Add a Balance section to the StringVoice

- Human Voice and Strings levels, one per section, so the two can be
  balanced without re-tuning each register's footage

- Sits below the Strings section, where the hardware keeps it

- Both default to full, leaving existing projects as they were

Author: juzzlin

CHANGELOG

@@ -5,6 +5,11 @@ Release date:
 
 New features:
 
+* Add a Balance section to the StringVoice, below the Strings section
+  - Human Voice and Strings levels, one per section, so the two can be
+    balanced without re-tuning each register's footage
+  - Both default to full, leaving existing projects as they were
+
 * Add the Tube Stage effect
   - Valve preamp with a Bias control for the operating point, which is what
     decides how much even-harmonic warmth the stage generates

src/CMakeLists.txt

@@ -107,6 +107,7 @@ set(QML_SOURCE_FILES
     ${QML_BASE_DIR}/Dialogs/StringEnsembleDialog_Global.qml
     ${QML_BASE_DIR}/Dialogs/StringEnsembleDialog_Registers.qml
     ${QML_BASE_DIR}/Dialogs/StringVoiceDialog.qml
+    ${QML_BASE_DIR}/Dialogs/StringVoiceDialog_Balance.qml
     ${QML_BASE_DIR}/Dialogs/StringVoiceDialog_Ensemble.qml
     ${QML_BASE_DIR}/Dialogs/StringVoiceDialog_Global.qml
     ${QML_BASE_DIR}/Dialogs/StringVoiceDialog_Strings.qml

src/common/constants.cpp

@@ -2042,11 +2042,21 @@ QString xmlKeyFftRate()
     return "fftRate";
 }
 
+QString xmlKeyStringsBalance()
+{
+    return "stringsBalance";
+}
+
 QString xmlKeyStringsLevel8()
 {
     return "stringsLevel8";
 }
 
+QString xmlKeyVoiceBalance()
+{
+    return "voiceBalance";
+}
+
 QString xmlKeyStringsLevel4()
 {
     return "stringsLevel4";

src/common/constants.hpp

@@ -416,6 +416,7 @@ QString xmlKeyPreDelay();
 QString xmlKeyVoiceDepth();
 QString xmlKeyPortamento();
 QString xmlKeyPanSpread();
+QString xmlKeyVoiceBalance();
 QString xmlKeyPitchBendRange();
 QString xmlKeyResonance();
 QString xmlKeyKeyTrack();
@@ -591,6 +592,7 @@ QString xmlValueSynths();
 QString xmlValueMixers();
 QString xmlValueDrums();
 
+QString xmlKeyStringsBalance();
 QString xmlKeyStringsLevel8();
 QString xmlKeyStringsLevel4();
 QString xmlKeyStringsAttack();

src/domain/devices/string_voice_device.cpp

@@ -59,6 +59,9 @@ void StringVoiceDevice::Voice::reset()
 StringVoiceDevice::StringVoiceDevice(std::string name)
   : m_name { std::move(name) }
 {
+    addParameter(Parameter { Constants::NahdXml::xmlKeyStringsBalance().toStdString(), 1.0f, 0, 100, 100, 100 });
+    addParameter(Parameter { Constants::NahdXml::xmlKeyVoiceBalance().toStdString(), 1.0f, 0, 100, 100, 100 });
+
     addParameter(Parameter { Constants::NahdXml::xmlKeyStringsLevel8().toStdString(), 0.8f, 0, 100, 80, 100 });
     addParameter(Parameter { Constants::NahdXml::xmlKeyStringsLevel4().toStdString(), 0.0f, 0, 100, 0, 100 });
     addParameter(Parameter { Constants::NahdXml::xmlKeyStringsAttack().toStdString(), 0.2f, 0, 100, 20, 100 });
@@ -444,9 +447,9 @@ void StringVoiceDevice::processAudio(AudioContext & context)
 
             const double voiceGain { static_cast<double>(v.velocity) * linearGainInternal() * 0.25 * polyphonyGain };
 
-            const double strSample { (strSample8 * m_stringsLevel8 + strSample4 * m_stringsLevel4) * strEnv * voiceGain };
-            const double maleSample { (vocSample8 * m_voiceMale8 + vocSample4 * m_voiceMale4) * vocEnv * voiceGain };
-            const double femaleSample { (vocSample8 * m_voiceFemale8 + vocSample4 * m_voiceFemale4) * vocEnv * voiceGain };
+            const double strSample { (strSample8 * m_stringsLevel8 + strSample4 * m_stringsLevel4) * strEnv * voiceGain * m_stringsBalance };
+            const double maleSample { (vocSample8 * m_voiceMale8 + vocSample4 * m_voiceMale4) * vocEnv * voiceGain * m_voiceBalance };
+            const double femaleSample { (vocSample8 * m_voiceFemale8 + vocSample4 * m_voiceFemale4) * vocEnv * voiceGain * m_voiceBalance };
 
             stringsSumL += strSample * (1.0 - v.pan);
             stringsSumR += strSample * v.pan;
@@ -597,6 +600,26 @@ void StringVoiceDevice::deserializeFromXml(ProjectReader & reader)
 }
 
 // Getters and Setters implementation
+float StringVoiceDevice::stringsBalance() const
+{
+    return m_stringsBalance;
+}
+
+void StringVoiceDevice::setStringsBalance(float val)
+{
+    setContinuousParameterValue(Constants::NahdXml::xmlKeyStringsBalance().toStdString(), val);
+}
+
+float StringVoiceDevice::voiceBalance() const
+{
+    return m_voiceBalance;
+}
+
+void StringVoiceDevice::setVoiceBalance(float val)
+{
+    setContinuousParameterValue(Constants::NahdXml::xmlKeyVoiceBalance().toStdString(), val);
+}
+
 float StringVoiceDevice::stringsLevel8() const
 {
     return m_stringsLevel8;
@@ -814,6 +837,12 @@ void StringVoiceDevice::syncParameters()
 
     Device::syncParameters();
 
+    if (const auto p = parameter(Constants::NahdXml::xmlKeyStringsBalance().toStdString()); p) {
+        m_stringsBalance = p->get().value();
+    }
+    if (const auto p = parameter(Constants::NahdXml::xmlKeyVoiceBalance().toStdString()); p) {
+        m_voiceBalance = p->get().value();
+    }
     if (const auto p = parameter(Constants::NahdXml::xmlKeyStringsLevel8().toStdString()); p) {
         m_stringsLevel8 = p->get().value();
     }

src/domain/devices/string_voice_device.hpp

@@ -63,6 +63,12 @@ class StringVoiceDevice : public Device
     void deserializeFromXml(ProjectReader & reader) override;
 
     // Getters and Setters for Parameters
+    float stringsBalance() const;
+    void setStringsBalance(float val);
+
+    float voiceBalance() const;
+    void setVoiceBalance(float val);
+
     float stringsLevel8() const;
     void setStringsLevel8(float val);
 
@@ -164,6 +170,11 @@ class StringVoiceDevice : public Device
     uint64_t m_nextTriggerId { 1 };
 
     // Device Parameters cache
+    //! Section balance, the hardware's own Balance sliders: one level per section, so a patch can
+    //! be tipped between strings and voices without touching each register's footage.
+    float m_stringsBalance { 1.0f };
+    float m_voiceBalance { 1.0f };
+
     float m_stringsLevel8 { 0.8f };
     float m_stringsLevel4 { 0.0f };
     float m_stringsAttack { 50.0f };

src/unit_tests/string_voice_test/string_voice_test.cpp

@@ -232,6 +232,8 @@ void StringVoiceTest::test_serialization_shouldRestoreParameters()
     {
         NahdXmlWriter writer { buffer };
         StringVoiceDevice dev { "Test StringVoice" };
+        dev.setStringsBalance(0.35f);
+        dev.setVoiceBalance(0.65f);
         dev.setStringsLevel8(0.45f);
         dev.setStringsLevel4(0.6f);
         dev.setVoiceMale4(0.3f);
@@ -258,6 +260,8 @@ void StringVoiceTest::test_serialization_shouldRestoreParameters()
 
         dev.deserializeFromXml(reader);
 
+        QCOMPARE(dev.stringsBalance(), 0.35f);
+        QCOMPARE(dev.voiceBalance(), 0.65f);
         QCOMPARE(dev.stringsLevel8(), 0.45f);
         QCOMPARE(dev.stringsLevel4(), 0.6f);
         QCOMPARE(dev.voiceMale4(), 0.3f);
@@ -412,6 +416,48 @@ void StringVoiceTest::test_voiceRegisters_shouldRouteMale4AndFemale8Independentl
     QCOMPARE(renderPeak(silentDev), 0.0);
 }
 
+void StringVoiceTest::test_balance_shouldScaleEachSectionIndependently()
+{
+    // One level per section, the hardware's Balance sliders. Turning one down must not touch the
+    // other, which is the whole point of not having to reach for each register's footage.
+    const auto render = [](float stringsBalance, float voiceBalance) {
+        StringVoiceDevice dev { "Test StringVoice" };
+        dev.setSampleRate(44100);
+        dev.setStringsLevel8(1.0f);
+        dev.setVoiceMale8(1.0f);
+        dev.setStringsAttack(0.0f);
+        dev.setVoiceAttack(0.0f);
+        dev.setEnsembleEnabled(false);
+        dev.setStringsBalance(stringsBalance);
+        dev.setVoiceBalance(voiceBalance);
+        dev.processMidiNoteOn(48, 100);
+
+        constexpr uint32_t frameCount { 8192 };
+        std::vector<double> buffer(static_cast<size_t>(frameCount) * 2, 0.0);
+        auto ctx = makeContext(buffer, frameCount);
+        dev.processAudio(ctx);
+        return buffer;
+    };
+
+    const double both { rmsLevel(render(1.0f, 1.0f)) };
+    const double stringsOnly { rmsLevel(render(1.0f, 0.0f)) };
+    const double voiceOnly { rmsLevel(render(0.0f, 1.0f)) };
+    const double neither { rmsLevel(render(0.0f, 0.0f)) };
+
+    QVERIFY(both > 0.0);
+    QVERIFY2(stringsOnly > 0.0 && voiceOnly > 0.0,
+             QString("A section fell silent with its own balance up: strings %1, voice %2").arg(stringsOnly).arg(voiceOnly).toUtf8().constData());
+    QVERIFY2(neither < both * 0.001,
+             QString("Both balances down still gave %1 against %2").arg(neither).arg(both).toUtf8().constData());
+    QVERIFY(stringsOnly < both);
+    QVERIFY(voiceOnly < both);
+
+    // Half of the strings section must land halfway in level, not somewhere the voice section moved.
+    const double halfStrings { rmsLevel(render(0.5f, 0.0f)) };
+    QVERIFY2(std::abs(halfStrings - stringsOnly * 0.5) < stringsOnly * 0.05,
+             QString("Half balance gave %1, expected about %2").arg(halfStrings).arg(stringsOnly * 0.5).toUtf8().constData());
+}
+
 void StringVoiceTest::test_formants_male_shouldPeakAtOohFrequencies()
 {
     // The male register sings an /u/: F1 325, F2 700, F3 2530 Hz. F3 is the one that decides whether

src/unit_tests/string_voice_test/string_voice_test.hpp

@@ -36,6 +36,7 @@ private slots:
     void test_vibrato_shouldModulatePitchWithinASingleBuffer();
     void test_ensembleMode_shouldSupportChorusIPlusII();
     void test_voiceRegisters_shouldRouteMale4AndFemale8Independently();
+    void test_balance_shouldScaleEachSectionIndependently();
     void test_formants_male_shouldPeakAtOohFrequencies();
     void test_formants_female_shouldNotNotchBetweenPeaks();
     void test_voiceStealing_shouldRemainStableWhenOversubscribed();

src/view/controllers/string_voice_controller.cpp

@@ -45,6 +45,30 @@ bool StringVoiceController::setDevice(DeviceS device)
     return false;
 }
 
+int StringVoiceController::stringsBalance() const
+{
+    return m_device ? static_cast<int>(std::round(m_device->stringsBalance() * Constants::uiInternalScaling())) : 0;
+}
+
+void StringVoiceController::setStringsBalance(int value)
+{
+    if (m_device) {
+        m_device->setStringsBalance(static_cast<float>(value) / Constants::uiInternalScaling());
+    }
+}
+
+int StringVoiceController::voiceBalance() const
+{
+    return m_device ? static_cast<int>(std::round(m_device->voiceBalance() * Constants::uiInternalScaling())) : 0;
+}
+
+void StringVoiceController::setVoiceBalance(int value)
+{
+    if (m_device) {
+        m_device->setVoiceBalance(static_cast<float>(value) / Constants::uiInternalScaling());
+    }
+}
+
 int StringVoiceController::stringsLevel8() const
 {
     return m_device ? static_cast<int>(std::round(m_device->stringsLevel8() * Constants::uiInternalScaling())) : 0;
@@ -287,6 +311,8 @@ void StringVoiceController::setPanSpread(int value)
 
 void StringVoiceController::requestSettings()
 {
+    emit stringsBalanceChanged();
+    emit voiceBalanceChanged();
     emit stringsLevel8Changed();
     emit stringsLevel4Changed();
     emit stringsAttackChanged();

src/view/controllers/string_voice_controller.hpp

@@ -27,6 +27,9 @@ class StringVoiceController : public DeviceController
 {
     Q_OBJECT
 
+    Q_PROPERTY(int stringsBalance READ stringsBalance WRITE setStringsBalance NOTIFY stringsBalanceChanged)
+    Q_PROPERTY(int voiceBalance READ voiceBalance WRITE setVoiceBalance NOTIFY voiceBalanceChanged)
+
     Q_PROPERTY(int stringsLevel8 READ stringsLevel8 WRITE setStringsLevel8 NOTIFY stringsLevel8Changed)
     Q_PROPERTY(int stringsLevel4 READ stringsLevel4 WRITE setStringsLevel4 NOTIFY stringsLevel4Changed)
     Q_PROPERTY(int stringsAttack READ stringsAttack WRITE setStringsAttack NOTIFY stringsAttackChanged)
@@ -60,6 +63,12 @@ class StringVoiceController : public DeviceController
     DeviceS device() const override;
     bool setDevice(DeviceS device) override;
 
+    int stringsBalance() const;
+    void setStringsBalance(int value);
+
+    int voiceBalance() const;
+    void setVoiceBalance(int value);
+
     int stringsLevel8() const;
     void setStringsLevel8(int value);
 
@@ -124,6 +133,8 @@ class StringVoiceController : public DeviceController
 
 signals:
     void deviceChanged();
+    void stringsBalanceChanged();
+    void voiceBalanceChanged();
     void stringsLevel8Changed();
     void stringsLevel4Changed();
     void stringsAttackChanged();