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  ** Copyright (C) 2016 The Qt Company Ltd.
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  ** This file is part of the QtQuick module of the Qt Toolkit.
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  #ifndef QSGDISTANCEFIELDUTIL_H
  #define QSGDISTANCEFIELDUTIL_H
  
  //
  //  W A R N I N G
  //  -------------
  //
  // This file is not part of the Qt API.  It exists purely as an
  // implementation detail.  This header file may change from version to
  // version without notice, or even be removed.
  //
  // We mean it.
  //
  
  #include <qrawfont.h>
  #include <private/qfontengine_p.h>
  #include <private/qsgadaptationlayer_p.h>
  
  QT_BEGIN_NAMESPACE
  
  typedef float (*ThresholdFunc)(float glyphScale);
  typedef float (*AntialiasingSpreadFunc)(float glyphScale);
  
  class QOpenGLShaderProgram;
  class QSGDistanceFieldGlyphCache;
  class QSGContext;
  
  class Q_QUICK_PRIVATE_EXPORT QSGDistanceFieldGlyphCacheManager
  {
  public:
      QSGDistanceFieldGlyphCacheManager();
      ~QSGDistanceFieldGlyphCacheManager();
  
      QSGDistanceFieldGlyphCache *cache(const QRawFont &font);
      void insertCache(const QRawFont &font, QSGDistanceFieldGlyphCache *cache);
  
      ThresholdFunc thresholdFunc() const { return m_threshold_func; }
      void setThresholdFunc(ThresholdFunc func) { m_threshold_func = func; }
  
      AntialiasingSpreadFunc antialiasingSpreadFunc() const { return m_antialiasingSpread_func; }
      void setAntialiasingSpreadFunc(AntialiasingSpreadFunc func) { m_antialiasingSpread_func = func; }
  
  private:
      static QString fontKey(const QRawFont &font);
  
      QHash<QString, QSGDistanceFieldGlyphCache *> m_caches;
  
      ThresholdFunc m_threshold_func;
      AntialiasingSpreadFunc m_antialiasingSpread_func;
  };
  
  QT_END_NAMESPACE
  
  #endif // QSGDISTANCEFIELDUTIL_H
  