948802 - Scrolling layer causes buffer re-allocation

Status: RESOLVED INVALID

(Core :: Graphics: Layers, defect)

Description

[Benoit Girard (:BenWa)]

Attachment: testcase.html

With this testcase and some logging on buffer re-allocation we see a lot of buffer reallocation for what should be a well performing scroll.

Comment 1

[Benoit Girard (:BenWa)]

Attachment: patch

This patch fixes the problem for me.

If we wanted we could instead add a way to force bounds on the buffer rather then increase the content bounds which causes over painting.

Comment 2

[Matt Woodrow (:mattwoodrow)]

Comment on attachment 8345697 [details] [diff] [review]
patch

Review of attachment 8345697 [details] [diff] [review]:
-----------------------------------------------------------------

I think roc should look at this, since I discussed it with you.

I think we at least need to limit the area to the part of the scroll frame that is visible. Intersecting with the viewport might be the easiest way to do this.

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 8345697 [details] [diff] [review]
patch

Review of attachment 8345697 [details] [diff] [review]:
-----------------------------------------------------------------

Yes, we do need to do something here. Intersect the rect with the scrollframe's cliprect maybe?

Comment 4

[Benoit Girard (:BenWa)]

This is still important but may be solved by tiling everywhere.

Comment 5

[Benoit Girard (:BenWa)]

This bug is obsolete.