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livetrax/libs/temporal/temporal/bbt_time.h

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/*
* 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.
*/
#ifndef __timecode_bbt_time_h__
#define __timecode_bbt_time_h__
#include <ostream>
#include <stdint.h>
#include <iomanip>
#include <exception>
#include "temporal/visibility.h"
namespace Timecode {
/** Bar, Beat, Tick Time (i.e. Tempo-Based Time) */
struct LIBTEMPORAL_API BBT_Time
{
static const double ticks_per_beat;
/* note that it is illegal for BBT_Time to have bars==0 or
* beats==0. The "neutral" or "default" value is 1|1|0
*/
int32_t bars;
int32_t beats;
int32_t ticks;
struct IllegalBBTTimeException : public std::exception {
virtual const char* what() const throw() { return "illegal BBT time (bars or beats were zero)"; }
};
BBT_Time () : bars (1), beats (1), ticks (0) {}
BBT_Time (int32_t ba, uint32_t be, uint32_t t) : bars (ba), beats (be), ticks (t) { if (!bars || !beats) { throw IllegalBBTTimeException(); } }
bool operator< (const BBT_Time& other) const {
return bars < other.bars ||
(bars == other.bars && beats < other.beats) ||
(bars == other.bars && beats == other.beats && ticks < other.ticks);
}
bool operator<= (const BBT_Time& other) const {
return bars < other.bars ||
(bars <= other.bars && beats <= other.beats) ||
(bars <= other.bars && beats <= other.beats && ticks <= other.ticks);
}
bool operator> (const BBT_Time& other) const {
return bars > other.bars ||
(bars == other.bars && beats > other.beats) ||
(bars == other.bars && beats == other.beats && ticks > other.ticks);
}
bool operator>= (const BBT_Time& other) const {
return bars > other.bars ||
(bars >= other.bars && beats >= other.beats) ||
(bars >= other.bars && beats >= other.beats && ticks >= other.ticks);
}
bool operator== (const BBT_Time& other) const {
return bars == other.bars && beats == other.beats && ticks == other.ticks;
}
bool operator!= (const BBT_Time& other) const {
return bars != other.bars || beats != other.beats || ticks != other.ticks;
}
/* it would be nice to provide operator+(BBT_Time const&) and
* operator-(BBT_Time const&) but this math requires knowledge of the
* meter (time signature) used to define 1 bar, and so cannot be
* carried out with only two BBT_Time values.
*/
BBT_Time round_to_beat () const { return ticks >= (ticks_per_beat/2) ? BBT_Time (bars, beats+1, 0) : BBT_Time (bars, beats, 0); }
BBT_Time round_down_to_beat () const { return BBT_Time (bars, beats, 0); }
BBT_Time round_up_to_beat () const { return ticks ? BBT_Time (bars, beats+1, 0) : *this; }
/* cannot implement round_to_bar() without knowing meter (time
* signature) information.
*/
};
struct LIBTEMPORAL_API BBT_Offset
{
int32_t bars;
int32_t beats;
int32_t ticks;
/* this is a variant for which bars==0 and/or beats==0 is legal. It
* represents an offset from a given BBT_Time and is used when doing
* add/subtract operations on a BBT_Time.
*/
BBT_Offset () : bars (0), beats (0), ticks (0) {}
BBT_Offset (int32_t ba, uint32_t be, uint32_t t) : bars (ba), beats (be), ticks (t) {}
BBT_Offset (BBT_Time const & bbt) : bars (bbt.bars), beats (bbt.beats), ticks (bbt.ticks) {}
BBT_Offset (double beats);
};
}
inline std::ostream&
operator<< (std::ostream& o, const Timecode::BBT_Time& bbt)
{
o << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
return o;
}
inline std::ostream&
operator<< (std::ostream& o, const Timecode::BBT_Offset& bbt)
{
o << bbt.bars << '|' << bbt.beats << '|' << bbt.ticks;
return o;
}
inline std::ostream&
print_padded (std::ostream& o, const Timecode::BBT_Time& bbt)
{
o << std::setfill ('0') << std::right
<< std::setw (3) << bbt.bars << "|"
<< std::setw (2) << bbt.beats << "|"
<< std::setw (4) << bbt.ticks;
return o;
}
#endif /* __timecode_bbt_time_h__ */