scope checkpoint

CMakeLists.txt

@@ -27,6 +27,11 @@ FetchContent_Declare(
     GIT_REPOSITORY  https://github.com/hyperrealm/libconfig.git
     GIT_TAG         v1.8.2
 )
+FetchContent_Declare(
+    eigen
+    GIT_REPOSITORY  git@gitlab.com:libeigen/eigen.git
+    GIT_TAG         5.0
+)
 FetchContent_MakeAvailable(rtaudio)
 FetchContent_MakeAvailable(rtmidi)
 FetchContent_MakeAvailable(libconfig)

README.md

@@ -29,7 +29,7 @@ to produce somewhat well-sounding instruments and music performance.
       to external midi controllers/apps (like musescore)
 - [ ] Create a UI scope to visualize the synthesized composite waveform
 - [ ] Check cross-platform combatibility for Windows & Linux, especially MIDI interfacing
-- [ ] Checkpoint at a rudimentary keyboard instrument producing a basic sine output
+- [x] Checkpoint at a rudimentary keyboard instrument producing a basic sine output
 - [ ] Will flesh out future goals when I do the math on how complicated implementing
       state-space modelling in c++ is
 

src/main.cpp

@@ -10,7 +10,7 @@
 #include "ConfigService.hpp"
 #include "synth/AudioEngine.hpp"
 #include "synth/KeyboardController.hpp"
-//#include "synth/ScopeBuffer.hpp"
+#include "synth/Scope.hpp"
 
 int main(int argc, char* argv[]) {
 
@@ -22,7 +22,7 @@ int main(int argc, char* argv[]) {
     ConfigService config = ConfigService("config/sonobulus.cfg");
     LoggerService logger = LoggerService(&config, "Engine");
     NoteQueue queue = NoteQueue();
-    //ScopeBuffer scope = ScopeBuffer();
+    ScopeBuffer scopeBuffer = ScopeBuffer(512);
     KeyboardController keyboard(&config, &logger, &queue);
     Synth synth(&config, &logger, nullptr, &queue);
 
@@ -31,9 +31,11 @@ int main(int argc, char* argv[]) {
     audioEngine.start();
 
     // attach backend gui components
+    //Scope scope; //scope.setBuffer(&scopeBuffer);
     qmlRegisterType<TimerComponent>("AppDemo", 1, 0, "TimerComponent");
+    //qmlRegisterSingletonInstance("AppDemo", 1, 0, "Scope", &scope);
+    qmlRegisterType<Scope>("AppDemo", 1, 0, "Scope");
     engine.rootContext()->setContextProperty("keyboardController", &keyboard);
-    // adds the TimerComponent type (exposed in qml as "TimerComponent") to the module named"AppDemo" (numbers mean version 1.0)
 
     // load qml
     //engine.loadFromModule("sonobulus", "Main");

src/synth/Instrument.cpp

@@ -10,11 +10,10 @@ Instrument::Instrument(ConfigService* config, LoggerService* logger) :
 
 void Instrument::noteOn(float frequency, float velocity) {
 
-    // std::string msg = "NoteOn Frequency = " + std::to_string(frequency);
-    // if(logger_ != nullptr) logger_->log("Instrument", LogFlag::Debug, msg);
-
     phaseIncrement_ = 2.0f * pi * frequency / sampleRate_;
 
+    envelope_ += 0.01f; // so it triggers as active
+
     active_ = true;
 }
 
@@ -23,14 +22,18 @@ void Instrument::noteOff() {
 }
 
 bool Instrument::isActive() {
-    return active_;
+    return (envelope_ > 0.0f);
 }
 
 float Instrument::process(bool& scopeTrigger) {
 
+    if(active_ && envelope_ < 1.0f) envelope_ += 0.01f;
+    if(!active_ && envelope_ > 0.0f) envelope_ -= 0.01f;
+
     phase_ += phaseIncrement_;
     if(phase_ > 2.0f * pi) phase_ -= 2.0f * pi;
 
-    return sin(phase_);
+    if(!isActive()) return 0.0f;
+    return sin(phase_) * envelope_;
 
 }

src/synth/Instrument.hpp

@@ -32,5 +32,6 @@ private:
     static constexpr float pi = 3.14159265358979323846f;
     float phase_ = 0.0f;
     float phaseIncrement_ = 0.0f;
+    float envelope_ = 0.0f;
 
 };

src/synth/Scope.cpp

@@ -0,0 +1,47 @@
+
+#include "Scope.hpp"
+
+#include <iostream>
+
+ScopeBuffer::ScopeBuffer(size_t size) : buffer_(size) {
+
+}
+
+void ScopeBuffer::push(float sample) {
+
+    size_t w = writeIndex_.fetch_add(1, std::memory_order_relaxed);
+    buffer_[w % buffer_.size()] = sample;
+}
+
+void ScopeBuffer::read(std::vector<float>& out) {
+
+    size_t w = writeIndex_.load(std::memory_order_relaxed);
+    for(size_t i = 0; i < buffer_.size(); i++) {
+        size_t idx = (w + trigger_ + i * wavelength_ / out.size()) % buffer_.size();
+        out[i] = buffer_[idx];
+    }
+
+}
+
+Scope::Scope(QQuickItem *parent) : QQuickPaintedItem(parent) {
+    setAntialiasing(true); 
+}
+
+void Scope::paint(QPainter *painter) {
+
+    //std::cout << "onPaint" << std::endl;
+
+    static float phase = 0.0f;
+    phase += 0.1f;
+    float sample = sin(phase);
+
+    QPen pen(Qt::blue, 4);
+    painter->setPen(pen);
+    painter->setRenderHint(QPainter::Antialiasing);
+
+    painter->drawRect(10, 10, width() - 20*sample, height() - 20*sample);
+    
+    painter->setPen(QPen(Qt::red, 2));
+    painter->drawLine(0, 0, width(), height());
+
+}

src/synth/Scope.hpp

@@ -1,6 +1,10 @@
 
 #pragma once
 
+#include <QObject>
+#include <QtQuick/QQuickPaintedItem>
+#include <QtGui/QPainter>
+
 #include <vector>
 #include <atomic>
 
@@ -14,14 +18,37 @@ public:
     void push(float sample);
     void read(std::vector<float>& out);
 
+    void setTrigger(size_t trigger) { trigger_ = trigger; }
+    void setWavelength(size_t wavelength) { wavelength_ = wavelength; } 
+    size_t trigger() { return trigger_; }
+    size_t wavelength() { return wavelength_; }
+    void spinlock(bool lock) { spinlock_ = lock; }
+    size_t size() { return buffer_.size(); }
+
 private:
 
     std::vector<float> buffer_;
     std::atomic<size_t> writeIndex_{0};
 
     size_t trigger_ = 0;
-    uint32_t wavelgnth = 400;
+    size_t wavelength_ = 400;
 
-    bool spinLock_ = false;
+    bool spinlock_ = false;
+
+};
+
+class Scope : public QQuickPaintedItem {
+
+    Q_OBJECT
+    QML_ELEMENT
+
+public:
+    explicit Scope(QQuickItem* parent = nullptr);
+
+    void paint(QPainter* painter) override;
+    void setBuffer(ScopeBuffer* scopeBuffer) { scopeBuffer_ = scopeBuffer; }
+
+    std::vector<float> buffer_;
+    ScopeBuffer* scopeBuffer_;
 
 };

src/synth/Synth.cpp

@@ -45,7 +45,7 @@ void Synth::process(float* out, size_t nFrames) {
         float mix = 0.0f;
         for(size_t j = 0; j < voices_.size(); j++) {
             bool temp = false;
-            if(!voices_[j].isActive()) continue;
+            //if(!voices_[j].isActive()) continue;
             mix += voices_[j].process(temp);
             // if(j == lowestVoice) triggered = temp;
         }

ui/Main.qml

@@ -6,8 +6,8 @@ import AppDemo
 
 ApplicationWindow {
     visible: true
-    width: 600
+    width: 1200
-    height: 400
+    height: 800
     title: "sonobulus"
 
     TimerComponent {
@@ -49,4 +49,20 @@ ApplicationWindow {
         }
     }
 
+    Scope {
+        id: scope
+
+        width: 600
+        height: 300
+
+        // this timer triggers a constant update on the scope's canvas, calls its draw() each time
+        Timer {
+            id: updateTimer
+            interval: 16 // ~60 fps
+            running: true
+            repeat: true
+            onTriggered: scope.update()
+        }
+    }
+
 }