text: #ifndef STK_FILEWVIN_H
  #define STK_FILEWVIN_H
  
  #include "WvIn.h"
  #include "FileRead.h"
  
  namespace stk {
  
  /***************************************************/
  /*! \class FileWvIn
      \brief STK audio file input class.
  
      This class inherits from WvIn.  It provides a "tick-level"
      interface to the FileRead class.  It also provides variable-rate
      playback functionality.  Audio file support is provided by the
      FileRead class.  Linear interpolation is used for fractional read
      rates.
  
      FileWvIn supports multi-channel data.  It is important to
      distinguish the tick() method that computes a single frame (and
      returns only the specified sample of a multi-channel frame) from
      the overloaded one that takes an StkFrames object for
      multi-channel and/or multi-frame data.
  
      FileWvIn will either load the entire content of an audio file into
      local memory or incrementally read file data from disk in chunks.
      This behavior is controlled by the optional constructor arguments
      \e chunkThreshold and \e chunkSize.  File sizes greater than \e
      chunkThreshold (in sample frames) will be read incrementally in
      chunks of \e chunkSize each (also in sample frames).
  
      When the file end is reached, subsequent calls to the tick()
      functions return zeros and isFinished() returns \e true.
  
      See the FileRead class for a description of the supported audio
      file formats.
  
      by Perry R. Cook and Gary P. Scavone, 1995--2016.
  */
  /***************************************************/
  
  class FileWvIn : public WvIn
  {
  public:
    //! Default constructor.
    FileWvIn( unsigned long chunkThreshold = 1000000, unsigned long chunkSize = 1024 );
  
    //! Overloaded constructor for file input.
    /*!
      An StkError will be thrown if the file is not found, its format is
      unknown, or a read error occurs.
    */
    FileWvIn( std::string fileName, bool raw = false, bool doNormalize = true,
              unsigned long chunkThreshold = 1000000, unsigned long chunkSize = 1024 );
  
    //! Class destructor.
    ~FileWvIn( void );
  
    //! Open the specified file and load its data.
    /*!
      Data from a previously opened file will be overwritten by this
      function.  An StkError will be thrown if the file is not found,
      its format is unknown, or a read error occurs.  If the file data
      is to be loaded incrementally from disk and normalization is
      specified, a scaling will be applied with respect to fixed-point
      limits.  If the data format is floating-point, no scaling is
      performed.
    */
    virtual void openFile( std::string fileName, bool raw = false, bool doNormalize = true );
  
    //! Close a file if one is open.
    virtual void closeFile( void );
  
    //! Clear outputs and reset time (file) pointer to zero.
    virtual void reset( void );
  
    //! Normalize data to a maximum of +-1.0.
    /*!
      This function has no effect when data is incrementally loaded
      from disk.
    */
    virtual void normalize( void );
  
    //! Normalize data to a maximum of \e +-peak.
    /*!
      This function has no effect when data is incrementally loaded
      from disk.
    */
    virtual void normalize( StkFloat peak );
  
    //! Return the file size in sample frames.
    virtual unsigned long getSize( void ) const { return fileSize_; };
  
    //! Return the input file sample rate in Hz (not the data read rate).
    /*!
      WAV, SND, and AIF formatted files specify a sample rate in
      their headers.  STK RAW files have a sample rate of 22050 Hz
      by definition.  MAT-files are assumed to have a rate of 44100 Hz.
    */
    virtual StkFloat getFileRate( void ) const { return data_.dataRate(); };
  
    //! Query whether a file is open.
    bool isOpen( void ) { return file_.isOpen(); };
  
    //! Query whether reading is complete.
    bool isFinished( void ) const { return finished_; };
  
    //! Set the data read rate in samples.  The rate can be negative.
    /*!
      If the rate value is negative, the data is read in reverse order.
    */
    virtual void setRate( StkFloat rate );
  
    //! Increment the read pointer by \e time samples.
    /*!
      Note that this function will not modify the interpolation flag status.
     */
    virtual void addTime( StkFloat time );
  
    //! Turn linear interpolation on/off.
    /*!
      Interpolation is automatically off when the read rate is
      an integer value.  If interpolation is turned off for a
      fractional rate, the time index is truncated to an integer
      value.
    */
    void setInterpolate( bool doInterpolate ) { interpolate_ = doInterpolate; };
  
    //! Return the specified channel value of the last computed frame.
    /*!
      If no file is loaded, the returned value is 0.0.  The \c
      channel argument must be less than the number of output channels,
      which can be determined with the channelsOut() function (the first
      channel is specified by 0).  However, range checking is only
      performed if _STK_DEBUG_ is defined during compilation, in which
      case an out-of-range value will trigger an StkError exception. \sa
      lastFrame()
    */
    StkFloat lastOut( unsigned int channel = 0 );
  
    //! Compute a sample frame and return the specified \c channel value.
    /*!
      For multi-channel files, use the lastFrame() function to get
      all values from the computed frame.  If no file data is loaded,
      the returned value is 0.0.  The \c channel argument must be less
      than the number of channels in the file data (the first channel is
      specified by 0).  However, range checking is only performed if
      _STK_DEBUG_ is defined during compilation, in which case an
      out-of-range value will trigger an StkError exception.
    */
    virtual StkFloat tick( unsigned int channel = 0 );
  
    //! Fill the StkFrames object with computed sample frames, starting at the specified channel and return the same reference.
    /*!
      The \c channel argument plus the number of input channels must
      be less than the number of channels in the StkFrames argument (the
      first channel is specified by 0).  However, range checking is only
      performed if _STK_DEBUG_ is defined during compilation, in which
      case an out-of-range value will trigger an StkError exception.
    */
    virtual StkFrames& tick( StkFrames& frames,unsigned int channel = 0 );
  
  protected:
  
    void sampleRateChanged( StkFloat newRate, StkFloat oldRate );
  
    FileRead file_;
    bool finished_;
    bool interpolate_;
    bool normalizing_;
    bool chunking_;
    StkFloat time_;
    StkFloat rate_;
    unsigned long fileSize_;
    unsigned long chunkThreshold_;
    unsigned long chunkSize_;
    long chunkPointer_;
  
  };
  
  inline StkFloat FileWvIn :: lastOut( unsigned int channel )
  {
  #if defined(_STK_DEBUG_)
    if ( channel >= data_.channels() ) {
      oStream_ << "FileWvIn::lastOut(): channel argument and soundfile data are incompatible!";
      handleError( StkError::FUNCTION_ARGUMENT );
    }
  #endif
  
    if ( finished_ ) return 0.0;
    return lastFrame_[channel];
  }
  
  } // stk namespace
  
  #endif
  