nonfunctional flailing

notes

@@ -40,7 +40,10 @@ TODO {
         }
     }
     
-    - ping-pong for delay
+    filter cutoff preset for knobgadget
+    force at least 1hz in svfilter for normalization
+    
+    x retool audio engine for active push
     
     revert-to-saved menu action
     

xybrid/audio/audioengine.cpp

@@ -107,10 +107,12 @@ void AudioEngine::initAudio(bool startNow) {
         output.reset(new QAudioOutput(deviceInfo, format));
         output->setCategory("Xybrid");
         output->setObjectName("Xybrid"); // if Qt ever implements naming the stream this way, WE'LL BE READY
-        output->setBufferSize(static_cast<int>(sampleRate*4*( 64.0 )/1000.0)); // 64ms seems to be a sweet spot now
+        //output->setBufferSize(static_cast<int>(sampleRate*4*( 64.0 )/1000.0)); // 64ms seems to be a sweet spot now
+
+        connect(output.get(), &QAudioOutput::notify, this, &AudioEngine::processActive);
     }
 
-    if (startNow) output->start();
+    if (startNow) startOutput();
 }
 
 void AudioEngine::deinitAudio() {
@@ -124,6 +126,23 @@ void AudioEngine::deinitAudio() {
     }
 }
 
+void AudioEngine::startOutput() {
+    if (!output) return;
+    if (activeBuffering) {
+        outBuf.resize(static_cast<size_t>(4*5*sampleRate/1000));
+        output->setBufferSize(sampleRate*4*(bufferMs+250)/1000); // allocate extra buffer for safety
+        output->setNotifyInterval(std::max(1, bufferMs/2));
+        outStream = output->start();
+        bufferFill = output->notifyInterval();
+        assert(bufferFill > 0);
+    } else {
+        outBuf.resize(0);
+        output->setNotifyInterval(0); // don't need this here
+        output->setBufferSize(sampleRate*4*bufferMs/1000); // set canonical buffer size
+        output->start(this); // set output to take the active role
+    }
+}
+
 void AudioEngine::play(std::shared_ptr<Project> p, int fromPos) {
     QMetaObject::invokeMethod(this, [this, p, fromPos] {
         if (!p) return; // nope
@@ -147,7 +166,7 @@ void AudioEngine::play(std::shared_ptr<Project> p, int fromPos) {
         tempo = project->tempo;
         tickAcc = 0;
 
-        output->start(this);
+        startOutput();
 
         mode = Playing;
         emit this->playbackModeChanged();
@@ -193,7 +212,7 @@ uint16_t AudioEngine::preview(std::shared_ptr<Project> p, int16_t port, int16_t
             }
             tempo = project->tempo;
 
-            output->start(this);
+            startOutput();
             mode = Previewing;
             emit this->playbackModeChanged();
         }
@@ -351,6 +370,23 @@ void AudioEngine::buildQueue() {
     queueValid = true;
 }
 
+void AudioEngine::processActive() {
+    if (!output || !activeBuffering) return;
+    bufferFill -= output->notifyInterval();
+    qint64 needed = (bufferMs - bufferFill) * sampleRate/1000 * 4;
+
+    while (needed > 0) {
+        auto r = readData(&outBuf[0], std::min(needed, static_cast<qint64>(outBuf.size())));
+        outStream->write(&outBuf[0], r);
+        needed -= r;
+        //enc.write(&dat[0], readData(&dat[0], 1024));
+
+    }
+
+    bufferFill = bufferMs;
+    //
+}
+
 qint64 AudioEngine::readData(char *data, qint64 maxlen) {
     const constexpr qint64 smp = 2;
     const constexpr qint64 stride = smp*2;

xybrid/audio/audioengine.h

@@ -53,6 +53,7 @@ namespace Xybrid::Audio {
     private:
         QThread* thread;
         std::unique_ptr<QAudioOutput> output;
+        QIODevice* outStream;
         int sampleRate = 48000;
 
         std::vector<float> buffer[2];
@@ -63,6 +64,11 @@ namespace Xybrid::Audio {
         std::atomic<size_t*> tickBufPtr;
         size_t* tickBufEnd;
 
+        static const constexpr bool activeBuffering = false;//true;
+        int bufferMs = 64;
+        int bufferFill = 0;
+        std::vector<char> outBuf;
+
         PlaybackMode mode = Stopped;
         size_t tickId = 0;
         std::shared_ptr<Data::Project> project;
@@ -95,9 +101,11 @@ namespace Xybrid::Audio {
         void postInit();
         void initAudio(bool startNow = false);
         void deinitAudio();
+        void startOutput();
         Data::Pattern* findPattern(int = 0);
         void nextTick();
         void processNodes();
+
     public:
         static void init();
         inline constexpr PlaybackMode playbackMode() const { return mode; }
@@ -125,6 +133,7 @@ namespace Xybrid::Audio {
         void playbackModeChanged();
 
     public slots:
+        void processActive();
     };
 
     class AudioWorker : public QObject, private AudioWorkerCore {