0.2.0-beta.1: Filter modulation

CHANGELOG.md

@@ -2,6 +2,29 @@
 
 All notable changes to this project will be documented in this file.
 
+## \[0.2.0-beta.1] - 2026-05-06
+
+### Added
+
+* Filter modulation for High and Low cuts with independent LFOs
+  * LFO rate control
+  * LFO Tempo sync linked to song position during playback
+  * LFO phase offset per filter
+  * LFO Shape selection
+  * Filter modulation depth control
+  * Phase invert switch for high cut lfo (on by default)
+* Square, Saw Up/Down and Sample&Hold LFO Shapes
+* Indicator lights for both LFOs to get visual idea of its current value
+
+### Changed
+
+* Refactored filters to StereoFilter primitive and FilterEngine class
+* Set maximum resonance for low and high cut filters to 1.5
+
+### Known limitations
+
+* Tempo synced LFOs might sync incorrectly to song playback positions in DAW on extreme settings (very high or very low BPMs)
+
 ## \[0.1.0] - 2026-04-17
 
 ### Added

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.22)
 
-project(viive VERSION 0.1.0)
+project(viive VERSION 0.2.0)
 
 
 ### Dependency versions ###
@@ -41,6 +41,7 @@ set(VST3_DEV_COPY_DIR "" CACHE PATH "If set, copies the Debug VST3 build here af
 ### Plugin Project Setup ###
 
 juce_add_plugin(viive
+    VERSION 0.2.0
     FORMATS VST3 Standalone
     PRODUCT_NAME "viive"
     COMPANY_NAME "trsctr"
@@ -67,9 +68,12 @@ get_property(project_targets DIRECTORY "${PROJECT_SOURCE_DIR}" PROPERTY BUILDSYS
 set_target_properties(${project_targets} PROPERTIES CXX_EXTENSIONS OFF)
 
 target_sources(viive PRIVATE
+    Source/FilterEngine.cpp
     Source/Tempo.cpp
+    Source/Selector.cpp
     Source/SyncButton.cpp
     Source/StereoDelay.cpp
+    Source/StereoFilter.cpp
     Source/ChorusEngine.cpp
     Source/LFO.cpp
     Source/Chorus.cpp
@@ -78,7 +82,8 @@ target_sources(viive PRIVATE
     Source/DelayEngine.cpp
     Source/Parameters.cpp
     Source/PluginProcessor.cpp
-    Source/PluginEditor.cpp)
+    Source/PluginEditor.cpp
+    Source/LFOScope.cpp)
 
 juce_generate_juce_header(viive)
 

README.md

@@ -12,6 +12,7 @@ Currently developed and tested on Windows (JUCE AudioPluginHost, Ableton Live Su
 - Mix and feedback controls with feedback stabilization (0-140%)
 - Stereo width control with mid/side processing
 - Sculpting low/high-cut filters with adjustable resonance on delayed signal / feedback loop
+- Filter modulation section with separate LFOs for high and low cut filters with tempo sync, adjustable rate, modulation depth, stereo phase offset and selectable shapes: Sine, Triangle, Square, Saw Up/Down, Sample & Hold
 - Dual-voice chorus effect in feedback loop with intensity, modulation rate, and modulation depth controls
 - Feedback loop protection: HPF, compressor, soft clipping
 
@@ -31,8 +32,11 @@ Download the zip for your platform, extract it, and copy `viive.vst3` to your VS
 
 Then rescan plugins in your DAW.
 
+NOTE: MacOS build is untested and unsigned. May be blocked by Gatekeeper on 
+newer macOS versions and cannot be guaranteed to work without 
+code signing and notarization.
+
 ## Potential future features
-- LFO/modulation for general parameters (such as filter cutoffs)
 - Additional effects in feedback loop (bitcrush, phaser)
 - Preset manager
 - Single/dual delay mode switch
@@ -57,6 +61,8 @@ cmake --build Build --config Release
 
 JUCE 8.0.11 is downloaded automatically during configuration.
 
+NOTE: Linux builds are reportedly possible but untested and undocumented.
+
 ### Output
 The VST3 will be produced under `Build/viive_artefacts/Release/VST3/`.
 

Source/DelayEngine.cpp

@@ -1,9 +1,9 @@
 #include "DelayEngine.h"
 #include "DSP.h"
+#include "Types.h"
+
 DelayEngine::DelayEngine()
 {
-	m_lowCutFilter.setType(juce::dsp::StateVariableTPTFilterType::highpass);
-	m_highCutFilter.setType(juce::dsp::StateVariableTPTFilterType::lowpass);
 	m_feedbackHighpass.setType(juce::dsp::StateVariableTPTFilterType::highpass);
 	m_feedbackCompressor.setAttack(.1f);
 	m_feedbackCompressor.setRelease(50.f);
@@ -19,8 +19,7 @@ void DelayEngine::prepareToPlay(double sampleRate, int samplesPerBlock) noexcept
 	spec.numChannels = 2;
 	m_sampleRate = static_cast<float>(sampleRate);
 	m_feedbackCompressor.prepare(spec);
-	m_lowCutFilter.prepare(spec);
-	m_highCutFilter.prepare(spec);
+	m_filterEngine.prepareToPlay(sampleRate, samplesPerBlock);
 	m_feedbackHighpass.prepare(spec);
 	m_chorusEngine.prepareToPlay(sampleRate, samplesPerBlock);
 	m_stereoDelay.prepareToPlay(sampleRate, samplesPerBlock);
@@ -31,19 +30,14 @@ void DelayEngine::prepareToPlay(double sampleRate, int samplesPerBlock) noexcept
 void DelayEngine::reset() noexcept
 {
 	m_stereoDelay.reset();
-	m_lowCutFilter.reset();
-	m_highCutFilter.reset();
 	m_chorusEngine.reset();
+	m_filterEngine.reset();
 	m_feedbackHighpass.reset();
 	m_feedbackHighpass.setCutoffFrequency(60.0f); // just to remove rumble from fb loop
 	m_feedbackHighpass.setResonance(Parameters::defaultFilterQ);
 	m_feedbackCompressor.reset();
 	m_feedbackL = 0.0f;
 	m_feedbackR = 0.0f;
-	m_lowCutFreq = -1.0f;
-	m_lowCutQ = -1.0f;
-	m_highCutFreq = -1.0f;
-	m_highCutQ = -1.0f;
 	m_baseDelayTimeMs = -1.0f;
 	m_mixLevel = 0.5f;
 	m_feedbackLevel = 0.0f;
@@ -58,31 +52,6 @@ void DelayEngine::setDelayMode(const int modeIndex)
 	}
 }
 
-void DelayEngine::setLowCut(const Parameters& params) {
-	setFilterFreq(params.lowCutFreq(), m_lowCutFreq, m_lowCutFilter);
-	setFilterQ(params.lowCutQ(), m_lowCutQ, m_lowCutFilter);
-}
-
-void DelayEngine::setHighCut(const Parameters& params) {
-	setFilterFreq(params.highCutFreq(), m_highCutFreq, m_highCutFilter);
-	setFilterQ(params.highCutQ(), m_highCutQ, m_highCutFilter);
-}
-
-void DelayEngine::setFilterFreq(const float freq, float& currentFreq, Filter& filter) {
-	if (!juce::approximatelyEqual(freq, currentFreq)) {
-		filter.setCutoffFrequency(freq);
-		currentFreq = freq;
-	}
-}
-
-void DelayEngine::setFilterQ(const float q, float& currentQ, Filter& filter) {
-	float newQ = std::min(q, Parameters::maxFilterQ);
-	if (!juce::approximatelyEqual(newQ, currentQ)) {
-		filter.setResonance(newQ);
-		currentQ = newQ;
-	}
-}
-
 void DelayEngine::setDelayTimes(const float targetL, const float targetR) {
 	float targetLeftMs = targetL - m_offsetMs;
 	float targetRightMs = targetR + m_offsetMs;
@@ -98,14 +67,18 @@ void DelayEngine::setDelayTimes(const float targetL, const float targetR) {
 
 void DelayEngine::update(const Parameters& params)
 {
-	setLowCut(params);
-	setHighCut(params);
 	setMixLevel(params.mix());
 	setGainLevel(params.gain());
 	setFeedbackLevel(params.feedback());
 	setWidthLevel(params.stereo());
 	setOffsetMs(params.offset());
 	setDelayTimes(params.delayTimeL(), params.delayTimeR());
+	m_filterEngine.update(params);
+}
+
+void DelayEngine::updateSyncedModulators(const double ppqPosition)
+{
+	m_filterEngine.updateLFOs(ppqPosition);
 }
 
 void DelayEngine::processSample(const float& inL, const float& inR, float& outL, float& outR, const Parameters& params)
@@ -114,7 +87,7 @@ void DelayEngine::processSample(const float& inL, const float& inR, float& outL,
 	float dryR = inR;
 
 	float mono = (dryL + dryR) * .5f;
-	float delayInL = 0.0f, delayInR = 0.0f, popL = 0.0f, popR = 0.0f, wetL = 0.0f, wetR = 0.0f;
+	float delayInL = 0.0f, delayInR = 0.0f, wetL = 0.0f, wetR = 0.0f;
 	switch (m_delayMode) {
 		case DelayMode::PingPongLR:
 			delayInL = mono + m_feedbackR;
@@ -137,17 +110,12 @@ void DelayEngine::processSample(const float& inL, const float& inR, float& outL,
 			delayInR = dryR;
 	}
 
-	m_stereoDelay.processSample(delayInL, popL, Channel::Left);
-	m_stereoDelay.processSample(delayInR, popR, Channel::Right);
+	m_stereoDelay.processSample(delayInL, wetL, Channel::Left);
+	m_stereoDelay.processSample(delayInR, wetR, Channel::Right);
 
-	m_chorusEngine.processSample(popL, popR, wetL, wetR, params);
-
-	// sculpting filters, first left and then right channel
-	wetL = m_lowCutFilter.processSample(0, wetL);
-	wetL = m_highCutFilter.processSample(0, wetL);
+	m_chorusEngine.processSample(wetL, wetR, wetL, wetR, params);
 
-	wetR = m_lowCutFilter.processSample(1, wetR);
-	wetR = m_highCutFilter.processSample(1, wetR);
+	m_filterEngine.processSample(wetL, wetR, wetL, wetR);
 
 	// this removes rumble generated by low cut filter on higher q values
 	wetL = m_feedbackHighpass.processSample(0, wetL); 

Source/DelayEngine.h

@@ -3,6 +3,10 @@
 #include "Parameters.h"
 #include "ChorusEngine.h"
 #include "StereoDelay.h"
+#include "FilterEngine.h"
+#if JUCE_DEBUG
+#include "LFOScopeBuffer.h"
+#endif
 
 using Filter = juce::dsp::StateVariableTPTFilter<float>;
 
@@ -19,24 +23,26 @@ class DelayEngine
 
 	void update(const Parameters& params);
 	void processSample(const float& inL, const float& inR, float& outL, float& outR, const Parameters& params);
-	void setLowCut(const Parameters& params);
-	void setHighCut(const Parameters& params);
-	void setFilterFreq(const float freq, float& currentFreq, Filter& filter);
-	void setFilterQ(const float q, float& currentQ, Filter& filter);
 	void setDelayTimes(const float delayInMsL, const float delayInMsR);
 	void setFeedbackLevel(const float value) { m_feedbackLevel = value; }
 	void setMixLevel(const float value) { m_mixLevel = value; }
 	void setGainLevel(const float value) { m_gainLevel = value; }
 	void setWidthLevel(const float value) { m_widthLevel = value; }
 	void setOffsetMs(const float value) { m_offsetMs = value * .5f; }
 	void setDelayMode(const int modeIndex);
+	void updateSyncedModulators(const double ppqPosition);
+
+	std::atomic<float>& getLowCutLfoValue()  { return m_filterEngine.getLowCutLfoValue(); }
+	std::atomic<float>& getHighCutLfoValue() { return m_filterEngine.getHighCutLfoValue(); }
+
+#if JUCE_DEBUG
+	LFOScopeBuffer& getLFOScopeBuffer() { return m_filterEngine.m_scopeBuffer; }
+#endif
 
 private:
-	//juce::dsp::DelayLine<float, juce::dsp::DelayLineInterpolationTypes::Linear> m_delayLine;
 	StereoDelay m_stereoDelay;
 	DelayMode m_delayMode = DelayMode::Stereo;
-	Filter m_lowCutFilter;
-	Filter m_highCutFilter;
+	FilterEngine m_filterEngine;
 	Filter m_feedbackHighpass;
 	juce::dsp::Compressor<float> m_feedbackCompressor;
 	ChorusEngine m_chorusEngine;
@@ -57,10 +63,6 @@ class DelayEngine
 	float m_gainLevel = 1.0f;
 	float m_widthLevel = 1.0f;
 	float m_offsetMs = 0.0f;
-	float m_lowCutFreq = -1.0f;
-	float m_lowCutQ = -1.0f;
-	float m_highCutFreq = -1.0f;
-	float m_highCutQ = -1.0f;
 
 	JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(DelayEngine)
 };