/**
 * `anchor="surface"` (universal layer attribute, the classify/filter
 * pattern): installs a `getPosition` that anchors each row INSIDE its own
 * polygon — on-map annotations (TextLayer labels on shapes) without a
 * card/popup and without authoring per-row coordinates. Resolved where the
 * rows are in hand (parse-manifest / descriptorToIR); an authored
 * `get-position` wins. Placement: centroid of the largest ring, verified
 * inside; a concave polygon whose centroid falls outside gets the midpoint
 * of the widest interior run of a horizontal line through the centroid
 * latitude (polylabel-lite — cheap and always inside).
 */
import type { LayerData } from "./ir";
import type { Shape } from "./expr";
/** A point guaranteed inside the largest ring of the geometry (see module doc). */
export declare function pointOnSurface(coords: unknown): [number, number] | null;
/** Installs the surface-anchored getPosition (no-ops: no anchor, authored position, no rows yet). */
export declare function applySurfaceAnchor(props: Record<string, unknown>, anchor: string | undefined, data: LayerData, shape: Shape, warnLabel: string): void;