trajectory_connectivity_state.h
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00001 /*
00002  * Copyright 2017 The Cartographer Authors
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *      http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef CARTOGRAPHER_MAPPING_INTERNAL_TRAJECTORY_CONNECTIVITY_STATE_H_
00018 #define CARTOGRAPHER_MAPPING_INTERNAL_TRAJECTORY_CONNECTIVITY_STATE_H_
00019 
00020 #include "cartographer/common/time.h"
00021 #include "cartographer/mapping/internal/connected_components.h"
00022 
00023 namespace cartographer {
00024 namespace mapping {
00025 
00026 // A class that tracks the connectivity state between trajectories. Compared to
00027 // ConnectedComponents it tracks additionally the last time that a global
00028 // constraint connected to trajectories.
00029 //
00030 // This class is thread-compatible.
00031 class TrajectoryConnectivityState {
00032  public:
00033   TrajectoryConnectivityState() {}
00034 
00035   TrajectoryConnectivityState(const TrajectoryConnectivityState&) = delete;
00036   TrajectoryConnectivityState& operator=(const TrajectoryConnectivityState&) =
00037       delete;
00038 
00039   // Add a trajectory which is initially connected to only itself.
00040   void Add(int trajectory_id);
00041 
00042   // Connect two trajectories. If either trajectory is untracked, it will be
00043   // tracked. This function is invariant to the order of its arguments. Repeated
00044   // calls to Connect increment the connectivity count and update the last
00045   // connected time.
00046   void Connect(int trajectory_id_a, int trajectory_id_b, common::Time time);
00047 
00048   // Determines if two trajectories have been (transitively) connected. If
00049   // either trajectory is not being tracked, returns false, except when it is
00050   // the same trajectory, where it returns true. This function is invariant to
00051   // the order of its arguments.
00052   bool TransitivelyConnected(int trajectory_id_a, int trajectory_id_b) const;
00053 
00054   // The trajectory IDs, grouped by connectivity.
00055   std::vector<std::vector<int>> Components() const;
00056 
00057   // Return the last connection count between the two trajectories. If either of
00058   // the trajectories is untracked or they have never been connected returns the
00059   // beginning of time.
00060   common::Time LastConnectionTime(int trajectory_id_a, int trajectory_id_b);
00061 
00062  private:
00063   // ConnectedComponents are thread safe.
00064   mutable ConnectedComponents connected_components_;
00065 
00066   // Tracks the last time a direct connection between two trajectories has
00067   // been added. The exception is when a connection between two trajectories
00068   // connects two formerly unconnected connected components. In this case all
00069   // bipartite trajectories entries for these components are updated with the
00070   // new connection time.
00071   std::map<std::pair<int, int>, common::Time> last_connection_time_map_;
00072 };
00073 
00074 }  // namespace mapping
00075 }  // namespace cartographer
00076 
00077 #endif  // CARTOGRAPHER_MAPPING_INTERNAL_TRAJECTORY_CONNECTIVITY_STATE_H_


cartographer
Author(s): The Cartographer Authors
autogenerated on Thu May 9 2019 02:27:36