987005 - Add comments to the condition in PopThebesLayerData() that decides whether we want to optimize a thebes layer to an image or color layer

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Markus Stange [:mstange]]

Attachment: document-optimization-to-color-or-image-layer

The condition

> if (isRetained && (data->mIsSolidColorInVisibleRegion || imageContainer) &&
>     (data->mLayer->GetValidRegion().IsEmpty() || mLayerBuilder->CheckInLayerTreeCompressionMode())) {

completely went over my head when I read it the first time, and I had to do some extended bugzilla archeology in order to understand it completely. Some comments would be very helpful. This patch adds them.

Comment 1

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

Comment on attachment 8395505 [details] [diff] [review]
document-optimization-to-color-or-image-layer

Review of attachment 8395505 [details] [diff] [review]:
-----------------------------------------------------------------

::: layout/base/FrameLayerBuilder.cpp
@@ +1896,5 @@
>    nsRefPtr<Layer> layer;
>    nsRefPtr<ImageContainer> imageContainer = data->CanOptimizeImageLayer(mBuilder);
>  
> +  if ((aData->mIsSolidColorInVisibleRegion || imageContainer) &&
> +      ShouldOptimizeAwayThebesLayer(data, mLayerBuilder)) {

Name it "CanOptimizeAwayThebesLayer"

Comment 2

[Markus Stange [:mstange]]

Attachment: v2

Comment 3

[Markus Stange [:mstange]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/94df6fc66986

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/94df6fc66986