osrm-backend/src/extractor/guidance/turn_lane_matcher.cpp

290 lines
12 KiB
C++

#include "extractor/guidance/toolkit.hpp"
#include "extractor/guidance/turn_lane_matcher.hpp"
#include "util/guidance/toolkit.hpp"
#include <boost/assert.hpp>
#include <boost/numeric/conversion/cast.hpp>
#include <functional>
namespace osrm
{
namespace extractor
{
namespace guidance
{
namespace lanes
{
// Translate Turn Tags into a Matching Direction Modifier
DirectionModifier::Enum getMatchingModifier(const TurnLaneType::Mask &tag)
{
const constexpr TurnLaneType::Mask tag_by_modifier[] = {TurnLaneType::uturn,
TurnLaneType::sharp_right,
TurnLaneType::right,
TurnLaneType::slight_right,
TurnLaneType::straight,
TurnLaneType::slight_left,
TurnLaneType::left,
TurnLaneType::sharp_left,
TurnLaneType::merge_to_left,
TurnLaneType::merge_to_right};
const auto index =
std::distance(tag_by_modifier, std::find(tag_by_modifier, tag_by_modifier + 10, tag));
BOOST_ASSERT(index <= 10);
const constexpr DirectionModifier::Enum modifiers[11] = {
DirectionModifier::UTurn,
DirectionModifier::SharpRight,
DirectionModifier::Right,
DirectionModifier::SlightRight,
DirectionModifier::Straight,
DirectionModifier::SlightLeft,
DirectionModifier::Left,
DirectionModifier::SharpLeft,
DirectionModifier::Straight,
DirectionModifier::Straight,
DirectionModifier::UTurn}; // fallback for invalid tags
return modifiers[index];
}
// check whether a match of a given tag and a turn instruction can be seen as valid
bool isValidMatch(const TurnLaneType::Mask &tag, const TurnInstruction instruction)
{
using util::guidance::hasLeftModifier;
using util::guidance::hasRightModifier;
const auto isMirroredModifier = [](const TurnInstruction instruction) {
return instruction.type == TurnType::Merge;
};
if (tag == TurnLaneType::uturn)
{
return hasLeftModifier(instruction) ||
instruction.direction_modifier == DirectionModifier::UTurn;
}
else if (tag == TurnLaneType::sharp_right || tag == TurnLaneType::right ||
tag == TurnLaneType::slight_right)
{
if (isMirroredModifier(instruction))
return hasLeftModifier(instruction);
else
// needs to be adjusted for left side driving
return leavesRoundabout(instruction) || hasRightModifier(instruction);
}
else if (tag == TurnLaneType::straight)
{
return instruction.direction_modifier == DirectionModifier::Straight ||
instruction.type == TurnType::Suppressed || instruction.type == TurnType::NewName ||
instruction.type == TurnType::StayOnRoundabout || entersRoundabout(instruction) ||
(instruction.type ==
TurnType::Fork && // Forks can be experienced, even for straight segments
(instruction.direction_modifier == DirectionModifier::SlightLeft ||
instruction.direction_modifier == DirectionModifier::SlightRight)) ||
(instruction.type ==
TurnType::Continue && // Forks can be experienced, even for straight segments
(instruction.direction_modifier == DirectionModifier::SlightLeft ||
instruction.direction_modifier == DirectionModifier::SlightRight)) ||
instruction.type == TurnType::UseLane;
}
else if (tag == TurnLaneType::slight_left || tag == TurnLaneType::left ||
tag == TurnLaneType::sharp_left)
{
if (isMirroredModifier(instruction))
return hasRightModifier(instruction);
else
{
// Needs to be fixed for left side driving
return (instruction.type == TurnType::StayOnRoundabout) || hasLeftModifier(instruction);
}
}
return false;
}
// Every tag is somewhat idealized in form of the expected angle. A through lane should go straight
// (or follow a 180 degree turn angle between in/out segments.) The following function tries to find
// the best possible match for every tag in a given intersection, considering a few corner cases
// introduced to OSRM handling u-turns
typename Intersection::const_iterator findBestMatch(const TurnLaneType::Mask &tag,
const Intersection &intersection)
{
const constexpr double idealized_turn_angles[] = {0, 35, 90, 135, 180, 225, 270, 315};
const auto idealized_angle = idealized_turn_angles[getMatchingModifier(tag)];
return std::min_element(
intersection.begin(),
intersection.end(),
[idealized_angle, &tag](const ConnectedRoad &lhs, const ConnectedRoad &rhs) {
// prefer valid matches
if (isValidMatch(tag, lhs.turn.instruction) != isValidMatch(tag, rhs.turn.instruction))
return isValidMatch(tag, lhs.turn.instruction);
// if the entry allowed flags don't match, we select the one with
// entry allowed set to true
if (lhs.entry_allowed != rhs.entry_allowed)
return lhs.entry_allowed;
return angularDeviation(idealized_angle, lhs.turn.angle) <
angularDeviation(idealized_angle, rhs.turn.angle);
});
}
// Reverse is a special case, because it requires access to the leftmost tag. It has its own
// matching function as a result of that. The leftmost tag is required, since u-turns are disabled
// by default in OSRM. Therefor we cannot check whether a turn is allowed, since it could be
// possible that it is forbidden. In addition, the best u-turn angle does not necessarily represent
// the u-turn, since it could be a sharp-left turn instead on a road with a middle island.
typename Intersection::const_iterator
findBestMatchForReverse(const TurnLaneType::Mask &neighbor_tag, const Intersection &intersection)
{
const auto neighbor_itr = findBestMatch(neighbor_tag, intersection);
if ((neighbor_itr + 1 == intersection.cend()) || (neighbor_itr == intersection.cbegin() + 1))
return intersection.begin();
const constexpr double idealized_turn_angles[] = {0, 35, 90, 135, 180, 225, 270, 315};
const TurnLaneType::Mask tag = TurnLaneType::uturn;
const auto idealized_angle = idealized_turn_angles[getMatchingModifier(tag)];
return std::min_element(
intersection.begin() + std::distance(intersection.begin(), neighbor_itr),
intersection.end(),
[idealized_angle, &tag](const ConnectedRoad &lhs, const ConnectedRoad &rhs) {
// prefer valid matches
if (isValidMatch(tag, lhs.turn.instruction) != isValidMatch(tag, rhs.turn.instruction))
return isValidMatch(tag, lhs.turn.instruction);
// if the entry allowed flags don't match, we select the one with
// entry allowed set to true
if (lhs.entry_allowed != rhs.entry_allowed)
return lhs.entry_allowed;
return angularDeviation(idealized_angle, lhs.turn.angle) <
angularDeviation(idealized_angle, rhs.turn.angle);
});
}
// a match is trivial if all turns can be associated with their best match in a valid way and the
// matches occur in order
bool canMatchTrivially(const Intersection &intersection, const LaneDataVector &lane_data)
{
std::size_t road_index = 1, lane = 0;
if (!lane_data.empty() && lane_data.front().tag == TurnLaneType::uturn)
{
// the very first is a u-turn to the right
if (intersection[0].entry_allowed)
lane = 1;
}
for (; road_index < intersection.size() && lane < lane_data.size(); ++road_index)
{
if (intersection[road_index].entry_allowed)
{
BOOST_ASSERT(lane_data[lane].from != INVALID_LANEID);
if (!isValidMatch(lane_data[lane].tag, intersection[road_index].turn.instruction))
return false;
if (findBestMatch(lane_data[lane].tag, intersection) !=
intersection.begin() + road_index)
return false;
++lane;
}
}
return lane == lane_data.size() ||
(lane + 1 == lane_data.size() && lane_data.back().tag == TurnLaneType::uturn);
}
Intersection triviallyMatchLanesToTurns(Intersection intersection,
const LaneDataVector &lane_data,
const util::NodeBasedDynamicGraph &node_based_graph,
const LaneDescriptionID lane_string_id,
LaneDataIdMap &lane_data_to_id)
{
std::size_t road_index = 1, lane = 0;
const auto matchRoad = [&](ConnectedRoad &road, const TurnLaneData &data) {
LaneTupelIdPair key{{LaneID(data.to - data.from + 1), data.from}, lane_string_id};
auto lane_data_id = boost::numeric_cast<LaneDataID>(lane_data_to_id.size());
const auto it = lane_data_to_id.find(key);
if (it == lane_data_to_id.end())
lane_data_to_id.insert({key, lane_data_id});
else
lane_data_id = it->second;
// set lane id instead after the switch:
road.turn.lane_data_id = lane_data_id;
};
if (!lane_data.empty() && lane_data.front().tag == TurnLaneType::uturn)
{
// the very first is a u-turn to the right
if (intersection[0].entry_allowed)
{
std::size_t u_turn = 0;
if (node_based_graph.GetEdgeData(intersection[0].turn.eid).reversed)
{
if (intersection.size() <= 1 || !intersection[1].entry_allowed ||
intersection[1].turn.instruction.direction_modifier !=
DirectionModifier::SharpRight)
{
// cannot match u-turn in a valid way
return intersection;
}
u_turn = 1;
road_index = 2;
}
intersection[u_turn].entry_allowed = true;
intersection[u_turn].turn.instruction.type = TurnType::Turn;
intersection[u_turn].turn.instruction.direction_modifier = DirectionModifier::UTurn;
matchRoad(intersection[u_turn], lane_data.back());
// continue with the first lane
lane = 1;
}
}
for (; road_index < intersection.size() && lane < lane_data.size(); ++road_index)
{
if (intersection[road_index].entry_allowed)
{
BOOST_ASSERT(lane_data[lane].from != INVALID_LANEID);
BOOST_ASSERT(
isValidMatch(lane_data[lane].tag, intersection[road_index].turn.instruction));
BOOST_ASSERT(findBestMatch(lane_data[lane].tag, intersection) ==
intersection.begin() + road_index);
if (TurnType::Suppressed == intersection[road_index].turn.instruction.type)
intersection[road_index].turn.instruction.type = TurnType::UseLane;
matchRoad(intersection[road_index], lane_data[lane]);
++lane;
}
}
// handle reverse tag, if present
if (lane + 1 == lane_data.size() && lane_data.back().tag == TurnLaneType::uturn)
{
std::size_t u_turn = 0;
if (node_based_graph.GetEdgeData(intersection[0].turn.eid).reversed)
{
if (!intersection.back().entry_allowed ||
intersection.back().turn.instruction.direction_modifier !=
DirectionModifier::SharpLeft)
{
// cannot match u-turn in a valid way
return intersection;
}
u_turn = intersection.size() - 1;
}
intersection[u_turn].entry_allowed = true;
intersection[u_turn].turn.instruction.type = TurnType::Turn;
intersection[u_turn].turn.instruction.direction_modifier = DirectionModifier::UTurn;
matchRoad(intersection[u_turn], lane_data.back());
}
return intersection;
}
} // namespace lane_matching
} // namespace guidance
} // namespace extractor
} // namespace osrm