/** Colorblind simulation/daltonization modes the engine ships matrices for. */
export type ColorblindMode = "none" | "protanopia" | "deuteranopia" | "tritanopia" | "grayscale";
/** Serializable accessibility preferences a game reads to adapt its presentation. */
export interface AccessibilityState {
    /** Suppress non-essential motion/animation. */
    reducedMotion: boolean;
    /** Boost contrast (stronger borders/backgrounds, less transparency). */
    highContrast: boolean;
    /** UI text scale multiplier (`1` = default). See {@link clampTextScale} for bounds. */
    textScale: number;
    /** Colorblind filter applied to the presentation. */
    colorblind: ColorblindMode;
    /** Show subtitles/captions for dialogue and important audio. */
    captions: boolean;
}
/** The out-of-the-box accessibility state (all assistance off, `textScale` 1). */
export declare const DEFAULT_ACCESSIBILITY: AccessibilityState;
/** Minimum UI text scale. */
export declare const TEXT_SCALE_MIN = 0.75;
/** Maximum UI text scale. */
export declare const TEXT_SCALE_MAX = 2;
/** Clamp a text-scale multiplier into the supported `[TEXT_SCALE_MIN, TEXT_SCALE_MAX]` range. */
export declare function clampTextScale(scale: number): number;
/** Return `ms` when motion is allowed, or `reduced` (default 0) when `reducedMotion` is set — the animation-duration gate. */
export declare function reducedMotionDuration(state: AccessibilityState, ms: number, reduced?: number): number;
/**
 * `feColorMatrix` `values` strings for each colorblind mode — simulate how a
 * viewer with that condition perceives color (and a grayscale mode). `"none"`
 * maps to `null` (no filter). Consumed by the React `ColorblindFilters` defs.
 */
export declare const COLORBLIND_MATRICES: Record<ColorblindMode, string | null>;
/**
 * The CSS filter that applies `mode` to one rendered frame — a `url(#jg-cb-<mode>)` reference to the
 * `feColorMatrix` defs {@link COLORBLIND_MATRICES} drives. `"none"` maps to `null` (no filter), so a
 * caller can spread it onto the canvas alone and leave HUD and menu text at its own contrast.
 *
 * @capability colorblind-frame-filter resolve a colorblind mode to the CSS filter for the 3D frame alone
 */
export declare function colorblindFrameFilter(mode: ColorblindMode): string | null;
/** Observable, serializable accessibility-preferences store. */
export interface AccessibilityStore {
    get(): AccessibilityState;
    /** Merge a partial update (text scale is clamped); notifies on an actual change. */
    set(patch: Partial<AccessibilityState>): void;
    /** Restore defaults. */
    reset(): void;
    subscribe(listener: () => void): () => void;
    snapshot(): AccessibilityState;
    restore(snapshot: Partial<AccessibilityState>): void;
}
/**
 * Serializable, observable store of accessibility preferences (reduced motion,
 * high contrast, text scale, colorblind mode, captions). Genre-agnostic plumbing
 * like input rebinding — a game binds these to its settings UI and adapts its
 * presentation; `snapshot`/`restore` round-trip through a save or settings blob.
 *
 * @capability accessibility-store serializable, observable accessibility preferences (reduced motion, high contrast, text scale, colorblind mode, captions) a game binds to its settings and presentation
 */
export declare function createAccessibilityStore(initial?: Partial<AccessibilityState>): AccessibilityStore;