public void NewMeasure(double beatSpaceLength)
{
if (_measureBeatSpace != null)
{
_beatCursor = _measureBeatSpace.End;
}
_measureBeatSpace = new LinearInterval
{
Start = _beatCursor,
End = _beatCursor + beatSpaceLength
};
}
public static IEnumerable <SongSegment> CalculateSongSegments(Tempo tempo, double songLength, double offset = 0)
{
var bpmChanges = tempo.Bpm.ToList();
if (!bpmChanges.Any())
{
throw new ArgumentException("tempo must at least contain one bpm entry", nameof(tempo));
}
if (bpmChanges.First().Time > 0)
{
bpmChanges[0] = new BpmChange {
Time = 0, Bpm = bpmChanges.First().Bpm
};
}
var segmentBoundaries =
new Queue <ITimeIndexed>(
bpmChanges.Cast <ITimeIndexed>()
.Concat(tempo.Interruptions.Cast <ITimeIndexed>())
.OrderBy(x => x.Time));
var timeCursor = offset;
var beatCursor = 0.0;
var bpm = 0.0;
var segments = new List <SongSegment>();
Action <double> commitSegment = end =>
{
var songTime = new LinearInterval
{
Start = timeCursor,
End = end
};
var beatSpace = new LinearInterval
{
Start = beatCursor,
End = beatCursor + songTime.Length * bpm / 60
};
segments.Add(new SongSegment
{
Bpm = bpm,
SongTime = songTime,
BeatSpace = beatSpace
});
};
while (segmentBoundaries.Count > 0)
{
var current = segmentBoundaries.Dequeue();
if (current.Time > timeCursor)
{
commitSegment(current.Time);
timeCursor = current.Time;
beatCursor += segments.Last().BeatSpace.Length;
}
var bpmChange = current as BpmChange;
if (bpmChange != null)
{
bpm = bpmChange.Bpm;
}
var interruption = current as Interruption;
if (interruption != null)
{
timeCursor += interruption.Duration;
}
}
if (timeCursor < songLength)
{
commitSegment(songLength);
}
return(segments);
}
