Saturation.cpp

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namespace krotos
{
    Saturation::Saturation()
    {
        for (int i = 0; i < NUM_CHANNELS_MAX; i++)
        {
            m_lowCutFilters.add(std::make_unique<juce::IIRFilter>());
            m_highCutFilters.add(std::make_unique<juce::IIRFilter>());
        }
    }
 
    Saturation::~Saturation() {}
 
    void Saturation::prepareToPlay(double sampleRate, int blockSize)
    {
        m_sampleRate = sampleRate;
 
        for (int i = 0; i < NUM_CHANNELS_MAX; i++)
        {
            m_lowCutFilters[i]->setCoefficients(IIRCoefficients::makeHighPass(m_sampleRate, 20.0f));
            m_highCutFilters[i]->setCoefficients(IIRCoefficients::makeLowPass(m_sampleRate, 20000.0f));
        }
 
        dsp::ProcessSpec spec;
        spec.sampleRate = sampleRate;
        spec.maximumBlockSize = static_cast<unsigned int>(blockSize);
        spec.numChannels = static_cast<unsigned int>(NUM_CHANNELS_MAX);
        m_waveshaper.prepare(spec);
    }
 
    float Saturation::processSample(float sample, int channel)
    {
        float dry = sample;
 
        sample = m_waveshaper.processSample(sample * m_inputGain);
        sample = m_lowCutFilters[channel]->processSingleSampleRaw(sample);
        sample = m_highCutFilters[channel]->processSingleSampleRaw(sample);
        sample = std::sqrt(m_mix) * sample + std::sqrt(1.0f - m_mix) * dry;
 
        return sample * m_outputGain;
    }
 
    template <typename T> int Saturation::sign(T val) { return (T(0) < val) - (val < T(0)); }
 
    void Saturation::setInputGainDb(float gainInDb) { m_inputGain = std::pow(10.0f, gainInDb / 20.0f); }
 
    void Saturation::setOutputGainDb(float gainInDb) { m_outputGain = std::pow(10.0f, gainInDb / 20.0f); }
 
    void Saturation::setFunctionType(FunctionType function) { m_waveshaper.functionToUse = functions.at(function); }
 
    void Saturation::setLowCutFrequency(float newCutoffFrequency)
    {
        auto coeff = IIRCoefficients::makeHighPass(m_sampleRate, newCutoffFrequency);
 
        for (int i = 0; i < NUM_CHANNELS_MAX; i++)
            m_lowCutFilters[i]->setCoefficients(coeff);
    }
 
    void Saturation::setHighCutFrequency(float newCutoffFrequency)
    {
        auto coeff = IIRCoefficients::makeLowPass(m_sampleRate, newCutoffFrequency);
 
        for (int i = 0; i < NUM_CHANNELS_MAX; i++)
            m_highCutFilters[i]->setCoefficients(coeff);
    }
 
    void Saturation::setMix(float mix) { m_mix = mix; }
} // namespace krotos