terion/Source/PluginProcessor.h

#pragma once
#include <juce_audio_processors/juce_audio_processors.h>
#include <juce_dsp/juce_dsp.h>
#include <atomic>
#include <vector>

struct StereoSample
{
    float mid = 0.0f;
    float side = 0.0f;
    float age = 0.0f;
};

struct StereoMetrics
{
    float correlation = 0.0f;      // -1 to +1
    float stereoWidth = 0.0f;     // dB
    float midLevel = 0.0f;        // dB
    float sideLevel = 0.0f;       // dB
    float balance = 0.0f;         // dB (L-R)
    float phaseAngle = 0.0f;      // degrees
    float crestFactor = 0.0f;     // dB
    float peakL = 0.0f;           // dB
    float peakR = 0.0f;           // dB
    float rmsL = 0.0f;            // dB
    float rmsR = 0.0f;            // dB
};

class TerionProcessor final : public juce::AudioProcessor
{
public:
    static constexpr int kMaxPoints = 8192;

    TerionProcessor();
    ~TerionProcessor() override;

    void prepareToPlay(double sampleRate, int samplesPerBlock) override;
    void releaseResources() override;
    void processBlock(juce::AudioBuffer<float>&, juce::MidiBuffer&) override;

    juce::AudioProcessorEditor* createEditor() override;
    bool hasEditor() const override { return true; }

    const juce::String getName() const override { return "Terion"; }
    bool acceptsMidi() const override { return false; }
    bool producesMidi() const override { return false; }
    bool isMidiEffect() const override { return false; }
    double getTailLengthSeconds() const override { return 0.0; }

    int getNumPrograms() override { return 1; }
    int getCurrentProgram() override { return 0; }
    void setCurrentProgram(int) override {}
    const juce::String getProgramName(int) override { return {}; }
    void changeProgramName(int, const juce::String&) override {}

    void getStateInformation(juce::MemoryBlock& destData) override;
    void setStateInformation(const void* data, int sizeInBytes) override;

    const std::vector<StereoSample>& getPoints() const { return points; }
    const StereoMetrics& getMetrics() const { return metrics; }

    juce::AudioProcessorValueTreeState apvts;

    enum class ParameterID
    {
        fadeTime = 1,
        sensitivity = 2,
        dotSize = 3,
        smoothing = 4,
        freeze = 5,
        mono = 6
    };

private:
    std::vector<StereoSample> points;
    StereoMetrics metrics;
    int writePos = 0;
    bool filled = false;

    // Smoothing filters
    float midSmoothed = 0.0f;
    float sideSmoothed = 0.0f;

    // Metrics calculation state
    float sumMid = 0.0f;
    float sumSide = 0.0f;
    float sumMidSide = 0.0f;
    float sumMid2 = 0.0f;
    float sumSide2 = 0.0f;
    float peakMid = 0.0f;
    float peakSide = 0.0f;
    int metricsCount = 0;

    void addPoint(float mid, float side, float age);
    void updateMetrics(float mid, float side, float left, float right);

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(TerionProcessor)
};