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

   1 #include "midi_mapper.h"
   2
   3 #include <alsa/asoundlib.h>
   4 #include <assert.h>
   5 #include <errno.h>
   6 #include <fcntl.h>
   7 #include <google/protobuf/descriptor.h>
   8 #include <google/protobuf/io/zero_copy_stream_impl.h>
   9 #include <google/protobuf/message.h>
  10 #include <google/protobuf/text_format.h>
  11 #include <pthread.h>
  12 #include <poll.h>
  13 #include <stdint.h>
  14 #include <stdio.h>
  15 #include <sys/eventfd.h>
  16 #include <unistd.h>
  17 #include <algorithm>
  18 #include <functional>
  19 #include <thread>
  20
  21 #include "audio_mixer.h"
  22 #include "midi_mapping.pb.h"
  23
  24 using namespace google::protobuf;
  25 using namespace std;
  26 using namespace std::placeholders;
  27
  28 namespace {
  29
  30 double map_controller_to_float(int val)
  31 {
  32         // Slightly hackish mapping so that we can represent exactly 0.0, 0.5 and 1.0.
  33         if (val <= 0) {
  34                 return 0.0;
  35         } else if (val >= 127) {
  36                 return 1.0;
  37         } else {
  38                 return (val + 0.5) / 127.0;
  39         }
  40 }
  41
  42 }  // namespace
  43
  44 MIDIMapper::MIDIMapper(ControllerReceiver *receiver)
  45         : receiver(receiver), mapping_proto(new MIDIMappingProto)
  46 {
  47         should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
  48         assert(should_quit_fd != -1);
  49 }
  50
  51 MIDIMapper::~MIDIMapper()
  52 {
  53         should_quit = true;
  54         const uint64_t one = 1;
  55         if (write(should_quit_fd, &one, sizeof(one)) != sizeof(one)) {
  56                 perror("write(should_quit_fd)");
  57                 exit(1);
  58         }
  59         midi_thread.join();
  60         close(should_quit_fd);
  61 }
  62
  63 bool load_midi_mapping_from_file(const string &filename, MIDIMappingProto *new_mapping)
  64 {
  65         // Read and parse the protobuf from disk.
  66         int fd = open(filename.c_str(), O_RDONLY);
  67         if (fd == -1) {
  68                 perror(filename.c_str());
  69                 return false;
  70         }
  71         io::FileInputStream input(fd);  // Takes ownership of fd.
  72         if (!TextFormat::Parse(&input, new_mapping)) {
  73                 input.Close();
  74                 return false;
  75         }
  76         input.Close();
  77         return true;
  78 }
  79
  80 bool save_midi_mapping_to_file(const MIDIMappingProto &mapping_proto, const string &filename)
  81 {
  82         // Save to disk. We use the text format because it's friendlier
  83         // for a user to look at and edit.
  84         int fd = open(filename.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
  85         if (fd == -1) {
  86                 perror(filename.c_str());
  87                 return false;
  88         }
  89         io::FileOutputStream output(fd);  // Takes ownership of fd.
  90         if (!TextFormat::Print(mapping_proto, &output)) {
  91                 // TODO: Don't overwrite the old file (if any) on error.
  92                 output.Close();
  93                 return false;
  94         }
  95
  96         output.Close();
  97         return true;
  98 }
  99
 100 void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
 101 {
 102         lock_guard<mutex> lock(mu);
 103         if (mapping_proto) {
 104                 mapping_proto->CopyFrom(new_mapping);
 105         } else {
 106                 mapping_proto.reset(new MIDIMappingProto(new_mapping));
 107         }
 108
 109         num_controller_banks = min(max(mapping_proto->num_controller_banks(), 1), 5);
 110         current_controller_bank = 0;
 111
 112         receiver->clear_all_highlights();
 113         update_highlights();
 114 }
 115
 116 void MIDIMapper::start_thread()
 117 {
 118         midi_thread = thread(&MIDIMapper::thread_func, this);
 119 }
 120
 121 const MIDIMappingProto &MIDIMapper::get_current_mapping() const
 122 {
 123         lock_guard<mutex> lock(mu);
 124         return *mapping_proto;
 125 }
 126
 127 ControllerReceiver *MIDIMapper::set_receiver(ControllerReceiver *new_receiver)
 128 {
 129         lock_guard<mutex> lock(mu);
 130         swap(receiver, new_receiver);
 131         return new_receiver;  // Now old receiver.
 132 }
 133
 134 #define RETURN_ON_ERROR(msg, expr) do {                            \
 135         int err = (expr);                                          \
 136         if (err < 0) {                                             \
 137                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
 138                 return;                                            \
 139         }                                                          \
 140 } while (false)
 141
 142 #define WARN_ON_ERROR(msg, expr) do {                              \
 143         int err = (expr);                                          \
 144         if (err < 0) {                                             \
 145                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
 146         }                                                          \
 147 } while (false)
 148
 149
 150 void MIDIMapper::thread_func()
 151 {
 152         pthread_setname_np(pthread_self(), "MIDIMapper");
 153
 154         snd_seq_t *seq;
 155         int err;
 156
 157         RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
 158         RETURN_ON_ERROR("snd_seq_nonblock", snd_seq_nonblock(seq, 1));
 159         RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
 160         RETURN_ON_ERROR("snd_seq_create_simple_port",
 161                 snd_seq_create_simple_port(seq, "nageru",
 162                         SND_SEQ_PORT_CAP_READ |
 163                                 SND_SEQ_PORT_CAP_SUBS_READ |
 164                                 SND_SEQ_PORT_CAP_WRITE |
 165                                 SND_SEQ_PORT_CAP_SUBS_WRITE,
 166                         SND_SEQ_PORT_TYPE_MIDI_GENERIC |
 167                                 SND_SEQ_PORT_TYPE_APPLICATION));
 168
 169         int queue_id = snd_seq_alloc_queue(seq);
 170         RETURN_ON_ERROR("snd_seq_create_queue", queue_id);
 171         RETURN_ON_ERROR("snd_seq_start_queue", snd_seq_start_queue(seq, queue_id, nullptr));
 172
 173         // The sequencer object is now ready to be used from other threads.
 174         {
 175                 lock_guard<mutex> lock(mu);
 176                 alsa_seq = seq;
 177                 alsa_queue_id = queue_id;
 178         }
 179
 180         // Listen to the announce port (0:1), which will tell us about new ports.
 181         RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, /*client=*/0, /*port=*/1));
 182
 183         // Now go through all ports and subscribe to them.
 184         snd_seq_client_info_t *cinfo;
 185         snd_seq_client_info_alloca(&cinfo);
 186
 187         snd_seq_client_info_set_client(cinfo, -1);
 188         while (snd_seq_query_next_client(seq, cinfo) >= 0) {
 189                 int client = snd_seq_client_info_get_client(cinfo);
 190
 191                 snd_seq_port_info_t *pinfo;
 192                 snd_seq_port_info_alloca(&pinfo);
 193
 194                 snd_seq_port_info_set_client(pinfo, client);
 195                 snd_seq_port_info_set_port(pinfo, -1);
 196                 while (snd_seq_query_next_port(seq, pinfo) >= 0) {
 197                         constexpr int mask = SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ;
 198                         if ((snd_seq_port_info_get_capability(pinfo) & mask) == mask) {
 199                                 lock_guard<mutex> lock(mu);
 200                                 subscribe_to_port_lock_held(seq, *snd_seq_port_info_get_addr(pinfo));
 201                         }
 202                 }
 203         }
 204
 205         int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
 206         unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
 207
 208         while (!should_quit) {
 209                 snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
 210                 fds[num_alsa_fds].fd = should_quit_fd;
 211                 fds[num_alsa_fds].events = POLLIN;
 212                 fds[num_alsa_fds].revents = 0;
 213
 214                 err = poll(fds.get(), num_alsa_fds + 1, -1);
 215                 if (err == 0 || (err == -1 && errno == EINTR)) {
 216                         continue;
 217                 }
 218                 if (err == -1) {
 219                         perror("poll");
 220                         break;
 221                 }
 222                 if (fds[num_alsa_fds].revents) {
 223                         // Activity on should_quit_fd.
 224                         break;
 225                 }
 226
 227                 // Seemingly we can get multiple events in a single poll,
 228                 // and if we don't handle them all, poll will _not_ alert us!
 229                 while (!should_quit) {
 230                         snd_seq_event_t *event;
 231                         err = snd_seq_event_input(seq, &event);
 232                         if (err < 0) {
 233                                 if (err == -EINTR) continue;
 234                                 if (err == -EAGAIN) break;
 235                                 if (err == -ENOSPC) {
 236                                         fprintf(stderr, "snd_seq_event_input: Some events were lost.\n");
 237                                         continue;
 238                                 }
 239                                 fprintf(stderr, "snd_seq_event_input: %s\n", snd_strerror(err));
 240                                 return;
 241                         }
 242                         if (event) {
 243                                 handle_event(seq, event);
 244                         }
 245                 }
 246         }
 247 }
 248
 249 void MIDIMapper::handle_event(snd_seq_t *seq, snd_seq_event_t *event)
 250 {
 251         if (event->source.client == snd_seq_client_id(seq)) {
 252                 // Ignore events we sent out ourselves.
 253                 return;
 254         }
 255
 256         lock_guard<mutex> lock(mu);
 257         switch (event->type) {
 258         case SND_SEQ_EVENT_CONTROLLER: {
 259                 const int controller = event->data.control.param;
 260                 const float value = map_controller_to_float(event->data.control.value);
 261
 262                 receiver->controller_changed(controller);
 263
 264                 // Global controllers.
 265                 match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
 266                         value, bind(&ControllerReceiver::set_locut, receiver, _2));
 267                 match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
 268                         value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
 269                 match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
 270                         value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
 271
 272                 // Bus controllers.
 273                 match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
 274                         value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
 275                 match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
 276                         value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
 277                 match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
 278                         value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
 279                 match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
 280                         value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
 281                 match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
 282                         value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
 283                 match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
 284                         value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
 285                 break;
 286         }
 287         case SND_SEQ_EVENT_NOTEON: {
 288                 const int note = event->data.note.note;
 289
 290                 receiver->note_on(note);
 291
 292                 for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 293                         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 294                         if (bus_mapping.has_prev_bank() &&
 295                             bus_mapping.prev_bank().note_number() == note) {
 296                                 current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
 297                                 update_highlights();
 298                                 update_lights_lock_held();
 299                         }
 300                         if (bus_mapping.has_next_bank() &&
 301                             bus_mapping.next_bank().note_number() == note) {
 302                                 current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
 303                                 update_highlights();
 304                                 update_lights_lock_held();
 305                         }
 306                         if (bus_mapping.has_select_bank_1() &&
 307                             bus_mapping.select_bank_1().note_number() == note) {
 308                                 current_controller_bank = 0;
 309                                 update_highlights();
 310                                 update_lights_lock_held();
 311                         }
 312                         if (bus_mapping.has_select_bank_2() &&
 313                             bus_mapping.select_bank_2().note_number() == note &&
 314                             num_controller_banks >= 2) {
 315                                 current_controller_bank = 1;
 316                                 update_highlights();
 317                                 update_lights_lock_held();
 318                         }
 319                         if (bus_mapping.has_select_bank_3() &&
 320                             bus_mapping.select_bank_3().note_number() == note &&
 321                             num_controller_banks >= 3) {
 322                                 current_controller_bank = 2;
 323                                 update_highlights();
 324                                 update_lights_lock_held();
 325                         }
 326                         if (bus_mapping.has_select_bank_4() &&
 327                             bus_mapping.select_bank_4().note_number() == note &&
 328                             num_controller_banks >= 4) {
 329                                 current_controller_bank = 3;
 330                                 update_highlights();
 331                                 update_lights_lock_held();
 332                         }
 333                         if (bus_mapping.has_select_bank_5() &&
 334                             bus_mapping.select_bank_5().note_number() == note &&
 335                             num_controller_banks >= 5) {
 336                                 current_controller_bank = 4;
 337                                 update_highlights();
 338                                 update_lights_lock_held();
 339                         }
 340                 }
 341
 342                 match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
 343                         bind(&ControllerReceiver::toggle_locut, receiver, _1));
 344                 match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
 345                         bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
 346                 match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
 347                         bind(&ControllerReceiver::toggle_compressor, receiver, _1));
 348                 match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 349                         bind(&ControllerReceiver::clear_peak, receiver, _1));
 350                 match_button(note, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 351                         bind(&ControllerReceiver::toggle_mute, receiver, _1));
 352                 match_button(note, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber,
 353                         bind(&ControllerReceiver::toggle_limiter, receiver));
 354                 match_button(note, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber,
 355                         bind(&ControllerReceiver::toggle_auto_makeup_gain, receiver));
 356                 break;
 357         }
 358         case SND_SEQ_EVENT_PORT_START:
 359                 subscribe_to_port_lock_held(seq, event->data.addr);
 360                 break;
 361         case SND_SEQ_EVENT_PORT_EXIT:
 362                 printf("MIDI port %d:%d went away.\n", event->data.addr.client, event->data.addr.port);
 363                 break;
 364         case SND_SEQ_EVENT_PORT_SUBSCRIBED:
 365                 if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
 366                     event->data.connect.sender.client != snd_seq_client_id(seq) &&
 367                     event->data.connect.dest.client == snd_seq_client_id(seq)) {
 368                         ++num_subscribed_ports;
 369                         update_highlights();
 370                 }
 371                 break;
 372         case SND_SEQ_EVENT_PORT_UNSUBSCRIBED:
 373                 if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
 374                     event->data.connect.sender.client != snd_seq_client_id(seq) &&
 375                     event->data.connect.dest.client == snd_seq_client_id(seq)) {
 376                         --num_subscribed_ports;
 377                         update_highlights();
 378                 }
 379                 break;
 380         case SND_SEQ_EVENT_NOTEOFF:
 381         case SND_SEQ_EVENT_CLIENT_START:
 382         case SND_SEQ_EVENT_CLIENT_EXIT:
 383         case SND_SEQ_EVENT_CLIENT_CHANGE:
 384         case SND_SEQ_EVENT_PORT_CHANGE:
 385                 break;
 386         default:
 387                 printf("Ignoring MIDI event of unknown type %d.\n", event->type);
 388         }
 389 }
 390
 391 void MIDIMapper::subscribe_to_port_lock_held(snd_seq_t *seq, const snd_seq_addr_t &addr)
 392 {
 393         // Client 0 (SNDRV_SEQ_CLIENT_SYSTEM) is basically the system; ignore it.
 394         // MIDI through (SNDRV_SEQ_CLIENT_DUMMY) echoes back what we give it, so ignore that, too.
 395         if (addr.client == 0 || addr.client == 14) {
 396                 return;
 397         }
 398
 399         // Don't listen to ourselves.
 400         if (addr.client == snd_seq_client_id(seq)) {
 401                 return;
 402         }
 403
 404         int err = snd_seq_connect_from(seq, 0, addr.client, addr.port);
 405         if (err < 0) {
 406                 // Just print out a warning (i.e., don't die); it could
 407                 // very well just be e.g. another application.
 408                 printf("Couldn't subscribe to MIDI port %d:%d (%s).\n",
 409                         addr.client, addr.port, snd_strerror(err));
 410         } else {
 411                 printf("Subscribed to MIDI port %d:%d.\n", addr.client, addr.port);
 412         }
 413
 414         // For sending data back.
 415         err = snd_seq_connect_to(seq, 0, addr.client, addr.port);
 416         if (err < 0) {
 417                 printf("Couldn't subscribe MIDI port %d:%d (%s) to us.\n",
 418                         addr.client, addr.port, snd_strerror(err));
 419         } else {
 420                 printf("Subscribed MIDI port %d:%d to us.\n", addr.client, addr.port);
 421         }
 422
 423         current_light_status.clear();  // The current state of the device is unknown.
 424         update_lights_lock_held();
 425 }
 426
 427 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
 428 {
 429         if (bank_mismatch(bank_field_number)) {
 430                 return;
 431         }
 432
 433         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 434                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 435
 436                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 437                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 438                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 439                         continue;
 440                 }
 441                 const MIDIControllerProto &controller_proto =
 442                         static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 443                 if (controller_proto.controller_number() == controller) {
 444                         func(bus_idx, value);
 445                 }
 446         }
 447 }
 448
 449 void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
 450 {
 451         if (bank_mismatch(bank_field_number)) {
 452                 return;
 453         }
 454
 455         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 456                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 457
 458                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 459                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 460                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 461                         continue;
 462                 }
 463                 const MIDIButtonProto &button_proto =
 464                         static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 465                 if (button_proto.note_number() == note) {
 466                         func(bus_idx);
 467                 }
 468         }
 469 }
 470
 471 bool MIDIMapper::has_active_controller(unsigned bus_idx, int field_number, int bank_field_number)
 472 {
 473         if (bank_mismatch(bank_field_number)) {
 474                 return false;
 475         }
 476
 477         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 478         const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 479         const Reflection *bus_reflection = bus_mapping.GetReflection();
 480         return bus_reflection->HasField(bus_mapping, descriptor);
 481 }
 482
 483 bool MIDIMapper::bank_mismatch(int bank_field_number)
 484 {
 485         const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
 486         const Reflection *reflection = mapping_proto->GetReflection();
 487         return (reflection->HasField(*mapping_proto, bank_descriptor) &&
 488                 reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
 489 }
 490
 491 void MIDIMapper::refresh_highlights()
 492 {
 493         receiver->clear_all_highlights();
 494         update_highlights();
 495 }
 496
 497 void MIDIMapper::refresh_lights()
 498 {
 499         lock_guard<mutex> lock(mu);
 500         update_lights_lock_held();
 501 }
 502
 503 void MIDIMapper::update_highlights()
 504 {
 505         if (num_subscribed_ports.load() == 0) {
 506                 receiver->clear_all_highlights();
 507                 return;
 508         }
 509
 510         // Global controllers.
 511         bool highlight_locut = false;
 512         bool highlight_limiter_threshold = false;
 513         bool highlight_makeup_gain = false;
 514         bool highlight_toggle_limiter = false;
 515         bool highlight_toggle_auto_makeup_gain = false;
 516         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 517                 if (has_active_controller(
 518                         bus_idx, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber)) {
 519                         highlight_locut = true;
 520                 }
 521                 if (has_active_controller(
 522                         bus_idx, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber)) {
 523                         highlight_limiter_threshold = true;
 524                 }
 525                 if (has_active_controller(
 526                         bus_idx, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber)) {
 527                         highlight_makeup_gain = true;
 528                 }
 529                 if (has_active_controller(
 530                         bus_idx, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber)) {
 531                         highlight_toggle_limiter = true;
 532                 }
 533                 if (has_active_controller(
 534                         bus_idx, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber)) {
 535                         highlight_toggle_auto_makeup_gain = true;
 536                 }
 537         }
 538         receiver->highlight_locut(highlight_locut);
 539         receiver->highlight_limiter_threshold(highlight_limiter_threshold);
 540         receiver->highlight_makeup_gain(highlight_makeup_gain);
 541         receiver->highlight_toggle_limiter(highlight_toggle_limiter);
 542         receiver->highlight_toggle_auto_makeup_gain(highlight_toggle_auto_makeup_gain);
 543
 544         // Per-bus controllers.
 545         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 546                 receiver->highlight_treble(bus_idx, has_active_controller(
 547                         bus_idx, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber));
 548                 receiver->highlight_mid(bus_idx, has_active_controller(
 549                         bus_idx, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber));
 550                 receiver->highlight_bass(bus_idx, has_active_controller(
 551                         bus_idx, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber));
 552                 receiver->highlight_gain(bus_idx, has_active_controller(
 553                         bus_idx, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber));
 554                 receiver->highlight_compressor_threshold(bus_idx, has_active_controller(
 555                         bus_idx, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber));
 556                 receiver->highlight_fader(bus_idx, has_active_controller(
 557                         bus_idx, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber));
 558                 receiver->highlight_mute(bus_idx, has_active_controller(
 559                         bus_idx, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kToggleMuteBankFieldNumber));
 560                 receiver->highlight_toggle_locut(bus_idx, has_active_controller(
 561                         bus_idx, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber));
 562                 receiver->highlight_toggle_auto_gain_staging(bus_idx, has_active_controller(
 563                         bus_idx, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber));
 564                 receiver->highlight_toggle_compressor(bus_idx, has_active_controller(
 565                         bus_idx, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber));
 566         }
 567 }
 568
 569 void MIDIMapper::update_lights_lock_held()
 570 {
 571         if (alsa_seq == nullptr || global_audio_mixer == nullptr) {
 572                 return;
 573         }
 574
 575         set<unsigned> active_lights;  // Desired state.
 576         if (current_controller_bank == 0) {
 577                 activate_lights_all_buses(MIDIMappingBusProto::kBank1IsSelectedFieldNumber, &active_lights);
 578         }
 579         if (current_controller_bank == 1) {
 580                 activate_lights_all_buses(MIDIMappingBusProto::kBank2IsSelectedFieldNumber, &active_lights);
 581         }
 582         if (current_controller_bank == 2) {
 583                 activate_lights_all_buses(MIDIMappingBusProto::kBank3IsSelectedFieldNumber, &active_lights);
 584         }
 585         if (current_controller_bank == 3) {
 586                 activate_lights_all_buses(MIDIMappingBusProto::kBank4IsSelectedFieldNumber, &active_lights);
 587         }
 588         if (current_controller_bank == 4) {
 589                 activate_lights_all_buses(MIDIMappingBusProto::kBank5IsSelectedFieldNumber, &active_lights);
 590         }
 591         if (global_audio_mixer->get_limiter_enabled()) {
 592                 activate_lights_all_buses(MIDIMappingBusProto::kLimiterIsOnFieldNumber, &active_lights);
 593         }
 594         if (global_audio_mixer->get_final_makeup_gain_auto()) {
 595                 activate_lights_all_buses(MIDIMappingBusProto::kAutoMakeupGainIsOnFieldNumber, &active_lights);
 596         }
 597         unsigned num_buses = min<unsigned>(global_audio_mixer->num_buses(), mapping_proto->bus_mapping_size());
 598         for (unsigned bus_idx = 0; bus_idx < num_buses; ++bus_idx) {
 599                 if (global_audio_mixer->get_mute(bus_idx)) {
 600                         activate_lights(bus_idx, MIDIMappingBusProto::kIsMutedFieldNumber, &active_lights);
 601                 }
 602                 if (global_audio_mixer->get_locut_enabled(bus_idx)) {
 603                         activate_lights(bus_idx, MIDIMappingBusProto::kLocutIsOnFieldNumber, &active_lights);
 604                 }
 605                 if (global_audio_mixer->get_gain_staging_auto(bus_idx)) {
 606                         activate_lights(bus_idx, MIDIMappingBusProto::kAutoGainStagingIsOnFieldNumber, &active_lights);
 607                 }
 608                 if (global_audio_mixer->get_compressor_enabled(bus_idx)) {
 609                         activate_lights(bus_idx, MIDIMappingBusProto::kCompressorIsOnFieldNumber, &active_lights);
 610                 }
 611                 if (has_peaked[bus_idx]) {
 612                         activate_lights(bus_idx, MIDIMappingBusProto::kHasPeakedFieldNumber, &active_lights);
 613                 }
 614         }
 615
 616         unsigned num_events = 0;
 617         for (unsigned note_num = 1; note_num <= 127; ++note_num) {
 618                 bool active = active_lights.count(note_num);
 619                 if (current_light_status.count(note_num) &&
 620                     current_light_status[note_num] == active) {
 621                         // Already known to be in the desired state.
 622                         continue;
 623                 }
 624
 625                 snd_seq_event_t ev;
 626                 snd_seq_ev_clear(&ev);
 627
 628                 // Some devices drop events if we throw them onto them
 629                 // too quickly. Add a 1 ms delay for each.
 630                 snd_seq_real_time_t tm{0, num_events++ * 1000000};
 631                 snd_seq_ev_schedule_real(&ev, alsa_queue_id, true, &tm);
 632                 snd_seq_ev_set_source(&ev, 0);
 633                 snd_seq_ev_set_subs(&ev);
 634
 635                 // For some reason, not all devices respond to note off.
 636                 // Use note-on with velocity of 0 (which is equivalent) instead.
 637                 snd_seq_ev_set_noteon(&ev, /*channel=*/0, note_num, active ? 127 : 0);
 638                 WARN_ON_ERROR("snd_seq_event_output", snd_seq_event_output(alsa_seq, &ev));
 639                 current_light_status[note_num] = active;
 640         }
 641         WARN_ON_ERROR("snd_seq_drain_output", snd_seq_drain_output(alsa_seq));
 642 }
 643
 644 void MIDIMapper::activate_lights(unsigned bus_idx, int field_number, set<unsigned> *active_lights)
 645 {
 646         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 647
 648         const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 649         const Reflection *bus_reflection = bus_mapping.GetReflection();
 650         if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 651                 return;
 652         }
 653         const MIDILightProto &light_proto =
 654                 static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 655         active_lights->insert(light_proto.note_number());
 656 }
 657
 658 void MIDIMapper::activate_lights_all_buses(int field_number, set<unsigned> *active_lights)
 659 {
 660         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 661                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 662
 663                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 664                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 665                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 666                         continue;
 667                 }
 668                 const MIDILightProto &light_proto =
 669                         static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 670                 active_lights->insert(light_proto.note_number());
 671         }
 672 }