allow audio engine to react to keyboard inputs

src/ConfigService.hpp

@@ -75,7 +75,8 @@ struct KeymapConfig {
                 if(item.getType() == libconfig::Setting::TypeString) note = std::string(item.c_str());
 
                 int8_t noteId = static_cast<int>(notesGroup[note]) % INT8_MAX;
-                int32_t keyId = static_cast<int>(keysGroup[key]) % INT8_MAX;
+                int32_t keyId = static_cast<int>(keysGroup[key]) % INT32_MAX;
+
                 keymap.emplace(keyId, noteId);
             }
 

src/main.cpp

@@ -17,8 +17,20 @@ int main(int argc, char* argv[]) {
     QGuiApplication app(argc, argv);
     QQmlApplicationEngine engine;
 
+    
+    // create app objects
+    ConfigService config = ConfigService("config/sonobulus.cfg");
+    LoggerService logger = LoggerService(&config, "Engine");
+    NoteQueue queue = NoteQueue();
+    KeyboardController keyboard(&config, &logger, &queue);
+
+    // audio synthesizer doohickey
+    AudioEngine audioEngine = AudioEngine(&config, &logger, &queue);
+    audioEngine.start();
+
     // attach backend gui components
     qmlRegisterType<TimerComponent>("AppDemo", 1, 0, "TimerComponent");
+    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
@@ -31,16 +43,6 @@ int main(int argc, char* argv[]) {
         return -1;
     }
 
-    // create app objects
-    ConfigService config = ConfigService("config/sonobulus.cfg");
-    LoggerService logger = LoggerService(&config, "Engine");
-    NoteQueue queue = NoteQueue();
-    KeyboardController keyboard = KeyboardController(&config, &logger, &queue);
-
-    // audio synthesizer doohickey
-    AudioEngine audioEngine = AudioEngine(&logger);
-    audioEngine.start();
-
     // execute app
     return app.exec();
 }

src/synth/AudioEngine.cpp

@@ -4,8 +4,9 @@
 #include <iostream>
 #include <cmath>
 #include <numbers>
+#include <string>
 
-AudioEngine::AudioEngine(LoggerService* logger) : logger_(logger) {
+AudioEngine::AudioEngine(ConfigService* config, LoggerService* logger, NoteQueue* noteQueue) : config_(config), logger_(logger), noteQueue_(noteQueue) {
 
     if(audioDevice_.getDeviceCount() < 1) {
         std::cout << "No audio devices found" << std::endl;
@@ -69,6 +70,12 @@ int32_t AudioEngine::audioCallback(void* outputBuffer, void* inputBuffer, uint32
 
 int32_t AudioEngine::process(float* out, size_t nFrames) {
 
+    NoteEvent noteEvent;
+    while(noteQueue_->pop(noteEvent)) {
+        std::string msg = "[NoteEvent] Type: " + std::to_string(noteEvent.type) +" Velocity: " + std::to_string(noteEvent.velocity) + " Note:" + std::to_string(noteEvent.note);
+        logger_->log("Audio", LogFlag::Debug, msg);
+    }
+
     for(size_t i = 0; i < nFrames; i++) {
 
         // simulate a sine wave

src/synth/AudioEngine.hpp

@@ -6,6 +6,8 @@
 #include <RtAudio.h>
 
 #include "LoggerService.hpp"
+#include "ConfigService.hpp"
+#include "NoteQueue.hpp"
 
 
 #if defined(_WIN32)
@@ -18,7 +20,7 @@ class AudioEngine {
 
 public:
 
-    AudioEngine(LoggerService* logger);
+    AudioEngine(ConfigService* config, LoggerService* logger, NoteQueue* noteQueue);
     ~AudioEngine();
 
     bool start();
@@ -40,5 +42,7 @@ private:
     float phase_ = 0.0f;
 
     LoggerService* logger_;
+    ConfigService* config_;
+    NoteQueue* noteQueue_;
 
 };

src/synth/KeyboardController.cpp

@@ -5,6 +5,10 @@
 // #include <yaml-cpp/yaml.h>
 #include <filesystem>
 
+KeyboardController::KeyboardController(QObject* parent) : QObject(parent) {
+
+}
+
 KeyboardController::KeyboardController(ConfigService* config, LoggerService* logger, NoteQueue* queue) : config_(config), logger_(logger), queue_(queue) {
 
     // load keymap from config service
@@ -15,11 +19,10 @@ KeyboardController::KeyboardController(ConfigService* config, LoggerService* log
 
 }
 
-void KeyboardController::handleKeyPress(QKeyEvent* e) {
+void KeyboardController::keyDownEvent(int key, int modifiers, const QString& text) {
-    if (e->isAutoRepeat()) return;
 
-    auto it = keymap_.find(e->key());
+    auto it = configuration_.keymap.find(key);
-    if (it == keymap_.end()) return;
+    if (it == configuration_.keymap.end()) return;
 
     queue_->push({
         NoteEventType::NoteOn,
@@ -27,13 +30,13 @@ void KeyboardController::handleKeyPress(QKeyEvent* e) {
         0.8f,
         std::chrono::high_resolution_clock::now()
     });
+
 }
 
-void KeyboardController::handleKeyRelease(QKeyEvent* e) {
+void KeyboardController::keyUpEvent(int key, int modifiers, const QString& text) {
-    if (e->isAutoRepeat()) return;
 
-    auto it = keymap_.find(e->key());
+    auto it = configuration_.keymap.find(key);
-    if (it == keymap_.end()) return;
+    if (it == configuration_.keymap.end()) return;
 
     queue_->push({
         NoteEventType::NoteOff,

src/synth/KeyboardController.hpp

@@ -2,6 +2,7 @@
 // the keyboard controller acts as an instrument input device for creating note events from a computer keyboard
 #pragma once
 
+#include <QObject>
 #include <QKeyEvent>
 #include <unordered_map>
 
@@ -10,14 +11,17 @@
 #include "LoggerService.hpp"
 
 // The keyboardcontroller handles user inputs from a keyboard and maps them to note events
-class KeyboardController {
+class KeyboardController : public QObject {
+
+    Q_OBJECT
     
 public:
-    explicit KeyboardController(ConfigService* config, LoggerService* logger, NoteQueue* queue);
+    explicit KeyboardController(QObject* parent = nullptr);
+    KeyboardController(ConfigService* config, LoggerService* logger, NoteQueue* queue);
     ~KeyboardController() = default;
 
-    void handleKeyPress(QKeyEvent* e);
+    Q_INVOKABLE void keyDownEvent(int key, int modifiers, const QString& text);
-    void handleKeyRelease(QKeyEvent* e);
+    Q_INVOKABLE void keyUpEvent(int key, int modifiers, const QString& text);
 
 private:
 
@@ -26,8 +30,6 @@ private:
     LoggerService* logger_;
 
     // keymap is key -> midi note id
-    std::unordered_map<int32_t, uint8_t> keymap_;
-
     KeymapConfig configuration_;
 
 };

src/synth/NoteQueue.hpp

@@ -9,8 +9,8 @@
 
 #define SYNTH_NOTE_QUEUE_SIZE 128
 
-enum class NoteEventType {
+enum NoteEventType {
-    NoteOn,
+    NoteOn = 0,
     NoteOff
 };
 

ui/Main.qml

@@ -30,4 +30,23 @@ ApplicationWindow {
         }
     }
 
+    Item {
+        anchors.fill: parent
+        focus: true
+
+        Keys.onPressed: (event) => {
+            if(!event.isAutoRepeat) {
+                keyboardController.keyDownEvent(event.key, event.modifiers, event.text)
+                event.accepted = true
+            }
+        }
+
+        Keys.onReleased: (event) => {
+            if(!event.isAutoRepeat) {
+                keyboardController.keyUpEvent(event.key, event.modifiers, event.text)
+                event.accepted = true
+            }
+        }
+    }
+
 }