# HG changeset patch
# User Chris Cannam
# Date 1389186442 0
# Node ID 58582119c92a2c23d08cd8847967e3e7f8ec8f27
# Parent  faee60602049197000dc56f8bccec93c9772f113
Add a basic continuous synth implementation (simple sinusoids only, no gaps)

diff -r faee60602049 -r 58582119c92a audioio/AudioGenerator.cpp
--- a/audioio/AudioGenerator.cpp	Wed Jan 08 11:00:12 2014 +0000
+++ b/audioio/AudioGenerator.cpp	Wed Jan 08 13:07:22 2014 +0000
@@ -24,10 +24,12 @@
 #include "data/model/NoteModel.h"
 #include "data/model/FlexiNoteModel.h"
 #include "data/model/DenseTimeValueModel.h"
+#include "data/model/SparseTimeValueModel.h"
 #include "data/model/SparseOneDimensionalModel.h"
 #include "data/model/NoteData.h"
 
 #include "ClipMixer.h"
+#include "ContinuousSynth.h"
 
 #include <iostream>
 #include <cmath>
@@ -118,11 +120,22 @@
 	}
     }
 
-    ClipMixer *mixer = makeClipMixerFor(model);
-    if (mixer) {
-        QMutexLocker locker(&m_mutex);
-        m_clipMixerMap[model] = mixer;
-        return true;
+    if (usesClipMixer(model)) {
+        ClipMixer *mixer = makeClipMixerFor(model);
+        if (mixer) {
+            QMutexLocker locker(&m_mutex);
+            m_clipMixerMap[model] = mixer;
+            return true;
+        }
+    }
+
+    if (usesContinuousSynth(model)) {
+        ContinuousSynth *synth = makeSynthFor(model);
+        if (synth) {
+            QMutexLocker locker(&m_mutex);
+            m_continuousSynthMap[model] = synth;
+            return true;
+        }
     }
 
     return false;
@@ -148,40 +161,24 @@
     }
 }
 
-/*!!!
-void
-AudioGenerator::playPluginConfigurationChanged(const Playable *playable,
-                                               QString configurationXml)
+bool
+AudioGenerator::usesClipMixer(const Model *model)
 {
-//    SVDEBUG << "AudioGenerator::playPluginConfigurationChanged" << endl;
-
-    const Model *model = dynamic_cast<const Model *>(playable);
-    if (!model) {
-        cerr << "WARNING: AudioGenerator::playClipIdChanged: playable "
-                  << playable << " is not a supported model type"
-                  << endl;
-        return;
-    }
-
-    if (m_synthMap.find(model) == m_synthMap.end()) {
-        SVDEBUG << "AudioGenerator::playPluginConfigurationChanged: We don't know about this plugin" << endl;
-        return;
-    }
-
-    RealTimePluginInstance *plugin = m_synthMap[model];
-    if (plugin) {
-        PluginXml(plugin).setParametersFromXml(configurationXml);
-    }
+    bool clip = 
+        (qobject_cast<const SparseOneDimensionalModel *>(model) ||
+         qobject_cast<const NoteModel *>(model) ||
+         qobject_cast<const FlexiNoteModel *>(model));
+    return clip;
 }
 
-void
-AudioGenerator::setSampleDir(RealTimePluginInstance *plugin)
+bool
+AudioGenerator::usesContinuousSynth(const Model *model)
 {
-    if (m_sampleDir != "") {
-        plugin->configure("sampledir", m_sampleDir.toStdString());
-    }
-} 
-*/
+    bool cont = 
+        (qobject_cast<const SparseTimeValueModel *>(model));
+    return cont;
+}
+
 ClipMixer *
 AudioGenerator::makeClipMixerFor(const Model *model)
 {
@@ -221,6 +218,21 @@
     return mixer;
 }
 
+ContinuousSynth *
+AudioGenerator::makeSynthFor(const Model *model)
+{
+    const Playable *playable = model;
+    if (!playable || !playable->canPlay()) return 0;
+
+    ContinuousSynth *synth = new ContinuousSynth(m_targetChannelCount,
+                                                 m_sourceSampleRate,
+                                                 m_processingBlockSize);
+
+    std::cerr << "AudioGenerator::makeSynthFor(" << model << "): created synth" << std::endl;
+
+    return synth;
+}
+
 void
 AudioGenerator::removeModel(Model *model)
 {
@@ -346,14 +358,14 @@
 				      buffer, gain, pan, fadeIn, fadeOut);
     }
 
-    bool synthetic = 
-        (qobject_cast<SparseOneDimensionalModel *>(model) ||
-         qobject_cast<NoteModel *>(model) ||
-         qobject_cast<FlexiNoteModel *>(model));
+    if (usesClipMixer(model)) {
+        return mixClipModel(model, startFrame, frameCount,
+                            buffer, gain, pan);
+    }
 
-    if (synthetic) {
-        return mixSyntheticNoteModel(model, startFrame, frameCount,
-                                     buffer, gain, pan, fadeIn, fadeOut);
+    if (usesContinuousSynth(model)) {
+        return mixContinuousSynthModel(model, startFrame, frameCount,
+                                       buffer, gain, pan);
     }
 
     std::cerr << "AudioGenerator::mixModel: WARNING: Model " << model << " of type " << model->getTypeName() << " is marked as playable, but I have no mechanism to play it" << std::endl;
@@ -457,17 +469,17 @@
 }
   
 size_t
-AudioGenerator::mixSyntheticNoteModel(Model *model,
-                                      size_t startFrame, size_t frames,
-                                      float **buffer, float gain, float pan,
-                                      size_t /* fadeIn */,
-                                      size_t /* fadeOut */)
+AudioGenerator::mixClipModel(Model *model,
+                             size_t startFrame, size_t frames,
+                             float **buffer, float gain, float pan)
 {
     ClipMixer *clipMixer = m_clipMixerMap[model];
     if (!clipMixer) return 0;
 
     size_t blocks = frames / m_processingBlockSize;
     
+    //!!! todo: the below -- it matters
+
     //!!! hang on -- the fact that the audio callback play source's
     //buffer is a multiple of the plugin's buffer size doesn't mean
     //that we always get called for a multiple of it here (because it
@@ -481,7 +493,7 @@
     size_t got = blocks * m_processingBlockSize;
 
 #ifdef DEBUG_AUDIO_GENERATOR
-    cout << "mixModel [synthetic note]: frames " << frames
+    cout << "mixModel [clip]: frames " << frames
 	      << ", blocks " << blocks << endl;
 #endif
 
@@ -524,7 +536,7 @@
                 off.frequency = noteOffs.begin()->frequency;
 
 #ifdef DEBUG_AUDIO_GENERATOR
-		cerr << "mixModel [synthetic]: adding note-off at frame " << eventFrame << " frame offset " << off.frameOffset << " frequency " << off.frequency << endl;
+		cerr << "mixModel [clip]: adding note-off at frame " << eventFrame << " frame offset " << off.frameOffset << " frequency " << off.frequency << endl;
 #endif
 
                 ends.push_back(off);
@@ -537,7 +549,7 @@
             on.pan = pan;
 
 #ifdef DEBUG_AUDIO_GENERATOR
-	    cout << "mixModel [synthetic]: adding note at frame " << noteFrame << ", frame offset " << on.frameOffset << " frequency " << on.frequency << endl;
+	    cout << "mixModel [clip]: adding note at frame " << noteFrame << ", frame offset " << on.frameOffset << " frequency " << on.frequency << endl;
 #endif
 	    
             starts.push_back(on);
@@ -555,7 +567,7 @@
             off.frequency = noteOffs.begin()->frequency;
 
 #ifdef DEBUG_AUDIO_GENERATOR
-            cerr << "mixModel [synthetic]: adding leftover note-off at frame " << eventFrame << " frame offset " << off.frameOffset << " frequency " << off.frequency << endl;
+            cerr << "mixModel [clip]: adding leftover note-off at frame " << eventFrame << " frame offset " << off.frameOffset << " frequency " << off.frequency << endl;
 #endif
 
             ends.push_back(off);
@@ -573,3 +585,70 @@
 
     return got;
 }
+
+size_t
+AudioGenerator::mixContinuousSynthModel(Model *model,
+                                        size_t startFrame,
+                                        size_t frames,
+                                        float **buffer,
+                                        float gain, 
+                                        float pan)
+{
+    ContinuousSynth *synth = m_continuousSynthMap[model];
+    if (!synth) return 0;
+
+    // only type we support here at the moment
+    SparseTimeValueModel *stvm = qobject_cast<SparseTimeValueModel *>(model);
+    if (stvm->getScaleUnits() != "Hz") return 0;
+
+    size_t blocks = frames / m_processingBlockSize;
+
+    //!!! todo: see comment in mixClipModel
+
+    size_t got = blocks * m_processingBlockSize;
+
+#ifdef DEBUG_AUDIO_GENERATOR
+    cout << "mixModel [synth]: frames " << frames
+	      << ", blocks " << blocks << endl;
+#endif
+    
+    float **bufferIndexes = new float *[m_targetChannelCount];
+
+    for (size_t i = 0; i < blocks; ++i) {
+
+	size_t reqStart = startFrame + i * m_processingBlockSize;
+
+	for (size_t c = 0; c < m_targetChannelCount; ++c) {
+            bufferIndexes[c] = buffer[c] + i * m_processingBlockSize;
+        }
+
+        SparseTimeValueModel::PointList points = 
+            stvm->getPoints(reqStart, reqStart + m_processingBlockSize);
+
+        // by default, repeat last frequency
+        float f0 = 0.f;
+
+        // go straight to the last freq that is genuinely in this range
+        for (SparseTimeValueModel::PointList::const_iterator itr = points.end();
+             itr != points.begin(); ) {
+            --itr;
+            if (itr->frame >= reqStart &&
+                itr->frame < reqStart + m_processingBlockSize) {
+                f0 = itr->value;
+                break;
+            }
+        }
+
+        cerr << "f0 = " << f0 << endl;
+
+        synth->mix(bufferIndexes,
+                   gain,
+                   pan,
+                   f0);
+    }
+
+    delete[] bufferIndexes;
+
+    return got;
+}
+
diff -r faee60602049 -r 58582119c92a audioio/AudioGenerator.h
--- a/audioio/AudioGenerator.h	Wed Jan 08 11:00:12 2014 +0000
+++ b/audioio/AudioGenerator.h	Wed Jan 08 13:07:22 2014 +0000
@@ -23,6 +23,7 @@
 class SparseOneDimensionalModel;
 class Playable;
 class ClipMixer;
+class ContinuousSynth;
 
 #include <QObject>
 #include <QMutex>
@@ -122,12 +123,21 @@
     typedef std::multiset<NoteOff, NoteOff::Comparator> NoteOffSet;
     typedef std::map<const Model *, NoteOffSet> NoteOffMap;
 
+    typedef std::map<const Model *, ContinuousSynth *> ContinuousSynthMap;
+
     QMutex m_mutex;
+
     ClipMixerMap m_clipMixerMap;
     NoteOffMap m_noteOffs;
     static QString m_sampleDir;
 
+    ContinuousSynthMap m_continuousSynthMap;
+
+    bool usesClipMixer(const Model *);
+    bool usesContinuousSynth(const Model *);
+
     ClipMixer *makeClipMixerFor(const Model *model);
+    ContinuousSynth *makeSynthFor(const Model *model);
 
     static void initialiseSampleDir();
 
@@ -135,9 +145,13 @@
     (DenseTimeValueModel *model, size_t startFrame, size_t frameCount,
      float **buffer, float gain, float pan, size_t fadeIn, size_t fadeOut);
 
-    virtual size_t mixSyntheticNoteModel
+    virtual size_t mixClipModel
     (Model *model, size_t startFrame, size_t frameCount,
-     float **buffer, float gain, float pan, size_t fadeIn, size_t fadeOut);
+     float **buffer, float gain, float pan);
+
+    virtual size_t mixContinuousSynthModel
+    (Model *model, size_t startFrame, size_t frameCount,
+     float **buffer, float gain, float pan);
     
     static const size_t m_processingBlockSize;
 };
diff -r faee60602049 -r 58582119c92a audioio/ClipMixer.cpp
--- a/audioio/ClipMixer.cpp	Wed Jan 08 11:00:12 2014 +0000
+++ b/audioio/ClipMixer.cpp	Wed Jan 08 13:07:22 2014 +0000
@@ -178,6 +178,8 @@
         }
     }
 
+    delete[] levels;
+
     m_playing = remaining;
 }
 
diff -r faee60602049 -r 58582119c92a audioio/ContinuousSynth.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/audioio/ContinuousSynth.cpp	Wed Jan 08 13:07:22 2014 +0000
@@ -0,0 +1,93 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#include "ContinuousSynth.h"
+
+#include "base/Debug.h"
+
+#include <cmath>
+
+ContinuousSynth::ContinuousSynth(int channels, int sampleRate, int blockSize) :
+    m_channels(channels),
+    m_sampleRate(sampleRate),
+    m_blockSize(blockSize),
+    m_prevF0(-1.f),
+    m_phase(0.0)
+{
+}
+
+ContinuousSynth::~ContinuousSynth()
+{
+}
+
+void
+ContinuousSynth::reset()
+{
+    m_phase = 0;
+}
+
+void
+ContinuousSynth::mix(float **toBuffers, float gain, float pan, float f0)
+{
+    if (f0 == 0.f) f0 = m_prevF0;
+
+    bool wasOn = (m_prevF0 > 0.f);
+    bool nowOn = (f0 > 0.f);
+
+    if (!nowOn && !wasOn) {
+	m_phase = 0;
+	return;
+    }
+
+    int fadeLength = 20; // samples
+
+    float *levels = new float[m_channels];
+    
+    for (int c = 0; c < m_channels; ++c) {
+	levels[c] = gain;
+    }
+    if (pan != 0.0 && m_channels == 2) {
+	levels[0] *= 1.0 - pan;
+	levels[1] *= pan + 1.0;
+    }
+
+    double phasor = (f0 * 2 * M_PI) / m_sampleRate;
+    double p = m_phase;
+
+    cerr << "ContinuousSynth::mix: f0 = " << f0 << " (from " << m_prevF0 << "), phase = " << m_phase << ", phasor = " << phasor << endl;
+
+    for (int i = 0; i < m_blockSize; ++i) {
+
+	p = m_phase + i * phasor;
+	
+	double v = sin(p);
+
+	if (!wasOn && i < fadeLength) { // fade in
+	    v = v * (i / double(fadeLength));
+	} else if (!nowOn) {
+	    if (i > fadeLength) v = 0;
+	    else v = v * (1.0 - (i / double(fadeLength)));
+	}
+
+	for (int c = 0; c < m_channels; ++c) {
+	    toBuffers[c][i] += levels[c] * v;
+	}
+    }	
+
+    m_prevF0 = f0;
+    m_phase = p;
+
+    delete[] levels;
+}
+
diff -r faee60602049 -r 58582119c92a audioio/ContinuousSynth.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/audioio/ContinuousSynth.h	Wed Jan 08 13:07:22 2014 +0000
@@ -0,0 +1,61 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#ifndef CONTINUOUS_SYNTH_H
+#define CONTINUOUS_SYNTH_H
+
+/**
+ * Mix into a target buffer a signal synthesised so as to sound at a
+ * specific frequency. The frequency may change with each processing
+ * block, or may be switched on or off.
+ */
+
+class ContinuousSynth
+{
+public:
+    ContinuousSynth(int channels, int sampleRate, int blockSize);
+    ~ContinuousSynth();
+    
+    void setChannelCount(int channels);
+
+    void reset();
+
+    /**
+     * Mix in a signal to be heard at the given fundamental
+     * frequency. Any oscillator state will be maintained between
+     * process calls so as to provide a continuous sound. The f0 value
+     * may vary between calls.
+     *
+     * Supply f0 equal to 0 if you want to maintain the f0 from the
+     * previous block (without having to remember what it was).
+     *
+     * Supply f0 less than 0 for silence. You should continue to call
+     * this even when the signal is silent if you want to ensure the
+     * sound switches on and off cleanly.
+     */
+    void mix(float **toBuffers,
+	     float gain,
+	     float pan,
+	     float f0);
+
+private:
+    int m_channels;
+    int m_sampleRate;
+    int m_blockSize;
+
+    double m_prevF0;
+    double m_phase;
+};
+
+#endif
diff -r faee60602049 -r 58582119c92a svapp.pro
--- a/svapp.pro	Wed Jan 08 11:00:12 2014 +0000
+++ b/svapp.pro	Wed Jan 08 13:07:22 2014 +0000
@@ -36,6 +36,7 @@
            audioio/AudioPulseAudioTarget.h \
            audioio/AudioTargetFactory.h \
            audioio/ClipMixer.h \
+           audioio/ContinuousSynth.h \
            audioio/PlaySpeedRangeMapper.h
 
 SOURCES += audioio/AudioCallbackPlaySource.cpp \
@@ -47,6 +48,7 @@
            audioio/AudioPulseAudioTarget.cpp \
            audioio/AudioTargetFactory.cpp \
            audioio/ClipMixer.cpp \
+           audioio/ContinuousSynth.cpp \
            audioio/PlaySpeedRangeMapper.cpp
 
 HEADERS += framework/Document.h \