vumeter.hpp

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#pragma once
#include <dsp/common.hpp>
 
 
namespace rack {
namespace dsp {
 

struct VuMeter {
    float dBInterval = 3.0;
    float dBScaled;
    void setValue(float v) {
        dBScaled = std::log10(std::fabs(v)) * 20.0 / dBInterval;
    }

    float getBrightness(int i) {
        if (i == 0) {
            return (dBScaled >= 0.0) ? 1.0 : 0.0;
        }
        else {
            return math::clamp(dBScaled + i, 0.0, 1.0);
        }
    }
};
 
DEPRECATED typedef VuMeter VUMeter;
 

struct VuMeter2 {
    enum Mode {
        PEAK,
        RMS
    };
    Mode mode = PEAK;
    float v = 0.f;
    float lambda = 30.f;
 
    void reset() {
        v = 0.f;
    }
 
    void process(float deltaTime, float value) {
        if (mode == RMS) {
            value = std::pow(value, 2);
            v += (value - v) * lambda * deltaTime;
        }
        else {
            value = std::fabs(value);
            if (value >= v) {
                v = value;
            }
            else {
                v += (value - v) * lambda * deltaTime;
            }
        }
    }

    float getBrightness(float dbMin, float dbMax) {
        float db = amplitudeToDb((mode == RMS) ? std::sqrt(v) : v);
        if (db >= dbMax)
            return 1.f;
        else if (db <= dbMin)
            return 0.f;
        else
            return math::rescale(db, dbMin, dbMax, 0.f, 1.f);
    }
};
 
 
} // namespace dsp
} // namespace rack