Offset-only GlyphBuffer

Source/platform/fonts/shaping/SimpleShaper.cpp

 /*
  * Copyright (C) 2003, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Holger Hans Peter Freyther
  * Copyright (C) 2014 Google Inc. 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 80 matching lines @@
 
 void SimpleShaper::cacheFallbackFont(const SimpleFontData* fontData,
     const SimpleFontData* primaryFont)
 {
     if (fontData == primaryFont)
         return;
 
     m_fallbackFonts->add(fontData);
 }
 
-float SimpleShaper::adjustSpacing(float width, const CharacterData& charData,
-    const SimpleFontData& fontData, GlyphBuffer* glyphBuffer)
+float SimpleShaper::adjustSpacing(float width, const CharacterData& charData)
 {
     // Account for letter-spacing.
     if (width)
         width += m_font->fontDescription().letterSpacing();
 
     bool treatAsSpace = Character::treatAsSpace(charData.character);
     if (treatAsSpace) {
         // Distribute the run's total expansion evenly over all expansion opportunities in the run.
         if (m_expansion) {
             if (!treatAsSpace && !m_isAfterExpansion) {
                 // Take the expansion opportunity before this ideograph.
                 m_expansion -= m_expansionPerOpportunity;
-                float expansionAtThisOpportunity = m_expansionPerOpportunity;
-                m_runWidthSoFar += expansionAtThisOpportunity;
-                if (glyphBuffer) {
-                    if (glyphBuffer->isEmpty()) {
-                        if (m_forTextEmphasis)
-                            glyphBuffer->add(fontData.zeroWidthSpaceGlyph(), &fontData, m_expansionPerOpportunity);
-                        else
-                            glyphBuffer->add(fontData.spaceGlyph(), &fontData, expansionAtThisOpportunity);
-                    } else {
-                        glyphBuffer->expandLastAdvance(expansionAtThisOpportunity);
-                    }
-                }
+                m_runWidthSoFar += m_expansionPerOpportunity;
             }
             if (m_run.allowsTrailingExpansion()
                 || (m_run.ltr() && charData.characterOffset + charData.clusterLength < static_cast<size_t>(m_run.length()))
                 || (m_run.rtl() && charData.characterOffset)) {
                 m_expansion -= m_expansionPerOpportunity;
                 width += m_expansionPerOpportunity;
                 m_isAfterExpansion = true;
             }
         } else {
             m_isAfterExpansion = false;
@@ skipping 58 matching lines @@
         Glyph glyph = glyphData.glyph;
         const SimpleFontData* fontData = glyphData.fontData;
         ASSERT(fontData);
 
         if (m_fallbackFonts && lastFontData != fontData && width) {
             lastFontData = fontData;
             cacheFallbackFont(fontData, primaryFont);
         }
 
         if (hasExtraSpacing && !spaceUsedAsZeroWidthSpace)
-            width = adjustSpacing(width, charData, *fontData, glyphBuffer);
+            width = adjustSpacing(width, charData);
 
         if (m_bounds)
             updateGlyphBounds(glyphData, width, !charData.characterOffset);
 
-        if (m_forTextEmphasis && !Character::canReceiveTextEmphasis(charData.character))
-            glyph = 0;
+        if (m_forTextEmphasis) {
+            if (!Character::canReceiveTextEmphasis(charData.character))
+                glyph = 0;
+
+            // The emphasis code expects mid-glyph offsets.
+            width /= 2;
+            m_runWidthSoFar += width;
+        }
+
+        if (glyphBuffer)
+            glyphBuffer->add(glyph, fontData, m_runWidthSoFar);
 
         // Advance past the character we just dealt with.
         textIterator.advance(charData.clusterLength);
         m_runWidthSoFar += width;
-
-        if (glyphBuffer)
-            glyphBuffer->add(glyph, fontData, width);
     }
 
     unsigned consumedCharacters = textIterator.currentCharacter() - m_currentCharacter;
     m_currentCharacter = textIterator.currentCharacter();
 
     return consumedCharacters;
 }
 
 unsigned SimpleShaper::advance(unsigned offset, GlyphBuffer* glyphBuffer)
 {
@@ skipping 19 matching lines @@
     float initialWidth = m_runWidthSoFar;
 
     if (!advance(m_currentCharacter + 1))
         return false;
 
     width = m_runWidthSoFar - initialWidth;
     return true;
 }
 
 } // namespace blink