import type { SynthPatch } from "./synth.js";
export type AudioBusId = string;
export type FalloffCurve = "linear" | "inverse" | "none";
export interface AudioFalloffConfig {
    /** Distance (world units) at/under which gain is 1. Default 1. */
    minDistance?: number;
    /** Distance at/beyond which gain is 0. Default 24. */
    maxDistance?: number;
    /** "linear" ramps 1→0 between min/max; "inverse" is an inverse-square-style rolloff clamped to the same range; "none" is always 1 (no distance attenuation). Default "linear". */
    curve?: FalloffCurve;
}
export interface AudioBusDef {
    id: AudioBusId;
    /** Bus volume multiplier, 0..1+. Default 1. */
    gain?: number;
}
export interface SoundDef {
    id: string;
    /** Sample source — a URL/data URI the shell's Web Audio glue fetches and decodes. Provide exactly one of `url` or `synth`. */
    url?: string;
    /** Procedural source — a pure synth patch the shell realises on Web Audio, no file fetch. Provide exactly one of `url` or `synth`. */
    synth?: SynthPatch;
    bus: AudioBusId;
    /** Base gain before bus/falloff multipliers. Default 1. */
    gain?: number;
    loop?: boolean;
    /** Maximum simultaneous reservations for this sound, including pending loads. Default the engine's total voice limit. */
    maxVoices?: number;
    /** Playback priority; higher priorities survive voice-budget pressure. Default 0. */
    priority?: number;
    /** Positional emitters attenuate by distance from the listener; non-positional sounds (UI, music) play at flat gain. Default true. */
    positional?: boolean;
    falloff?: AudioFalloffConfig;
    /** Doppler strength for retained loops: 1 is physical, 0 or absent is off. Emitter velocity comes from `setLoop({ velocity })`, listener velocity from the camera. */
    doppler?: number;
    /** Web Audio spatial panning configuration. When present, the shell uses a PannerNode. */
    spatial?: {
        panning: "hrtf" | "equalpower";
        refDistance?: number;
        maxDistance?: number;
        rolloff?: number;
        coneInner?: number;
        coneOuter?: number;
        coneOuterGain?: number;
    };
}
export declare function computeFalloffGain(distance: number, config?: AudioFalloffConfig): number;
export declare function resolveEmitterGain(distance: number, sound: Pick<SoundDef, "gain" | "positional" | "falloff">, busGain: number): number;
export declare function distance3(a: {
    x: number;
    y: number;
    z: number;
}, b: {
    x: number;
    y: number;
    z: number;
}): number;