export type GSplatVaryingDescriptor = {
    /**
     * - The varying name. Must be a valid shader identifier.
     */
    name: string;
    /**
     * - The component data type: {@link TYPE_FLOAT32}, {@link TYPE_INT32} or
     * {@link TYPE_UINT32}.
     */
    type: number;
    /**
     * - The number of components, 1 to 4.
     */
    components: number;
};
/**
 * Manages custom varying streams for the gsplat render customization. Streams added here generate
 * set functions available to the `gsplatModifyVS` shader chunk, where they run once per splat,
 * and matching get functions available to the `gsplatModifyPS` shader chunk, where the per-splat
 * value can be read for each rendered fragment.
 *
 * Access the instance via {@link GSplatParams#varyings}.
 *
 * @category Graphics
 */
export class GSplatVaryings {
    /**
     * Creates a new GSplatVaryings instance.
     *
     * @param {GraphicsDevice} device - The graphics device.
     * @ignore
     */
    constructor(device: GraphicsDevice);
    /**
     * @type {GraphicsDevice}
     * @private
     */
    private _device;
    /**
     * @type {GSplatVaryingDescriptor[]}
     * @private
     */
    private _streams;
    /**
     * @type {number}
     * @private
     */
    private _words;
    /**
     * @type {number}
     * @private
     */
    private _version;
    /**
     * Gets the varying stream descriptors. Do not modify the returned array.
     *
     * @type {GSplatVaryingDescriptor[]}
     */
    get streams(): GSplatVaryingDescriptor[];
    /**
     * The number of u32 words the varying streams add to the per-splat projection cache of the
     * {@link GSPLAT_RENDERER_RASTER_GPU_SORT} renderer.
     *
     * @type {number}
     * @ignore
     */
    get words(): number;
    /**
     * The version of the varying streams, incremented on every change.
     *
     * @type {number}
     * @ignore
     */
    get version(): number;
    /**
     * Adds varying streams. For each stream, a set function (`set<Name>`) is generated and made
     * available to the `gsplatModifyVS` shader chunk, where it runs once per splat, and a
     * matching get function (`get<Name>`) is made available to the `gsplatModifyPS` shader
     * chunk, where the per-splat value can be read for each rendered fragment.
     *
     * Supported types are {@link TYPE_FLOAT32}, {@link TYPE_INT32} and {@link TYPE_UINT32}, with
     * 1 to 4 components. Adding or removing streams rebuilds the gsplat shaders.
     *
     * Note: on some platforms each component is stored in per-splat video memory, so its size
     * scales with the number of rendered splats. Keep the data as compact as possible - prefer
     * fewer components, and consider bit-packing multiple small values into a single uint
     * component instead of using separate streams.
     *
     * @param {GSplatVaryingDescriptor[]} streams - The streams to add.
     * @example
     * // Add a per-splat flag, written once per splat in gsplatModifyVS using setFlag(value),
     * // and read per fragment in gsplatModifyPS using getFlag()
     * app.scene.gsplat.varyings.add([{
     *     name: 'flag',
     *     type: TYPE_UINT32,
     *     components: 1
     * }]);
     */
    add(streams: GSplatVaryingDescriptor[]): void;
    /**
     * Removes varying streams previously added by {@link GSplatVaryings#add}.
     *
     * @param {string[]} names - The names of the streams to remove.
     */
    remove(names: string[]): void;
    /**
     * Marks the streams as changed: recomputes the cache word count eagerly (so consumers never
     * see a stale value) and bumps the version. The shader chunks are regenerated and applied to
     * the material once per frame by the engine via {@link GSplatVaryings#apply}.
     *
     * @private
     */
    private _changed;
    /**
     * Generates the shader chunks implementing the varying streams: declarations and set
     * functions for the vertex stage (and its compute projector equivalent), declarations and
     * get functions for the fragment stage, and the projection cache read / write code used by
     * the hybrid renderer.
     *
     * @returns {object} The generated chunk sources.
     * @private
     */
    private _generateChunks;
    /**
     * Regenerates the shader chunks and applies them to the material, from where the renderers
     * pick them up (and rebuild shaders) via the existing chunk synchronization. Consumers track
     * {@link GSplatVaryings#version} to call this only when the streams changed.
     *
     * @param {ShaderMaterial} material - The gsplat material to apply the chunks to.
     * @ignore
     */
    apply(material: ShaderMaterial): void;
}
import type { ShaderMaterial } from '../materials/shader-material.js';
import type { GraphicsDevice } from '../../platform/graphics/graphics-device.js';