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Turn submap state into a per trajectory list. (#281) 

Related to #256.
master
Holger Rapp 2017-05-15 12:12:30 +02:00 committed by GitHub
parent fde9272533
commit c084624958
4 changed files with 164 additions and 157 deletions
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136
cartographer/mapping_2d/sparse_pose_graph.cc
View File

@ -115,15 +115,16 @@ void SparsePoseGraph::AddScan(
});
trajectory_connectivity_.Add(trajectory_id);
if (submap_indices_.count(insertion_submaps.back()) == 0) {
submap_indices_.emplace(insertion_submaps.back(),
static_cast<int>(submap_indices_.size()));
submap_states_.emplace_back();
submap_states_.back().submap = insertion_submaps.back();
submap_states_.back().id = mapping::SubmapId{
trajectory_id, num_submaps_in_trajectory_[trajectory_id]};
++num_submaps_in_trajectory_[trajectory_id];
CHECK_EQ(submap_states_.size(), submap_indices_.size());
if (submap_ids_.count(insertion_submaps.back()) == 0) {
submap_states_.resize(
std::max<size_t>(submap_states_.size(), trajectory_id + 1));
auto& trajectory_submap_states = submap_states_.at(trajectory_id);
submap_ids_.emplace(
insertion_submaps.back(),
mapping::SubmapId{trajectory_id,
static_cast<int>(trajectory_submap_states.size())});
trajectory_submap_states.emplace_back();
trajectory_submap_states.back().submap = insertion_submaps.back();
}
const mapping::Submap* const finished_submap =
insertion_submaps.front()->finished_probability_grid != nullptr
@ -138,8 +139,9 @@ void SparsePoseGraph::AddScan(
}
AddWorkItem([=]() REQUIRES(mutex_) {
ComputeConstraintsForScan(flat_scan_index, matching_submap, insertion_submaps,
finished_submap, pose, covariance);
ComputeConstraintsForScan(flat_scan_index, matching_submap,
insertion_submaps, finished_submap, pose,
covariance);
});
}
@ -164,8 +166,7 @@ void SparsePoseGraph::AddImuData(const mapping::Submaps* trajectory,
}
void SparsePoseGraph::ComputeConstraint(const int scan_index,
const int submap_index) {
const mapping::SubmapId submap_id = submap_states_[submap_index].id;
const mapping::SubmapId& submap_id) {
const transform::Rigid2d relative_pose =
optimization_problem_.submap_data()
.at(submap_id.trajectory_id)
@ -176,27 +177,31 @@ void SparsePoseGraph::ComputeConstraint(const int scan_index,
const mapping::Submaps* const scan_trajectory =
trajectory_nodes_[scan_index].constant_data->trajectory;
const int scan_trajectory_id = trajectory_ids_.at(scan_trajectory);
const int submap_trajectory_id =
submap_states_[submap_index].id.trajectory_id;
// Only globally match against submaps not in this trajectory.
if (scan_trajectory_id != submap_trajectory_id &&
if (scan_trajectory_id != submap_id.trajectory_id &&
global_localization_samplers_[scan_trajectory_id]->Pulse()) {
constraint_builder_.MaybeAddGlobalConstraint(
submap_id, submap_states_[submap_index].submap,
submap_id,
submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.submap,
scan_index_to_node_id_.at(scan_index), scan_index,
&trajectory_connectivity_,
&trajectory_nodes_[scan_index].constant_data->range_data_2d.returns);
} else {
const bool scan_and_submap_trajectories_connected =
reverse_connected_components_.count(scan_trajectory_id) > 0 &&
reverse_connected_components_.count(submap_trajectory_id) > 0 &&
reverse_connected_components_.count(submap_id.trajectory_id) > 0 &&
reverse_connected_components_.at(scan_trajectory_id) ==
reverse_connected_components_.at(submap_trajectory_id);
if (scan_trajectory_id == submap_trajectory_id ||
reverse_connected_components_.at(submap_id.trajectory_id);
if (scan_trajectory_id == submap_id.trajectory_id ||
scan_and_submap_trajectories_connected) {
constraint_builder_.MaybeAddConstraint(
submap_id, submap_states_[submap_index].submap,
submap_id,
submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.submap,
scan_index_to_node_id_.at(scan_index), scan_index,
&trajectory_nodes_[scan_index].constant_data->range_data_2d.returns,
relative_pose);
@ -206,14 +211,16 @@ void SparsePoseGraph::ComputeConstraint(const int scan_index,
void SparsePoseGraph::ComputeConstraintsForOldScans(
const mapping::Submap* submap) {
const int submap_index = GetSubmapIndex(submap);
const auto submap_id = GetSubmapId(submap);
const auto& node_data = optimization_problem_.node_data();
CHECK_GT(node_data.size(), 0);
CHECK_LT(node_data.size(), std::numeric_limits<int>::max());
const int num_nodes = node_data.size();
for (int scan_index = 0; scan_index < num_nodes; ++scan_index) {
if (submap_states_[submap_index].scan_indices.count(scan_index) == 0) {
ComputeConstraint(scan_index, submap_index);
if (submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.scan_indices.count(scan_index) == 0) {
ComputeConstraint(scan_index, submap_id);
}
}
}
@ -238,16 +245,20 @@ void SparsePoseGraph::ComputeConstraintsForScan(
trajectory_ids_.at(scan_data->trajectory), scan_data->time, pose,
optimized_pose);
for (const mapping::Submap* submap : insertion_submaps) {
const int submap_index = GetSubmapIndex(submap);
CHECK(!submap_states_[submap_index].finished);
submap_states_[submap_index].scan_indices.emplace(scan_index);
const mapping::SubmapId submap_id = GetSubmapId(submap);
CHECK(!submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.finished);
submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.scan_indices.emplace(scan_index);
// Unchanged covariance as (submap <- map) is a translation.
const transform::Rigid2d constraint_transform =
sparse_pose_graph::ComputeSubmapPose(*submap).inverse() * pose;
constexpr double kFakePositionCovariance = 1e-6;
constexpr double kFakeOrientationCovariance = 1e-6;
constraints_.push_back(Constraint{
submap_states_[submap_index].id,
submap_id,
scan_index_to_node_id_.at(scan_index),
{transform::Embed3D(constraint_transform),
common::ComputeSpdMatrixSqrtInverse(
@ -258,18 +269,28 @@ void SparsePoseGraph::ComputeConstraintsForScan(
Constraint::INTRA_SUBMAP});
}
CHECK_LT(submap_states_.size(), std::numeric_limits<int>::max());
const int num_submaps = submap_states_.size();
for (int submap_index = 0; submap_index != num_submaps; ++submap_index) {
if (submap_states_[submap_index].finished) {
CHECK_EQ(submap_states_[submap_index].scan_indices.count(scan_index), 0);
ComputeConstraint(scan_index, submap_index);
for (size_t trajectory_id = 0; trajectory_id < submap_states_.size();
++trajectory_id) {
for (size_t submap_index = 0;
submap_index < submap_states_.at(trajectory_id).size();
++submap_index) {
if (submap_states_.at(trajectory_id).at(submap_index).finished) {
CHECK_EQ(submap_states_.at(trajectory_id)
.at(submap_index)
.scan_indices.count(scan_index),
0);
ComputeConstraint(scan_index,
mapping::SubmapId{static_cast<int>(trajectory_id),
static_cast<int>(submap_index)});
}
}
}
if (finished_submap != nullptr) {
const int finished_submap_index = GetSubmapIndex(finished_submap);
SubmapState& finished_submap_state = submap_states_[finished_submap_index];
const mapping::SubmapId finished_submap_id = GetSubmapId(finished_submap);
SubmapState& finished_submap_state =
submap_states_.at(finished_submap_id.trajectory_id)
.at(finished_submap_id.submap_index);
CHECK(!finished_submap_state.finished);
// We have a new completed submap, so we look into adding constraints for
// old scans.
@ -441,44 +462,33 @@ std::vector<transform::Rigid3d> SparsePoseGraph::ExtrapolateSubmapTransforms(
if (trajectory_ids_.count(trajectory) == 0) {
return {transform::Rigid3d::Identity()};
}
const int trajectory_id = trajectory_ids_.at(trajectory);
size_t flat_index = 0;
size_t flat_index_of_result_back = -1;
const size_t trajectory_id = trajectory_ids_.at(trajectory);
if (trajectory_id >= submap_states_.size()) {
return {transform::Rigid3d::Identity()};
}
// Submaps for which we have optimized poses.
std::vector<transform::Rigid3d> result;
for (; flat_index != submap_states_.size(); ++flat_index) {
const auto& state = submap_states_[flat_index];
if (state.id.trajectory_id != trajectory_id) {
continue;
}
if (static_cast<size_t>(trajectory_id) >= submap_transforms.size() ||
result.size() >= submap_transforms.at(trajectory_id).size()) {
break;
}
result.push_back(transform::Embed3D(
submap_transforms.at(trajectory_id).at(result.size()).pose));
flat_index_of_result_back = flat_index;
}
// Extrapolate to the remaining submaps.
for (; flat_index != submap_states_.size(); ++flat_index) {
const auto& state = submap_states_[flat_index];
if (state.id.trajectory_id != trajectory_id) {
continue;
}
if (result.empty()) {
for (const auto& state : submap_states_.at(trajectory_id)) {
if (trajectory_id < submap_transforms.size() &&
result.size() < submap_transforms.at(trajectory_id).size()) {
// Submaps for which we have optimized poses.
result.push_back(
Embed3D(submap_transforms.at(trajectory_id).at(result.size()).pose));
} else if (result.empty()) {
result.push_back(transform::Rigid3d::Identity());
} else {
// Accessing local_pose() in Submaps is okay, since the member is const.
// Extrapolate to the remaining submaps. Accessing local_pose() in
// Submaps is okay, since the member is const.
result.push_back(result.back() *
submap_states_[flat_index_of_result_back]
submap_states_.at(trajectory_id)
.at(result.size() - 1)
.submap->local_pose()
.inverse() *
state.submap->local_pose());
}
flat_index_of_result_back = flat_index;
}
if (result.empty()) {
result.push_back(transform::Rigid3d::Identity());
}

24
cartographer/mapping_2d/sparse_pose_graph.h
View File

@ -108,22 +108,16 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
// against this submap. Likewise, all new scans are matched against submaps
// which are finished.
bool finished = false;
mapping::SubmapId id;
};
// Handles a new work item.
void AddWorkItem(std::function<void()> work_item) REQUIRES(mutex_);
int GetSubmapIndex(const mapping::Submap* submap) const REQUIRES(mutex_) {
const auto iterator = submap_indices_.find(submap);
CHECK(iterator != submap_indices_.end());
return iterator->second;
}
mapping::SubmapId GetSubmapId(const mapping::Submap* submap) const
REQUIRES(mutex_) {
return submap_states_.at(GetSubmapIndex(submap)).id;
const auto iterator = submap_ids_.find(submap);
CHECK(iterator != submap_ids_.end());
return iterator->second;
}
// Grows the optimization problem to have an entry for every element of
@ -140,8 +134,8 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
const kalman_filter::Pose2DCovariance& covariance) REQUIRES(mutex_);
// Computes constraints for a scan and submap pair.
void ComputeConstraint(const int scan_index, const int submap_index)
REQUIRES(mutex_);
void ComputeConstraint(const int scan_index,
const mapping::SubmapId& submap_id) REQUIRES(mutex_);
// Adds constraints for older scans whenever a new submap is finished.
void ComputeConstraintsForOldScans(const mapping::Submap* submap)
@ -191,11 +185,11 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
sparse_pose_graph::ConstraintBuilder constraint_builder_ GUARDED_BY(mutex_);
std::vector<Constraint> constraints_ GUARDED_BY(mutex_);
// Submaps get assigned an index and state as soon as they are seen, even
// Submaps get assigned an ID and state as soon as they are seen, even
// before they take part in the background computations.
std::map<const mapping::Submap*, int> submap_indices_ GUARDED_BY(mutex_);
std::vector<SubmapState> submap_states_ GUARDED_BY(mutex_);
std::map<int, int> num_submaps_in_trajectory_ GUARDED_BY(mutex_);
std::map<const mapping::Submap*, mapping::SubmapId> submap_ids_
GUARDED_BY(mutex_);
std::vector<std::vector<SubmapState>> submap_states_ GUARDED_BY(mutex_);
// Mapping to flat indices to aid the transition to per-trajectory data
// structures.

137
cartographer/mapping_3d/sparse_pose_graph.cc
View File

@ -112,15 +112,16 @@ void SparsePoseGraph::AddScan(
mapping::TrajectoryNode{&constant_node_data_.back(), optimized_pose});
trajectory_connectivity_.Add(trajectory_id);
if (submap_indices_.count(insertion_submaps.back()) == 0) {
submap_indices_.emplace(insertion_submaps.back(),
static_cast<int>(submap_indices_.size()));
submap_states_.emplace_back();
submap_states_.back().submap = insertion_submaps.back();
submap_states_.back().id = mapping::SubmapId{
trajectory_id, num_submaps_in_trajectory_[trajectory_id]};
++num_submaps_in_trajectory_[trajectory_id];
CHECK_EQ(submap_states_.size(), submap_indices_.size());
if (submap_ids_.count(insertion_submaps.back()) == 0) {
submap_states_.resize(
std::max<size_t>(submap_states_.size(), trajectory_id + 1));
auto& trajectory_submap_states = submap_states_.at(trajectory_id);
submap_ids_.emplace(
insertion_submaps.back(),
mapping::SubmapId{trajectory_id,
static_cast<int>(trajectory_submap_states.size())});
trajectory_submap_states.emplace_back();
trajectory_submap_states.back().submap = insertion_submaps.back();
}
const Submap* const finished_submap =
insertion_submaps.front()->finished ? insertion_submaps.front() : nullptr;
@ -133,8 +134,9 @@ void SparsePoseGraph::AddScan(
}
AddWorkItem([=]() REQUIRES(mutex_) {
ComputeConstraintsForScan(flat_scan_index, matching_submap, insertion_submaps,
finished_submap, pose, covariance);
ComputeConstraintsForScan(flat_scan_index, matching_submap,
insertion_submaps, finished_submap, pose,
covariance);
});
}
@ -164,8 +166,7 @@ void SparsePoseGraph::AddImuData(const mapping::Submaps* trajectory,
}
void SparsePoseGraph::ComputeConstraint(const int scan_index,
const int submap_index) {
const mapping::SubmapId submap_id = submap_states_[submap_index].id;
const mapping::SubmapId& submap_id) {
const transform::Rigid3d relative_pose =
optimization_problem_.submap_data()
.at(submap_id.trajectory_id)
@ -176,26 +177,30 @@ void SparsePoseGraph::ComputeConstraint(const int scan_index,
const mapping::Submaps* const scan_trajectory =
trajectory_nodes_[scan_index].constant_data->trajectory;
const int scan_trajectory_id = trajectory_ids_.at(scan_trajectory);
const int submap_trajectory_id =
submap_states_[submap_index].id.trajectory_id;
// Only globally match against submaps not in this trajectory.
if (scan_trajectory_id != submap_trajectory_id &&
if (scan_trajectory_id != submap_id.trajectory_id &&
global_localization_samplers_[scan_trajectory_id]->Pulse()) {
constraint_builder_.MaybeAddGlobalConstraint(
submap_id, submap_states_[submap_index].submap,
submap_id,
submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.submap,
scan_index_to_node_id_.at(scan_index), scan_index,
&trajectory_connectivity_, trajectory_nodes_);
} else {
const bool scan_and_submap_trajectories_connected =
reverse_connected_components_.count(scan_trajectory_id) > 0 &&
reverse_connected_components_.count(submap_trajectory_id) > 0 &&
reverse_connected_components_.count(submap_id.trajectory_id) > 0 &&
reverse_connected_components_.at(scan_trajectory_id) ==
reverse_connected_components_.at(submap_trajectory_id);
if (scan_trajectory_id == submap_trajectory_id ||
reverse_connected_components_.at(submap_id.trajectory_id);
if (scan_trajectory_id == submap_id.trajectory_id ||
scan_and_submap_trajectories_connected) {
constraint_builder_.MaybeAddConstraint(
submap_id, submap_states_[submap_index].submap,
submap_id,
submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.submap,
scan_index_to_node_id_.at(scan_index), scan_index, trajectory_nodes_,
relative_pose);
}
@ -203,14 +208,16 @@ void SparsePoseGraph::ComputeConstraint(const int scan_index,
}
void SparsePoseGraph::ComputeConstraintsForOldScans(const Submap* submap) {
const int submap_index = GetSubmapIndex(submap);
const auto submap_id = GetSubmapId(submap);
const auto& node_data = optimization_problem_.node_data();
CHECK_GT(node_data.size(), 0);
CHECK_LT(node_data.size(), std::numeric_limits<int>::max());
const int num_nodes = node_data.size();
for (int scan_index = 0; scan_index < num_nodes; ++scan_index) {
if (submap_states_[submap_index].scan_indices.count(scan_index) == 0) {
ComputeConstraint(scan_index, submap_index);
if (submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.scan_indices.count(scan_index) == 0) {
ComputeConstraint(scan_index, submap_id);
}
}
}
@ -235,14 +242,18 @@ void SparsePoseGraph::ComputeConstraintsForScan(
trajectory_ids_.at(scan_data->trajectory), scan_data->time,
optimized_pose);
for (const Submap* submap : insertion_submaps) {
const int submap_index = GetSubmapIndex(submap);
CHECK(!submap_states_[submap_index].finished);
submap_states_[submap_index].scan_indices.emplace(scan_index);
const mapping::SubmapId submap_id = GetSubmapId(submap);
CHECK(!submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.finished);
submap_states_.at(submap_id.trajectory_id)
.at(submap_id.submap_index)
.scan_indices.emplace(scan_index);
// Unchanged covariance as (submap <- map) is a translation.
const transform::Rigid3d constraint_transform =
submap->local_pose().inverse() * pose;
constraints_.push_back(
Constraint{submap_states_[submap_index].id,
Constraint{submap_id,
scan_index_to_node_id_.at(scan_index),
{constraint_transform,
common::ComputeSpdMatrixSqrtInverse(
@ -251,18 +262,28 @@ void SparsePoseGraph::ComputeConstraintsForScan(
Constraint::INTRA_SUBMAP});
}
CHECK_LT(submap_states_.size(), std::numeric_limits<int>::max());
const int num_submaps = submap_states_.size();
for (int submap_index = 0; submap_index != num_submaps; ++submap_index) {
if (submap_states_[submap_index].finished) {
CHECK_EQ(submap_states_[submap_index].scan_indices.count(scan_index), 0);
ComputeConstraint(scan_index, submap_index);
for (size_t trajectory_id = 0; trajectory_id < submap_states_.size();
++trajectory_id) {
for (size_t submap_index = 0;
submap_index < submap_states_.at(trajectory_id).size();
++submap_index) {
if (submap_states_.at(trajectory_id).at(submap_index).finished) {
CHECK_EQ(submap_states_.at(trajectory_id)
.at(submap_index)
.scan_indices.count(scan_index),
0);
ComputeConstraint(scan_index,
mapping::SubmapId{static_cast<int>(trajectory_id),
static_cast<int>(submap_index)});
}
}
}
if (finished_submap != nullptr) {
const int finished_submap_index = GetSubmapIndex(finished_submap);
SubmapState& finished_submap_state = submap_states_[finished_submap_index];
const mapping::SubmapId finished_submap_id = GetSubmapId(finished_submap);
SubmapState& finished_submap_state =
submap_states_.at(finished_submap_id.trajectory_id)
.at(finished_submap_id.submap_index);
CHECK(!finished_submap_state.finished);
// We have a new completed submap, so we look into adding constraints for
// old scans.
@ -433,44 +454,32 @@ std::vector<transform::Rigid3d> SparsePoseGraph::ExtrapolateSubmapTransforms(
if (trajectory_ids_.count(trajectory) == 0) {
return {transform::Rigid3d::Identity()};
}
const int trajectory_id = trajectory_ids_.at(trajectory);
size_t flat_index = 0;
size_t flat_index_of_result_back = -1;
// Submaps for which we have optimized poses.
std::vector<transform::Rigid3d> result;
for (; flat_index != submap_states_.size(); ++flat_index) {
const auto& state = submap_states_[flat_index];
if (state.id.trajectory_id != trajectory_id) {
continue;
}
if (static_cast<size_t>(trajectory_id) >= submap_transforms.size() ||
result.size() >= submap_transforms.at(trajectory_id).size()) {
break;
}
result.push_back(
submap_transforms.at(trajectory_id).at(result.size()).pose);
flat_index_of_result_back = flat_index;
const size_t trajectory_id = trajectory_ids_.at(trajectory);
if (trajectory_id >= submap_states_.size()) {
return {transform::Rigid3d::Identity()};
}
// Extrapolate to the remaining submaps.
for (; flat_index != submap_states_.size(); ++flat_index) {
const auto& state = submap_states_[flat_index];
if (state.id.trajectory_id != trajectory_id) {
continue;
}
if (result.empty()) {
std::vector<transform::Rigid3d> result;
for (const auto& state : submap_states_.at(trajectory_id)) {
if (trajectory_id < submap_transforms.size() &&
result.size() < submap_transforms.at(trajectory_id).size()) {
// Submaps for which we have optimized poses.
result.push_back(
submap_transforms.at(trajectory_id).at(result.size()).pose);
} else if (result.empty()) {
result.push_back(transform::Rigid3d::Identity());
} else {
// Accessing local_pose() in Submaps is okay, since the member is const.
// Extrapolate to the remaining submaps. Accessing local_pose() in Submaps
// is okay, since the member is const.
result.push_back(result.back() *
submap_states_[flat_index_of_result_back]
submap_states_.at(trajectory_id)
.at(result.size() - 1)
.submap->local_pose()
.inverse() *
state.submap->local_pose());
}
flat_index_of_result_back = flat_index;
}
if (result.empty()) {
result.push_back(transform::Rigid3d::Identity());
}

24
cartographer/mapping_3d/sparse_pose_graph.h
View File

@ -110,22 +110,16 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
// against this submap. Likewise, all new scans are matched against submaps
// which are finished.
bool finished = false;
mapping::SubmapId id;
};
// Handles a new work item.
void AddWorkItem(std::function<void()> work_item) REQUIRES(mutex_);
int GetSubmapIndex(const mapping::Submap* submap) const REQUIRES(mutex_) {
const auto iterator = submap_indices_.find(submap);
CHECK(iterator != submap_indices_.end());
return iterator->second;
}
mapping::SubmapId GetSubmapId(const mapping::Submap* submap) const
REQUIRES(mutex_) {
return submap_states_.at(GetSubmapIndex(submap)).id;
const auto iterator = submap_ids_.find(submap);
CHECK(iterator != submap_ids_.end());
return iterator->second;
}
// Grows the optimization problem to have an entry for every element of
@ -141,8 +135,8 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
const kalman_filter::PoseCovariance& covariance) REQUIRES(mutex_);
// Computes constraints for a scan and submap pair.
void ComputeConstraint(const int scan_index, const int submap_index)
REQUIRES(mutex_);
void ComputeConstraint(const int scan_index,
const mapping::SubmapId& submap_id) REQUIRES(mutex_);
// Adds constraints for older scans whenever a new submap is finished.
void ComputeConstraintsForOldScans(const Submap* submap) REQUIRES(mutex_);
@ -191,11 +185,11 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
sparse_pose_graph::ConstraintBuilder constraint_builder_ GUARDED_BY(mutex_);
std::vector<Constraint> constraints_ GUARDED_BY(mutex_);
// Submaps get assigned an index and state as soon as they are seen, even
// Submaps get assigned an ID and state as soon as they are seen, even
// before they take part in the background computations.
std::map<const mapping::Submap*, int> submap_indices_ GUARDED_BY(mutex_);
std::vector<SubmapState> submap_states_ GUARDED_BY(mutex_);
std::map<int, int> num_submaps_in_trajectory_ GUARDED_BY(mutex_);
std::map<const mapping::Submap*, mapping::SubmapId> submap_ids_
GUARDED_BY(mutex_);
std::vector<std::vector<SubmapState>> submap_states_ GUARDED_BY(mutex_);
// Mapping to flat indices to aid the transition to per-trajectory data
// structures.