RingBuffer.h

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/*
 * RingBuffer.h - an effective and flexible implementation of a ringbuffer for LMMS
 *
 * Copyright (c) 2014 Vesa Kivimäki
 * Copyright (c) 2005-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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.
 *
 * This program 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */
 
#ifndef LMMS_RING_BUFFER_H
#define LMMS_RING_BUFFER_H
 
#include <cmath>
#include <QObject>
#include "LmmsTypes.h"
#include "lmms_export.h"
 
 
namespace lmms
{
 
class SampleFrame;

class LMMS_EXPORT RingBuffer : public QObject
{
        Q_OBJECT
public:
        RingBuffer( f_cnt_t size );

        RingBuffer( float size );
        ~RingBuffer() override;
 
 
 

//       Provided functions       //
 
// utility functions

        void reset();

        void changeSize( f_cnt_t size );

        void changeSize( float size );

        void setSamplerateAware( bool b );
 
 
// position adjustment functions

        void advance();

        void movePosition( f_cnt_t amount );

        void movePosition( float amount );
 
 
// read functions

        void pop( SampleFrame* dst );
 
// note: ringbuffer position is unaffected by all other read functions beside pop()

        void read( SampleFrame* dst, f_cnt_t offset = 0 );

        void read( SampleFrame* dst, float offset );

        void read( SampleFrame* dst, f_cnt_t offset, f_cnt_t length );

        void read( SampleFrame* dst, float offset, f_cnt_t length );
 
 
// write functions

        void write( SampleFrame* src, f_cnt_t offset=0, f_cnt_t length=0 );

        void write( SampleFrame* src, float offset, f_cnt_t length=0 );

        void writeAdding( SampleFrame* src, f_cnt_t offset=0, f_cnt_t length=0 );

        void writeAdding( SampleFrame* src, float offset, f_cnt_t length=0 );

        void writeAddingMultiplied( SampleFrame* src, f_cnt_t offset, f_cnt_t length, float level );

        void writeAddingMultiplied( SampleFrame* src, float offset, f_cnt_t length, float level );

        void writeSwappedAddingMultiplied( SampleFrame* src, f_cnt_t offset, f_cnt_t length, float level );

        void writeSwappedAddingMultiplied( SampleFrame* src, float offset, f_cnt_t length, float level );
 
 
protected slots:
        void updateSamplerate();
 
private:
        inline f_cnt_t msToFrames( float ms )
        {
                return static_cast<f_cnt_t>( ceilf( ms * (float)m_samplerate * 0.001f ) );
        }
 
        const f_cnt_t m_fpp;
        sample_rate_t m_samplerate;
        size_t m_size;
        SampleFrame* m_buffer;
        volatile unsigned int m_position;
 
};
 
 
} // namespace lmms
 
#endif // LMMS_RING_BUFFER_H