export type RendererTier = "webgl" | "canvas" | "dom";
export type RendererAddon = {
    dispose: () => void;
};
/** A loader constructs + `loadAddon`s its renderer, wiring `onLoss` to the
 *  addon's context-loss event, and throws if the renderer can't initialize. */
export type RendererLoaders = {
    webgl?: ((onLoss: () => void) => Promise<RendererAddon>) | undefined;
    canvas?: (() => Promise<RendererAddon>) | undefined;
};
/** The next lower renderer tier, or null at the bottom (DOM). Pure. */
export declare function nextRendererTier(tier: RendererTier): RendererTier | null;
/**
 * Attach the highest renderer tier at or below `prefer` that initializes,
 * reporting the settled tier via `onTier`. On a WebGL/canvas context loss the
 * loader's `onLoss` re-enters at the next tier down, so `onTier` is called again
 * with the downgraded tier. Returns the tier chosen on this pass.
 */
export declare function attachRenderer(prefer: RendererTier, loaders: RendererLoaders, onTier: (tier: RendererTier) => void): Promise<RendererTier>;