AUD_LoopReader.cpp

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * Copyright 2009-2011 Jörg Hermann Müller
 *
 * This file is part of AudaSpace.
 *
 * Audaspace 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.
 *
 * AudaSpace 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 Audaspace; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "AUD_LoopReader.h"
#include "AUD_Buffer.h"

#include <cstring>

AUD_LoopReader::AUD_LoopReader(AUD_Reference<AUD_IReader> reader, int loop) :
        AUD_EffectReader(reader), m_count(loop), m_left(loop)
{
}

void AUD_LoopReader::seek(int position)
{
    int len = m_reader->getLength();
    if(len < 0)
        m_reader->seek(position);
    else
    {
        if(m_count >= 0)
        {
            m_left = m_count - (position / len);
            if(m_left < 0)
                m_left = 0;
        }
        m_reader->seek(position % len);
    }
}

int AUD_LoopReader::getLength() const
{
    if(m_count < 0)
        return -1;
    return m_reader->getLength() * m_count;
}

int AUD_LoopReader::getPosition() const
{
    return m_reader->getPosition() * (m_count < 0 ? 1 : m_count);
}

void AUD_LoopReader::read(int& length, bool& eos, sample_t* buffer)
{
    const AUD_Specs specs = m_reader->getSpecs();

    int len = length;

    m_reader->read(length, eos, buffer);

    if(length < len && eos && m_left)
    {
        int pos = length;
        length = len;

        while(pos < length && eos && m_left)
        {
            if(m_left > 0)
                m_left--;

            m_reader->seek(0);

            len = length - pos;
            m_reader->read(len, eos, buffer + pos * specs.channels);

            // prevent endless loop
            if(!len)
                break;

            pos += len;
        }

        length = pos;
    }
}