Changeset 246017 in webkit

Timestamp:

Jun 1, 2019, 2:40:04 PM (7 years ago)

Author:

Simon Fraser

Message:

Non-composited negative z-order children should not trigger creation of a foreground layer
​https://bugs.webkit.org/show_bug.cgi?id=198455

Reviewed by Sam Weinig.
Source/WebCore:

The existing code triggered creation of a foreground layer on RenderLayerBacking when
the negative z-order list was non-empty. This isn't necessary; we can paint the negative
z-order children just fine.

We only need a foreground layer when the negative z-order layers are composited or
have composited descendants.

This will reduce backing store memory use in some cases.

Test: compositing/layer-creation/composited-negative-z-subtree.html

• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::computeCompositingRequirements):
(WebCore::RenderLayerCompositor::updateBackingAndHierarchy):
(WebCore::RenderLayerCompositor::needsContentsCompositingLayer const):

LayoutTests:

Change existing tests that use negative z-order layers to trigger foreground layer
creation to use compositing on those negative z-order layers.

• compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt:
• compositing/geometry/bounds-ignores-hidden-dynamic-negzindex.html:
• compositing/geometry/bounds-ignores-hidden-expected.txt:
• compositing/geometry/bounds-ignores-hidden.html:
• compositing/layer-creation/composited-negative-z-subtree-expected.txt: Added.
• compositing/layer-creation/composited-negative-z-subtree.html: Added.
• compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
• compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases.html:
• platform/ios-wk2/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt:
• platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
• platform/mac-wk1/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt (modified) (2 diffs)
• LayoutTests/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex.html (modified) (3 diffs)
• LayoutTests/compositing/geometry/bounds-ignores-hidden-expected.txt (modified) (1 diff)
• LayoutTests/compositing/geometry/bounds-ignores-hidden.html (modified) (2 diffs)
• LayoutTests/compositing/layer-creation/composited-negative-z-subtree-expected.txt (added)
• LayoutTests/compositing/layer-creation/composited-negative-z-subtree.html (added)
• LayoutTests/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt (modified) (1 diff)
• LayoutTests/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases.html (modified) (1 diff)
• LayoutTests/platform/ios-wk2/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt (modified) (2 diffs)
• LayoutTests/platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt (modified) (1 diff)
• LayoutTests/platform/mac-wk1/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerCompositor.cpp (modified) (3 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2019-06-01  Simon Fraser  <simon.fraser@apple.com>
+
+        Non-composited negative z-order children should not trigger creation of a foreground layer
+        https://bugs.webkit.org/show_bug.cgi?id=198455
+
+        Reviewed by Sam Weinig.
+        
+        Change existing tests that use negative z-order layers to trigger foreground layer
+        creation to use compositing on those negative z-order layers.
+
+        * compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt:
+        * compositing/geometry/bounds-ignores-hidden-dynamic-negzindex.html:
+        * compositing/geometry/bounds-ignores-hidden-expected.txt:
+        * compositing/geometry/bounds-ignores-hidden.html:
+        * compositing/layer-creation/composited-negative-z-subtree-expected.txt: Added.
+        * compositing/layer-creation/composited-negative-z-subtree.html: Added.
+        * compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
+        * compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases.html:
+        * platform/ios-wk2/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt:
+        * platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
+        * platform/mac-wk1/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
+
 2019-06-01  Devin Rousso  <drousso@apple.com>
 

trunk/LayoutTests/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt

@@ -13 +13 @@
           (bounds 500.00 250.00)
           (drawsContent 1)
-          (children 1
+          (children 2
+            (GraphicsLayer
+              (position 50.00 50.00)
+              (bounds 100.00 100.00)
+              (contentsOpaque 1)
+              (drawsContent 1)
+            )
             (GraphicsLayer
               (bounds 500.00 250.00)
@@ -22 +28 @@
         (GraphicsLayer
           (position 0.00 250.00)
-          (anchor 0.33 0.33)
-          (bounds 150.00 150.00)
+          (bounds 100.00 100.00)
           (drawsContent 1)
-          (children 1
+          (children 2
             (GraphicsLayer
-              (bounds 150.00 150.00)
+              (position 50.00 50.00)
+              (bounds 100.00 100.00)
+              (contentsOpaque 1)
+              (drawsContent 1)
+            )
+            (GraphicsLayer
+              (bounds 100.00 100.00)
               (drawsContent 1)
             )

trunk/LayoutTests/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex.html

@@ -4 +4 @@
     }
     .composited {
-        -webkit-transform: translateZ(0);
+        transform: translateZ(0);
     }
 
@@ -80 +80 @@
     <div style="position: absolute; left: 0px; top: 0px; z-index: 0; " class="composited">
         <div class="inline"></div>
-        <img style="position: absolute; left: 50px; top: 50px; z-index: -1;">
+        <img class="composited" style="position: absolute; left: 50px; top: 50px; z-index: -1;">
         <img style="position: absolute; left: 400px; top: 150px; z-index: 0;" class="to-visible">
     </div>
@@ -86 +86 @@
     <div style="position: absolute; left: 0px; top: 250px; z-index: 0; " class="composited">
         <div class="inline"></div>
-        <img style="position: absolute; left: 50px; top: 50px; z-index: -1;">
+        <img class="composited" style="position: absolute; left: 50px; top: 50px; z-index: -1;">
         <img style="position: absolute; left: 400px; top: 150px; z-index: 0;" class="to-hidden">
     </div>

trunk/LayoutTests/compositing/geometry/bounds-ignores-hidden-expected.txt

@@ -9 +9 @@
       (children 1
         (GraphicsLayer
-          (offsetFromRenderer width=10 height=10)
-          (position 10.00 10.00)
-          (anchor -0.20 -0.20)
-          (bounds 50.00 50.00)
-          (contentsOpaque 1)
-          (drawsContent 1)
-          (children 1
+          (children 2
             (GraphicsLayer
-              (offsetFromRenderer width=10 height=10)
+              (position 10.00 10.00)
               (bounds 50.00 50.00)
+              (contentsOpaque 1)
               (drawsContent 1)
+            )
+            (GraphicsLayer
             )
           )

trunk/LayoutTests/compositing/geometry/bounds-ignores-hidden.html

@@ -1 +1 @@
 <style>
   .composited {
-    -webkit-transform: translateZ(0);
+    transform: translateZ(0);
   }
   
@@ -24 +24 @@
 <body>
     <div style="position: absolute; left: 0px; top: 0px; z-index: 106; " class="composited">
-        <img style="position: absolute; left: 10px; top: 10px; z-index: -2;">
+        <img class="composited" style="position: absolute; left: 10px; top: 10px; z-index: -2;">
         <img style="position: absolute; left: 44940px; top: 15013px; z-index: 0; visibility: hidden;">
     </div>

trunk/LayoutTests/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt

@@ -39 +39 @@
                     GraphicsLayerPaintCompositedScroll
                     )
-                  (children 1
+                  (children 2
+                    (GraphicsLayer
+                      (position 30.00 50.00)
+                      (bounds 100.00 100.00)
+                      (contentsOpaque 1)
+                      (paintingPhases
+                        GraphicsLayerPaintBackground
+                        GraphicsLayerPaintForeground
+                        )
+                    )
                     (GraphicsLayer
                       (offsetFromRenderer width=1 height=1)

trunk/LayoutTests/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases.html

@@ -24 +24 @@
             height: 100px;
             background-color: blue;
+            transform: translateZ(0);
         }
     </style>

trunk/LayoutTests/platform/ios-wk2/compositing/geometry/bounds-ignores-hidden-dynamic-negzindex-expected.txt

@@ -13 +13 @@
           (bounds 500.00 250.00)
           (drawsContent 1)
-          (children 1
+          (children 2
+            (GraphicsLayer
+              (position 50.00 50.00)
+              (bounds 100.00 100.00)
+              (contentsOpaque 1)
+              (drawsContent 1)
+            )
             (GraphicsLayer
               (bounds 500.00 250.00)
@@ -22 +28 @@
         (GraphicsLayer
           (position 0.00 250.00)
-          (anchor 0.33 0.33)
-          (bounds 150.00 150.00)
+          (bounds 100.00 100.00)
           (drawsContent 1)
-          (children 1
+          (children 2
             (GraphicsLayer
-              (bounds 150.00 150.00)
+              (position 50.00 50.00)
+              (bounds 100.00 100.00)
+              (contentsOpaque 1)
+              (drawsContent 1)
+            )
+            (GraphicsLayer
+              (bounds 100.00 100.00)
               (drawsContent 1)
             )

trunk/LayoutTests/platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt

@@ -39 +39 @@
                     GraphicsLayerPaintCompositedScroll
                     )
-                  (children 1
+                  (children 2
+                    (GraphicsLayer
+                      (position 30.00 50.00)
+                      (bounds 100.00 100.00)
+                      (contentsOpaque 1)
+                      (paintingPhases
+                        GraphicsLayerPaintBackground
+                        GraphicsLayerPaintForeground
+                        )
+                    )
                     (GraphicsLayer
                       (offsetFromRenderer width=1 height=1)

trunk/LayoutTests/platform/mac-wk1/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt

@@ -1 +1 @@
 Scrolled contents
+(GraphicsLayer
+  (anchor 0.00 0.00)
+  (bounds 800.00 600.00)
+  (paintingPhases
+    GraphicsLayerPaintBackground
+    GraphicsLayerPaintForeground
+    )
+  (children 1
+    (GraphicsLayer
+      (bounds 800.00 600.00)
+      (contentsOpaque 1)
+      (paintingPhases
+        GraphicsLayerPaintBackground
+        GraphicsLayerPaintForeground
+        )
+      (children 1
+        (GraphicsLayer
+          (position 8.00 8.00)
+          (bounds 322.00 322.00)
+          (drawsContent 1)
+          (paintingPhases
+            GraphicsLayerPaintBackground
+            )
+          (children 1
+            (GraphicsLayer
+              (offsetFromRenderer width=1 height=1)
+              (position 1.00 1.00)
+              (bounds 305.00 305.00)
+              (paintingPhases
+                GraphicsLayerPaintBackground
+                GraphicsLayerPaintForeground
+                )
+              (children 2
+                (GraphicsLayer
+                  (position 30.00 50.00)
+                  (bounds 100.00 100.00)
+                  (contentsOpaque 1)
+                  (paintingPhases
+                    GraphicsLayerPaintBackground
+                    GraphicsLayerPaintForeground
+                    )
+                )
+                (GraphicsLayer
+                  (offsetFromRenderer width=1 height=1)
+                  (bounds 305.00 305.00)
+                  (drawsContent 1)
+                  (paintingPhases
+                    GraphicsLayerPaintForeground
+                    )
+                )
+              )
+            )
+          )
+        )
+      )
+    )
+  )
+)
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-06-01  Simon Fraser  <simon.fraser@apple.com>
+
+        Non-composited negative z-order children should not trigger creation of a foreground layer
+        https://bugs.webkit.org/show_bug.cgi?id=198455
+
+        Reviewed by Sam Weinig.
+
+        The existing code triggered creation of a foreground layer on RenderLayerBacking when
+        the negative z-order list was non-empty. This isn't necessary; we can paint the negative
+        z-order children just fine.
+
+        We only need a foreground layer when the negative z-order layers are composited or
+        have composited descendants.
+
+        This will reduce backing store memory use in some cases.
+
+        Test: compositing/layer-creation/composited-negative-z-subtree.html
+
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::computeCompositingRequirements):
+        (WebCore::RenderLayerCompositor::updateBackingAndHierarchy):
+        (WebCore::RenderLayerCompositor::needsContentsCompositingLayer const):
+
 2019-06-01  Andy Estes  <aestes@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -979 +979 @@
         // (since we need to ensure that the -ve z-order child renders underneath our contents).
         if (!willBeComposited && currentState.subtreeIsCompositing) {
-            // make layer compositing
             layer.setIndirectCompositingReason(IndirectCompositingReason::BackgroundLayer);
             layerWillComposite();
@@ -1251 +1250 @@
     LayerListMutationDetector mutationChecker(layer);
 #endif
-    
+
     auto appendForegroundLayerIfNecessary = [&] {
         // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
@@ -3241 +3240 @@
 }
 
-// If an element has negative z-index children, those children render in front of the 
+// If an element has composited negative z-index children, those children render in front of the
 // layer background, so we need an extra 'contents' layer for the foreground of the layer object.
 bool RenderLayerCompositor::needsContentsCompositingLayer(const RenderLayer& layer) const
 {
-    return layer.hasNegativeZOrderLayers();
+    for (auto* layer : layer.negativeZOrderLayers()) {
+        if (layer->isComposited() || layer->hasCompositingDescendant())
+            return true;
+    }
+
+    return false;
 }