Bug 76886 – [WK2][Qt] REGRESSION: Pages with transform animations sometimes omit some of the layers since r105413

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Noam Rosenthal]

This is a regression since we're calculating the layers' visible rects based on their transform, while ignoring that the transform might change while animating.

[Noam Rosenthal]

Created attachment 123669 [details]
Patch

[Noam Rosenthal]

Created attachment 123670 [details]
Patch

[WebKit Review Bot]

Attachment 123669 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebKit2/ChangeLog', u'Source/WebKit..." exit_code: 1

Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.h:38:  wtf includes should be <wtf/file.h> instead of "wtf/file.h".  [build/include] [4]
Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.h:38:  Alphabetical sorting problem.  [build/include_order] [4]
Total errors found: 2 in 3 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Noam Rosenthal]

Created attachment 124012 [details]
Patch

[Kenneth Rohde Christiansen]

Comment on attachment 124012 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=124012&action=review

Seems ok to me

> Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.cpp:551
> +    // If this layer is part of an active transform animation, the visible rect might change, so we rather render the whole layer
> +    // until some better optimization is available.

I would break the line after the second ,. Then they will have almost the same size

> Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.cpp:553
> +    if (selfOrAncestorHasActiveTransformAnimations())
> +        return tiledBackingStoreContentsRect();

Did you do some measurements of this? regarding to the comment in the changelog

> Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.cpp:725
> +    if (!parent())
> +        return false;
> +    return toWebGraphicsLayer(parent())->selfOrAncestorHasActiveTransformAnimations();

wouldnt it read nicer

if (parent())
    return toWeb....parent()...

return false;

[Noam Rosenthal]

> > Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.cpp:553
> > +    if (selfOrAncestorHasActiveTransformAnimations())
> > +        return tiledBackingStoreContentsRect();
> 
> Did you do some measurements of this? regarding to the comment in the changelog
No... if I had a viable alternative I'd measure it vs. this solution :) Problem is that if I'd calculate the visible rect based on all the transform keyframes, I could still reach a point where a huge layer is entirely visible. What we should probably do in that case is not have content-scale for huge transformed layers, but that should come later as it's tricky.

[Noam Rosenthal]

Created attachment 124015 [details]
Patch

[Noam Rosenthal]

Created attachment 124017 [details]
Patch

[WebKit Review Bot]

Comment on attachment 124017 [details]
Patch

Clearing flags on attachment: 124017

Committed r105934: <http://trac.webkit.org/changeset/105934>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.