Improved performance by reducing signals emitted for sound

nescorelib/emu/apu.cpp

@@ -468,7 +468,7 @@ void Apu::updatePlayback()
         audioDcY = m_lowPassFilter.doFiltering(audioDcY);// 14 KHz
         audioDcY = std::clamp(audioDcY, double(-EmuSettings::Audio::internalPeekLimit), double(EmuSettings::Audio::internalPeekLimit));
 
-        Q_EMIT sampleFinished(audioDcY);
+        m_samples.append(audioDcY);
 
         m_audioY = 0;
         m_audioYClocks = 0;
@@ -499,9 +499,11 @@ void Apu::readState(QDataStream &dataStream)
     m_dmc.apuDmcReadState(dataStream);
 }
 
-void Apu::setTimer(double timer)
+void Apu::flush()
 {
-    m_timer = timer;
+    m_timer = 0;
+    Q_EMIT samplesFinished(m_samples);
+    m_samples.clear();
 }
 
 bool Apu::oddCycle() const

nescorelib/emu/apu.h

@@ -56,7 +56,7 @@ public:
     void writeState(QDataStream &dataStream) const;
     void readState(QDataStream &dataStream);
 
-    void setTimer(double timer);
+    void flush();
 
     bool oddCycle() const;
 
@@ -92,7 +92,7 @@ public:
     static const std::array<quint8, 32> m_sqDurationTable;
 
 Q_SIGNALS:
-    void sampleFinished(qint32 sample);
+    void samplesFinished(const QVector<qint32> &samples);
 
 private:
     NesEmulator &m_emu;
@@ -145,5 +145,6 @@ private:
 
     bool m_inputStrobe {};
 
+    QVector<qint32> m_samples;
     qint32 m_sampleRate { 44100 };
 };

nescorelib/nesemulator.cpp

@@ -178,6 +178,6 @@ const Ppu &NesEmulator::ppu() const
 
 void NesEmulator::frameFinished()
 {
-    m_apu.setTimer(0.);
+    m_apu.flush();
     m_frameFinished = true;
 }

nesemu/main.cpp

@@ -45,20 +45,21 @@ int main(int argc, char **argv)
 
     // Audio recorder
     WaveRecorder recorder(1, emulator.apu().sampleRate(), "sound.wav");
-    QObject::connect(&emulator.apu(), &Apu::sampleFinished, &recorder, &WaveRecorder::addSample);
+    QObject::connect(&emulator.apu(), &Apu::samplesFinished, &recorder, &WaveRecorder::addSamples);
 
     // Live audio playback
     FifoStream stream;
-    QObject::connect(&emulator.apu(), &Apu::sampleFinished, [&stream](qint32 sample){
+    QObject::connect(&emulator.apu(), &Apu::samplesFinished, [&stream](const QVector<qint32> &samples){
         QByteArray buf;
-        buf.reserve(sizeof(qint32));
+        buf.reserve(samples.size() * sizeof(qint32));
 
         QDataStream dataStream(&buf, QIODevice::WriteOnly);
         dataStream.setByteOrder(QDataStream::BigEndian);
 
-        dataStream << sample;
+        for(auto sample : samples)
+            dataStream << sample;
 
-        Q_ASSERT(buf.size() == sizeof(qint32));
+        Q_ASSERT(buf.size() == samples.size() * sizeof(qint32));
 
         stream.write(buf);
     });