Bug 131586 – Keep secondary tile grid for zoomed-out scale

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Antti Koivisto]

Better zooming

[Antti Koivisto]

Created attachment 229217 [details]
patch

[Antti Koivisto]

<rdar://problem/16383851>

[Darin Adler]

Comment on attachment 229217 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=229217&action=review

> Source/WebCore/platform/graphics/ca/mac/TileController.mm:520
> +        count +=  m_zoomedOutTileGrid->numberOfUnparentedTiles();

extra space here after "+="

[Tim Horton]

Comment on attachment 229217 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=229217&action=review

> Source/WebCore/platform/graphics/ca/GraphicsLayerCA.cpp:2999
> +        if (m_isPageTiledBackingLayer)
> +            m_uncommittedChanges |= ChildrenChanged;

Do we need to do this always? Is it bad if we do?

[Antti Koivisto]

> Do we need to do this always? Is it bad if we do?

We don't but I don't think it ends up doing significant amount of actual work if nothing changes (it just re-adds the layers that are already there).

[Antti Koivisto]

https://trac.webkit.org/r167256

[Simon Fraser (smfr)]

Comment on attachment 229217 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=229217&action=review

>> Source/WebCore/platform/graphics/ca/GraphicsLayerCA.cpp:2999
>> +            m_uncommittedChanges |= ChildrenChanged;
> 
> Do we need to do this always? Is it bad if we do?

Yeah, I would prefer that we don't always do this. It will result in extra remote layer tree transaction thrash.

tiledBacking() should have a:
bool contentsScaleChangeRequiresSublayerUpdate(float) or something.

> Source/WebCore/platform/graphics/ca/mac/TileController.mm:135
> +    return tileGrid().scale() * m_deviceScaleFactor;

I hope the scale /= deviceScaleFactor; and this math don't result in floating-point rounding issues that cause us to compare the contentsScale as different somewhere.

> Source/WebCore/platform/graphics/ca/mac/TileGrid.h:-62
> -    typedef unsigned TileValidationPolicyFlags;

Why did you remove this? I prefer strongly typed bitfield types.

> Source/WebCore/platform/graphics/ca/mac/TileGrid.mm:340
> +void TileGrid::revalidateTiles(unsigned validationPolicy)

:(