modules/audio_filter/spatializer/comb.hpp

   1 // Comb filter class declaration
   2 //
   3 // Written by Jezar at Dreampoint, June 2000
   4 // http://www.dreampoint.co.uk
   5 // This code is public domain
   6
   7 #ifndef _comb_
   8 #define _comb_
   9
  10 #include "denormals.h"
  11
  12 class comb
  13 {
  14 public:
  15     comb();
  16     void    setbuffer(float *buf, int size);
  17     inline  float    process(float inp);
  18     void    mute();
  19     void    setdamp(float val);
  20     float    getdamp();
  21     void    setfeedback(float val);
  22     float    getfeedback();
  23 private:
  24     float    feedback;
  25     float    filterstore;
  26     float    damp1;
  27     float    damp2;
  28     float    *buffer;
  29     int    bufsize;
  30     int    bufidx;
  31 };
  32
  33
  34 // Big to inline - but crucial for speed
  35
  36 inline float comb::process(float input)
  37 {
  38
  39 #if 1
  40     /* FIXME FIXME FIXME
  41      * comb::process is completly broken so ignore it for now */
  42     return 0.0;
  43
  44 #else
  45     float output;
  46
  47     output = undenormalise( buffer[bufidx] );
  48
  49     filterstore = undenormalise( output*damp2 + filterstore*damp1 );
  50
  51     buffer[bufidx] = input + filterstore*feedback;
  52
  53     if(++bufidx>=bufsize) bufidx = 0;
  54
  55     return output;
  56 #endif
  57 }
  58
  59 #endif //_comb_
  60
  61 //ends