Bug 140331 – Filters aren't applied to elements in columns after the first

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Simon Fraser (smfr)]

Issue with filters and columns.

[Simon Fraser (smfr)]

Created attachment 244402 [details]
Testcase

[Simon Fraser (smfr)]

rdar://problem/19313858

[Simon Fraser (smfr)]

The rootRelativeBounds computed by RenderLayer::setupFilters() doesn't take columns into account.

[Simon Fraser (smfr)]

clip-path is similarly broken.

[Simon Fraser (smfr)]

Fix is something like this:

diff --git a/Source/WebCore/rendering/RenderLayer.cpp b/Source/WebCore/rendering/RenderLayer.cpp
index 1e9f4955775fa120f39cca40126296089e043746..8688273887be2d6dba3d741afe925a02071de05b 100644
--- a/Source/WebCore/rendering/RenderLayer.cpp
+++ b/Source/WebCore/rendering/RenderLayer.cpp
@@ -4094,12 +4094,14 @@ void RenderLayer::paintLayerContents(GraphicsContext* context, const LayerPainti
     bool needToAdjustSubpixelQuantization = setupFontSubpixelQuantization(context, didQuantizeFonts);
 
     // Apply clip-path to context.
-    bool hasClipPath = setupClipPath(context, paintingInfo, offsetFromRoot, rootRelativeBounds, rootRelativeBoundsComputed);
+    LayoutSize columnAwareOffsetFromRoot = toLayoutSize(convertToLayerCoords(paintingInfo.rootLayer, LayoutPoint(), AdjustForColumns));
+    bool hasClipPath = setupClipPath(context, paintingInfo, columnAwareOffsetFromRoot, rootRelativeBounds, rootRelativeBoundsComputed);
 
     LayerPaintingInfo localPaintingInfo(paintingInfo);
 
     GraphicsContext* transparencyLayerContext = context;
-    std::unique_ptr<FilterEffectRendererHelper> filterPainter = setupFilters(context, localPaintingInfo, paintFlags, offsetFromRoot, rootRelativeBounds, rootRelativeBoundsComputed);
+
+    std::unique_ptr<FilterEffectRendererHelper> filterPainter = setupFilters(context, localPaintingInfo, paintFlags, columnAwareOffsetFromRoot, rootRelativeBounds, rootRelativeBoundsComputed);
     if (filterPainter) {
         context = filterPainter->filterContext();
         if (context != transparencyLayerContext && haveTransparency) {

[Dean Jackson]

Created attachment 244539 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 244539 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=244539&action=review

> Source/WebCore/rendering/RenderLayer.cpp:4110
> +    if (renderer().flowThreadContainingBlock() && (renderer().hasClipPath() || hasFilterThatIsPainting(context, paintFlags)))

Is the renderer().flowThreadContainingBlock() permissive enough to handle blocks deeply nested inside columns?

[Dean Jackson]

Comment on attachment 244539 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=244539&action=review

>> Source/WebCore/rendering/RenderLayer.cpp:4110
>> +    if (renderer().flowThreadContainingBlock() && (renderer().hasClipPath() || hasFilterThatIsPainting(context, paintFlags)))
> 
> Is the renderer().flowThreadContainingBlock() permissive enough to handle blocks deeply nested inside columns?

I believe so.

[Dean Jackson]

Committed r178380: <http://trac.webkit.org/changeset/178380>