MuseScore/miditools/tempomap.cpp
2013-04-08 17:49:04 +02:00

58 lines
1.7 KiB
C++

//=============================================================================
// MuseScore
// Music Composition & Notation
//
// Copyright (C) 2007-2011 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
//=============================================================================
#include "tempomap.h"
//---------------------------------------------------------
// tempo
//---------------------------------------------------------
double TempoMap::tempo(int tick) const
{
if (empty())
return 2.0;
auto i = lower_bound(tick);
if (i == end()) {
--i;
return i->second;
}
if (i->first == tick)
return i->second;
if (i == begin())
return 2.0;
return i->second;
}
//---------------------------------------------------------
// time2tick
//---------------------------------------------------------
int TempoMap::time2tick(double val, double relTempo, int division) const
{
double time = 0;
int tick = 0;
double tempoDiv = division * relTempo;
double tempo = 2.0;
for (auto e = begin(); e != end(); ++e) {
int delta = e->first - tick;
double time2 = time + double(delta) / (tempoDiv * tempo);
if (val > time2)
break;
tick = e->first;
tempo = e->second;
time = time2;
}
return tick + (val - time) * tempoDiv * tempo;
}