{fill,stroke}-opacity should support SVG-in-OT values context-{fill,stroke}-opacity

[upsuper]

I don't find any formal definition of these values... but Gecko supports them... cc @heycam

[highfive]

cc @emilio

[upsuper]

The spec is https://www.microsoft.com/typography/otspec/svg.htm

[nox]

What are the computed values for context-fill-opacity and context-stroke-opacity?

Should stroke-width, stroke-dasharray and stroke-dashoffset also support context-value like the spec you linked says?

[upsuper]

What are the computed values for context-fill-opacity and context-stroke-opacity?

Seems to be some flags in nsStyleSVG::mContextFlags. See nsStyleStruct.h.

Should stroke-width, stroke-dasharray and stroke-dashoffset also support context-value like the spec you linked says?

Yes.

Note that all those values are controlled by pref gfx.font_rendering.opentype_svg.enabled, and there is a test to ensure the effectiveness of that pref. So we probably need to follow that as well.

[nox]

Should we file an issue on the compat spec for these values to be mentioned there?

[upsuper]

Why compat spec? It is nothing about compat, it is a feature we support and don't want to unship. It is just defined in OpenType spec rather than an SVG or CSS spec.

[nox]

@upsuper All I saw was the microsoft domain and I thought it was vendor-specific, disregard that. :)

[upsuper]

That is the OpenType spec hosted on Microsoft's domain. The original draft can be found here: https://dev.w3.org/SVG/modules/fonts/SVG-OpenType.html and there is a link saying the document in Microsoft domain is the spec.

IIRC this is actually something only Gecko implements at the moment.

[kuoe0]

I'm working on this issue on Bug 1338764.

[sviter]

Is it still valid?

[upsuper]

This has been fixed by #17940.