Acts/Surfaces/ConvexPolygonBounds.ipp

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 #include "Acts/Surfaces/detail/BoundaryCheckHelper.hpp"
0010 #include "Acts/Utilities/ThrowAssert.hpp"
0011
0012 template <typename coll_t>
0013   requires std::same_as<typename coll_t::value_type, Acts::Vector2>
0014 void Acts::ConvexPolygonBoundsBase::convex_impl(
0015     const coll_t& vertices) noexcept(false) {
0016   const std::size_t N = vertices.size();
0017   for (std::size_t i = 0; i < N; i++) {
0018     std::size_t j = (i + 1) % N;
0019     const Vector2& a = vertices[i];
0020     const Vector2& b = vertices[j];
0021
0022     const Vector2 ab = b - a;
0023     const Vector2 normal = Vector2(ab.y(), -ab.x()).normalized();
0024
0025     bool first = true;
0026     bool ref = false;
0027     // loop over all other vertices
0028     for (std::size_t k = 0; k < N; k++) {
0029       if (k == i || k == j) {
0030         continue;
0031       }
0032
0033       const Vector2& c = vertices[k];
0034       double dot = normal.dot(c - a);
0035
0036       if (first) {
0037         ref = std::signbit(dot);
0038         first = false;
0039         continue;
0040       }
0041
0042       if (std::signbit(dot) != ref) {
0043         throw std::logic_error(
0044             "ConvexPolygon: Given vertices do not form convex hull");
0045       }
0046     }
0047   }
0048 }
0049
0050 template <typename coll_t>
0051 Acts::RectangleBounds Acts::ConvexPolygonBoundsBase::makeBoundingBox(
0052     const coll_t& vertices) {
0053   Vector2 vmax, vmin;
0054   vmax = vertices[0];
0055   vmin = vertices[0];
0056
0057   for (std::size_t i = 1; i < vertices.size(); i++) {
0058     vmax = vmax.cwiseMax(vertices[i]);
0059     vmin = vmin.cwiseMin(vertices[i]);
0060   }
0061
0062   return {vmin, vmax};
0063 }
0064
0065 template <int N>
0066 Acts::ConvexPolygonBounds<N>::ConvexPolygonBounds(
0067     const std::vector<Acts::Vector2>& vertices) noexcept(false)
0068     : m_vertices(), m_boundingBox(makeBoundingBox(vertices)) {
0069   throw_assert(vertices.size() == N,
0070                "Size and number of given vertices do not match.");
0071   for (std::size_t i = 0; i < N; i++) {
0072     m_vertices[i] = vertices[i];
0073   }
0074   checkConsistency();
0075 }
0076
0077 template <int N>
0078 Acts::ConvexPolygonBounds<N>::ConvexPolygonBounds(
0079     const vertex_array& vertices) noexcept(false)
0080     : m_vertices(vertices), m_boundingBox(makeBoundingBox(vertices)) {
0081   checkConsistency();
0082 }
0083
0084 template <int N>
0085 Acts::ConvexPolygonBounds<N>::ConvexPolygonBounds(
0086     const value_array& values) noexcept(false)
0087     : m_vertices(), m_boundingBox(0., 0.) {
0088   for (std::size_t i = 0; i < N; i++) {
0089     m_vertices[i] = Vector2(values[2 * i], values[2 * i + 1]);
0090   }
0091   makeBoundingBox(m_vertices);
0092   checkConsistency();
0093 }
0094
0095 template <int N>
0096 bool Acts::ConvexPolygonBounds<N>::inside(
0097     const Acts::Vector2& lposition,
0098     const Acts::BoundaryTolerance& boundaryTolerance) const {
0099   return detail::insidePolygon(m_vertices, boundaryTolerance, lposition,
0100                                std::nullopt);
0101 }
0102
0103 template <int N>
0104 std::vector<Acts::Vector2> Acts::ConvexPolygonBounds<N>::vertices(
0105     unsigned int /*ignoredSegments*/) const {
0106   return {m_vertices.begin(), m_vertices.end()};
0107 }
0108
0109 template <int N>
0110 const Acts::RectangleBounds& Acts::ConvexPolygonBounds<N>::boundingBox() const {
0111   return m_boundingBox;
0112 }
0113
0114 template <int N>
0115 void Acts::ConvexPolygonBounds<N>::checkConsistency() const noexcept(false) {
0116   convex_impl(m_vertices);
0117 }