782332 - Retained tiles should not be used with fixed-position layers

Status: RESOLVED FIXED

(Core :: Graphics: Layers, defect)

Description

[Chris Lord [:cwiiis]]

Fixed position layers don't move, so it doesn't make sense to try to retain tiles. Currently, it just ends up causing weird-looking rendering glitches. We should just not use them for fixed position layers.

Eventually retained tiles will be superseded by on-demand tile rendering work, but this is an easy thing to do that will improve the experience on sites with top/bottom bars, etc.

Comment 1

[Chris Lord [:cwiiis]]

Attachment: Don't retain tiles on fixed position layers

Comment 2

[Benoit Girard (:BenWa)]

Comment on attachment 651516 [details] [diff] [review]
Don't retain tiles on fixed position layers

r+, nice detailed comment.

Comment 3

[Chris Lord [:cwiiis]]

Pushed to inbound:

https://hg.mozilla.org/integration/mozilla-inbound/rev/84f253d1174c

Comment 4

[Chris Lord [:cwiiis]]

Comment on attachment 651516 [details] [diff] [review]
Don't retain tiles on fixed position layers

[Approval Request Comment]
Bug caused by (feature/regressing bug #): Rendering artifacts when panning/zooming on pages with fixed-position elements
User impact if declined: See above
Testing completed (on m-c, etc.): Tested locally
Risk to taking this patch (and alternatives if risky): Low - just disables a feature in a simple and reliable way.
String or UUID changes made by this patch: None

Comment 5

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/84f253d1174c

Comment 6

[Chris Lord [:cwiiis]]

Pushed to aurora: http://hg.mozilla.org/releases/mozilla-aurora/rev/bb764cfc347a