Support tile packs

This was discussed in the very early days as a potential feature and now seems very relevant. We need a Target Release for this.

Chris.

Given a Target Release of 1.4. This can be changed as required.

Chris.

Is this a duplicate of Issue #20?

willu wrote:
> Is this a duplicate of Issue #20?

I think it is.
But patchs posted on issue #20 are for a slightly different problem: preloading tiles on the current route.
So we should merge them and create a new issue to "preload tiles for calculated route", or just rename issue 20 into this.

When I put these 2 issues in I wasn't aware of OSM's tile usage policy:
http://wiki.openstreetmap.org/wiki/Tile_usage_policy

I would consider #20 and this issue to go against the policy unless we had our own tile server. I think preloading the upcoming route is within the policy so we should just do that instead.

What I had in mind needn't involve bulk-downloading tiles from the main OpenStreetMap tile servers, and certainly isn't about pre-loading tiles for a particular route.

I want to be able to download a map pack for, say, London or the Snowdonia National Park. This could either be in the form of tile pack downloads, which I could be very large files, or data that OSN can render as vectors if you wanted to take it in that direction. The latter would mirror the files that Garmin GPS units can use.

There's no reason why OSN should have to provide those map packs, third parties would doubtless step into the fray if such a feature was available.

I suppose Tom's approach is good, although I suppose that difficult to implement, because it implies to render vectors instead of tiles. This is the approach of Navit (another known navigation app) and has the advantage of applying styles for the maps, 3D, etc.

As far as I can see, this is already implemented in AndNav2:
http://wiki.andnav.org/index.php/List_Of_MapTilePacks

It seems to make a lot more sense, however, to do this properly through osmdroid:
http://code.google.com/p/osmdroid/issues/detail?id=8

Creating and updating maptilepacks will be time-consuming and needs to be as current as possible. Therefore, if someone is going to all that effort to do an updated tilemap of Auckland for AndNav2, it would be great to use it in OSN, and vice versa. Any code to, for example, get citywide tilepack and then only download changes when on the road, would also be best shared between all osmdroid projects.

There seems to be a lot of potential for innovation here (delta updates etc), all of which would be best shared between all similar projects.

Have you used maptilepacks provided by andnav2 (http://wiki.andnav.org/index.php/List_Of_MapTilePacks) on OpenSatNav or other osmdroid based application?
Because zipped maptilepacks provided by andnav2 have tiles saved as .png.andnav and I think this naming convention doesn't work well with osmdroid, so is probably necessary to create a bash script to rename all tiles inside a maptilepacks.