Socket
Socket
Sign inDemoInstall

delaunator

Package Overview
Dependencies
1
Maintainers
29
Versions
19
Alerts
File Explorer

Advanced tools

Install Socket

Detect and block malicious and high-risk dependencies

Install

delaunator

An incredibly fast JavaScript library for Delaunay triangulation of 2D points


Version published
Maintainers
29
Weekly downloads
2,423,459
decreased by-4.63%

Weekly downloads

Package description

What is delaunator?

The delaunator npm package is a fast library for Delaunay triangulation of 2D points. It is used to triangulate a set of points into a mesh of triangles, which is a fundamental operation in many geometric algorithms. The package is particularly useful in graphics, geographical information systems (GIS), and for performing various computational geometry tasks.

What are delaunator's main functionalities?

Triangulation

This feature allows you to perform Delaunay triangulation on an array of points. The 'triangles' property of the resulting object contains the indices of the points that form the triangles.

const Delaunator = require('delaunator');
const points = [[0, 0], [1, 0], [1, 1], [0, 1]];
const delaunay = Delaunator.from(points);
console.log(delaunay.triangles);

Hull

This feature provides the convex hull of the input points as an array of point indices that are in the hull. The hull is the outermost 'shell' of the triangulation.

const Delaunator = require('delaunator');
const points = [[0, 0], [1, 0], [1, 1], [0, 1]];
const delaunay = Delaunator.from(points);
console.log(delaunay.hull);

Coordinates Conversion

Delaunator can also take a flat array of coordinates and perform triangulation. This is useful when working with data that is not already structured as an array of points.

const Delaunator = require('delaunator');
const coords = [0, 0, 1, 0, 1, 1, 0, 1];
const delaunay = Delaunator.from(coords);
console.log(delaunay.triangles);

Other packages similar to delaunator

Readme

Source

Delaunator Build Status

An incredibly fast and robust JavaScript library for Delaunay triangulation of 2D points.

Delaunay triangulation example

Projects based on Delaunator

  • d3-delaunay for Voronoi diagrams, search, traversal and rendering (a part of D3).
  • d3-geo-voronoi for Delaunay triangulations and Voronoi diagrams on a sphere (e.g. for geographic locations).

Example

const coords = [168,180, 168,178, 168,179, 168,181, 168,183, ...];

const delaunay = new Delaunator(coords);
console.log(delaunay.triangles);
// [623, 636, 619,  636, 444, 619, ...]

Install

Install with NPM (npm install delaunator) or Yarn (yarn add delaunator), then import as an ES module:

import Delaunator from 'delaunator';

To use as a module in a browser:

<script type="module">
    import Delaunator from 'https://cdn.skypack.dev/delaunator@5.0.0';
</script>

Or use a browser UMD build that exposes a Delaunator global variable:

<script src="https://unpkg.com/delaunator@5.0.0/delaunator.min.js"></script>

API Reference

new Delaunator(coords)

Constructs a delaunay triangulation object given an array of point coordinates of the form: [x0, y0, x1, y1, ...] (use a typed array for best performance).

Delaunator.from(points[, getX, getY])

Constructs a delaunay triangulation object given an array of points ([x, y] by default). getX and getY are optional functions of the form (point) => value for custom point formats. Duplicate points are skipped.

delaunay.triangles

A Uint32Array array of triangle vertex indices (each group of three numbers forms a triangle). All triangles are directed counterclockwise.

To get the coordinates of all triangles, use:

for (let i = 0; i < triangles.length; i += 3) {
    coordinates.push([
        points[triangles[i]],
        points[triangles[i + 1]],
        points[triangles[i + 2]]
    ]);
}
delaunay.halfedges

A Int32Array array of triangle half-edge indices that allows you to traverse the triangulation. i-th half-edge in the array corresponds to vertex triangles[i] the half-edge is coming from. halfedges[i] is the index of a twin half-edge in an adjacent triangle (or -1 for outer half-edges on the convex hull).

The flat array-based data structures might be counterintuitive, but they're one of the key reasons this library is fast.

delaunay.hull

A Uint32Array array of indices that reference points on the convex hull of the input data, counter-clockwise.

delaunay.coords

An array of input coordinates in the form [x0, y0, x1, y1, ....], of the type provided in the constructor (or Float64Array if you used Delaunator.from).

delaunay.update()

Updates the triangulation if you modified delaunay.coords values in place, avoiding expensive memory allocations. Useful for iterative relaxation algorithms such as Lloyd's.

Performance

Benchmark results against other Delaunay JS libraries (npm run bench on Macbook Pro Retina 15" 2017, Node v10.10.0):

 uniform 100kgauss 100kgrid 100kdegen 100kuniform 1 milliongauss 1 milliongrid 1 milliondegen 1 million
delaunator82ms61ms66ms25ms1.07s950ms830ms278ms
faster‑delaunay473ms411ms272ms68ms4.27s4.62s4.3s810ms
incremental‑delaunay547ms505ms172ms528ms5.9s6.08s2.11s6.09s
d3‑voronoi972ms909ms358ms720ms15.04s13.86s5.55s11.13s
delaunay‑fast3.8s4s12.57stimeout132s138s399stimeout
delaunay4.85s5.73s15.05stimeout156s178s326stimeout
delaunay‑triangulate2.24s2.04sOOM1.51sOOMOOMOOMOOM
cdt2d45s51s118s17stimeouttimeouttimeouttimeout

Papers

The algorithm is based on ideas from the following papers:

Robustness

Delaunator should produce valid output even on highly degenerate input. It does so by depending on robust-predicates, a modern port of Jonathan Shewchuk's robust geometric predicates, an industry standard in computational geometry.

Ports to other languages

Keywords

FAQs

Last updated on 24 Jan 2024

Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Install

Related posts

SocketSocket SOC 2 Logo

Product

  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap

Stay in touch

Get open source security insights delivered straight into your inbox.


  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc