public void Start(RegionPair region, int channel, int key, int velocity)
{
this.exclusiveClass = region.ExclusiveClass;
this.channel = channel;
this.key = key;
this.velocity = velocity;
if (velocity > 0)
{
// According to the Polyphone's implementation, the initial attenuation should be reduced to 40%.
// I'm not sure why, but this indeed improves the loudness variability.
var sampleAttenuation = 0.4F * region.InitialAttenuation;
var filterAttenuation = 0.5F * region.InitialFilterQ;
var decibels = 2 * SoundFontMath.LinearToDecibels(velocity / 127F) - sampleAttenuation - filterAttenuation;
noteGain = SoundFontMath.DecibelsToLinear(decibels);
}
else
{
noteGain = 0F;
}
cutoff = region.InitialFilterCutoffFrequency;
resonance = SoundFontMath.DecibelsToLinear(region.InitialFilterQ);
vibLfoToPitch = 0.01F * region.VibratoLfoToPitch;
modLfoToPitch = 0.01F * region.ModulationLfoToPitch;
modEnvToPitch = 0.01F * region.ModulationEnvelopeToPitch;
modLfoToCutoff = region.ModulationLfoToFilterCutoffFrequency;
modEnvToCutoff = region.ModulationEnvelopeToFilterCutoffFrequency;
dynamicCutoff = modLfoToCutoff != 0 || modEnvToCutoff != 0;
modLfoToVolume = region.ModulationLfoToVolume;
dynamicVolume = modLfoToVolume > 0.05F;
instrumentPan = SoundFontMath.Clamp(region.Pan, -50F, 50F);
instrumentReverb = 0.01F * region.ReverbEffectsSend;
instrumentChorus = 0.01F * region.ChorusEffectsSend;
volEnv.Start(region, key, velocity);
modEnv.Start(region, key, velocity);
vibLfo.StartVibrato(region, key, velocity);
modLfo.StartModulation(region, key, velocity);
oscillator.Start(synthesizer.SoundFont.WaveDataArray, region);
filter.ClearBuffer();
filter.SetLowPassFilter(cutoff, resonance);
smoothedCutoff = cutoff;
voiceState = VoiceState.Playing;
voiceLength = 0;
}
public static void Start(this ModulationEnvelope envelope, RegionPair region, int key, int velocity)
{
// According to the implementation of TinySoundFont, the attack time should be adjusted by the velocity.
var delay = region.DelayModulationEnvelope;
var attack = region.AttackModulationEnvelope * ((145 - velocity) / 144F);
var hold = region.HoldModulationEnvelope * SoundFontMath.KeyNumberToMultiplyingFactor(region.KeyNumberToModulationEnvelopeHold, key);
var decay = region.DecayModulationEnvelope * SoundFontMath.KeyNumberToMultiplyingFactor(region.KeyNumberToModulationEnvelopeDecay, key);
var sustain = 1F - region.SustainModulationEnvelope / 100F;
var release = region.ReleaseModulationEnvelope;
envelope.Start(delay, attack, hold, decay, sustain, release);
}