/**
 * Bundled coordinate reference systems, shared by every decoder that has to
 * turn projected coordinates into lon/lat.
 *
 * Extracted from cityjson.ts so the IFC path can reuse it. An IFC file's
 * `IfcMapConversion` states its position in a projected CRS named by
 * `IfcProjectedCRS`, exactly as CityJSON states one in
 * `metadata.referenceSystem`, so both need the same table and the same lazy
 * proj4 import. Duplicating it would have meant a Dutch model georeferencing
 * correctly as CityJSON and 108 m out as IFC.
 *
 * proj4 is imported LAZILY at the point of use, never at module scope: most
 * files need no projection at all, and the ones that do are already paying for
 * a parse.
 */
export interface CrsEntry {
    def: string;
    /** Source stores [northing, easting] / [lat, lon] — swap before handing to proj4. */
    swapXY?: boolean;
    /** Already angular: no reprojection, but horizontal metrics need a local metric frame. */
    geographic?: boolean;
}
/** Compound (horizontal + vertical) codes → the horizontal component that actually projects. */
export declare const COMPOUND_TO_HORIZONTAL: Record<number, number>;
export declare const CRS_DEFS: Record<number, CrsEntry>;
/** The EPSG codes this build can convert without help. */
export declare function bundledCrsCodes(): number[];
/**
 * Projected (or geographic) coordinates in EPSG:`code` -> `[lon, lat]`.
 *
 * Returns null when the code is not bundled, which callers must treat as "I
 * cannot place this" rather than silently substituting something else — a
 * wrong position looks exactly like a right one.
 *
 * `x`/`y` are given easting-first; entries flagged `swapXY` (Japan's plane
 * systems, RD's formal axis order) are swapped here so callers never have to
 * know which convention a CRS uses.
 */
export declare function projectedToLonLat(code: number, x: number, y: number): Promise<[number, number] | null>;
/**
 * Bearing of the projection's GRID north at a point, in degrees clockwise from
 * true north — the grid convergence.
 *
 * Measured rather than derived: unproject the point and a second one a short
 * step further north IN GRID SPACE, then take the true bearing between them.
 * That works for any projection in the table without per-CRS formulae, and it
 * matters because a model aligned to a national grid is NOT aligned to true
 * north. Dutch RD at Rotterdam is off by -0.735 degrees.
 */
export declare function gridConvergence(code: number, x: number, y: number, step?: number): Promise<number | null>;