Build Parchment as a single HTML file, suitable for downloading

[dfabulich]

Today, Parchment builds as an HTML file with <script> tags linking to various required scripts, and a <link rel=stylesheet> for its CSS.

If Parchment built a single all-in-one HTML file with all required scripts embedded in it, users would be able to download the HTML file and double-click on it to run it offline, without requiring a complex service worker.

It could even be an optional, secondary download, e.g. iplayif.com/parchment.html and then the index.html home page could have a link like this: <a download href=parchment.html>Download Parchment to use it offline</a>

[curiousdannii]

Should be possible, but it's gonna be a big file. With all the engines and all fonts I guess it would be around 10MB. Probably better to zip it up and offer that for download.

[curiousdannii]

Turned out to be quite easy! And only 6MB... It's in the testing branch, and also deployed to
https://curiousdannii.github.io/parchment-testing/dist/single-file/parchment.html
https://curiousdannii.github.io/parchment-testing/dist/single-file/parchment-single-file.zip

The Iosevka fonts are almost 3MB before being base64 encoded. Do you think it's worth including them in the single file mode? I think it's not.

Edit: realised there's no point to including Git or Glulxe when they can't even be chosen instead of Quixe. So that brings the filesize down a bit.

[curiousdannii]

So one option would be to embed only the base font, and rely on the browser faking italics and bold. Here's how that would look.

Real italics and bold:

Faked italics and bold:

Edit: That's what I've done. Regular is embedded, and the browser can fake the others.