BogaudioModules

commit 3dce7a876ee0dc9a69fcb73913a7f59019f7183b
parent 0a8d3750a690c1715bfeeb0a01f16ddb55f7dc57
Author: Matt Demanett <matt@demanett.net>
Date:   Wed, 30 May 2018 23:46:07 -0400

LFO/8FO: fix pulse width knobs, such that half knob yields true 50% pulse; RunningAverage DSP and test harness for debugging.

Diffstat:
M
src/EightFO.cpp
 | 
3
++-
M
src/LFO.cpp
 | 
3
++-
M
src/Test.cpp
 | 
6
++++++
M
src/Test.hpp
 | 
10
+++++++++-
M
src/dsp/signal.cpp
 | 
23
+++++++++++++++++------
M
src/dsp/signal.hpp
 | 
18
++++++++++++++----

6 files changed, 50 insertions(+), 13 deletions(-)
diff --git a/src/EightFO.cpp b/src/EightFO.cpp
@@ -55,8 +55,9 @@ void EightFO::step() {
 			if (inputs[SAMPLE_PWM_INPUT].active) {
 				pw *= clamp(inputs[SAMPLE_PWM_INPUT].value / 5.0f, -1.0f, 1.0f);
 			}
-			pw = (pw + 1.0f) / 2.0f;
 			pw *= 1.0f - 2.0f * _square.minPulseWidth;
+			pw *= 0.5f;
+			pw += 0.5f;
 			_square.setPulseWidth(pw);
 			_sampleSteps = 1;
 		}
diff --git a/src/LFO.cpp b/src/LFO.cpp
@@ -50,8 +50,9 @@ void LFO::step() {
 		if (inputs[PW_INPUT].active) {
 			pw *= clamp(inputs[PW_INPUT].value / 5.0f, -1.0f, 1.0f);
 		}
-		pw = (pw + 1.0f) / 2.0f;
 		pw *= 1.0f - 2.0f * _square.minPulseWidth;
+		pw *= 0.5f;
+		pw += 0.5f;
 		_square.setPulseWidth(pw);
 
 		float sample = params[SAMPLE_PARAM].value;
diff --git a/src/Test.cpp b/src/Test.cpp
@@ -377,6 +377,12 @@ void Test::step() {
 	outputs[OUT_OUTPUT].value = _rms.next(inputs[IN_INPUT].value);
 	_pef.setSensitivity(sensitivity);
 	outputs[OUT2_OUTPUT].value = _pef.next(inputs[IN_INPUT].value);
+
+#elif RAVG
+	if (_reset.process(inputs[CV1_INPUT].value)) {
+		_average.reset();
+	}
+	outputs[OUT_OUTPUT].value = _average.next(inputs[IN_INPUT].value);
 #endif
 }
 
diff --git a/src/Test.hpp b/src/Test.hpp
@@ -22,8 +22,9 @@ extern Model* modelTest;
 // #define FEEDBACK_PM 1
 // #define EG 1
 // #define TABLES 1
-#define SLEW 1
+// #define SLEW 1
 // #define RMS 1
+#define RAVG 1
 
 #include "pitch.hpp"
 #ifdef LPF
@@ -75,6 +76,8 @@ extern Model* modelTest;
 #include "dsp/signal.hpp"
 #elif RMS
 #include "dsp/signal.hpp"
+#elif RAVG
+#include "dsp/signal.hpp"
 #else
 #error what
 #endif
@@ -190,6 +193,9 @@ struct Test : Module {
 #elif RMS
 	RootMeanSquare _rms;
 	PucketteEnvelopeFollower _pef;
+#elif RAVG
+	RunningAverage _average;
+	SchmittTrigger _reset;
 #endif
 
 	Test()
@@ -201,6 +207,8 @@ struct Test : Module {
 	, _cicDecimator(STAGES)
 #elif TABLES
   , _table(StaticBlepTable::table(), 44100.0, 1000.0)
+#elif RAVG
+	, _average(engineGetSampleRate(), 1.0f, 1000.0f)
 #endif
 	{
 		onReset();
diff --git a/src/dsp/signal.cpp b/src/dsp/signal.cpp
@@ -48,7 +48,7 @@ float Amplifier::next(float s) {
 }
 
 
-void RootMeanSquare::setSampleRate(float sampleRate) {
+void RunningAverage::setSampleRate(float sampleRate) {
 	assert(sampleRate > 0.0f);
 	if (_sampleRate != sampleRate) {
 		_sampleRate = sampleRate;
@@ -64,7 +64,7 @@ void RootMeanSquare::setSampleRate(float sampleRate) {
 	}
 }
 
-void RootMeanSquare::setSensitivity(float sensitivity) {
+void RunningAverage::setSensitivity(float sensitivity) {
 	assert(sensitivity >= 0.0f);
 	assert(sensitivity <= 1.0f);
 	if (_initialized) {
@@ -95,21 +95,32 @@ void RootMeanSquare::setSensitivity(float sensitivity) {
 		_sumN = std::max(_sensitivity * _bufferN, 1.0f);
 		_leadI = 0;
 		_trailI = _bufferN - _sumN;
-		_sum = 0.0f;
+		_sum = 0.0;
 	}
 }
 
-float RootMeanSquare::next(float sample) {
+void RunningAverage::reset() {
+	_sum = 0.0;
+	std::fill(_buffer, _buffer + _bufferN, 0.0);
+}
+
+float RunningAverage::next(float sample) {
 	_sum -= _buffer[_trailI];
 	++_trailI;
 	_trailI %= _bufferN;
-	_sum += _buffer[_leadI] = sample * sample;
+	_sum += _buffer[_leadI] = sample;
 	++_leadI;
 	_leadI %= _bufferN;
+	return (float)_sum / (float)_sumN;
+}
+
+
+float RootMeanSquare::next(float sample) {
+	float a = RunningAverage::next(sample * sample);
 	if (_sum <= 0.0) {
 		return 0.0f;
 	}
-	return sqrtf((float)_sum / (float)_sumN);
+	return sqrtf(a);
 }
 
 
diff --git a/src/dsp/signal.hpp b/src/dsp/signal.hpp
@@ -38,7 +38,7 @@ struct Amplifier {
 	float next(float s);
 };
 
-struct RootMeanSquare {
+struct RunningAverage {
 	float _maxDelayMS;
 	float _sampleRate = -1.0f;
 	float _sensitivity = -1.0f;
@@ -51,11 +51,11 @@ struct RootMeanSquare {
 	int _trailI = 0;
 	double _sum = 0;
 
-	RootMeanSquare(float sampleRate = 1000.0f, float sensitivity = 1.0f, float maxDelayMS = 300.0f) : _maxDelayMS(maxDelayMS) {
+	RunningAverage(float sampleRate = 1000.0f, float sensitivity = 1.0f, float maxDelayMS = 300.0f) : _maxDelayMS(maxDelayMS) {
 		setSampleRate(sampleRate);
 		setSensitivity(sensitivity);
 	}
-	~RootMeanSquare() {
+	virtual ~RunningAverage() {
 		if (_buffer) {
 			delete[] _buffer;
 		}
@@ -63,7 +63,17 @@ struct RootMeanSquare {
 
 	void setSampleRate(float sampleRate);
 	void setSensitivity(float sensitivity);
-	float next(float sample);
+	void reset();
+	virtual float next(float sample);
+};
+
+struct RootMeanSquare : RunningAverage {
+	RootMeanSquare(float sampleRate = 1000.0f, float sensitivity = 1.0f, float maxDelayMS = 300.0f)
+	: RunningAverage(sampleRate, sensitivity, maxDelayMS)
+	{
+	}
+
+	virtual float next(float sample) override;
 };
 
 // Puckette 2007, "Theory and Technique"