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Explainer https://developer.mozilla.org/en-US/docs/Web/CSS/font-variant-position Specification https://drafts.csswg.org/css-fonts-4/#propdef-font-variant-position Summary The font-variant-position CSS property controls the use of alternate, smaller glyphs that are positioned as superscript or subscript. Motivation Font-variant-position property allows users to control usage of typographic superscript and subscript glyphs. Currently font-variant-position is implemented without synthesis functionality and affects only fonts that have superscript or subscript glyphs (“sups”/”subs” opentype feature); i.e. if the font doesn’t have superscript/subscript then setting font-variant-position to “super”/“sub” won’t synthesize superscript and subscript glyphs, therefore won’t change anything. Subscript and superscript glyphs can be also activated using the font-feature-settings property, however using font-variant-position property might be more reasonable since it cascades like a regular CSS property and with the font-feature-settings, if the element inherits the “sups” or “subs” value, users need to activate/deactivate other features that were also defined in font-feature-settings of the parent element. Implementing the synthesis part would be complex and it is questionable if it is worth the cost since synthesized glyphs may look unnatural and synthesis of the font-variant-position property is at risk in the spec <https://drafts.csswg.org/css-fonts-4/#:~:text=The%20following%20features,variant%2Dposition%20property>. Also Safari supports font-variant-position property without synthesis functionality as well. This feature is implemented behind the ‘experimental’ flag and is part of Interop 2022. Shipping this feature will provide a higher stable score for Interop and will decrease the stable vs. experimental score difference.Since Chrome is the last browser to ship this, this will enable broader usage of the feature on the web. Blink component Blink>Fonts <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EFonts> Search tags font-variant-position <https://chromestatus.com/features#tags:font-variant-position>, subscript glyphs <https://chromestatus.com/features#tags:subscript%20glyphs>, superscript glyphs <https://chromestatus.com/features#tags:superscript%20glyphs>, sub <https://chromestatus.com/features#tags:sub>, super <https://chromestatus.com/features#tags:super> TAG review Already shipped in other browsers, see below, no TAG review required. TAG review status Not applicable, existing standard, shipped in other UAs Risks Interoperability and Compatibility Gecko: Shipped/Shipping https://bugzilla.mozilla.org/show_bug.cgi?id=1024804 Gecko has implemented the feature with the synthesis functionality. WebKit: Shipped/Shipping https://bugs.webkit.org/show_bug.cgi?id=148413 WebKit has implemented the feature without the synthesis functionality. Web developers: No signals Other signals: - Activation None expected; Feature already implemented in other browsers. Debuggability Same as any other CSS property, css_properties.json will be rolled to DevTools during development. Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, 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, following tests are testing property implementation: https://wpt.fyi/results/css/css-fonts/font-variant-position.html https://wpt.fyi/results/css/css-fonts/font-variant-position-01.html https://wpt.fyi/results/css/css-fonts/font-variant-position-02.html https://wpt.fyi/results/css/css-fonts/font-variant-position-03.html https://wpt.fyi/results/css/css-fonts/parsing/font-variant-position-valid.html https://wpt.fyi/results/css/css-fonts/parsing/font-variant-position-computed.html https://wpt.fyi/results/css/css-fonts/parsing/font-variant-valid.html Flag name FontVariantPosition Requires code in //chrome? False Tracking bug https://bugs.chromium.org/p/chromium/issues/detail?id=1212668 Estimated milestones No milestones specified Anticipated spec changes None expected Link to entry on the Chrome Platform Status https://chromestatus.com/feature/5067180721307648 -- 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 blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAAO7W_C-aHBXYr1mp%3DiJkTQEPgP-isxxv-u-Uv%3DyO4Mp9b_j5Q%40mail.gmail.com.
