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temporal: add reimplemented version of 6.x's TempoMap::gui_stretch_tempo()

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This commit is contained in:
Paul Davis 2022-05-12 12:14:45 -06:00
parent db9cc04230
commit 45de3694cc
2 changed files with 90 additions and 0 deletions
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86
libs/temporal/tempo.cc
View file

@ -3028,6 +3028,92 @@ TempoMap::set_ramped (TempoPoint & tp, bool yn)
reset_starting_at (tp.sclock() + 1);
}
void
TempoMap::stretch_tempo (TempoPoint* ts, const samplepos_t sample, const samplepos_t end_sample, Beats const & start_qnote, Beats const & end_qnote)
{
/*
Ts (future prev_t) Tnext
| |
| [drag^] |
|----------|----------
e_f qn_beats(sample)
*/
if (!ts) {
return;
}
superclock_t start_sclock = samples_to_superclock (sample, TEMPORAL_SAMPLE_RATE);
superclock_t end_sclock = samples_to_superclock (end_sample, TEMPORAL_SAMPLE_RATE);
/* minimum allowed measurement distance in samples */
const superclock_t min_delta_sclock = samples_to_superclock (2, TEMPORAL_SAMPLE_RATE);
double new_bpm;
if (ts->clamped()) {
/* this tempo point is required to start using the same bpm
* that the previous tempo ended with.
*/
TempoPoint* next_t = const_cast<TempoPoint*> (next_tempo (*ts));
TempoPoint* prev_to_ts = const_cast<TempoPoint*> (previous_tempo (*ts));
assert (prev_to_ts);
/* the change in samples is the result of changing the slope of at most 2 previous tempo sections.
* constant to constant is straightforward, as the tempo prev to ts has constant slope.
*/
double contribution = 0.0;
if (next_t && prev_to_ts->ramped()) {
const DoubleableBeats delta_tp = ts->beats() - prev_to_ts->beats();
const DoubleableBeats delta_np = next_t->beats() - prev_to_ts->beats();
contribution = delta_tp.to_double() / delta_np.to_double();
}
samplepos_t const fr_off = end_sclock - start_sclock;
sampleoffset_t const ts_sample_contribution = fr_off - (contribution * (double) fr_off);
if (start_sclock > prev_to_ts->sclock() + min_delta_sclock && (start_sclock + ts_sample_contribution) > prev_to_ts->sclock() + min_delta_sclock) {
DoubleableBeats delta_sp = start_qnote - prev_to_ts->beats();
DoubleableBeats delta_ep = end_qnote - prev_to_ts->beats();
new_bpm = ts->note_types_per_minute() * (delta_sp.to_double() / delta_ep.to_double());
} else {
new_bpm = ts->note_types_per_minute();
}
} else {
/* ts is free to have it's bpm changed to any value (within limits) */
if (start_sclock > ts->sclock() + min_delta_sclock && end_sclock > ts->sclock() + min_delta_sclock) {
new_bpm = ts->note_types_per_minute() * ((start_sclock - ts->sclock()) / (double) (end_sclock - ts->sclock()));
} else {
new_bpm = ts->note_types_per_minute();
}
new_bpm = std::min (new_bpm, 1000.0);
}
/* don't clamp and proceed here.
testing has revealed that this can go negative,
which is an entirely different thing to just being too low.
*/
if (new_bpm < 0.5) {
return;
}
ts->set_note_types_per_minute (new_bpm);
if (ts->clamped()) {
TempoPoint* prev = 0;
if ((prev = const_cast<TempoPoint*> (previous_tempo (*ts))) != 0) {
prev->set_end_note_types_per_minute (ts->note_types_per_minute());
}
}
reset_starting_at (ts->sclock() + 1);
}
void
TempoMap::twist_tempi (TempoPoint* ts, timepos_t const & start, timepos_t const & end)
{

4
libs/temporal/temporal/tempo.h
View file

@ -216,7 +216,9 @@ class LIBTEMPORAL_API Tempo : public Rampable {
double quarter_notes_per_minute() const { return (superclock_ticks_per_second() * 60.0 * 4.0) / (_note_type * _superclocks_per_note_type); }
double samples_per_note_type(samplecnt_t sr) const { return superclock_to_samples (superclocks_per_note_type (), sr); }
double samples_per_quarter_note(samplecnt_t sr) const { return superclock_to_samples (superclocks_per_quarter_note(), sr); }
void set_note_types_per_minute (double npm) { _superclocks_per_note_type = double_npm_to_scpn (npm); }
void set_end_note_types_per_minute (double npm) { _end_superclocks_per_note_type = double_npm_to_scpn (npm); }
int note_type () const { return _note_type; }
Beats note_type_as_beats () const { return Beats (0, (1920 * 4) / _note_type); }
@ -734,6 +736,8 @@ class /*LIBTEMPORAL_API*/ TempoMap : public PBD::StatefulDestructible
LIBTEMPORAL_API int set_state (XMLNode const&, int version);
LIBTEMPORAL_API void twist_tempi (TempoPoint* ts, timepos_t const & start, timepos_t const & end);
LIBTEMPORAL_API void stretch_tempo (TempoPoint* ts, const samplepos_t sample, const samplepos_t end_sample, Beats const & start_qnote, Beats const & end_qnote);
LIBTEMPORAL_API void stretch_tempo_end (TempoPoint* ts, const samplepos_t sample, const samplepos_t end_sample);
/* END OF MODIFYING METHODS */