AlpineQuest & OfflineMaps

When I have several file-based maps stored in the same folder...

Could you please give us a small summary of the logic being used for auto-switching to an in-bound map when moving or zooming out of the range of the currently displayed map?

- How is the new map chosen in the list of in-bound maps of the folder?

- Is there a way to have some control on the priorities of this selection (by file-naming rules, etc)?

- Can auto-switch be turned off (without having to move each map to its own folder)?

Hi Pascal,
Here is how it's supposed to work (but there may be some issues as you reported here, I'll make my tests again).

- When using the "+/-" zoom buttons, if only one file based map is selected, and if you go further than the max zoom level of this map (case 1), or lower than the min zoom level (case 2), the application checks if there is a map in the same folder that covers the same area, and has a higher level of details (for case 1) or lower level of details (for case 2). If so, this map is selected. If multiple maps are found, the one that has the closest zoom level than the current one is chosen.

- When moving the map around, if only one file based map is selected, and if this map does not cover the center location anymore, the application checks if there is another map in the same folder that covers this location. If multiple maps are found, the one that has the closest zoom level than the current one is chosen.

- Do disable those features, you can display at least 2 maps, or disable them using those user settings: Note that those features require maps to have a correctly set coverage outline for all levels of details, which is unfortunately not always the case (sometimes white margins are taken into account, bounds are not precise, etc.).

"The map having the closest zoom is chosen"

Could you please detail that? There can be several maps available for that zoom level. For example, I left my previous local map by moving out of its location and I am now at ZL 10. I have two other in-range maps, a road map covering ZL 6-11 and a hiking map covering ZL 8-13. Which one is chosen?

Concerning the bug... I guess that there is some preprocessing taking place for file-based maps, which some time doesn't work because of the bug, or is just not ready yet because the map is large and takes time to compute. In any case, could you please ignore those maps from the autoswitch process?

Thanks for this wonderful piece of software!

Which one is chosen?

In your particular case, based on the current code, the application should choose the "6-11" map. Maps are first ordered by last ZL (ascending), so "6-11" matches first, and no other matching map is found than has a ZL with less difference.
But this is just how the current code is made, I would tend to say that with you have multiple maps that exactly match, the application should pick up one randomly.

For the bug, some map format require time to load the outline (initially, then the app caches them), but when it's not available the application does not choose them already.

Note that if you zoom out until the base world map, the outlines of all maps in the folder of your map should be displayed. This way you can have a look if some outlines are incorrect (if your maps cover a large area).

Actually, when I zoom out to the base map, those "unprocessed" maps do not show up. Also their graphical preview in the map list remains white. Note that I might see one of these maps showing up correctly one time I use the software, and not correctly the next time I use the software.

The map autoswitch selection: It would be nice that you define formally the priority rules between all inbound map, and remove anything that could be "random". For instance, if zoom range priority rules cannot sort several maps, add a rule such as "the shown map is the first in alphabetical order". This would let the user have some control by naming the maps adequately.

Another question about autoswitch: What happens if I create a single map "French Islands" containing both La Réunion and Martinique-Guadeloupe? Is map range calculation smart enough to handle appropriately the large voids between the mapped areas, or will that mess up autoswitch because only a global bounding box is considered?

Again, thanks for your tremendous work!

OK, I think I found a case when the file-based map precomputation bug happens.

It actually happens when switching from one map folder to another using the file-based map browser. No map info is precomputed in the new folder. Quitting and re-launching the app triggers the recomputation.

Hope this helps...

Hi Pascal,
After a long time, this problem should be fixed in version 2.2.7.