import type { SmokePointerInput, SmokeSimulationResult } from './SmokeNode.cjs';
/** RTT-specific result returned by {@link smokeRTT}. */
export type SmokeNodeRTTResult = SmokeSimulationResult;
/**
 * Smoke RTT Simulation (TSL) – a 2D velocity–pressure solver using RenderTargets.
 *
 * This is an RTT-based variant of the smoke simulation that uses RenderTarget + fragment shaders
 * instead of StorageTexture + compute shaders. This provides broader WebGPU compatibility
 * as it doesn't require Tier2 read-write storage texture support.
 *
 * The API is identical to `smoke()` - drop-in replacement for environments without Tier2 support.
 *
 * **Features**
 * - Semi-Lagrangian advection for velocity and density
 * - Vorticity confinement (curl) and divergence-free projection (pressure solve)
 * - Configurable dissipation, pressure iterations and curl strength
 * - Optional pointer-driven splats via a `vec2` uniform
 * - Drop-in for a render pipeline: `renderPipeline.outputNode = smokeRTT(pointer, 128, 512, ...)`
 *
 * **Example: Basic render pipeline setup**
 *
 * ```js
 * import * as THREE from 'three/webgpu';
 * import { smokeRTT } from 'three-blocks/smoke';
 *
 * const renderer = new THREE.WebGPURenderer();
 * await renderer.init();
 *
 * const renderPipeline = new THREE.RenderPipeline(renderer);
 * const pointer = new THREE.Vector2();
 *
 * // smokeRTT(pointer, simRes, dyeRes, iterations, densityDissipation, velocityDissipation,
 * //          pressureDissipation, curlStrength, pressureFactor, radius, useBoundaries, pointerScale)
 * const fluidNode = smokeRTT(pointer, 128, 512, 3, 0.97, 0.98, 0.8, 20, 0.2, 0.1, true, 45);
 *
 * renderPipeline.outputNode = fluidNode;
 *
 * renderer.setAnimationLoop(() => renderPipeline.render());
 * ```
 *
 * **Example: Interactive pointer-driven splats**
 *
 * ```js
 * import * as THREE from 'three/webgpu';
 * import { smokeRTT } from 'three-blocks/smoke';
 *
 * const pointer = new THREE.Vector2();
 *
 * // Pass pointer as first argument - motion automatically injects splats
 * const fluidNode = smokeRTT(pointer, 128, 512, 3, 0.97, 0.98, 0.8, 20, 0.2, 0.1, true, 45);
 *
 * // Update pointer on mouse move (NDC coordinates: -1 to +1)
 * document.addEventListener('mousemove', (e) => {
 *   pointer.x = (e.clientX / window.innerWidth) * 2 - 1;
 *   pointer.y = -(e.clientY / window.innerHeight) * 2 + 1;
 * });
 * ```
 *
 * @function smokeRTT
 * @short RTT-based 2D fluid smoke sim node (broader WebGPU compatibility than compute-based smoke).
 * @category TSL
 * @tsl
 * @tags WebGPU, RTT
 * @demo docs/demos/fluid.html
 *
 * @param {THREE.Vector2} [pointer] - NDC-like pointer in [-1, 1]; when present, motion injects splats.
 * @param {number} [simRes=128] - Square resolution for velocity/pressure buffers.
 * @param {number} [dyeRes=512] - Square resolution for density buffer.
 * @param {number} [iterations=3] - Pressure Jacobi iterations per solve.
 * @param {number} [densityDissipation=0.97] - Density dissipation factor in [0, 1].
 * @param {number} [velocityDissipation=0.98] - Velocity dissipation factor in [0, 1].
 * @param {number} [pressureDissipation=0.8] - Damp factor for pressure clear step.
 * @param {number} [curlStrength=20] - Vorticity confinement scale.
 * @param {number} [pressureFactor=0.2] - Pressure factor constant in Jacobi updates.
 * @param {number} [radius=0.1] - Gaussian splat radius in UV^2. Increase for larger splats.
 * @param {boolean} [useBoundaries=true] - Mirror-velocity boundary conditions at screen edges.
 * @param {number} [pointerScale=45] - Multiplier applied to pointer delta when generating splats.
 * @param {number} [neighborStride=1] - Multiplier for curl/divergence/pressure neighbor texel offsets.
 * @param {number} [speedFactor=1] - Scales sub-stepping relative to frame time (lower = more substeps).
 * @returns {Node} Color node sampling the current dye texture of the fluid simulation.
 */
export declare const smokeRTT: (pointer?: SmokePointerInput | undefined, simRes?: number, dyeRes?: number, iterations?: number, densityDissipation?: number, velocityDissipation?: number, pressureDissipation?: number, curlStrength?: number, pressureFactor?: number, radius?: number, useBoundaries?: boolean, pointerScale?: number, neighborStride?: number, speedFactor?: number) => SmokeNodeRTTResult;