Bug 102309 – Coordinated Graphics: A Minor optimization of calculating transforms in CoordinagedGraphicsLayer.

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Dongseong Hwang]

We calculate an inverse transform each tiledBackingStoreVisibleRect() call by a TiledBackingStore and every tiles.
This patch caches the inverse transform to reuse it.

[Dongseong Hwang]

Created attachment 174304 [details]
Patch

[Kenneth Rohde Christiansen]

Comment on attachment 174304 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=174304&action=review

> Source/WebKit2/ChangeLog:8
> +        We calculate an inverse transform each tiledBackingStoreVisibleRect() call by
> +        a TiledBackingStore and every tiles.
> +        This patch caches the inverse transform to reuse it.

anyway we can assert to make sure it is always updated before use?

[Dongseong Hwang]

Created attachment 174391 [details]
Patch

[Dongseong Hwang]

Comment on attachment 174304 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=174304&action=review

>> Source/WebKit2/ChangeLog:8
>> +        This patch caches the inverse transform to reuse it.
> 
> anyway we can assert to make sure it is always updated before use?

Thanks for review!

That's good idea! I'll update.

[Dongseong Hwang]

(In reply to comment #3)
> Created an attachment (id=174391) [details]
> Patch

Add ASSERT :)

[Kenneth Rohde Christiansen]

Comment on attachment 174391 [details]
Patch

Do you have any performance data? like how much of an improvement is it? We normally require that

[kov's GTK+ EWS bot]

Comment on attachment 174391 [details]
Patch

Attachment 174391 [details] did not pass gtk-ews (gtk):
Output: http://queues.webkit.org/results/14831845

[Dongseong Hwang]

(In reply to comment #6)
> (From update of attachment 174391 [details])
> Do you have any performance data? like how much of an improvement is it? We normally require that

Fortunately, I can get the data in my machine (Intel® Xeon(R) CPU X5650 @ 2.67GHz × 6).
In morphing cubes demo (https://www.webkit.org/blog-files/3d-transforms/morphing-cubes.html), when we push "toggle shape" button, CoordinatedGraphicsLayer::tiledBackingStoreVisibleRect() is called.

At the moment,
CoordinatedGraphicsLayer::flushCompositingStateForThisLayerOnly() takes 118ns.
CoordinatedGraphicsLayer::tiledBackingStoreVisibleRect() taske 65ns.
It means inverse transform takes 55% of times during whole CoordinatedGraphicsLayer::flushCompositingStateForThisLayerOnly() process.
Inverse transform is heavier than what I expected.

However, this patch does not improve morphing cubes demo's performance because all layers have just one tile.
If we have large layers with 3d transform animation, this patch increase performance fairly.

[Dongseong Hwang]

Created attachment 174548 [details]
Patch

[Dongseong Hwang]

patch due to flaky gtk ews fail.

[WebKit Review Bot]

Comment on attachment 174548 [details]
Patch

Clearing flags on attachment: 174548

Committed r134868: <http://trac.webkit.org/changeset/134868>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.

[Dongseong Hwang]

Thank Kenneth and noam for review! :)