import { Extension, PropertyType, type ReaderContext, type WriterContext } from '@gltf-transform/core';
import { KHR_MATERIALS_EMISSIVE_STRENGTH } from '../constants.js';
import { EmissiveStrength } from './emissive-strength.js';
/**
 * [KHR_materials_emissive_strength](https://github.com/KhronosGroup/gltf/blob/main/extensions/2.0/Khronos/KHR_materials_emissive_strength/)
 * defines emissive strength and enables high-dynamic-range (HDR) emissive materials.
 *
 * ![Illustration](/media/extensions/khr-materials-emissive-strength.jpg)
 *
 * > _**Figure:** Cubes with emissive color #59BCF3 and emissive strength
 * > increasing from 1 to 256 nits, left to right. Rendered in [three.js](https://threejs.org/),
 * > with independent point lighting and a bloom effect.
 * > Source: [Don McCurdy](https://www.donmccurdy.com/2024/04/27/emission-and-bloom/)._
 *
 * The core glTF 2.0 material model includes {@link Material.setEmissiveFactor `emissiveFactor`}
 * and {@link Material.setEmissiveTexture `emissiveTexture`} to control the color and intensity
 * of the light being emitted by the material, clamped to the range [0.0, 1.0]. However, in
 * PBR environments with HDR reflections and lighting, stronger emission effects may be desirable.
 *
 * In this extension, a new {@link EmissiveStrength.setEmissiveStrength `emissiveStrength`} scalar
 * factor is supplied, which governs the upper limit of emissive strength per material and may be
 * given arbitrarily high values.
 *
 * For implementations where a physical light unit is needed, the units for the multiplicative
 * product of the emissive texture and factor are candela per square meter (cd / m2), sometimes
 * called _nits_. Many realtime rendering engines simplify this calculation by assuming that an
 * emissive factor of 1.0 results in a fully exposed pixel.
 *
 * Properties:
 * - {@link EmissiveStrength}
 *
 * ### Example
 *
 * ```typescript
 * import { KHRMaterialsEmissiveStrength, EmissiveStrength } from '@gltf-transform/extensions';
 *
 * // Create an Extension attached to the Document.
 * const emissiveStrengthExtension = document.createExtension(KHRMaterialsEmissiveStrength);
 *
 * // Create EmissiveStrength property.
 * const emissiveStrength = emissiveStrengthExtension
 * 	.createEmissiveStrength().setEmissiveStrength(5.0);
 *
 * // Assign to a Material.
 * material.setExtension('KHR_materials_emissive_strength', emissiveStrength);
 * ```
 */
export declare class KHRMaterialsEmissiveStrength extends Extension {
    static readonly EXTENSION_NAME: typeof KHR_MATERIALS_EMISSIVE_STRENGTH;
    readonly extensionName: typeof KHR_MATERIALS_EMISSIVE_STRENGTH;
    readonly prereadTypes: PropertyType[];
    readonly prewriteTypes: PropertyType[];
    /** Creates a new EmissiveStrength property for use on a {@link Material}. */
    createEmissiveStrength(): EmissiveStrength;
    /** @hidden */
    read(_context: ReaderContext): this;
    /** @hidden */
    write(_context: WriterContext): this;
    /** @hidden */
    preread(context: ReaderContext): this;
    /** @hidden */
    prewrite(context: WriterContext): this;
}