JUCE/modules/juce_audio_utils/players/juce_AudioProcessorPlayer.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

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

namespace juce
{

AudioProcessorPlayer::AudioProcessorPlayer (bool doDoublePrecisionProcessing)
    : isDoublePrecision (doDoublePrecisionProcessing)
{
}

AudioProcessorPlayer::~AudioProcessorPlayer()
{
    setProcessor (nullptr);
}

//==============================================================================
void AudioProcessorPlayer::setProcessor (AudioProcessor* const processorToPlay)
{
    if (processor != processorToPlay)
    {
        if (processorToPlay != nullptr && sampleRate > 0 && blockSize > 0)
        {
            processorToPlay->setPlayConfigDetails (numInputChans, numOutputChans, sampleRate, blockSize);

            bool supportsDouble = processorToPlay->supportsDoublePrecisionProcessing() && isDoublePrecision;

            processorToPlay->setProcessingPrecision (supportsDouble ? AudioProcessor::doublePrecision
                                                                    : AudioProcessor::singlePrecision);
            processorToPlay->prepareToPlay (sampleRate, blockSize);
        }

        AudioProcessor* oldOne;

        {
            const ScopedLock sl (lock);
            oldOne = isPrepared ? processor : nullptr;
            processor = processorToPlay;
            isPrepared = true;
        }

        if (oldOne != nullptr)
            oldOne->releaseResources();
    }
}

void AudioProcessorPlayer::setDoublePrecisionProcessing (bool doublePrecision)
{
    if (doublePrecision != isDoublePrecision)
    {
        const ScopedLock sl (lock);

        if (processor != nullptr)
        {
            processor->releaseResources();

            bool supportsDouble = processor->supportsDoublePrecisionProcessing() && doublePrecision;

            processor->setProcessingPrecision (supportsDouble ? AudioProcessor::doublePrecision
                                                              : AudioProcessor::singlePrecision);
            processor->prepareToPlay (sampleRate, blockSize);
        }

        isDoublePrecision = doublePrecision;
    }
}

void AudioProcessorPlayer::setMidiOutput (MidiOutput* midiOutputToUse)
{
    if (midiOutput != midiOutputToUse)
    {
        const ScopedLock sl (lock);
        midiOutput = midiOutputToUse;
    }
}

//==============================================================================
void AudioProcessorPlayer::audioDeviceIOCallback (const float** const inputChannelData,
                                                  const int numInputChannels,
                                                  float** const outputChannelData,
                                                  const int numOutputChannels,
                                                  const int numSamples)
{
    // these should have been prepared by audioDeviceAboutToStart()...
    jassert (sampleRate > 0 && blockSize > 0);

    incomingMidi.clear();
    messageCollector.removeNextBlockOfMessages (incomingMidi, numSamples);
    int totalNumChans = 0;

    if (numInputChannels > numOutputChannels)
    {
        // if there aren't enough output channels for the number of
        // inputs, we need to create some temporary extra ones (can't
        // use the input data in case it gets written to)
        tempBuffer.setSize (numInputChannels - numOutputChannels, numSamples,
                            false, false, true);

        for (int i = 0; i < numOutputChannels; ++i)
        {
            channels[totalNumChans] = outputChannelData[i];
            memcpy (channels[totalNumChans], inputChannelData[i], (size_t) numSamples * sizeof (float));
            ++totalNumChans;
        }

        for (int i = numOutputChannels; i < numInputChannels; ++i)
        {
            channels[totalNumChans] = tempBuffer.getWritePointer (i - numOutputChannels);
            memcpy (channels[totalNumChans], inputChannelData[i], (size_t) numSamples * sizeof (float));
            ++totalNumChans;
        }
    }
    else
    {
        for (int i = 0; i < numInputChannels; ++i)
        {
            channels[totalNumChans] = outputChannelData[i];
            memcpy (channels[totalNumChans], inputChannelData[i], (size_t) numSamples * sizeof (float));
            ++totalNumChans;
        }

        for (int i = numInputChannels; i < numOutputChannels; ++i)
        {
            channels[totalNumChans] = outputChannelData[i];
            zeromem (channels[totalNumChans], (size_t) numSamples * sizeof (float));
            ++totalNumChans;
        }
    }

    AudioBuffer<float> buffer (channels, totalNumChans, numSamples);

    {
        const ScopedLock sl (lock);

        if (processor != nullptr)
        {
            const ScopedLock sl2 (processor->getCallbackLock());

            if (! processor->isSuspended())
            {
                if (processor->isUsingDoublePrecision())
                {
                    conversionBuffer.makeCopyOf (buffer, true);
                    processor->processBlock (conversionBuffer, incomingMidi);
                    buffer.makeCopyOf (conversionBuffer, true);
                }
                else
                {
                    processor->processBlock (buffer, incomingMidi);
                }

                if (midiOutput != nullptr)
                    midiOutput->sendBlockOfMessagesNow (incomingMidi);

                return;
            }
        }
    }

    for (int i = 0; i < numOutputChannels; ++i)
        FloatVectorOperations::clear (outputChannelData[i], numSamples);
}

void AudioProcessorPlayer::audioDeviceAboutToStart (AudioIODevice* const device)
{
    auto newSampleRate = device->getCurrentSampleRate();
    auto newBlockSize  = device->getCurrentBufferSizeSamples();
    auto numChansIn    = device->getActiveInputChannels().countNumberOfSetBits();
    auto numChansOut   = device->getActiveOutputChannels().countNumberOfSetBits();

    const ScopedLock sl (lock);

    sampleRate = newSampleRate;
    blockSize  = newBlockSize;
    numInputChans  = numChansIn;
    numOutputChans = numChansOut;

    messageCollector.reset (sampleRate);
    channels.calloc (jmax (numChansIn, numChansOut) + 2);

    if (processor != nullptr)
    {
        if (isPrepared)
            processor->releaseResources();

        auto* oldProcessor = processor;
        setProcessor (nullptr);
        setProcessor (oldProcessor);
    }
}

void AudioProcessorPlayer::audioDeviceStopped()
{
    const ScopedLock sl (lock);

    if (processor != nullptr && isPrepared)
        processor->releaseResources();

    sampleRate = 0.0;
    blockSize = 0;
    isPrepared = false;
    tempBuffer.setSize (1, 1);
}

void AudioProcessorPlayer::handleIncomingMidiMessage (MidiInput*, const MidiMessage& message)
{
    messageCollector.addMessageToQueue (message);
}

} // namespace juce