celeritas/optical/Interaction.hh

0001 //----------------------------------*-C++-*----------------------------------//
0002 // Copyright 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/optical/Interaction.hh
0007 //---------------------------------------------------------------------------//
0008 #pragma once
0009
0010 #include "corecel/Macros.hh"
0011 #include "geocel/Types.hh"
0012
0013 namespace celeritas
0014 {
0015 namespace optical
0016 {
0017 //---------------------------------------------------------------------------//
0018 /*!
0019  * The result of a discrete optical interaction.
0020  *
0021  * All optical interactions are discrete. The wavelength of a photon is only
0022  * changed through absorption re-emission processes.
0023  */
0024 struct Interaction
0025 {
0026     //! Interaction result category
0027     enum class Action
0028     {
0029         scattered,  //!< Still alive, state has changed
0030         absorbed,  //!< Absorbed by the material
0031         unchanged,  //!< No state change, no secondaries
0032     };
0033
0034     Real3 direction;  //!< Post-interaction direction
0035     Real3 polarization;  //!< Post-interaction polarization
0036     Action action{Action::scattered};  //!< Flags for interaction result
0037
0038     //! Return an interaction respresenting an absorbed process
0039     static inline CELER_FUNCTION Interaction from_absorption();
0040
0041     //! Return an interaction with no change in the track state
0042     static inline CELER_FUNCTION Interaction from_unchanged();
0043
0044     //! Whether the state changed but did not fail
0045     CELER_FUNCTION bool changed() const
0046     {
0047         return static_cast<int>(action) < static_cast<int>(Action::unchanged);
0048     }
0049 };
0050
0051 //---------------------------------------------------------------------------//
0052 // INLINE DEFINITIONS
0053 //---------------------------------------------------------------------------//
0054 /*!
0055  * Construct an interaction for an absorbed optical photon.
0056  */
0057 CELER_FUNCTION Interaction Interaction::from_absorption()
0058 {
0059     Interaction result;
0060     result.action = Action::absorbed;
0061     return result;
0062 }
0063
0064 //---------------------------------------------------------------------------//
0065 /*!
0066  * Construct an interaction for edge cases where this is no state change.
0067  */
0068 CELER_FUNCTION Interaction Interaction::from_unchanged()
0069 {
0070     Interaction result;
0071     result.action = Action::unchanged;
0072     return result;
0073 }
0074
0075 //---------------------------------------------------------------------------//
0076 }  // namespace optical
0077 }  // namespace celeritas