cairo/README.md

# Cairo: Multi-platform 2D graphics library

<https://cairographics.org>

What is cairo
-------------

Cairo is a 2D graphics library with support for multiple output
devices. Currently supported output targets include the X Window
System (via both Xlib and XCB), quartz, win32, and image buffers,
as well as PDF, PostScript, and SVG file output.

Cairo is designed to produce consistent output on all output media
while taking advantage of display hardware acceleration when available
(for example, through the X Render Extension).

The cairo API provides operations similar to the drawing operators of
PostScript and PDF. Operations in cairo include stroking and filling
cubic Bézier splines, transforming and compositing translucent images,
and antialiased text rendering. All drawing operations can be
transformed by any affine transformation (scale, rotation, shear,
etc.).

Cairo has been designed to let you draw anything you want in a modern
2D graphical user interface.  At the same time, the cairo API has been
designed to be as fun and easy to learn as possible. If you're not
having fun while programming with cairo, then we have failed
somewhere---let us know and we'll try to fix it next time around.

Cairo is free software and is available to be redistributed and/or
modified under the terms of either the GNU Lesser General Public
License (LGPL) version 2.1 or the Mozilla Public License (MPL) version
1.1.

Where to get more information about cairo
-----------------------------------------

The primary source of information about cairo is its website:

- <https://cairographics.org>

The latest versions of cairo can always be found at:

- <https://cairographics.org/download>

Documentation on using cairo and frequently-asked questions:

- <https://cairographics.org/documentation>
- <https://cairographics.org/FAQ>

Mailing lists for contacting cairo users and developers:

- <https://cairographics.org/lists>

Roadmap and unscheduled things to do, (please feel free to help out):

- https://cairographics.org/roadmap
- https://cairographics.org/todo

Dependencies
------------

The set of libraries needed to compile cairo depends on which backends are
enabled when cairo is configured. So look at the list below to determine
which dependencies are needed for the backends of interest.

For the surface backends, we have both "supported" and "experimental"
backends. Further, the supported backends can be divided into the "standard"
backends which can be easily built on any platform, and the "platform"
backends which depend on some underlying platform-specific system, (such as
the X Window System or some other window system).

As an example, for a standard Linux build similar to what's shipped by your
distro, (with image, png, pdf, PostScript, svg, and xlib surface backends,
and the freetype font backend), the following sample commands will install
necessary dependencies:

- Debian (and similar):
  - `apt-get build-dep cairo`

- Fedora (and similar):
  - `dnf builddep cairo`

Technically you probably don't need pixman from the distribution since if
you're manually compiling Cairo you probably want an updated pixman as well.
However, if you follow the default settings and install pixman to
/usr/local, your Cairo build should properly use it in preference to the
system pixman.


### Supported, "standard" surface backends

#### image backend (required)

- [pixman](https://cairographics.org/releases) >= 0.30.0 

#### PNG support (preferred)

- [libpng](http://www.libpng.org/pub/png/libpng.html)

#### PDF backend

- [zlib](http://www.gzip.org/zlib)

#### PostScript backend

- [zlib](http://www.gzip.org/zlib)

#### SVG backend

- none

### Supported, "platform" surface backends

#### Xlib backend

- [X11](https://freedesktop.org/Software/xlibs)

#### xlib-xrender backend

- [Xrender](https://freedesktop.org/Software/xlibs) >= 0.6

#### Quartz backend

- macOS >= 10.4 with Xcode >= 2.5

#### Windows backend

- Microsoft Windows Vista or newer.

#### XCB backend

- [XCB](https://xcb.freedesktop.org)

### Font backends (required)

#### freetype font backend

- [freetype](https://freetype.org) >= 2.1.9
- [fontconfig](https://www.freedesktop.org/wiki/Software/fontconfig/)

#### Quartz-font backend

- MacOS X >= 10.4 with Xcode >= 2.5

#### Windows GDI font backend

- Microsoft Windows Vista or newer

#### Windows DirectWrite font backend

- Microsoft Windows 7 or newer

Compiling
---------

See the [`INSTALL`](./INSTALL) document for build instructions.

Licensing
---------

Cairo is released under the terms of either the GNU Lesser General Public
License version 2.1, or the terms of the Mozilla Public License version 1.1.

See the [`COPYING`](./COPYING) document for more information.

History
-------

Cairo was originally developed by Carl Worth <cworth@cworth.org> and Keith
Packard <keithp@keithp.com>. Many thanks are due to Lyle Ramshaw without
whose patient help our ignorance would be much more apparent.

Since the original development, many more people have contributed to cairo.
See the [`AUTHORS`](./AUTHORS) document for as complete a list as we've been
able to compile so far.