import { ReaderContext, Texture, WriterContext } from '@gltf-transform/core';
import { GLTF } from '@gltf-transform/core';
export declare function tryGetInArray<T>(arr: Array<T> | undefined | null, index: number | undefined): T | null;
export declare function writeExtension(prop: GLTF.IProperty | null, name: string, ext: any): void;
export declare function getTexture(context: ReaderContext, tex: GLTF.ITexture): Texture;
/** Resolve the image source index from a texture definition, checking `texDef.source`
 *  and then iterating all extension keys for a `.source` property. */
export declare function findSource(texDef: GLTF.ITexture): number | undefined;
export declare function getTextureDefinition(context: WriterContext | ReaderContext, tex: Texture): GLTF.ITexture | null;