SPIRO(3) Library Functions Manual SPIRO(3)

# [NAME](#NAME)

libspiro - A clothoid to bezier spline converter

# [SYNOPSIS](#SYNOPSIS)

**#include <spiroentrypoints.h>** and then compile and link with **-lspiro**

# [DESCRIPTION](#DESCRIPTION)

**Spiro** library for curve design which simplifies drawing of beautiful curves.

**libspiro** takes an array of spiro control points which can be easier for an artist to create and modify, and then converts these into a series of bezier splines which can then be used in the myriad of ways the world has come to use beziers.

*spiroentrypoints.h* has technical information on how to connect with *libspiro* and further information and example code can be found at *http://github.com/fontforge/libspiro*

# [REPORTING PROBLEMS](#REPORTING_PROBLEMS)

Before reporting a problem, please check the libspiro web site to verify that you have the latest version of *libspiro*

Great care was taken to maintain backwards compatibility so it is recommended to upgrade if you experience problems with earlier *libspiro* versions.

# [LIBSPIRO LICENSE](#LIBSPIRO_LICENSE)

**libspiro** originated from spiro code (in 2007) found in **ppedit** which is a pattern plate editor for Spiro splines. **ppedit** was/is Copyright (C) 2007 Raph Levien. GNU GPL version 2 or higher. **ppedit** was later relicensed also as Apache-2 MIT code in May of 2019. This relicensing is fine since all **ppedit** was written by Raph Levien in 2007. Copyright allows for this. Unfortunately, this re-licensing of **ppedit** has caused some confusion in assuming that this relicensing also applies to **libspiro** which is not valid and does not apply.

**libspiro** was based on **ppedit** spiro code from 2007 (which was GNU GPL2 version 2 or higher) and built into a usable library at *http://libspiro.sourceforge.net/* Copyright (C) 2007 George Williams. GNU GPL version 2 or higher. This license also applies to the included Java files which have been forked into javascript and typeset files seen elsewhere.

**libspiro** was later picked up in 2013 and continued with further development and improvements at *http://github.com/fontforge/libspiro*

**libspiro** is now Copyright (C) 2013... as GNU GPL version 3 or higher.

# [AUTHORS](#AUTHORS)

Please see *AUTHORS* file for everyone involved in creating and improving this *libspiro*

Further details (on why and what) can also be seen in git history as well as the Changelog and README files.

2022-Jul-22

---

Document: libspiro(3) from libspiro 20240903-r8 (Chainguard OS)
Source: https://github.com/fontforge/libspiro