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livetrax/libs/temporal/bbt_time.cc

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1.6 KiB
C++

/*
* Copyright (C) 2017 Paul Davis <paul@linuxaudiosystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <cmath>
#include <cassert>
#include "temporal/bbt_time.h"
using namespace Timecode;
/* This defines the smallest division of a "beat".
The number is intended to have as many integer factors as possible so that
1/Nth divisions are integer numbers of ticks.
1920 has many factors, though going up to 3840 gets a couple more.
This needs to match Temporal::Beats::PPQN
*/
const double BBT_Time::ticks_per_beat = 1920.0;
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 = lrint (floor (dbeats));
ticks = lrint (floor (BBT_Time::ticks_per_beat * fmod (dbeats, 1.0)));
}