JUCE/modules/juce_dsp/widgets/juce_Phaser.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>
Phaser<SampleType>::Phaser()
{
    auto oscFunction = [] (SampleType x) { return std::sin (x); };
    osc.initialise (oscFunction);

    for (auto n = 0; n < numStages; ++n)
    {
        filters.add (new FirstOrderTPTFilter<SampleType>());
        filters[n]->setType (FirstOrderTPTFilterType::allpass);
    }

    dryWet.setMixingRule (DryWetMixingRule::linear);
}

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

    rate = newRateHz;
    update();
}

template <typename SampleType>
void Phaser<SampleType>::setDepth (SampleType newDepth)
{
    jassert (isPositiveAndNotGreaterThan (newDepth, static_cast<SampleType> (1.0)));

    depth = newDepth;
    update();
}

template <typename SampleType>
void Phaser<SampleType>::setCentreFrequency (SampleType newCentreHz)
{
    jassert (isPositiveAndBelow (newCentreHz, static_cast<SampleType> (sampleRate * 0.5)));

    centreFrequency = newCentreHz;
    normCentreFrequency = mapToLog10 (centreFrequency, static_cast<SampleType> (20.0), static_cast<SampleType> (jmin (20000.0, 0.49 * sampleRate)));
}

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

    feedback = newFeedback;
    update();
}

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

    mix = newMix;
    update();
}

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

    sampleRate = spec.sampleRate;

    for (auto n = 0; n < numStages; ++n)
        filters[n]->prepare (spec);

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

    auto specDown = spec;
    specDown.sampleRate /= (double) maxUpdateCounter;
    specDown.maximumBlockSize = specDown.maximumBlockSize / (uint32) maxUpdateCounter + 1;

    osc.prepare (specDown);
    bufferFrequency.setSize (1, (int) specDown.maximumBlockSize, false, false, true);

    update();
    reset();
}

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

    for (auto n = 0; n < numStages; ++n)
        filters[n]->reset();

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

    oscVolume.reset (sampleRate / (double) maxUpdateCounter, 0.05);

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

    updateCounter = 0;
}

template <typename SampleType>
void Phaser<SampleType>::update()
{
    osc.setFrequency (rate);
    oscVolume.setTargetValue (depth * (SampleType) 0.5);
    dryWet.setWetMixProportion (mix);

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

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

} // namespace dsp
} // namespace juce