envelopeelement

EnvelopeElement is a modular component used to model the evolution of a parameter over time. It represents a control curve or envelope that maps time to a normalized value, which is then scaled to influence a target parameter such as amplitude, frequency, filter cutoff, or a morphing attribute. EnvelopeElements are commonly employed in audio synthesis, digital signal processing, and animation to provide temporal modulation with precise timing and shaping.

In practice, an EnvelopeElement encapsulates a time-based profile. Typical configurations include attack, decay, sustain, and release phases, but envelopes can also be defined by arbitrary segments or curves. Core properties often include the current value, start and end points, minimum and maximum bounds, and phase timings. Shape options may include linear, exponential, logarithmic, or custom curves, along with a curvature parameter that adjusts the transition steepness. The element may operate with a gate signal or trigger events to start and stop the envelope, and it may support retriggering, looping, or one-shot behavior.

An EnvelopeElement is usually implemented as a small, reusable unit that can be wired into larger modulation graphs. It can be used on a per-note basis in polyphonic contexts or as a shared controller for parameter automation. Interface methods typically include evaluate(time) to obtain the current value, trigger() to start the envelope, release() to begin the release phase, and reset() to return to the initial state. In synthesis, EnvelopeElements are often combined to form more complex envelopes or mapped to multiple targets for coordinated modulation.

Related concepts include ADSR envelopes, envelope generators, and automation or modulation paths in digital audio workstations and animation systems.