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                                 fprintf(stderr, "snd_seq_event_input: %s\n", snd_strerror(err));
 236                                 return;
 237                         }
 238                         if (event) {
 239                                 handle_event(seq, event);
 240                         }
 241                 }
 242         }
 243 }
 244
 245 void MIDIMapper::handle_event(snd_seq_t *seq, snd_seq_event_t *event)
 246 {
 247         if (event->source.client == snd_seq_client_id(seq)) {
 248                 // Ignore events we sent out ourselves.
 249                 return;
 250         }
 251
 252         lock_guard<mutex> lock(mu);
 253         switch (event->type) {
 254         case SND_SEQ_EVENT_CONTROLLER: {
 255                 const int controller = event->data.control.param;
 256                 const float value = map_controller_to_float(event->data.control.value);
 257
 258                 receiver->controller_changed(controller);
 259
 260                 // Global controllers.
 261                 match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
 262                         value, bind(&ControllerReceiver::set_locut, receiver, _2));
 263                 match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
 264                         value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
 265                 match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
 266                         value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
 267
 268                 // Bus controllers.
 269                 match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
 270                         value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
 271                 match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
 272                         value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
 273                 match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
 274                         value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
 275                 match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
 276                         value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
 277                 match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
 278                         value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
 279                 match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
 280                         value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
 281                 break;
 282         }
 283         case SND_SEQ_EVENT_NOTEON: {
 284                 const int note = event->data.note.note;
 285
 286                 receiver->note_on(note);
 287
 288                 for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 289                         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 290                         if (bus_mapping.has_prev_bank() &&
 291                             bus_mapping.prev_bank().note_number() == note) {
 292                                 current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
 293                                 update_highlights();
 294                                 update_lights_lock_held();
 295                         }
 296                         if (bus_mapping.has_next_bank() &&
 297                             bus_mapping.next_bank().note_number() == note) {
 298                                 current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
 299                                 update_highlights();
 300                                 update_lights_lock_held();
 301                         }
 302                         if (bus_mapping.has_select_bank_1() &&
 303                             bus_mapping.select_bank_1().note_number() == note) {
 304                                 current_controller_bank = 0;
 305                                 update_highlights();
 306                                 update_lights_lock_held();
 307                         }
 308                         if (bus_mapping.has_select_bank_2() &&
 309                             bus_mapping.select_bank_2().note_number() == note &&
 310                             num_controller_banks >= 2) {
 311                                 current_controller_bank = 1;
 312                                 update_highlights();
 313                                 update_lights_lock_held();
 314                         }
 315                         if (bus_mapping.has_select_bank_3() &&
 316                             bus_mapping.select_bank_3().note_number() == note &&
 317                             num_controller_banks >= 3) {
 318                                 current_controller_bank = 2;
 319                                 update_highlights();
 320                                 update_lights_lock_held();
 321                         }
 322                         if (bus_mapping.has_select_bank_4() &&
 323                             bus_mapping.select_bank_4().note_number() == note &&
 324                             num_controller_banks >= 4) {
 325                                 current_controller_bank = 3;
 326                                 update_highlights();
 327                                 update_lights_lock_held();
 328                         }
 329                         if (bus_mapping.has_select_bank_5() &&
 330                             bus_mapping.select_bank_5().note_number() == note &&
 331                             num_controller_banks >= 5) {
 332                                 current_controller_bank = 4;
 333                                 update_highlights();
 334                                 update_lights_lock_held();
 335                         }
 336                 }
 337
 338                 match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
 339                         bind(&ControllerReceiver::toggle_locut, receiver, _1));
 340                 match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
 341                         bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
 342                 match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
 343                         bind(&ControllerReceiver::toggle_compressor, receiver, _1));
 344                 match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 345                         bind(&ControllerReceiver::clear_peak, receiver, _1));
 346                 match_button(note, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 347                         bind(&ControllerReceiver::toggle_mute, receiver, _1));
 348                 match_button(note, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber,
 349                         bind(&ControllerReceiver::toggle_limiter, receiver));
 350                 match_button(note, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber,
 351                         bind(&ControllerReceiver::toggle_auto_makeup_gain, receiver));
 352                 break;
 353         }
 354         case SND_SEQ_EVENT_PORT_START:
 355                 subscribe_to_port_lock_held(seq, event->data.addr);
 356                 break;
 357         case SND_SEQ_EVENT_PORT_EXIT:
 358                 printf("MIDI port %d:%d went away.\n", event->data.addr.client, event->data.addr.port);
 359                 break;
 360         case SND_SEQ_EVENT_PORT_SUBSCRIBED:
 361                 if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
 362                     event->data.connect.sender.client != snd_seq_client_id(seq) &&
 363                     event->data.connect.dest.client == snd_seq_client_id(seq)) {
 364                         ++num_subscribed_ports;
 365                         update_highlights();
 366                 }
 367                 break;
 368         case SND_SEQ_EVENT_PORT_UNSUBSCRIBED:
 369                 if (event->data.connect.sender.client != 0 &&  // Ignore system senders.
 370                     event->data.connect.sender.client != snd_seq_client_id(seq) &&
 371                     event->data.connect.dest.client == snd_seq_client_id(seq)) {
 372                         --num_subscribed_ports;
 373                         update_highlights();
 374                 }
 375                 break;
 376         case SND_SEQ_EVENT_NOTEOFF:
 377         case SND_SEQ_EVENT_CLIENT_START:
 378         case SND_SEQ_EVENT_CLIENT_EXIT:
 379         case SND_SEQ_EVENT_CLIENT_CHANGE:
 380         case SND_SEQ_EVENT_PORT_CHANGE:
 381                 break;
 382         default:
 383                 printf("Ignoring MIDI event of unknown type %d.\n", event->type);
 384         }
 385 }
 386
 387 void MIDIMapper::subscribe_to_port_lock_held(snd_seq_t *seq, const snd_seq_addr_t &addr)
 388 {
 389         // Client 0 is basically the system; ignore it.
 390         if (addr.client == 0) {
 391                 return;
 392         }
 393
 394         int err = snd_seq_connect_from(seq, 0, addr.client, addr.port);
 395         if (err < 0) {
 396                 // Just print out a warning (i.e., don't die); it could
 397                 // very well just be e.g. another application.
 398                 printf("Couldn't subscribe to MIDI port %d:%d (%s).\n",
 399                         addr.client, addr.port, snd_strerror(err));
 400         } else {
 401                 printf("Subscribed to MIDI port %d:%d.\n", addr.client, addr.port);
 402         }
 403
 404         // For sending data back.
 405         err = snd_seq_connect_to(seq, 0, addr.client, addr.port);
 406         if (err < 0) {
 407                 printf("Couldn't subscribe MIDI port %d:%d (%s) to us.\n",
 408                         addr.client, addr.port, snd_strerror(err));
 409         } else {
 410                 printf("Subscribed MIDI port %d:%d to us.\n", addr.client, addr.port);
 411         }
 412
 413         current_light_status.clear();  // The current state of the device is unknown.
 414         update_lights_lock_held();
 415 }
 416
 417 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
 418 {
 419         if (bank_mismatch(bank_field_number)) {
 420                 return;
 421         }
 422
 423         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 424                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 425
 426                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 427                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 428                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 429                         continue;
 430                 }
 431                 const MIDIControllerProto &controller_proto =
 432                         static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 433                 if (controller_proto.controller_number() == controller) {
 434                         func(bus_idx, value);
 435                 }
 436         }
 437 }
 438
 439 void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
 440 {
 441         if (bank_mismatch(bank_field_number)) {
 442                 return;
 443         }
 444
 445         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 446                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 447
 448                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 449                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 450                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 451                         continue;
 452                 }
 453                 const MIDIButtonProto &button_proto =
 454                         static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 455                 if (button_proto.note_number() == note) {
 456                         func(bus_idx);
 457                 }
 458         }
 459 }
 460
 461 bool MIDIMapper::has_active_controller(unsigned bus_idx, int field_number, int bank_field_number)
 462 {
 463         if (bank_mismatch(bank_field_number)) {
 464                 return false;
 465         }
 466
 467         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 468         const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 469         const Reflection *bus_reflection = bus_mapping.GetReflection();
 470         return bus_reflection->HasField(bus_mapping, descriptor);
 471 }
 472
 473 bool MIDIMapper::bank_mismatch(int bank_field_number)
 474 {
 475         const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
 476         const Reflection *reflection = mapping_proto->GetReflection();
 477         return (reflection->HasField(*mapping_proto, bank_descriptor) &&
 478                 reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
 479 }
 480
 481 void MIDIMapper::refresh_highlights()
 482 {
 483         receiver->clear_all_highlights();
 484         update_highlights();
 485 }
 486
 487 void MIDIMapper::refresh_lights()
 488 {
 489         lock_guard<mutex> lock(mu);
 490         update_lights_lock_held();
 491 }
 492
 493 void MIDIMapper::update_highlights()
 494 {
 495         if (num_subscribed_ports.load() == 0) {
 496                 receiver->clear_all_highlights();
 497                 return;
 498         }
 499
 500         // Global controllers.
 501         bool highlight_locut = false;
 502         bool highlight_limiter_threshold = false;
 503         bool highlight_makeup_gain = false;
 504         bool highlight_toggle_limiter = false;
 505         bool highlight_toggle_auto_makeup_gain = false;
 506         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 507                 if (has_active_controller(
 508                         bus_idx, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber)) {
 509                         highlight_locut = true;
 510                 }
 511                 if (has_active_controller(
 512                         bus_idx, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber)) {
 513                         highlight_limiter_threshold = true;
 514                 }
 515                 if (has_active_controller(
 516                         bus_idx, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber)) {
 517                         highlight_makeup_gain = true;
 518                 }
 519                 if (has_active_controller(
 520                         bus_idx, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber)) {
 521                         highlight_toggle_limiter = true;
 522                 }
 523                 if (has_active_controller(
 524                         bus_idx, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber)) {
 525                         highlight_toggle_auto_makeup_gain = true;
 526                 }
 527         }
 528         receiver->highlight_locut(highlight_locut);
 529         receiver->highlight_limiter_threshold(highlight_limiter_threshold);
 530         receiver->highlight_makeup_gain(highlight_makeup_gain);
 531         receiver->highlight_toggle_limiter(highlight_toggle_limiter);
 532         receiver->highlight_toggle_auto_makeup_gain(highlight_toggle_auto_makeup_gain);
 533
 534         // Per-bus controllers.
 535         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 536                 receiver->highlight_treble(bus_idx, has_active_controller(
 537                         bus_idx, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber));
 538                 receiver->highlight_mid(bus_idx, has_active_controller(
 539                         bus_idx, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber));
 540                 receiver->highlight_bass(bus_idx, has_active_controller(
 541                         bus_idx, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber));
 542                 receiver->highlight_gain(bus_idx, has_active_controller(
 543                         bus_idx, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber));
 544                 receiver->highlight_compressor_threshold(bus_idx, has_active_controller(
 545                         bus_idx, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber));
 546                 receiver->highlight_fader(bus_idx, has_active_controller(
 547                         bus_idx, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber));
 548                 receiver->highlight_mute(bus_idx, has_active_controller(
 549                         bus_idx, MIDIMappingBusProto::kToggleMuteFieldNumber, MIDIMappingProto::kToggleMuteBankFieldNumber));
 550                 receiver->highlight_toggle_locut(bus_idx, has_active_controller(
 551                         bus_idx, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber));
 552                 receiver->highlight_toggle_auto_gain_staging(bus_idx, has_active_controller(
 553                         bus_idx, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber));
 554                 receiver->highlight_toggle_compressor(bus_idx, has_active_controller(
 555                         bus_idx, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber));
 556         }
 557 }
 558
 559 void MIDIMapper::update_lights_lock_held()
 560 {
 561         if (alsa_seq == nullptr || global_audio_mixer == nullptr) {
 562                 return;
 563         }
 564
 565         set<unsigned> active_lights;  // Desired state.
 566         if (current_controller_bank == 0) {
 567                 activate_lights_all_buses(MIDIMappingBusProto::kBank1IsSelectedFieldNumber, &active_lights);
 568         }
 569         if (current_controller_bank == 1) {
 570                 activate_lights_all_buses(MIDIMappingBusProto::kBank2IsSelectedFieldNumber, &active_lights);
 571         }
 572         if (current_controller_bank == 2) {
 573                 activate_lights_all_buses(MIDIMappingBusProto::kBank3IsSelectedFieldNumber, &active_lights);
 574         }
 575         if (current_controller_bank == 3) {
 576                 activate_lights_all_buses(MIDIMappingBusProto::kBank4IsSelectedFieldNumber, &active_lights);
 577         }
 578         if (current_controller_bank == 4) {
 579                 activate_lights_all_buses(MIDIMappingBusProto::kBank5IsSelectedFieldNumber, &active_lights);
 580         }
 581         if (global_audio_mixer->get_limiter_enabled()) {
 582                 activate_lights_all_buses(MIDIMappingBusProto::kLimiterIsOnFieldNumber, &active_lights);
 583         }
 584         if (global_audio_mixer->get_final_makeup_gain_auto()) {
 585                 activate_lights_all_buses(MIDIMappingBusProto::kAutoMakeupGainIsOnFieldNumber, &active_lights);
 586         }
 587         unsigned num_buses = min<unsigned>(global_audio_mixer->num_buses(), mapping_proto->bus_mapping_size());
 588         for (unsigned bus_idx = 0; bus_idx < num_buses; ++bus_idx) {
 589                 if (global_audio_mixer->get_mute(bus_idx)) {
 590                         activate_lights(bus_idx, MIDIMappingBusProto::kIsMutedFieldNumber, &active_lights);
 591                 }
 592                 if (global_audio_mixer->get_locut_enabled(bus_idx)) {
 593                         activate_lights(bus_idx, MIDIMappingBusProto::kLocutIsOnFieldNumber, &active_lights);
 594                 }
 595                 if (global_audio_mixer->get_gain_staging_auto(bus_idx)) {
 596                         activate_lights(bus_idx, MIDIMappingBusProto::kAutoGainStagingIsOnFieldNumber, &active_lights);
 597                 }
 598                 if (global_audio_mixer->get_compressor_enabled(bus_idx)) {
 599                         activate_lights(bus_idx, MIDIMappingBusProto::kCompressorIsOnFieldNumber, &active_lights);
 600                 }
 601                 if (has_peaked[bus_idx]) {
 602                         activate_lights(bus_idx, MIDIMappingBusProto::kHasPeakedFieldNumber, &active_lights);
 603                 }
 604         }
 605
 606         unsigned num_events = 0;
 607         for (unsigned note_num = 1; note_num <= 127; ++note_num) {
 608                 bool active = active_lights.count(note_num);
 609                 if (current_light_status.count(note_num) &&
 610                     current_light_status[note_num] == active) {
 611                         // Already known to be in the desired state.
 612                         continue;
 613                 }
 614
 615                 snd_seq_event_t ev;
 616                 snd_seq_ev_clear(&ev);
 617
 618                 // Some devices drop events if we throw them onto them
 619                 // too quickly. Add a 1 ms delay for each.
 620                 snd_seq_real_time_t tm{0, num_events++ * 1000000};
 621                 snd_seq_ev_schedule_real(&ev, alsa_queue_id, true, &tm);
 622                 snd_seq_ev_set_source(&ev, 0);
 623                 snd_seq_ev_set_subs(&ev);
 624
 625                 // For some reason, not all devices respond to note off.
 626                 // Use note-on with velocity of 0 (which is equivalent) instead.
 627                 snd_seq_ev_set_noteon(&ev, /*channel=*/0, note_num, active ? 127 : 0);
 628                 WARN_ON_ERROR("snd_seq_event_output", snd_seq_event_output(alsa_seq, &ev));
 629                 current_light_status[note_num] = active;
 630         }
 631         WARN_ON_ERROR("snd_seq_drain_output", snd_seq_drain_output(alsa_seq));
 632 }
 633
 634 void MIDIMapper::activate_lights(unsigned bus_idx, int field_number, set<unsigned> *active_lights)
 635 {
 636         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 637
 638         const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 639         const Reflection *bus_reflection = bus_mapping.GetReflection();
 640         if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 641                 return;
 642         }
 643         const MIDILightProto &light_proto =
 644                 static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 645         active_lights->insert(light_proto.note_number());
 646 }
 647
 648 void MIDIMapper::activate_lights_all_buses(int field_number, set<unsigned> *active_lights)
 649 {
 650         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 651                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 652
 653                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 654                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 655                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 656                         continue;
 657                 }
 658                 const MIDILightProto &light_proto =
 659                         static_cast<const MIDILightProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 660                 active_lights->insert(light_proto.note_number());
 661         }
 662 }