Hmmm how does it know whether to mirror or not to mirror? And what will be mirrored? Is there an example/demo of failure, success and fix-dependent success renderings? Does the dir="rtl" attribute have to be specified specifically on <math>, or will it inherit the directionality of the ancestor? Hebrew, as far as I am aware, uses left-to-right for written math, so inheriting regardless of the language would not be correct for Hebrew, I think?
☆*PhistucK* On Tue, Oct 14, 2025 at 2:53 PM Chromestatus < [email protected]> wrote: > *Contact emails* > [email protected], [email protected] > > *Specification* > https://w3c.github.io/mathml-core/#layout-of-operators > > *Summary* > Support for character-level and glyph-level mirroring when rendering > MathML operators in right-to-left mode. When using RTL mode some operators > can be mirrored by changing them to another code point (e.g. a right > parentheses becomes a left parentheses). This is character-level mirroring, > with equivalences defined by Unicode's `Bidi_Mirrored` property. There are > operators that have no appropriate mirroring character. Glyph-level > mirroring applies in this case, with the `rtlm` font feature, where another > glyph can replace it in a mirrored context. Some existing implementations > mirror the original glyph directly, but this may change the meaning for > asymmetrical characters, such as the clockwise contour integral. > > *Blink component* > Blink>MathML > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EMathML%22> > > *Web Feature ID* > mathml <https://webstatus.dev/features/mathml> > > *TAG review* > None > > *TAG review status* > Not applicable > > *Risks* > > > *Interoperability and Compatibility* > None > > *Gecko*: Shipped/Shipping ( > https://bugzilla.mozilla.org/show_bug.cgi?id=945183) Working > implementation shipping under the `mathml.rtl_operator_mirroring.enabled` > feature. Planning to send an intent to ship. > > *WebKit*: In development Already has character-level mirroring. rtlm > support is being worked on for the harfbuzz ports. > > *Web developers*: No signals > > *Other signals*: > > *WebView application risks* > > Does this intent deprecate or change behavior of existing APIs, such that > it has potentially high risk for Android WebView-based applications? > None > > > *Goals for experimentation* > > > *Ongoing technical constraints* > None > > *Debuggability* > None > > *Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, ChromeOS, Android, and Android WebView)?* > Yes > > *Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* > Yes > New tests: - Character-level mirroring: checks that when switching text > direction the codepoints of the characters change to the corresponding > BidiMirrored equivalent (e.g. right to left parentheses) - Glyph-level > mirroring: checks that the rtlm font feature is supported and that a > specific glyph is used for certain characters when switching text direction. > > *Flag name on about://flags* > None > > *Finch feature name* > MathMLOperatorRTLMirroring > > *Requires code in //chrome?* > False > > *Tracking bug* > https://issues.chromium.org/issues/40120782 > > *Estimated milestones* > DevTrial on desktop 140 > DevTrial on Android 140 > > *Link to entry on the Chrome Platform Status* > https://chromestatus.com/feature/6317308531965952 > > *Links to previous Intent discussions* > Intent to Prototype: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/686d2758.170a0220.a35ba.00d7.GAE%40google.com > > > This intent message was generated by Chrome Platform Status > <https://chromestatus.com>. > > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68ee55b8.050a0220.2a8282.0245.GAE%40google.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68ee55b8.050a0220.2a8282.0245.GAE%40google.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABc02_JdGb5qv3A3JEs0SCbkK7NtJ3F74HN1EeyODbavy9YkcQ%40mail.gmail.com.
