path: root/pd/src/s_midi_alsa.c

/* Copyright (c) 1997-1999 Guenter Geiger, Miller Puckette, Larry Troxler,
* Winfried Ritsch, Karl MacMillan, and others.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */

/* MIDI I/O for Linux using ALSA */

#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <alsa/asoundlib.h>
#include "m_pd.h"
#include "s_stuff.h"

static int alsa_nmidiin;
static int alsa_midiinfd[MAXMIDIINDEV];
static int alsa_nmidiout;
static int alsa_midioutfd[MAXMIDIOUTDEV];

static snd_seq_t *midi_handle;

static snd_midi_event_t *midiev;



static unsigned short CombineBytes(unsigned char First, unsigned char Second)
{
    unsigned short _14bit;
    _14bit = (unsigned short)Second;
    _14bit <<= 7;
    _14bit |= (unsigned short)First;
    return(_14bit);
}

void sys_alsa_do_open_midi(int nmidiin, int *midiinvec,
    int nmidiout, int *midioutvec)
{

    char portname[50];
    int err = 0;
    int client;
    int i;
    snd_seq_client_info_t *alsainfo;
    /* do we want to connect pd automatically with other devices ?; see below! */
    /* LATER: think about a flag to enable/disable automatic connection
     *        (sometimes it could be a pain)
     */
    int autoconnect = 1;
    alsa_nmidiin = 0;
    alsa_nmidiout = 0;

    if (nmidiout == 0 && nmidiin == 0) return;

    if(nmidiin>MAXMIDIINDEV )
      {
        post("midi input ports reduced to maximum %d", MAXMIDIINDEV);
        nmidiin=MAXMIDIINDEV;
      }
    if(nmidiout>MAXMIDIOUTDEV)
      {
        post("midi output ports reduced to maximum %d", MAXMIDIOUTDEV);
        nmidiout=MAXMIDIOUTDEV;
      }

    if (nmidiin>0 && nmidiout>0)
        err = snd_seq_open(&midi_handle,"default",SND_SEQ_OPEN_DUPLEX,0);
    else if (nmidiin > 0)
        err = snd_seq_open(&midi_handle,"default",SND_SEQ_OPEN_INPUT,0);
    else if (nmidiout > 0)
        err = snd_seq_open(&midi_handle,"default",SND_SEQ_OPEN_OUTPUT,0);
    
    if (err!=0)
    {
            sys_setalarm(1000000);
            post("couldn't open alsa sequencer");
            return;
    }
    for (i=0;i<nmidiin;i++)
    {
        int port;
        sprintf(portname,"Pure Data Midi-In %d",i+1);
        port = snd_seq_create_simple_port(midi_handle,portname,
                                          SND_SEQ_PORT_CAP_WRITE |SND_SEQ_PORT_CAP_SUBS_WRITE, 
                                          SND_SEQ_PORT_TYPE_APPLICATION);
        alsa_midiinfd[i] = port;        
        if (port < 0) goto error;        
    }

    for (i=0;i<nmidiout;i++)
    {
        int port;
        sprintf(portname,"Pure Data Midi-Out %d",i+1);
        port = snd_seq_create_simple_port(midi_handle,portname,
                                          SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ, 
                                          SND_SEQ_PORT_TYPE_APPLICATION);
        alsa_midioutfd[i] = port;       
        if (port < 0) goto error;        
    }
   
    snd_seq_client_info_malloc(&alsainfo);
    snd_seq_get_client_info(midi_handle,alsainfo);
    snd_seq_client_info_set_name(alsainfo,"Pure Data");
    client = snd_seq_client_info_get_client(alsainfo);
    snd_seq_set_client_info(midi_handle,alsainfo);
    snd_seq_client_info_free(alsainfo);
    post("Opened Alsa Client %d in:%d out:%d",client,nmidiin,nmidiout);
    sys_setalarm(0);
    snd_midi_event_new(20,&midiev);
    alsa_nmidiout = nmidiout;
    alsa_nmidiin = nmidiin;

    /* JMZ: connect all available devices to pd */
    if (autoconnect)
      {

        snd_seq_client_info_t *cinfo;
        snd_seq_port_info_t *pinfo;

        snd_seq_port_subscribe_t *subs;
        snd_seq_addr_t other, topd, frompd;
        /* since i don't know how to connect multiple ports
         * (connect everything to each port, modulo,...),
         * i only fully connect where we have only one single port
         */
        if(alsa_nmidiin)
          {
            topd.client  =client;
            topd.port    =alsa_midiinfd[0];
          }
        if(alsa_nmidiout)
          {
            frompd.client  =client;
            frompd.port    =alsa_midioutfd[0];
          }

        snd_seq_port_subscribe_alloca(&subs);
        
        snd_seq_client_info_alloca(&cinfo);
        snd_seq_port_info_alloca(&pinfo);
        snd_seq_client_info_set_client(cinfo, -1);
        while (snd_seq_query_next_client(midi_handle, cinfo) >= 0)
          {
            /* reset query info */
            int client_id=snd_seq_client_info_get_client(cinfo);
            
            if((SND_SEQ_CLIENT_SYSTEM != client_id)&&(client != client_id))
              { /* skipping port 0 and ourself */
                snd_seq_port_info_set_client(pinfo, client_id);
                snd_seq_port_info_set_port(pinfo, -1);
                while (snd_seq_query_next_port(midi_handle, pinfo) >= 0) 
                  {
                    other.client=client_id;
                    other.port  =snd_seq_port_info_get_port(pinfo);
                    if(1==alsa_nmidiin) /* only autoconnect 1st port */
                      {
                        snd_seq_port_subscribe_set_sender(subs, &other);
                        snd_seq_port_subscribe_set_dest(subs, &topd);
                        snd_seq_subscribe_port(midi_handle, subs);
                      }
                    if(1==alsa_nmidiout) /* only autoconnect 1st port */
                      {
                        snd_seq_port_subscribe_set_sender(subs, &frompd);
                        snd_seq_port_subscribe_set_dest(subs, &other);
                        snd_seq_subscribe_port(midi_handle, subs);
                      }
                  }
              }
          }
      }
    return;
 error:
    sys_setalarm(1000000);
    post("couldn't open alsa MIDI output device");
    return;
}

#define md_msglen(x) (((x)<0xC0)?2:((x)<0xE0)?1:((x)<0xF0)?2:\
    ((x)==0xF2)?2:((x)<0xF4)?1:0)

void sys_alsa_putmidimess(int portno, int a, int b, int c)
{
    int channel;
    snd_seq_event_t ev;
    snd_seq_ev_clear(&ev);
    if (portno >= 0 && portno < alsa_nmidiout)
    {
        if (a >= 224)   // pitchbend
        {
            channel = a-224;
            snd_seq_ev_set_pitchbend(&ev,channel,CombineBytes(b,c));
        }
        else if (a >= 208)      // touch
        {
            channel = a-208;
            snd_seq_ev_set_chanpress(&ev,channel,b);
        }
        else if (a >= 192)      // program
        {
            channel = a-192;
            snd_seq_ev_set_pgmchange(&ev,channel,b);
        }
        else if (a >= 176)      // controller
        {
            channel = a-176;
            snd_seq_ev_set_controller(&ev,channel,b,c);
        }
        else if (a >= 160)      // polytouch
        {
            channel = a-160;
            snd_seq_ev_set_keypress(&ev,channel,b,c);
        }
        else if (a >= 144)      // note
        {
            channel = a-144;
            if (c)
                snd_seq_ev_set_noteon(&ev,channel,b,c);
            else
                snd_seq_ev_set_noteoff(&ev,channel,b,c);
        }
        snd_seq_ev_set_direct(&ev);
        snd_seq_ev_set_subs(&ev);
        snd_seq_ev_set_source(&ev,alsa_midioutfd[portno]);
        snd_seq_event_output_direct(midi_handle,&ev);
    }
    //post("%d %d %d\n",a,b,c);
}

void sys_alsa_putmidibyte(int portno, int byte)
{
    snd_seq_event_t ev;
    snd_seq_ev_clear(&ev);
    if (portno >= 0 && portno < alsa_nmidiout)
    {
        // repack into 1 byte char and put somewhere to point at
        unsigned char data = (unsigned char)byte;

        snd_seq_ev_set_sysex(&ev,1,&data); //...set_variable *should* have worked but didn't
        snd_seq_ev_set_direct(&ev);
        snd_seq_ev_set_subs(&ev);
        snd_seq_ev_set_source(&ev,alsa_midioutfd[portno]);
        snd_seq_event_output_direct(midi_handle,&ev);
    }
}


    /* this version uses the asynchronous "read()" ... */
void sys_alsa_poll_midi(void)
{
   unsigned char buf[20];
   int count, alsa_source;
   int i;
   snd_seq_event_t *midievent = NULL;

   if (alsa_nmidiout == 0 && alsa_nmidiin == 0) return;
   
   snd_midi_event_init(midiev);

   if (!alsa_nmidiout && !alsa_nmidiin) return;
   count = snd_seq_event_input_pending(midi_handle,1);
   if (count != 0)
        count = snd_seq_event_input(midi_handle,&midievent);
   if (midievent != NULL)
   {
       count = snd_midi_event_decode(midiev,buf,20,midievent);
       alsa_source = midievent->dest.port;
       for(i=0;i<count;i++)
           sys_midibytein(alsa_source, (buf[i] & 0xff));
       //post("received %d midi bytes\n",count);
   }
}

void sys_alsa_close_midi()
{
    alsa_nmidiin = alsa_nmidiout = 0;
    if(midi_handle)
      {
        snd_seq_close(midi_handle);
        if(midiev)
          {
            snd_midi_event_free(midiev);
          }
      }
}

#define NSEARCH 10
static int alsa_nmidiindevs, alsa_nmidioutdevs, alsa_initted;

void midi_alsa_init(void)     
{
    int i;
    if (alsa_initted)
        return;
    alsa_initted = 1;
}

void midi_alsa_getdevs(char *indevlist, int *nindevs,
    char *outdevlist, int *noutdevs, int maxndev, int devdescsize)
{
    int i, ndev;
    if ((ndev = alsa_nmidiindevs) > maxndev)
        ndev = maxndev;
    for (i = 0; i < ndev; i++)
        sprintf(indevlist + i * devdescsize, "ALSA MIDI device #%d", i+1);
    *nindevs = ndev;

    if ((ndev = alsa_nmidioutdevs) > maxndev)
        ndev = maxndev;
    for (i = 0; i < ndev; i++)
        sprintf(outdevlist + i * devdescsize, "ALSA MIDI device #%d", i+1);
    *noutdevs = ndev;
}