AUD_SinusReader.cpp

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/*
 * $Id: AUD_SinusReader.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_SinusReader.h"

#include <cmath>

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

AUD_SinusReader::AUD_SinusReader(float frequency, AUD_SampleRate sampleRate) :
        m_frequency(frequency),
        m_position(0),
        m_sampleRate(sampleRate)
{
}

bool AUD_SinusReader::isSeekable() const
{
        return true;
}

void AUD_SinusReader::seek(int position)
{
        m_position = position;
}

int AUD_SinusReader::getLength() const
{
        return -1;
}

int AUD_SinusReader::getPosition() const
{
        return m_position;
}

AUD_Specs AUD_SinusReader::getSpecs() const
{
        AUD_Specs specs;
        specs.rate = m_sampleRate;
        specs.channels = AUD_CHANNELS_MONO;
        return specs;
}

void AUD_SinusReader::read(int & length, sample_t* & buffer)
{
        // resize if necessary
        if(m_buffer.getSize() < length * sizeof(sample_t))
                m_buffer.resize(length * sizeof(sample_t));

        // fill with sine data
        buffer = m_buffer.getBuffer();
        for(int i = 0; i < length; i++)
        {
                buffer[i] = sin((m_position + i) * 2 * M_PI * m_frequency /
                                                (float)m_sampleRate);
        }

        m_position += length;
}