Correcting text baseline for tiny fonts

third_party/WebKit/Source/platform/fonts/FontDescription.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 96 matching lines @@
     m_fields.m_historicalLigaturesState = NormalLigaturesState;
     m_fields.m_contextualLigaturesState = NormalLigaturesState;
     m_fields.m_keywordSize = 0;
     m_fields.m_fontSmoothing = AutoSmoothing;
     m_fields.m_textRendering = AutoTextRendering;
     m_fields.m_syntheticBold = false;
     m_fields.m_syntheticItalic = false;
     m_fields.m_subpixelTextPosition = s_useSubpixelTextPositioning;
     m_fields.m_typesettingFeatures = s_defaultTypesettingFeatures;
     m_fields.m_variantNumeric = FontVariantNumeric().m_fieldsAsUnsigned;
+    m_fields.m_subpixelAscentDescent = false;
   }
 
   bool operator==(const FontDescription&) const;
   bool operator!=(const FontDescription& other) const {
     return !(*this == other);
   }
 
   struct VariantLigatures {
     STACK_ALLOCATED();
     VariantLigatures(LigaturesState state = NormalLigaturesState)
@@ skipping 186 matching lines @@
 
   TypesettingFeatures getTypesettingFeatures() const {
     return static_cast<TypesettingFeatures>(m_fields.m_typesettingFeatures);
   }
 
   static void setSubpixelPositioning(bool b) {
     s_useSubpixelTextPositioning = b;
   }
   static bool subpixelPositioning() { return s_useSubpixelTextPositioning; }
 
+  void setSubpixelAscentDescent(bool sp) const {
+    m_fields.m_subpixelAscentDescent = sp;
+  }
+
+  bool subpixelAscentDescent() const {
+    return m_fields.m_subpixelAscentDescent;
+  }
+
   static void setDefaultTypesettingFeatures(TypesettingFeatures);
   static TypesettingFeatures defaultTypesettingFeatures();
 
   unsigned styleHashWithoutFamilyList() const;
   // TODO(drott): We should not expose internal structure here, but rather
   // introduce a hash function here.
   unsigned bitmapFields() const { return m_fieldsAsUnsigned.parts[0]; }
   unsigned auxiliaryBitmapFields() const { return m_fieldsAsUnsigned.parts[1]; }
 
   SkFontStyle skiaFontStyle() const;
@@ skipping 51 matching lines @@
     // values for <font>).
     unsigned m_keywordSize : 4;
 
     unsigned m_fontSmoothing : 2;  // FontSmoothingMode
     unsigned m_textRendering : 2;  // TextRenderingMode
     unsigned m_syntheticBold : 1;
     unsigned m_syntheticItalic : 1;
     unsigned m_subpixelTextPosition : 1;
     unsigned m_typesettingFeatures : 3;
     unsigned m_variantNumeric : 8;
+    mutable unsigned m_subpixelAscentDescent : 1;
   };
 
   static_assert(sizeof(BitFields) == sizeof(FieldsAsUnsignedType),
                 "Mapped bitfield datatypes must have identical size.");
   union {
     BitFields m_fields;
     FieldsAsUnsignedType m_fieldsAsUnsigned;
   };
 
   static TypesettingFeatures s_defaultTypesettingFeatures;
@@ skipping 12 matching lines @@
          m_fieldsAsUnsigned.parts[0] == other.m_fieldsAsUnsigned.parts[0] &&
          m_fieldsAsUnsigned.parts[1] == other.m_fieldsAsUnsigned.parts[1] &&
          (m_featureSettings == other.m_featureSettings ||
           (m_featureSettings && other.m_featureSettings &&
            *m_featureSettings == *other.m_featureSettings));
 }
 
 }  // namespace blink
 
 #endif