Intent to Prototype: New @font-face descriptors to override font metrics

[Xiaocheng Hu]

Contact emails xiaoc...@chromium.org Explainer https://jsfiddle.net/mro3c9tz/ https://www.youtube.com/watch?v=h_0T3SiISZg Design docs/spec Specification: https://github.com/w3c/csswg-drafts/issues/4792 https://bit.ly/39qATQ4 TAG review Not TAG-reviewed yet at this very early stage. Summary Introduce new @font-face descriptors to override the default font metrics (ascent, descent, etc.) Motivation 1. Improve interoperably across browsers and operating systems, so that the same font always looks the same on the same site, regardless of OS or browser. See [1] 2. Align metrics between two web fonts present simultaneously, but for different glyphs. This use case example comes from the crostini terminal [2] 3. Override font metrics for a fallback font to emulate a web font, in order to minimize Cumulative Layout Shift. [1] https://github.com/w3c/csswg-drafts/issues/4792 [2] https://groups.google.com/a/chromium.org/g/blink-dev/c/mmXMwbmBc5g/m/LAxjFsJPAgAJ Risks

Interoperability and Compatibility This new feature is still at a very early stage. We will follow the standards process and hopefully reach a resolution at CSSWG, so that the interop risks are minimized. Gecko: No signal WebKit: No signal Web developers: No signals

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? No Will be added when the spec stabilizes. Link to entry on the Chrome Platform Status https://chromestatus.com/feature/5651198621253632

This intent message was generated by Chrome Platform Status.