Version 4.0

2026-01-11 20:11:52 +00:00 · 2013-09-25 14:50:19 +02:00
parent 3f126af4e5
commit 81475b04c5
473 changed files with 36355 additions and 28396 deletions
--- a/include/BiQuad.h
+++ b/include/BiQuad.h
@@ -1,40 +1,100 @@
-/*******************************************/
-/*
-   BiQuad (2-pole, 2-zero) Filter Class,
-   by Perry R. Cook, 1995-96.
-   Modified by Julius Smith, 2000:
-     setA1,setA2,setB1,setB2
-
-   See books on filters to understand
-   more about how this works.  Nothing
-   out of the ordinary in this version.
-*/
-/*******************************************/
-
-#if !defined(__BiQuad_h)
-#define __BiQuad_h
-
-#include "Filter.h"
-
-class BiQuad : public Filter
-{
-protected:  
-  MY_FLOAT poleCoeffs[2];
-  MY_FLOAT zeroCoeffs[2];
-public:
-  BiQuad();
-  ~BiQuad();
-  void clear();
-  void setA1(MY_FLOAT a1);
-  void setA2(MY_FLOAT a2);
-  void setB1(MY_FLOAT b1);
-  void setB2(MY_FLOAT b2);
-  void setPoleCoeffs(MY_FLOAT *coeffs);
-  void setZeroCoeffs(MY_FLOAT *coeffs);
-  void setGain(MY_FLOAT aValue);
-  void setFreqAndReson(MY_FLOAT freq, MY_FLOAT reson);
-  void setEqualGainZeroes();
-  MY_FLOAT tick(MY_FLOAT sample);
-};
-
-#endif
+/***************************************************/
+/*! \class BiQuad
+    \brief STK biquad (two-pole, two-zero) filter class.
+
+    This protected Filter subclass implements a
+    two-pole, two-zero digital filter.  A method
+    is provided for creating a resonance in the
+    frequency response while maintaining a constant
+    filter gain.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
+*/
+/***************************************************/
+
+#if !defined(__BIQUAD_H)
+#define __BIQUAD_H
+
+#include "Filter.h"
+
+class BiQuad : protected Filter
+{
+public:
+
+  //! Default constructor creates a second-order pass-through filter.
+  BiQuad();
+
+  //! Class destructor.
+  virtual ~BiQuad();
+
+  //! Clears all 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 b[2] coefficient value.
+  void setB2(MY_FLOAT b2);
+
+  //! Set the a[1] coefficient value.
+  void setA1(MY_FLOAT a1);
+
+  //! Set the a[2] coefficient value.
+  void setA2(MY_FLOAT a2);
+
+  //! Sets the filter coefficients for a resonance at \e frequency (in Hz).
+  /*!
+    This method determines the filter coefficients corresponding to
+    two complex-conjugate poles with the given \e frequency (in Hz)
+    and \e radius from the z-plane origin.  If \e normalize is true,
+    the filter zeros are placed at z = 1, z = -1, and the coefficients
+    are then normalized to produce a constant unity peak gain
+    (independent of the filter \e gain parameter).  The resulting
+    filter frequency response has a resonance at the given \e
+    frequency.  The closer the poles are to the unit-circle (\e radius
+    close to one), the narrower the resulting resonance width.
+  */
+  void setResonance(MY_FLOAT frequency, MY_FLOAT radius, bool normalize = FALSE);
+
+  //! Set the filter coefficients for a notch at \e frequency (in Hz).
+  /*!
+    This method determines the filter coefficients corresponding to
+    two complex-conjugate zeros with the given \e frequency (in Hz)
+    and \e radius from the z-plane origin.  No filter normalization
+    is attempted.
+  */
+  void setNotch(MY_FLOAT frequency, MY_FLOAT radius);
+
+  //! Sets the filter zeroes for equal resonance gain.
+  /*!
+    When using the filter as a resonator, zeroes places at z = 1, z
+    = -1 will result in a constant gain at resonance of 1 / (1 - R),
+    where R is the pole radius setting.
+
+  */
+  void setEqualGainZeroes();
+
+  //! 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