import type { Reader } from "../../font/binary/reader.ts";
import type { Tag, uint16 } from "../../types.ts";
/**
 * FeatureVariations table
 * Allows different feature substitutions based on variation axis coordinates
 * Used in GSUB/GPOS for variable fonts
 */
export interface FeatureVariations {
    majorVersion: number;
    minorVersion: number;
    featureVariationRecords: FeatureVariationRecord[];
}
/**
 * Feature variation record
 * Contains a condition set and feature substitutions to apply when conditions are met
 */
export interface FeatureVariationRecord {
    conditionSet: ConditionSet;
    featureTableSubstitution: FeatureTableSubstitution;
}
/**
 * Condition set - all conditions must be met
 */
export interface ConditionSet {
    conditions: Condition[];
}
/**
 * Single axis condition
 */
export interface Condition {
    format: number;
    axisIndex: uint16;
    filterRangeMinValue: number;
    filterRangeMaxValue: number;
}
/**
 * Feature table substitution
 * Maps feature indices to replacement feature tables
 */
export interface FeatureTableSubstitution {
    majorVersion: number;
    minorVersion: number;
    substitutions: FeatureSubstitutionRecord[];
}
/**
 * Single feature substitution record
 */
export interface FeatureSubstitutionRecord {
    featureIndex: uint16;
    alternateFeature: AlternateFeature;
}
/**
 * Alternate feature table
 */
export interface AlternateFeature {
    featureParamsOffset: uint16;
    lookupListIndices: uint16[];
}
/**
 * Parse FeatureVariations table
 */
export declare function parseFeatureVariations(reader: Reader): FeatureVariations;
/**
 * Evaluate condition set against axis coordinates
 * Returns true if all conditions are met
 */
export declare function evaluateConditionSet(conditionSet: ConditionSet, axisCoords: number[]): boolean;
/**
 * Find matching feature variation record for given axis coordinates
 * Returns the first matching record, or null if none match
 */
export declare function findMatchingFeatureVariation(featureVariations: FeatureVariations, axisCoords: number[]): FeatureVariationRecord | null;
/**
 * Get substituted lookup list indices for a feature
 * Returns the original lookups if no substitution applies
 */
export declare function getSubstitutedLookups(featureVariations: FeatureVariations | null, featureIndex: number, originalLookups: uint16[], axisCoords: number[] | null): uint16[];
/**
 * Apply feature variations to a feature list
 * Returns a modified feature list with substituted lookup indices
 */
export declare function applyFeatureVariations(featureVariations: FeatureVariations | null, featureLookups: Map<Tag, uint16[]>, featureIndices: Map<Tag, number>, axisCoords: number[] | null): Map<Tag, uint16[]>;