Adds a volume builder for homogeneous volume material and a correspon…

…ding unittest

core/include/detray/builders/detector_builder.hpp

@@ -63,13 +63,22 @@ class detector_builder {
     /// Decorate a volume builder at position @param volume_idx with more
     /// functionality
     template <class builder_t>
-    DETRAY_HOST auto decorate(dindex volume_idx)
-        -> volume_builder_interface<detector_type>* {
+    DETRAY_HOST auto decorate(dindex volume_idx) -> builder_t* {
 
         m_volumes[volume_idx] =
             std::make_unique<builder_t>(std::move(m_volumes[volume_idx]));
 
-        return m_volumes[volume_idx].get();
+        // Always works, we set it as this type in the line above
+        return dynamic_cast<builder_t*>(m_volumes[volume_idx].get());
+    }
+
+    /// Decorate a volume builder @param v_builder with more functionality
+    template <class builder_t>
+    DETRAY_HOST auto decorate(
+        const volume_builder_interface<detector_type>* v_builder)
+        -> builder_t* {
+
+        return decorate<builder_t>(v_builder->vol_index());
     }
 
     /// Access a particular volume builder by volume index @param volume_idx

core/include/detray/builders/homogeneous_volume_material_builder.hpp

@@ -0,0 +1,82 @@
+/** Detray library, part of the ACTS project (R&D line)
+ *
+ * (c) 2024 CERN for the benefit of the ACTS project
+ *
+ * Mozilla Public License Version 2.0
+ */
+
+#pragma once
+
+// Project include(s).
+#include "detray/builders/volume_builder.hpp"
+#include "detray/builders/volume_builder_interface.hpp"
+#include "detray/materials/material.hpp"
+#include "detray/materials/predefined_materials.hpp"
+
+// System include(s)
+#include <iostream>
+#include <map>
+#include <memory>
+
+namespace detray {
+
+/// @brief Build a volume with homogeneous volume material.
+///
+/// Decorator class to a volume builder that adds the material data to the
+/// volume while building the volume.
+template <typename detector_t>
+class homogeneous_volume_material_builder final
+    : public volume_decorator<detector_t> {
+
+    public:
+    using scalar_type = typename detector_t::scalar_type;
+
+    /// @param vol_builder volume builder that should be decorated with volume
+    /// material
+    DETRAY_HOST
+    homogeneous_volume_material_builder(
+        std::unique_ptr<volume_builder_interface<detector_t>> vol_builder)
+        : volume_decorator<detector_t>(std::move(vol_builder)) {}
+
+    /// Add all necessary compontents for the volume material
+    ///
+    /// @param mat the material parameters
+    DETRAY_HOST
+    void set_material(material<scalar_type> mat) { m_volume_material = mat; }
+
+    /// Add the volume and the material to the detector @param det
+    DETRAY_HOST
+    auto build(detector_t &det, typename detector_t::geometry_context ctx = {})
+        -> typename detector_t::volume_type * override {
+
+        // Call the underlying volume builder(s)
+        typename detector_t::volume_type *vol =
+            volume_decorator<detector_t>::build(det, ctx);
+
+        // Nothing left to do
+        if (m_volume_material == detray::vacuum<scalar_type>{}) {
+            std::cout << "WARNING: Volume " << this->vol_index()
+                      << " has vacuum material";
+
+            return vol;
+        }
+
+        constexpr auto material_id{detector_t::materials::id::e_raw_material};
+
+        // Update the volume material link
+        dindex coll_size{det.material_store().template size<material_id>()};
+        vol->set_material(material_id, coll_size);
+
+        // Append the material
+        det.material_store().template push_back<material_id>(m_volume_material);
+
+        // Give the volume to the next decorator
+        return vol;
+    }
+
+    protected:
+    // Material for this volume
+    material<scalar_type> m_volume_material{};
+};
+
+}  // namespace detray

core/include/detray/builders/volume_builder.hpp

@@ -62,7 +62,7 @@ class volume_builder : public volume_builder_interface<detector_t> {
 
     /// @returns the volume index in the detector volume container
     DETRAY_HOST
-    auto vol_index() -> dindex override { return m_volume.index(); }
+    auto vol_index() const -> dindex override { return m_volume.index(); }
 
     /// Toggles whether sensitive surfaces are added to the brute force method
     DETRAY_HOST

core/include/detray/builders/volume_builder_interface.hpp

@@ -38,7 +38,7 @@ class volume_builder_interface {
     /// @returns the global index for the volume
     /// @note the correct index is only available after calling @c init_vol
     DETRAY_HOST
-    virtual auto vol_index() -> dindex = 0;
+    virtual auto vol_index() const -> dindex = 0;
 
     /// Toggles whether sensitive surfaces are added to the brute force method
     DETRAY_HOST
@@ -125,7 +125,7 @@ class volume_decorator : public volume_builder_interface<detector_t> {
     }
 
     DETRAY_HOST
-    auto vol_index() -> dindex override { return m_builder->vol_index(); }
+    auto vol_index() const -> dindex override { return m_builder->vol_index(); }
 
     DETRAY_HOST
     void has_accel(bool toggle) override { m_builder->has_accel(toggle); };

core/include/detray/materials/material.hpp

@@ -79,6 +79,14 @@ struct material {
                 m_z == rhs.Z());
     }
 
+    /// Equality operator
+    ///
+    /// @param rhs is the right hand side to be compared to
+    DETRAY_HOST_DEVICE
+    constexpr bool operator!=(const material<scalar_t> &rhs) const {
+        return !(*this == rhs);
+    }
+
     /// @returns the radition length. Infinity in case of vacuum.
     DETRAY_HOST_DEVICE
     constexpr scalar_type X0() const { return m_x0; }
@@ -143,10 +151,10 @@ struct material {
     DETRAY_HOST
     std::string to_string() const {
         std::stringstream strm;
-        /*if (0.f < m_ar) {
+        if (m_ar <= 0.f) {
             strm << "vacuum";
             return strm.str();
-        }*/
+        }
         strm << "material: ";
         strm << " X0: " << m_x0;
         strm << " | L0: " << m_l0;

core/include/detray/propagator/rk_stepper.hpp

@@ -93,6 +93,13 @@ class rk_stepper final
         /// Material that track is passing through. Usually a volume material
         const detray::material<scalar_type>* _mat{nullptr};
 
+        /// Access the current volume material
+        DETRAY_HOST_DEVICE
+        const auto& volume_material() const {
+            assert(_mat != nullptr);
+            return *_mat;
+        }
+
         /// Update the track state by Runge-Kutta-Nystrom integration.
         DETRAY_HOST_DEVICE
         inline void advance_track();

core/include/detray/propagator/rk_stepper.ipp

@@ -554,13 +554,13 @@ detray::rk_stepper<magnetic_field_t, transform3_t, constraint_t, policy_t,
                    inspector_t, array_t>::state::dqopds(const scalar_type qop)
     const -> typename transform3_t::scalar_type {
 
-    const auto& mat = *(this->_mat);
-
     // d(qop)ds is zero for empty space
     if (this->_mat == nullptr) {
         return 0.f;
     }
 
+    const auto& mat = this->volume_material();
+
     const auto pdg = this->_pdg;
     const scalar_type q = this->_track.charge();
     const scalar_type p = q / qop;
@@ -594,6 +594,7 @@ DETRAY_HOST_DEVICE auto detray::rk_stepper<
         return 0.f;
     }
 
+    const auto& mat = this->volume_material();
     auto& track = this->_track;
     const scalar_t q = track.charge();
     const scalar_t p = q / qop;
@@ -608,13 +609,12 @@ DETRAY_HOST_DEVICE auto detray::rk_stepper<
     // g = dE/ds = -1 * (-dE/ds) = -1 * stopping power
     const detail::relativistic_quantities<scalar_t> rq(mass, qop, q);
     // We assume that stopping power ~ mean ionization eloss per pathlength
-    const scalar_type bethe =
-        I.compute_bethe_bloch(*(this->_mat), this->_pdg, rq);
+    const scalar_type bethe = I.compute_bethe_bloch(mat, this->_pdg, rq);
     const scalar_type g = -1.f * bethe;
 
     // dg/d(qop) = -1 * derivation of stopping power
     const scalar_t dgdqop = -1.f * interaction<scalar_t>().derive_bethe_bloch(
-                                       *(this->_mat), this->_pdg, rq, bethe);
+                                       mat, this->_pdg, rq, bethe);
 
     // d(qop)/ds = - qop^3 * E * g / q^2
     const scalar_t dqopds = this->dqopds(qop);

tests/integration_tests/cpu/detectors/telescope_detector_navigation.cpp

@@ -7,7 +7,7 @@
 
 // Project include(s)
 #include "detray/definitions/units.hpp"
-#include "detray/detectors/create_telescope_detector.hpp"
+#include "detray/detectors/build_telescope_detector.hpp"
 #include "detray/test/detail/register_checks.hpp"
 #include "detray/test/detector_consistency.hpp"
 #include "detray/test/detector_helix_scan.hpp"
@@ -41,7 +41,7 @@ int main(int argc, char **argv) {
     vecmem::host_memory_resource host_mr;
 
     const auto [tel_det, tel_names] =
-        create_telescope_detector(host_mr, tel_cfg);
+        build_telescope_detector(host_mr, tel_cfg);
 
     // General data consistency of the detector
     consistency_check<tel_detector_t>::config cfg_cons{};

tests/integration_tests/cpu/material/material_interaction.cpp

@@ -9,7 +9,7 @@
 #include "detray/definitions/pdg_particle.hpp"
 #include "detray/definitions/units.hpp"
 #include "detray/detectors/bfield.hpp"
-#include "detray/detectors/create_telescope_detector.hpp"
+#include "detray/detectors/build_telescope_detector.hpp"
 #include "detray/geometry/mask.hpp"
 #include "detray/geometry/shapes/unbounded.hpp"
 #include "detray/materials/interaction.hpp"
@@ -61,7 +61,7 @@ GTEST_TEST(detray_material, telescope_geometry_energy_loss) {
         .module_material(mat)
         .mat_thickness(thickness);
 
-    const auto [det, names] = create_telescope_detector(host_mr, tel_cfg);
+    const auto [det, names] = build_telescope_detector(host_mr, tel_cfg);
 
     using navigator_t = navigator<decltype(det)>;
     using stepper_t = line_stepper<transform3>;
@@ -240,7 +240,7 @@ GTEST_TEST(detray_material, telescope_geometry_scattering_angle) {
         .module_material(mat)
         .mat_thickness(thickness);
 
-    const auto [det, names] = create_telescope_detector(host_mr, tel_cfg);
+    const auto [det, names] = build_telescope_detector(host_mr, tel_cfg);
 
     using navigator_t = navigator<decltype(det)>;
     using stepper_t = line_stepper<transform3>;
@@ -379,7 +379,7 @@ GTEST_TEST(detray_material, telescope_geometry_volume_material) {
 
     for (const auto& mat : vol_mats) {
         tel_cfg.volume_material(mat);
-        const auto [det, names] = create_telescope_detector(host_mr, tel_cfg);
+        const auto [det, names] = build_telescope_detector(host_mr, tel_cfg);
 
         using navigator_t = navigator<decltype(det)>;
         using propagator_t = propagator<stepper_t, navigator_t, actor_chain_t>;

tests/integration_tests/cpu/propagator/guided_navigator.cpp

@@ -7,7 +7,7 @@
 
 #include "detray/definitions/units.hpp"
 #include "detray/detectors/bfield.hpp"
-#include "detray/detectors/create_telescope_detector.hpp"
+#include "detray/detectors/build_telescope_detector.hpp"
 #include "detray/geometry/mask.hpp"
 #include "detray/geometry/shapes/unbounded.hpp"
 #include "detray/navigation/navigator.hpp"
@@ -46,7 +46,7 @@ GTEST_TEST(detray_navigation, guided_navigator) {
     tel_cfg.positions(positions).envelope(0.2f * unit<scalar>::mm);
 
     const auto [telescope_det, names] =
-        create_telescope_detector(host_mr, tel_cfg);
+        build_telescope_detector(host_mr, tel_cfg);
 
     // Inspectors are optional, of course
     using detector_t = decltype(telescope_det);

tests/integration_tests/cpu/propagator/jacobian_validation.cpp

@@ -8,7 +8,7 @@
 // Project include(s)
 #include "detray/definitions/units.hpp"
 #include "detray/detectors/bfield.hpp"
-#include "detray/detectors/create_telescope_detector.hpp"
+#include "detray/detectors/build_telescope_detector.hpp"
 #include "detray/navigation/intersection/helix_intersector.hpp"
 #include "detray/navigation/navigator.hpp"
 #include "detray/propagator/actors/parameter_resetter.hpp"
@@ -1657,8 +1657,9 @@ int main(int argc, char** argv) {
         }
         auto gammaF = rand_gamma(mt1);
 
+        // Without volume material
         auto [rect_det, rect_names] =
-            create_telescope_detector(host_mr, rectangle_cfg);
+            build_telescope_detector(host_mr, rectangle_cfg);
         const auto [euler_rect_initial, shift_rect_initial] =
             tilt_surface<decltype(rect_det),
                          decltype(rect_det)::masks::id::e_rectangle2>(
@@ -1672,7 +1673,7 @@ int main(int argc, char** argv) {
         // With volume material
         rectangle_cfg.volume_material(volume_mat);
         auto [rect_det_w_mat, rect_names2] =
-            create_telescope_detector(host_mr, rectangle_cfg);
+            build_telescope_detector(host_mr, rectangle_cfg);
         [[maybe_unused]] const auto [euler_rect_initial2, shift_rect_initial2] =
             tilt_surface<decltype(rect_det_w_mat),
                          decltype(rect_det_w_mat)::masks::id::e_rectangle2>(
@@ -1693,7 +1694,7 @@ int main(int argc, char** argv) {
 
         // Without volume material
         auto [wire_det, wire_names] =
-            create_telescope_detector(host_mr, wire_cfg);
+            build_telescope_detector(host_mr, wire_cfg);
         const auto [euler_wire_initial, shift_wire_initial] =
             tilt_surface<decltype(wire_det),
                          decltype(wire_det)::masks::id::e_drift_cell>(
@@ -1707,7 +1708,7 @@ int main(int argc, char** argv) {
         // With volume material
         wire_cfg.volume_material(volume_mat);
         auto [wire_det_w_mat, wire_names2] =
-            create_telescope_detector(host_mr, wire_cfg);
+            build_telescope_detector(host_mr, wire_cfg);
         [[maybe_unused]] const auto [euler_wire_initial2, shift_wire_initial2] =
             tilt_surface<decltype(wire_det_w_mat),
                          decltype(wire_det_w_mat)::masks::id::e_drift_cell>(

tests/integration_tests/io/io_json_detector_roundtrip.cpp

@@ -7,7 +7,7 @@
 
 // Project include(s)
 #include "detray/definitions/detail/algebra.hpp"
-#include "detray/detectors/create_telescope_detector.hpp"
+#include "detray/detectors/build_telescope_detector.hpp"
 #include "detray/detectors/create_toy_geometry.hpp"
 #include "detray/detectors/create_wire_chamber.hpp"
 #include "detray/io/common/geometry_reader.hpp"
@@ -151,7 +151,7 @@ GTEST_TEST(io, json_telescope_detector_reader) {
 
     // Telescope detector
     vecmem::host_memory_resource host_mr;
-    auto [tel_det, tel_names] = create_telescope_detector(host_mr, tel_cfg);
+    auto [tel_det, tel_names] = build_telescope_detector(host_mr, tel_cfg);
 
     std::map<std::string, std::string> file_names;
     file_names["geometry"] = "telescope_detector_geometry.json";

tests/tools/src/generate_telescope_detector.cpp

@@ -7,7 +7,7 @@
 
 // Project include(s)
 #include "detray/definitions/units.hpp"
-#include "detray/detectors/create_telescope_detector.hpp"
+#include "detray/detectors/build_telescope_detector.hpp"
 #include "detray/geometry/mask.hpp"
 #include "detray/geometry/shapes.hpp"
 #include "detray/io/frontend/detector_writer.hpp"
@@ -53,7 +53,7 @@ void write_telecope(const po::variables_map &vm,
 
     // Build the detector
     vecmem::host_memory_resource host_mr;
-    auto [tel_det, tel_names] = create_telescope_detector(host_mr, tel_cfg);
+    auto [tel_det, tel_names] = build_telescope_detector(host_mr, tel_cfg);
 
     // Write to file
     detray::io::write_detector(tel_det, tel_names, writer_cfg);

tests/unit_tests/cpu/CMakeLists.txt

@@ -31,6 +31,7 @@ macro( detray_add_cpu_test algebra )
       "coordinates/polar2.cpp"
       "builders/detector_builder.cpp"
       "builders/grid_builder.cpp"
+      "builders/homogeneous_volume_material_builder.cpp"
       "builders/homogeneous_material_builder.cpp"
       "builders/material_map_builder.cpp"
       "builders/volume_builder.cpp"

tests/unit_tests/cpu/builders/homogeneous_material_builder.cpp

@@ -9,7 +9,6 @@
 #include "detray/builders/homogeneous_material_builder.hpp"
 
 #include "detray/builders/cuboid_portal_generator.hpp"
-#include "detray/builders/detector_builder.hpp"
 #include "detray/builders/homogeneous_material_factory.hpp"
 #include "detray/builders/surface_factory.hpp"
 #include "detray/builders/volume_builder.hpp"