Added an ALSA sequencer support. Updated readme.txt to explain it, and

Makefile to allow the user to enable it. I also reorganised the Makefile
a bit, since there is now one more optionnal library. BBrox, I also
merged your Makefile.x11 in it, just take a look at it!

svn-id: r4341

1 files changed, 200 insertions, 0 deletions

diff --git a/sound/mididrv.cpp b/sound/mididrv.cpp
index 0dc14f9558..4dfda237e6 100644
--- a/sound/mididrv.cpp
+++ b/sound/mididrv.cpp
@@ -1444,6 +1444,205 @@ void MidiDriver_MIDIEMU::midi_fm_endnote(int voice) {
 }
 
 
+#if defined(UNIX) && defined(USE_ALSA)
+
+#include <alsa/asoundlib.h>
+
+/*
+ *     ALSA sequencer driver
+ * Mostly cut'n'pasted from Virtual Tiny Keyboard (vkeybd) by Takashi Iwai
+ *                                      (you really rox, you know?)
+ */
+
+#if SND_LIB_MINOR >= 6
+#define snd_seq_flush_output(x) snd_seq_drain_output(x)
+#define snd_seq_set_client_group(x,name) /*nop*/
+#define my_snd_seq_open(seqp) snd_seq_open(seqp, "hw", SND_SEQ_OPEN_OUTPUT, 0)
+#else
+/* SND_SEQ_OPEN_OUT causes oops on early version of ALSA */
+#define my_snd_seq_open(seqp) snd_seq_open(seqp, SND_SEQ_OPEN)
+#endif
+
+/*
+ * parse address string
+ */
+
+#define ADDR_DELIM      ".:"
+
+static int parse_addr(char *arg, int *client, int *port)
+{
+        char *p;
+
+        if (isdigit(*arg)) {
+                if ((p = strpbrk(arg, ADDR_DELIM)) == NULL)
+                        return -1;
+                *client = atoi(arg);
+                *port = atoi(p + 1);
+        } else {
+                if (*arg == 's' || *arg == 'S') {
+                        *client = SND_SEQ_ADDRESS_SUBSCRIBERS;
+                        *port = 0;
+                } else
+                        return -1;
+        }
+        return 0;
+}
+
+class MidiDriver_ALSA : public MidiDriver {
+public:
+        MidiDriver_ALSA();
+	int open(int mode);
+	void close();
+	void send(uint32 b);
+	void pause(bool pause);
+	void set_stream_callback(void *param, StreamCallback *sc);
+
+private:
+	void send_event(int do_flush);
+        snd_seq_event_t ev;
+	StreamCallback *_stream_proc;
+	void  *_stream_param;
+	int 	 _mode;
+	snd_seq_t *seq_handle;
+	int seq_client, seq_port;
+	int my_client, my_port;
+};
+
+MidiDriver_ALSA::MidiDriver_ALSA() {
+    printf("Driver: ALSA\n");
+}
+
+void MidiDriver_ALSA::send_event(int do_flush)
+{
+        snd_seq_ev_set_direct(&ev);
+        snd_seq_ev_set_source(&ev, my_port);
+        snd_seq_ev_set_dest(&ev, seq_client, seq_port);
+
+        snd_seq_event_output(seq_handle, &ev);
+        if (do_flush)
+                snd_seq_flush_output(seq_handle);
+}
+
+int MidiDriver_ALSA::open(int mode) {
+	char * var;
+	unsigned int caps;
+	
+        if (_mode != 0)
+		return MERR_ALREADY_OPEN;
+	_mode=mode;
+	if (mode!=MO_SIMPLE) return MERR_STREAMING_NOT_AVAILABLE;
+	
+	if (!(var = getenv("SCUMMVM_PORT"))) {
+		error("You have to define the environnement variable SCUMMVM_PORT");
+		return -1;
+	}
+	
+	if (parse_addr(var, &seq_client, &seq_port) < 0) {
+		error("Invalid port %s", var);
+		return -1;
+	}
+
+	if (my_snd_seq_open(&seq_handle)) {
+		error("Can't open sequencer");
+		return -1;
+	}
+	
+	my_client = snd_seq_client_id(seq_handle);
+	snd_seq_set_client_name(seq_handle, "SCUMMVM");
+	snd_seq_set_client_group(seq_handle, "input");
+	
+	caps = SND_SEQ_PORT_CAP_READ;
+	if (seq_client == SND_SEQ_ADDRESS_SUBSCRIBERS)
+		caps = ~SND_SEQ_PORT_CAP_SUBS_READ;
+	my_port = snd_seq_create_simple_port(seq_handle, "SCUMMVM", caps, SND_SEQ_PORT_TYPE_MIDI_GENERIC | SND_SEQ_PORT_TYPE_APPLICATION);
+	if (my_port < 0) {
+	    snd_seq_close(seq_handle);
+	    error("Can't create port");
+	    return -1;
+	}
+
+        if (seq_client != SND_SEQ_ADDRESS_SUBSCRIBERS) {
+                /* subscribe to MIDI port */
+                if (snd_seq_connect_to(seq_handle, my_port, seq_client, seq_port) < 0) {
+                        snd_seq_close(seq_handle);
+                        error("Can't subscribe to MIDI port (%d:%d)", seq_client, seq_port);
+                        return -1;
+                }
+        }
+
+	printf("ALSA client initialised [%d:%d]\n", my_client, my_port);
+	
+	return 0;
+}
+
+void MidiDriver_ALSA::close() {
+    _mode = 0;
+    snd_seq_close(seq_handle);
+}
+
+
+void MidiDriver_ALSA::send(uint32 b)
+{
+	unsigned int midiCmd[4];
+	ev.type = SND_SEQ_EVENT_OSS;
+	ev.data.raw8.d[0] = b;
+
+	midiCmd[3] = (b & 0xFF000000) >> 24;
+	midiCmd[2] = (b & 0x00FF0000) >> 16;
+	midiCmd[1] = (b & 0x0000FF00) >> 8;
+	midiCmd[0] = (b & 0x000000FF);
+
+	unsigned char chanID = midiCmd[0] & 0x0F;
+	switch (midiCmd[0] & 0xF0) {
+	case 0x80:
+		snd_seq_ev_set_noteoff(&ev, chanID, midiCmd[1], midiCmd[2]);
+		send_event(1);
+		break;
+	case 0x90:
+		snd_seq_ev_set_noteon(&ev, chanID, midiCmd[1], midiCmd[2]);
+		send_event(1);
+		break;
+
+	case 0xB0:										// Effect
+		snd_seq_ev_set_controller(&ev, chanID, midiCmd[1], midiCmd[2]);
+		send_event(1);
+		break;
+	case 0xC0:
+		snd_seq_ev_set_pgmchange(&ev, chanID, midiCmd[1]);
+		send_event(0);
+		break;
+
+	case 0xE0:{									// Pitch bend
+			long theBend =
+				((((long)midiCmd[1] + (long)(midiCmd[2] << 8))) - 0x4000) / 4;
+			snd_seq_ev_set_pitchbend(&ev, chanID, theBend);
+			send_event(1);
+		}
+		break;
+
+	default:
+		error("Unknown Command: %08x\n", (int)b);
+		break;
+	}
+}
+
+void MidiDriver_ALSA::pause(bool pause) {
+	if (_mode == MO_STREAMING) {
+	}
+}
+
+void MidiDriver_ALSA::set_stream_callback(void *param, StreamCallback *sc) {
+	_stream_param = param;
+	_stream_proc = sc;
+}
+
+MidiDriver *MidiDriver_ALSA_create() {
+	return new MidiDriver_ALSA();
+}
+
+#endif
+
+
 #if 0
 
 /* Old code for timidity support, maybe somebody can rewrite this for the 
@@ -1503,3 +1702,4 @@ void MidiDriver::midiInitTimidity()
 
 
 #endif /* 0 */
+