bool isEndOfRoad(const ConnectedRoad &,
const ConnectedRoad &possible_right_turn,
const ConnectedRoad &possible_left_turn)
{
return angularDeviation(possible_right_turn.turn.angle, 90) < NARROW_TURN_ANGLE &&
angularDeviation(possible_left_turn.turn.angle, 270) < NARROW_TURN_ANGLE &&
angularDeviation(possible_right_turn.turn.angle, possible_left_turn.turn.angle) >
2 * NARROW_TURN_ANGLE;
}
std::size_t BearingClass::findMatchingBearing(const double bearing) const
{
BOOST_ASSERT(!available_bearings.empty());
// the small size of the intersections allows a linear compare
auto discrete_bearing = static_cast<DiscreteBearing>(bearing);
auto max_element =
std::max_element(available_bearings.begin(),
available_bearings.end(),
[&](const DiscreteBearing first, const DiscreteBearing second) {
return angularDeviation(first, discrete_bearing) >
angularDeviation(second, discrete_bearing);
});
return std::distance(available_bearings.begin(), max_element);
}
void IntersectionHandler::assignFork(const EdgeID via_edge,
ConnectedRoad &left,
ConnectedRoad ¢er,
ConnectedRoad &right) const
{
// TODO handle low priority road classes in a reasonable way
if (left.entry_allowed && center.entry_allowed && right.entry_allowed)
{
left.turn.instruction = {TurnType::Fork, DirectionModifier::SlightLeft};
if (angularDeviation(center.turn.angle, 180) < MAXIMAL_ALLOWED_NO_TURN_DEVIATION)
{
const auto &in_data = node_based_graph.GetEdgeData(via_edge);
const auto &out_data = node_based_graph.GetEdgeData(center.turn.eid);
if (detail::requiresAnnouncement(in_data, out_data))
{
center.turn.instruction = {TurnType::Fork, DirectionModifier::Straight};
}
else
{
center.turn.instruction = {TurnType::Suppressed, DirectionModifier::Straight};
}
}
else
{
center.turn.instruction = {TurnType::Fork, DirectionModifier::Straight};
}
right.turn.instruction = {TurnType::Fork, DirectionModifier::SlightRight};
}
else if (left.entry_allowed)
{
if (right.entry_allowed)
assignFork(via_edge, left, right);
else if (center.entry_allowed)
assignFork(via_edge, left, center);
else
left.turn.instruction = {findBasicTurnType(via_edge, left),
getTurnDirection(left.turn.angle)};
}
else if (right.entry_allowed)
{
if (center.entry_allowed)
assignFork(via_edge, center, right);
else
right.turn.instruction = {findBasicTurnType(via_edge, right),
getTurnDirection(right.turn.angle)};
}
else
{
if (center.entry_allowed)
center.turn.instruction = {findBasicTurnType(via_edge, center),
getTurnDirection(center.turn.angle)};
}
}
bool IntersectionHandler::isThroughStreet(const std::size_t index,
const Intersection &intersection) const
{
if (node_based_graph.GetEdgeData(intersection[index].turn.eid).name_id == EMPTY_NAMEID)
return false;
for (const auto &road : intersection)
{
// a through street cannot start at our own position
if (road.turn.angle < std::numeric_limits<double>::epsilon())
continue;
if (angularDeviation(road.turn.angle, intersection[index].turn.angle) >
(STRAIGHT_ANGLE - NARROW_TURN_ANGLE) &&
node_based_graph.GetEdgeData(road.turn.eid).name_id ==
node_based_graph.GetEdgeData(intersection[index].turn.eid).name_id)
return true;
}
return false;
}
void ConnectedRoad::mirror()
{
const constexpr DirectionModifier::Enum mirrored_modifiers[] = {DirectionModifier::UTurn,
DirectionModifier::SharpLeft,
DirectionModifier::Left,
DirectionModifier::SlightLeft,
DirectionModifier::Straight,
DirectionModifier::SlightRight,
DirectionModifier::Right,
DirectionModifier::SharpRight};
static_assert(sizeof(mirrored_modifiers) / sizeof(DirectionModifier::Enum) ==
DirectionModifier::MaxDirectionModifier,
"The list of mirrored modifiers needs to match the available modifiers in size.");
if (angularDeviation(angle, 0) > std::numeric_limits<double>::epsilon())
{
angle = 360 - angle;
instruction.direction_modifier = mirrored_modifiers[instruction.direction_modifier];
}
}
inline bool isThroughStreet(const std::size_t index,
const IntersectionType &intersection,
const util::NodeBasedDynamicGraph &node_based_graph,
const EdgeBasedNodeDataContainer &node_data_container,
const util::NameTable &name_table,
const SuffixTable &street_name_suffix_table)
{
const auto &data_at_index = node_data_container.GetAnnotation(
node_based_graph.GetEdgeData(intersection[index].eid).annotation_data);
if (data_at_index.name_id == EMPTY_NAMEID)
return false;
// a through street cannot start at our own position -> index 1
for (std::size_t road_index = 1; road_index < intersection.size(); ++road_index)
{
if (road_index == index)
continue;
const auto &road = intersection[road_index];
const auto &road_data = node_data_container.GetAnnotation(
node_based_graph.GetEdgeData(road.eid).annotation_data);
// roads have a near straight angle (180 degree)
const bool is_nearly_straight = angularDeviation(road.angle, intersection[index].angle) >
(STRAIGHT_ANGLE - FUZZY_ANGLE_DIFFERENCE);
const bool have_same_name = HaveIdenticalNames(
data_at_index.name_id, road_data.name_id, name_table, street_name_suffix_table);
const bool have_same_category =
node_based_graph.GetEdgeData(intersection[index].eid).flags.road_classification ==
node_based_graph.GetEdgeData(road.eid).flags.road_classification;
if (is_nearly_straight && have_same_name && have_same_category)
return true;
}
return false;
}
boost::optional<EdgeID> SelectRoadByNameOnlyChoiceAndStraightness::
operator()(const NodeID /*nid*/,
const EdgeID /*via_edge_id*/,
const IntersectionView &intersection,
const util::NodeBasedDynamicGraph &node_based_graph,
const EdgeBasedNodeDataContainer &node_data_container) const
{
BOOST_ASSERT(!intersection.empty());
const auto comparator = [&](const IntersectionViewData &lhs, const IntersectionViewData &rhs) {
// the score of an elemnt results in an ranking preferring valid entries, if required over
// invalid requested name_ids over non-requested narrow deviations over non-narrow
const auto score = [&](const IntersectionViewData &road) {
double result_score = 0;
// since angular deviation is limited by 0-180, we add 360 for invalid
if (requires_entry && !road.entry_allowed)
result_score += 360.;
// 180 for undesired name-ids
if (desired_name_id !=
node_data_container
.GetAnnotation(node_based_graph.GetEdgeData(road.eid).annotation_data)
.name_id)
result_score += 180;
return result_score + angularDeviation(road.angle, STRAIGHT_ANGLE);
};
return score(lhs) < score(rhs);
};
const auto min_element =
std::min_element(std::next(std::begin(intersection)), std::end(intersection), comparator);
if (min_element == intersection.end() || (requires_entry && !min_element->entry_allowed))
return {};
else
return (*min_element).eid;
}
// "Sliproads" occur when we've got a link between two roads (MOTORWAY_LINK, etc), but
// the two roads are *also* directly connected shortly afterwards.
// In these cases, we tag the turn-type as "sliproad", and then in post-processing
// we emit a "turn", instead of "take the ramp"+"merge"
Intersection TurnAnalysis::handleSliproads(const EdgeID source_edge_id,
Intersection intersection) const
{
auto intersection_node_id = node_based_graph.GetTarget(source_edge_id);
const auto linkTest = [this](const ConnectedRoad &road) {
return // isLinkClass(
// node_based_graph.GetEdgeData(road.turn.eid).road_classification.road_class) &&
!node_based_graph.GetEdgeData(road.turn.eid).roundabout && road.entry_allowed &&
angularDeviation(road.turn.angle, STRAIGHT_ANGLE) <= 2 * NARROW_TURN_ANGLE;
};
bool hasNarrow =
std::find_if(intersection.begin(), intersection.end(), linkTest) != intersection.end();
if (!hasNarrow)
return intersection;
const auto source_edge_data = node_based_graph.GetEdgeData(source_edge_id);
// Find the continuation of the intersection we're on
auto next_road = std::find_if(
intersection.begin(),
intersection.end(),
[this, source_edge_data](const ConnectedRoad &road) {
const auto road_edge_data = node_based_graph.GetEdgeData(road.turn.eid);
// Test to see if the source edge and the one we're looking at are the same road
return road_edge_data.road_classification.road_class ==
source_edge_data.road_classification.road_class &&
road_edge_data.name_id != EMPTY_NAMEID &&
road_edge_data.name_id == source_edge_data.name_id && road.entry_allowed &&
angularDeviation(road.turn.angle, STRAIGHT_ANGLE) < FUZZY_ANGLE_DIFFERENCE;
});
const bool hasNext = next_road != intersection.end();
if (!hasNext)
{
return intersection;
}
// Threshold check, if the intersection is too far away, don't bother continuing
const auto &next_road_data = node_based_graph.GetEdgeData(next_road->turn.eid);
if (next_road_data.distance > MAX_SLIPROAD_THRESHOLD)
{
return intersection;
}
const auto next_road_next_intersection =
intersection_generator(intersection_node_id, next_road->turn.eid);
const auto next_intersection_node = node_based_graph.GetTarget(next_road->turn.eid);
std::unordered_set<NameID> target_road_names;
for (const auto &road : next_road_next_intersection)
{
const auto &target_data = node_based_graph.GetEdgeData(road.turn.eid);
target_road_names.insert(target_data.name_id);
}
for (auto &road : intersection)
{
if (linkTest(road))
{
auto target_intersection = intersection_generator(intersection_node_id, road.turn.eid);
for (const auto &candidate_road : target_intersection)
{
const auto &candidate_data = node_based_graph.GetEdgeData(candidate_road.turn.eid);
if (target_road_names.count(candidate_data.name_id) > 0 &&
node_based_graph.GetTarget(candidate_road.turn.eid) == next_intersection_node)
{
road.turn.instruction.type = TurnType::Sliproad;
break;
}
}
}
}
if (next_road->turn.instruction.type == TurnType::Fork)
{
const auto &next_data = node_based_graph.GetEdgeData(next_road->turn.eid);
if (next_data.name_id == source_edge_data.name_id)
{
if (angularDeviation(next_road->turn.angle, STRAIGHT_ANGLE) < 5)
next_road->turn.instruction.type = TurnType::Suppressed;
else
next_road->turn.instruction.type = TurnType::Continue;
next_road->turn.instruction.direction_modifier =
getTurnDirection(next_road->turn.angle);
}
else if (next_data.name_id != EMPTY_NAMEID)
{
next_road->turn.instruction.type = TurnType::NewName;
next_road->turn.instruction.direction_modifier =
getTurnDirection(next_road->turn.angle);
}
else
{
next_road->turn.instruction.type = TurnType::Suppressed;
}
}
return intersection;
}
/*
* Segregated Roads often merge onto a single intersection.
* While technically representing different roads, they are
* often looked at as a single road.
* Due to the merging, turn Angles seem off, wenn we compute them from the
* initial positions.
*
* b<b<b<b(1)<b<b<b
* aaaaa-b
* b>b>b>b(2)>b>b>b
*
* Would be seen as a slight turn going fro a to (2). A Sharp turn going from
* (1) to (2).
*
* In cases like these, we megre this segregated roads into a single road to
* end up with a case like:
*
* aaaaa-bbbbbb
*
* for the turn representation.
* Anything containing the first u-turn in a merge affects all other angles
* and is handled separately from all others.
*/
Intersection IntersectionGenerator::mergeSegregatedRoads(Intersection intersection) const
{
const auto getRight = [&](std::size_t index) {
return (index + intersection.size() - 1) % intersection.size();
};
const auto mergable = [&](std::size_t first, std::size_t second) -> bool {
const auto &first_data = node_based_graph.GetEdgeData(intersection[first].turn.eid);
const auto &second_data = node_based_graph.GetEdgeData(intersection[second].turn.eid);
return first_data.name_id != INVALID_NAME_ID && first_data.name_id == second_data.name_id &&
!first_data.roundabout && !second_data.roundabout &&
first_data.travel_mode == second_data.travel_mode &&
first_data.road_classification == second_data.road_classification &&
// compatible threshold
angularDeviation(intersection[first].turn.angle, intersection[second].turn.angle) <
60 &&
first_data.reversed != second_data.reversed;
};
const auto merge = [](const ConnectedRoad &first,
const ConnectedRoad &second) -> ConnectedRoad {
if (!first.entry_allowed)
{
ConnectedRoad result = second;
result.turn.angle = (first.turn.angle + second.turn.angle) / 2;
if (first.turn.angle - second.turn.angle > 180)
result.turn.angle += 180;
if (result.turn.angle > 360)
result.turn.angle -= 360;
return result;
}
else
{
BOOST_ASSERT(!second.entry_allowed);
ConnectedRoad result = first;
result.turn.angle = (first.turn.angle + second.turn.angle) / 2;
if (first.turn.angle - second.turn.angle > 180)
result.turn.angle += 180;
if (result.turn.angle > 360)
result.turn.angle -= 360;
return result;
}
};
if (intersection.size() <= 1)
return intersection;
const bool is_connected_to_roundabout = [this, &intersection]() {
for (const auto &road : intersection)
{
if (node_based_graph.GetEdgeData(road.turn.eid).roundabout)
return true;
}
return false;
}();
// check for merges including the basic u-turn
// these result in an adjustment of all other angles
if (mergable(0, intersection.size() - 1))
{
const double correction_factor =
(360 - intersection[intersection.size() - 1].turn.angle) / 2;
for (std::size_t i = 1; i + 1 < intersection.size(); ++i)
intersection[i].turn.angle += correction_factor;
// FIXME if we have a left-sided country, we need to switch this off and enable it below
intersection[0] = merge(intersection.front(), intersection.back());
intersection[0].turn.angle = 0;
if (is_connected_to_roundabout)
{
// We are merging a u-turn against the direction of a roundabout
//
// -----------> roundabout
// / \
// out in
//
// These cases have to be disabled, even if they are not forbidden specifically by a
// relation
intersection[0].entry_allowed = false;
}
intersection.pop_back();
}
else if (mergable(0, 1))
{
const double correction_factor = (intersection[1].turn.angle) / 2;
for (std::size_t i = 2; i < intersection.size(); ++i)
intersection[i].turn.angle += correction_factor;
intersection[0] = merge(intersection[0], intersection[1]);
intersection[0].turn.angle = 0;
intersection.erase(intersection.begin() + 1);
}
// a merge including the first u-turn requres an adjustment of the turn angles
// therefore these are handled prior to this step
for (std::size_t index = 2; index < intersection.size(); ++index)
{
if (mergable(index, getRight(index)))
{
intersection[getRight(index)] =
merge(intersection[getRight(index)], intersection[index]);
intersection.erase(intersection.begin() + index);
--index;
}
}
const auto ByAngle = [](const ConnectedRoad &first, const ConnectedRoad second) {
return first.turn.angle < second.turn.angle;
};
std::sort(std::begin(intersection), std::end(intersection), ByAngle);
return intersection;
}
TurnInstruction IntersectionHandler::getInstructionForObvious(const std::size_t num_roads,
const EdgeID via_edge,
const bool through_street,
const ConnectedRoad &road) const
{
const auto type = findBasicTurnType(via_edge, road);
// handle travel modes:
const auto in_mode = node_based_graph.GetEdgeData(via_edge).travel_mode;
const auto out_mode = node_based_graph.GetEdgeData(road.turn.eid).travel_mode;
if (type == TurnType::OnRamp)
{
return {TurnType::OnRamp, getTurnDirection(road.turn.angle)};
}
if (angularDeviation(road.turn.angle, 0) < 0.01)
{
return {TurnType::Turn, DirectionModifier::UTurn};
}
if (type == TurnType::Turn)
{
const auto &in_data = node_based_graph.GetEdgeData(via_edge);
const auto &out_data = node_based_graph.GetEdgeData(road.turn.eid);
if (in_data.name_id != out_data.name_id &&
requiresNameAnnounced(name_table.GetNameForID(in_data.name_id),
name_table.GetNameForID(out_data.name_id),
street_name_suffix_table))
{
// obvious turn onto a through street is a merge
if (through_street)
{
return {TurnType::Merge,
road.turn.angle > STRAIGHT_ANGLE ? DirectionModifier::SlightRight
: DirectionModifier::SlightLeft};
}
else
{
return {TurnType::NewName, getTurnDirection(road.turn.angle)};
}
}
else
{
if (in_mode == out_mode)
return {TurnType::Suppressed, getTurnDirection(road.turn.angle)};
else
return {TurnType::Notification, getTurnDirection(road.turn.angle)};
}
}
BOOST_ASSERT(type == TurnType::Continue);
if (in_mode != out_mode)
{
return {TurnType::Notification, getTurnDirection(road.turn.angle)};
}
if (num_roads > 2)
{
return {TurnType::Suppressed, getTurnDirection(road.turn.angle)};
}
else
{
return {TurnType::NoTurn, getTurnDirection(road.turn.angle)};
}
}
void IntersectionHandler::assignFork(const EdgeID via_edge,
ConnectedRoad &left,
ConnectedRoad &right) const
{
const auto &in_data = node_based_graph.GetEdgeData(via_edge);
const bool low_priority_left = isLowPriorityRoadClass(
node_based_graph.GetEdgeData(left.turn.eid).road_classification.road_class);
const bool low_priority_right = isLowPriorityRoadClass(
node_based_graph.GetEdgeData(right.turn.eid).road_classification.road_class);
if ((angularDeviation(left.turn.angle, STRAIGHT_ANGLE) < MAXIMAL_ALLOWED_NO_TURN_DEVIATION &&
angularDeviation(right.turn.angle, STRAIGHT_ANGLE) > FUZZY_ANGLE_DIFFERENCE))
{
// left side is actually straight
const auto &out_data = node_based_graph.GetEdgeData(left.turn.eid);
if (detail::requiresAnnouncement(in_data, out_data))
{
if (low_priority_right && !low_priority_left)
{
left.turn.instruction = getInstructionForObvious(3, via_edge, false, left);
right.turn.instruction = {findBasicTurnType(via_edge, right),
DirectionModifier::SlightRight};
}
else
{
if (low_priority_left && !low_priority_right)
{
left.turn.instruction = {findBasicTurnType(via_edge, left),
DirectionModifier::SlightLeft};
right.turn.instruction = {findBasicTurnType(via_edge, right),
DirectionModifier::SlightRight};
}
else
{
left.turn.instruction = {TurnType::Fork, DirectionModifier::SlightLeft};
right.turn.instruction = {TurnType::Fork, DirectionModifier::SlightRight};
}
}
}
else
{
left.turn.instruction = {TurnType::Suppressed, DirectionModifier::Straight};
right.turn.instruction = {findBasicTurnType(via_edge, right),
DirectionModifier::SlightRight};
}
}
else if (angularDeviation(right.turn.angle, STRAIGHT_ANGLE) <
MAXIMAL_ALLOWED_NO_TURN_DEVIATION &&
angularDeviation(left.turn.angle, STRAIGHT_ANGLE) > FUZZY_ANGLE_DIFFERENCE)
{
// right side is actually straight
const auto &out_data = node_based_graph.GetEdgeData(right.turn.eid);
if (angularDeviation(right.turn.angle, STRAIGHT_ANGLE) <
MAXIMAL_ALLOWED_NO_TURN_DEVIATION &&
angularDeviation(left.turn.angle, STRAIGHT_ANGLE) > FUZZY_ANGLE_DIFFERENCE)
{
if (detail::requiresAnnouncement(in_data, out_data))
{
if (low_priority_left && !low_priority_right)
{
left.turn.instruction = {findBasicTurnType(via_edge, left),
DirectionModifier::SlightLeft};
right.turn.instruction = getInstructionForObvious(3, via_edge, false, right);
}
else
{
if (low_priority_right && !low_priority_left)
{
left.turn.instruction = {findBasicTurnType(via_edge, left),
DirectionModifier::SlightLeft};
right.turn.instruction = {findBasicTurnType(via_edge, right),
DirectionModifier::SlightRight};
}
else
{
right.turn.instruction = {TurnType::Fork, DirectionModifier::SlightRight};
left.turn.instruction = {TurnType::Fork, DirectionModifier::SlightLeft};
}
}
}
else
{
right.turn.instruction = {TurnType::Suppressed, DirectionModifier::Straight};
left.turn.instruction = {findBasicTurnType(via_edge, left),
DirectionModifier::SlightLeft};
}
}
}
// left side of fork
if (low_priority_right && !low_priority_left)
left.turn.instruction = {TurnType::Suppressed, DirectionModifier::SlightLeft};
else
{
if (low_priority_left && !low_priority_right)
left.turn.instruction = {TurnType::Turn, DirectionModifier::SlightLeft};
else
left.turn.instruction = {TurnType::Fork, DirectionModifier::SlightLeft};
}
// right side of fork
if (low_priority_left && !low_priority_right)
right.turn.instruction = {TurnType::Suppressed, DirectionModifier::SlightLeft};
else
{
if (low_priority_right && !low_priority_left)
right.turn.instruction = {TurnType::Turn, DirectionModifier::SlightRight};
else
right.turn.instruction = {TurnType::Fork, DirectionModifier::SlightRight};
}
}
bool findPreviousIntersection(const NodeID node_v,
const EdgeID via_edge,
const Intersection intersection,
const TurnAnalysis &turn_analysis,
const util::NodeBasedDynamicGraph &node_based_graph,
// output parameters
NodeID &result_node,
EdgeID &result_via_edge,
Intersection &result_intersection)
{
/* We need to find the intersection that is located prior to via_edge.
*
* NODE_U -> PREVIOUS_ID -> NODE_V -> VIA_EDGE -> NODE_W:INTERSECTION
* NODE_U? <- STRAIGHTMOST <- NODE_V <- UTURN
* NODE_U? -> UTURN == PREVIOUSE_ID? -> NODE_V -> VIA_EDGE
*
* To do so, we first get the intersection atNODE and find the straightmost turn from that
* node. This will result in NODE_X. The uturn in the intersection at NODE_X should be
* PREVIOUS_ID. To verify that find, we check the intersection using our PREVIOUS_ID candidate
* to check the intersection at NODE for via_edge
*/
const constexpr double COMBINE_DISTANCE_CUTOFF = 30;
// we check if via-edge is too short. In this case the previous turn cannot influence the turn
// at via_edge and the intersection at NODE_W
if (node_based_graph.GetEdgeData(via_edge).distance > COMBINE_DISTANCE_CUTOFF)
return false;
// Node -> Via_Edge -> Intersection[0 == UTURN] -> reverse_of(via_edge) -> Intersection at node
// (looking at the reverse direction).
const auto node_w = node_based_graph.GetTarget(via_edge);
const auto u_turn_at_node_w = intersection[0].turn.eid;
const auto node_v_reverse_intersection =
turn_analysis.getIntersection(node_w, u_turn_at_node_w);
// Continue along the straightmost turn. If there is no straight turn, we cannot find a valid
// previous intersection.
const auto straightmost_at_v_in_reverse =
findClosestTurn(node_v_reverse_intersection, STRAIGHT_ANGLE);
if (angularDeviation(straightmost_at_v_in_reverse->turn.angle, STRAIGHT_ANGLE) >
FUZZY_ANGLE_DIFFERENCE)
return false;
const auto node_u = node_based_graph.GetTarget(straightmost_at_v_in_reverse->turn.eid);
const auto node_u_reverse_intersection =
turn_analysis.getIntersection(node_v, straightmost_at_v_in_reverse->turn.eid);
// now check that the u-turn at the given intersection connects to via-edge
// The u-turn at the now found intersection should, hopefully, represent the previous edge.
result_node = node_u;
result_via_edge = node_u_reverse_intersection[0].turn.eid;
// if the edge is not traversable, we obviously don't have a previous intersection or couldn't
// find it.
if (node_based_graph.GetEdgeData(result_via_edge).reversed)
return false;
result_intersection = turn_analysis.getIntersection(node_u, result_via_edge);
const auto check_via_edge = findClosestTurn(result_intersection, STRAIGHT_ANGLE)->turn.eid;
if (check_via_edge != via_edge)
return false;
result_intersection =
turn_analysis.assignTurnTypes(node_u, result_via_edge, std::move(result_intersection));
return true;
}
boost::optional<EdgeID> SelectStraightmostRoadByNameAndOnlyChoice::
operator()(const NodeID /*nid*/,
const EdgeID /*via_edge_id*/,
const IntersectionView &intersection,
const util::NodeBasedDynamicGraph &node_based_graph,
const EdgeBasedNodeDataContainer &node_data_container) const
{
BOOST_ASSERT(!intersection.empty());
if (intersection.size() == 1)
return {};
const auto comparator = [&](const IntersectionViewData &lhs, const IntersectionViewData &rhs) {
// the score of an elemnt results in an ranking preferring valid entries, if required over
// invalid requested name_ids over non-requested narrow deviations over non-narrow
const auto score = [&](const IntersectionViewData &road) {
double result_score = 0;
// since angular deviation is limited by 0-180, we add 360 for invalid
if (requires_entry && !road.entry_allowed)
result_score += 360.;
// 180 for undesired name-ids
if (desired_name_id !=
node_data_container
.GetAnnotation(node_based_graph.GetEdgeData(road.eid).annotation_data)
.name_id)
result_score += 180;
return result_score + angularDeviation(road.angle, STRAIGHT_ANGLE);
};
return score(lhs) < score(rhs);
};
const auto count_desired_name =
std::count_if(std::begin(intersection), std::end(intersection), [&](const auto &road) {
return node_data_container
.GetAnnotation(node_based_graph.GetEdgeData(road.eid).annotation_data)
.name_id == desired_name_id;
});
if (count_desired_name > 2)
return {};
const auto min_element =
std::min_element(std::next(std::begin(intersection)), std::end(intersection), comparator);
const auto is_valid_choice = !requires_entry || min_element->entry_allowed;
if (!is_valid_choice)
return {};
// only road exiting or continuing in the same general direction
const auto has_valid_angle =
((intersection.size() == 2 ||
intersection.findClosestTurn(STRAIGHT_ANGLE) == min_element) &&
angularDeviation(min_element->angle, STRAIGHT_ANGLE) < NARROW_TURN_ANGLE) &&
angularDeviation(initial_bearing, min_element->perceived_bearing) < NARROW_TURN_ANGLE;
if (has_valid_angle)
return (*min_element).eid;
// in some cases, stronger turns are appropriate. We allow turns of just a bit over 90 degrees,
// if it's not a end of road situation. These angles come into play where roads split into dual
// carriage-ways.
//
// e - - f
// a - - - - b
// c - - d
// |
// g
//
// is technically
//
//
// a - - - - b (ce) - - (fg)
// |
// g
const auto is_only_choice_with_same_name =
count_desired_name <= 2 && // <= in case we come from a bridge, otherwise we have a u-turn
// and the outgoing edge
node_data_container
.GetAnnotation(node_based_graph.GetEdgeData(min_element->eid).annotation_data)
.name_id == desired_name_id &&
angularDeviation(min_element->angle, STRAIGHT_ANGLE) < 100; // don't do crazy turns
// do not allow major turns in the road, if other similar turns are present
// e.g.a turn at the end of the road:
//
// a - - a - - a - b - b
// |
// a - - a
// |
// c
//
// Such a turn can never be part of a merge
// We check if there is a similar turn to the other side. If such a turn exists, we consider the
// continuation of the road not possible
if (stop_on_ambiguous_turns &&
util::angularDeviation(STRAIGHT_ANGLE, min_element->angle) > GROUP_ANGLE)
{
auto opposite = intersection.findClosestTurn(util::bearing::reverse(min_element->angle));
auto opposite_deviation = util::angularDeviation(min_element->angle, opposite->angle);
// d - - - - c - - - -e
// |
// |
// a - - - - b
// from b-c onto min_element d with opposite side e
if (opposite_deviation > (180 - FUZZY_ANGLE_DIFFERENCE))
return {};
// e
// |
// a - - - - b - - - - -d
// doing a left turn while straight is a choice
auto const best = intersection.findClosestTurn(STRAIGHT_ANGLE);
if (util::angularDeviation(best->angle, STRAIGHT_ANGLE) < FUZZY_ANGLE_DIFFERENCE)
return {};
}
return is_only_choice_with_same_name ? boost::optional<EdgeID>(min_element->eid) : boost::none;
}