Move library tree where it belongs

lib-src/libnyquist/nyquist/nyqstk/include/OnePole.h

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+/***************************************************/
+/*! \class OnePole
+    \brief STK one-pole filter class.
+
+    This protected Filter subclass implements
+    a one-pole digital filter.  A method is
+    provided for setting the pole position along
+    the real axis of the z-plane while maintaining
+    a constant peak filter gain.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
+*/
+/***************************************************/
+
+#ifndef STK_ONEPOLE_H
+#define STK_ONEPOLE_H
+
+#include "Filter.h"
+
+namespace Nyq
+{
+
+class OnePole : protected Filter
+{
+public:
+
+  //! Default constructor creates a first-order low-pass filter.
+  OnePole();
+
+  //! Overloaded constructor which sets the pole position during instantiation.
+  OnePole( StkFloat thePole );
+
+  //! Class destructor.
+  ~OnePole();
+
+  //! Clears the internal state of the filter.
+  void clear(void);
+
+  //! Set the b[0] coefficient value.
+  void setB0(StkFloat b0);
+
+  //! Set the a[1] coefficient value.
+  void setA1(StkFloat a1);
+
+  //! Set the pole position in the z-plane.
+  /*!
+    This method sets the pole position along the real-axis of the
+    z-plane and normalizes the coefficients for a maximum gain of one.
+    A positive pole value produces a low-pass filter, while a negative
+    pole value produces a high-pass filter.  This method does not
+    affect the filter \e gain value.
+  */
+  void setPole(StkFloat thePole);
+
+  //! 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(StkFloat gain);
+
+  //! Return the current filter gain.
+  StkFloat getGain(void) const;
+
+  //! Return the last computed output value.
+  StkFloat lastOut(void) const;
+
+  //! Input one sample to the filter and return one output.
+  StkFloat tick(StkFloat sample);
+
+  //! Take a channel of the StkFrames object as inputs to the filter and replace with corresponding outputs.
+  /*!
+    The \c channel argument should be zero or greater (the first
+    channel is specified by 0).  An StkError will be thrown if the \c
+    channel argument is equal to or greater than the number of
+    channels in the StkFrames object.
+  */
+  StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
+
+};
+
+} // namespace Nyq
+
+#endif