ardour/libs/temporal/bbt_time.cc

51 lines
1.5 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"
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)));
}