+#include "midi_mapper.h"
+#include "midi_mapping.pb.h"
+
+#include <alsa/asoundlib.h>
+#include <google/protobuf/text_format.h>
+#include <google/protobuf/io/zero_copy_stream.h>
+#include <google/protobuf/io/zero_copy_stream_impl.h>
+#include <fcntl.h>
+#include <sys/eventfd.h>
+
+#include <functional>
+#include <thread>
+
+using namespace google::protobuf;
+using namespace std;
+using namespace std::placeholders;
+
+namespace {
+
+double map_controller_to_float(int val)
+{
+ // Slightly hackish mapping so that we can represent exactly 0.0, 0.5 and 1.0.
+ if (val <= 0) {
+ return 0.0;
+ } else if (val >= 127) {
+ return 1.0;
+ } else {
+ return (val + 0.5) / 127.0;
+ }
+}
+
+} // namespace
+
+MIDIMapper::MIDIMapper(ControllerReceiver *receiver)
+ : receiver(receiver), mapping_proto(new MIDIMappingProto)
+{
+ should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
+ assert(should_quit_fd != -1);
+}
+
+MIDIMapper::~MIDIMapper()
+{
+ should_quit = true;
+ const uint64_t one = 1;
+ write(should_quit_fd, &one, sizeof(one));
+ midi_thread.join();
+ close(should_quit_fd);
+}
+
+bool load_midi_mapping_from_file(const string &filename, MIDIMappingProto *new_mapping)
+{
+ // Read and parse the protobuf from disk.
+ int fd = open(filename.c_str(), O_RDONLY);
+ if (fd == -1) {
+ perror(filename.c_str());
+ return false;
+ }
+ io::FileInputStream input(fd); // Takes ownership of fd.
+ if (!TextFormat::Parse(&input, new_mapping)) {
+ input.Close();
+ return false;
+ }
+ input.Close();
+ return true;
+}
+
+void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
+{
+ if (mapping_proto) {
+ mapping_proto->CopyFrom(new_mapping);
+ } else {
+ mapping_proto.reset(new MIDIMappingProto(new_mapping));
+ }
+
+ num_controller_banks = min(max(mapping_proto->num_controller_banks(), 1), 5);
+ current_controller_bank = 0;
+}
+
+void MIDIMapper::start_thread()
+{
+ midi_thread = thread(&MIDIMapper::thread_func, this);
+}
+
+#define RETURN_ON_ERROR(msg, expr) do { \
+ int err = (expr); \
+ if (err < 0) { \
+ fprintf(stderr, msg ": %s\n", snd_strerror(err)); \
+ return; \
+ } \
+} while (false)
+
+
+void MIDIMapper::thread_func()
+{
+ // TODO: Listen on any port, instead of hardcoding 24:0.
+ snd_seq_t *seq;
+ int err;
+
+ RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
+ RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
+ RETURN_ON_ERROR("snd_seq_create_simple_port",
+ snd_seq_create_simple_port(seq, "nageru",
+ SND_SEQ_PORT_CAP_WRITE |
+ SND_SEQ_PORT_CAP_SUBS_WRITE,
+ SND_SEQ_PORT_TYPE_MIDI_GENERIC |
+ SND_SEQ_PORT_TYPE_APPLICATION));
+
+ snd_seq_addr_t addr;
+ RETURN_ON_ERROR("snd_seq_parse_address", snd_seq_parse_address(seq, &addr, "24:0"));
+ RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, addr.client, addr.port));
+
+ int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
+ unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
+
+ while (!should_quit) {
+ snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
+ fds[num_alsa_fds].fd = should_quit_fd;
+ fds[num_alsa_fds].events = POLLIN;
+ fds[num_alsa_fds].revents = 0;
+
+ err = poll(fds.get(), num_alsa_fds + 1, -1);
+ if (err == 0 || (err == -1 && errno == EINTR)) {
+ continue;
+ }
+ if (err == -1) {
+ perror("poll");
+ break;
+ }
+ if (fds[num_alsa_fds].revents) {
+ // Activity on should_quit_fd.
+ break;
+ }
+
+ snd_seq_event_t *event;
+ err = snd_seq_event_input(seq, &event);
+ if (event->type == SND_SEQ_EVENT_CONTROLLER) {
+ printf("Controller %d changed to %d\n", event->data.control.param, event->data.control.value);
+
+ const int controller = event->data.control.param;
+ const float value = map_controller_to_float(event->data.control.value);
+
+ match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
+ value, bind(&ControllerReceiver::set_locut, receiver, _2));
+ match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
+ value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
+ match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
+ value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
+
+ match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
+ value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
+ match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
+ value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
+ match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
+ value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
+ match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
+ value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
+ match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
+ value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
+ match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
+ value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
+ } else if (event->type == SND_SEQ_EVENT_NOTEON) {
+ const int note = event->data.note.note;
+
+ printf("Note: %d\n", note);
+
+ // Bank change commands. TODO: Highlight the bank change in the UI.
+ for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
+ const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
+ if (bus_mapping.has_prev_bank() &&
+ bus_mapping.prev_bank().note_number() == note) {
+ current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
+ }
+ if (bus_mapping.has_next_bank() &&
+ bus_mapping.next_bank().note_number() == note) {
+ current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
+ }
+ if (bus_mapping.has_select_bank_1() &&
+ bus_mapping.select_bank_1().note_number() == note) {
+ current_controller_bank = 0;
+ }
+ if (bus_mapping.has_select_bank_2() &&
+ bus_mapping.select_bank_2().note_number() == note &&
+ num_controller_banks >= 2) {
+ current_controller_bank = 1;
+ }
+ if (bus_mapping.has_select_bank_3() &&
+ bus_mapping.select_bank_3().note_number() == note &&
+ num_controller_banks >= 3) {
+ current_controller_bank = 2;
+ }
+ if (bus_mapping.has_select_bank_4() &&
+ bus_mapping.select_bank_4().note_number() == note &&
+ num_controller_banks >= 4) {
+ current_controller_bank = 3;
+ }
+ if (bus_mapping.has_select_bank_5() &&
+ bus_mapping.select_bank_5().note_number() == note &&
+ num_controller_banks >= 5) {
+ current_controller_bank = 4;
+ }
+ }
+
+ match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
+ bind(&ControllerReceiver::toggle_locut, receiver, _1));
+ match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
+ bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
+ match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
+ bind(&ControllerReceiver::toggle_compressor, receiver, _1));
+ match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
+ bind(&ControllerReceiver::clear_peak, receiver, _1));
+ } else if (event->type == SND_SEQ_EVENT_NOTEOFF) {
+ // Ignore.
+ } else {
+ printf("Ignoring MIDI event of unknown type %d.\n", event->type);
+ }
+ }
+}
+
+void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
+{
+ if (bank_mismatch(bank_field_number)) {
+ return;
+ }
+
+ for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
+ const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
+
+ const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
+ const Reflection *bus_reflection = bus_mapping.GetReflection();
+ if (!bus_reflection->HasField(bus_mapping, descriptor)) {
+ continue;
+ }
+ const MIDIControllerProto &controller_proto =
+ static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
+ if (controller_proto.controller_number() == controller) {
+ func(bus_idx, value);
+ }
+ }
+}
+
+void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
+{
+ if (bank_mismatch(bank_field_number)) {
+ return;
+ }
+
+ for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
+ const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
+
+ const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
+ const Reflection *bus_reflection = bus_mapping.GetReflection();
+ if (!bus_reflection->HasField(bus_mapping, descriptor)) {
+ continue;
+ }
+ const MIDIButtonProto &button_proto =
+ static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
+ if (button_proto.note_number() == note) {
+ func(bus_idx);
+ }
+ }
+}
+
+bool MIDIMapper::bank_mismatch(int bank_field_number)
+{
+ const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
+ const Reflection *reflection = mapping_proto->GetReflection();
+ return (reflection->HasField(*mapping_proto, bank_descriptor) &&
+ reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
+}