@gltf-transform/core

import type { PropertyType } from './constants.js'; import type { Document } from './document.js'; import type { ReaderContext, WriterContext } from './io/index.js'; import { ExtensionProperty } from './properties/index.js'; /** * *Base class for all Extensions.* * * Extensions enhance a glTF {@link Document} with additional features and schema, beyond the core * glTF specification. Common extensions may be imported from the `@gltf-transform/extensions` * package, or custom extensions may be created by extending this base class. * * An extension is added to a Document by calling {@link Document.createExtension} with the * extension constructor. The extension object may then be used to construct * {@link ExtensionProperty} instances, which are attached to properties throughout the Document * as prescribed by the extension itself. * * For more information on available extensions and their usage, see [Extensions](/extensions). * * Reference: * - [glTF → Extensions](https://github.com/KhronosGroup/gltf/blob/main/specification/2.0/README.md#specifying-extensions) * - [glTF Extension Registry](https://github.com/KhronosGroup/gltf/blob/main/extensions) * * @category Extensions */ export declare abstract class Extension { /** Official name of the extension. */ static EXTENSION_NAME: string; /** Official name of the extension. */ readonly extensionName: string; /** * Before reading, extension should be called for these {@link Property} types. *Most * extensions don't need to implement this.* * @hidden */ readonly prereadTypes: PropertyType[]; /** * Before writing, extension should be called for these {@link Property} types. *Most * extensions don't need to implement this.* * @hidden */ readonly prewriteTypes: PropertyType[]; /** @hidden Dependency IDs needed to read this extension, to be installed before I/O. */ readonly readDependencies: string[]; /** @hidden Dependency IDs needed to write this extension, to be installed before I/O. */ readonly writeDependencies: string[]; /** @hidden */ protected readonly document: Document; /** @hidden */ protected required: boolean; /** @hidden */ protected properties: Set<ExtensionProperty>; /** @hidden */ private _listener; /** @hidden */ constructor(document: Document); /** Disables and removes the extension from the Document. */ dispose(): void; /** @hidden Performs first-time setup for the extension. Must be idempotent. */ static register(): void; /** * Indicates to the client whether it is OK to load the asset when this extension is not * recognized. Optional extensions are generally preferred, if there is not a good reason * to require a client to completely fail when an extension isn't known. */ isRequired(): boolean; /** * Indicates to the client whether it is OK to load the asset when this extension is not * recognized. Optional extensions are generally preferred, if there is not a good reason * to require a client to completely fail when an extension isn't known. */ setRequired(required: boolean): this; /** * Lists all {@link ExtensionProperty} instances associated with, or created by, this * extension. Includes only instances that are attached to the Document's graph; detached * instances will be excluded. */ listProperties(): ExtensionProperty[]; /********************************************************************************************** * I/O implementation. */ /** @hidden Installs dependencies required by the extension. */ install(_key: string, _dependency: unknown): this; /** * Used by the {@link PlatformIO} utilities when reading a glTF asset. This method may * optionally be implemented by an extension, and should then support any property type * declared by the Extension's {@link Extension.prereadTypes} list. The Extension will * be given a ReaderContext instance, and is expected to update either the context or its * {@link JSONDocument} with resources known to the Extension. *Most extensions don't need to * implement this.* * @hidden */ preread(_readerContext: ReaderContext, _propertyType: PropertyType): this; /** * Used by the {@link PlatformIO} utilities when writing a glTF asset. This method may * optionally be implemented by an extension, and should then support any property type * declared by the Extension's {@link Extension.prewriteTypes} list. The Extension will * be given a WriterContext instance, and is expected to update either the context or its * {@link JSONDocument} with resources known to the Extension. *Most extensions don't need to * implement this.* * @hidden */ prewrite(_writerContext: WriterContext, _propertyType: PropertyType): this; /** * Used by the {@link PlatformIO} utilities when reading a glTF asset. This method must be * implemented by each extension in order to support reading files. The extension will be * given a ReaderContext instance, and should update the current {@link Document} accordingly. * @hidden */ abstract read(readerContext: ReaderContext): this; /** * Used by the {@link PlatformIO} utilities when writing a glTF asset. This method must be * implemented by each extension in order to support writing files. The extension will be * given a WriterContext instance, and should modify the {@link JSONDocument} output * accordingly. Adding the extension name to the `extensionsUsed` and `extensionsRequired` list * is done automatically, and should not be included here. * @hidden */ abstract write(writerContext: WriterContext): this; }