BogaudioModules

commit 2493251e26b5c68c036d56f345500fbd0181fb83
parent 1cdca5630f0daa24e63ba80edd733c6545021e0b
Author: Matt Demanett <matt@demanett.net>
Date:   Mon, 17 Feb 2020 12:25:09 -0500

DC blocker dsp.

Diffstat:
M
src/Test.cpp
 | 
6
++++++
M
src/Test.hpp
 | 
7
++++++-
M
src/dsp/filter.cpp
 | 
8
++++++++
M
src/dsp/filter.hpp
 | 
7
+++++++

4 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/src/Test.cpp b/src/Test.cpp
@@ -445,6 +445,12 @@ void Test::processChannel(const ProcessArgs& args, int _c) {
 	_walk2.setParams(APP->engine->getSampleRate(), change);
 	outputs[OUT_OUTPUT].setVoltage(_walk1.next());
 	outputs[OUT2_OUTPUT].setVoltage(_walk2.next());
+
+#elif DCBLOCKER
+	float in = inputs[IN_INPUT].getVoltage();
+	outputs[OUT_OUTPUT].setVoltage(_filter.next(in));
+	outputs[OUT2_OUTPUT].setVoltage(in);
+
 #endif
 }
 
diff --git a/src/Test.hpp b/src/Test.hpp
@@ -28,7 +28,8 @@ extern Model* modelTest;
 // #define RAVG 1
 // #define SATURATOR 1
 // #define BROWNIAN 1
-#define RANDOMWALK 1
+// #define RANDOMWALK 1
+#define DCBLOCKER 1
 
 #include "pitch.hpp"
 #ifdef LPF
@@ -92,6 +93,8 @@ extern Model* modelTest;
 #include "dsp/noise.hpp"
 #elif RANDOMWALK
 #include "dsp/noise.hpp"
+#elif DCBLOCKER
+#include "dsp/filter.hpp"
 #else
 #error what
 #endif
@@ -227,6 +230,8 @@ struct Test : BGModule {
 #elif RANDOMWALK
 	RandomWalk _walk1;
 	RandomWalk _walk2;
+#elif DCBLOCKER
+	DCBlocker _filter;
 #endif
 
 	Test()
diff --git a/src/dsp/filter.cpp b/src/dsp/filter.cpp
@@ -71,6 +71,14 @@ void LowPassFilter::setParams(float sampleRate, float cutoff, float q) {
 }
 
 
+float DCBlocker::next(float sample) {
+	const float r = 0.999f;
+	_lastOut = sample - _lastIn + r * _lastOut;
+	_lastIn = sample;
+	return _lastOut;
+}
+
+
 // Adapted from Smith 1997, "The Scientist and Engineer's Guide to DSP"
 void MultipoleFilter::setParams(
 	Type type,
diff --git a/src/dsp/filter.hpp b/src/dsp/filter.hpp
@@ -98,6 +98,13 @@ struct LowPassFilter : Filter {
 	}
 };
 
+struct DCBlocker : Filter {
+	float _lastIn = 0.0f;
+	float _lastOut = 0.0f;
+
+	float next(float sample) override;
+};
+
 struct MultipoleFilter : Filter {
 	enum Type {
 		LP_TYPE,