The `@napi-rs/canvas` package has fewer dependencies, which should *hopefully* make installing and using it easier for `pdfjs-dist` end-users. (Over the years we've seen, repeatedly, that `canvas` can be difficult to install successfully.)
Furthermore, this package includes more functionality (such as `Path2D`) which reduces the overall number of dependencies in the PDF.js project.
One point to note is that `@napi-rs/canvas` is a fair bit newer than `canvas`, and has a lot fewer users, however looking at the commit history it does seem to be actively maintained.
Note that I've successfully tested the [Node.js examples](https://github.com/mozilla/pdf.js/tree/master/examples/node), in particular the `pdf2png` one, with this patch applied and things appear to work fine.
Please see:
- https://www.npmjs.com/package/@napi-rs/canvas
- https://github.com/Brooooooklyn/canvas
This unifies the various factory-options, since it's consistent with `CMapReaderFactory`/`StandardFontDataFactory`, and ensures that any needed parameters will always be consistently provided when creating `CanvasFactory`/`FilterFactory`-instances.
As shown in the modified example this may simplify some custom implementations, since we now provide the ability to access the `CanvasFactory`-instance used with a particular `getDocument`-invocation.
