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0.6.9 • Public • Published

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Javascript library for 2d geometry

FlattenJS is a javascript library (about 50 Kb minified) for manipulating abstract geometrical shapes like point, vector, line, segment, circle, arc and polygon. Shapes may be organized into Planar Set - searchable container which support spatial queries.

FlattenJS provides a lot of useful methods and algorithms like finding intersections, checking inclusion, calculating distance, apply transformations and more. Polygon model is rather comprehensive and supports multi polygons with many islands and holes. Edges of polygon may be circular arcs or segments. Some algorithms like Boolean Operations and Offset, implemented in separate packages.

This library designed to work in any modern browser as well as under nodejs. It is written in plain javascript with es6 syntax elements. You can use es5 precompiled bundled package (added in v0.6.2) if you need to support old browsers.

TypeScript users may take advantage of static type checking with typescript definition file index.d.ts included into the package.

FlattenJS does not concern too much about visualization. Anyway, all objects have svg() methods, that returns a string which may be inserted into SVG container. This works pretty well together with d3js library. But it is definitely possible to create bridges to other graphic libraries.

The best way to start working with FlattenJS is to use awesome Observable javascript interactive notebooks. There are several FlattenJS tutorials published in Observable Notebooks, see below.

Full documentation may be found here

Important note

This package is not supported and will be deprecated soon. Consider moving to the scoped version @flatten-js/core.


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npm install --save flatten-js


Package may be required in different ways:

Require as es6 module:
    import Flatten from 'flatten-js';
Require as CommonJS package (nodejs)
    const Flatten = require('flatten-js');
Require minified package precompiled into UMD format.

Observable notebooks requires this format.

    const Flatten = require('flatten-js.umd.min.js');
Require precompiled to es5 package in Commonjs2 format.
    import Flatten from "flatten-js/dist/flatten.commonjs2"

This package is not minified.

This is the way you have to consume the package for React library, at least when you use create-react-library starter kit:

    Some third-party packages don't compile their code to ES5 before publishing to npm.
    This often causes problems in the ecosystem because neither browsers (except for most modern versions)
    nor some tools currently support all ES6 features.
    We recommend to publish code on npm as ES5 at least for a few more years.

You can see example of FlattenJS + React usage in flatten-react-demo project. It is live here. Just clone it from the GitHub, install dependencies and start working using npm start or compile it to production using npm run build.


After module required, you can create some construction:

    // extract object creators
    let {point, circle, segment} = Flatten;
    // make some construction
    let s1 = segment(10,10,200,200);
    let s2 = segment(10,160,200,30);
    let c = circle(point(200, 110), 50);
    let ip = s1.intersect(s2);

You may test the code above also in NPM RunKit


  1. Getting Started
  2. Messing Around
  3. Planar Set
  4. polygons

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