WPT will start passing the following tests when the flag is enabled: https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/TestExpectations?q=file:TestExpectations%20virtual%5C%2Fbackdrop-filter-mirror-edge
wpt.fyi does not show this because the feature is controlled by a flag outside of blink and so couldn't be associated with --experimental-web-platform-features which wpt.fyi uses. On Wed, Jul 24, 2024 at 1:12 PM Daniel Clark <dan...@microsoft.com> wrote: > Is there a specific set of tests under > https://wpt.fyi/results/css/filter-effects?label=master&label=experimental&aligned&q=%2Fcss%2Ffilter-effects%2Fbackdrop-filter- > that highlight this behavior change? I would have expected, for example, > some set of tests to recently start passing in Chrome due to this change, > which would already have been passing in Safari and fail in Firefox. But > there a number of other differences in tests like > backdrop-filter-edge-*.html causing failures such it’s hard to tell what > the real status is. > > > > Or are there just too many other browser differences with backdrop-filter > to make this kind of comparison realistic? > > > > -- Dan > > > > *From:* Robert Flack <fla...@chromium.org> > *Sent:* Wednesday, July 24, 2024 6:41 AM > *To:* blink-dev <blink-dev@chromium.org> > *Subject:* [blink-dev] Web-Facing Change PSA: Update CSS backdrop-filter > to use mirror edgeMode > > > Contact emails > > fla...@chromium.org, michaellud...@google.com > > > Specification > > https://drafts.fxtf.org/filter-effects-2/#backdrop-filter-operation > > > Summary > > The backdrop-filter CSS property applies one or more filters to the > "backdrop" of an element. The "backdrop" basically means all of the painted > content that lies behind the element. A common filter is a blur allowing > designers to construct "frosted glass" dialog boxes, video overlays, > translucent navigation headers, and more. This was initially implemented > the same way as a regular blur, but sampling beyond the edges of the > element allowed colors from the edges to bleed in. The spec was changed to > sample pixels outside the backdrop edges by duplicating the pixels at the > edge. This however, results in extreme flickering of content as it enters > the backdrop edge. The latest spec change mirrors the backdrop when > sampling beyond the edge which allows for a smooth gradual introduction of > new colors at the edges without overweighting on single lines of color. > > > > > Blink component > > Blink>CSS > <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3ECSS> > > > TAG review > > None > > > TAG review status > > Not applicable > > > Risks > > > > > Interoperability and Compatibility > > The specific visual result of a blur backdrop-filter is currently quite > different between Chrome, Firefox and Safari, as such this developers could > not rely on any interoperable behavior today. This change visually aligns > closely to Safari's filter - if not identical, so should bring those two in > rough alignment. We agreed upon this new behavior in the CSSWG resolutions > for the new edgeMode[1] and using this edgeMode for backdrop-filter[2]. [1] > https://github.com/w3c/fxtf-drafts/issues/527 [2] > https://github.com/w3c/fxtf-drafts/issues/374 > > > > *Gecko*: No signal ( > https://github.com/mozilla/standards-positions/issues/1051) > > *WebKit*: No signal ( > https://github.com/WebKit/standards-positions/issues/372) This change is > visually very similar to the blur being applied in Safari which doesn't > have the flickering issues that our current duplicate edgeMode has. > > *Web developers*: No signals There have been many negative signals about > the current duplicate behavior that this change resolves (all duplicated > into the main bug): https://issues.chromium.org/issues/40040614 There is > positive sentiment for Safari's behavior on > https://issues.chromium.org/issues/40666159 and > https://issues.chromium.org/issues/40040614 which this change in behavior > aligns with. > > *Other signals*: > > > Ergonomics > > There are no known ergonomic risks. > > > > > Activation > > This should be an improvement to the quality of blur backdrop-filters that > developers are already using and further allow developers to adopt them > without worrying about the flickering edge cases of the duplicate filter. > Developers don't need to do anything other than use the backdrop-filter > property. > > > > > Security > > There are no known security risks. This is replacing one sampling > algorithm with another. > > > > > 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 > > > > > Debuggability > > As a change to the visual blur, there is no specific debugging support. > > > > > 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 > > > https://wpt.fyi/results/css/filter-effects?label=master&label=experimental&aligned&q=%2Fcss%2Ffilter-effects%2Fbackdrop-filter- > > > > > Flag name on chrome://flags > > chrome://flags/#backdrop-filter-mirror-edge > > > Finch feature name > > BackdropFilterMirrorEdgeMode > > > Requires code in //chrome? > > False > > > Tracking bug > > https://issues.chromium.org/u/1/issues/40040614 > > > Estimated milestones > > Shipping on desktop > > 129 > > DevTrial on desktop > > 127 > > Shipping on Android > > 129 > > DevTrial on Android > > 127 > > Shipping on WebView > > 129 > > > > > Anticipated spec changes > > *Open questions about a feature may be a source of future web compat or > interop issues. Please list open issues (e.g. links to known github issues > in the project for the feature specification) whose resolution may > introduce web compat/interop risk (e.g., changing to naming or structure of > the API in a non-backward-compatible way).* > > None > > > Link to entry on the Chrome Platform Status > > https://chromestatus.com/feature/5382638738341888?gate=6076747077648384 > > 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 blink-dev+unsubscr...@chromium.org. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJh39TOb6j0EbXZG%3DJ96GZ27jYfu-k_J9cjA0Osi_aTKgoe9yQ%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJh39TOb6j0EbXZG%3DJ96GZ27jYfu-k_J9cjA0Osi_aTKgoe9yQ%40mail.gmail.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 blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJh39TP9hwWjB1zk7oNqfpoytgULNo%3DS63CFR8hwPeNnbew17A%40mail.gmail.com.
