text: /*
   * Copyright (C) 2005, 2008, 2010 Apple Inc. All rights reserved.
   * Copyright (C) 2006 Alexey Proskuryakov
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1.  Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer. 
   * 2.  Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution. 
   * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
   *     its contributors may be used to endorse or promote products derived
   *     from this software without specific prior written permission. 
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "config.h"
  #include "SimpleFontData.h"
  
  #include "Font.h"
  #include "FontCache.h"
  
  #if ENABLE(SVG_FONTS)
  #include "SVGFontData.h"
  #include "SVGFontElement.h"
  #include "SVGFontFaceElement.h"
  #include "SVGGlyphElement.h"
  #endif
  
  #include <wtf/MathExtras.h>
  #include <wtf/UnusedParam.h>
  
  using namespace std;
  
  namespace WebCore {
  
  SimpleFontData::SimpleFontData(const FontPlatformData& platformData, bool isCustomFont, bool isLoading, bool isTextOrientationFallback)
      : m_maxCharWidth(-1)
      , m_avgCharWidth(-1)
      , m_platformData(platformData)
      , m_treatAsFixedPitch(false)
      , m_isCustomFont(isCustomFont)
      , m_isLoading(isLoading)
      , m_isTextOrientationFallback(isTextOrientationFallback)
      , m_isBrokenIdeographFallback(false)
      , m_hasVerticalGlyphs(false)
  {
      platformInit();
      platformGlyphInit();
      platformCharWidthInit();
  }
  
  #if ENABLE(SVG_FONTS)
  SimpleFontData::SimpleFontData(PassOwnPtr<SVGFontData> svgFontData, int size, bool syntheticBold, bool syntheticItalic)
      : m_platformData(FontPlatformData(size, syntheticBold, syntheticItalic))
      , m_treatAsFixedPitch(false)
      , m_svgFontData(svgFontData)
      , m_isCustomFont(true)
      , m_isLoading(false)
      , m_isTextOrientationFallback(false)
      , m_isBrokenIdeographFallback(false)
      , m_hasVerticalGlyphs(false)
  {
      SVGFontFaceElement* svgFontFaceElement = m_svgFontData->svgFontFaceElement();
      unsigned unitsPerEm = svgFontFaceElement->unitsPerEm();
  
      float scale = size;
      if (unitsPerEm)
          scale /= unitsPerEm;
  
      float xHeight = svgFontFaceElement->xHeight() * scale;
      float ascent = svgFontFaceElement->ascent() * scale;
      float descent = svgFontFaceElement->descent() * scale;
      float lineGap = 0.1f * size;
  
      SVGFontElement* associatedFontElement = svgFontFaceElement->associatedFontElement();
      if (!xHeight) {    
          // Fallback if x_heightAttr is not specified for the font element.
          Vector<SVGGlyphIdentifier> letterXGlyphs;
          associatedFontElement->getGlyphIdentifiersForString(String("x", 1), letterXGlyphs);
          xHeight = letterXGlyphs.isEmpty() ? 2 * ascent / 3 : letterXGlyphs.first().horizontalAdvanceX * scale;
      }
  
      m_fontMetrics.setUnitsPerEm(unitsPerEm);
      m_fontMetrics.setAscent(ascent);
      m_fontMetrics.setDescent(descent);
      m_fontMetrics.setLineGap(lineGap);
      m_fontMetrics.setLineSpacing(roundf(ascent) + roundf(descent) + roundf(lineGap));
      m_fontMetrics.setXHeight(xHeight);
  
      Vector<SVGGlyphIdentifier> spaceGlyphs;
      associatedFontElement->getGlyphIdentifiersForString(String(" ", 1), spaceGlyphs);
      m_spaceWidth = spaceGlyphs.isEmpty() ? xHeight : spaceGlyphs.first().horizontalAdvanceX * scale;
  
      Vector<SVGGlyphIdentifier> numeralZeroGlyphs;
      associatedFontElement->getGlyphIdentifiersForString(String("0", 1), numeralZeroGlyphs);
      m_avgCharWidth = numeralZeroGlyphs.isEmpty() ? m_spaceWidth : numeralZeroGlyphs.first().horizontalAdvanceX * scale;
  
      Vector<SVGGlyphIdentifier> letterWGlyphs;
      associatedFontElement->getGlyphIdentifiersForString(String("W", 1), letterWGlyphs);
      m_maxCharWidth = letterWGlyphs.isEmpty() ? ascent : letterWGlyphs.first().horizontalAdvanceX * scale;
  
      // FIXME: is there a way we can get the space glyph from the SVGGlyphIdentifier above?
      m_spaceGlyph = 0;
      m_zeroWidthSpaceGlyph = 0;
      determinePitch();
      m_missingGlyphData.fontData = this;
      m_missingGlyphData.glyph = 0;
  }
  #endif
  
  #if !PLATFORM(QT)
  // Estimates of avgCharWidth and maxCharWidth for platforms that don't support accessing these values from the font.
  void SimpleFontData::initCharWidths()
  {
      GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
  
      // Treat the width of a '0' as the avgCharWidth.
      if (m_avgCharWidth <= 0.f && glyphPageZero) {
          static const UChar32 digitZeroChar = '0';
          Glyph digitZeroGlyph = glyphPageZero->glyphDataForCharacter(digitZeroChar).glyph;
          if (digitZeroGlyph)
              m_avgCharWidth = widthForGlyph(digitZeroGlyph);
      }
  
      // If we can't retrieve the width of a '0', fall back to the x height.
      if (m_avgCharWidth <= 0.f)
          m_avgCharWidth = m_fontMetrics.xHeight();
  
      if (m_maxCharWidth <= 0.f)
          m_maxCharWidth = max(m_avgCharWidth, m_fontMetrics.floatAscent());
  }
  
  void SimpleFontData::platformGlyphInit()
  {
      GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
      if (!glyphPageZero) {
          LOG_ERROR("Failed to get glyph page zero.");
          m_spaceGlyph = 0;
          m_spaceWidth = 0;
          determinePitch();
          m_zeroWidthSpaceGlyph = 0;
          m_missingGlyphData.fontData = this;
          m_missingGlyphData.glyph = 0;
          return;
      }
  
      m_zeroWidthSpaceGlyph = glyphPageZero->glyphDataForCharacter(0).glyph;
  
      // Nasty hack to determine if we should round or ceil space widths.
      // If the font is monospace or fake monospace we ceil to ensure that 
      // every character and the space are the same width.  Otherwise we round.
      m_spaceGlyph = glyphPageZero->glyphDataForCharacter(' ').glyph;
      float width = widthForGlyph(m_spaceGlyph);
      m_spaceWidth = width;
      determinePitch();
  
      // Force the glyph for ZERO WIDTH SPACE to have zero width, unless it is shared with SPACE.
      // Helvetica is an example of a non-zero width ZERO WIDTH SPACE glyph.
      // See <http://bugs.webkit.org/show_bug.cgi?id=13178>
      // Ask for the glyph for 0 to avoid paging in ZERO WIDTH SPACE. Control characters, including 0,
      // are mapped to the ZERO WIDTH SPACE glyph.
      if (m_zeroWidthSpaceGlyph == m_spaceGlyph) {
          m_zeroWidthSpaceGlyph = 0;
          LOG_ERROR("Font maps SPACE and ZERO WIDTH SPACE to the same glyph. Glyph width will not be overridden.");
      }
  
      m_missingGlyphData.fontData = this;
      m_missingGlyphData.glyph = 0;
  }
  #endif
  
  SimpleFontData::~SimpleFontData()
  {
  #if ENABLE(SVG_FONTS)
      if (!m_svgFontData || !m_svgFontData->svgFontFaceElement())
  #endif
          platformDestroy();
  
      if (!isCustomFont())
          GlyphPageTreeNode::pruneTreeFontData(this);
  }
  
  const SimpleFontData* SimpleFontData::fontDataForCharacter(UChar32) const
  {
      return this;
  }
  
  bool SimpleFontData::isSegmented() const
  {
      return false;
  }
  
  SimpleFontData* SimpleFontData::verticalRightOrientationFontData() const
  {
      if (!m_derivedFontData)
          m_derivedFontData = DerivedFontData::create(isCustomFont());
      if (!m_derivedFontData->verticalRightOrientation) {
          FontPlatformData verticalRightPlatformData(m_platformData);
          verticalRightPlatformData.setOrientation(Horizontal);
          m_derivedFontData->verticalRightOrientation = new SimpleFontData(verticalRightPlatformData, isCustomFont(), false, true);
      }
      return m_derivedFontData->verticalRightOrientation.get();
  }
  
  SimpleFontData* SimpleFontData::uprightOrientationFontData() const
  {
      if (!m_derivedFontData)
          m_derivedFontData = DerivedFontData::create(isCustomFont());
      if (!m_derivedFontData->uprightOrientation)
          m_derivedFontData->uprightOrientation = new SimpleFontData(m_platformData, isCustomFont(), false, true);
      return m_derivedFontData->uprightOrientation.get();
  }
  
  SimpleFontData* SimpleFontData::brokenIdeographFontData() const
  {
      if (!m_derivedFontData)
          m_derivedFontData = DerivedFontData::create(isCustomFont());
      if (!m_derivedFontData->brokenIdeograph) {
          m_derivedFontData->brokenIdeograph = new SimpleFontData(m_platformData, isCustomFont(), false);
          m_derivedFontData->brokenIdeograph->m_isBrokenIdeographFallback = true;
      }
      return m_derivedFontData->brokenIdeograph.get();
  }
  
  #ifndef NDEBUG
  String SimpleFontData::description() const
  {
      if (isSVGFont())
          return "[SVG font]";
      if (isCustomFont())
          return "[custom font]";
  
      return platformData().description();
  }
  #endif
  
  PassOwnPtr<SimpleFontData::DerivedFontData> SimpleFontData::DerivedFontData::create(bool forCustomFont)
  {
      return adoptPtr(new DerivedFontData(forCustomFont));
  }
  
  SimpleFontData::DerivedFontData::~DerivedFontData()
  {
      if (!forCustomFont)
          return;
  
      if (smallCaps)
          GlyphPageTreeNode::pruneTreeCustomFontData(smallCaps.get());
      if (emphasisMark)
          GlyphPageTreeNode::pruneTreeCustomFontData(emphasisMark.get());
      if (brokenIdeograph)
          GlyphPageTreeNode::pruneTreeCustomFontData(brokenIdeograph.get());
      if (verticalRightOrientation)
          GlyphPageTreeNode::pruneTreeCustomFontData(verticalRightOrientation.get());
      if (uprightOrientation)
          GlyphPageTreeNode::pruneTreeCustomFontData(uprightOrientation.get());
  }
  
  } // namespace WebCore
  