CaiYuanYiTiHua/src/components/MapboxMaps/lib/splitpolygon.ts

import { generateUUID } from '../src/tool';

/**
 * 使用turf工具进行切割面
 * @param line 线段数据
 * @param outerPolygon 面数据
 * return  返回切割的面数据
 */
export function splitPolygonByLine(line, outerPolygon) {
  let truncatedSplitter = turf.truncate(turf.lineString(outerPolygon.geometry.coordinates[0]), {
    precision: 7,
  });

  //求交点
  let intersectCollection = turf.lineIntersect(line, truncatedSplitter);
  
  if (intersectCollection.features.length < 2) {
    return null;
  }

  //将点合并成MultiPoint
  let intersectCombined = turf.combine(intersectCollection).features[0];

  //分别获取切割线
  let outerPieceCollection = turf.lineSplit(line, intersectCombined);
  let splitterPieceCollection = turf.lineSplit(truncatedSplitter, intersectCombined);

  //将所有的线段放到一起
  let pieceCollection = turf.featureCollection(
    outerPieceCollection.features.concat(splitterPieceCollection.features),
  );

  //使用turf将闭合线组成多边形
  let polygonCollection = turf.polygonize(pieceCollection);

  //对多边形进行判断，切割外的多边形丢弃
  let innerPolygons = polygonCollection.features.filter((polygon) => {
    // 获取多边形质心 多边形不规则时有问题
    // let center = turf.centroid(polygon);

    // 获取多边形表面一点
    let newcenter = turf.pointOnFeature(polygon);

    // 判断点是否在被分割图斑内
    // 图斑中心点 
    let centerPoint = turf.point(newcenter.geometry.coordinates);
    // 图斑面
    let outPolygon = turf.polygon(outerPolygon.geometry.coordinates)
    // return turf.booleanPointInPolygon(centerPoint, outPolygon);

    // let innerPoint = getRandomPointInPolygon(outPolygon);

    // 获取多边形边界
    // let bbox = turf.bbox(outPolygon); // 获取多边形的边界框

    // return turf.booleanPointInPolygon(randomPoint.features[0], outPolygon);

    return turf.booleanWithin(centerPoint, outerPolygon);
  });
  //   let innerPolygons = polygonCollection.features;

  //处理镂空数据（多处镂空数据会导致计算错误，因为polygonize方法无法正常的返回数据）
  if (outerPolygon.geometry.coordinates?.length > 1) {
    //获取镂空的面数据
    let holeCollection = turf.featureCollection(
      outerPolygon.geometry.coordinates.slice(1).map((item) => turf.polygon([item])),
    );

    //剔除掉镂空的部分数据
    innerPolygons = innerPolygons.map((polygon) => {
      let diff = polygon;
      turf.featureEach(holeCollection, (hole) => {
        diff = turf.difference(diff, hole);
      });
      return diff;
    });
  }
  innerPolygons.forEach((item, index) => {
    innerPolygons[index].properties.id = generateUUID();
  });
  return innerPolygons;
}

function getRandomPointInPolygon(polygon) {
  const bbox = turf.bbox(polygon); // 获取多边形的边界框
  let point;

  do {
      point = turf.randomPoint(1, {bbox: bbox}).features[0]; // 从边界框中生成一个随机点
  } while (!turf.booleanPointInPolygon(point, polygon)); // 检查点是否在多边形内部

  return point;
}


export function splitPolygonByFill(fill, outerPolygon) {
  var polygon1 = turf.polygon(fill.geometry.coordinates);
  // var polygon1 = turf.polygon(
  //     [
  //         [
  //             [
  //                 118.08246593377775,
  //                 35.22214906870923
  //             ],
  //             [
  //                 118.0824468053414,
  //                 35.2221025269492
  //             ],
  //             [
  //                 118.08255783344151,
  //                 35.22206277960647
  //             ],
  //             [
  //                 118.08258527859043,
  //                 35.22213378126961
  //             ],
  //             [
  //                 118.08246593377775,
  //                 35.22214906870923
  //             ]
  //         ]
  //     ]
  // )

  var polygon2 = turf.polygon(outerPolygon.geometry.coordinates);
  // var polygon2 = turf.polygon(
  //     [
  //         [
  //             [
  //                 118.082358,
  //                 35.222126
  //             ],
  //             [
  //                 118.082517,
  //                 35.222061
  //             ],
  //             [
  //                 118.082535,
  //                 35.222098
  //             ],
  //             [
  //                 118.082372,
  //                 35.222163
  //             ],
  //             [
  //                 118.082358,
  //                 35.222126
  //             ]
  //         ]
  //     ]
  // )

  var difference = turf.difference(polygon1, polygon2);

  console.log('difference123', difference);
  return difference;
}