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/* Copyright (c) 1997-2003 Miller Puckette.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution.
iemlib2 written by Thomas Musil (c) IEM KUG Graz Austria 2000 - 2003 */
#ifdef NT
#pragma warning( disable : 4244 )
#pragma warning( disable : 4305 )
#endif
#include "m_pd.h"
#include "iemlib.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
/* ------------------------ m2f~ ----------------------------- */
#define M2FTABSIZE 2048
float *iem_m2f_table=(float *)0L;
static t_class *sigm2f_class;
typedef struct _sigm2f
{
t_object x_obj;
float x_msi;
} t_sigm2f;
static void *sigm2f_new(void)
{
t_sigm2f *x = (t_sigm2f *)pd_new(sigm2f_class);
outlet_new(&x->x_obj, gensym("signal"));
x->x_msi = 0;
return (x);
}
static t_int *sigm2f_perform(t_int *w)
{
t_float *in = (t_float *)(w[1]);
t_float *out = (t_float *)(w[2]);
t_sigm2f *x = (t_sigm2f *)(w[3]);
int n = (int)(w[4]);
float *tab = iem_m2f_table, *addr, f1, f2, frac, iinn;
double dphase;
int normhipart;
union tabfudge tf;
tf.tf_d = UNITBIT32;
normhipart = tf.tf_i[HIOFFSET];
#if 0 /* this is the readable version of the code. */
while (n--)
{
iinn = (*in++)*10.0+670.0;
dphase = (double)iinn + UNITBIT32;
tf.tf_d = dphase;
addr = tab + (tf.tf_i[HIOFFSET] & (M2FTABSIZE-1));
tf.tf_i[HIOFFSET] = normhipart;
frac = tf.tf_d - UNITBIT32;
f1 = addr[0];
f2 = addr[1];
*out++ = f1 + frac * (f2 - f1);
}
#endif
#if 1 /* this is the same, unwrapped by hand. */
iinn = (*in++)*10.0+670.0;
dphase = (double)iinn + UNITBIT32;
tf.tf_d = dphase;
addr = tab + (tf.tf_i[HIOFFSET] & (M2FTABSIZE-1));
tf.tf_i[HIOFFSET] = normhipart;
while (--n)
{
iinn = (*in++)*10.0+670.0;
dphase = (double)iinn + UNITBIT32;
frac = tf.tf_d - UNITBIT32;
tf.tf_d = dphase;
f1 = addr[0];
f2 = addr[1];
addr = tab + (tf.tf_i[HIOFFSET] & (M2FTABSIZE-1));
*out++ = f1 + frac * (f2 - f1);
tf.tf_i[HIOFFSET] = normhipart;
}
frac = tf.tf_d - UNITBIT32;
f1 = addr[0];
f2 = addr[1];
*out++ = f1 + frac * (f2 - f1);
#endif
return (w+5);
}
static void sigm2f_dsp(t_sigm2f *x, t_signal **sp)
{
dsp_add(sigm2f_perform, 4, sp[0]->s_vec, sp[1]->s_vec, x, sp[0]->s_n);
}
static void sigm2f_maketable(void)
{
union tabfudge tf;
if(!iem_m2f_table)
{
int i;
float *fp, midi, refexp=440.0*exp(-5.75*log(2.0));
iem_m2f_table = (float *)getbytes(sizeof(float) * (M2FTABSIZE+1));
for(i=0, fp=iem_m2f_table, midi=-67.0; i<=M2FTABSIZE; i++, fp++, midi+=0.1)
*fp = refexp * exp(0.057762265047 * midi);
}
tf.tf_d = UNITBIT32 + 0.5;
if((unsigned)tf.tf_i[LOWOFFSET] != 0x80000000)
bug("m2f~: unexpected machine alignment");
}
void sigm2f_setup(void)
{
sigm2f_class = class_new(gensym("m2f~"), (t_newmethod)sigm2f_new, 0,
sizeof(t_sigm2f), 0, 0);
CLASS_MAINSIGNALIN(sigm2f_class, t_sigm2f, x_msi);
class_addmethod(sigm2f_class, (t_method)sigm2f_dsp, gensym("dsp"), 0);
sigm2f_maketable();
class_sethelpsymbol(sigm2f_class, gensym("iemhelp/help-m2f~"));
}
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