Add readme, flesh out backends

10 files changed, 319 insertions, 45 deletions

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..83b6f52
--- /dev/null
+++ b/README.md
@@ -0,0 +1,67 @@
+# The MIDIMonster
+
+Named for it's scary math, the MIDIMonster is a universal translation
+tool between multi-channel absolute-value-based control and/or bus protocols,
+such as MIDI, DMX/ArtNet and OSC.
+
+It allows the user to translate channels on one protocol into channels on another
+(or the same) protocol, eg
+
+* Translate MIDI Control Changes into Notes
+* Translate MIDI Notes into ArtNet
+* Translate OSC messages into MIDI
+
+## Configuration
+
+Each protocol supported by MIDIMonster is implemented by a *backend*, which takes
+global protocol-specific options and provides *instance*s, which can be configured further.
+
+The configuration is stored in a file with a format very similar to the common
+INI file format. A section is started by a header in `[]` braces, followed by
+lines of the form `option = value`.
+
+A section may either be a *backend configuration* section, started by `[backend <backend-name>]`,
+an *instance configuration* section, started by `[<backend-name> <instance-name>]` or a *mapping*
+section started by `[map]`.
+
+The options accepted by the implemented backends are documented in the next section.
+
+### The `artnet` backend
+
+#### Global configuration
+
+| Option	| Example value		| Default value 	| Description		|
+|---------------|-----------------------|-----------------------|-----------------------|
+| `bind`	| `127.0.0.1 6454`	| *none*		| What address and port to bind the ArtNet socket to |
+| `net`		| `0`			| `0`			| The default net to use |
+
+#### Instance configuration
+
+### The `midi` backend
+
+#### Global configuration
+
+#### Instance configuration
+
+### The `osc` backend
+
+#### Global configuration
+
+#### Instance configuration
+
+## Building
+
+This section will explain how to build the provided sources to be able to run
+`midimonster`.
+
+### Prerequisites
+
+In order to build the MIDIMonster, you'll need some libraries that provide
+support for the protocols to translate.
+
+* libasound2-dev
+* A C compiler
+
+### Building
+
+Just running `make` in the source directory should do the trick.
diff --git a/artnet.c b/artnet.c
index a245cf1..a1f52d7 100644
--- a/artnet.c
+++ b/artnet.c
@@ -1,12 +1,12 @@
 #include <string.h>
 #include "artnet.h"
 
-size_t ninstances = 0;
-instance* instances = NULL;
+#define BACKEND_NAME "artnet"
+static uint8_t default_net = 0;
 
 int artnet_init(){
 	backend artnet = {
-		.name = "artnet",
+		.name = BACKEND_NAME,
 		.conf = artnet_configure,
 		.create = artnet_instance,
 		.conf_instance = artnet_configure_instance,
@@ -17,7 +17,7 @@ int artnet_init(){
 	};
 
 	//register backend
-	if(!mm_backend_register(artnet)){
+	if(mm_backend_register(artnet)){
 		fprintf(stderr, "Failed to register ArtNet backend\n");
 		return 1;
 	}
@@ -25,50 +25,78 @@ int artnet_init(){
 }
 
 static int artnet_configure(char* option, char* value){
-	fprintf(stderr, "ArtNet backend configured: %s -> %s\n", option, value);
-	return 0;
+	if(!strcmp(option, "bind")){
+		//TODO create socket, hand over to be managed (unregister previous socket?)
+		return 0;
+	}
+	else if(!strcmp(option, "net")){
+		//configure default net
+		default_net = strtoul(value, NULL, 10);
+		return 0;
+	}
+	fprintf(stderr, "Unknown ArtNet backend option %s\n", option);
+	return 1;
 }
 
 static instance* artnet_instance(){
-	fprintf(stderr, "Creating new ArtNet instance\n");
-	instances = realloc(instances, (ninstances + 1) * sizeof(instance));
-	if(!instances){
+	instance* inst = mm_instance();
+	if(!inst){
+		return NULL;
+	}
+
+	inst->impl = calloc(1, sizeof(artnet_instance_data));
+	if(!inst->impl){
 		fprintf(stderr, "Failed to allocate memory\n");
-		ninstances = 0;
 		return NULL;
 	}
-	memset(instances + ninstances, 0, sizeof(instance));
-	ninstances++;
-	return instances + (ninstances - 1);
+
+	return inst;
 }
 
 static int artnet_configure_instance(instance* instance, char* option, char* value){
-	fprintf(stderr, "ArtNet instance configured: %s -> %s\n", option, value);
+	artnet_instance_data* data = (artnet_instance_data*) instance->impl;
+
+	if(!strcmp(option, "net")){
+		data->net = strtoul(value, NULL, 10);
+		return 0;
+	}
+	else if(!strcmp(option, "uni")){
+		data->uni = strtoul(value, NULL, 10);
+		return 0;
+	}
+
+	fprintf(stderr, "Unknown ArtNet instance option %s\n", option);
 	return 1;
 }
 
 static channel* artnet_channel(instance* instance, char* spec){
 	fprintf(stderr, "Parsing ArtNet channelspec %s\n", spec);
+	//TODO
 	return NULL;
 }
 
 static int artnet_set(size_t num, channel* c, channel_value* v){
+	//TODO
 	return 1;
 }
 
 static int artnet_handle(size_t num, int* fd, void** data){
+	//TODO
 	return 1;
 }
 
 static int artnet_shutdown(){
-	size_t u;
-
-	for(u = 0; u < ninstances; u++){
-		mm_instance_free(instances + u);
+	size_t n, p;
+	instance** inst = NULL;
+	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
+		fprintf(stderr, "Failed to fetch instance list\n");
+		return 1;
 	}
-	free(instances);
-	ninstances = 0;
 
+	for(p = 0; p < n; p++){
+		free(inst[p]->impl);
+	}
+	free(inst);
 	fprintf(stderr, "ArtNet backend shut down\n");
 	return 0;
 }
diff --git a/artnet.h b/artnet.h
index a7742f3..03106bf 100644
--- a/artnet.h
+++ b/artnet.h
@@ -8,3 +8,8 @@ static channel* artnet_channel(instance* instance, char* spec);
 static int artnet_set(size_t num, channel* c, channel_value* v);
 static int artnet_handle(size_t num, int* fd, void** data);
 static int artnet_shutdown();
+
+typedef struct /*_artnet_instance_model*/ {
+	uint8_t net;
+	uint8_t uni;
+} artnet_instance_data;
diff --git a/backend.c b/backend.c
index e1e143f..673fe9b 100644
--- a/backend.c
+++ b/backend.c
@@ -15,21 +15,21 @@ backend* backend_match(char* name){
 	return NULL;
 }
 
-backend* mm_backend_register(backend b){
+int mm_backend_register(backend b){
 	if(!backend_match(b.name)){
 		backends = realloc(backends, (nbackends + 1) * sizeof(backend));
 		if(!backends){
 			fprintf(stderr, "Failed to allocate memory\n");
 			nbackends = 0;
-			return NULL;
+			return 1;
 		}
 		backends[nbackends] = b;
 		nbackends++;
 
 		fprintf(stderr, "Registered backend %s\n", b.name);
-		return backends + (nbackends - 1);
+		return 0;
 	}
-	return NULL;
+	return 1;
 }
 
 int backends_stop(){
diff --git a/config.c b/config.c
index de6767d..b87394f 100644
--- a/config.c
+++ b/config.c
@@ -130,9 +130,3 @@ bail:
 	free(line_raw);
 	return rv;
 }
-
-void mm_instance_free(instance* inst){
-	free(inst->name);
-	inst->name = NULL;
-	inst->backend = NULL;
-}
diff --git a/midi.c b/midi.c
index c817bd2..a59ebeb 100644
--- a/midi.c
+++ b/midi.c
@@ -1,3 +1,107 @@
-int midi_start(){
+#include <string.h>
+#include <alsa/asoundlib.h>
+#include "midi.h"
+
+#define BACKEND_NAME "midi"
+static snd_seq_t* sequencer = NULL;
+
+int midi_init(){
+	backend midi = {
+		.name = BACKEND_NAME,
+		.conf = midi_configure,
+		.create = midi_instance,
+		.conf_instance = midi_configure_instance,
+		.channel = midi_channel,
+		.handle = midi_set,
+		.process = midi_handle,
+		.shutdown = midi_shutdown
+	};
+
+	if(snd_seq_open(&sequencer, "default", SND_SEQ_OPEN_DUPLEX, 0) < 0){
+		fprintf(stderr, "Failed to open ALSA sequencer\n");
+		return 1;
+	}
+
+	//register backend
+	if(mm_backend_register(midi)){
+		fprintf(stderr, "Failed to register MIDI backend\n");
+		return 1;
+	}
+	return 0;
+}
+
+static int midi_configure(char* option, char* value){
+	if(!strcmp(option, "name")){
+		if(snd_seq_set_client_name(sequencer, value) < 0){
+			fprintf(stderr, "Failed to set MIDI client name to %s\n", value);
+			return 1;
+		}
+		return 0;
+	}
+
+	fprintf(stderr, "Unknown MIDI backend option %s\n", option);
+	return 1;
+}
+
+static instance* midi_instance(){
+	return mm_instance();
+}
+
+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
+		return 0;
+	}
+	else if(!strcmp(option, "mode")){
+		//configure open mode
+		//FIXME needed?
+		return 0;
+	}
+	
+	fprintf(stderr, "Unknown MIDI instance option %s\n", option);
+	return 1;
+}
+
+static channel* midi_channel(instance* instance, char* spec){
+	fprintf(stderr, "Parsing MIDI channelspec %s\n", spec);
+	//TODO
+	return NULL;
+}
+
+static int midi_set(size_t num, channel* c, channel_value* v){
+	//TODO
 	return 1;
 }
+
+static int midi_handle(size_t num, int* fd, void** data){
+	//TODO
+	return 1;
+}
+
+static int midi_shutdown(){
+	size_t n, p;
+	instance** inst = NULL;
+	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
+		fprintf(stderr, "Failed to fetch instance list\n");
+		return 1;
+	}
+
+	for(p = 0; p < n; p++){
+		free(inst[p]->impl);
+	}
+	free(inst);
+
+	//close midi
+	snd_seq_close(sequencer);
+	sequencer = NULL;
+
+	//free configuration cache
+	snd_config_update_free_global();
+
+	fprintf(stderr, "MIDI backend shut down\n");
+	return 0;
+}
diff --git a/midi.h b/midi.h
index eef2413..abad971 100644
--- a/midi.h
+++ b/midi.h
@@ -1,2 +1,10 @@
 #include "midimonster.h"
-int midi_start();
+
+int midi_init();
+static int midi_configure(char* option, char* value);
+static int midi_configure_instance(instance* instance, char* option, char* value);
+static instance* midi_instance();
+static channel* midi_channel(instance* instance, char* spec);
+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_shutdown();
diff --git a/midimonster.c b/midimonster.c
index 5d7ec7f..765c1ce 100644
--- a/midimonster.c
+++ b/midimonster.c
@@ -1,3 +1,4 @@
+#include <string.h>
 #include "midimonster.h"
 #include "config.h"
 #include "backend.h"
@@ -7,6 +8,67 @@ int artnet_init();
 int midi_init();
 int osc_init();
 
+static size_t ninstances = 0;
+static instance** instances = NULL;
+
+instance* mm_instance(){
+	instance** new_inst = realloc(instances, (ninstances + 1) * sizeof(instance*));
+	if(!new_inst){
+		//TODO free
+		fprintf(stderr, "Failed to allocate memory\n");
+		ninstances = 0;
+		return NULL;
+	}
+	instances = new_inst;
+	instances[ninstances] = calloc(1, sizeof(instance));
+	if(!instances[ninstances]){
+		fprintf(stderr, "Failed to allocate memory\n");
+		return NULL;
+	}
+
+	return instances[ninstances++];
+}
+
+int mm_backend_instances(char* name, size_t* ninst, instance*** inst){
+	backend* b = backend_match(name);
+	size_t n = 0, u;
+	//count number of affected instances
+	for(u = 0; u < ninstances; u++){
+		if(instances[u]->backend == b){
+			n++;
+		}
+	}
+
+	*ninst = n;
+	*inst = calloc(n, sizeof(instance*));
+	if(!*inst){
+		fprintf(stderr, "Failed to allocate memory\n");
+		return 1;
+	}
+
+	n = 0;
+	for(u = 0; u < ninstances; u++){
+		if(instances[u]->backend == b){
+			(*inst)[n] = instances[u];
+			n++;
+		}
+	}
+	return 0;
+}
+
+static void instances_free(){
+	size_t u;
+	for(u = 0; u < ninstances; u++){
+		free(instances[u]->name);
+		instances[u]->name = NULL;
+		instances[u]->backend = NULL;
+		free(instances[u]);
+		instances[u] = NULL;
+	}
+	free(instances);
+	ninstances = 0;
+}
+
 int usage(char* fn){
 	fprintf(stderr, "MIDIMonster v0.1\n");
 	fprintf(stderr, "Usage:\n");
@@ -23,7 +85,7 @@ int main(int argc, char** argv){
 
 	//initialize backends
 	//TODO replace this with loading shared objects
-	if(artnet_init() /*|| midi_init() || osc_init()*/){
+	if(artnet_init() || midi_init() /* || osc_init()*/){
 		fprintf(stderr, "Failed to initialize a backend\n");
 		goto bail;
 	}
@@ -32,6 +94,7 @@ int main(int argc, char** argv){
 	if(config_read(cfg_file)){
 		fprintf(stderr, "Failed to read configuration file %s\n", cfg_file);
 		backends_stop();
+		instances_free();
 		return usage(argv[0]);
 	}
 
@@ -41,6 +104,7 @@ int main(int argc, char** argv){
 bail:
 	//free all data
 	backends_stop();
+	instances_free();
 
 	return rv;
 }
diff --git a/midimonster.h b/midimonster.h
index 8c323f1..86c2d30 100644
--- a/midimonster.h
+++ b/midimonster.h
@@ -55,9 +55,9 @@ typedef struct /*_mm_managed_fd*/ {
 	void* impl;
 } managed_fd;
 
-backend* mm_backend_register(backend b);
-int mm_manage_fd(int fd, backend* b, int manage, void* impl);
+int mm_backend_register(backend b);
+instance* mm_instance();
+int mm_manage_fd(int fd, char* backend, int manage, void* impl);
 int mm_channel_event(channel* c, channel_value v);
-
-void mm_instance_free(instance* i);
+int mm_backend_instances(char* backend, size_t* n, instance*** i);
 #endif
diff --git a/monster.cfg b/monster.cfg
index 8d3b0ad..ccb0d11 100644
--- a/monster.cfg
+++ b/monster.cfg
@@ -2,26 +2,30 @@
 name = MIDIMonster
 
 [backend artnet]
+bind = 127.0.0.1 6454
+net = 0
 
-[backend osc]
+;[backend osc]
 
 [midi indisc]
-name = MIDIMonster Input 1
-mode = input,output,create
+port = MIDIMonster Input 1
+;mode = input,output,create
 
 [midi lc1]
 device = 20:0
-mode = input,output
+;mode = input,output
 
 [midi xlate]
-name = Translation Output 1
-mode = input,output,create
+port = Translation Output 1
+;mode = input,output,create
 
 [artnet net1]
-mode = input,output
-net = 0
+net = 1
 uni = 1
 
+[artnet foo]
+net = 0
+
 [map]
 artnet.231 = lc1.cc5
 artent.231 = osc.f/channel5/ toggle=127