libs/plugins/a-comp.lv2/a-comp.c

   1 /* a-comp
   2  * Copyright (C) 2016 Damien Zammit <damien@zamaudio.com>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <math.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <stdbool.h>
  19
  20 #ifdef LV2_EXTENDED
  21 #include <cairo/cairo.h>
  22 #include "ardour/lv2_extensions.h"
  23 #endif
  24
  25 #include "lv2/lv2plug.in/ns/lv2core/lv2.h"
  26
  27 #define ACOMP_URI               "urn:ardour:a-comp"
  28 #define ACOMP_STEREO_URI        "urn:ardour:a-comp#stereo"
  29
  30 #ifndef M_PI
  31 #  define M_PI 3.14159265358979323846
  32 #endif
  33
  34 #ifdef COMPILER_MSVC
  35 #include <float.h>
  36 #define isfinite_local(val) (bool)_finite((double)val)
  37 #else
  38 #define isfinite_local isfinite
  39 #endif
  40
  41 typedef enum {
  42         ACOMP_ATTACK = 0,
  43         ACOMP_RELEASE,
  44         ACOMP_KNEE,
  45         ACOMP_RATIO,
  46         ACOMP_THRESHOLD,
  47         ACOMP_MAKEUP,
  48
  49         ACOMP_GAINR,
  50         ACOMP_OUTLEVEL,
  51         ACOMP_SIDECHAIN,
  52         ACOMP_ENABLE,
  53
  54         ACOMP_A0,
  55         ACOMP_A1,
  56         ACOMP_A2,
  57         ACOMP_A3,
  58         ACOMP_A4,
  59 } PortIndex;
  60
  61 typedef struct {
  62         float* attack;
  63         float* release;
  64         float* knee;
  65         float* ratio;
  66         float* thresdb;
  67         float* makeup;
  68
  69         float* gainr;
  70         float* outlevel;
  71         float* sidechain;
  72         float* enable;
  73
  74         float* input0;
  75         float* input1;
  76         float* sc;
  77         float* output0;
  78         float* output1;
  79
  80         float srate;
  81         float old_yl;
  82         float old_y1;
  83         float old_yg;
  84
  85         float makeup_gain;
  86         float tau;
  87
  88 #ifdef LV2_EXTENDED
  89         LV2_Inline_Display_Image_Surface surf;
  90         bool                     need_expose;
  91         cairo_surface_t*         display;
  92         LV2_Inline_Display*      queue_draw;
  93         uint32_t                 w, h;
  94
  95         /* ports pointers are only valid during run so we'll
  96          * have to cache them for the display, besides
  97          * we do want to check for changes
  98          */
  99         float v_knee;
 100         float v_ratio;
 101         float v_thresdb;
 102         float v_gainr;
 103         float v_makeup;
 104         float v_lvl;
 105         float v_lvl_in;
 106         float v_lvl_out;
 107 #endif
 108 } AComp;
 109
 110 static LV2_Handle
 111 instantiate(const LV2_Descriptor* descriptor,
 112             double rate,
 113             const char* bundle_path,
 114             const LV2_Feature* const* features)
 115 {
 116         AComp* acomp = (AComp*)calloc(1, sizeof(AComp));
 117
 118         for (int i=0; features[i]; ++i) {
 119 #ifdef LV2_EXTENDED
 120                 if (!strcmp(features[i]->URI, LV2_INLINEDISPLAY__queue_draw)) {
 121                         acomp->queue_draw = (LV2_Inline_Display*) features[i]->data;
 122                 }
 123 #endif
 124         }
 125
 126         acomp->srate = rate;
 127         acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
 128         acomp->tau = (1.0 - exp (-2.f * M_PI * 25.f / acomp->srate));
 129 #ifdef LV2_EXTENDED
 130         acomp->need_expose = true;
 131 #endif
 132
 133         return (LV2_Handle)acomp;
 134 }
 135
 136
 137 static void
 138 connect_port(LV2_Handle instance,
 139              uint32_t port,
 140              void* data)
 141 {
 142         AComp* acomp = (AComp*)instance;
 143
 144         switch ((PortIndex)port) {
 145                 case ACOMP_ATTACK:
 146                         acomp->attack = (float*)data;
 147                         break;
 148                 case ACOMP_RELEASE:
 149                         acomp->release = (float*)data;
 150                         break;
 151                 case ACOMP_KNEE:
 152                         acomp->knee = (float*)data;
 153                         break;
 154                 case ACOMP_RATIO:
 155                         acomp->ratio = (float*)data;
 156                         break;
 157                 case ACOMP_THRESHOLD:
 158                         acomp->thresdb = (float*)data;
 159                         break;
 160                 case ACOMP_MAKEUP:
 161                         acomp->makeup = (float*)data;
 162                         break;
 163                 case ACOMP_GAINR:
 164                         acomp->gainr = (float*)data;
 165                         break;
 166                 case ACOMP_OUTLEVEL:
 167                         acomp->outlevel = (float*)data;
 168                         break;
 169                 case ACOMP_SIDECHAIN:
 170                         acomp->sidechain = (float*)data;
 171                         break;
 172                 case ACOMP_ENABLE:
 173                         acomp->enable = (float*)data;
 174                         break;
 175                 default:
 176                         break;
 177         }
 178 }
 179
 180 static void
 181 connect_mono(LV2_Handle instance,
 182              uint32_t port,
 183              void* data)
 184 {
 185         AComp* acomp = (AComp*)instance;
 186         connect_port (instance, port, data);
 187
 188         switch ((PortIndex)port) {
 189                 case ACOMP_A0:
 190                         acomp->input0 = (float*)data;
 191                         break;
 192                 case ACOMP_A1:
 193                         acomp->sc = (float*)data;
 194                         break;
 195                 case ACOMP_A2:
 196                         acomp->output0 = (float*)data;
 197                         break;
 198         default:
 199                 break;
 200         }
 201 }
 202
 203 static void
 204 connect_stereo(LV2_Handle instance,
 205                uint32_t port,
 206                void* data)
 207 {
 208         AComp* acomp = (AComp*)instance;
 209         connect_port (instance, port, data);
 210
 211         switch ((PortIndex)port) {
 212                 case ACOMP_A0:
 213                         acomp->input0 = (float*)data;
 214                         break;
 215                 case ACOMP_A1:
 216                         acomp->input1 = (float*)data;
 217                         break;
 218                 case ACOMP_A2:
 219                         acomp->sc = (float*)data;
 220                         break;
 221                 case ACOMP_A3:
 222                         acomp->output0 = (float*)data;
 223                         break;
 224                 case ACOMP_A4:
 225                         acomp->output1 = (float*)data;
 226                         break;
 227         default:
 228                 break;
 229         }
 230 }
 231
 232 // Force already-denormal float value to zero
 233 static inline float
 234 sanitize_denormal(float value) {
 235         if (!isnormal(value)) {
 236                 value = 0.f;
 237         }
 238         return value;
 239 }
 240
 241 static inline float
 242 from_dB(float gdb) {
 243         return (exp(gdb/20.f*log(10.f)));
 244 }
 245
 246 static inline float
 247 to_dB(float g) {
 248         return (20.f*log10(g));
 249 }
 250
 251 static void
 252 activate(LV2_Handle instance)
 253 {
 254         AComp* acomp = (AComp*)instance;
 255
 256         *(acomp->gainr) = 0.0f;
 257         *(acomp->outlevel) = -45.0f;
 258         acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
 259 }
 260
 261 static void
 262 run_mono(LV2_Handle instance, uint32_t n_samples)
 263 {
 264         AComp* acomp = (AComp*)instance;
 265
 266         const float* const input = acomp->input0;
 267         const float* const sc = acomp->sc;
 268         float* const output = acomp->output0;
 269
 270         float srate = acomp->srate;
 271         float width = (6.f * *(acomp->knee)) + 0.01;
 272         float cdb=0.f;
 273         float attack_coeff = exp(-1000.f/(*(acomp->attack) * srate));
 274         float release_coeff = exp(-1000.f/(*(acomp->release) * srate));
 275
 276         float max = 0.f;
 277         float lgaininp = 0.f;
 278         float Lgain = 1.f;
 279         float Lxg, Lxl, Lyg, Lyl, Ly1;
 280         int usesidechain = (*(acomp->sidechain) <= 0.f) ? 0 : 1;
 281         uint32_t i;
 282         float ingain;
 283         float in0;
 284         float sc0;
 285
 286         float ratio = *acomp->ratio;
 287         float thresdb = *acomp->thresdb;
 288         float makeup = *acomp->makeup;
 289         float makeup_target = from_dB(makeup);
 290         float makeup_gain = acomp->makeup_gain;
 291
 292         const float tau = acomp->tau;
 293
 294         if (*acomp->enable <= 0) {
 295                 ratio = 1.f;
 296                 thresdb = 0.f;
 297                 makeup = 0.f;
 298                 makeup_target = 1.f;
 299         }
 300
 301 #ifdef LV2_EXTENDED
 302         if (acomp->v_knee != *acomp->knee) {
 303                 acomp->v_knee = *acomp->knee;
 304                 acomp->need_expose = true;
 305         }
 306
 307         if (acomp->v_ratio != ratio) {
 308                 acomp->v_ratio = ratio;
 309                 acomp->need_expose = true;
 310         }
 311
 312         if (acomp->v_thresdb != thresdb) {
 313                 acomp->v_thresdb = thresdb;
 314                 acomp->need_expose = true;
 315         }
 316
 317         if (acomp->v_makeup != makeup) {
 318                 acomp->v_makeup = makeup;
 319                 acomp->need_expose = true;
 320         }
 321 #endif
 322
 323         float in_peak = 0;
 324         acomp->v_gainr = 0.0;
 325
 326         for (i = 0; i < n_samples; i++) {
 327                 in0 = input[i];
 328                 sc0 = sc[i];
 329                 ingain = usesidechain ? fabs(sc0) : fabs(in0);
 330                 in_peak = fmaxf (in_peak, ingain);
 331                 Lyg = 0.f;
 332                 Lxg = (ingain==0.f) ? -160.f : to_dB(ingain);
 333                 Lxg = sanitize_denormal(Lxg);
 334
 335
 336                 if (2.f*(Lxg-thresdb) < -width) {
 337                         Lyg = Lxg;
 338                 } else if (2.f*(Lxg-thresdb) > width) {
 339                         Lyg = thresdb + (Lxg-thresdb)/ratio;
 340                         Lyg = sanitize_denormal(Lyg);
 341                 } else {
 342                         Lyg = Lxg + (1.f/ratio-1.f)*(Lxg-thresdb+width/2.f)*(Lxg-thresdb+width/2.f)/(2.f*width);
 343                 }
 344
 345                 Lxl = Lxg - Lyg;
 346
 347                 acomp->old_y1 = sanitize_denormal(acomp->old_y1);
 348                 acomp->old_yl = sanitize_denormal(acomp->old_yl);
 349                 Ly1 = fmaxf(Lxl, release_coeff * acomp->old_y1+(1.f-release_coeff)*Lxl);
 350                 Lyl = attack_coeff * acomp->old_yl+(1.f-attack_coeff)*Ly1;
 351                 Ly1 = sanitize_denormal(Ly1);
 352                 Lyl = sanitize_denormal(Lyl);
 353
 354                 cdb = -Lyl;
 355                 Lgain = from_dB(cdb);
 356
 357                 *(acomp->gainr) = Lyl;
 358                 if (Lyl > acomp->v_gainr) {
 359                         acomp->v_gainr = Lyl;
 360                 }
 361
 362                 lgaininp = in0 * Lgain;
 363
 364                 makeup_gain += tau * (makeup_target - makeup_gain) + 1e-12;
 365                 output[i] = lgaininp * makeup_gain;
 366
 367                 max = (fabsf(output[i]) > max) ? fabsf(output[i]) : sanitize_denormal(max);
 368
 369                 // TODO re-use local variables on stack
 370                 // store values back to acomp at the end of the inner-loop
 371                 acomp->old_yl = Lyl;
 372                 acomp->old_y1 = Ly1;
 373                 acomp->old_yg = Lyg;
 374         }
 375
 376         *(acomp->outlevel) = (max < 0.0056f) ? -45.f : to_dB(max);
 377         acomp->makeup_gain = makeup_gain;
 378
 379 #ifdef LV2_EXTENDED
 380         acomp->v_lvl += .1 * (in_peak - acomp->v_lvl) + 1e-12;  // crude LPF TODO use n_samples/rate TC
 381         if (!isfinite_local (acomp->v_lvl)) {
 382                 acomp->v_lvl = 0.f;
 383         }
 384         const float v_lvl_in = (acomp->v_lvl < 0.001f) ? -60.f : to_dB(acomp->v_lvl);
 385         const float v_lvl_out = (max < 0.001f) ? -60.f : to_dB(max);
 386         if (fabsf (acomp->v_lvl_out - v_lvl_out) >= 1 || fabsf (acomp->v_lvl_in - v_lvl_in) >= 1) {
 387                 // >= 1dB difference
 388                 acomp->need_expose = true;
 389                 acomp->v_lvl_in = v_lvl_in;
 390                 acomp->v_lvl_out = v_lvl_out - to_dB(makeup_gain);
 391         }
 392         if (acomp->need_expose && acomp->queue_draw) {
 393                 acomp->need_expose = false;
 394                 acomp->queue_draw->queue_draw (acomp->queue_draw->handle);
 395         }
 396 #endif
 397 }
 398
 399 static void
 400 run_stereo(LV2_Handle instance, uint32_t n_samples)
 401 {
 402         AComp* acomp = (AComp*)instance;
 403
 404         const float* const input0 = acomp->input0;
 405         const float* const input1 = acomp->input1;
 406         const float* const sc = acomp->sc;
 407         float* const output0 = acomp->output0;
 408         float* const output1 = acomp->output1;
 409
 410         float srate = acomp->srate;
 411         float width = (6.f * *(acomp->knee)) + 0.01;
 412         float cdb=0.f;
 413         float attack_coeff = exp(-1000.f/(*(acomp->attack) * srate));
 414         float release_coeff = exp(-1000.f/(*(acomp->release) * srate));
 415
 416         float max = 0.f;
 417         float lgaininp = 0.f;
 418         float rgaininp = 0.f;
 419         float Lgain = 1.f;
 420         float Lxg, Lxl, Lyg, Lyl, Ly1;
 421         int usesidechain = (*(acomp->sidechain) <= 0.f) ? 0 : 1;
 422         uint32_t i;
 423         float ingain;
 424         float in0;
 425         float in1;
 426         float sc0;
 427         float maxabslr;
 428
 429         float ratio = *acomp->ratio;
 430         float thresdb = *acomp->thresdb;
 431         float makeup = *acomp->makeup;
 432         float makeup_target = from_dB(makeup);
 433         float makeup_gain = acomp->makeup_gain;
 434
 435         const float tau = acomp->tau;
 436
 437         if (*acomp->enable <= 0) {
 438                 ratio = 1.f;
 439                 thresdb = 0.f;
 440                 makeup = 0.f;
 441                 makeup_target = 1.f;
 442         }
 443
 444 #ifdef LV2_EXTENDED
 445         if (acomp->v_knee != *acomp->knee) {
 446                 acomp->v_knee = *acomp->knee;
 447                 acomp->need_expose = true;
 448         }
 449
 450         if (acomp->v_ratio != ratio) {
 451                 acomp->v_ratio = ratio;
 452                 acomp->need_expose = true;
 453         }
 454
 455         if (acomp->v_thresdb != thresdb) {
 456                 acomp->v_thresdb = thresdb;
 457                 acomp->need_expose = true;
 458         }
 459
 460         if (acomp->v_makeup != makeup) {
 461                 acomp->v_makeup = makeup;
 462                 acomp->need_expose = true;
 463         }
 464 #endif
 465
 466         float in_peak = 0;
 467         acomp->v_gainr = 0.0;
 468
 469         for (i = 0; i < n_samples; i++) {
 470                 in0 = input0[i];
 471                 in1 = input1[i];
 472                 sc0 = sc[i];
 473                 maxabslr = fmaxf(fabs(in0), fabs(in1));
 474                 ingain = usesidechain ? fabs(sc0) : maxabslr;
 475                 in_peak = fmaxf (in_peak, ingain);
 476                 Lyg = 0.f;
 477                 Lxg = (ingain==0.f) ? -160.f : to_dB(ingain);
 478                 Lxg = sanitize_denormal(Lxg);
 479
 480
 481                 if (2.f*(Lxg-thresdb) < -width) {
 482                         Lyg = Lxg;
 483                 } else if (2.f*(Lxg-thresdb) > width) {
 484                         Lyg = thresdb + (Lxg-thresdb)/ratio;
 485                         Lyg = sanitize_denormal(Lyg);
 486                 } else {
 487                         Lyg = Lxg + (1.f/ratio-1.f)*(Lxg-thresdb+width/2.f)*(Lxg-thresdb+width/2.f)/(2.f*width);
 488                 }
 489
 490                 Lxl = Lxg - Lyg;
 491
 492                 acomp->old_y1 = sanitize_denormal(acomp->old_y1);
 493                 acomp->old_yl = sanitize_denormal(acomp->old_yl);
 494                 Ly1 = fmaxf(Lxl, release_coeff * acomp->old_y1+(1.f-release_coeff)*Lxl);
 495                 Lyl = attack_coeff * acomp->old_yl+(1.f-attack_coeff)*Ly1;
 496                 Ly1 = sanitize_denormal(Ly1);
 497                 Lyl = sanitize_denormal(Lyl);
 498
 499                 cdb = -Lyl;
 500                 Lgain = from_dB(cdb);
 501
 502                 *(acomp->gainr) = Lyl;
 503                 if (Lyl > acomp->v_gainr) {
 504                         acomp->v_gainr = Lyl;
 505                 }
 506
 507                 lgaininp = in0 * Lgain;
 508                 rgaininp = in1 * Lgain;
 509
 510                 makeup_gain += tau * (makeup_target - makeup_gain) + 1e-12;
 511
 512                 output0[i] = lgaininp * makeup_gain;
 513                 output1[i] = rgaininp * makeup_gain;
 514
 515                 max = (fmaxf(fabs(output0[i]), fabs(output1[i])) > max) ? fmaxf(fabs(output0[i]), fabs(output1[i])) : sanitize_denormal(max);
 516
 517                 // TODO re-use local variables on stack
 518                 // store values back to acomp at the end of the inner-loop
 519                 acomp->old_yl = Lyl;
 520                 acomp->old_y1 = Ly1;
 521                 acomp->old_yg = Lyg;
 522         }
 523
 524         *(acomp->outlevel) = (max < 0.0056f) ? -45.f : to_dB(max);
 525         acomp->makeup_gain = makeup_gain;
 526
 527 #ifdef LV2_EXTENDED
 528         acomp->v_lvl += .1 * (in_peak - acomp->v_lvl) + 1e-12;  // crude LPF TODO use n_samples/rate TC
 529         if (!isfinite_local (acomp->v_lvl)) {
 530                 acomp->v_lvl = 0.f;
 531         }
 532         const float v_lvl_in = (acomp->v_lvl < 0.001f) ? -60.f : to_dB(acomp->v_lvl);
 533         const float v_lvl_out = (max < 0.001f) ? -60.f : to_dB(max);
 534         if (fabsf (acomp->v_lvl_out - v_lvl_out) >= 1 || fabsf (acomp->v_lvl_in - v_lvl_in) >= 1) {
 535                 // >= 1dB difference
 536                 acomp->need_expose = true;
 537                 acomp->v_lvl_in = v_lvl_in;
 538                 acomp->v_lvl_out = v_lvl_out - to_dB(makeup_gain);
 539         }
 540         if (acomp->need_expose && acomp->queue_draw) {
 541                 acomp->need_expose = false;
 542                 acomp->queue_draw->queue_draw (acomp->queue_draw->handle);
 543         }
 544 #endif
 545 }
 546
 547 static void
 548 deactivate(LV2_Handle instance)
 549 {
 550         activate(instance);
 551 }
 552
 553 static void
 554 cleanup(LV2_Handle instance)
 555 {
 556 #ifdef LV2_EXTENDED
 557         AComp* acomp = (AComp*)instance;
 558         if (acomp->display) {
 559                 cairo_surface_destroy (acomp->display);
 560         }
 561 #endif
 562
 563         free(instance);
 564 }
 565
 566
 567 #ifndef MIN
 568 #define MIN(A,B) ((A) < (B)) ? (A) : (B)
 569 #endif
 570
 571 #ifdef LV2_EXTENDED
 572 static float
 573 comp_curve (AComp* self, float xg) {
 574         const float knee = self->v_knee;
 575         const float ratio = self->v_ratio;
 576         const float thresdb = self->v_thresdb;
 577         const float makeup = self->v_makeup;
 578
 579         const float width = 6.f * knee + 0.01f;
 580         float yg = 0.f;
 581
 582         if (2.f * (xg - thresdb) < -width) {
 583                 yg = xg;
 584         } else if (2.f * (xg - thresdb) > width) {
 585                 yg = thresdb + (xg - thresdb) / ratio;
 586         } else {
 587                 yg = xg + (1.f / ratio - 1.f ) * (xg - thresdb + width / 2.f) * (xg - thresdb + width / 2.f) / (2.f * width);
 588         }
 589
 590         yg += makeup;
 591
 592         return yg;
 593 }
 594
 595 static LV2_Inline_Display_Image_Surface *
 596 render_inline (LV2_Handle instance, uint32_t w, uint32_t max_h)
 597 {
 598         AComp* self = (AComp*)instance;
 599         uint32_t h = MIN (w, max_h);
 600
 601         const float makeup_thres = self->v_thresdb + self->v_makeup;
 602
 603         if (!self->display || self->w != w || self->h != h) {
 604                 if (self->display) cairo_surface_destroy(self->display);
 605                 self->display = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, w, h);
 606                 self->w = w;
 607                 self->h = h;
 608         }
 609
 610         cairo_t* cr = cairo_create (self->display);
 611
 612         // clear background
 613         cairo_rectangle (cr, 0, 0, w, h);
 614         cairo_set_source_rgba (cr, .2, .2, .2, 1.0);
 615         cairo_fill (cr);
 616
 617         cairo_set_line_width(cr, 1.0);
 618
 619         // draw grid 10dB steps
 620         const double dash1[] = {1, 2};
 621         const double dash2[] = {1, 3};
 622         cairo_save (cr);
 623         cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND);
 624         cairo_set_dash(cr, dash2, 2, 2);
 625         cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 626
 627         for (uint32_t d = 1; d < 7; ++d) {
 628                 const float x = -.5 + floorf (w * (d * 10.f / 70.f));
 629                 const float y = -.5 + floorf (h * (d * 10.f / 70.f));
 630
 631                 cairo_move_to (cr, x, 0);
 632                 cairo_line_to (cr, x, h);
 633                 cairo_stroke (cr);
 634
 635                 cairo_move_to (cr, 0, y);
 636                 cairo_line_to (cr, w, y);
 637                 cairo_stroke (cr);
 638         }
 639         cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 1.0);
 640         cairo_set_dash(cr, dash1, 2, 2);
 641         if (self->v_thresdb < 0) {
 642                 const float y = -.5 + floorf (h * ((makeup_thres - 10.f) / -70.f));
 643                 cairo_move_to (cr, 0, y);
 644                 cairo_line_to (cr, w, y);
 645                 cairo_stroke (cr);
 646         }
 647         // diagonal unity
 648         cairo_move_to (cr, 0, h);
 649         cairo_line_to (cr, w, 0);
 650         cairo_stroke (cr);
 651         cairo_restore (cr);
 652
 653         { // 0, 0
 654                 cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 655                 const float x = -.5 + floorf (w * (60.f / 70.f));
 656                 const float y = -.5 + floorf (h * (10.f / 70.f));
 657                 cairo_move_to (cr, x, 0);
 658                 cairo_line_to (cr, x, h);
 659                 cairo_stroke (cr);
 660                 cairo_move_to (cr, 0, y);
 661                 cairo_line_to (cr, w, y);
 662                 cairo_stroke (cr);
 663         }
 664
 665         { // GR
 666                 const float x = -.5 + floorf (w * (62.5f / 70.f));
 667                 const float y = -.5 + floorf (h * (10.0f / 70.f));
 668                 const float wd = floorf (w * (5.f / 70.f));
 669                 const float ht = floorf (h * (55.f / 70.f));
 670                 cairo_rectangle (cr, x, y, wd, ht);
 671                 cairo_fill (cr);
 672
 673                 const float h_gr = fminf (ht, floorf (h * self->v_gainr / 70.f));
 674                 cairo_set_source_rgba (cr, 0.95, 0.0, 0.0, 1.0);
 675                 cairo_rectangle (cr, x, y, wd, h_gr);
 676                 cairo_fill (cr);
 677                 cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 678                 cairo_rectangle (cr, x, y, wd, ht);
 679                 cairo_set_source_rgba (cr, 0.75, 0.75, 0.75, 1.0);
 680                 cairo_stroke (cr);
 681         }
 682
 683         // draw curve
 684         cairo_set_source_rgba (cr, .8, .8, .8, 1.0);
 685         cairo_move_to (cr, 0, h);
 686
 687         for (uint32_t x = 0; x < w; ++x) {
 688                 // plot -60..+10  dB
 689                 const float x_db = 70.f * (-1.f + x / (float)w) + 10.f;
 690                 const float y_db = comp_curve (self, x_db) - 10.f;
 691                 const float y = h * (y_db / -70.f);
 692                 cairo_line_to (cr, x, y);
 693         }
 694         cairo_stroke_preserve (cr);
 695
 696         cairo_line_to (cr, w, h);
 697         cairo_close_path (cr);
 698         cairo_clip (cr);
 699
 700         // draw signal level & reduction/gradient
 701         const float top = comp_curve (self, 0) - 10.f;
 702         cairo_pattern_t* pat = cairo_pattern_create_linear (0.0, 0.0, 0.0, h);
 703         if (top > makeup_thres - 10.f) {
 704                 cairo_pattern_add_color_stop_rgba (pat, 0.0, 0.8, 0.1, 0.1, 0.5);
 705                 cairo_pattern_add_color_stop_rgba (pat, top / -70.f, 0.8, 0.1, 0.1, 0.5);
 706         }
 707         if (self->v_knee > 0) {
 708                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres -10.f) / -70.f), 0.7, 0.7, 0.2, 0.5);
 709                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres - self->v_knee - 10.f) / -70.f), 0.5, 0.5, 0.5, 0.5);
 710         } else {
 711                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres - 10.f)/ -70.f), 0.7, 0.7, 0.2, 0.5);
 712                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres - 10.01f) / -70.f), 0.5, 0.5, 0.5, 0.5);
 713         }
 714         cairo_pattern_add_color_stop_rgba (pat, 1.0, 0.5, 0.5, 0.5, 0.5);
 715
 716         // maybe cut off at x-position?
 717         const float x = w * (self->v_lvl_in + 60) / 70.f;
 718         const float y = x + h*self->v_makeup;
 719         cairo_rectangle (cr, 0, h - y, x, y);
 720         if (self->v_ratio > 1.0) {
 721                 cairo_set_source (cr, pat);
 722         } else {
 723                 cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 724         }
 725         cairo_fill (cr);
 726
 727         cairo_pattern_destroy (pat); // TODO cache pattern
 728
 729
 730         // create RGBA surface
 731         cairo_destroy (cr);
 732         cairo_surface_flush (self->display);
 733         self->surf.width = cairo_image_surface_get_width (self->display);
 734         self->surf.height = cairo_image_surface_get_height (self->display);
 735         self->surf.stride = cairo_image_surface_get_stride (self->display);
 736         self->surf.data = cairo_image_surface_get_data  (self->display);
 737
 738         return &self->surf;
 739 }
 740 #endif
 741
 742 static const void*
 743 extension_data(const char* uri)
 744 {
 745 #ifdef LV2_EXTENDED
 746         static const LV2_Inline_Display_Interface display  = { render_inline };
 747         if (!strcmp(uri, LV2_INLINEDISPLAY__interface)) {
 748                 return &display;
 749         }
 750 #endif
 751         return NULL;
 752 }
 753
 754 static const LV2_Descriptor descriptor_mono = {
 755         ACOMP_URI,
 756         instantiate,
 757         connect_mono,
 758         activate,
 759         run_mono,
 760         deactivate,
 761         cleanup,
 762         extension_data
 763 };
 764
 765 static const LV2_Descriptor descriptor_stereo = {
 766         ACOMP_STEREO_URI,
 767         instantiate,
 768         connect_stereo,
 769         activate,
 770         run_stereo,
 771         deactivate,
 772         cleanup,
 773         extension_data
 774 };
 775
 776 LV2_SYMBOL_EXPORT
 777 const LV2_Descriptor*
 778 lv2_descriptor(uint32_t index)
 779 {
 780         switch (index) {
 781         case 0:
 782                 return &descriptor_mono;
 783         case 1:
 784                 return &descriptor_stereo;
 785         default:
 786                 return NULL;
 787         }
 788 }