WebRender work is coming along nicely. I haven’t managed to properly track what landed this week so the summary below is somewhat short. This does little justice to the great stuff that is happening on the side. For example I won’t list the many bugs that Sotaro finds and fixes on a daily basis, or the continuous efforts Kats puts into keeping Gecko’s repository in sync with WebRender’s, or Ryan’s work on cbindgen (the tool we made to auto-generate C bindings for WebRender), or the unglamorous refactoring I got myself into in order to get some parts of Gecko to integrate with WebRender without breaking the web. Lee has been working on the dirty and gory details of fonts for a while but that won’t make it to the newsletter until it lands. Morris’s work on display items conversion hasn’t yet received due credit here, nor Jerry’s work on handling the many (way too many) texture formats that have to be supported by WebRender for video playback. Meanwhile Gankro is working on changes to the rust language itself that will make our life easier when dealing with fallible allocation and Kvark, after reviewing most of what lands in the WebRender repo and triaging all of the issues, manages to find the time to add tools to measure pixel coverage of render passes, and plenty of other things I don’t even know about because following everything closely would be a full-time job. You get the idea. I just wanted to give a little shout out to the people working on very important parts of the project that may not always appear in the highlights below, either because the work hasn’t landed yet, because I missed it, or because it was hidden behind Glenn’s usual round of epic optimization.

Notable WebRender changes

Glenn optimized the allocation of clip masks. Improvements with this fix on a test case generated from running cnn.com in Gecko:

GPU time 10ms -> 1.7ms. Clip target allocations 54 -> 1. CPU compositor time 2.8ms -> 1.8ms. CPU backend time 1.8ms -> 1.6ms.

Notable Gecko changes

Jeff landed tiling support for blob images. Tiling is currently only used for very large images, but when used we get parallel rasterization across tiles for free.

Fallback blob images are no longer manually clipped. This means that we don’t have to redraw them while scrolling anymore. This gives a large performance improvement when scrolling mozilla.org