[Filters] Do not clip the destination context when compositing the fi…

…lter style transparency layers https://bugs.webkit.org/show_bug.cgi?id=261926 rdar://115901634 Reviewed by Simon Fraser. Clipping is not needed at that time because it has to be applied to the filter style transparency layers before drawing the target element. If this unneeded clipping is applied, removing this clipping will overlap with ending the transparency layers. This will end up calling GraphicsContext::restore() with the wrong purpose. Rename FilterTargetSwitcher::needsRedrawSourceImage() to hasSourceImage() and flip its meaning. This will make differentiating software filters from style filters clearer. When hasSourceImage() is true, this means the target element is drawn to an ImageBuffer. * LayoutTests/css3/filters/drop-shadow-child-clipped-expected.html: Added. * LayoutTests/css3/filters/drop-shadow-child-clipped.html: Added. * LayoutTests/fast/filter-image/clipped-filter.html: * Source/WebCore/platform/graphics/filters/FilterImageTargetSwitcher.h: * Source/WebCore/platform/graphics/filters/FilterStyleTargetSwitcher.h: (): Deleted. * Source/WebCore/platform/graphics/filters/FilterTargetSwitcher.h: (WebCore::FilterTargetSwitcher::hasSourceImage const): (WebCore::FilterTargetSwitcher::needsRedrawSourceImage const): Deleted. * Source/WebCore/rendering/RenderLayer.cpp: (WebCore::RenderLayer::applyFilters): * Source/WebCore/rendering/RenderLayerFilters.cpp: (WebCore::RenderLayerFilters::hasSourceImage const): (WebCore::RenderLayerFilters::beginFilterEffect): (WebCore::RenderLayerFilters::needsRedrawSourceImage const): Deleted. * Source/WebCore/rendering/RenderLayerFilters.h: * Source/WebCore/rendering/svg/RenderSVGResourceFilter.cpp: (WebCore::RenderSVGResourceFilter::applyResource): Canonical link: https://commits.webkit.org/268341@main
WebKit · Sep 22, 2023 · a73cf05 · a73cf05
1 parent 4c8538a
commit a73cf05
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Showing 10 changed files with 73 additions and 19 deletions.
diff --git a/LayoutTests/css3/filters/drop-shadow-child-clipped-expected.html b/LayoutTests/css3/filters/drop-shadow-child-clipped-expected.html
@@ -0,0 +1,28 @@
+<style>
+    .container {
+        width: 135px;
+        height: 100px;
+        border: gray 1px solid;
+        overflow: hidden;                
+    }
+    .box {
+        width: 45px;
+        height: 100px;
+        position: relative;
+    }
+    .blue-background {
+        left: 0;
+        background: MediumBlue;
+    }
+    .red-background {
+        left: 90px;
+        top: -100px;
+        background: crimson;
+    }
+</style>
+<body>
+    <div class="container">
+        <div class="box blue-background"></div>
+        <div class="box red-background"></div>
+    </div>
+</body>
diff --git a/LayoutTests/css3/filters/drop-shadow-child-clipped.html b/LayoutTests/css3/filters/drop-shadow-child-clipped.html
@@ -0,0 +1,22 @@
+<!-- webkit-test-runner [ GraphicsContextFiltersEnabled=true ] -->
+<style>
+    .container {
+        width: 135px;
+        height: 100px;
+        border: gray 1px solid;
+        overflow: hidden;                
+    }
+    .box {
+        width: 45px;
+        height: 100px;
+        position: relative;
+        left: 90px;
+        background: crimson;
+        filter: drop-shadow(-90px 0 0 MediumBlue);
+    }
+</style>
+<body>
+    <div class="container">
+        <div class="box"></div>
+    </div>
+</body>
diff --git a/LayoutTests/fast/filter-image/clipped-filter.html b/LayoutTests/fast/filter-image/clipped-filter.html
@@ -46,7 +46,7 @@
 <svg>
     <defs>
         <clipPath id="clipPath">
-            <path d="M18,38 v200 h90 a150,150 0 0,1 300,0 h50 v-200 z"
+            <path d="M18,38 v200 h90 a150,150 0 0,1 300,0 h50 v-200 z">
         </clipPath>
     </defs>
 </svg>

diff --git a/Source/WebCore/platform/graphics/filters/FilterImageTargetSwitcher.h b/Source/WebCore/platform/graphics/filters/FilterImageTargetSwitcher.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2022 Apple Inc.  All rights reserved.
+ * Copyright (C) 2022-2023 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -39,6 +39,8 @@ class FilterImageTargetSwitcher final : public FilterTargetSwitcher {
 private:
     GraphicsContext* drawingContext(GraphicsContext& destinationContext) const override;
 
+    bool hasSourceImage() const override { return m_sourceImage; }
+
     void beginClipAndDrawSourceImage(GraphicsContext& destinationContext, const FloatRect& repaintRect) override;
     void endClipAndDrawSourceImage(GraphicsContext& destinationContext) override;
     void endDrawSourceImage(GraphicsContext& destinationContext) override;

diff --git a/Source/WebCore/platform/graphics/filters/FilterStyleTargetSwitcher.h b/Source/WebCore/platform/graphics/filters/FilterStyleTargetSwitcher.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2022 Apple Inc.  All rights reserved.
+ * Copyright (C) 2022-2023 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -36,8 +36,6 @@ class FilterStyleTargetSwitcher : public FilterTargetSwitcher {
     FilterStyleTargetSwitcher(Filter&, const FloatRect &sourceImageRect);
 
 private:
-    bool needsRedrawSourceImage() const override { return true; }
-
     void beginDrawSourceImage(GraphicsContext& destinationContext) override;
     void endDrawSourceImage(GraphicsContext& destinationContext) override;
 

diff --git a/Source/WebCore/platform/graphics/filters/FilterTargetSwitcher.h b/Source/WebCore/platform/graphics/filters/FilterTargetSwitcher.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2022 Apple Inc.  All rights reserved.
+ * Copyright (C) 2022-2023 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -44,7 +44,7 @@ class FilterTargetSwitcher {
 
     virtual GraphicsContext* drawingContext(GraphicsContext& destinationContext) const { return &destinationContext; }
 
-    virtual bool needsRedrawSourceImage() const { return false; }
+    virtual bool hasSourceImage() const { return false; }
 
     virtual void beginClipAndDrawSourceImage(GraphicsContext& destinationContext, const FloatRect&) { beginDrawSourceImage(destinationContext); }
     virtual void endClipAndDrawSourceImage(GraphicsContext& destinationContext) { endDrawSourceImage(destinationContext); }

diff --git a/Source/WebCore/rendering/RenderLayer.cpp b/Source/WebCore/rendering/RenderLayer.cpp
@@ -3162,13 +3162,18 @@ GraphicsContext* RenderLayer::setupFilters(GraphicsContext& destinationContext,
 
 void RenderLayer::applyFilters(GraphicsContext& originalContext, const LayerPaintingInfo& paintingInfo, OptionSet<PaintBehavior> behavior, const LayerFragments& layerFragments)
 {
-    // FIXME: Handle more than one fragment.
-    ClipRect backgroundRect = layerFragments.isEmpty() ? ClipRect() : layerFragments[0].backgroundRect;
-
     GraphicsContextStateSaver stateSaver(originalContext, false);
-    RegionContextStateSaver regionContextStateSaver(paintingInfo.regionContext);
+    bool needsClipping = m_filters->hasSourceImage();
+
+    if (needsClipping) {
+        // FIXME: Handle more than one fragment.
+        ClipRect backgroundRect = layerFragments.isEmpty() ? ClipRect() : layerFragments[0].backgroundRect;
+
+        RegionContextStateSaver regionContextStateSaver(paintingInfo.regionContext);
+
+        clipToRect(originalContext, stateSaver, regionContextStateSaver, paintingInfo, behavior, backgroundRect);
+    }
 
-    clipToRect(originalContext, stateSaver, regionContextStateSaver, paintingInfo, behavior, backgroundRect);
     m_filters->applyFilterEffect(originalContext);
 }
 

diff --git a/Source/WebCore/rendering/RenderLayerFilters.cpp b/Source/WebCore/rendering/RenderLayerFilters.cpp
@@ -62,9 +62,9 @@ bool RenderLayerFilters::hasFilterThatShouldBeRestrictedBySecurityOrigin() const
     return m_filter && m_filter->hasFilterThatShouldBeRestrictedBySecurityOrigin();
 }
 
-bool RenderLayerFilters::needsRedrawSourceImage() const
+bool RenderLayerFilters::hasSourceImage() const
 {
-    return m_targetSwitcher && m_targetSwitcher->needsRedrawSourceImage();
+    return m_targetSwitcher && m_targetSwitcher->hasSourceImage();
 }
 
 void RenderLayerFilters::notifyFinished(CachedResource&, const NetworkLoadMetrics&)
@@ -178,7 +178,7 @@ GraphicsContext* RenderLayerFilters::beginFilterEffect(RenderElement& renderer,
 
     if (!filter.hasFilterThatMovesPixels())
         m_repaintRect = dirtyRect;
-    else if (hasUpdatedBackingStore || needsRedrawSourceImage())
+    else if (hasUpdatedBackingStore || !hasSourceImage())
         m_repaintRect = filterRegion;
     else {
         m_repaintRect = dirtyRect;

diff --git a/Source/WebCore/rendering/RenderLayerFilters.h b/Source/WebCore/rendering/RenderLayerFilters.h
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
- * Copyright (C) 2013-2022 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2023 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -56,6 +56,7 @@ class RenderLayerFilters final : private CachedSVGDocumentClient {
 
     bool hasFilterThatMovesPixels() const;
     bool hasFilterThatShouldBeRestrictedBySecurityOrigin() const;
+    bool hasSourceImage() const;
 
     void updateReferenceFilterClients(const FilterOperations&);
     void removeReferenceFilterClients();
@@ -73,8 +74,6 @@ class RenderLayerFilters final : private CachedSVGDocumentClient {
     void applyFilterEffect(GraphicsContext& destinationContext);
 
 private:
-    bool needsRedrawSourceImage() const;
-
     void notifyFinished(CachedResource&, const NetworkLoadMetrics&) final;
     void resetDirtySourceRect() { m_dirtySourceRect = LayoutRect(); }
 

diff --git a/Source/WebCore/rendering/svg/RenderSVGResourceFilter.cpp b/Source/WebCore/rendering/svg/RenderSVGResourceFilter.cpp
@@ -94,7 +94,7 @@ bool RenderSVGResourceFilter::applyResource(RenderElement& renderer, const Rende
         }
 
         ASSERT(filterData->targetSwitcher);
-        if (!filterData->targetSwitcher->needsRedrawSourceImage())
+        if (filterData->targetSwitcher->hasSourceImage())
             return false;
 
         filterData->targetSwitcher->beginDrawSourceImage(*context);