/**
 * Feature labels, with collision avoidance.
 *
 * Label placement is where chart-library maps visibly lose to Mapbox and ArcGIS
 * today, so even the phase-1 version does the
 * things that matter:
 *
 * - **Priority ordering.** Larger and higher-valued features win, so dropping
 *   labels degrades gracefully instead of arbitrarily.
 * - **Axis-aligned collision** against already-placed labels.
 * - **Area gating.** A label wider than its feature is noise.
 * - **Halo by default** via `paint-order`, so text stays readable on any fill.
 *
 * Labels are drawn in the screen-space overlay, not the world group: text must
 * not scale with the camera. They are re-laid-out on camera change, which is
 * cheap because the candidate set is small and pre-sorted.
 *
 * @module components/Labels
 */
import type { SvgRenderer } from '../renderers/SvgRenderer';
import type { Viewport } from '../geo/Viewport';
import type { Anchor, DataLabelOptions, NormalizedFeature, WorldPoint } from '../types';
export interface LabelCandidate {
    text: string;
    /** Anchor in world space. */
    world: WorldPoint;
    /** Higher wins when labels collide. */
    priority: number;
    /** Approximate world-space area, in square pixels. */
    featureArea: number;
    color?: string;
    key?: string;
}
export declare class Labels {
    readonly renderer: SvgRenderer;
    readonly viewport: Viewport;
    /** Re-pointed at the live config on every draw; see `_syncComponentOptions`. */
    options: DataLabelOptions;
    candidates: LabelCandidate[];
    group: SVGGElement | null;
    placedCount: number;
    droppedCount: number;
    constructor({ renderer, viewport, options, }: {
        renderer: SvgRenderer;
        viewport: Viewport;
        options: DataLabelOptions;
    });
    setCandidates(candidates: LabelCandidate[]): void;
    /**
     * Lay out and draw. Called after every render and camera change.
     *
     * @param reserved Screen-space boxes already occupied, currently the
     *   annotation chips. A generated label yields to an annotation rather than
     *   the other way round: the annotation was placed deliberately and the label
     *   was produced by a rule, so the rule is the one that should give way.
     */
    layout(reserved?: readonly Box[]): void;
    destroy(): void;
}
/** An axis-aligned screen-space box, the unit of label collision. */
export interface Box {
    x0: number;
    y0: number;
    x1: number;
    y1: number;
}
/**
 * Label anchor for a feature, in world space.
 *
 * Uses the projected path centroid, then falls back to the bounding-box centre.
 * A proper pole-of-inaccessibility anchor (`polylabel`) is a phase-2 item: it
 * matters for concave shapes such as Florida or Chile where the centroid lands
 * offshore, and it is not worth the dependency until the label engine is doing
 * leader lines too.
 *
 */
export declare function labelAnchor(viewport: Viewport, feature: NormalizedFeature): Anchor | null;
//# sourceMappingURL=Labels.d.ts.map