data_generator.hpp

// This file is part of the ACTS project.
//
// Copyright (C) 2016 CERN for the benefit of the ACTS project
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
#pragma once
 
// Project include(s)
#include "algebra/vc_aos.hpp"
#include "detray/algebra/concepts.hpp"
 
// System include(s)
#include <algorithm>
#include <vector>
 
namespace detray::algebra {

template <detray::concepts::vector vector_aos_t>
inline void fill_random_vec(std::vector<vector_aos_t> &collection) {
  // Generate a vector of the right type with random values
  auto rand_obj = [&]() {
    return vector_aos_t{vector_aos_t::array_type::Random()};
  };
 
  collection.resize(collection.capacity());
  std::ranges::generate(collection, rand_obj);
}

template <detray::concepts::transform3D transform3_t>
inline void fill_random_trf(std::vector<transform3_t> &collection) {
  // Generate a random, but valid affine transformation
  auto rand_obj = []() {
    using vector_t = typename transform3_t::vector3;
    vector_t x_axis;
    vector_t z_axis;
    vector_t t;
 
    x_axis = vector_t{vector_t::array_type::Random()};
    x_axis = detray::vector::normalize(x_axis);
 
    z_axis = vector_t{vector_t::array_type::Random()};
    z_axis = detray::vector::normalize(z_axis);
 
    t = vector_t{vector_t::array_type::Random()};
    t = detray::vector::normalize(t);
 
    // Gram-Schmidt projection
    typename transform3_t::scalar_type coeff =
        detray::vector::dot(x_axis, z_axis) / detray::vector::norm(x_axis);
    z_axis = x_axis - coeff * z_axis;
 
    return transform3_t{t, x_axis, detray::vector::normalize(z_axis)};
  };
 
  collection.resize(collection.capacity());
  std::ranges::generate(collection, rand_obj);
}

template <detray::concepts::matrix matrix_t>
inline void fill_random_matrix(std::vector<matrix_t> &collection) {
  // Generate a random, but valid affine transformation
  auto rand_obj = []() {
    using vector_t = typename matrix_t::vector_type;
    vector_t x_axis;
    vector_t z_axis;
    vector_t t;
 
    matrix_t m;
    for (std::size_t j = 0u; j < matrix_t::columns(); ++j) {
      m[j] = vector_t::array_type::Random();
    }
 
    return m;
  };
 
  collection.resize(collection.capacity());
  std::ranges::generate(collection, rand_obj);
}
 
}  // namespace detray::algebra