# cubic2quad

> Approximate cubic Bezier curve with a number of quadratic ones

Latest version **1.2.1** (published 2021-05-20) · MIT license · 0 weekly downloads

## Install

```sh
npm install cubic2quad
pnpm add cubic2quad
yarn add cubic2quad
bun add cubic2quad
```

## Health

**Score 30/100 (F)** — status: abandoned.

Positive: no vulnerabilities; high maintenance score.

Warnings: low downloads; no types; no esm support.

Negative: abandoned.

## Facts

| | |
|---|---|
| Version | 1.2.1 |
| Published | 2021-05-20 |
| First published | 2015-10-27 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 0 |
| Unpacked size | 21 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 36 |
| Maintainers | vitaly |
| Keywords | cubic, quad, bezier |

## Links

- npm: https://www.npmjs.com/package/cubic2quad
- Repository: https://github.com/fontello/cubic2quad
- Homepage: https://github.com/fontello/cubic2quad#readme
- Issues: https://github.com/fontello/cubic2quad/issues
- npm.io page: https://npm.io/package/cubic2quad

## Recent versions

- 1.2.1 (latest) — 2021-05-20
- 1.2.0 — 2021-05-19
- 1.1.1 — 2017-05-08
- 1.1.0 — 2016-10-26
- 1.0.0 — 2015-10-27

## README

cubic2quad
==========

[![CI](https://github.com/fontello/cubic2quad/actions/workflows/ci.yml/badge.svg)](https://github.com/fontello/cubic2quad/actions/workflows/ci.yml)
[![NPM version](https://img.shields.io/npm/v/cubic2quad.svg?style=flat)](https://www.npmjs.org/package/cubic2quad)
[![Coverage Status](https://img.shields.io/coveralls/fontello/cubic2quad/master.svg?style=flat)](https://coveralls.io/r/fontello/cubic2quad?branch=master)

> Aproximates cubic Bezier curves with quadratic ones.

This package was done to create TTF fonts (those support quadratic curves only).
Generated curves have the same tangents angles at the ends. That's important to
keep result visually smooth.


Algorithm
---------

Logic is similar to one from [FontForge](https://fontforge.github.io/bezier.html).

Steps:

1. Split quadratic curve into _k_ segments (from 2 at start, to 8 max).
2. Approximate each segment with tangents intersection approach (see
   [picture](http://www.timotheegroleau.com/Flash/articles/cubic_bezier/quadratic_on_cubic_1.gif) in [article](http://www.timotheegroleau.com/Flash/articles/cubic_bezier_in_flash.htm)).
3. Measure approximation error and increase splits count if needed (and max not reached).
   - set 10 points on each interval & calculate minimal distance to created
     quadratic curve.

Usage
-----

```js
var cubic2quad = require('cubic2quad');
// Input: (px1, py1, cx1, cy1, cx2, cy2, px2, py2, precision)
var quads = cubic2quad(0, 0, 10, 9, 20, 11, 30, 0, 0.1);
```

It converts given quadratic curve to a number of quadratic ones. Result is:

    [ P1x, P1y, C1x, C1y, P2x, P2y, C2x, C2y, ..., Cnx, Cny, P{n+1}x, P{n+1}y ]

where _Pi_ are base points and _Ci_ are control points.


Authors
-------

- Alexander Rodin - [@a-rodin](https://github.com/a-rodin)
- Vitaly Puzrin - [@puzrin](https://github.com/puzrin)


License
-------

[MIT](https://github.com/fontello/cubic2quad/blob/master/LICENSE)

---
_Source: https://npm.io/package/cubic2quad · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._