apps/plugins/pdbox/PDa/extra/hlshelf.c

   1 /* (C) Guenter Geiger <geiger@epy.co.at> */
   2
   3
   4 #include <m_pd.h>
   5 #include <math.h>
   6
   7 #ifdef NT
   8 #pragma warning( disable : 4244 )
   9 #pragma warning( disable : 4305 )
  10 #endif
  11
  12 /* ------------------------ hlshelf ----------------------------- */
  13
  14
  15 #ifndef M_PI
  16 #define M_PI 3.141593f
  17 #endif
  18
  19 #define SRATE 44100.0
  20 #define MAX_GAIN 120.0f
  21
  22 static t_class *hlshelf_class;
  23
  24
  25 typedef struct _hlshelf
  26 {
  27      t_object x_obj;
  28      float s_rate;
  29      float s_gain0;
  30      float s_gain1;
  31      float s_gain2;
  32      float s_ltransfq;
  33      float s_htransfq;
  34      float s_lradians;
  35      float s_hradians;
  36 } t_hlshelf;
  37
  38
  39 int hlshelf_check_stability(t_float fb1,
  40                             t_float fb2,
  41                             t_float ff1,
  42                             t_float ff2,
  43                             t_float ff3)
  44 {
  45     float discriminant = fb1 * fb1 + 4 * fb2;
  46
  47     if (discriminant < 0) /* imaginary roots -- resonant filter */
  48     {
  49             /* they're conjugates so we just check that the product
  50             is less than one */
  51         if (fb2 >= -1.0f) goto stable;
  52     }
  53     else    /* real roots */
  54     {
  55             /* check that the parabola 1 - fb1 x - fb2 x^2 has a
  56                 vertex between -1 and 1, and that it's nonnegative
  57                 at both ends, which implies both roots are in [1-,1]. */
  58         if (fb1 <= 2.0f && fb1 >= -2.0f &&
  59             1.0f - fb1 -fb2 >= 0 && 1.0f + fb1 - fb2 >= 0)
  60                 goto stable;
  61     }
  62     return 0;
  63 stable:
  64     return 1;
  65 }
  66
  67
  68 void hlshelf_check(t_hlshelf *x)
  69 {
  70
  71      if(x->s_gain0 - x->s_gain1 > MAX_GAIN) {
  72           x->s_gain0 = x->s_gain1 + MAX_GAIN;
  73           post("setting gain0 to %f",x->s_gain0);
  74      }
  75
  76
  77      if(x->s_gain1 > MAX_GAIN) {
  78           x->s_gain1 = MAX_GAIN;
  79           post("setting gain1 to %f",x->s_gain1);
  80      }
  81
  82      if(x->s_gain2 - x->s_gain1 > MAX_GAIN) {
  83           x->s_gain2 = x->s_gain1 + MAX_GAIN;
  84           post("setting gain2 to %f",x->s_gain2);
  85      }
  86
  87   /* constrain: 0 <= x->s_ltransfq < x->s_htransfq. */
  88      x->s_ltransfq = (x->s_ltransfq < x->s_htransfq) ? x->s_ltransfq : x->s_htransfq - 0.5f;
  89
  90      if (x->s_ltransfq < 0) x->s_ltransfq = 0.0f;
  91
  92      x->s_lradians = M_PI * x->s_ltransfq / x->s_rate;
  93      x->s_hradians= M_PI * (0.5f - (x->s_htransfq / x->s_rate));
  94
  95 }
  96
  97
  98 void hlshelf_bang(t_hlshelf *x)
  99 {
 100      t_atom at[6];
 101      float c0, c1, c2, d0, d1, d2;      /* output coefs */
 102      float a1, a2, b1, b2, g1, g2;      /* temp coefs */
 103      double xf;
 104
 105      hlshelf_check(x);
 106
 107      /* low shelf */
 108      xf = 0.5 * 0.115129255 * (double)(x->s_gain0 - x->s_gain1); /* ln(10) / 20 = 0.115129255 */
 109      if(xf < -200.) /* exp(x) -> 0 */
 110      {
 111           a1 = 1.0f;
 112           b1 = -1.0f;
 113           g1 = 0.0f;
 114      }
 115      else
 116      {
 117           double t = tan(x->s_lradians);
 118           double e = exp(xf);
 119           double r = t / e;
 120           double kr = t * e;
 121
 122           a1 = (r - 1) / (r + 1);
 123           b1 = (kr - 1) / (kr + 1);
 124           g1 = (kr + 1) / (r + 1);
 125      }
 126
 127      /* high shelf */
 128      xf = 0.5 * 0.115129255 * (double)(x->s_gain2 - x->s_gain1); /* ln(10) / 20 = 0.115129255 */
 129      if(xf < -200.) /* exp(x) -> 0 */
 130      {
 131           a2 = -1.0f;
 132           b2 = 1.0f;
 133           g2 = 0.0f;
 134      }
 135      else
 136      {
 137           double t = tan(x->s_hradians);
 138           double e = exp(xf);
 139           double r = t / e;
 140           double kr = t * e;
 141
 142           a2 = (1 - r) / (1 + r);
 143           b2 = (1 - kr) / (1 + kr);
 144           g2 = (1 + kr) / (1 + r);
 145      }
 146
 147      /* form product */
 148      c0 = g1 * g2 * (float)(exp((double)(x->s_gain1) * 0.05f * 2.302585093f));  ;
 149      c1 = a1 + a2;
 150      c2 = a1 * a2;
 151      d0 =  1.0f;
 152      d1 = b1 + b2;
 153      d2 = b1 * b2;
 154
 155      if (!hlshelf_check_stability(-c1/d0,-c2/d0,d0/d0,d1/d0,d2/d0)) {
 156        post("hlshelf: filter unstable -> resetting");
 157        c0=1.;c1=0.;c2=0.;
 158        d0=1.;d1=0.;d2=0.;
 159      }
 160
 161      SETFLOAT(at,-c1/d0);
 162      SETFLOAT(at+1,-c2/d0);
 163      SETFLOAT(at+2,d0/d0);
 164      SETFLOAT(at+3,d1/d0);
 165      SETFLOAT(at+4,d2/d0);
 166
 167      outlet_list(x->x_obj.ob_outlet,&s_list,5,at);
 168 }
 169
 170 void hlshelf_float(t_hlshelf *x,t_floatarg f)
 171 {
 172      x->s_gain0 = f;
 173      hlshelf_bang(x);
 174 }
 175
 176
 177 static void *hlshelf_new(t_symbol* s,t_int argc, t_atom* at)
 178 {
 179     t_hlshelf *x = (t_hlshelf *)pd_new(hlshelf_class);
 180     t_float k0 = atom_getfloat(at);
 181     t_float k1 = atom_getfloat(at+1);
 182     t_float k2 = atom_getfloat(at+2);
 183     t_float f1 = atom_getfloat(at+3);
 184     t_float f2 = atom_getfloat(at+4);
 185
 186
 187     f1 = atom_getfloat(at);
 188     f2 = atom_getfloat(at);
 189
 190     if ((f1 == 0.0f && f2 == 0.0f) || f1 > f2){ /* all gains = 0db */
 191          f1 = 150.0f;
 192          f2 = 5000.0f;
 193     }
 194
 195     if (f1 < 0) f1 = 0.0f;
 196     if (f2 > SRATE) f2 = .5f*SRATE;
 197
 198     x->s_rate = SRATE;          /* srate default  */
 199     x->s_gain0 = k0;
 200     x->s_gain1 = k1;
 201     x->s_gain2 = k2;
 202
 203     x->s_ltransfq = 0.0f;
 204     x->s_htransfq = SRATE/2;
 205
 206     x->s_lradians = M_PI * x->s_ltransfq / x->s_rate;
 207     x->s_hradians= M_PI * (0.5f - (x->s_htransfq / x->s_rate));
 208
 209     floatinlet_new(&x->x_obj, &x->s_gain1);
 210     floatinlet_new(&x->x_obj, &x->s_gain2);
 211     floatinlet_new(&x->x_obj, &x->s_ltransfq);
 212     floatinlet_new(&x->x_obj, &x->s_htransfq);
 213     outlet_new(&x->x_obj, &s_list);
 214
 215     return (x);
 216 }
 217
 218 void hlshelf_setup(void)
 219 {
 220     hlshelf_class = class_new(gensym("hlshelf"), (t_newmethod)hlshelf_new, 0,
 221                                 sizeof(t_hlshelf), 0, A_GIMME, 0);
 222     class_addbang(hlshelf_class,hlshelf_bang);
 223     class_addfloat(hlshelf_class,hlshelf_float);
 224 }
 225
 226
 227 /* (C) Guenter Geiger <geiger@epy.co.at> */
 228
 229
 230 #include <m_pd.h>
 231 #include <math.h>
 232
 233 #ifdef NT
 234 #pragma warning( disable : 4244 )
 235 #pragma warning( disable : 4305 )
 236 #endif
 237
 238 /* ------------------------ hlshelf ----------------------------- */
 239
 240
 241 #ifndef M_PI
 242 #define M_PI 3.141593f
 243 #endif
 244
 245 #define SRATE 44100.0
 246 #define MAX_GAIN 120.0f
 247
 248 static t_class *hlshelf_class;
 249
 250
 251 typedef struct _hlshelf
 252 {
 253      t_object x_obj;
 254      float s_rate;
 255      float s_gain0;
 256      float s_gain1;
 257      float s_gain2;
 258      float s_ltransfq;
 259      float s_htransfq;
 260      float s_lradians;
 261      float s_hradians;
 262 } t_hlshelf;
 263
 264
 265 int hlshelf_check_stability(t_float fb1,
 266                             t_float fb2,
 267                             t_float ff1,
 268                             t_float ff2,
 269                             t_float ff3)
 270 {
 271     float discriminant = fb1 * fb1 + 4 * fb2;
 272
 273     if (discriminant < 0) /* imaginary roots -- resonant filter */
 274     {
 275             /* they're conjugates so we just check that the product
 276             is less than one */
 277         if (fb2 >= -1.0f) goto stable;
 278     }
 279     else    /* real roots */
 280     {
 281             /* check that the parabola 1 - fb1 x - fb2 x^2 has a
 282                 vertex between -1 and 1, and that it's nonnegative
 283                 at both ends, which implies both roots are in [1-,1]. */
 284         if (fb1 <= 2.0f && fb1 >= -2.0f &&
 285             1.0f - fb1 -fb2 >= 0 && 1.0f + fb1 - fb2 >= 0)
 286                 goto stable;
 287     }
 288     return 0;
 289 stable:
 290     return 1;
 291 }
 292
 293
 294 void hlshelf_check(t_hlshelf *x)
 295 {
 296
 297      if(x->s_gain0 - x->s_gain1 > MAX_GAIN) {
 298           x->s_gain0 = x->s_gain1 + MAX_GAIN;
 299           post("setting gain0 to %f",x->s_gain0);
 300      }
 301
 302
 303      if(x->s_gain1 > MAX_GAIN) {
 304           x->s_gain1 = MAX_GAIN;
 305           post("setting gain1 to %f",x->s_gain1);
 306      }
 307
 308      if(x->s_gain2 - x->s_gain1 > MAX_GAIN) {
 309           x->s_gain2 = x->s_gain1 + MAX_GAIN;
 310           post("setting gain2 to %f",x->s_gain2);
 311      }
 312
 313   /* constrain: 0 <= x->s_ltransfq < x->s_htransfq. */
 314      x->s_ltransfq = (x->s_ltransfq < x->s_htransfq) ? x->s_ltransfq : x->s_htransfq - 0.5f;
 315
 316      if (x->s_ltransfq < 0) x->s_ltransfq = 0.0f;
 317
 318      x->s_lradians = M_PI * x->s_ltransfq / x->s_rate;
 319      x->s_hradians= M_PI * (0.5f - (x->s_htransfq / x->s_rate));
 320
 321 }
 322
 323
 324 void hlshelf_bang(t_hlshelf *x)
 325 {
 326      t_atom at[6];
 327      float c0, c1, c2, d0, d1, d2;      /* output coefs */
 328      float a1, a2, b1, b2, g1, g2;      /* temp coefs */
 329      double xf;
 330
 331      hlshelf_check(x);
 332
 333      /* low shelf */
 334      xf = 0.5 * 0.115129255 * (double)(x->s_gain0 - x->s_gain1); /* ln(10) / 20 = 0.115129255 */
 335      if(xf < -200.) /* exp(x) -> 0 */
 336      {
 337           a1 = 1.0f;
 338           b1 = -1.0f;
 339           g1 = 0.0f;
 340      }
 341      else
 342      {
 343           double t = tan(x->s_lradians);
 344           double e = exp(xf);
 345           double r = t / e;
 346           double kr = t * e;
 347
 348           a1 = (r - 1) / (r + 1);
 349           b1 = (kr - 1) / (kr + 1);
 350           g1 = (kr + 1) / (r + 1);
 351      }
 352
 353      /* high shelf */
 354      xf = 0.5 * 0.115129255 * (double)(x->s_gain2 - x->s_gain1); /* ln(10) / 20 = 0.115129255 */
 355      if(xf < -200.) /* exp(x) -> 0 */
 356      {
 357           a2 = -1.0f;
 358           b2 = 1.0f;
 359           g2 = 0.0f;
 360      }
 361      else
 362      {
 363           double t = tan(x->s_hradians);
 364           double e = exp(xf);
 365           double r = t / e;
 366           double kr = t * e;
 367
 368           a2 = (1 - r) / (1 + r);
 369           b2 = (1 - kr) / (1 + kr);
 370           g2 = (1 + kr) / (1 + r);
 371      }
 372
 373      /* form product */
 374      c0 = g1 * g2 * (float)(exp((double)(x->s_gain1) * 0.05f * 2.302585093f));  ;
 375      c1 = a1 + a2;
 376      c2 = a1 * a2;
 377      d0 =  1.0f;
 378      d1 = b1 + b2;
 379      d2 = b1 * b2;
 380
 381      if (!hlshelf_check_stability(-c1/d0,-c2/d0,d0/d0,d1/d0,d2/d0)) {
 382        post("hlshelf: filter unstable -> resetting");
 383        c0=1.;c1=0.;c2=0.;
 384        d0=1.;d1=0.;d2=0.;
 385      }
 386
 387      SETFLOAT(at,-c1/d0);
 388      SETFLOAT(at+1,-c2/d0);
 389      SETFLOAT(at+2,d0/d0);
 390      SETFLOAT(at+3,d1/d0);
 391      SETFLOAT(at+4,d2/d0);
 392
 393      outlet_list(x->x_obj.ob_outlet,&s_list,5,at);
 394 }
 395
 396 void hlshelf_float(t_hlshelf *x,t_floatarg f)
 397 {
 398      x->s_gain0 = f;
 399      hlshelf_bang(x);
 400 }
 401
 402
 403 static void *hlshelf_new(t_symbol* s,t_int argc, t_atom* at)
 404 {
 405     t_hlshelf *x = (t_hlshelf *)pd_new(hlshelf_class);
 406     t_float k0 = atom_getfloat(at);
 407     t_float k1 = atom_getfloat(at+1);
 408     t_float k2 = atom_getfloat(at+2);
 409     t_float f1 = atom_getfloat(at+3);
 410     t_float f2 = atom_getfloat(at+4);
 411
 412
 413     f1 = atom_getfloat(at);
 414     f2 = atom_getfloat(at);
 415
 416     if ((f1 == 0.0f && f2 == 0.0f) || f1 > f2){ /* all gains = 0db */
 417          f1 = 150.0f;
 418          f2 = 5000.0f;
 419     }
 420
 421     if (f1 < 0) f1 = 0.0f;
 422     if (f2 > SRATE) f2 = .5f*SRATE;
 423
 424     x->s_rate = SRATE;          /* srate default  */
 425     x->s_gain0 = k0;
 426     x->s_gain1 = k1;
 427     x->s_gain2 = k2;
 428
 429     x->s_ltransfq = 0.0f;
 430     x->s_htransfq = SRATE/2;
 431
 432     x->s_lradians = M_PI * x->s_ltransfq / x->s_rate;
 433     x->s_hradians= M_PI * (0.5f - (x->s_htransfq / x->s_rate));
 434
 435     floatinlet_new(&x->x_obj, &x->s_gain1);
 436     floatinlet_new(&x->x_obj, &x->s_gain2);
 437     floatinlet_new(&x->x_obj, &x->s_ltransfq);
 438     floatinlet_new(&x->x_obj, &x->s_htransfq);
 439     outlet_new(&x->x_obj, &s_list);
 440
 441     return (x);
 442 }
 443
 444 void hlshelf_setup(void)
 445 {
 446     hlshelf_class = class_new(gensym("hlshelf"), (t_newmethod)hlshelf_new, 0,
 447                                 sizeof(t_hlshelf), 0, A_GIMME, 0);
 448     class_addbang(hlshelf_class,hlshelf_bang);
 449     class_addfloat(hlshelf_class,hlshelf_float);
 450 }
 451
 452