/// <reference types="webxr" />
import { Context } from "../engine/engine_context.js";
import { Vec3 } from "../engine/engine_types.js";
import { Behaviour } from "./Component.js";
/**
 * ContactShadows is a component that allows to display contact shadows in the scene.
 * @category Rendering
 * @group Components
 */
export declare class ContactShadows extends Behaviour {
    private static readonly _instances;
    /**
     * Create contact shadows for the scene. Automatically fits the shadows to the scene.
     * The instance of contact shadows will be created only once.
     * @param context The context to create the contact shadows in.
     * @returns The instance of the contact shadows.
     */
    static auto(context?: Context): ContactShadows;
    /**
     * When enabled the contact shadows component will be created to fit the whole scene.
     */
    autoFit: boolean;
    /**
     * Darkness of the shadows.
     * @default 0.5
     */
    darkness: number;
    /**
     * Opacity of the shadows.
     * @default 0.5
     */
    opacity: number;
    /**
     * Blur of the shadows.
     * @default 4.0
     */
    blur: number;
    /**
     * When enabled objects will not be visible below the shadow plane
     * @default false
     */
    occludeBelowGround: boolean;
    /**
     * When enabled the backfaces of objects will cast shadows as well.
     * @default true
     */
    backfaceShadows: boolean;
    /**
     * The minimum size of the shadows box
     */
    minSize?: Partial<Vec3>;
    /** All shadow objects are parented to this object.
     * The gameObject itself should not be transformed because we want the ContactShadows object e.g. also have a GroundProjectedEnv component
     * in which case ContactShadows scale would affect the projection
     **/
    private readonly shadowsRoot;
    private shadowCamera?;
    private readonly shadowGroup;
    private renderTarget?;
    private renderTargetBlur?;
    private plane?;
    private occluderMesh?;
    private blurPlane?;
    private depthMaterial?;
    private horizontalBlurMaterial?;
    private verticalBlurMaterial?;
    private textureSize;
    /**
     * Call to fit the shadows to the scene.
     */
    fitShadows(): void;
    /** @internal */
    awake(): void;
    /** @internal */
    start(): void;
    /** @internal */
    onDestroy(): void;
    /** @internal */
    onBeforeRender(_frame: XRFrame | null): void;
    private blurShadow;
    private applyMinSize;
}