import { FontFace } from './fontface';
type StringPairs = Map<string, string>;
/**
 * Transforms input raw data of a text-based font file to a font face (@see {@link FontFace}) specification. All
 * referenced pages/glyph atlases will be loaded and setup as well. This is intended to be used directly by the
 * FontFace and is not required to be exposed to webgl-operates public API.
 */
export declare class FontFaceLoader {
    /**
     * Parses the info fields for padding values and stores them in the font face
     * @param stream - The stream of the 'info' identifier.
     * @param fontFace - The font face in which the padding is stored.
     */
    protected static processInfo(stream: Array<string>, fontFace: FontFace): boolean;
    /**
     * Parses the common fields for lineHeight, base, ascent, descent, scaleW and scaleH to store them
     * in the font face. If ascent and/or descent are not available, they can be computed using the largest y-offset
     * (ascent = baseline - max_yoffset) and descent can be derived as well (descent = - fontsize + ascent).
     * @param stream - The stream of the 'common' identifier.
     * @param fontFace - The font face in which the parsed values are stored.
     */
    protected static processCommon(stream: Array<string>, fontFace: FontFace): boolean;
    /**
     * Parses a page to load the associated png-file, i.e., the glyph atlas.
     * @param stream - The stream of the 'page' identifier.
     * @param fontFace - The font face in which the loaded glyph texture is stored.
     * @param url - Uniform resource locator string referencing the fnt-file (used for base path retrieval).
     * @returns - Promise for handling image load status.
     */
    protected static processPage(stream: Array<string>, fontFace: FontFace, url: string): Promise<void> | undefined;
    /**
     * Fetches a single page (e.g., a png-file) for the glyph atlas of a font face.
     * @param fontFace - The font face in which the loaded glyph texture should be stored.
     * @param pageFileUrlsByPageID - Page urls mapped to page IDs.
     * @returns - Promise for handling image load status.
     */
    protected static processPages(fontFace: FontFace, pageFileUrlsByPageID: Map<number, string>): Promise<void> | undefined;
    /**
     * Parses the char fields for character id (code point), x, y, width, height, xoffset, yoffset, xadvance to
     * store them in the font face as instances of Glyph.
     * This relies on fontFace.base and fontFace.glyphTextureExtent, so execute processCommon() first.
     * @param stream - The stream of the 'char' identifier.
     * @param fontFace - The font face in which the loaded glyph texture is stored.
     */
    protected static processChar(stream: Array<string>, fontFace: FontFace): boolean;
    /**
     * Parses the kerning fields for first and second character and the amount, to store them in the font face.
     * @param stream The stream of the 'kerning' identifier.
     * @param fontFace The font face in which the kerning tuples are stored.
     */
    protected static processKerning(stream: Array<string>, fontFace: FontFace): boolean;
    /**
     * Parses to find key-value pairs for given mandatory keys.
     * @param stream - The stream from which the pairs should be read.
     * @param mandatoryKeys - The found pairs are only valid if the mandatory keys are found.
     * @param result - key-value pairs, or undefined if not all mandatory keys are found.
     * @returns - success
     */
    protected static readKeyValuePairs(stream: Array<string>, mandatoryKeys: Array<string>, resultPairs: StringPairs): boolean;
    /**
     * Derives ascent and descent data for the font face. Since the computation is based on the available glyphs and
     * not all of the font's glyphs might be included in the font face, the ascent/descent might be off (based on
     * minimum y-offset).
     * @param fontFace - Font face to find ascent and/or descent for (if missing).
     * @param size - Suggested size of the font face as read from the font file. Note that the actual size of the font
     * face is determined by the sum of ascent and descent (which should equal the font files info size).
     */
    protected static findAscentAndDescentIfNoneProvided(fontFace: FontFace, size: number): void;
    /**
     * Asynchronously loads a fnt-file and provided/referenced pages to create a font face from them.
     * @param fontFace - Font face object to transform data into.
     * @param data - Font face data, probably fetched from an URL.
     * @param url - Uniform resource locator string referencing the fnt-file that was loaded.
     * @param headless - Whether or not to enable headless mode. If enabled, pages are not loaded.
     */
    static process(fontFace: FontFace, data: string, fontFileUrl: string, pageFileUrlsByPageID: undefined | Map<number, string>, headless?: boolean): Promise<FontFace | undefined>;
}
export {};