![image of piet logo](./misc/piet-logo.png)

# Piet: a 2D graphics abstraction
[![Crates.io](https://img.shields.io/crates/v/piet)](https://crates.io/crates/piet)
[![Documentation](https://docs.rs/piet/badge.svg)](https://docs.rs/piet)
[![Build Status](https://travis-ci.com/linebender/piet.svg?branch=master)](https://travis-ci.com/linebender/piet)

Cross-platform 2D graphics.

The Piet project consists of a core crate (`piet`) which describes a 2D graphics API,
and a number of "backends", which implement that API on top of the built-in
2D graphics system of a given platform. This allows the same drawing code to be
used on different platforms, without having to bundle a full 2D renderer.

The motivation for this crate is set forth in this [blog post]. It is used as
the basis of [Druid], a cross-platform GUI toolkit.

A companion for Bézier path representation and geometry is [kurbo].

## Getting started

Running the examples requires that submodules be checked out. From the root
directory, run

```sh
git submodule update --init
```

## Contributing

### Piet is in maintenance mode.

Piet has largely stabilized, and no major API additions are planned by the
original developers. Bug fixes and performance improvements are welcome.

If there is a significant feature you would like to add that can be discussed.
For a new feature to be considered, there must be a plan for how it would be
implemented in at least the coregraphics, direct2d, and cairo backends, and the
actual implementation should include support for at least two of these.

For questions and discussions we use a zulip chat instance at [xi.zulipchat.com][zulip]
under the #piet stream.

## Backends

*For cross-platform use, the [`piet-common`][] crate reexports the most
appropriate implementation for the current target.*

#### `piet-cairo` [![crates.io](https://img.shields.io/crates/v/piet-cairo)](https://crates.io/crates/piet-cairo)

The `piet-cairo` crate depends on the [cairo library][]. A simple test of the cairo
backend is to run `cargo run --example test-picture 0` in the `piet-cairo` directory,
which should produce an image file called `cairo-test-00-2.00.png`.

#### `piet-coregraphics` [![crates.io](https://img.shields.io/crates/v/piet-coregraphics)](https://crates.io/crates/piet-coregraphics)

The `piet-coregraphics` crate works on macOS only. A simple test of the coregraphics
backend is to run `cargo run --example test-picture 0` in the `piet-coregraphics` directory,
which should produce an image file called `coregraphics-test-00-2.00.png`.

#### `piet-direct2d` [![crates.io](https://img.shields.io/crates/v/piet-direct2d)](https://crates.io/crates/piet-direct2d)

The `piet-direct2d` crate works on Windows only. A simple test of the direct2d
backend is to run `cargo run --example test-picture 0` in the `piet-direct2d` directory,
which should produce an image called `d2d-test-00-2.00.png`.

#### `piet-svg` [![crates.io](https://img.shields.io/crates/v/piet-svg)](https://crates.io/crates/piet-svg)
#### `piet-web` [![crates.io](https://img.shields.io/crates/v/piet-web)](https://crates.io/crates/piet-web)

## Inspirations

Piet's interface is largely inspired by the [Skia Graphics Library] as well as
the [C++ 2D graphics api proposal] although piet aims to be much more lightweight and modular.

## The Name

The library is named after [Piet Mondrian]. It is abstract and intended to
be used for drawing lots of rectangles.

[blog post]: https://raphlinus.github.io/rust/graphics/2018/10/11/2d-graphics.html
[Druid]: https://github.com/xi-editor/druid
[kurbo]: https://github.com/linebender/kurbo
[zulip]: https://xi.zulipchat.com
[Skia Graphics Library]: https://skia.org
[C++ 2D graphics api proposal]: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0267r8.pdf
[Piet Mondrian]: https://en.wikipedia.org/wiki/Piet_Mondrian
[`piet-common`]: https://crates.io/crates/piet-common
[cairo library]: https://www.cairographics.org/download/
