Use glyph-ids for lookups of SVG font kerning-pairs

Source/core/rendering/svg/SVGTextLayoutEngineSpacing.cpp

 /*
  * Copyright (C) Research In Motion Limited 2010. 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 19 matching lines @@
 #include "core/svg/SVGFontData.h"
 #include "core/svg/SVGFontElement.h"
 #include "core/svg/SVGFontFaceElement.h"
 #endif
 
 namespace WebCore {
 
 SVGTextLayoutEngineSpacing::SVGTextLayoutEngineSpacing(const Font& font)
     : m_font(font)
     , m_lastCharacter(0)
+#if ENABLE(SVG_FONTS)
+    , m_lastGlyph(0)
+#endif
 {
 }
 
-float SVGTextLayoutEngineSpacing::calculateSVGKerning(bool isVerticalText, const SVGTextMetrics::Glyph& currentGlyph)
+float SVGTextLayoutEngineSpacing::calculateSVGKerning(bool isVerticalText, Glyph currentGlyph)
 {
 #if ENABLE(SVG_FONTS)
     const SimpleFontData* fontData = m_font.primaryFont();
     if (!fontData->isSVGFont()) {
-        m_lastGlyph.isValid = false;
+        m_lastGlyph = 0;
         return 0;
     }
 
     ASSERT(fontData->isCustomFont());
     ASSERT(fontData->isSVGFont());
 
     RefPtr<CustomFontData> customFontData = fontData->customFontData();
     const SVGFontData* svgFontData = static_cast<const SVGFontData*>(customFontData.get());
     SVGFontFaceElement* svgFontFace = svgFontData->svgFontFaceElement();
     ASSERT(svgFontFace);
 
     SVGFontElement* svgFont = svgFontFace->associatedFontElement();
     if (!svgFont) {
-        m_lastGlyph.isValid = false;
+        m_lastGlyph = 0;
         return 0;
     }
 
     float kerning = 0;
-    if (m_lastGlyph.isValid) {
+    if (m_lastGlyph) {
         if (isVerticalText)
-            kerning = svgFont->verticalKerningForPairOfStringsAndGlyphs(m_lastGlyph.unicodeString, m_lastGlyph.name, currentGlyph.unicodeString, currentGlyph.name);
+            kerning = svgFont->verticalKerningForPairOfGlyphs(m_lastGlyph, currentGlyph);
         else
-            kerning = svgFont->horizontalKerningForPairOfStringsAndGlyphs(m_lastGlyph.unicodeString, m_lastGlyph.name, currentGlyph.unicodeString, currentGlyph.name);
+            kerning = svgFont->horizontalKerningForPairOfGlyphs(m_lastGlyph, currentGlyph);
+
+        kerning *= m_font.fontDescription().computedSize() / m_font.fontMetrics().unitsPerEm();
     }
 
     m_lastGlyph = currentGlyph;
-    m_lastGlyph.isValid = true;
-    kerning *= m_font.fontDescription().computedSize() / m_font.fontMetrics().unitsPerEm();
     return kerning;
 #else
-    return false;
+    return 0;
 #endif
 }
 
 float SVGTextLayoutEngineSpacing::calculateCSSKerningAndSpacing(const SVGRenderStyle* style, SVGElement* contextElement, UChar currentCharacter)
 {
     float kerning = 0;
     RefPtr<SVGLength> kerningLength = style->kerning();
     if (kerningLength->unitType() == LengthTypePercentage)
         kerning = kerningLength->valueAsPercentage() * m_font.fontDescription().computedPixelSize();
     else {
@@ skipping 10 matching lines @@
     float spacing = m_font.fontDescription().letterSpacing() + kerning;
     if (currentCharacter && lastCharacter && m_font.fontDescription().wordSpacing()) {
         if (Character::treatAsSpace(currentCharacter) && !Character::treatAsSpace(lastCharacter))
             spacing += m_font.fontDescription().wordSpacing();
     }
 
     return spacing;
 }
 
 }