We could do our own SVG support. But the SVG spec is huge: resvg is 20k LoC (not including dependencies like the XML parser or the vector renderer). Properly supporting SVG is probably about as big a project as the rest of the layout/rendering engine combined. I would at least recommend forking resvg rather than starting from scratch.

It's worth nothing that the resvg crate itself is relatively lightweight (~4.5k LOC - but that is small for SVG!) wrapper around the usvg crate (~17k LOC) by the same author, that mostly serves to integrate usvg with tiny-skia for rendering. USVG

There are also the following libraries (both of which also depend on usvg):

vello_svg which we are using in blitz and is only ~400 LOC (+usvg). It's definitely missing a lot of features (like filters), but we've gotten decent results on real-world SVGs we've tried.
pathfinder_svg mentioned above.

usvg does have a couple of issues that make it not ideal:

It bundles it's own XML parser. However, I've looked into this and it looks like it would be relatively easy to abstract this out and make it work with any XML tree implementation like Stylo. We'd also be interested in this for Blitz.
Text support is pretty naive. However, it does allow wrappers to implement their own (and text support is behind a feature flag, so it doesn't need to be compiled at all if you're not using it). It might also be worth considering simply improving the text support in usvg. We're currently using the built-in text support in Blitz, but are considering building something better using parley crate. Servo could potentially do the same using it's own text support.
It doesn't support animated or scripted SVGs, or CSS styling of SVGs. This is probably the biggest argument for Servo building it's own, although this is more relevant for inline SVGs, and is much less of an issue for SVGs linked via <img> elements (this issue).

Finally, this runs into the same issue as <canvas> support: that Servo doesn't have good vector path rendering capabilities, and really needs to pick a library for this. IMO, we could do much worse than picking tiny-skia which is small, widely used, runs everywhere, and fastish (certainly much faster than raquote). Other options would include Vello and Skia itself, but both are much heavier weight and each come with their own tradeoffs.

(does anyone know what Firefox uses for vector rendering?)

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SVG images #33310

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