import type { GlyphId, int16, uint16, uint32 } from "../../types.ts";
import type { Reader } from "../binary/reader.ts";
/**
 * Extended Kerning table (kerx)
 * Apple Advanced Typography kerning
 */
export interface KerxTable {
    version: uint16;
    nTables: uint32;
    subtables: KerxSubtable[];
}
/**
 * kerx subtable types
 */
export declare enum KerxSubtableType {
    OrderedList = 0,
    StateTable = 1,
    SimpleArray = 2,
    ControlPoint = 4,
    Format6 = 6
}
/**
 * Coverage flags
 */
export interface KerxCoverage {
    vertical: boolean;
    crossStream: boolean;
    variation: boolean;
}
/**
 * Base subtable
 */
export interface KerxSubtableBase {
    length: uint32;
    coverage: KerxCoverage;
    tupleCount: uint16;
}
export type KerxSubtable = KerxOrderedListSubtable | KerxStateTableSubtable | KerxSimpleArraySubtable | KerxControlPointSubtable | KerxFormat6Subtable;
/**
 * Format 0: Ordered list of kerning pairs
 */
export interface KerxOrderedListSubtable extends KerxSubtableBase {
    format: KerxSubtableType.OrderedList;
    nPairs: uint32;
    pairs: KerxPair[];
}
export interface KerxPair {
    left: GlyphId;
    right: GlyphId;
    value: int16;
}
/**
 * Format 1: State table
 */
export interface KerxStateTableSubtable extends KerxSubtableBase {
    format: KerxSubtableType.StateTable;
    stateHeader: KerxStateHeader;
}
export interface KerxStateHeader {
    nClasses: uint32;
    classTableOffset: uint32;
    stateArrayOffset: uint32;
    entryTableOffset: uint32;
    valueTableOffset: uint32;
}
/**
 * Format 2: Simple array
 */
export interface KerxSimpleArraySubtable extends KerxSubtableBase {
    format: KerxSubtableType.SimpleArray;
    rowWidth: uint16;
    leftClassTable: KerxClassTable;
    rightClassTable: KerxClassTable;
    kerningArray: Int16Array;
}
export interface KerxClassTable {
    firstGlyph: GlyphId;
    nGlyphs: uint16;
    classes: Uint8Array;
}
/**
 * Format 4: Control point actions
 */
export interface KerxControlPointSubtable extends KerxSubtableBase {
    format: KerxSubtableType.ControlPoint;
    flags: uint32;
}
/**
 * Format 6: Extended kerning pairs
 */
export interface KerxFormat6Subtable extends KerxSubtableBase {
    format: KerxSubtableType.Format6;
    flags: uint32;
    rowCount: uint16;
    columnCount: uint16;
    rowIndexTableOffset: uint32;
    columnIndexTableOffset: uint32;
    kerningArrayOffset: uint32;
    kerningVectorOffset: uint32;
}
/**
 * Parse kerx table
 */
export declare function parseKerx(reader: Reader): KerxTable;
/**
 * Get kerning value from kerx table
 */
export declare function getKerxValue(kerx: KerxTable, left: GlyphId, right: GlyphId): number;