export interface EffectFrame {
    /** The 2D context. Or null when `context: null` (WebGL/Three effects own
     * their renderer and read `canvas` instead). */
    ctx: CanvasRenderingContext2D | null;
    canvas: HTMLCanvasElement;
    /** Canvas size in CSS pixels (already DPR-scaled on the 2D context). */
    width: number;
    height: number;
    dpr: number;
    /** Live `prefers-reduced-motion` state: damp or freeze your motion. */
    reducedMotion: boolean;
}
export interface EffectOptions {
    /** Runs once, after the first layout size is known. Build your state here;
     * return a function to dispose it (GPU buffers, renderers) on destroy. */
    setup?: (fx: EffectFrame) => void | (() => void);
    /** One simulation step. `dt` is seconds since last frame, clamped to 50ms. */
    frame: (fx: EffectFrame, dt: number) => void;
    /** Called after a resize (fx fields already updated). */
    resize?: (fx: EffectFrame) => void;
    /** Max device-pixel-ratio (default 2. Beyond that it's just heat). */
    dprCap?: number;
    /** `'2d'` (default) grabs and DPR-scales a 2D context. `null` grabs
     * nothing: for WebGL/Three: create your own renderer on `fx.canvas`
     * (the harness still sizes the backing store and runs the lifecycle). */
    context?: '2d' | null;
    /** Pause automatically when offscreen, zero-area or tab hidden (default true). */
    autoPause?: boolean;
}
export interface EffectHandle {
    pause: () => void;
    resume: () => void;
    destroy: () => void;
}
export declare function mountEffect(canvas: HTMLCanvasElement, { setup, frame, resize, dprCap, autoPause, context }: EffectOptions): EffectHandle;