Version 4.0

include/DelayA.h

@@ -0,0 +1,65 @@
+/***************************************************/
+/*! \class DelayA
+    \brief STK allpass interpolating delay line class.
+
+    This Delay subclass implements a fractional-
+    length digital delay-line using a first-order
+    allpass filter.  A fixed maximum length
+    of 4095 and a delay of 0.5 is set using the
+    default constructor.  Alternatively, the
+    delay and maximum length can be set during
+    instantiation with an overloaded constructor.
+
+    An allpass filter has unity magnitude gain but
+    variable phase delay properties, making it useful
+    in achieving fractional delays without affecting
+    a signal's frequency magnitude response.  In
+    order to achieve a maximally flat phase delay
+    response, the minimum delay possible in this
+    implementation is limited to a value of 0.5.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
+*/
+/***************************************************/
+
+#if !defined(__DelayA_h)
+#define __DelayA_h
+
+#include "Delay.h"
+
+class DelayA : public Delay
+{
+public:
+
+  //! Default constructor creates a delay-line with maximum length of 4095 samples and zero delay.
+  DelayA();
+
+  //! Overloaded constructor which specifies the current and maximum delay-line lengths.
+  
+  DelayA(MY_FLOAT theDelay, long maxDelay);
+
+  //! Class destructor.
+  ~DelayA();
+
+  //! Clears the internal state of the delay line.
+  void clear();
+
+  //! Set the delay-line length
+  /*!
+    The valid range for \e theDelay is from 0.5 to the maximum delay-line length.
+  */
+  void setDelay(MY_FLOAT theDelay);
+
+  //! Return the current delay-line length.
+  MY_FLOAT getDelay(void);
+
+  //! Input one sample to the delay-line and return one output.
+  MY_FLOAT tick(MY_FLOAT sample);
+
+protected:  
+    MY_FLOAT alpha;
+    MY_FLOAT coeff;
+    MY_FLOAT apInput;
+};
+
+#endif