import { bitangentView } from './Bitangent.js';
import { normalView, transformedNormalView } from './Normal.js';
import { tangentView } from './Tangent.js';
import { mat3 } from '../tsl/TSLBase.js';
import { mix } from '../math/MathNode.js';
import { anisotropy, anisotropyB, roughness } from '../core/PropertyNode.js';
import { positionViewDirection } from './Position.js';
/** @module AccessorsUtils **/
/**
* TSL object that represents the TBN matrix in view space.
*
* @type {Node<mat3>}
*/
export const TBNViewMatrix = /*@__PURE__*/ mat3( tangentView, bitangentView, normalView );
/**
* TSL object that represents the parallax direction.
*
* @type {Node<mat3>}
*/
export const parallaxDirection = /*@__PURE__*/ positionViewDirection.mul( TBNViewMatrix )/*.normalize()*/;
/**
* TSL function for computing parallax uv coordinates.
*
* @function
* @param {Node<vec2>} uv - A uv node.
* @param {Node<vec2>} scale - A scale node.
* @returns {Node<vec2>} Parallax uv coordinates.
*/
export const parallaxUV = ( uv, scale ) => uv.sub( parallaxDirection.mul( scale ) );
/**
* TSL function for computing bent normals.
*
* @function
* @returns {Node<vec3>} Bent normals.
*/
export const transformedBentNormalView = /*@__PURE__*/ ( () => {
// https://google.github.io/filament/Filament.md.html#lighting/imagebasedlights/anisotropy
let bentNormal = anisotropyB.cross( positionViewDirection );
bentNormal = bentNormal.cross( anisotropyB ).normalize();
bentNormal = mix( bentNormal, transformedNormalView, anisotropy.mul( roughness.oneMinus() ).oneMinus().pow2().pow2() ).normalize();
return bentNormal;
} )();