Alg_parameters_ptr Alg_reader::process_attributes(
Alg_parameters_ptr attributes, double time)
{
// print "process_attributes:", attributes
bool ts_flag = false;
if (attributes) {
Alg_parameters_ptr a;
bool in_seconds = seq->get_units_are_seconds();
if (a = Alg_parameters::remove_key(&attributes, "tempor")) {
double tempo = a->parm.r;
seq->insert_tempo(tempo, seq->get_time_map()->time_to_beat(time));
}
if (a = Alg_parameters::remove_key(&attributes, "beatr")) {
double beat = a->parm.r;
seq->insert_beat(time, beat);
}
if (a = Alg_parameters::remove_key(&attributes, "timesig_numr")) {
tsnum = a->parm.r;
ts_flag = true;
}
if (a = Alg_parameters::remove_key(&attributes, "timesig_denr")) {
tsden = a->parm.r;
ts_flag = true;
}
if (ts_flag) {
seq->set_time_sig(seq->get_time_map()->time_to_beat(time),
tsnum, tsden);
}
if (in_seconds) seq->convert_to_seconds();
}
return attributes; // in case it was modified
}
Alg_seq_ptr NoteTrack::MakeExportableSeq()
{
double offset = GetOffset();
if (offset == 0)
return mSeq;
// make a copy, deleting events that are shifted before time 0
double start = -offset;
if (start < 0) start = 0;
// notes that begin before "start" are not included even if they
// extend past "start" (because "all" parameter is set to false)
Alg_seq_ptr seq = mSeq->copy(start, mSeq->get_dur() - start, false);
if (offset > 0) {
// swap seq and mSeq so that Shift operates on the new copy
Alg_seq_ptr old_seq = mSeq;
mSeq = seq;
Shift(offset);
seq = mSeq; // undo the swap
mSeq = old_seq;
#ifdef OLD_CODE
// now shift events by offset. This must be done with an integer
// number of measures, so first, find the beats-per-measure
double beats_per_measure = 4.0;
Alg_time_sig_ptr tsp = NULL;
if (seq->time_sig.length() > 0 && seq->time_sig[0].beat < ALG_EPS) {
// there is an initial time signature
tsp = &(seq->time_sig[0]);
beats_per_measure = (tsp->num * 4) / tsp->den;
}
// also need the initial tempo
double bps = ALG_DEFAULT_BPM / 60;
Alg_time_map_ptr map = seq->get_time_map();
Alg_beat_ptr bp = &(map->beats[0]);
if (bp->time < ALG_EPS) { // tempo change at time 0
if (map->beats.len > 1) { // compute slope to get tempo
bps = (map->beats[1].beat - map->beats[0].beat) /
(map->beats[1].time - map->beats[0].time);
} else if (seq->get_time_map()->last_tempo_flag) {
bps = seq->get_time_map()->last_tempo;
}
}
// find closest number of measures to fit in the gap
// number of measures is offset / measure_time
double measure_time = beats_per_measure / bps; // seconds per measure
int n = ROUND(offset / measure_time);
if (n == 0) n = 1;
// we will insert n measures. Compute the desired duration of each.
measure_time = offset / n;
bps = beats_per_measure / measure_time;
// insert integer multiple of measures at beginning
seq->convert_to_beats();
seq->insert_silence(0, beats_per_measure * n);
// make sure time signature at 0 is correct
if (tsp) {
seq->set_time_sig(0, tsp->num, tsp->den);
}
// adjust tempo to match offset
seq->set_tempo(bps * 60.0, 0, beats_per_measure * n);
#endif
} else {
// if offset is negative, it might not be a multiple of beats, but
// we want to preserve the relative positions of measures. I.e. we
// should shift barlines and time signatures as well as notes.
// Insert a time signature at the first bar-line if necessary.
// Translate start from seconds to beats and call it beat:
double beat = mSeq->get_time_map()->time_to_beat(start);
// Find the time signature in mSeq in effect at start (beat):
int i = mSeq->time_sig.find_beat(beat);
// i is where you would insert a new time sig at beat,
// Case 1: beat coincides with a time sig at i. Time signature
// at beat means that there is a barline at beat, so when beat
// is shifted to 0, the relative barline positions are preserved
if (mSeq->time_sig.length() > 0 &&
within(beat, mSeq->time_sig[i].beat, ALG_EPS)) {
// beat coincides with time signature change, so offset must
// be a multiple of beats
/* do nothing */ ;
// Case 2: there is no time signature before beat.
} else if (i == 0 && (mSeq->time_sig.length() == 0 ||
mSeq->time_sig[i].beat > beat)) {
// If beat does not fall on an implied barline, we need to
// insert a time signature.
double measures = beat / 4.0;
double imeasures = ROUND(measures);
if (!within(measures, imeasures, ALG_EPS)) {
double bar_offset = (int(measures) + 1) * 4.0 - beat;
seq->set_time_sig(bar_offset, 4, 4);
}
// This case should never be true because if i == 0, either there
// are no time signatures before beat (Case 2),
// or there is one time signature at beat (Case 1)
} else if (i == 0) {
/* do nothing (might be good to assert(false)) */ ;
// Case 3: i-1 must be the effective time sig position
} else {
i -= 1; // index the time signature in effect at beat
Alg_time_sig_ptr tsp = &(mSeq->time_sig[i]);
double beats_per_measure = (tsp->num * 4) / tsp->den;
double measures = (beat - tsp->beat) / beats_per_measure;
int imeasures = ROUND(measures);
if (!within(measures, imeasures, ALG_EPS)) {
// beat is not on a measure, so we need to insert a time sig
// to force a bar line at the first measure location after
// beat
double bar = tsp->beat + beats_per_measure * (int(measures) + 1);
double bar_offset = bar - beat;
// insert new time signature at bar_offset in new sequence
// It will have the same time signature, but the position will
// force a barline to match the barlines in mSeq
seq->set_time_sig(bar_offset, tsp->num, tsp->den);
}
// else beat coincides with a barline, so no need for an extra
// time signature to force barline alignment
}
}
return seq;
}
void Alg_midifile_reader::Mf_timesig(int i1, int i2, int i3, int i4)
{
seq->set_time_sig(double(get_currtime()) / divisions, i1, 1 << i2);
}
