Changeset 167562 in webkit

Timestamp:

Apr 19, 2014, 8:38:09 PM (12 years ago)

Author:

Alan Bujtas

Message:

Subpixel rendering: RenderLayer's clipping should snap to device pixel boundaries.
​https://bugs.webkit.org/show_bug.cgi?id=131466

Reviewed by Simon Fraser.

Fractional pixel clipping can produce cruft on RenderLayers. Since RenderLayer
sizing and painting are snapped, painting clip rect needs to be snapped the same way.

Source/WebCore:
Test: fast/clip/clip-when-rect-has-fractional-pixel-value.html

• rendering/RenderLayer.cpp:

(WebCore::RenderLayer::clipToRect):

LayoutTests:

• fast/clip/clip-when-rect-has-fractional-pixel-value-expected.html: Added.
• fast/clip/clip-when-rect-has-fractional-pixel-value.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/clip/clip-when-rect-has-fractional-pixel-value-expected.html (added)
• LayoutTests/fast/clip/clip-when-rect-has-fractional-pixel-value.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayer.cpp (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2014-04-19  Zalan Bujtas  <zalan@apple.com>
+
+        Subpixel rendering: RenderLayer's clipping should snap to device pixel boundaries.
+        https://bugs.webkit.org/show_bug.cgi?id=131466
+
+        Reviewed by Simon Fraser.
+
+        Fractional pixel clipping can produce cruft on RenderLayers. Since RenderLayer
+        sizing and painting are snapped, painting clip rect needs to be snapped the same way.
+
+        * fast/clip/clip-when-rect-has-fractional-pixel-value-expected.html: Added.
+        * fast/clip/clip-when-rect-has-fractional-pixel-value.html: Added.
+
 2014-04-19  Chris Fleizach  <cfleizach@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2014-04-19  Zalan Bujtas  <zalan@apple.com>
+
+        Subpixel rendering: RenderLayer's clipping should snap to device pixel boundaries.
+        https://bugs.webkit.org/show_bug.cgi?id=131466
+
+        Reviewed by Simon Fraser.
+
+        Fractional pixel clipping can produce cruft on RenderLayers. Since RenderLayer
+        sizing and painting are snapped, painting clip rect needs to be snapped the same way.
+
+        Test: fast/clip/clip-when-rect-has-fractional-pixel-value.html
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::clipToRect):
+
 2014-04-19  Brent Fulgham  <bfulgham@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -3631 +3631 @@
                              BorderRadiusClippingRule rule)
 {
+    float deviceScaleFactor = renderer().document().deviceScaleFactor();
     if (clipRect.rect() != paintDirtyRect || clipRect.hasRadius()) {
         context->save();
-        context->clip(clipRect.rect());
+        context->clip(pixelSnappedForPainting(clipRect.rect(), deviceScaleFactor));
     }
 
@@ -3646 +3647 @@
                 LayoutPoint delta;
                 layer->convertToLayerCoords(rootLayer, delta);
-                context->clipRoundedRect(FloatRoundedRect(layer->renderer().style().getRoundedInnerBorderFor(LayoutRect(delta, layer->size()))));
+                context->clipRoundedRect(layer->renderer().style().getRoundedInnerBorderFor(LayoutRect(delta, layer->size())).pixelSnappedRoundedRectForPainting(deviceScaleFactor));
         }