MIDI backend start procedure

5 files changed, 111 insertions, 16 deletions

diff --git a/artnet.c b/artnet.c
index 6eef2fe..598fed8 100644
--- a/artnet.c
+++ b/artnet.c
@@ -104,7 +104,7 @@ static channel* artnet_channel(instance* instance, char* spec){
 		fprintf(stderr, "Invalid ArtNet channel %s\n", spec);
 		return NULL;
 	}
-	return mm_channel(instance, channel);
+	return mm_channel(instance, channel, 1);
 }
 
 static int artnet_set(size_t num, channel* c, channel_value* v){
diff --git a/backend.c b/backend.c
index f49bd91..2eb6fcf 100644
--- a/backend.c
+++ b/backend.c
@@ -9,7 +9,7 @@ static instance** instances = NULL;
 static size_t nchannels = 0;
 static channel** channels = NULL;
 
-channel* mm_channel(instance* i, uint64_t ident){
+channel* mm_channel(instance* i, uint64_t ident, uint8_t create){
 	size_t u;
 	for(u = 0; u < nchannels; u++){
 		if(channels[u]->instance == 0 && channels[u]->ident == ident){
@@ -17,6 +17,10 @@ channel* mm_channel(instance* i, uint64_t ident){
 		}
 	}
 
+	if(!create){
+		return NULL;
+	}
+
 	channel** new_chan = realloc(channels, (nchannels + 1) * sizeof(channel*));
 	if(!new_chan){
 		fprintf(stderr, "Failed to allocate memory\n");
diff --git a/midi.c b/midi.c
index 00ff0a4..ca1f66b 100644
--- a/midi.c
+++ b/midi.c
@@ -40,6 +40,10 @@ int midi_init(){
 		fprintf(stderr, "Failed to register MIDI backend\n");
 		return 1;
 	}
+
+	snd_seq_nonblock(sequencer, 1);		
+		
+	fprintf(stderr, "MIDI client ID is %d\n", snd_seq_client_id(sequencer));
 	return 0;
 }
 
@@ -57,24 +61,43 @@ static int midi_configure(char* option, char* value){
 }
 
 static instance* midi_instance(){
-	return mm_instance();
+	instance* inst = mm_instance();
+	if(!inst){
+		return NULL;
+	}
+
+	inst->impl = calloc(1, sizeof(midi_instance_data));
+	if(!inst->impl){
+		fprintf(stderr, "Failed to allocate memory\n");
+		return NULL;
+	}
+
+	return inst;
 }
 
 static int midi_configure_instance(instance* instance, char* option, char* value){
-	if(!strcmp(option, "device")){
-		//open i/o device
-		return 0;
-	}
-	else if(!strcmp(option, "port")){
-		//create midi port
+	midi_instance_data* data = (midi_instance_data*) instance->impl;
+
+	//FIXME maybe allow connecting more than one device
+	if(!strcmp(option, "read")){
+		//connect input device
+		if(data->read){
+			fprintf(stderr, "Port already connected to an input device\n");
+			return 1;
+		}
+		data->read = strdup(value);
 		return 0;
 	}
-	else if(!strcmp(option, "mode")){
-		//configure open mode
-		//FIXME needed?
+	else if(!strcmp(option, "write")){
+		//connect output device
+		if(data->write){
+			fprintf(stderr, "Port already connected to an output device\n");
+			return 1;
+		}
+		data->write = strdup(value);
 		return 0;
 	}
-	
+
 	fprintf(stderr, "Unknown MIDI instance option %s\n", option);
 	return 1;
 }
@@ -124,7 +147,7 @@ static channel* midi_channel(instance* instance, char* spec){
 	ident.fields.control = strtoul(channel, NULL, 10);
 
 	if(ident.label){
-		return mm_channel(instance, ident.label);
+		return mm_channel(instance, ident.label, 1);
 	}
 
 	return NULL;
@@ -141,7 +164,69 @@ static int midi_handle(size_t num, int* fd, void** data){
 }
 
 static int midi_start(){
-	return 0;
+	size_t n, p;
+	int nfds, rv = 1;
+	struct pollfd* pfds = NULL;
+	instance** inst = NULL;
+	midi_instance_data* data = NULL;
+	snd_seq_addr_t addr;
+
+	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
+		fprintf(stderr, "Failed to fetch instance list\n");
+		return 1;
+	}
+
+	//create all ports
+	for(p = 0; p < n; p++){
+		data = (midi_instance_data*) inst[p]->impl;
+		data->port = snd_seq_create_simple_port(sequencer, inst[p]->name, SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE | SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ, SND_SEQ_PORT_TYPE_MIDI_GENERIC);
+
+		//make connections
+		if(data->write){
+			fprintf(stderr, "Connecting output of instance %s to MIDI device %s\n", inst[p]->name, data->write);
+			if(snd_seq_parse_address(sequencer, &addr, data->write) == 0){
+				snd_seq_connect_to(sequencer, data->port, addr.client, addr.port);
+			}
+			else{
+				fprintf(stderr, "Failed to get destination device address: %s\n", data->write);
+			}
+			free(data->write);
+			data->write = NULL;
+		}
+
+		if(data->read){
+			fprintf(stderr, "Connecting input from MIDI device %s to instance %s\n", data->read, inst[p]->name);
+			if(snd_seq_parse_address(sequencer, &addr, data->read) == 0){
+				snd_seq_connect_from(sequencer, data->port, addr.client, addr.port);
+			}
+			else{
+				fprintf(stderr, "Failed to get source device address: %s\n", data->read);
+			}
+			free(data->read);
+			data->read = NULL;
+		}
+	}
+
+	//register all fds to core
+	nfds = snd_seq_poll_descriptors_count(sequencer, POLLIN | POLLOUT);	
+	pfds = calloc(nfds, sizeof(struct pollfd));
+	if(!pfds){
+		fprintf(stderr, "Failed to allocate memory\n");
+		goto bail;
+	}
+	nfds = snd_seq_poll_descriptors(sequencer, pfds, nfds, POLLIN | POLLOUT);	
+
+	fprintf(stderr, "Registering %d descriptors to core\n", nfds);
+	for(p = 0; p < nfds; p++){
+		mm_manage_fd(pfds[p].fd, BACKEND_NAME, 1, NULL);
+	}
+
+	rv = 0;
+
+bail:
+	free(pfds);
+	free(inst);
+	return rv;
 }
 
 static int midi_shutdown(){
diff --git a/midi.h b/midi.h
index c83345b..7a13f7c 100644
--- a/midi.h
+++ b/midi.h
@@ -9,3 +9,9 @@ static int midi_set(size_t num, channel* c, channel_value* v);
 static int midi_handle(size_t num, int* fd, void** data);
 static int midi_start();
 static int midi_shutdown();
+
+typedef struct /*_midi_instance_data*/ {
+	int port;
+	char* read;
+	char* write;
+} midi_instance_data;
diff --git a/midimonster.h b/midimonster.h
index 181f1da..d548528 100644
--- a/midimonster.h
+++ b/midimonster.h
@@ -98,7 +98,7 @@ instance* mm_instance();
  * For each channel with a non-NULL impl field, the backend
  * will receive a call to its channel_free function.
  */
-channel* mm_channel(instance* i, uint64_t ident);
+channel* mm_channel(instance* i, uint64_t ident, uint8_t create);
 /*
  * Register a file descriptor to be selected on. The backend
  * will be notified via the mmbackend_process_fd call.