/***************************************************************************
                  Mul.h  -  multiplier
                             -------------------
    begin                : Thu Nov 01 2007
    copyright            : (C) 2007 by Thomas Eschenbacher
    email                : Thomas.Eschenbacher@gmx.de
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef MUL_H
#define MUL_H

#include "config.h"

#include <QtGlobal>
#include <QMutex>
#include <QQueue>
#include <QSemaphore>

#include "libkwave/SampleArray.h"
#include "libkwave/SampleSink.h"
#include "libkwave/SampleSource.h"

class QVariant;

namespace Kwave
{

    class Q_DECL_EXPORT Mul: public Kwave::SampleSource
    {
	Q_OBJECT
	public:
	    /** Constructor */
	    Mul();

	    /** Destructor */
	    virtual ~Mul();

	    /** does nothing, work is done automatically in multiply() */
	    virtual void goOn();

	signals:
	    /** emits a block with the interpolated curve */
	    void output(Kwave::SampleArray data);

	public slots:

	    /** receives input data for input A */
	    void input_a(Kwave::SampleArray data);

	    /** receives input data for input B */
	    void input_b(Kwave::SampleArray data);

	    /** sets input A to a constant value (as float) */
	    void set_a(const QVariant &a);

	    /** sets input B to a constant value (as float) */
	    void set_b(const QVariant &b);

	private:

	    /** does the calculation */
	    virtual void multiply();

	private:

	    /** queue for input A */
	    QQueue<Kwave::SampleArray> m_queue_a;

	    /** queue for input B */
	    QQueue<Kwave::SampleArray> m_queue_b;

	    /** semaphore to wait for input on input A */
	    QSemaphore m_sem_a;

	    /** semaphore to wait for input on input B */
	    QSemaphore m_sem_b;

	    /** buffer for input A (currently in work) */
	    Kwave::SampleArray m_a;

	    /** buffer for input B (currently in work) */
	    Kwave::SampleArray m_b;

	    /** buffer for output data */
	    Kwave::SampleArray m_buffer_x;

	    /** if true, input A is a constant */
	    bool m_a_is_const;

	    /** if true, input B is a constant */
	    bool m_b_is_const;

	    /** if m_a_is_const is set, the value of A */
	    float m_value_a;

	    /** if m_b_is_const is set, the value of B */
	    float m_value_b;

	    /** mutex for locking access to the queues */
	    QMutex m_lock;
    };
}

#endif /* MUL_H */

/***************************************************************************/
/***************************************************************************/
