import type { DirectionalLightingConfig, LightingConfig } from "../game/playableGame.js";
/** Ambient multiplier applied under image-based light when `iblAmbientScale` is unset. */
export declare const DEFAULT_IBL_AMBIENT_SCALE = 0.5;
/** Soft key added when authored lighting has no directional light: high, off to one side, shadowless. */
export declare const FALLBACK_KEY_LIGHT: Readonly<DirectionalLightingConfig>;
/**
 * Rebalance authored lighting for a scene that also has image-based light: trim the flat ambient term
 * by `iblAmbientScale` (default 0.5) and, when no directional light is authored, add
 * {@link FALLBACK_KEY_LIGHT} tinted by the ambient colour so forms keep a lit and a shaded side.
 * Returns the input unchanged when there is nothing to adjust.
 * @capability balance-ibl-lighting trim flat ambient under IBL and add a key light to directionless lighting
 */
export declare function balanceLightingForIbl(lighting: LightingConfig | undefined): LightingConfig | undefined;