using namespace ARDOUR;
using namespace PBD;
+using Timecode::BBT_Time;
+
/* _default tempo is 4/4 qtr=120 */
Meter TempoMap::_default_meter (4.0, 4.0);
Tempo TempoMap::_default_tempo (120.0);
-const double Meter::ticks_per_beat = 1920.0;
-
-double Tempo::frames_per_beat (nframes_t sr, const Meter& meter) const
+double Tempo::frames_per_beat (framecnt_t sr, const Meter& meter) const
{
return ((60.0 * sr) / (_beats_per_minute * meter.note_divisor()/_note_type));
}
/***********************************************************************/
double
-Meter::frames_per_bar (const Tempo& tempo, nframes_t sr) const
+Meter::frames_per_bar (const Tempo& tempo, framecnt_t sr) const
{
return ((60.0 * sr * _beats_per_bar) / (tempo.beats_per_minute() * _note_type/tempo.note_type()));
}
}
};
-TempoMap::TempoMap (nframes64_t fr)
+TempoMap::TempoMap (framecnt_t fr)
{
metrics = new Metrics;
_frame_rate = fr;
/* position by audio frame, then recompute BBT timestamps from the audio ones */
- nframes64_t frame = frame_time (when);
+ framepos_t frame = frame_time (when);
// cerr << "nominal frame time = " << frame << endl;
- nframes64_t prev_frame = round_to_type (frame, -1, Beat);
- nframes64_t next_frame = round_to_type (frame, 1, Beat);
+ framepos_t prev_frame = round_to_type (frame, -1, Beat);
+ framepos_t next_frame = round_to_type (frame, 1, Beat);
// cerr << "previous beat at " << prev_frame << " next at " << next_frame << endl;
}
void
-TempoMap::add_tempo (const Tempo& tempo, nframes64_t where)
+TempoMap::add_tempo (const Tempo& tempo, framepos_t where)
{
{
Glib::RWLock::WriterLock lm (lock);
}
void
-TempoMap::add_meter (const Meter& meter, nframes64_t where)
+TempoMap::add_meter (const Meter& meter, framepos_t where)
{
{
Glib::RWLock::WriterLock lm (lock);
}
void
-TempoMap::change_existing_tempo_at (nframes64_t where, double beats_per_minute, double note_type)
+TempoMap::change_existing_tempo_at (framepos_t where, double beats_per_minute, double note_type)
{
Tempo newtempo (beats_per_minute, note_type);
// cerr << "\n\n\n ######################\nTIMESTAMP via BBT ##############\n" << endl;
- nframes64_t current = 0;
- nframes64_t section_frames;
+ framepos_t current = 0;
+ framepos_t section_frames;
BBT_Time start;
BBT_Time end;
first = false;
} else {
- if (bbt.ticks > Meter::ticks_per_beat/2) {
+ if (bbt.ticks > BBT_Time::ticks_per_beat/2) {
/* round up to next beat */
bbt.beats += 1;
}
}
TempoMetric
-TempoMap::metric_at (nframes64_t frame) const
+TempoMap::metric_at (framepos_t frame) const
{
TempoMetric m (first_meter(), first_tempo());
const Meter* meter;
}
void
-TempoMap::bbt_time (nframes64_t frame, BBT_Time& bbt) const
+TempoMap::bbt_time (framepos_t frame, BBT_Time& bbt) const
{
{
Glib::RWLock::ReaderLock lm (lock);
}
void
-TempoMap::bbt_time_unlocked (nframes64_t frame, BBT_Time& bbt) const
+TempoMap::bbt_time_unlocked (framepos_t frame, BBT_Time& bbt) const
{
bbt_time_with_metric (frame, bbt, metric_at (frame));
}
void
-TempoMap::bbt_time_with_metric (nframes64_t frame, BBT_Time& bbt, const TempoMetric& metric) const
+TempoMap::bbt_time_with_metric (framepos_t frame, BBT_Time& bbt, const TempoMetric& metric) const
{
- nframes64_t frame_diff;
+ framecnt_t frame_diff;
// cerr << "---- BBT time for " << frame << " using metric @ " << metric.frame() << " BBT " << metric.start() << endl;
const double beats_per_bar = metric.meter().beats_per_bar();
- const double ticks_per_frame = metric.tempo().frames_per_beat (_frame_rate, metric.meter()) / Meter::ticks_per_beat;
+ const double ticks_per_frame = metric.tempo().frames_per_beat (_frame_rate, metric.meter()) / BBT_Time::ticks_per_beat;
/* now compute how far beyond that point we actually are. */
frame_diff = frame - metric.frame();
- bbt.ticks = metric.start().ticks + (uint32_t)round((double)frame_diff / ticks_per_frame);
- uint32_t xtra_beats = bbt.ticks / (uint32_t)Meter::ticks_per_beat;
- bbt.ticks %= (uint32_t)Meter::ticks_per_beat;
-
- bbt.beats = metric.start().beats + xtra_beats - 1; // correction for 1-based counting, see below for matching operation.
- bbt.bars = metric.start().bars + (uint32_t)floor((double)bbt.beats / beats_per_bar);
- bbt.beats = (uint32_t)fmod((double)bbt.beats, beats_per_bar);
-
- /* if we have a fractional number of beats per bar, we see if
- we're in the last beat (the fractional one). if so, we
- round ticks appropriately and bump to the next bar. */
- double beat_fraction = beats_per_bar - floor(beats_per_bar);
- /* XXX one problem here is that I'm not sure how to handle
- fractional beats that don't evenly divide ticks_per_beat.
- If they aren't handled consistently, I would guess we'll
- continue to have strange discrepancies occuring. Perhaps
- this will also behave badly in the case of meters like
- 0.1/4, but I can't be bothered to test that.
- */
- uint32_t ticks_on_last_beat = (uint32_t)floor(Meter::ticks_per_beat * beat_fraction);
-
- if (bbt.beats > (uint32_t)floor(beats_per_bar) && bbt.ticks >= ticks_on_last_beat) {
+ bbt.ticks = metric.start().ticks + (uint32_t)round((double)frame_diff / ticks_per_frame);
+ uint32_t xtra_beats = bbt.ticks / (uint32_t)BBT_Time::ticks_per_beat;
+ bbt.ticks %= (uint32_t)BBT_Time::ticks_per_beat;
+
+ bbt.beats = metric.start().beats + xtra_beats - 1; // correction for 1-based counting, see below for matching operation.
+ bbt.bars = metric.start().bars + (uint32_t)floor((double)bbt.beats / beats_per_bar);
+ bbt.beats = (uint32_t)fmod((double)bbt.beats, beats_per_bar);
+
+ /* if we have a fractional number of beats per bar, we see if
+ we're in the last beat (the fractional one). if so, we
+ round ticks appropriately and bump to the next bar. */
+ double beat_fraction = beats_per_bar - floor(beats_per_bar);
+ /* XXX one problem here is that I'm not sure how to handle
+ fractional beats that don't evenly divide ticks_per_beat.
+ If they aren't handled consistently, I would guess we'll
+ continue to have strange discrepancies occuring. Perhaps
+ this will also behave badly in the case of meters like
+ 0.1/4, but I can't be bothered to test that.
+ */
+ uint32_t ticks_on_last_beat = (uint32_t)floor(BBT_Time::ticks_per_beat * beat_fraction);
+
+ if (bbt.beats > (uint32_t)floor(beats_per_bar) && bbt.ticks >= ticks_on_last_beat) {
bbt.ticks -= ticks_on_last_beat;
bbt.beats = 0;
bbt.bars++;
- }
+ }
- bbt.beats++; // correction for 1-based counting, see above for matching operation.
+ bbt.beats++; // correction for 1-based counting, see above for matching operation.
// cerr << "-----\t RETURN " << bbt << endl;
}
-nframes64_t
-TempoMap::count_frames_between ( const BBT_Time& start, const BBT_Time& end) const
+framecnt_t
+TempoMap::count_frames_between (const BBT_Time& start, const BBT_Time& end) const
{
- /* for this to work with fractional measure types, start and end have to be "legal" BBT types,
- that means that the beats and ticks should be inside a bar
+ /* for this to work with fractional measure types, start and end have to be
+ "legal" BBT types, that means that the beats and ticks should be inside
+ a bar
*/
- nframes64_t frames = 0;
- nframes64_t start_frame = 0;
- nframes64_t end_frame = 0;
+ framecnt_t frames = 0;
+ framepos_t start_frame = 0;
+ framepos_t end_frame = 0;
TempoMetric m = metric_at (start);
uint32_t bar_offset = start.bars - m.start().bars;
double beat_offset = bar_offset*m.meter().beats_per_bar() - (m.start().beats-1) + (start.beats -1)
- + start.ticks/Meter::ticks_per_beat;
+ + start.ticks/BBT_Time::ticks_per_beat;
- start_frame = m.frame() + (nframes64_t) rint( beat_offset * m.tempo().frames_per_beat(_frame_rate, m.meter()));
+ start_frame = m.frame() + (framepos_t) rint(beat_offset * m.tempo().frames_per_beat(_frame_rate, m.meter()));
m = metric_at(end);
bar_offset = end.bars - m.start().bars;
beat_offset = bar_offset * m.meter().beats_per_bar() - (m.start().beats -1) + (end.beats - 1)
- + end.ticks/Meter::ticks_per_beat;
+ + end.ticks/BBT_Time::ticks_per_beat;
- end_frame = m.frame() + (nframes64_t) rint(beat_offset * m.tempo().frames_per_beat(_frame_rate, m.meter()));
+ end_frame = m.frame() + (framepos_t) rint(beat_offset * m.tempo().frames_per_beat(_frame_rate, m.meter()));
frames = end_frame - start_frame;
}
-nframes64_t
+framecnt_t
TempoMap::count_frames_between_metrics (const Meter& meter, const Tempo& tempo, const BBT_Time& start, const BBT_Time& end) const
{
- /* this is used in timestamping the metrics by actually counting the beats */
+ /* this is used in timestamping the metrics by actually counting the beats */
- nframes64_t frames = 0;
+ framecnt_t frames = 0;
uint32_t bar = start.bars;
double beat = (double) start.beats;
double beats_counted = 0;
// << " fpb was " << beat_frames
// << endl;
- frames = (nframes64_t) floor (beats_counted * beat_frames);
+ frames = (framecnt_t) llrint (floor (beats_counted * beat_frames));
return frames;
}
-nframes64_t
+framepos_t
TempoMap::frame_time (const BBT_Time& bbt) const
{
BBT_Time start ; /* 1|1|0 */
- return count_frames_between ( start, bbt);
+ return count_frames_between (start, bbt);
}
-nframes64_t
-TempoMap::bbt_duration_at (nframes64_t pos, const BBT_Time& bbt, int dir) const
+framecnt_t
+TempoMap::bbt_duration_at (framepos_t pos, const BBT_Time& bbt, int dir) const
{
- nframes64_t frames = 0;
+ framecnt_t frames = 0;
BBT_Time when;
bbt_time(pos, when);
return frames;
}
-nframes64_t
+framecnt_t
TempoMap::bbt_duration_at_unlocked (const BBT_Time& when, const BBT_Time& bbt, int dir) const
{
-
- nframes64_t frames = 0;
+ framecnt_t frames = 0;
double beats_per_bar;
BBT_Time result;
TempoMetric metric = metric_at(result);
beats_per_bar = metric.meter().beats_per_bar();
-
-
- /*reduce things to legal bbt values
- we have to handle possible fractional=shorter beats at the end of measures
- and things like 0|11|9000 as a duration in a 4.5/4 measure
- the musical decision is that the fractional beat is also a beat , although a shorter one
+ /* Reduce things to legal bbt values we have to handle possible
+ fractional=shorter beats at the end of measures and things like 0|11|9000
+ as a duration in a 4.5/4 measure the musical decision is that the
+ fractional beat is also a beat , although a shorter one
*/
-
if (dir >= 0) {
result.beats = when.beats + bbt.beats;
result.ticks = when.ticks + bbt.ticks;
beats_per_bar = metric.meter().beats_per_bar();
}
- /*we now counted the beats and landed in the target measure, now deal with ticks
- this seems complicated, but we want to deal with the corner case of a sequence of time signatures like 0.2/4-0.7/4
- and with request like bbt = 3|2|9000 ,so we repeat the same loop but add ticks
+
+ /* We now counted the beats and landed in the target measure, now deal
+ with ticks this seems complicated, but we want to deal with the
+ corner case of a sequence of time signatures like 0.2/4-0.7/4 and
+ with request like bbt = 3|2|9000 ,so we repeat the same loop but add
+ ticks
*/
/* of course gtk_ardour only allows bar with at least 1.0 beats .....
*/
- uint32_t ticks_at_beat = (uint32_t) ( result.beats == ceil(beats_per_bar) ?
- (1 - (ceil(beats_per_bar) - beats_per_bar))* Meter::ticks_per_beat
- : Meter::ticks_per_beat );
+ uint32_t ticks_at_beat = (uint32_t) (result.beats == ceil(beats_per_bar) ?
+ (1 - (ceil(beats_per_bar) - beats_per_bar))* BBT_Time::ticks_per_beat
+ : BBT_Time::ticks_per_beat );
while (result.ticks >= ticks_at_beat) {
result.beats++;
metric = metric_at(result); // maybe there is a meter change
beats_per_bar = metric.meter().beats_per_bar();
}
- ticks_at_beat= (uint32_t) ( result.beats == ceil(beats_per_bar) ?
- (1 - (ceil(beats_per_bar) - beats_per_bar) ) * Meter::ticks_per_beat
- : Meter::ticks_per_beat);
-
+ ticks_at_beat= (uint32_t) (result.beats == ceil(beats_per_bar) ?
+ (1 - (ceil(beats_per_bar) - beats_per_bar) ) * BBT_Time::ticks_per_beat
+ : BBT_Time::ticks_per_beat);
}
} else {
uint32_t b = bbt.beats;
- /* count beats */
- while( b > when.beats ) {
-
- result.bars = max(1U,result.bars-- ) ;
+ /* count beats */
+ while (b > when.beats) {
+ --result.bars;
+ result.bars = max(1U, result.bars);
metric = metric_at(result); // maybe there is a meter change
beats_per_bar = metric.meter().beats_per_bar();
if (b >= ceil(beats_per_bar)) {
-
b -= (uint32_t) ceil(beats_per_bar);
} else {
b = (uint32_t) ceil(beats_per_bar) - b + when.beats ;
}
result.beats = when.beats - b;
- /*count ticks */
+ /* count ticks */
if (bbt.ticks <= when.ticks) {
result.ticks = when.ticks - bbt.ticks;
} else {
- uint32_t ticks_at_beat= (uint32_t) Meter::ticks_per_beat;
+ uint32_t ticks_at_beat= (uint32_t) BBT_Time::ticks_per_beat;
uint32_t t = bbt.ticks - when.ticks;
do {
if (result.beats == 1) {
- result.bars = max(1U, result.bars-- ) ;
+ --result.bars;
+ result.bars = max(1U, result.bars) ;
metric = metric_at(result); // maybe there is a meter change
beats_per_bar = metric.meter().beats_per_bar();
result.beats = (uint32_t) ceil(beats_per_bar);
- ticks_at_beat = (uint32_t) ((1 - (ceil(beats_per_bar) - beats_per_bar)) * Meter::ticks_per_beat) ;
+ ticks_at_beat = (uint32_t) ((1 - (ceil(beats_per_bar) - beats_per_bar)) * BBT_Time::ticks_per_beat) ;
} else {
- result.beats --;
- ticks_at_beat = (uint32_t) Meter::ticks_per_beat;
+ --result.beats;
+ ticks_at_beat = (uint32_t) BBT_Time::ticks_per_beat;
}
if (t <= ticks_at_beat) {
}
- if (dir < 0 ) {
- frames = count_frames_between( result,when);
+ if (dir < 0) {
+ frames = count_frames_between(result, when);
} else {
frames = count_frames_between(when,result);
}
-nframes64_t
-TempoMap::round_to_bar (nframes64_t fr, int dir)
+framepos_t
+TempoMap::round_to_bar (framepos_t fr, int dir)
{
- {
- Glib::RWLock::ReaderLock lm (lock);
+ {
+ Glib::RWLock::ReaderLock lm (lock);
return round_to_type (fr, dir, Bar);
}
}
-nframes64_t
-TempoMap::round_to_beat (nframes64_t fr, int dir)
+framepos_t
+TempoMap::round_to_beat (framepos_t fr, int dir)
{
- {
- Glib::RWLock::ReaderLock lm (lock);
+ {
+ Glib::RWLock::ReaderLock lm (lock);
return round_to_type (fr, dir, Beat);
}
}
-nframes64_t
-TempoMap::round_to_beat_subdivision (nframes64_t fr, int sub_num, int dir)
+framepos_t
+TempoMap::round_to_beat_subdivision (framepos_t fr, int sub_num, int dir)
{
BBT_Time the_beat;
uint32_t ticks_one_half_subdivisions_worth;
bbt_time(fr, the_beat);
- ticks_one_subdivisions_worth = (uint32_t)Meter::ticks_per_beat / sub_num;
+ ticks_one_subdivisions_worth = (uint32_t)BBT_Time::ticks_per_beat / sub_num;
ticks_one_half_subdivisions_worth = ticks_one_subdivisions_worth / 2;
if (dir > 0) {
difference = mod;
}
- try {
- the_beat = bbt_subtract (the_beat, BBT_Time (0, 0, difference));
- } catch (...) {
- /* can't go backwards from wherever pos is, so just return it */
- return fr;
- }
-
+ try {
+ the_beat = bbt_subtract (the_beat, BBT_Time (0, 0, difference));
+ } catch (...) {
+ /* can't go backwards from wherever pos is, so just return it */
+ return fr;
+ }
} else {
/* round to nearest */
return frame_time (the_beat);
}
-nframes64_t
-TempoMap::round_to_type (nframes64_t frame, int dir, BBTPointType type)
+framepos_t
+TempoMap::round_to_type (framepos_t frame, int dir, BBTPointType type)
{
TempoMetric metric = metric_at (frame);
BBT_Time bbt;
float midbar_ticks;
midbar_beats = metric.meter().beats_per_bar() / 2 + 1;
- midbar_ticks = Meter::ticks_per_beat * fmod (midbar_beats, 1.0f);
+ midbar_ticks = BBT_Time::ticks_per_beat * fmod (midbar_beats, 1.0f);
midbar_beats = floor (midbar_beats);
BBT_Time midbar (bbt.bars, lrintf (midbar_beats), lrintf (midbar_ticks));
/* "true" rounding */
/* round to nearest beat */
- if (bbt.ticks >= (Meter::ticks_per_beat/2)) {
+ if (bbt.ticks >= (BBT_Time::ticks_per_beat/2)) {
try {
bbt = bbt_add (bbt, one_beat, metric);
}
TempoMap::BBTPointList *
-TempoMap::get_points (nframes64_t lower, nframes64_t upper) const
+TempoMap::get_points (framepos_t lower, framepos_t upper) const
{
Metrics::const_iterator i;
double delta_bars;
double delta_beats;
double dummy;
- nframes64_t limit;
+ framepos_t limit;
meter = &first_meter ();
tempo = &first_tempo ();
if (beat == 1) {
if (current >= lower) {
// cerr << "Add Bar at " << bar << "|1" << " @ " << current << endl;
- points->push_back (BBTPoint (*meter, *tempo,(nframes64_t)rint(current), Bar, bar, 1));
+ points->push_back (BBTPoint (*meter, *tempo,(framepos_t)rint(current), Bar, bar, 1));
}
}
beat_frame = current;
- while (beat <= ceil( beats_per_bar) && beat_frame < limit) {
+ while (beat <= ceil(beats_per_bar) && beat_frame < limit) {
if (beat_frame >= lower) {
// cerr << "Add Beat at " << bar << '|' << beat << " @ " << beat_frame << endl;
- points->push_back (BBTPoint (*meter, *tempo, (nframes64_t) rint(beat_frame), Beat, bar, beat));
+ points->push_back (BBTPoint (*meter, *tempo, (framepos_t) rint(beat_frame), Beat, bar, beat));
}
beat_frame += beat_frames;
current+= beat_frames;
}
const TempoSection&
-TempoMap::tempo_section_at (nframes64_t frame)
+TempoMap::tempo_section_at (framepos_t frame) const
{
Glib::RWLock::ReaderLock lm (lock);
- Metrics::iterator i;
+ Metrics::const_iterator i;
TempoSection* prev = 0;
for (i = metrics->begin(); i != metrics->end(); ++i) {
}
const Tempo&
-TempoMap::tempo_at (nframes64_t frame) const
+TempoMap::tempo_at (framepos_t frame) const
{
TempoMetric m (metric_at (frame));
return m.tempo();
const Meter&
-TempoMap::meter_at (nframes64_t frame) const
+TempoMap::meter_at (framepos_t frame) const
{
TempoMetric m (metric_at (frame));
return m.meter();
XMLNode *root = new XMLNode ("TempoMap");
{
- Glib::RWLock::ReaderLock lm (lock);
+ Glib::RWLock::ReaderLock lm (lock);
for (i = metrics->begin(); i != metrics->end(); ++i) {
- root->add_child_nocopy ((*i)->get_state());
+ root->add_child_nocopy ((*i)->get_state());
}
}
}
void
-TempoMap::insert_time (nframes64_t where, nframes64_t amount)
+TempoMap::insert_time (framepos_t where, framecnt_t amount)
{
for (Metrics::iterator i = metrics->begin(); i != metrics->end(); ++i) {
if ((*i)->frame() >= where) {
BBT_Time op = increment; /* argument is const, but we need to modify it */
uint32_t ticks = result.ticks + op.ticks;
- if (ticks >= Meter::ticks_per_beat) {
+ if (ticks >= BBT_Time::ticks_per_beat) {
op.beats++;
- result.ticks = ticks % (uint32_t) Meter::ticks_per_beat;
+ result.ticks = ticks % (uint32_t) BBT_Time::ticks_per_beat;
} else {
result.ticks += op.ticks;
}
if (op.ticks > result.ticks) {
/* subtract an extra beat later; meanwhile set ticks to the right "carry" value */
op.beats++;
- result.ticks = Meter::ticks_per_beat - (op.ticks - result.ticks);
+ result.ticks = BBT_Time::ticks_per_beat - (op.ticks - result.ticks);
} else {
result.ticks -= op.ticks;
}
return result;
}
+/** Add the BBT interval op to pos and return the result */
+framepos_t
+TempoMap::framepos_plus_bbt (framepos_t pos, BBT_Time op) const
+{
+ /* XXX: this is a little inaccurate as small errors are introduced
+ every time a probably-fractional product of something and
+ frames_per_beat is rounded. Other errors can be introduced
+ by op.ticks' integer nature.
+ */
+
+ Metrics::const_iterator i;
+ const MeterSection* meter;
+ const MeterSection* m;
+ const TempoSection* tempo;
+ const TempoSection* t;
+ framecnt_t frames_per_beat;
+
+ meter = &first_meter ();
+ tempo = &first_tempo ();
+
+ assert (meter);
+ assert (tempo);
+
+ /* find the starting metrics for tempo & meter */
+
+ for (i = metrics->begin(); i != metrics->end(); ++i) {
+
+ if ((*i)->frame() > pos) {
+ break;
+ }
+
+ if ((t = dynamic_cast<const TempoSection*>(*i)) != 0) {
+ tempo = t;
+ } else if ((m = dynamic_cast<const MeterSection*>(*i)) != 0) {
+ meter = m;
+ }
+ }
+
+ /* We now have:
+
+ meter -> the Meter for "pos"
+ tempo -> the Tempo for "pos"
+ i -> for first new metric after "pos", possibly metrics->end()
+ */
+
+ /* now comes the complicated part. we have to add one beat a time,
+ checking for a new metric on every beat.
+ */
+
+ frames_per_beat = tempo->frames_per_beat (_frame_rate, *meter);
+
+ while (op.bars) {
+
+ pos += llrint (frames_per_beat * meter->beats_per_bar());
+ op.bars--;
+
+ /* check if we need to use a new metric section: has adding frames moved us
+ to or after the start of the next metric section? in which case, use it.
+ */
+
+ if (i != metrics->end()) {
+ if ((*i)->frame() <= pos) {
+
+ if ((t = dynamic_cast<const TempoSection*>(*i)) != 0) {
+ tempo = t;
+ } else if ((m = dynamic_cast<const MeterSection*>(*i)) != 0) {
+ meter = m;
+ }
+ ++i;
+ frames_per_beat = tempo->frames_per_beat (_frame_rate, *meter);
+
+ }
+ }
+
+ }
+
+ while (op.beats) {
+
+ /* given the current meter, have we gone past the end of the bar ? */
+
+ pos += frames_per_beat;
+ op.beats--;
+
+ /* check if we need to use a new metric section: has adding frames moved us
+ to or after the start of the next metric section? in which case, use it.
+ */
+
+ if (i != metrics->end()) {
+ if ((*i)->frame() <= pos) {
+
+ if ((t = dynamic_cast<const TempoSection*>(*i)) != 0) {
+ tempo = t;
+ } else if ((m = dynamic_cast<const MeterSection*>(*i)) != 0) {
+ meter = m;
+ }
+ ++i;
+ frames_per_beat = tempo->frames_per_beat (_frame_rate, *meter);
+ }
+ }
+ }
+
+ if (op.ticks) {
+ if (op.ticks >= BBT_Time::ticks_per_beat) {
+ pos += frames_per_beat;
+ pos += llrint (frames_per_beat * ((op.ticks % (uint32_t) BBT_Time::ticks_per_beat) / (double) BBT_Time::ticks_per_beat));
+ } else {
+ pos += llrint (frames_per_beat * (op.ticks / (double) BBT_Time::ticks_per_beat));
+ }
+ }
+
+ return pos;
+}
+
+/** Count the number of beats that are equivalent to distance when starting at pos */
+double
+TempoMap::framewalk_to_beats (framepos_t pos, framecnt_t distance) const
+{
+ Metrics::const_iterator i;
+ double beats = 0;
+ const MeterSection* meter;
+ const MeterSection* m;
+ const TempoSection* tempo;
+ const TempoSection* t;
+ double frames_per_beat;
+
+ double ddist = distance;
+ double dpos = pos;
+
+ meter = &first_meter ();
+ tempo = &first_tempo ();
+
+ assert (meter);
+ assert (tempo);
+
+ /* find the starting metrics for tempo & meter */
+
+ for (i = metrics->begin(); i != metrics->end(); ++i) {
+
+ if ((*i)->frame() > pos) {
+ break;
+ }
+
+ if ((t = dynamic_cast<const TempoSection*>(*i)) != 0) {
+ tempo = t;
+ } else if ((m = dynamic_cast<const MeterSection*>(*i)) != 0) {
+ meter = m;
+ }
+ }
+
+ /* We now have:
+
+ meter -> the Meter for "pos"
+ tempo -> the Tempo for "pos"
+ i -> for first new metric after "pos", possibly metrics->end()
+ */
+
+ /* now comes the complicated part. we have to add one beat a time,
+ checking for a new metric on every beat.
+ */
+
+ frames_per_beat = tempo->frames_per_beat (_frame_rate, *meter);
+
+ while (ddist > 0) {
+
+ /* if we're nearly at the end, but have a fractional beat left,
+ compute the fraction and then its all over
+ */
+
+ if (ddist < frames_per_beat) {
+ beats += ddist / frames_per_beat;
+ break;
+ }
+
+ /* walk one beat */
+
+ ddist -= frames_per_beat;
+ dpos += frames_per_beat;
+ beats += 1.0;
+
+ /* check if we need to use a new metric section: has adding frames moved us
+ to or after the start of the next metric section? in which case, use it.
+ */
+
+ if (i != metrics->end()) {
+ if ((*i)->frame() <= (framepos_t) dpos) {
+
+ if ((t = dynamic_cast<const TempoSection*>(*i)) != 0) {
+ tempo = t;
+ } else if ((m = dynamic_cast<const MeterSection*>(*i)) != 0) {
+ meter = m;
+ }
+ ++i;
+ frames_per_beat = tempo->frames_per_beat (_frame_rate, *meter);
+ }
+ }
+
+ }
+
+ return beats;
+}
+
+
/** Compare the time of this with that of another MetricSection.
* @param with_bbt True to compare using ::start(), false to use ::frame().
* @return -1 for less than, 0 for equal, 1 for greater than.