Added the basic structure for changing the oversampling factor

src/sfizz/Config.h

@@ -24,6 +24,13 @@
 #pragma once
 
 namespace sfz {
+enum class Oversampling: int
+{
+    x1 = 1,
+    x2 = 2,
+    x4 = 4,
+    x8 = 8
+};
 
 namespace config {
     constexpr float defaultSampleRate { 48000 };
@@ -37,7 +44,7 @@ namespace config {
     constexpr float virtuallyZero { 0.00005f };
     constexpr float fastReleaseDuration { 0.01 };
     constexpr char defineCharacter { '$' };
-    constexpr int oversamplingFactor { 2 };
+    constexpr Oversampling defaultOversamplingFactor { Oversampling::x1 };
     constexpr float A440 { 440.0 };
     constexpr unsigned powerHistoryLength { 16 };
     constexpr float voiceStealingThreshold { 0.00001 };

src/sfizz/Region.cpp

@@ -773,3 +773,13 @@ float sfz::Region::velocityCurve(uint8_t velocity) const noexcept
 
     return gain;
 }
+
+void sfz::Region::setOversamplingFactor(sfz::Oversampling factor) noexcept
+{
+    oversamplingFactor = factor;
+}
+
+sfz::Oversampling sfz::Region::getOversamplingFactor() const noexcept
+{
+    return oversamplingFactor;
+}

src/sfizz/Region.h

@@ -49,8 +49,8 @@ namespace sfz {
  *
  */
 struct Region {
-    Region(const MidiState& midiState)
+    Region(const MidiState& midiState, Oversampling factor = config::defaultOversamplingFactor)
-    : midiState(midiState)
+    : midiState(midiState), oversamplingFactor(factor)
     {
         ccSwitched.set();
     }
@@ -238,6 +238,22 @@ struct Region {
      */
     bool parseOpcode(const Opcode& opcode);
 
+    /**
+     * @brief Set the oversampling factor to a new value. This will trigger updates of
+     * all the relevant values (sample ends, loop points, etc). It will also trigger
+     * preloading the file data again.
+     *
+     * @param factor
+     */
+    void setOversamplingFactor(Oversampling factor) noexcept;
+
+    /**
+     * @brief get the current oversampling factor
+     *
+     * @return Oversampling
+     */
+    Oversampling getOversamplingFactor() const noexcept;
+
     // Sound source: sample playback
     std::string sample {}; // Sample
     float delay { Default::delay }; // delay
@@ -338,6 +354,8 @@ private:
     int activeNotesInRange { -1 };
     int sequenceCounter { 0 };
 
+    Oversampling oversamplingFactor { config::defaultOversamplingFactor };
+
     std::uniform_real_distribution<float> volumeDistribution { -sfz::Default::ampRandom, sfz::Default::ampRandom };
     std::uniform_real_distribution<float> delayDistribution { 0, sfz::Default::delayRandom };
     std::uniform_int_distribution<uint32_t> offsetDistribution { 0, sfz::Default::offsetRandom };

src/sfizz/Synth.cpp

@@ -546,3 +546,26 @@ void sfz::Synth::resetVoices(int numVoices)
     voiceViewArray.reserve(numVoices);
     this->numVoices = numVoices;
 }
+
+void sfz::Synth::setOversamplingFactor(sfz::Oversampling factor) noexcept
+{
+    AtomicDisabler callbackDisabler{ canEnterCallback };
+    while (inCallback) {
+        std::this_thread::sleep_for(1ms);
+    }
+
+    resources.filePool.emptyFileLoadingQueue();
+    for (auto& voice: voices)
+        voice->reset();
+
+    for (auto& region: regions) {
+        region->setOversamplingFactor(factor);
+    }
+
+    oversamplingFactor = factor;
+}
+
+sfz::Oversampling sfz::Synth::getOversamplingFactor() const noexcept
+{
+    return oversamplingFactor;
+}

src/sfizz/Synth.h

@@ -279,6 +279,22 @@ public:
      *
      */
     void garbageCollect() noexcept;
+
+    /**
+     * @brief Set the oversampling factor to a new value. This will disable all callbacks
+     * kill all the voices, and trigger a reloading of every file in the FilePool under
+     * the new oversampling.
+     *
+     * @param factor
+     */
+    void setOversamplingFactor(Oversampling factor) noexcept;
+
+    /**
+     * @brief get the current oversampling factor
+     *
+     * @return Oversampling
+     */
+    Oversampling getOversamplingFactor() const noexcept;
 protected:
     /**
      * @brief The parser callback; this is called by the parent object each time
@@ -370,6 +386,7 @@ private:
     float sampleRate { config::defaultSampleRate };
     float volume { Default::volume };
     int numVoices { config::numVoices };
+    Oversampling oversamplingFactor { config::defaultOversamplingFactor };
 
     // Distribution used to generate random value for the *rand opcodes
     std::uniform_real_distribution<float> randNoteDistribution { 0, 1 };