SVG text with gradient fill is rendered very slow

shallawa · Said Abou-Hallawa · commit 19fb3bc3aa27 · 2025-01-13T00:59:36.000-08:00
https://bugs.webkit.org/show_bug.cgi?id=285799# rdar://73203473 Reviewed by Simon Fraser. Refactor applying the SVG gradient resource into two appliers: one for text (TextGradientClipper) and the other for PathOrShape (PathOrShapeGradientApplier). TextGradientClipper draws the text into a mask ImageBuffer. Then GraphicsContext is clipped to this ImageBuffer before the targetRect is filled with gradient. PathOrShapeGradientApplier fills or strokes the path (or the shape) with the gradient resource. Add the new text applier TextGradientCompositor which draws the text into a transparency layer with SourceIn. Then it fills the targetRect with the gradient into another transparency layer with SourceOver. Then these two layers are composited to GraphicsContext. TextGradientCompositor will be used for all cases except when rendering to a PDFDocument because PDF context does not support some CompositeOperation. In this case TextGradientClipper will be used to draw the text. * LayoutTests/imported/blink/svg/text/obb-paintserver.html: * LayoutTests/imported/mozilla/svg/text-scale-02.svg: * LayoutTests/imported/mozilla/svg/text/simple-fill-gradient.svg: * Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResource.cpp: (WebCore::LegacyRenderSVGResource::fillAndStrokePathOrShape): (WebCore::LegacyRenderSVGResource::fillAndStrokePathOrShape const): Deleted. * Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResource.h: * Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResourceGradient.cpp: (WebCore::LegacyRenderSVGResourceGradient::gradientDataForRenderer): (WebCore::applyGradientResource): (WebCore::PathOrShapeGradientApplier::applyResource): (WebCore::PathOrShapeGradientApplier::postApplyResource): (WebCore::calculateGradientGeometry): (WebCore::calculateGradientUserspaceTransform): (WebCore::TextGradientClipper::applyResource): (WebCore::TextGradientClipper::postApplyResource): (WebCore::TextGradientCompositor::applyResource): (WebCore::TextGradientCompositor::postApplyResource): (WebCore::LegacyRenderSVGResourceGradient::applyResource): (WebCore::LegacyRenderSVGResourceGradient::postApplyResource): (WebCore::createMaskAndSwapContextForTextGradient): Deleted. (WebCore::clipToTextMask): Deleted. * Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResourceGradient.h: Canonical link: https://commits.webkit.org/288788@main
diff --git a/LayoutTests/imported/blink/svg/text/obb-paintserver.html b/LayoutTests/imported/blink/svg/text/obb-paintserver.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<meta name="fuzzy" content="maxDifference=0-2; totalPixels=0-12500" />
+<meta name="fuzzy" content="maxDifference=0-2; totalPixels=0-13003" />
 <svg width="200" height="400">
   <linearGradient id="gradient" x1="0" x2="0" y1="0" y2="1">
     <stop offset="0" stop-color="green"/>
diff --git a/LayoutTests/imported/mozilla/svg/text-scale-02.svg b/LayoutTests/imported/mozilla/svg/text-scale-02.svg
@@ -3,7 +3,7 @@
      http://creativecommons.org/publicdomain/zero/1.0/
 -->
 <svg xmlns="http://www.w3.org/2000/svg">
-  <meta name="fuzzy" content="maxDifference=0-2;totalPixels=67000-105000" />
+  <meta name="fuzzy" content="maxDifference=0-2; totalPixels=67000-111217" />
   <style>
     @font-face {
       font-family: Ahem;
diff --git a/LayoutTests/imported/mozilla/svg/text/simple-fill-gradient.svg b/LayoutTests/imported/mozilla/svg/text/simple-fill-gradient.svg
@@ -3,7 +3,7 @@
      http://creativecommons.org/publicdomain/zero/1.0/
 -->
 <svg xmlns="http://www.w3.org/2000/svg" width="700" height="200" viewBox="0 0 700 200">
-  <meta name="fuzzy" content="maxDifference=0-2;totalPixels=120-135" />
+  <meta name="fuzzy" content="maxDifference=0-2;totalPixels=120-137" />
   <style>
     @font-face {
       font-family: Ahem;
diff --git a/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResource.cpp b/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResource.cpp
@@ -3,7 +3,7 @@
  * Copyright (C) 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
- * Copyright (C) 2023 Apple Inc. All rights reserved.
+ * Copyright (C) 2023-2025 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -264,7 +264,7 @@ void LegacyRenderSVGResource::markForLayoutAndParentResourceInvalidationIfNeeded
     }
 }
 
-void LegacyRenderSVGResource::fillAndStrokePathOrShape(GraphicsContext& context, OptionSet<RenderSVGResourceMode> resourceMode, const Path* path, const RenderElement* shape) const
+void LegacyRenderSVGResource::fillAndStrokePathOrShape(GraphicsContext& context, OptionSet<RenderSVGResourceMode> resourceMode, const Path* path, const RenderElement* shape)
 {
     if (shape) {
         ASSERT(shape->isRenderOrLegacyRenderSVGShape());
diff --git a/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResource.h b/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResource.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
+ * Copyright (C) 2025 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -83,8 +84,7 @@ class LegacyRenderSVGResource {
     static void markForLayoutAndParentResourceInvalidation(RenderObject&, bool needsLayout = true);
     static void markForLayoutAndParentResourceInvalidationIfNeeded(RenderObject&, bool needsLayout, SingleThreadWeakHashSet<RenderObject>* visitedRenderers);
 
-protected:
-    void fillAndStrokePathOrShape(GraphicsContext&, OptionSet<RenderSVGResourceMode>, const Path*, const RenderElement* shape) const;
+    static void fillAndStrokePathOrShape(GraphicsContext&, OptionSet<RenderSVGResourceMode>, const Path*, const RenderElement* shape);
 };
 
 constexpr bool resourceWasApplied(OptionSet<LegacyRenderSVGResource::ApplyResult> result)
diff --git a/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResourceGradient.cpp b/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResourceGradient.cpp
diff --git a/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResourceGradient.h b/Source/WebCore/rendering/svg/legacy/LegacyRenderSVGResourceGradient.h

Original file line number	Diff line number	Diff line change
`@@ -3,7 +3,7 @@`
`3`	`3`	`* Copyright (C) 2007 Rob Buis <[email protected]>`
`4`	`4`	`* Copyright (C) 2008 Dirk Schulze <[email protected]>`
`5`	`5`	`* Copyright (C) Research In Motion Limited 2010. All rights reserved.`
`6`		`- * Copyright (C) 2023 Apple Inc. All rights reserved.`
	`6`	`+ * Copyright (C) 2023-2025 Apple Inc. All rights reserved.`
`7`	`7`	`*`
`8`	`8`	`* This library is free software; you can redistribute it and/or`
`9`	`9`	`* modify it under the terms of the GNU Library General Public`
`@@ -264,7 +264,7 @@ void LegacyRenderSVGResource::markForLayoutAndParentResourceInvalidationIfNeeded`
`264`	`264`	`}`
`265`	`265`	`}`
`266`	`266`
`267`		`-void LegacyRenderSVGResource::fillAndStrokePathOrShape(GraphicsContext& context, OptionSet<RenderSVGResourceMode> resourceMode, const Path* path, const RenderElement* shape) const`
	`267`	`+void LegacyRenderSVGResource::fillAndStrokePathOrShape(GraphicsContext& context, OptionSet<RenderSVGResourceMode> resourceMode, const Path* path, const RenderElement* shape)`
`268`	`268`	`{`
`269`	`269`	`if (shape) {`
`270`	`270`	`ASSERT(shape->isRenderOrLegacyRenderSVGShape());`