Acts/Utilities/Ray.hpp

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 #pragma once
0010
0011 #include "Acts/Visualization/IVisualization3D.hpp"
0012
0013 #include <Eigen/Dense>
0014
0015 namespace Acts {
0016
0017 /// Class which models a ray. It is defined by a starting point and a
0018 /// direction.
0019 /// @tparam value_t The floating point type to use
0020 /// @tparam DIM The number of dimensions in which this ray is defined (2 or 3)
0021 template <typename value_t, std::size_t DIM>
0022 class Ray {
0023  public:
0024   /// Re expose the value type
0025   using value_type = value_t;
0026   /// Vertex type based on the value type and dimension
0027   using VertexType = Eigen::Matrix<value_t, DIM, 1>;
0028   /// Vertex array type corresponding to the vertex type
0029   using vertex_array_type = Eigen::Array<value_t, DIM, 1>;
0030   /// Associated transform type
0031   using transform_type = Eigen::Transform<value_t, DIM, Eigen::Affine>;
0032
0033   /// Constructor from an origin point and a direction
0034   /// @param origin The origin of the ray
0035   /// @param dir The direction of the ray
0036   Ray(const VertexType& origin, const VertexType& dir);
0037
0038   /// Getter for the origin
0039   /// @return The origin
0040   const VertexType& origin() const { return m_origin; }
0041
0042   /// Getter for the direction
0043   /// @return The direction
0044   const VertexType& dir() const { return m_dir; }
0045
0046   /// Getter for the element wise inverse of the direction.
0047   /// @return The element wise inverse.
0048   const vertex_array_type& idir() const { return m_idir; }
0049
0050   /// Transforms this ray using a given transform and returns a new instance
0051   /// @param trf The transform to apply
0052   /// @return Copy of this ray with the transform applied
0053   Ray<value_t, DIM> transformed(const transform_type& trf) const;
0054
0055   /// Write information on this instance to an outstream.
0056   /// @param os The out stream
0057   /// @return The out stream given as an argument
0058   std::ostream& toStream(std::ostream& os) const;
0059
0060   /// Helper to draw this ray using a given visualization helper.
0061   /// @param helper The visualization helper
0062   /// @param far_distance The "length" of the drawn line representing the ray
0063   void draw(IVisualization3D& helper, value_type far_distance = 10) const
0064     requires(DIM == 3);
0065
0066  private:
0067   VertexType m_origin;
0068   VertexType m_dir;
0069   vertex_array_type m_idir;
0070 };
0071
0072 /// Overload of the outstream operator
0073 /// @param os The out stream
0074 /// @param ray The ray to write to @p os
0075 /// @return The outstream given in @p os
0076 template <typename T, std::size_t D>
0077 std::ostream& operator<<(std::ostream& os, const Ray<T, D>& ray) {
0078   ray.dump(os);
0079   return os;
0080 }
0081
0082 using Ray3D = Ray<double, 3>;
0083
0084 }  // namespace Acts
0085
0086 #include "Acts/Utilities/Ray.ipp"