Changeset 294902 in webkit for trunk/Source/WebCore/rendering/RenderObject.cpp

Timestamp:

May 26, 2022, 3:22:08 PM (3 years ago)

Author:

Alan Bujtas

Message:

Do not issue repaint when the ancestor layer has already been scheduled for one
​https://bugs.webkit.org/show_bug.cgi?id=240728

Reviewed by Simon Fraser.

When a renderer needs repaint, we walk the layer tree to search for the repaint container (root for all the paints).
If we find a layer between the renderer and the repaint container that has already been scheduled for a full repaint
we know that this repaint is redundant and will be covered by the ancestor layer.
Since layers paint their overflow content, this works even when the renderer "sticks out" of the ancestor layer's renderer's border box (i.e. produces ink/scrollable overflow).

• Source/WebCore/rendering/RenderLayer.cpp:

(WebCore::RenderLayer::enclosingCompositingLayerForRepaint const):
(WebCore::RenderLayer::clipCrossesPaintingBoundary const):
(WebCore::RenderLayer::calculateClipRects const):

• Source/WebCore/rendering/RenderLayer.h:

(WebCore::RenderLayer::needsFullRepaint const):

• Source/WebCore/rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::repaintInCompositedAncestor):

• Source/WebCore/rendering/RenderObject.cpp:

(WebCore::RenderObject::containerForRepaint const):
(WebCore::fullRepaintIsScheduled): This covers the cases when the content is embedded inside an iframe and the iframe's view is not composited.
(WebCore::RenderObject::repaint const):
(WebCore::RenderObject::repaintRectangle const):

• Source/WebCore/rendering/RenderView.cpp:

(WebCore::RenderView::paintBoxDecorations):

Canonical link: ​https://commits.webkit.org/251025@main

File:

• trunk/Source/WebCore/rendering/RenderObject.cpp (modified) (5 diffs)

trunk/Source/WebCore/rendering/RenderObject.cpp

@@ -861 +861 @@
 {
     RenderLayerModelObject* repaintContainer = nullptr;
+    auto fullRepaintAlreadyScheduled = false;
 
     if (view().usesCompositing()) {
-        if (RenderLayer* parentLayer = enclosingLayer()) {
-            RenderLayer* compLayer = parentLayer->enclosingCompositingLayerForRepaint();
-            if (compLayer)
-                repaintContainer = &compLayer->renderer();
+        if (auto* parentLayer = enclosingLayer()) {
+            auto compLayerStatus = parentLayer->enclosingCompositingLayerForRepaint();
+            if (compLayerStatus.layer) {
+                repaintContainer = &compLayerStatus.layer->renderer();
+                fullRepaintAlreadyScheduled = compLayerStatus.fullRepaintAlreadyScheduled;
+            }
         }
     }
     if (view().hasSoftwareFilters()) {
-        if (RenderLayer* parentLayer = enclosingLayer()) {
-            RenderLayer* enclosingFilterLayer = parentLayer->enclosingFilterLayer();
-            if (enclosingFilterLayer)
-                return { false, &enclosingFilterLayer->renderer() };
+        if (auto* parentLayer = enclosingLayer()) {
+            auto* enclosingFilterLayer = parentLayer->enclosingFilterLayer();
+            if (enclosingFilterLayer) {
+                fullRepaintAlreadyScheduled = parentLayer->needsFullRepaint();
+                return { fullRepaintAlreadyScheduled, &enclosingFilterLayer->renderer() };
+            }
         }
     }
@@ -888 +893 @@
             repaintContainer = parentRenderFragmentedFlow;
     }
-    return { false, repaintContainer };
+    return { fullRepaintAlreadyScheduled, repaintContainer };
 }
 
@@ -962 +967 @@
 }
 
+static inline bool fullRepaintIsScheduled(const RenderObject& renderer)
+{
+    if (!renderer.view().usesCompositing() && !renderer.document().ownerElement())
+        return false;
+    for (auto* ancestorLayer = renderer.enclosingLayer(); ancestorLayer; ancestorLayer = ancestorLayer->paintOrderParent()) {
+        if (ancestorLayer->needsFullRepaint())
+            return true;
+    }
+    return false;
+}
+
 void RenderObject::repaint() const
 {
@@ -973 +989 @@
 
     auto repaintContainer = containerForRepaint();
+    if (!repaintContainer.renderer)
+        repaintContainer = { fullRepaintIsScheduled(*this), &view };
+
     if (!repaintContainer.fullRepaintIsScheduled)
         repaintUsingContainer(repaintContainer.renderer, clippedOverflowRectForRepaint(repaintContainer.renderer));
@@ -993 +1012 @@
 
     auto repaintContainer = containerForRepaint();
+    if (!repaintContainer.renderer)
+        repaintContainer = { fullRepaintIsScheduled(*this), &view };
+
     if (!repaintContainer.fullRepaintIsScheduled)
         repaintUsingContainer(repaintContainer.renderer, computeRectForRepaint(dirtyRect, repaintContainer.renderer), shouldClipToLayer);