/* There are two constructors, one of which is a copy constructor. */
public BeatTracker(double interval, BeatEvent firstEvent, double originalScore)
{
Interval = interval;
NextPrediction = firstEvent.Time + interval;
ProcessedItems = new List <BeatEvent>();
ProcessedItems.Add(firstEvent);
/* NOTE: For now we use sum of velocities as the rating.
* This could also use drum-specific information. */
Rating = firstEvent.Notes.Sum(n => n.Velocity);
OriginalScore = originalScore;
}
/* Create a rhythm from a tracker and list of events, by quantizing the events
* according to the beat tracker given to the function. */
public static RhythmStructure CreateRhythm(BeatTracker tracker, List <BeatEvent> events)
{
const byte numDivisions = 4;
int eventIndex = 0;
RhythmStructure rhythm = new RhythmStructure(tracker.Interval);
/* Iterate over all the beats and semiquavers, and set the semiquaver interval. */
for (int i = 0; i < tracker.ProcessedItems.Count; i++)
{
BeatEvent baseEvent = tracker.ProcessedItems[i];
double interval;
if (i != tracker.ProcessedItems.Count - 1)
{
BeatEvent nextEvent = tracker.ProcessedItems[i + 1];
interval = (nextEvent.Time - baseEvent.Time) / 4;
}
else
{
interval = (tracker.NextPrediction - baseEvent.Time) / 4;
}
for (int j = 0; j < numDivisions; j++)
{
HashSet <Drum> drums = new HashSet <Drum>();
/* Determine the time at which one semiquaver event occurs and then quantizes each note event to the semiquaver. */
double baseTime = baseEvent.Time + (j * interval);
if (eventIndex < events.Count && baseTime - (interval / 2) < events[eventIndex].Time && baseTime + (interval / 2) > events[eventIndex].Time)
{
foreach (NoteEvent noteEvent in events[eventIndex].Notes)
{
if (indexToDrum.Keys.Contains(noteEvent.Channel))
{
Drum drum = indexToDrum[noteEvent.Channel];
drums.Add(drum);
}
}
eventIndex++;
}
rhythm.AddDrums(drums);
}
}
return(rhythm);
}
public EventInterval(BeatEvent event1, BeatEvent event2)
{
Event1 = event1;
Event2 = event2;
Length = Math.Abs(event1.Time - event2.Time);
}