seq.c

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seq_type seq_alloc()
{
    seq_type seq;
    seq = (seq_type) memget(sizeof(seq_node));
    return seq;
}    


/* seq_at_end -- set the function to be called at sequence end */
/**/
void seq_at_end(seq, fn)
  seq_type seq;
  void (*fn)(seq_type);
{
    if (!fn) fn = noop;
    seq->stopfunc = fn;
}


/* seq_cause_noteoff_meth -- turn off a note in the future */
/**/
void seq_cause_noteoff_meth(seq, delay, voice, pitch)
  seq_type seq;
  time_type delay;
  int voice;
  int pitch;
{
    if (seq->note_enable) {
        pitch += seq->transpose;
        while (pitch < 0) pitch += 12;
        while (pitch > 127) pitch -= 12;
        seq->noteoff_count++;
        causepri((delay_type) delay, 10, seq->noteoff_fn,
                 seq, voice, pitch);
    }
}

/* seq_copy -- copy a sequence, share the eventlist */
/**/
seq_type seq_copy(from_seq)
  seq_type from_seq;
{
    register seq_type seq = seq_init(seq_alloc(), FALSE);
    if (!seq) return NULL;
    seq->chunklist = from_seq->chunklist;
    seq->current = seq_events(seq);
    seq->chunklist->u.info.refcount++;
    seq->transpose = from_seq->transpose;
    seq->loudness = from_seq->loudness;
    seq->rate = from_seq->rate;
    seq->paused = from_seq->paused;
    seq->noteoff_count = 0;
    return seq;
}


/* seq_create -- create a seq structure and an initial event chunk */
/**/
seq_type seq_create()
{
    return seq_init(seq_alloc(), TRUE);
}


/* seq_cycle -- set parameters for cycling a sequence */
/**/
void seq_cycle(seq_type seq, boolean flag, time_type dur)
{
    seq->cycleflag = flag;
    seq->cycledur = dur;
}


/* seq_end_event -- call this when an score-generated event ends */
/*
 * Assumes that noteoff_count was incremented when event started.
 */
void seq_end_event(seq)
  seq_type seq;
{
    /*gprintf(TRANS, "nd");*/
    seq->noteoff_count--;
    if (seq->current == NULL /* finished seq */ &&
        seq->noteoff_count == 0 /* finished noteoff's */ &&
        seq->runflag /* we've not been stopped */) {
        if (seq->cycleflag) {
            cause((delay_type) (seq->cycledur - virttime), cycle, seq);
        } else if (seq->stopfunc) {
            (*(seq->stopfunc))(seq);
        }
    }
}



/****************************************************************************
*               seq_free_meth
* Input: a seq_type
* Effect:
*    frees storage occupied by a seq
****************************************************************************/

private void seq_free_meth(seq)
  seq_type seq;
{
    seq_free_chunks(seq);
    if (seq->timebase) timebase_free(seq->timebase);
    memfree((void *) seq, sizeof(seq_node));
}


/* seq_free_chunks -- free storage for note list */
/*
 * NOTE: in its original form, this routine was perhaps more readable,
 * but would not compile under Microsoft C V7.00 due to a compiler bug.
 * I rewrote the code until the bug disappeared, hopefully without
 * changing the semantics!  If you change this code, make sure it still
 * compiles under Microsoft C.
 *
 * This module frees chunks from a seq_type in preparation for freeing
 * the seq_type itself.  Reference counts are checked and chunks are
 * only freed when the last reference is removed.
 */
public void seq_free_chunks(seq)
  seq_type seq;
{
    chunk_type tail;
    chunk_type head;

    head = seq->chunklist;
    if (((head->u.info.refcount)--) != 0) return;

    while (head != NULL) {
        tail = head->next;
        memfree((void *) head, sizeof(chunk_node));
        head = tail;
        seq->chunklist = head;
    }
}


seq_type seq_init(seq, create_chunk)
    seq_type seq;
    int create_chunk;
{
    if (!seq || !(seq->timebase = timebase_create(50))) {
        return NULL;
    }
    seq->chunklist = NULL;
    if (create_chunk) {
        seq->chunklist = chunk_create(TRUE);
        if (!seq->chunklist) {
            seq_free(seq);
            return NULL;
        }
    }
    seq->cause_noteoff_fn = seq_cause_noteoff_meth;
    seq->midi_bend_fn     = seq_midi_bend_meth;
    seq->midi_ctrl_fn     = seq_midi_ctrl_meth;
    seq->midi_program_fn  = seq_midi_program_meth;
    seq->midi_touch_fn    = seq_midi_touch_meth;
    seq->noteoff_fn       = seq_noteoff_meth;
    seq->noteon_fn        = seq_noteon_meth;
    seq->free_fn          = seq_free_meth;
    seq->reset_fn         = seq_reset_meth;

    seq->current = NULL;
    seq->transpose = 0;
    seq->loudness = 0;
    seq->cycleflag = FALSE;
    seq->cycledur = 0L;
    seq->rate = 256L;
    seq->paused = FALSE;
    seq->stopfunc = noop;
    seq->channel_mask = 0xFFFFFFFFL;
    seq->runflag = seq->note_enable = FALSE;
    return seq;
}


/* seq_midi_bend_meth -- send a midi bend */
/**/
void seq_midi_bend_meth(seq_type seq, int voice, int value)
{
    midi_bend(voice, value);
}


/* seq_midi_ctrl_meth -- send a midi ctrl change */
/**/
void seq_midi_ctrl_meth(seq_type seq, int voice, int ctrl, int value)
{
    midi_ctrl(voice, ctrl, value);
}


/* seq_midi_program_meth -- send a midi program change */
/**/
void seq_midi_program_meth(seq_type seq, int voice, int prog)
{
    midi_bend(voice, prog);
}


/* seq_midi_touch_meth -- send a midi touch */
/**/
void seq_midi_touch_meth(seq_type seq, int voice, int value)
{
    midi_touch(voice, value);
}


/* seq_noteoff_meth -- turn a seq note off */
/**/
void seq_noteoff_meth(seq, voice, pitch)
  seq_type seq;
  int voice;
  int pitch;
{
    midi_note(voice, pitch, 0);
        /*gprintf(TRANS, "_e");*/
    seq_end_event(seq);
}


/* seq_noteon_meth -- play a note with transformations */
/**/
void seq_noteon_meth(seq, chan, pitch, vel)
  seq_type seq;
  int chan, pitch, vel;
{
    if (seq->note_enable) {
        pitch += seq->transpose;
        while (pitch < 0) pitch += 12;
        while (pitch > 127) pitch -= 12;

        vel += seq->loudness;
        if (vel <= 0) vel = 1;
        else if (vel > 127) vel = 127;

        midi_note(chan, pitch, vel);
    }
}


/* seq_pause -- stop playing momentarily or resume playing */
/**/
time_type seq_pause(seq_type seq, boolean flag)
{
    if (!seq->paused && flag) {
        seq->paused = TRUE;
        seq->rate = seq->timebase->rate;
        set_rate(seq->timebase, STOPRATE);
    } else if (seq->paused && !flag) {
        seq_play(seq);
    }
    return (time_type) seq->timebase->virt_base;
}


/* seq_play -- play a sequence from the current event forward */
/**/
void seq_play(seq)
  seq_type seq;
{
    timebase_type prev_timebase = timebase;
    register timebase_type reg_timebase = seq->timebase;

    if (!seq->runflag) {
        seq_reset(seq);
    }
    if (!seq->paused) return;
    eventtime = gettime();

    /* assume that virt_base is correct virtual time as the result
        of seq_start_time or seq_reset
     */
    timebase = reg_timebase;
    virttime = reg_timebase->virt_base;
    /* note that set_rate will set reg_timebase->real_base to eventtime */
    set_rate(reg_timebase, seq->rate);
    seq->paused = FALSE; /* in case the score had been paused; note that
                            seq_pause() has no effect if paused is TRUE */
    seq->runflag = TRUE;
    seq->note_enable = TRUE;

    /* restore previous timebase */
    timebase_use(prev_timebase);
}


/* seq_reset_meth -- reset a sequence to start back at the first event */
/**/
void seq_reset_meth(seq)
  seq_type seq;
{
    timebase_type old_timebase = timebase;

    if (seq->runflag) {
        /* maybe this seq is already reset, and process_event is
         * already scheduled.  If so, don't schedule another one.
         */
        if ((seq->timebase->virt_base == 0) &&
            (seq->timebase->rate == STOPRATE)) {
            /* in case the reader just iterated through the list without
             * cause'ing events, reset the event list
             */
            seq->current = seq_events(seq);
            return;
        }
        /* Otherwise, the seq is running, so stop it. */
        seq_stop(seq);
    }
    
    timebase_use(seq->timebase);
    set_rate(seq->timebase, STOPRATE);
    set_virttime(seq->timebase, 0L);
    seq->current = seq_events(seq);
    seq->noteoff_count = 0L;
    seq->runflag = TRUE;
    seq->paused = TRUE;
    if (seq->current)
        cause((delay_type)(seq->current->ntime - virttime), process_event, seq);
    timebase_use(old_timebase);
}


/* seq_set_loudness -- set the loudness offset of a sequence */
/**/
void seq_set_loudness(seq, loud)
  seq_type seq;
  int loud;
{
    seq->loudness = loud;
}

/* seq_set_rate -- set the rate of a sequence */
/**/
void seq_set_rate(seq, rate)
  seq_type seq;
  time_type rate;
{
    seq->rate = rate;
    if (!seq->paused) set_rate(seq->timebase, rate);
}


/* seq_set_transpose -- set the sequence transposition */
/**/
void seq_set_transpose(seq, trans)
  seq_type seq;
  int trans;
{
    seq->transpose = trans;
}


/* seq_start_time -- set the current pointer so the sequence starts here */
/**/
void seq_start_time(seq, start_time)
  seq_type seq;
  time_type start_time;
{
    timebase_type prev_timebase = timebase;
    if (!seq->runflag) {
        seq_reset(seq);
    }
    if (real_to_virt(seq->timebase, eventtime) > start_time) {
        seq_reset(seq);
    }
    timebase_use(seq->timebase);
    seq->note_enable = FALSE;
    /* prime the pump */
    set_rate(timebase, STOPRATE);
    set_virttime(timebase, start_time);
    catchup();
    seq->note_enable = TRUE;
    seq->paused = TRUE;
    /* restore previous timebase */
    timebase_use(prev_timebase);
}


/* seq_stop -- stop a sequence, clear out all pending events */
/**/
void seq_stop(seq)
  seq_type seq;
{
    timebase_type prev_timebase = timebase;

    if (seq->runflag) {
        if (moxcdebug)
            gprintf(TRANS, "seq_reset swap from timebase 0x%x to 0x%x\n",
                    timebase, seq->timebase);
        timebase = seq->timebase;
        seq->runflag = FALSE;
        set_rate(timebase, STOPRATE);
        set_virttime(timebase, MAXTIME);
        catchup();
    }
    timebase_use(prev_timebase);
}