Support subpixel layout for borders.

third_party/WebKit/Source/core/style/ComputedStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 45 matching lines @@
 #include "wtf/PtrUtil.h"
 #include "wtf/SaturatedArithmetic.h"
 #include "wtf/SizeAssertions.h"
 #include <algorithm>
 #include <memory>
 
 namespace blink {
 
 struct SameSizeAsBorderValue {
   RGBA32 m_color;
-  unsigned m_width;
+  float m_width;
+  unsigned m_bitfield;
 };
 
 ASSERT_SIZE(BorderValue, SameSizeAsBorderValue);
 
 // Since different compilers/architectures pack ComputedStyle differently,
 // re-create the same structure for an accurate size comparison.
 struct SameSizeAsComputedStyle : public ComputedStyleBase,
                                  public RefCounted<ComputedStyle> {
   void* dataRefs[7];
   void* ownPtrs[1];
@@ skipping 2138 matching lines @@
     return isLeftToRightDirection() ? borderLeft() : borderRight();
   return isLeftToRightDirection() ? borderTop() : borderBottom();
 }
 
 const BorderValue& ComputedStyle::borderEnd() const {
   if (isHorizontalWritingMode())
     return isLeftToRightDirection() ? borderRight() : borderLeft();
   return isLeftToRightDirection() ? borderBottom() : borderTop();
 }
 
-int ComputedStyle::borderBeforeWidth() const {
+float ComputedStyle::borderBeforeWidth() const {
   switch (getWritingMode()) {
     case WritingMode::kHorizontalTb:
       return borderTopWidth();
     case WritingMode::kVerticalLr:
       return borderLeftWidth();
     case WritingMode::kVerticalRl:
       return borderRightWidth();
   }
   ASSERT_NOT_REACHED();
   return borderTopWidth();
 }
 
-int ComputedStyle::borderAfterWidth() const {
+float ComputedStyle::borderAfterWidth() const {
   switch (getWritingMode()) {
     case WritingMode::kHorizontalTb:
       return borderBottomWidth();
     case WritingMode::kVerticalLr:
       return borderRightWidth();
     case WritingMode::kVerticalRl:
       return borderLeftWidth();
   }
   ASSERT_NOT_REACHED();
   return borderBottomWidth();
 }
 
-int ComputedStyle::borderStartWidth() const {
+float ComputedStyle::borderStartWidth() const {
   if (isHorizontalWritingMode())
     return isLeftToRightDirection() ? borderLeftWidth() : borderRightWidth();
   return isLeftToRightDirection() ? borderTopWidth() : borderBottomWidth();
 }
 
-int ComputedStyle::borderEndWidth() const {
+float ComputedStyle::borderEndWidth() const {
   if (isHorizontalWritingMode())
     return isLeftToRightDirection() ? borderRightWidth() : borderLeftWidth();
   return isLeftToRightDirection() ? borderBottomWidth() : borderTopWidth();
 }
 
-int ComputedStyle::borderOverWidth() const {
+float ComputedStyle::borderOverWidth() const {
   return isHorizontalWritingMode() ? borderTopWidth() : borderRightWidth();
 }
 
-int ComputedStyle::borderUnderWidth() const {
+float ComputedStyle::borderUnderWidth() const {
   return isHorizontalWritingMode() ? borderBottomWidth() : borderLeftWidth();
 }
 
 void ComputedStyle::setMarginStart(const Length& margin) {
   if (isHorizontalWritingMode()) {
     if (isLeftToRightDirection())
       setMarginLeft(margin);
     else
       setMarginRight(margin);
   } else {
@@ skipping 202 matching lines @@
     if (value < 0)
       fvalue -= 0.5f;
     else
       fvalue += 0.5f;
   }
 
   return roundForImpreciseConversion<int>(fvalue / zoomFactor);
 }
 
 }  // namespace blink