gpu-curtains/dist/esm/core/shaders/chunks/fragment/body/get-clearcoat.mjs

gpu-curtains is a 3D WebGPU rendering engine. It can be used as a standalone 3D engine, but also includes extra classes focused on mapping 3d objects to DOM elements; It allows users to synchronize values such as position, sizing, or scale between them.

import { getTextureSample } from "./get-texture-sample.mjs";
//#region src/core/shaders/chunks/fragment/body/get-clearcoat.ts
/**
* Set the `clearcoat` (`f32`) and `clearcoatRoughness` (`f32`) values from the material clearcoat variables and eventual clearcoat textures.
*
* @param parameters - Parameters used to set the `clearcoat` (`f32`) and `clearcoatRoughness` (`f32`) values.
* @param parameters.extensionsUsed - {@link PBRFragmentShaderInputParams.extensionsUsed | extensionsUsed} to check if clearcoat is enabled.
* @param parameters.clearcoatTexture - {@link ShaderTextureDescriptor | Clearcoat texture descriptor} (mixing both clearcoat factor in the `R` channel and roughness in the `G` channel) to use if any.
* @param parameters.clearcoatFactorTexture - {@link ShaderTextureDescriptor | Clearcoat factor texture descriptor} (using the `R` channel) to use if any.
* @param parameters.clearcoatRoughnessTexture - {@link ShaderTextureDescriptor | Clearcoat roughness texture descriptor} (using the `G` channel) to use if any.
* @returns - String with the `clearcoat` (`f32`) and `clearcoatRoughness` (`f32`) values set.
*/
const getClearcoat = ({ extensionsUsed = [], clearcoatTexture = null, clearcoatFactorTexture = null, clearcoatRoughnessTexture = null }) => {
	let clearcoat = `
  var clearcoatF0: vec3f = vec3(pow((ior - 1.0) / (ior + 1.0), 2.0));
  var clearcoatF90: f32 = 1.0;
  
  var clearcoatSpecularDirect: vec3f = vec3( 0.0 );
  var clearcoatSpecularIndirect: vec3f = vec3( 0.0 );`;
	if (!extensionsUsed.includes("KHR_materials_clearcoat")) return clearcoat;
	if (clearcoatTexture) {
		clearcoat += getTextureSample(clearcoatTexture, "clearcoat");
		clearcoat += `
  clearcoat = clearcoat * clearcoatSample.r;
  clearcoatRoughness = clearcoatRoughness * clearcoatSample.g;
    `;
	} else {
		if (clearcoatFactorTexture) {
			clearcoat += getTextureSample(clearcoatFactorTexture, "clearcoatFactor");
			clearcoat += `
  clearcoat = clearcoat * clearcoatFactorSample.r;
    `;
		}
		if (clearcoatRoughnessTexture) {
			clearcoat += getTextureSample(clearcoatRoughnessTexture, "clearcoatRoughness");
			clearcoat += `
  clearcoatRoughness = clearcoatRoughness * clearcoatRoughnessSample.g;
    `;
		}
	}
	clearcoat += `
  clearcoatRoughness = max( clearcoatRoughness, 0.0525 );
  clearcoatRoughness += geometryRoughness;
  clearcoatRoughness = min( clearcoatRoughness, 1.0 );
  `;
	return clearcoat;
};
/**
* Set the `clearcoatNormal` (`vec3f`) value from the material eventual clearcoat normal or normal textures.
*
* @param parameters - Parameters used to set the anisotropy values.
* @param parameters.extensionsUsed - {@link PBRFragmentShaderInputParams.extensionsUsed | extensionsUsed} to check if clearcoat is enabled.
* @param parameters.normalTexture - {@link ShaderTextureDescriptor | Normal texture descriptor} to use if any.
* @param parameters.clearcoatNormalTexture - {@link ShaderTextureDescriptor | Clearcoat normal texture descriptor} to use if any.
* @returns - String with the `clearcoatNormal` (`vec3f`) value set.
*/
const getClearcoatNormal = ({ extensionsUsed = [], normalTexture = null, clearcoatNormalTexture = null }) => {
	let clearcoatNormal = `
  var clearcoatNormal: vec3f = geometryNormal;`;
	if (!extensionsUsed.includes("KHR_materials_clearcoat")) return clearcoatNormal;
	if (clearcoatNormalTexture) {
		if (normalTexture) clearcoatNormal += `
    let clearcoatNormalSample = textureSample(${clearcoatNormalTexture.texture.options.name}, ${clearcoatNormalTexture.sampler?.name ?? "defaultSampler"}, normalUV);`;
		else clearcoatNormal += getTextureSample(clearcoatNormalTexture, "clearcoatNormal");
		clearcoatNormal += `
  var clearcoatMapN: vec3f = clearcoatNormalSample.rgb * 2.0 - 1.0;
  clearcoatMapN = vec3(clearcoatMapN.x * clearcoatNormalScale.x, clearcoatMapN.y * clearcoatNormalScale.y, clearcoatMapN.z);
  clearcoatNormal = normalize(tbn * clearcoatMapN);
  `;
	}
	return clearcoatNormal;
};
//#endregion
export { getClearcoat, getClearcoatNormal };