Subpixel rendering: Region painting needs to take subpixel accumulation into account.

https://bugs.webkit.org/show_bug.cgi?id=135469

Similar to non-region painting, when the context is translated, we need to propagate
the subpixel difference so that renderers get snapped to the same position as if they
were not part of a region.

Reviewed by Simon Fraser.

Covered by existing tests/not testable (webkit.org/b/135470)

* html/shadow/MediaControlElements.cpp:
(WebCore::MediaControlTextTrackContainerElement::createTextTrackRepresentationImage):
* page/FrameView.cpp:
(WebCore::FrameView::paintContents):
* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::paint):
(WebCore::RenderLayer::calculateClipRects):
* rendering/RenderLayer.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@171896 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 4a2086f..afb7cc0 100644 (file)
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,25 @@
+2014-07-31  Zalan Bujtas  <zalan@apple.com>
+
+        Subpixel rendering: Region painting needs to take subpixel accumulation into account.
+        https://bugs.webkit.org/show_bug.cgi?id=135469
+
+        Similar to non-region painting, when the context is translated, we need to propagate
+        the subpixel difference so that renderers get snapped to the same position as if they
+        were not part of a region.
+
+        Reviewed by Simon Fraser.
+
+        Covered by existing tests/not testable (webkit.org/b/135470)
+
+        * html/shadow/MediaControlElements.cpp:
+        (WebCore::MediaControlTextTrackContainerElement::createTextTrackRepresentationImage):
+        * page/FrameView.cpp:
+        (WebCore::FrameView::paintContents):
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::paint):
+        (WebCore::RenderLayer::calculateClipRects):
+        * rendering/RenderLayer.h:
+
 2014-07-31  Jer Noble  <jer.noble@apple.com>
 
         [iOS] Video in an <embed> has a bad aspect ratio when in fullscreen mode.

diff --git a/Source/WebCore/html/shadow/MediaControlElements.cpp b/Source/WebCore/html/shadow/MediaControlElements.cpp
index 8adb790..559201a 100644 (file)
--- a/Source/WebCore/html/shadow/MediaControlElements.cpp
+++ b/Source/WebCore/html/shadow/MediaControlElements.cpp
@@ -1534,7 +1534,7 @@ PassRefPtr<Image> MediaControlTextTrackContainerElement::createTextTrackRepresen
     if (!buffer)
         return nullptr;
 
-    layer->paint(buffer->context(), paintingRect, PaintBehaviorFlattenCompositingLayers, nullptr, RenderLayer::PaintLayerPaintingCompositingAllPhases);
+    layer->paint(buffer->context(), paintingRect, LayoutSize(), PaintBehaviorFlattenCompositingLayers, nullptr, RenderLayer::PaintLayerPaintingCompositingAllPhases);
 
     return buffer->copyImage();
 }

diff --git a/Source/WebCore/page/FrameView.cpp b/Source/WebCore/page/FrameView.cpp
index 09020f8..d0eb39a 100644 (file)
--- a/Source/WebCore/page/FrameView.cpp
+++ b/Source/WebCore/page/FrameView.cpp
@@ -3690,7 +3690,7 @@ void FrameView::paintContents(GraphicsContext* context, const IntRect& dirtyRect
     while (eltRenderer && eltRenderer->isRenderInline() && !toRenderInline(eltRenderer)->firstLineBox())
         eltRenderer = eltRenderer->parent();
 
-    rootLayer->paint(context, dirtyRect, m_paintBehavior, eltRenderer);
+    rootLayer->paint(context, dirtyRect, LayoutSize(), m_paintBehavior, eltRenderer);
     if (rootLayer->containsDirtyOverlayScrollbars())
         rootLayer->paintOverlayScrollbars(context, dirtyRect, m_paintBehavior, eltRenderer);
 

diff --git a/Source/WebCore/rendering/RenderLayer.cpp b/Source/WebCore/rendering/RenderLayer.cpp
index 4393b64..fc3e11a 100644 (file)
--- a/Source/WebCore/rendering/RenderLayer.cpp
+++ b/Source/WebCore/rendering/RenderLayer.cpp
@@ -3546,11 +3546,11 @@ bool RenderLayer::scroll(ScrollDirection direction, ScrollGranularity granularit
     return ScrollableArea::scroll(direction, granularity, multiplier);
 }
 
-void RenderLayer::paint(GraphicsContext* context, const LayoutRect& damageRect, PaintBehavior paintBehavior, RenderObject* subtreePaintRoot, PaintLayerFlags paintFlags)
+void RenderLayer::paint(GraphicsContext* context, const LayoutRect& damageRect, const LayoutSize& subpixelAccumulation, PaintBehavior paintBehavior, RenderObject* subtreePaintRoot, PaintLayerFlags paintFlags)
 {
     OverlapTestRequestMap overlapTestRequests;
 
-    LayerPaintingInfo paintingInfo(this, enclosingIntRect(damageRect), paintBehavior, LayoutSize(), subtreePaintRoot, &overlapTestRequests);
+    LayerPaintingInfo paintingInfo(this, enclosingIntRect(damageRect), paintBehavior, subpixelAccumulation, subtreePaintRoot, &overlapTestRequests);
     paintLayer(context, paintingInfo, paintFlags);
 
     OverlapTestRequestMap::iterator end = overlapTestRequests.end();
@@ -6680,21 +6680,19 @@ void RenderLayer::filterNeedsRepaint()
 void RenderLayer::paintNamedFlowThreadInsideRegion(GraphicsContext* context, RenderNamedFlowFragment* region, LayoutRect paintDirtyRect, LayoutPoint paintOffset, PaintBehavior paintBehavior, PaintLayerFlags paintFlags)
 {
     LayoutRect regionContentBox = toRenderBox(region->layerOwner()).contentBoxRect();
-    LayoutSize moveOffset = region->flowThreadPortionLocation() - (paintOffset + regionContentBox.location()) + region->fragmentContainer().scrolledContentOffset();
-
-    FloatPoint adjustedPaintOffset = roundedForPainting(LayoutPoint(-moveOffset.width(), -moveOffset.height()), renderer().document().deviceScaleFactor());
-    paintDirtyRect.move(moveOffset);
-
-    context->save();
-    context->translate(adjustedPaintOffset.x(), adjustedPaintOffset.y());
-
     CurrentRenderFlowThreadMaintainer flowThreadMaintainer(toRenderFlowThread(&renderer()));
     CurrentRenderRegionMaintainer regionMaintainer(*region);
-
     region->setRegionObjectsRegionStyle();
-    paint(context, paintDirtyRect, paintBehavior, nullptr, paintFlags | PaintLayerTemporaryClipRects);
-    region->restoreRegionObjectsOriginalStyle();
 
+    LayoutSize moveOffset = region->flowThreadPortionLocation() - (paintOffset + regionContentBox.location()) + region->fragmentContainer().scrolledContentOffset();
+    FloatPoint adjustedPaintOffset = roundedForPainting(toLayoutPoint(moveOffset), renderer().document().deviceScaleFactor());
+    context->save();
+    context->translate(-adjustedPaintOffset.x(), -adjustedPaintOffset.y());
+
+    LayoutSize subpixelAccumulation = moveOffset - toLayoutSize(LayoutPoint(adjustedPaintOffset));
+    paintDirtyRect.move(moveOffset);
+    paint(context, paintDirtyRect, subpixelAccumulation, paintBehavior, nullptr, paintFlags | PaintLayerTemporaryClipRects);
+    region->restoreRegionObjectsOriginalStyle();
     context->restore();
 }
 

diff --git a/Source/WebCore/rendering/RenderLayer.h b/Source/WebCore/rendering/RenderLayer.h
index 2aa4957..26ccf63 100644 (file)
--- a/Source/WebCore/rendering/RenderLayer.h
+++ b/Source/WebCore/rendering/RenderLayer.h
@@ -671,7 +671,8 @@ public:
     // paints the layers that intersect the damage rect from back to
     // front.  The hitTest method looks for mouse events by walking
     // layers that intersect the point from front to back.
-    void paint(GraphicsContext*, const LayoutRect& damageRect, PaintBehavior = PaintBehaviorNormal, RenderObject* subtreePaintRoot = nullptr, PaintLayerFlags = 0);
+    void paint(GraphicsContext*, const LayoutRect& damageRect, const LayoutSize& subpixelAccumulation = LayoutSize(), PaintBehavior = PaintBehaviorNormal,
+        RenderObject* subtreePaintRoot = nullptr, PaintLayerFlags = 0);
     bool hitTest(const HitTestRequest&, HitTestResult&);
     bool hitTest(const HitTestRequest&, const HitTestLocation&, HitTestResult&);
     void paintOverlayScrollbars(GraphicsContext*, const LayoutRect& damageRect, PaintBehavior, RenderObject* subtreePaintRoot = nullptr);