JUCE/modules/juce_audio_basics/sources/juce_ChannelRemappingAudioSource.cpp

/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

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   Or:

   You may also use this code under the terms of the AGPLv3:
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  ==============================================================================
*/

namespace juce
{

ChannelRemappingAudioSource::ChannelRemappingAudioSource (AudioSource* const source_,
                                                          const bool deleteSourceWhenDeleted)
   : source (source_, deleteSourceWhenDeleted),
     requiredNumberOfChannels (2)
{
    remappedInfo.buffer = &buffer;
    remappedInfo.startSample = 0;
}

ChannelRemappingAudioSource::~ChannelRemappingAudioSource() {}

//==============================================================================
void ChannelRemappingAudioSource::setNumberOfChannelsToProduce (const int requiredNumberOfChannels_)
{
    const ScopedLock sl (lock);
    requiredNumberOfChannels = requiredNumberOfChannels_;
}

void ChannelRemappingAudioSource::clearAllMappings()
{
    const ScopedLock sl (lock);

    remappedInputs.clear();
    remappedOutputs.clear();
}

void ChannelRemappingAudioSource::setInputChannelMapping (const int destIndex, const int sourceIndex)
{
    const ScopedLock sl (lock);

    while (remappedInputs.size() < destIndex)
        remappedInputs.add (-1);

    remappedInputs.set (destIndex, sourceIndex);
}

void ChannelRemappingAudioSource::setOutputChannelMapping (const int sourceIndex, const int destIndex)
{
    const ScopedLock sl (lock);

    while (remappedOutputs.size() < sourceIndex)
        remappedOutputs.add (-1);

    remappedOutputs.set (sourceIndex, destIndex);
}

int ChannelRemappingAudioSource::getRemappedInputChannel (const int inputChannelIndex) const
{
    const ScopedLock sl (lock);

    if (inputChannelIndex >= 0 && inputChannelIndex < remappedInputs.size())
        return remappedInputs.getUnchecked (inputChannelIndex);

    return -1;
}

int ChannelRemappingAudioSource::getRemappedOutputChannel (const int outputChannelIndex) const
{
    const ScopedLock sl (lock);

    if (outputChannelIndex >= 0 && outputChannelIndex < remappedOutputs.size())
        return remappedOutputs .getUnchecked (outputChannelIndex);

    return -1;
}

//==============================================================================
void ChannelRemappingAudioSource::prepareToPlay (int samplesPerBlockExpected, double sampleRate)
{
    source->prepareToPlay (samplesPerBlockExpected, sampleRate);
}

void ChannelRemappingAudioSource::releaseResources()
{
    source->releaseResources();
}

void ChannelRemappingAudioSource::getNextAudioBlock (const AudioSourceChannelInfo& bufferToFill)
{
    const ScopedLock sl (lock);

    buffer.setSize (requiredNumberOfChannels, bufferToFill.numSamples, false, false, true);

    const int numChans = bufferToFill.buffer->getNumChannels();

    for (int i = 0; i < buffer.getNumChannels(); ++i)
    {
        const int remappedChan = getRemappedInputChannel (i);

        if (remappedChan >= 0 && remappedChan < numChans)
        {
            buffer.copyFrom (i, 0, *bufferToFill.buffer,
                             remappedChan,
                             bufferToFill.startSample,
                             bufferToFill.numSamples);
        }
        else
        {
            buffer.clear (i, 0, bufferToFill.numSamples);
        }
    }

    remappedInfo.numSamples = bufferToFill.numSamples;

    source->getNextAudioBlock (remappedInfo);

    bufferToFill.clearActiveBufferRegion();

    for (int i = 0; i < requiredNumberOfChannels; ++i)
    {
        const int remappedChan = getRemappedOutputChannel (i);

        if (remappedChan >= 0 && remappedChan < numChans)
        {
            bufferToFill.buffer->addFrom (remappedChan, bufferToFill.startSample,
                                          buffer, i, 0, bufferToFill.numSamples);

        }
    }
}

//==============================================================================
std::unique_ptr<XmlElement> ChannelRemappingAudioSource::createXml() const
{
    auto e = std::make_unique<XmlElement> ("MAPPINGS");
    String ins, outs;

    const ScopedLock sl (lock);

    for (int i = 0; i < remappedInputs.size(); ++i)
        ins << remappedInputs.getUnchecked (i) << ' ';

    for (int i = 0; i < remappedOutputs.size(); ++i)
        outs << remappedOutputs.getUnchecked (i) << ' ';

    e->setAttribute ("inputs", ins.trimEnd());
    e->setAttribute ("outputs", outs.trimEnd());

    return e;
}

void ChannelRemappingAudioSource::restoreFromXml (const XmlElement& e)
{
    if (e.hasTagName ("MAPPINGS"))
    {
        const ScopedLock sl (lock);

        clearAllMappings();

        StringArray ins, outs;
        ins.addTokens (e.getStringAttribute ("inputs"), false);
        outs.addTokens (e.getStringAttribute ("outputs"), false);

        for (int i = 0; i < ins.size(); ++i)
            remappedInputs.add (ins[i].getIntValue());

        for (int i = 0; i < outs.size(); ++i)
            remappedOutputs.add (outs[i].getIntValue());
    }
}

} // namespace juce