bbt_time.h

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/*
  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.
*/
 
#ifndef __libtemporal_bbt_time_h__
#define __libtemporal_bbt_time_h__
 
#include <ostream>
#include <istream>
#include <sstream>
#include <stdint.h>
#include <iomanip>
#include <exception>
#include <cmath>
#include <limits>
#include <cstdio>
 
#include "pbd/failed_constructor.h"
#include "pbd/string_convert.h"
 
#include "temporal/visibility.h"
#include "temporal/types.h"
 
namespace Temporal {
 
struct IllegalBBTTimeException : public std::exception {
        virtual const char* what() const throw() { return "illegal BBT time (bars or beats were zero, or ticks was too large)"; }
};
 
struct BBT_Offset;
 
struct LIBTEMPORAL_API BBT_Time
{
        /* 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;
 
        int64_t as_integer() const;
        static BBT_Time from_integer (int64_t);
 
        bool is_bar() const { return beats == 1 && ticks == 0; }
        bool is_beat() const { return ticks == 0; }
 
        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;
        }
 
        bool operator<  (const BBT_Offset& other) const;
        bool operator<= (const BBT_Offset& other) const;
        bool operator>  (const BBT_Offset& other) const;
        bool operator>= (const BBT_Offset& other) const;
        bool operator== (const BBT_Offset& other) const;
        bool operator!= (const BBT_Offset& other) const;
 
        /* it would be nice to provide +,-,* and / operators for BBT_Time 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; }
        BBT_Time round_up_to_beat_div (int beat_div) const;
 
        /* cannot implement round_to_bar() without knowing meter (time
         * signature) information, since it requires knowing how many beats
         * are in a bar, in order to decide if we are closer to the previous or
         * next bar time.
         */
 
        BBT_Time round_up_to_bar () const;
        BBT_Time round_down_to_bar () const { return BBT_Time (bars, 1, 0); }
        BBT_Time next_bar () const { return (bars == -1) ? BBT_Time (1, 1, 0) : BBT_Time (bars+1, 1, 0); }
        BBT_Time prev_bar () const { return (bars == 1)  ? BBT_Time (-1, 1, 0) : BBT_Time (bars-1, 1, 0); }
 
        void print_padded (std::ostream& o) const {
                o << std::setfill ('0') << std::right
                  << std::setw (3) << bars << "|"
                  << std::setw (2) << beats << "|"
                  << std::setw (4) << ticks;
        }
 
        std::string str () const {
                std::ostringstream os;
                os << bars << '|' << beats << '|' << ticks;
                return os.str ();
        }
 
};
 
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) {}
        explicit BBT_Offset (double beats);
 
        /* unlike BBT_Time, we can define +,-,* and / operators for BBT_Offset
         * because there is no requirement that the result is "well-formed" or
         * reflect the structure of a tempo map. It is just as valid to talk
         * about an offset of 18 beats as an offset of 4 bars and 2 beats.
         */
 
        BBT_Offset operator+(const BBT_Offset& other) const {
                return BBT_Offset (bars+other.bars, beats+other.beats, ticks+other.ticks);
        }
 
        BBT_Offset operator-() const {
                return BBT_Offset (-bars, -beats, -ticks);
        }
 
        BBT_Offset operator-(const BBT_Offset& other) const {
                return BBT_Offset (bars-other.bars, beats-other.beats, ticks-other.ticks);
        }
 
        BBT_Offset & operator+=(const BBT_Offset& other) {
                bars += other.bars;
                beats += other.beats;
                ticks += other.ticks;
                return *this;
        }
 
        BBT_Offset & operator-=(const BBT_Offset& other) {
                bars -= other.bars;
                beats -= other.beats;
                ticks -= other.ticks;
                return *this;
        }
 
        BBT_Offset & operator*=(int factor) {
                bars *= factor;
                beats *= factor;
                ticks *= factor;
                return *this;
        }
 
        BBT_Offset & operator*=(double factor) {
                bars = (int32_t) lrint (bars * factor);
                beats = (int32_t) lrint (beats * factor);
                ticks = (int32_t) lrint (ticks * factor);
                return *this;
        }
 
        BBT_Offset & operator/=(int factor) {
                bars /= factor;
                beats /= factor;
                ticks /= factor;
                return *this;
        }
 
        BBT_Offset & operator/=(double factor) {
                bars = (int32_t) lrint (bars / factor);
                beats = (int32_t) lrint (beats / factor);
                ticks = (int32_t) lrint (ticks / factor);
                return *this;
        }
 
        bool operator< (const BBT_Offset& 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_Offset& 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_Offset& 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_Offset& 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_Offset& other) const {
                return bars == other.bars && beats == other.beats && ticks == other.ticks;
        }
 
        bool operator!= (const BBT_Offset& other) const {
                return bars != other.bars || beats != other.beats || ticks != other.ticks;
        }
 
        operator bool() const {
                return bars == 0 && beats == 0 && ticks == 0;
        }
 
        std::string str () const {
                std::ostringstream os;
                os << bars << '|' << beats << '|' << ticks;
                return os.str ();
        }
};
 
inline BBT_Offset LIBTEMPORAL_API bbt_delta (Temporal::BBT_Time const & a, Temporal::BBT_Time const & b) {
        return Temporal::BBT_Offset (a.bars - b.bars, a.beats - b.beats, a.ticks - b.ticks);
}
 
inline bool
BBT_Time::operator< (const BBT_Offset& other) const
{
        return bars < other.bars ||
                      (bars == other.bars && beats < other.beats) ||
                (bars == other.bars && beats == other.beats && ticks < other.ticks);
}
 
inline bool
BBT_Time::operator<= (const BBT_Offset& other) const
{
        return bars < other.bars ||
                      (bars <= other.bars && beats <= other.beats) ||
                (bars <= other.bars && beats <= other.beats && ticks <= other.ticks);
}
 
inline bool
BBT_Time::operator> (const BBT_Offset& other) const
{
        return bars > other.bars ||
                (bars == other.bars && beats > other.beats) ||
                (bars == other.bars && beats == other.beats && ticks > other.ticks);
}
 
inline bool
BBT_Time::operator>= (const BBT_Offset& other) const
{
        return bars > other.bars ||
                (bars >= other.bars && beats >= other.beats) ||
                (bars >= other.bars && beats >= other.beats && ticks >= other.ticks);
}
 
inline bool
BBT_Time::operator== (const BBT_Offset& other) const
{
        return bars == other.bars && beats == other.beats && ticks == other.ticks;
}
 
inline bool
BBT_Time::operator!= (const BBT_Offset& other) const
{
        return bars != other.bars || beats != other.beats || ticks != other.ticks;
}
 
} /* end of namespace Temporal */
 
/* Putting these into std:: seems wrong, but g++ is unable to find them
 * otherwise
 */
 
namespace std {
 
LIBTEMPORAL_API std::ostream& operator<< (std::ostream& o, Temporal::BBT_Time const & bbt);
LIBTEMPORAL_API std::ostream& operator<< (std::ostream& o, Temporal::BBT_Offset const & bbt);
LIBTEMPORAL_API std::istream& operator>> (std::istream& i, Temporal::BBT_Time& bbt);
LIBTEMPORAL_API std::istream& operator>> (std::istream& i, Temporal::BBT_Offset& bbt);
 
template<>
struct numeric_limits<Temporal::BBT_Time> {
        static Temporal::BBT_Time lowest() {
                return Temporal::BBT_Time(1, 1, 0);
        }
        static Temporal::BBT_Time min() {
                return Temporal::BBT_Time(1, 1, 0);
        }
 
        static Temporal::BBT_Time max() {
                return Temporal::BBT_Time(std::numeric_limits<int32_t>::max(),
                                          std::numeric_limits<int32_t>::max(),
                                          std::numeric_limits<int32_t>::max());
        }
};
 
template<>
struct numeric_limits<Temporal::BBT_Offset> {
        static Temporal::BBT_Offset lowest() {
                return Temporal::BBT_Time(0, 0, 0);
        }
 
        static Temporal::BBT_Offset min() {
                return Temporal::BBT_Time(0, 0, 0);
        }
 
        static Temporal::BBT_Time max() {
                return Temporal::BBT_Time(std::numeric_limits<int32_t>::max(),
                                          std::numeric_limits<int32_t>::max(),
                                          std::numeric_limits<int32_t>::max());
        }
};
 
 
} /* end of namespace std */
 
namespace PBD {
 
template<>
inline bool to_string (Temporal::BBT_Time val, std::string & str)
{
        std::ostringstream ostr;
        ostr << val;
        str = ostr.str();
        return true;
}
 
template<>
inline std::string to_string (Temporal::BBT_Time val)
{
        std::ostringstream ostr;
        ostr << val;
        return ostr.str();
}
 
template<>
inline bool string_to (std::string const & str, Temporal::BBT_Time & val)
{
        std::istringstream istr (str);
        istr >> val;
        return (bool) istr;
}
 
template<>
inline Temporal::BBT_Time string_to (std::string const & str)
{
        Temporal::BBT_Time tmp;
        string_to (str, tmp);
        return tmp;
}
 
template<>
inline bool to_string (Temporal::BBT_Offset val, std::string & str)
{
        std::ostringstream ostr;
        ostr << val;
        str = ostr.str();
        return true;
}
 
template<>
inline std::string to_string (Temporal::BBT_Offset val)
{
        std::ostringstream ostr;
        ostr << val;
        return ostr.str();
}
 
template<>
inline bool string_to (std::string const & str, Temporal::BBT_Offset & val)
{
        std::istringstream istr (str);
        istr >> val;
        return (bool) istr;
}
 
template<>
inline Temporal::BBT_Offset string_to (std::string const & str)
{
        Temporal::BBT_Offset tmp;
        string_to (str, tmp);
        return tmp;
}
 
} /* end namespace PBD */
 
#endif /* __libtemporal_bbt_time_h__ */