osrm-backend/src/engine/guidance/post_processing.cpp
2016-07-21 17:42:10 +02:00

1210 lines
56 KiB
C++

#include "extractor/guidance/turn_instruction.hpp"
#include "engine/guidance/post_processing.hpp"
#include "engine/guidance/assemble_steps.hpp"
#include "engine/guidance/lane_processing.hpp"
#include "engine/guidance/toolkit.hpp"
#include "util/guidance/toolkit.hpp"
#include "util/guidance/turn_lanes.hpp"
#include <boost/assert.hpp>
#include <boost/numeric/conversion/cast.hpp>
#include <boost/range/algorithm_ext/erase.hpp>
#include <algorithm>
#include <cmath>
#include <cstddef>
#include <iostream>
#include <limits>
#include <utility>
using TurnInstruction = osrm::extractor::guidance::TurnInstruction;
namespace TurnType = osrm::extractor::guidance::TurnType;
namespace DirectionModifier = osrm::extractor::guidance::DirectionModifier;
using osrm::util::guidance::angularDeviation;
using osrm::util::guidance::getTurnDirection;
namespace osrm
{
namespace engine
{
namespace guidance
{
namespace
{
const constexpr std::size_t MIN_END_OF_ROAD_INTERSECTIONS = std::size_t{2};
const constexpr double MAX_COLLAPSE_DISTANCE = 30;
inline bool choiceless(const RouteStep &step, const RouteStep &previous)
{
// if the next turn is choiceless, we consider longer turn roads collapsable than usually
// accepted. We might need to improve this to find out whether we merge onto a through-street.
BOOST_ASSERT(!step.intersections.empty());
const auto is_without_choice = previous.distance < 4 * MAX_COLLAPSE_DISTANCE &&
1 >= std::count(step.intersections.front().entry.begin(),
step.intersections.front().entry.end(),
true);
return is_without_choice;
}
// List of types that can be collapsed, if all other restrictions pass
bool isCollapsableInstruction(const TurnInstruction instruction)
{
return instruction.type == TurnType::NewName ||
(instruction.type == TurnType::Suppressed &&
instruction.direction_modifier == DirectionModifier::Straight) ||
(instruction.type == TurnType::Turn &&
instruction.direction_modifier == DirectionModifier::Straight) ||
(instruction.type == TurnType::Continue &&
instruction.direction_modifier == DirectionModifier::Straight) ||
(instruction.type == TurnType::Merge);
}
// A check whether two instructions can be treated as one. This is only the case for very short
// maneuvers that can, in some form, be seen as one. The additional in_step is to find out about
// a possible u-turn.
bool collapsable(const RouteStep &step)
{
return step.distance < MAX_COLLAPSE_DISTANCE &&
(step.maneuver.instruction.type == TurnType::UseLane ||
isCollapsableInstruction(step.maneuver.instruction));
}
bool compatible(const RouteStep &lhs, const RouteStep &rhs) { return lhs.mode == rhs.mode; }
double nameSegmentLength(std::size_t at, const std::vector<RouteStep> &steps)
{
double result = steps[at].distance;
while (at + 1 < steps.size() && steps[at + 1].name_id == steps[at].name_id)
{
++at;
result += steps[at].distance;
}
return result;
}
// invalidate a step and set its content to nothing
void invalidateStep(RouteStep &step) { step = getInvalidRouteStep(); }
// Compute the angle between two bearings on a normal turn circle
//
// Bearings Angles
//
// 0 180
// 315 45 225 135
//
// 270 x 90 270 x 90
//
// 225 135 315 45
// 180 0
//
// A turn from north to north-east offerst bearing 0 and 45 has to be translated
// into a turn of 135 degrees. The same holdes for 90 - 135 (east to south
// east).
// For north, the transformation works by angle = 540 (360 + 180) - exit_bearing
// % 360;
// All other cases are handled by first rotating both bearings to an
// entry_bearing of 0.
double turn_angle(const double entry_bearing, const double exit_bearing)
{
const double offset = 360 - entry_bearing;
const double rotated_exit = [](double bearing, const double offset) {
bearing += offset;
return bearing > 360 ? bearing - 360 : bearing;
}(exit_bearing, offset);
const auto angle = 540 - rotated_exit;
return angle > 360 ? angle - 360 : angle;
}
RouteStep forwardInto(RouteStep destination, const RouteStep &source)
{
// Merge a turn into a silent turn
// Overwrites turn instruction and increases exit NR
destination.duration += source.duration;
destination.distance += source.distance;
destination.maneuver.exit = source.maneuver.exit;
if (destination.geometry_begin < source.geometry_begin)
{
destination.intersections.insert(destination.intersections.end(),
source.intersections.begin(),
source.intersections.end());
}
else
{
destination.intersections.insert(destination.intersections.begin(),
source.intersections.begin(),
source.intersections.end());
}
destination.geometry_begin = std::min(destination.geometry_begin, source.geometry_begin);
destination.geometry_end = std::max(destination.geometry_end, source.geometry_end);
return destination;
}
void fixFinalRoundabout(std::vector<RouteStep> &steps)
{
for (std::size_t propagation_index = steps.size() - 1; propagation_index > 0;
--propagation_index)
{
auto &propagation_step = steps[propagation_index];
if (entersRoundabout(propagation_step.maneuver.instruction))
{
propagation_step.maneuver.exit = 0;
// remember the current name as rotary name in tha case we end in a rotary
if (propagation_step.maneuver.instruction.type == TurnType::EnterRotary ||
propagation_step.maneuver.instruction.type == TurnType::EnterRotaryAtExit)
propagation_step.rotary_name = propagation_step.name;
else if (propagation_step.maneuver.instruction.type ==
TurnType::EnterRoundaboutIntersection ||
propagation_step.maneuver.instruction.type ==
TurnType::EnterRoundaboutIntersectionAtExit)
propagation_step.maneuver.instruction.type = TurnType::EnterRoundabout;
return;
}
// accumulate turn data into the enter instructions
else if (propagation_step.maneuver.instruction.type == TurnType::StayOnRoundabout)
{
// TODO this operates on the data that is in the instructions.
// We are missing out on the final segment after the last stay-on-roundabout
// instruction though. it is not contained somewhere until now
steps[propagation_index - 1] =
forwardInto(std::move(steps[propagation_index - 1]), propagation_step);
invalidateStep(propagation_step);
}
}
}
bool setUpRoundabout(RouteStep &step)
{
// basic entry into a roundabout
// Special case handling, if an entry is directly tied to an exit
const auto instruction = step.maneuver.instruction;
if (instruction.type == TurnType::EnterRotaryAtExit ||
instruction.type == TurnType::EnterRoundaboutAtExit ||
instruction.type == TurnType::EnterRoundaboutIntersectionAtExit)
{
step.maneuver.exit = 1;
// prevent futher special case handling of these two.
if (instruction.type == TurnType::EnterRotaryAtExit)
step.maneuver.instruction.type = TurnType::EnterRotary;
else if (instruction.type == TurnType::EnterRoundaboutAtExit)
step.maneuver.instruction.type = TurnType::EnterRoundabout;
else
step.maneuver.instruction.type = TurnType::EnterRoundaboutIntersection;
}
if (leavesRoundabout(instruction))
{
step.maneuver.exit = 1; // count the otherwise missing exit
// prevent futher special case handling of these two.
if (instruction.type == TurnType::EnterAndExitRotary)
step.maneuver.instruction.type = TurnType::EnterRotary;
else if (instruction.type == TurnType::EnterAndExitRoundabout)
step.maneuver.instruction.type = TurnType::EnterRoundabout;
else
step.maneuver.instruction.type = TurnType::EnterRoundaboutIntersection;
return false;
}
else
{
return true;
}
}
void closeOffRoundabout(const bool on_roundabout,
std::vector<RouteStep> &steps,
const std::size_t step_index)
{
auto &step = steps[step_index];
step.maneuver.exit += 1;
if (!on_roundabout)
{
// We reached a special case that requires the addition of a special route step in the
// beginning. We started in a roundabout, so to announce the exit, we move use the exit
// instruction and move it right to the beginning to make sure to immediately announce the
// exit.
BOOST_ASSERT(leavesRoundabout(steps[1].maneuver.instruction) ||
steps[1].maneuver.instruction.type == TurnType::StayOnRoundabout ||
steps[1].maneuver.instruction.type == TurnType::Suppressed ||
steps[1].maneuver.instruction.type == TurnType::NoTurn);
steps[0].geometry_end = 1;
steps[1].geometry_begin = 0;
steps[1] = forwardInto(steps[1], steps[0]);
steps[1].intersections.erase(steps[1].intersections.begin()); // otherwise we copy the
// source
if (leavesRoundabout(steps[1].maneuver.instruction))
steps[1].maneuver.exit = 1;
steps[0].duration = 0;
steps[0].distance = 0;
const auto exitToEnter = [](const TurnType::Enum type) {
if (TurnType::ExitRotary == type)
return TurnType::EnterRotary;
// if we do not enter the roundabout Intersection, we cannot treat the full traversal as
// a turn. So we switch it up to the roundabout type
else if (type == TurnType::ExitRoundaboutIntersection)
return TurnType::EnterRoundabout;
else
return TurnType::EnterRoundabout;
};
steps[1].maneuver.instruction.type = exitToEnter(step.maneuver.instruction.type);
if (steps[1].maneuver.instruction.type == TurnType::EnterRotary)
steps[1].rotary_name = steps[0].name;
}
// Normal exit from the roundabout, or exit from a previously fixed roundabout. Propagate the
// index back to the entering location and prepare the current silent set of instructions for
// removal.
std::vector<std::size_t> intermediate_steps;
BOOST_ASSERT(!steps[step_index].intersections.empty());
// the very first intersection in the steps represents the location of the turn. Following
// intersections are locations passed along the way
const auto exit_intersection = steps[step_index].intersections.front();
const auto exit_bearing = exit_intersection.bearings[exit_intersection.out];
const auto destination_name = step.name;
const auto destinatino_name_id = step.name_id;
if (step_index > 1)
{
// The very first route-step is head, so we cannot iterate past that one
for (std::size_t propagation_index = step_index - 1; propagation_index > 0;
--propagation_index)
{
auto &propagation_step = steps[propagation_index];
propagation_step = forwardInto(propagation_step, steps[propagation_index + 1]);
if (entersRoundabout(propagation_step.maneuver.instruction))
{
const auto entry_intersection = propagation_step.intersections.front();
// remember rotary name
if (propagation_step.maneuver.instruction.type == TurnType::EnterRotary ||
propagation_step.maneuver.instruction.type == TurnType::EnterRotaryAtExit)
{
propagation_step.rotary_name = propagation_step.name;
}
else if (propagation_step.maneuver.instruction.type ==
TurnType::EnterRoundaboutIntersection ||
propagation_step.maneuver.instruction.type ==
TurnType::EnterRoundaboutIntersectionAtExit)
{
BOOST_ASSERT(!propagation_step.intersections.empty());
const double angle =
turn_angle(util::bearing::reverseBearing(
entry_intersection.bearings[entry_intersection.in]),
exit_bearing);
propagation_step.maneuver.instruction.direction_modifier =
::osrm::util::guidance::getTurnDirection(angle);
}
propagation_step.name = destination_name;
propagation_step.name_id = destinatino_name_id;
invalidateStep(steps[propagation_index + 1]);
break;
}
else
{
invalidateStep(steps[propagation_index + 1]);
}
}
// remove exit
}
}
// elongate a step by another. the data is added either at the front, or the back
RouteStep elongate(RouteStep step, const RouteStep &by_step)
{
BOOST_ASSERT(step.mode == by_step.mode);
step.duration += by_step.duration;
step.distance += by_step.distance;
// by_step comes after step -> we append at the end
if (step.geometry_end == by_step.geometry_begin + 1)
{
step.geometry_end = by_step.geometry_end;
// if we elongate in the back, we only need to copy the intersections to the beginning.
// the bearings remain the same, as the location of the turn doesn't change
step.intersections.insert(
step.intersections.end(), by_step.intersections.begin(), by_step.intersections.end());
}
// by_step comes before step -> we append at the front
else
{
BOOST_ASSERT(step.maneuver.waypoint_type == WaypointType::None &&
by_step.maneuver.waypoint_type == WaypointType::None);
BOOST_ASSERT(by_step.geometry_end == step.geometry_begin + 1);
step.geometry_begin = by_step.geometry_begin;
// elongating in the front changes the location of the maneuver
step.maneuver = by_step.maneuver;
step.intersections.insert(
step.intersections.begin(), by_step.intersections.begin(), by_step.intersections.end());
}
return step;
}
void collapseTurnAt(std::vector<RouteStep> &steps,
const std::size_t two_back_index,
const std::size_t one_back_index,
const std::size_t step_index)
{
BOOST_ASSERT(step_index < steps.size());
BOOST_ASSERT(one_back_index < steps.size());
const auto &current_step = steps[step_index];
const auto &one_back_step = steps[one_back_index];
// This function assumes driving on the right hand side of the streat
const auto bearingsAreReversed = [](const double bearing_in, const double bearing_out) {
// Nearly perfectly reversed angles have a difference close to 180 degrees (straight)
const double left_turn_angle = [&]() {
if (0 <= bearing_out && bearing_out <= bearing_in)
return bearing_in - bearing_out;
return bearing_in + 360 - bearing_out;
}();
return angularDeviation(left_turn_angle, 180) <= 35;
};
BOOST_ASSERT(!one_back_step.intersections.empty() && !current_step.intersections.empty());
// Very Short New Name
if (((collapsable(one_back_step) ||
(isCollapsableInstruction(one_back_step.maneuver.instruction) &&
choiceless(current_step, one_back_step))) &&
!(one_back_step.maneuver.instruction.type == TurnType::Merge)))
// the check against merge is a workaround for motorways
{
BOOST_ASSERT(two_back_index < steps.size());
if (compatible(one_back_step, steps[two_back_index]))
{
BOOST_ASSERT(!one_back_step.intersections.empty());
if (TurnType::Continue == current_step.maneuver.instruction.type ||
(TurnType::Suppressed == current_step.maneuver.instruction.type &&
current_step.maneuver.instruction.direction_modifier !=
DirectionModifier::Straight))
steps[step_index].maneuver.instruction.type = TurnType::Turn;
else if (TurnType::Merge == current_step.maneuver.instruction.type)
{
steps[step_index].maneuver.instruction.direction_modifier =
util::guidance::mirrorDirectionModifier(
steps[step_index].maneuver.instruction.direction_modifier);
steps[step_index].maneuver.instruction.type = TurnType::Turn;
}
else if (TurnType::NewName == current_step.maneuver.instruction.type &&
current_step.maneuver.instruction.direction_modifier !=
DirectionModifier::Straight &&
one_back_step.intersections.front().bearings.size() > 2)
steps[step_index].maneuver.instruction.type = TurnType::Turn;
steps[two_back_index] = elongate(std::move(steps[two_back_index]), one_back_step);
// If the previous instruction asked to continue, the name change will have to
// be changed into a turn
invalidateStep(steps[one_back_index]);
}
}
// very short segment after turn
else if (one_back_step.distance <= MAX_COLLAPSE_DISTANCE &&
isCollapsableInstruction(current_step.maneuver.instruction))
{
// TODO check for lanes (https://github.com/Project-OSRM/osrm-backend/issues/2553)
if (compatible(one_back_step, current_step))
{
steps[one_back_index] = elongate(std::move(steps[one_back_index]), steps[step_index]);
if ((TurnType::Continue == one_back_step.maneuver.instruction.type ||
TurnType::Suppressed == one_back_step.maneuver.instruction.type) &&
current_step.name_id != steps[two_back_index].name_id)
steps[one_back_index].maneuver.instruction.type = TurnType::Turn;
else if (TurnType::Turn == one_back_step.maneuver.instruction.type &&
current_step.name_id == steps[two_back_index].name_id)
{
steps[one_back_index].maneuver.instruction.type = TurnType::Continue;
const auto getBearing = [](bool in, const RouteStep &step) {
const auto index =
in ? step.intersections.front().in : step.intersections.front().out;
return step.intersections.front().bearings[index];
};
// If we Merge onto the same street, we end up with a u-turn in some cases
if (bearingsAreReversed(
util::bearing::reverseBearing(getBearing(true, one_back_step)),
getBearing(false, current_step)))
steps[one_back_index].maneuver.instruction.direction_modifier =
DirectionModifier::UTurn;
}
else if (TurnType::Merge == one_back_step.maneuver.instruction.type &&
current_step.maneuver.instruction.type !=
TurnType::Suppressed) // This suppressed is a check for highways. We might
// need a highway-suppressed to get the turn onto a
// highway...
{
steps[one_back_index].maneuver.instruction.direction_modifier =
util::guidance::mirrorDirectionModifier(
steps[one_back_index].maneuver.instruction.direction_modifier);
}
steps[one_back_index].name = current_step.name;
steps[one_back_index].name_id = current_step.name_id;
invalidateStep(steps[step_index]);
}
}
// Potential U-Turn
else if ((one_back_step.distance <= MAX_COLLAPSE_DISTANCE ||
choiceless(current_step, one_back_step)) &&
bearingsAreReversed(util::bearing::reverseBearing(
one_back_step.intersections.front()
.bearings[one_back_step.intersections.front().in]),
current_step.intersections.front()
.bearings[current_step.intersections.front().out]) &&
compatible(one_back_step, current_step))
{
BOOST_ASSERT(two_back_index < steps.size());
// the simple case is a u-turn that changes directly into the in-name again
const bool direct_u_turn = steps[two_back_index].name == current_step.name;
// however, we might also deal with a dual-collapse scenario in which we have to
// additionall collapse a name-change as well
const bool continues_with_name_change =
(step_index + 1 < steps.size()) &&
(steps[step_index + 1].maneuver.instruction.type == TurnType::UseLane ||
isCollapsableInstruction(steps[step_index + 1].maneuver.instruction));
const bool u_turn_with_name_change =
continues_with_name_change && steps[step_index + 1].name == steps[two_back_index].name;
if (direct_u_turn || u_turn_with_name_change)
{
steps[one_back_index] = elongate(std::move(steps[one_back_index]), steps[step_index]);
invalidateStep(steps[step_index]);
if (u_turn_with_name_change)
{
steps[one_back_index] =
elongate(std::move(steps[one_back_index]), steps[step_index + 1]);
invalidateStep(steps[step_index + 1]); // will be skipped due to the
// continue statement at the
// beginning of this function
}
steps[one_back_index].name = steps[two_back_index].name;
steps[one_back_index].name_id = steps[two_back_index].name_id;
steps[one_back_index].maneuver.instruction.type = TurnType::Continue;
steps[one_back_index].maneuver.instruction.direction_modifier =
DirectionModifier::UTurn;
}
}
}
// Works on steps including silent and invalid instructions in order to do lane anticipation for
// roundabouts which later on get collapsed into a single multi-hop instruction.
std::vector<RouteStep> anticipateLaneChangeForRoundabouts(std::vector<RouteStep> steps)
{
using namespace util::guidance;
using StepIter = decltype(steps)::iterator;
using StepIterRange = std::pair<StepIter, StepIter>;
const auto anticipate_lanes_in_roundabout = [&](StepIterRange roundabout) {
// We do lane anticipation on the roundabout's enter and leave step only.
// TODO: This means, lanes _inside_ the roundabout are ignored at the moment.
auto enter = *roundabout.first;
const auto leave = *roundabout.second;
// Although the enter instruction may be a left/right turn, for right-sided driving the
// roundabout is counter-clockwise and therefore we need to always set it to a left turn.
// FIXME: assumes right-side driving (counter-clockwise roundabout flow)
const auto enter_direction = enter.maneuver.instruction.direction_modifier;
if (util::guidance::isRightTurn(enter.maneuver.instruction))
enter.maneuver.instruction.direction_modifier =
mirrorDirectionModifier(enter_direction);
// a roundabout is a continuous maneuver. We don't switch lanes within a roundabout, as long
// as it can be avoided.
auto enterAndLeave =
anticipateLaneChange({enter, leave}, std::numeric_limits<double>::max());
// Undo flipping direction on a right turn in a right-sided counter-clockwise roundabout.
// FIXME: assumes right-side driving (counter-clockwise roundabout flow)
enterAndLeave[0].maneuver.instruction.direction_modifier = enter_direction;
std::swap(*roundabout.first, enterAndLeave[0]);
std::swap(*roundabout.second, enterAndLeave[1]);
};
forEachRoundabout(begin(steps), end(steps), anticipate_lanes_in_roundabout);
return steps;
}
} // namespace
// Post processing can invalidate some instructions. For example StayOnRoundabout
// is turned into exit counts. These instructions are removed by the following function
std::vector<RouteStep> removeNoTurnInstructions(std::vector<RouteStep> steps)
{
// finally clean up the post-processed instructions.
// Remove all invalid instructions from the set of instructions.
// An instruction is invalid, if its NO_TURN and has WaypointType::None.
// Two valid NO_TURNs exist in each leg in the form of Depart/Arrive
// keep valid instructions
const auto not_is_valid = [](const RouteStep &step) {
return step.maneuver.instruction == TurnInstruction::NO_TURN() &&
step.maneuver.waypoint_type == WaypointType::None;
};
boost::remove_erase_if(steps, not_is_valid);
// the steps should still include depart and arrive at least
BOOST_ASSERT(steps.size() >= 2);
BOOST_ASSERT(steps.front().intersections.size() >= 1);
BOOST_ASSERT(steps.front().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.front().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.front().maneuver.waypoint_type == WaypointType::Depart);
BOOST_ASSERT(steps.back().intersections.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.back().maneuver.waypoint_type == WaypointType::Arrive);
return steps;
}
// Every Step Maneuver consists of the information until the turn.
// This list contains a set of instructions, called silent, which should
// not be part of the final output.
// They are required for maintenance purposes. We can calculate the number
// of exits to pass in a roundabout and the number of intersections
// that we come across.
std::vector<RouteStep> postProcess(std::vector<RouteStep> steps)
{
// the steps should always include the first/last step in form of a location
BOOST_ASSERT(steps.size() >= 2);
if (steps.size() == 2)
return steps;
// Before we invalidate and remove silent instructions, we handle roundabouts (before they're
// getting collapsed into a single multi-hop instruction) by back-propagating exit lane
// constraints already to a roundabout's enter instruction.
steps = anticipateLaneChangeForRoundabouts(std::move(steps));
// Count Street Exits forward
bool on_roundabout = false;
bool has_entered_roundabout = false;
// count the exits forward. if enter/exit roundabout happen both, no further treatment is
// required. We might end up with only one of them (e.g. starting within a roundabout)
// or having a via-point in the roundabout.
// In this case, exits are numbered from the start of the leg.
for (std::size_t step_index = 0; step_index < steps.size(); ++step_index)
{
auto &step = steps[step_index];
const auto instruction = step.maneuver.instruction;
if (entersRoundabout(instruction))
{
has_entered_roundabout = setUpRoundabout(step);
if (has_entered_roundabout && step_index + 1 < steps.size())
steps[step_index + 1].maneuver.exit = step.maneuver.exit;
}
else if (instruction.type == TurnType::StayOnRoundabout)
{
on_roundabout = true;
// increase the exit number we require passing the exit
step.maneuver.exit += 1;
if (step_index + 1 < steps.size())
steps[step_index + 1].maneuver.exit = step.maneuver.exit;
}
else if (leavesRoundabout(instruction))
{
// if (!has_entered_roundabout)
// in case the we are not on a roundabout, the very first instruction
// after the depart will be transformed into a roundabout and become
// the first valid instruction
closeOffRoundabout(has_entered_roundabout, steps, step_index);
has_entered_roundabout = false;
on_roundabout = false;
}
else if (on_roundabout && step_index + 1 < steps.size())
{
steps[step_index + 1].maneuver.exit = step.maneuver.exit;
}
}
// unterminated roundabout
// Move backwards through the instructions until the start and remove the exit number
// A roundabout without exit translates to enter-roundabout.
if (has_entered_roundabout || on_roundabout)
{
fixFinalRoundabout(steps);
}
BOOST_ASSERT(steps.front().intersections.size() >= 1);
BOOST_ASSERT(steps.front().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.front().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.front().maneuver.waypoint_type == WaypointType::Depart);
BOOST_ASSERT(steps.back().intersections.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.back().maneuver.waypoint_type == WaypointType::Arrive);
return removeNoTurnInstructions(std::move(steps));
}
// Post Processing to collapse unnecessary sets of combined instructions into a single one
std::vector<RouteStep> collapseTurns(std::vector<RouteStep> steps)
{
if (steps.size() <= 2)
return steps;
// Get the previous non-invalid instruction
const auto getPreviousIndex = [&steps](std::size_t index) {
BOOST_ASSERT(index > 0);
BOOST_ASSERT(index < steps.size());
--index;
while (index > 0 && steps[index].maneuver.instruction.type == TurnType::NoTurn)
--index;
return index;
};
const auto getPreviousNameIndex = [&steps](std::size_t index) {
BOOST_ASSERT(index > 0);
BOOST_ASSERT(index < steps.size());
--index; // make sure to skip the current name
while (index > 0 && steps[index].name_id == EMPTY_NAMEID)
{
--index;
}
return index;
};
// a series of turns is only possible to collapse if its only name changes and suppressed turns.
const auto canCollapseAll = [&steps](std::size_t index, const std::size_t end_index) {
BOOST_ASSERT(end_index <= steps.size());
for (; index < end_index; ++index)
{
if (steps[index].maneuver.instruction.type != TurnType::Suppressed &&
steps[index].maneuver.instruction.type != TurnType::NewName)
return false;
}
return true;
};
// first and last instructions are waypoints that cannot be collapsed
for (std::size_t step_index = 1; step_index + 1 < steps.size(); ++step_index)
{
const auto &current_step = steps[step_index];
if (current_step.maneuver.instruction.type == TurnType::NoTurn)
continue;
const auto one_back_index = getPreviousIndex(step_index);
BOOST_ASSERT(one_back_index < steps.size());
const auto &one_back_step = steps[one_back_index];
// how long has a name change to be so that we announce it, even as a bridge?
const constexpr auto name_segment_cutoff_length = 100;
const auto isBasicNameChange = [](const RouteStep &step) {
return step.intersections.size() == 1 &&
step.intersections.front().bearings.size() == 2 &&
DirectionModifier::Straight == step.maneuver.instruction.direction_modifier;
};
// Handle sliproads from motorways in urban areas, save from modifying depart, since
// TurnType::Sliproad != TurnType::NoTurn
if (one_back_step.maneuver.instruction.type == TurnType::Sliproad)
{
// Handle possible u-turns between highways that look like slip-roads
if (steps[getPreviousIndex(one_back_index)].name_id == steps[step_index].name_id &&
steps[step_index].name_id != EMPTY_NAMEID)
{
steps[one_back_index].maneuver.instruction.type = TurnType::Continue;
}
else
{
steps[one_back_index].maneuver.instruction.type = TurnType::Turn;
}
if (compatible(one_back_step, current_step))
{
steps[one_back_index] =
elongate(std::move(steps[one_back_index]), steps[step_index]);
steps[one_back_index].name_id = steps[step_index].name_id;
steps[one_back_index].name = steps[step_index].name;
const auto exit_intersection = steps[step_index].intersections.front();
const auto exit_bearing = exit_intersection.bearings[exit_intersection.out];
const auto entry_intersection = steps[one_back_index].intersections.front();
const auto entry_bearing = entry_intersection.bearings[entry_intersection.in];
const double angle =
turn_angle(util::bearing::reverseBearing(entry_bearing), exit_bearing);
steps[one_back_index].maneuver.instruction.direction_modifier =
::osrm::util::guidance::getTurnDirection(angle);
invalidateStep(steps[step_index]);
}
}
// Due to empty segments, we can get name-changes from A->A
// These have to be handled in post-processing
else if (isCollapsableInstruction(current_step.maneuver.instruction) &&
current_step.maneuver.instruction.type != TurnType::Suppressed &&
steps[getPreviousNameIndex(step_index)].name == current_step.name &&
canCollapseAll(getPreviousNameIndex(step_index) + 1, step_index + 1))
{
BOOST_ASSERT(step_index > 0);
const std::size_t last_available_name_index = getPreviousNameIndex(step_index);
for (std::size_t index = last_available_name_index + 1; index <= step_index; ++index)
{
steps[last_available_name_index] =
elongate(std::move(steps[last_available_name_index]), steps[index]);
invalidateStep(steps[index]);
}
}
// If we look at two consecutive name changes, we can check for a name oszillation.
// A name oszillation changes from name A shortly to name B and back to A.
// In these cases, the name change will be suppressed.
else if (one_back_index > 0 && compatible(current_step, one_back_step) &&
isCollapsableInstruction(current_step.maneuver.instruction) &&
isCollapsableInstruction(one_back_step.maneuver.instruction))
{
const auto two_back_index = getPreviousIndex(one_back_index);
BOOST_ASSERT(two_back_index < steps.size());
// valid, since one_back is collapsable:
const auto &coming_from_name = steps[two_back_index].name;
if (current_step.name == coming_from_name)
{
if (compatible(one_back_step, steps[two_back_index]))
{
steps[two_back_index] =
elongate(elongate(std::move(steps[two_back_index]), steps[one_back_index]),
steps[step_index]);
invalidateStep(steps[one_back_index]);
invalidateStep(steps[step_index]);
}
// TODO discuss: we could think about changing the new-name to a pure notification
// about mode changes
}
else if (nameSegmentLength(one_back_index, steps) < name_segment_cutoff_length &&
isBasicNameChange(one_back_step) && isBasicNameChange(current_step))
{
steps[two_back_index] =
elongate(std::move(steps[two_back_index]), steps[one_back_index]);
invalidateStep(steps[one_back_index]);
if (nameSegmentLength(step_index, steps) < name_segment_cutoff_length)
{
steps[two_back_index] =
elongate(std::move(steps[two_back_index]), steps[step_index]);
invalidateStep(steps[step_index]);
}
}
else if (choiceless(current_step, one_back_step) ||
one_back_step.distance <= MAX_COLLAPSE_DISTANCE)
{
// check for one of the multiple collapse scenarios and, if possible, collapse the
// turn
const auto two_back_index = getPreviousIndex(one_back_index);
BOOST_ASSERT(two_back_index < steps.size());
collapseTurnAt(steps, two_back_index, one_back_index, step_index);
}
}
else if (one_back_index > 0 && (one_back_step.distance <= MAX_COLLAPSE_DISTANCE ||
choiceless(current_step, one_back_step)))
{
// check for one of the multiple collapse scenarios and, if possible, collapse the turn
const auto two_back_index = getPreviousIndex(one_back_index);
BOOST_ASSERT(two_back_index < steps.size());
collapseTurnAt(steps, two_back_index, one_back_index, step_index);
}
}
// handle final sliproad
if (steps.size() >= 3 &&
steps[steps.size() - 2].maneuver.instruction.type == TurnType::Sliproad)
{
steps[steps.size() - 2].maneuver.instruction.type = TurnType::Turn;
}
BOOST_ASSERT(steps.front().intersections.size() >= 1);
BOOST_ASSERT(steps.front().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.front().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.front().maneuver.waypoint_type == WaypointType::Depart);
BOOST_ASSERT(steps.back().intersections.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.back().maneuver.waypoint_type == WaypointType::Arrive);
return removeNoTurnInstructions(std::move(steps));
}
// Doing this step in post-processing provides a few challenges we cannot overcome.
// The removal of an initial step imposes some copy overhead in the steps, moving all later
// steps to the front. In addition, we cannot reduce the travel time that is accumulated at a
// different location.
// As a direct implication, we have to keep the time of the initial/final turns (which adds a
// few seconds of inaccuracy at both ends. This is acceptable, however, since the turn should
// usually not be as relevant.
void trimShortSegments(std::vector<RouteStep> &steps, LegGeometry &geometry)
{
if (steps.size() < 2 || geometry.locations.size() <= 2)
return;
// if phantom node is located at the connection of two segments, either one can be selected
// as
// turn
//
// a --- b
// |
// c
//
// If a route from b to c is requested, both a--b and b--c could be selected as start
// segment.
// In case of a--b, we end up with an unwanted turn saying turn-right onto b-c.
// These cases start off with an initial segment which is of zero length.
// We have to be careful though, since routing that starts in a roundabout has a valid.
// To catch these cases correctly, we have to perform trimming prior to the post-processing
BOOST_ASSERT(geometry.locations.size() >= steps.size());
// Look for distances under 1m
const bool zero_length_step = steps.front().distance <= 1 && steps.size() > 2;
const bool duplicated_coordinate = util::coordinate_calculation::haversineDistance(
geometry.locations[0], geometry.locations[1]) <= 1;
if (zero_length_step || duplicated_coordinate)
{
// fixup the coordinate
geometry.locations.erase(geometry.locations.begin());
geometry.annotations.erase(geometry.annotations.begin());
geometry.osm_node_ids.erase(geometry.osm_node_ids.begin());
// remove the initial distance value
geometry.segment_distances.erase(geometry.segment_distances.begin());
// We have to adjust the first step both for its name and the bearings
if (zero_length_step)
{
// move offsets to front
BOOST_ASSERT(geometry.segment_offsets[1] == 1);
// geometry offsets have to be adjusted. Move all offsets to the front and reduce by
// one. (This is an inplace forward one and reduce by one)
std::transform(geometry.segment_offsets.begin() + 1,
geometry.segment_offsets.end(),
geometry.segment_offsets.begin(),
[](const std::size_t val) { return val - 1; });
geometry.segment_offsets.pop_back();
const auto &current_depart = steps.front();
auto &designated_depart = *(steps.begin() + 1);
// FIXME this is required to be consistent with the route durations. The initial
// turn is not actually part of the route, though
designated_depart.duration += current_depart.duration;
// update initial turn direction/bearings. Due to the duplicated first coordinate,
// the initial bearing is invalid
designated_depart.maneuver.waypoint_type = WaypointType::Depart;
designated_depart.maneuver.bearing_before = 0;
designated_depart.maneuver.instruction = TurnInstruction::NO_TURN();
// we need to make this conform with the intersection format for the first intersection
auto &first_intersection = designated_depart.intersections.front();
designated_depart.intersections.front().lanes = util::guidance::LaneTupel();
designated_depart.intersections.front().lane_description.clear();
first_intersection.bearings = {first_intersection.bearings[first_intersection.out]};
first_intersection.entry = {true};
first_intersection.in = Intersection::NO_INDEX;
first_intersection.out = 0;
// finally remove the initial (now duplicated move)
steps.erase(steps.begin());
}
else
{
// we need to make this at least 1 because we will substract 1
// from all offsets at the end of the loop.
steps.front().geometry_begin = 1;
// reduce all offsets by one (inplace)
std::transform(geometry.segment_offsets.begin(),
geometry.segment_offsets.end(),
geometry.segment_offsets.begin(),
[](const std::size_t val) { return val - 1; });
}
// and update the leg geometry indices for the removed entry
std::for_each(steps.begin(), steps.end(), [](RouteStep &step) {
--step.geometry_begin;
--step.geometry_end;
});
auto &first_step = steps.front();
// we changed the geometry, we need to recalculate the bearing
auto bearing = std::round(util::coordinate_calculation::bearing(
geometry.locations[first_step.geometry_begin],
geometry.locations[first_step.geometry_begin + 1]));
first_step.maneuver.bearing_after = bearing;
first_step.intersections.front().bearings.front() = bearing;
}
BOOST_ASSERT(steps.front().intersections.size() >= 1);
BOOST_ASSERT(steps.front().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.front().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.front().maneuver.waypoint_type == WaypointType::Depart);
BOOST_ASSERT(steps.back().intersections.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.back().maneuver.waypoint_type == WaypointType::Arrive);
// make sure we still have enough segments
if (steps.size() < 2 || geometry.locations.size() == 2)
return;
BOOST_ASSERT(geometry.locations.size() >= steps.size());
auto &next_to_last_step = *(steps.end() - 2);
// in the end, the situation with the roundabout cannot occur. As a result, we can remove
// all zero-length instructions
if (next_to_last_step.distance <= 1 && steps.size() > 2)
{
geometry.locations.pop_back();
geometry.annotations.pop_back();
geometry.osm_node_ids.pop_back();
geometry.segment_offsets.pop_back();
BOOST_ASSERT(geometry.segment_distances.back() <= 1);
geometry.segment_distances.pop_back();
next_to_last_step.maneuver.waypoint_type = WaypointType::Arrive;
next_to_last_step.maneuver.instruction = TurnInstruction::NO_TURN();
next_to_last_step.maneuver.bearing_after = 0;
next_to_last_step.intersections.front().lanes = util::guidance::LaneTupel();
next_to_last_step.intersections.front().lane_description.clear();
BOOST_ASSERT(next_to_last_step.intersections.size() == 1);
auto &last_intersection = next_to_last_step.intersections.back();
last_intersection.bearings = {last_intersection.bearings[last_intersection.in]};
last_intersection.entry = {true};
last_intersection.out = Intersection::NO_INDEX;
last_intersection.in = 0;
steps.pop_back();
// Because we eliminated a really short segment, it was probably
// near an intersection. The convention is *not* to make the
// turn, so the `arrive` instruction should be on the same road
// as the segment before it. Thus, we have to copy the names
// and travel modes from the new next_to_last step.
auto &new_next_to_last = *(steps.end() - 2);
next_to_last_step.name = new_next_to_last.name;
next_to_last_step.name_id = new_next_to_last.name_id;
next_to_last_step.mode = new_next_to_last.mode;
// the geometry indices of the last step are already correct;
}
else if (util::coordinate_calculation::haversineDistance(
geometry.locations[geometry.locations.size() - 2],
geometry.locations[geometry.locations.size() - 1]) <= 1)
{
// correct steps but duplicated coordinate in the end.
// This can happen if the last coordinate snaps to a node in the unpacked geometry
geometry.locations.pop_back();
geometry.annotations.pop_back();
geometry.segment_offsets.back()--;
// since the last geometry includes the location of arrival, the arrival instruction
// geometry overlaps with the previous segment
BOOST_ASSERT(next_to_last_step.geometry_end == steps.back().geometry_begin + 1);
BOOST_ASSERT(next_to_last_step.geometry_begin < next_to_last_step.geometry_end);
next_to_last_step.geometry_end--;
auto &last_step = steps.back();
last_step.geometry_begin--;
last_step.geometry_end--;
BOOST_ASSERT(next_to_last_step.geometry_end == last_step.geometry_begin + 1);
BOOST_ASSERT(last_step.geometry_begin == last_step.geometry_end - 1);
BOOST_ASSERT(next_to_last_step.geometry_end >= 2);
// we changed the geometry, we need to recalculate the bearing
auto bearing = std::round(util::coordinate_calculation::bearing(
geometry.locations[next_to_last_step.geometry_end - 2],
geometry.locations[last_step.geometry_begin]));
last_step.maneuver.bearing_before = bearing;
last_step.intersections.front().bearings.front() = util::bearing::reverseBearing(bearing);
}
BOOST_ASSERT(steps.front().intersections.size() >= 1);
BOOST_ASSERT(steps.front().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.front().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.front().maneuver.waypoint_type == WaypointType::Depart);
BOOST_ASSERT(steps.back().intersections.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.back().maneuver.waypoint_type == WaypointType::Arrive);
}
// assign relative locations to depart/arrive instructions
std::vector<RouteStep> assignRelativeLocations(std::vector<RouteStep> steps,
const LegGeometry &leg_geometry,
const PhantomNode &source_node,
const PhantomNode &target_node)
{
// We report the relative position of source/target to the road only within a range that is
// sufficiently different but not full of the path
BOOST_ASSERT(steps.size() >= 2);
BOOST_ASSERT(leg_geometry.locations.size() >= 2);
const constexpr double MINIMAL_RELATIVE_DISTANCE = 5., MAXIMAL_RELATIVE_DISTANCE = 300.;
const auto distance_to_start = util::coordinate_calculation::haversineDistance(
source_node.input_location, leg_geometry.locations[0]);
const auto initial_modifier =
distance_to_start >= MINIMAL_RELATIVE_DISTANCE &&
distance_to_start <= MAXIMAL_RELATIVE_DISTANCE
? angleToDirectionModifier(util::coordinate_calculation::computeAngle(
source_node.input_location, leg_geometry.locations[0], leg_geometry.locations[1]))
: extractor::guidance::DirectionModifier::UTurn;
steps.front().maneuver.instruction.direction_modifier = initial_modifier;
const auto distance_from_end = util::coordinate_calculation::haversineDistance(
target_node.input_location, leg_geometry.locations.back());
const auto final_modifier =
distance_from_end >= MINIMAL_RELATIVE_DISTANCE &&
distance_from_end <= MAXIMAL_RELATIVE_DISTANCE
? angleToDirectionModifier(util::coordinate_calculation::computeAngle(
leg_geometry.locations[leg_geometry.locations.size() - 2],
leg_geometry.locations[leg_geometry.locations.size() - 1],
target_node.input_location))
: extractor::guidance::DirectionModifier::UTurn;
steps.back().maneuver.instruction.direction_modifier = final_modifier;
BOOST_ASSERT(steps.front().intersections.size() >= 1);
BOOST_ASSERT(steps.front().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.front().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.front().maneuver.waypoint_type == WaypointType::Depart);
BOOST_ASSERT(steps.back().intersections.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().bearings.size() == 1);
BOOST_ASSERT(steps.back().intersections.front().entry.size() == 1);
BOOST_ASSERT(steps.back().maneuver.waypoint_type == WaypointType::Arrive);
return steps;
}
LegGeometry resyncGeometry(LegGeometry leg_geometry, const std::vector<RouteStep> &steps)
{
// The geometry uses an adjacency array-like structure for representation.
// To sync it back up with the steps, we cann add a segment for every step.
leg_geometry.segment_offsets.clear();
leg_geometry.segment_distances.clear();
leg_geometry.segment_offsets.push_back(0);
for (const auto &step : steps)
{
leg_geometry.segment_distances.push_back(step.distance);
// the leg geometry does not follow the begin/end-convetion. So we have to subtract one
// to get the back-index.
leg_geometry.segment_offsets.push_back(step.geometry_end - 1);
}
// remove the data from the reached-target step again
leg_geometry.segment_offsets.pop_back();
leg_geometry.segment_distances.pop_back();
return leg_geometry;
}
std::vector<RouteStep> buildIntersections(std::vector<RouteStep> steps)
{
std::size_t last_valid_instruction = 0;
for (std::size_t step_index = 0; step_index < steps.size(); ++step_index)
{
auto &step = steps[step_index];
const auto instruction = step.maneuver.instruction;
if (instruction.type == TurnType::Suppressed)
{
// count intersections. We cannot use exit, since intersections can follow directly
// after a roundabout
steps[last_valid_instruction] = elongate(steps[last_valid_instruction], step);
step.maneuver.instruction = TurnInstruction::NO_TURN();
}
else if (!isSilent(instruction))
{
// End of road is a turn that helps to identify the location of a turn. If the turn does
// not pass by any oter intersections, the end-of-road characteristic does not improve
// the instructions.
// Here we reduce the verbosity of our output by reducing end-of-road emissions in cases
// where no intersections have been passed in between.
// Since the instruction is located at the beginning of a step, we need to check the
// previous instruction.
if (instruction.type == TurnType::EndOfRoad)
{
BOOST_ASSERT(step_index > 0 && step_index + 1 < steps.size());
const auto &previous_step = steps[last_valid_instruction];
if (previous_step.intersections.size() < MIN_END_OF_ROAD_INTERSECTIONS)
step.maneuver.instruction.type = TurnType::Turn;
}
// Remember the last non silent instruction
last_valid_instruction = step_index;
}
}
return removeNoTurnInstructions(std::move(steps));
}
std::vector<RouteStep> collapseUseLane(std::vector<RouteStep> steps)
{
const auto containsTag = [](const extractor::guidance::TurnLaneType::Mask mask,
const extractor::guidance::TurnLaneType::Mask tag) {
return (mask & tag) != extractor::guidance::TurnLaneType::empty;
};
const auto getPreviousIndex = [&steps](std::size_t index) {
BOOST_ASSERT(index > 0);
BOOST_ASSERT(index < steps.size());
--index;
while (index > 0 && steps[index].maneuver.instruction.type == TurnType::NoTurn)
--index;
return index;
};
const auto canCollapeUseLane =
[containsTag](const util::guidance::LaneTupel lanes,
extractor::guidance::TurnLaneDescription lane_description) {
// the lane description is given left to right, lanes are counted from the right.
// Therefore we access the lane description yousing the reverse iterator
if (lanes.first_lane_from_the_right > 0 &&
containsTag(*(lane_description.rbegin() + (lanes.first_lane_from_the_right - 1)),
(extractor::guidance::TurnLaneType::straight |
extractor::guidance::TurnLaneType::none)))
return false;
const auto lane_to_the_right = lanes.first_lane_from_the_right + lanes.lanes_in_turn;
if (lane_to_the_right < boost::numeric_cast<int>(lane_description.size()) &&
containsTag(*(lane_description.rbegin() + lane_to_the_right),
(extractor::guidance::TurnLaneType::straight |
extractor::guidance::TurnLaneType::none)))
return false;
return true;
};
for (std::size_t step_index = 1; step_index < steps.size(); ++step_index)
{
const auto &step = steps[step_index];
if (step.maneuver.instruction.type == TurnType::UseLane &&
canCollapeUseLane(step.intersections.front().lanes,
step.intersections.front().lane_description))
{
const auto previous = getPreviousIndex(step_index);
steps[previous] = elongate(steps[previous], steps[step_index]);
//elongate(steps[step_index-1], steps[step_index]);
invalidateStep(steps[step_index]);
}
}
return removeNoTurnInstructions(std::move(steps));
}
} // namespace guidance
} // namespace engine
} // namespace osrm