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 void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
  68 {
  69         if (mapping_proto) {
  70                 mapping_proto->CopyFrom(new_mapping);
  71         } else {
  72                 mapping_proto.reset(new MIDIMappingProto(new_mapping));
  73         }
  74
  75         num_controller_banks = min(max(mapping_proto->num_controller_banks(), 1), 5);
  76         current_controller_bank = 0;
  77 }
  78
  79 void MIDIMapper::start_thread()
  80 {
  81         midi_thread = thread(&MIDIMapper::thread_func, this);
  82 }
  83
  84 #define RETURN_ON_ERROR(msg, expr) do {                            \
  85         int err = (expr);                                          \
  86         if (err < 0) {                                             \
  87                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
  88                 return;                                            \
  89         }                                                          \
  90 } while (false)
  91
  92
  93 void MIDIMapper::thread_func()
  94 {
  95         // TODO: Listen on any port, instead of hardcoding 24:0.
  96         snd_seq_t *seq;
  97         int err;
  98
  99         RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
 100         RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
 101         RETURN_ON_ERROR("snd_seq_create_simple_port",
 102                 snd_seq_create_simple_port(seq, "nageru",
 103                         SND_SEQ_PORT_CAP_WRITE |
 104                         SND_SEQ_PORT_CAP_SUBS_WRITE,
 105                         SND_SEQ_PORT_TYPE_MIDI_GENERIC |
 106                         SND_SEQ_PORT_TYPE_APPLICATION));
 107
 108         snd_seq_addr_t addr;
 109         RETURN_ON_ERROR("snd_seq_parse_address", snd_seq_parse_address(seq, &addr, "24:0"));
 110         RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, addr.client, addr.port));
 111
 112         int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
 113         unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
 114
 115         while (!should_quit) {
 116                 snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
 117                 fds[num_alsa_fds].fd = should_quit_fd;
 118                 fds[num_alsa_fds].events = POLLIN;
 119                 fds[num_alsa_fds].revents = 0;
 120
 121                 err = poll(fds.get(), num_alsa_fds + 1, -1);
 122                 if (err == 0 || (err == -1 && errno == EINTR)) {
 123                         continue;
 124                 }
 125                 if (err == -1) {
 126                         perror("poll");
 127                         break;
 128                 }
 129                 if (fds[num_alsa_fds].revents) {
 130                         // Activity on should_quit_fd.
 131                         break;
 132                 }
 133
 134                 snd_seq_event_t *event;
 135                 err = snd_seq_event_input(seq, &event);
 136                 if (event->type == SND_SEQ_EVENT_CONTROLLER) {
 137                         printf("Controller %d changed to %d\n", event->data.control.param, event->data.control.value);
 138
 139                         const int controller = event->data.control.param;
 140                         const float value = map_controller_to_float(event->data.control.value);
 141
 142                         match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
 143                                 value, bind(&ControllerReceiver::set_locut, receiver, _2));
 144                         match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
 145                                 value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
 146                         match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
 147                                 value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
 148
 149                         match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
 150                                 value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
 151                         match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
 152                                 value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
 153                         match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
 154                                 value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
 155                         match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
 156                                 value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
 157                         match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
 158                                 value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
 159                         match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
 160                                 value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
 161                 } else if (event->type == SND_SEQ_EVENT_NOTEON) {
 162                         const int note = event->data.note.note;
 163
 164                         printf("Note: %d\n", note);
 165
 166                         // Bank change commands. TODO: Highlight the bank change in the UI.
 167                         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 168                                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 169                                 if (bus_mapping.has_prev_bank() &&
 170                                     bus_mapping.prev_bank().note_number() == note) {
 171                                         current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
 172                                 }
 173                                 if (bus_mapping.has_next_bank() &&
 174                                     bus_mapping.next_bank().note_number() == note) {
 175                                         current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
 176                                 }
 177                                 if (bus_mapping.has_select_bank_1() &&
 178                                     bus_mapping.select_bank_1().note_number() == note) {
 179                                         current_controller_bank = 0;
 180                                 }
 181                                 if (bus_mapping.has_select_bank_2() &&
 182                                     bus_mapping.select_bank_2().note_number() == note &&
 183                                     num_controller_banks >= 2) {
 184                                         current_controller_bank = 1;
 185                                 }
 186                                 if (bus_mapping.has_select_bank_3() &&
 187                                     bus_mapping.select_bank_3().note_number() == note &&
 188                                     num_controller_banks >= 3) {
 189                                         current_controller_bank = 2;
 190                                 }
 191                                 if (bus_mapping.has_select_bank_4() &&
 192                                     bus_mapping.select_bank_4().note_number() == note &&
 193                                     num_controller_banks >= 4) {
 194                                         current_controller_bank = 3;
 195                                 }
 196                                 if (bus_mapping.has_select_bank_5() &&
 197                                     bus_mapping.select_bank_5().note_number() == note &&
 198                                     num_controller_banks >= 5) {
 199                                         current_controller_bank = 4;
 200                                 }
 201                         }
 202
 203                         match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
 204                                 bind(&ControllerReceiver::toggle_locut, receiver, _1));
 205                         match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
 206                                 bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
 207                         match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
 208                                 bind(&ControllerReceiver::toggle_compressor, receiver, _1));
 209                         match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 210                                 bind(&ControllerReceiver::clear_peak, receiver, _1));
 211                 } else if (event->type == SND_SEQ_EVENT_NOTEOFF) {
 212                         // Ignore.
 213                 } else {
 214                         printf("Ignoring MIDI event of unknown type %d.\n", event->type);
 215                 }
 216         }
 217 }
 218
 219 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
 220 {
 221         if (bank_mismatch(bank_field_number)) {
 222                 return;
 223         }
 224
 225         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 226                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 227
 228                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 229                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 230                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 231                         continue;
 232                 }
 233                 const MIDIControllerProto &controller_proto =
 234                         static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 235                 if (controller_proto.controller_number() == controller) {
 236                         func(bus_idx, value);
 237                 }
 238         }
 239 }
 240
 241 void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
 242 {
 243         if (bank_mismatch(bank_field_number)) {
 244                 return;
 245         }
 246
 247         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 248                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 249
 250                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 251                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 252                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 253                         continue;
 254                 }
 255                 const MIDIButtonProto &button_proto =
 256                         static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 257                 if (button_proto.note_number() == note) {
 258                         func(bus_idx);
 259                 }
 260         }
 261 }
 262
 263 bool MIDIMapper::bank_mismatch(int bank_field_number)
 264 {
 265         const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
 266         const Reflection *reflection = mapping_proto->GetReflection();
 267         return (reflection->HasField(*mapping_proto, bank_descriptor) &&
 268                 reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
 269 }