[dfox]

Do not do this unless you do not have any other choice. Preferrably use whatever native barcode support of the printer involved, if it does not have that, just generate the barcode as vector image or bitmap with a resolution that is a integer fraction of the printers resolution. Generating correct Code128 as a SVG is about the same amount of work as generating the correct input for some sort of barcode font (the hard part is determining the switches between character sets, not generating bars from bytes).

[alex_suzuki]

Shameless plug for my web-based Zint frontend: https://barcode.new (in-browser WASM)

I wrote it specifically because most online barcode generators don’t support vector output or suck in some other way: ads, signup necessary, code payload exposed to server-side processing etc.

[pwdisswordfishs]

Aside from obfuscating the source code to sell licenses, how does this benefit from WASM?

Barcodes have been generated for decades on low-resource embedded devices. Even what would have been a modest-to-low-end machine 25 years ago would have no problem handling the compute needed for this job.

On this end, it just looks like the user has to deal with the penalty of dealing with 1 MB of resources when hitting the main page.

[alex_suzuki]

The benefit of WASM in this case is that you can wrap a mature library written in C/C++ (in this case, Zint), and run it in a runtime that supports WASM, e.g. the browser. There's plenty of people who occasionally need to create barcodes, and not in some industrial, automated way, and a browser is just an easy way to accomplish that. Yes, you have 1MB loaded when you load the page, but hopefully that will be served from a cache.

[Theodores]

As a connoisseur of SVG, I like the approach, the results, the use of Zint and WASM. That said, there are a few opportunities.

The version string isn't needed these days, nor the XML header or the doctype.

The code/url/page title can go in the SVG title, to make it show on mouseover.

The id=barcode is also superfluous. Since id codes should be unique, this could be a problem when many QR codes exist on a page.

The background rectangle does not need x=0, y=0 since that is implied.

The 'hard coding' of the black and white is what you want to avoid any dark mode issues, however, I would still use currentColor and transparent rather than black, just to put myself in a world of dark/light mode pain, fixed in CSS.

[alex_suzuki]

This is super cool, thank you!

The SVG is actually generated by Zint itself, only lightly patched in the wrapper. Zint is a pretty old barcode generator (not meant disrespectfully, quite the opposite actually), it's quite possible that some of its decisions when rendering to SVG are out of date or very conservative. The use of id/global namespace does feel like a potential pain point though, which I will take up with the upstream project.

[pwdisswordfishs]

> There's plenty of people who occasionally need to create barcodes

> hopefully that [1MB] will be served from a cache

[nolroz]

One MEGAbyte?? How could you!?

[tfpgh]

This is amazing!

[mark-r]

I once worked at a company that used a Code39 font cartridge in HP Laserjets. When HP stopped putting font cartridge slots in their printers, I had the task of intercepting print jobs and detecting the font selection sequence, then taking the text and converting it to a Code128 bitmap graphic. It wasn't hard at all, kind of fun actually.

[darksim905]

'font' cartridge? the what now?

[EvanAnderson]

You're one of today's lucky 10,000.

Like another poster said, laser printers "back in the day" were freestanding computers with various communications interfaces that happened to have fancy paper handling and printing peripherals attached. In the case of the Apple LaserWriter, for example, it was arguably a more powerful computer[0] than the Mac machines of the day that were sending print jobs to it.

There were different ROM "personalities" available for laser printers, some of which came on pluggable cartridges.

Check these links out:

- https://www.pagetable.com/?p=1673

- https://www.pagetable.com/?p=1721

- https://www.pagetable.com/?p=1850

Michael Steil, the blogger responsible for those links, has done work extracting code and PostScript data out of some of those old cartridges. It's a really cool aspect of retrocomputing many people aren't even aware of.

[0] https://web.archive.org/web/20240404213221/https://lowendmac...

[darksim905]

commented elsewhere but The links you shared are pretty cool, a little before my time (born late 80s). That's kinda neat, it makes me think of a post on HN some time back by Donald Knuth on the letter S and the technical challenges back then about that as a letter, mathmatically. I'm guessing given that, that's why printers needed these modules and were set up this way. Neat!

[mark-r]

The LaserWriter was like something from the future compared to the Laserjet. I think they used the same Canon print engine, but the HP was far less sophisticated. It only used bitmap fonts, nothing scalable like Adobe's Type 1 for Postscript. Knuth probably used a supercomputer for his typesetting.

[mark-r]

And if you don't know the origin of the phrase "lucky 10,000" then it's your lucky day too!

https://xkcd.com/1053/

[ValdikSS]

In the dark ages, when printers were PostScript and more powerful (and expensive) than the computers which printed on them, you added fonts by installing additional hardware modules, similar to a game console cartridge.

[darksim905]

The links someone else shared are pretty cool, a little before my time (born late 80s). That's kinda neat, it makes me think of a post on HN some time back by Donald Knuth on the letter S and the technical challenges back then about that as a letter, mathmatically. I'm guessing given that, that's why printers needed these modules and were set up this way. Neat!

[xp84]

Up until like 15 years ago, lots of laser printers even had RAM slots as well. Populating them with extra RAM made them behave better when printing big PDFs and stuff.

[benj111]

Don't say it too loudly. I'm sure HP would love to introduce 'Font as a service'

[wildzzz]

They were ROM cards that stored extra typefaces or other PostScript functions.

[jpitz]

I did exactly that ( bitmap ) for a retail application back in ~2000. It was just a couple of constants for the stop and start sigils plus an array of bits for the digits....it was a quick work.

[OrangeMusic]

I'm sorry, after reading your comment several times I still don't understand why we shouldn't use this. What is the problem with it?

[Theodores]

You have given me the encouragement I needed...

Recently I put some 8-bit graphics in SVG using lines and stroke dash arrays. I also got them animated, in a space efficient way, by keeping the lines that do not change from frame to frame. (I now have Maria and Willy from 'Jet Set Willy' for the wait after a form is submitted, plus a few Space Invaders. I am resisting the urge to do Pac-Man ghosts, but I will invent a need for them...)

Since an SVG can be a mystery box full of CSS, SMIL, Javascript and 'foreign object' imports, I am tempted to give it a go, so that a CSS variable is passed to the depths of the shadow DOM in a URL fragment or query string, to magically return either a barcode or a QR code.

This will take a little while, but I am keen to give it a go. In some ways, SVG is like 'Duplo LEGO' with the Libre Barcode as a font more like 'LEGO Technik', requiring vastly more skill.

Just because you can doesn't mean that you should, plus there are many barcode libraries that I know well, so why reinvent the wheel?

The typical barcode library usually comes with fluff, formats and libraries that I don't need. Hence 'qr.svg#upc-number' with it just being one file has appeal.

I am not yet up to speed on the latest AI toys, however, given the problem space is well defined, could I just ask AI chat bot to churn out the code for this in a matter of seconds, for it to encapsulate the logic in an SVG? Would it know how to specify 'crisp edges' and what the deal is with aspect ratio?

Similarly, could I also ask the AI nicely to create my own barcode font?

These seem manageable problems for todays trillion-dollar wonder tech, it is not as if I am asking for a cure for cancer or anything hard, yet I lack confidence in an AI solution, and feel I might as well work it out myself, given my goal is learning SVG rather than prompting.

My lack of confidence is the AI solution is due to the scarcity of people writing online about doing cool things with CSS variables, URL fragments and code in SVG. A Google search does not show 'stroke dash array' things for QR codes and online QR code generators create lots of fully fledged rect-angles, that lack the space efficiency or human-readability of my prefered approach, even if gzip doesn't care.

Sorry for bringing AI into everything, I just have my doubts that the new toys are that capable when it comes to novel solutions.