cpu/propagator/perigee_extrapolator.cpp

0001 // This file is part of the ACTS project.
0002 //
0003 // Copyright (C) 2016 CERN for the benefit of the ACTS project
0004 //
0005 // This Source Code Form is subject to the terms of the Mozilla Public
0006 // License, v. 2.0. If a copy of the MPL was not distributed with this
0007 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
0008
0009 // Keep info log level to avoid Debug-only template paths in CI checks.
0010 #ifdef DETRAY_LOG_LVL
0011 #undef DETRAY_LOG_LVL
0012 #endif
0013 #define DETRAY_LOG_LVL 1
0014
0015 // Project include(s)
0016 #include "detray/propagator/perigee_extrapolator.hpp"
0017
0018 #include "detray/definitions/units.hpp"
0019 #include "detray/navigation/caching_navigator.hpp"
0020 #include "detray/propagator/base_actor.hpp"
0021 #include "detray/propagator/line_stepper.hpp"
0022 #include "detray/propagator/propagator.hpp"
0023 #include "detray/propagator/rk_stepper.hpp"
0024 #include "detray/tracks/tracks.hpp"
0025
0026 // Detray test include(s)
0027 #include "detray/test/common/bfield.hpp"
0028 #include "detray/test/common/build_toy_detector.hpp"
0029 #include "detray/test/common/track_generators.hpp"
0030 #include "detray/test/framework/types.hpp"
0031
0032 // Vecmem include(s)
0033 #include <vecmem/memory/host_memory_resource.hpp>
0034
0035 // GTest include(s)
0036 #include <gtest/gtest.h>
0037
0038 using namespace detray;
0039
0040 using test_algebra = test::algebra;
0041 using scalar = test::scalar;
0042 using point3 = test::point3;
0043
0044 constexpr scalar tol{1.1e-3f};
0045
0046 namespace detray::test {
0047
0048 struct portal_aborter : public base_actor {
0049   /// Exits the navigation as soon as the first portal is reached.
0050   /// @param prop_state state of the propagation
0051   template <typename propagator_state_t>
0052   DETRAY_HOST_DEVICE void operator()(propagator_state_t &prop_state) const {
0053     DETRAY_VERBOSE_HOST("Aborter: Check target surface");
0054
0055     auto &navigation = prop_state.navigation();
0056     if (navigation.is_on_portal()) {
0057       navigation.exit();
0058       prop_state.heartbeat(false);
0059     }
0060   }
0061 };
0062
0063 }  // namespace detray::test
0064
0065 /// Test the extrapolation of a track to the perigee
0066 GTEST_TEST(detray_propagator, perigee_extrapolator) {
0067   vecmem::host_memory_resource host_mr;
0068
0069   toy_det_config<scalar> toy_cfg{};
0070   toy_cfg.use_material_maps(false);
0071   const auto [d, names] = build_toy_detector<test_algebra>(host_mr, toy_cfg);
0072
0073   using detector_t = decltype(d);
0074   using stepper_t = line_stepper<test_algebra>;
0075   using actor_chain_t = actor_chain<test::portal_aborter>;
0076
0077   using propagator_t =
0078       propagator<stepper_t, caching_navigator<detector_t>, actor_chain_t>;
0079   using extrapolator_t = perigee_extrapolator<detector_t, stepper_t>;
0080
0081   // Track generator configuration
0082   using generator_t =
0083       uniform_track_generator<free_track_parameters<test_algebra>>;
0084
0085   // Track generator config
0086   generator_t::configuration trk_gen_cfg{};
0087   trk_gen_cfg.eta_range(-3.f, 3.f);
0088   trk_gen_cfg.phi_steps(50u).eta_steps(50u);
0089   trk_gen_cfg.p_tot(10.f * unit<scalar>::GeV);
0090
0091   propagation::config prop_cfg{};
0092
0093   propagator_t p{prop_cfg};
0094   const extrapolator_t pe{prop_cfg};
0095
0096   // Iterate through uniformly distributed momentum directions
0097   for (auto track : generator_t{trk_gen_cfg}) {
0098     // Propagate to first portal
0099     propagator_t::state prop_state{track, d, prop_cfg.context};
0100     ASSERT_TRUE(p.propagate(prop_state));
0101     ASSERT_TRUE(prop_state.stepping().path_length() >= 25.f * unit<scalar>::mm);
0102     ASSERT_NEAR(vector::perp(prop_state.stepping()().pos()),
0103                 25.f * unit<scalar>::mm, tol);
0104
0105     // Propagate back to perigee
0106     extrapolator_t::state extrapolator_state =
0107         pe.create_state(prop_state.stepping()(), d);
0108
0109     // Was the minimum distance to the first portal covered?
0110     ASSERT_NEAR(vector::perp(extrapolator_state.stepping()().pos()),
0111                 25.f * unit<scalar>::mm, tol);
0112
0113     // Extrapolation success?
0114     const auto bound_params = pe.extrapolate(extrapolator_state);
0115     ASSERT_TRUE(pe.finished(extrapolator_state));
0116     // Was the minimum distance to the first portal covered?
0117     EXPECT_TRUE(extrapolator_state.stepping().abs_path_length() >=
0118                 25.f * unit<scalar>::mm);
0119
0120     // Back at origin?
0121     EXPECT_NEAR(vector::norm(extrapolator_state.stepping()().pos() -
0122                              point3{0.f, 0.f, 0.f}),
0123                 0.f, tol);
0124
0125     const scalar d0{bound_params[e_bound_loc0]};
0126     const scalar z0{bound_params[e_bound_loc1]};
0127
0128     EXPECT_NEAR(d0, 0.f, tol);
0129     EXPECT_NEAR(z0, 0.f, tol);
0130   }
0131 }