simpledelay2.h

class SimpleDelay2
{
public:
    SimpleDelay2() {}
    void prepare(float samplerate, int numchans, float delaytime_ramp_dur_seconds, float maxdelaytime_seconds)
    {
        mDelayTime.reset(samplerate, delaytime_ramp_dur_seconds); 
        mWetDryMix.reset(samplerate, 0.05f); // 50 millisecond ramps for the wet dry
        mFeedBackAmount.reset(samplerate, 0.05f); // likewise for feedback gain
        mDelayLine.setMaximumDelayInSamples(maxdelaytime_seconds*samplerate);
        juce::dsp::ProcessSpec spec;
        spec.maximumBlockSize = 0; // we only use the sample by sample processing of the delay line, so this can be zero
        spec.numChannels = numchans;
        spec.sampleRate = samplerate;
        mDelayLine.prepare(spec);
    }
    void processBlock(juce::AudioBuffer<float>& buffer)
    {
        auto ptrs = buffer.getArrayOfWritePointers();
        // Might be a tiny bit more efficient to have the loops running the other way around (channels first, then samples)
        // but then we'd have to add more complicated code to get the smoothed delay time, feedback gain and wetdry values
        for (int i = 0; i < buffer.getNumSamples(); ++i)
        {
            float smootheddelaytime = mDelayTime.getNextValue();
            float smoothedmix = mWetDryMix.getNextValue();
            float smoothedfeedbackgain = mFeedBackAmount.getNextValue();
            for (int j = 0; j < buffer.getNumChannels(); ++j)
            {
                float input = ptrs[j][i];
                mDelayLine.pushSample(j, input + mFeedBackSignals[j] * smoothedfeedbackgain);
                float output = mDelayLine.popSample(j, smootheddelaytime);
                mFeedBackSignals[j] = output;
                output = output * smoothedmix + input * (1.0f - smoothedmix);
                ptrs[j][i] = output;
            }
        }
    }
    void setFeedbackGain(float g)
    {
        mFeedBackAmount.setTargetValue(g);
    }
    void setWetDryMix(float m)
    {
        mWetDryMix.setTargetValue(m);
    }
    void setDelayTimeSamples(float dtime)
    {
        mDelayTime.setTargetValue(dtime);
    }
    void setDelayTimeSeconds(float seconds, float samplerate)
    {
        mDelayTime.setTargetValue(seconds*samplerate);
    }
private:
    juce::dsp::DelayLine<float> mDelayLine;
    float mFeedBackSignals[2] = { 0.0f,0.0f };
    juce::SmoothedValue<float> mFeedBackAmount;
    juce::SmoothedValue<float> mWetDryMix;
    juce::SmoothedValue<float> mDelayTime;
};