1634616 - Expand partial prerender ares as much as possible for cases where the tranformed rect is outside of the overflow area

Status: RESOLVED FIXED

(Core :: Graphics: Layers, enhancement, P3)

Description

[Hiroyuki Ikezoe (:hiro)]

Attachment: t.html

Attaching file has a transform animation "translateX(100%) -> translateX(0%)" on a large element (width: 200%, height: 100%). On the initial frame of the animation, the transformed rect is completely outside of the viewport, so it's collapsed in nsDisplayTransform::UntransformRect, thus when this transform animation runs on the compositor, we don't use the partial prerender size limit effectively.

I am going to attach the recording what happens with enabling layout.animation.prerender.partial.

Comment 1

[Hiroyuki Ikezoe (:hiro)]

Attachment: The recording

The bottom window is the latest nightly, you can see white area at the right of the animating element.
The top window is a local build with fixing this issue.

Comment 2

[Hiroyuki Ikezoe (:hiro)]

Attachment: Bug 1634616 - Use un-transformed dirty rect to compute partial prerender area. r?botond

Comment 3

[Hiroyuki Ikezoe (:hiro)]

Attachment: An example involving a scale animation (scale(0.5) -> scale(1))

Comment 4

[Hiroyuki Ikezoe (:hiro)]

Attachment: Another example involving a scale animation (scale(2) -> scale(1))

Comment 5

[Hiroyuki Ikezoe (:hiro)]

Attachment: Yet another example involving scale animation (scale(0.5) -> scale(0.25))

Comment 6

[Hiroyuki Ikezoe (:hiro)]

Attachment: Bug 1634616 - Unscale pre-render area for transform animations too. r?botond

Comment 7

[Hiroyuki Ikezoe (:hiro)]

Attachment: Bug 1634616 - Calculate a perfect square based on the viewport size and rotate it to adjust the partial prerender area for rotation transforms. r?botond

This change will bring better results for continuous rotate animations.
For discontinuous rotate animations such as animations with step timing
functions this change might not bring better results but such kinds of
animations look originally janky, so it wouldn't be a problem at all.

Depends on D73404

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4279b1647e47
Unscale pre-render area for transform animations too. r=botond
https://hg.mozilla.org/integration/autoland/rev/60271de42eb8
Use un-transformed dirty rect to compute partial prerender area. r=botond
https://hg.mozilla.org/integration/autoland/rev/53da1ae188f4
Calculate a perfect square based on the viewport size and rotate it to adjust the partial prerender area for rotation transforms. r=botond

Comment 9

[Cristina Coroiu [:ccoroiu]]

Backed out 3 changesets (bug 1634616) for reftest failures at layout/reftests/transform/partial-prerender-expansion-rotate.html

Backout: https://hg.mozilla.org/integration/autoland/rev/ed1f0ce7f1cab2a4c004d6a24886a6b11b5df9e9

Failure push: https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=53da1ae188f45a78d759445b2d6eaab9fe4d4919

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=301874386&repo=autoland&lineNumber=30531

Comment 10

[Hiroyuki Ikezoe (:hiro)]

Looks like there appeared boundaries' lines of TiledLayer... I think it's a pre-existing issue. I am going to skip the reftest on Windows7.

Comment 11

[Timothy Nikkel (:tnikkel)]

What about just adding some fuzz for Windows 7 only? The rendering is pretty close.

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ca2b5b79e488
Unscale pre-render area for transform animations too. r=botond
https://hg.mozilla.org/integration/autoland/rev/f17da81e3e57
Use un-transformed dirty rect to compute partial prerender area. r=botond
https://hg.mozilla.org/integration/autoland/rev/1256cc14812b
Calculate a perfect square based on the viewport size and rotate it to adjust the partial prerender area for rotation transforms. r=botond

Comment 13

[Hiroyuki Ikezoe (:hiro)]

(In reply to Timothy Nikkel (:tnikkel) from comment #11)

What about just adding some fuzz for Windows 7 only? The rendering is pretty close.

Huh, I missed your comment. Yeah, adding fuzzy value is an idea. I will try to reproduce the failure locally on Linux, and hope to find the failure reason (IIRC there is a preference value related to this kind of TiledLayer boundary case). Once I couldn't find the reason I will consider using fuzzy there. Anyway I will file a bug for this.

Comment 14

[Hiroyuki Ikezoe (:hiro)]

Filed bug 1637432.

Comment 15

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/ca2b5b79e488
https://hg.mozilla.org/mozilla-central/rev/f17da81e3e57
https://hg.mozilla.org/mozilla-central/rev/1256cc14812b