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 #pragma once
0010
0011 #include "Acts/Surfaces/ConvexPolygonBounds.hpp"
0012
0013 #include "Acts/Surfaces/detail/BoundaryCheckHelper.hpp"
0014 #include "Acts/Utilities/ThrowAssert.hpp"
0015
0016 template <typename coll_t>
0017   requires std::same_as<typename coll_t::value_type, Acts::Vector2>
0018 void Acts::ConvexPolygonBoundsBase::convex_impl(
0019     const coll_t& vertices) noexcept(false) {
0020   const std::size_t N = vertices.size();
0021   for (std::size_t i = 0; i < N; i++) {
0022     std::size_t j = (i + 1) % N;
0023     const Vector2& a = vertices[i];
0024     const Vector2& b = vertices[j];
0025
0026     const Vector2 ab = b - a;
0027     const Vector2 normal = Vector2(ab.y(), -ab.x()).normalized();
0028
0029     bool first = true;
0030     bool ref = false;
0031     // loop over all other vertices
0032     for (std::size_t k = 0; k < N; k++) {
0033       if (k == i || k == j) {
0034         continue;
0035       }
0036
0037       const Vector2& c = vertices[k];
0038       double dot = normal.dot(c - a);
0039
0040       if (first) {
0041         ref = std::signbit(dot);
0042         first = false;
0043         continue;
0044       }
0045
0046       if (std::signbit(dot) != ref) {
0047         throw std::logic_error(
0048             "ConvexPolygon: Given vertices do not form convex hull");
0049       }
0050     }
0051   }
0052 }
0053
0054 template <typename coll_t>
0055 Acts::RectangleBounds Acts::ConvexPolygonBoundsBase::makeBoundingBox(
0056     const coll_t& vertices) {
0057   Vector2 vmax, vmin;
0058   vmax = vertices[0];
0059   vmin = vertices[0];
0060
0061   for (std::size_t i = 1; i < vertices.size(); i++) {
0062     vmax = vmax.cwiseMax(vertices[i]);
0063     vmin = vmin.cwiseMin(vertices[i]);
0064   }
0065
0066   return {vmin, vmax};
0067 }
0068
0069 template <int N>
0070 Acts::ConvexPolygonBounds<N>::ConvexPolygonBounds(
0071     const std::vector<Acts::Vector2>& vertices) noexcept(false)
0072     : m_vertices(), m_boundingBox(makeBoundingBox(vertices)) {
0073   throw_assert(vertices.size() == N,
0074                "Size and number of given vertices do not match.");
0075   for (std::size_t i = 0; i < N; i++) {
0076     m_vertices[i] = vertices[i];
0077   }
0078   checkConsistency();
0079 }
0080
0081 template <int N>
0082 Acts::ConvexPolygonBounds<N>::ConvexPolygonBounds(
0083     const vertex_array& vertices) noexcept(false)
0084     : m_vertices(vertices), m_boundingBox(makeBoundingBox(vertices)) {
0085   checkConsistency();
0086 }
0087
0088 template <int N>
0089 Acts::ConvexPolygonBounds<N>::ConvexPolygonBounds(
0090     const value_array& values) noexcept(false)
0091     : m_vertices(), m_boundingBox(0., 0.) {
0092   for (std::size_t i = 0; i < N; i++) {
0093     m_vertices[i] = Vector2(values[2 * i], values[2 * i + 1]);
0094   }
0095   makeBoundingBox(m_vertices);
0096   checkConsistency();
0097 }
0098
0099 template <int N>
0100 bool Acts::ConvexPolygonBounds<N>::inside(
0101     const Acts::Vector2& lposition,
0102     const Acts::BoundaryTolerance& boundaryTolerance) const {
0103   return detail::insidePolygon(m_vertices, boundaryTolerance, lposition,
0104                                std::nullopt);
0105 }
0106
0107 template <int N>
0108 std::vector<Acts::Vector2> Acts::ConvexPolygonBounds<N>::vertices(
0109     unsigned int /*ignoredSegments*/) const {
0110   return {m_vertices.begin(), m_vertices.end()};
0111 }
0112
0113 template <int N>
0114 const Acts::RectangleBounds& Acts::ConvexPolygonBounds<N>::boundingBox() const {
0115   return m_boundingBox;
0116 }
0117
0118 template <int N>
0119 void Acts::ConvexPolygonBounds<N>::checkConsistency() const noexcept(false) {
0120   convex_impl(m_vertices);
0121 }