55 lines
1.2 KiB
Markdown
55 lines
1.2 KiB
Markdown
s2-geometry (JavaScript/ES5.1)
|
|
======================
|
|
|
|
A pure JavaScript/ES5.1 port of Google/Niantic's S2 Geometry library (used by **Ingress**, **Pokemon GO**)
|
|
|
|
Currently contains basic support for S2Cell
|
|
|
|
Simple Examples
|
|
---------------
|
|
|
|
```javascript
|
|
var level = 15;
|
|
var latlng = { lat: 40.2574448, lng: -111.7089464 };
|
|
var cell = S2.S2Cell.FromLatLng(latlng, level);
|
|
|
|
cell.getNeighbors(); // [ cellLeft, cellDown, cellRight, cellUp ]
|
|
|
|
cell.getLatLng(); // { lat: 40.2574448, lng: -111.7089464 }
|
|
```
|
|
|
|
convert Cell Id to Quadkey
|
|
------------------
|
|
|
|
Convert from base 10 (decimal) `S2 Cell Id` to base 4 `quadkey` (aka hilbert curve quadtree id)
|
|
|
|
Example '4/032212303102210' becomes '9749618446378729472'
|
|
|
|
```
|
|
'use strict';
|
|
|
|
var quadkey = '4/032212303102210'
|
|
var parts = quadkey.split('/');
|
|
var face = parts[0]; // 4
|
|
var position = parts[1]; // '032212303102210';
|
|
var level = '032212303102210'.length; // 15
|
|
|
|
var cellId = S2.fromFacePosLevel(face, position, level);
|
|
|
|
console.log(cellId);
|
|
```
|
|
|
|
Convert from hilbert quadtree id to s2 cell id:
|
|
|
|
Example '9749618446378729472' becomes '4/032212303102210'
|
|
|
|
```
|
|
'use strict';
|
|
|
|
var cellId = '9749618446378729472';
|
|
|
|
var hilbertQuadkey = S2.toHilbertQuadkey(cellId);
|
|
|
|
console.log(hilbertQuadkey);
|
|
```
|