import { Extension, PropertyType, ReaderContext, WriterContext } from '@gltf-transform/core';
/**
 * NEEDLE_lightmaps gltf-transform extension.
 *
 * Handles both embedded (`/textures/N` pointer) and external (`sunrise.exr` pointer) lightmaps.
 *
 * - **preread(TEXTURE)**: Injects external EXR files into the JSON document so the core reader
 *   creates proper Texture objects from them.
 * - **read()**: Resolves `/textures/N` pointers to Texture objects. Sets references so that
 *   gltf-transform doesn't prune/dedup referenced textures.
 * - **write()**: Updates pointer strings:
 *   - Embedded textures: resolves to the new `/textures/N` index in the output.
 *   - External textures: uses the Texture's current URI (e.g. updated by PMREM to `.pmrem.ktx2`).
 */
export declare class NEEDLE_lightmaps_ext extends Extension {
    static readonly EXTENSION_NAME = "NEEDLE_lightmaps";
    readonly extensionName = "NEEDLE_lightmaps";
    readonly prereadTypes: PropertyType[];
    readonly prewriteTypes: PropertyType[];
    /** The raw extension JSON from the input (mutated in-place during write) */
    private extensionData;
    /** Entries with resolved Texture references */
    private resolved;
    /** Image indices injected during preread (for external EXR files) */
    private injectedImageIndices;
    /** The ExtensionProperty that holds references to prevent dedup/prune */
    private lightmapProp;
    preread(context: ReaderContext, _propertyType: PropertyType): this;
    read(context: ReaderContext): this;
    prewrite(context: WriterContext, _propertyType: PropertyType): this;
    write(context: WriterContext): this;
    private pointersResolved;
    private resolvePointers;
    /**
     * Find (or create) a texture def in the output JSON that references the given Texture.
     * This replicates the logic from the opaque system's TextureIndexResolver.
     */
    private findOrCreateTextureIndex;
}