1420284 - Animation throttled incorrectly

Status: RESOLVED DUPLICATE of bug 1419225

(Core :: DOM: Animation, defect)

Description

[Miko Mynttinen]

Attachment: testcase.zip

This is a regression from bug 1190721.

Attached is a reduced testcase from humblebundle.com that includes perspective transform and and translateY transform animation.

Expected results: the animation plays continuously
Actual results: the animation only plays when mouse is moved over the element

Backing out the changes from bug 1190721 fixes this.

This seems like it might be caused by nsIFrame::IsScrolledOutOfView() returning true when it should not.

Comment 2

[Matt Woodrow (:mattwoodrow)]

The bug (fixed in 1419225) was in TransformGfxRectToAncestor, where the computed rect was too big for our nsRect representation and we were clipping of the bottom/right edges to make it fit.

This affected retained display lists because the resulting (clipped) rectangle no longer intersected the visible rect, so we didn't build display items for the transformed content and it disappeared.

It affects nsIFrame::IsScrolledOutOfView() for the same reason, and we were throttling the animation thinking it wasn't visible.

Comment 3

[Hiroyuki Ikezoe (:hiro)]

Oh nice. Good to know.  Thank you for your explanation Matt!