MuseScore/libmscore/sig.h
2019-04-17 22:17:47 +08:00

158 lines
6.8 KiB
C++

//=============================================================================
// MuseScore
// Music Composition & Notation
//
// Copyright (C) 2002-2009 Werner Schweer
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2
// as published by the Free Software Foundation and appearing in
// the file LICENCE.GPL
//=============================================================================
#ifndef __AL_SIG_H__
#define __AL_SIG_H__
#include "fraction.h"
namespace Ms {
class XmlWriter;
class XmlReader;
int ticks_beat(int n);
//-------------------------------------------------------------------
// BeatType
//-------------------------------------------------------------------
enum class BeatType : char {
DOWNBEAT, // 1st beat of measure (rtick == 0)
COMPOUND_STRESSED, // e.g. eighth-note number 7 in 12/8
SIMPLE_STRESSED, // e.g. beat 3 in 4/4
COMPOUND_UNSTRESSED, // e.g. eighth-note numbers 4 or 10 in 12/8
SIMPLE_UNSTRESSED, // "offbeat" e.g. beat 2 and 4 in 4/4 (i.e. the denominator unit)
COMPOUND_SUBBEAT, // e.g. any other eighth-note in 12/8 (i.e. the denominator unit)
SUBBEAT // does not fall on a beat
};
//-------------------------------------------------------------------
// Time Signature Fraction (n/d - numerator/denominator)
//-------------------------------------------------------------------
class TimeSigFrac : public Fraction {
public:
using Fraction::Fraction;
constexpr TimeSigFrac(int n = 0, int d = 1) : Fraction(n, d) {}
TimeSigFrac(const Fraction& f) : TimeSigFrac(f.numerator(), f.denominator()) {}
TimeSigFrac(const TimeSigFrac& f) : TimeSigFrac(f.numerator(), f.denominator()) {}
// isCompound? Note: 3/8, 3/16, ... are NOT considered compound.
bool isCompound() const { return numerator() > 3 /*&& denominator() >= 8*/ && numerator() % 3 == 0; }
// isBeatedCompound? Note: Conductors will beat the simple unit at slow tempos (<60 compound units per minute)
// However, the meter is still considered to be compound (at least for our purposes).
bool isBeatedCompound(qreal tempo) const { return tempo2beatsPerMinute(tempo) >= 60.0; }
int dUnitTicks() const;
int ticksPerMeasure() const { return numerator() * dUnitTicks(); }
int dUnitsPerBeat() const { return isCompound() ? 3 : 1; }
int beatTicks() const { return dUnitTicks() * dUnitsPerBeat(); }
int beatsPerMeasure() const { return numerator() / dUnitsPerBeat(); }
int subbeatTicks(int level) const;
int maxSubbeatLevel() const;
bool isTriple() const { return beatsPerMeasure() % 3 == 0; }
bool isDuple() const { Q_ASSERT(!isTriple()); return beatsPerMeasure() % 2 == 0; } // note: always test isTriple() first
// MuseScore stores tempos in quarter-notes-per-second, so conversions to conventional beats-per-minute format are provided here:
qreal tempo2beatsPerMinute(qreal tempo) const { return tempo * denominator() * 15.0 / dUnitsPerBeat(); }
qreal beatsPerMinute2tempo(qreal bpm) const { return bpm * dUnitsPerBeat() / (15.0 * denominator()); }
BeatType rtick2beatType(int rtick) const;
int rtick2subbeatLevel(int rtick) const; // returns negative value if not on a well-defined subbeat
BeatType strongestBeatInRange(int rtick1, int rtick2, int* dUnitsCrossed = 0, int* subbeatTick = 0, bool saveLast = false) const; // range is exclusive
int strongestSubbeatLevelInRange(int rtick1, int rtick2, int* subbeatTick = 0) const; // range is exclusive
int ticksPastDUnit(int rtick) const { return rtick % dUnitTicks(); } // returns 0 if rtick is exactly on a dUnit
int ticksToNextDUnit(int rtick) const { return dUnitTicks() - ticksPastDUnit(rtick); } // returns dUnitTicks() if rtick is on a dUnit
int ticksPastBeat(int rtick) const { return rtick % beatTicks(); } // returns 0 if rtick is exactly on a beat
int ticksToNextBeat(int rtick) const { return beatTicks() - ticksPastBeat(rtick); } // returns beatTicks() if rtick is on a beat
int ticksPastSubbeat(int rtick, int level) const { return rtick % subbeatTicks(level); }
int ticksToNextSubbeat(int rtick, int level) const { return subbeatTicks(level) - ticksPastSubbeat(rtick, level); }
};
//-------------------------------------------------------------------
// Time Signature Event
// Incomplete measures as for example pickup measures have
// a nominal duration different from actual duration.
//-------------------------------------------------------------------
class SigEvent {
TimeSigFrac _timesig;
TimeSigFrac _nominal;
int _bar; ///< precomputed value
public:
int read(XmlReader&, int fileDivision);
void write(XmlWriter&, int) const;
constexpr SigEvent() : _bar(0) {} ///< default SigEvent is invalid
SigEvent(const Fraction& s, int bar = 0)
: _timesig(s), _nominal(s), _bar(bar) {}
SigEvent(const Fraction& s, const Fraction& ss, int bar = 0)
: _timesig(s), _nominal(ss), _bar(bar) {}
SigEvent(const SigEvent& e);
bool operator==(const SigEvent& e) const;
bool valid() const { return _timesig.isValid(); }
QString print() const { return _timesig.print(); }
TimeSigFrac timesig() const { return _timesig; }
TimeSigFrac nominal() const { return _nominal; }
void setNominal(const Fraction& f) { _nominal = f; }
int bar() const { return _bar; }
void setBar(int val) { _bar = val; }
};
//---------------------------------------------------------
// SigList
//---------------------------------------------------------
class TimeSigMap : public std::map<int, SigEvent > {
void normalize();
public:
TimeSigMap() {}
void add(int tick, const Fraction&);
void add(int tick, const SigEvent& ev);
void del(int tick);
void clearRange(int tick1, int tick2);
void read(XmlReader&, int fileDiv);
void write(XmlWriter&) const;
void dump() const;
const SigEvent& timesig(int tick) const;
const SigEvent& timesig(const Fraction& f) const { return timesig(f.ticks()); }
void tickValues(int t, int* bar, int* beat, int* tick) const;
int bar2tick(int bar, int beat) const;
QString pos(int t) const;
unsigned raster(unsigned tick, int raster) const;
unsigned raster1(unsigned tick, int raster) const; // round down
unsigned raster2(unsigned tick, int raster) const; // round up
int rasterStep(unsigned tick, int raster) const;
};
} // namespace Ms
#endif