https://github.com/mapbox/leaflet-pip

point in polygon intersections for leaflet
https://github.com/mapbox/leaflet-pip

Last synced: 9 days ago
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point in polygon intersections for leaflet

• Host: GitHub
• URL: https://github.com/mapbox/leaflet-pip
• Owner: mapbox
• License: bsd-2-clause
• Created: 2013-03-28T01:53:11.000Z (over 11 years ago)
• Default Branch: gh-pages
• Last Pushed: 2022-05-22T23:08:08.000Z (over 2 years ago)
• Last Synced: 2024-10-22T02:32:22.965Z (14 days ago)
• Language: JavaScript
• Homepage: https://mapbox.github.io/leaflet-pip/
• Size: 160 KB
• Stars: 199
• Watchers: 119
• Forks: 46
• Open Issues: 8
• Metadata Files:
  • Readme: README.md
  • Changelog: History.md
  • License: LICENSE

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README

        
## point in polygon for Leaflet

[![build status](https://secure.travis-ci.org/mapbox/leaflet-pip.png)](http://travis-ci.org/mapbox/leaflet-pip)

A [Leaflet](http://leafletjs.com/)-friendly API for [point in polygon](http://en.wikipedia.org/wiki/Point_in_polygon)

operations, using [substack](https://github.com/substack)'s

[point in polygon](https://github.com/substack/point-in-polygon) library.

## install

With browserify

    npm install @mapbox/leaflet-pip

Resolve for a CDN/packaged version:

    https://unpkg.com/@mapbox/leaflet-pip@latest/leaflet-pip.js

## example

```

var gjLayer = L.geoJson(statesData);

var results = leafletPip.pointInLayer([-88, 38], gjLayer);

// results is an array of L.Polygon objects containing that point

```

## api

### `leafletPip.pointInLayer(point, layer L.GeoJSON, [first])`

Point can be:

* A two-element array of `[lng, lat]`

* A `L.LatLng` object

Layer must be:

* A `L.geoJSON` layer

`first` can be:

* `boolean`: `true` to accept the first match, or `false` to return all

  polygons containing this point. This can be useful if you know that your

  polygons are non-overlapping or don't care about more than one result,

  since it will be much faster. By default, **this is false** and all matches

  are returned.

Returns:

An array of polygons in which the given point resides, an empty array if there

are none. The polygons are returned as direct sublayers, so they can include

MultiPolygons. You can call `pointInLayer` again on those if you want the

sub-polygon result.

### `leafletPip.bassackwards`

Leaflet treats literate coordinate arrays as `[lat, lon]`, unlike GeoJSON

and [any true scotsman](http://en.wikipedia.org/wiki/No_true_Scotsman). `leaflet-pip`

treats literate coordinate arrays as `[lon, lat]`, but if you set `bassackwards`

to true, it'll do things the Leaflet/Google Maps API way.