13
0
livetrax/libs/temporal/bbt_time.cc
Paul Davis 14e7f62891 fix BBT_Time::round_up_to_beat_div() (partially)
Math is now correct for cases where "beats" in BBT are quarters.
Incorrect for others
2023-09-22 22:54:37 -06:00

149 lines
3.3 KiB
C++

/*
Copyright (C) 2002-2010 Paul Davis
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <cmath>
#include <cassert>
#include "temporal/bbt_time.h"
#include "temporal/bbt_argument.h"
using namespace Temporal;
int64_t
BBT_Time::as_integer () const
{
/* up to 256 beats in a bar, 4095 ticks in a beat,
and whatever is left for bars (a lot!)
*/
return (((int64_t) bars)<<20)|(beats<<12)|ticks;
}
BBT_Time
BBT_Time::from_integer (int64_t v)
{
int32_t B = v>>20;
int32_t b = (v>>12) & 0xff;
int32_t t= v & 0xfff;
return BBT_Time (B, b, t);
}
BBT_Time
BBT_Time::round_up_to_bar() const
{
if (ticks == 0 && beats == 1) {
return *this;
}
BBT_Time b = round_up_to_beat ();
if (b.beats > 1) {
b.bars += 1;
b.beats = 1;
}
return b;
}
BBT_Time
BBT_Time::round_up_to_beat_div (int beat_div) const
{
/* XXX this doesn't work where "beats" are not quarters, because
we could have B|b|0 and this is not on a beat_div, even though it is
an integer beat position (think triplets.
*/
const int32_t div_ticks = ticks_per_beat / beat_div;
int32_t rounded_up = ticks + div_ticks - 1;
rounded_up -= rounded_up % div_ticks;
if (rounded_up == ticks_per_beat) {
return BBT_Time (bars, beats+1, 0);
}
return BBT_Time (bars, beats, rounded_up);
}
BBT_Offset::BBT_Offset (double dbeats)
{
/* NOTE: this does not construct a BBT time in a canonical form,
in that beats may be a very large number, and bars will
always be zero. Hence ... it's a BBT_Offset
*/
assert (dbeats >= 0);
bars = 0;
beats = (int32_t) lrint (floor (dbeats));
ticks = (int32_t) lrint (floor (Temporal::ticks_per_beat * fmod (dbeats, 1.0)));
}
std::ostream&
std::operator<< (std::ostream& o, Temporal::BBT_Time const & bbt)
{
o << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
return o;
}
std::ostream&
std::operator<< (std::ostream& o, const Temporal::BBT_Offset& bbt)
{
o << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
return o;
}
std::istream&
std::operator>>(std::istream& i, Temporal::BBT_Offset& bbt)
{
int32_t B, b, t;
char skip_pipe_char;
i >> B;
i >> skip_pipe_char;
i >> b;
i >> skip_pipe_char;
i >> t;
bbt = Temporal::BBT_Offset (B, b, t);
return i;
}
std::istream&
std::operator>>(std::istream& i, Temporal::BBT_Time& bbt)
{
int32_t B, b, t;
char skip_pipe_char;
i >> B;
i >> skip_pipe_char;
i >> b;
i >> skip_pipe_char;
i >> t;
bbt = Temporal::BBT_Time (B, b, t);
return i;
}
/* define this here to avoid adding another .cc file for just this operator */
std::ostream&
std::operator<< (std::ostream& o, Temporal::BBT_Argument const & bbt)
{
o << '@' << bbt.reference() << ':' << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
return o;
}