import type { SurfaceOptions } from "./types.ts";
import { type Unit } from "./units.ts";
/** Text made safe for a class name or an id: letters, digits, underscores, spaces and hyphens. */
export declare const safeClass: (text: string | undefined) => string;
/** The prefix of the ids inside a drawing: the `id` option, or a hash of the options, so that the same call gives the same drawing. */
export declare const drawingId: (o: SurfaceOptions) => string;
/** True when a drawing with these options lies in portrait. */
export declare function isPortrait(o: Pick<SurfaceOptions, "orientation" | "aspect"> & {
    sport?: SurfaceOptions["sport"];
}): boolean;
/** The unit the options' lengths are in: `units`, or feet when it is missing. A unit that is not one is an error, not feet. */
export declare function lengthUnit(o: Pick<SurfaceOptions, "units">): Unit;
/** The fence the options give, with each distance in feet. */
export declare function feetFence(fence: SurfaceOptions["fence"], unit: Unit): SurfaceOptions["fence"];