Subpixel layout: setSimpleLineLayoutEnabled() produces different layo…

…ut when line position has CSS px fractions.

https://bugs.webkit.org/show_bug.cgi?id=126892

Reviewed by Antti Koivisto.

SimpleLineLayout needs to copy normal linebox layout's subpixel rounding strategy to produce
the same layout.

Source/WebCore:

Covered by existing tests.

* rendering/SimpleLineLayoutFunctions.cpp:
(WebCore::SimpleLineLayout::paintFlow):

LayoutTests:

* platform/mac/TestExpectations: Unskipping some SimpleLineLayout tests.


Canonical link: https://commits.webkit.org/145271@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@162340 268f45cc-cd09-0410-ab3c-d52691b4dbfc

LayoutTests/ChangeLog

@@ -1,3 +1,15 @@
+2014-01-20  Zalan Bujtas  <zalan@apple.com>
+
+        Subpixel layout: setSimpleLineLayoutEnabled() produces different layout when line position has CSS px fractions.
+        https://bugs.webkit.org/show_bug.cgi?id=126892
+
+        Reviewed by Antti Koivisto.
+
+        SimpleLineLayout needs to copy normal linebox layout's subpixel rounding strategy to produce
+        the same layout.
+
+        * platform/mac/TestExpectations: Unskipping some SimpleLineLayout tests. 
+
 2014-01-20  Michał Pakuła vel Rutka  <m.pakula@samsung.com>
 
         Unreviewed EFL gardening

LayoutTests/platform/mac/TestExpectations

@@ -1329,21 +1329,8 @@ webkit.org/b/117756 media/track/media-element-enqueue-event-crash.html [ Skip ]
 webkit.org/b/126889 fast/forms/input-widths.html
 webkit.org/b/126889 fast/forms/number/number-size.html
 
-# Subpixel: simple line layout produces different layout
-webkit.org/b/126892 fast/css/word-spacing-between-blocks.html
-webkit.org/b/126892 fast/css/word-spacing-between-inlines.html
-webkit.org/b/126892 fast/forms/textAreaLineHeight-simple-lines.html
-webkit.org/b/126892 fast/regions/floats-basic-in-variable-width-regions.html
-webkit.org/b/126892 fast/regions/overflow-moving-below-floats-in-variable-width-regions.html
-webkit.org/b/126892 fast/regions/overflow-not-moving-below-floats-in-variable-width-regions.html
-webkit.org/b/126892 fast/regions/overflow-size-change-in-variable-width-regions.html
-webkit.org/b/126892 fast/regions/overflow-size-change-with-stacking-context.html
-webkit.org/b/126892 fast/regions/selection/selecting-text-through-different-region-flows.html
-webkit.org/b/126892 fast/shapes/shape-inside/shape-inside-circle-padding.html
-webkit.org/b/126892 fast/shapes/shape-inside/shape-inside-circle.html
-webkit.org/b/126892 fast/shapes/shape-inside/shape-inside-ellipse-padding.html
-webkit.org/b/126892 fast/shapes/shape-inside/shape-inside-ellipse.html
-webkit.org/b/126892 fast/shapes/shape-inside/shape-inside-rounded-rectangle-fit-002.html
+# Subpixel: regions with different widths.
+webkit.org/b/127212 fast/regions/overflow-moving-below-floats-in-variable-width-regions.html
 
 # webkit.org/b/124784 needs revisiting.
 webkit.org/b/124784 fast/shapes/shape-inside/shape-inside-subpixel-rectangle-top.html

Source/WebCore/ChangeLog

@@ -1,3 +1,18 @@
+2014-01-20  Zalan Bujtas  <zalan@apple.com>
+
+        Subpixel layout: setSimpleLineLayoutEnabled() produces different layout when line position has CSS px fractions.
+        https://bugs.webkit.org/show_bug.cgi?id=126892
+
+        Reviewed by Antti Koivisto.
+
+        SimpleLineLayout needs to copy normal linebox layout's subpixel rounding strategy to produce
+        the same layout.
+
+        Covered by existing tests.
+
+        * rendering/SimpleLineLayoutFunctions.cpp:
+        (WebCore::SimpleLineLayout::paintFlow):
+
 2014-01-20  Gurpreet Kaur  <k.gurpreet@samsung.com>
 
         Col width is not honored when dynamically updated and it would make table narrower

Source/WebCore/rendering/SimpleLineLayoutFunctions.cpp

@@ -54,9 +54,9 @@ static void paintDebugBorders(GraphicsContext& context, const LayoutRect& border
     GraphicsContextStateSaver stateSaver(context);
     context.setStrokeColor(Color(0, 255, 0), ColorSpaceDeviceRGB);
     context.setFillColor(Color::transparent, ColorSpaceDeviceRGB);
-    IntRect rect(pixelSnappedIntRect(borderRect));
-    rect.moveBy(flooredIntPoint(paintOffset));
-    context.drawRect(rect);
+    LayoutRect rect(borderRect);
+    rect.moveBy(paintOffset);
+    context.drawRect(pixelSnappedIntRect(rect));
 }
 
 void paintFlow(const RenderBlockFlow& flow, const Layout& layout, PaintInfo& paintInfo, const LayoutPoint& paintOffset)
@@ -80,9 +80,10 @@ void paintFlow(const RenderBlockFlow& flow, const Layout& layout, PaintInfo& pai
     GraphicsContextStateSaver stateSaver(context, textPaintStyle.strokeWidth > 0);
 
     updateGraphicsContext(context, textPaintStyle);
+    LayoutPoint adjustedPaintOffset = roundedIntPoint(paintOffset);
 
     LayoutRect paintRect = paintInfo.rect;
-    paintRect.moveBy(-paintOffset);
+    paintRect.moveBy(-adjustedPaintOffset);
 
     auto resolver = runResolver(flow, layout);
     auto range = resolver.rangeForRect(paintRect);
@@ -92,9 +93,9 @@ void paintFlow(const RenderBlockFlow& flow, const Layout& layout, PaintInfo& pai
             continue;
         TextRun textRun(run.text());
         textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
-        context.drawText(font, textRun, run.baseline() + paintOffset);
+        context.drawText(font, textRun, run.baseline() + adjustedPaintOffset);
         if (debugBordersEnabled)
-            paintDebugBorders(context, run.rect(), paintOffset);
+            paintDebugBorders(context, run.rect(), adjustedPaintOffset);
     }
 }