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

   1 #include "midi_mapper.h"
   2 #include "midi_mapping.pb.h"
   3
   4 #include <alsa/asoundlib.h>
   5 #include <google/protobuf/text_format.h>
   6 #include <google/protobuf/io/zero_copy_stream.h>
   7 #include <google/protobuf/io/zero_copy_stream_impl.h>
   8 #include <fcntl.h>
   9 #include <sys/eventfd.h>
  10
  11 #include <functional>
  12 #include <thread>
  13
  14 using namespace google::protobuf;
  15 using namespace std;
  16 using namespace std::placeholders;
  17
  18 namespace {
  19
  20 double map_controller_to_float(int val)
  21 {
  22         // Slightly hackish mapping so that we can represent exactly 0.0, 0.5 and 1.0.
  23         if (val <= 0) {
  24                 return 0.0;
  25         } else if (val >= 127) {
  26                 return 1.0;
  27         } else {
  28                 return (val + 0.5) / 127.0;
  29         }
  30 }
  31
  32 }  // namespace
  33
  34 MIDIMapper::MIDIMapper(ControllerReceiver *receiver)
  35         : receiver(receiver), mapping_proto(new MIDIMappingProto)
  36 {
  37         should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
  38         assert(should_quit_fd != -1);
  39         refresh_highlights();
  40 }
  41
  42 MIDIMapper::~MIDIMapper()
  43 {
  44         should_quit = true;
  45         const uint64_t one = 1;
  46         write(should_quit_fd, &one, sizeof(one));
  47         midi_thread.join();
  48         close(should_quit_fd);
  49 }
  50
  51 bool load_midi_mapping_from_file(const string &filename, MIDIMappingProto *new_mapping)
  52 {
  53         // Read and parse the protobuf from disk.
  54         int fd = open(filename.c_str(), O_RDONLY);
  55         if (fd == -1) {
  56                 perror(filename.c_str());
  57                 return false;
  58         }
  59         io::FileInputStream input(fd);  // Takes ownership of fd.
  60         if (!TextFormat::Parse(&input, new_mapping)) {
  61                 input.Close();
  62                 return false;
  63         }
  64         input.Close();
  65         return true;
  66 }
  67
  68 bool save_midi_mapping_to_file(const MIDIMappingProto &mapping_proto, const string &filename)
  69 {
  70         // Save to disk. We use the text format because it's friendlier
  71         // for a user to look at and edit.
  72         int fd = open(filename.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
  73         if (fd == -1) {
  74                 perror(filename.c_str());
  75                 return false;
  76         }
  77         io::FileOutputStream output(fd);  // Takes ownership of fd.
  78         if (!TextFormat::Print(mapping_proto, &output)) {
  79                 // TODO: Don't overwrite the old file (if any) on error.
  80                 output.Close();
  81                 return false;
  82         }
  83
  84         output.Close();
  85         return true;
  86 }
  87
  88 void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
  89 {
  90         lock_guard<mutex> lock(mapping_mu);
  91         if (mapping_proto) {
  92                 mapping_proto->CopyFrom(new_mapping);
  93         } else {
  94                 mapping_proto.reset(new MIDIMappingProto(new_mapping));
  95         }
  96
  97         num_controller_banks = min(max(mapping_proto->num_controller_banks(), 1), 5);
  98         current_controller_bank = 0;
  99
 100         receiver->clear_all_highlights();
 101         update_highlights();
 102 }
 103
 104 void MIDIMapper::start_thread()
 105 {
 106         midi_thread = thread(&MIDIMapper::thread_func, this);
 107 }
 108
 109 const MIDIMappingProto &MIDIMapper::get_current_mapping() const
 110 {
 111         lock_guard<mutex> lock(mapping_mu);
 112         return *mapping_proto;
 113 }
 114
 115 ControllerReceiver *MIDIMapper::set_receiver(ControllerReceiver *new_receiver)
 116 {
 117         lock_guard<mutex> lock(mapping_mu);
 118         swap(receiver, new_receiver);
 119         return new_receiver;  // Now old receiver.
 120 }
 121
 122 #define RETURN_ON_ERROR(msg, expr) do {                            \
 123         int err = (expr);                                          \
 124         if (err < 0) {                                             \
 125                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
 126                 return;                                            \
 127         }                                                          \
 128 } while (false)
 129
 130
 131 void MIDIMapper::thread_func()
 132 {
 133         snd_seq_t *seq;
 134         int err;
 135
 136         RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
 137         RETURN_ON_ERROR("snd_seq_nonblock", snd_seq_nonblock(seq, 1));
 138         RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
 139         RETURN_ON_ERROR("snd_seq_create_simple_port",
 140                 snd_seq_create_simple_port(seq, "nageru",
 141                         SND_SEQ_PORT_CAP_WRITE |
 142                         SND_SEQ_PORT_CAP_SUBS_WRITE,
 143                         SND_SEQ_PORT_TYPE_MIDI_GENERIC |
 144                         SND_SEQ_PORT_TYPE_APPLICATION));
 145
 146         // Listen to the announce port (0:1), which will tell us about new ports.
 147         RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, /*client=*/0, /*port=*/1));
 148
 149         // Now go through all ports and subscribe to them.
 150         snd_seq_client_info_t *cinfo;
 151         snd_seq_client_info_alloca(&cinfo);
 152
 153         snd_seq_client_info_set_client(cinfo, -1);
 154         while (snd_seq_query_next_client(seq, cinfo) >= 0) {
 155                 int client = snd_seq_client_info_get_client(cinfo);
 156
 157                 snd_seq_port_info_t *pinfo;
 158                 snd_seq_port_info_alloca(&pinfo);
 159
 160                 snd_seq_port_info_set_client(pinfo, client);
 161                 snd_seq_port_info_set_port(pinfo, -1);
 162                 while (snd_seq_query_next_port(seq, pinfo) >= 0) {
 163                         constexpr int mask = SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ;
 164                         if ((snd_seq_port_info_get_capability(pinfo) & mask) == mask) {
 165                                 subscribe_to_port(seq, *snd_seq_port_info_get_addr(pinfo));
 166                         }
 167                 }
 168         }
 169
 170         int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
 171         unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
 172
 173         while (!should_quit) {
 174                 snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
 175                 fds[num_alsa_fds].fd = should_quit_fd;
 176                 fds[num_alsa_fds].events = POLLIN;
 177                 fds[num_alsa_fds].revents = 0;
 178
 179                 err = poll(fds.get(), num_alsa_fds + 1, -1);
 180                 if (err == 0 || (err == -1 && errno == EINTR)) {
 181                         continue;
 182                 }
 183                 if (err == -1) {
 184                         perror("poll");
 185                         break;
 186                 }
 187                 if (fds[num_alsa_fds].revents) {
 188                         // Activity on should_quit_fd.
 189                         break;
 190                 }
 191
 192                 // Seemingly we can get multiple events in a single poll,
 193                 // and if we don't handle them all, poll will _not_ alert us!
 194                 while (!should_quit) {
 195                         snd_seq_event_t *event;
 196                         err = snd_seq_event_input(seq, &event);
 197                         if (err < 0) {
 198                                 if (err == -EINTR) continue;
 199                                 if (err == -EAGAIN) break;
 200                                 fprintf(stderr, "snd_seq_event_input: %s\n", snd_strerror(err));
 201                                 return;
 202                         }
 203                         if (event) {
 204                                 handle_event(seq, event);
 205                         }
 206                 }
 207         }
 208 }
 209
 210 void MIDIMapper::handle_event(snd_seq_t *seq, snd_seq_event_t *event)
 211 {
 212         lock_guard<mutex> lock(mapping_mu);
 213         switch (event->type) {
 214         case SND_SEQ_EVENT_CONTROLLER: {
 215                 printf("Controller %d changed to %d\n", event->data.control.param, event->data.control.value);
 216
 217                 const int controller = event->data.control.param;
 218                 const float value = map_controller_to_float(event->data.control.value);
 219
 220                 receiver->controller_changed(controller);
 221
 222                 // Global controllers.
 223                 match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
 224                         value, bind(&ControllerReceiver::set_locut, receiver, _2));
 225                 match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
 226                         value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
 227                 match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
 228                         value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
 229
 230                 // Bus controllers.
 231                 match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
 232                         value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
 233                 match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
 234                         value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
 235                 match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
 236                         value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
 237                 match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
 238                         value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
 239                 match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
 240                         value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
 241                 match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
 242                         value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
 243                 break;
 244         }
 245         case SND_SEQ_EVENT_NOTEON: {
 246                 const int note = event->data.note.note;
 247
 248                 receiver->note_on(note);
 249
 250                 printf("Note: %d\n", note);
 251
 252                 for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 253                         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 254                         if (bus_mapping.has_prev_bank() &&
 255                             bus_mapping.prev_bank().note_number() == note) {
 256                                 current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
 257                                 update_highlights();
 258                         }
 259                         if (bus_mapping.has_next_bank() &&
 260                             bus_mapping.next_bank().note_number() == note) {
 261                                 current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
 262                                 update_highlights();
 263                         }
 264                         if (bus_mapping.has_select_bank_1() &&
 265                             bus_mapping.select_bank_1().note_number() == note) {
 266                                 current_controller_bank = 0;
 267                                 update_highlights();
 268                         }
 269                         if (bus_mapping.has_select_bank_2() &&
 270                             bus_mapping.select_bank_2().note_number() == note &&
 271                             num_controller_banks >= 2) {
 272                                 current_controller_bank = 1;
 273                                 update_highlights();
 274                         }
 275                         if (bus_mapping.has_select_bank_3() &&
 276                             bus_mapping.select_bank_3().note_number() == note &&
 277                             num_controller_banks >= 3) {
 278                                 current_controller_bank = 2;
 279                                 update_highlights();
 280                         }
 281                         if (bus_mapping.has_select_bank_4() &&
 282                             bus_mapping.select_bank_4().note_number() == note &&
 283                             num_controller_banks >= 4) {
 284                                 current_controller_bank = 3;
 285                                 update_highlights();
 286                         }
 287                         if (bus_mapping.has_select_bank_5() &&
 288                             bus_mapping.select_bank_5().note_number() == note &&
 289                             num_controller_banks >= 5) {
 290                                 current_controller_bank = 4;
 291                                 update_highlights();
 292                         }
 293                 }
 294
 295                 match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
 296                         bind(&ControllerReceiver::toggle_locut, receiver, _1));
 297                 match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
 298                         bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
 299                 match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
 300                         bind(&ControllerReceiver::toggle_compressor, receiver, _1));
 301                 match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 302                         bind(&ControllerReceiver::clear_peak, receiver, _1));
 303                 match_button(note, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber,
 304                         bind(&ControllerReceiver::toggle_limiter, receiver));
 305                 match_button(note, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber,
 306                         bind(&ControllerReceiver::toggle_auto_makeup_gain, receiver));
 307         }
 308         case SND_SEQ_EVENT_PORT_START:
 309                 subscribe_to_port(seq, event->data.addr);
 310                 break;
 311         case SND_SEQ_EVENT_PORT_EXIT:
 312                 printf("MIDI port %d:%d went away.\n", event->data.addr.client, event->data.addr.port);
 313                 break;
 314         case SND_SEQ_EVENT_NOTEOFF:
 315         case SND_SEQ_EVENT_CLIENT_START:
 316         case SND_SEQ_EVENT_CLIENT_EXIT:
 317         case SND_SEQ_EVENT_CLIENT_CHANGE:
 318         case SND_SEQ_EVENT_PORT_CHANGE:
 319         case SND_SEQ_EVENT_PORT_SUBSCRIBED:
 320         case SND_SEQ_EVENT_PORT_UNSUBSCRIBED:
 321                 break;
 322         default:
 323                 printf("Ignoring MIDI event of unknown type %d.\n", event->type);
 324         }
 325 }
 326
 327 void MIDIMapper::subscribe_to_port(snd_seq_t *seq, const snd_seq_addr_t &addr)
 328 {
 329         // Client 0 is basically the system; ignore it.
 330         if (addr.client == 0) {
 331                 return;
 332         }
 333
 334         int err = snd_seq_connect_from(seq, 0, addr.client, addr.port);
 335         if (err < 0) {
 336                 // Just print out a warning (i.e., don't die); it could
 337                 // very well just be e.g. another application.
 338                 printf("Couldn't subscribe to MIDI port %d:%d (%s).\n",
 339                         addr.client, addr.port, snd_strerror(err));
 340         } else {
 341                 printf("Subscribed to MIDI port %d:%d.\n", addr.client, addr.port);
 342         }
 343 }
 344
 345 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
 346 {
 347         if (bank_mismatch(bank_field_number)) {
 348                 return;
 349         }
 350
 351         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 352                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 353
 354                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 355                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 356                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 357                         continue;
 358                 }
 359                 const MIDIControllerProto &controller_proto =
 360                         static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 361                 if (controller_proto.controller_number() == controller) {
 362                         func(bus_idx, value);
 363                 }
 364         }
 365 }
 366
 367 void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
 368 {
 369         if (bank_mismatch(bank_field_number)) {
 370                 return;
 371         }
 372
 373         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 374                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 375
 376                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 377                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 378                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 379                         continue;
 380                 }
 381                 const MIDIButtonProto &button_proto =
 382                         static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 383                 if (button_proto.note_number() == note) {
 384                         func(bus_idx);
 385                 }
 386         }
 387 }
 388
 389 bool MIDIMapper::has_active_controller(unsigned bus_idx, int field_number, int bank_field_number)
 390 {
 391         if (bank_mismatch(bank_field_number)) {
 392                 return false;
 393         }
 394
 395         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 396         const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 397         const Reflection *bus_reflection = bus_mapping.GetReflection();
 398         return bus_reflection->HasField(bus_mapping, descriptor);
 399 }
 400
 401 bool MIDIMapper::bank_mismatch(int bank_field_number)
 402 {
 403         const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
 404         const Reflection *reflection = mapping_proto->GetReflection();
 405         return (reflection->HasField(*mapping_proto, bank_descriptor) &&
 406                 reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
 407 }
 408
 409 void MIDIMapper::refresh_highlights()
 410 {
 411         receiver->clear_all_highlights();
 412         update_highlights();
 413 }
 414
 415 void MIDIMapper::update_highlights()
 416 {
 417         // Global controllers.
 418         bool highlight_locut = false;
 419         bool highlight_limiter_threshold = false;
 420         bool highlight_makeup_gain = false;
 421         bool highlight_toggle_limiter = false;
 422         bool highlight_toggle_auto_makeup_gain = false;
 423         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 424                 if (has_active_controller(
 425                         bus_idx, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber)) {
 426                         highlight_locut = true;
 427                 }
 428                 if (has_active_controller(
 429                         bus_idx, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber)) {
 430                         highlight_limiter_threshold = true;
 431                 }
 432                 if (has_active_controller(
 433                         bus_idx, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber)) {
 434                         highlight_makeup_gain = true;
 435                 }
 436                 if (has_active_controller(
 437                         bus_idx, MIDIMappingBusProto::kToggleLimiterFieldNumber, MIDIMappingProto::kToggleLimiterBankFieldNumber)) {
 438                         highlight_toggle_limiter = true;
 439                 }
 440                 if (has_active_controller(
 441                         bus_idx, MIDIMappingBusProto::kToggleAutoMakeupGainFieldNumber, MIDIMappingProto::kToggleAutoMakeupGainBankFieldNumber)) {
 442                         highlight_toggle_auto_makeup_gain = true;
 443                 }
 444         }
 445         receiver->highlight_locut(highlight_locut);
 446         receiver->highlight_limiter_threshold(highlight_limiter_threshold);
 447         receiver->highlight_makeup_gain(highlight_makeup_gain);
 448         receiver->highlight_toggle_limiter(highlight_toggle_limiter);
 449         receiver->highlight_toggle_auto_makeup_gain(highlight_toggle_auto_makeup_gain);
 450
 451         // Per-bus controllers.
 452         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 453                 receiver->highlight_treble(bus_idx, has_active_controller(
 454                         bus_idx, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber));
 455                 receiver->highlight_mid(bus_idx, has_active_controller(
 456                         bus_idx, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber));
 457                 receiver->highlight_bass(bus_idx, has_active_controller(
 458                         bus_idx, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber));
 459                 receiver->highlight_gain(bus_idx, has_active_controller(
 460                         bus_idx, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber));
 461                 receiver->highlight_compressor_threshold(bus_idx, has_active_controller(
 462                         bus_idx, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber));
 463                 receiver->highlight_fader(bus_idx, has_active_controller(
 464                         bus_idx, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber));
 465                 receiver->highlight_toggle_locut(bus_idx, has_active_controller(
 466                         bus_idx, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber));
 467                 receiver->highlight_toggle_auto_gain_staging(bus_idx, has_active_controller(
 468                         bus_idx, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber));
 469                 receiver->highlight_toggle_compressor(bus_idx, has_active_controller(
 470                         bus_idx, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber));
 471         }
 472 }