AUD_Mixer.cpp

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/*
 * $Id: AUD_Mixer.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_Mixer.h"
#include "AUD_IReader.h"

#include <cstring>

AUD_Mixer::AUD_Mixer(AUD_DeviceSpecs specs) :
        m_specs(specs)
{
        int bigendian = 1;
        bigendian = (((char*)&bigendian)[0]) ? 0: 1; // 1 if Big Endian

        switch(m_specs.format)
        {
        case AUD_FORMAT_U8:
                m_convert = AUD_convert_float_u8;
                break;
        case AUD_FORMAT_S16:
                m_convert = AUD_convert_float_s16;
                break;
        case AUD_FORMAT_S24:
                if(bigendian)
                        m_convert = AUD_convert_float_s24_be;
                else
                        m_convert = AUD_convert_float_s24_le;
                break;
        case AUD_FORMAT_S32:
                m_convert = AUD_convert_float_s32;
                break;
        case AUD_FORMAT_FLOAT32:
                m_convert = AUD_convert_copy<float>;
                break;
        case AUD_FORMAT_FLOAT64:
                m_convert = AUD_convert_float_double;
                break;
        default:
                break;
        }
}

AUD_DeviceSpecs AUD_Mixer::getSpecs() const
{
        return m_specs;
}

void AUD_Mixer::add(sample_t* buffer, int start, int length, float volume)
{
        AUD_MixerBuffer buf;
        buf.buffer = buffer;
        buf.start = start;
        buf.length = length;
        buf.volume = volume;
        m_buffers.push_back(buf);
}

void AUD_Mixer::superpose(data_t* buffer, int length, float volume)
{
        AUD_MixerBuffer buf;

        int channels = m_specs.channels;

        if(m_buffer.getSize() < length * channels * 4)
                m_buffer.resize(length * channels * 4);

        sample_t* out = m_buffer.getBuffer();
        sample_t* in;

        memset(out, 0, length * channels * 4);

        int end;

        while(!m_buffers.empty())
        {
                buf = m_buffers.front();
                m_buffers.pop_front();

                end = buf.length * channels;
                in = buf.buffer;

                for(int i = 0; i < end; i++)
                        out[i + buf.start * channels] += in[i] * buf.volume * volume;
        }

        m_convert(buffer, (data_t*) out, length * channels);
}