Boost-geospatial-index NPM

boost-geospatial-index

Stores and indexes geospatial shapes and exposes query methods.
Shapes can overlap.

This library is used by Kuzzle's real-time engine and is focused on query performances:

shapes are indexed using a R* tree ("slow" insertion, very fast query time)
based on the C++ boost::geometry library
pure C++ module
no dependencies

Table of content

Install

npm install --save boost-geospatial-index

API

Creating a new index

var BoostSpatialIndex = require('boost-geospatial-index');

var bsi = new BoostSpatialIndex();

Adding shapes to the index

addBoundingBox(id, min_lat, min_lon, max_lat, max_lon)

Returns: boolean

Argument	Type	Description
`id`	string	shape unique identifier
`min_lat`	number	bottom side of the bounding box
`min_lon`	number	left side of the bounding box
`max_lat`	number	top side of the bounding box
`max_lon`	number	right side of the bounding box

addCircle(id, lat, lon, radius)

Returns: boolean

Argument	Type	Description
`id`	string	shape unique identifier
`lat`	number	y coordinate of the circle's center
`lon`	number	x coordinate of the circle's center
`radius`	number	radius of the circle, in meters

addAnnulus(id, lat, lon, outer, inner)

Returns: boolean

Argument	Type	Description
`id`	string	shape unique identifier
`lat`	number	y coordinate of the annulus' center
`lon`	number	x coordinate of the annulus' center
`outer`	number	outer radius of the annulus, in meters
`inner`	number	inner radius of the annulus, in meters

addPolygon(id, points)

Creates an open polygon (automatically closed by the library).

Returns: boolean

Argument	Type	Description
`id`	string	shape unique identifier
`points`	array	array of arrays of lat, lon points

Querying the index

queryPoint(lat, lon)

Gets all shapes containing the provided point coordinates. Shapes matching the provided point exactly on their borders or corners are also returned.

If no shape match, an empty array is returned.

Returns: array of shape ids

Argument	Type	Description
`lat`	number	y coordinate
`lon`	number	x coordinate

queryIntersect(points)

Gets all shapes intersecting the polygon created from the list of point coordinates provided. Shapes partially covered by the polygon also returned.

If no shape match, an empty array is returned.

Returns: array of shape ids

Argument	Type	Description
`points`	array	array of arrays of lat, lon points

Removing a shape from the index

remove(id)

Returns: boolean

Argument	Type	Description
`id`	string	shape unique identifier

Example

var BoostSpatialIndex = require('boost-geospatial-index');

var bsi = new BoostSpatialIndex();

bsi.addBoundingBox('Montpellier, France', 43.5810609, 3.8433703, 43.6331979, 3.9282093);
bsi.addPolygon('Montpellier Millenaire', [
  [43.6021299, 3.8989713],
  [43.6057389, 3.8968173],
  [43.6092889, 3.8970423],
  [43.6100359, 3.9040853],
  [43.6069619, 3.9170343],
  [43.6076479, 3.9230133],
  [43.6038779, 3.9239153],
  [43.6019189, 3.9152403],
  [43.6036049, 3.9092313]
]);
bsi.addAnnulus('Around Kuzzle HQ', 43.6073913, 3.9109057, 1500, 1);
bsi.addCircle('Montpellier Airport', 43.5764455, 3.948711, 2000);

console.log('Querying Kuzzle HQ: ', bsi.queryPoint(43.6073913, 3.9109057));
console.log('Kuzzle team favorite pub:', bsi.queryPoint(43.6002203, 3.897105));
console.log('Hangout spots:', bsi.queryIntersect([
            [43.6072203, 3.9],
            [43.607,5.900],
            [44.609000, 5.90000],
            [44.605,3.9]
            ]));

Result:

Querying Kuzzle HQ:  [ 'Montpellier, France', 'Montpellier Millenaire' ]
Kuzzle team favorite pub: [ 'Montpellier, France', 'Around Kuzzle HQ' ]
Hangout spots: [ 'Montpellier, France',
  'Montpellier Millenaire',
  'Around Kuzzle HQ' ]