aboutsummaryrefslogtreecommitdiff
path: root/src/iemlib2/fade~.c
blob: 3a2c91babd197cec07fd05713fb167505fd14aae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/* 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, Copyright (c) IEM KUG Graz Austria 2000 - 2005 */

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

/* ------------------------- fade~ ----------------------------- */
/* --- signal lookup tabel object with input range of 0 to 1 --- */
/* ---- converts a linear signal ramp to the half of a :  ------ */
/* -- sine-wave, hanning-wave, squareroot-wave or mixes of it -- */

t_float *iem_fade_tilde_table_lin=(t_float *)0L;
t_float *iem_fade_tilde_table_linsqrt=(t_float *)0L;
t_float *iem_fade_tilde_table_sqrt=(t_float *)0L;
t_float *iem_fade_tilde_table_sin=(t_float *)0L;
t_float *iem_fade_tilde_table_sinhann=(t_float *)0L;
t_float *iem_fade_tilde_table_hann=(t_float *)0L;

static t_class *fade_tilde_class;

typedef struct _fade_tilde
{
  t_object x_obj;
  t_float *x_table;
  t_float x_f;
} t_fade_tilde;

static void fade_tilde_set(t_fade_tilde *x, t_symbol *s)
{
  if(s == gensym("_lin"))
    x->x_table = iem_fade_tilde_table_lin;
  else if(s == gensym("_linsqrt"))
    x->x_table = iem_fade_tilde_table_linsqrt;
  else if(s == gensym("_sqrt"))
    x->x_table = iem_fade_tilde_table_sqrt;
  else if(s == gensym("_sin"))
    x->x_table = iem_fade_tilde_table_sin;
  else if(s == gensym("_sinhann"))
    x->x_table = iem_fade_tilde_table_sinhann;
  else if(s == gensym("_hann"))
    x->x_table = iem_fade_tilde_table_hann;
}

static void *fade_tilde_new(t_symbol *s)
{
  t_fade_tilde *x = (t_fade_tilde *)pd_new(fade_tilde_class);
  outlet_new(&x->x_obj, gensym("signal"));
  x->x_f = 0;
  x->x_table = iem_fade_tilde_table_lin;
  fade_tilde_set(x, s);
  return (x);
}

static t_int *fade_tilde_perform(t_int *w)
{
  t_float *in = (t_float *)(w[1]);
  t_float *out = (t_float *)(w[2]);
  t_fade_tilde *x = (t_fade_tilde *)(w[3]);
  int n = (int)(w[4]);
  t_float *tab = x->x_table, *addr, f1, f2, frac;
  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--)
  {
    dphase = (double)(*in++ * (t_float)(COSTABSIZE) * 0.99999) + UNITBIT32;
    tf.tf_d = dphase;
    addr = tab + (tf.tf_i[HIOFFSET] & (COSTABSIZE-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. */
  dphase = (double)(*in++ * (t_float)(COSTABSIZE) * 0.99999) + UNITBIT32;
  tf.tf_d = dphase;
  addr = tab + (tf.tf_i[HIOFFSET] & (COSTABSIZE-1));
  tf.tf_i[HIOFFSET] = normhipart;
  while (--n)
  {
    dphase = (double)(*in++ * (t_float)(COSTABSIZE) * 0.99999) + UNITBIT32;
    frac = tf.tf_d - UNITBIT32;
    tf.tf_d = dphase;
    f1 = addr[0];
    f2 = addr[1];
    addr = tab + (tf.tf_i[HIOFFSET] & (COSTABSIZE-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 fade_tilde_dsp(t_fade_tilde *x, t_signal **sp)
{
  dsp_add(fade_tilde_perform, 4, sp[0]->s_vec, sp[1]->s_vec, x, sp[0]->s_n);
}

static void fade_tilde_maketable(void)
{
  int i;
  t_float *fp, phase, fff,phsinc = 0.5*3.141592653 / ((t_float)COSTABSIZE*0.99999);
  union tabfudge tf;
  
  if(!iem_fade_tilde_table_sin)
  {
    iem_fade_tilde_table_sin = (t_float *)getbytes(sizeof(t_float) * (COSTABSIZE+1));
    for(i=COSTABSIZE+1, fp=iem_fade_tilde_table_sin, phase=0; i--; fp++, phase+=phsinc)
      *fp = sin(phase);
  }
  if(!iem_fade_tilde_table_sinhann)
  {
    iem_fade_tilde_table_sinhann = (t_float *)getbytes(sizeof(t_float) * (COSTABSIZE+1));
    for(i=COSTABSIZE+1, fp=iem_fade_tilde_table_sinhann, phase=0; i--; fp++, phase+=phsinc)
    {
      fff = sin(phase);
      *fp = fff*sqrt(fff);
    }
  }
  if(!iem_fade_tilde_table_hann)
  {
    iem_fade_tilde_table_hann = (t_float *)getbytes(sizeof(t_float) * (COSTABSIZE+1));
    for(i=COSTABSIZE+1, fp=iem_fade_tilde_table_hann, phase=0; i--; fp++, phase+=phsinc)
    {
      fff = sin(phase);
      *fp = fff*fff;
    }
  }
  phsinc = 1.0 / ((t_float)COSTABSIZE*0.99999);
  if(!iem_fade_tilde_table_lin)
  {
    iem_fade_tilde_table_lin = (t_float *)getbytes(sizeof(t_float) * (COSTABSIZE+1));
    for(i=COSTABSIZE+1, fp=iem_fade_tilde_table_lin, phase=0; i--; fp++, phase+=phsinc)
      *fp = phase;
  }
  if(!iem_fade_tilde_table_linsqrt)
  {
    iem_fade_tilde_table_linsqrt = (t_float *)getbytes(sizeof(t_float) * (COSTABSIZE+1));
    for(i=COSTABSIZE+1, fp=iem_fade_tilde_table_linsqrt, phase=0; i--; fp++, phase+=phsinc)
      *fp = pow(phase, 0.75);
  }
  if(!iem_fade_tilde_table_sqrt)
  {
    iem_fade_tilde_table_sqrt = (t_float *)getbytes(sizeof(t_float) * (COSTABSIZE+1));
    for(i=COSTABSIZE+1, fp=iem_fade_tilde_table_sqrt, phase=0; i--; fp++, phase+=phsinc)
      *fp = sqrt(phase);
  }
  tf.tf_d = UNITBIT32 + 0.5;
  if((unsigned)tf.tf_i[LOWOFFSET] != 0x80000000)
    bug("fade~: unexpected machine alignment");
}

void fade_tilde_setup(void)
{
  fade_tilde_class = class_new(gensym("fade~"), (t_newmethod)fade_tilde_new, 0,
    sizeof(t_fade_tilde), 0, A_DEFSYM, 0);
  CLASS_MAINSIGNALIN(fade_tilde_class, t_fade_tilde, x_f);
  class_addmethod(fade_tilde_class, (t_method)fade_tilde_dsp, gensym("dsp"), 0);
  class_addmethod(fade_tilde_class, (t_method)fade_tilde_set, gensym("set"), A_DEFSYM, 0);
  class_sethelpsymbol(fade_tilde_class, gensym("iemhelp/help-fade~"));
  fade_tilde_maketable();
}