/**
 * The {@link CoordSimplex} positions nodes to maximize line straightness.
 * This is adapted from methods used for dot layout.
 *
 * @packageDocumentation
 */
import type { GraphLink } from "../../graph";
import type { Coord } from ".";
/**
 * a strictly callable {@link SimplexWeight}
 */
export type CallableSimplexWeight<NodeDatum = never, LinkDatum = never> = (link: GraphLink<NodeDatum, LinkDatum>) => readonly [number, number, number];
/**
 * an accessor to get how vertical a weight should be.
 *
 * A weight accessor returns three postitive numbers, where higher numbers
 * indicate than edge should be more vertical. The first number corresponds to
 * short edges, the second to medium edges, and the last one to the middle of
 * long edges. These numbers should generally be increasing.
 */
export type SimplexWeight<NodeDatum = never, LinkDatum = never> = readonly [number, number, number] | CallableSimplexWeight<NodeDatum, LinkDatum>;
/** the operators of the simplex operator */
export interface CoordSimplexOps<N = never, L = never> {
    /** the weights for each edge */
    weight: SimplexWeight<N, L>;
}
/** node datum for operators */
export type OpNodeDatum<O extends CoordSimplexOps> = O extends CoordSimplexOps<infer N, never> ? N : never;
/** link datum for operators */
export type OpLinkDatum<O extends CoordSimplexOps> = O extends CoordSimplexOps<never, infer L> ? L : never;
/**
 * a {@link Coord} that places nodes to maximize edge verticality
 *
 * The minimization mirrors that of Gansner, Emden R., et al. "A technique for
 * drawing directed graphs." IEEE Transactions on Software Engineering (1993).
 * This tries to make nodes close together, assigning greater weight for nodes
 * as part of an edge.
 *
 * Create with {@link coordSimplex}.
 */
export interface CoordSimplex<Ops extends CoordSimplexOps> extends Coord<OpNodeDatum<Ops>, OpLinkDatum<Ops>> {
    /**
     * set the weights for how vertical edges should be
     *
     * The higher the weight, the more vertical an edge should be. Weights are
     * are triplets of numbers describing the weight for different parts of edge.
     * The first is between true nodes, the second is for near true nodes, and
     * the last is for the extents of long edges. Generally the number should be
     * increasing, and all must be positive.
     *
     * (default: `[1, 2, 8]`)
     */
    weight<NewWeight extends SimplexWeight>(val: NewWeight): CoordSimplex<{
        /** new weight */
        weight: NewWeight;
    }>;
    /** gets the current weight accessor */
    weight(): Ops["weight"];
    /** @internal flag indicating that this is built in to d3dag and shouldn't error in specific instances */
    readonly d3dagBuiltin: true;
}
/** default simplex operator */
export type DefaultCoordSimplex = CoordSimplex<{
    /** default weights taken from graphvis */
    weight: readonly [1, 2, 8];
}>;
/**
 * create a default {@link CoordSimplex}
 *
 * The simplex coordinate assignment operator tries to minimize edge length,
 * while also trying to make long edges vertical. This uses an optimization
 * that can take a long time, but is usually fast enough on moderately sized
 * graphs.
 *
 * @example
 *
 * ```ts
 * const layout = sugiyama().coord(coordSimplex().weight([2, 2, 4]));
 * ```
 */
export declare function coordSimplex(...args: never[]): DefaultCoordSimplex;