CODEWITHSUNDEEP
iosopenstreetmapoffline-caching
user3124010
user3124010

Reputation:

Download all tiles for a country from Open Street Map

I am creating an offline map app for iPhone (Using MKMapKit). It will have a list of countries. If the user selects a country, all tiles will be downloaded and stored on the iPhone. I will use Open Street Map as the maps provider.

(I have read that bulk downloading is forbidden, but given that tiles for a country is pretty small (≈200MB) and that they will only be downloaded once, at least I don't think it's a problem.)

I think I will be using the template URL @"http://c.tile.openstreetmap.org/{z}/{x}/{y}.png" to downloaded the tiles and then store them. My problem is that I don't know how to determine which tiles belong to which country and therefore to determine which to download.

I found this link in another SO answer, but that only allows you to download .pbf files (which I have no idea what it is) and per continent.

Upvotes: 1

Views: 3804

Answers (2)

scai
scai

Reputation: 21499

This is a problem. Downloading 200 MB of tiles only once is already questionably because it is not just about the traffic, these tiles have to be rendered first. But if I understood you correctly, with your application every user will download these 200 MB.

Instead you should think about downloading raw data (which PBF is) and either render your own raster tiles as already suggested by MaM, or create a vector map as done by other popular apps, like OsmAnd and Navit.

Upvotes: 1

MaM
MaM

Reputation: 2069

First: If you really want to grab all tiles (at all zoom-levels) you should read the OSM Tile Usage Policy again with care. If you just want to download all the tiles once (for your dev environment) you can use existing downloaders that allow you to select the desired country and download them. This will result in a directory with 1000s of small images and might take some days.

The better way would be to setup your own (desktop or server based) tile rendering chain that gives you full control about styling and doesn't stress the community ressources. Please consult www.switch2osm.org for a detailed tutorial on how to setup a server based rendering stack.

Upvotes: 5

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