Is it possible to use paperjs in nodejs without using Cairo? - node.js

Question

I need to "read" an array of some paperjs paths in nodejs and get their dimension. I wanted to use paper npm module but saw that it has a dependency to Cairo.
As I'm deploying to heroku it is a little difficult to use Cairo. I know its possible but I want to know if its really necessary just for "reading" the dimensions of a path group.

Answer 1

A present day answer: Yes it's possible.
———
To quote from the docs:
Paper.js comes in three different versions on NPM: paper, paper-jsdom and paper-jsdom-canvas. Depending on your use case, you need to require a different one:
paper is the main library, and can be used directly in a browser context, e.g. a web browser or worker.
paper-jsdom is a shim module for Node.js, offering headless use with SVG importing and exporting through jsdom.
paper-jsdom-canvas is a shim module for Node.js, offering canvas rendering through Node-Canvas as well as SVG importing and exporting through jsdom.
→ If you don't require rendering to canvas, paper-jsdom should do the trick (which doesn't need Cairo)
———
Important note:
If I understood correctly this means you can't use PaperScript, but have to use JavaScript directly. This will affect how you have to write code:
new paper.Path() instead of new Path()
Create project manually using paper.setup()
No mathematical operators (+ - * / %)
... (More info in the docs)
———
A simple example to create a line, log its bounding box size (and also export the SVG):
Note: I used this with the current Node LTS (v14.16.1)
package.json
{
"name": "paper-jsdom-example",
"main": "index.js",
"dependencies": {
"paper-jsdom": "^0.12.15"
}
}
index.js
const paper = require('paper');
const fs = require('fs');
var size = new paper.Size(300, 300)
paper.setup(size);
var path = new paper.Path();
path.strokeColor = '#348BF0';
var start = new paper.Point(100, 100);
var end = new paper.Point(200, 200);
path.moveTo(start);
path.lineTo(end);
console.log('width', path.bounds.width, 'height', path.bounds.height);
var svg = paper.project.exportSVG({asString:true});
fs.writeFileSync('punchline.svg', svg);