the same address being attached to two different
        // scoped_ptrs in reading.  Highly undesirable.  Since we
        // cannot know whether other parts of code implicitly or
        // explicitly rely on TBuffer's caching, we cannot just
        // disable this caching via R__b.ResetMap() (it's not
        // documented in any elucidating manner anyway).
        // 
        // Therefore, we have to write and read the AbsFinitePlane*
        // manually, bypassing ROOT's caching.  In order to do this,
        // we need the information on the actual type, because
        // otherwise we couldn't read it back reliably.  Finally, the
        // _working_ means of reading and writing class information
        // are TClass::Store and TClass::Load, again barely
        // documented, but if one tries any of the other ways that
        // suggest themselves, weird breakage will occur.
        finitePlane_->IsA()->Store(R__b);
        finitePlane_->Streamer(R__b);
      } else {
        R__b << (char)0;
      }
      R__b.SetByteCount(R__c, kTRUE);
   }
}
} /* End of namespace genfit */