#375 Loss of position when zooming out

closed
nobody
Routing (39)
5
2013-03-16
2010-12-29
Martin
No

During routing with a route larger then 300 km, I tried to zoom out to see the whole route. After zooming out some steps the route text color turned from green to red to indicate that I off the route. After zooming in again everything was ok. This also leads to route recalculation if activated.

Discussion

  • Martin

    Martin - 2010-12-30

    I think the reason is the display setting. When zooming out to some zoom level smaller roads disappear. This is normally fine. If your actual position is on such a road the position on the road is lost.
    I would like to see the route line independent although it goes through a smaller road which isn't displayed at a certain zoom level. Then the position is hopefully not lost.

     
  • Jyrki Kuoppala

    Jyrki Kuoppala - 2011-01-15

    sk750, does your commit b1c12d2a5bcfd8f037d1be674aa60edddf6e876e from 2 Jan fix this?

     
  • sk750

    sk750 - 2011-01-16

    @jkpj: Can we please use complete URLs to the Git repo, this will make it easier to find the commit with the web browser on the mobile: http://gpsmid.git.sourceforge.net/git/gitweb.cgi?p=gpsmid/GpsMid;a=commit;h=b1c12d2a5bcfd8f037d1be674aa60edddf6e876e

    To your question: This commit doesn't solve all reasons for the issue - there are still at least two problems to be solved for it:
    1) When zooming out streets will disappear (to save memory from the higher tile levels) - if your route location is on a disappeared way on the route line, you will be off-route.
    2) I think we are calculating the offset to the route line by converting pixels to the route line (that's faster due to integer arithmetics). If you zoom out too far one pixel besides the route line might already trigger a route recalculation because of the rounding issue from 1 pixel to meters.

     
  • Martin

    Martin - 2011-04-28

    Calculate off distance to route using the gps position

     
  • Martin

    Martin - 2011-04-28

    I attached a patch which solves issue 2.
    With a valid gps position and centered screen the distance between the actual gps coordinates and the nearest way position is calculated. When zooming out the off distance stays correct, no route recalculation is triggered.

     
  • Jyrki Kuoppala

    Jyrki Kuoppala - 2011-04-29

    The patch is committed, thanks.

     
  • sk750

    sk750 - 2011-04-29

    I just had a quick glance at the patch, probably much less than jkpj, but I think it contains other things e.g. forsourceforge.net/tracker/?func=detail&atid=939977&aid=2872332&group_id=192084 , doesn't it?

     
  • Martin

    Martin - 2011-06-09

    The patch added an increased penalty for one ways. This improves the detection of the way the user is traveling on in case of one ways. For example motor ways but also round abouts.

    It would be nice if someone knowing more about the drawing code could have a look at issue 1.

     
  • Jyrki Kuoppala

    Jyrki Kuoppala - 2011-06-10

    It would be nice to have a simple function to have a "route overview", which would show the route on the map. Currently viewing all of the route with zooming out fails also for intermediate ways of the route which will disappear when zoomed out.

     
  • Martin

    Martin - 2011-07-28

    I attached a patch which solves issue 1.
    The patch will require the application of some patches I posted recently or needs to be adopted.
    With the patch all visible tiles in all layers will be tested for painting the route line. Only tiles containing the route line will be further processed.
    The patch also hides the text of custom way points when zoom out.
    The patch also does some speed optimizations.

     
  • Martin

    Martin - 2011-07-28

    Always visible route line

     
  • Martin

    Martin - 2013-03-16
    • status: open --> closed
     
  • Martin

    Martin - 2013-03-16

    Problem 2 has already been solved long time ago.
    Problem 1 is solved in git branch master_extended. There all tiles of a route line are memorized and the route line is completely displayed when zooming out. So no recalculation is triggered.

    Closing.

     

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