transform/detail/TransformTranslator.hh

0001 //----------------------------------*-C++-*----------------------------------//
0002 // Copyright 2023-2024 UT-Battelle, LLC, and other Celeritas developers.
0003 // See the top-level COPYRIGHT file for details.
0004 // SPDX-License-Identifier: (Apache-2.0 OR MIT)
0005 //---------------------------------------------------------------------------//
0006 //! \file orange/transform/detail/TransformTranslator.hh
0007 //---------------------------------------------------------------------------//
0008 #pragma once
0009
0010 #include "corecel/math/ArrayOperators.hh"
0011 #include "geocel/Types.hh"
0012 #include "orange/MatrixUtils.hh"
0013
0014 #include "../NoTransformation.hh"
0015 #include "../Transformation.hh"
0016 #include "../Translation.hh"
0017
0018 namespace celeritas
0019 {
0020 namespace detail
0021 {
0022 //---------------------------------------------------------------------------//
0023 /*!
0024  * Apply a translation to a transform to get another transform.
0025  *
0026  * An instance of this class applies a daughter-to-parent translation to
0027  * another transformation: the translation needed to relocate a "lower"
0028  * universe to a new coordinate system in the "higher" universe.
0029  *
0030  * Given a transform operator \b T defined \f[
0031    \mathbf{T} x = \mathbf{R} x + t
0032  * \f]
0033  * and a translation operator defined \f[
0034    \mathbf{\tilde T} x = x + t
0035  * \f]
0036  * where \f$ \mathbf{R} = \mathbf{I} \f$ is the implicit rotation matrix for
0037  * a translation, this operation returns a new transform
0038  * \f[
0039    \mathbf{T}' = \mathbf{\tilde T}_A \mathbf{T}_B
0040  * \f]
0041  * where \f$\mathbf{\tilde T}_A\f$ is the constructor argument, \b T_B is the
0042  argument passed to the call operator,
0043  * and the \f$\mathbf{T}'\f$ is the return value.
0044  * The resulting transform has rotation
0045  * \f[
0046    \mathbf{R}' = \mathbf{R}_B
0047  * \f]
0048  * and translation
0049  * \f[
0050    \mathbf{t}' = \mathbf{t}_B + \mathbf{t}_A
0051  * \f]
0052  */
0053 class TransformTranslator
0054 {
0055   public:
0056     //@{
0057     //! \name Type aliases
0058     using Mat3 = SquareMatrixReal3;
0059     //@}
0060
0061   public:
0062     //! Construct with the new reference frame of the translation
0063     explicit TransformTranslator(Translation const& tr) : tr_{tr} {}
0064
0065     //// TRANSFORMATIONS ////
0066
0067     //! Transform an identity
0068     Translation const& operator()(NoTransformation const&) const
0069     {
0070         return tr_;
0071     }
0072
0073     inline Transformation operator()(Mat3 const&) const;
0074
0075     inline Transformation operator()(Transformation const&) const;
0076
0077     inline Translation operator()(Translation const&) const;
0078
0079   private:
0080     Translation tr_;
0081 };
0082
0083 //---------------------------------------------------------------------------//
0084 /*!
0085  * Apply a translation to a rotation matrix.
0086  */
0087 Transformation TransformTranslator::operator()(Mat3 const& rot) const
0088 {
0089     return Transformation{rot, tr_.translation()};
0090 }
0091
0092 //---------------------------------------------------------------------------//
0093 /*!
0094  * Apply a translation to a transform.
0095  */
0096 Transformation TransformTranslator::operator()(Transformation const& tr) const
0097 {
0098     return Transformation{tr.rotation(), tr.translation() + tr_.translation()};
0099 }
0100
0101 //---------------------------------------------------------------------------//
0102 /*!
0103  * Apply a translation to another translation.
0104  */
0105 Translation TransformTranslator::operator()(Translation const& tl) const
0106 {
0107     return Translation{tl.translation() + tr_.translation()};
0108 }
0109
0110 //---------------------------------------------------------------------------//
0111 }  // namespace detail
0112 }  // namespace celeritas