Version 3.2

src/OnePole.cpp

@@ -0,0 +1,101 @@
+/*******************************************/
+/*
+   One Pole Filter Class,
+   by Perry R. Cook, 1995-96.
+   Added methods by Julius Smith, 2000.
+
+   The parameter gain is an additional
+   gain parameter applied to the filter
+   on top of the normalization that takes
+   place automatically.  So the net max
+   gain through the system equals the
+   value of gain.  sgain is the combina-
+   tion of gain and the normalization
+   parameter, so if you set the poleCoeff
+   to alpha, sgain is always set to
+   gain * (1.0 - fabs(alpha)).
+*/
+/*******************************************/
+
+#include "OnePole.h"
+
+OnePole :: OnePole() : Filter()
+{
+  poleCoeff = (MY_FLOAT) 0.9;
+  gain = (MY_FLOAT) 1.0;
+  sgain = (MY_FLOAT) 0.1;
+  outputs = (MY_FLOAT *) malloc(sizeof(MY_FLOAT));
+  outputs[0] = (MY_FLOAT) 0.0;
+  lastOutput = (MY_FLOAT) 0.0;
+}
+
+OnePole :: OnePole(MY_FLOAT thePole) : Filter()
+{
+  poleCoeff = thePole;
+  gain = (MY_FLOAT) 1.0;
+  sgain = (MY_FLOAT) 1.0 - fabs(thePole);
+  outputs = (MY_FLOAT *) malloc(sizeof(MY_FLOAT));
+  outputs[0] = (MY_FLOAT) 0.0;
+  lastOutput = (MY_FLOAT) 0.0;
+}
+
+OnePole :: ~OnePole()    
+{
+  free(outputs);
+}
+
+void OnePole :: clear()
+{
+  outputs[0] = (MY_FLOAT) 0.0;
+  lastOutput = (MY_FLOAT) 0.0;
+}
+
+void OnePole :: setB0(MY_FLOAT aValue)
+{
+  sgain = aValue;
+}
+
+void OnePole :: setNum(MY_FLOAT *values)
+{
+  sgain = values[0];
+}
+
+void OnePole :: setA1(MY_FLOAT aValue)
+{
+  poleCoeff = -aValue;
+}
+
+void OnePole :: setDen(MY_FLOAT *values)
+{
+  poleCoeff = -values[0];
+}
+
+void OnePole :: setPole(MY_FLOAT aValue)
+{
+  poleCoeff = aValue;
+  // Normalize gain to 1.0 max
+  if (poleCoeff > (MY_FLOAT) 0.0)
+    sgain = gain * ((MY_FLOAT) 1.0 - poleCoeff);
+  else
+    sgain = gain * ((MY_FLOAT) 1.0 + poleCoeff);
+}
+
+void OnePole :: setGain(MY_FLOAT aValue)
+{
+  gain = aValue;
+
+  // Normalize gain to 1.0 max
+  if (poleCoeff > (MY_FLOAT) 0.0)
+    sgain = gain * ((MY_FLOAT) 1.0 - poleCoeff);
+  else
+    sgain = gain * ((MY_FLOAT) 1.0 + poleCoeff);
+}
+
+// Perform Filter Operation
+MY_FLOAT OnePole :: tick(MY_FLOAT sample)
+{
+  outputs[0] = (sgain * sample) + (poleCoeff * outputs[0]);              
+  lastOutput = outputs[0];
+  return lastOutput;
+}
+