An SVG is all you need
199 points
10 hours ago
| 30 comments
| jon.recoil.org
| HN
iamsal
6 hours ago
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Even though the article is mostly talking about visualizations, but I thought I'd share that I did at one point build a dance choreography software that renders the UI entirely SVG. I was surprised as to how well that worked.

If you're curious, it's called StageKeep, and you can find it here. https://stagekeep.com/

The original project used React Three Fiber, but refactored it to SVG for reasons I don't quite remember. I was inspired by signed distance functions, and the fact that one function could have such an outsized visual effect. Although the software doesn't use SDFs, but I like the idea of atomic functions that accepts some input, and outputs SVG.

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jfengel
6 hours ago
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Wow, that is really cool. As a stage director I touch on choreography a bit. It would be really cool to pre-plan blocking with something like that.
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Animats
1 hour ago
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That's good for blocking. Then, for movement, what? Probably not Labanotation.
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great_tankard
4 hours ago
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Very cool. Are you a dancer yourself?
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iamsal
2 hours ago
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Heh, thanks.

I wish I was a dancer.

That said, the founder who hired me to work on this is a dancer.

He hired me because he liked the fact that during the interview, when asked "what do you know about dance", I responded "I used to crip walk when I was in high school", so I was the top choice just for that, haha.

Edit: the Founder is Axel Villamil, and he's super charismatic. Y'all are going to love him. Here's him trying to raise an investment round https://www.instagram.com/reel/CyhL5kitUbD/

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tylervigen
3 hours ago
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Two years ago I re-vamped my "Spurious Correlations" side project, which is mostly just a bunch of charts. However, I couldn't find a charting software I liked that would display clean, simple visuals with the constraints I wanted. (I had used pCharts and HighCharts in the past, but didn't like charting in Javascript or PHP.)

I decided to "roll my own" and write Python scripts that outputted SVG markup. I was worried this would go about as well as every other "roll your own" project does, but was pleasantly surprised. It is surprisingly easy to output reliable, good-looking SVG graphics using Python. If you are making a chart, everything is just math.

The infinite scalability is almost just a happy upside to the simplicity of creating the visualizations, which is annoying in raster format. It made me like SVG even more.

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crabmusket
1 hour ago
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If anyone is looking for a clean JS charting framework, I highly recommend Observable Plot.

It's from the creator of D3 and it's much easier than using raw D3. I've been using it outside the Observable platform for debug charts and notebooks, and I find its output crisp and its API very usable.

It doesn't try to have all the bells and whistles, and I'm not even sure if it has animations. But for the kind of charts you see in papers and notebooks I think it covers a lot.

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eru
3 hours ago
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It's a bit sad that Postscript never caught on as much as it could have. In an alternate timeline, it could have been the HTML (and SVG) we got in ours.
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shakna
3 hours ago
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Postscript is still everywhere. Its just out of sight, being used as a compile target.

PDF may have "officially" replaced it, but it is still embedded almost everywhere you look.

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eru
3 hours ago
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PDF is a sad replacement for PS. As far as I can tell, it was an attempt to obscure PS, because alternative vendors were getting better as Postscript than the originators.

(There was some justification in terms of 'Oh, a binary format like PDF is more space efficient.' But PDF never really was more efficient than compressed PS.)

It's not that PS has vanished, but PS isn't nearly as 'everywhere' as HTML came to be.

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f30e3dfed1c9
1 hour ago
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From the perspective of someone who worked in printing and publishing starting in the 1980s, there's more to it than that. PostScript was and is terrific as a page description language and as a printer control language. It absolutely revolutionized the printing business. For the first time, you could get complete pages (as opposed to unpaginated galleys) out of high-end imagesetters.

But it was not all that good as a way to send documents to be printed elsewhere. Postscript files were in some ways too dependent on the printer they targeted, so the person creating the PS file had to know too much about the printer that would be used to print it: its resolution and optimal halftone screen frequencies, media sizes, etc. With high-resolution output on photographic film costing around $10 per foot, mistakes could be expensive as well as time-wasting.

Fonts could also be a problem. Ideally, the PS file would contain all the fonts it required but this did not fit very well with the terms of most font licenses. And some applications would include a copy of every font used once on each page on which it was used. This was in line with Adobe's recommended Document Structuring Conventions and had the advantage of making pages within the file independent of one another, but for documents with hundreds of pages, this could add up fast and make the PS file literally hundreds of times larger than if all the fonts were included just once. With small storage media and slow network links, this was a real problem.

The "P" in PDF is for portable, and these are the problems it solved. Unlike a PS file, a PDF file is not targeted for a specific printer model, and most font licenses allowed the licensee to include subsetted fonts in PDF files. I personally prepared PS files for a few thousand books to be printed at various places around the US and later, PDF files for thousands more. There is no comparison: PDF was and is better in every way for this purpose.

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tambourine_man
2 hours ago
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PDF is also a lot less powerful, purposefully so. You can start an infinite loop just by double-clicking a PS file, for instance.

It is extremely useful to have a full programing language as a file format, though.

I miss macOS’s Preview.app auto-converting PS to PDF when double-clicked. It was a way to easily distribute a document that could randomize question orders each time it opened, print multiple bingo cards from a single file, etc.

The stack-based and reverse Polish notation thing was also fun.

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leephillips
3 hours ago
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Thanks for making that website. I used examples from it in the first day of my statistics course ("by the end of this course you won't make these kinds of mistakes").
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some_guy_nobel
7 hours ago
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I agree with the author when they write:

""" In my idealistic vision of how scientific publishing should work, each paper would be accompanied by a fully interactive environment where the reader could explore the data, rerun the experiments, tweak the parameters, and see how the results changed. """

I do like seeing larger labs/companies releasing research full of SVGs. In recent memory, I quite liked this from NVIDIA:

https://research.nvidia.com/labs/dbr/blog/illustrated-evo2/

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_heimdall
3 hours ago
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The idea of rerunning experiments only seems feasible when the entire experiment was based on modelling, presumably modelling that can easily/quickly be rerun in a browser environment.

The idea of being able to view and parse the dataset in different ways is interesting though, effectively allowing readers to interpret the experiment's resulting dataset from different angles than the author published.

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mmooss
5 hours ago
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Without the OP's proposed use of SVG, what format would someone use? PDFs won't handle it well - unless PDF's interactivity capabilities are much better than I think. We never developed a client-side multimedia file format; all we have are text formats like Word and PDF, which embed images decently, and embed multimedia and interactivity (beyond form filling) in awkwardly and in a limited manner.
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steezeburger
4 hours ago
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What's wrong with SVG? Notebooks have their issues but are kinda this conceptually. I guess FLAs and Flash too. But you say we never developed a "client-side multimedia file format". Is that not exactly what html + js are for?
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mmooss
3 hours ago
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I mean the equivalent of a Word document: a file I can reasonably edit, including editing the multimedia and interactive/dynamic content, save, email, put on a thumb drive or Dropbox, etc.
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fooker
6 hours ago
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Interactive and SVGs don't really mix, although intuitively it would seem that they do. Rendering remotely complex SVGs tale multiple seconds, while any kind of interactivity demands ~30+ frames per seconds.

Without interactivity, postscript is vector graphics too.

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dekhn
5 hours ago
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How complex are you talking about? I've done animations with hundreds of elements and it's fine.
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Grimblewald
3 hours ago
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I'd be curious to know what classes as complex for you, since ive done some frankly crazy stuff with svg's, which outperformed any raster implementation. Ultimately, poor performance was always my fault, especially initially when i was still treating it with paradigms better suited to the world of raster graphics.
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nanolith
7 hours ago
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Around 15 years ago, I built a barbecue controller. This controller had four temperature probes that could be used to check the temperature of the inner cooking chamber as well as various cuts of meat. It controlled servos that opened and closed vents and had a custom derived PID algorithm that could infer the delayed effects of oxygen to charcoal.

Anyway, of relevance to this thread is that the controller connected to the local wireless network and provided an embedded HTTP server with an SVG based web UI that would graph temperatures and provided actual knobs and dials so that the controller could be tweaked. SVG in the browser works nicely with Javascript.

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tambourine_man
2 hours ago
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This sounds awesome. Did you ever filmed it working?
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ludwigschubert
9 hours ago
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The first Distill publication[0] made tasteful use of minimal interactivity through JavaScript/d3.js[1] on top of SVGs. Many of the illustrations were initially drawn in GUI editors.

(Outstanding work by Shan Carter; it’s what I first saw of his style and it’s what made me want to join his team.)

[0] https://distill.pub/2016/augmented-rnns/ [1] https://github.com/distillpub/post--augmented-rnns/blob/mast...

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codedokode
3 hours ago
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Downsides of using SVG:

- cannot wrap text

- cannot embed font glyphs - your SVG might be unreadable if the user doesn't have the font installed. You can convert letters to curves, but then you won't be able to select and edit text. It's such an obvious problem, yet nobody thought of it, how? Photoshop solved this long time ago - it saves both text and its rendering, so the text can always be rendered.

- browsers do not publish, which version and features they support

- may contain Javascript and references to external resources, which makes it difficult to view in a secure, isolated environment

One of solutions is having two SVGs: author version, which you edit in Inkscape and which uses Inkscape-specific extensions, and published version, which is generated from the first, that uses only basic features and has text converted to curves.

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geokon
6 minutes ago
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plenty of other problems

- They often render differently in different browsers and other renderers. It's very frustrating to get consistent results (like a PDF). In complex diagrams I'd say it's basically impossible

- Renderers that are fast usually lack many features

- Nobody other than the browser seems to actually have all the features?

- You can link an SVG within an SVG (to make a lightweight composite image). But if you have two levels of indirection then all renderers I've tried will refuse to render the SVG

- Inkscape is basically the only good editor on Linux and it easily runs out of memory and crashes for complex images

- Complex SVGs eat all your RAM in Chromium (only marginally better in Firefox)

- Basic things like arrows from Inkscape will not render anywhere else

I still use SVGs all the time, b/c there are no good alternatives, but it's a crappy standard and I try to keep all my images/diagrams extremely simple

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bobbylarrybobby
2 hours ago
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Safari supports base64-embedding font files in a <style>’s @font-face {} (iirc it's something like `@font-face { src: url('data:application/x-font-woff;charset=utf-8;base64,...'); }`) that can then be referenced as normal throughout the SVG. I don't recommend this though, nobody wants to deal with 500KB SVGs.
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_ache_
7 hours ago
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I really like SVG, I did a lot of things with it and some interesting ones. The only blame I have is that it is sometime slow.

Like for QR Code, precise maps or +100 pixels wide squares. More than 100 "DOM" elements and it will take multiple seconds to show.

The animations also are slow too, compared to canvas, plain CSS or Lottie but nothing very cursed, it's mostly fine.

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newcup
6 hours ago
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I embedded a chess engine in SVG image of a chess board (https://github.com/jnykopp/svg-embedded-chess) so that the engine moved the pieces automatically and played against itself, just by viewing the SVG.

This was done for a friend of mine who made an art installation that projected like some 50x20 (can’t remember exactly) of these images in a grid on a wall, for perpetual chess madness.

The number of chess SVGs a laptop’s browser was able to run simultaneously did feel suprisingly low, but luckily it was enough for that particular piece of art.

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jonludlam
8 hours ago
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Author here: I've just made a ninja edit of the post as it didn't really make clear a quite important point - the SVG is literally 20 years old, and still works, astonishingly. I'm not sure much else I wrote around the time would still work without some editing!
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ianbooker
7 hours ago
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The reverse is kind of true: In the beginning, SVGs were not really an option since it lacked adoption across all major browsers, or more specifically its integration was very heterogenous.

So a SVG you authored 20 years ago for some browser will likely work everywhere today.

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VladVladikoff
5 hours ago
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Except in an email. Because email is pain.
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krisoft
3 hours ago
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I once solved a machining problem using SVG and a bit of javascript and python.

I was prototyping an orrery. It involved cutting out a lot of ad-hoc gears and frame bits on my CNC out of a sheet of brass. It was relatively easy to generate the g-code for the individual parts using fusion360, but then it was a lot of faff to zero the machine such that it cut the part from a fresh part of the brass sheet without wasting too much metal in between the parts. It involved a lot of guesswork, and eyeballing. And even with that there was a lot of brass “wasted” between the parts especially since you could only move your part in x-y but not easily rotate it.

As a solution I wrote a python script which converted the g-code into svg, and a simple one page website where i could drag the svg around and rotate it on a visual representation of the sheet. Once i found a good safe spot for it to be cut the page told me the x,y, theta coordinates for it. And then with a separate python script i could transform the g-code using the coordinates and rotation. This way the svg renderer was doing the heavy lifting of visualising the cutting paths, and i only needed to concentrate on the relatively easy transforms.

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WillAdams
9 hours ago
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Ages ago, when doing the instructions for the opensource CNC Shapeoko v2 it became necessary (after the project was featured w/ a full page in _Popular Mechanics_ magazine to cater to users who could not visualize as well as the early adopters were able to, so the diagrams were made interactive:

https://github.com/shapeoko/Docs/blob/gh-pages/content/tPict...

Used to be if that was opened in a web browser one could click on the parts list to show/hide or highlight/unhighlight the matching items in the diagram.

Done using Inkscape if memory serves.

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sedatk
8 hours ago
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That looks cool!
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orliesaurus
8 hours ago
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My day job involves building dashboards, and SVGs have been invaluable for crisp icons and graphs... the portability across sizes is a blessing, but some of the more exotic filter effects still fail in certain browsers.

ALSO I've run into security reviews that flag inline SVGs because they can embed scripts... would love to see more tooling to lint and sanitize them before deployment.

BUT seeing a two-decade-old vector still render correctly gives me confidence that the core spec is solid.

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lucgommans
7 hours ago
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> would love to see more tooling to lint and sanitize them before deployment

Sanitisation is one of two possible defences, the other being script execution controls or sandboxing. E.g., if you serve vector images on a web server, set a Content Security Policy header¹ for all your images that simply denies all scripting. You can also run it from a dummy domain ('origin') with nothing valuable on it (like how domains such as googleusercontent.com and githubusercontent.com are being used)

For sanitisation, DOMPurify² is the only widely used and tested library that I know of. It could use more bindings for other languages but, if you can call into it, it can go in your deployment pipeline. (Disclosure: I've worked with some of the people at Cure53, but not on this project)

You can also combine the approaches for defence in depth

¹ https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/CSP

² https://github.com/cure53/DOMPurify

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e12e
6 hours ago
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> would love to see more tooling to lint and sanitize them before deployment

Did you see?:

https://github.com/cloudflare/svg-hush

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greazy
7 hours ago
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what dashboard software do you recommend?
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sbrother
1 hour ago
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I once built a music game that basically ran entirely on SVG. We hacked Musescore to attach the same UUID to both the note head in SVG and the MusicXML object in two different output modes, and then used that to synchronise the sheet music scrolling with a MIDI stream. If you're interested you can see it in action in our failed Kickstarter video from like eight years ago: https://www.youtube.com/watch?v=vgbB5Q4-dgY
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martijn_himself
9 hours ago
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>They are supported on just about every device and platform

Except they aren't. I recently used a simple SVG in a background and Safari wasn't able to render it properly so after trying lots of different things I gave up and used different sizes of raster images instead.

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stanac
8 hours ago
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SVGs also are mostly unsupported for og:image tags (dependents on the app/browser). I know it's supper specific and I am not even sure if open graph is standardized protocol or not, but it's used everywhere.
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airstrike
8 hours ago
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yeah, I was super disappointed to find that out when I built previews for https://hexrgb.pages.dev
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avsm
9 hours ago
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What was the SVG that didn't work? In Jon's example in the original post, the SVG he embeds there was one he wrote in around 2005. That's a pretty impressive run for it to render 20 years on...
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SoKamil
7 hours ago
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They are also not supported on iOS native apps. We use pdfs for vectors.
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thingsilearned
4 hours ago
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I love SVG! Recently I needed to render markdown in SVG and found no library existed for that yet so I released one:

github: https://github.com/davefowler/markdown-svg playground: https://markdown-svg-production.up.railway.app

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notpushkin
4 hours ago
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I assume the goal is to get rid of all foreignObject uses eventually? (Otherwise it would be easier yo render one big foreignObject and convert everything to HTML)

Anyways, impressive, but what I’d really love to see is flexbox for SVG ;)

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tracerbulletx
9 hours ago
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This feels a little bit like discovering frontend software development? I guess we're done with the trend of being scared of bundling features and running them in the browser close to the user with JavaScript.
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absoluteunit1
7 hours ago
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I love working with SVGs.

We use SVGs on https://typequicker.com/press for the blog post hero images.

This way - even if the user changes themes, the colors of the image will be consistent with whatever theme is currently active. Also - the loading time is near-instant since we don't need to fetch the img file for the blog post image - just render the svg.

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xxmarkuski
9 hours ago
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I use ChatGPT to compress SVGs, in particular QR codes. Many QR code SVG generators produce inefficient SVGs, and conventional SVG compressors often lack the understanding required for some compression techniques. ChatGPT can replace alignment indicators with <use> elements.

Is there a way to embed the data encoded in the QR code directly within the image? This would allow the data to be parsed directly by the browser, eliminating the need for computer vision to decode it again. Going further, for web images QR codes could be efficiently encoded and rendered by the browser.

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ktpsns
8 hours ago
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I am not sure about your use case. There exist many JS libraries which will generate client side QR codes. How many of them do you handle that you optimize for file size? Or is it just an academic interest?

SVGs are XML so technically, yes, you can just embed your visually encoded payload data with namespaces attributes and elements. If you don't want to use namespaces, you can use off-canvas texts, hidden/opacity=0 texts or even XML comments. You can even use the regular metadata section of SVGs. You can make the whole QR code within the SVG a clickable link.

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paularmstrong
7 hours ago
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> I use ChatGPT to compress SVGs, in particular QR codes

Why? svgomg.net exists, uses far fewer resources, and is going to give you much better results.

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amelius
7 hours ago
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I recently found out that it is surprisingly hard to convert an SVG file that consists of series of line segments into a list of those line segments in Python.

I tried with ChatGPT and Claude but both were not able to find a solution that respects the entire specification, especially transforms.

Initially, my expectation was that there must be a library for this kind of thing, but alas.

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boothby
6 hours ago
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I find svg.path to be good for parsing path data

  https://pypi.org/project/svg.path/
For actually parsing the file, there are a number of options (in the end, it's an XML file and I tend to treat it as such)
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nicoburns
5 hours ago
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Not sure about python, but https://docs.rs/usvg in Rust is pretty good
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nish__
6 hours ago
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Can't you do it by hand pretty easily? It's a list of coordinates separated by spaces. For example: "100,100 100,200 200,200 200,100"
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amelius
6 hours ago
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No, the specification is more complicated, for example elements (and sub-elements recursively) can have transforms applied to them.
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boothby
6 hours ago
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Excellent point. Inkscape has (had?) a feature to simplify SVG files, which pushed transformations down the tree. I never needed to use this in an automated process, just the occasional file.
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e12e
6 hours ago
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I mean - it's XML so you could go that way and extract the d element from path element?

But there seems to be a lot of SVG specific tooling and code to do this in python?

Eg: https://github.com/RaubCamaioni/svgpath

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nawgz
6 hours ago
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I seem to remember that the DOM nodes themselves expose some pretty useful functions. I think it was in the context of detecting edge crossings for a graph router, but you were able to interact with the computed/rendered coordinates in this context.

Sorry that's not more useful and explicit, it was a while back and never went anywhere.

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ChrisMarshallNY
5 hours ago
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I remember an employee of mine, who was possibly the best engineer I ever knew, wrote up a specification document for his own vignetting algorithm, in Postscript.

The algorithm provided a 100X performance improvement over the classic Monte Carlo stuff that Tokyo had written.

The charts in the document were executable Postscript, running his algorithm.

That got the attention of the Ph.Ds in Tokyo. He was a high school-educated neurodivergent.

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felineflock
4 hours ago
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perilunar
3 hours ago
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"Since SVGs are essentially code, they can embed JavaScript"

Odd thing to say. Everything on a computer is "essentially code", executable or not.

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WorldPeas
10 hours ago
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all we need is keyboard input and audio output and we have (most of) flash back. I may have to look into this in my idle hours
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zamadatix
9 hours ago
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The magic here is happening via the <script> tags, where you have access to the browser APIs like you would an <canvas> instead of <svg>. E.g. here's a sample I forked following the mouse using <svg> with <script> inside https://codepen.io/zamadatix/pen/emZXZKx?css-preprocessor=sc...

Libraries like three.js had SVG rendering as an option but it got deprecated as <canvas> with more direct GPU APIs was a lot more efficient and flexible.

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fragmede
9 hours ago
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JavaScript to catch keypress events and edit the SVG in situ maybe?
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VladVladikoff
3 hours ago
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I have been pushing SVG hard for a decade now, but to be honest AVIF is magic. It even crushes SVG file sizes.
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ivanjermakov
6 hours ago
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> A completely self-contained SVG file can either fetch data from a versioned repository or embed the data directly

But can it read email? https://www.laws-of-software.com/laws/zawinski/

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lucid-dev
9 hours ago
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This is going to really transform some data visualization things I've been thinking about. I've always loved SVG since working with Illustrator and Inkscape back in the day, but I didn't realize how much it could tie in with the modern web and interactivity. Thank you!
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some_guy_nobel
7 hours ago
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SVG has been transforming web-experiences (particularly for viz) for quite some time now, see:

- https://mlu-explain.github.io/neural-networks/

- https://www.nytimes.com/spotlight/graphics

- https://pudding.cool/

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tetris11
9 hours ago
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Surely D3 is what you're referring to
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tanx16
7 hours ago
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Here's a fun older thread on a similar topic - SVG is Turing Complete:

https://news.ycombinator.com/item?id=20980837

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yusufcengiz
5 hours ago
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I love seeing old formats hold up this well. SVG surviving 20 years of browser evolution is a pretty strong argument for “boring tech” done right. It makes me wonder why we don’t see more research papers ship with fully self-contained interactive SVGs today — the tooling and browser performance are better than ever.
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morshu9001
8 hours ago
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An SVG and JS, right? It's not interactive on its own.
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avsm
8 hours ago
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The JS is embedded within the SVG file and not exposed outside it
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zamadatix
2 hours ago
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The JS is exposed in the full page's context the same as if you included a <script> under a <div> instead of <svg>. In much the same way, whether the <script> is before or after the <svg> tag doesn't matter - it's just a script working on a single DOM (with different namespaces for certain elements) either way.
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morshu9001
2 hours ago
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I guess the point is you can give a single .svg file with the js inside. But you can also give a single .html with svg and js inside.
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strickinato
7 hours ago
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Sort of... the SVG is referencing `svgscript.js` which is being fetched from the server (https://jon.recoil.org/blog/2025/12/svgscript.js)
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mogoh
8 hours ago
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> vector graphics in a simple XML format.

Simple? No. SVGs are not simple. If they were simple they weren't so capable.

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drewg123
8 hours ago
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I hate that slack doesn't support svg. So we end up taking screenshots of svg flame graphs when discussing things.
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sturbes
9 hours ago
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I just went down the same rabbit hole, it is totally fun! https://turbek.com/Designing-Interactive-SVGs-with-AI/

TLDR:

- SVG image files: powerful like HTML

- Supported widely in browsers

- Designer tools make SVGs

- SVGs are written in a language

- LLMs are great at manipulating language

- Designers can collaborate interaction into life

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psygn89
9 hours ago
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I don't think LLM's are that great at manipulating SVG unless you mean like small edits like rotation and font size. Cool article though, I'll have to think how I can leverage it.
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