git.sesse.net Git - nageru/blob - midi_mapper.cpp

   1 #include "midi_mapper.h"
   2
   3 #include "audio_mixer.h"
   4 #include "midi_mapping.pb.h"
   5
   6 #include <alsa/asoundlib.h>
   7 #include <google/protobuf/text_format.h>
   8 #include <google/protobuf/io/zero_copy_stream.h>
   9 #include <google/protobuf/io/zero_copy_stream_impl.h>
  10 #include <fcntl.h>
  11 #include <sys/eventfd.h>
  12
  13 #include <functional>
  14 #include <thread>
  15
  16 using namespace google::protobuf;
  17 using namespace std;
  18 using namespace std::placeholders;
  19
  20 namespace {
  21
  22 double map_controller_to_float(int val)
  23 {
  24         // Slightly hackish mapping so that we can represent exactly 0.0, 0.5 and 1.0.
  25         if (val <= 0) {
  26                 return 0.0;
  27         } else if (val >= 127) {
  28                 return 1.0;
  29         } else {
  30                 return (val + 0.5) / 127.0;
  31         }
  32 }
  33
  34 }  // namespace
  35
  36 MIDIMapper::MIDIMapper(ControllerReceiver *receiver)
  37         : receiver(receiver), mapping_proto(new MIDIMappingProto)
  38 {
  39         should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
  40         assert(should_quit_fd != -1);
  41         refresh_highlights();
  42 }
  43
  44 MIDIMapper::~MIDIMapper()
  45 {
  46         should_quit = true;
  47         const uint64_t one = 1;
  48         write(should_quit_fd, &one, sizeof(one));
  49         midi_thread.join();
  50         close(should_quit_fd);
  51 }
  52
  53 bool load_midi_mapping_from_file(const string &filename, MIDIMappingProto *new_mapping)
  54 {
  55         // Read and parse the protobuf from disk.
  56         int fd = open(filename.c_str(), O_RDONLY);
  57         if (fd == -1) {
  58                 perror(filename.c_str());
  59                 return false;
  60         }
  61         io::FileInputStream input(fd);  // Takes ownership of fd.
  62         if (!TextFormat::Parse(&input, new_mapping)) {
  63                 input.Close();
  64                 return false;
  65         }
  66         input.Close();
  67         return true;
  68 }
  69
  70 bool save_midi_mapping_to_file(const MIDIMappingProto &mapping_proto, const string &filename)
  71 {
  72         // Save to disk. We use the text format because it's friendlier
  73         // for a user to look at and edit.
  74         int fd = open(filename.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
  75         if (fd == -1) {
  76                 perror(filename.c_str());
  77                 return false;
  78         }
  79         io::FileOutputStream output(fd);  // Takes ownership of fd.
  80         if (!TextFormat::Print(mapping_proto, &output)) {
  81                 // TODO: Don't overwrite the old file (if any) on error.
  82                 output.Close();
  83                 return false;
  84         }
  85
  86         output.Close();
  87         return true;
  88 }
  89
  90 void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
  91 {
  92         lock_guard<mutex> lock(mu);
  93         if (mapping_proto) {
  94                 mapping_proto->CopyFrom(new_mapping);
  95         } else {
  96                 mapping_proto.reset(new MIDIMappingProto(new_mapping));
  97         }
  98
  99         num_controller_banks = min(max(mapping_proto->num_controller_banks(), 1), 5);
 100         current_controller_bank = 0;
 101
 102         receiver->clear_all_highlights();
 103         update_highlights();
 104 }
 105
 106 void MIDIMapper::start_thread()
 107 {
 108         midi_thread = thread(&MIDIMapper::thread_func, this);
 109 }
 110
 111 const MIDIMappingProto &MIDIMapper::get_current_mapping() const
 112 {
 113         lock_guard<mutex> lock(mu);
 114         return *mapping_proto;
 115 }
 116
 117 ControllerReceiver *MIDIMapper::set_receiver(ControllerReceiver *new_receiver)
 118 {
 119         lock_guard<mutex> lock(mu);
 120         swap(receiver, new_receiver);
 121         return new_receiver;  // Now old receiver.
 122 }
 123
 124 #define RETURN_ON_ERROR(msg, expr) do {                            \
 125         int err = (expr);                                          \
 126         if (err < 0) {                                             \
 127                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
 128                 return;                                            \
 129         }                                                          \
 130 } while (false)
 131
 132 #define WARN_ON_ERROR(msg, expr) do {                              \
 133         int err = (expr);                                          \
 134         if (err < 0) {                                             \
 135                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
 136         }                                                          \
 137 } while (false)
 138
 139
 140 void MIDIMapper::thread_func()
 141 {
 142         snd_seq_t *seq;
 143         int err;
 144
 145         RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
 146         RETURN_ON_ERROR("snd_seq_nonblock", snd_seq_nonblock(seq, 1));
 147         RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
 148         RETURN_ON_ERROR("snd_seq_create_simple_port",
 149                 snd_seq_create_simple_port(seq, "nageru",
 150                         SND_SEQ_PORT_CAP_READ |
 151                                 SND_SEQ_PORT_CAP_SUBS_READ |
 152                                 SND_SEQ_PORT_CAP_WRITE |
 153                                 SND_SEQ_PORT_CAP_SUBS_WRITE,
 154                         SND_SEQ_PORT_TYPE_MIDI_GENERIC |
 155                                 SND_SEQ_PORT_TYPE_APPLICATION));
 156
 157         int queue_id = snd_seq_alloc_queue(seq);
 158         RETURN_ON_ERROR("snd_seq_create_queue", queue_id);
 159         RETURN_ON_ERROR("snd_seq_start_queue", snd_seq_start_queue(seq, queue_id, nullptr));
 160
 161         // The sequencer object is now ready to be used from other threads.
 162         {
 163                 lock_guard<mutex> lock(mu);
 164                 alsa_seq = seq;
 165                 alsa_queue_id = queue_id;
 166         }
 167
 168         // Listen to the announce port (0:1), which will tell us about new ports.
 169         RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, /*client=*/0, /*port=*/1));
 170
 171         // Now go through all ports and subscribe to them.
 172         snd_seq_client_info_t *cinfo;
 173         snd_seq_client_info_alloca(&cinfo);
 174
 175         snd_seq_client_info_set_client(cinfo, -1);
 176         while (snd_seq_query_next_client(seq, cinfo) >= 0) {
 177                 int client = snd_seq_client_info_get_client(cinfo);
 178
 179                 snd_seq_port_info_t *pinfo;
 180                 snd_seq_port_info_alloca(&pinfo);
 181
 182                 snd_seq_port_info_set_client(pinfo, client);
 183                 snd_seq_port_info_set_port(pinfo, -1);
 184                 while (snd_seq_query_next_port(seq, pinfo) >= 0) {
 185                         constexpr int mask = SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ;
 186                         if ((snd_seq_port_info_get_capability(pinfo) & mask) == mask) {
 187                                 lock_guard<mutex> lock(mu);
 188                                 subscribe_to_port_lock_held(seq, *snd_seq_port_info_get_addr(pinfo));
 189                         }
 190                 }
 191         }
 192
 193         int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
 194         unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
 195
 196         while (!should_quit) {
 197                 snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
 198                 fds[num_alsa_fds].fd = should_quit_fd;
 199                 fds[num_alsa_fds].events = POLLIN;
 200                 fds[num_alsa_fds].revents = 0;
 201
 202                 err = poll(fds.get(), num_alsa_fds + 1, -1);
 203                 if (err == 0 || (err == -1 && errno == EINTR)) {
 204                         continue;
 205                 }
 206                 if (err == -1) {
 207                         perror("poll");
 208                         break;
 209                 }
 210                 if (fds[num_alsa_fds].revents) {
 211                         // Activity on should_quit_fd.
 212                         break;
 213                 }
 214
 215                 // Seemingly we can get multiple events in a single poll,
 216                 // and if we don't handle them all, poll will _not_ alert us!
 217                 while (!should_quit) {
 218                         snd_seq_event_t *event;
 219                         err = snd_seq_event_input(seq, &event);
 220                         if (err < 0) {
 221                                 if (err == -EINTR) continue;
 222                                 if (err == -EAGAIN) break;
 223                                 fprintf(stderr, "snd_seq_event_input: %s\n", snd_strerror(err));
 224                                 return;
 225                         }
 226                         if (event) {
 227                                 handle_event(seq, event);
 228                         }
 229                 }
 230         }
 231 }
 232
 233 void MIDIMapper::handle_event(snd_seq_t *seq, snd_seq_event_t *event)
 234 {
 235         if (event->source.client == snd_seq_client_id(seq)) {
 236                 // Ignore events we sent out ourselves.
 237                 return;
 238         }
 239
 240         lock_guard<mutex> lock(mu);
 241         switch (event->type) {
 242         case SND_SEQ_EVENT_CONTROLLER: {
 243                 printf("Controller %d changed to %d\n", event->data.control.param, event->data.control.value);
 244
 245                 const int controller = event->data.control.param;
 246                 const float value = map_controller_to_float(event->data.control.value);
 247
 248                 receiver->controller_changed(controller);
 249
 250                 // Global controllers.
 251                 match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
 252                         value, bind(&ControllerReceiver::set_locut, receiver, _2));
 253                 match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
 254                         value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
 255                 match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
 256                         value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
 257
 258                 // Bus controllers.
 259                 match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
 260                         value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
 261                 match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
 262                         value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
 263                 match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
 264                         value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
 265                 match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
 266                         value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
 267                 match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
 268                         value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
 269                 match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
 270                         value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
 271                 break;
 272         }
 273         case SND_SEQ_EVENT_NOTEON: {
 274                 const int note = event->data.note.note;
 275
 276                 receiver->note_on(note);
 277
 278                 printf("Note: %d\n", note);
 279
 280                 for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 281                         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 282                         if (bus_mapping.has_prev_bank() &&
 283                             bus_mapping.prev_bank().note_number() == note) {
 284                                 current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
 285                                 update_highlights();
 286                                 update_lights_lock_held();
 287                         }
 288                         if (bus_mapping.has_next_bank() &&
 289                             bus_mapping.next_bank().note_number() == note) {
 290                                 current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
 291                                 update_highlights();
 292                                 update_lights_lock_held();
 293                         }
 294                         if (bus_mapping.has_select_bank_1() &&
 295                             bus_mapping.select_bank_1().note_number() == note) {
 296                                 current_controller_bank = 0;
 297                                 update_highlights();
 298                                 update_lights_lock_held();
 299                         }
 300                         if (bus_mapping.has_select_bank_2() &&
 301                             bus_mapping.select_bank_2().note_number() == note &&
 302                             num_controller_banks >= 2) {
 303                                 current_controller_bank = 1;
 304                                 update_highlights();
 305                                 update_lights_lock_held();
 306                         }
 307                         if (bus_mapping.has_select_bank_3() &&
 308                             bus_mapping.select_bank_3().note_number() == note &&
 309                             num_controller_banks >= 3) {
 310                                 current_controller_bank = 2;
 311                                 update_highlights();
 312                                 update_lights_lock_held();
 313                         }
 314                         if (bus_mapping.has_select_bank_4() &&
 315                             bus_mapping.select_bank_4().note_number() == note &&
 316                             num_controller_banks >= 4) {
 317                                 current_controller_bank = 3;
 318                                 update_highlights();
 319                                 update_lights_lock_held();
 320                         }
 321                         if (bus_mapping.has_select_bank_5() &&
 322                             bus_mapping.select_bank_5().note_number() == note &&
 323                             num_controller_banks >= 5) {
 324                                 current_controller_bank = 4;
 325                                 update_highlights();
 326                                 update_lights_lock_held();
 327                         }
 328                 }
 329
 330                 match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
 331                         bind(&ControllerReceiver::toggle_locut, receiver, _1));
 332                 match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
 333                         bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
 334                 match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
 335                         bind(&ControllerReceiver::toggle_compressor, receiver, _1));
 336                 match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 337                         bind(&ControllerReceiver::clear_peak, receiver, _1));
 338                 match_button(note, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 339                         bind(&ControllerReceiver::toggle_mute, receiver, _1));
 340                 match_button(note, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber,
 341                         bind(&ControllerReceiver::toggle_limiter, receiver));
 342                 match_button(note, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber,
 343                         bind(&ControllerReceiver::toggle_auto_makeup_gain, receiver));
 344         }
 345         case SND_SEQ_EVENT_PORT_START:
 346                 subscribe_to_port_lock_held(seq, event->data.addr);
 347                 break;
 348         case SND_SEQ_EVENT_PORT_EXIT:
 349                 printf("MIDI port %d:%d went away.\n", event->data.addr.client, event->data.addr.port);
 350                 break;
 351         case SND_SEQ_EVENT_PORT_SUBSCRIBED:
 352                 if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
 353                     event->data.connect.sender.client != snd_seq_client_id(seq) &&
 354                     event->data.connect.dest.client == snd_seq_client_id(seq)) {
 355                         ++num_subscribed_ports;
 356                         update_highlights();
 357                 }
 358                 break;
 359         case SND_SEQ_EVENT_PORT_UNSUBSCRIBED:
 360                 if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
 361                     event->data.connect.sender.client != snd_seq_client_id(seq) &&
 362                     event->data.connect.dest.client == snd_seq_client_id(seq)) {
 363                         --num_subscribed_ports;
 364                         update_highlights();
 365                 }
 366                 break;
 367         case SND_SEQ_EVENT_NOTEOFF:
 368         case SND_SEQ_EVENT_CLIENT_START:
 369         case SND_SEQ_EVENT_CLIENT_EXIT:
 370         case SND_SEQ_EVENT_CLIENT_CHANGE:
 371         case SND_SEQ_EVENT_PORT_CHANGE:
 372                 break;
 373         default:
 374                 printf("Ignoring MIDI event of unknown type %d.\n", event->type);
 375         }
 376 }
 377
 378 void MIDIMapper::subscribe_to_port_lock_held(snd_seq_t *seq, const snd_seq_addr_t &addr)
 379 {
 380         // Client 0 is basically the system; ignore it.
 381         if (addr.client == 0) {
 382                 return;
 383         }
 384
 385         int err = snd_seq_connect_from(seq, 0, addr.client, addr.port);
 386         if (err < 0) {
 387                 // Just print out a warning (i.e., don't die); it could
 388                 // very well just be e.g. another application.
 389                 printf("Couldn't subscribe to MIDI port %d:%d (%s).\n",
 390                         addr.client, addr.port, snd_strerror(err));
 391         } else {
 392                 printf("Subscribed to MIDI port %d:%d.\n", addr.client, addr.port);
 393         }
 394
 395         // For sending data back.
 396         err = snd_seq_connect_to(seq, 0, addr.client, addr.port);
 397         if (err < 0) {
 398                 printf("Couldn't subscribe MIDI port %d:%d (%s) to us.\n",
 399                         addr.client, addr.port, snd_strerror(err));
 400         } else {
 401                 printf("Subscribed MIDI port %d:%d to us.\n", addr.client, addr.port);
 402         }
 403
 404         current_light_status.clear();  // The current state of the device is unknown.
 405         update_lights_lock_held();
 406 }
 407
 408 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
 409 {
 410         if (bank_mismatch(bank_field_number)) {
 411                 return;
 412         }
 413
 414         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 415                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 416
 417                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 418                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 419                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 420                         continue;
 421                 }
 422                 const MIDIControllerProto &controller_proto =
 423                         static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 424                 if (controller_proto.controller_number() == controller) {
 425                         func(bus_idx, value);
 426                 }
 427         }
 428 }
 429
 430 void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
 431 {
 432         if (bank_mismatch(bank_field_number)) {
 433                 return;
 434         }
 435
 436         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 437                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 438
 439                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 440                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 441                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 442                         continue;
 443                 }
 444                 const MIDIButtonProto &button_proto =
 445                         static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 446                 if (button_proto.note_number() == note) {
 447                         func(bus_idx);
 448                 }
 449         }
 450 }
 451
 452 bool MIDIMapper::has_active_controller(unsigned bus_idx, int field_number, int bank_field_number)
 453 {
 454         if (bank_mismatch(bank_field_number)) {
 455                 return false;
 456         }
 457
 458         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 459         const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 460         const Reflection *bus_reflection = bus_mapping.GetReflection();
 461         return bus_reflection->HasField(bus_mapping, descriptor);
 462 }
 463
 464 bool MIDIMapper::bank_mismatch(int bank_field_number)
 465 {
 466         const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
 467         const Reflection *reflection = mapping_proto->GetReflection();
 468         return (reflection->HasField(*mapping_proto, bank_descriptor) &&
 469                 reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
 470 }
 471
 472 void MIDIMapper::refresh_highlights()
 473 {
 474         receiver->clear_all_highlights();
 475         update_highlights();
 476 }
 477
 478 void MIDIMapper::refresh_lights()
 479 {
 480         lock_guard<mutex> lock(mu);
 481         update_lights_lock_held();
 482 }
 483
 484 void MIDIMapper::update_highlights()
 485 {
 486         if (num_subscribed_ports.load() == 0) {
 487                 receiver->clear_all_highlights();
 488                 return;
 489         }
 490
 491         // Global controllers.
 492         bool highlight_locut = false;
 493         bool highlight_limiter_threshold = false;
 494         bool highlight_makeup_gain = false;
 495         bool highlight_toggle_limiter = false;
 496         bool highlight_toggle_auto_makeup_gain = false;
 497         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 498                 if (has_active_controller(
 499                         bus_idx, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber)) {
 500                         highlight_locut = true;
 501                 }
 502                 if (has_active_controller(
 503                         bus_idx, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber)) {
 504                         highlight_limiter_threshold = true;
 505                 }
 506                 if (has_active_controller(
 507                         bus_idx, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber)) {
 508                         highlight_makeup_gain = true;
 509                 }
 510                 if (has_active_controller(
 511                         bus_idx, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber)) {
 512                         highlight_toggle_limiter = true;
 513                 }
 514                 if (has_active_controller(
 515                         bus_idx, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber)) {
 516                         highlight_toggle_auto_makeup_gain = true;
 517                 }
 518         }
 519         receiver->highlight_locut(highlight_locut);
 520         receiver->highlight_limiter_threshold(highlight_limiter_threshold);
 521         receiver->highlight_makeup_gain(highlight_makeup_gain);
 522         receiver->highlight_toggle_limiter(highlight_toggle_limiter);
 523         receiver->highlight_toggle_auto_makeup_gain(highlight_toggle_auto_makeup_gain);
 524
 525         // Per-bus controllers.
 526         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 527                 receiver->highlight_treble(bus_idx, has_active_controller(
 528                         bus_idx, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber));
 529                 receiver->highlight_mid(bus_idx, has_active_controller(
 530                         bus_idx, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber));
 531                 receiver->highlight_bass(bus_idx, has_active_controller(
 532                         bus_idx, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber));
 533                 receiver->highlight_gain(bus_idx, has_active_controller(
 534                         bus_idx, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber));
 535                 receiver->highlight_compressor_threshold(bus_idx, has_active_controller(
 536                         bus_idx, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber));
 537                 receiver->highlight_fader(bus_idx, has_active_controller(
 538                         bus_idx, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber));
 539                 receiver->highlight_mute(bus_idx, has_active_controller(
 540                         bus_idx, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kToggleMuteBankFieldNumber));
 541                 receiver->highlight_toggle_locut(bus_idx, has_active_controller(
 542                         bus_idx, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber));
 543                 receiver->highlight_toggle_auto_gain_staging(bus_idx, has_active_controller(
 544                         bus_idx, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber));
 545                 receiver->highlight_toggle_compressor(bus_idx, has_active_controller(
 546                         bus_idx, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber));
 547         }
 548 }
 549
 550 void MIDIMapper::update_lights_lock_held()
 551 {
 552         if (alsa_seq == nullptr || global_audio_mixer == nullptr) {
 553                 return;
 554         }
 555
 556         set<unsigned> active_lights;  // Desired state.
 557         if (current_controller_bank == 0) {
 558                 activate_lights_all_buses(MIDIMappingBusProto::kBank1IsSelectedFieldNumber, &active_lights);
 559         }
 560         if (current_controller_bank == 1) {
 561                 activate_lights_all_buses(MIDIMappingBusProto::kBank2IsSelectedFieldNumber, &active_lights);
 562         }
 563         if (current_controller_bank == 2) {
 564                 activate_lights_all_buses(MIDIMappingBusProto::kBank3IsSelectedFieldNumber, &active_lights);
 565         }
 566         if (current_controller_bank == 3) {
 567                 activate_lights_all_buses(MIDIMappingBusProto::kBank4IsSelectedFieldNumber, &active_lights);
 568         }
 569         if (current_controller_bank == 4) {
 570                 activate_lights_all_buses(MIDIMappingBusProto::kBank5IsSelectedFieldNumber, &active_lights);
 571         }
 572         if (global_audio_mixer->get_limiter_enabled()) {
 573                 activate_lights_all_buses(MIDIMappingBusProto::kLimiterIsOnFieldNumber, &active_lights);
 574         }
 575         if (global_audio_mixer->get_final_makeup_gain_auto()) {
 576                 activate_lights_all_buses(MIDIMappingBusProto::kAutoMakeupGainIsOnFieldNumber, &active_lights);
 577         }
 578         unsigned num_buses = min<unsigned>(global_audio_mixer->num_buses(), mapping_proto->bus_mapping_size());
 579         for (unsigned bus_idx = 0; bus_idx < num_buses; ++bus_idx) {
 580                 if (global_audio_mixer->get_mute(bus_idx)) {
 581                         activate_lights(bus_idx, MIDIMappingBusProto::kIsMutedFieldNumber, &active_lights);
 582                 }
 583                 if (global_audio_mixer->get_locut_enabled(bus_idx)) {
 584                         activate_lights(bus_idx, MIDIMappingBusProto::kLocutIsOnFieldNumber, &active_lights);
 585                 }
 586                 if (global_audio_mixer->get_gain_staging_auto(bus_idx)) {
 587                         activate_lights(bus_idx, MIDIMappingBusProto::kAutoGainStagingIsOnFieldNumber, &active_lights);
 588                 }
 589                 if (global_audio_mixer->get_compressor_enabled(bus_idx)) {
 590                         activate_lights(bus_idx, MIDIMappingBusProto::kCompressorIsOnFieldNumber, &active_lights);
 591                 }
 592                 if (has_peaked[bus_idx]) {
 593                         activate_lights(bus_idx, MIDIMappingBusProto::kHasPeakedFieldNumber, &active_lights);
 594                 }
 595         }
 596
 597         unsigned num_events = 0;
 598         for (unsigned note_num = 1; note_num <= 127; ++note_num) {
 599                 bool active = active_lights.count(note_num);
 600                 if (current_light_status.count(note_num) &&
 601                     current_light_status[note_num] == active) {
 602                         // Already known to be in the desired state.
 603                         continue;
 604                 }
 605
 606                 snd_seq_event_t ev;
 607                 snd_seq_ev_clear(&ev);
 608
 609                 // Some devices drop events if we throw them onto them
 610                 // too quickly. Add a 1 ms delay for each.
 611                 snd_seq_real_time_t tm{0, num_events++ * 1000000};
 612                 snd_seq_ev_schedule_real(&ev, alsa_queue_id, true, &tm);
 613                 snd_seq_ev_set_source(&ev, 0);
 614                 snd_seq_ev_set_subs(&ev);
 615
 616                 // For some reason, not all devices respond to note off.
 617                 // Use note-on with velocity of 0 (which is equivalent) instead.
 618                 snd_seq_ev_set_noteon(&ev, /*channel=*/0, note_num, active ? 127 : 0);
 619                 WARN_ON_ERROR("snd_seq_event_output", snd_seq_event_output(alsa_seq, &ev));
 620                 current_light_status[note_num] = active;
 621         }
 622         WARN_ON_ERROR("snd_seq_drain_output", snd_seq_drain_output(alsa_seq));
 623 }
 624
 625 void MIDIMapper::activate_lights(unsigned bus_idx, int field_number, set<unsigned> *active_lights)
 626 {
 627         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 628
 629         const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 630         const Reflection *bus_reflection = bus_mapping.GetReflection();
 631         if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 632                 return;
 633         }
 634         const MIDILightProto &light_proto =
 635                 static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 636         active_lights->insert(light_proto.note_number());
 637 }
 638
 639 void MIDIMapper::activate_lights_all_buses(int field_number, set<unsigned> *active_lights)
 640 {
 641         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 642                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 643
 644                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 645                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 646                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 647                         continue;
 648                 }
 649                 const MIDILightProto &light_proto =
 650                         static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 651                 active_lights->insert(light_proto.note_number());
 652         }
 653 }