[GPU Process] [Filters 17/23] Make FilterEffect calculate the primitive subregion only when needed

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Said Abou-Hallawa]

FilterEffect should be able to calculate and hold only two rectangles:

1) primitiveSubRegion which is defined here https://www.w3.org/TR/filter-effects-1/#FilterPrimitiveSubRegion
2) imageRect which is the rectangle of the result FilterImage.

And to simplify the calculation we can keep these two rectangles as FloatRects and they will be in filter coordinates. But

1) Only when drawing to a FilterImage, we should convert from filter coordinates to absolute coordinates. 
2) And when getting pixels from or putting pixels in a FilterImage, we will convert the FloatRect to a IntRect.

And since the plan is to remove the result FilterImage from the FilterEffect, we are going to keep these rectangles in FilterImage. The conversion from filter coordinates to absolute coordinates will happen through the Filter class.

[Said Abou-Hallawa]

Created attachment 443290 [details]
Patch

[Said Abou-Hallawa]

Created attachment 443503 [details]
Patch

[Said Abou-Hallawa]

Created attachment 443504 [details]
Patch

[Said Abou-Hallawa]

Created attachment 443505 [details]
Patch

[Said Abou-Hallawa]

Created attachment 443516 [details]
Patch

[Said Abou-Hallawa]

Created attachment 443517 [details]
Patch

[Said Abou-Hallawa]

Created attachment 443652 [details]
Patch for review

[Radar WebKit Bug Importer]

<rdar://problem/85290142>

[Said Abou-Hallawa]

Created attachment 445965 [details]
Patch

[Said Abou-Hallawa]

Created attachment 446055 [details]
Patch

[Said Abou-Hallawa]

Created attachment 446057 [details]
Patch

[Said Abou-Hallawa]

Created attachment 446074 [details]
Patch

[Cameron McCormack (:heycam)]

Comment on attachment 446074 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=446074&action=review

> Source/WebCore/platform/graphics/filters/FilterEffect.cpp:52
> +        for (auto& input : inputs)
> +            primitiveSubregion.unite(input->primitiveSubregion());

I guess we're guaranteed that input's primitive subregion has already been calculated at this point, because of the ordering of the filter effects in the overall expression?

[Said Abou-Hallawa]

Comment on attachment 446074 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=446074&action=review

>> Source/WebCore/platform/graphics/filters/FilterEffect.cpp:52
>> +            primitiveSubregion.unite(input->primitiveSubregion());
> 
> I guess we're guaranteed that input's primitive subregion has already been calculated at this point, because of the ordering of the filter effects in the overall expression?

Yes this correct. In SVGFilter we apply the effects from the SVGFilterExpression which is the post-fix notation of the filter. For CSSFilter we apply the effects from left to right since every effect is the input to the next effect.

[EWS]

Committed r286578 (?): <https://commits.webkit.org/r286578>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 446074 [details].