@foreground/canvas

This repository provides a canvas implementation that works on the browser and node, leveraging the canvas package.

It replaces document.createElement('canvas') and new Image() with createCanvas() and createImage(), respectively.

Installation

$ npm install @foreground/canvas

By default, binaries for macOS, Linux and Windows will be downloaded. If you want to build from source, use npm install --build-from-source and see the Compiling section below.

The minimum version of Node.js required is 6.0.0.

Compiling

If you don't have a supported OS or processor architecture the module will be compiled on your system. This requires several dependencies, including Cairo and Pango.

For detailed installation information, see the canvas package wiki. One-line installation instructions for common OSes are below.

| OS | Command | | ------- | --------------------------------------------------------------------------------------------------------------- | | OS X | Using Homebrew:brew install pkg-config cairo pango libpng jpeg giflib librsvg pixman | | Ubuntu | sudo apt-get install build-essential libcairo2-dev libpango1.0-dev libjpeg-dev libgif-dev librsvg2-dev | | Fedora | sudo yum install gcc-c++ cairo-devel pango-devel libjpeg-turbo-devel giflib-devel | | Solaris | pkgin install cairo pango pkg-config xproto renderproto kbproto xextproto | | OpenBSD | doas pkg_add cairo pango png jpeg giflib | | Windows | See the wiki | | Others | See the wiki |

Mac OS X v10.11+: If you have recently updated to Mac OS X v10.11+ and are experiencing trouble when compiling, run the following command: xcode-select --install. Read more about the problem on Stack Overflow. If you have xcode 10.0 or higher installed, in order to build from source you need NPM 6.4.1 or higher.

Usage example

The following code can be used in node and in the browser.

import { createCanvas, createImage } from "@foreground/canvas";

const canvas = createCanvas();

canvas.width = 100;
canvas.height = 100;

const context = canvas.getContext("2d");

if (context) {
  context.fillStyle = "red";
  context.fillRect(25, 25, 50, 50);

  const image = createImage();

  new Promise<void>((resolve) => {
    image.crossOrigin = "anonymous";
    image.addEventListener("load", () => resolve());
    image.src = url;
  }).then(() => {
    context.drawImage(image, 0, 0, 100, 100);
  });
}