/**
 * Font metric data for auto-fit column width and row height calculation.
 *
 * ## Architecture
 *
 * This module provides font advance width data at three precision tiers:
 *
 * **Tier 1 (Bitmap-accurate):** Calibri 11pt pixel widths, verified against
 * Excel's actual bitmap metrics (EBDT table). These values match
 * ClosedXML and rust_xlsxwriter measurements exactly.
 *
 * **Tier 2 (FUnit-accurate):** Per-character advance widths in font design units
 * (FUnits) extracted from TTF hmtx tables for Calibri and 8 other common fonts.
 * At runtime, pixel widths are calculated via:
 *   `pixelWidth = ROUND(advanceFU / unitsPerEm * ROUND(fontSize / 72 * 96))`
 * This matches Excel's outline rendering for all sizes except Calibri 11pt
 * (where bitmap metrics differ from outline).
 *
 * **Tier 3 (Factor-based):** For ~230 other fonts, per-category average width
 * factors (lowercase, uppercase, wide) from excelize's experimentally-tuned table.
 *
 * ## Key References
 *
 * - ClosedXML Cell Dimensions wiki: https://github.com/closedxml/closedxml/wiki/Cell-Dimensions
 * - rust_xlsxwriter utility.rs pixel_width()
 * - excelize templates.go supportedFontWidthFactors
 * - ECMA-376 §18.3.1.13 (col element, width attribute)
 */
/** Calibri Regular 11pt per-character pixel widths (code point -> pixels) */
declare const CALIBRI_11PT_PX: Record<number, number>;
/** Font metrics header: unitsPerEm, usWinAscent, usWinDescent, maxDigitAdvance, sTypoAscender, sTypoDescender, sTypoLineGap */
export interface FontMetricsHeader {
    unitsPerEm: number;
    usWinAscent: number;
    usWinDescent: number;
    maxDigitAdvance: number;
    sTypoAscender: number;
    sTypoDescender: number;
    sTypoLineGap: number;
}
/** Run-length encoded advance data: [startCodePoint, count, advanceFU] */
export type AdvanceRun = [start: number, count: number, advance: number];
export interface FontMetrics {
    header: FontMetricsHeader;
    /** Default advance for characters not in the table (typically Latin average) */
    defaultAdvance: number;
    /** Advance width for CJK ideographs (U+4E00..U+9FFF) */
    cjkAdvance: number;
    /** Run-length encoded advance data */
    advances: AdvanceRun[];
}
/**
 * Get FUnit metrics for a font by name, optionally bold variant.
 * Returns undefined if no FUnit data is available (falls back to Tier 3).
 * When bold is true and no bold-specific metrics exist, returns the regular variant.
 */
export declare function getFontMetrics(fontName: string, bold?: boolean): FontMetrics | undefined;
/**
 * Check if a font has a dedicated bold metrics table.
 * When false, the bold multiplier (1.05) should be applied to width calculations.
 */
export declare function hasBoldMetrics(fontName: string): boolean;
/**
 * Get the Calibri Regular metrics (default font).
 */
export declare function getDefaultFontMetrics(): FontMetrics;
/**
 * Get the advance width of a character in FUnits for a given font.
 * Returns the font's defaultAdvance if the character is not in the table.
 *
 * For CJK Unified Ideographs (U+4E00..U+9FFF, U+3400..U+4DBF, U+F900..U+FAFF),
 * returns the font's cjkAdvance.
 */
export declare function getCharAdvance(metrics: FontMetrics, codePoint: number): number;
/**
 * Get the Calibri 11pt bitmap pixel width for a character.
 * Returns undefined if not in the bitmap table.
 */
export declare function getCalibri11PtPixelWidth(codePoint: number): number | undefined;
/**
 * Get Tier 3 font width factors [lowercase, uppercase, wide] for a font.
 * Returns undefined if no factors are available.
 */
export declare function getFontWidthFactors(fontName: string): [number, number, number] | undefined;
/**
 * Check if a code point is an East Asian wide/fullwidth character.
 * This replaces golang.org/x/text/width from excelize.
 */
export declare function isWideCharacter(codePoint: number): boolean;
export { CALIBRI_11PT_PX };