std::vector<TurnData>
getTileTurns(const datafacade::ContiguousInternalMemoryDataFacade<algorithm::CH> &facade,
const std::vector<RTreeLeaf> &edges,
const std::vector<std::size_t> &sorted_edge_indexes)
{
std::vector<TurnData> all_turn_data;
// Struct to hold info on all the EdgeBasedNodes that are visible in our tile
// When we create these, we insure that (source, target) and packed_geometry_id
// are all pointed in the same direction.
struct EdgeBasedNodeInfo
{
bool is_geometry_forward; // Is the geometry forward or reverse?
unsigned packed_geometry_id;
};
// Lookup table for edge-based-nodes
std::unordered_map<NodeID, EdgeBasedNodeInfo> edge_based_node_info;
struct SegmentData
{
NodeID target_node;
EdgeID edge_based_node_id;
};
std::unordered_map<NodeID, std::vector<SegmentData>> directed_graph;
// Reserve enough space for unique edge-based-nodes on every edge.
// Only a tile with all unique edges will use this much, but
// it saves us a bunch of re-allocations during iteration.
directed_graph.reserve(edges.size() * 2);
// Build an adjacency list for all the road segments visible in
// the tile
for (const auto &edge_index : sorted_edge_indexes)
{
const auto &edge = edges[edge_index];
if (edge.forward_segment_id.enabled)
{
// operator[] will construct an empty vector at [edge.u] if there is no value.
directed_graph[edge.u].push_back({edge.v, edge.forward_segment_id.id});
if (edge_based_node_info.count(edge.forward_segment_id.id) == 0)
{
edge_based_node_info[edge.forward_segment_id.id] = {true, edge.packed_geometry_id};
}
else
{
BOOST_ASSERT(edge_based_node_info[edge.forward_segment_id.id].is_geometry_forward ==
true);
BOOST_ASSERT(edge_based_node_info[edge.forward_segment_id.id].packed_geometry_id ==
edge.packed_geometry_id);
}
}
if (edge.reverse_segment_id.enabled)
{
directed_graph[edge.v].push_back({edge.u, edge.reverse_segment_id.id});
if (edge_based_node_info.count(edge.reverse_segment_id.id) == 0)
{
edge_based_node_info[edge.reverse_segment_id.id] = {false, edge.packed_geometry_id};
}
else
{
BOOST_ASSERT(edge_based_node_info[edge.reverse_segment_id.id].is_geometry_forward ==
false);
BOOST_ASSERT(edge_based_node_info[edge.reverse_segment_id.id].packed_geometry_id ==
edge.packed_geometry_id);
}
}
}
// Given a turn:
// u---v
// |
// w
// uv is the "approach"
// vw is the "exit"
std::vector<contractor::QueryEdge::EdgeData> unpacked_shortcut;
std::vector<EdgeWeight> approach_weight_vector;
std::vector<EdgeWeight> approach_duration_vector;
// Make sure we traverse the startnodes in a consistent order
// to ensure identical PBF encoding on all platforms.
std::vector<NodeID> sorted_startnodes;
sorted_startnodes.reserve(directed_graph.size());
for (const auto &startnode : directed_graph)
sorted_startnodes.push_back(startnode.first);
std::sort(sorted_startnodes.begin(), sorted_startnodes.end());
// Look at every node in the directed graph we created
for (const auto &startnode : sorted_startnodes)
{
const auto &nodedata = directed_graph[startnode];
// For all the outgoing edges from the node
for (const auto &approachedge : nodedata)
{
// If the target of this edge doesn't exist in our directed
// graph, it's probably outside the tile, so we can skip it
if (directed_graph.count(approachedge.target_node) == 0)
continue;
// For each of the outgoing edges from our target coordinate
for (const auto &exit_edge : directed_graph[approachedge.target_node])
{
// If the next edge has the same edge_based_node_id, then it's
// not a turn, so skip it
if (approachedge.edge_based_node_id == exit_edge.edge_based_node_id)
continue;
// Skip u-turns
if (startnode == exit_edge.target_node)
continue;
// Find the connection between our source road and the target node
// Since we only want to find direct edges, we cannot check shortcut edges here.
// Otherwise we might find a forward edge even though a shorter backward edge
// exists (due to oneways).
//
// a > - > - > - b
// | |
// |------ c ----|
//
// would offer a backward edge at `b` to `a` (due to the oneway from a to b)
// but could also offer a shortcut (b-c-a) from `b` to `a` which is longer.
EdgeID smaller_edge_id =
facade.FindSmallestEdge(approachedge.edge_based_node_id,
exit_edge.edge_based_node_id,
[](const contractor::QueryEdge::EdgeData &data) {
return data.forward && !data.shortcut;
});
// Depending on how the graph is constructed, we might have to look for
// a backwards edge instead. They're equivalent, just one is available for
// a forward routing search, and one is used for the backwards dijkstra
// steps. Their weight should be the same, we can use either one.
// If we didn't find a forward edge, try for a backward one
if (SPECIAL_EDGEID == smaller_edge_id)
{
smaller_edge_id =
facade.FindSmallestEdge(exit_edge.edge_based_node_id,
approachedge.edge_based_node_id,
[](const contractor::QueryEdge::EdgeData &data) {
return data.backward && !data.shortcut;
});
}
// If no edge was found, it means that there's no connection between these
// nodes, due to oneways or turn restrictions. Given the edge-based-nodes
// that we're examining here, we *should* only find directly-connected
// edges, not shortcuts
if (smaller_edge_id != SPECIAL_EDGEID)
{
const auto &data = facade.GetEdgeData(smaller_edge_id);
BOOST_ASSERT_MSG(!data.shortcut, "Connecting edge must not be a shortcut");
// Now, calculate the sum of the weight of all the segments.
if (edge_based_node_info[approachedge.edge_based_node_id].is_geometry_forward)
{
approach_weight_vector = facade.GetUncompressedForwardWeights(
edge_based_node_info[approachedge.edge_based_node_id]
.packed_geometry_id);
approach_duration_vector = facade.GetUncompressedForwardDurations(
edge_based_node_info[approachedge.edge_based_node_id]
.packed_geometry_id);
}
else
{
approach_weight_vector = facade.GetUncompressedReverseWeights(
edge_based_node_info[approachedge.edge_based_node_id]
.packed_geometry_id);
approach_duration_vector = facade.GetUncompressedReverseDurations(
edge_based_node_info[approachedge.edge_based_node_id]
.packed_geometry_id);
}
const auto sum_node_weight = std::accumulate(approach_weight_vector.begin(),
approach_weight_vector.end(),
EdgeWeight{0});
const auto sum_node_duration = std::accumulate(approach_duration_vector.begin(),
approach_duration_vector.end(),
EdgeWeight{0});
// The edge.weight is the whole edge weight, which includes the turn
// cost.
// The turn cost is the edge.weight minus the sum of the individual road
// segment weights. This might not be 100% accurate, because some
// intersections include stop signs, traffic signals and other
// penalties, but at this stage, we can't divide those out, so we just
// treat the whole lot as the "turn cost" that we'll stick on the map.
const auto turn_weight = data.weight - sum_node_weight;
const auto turn_duration = data.duration - sum_node_duration;
// Find the three nodes that make up the turn movement)
const auto node_from = startnode;
const auto node_via = approachedge.target_node;
const auto node_to = exit_edge.target_node;
const auto coord_from = facade.GetCoordinateOfNode(node_from);
const auto coord_via = facade.GetCoordinateOfNode(node_via);
const auto coord_to = facade.GetCoordinateOfNode(node_to);
// Calculate the bearing that we approach the intersection at
const auto angle_in = static_cast<int>(
util::coordinate_calculation::bearing(coord_from, coord_via));
const auto exit_bearing = static_cast<int>(
util::coordinate_calculation::bearing(coord_via, coord_to));
// Figure out the angle of the turn
auto turn_angle = exit_bearing - angle_in;
while (turn_angle > 180)
{
turn_angle -= 360;
}
while (turn_angle < -180)
{
turn_angle += 360;
}
// Save everything we need to later add all the points to the tile.
// We need the coordinate of the intersection, the angle in, the turn
// angle and the turn cost.
all_turn_data.push_back(
TurnData{coord_via, angle_in, turn_angle, turn_weight, turn_duration});
}
}
}
}
return all_turn_data;
}
