import type { VDTBlock, VDTDocument, VDTLine, VDTPage } from './vdt.js';
/**
 * The word spacing of a justified line in the units of
 * `bodyText.minWordSpacing` and `maxWordSpacing` (#704): the ratio the
 * breaker bounds (`justifiedSpaceLimitRatio`) when the line carries one,
 * else `justifiedSpaceRatio`, which is the same number on a line whose
 * spaces all come from the regular face. Undefined for a line that is not
 * justified. Compare this with the limits, not `justifiedSpaceRatio`: a
 * line that holds a bold or an italic space is painted a little over or
 * under the limit it was broken within.
 */
export declare function lineWordSpacing(line: Pick<VDTLine, 'justifiedSpaceRatio' | 'justifiedSpaceLimitRatio'>): number | undefined;
/**
 * How loosely a line is set, as a word-space ratio: its word spacing
 * ({@link lineWordSpacing}), or, for a CJK line spread between its characters
 * (segment `tracking`), `1 + tracking / (⅛ em)` — at the default threshold
 * of 3, a line whose characters are spread by more than ¼ em is loose. The
 * larger of the two when a line has both; undefined when it has neither.
 * `fontSizePx` is the block's text size.
 */
export declare function lineLooseness(line: VDTLine, fontSizePx: number): number | undefined;
/** A justified line whose word spaces stretch past the loose-line threshold,
 *  with the band the highlight covers. */
export interface LooseLine {
    block: VDTBlock;
    line: VDTLine;
    /** The line's word spacing as the limits bound it
     *  ({@link lineWordSpacing}); for a CJK line spread between its
     *  characters, the ratio {@link lineLooseness} gives. */
    ratio: number;
    /** The highlight band, in page pixels: the block's full width across the
     *  line's box. */
    x: number;
    y: number;
    width: number;
    height: number;
}
export interface FindLooseLinesOptions {
    /** A line counts as loose when its ratio exceeds this. Default: 3, the
     *  default `debug.looseLineHighlight.threshold`; pass a config's own with
     *  `resolveDebugConfig(config.debug).looseLineHighlight.threshold`. */
    threshold?: number;
    /** Only the lines of this page. Default: every page. */
    pageIndex?: number;
}
export interface DrawLooseLinesOptions {
    /** See {@link FindLooseLinesOptions.threshold}. */
    threshold?: number;
    /** Any canvas fill style. Default: `#ff000040` (a translucent red), the
     *  default `debug.looseLineHighlight.color`. */
    color?: string;
}
/**
 * The loose lines of a laid-out document, in block and line order: the lines
 * the Sandbox's loose-line highlight and its `looseLine` check mark.
 */
export declare function findLooseLines(doc: VDTDocument, options?: FindLooseLinesOptions): LooseLine[];
/**
 * Paint the loose-line highlight of one page onto a 2D context, in page
 * pixels under the context's current transform — call it right after
 * `renderPage` / `renderPageToCanvas` on the same canvas, which leave the
 * context scaled to the page. Returns the lines it painted.
 */
export declare function drawLooseLines(ctx: CanvasRenderingContext2D | OffscreenCanvasRenderingContext2D, page: VDTPage, doc: VDTDocument, options?: DrawLooseLinesOptions): LooseLine[];
//# sourceMappingURL=looseLines.d.ts.map