add parameter store

CMakeLists.txt

@@ -44,6 +44,7 @@ qt_add_executable(metabolus
     src/MainWindow.cpp
     src/MainWindow.h
     src/MainWindow.ui
+    src/ParameterStore.h
     src/synth/AudioEngine.cpp
     src/synth/AudioEngine.h
     src/synth/Synth.cpp

src/MainWindow.cpp

@@ -1,6 +1,8 @@
 
 #include "MainWindow.h"
+
 #include "ui_MainWindow.h"
+#include "ParameterStore.h"
 
 MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) {
 
@@ -14,6 +16,7 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWi
     connect(ui->buttonReset, &QPushButton::clicked, this, &MainWindow::onResetClicked);
 
     // slider business
+    // TODO: smart slider widget
     connect(ui->slider,     &QSlider::valueChanged,      this, &MainWindow::onSliderValueChanged);
     connect(ui->inputMin,   &QLineEdit::editingFinished, this, &MainWindow::onMinChanged);
     connect(ui->inputMax,   &QLineEdit::editingFinished, this, &MainWindow::onMaxChanged);
@@ -24,6 +27,14 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWi
     audio_ = new AudioEngine();
     audio_->start();
 
+    // init defaults
+    // TODO:: there's gotta be a better way
+    ui->slider->setValue(PARAM_DEFS[static_cast<size_t>(ParamId::Osc1Frequency)].def);
+    ui->slider->setMinimum(PARAM_DEFS[static_cast<size_t>(ParamId::Osc1Frequency)].min);
+    ui->slider->setMaximum(PARAM_DEFS[static_cast<size_t>(ParamId::Osc1Frequency)].max);
+    ui->inputValue->setText(QString::number(PARAM_DEFS[static_cast<size_t>(ParamId::Osc1Frequency)].def));
+    ui->inputMin->setText(QString::number(PARAM_DEFS[static_cast<size_t>(ParamId::Osc1Frequency)].min));
+    ui->inputMax->setText(QString::number(PARAM_DEFS[static_cast<size_t>(ParamId::Osc1Frequency)].max));
 }
 
 MainWindow::~MainWindow() {
@@ -49,7 +60,8 @@ void MainWindow::onSliderValueChanged(int value) {
     QSignalBlocker blocker(ui->inputValue);
     ui->inputValue->setText(QString::number(value));
 
-    audio_->setFrequency(static_cast<float>(value));
+    // forward value so synthesizer can read
+    audio_->parameters()->set(ParamId::Osc1Frequency, static_cast<float>(value));
 }
 
 // allows only values within the min, max to be set by the text field

src/MainWindow.h

@@ -42,5 +42,4 @@ private:
     void syncValueToUi(int value);
 
     AudioEngine* audio_ = nullptr;
-
 };

src/ParameterStore.h

@@ -0,0 +1,80 @@
+
+#pragma once
+
+#include <cstdint>
+#include <array>
+#include <atomic>
+
+enum class ParamId : uint16_t {
+    Osc1Frequency,
+    Osc1Gain,
+    Osc1VolumeEnvA,
+    Osc1VolumeEnvD,
+    Osc1VolumeEnvS,
+    Osc1VolumeEnvR,
+    FilterCutoffEnvA,
+    FilterCutoffEnvD,
+    FilterCutoffEnvS,
+    FilterCutoffEnvR,
+    FilterResonanceEnvA,
+    FilterResonanceEnvD,
+    FilterResonanceEnvS,
+    FilterResonanceEnvR,
+    // ... and so on
+    // this list could be like 200 long if I really wanted to
+    Count // for sizing
+};
+
+struct ParamDef {
+    float def;
+    float min;
+    float max;
+};
+
+// TODO: make these configurable via yml file too
+// TODO: and then when I have full on profile saving there will be a default profile to load from
+constexpr std::array<ParamDef, static_cast<size_t>(ParamId::Count)> PARAM_DEFS {{
+    { 100.0f, 20.0f, 600.0f},   // Osc1Freq
+    { 0.8f, 0.0f, 1.0f},        // Osc1Gain
+    { 10.0f, 0.0f, 1000.0f},    // Osc1VolumeEnvA,
+    { 10.0f, 0.0f, 1000.0f},    // Osc1VolumeEnvD,
+    { 10.0f, 0.0f, 1000.0f},    // Osc1VolumeEnvS,
+    { 10.0f, 0.0f, 1000.0f},    // Osc1VolumeEnvR,
+    { 10.0f, 0.0f, 1000.0f},    // FilterCutoffEnvA,
+    { 10.0f, 0.0f, 1000.0f},    // FilterCutoffEnvD,
+    { 10.0f, 0.0f, 1000.0f},    // FilterCutoffEnvS,
+    { 10.0f, 0.0f, 1000.0f},    // FilterCutoffEnvR,
+    { 10.0f, 0.0f, 1000.0f},    // FilterResonanceEnvA,
+    { 10.0f, 0.0f, 1000.0f},    // FilterResonanceEnvD,
+    { 10.0f, 0.0f, 1000.0f},    // FilterResonanceEnvS,
+    { 10.0f, 0.0f, 1000.0f},    // FilterResonanceEnvR,
+}};
+
+constexpr size_t PARAM_COUNT = static_cast<size_t>(ParamId::Count);
+
+class ParameterStore {
+
+public:
+
+    ParameterStore() { resetToDefaults(); }
+    ~ParameterStore() = default;
+
+    // TODO: move into implementation file ? idk
+    void set(ParamId id, float value) {
+        values_[static_cast<size_t>(id)].store(value, std::memory_order_relaxed);
+    }
+    float get(ParamId id) const {
+        return values_[static_cast<size_t>(id)].load(std::memory_order_relaxed);
+    }
+
+    void resetToDefaults() {
+        for(size_t i = 0; i < PARAM_COUNT; i++) {
+            values_[i].store(PARAM_DEFS[i].def, std::memory_order_relaxed);
+        }
+    }
+
+private:
+
+    std::array<std::atomic<float>, PARAM_COUNT> values_;
+
+};

src/synth/AudioEngine.cpp

@@ -1,18 +1,17 @@
 
 #include "AudioEngine.h"
 
-#define _USE_MATH_DEFINES
-#include <cmath>
 #include <iostream>
 
-#ifndef M_PI // I hate my stupid chungus life
+AudioEngine::AudioEngine() : synth_(params_) {
-    #define M_PI 3.14159265358979323846
-#endif
-
-AudioEngine::AudioEngine() {
     if(audio_.getDeviceCount() < 1) {
         throw std::runtime_error("No audio devices found");
     }
+
+    // TODO: get audio configurations
+
+    synth_.setSampleRate(sampleRate_);
+
 }
 
 AudioEngine::~AudioEngine() {
@@ -23,24 +22,17 @@ bool AudioEngine::start() {
 
     RtAudio::StreamParameters params;
     params.deviceId = audio_.getDefaultOutputDevice();
-    params.nChannels = 2;
+    params.nChannels = channels_;
     params.firstChannel = 0;
 
     RtAudio::StreamOptions options;
     options.flags = RTAUDIO_MINIMIZE_LATENCY;
 
-    /*
+    // TODO: error check this please
-    try {
-        audio_.openStream(&params, nullptr, RTAUDIO_FLOAT32, sampleRate_, &bufferFrames_, &AudioEngine::audioCallback, this, &options);
-        audio_.startStream();
-    } catch(RtAudioError& e) {
-        std::cerr << e.getMessage() << std::endl;
-        return false;
-    }
-    */
     audio_.openStream(&params, nullptr, RTAUDIO_FLOAT32, sampleRate_, &bufferFrames_, &AudioEngine::audioCallback, this, &options);
     audio_.startStream();
 
+    // sanity check
     std::cout << "sample rate: " << sampleRate_ << "  buffer frames: " << bufferFrames_ << std::endl;
     return true;
 
@@ -52,10 +44,6 @@ void AudioEngine::stop() {
     if(audio_.isStreamOpen()) audio_.closeStream();
 }
 
-void AudioEngine::setFrequency(float freq) {
-    targetFreq_.store(freq, std::memory_order_relaxed);
-}
-
 int32_t AudioEngine::audioCallback( void* outputBuffer, void*, uint32_t nFrames, double, RtAudioStreamStatus status, void* userData) {
     
     if (status) std::cerr << "Stream underflow!" << std::endl;
@@ -64,21 +52,9 @@ int32_t AudioEngine::audioCallback( void* outputBuffer, void*, uint32_t nFrames,
 }
 
 int32_t AudioEngine::process(float* out, uint32_t nFrames) {
-    const float sr = static_cast<float>(sampleRate_);
-    float target = targetFreq_.load(std::memory_order_relaxed);
-    float freqStep = (target - currentFreq_) / nFrames;
 
-    for (uint32_t i = 0; i < nFrames; ++i) {
+    // pass to synth
-        currentFreq_ += freqStep;
+    synth_.process(out, nFrames, sampleRate_);
-
-        float phaseInc = 2.0f * M_PI * currentFreq_ / sr;
-
-        out[2*i] = std::sin(phase_); // left
-        out[2*i+1] = std::sin(phase_); // right
-
-        phase_ += phaseInc;
-        if (phase_ > 2.0f * M_PI) phase_ -= 2.0f * M_PI;
-    }
 
     return 0;
 }

src/synth/AudioEngine.h

@@ -5,6 +5,8 @@
 #include <stdint.h>
 #include <atomic>
 
+#include "Synth.h"
+
 class AudioEngine {
 
 public:
@@ -13,19 +15,19 @@ public:
 
     bool start();
     void stop();
-
+    ParameterStore* parameters() { return &params_; }
-    void setFrequency(float freq);
 
 private: 
     static int32_t audioCallback(void* outputBuffer, void* inputBuffer, uint32_t nFrames, double streamTime, RtAudioStreamStatus status, void* userData);
     int32_t process(float* out, uint32_t nFrames);
 
+    ParameterStore params_;
+    Synth synth_;
+
+    // TODO: id like a yml config file or something for these
     RtAudio audio_;
     uint32_t sampleRate_ = 44100;
-    uint32_t bufferFrames_ = 256;
+    uint32_t bufferFrames_ = 256; // time per buffer = BF/SR (256/44100 = 5.8ms)
-
+    uint32_t channels_ = 2; // stereo
-    std::atomic<float> targetFreq_{ 400.0f };
-    float currentFreq_ = 440.0f;
-    float phase_ = 0.0f;
 
 };

src/synth/Synth.cpp

@@ -1,115 +1,51 @@
 
-/*
-
 #include "Synth.h"
 
-#include <QMediaDevices>
-#include <QtMath>
 #include <iostream>
+#include <cmath>
 
-Synth::Synth(QObject *parent) : QObject(parent) {
+#ifndef M_PI // I hate my stupid chungus life
+    #define M_PI 3.14159265358979323846
+#endif
 
-    format_.setSampleRate(44100);
+Synth::Synth(const ParameterStore& params) : paramStore_(params) {
-    format_.setChannelCount(1);
-    format_.setSampleFormat(QAudioFormat::Int16);
 
-    QAudioDevice device = QMediaDevices::defaultAudioOutput();
+}
 
-    if (!device.isFormatSupported(format_)) {
+void Synth::updateParams() {
-        format_ = device.preferredFormat();
+    for(size_t i = 0; i < PARAM_COUNT; i++) {
+        params_[i].target = paramStore_.get(static_cast<ParamId>(i));
     }
-
-    audioSink_ = new QAudioSink(device, format_, this);
-    audioSink_->setBufferSize(4096);
 }
 
-Synth::~Synth() {
+inline float Synth::getParam(ParamId id) {
-
+    return params_[static_cast<size_t>(id)].current;
-    stop();
 }
 
-void Synth::start() {
+void Synth::process(float* out, uint32_t nFrames, uint32_t sampleRate) {
-
-    // std::cout << "Synth::start()" << std::endl;
-    // if (audioSink_->state() == QAudio::ActiveState)
-    //     return;
-
-    // audioDevice_ = audioSink_->start();
     
-}
+    // yeah really only need to update this once per buffer if its ~6ms latency
+    updateParams();
 
-void Synth::stop() {
+    for (uint32_t i = 0; i < nFrames; i++) {
 
-    if (audioSink_) {
+        for(auto& p : params_) p.update(); // TODO: profile this
-        audioSink_->stop();
-        audioDevice_ = nullptr;
-    }
-}
 
-void Synth::setFrequency(float frequency) {
+        // based on oscillator frequency
+        float frequency = getParam(ParamId::Osc1Frequency); // this will come from a midi controller
+        float phaseInc = 2.0f * M_PI * frequency / static_cast<float>(sampleRate);
 
-    frequency_ = qMax(1.0f, frequency);
+        // sample generation
-}
+        float gain = getParam(ParamId::Osc1Gain);
+        float sample = std::sin(phase_) * gain;
 
-QByteArray Synth::generateSamples(qint64 bytes) {
+        // write to buffer
+        out[2*i] = sample; // left
+        out[2*i+1] = sample; // right
 
-    QByteArray buffer(bytes, Qt::Uninitialized);
+        // sampling business
-
+        phase_ += phaseInc;
-    const int channels = format_.channelCount();
+        if (phase_ > 2.0f * M_PI) phase_ -= 2.0f * M_PI;
-    const int sampleRate = format_.sampleRate();
-    //const float phaseInc = 2.0f * M_PI * frequency_ / sampleRate;
-    freq += 1.0f;
-    const float phaseInc = 2.0f * M_PI * freq / sampleRate;
-
-    if (format_.sampleFormat() == QAudioFormat::Int16) {
-        int16_t* out = reinterpret_cast<int16_t*>(buffer.data());
-        int frames = bytes / (sizeof(int16_t) * channels);
-
-        for (int i = 0; i < frames; ++i) {
-            int16_t s = static_cast<int16_t>(32767 * std::sin(phase_));
-            for (int c = 0; c < channels; ++c)
-                *out++ = s;
-            phase_ += phaseInc;
-        }
-    }
-    else if (format_.sampleFormat() == QAudioFormat::Float) {
-        float* out = reinterpret_cast<float*>(buffer.data());
-        int frames = bytes / (sizeof(float) * channels);
-
-        for (int i = 0; i < frames; ++i) {
-            float s = std::sin(phase_);
-            for (int c = 0; c < channels; ++c)
-                *out++ = s;
-            phase_ += phaseInc;
-        }
     }
 
-    return buffer;
+}
-}
-
-void Synth::applyConfig(const AudioConfig& config) {
-
-    // map struct values to the QAudioFormat
-    QAudioFormat format;
-    format.setSampleRate(config.sampleRate);
-    format.setChannelCount(config.channelCount);
-    format.setSampleFormat(config.sampleFormat);
-
-    // must create a new device
-    QAudioDevice device = QMediaDevices::defaultAudioOutput();
-
-    if (!device.isFormatSupported(format)) {
-        std::cout << "Requested format not supported, using preferred format" << std::endl;
-        format = device.preferredFormat();
-    }
-
-    format_ = format;
-
-    // and must create a new audioSink
-    delete audioSink_;
-    audioSink_ = new QAudioSink(device, format_, this);
-
-    audioSink_->setBufferSize(config.bufferSize);
-}
-
-*/

src/synth/Synth.h

@@ -1,52 +1,38 @@
 
 #pragma once
 
-/*
+#include "../ParameterStore.h"
-
-#include <QObject>
-#include <QAudioFormat>
-#include <QAudioSink>
-#include <QIODevice>
 
 #include <atomic>
 
-struct AudioConfig {
+struct SmoothedParam {
-    int sampleRate = 44100;
+    float current = 0.0f;
-    int channelCount = 1;
+    float target = 0.0f;
-    QAudioFormat::SampleFormat sampleFormat = QAudioFormat::Int16;
+    float gain = 0.001f;
-    int bufferSize = 4096; // bytes
+
+    inline void update() {
+        current += gain * (target - current);
+    }
 };
 
-class Synth : public QObject {
+class Synth {
-    Q_OBJECT
 
 public:
-    explicit Synth(QObject *parent = nullptr);
+    Synth(const ParameterStore& params);
-    ~Synth();
+    ~Synth() = default;
 
-    // audioSink is the media consumer for the audio data
+    void process(float* out, uint32_t nFrames, uint32_t sampleRate);
-    QAudioSink* audioSink() { return audioSink_; }
+    void setSampleRate(uint32_t sampleRate) { sampleRate_ = sampleRate; }
-
-    // audio config setter/getter 
-    void applyConfig(const AudioConfig& config);
-    const QAudioFormat& format() const { return format_; }
-
-    // synth commands
-    void start();
-    void stop();
-    void setFrequency(float frequency);
-    // bread and butter right here
-    QByteArray generateSamples(qint64 bytes);
 
 private:
-    QAudioFormat format_;
-    QAudioSink *audioSink_ = nullptr;
-    QIODevice *audioDevice_ = nullptr;
 
-    std::atomic<float> frequency_{440.0f};
+    void updateParams();
+    inline float getParam(ParamId);
+
+    const ParameterStore& paramStore_;
+    // smoothed params creates a buffer in case the thread controlling paramStore gets blocked
+    std::array<SmoothedParam, PARAM_COUNT> params_;
+    uint32_t sampleRate_;
+
     float phase_ = 0.0f;
-
-    float freq = 400.0f;
 };
-
-*/