David
David

Reputation: 3105

Android OpenStreetMap tracker available offline

I'm new at osmdroid and I'm trying to build simple GPS tracking application that must work offline. So first of all I know that osmdroid works with .osm But how to download osm file directly to my android device and more importantly how later I need to use it. I dont understand .osm file is simply just xml with lots of coordinates and other data. So how that .osm file can be transform to a graphical map? I know that is necessary to parse .osm file to get data, but where to download actual graphical map?

Upvotes: 0

Views: 883

Answers (1)

spy
spy

Reputation: 3258

osmdroid does not currently present .osm data, mainly due to performance reasons. osmdroid does render raster images that someone can capture into a zip or database and then transfer to device. The problem really is space. It's a big planet and getting raster images can be huge! You'd have to prepare geographic regions into a database then host them somewhere and have your app download them on demand.

osmdroid as a wiki on offline maps here:

https://github.com/osmdroid/osmdroid/wiki/Offline-Map-Tiles

An alternative approach is something like Mapsforge, which can preconvert .osm data into their own binary format, also chunked up by geographic region. Same rules apply, however the file/download sizes are much smaller. Support for osmdroid using Mapsforge is in beta at the moment, however mapsforge can run on it's own and has it's own demo apps and whatnot.

To transform the .osm file into a graphical map, you need something like renderd and a slew of other tools, all on open street maps wiki. Again, you need a boat ton of storage for the planet to convert it into raster images. Then you'd still have to package them somehow and get them on device.

Or you can just use online maps.

Upvotes: 2

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