Version 4.0

include/PoleZero.h

@@ -1,32 +1,79 @@
-/*******************************************/
-/*  PoleZero (1-pole, 1-zero) Filter Class */
-/*  by Gary P. Scavone, 1999               */
-/*                                         */
-/*  See books on filters to understand     */
-/*  more about how this works.  Nothing    */
-/*  out of the ordinary in this version.   */
-/*******************************************/
-
-#if !defined(__PoleZero_h)
-#define __PoleZero_h
-
-#include "Filter.h"
-
-class PoleZero : public Filter
-{
- protected:  
-  MY_FLOAT a1Coeff;
-  MY_FLOAT b0Coeff;
-  MY_FLOAT b1Coeff;
- public:
-  PoleZero();
-  ~PoleZero();
-  void clear();
-  void setA1(MY_FLOAT coeff);
-  void setB0(MY_FLOAT coeff);
-  void setB1(MY_FLOAT coeff);
-  void setGain(MY_FLOAT aValue);
-  MY_FLOAT tick(MY_FLOAT sample);
-};
-
-#endif
+/***************************************************/
+/*! \class PoleZero
+    \brief STK one-pole, one-zero filter class.
+
+    This protected Filter subclass implements
+    a one-pole, one-zero digital filter.  A
+    method is provided for creating an allpass
+    filter with a given coefficient.  Another
+    method is provided to create a DC blocking filter.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
+*/
+/***************************************************/
+
+#if !defined(__POLEZERO_H)
+#define __POLEZERO_H
+
+#include "Filter.h"
+
+class PoleZero : protected Filter
+{
+ public:
+
+  //! Default constructor creates a first-order pass-through filter.
+  PoleZero();
+
+  //! Class destructor.
+  ~PoleZero();
+
+  //! Clears the internal states of the filter.
+  void clear(void);
+
+  //! Set the b[0] coefficient value.
+  void setB0(MY_FLOAT b0);
+
+  //! Set the b[1] coefficient value.
+  void setB1(MY_FLOAT b1);
+
+  //! Set the a[1] coefficient value.
+  void setA1(MY_FLOAT a1);
+
+  //! Set the filter for allpass behavior using \e coefficient.
+  /*!
+    This method uses \e coefficient to create an allpass filter,
+    which has unity gain at all frequencies.  Note that the \e
+    coefficient magnitude must be less than one to maintain stability.
+  */
+  void setAllpass(MY_FLOAT coefficient);
+
+  //! Create a DC blocking filter with the given pole position in the z-plane.
+  /*!
+    This method sets the given pole position, together with a zero
+    at z=1, to create a DC blocking filter.  \e thePole should be
+    close to one to minimize low-frequency attenuation.
+
+  */
+  void setBlockZero(MY_FLOAT thePole = 0.99);
+
+  //! Set the filter gain.
+  /*!
+    The gain is applied at the filter input and does not affect the
+    coefficient values.  The default gain value is 1.0.
+   */
+  void setGain(MY_FLOAT theGain);
+
+  //! Return the current filter gain.
+  MY_FLOAT getGain(void) const;
+
+  //! Return the last computed output value.
+  MY_FLOAT lastOut(void) const;
+
+  //! Input one sample to the filter and return one output.
+  MY_FLOAT tick(MY_FLOAT sample);
+
+  //! Input \e vectorSize samples to the filter and return an equal number of outputs in \e vector.
+  MY_FLOAT *tick(MY_FLOAT *vector, unsigned int vectorSize);
+};
+
+#endif