@Glrx The problem with standard is that no one cares about it. People want to see the same results as in the browser or better. That's why resvg usually tries to mimic browsers and not standard.
And in general, there are too many things in SVG that are not defined at all or poorly defined. My tests suite has 48 tests where the correct result is basically unknown.

@Glrx as mentioned here, it's not that simple. I guess I would have to add at least a minimal support.

@JoKalliauer resvg doesn't support emojis yet.

There are a lot of SVG files that are trivial and should display reasonably on any browser.

I suspect that most modern browsers have sufficient SVG support.

Sometime soon I'll try some CSS @media support.

It doesn't understand tspan[data-e~="a" i] either. Will fix it soon. a:link and :lang are ignored. The first one is a surprise, the second one is a known issue. Everything else works as expected.

resvg fails to load this CSS at all. I guess because of ?* CSS 3 selectors */. librsvg indeed uses a way better CSS parser.

@Glrx Hi. As the author of resvg, I would like to point out some limitations of serving SVG directly. Yes, browsers are great, but they are not perfect either. Both Chrome and Firefox have tons of issues with SVG rendering. Even the textPath feature you've mentioned is actually badly supported. The situation with filters is pretty bad in Chrome. And not as great with complex text either. No browser is supporting enable-background (deprecated in SVG 2 through).

how many files on commons would break if we switched away from rsvg tomorrow?

@Milimetric Can you expand your question a bit? What this checker should do and what exactly it should catalog?

resvg only seems to be packaged in sid though, which is a bigger problem...

@Aklapper resvg performance should be close, but it's basically impossible to compare. There are just too many differences and nuances.

CSS support is still pretty bad, yes. Only simple selectors are supported. Just like in librsvg.
I plan to rewrite a CSS parsing, but not sure when it will be available. Maybe even this year.

A new version of resvg was released. Now it supports textPath (example, example), writing-mode (example), BIDI reordering (example) and better letter-spacing (example).

@Aklapper resvg has a prebuilt viewer too. So you can test it right away.

Would this file break? It contains "Ü", but the character is in the <title> element.

Does resvg accept viewBox="0 0 500 500" without other dimension attributes?

@Jc86035 SVG without a specified size is an undefined behavior. There are no tests for this yet, so I'm not sure how good the librsvg and other implementations are.

Given https://phabricator.wikimedia.org/T40010#4432284 I think the most promising next step is to wait a few more months and migrate thumbor to the buster and the rust-based new librsvg

Thanks for a detailed answer!

@Glrx Hello again.

RazrFalcon might has optimised resvg for his own hardware

@Krenair The software is indeed changed but in a bad way. At the moment Inkscape and Batik are extremely slow. At least according to my own benchmarks. Batik can be faster if we use it as a daemon, because JVM startup is very slow, but I'm not sure how much memory it will consume in that way.

Yes, the overflow attribute is marked as unsupported, but only because its too generic. resvg simply does not support all elements that can have overflow yet.

Hi, I'm the resvg author.