only do smoothing if we need to, and keep db conversion out of the sampe loop

src/nam_plugin.cpp

@@ -6,6 +6,8 @@
 #include "activations.h"
 #include <cassert>
 
+#define SMOOTH_EPSILON .0001f
+
 namespace NAM {
 	Plugin::Plugin()
 	{
@@ -186,13 +188,28 @@ namespace NAM {
 		if (dblData.size() != n_samples)
 			dblData.resize(n_samples);
 
+		// convert input level from db
+		float desiredInputLevel = powf(10, *(ports.input_level) * 0.05f);
+
+		if (fabs(desiredInputLevel - inputLevel) > SMOOTH_EPSILON)
+		{
 			for (unsigned int i = 0; i < n_samples; i++)
 			{
-			// Convert input level from db and do very basic smoothing
+				// do very basic smoothing
-			inputLevel = (.99f * inputLevel) + (.01f * powf(10, *(ports.input_level) * 0.05f));
+				inputLevel = (.99f * inputLevel) + (.01f * desiredInputLevel);
 
 				dblData[i] = ports.audio_in[i] * inputLevel;
 			}
+		}
+		else
+		{
+			inputLevel = desiredInputLevel;
+
+			for (unsigned int i = 0; i < n_samples; i++)
+			{
+				dblData[i] = ports.audio_in[i] * inputLevel;
+			}
+		}
 
 		if (currentModel == nullptr)
 		{
@@ -205,13 +222,28 @@ namespace NAM {
 			currentModel->finalize_(n_samples);
 		}
 
+		// convert output level from db
+		float desiredOutputLevel = powf(10, *(ports.output_level) * 0.05f);
+
+		if (fabs(desiredOutputLevel - outputLevel) > SMOOTH_EPSILON)
+		{
 			for (unsigned int i = 0; i < n_samples; i++)
 			{
-			// Convert output level from db and do very basic smoothing
+				// do very basic smoothing
-			outputLevel = (.99f * outputLevel) + (.01f * powf(10, *(ports.output_level) * 0.05f));
+				outputLevel = (.99f * outputLevel) + (.01f * desiredOutputLevel);
 
 				ports.audio_out[i] = (float)(dblData[i] * outputLevel);
 			}
+		}
+		else
+		{
+			outputLevel = desiredOutputLevel;
+
+			for (unsigned int i = 0; i < n_samples; i++)
+			{
+				ports.audio_out[i] = (float)(dblData[i] * outputLevel);
+			}
+		}
 
 		if (stateChanged)
 		{