text: /* Copyright (c) 2003 krzYszcz and others.
   * For information on usage and redistribution, and for a DISCLAIMER OF ALL
   * WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */
  
  #include "m_pd.h"
  #include <common/api.h>
  
  #define ZEROX_DEFVOLUME  1.
  
  typedef struct _zerox
  {
      t_object x_obj;
      t_inlet  *x_inlet;
      t_float  x_volume;
      int      x_lastsign;
  } t_zerox;
  
  static t_class *zerox_class;
  
  static void zerox_set(t_zerox *x, t_floatarg f)
  {
      x->x_volume = f;  /* CHECKED anything goes (including 0.) */
  }
  
  static t_int *zerox_perform(t_int *w)
  {
      t_zerox *x = (t_zerox *)(w[1]);
      int nblock = (int)(w[2]);
      t_float *in = (t_float *)(w[3]);
      t_float *out1 = (t_float *)(w[4]);
      t_float *out2 = (t_float *)(w[5]);
      t_float volume = x->x_volume;
      int lastsign = x->x_lastsign;
      int i = nblock;
      int count = 0;
      t_float fcount;
      while (i--)
      {
  	/* CHECKED -1 -> 0 and 0 -> -1 are hits, 1 -> 0, 0 -> 1 are not */
  	int sign = (*in++ < 0 ? 1. : 0.);  /* LATER read the sign bit */
  	if (sign != lastsign)
  	{
  	    count++;
  	    *out2++ = volume;
  	    lastsign = sign;
  	}
  	else *out2++ = 0.;
      }
      fcount = (t_float)count;
      while (nblock--) *out1++ = fcount;
      x->x_lastsign = lastsign;
      return (w + 6);
  }
  
  static void zerox_dsp(t_zerox *x, t_signal **sp)
  {
      dsp_add(zerox_perform, 5, x, sp[0]->s_n,
  	    sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec);
  }
  
  static void *zerox_new(t_floatarg f)
  {
      t_zerox *x = (t_zerox *)pd_new(zerox_class);
      x->x_volume = (f == 0. ? ZEROX_DEFVOLUME : f);
      x->x_lastsign = 0;  /* CHECKED the very first sample hits if negative */
      outlet_new((t_object *)x, &s_signal);
      outlet_new((t_object *)x, &s_signal);
      return (x);
  }
  
  CYCLONE_OBJ_API void zerox_tilde_setup(void)
  {
      zerox_class = class_new(gensym("zerox~"),
  			    (t_newmethod)zerox_new, 0,
  			    sizeof(t_zerox), 0, A_DEFFLOAT, 0);
      class_addmethod(zerox_class, nullfn, gensym("signal"), 0);
      class_addmethod(zerox_class, (t_method)zerox_dsp, gensym("dsp"), A_CANT, 0);
      class_addmethod(zerox_class, (t_method)zerox_set,
  		    gensym("set"), A_FLOAT, 0);  /* CHECKED arg obligatory */
  }
  