/*****************************************************************************
 *
 * 'FIFOSamplePipe' : An abstract base class for classes that manipulate sound
 * samples by operating like a first-in-first-out pipe: New samples are fed
 * into one end of the pipe with the 'putSamples' function, and the processed
 * samples are received from the other end with the 'receiveSamples' function.
 *
 * 'FIFOProcessor' : A base class for classes the do signal processing with 
 * the samples while operating like a first-in-first-out pipe. When samples
 * are inputted with the 'putSamples' function, the class processes them
 * and moves the processed samples to the given 'output' pipe object, which
 * may be either another processing stage, or a fifo sample buffer object.
 *
 * Author        : Copyright (c) Olli Parviainen
 * Author e-mail : oparviai @ iki.fi
 * File created  : 13-Jan-2002
 *
 * Last changed  : $Date: 2003/10/13 00:35:13 $
 * File revision : $Revision: 1.1 $
 *
 * $Id: FIFOSamplePipe.h,v 1.1 2003/10/13 00:35:13 melanie_t Exp $
 *
 * License :
 * 
 *  SoundTouch sound processing library
 *  Copyright (c) Olli Parviainen
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 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
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *****************************************************************************/

#ifndef FIFOSamplePipe_H
#define FIFOSamplePipe_H

#include <assert.h>
#include <stdlib.h>

/// Abstract base class for FIFO (first-in-first-out) sample processing classes.
class FIFOSamplePipe
{
public:
    /// Returns a pointer to the beginning of the output samples. 
    /// This function is provided for accessing the output samples directly. 
    /// Please be careful for not to corrupt the book-keeping!
    ///
    /// When using this function to output samples, also remember to 'remove' the
    /// outputted samples from the buffer by calling the 
    /// 'receiveSamples(numSamples)' function
    virtual short *ptrBegin() const = 0;

    /// Adds 'numSamples' pcs of samples from the 'samples' memory position to
    /// the sample buffer.
    virtual void putSamples(const short *samples,   ///< Pointer to samples.
                            const uint numSamples   ///< Number of samples to insert.
                            ) = 0;


    // Moves samples from the 'other' pipe instance to this instance.
    void moveSamples(FIFOSamplePipe &other  ///< Other pipe instance where from the receive the data.
         )
    {
        int oNumSamples = other.numSamples();

        putSamples(other.ptrBegin(), oNumSamples);
        other.receiveSamples(oNumSamples);
    };

    /// Output samples from beginning of the sample buffer. Copies requested samples to 
    /// output buffer and removes them from the sample buffer. If there are less than 
    /// 'numsample' samples in the buffer, returns all that available.
    ///
    /// \return Number of samples returned.
    virtual uint receiveSamples(short *output,          ///< Buffer where to copy output samples.
                                const uint maxSamples   ///< How many samples to receive at max.
                                ) = 0;

    /// Adjusts book-keeping so that given number of samples are removed from beginning of the 
    /// sample buffer without copying them anywhere. 
    ///
    /// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
    /// with 'ptrBegin' function.
    virtual uint receiveSamples(const uint maxSamples   ///< Remove this many samples from the beginning of pipe.
                                ) = 0;

    /// Returns number of samples currently available.
    virtual uint numSamples() const = 0;

    // Returns nonzero if there aren't any samples available for outputting.
    virtual int isEmpty() const = 0;

    /// Clears all the samples.
    virtual void clear() = 0;
};



/// Base-class for sound processing routines working in FIFO principle. With this base 
/// class it's easy to implement sound processing stages that can be chained together,
/// so that samples that are fed into beginning of the pipe automatically go through 
/// all the processing stages.
///
/// When samples are inputted to this class, they're first processed and then put to 
/// the FIFO pipe that's defined as output of this class. This output pipe can be
/// either other processing stage or a FIFO sample buffer.
class FIFOProcessor :public FIFOSamplePipe
{
protected:
    /// Internal pipe where processed samples are put.
    FIFOSamplePipe *output;

    /// Sets output pipe.
    void setOutPipe(FIFOSamplePipe *pOutput)
    {
        assert(output == NULL);
        assert(pOutput != NULL);
        output = pOutput;
    }


    /// Constructor. Doesn't define output pipe; it has to be set be 
    /// 'setOutPipe' function.
    FIFOProcessor()
    {
        output = NULL;
    }


    /// Constructor. Configures output pipe.
    FIFOProcessor(FIFOSamplePipe *pOutput   ///< Output pipe.
                 )
    {
        output = pOutput;
    }


    /// Destructor.
    virtual ~FIFOProcessor()
    {
    }


    /// Returns a pointer to the beginning of the output samples. 
    /// This function is provided for accessing the output samples directly. 
    /// Please be careful for not to corrupt the book-keeping!
    ///
    /// When using this function to output samples, also remember to 'remove' the
    /// outputted samples from the buffer by calling the 
    /// 'receiveSamples(numSamples)' function
    virtual short *ptrBegin() const
    {
        return output->ptrBegin();
    }

public:

    /// Output samples from beginning of the sample buffer. Copies requested samples to 
    /// output buffer and removes them from the sample buffer. If there are less than 
    /// 'numsample' samples in the buffer, returns all that available.
    ///
    /// \return Number of samples returned.
    virtual uint receiveSamples(short *outBuffer,       ///< Buffer where to copy output samples.
                                const uint maxSamples   ///< How many samples to receive at max.
                                )
    {
        return output->receiveSamples(outBuffer, maxSamples);
    }


    /// Adjusts book-keeping so that given number of samples are removed from beginning of the 
    /// sample buffer without copying them anywhere. 
    ///
    /// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
    /// with 'ptrBegin' function.
    virtual uint receiveSamples(const uint maxSamples   ///< Remove this many samples from the beginning of pipe.
                                )
    {
        return output->receiveSamples(maxSamples);
    }


    /// Returns number of samples currently available.
    virtual uint numSamples() const
    {
        return output->numSamples();
    }


    // Returns nonzero if there aren't any samples available for outputting.
    virtual int isEmpty() const
    {
        return output->isEmpty();
    }
};

#endif