1. Epic GamesDeveloper
  3. FEnvelope

FEnvelope

Envelope class generates ADSR style envelope.

API > API/Runtime > API/Runtime/SignalProcessing > API/Runtime/SignalProcessing/DSP

References

   
Module SignalProcessing
Header /Engine/Source/Runtime/SignalProcessing/Public/DSP/Envelope.h
Include #include "DSP/Envelope.h"

Syntax

class FEnvelope

Remarks

Envelope class generates ADSR style envelope.

Variables

  Type Name Description
Protected variable FEnvData AttackData  
Protected variable float AttackTimeMSec  
Protected variable uint8: 1 bBiasInvert Bias output inversions.
Protected variable uint8: 1 bChanged Whether or not this envelope has changed and needs to have values recomputed.
Protected variable uint8: 1 bCurrentCycleIsADOnly Tracks if the current envelope was started with sustain at 0.0 (avoids bug where sustain being turned up during decay phase makes note hang)
Protected variable float BiasDepth  
Protected variable FPatchSource BiasedEnvSource  
Protected variable uint8: 1 bInvert Inverts the output.
Protected variable uint8: 1 bIsLegatoMode Whether or not the envelope is reset back to attack when started.
Protected variable uint8: 1 bIsRetriggerMode Whether or not the envelope value is set to zero when finished.
Protected variable uint8: 1 bIsSimulatingAnalog Whether or not we want to simulate analog behavior.
Protected variable float CurrentEnvelopeBiasValue  
Protected variable float CurrentEnvelopeValue  
Protected variable EEnvelopeState CurrentState  
Protected variable FEnvData DecayData  
Protected variable float DecayTimeMsec  
Protected variable float Depth  
Protected variable FPatchSource EnvSource  
Protected variable FModulationMatrix * ModMatrix Mod matrix.
Protected variable float OutputGain  
Protected variable FEnvData ReleaseData  
Protected variable float ReleaseTimeMsec  
Protected variable float SampleRate  
Protected variable float ShutdownDelta  
Protected variable float ShutdownTimeMsec  
Protected variable float SustainGain  
Protected variable int32 VoiceId The current envelope value, used to compute exponential envelope curves.

Constructors

  Type Name Description
Public function    

Destructors

  Type Name Description
Public function Virtual    

Functions

  Type Name Description
Public function Virtual float

Generate ( float* BiasedOutput
)

 Generate the next output value of the envelope.
Public function Const const FPatchSource  
Public function Const const FPatchSource Get the envelope's patch nodes.
Public function Virtual Const EEnvelopeState  
Public function void

Init ( const float InSampleRate,
const int32 InVoiceId,
FModulationMatrix* InModMatrix,
const bool bInSimulateAnalog
)

 Initialize the envelope with the given sample rate.
Public function Virtual Const bool

IsDone ()

 Queries if the envelope has finished.
Public function Const bool  
Public function Virtual void

Kill ()

 Kills the envelope (will cause discontinuity)
Public function Virtual void

Reset ()

 Resets the envelope.
Public function Virtual void

SetAttackTime ( const float InAttackTimeMsec
)

 Sets the envelope attack time in msec.
Public function Virtual void

SetBiasDepth ( const float InDepth
)

 Sets the depth of the bias output.
Public function Virtual void

SetBiasInvert ( const bool bInBiasInvert
)

 Inverts the value of the biased envelope output.
Public function Virtual void

SetDecayTime ( const float InDecayTimeMsec
)

 Sets the envelope decay time in msec.
Public function Virtual void

SetDepth ( const float InDepth
)

 Sets the envelope depth.
Public function Virtual void

SetInvert ( const bool bInInvert
)

 Inverts the value of envelope output.
Public function void

SetLegato ( const bool bInLegatoMode
)

 Sets whether the envelope is in legato mode. Legato mode doesn't restart the envelope if it's already playing.
Public function Virtual void

SetReleaseTime ( const float InReleaseTimeMsec
)

 Sets the envelope release time in msec.
Public function void

SetRetrigger ( const bool bInRetrigger
)

 Sets whether or not the envelope is zero'd when reset.
Public function void

SetSimulateAnalog ( const bool bInSimulatingAnalog
)

 Sets the envelope mode.
Public function Virtual void

SetSustainGain ( const float InSustainGain
)

 Sets the envelope sustain gain in linear gain values.
Public function Virtual void Puts envelope into shutdown mode, which is a much faster cutoff than release, but avoids pops.
Public function Virtual void

Start ()

 Start the envelope, puts envelope in attack state.
Public function Virtual void  
Public function Virtual void

StartLegato ( const float InNewDepth
)

 For truly legato envelope logic, we need to know the new sustain gain (if its being changed).
Public function Virtual void

Stop ()

 Stop the envelope, puts in the release state. Can optionally force to off state.
Public function Virtual void

Update ()

 Update the state of the envelope.

Classes

  Type Name Description
Protected struct FEnvData    

Enums

  Type Name Description
Public enum EEnvelopeState States for the envelope state machine.  

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page