Not officially speced yet, but:

see https://github.com/whatwg/html/issues/5431
and
https://github.com/fserb/canvas2D/blob/master/spec/conic-gradient.md

What needs to be done here:

• Basically, checking out https://phabricator.services.mozilla.com/D69465, and rebasing it to trunk (or doing the same changes on top of trunk).
• Adding a new pref near here. It has to be a RelaxedAtomicBool pref, and name should probably be canvas.createConicGradient.enabled or such. Default value should be true, and mirror can be always, I think it's fine as long as we send an intent email as per the exposure guidelines (I can take care of that bit once the patch is ready to land).
• Changing the [Pref="..."] on top of the new function in CanvasRenderingContext2D.webidl to use [Pref="canvas.createConicGradient.enabled"].
• Running the html/canvas/element/fill-and-stroke-styles/2d.gradient.conic.html test, and ensure it passes with your changes. You can do this with ./mach wpt html/canvas/element/fill-and-stroke-styles/2d.gradient.conic.html
• Since it should start passing, testing/web-platform/meta/html/canvas/element/fill-and-stroke-styles/2d.gradient.conic.html.ini should be removed.
• Check whether we need to do the same with html/canvas/offscreen/fill-and-stroke-styles/2d.gradient.conic.html, and the similar metadata (not sure off-hand what's the state of our OffscreenCanvas implementation.

I think that should be it. Feel free to ask questions if you get stuck or something doesn't work as expected. Tim, can you sanity-check and confirm I haven't missed anything?

(In reply to Emilio Cobos Álvarez (:emilio) from comment #2)

I think that should be it. Feel free to ask questions if you get stuck or something doesn't work as expected. Tim, can you sanity-check and confirm I haven't missed anything?

Sounds fine to me. I'm unsure what graphics backend canvas is using, but should be fine as long as it's not Cairo.

Added an option to use ConicGradient API as a preference and removed the corresponding expected FAILing test, over @ntim's implementation.

Added an option to use ConicGradient API as a preference and removed the
corresponding expected FAILing test, over @ntim's implementation.

https://hg.mozilla.org/mozilla-central/rev/cdd65df84242

Rumyra documented this, and her work looks fantastic! See

• https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/createConicGradient
• See https://github.com/mdn/content/issues/1724 for the wider discussion of the work

Please let us know if you think anything else is needed here.