DirectInfrastructurePerception.java
package org.opentrafficsim.road.gtu.lane.perception.categories;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.WeakHashMap;
import org.djunits.value.vdouble.scalar.Length;
import org.djutils.exceptions.Throw;
import org.djutils.exceptions.Try;
import org.opentrafficsim.base.TimeStampedObject;
import org.opentrafficsim.base.parameters.ParameterException;
import org.opentrafficsim.core.gtu.GTUException;
import org.opentrafficsim.core.gtu.RelativePosition;
import org.opentrafficsim.core.network.LateralDirectionality;
import org.opentrafficsim.core.network.NetworkException;
import org.opentrafficsim.core.network.route.Route;
import org.opentrafficsim.road.gtu.lane.perception.InfrastructureLaneChangeInfo;
import org.opentrafficsim.road.gtu.lane.perception.LanePerception;
import org.opentrafficsim.road.gtu.lane.perception.LaneStructureRecord;
import org.opentrafficsim.road.gtu.lane.perception.RelativeLane;
import org.opentrafficsim.road.network.lane.Lane;
import org.opentrafficsim.road.network.lane.object.sensor.SingleSensor;
import org.opentrafficsim.road.network.lane.object.sensor.SinkSensor;
import org.opentrafficsim.road.network.speed.SpeedLimitProspect;
import org.opentrafficsim.road.network.speed.SpeedLimitTypes;
/**
* Perceives information concerning the infrastructure, including slits, lanes, speed limits and road markings.
* <p>
* Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
* BSD-style license. See <a href="http://opentrafficsim.org/docs/current/license.html">OpenTrafficSim License</a>.
* <p>
* @version $Revision$, $LastChangedDate$, by $Author$, initial version Jul 14, 2016 <br>
* @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
* @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
* @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
*/
public class DirectInfrastructurePerception extends LaneBasedAbstractPerceptionCategory implements InfrastructurePerception
{
/** */
private static final long serialVersionUID = 20160811L;
/** Infrastructure lane change info per relative lane. */
private final Map<RelativeLane, TimeStampedObject<SortedSet<InfrastructureLaneChangeInfo>>> infrastructureLaneChangeInfo =
new HashMap<>();
/** Speed limit prospect per relative lane. */
private Map<RelativeLane, TimeStampedObject<SpeedLimitProspect>> speedLimitProspect = new HashMap<>();
/** Legal Lane change possibilities per relative lane and lateral direction. */
private final Map<RelativeLane,
Map<LateralDirectionality, TimeStampedObject<LaneChangePossibility>>> legalLaneChangePossibility = new HashMap<>();
/** Physical Lane change possibilities per relative lane and lateral direction. */
private final Map<RelativeLane,
Map<LateralDirectionality, TimeStampedObject<LaneChangePossibility>>> physicalLaneChangePossibility =
new HashMap<>();
/** Cross-section. */
private TimeStampedObject<SortedSet<RelativeLane>> crossSection;
/** Cache for anyNextOk. */
private final Map<LaneStructureRecord, Boolean> anyNextOkCache = new WeakHashMap<>();
/** Set of records with accessible end as they are cut off. */
private final Set<LaneStructureRecord> cutOff = new LinkedHashSet<>();
/** Root. */
private LaneStructureRecord root;
/** Lanes registered to the GTU used to check if an update is required. */
private Set<Lane> lanes;
/** Route. */
private Route route;
/**
* @param perception LanePerception; perception
*/
public DirectInfrastructurePerception(final LanePerception perception)
{
super(perception);
}
/** {@inheritDoc} */
@Override
public void updateAll() throws GTUException, ParameterException
{
updateCrossSection();
// clean-up
Set<RelativeLane> cs = getCrossSection();
this.infrastructureLaneChangeInfo.keySet().retainAll(cs);
this.legalLaneChangePossibility.keySet().retainAll(cs);
this.physicalLaneChangePossibility.keySet().retainAll(cs);
this.speedLimitProspect.keySet().retainAll(cs);
// only if required
LaneStructureRecord newRoot = getPerception().getLaneStructure().getRootRecord();
if (this.root == null || !newRoot.equals(this.root)
|| !this.lanes.equals(getPerception().getGtu().positions(RelativePosition.REFERENCE_POSITION).keySet())
|| !Objects.equals(this.route, getPerception().getGtu().getStrategicalPlanner().getRoute())
|| this.cutOff.stream().filter((record) -> !record.isCutOffEnd()).count() > 0)
{
this.cutOff.clear();
this.root = newRoot;
this.lanes = getPerception().getGtu().positions(RelativePosition.REFERENCE_POSITION).keySet();
this.route = getPerception().getGtu().getStrategicalPlanner().getRoute();
this.speedLimitProspect.clear();
for (RelativeLane lane : getCrossSection())
{
updateInfrastructureLaneChangeInfo(lane);
updateLegalLaneChangePossibility(lane, LateralDirectionality.LEFT);
updateLegalLaneChangePossibility(lane, LateralDirectionality.RIGHT);
updatePhysicalLaneChangePossibility(lane, LateralDirectionality.LEFT);
updatePhysicalLaneChangePossibility(lane, LateralDirectionality.RIGHT);
}
}
// speed limit prospect
for (RelativeLane lane : getCrossSection())
{
updateSpeedLimitProspect(lane);
}
for (RelativeLane lane : getCrossSection())
{
if (!this.infrastructureLaneChangeInfo.containsKey(lane))
{
updateInfrastructureLaneChangeInfo(lane); // new lane in cross section
updateLegalLaneChangePossibility(lane, LateralDirectionality.LEFT);
updateLegalLaneChangePossibility(lane, LateralDirectionality.RIGHT);
updatePhysicalLaneChangePossibility(lane, LateralDirectionality.LEFT);
updatePhysicalLaneChangePossibility(lane, LateralDirectionality.RIGHT);
}
}
}
/** {@inheritDoc} */
@Override
public final void updateInfrastructureLaneChangeInfo(final RelativeLane lane) throws GTUException, ParameterException
{
if (this.infrastructureLaneChangeInfo.containsKey(lane)
&& this.infrastructureLaneChangeInfo.get(lane).getTimestamp().equals(getTimestamp()))
{
// already done at this time
return;
}
updateCrossSection();
// start at requested lane
SortedSet<InfrastructureLaneChangeInfo> resultSet = new TreeSet<>();
LaneStructureRecord record = getPerception().getLaneStructure().getFirstRecord(lane);
try
{
record = getPerception().getLaneStructure().getFirstRecord(lane);
if (!record.allowsRoute(getGtu().getStrategicalPlanner().getRoute(), getGtu().getGTUType()))
{
resultSet.add(InfrastructureLaneChangeInfo.fromInaccessibleLane(record.isDeadEnd()));
this.infrastructureLaneChangeInfo.put(lane, new TimeStampedObject<>(resultSet, getTimestamp()));
return;
}
}
catch (NetworkException exception)
{
throw new GTUException("Route has no destination.", exception);
}
Map<LaneStructureRecord, InfrastructureLaneChangeInfo> currentSet = new LinkedHashMap<>();
Map<LaneStructureRecord, InfrastructureLaneChangeInfo> nextSet = new LinkedHashMap<>();
RelativePosition front = getPerception().getGtu().getFront();
currentSet.put(record,
new InfrastructureLaneChangeInfo(0, record, front, record.isDeadEnd(), LateralDirectionality.NONE));
while (!currentSet.isEmpty())
{
// move lateral
nextSet.putAll(currentSet);
for (LaneStructureRecord laneRecord : currentSet.keySet())
{
while (laneRecord.legalLeft() && !nextSet.containsKey(laneRecord.getLeft()))
{
InfrastructureLaneChangeInfo info =
nextSet.get(laneRecord).left(laneRecord.getLeft(), front, laneRecord.getLeft().isDeadEnd());
nextSet.put(laneRecord.getLeft(), info);
laneRecord = laneRecord.getLeft();
}
}
for (LaneStructureRecord laneRecord : currentSet.keySet())
{
while (laneRecord.legalRight() && !nextSet.containsKey(laneRecord.getRight()))
{
InfrastructureLaneChangeInfo info =
nextSet.get(laneRecord).right(laneRecord.getRight(), front, laneRecord.getRight().isDeadEnd());
nextSet.put(laneRecord.getRight(), info);
laneRecord = laneRecord.getRight();
}
}
// move longitudinal
currentSet = nextSet;
nextSet = new LinkedHashMap<>();
InfrastructureLaneChangeInfo bestOk = null;
InfrastructureLaneChangeInfo bestNotOk = null;
boolean deadEnd = false;
for (LaneStructureRecord laneRecord : currentSet.keySet())
{
boolean anyOk = Try.assign(() -> anyNextOk(laneRecord), "Route has no destination.");
if (anyOk)
{
// add to nextSet
for (LaneStructureRecord next : laneRecord.getNext())
{
try
{
if (next.allowsRoute(getGtu().getStrategicalPlanner().getRoute(), getGtu().getGTUType()))
{
InfrastructureLaneChangeInfo prev = currentSet.get(laneRecord);
InfrastructureLaneChangeInfo info =
new InfrastructureLaneChangeInfo(prev.getRequiredNumberOfLaneChanges(), next, front,
next.isDeadEnd(), prev.getLateralDirectionality());
nextSet.put(next, info);
}
}
catch (NetworkException exception)
{
throw new RuntimeException("Network exception while considering route on next lane.", exception);
}
}
// take best ok
if (bestOk == null || currentSet.get(laneRecord).getRequiredNumberOfLaneChanges() < bestOk
.getRequiredNumberOfLaneChanges())
{
bestOk = currentSet.get(laneRecord);
}
}
else
{
// take best not ok
deadEnd = deadEnd || currentSet.get(laneRecord).isDeadEnd();
if (bestNotOk == null || currentSet.get(laneRecord).getRequiredNumberOfLaneChanges() < bestNotOk
.getRequiredNumberOfLaneChanges())
{
bestNotOk = currentSet.get(laneRecord);
}
}
}
if (bestOk == null)
{
// if (lane.isCurrent())
// {
// // on the current lane, we need something to drive to
// throw new GTUException("No lane was found on which to continue from link "
// + currentSet.keySet().iterator().next().getLane().getParentLink().getId() + " for route "
// + getGtu().getStrategicalPlanner().getRoute().getId());
// }
// else
// {
// empty set on other lanes permissible, on adjacent lanes, we might not be able to continue on our route
break;
// }
}
// if there are lanes that are not okay and only -further- lanes that are ok, we need to change to one of the ok's
if (bestNotOk != null && bestOk.getRequiredNumberOfLaneChanges() > bestNotOk.getRequiredNumberOfLaneChanges())
{
bestOk.setDeadEnd(deadEnd);
resultSet.add(bestOk);
}
currentSet = nextSet;
nextSet = new LinkedHashMap<>();
}
// save
this.infrastructureLaneChangeInfo.put(lane, new TimeStampedObject<>(resultSet, getTimestamp()));
}
/**
* Returns whether the given record end is ok to pass. If not, a lane change is required before this end. The method will
* also return true if the next node is the end node of the route, if the lane is cut off due to limited perception range,
* or when there is a {@code SinkSensor} on the lane.
* @param record LaneStructureRecord; checked record
* @return whether the given record end is ok to pass
* @throws NetworkException if destination could not be obtained
* @throws GTUException if the GTU could not be obtained
*/
private boolean anyNextOk(final LaneStructureRecord record) throws NetworkException, GTUException
{
if (record.isCutOffEnd())
{
this.cutOff.add(record);
return true; // always ok if cut-off
}
// check cache
Boolean ok = this.anyNextOkCache.get(record);
if (ok != null)
{
return ok;
}
// sink
for (SingleSensor s : record.getLane().getSensors())
{
if (s instanceof SinkSensor)
{
this.anyNextOkCache.put(record, true);
return true; // ok towards sink
}
}
// check destination
Route currentRoute = getGtu().getStrategicalPlanner().getRoute();
try
{
if (currentRoute != null && currentRoute.destinationNode().equals(record.getToNode()))
{
this.anyNextOkCache.put(record, true);
return true;
}
}
catch (NetworkException exception)
{
throw new RuntimeException("Could not determine destination node.", exception);
}
// check dead-end
if (record.getNext().isEmpty())
{
this.anyNextOkCache.put(record, false);
return false; // never ok if dead-end
}
// check if we have a route
if (currentRoute == null)
{
this.anyNextOkCache.put(record, true);
return true; // if no route assume ok, i.e. simple networks without routes
}
// finally check route
ok = record.allowsRouteAtEnd(currentRoute, getGtu().getGTUType());
this.anyNextOkCache.put(record, ok);
return ok;
}
/** {@inheritDoc} */
@Override
public final void updateSpeedLimitProspect(final RelativeLane lane) throws GTUException, ParameterException
{
updateCrossSection();
checkLaneIsInCrossSection(lane);
TimeStampedObject<SpeedLimitProspect> tsSlp = this.speedLimitProspect.get(lane);
SpeedLimitProspect slp;
if (tsSlp != null)
{
slp = tsSlp.getObject();
slp.update(getGtu().getOdometer());
}
else
{
slp = new SpeedLimitProspect(getGtu().getOdometer());
slp.addSpeedInfo(Length.ZERO, SpeedLimitTypes.MAX_VEHICLE_SPEED, getGtu().getMaximumSpeed(), getGtu());
}
try
{
Lane laneObj = getGtu().getReferencePosition().getLane();
if (!slp.containsAddSource(laneObj))
{
slp.addSpeedInfo(Length.ZERO, SpeedLimitTypes.FIXED_SIGN, laneObj.getSpeedLimit(getGtu().getGTUType()),
laneObj);
}
}
catch (NetworkException exception)
{
throw new RuntimeException("Could not obtain speed limit from lane for perception.", exception);
}
this.speedLimitProspect.put(lane, new TimeStampedObject<>(slp, getTimestamp()));
}
/** {@inheritDoc} */
@Override
public final void updateLegalLaneChangePossibility(final RelativeLane lane, final LateralDirectionality lat)
throws GTUException, ParameterException
{
updateLaneChangePossibility(lane, lat, true, this.legalLaneChangePossibility);
}
/** {@inheritDoc} */
@Override
public final void updatePhysicalLaneChangePossibility(final RelativeLane lane, final LateralDirectionality lat)
throws GTUException, ParameterException
{
updateLaneChangePossibility(lane, lat, false, this.physicalLaneChangePossibility);
}
/**
* Updates the distance over which lane changes remains legally or physically possible.
* @param lane RelativeLane; lane from which the lane change possibility is requested
* @param lat LateralDirectionality; LEFT or RIGHT, null not allowed
* @param legal boolean; legal, or physical otherwise
* @param possibilityMap
* Map<RelativeLane,Map<LateralDirectionality,TimeStampedObject<LaneChangePossibility>>>;
* Map<RelativeLane,Map<LateralDirectionality,TimeStampedObject<LaneChangePossibility>>>;
* Map<RelativeLane,Map<LateralDirectionality,TimeStampedObject<LaneChangePossibility>>>;
* Map<RelativeLane,Map<LateralDirectionality,TimeStampedObject<LaneChangePossibility>>>; legal
* or physical possibility map
* @throws GTUException if the GTU was not initialized or if the lane is not in the cross section
* @throws ParameterException if a parameter is not defined
*/
private void updateLaneChangePossibility(final RelativeLane lane, final LateralDirectionality lat, final boolean legal,
final Map<RelativeLane, Map<LateralDirectionality, TimeStampedObject<LaneChangePossibility>>> possibilityMap)
throws GTUException, ParameterException
{
updateCrossSection();
checkLaneIsInCrossSection(lane);
if (possibilityMap.get(lane) == null)
{
possibilityMap.put(lane, new HashMap<>());
}
LaneStructureRecord record = getPerception().getLaneStructure().getFirstRecord(lane);
// check tail
Length tail = getPerception().getGtu().getRear().getDx();
while (record != null && record.getStartDistance().gt(tail) && !record.getPrev().isEmpty()
&& ((lat.isLeft() && record.possibleLeft(legal)) || (lat.isRight() && record.possibleRight(legal))))
{
if (record.getPrev().size() > 1)
{
// assume not possible at a merge
possibilityMap.get(lane).put(lat, new TimeStampedObject<>(
new LaneChangePossibility(record.getPrev().get(0), tail, true), getTimestamp()));
return;
}
else if (record.getPrev().isEmpty())
{
// dead-end, no lane upwards prevents a lane change
break;
}
record = record.getPrev().get(0);
if ((lat.isLeft() && !record.possibleLeft(legal)) || (lat.isRight() && !record.possibleRight(legal)))
{
// this lane prevents a lane change for the tail
possibilityMap.get(lane).put(lat,
new TimeStampedObject<>(new LaneChangePossibility(record, tail, true), getTimestamp()));
return;
}
}
LaneStructureRecord prevRecord = null;
record = getPerception().getLaneStructure().getFirstRecord(lane);
Length dx;
if ((lat.isLeft() && record.possibleLeft(legal)) || (lat.isRight() && record.possibleRight(legal)))
{
dx = getPerception().getGtu().getFront().getDx();
while (record != null
&& ((lat.isLeft() && record.possibleLeft(legal)) || (lat.isRight() && record.possibleRight(legal))))
{
// TODO splits
prevRecord = record;
record = record.getNext().isEmpty() ? null : record.getNext().get(0);
}
}
else
{
dx = getPerception().getGtu().getRear().getDx();
while (record != null
&& ((lat.isLeft() && !record.possibleLeft(legal)) || (lat.isRight() && !record.possibleRight(legal))))
{
// TODO splits
prevRecord = record;
record = record.getNext().isEmpty() ? null : record.getNext().get(0);
}
}
possibilityMap.get(lane).put(lat,
new TimeStampedObject<>(new LaneChangePossibility(prevRecord, dx, true), getTimestamp()));
}
/**
* @param lane RelativeLane; lane to check
* @throws GTUException if the lane is not in the cross section
*/
private void checkLaneIsInCrossSection(final RelativeLane lane) throws GTUException
{
Throw.when(!getCrossSection().contains(lane), GTUException.class,
"The requeasted lane %s is not in the most recent cross section.", lane);
}
/** {@inheritDoc} */
@Override
public final void updateCrossSection() throws GTUException, ParameterException
{
if (this.crossSection != null && this.crossSection.getTimestamp().equals(getTimestamp()))
{
// already done at this time
return;
}
this.crossSection =
new TimeStampedObject<>(getPerception().getLaneStructure().getExtendedCrossSection(), getTimestamp());
}
/** {@inheritDoc} */
@Override
public final SortedSet<InfrastructureLaneChangeInfo> getInfrastructureLaneChangeInfo(final RelativeLane lane)
{
return this.infrastructureLaneChangeInfo.get(lane).getObject();
}
/** {@inheritDoc} */
@Override
public final SpeedLimitProspect getSpeedLimitProspect(final RelativeLane lane)
{
return this.speedLimitProspect.get(lane).getObject();
}
/** {@inheritDoc} */
@Override
public final Length getLegalLaneChangePossibility(final RelativeLane fromLane, final LateralDirectionality lat)
{
return this.legalLaneChangePossibility.get(fromLane).get(lat).getObject().getDistance(lat);
}
/** {@inheritDoc} */
@Override
public final Length getPhysicalLaneChangePossibility(final RelativeLane fromLane, final LateralDirectionality lat)
{
return this.physicalLaneChangePossibility.get(fromLane).get(lat).getObject().getDistance(lat);
}
/** {@inheritDoc} */
@Override
public final SortedSet<RelativeLane> getCrossSection()
{
return this.crossSection.getObject();
}
/**
* Returns time stamped infrastructure lane change info of a lane. A set is returned as multiple points may force lane
* changes. Which point is considered most critical is a matter of driver interpretation and may change over time. This is
* shown below. Suppose vehicle A needs to take the off-ramp, and that behavior is that the minimum distance per required
* lane change determines how critical it is. First, 400m before the lane-drop, the off-ramp is critical. 300m downstream,
* the lane-drop is critical. Info is sorted by distance, closest first.
*
* <pre>
* _______
* _ _A_ _\_________
* _ _ _ _ _ _ _ _ _
* _________ _ _ ___
* \_______
* (-) Lane-drop: 1 lane change in 400m (400m per lane change)
* (--------) Off-ramp: 3 lane changes in 900m (300m per lane change, critical)
*
* (-) Lane-drop: 1 lane change in 100m (100m per lane change, critical)
* (--------) Off-ramp: 3 lane changes in 600m (200m per lane change)
* </pre>
*
* @param lane RelativeLane; relative lateral lane
* @return time stamped infrastructure lane change info of a lane
*/
public final TimeStampedObject<SortedSet<InfrastructureLaneChangeInfo>> getTimeStampedInfrastructureLaneChangeInfo(
final RelativeLane lane)
{
return this.infrastructureLaneChangeInfo.get(lane);
}
/**
* Returns the time stamped prospect for speed limits on a lane (dynamic speed limits may vary between lanes).
* @param lane RelativeLane; relative lateral lane
* @return time stamped prospect for speed limits on a lane
*/
public final TimeStampedObject<SpeedLimitProspect> getTimeStampedSpeedLimitProspect(final RelativeLane lane)
{
return this.speedLimitProspect.get(lane);
}
/**
* Returns the time stamped distance over which a lane change remains legally possible.
* @param fromLane RelativeLane; lane from which the lane change possibility is requested
* @param lat LateralDirectionality; LEFT or RIGHT, null not allowed
* @return time stamped distance over which a lane change remains possible
* @throws NullPointerException if {@code lat == null}
*/
public final TimeStampedObject<Length> getTimeStampedLegalLaneChangePossibility(final RelativeLane fromLane,
final LateralDirectionality lat)
{
TimeStampedObject<LaneChangePossibility> tsLcp = this.legalLaneChangePossibility.get(fromLane).get(lat);
LaneChangePossibility lcp = tsLcp.getObject();
return new TimeStampedObject<>(lcp.getDistance(lat), tsLcp.getTimestamp());
}
/**
* Returns the time stamped distance over which a lane change remains physically possible.
* @param fromLane RelativeLane; lane from which the lane change possibility is requested
* @param lat LateralDirectionality; LEFT or RIGHT, null not allowed
* @return time stamped distance over which a lane change remains possible
* @throws NullPointerException if {@code lat == null}
*/
public final TimeStampedObject<Length> getTimeStampedPhysicalLaneChangePossibility(final RelativeLane fromLane,
final LateralDirectionality lat)
{
TimeStampedObject<LaneChangePossibility> tsLcp = this.physicalLaneChangePossibility.get(fromLane).get(lat);
LaneChangePossibility lcp = tsLcp.getObject();
return new TimeStampedObject<>(lcp.getDistance(lat), tsLcp.getTimestamp());
}
/**
* Returns a time stamped set of relative lanes representing the cross section. Lanes are sorted left to right.
* @return time stamped set of relative lanes representing the cross section
*/
public final TimeStampedObject<SortedSet<RelativeLane>> getTimeStampedCrossSection()
{
return this.crossSection;
}
/** {@inheritDoc} */
@Override
public final String toString()
{
return "DirectInfrastructurePerception";
}
/**
* Helper class to return the distance over which a lane change is or is not possible. The distance is based on a
* LaneStructureRecord, and does not need an update as such.
* <p>
* Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
* <br>
* BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
* <p>
* @version $Revision$, $LastChangedDate$, by $Author$, initial version 14 feb. 2018 <br>
* @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
* @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
* @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
*/
private class LaneChangePossibility
{
/** Structure the end of which determines the available distance. */
private final LaneStructureRecord record;
/** Relative distance towards nose or tail. */
private final double dx;
/** Whether to apply legal accessibility. */
private final boolean legal;
/**
* @param record LaneStructureRecord; structure the end of which determines the available distance
* @param dx Length; relative distance towards nose or tail
* @param legal boolean; whether to apply legal accessibility
*/
LaneChangePossibility(final LaneStructureRecord record, final Length dx, final boolean legal)
{
this.record = record;
this.dx = dx.si;
this.legal = legal;
}
/**
* Returns the distance over which a lane change is (>0) or is not (<0) possible.
* @param lat LateralDirectionality; lateral direction
* @return Length distance over which a lane change is (>0) or is not (<0) possible
*/
final Length getDistance(final LateralDirectionality lat)
{
double d = this.record.getStartDistance().si + this.record.getLane().getLength().si - this.dx;
if ((lat.isLeft() && this.record.possibleLeft(this.legal))
|| (lat.isRight() && this.record.possibleRight(this.legal)))
{
return Length.createSI(d); // possible over d
}
return Length.createSI(-d); // not possible over d
}
}
}