Map Switching too fussy over zoom levels

Alan Budden shared this problem 3 years ago
In Progress

Locus Maps has a brilliant feature that it will automatically scale map tiles when tiles don't exist at a particular zoom level (for example creating z11 tiles by stitching four z12 tiles together). However, the map area detection doesn't seem to take this into account.

Let's say I have two off-line maps, called "map-odd.gemf" and "map-12.gemf". map-odd has tiles for the whole of the UK at zoom levels, 7,9,11,13,15. map-12 has tiles for the whole of the UK at zoom level 12.

If I am using map-odd, I would expect to open the "Quick Map Switcher" and see map-12 in the list, but it doesn't appear. If I go to the full map list, I can select map-12 but it says "Selected map out of current view. Center?" and I have to press "No" to avoid it moving the map to a different place. On a positive note, if I click "No", it works fine.

This is a minor irritation in an otherwise very nicely implemented feature, so many thanks yet again for a great app.

Comments (3)


Good day Alan,

if I understand correctly, it looks like both your maps has same coverage, but app incorrectly detect coverage of your map-12 right? Is it possible to share these maps with me for test? Thank you


Hello Merion,

The one I've got is huge (>10 GB), but I'll try to make a smaller one that I can share more easily.


On 7 Sep 2017 12:30, "Locus Map" <> wrote:


Hello Menion,

There's a small one (about 12 MB) shared here:

It has some map data in the Cotswolds and Brecons areas of the UK (but only at a few zoom levels). If you navigate to Cirencester in the UK and switch to this map, it'll pop up the message about "Selected map out of current view. Center?".

Having looked at it again, I don't think it's anything to do with zoom level. What I did:

  1. Open this map (in Locus 3.37.2)
  2. Press "No" to the "Center?" question
  3. Move/zoom the map until Cirencester was visible
  4. Switch to the Great Britain vector map (without changing zoom or position)
  5. Switch back to the GEMF map linked above - it prompted me to say the "Selected map out of current view"
  6. Press "No" to the question - it took me back to the exact same view at step 3 above.

Hope that helps demonstrate the problem.