Bug 254062 – [Filters] Calculating the CSSFilter geometry and clipping sometimes is incorrect

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Said Abou-Hallawa]

Like SVGFilter, CSSFilter should always intersect the FilterEffect imageRect with its primitiveSubregion. This will require:

1. Filter::ClipOperation will be removed.
2. Filter::clipToMaxEffectRect() will always clip the rectangle with maxEffectRect.
3. FilterEffect::calculateImageRect() will return the maxEffectRect if number of input effects is zero. This was a bug which was covered by the union mode of Filter::clipToMaxEffectRect().
4. RenderLayerFilters::beginFilterEffect() should set its targetBoundingBox the sourceImageRect of FilterTargetSwitcher.
5. SVGFilterGraph::getNamedNodes() should not return an error if one of the inputs is builtin and there is no node for it. This happens when we build a graph of primitives and one of the inputs is SourceGraphic or SourceAlpha. In this case we just need to ignore this input since there is no built-in primitive for it. This fixes the calculation of the filter outsets which was covered by  the union mode of Filter::clipToMaxEffectRect().

[Said Abou-Hallawa]

Created attachment 465472 [details]
test case (does not work on Retina display)

[Said Abou-Hallawa]

Created attachment 465473 [details]
test case 2 (incorrect filter geometry)

[Radar WebKit Bug Importer]

<rdar://problem/106844401>

[Said Abou-Hallawa]

Pull request: https://github.com/WebKit/WebKit/pull/11641

[Said Abou-Hallawa]

Created attachment 465481 [details]
test case 3 (unclipped filter region)

[EWS]

Committed 261827@main (7acdd2650a9b): <https://commits.webkit.org/261827@main>

Reviewed commits have been landed. Closing PR #11641 and removing active labels.