Multiple waypoint and route segment clearing bugs
  • When traveling, I typically set up a route with multiple waypoints.  The expected behavior when following the route is that waypoints will clear as they are encountered, and the purple route segments will disappear off the screen once they are passed.  While much of the time the routing display works as expected, I have seen a number of anomalous behaviors.

    1. Waypoint is not cleared when passed.  See the Waypoint and route segment not clearing.mp4.  Note that while the position icon is well past the waypoint flag, but the flag still shows in orange not gray.  This I have seen only very occasionally.
    2. Route segment not cleared when passed.  See the Waypoint and route segment not clearing.mp4.  Note that while the route segment around the waypoint flag has been passed, that segment has not cleared.  I have seen this on multiple occasions.
    3. Route segment clears ahead of passing it.  See the Route segment clearing ahead of position icon.mp4.  Note that the clearing starts off as expected, but then at about 20 seconds into the video the segments are cleared ahead of reaching them.  This continues for a while.  Then at about 1:30, it appears that the clearing will start to be correct, but then at 1:50 the clearing jumps to ahead of the position icon again.  There is also an nmea file recorded at the same time.
    4. The next waypoint past the one reached is cleared instead of the one reached.  See the Waypoint cleared ahead of reaching.mp4.  Note that at the start of the video, the next waypoint is already in gray even though it has not been reached.  Note that the Time to Waypoint at the bottom right of the screen is <1 min.  At about 1:22 into the video, the distance to the next waypoint is shown as 115 feet.  At that time, the next waypoint is cleared as can be seen at the left of the screen.  At 1:28, the distance to the waypoint is shown as 10 feet, so that is clearly indicating the first gray waypoint, not the one that just cleared.  Then at 1:29, the distance to the next waypoint jumps to 213 feet, indicating the distance to the waypoint that was incorrectly cleared.  It appears that the software can get into a mode where instead of the waypoint that has been reached is cleared, the next one after that in the Route Info is cleared.  Once that occurs, the next waypoint is cleared instead of the waypoint reached during the rest of the routing.  I have seen this on multiple occasions.
    5. When a waypoint and the end of a route segment are coincident, or at least very close, there is an occasional odd behavior.  The route segment will clear, the map display rotates 180 degrees, and the position icon shifts to the start of the route segment that was just cleared.  The after a short while, the map rotates 180 degrees back to the normal orientation, the position icon goes to the correct location, and proper navigation continues.  I have not been able to capture a video of this behavior.  It may be a race condition in the software since if I backtrack and go through the same route, the odd behavior does not necessarily repeat.
    The files are located here if it is easier to download the files for viewing.
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  • I have been able to get a screen video of the map rotating 180 degrees.  See the Map rotates 180 degrees.mp4.  The video starts off with the distance reading synced with the actual location.  The first two turns occur when the distance reached close to 0.  At 0:27 into the video, the distance jumps to 531 feet.  At 0:45, the position marker reaches the waypoint flag, but the distance reads 217 feet.  The waypoint does not clear.  At 2:04, the distance is down to 26 feet to the waypoint, but there is no waypoint flag near that location.  At 2:07, the map rotates 180 degrees, and the position icon jumps to before the waypoint flag (which is now cleared) and to the end of the uncleared route segments.  The distance to waypoint now shows 3 feet.  Then at 2:17, the position icon jumps back to the actual location.  It should be noted that the distance to the waypoint now shown is again greater than the actual distance.  When the position icon reached that next waypoint (after the end of this trimmed video), the distance to waypoint read 400 feet.

    Another example of the distance to waypoint and waypoint position is shown in the Waypoint clearing and distance to waypoint out of sync.mp4.  Note that at 0:26 into the video, the waypoint flag is reached, but the distance to waypoint is shown as 797 feet.  The flag is not cleared.  When the distance to waypoint drops to about 105 feet at 1:31, the flag is cleared even though it is well behind the actual position.  There is no flag at the location of the position icon at that time.  Note also that the route segments have not been clearing.  At 1:44, the route segments are cleared.

    I also observed a new anomaly today.  See the Remainder of route clears all at once.mp4.  At 0:21 into the video, the waypoint flag clears as expected when the distance to waypoint reaches less than 120 feet.  Then the position markers starts sliding around [note the jump in position between 0:21 and 0:22 - I was on a bicycle, and I don't pedal that fast :^)  ].  The distance to waypoint is shown as 122 feet.  Then at 0:26, the distance changes to 108 feet, and it indicates that this is the distance to the destination.  That is clearly incorrect; no additional waypoint was passed, and no waypoint or destination flags are shown in the screen where the remaining route is clearly more than 108 feet long.  Since the distance to destination is less than 120 feet, the destination flag is also cleared.  At 0:34, one can see that all flags have been cleared, but the position marker is nowhere near the destination.

    These were all recorded on a Pixel 3a running Android 11.  I have seen most of these behaviors in the past on my older Samsung Galaxy S4.

    These new videos are located at the same download link as in my original post.
  • Hi Tomas,

    Is there anything else I can provide to help with this issue?


  • we cannot replicate this and we had no reports of such behaviour from other users

    please record NMEA and email it together with your departure, destination and waypoints in coordinates
  • Ok, will do.  It may take some time as it (naturally) doesn't always happen.
  • I have recently observed the route segment clearing going from correct to two segments ahead.  The transition occurred when going around a hairpin turn.

    Consider the condition for a hairpin turn which results in five route points in a horseshoe shape.  Label them 1 through 5.

                    3      4     5    -->
              1      <--

    Due to the location accuracy of a GPS signal, and the tolerance allowed by the navigation program in accepting that a point as being reached, point 3 may be 'reached' before points 1 or 2.  How does the route display thread of the app handle that?  From my observations, the app clears the segments up to point 3.  Then when point 1 is reached, the segment between points 3 and 4 is cleared.  When point 2 is reached, the segment between points 4 and 5 is cleared.  This "two segments ahead" clearing continues until a rerouting is performed due to some reason such as going far enough off of the displayed route.  Sometimes, the segment clearing is one segment ahead instead of two.

    I have also frequently observed that the route clearing is two segments behind.  This occurs at the start of a trip.

    Departure  -->    1       2      3     4

    The segment clearing does not start until point 3 is reached.  Then the segment between the departure and point 1 is cleared.  When point 4 is reached, the segment between points 1 and 2 is cleared.  As with the clearing 'ahead', this continues until a re-route is performed for some reason.  The observed behavior indicates that the route display thread often misses or ignores the first two points reached on a trip.  Since this particular behavior often occurs, I will try to record a NMEA file.

  • I notice that when the comment was posted, the horseshoe shape for the five points of the hairpin turn became reformatted so that the position of the points is distorted.  If it makes the explanation unclear, please let me know how I can repost it without distortion.

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