/**
 * A texture parameter a placeholder stands in for, with the channels of the texture it samples.
 */
export type PlaceholderMap = {
    /**
     * - The name of the texture parameter, such as 'aoMap'.
     */
    name: string;
    /**
     * - The channels the parameter samples, such as 'g', or all of them
     * when not specified.
     */
    channel?: string;
};
/**
 * The 1x1 textures the {@link MaterialHandler} assigns to a texture parameter of a material while
 * its texture asset loads, which the loaded texture then replaces.
 *
 * A placeholder decodes like the texture it stands in for, as it is sRGB and of the type that
 * texture is, so the shader generated for the placeholder is the one the texture needs as well.
 * A placeholder is named after the first of the texture parameters it stands in for, and
 * placeholders named after different parameters are different textures, as a material samples
 * maps holding the same texture from one sampler.
 *
 * The textures are created the first time they are needed, which is when an asset is bound to a
 * material or unloads - never while rendering, where creating a texture is not supported.
 *
 * @ignore
 */
export class PlaceholderTextures {
    /**
     * @param {GraphicsDevice} device - The graphics device the textures are created on, and
     * destroyed with.
     */
    constructor(device: GraphicsDevice);
    /**
     * The graphics device the textures are created on.
     *
     * @type {GraphicsDevice}
     */
    device: GraphicsDevice;
    /**
     * The placeholder textures, by their name.
     *
     * @type {Map<string, Texture>}
     * @private
     */
    private _textures;
    /**
     * The placeholder textures, to recognize one.
     *
     * @type {Set<Texture>}
     * @private
     */
    private _set;
    destroy(): void;
    /**
     * Returns whether a texture is one of the placeholders.
     *
     * @param {Texture|null|undefined} texture - The texture.
     * @returns {boolean} True if the texture is a placeholder.
     */
    has(texture: Texture | null | undefined): boolean;
    /**
     * Returns the placeholder standing in for one texture referenced by the given texture
     * parameters of a material, created on the first request.
     *
     * @param {PlaceholderMap[]} maps - The texture parameters referencing the texture, the first
     * of which names the placeholder.
     * @param {boolean} srgb - Whether the texture it stands in for is sRGB.
     * @param {string} type - The type of the texture it stands in for.
     * @returns {Texture} The placeholder texture.
     */
    get(maps: PlaceholderMap[], srgb: boolean, type: string): Texture;
}
import type { GraphicsDevice } from '../../platform/graphics/graphics-device.js';
import { Texture } from '../../platform/graphics/texture.js';