rasterize/detail/SafetyCalculator.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 geocel/rasterize/detail/SafetyCalculator.hh
0006 //---------------------------------------------------------------------------//
0007 #pragma once
0008
0009 #include "corecel/math/Algorithms.hh"
0010 #include "corecel/math/ArrayUtils.hh"
0011 #include "corecel/math/NumericLimits.hh"
0012
0013 #include "../ImageData.hh"
0014
0015 namespace celeritas
0016 {
0017 namespace detail
0018 {
0019 //---------------------------------------------------------------------------//
0020 /*!
0021  * Calculate the safety distance at an x,y position.
0022  *
0023  * The direction of the initialized state is "out of the page". The maximum
0024  * distance should generally be the length scale of the image.
0025  */
0026 template<class GTV>
0027 class SafetyCalculator
0028 {
0029   public:
0030     //!@{
0031     //! \name Type aliases
0032     using ParamsRef = NativeCRef<ImageParamsData>;
0033     using StateRef = NativeRef<ImageStateData>;
0034     //!@}
0035
0036   public:
0037     // Construct with geo track view
0038     inline CELER_FUNCTION
0039     SafetyCalculator(GTV&&, ParamsRef const&, real_type max_distance);
0040
0041     // Calculate safety at an x, y index
0042     inline CELER_FUNCTION real_type operator()(size_type x, size_type y);
0043
0044   private:
0045     GTV geo_;
0046     ImageParamsScalars const& scalars_;
0047     Real3 dir_;
0048     real_type max_distance_;
0049 };
0050
0051 //---------------------------------------------------------------------------//
0052 // DEDUCTION GUIDES
0053 //---------------------------------------------------------------------------//
0054
0055 template<class GTV>
0056 CELER_FUNCTION SafetyCalculator(GTV&&,
0057                                 NativeCRef<ImageParamsData> const&,
0058                                 real_type) -> SafetyCalculator<GTV>;
0059
0060 //---------------------------------------------------------------------------//
0061 // INLINE DEFINITIONS
0062 //---------------------------------------------------------------------------//
0063 /*!
0064  * Construct with geo track view.
0065  */
0066 template<class GTV>
0067 CELER_FUNCTION SafetyCalculator<GTV>::SafetyCalculator(GTV&& geo,
0068                                                        ParamsRef const& params,
0069                                                        real_type max_distance)
0070     : geo_{celeritas::forward<GTV>(geo)}
0071     , scalars_{params.scalars}
0072     , dir_{make_unit_vector(cross_product(scalars_.down, scalars_.right))}
0073     , max_distance_{max_distance}
0074 {
0075     CELER_ENSURE(max_distance_ > 0);
0076 }
0077
0078 //---------------------------------------------------------------------------//
0079 /*!
0080  * Calculate safety at an x, y coordinate.
0081  */
0082 template<class GTV>
0083 CELER_FUNCTION real_type SafetyCalculator<GTV>::operator()(size_type x,
0084                                                            size_type y)
0085 {
0086     geo_ = [&] {
0087         auto calc_offset = [pw = scalars_.pixel_width](size_type i) {
0088             return pw * (static_cast<real_type>(i) + real_type(0.5));
0089         };
0090
0091         GeoTrackInitializer init;
0092         init.pos = scalars_.origin;
0093         axpy(calc_offset(y), scalars_.down, &init.pos);
0094         axpy(calc_offset(x), scalars_.right, &init.pos);
0095         init.dir = dir_;
0096         return init;
0097     }();
0098
0099     if (geo_.is_outside())
0100     {
0101         return numeric_limits<real_type>::quiet_NaN();
0102     }
0103
0104     return geo_.find_safety(max_distance_);
0105 }
0106
0107 //---------------------------------------------------------------------------//
0108 }  // namespace detail
0109 }  // namespace celeritas