[FEATURE] Allow uploading of OSM offline maps

[+sbeelis]

I occasionally go caching abroad where I don't have GSM data connection. I know I can already use offline maps, but think this could be improved.

 

Currently I need to do the following:

1. create a PQ with the caches I'm interested in

2. download the PQ onto my iPhone

3. store the PQ for offline use, select "include maps"

 

Now the last steps works in principle, however, it is very slow as it seems that every tile is downloaded seperately. I've tried it with a 1000 cache PQ before my trip to Berlin and aborted after about 4 hours when it still hadn't progressed past cache 500. I then broke my PQ up into 10 pocket queries of 100 caches each and that worked, but it was a lot of hassle to do so and for larger trips might just not be practical.

 

Also, I'm not sure how this mechanism works and whether it detects if a tile has already been loaded for another cache in the same PQ (I won't even speculate about caches in other PQs in the same area).

 

On the other hand, I can just upload a pre-generated OSM file onto my Garmin device and have the offline maps available easily.

 

Would it be possible to add support for gmapsupp.img type OSM maps to the iPhone app? Ideally I could then transfer such maps when synching my iPhone using iTunes over my USB cable or WLAN and would just need to download the PQs for the cache data, not the maps. This would make this step much less painful.

 

Many sites already offer such maps and the format used should be well documented. This would be a great addition to offline caching with the iPhone app.

[+sbeelis]

And to expand a bit on my idea:

 

I'm not sure if the commercial TopoMaps for Garmin GPSr use the same gmapsupp.img format or another. If they use the same format, this change would even allow us to use our TopoMaps on the iPhone, which would be a great thing (assuming this is possible (a) with regards to unlocking the maps for the iPhone and ( the licensing terms of the Topo maps).