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_lv1;
 106         float v_lvl_in;
 107         float v_lvl_out;
 108 #endif
 109 } AComp;
 110
 111 static LV2_Handle
 112 instantiate(const LV2_Descriptor* descriptor,
 113             double rate,
 114             const char* bundle_path,
 115             const LV2_Feature* const* features)
 116 {
 117         AComp* acomp = (AComp*)calloc(1, sizeof(AComp));
 118
 119         for (int i=0; features[i]; ++i) {
 120 #ifdef LV2_EXTENDED
 121                 if (!strcmp(features[i]->URI, LV2_INLINEDISPLAY__queue_draw)) {
 122                         acomp->queue_draw = (LV2_Inline_Display*) features[i]->data;
 123                 }
 124 #endif
 125         }
 126
 127         acomp->srate = rate;
 128         acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
 129         acomp->tau = (1.0 - exp (-2.f * M_PI * 25.f / acomp->srate));
 130 #ifdef LV2_EXTENDED
 131         acomp->need_expose = true;
 132 #endif
 133
 134         return (LV2_Handle)acomp;
 135 }
 136
 137
 138 static void
 139 connect_port(LV2_Handle instance,
 140              uint32_t port,
 141              void* data)
 142 {
 143         AComp* acomp = (AComp*)instance;
 144
 145         switch ((PortIndex)port) {
 146                 case ACOMP_ATTACK:
 147                         acomp->attack = (float*)data;
 148                         break;
 149                 case ACOMP_RELEASE:
 150                         acomp->release = (float*)data;
 151                         break;
 152                 case ACOMP_KNEE:
 153                         acomp->knee = (float*)data;
 154                         break;
 155                 case ACOMP_RATIO:
 156                         acomp->ratio = (float*)data;
 157                         break;
 158                 case ACOMP_THRESHOLD:
 159                         acomp->thresdb = (float*)data;
 160                         break;
 161                 case ACOMP_MAKEUP:
 162                         acomp->makeup = (float*)data;
 163                         break;
 164                 case ACOMP_GAINR:
 165                         acomp->gainr = (float*)data;
 166                         break;
 167                 case ACOMP_OUTLEVEL:
 168                         acomp->outlevel = (float*)data;
 169                         break;
 170                 case ACOMP_SIDECHAIN:
 171                         acomp->sidechain = (float*)data;
 172                         break;
 173                 case ACOMP_ENABLE:
 174                         acomp->enable = (float*)data;
 175                         break;
 176                 default:
 177                         break;
 178         }
 179 }
 180
 181 static void
 182 connect_mono(LV2_Handle instance,
 183              uint32_t port,
 184              void* data)
 185 {
 186         AComp* acomp = (AComp*)instance;
 187         connect_port (instance, port, data);
 188
 189         switch ((PortIndex)port) {
 190                 case ACOMP_A0:
 191                         acomp->input0 = (float*)data;
 192                         break;
 193                 case ACOMP_A1:
 194                         acomp->sc = (float*)data;
 195                         break;
 196                 case ACOMP_A2:
 197                         acomp->output0 = (float*)data;
 198                         break;
 199         default:
 200                 break;
 201         }
 202 }
 203
 204 static void
 205 connect_stereo(LV2_Handle instance,
 206                uint32_t port,
 207                void* data)
 208 {
 209         AComp* acomp = (AComp*)instance;
 210         connect_port (instance, port, data);
 211
 212         switch ((PortIndex)port) {
 213                 case ACOMP_A0:
 214                         acomp->input0 = (float*)data;
 215                         break;
 216                 case ACOMP_A1:
 217                         acomp->input1 = (float*)data;
 218                         break;
 219                 case ACOMP_A2:
 220                         acomp->sc = (float*)data;
 221                         break;
 222                 case ACOMP_A3:
 223                         acomp->output0 = (float*)data;
 224                         break;
 225                 case ACOMP_A4:
 226                         acomp->output1 = (float*)data;
 227                         break;
 228         default:
 229                 break;
 230         }
 231 }
 232
 233 // Force already-denormal float value to zero
 234 static inline float
 235 sanitize_denormal(float value) {
 236         if (!isnormal(value)) {
 237                 value = 0.f;
 238         }
 239         return value;
 240 }
 241
 242 static inline float
 243 from_dB(float gdb) {
 244         return (exp(gdb/20.f*log(10.f)));
 245 }
 246
 247 static inline float
 248 to_dB(float g) {
 249         return (20.f*log10(g));
 250 }
 251
 252 static void
 253 activate(LV2_Handle instance)
 254 {
 255         AComp* acomp = (AComp*)instance;
 256
 257         *(acomp->gainr) = 0.0f;
 258         *(acomp->outlevel) = -45.0f;
 259         acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
 260 }
 261
 262 static void
 263 run_mono(LV2_Handle instance, uint32_t n_samples)
 264 {
 265         AComp* acomp = (AComp*)instance;
 266
 267         const float* const input = acomp->input0;
 268         const float* const sc = acomp->sc;
 269         float* const output = acomp->output0;
 270
 271         float srate = acomp->srate;
 272         float width = (6.f * *(acomp->knee)) + 0.01;
 273         float cdb=0.f;
 274         float attack_coeff = exp(-1000.f/(*(acomp->attack) * srate));
 275         float release_coeff = exp(-1000.f/(*(acomp->release) * srate));
 276
 277         float max = 0.f;
 278         float lgaininp = 0.f;
 279         float Lgain = 1.f;
 280         float Lxg, Lxl, Lyg, Lyl, Ly1;
 281         int usesidechain = (*(acomp->sidechain) <= 0.f) ? 0 : 1;
 282         uint32_t i;
 283         float ingain;
 284         float in0;
 285         float sc0;
 286
 287         float ratio = *acomp->ratio;
 288         float thresdb = *acomp->thresdb;
 289         float makeup = *acomp->makeup;
 290         float makeup_target = from_dB(makeup);
 291         float makeup_gain = acomp->makeup_gain;
 292
 293         const float tau = acomp->tau;
 294
 295         if (*acomp->enable <= 0) {
 296                 ratio = 1.f;
 297                 thresdb = 0.f;
 298                 makeup = 0.f;
 299                 makeup_target = 1.f;
 300         }
 301
 302 #ifdef LV2_EXTENDED
 303         if (acomp->v_knee != *acomp->knee) {
 304                 acomp->v_knee = *acomp->knee;
 305                 acomp->need_expose = true;
 306         }
 307
 308         if (acomp->v_ratio != ratio) {
 309                 acomp->v_ratio = ratio;
 310                 acomp->need_expose = true;
 311         }
 312
 313         if (acomp->v_thresdb != thresdb) {
 314                 acomp->v_thresdb = thresdb;
 315                 acomp->need_expose = true;
 316         }
 317
 318         if (acomp->v_makeup != makeup) {
 319                 acomp->v_makeup = makeup;
 320                 acomp->need_expose = true;
 321         }
 322 #endif
 323
 324         float in_peak = 0;
 325         acomp->v_gainr = 0.0;
 326
 327         for (i = 0; i < n_samples; i++) {
 328                 in0 = input[i];
 329                 sc0 = sc[i];
 330                 ingain = usesidechain ? fabs(sc0) : fabs(in0);
 331                 in_peak = fmaxf (in_peak, ingain);
 332                 Lyg = 0.f;
 333                 Lxg = (ingain==0.f) ? -160.f : to_dB(ingain);
 334                 Lxg = sanitize_denormal(Lxg);
 335
 336
 337                 if (2.f*(Lxg-thresdb) < -width) {
 338                         Lyg = Lxg;
 339                 } else if (2.f*(Lxg-thresdb) > width) {
 340                         Lyg = thresdb + (Lxg-thresdb)/ratio;
 341                         Lyg = sanitize_denormal(Lyg);
 342                 } else {
 343                         Lyg = Lxg + (1.f/ratio-1.f)*(Lxg-thresdb+width/2.f)*(Lxg-thresdb+width/2.f)/(2.f*width);
 344                 }
 345
 346                 Lxl = Lxg - Lyg;
 347
 348                 acomp->old_y1 = sanitize_denormal(acomp->old_y1);
 349                 acomp->old_yl = sanitize_denormal(acomp->old_yl);
 350                 Ly1 = fmaxf(Lxl, release_coeff * acomp->old_y1+(1.f-release_coeff)*Lxl);
 351                 Lyl = attack_coeff * acomp->old_yl+(1.f-attack_coeff)*Ly1;
 352                 Ly1 = sanitize_denormal(Ly1);
 353                 Lyl = sanitize_denormal(Lyl);
 354
 355                 cdb = -Lyl;
 356                 Lgain = from_dB(cdb);
 357
 358                 *(acomp->gainr) = Lyl;
 359                 if (Lyl > acomp->v_gainr) {
 360                         acomp->v_gainr = Lyl;
 361                 }
 362
 363                 lgaininp = in0 * Lgain;
 364
 365                 makeup_gain += tau * (makeup_target - makeup_gain) + 1e-12;
 366                 output[i] = lgaininp * makeup_gain;
 367
 368                 max = (fabsf(output[i]) > max) ? fabsf(output[i]) : sanitize_denormal(max);
 369
 370                 // TODO re-use local variables on stack
 371                 // store values back to acomp at the end of the inner-loop
 372                 acomp->old_yl = Lyl;
 373                 acomp->old_y1 = Ly1;
 374                 acomp->old_yg = Lyg;
 375         }
 376
 377         *(acomp->outlevel) = (max < 0.0056f) ? -45.f : to_dB(max);
 378         acomp->makeup_gain = makeup_gain;
 379
 380 #ifdef LV2_EXTENDED
 381         const float old_v_lv1 = acomp->v_lv1;
 382         const float old_v_lvl = acomp->v_lvl;
 383         const float tot_rel_c = exp(-1000.f/(*(acomp->release) * srate) * n_samples);
 384         const float tot_atk_c = exp(-1000.f/(*(acomp->attack) * srate) * n_samples);
 385         acomp->v_lv1 = fmaxf (in_peak, tot_rel_c*old_v_lv1 + (1.f-tot_rel_c)*in_peak);
 386         acomp->v_lvl = tot_atk_c*old_v_lvl + (1.f-tot_atk_c)*acomp->v_lv1;
 387
 388         if (!isfinite_local (acomp->v_lvl)) {
 389                 acomp->v_lvl = 0.f;
 390         }
 391         const float v_lvl_in = (acomp->v_lvl < 0.001f) ? -60.f : to_dB(acomp->v_lvl);
 392         const float v_lvl_out = (max < 0.001f) ? -60.f : to_dB(max);
 393         if (fabsf (acomp->v_lvl_out - v_lvl_out) >= 1 || fabsf (acomp->v_lvl_in - v_lvl_in) >= 1) {
 394                 // >= 1dB difference
 395                 acomp->need_expose = true;
 396                 acomp->v_lvl_in = v_lvl_in;
 397                 acomp->v_lvl_out = v_lvl_out - to_dB(makeup_gain);
 398         }
 399         if (acomp->need_expose && acomp->queue_draw) {
 400                 acomp->need_expose = false;
 401                 acomp->queue_draw->queue_draw (acomp->queue_draw->handle);
 402         }
 403 #endif
 404 }
 405
 406 static void
 407 run_stereo(LV2_Handle instance, uint32_t n_samples)
 408 {
 409         AComp* acomp = (AComp*)instance;
 410
 411         const float* const input0 = acomp->input0;
 412         const float* const input1 = acomp->input1;
 413         const float* const sc = acomp->sc;
 414         float* const output0 = acomp->output0;
 415         float* const output1 = acomp->output1;
 416
 417         float srate = acomp->srate;
 418         float width = (6.f * *(acomp->knee)) + 0.01;
 419         float cdb=0.f;
 420         float attack_coeff = exp(-1000.f/(*(acomp->attack) * srate));
 421         float release_coeff = exp(-1000.f/(*(acomp->release) * srate));
 422
 423         float max = 0.f;
 424         float lgaininp = 0.f;
 425         float rgaininp = 0.f;
 426         float Lgain = 1.f;
 427         float Lxg, Lxl, Lyg, Lyl, Ly1;
 428         int usesidechain = (*(acomp->sidechain) <= 0.f) ? 0 : 1;
 429         uint32_t i;
 430         float ingain;
 431         float in0;
 432         float in1;
 433         float sc0;
 434         float maxabslr;
 435
 436         float ratio = *acomp->ratio;
 437         float thresdb = *acomp->thresdb;
 438         float makeup = *acomp->makeup;
 439         float makeup_target = from_dB(makeup);
 440         float makeup_gain = acomp->makeup_gain;
 441
 442         const float tau = acomp->tau;
 443
 444         if (*acomp->enable <= 0) {
 445                 ratio = 1.f;
 446                 thresdb = 0.f;
 447                 makeup = 0.f;
 448                 makeup_target = 1.f;
 449         }
 450
 451 #ifdef LV2_EXTENDED
 452         if (acomp->v_knee != *acomp->knee) {
 453                 acomp->v_knee = *acomp->knee;
 454                 acomp->need_expose = true;
 455         }
 456
 457         if (acomp->v_ratio != ratio) {
 458                 acomp->v_ratio = ratio;
 459                 acomp->need_expose = true;
 460         }
 461
 462         if (acomp->v_thresdb != thresdb) {
 463                 acomp->v_thresdb = thresdb;
 464                 acomp->need_expose = true;
 465         }
 466
 467         if (acomp->v_makeup != makeup) {
 468                 acomp->v_makeup = makeup;
 469                 acomp->need_expose = true;
 470         }
 471 #endif
 472
 473         float in_peak = 0;
 474         acomp->v_gainr = 0.0;
 475
 476         for (i = 0; i < n_samples; i++) {
 477                 in0 = input0[i];
 478                 in1 = input1[i];
 479                 sc0 = sc[i];
 480                 maxabslr = fmaxf(fabs(in0), fabs(in1));
 481                 ingain = usesidechain ? fabs(sc0) : maxabslr;
 482                 in_peak = fmaxf (in_peak, ingain);
 483                 Lyg = 0.f;
 484                 Lxg = (ingain==0.f) ? -160.f : to_dB(ingain);
 485                 Lxg = sanitize_denormal(Lxg);
 486
 487
 488                 if (2.f*(Lxg-thresdb) < -width) {
 489                         Lyg = Lxg;
 490                 } else if (2.f*(Lxg-thresdb) > width) {
 491                         Lyg = thresdb + (Lxg-thresdb)/ratio;
 492                         Lyg = sanitize_denormal(Lyg);
 493                 } else {
 494                         Lyg = Lxg + (1.f/ratio-1.f)*(Lxg-thresdb+width/2.f)*(Lxg-thresdb+width/2.f)/(2.f*width);
 495                 }
 496
 497                 Lxl = Lxg - Lyg;
 498
 499                 acomp->old_y1 = sanitize_denormal(acomp->old_y1);
 500                 acomp->old_yl = sanitize_denormal(acomp->old_yl);
 501                 Ly1 = fmaxf(Lxl, release_coeff * acomp->old_y1+(1.f-release_coeff)*Lxl);
 502                 Lyl = attack_coeff * acomp->old_yl+(1.f-attack_coeff)*Ly1;
 503                 Ly1 = sanitize_denormal(Ly1);
 504                 Lyl = sanitize_denormal(Lyl);
 505
 506                 cdb = -Lyl;
 507                 Lgain = from_dB(cdb);
 508
 509                 *(acomp->gainr) = Lyl;
 510                 if (Lyl > acomp->v_gainr) {
 511                         acomp->v_gainr = Lyl;
 512                 }
 513
 514                 lgaininp = in0 * Lgain;
 515                 rgaininp = in1 * Lgain;
 516
 517                 makeup_gain += tau * (makeup_target - makeup_gain) + 1e-12;
 518
 519                 output0[i] = lgaininp * makeup_gain;
 520                 output1[i] = rgaininp * makeup_gain;
 521
 522                 max = (fmaxf(fabs(output0[i]), fabs(output1[i])) > max) ? fmaxf(fabs(output0[i]), fabs(output1[i])) : sanitize_denormal(max);
 523
 524                 // TODO re-use local variables on stack
 525                 // store values back to acomp at the end of the inner-loop
 526                 acomp->old_yl = Lyl;
 527                 acomp->old_y1 = Ly1;
 528                 acomp->old_yg = Lyg;
 529         }
 530
 531         *(acomp->outlevel) = (max < 0.0056f) ? -45.f : to_dB(max);
 532         acomp->makeup_gain = makeup_gain;
 533
 534 #ifdef LV2_EXTENDED
 535         const float old_v_lv1 = acomp->v_lv1;
 536         const float old_v_lvl = acomp->v_lvl;
 537         const float tot_rel_c = exp(-1000.f/(*(acomp->release) * srate) * n_samples);
 538         const float tot_atk_c = exp(-1000.f/(*(acomp->attack) * srate) * n_samples);
 539         acomp->v_lv1 = fmaxf (in_peak, tot_rel_c*old_v_lv1 + (1.f-tot_rel_c)*in_peak);
 540         acomp->v_lvl = tot_atk_c*old_v_lvl + (1.f-tot_atk_c)*acomp->v_lv1;
 541         if (!isfinite_local (acomp->v_lvl)) {
 542                 acomp->v_lvl = 0.f;
 543         }
 544         const float v_lvl_in = (acomp->v_lvl < 0.001f) ? -60.f : to_dB(acomp->v_lvl);
 545         const float v_lvl_out = (max < 0.001f) ? -60.f : to_dB(max);
 546         if (fabsf (acomp->v_lvl_out - v_lvl_out) >= 1 || fabsf (acomp->v_lvl_in - v_lvl_in) >= 1) {
 547                 // >= 1dB difference
 548                 acomp->need_expose = true;
 549                 acomp->v_lvl_in = v_lvl_in;
 550                 acomp->v_lvl_out = v_lvl_out - to_dB(makeup_gain);
 551         }
 552         if (acomp->need_expose && acomp->queue_draw) {
 553                 acomp->need_expose = false;
 554                 acomp->queue_draw->queue_draw (acomp->queue_draw->handle);
 555         }
 556 #endif
 557 }
 558
 559 static void
 560 deactivate(LV2_Handle instance)
 561 {
 562         activate(instance);
 563 }
 564
 565 static void
 566 cleanup(LV2_Handle instance)
 567 {
 568 #ifdef LV2_EXTENDED
 569         AComp* acomp = (AComp*)instance;
 570         if (acomp->display) {
 571                 cairo_surface_destroy (acomp->display);
 572         }
 573 #endif
 574
 575         free(instance);
 576 }
 577
 578
 579 #ifndef MIN
 580 #define MIN(A,B) ((A) < (B)) ? (A) : (B)
 581 #endif
 582
 583 #ifdef LV2_EXTENDED
 584 static float
 585 comp_curve (AComp* self, float xg) {
 586         const float knee = self->v_knee;
 587         const float ratio = self->v_ratio;
 588         const float thresdb = self->v_thresdb;
 589         const float makeup = self->v_makeup;
 590
 591         const float width = 6.f * knee + 0.01f;
 592         float yg = 0.f;
 593
 594         if (2.f * (xg - thresdb) < -width) {
 595                 yg = xg;
 596         } else if (2.f * (xg - thresdb) > width) {
 597                 yg = thresdb + (xg - thresdb) / ratio;
 598         } else {
 599                 yg = xg + (1.f / ratio - 1.f ) * (xg - thresdb + width / 2.f) * (xg - thresdb + width / 2.f) / (2.f * width);
 600         }
 601
 602         yg += makeup;
 603
 604         return yg;
 605 }
 606
 607 static LV2_Inline_Display_Image_Surface *
 608 render_inline (LV2_Handle instance, uint32_t w, uint32_t max_h)
 609 {
 610         AComp* self = (AComp*)instance;
 611         uint32_t h = MIN (w, max_h);
 612
 613         const float makeup_thres = self->v_thresdb + self->v_makeup;
 614
 615         if (!self->display || self->w != w || self->h != h) {
 616                 if (self->display) cairo_surface_destroy(self->display);
 617                 self->display = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, w, h);
 618                 self->w = w;
 619                 self->h = h;
 620         }
 621
 622         cairo_t* cr = cairo_create (self->display);
 623
 624         // clear background
 625         cairo_rectangle (cr, 0, 0, w, h);
 626         cairo_set_source_rgba (cr, .2, .2, .2, 1.0);
 627         cairo_fill (cr);
 628
 629         cairo_set_line_width(cr, 1.0);
 630
 631         // draw grid 10dB steps
 632         const double dash1[] = {1, 2};
 633         const double dash2[] = {1, 3};
 634         cairo_save (cr);
 635         cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND);
 636         cairo_set_dash(cr, dash2, 2, 2);
 637         cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 638
 639         for (uint32_t d = 1; d < 7; ++d) {
 640                 const float x = -.5 + floorf (w * (d * 10.f / 70.f));
 641                 const float y = -.5 + floorf (h * (d * 10.f / 70.f));
 642
 643                 cairo_move_to (cr, x, 0);
 644                 cairo_line_to (cr, x, h);
 645                 cairo_stroke (cr);
 646
 647                 cairo_move_to (cr, 0, y);
 648                 cairo_line_to (cr, w, y);
 649                 cairo_stroke (cr);
 650         }
 651         cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 1.0);
 652         cairo_set_dash(cr, dash1, 2, 2);
 653         if (self->v_thresdb < 0) {
 654                 const float y = -.5 + floorf (h * ((makeup_thres - 10.f) / -70.f));
 655                 cairo_move_to (cr, 0, y);
 656                 cairo_line_to (cr, w, y);
 657                 cairo_stroke (cr);
 658         }
 659         // diagonal unity
 660         cairo_move_to (cr, 0, h);
 661         cairo_line_to (cr, w, 0);
 662         cairo_stroke (cr);
 663         cairo_restore (cr);
 664
 665         { // 0, 0
 666                 cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 667                 const float x = -.5 + floorf (w * (60.f / 70.f));
 668                 const float y = -.5 + floorf (h * (10.f / 70.f));
 669                 cairo_move_to (cr, x, 0);
 670                 cairo_line_to (cr, x, h);
 671                 cairo_stroke (cr);
 672                 cairo_move_to (cr, 0, y);
 673                 cairo_line_to (cr, w, y);
 674                 cairo_stroke (cr);
 675         }
 676
 677         { // GR
 678                 const float x = -.5 + floorf (w * (62.5f / 70.f));
 679                 const float y = -.5 + floorf (h * (10.0f / 70.f));
 680                 const float wd = floorf (w * (5.f / 70.f));
 681                 const float ht = floorf (h * (55.f / 70.f));
 682                 cairo_rectangle (cr, x, y, wd, ht);
 683                 cairo_fill (cr);
 684
 685                 const float h_gr = fminf (ht, floorf (h * self->v_gainr / 70.f));
 686                 cairo_set_source_rgba (cr, 0.95, 0.0, 0.0, 1.0);
 687                 cairo_rectangle (cr, x, y, wd, h_gr);
 688                 cairo_fill (cr);
 689                 cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 690                 cairo_rectangle (cr, x, y, wd, ht);
 691                 cairo_set_source_rgba (cr, 0.75, 0.75, 0.75, 1.0);
 692                 cairo_stroke (cr);
 693         }
 694
 695         // draw curve
 696         cairo_set_source_rgba (cr, .8, .8, .8, 1.0);
 697         cairo_move_to (cr, 0, h);
 698
 699         for (uint32_t x = 0; x < w; ++x) {
 700                 // plot -60..+10  dB
 701                 const float x_db = 70.f * (-1.f + x / (float)w) + 10.f;
 702                 const float y_db = comp_curve (self, x_db) - 10.f;
 703                 const float y = h * (y_db / -70.f);
 704                 cairo_line_to (cr, x, y);
 705         }
 706         cairo_stroke_preserve (cr);
 707
 708         cairo_line_to (cr, w, h);
 709         cairo_close_path (cr);
 710         cairo_clip (cr);
 711
 712         // draw signal level & reduction/gradient
 713         const float top = comp_curve (self, 0) - 10.f;
 714         cairo_pattern_t* pat = cairo_pattern_create_linear (0.0, 0.0, 0.0, h);
 715         if (top > makeup_thres - 10.f) {
 716                 cairo_pattern_add_color_stop_rgba (pat, 0.0, 0.8, 0.1, 0.1, 0.5);
 717                 cairo_pattern_add_color_stop_rgba (pat, top / -70.f, 0.8, 0.1, 0.1, 0.5);
 718         }
 719         if (self->v_knee > 0) {
 720                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres -10.f) / -70.f), 0.7, 0.7, 0.2, 0.5);
 721                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres - self->v_knee - 10.f) / -70.f), 0.5, 0.5, 0.5, 0.5);
 722         } else {
 723                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres - 10.f)/ -70.f), 0.7, 0.7, 0.2, 0.5);
 724                 cairo_pattern_add_color_stop_rgba (pat, ((makeup_thres - 10.01f) / -70.f), 0.5, 0.5, 0.5, 0.5);
 725         }
 726         cairo_pattern_add_color_stop_rgba (pat, 1.0, 0.5, 0.5, 0.5, 0.5);
 727
 728         // maybe cut off at x-position?
 729         const float x = w * (self->v_lvl_in + 60) / 70.f;
 730         const float y = x + h*self->v_makeup;
 731         cairo_rectangle (cr, 0, h - y, x, y);
 732         if (self->v_ratio > 1.0) {
 733                 cairo_set_source (cr, pat);
 734         } else {
 735                 cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 736         }
 737         cairo_fill (cr);
 738
 739         cairo_pattern_destroy (pat); // TODO cache pattern
 740
 741
 742         // create RGBA surface
 743         cairo_destroy (cr);
 744         cairo_surface_flush (self->display);
 745         self->surf.width = cairo_image_surface_get_width (self->display);
 746         self->surf.height = cairo_image_surface_get_height (self->display);
 747         self->surf.stride = cairo_image_surface_get_stride (self->display);
 748         self->surf.data = cairo_image_surface_get_data  (self->display);
 749
 750         return &self->surf;
 751 }
 752 #endif
 753
 754 static const void*
 755 extension_data(const char* uri)
 756 {
 757 #ifdef LV2_EXTENDED
 758         static const LV2_Inline_Display_Interface display  = { render_inline };
 759         if (!strcmp(uri, LV2_INLINEDISPLAY__interface)) {
 760                 return &display;
 761         }
 762 #endif
 763         return NULL;
 764 }
 765
 766 static const LV2_Descriptor descriptor_mono = {
 767         ACOMP_URI,
 768         instantiate,
 769         connect_mono,
 770         activate,
 771         run_mono,
 772         deactivate,
 773         cleanup,
 774         extension_data
 775 };
 776
 777 static const LV2_Descriptor descriptor_stereo = {
 778         ACOMP_STEREO_URI,
 779         instantiate,
 780         connect_stereo,
 781         activate,
 782         run_stereo,
 783         deactivate,
 784         cleanup,
 785         extension_data
 786 };
 787
 788 LV2_SYMBOL_EXPORT
 789 const LV2_Descriptor*
 790 lv2_descriptor(uint32_t index)
 791 {
 792         switch (index) {
 793         case 0:
 794                 return &descriptor_mono;
 795         case 1:
 796                 return &descriptor_stereo;
 797         default:
 798                 return NULL;
 799         }
 800 }