Changeset 286846 in webkit

Timestamp:

Dec 10, 2021, 5:51:02 AM (5 years ago)

Author:

Nikolas Zimmermann

Message:

[LBSE] Create RenderSVGRoot renderer for outermost <svg> and allow direct <rect> children
​https://bugs.webkit.org/show_bug.cgi?id=233873

Reviewed by Rob Buis.

Construct RenderSVGRoot renderers for the outermost <svg> element when LBSE is enabled.
An 'allowlist' approach is used to only create renderers for those SVG elements that
are aware of LBSE: outermost <svg> element + <rect> element. For all other elements
no renderers will be created in LBSE for now.

This patch leaves the legacy engine unchanged (probed by EWS & local test runs),
and also LBSE shows no assertions/crashes/hangs in release/debug builds - tested
with "run-webkit-tests --internal-feature=LayerBasedSVGEngineEnabled".

Note that many layout tests will either timeout or show a different result,
due to the small capabilities of LBSE at present. Therefore it's beneficial to
decrease timeouts / use more workers when running layout tests. Otherwise they
will take a long time to complete. On my macOS Monterey M1 MacBook, following
parameters lead to a reasonable test execution time:

run-webkit-tests --internal-feature=LayerBasedSVGEngineEnabled --timeout=5000 \
--no-sample-on-timeout --no-retry-failures --child-processes=15 \
[--release / --debug] svg

Covered by existing tests.

• rendering/svg/RenderSVGModelObject.cpp:

(WebCore::RenderSVGModelObject::clippedOverflowRect const):
(WebCore::RenderSVGModelObject::nodeAtPoint):

• rendering/svg/RenderSVGModelObject.h:

(WebCore::RenderSVGModelObject::visualOverflowRectEquivalent const):

• svg/SVGElement.cpp:

(WebCore::createSVGLayerAwareElementSet):
(WebCore::isSVGLayerAwareElement):
(WebCore::SVGElement::childShouldCreateRenderer const):

• svg/SVGSVGElement.cpp:

(WebCore::SVGSVGElement::createElementRenderer):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/svg/RenderSVGModelObject.cpp (modified) (3 diffs)
• rendering/svg/RenderSVGModelObject.h (modified) (1 diff)
• svg/SVGElement.cpp (modified) (2 diffs)
• svg/SVGSVGElement.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-12-10  Nikolas Zimmermann  <nzimmermann@igalia.com>
+
+        [LBSE] Create RenderSVGRoot renderer for outermost <svg> and allow direct <rect> children
+        https://bugs.webkit.org/show_bug.cgi?id=233873
+
+        Reviewed by Rob Buis.
+
+        Construct RenderSVGRoot renderers for the outermost <svg> element when LBSE is enabled.
+        An 'allowlist' approach is used to only create renderers for those SVG elements that
+        are aware of LBSE: outermost <svg> element + <rect> element. For all other elements
+        no renderers will be created in LBSE for now.
+
+        This patch leaves the legacy engine unchanged (probed by EWS & local test runs),
+        and also LBSE shows no assertions/crashes/hangs in release/debug builds - tested
+        with "run-webkit-tests --internal-feature=LayerBasedSVGEngineEnabled".
+
+        Note that many layout tests will either timeout or show a different result,
+        due to the small capabilities of LBSE at present. Therefore it's beneficial to
+        decrease timeouts / use more workers when running layout tests. Otherwise they
+        will take a long time to complete. On my macOS Monterey M1 MacBook, following
+        parameters lead to a reasonable test execution time:
+
+        run-webkit-tests --internal-feature=LayerBasedSVGEngineEnabled --timeout=5000 \
+        --no-sample-on-timeout --no-retry-failures --child-processes=15 \
+        [--release / --debug] svg
+
+        Covered by existing tests.
+
+        * rendering/svg/RenderSVGModelObject.cpp:
+        (WebCore::RenderSVGModelObject::clippedOverflowRect const):
+        (WebCore::RenderSVGModelObject::nodeAtPoint):
+        * rendering/svg/RenderSVGModelObject.h:
+        (WebCore::RenderSVGModelObject::visualOverflowRectEquivalent const):
+        * svg/SVGElement.cpp:
+        (WebCore::createSVGLayerAwareElementSet):
+        (WebCore::isSVGLayerAwareElement):
+        (WebCore::SVGElement::childShouldCreateRenderer const):
+        * svg/SVGSVGElement.cpp:
+        (WebCore::SVGSVGElement::createElementRenderer):
+
 2021-12-10  Antti Koivisto  <antti@apple.com>
 

trunk/Source/WebCore/rendering/svg/RenderSVGModelObject.cpp

@@ -32 +32 @@
 #include "RenderSVGModelObject.h"
 
+#include "NotImplemented.h"
+#include "RenderLayer.h"
 #include "RenderLayerModelObject.h"
 #include "RenderSVGResource.h"
+#include "RenderView.h"
 #include "SVGElementInlines.h"
 #include "SVGNames.h"
@@ -49 +52 @@
 }
 
-LayoutRect RenderSVGModelObject::clippedOverflowRect(const RenderLayerModelObject* repaintContainer, VisibleRectContext) const
-{
+LayoutRect RenderSVGModelObject::clippedOverflowRect(const RenderLayerModelObject* repaintContainer, VisibleRectContext context) const
+{
+#if ENABLE(LAYER_BASED_SVG_ENGINE)
+    if (document().settings().layerBasedSVGEngineEnabled()) {
+        if (style().visibility() != Visibility::Visible && !enclosingLayer()->hasVisibleContent())
+            return LayoutRect();
+
+        ASSERT(!view().frameView().layoutContext().isPaintOffsetCacheEnabled());
+        return computeRect(visualOverflowRectEquivalent(), repaintContainer, context);
+    }
+#else
+    UNUSED_PARAM(context);
+#endif
+
     return SVGRenderSupport::clippedOverflowRectForRepaint(*this, repaintContainer);
 }
@@ -112 +127 @@
 bool RenderSVGModelObject::nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation&, const LayoutPoint&, HitTestAction)
 {
+#if ENABLE(LAYER_BASED_SVG_ENGINE)
+    if (document().settings().layerBasedSVGEngineEnabled()) {
+        // FIXME: [LBSE] Upstream RenderSVGModelObject inheritance changes (should inherit from RenderLayerModelObject).
+        notImplemented();
+        return false;
+    }
+#endif
+
     ASSERT_NOT_REACHED();
     return false;

trunk/Source/WebCore/rendering/svg/RenderSVGModelObject.h

@@ -63 +63 @@
     SVGElement& element() const { return downcast<SVGElement>(nodeForNonAnonymous()); }
 
+    // FIXME: [LBSE] Upstream SVGBoundingBoxComputation
+    // LayoutRect visualOverflowRectEquivalent() const { return SVGBoundingBoxComputation::computeVisualOverflowRect(*this); }
+    LayoutRect visualOverflowRectEquivalent() const { return LayoutRect(); }
+
 protected:
     RenderSVGModelObject(SVGElement&, RenderStyle&&);

trunk/Source/WebCore/svg/SVGElement.cpp

@@ -525 +525 @@
 }
 
+#if ENABLE(LAYER_BASED_SVG_ENGINE)
+static MemoryCompactLookupOnlyRobinHoodHashSet<AtomString> createSVGLayerAwareElementSet()
+{
+    // List of all SVG elements whose renderers support the layer aware layout / painting / hit-testing mode ('LBSE-mode').
+    using namespace SVGNames;
+    MemoryCompactLookupOnlyRobinHoodHashSet<AtomString> set;
+    for (auto& tag : { rectTag.get() })
+        set.add(tag.localName());
+    return set;
+}
+
+static inline bool isSVGLayerAwareElement(const SVGElement& element)
+{
+    static NeverDestroyed<MemoryCompactLookupOnlyRobinHoodHashSet<AtomString>> set = createSVGLayerAwareElementSet();
+    return set.get().contains(element.localName());
+}
+#endif
+
 bool SVGElement::childShouldCreateRenderer(const Node& child) const
 {
@@ -534 +552 @@
     // If the layer based SVG engine is enabled, all renderers that do not support the
     // RenderLayer aware layout / painting / hit-testing mode ('LBSE-mode') have to be skipped.
-    // Currently all renderers are skipped.
+    // FIXME: [LBSE] Upstream support for all elements, and remove 'isSVGLayerAwareElement' check afterwards.
     if (document().settings().layerBasedSVGEngineEnabled())
-        return false;
+        return isSVGLayerAwareElement(svgChild);
 #endif
 

trunk/Source/WebCore/svg/SVGSVGElement.cpp

@@ -399 +399 @@
 RenderPtr<RenderElement> SVGSVGElement::createElementRenderer(RenderStyle&& style, const RenderTreePosition&)
 {
-    if (isOutermostSVGSVGElement())
+    if (isOutermostSVGSVGElement()) {
+#if ENABLE(LAYER_BASED_SVG_ENGINE)
+        if (document().settings().layerBasedSVGEngineEnabled())
+            return createRenderer<RenderSVGRoot>(*this, WTFMove(style));
+#endif
         return createRenderer<LegacyRenderSVGRoot>(*this, WTFMove(style));
+    }
     return createRenderer<RenderSVGViewportContainer>(*this, WTFMove(style));
 }