bound2osmtile

This package converts passed WGS84 bounds to the closest OSM slippy tile request values. This is done by following the suggestions in the OSM Wiki.

Installation

Use standard npm installation

npm install --save bound2osmtile

Usage

Pass the WGS84 bounds to the function:

var bound2tile = require('bound2osmtile');
 
// [north, east, south, west]
bound2tile([48.1354432, 11.6037082, 48.123412, 11.621389]);
 
// [[north, east], [south, west]]
bound2tile([[48.1354432, 11.6037082], [48.123412, 11.621389]]);
 
// [L.LatLng, L.LatLng]
bound2tile([L.latLng(48.1354432, 11.6037082), L.latLng(48.123412, 11.621389)]);
 
// L.LatLngBounds
bound2tile(L.latLngBounds([48.1354432, 11.6037082], [48.123412, 11.621389]));
 
// GeoBounds
bound2tile(new (require('geobound-object'))([48.1354432, 11.6037082], [48.123412, 11.621389]));
 
// output:
// { 
//     valid: true, 
//     x: 8720, 
//     y: 5686, 
//     z: 14 
// }

Options

You can pass additional options to control the behavior.

zoom (default: 19)

Zoom level the algorithm should start with. If no zoom is passed, the algorithm starts with the most detailed OSM zoom level (19). This can be used to define a minimal zoom level that should be used.

bound2osmtile([48.1354432, 11.6037082, 48.123412, 11.621389], {
    zoom : 12
});
 
// output (note different zoom and x/y values compared to the above output):
// { 
//     valid: true, 
//     x: 2180, 
//     y: 1421, 
//     z: 12
// }

toUrl (default: false)

Convert the output tile to a OSM sloppy tile URL. If urlBase or fileExtension is not specified, the output returns an URL to openstreetmap.org.

bound2osmtile([48.1354432, 11.6037082, 48.123412, 11.621389], {
    zoom : 12,
    toUrl : true
});
 
// output
// "http://tile.openstreetmap.org/12/2180/1421.png"

urlBase (default: "http://tile.openstreetmap.org/")

Base url that should be used for url conversion. Please note that this parameter requires "toUrl" to be set true.

fileExtension (default: ".png")

File extension that should be used for the url output. Please note that this parameter requires "toUrl" to be set true.

bound2osmtile([48.1354432, 11.6037082, 48.123412, 11.621389], {
    zoom : 12,
    toUrl : true,
    urlBase : 'http://my.own.com',
    fileExtension : '.json'
});
 
// output
// "http://my.own.com/12/2180/1421.json"

Contribute

Feel free to add issues or pull requests. I'm glad for every kind of feedback!