3DConversions.cxx

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// @(#)root/mathcore:$Id$
// Authors: W. Brown, M. Fischler, L. Moneta    2005
 
/**********************************************************************
 *                                                                    *
 * Copyright (c) 2005, LCG ROOT FNAL MathLib Team                    *
 *                                                                    *
 *                                                                    *
 **********************************************************************/
 
// Source file for something else
//
// Created by: Mark Fischler and Walter Brown Thurs July 7, 2005
//
// Last update: $Id$
//
 
// TODO - For now, all conversions are grouped in this one compilation unit.
//        The intention is to seraparte them into a few .cpp files instead,
//        so that users needing one form need not incorporate code for them all.
 
#include "MathX/GenVectorX/3DConversions.h"
 
#include "Math/Math.h"
 
#include "MathX/GenVectorX/Rotation3D.h"
#include "MathX/GenVectorX/AxisAngle.h"
#include "MathX/GenVectorX/EulerAngles.h"
#include "MathX/GenVectorX/Quaternion.h"
#include "MathX/GenVectorX/RotationZYX.h"
#include "MathX/GenVectorX/RotationX.h"
#include "MathX/GenVectorX/RotationY.h"
#include "MathX/GenVectorX/RotationZ.h"
 
#include <limits>
 
#include "MathX/GenVectorX/AccHeaders.h"
 
#include "MathX/GenVectorX/MathHeaders.h"
 
namespace ROOT {
namespace ROOT_MATH_ARCH {
namespace gv_detail {
 
enum ERotation3DMatrixIndex {
   kXX = Rotation3D::kXX,
   kXY = Rotation3D::kXY,
   kXZ = Rotation3D::kXZ,
   kYX = Rotation3D::kYX,
   kYY = Rotation3D::kYY,
   kYZ = Rotation3D::kYZ,
   kZX = Rotation3D::kZX,
   kZY = Rotation3D::kZY,
   kZZ = Rotation3D::kZZ
};
 
// ----------------------------------------------------------------------
void convert(Rotation3D const &from, AxisAngle &to)
{
   // conversions from Rotation3D
   double m[9];
   from.GetComponents(m, m + 9);
 
   const double uZ = m[kYX] - m[kXY];
   const double uY = m[kXZ] - m[kZX];
   const double uX = m[kZY] - m[kYZ];
 
   // in case of rotation of an angle PI, the rotation matrix is symmetric and
   // uX = uY = uZ  = 0. Use then conversion through the quaternion
   if (math_fabs(uX) < 8. * std::numeric_limits<double>::epsilon() &&
       math_fabs(uY) < 8. * std::numeric_limits<double>::epsilon() &&
       math_fabs(uZ) < 8. * std::numeric_limits<double>::epsilon()) {
      Quaternion tmp;
      convert(from, tmp);
      convert(tmp, to);
      return;
   }
 
   AxisAngle::AxisVector u;
 
   u.SetCoordinates(uX, uY, uZ);
 
   static const double pi = M_PI;
 
   double angle;
   const double cosdelta = (m[kXX] + m[kYY] + m[kZZ] - 1.0) / 2.0;
   if (cosdelta > 1.0) {
      angle = 0;
   } else if (cosdelta < -1.0) {
      angle = pi;
   } else {
      angle = math_acos(cosdelta);
   }
 
   // to.SetAngle(angle);
   to.SetComponents(u, angle);
   to.Rectify();
 
} // convert to AxisAngle
 
static void correctByPi(double &psi, double &phi)
{
   static const double pi = M_PI;
   if (psi > 0) {
      psi -= pi;
   } else {
      psi += pi;
   }
   if (phi > 0) {
      phi -= pi;
   } else {
      phi += pi;
   }
}
 
void convert(Rotation3D const &from, EulerAngles &to)
{
   // conversion from Rotation3D to Euler Angles
 
   double r[9];
   from.GetComponents(r, r + 9);
 
   double phi, theta, psi;
   double psiPlusPhi, psiMinusPhi;
   static const double pi = M_PI;
   static const double pi_2 = M_PI_2;
 
   theta = (math_fabs(r[kZZ]) <= 1.0) ? math_acos(r[kZZ]) : (r[kZZ] > 0.0) ? 0 : pi;
 
   double cosTheta = r[kZZ];
   if (cosTheta > 1)
      cosTheta = 1;
   if (cosTheta < -1)
      cosTheta = -1;
 
   // Compute psi +/- phi:
   // Depending on whether cosTheta is positive or negative and whether it
   // is less than 1 in absolute value, different mathematically equivalent
   // expressions are numerically stable.
   if (cosTheta == 1) {
      psiPlusPhi = math_atan2(r[kXY] - r[kYX], r[kXX] + r[kYY]);
      psiMinusPhi = 0;
   } else if (cosTheta >= 0) {
      psiPlusPhi = math_atan2(r[kXY] - r[kYX], r[kXX] + r[kYY]);
      double s = -r[kXY] - r[kYX]; // sin (psi-phi) * (1 - cos theta)
      double c = r[kXX] - r[kYY];  // cos (psi-phi) * (1 - cos theta)
      psiMinusPhi = math_atan2(s, c);
   } else if (cosTheta > -1) {
      psiMinusPhi = math_atan2(-r[kXY] - r[kYX], r[kXX] - r[kYY]);
      double s = r[kXY] - r[kYX]; // sin (psi+phi) * (1 + cos theta)
      double c = r[kXX] + r[kYY]; // cos (psi+phi) * (1 + cos theta)
      psiPlusPhi = math_atan2(s, c);
   } else { // cosTheta == -1
      psiMinusPhi = math_atan2(-r[kXY] - r[kYX], r[kXX] - r[kYY]);
      psiPlusPhi = 0;
   }
 
   psi = .5 * (psiPlusPhi + psiMinusPhi);
   phi = .5 * (psiPlusPhi - psiMinusPhi);
 
   // Now correct by pi if we have managed to get a value of psiPlusPhi
   // or psiMinusPhi that was off by 2 pi:
 
   // set up w[i], all of which would be positive if sin and cosine of
   // psi and phi were positive:
   double w[4];
   w[0] = r[kXZ];
   w[1] = r[kZX];
   w[2] = r[kYZ];
   w[3] = -r[kZY];
 
   // find biggest relevant term, which is the best one to use in correcting.
   double maxw = math_fabs(w[0]);
   int imax = 0;
   for (int i = 1; i < 4; ++i) {
      if (math_fabs(w[i]) > maxw) {
         maxw = math_fabs(w[i]);
         imax = i;
      }
   }
   // Determine if the correction needs to be applied:  The criteria are
   // different depending on whether a sine or cosine was the determinor:
   switch (imax) {
   case 0:
      if (w[0] > 0 && psi < 0)
         correctByPi(psi, phi);
      if (w[0] < 0 && psi > 0)
         correctByPi(psi, phi);
      break;
   case 1:
      if (w[1] > 0 && phi < 0)
         correctByPi(psi, phi);
      if (w[1] < 0 && phi > 0)
         correctByPi(psi, phi);
      break;
   case 2:
      if (w[2] > 0 && math_fabs(psi) > pi_2)
         correctByPi(psi, phi);
      if (w[2] < 0 && math_fabs(psi) < pi_2)
         correctByPi(psi, phi);
      break;
   case 3:
      if (w[3] > 0 && math_fabs(phi) > pi_2)
         correctByPi(psi, phi);
      if (w[3] < 0 && math_fabs(phi) < pi_2)
         correctByPi(psi, phi);
      break;
   }
 
   to.SetComponents(phi, theta, psi);
 
} // convert to EulerAngles
 
////////////////////////////////////////////////////////////////////////////////
/// conversion from Rotation3D to Quaternion
 
void convert(Rotation3D const &from, Quaternion &to)
{
   double m[9];
   from.GetComponents(m, m + 9);
 
   const double d0 = m[kXX] + m[kYY] + m[kZZ];
   const double d1 = +m[kXX] - m[kYY] - m[kZZ];
   const double d2 = -m[kXX] + m[kYY] - m[kZZ];
   const double d3 = -m[kXX] - m[kYY] + m[kZZ];
 
   // these are related to the various q^2 values;
   // choose the largest to avoid dividing two small numbers and losing accuracy.
 
   if (d0 >= d1 && d0 >= d2 && d0 >= d3) {
      const double q0 = .5 * math_sqrt(1 + d0);
      const double f = .25 / q0;
      const double q1 = f * (m[kZY] - m[kYZ]);
      const double q2 = f * (m[kXZ] - m[kZX]);
      const double q3 = f * (m[kYX] - m[kXY]);
      to.SetComponents(q0, q1, q2, q3);
      to.Rectify();
      return;
   } else if (d1 >= d2 && d1 >= d3) {
      const double q1 = .5 * math_sqrt(1 + d1);
      const double f = .25 / q1;
      const double q0 = f * (m[kZY] - m[kYZ]);
      const double q2 = f * (m[kXY] + m[kYX]);
      const double q3 = f * (m[kXZ] + m[kZX]);
      to.SetComponents(q0, q1, q2, q3);
      to.Rectify();
      return;
   } else if (d2 >= d3) {
      const double q2 = .5 * math_sqrt(1 + d2);
      const double f = .25 / q2;
      const double q0 = f * (m[kXZ] - m[kZX]);
      const double q1 = f * (m[kXY] + m[kYX]);
      const double q3 = f * (m[kYZ] + m[kZY]);
      to.SetComponents(q0, q1, q2, q3);
      to.Rectify();
      return;
   } else {
      const double q3 = .5 * math_sqrt(1 + d3);
      const double f = .25 / q3;
      const double q0 = f * (m[kYX] - m[kXY]);
      const double q1 = f * (m[kXZ] + m[kZX]);
      const double q2 = f * (m[kYZ] + m[kZY]);
      to.SetComponents(q0, q1, q2, q3);
      to.Rectify();
      return;
   }
} // convert to Quaternion
 
////////////////////////////////////////////////////////////////////////////////
/// conversion from Rotation3D to RotationZYX
/// same Math used as for EulerAngles apart from some different meaning of angles and
/// matrix elements.
 
void convert(Rotation3D const &from, RotationZYX &to)
{
   // theta is assumed to be in range [-PI/2,PI/2].
   // this is guaranteed by the Rectify function
 
   static const double pi_2 = M_PI_2;
 
   double r[9];
   from.GetComponents(r, r + 9);
 
   double phi, theta, psi = 0;
 
   // careful for numeical error make sin(theta) ourtside [-1,1]
   double sinTheta = r[kXZ];
   if (sinTheta < -1.0)
      sinTheta = -1.0;
   if (sinTheta > 1.0)
      sinTheta = 1.0;
   theta = math_asin(sinTheta);
 
   // compute psi +/- phi
   // Depending on whether cosTheta is positive or negative and whether it
   // is less than 1 in absolute value, different mathematically equivalent
   // expressions are numerically stable.
   // algorithm from
   // adapted for the case 3-2-1
 
   double psiPlusPhi = 0;
   double psiMinusPhi = 0;
 
   // valid if sinTheta not eq to -1 otherwise is zero
   if (sinTheta > -1.0)
      psiPlusPhi = atan2(r[kYX] + r[kZY], r[kYY] - r[kZX]);
 
   // valid if sinTheta not eq. to 1
   if (sinTheta < 1.0)
      psiMinusPhi = atan2(r[kZY] - r[kYX], r[kYY] + r[kZX]);
 
   psi = .5 * (psiPlusPhi + psiMinusPhi);
   phi = .5 * (psiPlusPhi - psiMinusPhi);
 
   // correction is not necessary if sinTheta = +/- 1
   // if (sinTheta == 1.0 || sinTheta == -1.0) return;
 
   // apply the corrections according to max of the other terms
   // I think is assumed convention that theta is between -PI/2,PI/2.
   // OTHERWISE RESULT MIGHT BE DIFFERENT ???
 
   // since we determine phi+psi or phi-psi phi and psi can be both have a shift of +/- PI.
   //  The shift must be applied on both (the sum (or difference) is knows to +/- 2PI )
   // This can be fixed looking at the other 4 matrix terms, which have terms in sin and cos of psi
   //  and phi. sin(psi+/-PI) = -sin(psi) and cos(psi+/-PI) = -cos(psi).
   // Use then the biggest term for making the correction to minimize possible numerical errors
 
   // set up w[i], all of which would be positive if sin and cosine of
   // psi and phi were positive:
   double w[4];
   w[0] = -r[kYZ];
   w[1] = -r[kXY];
   w[2] = r[kZZ];
   w[3] = r[kXX];
 
   // find biggest relevant term, which is the best one to use in correcting.
   double maxw = math_fabs(w[0]);
   int imax = 0;
   for (int i = 1; i < 4; ++i) {
      if (math_fabs(w[i]) > maxw) {
         maxw = math_fabs(w[i]);
         imax = i;
      }
   }
 
   // Determine if the correction needs to be applied:  The criteria are
   // different depending on whether a sine or cosine was the determinor:
   switch (imax) {
   case 0:
      if (w[0] > 0 && psi < 0)
         correctByPi(psi, phi);
      if (w[0] < 0 && psi > 0)
         correctByPi(psi, phi);
      break;
   case 1:
      if (w[1] > 0 && phi < 0)
         correctByPi(psi, phi);
      if (w[1] < 0 && phi > 0)
         correctByPi(psi, phi);
      break;
   case 2:
      if (w[2] > 0 && math_fabs(psi) > pi_2)
         correctByPi(psi, phi);
      if (w[2] < 0 && math_fabs(psi) < pi_2)
         correctByPi(psi, phi);
      break;
   case 3:
      if (w[3] > 0 && math_fabs(phi) > pi_2)
         correctByPi(psi, phi);
      if (w[3] < 0 && math_fabs(phi) < pi_2)
         correctByPi(psi, phi);
      break;
   }
 
   to.SetComponents(phi, theta, psi);
 
} // convert to RotationZYX
 
// ----------------------------------------------------------------------
// conversions from AxisAngle
 
void convert(AxisAngle const &from, Rotation3D &to)
{
   // conversion from AxisAngle to Rotation3D
 
   const double sinDelta = math_sin(from.Angle());
   const double cosDelta = math_cos(from.Angle());
   const double oneMinusCosDelta = 1.0 - cosDelta;
 
   const AxisAngle::AxisVector &u = from.Axis();
   const double uX = u.X();
   const double uY = u.Y();
   const double uZ = u.Z();
 
   double m[9];
 
   m[kXX] = oneMinusCosDelta * uX * uX + cosDelta;
   m[kXY] = oneMinusCosDelta * uX * uY - sinDelta * uZ;
   m[kXZ] = oneMinusCosDelta * uX * uZ + sinDelta * uY;
 
   m[kYX] = oneMinusCosDelta * uY * uX + sinDelta * uZ;
   m[kYY] = oneMinusCosDelta * uY * uY + cosDelta;
   m[kYZ] = oneMinusCosDelta * uY * uZ - sinDelta * uX;
 
   m[kZX] = oneMinusCosDelta * uZ * uX - sinDelta * uY;
   m[kZY] = oneMinusCosDelta * uZ * uY + sinDelta * uX;
   m[kZZ] = oneMinusCosDelta * uZ * uZ + cosDelta;
 
   to.SetComponents(m, m + 9);
} // convert to Rotation3D
 
void convert(AxisAngle const &from, EulerAngles &to)
{
   // conversion from AxisAngle to EulerAngles
   // TODO better : temporary make conversion using  Rotation3D
 
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
void convert(AxisAngle const &from, Quaternion &to)
{
   // conversion from AxisAngle to Quaternion
 
   double s = math_sin(from.Angle() / 2);
   DisplacementVector3D<Cartesian3D<double>> axis = from.Axis();
 
   to.SetComponents(math_cos(from.Angle() / 2), s * axis.X(), s * axis.Y(), s * axis.Z());
} // convert to Quaternion
 
void convert(AxisAngle const &from, RotationZYX &to)
{
   // conversion from AxisAngle to RotationZYX
   // TODO better : temporary make conversion using  Rotation3D
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
// ----------------------------------------------------------------------
// conversions from EulerAngles
 
void convert(EulerAngles const &from, Rotation3D &to)
{
   // conversion from EulerAngles to Rotation3D
 
   typedef double Scalar;
   const Scalar sPhi = math_sin(from.Phi());
   const Scalar cPhi = math_cos(from.Phi());
   const Scalar sTheta = math_sin(from.Theta());
   const Scalar cTheta = math_cos(from.Theta());
   const Scalar sPsi = math_sin(from.Psi());
   const Scalar cPsi = math_cos(from.Psi());
   to.SetComponents(cPsi * cPhi - sPsi * cTheta * sPhi, cPsi * sPhi + sPsi * cTheta * cPhi, sPsi * sTheta,
                    -sPsi * cPhi - cPsi * cTheta * sPhi, -sPsi * sPhi + cPsi * cTheta * cPhi, cPsi * sTheta,
                    sTheta * sPhi, -sTheta * cPhi, cTheta);
}
 
void convert(EulerAngles const &from, AxisAngle &to)
{
   // conversion from EulerAngles to AxisAngle
   // make converting first to quaternion
   Quaternion q;
   convert(from, q);
   convert(q, to);
}
 
void convert(EulerAngles const &from, Quaternion &to)
{
   // conversion from EulerAngles to Quaternion
 
   typedef double Scalar;
   const Scalar plus = (from.Phi() + from.Psi()) / 2;
   const Scalar minus = (from.Phi() - from.Psi()) / 2;
   const Scalar sPlus = math_sin(plus);
   const Scalar cPlus = math_cos(plus);
   const Scalar sMinus = math_sin(minus);
   const Scalar cMinus = math_cos(minus);
   const Scalar sTheta = math_sin(from.Theta() / 2);
   const Scalar cTheta = math_cos(from.Theta() / 2);
 
   to.SetComponents(cTheta * cPlus, -sTheta * cMinus, -sTheta * sMinus, -cTheta * sPlus);
   // TODO -- carefully check that this is correct
}
 
void convert(EulerAngles const &from, RotationZYX &to)
{
   // conversion from EulerAngles to RotationZYX
   // TODO better : temporary make conversion using  Rotation3D
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
// ----------------------------------------------------------------------
// conversions from Quaternion
 
void convert(Quaternion const &from, Rotation3D &to)
{
   // conversion from Quaternion to Rotation3D
 
   const double q0 = from.U();
   const double q1 = from.I();
   const double q2 = from.J();
   const double q3 = from.K();
   const double q00 = q0 * q0;
   const double q01 = q0 * q1;
   const double q02 = q0 * q2;
   const double q03 = q0 * q3;
   const double q11 = q1 * q1;
   const double q12 = q1 * q2;
   const double q13 = q1 * q3;
   const double q22 = q2 * q2;
   const double q23 = q2 * q3;
   const double q33 = q3 * q3;
 
   to.SetComponents(q00 + q11 - q22 - q33, 2 * (q12 - q03), 2 * (q02 + q13), 2 * (q12 + q03), q00 - q11 + q22 - q33,
                    2 * (q23 - q01), 2 * (q13 - q02), 2 * (q23 + q01), q00 - q11 - q22 + q33);
 
} // conversion to Rotation3D
 
void convert(Quaternion const &from, AxisAngle &to)
{
   // conversion from Quaternion to AxisAngle
 
   double u = from.U();
   if (u >= 0) {
      if (u > 1)
         u = 1;
      const double angle = 2.0 * math_acos(from.U());
      DisplacementVector3D<Cartesian3D<double>> axis(from.I(), from.J(), from.K());
      to.SetComponents(axis, angle);
   } else {
      if (u < -1)
         u = -1;
      const double angle = 2.0 * math_acos(-from.U());
      DisplacementVector3D<Cartesian3D<double>> axis(-from.I(), -from.J(), -from.K());
      to.SetComponents(axis, angle);
   }
} // conversion to AxisAngle
 
void convert(Quaternion const &from, EulerAngles &to)
{
   // conversion from Quaternion to EulerAngles
   // TODO better
   // temporary make conversion using  Rotation3D
 
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
void convert(Quaternion const &from, RotationZYX &to)
{
   // conversion from Quaternion to RotationZYX
   // TODO better : temporary make conversion using  Rotation3D
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
// ----------------------------------------------------------------------
// conversions from RotationZYX
void convert(RotationZYX const &from, Rotation3D &to)
{
   // conversion to Rotation3D (matrix)
 
   double phi, theta, psi = 0;
   from.GetComponents(phi, theta, psi);
   to.SetComponents(
      math_cos(theta) * math_cos(phi), -math_cos(theta) * math_sin(phi), math_sin(theta),
 
      math_cos(psi) * math_sin(phi) + math_sin(psi) * math_sin(theta) * math_cos(phi),
      math_cos(psi) * math_cos(phi) - math_sin(psi) * math_sin(theta) * math_sin(phi), -math_sin(psi) * math_cos(theta),
 
      math_sin(psi) * math_sin(phi) - math_cos(psi) * math_sin(theta) * math_cos(phi),
      math_sin(psi) * math_cos(phi) + math_cos(psi) * math_sin(theta) * math_sin(phi), math_cos(psi) * math_cos(theta));
}
void convert(RotationZYX const &from, AxisAngle &to)
{
   // conversion to axis angle
   // TODO better : temporary make conversion using  Rotation3D
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
void convert(RotationZYX const &from, EulerAngles &to)
{
   // conversion to Euler angle
   // TODO better : temporary make conversion using  Rotation3D
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
void convert(RotationZYX const &from, Quaternion &to)
{
   double phi, theta, psi = 0;
   from.GetComponents(phi, theta, psi);
 
   double sphi2 = math_sin(phi / 2);
   double cphi2 = math_cos(phi / 2);
   double stheta2 = math_sin(theta / 2);
   double ctheta2 = math_cos(theta / 2);
   double spsi2 = math_sin(psi / 2);
   double cpsi2 = math_cos(psi / 2);
   to.SetComponents(
      cphi2 * cpsi2 * ctheta2 - sphi2 * spsi2 * stheta2, sphi2 * cpsi2 * stheta2 + cphi2 * spsi2 * ctheta2,
      cphi2 * cpsi2 * stheta2 - sphi2 * spsi2 * ctheta2, sphi2 * cpsi2 * ctheta2 + cphi2 * spsi2 * stheta2);
}
 
// ----------------------------------------------------------------------
// conversions from RotationX
 
void convert(RotationX const &from, Rotation3D &to)
{
   // conversion from RotationX to Rotation3D
 
   const double c = from.CosAngle();
   const double s = from.SinAngle();
   to.SetComponents(1, 0, 0, 0, c, -s, 0, s, c);
}
 
void convert(RotationX const &from, AxisAngle &to)
{
   // conversion from RotationX to AxisAngle
 
   DisplacementVector3D<Cartesian3D<double>> axis(1, 0, 0);
   to.SetComponents(axis, from.Angle());
}
 
void convert(RotationX const &from, EulerAngles &to)
{
   // conversion from RotationX to EulerAngles
   // TODO better: temporary make conversion using  Rotation3D
 
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
void convert(RotationX const &from, Quaternion &to)
{
   // conversion from RotationX to Quaternion
 
   to.SetComponents(math_cos(from.Angle() / 2), math_sin(from.Angle() / 2), 0, 0);
}
 
void convert(RotationX const &from, RotationZYX &to)
{
   // conversion from RotationX to RotationZYX
   to.SetComponents(0, 0, from.Angle());
}
 
// ----------------------------------------------------------------------
// conversions from RotationY
 
void convert(RotationY const &from, Rotation3D &to)
{
   // conversion from RotationY to Rotation3D
 
   const double c = from.CosAngle();
   const double s = from.SinAngle();
   to.SetComponents(c, 0, s, 0, 1, 0, -s, 0, c);
}
 
void convert(RotationY const &from, AxisAngle &to)
{
   // conversion from RotationY to AxisAngle
 
   DisplacementVector3D<Cartesian3D<double>> axis(0, 1, 0);
   to.SetComponents(axis, from.Angle());
}
 
void convert(RotationY const &from, EulerAngles &to)
{
   // conversion from RotationY to EulerAngles
   // TODO better: temporary make conversion using  Rotation3D
 
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
void convert(RotationY const &from, RotationZYX &to)
{
   // conversion from RotationY to RotationZYX
   to.SetComponents(0, from.Angle(), 0);
}
 
void convert(RotationY const &from, Quaternion &to)
{
   // conversion from RotationY to Quaternion
 
   to.SetComponents(math_cos(from.Angle() / 2), 0, math_sin(from.Angle() / 2), 0);
}
 
// ----------------------------------------------------------------------
// conversions from RotationZ
 
void convert(RotationZ const &from, Rotation3D &to)
{
   // conversion from RotationZ to Rotation3D
 
   const double c = from.CosAngle();
   const double s = from.SinAngle();
   to.SetComponents(c, -s, 0, s, c, 0, 0, 0, 1);
}
 
void convert(RotationZ const &from, AxisAngle &to)
{
   // conversion from RotationZ to AxisAngle
 
   DisplacementVector3D<Cartesian3D<double>> axis(0, 0, 1);
   to.SetComponents(axis, from.Angle());
}
 
void convert(RotationZ const &from, EulerAngles &to)
{
   // conversion from RotationZ to EulerAngles
   // TODO better: temporary make conversion using  Rotation3D
 
   Rotation3D tmp;
   convert(from, tmp);
   convert(tmp, to);
}
 
void convert(RotationZ const &from, RotationZYX &to)
{
   // conversion from RotationY to RotationZYX
   to.SetComponents(from.Angle(), 0, 0);
}
 
void convert(RotationZ const &from, Quaternion &to)
{
   // conversion from RotationZ to Quaternion
 
   to.SetComponents(math_cos(from.Angle() / 2), 0, 0, math_sin(from.Angle() / 2));
}
 
} // namespace gv_detail
} // namespace ROOT_MATH_ARCH
} // namespace ROOT