import { Texture } from "three";
/** Represents the possible shapes of texture image/source data in three.js.
 * Source.data is typed as `{}` in r183 but at runtime can be ImageBitmap, HTMLImageElement, etc. */
export type TextureImageData = {
    width?: number;
    height?: number;
    depth?: number;
    data?: ArrayBufferView | null;
};
/** Check if a value has image-like dimensions (width/height) */
export declare function hasImageDimensions(value: unknown): value is {
    width: number;
    height: number;
};
/** Check if a value has pixel data (e.g. typed array from a DataTexture) */
export declare function hasPixelData(value: unknown): value is {
    data: ArrayBufferView;
};
/** Get the source data of a texture, typed for dimension/data access */
export declare function getSourceData(tex: Texture): TextureImageData | null;
/** Get the image of a texture, typed for dimension/data access.
 * In r183, Texture.image is typed as `{}` but at runtime is an ImageBitmap, HTMLImageElement, etc. */
export declare function getTextureImage(tex: Texture): TextureImageData | null;
/** Get width/height of a texture from image or source data */
export declare function getTextureDimensions(tex: Texture): {
    width: number;
    height: number;
};
export declare function isDebugMode(): string | boolean;
export declare function getParam(name: string): boolean | string;
export declare function resolveUrl(source: string | undefined, uri: string): string;
/** Check if the current device is a mobile device.
 * @returns `true` if it's a phone or tablet
 */
export declare function isMobileDevice(): boolean;
/**
 * Check if we are running in a development server (localhost or ip address).
 * @returns `true` if we are running in a development server (localhost or ip address).
 */
export declare function isDevelopmentServer(): boolean;
export type SlotReturnValue<T = any> = {
    use?: ((promise: Promise<T>) => void);
};
/**
 * A promise queue that limits the number of concurrent promises.
 * Use the `slot` method to request a slot for a promise with a specific key. The returned promise resolves to an object with a `use` method that can be called to add the promise to the queue.
 */
export declare class PromiseQueue<T = any> {
    maxConcurrent: number;
    private readonly _running;
    private readonly _queue;
    debug: boolean;
    constructor(maxConcurrent: number, opts?: {
        debug?: boolean;
    });
    private tick;
    /**
     * Request a slot for a promise with a specific key. This function returns a promise with a `use` method that can be called to add the promise to the queue.
     */
    slot(key: string): Promise<SlotReturnValue<T>>;
    private add;
    private internalUpdate;
}
export declare function determineTextureMemoryInBytes(texture: Texture): number;
/**
 * Detect the GPU memory of the current device. This is a very rough estimate based on the renderer information, and may not be accurate. It returns the estimated memory in MB, or `undefined` if it cannot be detected.
 */
export declare function detectGPUMemory(): number | undefined;