/**
 * Effect runner (spec: "Map Stories / Effect verbs", Phase C) — drives the
 * per-frame channel for the verbs that need a clock (`trace`, `pulse`).
 * `fade` is NOT here: it's pure attribute mechanics (opacity + transition),
 * which keeps it DOM-visible and scrub-capturable.
 *
 * One active effect per (core, layer): starting a new one cancels the old
 * (last-write-wins, the library-wide action rule). prefers-reduced-motion
 * jumps straight to the final frame — same contract as camera animation.
 */
import type { RuntimeCore } from "./runtime-core";
/** Pure easing/oscillation math — unit-testable without a clock. */
/**
 * Named easing curves for effect verbs (`<om-step action="trace" easing="ease-in-out">`).
 * Applied to the effect clock BEFORE the frame callback — one place, every verb.
 */
export declare const EASINGS: Record<string, (t: number) => number>;
export declare function traceProgress(t01: number, t0: number, t1: number): number;
/** Oscillates 1 → low → 1 per cycle (cosine), ending exactly at 1 for whole cycles. */
export declare function pulseOpacity(t01: number, cycles: number, low?: number): number;
export declare function prefersReducedMotion(): boolean;
export interface LayerEffect {
    /** t01 ∈ [0, 1] → the plain-prop patch for this frame. */
    frame(t01: number): Record<string, unknown>;
    /** What to do at the end: hold the final frame's patch, or clear it. */
    end: "hold" | "clear";
    /** Optional clock easing (see EASINGS) — applied before `frame`. */
    easing?: (t: number) => number;
    /** Runs after the end state is applied — phase chaining (trace: draw → reveal → dissolve). */
    onDone?(): void;
}
/**
 * Per-feature trace geometry (spec: "Effect verbs / per-feature trace") —
 * pure: a GeoJSON-ish feature (or bare geometry / flat row) → the outline
 * path with CUMULATIVE-DISTANCE timestamps, so the draw speed is uniform
 * around the perimeter regardless of vertex spacing. Polygon → outer ring;
 * MultiPolygon → EVERY part's outer ring, drawn in sequence longest-first
 * (one currentTime sweep, ring timestamps offset by the running total);
 * LineString → the line itself.
 * Returns null for untraceable geometry (points, missing geometry).
 */
export interface TraceSegment {
    path: [number, number][];
    timestamps: number[];
}
export declare function buildTraceOutline(feature: unknown): {
    segments: TraceSegment[];
    total: number;
} | null;
export declare function cancelLayerEffect(core: RuntimeCore, layerId: string): void;
export declare function cancelAllLayerEffects(core: RuntimeCore): void;
export declare function runLayerEffect(core: RuntimeCore, layerId: string, durationMs: number, effect: LayerEffect): void;