Paul Davis
14e7f62891
Math is now correct for cases where "beats" in BBT are quarters. Incorrect for others
149 lines
3.3 KiB
C++
149 lines
3.3 KiB
C++
/*
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Copyright (C) 2002-2010 Paul Davis
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at your
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option) any later version.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <cmath>
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#include <cassert>
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#include "temporal/bbt_time.h"
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#include "temporal/bbt_argument.h"
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using namespace Temporal;
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int64_t
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BBT_Time::as_integer () const
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{
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/* up to 256 beats in a bar, 4095 ticks in a beat,
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and whatever is left for bars (a lot!)
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*/
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return (((int64_t) bars)<<20)|(beats<<12)|ticks;
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}
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BBT_Time
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BBT_Time::from_integer (int64_t v)
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{
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int32_t B = v>>20;
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int32_t b = (v>>12) & 0xff;
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int32_t t= v & 0xfff;
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return BBT_Time (B, b, t);
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}
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BBT_Time
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BBT_Time::round_up_to_bar() const
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{
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if (ticks == 0 && beats == 1) {
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return *this;
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}
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BBT_Time b = round_up_to_beat ();
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if (b.beats > 1) {
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b.bars += 1;
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b.beats = 1;
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}
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return b;
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}
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BBT_Time
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BBT_Time::round_up_to_beat_div (int beat_div) const
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{
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/* XXX this doesn't work where "beats" are not quarters, because
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we could have B|b|0 and this is not on a beat_div, even though it is
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an integer beat position (think triplets.
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*/
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const int32_t div_ticks = ticks_per_beat / beat_div;
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int32_t rounded_up = ticks + div_ticks - 1;
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rounded_up -= rounded_up % div_ticks;
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if (rounded_up == ticks_per_beat) {
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return BBT_Time (bars, beats+1, 0);
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}
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return BBT_Time (bars, beats, rounded_up);
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}
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BBT_Offset::BBT_Offset (double dbeats)
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{
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/* NOTE: this does not construct a BBT time in a canonical form,
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in that beats may be a very large number, and bars will
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always be zero. Hence ... it's a BBT_Offset
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*/
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assert (dbeats >= 0);
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bars = 0;
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beats = (int32_t) lrint (floor (dbeats));
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ticks = (int32_t) lrint (floor (Temporal::ticks_per_beat * fmod (dbeats, 1.0)));
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}
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std::ostream&
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std::operator<< (std::ostream& o, Temporal::BBT_Time const & bbt)
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{
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o << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
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return o;
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}
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std::ostream&
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std::operator<< (std::ostream& o, const Temporal::BBT_Offset& bbt)
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{
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o << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
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return o;
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}
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std::istream&
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std::operator>>(std::istream& i, Temporal::BBT_Offset& bbt)
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{
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int32_t B, b, t;
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char skip_pipe_char;
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i >> B;
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i >> skip_pipe_char;
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i >> b;
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i >> skip_pipe_char;
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i >> t;
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bbt = Temporal::BBT_Offset (B, b, t);
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return i;
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}
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std::istream&
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std::operator>>(std::istream& i, Temporal::BBT_Time& bbt)
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{
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int32_t B, b, t;
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char skip_pipe_char;
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i >> B;
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i >> skip_pipe_char;
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i >> b;
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i >> skip_pipe_char;
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i >> t;
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bbt = Temporal::BBT_Time (B, b, t);
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return i;
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}
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/* define this here to avoid adding another .cc file for just this operator */
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std::ostream&
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std::operator<< (std::ostream& o, Temporal::BBT_Argument const & bbt)
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{
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o << '@' << bbt.reference() << ':' << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
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return o;
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}
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