Add support for opcodes lotimer/hitimer

While not widely supported or well documented, is very useful especially when
triggering a note with on_locc/on_hicc to prevent a bunch of retriggers.

The region will trigger as long as the elapsed time from the note-on of the most recently triggered region in
the current polyphony group is between lotimer and hitimer amount of seconds. lotimer default 0, hitimer default is
max_float.

Example use: to preventing a region from retriggering too quickly, set lotimer=0.1

src/sfizz/Defaults.cpp

@@ -199,6 +199,8 @@ FloatSpec lofiDecim { 0.0f, {0.0f, 100.0f}, 0 };
 FloatSpec rectify { 0.0f, {0.0f, 100.0f}, 0 };
 UInt32Spec stringsNumber { maxStrings, {0, maxStrings}, 0 };
 BoolSpec sustainCancelsRelease { false, {0, 1}, kEnforceBounds };
+FloatSpec loTimer { 0.0f, {0.0f, float_max}, 0 };
+FloatSpec hiTimer { float_max, {0.0f, float_max}, 0 };
 
 ESpec<Trigger> trigger { Trigger::attack, {Trigger::attack, Trigger::release_key}, 0};
 ESpec<CrossfadeCurve> crossfadeCurve { CrossfadeCurve::power, {CrossfadeCurve::gain, CrossfadeCurve::power}, 0};

src/sfizz/Defaults.h

@@ -317,6 +317,8 @@ namespace Default
     extern const OpcodeSpec<FilterType> filter;
     extern const OpcodeSpec<EqType> eq;
     extern const OpcodeSpec<bool> sustainCancelsRelease;
+    extern const OpcodeSpec<float> loTimer;
+    extern const OpcodeSpec<float> hiTimer;
 
     // Default/max count for objects
     constexpr int numEQs { 3 };

src/sfizz/MidiState.h

@@ -165,6 +165,12 @@ public:
      */
     void advanceTime(int numSamples) noexcept;
 
+    /**
+     * @brief Returns current internal sample clock
+     *
+     */
+    unsigned getInternalClock() const noexcept { return internalClock; }
+
     /**
      * @brief Flush events in all states, keeping only the last one as the "base" state
      *

src/sfizz/PolyphonyGroup.cpp

@@ -15,6 +15,7 @@ void sfz::PolyphonyGroup::registerVoice(Voice* voice) noexcept
 {
     if (absl::c_find(voices, voice) == voices.end())
         voices.push_back(voice);
+    mostRecentStartStamp_ = voice->getStartTimestampSamples();
 }
 
 void sfz::PolyphonyGroup::removeVoice(const Voice* voice) noexcept

src/sfizz/PolyphonyGroup.h

@@ -62,9 +62,15 @@ public:
      * @return std::vector<Voice*>&
      */
     std::vector<Voice*>& getActiveVoices() noexcept { return voices; }
+    /**
+     * @brief Returns the start timestamp in samples of the most recently activated voice
+     */
+    unsigned getMostRecentStartTimestamp() const noexcept { return mostRecentStartStamp_; }
+
 private:
     unsigned polyphonyLimit { config::maxVoices };
     std::vector<Voice*> voices;
+    unsigned mostRecentStartStamp_ { 0 };
 };
 
 }

src/sfizz/Region.cpp

@@ -562,6 +562,15 @@ bool sfz::Region::parseOpcode(const Opcode& rawOpcode, bool cleanOpcode)
         groupVolume = opcode.read(Default::volume);
         break;
 
+    case hash("lotimer"):
+        timerRange.setStart(opcode.read(Default::loTimer));
+        useTimerRange = useTimerRange || timerRange.getStart() != Default::loTimer;
+        break;
+    case hash("hitimer"):
+        timerRange.setEnd(opcode.read(Default::hiTimer));
+        useTimerRange = useTimerRange || timerRange.getEnd() != Default::hiTimer;
+        break;
+
     // Performance parameters: filters
     case hash("cutoff&"): // also cutoff
         {

src/sfizz/Region.h

@@ -335,6 +335,8 @@ struct Region {
     CCMap<UncheckedRange<float>> crossfadeCCInRange { Default::crossfadeCCInRange }; // xfin_loccN xfin_hiccN
     CCMap<UncheckedRange<float>> crossfadeCCOutRange { Default::crossfadeCCOutRange }; // xfout_loccN xfout_hiccN
     float rtDecay { Default::rtDecay }; // rt_decay
+    UncheckedRange<float> timerRange { Default::loTimer, Default::hiTimer }; // hitimer and lotimer (seconds)
+    bool useTimerRange { false }; // to optimize having to check the timer range, because this is very rare opcode
 
     float globalAmplitude { 1.0 }; // global_amplitude
     float masterAmplitude { 1.0 }; // master_amplitude

src/sfizz/Synth.cpp

@@ -1353,6 +1353,7 @@ void Synth::Impl::noteOnDispatch(int delay, int noteNumber, float velocity) noex
 {
     const auto randValue = randNoteDistribution_(Random::randomGenerator);
     SisterVoiceRingBuilder ring;
+    MidiState& midiState = resources_.getMidiState();
 
     if (!lastKeyswitchLists_[noteNumber].empty()) {
         if (currentSwitch_ && *currentSwitch_ != noteNumber) {
@@ -1374,6 +1375,9 @@ void Synth::Impl::noteOnDispatch(int delay, int noteNumber, float velocity) noex
     for (Layer* layer : noteActivationLists_[noteNumber]) {
         if (layer->registerNoteOn(noteNumber, velocity, randValue)) {
             const Region& region = layer->getRegion();
+            if (region.useTimerRange && !voiceManager_.withinValidTimerRange(&region, midiState.getInternalClock() + delay, sampleRate_))
+                continue;
+
             checkOffGroups(&region, delay, noteNumber);
             TriggerEvent triggerEvent { TriggerEventType::NoteOn, noteNumber, velocity };
             startVoice(layer, delay, triggerEvent, ring);
@@ -1430,6 +1434,7 @@ void Synth::Impl::ccDispatch(int delay, int ccNumber, float value) noexcept
     SisterVoiceRingBuilder ring;
     TriggerEvent triggerEvent { TriggerEventType::CC, ccNumber, value };
     const auto randValue = randNoteDistribution_(Random::randomGenerator);
+    MidiState& midiState = resources_.getMidiState();
     for (Layer* layer : ccActivationLists_[ccNumber]) {
         const Region& region = layer->getRegion();
 
@@ -1448,6 +1453,9 @@ void Synth::Impl::ccDispatch(int delay, int ccNumber, float value) noexcept
         }
 
         if (layer->registerCC(ccNumber, value, randValue)) {
+            if (region.useTimerRange && ! voiceManager_.withinValidTimerRange(&region, midiState.getInternalClock() + delay, sampleRate_))
+                continue;
+
             checkOffGroups(&region, delay, ccNumber);
             startVoice(layer, delay, triggerEvent, ring);
         }

src/sfizz/SynthMessaging.cpp

@@ -730,6 +730,14 @@ void sfz::Synth::dispatchMessage(Client& client, int delay, const char* path, co
             }
         } break;
 
+        MATCH("/region&/timer_range", "") {
+            GET_REGION_OR_BREAK(indices[0])
+            sfizz_arg_t args[2];
+            args[0].f = region.timerRange.getStart();
+            args[1].f = region.timerRange.getEnd();
+            client.receive(delay, path, "ff", args);
+        } break;
+
         MATCH("/region&/position", "") {
             GET_REGION_OR_BREAK(indices[0])
             client.receive<'f'>(delay, path, region.position * 100.0f);

src/sfizz/Voice.cpp

@@ -262,6 +262,7 @@ struct Voice::Impl
 
     int samplesPerBlock_ { config::defaultSamplesPerBlock };
     float sampleRate_ { config::defaultSampleRate };
+    unsigned startTimestamp_ { 0 };
 
     Resources& resources_;
 
@@ -429,14 +430,18 @@ bool Voice::startVoice(Layer* layer, int delay, const TriggerEvent& event) noexc
         return false;
     }
 
-    impl.switchState(State::playing);
-
-    impl.updateExtendedCCValues();
-
     ASSERT(delay >= 0);
     if (delay < 0)
         delay = 0;
 
+    impl.triggerDelay_ = delay;
+    impl.initialDelay_ = delay + static_cast<int>(regionDelay(region, midiState) * impl.sampleRate_);
+    impl.startTimestamp_ = midiState.getInternalClock() + impl.initialDelay_; // need to set this before switchState
+
+    impl.switchState(State::playing);
+
+    impl.updateExtendedCCValues();
+
     if (region.isOscillator()) {
         WavetablePool& wavePool = resources.getWavePool();
         const WavetableMulti* wave = nullptr;
@@ -510,8 +515,6 @@ bool Voice::startVoice(Layer* layer, int delay, const TriggerEvent& event) noexc
         impl.equalizers_[i].setup(region, i, impl.triggerEvent_.value);
     }
 
-    impl.triggerDelay_ = delay;
-    impl.initialDelay_ = delay + static_cast<int>(regionDelay(region, midiState) * impl.sampleRate_);
     impl.baseFrequency_ = tuning.getFrequencyOfKey(impl.triggerEvent_.number);
     impl.sampleEnd_ = int(sampleEnd(region, midiState));
     impl.sampleSize_ = impl.sampleEnd_- impl.sourcePosition_ - 1;
@@ -2079,6 +2082,12 @@ int Voice::getSourcePosition() const noexcept
     return impl.sourcePosition_;
 }
 
+unsigned Voice::getStartTimestampSamples() const noexcept
+{
+    Impl& impl = *impl_;
+    return impl.startTimestamp_;
+}
+
 LFO* Voice::getLFO(size_t index)
 {
     Impl& impl = *impl_;

src/sfizz/Voice.h

@@ -437,6 +437,13 @@ public:
      */
     int getSourcePosition() const noexcept;
 
+    /**
+     * @brief Get the timestamp in midistate transport sample time when the voice was started, in samples
+     *
+     * @return int
+     */
+    unsigned getStartTimestampSamples() const noexcept;
+
 public:
     /**
      * @brief Check if the voice already belongs to a sister ring

src/sfizz/VoiceManager.cpp

@@ -244,6 +244,16 @@ void VoiceManager::checkNotePolyphony(const Region* region, int delay, const Tri
     }
 }
 
+bool VoiceManager::withinValidTimerRange(const Region* region, unsigned timestampSamples, float sampleRate) const noexcept
+{
+    auto found = polyphonyGroups_.find(static_cast<int>(region->group));
+    if (found != polyphonyGroups_.end()) {
+        // convert timestamp to seconds
+        return region->timerRange.contains((timestampSamples - found->second.getMostRecentStartTimestamp()) / sampleRate);
+    }
+    return true;
+}
+
 void VoiceManager::checkGroupPolyphony(const Region* region, int delay) noexcept
 {
     auto& group = polyphonyGroups_[region->group];

src/sfizz/VoiceManager.h

@@ -139,6 +139,16 @@ struct VoiceManager final : public Voice::StateListener
      */
     void requireNumVoices(int numVoices, Resources& resources);
 
+    /**
+     * @brief Is this timestamp within the lo/hitimer range for this region based on current group activity
+     *
+     * @param region
+     * @param timestampSamples in samples
+     * @param sampleRate
+     * @return bool
+     */
+    bool withinValidTimerRange(const Region* region, unsigned timestampSamples, float sampleRate) const noexcept;
+
 private:
     int numRequiredVoices_ { config::numVoices };
     std::vector<Voice> list_;