point-in-polygon

What is point-in-polygon?

The point-in-polygon npm package is a utility for determining whether a given point lies inside a polygon. This can be useful in various applications such as geographical mapping, collision detection in games, and more.

What are point-in-polygon's main functionalities?

Check if a point is inside a polygon

This feature allows you to check if a given point is inside a specified polygon. The function returns true if the point is inside the polygon and false otherwise.

const inside = require('point-in-polygon');
const point = [1, 1];
const polygon = [[0, 0], [2, 0], [2, 2], [0, 2]];
console.log(inside(point, polygon)); // true

Other packages similar to point-in-polygon

point-in-polygon-hao

The point-in-polygon-hao package provides similar functionality to point-in-polygon, allowing you to check if a point is inside a polygon. It is a lightweight and efficient alternative.

robust-point-in-polygon

The robust-point-in-polygon package offers a more robust solution for checking if a point is inside a polygon. It handles edge cases and numerical precision issues better than point-in-polygon.

turf-inside

The turf-inside module is part of the Turf.js library, which provides advanced geospatial analysis tools. It offers more comprehensive geospatial functionalities compared to point-in-polygon, including point-in-polygon checks.

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 coordinates
• polygon should be an array of 2-item arrays of coordinates or a flat array of coordinates
• start is an offset into polygon. default 0
• end is an offset into polygon. default polygon.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