JUCE/modules/juce_dsp/processors/juce_DryWetMixer.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
{
namespace dsp
{

//==============================================================================
template <typename SampleType>
DryWetMixer<SampleType>::DryWetMixer()
    : DryWetMixer (0)
{
}

template <typename SampleType>
DryWetMixer<SampleType>::DryWetMixer (int maximumWetLatencyInSamples)
    : dryDelayLine (maximumWetLatencyInSamples)
{
    dryDelayLine.setDelay (0);

    update();
    reset();
}

//==============================================================================
template <typename SampleType>
void DryWetMixer<SampleType>::setMixingRule (MixingRule newRule)
{
    currentMixingRule = newRule;
    update();
}

template <typename SampleType>
void DryWetMixer<SampleType>::setWetMixProportion (SampleType newWetMixProportion)
{
    jassert (isPositiveAndNotGreaterThan (newWetMixProportion, 1.0));

    mix = jlimit (static_cast<SampleType> (0.0), static_cast<SampleType> (1.0), newWetMixProportion);
    update();
}

template <typename SampleType>
void DryWetMixer<SampleType>::setWetLatency (SampleType wetLatencySamples)
{
    dryDelayLine.setDelay (wetLatencySamples);
}

//==============================================================================
template <typename SampleType>
void DryWetMixer<SampleType>::prepare (const ProcessSpec& spec)
{
    jassert (spec.sampleRate > 0);
    jassert (spec.numChannels > 0);

    sampleRate = spec.sampleRate;

    dryDelayLine.prepare (spec);
    bufferDry.setSize ((int) spec.numChannels, (int) spec.maximumBlockSize, false, false, true);

    update();
    reset();
}

template <typename SampleType>
void DryWetMixer<SampleType>::reset()
{
    dryVolume.reset (sampleRate, 0.05);
    wetVolume.reset (sampleRate, 0.05);

    dryDelayLine.reset();
}

//==============================================================================
template <typename SampleType>
void DryWetMixer<SampleType>::pushDrySamples (const AudioBlock<const SampleType> drySamples)
{
    jassert (drySamples.getNumChannels() <= (size_t) bufferDry.getNumChannels());

    auto dryBlock = AudioBlock<SampleType> (bufferDry);
    dryBlock = dryBlock.getSubsetChannelBlock (0, drySamples.getNumChannels()).getSubBlock (0, drySamples.getNumSamples());

    auto context = ProcessContextNonReplacing<SampleType>(drySamples, dryBlock);
    dryDelayLine.process (context);
}

template <typename SampleType>
void DryWetMixer<SampleType>::mixWetSamples (AudioBlock<SampleType> inOutBlock)
{
    auto dryBlock = AudioBlock<SampleType> (bufferDry);
    dryBlock = dryBlock.getSubsetChannelBlock (0, inOutBlock.getNumChannels()).getSubBlock (0, inOutBlock.getNumSamples());

    dryBlock.multiplyBy (dryVolume);
    inOutBlock.multiplyBy (wetVolume);

    inOutBlock.add (dryBlock);
}

//==============================================================================
template <typename SampleType>
void DryWetMixer<SampleType>::update()
{
    SampleType dryValue, wetValue;

    switch (currentMixingRule)
    {
        case MixingRule::balanced:
            dryValue = static_cast<SampleType> (2.0) * jmin (static_cast<SampleType> (0.5), static_cast<SampleType> (1.0) - mix);
            wetValue = static_cast<SampleType> (2.0) * jmin (static_cast<SampleType> (0.5), mix);
            break;

        case MixingRule::linear:
            dryValue  = static_cast<SampleType> (1.0) - mix;
            wetValue = mix;
            break;

        case MixingRule::sin3dB:
            dryValue = static_cast<SampleType> (std::sin (0.5 * MathConstants<double>::pi * (1.0 - mix)));
            wetValue = static_cast<SampleType> (std::sin (0.5 * MathConstants<double>::pi * mix));
            break;

        case MixingRule::sin4p5dB:
            dryValue = static_cast<SampleType> (std::pow (std::sin (0.5 * MathConstants<double>::pi * (1.0 - mix)), 1.5));
            wetValue = static_cast<SampleType> (std::pow (std::sin (0.5 * MathConstants<double>::pi * mix), 1.5));
            break;

        case MixingRule::sin6dB:
            dryValue = static_cast<SampleType> (std::pow (std::sin (0.5 * MathConstants<double>::pi * (1.0 - mix)), 2.0));
            wetValue = static_cast<SampleType> (std::pow (std::sin (0.5 * MathConstants<double>::pi * mix), 2.0));
            break;

        case MixingRule::squareRoot3dB:
            dryValue = std::sqrt (static_cast<SampleType> (1.0) - mix);
            wetValue = std::sqrt (mix);
            break;

        case MixingRule::squareRoot4p5dB:
            dryValue = static_cast<SampleType> (std::pow (std::sqrt (1.0 - mix), 1.5));
            wetValue = static_cast<SampleType> (std::pow (std::sqrt (mix), 1.5));
            break;

        default:
            dryValue = jmin (static_cast<SampleType> (0.5), static_cast<SampleType> (1.0) - mix);
            wetValue = jmin (static_cast<SampleType> (0.5), mix);
            break;
    }

    dryVolume.setTargetValue (dryValue);
    wetVolume.setTargetValue (wetValue);
}

//==============================================================================
template class DryWetMixer<float>;
template class DryWetMixer<double>;

} // namespace dsp
} // namespace juce