import { PDFResource } from '../document/pdf-resource.ts';
/**
 * Options for text shaping.
 */
export type ShapeOptions = {
    /**
     * The OpenType script tag (e.g., 'latn' for Latin, 'arab' for Arabic).
     * If not specified, or if the specified script is not found in the font,
     * the 'DFLT' script will be used if available.
     *
     * See the OpenType specification for a list of script tags:
     * https://learn.microsoft.com/en-us/typography/opentype/spec/scripttags
     */
    scriptTag?: string;
    /**
     * The OpenType language system tag (e.g., 'ENG' for English, 'DEU' for German).
     * If not specified, or if the specified language is not found in the font,
     * the default language for the script will be used.
     *
     * See the OpenType specification for a list of language system tags:
     * https://learn.microsoft.com/en-us/typography/opentype/spec/languagetags
     */
    langSysTag?: string;
    /**
     * Whether to enable the default font features (ligatures and kerning).
     * Defaults to `true`.
     * To disable all default features, set this to `false`.
     */
    defaultFeatures?: boolean;
    /**
     * Font features to apply beyond the defaults.
     * To enable additional features, set them to `true`.
     * To disable specific default features, set them to `false`.
     *
     * See the OpenType specification for a list of feature tags:
     * https://learn.microsoft.com/en-us/typography/opentype/spec/featuretags
     */
    features?: Record<string, boolean>;
};
/**
 * Represents a single glyph in a shaped glyph run, including
 * positioning information for text rendering.
 */
export type ShapedGlyph = {
    /**
     * The glyph ID in the font.
     */
    glyphId: number;
    /**
     * The Unicode code points that this glyph represents. For simple glyphs,
     * this is a single code point. For ligatures (e.g., "ffi"), this contains
     * all constituent code points [0x66, 0x66, 0x69].
     */
    codePoints: number[];
    /**
     * Base horizontal advance in PDF text space units (1/1000 em).
     * Multiply by `font size / 1000` to obtain user space units.
     *
     * This is the default pen movement after rendering this glyph, before
     * any positioning adjustments.
     */
    advance: number;
    /**
     * Adjustment to the horizontal advance (e.g., kerning) in PDF text
     * space units (1/1000 em). Multiply by `font size / 1000` to obtain
     * user space units.
     *
     * Added to `advance` to get the total pen movement. Affects placement
     * of all subsequent glyphs. Negative values bring glyphs closer
     * together.
     */
    advanceAdjust?: number;
    /**
     * Horizontal offset for positioning this glyph (e.g., from GPOS
     * mark-to-base rules) in PDF text space units (1/1000 em).
     *
     * Shifts the glyph's rendering position without affecting the pen
     * advance. Positive values shift right.
     */
    xOffset?: number;
    /**
     * Vertical offset for positioning this glyph (e.g., from GPOS
     * mark-to-base rules) in PDF text space units (1/1000 em).
     *
     * Shifts the glyph's rendering position without affecting the pen
     * advance. Positive values shift up.
     */
    yOffset?: number;
};
/**
 * Returns the width of a shaped glyph run in user space units (points).
 */
export declare function getTextWidth(glyphs: readonly ShapedGlyph[], fontSize: number): number;
export type FontStyle = 'normal' | 'italic' | 'oblique';
/**
 * Represents a font resource within a PDF document.
 */
export declare abstract class PDFFont extends PDFResource {
    /**
     * The full name of the font.
     */
    abstract readonly fontName: string;
    /**
     * The family name of the font.
     */
    abstract readonly familyName: string;
    /**
     * The style of the font, either 'normal', 'italic', or 'oblique'.
     */
    abstract readonly style: FontStyle;
    /**
     * The weight of the font (e.g., 400 for normal, 700 for bold).
     */
    abstract readonly weight: number;
    /**
     * The ascent of the font in PDF text space units (1/1000 em).
     * Multiply by `font size / 1000` to obtain user space units.
     */
    abstract readonly ascent: number;
    /**
     * The descent of the font in PDF text space units (1/1000 em).
     * Multiply by `font size / 1000` to obtain user space units.
     */
    abstract readonly descent: number;
    /**
     * The line gap of the font in PDF text space units (1/1000 em).
     * Multiply by `font size / 1000` to obtain user space units.
     */
    abstract readonly lineGap: number;
    /**
     * Encodes a Unicode text string for use in a PDF content stream with this font.
     */
    abstract shapeText(text: string, opts?: ShapeOptions): ShapedGlyph[];
}