JUCE/modules/juce_dsp/widgets/juce_Chorus.cpp

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

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

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

   For the technical preview this file cannot be licensed commercially.

   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>
Chorus<SampleType>::Chorus()
{
    auto oscFunction = [] (SampleType x) { return std::sin (x); };
    osc.initialise (oscFunction);

    dryWet.setMixingRule (DryWetMixingRule::linear);
}

template <typename SampleType>
void Chorus<SampleType>::setRate (SampleType newRateHz)
{
    jassert (isPositiveAndBelow (newRateHz, static_cast<SampleType> (100.0)));

    rate = newRateHz;
    update();
}

template <typename SampleType>
void Chorus<SampleType>::setDepth (SampleType newDepth)
{
    jassert (isPositiveAndNotGreaterThan (newDepth, maxDepth));

    depth = newDepth;
    update();
}

template <typename SampleType>
void Chorus<SampleType>::setCentreDelay (SampleType newDelayMs)
{
    jassert (isPositiveAndBelow (newDelayMs, maxCentreDelayMs));

    centreDelay = jlimit (static_cast<SampleType> (1.0), maxCentreDelayMs, newDelayMs);
}

template <typename SampleType>
void Chorus<SampleType>::setFeedback (SampleType newFeedback)
{
    jassert (newFeedback >= static_cast<SampleType> (-1.0) && newFeedback <= static_cast<SampleType> (1.0));

    feedback = newFeedback;
    update();
}

template <typename SampleType>
void Chorus<SampleType>::setMix (SampleType newMix)
{
    jassert (isPositiveAndNotGreaterThan (newMix, static_cast<SampleType> (1.0)));

    mix = newMix;
    update();
}

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

    sampleRate = spec.sampleRate;

    const auto maxPossibleDelay = std::ceil ((maximumDelayModulation * maxDepth * oscVolumeMultiplier + maxCentreDelayMs)
                                             * sampleRate / 1000.0);
    delay = DelayLine<SampleType, DelayLineInterpolationTypes::Linear>{ static_cast<int> (maxPossibleDelay) };
    delay.prepare (spec);

    dryWet.prepare (spec);
    feedbackVolume.resize (spec.numChannels);
    lastOutput.resize (spec.numChannels);

    osc.prepare (spec);
    bufferDelayTimes.setSize (1, (int) spec.maximumBlockSize, false, false, true);

    update();
    reset();
}

template <typename SampleType>
void Chorus<SampleType>::reset()
{
    std::fill (lastOutput.begin(), lastOutput.end(), static_cast<SampleType> (0));

    delay.reset();
    osc.reset();
    dryWet.reset();

    oscVolume.reset (sampleRate, 0.05);

    for (auto& vol : feedbackVolume)
        vol.reset (sampleRate, 0.05);
}

template <typename SampleType>
void Chorus<SampleType>::update()
{
    osc.setFrequency (rate);
    oscVolume.setTargetValue (depth * oscVolumeMultiplier);
    dryWet.setWetMixProportion (mix);

    for (auto& vol : feedbackVolume)
        vol.setTargetValue (feedback);
}

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

} // namespace dsp
} // namespace juce