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next iteration of tempo map stuff - fixes off-by-one issues with bar offset<->beat math

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git-svn-id: svn://localhost/ardour2/branches/3.0@11109 d708f5d6-7413-0410-9779-e7cbd77b26cf
This commit is contained in:
Paul Davis 2011-12-29 21:34:46 +00:00
parent c19121459b
commit 07750ccb32
1 changed files with 77 additions and 39 deletions
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116
libs/ardour/tempo.cc
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@ -157,7 +157,7 @@ void
TempoSection::update_bar_offset_from_bbt (const Meter& m)
{
_bar_offset = ((double) (start().beats - 1) + (start().ticks/Timecode::BBT_Time::ticks_per_bar_division)) /
m.divisions_per_bar();
(m.divisions_per_bar() - 1);
DEBUG_TRACE (DEBUG::TempoMath, string_compose ("Tempo set bar offset to %1 from %2 w/%3\n", _bar_offset, start(), m.divisions_per_bar()));
}
@ -173,13 +173,19 @@ TempoSection::update_bbt_time_from_bar_offset (const Meter& meter)
}
new_start.bars = start().bars;
double ticks = BBT_Time::ticks_per_bar_division * (_bar_offset * (meter.divisions_per_bar() - 1));
new_start.beats = (uint32_t) floor(ticks/BBT_Time::ticks_per_bar_division);
new_start.ticks = (uint32_t) fmod (ticks, BBT_Time::ticks_per_bar_division);
DEBUG_TRACE (DEBUG::TempoMath, string_compose ("from bar offset %1 and dpb %2, ticks = %3->%4 beats = %5\n",
_bar_offset, meter.divisions_per_bar(), ticks, new_start.ticks, new_start.beats));
/* remember the 1-based counting properties of beats */
new_start.beats = 1 + (uint32_t) floor (_bar_offset * meter.divisions_per_bar());
new_start.ticks = (uint32_t) floor (BBT_Time::ticks_per_bar_division *
((_bar_offset * meter.divisions_per_bar()) - (new_start.beats-1)));
DEBUG_TRACE (DEBUG::TempoMath, string_compose ("tempo updated BBT time to %1 from bar offset %2\n", new_start, _bar_offset));
new_start.beats += 1;
DEBUG_TRACE (DEBUG::TempoMath, string_compose ("tempo updated BBT time to %1 from bar offset %2 w/dpb = %3\n", new_start, _bar_offset, meter.divisions_per_bar()));
set_start (new_start);
}
@ -1576,45 +1582,77 @@ TempoMap::get_points (framepos_t lower, framepos_t upper) const
this could be be because we hit "upper"
or a new metric section.
meter sections are always at the start
of a measure. put differently, if a meter
indicates N divisions per bar, the next
meter must be a multiple of N divisions
after it.
so, we've hit a tempo section, which may or
may not be precisely on a beat.
*/
if (next_metric != metrics->end() && limit == (*next_metric)->frame() && ((ts = dynamic_cast<TempoSection*> (*next_metric)) != 0) && ts->start().ticks != 0) {
if (next_metric != metrics->end() && limit == (*next_metric)->frame()) {
/* compute current at the *next* beat,
using the tempo section we just
bumped into.
also, avoid resetting it to position
of the next metric section as we
move to that below.
*/
reset_current_to_metric_section = false;
/* recompute how many frames per
* division using the tempo we've just
* found
/* we bumped into a new metric
* section. meter sections are always
* at bar boundaries, but tempo
* sections can begin anywhere and need
* special handling if they are not on
* a beat boundary.
*/
double next_beat_frames = meter->frames_per_division (*ts,_frame_rate);
DEBUG_TRACE (DEBUG::TempoMath, string_compose ("bumped into non-beat-aligned tempo metric at %1 = %2, adjust next beat using %3\n",
(*next_metric)->start(), (*next_metric)->frame(), ts->bar_offset()));
current -= beat_frames;
current += (ts->bar_offset() * beat_frames) + ((1.0 - ts->bar_offset()) * next_beat_frames);
}
DEBUG_TRACE (DEBUG::TempoMath, string_compose ("stopped at metric at %1 @ 2\n", (*next_metric)->start(), (*next_metric)->frame()));
if (((ts = dynamic_cast<TempoSection*> (*next_metric)) != 0) && ts->start().ticks != 0) {
} else if ((beat > max_divs) || (next_metric != metrics->end() && dynamic_cast<MeterSection*>(*next_metric))) {
/* compute current at the *next* beat,
using the tempo section we just
bumped into.
*/
/* recompute how many frames per
* division using the tempo we've just
* found
*/
double next_beat_frames = meter->frames_per_division (*ts,_frame_rate);
DEBUG_TRACE (DEBUG::TempoMath, string_compose ("bumped into non-beat-aligned tempo metric at %1 = %2, adjust next beat using %3\n",
(*next_metric)->start(), (*next_metric)->frame(), ts->bar_offset()));
current -= beat_frames;
current += (ts->bar_offset() * beat_frames) + ((1.0 - ts->bar_offset()) * next_beat_frames);
/* avoid resetting current to position
of the next metric section as we
iterate through "metrics"
further on below.
*/
reset_current_to_metric_section = false;
} else if (dynamic_cast<MeterSection*> (*next_metric)) {
/* we hit a new meter section. bump the
* bar and return to beat 1
*/
// bar++;
// beat = 1;
// bar_adjusted = true;
}
} else {
/* we hit either:
- the end of the requested range
- a tempo mark that is precisely on beat
in the first case, we'll exit from
the outer loop soon.
in the second case, nothing special
is required.
*/
}
} else if ((beat > max_divs) || (next_metric != metrics->end() && dynamic_cast<MeterSection*>(*next_metric))) {
/* we've arrived at either the end of a bar or
a new **meter** marker (not tempo marker).