AUD_LoopReader.cpp

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/*
 * $Id: AUD_LoopReader.cpp 35141 2011-02-25 10:21:56Z jesterking $
 *
 * ***** 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_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, sample_t* & buffer)
{
        AUD_Specs specs = m_reader->getSpecs();
        int samplesize = AUD_SAMPLE_SIZE(specs);

        int len = length;

        m_reader->read(len, buffer);

        if(len < length && m_left)
        {
                int pos = 0;

                if(m_buffer.getSize() < length * samplesize)
                        m_buffer.resize(length * samplesize);

                sample_t* buf = m_buffer.getBuffer();

                memcpy(buf + pos * specs.channels, buffer, len * samplesize);

                pos += len;

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

                        m_reader->seek(0);

                        len = length - pos;
                        m_reader->read(len, buffer);

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

                        memcpy(buf + pos * specs.channels, buffer, len * samplesize);

                        pos += len;
                }

                length = pos;
                buffer = buf;
        }
        else
                length = len;
}