truce-params

Parameter system for the truce audio plugin framework.

Overview

Provides the types and utilities for declaring, smoothing, and formatting plugin parameters. Parameters are the primary interface between a plugin and its host -- they drive automation, presets, and UI controls. Use this crate's types inside your Params struct, then derive with #[derive(Params)].

Key types

• FloatParam -- continuous floating-point parameter (with smoother)
• IntParam -- discrete integer parameter. Pick this over FloatParam whenever range = "discrete(...)" describes the parameter - the type expresses intent and skips the unused smoother state.
• BoolParam -- on/off toggle parameter
• EnumParam -- parameter backed by a Rust enum (via #[derive(ParamEnum)])
• ParamRange -- defines value ranges and mapping curves (linear, logarithmic, discrete)
• Smoother / SmoothingStyle -- per-sample parameter smoothing to avoid zipper noise
• ParamInfo -- metadata (name, unit label, flags) for host communication
• Float / Sample -- sealed traits over f32 / f64 that carry the cross-precision math methods (to_f32, to_f64, from_f32, from_f64, plus exp, log10, powf). Sample is Float + Default + Send + Sync + 'static - the audio buffer element bound.
• FloatParamReadF32 / FloatParamReadF64 -- precision-routed read traits. The prelude brings one of them into scope as _; param.read() then returns f32 or f64 directly without per-call-site annotation.

Example

#[derive(Params)]
struct MyParams {
    #[param(name = "Gain", range = "linear(-60.0, 0.0)", unit = "dB",
            smooth = "exp(5)")]
    gain: FloatParam,

    #[param(name = "Semitones", range = "discrete(-12, 12)", unit = "st")]
    semitones: IntParam,  // discrete-integer params use IntParam, not FloatParam

    #[param(name = "Mode")]
    mode: EnumParam<FilterMode>,
}

Part of truce.