celeritas/field/LinearPropagator.hh

0001 //---------------------------------*-C++-*-----------------------------------//
0002 // Copyright 2020-2024 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 celeritas/field/LinearPropagator.hh
0007 //---------------------------------------------------------------------------//
0008 #pragma once
0009
0010 #include "corecel/math/Algorithms.hh"
0011 #include "geocel/Types.hh"
0012
0013 namespace celeritas
0014 {
0015 //---------------------------------------------------------------------------//
0016 /*!
0017  * Propagate (move) a particle in a straight line.
0018  */
0019 template<class GTV>
0020 class LinearPropagator
0021 {
0022   public:
0023     //!@{
0024     //! \name Type aliases
0025     using result_type = Propagation;
0026     //!@}
0027
0028   public:
0029     //! Construct from a geo track view
0030     CELER_FUNCTION LinearPropagator(GTV&& track)
0031         : geo_(::celeritas::forward<GTV>(track))
0032     {
0033     }
0034
0035     // Move track to next volume boundary.
0036     inline CELER_FUNCTION result_type operator()();
0037
0038     // Move track up to a user-provided distance, up to the next boundary
0039     inline CELER_FUNCTION result_type operator()(real_type dist);
0040
0041     //! Whether it's possible to have tracks that are looping
0042     static CELER_CONSTEXPR_FUNCTION bool tracks_can_loop() { return false; }
0043
0044   private:
0045     GTV geo_;
0046 };
0047
0048 //---------------------------------------------------------------------------//
0049 // DEDUCTION GUIDES
0050 //---------------------------------------------------------------------------//
0051 template<class GTV>
0052 CELER_FUNCTION LinearPropagator(GTV&&) -> LinearPropagator<GTV>;
0053
0054 //---------------------------------------------------------------------------//
0055 /*!
0056  * Move track to next volume boundary.
0057  */
0058 template<class GTV>
0059 CELER_FUNCTION auto LinearPropagator<GTV>::operator()() -> result_type
0060 {
0061     CELER_EXPECT(!geo_.is_outside());
0062
0063     result_type result = geo_.find_next_step();
0064     CELER_ASSERT(result.boundary);
0065     geo_.move_to_boundary();
0066
0067     return result;
0068 }
0069
0070 //---------------------------------------------------------------------------//
0071 /*!
0072  * Move track by a user-provided distance up to the next boundary.
0073  */
0074 template<class GTV>
0075 CELER_FUNCTION auto
0076 LinearPropagator<GTV>::operator()(real_type dist) -> result_type
0077 {
0078     CELER_EXPECT(dist > 0);
0079
0080     result_type result = geo_.find_next_step(dist);
0081
0082     if (result.boundary)
0083     {
0084         geo_.move_to_boundary();
0085     }
0086     else
0087     {
0088         CELER_ASSERT(dist == result.distance);
0089         geo_.move_internal(dist);
0090     }
0091
0092     return result;
0093 }
0094
0095 //---------------------------------------------------------------------------//
0096 }  // namespace celeritas