Envelope Generator Plugin (Alpha Test, starting with the first Version ever (Dayly 2026-08-18))

I am making an Envelope Generator Plugin
mainly for my own Use but i believe others would also use it in a Game.

Envelope Generators are traditionally used in electronic Music to play a Note by animating the Loudness of a continuous Sound.
They typically have 4 Phases, together known as ADSR:

  1. Attack: Starts in the same Moment as the Note.
    It ramps up the Volume of the Note to its Max.
  2. Decay: The Note gets quieter but not mute.
  3. Sustain: For as long as the Note is held, it stays at the same Volume.
  4. Release: When the Note ends, it doesn’t silence abruptly.
    It mutes smoothly.

More Info: Envelope (music) — English Wikipedia

The Purpose of making an Envelope Generator in Godot is that
it can animate much more than just Sound, for Example the Opacity of a Sprite.

Typical Envelopes only use linear Interpolation between the Start and End of each Phase
but my Implementation uses Curves, so i can change the Shape of each Phase in a Way that is more expressive but still easy to use.

This is also why i removed the Decay Phase from my Implementation:
Because the Attack Curve can include both Attack and Decay.