import { ColorStop } from '@acrodata/gradient-parser';
/**
 * Reorder an element at a specified index by condition
 *
 * @param array The original array
 * @param index The element at this index will be checked and moved to its correct sorted location.
 * @param compareWith1 The comparison function used to determine if the element needs to move left.
 * @param compareWith2 The comparison function used to determine if the element needs to move right.
 * @param callback The callback function after the elements have been swapped.
 * @returns
 */
export declare function reorderElementByCondition<T = any>(array?: T[], index?: number, compareWith1?: (a: T, b: T) => boolean, compareWith2?: (a: T, b: T) => boolean, callback?: (newIndex: number) => void): T[];
/**
 * Linearly interpolate between two colors.
 *
 * @param fromColor The starting color in any format supported by TinyColor.
 * @param toColor The ending color in any format supported by TinyColor.
 * @param percentage The interpolation percentage between 0 (`fromColor`) and 1 (`toColor`)
 * @returns
 */
export declare function interpolateColor(fromColor: string, toColor: string, percentage?: number): string;
/**
 * Fill undefined offset in stops.
 *
 * @param stops
 * @returns
 */
export declare function fillUndefinedOffsets(stops: ColorStop[]): ColorStop[];
/**
 * Reverse the color stops array.
 *
 * @param stops
 * @returns
 */
export declare function reverseColorStops(stops: ColorStop[]): ColorStop[];
/**
 * Convert angle to percentage (e.g. `45deg`, `0.25turn`, `3.14rad`, `100grad`).
 *
 * @param value
 * @param unit
 * @returns
 */
export declare function angleToPercentage(value: number, unit: string): number;
/**
 * Convert angle values in the gradient stops array to percentages.
 *
 * @param stops
 * @returns
 */
export declare function convertAngleToPercentage(stops: ColorStop[]): ColorStop[];
export declare const angleUnits: string[];
export declare const lengthUnits: string[];
export declare const positionXKeywords: string[];
export declare const positionYKeywords: string[];
export declare const rectangularColorSpaces: string[];
export declare const polarColorSpaces: string[];
export declare const hueInterpolationMethods: string[];