/* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution.

iem_spec2 written by Thomas Musil, Copyright (c) IEM KUG Graz Austria 2000 - 2006 */

#include "m_pd.h"
#include "iemlib.h"
#include <math.h>

/* ------------------------ spec2_sqrt_tilde~ ------------------------- */

static t_class *spec2_sqrt_tilde_class;

typedef struct _spec2_sqrt_tilde
{
  t_object  x_obj;
  t_float   x_msi;
} t_spec2_sqrt_tilde;

static t_int *spec2_sqrt_tilde_perform(t_int *w)
{
  t_float *in = (t_float *)(w[1]);
  t_float *out = (t_float *)(w[2]);
  int n = w[3]+1;
  
  while(n--)
  {
    t_sample f = *in++;

    if (f<0.0)
	{
      *out++=0.0;
    }
	else
	{
#if ((defined PD_MAJOR_VERSION && defined PD_MINOR_VERSION) && (PD_MAJOR_VERSION > 0 || PD_MINOR_VERSION > 43))
	  t_float g = q8_rsqrt(f);
            
      *out++ = f*g*(1.5 - 0.5 * g * g * f);
#else
	  *out++ = sqrt(f);
#endif
    }
  }
  return(w+4);
}

static void spec2_sqrt_tilde_dsp(t_spec2_sqrt_tilde *x, t_signal **sp)
{
  int n = (sp[0]->s_n)/2;
  
  dsp_add(spec2_sqrt_tilde_perform, 3, sp[0]->s_vec, sp[0]->s_vec, n);
}

static void *spec2_sqrt_tilde_new(void)
{
  t_spec2_sqrt_tilde *x = (t_spec2_sqrt_tilde *)pd_new(spec2_sqrt_tilde_class);
  
  outlet_new(&x->x_obj, &s_signal);
  x->x_msi = 0.0f;
  return (x);
}

void spec2_sqrt_tilde_setup(void)
{
  spec2_sqrt_tilde_class = class_new(gensym("spec2_sqrt~"), (t_newmethod)spec2_sqrt_tilde_new,
    0, sizeof(t_spec2_sqrt_tilde), 0, 0);
  CLASS_MAINSIGNALIN(spec2_sqrt_tilde_class, t_spec2_sqrt_tilde, x_msi);
  class_addmethod(spec2_sqrt_tilde_class, (t_method)spec2_sqrt_tilde_dsp, gensym("dsp"), 0);
}