Several members of the team attended TPAC to make progress on key specifications. We did pre-planning ensuring key issues are filed and discussed with the right people. Full trip-report is here but some highlights from TPAC are:
Agreements on deferring some small features (1, 2, 3) to web animations level 2 paving the path for shipping level 1.
Moving ScrollTimeline out of incubation with agreements on remaining key issues.
Progress on issues related to Group Effect and Matrix transforms.
Kevin ([email protected]) learned a lot about WPT and how we can use it more effectively which he shared with the team.
All of these were a result of constructive discussions with collaborators from Microsoft, Mozilla and Apple.
Scroll Timeline Polyfilled
As part of TPAC preparation Majid ([email protected]) proposed element-based targeting for ScrollTimeline. Rob ([email protected]) wrote a full fidelity polyfill for ScrollTimeline which implements the proposal. He used the polyfill to create a compelling demo of key usecases. The demo clearly shows the improved ergonomics which greatly helped in convincing CSSWG on merits of the proposal. It also helped us validate the proposal and find several awkward parts of the current API ?.
Excellent Scroll Snap
We continue to invest in making scroll snapping excellent. Kaan ([email protected]) has made sure more wpt test pass in chrome ,  and pay some technical debts while Majid worked on improving wheel scroll snapping . We also triaged and prioritized our bugs around interop after discussions with other browser vendors.?
"If the intersection between weird and usable is your thing, you’ll feel right at home with paint worklets!"?
This is a quote from the Paint Worklet presentation in CSSConf Budapest which comes with some neat demos. All the demos works flawlessly off the main thread (with --enable-blink-features=OffMainThreadCSSPaint). This sprint Xida ([email protected]) ensured Off-thread Paint Worklet has a launch plan as we get very close on enabling it on ToT. He also landed metrics and fixed multiple crashes .
Viz-HitTesting launched 1% on Stable
This sprint Viz hit-testing V2? was launched 1% on Stable for non-CrOS. This was a boring launch thanks to many bug-fixes landed beforehand. On Windows it shows that we are 32% better than the existing behavior on how many hit tests are handled synchronously.
The performance on CrOS in 78 beta is fascinating. 96% hit tests are synchronous. \o/
Code Health and Interop
Stephen ([email protected]) worked on improving web interoperability and compatibility by shipping ontransition event handlers. He spent time understanding webkit-prefixed versions usage and devised a? plan for removal or standardization (whatwg, code). George ([email protected]) improved css transitions specification and added new and cleaned up existing relevant tests , . Yi ([email protected]) removed special compositing logic for ScrollTimeline making it simpler and more general.
Sadly our amazing Stephen ([email protected]) is leaving the Animations team to join Ecosystem infrastructure team. While we are sad to see him leaving our team, we are happy that his passion, skills and leadership are going to have a large impact on the Web making it more interoperable. To ensure a smooth transition we have marked all bugs assigned to him as Hotlist-Interop ;). On the good news front, we have a new intern Kaan ([email protected]) who is going to make Scroll Snapping more excellent, and noogler Haozhe ([email protected]) joining the team.