Changeset 245207 in webkit

Timestamp:

May 11, 2019 3:05:37 PM (5 years ago)

Author:

Simon Fraser

Message:

Translucent gradient rendering bug due to will-change transform
​https://bugs.webkit.org/show_bug.cgi?id=197654
<rdar://problem/50547664>

Reviewed by Dean Jackson.
Source/WebCore:

We failed to re-evaluate 'contentsOpaque' when a background changed, because this
happened in updateGeometry() and that doesn't run for background changes.

However, 'contentsOpaque' also requires knowing about geometry because we have to
turn it off when there's subpixel positioning, and updateConfiguration()
runs before updateGeometry().

So compute m_hasSubpixelRounding in updateGeometry() and set contentsOpaque in
updateAfterDescendants().

Test: compositing/contents-opaque/background-change-to-transparent.html

• rendering/RenderLayerBacking.cpp:

(WebCore::RenderLayerBacking::updateConfiguration):
(WebCore::RenderLayerBacking::updateGeometry):
(WebCore::RenderLayerBacking::updateAfterDescendants):

• rendering/RenderLayerBacking.h:

LayoutTests:

• compositing/contents-opaque/background-change-to-transparent-expected.txt: Added.
• compositing/contents-opaque/background-change-to-transparent.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/contents-opaque/background-change-to-transparent-expected.txt (added)
• LayoutTests/compositing/contents-opaque/background-change-to-transparent.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerBacking.cpp (modified) (3 diffs)
• Source/WebCore/rendering/RenderLayerBacking.h (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2019-05-11  Simon Fraser  <simon.fraser@apple.com>
+
+        Translucent gradient rendering bug due to will-change transform
+        https://bugs.webkit.org/show_bug.cgi?id=197654
+        <rdar://problem/50547664>
+
+        Reviewed by Dean Jackson.
+
+        * compositing/contents-opaque/background-change-to-transparent-expected.txt: Added.
+        * compositing/contents-opaque/background-change-to-transparent.html: Added.
+
 2019-05-11  Simon Fraser  <simon.fraser@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-05-11  Simon Fraser  <simon.fraser@apple.com>
+
+        Translucent gradient rendering bug due to will-change transform
+        https://bugs.webkit.org/show_bug.cgi?id=197654
+        <rdar://problem/50547664>
+
+        Reviewed by Dean Jackson.
+        
+        We failed to re-evaluate 'contentsOpaque' when a background changed, because this
+        happened in updateGeometry() and that doesn't run for background changes.
+        
+        However, 'contentsOpaque' also requires knowing about geometry because we have to
+        turn it off when there's subpixel positioning, and updateConfiguration()
+        runs before updateGeometry().
+        
+        So compute m_hasSubpixelRounding in updateGeometry() and set contentsOpaque in
+        updateAfterDescendants().
+
+        Test: compositing/contents-opaque/background-change-to-transparent.html
+
+        * rendering/RenderLayerBacking.cpp:
+        (WebCore::RenderLayerBacking::updateConfiguration):
+        (WebCore::RenderLayerBacking::updateGeometry):
+        (WebCore::RenderLayerBacking::updateAfterDescendants):
+        * rendering/RenderLayerBacking.h:
+
 2019-05-11  Simon Fraser  <simon.fraser@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayerBacking.cpp

@@ -820 +820 @@
 
     updateEventRegion();
-    
+
     // Requires layout.
     if (contentsInfo.isDirectlyCompositedImage())
@@ -1113 +1113 @@
     primaryGraphicsLayerOffsetFromRenderer = computeOffsetFromRenderer(-rendererOffset.fromPrimaryGraphicsLayer(), deviceScaleFactor());
     m_subpixelOffsetFromRenderer = primaryGraphicsLayerOffsetFromRenderer.m_subpixelOffset;
+    m_hasSubpixelRounding = !m_subpixelOffsetFromRenderer.isZero() || compositedBounds().size() != primaryGraphicsLayerRect.size();
 
     if (primaryGraphicsLayerOffsetFromRenderer.m_devicePixelOffset != m_graphicsLayer->offsetFromRenderer()) {
         m_graphicsLayer->setOffsetFromRenderer(primaryGraphicsLayerOffsetFromRenderer.m_devicePixelOffset);
         positionOverflowControlsLayers();
-    }
-
-    if (!m_isMainFrameRenderViewLayer && !m_isFrameLayerWithTiledBacking && !m_requiresBackgroundLayer) {
-        // For non-root layers, background is always painted by the primary graphics layer.
-        ASSERT(!m_backgroundLayer);
-        // Subpixel offset from graphics layer or size changed.
-        bool hadSubpixelRounding = !m_subpixelOffsetFromRenderer.isZero() || compositedBounds().size() != primaryGraphicsLayerRect.size();
-        m_graphicsLayer->setContentsOpaque(!hadSubpixelRounding && m_owningLayer.backgroundIsKnownToBeOpaqueInRect(compositedBounds()));
     }
 
@@ -1326 +1319 @@
 
     updateDrawsContent(contentsInfo);
+
+    if (!m_isMainFrameRenderViewLayer && !m_isFrameLayerWithTiledBacking && !m_requiresBackgroundLayer) {
+        // For non-root layers, background is always painted by the primary graphics layer.
+        ASSERT(!m_backgroundLayer);
+        m_graphicsLayer->setContentsOpaque(!m_hasSubpixelRounding && m_owningLayer.backgroundIsKnownToBeOpaqueInRect(compositedBounds()));
+    }
 
     m_graphicsLayer->setContentsVisible(m_owningLayer.hasVisibleContent() || hasVisibleNonCompositedDescendants());

trunk/Source/WebCore/rendering/RenderLayerBacking.h

@@ -435 +435 @@
     bool m_backgroundLayerPaintsFixedRootBackground { false };
     bool m_requiresBackgroundLayer { false };
+    bool m_hasSubpixelRounding { false };
     bool m_paintsSubpixelAntialiasedText { false }; // This is for logging only.
 };