@polygonjs/polygonjs/src/modules/three/examples/jsm/loaders/obj2/shared/MeshReceiver.js

node-based WebGL 3D engine https://polygonjs.com

import {BufferAttribute} from 'three';
import {BufferGeometry} from 'three';
import {LineSegments} from 'three';
import {Mesh} from 'three';
import {Points} from 'three';
/**
 * Development repository: https://github.com/kaisalmen/WWOBJLoader
 */

/**
 *
 * @param {MaterialHandler} materialHandler
 * @constructor
 */
const MeshReceiver = function (materialHandler) {
	this.logging = {
		enabled: false,
		debug: false,
	};

	this.callbacks = {
		onProgress: null,
		onMeshAlter: null,
	};
	this.materialHandler = materialHandler;
};

MeshReceiver.prototype = {
	constructor: MeshReceiver,

	/**
	 * Enable or disable logging in general (except warn and error), plus enable or disable debug logging.
	 *
	 * @param {boolean} enabled True or false.
	 * @param {boolean} debug True or false.
	 */
	setLogging: function (enabled, debug) {
		this.logging.enabled = enabled === true;
		this.logging.debug = debug === true;
	},

	/**
	 *
	 * @param {Function} onProgress
	 * @param {Function} onMeshAlter
	 * @private
	 */
	_setCallbacks: function (onProgress, onMeshAlter) {
		if (onProgress !== null && onProgress !== undefined && onProgress instanceof Function) {
			this.callbacks.onProgress = onProgress;
		}

		if (onMeshAlter !== null && onMeshAlter !== undefined && onMeshAlter instanceof Function) {
			this.callbacks.onMeshAlter = onMeshAlter;
		}
	},

	/**
	 * Builds one or multiple meshes from the data described in the payload (buffers, params, material info).
	 *
	 * @param {Object} meshPayload Raw mesh description (buffers, params, materials) used to build one to many meshes.
	 * @returns {Mesh[]} mesh Array of {@link Mesh}
	 */
	buildMeshes: function (meshPayload) {
		const meshName = meshPayload.params.meshName;
		const buffers = meshPayload.buffers;

		const bufferGeometry = new BufferGeometry();
		if (buffers.vertices !== undefined && buffers.vertices !== null) {
			bufferGeometry.setAttribute('position', new BufferAttribute(new Float32Array(buffers.vertices), 3));
		}

		if (buffers.indices !== undefined && buffers.indices !== null) {
			bufferGeometry.setIndex(new BufferAttribute(new Uint32Array(buffers.indices), 1));
		}

		if (buffers.colors !== undefined && buffers.colors !== null) {
			bufferGeometry.setAttribute('color', new BufferAttribute(new Float32Array(buffers.colors), 3));
		}

		if (buffers.normals !== undefined && buffers.normals !== null) {
			bufferGeometry.setAttribute('normal', new BufferAttribute(new Float32Array(buffers.normals), 3));
		} else {
			bufferGeometry.computeVertexNormals();
		}

		if (buffers.uvs !== undefined && buffers.uvs !== null) {
			bufferGeometry.setAttribute('uv', new BufferAttribute(new Float32Array(buffers.uvs), 2));
		}

		if (buffers.skinIndex !== undefined && buffers.skinIndex !== null) {
			bufferGeometry.setAttribute('skinIndex', new BufferAttribute(new Uint16Array(buffers.skinIndex), 4));
		}

		if (buffers.skinWeight !== undefined && buffers.skinWeight !== null) {
			bufferGeometry.setAttribute('skinWeight', new BufferAttribute(new Float32Array(buffers.skinWeight), 4));
		}

		let material, materialName, key;
		const materialNames = meshPayload.materials.materialNames;
		const createMultiMaterial = meshPayload.materials.multiMaterial;
		const multiMaterials = [];

		for (key in materialNames) {
			materialName = materialNames[key];
			material = this.materialHandler.getMaterial(materialName);
			if (createMultiMaterial) multiMaterials.push(material);
		}

		if (createMultiMaterial) {
			material = multiMaterials;
			const materialGroups = meshPayload.materials.materialGroups;
			let materialGroup;
			for (key in materialGroups) {
				materialGroup = materialGroups[key];
				bufferGeometry.addGroup(materialGroup.start, materialGroup.count, materialGroup.index);
			}
		}

		const meshes = [];
		let mesh;
		let callbackOnMeshAlterResult;
		let useOrgMesh = true;
		const geometryType = meshPayload.geometryType === null ? 0 : meshPayload.geometryType;

		if (this.callbacks.onMeshAlter) {
			callbackOnMeshAlterResult = this.callbacks.onMeshAlter({
				detail: {
					meshName: meshName,
					bufferGeometry: bufferGeometry,
					material: material,
					geometryType: geometryType,
				},
			});
		}

		// here LoadedMeshUserOverride is required to be provided by the callback used to alter the results
		if (callbackOnMeshAlterResult) {
			if (callbackOnMeshAlterResult.isDisregardMesh()) {
				useOrgMesh = false;
			} else if (callbackOnMeshAlterResult.providesAlteredMeshes()) {
				for (const i in callbackOnMeshAlterResult.meshes) {
					meshes.push(callbackOnMeshAlterResult.meshes[i]);
				}

				useOrgMesh = false;
			}
		}

		if (useOrgMesh) {
			if (meshPayload.computeBoundingSphere) bufferGeometry.computeBoundingSphere();
			if (geometryType === 0) {
				mesh = new Mesh(bufferGeometry, material);
			} else if (geometryType === 1) {
				mesh = new LineSegments(bufferGeometry, material);
			} else {
				mesh = new Points(bufferGeometry, material);
			}

			mesh.name = meshName;
			meshes.push(mesh);
		}

		let progressMessage = meshPayload.params.meshName;
		if (meshes.length > 0) {
			const meshNames = [];
			for (const i in meshes) {
				mesh = meshes[i];
				meshNames[i] = mesh.name;
			}

			progressMessage +=
				': Adding mesh(es) (' + meshNames.length + ': ' + meshNames + ') from input mesh: ' + meshName;
			progressMessage += ' (' + (meshPayload.progress.numericalValue * 100).toFixed(2) + '%)';
		} else {
			progressMessage += ': Not adding mesh: ' + meshName;
			progressMessage += ' (' + (meshPayload.progress.numericalValue * 100).toFixed(2) + '%)';
		}

		if (this.callbacks.onProgress) {
			this.callbacks.onProgress('progress', progressMessage, meshPayload.progress.numericalValue);
		}

		return meshes;
	},
};

/**
 * Object to return by callback onMeshAlter. Used to disregard a certain mesh or to return one to many meshes.
 * @class
 *
 * @param {boolean} disregardMesh=false Tell implementation to completely disregard this mesh
 * @param {boolean} disregardMesh=false Tell implementation that mesh(es) have been altered or added
 */
const LoadedMeshUserOverride = function (disregardMesh, alteredMesh) {
	this.disregardMesh = disregardMesh === true;
	this.alteredMesh = alteredMesh === true;
	this.meshes = [];
};

LoadedMeshUserOverride.prototype = {
	constructor: LoadedMeshUserOverride,

	/**
	 * Add a mesh created within callback.
	 *
	 * @param {Mesh} mesh
	 */
	addMesh: function (mesh) {
		this.meshes.push(mesh);
		this.alteredMesh = true;
	},

	/**
	 * Answers if mesh shall be disregarded completely.
	 *
	 * @returns {boolean}
	 */
	isDisregardMesh: function () {
		return this.disregardMesh;
	},

	/**
	 * Answers if new mesh(es) were created.
	 *
	 * @returns {boolean}
	 */
	providesAlteredMeshes: function () {
		return this.alteredMesh;
	},
};

export {MeshReceiver, LoadedMeshUserOverride};