1580063 - Track dirty rects in WR picture cache tiles, and use them to reduce GPU work.

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Comment 1

[Glenn Watson [:gw]]

Attachment: Bug 1580063 - Track dirty rects in WR picture cache tiles, and use them to reduce GPU work.

This patch adds a simple quadtree structure to each picture cache
tile. This tree is used to track dirty regions of each tile. By
using a tree that can split / merge nodes, the CPU overhead of
tracking dirty areas is minimized, by only splitting nodes where
content is regularly changing.

For now, this patch makes use of the dirty rects to set a single
scissor rect when rendering picture cache tiles. This results in
a significant performance improvement (due to fewer pixels being
drawn) on many pages. In future, the dirty rects will also be
exposed at the API level, allowing clients to leverage partial
present APIs for power saving purposes.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a1da279eb08b
Track dirty rects in WR picture cache tiles, and use them to reduce GPU work. r=nical

Comment 3

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/a1da279eb08b