/**
 * Arc series: connections between places.
 *
 * The mark for airline routes, submarine cables, trade, migration and remittance
 * flows. Two things make this series either credible or embarrassing, and both are
 * handled here rather than left to the caller:
 *
 * 1. **Geodesics, on by default.** The shortest path between two places is a great
 *   circle, not a straight line on a projected map. A Tokyo to New York route
 *   really does arc over the Arctic, and drawing the straight line misstates both
 *   the path and its length.
 * 2. **Antimeridian crossings.** A Tokyo to Los Angeles arc must leave the right
 *   edge of the map and re-enter at the left, not streak backwards across the
 *   whole world. Emitting the arc as a lon/lat LineString and letting d3-geo cut
 *   it is what makes that correct for free, in every projection.
 *
 * Endpoints may be `[lon, lat]` pairs or geometry keys, so "route network between
 * these airports" and "trade between these countries" are both one line of config.
 *
 * @module series/Arc
 */
import { Scale } from '../scales/Scale';
import { SizeScale } from '../scales/SizeScale';
import { Viewport } from '../geo/Viewport';
import type { ArcSeriesOptions, LonLat, MarkItem, NormalizedGeo, WorldPoint } from '../types';
import type { PathSpec } from '../renderers/SvgRenderer';
export interface ArcItem extends MarkItem {
    from: LonLat;
    to: LonLat;
    /** Path data in world space, rebuilt whenever the projection changes. */
    d: string;
    width: number;
    fromLabel?: string;
    toLabel?: string;
}
export declare class ArcSeries {
    static readonly type: "arc";
    static readonly kind: "paths";
    readonly type: "arc";
    readonly kind: "paths";
    readonly config: ArcSeriesOptions;
    readonly index: number;
    readonly id: string;
    readonly warnings: string[];
    readonly items: ArcItem[];
    readonly widthScale: SizeScale;
    readonly colorScale: Scale | null;
    /**
     * Class indices switched off from the legend.
     *
     * A muted class hides its routes rather than greying them, which is the
     * opposite of what a choropleth does with the same click, and for a reason: a
     * choropleth cannot remove a country, so it can only drain the colour out of
     * it, while a route is nothing but the datum. Fourteen grey lines left behind
     * would be the clutter the reader clicked to get rid of.
     */
    readonly mutedClasses: Set<number>;
    constructor({ config, geo, index, viewport, }: {
        config: ArcSeriesOptions;
        geo: NormalizedGeo;
        index: number;
        viewport: Viewport;
    });
    /**
     * Rebuild path data. Called on construction and after any projection change,
     * because arc geometry is projection-dependent while its endpoints are not.
     */
    reproject(viewport: Viewport): void;
    itemAt(index: number): ArcItem | undefined;
    colorFor(item: ArcItem): string;
    /** Whether the legend has switched off the class this route falls in. */
    isMuted(item: ArcItem): boolean;
    paths(): PathSpec[];
    /** Endpoint dots, drawn as screen-space symbols so they keep a constant size. */
    endpoints(viewport: Viewport): {
        key: string;
        item: number;
        world: WorldPoint;
        radius: number;
        fill: string;
    }[];
    legendTitle(): string | undefined;
    /**
     * Switch a legend class off, or back on. Returns the new muted state.
     *
     * A series with no `colorScale` has no classes and no swatches, so there is
     * nothing to toggle and the legend does not offer it.
     */
    toggleClass(classIndex: number): boolean;
    legendItems(): never[];
    describe(item: ArcItem): string;
    advise(): string[];
    /** Resolve an endpoint that may be coordinates or a geometry key. */
    private resolveEndpoint;
}
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