From 062d1e074c2e98c107bdf24aaaf2f02c87bcea10 Mon Sep 17 00:00:00 2001
From: Liam Kerr <liam.d.kerr@protonmail.com>
Date: Wed, 12 Aug 2026 01:27:00 +0100
Subject: [PATCH] feat: improve oscillator initialization values and LFO sync
 implementation with bar tracking

---
 core/Oscillator.cpp                       | 22 +++++++++-----
 plugins/SquidgeFilter/DistrhoPluginInfo.h |  1 +
 plugins/SquidgeFilter/SquidgeFilter.cpp   | 37 ++++++++++-------------
 3 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/core/Oscillator.cpp b/core/Oscillator.cpp
index 7cee116..0f4b8a6 100644
--- a/core/Oscillator.cpp
+++ b/core/Oscillator.cpp
@@ -4,13 +4,17 @@
 
 Oscillator::Oscillator(float initFreq)
     : freq_(initFreq), gain_(100.0f), waveShape_(kWaveShapeSine),
-      sampleRate_(48000.f), phase_(0.0f), inc_(0.0f) {
+      sampleRate_(48000.f), phase_(0.0f), inc_(0.0f)
+{
   recalc_();
 };
 
-void Oscillator::process(float *out, uint32_t frames) {
-  for (uint32_t i = 0; i < frames; ++i) {
-    switch (waveShape_) {
+void Oscillator::process(float *out, uint32_t frames)
+{
+  for (uint32_t i = 0; i < frames; ++i)
+  {
+    switch (waveShape_)
+    {
     default:
     case kWaveShapeSine:
       out[i] = std::sinf(phase_ * 2.0f * M_PI) * gain_;
@@ -26,17 +30,21 @@ void Oscillator::reset() { phase_ = 0; }
 
 void Oscillator::recalc_() { inc_ = freq_ / sampleRate_; }
 
-void Oscillator::setFrequency(float newFreq) {
+void Oscillator::setFrequency(float newFreq)
+{
   freq_ = std::fmax(newFreq, 0.0f);
+  recalc_();
 }
 float Oscillator::getFrequency() const { return freq_; };
 
-void Oscillator::setGain(float newGain) {
+void Oscillator::setGain(float newGain)
+{
   gain_ = newGain > 0 ? newGain : 1.0f;
 }
 float Oscillator::getGain() const { return gain_; };
 
-void Oscillator::setSampleRate(float newSampleRate) {
+void Oscillator::setSampleRate(float newSampleRate)
+{
   sampleRate_ = newSampleRate > 0 ? newSampleRate : 48000.0f;
   recalc_();
 }
diff --git a/plugins/SquidgeFilter/DistrhoPluginInfo.h b/plugins/SquidgeFilter/DistrhoPluginInfo.h
index 1e69a67..c9adf22 100644
--- a/plugins/SquidgeFilter/DistrhoPluginInfo.h
+++ b/plugins/SquidgeFilter/DistrhoPluginInfo.h
@@ -15,6 +15,7 @@
 
 #define DISTRHO_PLUGIN_WANT_PROGRAMS 0
 #define DISTRHO_PLUGIN_WANT_STATE 0
+#define DISTRHO_PLUGIN_WANT_TIMEPOS 1
 
 #define DISTRHO_PLUGIN_HAS_UI 0
 #define DISTRHO_PLUGIN_IS_SYNTH 0
diff --git a/plugins/SquidgeFilter/SquidgeFilter.cpp b/plugins/SquidgeFilter/SquidgeFilter.cpp
index 9397f8f..028f04e 100644
--- a/plugins/SquidgeFilter/SquidgeFilter.cpp
+++ b/plugins/SquidgeFilter/SquidgeFilter.cpp
@@ -22,8 +22,8 @@ public:
   };
 
   SquidgeFilter()
-      : Plugin(kParameterCount, 0, 0), filter_(1000.0f, 0.707f, 48000.0f),
-        lfo_(4.0f) {
+      : Plugin(kParameterCount, 0, 0), filter_(440.0f, 2.0f, 48000.0f),
+        lfo_(20.0f), lfoSync_(0.0f) {
     filter_.setType(Filter::kLowPass);
   }
 
@@ -43,16 +43,16 @@ protected:
       parameter.name = "Frequency";
       parameter.symbol = "frequency";
       parameter.ranges.min = 20.0f;
-      parameter.ranges.def = 1000.0f;
-      parameter.ranges.max = 20000.0f;
+      parameter.ranges.def = 440.0f;
+      parameter.ranges.max = 10000.0f;
       parameter.hints = kParameterIsAutomatable | kParameterIsLogarithmic;
       break;
 
     case kParamResonance:
       parameter.name = "Resonance";
       parameter.symbol = "resonance";
-      parameter.ranges.min = 0.1f;
-      parameter.ranges.def = 0.707f;
+      parameter.ranges.min = 0.9f;
+      parameter.ranges.def = 2.0f;
       parameter.ranges.max = 20.0f;
       parameter.hints = kParameterIsAutomatable;
       break;
@@ -149,31 +149,25 @@ protected:
     const TimePosition &timePos = getTimePosition();
 
     float targetFreq = 4.0f;
-    int syncIndex = static_cast<int>(lfoSync_);
-
-    if (syncIndex < 0)
-      syncIndex = 0;
-    if (syncIndex > 6)
-      syncIndex = 6;
 
     if (timePos.bbt.valid && timePos.playing &&
         timePos.bbt.beatsPerMinute > 0.0) {
+      float bpb = static_cast<float>(timePos.bbt.beatsPerBar);
       float bpm = static_cast<float>(timePos.bbt.beatsPerMinute);
+      float bar = static_cast<float>(timePos.bbt.bar);
 
-      float baseFreq = (bpm / 60.0f) * 4.0f;
+      if (bar != currentBar_) {
+        lfo_.reset();
+        currentBar_ = bar;
+      }
+
+      float baseFreq = (bpm / 60.0f) / bpb;
 
       static const float multipliers[] = {1.0f,  2.0f,  4.0f, 8.0f,
                                           16.0f, 32.0f, 64.0f};
 
-      targetFreq = baseFreq * multipliers[syncIndex];
-
-      static int lastBar = -1;
-      if (timePos.bbt.bar != lastBar) {
-        lfo_.reset();
-        lastBar = timePos.bbt.bar;
-      }
+      targetFreq = baseFreq * multipliers[static_cast<int>(lfoSync_)];
     } else {
-
       targetFreq = 1.0f;
     }
 
@@ -193,6 +187,7 @@ private:
   Filter filter_;
   Oscillator lfo_;
   float lfoSync_;
+  uint32_t currentBar_ = 0;
   float lfoBuffer_[BUFFER_SIZE];
 
   DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(SquidgeFilter);