@polygonjs/polygonjs/src/engine/operations/sop/Polywire.ts

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

import {BaseSopOperation} from './_Base';
import {CoreGroup} from '../../../core/geometry/Group';
import {Vector3, Matrix4, LineSegments, BufferGeometry, Object3D} from 'three';
import {ObjectType} from '../../../core/geometry/Constant';
import {CircleCreateOptions, CoreGeometryUtilCircle} from '../../../core/geometry/util/Circle';
import {CoreGeometryUtilCurve} from '../../../core/geometry/util/Curve';
import {CoreGeometryOperationSkin} from '../../../core/geometry/operation/Skin';
import {BaseCorePoint, CorePoint} from '../../../core/geometry/entities/point/CorePoint';
import {isBooleanTrue} from '../../../core/Type';
import {DefaultOperationParams} from '../../../core/operations/_Base';
import {CoreGeometryBuilderMerge} from '../../../core/geometry/modules/three/builders/Merge';
import {addAttributesFromPoint} from '../../../core/geometry/util/addAttributesFromPoint';
import {pointsFromObject} from '../../../core/geometry/entities/point/CorePointUtils';
import {corePointClassFactory} from '../../../core/geometry/CoreObjectFactory';
import {copyObject3DProperties} from '../../../core/geometry/modules/three/ThreejsObjectUtils';
import {CoreObjectType} from '../../../core/geometry/ObjectContent';
import {SopType} from '../../poly/registers/nodes/types/Sop';

interface PolywireSopParams extends DefaultOperationParams {
	radius: number;
	segmentsRadial: number;
	closed: boolean;
	attributesToCopy: string;
}
const ORIGIN = new Vector3(0, 0, 0);
const UP = new Vector3(0, 1, 0);

const lookAtMat = new Matrix4();
const translateMat = new Matrix4();
const currentPos = new Vector3();
const prevPos = new Vector3();
const nextPos = new Vector3();
const delta = new Vector3();
const deltaNext = new Vector3();
const deltaPrev = new Vector3();
const _points: CorePoint<CoreObjectType>[] = [];

export class PolywireSopOperation extends BaseSopOperation {
	static override readonly DEFAULT_PARAMS: PolywireSopParams = {
		radius: 1,
		segmentsRadial: 8,
		closed: true,
		attributesToCopy: '*',
	};
	static override type(): Readonly<SopType.POLYWIRE> {
		return SopType.POLYWIRE;
	}

	override cook(inputCoreGroups: CoreGroup[], params: PolywireSopParams) {
		const coreGroup = inputCoreGroups[0];
		const inputObjects = coreGroup.threejsObjects();

		const newObjects: Object3D[] = [];
		for (const inputObject of inputObjects) {
			const geometries: BufferGeometry[] = [];
			if ((inputObject as LineSegments).isLineSegments) {
				this._createTube(inputObject as LineSegments, params, geometries);
			}
			const mergedGeometry = CoreGeometryBuilderMerge.merge(geometries);
			if (mergedGeometry) {
				const newObject = this.createObject(mergedGeometry, ObjectType.MESH);
				copyObject3DProperties(inputObject, newObject);
				newObjects.push(newObject);
			}
		}

		// const mergedGeometry = CoreGeometryBuilderMerge.merge(geometries);
		// for (const geometry of geometries) {
		// 	geometry.dispose();
		// }
		// if (mergedGeometry) {
		// 	const object = this.createObject(mergedGeometry, ObjectType.MESH);
		return this.createCoreGroupFromObjects(newObjects);
		// } else {
		// 	return this.createCoreGroupFromObjects([]);
		// }
	}

	private _createTube(lineSegment: LineSegments, params: PolywireSopParams, geometries: BufferGeometry[]) {
		const geometry = lineSegment.geometry as BufferGeometry;
		const corePointClass = corePointClassFactory(lineSegment);
		const attributeNames = corePointClass.attributeNamesMatchingMask(lineSegment, params.attributesToCopy);
		pointsFromObject(lineSegment, _points);
		const indices = geometry.getIndex()?.array;
		if (!indices) {
			return;
		}

		const accumulatedCurvePointIndices = CoreGeometryUtilCurve.accumulatedCurvePointIndices(indices);

		for (let curvePointIndices of accumulatedCurvePointIndices) {
			const currentPoints = curvePointIndices.map((index) => _points[index]);
			this._createTubeFromPoints(currentPoints, attributeNames, params, geometries);
		}
	}

	private _createTubeFromPoints(
		points: BaseCorePoint[],
		attributeNames: string[],
		params: PolywireSopParams,
		geometries: BufferGeometry[]
	) {
		if (points.length <= 1) {
			return;
		}

		const options: CircleCreateOptions = {
			radius: params.radius,
			segments: params.segmentsRadial,
			arcAngle: 360,
			connectLastPoint: true,
		};
		const circleTemplate = CoreGeometryUtilCircle.create(options);
		const circles: BufferGeometry[] = [];
		// const scale = 1;
		let i = 0;
		for (let point of points) {
			point.position(currentPos);
			let prevPoint = points[i - 1];
			let nextPoint = points[i + 1];
			if (prevPoint && nextPoint) {
				// if we have both prev and next points, the dir is a blend between the dir to the prev and to the next
				nextPoint.position(nextPos);
				deltaNext.copy(nextPos).sub(currentPos);
				prevPoint.position(prevPos);
				deltaPrev.copy(prevPos).sub(currentPos).multiplyScalar(-1);
				delta.lerpVectors(deltaNext, deltaPrev, 0.5);
			} else {
				if (nextPoint) {
					nextPoint.position(nextPos);
					delta.copy(nextPos).sub(currentPos);
				} else {
					nextPoint = points[i - 1];
					nextPoint.position(nextPos);
					delta.copy(nextPos).sub(currentPos).multiplyScalar(-1);
				}
			}

			lookAtMat.identity();
			lookAtMat.lookAt(ORIGIN, delta.multiplyScalar(-1), UP);
			translateMat.identity();
			translateMat.makeTranslation(currentPos.x, currentPos.y, currentPos.z);

			const newCircle = circleTemplate.clone();
			newCircle.applyMatrix4(lookAtMat);
			newCircle.applyMatrix4(translateMat);

			// remove position before transfering the attribute
			const positionIndex = attributeNames.indexOf('position');
			if (positionIndex >= 0) {
				attributeNames.splice(positionIndex, 1);
			}
			addAttributesFromPoint(newCircle, point, attributeNames);

			circles.push(newCircle);
			i++;
		}

		for (let i = 0; i < circles.length; i++) {
			if (i > 0) {
				const circle = circles[i];
				const prevCircle = circles[i - 1];

				const geometry = this._skin(prevCircle, circle);
				geometries.push(geometry);
			}
		}
		if (isBooleanTrue(params.closed)) {
			const circle = circles[0];
			const prevCircle = circles[circles.length - 1];

			const geometry = this._skin(prevCircle, circle);
			geometries.push(geometry);
		}
	}

	_skin(geometry1: BufferGeometry, geometry0: BufferGeometry) {
		const geometry = new BufferGeometry();

		const operation = new CoreGeometryOperationSkin(geometry, geometry1, geometry0);
		operation.process();

		return geometry;
	}
}