backend/libs/three/extras/core/ShapePath.js

import { Color } from '../../math/Color.js';
import { Path } from './Path.js';
import { Shape } from './Shape.js';
import { ShapeUtils } from '../ShapeUtils.js';

class ShapePath {
	constructor() {
		this.type = 'ShapePath';

		this.color = new Color();

		this.subPaths = [];
		this.currentPath = null;
	}

	moveTo(x, y) {
		this.currentPath = new Path();
		this.subPaths.push(this.currentPath);
		this.currentPath.moveTo(x, y);

		return this;
	}

	lineTo(x, y) {
		this.currentPath.lineTo(x, y);

		return this;
	}

	quadraticCurveTo(aCPx, aCPy, aX, aY) {
		this.currentPath.quadraticCurveTo(aCPx, aCPy, aX, aY);

		return this;
	}

	bezierCurveTo(aCP1x, aCP1y, aCP2x, aCP2y, aX, aY) {
		this.currentPath.bezierCurveTo(aCP1x, aCP1y, aCP2x, aCP2y, aX, aY);

		return this;
	}

	splineThru(pts) {
		this.currentPath.splineThru(pts);

		return this;
	}

	toShapes(isCCW, noHoles) {
		function toShapesNoHoles(inSubpaths) {
			const shapes = [];

			for (let i = 0, l = inSubpaths.length; i < l; i++) {
				const tmpPath = inSubpaths[i];

				const tmpShape = new Shape();
				tmpShape.curves = tmpPath.curves;

				shapes.push(tmpShape);
			}

			return shapes;
		}

		function isPointInsidePolygon(inPt, inPolygon) {
			const polyLen = inPolygon.length;

			// inPt on polygon contour => immediate success    or
			// toggling of inside/outside at every single! intersection point of an edge
			//  with the horizontal line through inPt, left of inPt
			//  not counting lowerY endpoints of edges and whole edges on that line
			let inside = false;
			for (let p = polyLen - 1, q = 0; q < polyLen; p = q++) {
				let edgeLowPt = inPolygon[p];
				let edgeHighPt = inPolygon[q];

				let edgeDx = edgeHighPt.x - edgeLowPt.x;
				let edgeDy = edgeHighPt.y - edgeLowPt.y;

				if (Math.abs(edgeDy) > Number.EPSILON) {
					// not parallel
					if (edgeDy < 0) {
						edgeLowPt = inPolygon[q];
						edgeDx = -edgeDx;
						edgeHighPt = inPolygon[p];
						edgeDy = -edgeDy;
					}

					if (inPt.y < edgeLowPt.y || inPt.y > edgeHighPt.y) continue;

					if (inPt.y === edgeLowPt.y) {
						if (inPt.x === edgeLowPt.x) return true; // inPt is on contour ?
						// continue;				// no intersection or edgeLowPt => doesn't count !!!
					} else {
						const perpEdge = edgeDy * (inPt.x - edgeLowPt.x) - edgeDx * (inPt.y - edgeLowPt.y);
						if (perpEdge === 0) return true; // inPt is on contour ?
						if (perpEdge < 0) continue;
						inside = !inside; // true intersection left of inPt
					}
				} else {
					// parallel or collinear
					if (inPt.y !== edgeLowPt.y) continue; // parallel
					// edge lies on the same horizontal line as inPt
					if ((edgeHighPt.x <= inPt.x && inPt.x <= edgeLowPt.x) || (edgeLowPt.x <= inPt.x && inPt.x <= edgeHighPt.x)) return true; // inPt: Point on contour !
					// continue;
				}
			}

			return inside;
		}

		const isClockWise = ShapeUtils.isClockWise;

		const subPaths = this.subPaths;
		if (subPaths.length === 0) return [];

		if (noHoles === true) return toShapesNoHoles(subPaths);

		let solid, tmpPath, tmpShape;
		const shapes = [];

		if (subPaths.length === 1) {
			tmpPath = subPaths[0];
			tmpShape = new Shape();
			tmpShape.curves = tmpPath.curves;
			shapes.push(tmpShape);
			return shapes;
		}

		let holesFirst = !isClockWise(subPaths[0].getPoints());
		holesFirst = isCCW ? !holesFirst : holesFirst;

		// console.log("Holes first", holesFirst);

		const betterShapeHoles = [];
		const newShapes = [];
		let newShapeHoles = [];
		let mainIdx = 0;
		let tmpPoints;

		newShapes[mainIdx] = undefined;
		newShapeHoles[mainIdx] = [];

		for (let i = 0, l = subPaths.length; i < l; i++) {
			tmpPath = subPaths[i];
			tmpPoints = tmpPath.getPoints();
			solid = isClockWise(tmpPoints);
			solid = isCCW ? !solid : solid;

			if (solid) {
				if (!holesFirst && newShapes[mainIdx]) mainIdx++;

				newShapes[mainIdx] = { s: new Shape(), p: tmpPoints };
				newShapes[mainIdx].s.curves = tmpPath.curves;

				if (holesFirst) mainIdx++;
				newShapeHoles[mainIdx] = [];

				//console.log('cw', i);
			} else {
				newShapeHoles[mainIdx].push({ h: tmpPath, p: tmpPoints[0] });

				//console.log('ccw', i);
			}
		}

		// only Holes? -> probably all Shapes with wrong orientation
		if (!newShapes[0]) return toShapesNoHoles(subPaths);

		if (newShapes.length > 1) {
			let ambiguous = false;
			const toChange = [];

			for (let sIdx = 0, sLen = newShapes.length; sIdx < sLen; sIdx++) {
				betterShapeHoles[sIdx] = [];
			}

			for (let sIdx = 0, sLen = newShapes.length; sIdx < sLen; sIdx++) {
				const sho = newShapeHoles[sIdx];

				for (let hIdx = 0; hIdx < sho.length; hIdx++) {
					const ho = sho[hIdx];
					let hole_unassigned = true;

					for (let s2Idx = 0; s2Idx < newShapes.length; s2Idx++) {
						if (isPointInsidePolygon(ho.p, newShapes[s2Idx].p)) {
							if (sIdx !== s2Idx) toChange.push({ froms: sIdx, tos: s2Idx, hole: hIdx });
							if (hole_unassigned) {
								hole_unassigned = false;
								betterShapeHoles[s2Idx].push(ho);
							} else {
								ambiguous = true;
							}
						}
					}

					if (hole_unassigned) {
						betterShapeHoles[sIdx].push(ho);
					}
				}
			}
			// console.log("ambiguous: ", ambiguous);

			if (toChange.length > 0) {
				// console.log("to change: ", toChange);
				if (!ambiguous) newShapeHoles = betterShapeHoles;
			}
		}

		let tmpHoles;

		for (let i = 0, il = newShapes.length; i < il; i++) {
			tmpShape = newShapes[i].s;
			shapes.push(tmpShape);
			tmpHoles = newShapeHoles[i];

			for (let j = 0, jl = tmpHoles.length; j < jl; j++) {
				tmpShape.holes.push(tmpHoles[j].h);
			}
		}

		//console.log("shape", shapes);

		return shapes;
	}
}

export { ShapePath };