README
point-in-polygon
Determine if a point is inside of a polygon.
This module casts a semi-infinite ray from the inquiry point and counts intersections, based on this algorithm.
If you need a numerically robust solution and are willing to trade some performance for it, use robust-point-in-polygon.
example
var pointInPolygon = require('point-in-polygon');
var polygon = [ [ 1, 1 ], [ 1, 2 ], [ 2, 2 ], [ 2, 1 ] ];
console.log(pointInPolygon([ 1.5, 1.5 ], polygon)); // true
console.log(pointInPolygon([ 4.9, 1.2 ], polygon)); // false
console.log(pointInPolygon([ 1.8, 1.1 ], polygon)); // true
methods
var pointInPolygon = require('point-in-polygon')
var pointInPolygonFlat = require('point-in-polygon/flat')
var pointInPolygonNested = require('point-in-polygon/nested')
pointInPolygon(point, polygon, start=0, end=polygon.length)
Return whether point
is contained in polygon
.
point
should be a 2-item array of coordinatespolygon
should be an array of 2-item arrays of coordinates or a flat array of coordinatesstart
is an offset intopolygon
. default0
end
is an offset intopolygon
. defaultpolygon.length
The flat or nested is detected automatically. Or you can use the specific methods if you want to skip the check.
install
npm install point-in-polygon
license
MIT