Acts/Navigation/MultiNavigationPolicy.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/Navigation/INavigationPolicy.hpp"
0012 #include "Acts/Utilities/Zip.hpp"
0013
0014 namespace Acts {
0015
0016 /// Combined navigation policy that calls all contained other navigation
0017 /// policies. This class manages multiple navigation policies and executes
0018 /// them sequentially to populate the navigation stream with candidates.
0019 class MultiNavigationPolicy final : public INavigationPolicy {
0020  public:
0021   /// Constructor from multiple unique_ptr policies
0022   /// @tparam Policies The types of the navigation policies
0023   /// @param policies Unique pointers to navigation policies
0024   template <typename... Policies>
0025   explicit MultiNavigationPolicy(std::unique_ptr<Policies>... policies)
0026       : MultiNavigationPolicy{[](auto... args) {
0027           std::vector<std::unique_ptr<INavigationPolicy>> policyPtrs;
0028
0029           if constexpr (sizeof...(args) > 0) {
0030             auto fill = [&policyPtrs](auto& policy) {
0031               policyPtrs.push_back(std::move(policy));
0032             };
0033
0034             (fill(args), ...);
0035           }
0036
0037           return policyPtrs;
0038         }(std::move(policies)...)} {}
0039
0040   /// Constructor from a vector of navigation policies
0041   /// @param policies Vector of unique pointers to navigation policies
0042   explicit MultiNavigationPolicy(
0043       std::vector<std::unique_ptr<INavigationPolicy>>&& policies);
0044
0045   /// Connect this policy to a navigation delegate
0046   /// @param delegate The navigation delegate to connect to
0047   void connect(NavigationDelegate& delegate) const override;
0048
0049   /// Access the contained navigation policies
0050   /// @return Span of const unique pointers to the navigation policies
0051   std::span<const std::unique_ptr<INavigationPolicy>> policies() const;
0052
0053   /// Visit this policy first, and then all child policies one by one.
0054   /// @param visitor The function to call for each policy
0055   void visit(const std::function<void(const INavigationPolicy&)>& visitor)
0056       const override;
0057
0058   /// Marker state for MultiNavigationPolicy.
0059   ///
0060   /// Carries no data: the child policy states live contiguously on the manager
0061   /// stack directly below this one and are addressed by count (which always
0062   /// equals the number of contained policies). This marker is pushed instead of
0063   /// the default @c EmptyState only when at least one child has a real state, so
0064   /// that the navigator knows isValid() must be consulted for this volume.
0065   struct State {};
0066
0067   /// Check if all child policies are in a valid state
0068   /// @param gctx The geometry context
0069   /// @param args The navigation arguments
0070   /// @param state The navigation policy state to check
0071   /// @param logger Logger for debug output
0072   /// @return True if all child policy states are valid, false otherwise
0073   bool isValid(const GeometryContext& gctx, const NavigationArguments& args,
0074                NavigationPolicyState& state,
0075                const Logger& logger) const override;
0076
0077   /// Create and initialize states for this policy and all child policies
0078   /// @param gctx The geometry context
0079   /// @param args The navigation arguments
0080   /// @param stateManager The state manager to push the new states onto
0081   /// @param logger Logger for debug output
0082   void createState(const GeometryContext& gctx, const NavigationArguments& args,
0083                    NavigationPolicyStateManager& stateManager,
0084                    const Logger& logger) const override;
0085
0086   /// Remove the states for this policy and all child policies from the state
0087   /// manager
0088   /// @param stateManager The state manager to pop the states from
0089   /// @param logger Logger for debug output
0090   void popState(NavigationPolicyStateManager& stateManager,
0091                 const Logger& logger) const override;
0092
0093  private:
0094   /// Initialize navigation candidates by calling all contained policies
0095   /// @param gctx The geometry context
0096   /// @param args The navigation arguments
0097   /// @param state The navigation policy state
0098   /// @param stream The navigation stream to populate
0099   /// @param logger Logger for debug output
0100   void initializeCandidates(const GeometryContext& gctx,
0101                             const NavigationArguments& args,
0102                             NavigationPolicyState& state,
0103                             AppendOnlyNavigationStream& stream,
0104                             const Logger& logger) const;
0105
0106   /// Vector of unique pointers to the contained navigation policies
0107   std::vector<std::unique_ptr<INavigationPolicy>> m_policyPtrs;
0108
0109   /// Vector of navigation delegates, one for each policy
0110   std::vector<NavigationDelegate> m_delegates;
0111 };
0112 }  // namespace Acts