BogaudioModules

commit f30262be19977920bc06c8e74683253871df11fd
parent 48eea20e0215f2938d61415444023d83fbbc6bbe
Author: Matt Demanett <matt@demanett.net>
Date:   Sun, 19 Feb 2023 18:48:28 -0500

Fix slew limiter DSP to accomodate high sample rates and extreme shapes. #221 #220

Diffstat:
M
src/dsp/signal.cpp
 | 
18
+++++++++---------
M
src/dsp/signal.hpp
 | 
2
+-

2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/src/dsp/signal.cpp b/src/dsp/signal.cpp
@@ -183,25 +183,25 @@ void ShapedSlewLimiter::setParams(float sampleRate, float milliseconds, float sh
 }
 
 float ShapedSlewLimiter::next(float sample) {
-	float difference = sample - _last;
-	float ttg = fabsf(difference) / range;
-	if (_time < 0.0001f || ttg < 0.0001f) {
+	double difference = sample - _last;
+	double ttg = fabs(difference) / range;
+	if (_time < 0.0001f) {
 		return _last = sample;
 	}
 	if (_shapeExponent != 0.0f) {
-		ttg = powf(ttg, _shapeExponent);
+		ttg = pow(ttg, _shapeExponent);
 	}
 	ttg *= _time;
-	ttg = std::max(0.0f, ttg - _sampleTime);
+	ttg = std::max(0.0, ttg - _sampleTime);
 	ttg /= _time;
 	if (_shapeExponent != 0.0f) {
-		ttg = powf(ttg, _inverseShapeExponent);
+		ttg = pow(ttg, _inverseShapeExponent);
 	}
-	float y = fabsf(difference) - ttg * range;
+	double y = fabs(difference) - ttg * range;
 	if (difference < 0.0f) {
-		return _last = std::max(_last - y, sample);
+		return _last = std::max(_last - y, (double)sample);
 	}
-	return _last = std::min(_last + y, sample);
+	return _last = std::min(_last + y, (double)sample);
 }
 
 
diff --git a/src/dsp/signal.hpp b/src/dsp/signal.hpp
@@ -121,7 +121,7 @@ struct ShapedSlewLimiter {
 	float _time;
 	float _shapeExponent;
 	float _inverseShapeExponent;
-	float _last = 0.0;
+	double _last = 0.0;
 
 	ShapedSlewLimiter(float sampleRate = 1000.0f, float milliseconds = 1.0f, float shape = 1.0f) {
 		setParams(sampleRate, milliseconds, shape);