/**
 * Generic pixel-space label geometry helpers shared by the axis,
 * legend, and tooltip overlays.
 *
 * All rectangles are in CSS pixels, origin top-left, Y-axis pointing down.
 */
import type { Context2D } from "../charts/canvas-types";
export interface Rect {
    x: number;
    y: number;
    width: number;
    height: number;
}
export type Rotation = 0 | 45 | 90;
/**
 * Bounding rectangle of a text label anchored at `(cx, cy)`, accounting for
 * rotation. Matches d3fc's approximation of rotated text bounds.
 */
export declare function labelRect(cx: number, cy: number, textWidth: number, textHeight: number, rotation: Rotation): Rect;
export declare function rectsOverlap(a: Rect, b: Rect): boolean;
/**
 * Rotated-label overlap heuristic from d3fc: for steeply-rotated labels
 * the right edge of the previous box must precede the right edge of the
 * next (plus a small gap).
 */
export declare function rotatedLabelsOverlap(a: Rect, b: Rect): boolean;
export declare function rectContained(inner: Rect, outer: Rect): boolean;
/**
 * Truncate `label` with a trailing ellipsis so the rendered width fits
 * within `maxWidth`. Returns "" when even one character would overflow.
 */
export declare function truncateLabel(ctx: Context2D, label: string, maxWidth: number): string;
/**
 * Word-wrap `text` into at most `maxLines` lines, each fitting within
 * `maxWidth`. Breaks at the last whitespace before the fit boundary
 * when possible, falls back to a hard character break otherwise. The
 * final line is ellipsis-truncated via {@link truncateLabel} if it
 * still doesn't fit. Returns `[]` when nothing meaningful fits (only
 * one line of ≤ 2 chars after wrapping).
 */
export declare function wrapLabel(ctx: Context2D, text: string, maxWidth: number, maxLines: number): string[];