surf/detail/RecursiveSimplifierImpl.hh

0001 //------------------------------- -*- C++ -*- -------------------------------//
0002 // Copyright Celeritas contributors: see top-level COPYRIGHT file for details
0003 // SPDX-License-Identifier: (Apache-2.0 OR MIT)
0004 //---------------------------------------------------------------------------//
0005 //! \file orange/surf/detail/RecursiveSimplifierImpl.hh
0006 //---------------------------------------------------------------------------//
0007 #pragma once
0008
0009 #include <variant>
0010
0011 #include "corecel/Macros.hh"
0012 #include "orange/OrangeTypes.hh"
0013
0014 #include "../SurfaceSimplifier.hh"
0015
0016 namespace celeritas
0017 {
0018 namespace detail
0019 {
0020 //---------------------------------------------------------------------------//
0021 /*!
0022  * Recursively simplify, then call the given function on the final surface.
0023  *
0024  * This implementation class allows std::visit to be used with the surface
0025  * while retaining updates to the associated Sense that the user requested.
0026  */
0027 template<class F>
0028 class RecursiveSimplifierImpl
0029 {
0030   public:
0031     //! Construct with reference to function and values to be used
0032     RecursiveSimplifierImpl(F& func, Sense sense, real_type abs_tol)
0033         : func_{func}, sense_{sense}, simplify_{&sense_, abs_tol}
0034     {
0035     }
0036
0037     //! Invoke recursively with a specific surface type
0038     template<class S>
0039     void operator()(S const& surf)
0040     {
0041         auto result = simplify_(surf);
0042         CELER_ASSUME(!result.valueless_by_exception());
0043         if (std::holds_alternative<std::monostate>(result))
0044         {
0045             // Could not simplify further: call back with sense and surface
0046             return func_(sense_, surf);
0047         }
0048         else
0049         {
0050             return std::visit(*this, result);
0051         }
0052     }
0053
0054     //! Monostate should never be reached
0055     void operator()(std::monostate) { CELER_ASSERT_UNREACHABLE(); }
0056
0057   private:
0058     F& func_;
0059     Sense sense_;
0060     SurfaceSimplifier simplify_;
0061 };
0062
0063 //---------------------------------------------------------------------------//
0064 }  // namespace detail
0065 }  // namespace celeritas