GeoVectorLocalTransformation.cxx

Go to the documentation of this file.

/**
 * @file   larcorealg/Geometry/GeoVectorLocalTransformation.cxx
 * @brief  Specialization of local-to-world transformations for ROOT GenVector.
 * @author Gianluca Petrillo (petrillo@slac.stanford.edu)
 * @date   January 31, 2019
 * @see    `larcorealg/Geometry/GeoVectorLocalTransformation.h`
 * @ingroup Geometry
 *
 * This is a header-only library.
 */

// LArSoft libraries
#include "larcorealg/Geometry/GeoVectorLocalTransformation.h"

// ROOT libraries
#include "TGeoMatrix.h"

// C++ standard library
#include <stdexcept> // std::runtime_error


//------------------------------------------------------------------------------
template <>
void geo::LocalTransformation<ROOT::Math::Transform3D>::LocalToWorld
  (double const* local, double* world) const
{
  details::checkVectorBufferOverlap(local, world);

  // need direct transformation
  auto const local_v
    = geo::vect::makeFromCoords<typename TransformationMatrix_t::Point>(local);
  auto const world_v = fGeoMatrix(local_v);
  geo::vect::fillCoords(world, world_v);

} // geo::LocalTransformation::LocalToWorld()


//------------------------------------------------------------------------------
template <>
void geo::LocalTransformation<ROOT::Math::Transform3D>::LocalToWorldVect
  (double const* local, double* world) const
{
  details::checkVectorBufferOverlap(local, world);

  // need direct transformation
  auto const local_v
    = geo::vect::makeFromCoords<typename TransformationMatrix_t::Vector>(local);
  auto const world_v = fGeoMatrix(local_v);
  geo::vect::fillCoords(world, world_v);

} // geo::LocalTransformation::LocalToWorldVect()


//------------------------------------------------------------------------------
template <>
void geo::LocalTransformation<ROOT::Math::Transform3D>::WorldToLocal
  (double const* world, double* local) const
{
  details::checkVectorBufferOverlap(local, world);

  // need inverse transformation
  auto const world_v
    = geo::vect::makeFromCoords<typename TransformationMatrix_t::Point>(world);
  auto const local_v = fGeoMatrix.ApplyInverse(world_v);
  geo::vect::fillCoords(local, local_v);

} // geo::LocalTransformation::WorldToLocal()


//------------------------------------------------------------------------------
template <>
void geo::LocalTransformation<ROOT::Math::Transform3D>::WorldToLocalVect
  (const double* world, double* local) const
{
  details::checkVectorBufferOverlap(local, world);

  // need inverse transformation
  auto const world_v
    = geo::vect::makeFromCoords<typename TransformationMatrix_t::Vector>(world);
  auto const local_v = fGeoMatrix.ApplyInverse(world_v);
  geo::vect::fillCoords(local, local_v);

} // geo::LocalTransformation::WorldToLocalVect()


//------------------------------------------------------------------------------
ROOT::Math::Transform3D
geo::details::TransformationMatrixConverter<ROOT::Math::Transform3D, TGeoMatrix>
  ::convert
  (TGeoMatrix const& trans)
{
  double const* rot    = trans.GetRotationMatrix();
  double const* transl = trans.GetTranslation();
  double const* scale  = trans.GetScale();

  for (auto ptr = scale; ptr != scale + 3; ++ptr)
    if (*ptr != 1.0)
      throw std::runtime_error
        ("Matrix with scaling can't be converted to Transform3D");

  return {
    rot[0], rot[1], rot[2], transl[0],
    rot[3], rot[4], rot[5], transl[1],
    rot[6], rot[7], rot[8], transl[2]
    };

} // geo::details::TransformationMatrixConverter<TGeoMatrix, Transform3D>::convert()


//------------------------------------------------------------------------------