Version 3.0

STK/OnePole.cpp

@@ -0,0 +1,62 @@
+/*******************************************/
+/*  One Pole Filter Class,                 */
+/*  by Perry R. Cook, 1995-96              */ 
+/*  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;
+}
+
+OnePole :: ~OnePole()    
+{
+  free(outputs);
+}
+
+void OnePole :: clear()
+{
+  outputs[0] = (MY_FLOAT) 0.0;
+  lastOutput = (MY_FLOAT) 0.0;
+}
+
+void OnePole :: setPole(MY_FLOAT aValue)
+{
+  poleCoeff = aValue;
+  if (poleCoeff > 0.0)                   // Normalize gain to 1.0 max
+    sgain = gain * ((MY_FLOAT) 1.0 - poleCoeff);
+  else
+    sgain = gain * ((MY_FLOAT) 1.0 + poleCoeff);
+}
+
+void OnePole :: setGain(MY_FLOAT aValue)
+{
+  gain = aValue;
+  if (poleCoeff > 0.0)        
+    sgain = gain * ((MY_FLOAT) 1.0 - poleCoeff);  // Normalize gain to 1.0 max
+  else
+    sgain = gain * ((MY_FLOAT) 1.0 + poleCoeff);
+}
+
+MY_FLOAT OnePole :: tick(MY_FLOAT sample)  // Perform Filter Operation
+{
+  outputs[0] = (sgain * sample) + (poleCoeff * outputs[0]);              
+  lastOutput = outputs[0];
+  return lastOutput;
+}
+