Bug 44699 – [Gtk] Reduce the size of the shadow buffer in the paths using the clip region

• Component: WebKitGTK
• Status: RESOLVED FIXED

[Alejandro G. Castro]

Currently we are creating shadows using the complete size of the element in the page, we can use the clip information to reduce that size.

[Alejandro G. Castro]

Created attachment 65587 [details]
Proposed patch

[Martin Robinson]

Does this patch net any performance improvements on its own?

[Alejandro G. Castro]

(In reply to comment #2)
> Does this patch net any performance improvements on its own?

Yep, mostly when scrolling a webpage, we blur a rect as big as the scroll movement, and also for big pages we only blur the viewport part even if the page is bigger than that, for instance identi.ca.

[Martin Robinson]

Is it possible to make calculateShadowBufferDimensions a non-static method and to do this there? That way we could benefit from this improvement at all call sites.

[Alejandro G. Castro]

(In reply to comment #4)
> Is it possible to make calculateShadowBufferDimensions a non-static method and to do this there? That way we could benefit from this improvement at all call sites.

It is, I planned this patch just to make it the rects because they are the main issue nowadays. I'll review the patch.

[Kenneth Rohde Christiansen]

Comment on attachment 65587 [details]
Proposed patch

Seems like a good optimization.

Remember to add a dot at the end of comments.

[Martin Robinson]

Do you mind creating a static function that take a rectangle and intersects it with the current Cairo clip? It could be passed an optional minimumSize argument. I think we may want to use this optimization in other places later on.

IntRect intersectRectWithCurrentCairoClip(cairo_t*, IntRect, int minimumSize=0);

Thanks.

[Alejandro G. Castro]

Committing this patch after talking to martin we will leave the generalization for the contextshadow patch in the bug 45599.

[Alejandro G. Castro]

Landed r67402