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