public PercussionNoteSegment(
int track,
MidiEventWithTime <OnNoteVoiceMidiEvent> onNoteEvent,
MidiEventWithTime <OffNoteVoiceMidiEvent> offNoteEvent,
int startSample,
int durationSamples,
GeneralMidiPercussion instrument)
: base(track, onNoteEvent, offNoteEvent, startSample, durationSamples)
{
PercussionInstrument = instrument;
PercussionType = PercussionHelper.GetPercussionType(instrument);
}
/// <summary>
/// Gets the duration of a percussion note based on its generalized type. Used by the default INoteSegmentProvider implementation.
/// </summary>
/// <param name="percussionType"></param>
/// <returns></returns>
public static int GetPercussionDurationSamples(PercussionType percussionType)
{
// 440 ms (when samping at 44100 hz). This is the default for Kicker in LMMS
int percussionSampleCount = 19404;
// Bass drum has a shorter sample count to be "punchier"
if (percussionType == PercussionType.Bass)
{
return((int)(percussionSampleCount * 0.5));
}
return(percussionSampleCount);
}
private float GetPercussionMultiplier(PercussionType percussionType)
{
if (PercussionLevels is null || PercussionLevels.Count == 0)
{
return(DefaultMultiplier);
}
if (PercussionLevels.TryGetValue(percussionType, out float multiplier))
{
return(multiplier);
}
return(DefaultMultiplier); // Default to a "non-modified" multiplier
}
private AdsrParameters GetPercussionAdsrParameters(PercussionType percussionType)
{
switch (percussionType)
{
case PercussionType.Bass:
// Same as default but with a AttackAmplitude of 3
return(new AdsrParameters(0.05, 0.1, 1, 0.075, 3));
case PercussionType.Snare:
return(AdsrParameters.Default);
case PercussionType.Crash:
return(AdsrParameters.Long);
case PercussionType.Ride:
default:
return(AdsrParameters.Short);
}
}
// todo Abundant Music WebAudioPlayer has synthesis settings. How did it do the percussion?
private DiscreteSignal GetPercussionSignal(PercussionType percussionType, int sampleCount)
{
switch (percussionType)
{
// Bass drums
case PercussionType.Bass:
var bass = SignalHelper.GetChirp(90, 120, sampleCount);
var bass2 = SignalHelper.GetChirp(180, 240, sampleCount);
var bass3 = SignalHelper.GetChirp(270, 360, sampleCount);
// The chirp builder goes in the "up" direction, so we need to reverse it to go "down"
bass = new DiscreteSignal(Constants.SAMPLE_RATE, bass.Samples.Reverse());
bass2 = new DiscreteSignal(Constants.SAMPLE_RATE, bass2.Samples.Reverse());
bass3 = new DiscreteSignal(Constants.SAMPLE_RATE, bass3.Samples.Reverse());
// Combine the two bass signals so that the bass has more "presence"
bass = bass.Superimpose(bass2).Superimpose(bass3);
return(bass);
// Snare drums
case PercussionType.Snare:
var snare = SignalHelper.GetKarplusStrongDrum(0.5, 30, 1, 1, sampleCount);
return(snare);
// Crash drums
case PercussionType.Crash:
var crash = SignalHelper.GetKarplusStrongDrum(0.5, 11, 1, 1, sampleCount);
return(crash);
// Ride drums
case PercussionType.Ride:
// Defaulting to a ride drum probably isn't good, but it will sound in lots of situations.
default:
var ride = SignalHelper.GetKarplusStrongDrum(0.5, 60, 0.1, 1, sampleCount);
return(ride);
}
}
