/**
 * Keyframe is a representation of a keyframe in an AnimationCurve.
 */
export declare class Keyframe {
    time: number;
    value: number;
    inTangent: number;
    inWeight?: number;
    outTangent: number;
    outWeight?: number;
    weightedMode?: number;
    constructor(time?: number, value?: number);
}
/**
 * AnimationCurve is a representation of a curve that can be used to animate values over time.
 *
 * @category Animation
 * @group Utilities
 */
export declare class AnimationCurve {
    /**
     * Creates an animation curve that goes from the `from` value to the `to` value over the given `duration`.
     */
    static linearFromTo(from: number, to: number, duration: number): AnimationCurve;
    /** Creates an animation curve with just one keyframe */
    static constant(value: number): AnimationCurve;
    /**
     * The keyframes that define the curve.
    */
    keys: Array<Keyframe>;
    /**
     * Clones this AnimationCurve and returns a new instance with the same keyframes (the keyframes are also cloned).
    */
    clone(): AnimationCurve;
    /** The duration of the curve, which is the time of the last keyframe. */
    get duration(): number;
    /** Evaluates the curve at the given time and returns the value of the curve at that time.
     * @param time The time at which to evaluate the curve.
     * @returns The value of the curve at the given time.
     */
    evaluate(time: number): number;
    static interpolateValue(time: number, keyframe1: Keyframe, keyframe2: Keyframe): number;
}