AUD_BaseIIRFilterReader.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_BaseIIRFilterReader.h"

#include <cstring>

#define CC m_specs.channels + m_channel

AUD_BaseIIRFilterReader::AUD_BaseIIRFilterReader(AUD_Reference<AUD_IReader> reader, int in,
                                                 int out) :
        AUD_EffectReader(reader),
        m_specs(reader->getSpecs()),
        m_xlen(in), m_ylen(out),
        m_xpos(0), m_ypos(0), m_channel(0)
{
    m_x = new sample_t[m_xlen * m_specs.channels];
    m_y = new sample_t[m_ylen * m_specs.channels];

    memset(m_x, 0, sizeof(sample_t) * m_xlen * m_specs.channels);
    memset(m_y, 0, sizeof(sample_t) * m_ylen * m_specs.channels);
}

AUD_BaseIIRFilterReader::~AUD_BaseIIRFilterReader()
{
    delete[] m_x;
    delete[] m_y;
}

void AUD_BaseIIRFilterReader::setLengths(int in, int out)
{
    if(in != m_xlen)
    {
        sample_t* xn = new sample_t[in * m_specs.channels];
        memset(xn, 0, sizeof(sample_t) * in * m_specs.channels);

        for(m_channel = 0; m_channel < m_specs.channels; m_channel++)
        {
            for(int i = 1; i <= in && i <= m_xlen; i++)
            {
                xn[(in - i) * CC] = x(-i);
            }
        }

        delete[] m_x;
        m_x = xn;
        m_xpos = 0;
        m_xlen = in;
    }

    if(out != m_ylen)
    {
        sample_t* yn = new sample_t[out * m_specs.channels];
        memset(yn, 0, sizeof(sample_t) * out * m_specs.channels);

        for(m_channel = 0; m_channel < m_specs.channels; m_channel++)
        {
            for(int i = 1; i <= out && i <= m_ylen; i++)
            {
                yn[(out - i) * CC] = y(-i);
            }
        }

        delete[] m_y;
        m_y = yn;
        m_ypos = 0;
        m_ylen = out;
    }
}

void AUD_BaseIIRFilterReader::read(int& length, bool& eos, sample_t* buffer)
{
    AUD_Specs specs = m_reader->getSpecs();
    if(specs.channels != m_specs.channels)
    {
        m_specs.channels = specs.channels;

        delete[] m_x;
        delete[] m_y;

        m_x = new sample_t[m_xlen * m_specs.channels];
        m_y = new sample_t[m_ylen * m_specs.channels];

        memset(m_x, 0, sizeof(sample_t) * m_xlen * m_specs.channels);
        memset(m_y, 0, sizeof(sample_t) * m_ylen * m_specs.channels);
    }

    if(specs.rate != m_specs.rate)
    {
        m_specs = specs;
        sampleRateChanged(m_specs.rate);
    }

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

    for(m_channel = 0; m_channel < m_specs.channels; m_channel++)
    {
        for(int i = 0; i < length; i++)
        {
            m_x[m_xpos * CC] = buffer[i * CC];
            m_y[m_ypos * CC] = buffer[i * CC] = filter();

            m_xpos = (m_xpos + 1) % m_xlen;
            m_ypos = (m_ypos + 1) % m_ylen;
        }
    }
}

void AUD_BaseIIRFilterReader::sampleRateChanged(AUD_SampleRate rate)
{
}