/**
 * @license
 * Copyright 2021 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { Cam16 } from './cam16.js';
/**
 * A class that solves the HCT equation.
 */
export declare class HctSolver {
    static SCALED_DISCOUNT_FROM_LINRGB: number[][];
    static LINRGB_FROM_SCALED_DISCOUNT: number[][];
    static Y_FROM_LINRGB: number[];
    static CRITICAL_PLANES: number[];
    /**
     * Sanitizes a small enough angle in radians.
     *
     * @param angle An angle in radians; must not deviate too much
     * from 0.
     * @return A coterminal angle between 0 and 2pi.
     */
    private static sanitizeRadians;
    /**
     * Delinearizes an RGB component, returning a floating-point
     * number.
     *
     * @param rgbComponent 0.0 <= rgb_component <= 100.0, represents
     * linear R/G/B channel
     * @return 0.0 <= output <= 255.0, color channel converted to
     * regular RGB space
     */
    private static trueDelinearized;
    private static chromaticAdaptation;
    /**
     * Returns the hue of a linear RGB color in CAM16.
     *
     * @param linrgb The linear RGB coordinates of a color.
     * @return The hue of the color in CAM16, in radians.
     */
    private static hueOf;
    private static areInCyclicOrder;
    /**
     * Solves the lerp equation.
     *
     * @param source The starting number.
     * @param mid The number in the middle.
     * @param target The ending number.
     * @return A number t such that lerp(source, target, t) = mid.
     */
    private static intercept;
    private static lerpPoint;
    /**
     * Intersects a segment with a plane.
     *
     * @param source The coordinates of point A.
     * @param coordinate The R-, G-, or B-coordinate of the plane.
     * @param target The coordinates of point B.
     * @param axis The axis the plane is perpendicular with. (0: R, 1:
     * G, 2: B)
     * @return The intersection point of the segment AB with the plane
     * R=coordinate, G=coordinate, or B=coordinate
     */
    private static setCoordinate;
    private static isBounded;
    /**
     * Returns the nth possible vertex of the polygonal intersection.
     *
     * @param y The Y value of the plane.
     * @param n The zero-based index of the point. 0 <= n <= 11.
     * @return The nth possible vertex of the polygonal intersection
     * of the y plane and the RGB cube, in linear RGB coordinates, if
     * it exists. If this possible vertex lies outside of the cube,
     * [-1.0, -1.0, -1.0] is returned.
     */
    private static nthVertex;
    /**
     * Finds the segment containing the desired color.
     *
     * @param y The Y value of the color.
     * @param targetHue The hue of the color.
     * @return A list of two sets of linear RGB coordinates, each
     * corresponding to an endpoint of the segment containing the
     * desired color.
     */
    private static bisectToSegment;
    private static midpoint;
    private static criticalPlaneBelow;
    private static criticalPlaneAbove;
    /**
     * Finds a color with the given Y and hue on the boundary of the
     * cube.
     *
     * @param y The Y value of the color.
     * @param targetHue The hue of the color.
     * @return The desired color, in linear RGB coordinates.
     */
    private static bisectToLimit;
    private static inverseChromaticAdaptation;
    /**
     * Finds a color with the given hue, chroma, and Y.
     *
     * @param hueRadians The desired hue in radians.
     * @param chroma The desired chroma.
     * @param y The desired Y.
     * @return The desired color as a hexadecimal integer, if found; 0
     * otherwise.
     */
    private static findResultByJ;
    /**
     * Finds an sRGB color with the given hue, chroma, and L*, if
     * possible.
     *
     * @param hueDegrees The desired hue, in degrees.
     * @param chroma The desired chroma.
     * @param lstar The desired L*.
     * @return A hexadecimal representing the sRGB color. The color
     * has sufficiently close hue, chroma, and L* to the desired
     * values, if possible; otherwise, the hue and L* will be
     * sufficiently close, and chroma will be maximized.
     */
    static solveToInt(hueDegrees: number, chroma: number, lstar: number): number;
    /**
     * Finds an sRGB color with the given hue, chroma, and L*, if
     * possible.
     *
     * @param hueDegrees The desired hue, in degrees.
     * @param chroma The desired chroma.
     * @param lstar The desired L*.
     * @return An CAM16 object representing the sRGB color. The color
     * has sufficiently close hue, chroma, and L* to the desired
     * values, if possible; otherwise, the hue and L* will be
     * sufficiently close, and chroma will be maximized.
     */
    static solveToCam(hueDegrees: number, chroma: number, lstar: number): Cam16;
}