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 }
  40
  41 MIDIMapper::~MIDIMapper()
  42 {
  43         should_quit = true;
  44         const uint64_t one = 1;
  45         write(should_quit_fd, &one, sizeof(one));
  46         midi_thread.join();
  47         close(should_quit_fd);
  48 }
  49
  50 bool load_midi_mapping_from_file(const string &filename, MIDIMappingProto *new_mapping)
  51 {
  52         // Read and parse the protobuf from disk.
  53         int fd = open(filename.c_str(), O_RDONLY);
  54         if (fd == -1) {
  55                 perror(filename.c_str());
  56                 return false;
  57         }
  58         io::FileInputStream input(fd);  // Takes ownership of fd.
  59         if (!TextFormat::Parse(&input, new_mapping)) {
  60                 input.Close();
  61                 return false;
  62         }
  63         input.Close();
  64         return true;
  65 }
  66
  67 bool save_midi_mapping_to_file(const MIDIMappingProto &mapping_proto, const string &filename)
  68 {
  69         // Save to disk. We use the text format because it's friendlier
  70         // for a user to look at and edit.
  71         int fd = open(filename.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
  72         if (fd == -1) {
  73                 perror(filename.c_str());
  74                 return false;
  75         }
  76         io::FileOutputStream output(fd);  // Takes ownership of fd.
  77         if (!TextFormat::Print(mapping_proto, &output)) {
  78                 // TODO: Don't overwrite the old file (if any) on error.
  79                 output.Close();
  80                 return false;
  81         }
  82
  83         output.Close();
  84         return true;
  85 }
  86
  87 void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
  88 {
  89         lock_guard<mutex> lock(mapping_mu);
  90         if (mapping_proto) {
  91                 mapping_proto->CopyFrom(new_mapping);
  92         } else {
  93                 mapping_proto.reset(new MIDIMappingProto(new_mapping));
  94         }
  95
  96         num_controller_banks = min(max(mapping_proto->num_controller_banks(), 1), 5);
  97         current_controller_bank = 0;
  98 }
  99
 100 void MIDIMapper::start_thread()
 101 {
 102         midi_thread = thread(&MIDIMapper::thread_func, this);
 103 }
 104
 105 const MIDIMappingProto &MIDIMapper::get_current_mapping() const
 106 {
 107         lock_guard<mutex> lock(mapping_mu);
 108         return *mapping_proto;
 109 }
 110
 111 #define RETURN_ON_ERROR(msg, expr) do {                            \
 112         int err = (expr);                                          \
 113         if (err < 0) {                                             \
 114                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
 115                 return;                                            \
 116         }                                                          \
 117 } while (false)
 118
 119
 120 void MIDIMapper::thread_func()
 121 {
 122         snd_seq_t *seq;
 123         int err;
 124
 125         RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
 126         RETURN_ON_ERROR("snd_seq_nonblock", snd_seq_nonblock(seq, 1));
 127         RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
 128         RETURN_ON_ERROR("snd_seq_create_simple_port",
 129                 snd_seq_create_simple_port(seq, "nageru",
 130                         SND_SEQ_PORT_CAP_WRITE |
 131                         SND_SEQ_PORT_CAP_SUBS_WRITE,
 132                         SND_SEQ_PORT_TYPE_MIDI_GENERIC |
 133                         SND_SEQ_PORT_TYPE_APPLICATION));
 134
 135         // Listen to the announce port (0:1), which will tell us about new ports.
 136         RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, /*client=*/0, /*port=*/1));
 137
 138         // Now go through all ports and subscribe to them.
 139         snd_seq_client_info_t *cinfo;
 140         snd_seq_client_info_alloca(&cinfo);
 141
 142         snd_seq_client_info_set_client(cinfo, -1);
 143         while (snd_seq_query_next_client(seq, cinfo) >= 0) {
 144                 int client = snd_seq_client_info_get_client(cinfo);
 145
 146                 snd_seq_port_info_t *pinfo;
 147                 snd_seq_port_info_alloca(&pinfo);
 148
 149                 snd_seq_port_info_set_client(pinfo, client);
 150                 snd_seq_port_info_set_port(pinfo, -1);
 151                 while (snd_seq_query_next_port(seq, pinfo) >= 0) {
 152                         constexpr int mask = SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ;
 153                         if ((snd_seq_port_info_get_capability(pinfo) & mask) == mask) {
 154                                 subscribe_to_port(seq, *snd_seq_port_info_get_addr(pinfo));
 155                         }
 156                 }
 157         }
 158
 159         int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
 160         unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
 161
 162         while (!should_quit) {
 163                 snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
 164                 fds[num_alsa_fds].fd = should_quit_fd;
 165                 fds[num_alsa_fds].events = POLLIN;
 166                 fds[num_alsa_fds].revents = 0;
 167
 168                 err = poll(fds.get(), num_alsa_fds + 1, -1);
 169                 if (err == 0 || (err == -1 && errno == EINTR)) {
 170                         continue;
 171                 }
 172                 if (err == -1) {
 173                         perror("poll");
 174                         break;
 175                 }
 176                 if (fds[num_alsa_fds].revents) {
 177                         // Activity on should_quit_fd.
 178                         break;
 179                 }
 180
 181                 // Seemingly we can get multiple events in a single poll,
 182                 // and if we don't handle them all, poll will _not_ alert us!
 183                 while (!should_quit) {
 184                         snd_seq_event_t *event;
 185                         err = snd_seq_event_input(seq, &event);
 186                         if (err < 0) {
 187                                 if (err == -EINTR) continue;
 188                                 if (err == -EAGAIN) break;
 189                                 fprintf(stderr, "snd_seq_event_input: %s\n", snd_strerror(err));
 190                                 return;
 191                         }
 192                         if (event) {
 193                                 handle_event(seq, event);
 194                         }
 195                 }
 196         }
 197 }
 198
 199 void MIDIMapper::handle_event(snd_seq_t *seq, snd_seq_event_t *event)
 200 {
 201         lock_guard<mutex> lock(mapping_mu);
 202         switch (event->type) {
 203         case SND_SEQ_EVENT_CONTROLLER: {
 204                 printf("Controller %d changed to %d\n", event->data.control.param, event->data.control.value);
 205
 206                 const int controller = event->data.control.param;
 207                 const float value = map_controller_to_float(event->data.control.value);
 208
 209                 // Global controllers.
 210                 match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
 211                         value, bind(&ControllerReceiver::set_locut, receiver, _2));
 212                 match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
 213                         value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
 214                 match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
 215                         value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
 216
 217                 // Bus controllers.
 218                 match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
 219                         value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
 220                 match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
 221                         value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
 222                 match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
 223                         value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
 224                 match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
 225                         value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
 226                 match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
 227                         value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
 228                 match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
 229                         value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
 230                 break;
 231         }
 232         case SND_SEQ_EVENT_NOTEON: {
 233                 const int note = event->data.note.note;
 234
 235                 printf("Note: %d\n", note);
 236
 237                 // Bank change commands. TODO: Highlight the bank change in the UI.
 238                 for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 239                         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 240                         if (bus_mapping.has_prev_bank() &&
 241                             bus_mapping.prev_bank().note_number() == note) {
 242                                 current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
 243                         }
 244                         if (bus_mapping.has_next_bank() &&
 245                             bus_mapping.next_bank().note_number() == note) {
 246                                 current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
 247                         }
 248                         if (bus_mapping.has_select_bank_1() &&
 249                             bus_mapping.select_bank_1().note_number() == note) {
 250                                 current_controller_bank = 0;
 251                         }
 252                         if (bus_mapping.has_select_bank_2() &&
 253                             bus_mapping.select_bank_2().note_number() == note &&
 254                             num_controller_banks >= 2) {
 255                                 current_controller_bank = 1;
 256                         }
 257                         if (bus_mapping.has_select_bank_3() &&
 258                             bus_mapping.select_bank_3().note_number() == note &&
 259                             num_controller_banks >= 3) {
 260                                 current_controller_bank = 2;
 261                         }
 262                         if (bus_mapping.has_select_bank_4() &&
 263                             bus_mapping.select_bank_4().note_number() == note &&
 264                             num_controller_banks >= 4) {
 265                                 current_controller_bank = 3;
 266                         }
 267                         if (bus_mapping.has_select_bank_5() &&
 268                             bus_mapping.select_bank_5().note_number() == note &&
 269                             num_controller_banks >= 5) {
 270                                 current_controller_bank = 4;
 271                         }
 272                 }
 273
 274                 match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
 275                         bind(&ControllerReceiver::toggle_locut, receiver, _1));
 276                 match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
 277                         bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
 278                 match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
 279                         bind(&ControllerReceiver::toggle_compressor, receiver, _1));
 280                 match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 281                         bind(&ControllerReceiver::clear_peak, receiver, _1));
 282         }
 283         case SND_SEQ_EVENT_PORT_START:
 284                 subscribe_to_port(seq, event->data.addr);
 285                 break;
 286         case SND_SEQ_EVENT_PORT_EXIT:
 287                 printf("MIDI port %d:%d went away.\n", event->data.addr.client, event->data.addr.port);
 288                 break;
 289         case SND_SEQ_EVENT_NOTEOFF:
 290         case SND_SEQ_EVENT_CLIENT_START:
 291         case SND_SEQ_EVENT_CLIENT_EXIT:
 292         case SND_SEQ_EVENT_CLIENT_CHANGE:
 293         case SND_SEQ_EVENT_PORT_CHANGE:
 294         case SND_SEQ_EVENT_PORT_SUBSCRIBED:
 295         case SND_SEQ_EVENT_PORT_UNSUBSCRIBED:
 296                 break;
 297         default:
 298                 printf("Ignoring MIDI event of unknown type %d.\n", event->type);
 299         }
 300 }
 301
 302 void MIDIMapper::subscribe_to_port(snd_seq_t *seq, const snd_seq_addr_t &addr)
 303 {
 304         // Client 0 is basically the system; ignore it.
 305         if (addr.client == 0) {
 306                 return;
 307         }
 308
 309         int err = snd_seq_connect_from(seq, 0, addr.client, addr.port);
 310         if (err < 0) {
 311                 // Just print out a warning (i.e., don't die); it could
 312                 // very well just be e.g. another application.
 313                 printf("Couldn't subscribe to MIDI port %d:%d (%s).\n",
 314                         addr.client, addr.port, snd_strerror(err));
 315         } else {
 316                 printf("Subscribed to MIDI port %d:%d.\n", addr.client, addr.port);
 317         }
 318 }
 319
 320 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
 321 {
 322         if (bank_mismatch(bank_field_number)) {
 323                 return;
 324         }
 325
 326         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 327                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 328
 329                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 330                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 331                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 332                         continue;
 333                 }
 334                 const MIDIControllerProto &controller_proto =
 335                         static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 336                 if (controller_proto.controller_number() == controller) {
 337                         func(bus_idx, value);
 338                 }
 339         }
 340 }
 341
 342 void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
 343 {
 344         if (bank_mismatch(bank_field_number)) {
 345                 return;
 346         }
 347
 348         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 349                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 350
 351                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 352                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 353                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 354                         continue;
 355                 }
 356                 const MIDIButtonProto &button_proto =
 357                         static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 358                 if (button_proto.note_number() == note) {
 359                         func(bus_idx);
 360                 }
 361         }
 362 }
 363
 364 bool MIDIMapper::bank_mismatch(int bank_field_number)
 365 {
 366         const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
 367         const Reflection *reflection = mapping_proto->GetReflection();
 368         return (reflection->HasField(*mapping_proto, bank_descriptor) &&
 369                 reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
 370 }