alongstep/detail/TrackUpdater.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 celeritas/global/alongstep/detail/TrackUpdater.hh
0007 //---------------------------------------------------------------------------//
0008 #pragma once
0009
0010 #include "celeritas/global/CoreTrackView.hh"
0011
0012 namespace celeritas
0013 {
0014 namespace detail
0015 {
0016 //---------------------------------------------------------------------------//
0017 /*!
0018  * Finish the step.
0019  *
0020  * TODO: we may need to save the pre-step speed and apply the time update using
0021  * an average here.
0022  */
0023 //---------------------------------------------------------------------------//
0024 struct TrackUpdater
0025 {
0026     inline CELER_FUNCTION void operator()(CoreTrackView const& track);
0027 };
0028
0029 //---------------------------------------------------------------------------//
0030 // INLINE DEFINITIONS
0031 //---------------------------------------------------------------------------//
0032 CELER_FUNCTION void TrackUpdater::operator()(CoreTrackView const& track)
0033 {
0034     auto sim = track.make_sim_view();
0035
0036     // The track errored within the along-step kernel
0037     if (sim.status() == TrackStatus::errored)
0038         return;
0039
0040     if (sim.status() == TrackStatus::alive)
0041     {
0042         CELER_ASSERT(sim.step_length() > 0
0043                      || track.make_particle_view().is_stopped());
0044         CELER_ASSERT(sim.post_step_action());
0045         auto phys = track.make_physics_view();
0046         if (sim.post_step_action() != phys.scalars().discrete_action()
0047             && (!CELERITAS_DEBUG
0048                 || sim.post_step_action() != track.tracking_cut_action()))
0049         {
0050             // Reduce remaining mean free paths to travel. The 'discrete
0051             // action' case is launched separately and resets the
0052             // interaction MFP itself. In the unlikely case that a track is
0053             // about to be killed because it's looping (it's reached its
0054             // collision point but has undergone too many steps), it's OK to
0055             // set the interaction MFP to zero (but avoid during debug mode due
0056             // to the additional error checking).
0057             auto step = track.make_physics_step_view();
0058             real_type mfp = phys.interaction_mfp()
0059                             - sim.step_length() * step.macro_xs();
0060             CELER_ASSERT(mfp > 0);
0061             phys.interaction_mfp(mfp);
0062         }
0063     }
0064
0065     // Increment the step counter
0066     sim.increment_num_steps();
0067 }
0068
0069 //---------------------------------------------------------------------------//
0070 }  // namespace detail
0071 }  // namespace celeritas