import Color from "@arcgis/core/Color";
import type { ColorJson } from "@vertigis/arcgis-extensions/json/SymbolJson";
export declare const TRANSPARENT: Color;
export declare const WCAG_AA_CONTRAST_RATIO = 4.5;
/**
 * Defines a color by its hue, saturation, and value (brightness). Property
 * values range from 0..1.
 */
export interface Hsv {
    /**
     * Hue.
     */
    h: number;
    /**
     * Saturation.
     */
    s: number;
    /**
     * Value (brightness).
     */
    v: number;
    /**
     * Alpha (transparency).
     */
    a?: number;
}
/**
 * Defines a color by red, green, and blue values. Property values range from
 * 0..1.
 */
export interface Rgb {
    /**
     * Red.
     */
    r: number;
    /**
     * Green.
     */
    g: number;
    /**
     * Blue.
     */
    b: number;
    /**
     * Alpha (transparency).
     */
    a?: number;
}
/**
 * The result of createContrastColor().
 */
export interface ContrastColorResult {
    /**
     * The contrast ratio between the original input color and the color in this
     * result.
     */
    ratio: number;
    /**
     * The new contrast color.
     */
    color: Color;
}
/**
 * Returns whether two ESRI Colors have the same RGBA values.
 *
 * @param color1 The first color.
 * @param color2 The second color.
 * @param ignoreA Whether to ignore the alpha value when comparing. Default is
 *   false.
 */
export declare function colorsAreEqual(color1: Color, color2: Color, ignoreA?: boolean): boolean;
/**
 * Converts from one of several formats to a Color object.
 *
 * @param value The value to convert. Supported formats are:
 *
 *   - Hex string
 *   - "rgb()" or "rgba()" string
 *   - Number array (JSON format)
 *   - Object with r, g, b, and a properties.
 */
export declare function toColor(value: unknown): Color;
/**
 * Converts a color to an "rgba(...)" string.
 *
 * @param color The color to convert.
 */
export declare function toRgbaString(color: Color): string;
/**
 * Converts a color to an "rgb(...)" string.
 *
 * @param color The color to convert.
 */
export declare function toRgbString(color: Color): string;
/**
 * Lightens or darkens a color to create a new color that contrasts with the
 * original. This function yields a color whose contrast ratio is >= 4.5 making
 * it WCAG AA compliant. Prefers a light contrast color over a dark contrast
 * color if both are WCAG AA compliant.
 *
 * @param color The input color from which to generate a contrasting color.
 */
export declare function createContrastColor(color: Color): ContrastColorResult;
/**
 * Darkens the color by an amount and returns the new color.
 *
 * @param amount Ranges from 0..1.
 * @param color The color to darken.
 */
export declare function darken(amount: number, color: Color): Color;
/**
 * Lightens the color by an amount and returns the new color.
 *
 * @param amount Ranges from 0..1.
 * @param color The color to lighten.
 */
export declare function lighten(amount: number, color: Color): Color;
/**
 * Blend a color with another by an amount and return a new color. Uses linear
 * interpolation in the RGB colorspace.
 *
 * @param color The original color.
 * @param blendWith The color to blend with.
 * @param amount Ranges from 0..1.
 */
export declare function blend(color: Color, blendWith: Color, amount: number): Color;
/**
 * Calculates the contrast ratio between two colors.
 *
 * @param foregroundColor The foreground color.
 * @param backgroundColor The background color.
 * @returns A contrast ratio value in the range 0..21.
 */
export declare function getContrastRatio(foregroundColor: Color, backgroundColor: Color): number;
/**
 * Choose between a light and dark text color by comparing the contrast to the
 * background color. The light color will be preferred as long as it exceeds the
 * WCAG AA contrast ratio threshold.
 *
 * @param background The background color to compare against.
 * @param lightColor The light color option.
 * @param darkColor The dark color option.
 */
export declare function getContrastText(background: Color, lightColor: Color, darkColor: Color): Color;
/**
 * Returns the raw RGB values of the color See
 * https://en.wikipedia.org/wiki/HSL_and_HSV#Converting_to_RGB for a detailed
 * discussion of this algorithm.
 *
 * @param color The color to convert.
 */
export declare function hsvToRgb(color: Hsv): Rgb;
/**
 * Convert HSV to an instance of EsriColor.
 *
 * @param color The HSV value to convert.
 */
export declare function hsvToColor(color: Hsv): Color;
/**
 * Convert from an instance of EsriColor to HSV.
 *
 * @param color The Color value to convert.
 */
export declare function colorToHsv(color: Color): Hsv;
/**
 * Converts a Color to rgba number array, values ranging from 0..1.
 *
 * @param color The color to convert.
 */
export declare function colorToDecimalRgb(color: Color): number[];
/**
 * Converts raw RGB values to their HSV equivalents. Reverse of the above Also
 * discussed on this page: https://en.wikipedia.org/wiki/HSL_and_HSV.
 *
 * @param color The color to convert.
 */
export declare function decimalRgbToHsv(color: number[]): Hsv;
/**
 * Generates random colors in [r, g, b, a] format. Uses evenly spaced hues
 * around the color wheel with some variation in saturation and brightness.
 *
 * @param count The number of colors to generate.
 */
export declare function generateRandomColors(count: number): ColorJson[];