1585240 - Add a composite code path for picture cache tiles.

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Comment 1

[Glenn Watson [:gw]]

Attachment: Bug 1585240 - Add a composite code path for picture cache tiles.

Previously, picture cache tiles were added to normal batches, and drawn
via the brush_image shader. Since all content is now in picture cache
tiles, we can instead draw the tiles via a separate code path. The tiles
for all picture caches are collected into a single composite config, that
is stored in the Frame structure. These two changes provide a number of
advantages:

• The composite shader is very simple - it doesn't need to deal with
  transforms, anti-aliasing, repetition etc.
• Since we create the tile batches in render(), rather than in the
  backend, we can take advantage of information not available until
  the render() call. For example, Gecko will provide information here
  when the partial presentation rects need to be reset. This will be
  used to enable partial presentation parameters on Windows.
• In future, we can access this list of tiles to be composited, and use
  them to configure the OS compositor integration, and hand the tiles
  directly to the OS compositor.
• In future, we can apply global optimizations to the set of picture
  cache tiles (e.g. occlude background tiles on CPU to skip paying
  the z-reject cost of drawing them).
• In future, we can take advantage of the simpler composite path
  for software rasterizer implementations.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/845c92fd34a6
Add a composite code path for picture cache tiles. r=kvark

Comment 4

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/845c92fd34a6

Comment 5

[Florin Strugariu [:Bebe]]

== Change summary for alert #23347 (as of Fri, 04 Oct 2019 06:17:17 GMT) ==

Improvements:

3% tp5o_scroll linux64-shippable-qr opt e10s stylo 2.32 -> 2.24
3% tp5o_scroll linux64-shippable-qr opt e10s stylo 2.32 -> 2.25
3% tscrollx linux64-shippable-qr opt e10s stylo 1.23 -> 1.20

For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=23347