Fabric Js on OffScreenCanvas

fabric.js package with OffScreenCanvas support to run in webworker

Fabric.js

Fabric.js is a framework that makes it easy to work with HTML5 canvas element. It is an interactive object model on top of canvas element. It is also an SVG-to-canvas parser.

Using Fabric.js, you can create and populate objects on canvas; objects like simple geometrical shapes — rectangles, circles, ellipses, polygons, or more complex shapes consisting of hundreds or thousands of simple paths. You can then scale, move, and rotate these objects with the mouse; modify their properties — color, transparency, z-index, etc. You can also manipulate these objects altogether — grouping them with a simple mouse selection.

Non-Technical Introduction to Fabric

Fabric.js allows you to easily create simple shapes like rectangles, circles, triangles and other polygons or more complex shapes made up of many paths, onto the HTML <canvas> element on a webpage using JavaScript. Fabric.js will then allow you to manipulate the size, position and rotation of these objects with a mouse. It’s also possible to change some of the attributes of these objects such as their color, transparency, depth position on the webpage or selecting groups of these objects using the Fabric.js library. Fabric.js will also allow you to convert an SVG image into JavaScript data that can be used for putting it onto the <canvas> element.

Contributions are very much welcome!

Goals

• Unit tested (1150+ tests at the moment, 79%+ coverage)
• Modular (~60 small "classes", modules, mixins)
• Cross-browser
• Fast
• Encapsulated in one object
• No browser sniffing for critical functionality
• Runs under ES5 strict mode
• Runs on a server under Node.js (active stable releases and latest of current) (see Node.js limitations)
• Follows Semantic Versioning

Supported browsers

• Firefox 4+
• Safari 5+
• Opera 9.64+
• Chrome (all versions)
• Edge (chromium based, all versions)
• IE11 and Edge legacy, not supported. Fabric up to 5.0 is written with ES5 in mind, but no specific tests are run for those browsers.

You can run automated unit tests right in the browser.

History

Fabric.js started as a foundation for design editor on printio.ru — interactive online store with ability to create your own designs. The idea was to create Javascript-based editor, which would make it easy to manipulate vector shapes and images on T-Shirts. Since performance was one of the most critical requirements, we chose canvas over SVG. While SVG is excellent with static shapes, it's not as performant as canvas when it comes to dynamic manipulation of objects (movement, scaling, rotation, etc.). Fabric.js was heavily inspired by Ernest Delgado's canvas experiment. In fact, code from Ernest's experiment was the foundation of an entire framework. Later, Fabric.js grew into a collection of distinct object types and got an SVG-to-canvas parser.

Installation Instructions

$ bower install fabric

Note: If you are using Fabric.js in a Node.js script, you will depend from node-canvas.node-canvas is an html canvas replacement that works on top of native libraries. Please follow the instructions located here in order to get it up and running.

$ npm install fabric --save

After this, you can import fabric like so:

const fabric = require("fabric").fabric;

Or you can use this instead if your build pipeline supports ES6 imports:

import { fabric } from "fabric";

NOTE: es6 imports won't work in browser or with bundlers which expect es6 module like vite. Use commonjs syntax instead.

See the example section for usage examples.

1. Install Node.js

2. Build distribution file [~77K minified, ~20K gzipped]

    $ node build.js

   2.1 Or build a custom distribution file, by passing (comma separated) module names to be included.

      $ node build.js modules=text,serialization,parser
      // or
      $ node build.js modules=text
      // or
      $ node build.js modules=parser,text
      // etc.

   By default (when none of the modules are specified) only basic functionality is included. See the list of modules below for more information on each one of them. Note that default distribution has support for static canvases only.

   To get minimal distribution with interactivity, make sure to include corresponding module:

      $ node build.js modules=interaction

   2.2 You can also include all modules like so:

      $ node build.js modules=ALL

   2.3 You can exclude a few modules like so:

      $ node build.js modules=ALL exclude=gestures,image_filters

3. Create a minified distribution file

    # Using YUICompressor (default option)
    $ node build.js modules=... minifier=yui
   
    # or Google Closure Compiler
    $ node build.js modules=... minifier=closure

4. Enable AMD support via require.js (requires uglify)

    $ node build.js requirejs modules=...

5. Create source map file for better productive debugging (requires uglify or google closure compiler).More information about source maps.

    $ node build.js sourcemap modules=...

   If you use google closure compiler you have to add sourceMappingURL manually at the end of the minified file all.min.js (see issue https://code.google.com/p/closure-compiler/issues/detail?id=941).

    //# sourceMappingURL=fabric.min.js.map

6. Ensure code guidelines are met (prerequisite: npm -g install eslint)

    $ npm run lint && npm run lint_tests

1. Install Node.js

2. Install NPM, if necessary

3. Install NPM packages

    $ npm install

4. Run test suite

Make sure testem is installed

    $ npm install -g testem

Run tests Chrome and Node (by default):

    $ testem

See testem docs for more info: https://github.com/testem/testem

Demos

• Demos
• Kitchensink demo
• Benchmarks

Who's using Fabric?

Documentation

Documentation is always available at http://fabricjs.com/docs/.

Also see official 4-part intro series, presentation from BK.js and presentation from Falsy Values for an overview of fabric.js, how it works, and its features.

Optional modules

These are the optional modules that could be specified for inclusion, when building custom version of fabric:

• text — Adds support for static text (fabric.Text)
• itext — Adds support for interactive text (fabric.IText, fabric.Textbox)
• serialization — Adds support for loadFromJSON, loadFromDatalessJSON, and clone methods on fabric.Canvas
• interaction — Adds support for interactive features of fabric — selecting/transforming objects/groups via mouse/touch devices.
• parser — Adds support for fabric.parseSVGDocument, fabric.loadSVGFromURL, and fabric.loadSVGFromString
• image_filters — Adds support for image filters, such as grayscale of white removal.
• easing — Adds support for animation easing functions
• node — Adds support for running fabric under node.js, with help of jsdom and node-canvas libraries.
• freedrawing — Adds support for free drawing
• erasing — Adds support for object erasing using an eraser brush
• gestures — Adds support for multitouch gestures with help of Event.js
• object_straightening — Adds support for rotating an object to one of 0, 90, 180, 270, etc. depending on which is angle is closer.
• animation — Adds support for animation (fabric.util.animate, fabric.util.requestAnimFrame, fabric.Object#animate, fabric.Canvas#fxCenterObjectH/#fxCenterObjectV/#fxRemove)

Additional flags for build script are:

• requirejs — Makes fabric requirejs AMD-compatible in dist/fabric.js. Note: an unminified, requirejs-compatible version is always created in dist/fabric.require.js
• no-strict — Strips "use strict" directives from source
• no-svg-export — Removes svg exporting functionality
• sourcemap - Generates a sourceMap file and adds the sourceMappingURL (only if uglifyjs is used) to dist/fabric.min.js

For example:

node build.js modules=ALL exclude=json no-strict no-svg-export

Examples of use

Adding red rectangle to canvas

<!DOCTYPE html>
<html>
<head>
</head>
<body>
    <canvas id="canvas" width="300" height="300"></canvas>

    <script src="lib/fabric.js"></script>
    <script>
        var canvas = new fabric.Canvas('canvas');

        var rect = new fabric.Rect({
            top : 100,
            left : 100,
            width : 60,
            height : 70,
            fill : 'red'
        });

        canvas.add(rect);
    </script>
</body>
</html>

Helping Fabric

• Fabric on Bountysource
• Fabric on CodeTriage
• Contributing

Staying in touch

Follow @fabric.js, @kangax or @AndreaBogazzi on twitter.

Questions, suggestions — fabric.js on Google Groups.

See Fabric questions on Stackoverflow, Fabric snippets on jsfiddle or codepen.io.

Fabric on LibKnot.

Get help in Fabric's IRC channel — irc://irc.freenode.net/#fabric.js

Credits

• Andrea Bogazzi for help with bugs, new features, documentation, GitHub issues
• Ernest Delgado for the original idea of manipulating images on canvas
• Maxim "hakunin" Chernyak for ideas, and help with various parts of the library throughout its life
• Sergey Nisnevich for help with geometry logic
• Stefan Kienzle for help with bugs, features, documentation, GitHub issues
• Shutterstock for the time and resources invested in using and improving fabric.js
• And all the other GitHub contributors

MIT License

Copyright (c) 2008-2015 Printio (Juriy Zaytsev, Maxim Chernyak)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.