Cul-De-Sac Not Part of Route Lane

[mchlswyr]

• This has only been tested on scenarios/maps/experimental_maps/lanelet2_bathurst.osm

Problem

• If a vehicle's route contains a cul-de-sac, then there is an issue when calling lanelet_route.fullLane(lanelet)
• The issue is that the cul-de-sac is considered as a separate lane from the lane that enters it
• This causes two problems:
  1. If lanelet is in the cul-de-sac, then the full lane will just be a part of the cul-de-sac
  2. If lanelet is outside of the cul-de-sac, then the full lane will end just before the cul-de-sac

Problem Before PR #70

• lanelet_route.fullLane(lanelet) is used here
• In this case, padding is being used to extend the lane
• If lanelet is in the cul-de-sac, then the full lane plus the padding will be a loop around the cul-de-sac
• If lanelet is outside of the cul-de-sac, then the full lane plus the padding will not enter and exit the cul-de-sac
• It will just go part of the way around the cul-de-sac and end there

Problem After PR #70

• lanelet_route.fullLane(lanelet) is used here
• In this case, the lane is extended until there are no more lanelets left to extend the lane (until the end of the map is reached)
• If lanelet is in the cul-de-sac, then the full lane plus the extension will be a loop around the cul-de-sac
• If lanelet is outside of the cul-de-sac, then the extension will be an infinite loop around the cul-de-sac
• This is because the lane is extended until there are no more lanelets left to extend with
• And, in the cul-de-sac, there is always a next (or previous) lanelet -- which is a lanelet that is also in the cul-de-sac -- and so the lane never stops being extended

[mchlswyr]

This issue is resolved in PR #70 with the addition of route_full_lane() in mapping/LaneletMap.py, which is a wrapper for lanelet_route.fullLane().

When the route passes through a cul-de-sac, then the shortest path will also pass through the cul-de-sac. However, lanlet_route.fullLane() does not pass through the cul-de-sac. So, if the lane that is returned from lanelet_route.fullLane() should pass through the cul-de-sac, then we should instead get the lane from lanelet_route.shortestPath(). This is what route_full_lane() does.